Media reports that a company behaves in a socially nonresponsible manner frequently result in consumer participation in a boycott. As time goes by, however, the number of consumers participating in the boycott starts dwindling. Yet, little is known on why individual participation in a boycott declines and what type of consumer is more likely to stop boycotting earlier rather than later. Integrating research on drivers of individual boycott participation with multi-stage models and the hot/cool cognition system, suggests a “heat-up” phase in which boycott participation is fueled by expressive drivers, and a “cool-down” phase in which instrumental drivers become more influential. Using a diverse set of real contexts, four empirical studies provide evidence supporting a set of hypotheses on promotors and inhibitors of boycott participation over time. Study 1 provides initial evidence for the influence of expressive and instrumental drivers in a food services context. Extending the context to video streaming services, e-tailing, and peer-to-peer ridesharing, Study 2, Study 3, and Study 4 show that the reasons consumers stop/continue boycotting vary systematically across four distinct groups. Taken together, the findings help activists sustain boycott momentum and assist firms in dealing more effectively with boycotts.The online version contains supplementary material available at 10.1007/s10551-021-04997-9. In 2013, a TV documentary on the substandard work conditions of employees who were subcontracted by a leading e-tailer evoked strong reactions with consumers in Germany, many of whom decided to boycott the company  may also be more likely to carry on boycotting during later stages (t1). Consistent with reports that initial egregiousness (t0) is a key driver of boycott participation in the initial phase (t0), possible changes in boycott participation should depend on perceived egregiousness  may influence boycott participation at that point in time (t1), the decision should further depend on the consumer’s initial decision to (not) join the boycott (t0). By partially replicating studies on perceived egregiousness as a key driver of boycott participation  and his or her current level of perceived egregiousness (t1).The previously discussed models of boycott participation have been limited to examining consumer motivations to boycott at one point in time. Suggesting that a temporal extension is needed, macro level studies indicate that boycotts gradually lose participants and momentum over time  on later boycott participation (t1) is.Perceived egregiousness will moderate the relationship between the initial boycott participation and participation at a later point in time. The higher the perceived egregiousness at At the macro level, boycotts can be categorized as instrumental or expressive , instrumental factors should become more influential over time, thereby leading to cognitive dissonance in the evaluation of the boycott and ultimatively to changes in the participation  and also (ii) at later stages (t1).As an expressive promoter, self-enhancement will influence boycott participation positively (i) at the initial stage  and also (ii) at later stages (t1).As an expressive inhibitor, brand image will influence boycott participation negatively (i) at the initial stage .As an instrumental promoter, perceived control will influence boycott participation positively at later stages .As an instrumental inhibitor, subjective costs will influence boycott participation negatively at later stages  that have been validated in previous studies of boycotting. However, because our focus is on examining boycott dynamics across a number of divergent business contexts, relevant characteristics of these contexts need to be accounted for. For example, certain inhibitors may be particularly relevant in service contexts, especially inhibitors related to service intangibility and provider attributes .As an instrumental inhibitor, perceived service quality will have a negative effect on boycott participation at later stages .As an instrumental inhibitor, the customer-friendly behavior of frontline employees will have a negative effect on boycott participation at later stages ; 233 of them returned for the second set of measurements. Data sets from an additional 31 participants were subsequently dropped due to failing an attention check. We randomly recruited participants without screening for prior purchase of the company’s products. A non-response analysis showed no systematic differences between participants who completed both questionnaires and those who dropped out after the first round.3We collected data at two points in time, with a time lag of three weeks.In the first round, we started the survey by presenting the vignette, followed by the request to list three more questionable actions attributed to the brand. Since most subjects repeated the content from the vignettes, we could verify that the participants had no doubts about the realism and credibility of the study. Furthermore, listing further immoral aspects helped us not only rule out individual differences among the participants in terms of the evaluation of the company's immoral behaviors but also reinforce the intended effect of the vignettes. In the second round, to avoid priming bias we merely stated that this study would be a follow-up to the one they had completed previously. In both rounds, we assessed boycott behavior, as well as inhibitors and promoters. We adapted measures of boycott participation developed by Nerb and Spada , as wellt0), perceived egregiousness (t1), and the interaction term of both variables as the independent variables and boycott participation as the dependent variable (Table t0) × perceived egregiousness (t1) interaction effect on boycott participation (t1)  interacts with perceived egregiousness at t1 to affect boycott participation at t1. Effects vary systematically for expressive drivers (perceived egregiousness and brand image) and also for instrumental drivers (subjective costs and perceived control); furthermore, effects vary between the heat-up and the cool-down phases. Study 1 also highlights the role of frontline employees in dealing with boycotts. Especially in business contexts where frontline employees contribute substantially to customers’ perception of the company, such as in fast food restaurants, perceived service quality overrides other influencers of boycott participation. This finding has strong practical implications, because increasing numbers of fast food chains implement self-order kiosks, thereby reducing direct contact between customers and employees. Our findings suggest that this approach can backfire in times of egregious acts because of a lack of opportunities for frontline employees to restore damaged customer relationships.Our results show that the initial boycott participation . Third, Study 2 further disentangles the roles played by boycott drivers with distinct consumer groups. We explore temporal changes in a within-subjects design at two points in time with a time lag of two weeks.Study 2 examined how consumers respond to the alleged immoral behavior of a leading online movie streaming provider. Participants first read a vignette including news reports that the company offered morally questionable shows and movies. For example, a novel reality show format encouraged a group of actors to talk an unknowing participant into committing murder. In a second case, a woman blamed the firm for her daughter’s attempt to commit suicide. In a third case, a corporate comedian proudly announced that his show was the main catalyst for over 4,500 relationships being terminated, including many divorces. In light of these news, the vignette alleged that the company’s customers started to boycott the firm and to switch to other providers. Again, we explained to participants that the presented media excerpts presented real reports taken from actual news websites. Following the vignette, we again prompted participants to write down additional questionable behaviors of the firm. Again, subjects mostly repeated the content from the vignettes, indicating that they had no doubts about the realism and credibility of the study. The vignettes are displayed in Appendix A3.age = 34.78, SDage = 10.31; 57% male), with 303 participants returning to continue at the second point in time. A non-response analysis indicated no significant differences between participants who completed the study at both times and those who dropped out after the first round.4We collected data at two points in time with a time lag of two weeks. Recruited from MTurk, 533 U.S. residents took part in an online survey (M2(1) = 3.51, p = 0.043).The overall design of the study was almost identical to that of Study 1, with all scales consisting of seven-point Likert-type ratings. Different from Study 1, we added a binary measure of boycott participation . To enhance the validity of the boycott scale, we included a behavioral measure by offering respondents an opportunity to participate in a lottery. Upon completing the survey, they could choose between four coupons, one of these valid with the video streaming company and three others valid with competitors. Choosing the coupon of the video streaming company was thought to indicate non-boycotting, while the other options were thought to indicate boycotting. Accordingly, the coupons provide a dichotomous index of boycotting vs. non-boycotting. The chi-square test with the dichotomous boycott measure and the dichotomous coupon choice indicated a significant relation between both variables (χt0), perceived egregiousness (t1), and the interaction term of both variables as the independent variables, and a binary boycott participation measure as the dependent variable. All variables were mean centered  and boycott participation (t0) had a significant and positive effect  on boycotting (t1), thereby supporting H1. In other words, increasing levels of perceived egregiousness in t1 enhanced the initial boycott behavior's positive influence on boycott participation in t1. Figure We ran binary logistic regressions with boycott participation , and had a marginally significant influence in t1 . Similarly, brand image, the expressive inhibitor, had significant negative effects in both t0  and t1 . In contrast, perceived control, the instrumental promoter, had a marginally significant and positive effect on boycott participation only at t1 . Among instrumental inhibitors, the effect of subjective costs on boycott participation was not significant at the two points in time, but perceived service quality had a significant negative influence in t1 only  as predicted in H3c.Self-enhancement, the expressive promoter, influenced boycott participation significantly and positively in Mt0 = 2.67, Mt1 = 3.93, t = 12.48, p ≤ 0.001) were labeled the Deliberators (Δboycottt1 − boycottt0 > 0). Respondents who exhibited constant levels  of boycott participation  were labeled the Apathetic. To split the large group of remaining respondents exhibiting a decrease in boycott participation (Δboycottt1 − boycottt0 < 0), we additionally accounted for changes in the level of perceived egregiousness [(Δegregiousness < 0) or (Δegregiousness ≥ 0)]. Consumers who exhibited a decreasing boycott participation . As a check to the robustness of the results obtained with the psychometric measure, results with the behavioral measure corroborated that Apathetic consumers stay with the boycotted e-tailer more than do the other types.As with Study 2, we categorized respondents according to the four boycotter types. To examine drivers of boycotting among the four types, we again ran four regression models (one for each type), with perceived egregiousness, promoters, and inhibitors as the independent variables, and boycott participation as the dependent variable (see Table t0) interacts with perceived egregiousness at t1 to affect boycott participation at t1. Furthermore, boycott participation over time varies between four types of consumers due to the divergent influence of boycotting drivers. Specifically, effects vary systematically for expressive drivers (perceived egregiousness and brand image), and also for instrumental drivers (subjective costs and perceived control). In addition, they vary between the heat-up and the cool-down phases. Furthermore, the results highlight the importance of socially responsible human resource management for employee work behaviors  had been suspended for trips originating at JFK Airport. This behavior caused approximately 500,000 consumers to delete the app, effectively boycotting the provider. A hashtag encouraging deletion of the app spread rapidly and widely through social media at the heart of the protest against the company. As before, we highlighted that the reports are taken from real news websites.Mage = 34.81, SDage = 9.21; 75% male). MTurk randomly assigned participants to the study regardless of whether or not they were actual customers of the ridesharing company. Of our sample, 35 respondents had never used the ridesharing service and were therefore excluded, leaving a final sample of 185 participants for subsequent analyses. To increase validity, the questions assessing consumer knowledge of the case (65% had heard of the boycott) appeared at the beginning of the questionnaire such that respondents were not able to draw conclusions about study objectives. As with Study 3, respondents indicated their level of perceived egregiousness and boycott participation for both the time of the survey  and, retrospectively, twelve months earlier (t0 = the time when the boycott was initiated).8In our study, 283 U.S. residents took part in an MTurk survey, with 220 participants completing all questions  and boycott participation  decrease significantly from the heat-up phase (t0) to the cool-down phase (t1). Further results indicate that perceived egregiousness (t1) interacts significantly  with boycott participation (t0) to affect boycotting at t1 (Table t1) and service quality on boycott participation , while the boycotting level of the Apathetic remained constant . The Forgetters displayed a decrease in boycott participation  in combination with a decrease in perceived egregiousness , whereas the Capitulated exhibited a decrease in boycott participation  paired with an increase in perceived egregiousness . Again, self-enhancement was a significant driver across groups , contexts , and study designs.Corporate Social Responsibility (CSR) Dahlsrud, Boycotts rarely maintain their level of intensity over time  to decrease switching costs and to ease the switch to competitors. On the other hand, to reduce the likelihood of extended boycotting, managers should consider raising boycott-related barriers, such as the (non-)monetary value of seeking alternatives. Third, we found that a high service quality can serve as an effective buffer against calls for boycotting. Companies should, therefore, maintain sufficiently high levels of service quality as a means to communicate more directly and competently with their customers. Similarly, activists should be aware of the high importance of service quality; to counter it, they could emphasize better service of a competitor as a motivation to switch. Fourth, in many cases frontline employees are the main touch points linking the company with its customers , while others maintain higher levels of perceived egregiousness over time and stop boycotting only because of individual cost–benefit considerations (the Capitulated). Yet, another consumer type starts boycotting only after a certain amount of time has passed (the Deliberators). Our findings can help boycott activists increase the success of their boycott in the long term. On the other hand, companies could use our findings to soften the negative boycott dynamics for avoiding damage in the short term. In response to the boycott call, the company might address the cause and remedy its unethical behavior that initially triggered the boycotts. Table This study has a few limitations, offering opportunities for further research. Conceptually, we make use of established theories to put forward the two-stage model of emotional heating and cognitive cooling. We caution readers, however, that a hard distinction between the two stages may be misleading and a more nuanced view may be useful for obtaining further insights. Methodologically, our measurement of boycott participation is based on self-reported scales and past behavior. While we validated these measures with a behavioral variable (lottery) in Study A few other avenues for future research need mentioning. From a conceptual perspective, our research is based on a cost–benefit model  should be examined. Prior research indicates that stakeholder attention after a company’s misconduct varies, often failing to result in retribution Barnett, . This isFourth, our study did not fully explore the emotional costs assosciated with boycotts. For example, future studies could examine the influence of related concepts, such as brand attachment Below is the link to the electronic supplementary material.


Objectives: To study the frequency of risk factors affecting the development of parastomal hernias in patients undergoing stoma formation.Study Design: A retrospective descriptive cross-sectional study.Duration of Study: This study was conducted at the Department of General Surgery between January 2017 to December 2020.Methodology: A total of 163 patients aged between 20 and 100 years and who required a stoma formation were included in the study. The patients with incomplete data and those lacking post-operative imaging were excluded. According to this selection criteria, 80 patients were excluded. The data was collected for all patients from the hospital database. This included patient’s demographic information, co-morbidities, pre-surgery patient characteristics, an indication of stoma formation, the location of stoma exit, type of surgery, associated comorbidities, subcutaneous fat thickness, and type of stoma formed. Data were analyzed using IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp.Results: The mean age was 68.46 ± 16.50 years, with males in the majority: 48 (57.8%). Most of the patients, 53 (63.8%), had malignant disease. Post-stoma formation, a total of 38 (45.9%) patients developed parastomal hernias, mostly involving the sigmoid colon . However, there was a statistically significant relationship between paroxysmal sympathetic hyperactivity (PSH) incidence with non-trans-rectus stomas  . Furthermore, malignancy was also not an independent predictor of PSH . All other risk factors included in this study were nonsignificant.Conclusion: Our study shows that the incidence of parastomal hernias is rising with a high rate demonstrated in our patients. There was no statistically significant association between patient-related preoperative and operative factors with increased risk of parastomal hernias in our population except for a non-trans-rectus stoma, which was identified as an independent risk factor for parastomal hernias. Based on our findings, we would recommend a trans-rectus stoma over all other stoma sites. However, a much larger study is needed to validate this finding further. Stoma formation is among the most commonly performed surgical procedures to redirect gut contents for various reasons . ParastoIt is reasonable to recognize the risk factors for parastomal hernias earlier and reduce the morbidity and mortality associated with this complication in colorectal surgeries. Hence, we conducted a retrospective study to investigate the frequency of occurrence of parastomal hernias in our center along with the possible risk factors in our community.This was a retrospective, descriptive cross-sectional study conducted from January 2017 to December 2020, which amounted to four years in the Department of General Surgery, Russells Hall Hospital, Dudley. All patients between 20 and 100 years with at least one year of completed follow-up that required a stoma formation as a part of the first operation were included in the study. A total of 163 surgeries for the construction of intestinal stomas were performed during the study period. Out of 163 patients, 29 patients didn’t have complete information, and 51 patients had no post-operative imaging, so these were excluded. The remainder of 83 patients with comprehensive database and post-operative imaging were included in the study  criteria. Pre-surgery features included co-morbidities, the indication of surgery, the etiology , and the confidential enquiry into perioperative deaths (CEPOD) level of intervention. Operative characteristics included the location of stoma exit, type of surgery, subcutaneous fat thickness, muscle thickness, and type of stoma formed. The primary outcome measure was to see if the site of stoma formation has any impact on parastomal hernias. CT scan was used as an adjunct to establish, if any, the relation between the fat thickness and the muscle thickness measured at the site of parastomal hernia. Data were analyzed using IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp. Mean and SD was calculated for quantitative variables, while qualitative variables were recorded in frequency and percentage. An independent sample t-test was applied for comparison between the groups, and the signiﬁcance level was determined to be < 0.05. Analysis was completed using IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp.We studied 83 patients, with a mean age of 68.46 ± 16.50 years. Males accounted for 57.8% (n=48) of these patients. The majority of the patients were white: 96.4% (n=80), 48.2% (n=40) suffered from diabetes mellitus. A total of 22 (26.5%) were ASA class I, while class II and III were 36 (43.3%) and 25 (30.2%), respectively.The majority of cases were performed electively: 57 (68.6%). The most frequently performed procedure was Hartmann’s procedure: 34 (41%), followed by abdominoperineal resection, which accounted for 32 (38.6%) cases. Colon was brought up to form a stoma in 61 (73.5%). In 49 (59.1%), end stomas were formed, while the rest were loop ostomies. A majority of the stomas were trans-rectus 48 (57.7%). A total of 38 (45.9%) patients developed parastomal hernias, most of which involved the sigmoid colon .Increasing age, gender, diabetes mellitus, etiology, CEPOD level, operative time, or type of stoma did not correlate with increased risk of parastomal hernia formation, as shown in Tables We found no statistically significant association regarding fat thickness and rectus muscle thickness calculated from the CT scan , respectively, which has been shown in Table The incidence of parastomal hernias has been on the rise in recent decades, not only due to increased surgeries resulting in the formation of stomas but also due to the frequent employment of imaging, such as computed tomography, for diagnosis of even small-sized hernias . Our stuOur study showed a positive relationship between the development of parastomal hernias and the location of the exit of the stoma, with a lower risk of occurrence if it was trans-rectus compared to trans-oblique or trans-oblique junctional stomas. Previous studies have shown that citing stoma outside the rectus muscle is associated with an increased risk of developing hernias . While oIt is highly likely that due to a limited number of patients and retrospective study design, we could not successfully identify any causal associations. However, it is essential to be aware of the findings of this study. We recommend a prospective study with a larger cohort of patients to ensure extra precautions can be taken to identify and address the patient-related risk factors and improve outcomes for patients who already have to bear the burden of reduced quality of life secondary to stoma formation.Our study shows that the incidence of parastomal hernias is on a rise, with a high rate shown in our patients as well. There was no statistically significant association found between patient-related preoperative as well as operative factors with increased risk of parastomal hernias in our population except for a non-trans-rectus stoma, which was identified as an independent risk factor for parastomal hernias. Based on our findings, we would recommend a trans-rectus stoma over all other stoma sites; however, a much larger study is needed to further validate this finding.


Despite the ample progress made toward faster and more accurate Monte Carlo (MC) simulation tools over the past decade, the limited usability and accessibility of these advanced modeling tools remain key barriers to widespread use among the broad user community.An open-source, high-performance, web-based MC simulator that builds upon modern cloud computing architectures is highly desirable to deliver state-of-the-art MC simulations and hardware acceleration to general users without the need for special hardware installation and optimization.We have developed a configuration-free, in-browser 3D MC simulation platform—Monte Carlo eXtreme (MCX) Cloud—built upon an array of robust and modern technologies, including a Docker Swarm-based cloud-computing backend and a web-based graphical user interface (GUI) that supports in-browser 3D visualization, asynchronous data communication, and automatic data validation via JavaScript Object Notation (JSON) schemas.The front-end of the MCX Cloud platform offers an intuitive simulation design, fast 3D data rendering, and convenient simulation sharing. The Docker Swarm container orchestration backend is highly scalable and can support high-demand GPU MC simulations using MCX over a dynamically expandable virtual cluster.http://mcx.space/cloud.MCX Cloud makes fast, scalable, and feature-rich MC simulations readily available to all biophotonics researchers without overhead. It is fully open-source and can be freely accessed at  First, the adoption of massively parallel computing and graphics processing units (GPUs) have greatly improved the computational efficiency of conventional MC simulations, shortening the simulation run-time by tens to hundreds fold on a modern GPU.,Compared to many published traditional research codes that were developed as single-release static software, an increasing number of new MC software packages have started tackling the challenges of usability and long-term maintainability. Many of these projects openly embrace state-of-the-art software engineering best practices and offer the software as a vibrantly growing platform via continuous enhancements, timely bug fixes, and active user support via flexible feedback channels. Ease-of-use has also become the focus of a number of recently published MC toolkits, where MATLAB-based dynamic library (MEX) interfaces and graphical user interfaces (GUIs) have been reported.,With the exciting progress in developing open-source MC simulators with increasing speed, functionality, accuracy, and user-friendliness, we would like to tackle here the next major challenge in high-performance, general-purpose MC photon simulation software, namely scalability and availability. A number of previous publications, including several from our group, have addressed the challenges in creating scalable simulations that can utilize more than one GPU or run simulations across CPUs/GPUs of multiple vendors. In particular, a number of previous papers reported OpenCL-based MC implementationsIn this work, we report a modern, scalable, high-performance, and fully open-source in-browser MC simulation platform—MCX Cloud—to bring state-of-the-art GPU hardware and our extensively optimized and feature-rich MCX simulator software to the rapidly growing biophotonics research community. Our MCX Cloud platform embraces an array of modern and standardized cloud-computing techniques. In the backend, it utilizes DockerA key advancement that enables us to develop such a compact, scalable and portable software/hardware platform is the adoption of JavaScript Object Notation  data exchange format, and is at the core of most today’s web-based applications. Compared to XML, JSON is extremely lightweight and fast to parse, yet it is capable of storing complex hierarchical data. Numerous free and lightweight JSON parsers are available today for nearly all existing programming languages, permitting plug-and-play implementation of JSON data support in most applications.Despite these aforementioned advantages, adoption of JSON in storing scientific data is largely limited to handling lightweight metadata. This is because JSON does not have explicit rules on how to serialize common scientific data structures such as N-dimensional (N-D) arrays, complex and sparse arrays, tables, graphs, trees, etc. Additionally, JSON does not directly support storage of strong-typed binary data. To bridge this gap, our group published an open-standard—the JData SpecificationIn addition to using JSON to encode input data, we have also completed the migration of MCX volumetric output data as of 2020, converting from the NIfTI data formatA key benefit of adopting JSON based data formats is to enable machine-automatable data validation. This can be readily achieved using the JSON Schema framework. JSON Schema is a systematic approach to defining data types, formats, and properties for each data entry in a JSON data structure, and is currently a proposed Internet standard by the Internet Engineering Task Force (IETF).2.4The front-end, i.e., the web GUI, of MCX Cloud consists of two major components—an in-browser JSON data editor to create JSON-formatted input data for MCX simulations and a 3D data rendering module based on WebGL (see below section). The web-based MCX JSON input editor was derived by combining an open-source general-purpose JSON editor developed by Jeremy Dorn et al. with our JSON-schema of MCX input JSON data format. The JSON editor module is a lightweight (73 kB in size) JavaScript library that enables the creation and editing of arbitrary JSON-formatted data using a user-defined schema. It also simultaneously supports a number of popular web GUI frameworks and icon libraries to improve customizability.A minimalistic design style is used to provide users with a clean and streamlined environment to create, preview, execute, render, and easily share MCX simulations. All front-end functionalities are achieved using a combination of HTML5 and JavaScript programming. Notably, the use of the JQuery library makes the front-end compact  and easy-to-maintain.2.5In the front-end of MCX Cloud, we have developed fully featured 3D shape and volumetric data rendering and download functionalities. In comparison, the web GUI of MCOnline only provides rendering and data downloading for a particular Our MCX JSON input file accepts two methods for defining a heterogeneous simulation domain: (1) a constructive solid geometry (CSG) approach using a list of shape primitive constructs such as spheres, boxes, cylinders, 2.6The client  and the server  communicate via asynchronous data communication, known as AJAX (asynchronous JavaScript And XML). Despite the name, JSON, instead of XML, has been predominantly used in today’s web applications data exchange. User inputs are encoded as lightweight JSONP (JSON with Padding) data packets and sent to the server; the server sends back the response, also encoded as JSON packets, and informs the JavaScript on the web GUI to update the web page content dynamically without needing to reload the entire web page.To facilitate the processing of user submissions and management of Docker Swarm jobs, we developed an ultra-compact common gateway interface (CGI) script, named “mcxserver,” written in the Perl programming language to handle user-submitted job requests. These submitted simulation data are stored in a database using SqliteTo optimize server disk usage, we define a job expiration time window (currently set to 1 h) and configure another recurrent process (known as a cron-job) to automatically clean the expired job folders to save space. If a simulation is frequently executed by users, such as the default simulation or built-in examples, we keep the simulation output folder in a cache folder to avoid repeated computation.2.7Guided by the FAIR principle3Following the methodologies discussed above, we have created a preview version of the MCX Cloud simulation platform. In this initial configuration of the MCX Cloud backend, we have currently included To demonstrate the GUI design in MCX Cloud’s front-end, in To show the 3D domain rendering functions in the web GUI, in Our 3D in-browser rendering tool also automatically renders MCX-computed fluence maps, also encoded in the JSON/JNIfTI format, returned by the server after the computation is completed. In To demonstrate that one can use MCX Cloud to distribute a large simulation across multiple GPU devices installed in the Docker Swarm, we launch the digimouse benchmark simultaneously to 10 GPUs installed on the backend, each running 3.1Over the past decade, MC-based photon transport simulation has gained ample progress in terms of speed and accuracy in modeling increasingly complex anatomical structures. A list of free and open-source MC simulators with various levels of functionalities have been developed, published, and actively maintained by a number of research groups. While some of these open-source toolkits have successfully attracted a sizable user community, most of these tools were disseminated using a conventional download-and-install approach. In addition, many high-performance MC simulators require purchasing and installing high-end graphics cards on users’ own computers to maximize efficiency. For less-experienced users, properly configuring and using these specialized simulation tools can be key barriers.This work specifically addresses challenges regarding the usability and availability of MC simulators as mentioned above. Particularly, we described an in-browser GPU-accelerated MC simulator and cloud-based service that can be launched anywhere a browser is available, including mobile devices such as a smartphone or a tablet. This system combines our decade-long, continual development in MCX light transport simulation software with state-of-the-art cloud-computing platforms, and offers a robust, scalable and forward-looking framework for a standardized, high-demand, high-throughput and community-focused MC modeling platform. Compared to the previously published online MC simulator, this new platform embraces the latest technologies in microservices, cloud-computing (containerization and orchestration), and web-based GUI design , and demonstrates high flexibility and scalability that were not previously available.We can not emphasize enough how adopting a standardized and web-friendly input/output data format in JSON/JData greatly simplified or even directly enabled the implementation of this lightweight yet highly versatile web-based platform. To be more specific, utilizing JSON to encode MCX’s input/output data allowed us to seamlessly integrate them with JavaScript and a web environment. Also, defining MCX’s input data using JSON schema allows the JSON Editor library to automatically create the JSON editing interface in our front-end. This in-browser JSON editor is not only intuitive to use, but also generates JSON data that automatically satisfies the specified schema. Similarly, adopting JSON and JData data annotations also allow MCX to store complex output data records, including volumetric fluence rate, partial-pathlengths, and various lightweight metadata in a unified, easy-to-read JSON format that can be readily transmitted, parsed and rendered inside a browser.Although we use MCX at the backend to perform the underlying MC computation, our cloud computing system can be readily adapted to use any other MC simulators, as long as the alternative simulator also supports JSON/JData as the input/output data format and provides the corresponding JSON schema of the desired input JSON data structure (can be entirely different from those of MCX). For the same reason, our current web GUI can be directly used in combination with MCX-CLFrom the benchmark results shown in Moving forward, we aim to complete the migration of our MMC simulatorThe next step of our project also includes further solidification and dissemination of the JData specificationhttp://mcx.space/cloud.In summary, we report a highly scalable, easy-to-use, and cloud-computing-based in-browser MC simulation platform—MCX Cloud. This platform was built upon an array of modern open-source technologies, including the use of Docker containers and container orchestration to run GPU-based MC simulations across a robust, elastic, scalable, and distributed virtual GPU cluster. It also leverages the latest web-based technologies, such as JSON, JSON schema, AJAX, and WebGL, to create an intuitive, easily expandable, and responsive web GUI. At the core of this cloud computing platform is our significantly improved MCX photon transport simulator, packaging numerous enhancements in GPU optimization and algorithmic features that we have developed and integrated over the past decade. We want to particularly highlight that this platform is fully open-source—we not only provide the source codes for the MCX simulator, but also those for the web GUI and server-side scripts—so that anyone can build a private cloud for internal use or modify these scripts to accommodate other similar solvers. In the meantime, we have built an initial GPU cloud containing


Blood Cancer Journal 10.1038/s41408-021-00468-6, published online 19 April 2021Correction to: After the publication of the original article, the author list was updated as given here:1, Gudmar Thorleifsson2, Aitzkoa Lopez de Lapuente Portilla1, Abhishek Niroula1,3, Molly Went4, Malte Thodberg1, Maroulio Pertesi1, Ram Ajore1, Caterina Cafaro1, Pall I. Olason2, Lilja Stefansdottir2, G. Bragi Walters2, Gisli H. Halldorsson2, Ingemar Turesson5, Martin F. Kaiser4, Asta Försti6, Hartmut Goldschmidt7, Kari Hemminki6, Niels Weinhold8, Niels Abildgaard9, Niels Frost Andersen10, Ulf-Henrik Mellqvist11, Anders Waage12, Annette Juul-Vangsted13, Unnur Thorsteinsdottir2,14, Markus Hansson1,5, Richard Houlston4, Thorunn Rafnar2, Kari Stefansson2,14, Björn Nilsson1,3Laura Duran-Lozano1Hematology and Transfusion Medicine, Department of Laboratory Medicine, 221 84 Lund, Sweden. 2deCODE genetics, Sturlugata 8, IS-101 Reykjavik, Iceland. 3Broad Institute, 415 Main Street, Cambridge MA 02124, USA. 4Division of Genetics and Epidemiology, The Institute of Cancer Research, 123 Old Brompton Road, London SW7 3RP, United Kingdom. 5Hematology Clinic, Lund University Hospital, 221 85 Lund, Sweden. 6German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, D-69120, Heidelberg, Germany. 7Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany, 8Department of Internal Medicine V, University Hospital of Heidelberg, 69120 Heidelberg, Germany. 9Hematology Research Unit, Department of Clinical Research, University of Southern Denmark and Department of Hematology, Odense University Hospital, Denmark. 10Department of Haematology, Aarhus University Hospital, 8200 Aarhus N, Denmark. 11Södra Älvsborgs Sjukhus Borås, Sweden. 12Institute of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Department of Hematology, and Biobank1, St Olavs hospital, Trondheim, Norway. 13Department of Haematology, University Hospital of Copenhagen at Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.14Faculty of Medicine, University of Iceland, Reykjavik, Iceland.


The term heterotopic pregnancy is defined as a uterine pregnancy coexisting with a second pregnancy in an extrauterine location. Spontaneous, full-term heterotopic pregnancy with alive birth is very rare. The diagnosis and management of such exceptionally unique case is difficult. When the patient presented with an advanced labor with no antenatal care follow up and with no risk factors is even more challenging for poorly equipped facilities like ours.A 25 years old gravida 3, para 2  mother presented to the labor and delivery ward of Bele Primary Hospital, Southern Ethiopia with the complaint of pushing down pain of 18 h duration. Immediately after arrival, she gave birth to a 3300gm female neonate spontaneously. After delivery, an abdominal mass was recognized and manual exploration of the uterus was done to look for the presence of after coming second twin but the uterus was empty. On ultrasound examination, there was an alive fetus in transverse lie outside the uterus. With the impression of 2nd twin in a separate horn of bicornuate uterus and to rule out abdominal pregnancy, laparotomy was done. On laparotomy, there was abdominal pregnancy in the Pouch of Douglas with an intact amniotic sac. The sac was attached with the left broad ligament, left ovary, small bowel mesentery, and posterior wall of the uterus. The sac opened, a 1600gm alive female neonate with features of fetal growth restriction and left club foot was delivered. The placenta was detached spontaneously and removed without any complication.The coexistence of spontaneous full-term intrauterine with advanced abdominal ectopic pregnancy is one of the rarest forms of heterotopic pregnancy. Every health professional should bear in mind that intrauterine and extrauterine pregnancy may happen simultaneously and it can progress to term without any symptoms. Ultrasound is the diagnostic method of choice but the existence of an intra-uterine pregnancy cannot rule out ectopic pregnancy. The life-threatening complication of abdominal ectopic pregnancy is bleeding from the detached placental site. Therefore, the decision to remove the placenta should be individualized. The word heterotopic pregnancy is used in place of the older term combined pregnancy . It is dRisk factors for the development heterotopic pregnancy are any event that can lead to scarring of the fallopian tube . Risk faBecause of the rare occurrence of heterotopic pregnancy, there is little agreement on the optimal surgical management . TreatmeHere we present an exceptional case of spontaneous heterotopic pregnancy  which progresses to full term with good perinatal outcome for both the intrauterine and extrauterine fetuses.A 25 years old gravida 3, and para 2  mother presented with the complaint of advanced labor pain of 18 h duration. She came by ambulance transport from a 35 km distant rural health center to Bele Primary Hospital, Wolaita Zone, Southern Ethiopia. The mother did not remember her last normal menstrual period but claims to be amenorrheic for the last 9 months. During the current pregnancy; she had no antenatal care visit, no history of vaginal bleeding, no abdominal pain, and no other danger signs of pregnancy. She has no previous history of pelvic inflammatory disease (PID), and pelvic surgery. She has also no history of contraceptive use. Both her last deliveries were at home with no complications. During the physical examination, her vital signs were in the normal range. Pink conjunctiva and non-icteric sclera. On abdominal examination, 38 weeks sized uterus, fetal heart beat was 148 bpm, cephalic presentation, longitudinal lie, multiple fetal poles were not appreciated, there was 3 uterine contractions in 10 min with moderate strength and bladder was not distended. On the genito-urinary examination (per vagina), cervix was fully dilated, vertex presentation, fetal head visible at vulva, normal position, no sign of caput or molding, the membrane was ruptured with clean amniotic fluid.Basic laboratory investigations were done, her hematocrit level was 35%, and her blood group was “O positive”. Other serologic tests were also done for HIV, Hepatitis, and syphilis and all were negative and urine analysis was also negative for microscope exam.st and 5th minutes respectively by spontaneous vaginal delivery and 3rd stage of labor managed actively.Vaginal delivery summary, this mother gave birth to alive female neonate weighing 3300gm with an Apgar score of 8 and 9 in the 1nd twin and speculum examination also performed to explore the presence of additional cervical canal and double uterus, but only one cervical opening was appreciated. The posterior fornix was bulged.But after the delivery of the neonate, her abdomen shows three tumor features i.e. contracted 20 weeks sized uterus and palpable masses at both left and right upper quadrants. The mass was non-tender and slightly hard and smooth at the left side posterior to the uterus and irregular at the right side Fig. . BimanuaOn ultrasound examination, a fetus was seen in an intact amniotic sac with scanty fluid posterior to the empty uterus. The fetus was in a transverse lie, the head and placenta were at the left upper quadrant below the spleen and its abdomen and extremities were towards the right upper quadrant of her abdomen. The fetal heartbeat was normal and no gross congenital anomaly was identified.nd twin in a separate horn of the bicornuate uterus and to rule out abdominal pregnancy. But due to economic reason, the patient refused referral. Then after getting informed, written consent, and preparing two units of cross-matched whole blood, the patient was taken to OR. Abdomen was entered through a midline vertical skin incision.Referral was planned for the impression of 2st and 5th minutes respectively. The placenta was delivered spontaneously without resistance from its site of attachment. Small bleeders from the placenta detachment site were controlled by multiple ligations. The normal anatomy of the left adnexa was distorted and it was difficult to identify the ovary , the heterotopic pregnancy was diagnosed during laparotomy or laparoscopy [Abdominal pregnancy is an alarming obstetric phenomenon . StrictlThe most frequent site of EP implantation in heterotopic pregnancy is the tube (89.2%) and abdominal heterotopic is one of the rarest types; Tal et al. reported that out of 139 heterotopic pregnancies which are conceived by ART, 3 were abdominal .The diagnosis of abdominal-heterotopic pregnancy is a more complicated task . The mosThese are consistent with our sonographic findings except the malformation was not identified. Otherwise, there was an empty uterus, and the fetal pole was in a transverse lie outside the uterus posteriorly. There was also oligohydramnios with a positive fetal heartbeat. Therefore, the diagnosis of abdominal heterotopic pregnancy was suspected by ultrasound examination and confirmed by laparotomy.The most important issue in managing advanced abdominal pregnancy is the placental management . The masThis is a rare case of spontaneous heterotopic pregnancy with advanced abdominal ectopic in which both the intrauterine and the extra-uterine pregnancies survive. This case was also diagnosed and managed in a rural district hospital by mid-level professionals (non-physician surgeons). Our patient had two home deliveries and has no ANC follow-up during the current pregnancy. She has a low socioeconomic status and she can’t afford referral to a higher institution for better management for both herself and the low birth weight baby. Based on the findings on this case and our literature review, the following conclusions can be made.Every health professional should bear in mind that intrauterine and extrauterine pregnancy may happen simultaneously and it can progress to term without any symptoms. Therefore, a high degree of suspicion is needed when we encounter abdominal mass after delivery of the IUP. Abdominal ectopic is a grave obstetric condition that needs early diagnosis and prompt management. Ultrasound is the diagnostic method of choice but the existence of an IUP cannot rule out ectopic pregnancy, therefore, adnexa should be routinely examined during the first-trimester scan. The life-threatening complication of abdominal ectopic pregnancy is bleeding from the detached placental site. Therefore, the decision to remove the placenta should be individualized.


Yet, despite over 30 years of study, the exact role(s) mtDNA mutations play in driving aging and its associated pathologies remains under considerable debate. Furthermore, even fundamental aspects of age-related mtDNA mutagenesis, such as when mutations arise during aging, where and how often they occur across tissues, and the specific mechanisms that give rise to them, remain poorly understood. In this review, we address the current understanding of the somatic mtDNA mutations, with an emphasis of when, where, and how these mutations arise during aging. Additionally, we highlight current limitations in our knowledge and critically evaluate the controversies stemming from these limitations. Lastly, we highlight new and emerging technologies that offer potential ways forward in increasing our understanding of somatic mtDNA mutagenesis in the aging process.Mitochondria are the main source of energy used to maintain cellular homeostasis. This aspect of mitochondrial biology underlies their putative role in age-associated tissue dysfunction. Proper functioning of the electron transport chain (ETC), which is partially encoded by the extra-nuclear mitochondrial genome (mtDNA), is key to maintaining this energy production. The acquisition of  Aging is broadly defined as the progressive loss of physiological homeostasis over time and is marked by significant alterations at both the molecular and cellular levels that are associated with an ever-increasing probability of pathology and death. These changes have been broadly categorized into nine types or hallmarks . The relWith only a few noted exceptions, mitochondria are the main source of cellular energy in eukaryotes. These organelles process dietary reducing equivalents and oxygen through the electron transport chain (ETC) to produce ATP via oxidative phosphorylation (OXPHOS). Mitochondria are involved in other important cellular functions such as calcium signaling, iron-sulfur cluster biosynthesis, lipid biosynthesis and apoptosis (Reviewed in ). To varAs a consequence of an endosymbiotic event ∼2 billion years ago that gave rise to mitochondria, these organelles have retained a small rudimentary genome that, in animals, is comprised of a circular double-stranded DNA molecule present in dozens to thousands of copies per cell . The relde novo mutation rate compared to nDNA . The miiewed in . In addin a cell . To add n a cell . DespiteA significant body of observational data suggests that the genetic instability of mtDNA in somatic cells is a fundamental phenotype of aging. Numerous studies have shown that mtDNA deletions increase across human tissues during aging . These dthe cell . One sucthe cell . Interesthe cell . Indeed,the cell . While fthe cell .et al. reported that deficient cells have more somatic mtDNA deletions in PD . Indeedns in PD . A similns in PD . Mutationeration . In addineration , sarcopeneration , macularneration , heart dneration , and ulcneration , suggestCollectively, these studies have provided evidence that the accumulation of somatic mtDNA mutations is a phenotype of aging and a potential causative process in several age-related disease, but questions still remain about the true prevalence of somatic mtDNA mutations in the context on normal aging. This is especially pertinent given the heterogeneous nature of tissue decline during aging. To date, no such detailed survey has been conducted, especially with the newest generation of high accuracy methods  resulted in a dramatically accelerated aging phenotype across organ systems and a ∼50% reduction in lifespan  method, which has a significantly reduced background compared to “clone and sequence” approaches , indicating mitochondrial dysfunction, but with no apparent effect on physical performance . Given that this model exhibited no apparent effect on mtDNA copy number or PolG expression level, the reason for the discrepancy in lifespan and aging phenotypes between the two models is unclear.Dissecting the importance of somatic mtDNA mutations in invertebrates has proven to be as equally complicated, if for differing reasons. As originally noted in studies statistically modeling the accumulation of mutations during aging, short-lived and post-mitotic organisms are unlikely to generate and clonally expand mutations to a level that is expected to interfere with tissue function. Consistent with this hypothesis, a erations . Using aerations . Surprisl-γexo- . This mopression . In contD. melanogaster, a heterozygous C. elegans Pol-γexo- mutator model has also been developed (D. melanogaster and mouse Pol-γexo- mutator models. These include a ∼70-fold increase in mtDNA mutations (determined by RMC), an elevation in mitochondrial dysfunction, and shortened lifespan   . APOBEC1APOBEC1) . In cont fitness . Taken tγ mutator models in both vertebrates and invertebrates is that the loss of exonuclease activity affects polymerase processivity and likely interferes with the final processing steps of replication . Moreovγ with single amino acid changes (either Q1009A or H1038A) corresponding to highly conserved amino acids that confer an anti-mutator phenotype in evolutionarily related E. coli DNA polymerase I . Biochey number .E. coli DNA polymerase I demonstrated a number of mutants that increased fidelity of base selectivity by γ homolog, Mip1, identified A256T (A300 in human Pol-γ) as a moderate anti-mutator without any apparent loss in polymerase activity, suggesting that such screening would likely be fruitful in identifying other variants with substantially reduced mutation rates that could be used to directly test if lowering mtDNA mutagenesis extends lifespan . This phenomenon refers to genetic heterogeneity that arises from post-zygotic mutations that propagates within tissues over time due to cell division and tissue remodeling. While the biology underlying this phenomenon is poorly understood, specific mutations are frequently observed to accumulate to high levels within individual cells and tissues and are frequently associated with defects in OXPHOS. These mosaic fields have been observed in numerous different tissue types in both aging and disease and appear to have some level of tissue specificity. Phenotypically, clonal fields are largely characterized by patches of tissues, some quite large, exhibiting a loss in OXPHOS activity. For example, colonic epithelium has shown that normal aging in associated with an increase in clonal fields lacking OXPHOS activity that are the result of mtDNA mutations . Similarde novo events , which proposes that aging is the result of accumulating molecular damage caused by free radical species such as ROS that are a normal by-product of cellular metabolism . CentralOxidation of deoxyguanosine to 8-oxo-7,8-dihydroguanine (8-oxo-dG) lesion in mtDNA has been found to accompany normal aging in multiple tissues . The preMitochondria have several antioxidant defenses thought to prevent or repair oxidative damage to their genome. Several glycosylases with overlapping and complementary activities are active on mtDNA to remove ROS-induced damage to deoxyguanosine . Severalin vivo, which may be the result of lower oxygen concentrations and the presence of reducing equivalents such as thiols in the cellular environments  is reported to be produced more efficiently than 8-oxo-dG ronments . Therefoutations . Third, utations . Consistutations . Examinautations . Lastly,utations . Taken tγ are the primary driver of point mutations seen during aging  and the control region (CR)  . This paion (CR) . This reγ or spontaneous deamination of cytidine and adenosine. However, the possibility remains that ROS may be a driver of deamination itself or an indirect mutagen arising from damage to Pol-γ. One aspect that has received only minor attention is the interplay between DNA damage, repair pathways, and replication and that no one mechanism is the driver of mutagenesis. Experiments that attempt to integrate these different aspects of mtDNA biology are likely to be informative in teasing out the main source(s) of mutations.Much like the experimental work aimed at teasing out the role of mtDNA mutations in driving aging, the molecular source of endogenous mutations has proved as equally enigmatic. Results from several different methods have firmly established that the main source of mutation is unlikely to be 8-oxo-dG, contrary to the long standing free radical theory of aging. Instead, focus has shifted to either base misincorporation errors by Pol-−3, difficult. Another significant limitation is that PCR assays must be optimized for each new genome or target area.The invention of PCR, along with its continued refinement as a key technology, has steadily increased the ability to detect rare mutations down to the level of individual cells or even individual mtDNA molecules . While e−8 (The advent of NGS allows for the digital tabulation of many individual DNA fragments in parallel, offering the unique ability to detect low level nucleic acid species within heterogeneous mixtures. This has led to routine sequencing of the entire mtDNA molecule with more accuracy and dramatically increased throughput, resulting in a significant increase in our understanding of mitochondrial genetics in disease . Early d−8 . This ap−8 .NGS is typically performed on bulk DNA from thousands to millions of cells, which necessarily decouples variant phasing information between any two reads, resulting in a loss of important biological information such as if a variant is homoplasmic or heteroplasmic within any given cell. This limitation is important given the phenotypic threshold effect imparted by different heteroplasmic levels  Wallace. In addide novo mtDNA mutations has, so far, been limited. Due to the much higher mutation rate of mtDNA, most applications have used de novo mutations as a type of barcode to perform cell lineage tracing (The deployment of these technologies to study  tracing . As note tracing . As a by tracing . Moreove tracing . Interes tracing . Applyinin situ with only minor modifications: spatially-aware RNA-Seq (in situ sequencing (To date, most single-cell approaches involve the dissociation of cells, which results in the loss of spatial information regarding how mtDNA mutations are distributed within a tissue. The lack of this information is likely an important aspect that hinders the ability to interpret their potential physiological impact. Spatial genomics is a rapidly emerging field of research that aims to layer spatial information to sequencing data at or near single-cell resolution. Current technologies have largely focused on obtaining the distribution of transcripts within tissues, which, much like single-cell approaches, could be harnessed to obtain spatial distribution of mtDNA heteroplasmies. To date, two main approaches have been developed that are likely amenable to the study of mtDNA mutations  RNA-Seq , and dirquencing . To datequencing .de novo mutations versus inherited and early arising mutations, a confounder in many current models, is also an important question in need of attention. Regardless of the role mtDNA mutations play in driving aging directly, understanding their etiology and biology will likely be important in our understanding of why certain age-related diseases, such as AD or PD, frequently exhibit elevated mutations. In addition, the etiology of mutations could provide clues for more direct drivers of aging, as well as inherited disease causing variants.The accumulation of somatic mtDNA mutations over time is undoubtedly a phenotype of aging. However, establishing the physiological impact of these mutations, especially as it pertains to aging, has proved difficult. A number of animal models have been developed with the intention of directly testing the impact of elevated mutagenesis in driving aging phenotypes. Variability among study design and techniques used to assess somatic mtDNA mutation has made initially strong conclusions more nuanced and, in some cases, has led to apparent conflicting results. The major differences among studies related to the type of sample, the technique chosen to detect somatic mutation, and the analysis have all played a part in adding to the confusion. More rigorous study designs looking at not just lifespan, but also molecular and physiological phenotypes across many tissue and cell types, will be important in more firmly establishing a role of mtDNA mutations in aging. In addition, isolating the effects of aging-linked ex vivo DNA oxidation, and base-calling errors, limiting its ability to detect low level mtDNA mutations, which occur ∼100-fold lower than the error background of these platforms. Error-corrected NGS methods have been developed and are increasingly being used, but conventional NGS is, unfortunately, still the norm. These more modern high accuracy methods have changed our view of the mutagenic processes that act on mtDNA and need to be more frequently used in studies related to somatic mutagenesis.Some missing aspects in our understanding of the biology of mtDNA mutations will undoubtedly be helped by the use of ever improving technologies. Previously used techniques to detect mtDNA mutations, such as standard or long-range PCR, have been slowly replaced by NGS. NGS has substantially improved the accuracy of mtDNA detection and it is now relatively easy to sequence the entire mtDNA in a population. However, NGS is strongly affected by PCR-induced errors, pseudogene artifacts, While an important step forward, most NGS studies are limited by their frequent use of tissue homogenates as a source of DNA, which necessarily removes cell and tissue specific relationships that could provide important information on regarding phenotypic thresholds, clonality, and heteroplasmy that are an important aspect of establishing the impact of potentially pathogenic mtDNA mutations. Laser capture microscopy has partially addressed these issues and has established that clonal expansions of mtDNA mutations are a biological phenomenon. However, the approach is likely too low throughput to deploy at scales high needed to better understand the true burden of clones within a tissue. Embracing emerging single-cell and spatial technologies will allow for a fuller understanding of how mtDNA impact cell and organ function in a more proper biological context. Taken together, it is clear that much remains to be done in order to more fully understand mitochondrial mutagenesis. With the emergence of new capabilities, the future remains bright that a number of long proposed hypotheses related to when, where, and how somatic mtDNA mutations influence aging and disease will soon be answerable.


Talaromyces marneffei causes life-threatening opportunistic fungal infections in immunocompromised patients. It often has a poorer prognosis in non-human immunodeficiency virus (HIV)-infected than in HIV-infected individuals because of delayed diagnosis and improper treatment.A 51-year-old man presented with complaints of pyrexia, cough, and expectoration that had lasted for 15 day. This patient has been taking anti-rejection medication since kidney transplant in 2011.T marneffei pneumonia; post renal transplantation; renal insufficiency; hypertension.Intravenous moxifloxacin was administered on admission. After the etiology was established, moxifloxacin was discontinued and replaced with voriconazole. The tacrolimus dose was adjusted based on the blood concentration of tacrolimus and voriconazole.The patient was successfully treated and followed-up without recurrence for 1 year.T marneffei infection in immunodeficient non-HIV patients who live in or have traveled to T marneffei endemic areas. Early diagnosis and appropriate treatment can prevent progression of T marneffei infection and achieve a cure. Metagenomic next-generation sequencing (mNGS) can aid the physician in reaching an early pathogenic diagnosis. Close monitoring of tacrolimus and voriconazole blood levels during treatment remains a practical approach at this time.A high degree of caution should be maintained for the possibility of  Talaromyces marneffei is responsible for invasive fungal infections, with the highest prevalence in Southeast Asia and southern China. It can cause both local and disseminated infections. The latter are more common, involve the monocyte-macrophage system, and often cause pneumonia before spreading to the liver, spleen bone marrow, lymph nodes, skin, and other organs via lymph and blood circulation. The symptoms reflect the corresponding multi-organ damage. With an increasing occurrence in human immunodeficiency virus (HIV)-negative hosts, talaromycosis has emerged as a serious public health concern.T marneffei pneumonia occurred in an HIV-negative kidney transplantation patient.This case of A 51-year-old man was admitted to our hospital on November 30, 2020 with complaints of pyrexia, cough, and expectoration that had lasted for 15 day. Two weeks before admission, the patient had experienced night sweats and fever below 37.5 ºC without cough, stuffy or runny nose, or other respiratory symptoms. He had sought treatment at a local hospital but his symptoms did not improve after 10 day of intravenous administration of piperacillin-tazobactam and azithromycin; in addition, he developed a cough with yellow, purulent sputum.The patient had been taking immunosuppressants following a kidney transplantation that had been carried out in 2011 for renal failure. His most recent medications were mycophenolate mofetil , tacrolimus , and prednisone . His most recently recorded creatinine levels showed maintenance between 145 µmol/L and 175 µmol/L before admission. The patient denied a history of chronic diseases, such as hypertension or diabetes, as well as of infectious diseases, such as tuberculosis or hepatitis.The patient had been living in Lushan City in Jiangxi Province, southern China, with no history of tobacco or alcohol abuse and no relevant family history. He was a cadre and usually worked in an office.Physical examination at admission showed body temperature of 37.9 °C, respiration of 20 beats/minute, heart rate of 90 beats/minute, and blood pressure of 145/78 mm Hg. There was no enlargement of superficial lymph nodes throughout the body. There were no skin lesions nor joint abnormalities. A few wet rales could be heard in the right lower lung. The liver and spleen were not felt under the ribs on abdominal palpation.9/L, high neutrophil count of 80% , low hemoglobin of 90 g/L , and a normal platelet count. Hypoproteinemia  and elevated creatinine , blood 1-3-β-D-Glucan , blood galactomannan , and C-reactive protein  were observed. Liver function, electrolytes, arterial blood gases, procalcitonin, T-spot tuberculosis test, HIV antibody, and blood cryptococcus capsular antigen levels were all normal or negative. Blood T cell subsets included low lymphocytes of 12.33% , high T lymphocytes of 96.48% , normal CD4 + T cells of 618.48/µL, and low CD8 + T cells of 351.23/µL (404–754/µL).Routine blood tests revealed a normal white cell count of 9.22 × 10After the patient was transferred to our hospital, intravenous moxifloxacin was administered and the mycophenolate mofetil dose was decreased to 250 mg, twice daily.T marneffei , and a 7-day culture of BALF yielded biphasic T marneffei  smear found sausage-like spores with a central septum Fig. . On DeceChest computed tomography (CT) at the local hospital showed a solid lesion in the right lower lung. A repeat chest CT at our hospital showed an enlarged lesion Fig. A.T marneffei pneumonia.We did not find other disseminated lesions after a thorough evaluation, including of the abdomen, brain, lymph nodes, skin, and joints. The patient was diagnosed with On December 4, 2020, moxifloxacin was discontinued and replaced with voriconazole  because the patient’s creatinine clearance was less than 50 mL/min. The tacrolimus dose was adjusted frequently, especially in the first month, to maintain the blood tacrolimus and voriconazole concentrations within the proper concentration range  patients, following tuberculosis and cryptococcus. Highly active antiretroviral therapy has led to a decline in HIV-related T marneffei infections, while infections in HIV-negative patients have increased. The comorbidities present in patients with T marneffei infections include malignancies, organ transplantation, autoimmune diseases, and some emerging conditions such as adult-onset immunodeficiency associated with anti-interferon gamma antibodies, T lymphocyte-depleting immunosuppressive drugs, and novel targeted anticancer agents such as anti-CD20 monoclonal antibodies and kinase inhibitors. Because of its insidious onset and rapid progression, the diagnosis of talaromycosis is often delayed, which leads to high fatality rate. Furthermore, talaromycosis mortality is higher in HIV-negative than in HIV-positive patients. Early diagnosis of talaromycosis is both crucial and challenging.T marneffei is the only thermally dimorphic penicillium, with a mold phase at 25 to 28 ºC and producing a diffusible wine-red pigment and brush-shaped microscopic hyphae microscopically, and a nonpigmented pathogenic yeast phase pigment at 37 ºC. Confirmation of talaromycosis requires the isolation of biphasic penicillium from specimen cultures.T marneffei was considered. Hence, the specimen was incubated at both 26 and 37 ºC. It was not until the 7th day after the lavage fluid specimen was collected that it was confirmed that the causative organism of the patient’s infection was indeed T marneffei. Hien et al indicated that the culture may even take up to 14 days for identification. In comparison, the actual testing time for mNGS was only 24 hours, excluding the logistical time for specimen delivery. It was this valuable time lag that allowed clinicians to quickly target the pathogen and adjust the treatment plan in time so that the disease did not spread further.In this case, the clinician communicated with the microbiology technologist to suspect a fungal possibility due to the patient’s immunocompromised condition. After fluorescence staining revealed spores with transverse septa, the possibility of  Li et al found that mNGS had a diagnostic sensitivity of 88.89% and specificity of 74.07% with an agreement rate of 77.78% compared to specimen culture. Compared with culture smears and polymerase chain reaction, mNGS had a diagnostic sensitivity of 77.78% and a specificity of 70.00%.In addition to the time consuming nature of culture, its positive rate is not as good as it could be. Liu et al confirmed a higher positive rate for BALF mNGS (64%) than for BALF culture (28%).Because of the long time, low accuracy and low positive rate of traditional culture, it often leads to delayed diagnosis and inappropriate use of antibiotics. Although mNGS has some inadequacies, such as interference with human-derived nucleic acids, report interpretation, and high cost, it is still increasingly used in clinical practice because of its high throughput, high timeliness, high accuracy, and broad coverage. Furthermore, BALF-based mNGS is recommended for diagnosing pulmonary fungal infections due to its diagnostic advantages over conventional tests.T marneffei. Fluorescent dyes that specifically bind to chitin and dextran in the fungal cell wall can be used to label fungi, to allow observation of cellular morphology by fluorescence microscopy. Because it is rapid, economical and direct, fluorescence staining is now widely used in clinical practice.In this case, fluorescent staining of BALF smears suggested that the pathogen was ,10 The drug manufacturer suggested that the concurrent tacrolimus dose be reduced by one-third; other case reports described an 80% to 90% reduction.,11 One report noted that the voriconazole dose was also reduced as appropriate.As the patient was found to have renal insufficiency before the onset of infection, oral voriconazole was chosen. When voriconazole is used in combination with tacrolimus, which is also metabolized by CYP3A, the blood concentration of tacrolimus could quickly rise to very high levels. Nevertheless, because of individual differences, genotype polymorphisms, and differences of pharmacokinetics and clinical backgrounds, there are no consistent criteria or recommendations for adjusting blood tacrolimus concentration in patients with invasive fungal infection after organ transplantation. Fortunately, in our case, with intensive monitoring, the tacrolimus dose was adjusted to maintain a blood concentration of 3 to 6 ng/mL. The voriconazole blood concentration also remained within the effective range . The patient was finally cured and renal function was maintained at the pre-onset level.The optimal therapeutic windows for tacrolimus in patients with renal transplants are 5 to 15 µg/L at 1 to 3 month after surgery and 3 to 8 µg/L beginning at 12 month after surgery.T marneffei infection in HIV-negative immunocompromised patients with a history of tourism or residence in T marneffei endemic regions. mNGS can powerfully assist physicians in quickly and accurately targeting the pathogen, preventing further spread and worsening of the infection. Fluorescent staining is a diagnostic hint for suspected fungal infections. Individual differences and narrow treatment windows for tacrolimus require close monitoring of its blood concentration during the administration of antifungal treatment with voriconazole or other azole drugs.In conclusion, clinicians should be alert to the possibility of The authors are grateful to Dr Hui Chen for providing photos of the microorganism.Fang X-L conceived the study and developed the search strategy, supervised the patient’s diagnosis and treatment during the entire process, and put forward valuable opinions, and edited the manuscript; Cai D-H and Wang J conducted the literature review and participated in the patient’s diagnosis and treatment; Cai D-H produced the draft of the manuscript; All authors contributed to the final manuscript.Conceptualization: Xiao-Lin Fang.Formal analysis: Xiao-Lin Fang.Methodology: Jun Wang.Writing – original draft: De-Han Cai.Writing – review & editing: Xiao-Lin Fang.


The pDTT derivatives studied include polymers with simple thiohexyl end-caps or modified with AQ or methyl groups by Steglich esterification. All polymers were shown to be depolymerized using catalytic amounts of electrons delivered by AQ•−. For pDTT, as little as 0.2 electrons per polymer chain was needed to achieve complete depolymerization. We hypothesize that the reaction proceeds with AQ•− as an electron carrier (either molecularly or as a pendant group), which transfers an electron to a disulfide bond in the polymer in a dissociative manner, generating a thiyl radical and a thiolate. The rapid and catalytic depolymerization is driven by thiyl radicals attacking other disulfide bonds internally or between pDTT chains in a chain reaction. Electrochemical triggering works as a general method for initiating depolymerization of pDTT derivatives and may likely also be used for depolymerization of other disulfide polymers.We report the use of electrogenerated anthraquinone radical anion (AQ• First, 55 μM AQ•− was electrogenerated by applying an electrolysis potential of −1.07 V. The stability of AQ•− is observed to be relatively good until a degassed solution of pDTT, HTpDTT, or (Me)pDTT (200 μM resulting concentration) is added (defined as time zero). For pDTT and HTpDTT, AQ•− is consumed within 1–2 s, while, for (Me)pDTT, a sharp decrease in [AQ•−] to ~25 μM is detected within seconds, whereafter a slow decrease is observed, reaching ~15 μM after 20 s and zero after 70 s , dimethyldisulfide (DMDS), and 2,2′-dithiodipyridine (DTDP) in the presence of AQ. These compounds nicely correspond to or mimic the end product, the backbone, and the end-caps of the polymers.−) and −1.7 V vs. SCE (AQ•− to AQ2−), respectively (−) still appears Nernstian. In contrast, the second wave at −1.7 V (AQ•− to AQ2−) exhibits a noticeable increase in the peak current, coming along with a diminishing current of the oxidation wave at −1.5 V (AQ2− to AQ•−) on the anodic sweep. The anodic peak at −0.8 V (AQ•− to AQ) is of similar size as before but begins to overlap with the oxidation of the thiolates at −0.2 V. This would suggest that transfer of electrons to (Me)pDTT from the more potent electron donor, AQ2−, can take place, while AQ•− has no such ability on the time scale of a voltammetric cycle. Furthermore, the additional reduction peaks observed at −2.7 V indicate that, besides direct reduction of the polymer itself, other disulfide-containing species, originating from the depolymerization, may contribute to these signals.Reduction of AQ takes place as two Nernstian one-electron transfer processes at −0.9 V vs. SCE (AQ to AQ•ectively a. The voectively a. On the−) looks similar to that of AQ alone, while the second reduction wave comprising two peaks shifts in a positive direction. The reduction wave of the polymer itself shifts towards a more negative potential and becomes larger in the presence of AQ. For HTpDTT the electron transfer pertaining to the first reduction peak at −0.9 V (AQ to AQ•−) is Nernstian, while the second reduction peak shifts to a less negative potential. The reduction peak for the polymer itself shifts to a more negative potential (−2.7 V vs. SCE) and becomes broader, but with little change to the peak current.Cyclic voltammograms of pDTT and HTpDTT with and without AQ can be found in the − to AQ and dihydroanthraquinone , wi, wi®  is more profound. Earlier studies on indirect reduction of simple disulfides demonstrated that electrogenerated AQ•− can be used to reduce disulfides to thiolates on a time scale of min/h , together with cDTT, contain hydroxyl groups, which may protonate AQ•emically . Both th of cDTT , which d of cDTT . In thiseresting  as all hRegarding the three model compounds, both DMDS and cDTT comprise aliphatic disulfide bonds, thus mimicking the end-caps of HTpDTT as well as the dialkyl disulfide bonds along the backbone of all polymers. Note that cDTT also contains hydroxyl groups and is cyclic, yet without ring tension. Likewise, DTDP is meant to serve as a model compound mimicking pyridyl disulfide end-caps. Acknowledging that the four polymers, pDTT, (Me)pDTT, (AQ)pDTT, and (AQ)(Me)pDTT, contain a mixed alkyl pyridyl disulfide end-cap, the reduction potential of this end-cap should thus be located somewhere between those of DMDS and DTDP.kDMDS = 2 × 102 M−1 s−1, kDTDP = 105 M−1 s−1), because of a greater extent of electron delocalization onto the pyridyl groups. This decreases significantly the reorganization energy of the stepwise dissociative electron transfer  from Fischer Scientific  and EDC•HCl from Fluorochem . All chemicals were used without further purification. The polymers pDTT, (Me)pDTT, (AQ)pDTT, and (AQ)(Me)pDTT were synthesized following previously established protocols with a few modifications  = 2 mM, [DMDS]/[DTDP][RSSR] = 5/5/3.2 mM, half peak potentials of AQ locked at −0.87 and −1.61 V vs. SCE at sweep rate = 1 V s−1  = 2 mM, [DMDS]/[DTDP] = 24 mM, half peak potential of AQ locked at −0.87 V vs. SCE at sweep rate = 1 V s−1  = 3 mM, and ~1.5 mg mL−1 of polymers were added, providing polymer concentrations for pDTT (0.60 mM), HTpDTT (0.41 mM), (Me)pDTT (0.39 mM), (AQ)pDTT (0.39 mM), and (AQ)(Me)pDTT (0.31 mM) as listed. The catholyte solution was purged with argon for at least 10 min prior to recordings. A cyclic voltammogram was recorded just prior to electrolysis to determine the cathodic peak potential of AQ (or pendant AQ); electrolysis was conducted at a potential 150 mV more negative than this potential and stopped when a specific charge in the range of 0.50–0.96 C was consumed (corresponding to ~3 electrons per polymer chain in each case).Electrolysis was conducted using a CH Instrument (601D) potentiostat in a two-necked two-chamber H-cell with 0.03 M Bu−1 of polymer, i.e., HTpDTT (0.27 mM), (Me)pDTT (0.26 mM), (AQ)pDTT (0.26 mM), and (AQ)(Me)pDTT (0.21 mM), and stopped after consumption of 0.055–0.072 C. Finally, electrolysis of pDTT passing 0, 0.05, 0.1, 0.2, 0.5, 1.0, 2.0, and 3.0 equiv. of electrons per polymer chain was conducted with pDTT (0.40 mM); volume of catholyte = 15 mL and [AQ] = 3 mM. Aliquots for SEC were collected after the specific amount of charge was consumed.Likewise, electrolyzes with passing of 0.5 electrons per polymer chain were conducted using 1 mg mL4NBF4/DMF purged with argon. With a dip-in probe inserted in the catholyte, spectra of AQ•− were recorded and compared with those reported in literature [− was monitored at the wavelength 556 nm with a time resolution of 0.1 s. Lambert–Beer law was used to calculate [AQ•−] from the absorbance at 556 nm and by employing −1 cm−1. Solutions of AQ•− were prepared by electrochemical reduction of 2 mM AQ in 0.1 M Bu4NBF4/DMF. The electrolysis was stopped once the absorbance at 556 nm reached 0.6 corresponding to [AQ•−] = 55 μM. While recording the absorbance at 556 nm, 100 μL of a degassed polymer solution of pDTT, HTpDTT, or (Me)pDTT was injected to achieve [polymer] ≈ 0.2 mM. The decay of [AQ•−] was traced from this point on, defined as t = 0.UV–Vis spectra were collected from the cathode chamber of an H-cell using an Agilent Cary-60 UV–Vis absorption spectrometer with a dip probe from C-Tech with pathlength of 1 cm. The cathodic compartment was filled with 3 mL solution containing 2 mM AQ in 0.1 M Buterature . Absorba−. Only a catalytic amount of electrons was needed to achieve full depolymerization, which would be in line with an intermolecular chain reaction from a mechanistic point of view. The reaction is rapid (within seconds) and applicable to all derivatives regardless of end-cap and whether they contain an internal proton donor or not. Triggering can be completed using either AQ in solution (intermolecular) or pendant AQ moieties (intramolecular). We propose a mechanism where dissociative electron transfer from AQ•− to a polymer disulfide bond generates a thiyl radical and a thiolate. The former may be engaged in reaction with other disulfide bonds, creating a new disulfide and a thiyl radical, eventually leading to smaller disulfides. The proposed mechanism explains both the catalytic nature and rapidity of these depolymerizations.We successfully synthesized poly(dithiothreitol) derivatives by exchanging end-caps and/or introducing various pendant groups via Steglich esterification. All polymers were shown to be depolymerized once triggered by electrogenerated AQ•