bluuebunny/crossref_metadata_2025 huggingface dataset:
Manifestation of TASER drive stun burn marks on fabrics
Authors: Ruffo Hannah Elizabeth , Liscio Eugene , Cao Wanying , Zhou Yu Ran , Doucette Corrin
Published: September 2022

The TASER® is a type of conducted energy weapon (CEW) used with increasing frequency by law enforcement to subdue subjects in circumstances where compliance is necessary. When operated in the drive stun method of deployment, the electrodes at the head of this CEW are intended to make direct contact with a surface, generating heat and light which may result in burn marks as a by‐product of the electrical discharge that occurs. This research aims to tackle a crucial gap in CEW research that fails to address the appearance of burn marks on fabrics. A drive stun duration (DSD) of 1, 3, and 5 s was used with three TASER models (X26P, X2, & TASER 7) on three fabrics (white 100% cotton, 100% polyester, 35:65 cotton‐polyester blend) with an underlying backing of pork hock. Using a Keyence VHX‐6000 confocal microscope, high magnification images were taken to observe any qualitative changes to the fabric. On polyester fabric, with increasing DSD, darker brown discoloration occurred. Additionally, on polyester fabric, the spatial orientation of the burn marks corresponded with that of the electrodes at the muzzle of each TASER model. These features enabled the correct identification of the TASER model and DSD on polyester fabric in the blind tests performed. Evidence of burn marks on cotton and blend fabrics were both limited and inconsistent such that no features were sufficiently unique to link them to any TASER model or DSD. Despite this, overall features such as discoloration and the formation of holes on these fabric types may be sufficiently unique to suggest the use of a CEW.
A Middle Pleistocene Glaciation Record from Lacustrine Sediments in the Western Tibetan Plateau and Discussion on Climate Change
Authors: ZHAO Zhenming , JI Wenhua , FU Chaofeng
Published: September 2022

The Tibetan Plateau is an important area for studying global climate change, but the answers to many scientific problems remain unknown. Here, we present new information from the lacustrine sedimentary record in the western Tibetan Plateau, related to the third most‐recent glaciations. Continuous sediment data, including sporopollen, particle size, total organic carbon, mass susceptibility, CaCO3, CaSO4, BaSO4 contents and chronological data, were reconstructed and revealed that climate and environmental conditions obviously and distinctly changed between 600 and 700 thousand years ago. In comparison, the data obtained from the Guliya ice core in this area also corresponds to the global glacial climatic characteristics recorded in basin sediments in the eastern and southeastern regions of the plateau and to the information obtained from ice cores in the Antarctic and Arctic regions. In this study, we conclude that the main reason for the glaciations and new tectonic movement must be a geomagnetic polarity reversal 774 thousand years ago (from Matuyama to Brunhes). Indeed, the results of this study suggest that the described reversal event might have influenced the current global climate pattern and will continue to impact climatic changes in the future.
A Comparison Study of Synkinematic Illite Isolation, Quantitative X‐ray Powder Diffraction, and K‐Ar Dating for Direct Fault Gouge Analyses
Authors: ZHENG Yong , LI Haibing , LI Junjie , ZHANG Guohe , SI Jialiang
Published: September 2022

K‐Ar dating of synkinematic illite is increasingly recognized as a central method to constrain the timing of shallow crustal faulting. Methods of efficient sample preparation and quantitative identification of illite polytypes are critical to acquiring K‐Ar isotope data for authigenic clays. In this respect, we compared the commonly used clay size separation method through centrifugation with vacuum filtration technology, showing that the former is prone to extract fractions with finer particle sizes under similar conditions, thus improving the error in the authigenic end‐member age. Additionally, we demonstrated that the side‐packed mounting method for X‐ray diffraction analysis can significantly enhance the randomness in powder samples, thus improving the quantification accuracy compared with the front‐packed and back‐packed methods. The validity of our quantification method was confirmed by comparing Profex® modeling patterns with a suite of synthetic mixtures of known compositions, yielding an average analytical error of 3%. Dating results of these artificial mixtures and the reference materials indicated that a large range in percentages of detrital illite and a sufficient amount of age data will produce reliable results for ages of both extrapolated end‐members. However, if the range is limited, the extrapolated age close to those of datasets is still reliable.
Pazopanib for treating rhabdomyosarcoma in adult patients with poor performance status: A case report
Authors: Nishii Yuuya , Sasaki Jun , Sudou Misa , Yano Ryo , Tokisawa Saeko , Takaki Reiko , Tokito Takaaki , Hoshino Tomoaki
Published: September 2022

Rhabdomyosarcoma (RMS) is a common soft tissue sarcoma usually observed in children. However, RMS rarely occurs in adults. The prognosis of adult RMS is poor and a standard chemotherapy regimen has not yet been established. Herein, we report the case of a 60‐year‐old Japanese woman with primary anterior mediastinal alveolar RMS (T3N0M0, stage III). The tumor increased aggressively despite first‐line treatment with doxorubicin (60 mg/m2 every 3 weeks for 1 cycle) and second‐line treatment with eribulin (1.4 mg/m2 every 3 weeks for 2 cycles). Although her shortness of breath and chest tightness worsened as the tumor compressed her heart and left main bronchus, and her performance status (PS) decreased to 3, third‐line treatment with pazopanib (800 mg once daily) was commenced. The treatment led to suppression of tumor growth and resulted in 4‐month progression‐free survival. Therefore, in cases of adult RMS, considering pazopanib treatment as an option may be beneficial, even with previous ineffective treatments or poor PS.
Bioavailability and cardiovascular effects of adrenaline administered by Anapen 500 μg auto‐injector in healthy volunteers
Authors: Duvauchelle Thierry , Robert Philippe , Donazzolo Yves , Loyau Sabrina , Orlandini Bernard , Lehert Philippe , Lecomte Jeanne‐Marie , Schwartz Jean‐Charles
Published: September 2022

Aims

Anaphylaxis guidelines recommend intramuscular adrenaline, commonly 300 μg administered using an auto‐injector device. However, overweight/obese patients may require a higher adrenaline dose for adequate cardiovascular (CV) response. This study evaluated the pharmacokinetics (PK) and pharmacodynamic (PD) CV profiles after a single 500 μg adrenaline injection via Anapen auto‐injector in healthy normal weight males and otherwise healthy, overweight or obese females.

Methods

In this exploratory open‐label, single‐centre study, 54 healthy volunteers aged 18‐50 years received a single 500 μg adrenaline injection (Anapen auto‐injector) in the thigh (antero‐lateral middle third [18 males] or antero‐inferior third [36 females]). Assessments included depot depth (ultrasonography), plasma adrenaline levels (liquid chromatography‐tandem mass spectrometry) and heart rate (HR; ECG Holter monitor).

Results

Ultrasonography showed that 82.4% of normal weight males received intramuscular injections; all overweight and obese females received subcutaneous injections. Anapen injection produced rapid increases in circulating adrenaline levels and significant increases in systolic blood pressure (SBP) and HR. Second peak plasma adrenaline concentrations (Cmax2) were reduced, and time to Cmax2 increased in overweight and obese females compared with males with normal body mass index; area under the curve (0–240 min) (AUC(0‐240)) was increased in overweight and obese females. Obese females had reduced maximal SBP values compared with normal weight males or overweight females; overweight and obese females had markedly different HR time courses compared with normal weight males.

Conclusion

A 500 μg adrenaline injection via Anapen produced rapid PK/PD changes in normal weight, overweight and obese subjects, irrespective of intramuscular or subcutaneous injection, and was well tolerated.
Telementoring for endoscopic submucosal dissection in vivo training
Authors: Yip Hon Chi , Uedo Noriya , Lau Louis Ho‐Shing , Hirata Daizen , Sano Yasushi , Chiu Philip Wai‐yan ,   the Asian Novel Bio‐imaging and Intervention Group (ANBIIG)
Published: September 2022

The provision of endoscopic training was significantly disrupted during the coronavirus disease (COVID‐19) pandemic. It is difficult to provide training on endoscopic submucosal dissection (ESD) due to the complexity of the procedure and the shortage of local trainers. We have designed and conducted a simulation training course with telementoring, incorporating the concept of rapid cycle deliberate practice (RCDP). After a short tutorial on basic setup and maneuvering, the participants undergo 2 h of training on a live anesthetized pig to acquire the necessary skills for ESD. Two overseas experts were involved virtually in real time as telementors. A video camera was set up at each station, and both external and endoscopic views were transmitted live between the animal laboratory and telementors via the Zoom application. The overseas experts actively engaged in the simulation by giving live feedback and instructions to participants using visual aids supported by the meeting application. The training model utilized the concept of RCDP, where repeated immediate feedback and discussion would be carried out to enhance the efficiency of learning. Eighteen trainees were invited to participate in the course, six of them instructed by overseas telementors. Four ESD procedures were performed by participants under telementoring and achieved 100% en bloc resection without perforation. The times required for each ESD were similar with telementoring than that of on‐site mentors. The establishment of telementoring has enabled knowledge and skill transfer of complex endoscopic procedures of ESD. With the limitations of international travel, this could be an alternative model allowing remote training, particularly when local experts are not readily available.
Cost‐effectiveness of guideline‐based care provision for patients with diabetes‐related foot ulcers: A modelled analysis using discrete event simulation
Authors: Zhang Yuqi , Carter Hannah E. , Lazzarini Peter A. , Cramb Susanna , Pacella Rosana , van Netten Jaap J. , Cheng Qinglu , Derhy Patrick H. , Kinnear Ewan M. , McPhail Steven M.
Published: September 2022

Aims

The provision of guideline‐based care for patients with diabetes‐related foot ulcers (DFU) in clinical practice is suboptimal. We estimated the cost‐effectiveness of higher rates of guideline‐based care, compared with current practice.

Methods

The costs and quality‐adjusted life‐years (QALYs) associated with current practice (30% of patients receiving guideline‐based care) were compared with seven hypothetical scenarios with increasing proportion of guideline‐based care (40%, 50%, 60%, 70%, 80%, 90% and 100%). Comparisons were made using discrete event simulations reflecting the natural history of DFU over a 3‐year time horizon from the Australian healthcare perspective. Incremental cost‐effectiveness ratios were calculated for each scenario and compared to a willingness‐to‐pay of AUD 28,000 per QALY. Probabilistic sensitivity analyses were conducted to incorporate joint parameter uncertainty.

Results

All seven scenarios with higher rates of guideline‐based care were likely cheaper and more effective than current practice. Increased proportions compared with current practice resulted in between AUD 0.28 and 1.84 million in cost savings and 11–56 additional QALYs per 1000 patients. Probabilistic sensitivity analyses indicated that the finding is robust to parameter uncertainty.

Conclusions

Higher proportions of patients receiving guideline‐based care are less costly and improve patient outcomes. Strategies to increase the proportion of patients receiving guideline‐based care are warranted.
Pharmacological potential of ants and their symbionts – a review
Authors: Agarwal Surbhi , Sharma Garima , Verma Kavita , Latha Narayanan , Mathur Vartika
Published: September 2022

Ants (Hymenoptera: Formicidae) play an important role in the pharmacological and food industry due to their therapeutic and nutritional properties. Being the most abundant eusocial insects in the world, ants also serve as a repository of bioactive compounds, which are utilized for their ecological interactions and defense. Ants have been used for the treatment of various diseases including asthma, cancer, arthritis, and other microbial infections in both modern and ethnic medicine. This is attributed to various compounds, such as antimicrobial peptides, biogenic amines, alkaloids, and flavonoids obtained from ant venom as well as whole‐body extracts. However, most of these compounds have not been characterized till date. Ant endosymbionts are also known to contribute to some of these properties and to play a crucial role in digestion, protection from enemies, nutritional upgrading, nitrogen recycling, and reproductive manipulation of their host. Hence, they have been used in pharmaceutical, food, and cosmetic industries due to their ability to produce various bioactive compounds. In contrast, ectosymbionts specifically help in pathogen defense. However, the potential of ant symbionts in the welfare and production of therapeutic compounds is not extensively studied. This review mainly focuses on the role of ants and their symbiotic microbes as a potential source of bioactive compounds in therapeutic interventions for exploring future possibilities in drug development research.
Three perspectives on the prediction of chemical effects in ecosystems
Authors: Schneeweiss Anke , Juvigny‐Khenafou Noël P. D. , Osakpolor Stephen , Scharmüller Andreas , Scheu Sebastian , Schreiner Verena C. , Ashauer Roman , Escher Beate I. , Leese Florian , Schäfer Ralf B.
Published: September 2022

The increasing production, use and emission of synthetic chemicals into the environment represents a major driver of global change. The large number of synthetic chemicals, limited knowledge on exposure patterns and effects in organisms and their interaction with other global change drivers hamper the prediction of effects in ecosystems. However, recent advances in biomolecular and computational methods are promising to improve our capacity for prediction. We delineate three idealised perspectives for the prediction of chemical effects: the suborganismal, organismal and ecological perspective, which are currently largely separated. Each of the outlined perspectives includes essential and complementary theories and tools for prediction but captures only part of the phenomenon of chemical effects. Links between the perspectives may foster predictive modelling of chemical effects in ecosystems and extrapolation between species. A major challenge for the linkage is the lack of data sets simultaneously covering different levels of biological organisation (here referred to as biological levels) as well as varying temporal and spatial scales. Synthesising the three perspectives, some central aspects and associated types of data seem particularly necessary to improve prediction. First, suborganism‐ and organism‐level responses to chemicals need to be recorded and tested for relationships with chemical groups and organism traits. Second, metrics that are measurable at many biological levels, such as energy, need to be scrutinised for their potential to integrate across levels. Third, experimental data on the simultaneous response over multiple biological levels and spatiotemporal scales are required. These could be collected in nested and interconnected micro‐ and mesocosm experiments. Lastly, prioritisation of processes involved in the prediction framework needs to find a balance between simplification and capturing the essential complexity of a system. For example, in some cases, eco‐evolutionary dynamics and interactions may need stronger consideration. Prediction needs to move from a static to a real‐world eco‐evolutionary view.
Patients with COVID‐19 share their experiences of recovering at home following hospital care transitions and discharge preparation
Authors: Ganton Joanne , Hubbard Amberley , Kovacs Burns Katharina
Published: September 2022

Introduction

Patients discharged following hospitalization for COVID‐19 require clear discharge protocols, information resources and communications to adequately prepare them to safely and successfully transition from hospital to home. Our study focuses on the patients' transition to recovering at home including their hospital discharge preparation and hospital experiences.

Methods

A qualitative descriptive study design involved interviewing patients who had been hospitalized for COVID‐19 in one urban Alberta, Canada centre. Purposive sampling was used to select patients from a centralized COVID‐19 hospital patient database stratified by month between March 2020 and February 2021. Other inclusion criteria (e.g., sex and age) were also considered. Semi‐structured interviews with patients were recorded, transcribed and analysed using thematic analysis. Data sufficiency and saturation were determined.

Results

Twelve patients shared their lived experiences and recovery journey from COVID‐19. Themes were reported under three main areas as framed by the study aim—the current status of patients recovering at home, including the supports they used to manage; their discharge process and preparation to go home; and their various hospital‐related experiences. Suggestions for improving aspects of the patient journey were also captured.

Conclusion

Findings provided details of the needs, information gaps and what matters most to patients when they are recovering from COVID‐19 at home, including their preparation to safely and successfully transition from hospital to home (i.e., feeling well prepared to go home, including being adequately assessed and having clear discharge protocols and communication). Key learnings were applied to improve or develop patient discharge and transition resources.

Patient or Public Contribution

A patient/family advisor and patient experience partners were involved throughout the study, codeveloping all aspects, from the study design to the reporting and application of the findings. Leading into the study, patient experiences and feedback regarding the home from hospital recovery journey informed multiple aspects, including the codevelopment of the interview guide.
Pilot evaluation of PrEP EmERGE – A novel digital health innovation designed to support sexual health clinics and HIV‐PrEP users
Authors: Fitzpatrick Colin , Richardson Daniel , Sherriff Nigel , Whetham Jennifer
Published: September 2022

Objective

We aimed to evaluate the usability and acceptability of a co‐designed mobile health (mHealth) application (PrEP‐EmERGE) within a digital health pathway to support HIV pre‐exposure prophylaxis (PrEP).

Methods

This was a cross‐sectional study to evaluate the usability and acceptability of the PrEP‐EmERGE app. Data were collected via an online survey sent to all PrEP EmERGE users in September 2021. Usability was assessed with a validated usability tool, the System Usability Scale (SUS). Acceptability was assessed using modified patient‐reported experience measures (PREMs). Quantitative data were analysed using descriptive and/or inferential statistics and qualitative data (free text responses) using thematic analysis.

Results

In total, 81/133 (61%) active PrEP EmERGE users completed the online survey, which was available directly from their PrEP EmERGE app: 78/81 (96%) identified as cis‐male, 74/81 (91%) reported their ethnicity as ‘white’, 69/81 (85%) reported daily PrEP use, 7/81 (9%) reported using an event‐based dosing schedule, and 5/81 (6%) were switching between dosing schedules. Overall, the median SUS score was 78/100 (interquartile range: 70–92). There were no differences in median SUS scores by PrEP dosing schedules (p = 0.78) or months of experience of using the app (p = 0.31). Overall, 73/81 (90%) would recommend the PrEP EmERGE app to a friend and 78/81 (96%) rated their satisfaction of the app as excellent, good or satisfactory. The free text responses generated three key themes: accessibility (for results and information); autonomy [taking responsibility for their (sexual) health] and functionality (including technical recommendations for app development and the digital health pathway).

Conclusions

Innovative, co‐designed digital health pathways, such as PrEP EmERGE can help sexual health services to manage increasing numbers of people accessing PrEP – ensuring that they retain access for those who need to be seen face‐to‐face. We report high levels of acceptability and usability during the first 4 months of this novel pathway.
Sex difference in fatty acid composition of six marine teleosts
Authors: Zhang Feiran , Liu Jiahao , Bi Qingzhu , Ma Qiang , Wei Yuliang , Liang Mengqing , Xu Houguo
Published: September 2022

This study investigated the sex difference in fatty acid (FA) composition of six wild marine fish species, namely, Cleisthenes herzensteini, Platichthys bicoloratus, Pseudosciaena polyactics, Platycephalus indicus, Alosa sapidissima and Scomberomorus niphonius. The coefficient of distance value between sexes (Dsex) and multi‐variate similarity of percentages analysis (SIMPER) revealed universal existence of sex difference in FA composition, particularly in gonad, intestine and liver. Nonetheless, this sex difference was highly dependent on fish species. In general, DHA, 18:1n‐9, 16:1n‐7, 16:0 and EPA appeared to be the TOP FAs differentially abundant between sexes.
Spatial heterogeneity in pH, body size and habitat size generates ecological opportunity in an evolutionary radiation
Authors: Smith Carl , Zięba Grzegorz , Spence Rowena , Przybylski Mirosław
Published: September 2022

Much of the biological diversity we see today is thought to be the product of evolutionary radiation, the rapid proliferation of species from a single ancestor into multiple discrete forms. Spatial heterogeneity in environmental variables has been proposed as creating the necessary ecological opportunity to stimulate evolutionary radiation. Nonetheless, the ecological mechanisms generating and maintaining diversity in spatially heterogeneous environments are not fully understood. The authors investigated the role of strong spatial heterogeneity in generating ecological opportunity in an evolutionary radiation of freshwater populations of the three‐spined stickleback (Gasterosteus aculeatusL.) on the island of North Uist using a spatially explicit Bayesian model. The authors identified pH, loch surface area and body size as predictors of variance in the number of lateral plates that comprise anti‐predator armour inG. aculeatus. An East–West gradient of pH, a product of the distinctive environment of North Uist, generates a robust selective environment facilitatingG. aculeatusevolutionary radiation. Larger lochs were associated with atypical phenotypes, possibly related to larger population sizes and greater selection efficiency. An association between pH and lateral plate number is likely an effect of body size, with a positive relationship between body size and lateral plate number that is mediated by swimming efficiency inG. aculeatus.
How does air pollution affect corporate information environment?
Authors: Xiao He
Published: September 2022

In this article I examine the causal impact of air pollution on the corporate information environment. My empirical findings indicate that firms located in cities with severe air pollution tend to experience higher information asymmetry. The economic mechanisms behind this casual association come from the negative impact of air pollution on corporate governance and managerial human capital. Specifically, the positive causal association between air pollution and corporate information asymmetry is less pronounced for firms with stronger corporate governance and better managerial ability. In addition, firms exposed to more severe air pollution tend to have fewer board meetings. All main empirical findings are robust to a system generalized method of moments estimation, two‐stage least squares tests using thermal inversions as an instrumental variable, regression discontinuity tests based on the Huai River policy, and difference‐in‐difference estimations based on the 2013 Clean Air Action Plan in China. Furthermore, all main findings are confirmed by robustness tests, such as alternative proxies of air pollution and information asymmetry, and the exclusion of first‐tier cities.
Fast Rises, Slow Declines: Asymmetric Unemployment Dynamics with Matching Frictions
Authors: FERRARO DOMENICO
Published: September 2022

I argue that the textbook search‐and‐matching model cannot generate the observed cyclical asymmetry in the unemployment rate. In the United States, the unemployment rate rises quickly and abruptly at the onset of recessions and declines slowly and gradually during expansions. This pattern produces positive skewness in the distribution of unemployment rate changes, while the model generates a counterfactually negative skewness. Moreover, I show that the model's inability to replicate the cyclical asymmetry in the data stands regardless of its ability to generate realistic volatility in unemployment rate fluctuations.
Usefulness of screening for Candida auris colonisation in international patients admitted to a large university hospital
Authors: Heindel Judith , Zweigner Janine , Fuchs Frieder , Hamprecht Axel
Published: September 2022

Introduction

Candida auris is an emerging pathogen in health care‐associated infections. In contrast to many other countries with rising numbers of C. auris, only seven cases have been reported in Germany from 2015 to 2017, mostly from patients who received prior medical treatment abroad. We therefore established a mandatory screening for C. auris colonisation at our tertiary care centre for all patients who were admitted as international patients or previously hospitalised in a foreign country within the past 6 months.

Methods

Colonisation of patients was assessed using a previously established screening protocol for multidrug resistant bacteria. Since 2017, all screening samples were additionally analysed for C. auris using CHROMagar Candida (CHROMagar, Paris, France). Yeast isolates were identified using matrix‐assisted laser ionisation time‐of‐flight (MALDI TOF), except for C. albicans (identified by the typical green colour on chromogenic agar). Data were analysed retrospectively.

Results

Our study cohort included 655 patients and an overall number of 1399 samples. Fifty‐three patients were colonised with Candida species (C. albicans, n = 37; C. glabrata, n = 14; others n = 9). No case of C. auris was detected. Candida spp. were mainly detected from respiratory samples (5.4% positive) and gastrointestinal specimen (5.2%). Laboratory costs were 14,689 € and analyses resulted in 98.7 h of additional technician's work.

Conclusion

No colonisation with C. auris was detected among patients with previous hospitalisation abroad. Universal C. auris screening of patients with any contact to foreign health care does not seem to be cost‐effective in our setting and more targeted screening strategies have to be developed.
Mapping the Distribution of Melanin Concentration in Different Fitzpatrick Skin Types Using Hyperspectral Imaging Technique
Authors: Calin Mihaela Antonina , Manea Dragos , Savastru Roxana , Parasca Sorin Viorel
Published: September 2022

Measuring skin melanin concentration in order to assess skin phototype according to Fitzpatrick's classification is a constant research goal. In this study, a new approach for assessing skin melanin concentration based on hyperspectral imaging combined with an appropriate analytical model that exploits specific spectral bands to generate maps of melanin content distribution on different Fitzpatrick skin phototypes is presented. Hyperspectral images from the proximal inner side of the forearms of 51 young volunteers covering the first four classes of Fitzpatrick's phototypes were acquired using a hyperspectral imaging system. The images were analyzed using a modified Beer–Lambert law that segregates the contribution of melanin from the other constituents to the skin absorption spectrum. The performance of the model was evaluated using the coefficient of determination (r‐squared). The results revealed that the approach proposed in this study generated accurate melanin concentration distribution maps that allowed a correct classification of skin phototype. In conclusion, the proposed approach for assessing skin melanin concentration proved to be very reliable for classifying skin phototypes, and, as it provides maps that are easily read, it has the advantage of a possible extension of its applications to other research concerning skin pigmentation.
Peer‐to‐peer sharing platforms with quality differentiation: Manufacturer's strategic decision under sharing economy
Authors: Guan Huiqi , Geng Xin , Gurnani Haresh
Published: September 2022

As peer‐to‐peer sharing platforms emerge in the downstream market, upstream product manufacturers may build their exclusive sharing platform, seeking benefits from the sharing market. To study the profit and welfare implications of the emergence of sharing economy and manufacturer's platform‐building strategy, we employ a vertically differentiated duopoly setting and consider three scenarios: no‐sharing benchmark, a single third‐party platform emerged, and manufacturer‐built platform co‐existing with the third‐party platform. Formulating and solving the game in each scenario, we compare the equilibrium outcomes, including manufacturers' profits, consumer surplus and social welfare, before and after scenario transitions. For the manufacturers' profits, no matter which manufacturer builds the platform in presence of the third‐party platform, that manufacturer will be better off, whereas the opponent manufacturer may also benefit, depending on the quality differentiation perceived by consumers in the product selling market and in the sharing market. Moreover, when comparing against the no‐sharing benchmark, the manufacturers benefit from the sharing only when the quality differentiation is large enough and the production cost is not small. For the welfare implication, if the renters derive the same usage utility as the owners in the sharing market, the consumer surplus and the social welfare will always increase as the third‐party platform emerges or a manufacturer builds its platform. Otherwise, either platform could hurt the consumer surplus and the social welfare, especially when the quality differentiation is large. Our research highlights the innovative platform‐building strategy in the presence of peer‐to‐peer sharing economy and offers important insights to all market participants.
A CD8+ T cell‐related genes prognostic model for hepatocellular carcinoma patients
Authors: Chang Tanjie , Yang Liangxia , Wang Xiaojing , Lu Yanda , Yang Lu , Yang Changcheng , Cai Xingrui , Li Jingquan , Zeng Jiangzheng
Published: September 2022

Immune checkpoint blockade (ICB) therapy is a promising treatment for hepatocellular carcinoma (HCC). However, it is limited by low response rates. Tumour‐infiltrating immune cells (TIICs), specifically CD8+ T cells, in the tumour microenvironment (TME) are related to tumour immune responses and are potential predictors for immunotherapeutic and survival outcomes. Therefore, we established a new CD8+ T cell‐related genes prognostic index (CD8T‐RGPI) for evaluating immune responses and prognostic outcomes for HCC. Using the TCGA databases, we evaluated the RNA‐seq data of CD8+ T cell‐related genes with gene co‐expression network. Then, the CD8T‐RGPI model was built by combining univariate Cox regression and the least absolute shrinkage and selection operator (LASSO) Cox regression analyses. The nomogram exhibited a good prediction ability for HCC patients' prognosis in either TCGA or ICGC databases. The CD8T‐RGPI was elevated in patients with high T, M and TNM stages. Functional enrichment analyses revealed that in CD8T‐RGPI high‐risk group, tumour‐related and immunosuppressive pathways, such as focal adhesion, aerobic glycolysis, HIF1 transcription factor pathway, IL‐4 and IL‐13 signalling were significantly enriched. Moreover, for CD8T‐RGPI high‐risk HCC patients, immune tolerance and immunosurveillance escape was associated with poor therapeutic outcomes for ICB therapy. The CD8T‐RGPI low‐risk HCC patients with elevated immune infiltration levels were associated with good immunotherapeutic responses to ICB. Our findings provide prospective prognostic biomarkers and elucidate on HCC immunotherapy.
Design and Operability Challenges for Supercritical CO2 Plants: The sCO2-Flex Centrifugal Compressor Test Experience
Authors: Manuele Bigi , Valentina Bisio , Silvia Evangelisti , Marco Giancotti , Alberto Milani , Tiziano Pellegrini
Published: September 2022

Interest in supercritical carbon dioxide (sCO2) cycles has grown significantly in recent years. The peculiar properties of the fluid open unique opportunities but also poses several challenges. This article aims at narrowing the knowledge gap in operating such plants, leveraging the test experience of a full-scale 5 MW centrifugal compressor (CC) prototype designed for the sCO2-flex project (H2020 funded program, grant agreement No. 764690). The test rig replicated a complete recycle loop for the compressor. In addition to validating the compressor's performances in its design condition, a larger envelope of operation and transients was explored. The chapter describes engineering groundwork and design choices regarding: (i) transient operation such as pressurized startups and emergency shutdowns (ESDs); (ii) safety relief valves and discharge lines, with possible CO2 solidification; and (iii) vibrations due to extremely high density. For all these topics, specific challenges brought by the sCO2 are described. The most meaningful results, in excellent agreement with predictions, are shown; key learnings from the test experience are discussed. The importance of anticipating risks during the design phase is highlighted and recommendations for similar installations are given. The article concludes with hints on testing severe off-design conditions, with two-phase flow at compressor suction.
Experimental Ignition Delay Time Measurements and Chemical Kinetics Modeling of Hydrogen/Ammonia/Natural Gas Fuels
Authors: Baker Jessica B. , Rahman Ramees K. , Pierro Michael , Higgs Jacklyn , Urso Justin , Kinney Cory , Vasu Subith
Published: September 2022

In recent years, hydrogen-carrying compounds have accrued interest as an alternative to traditional fossil fuels due to their function as zero-emission fuels. As such, there is interest in investigating hydrogen-carrying compounds to improve understanding of the fuels' characteristics for use in high pressure systems. In the current study, the oxidation of ammonia/natural gas/hydrogen mixtures was carried out to study carbon monoxide (CO) formation profiles as well as the ignition delay times (IDTs) behind reflected shock waves in order to refine chemical kinetic models. Experiments were carried out in the University of Central Florida's shock tube facility by utilizing chemiluminescence to obtain OH* emission and laser absorption spectroscopy to obtain CO profiles over a temperature range between 1200 K and 1800 K with an average pressure of 2.2 atm. Experimental mixtures included both neat and combination natural gas/hydrogen with ammonia addition, with all mixtures except one having an equivalence ratio of 1. Results were then compared with the GRI 3.0 mechanism, as well as the newly developed UCF 2022 mechanism utilizing chemkin-pro software. In general, both models were able to capture the trend in auto-ignition delay times and CO time histories for natural gas and ammonia mixtures. However, for ammonia–hydrogen mixtures, GRI 3.0 failed to predict ignition delay times, whereas the UCF 2022 mechanism was able to capture the IDTs within the uncertainty limits of the experiments. A sensitivity analysis was conducted for different mixtures to understand the important reactions at the experimental conditions. Finally, a reaction pathway analysis was carried out to understand important ammonia decomposition pathways in the presence of hydrogen and natural gas.
Sustainability Improvement of Membrane Separation Process for Post-Combustion CO2 Capturing Using Multi-Objective Optimization
Authors: Asadi Javad , Kazempoor Pejman
Published: September 2022

The membrane process is a promising technology for CO2 removal and mitigation. Since the energy consumption and economy of membrane-based carbon capture systems (CCSs) are critical for their large-scale deployments, optimal design and operation of such systems are the primary aims of this study. To achieve these research goals, a numerical model based on the solution-diffusion mechanism for the multicomponent gas separation process with a hollow-fiber membrane module is developed using Aspen Custom Modeler. The model is employed to investigate the effects of important operating and design parameters. Multi-objective process optimization is then performed by linking Aspen Plus and MATLAB and using an evolutionary technique to determine the optimal operating and design conditions. Our results show that by increasing the CO2 concentration in the feed gas, the CO2 capture cost significantly decreases and CO2 removal improves, although the process energy requirement slightly increases. The best achievable tradeoffs between objective functions are generated and analyzed, which substantiate the significant potential for improving the sustainability of the process. The results show that at optimum design and operating conditions, CO2 capture cost and energy consumption of the process could be as low as 13.1 $/tCO2 and 61 MW, respectively. The results of this study provide valuable insights into membrane separation and can be used by decision-makers to achieve the optimal performance of the process for commercial development and deployment of the technology.
Efficiency and Flexibility Improvement of Amine-Based Post Combustion CO2 Capturing System (CCS) in Full and Partial Loads
Authors: Asadi Javad , Jolaoso Lateef , Kazempoor Pejman
Published: September 2022

Optimal design and operation of the CO2 captures system integrated with power plants are crucial to minimize process energy consumption and associated costs. In this paper, the conventional process of monoethanolamine (MEA)-based post-combustion CO2 capturing system is modified to reduce the process energy consumption for flexible and efficient integration to fossil-fueled power plants. Considering a flue gas stream similar to coal-fired power plants, rigorous rate-based modeling of the MEA-based CO2 capture system is performed in Aspen Plus using the electrolyte nonrandom two-liquid thermodynamic package (ENRTL-RK). Afterward, three main process modifications, including lean vapor compression, rich solvent preheating, and rich solvent splitting, are investigated in both full and partial load conditions to assess their impacts on the process efficiency and energy consumption. The results demonstrate that the lean vapor compression and the rich solvent preheating modifications significantly reduce the process energy consumption by 13.5% and 8.4%, respectively. However, the addition of extra equipment such as compressors, flash vessels, and heat exchangers increase the capital and operational costs of the capture plant. Also, rich solvent splitting, which requires minor modifications in process equipment, reduces the energy consumption by 5.4%. Moreover, it is observed that the operating conditions for CO2 capture vary significantly between partial and full load conditions, and considerable reduction in energy consumption and improvement in process flexibility can be achieved at optimal process conditions.
A Review of Passive Cooling Technology Performance Testing Methods
Authors: Young David A. , Stefanakos Elias , Goswami D. Yogi
Published: September 2022

Recent research has shown that it is possible to achieve significant cooling by radiative methods without the use of mechanical equipment that require significant amount of electrical power. These passive cooling methods rely on reflecting most of the solar radiation and emitting radiation in the “atmospheric window” wavelength ranges where the atmosphere is transparent, so that a surface exchanges radiation directly with the extremely cold outer space. This literature review noted that almost all published experimental studies on radiative cooling were conducted under different environmental conditions and methodologies, making it almost impossible to compare the results. In this paper, we present a literature review, focusing on daytime radiative cooling performance, that showed an array of testing methods and environmental conditions, leading to the research question of how these technologies would compare with the same testing standard. Slight variations in environmental conditions, setup, and instrumentation from one experiment to another can present large differences in reported performance, even for the same passive radiative cooling device. Examples of setups include non-standard insulated testing chambers, convection barriers, vacuum chambers, shading devices, and instruments like feedback heaters, pyranometers, infrared radiometers and thermocouples. The testing methods reviewed point to the need for a standard cooling potential performance measurement method for the advancement of passive radiative cooling technology.
Performance Measurement and Verification of Variable-Speed Packaged Rooftop Units
Authors: Wang Weimin , Katipamula Srinivas , Underhill Ronald
Published: September 2022

Packaged rooftop units (RTUs) are widely used in commercial buildings. Most RTUs in the field are equipped with constant-speed fans and compressors. Many efforts have been made to increase the operational efficiency of RTUs with advanced design and controls. This paper presents a field study that evaluates the cooling efficiency and energy performance of RTUs with all variable-speed components, including the supply fan, the compressor, and the condenser fan. The field evaluation was performed at two sites: a supermarket in New Smyrna Beach, FL and an office building in Fort Worth, TX. On each site, a conventional RTU with constant-speed fans and compressors was selected as the reference. A set of sensors were used to measure the dry-bulb temperature and the relative humidity for the outdoor air, the return air, the mixed air, and the supply air. The RTU total power consumption was also measured using a power transducer. These sensor measurements, together with a number of control signals were monitored at 1-minute intervals. Based on the monitored data, the energy efficiency ratios (EERs) was computed for each unit daily and over the entire monitoring period. On the Florida site, the advanced RTU had an overall EER of 10.9, which was about 31% higher than the reference unit. In contrast, on the Texas site, the advanced RTU had an overall EER of 12.2, which was about 16% higher than the reference unit. The economic analysis showed that relative to an alternative scenario that either the units were not replaced or like-to-like replacements were made, the advanced RTU could at least reduce the electricity bill by $1670/yr and $4082/yr on the two sites.
Energy and Exergy Analysis of a Developed Compound Parabolic Collector Using a Pumped Solar Water Heating System
Authors: Kashamba Kabo , Letsholo Tlhalefo P. , Masoso Okatoseng T. , Nwaigwe Kevin N.
Published: September 2022

Solar water heating systems utilize different types of collectors in heating water. Therefore, a study on energy and exergy analysis of a compound parabolic collector in a pumped solar water heating system is presented. The compound parabolic collector was designed using basic sizing principles and constructed using locally available materials. The materials used in the construction include aluminum for the concentrator, copper pipes for the circulation of water through the system and mild steel for the compound parabolic collector frame. A detailed description of the construction steps followed in the development of the compound parabolic collector is presented. An experimental active solar water heating system consisting of the compound parabolic collector, a storage tank and a pump was used for analysis of energy and exergy. A pyranometer and probes were placed at the experimental site to measure solar radiance and ambient temperature respectively at the intervals of ten minutes. Experiments were carried out using the solar water heating system and a net temperature rise of 22.4°C was obtained. The energy efficiency of the compound collector was 93.1% while the obtained exergy efficiency was 20.1%. The results show that the developed compound parabolic collector is very effective in solar water heating and agrees with established research.
Speed of Sound Measurement Using an Ultrasonic Motion Detector
Authors: Santosa I. E.
Published: September 2022

We propose a method to measure the speed of sound in air using a motion detector. The experiment is based on the principle of a motion detector used to measure distances. This device measures the time of flight of alternating ultrasonic waves between the observer and the target. By assuming a fixed speed of sound, the time of flight can be converted into a distance. The medium, including its temperature through which the sound travels, influences the speed of sound. A motion detector has been used to show the effect of CO2 concentration on the resulting distance measurement, and to estimate the linear change in speed of sound per degree Celsius. The distance measurement using a motion detector has to be calibrated according to the medium’s condition. The Logger Pro 3 features allow adjustment of the temperature setting and addition of an offset value to correct the motion detector reading.
A tale of two bridges and a round Earth
Authors: Lewis Clinton
Published: September 2022

Columbus concluded that Earth is round while watching a distant ship sink beneath the horizon. You too can observe the curvature of Earth on the San Francisco Bay (and other places); not only that: you can determine Earth’s radius from such observations. I present here a method to use the vertical shift between two bridges over the Bay due to Earth’s curvature as seen in a photograph, where the more distant bridge is apparently lower than the proximate one (as shown in Fig. 1). Starting with each bridge’s known dimensions and location and applying atmospheric refraction corrections and then measuring the vertical shift between the two bridges on the image allows a calculation of Earth’s radius within a surprising 1% of the accepted value.
Drawing the Light Paths at a Lens to Find Its Effective Focal Length and Principal Planes
Authors: Ma Shih-Hsin , Wu Jun-Yi , Chiang Chun-Ming
Published: September 2022

This paper proposes a simple method to design experiments for drawing the light paths at a lens to find its effective focal length and principal planes. In the designed experiments, long-exposure photography was used to record the light scattered using a moving sheet of paper, thus revealing the light path. According to the proposed experimental method, (1) the effective focal length of a lens and (2) the principal planes of a lens can be measured. Moreover, the system is easy to build, inexpensive, and can promote students’ understanding of geometric optics by providing an intuitive physical phenomenon. The work is also of pedagogic interest as it reveals a new simple experimental method to find the principal planes of a thick lens and its effective focal length.