bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Stage Wiener Process Based Remaining Useful Life Prediction for Load Cells
Authors: Lu Huanrong , Wang Chu , Li Houxin , Yan Zhipeng , Wang Peng , He Chuchao
Published: October 2024

Nowadays, sensor technology is used in a wide range of fields, and the demand for its reliability continues to increase. Accurate estimation of the remaining useful life of sensors is critical. Since the performance degradation of sensors involves multiple stages, the single-stage Wiener degradation model is difficult to accurately characterize. To resolve this issue, a multi-stage Wiener process degradation model is established. The model utilizes the cumulative sum algorithm to identify change points among stages. Then, the performance of the multi-stage Wiener model for characterizing degradation trends is validated with load cell accelerated aging test data. Furthermore, the results of experiment demonstrate that the proposed method provides a more accurate remaining useful life estimation compared to the single-stage Wiener model, and the relative error is reduced by 18.82%.
Illumination Correction and Enhancement Algorithm for Defective Powder Spreading Images in Selective Laser Sintering
Authors: Zhang Yikang , Guo Quanmin , Qian Yaxin
Published: October 2024

Based on the uneven illumination distribution and low defect contrast in the powder spreading images acquired during the selective laser sintering manufacturing process, which affects subsequent defect detection, an adaptive nonlinear illumination correction and enhancement algorithm is proposed. Local illumination correction is performed using gray valueitting curves and is combined with global gamma correction to improve correction capability in overly dark areas. A nonlinear enhancement function is constructed to boost the contrast of the image’s illumination component. Finally, a gradient-based L0 norm minimization algorithm is used to smooth non-defect areas. Experimental results show that the proposed algorithm signi icantly improves correction and enhancement, outperforming comparison algorithms overall. Compared to the original images, the coef icient of variation decreases by an average of 0.179, and the standard deviation increases by an average of 26.7%, demonstrating the effectiveness of the proposed algorithm.
An Adaptive Strong Tracking Volume Kalman Filter Algorithm
Authors: Xue Meng , Liu Baolong
Published: October 2024

Based on dental implant technology, this paper studies the position and posture tracking of surgical tools during the treatment of patients. A strong tracking adaptive volume Kalman filter (STF-ACKF) algorithm is proposed to meet the requirements of high accuracy, low time delay and strong robustness due to the complexity of the oral space and the narrow motion environment, to improve the measurement accuracy and reduce the noise interference. The adaptive module is added to the algorithm, and the real-time correction of process noise variance is realized by using MAP estimator [1-3]. The variance of the measured noise [4-5] was estimated using the variational Bayes (VB) method. Finally, the theoretical analysis and simulation results show that the mean error of STF-ACKF on X-axis, Y-axis and yaw angle is reduced by 1.17 mm, 0.76 mm and 0.62 ° respectively, the estimation accuracy and stability are improved significantly.
Fault Line Selection of Small Current Grounding System Research Based on Zero Sequence Circuit Current Phase
Authors: Wenjun Gong , Heng Wang , Ying Zhang
Published: October 2024

This paper investigates fault line selection in small current grounding systems, focusing on the zero sequence current phase characteristics. Small current grounding systems, prevalent in medium voltage distribution networks, face challenges in fault detection due to minimal fault currents during single status phase grounding faults. Traditional methods relying on manual line switching and zero sequence voltage monitoring are inefficient and can induce overvoltage. This study categorizes fault line selection techniques into three approaches: steady-state fault information, transient information, and modern signal processing technology. The analysis of zero sequence currents in non-grounded systems reveals that fault line zero sequence currents equal the sum of system capacitive currents, flowing opposite to those in non-fault lines. Additionally, transient signal analysis shows that these signals provide more robust information for fault detection. MATLAB simulations validate the theoretical models, demonstrating that zero sequence current direction and amplitude effectively identify fault lines. The results confirm the efficacy of combining steady-state and transient signal analyses for accurate fault line selection, contributing to enhanced safety and reliability in power distribution networks. This research offers practical insights and tools for engineers, improving fault management and reducing potential economic losses in small current grounding systems.
The Inter-channel Interference Cancellation Algorithm for Wireless Magnetic Induction MIMO Communication System Based on Zero-forcing Precoding
Authors: Zhang Yufang , Lu Xinhang , Ge Jiahao , Wang Peng , Chen Chen , Wang Bin , Li Xiaoyan , Xu Yuntao
Published: October 2024

The wireless magnetic induction MIMO system can enhance the data transmission rate in near-field magnetic induction communication, but it also suffers from severe inter-channel interference issues. This paper introduces precoding techniques into the wireless magnetic induction MIMO system, employing the zero-forcing precoding algorithm to eliminate interference between different channels. Firstly, leveraging the characteristic that the channel state of magnetic induction transmit-receive coils is determined solely by the physical parameters of the coils, channel estimation is performed to obtain the channel gain matrix for wireless magnetic induction communication. Subsequently, the obtained channel matrix is subjected to zero-forcing precoding to eliminate interference caused by coupling between different channels. Simulation results indicate that the data transmission rate of the wireless magnetic induction MIMO system is significantly higher after applying zero-forcing precoding compared to the rate without it. Additionally, the system’s data transmission rate decreases as the distance between the transmitting and receiving coils increases.
Core-winding of Sodium Cold Fast Reactor Based on CFD Method Numerical Study of Flow Characteristics
Authors: Liu Qi , Wang Ying , Wang Chuan’gao , Yan Qiang , Zhang Haitao , Chen Ling
Published: October 2024

Liquid metal cooled fast reactor often uses spiral winding wire as the positioning component of fuel rod bundle. Besides fixing, spiral winding has the functions of strengthening subchannel mixing and heat transfer. These characteristics have a very important impact on the internal flow temperature characteristics of the fuel assembly and the safety of the core system, so it is necessary to conduct in-depth research on the flow field distribution of the fuel rod bundle channel with wire wound, the transverse and axial flow characteristics of the edge channel and its internal channel, the flow characteristics of the circulation and eddy current, the local temperature field, and the outlet temperature distribution characteristics. In the actual research, there are some problems such as high cost, difficulty and high risk to carry out thermal hydraulic characteristic experiment directly. This paper uses CFD fine simulation technology to study 7 rod bundles with wire winding, uses Fluent meshing to partition high-quality polyhedral unstructured mesh, uses ANSYS Fluent to conduct numerical simulation, studies the influence of the presence of rod bundles with wire winding on the distribution of flow field and local temperature field, and forms a mature and reliable simulation experiment scheme. The temperature change curve and lateral mixing phenomenon obtained by CFD simulation were investigated. The outlet temperature differences of side channel, inner channel and corner channel were investigated, and the convective heat transfer characteristics between channels were investigated due to the existence of wire winding.
High-Pressure Study of Hydrogen-Bonded Energetic Material 3,5-Dimethyl-4-Nitropyrazole
Authors: Li Han , Xi Dongyang , Yan Tingting , Jiang Ran , Zhang Dandan , Xu Yifei
Published: October 2024

This article focused on 3,5-dimethyl-4-nitropyrazole (C5H7N3O2) as the subject of research for hydrogen-bonded energetic materials. It examined the characteristics and properties of this organic crystal under high pressure using a diamond anvil cell (DAC) and Raman spectroscopy. High-pressure Raman spectroscopy studies indicate that 3,5-dimethyl-4-nitropyrazole does not undergo a phase transition at pressures up to 9.9 GPa, confirming the structural stability of this compound. Analyzing the Hirshfeld surface energy, fingerprint plots, and intermolecular interactions reveals that this stability is attributed to its unique screw structure.
High-Pressure Behavior of NdF3: Structural and Photoluminescence Properties
Authors: Zhang Dandan , Yan Tingting , Qiu Lixin , Jin Yingying
Published: October 2024

This paper investigates the pressure-induced photoluminescence properties and structural phase transitions of functional material NdF3 at room temperature using diamond anvil cell (DAC), in-situ photoluminescence technology, and simulation calculations. Under hydrostatic experimental pressure and simulated pressure up to 20 GPa, the photoluminescence spectra, lattice parameters, and bond lengths of NdF3 were obtained, showing their variations with pressure. Experimental results show that a new emission line, corresponding to the 4F3/2→4I9/2 transition of Nd3+ ions, appears around 12 GPa and persists up to the highest pressure of the experiment. Upon decompression, the new emission line disappears, indicating a reversible phase transition. Notably, from 0 to 12 GPa, the emission intensity of NdF3 decreases significantly under pressure, which may be attributed to the increased energy of lattice phonons in the compressed crystal (shorter Nd-F bonds), leading to enhanced phonon-assisted non-radiative relaxation.
Preparation, Modification and Property Characterization of Nano-TiO2
Authors: Wang Xiaodan , Fan Zhaorong , Liu Yang
Published: October 2024

In view of the strong polarity and easy agglomeration of nano TiO2 in practical applications, its excellent performance cannot be fully exerted. In this paper, nano titanium dioxide was prepared by liquid phase hydrolysis method using TiCl4 and oxalic acid as raw materials, and then the surface modification of nano TiO2 was carried out with sodium dodecylbenzenesulfonate(SDS). The optimal modification process conditions were obtained through single-factor experiment and orthogonal experiment. The products before and after modification were characterized by scanning electron microscopy, infrared spectroscopy, particle size analysis. The results indicated that the modified nano titanium dioxide adsorbed a certain amount of modifier on the surface, with small and uniform particles that are not easily agglomerated. This greatly improved its dispersibility and stability in media, providing better guarantee for its application in various fields.
A Novel Microwave Dielectric Ceramic LiSrVO4 for LTCC
Authors: Cheng Zelai , Wang Xi , Su Hua
Published: October 2024

LiSrVO4 (LSV) ceramics were prepared using the solid-state synthesis method, and their phase structure, morphology, sintering characteristics, and microwave dielectric properties were investigated. The LSV ceramics could be densified by sintering at 875–925 °C for 4 hours. XRD indicated that LSV ceramics sintered at 875–925 °C for 4 hours were singlephase ceramics with a monoclinic structure. With the increase in sintering temperature, the dielectric constant and quality factor of LSV ceramics first increased and then decreased, while the temperature coefficient of the resonant frequency gradually decreased. LSV ceramics sintered at 900 °C for 4 hours exhibited a εr
of 10.92, a Q×f value of 21115 GHz, and a τf
of -4 ppm/°C. LSV ceramics demonstrated good chemical compatibility with silver, showing promising potential in the field of Low-Temperature Co-fired Ceramics.
Reproductive Performance of Beef Cattle (SIMPO, LIMPO, and Angus Grade-Black) and Socio-Economic Profile of Farmers in Sragen Regency, Indonesia
Authors: Riyanto J , Pramono A , Yanti Y , Cahyadi M , Wati A K , Pawestri W , Ananda R , Adinata Y , Krishna N H
Published: October 2024

This research aimed to obtain information regarding reproductive performance of three types of beef cattle in smallholder farm in Sragen Regency, Indonesia. Data was collected using survey with purposive sampling technique. The cattle samples included SIMPO, LIMPO, and Angus grade-black cattle. In addition, this research focused on some main reproductive performance indicators, namely postpartum estrus (PPE), postpartum mating (PPM), days open (DO), service per conception (S/C), and calving interval (CI). Following this process, farmers’ characteristics considered included age, highest level of education attained, length of farming experience, and daily income. All these characteristics were used as a support system to help achieve optimal productive performance of animals. Among the three types of cattle studied, Angus grade-black had better DO, S/C, and CI compared to SIMPO and LIMPO. This signified that Angus grade-black was more adaptive to tropical conditions of Sragen.
Commercial Trade and Conservation: DNA Barcoding of Wild Reticulated Python (Malayopython reticulatus) (Schneider, 1801) for Sustainable Management
Authors: Haris Hidayah , Ngadi Ehwan
Published: October 2024

The reticulated python, scientifically known as Malayopython reticulatus, is a prominent member of the Pythonidae family, exhibiting a wide geographic distribution across Southeast Asia. Like most python species, it is listed on Appendix II of CITES, allowing for regulated harvest and commercial export. However, inadequate monitoring of snakeskin origins within Malaysia has facilitated illegal trade, exacerbating concerns over population declines. Thus, this study aims to document the DNA barcoding of M. reticulatus in Pantai Penyabong, Johor, utilizing the COI gene marker of mitochondrial DNA (mtDNA). Observations revealed 11 reticulated pythons, with two successfully captured for blood sample extraction and amplification. Sequences obtained exhibited a high identity percentage in the NCBI GenBank database, supported by similar topologies in phylogenetic trees. These findings demonstrate the efficacy of molecular identification techniques in combating illegal wildlife trade. Governments and law enforcement agencies can enforce conservation laws and protect wild populations by verifying mislabeled python species. This study highlights the crucial role of DNA barcoding in wildlife forensics and conservation management, offering a rapid and reliable method for species identification and monitoring in the face of escalating threats.
Ramsey interferometry of nuclear spins in diamond using stimulated Raman adiabatic passage
Authors: Lourette Sean , Jarmola Andrey , Chathanathil Jabir , Carrasco Sebastián C , Budker Dmitry , Malinovskaya Svetlana A , Birdwell A Glen , Ivanov Tony G , Malinovsky Vladimir S
Published: October 2024

We report the first experimental demonstration of stimulated Raman adiabatic passage (STIRAP) in nuclear-spin transitions of 14N within nitrogen-vacancy color centers in diamond. It is shown that the STIRAP technique suppresses the occupation of the intermediate state, which is a crucial factor for improvements in quantum sensing technology. Building on that advantage, we develop and implement a generalized version of the Ramsey interferometric scheme, employing half-STIRAP pulses to perform the necessary quantum-state manipulation with high fidelity. The enhanced robustness of the STIRAP-based Ramsey scheme to variations in the pulse parameters is experimentally demonstrated, showing good agreement with theoretical predictions. Our results pave the way for improving the long-term stability of diamond-based sensors, such as gyroscopes and frequency standards.
Spatio-temporal trends in the frost regime reveal late frost exposure to white spruce (Picea glauca [Moench] Voss) persists in northeastern America
Authors: Marquis Benjamin , Lamara Mebarek , Roy Alexandre , Rossi Sergio , Bergeron Yves , Godbout Julie , Aubin Isabelle , Perron Martin
Published: October 2024

The characteristics of the frost regime (intensity, frequency, and timing) contribute to shaping tree species adaptations and distribution as well as ecosystem productivity and functions. However, climate change increases the variability in extreme events; therefore, the different characteristics of the frost regime may diverge under climate change. Using the BioSim 11 software, we simulated daily air temperature at 512 locations over northeastern North America between 1901–2021 to determine how the spatio-temporal trends in the frost regime varied over this complex landscape and if spatio-temporal trends in extreme climatic events such as frosts are stronger compared to changes in aggregated climate variables such as mean annual air temperature and growing degree-days. We also used an eco-physiological model to conduct a case study focussing on white spruce to determine if trees are currently more exposed to growing season frosts than they were in the past by modelling the timings of budburst using the thermal time model. Our results showed that, at 67% of locations (343 locations), the day of the year of the last frost in spring (minimum daily air temperature<0 °C) occurred, on average, earlier by seven days during 2001–2021 compared to 1901–1920, whereas it occurred, on average, later by four days at 33% of locations (169 locations). The average temporal trends in frost occurrence were similar in magnitude to the average trends in aggregated climate variables; however, their variances were larger compared to the aggregated climate metrics, showing that the frost regime does not change uniformly throughout our study area. Our case study also revealed that white spruce remains exposed to late frosts of low and intermediate intensities (minimum daily air temperature <0; <−2 °C) compared to the past but exposure to high-intensity frosts (minimum daily air temperature <−4 °C) is rare. Since extreme events such as late frosts diverge in their response to climate change compared to aggregated climate variables, the mean annual temperature is not sufficient to predict how climate change will impact ecosystems through frost regimes.
Geometry
Authors: Danesi Marcel
Published: October 2024

Requiring a blend of logic and spatial imagination, Alcuin’s six problems in geometry—numbers 21, 22, 23, 24, 25, and 26 in the Propositiones—put on display what mathematical thinking involves in its essence. This chapter looks at these problems in the light of the kinds of notions and methods they entail, and the type of thinking processes required to solve them. It also discusses the importance of notions such as the Pythagorean theorem, figurate numbers, and triangular numbers. It looks as well at the nature of proof, illustrated by a well-known early proof for π in the Egyptian Rhind Papyrus, and at the implications of Fermat’s Last Theorem. The geometrical problems in Alcuin’s text would have been truly challenging for his medieval readers, some of which require “outside-the-box” thinking, as it is called today. In Alcuin’s era, geometry was seen to constitute the starting point for a theoretical study of mathematics, since it involved mastering the methods of proof established by Euclid and other ancient mathematicians.
Algebra
Authors: Danesi Marcel
Published: October 2024

Among Alcuin’s 53 problems in his Propositiones there are a series of “story problems,” as they are called today—numbers 2, 3, 4, 7, 16, 36, 37, 40, 44, 45, and 48—involving basic algebraic thinking. The problems are solved nowadays by setting up an equation or system of equations; but in Alcuin’s era, there was no formal algebra as such. These problems nevertheless put on display what algebra is essentially all about—thinking about problems in abstract ways, rather than concretely in arithmetical ways. This chapter deals with Alcuin’s story problems, examining a few other famous ones, such as the well-known story problem devised by Sir Isaac Newton. It also schematically discusses the Fundamental Theorem of Algebra and its basis in complex numbers. Alcuin’s inclusion of algebraic problems in his text showed to his medieval readers that the topic of equations was not the daunting one that his readers might have thought it was. The main difference between carrying out an operation arithmetically and doing so algebraically lies in thinking about the operation in general rather than in specific numerical terms.
Diophantine Problems
Authors: Danesi Marcel
Published: October 2024

Solving Diophantine problems involves considering fewer equations than unknowns. The challenge is to figure out the whole numbers that solve all equations simultaneously. There are seven such problems in Alcuin’s Propositiones—numbers 5, 32, 33, 34, 38, 39, and 47. This chapter deals with these problems and the kind of mathematical thinking that they encompass, as well as the kinds of implications they have had for methods of solving equations, including quadratic equations, and for grasping the nature of functions. It is not known if Alcuin had read Diophantus’s Arithmetica, from where such problems originate, but it is clear that he understood the implications that they had for acquiring mathematical skills. Solving Diophantine problems requires acumen and persistence. Alcuin likely included them in his text to challenge his students to think outside the box, thus emphasizing that mathematics requires not only logical thinking but also a large amount of imagination.
Measurement
Authors: Danesi Marcel
Published: October 2024

Seven of the problems in Alcuin’s Propositiones involve measurement—numbers 8, 9, 10, 12, 30, 31, and 51. This chapter deals with these problems and their implications. Using mathematics to generalize practical measurement problems has always been a central part of the applications of the discipline. However, there is one problem, number 51, involving pouring liquid from one container to another, that appears for the first time in Alcuin’s text. As such, it became, thereafter, a staple of recreational mathematics. Two famous descendants discussed in this chapter are the ones by Nicolas Chuquet and Lewis Carroll. The general implications of Alcuin’s Problem 12, moreover, have been examined by various mathematicians, since it bears within it a particular sequence structure, now known as “Alcuin’s Sequence.”
Luther’s “German Hour”
Authors: Hayden-Roy Patrick
Published: October 2024

The German Protestant church greeted the ascension of Hitler to the position of Chancellor in January 1933 and the seizure of authority that ensued with broad acclamation. In this environment, Protestant authors deployed Luther to affirm the “positive Christianity” of the new regime. Though the year would be full of complexities in terms of the church’s relationship to the new order, Luther was for the most part represented as embracing the new völkisch German state, and providing justification for the dismantling of German democracy and the introduction of an authoritarian system of rule. The chapter considers, in particular, the four-hundred-fiftieth anniversary celebrations of Luther’s birth, and the fulsome rhetorical celebrations of Hitler and the new regime by Paul Althaus and others that were part of the outpouring of literature, addresses, and public ceremonies. It examines as well the dissent that emerged in some quarters of the church, in particular from Dietrich Bonhoeffer, Karl Barth, and the emerging Confessional Church movement, who also drew upon Luther to articulate a critique of the new regime’s racial nationalist cultural politics.
Luther [and] der Führer
Authors: Hayden-Roy Patrick
Published: October 2024

Chapter 6 portrays the many ways in which Luther was framed in comparison with Hitler, and how this pairing of the two provided a seemingly providential legitimacy for Hitler’s cult of rulership. In this literature, both Luther and Hitler are styled as Führer of the German Volk, each seen to affirm the other’s status as divinely authorized leaders, suggesting the symbiosis between Luther’s ideal of faith and Hitler’s ideal of political and social revival. The chapter highlights how this pairing of the two figures came not from the regime, but from authors within the mainstream of the church and academia, suggesting how much the church’s relationship with the regime was driven by the desire to affirm the regime’s purposes, and, in so doing, providing evidence of Protestant Christianity’s elective affinity with their leader and his movement.
Education, health-based selection, and the widening mortality gap between Americans with and without a four-year college degree
Authors: Case Anne , Deaton Angus
Published: October 2024

Background: Gaps in life expectancy between Americans with and without a college degree have widened markedly over the past three decades. One explanation points to increasing educational attainment changing the type of people with and without a degree. If pre-existing health in the two education groups changes as the fraction with a degree changes, health selection might explain the widening mortality gap. Methods: We examine this explanation using (a) education and mortality in each birth cohort of men and women from 1940 to 1988, and (b) the natural experiment caused by the Vietnam War, which increased the fractions of men with a degree in affected birth cohorts. For each cohort, we examine the relationship between the mortality gap and the fraction with a degree. Results: We find no relationship between the fraction of a birth cohort with a degree and the corresponding mortality gap. For men, the large increase in college going spurred by Vietnam has no perceptible counterpart in the mortality gap. Conclusion: The evidence from the natural experiment induced by the Vietnam War does not support a health-selection explanation for the widening mortality gap.
Addressing bias due to measurement error of an outcome with unknown sensitivity in database epidemiological studies
Authors: Limoncella Giorgio , Grilli Leonardo , Dreassi Emanuela , Rampichini Carla , Platt Robert , Gini Rosa
Published: October 2024

In epidemiological database studies, the occurrence of an event is measured with error through an indicator whose specificity is often maximised, at the expense of sensitivity. However, if the indicator has low sensitivity, measures of occurrence are underestimated. In association studies, risk difference is biased, and risk ratio may be biased as well, in either direction, if the sensitivity is differential across exposure groups. In this work, we show that if an auxiliary screening indicator can be defined to complement the main indicator, estimates of the positive predictive value of both indicators provide tools to estimate the sensitivity of the primary indicator, or a lower bound thereof. This mitigates bias in estimating the number of cases, prevalence, cumulative incidence, rate (particularly when the event is rare), and in association studies, risk ratio and risk difference. They also allow testing for non-differential sensitivity. While direct estimation of sensitivity is often infeasible, this novel methodology improves evidence based on data obtained from re-use of existing databases, which may prove critical for regulatory and public health decisions.
Nonsurgical Medical Aesthetics and Patient Quality of Life: An Umbrella Review
Authors: Hemsworth Barbara , Hemsworth Cody , Richmond Sarah A
Published: October 2024

Nonsurgical cosmetic facial procedures have become popular treatment options for individuals seeking aesthetic improvements. Despite a breadth of literature on patient satisfaction with treatment outcomes, there is a lack of information specific to changes in quality of life outcomes. The objective of this umbrella review is to report the effectiveness of nonsurgical facial aesthetic treatments on reported quality of life in cosmetic treatment–seeking patients. The authors also aim to identify gaps in the literature on measures of quality of life outside of patient satisfaction. The authors completed a comprehensive, systematic search of review articles across 6 databases, including Medline, CINAHL Plus, EMBASE, APA PsycINFO, Cochrane Reviews, and Google Scholar. They included review-level studies that examine the changes in quality of life measures following treatment. A critical appraisal was completed for each review article included. A total of 7 reviews were included. One review was of strong quality, 2 moderate, and 4 were weak. Several nonsurgical procedures were evaluated across reviews, including injectable neurotoxins, dermal fillers, and laser skin resurfacing. The majority of included studies reported increases in measures of quality of life, posttreatment in the same patient or compared with controls. The most commonly reported measure was psychological well-being, followed by self-perception. There was a lack of measures outside of improvements to aesthetics, including those specific to mental health (eg, depression). Overall, based on the studies on nonsurgical treatments, the authors report increases in overall quality of life. This conclusion should be interpreted with caution, as the majority of reviews included were of moderate-to-weak quality. A major gap in this literature includes mental health outcomes. Future research should focus on increasing the rigor of reporting for systematic reviews.

Level of Evidence: 2 (Risk)
Comment on ‘Patient-initiated follow-up for high-risk cutaneous squamous cell carcinoma: how we do it and 2 years of outcome data’
Authors: Ding Delaney D
Published: October 2024

I read with great interest the report by Abdul Gafoor et al. on patient-initiated follow-up for high-risk cutaneous squamous cell carcinoma. However, several considerations warrant further exploration.
An updated systematic review of the risk factors for unplanned dialysis initiation
Authors: Magadi Winnie , Birnie Kate , Santhakumaran Shalini , Caskey Fergus J , Ben-Shlomo Yoav
Published: October 2024

Background

Previously, a comprehensive review of the risk factors for unplanned dialysis initiation (UDI) was conducted by Hassan et al. (2019), based on studies published up to the end of 2017. They demonstrated that high-quality data and well-designed studies on the subject are lacking. Thus we updated their review to establish the modifiable factors associated with UDI.

Methods

MEDLINE and Embase were searched from January 2018 to August 2023. Following several rounds of screening, we identified 17 international studies (the majority of which were based in Europe) that met the eligibility criteria.

Results

Many of the included studies were well designed, utilised large datasets and adopted properly adjusted analyses to examine associations between patient characteristics and UDI. Definitions of UDI varied across studies, i.e. timeliness of presentation, vascular access type, initiating dialysis as an inpatient/outpatient or for life-threatening indications. The most common risk factors reported were cardiovascular disease, older age, lower body mass index, cause of kidney disease, cancer, diabetes, lower serum albumin, faster decline in kidney function and fewer number of nephrology visits prior to dialysis start. These were in line with those reported by Hassan et al., however, our updated review revealed several other important predictors of UDI, e.g. worse coding of chronic kidney disease in the general practitioner health record, lower health literacy and having acute kidney injury.

Conclusions

Our review provides new insights into reasons why people start dialysis in an unplanned manner, many of which are modifiable, thus contributing to efforts in reducing the rate of UDI.
Initiating systemic capacity development for leadership from the bottom-up: a realist evaluation of a leadership innovation in a South African health district
Authors: Orgill Marsha , Marchal Bruno , Harris Bronwyn , Gilson Lucy
Published: October 2024

The need for leadership within district health systems is critical for the effective delivery of services and for inter-sectoral collaboration for health. Leadership capacity development (LCD) has not, however, been prioritized within health systems, and the systemic capacity (i.e. roles, structures and processes) that is needed to develop managers who can lead is not always in place. This paper aims to contribute to understanding how to build such capacity, considering a relevant bottom-up innovation. We observed, in the period 2013–15, the emergent implementation of this innovation (a ‘Leadership Commission’) in a South African health district. What started out as an effort to train individual leaders evolved into the development of systemic capacity for LCD. We adopted realist evaluation as the main methodological approach, as well as case study design, and we first developed a programme theory of the internally driven LCD initiative, through a round of interviews with senior managers. We then tested the programme theory drawing on 14 in-depth interviews and field notes of meetings and processes. Our analysis suggests that building systemic capacity for LCD requires leadership to be expressed as a strategic priority by those with positional authority and that bottom-up LCD requires institutional commitment through strengthening routine structures or creating new ones. The ability to leverage existing resources is another key element of systemic capacity. The mechanisms that enable bottom-up capacity development include tacit and experiential knowledge, sensemaking, systems thinking and trust between, and motivation of, those tasked with leading LCD. Leadership development is constrained by increased workloads for those involved as the prioritization of leadership becomes simply an additional task, and sustainability challenges are likely in the absence of additional resources for bottom-up innovation.
Clinical outcomes and the impact of treatment modalities in children with carbapenem-resistant Enterobacteriaceae bloodstream infections: a retrospective cohort study from a tertiary university hospital
Authors: Avcu Gulhadiye , Erci Ece , Bilen Nimet Melis , Ersayoglu Irem , Ozek Gulcihan , Celtik Ulgen , Terek Demet , Cilli Feriha , Bal Zumrut Sahbudak
Published: October 2024

Background

The increasing prevalence of carbapenem-resistant Enterobacteriaceae (CRE) infections among children represents a significant global concern, leading to elevated mortality rates. The aim of this study was to evaluate the risk factors, outcomes, 30-day mortality rates and contributing factors in children with CRE bloodstream infections (CRE-BSIs).

Methods

Data regarding demographic characteristics, treatment approaches and outcomes of hospitalized children aged 0–18 years diagnosed with CRE-BSIs between January 2018 and December 2022 were extracted from medical records. Mortality within 30 days of diagnosis and the predictive factors were analysed.

Results

A total of 114 children, with a median age of 11 months (range: 6–69.5), were included. All cases of CRE-BSIs were either healthcare associated or hospital acquired and presented with at least one underlying comorbidity. A previous history of CRE colonization or infection rate was 48.2% (55/114). Klebsiella pneumoniae 87.7% (100/114) was the most frequently isolated microorganism, with a 30-day mortality rate of 14% (16/114). Multivariate analysis identified paediatric intensive care unit admission, invasive mechanical ventilation, inotropic support and thrombocytopenia due to CRE-BSIs as the most discriminative predictors for 30-day mortality (P < 0.001). Central venous catheter (CVC) removal was associated with a reduced mortality rate (P = 0.012). High-dose prolonged infusion of MEM-based or polymyxin-based antibiotic combinations did not impact survival. Lower MEM MIC values were associated with improved survival.

Conclusions

The mortality rate of CRE-BSI is notably high in childhood. The use of antibiotic combination strategies did not demonstrate a significant impact on 30-day survival; however, the removal of CVCs was found to lower mortality rates.
Establishment of a diverse pheno-genotypic challenge set of Klebsiella pneumoniae and Pseudomonas aeruginosa suitable for use in the murine pneumonia model
Authors: Fratoni Andrew J , Padgett Alissa M , Duffy Erin M , Nicolau David P
Published: October 2024

Background

Preclinical murine infection models lack inter-laboratory uniformity, complicating result comparisons and data reproducibility. The European Innovative Medicines initiative-funded consortium (COMBINE) has developed a standardized murine neutropenic pneumonia protocol to address these concerns. While model methods have been standardized, a major obstacle to consistent results is the lack of available bacteria with defined viability and variability. Herein, we establish a diverse challenge set of Klebsiella pneumoniae and Pseudomonas aeruginosa suitable for use in the COMBINE protocol to further minimize experimental inconsistency and improve the interpretability of data generated among differing laboratories.

Materials and methods

Sixty-six K. pneumoniae and 65 P. aeruginosa were phenotypically profiled against tigecycline (K. pneumoniae only), levofloxacin, meropenem, cefiderocol and tobramycin. Fifty-nine isolates were introduced into the COMBINE model to assess the sufficiency of the starting bacterial inoculation, resultant baseline bacterial burden, achievement of ≥1 log10cfu/lung growth at 24 h, time to and percentage mortality. Forty-five isolates displaying desirable minimum inhibitory concentration profiles were subjected to replicate in vivo testing to assess target parameters.

Results

83% of K. pneumoniae reached the prerequisite growth at 24 h using a starting bacterial burden ≥7 log10cfu/lung. P. aeruginosa isolates grew well in the model: 90% achieved the growth target with a starting bacterial burden of 6 log10cfu/lung. Mortality was negligible for K. pneumoniae but high for P. aeruginosa. Poor or inconsistent achievement of the 24 h growth target was seen in 11/59 isolates.

Conclusions

With this diverse cache of viable isolates established in the COMBINE pneumonia model, future translational studies can be undertaken to set efficacy benchmarks among laboratories.
Elizabethkingia bloodstream infections in severely immunocompromised patients: persistent, relapsing and associated with high mortality
Authors: Fahmy Mark , Stewart Adam , Tey Siok-Keen , Hajkowicz Krispin
Published: October 2024

Objectives

Elizabethkingia species are uncommon causes of bloodstream infections, representing a true opportunistic and multi-drug-resistant pathogen to immunocompromised or vulnerable hosts. Despite this, data are lacking regarding optimal management strategy for infections with this organism, which is associated with significant mortality and morbidity. We describe patient characteristics, management and outcomes in this case series.

Patients and methods

All inpatients at the Royal Brisbane and Women’s Hospital with a positive blood culture for Elizabethkingia spp. were identified by database query. Clinical information including medical history, source of infection, attempts at source control and outcome were collected. Laboratory data including duration of bacteraemia and antimicrobial susceptibility testing were also collected.

Results

All patients had severe defects of innate and adaptive immunity. Targeted therapy was started promptly and efforts at source identification and control were appropriately pursued. Despite this, outcomes were generally poor. A previously unrecognized presentation of relapsing infection was described in one case, requiring long-term suppressive antimicrobials to control. One case died as a result of infection and one case was cured, but died soon after due to complications of immunosuppression.

Conclusions

Treatment of these organisms is challenging due to limited effective therapy, development of on treatment resistance and profound host immunocompromise. Up-front use of multiple, optimally dosed antimicrobials, attempting source control and attempting to restore host immune function all appear to be key to achieving good outcomes.
Enhanced d-pantothenic acid biosynthesis by plasmid-free Escherichia coli through sodium pyruvate addition combined with glucose and temperature control strategy
Authors: Zhou Hai-Yan , Peng Jin-Bang , Chen Yi-Hong , Yang Zi-Jian , Liu Zhi-Qiang , Zheng Yu-Guo
Published: October 2024

Aims

d-pantothenic acid (d-PA) is an important vitamin widely used in the feed, pharmaceutical, and food industries. This study aims to enhance the d-PA production of a recombinant Escherichia coli without plasmid and inducer induction.

Methods and results

The fermentation medium in shake flask was optimized, resulting in a 39.50% increased d-PA titer (3.32 g l−1). Subsequently, the fed-batch fermentation in a 5-l fermenter was specifically investigated. First, a two-stage temperature control strategy led to a d-PA titer of 52.09 g l−1. Additionally, a two-stage glucose feeding was proposed and d-PA titer was increased to 65.29 g l−1. It was also found that an appropriate amount of sodium pyruvate was beneficial to cell growth and d-PA synthesis. Finally, a two-stage glucose feeding combined with sodium pyruvate addition resulted in a substantially improved d-PA production with a titer of 72.90 g l−1.

Conclusion

The d-PA synthesis was significantly improved through the fermentation process established in this work, i.e. sodium pyruvate addition combined with the temperature and glucose control strategy. The results of this study could provide significant reference for the industrial fermentation production of d-PA.
Cancer chemotherapy in pregnancy and adverse pediatric outcomes: a population-based cohort study
Authors: Metcalfe Amy , Cairncross Zoe F , McMorris Carly A , Friedenreich Christine M , Nelson Gregg , Bhatti Parveen , Fell Deshayne B , Lisonkova Sarka , Sikdar Khokan C , Shack Lorraine , Ray Joel G
Published: October 2024

Background

Administration of chemotherapy during pregnancy is often delayed, while preterm delivery is common. If in utero exposure to chemotherapy is associated with adverse pediatric outcomes, it is unknown whether that relationship is directly attributable to the chemotherapy or is mediated by preterm birth.

Methods

Patients were identified from Canadian cancer registries and administrative data in Alberta, British Columbia, and Ontario, 2003-2017, with follow-up until 2018. The primary exposure was receipt of chemotherapy during pregnancy. Severe neonatal morbidity and mortality (SNM-M), neurodevelopmental disorders and disabilities (NDDs), and pediatric complex chronic conditions (PCCC) reflected short- and long-term pediatric outcomes. Modified Poisson and Cox proportional hazard regression models generated adjusted risk ratios (RR) and hazard ratios (HR), respectively. The influence of preterm birth on the association between exposure to chemotherapy in pregnancy and each study outcome was explored using mediation analysis.

Results

Of the 1150 incident cases of cancer during pregnancy, 142 (12.3%) received chemotherapy during pregnancy. Exposure to chemotherapy in pregnancy was associated with a higher risk of SNM-M (RR = 1.67, 95% confidence interval [CI] = 1.13 to 2.46), but not NDD (HR = 0.93, 95% CI = 0.71 to 1.22) or PCCC (HR = 0.96, 95% CI = 0.80 to 1.16). Preterm birth less than 34 and less than 37 weeks mediated 75.8% and 100% of the observed association between chemotherapy and SNM-M, respectively.

Conclusions

Most children born to people with cancer during pregnancy appear to have favorable long-term outcomes, even after exposure to chemotherapy in pregnancy. However, preterm birth is quite common and may contribute to increased rates of adverse neonatal outcomes.
GABA transport: beyond stress? A closer look at AtGAT2
Authors: Tayengwa Reuben
Published: October 2024

This article comments on:

Meier S, Bautzmann R, Komarova NY, Ernst V, Suter Grotemeyer M, Schröder K, Haindrich AC, Vega Fernández A, Robert CAM, Ward JM, Rentsch D. 2024. Stress-regulated Arabidopsis GAT2 is a low affinity γ-aminobutyric acid transporter. Journal of Experimental Botany 75, 6295–6311 https://doi.org/10.1093/jxb/erae321
Geraniol inhibits both planktonic cells and biofilms of the Candida parapsilosis species complex: Highlight for the improved efficacy of amphotericin B, caspofungin and fluconazole plus Geraniol
Authors: Sidrim José Júlio Costa , Martins Daniel Vieira , da Rocha Maria Gleiciane , Araújo Géssica dos Santos , Cordeiro Rossana de Aguiar , Guedes Glaucia Morgana de Melo , Pereira-Neto Waldemiro de Aquino , Castelo-Branco Débora de Souza Collares Maia , Rocha Marcos Fábio Gadelha
Published: October 2024

The Candida parapsilosis species complex poses a recognized threat to the nosocomial environment. In the scenario of the global rise of resistant strains to antifungals, geraniol, a terpene isolated from different essential oils, has shown promising antimicrobial activity. We evaluated: (1) the effects of geraniol against the C. parapsilosis species complex, in planktonic and biofilm forms; (2) the strains’ susceptibility to clinical antifungals and (3) the geraniol interaction with antifungals. Eighteen isolates were subjected to in vitro susceptibility testing by the broth microdilution protocol, using geraniol, amphotericin B, caspofungin, itraconazole and fluconazole to determine the minimum inhibitory concentration (MIC) and subsequently, we measured the fungicidal activity. Geraniol was tested against biofilms by the measurement of the metabolic activity and biomass. Pharmacological interactions were performed by the checkerboard method. Geraniol's MIC range was between 256 and 512 µg/ml. MIC range for clinical antifungals was ≤ 0.031–4 µg/ml. Geraniol also showed antibiofilm activity with average reductions of metabolic activity (38.33%) and biomass (30.69%), at MIC concentration. Furthermore, geraniol showed synergistic/additive effects with antifungals. Briefly, geraniol inhibits both planktonic cells and biofilms of the C. parapsilosis species complex and besides it improves the efficacy of amphotericin B, caspofungin and fluconazole.