bluuebunny/crossref_metadata_2025 huggingface dataset:
Tetraarylphosphonium Cations with Excellent Alkaline‐Resistant Performance for Anion‐Exchange Membranes
Authors: Hifumi Ryoyu , Toyama Yoshikazu , Ikeda Keisuke , Hashimoto Tetsuaki , Imai Tomohiro , Inagi Shinsuke , Tomita Ikuyoshi
Published: December 2024

To realize the robust anion exchange membrane (AEM)‐based water splitting modules and fuel cells, the design and synthesis of tetraarylphosphonium (TAP) cations are described as a new class of cationic building blocks that exhibit remarkable alkaline stability under harsh conditions. TAP cations with highly sterically demanding aromatic substituents were efficiently synthesized from triarylphosphine derivatives and highly reactive arynes, whose alkaline degradation proved to be suppressed dramatically by the sterically demanding substituents. In the case of bis(2,5‐dimethylphenyl)bis(2,4,6‐trimethylphenyl)phosphonium, for example, approximately 60% of the cation survived for 27 d under the forced conditions (i.e., in 4 M KOH/CD3OH at 80 °C), while tetraphenylphosphonium degraded completely within 10 min in 1 M KOH/CD3OH at that temperature. Through the decomposition of the alkaline‐stable TAP cations, not only triarylphosphine oxides, which are often reported to form via the nucleophilic attack toward the cationic phosphorus center, but also triarylphosphines were detected, which suggested the presence of other degradation mechanisms due to the sterically demanding aromatic substituents. In kinetic analyses, bis(2,5‐dimethylphenyl)bis(2,4,6‐trimethylphenyl)phosphonium was found to exhibit 52 times higher stability compared to benzyltrimethylammonium, which is often employed as the cationic building block for AEMs.
Virtual Synchronous Machine Based Direct Charging Power Control for the Two‐Stage EV Battery Charger
Authors: Cai Jun , Cheok Adrian David , Yan Ying , Zhang Xin
Published: December 2024

In this paper, a direct charging power control strategy (DCPC) based on virtual synchronous machine (VSM) technique is proposed for the two‐stage EV battery charger. In the proposed solution, the two‐stage charger involves a three‐phase full bridge‐based AC‐DC stage and a buck/boost DC‐DC stage. In control of the front‐end AC‐DC stage, the core algorithm of the traditional VSM is adopted. Nevertheless, unlike the traditional VSM‐based battery charging scheme, the DC‐bus closed‐loop in the traditional VSM algorithm is replaced by a positive feedback‐based DC power compensation loop, and meanwhile, the DC‐bus voltage is regulated by the rear stage DC‐DC converter. The proposed method can ensure stable DC‐bus voltage control and direct control of charging power. Due to the existence of power compensation control, the power balance between AC and DC terminals can be indirectly controlled without complex power losses calculation process. In addition, the autonomous AC frequency and voltage regulation abilities of the VSM technique can be inherited in the proposed method, which can appear a grid‐friendly charging pattern to ensure more stable battery charging. To verify the validity of the proposed method, systematic analysis and experiments are performed on a developed test bed.
Resistance Theory of Asymmetric 2 × n Circuit Network
Authors: Zhang Zhi‐Li , Tan Zhi‐Zhong
Published: December 2024

This article proposes a class of asymmetric 2 × n resistor network model which contains multiple independent resistors; the study of asymmetric resistor network models is a challenge. We conducted in‐depth research on this issue using the RT‐V theory (Chinese Physics B, 2017, 26(9): 090503) and achieved new theoretical breakthroughs. This paper derived five original equivalent resistance formulae for this asymmetric 2 × n circuit network and also discusses the analytical expressions for equivalent resistance in different special cases, and several interesting results have been derived, indicating that the original resistance formula has powerful functionality. Finally, visual graphics of two types of equivalent resistances are provided using MATLAB drawing tools, which reveals the law of equivalent resistance changing with resistance variables. The research theory and technology in this article will provide a new theoretical basis for related scientific, engineering, and simulation research.
Empowering Rural Farming: Agrovoltaic Applications for Sustainable Agriculture
Authors: Singla Manish Kumar , Gupta Jyoti , Gupta Anupma , Safaraliev Murodbek , Zeinoddini‐Meymand Hamed , Kumar Ramesh
Published: December 2024

Agrovoltaics, also known as Agri‐PV or AV, is an innovative approach that entails the shared utilization of land for both the production of agricultural commodities and energy generation. This concept has gained immense popularity in recent times owing to its ability to boost income per unit of land area significantly. The scope of AV systems is quite extensive, as it encompasses solar energy converters and other renewable energy sources like bioenergy. Current strategies for agrovoltaic (AV) in agriculture are the outcome of the gradual development of agroecology and the integration of photovoltaic (PV) power supply into the grid. These approaches could lead to a nearly doubled income per unit area. Without on‐site power supply, reduced chemical fertilizers and pesticides, and on‐site yield processing, AV has the potential to revolutionize large‐scale unmanned precision agriculture and smart farming. These approaches might lead to significant changes in the logistics and value‐added production chain, thereby reducing agriculture's carbon footprint. In the future, it is possible to reduce the cost of AV technology by half by utilizing decommissioned solar panels in the technology and to delay the need for bulk PV recycling by several years. This review presents a different perspective to the common discourse on the topic, by giving special emphasis to the potential to further integrate AV into agriculture, which has the potential to facilitate the resolution of relevant legal disputes over the use of AV.
Air Emissions and Health Impacts of Two Hydrogen‐Based Electricity Generation Methods
Authors: Safaei Elaheh , Kelly Kerry
Published: December 2024

Electricity production using fossil fuels contributes to air pollution and adverse health impacts. One option for decreasing fossil fuel consumption is replacing fossil fuel power plants with electricity produced from green hydrogen (H2, produced from renewable sources). Previous studies mainly focused on greenhouse gas emissions from two common H2 production methods, steam methane reforming (SMR) and water electrolysis. This study compares the estimated emissions and associated health outcomes of generating electricity from fossil fuels with electricity generated from H2 produced through SMR or electrolysis in various regions of the United States. Shifting from coal‐generated electricity to SMR‐produced H2‐generated electricity results in health benefits while shifting from natural gas‐generated electricity to electricity generated from H2 generated via water electricity results in health costs in all regions. Depending on the region, replacing a natural gas power plant with electricity generated from H2 produced via SMR or replacing a coal power plant with electricity generated from water electrolysis could result in either health benefits or costs. This study also considers the impact of plant location on human health outcomes as well as the impact of increasing renewable energy percentages on health outcomes associated with replacing a coal or natural gas power plant with electricity generated from H2 produced through grid‐based water electrolysis. The results indicate that a high renewable fraction (over 85% of the grid) is required to experience health benefits, emphasizing the challenges associated with moving toward electrolysis‐based H2 production for electricity generation.
Frequency‐Power Coupling Dynamic Response and Regulation Characteristics of Variable Speed Pumped Storage Unit With Full‐Size Converter
Authors: Li Yanhao , Shu Kedong , Guo Wencheng
Published: December 2024

This paper aims to study the frequency‐power coupling dynamic response and regulation characteristics of a variable speed pumped storage unit (VSPSU) with full‐size converter (FSC). Firstly, the mathematical model of VSPSU with FSC is established. Secondly, the dynamic response of VSPSU with FSC under power disturbance is simulated, and the effect of operating speed on dynamic response of VSPSU with FSC is analyzed. Then, the frequency‐power coupling regulation characteristics of VSPSU with FSC are revealed. Finally, the dynamic responses between VSPSU with FSC and fixed speed pumped storage unit (FSPSU) are compared. The results show that, with the same disturbance amplitude, the variation times of speed and output under positive power disturbance are longer than those under negative power disturbance. With a negative power disturbance of larger amplitude, the speed and output of VSPSU have a faster response. The regulation characteristics of VSPSU can be improved by adjusting both the parameters of governor and converter based on the operation requirements. Under both the positive and negative power disturbances, the dynamic response of active power of VSPSU is faster than that of FSPSU. Under the negative power disturbance, the dynamic response of speed of VSPSU is slightly slower than that of FSPSU.
The Spatio‐Temporal Characteristics of Flow Field Inside a Self‐Priming Pump During the Self‐Priming Process
Authors: Zhang Yu‐Liang , Li Jin‐Fu , Zhao Yan‐Juan , Guo Xiao‐Mei , Zhu Zu‐Chao
Published: December 2024

In this article, a closed‐loop piping system that includes the self‐priming pump is established and calculated. Two operating processes reflecting real situations are accurately calculated by means of UDF. The vortex identification method, entropy production theory, and energy gradient method are employed to deeply analyze and reveal the energy loss characteristics and flow stability. The results show that in the oscillating exhaust stage, the energy loss is greatest during the oscillating exhaust stage of the self‐priming process. The reflux hole, the tongue, and the outlet section of the volute have larger energy loss. Within the impeller region, the entropy production is mainly concentrated at the impeller inlet and outlet; the entropy production distribution area and value are larger in the clearance of the wear‐ring. In addition, the instability region in the impeller and the left side of the volute is significantly larger than the rest of the locations and increases considerably with the self‐priming process.
Experimental Study on the Damage Evolution Mechanism of Siltstone by Water Content and Confining Pressure
Authors: Shiyu Tian , Lulin Zheng , Hao Liu , Hong Lan , Weide Ren , Youwen Tian , Jin Xu
Published: December 2024

Prolonged exposure of deep coal mines to erosion from groundwater results in a gradual accumulation of rock mass damage, which can lead to geological hazards such as deformation and instability. These challenges significantly impact the safe operation of deep coal mines. To understand the mechanisms behind siltstone damage progression related to water content and confining pressure, this study explores the influence of these factors on the deformation and damage evolution of siltstone, employing a combination of rock mechanics testing, numerical simulation, and CT scanning techniques. Results demonstrate that increasing water content reduces the compressive strength of rock, leading to more complex failure modes. In contrast, higher confining pressure strengthens the compressive capacity, thereby suppressing the formation and growth of transverse cracks under compression. Using Avizo software, a three‐dimensional model of siltstone was developed to visualize the distribution of fractures in a three‐dimensional field. In the MATLAB platform, a box dimension algorithm based on three‐dimensional digital volume imaging was developed, employing box dimension theory and digital image storage methods. Fractal analysis reveals that the fractal dimension of internal fractures in loaded samples increases linearly with water content, indicating more extensive fracture development and greater specimen damage. Applying the box dimension from three‐dimensional digital volume images as a metric facilitates characterizing the damage evolution in siltstone under different water content conditions. This approach provides a new means to quantitatively evaluate the growth and complexity of internal fractures in siltstone, offering insights into rock damage progression under varying moisture conditions.
Postfire Estimation of Heating Temperatures Experienced by Fire Retardant Coatings Using Smartphone Videos and Machine Learning
Authors: Zhu Zhichao , Song Weiran , Yue Xin , Lyu Yihan , Wang Ji
Published: December 2024

Accurate estimation of heating temperatures experienced by fire retardant coatings (FRCs) is crucial in identifying the ignition source during fire investigations. While traditional methods, such as spectroscopy, effectively capture the compositional changes in FRC at various heating temperatures, they are typically bulky, costly, and unsuitable for rapid field analysis. This study proposes the use of smartphone and machine learning to predict the heating temperatures of FRC. A smartphone is employed to capture short videos of FRC samples illuminated by its color‐changing screen. Video frames are then decomposed into color images and converted into spectral data for further processing. Linear and nonlinear regression models are applied to identify key variables and enhance predictive accuracy. The performance of smartphone‐based temperature estimation is compared to that of hyperspectral imaging and laser‐induced breakdown spectroscopy. In the test phase, the coefficient of determination for smartphone‐based estimation ranges from 0.946 to 0.962, often surpassing that of benchmark methods. These results indicate that smartphones can provide a low‐cost, effective means for estimating heating temperatures of FRC in fire investigations.
Current Status and Applications of Genome‐Scale Metabolic Models of Oleaginous Microorganisms
Authors: Hu Zijian , Qian Jinyi , Wang Yuzhou , Ye Chao
Published: December 2024

Oleaginous microorganisms have the unique ability to accumulate lipids that can exceed 20% of their dry cell weight under certain conditions. Despite their potential for efficient lipid production, the metabolic pathways involved are not yet fully understood, largely due to the complexity of intracellular processes and the challenges in phenotypic prediction. This review synthesizes the latest research on the application of Genome‐scale Metabolic Network Models (GSMMs) to study oleaginous microorganisms, including bacteria, cyanobacteria, yeast, microalgae, and fungi, and provides a comprehensive analysis of how GSMMs have been utilized to decipher the metabolic mechanisms behind lipid accumulation and to identify key genes involved in lipid synthesis. The review highlights the role of GSMMs in predicting cellular behavior, optimizing metabolic engineering strategies, and discusses the future directions and potential of GSMMs in enhancing lipid production in microorganisms. This comprehensive overview not only summarizes the current state of research but also identifies gaps and opportunities for further investigation in the field.
Is transoral robotic surgery useful as a salvage technique in head and neck cancers: a systematic review and meta analysis
Authors: Goel Sahil , Gunasekera Delu , Krishnan Giri , Krishnan Suren , Hodge John‐Charles , Lizarondo Lucylynn , Foreman Andrew
Published: December 2024

Background

Residual, recurrent, and second primary head and neck cancers are on the rise. This is largely driven by a younger age at diagnosis and increasingly targeted chemoradiotherapy options. Salvage surgery remains the only curative intent option in this cohort of patients. With transoral robotic surgery (TORS), achieving good oncological and functional outcomes in primary cancer cohorts, there remains a paucity of synthesized evidence on treating residual, recurrent, or second primary disease in previously irradiated fields.

Methods

Conducted in accordance with the JBI's methodology for systematic reviews of effectiveness, three databases were searched including PubMed, Embase, and Scopus. This study represents the largest systematic review till date finding 679 studies and including 15 after screening and critical appraisal. A meta‐analysis of proportions and comparison was conducted using Freeman–Tukey arcsine transformation statistical method and the Mantel–Haenszel statistical method, respectively.

Results

Data from 515 patients was analyzed with a median follow‐up time up to 47 months and a mean hospital stay of 8.5 days. Two‐year overall survival (OS) rate and disease‐free survival (DFS) rate were 73.8% and 56.1%, respectively. Compared to primary head and neck cancer, risk ratios for OS and DFS were 0.35 (95% CI, 0.18–0.67) and 0.44 (95% CI, 0.22–0.88). Weighted mean for tracheostomy decannulation and nasogastric dependence was 9.7 and 12.8 days, respectively, with long term tracheostomy dependence in 0%–11.5% of patients. Positive surgical margins were obtained in 19.4% with a risk ratio of 1.08 (95% CI, 0.66–1.75) when compared to primary head and neck cancer. Recurrence rate was 36% (95% CI, 24–48.9). Pooled complication rate was 32.3% with 92% of complications being classed as Clavien Dindo grade 2 or 3.

Conclusion

TORS is an emerging technique for salvage in recurrent, residual, and second primary head and neck cancers in previously irradiated fields. Survival outcomes are encouraging with decreased morbidity and mortality rates when compared to traditional open surgical techniques. Future studies need to mandate collection of swallowing data as a key tool to evaluate functional outcomes, deploy longer follow‐up times, and address confounding factors including HPV status and prior adjuvant therapy.
The Growing Mpox Infections by Clade I Variant in African Countries Is a Public Health Emergency of International Concern: A Narrative Review
Authors: Urmi Taslima Jamal , Islam Md. Rabiul
Published: December 2024

Background and Aim

In 2022, the monkeypox (mpox) outbreak was declared a public health emergency of international concern. The emergence of a new strain in the Democratic Republic of the Congo and its identification with neighboring countries led to the declaration of a public health emergency in 2024. The objective is to focus on the recent outbreak that led to its declaration as a Public Health Emergency of International Concern, assess the significant global public health threat posed by the newly identified class, and explore effective strategies to address this situation.

Methods

The present review searched information from databases (PubMed and Scopus), WHO, and the European Centre for Disease Prevention and Control. The search methods followed database‐specific criteria. Key terms included mpox, prevalence, public health emergency, treatment, new variant, prevention, and strategy. We reviewed and extracted information from the relevant literature.

Results

Mpox has been endemic in the Democratic Republic of the Congo for over a decade, with a consistent annual rise in reported cases. In August 2024, at least 13 African countries have confirmed 2,863 cases and 517 fatalities. The recent emergence and transmission of a new strain, which appears to be predominantly spreading through sexual networks, along with its identification in neighboring countries, raises significant concerns for public health.

Conclusion

The emergence of the new clade of mpox represents a critical public health challenge that necessitates immediate and coordinated global response efforts. By addressing the current outbreak comprehensively, we can mitigate its impact and safeguard public health across affected regions.
Exploring Prevalence and Sociodemographic Factors Associated With Smoking Among Malaysian Adults: A Cross‐ Sectional Study
Authors: Ja'afar Mohd Hasni , Ismail Rosnah , Md Isa Zaleha , Mohd Tamil Azmi , Ismail Noor Hassim , Mat Nasir Nafiza , Nasir Nik Munirah , Ab Razak Nurul Hafiza , Zainol Abidin Najihah , Mente Andrew , Yusof Khairul Hazdi
Published: December 2024

Background and Aims

The Malaysian government has implemented various antismoking measures to reduce the incidence of unhealthy lifestyles within the population. This study analyzes the baseline data of the Prospective Urban Rural Epidemiology (PURE) study to establish the prevalence of sociodemographic factors that are associated with smoking habits among Malaysian adults.

Methods

This study was carried out in urban and rural communities with adults aged between 35 and 70 years using purposive sampling. Standardized questionnaires were used to assess the smoking status and sociodemographic data of the participants. Bivariate analysis and multiple logistic regression were done to determine the association between smoking status and demographic characteristics among Malaysian adults.

Results

The prevalence of smoking among adults is 23.2%. The sociodemographic factors significantly associated with active smoking status were being a younger adult (adjusted odds ratio [AOR] = 1.26, 95% CI: 1.06–1.50), being male (AOR = 24.16, 95% CI: 20.58–28.36), being Malay (AOR = 1.72, 95% CI: 1.49–1.98), being a blue‐collar worker (AOR = 1.75, 95% CI: 1.48–2.06), having no formal education (AOR = 1.99, 95% CI: 1.56–2.53), being unmarried (AOR = 1.22, 95% CI: 1.02–1.48) and being of low socioeconomic status (AOR = 1.45, 95% CI: 1.14–1.84).

Conclusion

Public health policies and actions on smoking reduction should emphasize those identified as high‐risk sub‐populations, particularly younger adults, males and those who are not yet married, have no formal education and are of low socioeconomic status.
Gut Bifidobacterium pseudocatenulatum protects against fat deposition by enhancing secondary bile acid biosynthesis
Authors: Zha Andong , Qi Ming , Deng Yuankun , Li Hao , Wang Nan , Wang Chengming , Liao Simeng , Wan Dan , Xiong Xia , Liao Peng , Wang Jing , Yin Yulong , Tan Bi'e
Published: December 2024

Gut microbiome is crucial for lipid metabolism in humans and animals. However, how specific gut microbiota and their associated metabolites impact fat deposition remains unclear. In this study, we demonstrated that the colonic microbiome of lean and obese pigs differentially contributes to fat deposition, as evidenced by colonic microbiota transplantation experiments. Notably, the higher abundance of Bifidobacterium pseudocatenulatum was significantly associated with lower backfat thickness in lean pigs. Microbial‐derived lithocholic acid (LCA) species were also significantly enriched in lean pigs and positively correlated with the abundance of B. pseudocatenulatum. In a high‐fat diet (HFD)‐fed mice model, administration of live B. pseudocatenulatum decreased fat deposition and enhances colonic secondary bile acid biosynthesis. Importantly, pharmacological inhibition of the bile salt hydrolase (BSH), which mediates secondary bile acid biosynthesis, impaired the anti‐fat deposition effect of B. pseudocatenulatum in antibiotic‐pretreated, HFD‐fed mice. Furthermore, dietary LCA also decreased fat deposition in HFD‐fed rats and obese pig models. These findings provide mechanistic insights into the anti‐fat deposition role of B. pseudocatenulatum and identify BSH as a potential target for preventing excessive fat deposition in humans and animals.
Projected Climate Scenarios Reveal an Expanding Suitable Habitat for the Critically Endangered African White‐Backed Vulture Gyps africanus
Authors: Zvidzai Mark , Zengeya Fadzai M. , Masocha Mhosisi , Murwira Amon , Tagwireyi Paradzayi
Published: December 2024

Estimating the potential distribution of climatically suitable habitats for different species is important for developing targeted and adaptable biodiversity conservation strategies. However, such crucial information remains limited for obligate scavengers such as the Critically Endangered (CE) African White‐backed Vulture (AWbVs) Gyps africanus. In this study, we applied two Species Distribution Modelling (SDM) algorithms, MaxEnt and BIOCLIM, within the Wallace interface to predict changes in the climatically suitable geographic ranges of the AWbVs under current, 2050, and 2070 climate scenarios in the Hwange ecosystem. Using 19 dynamic bioclimatic variables, five Global Circulation Models (GCMs), and two Representative Concentration Pathways (RCPs), we modelled the potential impacts of climatic changes on AWbVs geographic ranges. This analysis incorporated 89,809 GPS occurrence data points collected from six AWbVs that were captured and tracked in Hwange National Park and its surrounding areas. Model performance was robust, with a high overall mean AUC of 0.89. Our results indicate that climatic suitability within protected areas is expected to remain stable under future climate change scenarios. In addition, models developed in this study suggest that suitable habitats for the AWbVs are expected to expand significantly by 2050 and 2070, extending towards human‐dominated landscapes. Given the critical conservation status of the AWbVs, these findings offer valuable insights that can inform current and future conservation strategies.
6‐Chloronicotinic Acid Induces Toxicity in Mouse Neural Stem Cells via the C3ar1 Signaling
Authors: He Min , Lin Yahang , Zhang Xiaojing , Wang Siyi , Yang Xinyu , Cui Fengzhen , Sheng Xia
Published: December 2024

Neural stem cells (NSCs) are essential for brain development due to their ability to proliferate and differentiate into various neural cell types. Neonicotinoid insecticides (NNIs), which have replaced traditional pesticides, are now widely used and frequently detected in environmental and biological samples. Prenatal exposure to NNIs has been associated with an increased risk of neurodevelopmental disorders in offspring, yet the causal relationship and the underpinning mechanism remain to be clarified. As one of the primary metabolites of chloropyridinyl neonicotinoids, 6‐chloronicotinic acid (6‐ClNA) has been identified as a potential neurotoxin, though its effects on NSCs have not been fully explored. Here, we demonstrate that 6‐ClNA exposure significantly disrupted NSC proliferation and differentiation in vitro. Transcriptomic analyses revealed that 6‐ClNA altered the expression of pathways related to proliferation, apoptosis, and inflammation, with notable activation of the C3ar1/C1qa signaling axis. Genetic ablation of C3ar1 using siRNA markedly restored NSC proliferation and neurosphere formation, as well as reduced apoptosis, suggesting a central role of C3ar1/C1qa in mediating 6‐ClNA's neurotoxic effects. These findings imply that early‐life exposure to NNIs may affect the fitness and function of NSCs, wherein the C3ar1 pathway plays an indispensable role.
Improving surgical performance of free gingival graft harvesting through training and instruction
Authors: De Greef Alexander , Stankov Ventseslav , Siawasch Manoetjer , Teughels Wim , Temmerman Andy , Castro Ana
Published: December 2024

Objective

The present study assessed the influence of training and instruction on fine motor skills in periodontal plastic surgery.

Methods

Undergraduate dental students (n = 41) at the University of Leuven were randomly assigned to four different training groups, each with varying training intervals and total durations. These students were further categorized into two learning approaches: implicit (n = 21) and explicit (n = 20). Initially, the unexperienced participants were tasked with harvesting a free gingival graft on an apple with specified dimensions. They were evaluated on following parameters: surgical outcome, efficiency, and execution. After a 3‐week training period, participants repeated the technical test from baseline, with a surprise test featuring altered graft dimensions.

Results

All proposed aspects of surgical performance improved during training, including graft volumetric precision (p = 0.14), completion time (p = 0.05), and Objective Structured Assessment of Technical Skills scoring (p < 0.001). “Daily trainers” outperformed “weekly trainers,” followed by “one‐time trainers,” with “zero trainers” showing the least improvement. Regarding instruction, the implicit learning approach solely demonstrated significantly reduced task completion time during the surprise test (p < 0.001).

Conclusions

These findings highlighted the benefit of frequent training on surgical performance for novice trainees learning the execution of a specific periodontal procedure, while increased instruction intensity did not yield additional advantages.
Medial patellofemoral ligament reconstruction normalizes patellar kinematics but fails to predict cartilage contact area: A prospective 3D MRI study
Authors: Siegel Markus , Maier Philipp , Taghizadeh Elham , Meine Hans , Lange Thomas , Fuchs Andreas , Yilmaz Tayfun , Schmal Hagen , Izadpanah Kaywan
Published: December 2024

Introduction

The medial patellofemoral ligament (MPFL) is the main patellar stabilizer in low knee flexion degrees (0–30°). Isolated MPFL reconstruction (MPFLr) is therefore considered the gold standard of surgical procedures for low flexion patellofemoral instabilities (PFIs). Despite excellent clinical results, little is known about the effect of MPFLr on kinematic parameters (KPs) of the patellofemoral joint in vivo. This study investigates the effect of MPFLr on KP of patellofemoral articulation, using a three‐dimensional (3D) in vivo magnetic resonance imaging (MRI) analysis at different flexion and loading positions, and analyzes the correlation of these parameters with the patellofemoral cartilage contact area (CCA).

Methods

In this prospective, matched‐pair cohort study of 30 individuals, 15 patients with low flexion PFI and 15 knee‐healthy individuals were included. Patients were analyzed pre and post‐operatively after MPFLr. MRI images were obtained at 0°, 15° and 30° with and without muscle activation, using a custom‐designed pneumatic loading device. Patellar shift, tilt and rotation were determined in 3D bone and cartilage models of each individual, guaranteeing the highest reliability. Subsequently, the KPs were correlated with patellofemoral CCA.

Results

Patients with low flexion PFI had a leg geometry of 0.5 ± 2.6° valgus and a TTTG of 11.4 ± 4.4 mm. Eleven patients had moderate (Type A/B) and 2 had severe (Type C/D) trochlear dysplasia. Without muscle activation, patients showed significantly increased patellar shift (0–30°; p0° = 0.011, p15° = 0.004 and p30° = 0.015) and tilt (15°; p15° = 0.041). Muscle activation did not compensate for maltracking in these patients, but even increased tilt and shift further in extension (p0° = 0.002 and p0° = 0.001). MPFLr statistically reduced patellofemoral tilt from 0° to 30° flexion during passive flexion and tended to approach the values of knee‐healthy individuals (pext = 0.008, p15° = 0.006 and p30° = 0.003). Post‐operatively, muscle activation led to comparable tilt and shift as in healthy individuals. Tilt, shift and rotation did not correlate with CCA neither in healthy individuals nor in pre‐ or post‐operative patients.

Conclusion

Isolated MPFLr can normalize patellar shift and tilt in patients with low flexion instability. Considering the influence of muscle activation, passive stabilization through MPFLr seems to be the basic precondition for physiologically active patella stabilization. The investigated KPs as easy‐to‐measure parameters in clinical practice cannot be used to assume normalized CCA for low flexion degrees. Therefore, methodologically demanding methods are still required to calculate the patellofemoral CCA.

Level of Evidence

Level II.
Preoperative difference between 2D and 3D planning correlates with difference between planned and achieved surgical correction in patient‐specific instrumented total knee arthroplasty
Authors: Pflüger Patrick , Pedrazzini Alberto , Jud Lukas , Vlachopoulos Lazaros , Hodel Sandro , Fucentese Sandro F.
Published: December 2024

Purpose

The goals of this study were (1) to assess whether the preoperative difference between modalities and extent of deformity are associated with a higher difference between planned and achieved surgical correction and (2) if they yield a higher probability of intraoperative adjustments.

Methods

Retrospective single‐centre analysis of patients undergoing patient‐specific instrumented (PSI) total knee arthroplasty (TKA). Preoperative radiographic parameters were analysed on weightbearing (WB) long‐leg radiographs (LLR) and nonweightbearing (NWB) computed tomography (CT). The 2D/3D difference was calculated as the difference between preoperative WB‐LLR (2D) hip–knee–ankle angle (HKA), and NWB CT (3D) HKA. Surgical records were screened to retrieve intraoperative adjustments to the preoperative plan. Postoperative assessment was performed on WB LLR.

Results

Two‐hundred‐eighty‐two knees of 263 patients were analysed. The difference of postoperative achieved to planned HKA (HKADifference) was 2.2° ± 1.7°. The preoperative 2D HKA showed the highest correlation with HKADifference (r = −0.37, 95% confidence interval [CI]: −0.48 to −0.26, p < 0.001). Intraoperative adjustments were performed in 60% (n = 170) of all knees. Patients with a preoperative coronal deformity of >7.8° had 10.55 higher odds for an intraoperative coronal adjustment (95% CI: 4.60–24.20, p < 0.001).

Conclusion

The extent of deformity is associated with residual coronal deformity following PSI‐TKA. Patients with extensive coronal malalignment may benefit from an adaptation of the preoperative surgical plan to avoid unintended postoperative coronal malalignment. Despite the advancements with 3D preoperative planning, intraoperative adjustments in PSI‐TKA are frequently performed, in particular in patients with a higher preoperative varus/valgus deformity.

Level of Evidence

Level III.
Patient‐specific cutting guides allow 1° precision in asymmetric anterior closing‐wedge osteotomy
Authors: Leluc Julien , Mabrouk Ahmed , Hirth Jacob , Nawabi Danyal , Jacquet Christophe , Ollivier Matthieu
Published: December 2024

Purpose

Asymmetric anterior closing‐wedge high tibial osteotomy (ACWHTO) allows correction of both excessive posterior tibial slope (PTS) and varus deformity. However, the complexity of this surgery requires a high degree of accuracy, which is less likely to be achieved with standard instrumentations. This study aimed to determine the accuracy of 3D patient‐specific cutting guides (PSCGs) to provide the accurate planned correction in the frontal and sagittal planes.

Methods

Eight sawbones tibiae were identically printed from the same patient data. An ACWHTO with a PSCG was performed on each sawbone. Postoperative measurements of PTS, mechanical medial proximal tibial angle (mMPTA), hinge area and hinge–posterior cruciate ligament (hinge–PCL) distance were compared with the preoperative planned measurements. The precision was defined as the absolute difference (∆) between the target planned values and postoperative values.

Results

The mean accuracy was 0.6° ± 0.74° for PTS, 0.8° ± 0.71° for mMPTA, 0.3 ± 0.2 cm2 for hinge area and 0.1 ± 0.06 mm for hinge–PCL distance.

Conclusion

In the setting of sawbones, the use of PSCGs was a reliable and accurate method of achieving simultaneous correction in the frontal and sagittal planes during asymmetric ACWHTO.

Level of Evidence

Level V, basic science biomechanical laboratory study.
High incidence of anterior cruciate ligament injuries in professional men's handball: Analysis of the ‘ACL registry in German Sports’ over seven consecutive seasons
Authors: Resch Tobias , Krutsch Werner , Weber Johannes , Krueckel Jonas , Hartz Frederik , Alt Volker , Achenbach Leonard , Szymski Dominik
Published: December 2024

Purpose

The purpose of this study was to generate knowledge about the epidemiology and risk factors for anterior cruciate ligament (ACL) injuries in handball. It was hypothesised that the incidence of ACL injuries is high and comparable to other pivoting sports like football.

Methods

This study is based on the prospective ‘ACL registry in German Sports’ implemented in the 2016–2017 season. Professional (first and second leagues) male handball players were analysed regarding the incidence and risk factors for ACL injuries. Injuries were registered according to the direct reports of the injured players to the study office and double‐checked via media analysis. After injury registration, the players received a standardised questionnaire. Data were analysed from the 2016–2017 to the 2022–2023 season.

Results

A total of 84 ACL injuries were registered. 46.3% of ACL injuries were re‐ruptures. This represents a total incidence of 0.044 ACL injuries per 1000 h of exposure in training and matches per player over the study period. An increased incidence rate of 0.064/1000 h in the first league compared to 0.031/1000 h in the second league was reported (p ˂ 0.001). The mean number of injuries in the first division was 8.3, and in the second division, 6.6 ACL ruptures per season. Risk factors for ACL injury include previous knee injury and increased match exposure.

Conclusion

The incidence of ACL injuries in professional handball is high and comparable to football with an increased risk in the first league compared to the second league in Germany. There was a high incidence of re‐injury. Other risk factors for ACL injuries include previous injuries to the affected knee in general as well as increased match exposure.

Level of Evidence

Level II prospective cohort study.
One‐Pot Sequential Four‐Component Reaction for the Synthesis of Novel Dihydro Oxaphospholo Pyrazole 2‐Oxides in Acetic Acid Medium
Authors: Wu Mingshu , Sun Zhengfan , Ning Rui , Yan Ziwen , Ma Junying , Fan Siqi
Published: December 2024

A four‐component one‐pot sequential approach to five‐membered oxaphosphaheterocycles have developed. The method involves in situ generation of methylpyrazolin‐5‐one from ethyl acetoacetate and phenyl hydrazine. Further, a sequential reaction of methylpyrazolin‐5‐one with various aromatic aldehydes and phenyl dichloro phosphine afforded dihydro oxaphospholo pyrazole 2‐oxide derivatives.
Evaluating CMIP6 Global Climate Models Performances Over Nigeria: An Integrated Approach
Authors: Shiru Mohammed Sanusi , Kim Dongkyun , Chung Eun‐Sung
Published: December 2024

The choice of global climate models (GCMs) for climate or hydrological studies remains a challenge due to their temporal and spatial variations and different performances in different parts of the globe. This study assesses the performances of 33 GCMs of the Coupled Model Intercomparison Project Phase 6 (CMIP6) for precipitation, maximum temperature and minimum temperature over Nigeria in order to select the best performing GCMs for aggregation into a multi model ensemble (MME). The study uses three statistical metrics (SM) and Random Forest (RF) machine learning method for the evaluation of the GCMs. In addition, the GCM performances were also estimated using spatial assessment, boxplots, scatter plots and mean monthly comparison at each grid point over the period 1985–2014. Finally, the average was used to generate variations of MMEs by increasing the number of models in the MME considering the inclusion of the better ranking ones first in order to determine the optimum MME for the variables. The highest ranking GCMs based on the average of the scores of the SM and RF were NESM3, CMCC‐ES, IPSL‐L‐R‐INCA and IPSL‐L‐R, MPI‐HAM and SAMO‐UNICON for precipitation; BCC‐C‐MR, MRI‐ESM, BCC‐ESM1, ACC‐ESM1‐5 and GISS‐E2‐CC for maximum temperature; and GFDL‐ESM, AWI‐C‐MR, IPSL‐L‐R, CAS‐ESM2 and AWI‐C‐LR for minimum temperature. The highest‐ranking model for all variables is ACC‐ESM1‐5, which ranked highest with a score of 0.6920 followed by BCC‐C‐MR with 0.6898, CAS‐ESM2 with 0.6597 and BCC‐ESM1 with 0.6545 score. The results of the spatial assessment, boxplots, scatter plots and the mean monthly comparison aligns with this. In the aggregation of MME for the three variables, the optimum number of models was obtained after averaging of the first four best ranking GCMs. This study presents a localised study, which is expected to reduce uncertainty in the projection of climate over Nigeria.
Serum bile acids early after portoenterostomy are predictive for native liver survival and portal hypertension in biliary atresia
Authors: Anderson Linda , Hukkinen Maria , Nyholm Iiris , Niemi Mikko , Pakarinen Mikko P.
Published: December 2024

Objectives

To compare the predictive value of serum bile acids on native liver survival (NLS) and portal hypertension (PH) at various time points early after portoenterostomy (PE) in biliary atresia (BA).

Methods

This was a retrospective observational study. Serum bilirubin and bile acid concentrations were defined by enzymatic spectrophotometry 1, 3, and 6 months after PE. After defining optimal bilirubin and bile acids cutoffs by area under the receiver operating characteristic (AUROC) curves, cutoffs were compared with other predictors of NLS and PH in Cox regression.

Results

Out of 56 patients, 42 (75%) achieved clearance of jaundice (COJ, bilirubin <20 µmol/L at 6 months). Both bilirubin and bile acids at 3 and 6 months were accurate predictors of NLS among all patients (AUROC 0.82–0.91, p < 0.001). In COJ patients, bile acids (AUROC 0.82, p = 0.003), but not bilirubin, at 1 month also predicted NLS. Among all patients, the strongest predictors of NLS were bilirubin >18.5 µmol/L and bile acids >150 µmol/L at 3 months, increasing the risk of transplantation/death seven‐ and eightfold, respectively (p < 0.001 for both). In COJ patients, the strongest predictor of NLS was bile acids >119 µmol/L at 3 months, increasing the risk of transplantation/death 12‐fold (p = 0.014). Bile acids and bilirubin at 3 and 6 months predicted PH development in COJ patients with moderate accuracy (AUROC 0.72–0.78, p = 0.004–0.019). Bilirubin >8.5 µmol/L and bile acids >78 µmol/L at 6 months increased PH risk 13‐fold (p < 0.001) and 4‐fold (p = 0.006).

Conclusions

Serum bile acids offer a simple and useful additional tool to predict PE outcomes in BA, particularly after COJ.
Real World Data in Stage III Melanoma in Latino Low Middle Income Country: Prognostic Factors and Outcomes
Authors: De La Cruz Ku Gabriel , Guart Jiddu Antonio , Farzan Jessica J. , Desai Anshumi , Franco Camila , Mroueh Jessica , Mroueh Vanessa , Ziegler‐Rodriguez Gonzalo
Published: December 2024

Introduction

Malignant melanoma is a heterogeneous disease, with varying outcomes depending on the patient's race and ethnicity. Advanced stages can be tackled by novel targeted therapies and immunotherapy. We aimed to investigate the real‐world data in Latino‐Hispanic patients diagnosed with Stage III melanoma residing in Peru, a region marked by limited resources and healthcare infrastructure.

Methods

Patients diagnosed with Stage III melanoma at the Instituto Nacional de Enfermedades Neoplasicas, Lima, Peru were included from the years 2010 to 2020. Cox regression analysis was used to assess prognostic factors.

Results

Four hundred twelve patients were included, the median age of diagnosis was 63 years, with a male predominance (55.6%). Most of the patients presented with a lesion in the lower extremities (77.4%), acral lentiginous melanoma (35.4%), and ulcerated tumors (72.3%). 64.1% were diagnosed with Stage IIIC, and 27.2% received interferon‐alpha therapy. With a median follow‐up of 36 months, the relapse‐free survival and overall survival rates were 26% and 78% at 3 years follow‐up, respectively. Prognostic factors of event‐free survival (EFS) were greater age (HR = 1.015, 95% CI: 1.005–1.025), ulcerated lesions (HR = 1.855, 95% CI: 1.221–2.820), N category, and the administration of interferon therapy (HR = 0.680, 95% CI: 0.488–0.947). While worse overall survival (OS) was associated with greater ages (HR = 1.032, 95% CI: 1.011–1.053) and the presence of ulceration (HR = 2.992, 95% CI:1.142–7.835).

Conclusion

Stage III melanoma in the Hispanic‐Latino population from Peru has worse survival rates than other races and populations despite similar prognostic factors of worse EFS and OS. In resource‐limited settings, reducing barriers to receiving healthcare and broadening access to contemporary immunotherapy and targeted therapy are crucial measures to improve outcomes in patients with advanced melanoma.
A study of specific immunoglobulin G4 expression in allergic rhinitis and its value in assessing efficacy and in predicting prognosis of sublingual immunotherapy
Authors: Wei Ting‐Ting , Gao Kai , Tai Jun‐Hu , Wei Yong‐Jun , Zhan Bin
Published: December 2024

Allergic rhinitis (AR) is a widespread health issue with a rising global prevalence, and sublingual immunotherapy (SLIT) has shown efficacy in AR treatment. We examined specific immunoglobulin G4 (sIgG4) expression in AR and its role in evaluating SLIT efficacy and predicting patient prognosis. We compared total nasal symptom score (TNSS), total medication score (TMS), visual analogue scale (VAS) score, inflammatory cytokines, and immune function markers in AR patients before and after SLIT. SLIT reduced TNSS, TMS, VAS scores, IL‐4, IL‐17, eosinophilia percentage (EOS%), and specific immunoglobulin E (sIgE) levels, while increasing INF‐γ, IL‐10, and sIgG4. The sIgG4 level at pre‐treatment and 12 months post‐treatment was negatively correlated with TNSS, TMS, VAS score, IL‐4, IL‐17, EOS%, and sIgE, and positively correlated with IFN‐γ and IL‐10. Most patients showed symptomatic improvement. After 12 months, sIgG4 level demonstrated an area under the curve (AUC) of 0.867 for assessing SLIT as effective. Pre‐treatment sIgG4 level showed an AUC of 0.869 for predicting SLIT as effective. Collectively, sIgG4 has strong potential assessing SLIT efficacy and prognosis in AR patients, with correlations to TNSS, TMS, VAS score, and IL‐4, IL‐10, IL‐17, INF‐γ, EOS% and sIgE levels.
Safety of transarterial chemoembolization on renal function in combined hepatocellular carcinoma and chronic kidney disease patients
Authors: Lin Zu‐Yau , Yeh Ming‐Lun , Liang Po‐Cheng , Huang Chung‐Feng , Huang Jee‐Fu , Dai Chia‐Yen , Yu Ming‐Lung , Chuang Wan‐Long
Published: December 2024

This study was to investigate the safety of transarterial chemoembolization (TACE) which required injection of contrast medium on renal function in combined hepatocellular carcinoma and chronic kidney disease (CKD) patients. A total of 265 patients admitted for the first session of TACE were included for analysis. CKD was defined as Cockcroft‐Gault glomerular filtration rate (CG‐GFR) < 60 mL/min/1.73 m2. The odds ratio (OR) and 95% confident interval (CI) were calculated to show the influence of factors on renal function. Overall, 24.07% patients with CKD and 31.21% patients without CKD showed exacerbated renal function at discharge. However, 73.15% patients with CKD and 63.69% patients without CKD showed significantly improved renal function (all p = 0.00001). No significant difference in influence of TACE on renal function between patients with and without CKD (p = 0.20509). Factors to exacerbate the serum creatinine level at the third day after TACE included proteinuria ≥1+ (OR 2.2469, 95% CI = 1.1559–4.3675) and glycated hemoglobin ≥7% (OR 2.0796, 95% CI = 1.0497–4.1200). These factors could be obliterated by admission for more than 3 days after TACE. Serum albumin level <3 g/dL at admission was the only factor to exacerbate renal function at discharge (OR 4.4179, 95% CI = 1.3964–13.9776). In conclusion, TACE exerted same influence on renal function between patients with and without CKD. Most patients showed improved renal function at discharge. Low serum albumin level, proteinuria and poor diabetes mellitus control were factors to exacerbate renal function after TACE.