bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of MTHFR (C677T, A1298C) and MTRR A66G polymorphisms with fatty acids profile and risk of neural tube defects
Authors: Nasri Kaouther , Ben Jamaa Nadia , Gaigi Soumeya Siala , Feki Moncef , Marrakchi Raja
Published: May 2024

Objective

This study aims to determine if 5,10‐methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and methionine synthase reductase (MTRR A66G) gene polymorphisms were associated with fatty acid (FA) levels in mothers of fetuses with neural tube defects (NTDs) and whether these associations were modified by environmental factors.

Methods

Plasma FA composition was assessed using capillary gas chromatography. Concentrations of studied FA were compared between 42 mothers of NTDs fetuses and 30 controls as a function of each polymorphism by the Kruskal–Wallis nonparametric test.

Results

In MTHFR gene C677T polymorphism, cases with (CT + TT) genotype had lower monounsaturated FA (MUFA) and omega‐3 polyunsaturated FA (n‐3 PUFA) levels, but higher omega‐6 polyunsaturated FA (n‐6 PUFA) and omega‐6 polyunsaturated FA: omega‐3 polyunsaturated FA (n‐6:n‐3) ratio levels. In MTRR gene A66G polymorphism, cases with (AG + GG) genotype had lower MUFA levels, but higher PUFA and n‐6 PUFA levels. Controls with (AG + GG) genotype had lower n‐6 PUFA levels. In MTHFR gene C677T polymorphism, cases with smoking spouses and (CT + TT) genotype had lower MUFA and n‐3 PUFA levels, but higher PUFA, n‐6 PUFA, and n‐6:n‐3 ratio levels. Cases with (CT + TT) genotype and who used sauna during pregnancy had lower n‐3 PUFA levels. In MTRR gene A66G polymorphism, cases with (AG + GG) genotype and who used sauna during pregnancy had higher PUFA and n‐6 PUFA levels.

Conclusions

Further research is required to clarify the association of FA metabolism and (MTHFR, MTRR) polymorphisms with NTDs.
A single‐step synthesis of 5,6‐dihydropyrrolo[2,1‐a]isoquinolines and evaluation of their anti‐leukemic activity
Authors: Park Hoyeong , Raikar Santosh Shivanand , Ahn Min Jeong , Kim Seong Hwan , Kim Pilho
Published: May 2024

While a pharmaceutically intriguing scaffold, 5,6‐dihydropyrrolo[2,1‐a]isoquinoline (DHPIQ), has precedently been prepared from diverse tetrahydroisoquinolines (THIQs) using elaborate conditions, convenient metal‐free methods were discovered from condensation of cyanomethylene‐THIQ (1) and α‐halo‐ketones or aldehydes (1a) to afford 15 DHPIQs (2–16) in moderate yields by employing unique reactivities of the secondary amine and α‐carbon to the nitrile of 1. Preliminary biological studies with chronic myelogenous leukemia K562 and adriamycin‐resistant K562 (K562/ADM) cells exhibited some of the DHPIQs tested were active in the both cell lines. In particular, cyclohexyl‐fused DHPIQ (10) showed GI50 values of 9.79 and 13.60 μM in K562 and K562/ADM cells, respectively. Based on the flow cytometry analysis of 10, the anti‐cancer activity could be from apoptosis‐related mechanisms. Overall, this DHPIQ scaffold may be further optimized to discover clinically meaningful anti‐leukemic agents overcoming adriamycin resistance.
Regorafenib with immunotherapy versus regorafenib alone as second‐line treatment for hepatocellular carcinoma: A multicenter real‐world study
Authors: Qiao Liang , He Wei , Wang Guoying , Chen Huanwei , Huang Fuxi , Zhang Bo , Qiu Yuxiong , Liu Shaoru , Huang Zhenkun , Yuan Yichuan , Qiu Jiliang , Yuan Yunfei , Li Binkui
Published: May 2024

Introduction

Regorafenib remains the standard and widely used second‐line strategy for advanced hepatocellular carcinoma (HCC). There is still a lack of large‐scale multicenter real‐world evidence concerning the concurrent use of regorafenib with immune checkpoint inhibitors (ICI). This study aims to evaluate whether combining regorafenib with ICI provides greater clinical benefit than regorafenib monotherapy as second‐line therapy for advanced HCC under real‐world circumstances.

Patients and Methods

The study included 208 patients from five medical facilities. One hundred forty‐three patients received regorafenib plus ICI combination therapy, while 65 patients received regorafenib monotherapy. Propensity score matching (PSM) analysis was employed.

Results

The regorafenib plus ICI group demonstrated significantly higher objective response rate (24.3% vs. 10.3%, after PSM, p = 0.030) and disease control rate (79.4% vs. 50.0%, after PSM, p < 0.001) compared to the regorafenib monotherapy group based on mRECIST criteria. Median progression‐free survival (7.9 vs. 3.2 months, after PSM, p < 0.001) and overall survival (25.6 vs. 16.4 months, p = 0.010, after PSM) were also considerably longer in the regorafenib plus ICI group. The incidence of Grades 3–4 treatment‐related adverse events (TRAEs) was marginally greater in the regorafenib plus ICI group than in the regorafenib group (23.8% vs. 20.0%, p = 0.546). Notably, there were no instances of treatment‐related mortality or emergence of new TRAEs in any treatment group.

Conclusion

The combination of regorafenib and ICI shows potential as a viable second‐line treatment for advanced HCC, exhibiting favorable efficacy while maintaining a tolerable safety profile in contrast to regorafenib monotherapy.
In situ and Operando Characterisation in the Preferential Oxidation of Carbon Monoxide over Base Metal Oxide Catalysts: A Review
Authors: Nyathi Thulani M. , Fadlalla Mohamed I. , Claeys Michael
Published: May 2024

Polymer electrolyte membrane fuel cells (PEMFCs) are the core technology of the steadily growing hydrogen (H2) economy as they can convert chemical energy, in the form of H2, to electrical energy. If the H2 is derived from (green) hydrocarbons, via steam reforming and the water‐gas‐shift reaction, then it would contain small amounts of carbon monoxide (CO, 0.5–2 %), among other gases. CO poisons the platinum‐based anode catalyst in the PEMFC, and the current recommendation is to decrease its concentration to below 0.01 % (or 100 ppm) in the H2‐rich PEMFC feed. The preferential oxidation of CO (CO‐PrOx) is a promising strategy for decreasing the CO concentration, and base metal oxide catalysts have shown great potential in this regard. However, such catalysts tend to undergo physicochemical changes that cause undesirable catalytic activity and selectivity changes. This review discusses the different base metal oxide catalysts that have been evaluated in CO‐PrOx, while paying special attention to the various in situ and operando techniques that have been used to monitor the physicochemical changes of base metal oxides during operation. We conclude the review by highlighting the recent and possible future attempts of circumventing the undesired physicochemical changes of base metal oxides during CO‐PrOx.
Continuous Flow‐By Electrochemical Reactor Design for Direct Lithium Extraction from Brines
Authors: Roggerone Clara , La Mantia Fabio , Kowal Julia , Laß‐Seyoum Asnakech
Published: May 2024

The demand for lithium is expected to increase significantly in the next few years, mainly due to the energy transition in the mobility sector. To electrify the entire global transportation system, it is necessary to have access to a wide variety of lithium deposits to ensure resource sovereignty and sufficient supply to meet demand. For this reason, much effort has recently been invested in developing technologies for direct lithium extraction (DLE) from brines. In this work, a membrane‐based continuous flow‐by reactor for the electrochemical extraction of lithium from brine with a LiMn2O4/λ‐MnO2 system has been studied. A zoned reactor was proposed in which the current density and electrode mass loading gradually decrease along with the depletion of lithium in the brine, obtaining an average electrode capacity of 80 mAh/g throughout three different reactor sections. The limiting Reynolds number was determined for the dilute lithium segment of the reactor to avoid mass transport limitations, with brine concentration equal to Li 3 mM and Na 1.3 M. A homogeneous cycle time was achieved for the three reactor zones and their associated average energy consumption was determined, ranging from 3.9 Wh/mol Li to 9.5 Wh/mol Li.
Photo‐Induced Generation of Oxygenated Quaternary Centers via EnT Enabled Singlet O2 Addition to C3‐Maleimidated Quinoxaline: A Reagent‐Less Approach
Authors: Ghosh Subhendu , Khandelia Tamanna , Mahadevan Anjali , Panigrahi Pritishree , Kumar Piyush , Mandal Raju , Boruah Deepjyoti , Venkataramani Sugumar , Patel Bhisma K.
Published: May 2024

Demonstrated here is an external photo‐sensitizer‐free (auto‐sensitized) singlet oxygen‐enabled solvent‐dependent tertiary hydroxylation and aryl‐alkyl spiro‐etherification of C3‐maleimidated quinoxalines. Such “reagent‐less” photo‐oxygenation at Csp3‐H and etherification involving Csp3‐H/Csp2‐H are unparalleled. Possibly, the highly π‐conjugated N‐H tautomer allows the substrate to get excited by irradiation, and subsequently, it attains the triplet state via ISC. This excited triplet‐state sensitized molecule then transfers its energy to a triplet‐state oxygen (3O2) generating reactive singlet oxygen (1O2) for hydroxylation and spirocyclization depending on the solvent used. In HFIP, the generated alkoxy radical accepts a proton via HAT giving hydroxylated product. In contrast, in an aprotic PhCl it underwent a radical addition at the ortho‐position of the C2 aryl to provide spiro‐ether. An unprecedented orthogonal spiro‐etherification was observed via the displacement of o‐substitutents for ortho (−OEt, −OMe, −F, −Cl, −Br) substituted substrates. The order of ipso substitution follows the trend −OMe>−OEt>−F>−H>−Cl>−Br. Both these oxygenation reactions can be carried out with nearly equal ease using direct sunlight without the requirement of any elaborate reaction setup. Demonstration of large‐scale synthesis and a few interesting transformations have also been realized. Furthermore, several insightful control experiments and quantum chemical computations were performed to unravel the mechanism.
Unusual Stability of an End‐on Superoxido Copper(II) Complex under Ambient Conditions
Authors: Campi Chiara Eleonora , Parkatzidis Kostas , Anastasaki Athina , Schindler Siegfried
Published: May 2024

Superoxido copper complexes play an important role as usually short‐lived intermediates in biology and chemistry. The unusual stability of an end‐on superoxido copper complex observed in an oxygen‐enhanced atom transfer radical polymerization (ATRP) led to a detailed mechanistic investigation of the formation of [CuII(Me6tren)(O2⋅−)]+ (Me6tren=tris(2‐dimethyl‐aminoethyl)amine) under ambient conditions. The persistence of the superoxido copper complex could be explained by a reaction cycle including the peroxido complex [(Me6tren)2CuII2(O2)]2+ together with [CuI(Me6tren)(DMSO)]+ and [CuII(Me6tren)(OH)]+ in the overall reaction.
Mass transfer and bubble hydrodynamics in stirred tank with multiple properties fluid via a CFD‐PBM method
Authors: Chen Hao , Chen Zhe , Wang Xu‐Qing , Yi Xiu‐Guang , Zhang Xi‐Bao , Luo Zheng‐Hong
Published: May 2024

The performance of a stirred bioreactor was evaluated in this study in terms of the bubble hydrodynamics and the mass transfer efficiency, using a non‐viscous Newtonian fluid of water, a viscous non‐Newtonian fluid of xanthan, and a viscous non‐Newtonian fluids of xanthan with dispersed soybean powder, respectively. The computational fluid dynamics–population balance model (CFD‐PBM) method coupled with the viscosity model and the mass transfer model is established to simulate the gas–liquid mass transfer process and bubble size distribution in the stirred bioreactor. The results demonstrate that the rheological properties of the fluid play an important role in determining the gas holdup, the mass transfer efficiency, and the bubble size distribution. Viscosity of the fluid exhibits a negative impact on gas–liquid mass transfer rate and gas holdup. Moreover, by properly adjusting the operating conditions such as the stirrer speed, it is possible to modulate the gas dispersion and mass transfer rate in the reactor.
Design of OFDM‐based two‐wire bus communication system for fire safety
Authors: Zhao Yingxin , Ou Ziwei , Xue Yuqiong , Wang Changfeng , Wu Hong
Published: May 2024

Intelligent fire safety systems place higher demands on the speed and reliability of data communication between sensors, controllers, and other devices. The two‐wire bus has become a significant trend in developing fire safety communication systems because of its low cost and simple maintenance. This paper proposes a two‐wire bus communication system for fire safety based on orthogonal frequency division multiplexing (OFDM) technology. First, we introduce the low‐voltage power line channel model and conduct relevant simulations, providing the conditions for subsequent simulation work. Then, we design the system's transmission and reception schemes, provide the parameters, and introduce each technology used. Finally, we conducted system simulations based on three different channel models, and the system performance is compared among different encoding, modulation, and channel estimation methods. The simulation results show that the system designed in this paper has superior performance compared with other systems and can meet the requirements of intelligent fire safety systems for communication speed and reliability.
Genetic insights into the role of cathepsins in cardiovascular diseases: a Mendelian randomization study
Authors: Zeng Ruiqi , Zhou Zhiyi , Liao Wanzhe , Guo Beian
Published: May 2024

Aims

This study aimed to explore the causal relationships between cathepsins and cardiovascular diseases (CVDs) by Mendelian randomization (MR) analysis.

Methods and results

Single nucleotide polymorphisms (SNPs) associated with nine cathepsin types (cathepsins B, E, F, G, H, O, S, L2, and Z) were obtained from the INTERVAL study (3301 individuals). CVDs data were acquired from the UK Biobank (coronary atherosclerosis: 14 334 cases, 346 860 controls) and a genome‐wide association study (GWAS) (myocardial infarction: 20 917 cases, 440 906 controls; myocarditis: 633 cases, 427 278 controls; chronic heart failure: 14 262 cases, 471 898 controls; angina pectoris: 30 025 cases, 440 906 controls; stable angina pectoris: 17 894 cases, 325 132 controls; unstable angina pectoris: 9481 cases, 446 987 controls; pericarditis: 1795 cases, 453 370 controls). Inverse variance weighted (IVW), MR‐Egger, weighted median methods were adopted to conduct univariable MR (UVMR), reverse MR, multivariable MR (MVMR) analyses to estimate causality. The UVMR analyses demonstrated significant causal relationships between higher cathepsin E levels and increased risk of coronary atherosclerosis [IVW: P = 0.0051, odds ratio (OR) = 1.0033, 95% confidence interval (CI) = 1.0010–1.0056] and myocardial infarction (IVW: P = 0.0097, OR = 1.0553, 95% CI = 1.0131–1.0993), while elevated cathepsin L2 levels were causally related to reduced risk of myocarditis (IVW: P = 0.0120, OR = 0.6895, 95% CI = 0.5158–0.9216) and chronic heart failure (IVW: P = 0.0134, OR = 0.9316, 95% CI = 0.8807–0.9854). Reverse MR analyses revealed that myocardial infarction increased cathepsin O levels (IVW: P = 0.0400, OR = 1.0708, 95% CI = 1.0031–1.1431). MVMR analyses treating nine cathepsins together revealed that the positive causality between cathepsin E levels and coronary atherosclerosis risk (IVW: P = 0.0390, OR = 1.0030, 95% CI = 1.0000–1.0060), and the protective effect of cathepsin L2 levels on myocarditis (IVW: P = 0.0030, OR = 0.6610, 95% CI = 0.5031–0.8676) and chronic heart failure (IVW: P = 0.0090, OR = 0.9259, 95% CI = 0.8737–0.9812) remained, as higher cathepsin O levels were found to be causally related to increased risks of myocarditis (IVW: P = 0.0030, OR = 1.6145, 95% CI = 1.1829–2.2034) and chronic heart failure (IVW: P = 0.0300, OR = 1.0779, 95% CI = 1.0070–1.1537).

Conclusions

The study highlights the causalities of cathepsin E, L2, and O on CVDs, offering insights into their roles in cardiovascular biomarkers and therapeutic targets development. Further research is required to apply these genetic findings clinically.
Echocardiographic predictors of cardiovascular outcome in heart failure with preserved ejection fraction
Authors: Wang Nelson , Rueter Phidias , Ng Melvin , Chandramohan Sashiruben , Hibbert Thomas , O'Sullivan John F. , Kaye David , Lal Sean
Published: May 2024

Aims

The optimal echocardiographic predictors of cardiovascular outcome in heart failure (HF) with preserved ejection fraction (HFpEF) are unknown. We aimed to identify independent echocardiographic predictors of cardiovascular outcome in patients with HFpEF.

Methods and results

Systematic literature search of three electronic databases was conducted from date of inception until November 2022. Hazard ratios (HRs) and their 95% confidence intervals (CIs) for echocardiographic variables from multivariate prediction models for the composite primary endpoint of cardiovascular death and HF hospitalization were pooled using a random effects meta‐analysis. Specific subgroup analyses were conducted for studies that enrolled patients with acute versus chronic HF, and for those studies that included E/e′, pulmonary artery systolic pressure (PASP), renal function, natriuretic peptides and diuretic use in multivariate models. Forty‐six studies totalling 20 056 patients with HFpEF were included. Three echocardiographic parameters emerged as independent predictors in all subgroup analyses: decreased left ventricular (LV) global longitudinal strain (HR 1.24, 95% CI 1.10–1.39 per 5% decrease), decreased left atrial (LA) reservoir strain (HR 1.30, 95% CI 1.13–1.1.50 per 5% decrease) and lower tricuspid annular plane systolic excursion (TAPSE) to PASP ratio (HR 1.17, 95% CI 1.07–1.25 per 0.1 unit decrease). Other independent echocardiographic predictors of the primary endpoint were a higher E/e′, moderate to severe tricuspid regurgitation, LV mass index and LA ejection fraction, although these variables were less robust.

Conclusions

Impaired LV global longitudinal strain, lower LA reservoir strain and lower TAPSE/PASP ratio predict cardiovascular death and HF hospitalization in HFpEF and are independent of filling pressures, clinical characteristics and natriuretic peptides. These echocardiographic parameters reflect key functional changes in HFpEF, and should be incorporated in future prospective risk prediction models.
Effects of rainfall patterns, vegetation cover types and antecedent soil moisture on run‐off and soil loss of typical Luvisol in southern China
Authors: Wang Fei , Tian Pei , Guo Wenzhao , Chen Lin , Gong Yuwei , Ping Yaodong
Published: May 2024

Identifying the effect of precipitation, vegetation cover and underlying surface conditions on run‐off and soil loss is essential for understanding the mechanism of water erosion. The study site is located in the Shiqiaopu watershed of Hubei Province, China. The long‐term (2017–2021) monitoring data for this study included rainfall characteristics, antecedent soil moisture, run‐off and soil loss in four run‐off plots with four vegetation cover types (tea garden, soybean and rape, peanut and rape, and vetiver zizanioides). K‐means clustering and discriminant analysis were used to classify rainfall patterns. The improved redundancy analysis was used to quantitatively explore the relative importance of rainfall characteristics, vegetation cover and antecedent soil moisture to run‐off and soil loss. The results showed that the rainfall patterns were mainly divided into three categories: A (medium duration, small rainfall, medium rain intensity, high frequency), B (long duration, large rainfall, light rain intensity, low frequency) and C (short duration, medium rainfall, heavy rain intensity, medium frequency). The average run‐off coefficient, run‐off depth of different rainfall patterns were C > B > A, and the cumulative run‐off depth and soil loss under the A rainfall pattern were the largest. For the run‐off plots with four vegetation cover types, vetiver zizanioides had the best effect on run‐off and sediment reduction, while peanut and rape had the worst effect. The driving factor that contributed the most to the run‐off depth was vegetation cover (19.36%), and rainfall characteristics explained the most to the soil loss (11.65%). We also found that although antecedent soil moisture had a small explanation rate for soil loss, it was significantly correlated with the run‐off depth under the vegetation cover of the tea garden. Therefore, regional soil erosion should be combined with the importance of driving factors to take comprehensive control measures.
Investigating the potential for students to contribute to climate data rescue: Introducing the Climate Data Rescue Africa project (CliDaR‐Africa)
Authors: Noone S. , D'Arcy C. , Donegan S. , Durkan W. , Essel B. , Healion K. , Hersbach H. , Madden S. , Marshall J. , McConnell L. , Mensah I. , Scroxton N. , Thiesen S. , Thorne P.
Published: May 2024

The majority of available climate data in global digital archives consist of data only from the 1940s or 1950s onwards, and many of these series have gaps and/or are available for only a subset of the variables which were actually observed. However, there exist billions of historical weather observations from the 1700s, 1800s, and early 1900s that are still in hard‐copy form and are at risk of being lost forever due to deterioration. An assessment of changes in climate extremes in several IPCC regions was not possible in IPCC AR6 WGI owing, in many cases, to the lack of available data. One such region is Africa, where the climate impact research and the ability to predict climate change impacts are hindered by the paucity of access to consistent good‐quality historical observational data. The aim of this innovative project was to use classroom‐based participatory learning to help transcribe some of the many meteorological observations from Africa that are thus far unavailable to researchers. This project transcribed quickly and effectively station series by enrolling the help of second‐year undergraduate students at Maynooth University in Ireland. The newly digitized African data will increase the temporal and spatial coverage of data in this important data‐sparse region. Students gained new skills while helping the global scientific community unearth new insight into past African climate. The project managed to transcribe 79 months of data at Andapa in Madagascar and 56 months of data for Macenta in Guinea. The digitized data will be openly and freely shared with the scientific and wider community via the Pangaea data repository, the C3S Climate Data Store, and the National Oceanic and Atmospheric Administration's (NOAA) National Centers for Environmental Information (NCEI) data centre in the US. The project model has the potential for a broader roll‐out to other educational contexts and there is no shortage of data to be rescued. This paper provides details of the project, and all supporting information such as project guidelines and templates to enable other organizations to instigate similar programs.
The impact of natural vegetation restoration on surface soil moisture of secondary forests and shrubs in the karst region of southwest China
Authors: Chen Jia , Zhang Lin , Cai Xianli , Luo Weijun , Lyu Yina , Cheng Anyun , Wang Shijie
Published: May 2024

Soil moisture is crucial to vegetation restoration in karst areas, and climate factors and vegetation restoration are key factors affecting changes in soil moisture. However, there is still much controversy over the long‐term changes in soil moisture during vegetation restoration. In order to reveal the changes in soil moisture during vegetation restoration, we conducted long‐term positioning monitoring of soil moisture at 0–10 and 10–20 cm on secondary forests sample plot (SF, tree land) and shrubs sample plot (SH, shrub land) in karst areas from 2013 to 2020. The results showed that the aboveground biomass of SF and SH increased by 50% and 240%, respectively, and the soil moisture of the SF and SH showed an increasing trend. When shrubs are restored to trees in karst areas, the soil moisture becomes more stable. However, the correlation coefficients (R2) between the annual rainfall and the annual average soil moisture of SF and SH are 0.84 and 0.55, respectively, indicating that soil moistures in tree land are more affected by rainfall. The soil moisture of shrubs and trees are relatively low during the months of alternating rainy and dry seasons. Rainfall has a very significant impact on the soil moisture of tree land, while air temperature and wind speed have a significant impact on the soil moisture of tree land, but the soil moistures of shrub land are very significantly affected by rainfall and relative humidity. Therefore, during the process of vegetation restoration from shrubs to trees, the main meteorological factors that affect soil moisture changes will change. The results are important for understanding the hydrological processes in the ecological restoration process of different vegetation types in karst areas.
A sweet burden? The effect of bride prices on parents' health
Authors: Chen Yuan , Ding Yue , Huang Jingwei , Li Xun , Wu Kaidi
Published: May 2024

The bride price, as an informal institution originated from traditional culture, is pervasive in many areas of the developing world in a form of a payment from the family of the groom to that of the bride at marriage. We study the effects of bride price on parents' health in China. Using information on bride price payment and various health measures from the China Health and Retirement Longitudinal Study, we find that the bride price significantly reduces self‐reported health among the grooms' parents after addressing the endogeneity issue with average sex ratio within a family computed as an instrumental variable. The reductions are heterogenous across urban and rural areas. Mechanism analysis suggests the negative health outcomes are driven by family debt, heavier psychological stress and longer work hours caused by bride price payments.
Enhanced channel prediction in large‐scale 5G MIMO‐OFDM systems using pyramidal dilation attention convolutional neural network
Authors: Rathish Chirakkal Radhakrishnan , Manojkumar Balakrishnan , Thanga Mariappan Lakshmanaperumal , Ashok Panchapakesan , Arun Kumar Udayakumar , Balan Krishnan
Published: May 2024

In order to enhance communication while minimizing complexity in 5G and beyond, MIMO‐OFDM systems need accurate channel prediction. In order to enhance channel prediction, decrease Error Vector Magnitude, Peak Power, and Adjacent Channel Leakage Ratio, this study employs the Pyramidal Dilation Attention Convolutional Neural Network (PDACNN). Simplified clipping with filtering (SCF) reduces PAPR data, and this technique employs a PDACNN trained with the reduced data. By combining attention techniques with pyramidal dilated convolutions, the suggested PDACNN architecture is able to extract OFDM channel parameters across several scales. Attention approaches enhance channel prediction by allowing the model to dynamically concentrate on essential information. The primary objective is to make use of the network's ability to comprehend intricate spatial–temporal connections in OFDM channel data. The goal of these techniques is to make channel forecasts more accurate and resilient while decreasing concerns about EVM, Peak Power, and ACLR. To confirm the effectiveness of the suggested CP‐LSMIMO‐OFDM‐PDACNN, we measure its spectral efficiency, peak‐to‐average power ratio, bit error rate (BER), signal‐to‐noise ratio (SNR), and throughput. Throughput gains of 23.76%, 30.45%, and 18.97% are achieved via CP‐LSMIMO‐OFDM‐PDACNN, while bit error rates of 20.67%, 12.78%, and 19.56% are reduced. PAPRs of 21.66%, 23.09%, and 25.11% are also decreased.
An artificial intelligence‐based dental semantic search engine as a reliable tool for dental students and educators
Authors: Prakash Krishna , Prakash Ram
Published: May 2024

Purpose/objectives

This study proposes the utilization of a Natural Language Processing tool to create a semantic search engine for dental education while addressing the increasing concerns of accuracy, bias, and hallucination in outputs generated by AI tools. The paper focuses on developing and evaluating DentQA, a specialized question‐answering tool that makes it easy for students to seek information to access information located in handouts or study material distributed by an institution.

Methods

DentQA is structured upon the GPT3.5 language model, utilizing prompt engineering to extract information from external dental documents that experts have verified. Evaluation involves non‐human metrics (BLEU scores) and human metrics for the tool's performance, relevance, accuracy, and functionality.

Results

Non‐human metrics confirm DentQA's linguistic proficiency, achieving a Unigram BLEU score of 0.85. Human metrics reveal DentQA's superiority over GPT3.5 in terms of accuracy (p = 0.00004) and absence of hallucination (p = 0.026). Additional metrics confirmed consistent performance across different question types (X2 (4, N = 200) = 13.0378, p = 0.012). User satisfaction and performance metrics support DentQA's usability and effectiveness, with a response time of 3.5 s and over 70% satisfaction across all evaluated parameters.

Conclusions

The study advocates using a semantic search engine in dental education, mitigating concerns of misinformation and hallucination. By outlining the workflow and the utilization of open‐source tools and methods, the study encourages the utilization of similar tools for dental education while underscoring the importance of customizing AI models for dentistry. Further optimizations, testing, and utilization of recent advances can contribute to dental education significantly.
A prospective study on the histological evaluation of type 1 autoimmune pancreatitis using endoscopic ultrasound‐guided fine needle biopsy with a 19‐gauge Franseen needle
Authors: Ishikawa Takuya , Yamao Kentaro , Mizutani Yasuyuki , Iida Tadashi , Uetsuki Kota , Shimoyama Yoshie , Nakamura Masanao , Furukawa Kazuhiro , Yamamura Takeshi , Kawashima Hiroki
Published: May 2024

Background/Purpose

To assess the diagnostic efficacy and safety of endoscopic ultrasound‐guided fine needle biopsy (EUS‐FNB) using a 19‐gauge Franseen needle for autoimmune pancreatitis (AIP).

Methods

Twenty patients suspected of having type 1 AIP were prospectively enrolled and underwent EUS‐FNB with a 19‐gauge Franseen needle. Their data were compared with those of historical controls: a total of 29 type 1 AIP patients had EUS‐FNB with a 22‐gauge Franseen needle.

Results

Specimens suitable for histological evaluation were obtained from 19 of the 20 patients (95%), and the median total tissue area was 11.9 mm2. The histological diagnosis rate of AIP was 65% (95% CI: 43.2%–82%). Adverse events were observed in three patients (15%), and a switch to 22‐gauge needles occurred during transduodenal puncture in two patients. Compared to those punctured with 22‐gauge needles, patients punctured with 19‐gauge needles had greater prevalence of each characteristic feature of lymphoplasmacytic sclerosing pancreatitis, but the difference was not statistically significant.

Conclusions

EUS‐FNB using a 19‐gauge Franseen needle demonstrated favorable performance for the histological diagnosis of AIP and allowed for large tissue samples, potentially facilitating pathological diagnosis. However, during transduodenal puncture, maneuverability is reduced; therefore, the needle may need to be selected according to the puncture site.
Evaluation and novel treatment in a case of refractory small bowel‐small bowel intussusception
Authors: Rabinowitz Danielle G. , Rufo Paul A.
Published: May 2024

Small bowel into small bowel intussusception can present with symptoms similar to those observed in patients with more common small bowel into large bowel intussusception. In most cases, intussusceptions isolated to the small bowel are self‐limited and less likely to result in bowel ischemia. Nonetheless, any patient with recurrent intussusception should be evaluated to assess location and for the presence of a pathologic lead point. We report a patient with recurrent small bowel into small bowel intussusception who underwent a comprehensive evaluation that revealed lymphoid hyperplasia in the absence of a pathologic lead point. His symptoms resolved after a dose of oral dexamethasone.
Microsurgical reconstruction for head and neck in patients with end‐stage renal disease undergoing dialysis
Authors: Hung Chen‐Ting , Wu Meng‐Si , Wang Chien‐Hsing , Cheng Li‐Fu , Chou Yu‐Fu , Lee Chia‐Fone , Chen Peir‐Rong , Lee Jiunn‐Tat
Published: May 2024

Introduction

Free flap transfer for head and neck defects has gained worldwide acceptance. Because flap failure is a devastating outcome, studies have attempted to identify risk factors—including renal failure. We sought to determine whether end‐stage renal disease (ESRD) patients undergoing dialysis are at increased risk of flap failure following microsurgical head and neck reconstruction.

Patients and Methods

The study's participants were patients who underwent free flap reconstruction in the head and neck region at Hualien Tzu Chi Hospital between January 2010 and December 2019. We used the National Health Insurance “Specific Diagnosis and Treatment Code” to identify patients undergoing dialysis; these patients comprised the dialysis group, whose members were matched to a non‐dialysis group for age and gender. The dependent variables were flap survival rate, take‐back rate, and flap failure risk between the dialysis and non‐dialysis groups.

Results

We included 154 patients in the dialysis (n = 14) and non‐dialysis (n = 140) groups. The groups were similar in terms of age and most comorbidities, except diabetes mellitus, hypertension, and coronary artery disease, which were more prevalent in the dialysis group. The dialysis and non‐dialysis groups had similar flap survival rates (100% vs. 92.9%; p = .600). Twenty‐three patients underwent take‐back surgery, most in the non‐dialysis group (14.3% vs. 15.0%; p = 1.000). Patients in the dialysis group were more likely to have prolonged intensive care unit stays; however, dialysis alone did not predict flap failure (OR: 0.83; p = .864).

Conclusion

This study found no significant differences in free flap survival and take‐back rates between patients with and without dialysis. Dialysis did not increase the risk of flap failure following microsurgical head and neck reconstruction in this study; however, prospective, randomized controlled trials are needed.
Anderson localization for block Jacobi operators with quasi‐periodic meromorphic potential
Authors: Zhang Xiaojian
Published: May 2024

In this paper, we study block Jacobi operators on
with quasi‐periodic meromorphic potential. We prove the nonperturbative Anderson localization for such operators in the large coupling regime.
Revision Cochlear Implantation With Device Manufacturer Conversion: Surgical Outcomes and Speech Perception Performance
Authors: Yaar‐Soffer Yifat , Shapira Yisgav , Sagiv Doron , Yakir Ziva , Wolfovitz Amit , Henkin Yael
Published: May 2024

Objective

Describe the clinical profile of revision cochlear implantation (RCI) cases involving device manufacturer conversion (RCImc+), compare them to cases without manufacturer conversion (RCImc−), and classify the reasons for manufacturer conversion (MC).

Study Design

Retrospective case review.

Setting

Tertiary academic center.

Methods

Data on demographics, RCI indications, medical background, surgical details, and the reasons for MC were collected for all RCIs from 1989 to 2020. Post‐RCI speech perception performance was categorized as unchanged, improved, or declined, according to clinically based criteria.

Results

Of 185 RCIs, 39 (21%) involved MC, mostly in pediatric patients (67%). The leading RCImc+ indications were device‐related (59%) and medical (31%) failures. Initial implant manufacturers were Advanced Bionics (49%), Cochlear (25.5%), or Medel (25.5%). Most MC reasons were patient‐driven (64%) versus CI team recommendations (36%). The RCImc+ group demonstrated a 3‐fold higher rate of medical indications than RCImc− (31% vs 11.5%, P = .007). The time interval from symptom onset to RCI was longer in RCImc+ (43 vs 20.3 months, P = .001), and the rate of multiple revisions in the same ear was higher (25.6% vs 8.2%, P = .009). Complete reinsertion rates were high in both RCImc+ and RCImc− (94.8% vs 94.5%, P = 1) without any complications. Speech perception improved or remained unchanged in most (84%) cases, with no significant difference between the groups (P = .183).

Conclusion

This retrospective study showed that RCI involving MC is safe and beneficial. Although RCImc+ patients exhibited distinct clinical characteristics, MC did not impact surgical or speech perception outcomes. This provides evidence‐based data to support informed decision‐making by CI teams and patients.
Enhanced thermo‐mechanical properties of carbon fiber reinforced thermoresistant polymer, a blend of di‐functional epoxy bisphenol A and a tri‐functional epoxy Tactix 742
Authors: Anurangi Jayani , Jayalath Sandaruwan , Rani Senevirathna Sandhya , Herath Madhubhashitha , Epaarachchi Jayantha
Published: May 2024

Fiber reinforced polymer composite structures are particularly vulnerable to high temperatures as their strength drastically reduces under elevated temperature conditions. Therefore, it is important to improve the thermal stability of such composite structures to expand their potential range of applications. In this study, the effect of mixing two epoxy monomers, DGEBA and Tactix 742, which are di‐ and tri‐functional, respectively, on the thermal stability of their composites is investigated. The thermo‐mechanical analysis of these composites revealed that the glass transition temperature rose from 123 to 229°C when Tactix 742 is increased from 25% to 75%. The thermal resistance property is attributed to a three‐dimensional crosslink network which is initiated by tri‐functional Tactix 742. However, the higher percentage of Tactix led to a reduction in strength, possibly due to decreased crystallinity and formed amorphous phase material. Subsequently, a tensile strength model was employed to assess the performance at elevated temperatures. It was shown that a matrix with a mix of di‐ and tri‐functional monomers is highly promising for manufacturing thermoresistant polymeric composites with robust mechanical properties, thereby expanding their potential applications across various engineering fields such as civil and construction industries.

Highlights

A thermoresistant matrix by blending di‐ and tri‐functional epoxy monomers.

Improved thermo‐mechanical properties and increased glass transition temperature of fiber reinforced composites.

Mechanical performance of carbon fiber reinforced composites at elevated temperatures.

Validated a model to estimate the tensile strengths of the composites at elevated temperatures.
Clearing the light path: Proteoglycans and their important roles in the lens and cornea
Authors: Stepp Mary Ann , Menko A. Sue
Published: May 2024

Some of the earliest studies of glycans were performed on mammalian corneas and lenses with many of the key concepts we currently recognize as being fundamental to our understanding of basic cell biology arising from these studies. Proteoglycans and their glycosaminoglycan (GAG) side chains are essential components of the extracellular matrix (ECM) of the lens capsule. They also are present in the anterior corneal epithelial basement membrane and the posterior (Decemet's) basement membrane, and they organize collagen fiber diameters and spacing in the corneal stroma to maintain stromal clarity. Studies using genetically engineered mice and characterization of spontaneously arising mutations in genes controlling proteoglycan synthesis have generated new insight into the roles played by proteoglycans in signal transduction. We now know that proteoglycans and GAGs can regulate cell signaling and the maintenance of avascularity and immune privilege that are hallmarks of these tissues. In addition, proteoglycan‐rich matrices provide the pathways for immune cells to populate the surface of the lens as a response to corneal wounding and in a model of experimental autoimmune uveitis. Here we describe what is known about proteoglycans and GAGs in the cornea and lens. This knowledge has begun to provide promising leads into new proteoglycan‐based treatments aimed at restoring and maintaining homeostasis in the cornea. Future studies are needed to determine how these new drugs impact the recruitment of immune cells to the lens for functions in restoring/maintaining homeostasis in the eye.
Two new user‐friendly methods to assess pharmacometric parameter identifiability on categorical and continuous scales
Authors: van Noort Martijn , Ruppert Martijn
Published: May 2024

Parameter identifiability methods assess whether the parameters of a model are uniquely determined by the observations. While the success of a model fit can provide some information on this, it can be valuable to determine identifiability before any fit has been attempted, or to separate identifiability from other issues. Two concepts that lean themselves well for identifiability analysis and have been underutilized are the sensitivity matrix (SM) and the Fisher information matrix (FIM). This paper presents two newly developed methods, one based on the SM and one based on the FIM. Both methods can assess local identifiability for a wide set of models, can be used with limited effort, and are freely available. The methods require the proposed model in the form of a set of differential equations, the parameter values, and the study design as input. They can be used a priori, as they do not need observed values or a successful model fit. Traditional methods provide a single categorical (yes/no) answer to the question of identifiability. In many cases, this is not very informative, and identifiability depends on study design (e.g., dose levels or observation times) and parameter values. Indicators on a continuous scale characterizing the level of identifiability would provide more detailed and relevant information, for example, to guide model development. Our two methods provide both categorical and continuous indicators. Both methods indicate which parameter combinations are difficult to identify by calculating the directions in parameter space that are least identifiable. The methods were validated with an example problem.
Arctic amplification‐induced intensification of planetary wave modulational instability: A simplified theory of enhanced large‐scale waviness
Authors: Luo Dehai , Luo Binhe , Zhang Wenqi , Zhuo Wenqin , Simmonds Ian , Yao Yao
Published: May 2024

In the mid–high latitude atmosphere, the instability of planetary waves characterizes enhanced planetary wave activity or amplified large‐scale waviness leading to increased regional weather extremes. In this paper, a nonlinear Schrödinger equation is derived to describe the evolution of planetary waves. Then the consequences of Arctic amplification (AA)‐induced meridional background potential vorticity (PVy) changes on the modulational instability of planetary waves are examined. It is found that the modulational instability of uniform planetary wave trains mainly results from the presence of high‐order dispersion and nonlinearity, even though such an instability depends on the amplitude, vertical structure and zonal wavenumber of uniform planetary waves and the atmospheric stratification. Because the nonlinearity and high‐order dispersion depend on the magnitude of PVy, the modulational instability of planetary waves is significantly influenced by the variation of PVy associated with AA. It is also revealed that stronger modulational instability of planetary waves tends to occur in the smaller PVy region or in higher latitudes due to both stronger nonlinearity and weaker high‐order dispersion for fixed background and planetary wave parameters, which is conducive to more intense large‐scale waviness. However, because AA can reduce PVy in the mid–high latitudes mainly in the lower troposphere via reductions of winter zonal winds and meridional temperature gradients, the reduced PVy under AA can significantly enhance the modulational instability. Thus, the role of AA is to amplify planetary wave activity in mid–high latitudes through strengthening the modulational instability of planetary waves due to reduced PVy, which further enhances large‐scale waviness.
Factors influencing subseasonal predictability of northern Eurasian cold spells
Authors: Erner Irene , Karpechko Alexey
Published: May 2024

Cold‐air outbreaks have significant impacts on human health, energy consumption, agriculture, and overall well‐being. This study aims to evaluate the effectiveness of Subseasonal‐to‐Seasonal (S2S) models in predicting cold conditions over northern Eurasia, defined here as the lower tercile of weekly mean 2‐metre temperature anomalies. To assess the predictability of these events we use ensemble hindcasts from five prediction systems from the S2S database. Our analysis focuses on identifying the conditions under which the models confidently predict cold temperatures with a high (>0.5) probability 3–4 weeks ahead, which potentially can represent windows of forecast opportunity. We compare the group of forecasts that correctly predicted the events to the group that forecasted events that did not occur in practice (false alarms). Most of the confident forecasts of cold spells, both correct and false alarms, have cold anomalies already in the initial conditions, often in conjunction with either a negative phase of the North Atlantic Oscillation, or Scandinavian Blocking. We find that S2S models tend to overpredict cold temperatures, with false alarms occurring more likely when the forecasts are initialized during a weak polar vortex. Furthermore, most of the confident false alarms receive the signal from the stratosphere rather than following internal tropospheric dynamics. False alarms initialized during the weak polar vortex conditions are more common when the vortex is in a recovery stage and, subsequently, the downward ‐propagating signal is short‐lived in the troposphere. The analysis of forecasts during different Madden–Julian Oscillation (MJO) phases shows that nearly half of all confident correct cold‐temperature forecasts are initialized during an active MJO in phases 6–8. On the other hand, most false alarms occur during phase 3, which we suggest is due to the presence of the Scandinavian Blocking regime in the initial conditions for this phase.