基于并行BICGSTAB的不可压流场计算方法

不可压缩流动广泛存在于日常生活及工程应用之中,随着数值模拟规模不断扩大,CFD算法越来越重视并行计算。该文采用SIMPLE算法对不可压流场进行求解,为求解算法中的大型稀疏矩阵,该文发展一套基于MPI框架的并行BICGSTAB矩阵求解方法。最后采用定常顶盖驱动流算例及非定常圆柱绕流算例验证并行算法的可行性及准确性。

基于高光谱技术的枇杷总酚含量无损检测

为评估高光谱成像技术(hyperspectral imaging,HSI)用于冷藏过程中枇杷总酚含量(totally phenolic content,TPC)预测的可能性,在可见光/近红外波段(363~1026 nm)采集115个枇杷样本高光谱信息,通过福林酚法对样本TPC进行测定。再采用蒙特卡洛算法对异常样本进行剔除,竞争性自适应加权算法(competitive adaptive reweighted sampling,CARS)对特征波长进行提取,分别建立枇杷TPC的非线性迭代偏最小二乘法(nonlinear iterative partial least square,NIPALS)预测模型和简单偏最小二乘法(simple partial least square,SIMPLS)预测模型并进行验证。结果显示,CARS共提取到特征波段47条,占波长总数7.62%;在最佳主成分数时,CARS-NIPALS与CARS-SIMPLS的建模集决定系数R^(2)_(c)分别为0.9221、0.9160,预测集决定系数R^(2)_(p)分别为0.8166、0.8128,NIPALS与SIMPLS两种算法表现相似,HSI能对冷藏过程中的枇杷TPC进行有效预测。

Parent-offspring relationship recognition based on SSR and mtDNA confirmed resource supplement effect of Fenneropenaeus chinensis release

The resource of Fenneropenaeus chinensis has declined sharply due to excessive fishing intensity,ecological changes and diseases.In order to supplement the fishing yield and restore resources of F.chinensis,the relevant authorities have carried out the activities of stock enhancement and releasing.It can increase biomass and recover resources.However,compared with increasing biomass,there were still few reports on its effect on the recovery of resources.Resource recovery is a process related to whether the released individuals can form a reproductive population.Up to now,there has been a lack of evidence whether the released F.chinensis can complete the entire life history,and form reproduction population.In this study,gravid female shrimp after spawning migration were captured from coastal waters of Haiyang,Qingdao,and Yellow Sea.After identifying parentage relationships using simple sequence repeat(SSR)and mtDNA haplotype,it was finally confirmed that there were eight released individuals in the recapture samples.It was confirmed for the first time that at least part of the released F.chinensis can complete overwintering and reproductive migration,and maintain the migration habits as their wild counterparts.Therefore,we infered that the released shrimp can reproduce under natural conditions,these F.chinensis can form reproductive populations theoretically if without human intervention.These results indicated that enhancenment and release activities have a positive effect on resource recovery.

Identification of time-varying system and energy-based optimization of adaptive control in seismically excited structure

The combination of structural health monitoring and vibration control is of great importance to provide components of smart structures.While synthetic algorithms have been proposed,adaptive control that is compatible with changing conditions still needs to be used,and time-varying systems are required to be simultaneously estimated with the application of adaptive control.In this research,the identification of structural time-varying dynamic characteristics and optimized simple adaptive control are integrated.First,reduced variations of physical parameters are estimated online using the multiple forgetting factor recursive least squares(MFRLS)method.Then,the energy from the structural vibration is simultaneously specified to optimize the control force with the identified parameters to be operational.Optimization is also performed based on the probability density function of the energy under the seismic excitation at any time.Finally,the optimal control force is obtained by the simple adaptive control(SAC)algorithm and energy coefficient.A numerical example and benchmark structure are employed to investigate the efficiency of the proposed approach.The simulation results revealed the effectiveness of the integrated online identification and optimal adaptive control in systems.

Main focus of parents of children with attention deficit hyperactivity disorder and the effectiveness of early clinical screening

BACKGROUND Attention deficit hyperactivity disorder(ADHD)is a common mental and behavioral disorder among children.AIM To explore the focus of attention deficit hyperactivity disorder parents and the effectiveness of early clinical screening METHODS This study found that the main directions of parents seeking medical help were short attention time for children under 7 years old(16.6%)and poor academic performance for children over 7 years old(12.1%).We employed a two-stage experiment to diagnose ADHD.Among the 5683 children evaluated from 2018 to 2021,360 met the DSM-5 criteria.Those diagnosed with ADHD underwent assessments for letter,number,and figure attention.Following the exclusion of ADHD-H diagnoses,the detection rate rose to 96.0%,with 310 out of 323 cases identified.RESULTS This study yielded insights into the primary concerns of parents regarding their children's symptoms and validated the efficacy of a straightforward diagnostic test,offering valuable guidance for directing ADHD treatment,facilitating early detection,and enabling timely intervention.Our research delved into the predominant worries of parents across various age groups.Furthermore,we showcased the precision of the simple exclusion experiment in discerning between ADHD-I and ADHD-C in children.CONCLUSION Our study will help diagnose and guide future treatment directions for ADHD.

Simulated Indonesian Throughflow in Makassar Strait across the SODA3 products

The Indonesian Throughflow(ITF), which connects the tropical Pacific and Indian oceans, plays important roles in the inter-ocean water exchange and regional or even global climate variability. The Makassar Strait is the main inflow passage of the ITF, carrying about 77% of the total ITF volume transport. In this study, we analyze the simulated ITF in the Makassar Strait in the Simple Ocean Data Assimilation version 3(SODA3) datasets. A total of nine ensemble members of the SODA3 datasets, of which are driven by different surface forcings and bulk formulas, and with or without data assimilation, are used in this study. The annual mean water transports(i.e.,volume, heat and freshwater) are related to the combination of surface forcing and bulk formula, as well as whether data assimilation is employed. The phases of the seasonal and interannual variability in water transports cross the Makassar Strait, are basically consistent with each other among the SODA3 ensemble members. The interannual variability in Makassar Strait volume and heat transports are significantly correlated with El Ni?oSouthern Oscillation(ENSO) at time lags of-6 to 7 months. There is no statistically significant correlation between the freshwater transport and the ENSO. The Makassar Strait water transports are not significantly correlated with the Indian Ocean Dipole(IOD), which may attribute to model deficiency in simulating the propagation of semiannual Kelvin waves from the Indian Ocean to the Makassar Strait.

Comparing pharmacotherapy and transcranial magnetic stimulation for the treatment of anxiety and depression after aortic dissection surgery

BACKGROUND Aortic coarctation is a potentially fatal condition that is primarily treated surgically.Despite successful procedures,patients frequently experience postoperative anxiety and depression,which can hinder recovery and worsen outcomes.Pharmacological interventions,such as 5-hydroxytryptamine(5-HT)and norepinephrine reuptake inhibitors,are commonly prescribed;however,their efficacy alone or in combination with non-invasive brain stimulation techniques,such as repetitive transcranial magnetic stimulation(TMS),remains unclear.AIM To assess the effect of medications and TMS on post-aortic surgery anxiety and depression.METHODS We analyzed the outcomes of 151 patients with anxiety and depression who were hospitalized for aortic dissection between January 2020 and September 2022.Using the random number table method,75 and 76 patients were allocated to the normal control and study groups,respectively.All the patients were treated using routine procedures.The control group was administered anti-anxiety and antidepression drugs,whereas the study group was treated with TMS in addition to these medications.The patients in both groups showed improvement after two courses of treatment.The Hamilton Anxiety Scale(HAMA)and the Hamilton Depression Scale(HAMD)were used to assess anxiety and depression,respectively.The serum levels of brain-derived neurotrophic factor(BDNF)and 5-HT were determined using enzyme-linked immunosorbent assay.The Pittsburgh Sleep Quality Index(PSQI)was used to estimate sleep quality,and the Repeatable Battery for the Assessment of Neuropsychological Status(RBANS)was used to assess cognitive function.RESULTS The HAMD and HAMA scores reduced in 2 groups,with the study group achieving a lower level than control(P<0.05).In the control group,43 patients recovered,17 showed improvement,and 15 were deemed invalid.In the study group,52 recovered,20 improved,and four were invalid.The efficacy rate in study group was 94.74%compared to 80.00%in control(P<0.05).The BDNF and 5-HT levels increased in both groups,with higher levels observed in the experimental group(P<0.05).Moreover,the PSQI scores decreased in 2 groups,but were lower in the intervention group than control(P<0.05).The scores of the RBANS items increased,with the study group scoring higher than control(P<0.05).CONCLUSION Combining anti-anxiety and anti-depressive drugs with repetitive TMS after aortic surgery may enhance mood and treatment outcomes,offering a promising clinical approach.

Clinical Epidemiology and Surgical Treatment of Spontaneous Perforations of the Terminal Ileum: A Multicentre Study in Cameroon

Background: Perforations of the terminal ileum are a frequent clinical situation and a therapeutic challenge. Surgical treatment is controversial. Several surgical modalities have been proposed and postoperative morbidity and mortality remain high. The aim of this study was to review our experience in the surgical management of perforations of the terminal ileum. Patients and methods: This is a descriptive cross-sectional study with retrospective data collection from January 1, 2017 to December 31, 2021, in five hospitals in Cameroon. Patients’ demographic, clinical presentation, surgical findings and 30-days postoperative outcomes data were collected. Results: We collected 34 files. The sex ratio was 1.4 and the average age was 20.28 years. The average consultation time was 9.1 days. Abdominal pain was present in all our patients. Peritoneal irritation was present in 46 cases (88.5%). The mean time to treatment after admission was 17.5 hours. The perforation was unique in 40 cases (76.9%) and located between 6 and 10 cm from the ileocecal valve in 29 cases (55.8%). Typhoid was the most suspected etiology intraoperatively in 38 cases (73.1%). A simple suture was performed in 18 patients (34.6%), resection with anastomosis in 11 patients (21.2%) and an ileostomy in 5 patients (9.6%). The average length of hospitalization was 21.74 days. Postoperative morbidity and mortality were 32.7% and 17.3% respectively. Conclusion: Perforations of the terminal ileum are common and affect young people. Surgical procedures are varied. Reducing consultation and care times and respecting treatment principles could improve postoperative morbidity and mortality, which remain high.

YOLO在口罩检测中的应用与研究

随着公共卫生安全意识的提升,口罩检测尤为重要。本研究探讨了YOLO算法在口罩检测应用中的有效性。首先,梳理了YOLO的核心原理与演进脉络,为算法的优化提供理论基础。其次,分析了口罩检测的紧迫性以及现有方法的局限性。在此基础上,本文介绍了数据集准备、实验环境配置,并对YOLO检测模型进行了优化,以提高口罩检测的准确率和实时性。实验结果表明,优化后的YOLO模型在口罩检测任务上展现出卓越的性能,提升了检测的效率。本研究不仅推动了计算机视觉领域的技术应用,也对当前和未来公共卫生管理实践具有重要意义。

Exploring Ester Prodrugs: A Comprehensive Review of Approaches, Applications, and Methods

The review provides an overview of the approaches, applications, and methods for ester prodrugs. Ester prodrugs are pharmacologically inactive compounds in their original form but become active drugs on biotransformation within the body, which offers advantages concerning the solubility, stability, and targeted delivery of the active drug. Several approaches of ester prodrugs have been reviewed in this review, including simple ester prodrugs, amino acid ester prodrugs, sugar ester prodrugs, lipid ester prodrugs, and polymeric ester prodrugs. This review incorporates in vitro and in vivo methods as well as the characterization of physical and chemical properties for ester prodrugs, cell culture systems, enzymatic assays, and animal models—all of these having a very important bearing on the evaluation of stability, bioavailability, and efficacy for ester prodrugs. While the benefits of using ester prodrugs are significant, there are also disadvantages like instability, poor or variable enzymatic hydrolysis, and toxicity from released promoieties or by-products. This review discusses solutions to the various limitations that include enhancing stability with ionizable promoieties and using physiologically-based pharmacokinetic modeling. The review also highlights the application of ester prodrugs in neurological disorders, such as Parkinson’s disease, and the ongoing efforts to address the critical limitations in treatment efficacy. Future prodrug strategies are poised to advance significantly by harnessing diverse transport mechanisms across the blood-brain barrier and integrating nanotechnology.

An Affordable and Easily Accessible Approach for Acrylonitrile Monomer Purification through a Simple Column Technique

This manuscript presents a dataset detailing a method for purifying monomers. Purification plays a crucial role in every chemical process, as it leads to an improvement in product quality through the removal of impurities. The primary method for monomer purification, like acrylonitrile (AN), is the distillation technique. However, this technique is unsafe and hard to set up or handle. A straightforward, risk-free, low-cost method like the column technique resolves these issues. A simple column technique demonstrated the successful execution of purifying AN. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses confirmed that AN was successfully purified, with purity reaching 99.8%. FTIR spectra revealed changes in the position and intensity of the stretching vibration peaks after purification. Also, the functional groups of the inhibitor monomethyl ether of hydroquinone (MeHQ) were undetected after purification. Furthermore, after purification, NMR spectra revealed the absence of aromatic protons and carbons associated with MeHQ. In conclusion, the column technique is a successful and inexpensive way to purify AN monomers. This makes it useful for a wide range of applications, especially in polymerization reactions where MeHQ needs to be removed to prevent self-polymerization during the initiation process.

基于立式泵装置的特低扬程排涝泵站研究

针对立式泵装置在特低扬程条件下水力性能较差的问题,对立式泵装置进行改进,首先设计其控制方程,然后引入密度残差对SIMPLE算法改进以提高计算效率。结果表明,改进立式泵装置的损失值在40 mm以下,数值模拟和实际工程中扬程工况点效率均在69%以上,提高了效率,并降低了水力损失。证明了改进立式泵装置的有效性及稳定性,其在特低扬程条件下具有广阔的应用前景。

Surprising New Bohr Models for H2and H2+

Niels Bohr constructed the first version of quantum mechanics. It has been called “old quantum mechanics” with a connotation of being obsolete. It is logically consistent, however, and deserves the name of simple quantum mechanics (SQM). It differs only from the semiclassical approximation by assuming that the average position and average velocity of an electron can be sharply defined on closed orbits. This assumption does not contradict Heisenberg’s uncertainty relations, since the quantization rule means that the electron can be anywhere on this orbit when it allows for stationary waves. This approach was remarkably efficient for one electron in hydrogen atoms and even for the electron pair in hydrogen molecules. However, dissociation of H2 and determination of the orbit of the single electron in H2+led to problems that remained unsolved for more than 100 years. Their solution, presented here, yields more physical insight and reveals, for instance, that mutual polarization of two hydrogen atoms can yield a metastable state.

Life′s Simple 7干预减轻Her⁃2阳性乳腺癌患者化疗相关心血管系统损害的研究

目的探讨Life′s Simple 7(LS7)干预减轻Her⁃2阳性乳腺癌患者根治术后化疗相关心血管系统损害的作用。方法将120例Her⁃2阳性并接受标准化乳腺癌化疗的患者随机等量分为对照组及LS7组,对照组为标准化疗方案,LS7组为对照组基础上给予LS7干预12个月,后续通过比较两组治疗前后心血管系统损伤程度、焦虑、抑郁及生活质量等指标评价其对心血管系统损害的改善作用。结果相较于对照组,LS7组LS7总评分及7项心血管健康指标均优于对照组(P<0.05),LS7组LVEF较高(P<0.05)、NT⁃proBNP较低(P<0.05),焦虑和抑郁评分较低(P<0.05)、生活质量评分较高(P<0.05)。结论LS7干预可显著减轻Her⁃2阳性乳腺癌化疗相关心血管系统损害并改善乳腺癌患者的心理状况和生活质量,值得在临床推广。

低温差斯特林发动机热力学分析

在低温差斯特林发动机的功率预测和参数优化分析中,传统的分析方法并不实用。为了快速准确地预估低温差斯特林发动机的输出功率,文中研究二阶Simple模型在低温差斯特林发动机的热力学循环分析中的应用。描述了低温差斯特林发动机的简化结构模型与内部工质的温度特性,基于Simple模型推导低温差斯特林发动机中非理想换热器的实际换热方程式,分析发动机的回热损失、泵送损失和换热器实际换热量。通过实例计算说明低温差斯特林发动机系统内部工质的温度、压力和能量随曲柄转角的变化,分析低温差斯特林发动机的理论输出功率。将低温差斯特林发动机在不同加热温度下的实际输出功率与Simple模型的计算功率对比,对比结果显示,Simple模型计算的输出功率与实际输出功率之间的误差较小,表明Simple模型与低温差斯特林发动机的实际循环吻合较好。为了研究低温差斯特林发动机中回热器对发动机性能的影响,文中优化了低温差斯特林发动机的回热器结构,将回热器优化后的实际输出功率和Simple模型计算功率,与回热器优化前的实际输出功率和Simple模型计算功率对比。对比结果显示,优化回热器后的低温差斯特林发动机的实际输出功率与Simple模型计算功率均提高20%,表明优化回热器结构是提高低温差斯特林发动机性能的切实有效的方法。

基于响应面法的不同配比沥青混凝土性能平衡优化设计

采用4种不同标号沥青及3种油石比制备12组沥青混合料,通过车辙试验、Overlay Tester(OT)试验以及动态模量试验评价其高温性能、低温性能和力学性能。采用响应面法对不同沥青混合料的高温性能、低温抗裂性能、疲劳性能和力学性能进行平衡性分析。结果表明,采用高油石比和低标号沥青可显著提高混合料的高温性能及力学性能且具有一定的抗裂性能,根据性能叠加图推荐了满足高模量沥青混凝土高温性能、抗裂性能与力学性能标准的沥青标号与油石比范围,其结果对于合理进行不同标号沥青混凝土配合比设计具有较大的参考价值。

Simple shear extrusion versus equal channel angular pressing:A comparative study on the microstructure and mechanical properties of an Mg alloy

Two severe plastic deformation(SPD)techniques of simple shear extrusion(SSE)and equal channel angular pressing(ECAP)were employed to process an extruded Mg-6Gd-3Y-1.5Ag(wt%)alloy at 553 K for 1,2,4 and 6 passes.The microstructural evolutions were studied by electron back scattered diffraction(EBSD)analysis and transmission electron microscopy(TEM).The initial grain size of 7.5μm in the extruded alloy was reduced to about 1.3μm after 6 SPD passes.Discontinuous dynamic recrystallization was suggested to be operative in both SSE and ECAP,with also a potential contribution of continuous dynamic recrystallization at the early stages of deformation.The difference in the shear strain paths of the two SPD techniques caused different progression rate of dynamic recrystallization(DRX),so that the alloys processed by ECAP exhibited higher fractions of recrystallization and high angle grain boundaries(HAGBs).It was revealed that crystallographic texture was also significantly influenced by the difference in the strain paths of the two SPD methods,where dissimilar basal plane texture components were obtained.The compression tests,performed along extrusion direction(ED),indicated that the compressive yield stress(CYS)and ultimate compressive strength(UCS)of the alloys after both SEE and ECAP augmented continuously by increasing the number of passes.ECAP-processed alloys had lower values of CYS and UCS compared to their counterparts processed by SSE.This difference in the mechanical responses was attributed to the different configurations of basal planes with respect to the loading direction(ED)of each SPD technique.

成年人Life's Simple 7和非酒精性脂肪性肝病之间的关联

目的探究成年人中Life's Simple 7与非酒精性脂肪性肝病(NAFLD)之间的关联。方法数据来自2017-2018年国家健康和营养检查调查(NHANES)中招募的成年人。排除HBsAg阳性、抗-HCV阳性和大量饮酒后,通过肝脏振动控制瞬时弹性成像(VCTE)对NAFLD进行诊断。参考既往的研究计算Life's Simple 7,0~8分为低分组(inadequate),9~10分为平均组(average),11~14分为优秀组(optimal)。进行多因素Logistic回归分析相关性。结果分析了2376名参与者的数据。NAFLD的总患病率为42.0%,在inadequate、average和optimal评分类别中的患病率分别为62.5%、33.4%和10.8%(P<0.001)。多因素Logistics回归分析,调整了年龄、性别、种族和贫困收入比率(PIR)后显示Life's Simple 7得分越高,NAFLD患病风险降低。跟inadequate组对比,average组OR值为0.31(95%CI:0.23-0.42),optimal组的OR值为0.08(95%CI:0.05-0.13)。根据分层分析,这种关联在不同年龄、性别、种族和经济群体中是相似的。结论越高的Life's Simple 7评分与越低的NAFLD患病率相关。拥有理想的心血管健康指标可能有利于降低普通成年人NAFLD的患病率。

Focus on limbal stem cell deficiency and limbal cell transplantation

Limbal stem cell deficiency(LSCD)causes severe vision impairment and can lead to blindness,representing one of the most challenging ocular surface disorders.Stem cell deficiency can be congenital or,more often,acquired.The categorization of ocular surface transplantation techniques is crucial to achieving treatment homogeneity and quality of care,according to the anatomic source of the tissue being transplanted,genetic source,autologous or allogenic transplantation(to reflect histocompatibility in the latter group),and cell culture and tissue engineering techniques.The aim of this minireview is to provide a summary of the management of LSCD,from clinical characteristics and therapeutic outcomes to the development of novel therapeutic approaches.The manuscript also briefly summarizes recent findings in the current literature and outlines the future challenges to overcome in the management of the major types of ocular surface failure.

Symmetry phases of asymmetric simple exclusion processes on two lanes with an intersection

This paper studies two-lane asymmetric simple exclusion processes(ASEPs)with an intersection.In the upstream segments of the intersection,one particle can move to the next site with rate 1 if the site is empty,and the other particle can move forward with rate p in the sites of downstream segments.The parameter p can represent the rate of slowing of motion,and the parameter is introduced to investigate spontaneous symmetry breaking(SSB)phenomenon.Extensive Monte Carlo simulations are carried out.It is shown that three symmetric phases exist and the SSB does not exist in the system.Simple mean field approach in which correlation of sites is ignored is firstly adopted to analyze the system,and the system is divided into four independent segments.It is found that the analytical results deviate from the simulation ones,especially when p is small.In addition,the inexsitence of SSB can only be explained qualitatively.Motivated by this,we carry out the cluster mean field analysis in which correlation of five sites is considered.It is shown that densities of the two upstream segments are equal,which demonstrates that the SSB does not exist.It is also shown that,as expected,the cluster mean field analysis performs much better than the simple mean field analysis.