Cross-sectional warping and precision of the first-order shear deformation theory for vibrations of transversely functionally graded curved beams

The warping may become an important factor for the precise transverse vibrations of curved beams.Thus,the first aim of this study is to specify the structural design parameters where the influence of cross-sectional warping becomes great and the first-order shear deformation theory lacks the precision necessary.The outof-plane vibrations of the first-order shear deformation theory are compared with the warping-included vibrations as the curvature and/or thickness increase for symmetric and asymmetric transversely-functionally graded(TFG)curved beams.The second aim is to determine the influence of design parameters on the vibrations.The circular/exact elliptical beams are formed via curved mixed finite elements(MFEs)based on the exact curvature and length.The stress-free conditions are satisfied on three-dimensional(3D)constitutive equations.The variation of functionally graded(FG)material constituents is considered based on the power-law dependence.The cross-sectional warping deformations are defined over a displacement-type FE formulation.The warping-included MFEs(W-MFEs)provide satisfactory 3D structural characteristics with smaller degrees of freedom(DOFs)compared with the brick FEs.The Newmark method is used for the forced vibrations.

浅海双深度Warping变换融合无源测距

针对浅海环境中利用单深度接收信号自相关函数的Warping变换方法测距时易出现的多值性问题,提出一种双深度Warping变换融合测距方法。该方法将双深度测量场的Warping变换提取结果与具有深度差异的拷贝场本征函数信息融合,判别简正波干涉项模态,提高测距的准确度。此外,针对实际海洋环境中测量场Warping变换特征峰位置难以准确提取的问题,将Warping变换的频率不变性与图像形态学方法结合以增强特征频率结构,提高后续测距的稳健性。海试数据处理结果显示,测距结果与实际距离符合较好,表明所提方法具有实际可行性。

Optimization Design of the Multi-Layer Cross-Sectional Layout of An Umbilical Based on the GA-GLM

Marine umbilical is one of the key equipment for subsea oil and gas exploitation,which is usually integrated by a great number of different functional components with multi-layers.The layout of these components directly affects manufacturing,operation and storage performances of the umbilical.For the multi-layer cross-sectional layout design of the umbilical,a quantifiable multi-objective optimization model is established according to the operation and storage requirements.Considering the manufacturing factors,the multi-layering strategy based on contact point identification is introduced for a great number of functional components.Then,the GA-GLM global optimization algorithm is proposed combining the genetic algorithm and the generalized multiplier method,and the selection operator of the genetic algorithm is improved based on the steepest descent method.Genetic algorithm is used to find the optimal solution in the global space,which can converge from any initial layout to the feasible layout solution.The feasible layout solution is taken as the initial value of the generalized multiplier method for fast and accurate solution.Finally,taking umbilicals with a great number of components as examples,the results show that the cross-sectional performance of the umbilical obtained by optimization algorithm is better and the solution efficiency is higher.Meanwhile,the multi-layering strategy is effective and feasible.The design method proposed in this paper can quickly obtain the optimal multi-layer cross-sectional layout,which replaces the manual design,and provides useful reference and guidance for the umbilical industry.

Association between triglyceride-glucose index and colorectal polyps:A retrospective cross-sectional study

BACKGROUND Colorectal polyps(CPs)are frequently occurring abnormal growths in the colorectum,and are a primary precursor of colorectal cancer(CRC).The triglyceride-glucose(TyG)index is a novel marker that assesses metabolic health and insulin resistance,and has been linked to gastrointestinal cancers.AIM To investigate the potential association between the TyG index and CPs,as the relation between them has not been documented.METHODS A total of 2537 persons undergoing a routine health physical examination and colonoscopy at The First People's Hospital of Kunshan,Jiangsu Province,China,between January 2020 and December 2022 were included in this retrospective cross-sectional study.After excluding individuals who did not meet the eligibility criteria,descriptive statistics were used to compare characteristics between patients with and without CPs.Logistic regression analyses were conducted to determine the associations between the TyG index and the prevalence of CPs.The TyG index was calculated using the following formula:Ln[triglyceride(mg/dL)×glucose(mg/dL)/2].The presence and types of CPs was determined based on data from colonoscopy reports and pathology reports.RESULTS A nonlinear relation between the TyG index and the prevalence of CPs was identified,and exhibited a curvilinear pattern with a cut-off point of 2.31.A significant association was observed before the turning point,with an odds ratio(95% confidence interval)of 1.70(1.40,2.06),P<0.0001.However,the association between the TyG index and CPs was not significant after the cut-off point,with an odds ratio(95% confidence interval)of 0.57(0.27,1.23),P=0.1521.CONCLUSION Our study revealed a curvilinear association between the TyG index and CPs in Chinese individuals,suggesting its potential utility in developing colonoscopy screening strategies for preventing CRC.

Association between Residential Greenness and Cardiometabolic Risk Factors among Adults in Rural Xinjiang Uygur Autonomous Region,China:A Cross-Sectional Study

Objective This study aimed to explore the relationships between residential greenness and cardiometabolic risk factors among rural adults in Xinjiang Uygur Autonomous Region(Xinjiang)and thus provide a theoretical basis and data support for improving the health of residents in this region.Methods We recruited 9,723 adult rural residents from the 51st Regiment of the Third Division of the Xinjiang Production and Construction Corps in September 2016.The normalized difference vegetation index(NDVI)was used to estimate residential greenness.The generalized linear mixed model(GLMM)was used to examine the association between residential greenness and cardiometabolic risk factors.Results Higher residential greenness was associated with lower cardiometabolic risk factor prevalence.After adjustments were made for age,sex,education,and marital status,for each interquartile range(IQR)increase of NDVI500-m,the risk of hypertension was reduced by 10.3%(OR=0.897,95%CI=0.836-0.962),the risk of obesity by 20.5%(OR=0.795,95%CI=0.695-0.910),the risk of type 2 diabetes by 15.1%(OR=0.849,95%CI=0.740-0.974),and the risk of dyslipidemia by 10.5%(OR=0.895,95%CI=0.825-0.971).Risk factor aggregation was reduced by 20.4%(OR=0.796,95%CI=0.716-0.885)for the same.Stratified analysis showed that NDVI500-m was associated more strongly with hypertension,dyslipidemia,and risk factor aggregation among male participants.The association of NDVI500-m with type 2 diabetes was stronger among participants with a higher education level.PM10 and physical activity mediated 1.9%-9.2%of the associations between NDVI500-m and obesity,dyslipidemia,and risk factor aggregation.Conclusion Higher residential greenness has a protective effect against cardiometabolic risk factors among rural residents in Xinjiang.Increasing the area of green space around residences is an effective measure to reduce the burden of cardiometabolic-related diseases among rural residents in Xinjiang.

Wideband radar cross-section reduction by a double-layer-plasma-based metasurface

Reduction of the radar cross-section(RCS) is the key to stealth technology. To improve the RCS reduction effect of the designed checkerboard metasurface and overcome the limitation of thinlayer plasma in RCS reduction technology, a double-layer-plasma-based metasurface—composed of a checkerboard metasurface, a double-layer plasma and an air gap between them—was investigated. Based on the principle of backscattering cancellation, we designed a checkerboard metasurface composed of different artificial magnetic conductor units;the checkerboard metasurface can reflect vertically incident electromagnetic(EM) waves in four different inclined directions to reduce the RCS. Full-wave simulations confirm that the doublelayer-plasma-based metasurface can improve the RCS reduction effect of the metasurface and the plasma. This is because in a band lower than the working band of the metasurface, the RCS reduction effect is mainly improved by the plasma layer. In the working band of the metasurface,impedance mismatching between the air gap and first plasma layer and between first and second plasma layers cause the scattered waves to become more dispersed, so the propagation path of the EM waves in the plasma becomes longer, increasing the absorption of the EM waves by the plasma. Thus, the RCS reduction effect is enhanced. The double-layer-plasma-based metasurface can be insensitive to the polarization of the incoming EM waves, and can also maintain a satisfactory RCS reduction band when the incident waves are oblique.

Time-Lapse Full-Waveform Inversion Using Cross-Correlation-Based Dynamic Time Warping

Offshore carbon capture, utilization, and storage(OCCUS) is regarded as a crucial technology for mitigating greenhouse gas emissions.Quantitative monitoring maps of sealed carbon dioxide are necessary in a comprehensive OCCUS project. A potential high-resolution method for the aforementioned purpose lies in the full-waveform inversion(FWI) of time-lapse seismic data. However, practical applications of FWI are severely restricted by the well-known cycle-skipping problem. A new time-lapse FWI method using cross-correlation-based dynamic time warping(CDTW) is proposed to detect changes in the subsurface property due to carbon dioxide(CO_(2)) injection and address the aforementioned issue. The proposed method, namely CDTW, which combines the advantages of cross-correlation and dynamic time warping, is employed in the automatic estimation of the discrepancy between the seismic signals simulated using the baseline/initial model and those acquired. The proposed FWI method can then back-project the estimated discrepancy to the subsurface space domain, thereby facilitating retrieval of the induced subsurface property change by taking the difference between the inverted baseline and monitor models. Numerical results on pairs of signals prove that CDTW can obtain reliable shifts under amplitude modulation and noise contamination conditions. The performance of CDTW substantially outperforms that of the conventional dynamic time warping method. The proposed time-lapse fullwaveform inversion(FWI) method is applied to the Frio-2 CO_(2) storage model. The baseline and monitor models are inverted from the corresponding time-lapse seismic data. The changes in velocity due to CO_(2) injection are reconstructed by the difference between the baseline and the monitor models.

Cross-section distortion and springback characteristics of double-cavity aluminum profile in force controlled stretch-bending

3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit−implicit solvent method.Considering the computational accuracy and efficiency,the optimal choices of numerical parameters and algorithms in FE modelling were determined.The formation mechanisms of cross-section distortion and springback were revealed.The effects of pre-stretching,post-stretching,friction,and the addition of internal fillers on forming quality were investigated.The results show that the stress state of profile in stretch-bending is uniaxial with only a circumferential stress.The stress distribution along the length direction of profile is non-uniform and the maximum tensile stress is located at a certain distance away from the center of profile.As aluminum profile is gradually attached to bending die,the distribution characteristic of cross-section distortion along the length direction of profile changes from V-shape to W-shape.After unloading the forming tools,cross-section distortion decreases obviously due to the stress relaxation,with a maximum distortion difference of 13%before and after unloading.As pre-stretching and post-stretching forces increase,cross-section distortion increases gradually,while springback first decreases and then remains unchanged.With increasing friction between bending die and profile,cross-section distortion slightly decreases,while springback increases.Cross-section distortion decreases by 83%with adding PVC fillers into the cavities of profile,while springback increases by 192.2%.

Dyslipidemia in Adults with Type 2 Diabetes in a Rural Community in Ganadougou, Mali: A Cross-Sectional Study

Dyslipidemia is a disorder where abnormally lipid concentrations circulate in the bloodstream. The disorder is common in type 2 diabetics (T2D) and is linked with T2D comorbidities, particularly cardiovascular disease. Dyslipidemia in T2D is typically characterized by elevated plasma triglyceride and low high-density lipoprotein cholesterol (HDL-C) levels. There is a significant gap in the literature regarding dyslipidemia in rural parts of Africa, where lipid profiles may not be captured through routine surveillance. This study aimed to characterize the prevalence and demo-graphic profile of dyslipidemia in T2D in the rural community of Ganadougou, Mali. We performed a cross-sectional study of 104 subjects with T2D in Ganadougou between November 2021 and March 2022. Demographic and lipid profiles were collected through cross-sectional surveys and serological analyses. The overall prevalence of dyslipidemia in T2D patients was 87.5% (91/104), which did not differ by sex (P = .368). High low-density lipoprotein cholesterol (LDL-C) was the most common lipid abnormality (78.9%, [82/104]). Dyslipidemia was associated with age and hypertension status (P = .013 and.036, respectively). High total and high LDL-C parameters were significantly associated with hypertension (P = .029 and .006, respectively). In low-resource settings such as rural Mali, there is a critical need to improve infrastructure for routine dyslipidemia screening to guide its prevention and intervention approaches. The high rates of dyslipidemia observed in Gandadougou, consistent with concomitant increases in cardiovascular diseases in Africa suggest that lipid profile assessments should be incorporated into routine medical care for T2D patients in African rural settings.

Prediction of(n,2n)reaction cross-sections of long-lived fission products based on tensor model

Interest has recently emerged in potential applications of(n,2n)reactions of unstable nuclei.Challenges have arisen because of the scarcity of experimental cross-sectional data.This study aims to predict the(n,2n)reaction cross-section of long-lived fission products based on a tensor model.This tensor model is an extension of the collaborative filtering algorithm used for nuclear data.It is based on tensor decomposition and completion to predict(n,2n)reaction cross-sections;the corresponding EXFOR data are applied as training data.The reliability of the proposed tensor model was validated by comparing the calculations with data from EXFOR and different databases.Predictions were made for long-lived fission products such as^(60)Co,^(79)Se,^(93)Zr,^(107)P,^(126)Sn,and^(137)Cs,which provide a predicted energy range to effectively transmute long-lived fission products into shorter-lived or less radioactive isotopes.This method could be a powerful tool for completing(n,2n)reaction cross-sectional data and shows the possibility of selective transmutation of nuclear waste.

Mental health and insomnia problems in healthcare workers after the COVID-19 pandemic:A multicenter cross-sectional study

BACKGROUND Healthcare workers(HCWs)are at increased risk of contracting coronavirus disease 2019(COVID-19)as well as worsening mental health problems and insomnia.These problems can persist for a long period,even after the pandemic.However,less is known about this topic.AIM To analyze mental health,insomnia problems,and their influencing factors in HCWs after the COVID-19 pandemic.METHODS This multicenter cross-sectional,hospital-based study was conducted from June 1,2023 to June 30,2023,which was a half-year after the end of the COVID-19 emergency.Region-stratified population-based cluster sampling was applied at the provincial level for Chinese HCWs.Symptoms such as anxiety,depression,and insomnia were evaluated by the Generalized Anxiety Disorder-7,Patient Health Questionnaire-9,and Insomnia Severity Index.Factors influencing the symptoms were identified by multivariable logistic regression.RESULTS A total of 2000 participants were invited,for a response rate of 70.6%.A total of 1412 HCWs[618(43.8%)doctors,583(41.3%)nurses and 211(14.9%)nonfrontline],254(18.0%),231(16.4%),and 289(20.5%)had symptoms of anxiety,depression,and insomnia,respectively;severe symptoms were found in 58(4.1%),49(3.5%),and 111(7.9%)of the participants.Nurses,female sex,and hospitalization for COVID-19 were risk factors for anxiety,depression,and insomnia symptoms;moreover,death from family or friends was a risk factor for insomnia symptoms.During the COVID-19 outbreak,most[1086(76.9%)]of the participating HCWs received psychological interventions,while nearly all[994(70.4%)]of them had received public psychological education.Only 102(7.2%)of the HCWs received individual counseling from COVID-19.CONCLUSION Although the mental health and sleep problems of HCWs were relieved after the COVID-19 pandemic,they still faced challenges and greater risks than did the general population.Identifying risk factors would help in providing targeted interventions.In addition,although a major proportion of HCWs have received public psychological education,individual interventions are still insufficient.

Patterns of Infertility and Abortion in Saudi Arabia: A Cross-Sectional Study

Background: Infertility and abortion are significant reproductive health concerns globally, impacting individuals' well-being and healthcare systems. In Saudi Arabia, cultural, social, and religious factors influence perceptions and management of these issues, necessitating research to understand the patterns and associated factors. Study Aim: This cross-sectional study aimed to investigate the patterns of infertility and abortion among 458 women in Saudi Arabia, focusing on demographic profiles, reproductive histories, medical conditions, and lifestyle factors. Methodology: Participants were recruited from healthcare facilities, and data on age, BMI, reproductive history, medical conditions, assisted reproduction methods, and lifestyle behaviors were collected. Statistical analyses, including chi-square tests, were conducted to examine associations between variables. Results: The majority of participants were aged 30 - 39 years (47.4%), with 76.9% experiencing secondary infertility. Among those with offspring (76.9%), 31% reported using assisted reproduction methods, primarily ovarian stimulators (54.2%). Abortion history was reported by 39.5% of participants. Significant associations were found between age and infertility type (X2 = 5.8, p = 0.054), having offspring and infertility type (X2 = 458.0, p = 0.001), menstrual irregularity and infertility type (X2 = 11.4, p = 0.001), and abortion history and delayed fertility (X2 = 10.4, p = 0.001). Conclusion: Our study reveals significant associations between demographic, medical, and lifestyle factors with infertility patterns and abortion history among Saudi women. These findings emphasize the need for tailored interventions addressing medical conditions, age-related factors, and access to reproductive healthcare services.

Theoretical analysis of the double-differential cross-sections of neutron,proton,deuteron,^(3)He,andαfor the p+^(6) Li reaction

Based on the unified Hauser–Feshbach and exciton model,which can describe the particle emission processes between discrete energy levels with energy,angular momentum,and parity conservations,a statistical theory of light nucleus reaction(STLN)is developed to calculate the double-differential cross-sections of the outgoing neutron and light charged particles for the proton-induced^(6) Li reaction.A significant difference is observed between the p+^(6) Li and p+^(7) Li reactions owing to the discrepancies in the energy-level structures of the targets.The reaction channels,including sequential and simultaneous emission processes,are analyzed in detail.Taking the double-differential cross-sections of the outgoing proton as an example,the influence of contaminations(such as^(1) H,^(7)Li,^(12)C,and^(16)O)on the target is identified in terms of the kinetic energy of the first emitted particles.The optical potential parameters of the proton are obtained by fitting the elastic scattering differential cross-sections.The calculated total double-differential cross-sections of the outgoing proton and deuteron at E_(p)=14 MeV agree well with the experimental data for different outgoing angles.Simultaneously,the mixed double differential cross-sections of^(3) He andαare in good agreement with the measurements.The agreement between the measured data and calculated results indicates that the two-body and three-body breakup reactions need to be considered,and the pre-equilibrium reaction mechanism dominates the reaction processes.Based on the STLN model,a PLUNF code for the p+^(6) Li reaction is developed to obtain an ENDF-6-formatted file of the double-differential cross-sections of the nucleon and light composite charged particles.

First Born Double Differential Cross-Section for Ionization of H (3d) by Incident Electron Impact

Double differential cross section (DDCS) of First-Born approximation is calcu-lated for the ionization of metastable 3d-state hydrogen atoms by electron impact energy at 150 eV and 250 eV. A multiple scattering theory is applied in the present study. The present results are compared with the other related the-oretical results for the ionization of hydrogen atoms from different metastable states and ground-state experimental results. The findings demonstrate a strong qualitative agreement with the existing results. The obtained results have an extensive scope for further study of such an ionization process.

A Cross-Sectional Study on The Prevalence of Anemia in Maintenance Hemodialysis and Peritoneal Dialysis Patients and Its Related Factors

Objective:To study the prevalence of anemia,the proportion of hemoglobin(Hb)levels,the treatment methods,and the influencing factors of Hb levels in maintenance hemodialysis(MHD)and peritoneal dialysis patients.Methods:In this study,602 patients with maintenance hemodialysis and continuous ambulatory peritoneal dialysis were enrolled from December 2020 to December 2022 in our hospital,and their medical records were collected and summarized.The main contents included the patient’s gender,age,primary disease,dialysis duration,dialysis method,the use of erythropoietic stimulating agents(ESA),intravenous iron,and laboratory tests.A Hb index exceeding 110 g/L was set as the standard for the prevalence of anemia.Results:The rate of anemia in patients undergoing blood purification was 83%.The proportion of ESA use was 84.1%,and the proportion of iron use was 76.7%,of which the proportion of intravenous iron used was 17.0%,and the proportion of folic acid used was 28.3%.Conclusion:The incidence of anemia in MHD patients was relatively high,with a low proportion of patients reaching the standard Hb levels.Risk factors include albumin(ALB)levels,iron storage,white blood cells,C-reactive protein,cholesterol,etc.Nutritional support,iron supplementation,and prevention of micro-inflammatory reactions can effectively promote the improvement of Hb indicators in dialysis patients to prevent anemia.

Prediction models of the ionization coefficient and ionization cross-section based on multi-layer molecular parameters

Prediction models were proposed to estimate the reduced Townsend ionization coefficient and ionization cross-section.A shape function of the reduced Townsend ionization coefficient curves was derived from the ionization collision probability model.The function had three parameters:the first ionization potential energy,A_(α),and B_(α).A_(α)and B_(α)were related to the molecule symmetry and size.The polarization of molecules could characterize the molecule symmetry.The multi-layer molecular cross-section(MMCS)was proposed to describe the contributions of electrons and molecule radius on different molecule surfaces to collisions.A prediction model of the ionization cross-section was also proposed based on Aα.The molecule parameters were calculated by the Becke3–Lee–Yang–Parr(B3LYP)method and the 6–311G**basis set.We used available data of 30 and 23 gases,respectively,to build the prediction models of reduced Townsend ionization coefficients and ionization cross-sections.The relationships between the molecular parameters Aαand Bαand the ionization cross-section were built up via nonlinear fittings.The determination coefficients R^(2)of Aα,Bα,and the ionization cross-section were 0.877,0.887,and 0.838,respectively.The results showed that the accuracy of models was positively correlated with the molecule symmetry and reduced electric field.This was mainly related to the accuracy of the MMCS model in predicting Aα.The MMCS model needed to be improved to describe the collision direction selectivity caused by the molecule asymmetry.Under a high reduced electric field,that error of Aαhad less influence on the prediction results.However,the prediction results for single atoms with high symmetry were poor.This may be due to the absolute error of the model close to single atoms’reduced Townsend ionization coefficients.The models could provide the basis for gas insulation prediction and discharge calculations,especially for symmetric molecules under a high electric field.

Endoscopy demand among county people in southeast China:A cross-sectional study

Objective The popularization of gastroenteroscopy and the introduction of comfortable medical care have further promoted the growth of people's demand,especially the demand for painless endoscopy.This cross-sectional study aims to investigate the current situation and change in county people's demand for endoscopy to promote the development of endoscopy centers in county hospitals in southeast China.Methods From October to December 2021,patients and their family members who came to the Gastroenterology Department in Suichang County People's Hospital of Zhejiang Province were randomly selected to complete the questionnaire.A total of 838 valid questionnaires were collected.Additionally,the original software data of the Endoscopy Center were sampled and retrieved(from October to December every year from 2018 to 2021)for statistical analysis of real-world data.Those who would choose painless endoscopy the next time in the valid questionnaires were included in the painless endoscopy group,while those who would choose ordinary endoscopy the next time were included in the ordinary endoscopy group.Results The stepwise forward binary logistic regression model analysis showed that,patients with“secondhand smoke exposure”were more willing to choose painless endoscopy(OR=1.459,95%CI:1.050-2.028,p=0.025).However,patients with an education level of“primary and below”and“junior high school”,and patients who are suffering from“currently experiencing abdominal distension”,were more willing to choose ordinary endoscopy(OR=0.270,95%CI:0.149-0.488,p<0.001;OR=0.528,95%CI:0.330-0.845,p=0.008;OR=0.536,95%CI:0.334-0.861,p=0.010).Patients with previous experience in painless endoscopy tended to choose painless endoscopy the next time,while patients with previous experience in ordinary endoscopy tended to choose ordinary endoscopy the next time(χ^(2)=140.97,p<0.001).From 2018 to 2021,the proportion of painless endoscopy has increased yearly(p<0.001).Most patients indicated that they would“regularly review gastroenteroscopy”(477/838,56.9%).Conclusions With Suichang County of Zhejiang Province as the representative,the demand for painless endoscopy for people's gastrointestinal cancer detection in southeast China has been increasing yearly.The development of endoscopy centers in county-level hospitals can basically meet the demand growth.Meanwhile,advanced concepts such as comfortable medical care and regular follow-up are gradually popularized at the grassroots level in southeast China.

Direct measurement of an energy-dependent single-event-upset cross-section with time-of-flight method at CSNS

To predict the soft error rate for applications, it is essential to study the energy dependence of the single-event-upset(SEU) cross-section. In this work, we present a direct measurement of the SEU cross-section with the Back-n white neutron source at the China Spallation Neutron Source. The measured cross section is consistent with the soft error data from the manufacturer and the result suggests that the threshold energy of the SEU is about 0.5 Me V, which confirms the statement in Iwashita’s report that the threshold energy for neutron soft error is much below that of the(n, α) cross-section of silicon.In addition, an index of the effective neutron energy is suggested to characterize the similarity between a spallation neutron beam and the standard atmospheric neutron environment.

Large eddy simulation of supersonic flow in ducts with complex cross-sections

Large Eddy Simulation(LES)has been employed for the investigation of supersonic flow characteristics in five ducts with varying cross-sectional geometries.The numerical results reveal that flow channel configurations exert a considerable influence on the mainstream flow and the near-wall flow behavior.In contrast to straight ducts,square-to-circular and rectangular-to-circular ducts exhibit thicker boundary layers and a greater presence of vortex structures.Given the same inlet area,rectangular-to-circular ducts lead to higher flow drag force and total pressure loss than square-to-circular ducts.Characterized by the substantial flow separation and shock waves,the"S-shaped duct shows significant vertically-asymmetric characteristics.

Knowledge,attitude,and practice of patients living with inflammatory bowel disease:A cross-sectional study

BACKGROUND Patients with inflammatory bowel diseases(IBDs)generally have poor knowledge,attitude,and practice of their disease,while the data from China are lacking.AIM To address this knowledge disparity among Chinese patients with IBD.METHODS This web-based,cross-sectional study was conducted on a cohort of IBD patients who visited the Second Affiliated Hospital of Wenzhou Medical University between December 2022 and February 2023.Their socio-demographic information and the knowledge,attitude,and practice scores were collected and estimated using a self-designed questionnaire.Pearson’s correlation analysis was used to determine the pairwise correlations among knowledge,attitude,and practice scores.A multivariate logistic regression analysis was further performed to determine the independent factors associated with their knowledge,attitude,and practice scores.RESULTS A total of 353 patients(224 males)with IBD completed the questionnaires.The mean knowledge,attitude,and practice scores were 10.05±3.46(possible range:0-14),41.58±5.23(possible range:0-56),44.20±7.39(possible range:0-56),respectively,indicating good knowledge,positive attitude,and proactive practice toward IBD.Pearson’s correlation analysis showed that the knowledge score had significant positive correlations with the attitude score(r=0.371,P<0.001)and practice score(r=0.100,P<0.001).The attitude score had a significant positive correlation with the practice score(r=0.452,P<0.001).Moreover,multivariate logistic regression analysis showed that aged 30-40 years[odds ratio(OR)=4.06,95%confidence interval(CI):1.04-15.82,P=0.043],middle school education(OR=3.98,95%CI:1.29-12.33,P=0.017),high school/technical secondary school education(OR=14.06,95%CI:3.92-50.38,P<0.001),and junior college/bachelor’s degree and above education(OR=15.20,95%CI:4.15-55.650,P<0.001)were independently associated with good knowledge.The higher knowledge score was independently associated with a positive attitude(OR=1.23,95%CI:1.11-1.36,P<0.001).The higher attitude score was independently associated with proactive practice(OR=1.20,95%CI:1.11-1.30,P<0.001).CONCLUSION Chinese patients with IBD might have good knowledge,a positive attitude,and proactive practice toward their disease.However,a small number of specific items require education.