期刊文献+
共找到783篇文章
< 1 2 40 >
每页显示 20 50 100
Coordinated observations on the spatiotemporal development of global-scale dipolarizations and their coupling to meso-scale dipolarizations
1
作者 Sheng Tian J.M.Weygand +5 位作者 J.Liu J.R.Wygant L.Lyons V.Angelopoulos J.Bortnik G.D.Reeves 《Earth and Planetary Physics》 2026年第2期291-301,共11页
Global-and meso-scale dipolarizations are well-known features of Earth’s magnetosphere,but their coupling remains poorly understood.Here,using a new approach that combines two-dimentional(2D)ionospheric field-aligned... Global-and meso-scale dipolarizations are well-known features of Earth’s magnetosphere,but their coupling remains poorly understood.Here,using a new approach that combines two-dimentional(2D)ionospheric field-aligned current(FAC)maps with coordinated observations from a network of magnetospheric satellites,we directly show that individual global-scale dipolarizations can expand from the nightside to,or even into,the dayside.These expansions are enduring(20–30 minutes),slow(2–4 deg/min),and global in extent(up to 12 h in local time),consistent with previous statistical inferences but now explicitly observed.The expanding FACs form a two-sheet current system as described by the Boström II model.In contrast,meso-scale dipolarizations are bursty(a few minutes),fast(several tens deg/min),and localized(several hours in local time),as evidenced by auroral expansions and satellite data.They are associated with the line-current system as described by the Boström I model(i.e.,the substorm current wedge).Notably,meso-scale dipolarizations often emerge near the expanding edge of a global-scale dipolarization,suggesting a dynamic coupling between the two scales.These observations provide a complementary scenario to the simulation-based interpretation that global-scale dipolarizations result from the accumulation of meso-scale dipolarizations.Here,meso-scale dipolarizations appear far less frequently than in simulations and occur around the edge of global-scale dipolarizations.This result implies that meso-scale dipolarizations may be sporadically triggered during the azimuthal expansion of global-scale dipolarizations. 展开更多
关键词 DIPOLARIZATION field-aligned current magnetosphere−ionosphere coupling
在线阅读 下载PDF
汉中天坑群天星岩东方剑齿象牙齿化石年代学研究
2
作者 陈清敏 成星 +11 位作者 洪增林 邓丽 张瑜 李兴文 郭岐明 唐力 胡义 王鹏 王研 王高红 程海 RLawrence Edwards 《中国岩溶》 北大核心 2025年第4期887-896,共10页
末次冰期全球气候波动频繁,影响了哺乳动物的演化和迁移历史。汉中天坑群丰富的地质生物记录是重要的古气候、古环境研究材料,并使用石笋重建了秦巴地区末次冰期的季风演化历史。汉中天坑群考察过程中发现的东方剑齿象化石也为认识晚第... 末次冰期全球气候波动频繁,影响了哺乳动物的演化和迁移历史。汉中天坑群丰富的地质生物记录是重要的古气候、古环境研究材料,并使用石笋重建了秦巴地区末次冰期的季风演化历史。汉中天坑群考察过程中发现的东方剑齿象化石也为认识晚第四纪古生物演化历史和生态环境响应提供了重要的参考资料。文章对东方剑齿象样品进行铀系(U-Th)和碳十四(14C)测年,并参考化石上结晶的碳酸钙铀系年龄,判断汉中天坑群天星岩东方剑齿象的生存时代约为27.5kyr BP(kyr=千年;BP=Before the present, present定义为1950年)附近MIS3阶段的DO暖事件。结合已有的石笋氧同位素序列和其他的古气候记录,推测MIS3时期汉中地区气候很可能比现代更温暖湿润,剑齿象从北方迁移到秦岭南部并演化为东方剑齿象,而且主要依靠南方广泛而稳定存在的C_(3)植被为食。到末次盛冰期,气候极端寒冷,东方剑齿象灭绝,而亚洲象因为觅食生态灵活存活至今,生存区间退缩到了西南亚热带地区。 展开更多
关键词 汉中天坑群 天星岩 东方剑齿象 年代学 生态环境响应
在线阅读 下载PDF
Dynamic characterization of viscoelasticity during polymer flooding:A two-phase numerical well test model and field study 被引量:1
3
作者 Yang Wang Shi-Long Yang +3 位作者 Hang Xie Yu Jiang Shi-Qing Cheng Jia Zhang 《Petroleum Science》 2025年第6期2493-2501,共9页
Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer... Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer solutions exhibit non-Newtonian and nonlinear flow behavior including shear thinning and shear thickening,polymer convection,diffusion,adsorption,retention,inaccessible pore volume,and reduced effective permeability.However,available well test model of polymer flooding wells generally simplifies these characteristics on pressure transient response,which may lead to inaccurate results.This work proposes a novel two-phase numerical well test model to better describe the polymer viscoelasticity and nonlinear flow behavior.Different influence factors that related to near-well blockage during polymer flooding process,including the degree of blockage(inner zone permeability),the extent of blockage(composite radius),and polymer flooding front radius are explored to investigate these impacts on bottom hole pressure responses.Results show that polymer viscoelasticity has a significant impact on the transitional flow segment of type curves,and the effects of near-well formation blockage and polymer concentration distribution on well test curves are very similar.Thus,to accurately interpret the degree of near-well blockage in injection wells,it is essential to first eliminate the influence of polymer viscoelasticity.Finally,a field case is comprehensively analyzed and discussed to illustrate the applicability of the proposed model. 展开更多
关键词 Polymer flooding Two-phase flow Numerical well test model Viscoelastic characteristic Nonlinear flow Near-well blockage
原文传递
Impact of Helicobacter pylori Eradication on Clinical and Laboratory Parameters in Non-alcoholic Fatty Liver Disease Patients:A Systematic Review and Meta-analysis of Randomized Controlled Trials 被引量:1
4
作者 Fouad Jaber Saqr Alsakarneh +12 位作者 Azizullah Beran Tala Alsharaeh Ahmed-Jordan Salahat Abdelrahman Abdelshafi Islam Mohamed Willie Johnson Khaled Elfert Mohammad Jaber Mohammad Almeqdadi Mohamed Ahmed Hassan Ghoz Wendell K.Clarkston John H.Helzberg 《Current Medical Science》 2025年第1期1-10,共10页
Objective Helicobacter pylori(HP)infection is associated with non-alcoholic fatty liver disease(NAFLD)and insulin resistance;however,the correlation between HP eradication and NAFLD remains controversial.This systemat... Objective Helicobacter pylori(HP)infection is associated with non-alcoholic fatty liver disease(NAFLD)and insulin resistance;however,the correlation between HP eradication and NAFLD remains controversial.This systematic review and meta-analysis examined the effect of HP treatment on clinical and laboratory parameters in NAFLD patients.Methods We conducted a literature search of the PubMed,Embase,Scopus,and Web of Science databases through Septem-ber 2023 for randomized controlled trials(RCTs)examining the effect of HP treatment on NAFLD patients versus lifestyle changes alone.The primary outcome was the change in steatosis parameters.The secondary endpoints were changes in anthropometric parameters,inflammatory markers(TNF-α),and metabolic parameters(fasting blood glucose,homeostasis model assessment of insulin resistance,AST/ALT,and lipid profile).The random effects model was used to calculate the standardized mean difference(SMD)with associated 95%confidence intervals(CIs)for our desired outcome.Results Four RCTs met our inclusion criteria.A total of 453 patients were included(mean age 42.8 years,58.5%males),228(50.3%)of whom were in the HP eradication group and 225(49.7%)of whom were in the lifestyle modification group.Compared with lifestyle modification alone,HP eradication had a significant effect on reducing liver steatosis and TNF-αlevels(SMD:-0.9;95%CI-14.67,-3.82,I^(2)=0%and SMD:-6.3;95%CI-9.04,-3.56,I^(2)=0%,respectively).No sig-nificant effect on other metabolic parameters was found.Conclusions HP eradication significantly reduced liver steatosis and TNF-αlevels in NAFLD patients.However,HP eradi-cation did not significantly affect other metabolic indices compared to lifestyle changes alone. 展开更多
关键词 Non-alcoholic fatty liver disease Helicobacter pylori Randomized controlled trials Hepatic steatosis Anthropometric measurements Insulin resistance
暂未订购
Concomitant resection of Meckel diverticulum during laparoscopic appendectomy: Retrospective propensity-matched ACS-NSQIP study and a case report
5
作者 Sean Huu-Tien Nguyen Matthew Wheelwright +3 位作者 Victor Vakayil Pravin Meshram Ryan O’Donnell James Vail Harmon 《World Journal of Gastrointestinal Surgery》 2025年第5期355-362,共8页
BACKGROUND The surgical management of incidentally detected Meckel diverticulum(MD)during appendectomy remains controversial.We present a case report alongside an analysis of the ACS-NSQIP database to evaluate postope... BACKGROUND The surgical management of incidentally detected Meckel diverticulum(MD)during appendectomy remains controversial.We present a case report alongside an analysis of the ACS-NSQIP database to evaluate postoperative outcomes associated with concomitant Meckel diverticulectomy during laparoscopic appen-dectomy.CASE SUMMARY We report the case of a 34 year-old woman presenting with acute appendicitis and an incidentally detected MD.The patient presented to the emergency department with right lower quadrant pain.Computed tomography revealed acute appen-dicitis with possible contained perforation.During laparoscopic operative ma-nagement of her appendicitis,an incidental MD was noted and resected via a stapled diverticulectomy.She was discharged on the same day as her surgery without complication.Postoperative pathology examination revealed an MD without acute pathology.To review outcomes associated with performing in-cidental Meckel diverticulectomy during laparoscopic appendectomy,an ad-ditional 12-year retrospective ACS-NSQIP analysis was performed.To compare between laparoscopic appendectomy alone and Meckel diverticulectomy with appendectomy(MA),propensity matching was employed.MA was associated with a significantly increased operative time and longer hospital stays.However,no significant differences in 30-day mortality or postoperative outcomes were observed between the groups.Core Tip:Incidental Meckel diverticulum(MD)is rare but can be encountered during routine abdominal surgical procedures.The surgical management of incidental MD remains debated.We report a case of resection of an incidentally detected MD during laparoscopic appendectomy with no complications on the 6-year follow-up.ACS-NSQIP analysis demonstrated that concurrent incidental Meckel diverticulectomy with laparoscopic appendectomy does not increase morbidity and mortality.However,Meckel diverticulectomy with laparoscopic appendectomy increases resource utilization.We recommend resection on the basis of individualized patient’s factors and acknowledge that incidental Meckel diverticulectomy can be efficiently and safely performed in selected patients.INTRODUCTION Surgical resection of an incidentally detected Meckel diverticulum(MD)during appendectomy for acute appendicitis remains controversial.We present a case report and analyzed the ACS-NSQIP database to examine postoperative complications and patient outcomes associated with concomitant Meckel diverticulectomy during appendectomy.Although generally asymptomatic,MD can present with painless bleeding,diverticulitis,perforation,bowel obstruction,intussusception,fistula,and neoplasm[1-3].Two of the most common symptoms in children include bleeding and obstruction,whereas in up to 58%of adults with symptomatic MD,Meckel diverticulitis is reported to be the presenting feature[4].Mechanical obstruction,volvulus,and intestinal strangulation may result from intussusception due to MD[5].Moreover,MD may present with symptoms indicative of enterocyst or intestinal–umbilical fistula[6].A consensus that complicated and symptomatic MD should be resected exists;however,whether incidentally detected asymptomatic MD should be resected remains unclear.Risk scoring systems to resect asymptomatic MD have been described however there are few registry database analyses analyzing incidental MD resection outcomes[6].We here compared postoperative complications and patient outcomes associated with concomitant Meckel diverticulectomy during primary laparoscopic appendectomy compared with laparoscopic appendectomy alone(AA).rovsing sign was elicited.The extremities were warm to touch and well perfused.TREATMENT The patient proceeded to the operating room for standard laparoscopic appendectomy.Intraoperatively,the tip of the appendix was distended and inflamed.A contained perforation was revealed.The base of the appendix,which was grossly normal,was divided using a laparoscopic stapler.The mesoappendix was divided using a LigaSure©energy device.The appendix was removed and placed in an Endocatch bag.A protrusion from the small bowel was noted extending along the antimesenteric side of the ileum consistent with an MD.A diverticulum was laparoscopically palpated and contained a firm mass.To decrease the risk of future complications and owing to the described firmness,the diverticulum was removed.Using a laparoscopic stapler,diverticulectomy was performed in a longitudinal manner parallel to the long axis of the bowel on the antimesenteric surface.The MD was removed from the abdomen and placed in an Endocatch pouch.The procedure was completed,and the patient was subsequently taken to the post anesthesia care unit. 展开更多
关键词 ACS-NSQIP NSQIP Meckel diverticulum Meckel diverticulectomy Appendectomy Appendicitis Case report
暂未订购
Benchmarking of Large Language Models for the Dental Admission Test
6
作者 Yu Hou Jay Patel +5 位作者 Liya Dai Emily Zhang Yang Liu Zaifu Zhan Pooja Gangwani Rui Zhang 《Health Data Science》 2025年第1期216-224,共9页
Background:Large language models(LLMs)have shown promise in educational applications,but their performance on high-stakes admissions tests,such as the Dental Admission Test(DAT),remains unclear.Understanding the capab... Background:Large language models(LLMs)have shown promise in educational applications,but their performance on high-stakes admissions tests,such as the Dental Admission Test(DAT),remains unclear.Understanding the capabilities and limitations of these models is critical for determining their suitability in test preparation.Methods:This study evaluated the ability of 16 LLMs,including general-purpose models(e.g.,GPT-3.5,GPT-4,GPT-4o,GPT-o1,Google’s Bard,mistral-large,and Claude),domain-specific finetuned models(e.g.,DentalGPT,MedGPT,and BioGPT),and open-source models(e.g.,Llama2-7B,Llama2-13B,Llama2-70B,Llama3-8B,and Llama3-70B),to answer questions from a sample DAT.Quantitative analysis was performed to assess model accuracy in different sections,and qualitative thematic analysis by subject matter experts examined specific challenges encountered by the models.Results:GPT-4o and GPT-o1 outperformed others in text-based questions assessing knowledge and comprehension,with GPT-o1 achieving perfect scores in the natural sciences(NS)and reading comprehension(RC)sections.Open-source models such as Llama3-70B also performed competitively in RC tasks.However,all models,including GPT-4o,struggled substantially with perceptual ability(PA)items,highlighting a persistent limitation in handling image-based tasks requiring visual-spatial reasoning.Fine-tuned medical models(e.g.,DentalGPT,MedGPT,and BioGPT)demonstrated moderate success in text-based tasks but underperformed in areas requiring critical thinking and reasoning.Thematic analysis identified key challenges,including difficulties with stepwise problem-solving,transferring knowledge,comprehending intricate questions,and hallucinations,particularly on advanced items.Conclusions:While LLMs show potential for reinforcing factual knowledge and supporting learners,their limitations in handling higherorder cognitive tasks and image-based reasoning underscore the need for judicious integration with instructor-led guidance and targeted practice.This study provides valuable insights into the capabilities and limitations of current LLMs in preparing prospective dental students and highlights pathways for future innovations to improve performance across all cognitive skills assessed by the DAT. 展开更多
关键词 capabilities limitations models dental admission test language models llms BENCHMARKING performance dental admission large language models high stakes tests
原文传递
Quorum quenching enzymes disrupt bacterial communication in a sex-and dose-dependent manner
7
作者 Aneesh Syal Maria Martell +5 位作者 Rakesh Sikdar Matthew Dietz Zachary Ziegert Cyrus Jahansouz Mikael H.Elias Christopher Staley 《Animal Models and Experimental Medicine》 2025年第3期473-482,共10页
Background:Over the past 50 years,the incidence of obesity has gradually increased,necessitating investigation into the multifactorial contributors to this disease,including the gut microbiota.Bacteria within the huma... Background:Over the past 50 years,the incidence of obesity has gradually increased,necessitating investigation into the multifactorial contributors to this disease,including the gut microbiota.Bacteria within the human gut microbiome communicate using a density-dependent process known as quorum sensing(QS),in which autoinducer(AI)molecules(e.g.,N-acyl-homoserine lactones[AHLs])are produced to enable bacterial interactions and regulate gene expression.Methods:We aimed to disrupt QS using quorum quenching(QQ)lactonases GcL and SsoPox,which cleave AHL signaling molecules in a taxa-specific manner based on differing enzyme affinities for different substrates.We hypothesized that QQ hinders signals from obesity-associated pathobionts,thereby slowing or preventing obesity.Results:In a murine model of dietinduced obesity,we observed GcL and SsoPox treatments have separate sex-dependent and dose-dependent effects on intestinal community composition and diversity.Notably,male mice given 2 mg/mL SsoPox exhibited significant changes in the relative abundances of gram-negative taxa,including Porphyromonadaceae,Akkermansiaceae,Muribaculaceae,and Bacteroidales(Kruskal-Wallis p<0.001).Additionally,we used covariance matrix network analysis to model bacterial taxa co-occurrence due to QQ enzyme administration.There were more associations among taxa in control mice,particularly among gram-negative bacteria,whereas mice receiving SsoPox had the fewest associations.Conclusions:Overall,our study establishes proof of concept that QQ is a targetable strategy for microbial control in vivo.Further characterization and dosage optimization of QQ enzymes are necessary to harness their therapeutic capability for the treatment of chronic microbial-associated diseases. 展开更多
关键词 microbiome microbiota therapeutics obesity quorum sensing
暂未订购
Safety of nadofaragene firadenovec-vncg:review of data from phase 2 and phase 3 studies
8
作者 Badrinath R.Konety Yair Lotan Amanda Myers 《The Canadian Journal of Urology》 2025年第1期29-36,共8页
Introduction:Non–muscle-invasive bladder cancer(NMIBC)is a common malignancy worldwide.While Bacillus Calmette-Guérin(BCG)is standard of care for treatment for most patients with high-risk NMIBC,many will either... Introduction:Non–muscle-invasive bladder cancer(NMIBC)is a common malignancy worldwide.While Bacillus Calmette-Guérin(BCG)is standard of care for treatment for most patients with high-risk NMIBC,many will either not respond to BCG initially or will eventually develop BCG-unresponsive disease.A treatment option in BCG-unresponsive disease is nadofaragene firadenovec-vncg(Adstiladrin),a nonreplicating adenoviral vector–based gene therapy approved by the US Food and Drug Administration(FDA)for the treatment of adults with high-risk BCGunresponsive NMIBC with carcinoma in situ with or without papillary tumors.Objective:To review safety outcomes of participants who received the FDA-approved dose of nadofaragene firadenovec(3×10^(11)vp/mL)across phase 2(NCT01687244)and phase 3(NCT02773849)studies.Methods:Data from the phase 2 and phase 3 studies were collected and analyzed.The findings were reported using descriptive statistics to summarize the key outcomes observed across studies.Results:Common adverse events(AEs)among nadofaragene firadenovec recipients were leakage of fluid around the urinary catheter,fatigue,bladder spasm,chills,dysuria,and micturition urgency.Most study drug–related AEs were mild and localized,with no grade 4 or 5 study drug–related AEs observed in either study.Study drug–related AEs were generally transient,with most study drug–related AEs having a median duration of≤2.0 days in the phase 3 study.Discontinuation rates due to study drug–related AEs were low,with none(0%)in the phase 2 study and three(1.9%)in the phase 3 study.No specific postmarketing surveillance was required by the FDA besides routine pharmacovigilance monitoring;no new real-world safety signals have been observed.Conclusion:Nadofaragene firadenovec demonstrated a favorable and tolerable safety profile across its clinical study program,allowing for broad patient selection among those with high-risk BCG-unresponsive NMIBC. 展开更多
关键词 bladder cancer gene therapy urinary bladder urinary bladder neoplasms non–muscleinvasive bladder cancer
暂未订购
Navigating women with congenital heart disease during pregnancy: Management strategies and future directions
9
作者 Bibhuti B Das Varun Aggarwal Shriprasad R Deshpande 《World Journal of Cardiology》 2025年第6期5-28,共24页
Women with adult congenital heart disease(CHD)face unique challenges during pregnancy,as gestational cardiovascular(CV)and hemodynamic changes can exacerbate underlying cardiac conditions.While these adaptations are w... Women with adult congenital heart disease(CHD)face unique challenges during pregnancy,as gestational cardiovascular(CV)and hemodynamic changes can exacerbate underlying cardiac conditions.While these adaptations are well tole-rated in women with structurally and functionally normal hearts,they pose sig-nificant risks for those with adult CHD(ACHD),whether repaired,palliated,or with residual defects.Maternal CHD is associated with an increased risk of ad-verse CV events,including stroke,heart failure,arrhythmias,and thromboem-bolic complications during pregnancy and the peripartum period.Effective mana-gement requires a multidisciplinary team,including cardiologists,perinatologists,anesthesiologists,and other skilled care providers.Risk stratification tools such as the modified World Health Organization classification,CARPREG II,and ZA-HARA scores are useful for predicting maternal and fetal outcomes and guiding clinical decision-making.Preconception counseling plays a critical role in asse-ssing individual risks,optimizing cardiac function,and educating patients about potential complications.Future research should prioritize innovative therapies,including targeted pharmacological agents and minimally invasive interventions,alongside improved screening methods to identify high-risk patients before symp-tomatic disease manifests.This review synthesizes current literature on managing pregnant women with ACHD,highlights gaps in clinical practice,and explores future directions to enhance care.Addressing these challenges is essential to improving maternal and fetal outcomes and ensuring comprehensive,patient-centered care throughout the reproductive journey. 展开更多
关键词 Congenital heart disease PREGNANCY Women with congenital heart disease CONTRACEPTION Postpartum care Maternal&fetal outcomes
暂未订购
A case study on the stability of a big underground powerhouse cavern cut by an interlayer shear zone in the China Baihetan hydropower plant
10
作者 Lifang Zou Guotao Meng +3 位作者 Jiayao Wu Wei Fu Weijiang Chu Weiya Xu 《Deep Underground Science and Engineering》 2025年第2期305-315,共11页
The big underground powerhouse cavern of the China Baihetan hydropower plant is 438m long,34m wide,and 88.7m high.It is cut by a weak interlayer shear zone and its high sidewall poses a huge stability problem.This pap... The big underground powerhouse cavern of the China Baihetan hydropower plant is 438m long,34m wide,and 88.7m high.It is cut by a weak interlayer shear zone and its high sidewall poses a huge stability problem.This paper reports our successful solution of this problem through numerical simulations and a replacement-tunnel scheme in the detailed design stage and close site monitoring in the excavation stage.Particularly,in the detail design stage,mechanical parameters of the shear zone were carefully determined through laboratory experiments and site tests.Then,deformation of the surrounding rocks and the shear zone under high in situ stress conditions was predicted using 3 Dimensional Distinct Element Code(3DEC).Subsequently,a replacement-tunnel scheme was proposed for the treatment on the shear zone to prevent severe unloading relaxation of surrounding rocks.In the construction period,excavation responses were closely monitored on deformations of surrounding rocks and the shear zone.The effect of local cracking in the replacement tunnels on sidewall stability was evaluated using the strength reduction method.These monitoring results were compared with the predicted numerical simulation in the detailed design stage.It is found that the shear zone greatly modified the deformation mode of the cavern surrounding rocks.Without any treatment,rock mass deformation on the downstream sidewall was larger than 125mm and the shearing deformation of the shear zone was 60–70 mm.These preset replacement tunnels can reduce not only the unloading and relaxation of rock masses but also the maximum shearing deformation of the shear zone by 10–20 mm.The predictions by numerical simulation were in good agreement with the monitoring results.The proposed tunnel-replacement scheme can not only restrain the shear zone deformation but also enhance the safety of surrounding rocks and concrete tunnels.This design procedure offers a good reference for interaction between a big underground cavern and a weak layer zone in the future. 展开更多
关键词 3DEC control measures DEFORMATION interlayer shear zone underground powerhouse cavern
原文传递
Investigation of meso-mechanical properties of Jinping dolomitic marble based on flat-joint model
11
作者 Suifeng Wang D.O.Potyondy +3 位作者 Weijiang Chu Liping Zhang Xianyu Zhao Tao Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第6期3464-3478,共15页
Brittle rock has the mechanical characteristics of a high ratio of uniaxial compressive strength to tensilestrength, brittle-ductile transition, and so on. The mineral meso-structure of brittle rock shows theinterlock... Brittle rock has the mechanical characteristics of a high ratio of uniaxial compressive strength to tensilestrength, brittle-ductile transition, and so on. The mineral meso-structure of brittle rock shows theinterlocking behavior and there are some microcracks between the mineral grains, so it is difficult toanalyze the mechanical characteristics accurately with a regular constitutive model. The previous numericalmodels have some limitations when applied to brittle rock, that they cannot provide sufficientinternal interlocking and are incapable of considering the microcracks. These limitations are addressedby using the updated flat-joint contact model to join notional polygonal particles with an initial gap andincreasing the particle coordination number by adding flat-joint contacts to more particles that arewithin some non-zero distance of one another via the range coefficient contact identification method. Acomparison of experimental and numerical results confirms that the updated flat-jointed model providesa good match with the mechanical properties of brittle rock. In this paper, we investigate the influence ofmineral meso-structure (micro-cracks, range coefficient, and radius multiplier) on the meso-mechanicalproperties of Jinping dolomitic marble via the updated flat-joint contact model under direct-tension testsand compression tests. It is found that the updated model can reproduce the microstructure effect ofbrittle rock and can better simulate the mechanical characteristics of the brittle rock than conventionalmodels, such as high strength ratio, brittle-ductile transition, initial nonlinearity, and different modulusin compression and tension. 展开更多
关键词 Brittle rock Grain interlocking Mechanical properties Meso-structure Discrete element method
在线阅读 下载PDF
Environmental studies of priority persistent contaminants:A special issue dedicated to Professor Chuanyong Jing
12
作者 Emma Jing Li Yan +1 位作者 Guibin Jiang X.Chris Le 《Journal of Environmental Sciences》 2025年第7期1-5,共5页
It is with profound respect and gratitude that we dedicate this special issue of the Journal of Environmental Sciences to the memory of Professor Chuanyong Jing,whose outstanding contributions to environmental science... It is with profound respect and gratitude that we dedicate this special issue of the Journal of Environmental Sciences to the memory of Professor Chuanyong Jing,whose outstanding contributions to environmental sciences have advanced the field and continue to resonate with both academia and the broader environmental community. 展开更多
关键词 Professor Chuanyong Jing persistent contaminants environmental sciences special issue
原文传递
Mood alteration and heart rate variability in patients with cancer on treatment
13
作者 Yun-Chen Chang Wei-Nung Liu +1 位作者 Felicia Lin Gen-Min Lin 《World Journal of Cardiology》 2025年第6期1-4,共4页
In this article,Deng and Song showed compelling evidence on the connection between heart rate variability(HRV)alterations and cancer in 127 cancer patients compared with healthy reference individuals,highlighting auto... In this article,Deng and Song showed compelling evidence on the connection between heart rate variability(HRV)alterations and cancer in 127 cancer patients compared with healthy reference individuals,highlighting autonomic nervous system dysfunction as a significant physiological manifestation in cancer patients.We discussed that the reduced HRV may be associated with cancer treatments,e.g.,operation,chemotherapy and pain control and psychological response such as depression and anxiety related to the affected cancer.A management such as medicine to mood disturbances related to cancer has been shown a benefit to improve HRV in cancer patients. 展开更多
关键词 CANCER CHEMOTHERAPY Heart rate variability Mental stress HEART
暂未订购
Comparative effectiveness of lifestyle interventions on children's body composition management:A systematic review and network meta-analysis
14
作者 Xiwen Su Mohamed A.Hassan +1 位作者 HyunJoon Kim Zan Gao 《Journal of Sport and Health Science》 2025年第1期38-48,共11页
Purpose:This study aimed to provide comparative evidence on the effectiveness of various lifestyle interventions on body composition management for preschool and school-aged children.Methods:PubMed(MEDLINE),Embase,CIN... Purpose:This study aimed to provide comparative evidence on the effectiveness of various lifestyle interventions on body composition management for preschool and school-aged children.Methods:PubMed(MEDLINE),Embase,CINAHL,and Web of Science were systematically searched for this network meta-analysis.Randomized controlled studies(RCTs)that included children aged 4-12 years with no physical or mental conditions;performed at least 1 type of lifestyle intervention;reported change in body mass index(BMI),BMI z-score,or body fat percentage(BFP);and were published between January2010 and August 2023 were included.Results:The final analysis included 91 RCTs with aggregate data for 58,649 children.All interventions were categorized into single-arm approaches(physical activity,diet,and behavioral and informational support)and combined arms approaches(bicomponent and multicomponent treatment).Multicomponent treatment showed significant effectiveness on the reduction of BMI(mean deviation(MD)-0.49,95%confidence interval(95%CI):-0.88 to-0.12),BMI z-score(MD=-0.11,95%CI:-0.18 to-0.04),and BFP(MD=-1.69,95%CI:-2.97 to-0.42)compared to the usual care condition.Bicomponent treatment also significantly reduced BMI(MD=-0.28,95%CI:-0.54 to-0.04)and BMI z-score(MD=-0.07,95%CI:-0.12 to-0.02)compared to usual care.Conclusion:Interventions targeting multiple lifestyle components achieved greater reductions in children's BMI and BFP.Among single-component approaches,physical activity engagement emerged as the most effective.These findings should guide practitioners in recommending comprehensive lifestyle modifications for children.Moreover,children with higher initial BMI and body fat levels tend to exhibit more positive responses to lifestyle interventions aimed at managing obesity. 展开更多
关键词 Lifestyle intervention Body composition Preschool-aged children School-aged children
在线阅读 下载PDF
Plane Protection Enabling(002)Oriented Plating and Stripping Processes for Aqueous Zn-Ion Batteries
15
作者 Mengxuan Zhou Zhihong Luo +9 位作者 Jianwei Lu Tingting Xu Xiangqun Zhuge Dingren Zhou Laijun Liu Yibing Li Kun Luo Xinyu Li Weiwei Lei Dan Liu 《Energy & Environmental Materials》 2025年第6期112-121,共10页
Uniform deposition is a promising strategy to inhibit dendrite growth and corrosion of the Zn anode in cost-effective energy storage systems:aqueous Zn-ion batteries(AZIBs).Herein,we report a regulating Zn^(2+)ions di... Uniform deposition is a promising strategy to inhibit dendrite growth and corrosion of the Zn anode in cost-effective energy storage systems:aqueous Zn-ion batteries(AZIBs).Herein,we report a regulating Zn^(2+)ions dissolution/deposition method for achieving a highly reversible Zn anode.11-mercaptoundecanoic acid(MUA)as ligands was utilized to protect the(002)plane,benefiting from the strong affinity between the thiol group and Zn,with MUA anchoring in the form of Zn-S-RCOOH,which contributes to a stable interface for uniform deposition/deposition. 展开更多
关键词 (002) deposition DISSOLUTION plane protection Zn anode
在线阅读 下载PDF
Harnessing TLBO-Enhanced Cheetah Optimizer for Optimal Feature Selection in Cancer Data
16
作者 Bibhuprasad Sahu Amrutanshu Panigrahi +5 位作者 Abhilash Pati Ashis Kumar Pati Janmejaya Mishra Naim Ahmad Salman Arafath Mohammed Saurav Mallik 《Computer Modeling in Engineering & Sciences》 2025年第10期1029-1054,共26页
Metaheuristic optimization methods are iterative search processes that aim to efficiently solve complexoptimization problems. These basically find the solution space very efficiently, often without utilizing the gradi... Metaheuristic optimization methods are iterative search processes that aim to efficiently solve complexoptimization problems. These basically find the solution space very efficiently, often without utilizing the gradientinformation, and are inspired by the bio-inspired and socially motivated heuristics. Metaheuristic optimizationalgorithms are increasingly applied to complex feature selection problems in high-dimensional medical datasets.Among these, Teaching-Learning-Based optimization (TLBO) has proven effective for continuous design tasks bybalancing exploration and exploitation phases. However, its binary version (BTLBO) suffers from limited exploitationability, often converging prematurely or getting trapped in local optima, particularly when applied to discrete featureselection tasks. Previous studies reported that BTLBO yields lower classification accuracy and higher feature subsetvariance compared to other hybrid methods in benchmark tests, motivating the development of hybrid approaches.This study proposes a novel hybrid algorithm, BTLBO-Cheetah Optimizer (BTLBO-CO), which integrates the globalexploration strength of BTLBO with the local exploitation efficiency of the Cheetah Optimization (CO) algorithm. Theobjective is to enhance the feature selection process for cancer classification tasks involving high-dimensional data. Theproposed BTLBO-CO algorithm was evaluated on six benchmark cancer datasets: 11 tumors (T), Lung Cancer (LUC),Leukemia (LEU), Small Round Blue Cell Tumor or SRBCT (SR), Diffuse Large B-cell Lymphoma or DLBCL (DL), andProstate Tumor (PT).The results demonstrate superior classification accuracy across all six datasets, achieving 93.71%,96.12%, 98.13%, 97.11%, 98.44%, and 98.84%, respectively.These results validate the effectiveness of the hybrid approachin addressing diverse feature selection challenges using a Support Vector Machine (SVM) classifier. 展开更多
关键词 Cancer classification hybrid model teaching-learning-based optimization cheetah optimizer feature selection
在线阅读 下载PDF
Physical activity during COVID-19 pandemic:A 5-year retrospect
17
作者 Jeffrey A.Woods Noah T.Hutchinson +12 位作者 Scott K.Powers Mari Carmen Gomez-Cabrera Zsolt Radak Christiaan Leeuwenburgh Stefano Cacciatore Emanuele Marzetti Tianou Zhang Ronaldo Garza Corby Sidebottom Elizabeth Anderson J.Larry Durstine Junzhi Sun Li Li Ji 《Sports Medicine and Health Science》 2025年第6期405-418,共14页
The purpose of this article is to provide a follow-up review of the impact of the SARS-CoV-2 Disease or Coronavirus Disease 2019(COVID-19)pandemic on human health and the role of physical activity(PA)during the 5-year... The purpose of this article is to provide a follow-up review of the impact of the SARS-CoV-2 Disease or Coronavirus Disease 2019(COVID-19)pandemic on human health and the role of physical activity(PA)during the 5-year pandemic.We aim to cover the immune system,the cardiopulmonary system,the musculoskeletal system,and the central nervous system(brain function),particularly among older adults,college students,and individuals with post-acute sequelae of COVID-19(Long-COVID).The COVID-19 pandemic has given us many lessons,learned from the death of six million lives and tremendous disturbance to human life.First,we need to continue to investigate cellular and molecular mechanisms that mediate various organistic failures resulting from the viral infection.Such investigations are the only way to completely understand the etiology of the diseases and to develop new drugs and vaccines.The molecular pathways that transmit the signals of viral infection to each organ system are different requiring both basic and clinical research.Available evidence suggests that mitochondrial dysfunction,reduced microcirculation and latent immune activation play a major role,eventually impairing cardiovascular tolerance and peripheral bioenergetics.Second,the COVID-19 pandemic has manifested major disturbances to human lifestyles with reduced PA and exercise standing out as a major factor.Conversely,physical inactivity due to social confinement and mental/psychological stresses has been clearly linked to intensified pathogenic symptoms and amplification of adverse effects on multiple physiological systems.If not intervened,this interaction can lead to Long-COVID,a dangerous futile circle to cause systemic failure.Finally,the COVID-19 pandemic has exerted differential impacts on different populations.Thus,the strategy to develop and conduct to cope with the negativity of pandemic needs to be specific,flexible and tailored to fit different patient populations. 展开更多
关键词 Aging Brain Cardiac intolerance Covid-19 Immune system Long-COVID MUSCULOSKELETAL Physical activity
在线阅读 下载PDF
中国南方石笋氧同位素记录的重要意义 被引量:127
18
作者 程海 艾思本 +7 位作者 王先锋 汪永进 孔兴功 袁道先 张美良 林玉石 覃嘉铭 冉景丞 《第四纪研究》 CAS CSCD 北大核心 2005年第2期157-163,共7页
中国南部石笋氧同位素记录记载了重要的气候变化信息。应用石笋氧同位素记录时首先需要考虑检验石笋的平衡结晶生长,特别是重复性检验,以排除可能的偶然性或地方因素。中国南部重复性很好的南京葫芦洞和贵州董歌洞石笋氧同位素记录主要... 中国南部石笋氧同位素记录记载了重要的气候变化信息。应用石笋氧同位素记录时首先需要考虑检验石笋的平衡结晶生长,特别是重复性检验,以排除可能的偶然性或地方因素。中国南部重复性很好的南京葫芦洞和贵州董歌洞石笋氧同位素记录主要代表了当时的降水氧同位素信息。两洞的记录都显示,在冰期或冰段时期降水的氧同位素比间冰期或间冰段时期明显偏重。受夏季风强弱变化的控制,与目前亚洲季风降水氧同位素的季节变化相对应,在间冰期或间冰段时,ITCZ偏北,降水以夏季风的大规模大气环流下的对流降水为主,其氧同位素较轻;相反地,在冰期或冰段时,ITCZ偏南,降水以夏季风爆发前的锋面降水为主,其氧同位素较重。虽然尚有其他许多影响因素,亚洲季风的变化应是影响中国南部石笋氧同位素在冰期 /间冰期或冰段 /间冰段的尺度上变化的主导因素。但在更小的尺度上(例如小冰期),石笋氧同位素记录的解释则需要谨慎。虽然下最终结论为时尚早,但作为亚洲季风的两个组成部分的东亚季风和印度季风很可能是同步的,至少在冰期 /间冰期或冰段 /间冰段的尺度上是如此。基于上述研究,进一步提出亚洲夏季风强段 /弱段的概念 (AsianSummerMonsoonInterstadial/stadial, 或ASMI/ASMS),其在上个冰期中与格陵兰冰芯间冰段 展开更多
关键词 石笋 氧同位素 亚洲夏季风强/弱段 葫芦洞 董歌洞
在线阅读 下载PDF
MIS3晚期东亚季风强度和DO事件年龄 被引量:32
19
作者 赵侃 孔兴功 +1 位作者 程海 汪永进 《第四纪研究》 CAS CSCD 北大核心 2008年第1期177-183,共7页
基于神农架山宝洞石笋(SB46)的9个230Th年龄和326个氧同位素数据,建立了末次冰期32.2~26.7kaB.P.和17.0~15.4kaB.P.的东亚季风降水序列。该序列和同一洞穴全新世石笋记录的对比发现,在MIS3晚期东亚季风区可能存在极强夏季风降水事件,... 基于神农架山宝洞石笋(SB46)的9个230Th年龄和326个氧同位素数据,建立了末次冰期32.2~26.7kaB.P.和17.0~15.4kaB.P.的东亚季风降水序列。该序列和同一洞穴全新世石笋记录的对比发现,在MIS3晚期东亚季风区可能存在极强夏季风降水事件,相当于全新世季风强度,可能与岁差旋回太阳辐射及海陆水汽潜热释放增强有关。与葫芦洞石笋δ18O记录和格陵兰冰芯δ18O记录对比表明,东亚夏季风千年尺度气候振荡与高北纬地区海-气快速重组存在遥相关效应。山宝洞石笋年龄与葫芦洞石笋和格陵兰冰芯时标(SS09sea)在定年误差范围内基本一致,但山宝洞石笋与冰芯记录在DO事件的年龄、波形和持续时间上更为一致,不仅进一步说明了低纬季风气候与极地气温同步变化,而且有效地弥补了葫芦洞记录在这一时段的不足。 展开更多
关键词 MIS 3晚期 石笋 DO事件 东亚季风
在线阅读 下载PDF
东亚季风MIS3早期DO事件的亚旋回及全球意义 被引量:32
20
作者 刘殿兵 汪永进 +2 位作者 陈仕涛 程海 R.L.Edwards 《第四纪研究》 CAS CSCD 北大核心 2008年第1期169-176,共8页
根据湖北永兴洞石笋(YX51)10个U/Th年龄,470组氧、碳同位素数据建立了深海氧同位素3阶段(MIS3)早期57.7~35.6kaB.P.期间东亚夏季风演化时间序列。在发育时段,千年尺度δ^18O峰谷变化与高纬冰芯记录的Dansgaard-Oeschger(D... 根据湖北永兴洞石笋(YX51)10个U/Th年龄,470组氧、碳同位素数据建立了深海氧同位素3阶段(MIS3)早期57.7~35.6kaB.P.期间东亚夏季风演化时间序列。在发育时段,千年尺度δ^18O峰谷变化与高纬冰芯记录的Dansgaard-Oeschger(D0)事件一致;δ^18C呈现出与δ^18O正相关同步演化特征,但受区域环境影响,在事件内部细节上存在差异。区域对比表明,同一季风区的永兴洞和葫芦洞石笋δ^18O指示的季风降水同位素组成具有本质上一致性;高低纬记录对比显示,千年尺度的峰谷变化一一对应,反映热带辐合带(ITCZ)水汽传输能力、平均位置变化对东亚季风和高北纬气候具有重要影响。在DO13至DO15事件内部,永兴洞石笋δ^18O记录了显著的双峰特征,说明低纬季风强度变化和格陵兰冰芯δ^18O揭示的次级暖峰具有一致对应关系,指示大气快速传输机制在高低纬环境突变中起着重要作用。 展开更多
关键词 MIS 3阶段 石笋 DO事件 亚旋回
在线阅读 下载PDF
上一页 1 2 40 下一页 到第
使用帮助 返回顶部