期刊文献+
共找到154,424篇文章
< 1 2 250 >
每页显示 20 50 100
Tumor size discrepancy between endoscopic and pathological evaluations in colorectal endoscopic submucosal dissection
1
作者 Takeshi Onda Osamu Goto +11 位作者 Toshiaki Otsuka Yoshiaki Hayasaka Shun Nakagome Tsugumi Habu Yumiko Ishikawa Kumiko Kirita Eriko Koizumi Hiroto Noda Kazutoshi Higuchi Jun Omori Naohiko Akimoto Katsuhiko Iwakiri 《World Journal of Gastrointestinal Endoscopy》 2024年第3期136-147,共12页
BACKGROUND Tumor size impacts the technical difficulty and histological curability of colorectal endoscopic submucosal dissection(ESD);however,the preoperative evaluation of tumor size is often different from histolog... BACKGROUND Tumor size impacts the technical difficulty and histological curability of colorectal endoscopic submucosal dissection(ESD);however,the preoperative evaluation of tumor size is often different from histological assessment.Analyzing influential factors on failure to obtain an accurate tumor size evaluation could help prepare optimal conditions for safer and more reliable ESD.METHODS This was a retrospective study conducted at a single institution.A total of 377 lesions removed by colorectal ESD at our hospital between April 2018 and March 2022 were collected.We first assessed the difference in size with an absolute per-centage of the scaling discrepancy.Subsequently,we compared the clinicopatho-logical characteristics of the correct scaling group(>-33%and<33%)with that of the incorrect scaling group(<-33%or>33%),which was further subdivided into the underscaling group(-33%or less of the discrepancy)and overscaling group(33%or more of the discrepancy),respectively.As secondary outcome measures,parameters on size estimation were compared between the underscaling and correct scaling groups,as well as between the overscaling and correct scaling groups.Finally,multivariate analysis was performed in terms of the following relevant parameters on size estimation:Pathological size,location,and possible influential factors(P<0.1)in the univariate analysis.RESULTS The mean of absolute percentage in the scaling discordance was 21%,and 91 lesions were considered to be incorrectly estimated in size.The incorrect scaling was significantly remarkable in larger lesions(40 mm vs 28 mm;P<0.001)and less experience(P<0.001),and these two factors were influential on the underscaling(75 lesions;P<0.001).Conversely,compared with the correct scaling group,16 lesions in the overscaling group were significantly small(20 mm vs 28 mm;P<0.001),and the small lesion size was influential on the overscaling(P=0.002).CONCLUSION Lesions indicated for colorectal ESD tended to be underestimated in large tumors,but overestimated in small ones.This discrepancy appears worth understanding for optimal procedural preparation. 展开更多
关键词 Endoscopic submucosal dissection Colorectal tumor Tumor size size estimation size discrepancy
下载PDF
Comparative efficacy of hyperbaric bupivacaine vs hyperbaric ropivacaine in spinal anesthesia for cesarean section:A metaanalysis
2
作者 Rishi Anand Deb Sanjay Nag +3 位作者 Roushan Patel Prashant Sharma Vamsi Krishna Uppalapati Umesh Kumar Singh 《World Journal of Methodology》 2025年第2期154-165,共12页
BACKGROUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential alter-native.This meta-analysis compares the effic... BACKGROUND Intrathecal bupivacaine is the traditional anesthetic drug used in spinal anesthesia for caesarean sections(CSs),but ropivacaine has emerged as a potential alter-native.This meta-analysis compares the efficacy and safety of intrathecal hyper-baric bupivacaine vs hyperbaric ropivacaine for cesarean sections.AIM To systematically evaluate and compare the efficacy and safety of intrathecal hyperbaric bupivacaine and hyperbaric ropivacaine for spinal anesthesia in CSs.METHODS A thorough search of electronic databases was carried out to find pertinent randomized controlled trials(RCTs)comparing intrathecal hyperbaric ropi-vacaine and hyperbaric bupivacaine during CSs.PubMed,Cochrane database,Google Scholar,and Scopus were searched,and papers from January 2000 to January 2024 were deemed eligible and filtered using predetermined inclusion and exclusion criteria.Studies were assessed for methodological quality,and data were extracted for time to adequate anesthesia(sensory and motor blockade),duration of sensory and motor block,hemodynamic changes and side effect profile.The standardized mean difference with 95%CI was used for continuous data.Dichotomous variables were assessed using the Mantel-Haenszel test and the random effect model to compute the odds ratio.RESULTS Total 8 RCTs were selected from a pool of 119 search results for meta-analysis.The meta-analysis evaluated pooled effect sizes and assessed heterogeneity among the studies.The primary objective was to compare key outcomes to identify any significant variances in efficacy and safety profiles between two local anesthetics.The analysis revealed that the difference in the onset of sensory blockade between the two local anesthetics was statistically insignificant(P=0.1586).However,the onset of motor blockade appeared to be faster with bupivacaine(P=0.03589).Additionally,the regression of sensory and motor blockade occurred earlier in the ropivacaine group.Furthermore,the duration of the first analgesic effect was shorter with a significance level of P<0.05.Regarding side effects profile,including hypotension,nausea,and shivering,the study did not observe any significant differences between the two groups.CONCLUSION This meta-analysis offers insights into the effectiveness and safety of hyperbaric bupivacaine vs ropivacaine for cesarean sections.Hyperbaric ropivacaine had a comparable safety profile and faster regression of sensory and motor blockade than hyperbaric bupivacaine,perhaps aiding early mobilization of parturient and facilitating mother-child bonding.Choosing ropivacaine may offer benefits beyond efficacy for cesarean section patients and short surgical procedures. 展开更多
关键词 ROPIVACAINE BUPIVACAINE ANESTHESIA SPINAL Cesarean section META-ANALYSIS
下载PDF
Large-for-size syndrome prophylaxis in infant liver recipients with low body mass
3
作者 Konstantin Semash Timur Dzhanbekov 《World Journal of Transplantation》 2025年第1期72-85,共14页
Transplantation of the left lateral section(LLS)of the liver is now an established practice for treating advanced diffuse and unresectable focal liver diseases in children,with variants of the LLS primarily used in in... Transplantation of the left lateral section(LLS)of the liver is now an established practice for treating advanced diffuse and unresectable focal liver diseases in children,with variants of the LLS primarily used in infants.However,the surgical challenge of matching the size of an adult donor's graft to the volume of a child's abdomen remains significant.This review explores historical developments,various approaches to measuring the required functional liver mass,and techniques to prevent complications associated with large-for-size grafts in infants. 展开更多
关键词 Pediatric liver transplantation Large-for-size syndrome Preoperative evaluation of donor and recipient Liver volumetry Monosegmental transplantation Left lateral sector graft Reduced size liver graft Abdominal wall reconstruction Liver transplantation Liver resection
下载PDF
Molecular Dissection of Relationship Between Seedling Characteristics and Seed Size in Rice 被引量:8
4
作者 崔克辉 彭少兵 +2 位作者 邢永忠 余四斌 徐才国 《Acta Botanica Sinica》 CSCD 2002年第6期702-707,共6页
Seedling characteristics such as leaf emergency, chlorophyll content, and height are important for early growth and also associated with seed size. Quantitative trait loci (QTLs) for rice (Oryza sativa L.) seedling ch... Seedling characteristics such as leaf emergency, chlorophyll content, and height are important for early growth and also associated with seed size. Quantitative trait loci (QTLs) for rice (Oryza sativa L.) seedling characteristics (leaf length, chlorophyll content, seedling height) and seed size were identified with an attempt to explore the relationship between seedling characteristics and seed size, using a recombinant inbred population derived from a cross between Zhenshan 97A and Minghui 63. Two, one, five, four, four, and nine QTLs were detected for chlorophyll a content, total chlorophyll, length of the second seedling leaf, length of the third seedling leaf, seedling height, and seed size, respectively. The results indicated that four QTLs for seed size and four QTLs for seedling characteristics shared several similar regions (G359-RG532, C567-RG236, RZ403-R19, C371-C405a), respectively, suggesting a close association between seedling characteristics and seed size. Several chromosomal regions influencing seed size, however, had no effects on seedling characteristics, suggesting that it was possible to improve seedling vigor without increasing grain size. 展开更多
关键词 QTL mapping seedling characteristics seed size RICE
下载PDF
Size effect on longitudinal MOE of microtomed wood sections and relevant theoretical explanation 被引量:2
5
作者 YU Yan JIANG Ze-hui TIAN Gen-lin 《Forestry Studies in China》 CAS 2009年第4期243-248,共6页
It has been repeatedly observed that the mechanical properties of microtomed wood sections are significantly lower than those of samples of normal size, but few investigations have been conducted to deal with this top... It has been repeatedly observed that the mechanical properties of microtomed wood sections are significantly lower than those of samples of normal size, but few investigations have been conducted to deal with this topic, especially based on theoretical approaches. We measured the longitudinal MOE of Chinese fir on microtomed sections ranging in thickness from 70 to 200 μm and compared these with the values of samples of normal size. The results indicate that the MOE of microtomed wood sections increases with thickness from 70 to 200 μm, but is significantly less than that of normal samples. A size effect coefficient of 2.63 is inferred based on statistical data for samples of normal size and 200 μm thick microtomed sections. Finally, an explanation based on a complete shear restraint model of cell walls and a single fiber multi-ply model is proposed for the size effect on stiffness of microtomed wood sections. 展开更多
关键词 a complete shear restraint model microtomed wood sections a single fiber multi-ply model size effect
下载PDF
ENVIRONMENTAL EVOLUTION OF ORDOS DESERT IN CHINA SINCE 1.1MA B. P. AS INDICATED BY YULIN STRATIGRAPHICAL SECTION AND ITS GRAIN-SIZE ANALYSIS RESULTS 被引量:4
6
作者 LIBao-sheng GAOShang-yu +1 位作者 DONGGuang-rong JINHe-ling 《Chinese Geographical Science》 SCIE CSCD 2005年第1期34-41,共8页
Yulin section is a typical sedimentary record for reflecting the environmental evolution of Ordos Desert, China in the past 1.1Ma. By analyzing its sequence and grain-size composition some views have been put forward ... Yulin section is a typical sedimentary record for reflecting the environmental evolution of Ordos Desert, China in the past 1.1Ma. By analyzing its sequence and grain-size composition some views have been put forward in this paper as follows. The layers of sand, loess and palaeosol in Yulin section were respectively formed by wind and the pedogenesis on parent material of the sand and loess. Since 1.1Ma B. P., Ordos Desert has alternately experienced 11 stages of shifting dunes under extreme cold-dry climatic environment, 7 stages of fixed and semi-fixed dunes and 8 stages of dust (loess) under cold-dry climatic condition; and the pedogenesis environment under 15 times of warm-humid climate and 3 times of temperate-humid climate (brownish-drab soils and black soils formed respectively). The aeolian sand had already existed in Ordos Desert at latest by 1.1Ma B. P., and from that time on it has undergone a series of alternative processes of shifting sands, fixed and semi-fixed dunes, loess and soils. Ordos Desert has been situated in the transitional belt of the Mongolian High Pressure and margin of the southeast summer monsoon since 1.1Ma B. P., and influenced repeatedly by migration of the lithofacies belts of shifting sands, fixed and semi-fixed dunes, loess and soils, which have been caused by the climatic fluctuations of glacial and interglacial periods. 展开更多
关键词 Ordos Desert Yulin stratigraphical section past 1.1Ma grain-sizecomposition environment evolution
下载PDF
Radiofrequency ablation is an inferior option to liver resection for solitary hepatocellular carcinoma≤5 cm without cirrhosis:A population-based study with stratification by tumor size 被引量:1
7
作者 Song-Chen Dong Dou-Sheng Bai +4 位作者 Fu-An Wang Sheng-Jie Jin Chi Zhang Bao-Huan Zhou Guo-Qing Jiang 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2023年第6期605-614,共10页
Background:About 10%-20%of all individuals who develop hepatocellular carcinoma(HCC)do not have cirrhosis.Comparisons are rarely reported regarding the effectiveness of radiofrequency ablation(RFA)and liver resection(... Background:About 10%-20%of all individuals who develop hepatocellular carcinoma(HCC)do not have cirrhosis.Comparisons are rarely reported regarding the effectiveness of radiofrequency ablation(RFA)and liver resection(LR)in survival of HCC without cirrhosis and stratification by tumor size≤5 cm.Methods:We used the Surveillance,Epidemiology,and End Results(SEER)database and identified 1505 patients with a solitary HCC tumor≤5 cm who underwent RFA or LR during 2004-2015.Patients were classified into non-cirrhosis and cirrhosis groups and each group was categorized into three subgroups,according to tumor size(≤30 mm,31-40 mm,41-50 mm).Results:In patients without cirrhosis,LR showed better 5-year HCC cancer-specific survival than RFA in all tumor size subgroups(≤30 mm:82.51%vs.56.42%;31-40 mm:71.31%vs.46.83%;41-50 mm:74.7%vs.37.5%;all P<0.05).Compared with RFA,LR was an independent protective factor for HCC cancer-specific survival in multivariate Cox analysis[≤30 mm:hazard ratio(HR)=0.533,95%confidence interval(CI):0.313-0.908;31-40 mm:HR=0.439,95%CI:0.201-0.957;41-50 mm:HR=0.382;95%CI:0.159-0.916;all P<0.05].In patients with cirrhosis,for both tumor size≤30 mm and 31-40 mm groups,there were no significant survival differences between RFA and LR in multivariate analysis(all P>0.05).However,in those with tumor size 41-50 mm,LR showed significantly better 5-year HCC cancer-specific survival than RFA in both univariate(54.72%vs.23.06%;P<0.001)and multivariate analyses(HR=0.297;95%CI:0.136-0.648;P=0.002).Conclusions:RFA is an inferior treatment option to LR for patients without cirrhosis who have a solitary HCC tumor≤5 cm. 展开更多
关键词 Cirrhosis Liver resection Radiofrequency ablation Hepatocellular carcinoma Tumor size
下载PDF
Endoscopic mucosal resection-precutting vs conventional endoscopic mucosal resection for sessile colorectal polyps sized 10-20 mm 被引量:2
8
作者 Xue-Qun Zhang Jian-Zhong Sang +5 位作者 Lei Xu Xin-Li Mao Bo Li Wan-Lin Zhu Xiao-Yun Yang Chao-Hui Yu 《World Journal of Gastroenterology》 SCIE CAS 2022年第45期6397-6409,共13页
BACKGROUND The optimal method to remove sessile colorectal lesions sized 10-20 mm remains uncertain.Piecemeal and incomplete resection are major limitations in current practice,such as endoscopic mucosal resection(EMR... BACKGROUND The optimal method to remove sessile colorectal lesions sized 10-20 mm remains uncertain.Piecemeal and incomplete resection are major limitations in current practice,such as endoscopic mucosal resection(EMR)and cold or hot snare polypectomy.Recently,EMR with circumferential precutting(EMR-P)has emerged as an effective technique,but the quality of current evidence in comparative studies of conventional EMR(CEMR)and EMR-P is limited.AIM To investigate whether EMR-P is superior to CEMR in removing sessile colorectal polyps.METHODS This multicenter randomized controlled trial involved seven medical institutions in China.Patients with colorectal polyps sized 10-20 mm were enrolled and randomly assigned to undergo EMR-P or CEMR.EMR-P was performed following submucosal injection,and a circumferential mucosa incision(precutting)was conducted using a snare tip.Primary outcomes included a comparison of the rates of en bloc and R0 resection,defined as one-piece resection and one-piece resection with histologically assessed clear margins,respectively.RESULTS A total of 110 patients in the EMR-P group and 110 patients in the CEMR group were finally evaluated.In the per-protocol analysis,the proportion of en bloc resections was 94.3%[95%confidence interval(CI):88.2%-97.4%]in the EMR-P group and 86%(95%CI:78.2%-91.3%)in the CEMR group(P=0.041),while subgroup analysis showed that for lesions>15 mm,EMR-P also resulted in a higher en bloc resection rate(92.0%vs 58.8%P=0.029).The proportion of R0 resections was 81.1%(95%CI:72.6%-87.4%)in the EMR-P group and 76.6%(95%CI:68.8%-84.4%)in the CEMR group(P=0.521).The EMR-P group showed a longer median procedure time(6.4 vs 3.0 min;P<0.001).No significant difference was found in the proportion of patients with adverse events(EMR-P:9.1%;CEMR:6.4%;P=0.449).CONCLUSION In this study,EMR-P served as an alternative to CEMR for removing nonpedunculated colorectal polyps sized 10-20 mm,particularly polyps>15 mm in diameter,with higher R0 and en bloc resection rates and without increasing adverse events.However,EMR-P required a relatively longer procedure time than CEMR.Considering its potential benefits for en bloc and R0 resection,EMR-P may be a promising technique in colorectal polyp resection. 展开更多
关键词 Colorectal polyps Medium size POLYPECTOMY Endoscopic mucosal resection with circumferential precutting Conventional endoscopic mucosal resection
下载PDF
Grain-size Characteristics and Climate Variability in TMS5e Sequence of Tumen Section in Southern Tengger Desert,Northwestern China 被引量:2
9
作者 WEN Xiaohao LI Baosheng +4 位作者 WANG Fengnian ZHENG Yanming NIU Dongfeng SI Yuejin OU Xianjiao 《Chinese Geographical Science》 SCIE CSCD 2012年第1期48-62,共15页
The TMS5e sequence from the Tumen section, at the southern edge of Tengger Desert in the northwestern China, is synchronous with Marine Isotope Stage 5e (MIS5e). It consists of 16 layers of aeolian dune sands, 11 la... The TMS5e sequence from the Tumen section, at the southern edge of Tengger Desert in the northwestern China, is synchronous with Marine Isotope Stage 5e (MIS5e). It consists of 16 layers of aeolian dune sands, 11 layers of lacustrine loess-like facies, and 5 layers of lacustrine facies. The results of grain-size analysis shows that the pa- laeo-mobile dune sands, palaeo-fixed to semi-fixed dune sands and loess-like sandy loams are mainly composed of sands, ranging from 70% to 96%; their silt contents ranged from 4% to 20%, and their clay contents ranged from 1% to 5%; the climate under which the aeolian dune sands were deposited is similar to that under which modern mobile dune sands form, which is caused by the dominance of the cold, dry East Asian winter monsoon. In contrast, the lacustrine loess-like facies and lacustrine facies had a lower sand contents than those of the three aeolian dune sands, but have higher silt and clay contents, most of their sand content ranged from 30% to 60%, their silt contents ranged from 35% to 55%, and their clay contents ranged from 6% to 20%. The lacustrine loess-like facies and lacustrine facies formed under the influence of the warm, humid East Asian summer monsoon based on their similarity with modern sediments. The grain-size indicator Mz (mean grain diameter) and the SC/D value in the TMS5e sequence indicate climatic insta- bility at the southern edge of the Tengger Desert during MIS5e, with at least 14 fluctuations between a warm, humid climate and a cold, dry climate, divided into five stages: TMS5e5 (139 kyr to 129.3 kyr B.P.), TMS5e4 (129.3 kyr to 124 kyr B.P.), TMS5e3 (124 kyr to 119.5 kyr B.P.), TMS5e2 (119.5 kyr to 116.5 kyr B.P.), and TMS5el (116.5 kyr to 113.7 kyr B.P.). These correspond roughly to MIS5e5, MIS5e4, MIS5e3, MIS5e2, and MIS5el, respectively, in the GRIP ice core data. 展开更多
关键词 Tengger Desert Tureen section TMS5e sequence grain-size characteristics palaeoclimate reconstruction Marine Isotope Stage 5e (MIS5e)
下载PDF
Experimental study for the particle size distribution of mine spoil pile cross section
10
作者 JIANG Li-guo Liang Bing LU Xiu-sheng 《Journal of Coal Science & Engineering(China)》 2010年第4期415-418,共4页
The aim of the experiment is to analyze and view the distribution of gangue withdifferent particle sizes in mine spoil pile cross section.According to the Dimensionalmethod,'Pi'theorem was employed first to ab... The aim of the experiment is to analyze and view the distribution of gangue withdifferent particle sizes in mine spoil pile cross section.According to the Dimensionalmethod,'Pi'theorem was employed first to abbreviate ten physical and mechanical parametersto three dimensionless groups, and then the similarity criterion and coefficient ofthe experiment were determined and calculated based on particle size distribution curve.The similarity model was designed and constructed to represent the process of the minespoil pile.The profile of the final model shows that the small sized particles mainly composethe upper zone of the mine spoil pile, while the bottom of the pile is dominated bybigger sized particles, and the intermediate section presents a zigzag stripe cross-beddingstructure which is composed by small-medium scale particles and medium-large scaleparticles.Each stripe has two critical angles: one is the angle in which gangue particlescan maintain their stability condition, with approximate range from 24° to 26°; and theother is the angle in which particles can stop gliding downwards, approximately varyingfrom 34° to 36°. 展开更多
关键词 mine spoil pile particle size distribution cross section similarity model di- mensional analysis
下载PDF
Extended hepatectomy with segments Ⅰand Ⅶ as resection remnant:a simple model for small-for-size injuries in pigs 被引量:3
11
作者 Qiang Xia,Tian-Fei Lu,Zhi-Hua Zhou,Ling-Xiang Hu,Jun Ying,De-Zhong Ding, Xiao-Song Chen and Jian-Jun Zhang Transplantation Center and Department of Clinical Laboratory ,Renji Hospital,School of Medicine,Shanghai Jiaotong University,Shanghai 200127,China Tyco Clinical Institute,Shanghai 200040,China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2008年第6期601-607,共7页
BACKGROUND:Small-for-size(SFS)syndrome is an important clinical problem after living donor liver transplantation,split liver transplantation or extended hepatectomy.The uncertainty of the mechanisms and treatments of ... BACKGROUND:Small-for-size(SFS)syndrome is an important clinical problem after living donor liver transplantation,split liver transplantation or extended hepatectomy.The uncertainty of the mechanisms and treatments of SFS syndrome urges surgeons to establish effective models for SFS syndrome. METHODS:A new porcine model for SFS syndrome based on extended hepatectomy was established.Portal pressure gradient was observed before and after the surgery,and venous sampling for estimation of alanine aminotransferase, total bilirubin,and international normalized ratio was continued on a daily basis. RESULTS:Although the external morphology of the porcine liver differs from that of human being,segmental anatomy is remarkably similar in term of its vascularity and biliary tree.Extended hepatectomy with segmentsⅠand Ⅶas resection remnant(about 20%of total liver volume) resulted in similar survival rates,blood liver function tests,and elevated portal pressure gradient as clinical SFS syndrome. CONCLUSIONS:The extended hepatectomy based new model can easily be reproduced,with few costs and surgical complications.Clinical SFS syndrome can easily be simulated by this new model,which is a useful tool for studying SFS syndrome-related liver injuries,especially portal overperfusion and hypertension. 展开更多
关键词 HEPATECTOMY small-for-size syndrome
下载PDF
Population size estimates based on GPS telemetry 被引量:1
12
作者 Yu-Xuan Fan Pu-Zheng Xie +5 位作者 Chi Ma Ting Chen Xiao Ye Hua-Lin Xu Qiong Yang Peng-Fei Fan 《Zoological Research》 SCIE CSCD 2024年第1期36-38,共3页
DEAR EDITOR,Accurate estimation of population size is a crucial issue in wildlife population ecology and conservation.While Global Positioning System(GPS)collars are well recognized as an effective method for monitori... DEAR EDITOR,Accurate estimation of population size is a crucial issue in wildlife population ecology and conservation.While Global Positioning System(GPS)collars are well recognized as an effective method for monitoring wildlife behavior,their application in direct wildlife population size estimation remains underutilized.In this study,GPS telemetry was employed to survey a rhesus macaque(Macaca mulatta)population on Neilingding Island in Guangdong,China.From May 2021 to April 2022,32 macaques across nine groups were fitted with GPS collars,producing a dataset of 109739 location fixes.Analyzing data from all tracked individuals revealed the annual home ranges of the nine groups. 展开更多
关键词 China ISLAND size
下载PDF
240 nm AlGaN-based deep ultraviolet micro-LEDs:size effect versus edge effect 被引量:2
13
作者 Shunpeng Lu Jiangxiao Bai +6 位作者 Hongbo Li Ke Jiang Jianwei Ben Shanli Zhang Zi-Hui Zhang Xiaojuan Sun Dabing Li 《Journal of Semiconductors》 EI CAS CSCD 2024年第1期55-62,共8页
240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge ef... 240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge effects.Here,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μm.Thereinto,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light extraction.Most notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector design.However,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized ones.The underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further shrinking.Moreover,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa edge.These findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs. 展开更多
关键词 ALGAN deep ultraviolet micro-LEDs light extraction efficiency size effect edge effect
下载PDF
Influence of Section Size of Telescopic Boom on Stability
14
作者 SHE Zhanjiao YAO Fenglin +2 位作者 WANG Junfei ZHANG Yi JIANG Jun 《International Journal of Plant Engineering and Management》 2023年第4期213-231,共19页
The telescopic boom is the main bearing force component of the crane.The rationality of the design will directly affect the performance of the machine and safety.The telescopic boom is a typical thin-walled plate and ... The telescopic boom is the main bearing force component of the crane.The rationality of the design will directly affect the performance of the machine and safety.The telescopic boom is a typical thin-walled plate and shell structure.Its main form of damage is the occurrence of buckling,resulting in decreased carrying capacity,or even a security incident.In order to meet the lifting weight and height,to ensure the stability of the telescopic boom has become a major problem of the designer.There are many factors that affect the critical load of the telescopic boom,including support method,inertia moment,length and material.When the support mode,material and length are determined,the maximum factor affecting the buckling critical load is the inertia moment.In this paper,the influence of the section size on the buckling critical load of the telescopic boom is analyzed by using the inertia moment of section method ande finite element method.And the sensitivity analysis is carried out on this basis.The results of the analysis can provide designers with design reference basis.Then a reasonable cross-sectional size can be used to improve the buckling resistance capacity of the telescopic boom. 展开更多
关键词 telescopic boom buckling stability sensitivity analysis section size finite element
下载PDF
Effect of intraoperative injection of esketamine on postoperative analgesia and postoperative rehabilitation after cesarean section 被引量:1
15
作者 Hong-Zhuan Chen Yi Gao +4 位作者 Ke-Ke Li Li An Jing Yan Hong Li Jin Zhang 《World Journal of Clinical Cases》 SCIE 2024年第28期6195-6203,共9页
BACKGROUND Following cesarean section,a significant number of women encounter moderate to severe pain.Inadequate management of acute pain post-cesarean section can have far-reaching implications,adversely impacting ma... BACKGROUND Following cesarean section,a significant number of women encounter moderate to severe pain.Inadequate management of acute pain post-cesarean section can have far-reaching implications,adversely impacting maternal emotional wellbeing,daily activities,breastfeeding,and neonatal care.It may also impede maternal organ function recovery,leading to escalated opioid usage,heightened risk of postpartum depression,and the development of chronic postoperative pain.Both the Chinese Enhanced Recovery After Surgery(ERAS)guidelines and the American ERAS Society guidelines consistently advocate for the adoption of multimodal analgesia protocols in post-cesarean section pain management.Esketamine,functioning as an antagonist of the N-Methyl-D-Aspartate receptor,has been validated for pain management in surgical patients and has exhibited effectiveness in depression treatment.Research has suggested that incorporating esketamine into postoperative pain management via pain pumps can lead to improvements in short-term depression and pain outcomes.This study aims to assess the efficacy and safety of administering a single dose of esketamine during cesarean section.AIM To investigate the effect of intraoperative injection of esketamine on postoperative analgesia and postoperative rehabilitation after cesarean section.METHODS A total of 315 women undergoing elective cesarean section under combined spinal-epidural anesthesia were randomized into three groups:low-dose esketamine(0.15 mg/kg),high-dose esketamine(0.25 mg/kg),and control(saline).Postoperative Visual Analog Scale(VAS)scores were recorded at 6 hours,12 hours,24 hours,and 48 hours.Edinburgh Postnatal Depression Scale(EPDS)scores were noted on 2 days,7 days and 42 days.Ramsay sedation scores were assessed at specified intervals post-injection.Postoperative adverse reactions were also recorded.RESULTS Low-dose group and high-dose group compared to control group,had significantly lower postoperative VAS pain scores at 6 hours 12 hours,and 24 hours(P<0.05),with reduced analgesic usage(P<0.05).EPDS scores and postpartum depression rates were significantly lower on 2 days and 7 days(P<0.05).No significant differences in first exhaust and defecation times were observed(P>0.05),but ambulation times were shorter(P<0.05).Ramsay scores were higher at 5 minutes,15 minutes,and upon room exit(P<0.05).Low-dose group and high-dose group had higher incidences of hallucination,lethargy,and diplopia within 2 hours(P<0.05),and with low-dose group had lower incidences of hallucination,lethargy,and diplopia than high-dose group(P<0.05).CONCLUSION Esketamine enhances analgesia and postpartum recovery;a 0.15 mg/kg dose is optimal for cesarean sections,balancing efficacy with minimized adverse effects. 展开更多
关键词 MATERNITY Cesarean section DEPRESSION Esketamine Postoperative analgesia
下载PDF
Efficient Electromagnetic Wave Absorption and Thermal Infrared Stealth in PVTMS@MWCNT Nano‑Aerogel via Abundant Nano‑Sized Cavities and Attenuation Interfaces 被引量:1
16
作者 Haoyu Ma Maryam Fashandi +5 位作者 Zeineb Ben Rejeb Xin Ming Yingjun Liu Pengjian Gong Guangxian Li Chul B.Park 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期370-383,共14页
Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT... Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work. 展开更多
关键词 Nano-pore size Heterogeneous interface Electromagnetic wave absorption Thermal infrared stealth Nano-aerogel
下载PDF
A data-driven model of drop size prediction based on artificial neural networks using small-scale data sets 被引量:1
17
作者 Bo Wang Han Zhou +3 位作者 Shan Jing Qiang Zheng Wenjie Lan Shaowei Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期71-83,共13页
An artificial neural network(ANN)method is introduced to predict drop size in two kinds of pulsed columns with small-scale data sets.After training,the deviation between calculate and experimental results are 3.8%and ... An artificial neural network(ANN)method is introduced to predict drop size in two kinds of pulsed columns with small-scale data sets.After training,the deviation between calculate and experimental results are 3.8%and 9.3%,respectively.Through ANN model,the influence of interfacial tension and pulsation intensity on the droplet diameter has been developed.Droplet size gradually increases with the increase of interfacial tension,and decreases with the increase of pulse intensity.It can be seen that the accuracy of ANN model in predicting droplet size outside the training set range is reach the same level as the accuracy of correlation obtained based on experiments within this range.For two kinds of columns,the drop size prediction deviations of ANN model are 9.6%and 18.5%and the deviations in correlations are 11%and 15%. 展开更多
关键词 Artificial neural network Drop size Solvent extraction Pulsed column Two-phase flow HYDRODYNAMICS
下载PDF
Clinical nursing value of predictive nursing in reducing complications of pregnant women undergoing short-term massive blood transfusion during cesarean section 被引量:1
18
作者 Li Cheng Li-Ping Li +2 位作者 Yuan-Yuan Zhang Fang Deng Ting-Ting Lan 《World Journal of Clinical Cases》 SCIE 2024年第1期51-58,共8页
BACKGROUND Cesarean hemorrhage is one of the serious complications,and short-term massive blood transfusion can easily cause postoperative infection and physical stress response.However,predictive nursing intervention... BACKGROUND Cesarean hemorrhage is one of the serious complications,and short-term massive blood transfusion can easily cause postoperative infection and physical stress response.However,predictive nursing intervention has important clinical significance for it.AIM To explore the effect of predictive nursing intervention on the stress response and complications of women undergoing short-term mass blood transfusion during cesarean section(CS).METHODS A clinical medical record of 100 pregnant women undergoing rapid mass blood transfusion during sections from June 2019 to June 2021.According to the different nursing methods,patients divided into control group(n=50)and observation group(n=50).Among them,the control group implemented routine nursing,and the observation group implemented predictive nursing intervention based on the control group.Moreover,compared the differences in stress res-ponse,complications,and pain scores before and after the nursing of pregnant women undergoing rapid mass blood transfusion during CS.RESULTS The anxiety and depression scores of pregnant women in the two groups were significantly improved after nursing,and the psychological stress response of the observation group was significantly lower than that of the control group(P<0.05).The heart rate and mean arterial pressure(MAP)of the observation group during delivery were lower than those of the control group,and the MAP at the end of delivery was lower than that of the control group(P<0.05).Moreover,different pain scores improved significantly in both groups,with the observation group considerably less than the control group(P<0.05).After nursing,complications such as skin rash,urinary retention,chills,diarrhea,and anaphylactic shock in the observation group were 18%,which significantly higher than in the control group(4%)(P<0.05).CONCLUSION Predictive nursing intervention can effectively relieve the pain,reduce the incidence of complications,improve mood and stress response,and serve as a reference value for the nursing of women undergoing rapid mass transfusion during CS. 展开更多
关键词 Predictive care Rapid mass blood transfusion Cesarean section Stress response COMPLICATIONS
下载PDF
Effects of spot size on the operation mode of Ga As photoconductive semiconductor switch employing extrinsic photoconductivity 被引量:1
19
作者 韦金红 李嵩 +5 位作者 陈红 曾凡正 贾成林 付泽斌 葛行军 钱宝良 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第5期91-99,共9页
To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insul... To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated experimentally.It is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation modes.On this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing mechanisms.Results indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes. 展开更多
关键词 GaAs PCSS operation mode spot size on-state performances two-channel model domain evolution
下载PDF
Proper interpretation of sectional analysis results 被引量:1
20
作者 Juyuan Zheng Yuli Huang Zhe Qu 《Earthquake Research Advances》 CSCD 2024年第2期65-71,共7页
Displacement control algorithms commonly used to evaluate axial force-bending moment(PM)diagrams may lead to incorrect interpretations of the strength envelopes for asymmetric sections.This paper aims to offer valuabl... Displacement control algorithms commonly used to evaluate axial force-bending moment(PM)diagrams may lead to incorrect interpretations of the strength envelopes for asymmetric sections.This paper aims to offer valuable insights by comparing existing displacement control algorithms with a newly proposed force control algorithm.The main focus is on the PM diagrams of three example sections that exhibit varying degrees of asymmetry.The comparative study indicates that conventional displacement control algorithms inevitably introduce non-zero out-of-plane bending moments.The reported PM diagram in such cases erroneously neglects the out-of-plane moment and fails to represent the strength envelope accurately.This oversight results in significant and unconservative errors when verifying the strength of asymmetric sections. 展开更多
关键词 Fiber section model Axial force-moment interaction diagram Limit state Failure surface
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部