期刊文献+
共找到11,221篇文章
< 1 2 250 >
每页显示 20 50 100
TfOH-Catalyzed O-H Insertion of Carboxylic Acids with α-Aryl Diazoesters
1
作者 Chen Guifang Li Hongqiang Zeng Xingrong 《有机化学》 北大核心 2025年第7期2537-2544,共8页
An efficient TfOH-catalyzed O—H insertion reaction of α-aryl diazoesters with carboxylic acids is reported.This metal-free protocol provides an operationally simple method for a one-pot assembly of diverse α-acylox... An efficient TfOH-catalyzed O—H insertion reaction of α-aryl diazoesters with carboxylic acids is reported.This metal-free protocol provides an operationally simple method for a one-pot assembly of diverse α-acyloxy esters in moderate to high yields with a broad substrate scope.All starting materials are readily available,and the reactions can be conducted in the open air at room temperature. 展开更多
关键词 carboxylic acids α-aryl diazoesters TfOH O-H insertion
原文传递
Blue Light-Induced Formal Insertion Reaction ofα-Siloxy Carbene into C-H Bond of 1,3-Diketones
2
作者 Jiang Xinyu Zhang Xinke +1 位作者 Fang Xi Xu Xinfang 《有机化学》 北大核心 2025年第6期2231-2238,共8页
A blue light-induced formal insertion reaction ofα-siloxy carbene into the C—H bond of 1,3-diketones has been reported.Under the irradiation of blue light,acylsilane converts toα-siloxy carbene,which then undergoes... A blue light-induced formal insertion reaction ofα-siloxy carbene into the C—H bond of 1,3-diketones has been reported.Under the irradiation of blue light,acylsilane converts toα-siloxy carbene,which then undergoes formal C—H bond insertion reaction with the enol form of 1,3-diketone.This method uses readily available and relative stable acylsilane as car-bene precursor,which features a simple and metal-free approach under mild conditions.Moreover,the synthetic potential of this protocol has been demonstrated by performing the reaction on a gram scale with comparable high yield. 展开更多
关键词 photoinduction α-siloxy carbene 1 3-diketone C-H bond insertion reaction
原文传递
Rhodium-catalyzed site-selective cross-couplings of indoles and pyridotriazoles through carbene insertion
3
作者 Hua Tian Xin Yang +2 位作者 Ge Shi Heng Xu Yi Dong 《Chinese Chemical Letters》 2025年第7期302-307,共6页
The switchable cross-coupling of indoles and pyridotriazoles through carbene insertion at C_(2)-or C_(3)-positon has been developed in this paper.This highly site-selective C-H carbenoid functionalization is determine... The switchable cross-coupling of indoles and pyridotriazoles through carbene insertion at C_(2)-or C_(3)-positon has been developed in this paper.This highly site-selective C-H carbenoid functionalization is determined by both the Rh-catalyst species and auxiliary groups.[Cp∗RhCl_(2)]_(2) and coordinating pyrimidyl group direct the C-H carbenoid functionalization to occur at the C_(2)-position,while Rh2OAc4 and noncoordinating benzyl group lead the reaction to occur at the C_(3)-position of the indoles.This regioselective C−H functionalization strategy is of significant importance for the discovery of indole drugs. 展开更多
关键词 RHODIUM-CATALYZED Site-selective CROSS-COUPLINGS Carbene insertion Pyridotriazoles
原文传递
Personalizing withdrawal time by insertion time to achieve target adenoma detection rate in colonoscopy
4
作者 Bing-Xin Xu Cong-Zhou Xu +3 位作者 Hao-Yan Zhang Xu-Jin Chen Bing-Ni Wei Cheng Yang 《World Journal of Gastroenterology》 2025年第38期105-119,共15页
BACKGROUND Adenoma detection rate(ADR),a key colonoscopy quality metric,varies with patient demographics and procedural factors.AIM To identify independent predictors of≥25%ADR,develop a risk model,and propose withdr... BACKGROUND Adenoma detection rate(ADR),a key colonoscopy quality metric,varies with patient demographics and procedural factors.AIM To identify independent predictors of≥25%ADR,develop a risk model,and propose withdrawal durations based on different insertion times.METHODS We retrospectively analyzed 830 cases using logistic regression and identified four key factors,validated in a prospective cohort of 5699 patients.Their importance was confirmed using random forest(RF),extreme gradient boosting(XGBoost)and light gradient boosting machine(LightGBM).Attempts to determine targetachieving withdrawal time by grouping cases based on insertion time and Cox regression were inconclusive.Using the 5699-case dataset,we developed a predictive model combining support vector machine(SVM)with XGBoost.We built a Shiny app using this model for clinical application.RESULTS Multivariate logistic regression identified age[odds ratio(OR)=1.05;95%confidence interval(CI):1.03-1.08;P<0.001],male(OR=1.79;95%CI:1.32-2.41;P=0.005),higher endoscopist experience(OR=1.79;95%CI:1.20-2.68;P=0.005),and longer withdrawal time(P<0.001)as independent risk factors for colorectal adenoma.A nomogram demonstrated strong discrimination[area under the curve(AUC)=0.720],with robust calibration and decision-curve performance.Feature importance via RF,XGBoost,and LightGBM confirmed key predictors.A hybrid model combining SVM regression for withdrawal-time estimation and XGBoost classification achieved stable results,with XGBoost reporting AUCs of 0.640 in training and 0.610 in testing,and similar validation outcomes.Deployed via a Shiny app for clinical use.However,model discrimination was modest(AUC:0.61-0.64),suggesting that clinical utility requires further refinement.CONCLUSION A hybrid SVM-XGBoost model using four key endoscopic factors was independently validated and is available as a Shiny app,delivering real-time decision support to streamline endoscopy and enhance clinical outcomes. 展开更多
关键词 COLONOSCOPY Withdrawal time insertion time Adenoma detection rate Machine learning
暂未订购
Concise synthesis of NDP-activated uronic acid by an oxidation reaction insertion strategy
5
作者 Nana Yang Rui Yuan +5 位作者 Xinyue Fu Xiao Tian Jin Yu Shengzhou Ma Liuqing Wen Jiabin Zhang 《Chinese Chemical Letters》 2025年第8期296-302,共7页
Uronic acids are prevalent components of crucial glycoconjugates,pivotal in various biological processes.In nature,NDP-uronic acids,the nucleosides-activated uronic acids,serve as glycosylation donors catalyzed by uro... Uronic acids are prevalent components of crucial glycoconjugates,pivotal in various biological processes.In nature,NDP-uronic acids,the nucleosides-activated uronic acids,serve as glycosylation donors catalyzed by uronosyltransferases(UATs)to construct glycans containing uronic acids.Despite their biological importance,the synthesis of naturally occurring NDP-uronic acids on a large scale remains challenging.Here,we developed an oxidation reaction insertion strategy for the efficient synthesis of NDP-uronic acids,and 11 NDP-uronic acids were successfully prepared in good yield and on a large scale.The prepared NDP-uronic acids can be used to explore new uronosyltransferases and synthesize uronic acids containing carbohydrates for fundamental research. 展开更多
关键词 NDP-uronic acids BIOCATALYSIS Enzyme-mediated biomimetic synthesis Oxidation reaction insertion strategy
原文传递
Construction and validation of a machine learning algorithm-based predictive model for difficult colonoscopy insertion
6
作者 Ren-Xuan Gao Xin-Lei Wang +6 位作者 Ming-Jie Tian Xiao-Ming Li Jia-Jia Zhang Jun-Jing Wang Jing Gao Chao Zhang Zhi-Ting Li 《World Journal of Gastrointestinal Endoscopy》 2025年第7期149-161,共13页
BACKGROUND Difficulty of colonoscopy insertion(DCI)significantly affects colonoscopy effectiveness and serves as a key quality indicator.Predicting and evaluating DCI risk preoperatively is crucial for optimizing intr... BACKGROUND Difficulty of colonoscopy insertion(DCI)significantly affects colonoscopy effectiveness and serves as a key quality indicator.Predicting and evaluating DCI risk preoperatively is crucial for optimizing intraoperative strategies.AIM To evaluate the predictive performance of machine learning(ML)algorithms for DCI by comparing three modeling approaches,identify factors influencing DCI,and develop a preoperative prediction model using ML algorithms to enhance colonoscopy quality and efficiency.METHODS This cross-sectional study enrolled 712 patients who underwent colonoscopy at a tertiary hospital between June 2020 and May 2021.Demographic data,past medical history,medication use,and psychological status were collected.The endoscopist assessed DCI using the visual analogue scale.After univariate screening,predictive models were developed using multivariable logistic regression,least absolute shrinkage and selection operator(LASSO)regression,and random forest(RF)algorithms.Model performance was evaluated based on discrimination,calibration,and decision curve analysis(DCA),and results were visualized using nomograms.RESULTS A total of 712 patients(53.8%male;mean age 54.5 years±12.9 years)were included.Logistic regression analysis identified constipation[odds ratio(OR)=2.254,95%confidence interval(CI):1.289-3.931],abdominal circumference(AC)(77.5–91.9 cm,OR=1.895,95%CI:1.065-3.350;AC≥92 cm,OR=1.271,95%CI:0.730-2.188),and anxiety(OR=1.071,95%CI:1.044-1.100)as predictive factors for DCI,validated by LASSO and RF methods.Model performance revealed training/validation sensitivities of 0.826/0.925,0.924/0.868,and 1.000/0.981;specificities of 0.602/0.511,0.510/0.562,and 0.977/0.526;and corresponding area under the receiver operating characteristic curves(AUCs)of 0.780(0.737-0.823)/0.726(0.654-0.799),0.754(0.710-0.798)/0.723(0.656-0.791),and 1.000(1.000-1.000)/0.754(0.688-0.820),respectively.DCA indicated optimal net benefit within probability thresholds of 0-0.9 and 0.05-0.37.The RF model demonstrated superior diagnostic accuracy,reflected by perfect training sensitivity(1.000)and highest validation AUC(0.754),outperforming other methods in clinical applicability.CONCLUSION The RF-based model exhibited superior predictive accuracy for DCI compared to multivariable logistic and LASSO regression models.This approach supports individualized preoperative optimization,enhancing colonoscopy quality through targeted risk stratification. 展开更多
关键词 COLONOSCOPY Difficulty of colonoscopy insertion Machine learning algorithms Predictive model Logistic regression Least absolute shrinkage and selection operator regression Random forest
暂未订购
高血压患者ACE基因Insertion/Deletion多态性中的罕见突变1例 被引量:1
7
作者 李娅亨 王倩 +1 位作者 杨杉 李亚峰 《中国分子心脏病学杂志》 CAS 2024年第2期6069-6072,共4页
高血压是最强的心血管危险因素之一,目前我国高血压的患病人数已达约2.45亿[1]。《中国心血管健康与疾病报告2021》数据显示,我国≥18岁成人高血压知晓率41.0%,治疗率34.9%,控制率仅11.0%。在高血压的用药治疗方面,由于用药种类繁多,且... 高血压是最强的心血管危险因素之一,目前我国高血压的患病人数已达约2.45亿[1]。《中国心血管健康与疾病报告2021》数据显示,我国≥18岁成人高血压知晓率41.0%,治疗率34.9%,控制率仅11.0%。在高血压的用药治疗方面,由于用药种类繁多,且存在药物反应的个体差异,通常会导致抗高血压药物的疗效不佳或不良反应[2]。2015年,国家卫生和计划生育委员会发布的《药物代谢酶和药物作用靶点基因检测技术指南(试行)》[3]。 展开更多
关键词 高血压 血管紧张素转换酶(ACE)基因 PCR溶解曲线法 insertion/Deletion多态性 一代测序
原文传递
C-F insertion reaction sheds new light on the construction of fluorinated compounds 被引量:1
8
作者 Dong-Sheng Deng Su-Qin Tang +4 位作者 Yong-Tu Yuan Ding-Xiong Xie Zhi-Yuan Zhu Yue-Mei Huang Yun-Lin Liu 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第8期163-169,共7页
The atom-economical C-F insertion chemistry is emerged as a promising technology for the synthesis of various fluorinated scaffolds,which have wide applications both in the academic and the industrial com-munities.The... The atom-economical C-F insertion chemistry is emerged as a promising technology for the synthesis of various fluorinated scaffolds,which have wide applications both in the academic and the industrial com-munities.The past three years have witnessed rapid developments in this field.This highlight provides an overview on the evolution according to the fluorinating agents used. 展开更多
关键词 C-F insertion Benzyl fluoride Acyl fluoride gem-Difluorocyclopropane Fluorinated scaffold
原文传递
A Novel Insertion Solution for the Travelling Salesman Problem
9
作者 Emmanuel Oluwatobi Asani Aderemi Elisha Okeyinka +5 位作者 Sunday Adeola Ajagbe Ayodele Ariyo Adebiyi Roseline Oluwaseun Ogundokun Temitope Samson Adekunle Pragasen Mudali Matthew Olusegun Adigun 《Computers, Materials & Continua》 SCIE EI 2024年第4期1581-1597,共17页
The studypresents theHalfMax InsertionHeuristic (HMIH) as a novel approach to solving theTravelling SalesmanProblem (TSP). The goal is to outperform existing techniques such as the Farthest Insertion Heuristic (FIH) a... The studypresents theHalfMax InsertionHeuristic (HMIH) as a novel approach to solving theTravelling SalesmanProblem (TSP). The goal is to outperform existing techniques such as the Farthest Insertion Heuristic (FIH) andNearest Neighbour Heuristic (NNH). The paper discusses the limitations of current construction tour heuristics,focusing particularly on the significant margin of error in FIH. It then proposes HMIH as an alternative thatminimizes the increase in tour distance and includes more nodes. HMIH improves tour quality by starting withan initial tour consisting of a ‘minimum’ polygon and iteratively adding nodes using our novel Half Max routine.The paper thoroughly examines and compares HMIH with FIH and NNH via rigorous testing on standard TSPbenchmarks. The results indicate that HMIH consistently delivers superior performance, particularly with respectto tour cost and computational efficiency. HMIH’s tours were sometimes 16% shorter than those generated by FIHand NNH, showcasing its potential and value as a novel benchmark for TSP solutions. The study used statisticalmethods, including Friedman’s Non-parametric Test, to validate the performance of HMIH over FIH and NNH.This guarantees that the identified advantages are statistically significant and consistent in various situations. Thiscomprehensive analysis emphasizes the reliability and efficiency of the heuristic, making a compelling case for itsuse in solving TSP issues. The research shows that, in general, HMIH fared better than FIH in all cases studied,except for a few instances (pr439, eil51, and eil101) where FIH either performed equally or slightly better thanHMIH. HMIH’s efficiency is shown by its improvements in error percentage (δ) and goodness values (g) comparedto FIH and NNH. In the att48 instance, HMIH had an error rate of 6.3%, whereas FIH had 14.6% and NNH had20.9%, indicating that HMIH was closer to the optimal solution. HMIH consistently showed superior performanceacross many benchmarks, with lower percentage error and higher goodness values, suggesting a closer match tothe optimal tour costs. This study substantially contributes to combinatorial optimization by enhancing currentinsertion algorithms and presenting a more efficient solution for the Travelling Salesman Problem. It also createsnew possibilities for progress in heuristic design and optimization methodologies. 展开更多
关键词 Nearest neighbour heuristic farthest insertion heuristic half max insertion heuristic tour construction travelling salesman problem
在线阅读 下载PDF
Production of Light Fraction-Based Pyrolytic Fuel from Spirulina platensis Microalgae Using Various Low-Cost Natural Catalysts and Insertion
10
作者 Indra Mamad Gandidi Sukarni Sukarni +4 位作者 Avita Ayu Permanasari Purnami Purnami TuanAmran Tuan Abdullah Anwar Johari Nugroho Agung Pambudi 《Energy Engineering》 EI 2024年第12期3635-3648,共14页
The use of catalysts has significantly enhanced the yield and quality of in-situ pyrolysis products.However,there is a lack of understanding regarding pyrolysis approaches that utilize several low-cost natural catalys... The use of catalysts has significantly enhanced the yield and quality of in-situ pyrolysis products.However,there is a lack of understanding regarding pyrolysis approaches that utilize several low-cost natural catalysts(LCC)and their placement within the reactor.Therefore,this study aims to examine the effects of various LCC on the insitu pyrolysis of spirulina platensis microalgae(SPM)and investigate the impact of different types of catalysts.We employed LCCsuch as zeolite,dolomite,kaolin,and activated carbon,with both layered and uniformlymixed LCCSPM placements.Each experiment was conducted at a constant temperature of 500℃for 60 min.The resulting pyrolytic liquids(bio-oil)and syngas were analyzed using a Gas Chromatography Mass Spectrometry(GC-MS)analyzer to determine the distribution of hydrocarbon compounds.The experimental results indicated that the presence of catalysts significantly influenced the mass yield productivity of liquid fuels and syngas.Activated carbon and zeolite were preferred among the four catalysts for producing liquid fuels(22.4 and 18.6 wt%)when layered and uniformly mixed,respectively.Kaolin with a layered mixture with SPM was more suitable for the production of light fractions(C_(5)–C_(12)),achieving approximately 95.7%peak area,while zeolite with a uniform mixture produced the highest light fraction at about 86.3%peak area.All catalysts except kaolin significantly increased the aromatic compounds in the liquid fuels.Although the amount of oxygenated hydrocarbons in the bio-oil remained relatively high,the final hydrocarbon composition was highly comparable to conventional fuels such as gasoline-88,which has a C_(5)–C_(12)hydrocarbon distribution of approximately 88.1%peak area.Regarding the syngas products,all catalysts except activated carbon successfully converted nitromethane compounds into tetranitromethane hydrocarbons,with activated carbon predominantly yielding nitromethane compounds. 展开更多
关键词 Pyrolysis in-situ SPM LCC BIO-OIL SYNGAS insertion
在线阅读 下载PDF
Enhancing hydrogen evolution and oxidation kinetics through oxygen insertion into nickel lattice
11
作者 Wanli Liang Xiyu Gong +9 位作者 Jinchang Xu Zixuan Dan Fanyan Xie Hulei Yu Hao-Fan Wang Yanshuo Jin Hongjuan Wang Yonghai Cao Hui Meng Hao Yu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期529-539,I0012,共12页
Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution rea... Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction(HER)and hydrogen oxidation reaction(HOR).In this paper,an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance,and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support(denoted as O-Ni/WO_(2)).The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms,simultaneously expanding the lattice and increasing the lattice spacing.Consequently,the adsorption strength of^(*)H and^(*)OH on Ni is optimized,thus resulting in superior electrocatalytic performance of0-Ni/WO_(2)in alkaline HER/HOR.The Tafel slope of O-Ni/WO_(2)@NF for HER is 56 mV dec^(-1),and the kinetic current density of O-Ni/WO_(2)for HOR reaches 4.85 mA cm^(-2),which is ahead of most currently reported catalysts.Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts. 展开更多
关键词 Hydrogen evolution Hydrogen oxidation NICKEL Oxygen insertion Adsorption free energy
在线阅读 下载PDF
Identification and characterization of FpRco1 in regulating vegetative growth and pathogenicity based on T-DNA insertion in Fusarium pseudograminearum
12
作者 Haiyang Li Yuan Zhang +18 位作者 Cancan Qin Zhifang Wang Lingjun Hao Panpan Zhang Yongqiang Yuan Chaopu Ding Mengxuan Wang Feifei Zan Jiaxing Meng Xunyu Zhuang Zheran Liu Limin Wang Haifeng Zhou Linlin Chen Min Wang Xiaoping Xing Hongxia Yuan Honglian Li Shengli Ding 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第9期3055-3065,共11页
Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.... Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease. 展开更多
关键词 Fusarium pseudograminearum T-DNA insertion Rpd3S complex FpRCO1 PATHOGENICITY DON production
在线阅读 下载PDF
An efficient method for constructing a random insertional mutant library for forward genetics in Nannochloropsis oceanica
13
作者 Zhongyi ZHANG Hang LIU +5 位作者 Xiaohui PAN Yanan ZONG Leili FENG Lixian LIU Li GUO Guanpin YANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期216-225,共10页
Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-st... Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species. 展开更多
关键词 Nannochloropsis oceanica genetic transformation random insertional mutant library zeocin pretreatment forward genetics
在线阅读 下载PDF
Velamentous Cord Insertion: Interest of Antenatal Diagnosis and Review of the Literature
14
作者 Karam Harou Aboubacar Sidiki Sidibe +1 位作者 Hicham Abdelkhalki Abderaouf Soummani 《Open Journal of Obstetrics and Gynecology》 2024年第2期234-239,共6页
Velamentous insertion of the umbilical cord corresponds to the insertion of the cord directly on amniotic membranes. It is a rare situation whose frequency varies from 0.5% to 1.69% of single pregnancies. It must be d... Velamentous insertion of the umbilical cord corresponds to the insertion of the cord directly on amniotic membranes. It is a rare situation whose frequency varies from 0.5% to 1.69% of single pregnancies. It must be diagnosed during the morphological ultrasound of the 2nd trimester, actively looking for the association with a vasa previa, due to the risk of fetal haemorrhagic threat. We report an antenatal diagnosis of velamentous cord insertion and its management with literature review. 展开更多
关键词 Velamentous Cord insertion Vasa Previa Antenatal Diagnosis Ultrasound Doppler Benckiser’s Hemorrhage
暂未订购
A metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid bis(pentafluorophenyl)(phenoxy)borane
15
作者 Cheng Wu Yixuan Liu +3 位作者 Chunsheng Xiao Chenyang Hu Xuan Pang Xuesi Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第3期419-422,共4页
A new strategy for the metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid Boron has been first identified.Bis(pentafluorophenyl)(phenoxy)borane was used as a cat... A new strategy for the metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid Boron has been first identified.Bis(pentafluorophenyl)(phenoxy)borane was used as a catalyst for the polymerization reaction system.And polytetrahydrofuran with high molecular weight and narrow molecular weight distribution could be obtained.The proposed mechanism was studied by MALDI-TOF,ESI-MS and O-18 isotope labeling analyses as a metal-free coordination insertion mechanism. 展开更多
关键词 Metal-free catalyst Bis(pentafluorophenyl)(phenoxy)borane Coordination–insertion mechanism Ring-opening polymerization Polytetrahydrofuran
原文传递
Treatment of benign rectal stricture caused by repeated anal insertion by endoscopy and balloon dilation:A case report
16
作者 Shih-Hung Liu Jung-Cheng Kang +3 位作者 Je-Ming Hu Chao-Yang Chen Kuan-Hsun Lin Ta-Wei Pu 《World Journal of Gastrointestinal Endoscopy》 2024年第2期91-97,共7页
BACKGROUND Benign rectal strictures can be categorized as primary(disease-related)and secondary(surgical anastomosis-related).Secondary strictures arise from surgical complications,whereas primary strictures have dive... BACKGROUND Benign rectal strictures can be categorized as primary(disease-related)and secondary(surgical anastomosis-related).Secondary strictures arise from surgical complications,whereas primary strictures have diverse etiologies,including various inflammatory conditions.Benign strictures are usually managed by surgery and endoscopy.We present an unusual etiology of benign rectal stricture caused by the repeated insertion of foreign objects into the rectum for sexual purposes,resulting in rectal injury and subsequent chronic inflammation.CASE SUMMARY A 53-year-old man presented to the outpatient clinic of the Colorectal Surgery Department with symptoms of chronic constipation and bloody stools.The patient previously experienced rectal injury due to foreign object insertion for sexual purposes.Colonoscopy revealed benign circumferential narrowing of the rectum.He underwent treatment by endoscopic argon plasma coagulation and balloon dilation and follow-up as an outpatient for 4 months.A colonoscopy at the end of the follow-up period revealed no evidence of rectal stricture relapse.CONCLUSION A history of rectal injury,followed by chronic inflammation,should be considered in patients with benign rectal strictures.Management with endoscopic argon plasma coagulation and balloon dilation can prevent the need for surgical resection of benign rectal strictures. 展开更多
关键词 Chronic rectal inflammation COLONOSCOPY Benign rectal stricture Foreign body insertion Rectal injury Case report
暂未订购
Efficacy of combined psychological and physical nursing in preventing peripherally inserted central catheter-related thrombosis in gastric cancer patients 被引量:1
17
作者 Wei-Jing Ni Yu-Xiu Xi Yong-Chao Zhou 《World Journal of Gastrointestinal Surgery》 2025年第3期206-212,共7页
BACKGROUND Long-term chemotherapy for patients with gastric cancer(GC),facilitated by peripherally inserted central catheter(PICC)catheterization,reduces vascular damage and enhances drug delivery efficiency but carri... BACKGROUND Long-term chemotherapy for patients with gastric cancer(GC),facilitated by peripherally inserted central catheter(PICC)catheterization,reduces vascular damage and enhances drug delivery efficiency but carries risks of catheter-related complications.A combination of group psychological nursing and physical mo-vement care significantly mitigates the risk of venous thrombosis and improves psychological well-being,and enhances motor function,underscoring its clinical importance.AIM To assess group psychological and physical movement nursing in preventing venous thrombosis in patients with PICC GC.METHODS Sixty-five GC patients with PICC,admitted from January 2022 to January 2023,were randomly divided into two groups using the lottery method:A control group(n=35,routine nursing)and an observation group(n=30,routine nursing plus psychological nursing and physical movement nursing).Both groups re-ceived continuous care for 2 weeks.Pre-nursing and post-nursing data on psycho-logical state,physical function,chemotherapy-related thrombosis incidence,and cancer-related fatigue were analyzed using SPSS 26.0 and GraphPad Prism 8.0.RESULTS After nursing,both groups showed reduced Hamilton Anxiety Scale scores and increased General Perceived Self-Efficacy Scale scores,with the observation group performing better(P<0.05).The Functional Comprehensive Assessment score for the observation group after nursing was(65.42±2.35)points,lower than the control group’s(62.19±4.33)points(P<0.05).Although no significant difference was observed in the incidence of venous thrombosis between the two groups(χ2=0.815,P=0.367),the observation group had lower incidence.Both groups showed decreased Revised Piper Fatigue Scale scores,with the observation group scoring lower(P<0.05).CONCLUSION Group psychological and physical movement nursing for patients with PICC reduces venous thrombosis risk,improves psychological well-being,cancer-related fatigue,and physical function,making it highly promotable. 展开更多
关键词 Group psychological nursing Physical movement nursing Peripherally inserted central catheter Gastric cancer Venous thrombosis Cancer-related fatigue
暂未订购
Efficacy of single-lumen and double-lumen peripherally inserted central catheters in patients undergoing digestive surgery within bundled care contexts
18
作者 Xiao-Hui Ye Rong-Hong Cui +3 位作者 Lei Xu Mei-Jun Wang Ling-Rong Ye Ming Jiang 《World Journal of Gastrointestinal Surgery》 2025年第9期215-226,共12页
BACKGROUND Peripherally inserted central catheters(PICCs)are crucial for patients requiring long-term intravenous therapy,especially within digestive surgery under bundled care protocols.AIM To evaluate and compare th... BACKGROUND Peripherally inserted central catheters(PICCs)are crucial for patients requiring long-term intravenous therapy,especially within digestive surgery under bundled care protocols.AIM To evaluate and compare the efficacy,safety,and patient-reported outcomes of single-lumen vs double-lumen PICCs among patients undergoing digestive surgery within a structured bundled care framework.METHODS This retrospective cohort study analyzed data from 249 patients who underwent digestive surgery and utilized either single-lumen(n=117)or double-lumen(n=132)PICCs between January 2021 and June 2024.Clinical outcomes,patient satisfaction,catheterization duration,and complication rates were compared using statistical analysis via SPSS(version 29.0).The bundled care protocol was consistently applied,focusing on standardized procedures,staff training,and patient support.RESULTS Single-lumen PICCs were associated with a significantly lower thrombosis rate(0.85%)than double-lumen PICCs(6.82%,P=0.039).The single-lumen group experienced shorter catheterization durations(12.5±3.14 days vs 13.6±4.50 days,P=0.025)and higher successful infusion rates(92.7%±5.32%vs 90.4%±6.60%,P=0.003).This group also reported higher comfort scores(8.40±1.20 vs 7.90±1.50,P=0.004)and lower pain levels(2.90±0.70 vs 3.20±0.80,P=0.002).Aside from thrombosis,complication rates showed no significant difference between the groups.CONCLUSION Within bundled care context,single-lumen PICCs demonstrated advantages in reducing thrombosis risk,procedural efficiency,patient comfort,and satisfaction compared with double-lumen PICCs.The findings underscore the importance of considering patient-specific needs and clinical scenarios in catheter choice. 展开更多
关键词 Single-lumen peripherally inserted central catheter Double-lumen peripherally inserted central catheter Digestive surgery Bundled care Patient satisfaction THROMBOSIS
暂未订购
Effect of GaInP and GaAsP inserted into waveguide/barrier interface on carrier leakage in InAlGaAs quantum well 808-nm laser diode
19
作者 FU Meng-jie DONG Hai-liang +3 位作者 JIA Zhi-gang JIA Wei LIANG Jian XU Bing-she 《中国光学(中英文)》 北大核心 2025年第1期186-197,共12页
There is nonradiative recombination in waveguide region owing to severe carrier leakage,which in turn reduces output power and wall-plug efficiency.In this paper,we designed a novel epitaxial structure,which suppresse... There is nonradiative recombination in waveguide region owing to severe carrier leakage,which in turn reduces output power and wall-plug efficiency.In this paper,we designed a novel epitaxial structure,which suppresses carrier leakage by inserting n-Ga_(0.55)In_(0.45)P and p-GaAs_(0.6)P_(0.4) between barriers and waveguide layers,respectively,to modulate the energy band structure and to increase the height of barrier.The results show that the leakage current density reduces by 87.71%,compared to traditional structure.The nonradiative recombination current density of novel structure reduces to 37.411 A/cm^(2),and the output power reaches 12.80 W with wall-plug efficiency of 78.24%at an injection current density 5 A/cm^(2) at room temperature.In addition,the temperature drift coefficient of center wavelength is 0.206 nm/℃at the temperature range from 5℃to 65℃,and the slope of fitted straight line of threshold current with temperature variation is 0.00113.The novel epitaxial structure provides a theoretical basis for achieving high-power laser diode. 展开更多
关键词 808-nm laser diode Ga_(0.55)In_(0.45)P and GaAs_(0.6)P_(0.4)insertion layers InAlGaAs quantum well carrier leakage
在线阅读 下载PDF
Lumbar methicillin-resistant Staphylococcus aureus infection caused by a peripherally inserted central catheter:A case report
20
作者 Xiao-Xiao Yuan Qiong-Qiong Tan +2 位作者 Chen Chen Qing-Qing He Yan-Ning Li 《World Journal of Clinical Cases》 2025年第19期84-91,共8页
BACKGROUND Peripherally inserted central catheters(PICCs)are widely used for administering chemotherapy to breast cancer patients due to their long-term indwelling capability,versatility in drug administration,and fle... BACKGROUND Peripherally inserted central catheters(PICCs)are widely used for administering chemotherapy to breast cancer patients due to their long-term indwelling capability,versatility in drug administration,and flexibility.PICCs infection are a relatively common occurrence,yet there were no reported instances that it can metastasise to the lumbar spine.CASE SUMMARY This case report describes a breast cancer patient who developed a methicillinresistant Staphylococcus aureus lumbar vertebral infection secondary to a PICCrelated infection during chemotherapy.Following PICC removal,bacterial culture confirmed the presence of highly virulent methicillin-resistant Staphylococcus aureus.The patient presented with fever and severe lumbar pain.Lumbar magnetic resonance imaging revealed paraspinal muscle edema from L1 to L3 with abnormal signal intensity in the affected regions,suggestive of vertebral osteomyelitis.Prompt initiation of appropriate antibiotic therapy based on the culture results led to significant improvement in the patient’s lumbar pain.CONCLUSION This case highlights the importance of vigilant infection prevention and control measures to minimize the risk of PICC-related complications,such as bloodstream infections and subsequent metastatic infections. 展开更多
关键词 Peripherally inserted central catheter Methicillin-resistant Staphylococcus aureus infection Lumbar magnetic resonance imaging Breast cancer CHEMOTHERAPY Case report
暂未订购
上一页 1 2 250 下一页 到第
使用帮助 返回顶部