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
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
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
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
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
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
Objective:To explore the evidence-based nursing optimization strategy for catheter tip positioning during peripherally inserted central catheter(PICC)insertion in patients with persistent left superior vena cava(PLSVC...Objective:To explore the evidence-based nursing optimization strategy for catheter tip positioning during peripherally inserted central catheter(PICC)insertion in patients with persistent left superior vena cava(PLSVC).Methods:For one ovarian cancer patient with PICC malposition in the coronary sinus(CS)due to PLSVC,multimodal imaging techniques were integrated to accurately locate the catheter tip.The catheter position was adjusted based on evidence(withdrawing 5 cm),and a standardized nursing process was established,including personalized health education,catheter fixation and displacement monitoring,complication monitoring,establishment of a specialized disease information archive system,and formulation of a follow-up plan.Results:The catheter tip was successfully withdrawn from the coronary sinus(at the T8 level)to the middle and lower part of the PLSVC(at the T6 vertebral level),and the catheter functioned normally after adjustment.No complications such as arrhythmia or thrombosis occurred during the 332-day chemotherapy period.Conclusion:The PICC tip in PLSVC patients should be positioned in the middle and lower part of the PLSVC(at the T5–T7 vertebral level).This new standard can effectively avoid CS-related complications.The integration of multi-modal imaging techniques and evidence-based nursing management are key to ensuring safe infusion.展开更多
[Objective] The aim of this study is to understand the genetic characteristics of a grain shape mutant and its possible role in genetic improvement of grain yield in rice. [Method] On the basis of the collection of T-...[Objective] The aim of this study is to understand the genetic characteristics of a grain shape mutant and its possible role in genetic improvement of grain yield in rice. [Method] On the basis of the collection of T-DNA tag lines, the progeny of homozygous plants carrying T-DNA insertion were screened for mutants with mutated phenotypes. The genetic analysis of the mutant and test for the linkage between the mutated phenotype and the T-DNA insertion were carried out to determine its genetic characteristics. [Result] In the present study, a grain shape mutant induced by T-DNA insertion in rice was identified, which showed small grain. Genetic analysis of the mutant showed that the two types of phenotype, normal and small grain in the segregating populations derived from the T-DNA heterozygotes, fit the ratio of 3∶1. Test for Basta resistance showed that all the mutants were resistant while the normal plants segregated for resistant and susceptible by the ratio of 2∶1. The results indicated that the mutant phenotype cosegregated with Bar gene. The small grain mutant caused by T-DNA insertion was confirmed by PCR amplification aiming at T-DNA. [Conclusion] The grain shape mutant is useful for isolation of the tagged gene and genetic improvement in rice.展开更多
Objective The present study aimed to estimate the association between susceptibility to migraine and the 12nucleotide insertion/deletion （indel） polymorphism in promoter region ofα 2B -adrenergic receptor gene （AD...Objective The present study aimed to estimate the association between susceptibility to migraine and the 12nucleotide insertion/deletion （indel） polymorphism in promoter region ofα 2B -adrenergic receptor gene （ADRA2B）.Methods A case-control study was carried out in Chinese Han population,including 368 cases of migraine and 517 controls.Genomic DNA was extracted from blood samples,and DNA fragments containing the site of polymorphism were amplified by PCR.Data were adjusted for sex,age,migraine history and family history,and analyzed using a logistic regression model.Results There was no association between indel polymorphism and migraine,at either the allele or the genotype level.Conclusion These findings do not support a functional significance of ADRA2B indel polymorphism at position-4825 relative to the start codon in the far upstream region of the promoter in the present migraine subjects.展开更多
An algorithm of path based timing optimization by buffer insertion is presented.The algorithm adopts a high order model to estimate interconnect delay and a nonlinear delay model based on look up table for gate dela...An algorithm of path based timing optimization by buffer insertion is presented.The algorithm adopts a high order model to estimate interconnect delay and a nonlinear delay model based on look up table for gate delay estimation.And heuristic method of buffer insertion is presented to reduce delay.The algorithm is tested by industral circuit case.Experimental results show that the algorithm can optimize the timing of circuit efficiently and the timing constraint is satisfied.展开更多
A fine-grain sleep transistor insertion technique based on our simplified leakage current and delay models is proposed to reduce leakage current. The key idea is to model the leakage current reduction problem as a mix...A fine-grain sleep transistor insertion technique based on our simplified leakage current and delay models is proposed to reduce leakage current. The key idea is to model the leakage current reduction problem as a mixed-integer linear programming （MLP） problem in order to simultaneously place and size the sleep transistors optimally. Because of better circuit slack utilization, our experimental results show that the MLP model can save leakage by 79.75%, 93.56%, and 94.99% when the circuit slowdown is 0%, 3%, and 5%, respectively. The MLP model also achieves on average 74.79% less area penalty compared to the conventional fixed slowdown method when the circuit slowdown is 7%.展开更多
A parallel embedding overlapped iterative (EOI) algorithm about classicimplicit equations with asymmetric Saul'yev schemes (CIS-EOI) to solve one-dimensional diffusionequations is discussed to improve the properti...A parallel embedding overlapped iterative (EOI) algorithm about classicimplicit equations with asymmetric Saul'yev schemes (CIS-EOI) to solve one-dimensional diffusionequations is discussed to improve the properties of the segment classic implicit iterative (SCII)algorithm. The structure of CIS-EOI method is given and the stability of scheme and convergence ofiteration are proved by matrix method. The property of gradual-approach convergence is alsodiscussed. It has been shown that the convergent rate is faster and the property of gradual-approachconvergence also becomes better with the increasing of the net point in subsystems than with theSCII algorithm. The simulation examples show that the parallel iterative algorithm with a differentinsertion scheme CIS-EOI is more effective.展开更多
BACKGROUND Medial dished(MD)liner designs for cruciate-retaining(CR)total knee arthroplasty(TKA)are a relatively novel development.MD tibial inserts have a more constraining medial side,which allows for more similar k...BACKGROUND Medial dished(MD)liner designs for cruciate-retaining(CR)total knee arthroplasty(TKA)are a relatively novel development.MD tibial inserts have a more constraining medial side,which allows for more similar kinematics and function to a native knee.AIM To evaluate the clinical results and patient-reported outcomes after CR TKA procedures utilizing a kinematically designed medial dish system.METHODS A multicenter,retrospective cohort review of 139 primary elective TKAs utilizing a kinematically designed CR Knee System(JOURNEY™II CR MD;Smith and Nephew,Memphis,TN,United States)at three different institutions with a minimum of two years of follow-up.Demographic information,clinical outcomes,and patient-reported outcome measures were collected and analyzed.RESULTS With up to 3.7 years from surgery,overall implant survivorship was 98.6%.There were significant postoperative increases in the average Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores(17.4 at 6 months,26.1 points at two years or more,P<0.001).CONCLUSION The combination of high implant survivorship and substantial improvements in patient-reported outcome measures suggests that the medial dish tibial insert represents a safe and effective option within TKA.Additional investigation is necessary to evaluate the long-term survivorship of this design.展开更多
Computer-navigated pedicle screw insertion is applied to the thoracic and lumbar spine to attain high insertion accuracy and a low rate of screw-related complications.However,some in vivo and in vitro studies have sho...Computer-navigated pedicle screw insertion is applied to the thoracic and lumbar spine to attain high insertion accuracy and a low rate of screw-related complications.However,some in vivo and in vitro studies have shown that no advantages are gained with the use of navigation techniques compared to conventional techniques.Additionally,inconsistent conclusions have been drawn in various studies due to different population characteristics and methods used to assess the accuracy of screw placement.Moreover,it is not clear whether pedicle screw insertion with navigation techniques decreases the incidence of screw-related complications.Therefore,this study was sought to perform a meta-analysis of all available prospective evidence regarding pedicle screw insertion with or without navigation techniques in human thoracic and lumbar spine.We considered in vivo comparative studies that assessed the results of pedicle screw placement with or without navigation techniques.PubMed,Ovid MEDLINE and EMBASE databases were searched.Three published randomized controlled trials（RCTs） and nine retrospective comparative studies met the inclusion criteria.These studies included a total of 732 patients in whom 4,953 screws were inserted.In conclusion,accuracy of the position of grade I,II,III and IV screws and complication rate related to pedicle screw placement were significantly increased when navigation techniques were used in comparison to conventional techniques.Future research in this area should include RCTs with well-planned methodology to limit bias and report on validated,patient-based outcome measures.展开更多
AIM It is well known that colonoscopy can bedifficult due to abdominal pain induced duringcolonoscope insertion,if sedative agents are notgiven.Recently,an extra-flexible,small-diameter colonoscope(CF-SV,Olympus Inc.,...AIM It is well known that colonoscopy can bedifficult due to abdominal pain induced duringcolonoscope insertion,if sedative agents are notgiven.Recently,an extra-flexible,small-diameter colonoscope(CF-SV,Olympus Inc.,Japan)was developed in order to improve safetyand comfort.The aim of this study was toaccess the usefulness of the CF-SV.METHODS One hundred patients undergoingsigmoidoscopy were recruited and colonoscopywas performed by one experiencedcolonoscopist.First,a routine-type colonoscope(CF-2301)was inserted into the colon withoutsedation.When the patient complained ofabdominal pain(even if mild),the scope wasnot advanced further and was withdrawn afterthe anatomic location of its tip was determinedfluoroscopically.Then,the CF-SV was inserteduntil it reached the cecun or the site whereabdominal pain occurred.Previous abdominalsurgery and abdominal disease were consideredas unfavorable factors(UF)and the relationshipbetween abdominal pain and UF,age and genderwere investigated.Furthermore,the colonicinsertion pressures in 36 patients with abdominalpain were measured with a force gauge.RESULTS Thirty-four cases(34%)felt no painwith the CF-2301 and successful pancolon-0scopies to the cecum were performed.Sixty-six cases(66%)complained of abdominal pain.The procedure was painless for 47% of men and24% of women,respectively.The CF-2301 scopefailed to reach the sigmoid-descending colon junctions in 59(89.4%)of the 66 patientscomplaining of abdominal pain.However,CF-SVreached proximal area in 94.9% of those whofailed with CF-2301.The median pressure forpain-inducing was 700 g/cm^2.CONCLUSION Unsedated patients with UFwere prone to complain of pain when thestandard-type CF-2301 scope was used.Thenewly developed extra-flexible CF-SV is usefulfor the aged and for those with UF or being proneto suffer from abdominal pain.Sedative agentsmay be unnecessary if this new type ofcolonoscope is used.展开更多
文摘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.
文摘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.
基金CAMS Innovation Fund for Medical Sciences(CIFMS)(Nos.2022-I2M-1-013,2022-I2M-1-014,2022-I2M-2-002).
文摘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.
基金Supported by the Young and Middle-Aged Talents Program of Wuxi Health Commission,No.BJ2020011Cohort Research Program of Wuxi Medical Center,Nanjing Medical University,No.WMCC202314Wuxi People’s Hospital 2024“Wild Goose Array Talent”Reserve Discipline Leader,No.2024-YZ-HBDTR-YC-2024.
文摘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.
基金the Chinese Clinical Trial Registry(No.ChiCTR2000040109)approved by the Hospital Ethics Committee(No.20210130017).
文摘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.
基金financially supported by National Natural Science Foundation of China(No.22207113 to J.Zhang)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110588to J.Zhang)Natural Science Foundation of Shanghai Municipality(No.22ZR1474000 to L.Wen)。
文摘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.
文摘Objective:To explore the evidence-based nursing optimization strategy for catheter tip positioning during peripherally inserted central catheter(PICC)insertion in patients with persistent left superior vena cava(PLSVC).Methods:For one ovarian cancer patient with PICC malposition in the coronary sinus(CS)due to PLSVC,multimodal imaging techniques were integrated to accurately locate the catheter tip.The catheter position was adjusted based on evidence(withdrawing 5 cm),and a standardized nursing process was established,including personalized health education,catheter fixation and displacement monitoring,complication monitoring,establishment of a specialized disease information archive system,and formulation of a follow-up plan.Results:The catheter tip was successfully withdrawn from the coronary sinus(at the T8 level)to the middle and lower part of the PLSVC(at the T6 vertebral level),and the catheter functioned normally after adjustment.No complications such as arrhythmia or thrombosis occurred during the 332-day chemotherapy period.Conclusion:The PICC tip in PLSVC patients should be positioned in the middle and lower part of the PLSVC(at the T5–T7 vertebral level).This new standard can effectively avoid CS-related complications.The integration of multi-modal imaging techniques and evidence-based nursing management are key to ensuring safe infusion.
文摘[Objective] The aim of this study is to understand the genetic characteristics of a grain shape mutant and its possible role in genetic improvement of grain yield in rice. [Method] On the basis of the collection of T-DNA tag lines, the progeny of homozygous plants carrying T-DNA insertion were screened for mutants with mutated phenotypes. The genetic analysis of the mutant and test for the linkage between the mutated phenotype and the T-DNA insertion were carried out to determine its genetic characteristics. [Result] In the present study, a grain shape mutant induced by T-DNA insertion in rice was identified, which showed small grain. Genetic analysis of the mutant showed that the two types of phenotype, normal and small grain in the segregating populations derived from the T-DNA heterozygotes, fit the ratio of 3∶1. Test for Basta resistance showed that all the mutants were resistant while the normal plants segregated for resistant and susceptible by the ratio of 2∶1. The results indicated that the mutant phenotype cosegregated with Bar gene. The small grain mutant caused by T-DNA insertion was confirmed by PCR amplification aiming at T-DNA. [Conclusion] The grain shape mutant is useful for isolation of the tagged gene and genetic improvement in rice.
基金supported by the National Natural Science Foundation of China(No.30800621)China Postdoctoral Science Foundation(No.20080431121,200902530)
文摘Objective The present study aimed to estimate the association between susceptibility to migraine and the 12nucleotide insertion/deletion （indel） polymorphism in promoter region ofα 2B -adrenergic receptor gene （ADRA2B）.Methods A case-control study was carried out in Chinese Han population,including 368 cases of migraine and 517 controls.Genomic DNA was extracted from blood samples,and DNA fragments containing the site of polymorphism were amplified by PCR.Data were adjusted for sex,age,migraine history and family history,and analyzed using a logistic regression model.Results There was no association between indel polymorphism and migraine,at either the allele or the genotype level.Conclusion These findings do not support a functional significance of ADRA2B indel polymorphism at position-4825 relative to the start codon in the far upstream region of the promoter in the present migraine subjects.
文摘An algorithm of path based timing optimization by buffer insertion is presented.The algorithm adopts a high order model to estimate interconnect delay and a nonlinear delay model based on look up table for gate delay estimation.And heuristic method of buffer insertion is presented to reduce delay.The algorithm is tested by industral circuit case.Experimental results show that the algorithm can optimize the timing of circuit efficiently and the timing constraint is satisfied.
文摘A fine-grain sleep transistor insertion technique based on our simplified leakage current and delay models is proposed to reduce leakage current. The key idea is to model the leakage current reduction problem as a mixed-integer linear programming （MLP） problem in order to simultaneously place and size the sleep transistors optimally. Because of better circuit slack utilization, our experimental results show that the MLP model can save leakage by 79.75%, 93.56%, and 94.99% when the circuit slowdown is 0%, 3%, and 5%, respectively. The MLP model also achieves on average 74.79% less area penalty compared to the conventional fixed slowdown method when the circuit slowdown is 7%.
文摘A parallel embedding overlapped iterative (EOI) algorithm about classicimplicit equations with asymmetric Saul'yev schemes (CIS-EOI) to solve one-dimensional diffusionequations is discussed to improve the properties of the segment classic implicit iterative (SCII)algorithm. The structure of CIS-EOI method is given and the stability of scheme and convergence ofiteration are proved by matrix method. The property of gradual-approach convergence is alsodiscussed. It has been shown that the convergent rate is faster and the property of gradual-approachconvergence also becomes better with the increasing of the net point in subsystems than with theSCII algorithm. The simulation examples show that the parallel iterative algorithm with a differentinsertion scheme CIS-EOI is more effective.
文摘BACKGROUND Medial dished(MD)liner designs for cruciate-retaining(CR)total knee arthroplasty(TKA)are a relatively novel development.MD tibial inserts have a more constraining medial side,which allows for more similar kinematics and function to a native knee.AIM To evaluate the clinical results and patient-reported outcomes after CR TKA procedures utilizing a kinematically designed medial dish system.METHODS A multicenter,retrospective cohort review of 139 primary elective TKAs utilizing a kinematically designed CR Knee System(JOURNEY™II CR MD;Smith and Nephew,Memphis,TN,United States)at three different institutions with a minimum of two years of follow-up.Demographic information,clinical outcomes,and patient-reported outcome measures were collected and analyzed.RESULTS With up to 3.7 years from surgery,overall implant survivorship was 98.6%.There were significant postoperative increases in the average Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores(17.4 at 6 months,26.1 points at two years or more,P<0.001).CONCLUSION The combination of high implant survivorship and substantial improvements in patient-reported outcome measures suggests that the medial dish tibial insert represents a safe and effective option within TKA.Additional investigation is necessary to evaluate the long-term survivorship of this design.
文摘Computer-navigated pedicle screw insertion is applied to the thoracic and lumbar spine to attain high insertion accuracy and a low rate of screw-related complications.However,some in vivo and in vitro studies have shown that no advantages are gained with the use of navigation techniques compared to conventional techniques.Additionally,inconsistent conclusions have been drawn in various studies due to different population characteristics and methods used to assess the accuracy of screw placement.Moreover,it is not clear whether pedicle screw insertion with navigation techniques decreases the incidence of screw-related complications.Therefore,this study was sought to perform a meta-analysis of all available prospective evidence regarding pedicle screw insertion with or without navigation techniques in human thoracic and lumbar spine.We considered in vivo comparative studies that assessed the results of pedicle screw placement with or without navigation techniques.PubMed,Ovid MEDLINE and EMBASE databases were searched.Three published randomized controlled trials（RCTs） and nine retrospective comparative studies met the inclusion criteria.These studies included a total of 732 patients in whom 4,953 screws were inserted.In conclusion,accuracy of the position of grade I,II,III and IV screws and complication rate related to pedicle screw placement were significantly increased when navigation techniques were used in comparison to conventional techniques.Future research in this area should include RCTs with well-planned methodology to limit bias and report on validated,patient-based outcome measures.
基金Sasagawa Medical Scholarship Foundation(from 1999-2000)
文摘AIM It is well known that colonoscopy can bedifficult due to abdominal pain induced duringcolonoscope insertion,if sedative agents are notgiven.Recently,an extra-flexible,small-diameter colonoscope(CF-SV,Olympus Inc.,Japan)was developed in order to improve safetyand comfort.The aim of this study was toaccess the usefulness of the CF-SV.METHODS One hundred patients undergoingsigmoidoscopy were recruited and colonoscopywas performed by one experiencedcolonoscopist.First,a routine-type colonoscope(CF-2301)was inserted into the colon withoutsedation.When the patient complained ofabdominal pain(even if mild),the scope wasnot advanced further and was withdrawn afterthe anatomic location of its tip was determinedfluoroscopically.Then,the CF-SV was inserteduntil it reached the cecun or the site whereabdominal pain occurred.Previous abdominalsurgery and abdominal disease were consideredas unfavorable factors(UF)and the relationshipbetween abdominal pain and UF,age and genderwere investigated.Furthermore,the colonicinsertion pressures in 36 patients with abdominalpain were measured with a force gauge.RESULTS Thirty-four cases(34%)felt no painwith the CF-2301 and successful pancolon-0scopies to the cecum were performed.Sixty-six cases(66%)complained of abdominal pain.The procedure was painless for 47% of men and24% of women,respectively.The CF-2301 scopefailed to reach the sigmoid-descending colon junctions in 59(89.4%)of the 66 patientscomplaining of abdominal pain.However,CF-SVreached proximal area in 94.9% of those whofailed with CF-2301.The median pressure forpain-inducing was 700 g/cm^2.CONCLUSION Unsedated patients with UFwere prone to complain of pain when thestandard-type CF-2301 scope was used.Thenewly developed extra-flexible CF-SV is usefulfor the aged and for those with UF or being proneto suffer from abdominal pain.Sedative agentsmay be unnecessary if this new type ofcolonoscope is used.
