Objective:To compare the efficacy of transoral robotic surgery(TORS)and non-robotic surgery(NRS)in the treatment of tongue base tumors.Methods:A total of 45 patients with tongue base tumors treated in our hospital wer...Objective:To compare the efficacy of transoral robotic surgery(TORS)and non-robotic surgery(NRS)in the treatment of tongue base tumors.Methods:A total of 45 patients with tongue base tumors treated in our hospital were selected,and they were divided into the TORS group and NRS group according to different surgical methods.The surgical indicators and postoperative complications of patients in the two groups were compared and analyzed.Results:Compared with the NRS group,the operative time,bleeding volume and length of hospital stay were less in the TORS group,and the postoperative recurrence rate was less in the TORS group than that in the NRS group.The incidence rate of dysphagia and restricted mouth opening in the TORS group was lower than that in the NRS group within 30 d after surgery,and the difference was statistically significant(P<0.05).Conclusion:TORS has better minimally invasive advantages in the treatment of tongue base tumors,including less intraoperative bleeding,smaller trauma,shorter length of hospital stay and faster recovery.展开更多
By selecting any one limb of 3-RSR parallel robot as a research object, the paper establishes a position and orienta- tion relationship matrix between the moving platform and the base by means of Denavit-Hartenberg (...By selecting any one limb of 3-RSR parallel robot as a research object, the paper establishes a position and orienta- tion relationship matrix between the moving platform and the base by means of Denavit-Hartenberg (D-H) transformation matrix. The error mapping model is derived from original error to the error of the platform by using matrix differential method. This model contains all geometric original errors of the robot. The nonlinear implicit function relation between po- sition and orientation error of the platform and the original geometric errors is simplified as a linear explicit function rela- tion. The results provide a basis for further studying error analysis and error compensation.展开更多
This paper presents a reasonable gridding-parameters extraction method for setting the optimal interpolation nodes in the gridding of scattered observed data. The method can extract optimized gridding parameters based...This paper presents a reasonable gridding-parameters extraction method for setting the optimal interpolation nodes in the gridding of scattered observed data. The method can extract optimized gridding parameters based on the distribution of features in raw data. Modeling analysis proves that distortion caused by gridding can be greatly reduced when using such parameters. We also present some improved technical measures that use human- machine interaction and multi-thread parallel technology to solve inadequacies in traditional gridding software. On the basis of these methods, we have developed software that can be used to grid scattered data using a graphic interface. Finally, a comparison of different gridding parameters on field magnetic data from Ji Lin Province, North China demonstrates the superiority of the proposed method in eliminating the distortions and enhancing gridding efficiency.展开更多
This paper outlines a concurrent engineering environment that supports interaction between members of a geographically dispersed multidisciplinary team who is engaged in engineering design activities. Some ideas of en...This paper outlines a concurrent engineering environment that supports interaction between members of a geographically dispersed multidisciplinary team who is engaged in engineering design activities. Some ideas of engineering design, especially conceptual design are reviewed. A deeper scientific analysis of intelligent design is discussed. A new problem solving strategy and methodologies to implement cooperative design are proposed. Finally, a conceptual model of a blackboard system for accomplishing conceptual design automation is presented. Its fundamental principles, system organization and key implementation techniques are investigated in detail.展开更多
AIM: To determine the effect of ethnicity on the severity of reflux esophagitis (RE) and its complications. METHODS: A retrospective search of the endoscopy database at the University of Florida Health Science Center/...AIM: To determine the effect of ethnicity on the severity of reflux esophagitis (RE) and its complications. METHODS: A retrospective search of the endoscopy database at the University of Florida Health Science Center/Jacksonville for all cases of reflux esophagitis and its complications from January 1 to March 31, 2001 was performed. Inclusion criteria were endoscopic evidence of esophagitis using the LA classif ication, reflux related complications and self-reported ethnicity. The data obtained included esophagitis grade, presence of a hiatal hernia, esophageal ulcer, stricture and Barrett's esophagus, and endoscopy indication. RESULTS: The search identified 259 patients with RE or its complications, of which 171 were non-Hispanic whites and 88 were African Americans. The mean ages and male/female ratios were similar in the two groups. RE grade, esophageal ulcer, stricture and hiatal hernia frequency were likewise similar in the groups. Barrett's esophagus was present more often in non-Hispanic whites than in African Americans (15.8% vs 4.5%; P < 0.01). Heartburn was a more frequent indication for endoscopy in non-Hispanic whites with erosive esophagitis than in African Americans (28.1% vs 7.9%; P < 0.001). CONCLUSION: Distribution of RE grade and frequency of reflux-related esophageal ulcer, stricture andhiatal hernia are similar in non-Hispanic whites and African Americans. Heartburn was more frequently and nausea/vomiting less frequently reported as the primary endoscopic indication in non-Hispanic whites compared with African Americans with erosive esophagitis or its complications. African Americans have a decreased prevalence of Barrett's esophagus compared with non-Hispanic whites.展开更多
The synchronous tracking control problem of a hydraulic parallel manipulator with six degrees of freedom (DOF) is complicated since the inclusion of hydraulic elements increases the order of the system.To solve this p...The synchronous tracking control problem of a hydraulic parallel manipulator with six degrees of freedom (DOF) is complicated since the inclusion of hydraulic elements increases the order of the system.To solve this problem,cascade control method with an inner/outer-loop control structure is used,which masks the hydraulic dynamics with the inner-loop so that the designed controller takes into account of both the mechanical dynamics and the hydraulic dynamics of the manipulator.Furthermore,a cross-coupling control approach is introduced to the synchronous tracking control of the manipulator.The position synchronization error is developed by considering motion synchronization between each actuator joint and its adjacent ones based on the synchronous goal.Then,with the feedback of both position error and synchronization error,the tracking is proven to guarantee that both the position errors and synchronization errors asymptotically converge to zero.Moreover,the effectiveness of the proposed approach is verified by the experimental results performed with a 6-DOF hydraulic parallel manipulator.展开更多
Co-infection with hepatitis C virus and humanimmunodeficiency virus is common in certainpopulations. Among HCV(+) persons, 10 % are alsoHIV (+), and among HIV (+) persons, 25 % are alsoHCV(+). Many studies have shown ...Co-infection with hepatitis C virus and humanimmunodeficiency virus is common in certainpopulations. Among HCV(+) persons, 10 % are alsoHIV (+), and among HIV (+) persons, 25 % are alsoHCV(+). Many studies have shown that in intravenousdrug users, co-infection prevalence can be as high as90-95 %. There is increasing evidence supporting theconcept that people infected with HIV have a muchmore rapid course of their hepatitis C infection.Treatment of co-infection is often challenging becausehighly active anti-retroviral therapy (HAART) therapyis frequently hepatotoxic, especially in the presence ofHCV. The purpose of this review is to describe theeffects that HIV has on hepatitis C, the effects thathepatitis C has on HIV, and the treatment options inthis challenging population.展开更多
Describes a new architecture of a parallel robot with six degrees of freedom and focuses on improving orientation accuracy of movable platform in mechanism, error correction and control methods. A set of formulations ...Describes a new architecture of a parallel robot with six degrees of freedom and focuses on improving orientation accuracy of movable platform in mechanism, error correction and control methods. A set of formulations about inverse kinematics, Jacobin matrix, and forward kinematics for the high precision 6-HTRT parallel robots is presented. The analysis of errors existing in the manipulator is discussed and a novel approach for error correction is advanced. By DSP technique, inverse kinematics is solved in real time conditions with high precision and the hardware control system is given. The experimental results demonstrate the effectiveness of the proposed technique.展开更多
Atrial fibrillation (AF) is an important health problem due to its association with serious complications.Ill Stroke is one of the most serious complications and is the leading cause of death and disabilities in thi...Atrial fibrillation (AF) is an important health problem due to its association with serious complications.Ill Stroke is one of the most serious complications and is the leading cause of death and disabilities in this population. AF in- creases the risk of embolic stroke five times compared to general population. The prevalence of AF varies from 0.5%-15% depending on studied populations such as age,展开更多
Kinematics and dynamics analyses were performed for a spatial 3-revolute joint-revolute joint-clylindric pair(3-RRC) parallel manipulator.This 3-RRC parallel manipulator is composed of a moving platform,a base platfor...Kinematics and dynamics analyses were performed for a spatial 3-revolute joint-revolute joint-clylindric pair(3-RRC) parallel manipulator.This 3-RRC parallel manipulator is composed of a moving platform,a base platform,and three revolute joint-revolute joint-column pair chains which connect the moving platform and the base platform.Firstly,kinematics analysis for 3-RRC parallel manipulator was conducted.Next,on the basis of Lagrange formula,a simply-structured dynamic model of 3-RRC parallel manipulator was derived.Finally,through a calculation example,the variation of motorial parameters of this 3-RRC parallel manipulator,equivalent moment of inertia,driving force/torque and energy consumption was discussed.The research findings have important significance for research and engineering projects such as analyzing dynamic features,mechanism optimization design and control of 3-RRC parallel manipulator.展开更多
Background A considerable proportion of elderly patients with symptomatic severe heart valve disease are treated conservatively de- spite clear indications for surgical intervention. However, little is known about how...Background A considerable proportion of elderly patients with symptomatic severe heart valve disease are treated conservatively de- spite clear indications for surgical intervention. However, little is known about how advanced age and comorbidities affect treatment deci-sion-making and therapeutic outcomes. Methods Patients (n = 234, mean age: 78.5 ± 3.7 years) with symptomatic severe heart valve dis- ease hospitalized in our center were included. One hundred and fifty-one patients (65%) were treated surgically (surgical group) and 83 (35%) were treated conservatively (conservative group). Factors that affected therapeutic decision-making and treatment outcomes were investi- gated and long-term survival was explored. Results Isolated aortic valve disease, female sex, chronic renal insufficiency, aged _〉 80 years, pneumonia, and emergent status were independent factors associated with therapeutic decision-making. In-hospital mortality for the surgical group was 5.3% (8/151). Three patients (3.6%) in the conservative group died during initial hospitalization. Low cardiac output syndrome and chronic renal insufficiency were identified as predictors of in-hospital mortality in the surgical group. Conservative treatment was identi- fied as the single risk factor for late death in the entire study population. The surgical group had better 5-year (77.2% vs. 45.4%, P 〈 0.0001) and 10-year (34.5% vs. 8.9%, P 〈 0.0001) survival rates than the conservative group, even when adjusted by propensity score-matched analysis. Conclusions Advanced age and geriatric comorbidities profoundly affect treatment decision-making for severe heart valve disease. Valve surgery in the elderly was not only safe but was also associated with good long-term survival while conservative treatment was unfavorable for patients with symptomatic severe valve disease.展开更多
The dynamic modeling and solution of the 3-RRS spatial parallel manipulators with flexible links were investigated. Firstly, a new model of spatial flexible beam element was proposed, and the dynamic equations of elem...The dynamic modeling and solution of the 3-RRS spatial parallel manipulators with flexible links were investigated. Firstly, a new model of spatial flexible beam element was proposed, and the dynamic equations of elements and branches of the parallel manipulator were derived. Secondly, according to the kinematic coupling relationship between the moving platform and flexible links, the kinematic constraints of the flexible parallel manipulator were proposed. Thirdly, using the kinematic constraint equations and dynamic model of the moving platform, the overall system dynamic equations of the parallel manipulator were obtained by assembling the dynamic equations of branches. FtLrthermore, a few commonly used effective solutions of second-order differential equation system with variable coefficients were discussed. Newmark numerical method was used to solve the dynamic equations of the flexible parallel manipulator. Finally, the dynamic responses of the moving platform and driving torques of the 3-RRS parallel mechanism with flexible links were analyzed through numerical simulation. The results provide important information for analysis of dynamic performance, dynamics optimization design, dynamic simulation and control of the 3-RRS flexible parallel manipulator.展开更多
Hemoptysis,especially the massivehemoptysis caused by bronchiectasis is acommon,but emergent and critical diseases inclinic.Injection of Herba Houttuyniae extractinto Kongzui(LU 6)was performed to treathemoptysis acco...Hemoptysis,especially the massivehemoptysis caused by bronchiectasis is acommon,but emergent and critical diseases inclinic.Injection of Herba Houttuyniae extractinto Kongzui(LU 6)was performed to treathemoptysis according to the theory oftraditional Chinese medicine and the展开更多
A novel high-speed parallel kinematic machine (PKM) named Delta-S parallel manipulator is proposed, which consists of a fixed base connected to a moving platform through three limbs with identical topology. Each lim...A novel high-speed parallel kinematic machine (PKM) named Delta-S parallel manipulator is proposed, which consists of a fixed base connected to a moving platform through three limbs with identical topology. Each limb is composed of one driving ann and one follower arm, herein, the latter includes two strings and one middle rod, all located in a same plane. Compared with similar manipulators with uniform parameters, the novel and unique topology as well as the addition of two strings of Delta-S manipulator can remove the clearance of the spherical joints, reduce the inertial load of components further, improve the positioning accuracy and dynamic performance, and so on. In order to formulate the kineto-static model of Delta-S manipulator, the kineto-static analyses and models of the driving arm, the generalized follower and the moving platform can be carried out by the D'ALEMBERT principle. For the sake of obtaining the force analytic results of strings, the deformation compatibility condition of strings and the middle rod are determined. Furthermore, in virtue of the assumption of small deformation and the linear superposition principle, the minimal pre-tightening force of the strings is calculated. The main results include that the loads of the strings and the middle rod must be larger than "zero" and the pre-tightening force over the workspace must be larger than the minimal pre-tightening force at any time within the workspace, which lay the foundation for the dynamic analysis and the prototype manufacture of the Delta-S manipulator.展开更多
The aim of this study is to investigate the effect of electro-acupuncture treatment in acute phase of cerebral infarction on the motor functions. In this randomly controlled trial, 86 patients were allocated to two gr...The aim of this study is to investigate the effect of electro-acupuncture treatment in acute phase of cerebral infarction on the motor functions. In this randomly controlled trial, 86 patients were allocated to two groups, the experimental group given clinical and electro-acupuncture treatments for a period of 4 weeks, and the control group given clinical treatment plus active and/or passive functional exercise. The result showed that the level of impairment and disability in both groups were improvement according to the Chinese Stroke Scale, Brunnstrom-Fugl-Meyer score, and Barthel Index throughout the study and 3 months after. The motor functions and the activities of daily living (ADL) were improved significantly in the electro-acupuncture group as compared with the control group (P展开更多
Background Aortic valve stenosis (AS) is very common in the elderly patients above 80 years. Transcatheter aortic valve replacement (TAVR) in such patients is being increasingly performed. This study sought to ass...Background Aortic valve stenosis (AS) is very common in the elderly patients above 80 years. Transcatheter aortic valve replacement (TAVR) in such patients is being increasingly performed. This study sought to assess in-hospital outcome differences between octogenarians and nonagenarians and predictors of mortality in nonagenarians undergoing TAVR with severe AS. Method The study population was derived from the National Inpatient Sample (MS) for the years 2012-2014 using ICD-9 CM procedure codes 35.05 and 35.06 for TAVR. Hospitalizations below 80 years of age were excluded. After performing propensity score matching (1: 2), in-hospital outcomes were compared in matched cohorts. Then, multivariate model was developed to analyze predictors of in-hospital mortality in nonagenarians. Results There were 11,630 hospitalizations in the octogenarian and 5815 hospitalizations in the nonagenarian group. Primary outcome of in-hospital mortality (6% vs. 4.1%, P ≤ 0.001) was higher in nonagenarians compared to octogenarians. Secondary outcomes including stroke (3.4% vs. 2.8%, P ≤ 0.001), renal failure (18.9% vs. 17.3%, P ≤0.001), blood transfusion (35% vs. 32.6%, P ≤ 0.001), vascular complications (4.5% vs. 3.5%, P ≤ 0.001), and pacemaker implantation (27.8% vs. 24.8%, P ≤ 0.001) were higher in nonagenarians. There was no difference in their length of stay. Median cost (70,3745 vs. 65,3815, P ≤ 0.001) was slightly higher with nonagenarian. Conclusions Although in-hospital mortality is slightly higher in nonagenarians, it is acceptable. This difference in mortality is at least partly explained by higher complications in nonagenarians. Efforts should be made to decrease the complications which can further narrow the difference in in-hospital mortality between the groups.展开更多
Aortic valve stenosis (AS) is common in the elderly. Although surgical replacement of the valve has been the gold standard of management, many patients have been excluded from surgery because they were very old, fra...Aortic valve stenosis (AS) is common in the elderly. Although surgical replacement of the valve has been the gold standard of management, many patients have been excluded from surgery because they were very old, frail, or had co-morbidities that increased operative risks. In the last decade, transcatheter aortic valve implantation (TAVI) has emerged as a new treatment option suitable for these patients. This article reviews the available literature on the role of TAVI in elderly patients with severe aortic stenosis. Published studies showed that elderly individuals who underwent TAVI experienced better in-hospital recovery, and similar short and mid-term mortality compared to those underwent surgical treatment of AS. However, long-term outcomes of TAVI in elderly patients are still unknown. The available data in the literature on the ef-fect of advanced age on clinical outcomes of TAVI are limited, but the data that are available suggest that TAVI is a beneficial and tolerable procedure in very old patients. Some of the expected complications after TAVI are reported more in the oldest patients such as vascular in-jures. Other complications were comparable in TAVI patients regardless of their age group. However, very old patients may need closer monitoring to avoid further morbidities and mortality.展开更多
AIM: To compare the results and complications of early pre-cutting technique with standard technique. METHODS: From January 2003 to December 2004, a total of 426 consecutive therapeutic biliary ERCP procedures were ...AIM: To compare the results and complications of early pre-cutting technique with standard technique. METHODS: From January 2003 to December 2004, a total of 426 consecutive therapeutic biliary ERCP procedures were performed by one endoscopist (T.A.). Data were retrospectively collected according to procedure indication and results. Of these, 293 procedures (70.4%) were done with standard technique (group A) and 223 procedures (29.6%) with early pre-cutting technique in case of difficult cannulation (group B). The results and complications of ERCP were compared. RESULTS: Success rate of first attempt cannulation was 98.0% in group A and 87.8% in group 13. The overall incidence of post-ERCP pancreatitis, hemorrhage, perforation and cholangitis was 0%, 0.2%, 0.5% and 0.5%, respectively. Morbidity rate was not significantly different. No procedure-related mortality was occurred. CONCLUSION: For an experienced hand, the early pre-cutting technique for biliary cannulation is safe and effective as standard technique.展开更多
Genual osteoarthritis is a commonly-encountered affection in the middle-aged and oldpersons.The author has treated 65 cases of genualosteoarthritis with massotherapy in the past threeyears,with satisfactory therapeuti...Genual osteoarthritis is a commonly-encountered affection in the middle-aged and oldpersons.The author has treated 65 cases of genualosteoarthritis with massotherapy in the past threeyears,with satisfactory therapeutic results reported asfollows.展开更多
Peripherally inserted central catheter(PICC)is extensively used in critical care settings,because it plays a vital role in providing safe central venous entry.However,PICC is associated with several complications,whic...Peripherally inserted central catheter(PICC)is extensively used in critical care settings,because it plays a vital role in providing safe central venous entry.However,PICC is associated with several complications,which should be detected to shorten the duration of patients'improvement,reduce health care cost,and lessen the incidence of various PICC-related complications.Therefore,this study aimed to outline current literature on PICC procedures,potential complications,and measures for prevention.Understanding evidence-based guidelines regarding insertion technique,early detection of complications,and care bundle of PICC is significant in complication prevention.Implementation of education,training,and appropriate multidisciplinary approaches on PICC care among nurses and caregivers is the key to preventing complications.Thus,the strict care of indwelling PICC lines,the targeted and reasonable PICCassociated complication prevention,and nursing care have a major clinical significance in reducing the occurrence of potential PICC complications.展开更多
文摘Objective:To compare the efficacy of transoral robotic surgery(TORS)and non-robotic surgery(NRS)in the treatment of tongue base tumors.Methods:A total of 45 patients with tongue base tumors treated in our hospital were selected,and they were divided into the TORS group and NRS group according to different surgical methods.The surgical indicators and postoperative complications of patients in the two groups were compared and analyzed.Results:Compared with the NRS group,the operative time,bleeding volume and length of hospital stay were less in the TORS group,and the postoperative recurrence rate was less in the TORS group than that in the NRS group.The incidence rate of dysphagia and restricted mouth opening in the TORS group was lower than that in the NRS group within 30 d after surgery,and the difference was statistically significant(P<0.05).Conclusion:TORS has better minimally invasive advantages in the treatment of tongue base tumors,including less intraoperative bleeding,smaller trauma,shorter length of hospital stay and faster recovery.
基金National Natural Science Foundation of China(No.51275486)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20111420110005)
文摘By selecting any one limb of 3-RSR parallel robot as a research object, the paper establishes a position and orienta- tion relationship matrix between the moving platform and the base by means of Denavit-Hartenberg (D-H) transformation matrix. The error mapping model is derived from original error to the error of the platform by using matrix differential method. This model contains all geometric original errors of the robot. The nonlinear implicit function relation between po- sition and orientation error of the platform and the original geometric errors is simplified as a linear explicit function rela- tion. The results provide a basis for further studying error analysis and error compensation.
基金partly supported by the Public Geological Survey Project(No.201011039)the National High Technology Research and Development Project of China(No.2007AA06Z134)the 111 Project under the Ministry of Education and the State Administration of Foreign Experts Affairs,China(No.B07011)
文摘This paper presents a reasonable gridding-parameters extraction method for setting the optimal interpolation nodes in the gridding of scattered observed data. The method can extract optimized gridding parameters based on the distribution of features in raw data. Modeling analysis proves that distortion caused by gridding can be greatly reduced when using such parameters. We also present some improved technical measures that use human- machine interaction and multi-thread parallel technology to solve inadequacies in traditional gridding software. On the basis of these methods, we have developed software that can be used to grid scattered data using a graphic interface. Finally, a comparison of different gridding parameters on field magnetic data from Ji Lin Province, North China demonstrates the superiority of the proposed method in eliminating the distortions and enhancing gridding efficiency.
文摘This paper outlines a concurrent engineering environment that supports interaction between members of a geographically dispersed multidisciplinary team who is engaged in engineering design activities. Some ideas of engineering design, especially conceptual design are reviewed. A deeper scientific analysis of intelligent design is discussed. A new problem solving strategy and methodologies to implement cooperative design are proposed. Finally, a conceptual model of a blackboard system for accomplishing conceptual design automation is presented. Its fundamental principles, system organization and key implementation techniques are investigated in detail.
文摘AIM: To determine the effect of ethnicity on the severity of reflux esophagitis (RE) and its complications. METHODS: A retrospective search of the endoscopy database at the University of Florida Health Science Center/Jacksonville for all cases of reflux esophagitis and its complications from January 1 to March 31, 2001 was performed. Inclusion criteria were endoscopic evidence of esophagitis using the LA classif ication, reflux related complications and self-reported ethnicity. The data obtained included esophagitis grade, presence of a hiatal hernia, esophageal ulcer, stricture and Barrett's esophagus, and endoscopy indication. RESULTS: The search identified 259 patients with RE or its complications, of which 171 were non-Hispanic whites and 88 were African Americans. The mean ages and male/female ratios were similar in the two groups. RE grade, esophageal ulcer, stricture and hiatal hernia frequency were likewise similar in the groups. Barrett's esophagus was present more often in non-Hispanic whites than in African Americans (15.8% vs 4.5%; P < 0.01). Heartburn was a more frequent indication for endoscopy in non-Hispanic whites with erosive esophagitis than in African Americans (28.1% vs 7.9%; P < 0.001). CONCLUSION: Distribution of RE grade and frequency of reflux-related esophageal ulcer, stricture andhiatal hernia are similar in non-Hispanic whites and African Americans. Heartburn was more frequently and nausea/vomiting less frequently reported as the primary endoscopic indication in non-Hispanic whites compared with African Americans with erosive esophagitis or its complications. African Americans have a decreased prevalence of Barrett's esophagus compared with non-Hispanic whites.
基金Project(50375139) supported by the National Natural Science Foundation of ChinaProject(NCET-04-0545) supported by the New Century Excellent Talent Plan of the Ministry of Education of China
文摘The synchronous tracking control problem of a hydraulic parallel manipulator with six degrees of freedom (DOF) is complicated since the inclusion of hydraulic elements increases the order of the system.To solve this problem,cascade control method with an inner/outer-loop control structure is used,which masks the hydraulic dynamics with the inner-loop so that the designed controller takes into account of both the mechanical dynamics and the hydraulic dynamics of the manipulator.Furthermore,a cross-coupling control approach is introduced to the synchronous tracking control of the manipulator.The position synchronization error is developed by considering motion synchronization between each actuator joint and its adjacent ones based on the synchronous goal.Then,with the feedback of both position error and synchronization error,the tracking is proven to guarantee that both the position errors and synchronization errors asymptotically converge to zero.Moreover,the effectiveness of the proposed approach is verified by the experimental results performed with a 6-DOF hydraulic parallel manipulator.
文摘Co-infection with hepatitis C virus and humanimmunodeficiency virus is common in certainpopulations. Among HCV(+) persons, 10 % are alsoHIV (+), and among HIV (+) persons, 25 % are alsoHCV(+). Many studies have shown that in intravenousdrug users, co-infection prevalence can be as high as90-95 %. There is increasing evidence supporting theconcept that people infected with HIV have a muchmore rapid course of their hepatitis C infection.Treatment of co-infection is often challenging becausehighly active anti-retroviral therapy (HAART) therapyis frequently hepatotoxic, especially in the presence ofHCV. The purpose of this review is to describe theeffects that HIV has on hepatitis C, the effects thathepatitis C has on HIV, and the treatment options inthis challenging population.
文摘Describes a new architecture of a parallel robot with six degrees of freedom and focuses on improving orientation accuracy of movable platform in mechanism, error correction and control methods. A set of formulations about inverse kinematics, Jacobin matrix, and forward kinematics for the high precision 6-HTRT parallel robots is presented. The analysis of errors existing in the manipulator is discussed and a novel approach for error correction is advanced. By DSP technique, inverse kinematics is solved in real time conditions with high precision and the hardware control system is given. The experimental results demonstrate the effectiveness of the proposed technique.
文摘Atrial fibrillation (AF) is an important health problem due to its association with serious complications.Ill Stroke is one of the most serious complications and is the leading cause of death and disabilities in this population. AF in- creases the risk of embolic stroke five times compared to general population. The prevalence of AF varies from 0.5%-15% depending on studied populations such as age,
基金Project(2014QNB18) supported by the Fundamental Research Funds for the Central Universities of ChinaProject(2014CBO46300) supported by the National Basic Research Program of China
文摘Kinematics and dynamics analyses were performed for a spatial 3-revolute joint-revolute joint-clylindric pair(3-RRC) parallel manipulator.This 3-RRC parallel manipulator is composed of a moving platform,a base platform,and three revolute joint-revolute joint-column pair chains which connect the moving platform and the base platform.Firstly,kinematics analysis for 3-RRC parallel manipulator was conducted.Next,on the basis of Lagrange formula,a simply-structured dynamic model of 3-RRC parallel manipulator was derived.Finally,through a calculation example,the variation of motorial parameters of this 3-RRC parallel manipulator,equivalent moment of inertia,driving force/torque and energy consumption was discussed.The research findings have important significance for research and engineering projects such as analyzing dynamic features,mechanism optimization design and control of 3-RRC parallel manipulator.
文摘Background A considerable proportion of elderly patients with symptomatic severe heart valve disease are treated conservatively de- spite clear indications for surgical intervention. However, little is known about how advanced age and comorbidities affect treatment deci-sion-making and therapeutic outcomes. Methods Patients (n = 234, mean age: 78.5 ± 3.7 years) with symptomatic severe heart valve dis- ease hospitalized in our center were included. One hundred and fifty-one patients (65%) were treated surgically (surgical group) and 83 (35%) were treated conservatively (conservative group). Factors that affected therapeutic decision-making and treatment outcomes were investi- gated and long-term survival was explored. Results Isolated aortic valve disease, female sex, chronic renal insufficiency, aged _〉 80 years, pneumonia, and emergent status were independent factors associated with therapeutic decision-making. In-hospital mortality for the surgical group was 5.3% (8/151). Three patients (3.6%) in the conservative group died during initial hospitalization. Low cardiac output syndrome and chronic renal insufficiency were identified as predictors of in-hospital mortality in the surgical group. Conservative treatment was identi- fied as the single risk factor for late death in the entire study population. The surgical group had better 5-year (77.2% vs. 45.4%, P 〈 0.0001) and 10-year (34.5% vs. 8.9%, P 〈 0.0001) survival rates than the conservative group, even when adjusted by propensity score-matched analysis. Conclusions Advanced age and geriatric comorbidities profoundly affect treatment decision-making for severe heart valve disease. Valve surgery in the elderly was not only safe but was also associated with good long-term survival while conservative treatment was unfavorable for patients with symptomatic severe valve disease.
基金Projects(50875002, 60705036) supported by the National Natural Science Foundation of ChinaProject(3062004) supported by Beijing Natural Science Foundation, China+1 种基金Project(20070104) supported by the Key Laboratory of Complex Systems and Intelligence Science, Institute of Automation, Chinese Academy of SciencesProject(2009AA04Z415) supported by the National High-Tech Research and Development Program of China
文摘The dynamic modeling and solution of the 3-RRS spatial parallel manipulators with flexible links were investigated. Firstly, a new model of spatial flexible beam element was proposed, and the dynamic equations of elements and branches of the parallel manipulator were derived. Secondly, according to the kinematic coupling relationship between the moving platform and flexible links, the kinematic constraints of the flexible parallel manipulator were proposed. Thirdly, using the kinematic constraint equations and dynamic model of the moving platform, the overall system dynamic equations of the parallel manipulator were obtained by assembling the dynamic equations of branches. FtLrthermore, a few commonly used effective solutions of second-order differential equation system with variable coefficients were discussed. Newmark numerical method was used to solve the dynamic equations of the flexible parallel manipulator. Finally, the dynamic responses of the moving platform and driving torques of the 3-RRS parallel mechanism with flexible links were analyzed through numerical simulation. The results provide important information for analysis of dynamic performance, dynamics optimization design, dynamic simulation and control of the 3-RRS flexible parallel manipulator.
文摘Hemoptysis,especially the massivehemoptysis caused by bronchiectasis is acommon,but emergent and critical diseases inclinic.Injection of Herba Houttuyniae extractinto Kongzui(LU 6)was performed to treathemoptysis according to the theory oftraditional Chinese medicine and the
基金Projects(50175295,50675151) supported by the National Natural Science Foundation of ChinaProject(11JCZDJC22700) supported by Tianjin Science and Technology Program,ChinaProject(2007AA042001) supported by the National High Technology Research and Development Program of China
文摘A novel high-speed parallel kinematic machine (PKM) named Delta-S parallel manipulator is proposed, which consists of a fixed base connected to a moving platform through three limbs with identical topology. Each limb is composed of one driving ann and one follower arm, herein, the latter includes two strings and one middle rod, all located in a same plane. Compared with similar manipulators with uniform parameters, the novel and unique topology as well as the addition of two strings of Delta-S manipulator can remove the clearance of the spherical joints, reduce the inertial load of components further, improve the positioning accuracy and dynamic performance, and so on. In order to formulate the kineto-static model of Delta-S manipulator, the kineto-static analyses and models of the driving arm, the generalized follower and the moving platform can be carried out by the D'ALEMBERT principle. For the sake of obtaining the force analytic results of strings, the deformation compatibility condition of strings and the middle rod are determined. Furthermore, in virtue of the assumption of small deformation and the linear superposition principle, the minimal pre-tightening force of the strings is calculated. The main results include that the loads of the strings and the middle rod must be larger than "zero" and the pre-tightening force over the workspace must be larger than the minimal pre-tightening force at any time within the workspace, which lay the foundation for the dynamic analysis and the prototype manufacture of the Delta-S manipulator.
文摘The aim of this study is to investigate the effect of electro-acupuncture treatment in acute phase of cerebral infarction on the motor functions. In this randomly controlled trial, 86 patients were allocated to two groups, the experimental group given clinical and electro-acupuncture treatments for a period of 4 weeks, and the control group given clinical treatment plus active and/or passive functional exercise. The result showed that the level of impairment and disability in both groups were improvement according to the Chinese Stroke Scale, Brunnstrom-Fugl-Meyer score, and Barthel Index throughout the study and 3 months after. The motor functions and the activities of daily living (ADL) were improved significantly in the electro-acupuncture group as compared with the control group (P
文摘Background Aortic valve stenosis (AS) is very common in the elderly patients above 80 years. Transcatheter aortic valve replacement (TAVR) in such patients is being increasingly performed. This study sought to assess in-hospital outcome differences between octogenarians and nonagenarians and predictors of mortality in nonagenarians undergoing TAVR with severe AS. Method The study population was derived from the National Inpatient Sample (MS) for the years 2012-2014 using ICD-9 CM procedure codes 35.05 and 35.06 for TAVR. Hospitalizations below 80 years of age were excluded. After performing propensity score matching (1: 2), in-hospital outcomes were compared in matched cohorts. Then, multivariate model was developed to analyze predictors of in-hospital mortality in nonagenarians. Results There were 11,630 hospitalizations in the octogenarian and 5815 hospitalizations in the nonagenarian group. Primary outcome of in-hospital mortality (6% vs. 4.1%, P ≤ 0.001) was higher in nonagenarians compared to octogenarians. Secondary outcomes including stroke (3.4% vs. 2.8%, P ≤ 0.001), renal failure (18.9% vs. 17.3%, P ≤0.001), blood transfusion (35% vs. 32.6%, P ≤ 0.001), vascular complications (4.5% vs. 3.5%, P ≤ 0.001), and pacemaker implantation (27.8% vs. 24.8%, P ≤ 0.001) were higher in nonagenarians. There was no difference in their length of stay. Median cost (70,3745 vs. 65,3815, P ≤ 0.001) was slightly higher with nonagenarian. Conclusions Although in-hospital mortality is slightly higher in nonagenarians, it is acceptable. This difference in mortality is at least partly explained by higher complications in nonagenarians. Efforts should be made to decrease the complications which can further narrow the difference in in-hospital mortality between the groups.
文摘Aortic valve stenosis (AS) is common in the elderly. Although surgical replacement of the valve has been the gold standard of management, many patients have been excluded from surgery because they were very old, frail, or had co-morbidities that increased operative risks. In the last decade, transcatheter aortic valve implantation (TAVI) has emerged as a new treatment option suitable for these patients. This article reviews the available literature on the role of TAVI in elderly patients with severe aortic stenosis. Published studies showed that elderly individuals who underwent TAVI experienced better in-hospital recovery, and similar short and mid-term mortality compared to those underwent surgical treatment of AS. However, long-term outcomes of TAVI in elderly patients are still unknown. The available data in the literature on the ef-fect of advanced age on clinical outcomes of TAVI are limited, but the data that are available suggest that TAVI is a beneficial and tolerable procedure in very old patients. Some of the expected complications after TAVI are reported more in the oldest patients such as vascular in-jures. Other complications were comparable in TAVI patients regardless of their age group. However, very old patients may need closer monitoring to avoid further morbidities and mortality.
文摘AIM: To compare the results and complications of early pre-cutting technique with standard technique. METHODS: From January 2003 to December 2004, a total of 426 consecutive therapeutic biliary ERCP procedures were performed by one endoscopist (T.A.). Data were retrospectively collected according to procedure indication and results. Of these, 293 procedures (70.4%) were done with standard technique (group A) and 223 procedures (29.6%) with early pre-cutting technique in case of difficult cannulation (group B). The results and complications of ERCP were compared. RESULTS: Success rate of first attempt cannulation was 98.0% in group A and 87.8% in group 13. The overall incidence of post-ERCP pancreatitis, hemorrhage, perforation and cholangitis was 0%, 0.2%, 0.5% and 0.5%, respectively. Morbidity rate was not significantly different. No procedure-related mortality was occurred. CONCLUSION: For an experienced hand, the early pre-cutting technique for biliary cannulation is safe and effective as standard technique.
文摘Genual osteoarthritis is a commonly-encountered affection in the middle-aged and oldpersons.The author has treated 65 cases of genualosteoarthritis with massotherapy in the past threeyears,with satisfactory therapeutic results reported asfollows.
文摘Peripherally inserted central catheter(PICC)is extensively used in critical care settings,because it plays a vital role in providing safe central venous entry.However,PICC is associated with several complications,which should be detected to shorten the duration of patients'improvement,reduce health care cost,and lessen the incidence of various PICC-related complications.Therefore,this study aimed to outline current literature on PICC procedures,potential complications,and measures for prevention.Understanding evidence-based guidelines regarding insertion technique,early detection of complications,and care bundle of PICC is significant in complication prevention.Implementation of education,training,and appropriate multidisciplinary approaches on PICC care among nurses and caregivers is the key to preventing complications.Thus,the strict care of indwelling PICC lines,the targeted and reasonable PICCassociated complication prevention,and nursing care have a major clinical significance in reducing the occurrence of potential PICC complications.