In this paper, the instantaneous undeformed chip thickness is modeled to include the dynamic modulation caused by the tool vibration while the dynamic regenerative effects are taken into account. The numerical method ...In this paper, the instantaneous undeformed chip thickness is modeled to include the dynamic modulation caused by the tool vibration while the dynamic regenerative effects are taken into account. The numerical method is used to solve the differential equations goveming the dynamics of the milling system. Several chatter detection criteria are applied synthetically to the simulated signals and the stability diagram is obtained in time-domain. The simulation results in time-domain show a good agreement with the analytical prediction, which is validated by the cutting experiments. By simulating the chatter stability lobes in the time-domain and analyzing the influences of different spindle speeds on the vibration amplitudes of the tool under a Fixed chip-load condition, conclusions could be drawn as follows： In rough milling, higher machining efficiency can be achieved by selecting a spindle speed corresponding to the axial depth of cut in accordance with the simulated chatter stability lobes, and in Fmish milling, lower surface roughness can be achieved by selecting a spindle speed well beyond the resonant frequency of machining system.展开更多
In 1988, Rudolf Pichlmayr pioneered split liver transplantation(SLT), enabling the transplantation of one donor liver into two recipients-one pediatric and one adult patient. In the same year, Henri Bismuth and collea...In 1988, Rudolf Pichlmayr pioneered split liver transplantation(SLT), enabling the transplantation of one donor liver into two recipients-one pediatric and one adult patient. In the same year, Henri Bismuth and colleagues performed the first full right/full left split procedure with two adult recipients. Both splitting techniques were rapidly adopted within the transplant community. However, a SLT is technically demanding, may cause increased perioperative complications, and may potentially transform an excellent deceased donor organ into two marginal quality grafts. Thus, crucial evaluation of donor organs suitable for splitting and careful screening of potential SLT recipients is warranted. Furthermore, the logistic background of the splitting procedure as well as the organ allocation policy must be adapted to further increase the number and the safety of SLT. Under defined circumstances, in selected patients and at experienced transplant centers, SLT outcomes can be similar to those obtained in full organ LT. Thus, SLT is an important tool to reduce the donor organ shortage and waitlist mortality, especially for pediatric patients and small adults. The present review gives an overview of technical aspects, current developments, and clinical outcomes of SLT.展开更多
Background It is difficult and challenging to reconstruct hepatic venous outflow in adult right lobe living donor liver transplantation （LDLT） without the middle hepatic vein （MHV）. Excessive perfusion of the port...Background It is difficult and challenging to reconstruct hepatic venous outflow in adult right lobe living donor liver transplantation （LDLT） without the middle hepatic vein （MHV）. Excessive perfusion of the portal vein and venous outflow obstruction will lead to acute congestion of the graft, ultimately resulting in primary nonfunction. Although various reconstruction patterns have been explored in many countries, there is currently no clear consensus. In this study we describe a technique to prevent ＂chocking＂ of the graft at the outflow anastomosis with the inferior vena cava （IVC） in LDLT using right lobe graft without the MHV. Methods A retrospective analysis was conducted on clinical data from 55 recipients undergoing LDLT using right lobe grafts without the MHV or reconstruction of hepatic venous outflow. The donor＇s right hepatic vein （RHV） was anastomosed with a triangular opening of the recipient IVC; the inferior right hepatic vein （IRHV）, if large enough, was anastomosed directly to the IVC. The great saphenous vein （GSV） was used for reconstruction of significant MHV tributaries. Results No deaths occurred in any of the donors. Of the 55 recipients, complications occurred in 6, including hepatic vein stricture （1 case）, small-for-size syndrome （1）, hepatic artery thrombosis （1）, intestinal bleeding （1）, bile leakage （1）, left subphrenic abscess and pulmonary infection （1）. A total of three patients died, one from small-for-size syndrome and two from multiple system organ failure. Conclusions The multiple-opening vertical anastomosis was reconstructed with hepatic vein outflow. This technique alleviates surgical risk of living donors, ensures excellent venous drainage, and prevents vascular thromboses and primary nonfunction.展开更多
AIM： TO investigate the safety of adult-to-adult living donor liver transplantation （A-A LDLT） in both donors and recipients. METHODS： From January 2002 to July 2006, 50 cases of A-A LDLT were performed at West Ch...AIM： TO investigate the safety of adult-to-adult living donor liver transplantation （A-A LDLT） in both donors and recipients. METHODS： From January 2002 to July 2006, 50 cases of A-A LDLT were performed at West China Hospital, Sichuan University, consisting of 47 cases using right lobe graft without middle hepatic vein （HHV）, and 3 cases using dual grafts （one case using two left lobe, 2 using one right lobe and one left lobe）. The most common diagnoses were hepatitis B liver cirrosis, 30 （60%） cases; and hepatocellular carcinoma, 15 （30%） cases in adult recipients. Among them, 10 cases had the model of end-stage liver disease （HELD） with a score of more than 25. Donor screening consisted of reconstruction of the hepatic blood vessels and biliary system with 3-dimension computed tomography and volumetry of whole liver and right liver volume. Various improved surgical techniques were adopted in the procedures for both donors and recipients. RESULTS： Forty-nine right lobes and 3 left lobes （2 left lobe grafts for 1 recipient, 1 left lobe graft for 1 recipient who had received right lobe graft donated by relative living donor） were obtained from 52 living donors. The 49 right lobe grafts, without HHV, weighed 400 g-850 g （media 550 g）, and the ratio of graft volume to recipient standard liver volume （GV/SLV） ranged from 31.74% to 71.68% （mean 45.35%）. All donors＇ remnant liver volume was over 35% of the whole liver volume. There was no donor mortality. With a follow- up of 2-52 mo （media 9 too）, among 50 adult recipients, complications occurred in 13 （26%） cases and 4 （8%） died postoperatively within 3 mo. Their 1-year actual survival rate was 92%.CONCLUSION： When preoperative CT volumetry shows volume of remnant liver is more than 350, the ratio of right lobe graft to recipients standard liver volume exceeding 40%, A-A LDLT using right lobe graft without MHV should be a very safe procedure for both donors and recipients, otherwise dual grafts liver trans展开更多
This paper presents a method of general geometrical definitions of screw machine rotors and their manufacturing tools.It describes the details of lobe shape specification,and focuses on a new lobe profile,which yields...This paper presents a method of general geometrical definitions of screw machine rotors and their manufacturing tools.It describes the details of lobe shape specification,and focuses on a new lobe profile,which yields a larger cross-sectional area and shorter sealing lines resulting in higher delivery rates for the same tip speed.A well proven mathematical model was used to determine the optimum profile,compressor housing size,and compressor ports to achieve the superior compressors.展开更多
AIM:To evaluate the short-and long-term outcomes of liver resection for caudate lobe hepatocellular carcinoma (HCC).METHODS:We retrospectively analyzed 114 consecutive patients with HCC,originating from the caudate lo...AIM:To evaluate the short-and long-term outcomes of liver resection for caudate lobe hepatocellular carcinoma (HCC).METHODS:We retrospectively analyzed 114 consecutive patients with HCC,originating from the caudate lobe,who underwent resection between January 2001 and January 2007.Univariate and multivariate analyses were performed on several clinicopathologic variables to determine the factors affecting long-term outcome and intrahepatic recurrence.RESULTS:Overall mortality and morbidity were 0% and 18%,respectively.After a median follow-up of 31 mo (interquartile range,11-66 mo),tumor recurrence had occurred in 76 patients (66.7%).The 1-,3-,and 5-year disease-free survival rates were 65.7%,38.1%,and 18.4%,respectively.The 1-,3-,and 5-year overall survival rates were 76.1%,54.7%,and 31.8%,respectively.Univariate analysis showed that subsegmental location of the tumor (45.7% vs 16.2%,P=0.01),liver cirrhosis (12.3% vs 47.9%,P=0.03),surgical margin (18.5% vs 54.6%,P=0.04),vascular invasion (37.9% vs 23.2%,P=0.04) and extended caudate resection (42.1% vs 15.4%,P=0.04) were related to poorer long-term survival.Multivariate analysis showed that only subsegmental location of the tumor,liver cirrhosis and surgical margin were significant independent prognostic factors.CONCLUSION:Hepatectomy was an effective treatment for HCC in the caudate lobe.The subsegmental location of the tumor,liver cirrhosis and surgical margin affected long-term survival.展开更多
Objective： To study the effect and indications ofintracranial pressure （ICP） monitoring for frontal lobe contusion patients. Methods： During January 2005-December 2008, 34 cases of frontal lobe contusion received ...Objective： To study the effect and indications ofintracranial pressure （ICP） monitoring for frontal lobe contusion patients. Methods： During January 2005-December 2008, 34 cases of frontal lobe contusion received ICP monitoring in our department （monitoring group）. Different treatment protocols were adopted according to the results of ICP. Mean-while 46 cases of same type of head-injured patients who did not undergo ICP monitoring served as control group. Results： We found that ICP elevated dramatically within 24 hours after head injury if the contusions were located in frontal longitudinal dehiscence, bilateral undersurface of frontal lobe or dispersed in bilateral lobe. After half a year follow-up and on the basis of Glasgow Coma Scale assessment, the monitoring group showed better outcome than the control group with good recovery in 24 cases （70.6%）, moderate disability in 7 cases （20.6%）, severe disability in 2 （5.88%） and death in 1 （2.94%）. The outcome of control group displayed good condition in 25 cases （54.3%）, moderate disabilities in 8 （17.4%）, severe disability in 7 （15.2%）, and death in 6 （13.0%）. Conclusions： Frontal lobe contusions are vulnerable and complex head injuries, especially when the contusions are located in frontal longitudinal dehiscence, bilateral undersurface of frontal lobe or diffused in bilateral lobes. These patients should undergo ICP monitoring regardless of their consciousness status. IflCP elevates over 25 mm Hg, the craniotomy is mandatory and will markedly reduce the mortality and disability of these patients.展开更多
AIM:To investigate the significance of the surgical approaches in the prognosis of hepatocellular carcinoma(HCC) located in the caudate lobe with a multivariate regression analysis using a Cox proportional hazard mode...AIM:To investigate the significance of the surgical approaches in the prognosis of hepatocellular carcinoma(HCC) located in the caudate lobe with a multivariate regression analysis using a Cox proportional hazard model.METHODS:Thirty-six patients with HCC underwent caudate lobectomy at a single tertiary referral center between January 1995 and June 2010.In this series,left-sided,right-sided and bilateral approaches were used.The outcomes of patients who underwent isolated caudate lobectomy or caudate lobectomy combined with an additional partial hepatectomy were compared.The survival curves of the isolated and combined resection groups were generated by the Kaplan-Meier method and compared by a log-rank test.RESULTS:Sixteen(44.4%) of 36 patients underwent isolated total or partial caudate lobectomy whereas 20(55.6%) received a total or partial caudate lobectomy combined with an additional partial hepatectomy.The median diameter of the tumor was 6.7 cm(range,2.1-15.8 cm).Patients who underwent an isolated caudate lobectomy had significantly longer operative time(240 min vs 170 min),longer length of hospital stay(18 d vs 13 d) and more blood loss(780 mL vs 270 mL) than patients who underwent a combined caudate lobectomy(P < 0.05).There were no perioperative deaths in both groups of patients.The complication rate was higher in the patients who underwent an isolated caudate lobectomy than in those who underwent combined caudate lobectomy(31.3% vs 10.0%,P < 0.05).The 1-,3-and 5-year disease-free survival rates for the isolated caudate lobectomy and the combined caudate lobectomy groups were 54.5%,6.5% and 0% and 85.8%,37.6% and 0%,respectively(P < 0.05).The corresponding overall survival rates were 73.8%,18.5% and 0% and 93.1%,43.6% and 6.7%(P < 0.05).CONCLUSION:The caudate lobectomy combined with an additional partial hepatectomy is preferred because this approach is technically less demanding and offers an adequate surgical margin.展开更多
BACKGROUND:Caudate lobectomy has long been considered technically difficult.This study aimed to elaborate the significance of early control of short hepatic portal veins(SHPVs) in isolated hepatic caudate lobectomy or...BACKGROUND:Caudate lobectomy has long been considered technically difficult.This study aimed to elaborate the significance of early control of short hepatic portal veins(SHPVs) in isolated hepatic caudate lobectomy or in hepatic caudate lobectomy combined with major partial hepatectomy,and to describe the anatomical characteristics of SHPVs.METHODS:The data of 117 patients who underwent either isolated or combined caudate lobectomy by the same team of surgeons from 2005 to 2009 were retrospectively analyzed.From 2005 to 2007(group A,n=55),we carried out early control of short hepatic veins(SHVs) only;from 2008 to 2009(group B,n=62),we carried out early control of both SHVs and SHPVs.The two groups were compared to evaluate which surgical procedure was better.A detailed anatomical study was then carried out on the last 25 consecutive patients in group B to study the number and distribution of SHPVs during surgery.RESULTS:Patients in group B had less intra-operative blood loss,less impairment of liver function,shorter postoperative hospital stay,fewer postoperative complications and required less blood transfusion(P<0.05).The number of SHPVs in the 25 patients was 183,with 7.3±2.7 per patient.The diameters of SHPVs were 1 to 4 mm.On average,3.4 SHPVs/patient came from the left portal vein,2.2 from the bifurcation,1.4 from the right portal vein,and 0.3 from the main portal vein.On average,3.3 SHPVs/patient supplied segment I of the liver,0.4 for segment II,2.1 for segment IV,1.4 for segment V and 0.1 for segment VI.CONCLUSION:Early control of SHPVs in isolated or combined hepatic caudate lobectomy may be a useful method to decrease surgical risk and improve postoperative recovery.展开更多
BACKGROUND: Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. To overcome the problem of graft size insufficiency, living donor liver transplantation (LDLT) using the...BACKGROUND: Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. To overcome the problem of graft size insufficiency, living donor liver transplantation (LDLT) using the right lobe has become a standard method for adult patients. As the drainage of the median sector (segments V, VIII and IV) is mainly by the middle hepatic vein (MHV), the issue of whether the MHV should or should not be taken with the graft or whether the MHV tributaries (V5, V8) should be reconstructed in the recipient remains to be settled. DATA SOURCES: An English-language literature search was conducted using MEDLINE (1985-2006) on right lobe living donor liver transplantation, middle hepatic vein, vein graft, hepatic venoplasty and other related subjects. RESULTS: Some institutions had proposed their policy for the management of the MHV and its tributaries. Dominancy of the hepatic vein, graft-to-recipient weight ratio, and remnant liver volume as well as the donor-to-recipient body weight ratio, the volume of the donor's right lobe to the recipient's standard liver volume and the size of MHV tributaries are the major elements for the criteria of inclusion of the MHV, while for the policy of MHV tributaries reconstruction, the proportion of congestive area and the diameter of the tributaries are the critical elements. Optimal vein grafts such as recipient's portal vein and hepatic venoplasty technique have been used to obviate hepatic congestion and venous drainage disturbance. CONCLUSIONS: Taking right liver grafts with the MHV trunk (extended right lobe grafts) or performing the MHV tributaries reconstruction in modified right lobe grafts, according to the criteria proposed by the institutions with rich experience, can solve the congestion problem of the right paramedian sector and help to improve the outcomes of the patients. The additional use of optimal vein grafts and hepatic venoplasty also can guarantee excellent venous drainage.展开更多
AIM: To determine whether the combination of platelet count(PLT) with spleen volume parameters and right liver volume(RV) measured by magnetic resonance imaging(MRI) could predict the Child-Pugh class of liver cirrhos...AIM: To determine whether the combination of platelet count(PLT) with spleen volume parameters and right liver volume(RV) measured by magnetic resonance imaging(MRI) could predict the Child-Pugh class of liver cirrhosis and esophageal varices(EV).METHODS: Two hundred and five cirrhotic patients with hepatitis B and 40 healthy volunteers underwent abdominal triphasic-enhancement MRI and laboratory examination of PLT in 109/L. Cirrhotic patients underwent endoscopy for detecting EV. Spleen maximal width(W), thickness(T) and length(L) in mm together with spleen volume(SV) and RV in mm3 were measured by MRI, and spleen volume index(SI) in mm3 was obtained by W × T × L. SV/PLT, SI/PLT and RV × PLT/SV(RVPS) were calculated and statistically analyzed to assess cirrhosis and EV.RESULTS: SV/PLT(r = 0.676) and SI/PLT(r = 0.707) increased, and PLT(r =-0.626) and RVPS(r =-0.802) decreased with the progress of Child-Pugh class(P < 0.001 for all). All parameters could determine the presence of cirrhosis, distinguish between each class of Child-Pugh class, and identify the presence of EV [the areas under the curve(AUCs) = 0.661-0.973]. A m o n g p a ra m e t e r s, R V P S c o u l d b e s t d e t e r m i n e presence and each class of cirrhosis with AUCs of 0.973 and 0.740-0.853, respectively; and SV/PLT could best identify EV with an AUC of 0.782.CONCLUSION: The combination of PLT with SV and RV could predict Child-Pugh class of liver cirrhosis and identify the presence of esophageal varices.展开更多
Milling of the thin-walled workpiece in the aerospace industry is a critical process due to the high flexibility of the workpiece. In this paper, a flexible fixture based on the magnetorheological (MR) fluids is desig...Milling of the thin-walled workpiece in the aerospace industry is a critical process due to the high flexibility of the workpiece. In this paper, a flexible fixture based on the magnetorheological (MR) fluids is designed to investigate the regenerative chatter suppression during the machining. Based on the analysis of typical structural components in the aerospace industry, a general complex thin-walled workpiece with fixture and damping constraint can be equivalent as a rectangular cantilever beam. On the basis of the equivalent models, natural frequency and mode shape function of the thin-walled workpiece is obtained according to the Euler-Bernoulli beam assumptions. Then, the displacement response function of the bending vibration of the beam is represented by the product of all the mode shape function and the generalized coordinate. Furthermore, a dynamic equation of the workpiece-fixture system considering the external damping factor is proposed using the Lagrangian method in terms of all the mode shape function and the generalized coordinate, and the response of system under the dynamic cutting force is calculated to evaluate the stability of the milling process under damping control. Finally, the feasibility and effectiveness of the proposed approach are validated by the impact hammer experiments and several machining tests. (C) 2016 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.展开更多
Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocamp...Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampal formation （HF） in patients with medial temporal lobe epilepsy （MTLE）. Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity （MD） and fractional anisotropy （FA） from the symmetrical-voxel sampling regions of the anterior HF were calculated in all subjects. The MD and FA values were compared across the groups. Results No significant differences of MD and FA values were noted between right and left HF in the controls. In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [（9.27±1.09）×10^-4 mm^2/s], compared with the values in the contralateral HF [（8.20±0.59）×10^-4 min^2]s] （t = 4.479, P = 0.001） and healthy subjects [（7.58±0.51）×10^-4 mm^2/s] （P 〈 0.001）, but no significant differences were found in FA. When compared with the controls, patients had a significantly higher MD in the contralateral HF （P 〈 0.05）, but the difference in FA was not statistically significant. Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpful for preoperative evaluation of such patients.展开更多
Temporal lobe epilepsy is the most common form of focal epilepsy in adults,accounting for one third of all diagnosed epileptic patients,with seizures originating from or involving mesial temporal structures such as th...Temporal lobe epilepsy is the most common form of focal epilepsy in adults,accounting for one third of all diagnosed epileptic patients,with seizures originating from or involving mesial temporal structures such as the hippocampus,and many of these patients being refractory to treatment with anti-epileptic drugs.Temporal lobe epilepsy is the most common childhood neurological disorder and,compared with adults,the symptoms are greatly affected by age and brain development.Diagnosis of temporal lobe epilepsy relies on clinical examination,patient history,electroencephalographic recordings,and brain imaging.Misdiagnosis or delay in diagnosis is common.A molecular biomarker that could distinguish epilepsy from healthy subjects and other neurological conditions would allow for an earlier and more accurate diagnosis and appropriate treatment to be initiated.Among possible biomarkers of pathological changes as well as potential therapeutic targets in the epileptic brain are micro RNAs.Most of the recent studies had performed micro RNA profiling in body fluids such as blood plasma and blood serum and brain tissues such as temporal cortex tissue and hippocampal tissue.A large number of micro RNAs were dysregulated when compared to healthy controls and with some overlap between individual studies that could serve as potential biomarkers.For example,in adults with temporal lobe epilepsy,possible biomarkers are miR-199a-3p in blood plasma and miR-142-5p in blood plasma and blood serum.In adults with mesial temporal lobe epilepsy,possible biomarkers are miR-153 in blood plasma and miR-145-3p in blood serum.However,in many of the studies involving patients who receive one or several anti-epileptic drugs,the influence of these on micro RNA expression in body fluids and brain tissues is largely unknown.Further studies are warranted with children with temporal lobe epilepsy and consideration should be given to utilizing mouse or rat and non-human primate models of temporal lobe epilepsy.The animal models could be used to confirm 展开更多
基金National Key Technologies R&D Program (2006BA103A16)Fundamental Research Project of COSTIND (K1203020507, B2120061326)
文摘In this paper, the instantaneous undeformed chip thickness is modeled to include the dynamic modulation caused by the tool vibration while the dynamic regenerative effects are taken into account. The numerical method is used to solve the differential equations goveming the dynamics of the milling system. Several chatter detection criteria are applied synthetically to the simulated signals and the stability diagram is obtained in time-domain. The simulation results in time-domain show a good agreement with the analytical prediction, which is validated by the cutting experiments. By simulating the chatter stability lobes in the time-domain and analyzing the influences of different spindle speeds on the vibration amplitudes of the tool under a Fixed chip-load condition, conclusions could be drawn as follows： In rough milling, higher machining efficiency can be achieved by selecting a spindle speed corresponding to the axial depth of cut in accordance with the simulated chatter stability lobes, and in Fmish milling, lower surface roughness can be achieved by selecting a spindle speed well beyond the resonant frequency of machining system.
文摘In 1988, Rudolf Pichlmayr pioneered split liver transplantation(SLT), enabling the transplantation of one donor liver into two recipients-one pediatric and one adult patient. In the same year, Henri Bismuth and colleagues performed the first full right/full left split procedure with two adult recipients. Both splitting techniques were rapidly adopted within the transplant community. However, a SLT is technically demanding, may cause increased perioperative complications, and may potentially transform an excellent deceased donor organ into two marginal quality grafts. Thus, crucial evaluation of donor organs suitable for splitting and careful screening of potential SLT recipients is warranted. Furthermore, the logistic background of the splitting procedure as well as the organ allocation policy must be adapted to further increase the number and the safety of SLT. Under defined circumstances, in selected patients and at experienced transplant centers, SLT outcomes can be similar to those obtained in full organ LT. Thus, SLT is an important tool to reduce the donor organ shortage and waitlist mortality, especially for pediatric patients and small adults. The present review gives an overview of technical aspects, current developments, and clinical outcomes of SLT.
文摘Background It is difficult and challenging to reconstruct hepatic venous outflow in adult right lobe living donor liver transplantation （LDLT） without the middle hepatic vein （MHV）. Excessive perfusion of the portal vein and venous outflow obstruction will lead to acute congestion of the graft, ultimately resulting in primary nonfunction. Although various reconstruction patterns have been explored in many countries, there is currently no clear consensus. In this study we describe a technique to prevent ＂chocking＂ of the graft at the outflow anastomosis with the inferior vena cava （IVC） in LDLT using right lobe graft without the MHV. Methods A retrospective analysis was conducted on clinical data from 55 recipients undergoing LDLT using right lobe grafts without the MHV or reconstruction of hepatic venous outflow. The donor＇s right hepatic vein （RHV） was anastomosed with a triangular opening of the recipient IVC; the inferior right hepatic vein （IRHV）, if large enough, was anastomosed directly to the IVC. The great saphenous vein （GSV） was used for reconstruction of significant MHV tributaries. Results No deaths occurred in any of the donors. Of the 55 recipients, complications occurred in 6, including hepatic vein stricture （1 case）, small-for-size syndrome （1）, hepatic artery thrombosis （1）, intestinal bleeding （1）, bile leakage （1）, left subphrenic abscess and pulmonary infection （1）. A total of three patients died, one from small-for-size syndrome and two from multiple system organ failure. Conclusions The multiple-opening vertical anastomosis was reconstructed with hepatic vein outflow. This technique alleviates surgical risk of living donors, ensures excellent venous drainage, and prevents vascular thromboses and primary nonfunction.
文摘AIM： TO investigate the safety of adult-to-adult living donor liver transplantation （A-A LDLT） in both donors and recipients. METHODS： From January 2002 to July 2006, 50 cases of A-A LDLT were performed at West China Hospital, Sichuan University, consisting of 47 cases using right lobe graft without middle hepatic vein （HHV）, and 3 cases using dual grafts （one case using two left lobe, 2 using one right lobe and one left lobe）. The most common diagnoses were hepatitis B liver cirrosis, 30 （60%） cases; and hepatocellular carcinoma, 15 （30%） cases in adult recipients. Among them, 10 cases had the model of end-stage liver disease （HELD） with a score of more than 25. Donor screening consisted of reconstruction of the hepatic blood vessels and biliary system with 3-dimension computed tomography and volumetry of whole liver and right liver volume. Various improved surgical techniques were adopted in the procedures for both donors and recipients. RESULTS： Forty-nine right lobes and 3 left lobes （2 left lobe grafts for 1 recipient, 1 left lobe graft for 1 recipient who had received right lobe graft donated by relative living donor） were obtained from 52 living donors. The 49 right lobe grafts, without HHV, weighed 400 g-850 g （media 550 g）, and the ratio of graft volume to recipient standard liver volume （GV/SLV） ranged from 31.74% to 71.68% （mean 45.35%）. All donors＇ remnant liver volume was over 35% of the whole liver volume. There was no donor mortality. With a follow- up of 2-52 mo （media 9 too）, among 50 adult recipients, complications occurred in 13 （26%） cases and 4 （8%） died postoperatively within 3 mo. Their 1-year actual survival rate was 92%.CONCLUSION： When preoperative CT volumetry shows volume of remnant liver is more than 350, the ratio of right lobe graft to recipients standard liver volume exceeding 40%, A-A LDLT using right lobe graft without MHV should be a very safe procedure for both donors and recipients, otherwise dual grafts liver trans
文摘This paper presents a method of general geometrical definitions of screw machine rotors and their manufacturing tools.It describes the details of lobe shape specification,and focuses on a new lobe profile,which yields a larger cross-sectional area and shorter sealing lines resulting in higher delivery rates for the same tip speed.A well proven mathematical model was used to determine the optimum profile,compressor housing size,and compressor ports to achieve the superior compressors.
文摘AIM:To evaluate the short-and long-term outcomes of liver resection for caudate lobe hepatocellular carcinoma (HCC).METHODS:We retrospectively analyzed 114 consecutive patients with HCC,originating from the caudate lobe,who underwent resection between January 2001 and January 2007.Univariate and multivariate analyses were performed on several clinicopathologic variables to determine the factors affecting long-term outcome and intrahepatic recurrence.RESULTS:Overall mortality and morbidity were 0% and 18%,respectively.After a median follow-up of 31 mo (interquartile range,11-66 mo),tumor recurrence had occurred in 76 patients (66.7%).The 1-,3-,and 5-year disease-free survival rates were 65.7%,38.1%,and 18.4%,respectively.The 1-,3-,and 5-year overall survival rates were 76.1%,54.7%,and 31.8%,respectively.Univariate analysis showed that subsegmental location of the tumor (45.7% vs 16.2%,P=0.01),liver cirrhosis (12.3% vs 47.9%,P=0.03),surgical margin (18.5% vs 54.6%,P=0.04),vascular invasion (37.9% vs 23.2%,P=0.04) and extended caudate resection (42.1% vs 15.4%,P=0.04) were related to poorer long-term survival.Multivariate analysis showed that only subsegmental location of the tumor,liver cirrhosis and surgical margin were significant independent prognostic factors.CONCLUSION:Hepatectomy was an effective treatment for HCC in the caudate lobe.The subsegmental location of the tumor,liver cirrhosis and surgical margin affected long-term survival.
文摘Objective： To study the effect and indications ofintracranial pressure （ICP） monitoring for frontal lobe contusion patients. Methods： During January 2005-December 2008, 34 cases of frontal lobe contusion received ICP monitoring in our department （monitoring group）. Different treatment protocols were adopted according to the results of ICP. Mean-while 46 cases of same type of head-injured patients who did not undergo ICP monitoring served as control group. Results： We found that ICP elevated dramatically within 24 hours after head injury if the contusions were located in frontal longitudinal dehiscence, bilateral undersurface of frontal lobe or dispersed in bilateral lobe. After half a year follow-up and on the basis of Glasgow Coma Scale assessment, the monitoring group showed better outcome than the control group with good recovery in 24 cases （70.6%）, moderate disability in 7 cases （20.6%）, severe disability in 2 （5.88%） and death in 1 （2.94%）. The outcome of control group displayed good condition in 25 cases （54.3%）, moderate disabilities in 8 （17.4%）, severe disability in 7 （15.2%）, and death in 6 （13.0%）. Conclusions： Frontal lobe contusions are vulnerable and complex head injuries, especially when the contusions are located in frontal longitudinal dehiscence, bilateral undersurface of frontal lobe or diffused in bilateral lobes. These patients should undergo ICP monitoring regardless of their consciousness status. IflCP elevates over 25 mm Hg, the craniotomy is mandatory and will markedly reduce the mortality and disability of these patients.
文摘AIM:To investigate the significance of the surgical approaches in the prognosis of hepatocellular carcinoma(HCC) located in the caudate lobe with a multivariate regression analysis using a Cox proportional hazard model.METHODS:Thirty-six patients with HCC underwent caudate lobectomy at a single tertiary referral center between January 1995 and June 2010.In this series,left-sided,right-sided and bilateral approaches were used.The outcomes of patients who underwent isolated caudate lobectomy or caudate lobectomy combined with an additional partial hepatectomy were compared.The survival curves of the isolated and combined resection groups were generated by the Kaplan-Meier method and compared by a log-rank test.RESULTS:Sixteen(44.4%) of 36 patients underwent isolated total or partial caudate lobectomy whereas 20(55.6%) received a total or partial caudate lobectomy combined with an additional partial hepatectomy.The median diameter of the tumor was 6.7 cm(range,2.1-15.8 cm).Patients who underwent an isolated caudate lobectomy had significantly longer operative time(240 min vs 170 min),longer length of hospital stay(18 d vs 13 d) and more blood loss(780 mL vs 270 mL) than patients who underwent a combined caudate lobectomy(P < 0.05).There were no perioperative deaths in both groups of patients.The complication rate was higher in the patients who underwent an isolated caudate lobectomy than in those who underwent combined caudate lobectomy(31.3% vs 10.0%,P < 0.05).The 1-,3-and 5-year disease-free survival rates for the isolated caudate lobectomy and the combined caudate lobectomy groups were 54.5%,6.5% and 0% and 85.8%,37.6% and 0%,respectively(P < 0.05).The corresponding overall survival rates were 73.8%,18.5% and 0% and 93.1%,43.6% and 6.7%(P < 0.05).CONCLUSION:The caudate lobectomy combined with an additional partial hepatectomy is preferred because this approach is technically less demanding and offers an adequate surgical margin.
基金supported by grants from the Research Fund of Shanghai Science and Technology Commission(10495810400)the Youth Research Fund of Shanghai Health Bureau (2009Y065)
文摘BACKGROUND:Caudate lobectomy has long been considered technically difficult.This study aimed to elaborate the significance of early control of short hepatic portal veins(SHPVs) in isolated hepatic caudate lobectomy or in hepatic caudate lobectomy combined with major partial hepatectomy,and to describe the anatomical characteristics of SHPVs.METHODS:The data of 117 patients who underwent either isolated or combined caudate lobectomy by the same team of surgeons from 2005 to 2009 were retrospectively analyzed.From 2005 to 2007(group A,n=55),we carried out early control of short hepatic veins(SHVs) only;from 2008 to 2009(group B,n=62),we carried out early control of both SHVs and SHPVs.The two groups were compared to evaluate which surgical procedure was better.A detailed anatomical study was then carried out on the last 25 consecutive patients in group B to study the number and distribution of SHPVs during surgery.RESULTS:Patients in group B had less intra-operative blood loss,less impairment of liver function,shorter postoperative hospital stay,fewer postoperative complications and required less blood transfusion(P<0.05).The number of SHPVs in the 25 patients was 183,with 7.3±2.7 per patient.The diameters of SHPVs were 1 to 4 mm.On average,3.4 SHPVs/patient came from the left portal vein,2.2 from the bifurcation,1.4 from the right portal vein,and 0.3 from the main portal vein.On average,3.3 SHPVs/patient supplied segment I of the liver,0.4 for segment II,2.1 for segment IV,1.4 for segment V and 0.1 for segment VI.CONCLUSION:Early control of SHPVs in isolated or combined hepatic caudate lobectomy may be a useful method to decrease surgical risk and improve postoperative recovery.
基金This study was supported by a grant from the National Key Basic Research Program (973) of China (No. 2003 CB515501) Important Project from Science and Technology Department of Zhejiang Province (No. 021103699).
文摘BACKGROUND: Left liver graft from a small donor will not meet the metabolic demands of a larger adult recipient. To overcome the problem of graft size insufficiency, living donor liver transplantation (LDLT) using the right lobe has become a standard method for adult patients. As the drainage of the median sector (segments V, VIII and IV) is mainly by the middle hepatic vein (MHV), the issue of whether the MHV should or should not be taken with the graft or whether the MHV tributaries (V5, V8) should be reconstructed in the recipient remains to be settled. DATA SOURCES: An English-language literature search was conducted using MEDLINE (1985-2006) on right lobe living donor liver transplantation, middle hepatic vein, vein graft, hepatic venoplasty and other related subjects. RESULTS: Some institutions had proposed their policy for the management of the MHV and its tributaries. Dominancy of the hepatic vein, graft-to-recipient weight ratio, and remnant liver volume as well as the donor-to-recipient body weight ratio, the volume of the donor's right lobe to the recipient's standard liver volume and the size of MHV tributaries are the major elements for the criteria of inclusion of the MHV, while for the policy of MHV tributaries reconstruction, the proportion of congestive area and the diameter of the tributaries are the critical elements. Optimal vein grafts such as recipient's portal vein and hepatic venoplasty technique have been used to obviate hepatic congestion and venous drainage disturbance. CONCLUSIONS: Taking right liver grafts with the MHV trunk (extended right lobe grafts) or performing the MHV tributaries reconstruction in modified right lobe grafts, according to the criteria proposed by the institutions with rich experience, can solve the congestion problem of the right paramedian sector and help to improve the outcomes of the patients. The additional use of optimal vein grafts and hepatic venoplasty also can guarantee excellent venous drainage.
基金Supported by The National Natural Science Foundation of China,No.81050033the Key Projects of Sichuan Province Science and Technology Pillar Program,No.2011SZ0237+2 种基金the Science Foundation for Distinguished Young Scholars of Sichuan Province in China,No.2010JQ0039the Key Science and Technology Project of Chinese Ministry of Public Health,No.2014114the Natural Science Key Project of North Sichuan Medical College,No.CBY12-A-ZD03
文摘AIM: To determine whether the combination of platelet count(PLT) with spleen volume parameters and right liver volume(RV) measured by magnetic resonance imaging(MRI) could predict the Child-Pugh class of liver cirrhosis and esophageal varices(EV).METHODS: Two hundred and five cirrhotic patients with hepatitis B and 40 healthy volunteers underwent abdominal triphasic-enhancement MRI and laboratory examination of PLT in 109/L. Cirrhotic patients underwent endoscopy for detecting EV. Spleen maximal width(W), thickness(T) and length(L) in mm together with spleen volume(SV) and RV in mm3 were measured by MRI, and spleen volume index(SI) in mm3 was obtained by W × T × L. SV/PLT, SI/PLT and RV × PLT/SV(RVPS) were calculated and statistically analyzed to assess cirrhosis and EV.RESULTS: SV/PLT(r = 0.676) and SI/PLT(r = 0.707) increased, and PLT(r =-0.626) and RVPS(r =-0.802) decreased with the progress of Child-Pugh class(P < 0.001 for all). All parameters could determine the presence of cirrhosis, distinguish between each class of Child-Pugh class, and identify the presence of EV [the areas under the curve(AUCs) = 0.661-0.973]. A m o n g p a ra m e t e r s, R V P S c o u l d b e s t d e t e r m i n e presence and each class of cirrhosis with AUCs of 0.973 and 0.740-0.853, respectively; and SV/PLT could best identify EV with an AUC of 0.782.CONCLUSION: The combination of PLT with SV and RV could predict Child-Pugh class of liver cirrhosis and identify the presence of esophageal varices.
基金supported by the National Basic Research Program of China (Grant No. 2013CB035802)the 111 Project of China (Grant No. B13044)
文摘Milling of the thin-walled workpiece in the aerospace industry is a critical process due to the high flexibility of the workpiece. In this paper, a flexible fixture based on the magnetorheological (MR) fluids is designed to investigate the regenerative chatter suppression during the machining. Based on the analysis of typical structural components in the aerospace industry, a general complex thin-walled workpiece with fixture and damping constraint can be equivalent as a rectangular cantilever beam. On the basis of the equivalent models, natural frequency and mode shape function of the thin-walled workpiece is obtained according to the Euler-Bernoulli beam assumptions. Then, the displacement response function of the bending vibration of the beam is represented by the product of all the mode shape function and the generalized coordinate. Furthermore, a dynamic equation of the workpiece-fixture system considering the external damping factor is proposed using the Lagrangian method in terms of all the mode shape function and the generalized coordinate, and the response of system under the dynamic cutting force is calculated to evaluate the stability of the milling process under damping control. Finally, the feasibility and effectiveness of the proposed approach are validated by the impact hammer experiments and several machining tests. (C) 2016 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.
文摘Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampal formation （HF） in patients with medial temporal lobe epilepsy （MTLE）. Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity （MD） and fractional anisotropy （FA） from the symmetrical-voxel sampling regions of the anterior HF were calculated in all subjects. The MD and FA values were compared across the groups. Results No significant differences of MD and FA values were noted between right and left HF in the controls. In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [（9.27±1.09）×10^-4 mm^2/s], compared with the values in the contralateral HF [（8.20±0.59）×10^-4 min^2]s] （t = 4.479, P = 0.001） and healthy subjects [（7.58±0.51）×10^-4 mm^2/s] （P 〈 0.001）, but no significant differences were found in FA. When compared with the controls, patients had a significantly higher MD in the contralateral HF （P 〈 0.05）, but the difference in FA was not statistically significant. Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpful for preoperative evaluation of such patients.
文摘Temporal lobe epilepsy is the most common form of focal epilepsy in adults,accounting for one third of all diagnosed epileptic patients,with seizures originating from or involving mesial temporal structures such as the hippocampus,and many of these patients being refractory to treatment with anti-epileptic drugs.Temporal lobe epilepsy is the most common childhood neurological disorder and,compared with adults,the symptoms are greatly affected by age and brain development.Diagnosis of temporal lobe epilepsy relies on clinical examination,patient history,electroencephalographic recordings,and brain imaging.Misdiagnosis or delay in diagnosis is common.A molecular biomarker that could distinguish epilepsy from healthy subjects and other neurological conditions would allow for an earlier and more accurate diagnosis and appropriate treatment to be initiated.Among possible biomarkers of pathological changes as well as potential therapeutic targets in the epileptic brain are micro RNAs.Most of the recent studies had performed micro RNA profiling in body fluids such as blood plasma and blood serum and brain tissues such as temporal cortex tissue and hippocampal tissue.A large number of micro RNAs were dysregulated when compared to healthy controls and with some overlap between individual studies that could serve as potential biomarkers.For example,in adults with temporal lobe epilepsy,possible biomarkers are miR-199a-3p in blood plasma and miR-142-5p in blood plasma and blood serum.In adults with mesial temporal lobe epilepsy,possible biomarkers are miR-153 in blood plasma and miR-145-3p in blood serum.However,in many of the studies involving patients who receive one or several anti-epileptic drugs,the influence of these on micro RNA expression in body fluids and brain tissues is largely unknown.Further studies are warranted with children with temporal lobe epilepsy and consideration should be given to utilizing mouse or rat and non-human primate models of temporal lobe epilepsy.The animal models could be used to confirm
