Over the past few years,video live streaming has gained immense popularity as a leading internet application.In current solutions offered by cloud service providers,the Group of Pictures(GOP)length of the video source...Over the past few years,video live streaming has gained immense popularity as a leading internet application.In current solutions offered by cloud service providers,the Group of Pictures(GOP)length of the video source often significantly impacts end-to-end(E2E)latency.However,designing an optimized GOP structure to reduce this effect remains a significant challenge.This paper presents two key contributions.First,it explores how the GOP length at the video source influences E2E latency in mainstream cloud streaming services.Experimental results reveal that the mean E2E latency increases linearly with longer GOP lengths.Second,this paper proposes EGOP(an Enhanced GOP structure)that can be implemented in streaming media servers.Experiments demonstrate that EGOP maintains a consistent E2E latency,unaffected by the GOP length of the video source.Specifically,even with a GOP length of 10 s,the E2E latency remains at 1.35 s,achieving a reduction of 6.98 s compared to Volcano-Engine(the live streaming service provider for TikTok).This makes EGOP a promising solution for low-latency live streaming.展开更多
BACKGROUND Robotic assistance is increasingly used for donor and recipient hepatectomy in liver transplantation,yet existing evidence is fragmented and variably indirect.AIM To evaluate clinical outcomes,surgical perf...BACKGROUND Robotic assistance is increasingly used for donor and recipient hepatectomy in liver transplantation,yet existing evidence is fragmented and variably indirect.AIM To evaluate clinical outcomes,surgical performance,and economic effects of robotic-assisted donor and recipient hepatectomy in the transplant pathway.METHODS Following Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 and a priori registration,systematic reviews were included with or without meta-analysis.Four databases were searched through July 2025.Methodological quality was appraised with a measurement tool to assess systematic reviews(AMSTAR 2),and certainty was graded with grading of recommendations assessment,development and evaluation(GRADE).Evidence overlap was calculated via a citation-matrix-based corrected covered area(CCA).Effect sizes were prespecified as risk ratios(RR)for dichotomous outcomes and mean differences for continuous outcomes.RESULTS Five reviews met the inclusion criteria,four with meta-analyses and one consensus review used only for context.Donor(direct)findings were more favorable for robotics in terms of estimated blood loss(≈-117 mL)and length of stay(≈-0.6 days),although with longer operative time(≈+105 minutes).Absolute risks for donor complications were not estimable from ratio-only data.Recipient(indirect)meta-analysis indicated robotics to be favorable in terms of conversion(RR≈0.41)and severe morbidity(RR≈0.81),with a trend toward lower overall morbidity(RR≈0.92)and no difference in 30-day mortality.Differences in length of stay and operative time were small and heterogeneous.Economic evidence(indirect,network meta-analysis)suggested higher procedural costs for robotic vs laparoscopic intervention,but lower hospitalization costs vs open intervention,with laparoscopy the least expensive overall.AMSTAR 2 ratings were moderate-to-high across the reviews,GRADE certainty was low for key donor continuous outcomes,and low-to-moderate for recipient and economic outcomes.Overlap was slight(graded-corpus CCA=0.0%;including a contextual non-transplant review increased CCA to≈1.25%).CONCLUSION Robotic donor hepatectomy confers perioperative advantages at the cost of longer operative time.Recipient and economic findings are indirect and considered hypothesis-generating.Transplant-specific,prospective comparisons using a minimum standardized dataset and uniform outcome definitions are needed to resolve remaining uncertainties and to clarify the cost-utility correlation.展开更多
BACKGROUND With increasing rates of liver transplantation and a stagnant donor pool,the annual wait list removals have remained high.Living donor liver transplantation(LDLT)is an established modality in expanding the ...BACKGROUND With increasing rates of liver transplantation and a stagnant donor pool,the annual wait list removals have remained high.Living donor liver transplantation(LDLT)is an established modality in expanding the donor pool and is the primary method of liver donation in large parts of the world.Marginal living donors,including those with hepatic steatosis,have been used to expand the donor pool.However,due to negative effects of steatosis on graft and recipient outcomes,current practice excludes overweight or obese donors with more than 10%macro vesicular steatosis.This has limited a potentially important source to help expand the donor pool.Weight loss is known to improve or resolve steatosis and rapid weight loss with short-term interventions have been used to convert marginal donors to low-risk donors in a small series of studies.There is,however,a lack of a consensus driven standardized approach to such interventions.AIM To assess the available data on using weight loss interventions in potential living liver donors with steatotic livers and investigated the feasibility,efficacy,and safety of using such donors on the donor,graft and recipient outcomes.The principal objective was to assess if using such treated donor livers,could help expand the donor pool.METHODS We performed a comprehensive literature review and meta-analysis on studies examining the role of short-term weight loss interventions in potential living liver donors with hepatic steatosis with the aim of increasing liver donation rates and improving donor,graft,and recipient outcomes.RESULTS A total of 6 studies with 102 potential donors were included.Most subjects were males(71).All studies showed a significant reduction in body mass index postintervention with a mean difference of-2.08(-3.06,1.10,I2=78%).A significant reduction or resolution of hepatic steatosis was seen in 93 of the 102(91.2%).Comparison of pre-and post-intervention liver biopsies showed a significant reduction in steatosis with a mean difference of-21.22(-27.02,-15.43,I2=56%).The liver donation rates post-intervention was 88.5(74.5,95.3,I2=42%).All donors who did not undergo LDLT had either recipient reasons or had fibrosis/steatohepatitis on post intervention biopsies.Post-operative biliary complications in the intervention group were not significantly different compared to controls with an odds ratio of 0.96[(0.14,6.69),I2=0].The overall post-operative donor,graft,and recipient outcomes in treated donors were not significantly different compared to donors with no steatosis.CONCLUSION Use of appropriate short term weight loss interventions in living liver donors is an effective tool in turning marginal donors to low-risk donors and therefore in expanding the donor pool.It is feasible and safe,with comparable donor,graft,and recipient outcomes,to non-obese donors.Larger future prospective studies are needed.展开更多
AIM To perform a systematic review and meta-analysis on minimally vs conventional invasive techniques for harvesting grafts for living donor liver transplantation. METHODS PubMed, Web of Science, EMBASE, and the Cochr...AIM To perform a systematic review and meta-analysis on minimally vs conventional invasive techniques for harvesting grafts for living donor liver transplantation. METHODS PubMed, Web of Science, EMBASE, and the Cochrane Library were searched comprehensively for studies comparing MILDH with conventional living donor hepatectomy (CLDH). Intraoperative and postoperative outcomes (operative time, estimated blood loss, postoperative liver function, length of hospital stay, analgesia use, complications, and survival rate) were analyzed in donors and recipients. Articles were included if they: (1) compared the outcomes of MILDH and CLDH; and (2) reported at least some of the above outcomes. RESULTS Of 937 articles identified, 13, containing 1592 patients, met our inclusion criteria and were included in the meta-analysis. For donors, operative time [weighted mean difference (WMD) = 20.68, 95% CI: -6.25-47.60, p = 0.13] and blood loss (WMD = -32.61, 95% CI: -80.44-5.21, p = 0.18) were comparable in the two groups. In contrast, analgesia use (WMD = -7.79, 95% CI: -14.06-1.87, p = 0.01), postoperative complications [odds ratio (OR) = 0.62, 95% CI: 0.44-0.89, p = 0.009], and length of hospital stay (WMD): -1.25, 95% CI: -2.35-0.14, p = 0.03) significantly favored MILDH. No differences were observed in recipient outcomes, including postoperative complications (OR = 0.93, 95% CI: 0.66-1.31, p = 0.68) and survival rate (hr = 0.96, 95% CI: 0.27-3.47, p = 0.95). Funnel plot and statistical methods showed a low probability of publication bias. CONCLUSION MILDH is safe, effective, and feasible for living donor liver resection with fewer donor postoperative complications, reduced length of hospital stay and analgesia requirement than CLDH.展开更多
Background: Small-for-size graft(SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation(LDLT) as a certain graft size is related to recipients’ prognosis. Graftto-recipi...Background: Small-for-size graft(SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation(LDLT) as a certain graft size is related to recipients’ prognosis. Graftto-recipient weight ratio(GRWR)≥0.8% was considered as a threshold to conduct LDLT. However, this also has been challenged over decades as a result of technique refinements. For a better understanding of SFSG in practice, we conducted this meta-analysis to compare the perioperative outcomes and long-term outcomes between patients adopting the grafts with a lower volume(GRWR < 0.8%, SFSG group) and sufficient volume(GRWR ≥ 0.8%, non-SFSG group) in adult-to-adult LDLT. Data sources: The studies comparing recipients adopting graft with a GRWR < 0.8% and ≥ 0.8% were searched by three authors independently in Pub Med, Web of Science, Embase, the Cochrane Library, MEDLINE and Google Scholar databases until September 2018 and data were analyzed by RevMan 5.3.5. Results: Sixteen studies with a total of 3272 subjects were included in this meta-analysis. In terms of small-for-size syndrome(SFSS), no significant difference was found in subjects enrolled after year 2010(before 2010, OR = 3.00, 95% CI: 1.69–5.35, P = 0.0002;after 2010, OR = 1.23, 95% CI: 0.79–1.90, P = 0.36;P for interaction: 0.02). There was no significant difference in operative duration, blood loss, cold ischemia time, biliary complications, acute rejection, postoperative bleeding, hospitalization time, perioperative mortality, and 1-, 3-and 5-year overall survival rates between two groups. Conclusions: This meta-analysis suggested that adopting SFSG in adult LDLT has comparable outcomes to those with non-SFSG counterparts since 2010.展开更多
Multi-living agent system （MLAS） is a new concept in the field of complex system research, which is peculiarly suitable for the design and analysis of a complex information system in a serious confrontation and tigh...Multi-living agent system （MLAS） is a new concept in the field of complex system research, which is peculiarly suitable for the design and analysis of a complex information system in a serious confrontation and tight constraint environment. However, the universal method to quantitatively measure the living degree of an MLAS remains uncertain, which is critical to the self-organizing process. Therefore, a novel analytic hierarchy process （AHP） based method with dependent pairwise comparison matrix （PCM） for the evaluation of living degree of the MLAS is proposed, which eliminates the shortcoming of fixed PCM in traditional process. Furthermore, to avoid the annoying procedure of the consistency validation, the PCMs are appropriately reconstructed. Through an illustration of the netted radar system, the calculation detail is explicitly presented. Altogether, the advanced evaluation method successfully accomplishes the preset objective and promotes the development of the MLAS theory and AHP as well.展开更多
This paper presents component importance analysis for virtualized system with live migration. The component importance analysis is significant to determine the system design of virtualized system from availability and...This paper presents component importance analysis for virtualized system with live migration. The component importance analysis is significant to determine the system design of virtualized system from availability and cost points of view. This paper discusses the importance of components with respect to system availability. Specifically, we introduce two different component importance analyses for hybrid model (fault trees and continuous-time Markov chains) and continuous-time Markov chains, and show the analysis for existing probabilistic models for virtualized system. In numerical examples, we illustrate the quantitative component importance analysis for virtualized system with live migration.展开更多
Efforts were exerted to enhance the live virtual machines(VMs)migration,including performance improvements of the live migration of services to the cloud.The VMs empower the cloud users to store relevant data and reso...Efforts were exerted to enhance the live virtual machines(VMs)migration,including performance improvements of the live migration of services to the cloud.The VMs empower the cloud users to store relevant data and resources.However,the utilization of servers has increased significantly because of the virtualization of computer systems,leading to a rise in power consumption and storage requirements by data centers,and thereby the running costs.Data center migration technologies are used to reduce risk,minimize downtime,and streamline and accelerate the data center move process.Indeed,several parameters,such as non-network overheads and downtime adjustment,may impact the live migration time and server downtime to a large extent.By virtualizing the network resources,the infrastructure as a service(IaaS)can be used dynamically to allocate the bandwidth to services and monitor the network flow routing.Due to the large amount of filthy retransmission,existing live migration systems still suffer from extensive downtime and significant performance degradation in crossdata-center situations.This study aims to minimize the energy consumption by restricting the VMs migration and switching off the vips depending on a threshold,thereby boosting the residual network bandwidth in the data center with a minimal breach of the service level agreement(SLA).In this research,we analyzed and evaluated the findings observed through simulating different parameters,like availability,downtime,and outage of VMs in data center processes.This new paradigm is composed of two forms of detection strategies in the live migration approach from the source host to the destination source machine.展开更多
This paper describes the entire process of completing a multicast streaming media server and applying it to a cellphone live streaming system. By using the RTSP protocol, the streaming media server controls the connec...This paper describes the entire process of completing a multicast streaming media server and applying it to a cellphone live streaming system. By using the RTSP protocol, the streaming media server controls the connection of video capture client, data stream reception and processing as well as playback interaction. The media server can publish real-time data from a data acquisition terminal or a historical data file in the server to the Web so that users on the network can view all the videos through a variety of terminals anytime and anywhere, without having to wait for all the data downloaded completely. The streaming media server of the system is developed based on an open-source streaming media library Live555. The developed server can run on a Windows or a Linux system. The standard RTSP/RTP protocol is used and the video media format is H264. The paper mainly introduces the design of a streaming media server, including data processing for real time, designing a data source, the implementation of multi-acquisition end and multi-player operation, RTSP interaction and RTP packaging, and the setting up of the data buffer in the server. Experiment results are given to show the effect of the system implementation.展开更多
In Peer-to-Peer(P2P) streaming systems,video data may be lost since peers can join and leave the overlay network randomly,thereby deteriorating the video playback quality.In this paper we propose a new hybrid mesh and...In Peer-to-Peer(P2P) streaming systems,video data may be lost since peers can join and leave the overlay network randomly,thereby deteriorating the video playback quality.In this paper we propose a new hybrid mesh and Distributed Hash Table(DHT) based P2P streaming system,called HQMedia,to provide high playback quality to users by maintaining high data dissemination resilience with a low overhead.In HQMedia,peers are classified into Super Peers(SP) and Common Peers(CP) according to their online time.SPs and CPs form a mesh structure,while SPs alone form a new Streaming DHT(SDHT) structure.In this hybrid architecture,we propose a joint scheduling and compensation mechanism.If any frames cannot be obtained during the scheduling phase,an SDHT-based compensation mechanism is invoked for retrieving the missing frames near the playback point.We evaluate the performance of HQMedia by both theoretical analysis and intensive simulation experiments on large-scale networks to demonstrate the effectiveness and scalability of the proposed system.Numerical results show that HQMedia significantly outperforms existing mesh-based and treebased P2P live streaming systems by improving playback quality with only less than 1% extra maintenance overhead.展开更多
IT infrastructures have been widely deployed in datacentres by cloud service providers for Infrastructure as a Service (IaaS) with Virtual Machines (VMs). With the rapid development of cloud-based tools and techniques...IT infrastructures have been widely deployed in datacentres by cloud service providers for Infrastructure as a Service (IaaS) with Virtual Machines (VMs). With the rapid development of cloud-based tools and techniques, IaaS is changing the current cloud infrastructure to meet the customer demand. In this paper, an efficient management model is presented and evaluated using our unique Trans-Atlantic high-speed optical fibre network connecting three datacentres located in Coleraine (Northern Ireland), Dublin (Ireland) and Halifax (Canada). Our work highlights the design and implementation of a management system that can dynamically create VMs upon request, process live migration and other services over the high-speed inter-networking Datacentres (DCs). The goal is to provide an efficient and intelligent on-demand management system for virtualization that can make decisions about the migration of VMs and get better utilisation of the network.展开更多
BACKGROUND The outcomes of liver transplantation(LT)from different grafts have been studied individually and in combination,but the reports were conflicting with some researchers finding no difference in both short-te...BACKGROUND The outcomes of liver transplantation(LT)from different grafts have been studied individually and in combination,but the reports were conflicting with some researchers finding no difference in both short-term and long-term outcomes between the deceased donor split LT(DD-SLT)and living donor LT(LDLT).AIM To compare the outcomes of DD-SLT and LDLT we performed this systematic review and meta-analysis.METHODS This systematic review was performed in compliance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines.The following databases were searched for articles comparing outcomes of DD-SLT and LDLT:PubMed;Google Scholar;Embase;Cochrane Central Register of Controlled Trials;the Cochrane Database of Systematic Reviews;and Reference Citation Analysis(https://www.referencecitationanalysis.com/).The search terms used were:“liver transplantation;”“liver transplant;”“split liver transplant;”“living donor liver transplant;”“partial liver transplant;”“partial liver graft;”“ex vivo splitting;”and“in vivo splitting.”RESULTS Ten studies were included for the data synthesis and meta-analysis.There were a total of 4836 patients.The overall survival rate at 1 year,3 years and 5 years was superior in patients that received LDLT compared to DD-SLT.At 1 year,the hazard ratios was 1.44(95%confidence interval:1.16-1.78;P=0.001).The graft survival rate at 3 years and 5 years was superior in the LDLT group(3 year hazard ratio:1.28;95%confidence interval:1.01-1.63;P=0.04).CONCLUSION This meta-analysis showed that LDLT has better graft survival and overall survival when compared to DD-SLT.展开更多
With the rapid development of the modem information technologies,to promote the education informatization and share the educational and teaching resources,the live classroom in the distance education emerges as the ti...With the rapid development of the modem information technologies,to promote the education informatization and share the educational and teaching resources,the live classroom in the distance education emerges as the times require.The live classroom expands the space-time boundaries in our education and teaching,and changes the traditional teaching methods.It is a new model of the distance education.In order to recognize and understand the impact of the live teaching on the dance teaching and promote the development of the live teaching in the dance education,this paper,from the perspective of the distance education,uses the theories and methods of the distance education to analyze the characteristics of the live teaching,which is a feasible way.展开更多
Live cell imaging has significantly changed our understanding to cell biology during the past 10 years. However, providing a suitable environment to keep cells heathy is still a challenge in live cell imaging experime...Live cell imaging has significantly changed our understanding to cell biology during the past 10 years. However, providing a suitable environment to keep cells heathy is still a challenge in live cell imaging experiments, and has great influence on the reliability of the experimental results. Many factors are needed to maintain cells healthy, such as temperature, pH, oxygen tension, CO2 and so on.展开更多
The live attenuated hepatitis A virus vaccine H2 strain was developed by passaging a wild-type H2w isolate in cell cultures.Currently,the mechanism underlying its attenuation phenotype remain largely unknown.In this s...The live attenuated hepatitis A virus vaccine H2 strain was developed by passaging a wild-type H2w isolate in cell cultures.Currently,the mechanism underlying its attenuation phenotype remain largely unknown.In this study,we generated a full-length infectious cDNA clone of the H2 strain using in-fusion techniques.The recovered H2 strain(H2ic)from the cDNA clone exhibited an efficient replication in both the hepatoma cell line Huh7.5.1 and the 2BS cell line used for vaccine production,similar to the parental H2 strain.Additionally,H2ic did not cause disease in Ifnar1-/- C57 mice,consistent with the H2 strain.To explore the cell-adaptive mutations of the H2 strain,chimeric viruses were generated by replacing its non-structural proteins with corresponding regions from H2w using the infectious cDNA clone as a genetic backbone.The chimeric viruses carrying the 3C or 3D proteins from H2w showed decreased replication in Huh7.5.1 and 2BS cell lines compared to H2ic.Other chimeric viruses containing the 2B,2C,or 3A proteins from H2w failed to be recovered.Furthermore,there were no significant differences in disease manifestation in mice between H2ic and the recovered chimeric viruses.These results demonstrate that adaptive mutations in the 2B,2C,and 3A proteins are essential for efficient replication of the H2 strain in cell cultures.Mutations in the 3C and 3D proteins contribute to enhanced replication in cell cultures but did not influence the attenuated phenotypes in mice.Together,this study presents the first reverse genetic system of the H2 strain and identifies viral proteins essential for adaptation to cell cultures.展开更多
The probabilities for the technology to be spoofed are widely acknowledged in biometric verification system. Important efforts have been conducted to study such threats and to develop countermeasures to direct attacks...The probabilities for the technology to be spoofed are widely acknowledged in biometric verification system. Important efforts have been conducted to study such threats and to develop countermeasures to direct attacks to the biometric verification system to ensure the security of these systems against spoof attacks and reduce this risk, by using another module that is added to the biometric verification system called the “liveness detection” which uses different anatomical properties to distinguish between real and fake traits. Thus, the robustness of the system against direct attacks can be improved through increasing the security level offered to the final user. This paper is an attempt to construct support biometric security system to protect the iris biometric verification system from spoof attacks, through integrating the iris verification system with addition module called liveness detection which composed of two sub-modules (static and dynamic). A test has been performed, for iris verification phase performed on two types of database (MMU DB) for 180 samples and (CASIA DB) for 90 samples, and gave accuracy (99.44%) with FAR of (0.0277) and FRR (0.0055) for MMU DB, and accuracy (97.77%) with FAR of (0.0333) and FRR (0.0222) for CASIA DB.展开更多
基金supported by Henan Province Major Science and Technology Project(241100210100).
文摘Over the past few years,video live streaming has gained immense popularity as a leading internet application.In current solutions offered by cloud service providers,the Group of Pictures(GOP)length of the video source often significantly impacts end-to-end(E2E)latency.However,designing an optimized GOP structure to reduce this effect remains a significant challenge.This paper presents two key contributions.First,it explores how the GOP length at the video source influences E2E latency in mainstream cloud streaming services.Experimental results reveal that the mean E2E latency increases linearly with longer GOP lengths.Second,this paper proposes EGOP(an Enhanced GOP structure)that can be implemented in streaming media servers.Experiments demonstrate that EGOP maintains a consistent E2E latency,unaffected by the GOP length of the video source.Specifically,even with a GOP length of 10 s,the E2E latency remains at 1.35 s,achieving a reduction of 6.98 s compared to Volcano-Engine(the live streaming service provider for TikTok).This makes EGOP a promising solution for low-latency live streaming.
文摘BACKGROUND Robotic assistance is increasingly used for donor and recipient hepatectomy in liver transplantation,yet existing evidence is fragmented and variably indirect.AIM To evaluate clinical outcomes,surgical performance,and economic effects of robotic-assisted donor and recipient hepatectomy in the transplant pathway.METHODS Following Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 and a priori registration,systematic reviews were included with or without meta-analysis.Four databases were searched through July 2025.Methodological quality was appraised with a measurement tool to assess systematic reviews(AMSTAR 2),and certainty was graded with grading of recommendations assessment,development and evaluation(GRADE).Evidence overlap was calculated via a citation-matrix-based corrected covered area(CCA).Effect sizes were prespecified as risk ratios(RR)for dichotomous outcomes and mean differences for continuous outcomes.RESULTS Five reviews met the inclusion criteria,four with meta-analyses and one consensus review used only for context.Donor(direct)findings were more favorable for robotics in terms of estimated blood loss(≈-117 mL)and length of stay(≈-0.6 days),although with longer operative time(≈+105 minutes).Absolute risks for donor complications were not estimable from ratio-only data.Recipient(indirect)meta-analysis indicated robotics to be favorable in terms of conversion(RR≈0.41)and severe morbidity(RR≈0.81),with a trend toward lower overall morbidity(RR≈0.92)and no difference in 30-day mortality.Differences in length of stay and operative time were small and heterogeneous.Economic evidence(indirect,network meta-analysis)suggested higher procedural costs for robotic vs laparoscopic intervention,but lower hospitalization costs vs open intervention,with laparoscopy the least expensive overall.AMSTAR 2 ratings were moderate-to-high across the reviews,GRADE certainty was low for key donor continuous outcomes,and low-to-moderate for recipient and economic outcomes.Overlap was slight(graded-corpus CCA=0.0%;including a contextual non-transplant review increased CCA to≈1.25%).CONCLUSION Robotic donor hepatectomy confers perioperative advantages at the cost of longer operative time.Recipient and economic findings are indirect and considered hypothesis-generating.Transplant-specific,prospective comparisons using a minimum standardized dataset and uniform outcome definitions are needed to resolve remaining uncertainties and to clarify the cost-utility correlation.
文摘BACKGROUND With increasing rates of liver transplantation and a stagnant donor pool,the annual wait list removals have remained high.Living donor liver transplantation(LDLT)is an established modality in expanding the donor pool and is the primary method of liver donation in large parts of the world.Marginal living donors,including those with hepatic steatosis,have been used to expand the donor pool.However,due to negative effects of steatosis on graft and recipient outcomes,current practice excludes overweight or obese donors with more than 10%macro vesicular steatosis.This has limited a potentially important source to help expand the donor pool.Weight loss is known to improve or resolve steatosis and rapid weight loss with short-term interventions have been used to convert marginal donors to low-risk donors in a small series of studies.There is,however,a lack of a consensus driven standardized approach to such interventions.AIM To assess the available data on using weight loss interventions in potential living liver donors with steatotic livers and investigated the feasibility,efficacy,and safety of using such donors on the donor,graft and recipient outcomes.The principal objective was to assess if using such treated donor livers,could help expand the donor pool.METHODS We performed a comprehensive literature review and meta-analysis on studies examining the role of short-term weight loss interventions in potential living liver donors with hepatic steatosis with the aim of increasing liver donation rates and improving donor,graft,and recipient outcomes.RESULTS A total of 6 studies with 102 potential donors were included.Most subjects were males(71).All studies showed a significant reduction in body mass index postintervention with a mean difference of-2.08(-3.06,1.10,I2=78%).A significant reduction or resolution of hepatic steatosis was seen in 93 of the 102(91.2%).Comparison of pre-and post-intervention liver biopsies showed a significant reduction in steatosis with a mean difference of-21.22(-27.02,-15.43,I2=56%).The liver donation rates post-intervention was 88.5(74.5,95.3,I2=42%).All donors who did not undergo LDLT had either recipient reasons or had fibrosis/steatohepatitis on post intervention biopsies.Post-operative biliary complications in the intervention group were not significantly different compared to controls with an odds ratio of 0.96[(0.14,6.69),I2=0].The overall post-operative donor,graft,and recipient outcomes in treated donors were not significantly different compared to donors with no steatosis.CONCLUSION Use of appropriate short term weight loss interventions in living liver donors is an effective tool in turning marginal donors to low-risk donors and therefore in expanding the donor pool.It is feasible and safe,with comparable donor,graft,and recipient outcomes,to non-obese donors.Larger future prospective studies are needed.
基金Science and Technology Planning Project of Guangzhou,No.201604020001
文摘AIM To perform a systematic review and meta-analysis on minimally vs conventional invasive techniques for harvesting grafts for living donor liver transplantation. METHODS PubMed, Web of Science, EMBASE, and the Cochrane Library were searched comprehensively for studies comparing MILDH with conventional living donor hepatectomy (CLDH). Intraoperative and postoperative outcomes (operative time, estimated blood loss, postoperative liver function, length of hospital stay, analgesia use, complications, and survival rate) were analyzed in donors and recipients. Articles were included if they: (1) compared the outcomes of MILDH and CLDH; and (2) reported at least some of the above outcomes. RESULTS Of 937 articles identified, 13, containing 1592 patients, met our inclusion criteria and were included in the meta-analysis. For donors, operative time [weighted mean difference (WMD) = 20.68, 95% CI: -6.25-47.60, p = 0.13] and blood loss (WMD = -32.61, 95% CI: -80.44-5.21, p = 0.18) were comparable in the two groups. In contrast, analgesia use (WMD = -7.79, 95% CI: -14.06-1.87, p = 0.01), postoperative complications [odds ratio (OR) = 0.62, 95% CI: 0.44-0.89, p = 0.009], and length of hospital stay (WMD): -1.25, 95% CI: -2.35-0.14, p = 0.03) significantly favored MILDH. No differences were observed in recipient outcomes, including postoperative complications (OR = 0.93, 95% CI: 0.66-1.31, p = 0.68) and survival rate (hr = 0.96, 95% CI: 0.27-3.47, p = 0.95). Funnel plot and statistical methods showed a low probability of publication bias. CONCLUSION MILDH is safe, effective, and feasible for living donor liver resection with fewer donor postoperative complications, reduced length of hospital stay and analgesia requirement than CLDH.
文摘Background: Small-for-size graft(SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation(LDLT) as a certain graft size is related to recipients’ prognosis. Graftto-recipient weight ratio(GRWR)≥0.8% was considered as a threshold to conduct LDLT. However, this also has been challenged over decades as a result of technique refinements. For a better understanding of SFSG in practice, we conducted this meta-analysis to compare the perioperative outcomes and long-term outcomes between patients adopting the grafts with a lower volume(GRWR < 0.8%, SFSG group) and sufficient volume(GRWR ≥ 0.8%, non-SFSG group) in adult-to-adult LDLT. Data sources: The studies comparing recipients adopting graft with a GRWR < 0.8% and ≥ 0.8% were searched by three authors independently in Pub Med, Web of Science, Embase, the Cochrane Library, MEDLINE and Google Scholar databases until September 2018 and data were analyzed by RevMan 5.3.5. Results: Sixteen studies with a total of 3272 subjects were included in this meta-analysis. In terms of small-for-size syndrome(SFSS), no significant difference was found in subjects enrolled after year 2010(before 2010, OR = 3.00, 95% CI: 1.69–5.35, P = 0.0002;after 2010, OR = 1.23, 95% CI: 0.79–1.90, P = 0.36;P for interaction: 0.02). There was no significant difference in operative duration, blood loss, cold ischemia time, biliary complications, acute rejection, postoperative bleeding, hospitalization time, perioperative mortality, and 1-, 3-and 5-year overall survival rates between two groups. Conclusions: This meta-analysis suggested that adopting SFSG in adult LDLT has comparable outcomes to those with non-SFSG counterparts since 2010.
基金supported by the National Natural Science Foundation of China(61172176)
文摘Multi-living agent system （MLAS） is a new concept in the field of complex system research, which is peculiarly suitable for the design and analysis of a complex information system in a serious confrontation and tight constraint environment. However, the universal method to quantitatively measure the living degree of an MLAS remains uncertain, which is critical to the self-organizing process. Therefore, a novel analytic hierarchy process （AHP） based method with dependent pairwise comparison matrix （PCM） for the evaluation of living degree of the MLAS is proposed, which eliminates the shortcoming of fixed PCM in traditional process. Furthermore, to avoid the annoying procedure of the consistency validation, the PCMs are appropriately reconstructed. Through an illustration of the netted radar system, the calculation detail is explicitly presented. Altogether, the advanced evaluation method successfully accomplishes the preset objective and promotes the development of the MLAS theory and AHP as well.
文摘This paper presents component importance analysis for virtualized system with live migration. The component importance analysis is significant to determine the system design of virtualized system from availability and cost points of view. This paper discusses the importance of components with respect to system availability. Specifically, we introduce two different component importance analyses for hybrid model (fault trees and continuous-time Markov chains) and continuous-time Markov chains, and show the analysis for existing probabilistic models for virtualized system. In numerical examples, we illustrate the quantitative component importance analysis for virtualized system with live migration.
文摘Efforts were exerted to enhance the live virtual machines(VMs)migration,including performance improvements of the live migration of services to the cloud.The VMs empower the cloud users to store relevant data and resources.However,the utilization of servers has increased significantly because of the virtualization of computer systems,leading to a rise in power consumption and storage requirements by data centers,and thereby the running costs.Data center migration technologies are used to reduce risk,minimize downtime,and streamline and accelerate the data center move process.Indeed,several parameters,such as non-network overheads and downtime adjustment,may impact the live migration time and server downtime to a large extent.By virtualizing the network resources,the infrastructure as a service(IaaS)can be used dynamically to allocate the bandwidth to services and monitor the network flow routing.Due to the large amount of filthy retransmission,existing live migration systems still suffer from extensive downtime and significant performance degradation in crossdata-center situations.This study aims to minimize the energy consumption by restricting the VMs migration and switching off the vips depending on a threshold,thereby boosting the residual network bandwidth in the data center with a minimal breach of the service level agreement(SLA).In this research,we analyzed and evaluated the findings observed through simulating different parameters,like availability,downtime,and outage of VMs in data center processes.This new paradigm is composed of two forms of detection strategies in the live migration approach from the source host to the destination source machine.
文摘This paper describes the entire process of completing a multicast streaming media server and applying it to a cellphone live streaming system. By using the RTSP protocol, the streaming media server controls the connection of video capture client, data stream reception and processing as well as playback interaction. The media server can publish real-time data from a data acquisition terminal or a historical data file in the server to the Web so that users on the network can view all the videos through a variety of terminals anytime and anywhere, without having to wait for all the data downloaded completely. The streaming media server of the system is developed based on an open-source streaming media library Live555. The developed server can run on a Windows or a Linux system. The standard RTSP/RTP protocol is used and the video media format is H264. The paper mainly introduces the design of a streaming media server, including data processing for real time, designing a data source, the implementation of multi-acquisition end and multi-player operation, RTSP interaction and RTP packaging, and the setting up of the data buffer in the server. Experiment results are given to show the effect of the system implementation.
基金supported by the National Programs for Science and Technology under Grant No. 2009ZX03004-002the National Natural Science Foundation of China Major Project under Grant No. 60833002+2 种基金the National Natural Science Foundation of China under Grant No.60772142the National Science and Technology Major Projects under Grant No. 2008ZX03003-005the Science and Technology Research Project of Chongqing Education Commission under Grant No. KJ120825
文摘In Peer-to-Peer(P2P) streaming systems,video data may be lost since peers can join and leave the overlay network randomly,thereby deteriorating the video playback quality.In this paper we propose a new hybrid mesh and Distributed Hash Table(DHT) based P2P streaming system,called HQMedia,to provide high playback quality to users by maintaining high data dissemination resilience with a low overhead.In HQMedia,peers are classified into Super Peers(SP) and Common Peers(CP) according to their online time.SPs and CPs form a mesh structure,while SPs alone form a new Streaming DHT(SDHT) structure.In this hybrid architecture,we propose a joint scheduling and compensation mechanism.If any frames cannot be obtained during the scheduling phase,an SDHT-based compensation mechanism is invoked for retrieving the missing frames near the playback point.We evaluate the performance of HQMedia by both theoretical analysis and intensive simulation experiments on large-scale networks to demonstrate the effectiveness and scalability of the proposed system.Numerical results show that HQMedia significantly outperforms existing mesh-based and treebased P2P live streaming systems by improving playback quality with only less than 1% extra maintenance overhead.
文摘IT infrastructures have been widely deployed in datacentres by cloud service providers for Infrastructure as a Service (IaaS) with Virtual Machines (VMs). With the rapid development of cloud-based tools and techniques, IaaS is changing the current cloud infrastructure to meet the customer demand. In this paper, an efficient management model is presented and evaluated using our unique Trans-Atlantic high-speed optical fibre network connecting three datacentres located in Coleraine (Northern Ireland), Dublin (Ireland) and Halifax (Canada). Our work highlights the design and implementation of a management system that can dynamically create VMs upon request, process live migration and other services over the high-speed inter-networking Datacentres (DCs). The goal is to provide an efficient and intelligent on-demand management system for virtualization that can make decisions about the migration of VMs and get better utilisation of the network.
文摘BACKGROUND The outcomes of liver transplantation(LT)from different grafts have been studied individually and in combination,but the reports were conflicting with some researchers finding no difference in both short-term and long-term outcomes between the deceased donor split LT(DD-SLT)and living donor LT(LDLT).AIM To compare the outcomes of DD-SLT and LDLT we performed this systematic review and meta-analysis.METHODS This systematic review was performed in compliance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines.The following databases were searched for articles comparing outcomes of DD-SLT and LDLT:PubMed;Google Scholar;Embase;Cochrane Central Register of Controlled Trials;the Cochrane Database of Systematic Reviews;and Reference Citation Analysis(https://www.referencecitationanalysis.com/).The search terms used were:“liver transplantation;”“liver transplant;”“split liver transplant;”“living donor liver transplant;”“partial liver transplant;”“partial liver graft;”“ex vivo splitting;”and“in vivo splitting.”RESULTS Ten studies were included for the data synthesis and meta-analysis.There were a total of 4836 patients.The overall survival rate at 1 year,3 years and 5 years was superior in patients that received LDLT compared to DD-SLT.At 1 year,the hazard ratios was 1.44(95%confidence interval:1.16-1.78;P=0.001).The graft survival rate at 3 years and 5 years was superior in the LDLT group(3 year hazard ratio:1.28;95%confidence interval:1.01-1.63;P=0.04).CONCLUSION This meta-analysis showed that LDLT has better graft survival and overall survival when compared to DD-SLT.
文摘With the rapid development of the modem information technologies,to promote the education informatization and share the educational and teaching resources,the live classroom in the distance education emerges as the times require.The live classroom expands the space-time boundaries in our education and teaching,and changes the traditional teaching methods.It is a new model of the distance education.In order to recognize and understand the impact of the live teaching on the dance teaching and promote the development of the live teaching in the dance education,this paper,from the perspective of the distance education,uses the theories and methods of the distance education to analyze the characteristics of the live teaching,which is a feasible way.
文摘Live cell imaging has significantly changed our understanding to cell biology during the past 10 years. However, providing a suitable environment to keep cells heathy is still a challenge in live cell imaging experiments, and has great influence on the reliability of the experimental results. Many factors are needed to maintain cells healthy, such as temperature, pH, oxygen tension, CO2 and so on.
基金funding from the National Key Research and Development Project of China(2021YFC2300202)the National Natural Science Foundation of China(82171820)+2 种基金C.-F.Q.received support from the National Science Fund for Distinguished Young Scholar(81925025)the Innovative Research Group(81621005)from the National Natural Science Foundation Chinathe Innovation Fund for Medical Sciences(No.2019-I2M-5-049)from the Chinese Academy of Medical Sciences.
文摘The live attenuated hepatitis A virus vaccine H2 strain was developed by passaging a wild-type H2w isolate in cell cultures.Currently,the mechanism underlying its attenuation phenotype remain largely unknown.In this study,we generated a full-length infectious cDNA clone of the H2 strain using in-fusion techniques.The recovered H2 strain(H2ic)from the cDNA clone exhibited an efficient replication in both the hepatoma cell line Huh7.5.1 and the 2BS cell line used for vaccine production,similar to the parental H2 strain.Additionally,H2ic did not cause disease in Ifnar1-/- C57 mice,consistent with the H2 strain.To explore the cell-adaptive mutations of the H2 strain,chimeric viruses were generated by replacing its non-structural proteins with corresponding regions from H2w using the infectious cDNA clone as a genetic backbone.The chimeric viruses carrying the 3C or 3D proteins from H2w showed decreased replication in Huh7.5.1 and 2BS cell lines compared to H2ic.Other chimeric viruses containing the 2B,2C,or 3A proteins from H2w failed to be recovered.Furthermore,there were no significant differences in disease manifestation in mice between H2ic and the recovered chimeric viruses.These results demonstrate that adaptive mutations in the 2B,2C,and 3A proteins are essential for efficient replication of the H2 strain in cell cultures.Mutations in the 3C and 3D proteins contribute to enhanced replication in cell cultures but did not influence the attenuated phenotypes in mice.Together,this study presents the first reverse genetic system of the H2 strain and identifies viral proteins essential for adaptation to cell cultures.
文摘The probabilities for the technology to be spoofed are widely acknowledged in biometric verification system. Important efforts have been conducted to study such threats and to develop countermeasures to direct attacks to the biometric verification system to ensure the security of these systems against spoof attacks and reduce this risk, by using another module that is added to the biometric verification system called the “liveness detection” which uses different anatomical properties to distinguish between real and fake traits. Thus, the robustness of the system against direct attacks can be improved through increasing the security level offered to the final user. This paper is an attempt to construct support biometric security system to protect the iris biometric verification system from spoof attacks, through integrating the iris verification system with addition module called liveness detection which composed of two sub-modules (static and dynamic). A test has been performed, for iris verification phase performed on two types of database (MMU DB) for 180 samples and (CASIA DB) for 90 samples, and gave accuracy (99.44%) with FAR of (0.0277) and FRR (0.0055) for MMU DB, and accuracy (97.77%) with FAR of (0.0333) and FRR (0.0222) for CASIA DB.
