Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this ...Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this injury will therefore reduce acute complications in hepatic resection and transplantation,as well as expanding the potential pool of usable donor grafts.The initial liver injury is initiated by reactive oxygen species which cause direct cellular injury and also activate a cascade of molecular mediators leading to microvascular changes,increased apoptosis and acute inflammatory changes with increased hepatocyte necrosis.Some adaptive pathways are activated during reperfusion that reduce the reperfusion injury.IRI involves a complex interplay between neutrophils,natural killer T-cells cells,CD4+ T cell subtypes,cytokines,nitric oxide synthases,haem oxygenase-1,survival kinases such as the signal transducer and activator of transcription,Phosphatidylinositol 3-kinases/Akt and nuclear factor κβ pathways.Transgenic animals,particularly genetic knockout models,have become a powerful tool at elucidating mechanisms of liver ischaemia reperfusion injury and are complementary to pharmacological studies.Targeted disruption of the protein at the genetic level is more specific and maintained than pharmacological inhibitors or stimulants of the same protein.This article reviews the evidence from knockout models of liver IRI about the cellular and molecular mechanisms underlying liver IRI.展开更多
In this paper, we show that supercritical fluids have a greater significance in the generation of pegmatites,and for ore-forming processes related to granites than is usually assumed. We show that the supercritical me...In this paper, we show that supercritical fluids have a greater significance in the generation of pegmatites,and for ore-forming processes related to granites than is usually assumed. We show that the supercritical melt or fluid is a silicate phase in which volatiles; principally H_2O are completely miscible in all proportions at magmatic temperatures and pressures. This phase evolves from felsic melts and changes into hydrothermal fluids, and its unique properties are particularly important in sequestering and concentrating low abundance elements, such as metals. In our past research, we have focused on processes observed at upper crustal levels, however extensive work by us and other researchers have demonstrated that supercritical melt/fluids should be abundant in melting zones at deep-crustal levels too. We propose that these fluids may provide a connecting link between lower and upper crustal magmas,and a highly efficient transport mechanism for usually melt incompatible elements. In this paper, we explore the unique features of this fluid which allow the partitioning of variouselements and compounds, potentially up to extreme levels,and may explain various features both of mineralization and the magmas that produced them.展开更多
This review of new understanding and forecasting of tropical cyclones(TCs) is based on presentations at the International Top-level Forum on Rapid Change Phenomena in Tropical Cyclones in Haikou, China. The major topi...This review of new understanding and forecasting of tropical cyclones(TCs) is based on presentations at the International Top-level Forum on Rapid Change Phenomena in Tropical Cyclones in Haikou, China. The major topics are the sudden changes in tracks, rapid changes in structure and intensity, rapid changes in rainfall, and advances in forecasting and forecaster requirements. Although improved track forecast guidance has been achieved with the Australian ACCESS-TC model and in track forecasts to 120 h by the China Meteorological Administration, there is a continuing need for better understanding and improved track forecast guidance. Advances in understanding of processes related to rapid intensification(RI), secondary eyewall formation, mechanisms controlling inner-core structure and size changes, and structure and intensity changes at landfall have been achieved, but progress in prediction of rapid changes in structure and intensity has been slow. Taking into account complex interactions involved in TC-related rainfall, a prioritized list of physical processes that govern rainfall from landfalling TCs in China has been developed. While forecaster participants were generally encouraged by the progress being made, they expressed a strong desire for a transition of that new knowledge to timely and reliable forecast guidance products.展开更多
This paper focuses on understanding and evaluating the dynamic effect of the heavy-haul train system on the seismic performance of a long-span railway bridge. A systematic study on the effect of heavy-haul trains on b...This paper focuses on understanding and evaluating the dynamic effect of the heavy-haul train system on the seismic performance of a long-span railway bridge. A systematic study on the effect of heavy-haul trains on bridge seismic response has been conducted, considering the influence of vehicle modeling strategies and dynamic characteristics of the seismic waves. For this purpose, the performance of a long-span cable-stayed railway bridge is assessed with stationary trains atop it, where the heavy-haul vehicles are modeled in two different ways: the multi-rigid body model with suspension system and additional mass model. Comparison of the bridge response in the presence or absence of the train system has been conducted, and the vehicle loading situation, which includes full-load and no-load, is also discussed. The result shows that during the earthquake, the peak moment of the main girder and peak stress of stay cables increase by 80% and by 40% in the presence of fully loaded heavy-haul trains, respectively. At the same time, a considerable decrease appears in the peak acceleration of the main girder. This proves the existence of the damping effect of the heavy-haul train system, and this effect is more obvious for the fully loaded vehicles. Finally, this paper proposes an efficient vehicle modeling method with 2 degrees of freedom(DOF) for simplifying the treatment of the train system in bridge seismic checking.展开更多
During liver resection surgery for cancer or liver transplantation,the liver is subject to ischaemia (reduction in blood flow) followed by reperfusion (restoration of blood flow),which results in liver injury [ischemi...During liver resection surgery for cancer or liver transplantation,the liver is subject to ischaemia (reduction in blood flow) followed by reperfusion (restoration of blood flow),which results in liver injury [ischemiareperfusion (IR) or IR injury]. Modulation of IR injury can be achieved in various ways. These include hypothermia,ischaemic preconditioning (IPC) (brief cycles of ischaemia followed by reperfusion of the organ before the prolonged period of ischaemia i.e. a conditioning response),ischaemic postconditioning (conditioning after the prolonged period of ischaemia but before the reperfusion),pharmacological agents to decrease IR injury,genetic modulation of IR injury,and machine perfusion (pulsatile perfusion). Hypothermia decreases the metabolic functions and the oxygen consumption of organs. Static cold storage in University of Wisconsin solution reduces IR injury and has prolonged organ storage and improved the function of transplanted grafts. There is currently no evidence for any clinical advantage in the use of alternate solutions for static cold storage. Although experimental data from animal models suggest that IPC,ischaemic postconditioning,various pharma-cological agents,gene therapy,and machine perfusion decrease IR injury,none of these interventions can be recommended in clinical practice. This is because of the lack of randomized controlled trials assessing the safety and efficacy of ischaemic postconditioning,gene therapy,and machine perfusion. Randomized controlled trials and systematic reviews of randomized controlled trials assessing the safety and efficacy of IPC and various pharmacological agents have demonstrated biochemical or histological improvements but this has not translated to clinical benefit. Further well designed randomized controlled trials are necessary to assess the various new protective strategies in liver resection.展开更多
We provide a review of our recent 100-Gb/s, high spectral efficiency （SE） experiment targeting transoceanic and regional undersea transmission distances. We demonstrated that simple pre-filtering at the transmitter ...We provide a review of our recent 100-Gb/s, high spectral efficiency （SE） experiment targeting transoceanic and regional undersea transmission distances. We demonstrated that simple pre-filtering at the transmitter together with a maximum a posteriori probability （MAP） detection algorithm can significantly improve SE. We transmitted 96×100-Gb/s pre-filtered polarization division multiplexed return-to-zero quadrature phase shift keyed （PDM-RZ-QPSK） channels with 300% SE over 10608 km using 52-km spans of 150-μm 2 fiber and simple single-stage erbium-doped fiber amplifiers （EDFAs）. We also achieved 400% SE over 4368 km using similar techniques.展开更多
While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic...While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic consequences of non-point pollution in China or the policy options that could be employed to combat it. In this work a sustainable strategy to control non-point pollution from crop production, which involved taxing excessive inputs of irrigation water and fertilizer, was proposed. The approach taken to assess these measures combined biophysical and economic models,having a trade-off between economic returns and an improved environment. A proven and practical spatially referenced water and nutrient management model was used to determine the quantities of excessive irrigation water and fertilizer for specific soil and land use. Also, a set of indicators were proposed for evaluating the effects of agricultural economic output and agricultural practices on the environment.展开更多
To investigate the additional clinical impact of hepatic ischaemia reperfusion injury (HIRI) on patients sustaining acute kidney injury (AKI) following liver transplantation. METHODSThis was a single-centre retrospect...To investigate the additional clinical impact of hepatic ischaemia reperfusion injury (HIRI) on patients sustaining acute kidney injury (AKI) following liver transplantation. METHODSThis was a single-centre retrospective study of consecutive adult patients undergoing orthotopic liver transplantation (OLT) between January 2013 and June 2014. Early AKI was identified by measuring serum creatinine at 24 h post OLT (> 1.5 × baseline) or by the use of continuous veno-venous haemofiltration (CVVHF) during the early post-operative period. Patients with and without AKI were compared to identify risk factors associated with this complication. Peak serum aspartate aminotransferase (AST) within 24 h post-OLT was used as a surrogate marker for HIRI and severity was classified as minor (< 1000 IU/L), moderate (1000-5000 IU/L) or severe (> 5000 IU/L). The impact on time to extubation, intensive care length of stay, incidence of chronic renal failure and 90-d mortality were examined firstly for each of the two complications (AKI and HIRI) alone and then as a combined outcome. RESULTSOut of the 116 patients included in the study, 50% developed AKI, 24% required CVVHF and 70% sustained moderate or severe HIRI. Median peak AST levels were 1248 IU/L and 2059 IU/L in the No AKI and AKI groups respectively (P = 0.0003). Furthermore, peak serum AST was the only consistent predictor of AKI on multivariate analysis P = 0.02. AKI and HIRI were individually associated with a longer time to extubation, increased length of intensive care unit stay and reduced survival. However, the patients who sustained both AKI and moderate or severe HIRI had a longer median time to extubation (P < 0.001) and intensive care length of stay (P = 0.001) than those with either complication alone. Ninety-day survival in the group sustaining both AKI and moderate or severe HIRI was 89%, compared to 100% in the groups with either or neither complication (P = 0.049). CONCLUSIONHIRI has an important role in the development of AKI post-OLT and has a negative impac展开更多
Passive all-optical signal processors that overcome the electronic bottleneck can potentially be the enabling components for the next-generation high-speed and lower power consumption systems. Here, we propose and exp...Passive all-optical signal processors that overcome the electronic bottleneck can potentially be the enabling components for the next-generation high-speed and lower power consumption systems. Here, we propose and experimentally demonstrate a CMOS-compatible waveguide and its application to the all-optical analog-to-digital converter(ADC) under the nonlinear spectral splitting and filtering scheme. As the key component of the proposed ADC, a 50 cm long high-index doped silica glass spiral waveguide is composed of a thin silicon-nanocrystal(Si-nc) layer embedded in the core center for enhanced nonlinearity. The device simultaneously possesses low loss(0.16 dB/cm at 1550 nm), large nonlinearity(305 W^-1∕km at 1550 nm), and negligible nonlinear absorption.A 2-bit ADC basic unit is achieved when pumped by the proposed waveguide structure at the telecom band and without any additional amplification. Simulation results that are consistent with the experimental ones are also demonstrated, which further confirm the feasibility of the proposed scheme for larger quantization resolution.This demonstrated approach enables a fully monolithic solution for all-optical ADC in the future, which can digitize broadband optical signals directly at low power consumption. This has great potential on the applications of high-speed optical communications, networks, and signal processing systems.展开更多
Water samples were collected over P. ponchetii bloom period beginning in November 1988, in 15m water column, from 10km offshore of Davis Station, Vestfold Hill, Antarctica. The concentrations of acrylic acid and dimet...Water samples were collected over P. ponchetii bloom period beginning in November 1988, in 15m water column, from 10km offshore of Davis Station, Vestfold Hill, Antarctica. The concentrations of acrylic acid and dimethyl sulphide (DMS), which are toxic compounds in the water samples, were determined by HPLC and GC. The result shows that the concentration of acrylic acid varies in 0. 001 - 0. 510μmol ?L-1 and the concentration of DMS in 0. 003-0. 588 μmol ?L-1 during P. pouchetii bloom. Both the increased since late December 1988 and reached the highest concentration in early January 1989, then they decreased rapidly and returned to lower level from middle January to February in agreement with variation in cell number of the unicell alga P. pouchetii. The correlation coefficients between acrylic acid and P. pouchetii and between DMS and P. pouchetii are all 0. 998. It is undoubted that P. pouchetii produced acrylic acid and DMS. The highest productivity of acrylic acid and DMS were 9. 76X 10-8 umol cell-1 and 13. 09 ×10-8 μmol ?cell-1, respectively, during P. pouchelii bloom. A cellular product, dimethylsulphonium propionate (DMSP), is decomposed into acrylic acid and DMS, and the formation of DMSP is probably from methionine which could be utilized by P. pouchelii.展开更多
Integrated switches play a crucial role in the development of reconfigurable optical add-drop multiplexers(ROADMs)that have greater flexibility and compactness,ultimately leading to robust single-chip solutions.Despit...Integrated switches play a crucial role in the development of reconfigurable optical add-drop multiplexers(ROADMs)that have greater flexibility and compactness,ultimately leading to robust single-chip solutions.Despite decades of research on switches with various structures and platforms,achieving a balance between dense integration,low insertion loss(IL),and polarization-dependent loss(PDL)remains a significant challenge.In this paper,we propose and demonstrate a 32×4 optical switch using high-index doped silica glass(HDSG)for ROADM applications.This switch is designed to route any of the 32 inputs to the express ports or drop any channels from 32 inputs to the target 4 drop ports or add any of the 4 ports to any of the 32 express channels.The switch comprises 188 MachZehnder Interferometer(MZI)type switch elements,88 optical vias for the 44 optical bridges,and 618 waveguidewaveguide crossings with three-dimensional(3D)structures.At 1550 nm,the fiber-to-fiber loss for each express channel is below 2 dB,and across the C and L bands,below 3 dB.For each input channel to all 4 drop/add channels at 1550 nm,the loss is less than 3.5 dB and less than 5 dB across the C and L bands.The PDLs for all express and input channels to the 4 drop/add channels are below 0.3 dB over the C band,and the crosstalk is under−50 dB for both the C and L bands.展开更多
AIM: To examine the incidence of hepatitis E(HepE) in individuals with acute liver injury severe enough to warrant treatment at a transplant unit.METHODS: Hepatitis E virus(HEV) is an emerging pathogen in developed co...AIM: To examine the incidence of hepatitis E(HepE) in individuals with acute liver injury severe enough to warrant treatment at a transplant unit.METHODS: Hepatitis E virus(HEV) is an emerging pathogen in developed countries causing severe illness, particularly in immunocompromised patients or those with underlying chronic liver disease. HepE infection isoften under diagnosed, as clinicians can be reluctant to test patients who have not travelled to regions traditionally considered hyperendemic for HepE. There are few data regarding the significance of HEV in patients with very severe acute liver injury in developed countries. Eighty patients with acute severe liver injury attending the Scottish Liver Transplant unit were tested for HEV and anti-HEV IgG and IgM. Severe acute liver injury was defined as a sudden deterioration in liver function confirmed by abnormal liver function tests and coagulopathy or presence of hepatic encephalopathy. Eighty percent of these patients were diagnosed with paracetomol overdose. No patients had a history of chronic or decompensated chronic liver disease at time of sampling. IgG positive samples were quantified against the World Health Organization anti-HEV IgG standard. Samples were screened for HEV viral RNA by quantitative reverse transcription polymerase chain reaction.RESULTS: Four cases of hepatitis E were identified. Three of the four cases were only diagnosed on retrospective testing and were initially erroneously ascribed to drug-induced liver injury and decompensated chronic liver disease, with the cause of the decompensation uncertain. One case was caused by HEV genotype 1 in a traveller returning from Asia, the other three were autochthonous and diagnosed on retrospective testing. In two of these cases(where RNA was detected) HEV was found to be genotype 3, the most prevalent genotype in developed countries. Three patients survived, two of whom had been misdiagnosed as having drug induced liver injury. The fourth patient died from sepsis and liver failure precipitated展开更多
文摘Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this injury will therefore reduce acute complications in hepatic resection and transplantation,as well as expanding the potential pool of usable donor grafts.The initial liver injury is initiated by reactive oxygen species which cause direct cellular injury and also activate a cascade of molecular mediators leading to microvascular changes,increased apoptosis and acute inflammatory changes with increased hepatocyte necrosis.Some adaptive pathways are activated during reperfusion that reduce the reperfusion injury.IRI involves a complex interplay between neutrophils,natural killer T-cells cells,CD4+ T cell subtypes,cytokines,nitric oxide synthases,haem oxygenase-1,survival kinases such as the signal transducer and activator of transcription,Phosphatidylinositol 3-kinases/Akt and nuclear factor κβ pathways.Transgenic animals,particularly genetic knockout models,have become a powerful tool at elucidating mechanisms of liver ischaemia reperfusion injury and are complementary to pharmacological studies.Targeted disruption of the protein at the genetic level is more specific and maintained than pharmacological inhibitors or stimulants of the same protein.This article reviews the evidence from knockout models of liver IRI about the cellular and molecular mechanisms underlying liver IRI.
文摘In this paper, we show that supercritical fluids have a greater significance in the generation of pegmatites,and for ore-forming processes related to granites than is usually assumed. We show that the supercritical melt or fluid is a silicate phase in which volatiles; principally H_2O are completely miscible in all proportions at magmatic temperatures and pressures. This phase evolves from felsic melts and changes into hydrothermal fluids, and its unique properties are particularly important in sequestering and concentrating low abundance elements, such as metals. In our past research, we have focused on processes observed at upper crustal levels, however extensive work by us and other researchers have demonstrated that supercritical melt/fluids should be abundant in melting zones at deep-crustal levels too. We propose that these fluids may provide a connecting link between lower and upper crustal magmas,and a highly efficient transport mechanism for usually melt incompatible elements. In this paper, we explore the unique features of this fluid which allow the partitioning of variouselements and compounds, potentially up to extreme levels,and may explain various features both of mineralization and the magmas that produced them.
文摘This review of new understanding and forecasting of tropical cyclones(TCs) is based on presentations at the International Top-level Forum on Rapid Change Phenomena in Tropical Cyclones in Haikou, China. The major topics are the sudden changes in tracks, rapid changes in structure and intensity, rapid changes in rainfall, and advances in forecasting and forecaster requirements. Although improved track forecast guidance has been achieved with the Australian ACCESS-TC model and in track forecasts to 120 h by the China Meteorological Administration, there is a continuing need for better understanding and improved track forecast guidance. Advances in understanding of processes related to rapid intensification(RI), secondary eyewall formation, mechanisms controlling inner-core structure and size changes, and structure and intensity changes at landfall have been achieved, but progress in prediction of rapid changes in structure and intensity has been slow. Taking into account complex interactions involved in TC-related rainfall, a prioritized list of physical processes that govern rainfall from landfalling TCs in China has been developed. While forecaster participants were generally encouraged by the progress being made, they expressed a strong desire for a transition of that new knowledge to timely and reliable forecast guidance products.
基金Project(51678576) supported by the National Natural Science Foundation of ChinaProject(2017YFB1201204) supported by the National Key R&D Program of China。
文摘This paper focuses on understanding and evaluating the dynamic effect of the heavy-haul train system on the seismic performance of a long-span railway bridge. A systematic study on the effect of heavy-haul trains on bridge seismic response has been conducted, considering the influence of vehicle modeling strategies and dynamic characteristics of the seismic waves. For this purpose, the performance of a long-span cable-stayed railway bridge is assessed with stationary trains atop it, where the heavy-haul vehicles are modeled in two different ways: the multi-rigid body model with suspension system and additional mass model. Comparison of the bridge response in the presence or absence of the train system has been conducted, and the vehicle loading situation, which includes full-load and no-load, is also discussed. The result shows that during the earthquake, the peak moment of the main girder and peak stress of stay cables increase by 80% and by 40% in the presence of fully loaded heavy-haul trains, respectively. At the same time, a considerable decrease appears in the peak acceleration of the main girder. This proves the existence of the damping effect of the heavy-haul train system, and this effect is more obvious for the fully loaded vehicles. Finally, this paper proposes an efficient vehicle modeling method with 2 degrees of freedom(DOF) for simplifying the treatment of the train system in bridge seismic checking.
文摘During liver resection surgery for cancer or liver transplantation,the liver is subject to ischaemia (reduction in blood flow) followed by reperfusion (restoration of blood flow),which results in liver injury [ischemiareperfusion (IR) or IR injury]. Modulation of IR injury can be achieved in various ways. These include hypothermia,ischaemic preconditioning (IPC) (brief cycles of ischaemia followed by reperfusion of the organ before the prolonged period of ischaemia i.e. a conditioning response),ischaemic postconditioning (conditioning after the prolonged period of ischaemia but before the reperfusion),pharmacological agents to decrease IR injury,genetic modulation of IR injury,and machine perfusion (pulsatile perfusion). Hypothermia decreases the metabolic functions and the oxygen consumption of organs. Static cold storage in University of Wisconsin solution reduces IR injury and has prolonged organ storage and improved the function of transplanted grafts. There is currently no evidence for any clinical advantage in the use of alternate solutions for static cold storage. Although experimental data from animal models suggest that IPC,ischaemic postconditioning,various pharma-cological agents,gene therapy,and machine perfusion decrease IR injury,none of these interventions can be recommended in clinical practice. This is because of the lack of randomized controlled trials assessing the safety and efficacy of ischaemic postconditioning,gene therapy,and machine perfusion. Randomized controlled trials and systematic reviews of randomized controlled trials assessing the safety and efficacy of IPC and various pharmacological agents have demonstrated biochemical or histological improvements but this has not translated to clinical benefit. Further well designed randomized controlled trials are necessary to assess the various new protective strategies in liver resection.
文摘We provide a review of our recent 100-Gb/s, high spectral efficiency （SE） experiment targeting transoceanic and regional undersea transmission distances. We demonstrated that simple pre-filtering at the transmitter together with a maximum a posteriori probability （MAP） detection algorithm can significantly improve SE. We transmitted 96×100-Gb/s pre-filtered polarization division multiplexed return-to-zero quadrature phase shift keyed （PDM-RZ-QPSK） channels with 300% SE over 10608 km using 52-km spans of 150-μm 2 fiber and simple single-stage erbium-doped fiber amplifiers （EDFAs）. We also achieved 400% SE over 4368 km using similar techniques.
基金Project supported by the Canadian International Development Agency, Canada and the Chinese Academy of Sciences. China (No.KZCX2-413).
文摘While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic consequences of non-point pollution in China or the policy options that could be employed to combat it. In this work a sustainable strategy to control non-point pollution from crop production, which involved taxing excessive inputs of irrigation water and fertilizer, was proposed. The approach taken to assess these measures combined biophysical and economic models,having a trade-off between economic returns and an improved environment. A proven and practical spatially referenced water and nutrient management model was used to determine the quantities of excessive irrigation water and fertilizer for specific soil and land use. Also, a set of indicators were proposed for evaluating the effects of agricultural economic output and agricultural practices on the environment.
文摘To investigate the additional clinical impact of hepatic ischaemia reperfusion injury (HIRI) on patients sustaining acute kidney injury (AKI) following liver transplantation. METHODSThis was a single-centre retrospective study of consecutive adult patients undergoing orthotopic liver transplantation (OLT) between January 2013 and June 2014. Early AKI was identified by measuring serum creatinine at 24 h post OLT (> 1.5 × baseline) or by the use of continuous veno-venous haemofiltration (CVVHF) during the early post-operative period. Patients with and without AKI were compared to identify risk factors associated with this complication. Peak serum aspartate aminotransferase (AST) within 24 h post-OLT was used as a surrogate marker for HIRI and severity was classified as minor (< 1000 IU/L), moderate (1000-5000 IU/L) or severe (> 5000 IU/L). The impact on time to extubation, intensive care length of stay, incidence of chronic renal failure and 90-d mortality were examined firstly for each of the two complications (AKI and HIRI) alone and then as a combined outcome. RESULTSOut of the 116 patients included in the study, 50% developed AKI, 24% required CVVHF and 70% sustained moderate or severe HIRI. Median peak AST levels were 1248 IU/L and 2059 IU/L in the No AKI and AKI groups respectively (P = 0.0003). Furthermore, peak serum AST was the only consistent predictor of AKI on multivariate analysis P = 0.02. AKI and HIRI were individually associated with a longer time to extubation, increased length of intensive care unit stay and reduced survival. However, the patients who sustained both AKI and moderate or severe HIRI had a longer median time to extubation (P < 0.001) and intensive care length of stay (P = 0.001) than those with either complication alone. Ninety-day survival in the group sustaining both AKI and moderate or severe HIRI was 89%, compared to 100% in the groups with either or neither complication (P = 0.049). CONCLUSIONHIRI has an important role in the development of AKI post-OLT and has a negative impac
基金Research Grants Council,University Grants Committee(GRF 11213618)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB24030300)。
文摘Passive all-optical signal processors that overcome the electronic bottleneck can potentially be the enabling components for the next-generation high-speed and lower power consumption systems. Here, we propose and experimentally demonstrate a CMOS-compatible waveguide and its application to the all-optical analog-to-digital converter(ADC) under the nonlinear spectral splitting and filtering scheme. As the key component of the proposed ADC, a 50 cm long high-index doped silica glass spiral waveguide is composed of a thin silicon-nanocrystal(Si-nc) layer embedded in the core center for enhanced nonlinearity. The device simultaneously possesses low loss(0.16 dB/cm at 1550 nm), large nonlinearity(305 W^-1∕km at 1550 nm), and negligible nonlinear absorption.A 2-bit ADC basic unit is achieved when pumped by the proposed waveguide structure at the telecom band and without any additional amplification. Simulation results that are consistent with the experimental ones are also demonstrated, which further confirm the feasibility of the proposed scheme for larger quantization resolution.This demonstrated approach enables a fully monolithic solution for all-optical ADC in the future, which can digitize broadband optical signals directly at low power consumption. This has great potential on the applications of high-speed optical communications, networks, and signal processing systems.
文摘Water samples were collected over P. ponchetii bloom period beginning in November 1988, in 15m water column, from 10km offshore of Davis Station, Vestfold Hill, Antarctica. The concentrations of acrylic acid and dimethyl sulphide (DMS), which are toxic compounds in the water samples, were determined by HPLC and GC. The result shows that the concentration of acrylic acid varies in 0. 001 - 0. 510μmol ?L-1 and the concentration of DMS in 0. 003-0. 588 μmol ?L-1 during P. pouchetii bloom. Both the increased since late December 1988 and reached the highest concentration in early January 1989, then they decreased rapidly and returned to lower level from middle January to February in agreement with variation in cell number of the unicell alga P. pouchetii. The correlation coefficients between acrylic acid and P. pouchetii and between DMS and P. pouchetii are all 0. 998. It is undoubted that P. pouchetii produced acrylic acid and DMS. The highest productivity of acrylic acid and DMS were 9. 76X 10-8 umol cell-1 and 13. 09 ×10-8 μmol ?cell-1, respectively, during P. pouchelii bloom. A cellular product, dimethylsulphonium propionate (DMSP), is decomposed into acrylic acid and DMS, and the formation of DMSP is probably from methionine which could be utilized by P. pouchelii.
基金S.T.Chu acknowledges support from the City University of Hong Kong(APRC Grant no.9610395)Y.Ou acknowledges support from the Fundamental Research Funds for the Central Universities(Grant No.2023RC50).
文摘Integrated switches play a crucial role in the development of reconfigurable optical add-drop multiplexers(ROADMs)that have greater flexibility and compactness,ultimately leading to robust single-chip solutions.Despite decades of research on switches with various structures and platforms,achieving a balance between dense integration,low insertion loss(IL),and polarization-dependent loss(PDL)remains a significant challenge.In this paper,we propose and demonstrate a 32×4 optical switch using high-index doped silica glass(HDSG)for ROADM applications.This switch is designed to route any of the 32 inputs to the express ports or drop any channels from 32 inputs to the target 4 drop ports or add any of the 4 ports to any of the 32 express channels.The switch comprises 188 MachZehnder Interferometer(MZI)type switch elements,88 optical vias for the 44 optical bridges,and 618 waveguidewaveguide crossings with three-dimensional(3D)structures.At 1550 nm,the fiber-to-fiber loss for each express channel is below 2 dB,and across the C and L bands,below 3 dB.For each input channel to all 4 drop/add channels at 1550 nm,the loss is less than 3.5 dB and less than 5 dB across the C and L bands.The PDLs for all express and input channels to the 4 drop/add channels are below 0.3 dB over the C band,and the crosstalk is under−50 dB for both the C and L bands.
基金Supported by Chief Scientist Office Scotland(under project ETM/32)
文摘AIM: To examine the incidence of hepatitis E(HepE) in individuals with acute liver injury severe enough to warrant treatment at a transplant unit.METHODS: Hepatitis E virus(HEV) is an emerging pathogen in developed countries causing severe illness, particularly in immunocompromised patients or those with underlying chronic liver disease. HepE infection isoften under diagnosed, as clinicians can be reluctant to test patients who have not travelled to regions traditionally considered hyperendemic for HepE. There are few data regarding the significance of HEV in patients with very severe acute liver injury in developed countries. Eighty patients with acute severe liver injury attending the Scottish Liver Transplant unit were tested for HEV and anti-HEV IgG and IgM. Severe acute liver injury was defined as a sudden deterioration in liver function confirmed by abnormal liver function tests and coagulopathy or presence of hepatic encephalopathy. Eighty percent of these patients were diagnosed with paracetomol overdose. No patients had a history of chronic or decompensated chronic liver disease at time of sampling. IgG positive samples were quantified against the World Health Organization anti-HEV IgG standard. Samples were screened for HEV viral RNA by quantitative reverse transcription polymerase chain reaction.RESULTS: Four cases of hepatitis E were identified. Three of the four cases were only diagnosed on retrospective testing and were initially erroneously ascribed to drug-induced liver injury and decompensated chronic liver disease, with the cause of the decompensation uncertain. One case was caused by HEV genotype 1 in a traveller returning from Asia, the other three were autochthonous and diagnosed on retrospective testing. In two of these cases(where RNA was detected) HEV was found to be genotype 3, the most prevalent genotype in developed countries. Three patients survived, two of whom had been misdiagnosed as having drug induced liver injury. The fourth patient died from sepsis and liver failure precipitated
