BACKGROUND: Significant hemorrhage together with blood transfusion increases postoperative morbidity and mortality of hepatic resection. Hepatic vascular occlusion is effective in minimizing bleeding during hepatic pa...BACKGROUND: Significant hemorrhage together with blood transfusion increases postoperative morbidity and mortality of hepatic resection. Hepatic vascular occlusion is effective in minimizing bleeding during hepatic parenchymal transection. This article aimed to review the current role and status of various techniques of hepatic vascular occlusion during hepatic resection. DATA SOURCES: The relevant manuscripts were identified by searching MEDLINE, and PubMed for articles published between January 1980 and April 2010 using the keywords 'vascular control', 'vascular clamping', 'vascular exclusion' and 'hepatectomy'. Additional papers were identified by a manual search of the references from the key articles. RESULTS: One randomized controlled trial (RCT) and 5 RCTs showed intermittent Pringle maneuver and ischemic preconditioning followed by continuous Pringle maneuver were superior to continuous Pringle maneuver alone, respectively. Two RCTs compared the outcomes of hepatectomy with and without intermittent Pringle maneuver. One showed Pringle maneuver to be beneficial, while the other failed to show any benefit. One RCT showed that ischemic preconditioning had significantly less blood loss than using intermittent Pringle maneuver. Four RCTs evaluated the use of hemihepatic vascular occlusion. One RCT showed it had significantly less blood loss than Pringle maneuver, while the other 3 showed no significant difference. Only 1 RCT showed it had significantly less liver ischemic injury. No RCT had been carried out to assess segmental vascular occlusion. Two RCTs compared the outcomes of total hepatic vascular exclusion (THVE) and Pringle maneuver. One RCT showed THVE resulted in similar blood loss, but a higher postoperative complication. The other RCT showed less blood loss using THVE but the postoperative complication rate was similar. Both studies showed similar degree of liver ischemic injury. Only one RCT showed that selective hepatic vascular exclusion (SHVE) had less blood loss and liver ischemic injury than P展开更多
Grazing exclusion using fences is a key policy being applied by the Chinese government to rehabilitate degraded grasslands on the Tibetan Plateau(TP)and elsewhere.However,there is a limited understanding of the effect...Grazing exclusion using fences is a key policy being applied by the Chinese government to rehabilitate degraded grasslands on the Tibetan Plateau(TP)and elsewhere.However,there is a limited understanding of the effects of grazing exclusion on alpine ecosystem functions and services and its impacts on herders’livelihoods.Our meta-analyses and questionnaire-based surveys revealed that grazing exclusion with fences was effective in promoting aboveground vegetation growth for up to four years in degraded alpine meadows and for up to eight years in the alpine steppes of the TP.Longer-term fencing did not bring any ecological and economic benefits.We also found that fencing hindered wildlife movement,increased grazing pressure in unfenced areas,lowered the satisfaction of herders,and rendered substantial financial costs to both regional and national governments.We recommend that traditional free grazing should be encouraged if applicable,short-term fencing(for 4-8 years)should be adopted in severely degraded grasslands,and fencing should be avoided in key wildlife habitat areas,especially the protected large mammal species.展开更多
Many studies have looked at connections between diet,etiology,signs and symptoms associated with inflammatory bowel disease(IBD).Although these connections are apparent to clinicians,they are difficult to prove qualit...Many studies have looked at connections between diet,etiology,signs and symptoms associated with inflammatory bowel disease(IBD).Although these connections are apparent to clinicians,they are difficult to prove qualitatively or quantitatively.Enteral feeding and polymeric diets are equally effective at bringing about remission in Crohn's disease(CD).Parenteral feeding is also effective,although none of these methods is as effective as corticosteroid therapy.However,enteral feeding is preferred in the pediatric population because linear growth is more adequately maintained via this route.Exclusion diets in patients brought into remission using an elemental diet have been shown to maintain remission for longer periods.Studies that aim to isolate culpable food groups have shown that individuals react differently on exposure to or exclusion of various foods.The commonly identifi ed food sensitivities are cereals,milk,eggs,vegetables and citrus fruits.Studies that have looked at gut mucosal antigen behavior have shown higher rectal blood flow,in response to specifi c food antigens,in those with CD over healthy subjects.Exclusion of sugar shows little evidence of amelioration in CD.Omega 3 fatty acids show promise in the treatment of IBD but await larger randomized controlled trials.Patients frequently notice that specifi c foods cause aggravation of their symptoms.Whilst it has been diffi cult to pinpoint specifi c foods,with advances in the laboratory tests and food supplements available,the aim is to prolong remission in these patients using dietary measures,and reduce the need for pharmacotherapy and surgical intervention.展开更多
Impacts of salinity become severe when the soil is deficient in oxygen. OxygaUon （using aerated water for subsurface drip irrigation of crop） could minimize the impact of salinity on plants under oxygen-limiting soi...Impacts of salinity become severe when the soil is deficient in oxygen. OxygaUon （using aerated water for subsurface drip irrigation of crop） could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation （12% air volume/volume of water） on vegetable soybean （moderately salt tolerant） and cotton （salt tolerant） in a salinized vertisol at 2, 8, 14, 20 dS/m ECe. In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency （WUE） by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na^＋ and CI^- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na^＋ or CI^- concentration. Oxygation invariably increased, whereas salinity reduced the K^＋： Na^＋ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.展开更多
China＇s Horqin Sandy Land,a formerly lush grassland,has experienced extensive desertification that caused considerable carbon（C） losses from the plant-soil system.Natural restoration through grazing exclusion is a ...China＇s Horqin Sandy Land,a formerly lush grassland,has experienced extensive desertification that caused considerable carbon（C） losses from the plant-soil system.Natural restoration through grazing exclusion is a widely suggested option to sequester C and to restore degraded land.In a desertified grassland,we investigated the C accumulation in the total and light fractions of the soil organic matter from 2005 to 2013 during natural restoration.To a depth of 20 cm,the light fraction organic carbon（LFOC） storage increased by 221 g C/m2（84%） and the total soil organic carbon（SOC） storage increased by 435 g C/m2（55%）.The light fraction dry matter content represented a small proportion of the total soil mass（ranging from 0.74% in 2005 to 1.39% in 2013）,but the proportion of total SOC storage accounted for by LFOC was remarkable（ranging from 33% to 40%）.The C sequestration averaged 28 g C/（m2·a） for LFOC and 54 g C/（m2·a） for total SOC.The total SOC was strongly and significantly positively linearly related to the light fraction dry matter content and the proportions of fine sand and silt＋clay.The light fraction organic matter played a major role in total SOC sequestration.Our results suggest that grazing exclusion can restore desertified grassland and has a high potential for sequestering SOC in the semiarid Horqin Sandy Land.展开更多
BACKGROUND: Hepatic resection is the main treatment modality for hepatic tumors. Advances in diagnostic technique, preoperative preparation, surgical technique, and postoperative management increased the success rate....BACKGROUND: Hepatic resection is the main treatment modality for hepatic tumors. Advances in diagnostic technique, preoperative preparation, surgical technique, and postoperative management increased the success rate. The present study aimed to evaluate hepatectomy and resection of inferior vena cava tumor thrombus (IVCTT) in patients with hepatocellular carcinoma, and the relationship between IVCTT classification and selection of surgical technique. METHODS: We retrospectively reviewed 13 patients with hepatocellular carcinoma who had undergone hepatectomy with IVCTT resection between May 1997 and August 2009. Age, gender, diagnosis, findings of physical examination, results of preoperative laboratory investigations, radiological examination, criteria for resection, postoperative pathological results, incisions, operative technique, intraoperative transfusion, drains, and intraoperative and postoperative complications were evaluated for all patients. RESULTS: Type Ⅰ IVCTT (10 patients) was posterior to the liver and below the diaphragm; type Ⅱ IVCTT (2 patients) was above the diaphragm but still outside the atrium; and type Ⅲ IVCTT (1 patient) was above the diaphragm and in the right atrium. Type Ⅰ was treated by radical hepatectomy and removal of IVCTT with total hepatic vascular exclusion. Type Ⅱ was treated by radical hepatectomy and removal of IVCTT by incision of the diaphragm. Type Ⅲ was treated by hepatectomy and resection of the thrombus from the right atrium under cardiopulmonary bypass. There were no surgical complications and one patient has been survived for 4 years with cancer-free status. The median survival time was 18.2 months, and the 1-and 2-year survival rates were 53.8% and 15.4%, respectively. CONCLUSION: Surgical treatment is safe and feasible for treatment of IVCTT in patients with hepatocellular carcinoma, and surgical resectability can be judged according to the classification of tumor thrombus.展开更多
Introduction Natural organic matter（NOM）present in source water has significant impact on water treatment processes and on the quality of drinking water.NOM is a complex mixture of diverse groups of organic compound...Introduction Natural organic matter（NOM）present in source water has significant impact on water treatment processes and on the quality of drinking water.NOM is a complex mixture of diverse groups of organic compounds,humic and fulvic acids,proteins,peptides,carbohydrates,and heterogeneous materials展开更多
文摘BACKGROUND: Significant hemorrhage together with blood transfusion increases postoperative morbidity and mortality of hepatic resection. Hepatic vascular occlusion is effective in minimizing bleeding during hepatic parenchymal transection. This article aimed to review the current role and status of various techniques of hepatic vascular occlusion during hepatic resection. DATA SOURCES: The relevant manuscripts were identified by searching MEDLINE, and PubMed for articles published between January 1980 and April 2010 using the keywords 'vascular control', 'vascular clamping', 'vascular exclusion' and 'hepatectomy'. Additional papers were identified by a manual search of the references from the key articles. RESULTS: One randomized controlled trial (RCT) and 5 RCTs showed intermittent Pringle maneuver and ischemic preconditioning followed by continuous Pringle maneuver were superior to continuous Pringle maneuver alone, respectively. Two RCTs compared the outcomes of hepatectomy with and without intermittent Pringle maneuver. One showed Pringle maneuver to be beneficial, while the other failed to show any benefit. One RCT showed that ischemic preconditioning had significantly less blood loss than using intermittent Pringle maneuver. Four RCTs evaluated the use of hemihepatic vascular occlusion. One RCT showed it had significantly less blood loss than Pringle maneuver, while the other 3 showed no significant difference. Only 1 RCT showed it had significantly less liver ischemic injury. No RCT had been carried out to assess segmental vascular occlusion. Two RCTs compared the outcomes of total hepatic vascular exclusion (THVE) and Pringle maneuver. One RCT showed THVE resulted in similar blood loss, but a higher postoperative complication. The other RCT showed less blood loss using THVE but the postoperative complication rate was similar. Both studies showed similar degree of liver ischemic injury. Only one RCT showed that selective hepatic vascular exclusion (SHVE) had less blood loss and liver ischemic injury than P
基金the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0405)the Science and Technology Service Network Initiative(KFJ-STS-QYZD060)+3 种基金the State Key Research Development Program of China(2016YFC0501802,2016YFC0501803 and 2016YFC0502002)the National Natural Science Foundation of China(41871040 and 41501057)the Innovative Research Team of the Ministry of Education of China(IRT_17R59)the Fundamental Research Funds for the Central Universities。
文摘Grazing exclusion using fences is a key policy being applied by the Chinese government to rehabilitate degraded grasslands on the Tibetan Plateau(TP)and elsewhere.However,there is a limited understanding of the effects of grazing exclusion on alpine ecosystem functions and services and its impacts on herders’livelihoods.Our meta-analyses and questionnaire-based surveys revealed that grazing exclusion with fences was effective in promoting aboveground vegetation growth for up to four years in degraded alpine meadows and for up to eight years in the alpine steppes of the TP.Longer-term fencing did not bring any ecological and economic benefits.We also found that fencing hindered wildlife movement,increased grazing pressure in unfenced areas,lowered the satisfaction of herders,and rendered substantial financial costs to both regional and national governments.We recommend that traditional free grazing should be encouraged if applicable,short-term fencing(for 4-8 years)should be adopted in severely degraded grasslands,and fencing should be avoided in key wildlife habitat areas,especially the protected large mammal species.
文摘Many studies have looked at connections between diet,etiology,signs and symptoms associated with inflammatory bowel disease(IBD).Although these connections are apparent to clinicians,they are difficult to prove qualitatively or quantitatively.Enteral feeding and polymeric diets are equally effective at bringing about remission in Crohn's disease(CD).Parenteral feeding is also effective,although none of these methods is as effective as corticosteroid therapy.However,enteral feeding is preferred in the pediatric population because linear growth is more adequately maintained via this route.Exclusion diets in patients brought into remission using an elemental diet have been shown to maintain remission for longer periods.Studies that aim to isolate culpable food groups have shown that individuals react differently on exposure to or exclusion of various foods.The commonly identifi ed food sensitivities are cereals,milk,eggs,vegetables and citrus fruits.Studies that have looked at gut mucosal antigen behavior have shown higher rectal blood flow,in response to specifi c food antigens,in those with CD over healthy subjects.Exclusion of sugar shows little evidence of amelioration in CD.Omega 3 fatty acids show promise in the treatment of IBD but await larger randomized controlled trials.Patients frequently notice that specifi c foods cause aggravation of their symptoms.Whilst it has been diffi cult to pinpoint specifi c foods,with advances in the laboratory tests and food supplements available,the aim is to prolong remission in these patients using dietary measures,and reduce the need for pharmacotherapy and surgical intervention.
基金funded by Central Queensland University Rockhampton,Australia
文摘Impacts of salinity become severe when the soil is deficient in oxygen. OxygaUon （using aerated water for subsurface drip irrigation of crop） could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation （12% air volume/volume of water） on vegetable soybean （moderately salt tolerant） and cotton （salt tolerant） in a salinized vertisol at 2, 8, 14, 20 dS/m ECe. In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency （WUE） by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na^＋ and CI^- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na^＋ or CI^- concentration. Oxygation invariably increased, whereas salinity reduced the K^＋： Na^＋ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.
基金supported by the National Natural Science Foundation of China (41271007,31170413)the National Science and Technology Support Program of China (2011BAC07B02)
文摘China＇s Horqin Sandy Land,a formerly lush grassland,has experienced extensive desertification that caused considerable carbon（C） losses from the plant-soil system.Natural restoration through grazing exclusion is a widely suggested option to sequester C and to restore degraded land.In a desertified grassland,we investigated the C accumulation in the total and light fractions of the soil organic matter from 2005 to 2013 during natural restoration.To a depth of 20 cm,the light fraction organic carbon（LFOC） storage increased by 221 g C/m2（84%） and the total soil organic carbon（SOC） storage increased by 435 g C/m2（55%）.The light fraction dry matter content represented a small proportion of the total soil mass（ranging from 0.74% in 2005 to 1.39% in 2013）,but the proportion of total SOC storage accounted for by LFOC was remarkable（ranging from 33% to 40%）.The C sequestration averaged 28 g C/（m2·a） for LFOC and 54 g C/（m2·a） for total SOC.The total SOC was strongly and significantly positively linearly related to the light fraction dry matter content and the proportions of fine sand and silt＋clay.The light fraction organic matter played a major role in total SOC sequestration.Our results suggest that grazing exclusion can restore desertified grassland and has a high potential for sequestering SOC in the semiarid Horqin Sandy Land.
基金supported by a grant from the Chinese Key Project for Infectious Diseases (2008ZX10002-025)
文摘BACKGROUND: Hepatic resection is the main treatment modality for hepatic tumors. Advances in diagnostic technique, preoperative preparation, surgical technique, and postoperative management increased the success rate. The present study aimed to evaluate hepatectomy and resection of inferior vena cava tumor thrombus (IVCTT) in patients with hepatocellular carcinoma, and the relationship between IVCTT classification and selection of surgical technique. METHODS: We retrospectively reviewed 13 patients with hepatocellular carcinoma who had undergone hepatectomy with IVCTT resection between May 1997 and August 2009. Age, gender, diagnosis, findings of physical examination, results of preoperative laboratory investigations, radiological examination, criteria for resection, postoperative pathological results, incisions, operative technique, intraoperative transfusion, drains, and intraoperative and postoperative complications were evaluated for all patients. RESULTS: Type Ⅰ IVCTT (10 patients) was posterior to the liver and below the diaphragm; type Ⅱ IVCTT (2 patients) was above the diaphragm but still outside the atrium; and type Ⅲ IVCTT (1 patient) was above the diaphragm and in the right atrium. Type Ⅰ was treated by radical hepatectomy and removal of IVCTT with total hepatic vascular exclusion. Type Ⅱ was treated by radical hepatectomy and removal of IVCTT by incision of the diaphragm. Type Ⅲ was treated by hepatectomy and resection of the thrombus from the right atrium under cardiopulmonary bypass. There were no surgical complications and one patient has been survived for 4 years with cancer-free status. The median survival time was 18.2 months, and the 1-and 2-year survival rates were 53.8% and 15.4%, respectively. CONCLUSION: Surgical treatment is safe and feasible for treatment of IVCTT in patients with hepatocellular carcinoma, and surgical resectability can be judged according to the classification of tumor thrombus.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)the National Natural Science Foundation of China,Alberta Innovates,and Alberta Health
文摘Introduction Natural organic matter（NOM）present in source water has significant impact on water treatment processes and on the quality of drinking water.NOM is a complex mixture of diverse groups of organic compounds,humic and fulvic acids,proteins,peptides,carbohydrates,and heterogeneous materials
