The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner M...The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner Mongolia Plateau. The research work was based on a 12-year study (from 1984 to 1995) of species abundance, diversity, and primary productivity of four Stipa communities, i.e. S. baicalensis Roshev., S. grandis P. Smirn., S, krylovii Roshev., and S. klemenzii Roshev. respectively. The Shnnon-Wiener index was used as a measurement of plant diversity, while functional composition was used to differentiate the functional groups that were included in the communities. The plant species of four Stipa communities were classified into functional groups based on the differences in life forms and ecological groups, which influence their performance in resource requirements, seasonality of growth, tolerance to water stress, and life history. Plant species were classified into five functional groups based on their differences in life form, shrubs and half shrubs, perennial bunch grasses, perennial rhizome grasses, forbs, annuals and biennials. Based on their differences in water requirement these species were classified into four functional groups: xerads, intermediate xerads, intermediate mesophytes, and mesophytes. The results showed: 1) Plant species diversity stabilized ecosystem processes. Shannon-Wiener index were 2.401 4, 2.172 0, 1.624 8, 0.354 3 from S. baicalensis community to S. grandis, S. krylovii and S. klemenzii community, respectively. The dynamics of the aboveground net primary productivity (ANPP) for a 12-year's period showed a reverse pattern, the coefficients of variation of the four communities were 21.94%, 20.63%, 29.21% and 39.72% respectively. 2) The Life form functional group component of diversity was a greater determinant of the ecosystem processes than the species component of diversity. The effects of perennial bunch grasses, perennial rhizome grasses and forbs on community stability w展开更多
Background： Common bile duct （CBD） stones may occur in up to 3%–14.7% of all patients with cholecystectomy.Various approaches of laparoscopic CBD exploration plus primary duct closure （PDC） are the most commonly...Background： Common bile duct （CBD） stones may occur in up to 3%–14.7% of all patients with cholecystectomy.Various approaches of laparoscopic CBD exploration plus primary duct closure （PDC） are the most commonly used and the best methods to treat CBD stone. This systematic review was to comparethe effectiveness and safety of the various approaches of laparoscopic CBD exploration plus PDC forcholedocholithiasis展开更多
Background： Chronic kidney disease has become a leading public health concern in China, as it is associated with increased morbidity, mortality, and costs. However, the overall situation regarding common glomerular d...Background： Chronic kidney disease has become a leading public health concern in China, as it is associated with increased morbidity, mortality, and costs. However, the overall situation regarding common glomerular diseases in China remains unclear. Hence, the aim of this study was to assess the national profile of the common types ofglomerulonephritis in China. Methods： We searched Medline, Embase, Cochrane Library, CNKI, SinoMed, VIP, and Wanfang databases for English and Chinese language articles from inception to September 2017. We also collected potentially relevant studies and reviews using a manual search. The fbllowing words in combinations are as keywords： ＂renal biopsy＂, ＂kidney pathological diagnosis＂, and ＂spectrum of pathological types＂. Results： We identified 23 studies involving 176,355 patients from 15 provinces/cities in China. The detection rates of primary glomerulonephritis （PGN） and secondary glomerulonephritis （SGN） were 0.740 and 0.221, respectively. Over the past 30 years, the top five types of PGN were immunoglobulin A nephropathy （IgAN; 24.3%）, mesangial proliferative glomerulonephritis （MsPGN; 10.5%）, membranous nephropathy （MN; 12.6%）, minimal change disease （MCD; 9.8%）, and tbcal segmental glomerulosclerosis （FSGS; 4.6%）, and the top four types of SGN were lupus nephritis （LN; 8.6%）, Henoch-Sch6nlein purpura glomerulonephritis （4.1%）, hepatitis B virus-associated glomerulonephritis （HBV-GN; 2.6%）, and diabetic nephropathy （DN; 1.6%）. The proportion of MN, MCD, HBV-GN, and DN tended to increase, while those of IgAN, MsPGN, FSGS, and LN tended to drop. Conclusions： Although the incidence of SGN is increasing gradually, PGN is still the leading lbrm of kidney disease in patients undergoing renal biopsies in China. IgAN and LN are the most common types of PGN and SGN, respectively. Differences between regions are related to various factors such as nationality, environment, and diet. Furthermore, unified standards and norms 展开更多
Variceal bleeding is a life-threatening complication of portal hypertension with a six-week mortality rate of approximately 20%. Patients with medium- or largesized varices can be treated for primary prophylaxis of va...Variceal bleeding is a life-threatening complication of portal hypertension with a six-week mortality rate of approximately 20%. Patients with medium- or largesized varices can be treated for primary prophylaxis of variceal bleeding using two strategies: non-selective beta-blockers(NSBBs) or endoscopic variceal ligation(EVL). Both treatments are equally effective. Patients with acute variceal bleeding are critically ill patients. The available data suggest that vasoactive drugs, combined with endoscopic therapy and antibiotics, are the best treatment strategy with EVL being the endoscopic procedure of choice. In cases of uncontrolled bleeding, transjugular intrahepatic portosystemic shunt(TIPS) with polytetrafluoroethylene(PTFE)-covered stents are recommended. Approximately 60% of the patients experience rebleeding, with a mortality rate of 30%. Secondary prophylaxis should start on day six following the initial bleeding episode. The combination of NSBBs and EVL is the recommended management, whereas TIPS with PTFE-covered stents are the preferred option in patients who fail endoscopic and pharmacologic treatment. Apart from injection sclerotherapy and EVL, other endoscopic procedures, including tissue adhesives, endoloops, endoscopic clipping and argon plasma coagulation, have been used in the management of esophageal varices. However, their efficacy and safety, compared to standard endoscopic treatment, remain to be further elucidated. There are safety issues accompanying endoscopic techniques with aspiration pneumonia occurring at a rate of approximately 2.5%. In conclusion, future research is needed to improve treatment strategies, including novel endoscopic techniques with better efficacy, lower cost, and fewer adverse events.展开更多
Background We developed a new combined strategy of thrombus aspiration plus intra-infarct-related artery （IRA） bolus administration of tirofiban via the aspiration catheter in patients with ST-segment elevation myoc...Background We developed a new combined strategy of thrombus aspiration plus intra-infarct-related artery （IRA） bolus administration of tirofiban via the aspiration catheter in patients with ST-segment elevation myocardial infarction （STEMI）. This strategy can reduce the distal embolism and achieve highly localized concentrations of tirofiban, which can improve myocardial reperfusion without increasing the risk of bleeding. The aim of this study was to investigate whether this combined strategy is superior to thrombus aspiration alone in improving myocardial perfusion in patients with STEMI undergoing primary angioplasty.Results Baseline characteristics of the two groups were well-balanced. The TIMI 3 flow showed a better tendency in the intra-IRA group than in the aspiration alone group （97.22% vs. 87.04%, X2=7.863, P=0.049）. The peak of CK-MB （83.9 （68.9-310.5） U/L vs. 126.1 （74.7-356.7） U/L, P=0.034） and Tnl （42.7 （14.7-113.9） ng/ml vs. 72.5 （59.8-135.3） ng/ml, FMD.029） were lower in the intra-IRA group than in the aspiration alone group. LVEF in the hospital favored the intra-IRA group, （45.7±8.3）% to （42.9±12.1）%, t=1.98, P=0.049. There was a tendency towards a lower MACE at 9-month follow-up in the intra-IRA group although it did not reach statistical difference （Log-rank X2=2.865, P=0.09）. There was no statistical difference in any bleeding events between the two groups.Conclusions Thrombus aspiration plus intra-IRA bolus administration of tirofiban combined with angioplasty may be related with improved myocardium perfusion, saved more myocardium, and resulted in a better clinical prognosis.展开更多
Among the many approaches for studying the net primary productivity (NPP), a new method by using remote sensing was introduced in this paper. With spectral information source (the visible band, near infrared band and ...Among the many approaches for studying the net primary productivity (NPP), a new method by using remote sensing was introduced in this paper. With spectral information source (the visible band, near infrared band and thermal infrared band) of NOAA-AVHRR, we can get the relative index and parameters, which can be used for estimating NPP of terrestrial vegetation. By means of remote sensing, the estimation of biomass and NPP is mainly based on the models of light energy utilization. In other words, the biomass and NPP can be calculated from the relation among NPP, absorbed photosynthetical active radiation (APAR) and the rate (epsilon) of transformation of APAR to organic matter, thus: NPP = ( FPAR x PAR) x [epsilon * x sigma (T) x sigma (E) x sigma (S) x (1 - Y-m) x (1 - Y-g)]. Based upon remote sensing ( RS) and geographic information system (GIS), the NPP of terrestrial vegetation in China in every ten days was calculated, and the annual NPP was integrated. The result showed that the total NPP of terrestrial vegetation in China was 6.13 x 10(9) t C . a(-1) in 1990 and the maximum NPP was 1 812.9 g C/m(2). According to this result, the spatio-temporal distribution of NPP was analyzed. Comparing to the statistical models, the RS model, using area object other than point one, can better reflect the distribution of NPP, and match the geographic distribution of vegetation in China.展开更多
Based on the GIMMS AVHRR NDVI data （8 km spatial resolution） for 1982-2000, the SPOT VEGETATION NDVI data （1 km spatial resolution） for 1998-2009, and observa- tional plant biomass data, the CASA model was used to...Based on the GIMMS AVHRR NDVI data （8 km spatial resolution） for 1982-2000, the SPOT VEGETATION NDVI data （1 km spatial resolution） for 1998-2009, and observa- tional plant biomass data, the CASA model was used to model changes in alpine grassland net primary production （NPP） on the Tibetan Plateau （TP）. This study will help to evaluate the health conditions of the alpine grassland ecosystem, and is of great importance to the pro- motion of sustainable development of plateau pasture and to the understanding of the func- tion of the national ecological security shelter on the TP. The spatio-temporal characteristics of NPP change were investigated using spatial statistical analysis, separately on the basis of physico-geographical factors （natural zone, altitude, latitude and longitude）, river basin, and county-level administrative area. Data processing was carried out using an ENVI 4.8 platform, while an ArcGIS 9.3 and ANUSPLIN platform was used to conduct the spatial analysis and mapping. The primary results are as follows： （1） The NPP of alpine grassland on the TP gradually decreases from the southeast to the northwest, which corresponds to gradients in precipitation and temperature. From 1982 to 2009, the average annual total NPP in the TP alpine grassland was 177.2x1012 gC yrl（yr represents year）, while the average annual NPP was 120.8 gC m^-2 yr^-1. （2） The annual NPP in alpine grassland on the TP fluctuates from year to year but shows an overall positive trend ranging from 114.7 gC m^-2 yr^-1 in 1982 to 129.9 gC m^-2 yr^-1 in 2009, with an overall increase of 13.3%; 32.56% of the total alpine grassland on the TP showed a significant increase in NPP, while only 5.55% showed a significant decrease over this 28-year period. （3） Spatio-temporal characteristics are an important control on an- nual NPP in alpine grassland： a） NPP increased in most of the natural zones on the TP, only showing a slight decrease in the Ngari montane desert-steppe and desert zone. The positive 展开更多
Background This study evaluated the clinical application of CT guided ^125iodine implantation in patients with portal vein tumor thrombus in primary hepatocellular carcinoma. Methods The ten patients （9 males and 1 f...Background This study evaluated the clinical application of CT guided ^125iodine implantation in patients with portal vein tumor thrombus in primary hepatocellular carcinoma. Methods The ten patients （9 males and 1 female, aged from 36 to 72 years） with portal vein tumor thrombus accompanying hepatocellular carcinoma had been treated with comprehensive therapy including surgery, transcatheter arterial chemoembolization, radiotherapy ablation, microwave ablation or percutaneous ethanol injection. The average diameter of each tumor thrombus was 21.5 mm × 30.5 mm. Seeds of 30 MBq ^125I were implanted 5 mm apart within the portal vein tumor thrombus. The follow-up after 4 months included enhanced spiral CT. Results CT screening of the tumours indicated that 4 out of 10 patients showed complete response to the therapy, 5 partial response and 1 stable disease. Adverse effects included aggravated abdominal dropsy and temporarily increased transaminase, which were controlled by medical management. Severe complications such as haemorrhage, biliary fistula hepatic abscess, pancreatic fistula and hepatic function failure were not observed. Implanted seeds migrated to lung and left hepatic lobe in 1 case. Conclusion CT guided implantation of ^125iodine seeds, can effectively treat portal vein tumor thrombus accompanying hepatocellular carcinoma with minimal damage and few complications.展开更多
The aromatic amino acids phenylalanine, tyrosine, and tryptophan in plants are not only essential components of protein synthesis, but also serve as precursors for a wide range of secondary metabolites that are import...The aromatic amino acids phenylalanine, tyrosine, and tryptophan in plants are not only essential components of protein synthesis, but also serve as precursors for a wide range of secondary metabolites that are important for plant growth as well as for human nutrition and health. The aromatic amino acids are synthesized via the shikimate pathway followed by the branched aromatic amino acids biosynthesis pathway, with chorismate serving as a major intermediate branch point metabolite. Yet, the regulation and coordination of synthesis of these amino acids are still far from being understood. Recent studies on these pathways identified a number of alternative cross-regulated biosynthesis routes with unique evolutionary origins. Although the major route of Phe and Tyr biosynthesis in plants occurs via the intermediate metabolite arogenate, recent studies suggest that plants can also synthesize phenylalanine via the intermediate metabolite phenylpyruvate （PPY）, similarly to many microorganisms. Recent studies also identified a number of transcription factors regulating the expression of genes encoding enzymes of the shikimate and aromatic amino acids pathways as well as of multiple secondary metabolites derived from them in Arabidopsis and in other plant species. .展开更多
The three major immune disorders of the liver are autoimmune hepatitis(AIH),primary biliary cirrhosis(PBC) and primary sclerosing cholangitis(PSC).Variant forms of these diseases are generally called overlap syndromes...The three major immune disorders of the liver are autoimmune hepatitis(AIH),primary biliary cirrhosis(PBC) and primary sclerosing cholangitis(PSC).Variant forms of these diseases are generally called overlap syndromes,although there has been no standardised definition.Patients with overlap syndromes present with both hepatitic and cholestatic serum liver tests and have histological features of AIH and PBC or PSC.The AIH-PBC overlap syndrome is the most common form,affecting almost 10% of adults with AIH or PBC.Single cases of AIH and autoimmune cholangitis(AMA-negative PBC) overlap syndrome have also been reported.The AIH-PSC overlap syndrome is predominantly found in children,adolescents and young adults with AIH or PSC.Interestingly,transitions from one autoimmune to another have also been reported in a minority of patients,especially transitions from PBC to AIH-PBC overlap syndrome.Overlap syndromes show a progressive course towards liver cirrhosis and liver failure without treatment.Therapy for overlap syndromes is empiric,since controlled trials are not available in these rare disorders.Anticholestatic therapy with ursodeoxycholic acid is usually combined with immunosuppressive therapy with corticosteroids and/or azathioprine in both AIH-PBC and AIH-PSC overlap syndromes.In end-stage disease,liver transplantation is the treatment of choice.展开更多
文摘The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner Mongolia Plateau. The research work was based on a 12-year study (from 1984 to 1995) of species abundance, diversity, and primary productivity of four Stipa communities, i.e. S. baicalensis Roshev., S. grandis P. Smirn., S, krylovii Roshev., and S. klemenzii Roshev. respectively. The Shnnon-Wiener index was used as a measurement of plant diversity, while functional composition was used to differentiate the functional groups that were included in the communities. The plant species of four Stipa communities were classified into functional groups based on the differences in life forms and ecological groups, which influence their performance in resource requirements, seasonality of growth, tolerance to water stress, and life history. Plant species were classified into five functional groups based on their differences in life form, shrubs and half shrubs, perennial bunch grasses, perennial rhizome grasses, forbs, annuals and biennials. Based on their differences in water requirement these species were classified into four functional groups: xerads, intermediate xerads, intermediate mesophytes, and mesophytes. The results showed: 1) Plant species diversity stabilized ecosystem processes. Shannon-Wiener index were 2.401 4, 2.172 0, 1.624 8, 0.354 3 from S. baicalensis community to S. grandis, S. krylovii and S. klemenzii community, respectively. The dynamics of the aboveground net primary productivity (ANPP) for a 12-year's period showed a reverse pattern, the coefficients of variation of the four communities were 21.94%, 20.63%, 29.21% and 39.72% respectively. 2) The Life form functional group component of diversity was a greater determinant of the ecosystem processes than the species component of diversity. The effects of perennial bunch grasses, perennial rhizome grasses and forbs on community stability w
基金supported by a grant from the Research Program for Health Care of Lanzhou Science and Technology Bureau(No.2013-3-37)
文摘Background： Common bile duct （CBD） stones may occur in up to 3%–14.7% of all patients with cholecystectomy.Various approaches of laparoscopic CBD exploration plus primary duct closure （PDC） are the most commonly used and the best methods to treat CBD stone. This systematic review was to comparethe effectiveness and safety of the various approaches of laparoscopic CBD exploration plus PDC forcholedocholithiasis
文摘Background： Chronic kidney disease has become a leading public health concern in China, as it is associated with increased morbidity, mortality, and costs. However, the overall situation regarding common glomerular diseases in China remains unclear. Hence, the aim of this study was to assess the national profile of the common types ofglomerulonephritis in China. Methods： We searched Medline, Embase, Cochrane Library, CNKI, SinoMed, VIP, and Wanfang databases for English and Chinese language articles from inception to September 2017. We also collected potentially relevant studies and reviews using a manual search. The fbllowing words in combinations are as keywords： ＂renal biopsy＂, ＂kidney pathological diagnosis＂, and ＂spectrum of pathological types＂. Results： We identified 23 studies involving 176,355 patients from 15 provinces/cities in China. The detection rates of primary glomerulonephritis （PGN） and secondary glomerulonephritis （SGN） were 0.740 and 0.221, respectively. Over the past 30 years, the top five types of PGN were immunoglobulin A nephropathy （IgAN; 24.3%）, mesangial proliferative glomerulonephritis （MsPGN; 10.5%）, membranous nephropathy （MN; 12.6%）, minimal change disease （MCD; 9.8%）, and tbcal segmental glomerulosclerosis （FSGS; 4.6%）, and the top four types of SGN were lupus nephritis （LN; 8.6%）, Henoch-Sch6nlein purpura glomerulonephritis （4.1%）, hepatitis B virus-associated glomerulonephritis （HBV-GN; 2.6%）, and diabetic nephropathy （DN; 1.6%）. The proportion of MN, MCD, HBV-GN, and DN tended to increase, while those of IgAN, MsPGN, FSGS, and LN tended to drop. Conclusions： Although the incidence of SGN is increasing gradually, PGN is still the leading lbrm of kidney disease in patients undergoing renal biopsies in China. IgAN and LN are the most common types of PGN and SGN, respectively. Differences between regions are related to various factors such as nationality, environment, and diet. Furthermore, unified standards and norms
文摘Variceal bleeding is a life-threatening complication of portal hypertension with a six-week mortality rate of approximately 20%. Patients with medium- or largesized varices can be treated for primary prophylaxis of variceal bleeding using two strategies: non-selective beta-blockers(NSBBs) or endoscopic variceal ligation(EVL). Both treatments are equally effective. Patients with acute variceal bleeding are critically ill patients. The available data suggest that vasoactive drugs, combined with endoscopic therapy and antibiotics, are the best treatment strategy with EVL being the endoscopic procedure of choice. In cases of uncontrolled bleeding, transjugular intrahepatic portosystemic shunt(TIPS) with polytetrafluoroethylene(PTFE)-covered stents are recommended. Approximately 60% of the patients experience rebleeding, with a mortality rate of 30%. Secondary prophylaxis should start on day six following the initial bleeding episode. The combination of NSBBs and EVL is the recommended management, whereas TIPS with PTFE-covered stents are the preferred option in patients who fail endoscopic and pharmacologic treatment. Apart from injection sclerotherapy and EVL, other endoscopic procedures, including tissue adhesives, endoloops, endoscopic clipping and argon plasma coagulation, have been used in the management of esophageal varices. However, their efficacy and safety, compared to standard endoscopic treatment, remain to be further elucidated. There are safety issues accompanying endoscopic techniques with aspiration pneumonia occurring at a rate of approximately 2.5%. In conclusion, future research is needed to improve treatment strategies, including novel endoscopic techniques with better efficacy, lower cost, and fewer adverse events.
文摘Background We developed a new combined strategy of thrombus aspiration plus intra-infarct-related artery （IRA） bolus administration of tirofiban via the aspiration catheter in patients with ST-segment elevation myocardial infarction （STEMI）. This strategy can reduce the distal embolism and achieve highly localized concentrations of tirofiban, which can improve myocardial reperfusion without increasing the risk of bleeding. The aim of this study was to investigate whether this combined strategy is superior to thrombus aspiration alone in improving myocardial perfusion in patients with STEMI undergoing primary angioplasty.Results Baseline characteristics of the two groups were well-balanced. The TIMI 3 flow showed a better tendency in the intra-IRA group than in the aspiration alone group （97.22% vs. 87.04%, X2=7.863, P=0.049）. The peak of CK-MB （83.9 （68.9-310.5） U/L vs. 126.1 （74.7-356.7） U/L, P=0.034） and Tnl （42.7 （14.7-113.9） ng/ml vs. 72.5 （59.8-135.3） ng/ml, FMD.029） were lower in the intra-IRA group than in the aspiration alone group. LVEF in the hospital favored the intra-IRA group, （45.7±8.3）% to （42.9±12.1）%, t=1.98, P=0.049. There was a tendency towards a lower MACE at 9-month follow-up in the intra-IRA group although it did not reach statistical difference （Log-rank X2=2.865, P=0.09）. There was no statistical difference in any bleeding events between the two groups.Conclusions Thrombus aspiration plus intra-IRA bolus administration of tirofiban combined with angioplasty may be related with improved myocardium perfusion, saved more myocardium, and resulted in a better clinical prognosis.
文摘Among the many approaches for studying the net primary productivity (NPP), a new method by using remote sensing was introduced in this paper. With spectral information source (the visible band, near infrared band and thermal infrared band) of NOAA-AVHRR, we can get the relative index and parameters, which can be used for estimating NPP of terrestrial vegetation. By means of remote sensing, the estimation of biomass and NPP is mainly based on the models of light energy utilization. In other words, the biomass and NPP can be calculated from the relation among NPP, absorbed photosynthetical active radiation (APAR) and the rate (epsilon) of transformation of APAR to organic matter, thus: NPP = ( FPAR x PAR) x [epsilon * x sigma (T) x sigma (E) x sigma (S) x (1 - Y-m) x (1 - Y-g)]. Based upon remote sensing ( RS) and geographic information system (GIS), the NPP of terrestrial vegetation in China in every ten days was calculated, and the annual NPP was integrated. The result showed that the total NPP of terrestrial vegetation in China was 6.13 x 10(9) t C . a(-1) in 1990 and the maximum NPP was 1 812.9 g C/m(2). According to this result, the spatio-temporal distribution of NPP was analyzed. Comparing to the statistical models, the RS model, using area object other than point one, can better reflect the distribution of NPP, and match the geographic distribution of vegetation in China.
基金National Basic Research Program of China,No.2010CB951704Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDB03030501No.XDA05060704
文摘Based on the GIMMS AVHRR NDVI data （8 km spatial resolution） for 1982-2000, the SPOT VEGETATION NDVI data （1 km spatial resolution） for 1998-2009, and observa- tional plant biomass data, the CASA model was used to model changes in alpine grassland net primary production （NPP） on the Tibetan Plateau （TP）. This study will help to evaluate the health conditions of the alpine grassland ecosystem, and is of great importance to the pro- motion of sustainable development of plateau pasture and to the understanding of the func- tion of the national ecological security shelter on the TP. The spatio-temporal characteristics of NPP change were investigated using spatial statistical analysis, separately on the basis of physico-geographical factors （natural zone, altitude, latitude and longitude）, river basin, and county-level administrative area. Data processing was carried out using an ENVI 4.8 platform, while an ArcGIS 9.3 and ANUSPLIN platform was used to conduct the spatial analysis and mapping. The primary results are as follows： （1） The NPP of alpine grassland on the TP gradually decreases from the southeast to the northwest, which corresponds to gradients in precipitation and temperature. From 1982 to 2009, the average annual total NPP in the TP alpine grassland was 177.2x1012 gC yrl（yr represents year）, while the average annual NPP was 120.8 gC m^-2 yr^-1. （2） The annual NPP in alpine grassland on the TP fluctuates from year to year but shows an overall positive trend ranging from 114.7 gC m^-2 yr^-1 in 1982 to 129.9 gC m^-2 yr^-1 in 2009, with an overall increase of 13.3%; 32.56% of the total alpine grassland on the TP showed a significant increase in NPP, while only 5.55% showed a significant decrease over this 28-year period. （3） Spatio-temporal characteristics are an important control on an- nual NPP in alpine grassland： a） NPP increased in most of the natural zones on the TP, only showing a slight decrease in the Ngari montane desert-steppe and desert zone. The positive
文摘Background This study evaluated the clinical application of CT guided ^125iodine implantation in patients with portal vein tumor thrombus in primary hepatocellular carcinoma. Methods The ten patients （9 males and 1 female, aged from 36 to 72 years） with portal vein tumor thrombus accompanying hepatocellular carcinoma had been treated with comprehensive therapy including surgery, transcatheter arterial chemoembolization, radiotherapy ablation, microwave ablation or percutaneous ethanol injection. The average diameter of each tumor thrombus was 21.5 mm × 30.5 mm. Seeds of 30 MBq ^125I were implanted 5 mm apart within the portal vein tumor thrombus. The follow-up after 4 months included enhanced spiral CT. Results CT screening of the tumours indicated that 4 out of 10 patients showed complete response to the therapy, 5 partial response and 1 stable disease. Adverse effects included aggravated abdominal dropsy and temporarily increased transaminase, which were controlled by medical management. Severe complications such as haemorrhage, biliary fistula hepatic abscess, pancreatic fistula and hepatic function failure were not observed. Implanted seeds migrated to lung and left hepatic lobe in 1 case. Conclusion CT guided implantation of ^125iodine seeds, can effectively treat portal vein tumor thrombus accompanying hepatocellular carcinoma with minimal damage and few complications.
文摘The aromatic amino acids phenylalanine, tyrosine, and tryptophan in plants are not only essential components of protein synthesis, but also serve as precursors for a wide range of secondary metabolites that are important for plant growth as well as for human nutrition and health. The aromatic amino acids are synthesized via the shikimate pathway followed by the branched aromatic amino acids biosynthesis pathway, with chorismate serving as a major intermediate branch point metabolite. Yet, the regulation and coordination of synthesis of these amino acids are still far from being understood. Recent studies on these pathways identified a number of alternative cross-regulated biosynthesis routes with unique evolutionary origins. Although the major route of Phe and Tyr biosynthesis in plants occurs via the intermediate metabolite arogenate, recent studies suggest that plants can also synthesize phenylalanine via the intermediate metabolite phenylpyruvate （PPY）, similarly to many microorganisms. Recent studies also identified a number of transcription factors regulating the expression of genes encoding enzymes of the shikimate and aromatic amino acids pathways as well as of multiple secondary metabolites derived from them in Arabidopsis and in other plant species. .
文摘The three major immune disorders of the liver are autoimmune hepatitis(AIH),primary biliary cirrhosis(PBC) and primary sclerosing cholangitis(PSC).Variant forms of these diseases are generally called overlap syndromes,although there has been no standardised definition.Patients with overlap syndromes present with both hepatitic and cholestatic serum liver tests and have histological features of AIH and PBC or PSC.The AIH-PBC overlap syndrome is the most common form,affecting almost 10% of adults with AIH or PBC.Single cases of AIH and autoimmune cholangitis(AMA-negative PBC) overlap syndrome have also been reported.The AIH-PSC overlap syndrome is predominantly found in children,adolescents and young adults with AIH or PSC.Interestingly,transitions from one autoimmune to another have also been reported in a minority of patients,especially transitions from PBC to AIH-PBC overlap syndrome.Overlap syndromes show a progressive course towards liver cirrhosis and liver failure without treatment.Therapy for overlap syndromes is empiric,since controlled trials are not available in these rare disorders.Anticholestatic therapy with ursodeoxycholic acid is usually combined with immunosuppressive therapy with corticosteroids and/or azathioprine in both AIH-PBC and AIH-PSC overlap syndromes.In end-stage disease,liver transplantation is the treatment of choice.
