AIM To determine whether infection in patients with acute severe alcoholic hepatitis(AAH) treated with corticosteroids is associated with increased mortality.METHODS Consecutive patients with AAH were treated with ste...AIM To determine whether infection in patients with acute severe alcoholic hepatitis(AAH) treated with corticosteroids is associated with increased mortality.METHODS Consecutive patients with AAH were treated with steroids and recruited to the study. Clinically relevant infections(body temperature > 38 ℃ or < 36 ℃ for more than 4 h, ascitic neutrophil count > 0.25 ×109/L, consolidation on chest radiograph or clinically relevant positive microbiological culture of bodily fluid) were recorded prospectively. Clinical and laboratory parameters were recorded and survival at 90 d and 6 mo was determined. Univariate analysis of factors associated with 90-d mortality was performed and significant variables included in a multivariate analysis.RESULTS Seventy-two patients were included in the final analysis(mean age 47.9 years, 26% female, mean discriminant function 53.0). Overall mortality in the group occurred in 15(21%), 23(32%) and 31(43%) at day 28, day 90 and 1 year respectively. 36(50%) had a clinically relevant infection during their hospitalisation(23 after initiation of steroids). The median time to development of incident infection after commencement of steroids was 10 d. The commonest site of infection was ascites(31%) and bacteraemia(31%) followed by urinary tract(19%) and respiratory tract(8%). Forty-one separate organisms were isolated in 33 patients; the most frequent genus was Escherichia(22%) and Enterococcus(20%). Infection was not associated with 90-d or 1 year mortality but was associated with higher creatinine, model for end-stage liver disease and Lille score. Baseline urea was the only independent predictor of 90-d mortality.CONCLUSION Clinically relevant infections are common in patients with AAH but are not associated with increased 90-d or 1 year mortality.展开更多
Located at the southern boundary of the tropical rainfall belt within the South Africa monsoon regime,Rodrigues Island,~2500 km east of East Africa,is ideally located to investigate climatic changes over the southwest...Located at the southern boundary of the tropical rainfall belt within the South Africa monsoon regime,Rodrigues Island,~2500 km east of East Africa,is ideally located to investigate climatic changes over the southwest Indian Ocean(SWIO).In this study,we investigate the climatic controls of its modern interannual rainfall variability in terms of teleconnection and local effects.We find that increased rainfall over the SWIO tends to occur in association with anomalously warm(cold)SSTs over the equatorial central Pacific(Maritime Continent),resembling the central Pacific El Niño,closely linked with the Victoria mode in the North Pacific.Our analyses show that the low-level convergence induced by warm SST over the equatorial central Pacific leads to anomalous low-level divergence over the Maritime Continent and convergence over a large area surrounding the Rodrigues Island,which leads to increased rainfall over the SWIO during the rainy season.Meanwhile,the excited Rossby wave along the tropical Indian Ocean transports more water vapor from the tropical convergence zone into the SWIO via intensified northwest wind.Furthermore,positive feedback induced by the Rossby wave response to the increased rainfall in the region contributes to the large interannual variations over the SWIO.展开更多
The Asian summer monsoon(ASM) is a vast climate system, whose variability is critical to the livelihoods of billions of people across the Asian continent. During the past half-century, much progress has been made in u...The Asian summer monsoon(ASM) is a vast climate system, whose variability is critical to the livelihoods of billions of people across the Asian continent. During the past half-century, much progress has been made in understanding variations on a wide range of timescales, yet several significant issues remain unresolved. Of note are two long-standing problems concerning orbital-scale variations of the ASM.(1) Chinese loess magnetic susceptibility records show a persistent glacial-interglacial dominated ~100 kyr(thousand years) periodicity, while the cave oxygen-isotope(δ18 O) records reveal periodicity in an almost pure precession band(~20 kyr periodicity)—the "Chinese 100 kyr problem".(2) ASM records from the Arabian Sea and other oceans surrounding the Asian continent show a significant lag of 8–10 kyr to Northern Hemisphere summer insolation(NHSI), whereas the Asian cave δ18 O records follow NHSI without a significant lag—a discrepancy termed the "sea-land precession-phase paradox". How can we reconcile these differences? Recent and more refined model simulations now provide spatial patterns of rainfall and wind across the precession cycle, revealing distinct regional divergences in the ASM domain, which can well explain a large portion of the disparities between the loess, marine, and cave proxy records. Overall, we also find that the loess, marine, and cave records are indeed complementary rather than incompatible, with each record preferentially describing a certain aspect of ASM dynamics. Our study provides new insight into the understanding of different hydroclimatic proxies and largely reconciles the "Chinese 100 kyr problem" and "sea-land precession-phase paradox".展开更多
Instrumental observations from many tropical and monsoonal regions,particularly from some of the most densely populated locations in Indo-Pacific and the maritime continent,are revealing a rather worrisome trend.Tropi...Instrumental observations from many tropical and monsoonal regions,particularly from some of the most densely populated locations in Indo-Pacific and the maritime continent,are revealing a rather worrisome trend.Tropical rainfall appears to be declining since the middle of the 20th century(Fig.1).Identifying the primary drivers of this drying trend is crucial to assess whether it stems from anthropogenic forcing and thus,expected to continue or merely a manifestation of multi-decadal or longer-term natural climate variability.Writing in Proc Natl Acad Sci USA,Tan et al.[1]show that the decades-long drying trend in the north central IndoPacific(NCIP)region is not unique in the context of the region’s hydroclimate variability during the last two to three millennia;and in fact,the study indicates that NCIP was struck by previous episodes of drier condition,rivaling that of the current drying trend.This study further underscores the classic detection and attribution problem faced by climate scientists today in parsing the relative influence of anthropogenic forced changes in rainfall from natural variability[2].展开更多
The widely accepted“Milankovitch theory”explains insolation-induced waxing and waning of the ice sheets and their effect on the global climate on orbital timescales.In the past half century,however,the theory has of...The widely accepted“Milankovitch theory”explains insolation-induced waxing and waning of the ice sheets and their effect on the global climate on orbital timescales.In the past half century,however,the theory has often come under scrutiny,especially regarding its“100-ka problem.”Another drawback,but the one that has received less attention,is the“monsoon problem,”which pertains to the exclusion of monsoon dynamics in classic Milankovitch theory even though the monsoon prevails over the vast low-latitude(30N to30S)region that covers half of the Earth’s surface and receives the bulk of solar radiation.In this review,we discuss the major issues with the current form of Milankovitch theory and the progress made at the research forefront.展开更多
文摘AIM To determine whether infection in patients with acute severe alcoholic hepatitis(AAH) treated with corticosteroids is associated with increased mortality.METHODS Consecutive patients with AAH were treated with steroids and recruited to the study. Clinically relevant infections(body temperature > 38 ℃ or < 36 ℃ for more than 4 h, ascitic neutrophil count > 0.25 ×109/L, consolidation on chest radiograph or clinically relevant positive microbiological culture of bodily fluid) were recorded prospectively. Clinical and laboratory parameters were recorded and survival at 90 d and 6 mo was determined. Univariate analysis of factors associated with 90-d mortality was performed and significant variables included in a multivariate analysis.RESULTS Seventy-two patients were included in the final analysis(mean age 47.9 years, 26% female, mean discriminant function 53.0). Overall mortality in the group occurred in 15(21%), 23(32%) and 31(43%) at day 28, day 90 and 1 year respectively. 36(50%) had a clinically relevant infection during their hospitalisation(23 after initiation of steroids). The median time to development of incident infection after commencement of steroids was 10 d. The commonest site of infection was ascites(31%) and bacteraemia(31%) followed by urinary tract(19%) and respiratory tract(8%). Forty-one separate organisms were isolated in 33 patients; the most frequent genus was Escherichia(22%) and Enterococcus(20%). Infection was not associated with 90-d or 1 year mortality but was associated with higher creatinine, model for end-stage liver disease and Lille score. Baseline urea was the only independent predictor of 90-d mortality.CONCLUSION Clinically relevant infections are common in patients with AAH but are not associated with increased 90-d or 1 year mortality.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.41888101,41731174 and 41561144003 to Hai CHENG,and 41472140)the Chinese Academy of Sciences“PIFI Program”(Grant No.2020VCA0019)to Ashish SINHA.Qiong ZHANG acknowledges the support from Swedish Research Council(Vetenskapsrådet,Grant Nos.2013-06476 and 2017-04232).
文摘Located at the southern boundary of the tropical rainfall belt within the South Africa monsoon regime,Rodrigues Island,~2500 km east of East Africa,is ideally located to investigate climatic changes over the southwest Indian Ocean(SWIO).In this study,we investigate the climatic controls of its modern interannual rainfall variability in terms of teleconnection and local effects.We find that increased rainfall over the SWIO tends to occur in association with anomalously warm(cold)SSTs over the equatorial central Pacific(Maritime Continent),resembling the central Pacific El Niño,closely linked with the Victoria mode in the North Pacific.Our analyses show that the low-level convergence induced by warm SST over the equatorial central Pacific leads to anomalous low-level divergence over the Maritime Continent and convergence over a large area surrounding the Rodrigues Island,which leads to increased rainfall over the SWIO during the rainy season.Meanwhile,the excited Rossby wave along the tropical Indian Ocean transports more water vapor from the tropical convergence zone into the SWIO via intensified northwest wind.Furthermore,positive feedback induced by the Rossby wave response to the increased rainfall in the region contributes to the large interannual variations over the SWIO.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41888101 & 41731174)。
文摘The Asian summer monsoon(ASM) is a vast climate system, whose variability is critical to the livelihoods of billions of people across the Asian continent. During the past half-century, much progress has been made in understanding variations on a wide range of timescales, yet several significant issues remain unresolved. Of note are two long-standing problems concerning orbital-scale variations of the ASM.(1) Chinese loess magnetic susceptibility records show a persistent glacial-interglacial dominated ~100 kyr(thousand years) periodicity, while the cave oxygen-isotope(δ18 O) records reveal periodicity in an almost pure precession band(~20 kyr periodicity)—the "Chinese 100 kyr problem".(2) ASM records from the Arabian Sea and other oceans surrounding the Asian continent show a significant lag of 8–10 kyr to Northern Hemisphere summer insolation(NHSI), whereas the Asian cave δ18 O records follow NHSI without a significant lag—a discrepancy termed the "sea-land precession-phase paradox". How can we reconcile these differences? Recent and more refined model simulations now provide spatial patterns of rainfall and wind across the precession cycle, revealing distinct regional divergences in the ASM domain, which can well explain a large portion of the disparities between the loess, marine, and cave proxy records. Overall, we also find that the loess, marine, and cave records are indeed complementary rather than incompatible, with each record preferentially describing a certain aspect of ASM dynamics. Our study provides new insight into the understanding of different hydroclimatic proxies and largely reconciles the "Chinese 100 kyr problem" and "sea-land precession-phase paradox".
文摘Instrumental observations from many tropical and monsoonal regions,particularly from some of the most densely populated locations in Indo-Pacific and the maritime continent,are revealing a rather worrisome trend.Tropical rainfall appears to be declining since the middle of the 20th century(Fig.1).Identifying the primary drivers of this drying trend is crucial to assess whether it stems from anthropogenic forcing and thus,expected to continue or merely a manifestation of multi-decadal or longer-term natural climate variability.Writing in Proc Natl Acad Sci USA,Tan et al.[1]show that the decades-long drying trend in the north central IndoPacific(NCIP)region is not unique in the context of the region’s hydroclimate variability during the last two to three millennia;and in fact,the study indicates that NCIP was struck by previous episodes of drier condition,rivaling that of the current drying trend.This study further underscores the classic detection and attribution problem faced by climate scientists today in parsing the relative influence of anthropogenic forced changes in rainfall from natural variability[2].
基金supported by the NationalNatural Science Foundation ofChina(41888101 and 42150710534).
文摘The widely accepted“Milankovitch theory”explains insolation-induced waxing and waning of the ice sheets and their effect on the global climate on orbital timescales.In the past half century,however,the theory has often come under scrutiny,especially regarding its“100-ka problem.”Another drawback,but the one that has received less attention,is the“monsoon problem,”which pertains to the exclusion of monsoon dynamics in classic Milankovitch theory even though the monsoon prevails over the vast low-latitude(30N to30S)region that covers half of the Earth’s surface and receives the bulk of solar radiation.In this review,we discuss the major issues with the current form of Milankovitch theory and the progress made at the research forefront.
