Objective To assess the secular trends in the etiology and comorbidity ofpatients hospitalized with congestive heart failure (CHF).Methods Data of 7,319 patients (mean age 59.6 years, 62.1% male) with a primary discha...Objective To assess the secular trends in the etiology and comorbidity ofpatients hospitalized with congestive heart failure (CHF).Methods Data of 7,319 patients (mean age 59.6 years, 62.1% male) with a primary discharge diagnosis of CHF, hospitalized from January 1, 1993 to December 31, 2007 at the Chinese People’s Liberation Army (PLA) General Hospital were extracted and analyzed. These patients were divided into three groups according to hospitalization period: 1993–1997 (n = 1623), 1998–2002 (n = 2444), and 2003–2007 (n = 3252). The etiological characteristics and comorbidities were assessed. Results Over the study period, the proportion of patients with ischemic heart disease (IHD) increased from 37.2% during the period 1993–1997 to 46.8% during the period 2003–2007, while that with valvular heart disease (VHD) decreased from 35.2%during the period 1993–1997 to 16.6% during the period 2003–2007 (both P < 0.05). Atrial fibrillation (AF) was the most common comorbidity of heart failure (23.2%, 23.0% and 20.6%, respectively, in the three periods). Compared to that of the period of 1993–1997 with that of, the proportion of patients with myocardial infarction, pneumonia, renal function impairment and hepatic cirrhosis of the period of 2003–2007 increased significantly (P < 0.05) and the proportion of patients with chronic obstructive pulmonary disease and atrial fibrillation decreased significantly (P < 0.05). Conclusions This study implies that IHD has became a more common etiology of CHF, while VHD has deceased as an etiology of CHF in Chinese patients during the last two decades.展开更多
Carbon fluxes were measured using a static chamber technique in an alpine steppe in the Qinghai-Tibet Plateau from July 2000 to July 2001. It was shown that carbon emissions decreased in autumn and increased in spring...Carbon fluxes were measured using a static chamber technique in an alpine steppe in the Qinghai-Tibet Plateau from July 2000 to July 2001. It was shown that carbon emissions decreased in autumn and increased in spring of the next year, with higher values in growth seasons than in winters. An exponential correlation （Ecarbon = 0.22（exp（0.09T） ＋ In（0.31P ＋ 1））, R^2 = 0.77, P 〈 0.001） was shown between carbon emissions and environmental factors such as temperature （T） and precipitation （P）. Using the daily temperature （T） and total precipitation （R）, annual carbon emission from soil to the atmosphere was estimated to be 79.6 g C/m^2, 46% of which was emitted by microbial respiration. Considering an average net primary production of 92.5 g C/m^2 per year within the 2 year experiment, alpine steppes can take up 55.9 g CO2-C/m^2 per year. This indicates that alpine steppes are a distinct carbon sink, although this carbon reservoir was quite small.展开更多
文摘Objective To assess the secular trends in the etiology and comorbidity ofpatients hospitalized with congestive heart failure (CHF).Methods Data of 7,319 patients (mean age 59.6 years, 62.1% male) with a primary discharge diagnosis of CHF, hospitalized from January 1, 1993 to December 31, 2007 at the Chinese People’s Liberation Army (PLA) General Hospital were extracted and analyzed. These patients were divided into three groups according to hospitalization period: 1993–1997 (n = 1623), 1998–2002 (n = 2444), and 2003–2007 (n = 3252). The etiological characteristics and comorbidities were assessed. Results Over the study period, the proportion of patients with ischemic heart disease (IHD) increased from 37.2% during the period 1993–1997 to 46.8% during the period 2003–2007, while that with valvular heart disease (VHD) decreased from 35.2%during the period 1993–1997 to 16.6% during the period 2003–2007 (both P < 0.05). Atrial fibrillation (AF) was the most common comorbidity of heart failure (23.2%, 23.0% and 20.6%, respectively, in the three periods). Compared to that of the period of 1993–1997 with that of, the proportion of patients with myocardial infarction, pneumonia, renal function impairment and hepatic cirrhosis of the period of 2003–2007 increased significantly (P < 0.05) and the proportion of patients with chronic obstructive pulmonary disease and atrial fibrillation decreased significantly (P < 0.05). Conclusions This study implies that IHD has became a more common etiology of CHF, while VHD has deceased as an etiology of CHF in Chinese patients during the last two decades.
基金Supported by the National Basic Research Program (2005CB422005)the Pre-studies Project of National Basic Research Program(2005CCA05500)
文摘Carbon fluxes were measured using a static chamber technique in an alpine steppe in the Qinghai-Tibet Plateau from July 2000 to July 2001. It was shown that carbon emissions decreased in autumn and increased in spring of the next year, with higher values in growth seasons than in winters. An exponential correlation （Ecarbon = 0.22（exp（0.09T） ＋ In（0.31P ＋ 1））, R^2 = 0.77, P 〈 0.001） was shown between carbon emissions and environmental factors such as temperature （T） and precipitation （P）. Using the daily temperature （T） and total precipitation （R）, annual carbon emission from soil to the atmosphere was estimated to be 79.6 g C/m^2, 46% of which was emitted by microbial respiration. Considering an average net primary production of 92.5 g C/m^2 per year within the 2 year experiment, alpine steppes can take up 55.9 g CO2-C/m^2 per year. This indicates that alpine steppes are a distinct carbon sink, although this carbon reservoir was quite small.
