中国生态环境脆弱区范围界定

中国生态环境脆弱区既是生态退化区域, 也是贫困人口集中分布区, 但其空间分布范围至今仍然不明确。本研究针对土地沙化、水土流失和石漠化等典型生态问题, 采用遥感和GIS技术, 建立评价指标体系及评价模型, 综合评价了全国生态环境敏感性, 定量揭示敏感性空间分布特征。在此基础上, 结合政府文件和已有的研究成果, 识别出全国生态脆弱区分布范围。结果显示, 生态极敏感区主要分布在我国西北干旱/半干旱地区、西南湿润地区、东南湿润地区以及黄土高原丘陵沟壑区; 高度敏感区主要分布在阿尔泰山、天山、阴山南麓、科尔沁沙地、呼伦贝尔沙地、羌塘高原西部、横断山和东南丘陵山地等区域。在全国划定了18个重点生态脆弱区, 总面积240.1万km², 并明确了每个脆弱区的名称、类型、面积、分布范围以及面临的主要生态问题。完成的中国生态脆弱区分布图为全国生态保护红线划定提供了参考底图。     

水稻雄性不育恢复系明恢63的感光基因分析

水稻恢复系明恢63是中国应用面积最大、利用最广泛的恢复系。利用抽穗期感光性近等基因系EG0～EG7及ER～LR对明恢63进行的分析表明,明恢63在E1、E2、E3位点分别带有E1、e3、E3基因,在Se-1位点带无感光功能的Se-1^e基因。进一步用抽穗期QTL近等基因系NIL(Hd1)和NIL（Hd4)进行的研究表明,明恢63带有显性感光基因E1和无感光功能的Se-1^e基因,并推测明恢63带有能抑制E,基因表达的隐性抑制基因。认为籼型杂交稻抽穗期受不育系和恢复系感光基因及感光性抑制基因的共同作用。初步讨论了明恢63广适性的遗传基础。     

Use of Glucose,Insulin, and C‐Reactive Protein to Determine Need for Glucose Tolerance Testing

Objective: Glucose intolerance has been shown to be a better predictor of morbidity and mortality than impaired fasting glucose. However, glucose tolerance tests are inconvenient and expensive. This study evaluated the relative frequencies of glucose intolerance and impaired fasting glucose and sought to determine if 2‐hour glucose could be predicted from simple demographic and laboratory data in an obese population. Research Methods and Procedures: Eighty‐nine obese subjects (median BMI 35 kg/m², range 30 to 40 kg/m²) underwent glucose tolerance testing. Using step‐wise linear and logistic regression analysis, fasting glucose, high‐sensitivity C‐reactive protein (hsCRP), fasting insulin, high‐density lipoprotein cholesterol, triglycerides, weight, height, BMI, waist circumference, hip circumference, waist‐to‐hip ratio, sex, and age were assessed as predictors of glucose intolerance. Results: Impaired glucose tolerance was more prevalent (27%) than impaired fasting glucose (5.6%). Only fasting glucose and hsCRP were significant (p < 0.05) independent predictors of impaired 2‐hour glucose (>140 mg/dL). A fasting glucose ≥ 100 mg/dL or an hsCRP > 0.32 mg/dL (upper quartile of the normal range) detected 81% (sensitivity) of obese subjects with impaired glucose tolerance; however, specificity was poor (46%). Fasting insulin ≥ 6 μU/mL had better sensitivity (92%) but poorer specificity (30%). Discussion: Impaired glucose tolerance is more common than impaired fasting glucose in an obese population. Possible strategies to avoid doing glucose tolerance tests in all obese patients would be to do glucose tolerance testing only in those whose fasting glucose is ≥ 100 mg/dL or whose hsCRP exceeds 0.32 mg/dL or those whose fasting insulin is ≥ 6 μU/mL.     

Impaired Pressure Natriuresis in Obese Youths

Objective: To compare the response and recovery of blood pressure (BP) and sodium excretion (U_NaV) in response to a behavioral stressor in overweight/obese and lean adolescents. Research Methods and Procedures: Twenty‐five lean (12% to 20% body fat) and 59 overweight/obese (>25% body fat) normotensive adolescents were provided all meals for 3 days (average sodium intake, 4000 ± 200 mg/d), before performing the stressor on the third day. There was a 2‐hour pre‐stress rest, followed by a 1‐hour stress (involving a video game task), and a 2‐hour recovery. Percentage of body fat was obtained from DXA. U_NaV was measured hourly, whereas systolic BP and diastolic BP measurements were obtained at 15‐minute intervals, and averaged for each 1‐hour period. Results: There was no significant difference between the lean and overweight/obese group for the response of systolic BP and diastolic BP (group by time interaction, p = 0.60 and p = 0.64, respectively). However, the lean group had a significantly greater increase in U_NaV in response to the stressor compared with the overweight/obese group (p = 0.02). U_NaV remained elevated compared with baseline in both groups at the 1‐hour (p ≤ 0.0001) and 2‐hour (p ≤ 0.0001) post‐time points. Furthermore, there was a tendency for a larger number of sodium retainers in the overweight/obese group compared with the lean group (39.0% vs. 20.0%; χ² = 2.85, df = 1, p = 0.09). Discussion: This study provided evidence that sodium regulation was impaired during a behavioral stress in overweight/obese individuals compared with lean individuals.     

Effect of Changes in Fat Distribution on the Rates of Change of Insulin Response in Children

Objective: To develop mixed models for examining longitudinal associations between rates of change in visceral, subcutaneous abdominal, and total body fat with rates of change in fasting insulin (FI) and insulin sensitivity (SI) over 3 years in children. Research Methods and Procedures: Seventy-seven children (mean age, 8.3 years at baseline) from Birmingham, Alabama, with three or more annual measures of FI and SI were included. Abdominal fat was measured by computed tomography, and total body fat and lean tissue mass were measured by DXA. Mixed models examined the longitudinal associations between the baseline level/rate of change of different fat compartments and the rate of change in FI or SI. Results: An annual increase of ∼5% in FI was associated with 1 cm²/yr of visceral fat gain per year (p < 0.05), independent of subcutaneous abdominal fat. A 1-cm² difference in initial subcutaneous abdominal fat was associated with an ∼0.2% increase per year in FI (p < 0.02), independent of visceral fat. None of the rates of change in any of the fat measures was associated with the rate of change of SI. Discussion: The rate of change in visceral fat was positively associated with the rate of change in FI, independent of increasing subcutaneous abdominal fat; however, subcutaneous abdominal fat may be more predictive of the rate of change of FI than visceral or total fat. Therefore, growth-related increases in abdominal fat, particularly subcutaneous abdominal fat, may contribute to accelerating increases in FI, but have no effect on SI.     

种子顽拗性的形成机理及其保存技术

根据种子的脱水行为将种子分为正常性种子、顽拗性种子和中间性种子。顽拗性种子在发育的末期不经历成熟脱水．脱落时有相对高的含水量,并且对低温和脱水干燥非常敏感。在自然界,顽拗性种子存在一个连续群,即低度、中度和高度顽拗性种子,其差异在于对脱水伤害的敏感程度。影响种子顽拗性的因素,既有种子本身的生理生化物质基础,也有种子在母株上发育过程中所经受的外界环境的影响。目前,对种子脱水耐性的分子机制及其保存技术研究得较多。本文综述了有关顽拗性种子研究的近期进展。     

Insulin Sensitivity,Body Fat Distribution,and Family Diabetes History: The IRAS Family Study

Objectives : Markers of insulin resistance are often apparent in nondiabetic relatives of subjects with type 2 diabetes. Whether diabetes family history (FH) also predicts visceral fat accumulation and, if so, whether the increased insulin resistance in relatives of diabetic subjects occurs independently of visceral fat accumulation are not known. Research Methods and Procedures : To examine this issue, we studied the relationship of diabetes FH with insulin sensitivity and fat measures, measured by minimal model analysis and computed tomography, respectively, in families participating in the Insulin Resistance Atherosclerosis (IRAS) Family Study. FH scores were based on the diabetes status of the participants’ parents and older siblings. Results : FH scores were significantly correlated with reduced insulin sensitivity (p < 0.05) and increased subcutaneous (p < 0.05) and visceral (p < 0.05, San Antonio only) fat in families from San Antonio and Los Angeles but not in the leaner Hispanic families from San Luis Valley. There was no evidence for a stronger association of FH score with visceral fat accumulation than with subcutaneous fat or insulin resistance. Discussion : The absence of an association between FH score and insulin resistance/fat accumulation in San Luis Valley is consistent with the idea that the expression of transmitted diabetes genes may be suppressed in leaner, more physically active populations.     

cDNA芯片阳性对照的制备及在芯片敏感性分析中的应用

cDNA芯片是一种高通量基因表达谱分析技术,在生理病理条件下细胞基因表达谱分析,新基因发现和功能研究等方面具有广阔应用前景。CDNA芯片阳性对照的选取以及CDNA芯片检测敏感性是芯片成功应用的关键问题之一。以在系统发育上与人类基因同源性小的荧火虫荧光素酶基因材料,制备了用于人类和其他动物基因表达谱CDNA芯片的通用型阳性对照探针和相应的mRNA参照物,经反转录对mRNA参照物进行Cy3荧光标记并与DNA芯片杂交后发现,mRNA参照物能特异性地与荧光酶基因cDNA片断杂交,而与人β-肌动蛋白基因,人G3PDH基因以及λDNA/HINDⅢ无杂交反应。把mRNA参照物以不同比例加入HepG2总RNA中,以反转录荧光标记后与CDNA芯片杂交,结果发现当总RNA中的MRNA含量为1/10^4稀释（即mRNA分子个数约为10^8个）时,CDNA芯片基本检测不出mRNA标记产物的杂交信号。而且,cDNA芯片检测的信号强度与芯片上固定的探针浓度密切相关,当探针浓度为2g/L时,杂交信号最强,随着探针浓度下降芯片的杂交信号趋于减弱。CDNA芯片通用型阳性参照物的制备以及应用于CDNA芯片检测敏感性研究为CDNA芯片应用于人和其他动物基因表达谱高通量分析和新基因功能研究提供了技术基础和理论依据。     

Using GaBi 3 to perform life cycle assessment and life cycle engineering

The growing availability of software tools has increased the speed of generating LCA studies. Databases and visual tools for constructing material balance modules greatly facilitate the process of analyzing the environmental aspects of product systems over their life cycle. A robust software tool, containing a large LCI dataset and functions for performing LCIA and sensitivity analysis will allow companies and LCA practitioners to conduct systems analyses efficiently and reliably. This paper discusses how the GaBi 3 software tool can be used to perform LCA and Life Cycle Engineering (LCE), a methodology that combines life cycle economic, environmental, and technology assessment. The paper highlights important attributes of LCA software tools, including high quality, well-documented data, transparency in modeling, and data analysis functionality. An example of a regional power grid mix model is used to illustrate the versatility of GaBi 3.     

老年嗜麦芽窄食单胞菌院内肺炎92例临床分析

目的：分析和总结老年嗜麦芽窄食单胞菌医院获得性肺炎的临床特点及对抗生素耐药情况。方法：对92例老年嗜麦芽窄食单胞菌医院获得性肺炎的临床资料进行统计、分析。用VITEK－AMS微生物自动鉴定仪鉴定细菌,并用其配套GNS－KI或GNS－201卡测定该菌体外药敏及MIC50、MIC90。结果：92例患者均有基础疾病,以恶性肿瘤（占27．2％）最常见,其次为COPD伴呼吸衰竭（占23．9％）、脑血管意外（占17．4％）及糖尿病（占14．1％）。其中重症监护病号（ICU）病房患者占72％（66／92）。不合理使用广谱抗生素、激素使用、气管切开、意识障碍、化疗、放疗等为本病高危因素。临床表现：发热（97．8％）;咯嗽、咳痰（53．3％）;肺部影像学显示,89％患者表现为双下肺斑片状阴影。药敏试验,该菌耐药严重。结论：老年嗜麦芽窄食单胞菌医院获得性肺炎多发生在有各种基础疾病、免疫功能低下者,各种高危因素又促成本病发生,临床表现危重,复杂。该菌耐药率高,合理治疗有赖于药敏结果。