The Influence of Magnesium Supplementation on Glucose and Lipid Metabolism of Rats with Type 2 Diabetes Mellitus

目的:研究镁补充对2型糖尿病大鼠糖脂代谢的影响。方法:将用高脂饮食联合链脲佐菌素(STz)方法诱发的2型糖尿病大鼠随机分为四个组,糖尿病对照组喂饲高脂饲料,高、中、低剂量组在高脂饲料中分别加入2000、1000、200 Mg/kg的镁(以镁离子计)。自由饮食喂养四周,处死动物。用放射免疫法测血清胰岛素(InS)水平、用葡萄糖氧化酶法测空腹血浆葡萄糖(fASTIng PlASMAgluCOSE,fPg),并计算胰岛素敏感指数(InSulIn SEnSITIVITy IndEX,ISI)。比色法检测糖化血红蛋白(glyCOSylATEd HEMOglObIn,HbA1C)。用全自动生化分析仪测高密度脂蛋白胆固醇(HIgH-dEnSITy lIPOPrOTEIn CHOlESTErOl,HdlC)、甘油三酯(TrIglyCErIdE,Tg)、总胆固醇(TOTAl CHOlESTErOl,TC)。结果:高剂量组的空腹血糖、空腹血清、糖化血红蛋白、甘油三酯、总胆固醇水平均较糖尿病对照组显著性降低(P<0.05),而高密度脂蛋白胆固醇、胰岛素敏感指数较糖尿病对照组显著性升高(P<0.05)。结论:镁补充可以提高2型糖尿病大鼠胰岛素敏感性,改善糖尿病大鼠的糖脂代谢情况。Objective: To investigate the effect of magnesium supplementation on glucose and lipid metabolism of rats with type 2 diabetes mellitus.Method: Rats with type 2 diabetes mellitus were induced with high fat diet and intraperitoneal injection with small dose of STZ,then they were divided into 4 groups randomly: high,medium,low magnesium supplementation groups and diabetes mellitus control group.Diabetes mellitus control group was feed with high-fat feed only.The dosage added in high-fat feed of the high,medium,low magnesium supplementation groups are 2000,1000,200 mg/kg(measured by Mg2+).All the rats ate and drunk freely.All rats were killed after four weeks.The serum insulin(Ins) level were tested with radiation immune method,fasting plasma glucose(FPG)were mea-sured with glucose oxidase method,and calculation the insulin sensitivity index(ISI).Glycosylated hemoglobin(HbA1c) was measured by chromatometry.High-density lipoprotein cholesterol(HDLC),triglyceride(TG),total cholesterol(TC) were measured by automatic biochemical analyzer.Results: FPG,Ins,TG,TC levels of high dose group was significantly lower compared with that in the diabetic control group(P<0.05),while HDLC,ISI increased significantly compared with that in the diabetic control group(P<0.05).Conclusion: Magnesium supplement can improve insulin sensitivity,improve glucose and lipid metabolism in type 2 diabetic rats

INFLUENCE of MAGNESIUM SUPPLEMENTATION ON INSULIN RESISTANCE AND THE INFINITY of RECEPTOR IN RATS WITH TYPE 2 DIABETES MELLITUS

目的观察镁补充对2型糖尿病大鼠胰岛素受体亲和力的影响。方法将用高脂饮食联合链脲佐菌素(STz)方法诱发的2型糖尿病大鼠随机分为4个组,糖尿病对照组喂饲高脂饲料,高、中、低剂量组在高脂饲料中分别加入2000、1000、200Mg/kg的镁(以镁离子计)。每周检测空腹血糖1次。自由饮食喂养4 W,处死动物。用放射性受体分析法测肝细胞胰岛素受体亲和力、放射免疫法测血清胰岛素(InS)水平、比色法检测糖化血红蛋白(HbA1C)和血浆丙二醛(MdA)、葡萄糖氧化酶法测空腹血浆葡萄糖(fPg),并计算胰岛素敏感指数(ISI)和抵抗指数(IrI)。结果高剂量组的高亲和力胰岛素受体结合常数(k1)为(4.76±0.08)x108l/MOl,低亲和力胰岛素受体结合常数(k2)与结合容量(r2)分别为(1.10±0.14)x106l/MOl,(8.49±0.43)x1013/Mg蛋白,均较糖尿病对照组显著性升高(P<0.05)。补镁第3 W开始高剂量组空腹血糖较糖尿病对照组显著性降低,高剂量组的胰岛素敏感指数较糖尿病对照组显著性升高,而胰岛素抵抗指数则显著性降低。结论镁补充可以提高2型糖尿病大鼠胰岛素受体亲和力,降低胰岛素抵抗。Objective To observe the influence of magnesium supplementation on the infinity of insulin receptor in rats with type 2 diabetes mellitus.Method The rats with type 2 diabetes mellitus were induced with high fat diet and intraperitoneal injection with small dose of STZ.They were randomly divided into 4 groups,i.e.high,medium,low magnesium(2000,1000,200 mg/kg Mg2+) supplementation groups and diabetes mellitus control group.FPG was measured weekly.All rats were killed after 4 w,and liver cells were tested with radiation receptor analysis of their combination constants and combined capacity.The serum insulin(Ins) level was determined with radioimmunoassay.FPG,glycosylated hemoglobin(HbA1c) and plasma malondialdehyde(MDA) were also measured,and insulin resistance index(IRI) and insulin sensitivity index(ISI) were calculated.Results: High affinity insulin receptor combination constant(K1),low affinity insulin receptor combination constant(K2) and combination capacity(R2) of high dosage group were(4.76±0.08)×108 L/ mol,(1.10±0.14)×106 L/ mol,(8.49±0.43)×1013 /mg protein respectively,significantly increased than those in diabetes mellitus control group(P<0.05).FPG was decreased since the 3th week during magnesium supplementation.The insulin sensitivity index(ISI) of high dosage group was significantly increased than that of model control group,but insulin resistance index(IRI) was decreased.Conclusion Magnesium supplementation could improve insulin receptor affinity and reduce insulin resistance in type 2 diabetic rats

不同施肥制度土壤微生物量碳氮变化及细菌群落16S rDNA V3 片段PCR产物的DGGE分析

Microbial biomass C and N content and analysis of soil bacteria with different fertilization systems were carried out based on a 15-year long term fertilizer experiment in Drab Fluvo-aquic soil in Beijing. At this site, 13 different treatments were established in 1990. Six treatments were chosen for this work: Four were in a wheat-maize rotation receiving either no fertilizer (Ck), mineral fertilizers mineral fertilizers plus farmyard manure (Npkm) or mineral fertilizers with maize straw incorporated One was in a wheat-maize/wheat-soybean rotation receiving (NPK Npkf). The other was abandoned arable land (Cko) growing weeds. The amount of chemical fertilizer per year was N 150 kg hm, P075 kghm; K0 45 kg hm; manure 22.5 t hm and maize straw 2.25 t hm. The results showed that microbial biomass C and N in the abandoned arable soil were higher than that in arable soils. Soil microbial biomass C and N in treatments with fertilizer input NPK, NPKM, NPKSt and NPKF were higher than that in CK ^without fertilization). The rotation of wheat-maize/wheat-soybean had higher microbial biomass C and N than continuous wheat-maize cropping. The ratio of microbial C to soil organic C (SMB-C/S0C) and microbial N to soil total N (SMB-N/TN) had similar trends to SMB-C and SMB-N. The community structure of bacteria microorganisms was assessed by denaturing gradient gel electrophoresis DGGE) and Unweighted Pair Group Method Clustering (UPGMC) analysis of the DGGE banding patterns showing that the bacterial community structure was affected by the treatments. The results indicated a significant increase in microbial diversity by fertilization treatments compared to that without fertilizer (CK). However the composition of the bacterial community in NPKM treatment was more complex than that in others. Cluster analysis of the DGGE profiles pointed out that bacteria in the six soils belonged to three clusters. Bacterial communities in CK and NPK soils belonged to one cluster; those in NPKF and CK0 soils to another cluster; and that in NPKSt and NPKM soil to a single cluster. The similarity of bacterial community in soils with six treatments was 53%. This study demonstrated that mineral fertilizer with farmyard manure increased both biomass and diversity of bacterial community in the soil

~(19)F+~(93)Nb重离子耗散碰撞中截面测量的不可重复性(英文)

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室温连续的新结构垂直腔面发射半导体激光器

报道了室温连续激射的GaAs/GaAlAS新结构垂直腔面发射半导体激光器的最新研究结果。该器件结构是采用钨丝掩膜四次质子轰击方法制备的,这种方法是目前报道的垂直腔面发射激光器制作工艺中最简单的。对于直径15μm的钨丝,器件的最低值电流为17mA,最大光输出功率达4mW,微分量子效率高达65％

InGaAs量子阱垂直腔面发射激光器

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重离子耗散反应激发函数中的截面涨落

完成了两次独立的 1 9F + 93Nb激发函数测量;束流 1 9F8+的入射能量 1 0 0～ 1 0 8MeV,能量步长 2 5 0keV。两次测量的宏观条件完全相同,实验结果有近 1/3的相同能量点所对应的反应截面及其涨落不重复。在双核系统中引入宇称和自旋的退相干描述能量自关联函数中准周期性的衰减结构;用量子混沌运动中初始条件的极端敏感性解释截面及其涨落的不重

~(19)F+~(93)Nb耗散反应产物激发函数中截面测量的不重复性

完成了 1 9F + 93Nb重离子耗散碰撞激发函数的两次独立测量 .束流的入射能量为 1 0 0— 1 0 8MeV ,步长 2 50keV .两次测量的宏观条件几乎完全一样 ,惟一的差别是使用了厚度分别为 70和 71 μg cm2 的两块 93Nb同位素靶 .实验结果表明 :( 1 )两次测量所得到的耗散反应产物激发函数的涨落具有不可平滑的结构 ;( 2 )这种不平滑的涨落截面有不重复的迹象 .着重从实验的角度对这一结果进行了讨论

~(19)F+~(93)Nb耗散反应的相互作用时间

测量了1 9F + 93Nb耗散反应产物的激发函数与角分布 .从角分布的斜率提取的该反应系统的平均寿命在对称性较大的入射系统中反映了系统中耗散产物的特征时间 ;通过能量自关联函数方法从激发函数提取的反应时间不论在对称的还是在非对称的入射系统中都反映了耗散产物的特征时间 .能量自关联函数还可以给出双核系统的转动角速度以及表征转动阻尼的退相干宽度 ,更好地描述双核系统随时间的整个演化过程

近70年来中国自然地理与生存环境基础研究的重要进展与展望

自然环境是人类赖以生存和发展的基础,探索自然环境及其各要素(如地貌、气候、水文、土壤等)的特征、演变过程、地域分异规律以及驱动机制是自然地理学的重点研究内容.中国自然地理要素类型丰富且区域差异较大,为开展自然地理研究提供了难得的机遇.文章主要围绕青藏高原隆升与亚洲内陆干旱化及河流发育、高原冰冻圈环境演化、全新世多时间尺度季风与西风气候变化、湖泊与湿地、流域模型与土壤侵蚀、过去人-地关系演化、生物地理及中国三维地带性规律等几个方面,梳理了近70年来中国自然地理与生存环境研究的重大理论进展与重要贡献.在简要交代国际前沿研究进展的基础上,回顾并梳理了中国自然地理学各分支领域的研究脉络,进一步聚焦重大研究成果或具有较大争议、重大影响的学术争鸣问题,归纳目前研究现状,并进行未来工作展望.最后提出在推进生态文明建设的国家需求下,应发挥中国自然地理研究的优势,厘清自然地理要素变化的过程、规律与机制,持续推进中国自然地理研究为国家战略服务,在全球视野下做出具有中国特色的自然地理学理论贡献