994 resultados para 226-3-10
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采用传统陶瓷烧结工艺,在无压还原气氛中低温制备了Yb^3+掺杂量高达10%(按摩尔计)的透明性良好的氧化镧钇激光陶瓷,研究了其在室温的吸收光谱、发射光谱以及荧光寿命。结果表明:掺Yb^3+氧化镧钇透明激光陶瓷具有宽的吸收和发射光谱以及长的荧光寿命。吸收峰位于902,942nm和968nm处,吸收截面分别为0.31×10^-20,0.45×10^-20cm^2和0.53×10^-20cm2:主发射峰位于1032nm和1075nm处,发射截面分别为1.05×10^-20cm^2和0.87×10^-20cm ^
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The potential of 1.3-μm AlGaInAs multiple quantum-well (MQW) laser diodes for uncooled operation in high-speed optical communication systems is experimentally evaluated by characterizing the temperature dependence of key parameters such as the threshold current, transparency current density, optical gain and carrier lifetime. Detailed measurements performed in the 20°C-100°C temperature range indicate a localized T0 value of 68 K at 98°C for a device with a 2.8μm ridge width and 700-μm cavity length. The transparency current density is measured for temperatures from 20°C to 60°C and found to increase at a rate of 7.7 A·cm -2 · °C-1. Optical gain characterizations show that the peak modal gain at threshold is independent of temperature, whereas the differential gain decreases linearly with temperature at a rate of 3 × 10-4 A-1·°C-1. The differential carrier lifetime is determined from electrical impedance measurements and found to decrease with temperature. From the measured carrier lifetime we derive the monomolecular (A), radiative (B), and nonradiative Auger (C) recombination coefficients and determine their temperature dependence in the 20 °C-80 °C range. Our study shows that A is temperature independent, B decreases with temperature, and C exhibits a less pronounced increase with temperature. The experimental observations are discussed and compared with theoretical predictions and measurements performed on other material systems. © 2005 IEEE.
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本发明涉及无指盘臭蛙胰岛素释放促进肽和在制药中的应用,属于生物医学技术领域。本发明通过常规的生物化学手段,从无指盘臭蛙皮肤分泌液中分离纯化得到胰岛素释放促进肽并测定其序列,按照所得的序列合成该多肽。无指盘臭蛙胰岛素释放促进肽是一种单链多肽,分子量2632.3道尔顿,等电点10.32,多肽全序列为:苯丙氨酸—亮氨酸—脯氨酸—亮氨酸—亮氨酸—丙氨酸—甘氨酸—亮氨酸—丙氨酸—丙氨酸—天冬酰胺—苯丙氨酸—亮氨酸—脯氨酸—赖氨酸—亮氨酸—苯丙氨酸—半胱苷酸—赖氨酸 —异亮氨酸—苏氨酸—精氨酸—赖氨酸—甘氨酸。本发明具有很好的促进胰岛素释放的作用,同时还具有无溶血活性、无血浆凝固活性等优点,可作为制备治疗糖尿病药物的应用。
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对养殖褐牙鲆( Paralichthys olivaceus) 的线粒体DNA Cytb 基因的部分序列进行测定,测得的目的DNA 片段的长 度为410 bp ,其A(104 bp) 、T(119 bp) 、C(117 bp) 、G(70 bp) 4 种碱基平均含量分别为25. 4 %、29. 0 %、28. 5 %、17. 1 %。 在28 个褐牙鲆个体中共出现了3 种单倍型。白化褐牙鲆出现的第1 种和第3 种单倍型个体数分别为10 尾(占白 化褐牙鲆样本数的90. 91 %) 和1 尾(9. 09 %) ;6 尾黑化褐牙鲆均出现第1 种单倍型(100 %) ;正常褐牙鲆出现的3 种 单倍型尾数分别为7 尾(占正常褐牙鲆样本数的55. 56 %) 、2 尾(22. 22 %) 和2 尾(22. 22 %) ;测得的序列与既知序列 间在第6 bp 、第19 bp 和第402 bp 碱基处出现差异。由于褐牙鲆Cytb 基因的高度同源性,研究其白化、黑化和正常 状态时出现的序列差异,对于寻找褐牙鲆白化机理研究的分子标记意义重大。
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Objective: To investigate the association of complement C4 null genes (C4QO, including C4AQO and C4BQO) and C2 gene with systemic lupus erythematosus (SLE) in southwest Han Chinese; 136 patients with SLE and 174 matched controls were genotyped. Methods: C4 null genes were determined by a polymerase chain reaction (PCR) procedure with sequence specific primers (PCR-SSP). The 2 bp insertion in exon 29, which was previously identified in non-Chinese populations and caused defective C4A genes, was directly typed by sequencing the whole exon 29 using exon specific primers. The exon 6 of complement C2 was also sequenced in both the patients and controls. Results: The frequency of homozygous C4AQO allele was 12.5% (17/136) in patients with SLE compared with 1.1% (2/174) in controls (p<0.001, odds ratio (OR)=12.286, 95% confidence interval (95% CI) 2.786 to 54.170). There was no significant difference for homozygous C4BQO allele between patients with SLE and controls (p=0.699). Patients with the C4AQO gene had an increased risk of acquiring renal disorder, serositis, and anti-dsDNA antibodies compared with those without C4AQO (for renal disorder, p=0.018, OR=8.951, 95% Cl 1.132 to 70.804; for serositis, p=0.011, OR 4.891, 95% CI 1.574 to 15.198; for anti-dsDNA, p=0.004, OR 7.630, 95%Cl 1.636 to 35.584). None of the patients or controls had the 2 bp insertion in exon 29 of the C4 gene. The type I C2 deficiency was not detected in the 3 10 samples. Conclusion: It is suggested that deficiency of C4A (not due to a 2 bp insertion in exon 29), but not C4B or C2, may be a risk factor for acquiring SLE in south west Han Chinese; this results in increased risk of renal disorder, serositis, and anti-dsDNA antibodies in patients with SLE. Racial differences seem to be relevant in susceptibility to SLE.
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用改进的方法从保存于本单位标本中提取DNA, 所得DNA片段的分子量从100bp到1kb以上。利用线粒体DNA细胞色素b通用引物和PCR技术。从小麂、印度麂、贡山麂、费氏麂、黑麂DNA中扩增出307bp的 细胞色素b特异片段(加上两端引物后长度为364bp)。用28种限制性内切酶对 新鲜血样和从陈旧皮张标本中所得扩增片段进行酶切分析, 发现只有4个酶(DraⅠ、xbaⅠ、HaeⅢ、HpaⅡ)在这个片段上有切点, 其中HaeⅢ和HapⅡ的识别位点在各种麂中有所不同。 图3参10
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烟草野蛞蝓是云南省景东县太忠乡烟草苗期的重要害虫。该虫在太忠山区烟地1 年发生5~6 代,世代重叠严 重,以幼体、成体和卵堆在田埂裂缝、地块间隙越冬。3 月上中旬~5 月中下旬当气温升达25~30 ℃时,气候干燥,而烟 苗地浇水或潮湿,野蛞蝓以幼体、成体入烟苗地取食危害烟草幼苗,造成缺苗、断苗或缺墒少垄。在室内控光条件下人 工饲养,其日取食活动除具昼夜时空规律外,同时明显受光照条件的影响。通过综合防治后,连续3 年在云南省景东 县太忠乡基本控制了该虫的发生危害,烟苗期发生危害面积由原来的10 %~15 %降为1 ‰~1. 5 ‰。
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本发明是一种蜜蜂电击振翅反应气味学习训练方法。该方法按以下步骤进行:1)捉取蜜蜂,放入冰中1-2分钟待蜜蜂麻醉后,将蜜蜂转移到特制电笼中,每笼20至40只; 2)适应1-3小时后,将装有蜜蜂的特制电笼放入气道箱中开始训练,每次训练时,给气持续时间10秒,电击在给气后5秒时开始施加,持续10秒,间隔20到30分钟进行下一次训练,每笼蜜蜂训练3-5次;3)检测时,给气10秒,无电击,记录蜜蜂的振翅反应。本发明的训练方法能有效地训练蜜蜂的振翅反应,经过训练的蜜蜂当嗅到特征气味时,就能产生振翅反应。这对于探测特征气味、缉毒缉爆、出入境安检等多项国防及民事安全工作提供了帮助。
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利用夏季自然发情的云南黄牛为受体,开展了奶牛体内冷冻胚胎移植.留用的114头受体牛中,本地黄牛59头,年龄在3~10岁,均为经产牛,最终移植27头,西杂牛56头(其中2岁以下的青年牛26头),移植29头(青年牛11头),两个品种受体利用率分别为45.8%和51.8%;移植后妊娠率分别为59.3%和55.2%;解冻的63枚胚胎移植给了56头受体牛,A级胚胎单独移植和B、C级胚胎搭配移植最终妊娠结果分别是58.5%(24/41)和53.3%(8/15);发情后第6 d和第7 d移植妊娠率分别为56%和58.1%.结果表明,1~10岁的西杂牛和3~10岁体型较大的本地黄牛均可作为受体移植奶牛胚胎;利用自然发情的云南黄牛做受体移植效果较为理想,是一种经济、方便、适合云南广大农村推广的技术途径;A级胚胎单独移植和B、C级搭配移植可获得较为理想的妊娠结果;处于发情后第6 d和第7 d的云南黄牛都可以作为桑囊期奶牛胚胎的移植受体.
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Nomascus亚属有3个有效种附8个亚种。白颊长臂猿H. leucogenys, 为单型种。红颊长臂猿H. gabriellae有2个亚种; 黑冠长臂猿H. concolor有6个亚种。并介绍了种的分布地。图1表3参10
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对墨江蜈蚣的分布、生活环境、生活习性做了初步研究。指出墨江蜈蚣的生 活期是3月中旬 至10月中下旬, 此期间的温度在18—23℃, 湿度75—85%, 降雨 量为50—280mm, 日照射数225—115h。蒸发量200—100mm。图1