981 resultados para 10-93


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Axillary clearance in early breast cancer aims to improve locoregional control and provide staging information but is associated with undesirable morbidity. We therefore investigated whether avoiding axillary surgery in older women would result in improved quality of life (QL) with similar disease-free survival (DFS) and overall survival (OS).

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The Cu2SnS3 thin films were deposited using an economic, solution processible, spin coating technique. The films were found to possess a tetragonal crystal structure using X-ray diffraction. The film morphology and the particle size were determined using scanning electron microscopy. The various planes in the crystal were observed using transmission electron microscopy. The optimum band gap of 1.23 eV and a high absorption coefficient of 104 cm-1 corroborate its application as a photoactive material. The visible and infrared (IR) photo response was studied for various illumination intensities. The current increased by one order from a dark current of 0.31 mu A to a current of 1.78 mu A at 1.05 suns and 8.7 mu A under 477.7 mW/cm(2) IR illumination intensity, at 3 V applied bias. The responsivity, sensitivity, external quantum efficiency and specific detectivity were found to be 10.93 mA/W, 5.74, 2.47% and 3.47 x 10(10) Jones respectively at 1.05 suns and 16.32 mA/W, 27.16, 2.53% and 5.10 x 10(10) Jones respectively at 477.7 mW/cm(2) IR illumination. The transient photoresponse was measured both for visible and IR illuminations. (C) 2016 Author(s).

Relevância:

60.00% 60.00%

Publicador:

Resumo:

利用发根农杆菌(Agrobacterium rhizogenes)1601,1000,1500,15834,A4,均成功地转化了中药青蒿(Artemisia annua L.)并且建立了pRi1601,pRi15834,pRiA4诱导的发根培养。pRi1601,pRi15834的发根诱导率比其它质粒高。太老或太幼的叶片不利子发根的诱导;发根主要从叶脉的伤口处萌发;带顶芽或带侧芽的叶片容易诱导根,但不一定是发根。光照有利于发根的诱导和发根的生长。以每个发根的“绝对生长速率”(Gtowth Ratio,GR)和绝对“侧根”数量(Number of Side Roots,NSR),通过大量的发根系的筛选,建立了8个发根系,1601-L-1, 1601-L-2, 1601-L-3, 1601-L-4, 15834-L-1, 1601-P-I, 16 01-P-2,15834-L-2。Southern分子检测表明,160l-1-1,1801-L-2, 1601-L-3,1601-L-4,1601-P-1,1601-P-2均为转化子。8个建立的发根系之间无论生长或者QHS的合成存在明显的差异。比较光/暗(16/8hrs),25℃条件下培养的16 01-L-1,1601-L-2,1601-L-3,1601-L-4,1601-P-l,和1601-P-2,其中16 01-L-3的生长最快,160l-L-1的生长最慢;但是,1601-L-1的QHS的含量最高(可达1. 048%),1601-1-3的QHS的含量最低。160Z-L-3,15834 -L-1和2583:1-L-2的生长速率相差不大。用盛有l000mLMS液体培养基的3000mL的锥形瓶扩大培养1601-L -3,15834-L-1和15834-L-2,转速为ll0rlpm,培养过程中发根容易形成发根球(Hairy Root Balis,HRB),HRB的形成严重影响发根的生长和QHs的合成,HpLC分析表明扩大培养发根中QHS的含量比较低。 改变MS基本培养基中的无机离子的浓度,研究不同无机离子对发根生长和QHS的合成的影响。 l、KN03为18.79×10-3M时有利于1601- L-1生长,为14. 84×10-3M时有利于QHS的合成。NH-4N0-3浓度在10.93-12. 49×10—3M范围内有利于1601-L-1生长,在0-20.62×10-3M范围内对QHS的合成影响不大,大于20. 62×lO-3M不利QHS的合成。培养基中NH-4+/N0-3-比值为0. 37-0. 4-0.52:1时有利于发根的生长,比值为0.52 - 0.58:1时有利于QHS的合成。 2、H-2P0-4-浓度为2.498×10-3M时有利于发根的生长在0-2. 498×l0-3M范围内,随着浓度的提高,促进发根的生长。培养基中的H2P4 -的浓度在0-1.249×lO-3M的范围内,随着浓度的提高,促进QHS的合成,为1.249×10-3M时QHS的含量最高。 3、培养基中最适16 01-L-1生长的Ca-2+浓度为0.198- 0.766×10-3M,大于或小于该浓度范围,显著地抑制发根的生长。但是,在0-3.695×10-3M范围内,随着培养基中Ca-2+浓度提高,促进QHS的合成,最适Ca-2+浓度为3.695×l0-3M。 4、培养基中不加Mg-2+时,完全抑制发根生长,在0. 142×10-3M-7.506×l0-3M浓度范围内,对发根生长影响没有明显的差别。但是,HPLC和UV分析发根中QHS含量,培养基中不加Mg-2+时,发根中QHS含量最高。 5、培养基中的Fe-2+浓度在0. 25 -1.0×10-3M范围内,同时有利于16 01- L-1的生长和QHS的形成。 6、培养基中最适合予16 01- L-3生长的KI浓度为2.5ppm,大于或小予该浓度均显著地抑制发根的生长,培养基中加入KI明显地降低发根中的QHS的含量。 7、H2BO3对l601-L-l生长影响不大,HPLC分析QHS的含量,培养基中的H3BO3浓度为100ppm和400ppm,QHS的含量分别为1.69mg/g和1.80mg/g(DW)。 8、Cu-2+对1601-L-3的生长影响显著,最适合1601-L-3生长的Cu-2+浓度为1.00ppm,在0 -1.00ppm的浓度范围内,随着培养基中的Cu+浓度的提高,发根的生物量不断增加。培养基中QHS合成的最适Cu2+浓度为0.05ppm,大于或小于该浓度均显著地抑制发根中QHS的合成。 比较光培养和暗培养对发根生长的影响,结果表明光照明显地促进1601-L-l的生长,暗培养明显不利于发根的生长。最适合于发根生长的温度为25℃,大于35℃显著地抑制发根的生长,影响发根的根尖细胞的正常分裂。 改变培养基中的蔗糖浓度和在发根培养的不同时期给培养基中添加蔗糖,试验结果表明蔗糖作为碳源对1601-L-3和1601-L-1的生长具有显著的影响。 (1)培养基中缺少蔗糖显著地抑制发根的生长。 (2)发根培养的前5天时间内,蔗糖浓度为30- 60glL昀培养基最有利于发根的生长,50glL的培养基中的发根生长最快,培养基中的蔗糖浓度大于60g/L小于30g/L时,发根的生物量增加较少。 (3)发根培养至第15天时,蔗糖浓度为60g/L的培养基最有利予发根的生物量的增加。发根培养至30天时,蔗糖浓度为60-90g/L的培养基,发根的生物量的增加相差不大,但是为蔗糖浓度为30-40g/L的培养基中的发根生物量一倍。 (4)发根培养过程中,分别于第5和15天给蔗糖浓度为30g/L的培养基中添加一次或二次蔗糖,使培养基中的蔗糖终浓度相当于60g/L或90g/L,培养至30天时,添加蔗糖的培养基中的发根的干重生物量相当于不添加蔗糖培养基中的发根生物量一倍,相当于初始蔗糖浓度为60g/L和90g/L培养基中发根的生物量。 (5)随着培养基中蔗糖浓度的提高,发根干重/鲜重比显著增加。培养基中的蔗糖的消耗量与发根生物量的增加呈正相关,蔗糖消耗越多,发根生物量的增加越大。 比较pH值对发根生长和QHS合成的影响表明,灭菌前pH值在5.O-6.5范围内的培养基适合予1601-L-1的生长,小于5.O不利于发根的生长,pH5.8有利于1601-1-1生长和QHS的生物合成。发根收获时培养基中的pH值一般为4.5-5.2. pH7.O抑制发根的生长,pHl0.O对发根具有强烈的致死作用。发根在培养过程中,对培养基中的pH值具有显著的调节作用,发根能在很短的时间内(24- 48hrs)使pl:l值为5.8、6.4、7.0培养基降低到pH4. 5-5.2,pH为5.8的培养基有利于QHS合成。 比较不同基本培养基对发根生长和QHS合成的影响,试验结果表明N6、DCR、Litvay培养基有利于1601-L-1的生长,WS、White、B5培养基不利于发根的生长。DCR培养基中的QHS含量最高。 根据三水平试验选用三水平正交表来安排试验的原则,选用三水平正交表L7(3-),研究多因子效应对发根生长和QHS合成的影响,试验结果表明,Mg2+,Fe2+,Mn-2+,NH4NO3,KN03 ,KI,Ca-2+为发根生长的主要因子,NH4N03,KNOs,Mg2+,Ca2+,肌醇为QHS合成的主要因子。 通过TLC分析发根中QHS和其它化学成分,同时比较发根和无菌苗及野生植株的化学成分,发根和无菌苗均能合成包括QHS在内的野生青蒿叶片中的大部分非挥发性的化台 物。 研究青蒿植株在发育过程中QHS的含量的变化以及发根、无菌苗和野生青蒿中QHS的合成,HP分析结果表明,l、不同的单株青蒿之间的QHS量相差很大。2、同一植株幼 叶的QHS含量比老叶的QHS含量高。3、不同单株青蒿之间达到最高QHS含量的时间不一样,开花期或开花之前。4、无菌苗(带根)或者不带根丛生芽均能合成QHS,但是带根的无菌蕾的QHS量比丛生芽中的QIS的含量高。5、不同发根农杆菌转化的发根系1601-L-1和15834-L-1都能合成QHS。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A comparative study was carried out between the two biggest creeks along the Arabian Gulf coast of the United Arab Emirates to evaluate impacts of sewage and industrial effluents on their hydrochemical characteristics. Surface and bottom water samples were collected from Abu Dhabi and Dubai creeks during the period from October 1994 to September 1995. The hydrochemical parameters studied were: temperature (21.10-34.00°C), salinity (37.37-47.09%), transparency (0.50-10.0 m), pH (7.97-8.83), dissolved oxygen (1.78-13.93 mg/l) and nutrients ammonia (ND- 13.12,ug-at N/1), nitrite (ND-6.66 ,ug-at N/1), nitrate (ND- 41.18 ,ug-at N/1), phosphate (ND- 13.06 ,ug-at P/1), silicate (0.68-32.50 ,ug-at Si/1), total phosphorus (0.26- 21.48 ,ug-at P/1), and total silicon (0.95- 40.32 ,ug-at Si/1). The present study indicates clearly that seawater of Abu-Dhabi Creek was warmer (28.l2°C) than Dubai (27.56°C) resulting in a higher rate of evaporation. Owing to more evaporation, salinity levels showed higher levels at Abu Dhabi (43.33%) compared to Dubai (39.03%) seawater. The study also revealed higher secchi disc readings at Abu Dhabi Creek (4.68 m) as compared to Dubai Creek (2.60 m) suggesting more transparency at Abu Dhabi Creek. Whereas, seawater of Dubai exhibited higher levels of pH (1.03 times), and dissolved oxygen (1.05 times) than Abu Dhabi seawater due to an increase in productivity. Meantime, seawater of Dubai showed higher tendency to accumulate ammonia (8.22 times), nitrite (10.93 times), nitrate (5.85 times), phosphate (10.64 times), silicate (1.60 times), total phosphorus (3.19 times), and total silicon (1.54 times) compared to Abu Dhabi seawater due to the enrichment of seawater at Dubai with domestic sewage waters which has distinctly elevated the levels of the nutrient salts particularly in inner-most parts of the creek leading to eutrophication signs. The changes occurred in the receiving creek water of Dubai as a result of waste-water disposal that have also reflected on the atomic ratios of nit: Effect of pollution rogen: phosphorus: silicon.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

特殊环境中的事件区域检测是无线传感器网络的一种重要应用.由于传感器的错误会导致事件区域检测的不准确,所以相关的容错算法成为近年来的研究热点.已有研究工作都仅考虑了事件的空间相关性,通过相邻传感器之间的数据交换实现容错.文中从事件的空间相关性和时间相关性入手,提出了一种以局部检测为主的分布式事件区域检测算法.该算法通过检验传感器本地采样值构成的时间序列与事件随机过程统计特征的符合程度实现容错.算法分析的结果表明,该算法可以减少传感器之间的数据交换,从而有效地利用传感器的能量.模拟实验表明,当有10%的传感器发生错误时,该算法可以检测到93%的事件区域和88%的错误传感器.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

以农田和不同退耕还林年限(5、10、15年)的杨树人工林为对象,开展了退耕还林对生态系统有机碳储量和分配格局特征的研究。结果表明:随着退耕年限的增加,生物量碳储量不断积累,且其增加的碳库主要分配在树干。与农田(CK1)相比,退耕还林5年的杨树人工林(Poplar1)0~10、10~20、20~40和40~60cm土壤有机碳含量分别下降了7.65%、36.66%、51.94%和21.4%;退耕还林10年的杨树人工林(Poplar2),不同层次土壤有机碳含量分别提高了69.63%、62.46%、17.07%和66.94%。与农田(CK2)相比退耕还林15年的杨树人工林(Poplar3),0~10、20~40和40~60cm土壤有机碳含量分别提高了31.96%、81.50%和58.05%,而10~20cm土层下降了13.38%。与对照农田相比,5年生杨树人工林0~60cm土壤有机碳储量下降了31%,而10年和15年生杨树人工林土壤有机碳储量分别增加了47%和41%。退耕5年的杨树人工林总的碳储量比对照农田下降了10%,退耕10年和15年的杨树人工林与相应对照农田相比较,生态系统总的碳储量分别提高大约2倍和5倍。说明,农田退耕还林后生态系统碳储量明显增加,增加的碳储量主要积累在地上生物量碳库中。退耕还林初期,土壤有机碳储量表现出下降趋势,随后逐渐恢复甚至高于农田土壤碳储量。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

海洋浮游纤毛虫是在海洋中浮游生活的一类单细胞原生动物,主要是指寡毛类纤毛虫(Oligotrich ciliates),隶属原生动物界(Protozoa)、纤毛门(Ciliophora)、寡毛纲(Oligotrichea),分属于Oligotrichina 和Tintinnina两个亚纲。它们个体微小,粒径在5-200 µm之间,是微型浮游动物和海洋微食物环(Marine Microbial Food Web)的重要组成部分。 2006年4月至2007年12月,在黄海(包括胶州湾)采样分析海洋浮游纤毛虫的种类组成(砂壳纤毛虫)、丰度和生物量,分析纤毛虫在这一海区的季节变化和空间变化。 纤毛虫丰度和生物量的研究方法为:Rosette采水器(胶州湾用Niskin采水器)采集水样,取1 L水样,加Lugol’s试剂固定(终浓度1%),Utermöhl方法100倍镜检。测量虫体的体长、体宽,按最接近的几何形状(圆柱体、球体和圆锥体)计算体积。生物量由体积乘转换系数(0.19 pgC/µm3)得到,砂壳纤毛虫的肉体体积按照壳体积的1/3近似。 本文的结果表明,胶州湾各站纤毛虫平均丰度于6月达到全年最高值6065 ind./L,12月为全年丰度最低值843 ind./L。平均生物量8月达全年最高值(18.5 µg C/L),6月为全年最低值(0.6 µg C/L)。砂壳纤毛虫种丰富度于8月达到最高值,共发现25种砂壳纤毛虫,1月种类最少(6种)。湾内站位的纤毛虫平均丰度比湾外的高(6月和8月除外)。砂壳纤毛虫在纤毛虫总丰度中的比例较小,平均为25%,范围为8-57%,分别于1月和8月达到最低和最高值。 两次冷水团大面调查结果表明,4月表层纤毛虫平均丰度(1490 ind./L)要高于10月(972 ind./L)。10月表层纤毛虫生物量0.14-5.33 µg C/L,14194站、15694站和15894站生物量较高,为4.08-5.33 µg C/L。无壳纤毛虫优势种Laboea strobila在两个航次中均呈现斑块分布,4月航次丰度0-10000 ind./L,10月航次丰度11-350 ind./L;砂壳纤毛虫优势种Ptychocylis obtusa仅在4月航次发现,最大丰度2895 ind./L,10月航次未发现。4月航次砂壳纤毛虫有百乐拟铃虫(Tintinnopsis beroidea),丰度为0-1920 ind./L;卡拉直克拟铃虫(Tintinnopsis karajacensis),丰度很小(10-93 ind./L)。10月航次砂壳纤毛虫优势种Tintinnidium primitivum,丰度为35-700 ind./L;也出现了尖底类瓮虫(Amphorellopsis acuta)和网纹虫(Favella spp.),但丰度不大(0-210 ind./L);运动类铃虫(Codonellopsis mobilis)、筒状拟铃虫(Tintinnopsis tubulosoides)和Eutintinnus sp.丰度也较低(35-105 ind./L);Craterella torulata丰度为0-120 ind./L,主要分布于15694站。10月航次已经出现了温跃层,位于30 m左右水层,纤毛虫主要分布于温跃层之上。 六次黄海断面航次表明:温跃层在5月已经出现,到12月消失。在有温跃层的5月、6月、8月、9月,纤毛虫主要分布于温跃层(30 m左右)之上。其中8月份航次纤毛虫丰度最高,表层平均丰度3103 ind./L。12月份纤毛虫丰度最低,表层平均丰度406 ind./L。纤毛虫生物量春夏季为0.02-5.5 µg C/L,冬季为0.04-1.99 µg C/L。小型无壳纤毛虫占优势,砂壳纤毛虫东方拟铃虫(Tintinnopsis orientalis)、筒状拟铃虫、运动类铃虫、Craterella torulata和Tintinnidium primitivum几乎在各个航次均有分布。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The aim of this study is to evaluate lighting conditions and speleologists’ visual performance using optical filters when exposed to the lighting conditions of cave environments. A crosssectional study was conducted. Twenty-three speleologists were submitted to an evaluation of visual function in a clinical lab. An examination of visual acuity, contrast sensitivity, stereoacuity and flashlight illuminance levels was also performed in 16 of the 23 speleologists at two caves deprived of natural lightning. Two organic filters (450 nm and 550 nm) were used to compare visual function with and without filters. The mean age of the speleologists was 40.65 (± 10.93) years. We detected 26.1% participants with visual impairment of which refractive error (17.4%) was the major cause. In the cave environment the majority of the speleologists used a head flashlight with a mean illuminance of 451.0 ± 305.7 lux. Binocular visual acuity (BVA) was -0.05 ± 0.15 LogMAR (20/18). BVA for distance without filter was not statistically different from BVA with 550 nm or 450 nm filters (p = 0.093). Significant improved contrast sensitivity was observed with 450 nm filters for 6 cpd (p = 0.034) and 18 cpd (p = 0.026) spatial frequencies. There were no signs and symptoms of visual pathologies related to cave exposure. Illuminance levels were adequate to the majority of the activities performed. The enhancement in contrast sensitivity with filters could potentially improve tasks related with the activities performed in the cave.