共查询到19条相似文献，搜索用时 140 毫秒
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进行了HA基因的DNA重组体pV—HA及融合HA—minigene基因的DNA重组体PHA—minigene的表达研究,测定了其凝血活性,并利用荧光示踪,间接免疫荧光等方法对其进行鉴定,鉴定结果表明：构建DNA重组体成功,且在哺乳动物细胞离体实验中检测到重组体的表达。 相似文献
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竹红菌甲素的溴化反应及产物的光物理与光化学 总被引：1，自引：0，他引：1
刘卫 《蒙自师范高等专科学校学报》1995,(4)
竹红菌甲素(Hypocrellin A,简称HA)是从生长在云南的竹上寄生真菌——竹红菌中分离得到的天然光敏色素,是我国首先发现和使用的一种新型光疗药物,配合可见光照射,可有效治疗多种顽固型皮肤病,最近还发现它具有较好的抗癌活性.目前竹红菌素研究的前沿是通过结构修饰筛选具有较大吸收波长(以便配合激光治疗)、较好水溶性和光稳定性、较高吸光能力和光动力活性的竹红菌素衍生物.本文进行了竹红菌甲素的溴化反应,并研究了溴化产物的光物理与光化学性质,发现它们是吸光能力,光动力活性及光稳定性均比甲素更优越的光敏化剂. 相似文献
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牛麟 《新疆教育学院学报》1999,(4)
对彩色电视画面中图像色彩的要求,除了某种艺术效果,有意造成偏色现象外,一般都想取得准确还原被摄物体色彩的效果。特别是电视教材色彩直接影响学习者对事物的正确认识以及电视教学的效果。但在拍摄时,经常会出现色彩还原失真的现象。影响被摄物体色彩还原的因素很多。电视照明就是其中一个重要的因素。人眼具有三种不同锥状光敏细胞,它们分别只对红色、绿色、蓝色光谱的能量的刺激产生视觉反映。三种光敏细胞所受到的视觉刺激分别为：Sr（λ）、Sg（λ）、Sb（λ）分别表示人眼三种不同锥状光敏细胞的光谱灵敏度响应特性,r（λ）… 相似文献
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通过PCR扩增高致病性禽流感H5N1的HA和HA1基因片段,利用原核表达系统表达重组HA和HA1蛋白,并用SDS-PAGE,Western-blotting和血凝试验进行重组HA蛋白的鉴定和血凝活性鉴定.结果表明,经过HA蛋白胞外段分析、重组载体的酶切鉴定得出的重组HA蛋白,在血凝试验中能与HA特异性抗体结合,并有较高的血凝活性.利用表达载体pET42a表达AIV-H5亚型的HA基因,为进一步利用重组蛋白研制AIV-H5抗体的ELISA检测方法,研制抗AIV-H5亚型的单克隆抗体提供基础. 相似文献
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本文综合了经典的和最近的一些研究资料,根据植物光周期诱导与光敏色素的关系,光敏色素的物理化学性质及其在植物体内和细胞中的分布和定位、光周期诱导过程中物质代谢的变化,建立了一种光敏色素控制植物开花的分子模型。此模型称为光敏色素-光感蛋白-cAMP环化酶或其它诱发产生第二信使的蛋白质的偶联模型。 相似文献
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课本中采用光敏二极管控制继电器（如图1所示）： 光敏二极管通过放大器B控制继电器J，受光（手电筒）照射时，光电流使继电器动作，切断小灯泡L的电路，小灯泡熄灭。 改用光敏二极管控制可控硅（如图2所示）： 光敏二极管受光（手电筒）照射时，使可控硅导通，灯泡变亮。 此电路中元件少，电路简单。灯泡效果跟图1相反，光敏二极管受光照射时，灯泡变亮，学生对光敏二极管的导电特性更为直观。 为了满足学生的好奇心和观察兴趣，我们在灯泡发亮的基础上，又增加一个音乐效果，改用光敏二极管控制开关三极管（如图3所示）： 光敏二极管受… 相似文献
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向丽 《绵阳师范学院学报》2007,26(12):113-115
感光材料是伴随着摄影技术的产生而出现的。传统摄影在经历了从黑白感光材料到彩色感光材料的发展历程后,已被认为是进入了"彩色时代"。从摄影整体看,拍摄彩色片已占80%以上。彩色感光材料的种类繁多,本论文主要是对彩色摄影感光材料中的彩色负片和银漂法彩色感光材料的性能特点进行重点分析和比较,从而使摄影者对这两类彩色感光材料有更理性的了解和认识。 相似文献
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指出了光印法制作PCB时有两种不同的感光材料即正性感光材料与负性感光材料之分;介绍了基于Protel99 SE的负性预涂布感光覆铜板的PCB设计方法;并简要给出了光印PCB的制作工艺。 相似文献
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Dan-li Fu Qiao-hong Jiang Fu-ming He Guo-li Yang Li Liu 《Journal of Zhejiang University. Science. B》2012,13(5):364-371
The purpose of this study was to analyze the effect of strontium-substituted hydroxyapatite (Sr-HA) on bone osseointegration
of the implants using fluorescence microscopy. We allocated 20 implants to two groups: Sr-HA group and HA group. Electrochemically
deposited HA and Sr-HA coatings were applied onto the implants separately. All the implants were inserted into femur bone
of rabbits. Oxytetracycline hydrochloride, alizarin-complexon, and calcein green were respectively administered 7, 28, and
46 d after the implantation. After eight weeks, femurs were retrieved and prepared for the fluorescence microscopy observation.
We analyzed the bone mineral apposition rates (MARs), bone area ratios (BARs), and bone to implant contact (BIC) of the two
groups. Fluorescence microscopic observation showed that all groups exhibited extensive early peri-implant bone formation.
The MAR of the Sr-HA group was greater than that for pure HA from 7 to 28 d after implantation, but no significant difference
was found at later stage. And the BIC showed difference at 7 and 28 d compared with pure HA. We concluded that Sr-HA coating
can improve the bone osseointegration of the implant in the early stage compared with the HA coating. 相似文献
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研究目的：腐殖酸（HA）对富勒烯（C60）粉末的悬浮作用以及pH、离子强度对HA-C60悬浮性能的影响。创新要点：研究水质条件对C60悬浮性能的影响。研究方法：测定C60粉末在HA溶液中的zeta电位,水力学粒径和悬浮浓度;HA存在下,C60悬浮体系的zeta电位与水力学粒径随pH的变化及C60悬浮体系团聚动力学随离子强度的变化。重要结论：HA对C60粉末起到一定的分散作用,但不能使其长时间稳定悬浮于水中。当pH〈4时,C60水悬液开始沉淀;而当HA存在时,C60水悬液在pH 3-11范围内都保持稳定,这是由于HA吸附于C60表面,通过静电排斥和空间位阻作用,促进C60分散悬浮。C60水悬液的稳定性随盐离子价位和浓度升高而降低。HA会抑制Na＋对C60水悬液的脱稳作用;但高价离子Ca2＋和La3＋存在时,HA与C60之间会发生桥联从而促进C60水悬液脱稳沉淀。 相似文献
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Yun Wu Yi-ping Xia Jia-ping Zhang Fang Du Lin Zhang Yi-di Ma Hong Zhou 《Journal of Zhejiang University. Science. B》2016,17(11):892-904
Bulblet development is a problem in global lily bulb production and carbohydrate metabolism is a crucial factor. Micropropagation acts as an efficient substitute for faster propagation and can provide a controllable condition to explore bulb growth. The present study was conducted to investigate the effects of humic acid (HA) on bulblet swelling and the carbohydrate metabolic pathway in Lilium Oriental Hybrids ‘Sorbonne’ under in vitro conditions. HA greatly promoted bulblet growth at 0.2, 2.0, and 20.0 mg/L, and pronounced increases in bulblet sucrose, total soluble sugar, and starch content were observed for higher HA concentrations (≥2.0 mg/L) within 45 d after transplanting (DAT). The activities of three major starch synthetic enzymes (including adenosine 5′-diphosphate glucose pyrophosphorylase, granule-bound starch synthase, and soluble starch synthase) were enhanced dramatically after HA application especially low concentration HA (LHA), indicating a quick response of starch metabolism. However, higher doses of HA also caused excessive aboveground biomass accumulation and inhibited root growth. Accordingly, an earlier carbon starvation emerged by observing evident starch degradation. Relative bulblet weight gradually decreased with increased HA doses and thereby broke the balance between the source and sink. A low HA concentration at 0.2 mg/L performed best in both root and bulblet growth. The number of roots and root length peaked at 14.5 and 5.75 cm, respectively. The fresh bulblet weight and diameter reached 468 mg (2.9 times that under the control treatment) and 11.68 mm, respectively. Further, sucrose/starch utilization and conversion were accelerated and carbon famine was delayed as a result with an average relative bulblet weight of 80.09%. To our knowledge, this is the first HA application and mechanism research into starch metabolism in both in vitro and in vivo condition in bulbous crops. 相似文献
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腐殖酸对钴、镉作用的研究 总被引：10，自引：0，他引：10
本文采用碱溶酸沉法提取土壤中的腐殖酸,研究对Co2+、Cd2+的吸附作用机理.结果表明:最佳pH范围为6～7,吸附过程属于放热过程.用该种腐殖酸样品吸附Co2+服从Langmuir和Freudlich吸附等温模型,19℃、35℃、45℃的饱和吸附量为12.51、9.52、8.30mg/g;吸附Cd2+在19℃、35℃时服从Langmuir和Freundlich吸附等温模型,饱和吸附量为33.90、33.43mg/g,但在45℃时主要服从Freundlich吸附等温模型.腐殖酸对Co2+、Cd2+的吸附是通过两级络合反应形成配合物的方式结合. 相似文献
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To understand the feasibility of its application to the in situ remediation of contaminated groundwater, the dechlori-nation of 2,4-dichlorophenol (2,4-DCP) by Ni/Fe nanoparticles in the presence of humic acid (HA) was investigated. We found that, as high performance liquid chromatography (HPLC) was used, the 2,4-DCP was first quickly reduced to o-chlorophenol (o-CP) andp-chlorophenol (p-CP), and then reduced to phenol as the final product. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles, as the HA concentration increased, the removal rate decreased evidently. It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP, and that the sequence of the tendency in dechlorination of intermediates was p-CP>o-CP. Transmission electron microscope (TEM) showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate. Also we con-cluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination. 相似文献