乌鳢线粒体DNA细胞色素b序列的研究

目的:研究乌鳢线粒体DNA细胞色素b全序列。方法:以乌鳢的肌肉组织为材料,采用苯酚-氯仿法提取乌鳢DNA,然后将乌鳢线粒体DNA细胞色素b基因进行PCR扩增及其序列测定。结果:乌鳢线粒体细胞色素b全序列长度为1141 bp,编码蛋白含380个氨基酸残基。其T、C、A、G分别为26.0%,35.0%,24.1%和14.9%。A+T含量50.1%,高于G+C含量(49.9%)。结论:乌鳢线粒体DNA细胞色素b序列的碱基组成与含量与其他鱼类相似。     

NDV感染体外诱导胃癌细胞BGC-823的凋亡

目的 :研究新城疫病毒在体外抗胃癌细胞活性及其与细胞凋亡的关系。方法 :应用倒置显微镜观察细胞形态、MTT法测NDV在体外对BGC - 82 3的抑制和杀伤作用 ,同时用流式细胞术检测胃癌细胞凋亡情况及细胞分裂周期各时象的变化。结果 :NDV在体外可使BGC - 82 3胃癌细胞形成明显的细胞病变效应、细胞生长抑制及细胞凋亡 ,且细胞凋亡率与感染时间呈正相关。G2、S期细胞减少 ,增殖指数 (PI)降低 ,与阴性对照组比较有显著性差异 (P<0 .0 1)。结论 :NDV具有显著的抗BGC - 82 3胃癌细胞活性。     

双酶法水解寻氏肌蛤蛋白制备抗氧化肽的研究

文章以寻氏肌蛤为原料制备抗氧化肽,研究木瓜蛋白酶—复合蛋白酶双酶法酶解寻氏肌蛤的工艺条件。以1,1-二苯基-2-苦肼基(DPPH)自由基清除率为测定指标,通过单因素和正交试验确定双酶法制备抗氧化肽的最佳条件。结果显示:pH6.0,酶比例1∶1,[E]/[S]8%,酶解温度60℃,酶解时间6.5h为最佳酶解条件。验证试验表明,在此条件下,抗氧化肽对DPPH自由基清除率为68.70%。     

3种抗HBV核苷(酸)类似物体外抗乙肝病毒作用

比较3种抗HBV核苷(酸)类似物(拉米夫定、恩替卡韦、替诺福韦)对HepG 2.2.15细胞的毒性作用和对HBsAg、HBeAg和HBV-DNA表达的抑制效果。用四甲基噻唑蓝(MTT)法检测药物的细胞毒性;酶联免疫(ELISA)法检测HBsAg和HBeAg表达水平;PCR-荧光探针法定量检测HBV-DNA含量。结果:在最高浓度200 mg/L时,拉米夫定组存活率为74.72%,恩替卡韦组存活率仅为36.74%,替诺福韦组存活率为95.22%;拉米夫定和替诺福韦对HBsAg、HBeAg表达无明显抑制,恩替卡韦对HBsAg、HBeAg表达有抑制并与其细胞毒性相一致。在第9天,3种药物对HBV-DNA抑制作用明显,在6.25 mg/L浓度时,抑制率均高于90%;3种药物在相同药物浓度下,恩替卡韦对HepG 2.2.15细胞毒性最大,替诺福韦几乎没有细胞毒性,拉米夫定有一定毒性。     

淮河青虾线粒体细胞色素氧化酶Ⅰ序列的研究

目的:研究青虾线粒体细胞色素氧化酶Ⅰ全序列。方法:以青虾肌肉组织为材料,采用苯酚-氯仿法提取青虾DNA,然后对青虾线粒体细胞色素氧化酶Ⅰ基因进行了PCR扩增和测序。结果:青虾线粒体细胞色素氧化酶Ⅰ全序列长度为1535bp,编码蛋白含511个氨基酸残基。其中A、T、C、G分别为30.0%、30.6%、22.5%和16.9%。T+A含量(60.6%)明显高于G+C含量(39.4%)。结论:青虾线粒体细胞色素氧化酶Ⅰ序列的碱基组成与含量与其他沼虾类相似。     

大鼠睾丸支持细胞的分离培养及鉴定

目的:通过改进大鼠睾丸支持细胞的分离方法,获得高纯度支持细胞。方法:选用18~22日龄雄性Sprague Dawley(SD)大鼠,去除睾丸被膜、剪碎组织块,采用0.25%胰酶和0.1%Ⅳ型胶原酶单次消化,分别在37℃水浴震荡消化15min、10min,经100目细胞筛过滤收集细胞,置于37℃、5%CO2培养箱中进行培养,24h后大多数细胞完全贴壁,观察细胞生长,待长满培养瓶80%进行传代培养。显微观察不同时间段、不同代睾丸支持细胞的形态,采用免疫荧光方法对睾丸支持细胞进行鉴定。结果:显微观察可见分离培养的支持细胞胞质呈不规则的多处突起,细胞核呈圆形或椭圆形,细胞之间交织成网状;免疫荧光Vimentin特异性表达鉴定显示,所分离培养的细胞为睾丸支持细胞,经显微镜下计数其纯度达95%以上。结论:缩短两步酶消化时间,培养24h后用预冷磷酸盐缓冲溶液(PBS)洗换培养液,连续传代培养至第三代,此方法简化了分离培养支持细胞步骤,同时提高了支持细胞的纯度和细胞数量。     

一种D-π-A构型的三苯胺衍生物的合成及细胞成像应用

以三苯胺和吲哚作为原料,设计合成了一种具有D-π-A构型的三苯胺衍生物L,借助核磁共振氢谱、碳谱、红外光谱和质谱对化合物L的结构进行了表征。结合理论计算,探究了化合物L的光学性质以及对外部干扰因素的稳定性,结果表明化合物L对常见氨基酸和离子具有良好的抗干扰能力。细胞毒性实验和激光共聚焦显微成像实验结果表明化合物L具有较低的细胞毒性和良好的生物相容性,能着色于细胞的细胞质部位。     

碳纳米管在药物载体领域的应用

医学中开发新型药物载体对研究药物具有重要作用,作为一种具有独特纳米管径与中空结构的碳纳米管,可将其纳入药物载体范畴,以核酸、蛋白、药物分子以及肽所修饰的新型碳纳米管为载体,将生物活性分子运载至细胞中,而且不会产生毒性。本研究主要对碳纳米管在药物载体领域的应用进行分析与探讨。     

羔羊大肠杆菌分离鉴定及其致病性、耐药表型和耐药基因检测

目的:对皖北地区羊养殖场中所采集的37份腹泻羔羊粪便样本进行病原菌的分离鉴定,并对其耐药性及耐药基因进行测定。方法:将采集样本进行病原菌分离鉴定并进行同源性分析,通过药敏试验测定分离菌药物敏感性并对其耐药基因进行检测。结果:试验分离细菌37株,经生长特性、生化鉴定及16S rRNA测序对比序列确定分离菌均为大肠杆菌。致病性检测大肠杆菌中有21株为产志贺毒素大肠杆菌,其中Stx-1毒力基因和Stx-Ⅱ毒力基因分别占比8.10%和48.65%,肠毒性大肠埃希杆菌在本次试验中未检出。对分离的大肠杆菌进行耐药基因检测,6组耐药基因中tetA(97.30%)和qnr(83.78%)检出率较高。药敏结果显示分离的大肠杆菌对复方新诺明和林可霉素的耐药率分别达到89.19%和94.59%。结论:皖北地区部分大肠杆菌存在致泻性、携带多种耐药基因、存在多重耐药情况。     

牛乳酪蛋白源ACE抑制肽的稳定性和毒理特性研究(英文)

研究目的:酸碱热处理对牛乳酪蛋白源血管紧张素转化酶(ACE)抑制肽的抑制活性、游离氨基、色泽及其毒理特性的影响。创新要点:在pH 9.0~12.0的热处理条件下,牛乳酪蛋白源ACE抑制肽的抑制活性降低,色泽加深。热处理后的ACE抑制肽对Caco-2细胞和ECV-304细胞没有毒性作用。研究方法:以ACE抑制活性、游离氨基、色差值和细胞存活率为检测指标,研究了酸碱热处理对ACE抑制肽的稳定性和毒理特性影响。重要结论:高温和碱性热处理能破坏酪蛋白源ACE抑制肽的稳定性。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.