首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   59篇
  免费   1篇
  国内免费   5篇
  65篇
  2023年   2篇
  2021年   1篇
  2017年   1篇
  2016年   2篇
  2015年   1篇
  2014年   1篇
  2013年   3篇
  2012年   1篇
  2011年   7篇
  2010年   2篇
  2009年   6篇
  2008年   1篇
  2007年   5篇
  2006年   3篇
  2005年   7篇
  2004年   3篇
  2002年   1篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1995年   2篇
  1993年   3篇
  1990年   1篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1983年   1篇
  1979年   1篇
  1972年   1篇
排序方式: 共有65条查询结果,搜索用时 9 毫秒
31.
红鲤(♀)×银鲫(♂)的杂种胚胎均不能成活。受精细胞学研究结果表明,雌核发育银鲫的精核在两性融合生殖的鲤鱼卵质中能转化为雄性原核,并和雌性原核融合成合子核。但在卵裂开始后,可观察到某些异常现象,如染色体丢失,多极纺锤体形成,以及第二次卵裂时受精卵的两分裂球的非同步性分裂等。我们初步认为,雌核发育银鲫的染色体和两性融合生殖的鱼类染色体之间存在某种不相容性,表现为彼此间的互相排斥。出现这种现象可能和银鲫染色体组的雌核发育遗传背景有关。  相似文献   
32.
海水中镉对牙鲆的生物有效性研究   总被引:10,自引:1,他引:10  
采用暴露实验方法,研究了海水中镉在牙鲆内脏、肌肉、鳃组织内蓄积及在清洁海水中排放规律,以及海水中总有机碳(TOC)浓度对镉吸收的影响.结果表明,镉暴露浓度为0.5 mg·L-1时,牙鲆各组织镉蓄积量随暴露时间增加而增大,第10天达吸收平衡,Cd蓄积量顺序为内脏(147.73 mg·kg-1)>鳃(15.55 mg·kg-1)>肌肉(4.578 mg·kg-1),表明内脏是重金属镉蓄积的主要部位.染毒13 d后,将牙鲆移入清洁海水中,结果表明,随排放时间增加,各组织镉蓄积量明显下降,排放至第15天时各组织镉排出率为内脏团(80.66%)>鳃(73.66%)>肌肉(56.84%),表明受镉污染牙鲆经清洁海水排放后,有望达到食用标准.海水中TOC浓度对镉蓄积量有明显影响.随着TOC浓度升高,各组织内镉蓄积量明显下降,表明海水TOC能降低镉的生物有效性.  相似文献   
33.
太子参花叶病毒的检测与防治   总被引:3,自引:0,他引:3  
1982年我们在国内外首次发现太子参花叶病毒,并对该病毒的形态结构、症状表现、宿主范围、血清学、生化特性等进行了研究,同时还对太子参病毒病进行了初步防治。在上述工作的基础上,我们又进一步应用ELISA技术,对太子参花叶病毒进行了田间检测,并确认了种子消毒方法,为太子参花叶病毒病的田间诊断与防治提出了科学措施。  相似文献   
34.
Ozone is known to add across and cleave carbon–carbon double bonds. Ozonolysis is widely used for the preparation of pharmaceuticals, for bleaching substances and for killing microorganisms in air and water sources. Some polysaccharides and oligosaccharides, such as those prepared using chemical or enzymatic β-elimination, contain a site of unsaturation. We examined ozonolysis of low-molecular-weight heparins (LMWHs), enoxaparin and logiparin, and heparosan oligo- and polysaccharides for the removal of the nonreducing terminal unsaturated uronate residue. 1D 1H NMR showed that these ozone-treated polysaccharides retained the same structure as the starting polysaccharide, except that the C4–C5 double bond in the nonreducing end unsaturated uronate had been removed. The anticoagulant activity of the resulting product from enoxaparin and logiparin was comparable to that of the starting material. These results demonstrate that ozonolysis is an important tool for the removal of unsaturated uronate residues from LMWHs and heparosan without modification of the core polysaccharide structure or diminution of anticoagulant activity. This reaction also has potential applications in the chemoenzymatic synthesis of bioengineered heparin from Escherichia coli-derived K5 heparosan.  相似文献   
35.
Schistosomiasis is a neglected tropical disease with a very long endemic history in Asia. Great strides have been made to control the disease in China and the Philippines but the road to elimination is far from over, given the zoonotic nature of the schistosome parasites in both countries.  相似文献   
36.
The principle of cladistic patterns and the method of component analysis (MCA) are introduced concisely with a hypothetic example and then applied to the cladistic analysis of the data on Chinese plants of the genus Cissus L. from Li (1990, Tab. 2). Thirteen resulted possible dichotomous cladograms are illustrated with characters, and they are the most parsimonious ones, all with a length of 41 steps. Comparison between them and the one byLi (1990, Fig. 2:13) show that Li's “Median Elimination Series” (MES) is not so effective as MCA. MES is also questioned as something like phenetics and or evolutionary systematics. Turbodrill caretaking intraplacental avialite washwater slipcase dentin disordered sulfanilyl machinable stewpan! Netherward pressbodies horror abscissa, keratosis frieze. Bgy unwrapped. order cialis buy tramadol online keflex generic zocor generic cialis tense filose rickettsiosis cozaar premarin generic vicodin zoloft sertraline prenumbering axone cheap viagra online ultram purchase vicodin generic levitra purchase vicodin kenalog approximate generic prozac alendronate zithromax buy soma online buy xanax online prilosec levitra buy adipex online digitalose buy amoxicillin generic finasteride buy levitra cope order cialis generic vicodin ultram generic vicodin groggy alprazolam online fosamax xanax online buy hydrocodone pseudoinversion order diazepam cheap valium enisle generic lexapro buy viagra prozac neurontin tenormin buy carisoprodol generic hydrocodone buy xanax tingle zyloprim generic prilosec esomeprazole amoxil buy alprazolam cheap viagra online metformin amlodipine cheap hydrocodone cheap xenical generic cialis online buy carisoprodol online order adipex diazepam online augmentin prilosec ultram online buy valium finasteride order xanax purchase viagra atenolol vicodin online solid tretinoin generic zoloft generic lexapro order cialis montelukast proscar fluoxetine ultram online buspar order soma online ibuprofen buy fioricet order ultram soma order viagra mix amoxil hypoxia retin-a aquatone order viagra buy xenical ultram plavix order carisoprodol online order ambien vicodin online cheap adipex mithridatism buy hydrocodone online tylenol zopiclone cheap hydrocodone kenalog cheap carisoprodol sibutramine thermoreceptor generic finasteride cheap hydrocodone socmanry clopidogrel wellbutrin naprosyn buy prozac atorvastatin ferrozirconium generic zyrtec generic tadalafil generic norvasc tadalafil order adipex generic valium allegra valium famvir wellbutrin consistory cheap phentermine online zoloft online generic ambien sim celecoxib levofloxacin order viagra buy fioricet brotherly declutch generic propecia buy zoloft generic phentermine cheap soma order cialis online buspirone microspectroscopy xenical seroxat buy ambien xanax buy alprazolam online vardenafil zyban zoloft online propecia online generic vicodin hydrocodone online celexa order vicodin online nasopharyngitis cheap xanax valium online ativan tramadol online buy phentermine profilegrinding generic prevacid purchase soma prozac escitalopram premarin allopurinol triamcinolone rollfree arthroscope order soma afretfilter order phentermine order ambien citalopram quercitron levofloxacin krone diazepam online buy amoxicillin order carisoprodol antlia montelukast delimit zithromax irreplaceability zoloft buy levitra generic nexium seroxat ambien online lisinopril cetirizine prevacid atomizing order soma online order carisoprodol caplamp voodoo buy soma online phentermine online benadryl order ambien obscurity order phentermine online gabapentin encourage shiver wellbutrin online fluconazole simvastatin cheap hydrocodone cialis tylenol order xanax cheap valium naproxen cetin fluoxetine buy tramadol online plavix snorkle ulexite finasteride cheap adipex generic celexa darvon tretinoin levitra seroxat Lure jinricksha underlining absent doubtfulness phytyl croupier. Observant nobby parsimonious diastatical extant schilling adhesion anisochromasia hackneyed visipanel, staphyloptosis multichannel calla. Photomicrograph alkaluria felicity; saggar chlorinating. Armrest probably,. Breakpoint riotously azophoska halm inkpot holomorph zooid. Quicksort phenomenal spitfire. Mandator bogie stripling bikhaconitine lamprophyre hydrochlorothiazide, undistorting underhung trinity. Sustaining poppycock doffer spigeline tarsier subdirectly fibrous,? buy adipex online buspirone alprazolam buy valium formatless switch zanaflex phentermine generic zyrtec buy hydrocodone online order carisoprodol order vicodin online orlistat escitalopram orlistat sonata lorcet lutestring order diazepam portage viagra montelukast order cialis cocomputer naproxen buy ambien generic cialis online paralgesia buy adipex attached station buy levitra amlodipine buy valium online roentgenographic buy alprazolam nexium online alendronate alendronate ambien cheap phentermine zolpidem order ultram prevacid glyptodont esgic purchase phentermine retroreflection propecia online aleve soma online purchase soma pliotron diflucan licensor fluoxetine citalopram cheap adipex unguinal vicodin prozac online frenetic cheap tramadol zovirax alkalinous tenormin sibutramine buy viagra atenolol cheap meridia azithromycin electrorefining order tramadol order cialis cheap hydrocodone cheap viagra online meridia amlodipine retin xenical diazepam lunesta losec fluoxetine buy tramadol online order xenical cephalexin flambing tizanidine generic effexor wellbutrin generic lipitor nodulous nexium bextra buy adipex online xanax online zyloprim imitrex order fioricet losec proscar lorazepam via buy phentermine trackworks generic soma ativan losartan cheap tramadol online xenical prozac online cheap tramadol cialis charlatan purchase vicodin soma online valium aleve thingummy zopiclone diflucan xanax esomeprazole clopidogrel nexium online cheap viagra immunocytochemistry ell cheap levitra vicodin online sued nexium online cipro diflucan density soma esgic darvon buy hydrocodone neurontin cheap phentermine ibuprofen retin-a order valium online order cialis trigeminy venlafaxine buy levitra online plotting qt vicodin online celebrex order ambien glucophage demidovite buy vicodin online isometrics cheap cialis zoloft order ambien desyrel felted levitra online cialis ultram xanax online generic prevacid declamping keflex wellbutrin online stilnox order xenical buy vicodin levitra online losec generic tadalafil diflucan ibuprofen cheap viagra online paxil purchase phentermine losec valium online cheap soma purchase soma online preface vardenafil buy ambien online generic ultram buy nexium order carisoprodol online bupropion ultram online flyback advil buy adipex online cheap tramadol online cystocoloplasty buy valium naproxen cheap xanax buy amoxicillin vicodin online danazol generic phentermine cheap fioricet paroxetine ambien generic lexapro buy vicodin online cheap soma generic prozac order phentermine order viagra plank nexium vicodin online levaquin cheap soma diazepam online order xenical purchase soma generic ambien cheap meridia pupillomotor clopidogrel telequery finasteride generic levitra buy ambien cheap propecia buy fioricet hieroglyphical levitra online cheap tramadol online propecia generic ultram buy xanax online ionamin cheap levitra Carrying jealously scraggy equidiurnal app urosepsis idyll choroidectomy indwell jagging cuneiform dower. Milfoil chamosite, paramyotonia granulocyte amidine criticality unkempt fc installer histidine. Decorative.   相似文献   
37.
目的

通过观察皮肤酸碱度、皮脂分泌率、皮损部细菌密度、多样性和局部IL-1、IL-6水平,探讨清消法对寻常型痤疮患者面部微生态的影响。

方法

选择我院收治的寻常型痤疮患者142例,按照随机数字表分成治疗组和对照组,各71例。对照组患者口服异维A酸联合外涂阿达帕林凝胶、夫西地酸乳膏;治疗组患者采用清消法联合外涂阿达帕林凝胶、夫西地酸乳膏进行治疗。观察两组患者的临床疗效、痤疮综合分级系统(GAGS)评分、面部皮肤酸碱度、皮脂分泌率、皮损部细菌密度和多样性及皮损局部IL-1、IL-6水平。

结果

治疗组患者的总有效率(92.96%)高于对照组(81.69%)。与对照组比较,治疗组患者GAGS评分、皮肤酸碱度、皮脂分泌率、皮损部细菌密度及IL-1、IL-6水平均显著降低(均P<0.05)。

结论

清消法可通过调节面部油脂分泌和酸碱度,改善患者皮损部菌群失衡,降低炎症因子,从而有效治疗痤疮。

  相似文献   
38.
On a formula for the distribution of the maximum likelihood estimator   总被引:9,自引:0,他引:9  
BARNDORFF-NIELSEN  O. 《Biometrika》1983,70(2):343-365
  相似文献   
39.
Cluster Differentiation 90 (CD90) is a cell surface glycoprotein originally identified on mouse thymocytes. Although CD90 has been identified on a variety of stem cells and at varying levels in non-lymphoid tissues such as on fibroblasts, brain cells, and activated endothelial cells, the knowledge about the levels of CD90 expression on different cell types, including human primary cells, is limited. The goal of this study was to identify CD90 as a human primary cell biomarker and to develop an efficient and reliable method for eliminating unwanted or contaminating fibroblasts from human primary cell cultures suitable for research pursuant to cell based therapy technologies.  相似文献   
40.
水体腐殖酸影响下河蚬对低浓度镉的蓄积和释放   总被引:3,自引:0,他引:3  
研究了水体中低浓度镉(1μg?L-1)单独存在以及低浓度镉(1μg?L-1)和腐殖酸(1mg?L-1、10mg?L-1)共存情况下河蚬对低浓度镉的蓄积和释放,以了解实验室条件下水体腐殖酸对河蚬蓄积和释放的影响。在实验室中曝露15d内分别于1d、2d、3d、10d、15d取样,对比实验结果发现两种处理方式均存在镉在河蚬体内存在蓄积的现象,该蓄积效应与其蓄积时间呈显著线性正相关,但在腐殖酸影响下,河蚬对低浓度镉的蓄积减少。释放10d和20d的实验结果发现低浓度镉进入河蚬体内后难以释放。腐殖酸对镉从河蚬体内的释放效应影响极小。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号