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1.
The aim of the study was to determine the effect of exogenous melatonin treatment on circulating prolactin levels in red deer. Melatonin was administered from 12 June 1984 (day 1) to lactating and non-lactating hinds in the feed daily at 1600 h, and to non-lactating hinds by a subcutaneous implant. Average concentrations (ng/ml) of prolactin in plasma taken serially over 15-h periods were significantly higher for untreated hinds than for melatonin-treated animals on day 15 whether lactating (66-133 v. 23-28, P less than 0.05) or non-lactating (28-174 v. 8-13, P less than 0.01), remained higher on day 36 (lactating: 41-152 v. 15-21, P less than 0.05; non-lactating: 21-50 v. 1-7, P less than 0.001) but had decreased to similar levels on day 72 (lactating: 5-24 v. 7-17; non-lactating: 2-9 v. 0-4). The advanced reduction in plasma prolactin for all melatonin-treated hinds was associated with an advanced onset of seasonal breeding activity.  相似文献   
2.
Occupational airborne allergic contact dermatitis from tylosin   总被引:2,自引:1,他引:1  
  相似文献   
3.
采用文献考证与实地调查相结合的方法,对常用藏药材"蒂达"的名称、品种分类及其基原进行了考证和整理.结果表明,"蒂达"的名称、品种和基原极为复杂混乱,是导致其缺乏和难以制定药材质量控制标准的关键制约因素.类似状况在民族药中普遍存在,反映出了对民族药进行品种整理的必要性和迫切性.由于古代文献对于药物基原的形态描述往往较为简单,多数情况下仅根据文献考证难以准确确定其基原,在进行民族药品种整理时,还应"尊古不泥古",注重古今药材品种、基原的历史变迁和现实资源、临床使用状况的调查,并积极借鉴现代化学、生物活性评价等的研究成果,既继承民族医药的特色与优势,又推动其现代化发展.  相似文献   
4.
从桑椹成熟果实、桑叶以及桑果园的土壤采样,进行桑椹果酒专用酵母的筛选,得到一株在性能上优于对照菌葡萄酒干酵母的酵母菌Y11。该菌起酵快,从第2天开始糖度大幅度下降,酒精度快速上升,发酵第4天酒精体积分数即可达到10%以上。发酵过程pH值变化趋势比较平缓,发酵结束后高级醇量符合要求。综合发酵性能及感官评定,表明该菌能代替葡萄酒干酵母用于桑椹果酒的生产。  相似文献   
5.
丹霞地貌生境中铁皮石斛的繁殖生物学研究   总被引:2,自引:0,他引:2  
目的:揭示丹霞地貌生境中铁皮石斛的繁育系统及濒危机制.方法:对该地区铁皮石斛的生境、生长特性、开花物候、繁殖特性以及资源破坏状况等进行了调查.结果:丹霞地貌铁皮石斛生长环境恶劣,春季为其生长高峰;2~3年生茎开花,花后及时授粉,结实率较高;授粉后4~5 d子房开始膨大,果实成熟期为185 d左右;自然有性繁殖的结实率(0.31%)极低;无性克隆繁殖1丛仅1年生1茎.结论:丹霞地貌生境下铁皮石斛群体自然更新主要是通过分蘖繁殖实现的;人为掠夺性采集是该地区铁皮石斛野生资源濒危的主要因素.  相似文献   
6.
阿弗菌素产生菌SIPI-AV-99081的选育   总被引:1,自引:0,他引:1  
阿弗菌素链霉菌SIPI-AV-99081采用UV和NTG进行诱变处理。选育得到一高产菌株和几个典型的突变株。高产菌株AV-h-360的阿弗菌素B1的生产能力较出发菌株提高了3倍,AV-m-486和AV-m-796为阿弗菌素合成阻断突变株,它们都不能产生天然的阿弗菌素。  相似文献   
7.
Donkeys, an endangered species, have recently gained a new application with the use of their milk to feed humans with allergic processes. The Ragusana donkey breed from Sicily is used to produce milk for humans with allergic diseases. In order to evaluate the hygienic, nutritional and management measures on a farm of Ragusana donkeys, complete blood counts, extended biochemical profiles and serum protein electrophoresis, as part of metabolic profile test (MPT), were performed in Ragusana donkeys. Fifty-four donkeys were studied and grouped according to their age, (1) 29 females and a single stallion (n=30), (2) young females, 1 – 3 years old (n=10) and (3) young of both sexes under 1 year old (n=14). The RBC count, RDW value, Lymp, and Mono counts, and PDW values were statistically greater in donkeys under one year old than in adult donkeys, while the Seg Neu count was lower. The CPK, ALP, iPhos, and HCO3, values were statistically higher in the group of donkeys under 1 year of age than adult donkeys while Cl and LDH values were statistically lower in donkeys under 1 year than adult donkeys. Additionally, statistically significant increased values for CPK, ALP, Alb, Chol, iPhos, HCO3, and UIBC in young donkeys under 1 year when compared with young donkeys, 1 – 3 years were observed. A statistically significant decreased value for Urea and an increased value for Crea in young donkeys, 1 – 3 years old were found as compared to adults. The serum protein fractions recognised by electrophoresis were: albumin, alpha globulin (subdivided into alpha-1 and alpha-2-globulins), beta globulin, and gamma globulin. In the alpha-1-globulin region three small peaks were constantly noticed, and alpha-2-globulins were statistically different between the three groups being greater in young donkeys under 1 year of age. The results obtained were used both to establish reference ranges and a data bank for the farm of Ragusana donkeys for future needs in assessing the metabolic status and health of the animals.  相似文献   
8.
Adolescent and adult rats exhibit at least two distinct ultrasonic vocalizations that reflect distinct emotional states. Rats exhibit 22-kHz calls during social defeat, drug withdrawal, as well as in anticipation of aversive events. In contrast, 50-kHz calls are exhibited in high rates during play behavior, mating, as well as in anticipation of rewarding events. The neurochemistry of 22-kHz and 50-kHz calls closely matches that of negative and positive emotional systems in humans, respectively. The aim of this study was to replicate and further evaluate selective breeding for 50-kHz vocalization, in preparation for the analysis of the genetic underpinnings of the 50-kHz ultrasonic vocalization (USV). Isolate housed adolescent rats (23–26 days old) received experimenter administered tactile stimulation (dubbed tickling), which mimicked the rat rough-and-tumble play behavior. This stimulation has previously been shown to elicit high levels of 50-kHz USVs and to be highly rewarding in isolate-housed animals. Each tickling session consisted of 4 cycles of 15 seconds stimulation followed by 15 seconds no stimulation for a total of 2 min, and was repeated once per day across 4 successive days. Rats were then selected for either High or Low levels of sonographically verified 50-kHz USVs in response to the stimulation, and a randomly selected line served as a control (Random group). Animals emitted both 22-kHz and 50-kHz types of calls. After 5 generations, animals in the High Line exhibited significantly more 50-kHz and fewer 22-kHz USVs than animals in the Low Line. Animals selected for low levels of 50-kHz calls showed marginally more 22-kHz USVs then randomly selected animals but did not differ in the rate of 50-kHz calls. These results extend our previous findings that laboratory rats could be bred for differential rates of sonographically verified 50-kHz USVs.  相似文献   
9.
目的综述DNA改组技术的发展及其在生物药学领域的应用,为生物药学及其相关领域的研究和进一步应用提供参考。方法总结、分析近几年来相关方面的文献资料。结果及结论DNA改组是一种有效的在体外利用重组技术加速基因进化的定向分子进化过程,它可以使单一基因和多基因靶序列进行多次重组和筛选而使其快速进化。DNA改组技术发展迅速并广泛应用于酶的改良、药物蛋白优化、疫苗改进等领域,具有广阔应用发展前景。  相似文献   
10.
泡桐刨花用作实验小鼠垫料的研究   总被引:5,自引:0,他引:5  
泡桐茎高大 ,通气组织蓬松 ,富含纤维。测定 4 8h吸水量 ,每克泡桐刨花吸水 3.31± 0 .2 4g ,椴木刨花吸水 3.4 2± 0 .18g ,两者差异无显著性 (P >0 .0 5)。但高于玉米棒芯吸水量 2 .4 3± 0 .17g(P <0 .0 5)。不同年龄小鼠 (指孕鼠、乳鼠、青年鼠 )对泡桐刨花垫料的适应性均较好 ,生长发育和繁殖良好。以泡桐刨花作垫料 ,饲养的KM小鼠在 6个月和 12个月时 ,活体骨髓多染性红细胞微核率分别为 ( 3.2 6± 0 .37)‰和( 3.60± 0 .4 5)‰ ,均在正常范围之内。表明泡桐刨花垫料没有致畸作用。  相似文献   
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