全文获取类型
收费全文 | 8459篇 |
免费 | 424篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 158篇 |
儿科学 | 498篇 |
妇产科学 | 175篇 |
基础医学 | 748篇 |
口腔科学 | 120篇 |
临床医学 | 471篇 |
内科学 | 1652篇 |
皮肤病学 | 238篇 |
神经病学 | 706篇 |
特种医学 | 277篇 |
外科学 | 1483篇 |
综合类 | 321篇 |
一般理论 | 1篇 |
预防医学 | 405篇 |
眼科学 | 336篇 |
药学 | 568篇 |
中国医学 | 25篇 |
肿瘤学 | 714篇 |
出版年
2023年 | 39篇 |
2022年 | 86篇 |
2021年 | 218篇 |
2020年 | 146篇 |
2019年 | 178篇 |
2018年 | 221篇 |
2017年 | 138篇 |
2016年 | 190篇 |
2015年 | 173篇 |
2014年 | 317篇 |
2013年 | 401篇 |
2012年 | 584篇 |
2011年 | 626篇 |
2010年 | 356篇 |
2009年 | 318篇 |
2008年 | 505篇 |
2007年 | 534篇 |
2006年 | 510篇 |
2005年 | 438篇 |
2004年 | 395篇 |
2003年 | 363篇 |
2002年 | 285篇 |
2001年 | 153篇 |
2000年 | 171篇 |
1999年 | 158篇 |
1998年 | 73篇 |
1997年 | 75篇 |
1996年 | 67篇 |
1995年 | 43篇 |
1994年 | 33篇 |
1993年 | 33篇 |
1992年 | 61篇 |
1991年 | 58篇 |
1990年 | 51篇 |
1989年 | 57篇 |
1988年 | 45篇 |
1987年 | 63篇 |
1986年 | 53篇 |
1985年 | 58篇 |
1984年 | 58篇 |
1983年 | 36篇 |
1978年 | 29篇 |
1977年 | 30篇 |
1974年 | 34篇 |
1973年 | 49篇 |
1972年 | 42篇 |
1971年 | 37篇 |
1970年 | 30篇 |
1969年 | 35篇 |
1968年 | 36篇 |
排序方式: 共有8896条查询结果,搜索用时 812 毫秒
51.
52.
53.
The cytologic appearance of epithelioid sarcoma in fine-needle aspiration biopsy cytology (FNABC) smears has not been extensively described. We report a case of epithelioid sarcoma in a 55-year-old male who presented with nodular swellings in the abdominal wall and scrotum. The scrotal swelling was subsequently demonstrated to arise from the vas deferens. We highlight the cytomorphologic, immunocytochemical, and histopathologic features of this rare lesion in an unusual site, with particular emphasis on the dilemma encountered in the cytodiagnosis of this lesion. 相似文献
54.
55.
Cell-based bioassays have been suggested for screening of hormones and drug bioactivities. They are a plausible alternative
to animal based methods. The technique used is called receptor/reporter system. Receptor/reporter system was initially developed
as a research technique to understand gene function. Often reporter constructs containing viral promoters were used because
they could be expressed with very 'high' magnitude in a variety of cell types in the laboratory. On the other hand mammalian
genes are expressed in a cell/tissue specific manner, which makes them (i.e. cells/tissues) specialized for specific function in vivo. Therefore, if the receptor/reporter system is to be used as a cell-based screen for testing of hormones and drugs for human
therapy then the choice of cell line as well as the promoter in the reporter module is of prime importance so as to get a
realistic measure of the bioactivities of 'test' compounds. We evaluated two conventionally used viral promoters and a natural
mammalian promoter, regulated by steroid hormone progesterone, in a cell-based receptor/reporter system. The promoters were
spliced into vectors expressing enzyme CAT (chloramphenicol acetyl transferase), which served as a reporter of their magnitudes
and consistencies in controlling gene expressions. They were introduced into breast cell lines T47D and MCF-7, which served
as a cell-based source of progesterone receptors. The yardstick of their reliability was highest magnitude as well as consistency
in CAT expression on induction by sequential doses of progesterone. All the promoters responded to induction by progesterone
doses ranging from 10-12 to 10-6 molar by expressing CAT enzyme, albeit with varying magnitudes and consistencies. The natural mammalian promoter showed the
most coherence in magnitude as well as dose dependent expression profile in both the cell lines. Our study casts doubts on
use of viral promoters in a cell-based bioassay for measuring bioactivities of drugs and hormones for human therapy and suggests
caution regardingtranslation in toto, of a research technique as a cell-based bioassay for drug screening. 相似文献
56.
57.
Bhattacharya SK Singh NK Prasad RC Sinha PR 《The Journal of the Association of Physicians of India》1998,46(8):675-677
Thirty four patients aged 14 to 65 years (18 males and 16 females) admitted to the University Hospital with various unusual and severe forms of adverse drug reactions were studied. It comprised of toxic epidermal necrolysis in 8 patients, systemic vasculitis in 7 of which 3 patients had gangrene of fingers and/or toes, severe erosive gastritis in 9 patients, Stevens-Johnson syndrome in 7 patients, thrombocytopenic purpura in 2 patients and generalised convulsions in 1 patient. Various drugs responsible for causing these adverse drug reactions included antibacterials, antimalarials, anticonvulsants, antituberculars and nonsteroidal anti-inflammatory drugs. Most of the patients recovered. However, 5 of the 8 patients having toxic epidermal necrolysis died of which 2 patients had developed tetanus as a preterminal event. In view of ongoing addition of newer drugs to the therapeutic armamentarium and an increasing incidence of various unusual and severe forms of adverse drug reactions, it is our contention that a separate adverse drug reaction monitoring cell should be established in every hospital setting. 相似文献
58.
J. N. Sinha S. Gurtu D. K. Sharma K. P. Bhargava 《Naunyn-Schmiedeberg's archives of pharmacology》1985,330(3):163-168
Summary Microinjection of noradrenaline and clonidine into lateral medullary pressor area (LMPA) of chloralose anaesthetized cats produced dose dependent decrease in blood pressure without affecting heart rate, while phenylephrine did not elicit any cardiovascular response. Selective
2-adrenoceptor, antagonists idazoxan and piperoxan, microinjected locally, blocked the effects of the agonists but prazosin and phenoxybenzamine, which are relatively selective for
1-adrenoceptors, failed to do so. Clonidine did not elicit any response in guanethidine pretreated cats but noradrenaline microinjected into LMPA of these animals induced a pressor response which was blocked by prazosin pretreatment. It is concluded that catecholaminergic fibres impinging upon this are inhibit the activity of the inhibitory second order baroreceptor neurone by activating
1-adrenoceptors while
2-adrenoceptors situated presynaptically on these inhibitory catecholaminergic nerve terminals are responsible for the manifestation of the hypotensive effect of clonidine and exogenously administered noradrenaline. 相似文献
59.
J. N. Sinha D. K. Sharma S. Gurtu K. K. Pant K. P. Bhargava 《Naunyn-Schmiedeberg's archives of pharmacology》1984,326(3):193-197
Summary The Bezold-Jarisch reflex characterized by hypotension and bradycardia was elicited in anaesthetized artificially respired dogs (pretreated with a beta-adrenoceptor antagonist) using capsaicin 10 g/kg (i.v.). Intracisternal administration of the highly selective clonidine-like alpha2 adrenoceptor agonists B-HT 920 (10 g/kg) or B-HT 933 (30 g/kg) significantly facilitated this reflex bradycardia. The involvement of central alpha2-adrenoceptors is suggested as intracisternal administration of the alpha2 adrenoceptor blocking drugs yohimbine (50 g/kg) and piperoxan (50 g/kg) antagonized this facilitation. B-HT 920 also facilitated the vagally mediated baroreceptor reflex to the hypertensive effect of intravenous noradrenaline (3 g/kg). Although the Bezold-Jarisch reflex and the baroreceptor reflex have different afferent pathways, both reflexes may either converge into a common pathway or have separate neuronal chains within the medulla; however, this study indicates that both have a similar central modulatory system stimulated by alpha2 adrenoceptors. 相似文献
60.