全文获取类型
收费全文 | 53979篇 |
免费 | 3502篇 |
国内免费 | 1193篇 |
专业分类
耳鼻咽喉 | 315篇 |
儿科学 | 836篇 |
妇产科学 | 467篇 |
基础医学 | 6362篇 |
口腔科学 | 1199篇 |
临床医学 | 5215篇 |
内科学 | 5786篇 |
皮肤病学 | 342篇 |
神经病学 | 4610篇 |
特种医学 | 1793篇 |
外国民族医学 | 2篇 |
外科学 | 2465篇 |
综合类 | 4806篇 |
现状与发展 | 3篇 |
预防医学 | 6697篇 |
眼科学 | 210篇 |
药学 | 11719篇 |
41篇 | |
中国医学 | 4089篇 |
肿瘤学 | 1717篇 |
出版年
2024年 | 160篇 |
2023年 | 811篇 |
2022年 | 1685篇 |
2021年 | 2113篇 |
2020年 | 1873篇 |
2019年 | 1846篇 |
2018年 | 1797篇 |
2017年 | 1791篇 |
2016年 | 1745篇 |
2015年 | 1637篇 |
2014年 | 3035篇 |
2013年 | 4230篇 |
2012年 | 2623篇 |
2011年 | 3112篇 |
2010年 | 2177篇 |
2009年 | 2455篇 |
2008年 | 2402篇 |
2007年 | 2329篇 |
2006年 | 1931篇 |
2005年 | 1684篇 |
2004年 | 1434篇 |
2003年 | 1304篇 |
2002年 | 1084篇 |
2001年 | 1028篇 |
2000年 | 807篇 |
1999年 | 798篇 |
1998年 | 804篇 |
1997年 | 711篇 |
1996年 | 672篇 |
1995年 | 629篇 |
1994年 | 555篇 |
1993年 | 529篇 |
1992年 | 538篇 |
1991年 | 488篇 |
1990年 | 446篇 |
1989年 | 455篇 |
1988年 | 416篇 |
1987年 | 395篇 |
1986年 | 385篇 |
1985年 | 518篇 |
1984年 | 471篇 |
1983年 | 328篇 |
1982年 | 425篇 |
1981年 | 328篇 |
1980年 | 330篇 |
1979年 | 264篇 |
1978年 | 257篇 |
1977年 | 193篇 |
1976年 | 224篇 |
1975年 | 99篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Riccardo Torta Carlotta Berra Luca Binaschi Roberto Borio 《Supportive care in cancer》2007,15(5):539-546
Introduction Amisulpride is a substituted benzamide that, at low doses, selectively blocks D2 and D3 presynaptic dopamine receptors, enhancing
dopaminergic transmission in frontal cortex and limbic areas. Many clinical studies versus placebo, tricyclic antidepressants
and selective serotonin reuptake inhibitors showed amisulpride antidepressant effect, supporting its safety and rapid onset
of action. In oncological population, depression is quite frequent and difficult to treat because of the particular sensitivity
of cancer patients to the antidepressants’ side effects.
Goals of work The aims of this study were to evaluate efficacy, safety and tolerability of low doses of amisulpride (50 mg) in oncological,
depressed patients during chemotheraphy.
Materials and methods One hundred six consecutive cancer outpatients with depressive symptoms were treated in a prospective, intention to treat,
4-week study, and were evaluated in single-blind with Montgomery Asberg rating scale for depression (MADRS), clinical global
impression (CGI) and dosage record treatment emergent symptom scale (DOTES) to assess side effects of treatment.
Main results After 4 weeks of treatment, scores of MADRS and CGI significantly improved (p < 0.002; p < 0.001, respectively), with a reduction of depressive symptoms concerning both emotional (such as apparent sadness, reported
sadness, inner tension, etc.) and physical cluster (such as lack of appetite, reduction in weight, tiredness and insomnia)
with good tolerability (only two patients dropped out).
Conclusions This study is the first trial on the use of amisulpride in a cohort of oncological, depressed patients during chemotherapy.
Amisulpride demonstrated high efficacy and safety. Controlled studies are needed to confirm these preliminary data. 相似文献
23.
Robert M. Levy Roman Saikovsky Evgeniya Shmidt Alexander Khokhlov Bruce P. Burnett 《Nutrition Research》2009
Flavocoxid (Limbrel), a proprietary mixture of flavonoid molecules (baicalin and catechin), was tested against a traditional nonsteroidal anti-inflammatory drug, naproxen, for the management of the signs and symptoms of moderate osteoarthritis (OA) in humans. Discomfort and global disease activity were used as the primary end points, and safety assessments were also taken for both treatments as a secondary endpoint. In this double-blind study, 103 subjects were randomly assigned to receive either flavocoxid [500 mg twice daily (BID)] or naproxen (500 mg BID) in a 1-month onset of action trial. Outcome measures included the short Western Ontario and McMaster University Osteoarthritis Index, subject Visual Analogue Scale for discomfort and global response, and investigator Visual Analogue Scale for global response and fecal occult blood. Both flavocoxid and naproxen showed significant reduction in the signs and symptoms of knee OA (P ≤ .001). There were no statistically detectable differences between the flavocoxid and naproxen groups with respect to any of the outcome variables. Similarly, there were no statistically detectable differences between the groups with respect to any adverse event, although there was a trend toward a higher incidence of edema and nonspecific musculoskeletal discomfort in the naproxen group. In this short-term pilot study, flavocoxid was as effective as naproxen in controlling the signs and symptoms of OA of the knee and would present a safe and effective option for those individuals on traditional nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors. A low incidence of adverse events was reported for both groups. 相似文献
24.
Rainer Cammann Ariane Miehlke 《Journal of child psychology and psychiatry, and allied disciplines》1989,30(6):899-906
All non-task-related body movements during school hours were listed in 11 normally active and 12 hyperactive boys. The mean number of movements was 48 +/- 7 per 45 minutes in the normal actives and 79 +/- 16 per 45 minutes in the hyperactives. The rather monotonous increment and decrement of motor activity during the 4-hr registration period was noticed only in hyperactive boys. These results could be a consequence of a circadian rhythm, as there was independence of type of school hours and of teacher personality. The cyclical level of activity in hyperactive boys was sometimes in the range of the normal actives. 相似文献
25.
Aoyama Takao Yamamoto Koujirou Kotaki Hajime Sawada Yasufumi Iga Tatsuji 《Pharmaceutical research》1997,14(11):1601-1606
Purpose. The locomotive activity changes after intravenous (i.v.) administration of methylphenidate (MPD) in rats were pharmacodynamically analyzed.
Methods. MPD concentration in plasma, MPD concentration and dopamine (DA) level in striatal dialysate collected by microdialysis method, and the locomotor activity after i.v. administration of MPD (2, 5 and 10 mg/kg doses) were used for the analysis.
Results. The transport of MPD from plasma to the interstitial fluid in the brain could be expressed by the linear two-compartment model. The clockwise hysteresis between the MPD concentration and the DA level in the dialysate could be explained by the pharmacodynamic model considering Michaelis-Menten type reuptake process of the extracellular DA into the terminal of the dopaminergic nerve and its competitive inhibition by the extracellular MPD. The inhibition constant (Ki) of MPD for DA reuptake was estimated to be 41.3 ± 73.8 nM (mean ± SE), which was closely consistent with the in vitro value after correction with dialysis recovery. The relationship between DA level in dialysate and locomotor activity was expressed by the Emax model considering two contrary effects, hyperkinesia and stereotypy. The bi-phasic locomotor activity-time profiles after high dose of MPD could be represented by this model.
Conclusions. The developed model made it possible to explain the tolerance in DA increase and the complicated locomotive change induced by MPD, and may be useful for other DA reuptake inhibitors, such as amphetamine and methamphetamine. 相似文献
26.
Summary Two cases of meningiomas, which are considered to have been caused by the preceding irradiation, are reported. In both cases, the cytokinetic study of the tumour using bromodeoxyuridine (BrdU) was performed. The percent of the tumour cells in the S phase of the cell cycle was less than 1% in both cases. The low labelling indices might suggest a relatively slow growing potential of these tumours, though the radiation-induced meningiomas were reported as being rapidly growing and malignant. 相似文献
27.
In the present study, chlorogenic acid (CGA) isolated from Anthocephalus cadamba was screened for hepatoprotective activity by in vitro and in vivo assay methods using carbon tetrachloride (CCl4) as a model of liver injury. Intraperitoneal administration of CGA to mice at a dose of 100 mg/kg body weight for 8 days caused significant reversal in lipid peroxidation, enzymatic leakage, cytochrome P450 (Cyt P450) inactivation and produced enhancement of cellular antioxidant defence in CCl4-intoxicated mice, revealing that the antioxidative action of CGA is responsible for its liver protective activity. CGA exhibited a better therapeutic protective action than silymarin (SM), in CCl4-administered mice. 相似文献
28.
R. Alan Aitken Michael C. Bibby John A. Double Andrea L. Laws Robert B. Ritchie David W. J. Wilson 《Archiv der Pharmazie》1997,330(7):215-224
A range of 18 derivatives of flavone-8-acetic acid (FAA) with substituents on the 2-phenyl group have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. There was no clear-cut relationship between in vitro and in vivo activity but the activity in each situation was found to be very sensitive to the precise substitution pattern with closely related isomers giving widely different activities. Some of the compounds, notably 10b,cj , and r , were active in vivo and these require further studies in order to evaluate their potential for development. 相似文献
29.
Stanislw Ryng Zdzislw Machn Zbigniew Wieczorek Michal Zimecki Tadeusz Glowiak 《Archiv der Pharmazie》1997,330(11):319-326
A series of 5-aminomethinimino-3-methyl-4-isoxazolecarboxylic acid phenylamides 4 has been prepared by condensation of 5-amino-3-methyl-4-isoxazolecarboxylic acid phenylamides 1 with trichloroacetic aldehyde. Alcoholysis of trichloro derivatives 2 gave 5-alkoxymethine derivatives 3 which, on reaction with an appropriate amine, formed the corresponding compounds 4 . The compounds obtained were evaluated for their immunological activity. The properties of three compounds, described in this report, permitted inhibition of the immune response in all possible ways: diminishing both types of immune response ( 4d ), humoral immune response ( 4a ), or cellular immune response ( 4c ). Preparation 4d is comparable in its effectiveness to CsA, so it may be potentially used as an agent for prolongation of the function of transplanted organs. Two other compounds may potentially be used in cases where only one type the immune response is required for combating pathogen invasion. 相似文献
30.
Nicoletta Desideri Isabella Sestili Maria Luisa Stein Stefano Manarini Giuseppe Dell'Elba Chiara Cerletti 《Archiv der Pharmazie》1997,330(4):100-106
6-[(4-Quinolinyl)oxy]hexanoic acids and the corresponding esters were designed and synthesized as inhibitors of the production of arachidonic acid metabolites. The inhibitory activities were assayed in vitro by evaluation of serum leukotriene B4 and thromboxane B2 production. While all 6-[(4-quinolinyl)oxy]hexanoic acids and their esters proved to be inactive, the N-alkyl-4-quinolones, obtained as by-products in their synthesis, were found to be a new class of leukotriene biosynthesis inhibitors. 相似文献