全文获取类型
收费全文 | 12321篇 |
免费 | 1754篇 |
国内免费 | 168篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 361篇 |
妇产科学 | 232篇 |
基础医学 | 1863篇 |
口腔科学 | 223篇 |
临床医学 | 1482篇 |
内科学 | 2478篇 |
皮肤病学 | 134篇 |
神经病学 | 1002篇 |
特种医学 | 753篇 |
外国民族医学 | 1篇 |
外科学 | 1509篇 |
综合类 | 616篇 |
一般理论 | 8篇 |
预防医学 | 1476篇 |
眼科学 | 184篇 |
药学 | 978篇 |
1篇 | |
中国医学 | 26篇 |
肿瘤学 | 712篇 |
出版年
2021年 | 129篇 |
2020年 | 115篇 |
2019年 | 188篇 |
2018年 | 250篇 |
2017年 | 166篇 |
2016年 | 149篇 |
2015年 | 190篇 |
2014年 | 250篇 |
2013年 | 385篇 |
2012年 | 564篇 |
2011年 | 573篇 |
2010年 | 314篇 |
2009年 | 304篇 |
2008年 | 494篇 |
2007年 | 571篇 |
2006年 | 479篇 |
2005年 | 476篇 |
2004年 | 472篇 |
2003年 | 450篇 |
2002年 | 429篇 |
2001年 | 406篇 |
2000年 | 469篇 |
1999年 | 388篇 |
1998年 | 266篇 |
1997年 | 196篇 |
1996年 | 212篇 |
1995年 | 203篇 |
1994年 | 179篇 |
1993年 | 166篇 |
1992年 | 293篇 |
1991年 | 318篇 |
1990年 | 268篇 |
1989年 | 342篇 |
1988年 | 269篇 |
1987年 | 294篇 |
1986年 | 259篇 |
1985年 | 259篇 |
1984年 | 239篇 |
1983年 | 196篇 |
1982年 | 183篇 |
1981年 | 117篇 |
1980年 | 91篇 |
1979年 | 181篇 |
1978年 | 128篇 |
1977年 | 131篇 |
1976年 | 128篇 |
1975年 | 82篇 |
1974年 | 102篇 |
1973年 | 98篇 |
1972年 | 80篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
P. von Dadelszen Gynaecology Registrar M. D. G. Gillmer Consultant Gynaecologist M. D. Gray Consultant Gynaecologist H. P. McEwan Consultant Gynaecologist R. J. D. Pyper Consultant Gynaecologist T. P. Rollason Consultant Pathologist A. Wright Gynaecology Registrar 《BJOG : an international journal of obstetrics and gynaecology》1994,101(2):158-161
42.
Effectiveness of training health professionals to provide smoking cessation interventions: systematic review of randomised controlled trials.
下载免费PDF全文
![点击此处可从《Quality in health care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
OBJECTIVE--To assess the effectiveness of interventions that train healthcare professionals in methods for improving the quality of care delivered to patients who smoke. DESIGN--Systematic literature review. SETTING--Primary care medical and dental practices in the United States and Canada. Patients were recruited opportunistically. SUBJECTS--878 healthcare professionals and 11,228 patients who smoked and were identified in eight randomised controlled trials. In each of these trials healthcare professionals received formal training in smoking cessation, and their performance was compared with that of a control group. MAIN MEASURES--Point prevalence rates of abstinence from smoking at six or 12 months in patients who were smokers at baseline. Rates of performance of tasks of smoking cessation by healthcare professionals, including offering counselling, setting dates to stop smoking, giving follow up appointments, distributing self help materials, and recommending nicotine gum. METHODS--Trials were identified by multiple methods. Data were abstracted according to predetermined criteria by two observers. When possible, meta-analysis was performed using a fixed effects model and the results were subjected to sensitivity analysis. RESULTS--Healthcare professionals who had received training were significantly more likely to perform tasks of smoking cessation than untrained controls. There was a modest increase in the odds of stopping smoking for smokers attending health professionals who had received training compared with patients attending control practitioners (odds ratio 1.35 (95% confidence interval 1.09 to 1.68)). This result was not robust to sensitivity analysis. The effects of training were increased if prompts and reminders were used. There was no definite benefit found for more intensive forms of counselling compared with minimal contact strategies. CONCLUSIONS--Training health professionals to provide smoking cessation interventions had a measurable impact on professional performance. A modest, but non-robust, effect on patient outcome was also found, suggesting that training alone is unlikely to be an effective strategy for improving quality of care, unless organisational and other factors are also considered. 相似文献
43.
The therapeutic response and toxic effects of chemotherapy using several doses of doxorubicin in conventional solution form or bound to an ion-exchange resin were compared in a rat tumor model, to assess the relationship of drug dose to therapeutic efficacy and associated toxicity. Single bolus injections of 3.0, 4.5, 6.0, 7.5 and 9.0 mg/kg were administered via the abdominal aorta to rats bearing hindlimb tumors. Tumor size was measured serially and the growth rates of treated groups were compared with a control growth curve. In addition, the effect of empty microspheres on tumor growth rate was assessed. The levels of circulating white blood cells were measured and compared to control levels to provide an indication of the severity of bone marrow toxicity experienced by each form of treatment. Finally, any difference in the distribution of doxorubicin to tumor, hindlimb and cardiac tissue following administration of doxorubicin as free drug or on microspheres was ascertained. Empty ion-exchange resin exerted a small although significant detrimental effect on tumor growth which may be explained by the embolization of microspheres in the precapillary blood vessels of the tumor resulting in a transient delay in tumor growth rate. The lowest dose of doxorubicin produced a significantly better therapeutic response when administered in the free drug form, but higher doses elicited an equivalent delay in tumor growth for both drug microsphere and free drug groups in a dose-dependent manner, with the maximum anti-tumor response occurring at the highest dose. Treatment with free doxorubicin at high doses resulted in significant reductions of circulating white blood cells suggesting the occurrence of bone marrow toxicity.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
44.
Effects of di-(2-ethylhexyl) phthalate and five of its metabolites on rat testis in vivo and in in vitro 总被引:2,自引:0,他引:2
In an attempt to establish which compound or compounds are responsible for the testicular damage observed after administration of di-(2-ethylhexyl) phthalate (DEHP) in rats, the effects of the parent compound and five of its major metabolites (mono-(2-ethylhexyl) phthalate (MEHP), 2-ethylhexanol (2-EH), mono-(5-carboxy-2-ethylpentyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate and mono-(2-ethyl-5-hydroxyhexyl) phthalate) were investigated in vivo and in vitro. The concentrations of MEHP and the three MEHP-derived metabolites in plasma were determined after single and multiple oral doses of DEHP. The plasma concentrations and areas under the plasma concentration-time curves (AUC's) of each of the MEHP-derived metabolites were considerably lower than those of MEHP both after single and after repeated administration of 2.7 mmol of DEHP/kg body weight. The mean elimination half-life of MEHP was significantly shorter in animals given repetitive doses than in those given a single dose, but there was no statistically significant difference between the mean AUC values. No testicular damage was observed in young rats given oral doses of 2.7 mmol of DEHP or 2-EH/kg body weight daily for five days. In animals which received corresponding doses of MEHP the number of degenerated spermatocytes and spermatids was increased, whereas no such effects were found in animals given the MEHP-derived metabolites. MEHP was also the only compound that enhanced germ cell detachment from mixed primary cultures of Sertoli and germ cells. 相似文献
45.
Pigmentary type of orthochromatic leukodystrophy (OLD): a new case with ultrastructural and biochemical study 总被引:2,自引:0,他引:2
F Gray A Destee J M Bourre R Gherardi I Krivosic P Warot J Poirier 《Journal of neuropathology and experimental neurology》1987,46(5):585-596
A 34-year-old woman with no family history of orthochromatic leukodystrophy (OLD) developed progressive intellectual deterioration, a frontal syndrome and spastic tetraparesis. She died four years after the onset of the clinical illness. Neuropathological studies included light and electron microscopy of cerebral and nerve biopsies, and a complete postmortem examination. Light microscopy demonstrated OLD with pigmented macrophages and glial cells. Electron microscopy showed electron-dense, membrane-bound intracytoplasmic lamellar inclusions with curved or straight parallel arrangement, or fingerprint pattern, in white matter macrophages, astrocytes and oligodendrocytes. Cortical cells contained lipofuscin which was normal in type and amount. This suggests that the material in white matter glial cells and macrophages is ceroid pigment, however, the distribution is not that seen in ceroid-lipofuscinosis. Similar inclusions have been found in oligodendrocytes in other forms of OLD. Biochemical study did not show evidence of demyelination. Galactolipids were normal. Polyunsaturated fatty acids were decreased. The most striking feature was an increase in plasmalogens. 相似文献
46.
47.
The authors describe the management by percutaneous drainage of a rare solitary tuberculous liver abscess in a 37-year-old woman. Open surgical drainage of such abscesses can be avoided using percutaneous drainage combined with transcatheter infusions of antituberculous agents. For the safe and successful use of this method three criteria must be met: the abscess should be unilocular, there must be a safe access route and a previously sterile compartment must not be contaminated. In addition a small (22 or 23 gauge) needle should be used for the initial puncture. 相似文献
48.
Zvi Bar-Shavit Ronald L. Horst Jean C. Chappel F. Patrick Ross Richard W. Gray Steven L. Teitelbaum M.D. 《Calcified tissue international》1986,39(5):328-333
Summary 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) is a potent inducer of monocytic differentiation of the human promyelocytic leukemia cell line, HL-60. We have noted that
25-hydroxyvitamin D3 (25(OH)D3) in high doses is also capable of promoting monocytic differentiation of this cell line. To test the possibility that the
latter activity is due to conversion of 25OHD3 to 1,25(OH)2D3 by HL-60, we exposed HL-60 cells to 25OHD3 and analyzed the products by HPLC and radioreceptor assay. When chromatographed in the traditional solvent system (isopropanol-hexane),
a new peak appears which migrates with authentic 1,25(OH)2D3. However, in a solvent system containing dichloromethane, 90% of the peak migrates with another metabolite, 19-Nor-10-Keto-25OHD3 (19-Nor-25OHD3). Production of this metabolite is enhanced by living cells and is synthesized by both virgin HL-60 and those which have
undergone differentiation. We next determined if authentic 19-Nor-25OHD3 also promotes differentiation of this cell. As assessed by appearance of the monocyte-specific surface antigen (63D3) and
macrophage-specific esterase activity, we find that this metabolite does, in fact, induce monocytic differentiation of HL-60
with a potency of approximately 1/200 that of 1,25(OH)2D3 and similar to that of 25OHD3. In agreement with the effect upon cell maturation, 19-Nor-25OHD3 displaces3H-1,25(OH)2D3 from its HL-60 receptor with an efficiency comparable to 25OHD3. Hence, HL-60 cells convert 25OHD3 to 19-Nor-25OHD3, and 19-Nor-25OHD3 induces monocytic differentiation of HL-60 with comparable efficiency to its precursor, 25OHD3. 相似文献
49.
A case of intracerebral malignant B cell lymphoma associated with encephalitis typical of Human Immunodeficiency Virus (HIV)
infection is described in a 4 year old child, with post-transfusion Acquired Immune Deficiency Syndrome (AIDS) and severe
pre-existing cystic encephalomalacia. This report further documents B cell lymphoma as the commonest cause of an intracerebral
mass, and an important cause of death in paediatric AIDS. That more than one pathological process may be responsible for neurological
symptoms in paediatric AIDS is also emphasised. 相似文献
50.