全文获取类型
收费全文 | 28779篇 |
免费 | 2216篇 |
国内免费 | 128篇 |
专业分类
耳鼻咽喉 | 423篇 |
儿科学 | 929篇 |
妇产科学 | 552篇 |
基础医学 | 3416篇 |
口腔科学 | 801篇 |
临床医学 | 2212篇 |
内科学 | 6404篇 |
皮肤病学 | 897篇 |
神经病学 | 1655篇 |
特种医学 | 1003篇 |
外国民族医学 | 10篇 |
外科学 | 4669篇 |
综合类 | 511篇 |
一般理论 | 10篇 |
预防医学 | 2055篇 |
眼科学 | 774篇 |
药学 | 2566篇 |
1篇 | |
中国医学 | 257篇 |
肿瘤学 | 1978篇 |
出版年
2023年 | 275篇 |
2022年 | 859篇 |
2021年 | 1261篇 |
2020年 | 785篇 |
2019年 | 1189篇 |
2018年 | 1424篇 |
2017年 | 939篇 |
2016年 | 1078篇 |
2015年 | 1006篇 |
2014年 | 1353篇 |
2013年 | 1757篇 |
2012年 | 2247篇 |
2011年 | 2335篇 |
2010年 | 1503篇 |
2009年 | 1208篇 |
2008年 | 1520篇 |
2007年 | 1505篇 |
2006年 | 1389篇 |
2005年 | 1199篇 |
2004年 | 1055篇 |
2003年 | 775篇 |
2002年 | 739篇 |
2001年 | 489篇 |
2000年 | 488篇 |
1999年 | 388篇 |
1998年 | 163篇 |
1997年 | 114篇 |
1996年 | 110篇 |
1995年 | 86篇 |
1994年 | 87篇 |
1993年 | 84篇 |
1992年 | 104篇 |
1991年 | 122篇 |
1990年 | 104篇 |
1989年 | 105篇 |
1988年 | 77篇 |
1987年 | 86篇 |
1986年 | 62篇 |
1985年 | 71篇 |
1984年 | 121篇 |
1983年 | 90篇 |
1982年 | 64篇 |
1981年 | 55篇 |
1980年 | 68篇 |
1979年 | 85篇 |
1978年 | 69篇 |
1977年 | 54篇 |
1976年 | 45篇 |
1975年 | 64篇 |
1974年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
F Reichenberger R Voswinckel B Enke M Rutsch E El Fechtali T Schmehl H Olschewski R Schermuly N Weissmann H A Ghofrani F Grimminger E Mayer W Seeger 《The European respiratory journal》2007,30(5):922-927
For chronic thromboembolic pulmonary hypertension not amenable to pulmonary endarterectomy, effective medical therapy is desired. In an open-label uncontrolled clinical trial, 104 patients (mean +/- sem age 62 +/- 11 yrs) with inoperable chronic thromboembolic pulmonary hypertension were treated with 50 mg sildenafil t.i.d. At baseline, patients had severe pulmonary hypertension (pulmonary vascular resistance 863 +/- 38 dyn.s.cm(-5)) and a 6-min walking distance of 310 +/- 11 m. Eight patients were in World Health Organization functional class II, 76 in class III and 20 in class IV. After 3 months' treatment, there was significant haemodynamic improvement, with reduction of pulmonary vascular resistance to 759 +/- 62 dyn.s.cm(-5). The 6-min walking distance increased significantly to 361 +/- 15 m after 3 months' treatment, and to 366 +/- 18 m after 12 months' treatment. A subset of 67 patients received a single dose of 50 mg sildenafil during initial right heart catheterisation. The acute haemodynamic effect of this was not predictive of long-term outcome. In this large series of patients with inoperable chronic thromboembolic pulmonary hypertension, open-label treatment with sildenafil led to significant long-term functional improvement. The acute effect of sildenafil may not predict the long-term outcome of therapy. 相似文献
12.
Initially, there is a high incidence of CNS-depressant side-effects when the aromatase inhibitor, aminoglutethimide, is used in the treatment of patients with advanced breast cancer. Tolerance to these effects develops with continued dosing. This study examines the development of tolerance to various indices of CNS depression with the drug in mice. Single doses of aminoglutethimide induced a dose-dependent depression of spontaneous locomotor activity, rotarod performance, righting reflex and body temperature and a dose-related antileptazol activity. On repeated dosing with the drug, tolerance to these various activities occurred. The tolerance was found to be dose-dependent in the rotarod and righting reflex tests and time-dependent in the locomotor and body temperature tests. Although the results do not allow a determination of whether this clearly demonstrated phenomenon in the mouse is primarily functional or dispositional, the slow onset (14 days) for complete tolerance may be indicative of a functional mechanism. 相似文献
13.
14.
G Ahmad 《Journal of toxicology. Clinical toxicology》1987,25(4):341-346
Emergency Room patients at Riverside General Hospital who are found by the attending physician to have depressed sensorium and altered personality are routinely subjected to urine tests for various drugs of abuse including phencyclidine (PCP). The findings of the laboratory analysis of these patients are presented in this paper. The toxicology laboratory of this hospital performs screening procedures for various drugs on urine specimens by thin layer chromatography. Drugs detected are confirmed by gas chromatography and a homogeneous enzyme immunoassay technique. In 1981, 1.6% of the urine specimens of patients in the above-mentioned category were found to be positive for PCP. This percentage increased sharply during 1982 (5.8%) and 1983 (5.6%). During 1984 and 1985 the percentage dropped to 4.2% and 4.6%. It is implied from data that the abuse of this drug in this area has leveled off. The data also indicated that PCP is predominantly used by young adults with ages ranging from 21 to 30 years. The abuse of this drug in people over 40 years of age is comparatively very small. Among users of this drug, 67.5% are men and 32.5% are women. Out of 68 women found to be abusing PCP, 5 delivered their babies in this hospital. PCP was detected in the urine specimens of each of these babies. Four out of the five infants showed withdrawal symptoms such as extreme irritability, jitteriness, hyperactivity with high pitched cries and a poor ability to take food. 相似文献
15.
Dr. med. Dipl.-Soz. T. Krones E. Schlüter S. El Ansari T. Wissner R. Zoll G. Richter 《Gyn?kologische Endokrinologie》2004,2(4):245-250
Preimplantation genetic diagnosis (PGD) has been vigorously debated in Germany ever since the Bundesärztekammer (BÄK) published a draft of guidelines for PGD in March 2000. Many stakeholders such as churches, medical societies, and diverse associations have participated in the discussion. However, little is known about the attitudes of experts, directly affected patient groups, and the public in Germany. In several studies that are part of the German research program on ethical implications of the Human Genome Project, representative surveys were undertaken to assess the attitudes of the general population (n=1017), five relevant expert groups (n=879), and couples at high risk for genetic disorders(n=324) towards PGD and prenatal diagnosis (PD). All groups favor legislation for PGD. Differences exist in regard to the extent of their approval. For 17% of the high-risk couples with a persisting desire for a child, PGD performed in a neighboring country is the most probable reproductive option. These results should be carefully considered in the ongoing legislation process on human reproduction in our country. 相似文献
16.
D Loutradis K Stefanidis P Drakakis K Kallianidis A El Sheikh S Milingos K Siskos S Michalas 《Gynecological endocrinology》2003,17(2):101-106
The purpose of this study was to investigate the ovarian response and the receptivity of the endometrium in women pre-treated with micronized progesterone. Eighty-two normogonodotropic women undergoing in vitro fertilization were studied. Thirty received micronized progesterone 1500 mg/day from day 21 of the cycle for a minimum of 2 weeks, and 52 did not receive micronized progesterone (control group). A gonadotropin releasing hormone agonist (GnRH-a) was administered to all the patients in the follicular phase (flare-up). Twenty-five cycles were cancelled for fertilization failure due to male factor, 12 (40%) in the progesterone group and 13 (25%) in the control group (p = 0.271). There was no difference in the number of oocytes retrieved (7.3 +/- 5 vs. 8.2 +/- 4), fertilization rate (50.8% vs. 65%), clinical pregnancy rate (16.6% vs. 25%) or implantation rate (8% vs. 14%). In the progesterone group cases without fertilization, we performed two biopsies to evaluate the receptivity of the endometrium. Pinopode expression was noted 7 days after oocyte retrieval. It seems that the administration of micronized progesterone in the previous cycle does not affect the ovarian response to the combination of follicular phase GnRH-a and gonadotropins, nor the receptivity of the endometrium. 相似文献
17.
Sir, I read with great interest the letter by Higgins and co-workers[1]. 相似文献
18.
19.
J. M. Porcher C. Lafuma R. El Nabout M. P. Jacob P. Sébastien P. A. Borm S. Honnons G. Auburtin 《International archives of occupational and environmental health》1993,65(Z1):S209-S213
This research is designed to evaluate a number of biological markers to estimate harmful exposure on coal miners from different mining regions in France and to relate the outcome to differences in prevalence of coal worker pneumoconiosis (CWP) between these regions. Eight epidemiological groups of active and ex-miners (smokers and non-smokers) have been selected in the French collieries (North, Lorraine and Provence) according to their occupational and pneumoconiotic status. The following biomarkers have been evaluated: cellularity of sputum, elementary analysis of particles in TEM/EDAX, plasma neutral metalloendo peptidase elastase type (NMEP), leucocyte elastase (HLE), fibronectin (FN) and elastin peptides. Pulmonary alveolitis, expressed by sputum cellularity, is different between active workers groups but not related to the general background of pneumoconiosis prevalence in the French collieries. In the plasma parameters, fibronectin, HLE and NMEP significantly increased in all groups of coal mine workers as compared to the control group, except for fibronectin parameter in Lorraine collierie. The degree of increase of these parameters allow us to discriminate the different groups and suggest that plasma FN, HLE and NMEP may be considered as biological markers of chronic inhalation of coal mine dust particles. The decrease of elastin peptides level in the Lorraine group alone suggests a specific alteration of elastin metabolism. These parameters were not related to the development of pneumoconiosis and its degree of severity. 相似文献
20.