全文获取类型
收费全文 | 337932篇 |
免费 | 8463篇 |
国内免费 | 466篇 |
专业分类
耳鼻咽喉 | 3500篇 |
儿科学 | 11888篇 |
妇产科学 | 7571篇 |
基础医学 | 38947篇 |
口腔科学 | 6163篇 |
临床医学 | 23135篇 |
内科学 | 68195篇 |
皮肤病学 | 6085篇 |
神经病学 | 29697篇 |
特种医学 | 12608篇 |
外国民族医学 | 31篇 |
外科学 | 49515篇 |
综合类 | 3125篇 |
一般理论 | 39篇 |
预防医学 | 34693篇 |
眼科学 | 6094篇 |
药学 | 21116篇 |
中国医学 | 1151篇 |
肿瘤学 | 23308篇 |
出版年
2023年 | 907篇 |
2022年 | 1520篇 |
2021年 | 3651篇 |
2020年 | 1921篇 |
2019年 | 3613篇 |
2018年 | 26346篇 |
2017年 | 20000篇 |
2016年 | 22207篇 |
2015年 | 4324篇 |
2014年 | 5286篇 |
2013年 | 7384篇 |
2012年 | 16768篇 |
2011年 | 30809篇 |
2010年 | 24096篇 |
2009年 | 16136篇 |
2008年 | 27463篇 |
2007年 | 30029篇 |
2006年 | 9153篇 |
2005年 | 10771篇 |
2004年 | 11391篇 |
2003年 | 11760篇 |
2002年 | 9621篇 |
2001年 | 5522篇 |
2000年 | 5819篇 |
1999年 | 4689篇 |
1998年 | 1448篇 |
1997年 | 1086篇 |
1996年 | 926篇 |
1995年 | 819篇 |
1994年 | 701篇 |
1992年 | 2281篇 |
1991年 | 2229篇 |
1990年 | 2126篇 |
1989年 | 1840篇 |
1988年 | 1657篇 |
1987年 | 1614篇 |
1986年 | 1485篇 |
1985年 | 1435篇 |
1984年 | 1058篇 |
1983年 | 908篇 |
1979年 | 1008篇 |
1978年 | 679篇 |
1975年 | 682篇 |
1974年 | 903篇 |
1973年 | 860篇 |
1972年 | 744篇 |
1971年 | 699篇 |
1970年 | 766篇 |
1969年 | 728篇 |
1968年 | 688篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
G López Casasnovas 《Gaceta sanitaria / S.E.S.P.A.S》1989,3(15):573-580
The following pages try to offer some ways of arguing against pesimism in our health administration culture. In fact, the review of a wide range of feasible reforms of our health system undertaken in this paper gives some clues for a better implementation of the a priori advantages of public health systems. These advantages are not achieved today because of some dysfunctionalities of daily management. To rationalize resources distribution, to evaluate the results, to eliminate unnecessary administrative control, to coordinate responsibility and budgeting centers, to introduce free choice as a response to public demand, and to simulate marketing by private production of public services are elements suggested in this paper to improve public health services management. 相似文献
52.
53.
54.
M Gómez-Silva L Garza-Oca?as N Waksman V Rivas A Pi?eyro-López 《Toxicology in vitro》2005,19(1):47-53
T-514 (Peroxisomicine A(1)) from Karwinskia humboldtiana is a dimeric hydroxyanthracenone with a highly selective cytotoxic effect on tumor cells. We evaluated the metabolism of this compound in two in vitro systems (liver microsomes and hepatocytes) and assessed the cytotoxicity of its metabolites on normal and tumor cells. Microsomes (12.5, 125 and 250 microg of protein/ml) and hepatocytes (1 x 10(6) cells/ml) were incubated with the toxin (25 microM) for 0.5, 1, 3, 6, 9, 12 and 24 h and the samples were examined using chromatographic analysis and UV spectra. Two metabolites (M1 and M2) were detected in the rat microsomes and one (M1) in the monkey microsomes. The retention times and UV spectra of the peaks were very similar to those of the toxin T-514. M1 was isolated and identified as a mixture of two isomers. The cytotoxicity of the metabolites was evaluated in Chang liver and Hep G2 cells but they did not show the selective cytotoxic effect on tumor cells seen in the original compound. 相似文献
55.
56.
H Danielson A Kokkola T Kiviluoto J Sirén J Louhimo E Kivilaakso P Puolakkainen 《Scandinavian journal of surgery》2007,96(1):35-40
BACKGROUND: Clinical benefit from extended lymphadenectomy for gastric cancer remains controversial as a considerable variation exists between results of different studies. METHODS: 562 patients were treated at HUCH between 1987-2003, whereof 223 underwent gastrectomy with curative intent. Of these, 114 patients underwent subtotal/total gastrectomy with D1 (standard) lymphadenectomy and 109 patients had D2-3 (extended) lymph node dissection. The clinical outcome of these patients was analysed retrospectively. RESULTS: The incidence of surgical complications was 33.0% in D2-3 and 16.8% in D1 lymphadenectomy groups (p = 0.008). Abscess was the most common complication (11.0%) among D2-3 operated patients and haemorrhage (4.4%) in D1 group. Hospital mortality was 3.7% in D2-3 and 1.8% in D1 group (p = 0.438). The only statistically significant factor influencing the rate of complications was D2-3 lymphadenectomy (OR 2.620, 95% C.I. 1.375 to 4.991). D2-3 was associated with a longer postoperative hospital stay and operation time, greater blood loss and increased need for blood transfusions compared to D1. The 5-year survival was not statistically different between lymphadenectomy groups. CONCLUSION: It is justified to perform a D2-3 gastrectomy in Europe with a acceptable postoperative mortality but with a significant morbidity. Further studies are needed to assess the value of extended lymphadenectomy in gastric cancer. 相似文献
57.
Background
Health service policy in the United Kingdom emphasises the importance of self-care by patients with chronic conditions. Written information for patients about their condition is seen as an important aid to help patients look after themselves. From a discourse analysis perspective written texts such as patient information leaflets do not simply describe the reality of a medical condition and its management but by drawing on some sorts of knowledge and evidence rather than others help construct the reality of that condition. This study explored patient information leaflets on osteoarthritis (OA) to see how OA was constructed and to consider the implications for self-care. 相似文献58.
Javier Garzón Almudena López-Fando Pilar Sánchez-Blázquez 《Neuropsychopharmacology》2003,28(11):1983-1990
Members of the R7 subfamily of regulators of G-protein signaling (RGS) proteins (RGS6, RGS7, RGS9-2, and RGS11) are found in the mouse CNS. The expression of these proteins was effectively reduced in different neural structures by blocking their mRNA with antisense oligodeoxynucleotides (ODNs). This was achieved without noticeable changes in the binding characteristics of labeled beta-endorphin to opioid receptors. Knockdown of R7 proteins enhanced the potency of antinociception promoted by morphine and [D-Ala(2), N-MePhe(4), Gly-ol(5)]-enkephalin (DAMGO)-both agonists at mu-opioid receptors. The duration of morphine analgesia was greatly increased in RGS9-2 and in RGS11 knockdown mice. The impairment of R7 proteins brought about different changes in the analgesic activity of selective delta agonists. Knockdown of RGS11 reduced [D-Ala(2)]deltorphin II analgesic effects. Those of RGS6 and RGS9-2 proteins caused [D-Ala(2)]deltorphin II to produce a smoothened time-course curve-the peak effect blunted and analgesia extended during the declining phase. RGS9-2 impairment also promoted a similar pattern of change for [D-Pen(2,5)]-enkephalin (DPDPE). RGS7-deficient mice showed an increased response to both [D-Ala(2)]deltorphin II and DPDPE analgesic effects. A single intracerebroventricular (i.c.v.) ED(80) analgesic dose of morphine gave rise to acute tolerance in control mice, but did not promote tolerance in RGS6, RGS7, RGS9-2, or RGS11 knockdown animals. Thus, R7 proteins play a critical role in agonist tachyphylaxis and acute tolerance at mu-opioid receptors, and show differences in their modulation of delta-opioid receptors. 相似文献
59.
M D Blanco M V Bernardo R L Sastre R Olmo E Mu?iz J M Teijón 《European journal of pharmaceutics and biopharmaceutics》2003,55(2):229-236
Poly(epsilon-caprolactone) microspheres containing bupivacaine were prepared by the spray-drying process. The average size of drug loaded microspheres was less than 3 microm in diameter, and the percentage of entrapment efficiency was 91 +/- 3%. In vitro drug release kinetic in phosphate buffer at 37 degrees C showed a hyperbolic profile, with a burst-effect during the first hour. Subcutaneous injection of bupivacaine-loaded microspheres in the back of rats caused an increase in drug concentration in plasma. Maximum bupivacaine concentration in plasma was 237 +/- 58 ng/ml at 105 h, and drug was detected in plasma for 16 days. The half-life time of the drug was increased by more than 125 times with regard to that of the drug administered in a solution by intraperitoneal injection. After 30 days of injection, a mass formed by microspheres surrounded by a thin fibrous capsule was observed. Small blood vessels and multinucleate foreign body giant cells with macrophagic function around microspheres were detected. After 60 days of injection a subcutaneous mass was also observed, which was formed of more degraded dispersed microspheres in conjunctive tissue, which had a normal structure. Thus, bupivacaine-loaded poly(epsilon-caprolactone) microspheres could be considered as a device to be used in the treatment of severe pain that is not responsive to opioids for example in cancer-related syndromes or in intractable herpetic neuralgia. 相似文献
60.
Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis
Barbara Bordini Susanna Stea Manuela De Clerico Sergio Strazzari Antonio Sasdelli Aldo Toni 《BMC musculoskeletal disorders》2007,8(1):69