全文获取类型
收费全文 | 325922篇 |
免费 | 15920篇 |
国内免费 | 783篇 |
专业分类
耳鼻咽喉 | 4277篇 |
儿科学 | 9842篇 |
妇产科学 | 7239篇 |
基础医学 | 45944篇 |
口腔科学 | 12416篇 |
临床医学 | 21561篇 |
内科学 | 71610篇 |
皮肤病学 | 8523篇 |
神经病学 | 26835篇 |
特种医学 | 9323篇 |
外国民族医学 | 29篇 |
外科学 | 38945篇 |
综合类 | 2135篇 |
现状与发展 | 1篇 |
一般理论 | 89篇 |
预防医学 | 36564篇 |
眼科学 | 7375篇 |
药学 | 22700篇 |
中国医学 | 1313篇 |
肿瘤学 | 15904篇 |
出版年
2023年 | 1639篇 |
2022年 | 2564篇 |
2021年 | 5983篇 |
2020年 | 3779篇 |
2019年 | 6154篇 |
2018年 | 9363篇 |
2017年 | 6434篇 |
2016年 | 6268篇 |
2015年 | 7092篇 |
2014年 | 8991篇 |
2013年 | 12240篇 |
2012年 | 19908篇 |
2011年 | 20817篇 |
2010年 | 10523篇 |
2009年 | 8753篇 |
2008年 | 16631篇 |
2007年 | 17866篇 |
2006年 | 16753篇 |
2005年 | 16800篇 |
2004年 | 15767篇 |
2003年 | 14527篇 |
2002年 | 12371篇 |
2001年 | 9690篇 |
2000年 | 10165篇 |
1999年 | 8293篇 |
1998年 | 2270篇 |
1997年 | 1752篇 |
1996年 | 1746篇 |
1995年 | 1501篇 |
1994年 | 1416篇 |
1992年 | 4838篇 |
1991年 | 4493篇 |
1990年 | 4280篇 |
1989年 | 3964篇 |
1988年 | 3687篇 |
1987年 | 3440篇 |
1986年 | 3348篇 |
1985年 | 3167篇 |
1984年 | 2300篇 |
1983年 | 1912篇 |
1979年 | 2131篇 |
1978年 | 1423篇 |
1975年 | 1417篇 |
1974年 | 1666篇 |
1973年 | 1713篇 |
1972年 | 1559篇 |
1971年 | 1487篇 |
1970年 | 1466篇 |
1969年 | 1539篇 |
1968年 | 1554篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
C de Costa 《The Medical journal of Australia》1986,144(13):721-722
72.
73.
P.C.G. Simons A.A. Nawijn C.M.A. Bruijninckx B. Knippenberg E.H. de Vries H. van Overhagen 《European journal of vascular and endovascular surgery》2006,32(6):627-633
OBJECTIVE: To determine the safety and the long-term results of primary stent placement for localized distal aortic occlusive disease. DESIGN: Retrospective observational study. PATIENTS AND METHODS: From July 1998 to July 2005 17 patients (14 female and 3 men, mean age 57 years (39-80)) were treated for intermittent claudication. Five of these patients underwent additional endovascular treatment of focal iliac lesions. RESULTS: Technical success defined as residual stenosis of less than 50% or a trans-stenotic systolic pressure gradient <10% was achieved in 14 of 17 (82%) patients. Major complications included dissection at the puncture site in one patient and thrombosis of additional iliac stents in another patient. Both of these complications were successfully treated. During a mean follow-up of 27 months (range 1-86), four patients had recurrence of symptoms due to in-stent restenoses (n=2), femoral (n=1) or iliac occlusion (n=1), respectively. By Kaplan-Meier analysis, primary aortic hemodynamic patency was 83% at 3 years. Secondary aortic hemodynamic patency was 100%. The primary clinical patency was 68% at 3 years. CONCLUSION: Primary stent placement for distal aortic stenoses is an alternative to surgical treatment because of its high patency and relatively low complication rates. 相似文献
74.
The study of the cognitive abilities of hearing-impaired children is important for both practical (e.g. to determine appropriate teaching strategies) and theoretical reasons (e.g. to examine the role of language in thought processes). The aim of this paper is to examine the cognitive function of hearing-impaired children from a review of the literature. If most studies show that deaf children are similar to normal children in virtually all aspects of cognitive function, many studies also emphasize pronounced differences in their academic achievement. Besides the degree of hearing loss and the age at onset of deafness, environmental factors (such as parental support and educational methods) seem to play an important role in the cognitive development and academic success of these children. This underlines the importance of the measures adopted for the deaf children as they may have a positive or negative impact on their development. 相似文献
75.
Pilar Nicolás 《Hereditary cancer in clinical practice》2007,5(3):144-152
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing. 相似文献
76.
Cyclodextrin formulation of dorzolamide and its distribution in the eye after topical administration. 总被引:2,自引:0,他引:2
Hakon H Sigurdsson Einar Stefánsson Elínborg Gudmundsdóttir Thór Eysteinsson Margrét Thorsteinsdóttir Thorsteinn Loftsson 《Journal of controlled release》2005,102(1):255-262
Due to limited aqueous solubility of dorzolamide at physiologic pH, the pH of Trusopt eye drops (cont. 2% dorzolamide) has to be kept at about 5.65, and to increase the topical bioavailability of the drug from Trusopt the contact time of the drug with the eye surface is increased by increasing the viscosity of the eye drops to 100 cps. This low pH and high viscosity can lead to local irritation. In this study, dorzolamide hydrochloride was formulated as 2% and 4% low viscosity solutions (viscosity 3 to 5 cps) containing randomly methylated beta-cyclodextrin at pH 7.45. These formulations were evaluated in rabbits. The animals were sacrificed at various time points after topical administration of the drug and the dorzolamide concentration determined in the different parts of the eye. Trusopt was used as a reference standard. The topical availability of dorzolamide from the cyclodextrin-containing eye drops appeared to be comparable to that from Trusopt and the drug reached retina and optic nerve to give measurable concentrations for at least 8 h after administration of the eye drops. 相似文献
77.
G Pelletier A M de Passillé M Bernier-Cardou J Morisset 《The Journal of nutrition》1987,117(10):1759-1766
In the first experiment, 52 sows, each having raised one litter, were randomly assigned to the five following groups: control (nongravid) for pregnancy (CP), 110 d pregnancy (P110), control (nongravid) for lactation (CL), 4-wk lactation with 8 (L8) and with 12 (L12) piglets. In a second experiment, 36 sows, each having raised three litters, were randomly assigned to the following groups: control group (nongravid) fed a low-energy-density, 1% tallow diet (CLED) and two lactating groups, one fed the low-energy-density diet (LLED) and one fed a high-energy-density, 10% tallow diet (LHED). At slaughter, the stomach, small and large intestine and cecum were excised, emptied and freed from fat. Lengths and pre- and post-defatting weights were measured. Portions of tissues were homogenized and analyzed for protein, pepsin, maltase, RNA and DNA. Pregnancy had no effect on the weights of the different components of the gastrointestinal tract. Liver and small intestine weights were larger in lactating sows than in the CL group. Sows nursing 12 piglets had heavier livers than those nursing 8. The fundic mucosa of the latter had higher total pepsin activity and total protein and RNA contents than that of L12 sows. LHED sows had heavier small intestine and lower total pepsin content of the fundic mucosa than LLED sows. 相似文献
78.
79.
P M A van Haaren H P Kok C A T van den Berg P J Zum V?rde Sive V?rding S Oldenborg L J A Stalpers M S Schilthuis A A C de Leeuw J Crezee 《International journal of hyperthermia》2007,23(3):303-314
PURPOSE: The aim of this study was to verify hyperthermia treatment planning calculations by means of measurements performed during hyperthermia treatments. The calculated specific absorption rate (SAR(calc)) was compared with clinically measured SAR values, during 11 treatments in seven cervical carcinoma patients. METHODS: Hyperthermia treatments were performed using the 70 MHz AMC-4 waveguide system. Temperatures were measured using multisensor thermocouple probes. One invasive thermometry catheter in the cervical tumour and two non-invasive catheters in the vagina were used. For optimal tissue contact and fixation of the catheters, a gynaecological tampon was inserted, moisturized with distilled water (4 treatments), or saline (6 treatments) for better thermal contact. During one treatment no tampon was used. At the start of treatment the temperature rise (DeltaT(meas)) after a short power pulse was measured, which is proportional to SAR(meas). The SAR(calc) along the catheter tracks was extracted from the calculated SAR distribution and compared with the DeltaT(meas)-profiles. RESULTS: The correlation between DeltaT(meas) and SAR(calc) was on average R = 0.56 +/- 0.28, but appeared highly dependent on the wetness of the tampon (preferably with saline) and the tissue contact of the catheters. Correlations were strong (R approximately 0.85-0.93) when thermal contact was good, but much weaker (R approximately 0.14-0.48) for cases with poor thermal contact. CONCLUSION: Good correlations between measurements and calculations were found when tissue contact of the catheters was good. The main difficulties for accurate verification were of clinical nature, arising from improper use of the gynaecological tampon. Poor thermal contact between thermocouples and tissue caused measurement artefacts that were difficult to correlate with calculations. 相似文献
80.
E García-Gómez S Vaca A Pérez-Méndez J Ibarra-Caballero V Pérez-Márquez V R Tenorio E Negrete-Abascal 《Avian pathology》2005,34(5):426-429
Gallibacterium anatis (previously named Pasteurella haemolytica-like) is considered a normal inhabitant of genital and upper respiratory tracts of healthy chickens, but it is also associated with different pathological conditions. Secreted metalloproteases from field and reference G. anatis cultures were obtained by methanol precipitation and were characterized. Proteins of molecular mass higher than 100 kDa showing proteolytic activity were observed in 10% polyacrylamide gels copolymerized with 1% bovine casein. They were active at alkaline pH, and inhibited by ethylenediamine tetraacetic acid. Their activity was stable at 50 degrees C, but partially inhibited at 60 degrees C, and totally inhibited at higher temperatures. Secreted proteins were able to degrade chicken IgG after 24 h of incubation, and cross-reacted with a polyclonal antibody against purified protease from Actinobacillus pleuropneumoniae. Secreted metalloproteases could play a role in infections caused by G. anatis. 相似文献