全文获取类型
收费全文 | 2066篇 |
免费 | 105篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 70篇 |
妇产科学 | 31篇 |
基础医学 | 305篇 |
口腔科学 | 73篇 |
临床医学 | 158篇 |
内科学 | 542篇 |
皮肤病学 | 8篇 |
神经病学 | 172篇 |
特种医学 | 80篇 |
外科学 | 407篇 |
综合类 | 2篇 |
预防医学 | 98篇 |
眼科学 | 9篇 |
药学 | 89篇 |
肿瘤学 | 123篇 |
出版年
2023年 | 6篇 |
2022年 | 29篇 |
2021年 | 42篇 |
2020年 | 28篇 |
2019年 | 45篇 |
2018年 | 67篇 |
2017年 | 46篇 |
2016年 | 40篇 |
2015年 | 44篇 |
2014年 | 71篇 |
2013年 | 88篇 |
2012年 | 130篇 |
2011年 | 153篇 |
2010年 | 103篇 |
2009年 | 90篇 |
2008年 | 130篇 |
2007年 | 136篇 |
2006年 | 113篇 |
2005年 | 121篇 |
2004年 | 119篇 |
2003年 | 108篇 |
2002年 | 98篇 |
2001年 | 27篇 |
2000年 | 30篇 |
1999年 | 41篇 |
1998年 | 30篇 |
1997年 | 24篇 |
1996年 | 15篇 |
1995年 | 14篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 23篇 |
1991年 | 11篇 |
1990年 | 13篇 |
1989年 | 18篇 |
1988年 | 15篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 2篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1978年 | 2篇 |
1974年 | 2篇 |
1970年 | 3篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1965年 | 3篇 |
1904年 | 1篇 |
排序方式: 共有2173条查询结果,搜索用时 15 毫秒
1.
IgA antiendomysium antibodies in human umbilical cord sections as a screening test in relatives of patients with celiac disease 总被引:1,自引:0,他引:1
M. Bagnasco P. Montagna A. De Alessandri E. Castellano G. P. Pesce R. Gatti 《Allergy》1997,52(10):1017-1021
We performed the serum IgA antiendomysium antibody (EmA) assay by indirect immunofluorescence on human umbilical cord sections in 86 subjects with celiac disease, in 187 first-degree relatives of such patients, and in a control group of 68 unrelated subjects, to investigate the suitability of the method in the screening of populations at risk of gluten sensitivity. Conventional EmA assay using monkey esophagus sections was performed in parallel experiments. The results obtained showed a perfpect correlation between the two methods. All the celiac patients and none of the controls were positive for EmA. EmA positivity was also observed in 11 apparently healthy relatives: intestinal biopsy performed in five of them invariably showed villous atrophy and increase of mucosal lymphocytes. Taking into account the low cost of EmA assay on human umbilical cord, especially when compared to monkey esophagus sections, the method is probably suitable and effective in identifying latent, asymptomatic gluten sensitivity in at-risk populations. 相似文献
2.
Nicolas Feltgen Heiko Mueller Beat Ott Martin Frenz Jens Funk 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2003,241(2):94-100
PURPOSE:. To compare the efficacy of endoscopic erbium:YAG laser goniopuncture in glaucoma treatment to trabeculectomy, both methods as adjuncts to cataract surgery. METHODS:. Fifty-nine eyes of 59 glaucoma patients with coexistent cataract were treated by phacoemulsification and endoscopic Er:YAG goniopuncture in a combined fashion. The primary study endpoints were intraocular pressure (IOP), number of antiglaucomatous drugs, postoperative complications, hospitalisation time and visual acuity at 1 year after surgery. To date, 24 eyes have finished the 1-year follow-up. This prospective treatment arm was compared to a retrospective inclusion-matched control group treated by trabeculectomy and cataract surgery in a single procedure. RESULTS:. In the laser-treated group, the mean IOP dropped by 30% from 23.4+/-3.7 mmHg to 16.3+/-6 mmHg ( P<0.0001) after 12 months. Without reoperation, treatment was successful in 71% of these eyes. In the control group, the IOP decreased by 33.5% from 22.7+/-3.3 mmHg to 15.1+/-3.8 mmHg ( P<0.0001). The success rate without reoperation was 46%. The number of antiglaucomatous drugs needed decreased from 1.48+/-0.95 to 0.48+/-0.7 ( P<0.0001) in the laser-treated group and from 2.0+/-0.9 to 0.39+/-0.6 ( P<0.0001) in the control group. Postoperative complications were found more frequently in the control group ( P<0.0001). Hospitalisation was shorter in the laser group ( P<0.0001). Postoperative visual acuity was lower in the control group ( P=0.004). CONCLUSION:. Combined Er:YAG goniopuncture and cataract surgery lowers the IOP to an extent comparable to combined trabeculectomy and cataract surgery. Due to fewer postoperative complications, Er:YAG goniopuncture seems to be superior to standard fistulation surgery as the primary approach within the first year. 相似文献
3.
Hypoplasia of the Posterior Leaflet as a Rare Cause of Congenital Mitral Insufficiency 总被引:1,自引:0,他引:1
Afksendiyos Kalangos M.D. Ph.D. Ingrid Oberhansli M.D. Ary Baldovinos M.D. Maurice Beghetti M.D. Beat Friedli M.D. Bernard Faidutti M.D. 《Journal of cardiac surgery》1997,12(5):339-342
A bstract A rare case of congenital mitral insufficiency characterized by the hypoplasia of the posterior leaflet is reported. At operation, the mitral valve was successfully repaired by a ring annuloplasty, which created a satisfactory surface of coaptation between the anterior leaflet and the bulky posterior muscular structure. The presence of this posterior muscular structure represents a developmental arrest at the stage of conversion from muscular chordae and leaflets to thin connective structures. 相似文献
4.
In order to verify if H2O2 affects platelet function, platelet-rich plasma and human washed platelets were incubated with subthreshold concentrations (STC) of collagen or arachidonic acid or ADP and/or with 75-150 microM H2O2. While H2O2 alone did not affect platelet aggregation, it amplified platelet aggregation response in samples stimulated with STC of arachidonic acid and collagen but not in samples stimulated with STC of ADP. When platelets were preventively treated with aspirin, a cyclooxygenase inhibitor, the platelet activation by H2O2 was not observed. Thromboxane A2 (TxA2) was not produced by human washed platelets stimulated with STC of arachidonic acid, collagen or by H2O2 alone. On the contrary, when STC of agonists were tested on platelets supplemented with H2O2 an evident TxA2 production was seen. This effect was prevented by aspirin pretreatment or by the addition of catalase, an enzyme which destroys H2O2. This study suggests that H2O2 triggers the activation of platelets exposed to STC of collagen and arachidonic acid, via the cyclooxygenase pathway. 相似文献
5.
Beat M. Jucker Maria L. Barnard Robert G. Shulman 《Alcoholism, clinical and experimental research》1994,18(6):1377-1385
Weight gain efficiency differences previously reported between alcohol-fed rats and their controls were investigated. Additionally, the futile cycling of ethanol proposed to explain such differences was studied by NMR spectroscopy. Male Sprague-Dawley rats were fed a nutritionally adequate diet containing 36% of the calories as alcohol, and their paired controls were fed an isocaloric diet for 1 f weeks to establish conditions of chronic alcohol feeding. Normalized metabolic efficiencies varied significantly during the initial 2-week period (6.86 ± 0.51 vs. 2.83 ± 0.18 g/kcal × 10−2 ) for control and alcohol-fed groups, respectively, and to a lesser extent over the entire feeding period (6.41 ± 0.78 vs. 4.60 ± 0.27 g/kcal × 10−2 ) for control and alcohol-fed groups, respectively. Alcohol-induced weight gain inefficiency in metabolism has previously been studied and explained by a variety of different biochemical and physiological mechanisms. One possible pathway of energy wastage may occur due to ethanol futile cycling from ethanol to acetaldehyde through the microsomal ethanol oxidation system pathway, and simultaneously from acetaldehyde to ethanol via the ADH pathway. This futile cycle represents a net loss of 6 ATP/cycle, corresponding to the loss of two reducing equivalents (NADH and NADPH). 1H NMR spectroscopy was used to test for this cycling in blood extracts after administration of 1,1-2 H2 ethanol. No futile cycling was detected either during the initial 2 weeks of feeding or after the entire feeding period. 相似文献
6.
Molecular basis of essential fructosuria: molecular cloning and mutational analysis of human ketohexokinase (fructokinase) 总被引:2,自引:0,他引:2
Bonthron David T.; Brady Nlcola; Donaldson lain A.; Steinmann Beat 《Human molecular genetics》1994,3(9):1627-1631
Essential fructosuria is one of the oldest known inborn errorsof metabolism. It is a benign condition which is believed toresult from deficiency of hepatic fructokinase (ketohexokinase,KHK, E.C.2.7.1.3). This enzyme catalyses the first step of metabolismof dietary fructose, conversion of fructose to fructose-1-phosphate.Despite the early recognition of this disorder, the primarystructure of human KHK and the molecular basis of essentialfructosuria have not been previously defined. In this report,the isolation and sequencing of full-length cDNA clones encodinghuman ketohexokinase are described. Alternative mRNA speciesand alternative KHK isozymes are produced by alternative polyadenylationand splicing of the KHK gene. The KHK proteins show a high levelof sequence conservation relative to rat KHK. Direct evidencethat mutation of the KHK structural gene is the cause of essentialfructosuria was also obtained. In a well-characterized family,in which three of eight siblings have fructosurla, all affectedindividuals are compound heterozygotes for two mutations Gly40Argand Ala43Thr. Both mutations result from G 相似文献
7.
Marcelo Miranda MD Claudia Castiglioni MD Beat M. Frey MD Martin Hergersberg PhD Adrian Danek MD Hans H. Jung MD 《Movement disorders》2007,22(9):1358-1361
The X‐linked McLeod neuroacanthocytosis syndrome strongly resembles Huntington's disease and has been reported in various countries world‐wide. Herein, we report two Chilean brothers with predominant psychiatric features at disease onset including schizophrenia‐like psychosis and obsessive compulsive disorder. Molecular genetic analysis revealed a small deletion in the XK gene (938‐942delCTCTA), which has been already described in a North American patient of Anglo‐Saxon descent and a Japanese family, presenting with seizures, muscle atrophy or chorea yet absence of psychiatric features. These findings argue against a founder effect and indicate a profound phenotypic variability associated with the 938‐942delCTCTA deletion. Our report supports the inclusion of McLeod syndrome in the differential diagnosis of Huntington's disease as well as acute psychosis in male subjects. © 2007 Movement Disorder Society 相似文献
8.
9.
10.
Urs Brägger Urs Häfeli Beat Huber Christoph H. F. Hämmerle Niklaus P. Lang 《Clinical oral implants research》1998,9(4):218-224
In most of the studies on long-term radiographic evaluations of crestal bone levels adjacent to dental implants, no baseline radiographs taken immediately post-surgically had been obtained.The aim of this study was to test the reproducibility of a simple radiographic method for linear measurements of changes in bone levels and to evaluate changes in crestal bone levels adjacent co non-submerged ITI® implants 1 year following the surgical procedure. From 128 patients enrolled in a clinical and radiographic longitudinal study 40 patients also had radiographs taken immediately postsurgically. They were, however, not obtained as “identical” images. The radiographs were mounted onto slides and projected on a screen. Mesially and distally from 57 implants triplicate linear measurements of the distance implant shoulder to bone crest were taken, using known dimensions of the implants as internal reference distances. The median difference of 213 (out of 228 possible) duplicate measurements was 0.00 mm (ranging from ?1.72 mm to +1.47 mm when comparing the second co the third reading). Some 81% of the double measurements were within ±0.5 mm and the precision was 0.30 mm. In the immediate postoperative radiographs the median mesial bone level was located at 2.07 mm (distally 2.19 mm) from the implant shoulder. A statistically significant amount of bone loss in the first year was observed mesially (median=?0.78 mm) and distally (0.85 mm)(Wilcoxon matched pairs signed rank test ±0.001). No statistically significant influence of the implant location, the implant length, type of the implant (screw; cylinder) was observed (Kruskal-Wallis P>0.05).The age of the patients was not correlated significantly to the amount of bone loss observed. In conclusion, methodological limitations existed when evaluating linear bone changes in non-identical radiographs using reference dimensions of the implants. The amount of postsurgical bone loss estimated in other studies was confirmed when using an immediate postoperative radiograph as a baseline. 相似文献