全文获取类型
收费全文 | 7248篇 |
免费 | 506篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 123篇 |
儿科学 | 189篇 |
妇产科学 | 191篇 |
基础医学 | 947篇 |
口腔科学 | 372篇 |
临床医学 | 557篇 |
内科学 | 1805篇 |
皮肤病学 | 162篇 |
神经病学 | 497篇 |
特种医学 | 313篇 |
外科学 | 858篇 |
综合类 | 34篇 |
一般理论 | 3篇 |
预防医学 | 632篇 |
眼科学 | 100篇 |
药学 | 533篇 |
中国医学 | 44篇 |
肿瘤学 | 416篇 |
出版年
2023年 | 44篇 |
2022年 | 144篇 |
2021年 | 228篇 |
2020年 | 136篇 |
2019年 | 227篇 |
2018年 | 275篇 |
2017年 | 174篇 |
2016年 | 213篇 |
2015年 | 247篇 |
2014年 | 307篇 |
2013年 | 350篇 |
2012年 | 513篇 |
2011年 | 510篇 |
2010年 | 287篇 |
2009年 | 259篇 |
2008年 | 390篇 |
2007年 | 385篇 |
2006年 | 318篇 |
2005年 | 294篇 |
2004年 | 273篇 |
2003年 | 258篇 |
2002年 | 223篇 |
2001年 | 192篇 |
2000年 | 170篇 |
1999年 | 178篇 |
1998年 | 71篇 |
1997年 | 66篇 |
1996年 | 39篇 |
1995年 | 39篇 |
1994年 | 31篇 |
1993年 | 27篇 |
1992年 | 78篇 |
1991年 | 82篇 |
1990年 | 81篇 |
1989年 | 40篇 |
1988年 | 38篇 |
1987年 | 58篇 |
1986年 | 46篇 |
1985年 | 57篇 |
1984年 | 40篇 |
1983年 | 33篇 |
1980年 | 20篇 |
1979年 | 38篇 |
1978年 | 20篇 |
1975年 | 24篇 |
1974年 | 27篇 |
1973年 | 26篇 |
1972年 | 19篇 |
1969年 | 23篇 |
1968年 | 19篇 |
排序方式: 共有7776条查询结果,搜索用时 31 毫秒
991.
Bernard-Soulier syndrome (BSS) is a congenital autosomal recessive bleeding disorder characterised by giant platelets, the lack of thrombocytopenia or a moderate one, prolongation of skin bleeding time, and absent platelet aggregation in response to ristocetin. We report a case of BSS revealed by major neonatal thrombocytopenia. A newborn was admitted for thrombocytopenic purpura initially believed to be due to a maternal auto-immune thrombocytopenia. Because of the persistence of the thrombopenia till the age of 7 months despite therapy by corticosteroids and immunoglobulins, and because of the detection of anti-1b antiplatelets antibodies after transfusion, BSS diagnosis was evoked. In such a situation of major thrombocytopenia, the main therapeutic measure is prevention. Therapy by DDAVP may be used after the age of 3 years in situations of high haemorrhagic risk. This case report underlines the importance of a precise diagnosis in front of a maternal thrombocytopenia and the possibility of antenatal diagnosis of BSS. 相似文献
992.
E. Carmina G. Di Fede N. Napoli G. Renda G. Vitale C. Lo Pinto D. Bruno R. Malizia G. B. Rini 《Calcified tissue international》2003,74(1):68-71
We studied bone mass and metabolism in 30 adult women (age 28.5 ± 1.3) with thalassemia major (TM) and evaluated whether prolonged hormone replacement therapy (HRT) was able to optimize bone accrual. TM patients had reduced bone mass, increased bone turnover and lower serum gonadotropin and estradiol levels compared with 10 normal women of similar age. A significant correlation was found between bone mass and sex hormone levels. Six TM patients with normal ovarian function had normal bone turnover markers and modestly low bone mass (lumbar spine –1.29 ± 0.31; femoral neck –0.60±0.21; Z-score). The other 24 TM women were hypogonadic and had significantly lower bone mass for age (lumbar spine –2.35 ± 0.2, femoral neck –1.83 ± 0.2) and increased bone turnover relative to eugonadal women. Of the hypogonadal patients, 13 had taken HRT since age 15 ± 1 years, but their bone mass and turnover markers were not different than untreated hypogonadal patients. In conclusion, while hypogonadism negatively affects bone mass acquisition in adult TM women, HRT at the standard replacement doses is not sufficient to secure optimal bone accrual. 相似文献
993.
994.
The hopelessness theory of depression hypothesizes the existence of a hopelessness subtype of depression, characterized by its specific cause, symptoms, course, therapy, and prevention. Data from depressed inpatient adolescents (N = 160) were used to evaluate (a) the relation between hopelessness and the hypothesized symptoms of hopelessness depression; and (b) the latent structure of the relation between hopelessness and the symptoms of hopelessness depression, to test for a hopelessness depression taxon (i.e., subtype). Results suggest that hopelessness was related to the hypothesized symptoms of hopelessness depression, treated singly and in combination. However, results from the application of Meehl and Yonce's (1994) MAMBAC taxometric analytic procedure, using hopelessness and the symptoms of hopelessness depression as taxonic indicators, did not support the existence of a hopelessness depression latent taxon. These results suggest that hopelessness depression may best be conceptualized as a dimension or continuum versus a category or subtype. 相似文献
995.
996.
Inhibition of human scleral fibroblast proliferation with heparin 总被引:10,自引:0,他引:10
P J Del Vecchio R Bizios L A Holleran T K Judge G L Pinto 《Investigative ophthalmology & visual science》1988,29(8):1272-1276
Proliferation of fibroblasts is a serious problem in ocular trauma and surgical wound healing. Depending on the location of the injury, the growth of fibroblasts can lead to different problems. In glaucoma filtering surgery, fibroblast proliferation may contribute to scar tissue formation and premature wound closure. Fibroblastic growth in proliferative vitreoretinopathy may lead to the formation of preretinal membranes, which can contract, causing retinal detachment. In an effort to find a more effective method of inhibiting ocular fibroblast proliferation, we have investigated the effect of heparin, a sulfated polysaccharide, on the proliferation of fibroblasts obtained from the sclera of donor eyes. Heparin inhibits the incorporation of 3H-thymidine in a dose-dependent manner in the presence of fetal bovine serum (FBS). This inhibition is partially reversed by endothelial cell growth factor (ECGF). The heparin antagonist protamine sulfate causes a reversal of heparin inhibition and, in some instances, a significant increase in 3H-thymidine incorporation compared to serum controls. Heparin was equally effective in inhibiting cell proliferation in control and heparin-protamine sulfate-pretreated medium. These results were apparently unrelated to a direct toxic effect on cells, as a Trypan Blue exclusion assay showed no significant difference in viability when heparin treated cells were compared to control cells. Direct cell counts showed that heparin was effective in inhibiting cell proliferation over a long time period, but only if it was reinstilled every 2 days. Heparin treatment shows promise as a method for controlling fibroblast proliferation in the eye. 相似文献
997.
I I Kricheff R S Pinto R T Bergeron N Cohen 《AJNR. American journal of neuroradiology》1980,1(1):57-63
Disenchantment with the limitations, and in some cases the morbidity, of currently used radiologic techniques for the demonstration or exclusion of small acoustic neuromas prompted development of an examination using small amounts of intrathecal air and computed tomography (CT). A prospective study was designed to evaluate air CT cisternography/canalography, wherein patients with the clinical symptoms of acoustic neuroma but with negative enhanced CT, were evaluated by metrizamide CT cisternography followed by air CT cisternography/canalography. Pantopaque cisternography was then performed as a control procedure. Four patients had surgically proven tumors. In 13 others, accumulated evidence indicated no tumors were present. Results suggest that air-CT cisternography is superior to all other diagnostic methods in defining small acoustic neuromas, and may exclude an intracanalicular lesion without the potential hazards of Pantopaque cisternography or high concentration metrizamide tomocisternography. With air-CT cisternography, there were no errors in this series. 相似文献
998.
Director Guillermo A. Herrera Heleno Pinto de Moraes 《Virchows Archiv : an international journal of pathology》1984,403(4):361-376
Summary Thirteen soft tissue neurogenic sarcomas from twelve patients with neurofibromatosis (Von Recklinghausen's disease) were ultrastructurally examined. Electron microscopic studies revealed a wide spectrum of morphological manifestations varying from schwannian to fibroblastic, histiocytic, fibrohistiocytic and relatively undifferentiated cellular proliferations. A similar variation on light microscopic appearances has been previously reported in these neurogenic sarcomas. Neurogenic sarcomas occurring in patients with neurofibromatosis (Von Recklinghausen's disease), represent a heterogenous group of neoplasms with various patterns of differentiation identified ultrastructurally. The morphologic expressions of these neurogenic neoplasms can be conceptualized as a disorderly growth of the various peripheral nerve cellular components, or, as has been previously suggested, as a result of the multipotential nature and metaplastic ability of Schwann cells. S-100 protein immunohistochemistry was only positive in those neoplasms ultrastructurally proven to represent schwannian cellular proliferations.This study serves to document the range of fine structure that may be found in neurogenic sarcomas, to correlate the ultrastructural findings with the light microscopic appearance of these tumors, to determine the specificity of the electron microscopic findings, and immunohistochemistry for S-100 protein and assess their possible value in differential diagnosis. 相似文献
999.
1000.
A Pinto S L Rasmussen T M Campbell W M Lester 《Canadian Medical Association journal》1984,131(3):215-217
An elderly man had a 10-year history of multiple pulmonary nodules that he had refused to have investigated. He died of a ruptured abdominal aortic aneurysm. At autopsy the nodules were shown to consist of amyloid. There was no evidence of systemic amyloidosis. 相似文献