全文获取类型
收费全文 | 273838篇 |
免费 | 53227篇 |
国内免费 | 7855篇 |
专业分类
耳鼻咽喉 | 3949篇 |
儿科学 | 8449篇 |
妇产科学 | 2285篇 |
基础医学 | 52430篇 |
口腔科学 | 11636篇 |
临床医学 | 26300篇 |
内科学 | 47164篇 |
皮肤病学 | 8274篇 |
神经病学 | 26957篇 |
特种医学 | 9477篇 |
外国民族医学 | 118篇 |
外科学 | 28648篇 |
综合类 | 25723篇 |
现状与发展 | 48篇 |
一般理论 | 8篇 |
预防医学 | 12428篇 |
眼科学 | 4820篇 |
药学 | 21937篇 |
30篇 | |
中国医学 | 6636篇 |
肿瘤学 | 37603篇 |
出版年
2024年 | 364篇 |
2023年 | 2469篇 |
2022年 | 4313篇 |
2021年 | 7525篇 |
2020年 | 11004篇 |
2019年 | 15918篇 |
2018年 | 15562篇 |
2017年 | 17057篇 |
2016年 | 16466篇 |
2015年 | 17139篇 |
2014年 | 20016篇 |
2013年 | 21271篇 |
2012年 | 18949篇 |
2011年 | 20061篇 |
2010年 | 17027篇 |
2009年 | 13424篇 |
2008年 | 14431篇 |
2007年 | 13137篇 |
2006年 | 12156篇 |
2005年 | 11265篇 |
2004年 | 10276篇 |
2003年 | 9004篇 |
2002年 | 7871篇 |
2001年 | 6433篇 |
2000年 | 4688篇 |
1999年 | 3297篇 |
1998年 | 2932篇 |
1997年 | 2674篇 |
1996年 | 2404篇 |
1995年 | 2095篇 |
1994年 | 1848篇 |
1993年 | 1540篇 |
1992年 | 1253篇 |
1991年 | 1188篇 |
1990年 | 909篇 |
1989年 | 854篇 |
1988年 | 791篇 |
1987年 | 631篇 |
1986年 | 591篇 |
1985年 | 781篇 |
1984年 | 697篇 |
1983年 | 486篇 |
1982年 | 513篇 |
1981年 | 412篇 |
1980年 | 343篇 |
1979年 | 258篇 |
1978年 | 179篇 |
1977年 | 139篇 |
1976年 | 105篇 |
1975年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
81.
Ken Igawa Ryuji Maruyama Ichiro Katayama Kiyoshi Nishioka 《The Journal of dermatology》1997,24(5):328-331
A 72-year-old fisherman who was positive for the HCV antibody developed an annular, erythematous, infiltrated lesions on sun-exposed areas. The lesions were diagnosed as annular elastolytic giant cell granuloma both clinically and histologically. Topical corticosteroid and cryotherapy with liquid nitrogen for several months failed to improve the lesions. We then started dapsone, a known anti-oxidant, at 50 mg/day. A month later, the margins of the erythematous lesions faded, and the infiltration gradually decreased. No recurrence has been observed for one year after the start of the therapy. Anti-oxidative therapy appears to be effective for annular elastolytic giant cell granuloma and could be an alternate therapy for refractory granulomatous disease. 相似文献
82.
Reyna O. Calderon B. Maggio T. J. Neuberger G. H. Devries 《Journal of neuroscience research》1993,34(2):206-218
The axolemma membrane forms a stable and reproducible monomolecular layer at the air-aqueous interface. The major lipids and proteins are present in this monolayer in molar ratios similar to the original membrane. Acetylcholinesterase and Na-K-ATPase activities are preserved in the monolayer to levels of 64% and 25%, respectively. The total lipid fraction forms a homogeneously mixed phase. The presence of proteins in the monolayer introduces surface inhomogeneties. Among other features, this is revealed by the presence of two values of lateral pressure at which the monolayer shows partial or total collapse: a broad partial collapse at surface pressures between 13 to 30 mN/m and a sharp collapse point at 46 mN/m. The average molecular areas, the broad collapse point, and the variation of the surface potential per molecule suggest the relocation of protein components at surface pressures between 13 to 30 mN/m. The behavior is consistent with the extrusion and exposure of proteins toward the aqueous medium that depends on the lateral pressure. Schwann cells grown on coverslips coated with axolemma monolayers at 13 mN/m (beginning of the broad collapse) and 34 mN/m (above the broad collapse) recognize the difference in the surface organization of axolemma caused by the lateral pressure which affects their proliferation, morphology, and spatial pattern of organization. Our results show for the first time that response of Schwann cells depends on the intermolecular organization of the axolemma surface with which they interact. These results suggest that the local expression of putative surface molecules of axolemma that may mediate membrane recognition and the signalling of morphological and proliferative changes can be modulated by long range supramolecular properties. © 1993 Wiley-Liss, Inc. 相似文献
83.
84.
Geste antagonistes, or sensory tricks, are well described in focal dystonia affecting the neck, hand, and face. Improvement in dystonic movements is typically maintained while the trick is performed, but disappears when the geste ends. We investigated the phenomenological features of geste antagoniste maneuvers in 19 patients with idiopathic lower cranial dystonia who were prospectively evaluated over a period of 6 years. Of the 19, 10 were men, mean age of onset was 49.8 years, and the most commonly involved lower cranial area was the jaw (10 patients). In most patients, dystonia was task-specific. Taking advantage of the improvement with a sensory geste, we manufactured oral appliances that mimicked the geste in 8 patients, and 3 continue to use it. 相似文献
85.
AIMS: To determine the most appropriate regression models to use when assessing risk factors for severe hypoglycaemia and to investigate the impact of model misspecification and its clinical implications. METHODS: A total of 1229 children with Type 1 diabetes (mean age 11.7 years sd 4.1), of which 605 (49.2%) were males, were studied. Prospective assessment of severe hypoglycaemia (an event leading to loss of consciousness or seizure) was made over the 9-year period, 1992-2001. Patients were seen every 3 months and episodes of hypoglycaemia along with clinical data were recorded. Over 70% of children never experienced a severe hypoglycaemic event. Data were analysed using the Poisson regression, negative binomial, zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models. The over-dispersion and likelihood ratio statistics were calculated and the analytical methods compared. RESULTS: The Poisson regression model did not fit the data well. The negative binomial and the zero inflated Poisson and negative binomial models fitted the data better than Poisson. CONCLUSIONS: The commonly used Poisson regression models to analyse hypoglycaemia epidemiology may lead to biased parameter estimates and incorrect determination of risk factors for hypoglycaemia. We recommend the use of the negative binomial or zero inflated models to examine any risk factors associated with severe hypoglycaemia. Careful consideration must be given to the interpretation of hypoglycaemia surveys and their analysis. 相似文献
86.
87.
The effect of the barbiturate T2000 (1,3-dimethoxymethyl-5,5-diphenyl-barbituric acid; DMMDPB) on essential tremor, given in twice daily doses of 400 and 300 mg, was assessed in two brief, randomized, placebo-controlled, parallel-group, double-blinded, single-center trials in 12 and 22 patients, respectively. These trials represent the first clinical use of T2000 for a specific indication. The primary endpoint was the change in the mean scores of the treated and control groups based on the Fahn-Tolosa-Marin tremor scale. In the first study of 12 patients treated with 400 mg or placebo twice daily for 14 days, the mean change from baseline at day 14 was 19.3 (P < 0.0001) in the treated group and 9.0 (P = 0.0121) in the control group. Using a two-factor mixed ANOVA model to evaluate within group and between group changes, the effect of T2000 was significantly different from that of the placebo group (P = 0.03). In the second study of 22 patients treated with 300 mg of T2000 or placebo twice daily for 20 days, statistically significant changes were seen in treated patients compared to baseline, but the ANOVA model did not demonstrate a significant treatment effect of T2000 compared to placebo. When the treated groups from each study are compared, the 800-mg daily group is significantly different from the 600-mg daily group (P = 0.02). Some treated patients in each study, but no placebo patients, experienced marked improvement. These results support further evaluation of T2000 in the treatment of essential tremor. 相似文献
88.
Kazumasa Miyake Atsushi Tatsuguchi Mikiko Tachibana Masanobu Kusunoki Yoko Shinji Kei Shinoki Tetsuro Hiratsuka Kazuhiro Nagata Hitoshi Nishigaki Seiji Futagami Ken Wada Taku Tsukui Toshiro Yoshiyuki Akira Tokunaga Takashi Tajiri Choitsu Sakamoto 《Digestive endoscopy》2004,16(2):172-175
A 52‐year‐old Japanese woman who presented with gastrointestinal (GI) bleeding underwent a proximal gastrectomy for a gastrointestinal stromal tumor (GIST) with a foveolar hyperplasia at the apex of the tumor, 4.5 cm in size, located in the upper body of the stomach. Although GIST are often asymptomatic and are found only incidentally, clinical symptoms such as bleeding, abdominal pain, or obstruction, occasionally lead to a premorbid diagnosis. When submucosal tumors present GI bleeding, the source of the bleeding usually is an ulceration of the mucosa over the tumor. However, in the present study, it was thought that the bleeding originated from the region of foveolar hyperplasia. 相似文献
89.
T. Eiwegger N. Rigby L. Mondoulet H. Bernard M.-T. Krauth A. Boehm E. Dehlink P. Valent J. M. Wal E. N. C. Mills Z. Szépfalusi 《Clinical and experimental allergy》2006,36(10):1281-1288
BACKGROUND: The process of gastro-duodenal digestion may play a role in determining the allergenic properties of food proteins. The sensitizing and allergenic potential of digestion products of highly degraded allergens, such as the major peanut allergen Ara h 1, is currently under debate. We evaluated the effect of in vitro gastro-duodenal digestion of Ara h 1 on T cell reactivity and basophil histamine release. METHODS: An in vitro model of gastro-duodenal digestion was used to investigate changes in the allergenic properties of Ara h 1 using in vitro assays monitoring T cell reactivity (proliferation, cytokine production) and histamine release of basophils from peanut allergic individuals. The digestion process was monitored using an SDS-PAGE gel. RESULTS: In vitro gastric digestion led to rapid degradation of Ara h 1 into small fragments M(r) L5600. Gastric digestion did not affect the ability of Ara h 1 to stimulate cellular proliferation. Gastro-duodenal digestion significantly reduced its ability to stimulate clonal expansion (P<0,05; Wilxocon's signed rank test). The Th-2 type cytokine polarization of T cells from peanut allergic donors (IFN-gamma/IL-13 ratio and IFN-gamma/IL-4 ratio of CFSE(low) CD4(+) T cells) remained unchanged regardless of the level of digestion. Histamine release of basophils from peanut allergic individuals was induced to the same extent by native Ara h 1 and its digestion products. CONCLUSION: Gastro-duodenal digestion fragments of Ara h 1 retain T cell stimulatory and IgE-binding and cross-linking properties of the intact protein. 相似文献
90.