全文获取类型
收费全文 | 16884篇 |
免费 | 739篇 |
国内免费 | 134篇 |
专业分类
耳鼻咽喉 | 107篇 |
儿科学 | 418篇 |
妇产科学 | 244篇 |
基础医学 | 2017篇 |
口腔科学 | 267篇 |
临床医学 | 939篇 |
内科学 | 4343篇 |
皮肤病学 | 570篇 |
神经病学 | 1229篇 |
特种医学 | 1015篇 |
外科学 | 2862篇 |
综合类 | 65篇 |
一般理论 | 3篇 |
预防医学 | 414篇 |
眼科学 | 294篇 |
药学 | 1141篇 |
中国医学 | 28篇 |
肿瘤学 | 1801篇 |
出版年
2023年 | 82篇 |
2022年 | 157篇 |
2021年 | 315篇 |
2020年 | 215篇 |
2019年 | 226篇 |
2018年 | 299篇 |
2017年 | 291篇 |
2016年 | 353篇 |
2015年 | 359篇 |
2014年 | 483篇 |
2013年 | 578篇 |
2012年 | 848篇 |
2011年 | 958篇 |
2010年 | 624篇 |
2009年 | 529篇 |
2008年 | 935篇 |
2007年 | 1007篇 |
2006年 | 1003篇 |
2005年 | 1039篇 |
2004年 | 951篇 |
2003年 | 899篇 |
2002年 | 995篇 |
2001年 | 302篇 |
2000年 | 321篇 |
1999年 | 349篇 |
1998年 | 297篇 |
1997年 | 235篇 |
1996年 | 238篇 |
1995年 | 202篇 |
1994年 | 159篇 |
1993年 | 157篇 |
1992年 | 233篇 |
1991年 | 209篇 |
1990年 | 222篇 |
1989年 | 199篇 |
1988年 | 179篇 |
1987年 | 163篇 |
1986年 | 156篇 |
1985年 | 154篇 |
1984年 | 124篇 |
1983年 | 74篇 |
1982年 | 60篇 |
1981年 | 63篇 |
1980年 | 61篇 |
1979年 | 62篇 |
1978年 | 37篇 |
1977年 | 33篇 |
1976年 | 32篇 |
1975年 | 30篇 |
1969年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Kazuhiko Sonoyama Haruaki Ninomiya Osamu Igawa Yasuhiro Kaetsu Yoshiyuki Furuse Toshihiro Hamada Junichiro Miake Peili Li Yasutaka Yamamoto Kazuhide Ogino Akio Yoshida Shin-ichi Taniguchi Yasutaka Kurata Satoshi Matsuoka Toshio Narahashi Goshi Shiota Yoshihisa Nozawa Hiroaki Matsubara Masatsugu Horiuchi Yasuaki Shirayoshi Ichiro Hisatome 《Hypertension research》2006,29(11):923-934
We examined the effects of angiotensin II (Ang II) on inward rectifier K+ currents (IK1) in rat atrial myocytes. [125I]Ang II-binding assays revealed the presence of both Ang II type 1 (AT1) and type 2 (AT2) receptors in atrial membrane preparations. Ang II inhibited IK1 in isolated atrial myocytes with an IC50 of 46 nmol/l. This inhibition was abolished by the AT, antagonist RNH6270 but not at all by the AT2 antagonist PD123319. Treatment of cells with pertussis toxin or a synthetic decapeptide corresponding to the carboxyl-terminus of Gialpha-3 abolished the inhibition by Ang II, indicating the role of a Gi-dependent signaling pathway. Accordingly, Ang II failed to inhibit IK1 in the presence of forskolin, dibutyryl-cAMP or protein kinase A catalytic subunits. In spite of the increased binding capacities for [125I]Ang II, Ang II failed to affect IKI in cells from spontaneously hypertensive rats (SHR). AT, immunoprecipitation from atrial extracts revealed decreased amounts of Gialpha-2 and Gialpha-3 proteins associated with this receptor in SHR as compared with controls. The reduced coupling of AT, with Gialpha. proteins may underlie the unresponsiveness of atrial IK1 to Ang II in SHR cells. 相似文献
42.
Osamu Kikuchi Hiroyuki Murai Koji Ikezoe Masakazu Kawajiri Yasumasa Ohyagi Emiko Isogai Jun-ichi Kira 《Clinical neurology》2004,44(4-5):299-302
A 58-year-old woman suffered from stiffness, swelling, rubor and muscle pain in the extremities one month after she climbed a mountain in Kyushu, an island in southern Japan. On admission, mild proximal weakness was present in the extremities. Her range of motion in the extremities was limited due to firm skin and subcutaneous stiffness which was similar to scleroderma. She showed peripheral blood eosinophilia and hypergammaglobulinemia as well as a high erythrocyte sedimentation rate. An IgM antibody against Borrelia afzelii was positive. MRI of the skeletal muscles demonstrated enhancing fascia around the biceps brachii muscle, and a biopsy specimen revealed perivascular infiltration of mononuclear cells within the hypertrophic fascia. Eosinophilic infiltration was absent. We treated the patient with prednisolone, doxycycline and amoxicillin, which alleviated the symptoms. This is the first report to show that Borrelia afzelii was involved in eosinophilic fasciitis. 相似文献
43.
44.
We report a 10-year-old Down syndrome patient who developed dystonia, choreoathetosis, dysarthria, and dysphagia beginning with hemiparesis. Cranial computed tomography disclosed bilateral calcification in the globus pallidus which resembled a sign of premature aging. Conversely, the clinical course and magnetic resonance imaging findings resembled those of Hallervorden-Spatz syndrome. 相似文献
45.
Summary Changes occurring in serotonin neurons during hyperthermia-induced convulsions were examined by means of a modified immunohistochemical method. All mice (8–12 weeks of age) exposed to the temperature of 50°C had convulsions, showing a generalized tonic and/or clonic pattern. Immediately after the convulsions, the animals were perfused transcardially with a fixative. A significant reduction in serotonin immunoreactivity was observed in the neostratum (caudate-putamen complex) of the mice which had hyperthermia-induced seizures, while the serotonin immunoreactivity remained unchanged in the neocortex and paleostriatum. These results suggest that serotonin may be an important mediator in the mechanism of hyperthermia-induced convulsions or that the susceptibility of serotonin neurons to a convulsive state is greatest in the neostriatum.Supported in part by Grant No. 86-05 from the National Center for Nervous, Mental and Muscular Disorders (NCNMMD) of the Ministry of Health and Welfare and Grant No. 62770677 from the Ministry of Education, Science and Culture, Japan 相似文献
46.
MRI and SPECT findings in amyotrophic lateral sclerosis 总被引:1,自引:0,他引:1
Summary MRI was performed in 21 patients and single photon emission computed tomography (SPECT) withN-isopropyl-p-123I iodoamphetamine in 16 patients, to visualize upper motor neurone lesions in amyotrophic lateral sclerosis. T2-weighted MRI revealed high signal along the course of the pyramidal tract in the internal capsule and cerebral peduncle in 4 of 21 patients. SPECT images were normal in 4 patients, but uptake was reduced in the cerebral cortex that includes the motor area in 11. 相似文献
47.
Katsumi Kimura Naotaka Fujita Yutaka Noda Go Kobayashi Kei Ito Jun Horaguchi Toshiki Sugawara Osamu Takasawa 《Digestive endoscopy》2004,16(1):54-57
Clinical diagnosis of chronic cholecystitis is made based on diffuse hyperechoic thickening of the gallbladder wall as shown by ultrasonographic examination. We herein report three cases of chronic cholecystitis showing localized hypoechoic thickening of the gallbladder wall that mimicked gallbladder cancer by ultrasonography. Histologically, hypertrophy of the muscularis propria was a common characteristic finding in these three patients. A smooth surface of the inner hypoechoic layer of the thickened wall was considered to be a reliable finding in the differential diagnosis between this type of chronic cholecystitis and gallbladder cancer. 相似文献
48.
49.
Recent progress in diagnosis of early colorectal cancer] 总被引:1,自引:0,他引:1
Osamu Tsuruta 《Nihon Shokakibyo Gakkai zasshi》2004,101(5):477-485
50.
Osamu Mori Minoru Miyasato Tadashi Karashima Takashi Hashimoto 《The Journal of dermatology》1998,25(8):497-502
Previous studies using primary monolayer cultures of epithelial cells from the involved epidermis of patients with mammary and extramammary Paget's disease investigated whether Paget cells proliferate as other malignant cells do. Although epithelial monolayers from the involved skin were maintained for approximately 45 days, no permanent cell lines were established. The proportion of carcinoembryonic antigen (CEA)-positive cells did not increase in the long-term cultures. Herein, we report studies of whether there is a real reduction of Paget cell numbers or if this is merely a decrease in the expression of CEA by the cells. Furthermore, we investigated whether Paget cells survive longer when cultured free from any potential inhibitory keratinocytes or other epidermal cells. Skin samples were obtained from one patient with mammary Paget's disease and three with extramammary Paget's disease; epidermal cells were cultured in vitro. An enrichment of Paget cells was carried out from the cultured epidermal cells by combining an anti-epithelial membrane antigen monoclonal antibody, binding to immunobeads, and density gradient centrifugation in Nycodenz. The separated cells were re-cultured in Keratinocyte-SFM serum-free media. The proportion of CEA-positive cells did not increase in the cultures, and the purified cells did not show any increase in survival times compared to the non-purified cultured cells. These results suggest that the decrease of CEA-positive cells noted during culture results from a decline in expression of CEA in the Paget cells. Paget cells in the involved epidermis do not proliferate significantly and thus differ from many other malignant cells. 相似文献