全文获取类型
收费全文 | 9450篇 |
免费 | 462篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 97篇 |
儿科学 | 153篇 |
妇产科学 | 250篇 |
基础医学 | 1295篇 |
口腔科学 | 214篇 |
临床医学 | 601篇 |
内科学 | 2056篇 |
皮肤病学 | 226篇 |
神经病学 | 804篇 |
特种医学 | 553篇 |
外科学 | 1681篇 |
综合类 | 23篇 |
一般理论 | 1篇 |
预防医学 | 249篇 |
眼科学 | 132篇 |
药学 | 583篇 |
中国医学 | 12篇 |
肿瘤学 | 1011篇 |
出版年
2022年 | 106篇 |
2021年 | 176篇 |
2020年 | 103篇 |
2019年 | 122篇 |
2018年 | 151篇 |
2017年 | 121篇 |
2016年 | 130篇 |
2015年 | 164篇 |
2014年 | 210篇 |
2013年 | 284篇 |
2012年 | 441篇 |
2011年 | 462篇 |
2010年 | 241篇 |
2009年 | 202篇 |
2008年 | 408篇 |
2007年 | 412篇 |
2006年 | 401篇 |
2005年 | 420篇 |
2004年 | 384篇 |
2003年 | 428篇 |
2002年 | 435篇 |
2001年 | 336篇 |
2000年 | 394篇 |
1999年 | 264篇 |
1998年 | 95篇 |
1997年 | 79篇 |
1996年 | 85篇 |
1995年 | 72篇 |
1994年 | 76篇 |
1993年 | 59篇 |
1992年 | 221篇 |
1991年 | 225篇 |
1990年 | 197篇 |
1989年 | 241篇 |
1988年 | 204篇 |
1987年 | 212篇 |
1986年 | 181篇 |
1985年 | 152篇 |
1984年 | 97篇 |
1983年 | 79篇 |
1982年 | 47篇 |
1979年 | 77篇 |
1978年 | 67篇 |
1977年 | 49篇 |
1975年 | 48篇 |
1974年 | 52篇 |
1972年 | 58篇 |
1971年 | 55篇 |
1969年 | 45篇 |
1968年 | 49篇 |
排序方式: 共有9941条查询结果,搜索用时 15 毫秒
31.
Summary In an effort to achieve a simple and less invasive method for the treatment of chronic subdural haematoma, replacement of the haematoma with oxygen by percutaneous subdural tapping was employed in 36 patients. This study was conducted on 23 haematomas in 20 patients, whose computed tomography (CT) scans immediately following the treatment were available for evaluation, with particular regard to distinguishing between their findings and those seen with tension pneumocephalus. The CT features werde divided into two patterns according to the location of oxygen; a convexity type (19 haematomas) and an interhemispheric type (4 haematomas). Analysis of the CT appearances revealed the oxygen was exclusively confined to the haematoma cavity, distinguishing it from the findings in tension pneumocephalus. This observation indicates the safety of replacement of the haematoma with oxygen when combined with our percutaneuous subdural tapping technique which prevents lesions of the inner haematoma membrane. 相似文献
32.
Yasuo Miyoshi Seigoh Mizumoto MD Hideo Akashi Eiji Kurokawa Hideyuki Mishima Keisuke Iihara Kohji Takami Masayuki Ohue Yukitoshi Aoki 《Surgery today》1990,20(6):711-714
A rare case of jejunal carcinoma coexisting with adenoma, situated 120 cm distal to the ligament of Treitz in a 53 year old
male, is reported herein. We also review cases of adenoma and carcinoma in the jejunum and ileum from the Japanese literature,
and discuss the histogenesis of carcinoma of the jejunum and ileum. 相似文献
33.
Masanori Hisaoka Takatoshi Aoki Hiromi Kouho Hirofumi Chosa Hiroshi Hashimoto 《Skeletal radiology》1997,26(3):191-194
The case of a 49-year-old man with Maffucci’s syndrome, who developed multiple spindle cell hemangioendotheliomas, is presented.
The case provides support for recent reports suggesting an association between this peculiar vascular lesion and skeletal
enchondromatosis. 相似文献
34.
Y Shiokawa M Nobunaga T Saito T Sakita T Miwa K Nakamura A Gunji K Aoki 《Ryūmachi》1991,31(5):554-571
35.
β-Adrenergic receptors (βAR) in the medial nuclei of tractus solitarii (m-NTS) and area postrema (AP) may bind to catecholamines released from neurons, whereas only the AP has fenestrated capillaries allowing access to circulating catecholamines. Since varied autonomic responses are seen following βAR activation of the dorsal vagal complex, including the m-NTS and AP, we hypothesized that there might be a cellular basis for varied responses to βAR stimulation that depends pn the differential access to circulating catecholamines. Therefore, we comparatively examined the ultrastructural localization of the βAR in relation to catecholaminergic neurons in these regions. An antibody directed against the C-terminal tail (amino acids 404–418) of hamster β-adrenergic receptor (βAR404) was used in this study. The localization of βAR404 was achieved by the avidin-biotin peroxidase complex (ABC) technique in combination with a pre-embed immunogold labeling method to localize tyrosine hydroxylase (TH), the catecholamine-synthesizing enzyme. Within m-NTS and at subpostremal border, labeling for βAR404 was evident along the intracellular surface of plasma membranes of small, apparently distal, astrocytic processes. Astrocytic processes with βAR404-immunoreactivity formed multiple, thin lamellae around TH-labeled and non-TH neuronal cell bodies and dendrites. βAR404-immunoreactive astrocytes also extended end-feet around blood vessels and surrounded groups of axon terminals that were directly juxtaposed to each other. Some, but not all, of these axons demonstrated TH-immunoreactivity. Fewer βAR404-immunoreactive astrocytes were detected in AP, regardless of their proximity to catecholaminergic processes or blood vessels. The present astrocytic localization of βAR404, together with the earlier, neuronal localization of βAR's third intracellular loop, suggest that the βAR may be substantially different between neurons and astrocytes. The regional difference in the prevalence of βAR404-immunoreactive astrocytes suggests that these receptive sites may either: (i) be preferentially activated by catecholamines released from terminals rather than circulating catecholamines; or (ii) be down-regulated in AP due to blood-born substances, such as catecholamines. The extensive localization of βAR in the border between m-NTS and AP also suggests that catecholaminergic activation of these astrocytes may dictate the degree of diffusion of catecholamines which are of neuronal or vascular origin. The specific localization of βAR404-immunoreactivity to the more distal portions of astrocytes suggests the possibility that astrocytes have restrictive distributions of βAR and that the β-adrenergic activation lead to morphological or chemical changes that are also localized to the distal portions of astrocytes. Additionally, the detection of βAR404 in astrocytes contacting non-TH-immunoreactive neurons suggests the possibility for catecholaminergic modulation of non-catecholaminergic neurons via the activation of astrocytes. 相似文献
36.
37.
The actions of metaraminol on the secretion of fluid and glycoproteins from rat submandibular glands were investigated using phentolamine, propranolol and reserpine. Metaraminol at doses from 1 to 8 mg/kg (i.p.) increased the salivation and the amounts of protein in submandibular saliva in a dose-dependent manner. The salivation induced by metaraminol at 2 mg/kg was inhibited strongly by pretreatment with propranolol, whereas the salivation induced by metaraminol at 8 mg/kg was inhibited strongly by phentolamine. Reserpine inhibited the secretion of fluid caused by both doses of metaraminol. The electrophoretic profiles of saliva evoked by metaraminol at 2 mg/kg revealed two main bands of glycoprotein, I and IV, which originated from the acinus, and the intensities of these bands were decreased by treatment with propranolol, whereas the major band in saliva induced by 8 mg/kg of metaraminol was glycoprotein III, which originated from the granular tubules. The intensity of band III was decreased by pretreatment with phentolamine. These results suggest that metaraminol, at small doses, stimulates mainly the beta-adrenoceptor in the acinus, whereas at large doses, it prominently stimulates the alpha-adrenoceptors in the granular tubules, although metaraminol at small and large doses is able to stimulate alpha- and beta-adrenoceptors in rat submandibular gland. 相似文献
38.
PAF (1 ug/kg) injected intravenously (i.v.) into anesthetized rabbits resulted in marked loss of circulating platelets and leukocytes. Administration of FR-900452 1-methyl-3-(1-(5-methylthiomethyl-6-oxo-3-(2-oxo-3-cyclopenten-1-y lidene)- 2-piperazinyl) ethyl)-2-indolinone, a specific PAF inhibitor, at a dose of 10 mg/kg i.v. with 10 min prior to the PAF injection significantly prevented both changes. On the other hand, PAF has been considered as a mediator of endotoxin shock. Therefore, in order to determine whether endogenous PAF contributes to the occurrence of thrombocytopenia or leukopenia in endotoxin shock, we assessed the effect of FR-900452 on the thrombocytopenia and the leukopenia following bolus i.v. injection of E.coli endotoxin (0.03 mg/kg) in rabbits. As a result, pretreatment with the compound (10 mg/kg, i.v.) significantly reduced the thrombocytopenia at 60 and 180 min after the endotoxin injection. In contrast, FR-900452 did not reduced the leukopenia at any time of after endotoxin. These results indicate that PAF might be involved in the occurrence of thrombocytopenia in rabbit endotoxemia and the contribution of PAF to the leukopenia is much less extent than that to the thrombocytopenia. 相似文献
39.
Y Banya T Abe H Sasaki H Aoki T Fujioka T Akasaka T Kubo T Ohori 《Hinyokika kiyo. Acta urologica Japonica》1986,32(3):454-461
We present a case of primary ureteral carcinoma in the duplicated renal pelvis and ureter diagnosed by transurethral uretero-renoscopy. The case was of a 78-year-old man with the complaint of sudden asymptomatic macrohematuria. An excretory urogram strongly suggested the presence of duplication of the right collecting system, and cystoscopy revealed a gross hematuria from the right ureteral orifice. A retrograde ureteropyelogram revealed incomplete duplication of the right renal pelvis and ureter fused at about the ureter crossing over the iliac vessels, and a polyp-like filling defect in the lower segment of duplicated ureter at about 4 cm from the fusion of the ureters. Transurethral uretero-renoscopy was employed to investigate the filling defect, and a papillary tumor extended into the lower segment of duplicated ureter was revealed. Tumor was resected by a rigid operating instrument under transurethral uretero-renoscopy. The pathological diagnosis was grade I-transitional cell carcinoma of the ureter, so that right total nephroureterectomy with partial cystectomy was carried out subsequently. Surgical specimen after right total nephroureterectomy with partial cystectomy showed no other tumor in the pelvis or ureter macroscopically, and histopathological studies of surgical specimens were no evidence of malignancy. We believe that transurethral uretero-renoscopy significantly increases the diagnostic accuracy in determining the nature of upper urinary tract lesions, and this procedure is indispensable in the diagnosis of ureteral tumors. The present case was the 7th case of primary ureteral carcinoma in the duplicated renal pelvis and ureter in the Japanese literature. 相似文献
40.
K Sagisaka M Noguchi M Funayama Y Aoki 《The Tohoku journal of experimental medicine》1986,150(3):345-351
Immune agglutinin or precipitin loses its reactivity with the corresponding antigen by heating or some chemicals. A. Se group saliva or M group blood stain was sensitized with human IgM anti-A or rabbit IgG anti-M serum, respectively. After being washed with saline, the stains were heated or treated with formalin or 2-mercaptoethanol (2-ME) of various concentrations. The immunoreactivity of the antibodies in the state of immunecomplex was examined by the mixed agglutination or elution test, indicating IgM and IgG antibodies in the state of immunecomplex were proof against heating up to 150 degrees C for 10 min and against formalin and 2-ME of high concentrations. It is considered that IgM and IgG acquire a new property of heat and chemical stability by formation of immunecomplex although they are substantially heat and chemical labile. 相似文献