全文获取类型
收费全文 | 10314篇 |
免费 | 443篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 179篇 |
儿科学 | 213篇 |
妇产科学 | 170篇 |
基础医学 | 1417篇 |
口腔科学 | 255篇 |
临床医学 | 712篇 |
内科学 | 2488篇 |
皮肤病学 | 121篇 |
神经病学 | 845篇 |
特种医学 | 539篇 |
外科学 | 1648篇 |
综合类 | 52篇 |
预防医学 | 361篇 |
眼科学 | 225篇 |
药学 | 618篇 |
中国医学 | 21篇 |
肿瘤学 | 938篇 |
出版年
2023年 | 58篇 |
2022年 | 86篇 |
2021年 | 161篇 |
2020年 | 99篇 |
2019年 | 124篇 |
2018年 | 150篇 |
2017年 | 136篇 |
2016年 | 146篇 |
2015年 | 142篇 |
2014年 | 185篇 |
2013年 | 239篇 |
2012年 | 423篇 |
2011年 | 492篇 |
2010年 | 252篇 |
2009年 | 218篇 |
2008年 | 392篇 |
2007年 | 416篇 |
2006年 | 449篇 |
2005年 | 480篇 |
2004年 | 462篇 |
2003年 | 446篇 |
2002年 | 458篇 |
2001年 | 391篇 |
2000年 | 445篇 |
1999年 | 409篇 |
1998年 | 159篇 |
1997年 | 127篇 |
1996年 | 107篇 |
1995年 | 112篇 |
1994年 | 71篇 |
1993年 | 74篇 |
1992年 | 221篇 |
1991年 | 247篇 |
1990年 | 255篇 |
1989年 | 250篇 |
1988年 | 242篇 |
1987年 | 238篇 |
1986年 | 199篇 |
1985年 | 177篇 |
1984年 | 140篇 |
1983年 | 99篇 |
1982年 | 47篇 |
1981年 | 51篇 |
1979年 | 93篇 |
1976年 | 47篇 |
1974年 | 43篇 |
1972年 | 62篇 |
1971年 | 44篇 |
1970年 | 46篇 |
1969年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 24 毫秒
91.
Makino S Miyamoto T Nakajima S Kabe J Baba M Mikawa H Furusho M Fukuda K Nakagawa T Naitou H 《Allergy》2000,55(2):135-140
BACKGROUND: In Japan in 1993, the Japanese Society of Allergology (JSA) developed guidelines for diagnosis and management of asthma (JGL), which were based on the concept that asthma is a chronic inflammatory disorder of the airway. METHODS: This survey study was intended to investigate the recognition and utilization of JGL among physicians who had treated asthma. The survey comprised two methods: a quantitative mail survey and a qualitative door-to-door survey conducted by trained interviewers. RESULTS: In the mail survey, a total of 1028 physicians responded; 552 members of the JSA and 476 nonmembers. Ninety-four percent of JSA members were aware of adult asthma management guidelines, while 53% of nonmembers were aware of them. Although approximately half of the physicians, both members and nonmembers, found differences between the asthma management policies in JGL and their previous policies, most of them utilized JGL once they read it. In the qualitative door-to-door survey, 80-90% of physicians evaluated JGL as good after they read it. CONCLUSIONS: JGL was recognized and utilized by most JSA members, but only half of nonmember physicians were aware of JGL, although they utilized JGL after they read it. Further action to implement JGL among nonspecialist physicians is needed to improve management of asthma. 相似文献
92.
An improved fixation technique for transmission electron microscopic observation that enables good fixation of all areas of the rat lens was devised. Immersion fixation with 0.1 M phosphate-buffered 1.25% glutaraldehyde at 4 degrees C for 12 hours followed by postosmication produced good results for all areas of the lens--anterior, equatorial, and posterior zones. The technique was particularly suitable for maintenance of the shape of the lens since practically no irregularity, vacuolar degeneration, or expansion of the intercellular spaces was noted. This technique, which requires only a relatively short time, was also useful for the detection of early ultrastructural changes associated with cataract in spontaneously diabetic WBN/Kob rats. We anticipate that our procedure will be widely applied. 相似文献
93.
A rare case of malacoplakia (MKP) of the endometrium in an 88-year-old Japanese woman is presented. By light microscopy, typical Michaelis-Gutmann bodies (M-G bodies) could be identified. Electron microscopic findings revealed M-G bodies in various stages of development. These features suggested that M-G bodies were derived from round electron-dense granules that coalesced to form phagolysosomes. Early-stage M-G bodies were manifested as small, irregular, needle-shaped areas of calcification in phagolysosomes. The present paper reviews 6 cases of endometrial MKP, 5 of which have previously been reported in the literature, and this case being the sixth, to our knowledge. 相似文献
94.
Human leukosialin is among the most abundant sialoglycoproteins found on the surface of cells of the lympho-hematopoietic system. Leukosialin, also known as sialophorin, is involved in T cell proliferation, and its molecular isoform changes upon cellular activation. We show that human leukosialin is identical to the antigens described by the monoclonal antibodies (mAb) G10-2, G19-1 (CD43) and B1B6 (large sialoglycoprotein). This identity was suggested by immunoblot analysis of transformed cell lysates. Further, fibroblasts transfected with the human leukosialin cDNA gain reactivity to these mAb, showing conclusively that molecules recognized by these mAb are determined by the same cDNA. Expression of the leukosialin gene is readily detected on the surface of transfected human and mouse fibroblasts. Immunoblot analysis of the transfectants indicates that processing of the human protein occurs in both species. Alterations of leukosialin expression have been reported in patients with the Wiskott-Aldrich Syndrome (WAS), an X-chromosome-linked immunodeficiency disease. While essentially all of the transfected tumor and primary fibroblasts from normal individuals express the transfected gene on the cell surface, only half of the transfected Wiskott-Aldrich fibroblasts express CD43. Nonetheless, the antigenic pattern by immunoblot analysis of both normal and WAS-transfected fibroblasts appears identical. These results indicate that WAS-derived cells can express leukosialin and that the product of WAS X-chromosome mutation may not be expressed in fibroblasts. 相似文献
95.
Fukuda Y 《Neuroscience research》2000,38(4):407-417
To clarify a possible origin of 'respiratory like' rhythmic activities observed in in vitro brainstem preparation, the phrenic (Phr) and cranial nerve (XII or IX) inspiratory activities were analyzed in halothane-anesthetized, vagotomized and artificially ventilated newborn (2--6 days after birth) and young adult rats (30--50 days) during altered chemical stimuli and prolonged asphyxia at 25 degrees C. The newborn rat showed regular rhythmic inspiratory discharges of short duration, and their responses to CO(2) and hypoxia did not differ from those seen in adult rats. In the newborn rat the Phr and cranial nerve inspiratory discharges increased first, then respiratory frequency decreased and finally ceased completely for approximately 1--2 min during asphyxia. Thereafter, 'secondary' rhythmic inspiratory activity emerged at a slower rate with decremental inspiratory discharge profile, which persisted for a period more than 40 min of asphyxia. A normal respiratory activity recovered after resumption of artificial ventilation. Though young adult rats exhibited similar sequential changes in respiratory activity during asphyxia, the 'secondary' rhythmic activity persisted for a period of several min only. The pattern of 'secondary' respiratory activity corresponded well with that of rhythmic activities seen in the isolated medullary block preparation of newborn rat. 'Respiratory like' activity found in isolated medullary preparations of newborn animals may arise from a mechanism that generates 'secondary' (or so called 'gasping' type) rhythmic inspiratory activity during prolonged asphyxia in in vivo preparations. 相似文献
96.
97.
98.
Hisao Yamaguchi Junya Fukuda Kensuke Baba Hiroshi Takeuchi Keizo Kageyama 《Pathology international》1972,22(3):427-440
The vascular structures in the lymph node and their relation to fluid exchange have been reported in previous communications and it was considered that the morphological changes of the vascular structures were closely correlated with the functional development of lymph nodes as an antibody forming organ. In order to clarify the localization of the given antigen and newly formed antibody in relation to the morphological structure of lymph nodes, the popliteal lymph nodes of rabbits were studied by immuno-fluorescent techniques.
The antibody was found in the pavement arrangement (solid) of reticulum tissue which was formed by the expel of lymphocytes in the cortical mass and by the morphofunctional alterations of the reticulum cells. The given antigen and newly formed antibody were never detected in the follicles throughout the period of this experiment. ACTA PATH. JAP. 22:427–440, 1972. 相似文献
The antibody was found in the pavement arrangement (solid) of reticulum tissue which was formed by the expel of lymphocytes in the cortical mass and by the morphofunctional alterations of the reticulum cells. The given antigen and newly formed antibody were never detected in the follicles throughout the period of this experiment. ACTA PATH. JAP. 22:427–440, 1972. 相似文献
99.
Multiple epithelial cysts of the spleen and on the splenic capsule, and high serum levels of CA19-9, CA125 and soluble IL-2 receptor 总被引:1,自引:0,他引:1
Hashimoto T Sugino T Fukuda T Hoshi N Ogura G Watanabe K Satoh Y Hasegawa T Ohishi A Haga J Miyata M Suzuki T 《Pathology international》2004,54(5):349-354
An 18-year-old woman with abdominal pain was diagnosed as having splenic cysts by computed tomography scan. She had high serum levels of CA19-9 (2886.8 U/mL; normal value, <35 U/mL), CA125 (131.1 U/mL; normal value, <35 U/mL) and soluble IL-2 receptor (1490 U/mL; normal range, 220-530 U/mL). The resected spleen weighed 1050 g, was 14 x 28 cm, and had more than 10 macroscopic cysts up to 10.3 x 9.5 cm. There were numerous microscopic cysts in the spleen and several on the splenic capsule. The levels of CA19-9 and CA125 in the cyst fluid were 2165550 U/mL and 160400 U/mL, respectively. After the surgery, the serum levels of the tumor markers decreased gradually. The inside of the largest cyst was mainly covered by granulation tissue with a focal lining of epithelial cells, and the other macroscopic cysts had stratified squamous epithelium. The microscopic splenic cysts and cysts on the splenic capsule were lined by either attenuated single-layered or multilayered epithelial cells. The lining epithelial cells of these cysts were positive for epithelial membrane antigen and cytokeratins. CA19-9 and CA125 were detected in the lining cells of the splenic cysts. In the present case, it is suspected that the splenic cysts were derived from the capsular lining cells that showed migration from the capsule or formed microcysts on the splenic capsule, as in the case of ovarian inclusion cysts. 相似文献
100.
Activation of lipid metabolism contributes to interleukin-8 production during Chlamydia trachomatis infection of cervical epithelial cells 下载免费PDF全文
Chlamydia trachomatis infection is the most common cause of bacterial sexually transmitted diseases. Infection of the urogenital tract by C. trachomatis causes chronic inflammation and related clinical complications. Unlike other invasive bacteria that induce a rapid cytokine/chemokine production, chlamydial infection induces delayed inflammatory response and proinflammatory chemokine production that is dependent on bacterial growth. We present data here to show that the lipid metabolism required for chlamydial growth contributes to Chlamydia-induced proinflammatory chemokine production. By gene microarray profiling, validated with biochemical studies, we found that C. trachomatis LGV2 selectively upregulated PTGS2 (COX2) and PTGER4 (EP4) in cervical epithelial HeLa 229 cells. COX2 is an enzyme that catalyzes the rate-limiting step of arachidonic acid conversion to prostaglandins, including prostaglandin E2 (PGE2) and other eicosanoids, whereas EP4 is a subtype of cell surface receptors for PGE2. We show that Chlamydia infection induced COX2 protein expression in both epithelial cells and peripheral blood mononuclear cells and promoted PGE2 release. Exogenous PGE2 was able to induce interleukin-8 release in HeLa 229 epithelial cells. Finally, we demonstrated that interleukin-8 induction by Chlamydia infection or PGE2 treatment was dependent on extracellular signal-regulated kinase/mitogen-activated protein activity. Together, these data demonstrate that the host lipid remodeling process required for chlamydial growth contributes to proinflammatory chemokine production. This study also highlights the importance of maintaining a balanced habitat for parasitic pathogens as obligate intracellular organisms. 相似文献