全文获取类型
收费全文 | 25959篇 |
免费 | 1222篇 |
国内免费 | 218篇 |
专业分类
耳鼻咽喉 | 225篇 |
儿科学 | 623篇 |
妇产科学 | 219篇 |
基础医学 | 3243篇 |
口腔科学 | 407篇 |
临床医学 | 1590篇 |
内科学 | 7253篇 |
皮肤病学 | 396篇 |
神经病学 | 1762篇 |
特种医学 | 1024篇 |
外科学 | 4555篇 |
综合类 | 101篇 |
预防医学 | 655篇 |
眼科学 | 332篇 |
药学 | 1555篇 |
中国医学 | 41篇 |
肿瘤学 | 3418篇 |
出版年
2023年 | 194篇 |
2022年 | 374篇 |
2021年 | 667篇 |
2020年 | 345篇 |
2019年 | 503篇 |
2018年 | 628篇 |
2017年 | 493篇 |
2016年 | 654篇 |
2015年 | 658篇 |
2014年 | 894篇 |
2013年 | 1017篇 |
2012年 | 1647篇 |
2011年 | 1843篇 |
2010年 | 1024篇 |
2009年 | 862篇 |
2008年 | 1516篇 |
2007年 | 1697篇 |
2006年 | 1709篇 |
2005年 | 1705篇 |
2004年 | 1640篇 |
2003年 | 1571篇 |
2002年 | 1494篇 |
2001年 | 348篇 |
2000年 | 264篇 |
1999年 | 314篇 |
1998年 | 369篇 |
1997年 | 293篇 |
1996年 | 275篇 |
1995年 | 217篇 |
1994年 | 198篇 |
1993年 | 183篇 |
1992年 | 185篇 |
1991年 | 176篇 |
1990年 | 155篇 |
1989年 | 138篇 |
1988年 | 137篇 |
1987年 | 105篇 |
1986年 | 107篇 |
1985年 | 115篇 |
1984年 | 85篇 |
1983年 | 64篇 |
1982年 | 54篇 |
1981年 | 47篇 |
1980年 | 34篇 |
1979年 | 33篇 |
1978年 | 34篇 |
1977年 | 36篇 |
1975年 | 29篇 |
1973年 | 27篇 |
1968年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
Shohachi Suzuki Satoshi Nakamura Hideki Ishida Takanori Sakaguchi Atsushi Serizawa Hiroyuki Konno Shozo Baba Hiroyuki Muro Isao Kosugi Eisaku Gu 《Surgery today》1996,26(8):635-639
Hepatic angiomyolipoma is a rare tumor composed of spindle-shaped and epithelioid smooth muscle cells, adipose tissue, and proliferating blood vessels. We report the first documented case of this tumor developing in a patient with ulcerative colitis. A solitary tumor (7.5×7.5×7cm) was detected in the left lateral segment of the liver and a left hepatic lobectomy was performed. The diagnosis of angiomyolipoma was confirmed by a pathological examination. We also review the literature on previously reported cases of hepatic angiomyolipoma. 相似文献
93.
Eimoto Hiroyuki; Tsutsumi Masahiro; Nakajima Akira; Yamamoto Kazuhiko; Takashima Yokashima; Maruyama Hiroshi; Konishi Yoichi 《Carcinogenesis》1988,9(12):2325-2327
Expression of glutathione S-transferase placental form (GST-)in human lung carcinoma tissue taken at autopsy or biopsy wasinvestigated immunohistochemically. All of 34 cases of squamouscell carcinomas, including poorly, moderatelyand well-differentiatedexamples were shown to stain positively for GST-. Poorly differentiatedadenocarcinomas were, however, negatively stained (0/5 cases),while moderately and well differentiated adenocarcinomas werefound tostain with GST- at rates of 69% (9/13 cases) and 71%(5/7 cases), respectively. Six cases of small cell carcinomasexamined were all negative. The results indicate that GST- maybe a useful marker fornon-small cell type lung cancer, especiallysquamous cell carcinoma which is in agreement with findingsfor rat lung neoplastic lesions reported previously. 相似文献
94.
Possible involvement of arachidonic acid metabolism in phenobarbital promotion of hepatocarcinogenesis 总被引:8,自引:4,他引:4
Denda Ayumi; Ura Hitoshi; Tsujiuchi Toshifumi; Masahiro Tsutsumi; Eimoto Hiroyuki; Takashima Yoshiharu; Kitazawa Shunji; Kinugasa Tetsuo; Konishi Yoich 《Carcinogenesis》1989,10(10):1929-1935
The effects of inhibitors of arachidonic acid metabolism andantioxidants on the rat liver tumor promotion activity of phenobarbital(PB) were assessed using the enzyme-altered focus as the end-pointlesion. Fischer 344 male rats were initiated with N-nitrosodiethylamine(200 mg/kg) and then divided into five groups placed on basaldiet, diet containing 0.05% PB, diet containing 0.05% PB plus0.75%, 1% or 1.5% levels of various inhibitors of arachidonicacid metabolism or antioxidants, or diet containing 1% or 1.5%inhibitors or antioxidants alone for 10 weeks, and then killed.-Bromo phenacyl bromide, an inhibitor of phospholipase A2 significantly inhibited the promotion activity of PB at dose levelsof 0.75% and 1.5%, reaching plateau at 0.75%. Both quercetin,an inhibitor of lipoxygenase, and morin, a dual inhibitor oflipoxygenase-cyclooxygenase, significantly reduced the promotionactivity of PB at the 1.5% but not 0.75% dose levels. Moreover,acetylsalicylic acid, an inhibitor of cyclooxygenase dose-dependentlyinhibited the promotion activity of PB. Among the antioxidantsinvestigated, vitamin E did not affect, but n-propyl gallateand ethoxyquin exerted a dose-dependent inhibition of PB promotion.These results are strongly suggestive of an involvement of phospholipaseA2 lipoxygenase and cyclooxygenase arachidonic acid metabolicpathways in the mechanisms underlying PB enhancement of hepatocarcinogenesis. 相似文献
95.
Hiroyuki Ito Reiko Takikawa Yoshihisa Kurachi Tsuneaki Sugimoto 《Naunyn-Schmiedeberg's archives of pharmacology》1989,339(1-2):244-246
Summary Effects of verapamil on the acetylcholine (ACh)-induced K+ current were examined in single atrial cells, using the tight-seal whole-cell clamp technique. The pipette solution contained guanosine-5-triphosphate (GTP) or guanosine-5-O-(3-thiotriphosphate) (GTP-S, a non-hydrolysable GTP analogue). In GTP-loaded cells, ACh induced a specific K+ current, which is known to be mediated by pertussis toxin-sensitive GTP-binding (G) proteins. Verapamil (0.1–100 M) depressed the ACh-induced K+ current in a concentration-dependent fashion. In GTP-S-loaded cells, the K+ current remained persistently after wash-out of ACh, probably due to irreversible activation of G proteins by GTP-S. Verapamil (0.1–100 M) also depressed the intracellular GTP-S-induced K+ current. However, the magnitude of verapamil-depression of the K+ current in GTP-S-loaded cells was significantly smaller than that in GTP-loaded cells at concentrations between 1 and 10 M of the drug. From these results, it is suggested that verapamil may block not only the function of muscarinic ACh receptors but also of G proteins and/or the K+ channel itself and thereby depress the ACh-induced K+ current in isolated atrial myocytes.Supported by grants from the Ministry of Education, Science and Culture of Japan and the Research Program on Ca Signal Control
Send offprint requests to Y. Kurachi at the above address 相似文献
96.
Kangouri K Miyoshi T Kawashima A Ikeda A Mizutani T Omura S Lian-Niang L Hong X 《Planta medica》1989,55(3):297-299
Neokadsuranic acid A, which is the first triterpenoid with the 14(13-->12) ABEO lanostane skeleton, was isolated from KADSURA HETEROCLITA together with (24 Z)-3-oxo-lanosta-8,24-dien-26-oic acid. The present paper deals with the isolation and structure elucidation of these two new compounds. 相似文献
97.
98.
Transient receptor potential (TRP) channels provide an enormous variability of Ca(2+) influx mechanisms triggered by a wide range of stimuli. In this review, we discuss the activation properties of the Ca(2+)- and Mg(2+)-permeable TRP channel of the vanilloid subfamily TRPV4. This channel is activated by various physical and chemical stimuli, such as cell swelling, heat, phorbols and, probably, by endogenous ligands, which are able to induce Ca(2+) entry. Not much is known about the regulation of this channel. We will refer only to a mechanism of Ca(2+)-dependent inhibition of TRPV4. Possible functional roles of this channel will be correlated with its observed expression pattern. Finally, we discuss the structural determinants of TRPV4 channel function. 相似文献
99.
Epstein-Barr virus (EBV) is an important pathogen in human immunodeficiency virus (HIV)-infected individuals that causes lymphoma and other lymphoproliferative disorders upon disease progression; however, interaction between the two viruses during acute infection is not well known. Expression of CCR5, a major coreceptor for HIV, was enhanced on CD4+ T cells from patients with acute EBV infection. Furthermore, susceptibility of those cells to R5-HIV-1, but not X4-HIV-1, was increased. EBV effects on CCR5 expression on or susceptibility to R5-HIV-1 of CD4+ T cells did not require coinfection of the same cell with the two viruses, because CD4+ T cells from patients with acute EBV infection were not infected with EBV. Considering that both HIV and EBV are transmitted by intimate contact, such possible interaction between the two viruses may have implications for viral transmission and the pathogenesis of HIV disease. 相似文献
100.
Availability of CD10 immunohistochemistry as a marker of breast myoepithelial cells on paraffin sections. 总被引:12,自引:0,他引:12
Suzuko Moritani Ryoji Kushima Hiroyuki Sugihara Masamichi Bamba Tadao K Kobayashi Takanori Hattori 《Modern pathology》2002,15(4):397-405
CD10, also called common acute lymphoblastic leukemia antigen (CALLA), was recently found to be expressed in nonhematopoietic tissues. Although CD10 was also identified in human breast myoepithelial cells, its availability of immunohistochemistry on paraffin sections has not been examined so far. In the present study, we demonstrated CD10 immunohistochemically on paraffin sections of both normal and pathological breast tissues, comparing its staining patterns to those of smooth muscle actin (SMA), which is now commonly used to highlight myoepithelium. CD10 was consistently positive in normal breast myoepithelial cells. CD10 also clearly highlighted myoepithelial cells in intraductal papilloma, adenosis, ductal hyperplasia, fibroadenoma, and phyllodes tumor as well as SMA did. In atypical ductal hyperplasia and ductal carcinoma in situ, continuous, discontinuous, and totally negative stainings of both CD10 and SMA were noted, depending on foci of neoplastic cell nests. However, both stainings clearly demonstrated myoepithelial cells of cancerized acini, being useful in differentiating lobular cancerization from microinvasion. Because SMA was also positive in normal vessels and spindle-shaped stromal cells, CD10, which was negative in vessels, was useful in differentiating myoepithelial cells from thin vascular wall in intracystic lesions with delicate papillae. Although background staining of spindle-shaped stromal cells was also noted in CD10, the positive cell number was less, and the signal was weaker than that of SMA. The absence of myoepithelial cells in invasive ductal carcinomas was more clearly highlighted by CD10 than SMA. We concluded that CD10 could be another useful marker of breast myoepithelial cells on paraffin sections. Combination of CD10 and SMA will provide more sophisticated information about presence or absence of myoepithelial cells in confusing breast lesions. 相似文献