全文获取类型
收费全文 | 13362篇 |
免费 | 562篇 |
国内免费 | 91篇 |
专业分类
耳鼻咽喉 | 202篇 |
儿科学 | 377篇 |
妇产科学 | 153篇 |
基础医学 | 2056篇 |
口腔科学 | 305篇 |
临床医学 | 690篇 |
内科学 | 3011篇 |
皮肤病学 | 225篇 |
神经病学 | 1192篇 |
特种医学 | 560篇 |
外科学 | 2435篇 |
综合类 | 41篇 |
预防医学 | 335篇 |
眼科学 | 172篇 |
药学 | 769篇 |
中国医学 | 39篇 |
肿瘤学 | 1453篇 |
出版年
2023年 | 67篇 |
2022年 | 144篇 |
2021年 | 300篇 |
2020年 | 142篇 |
2019年 | 200篇 |
2018年 | 254篇 |
2017年 | 206篇 |
2016年 | 235篇 |
2015年 | 264篇 |
2014年 | 364篇 |
2013年 | 443篇 |
2012年 | 685篇 |
2011年 | 790篇 |
2010年 | 453篇 |
2009年 | 351篇 |
2008年 | 608篇 |
2007年 | 712篇 |
2006年 | 722篇 |
2005年 | 745篇 |
2004年 | 808篇 |
2003年 | 738篇 |
2002年 | 838篇 |
2001年 | 340篇 |
2000年 | 293篇 |
1999年 | 296篇 |
1998年 | 214篇 |
1997年 | 188篇 |
1996年 | 183篇 |
1995年 | 132篇 |
1994年 | 153篇 |
1993年 | 131篇 |
1992年 | 210篇 |
1991年 | 184篇 |
1990年 | 179篇 |
1989年 | 162篇 |
1988年 | 139篇 |
1987年 | 109篇 |
1986年 | 110篇 |
1985年 | 109篇 |
1984年 | 92篇 |
1983年 | 73篇 |
1982年 | 52篇 |
1981年 | 45篇 |
1980年 | 50篇 |
1979年 | 62篇 |
1978年 | 42篇 |
1977年 | 43篇 |
1976年 | 34篇 |
1974年 | 47篇 |
1973年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Shiro Akinaga Tadashi Ashizawa Katsushige Gomi Hiroe Ohno Makoto Morimoto Chikara Murakata Masami Okabe 《Cancer chemotherapy and pharmacology》1992,29(4):266-272
Summary Novel derivatives of K-252a, (8R*,9S*,11S*)-(–)-9-hydroxy-9-methoxycarbonyl-8-methyl-2,3,9,10-tetrahydro-8, 11-epoxy-1H,8H,11H-2,7b,11a-triazadibenzo [a,g]-cycloocta[cde]trinden-1-one, an inhibitor of protein kinases and calmodulin-dependent phosphodiesterase, were synthesized and evaluated for their antitumor activity in vitro and in vivo. Of ten derivatives tested, four were active against the P388 murine leukemia i. p.-i. p. system, although K-252a was inactive. Among these derivatives, KT6124 was selected for further biological evaluation studies because its efficacy was the highest. KT6124 was also active against sarcoma 180 and B16 melanoma. It exerted a relatively broad spectrum of antiproliferative activity against 20 human tumor cell lines in vitro. To determine the mechanism(s) of action underlying the antitumor activity of KT6124, we tested the drug for inhibition of protein kinases, including Ca2+-and phospholipid-dependent protein kinase (PKC), in intact A431 human epidermoid carcinoma cells in comparison with the PKC-inhibitory activity of K-252a. KT6124 did not antagonize the action of phorbol 12-myristate 13-acetate (PMA) in A431 cells, whereas K-252a did, suggesting that KT6124 may not act on protein kinases in the cells. The interaction of KT6124 with DNA in living cells was examined by the alkaline elution method. KT6124 apparantly exhibited DNA scission both dose-and time-dependently in the target cells. The DNA breakage was dependent on proteinase K treatment, suggesting its possible interaction with DNA-related enzyme(s). These results indicate that KT6124 exerts antitumor activity by acting on DNA or on DNA-related enzyme(s) in tumor cells rather than via the inhibition of protein kinases. 相似文献
2.
Y Miyasaka M Sakurai A T Yokobori S Kuroda M Ohyama 《Bio-medical materials and engineering》1991,1(1):3-10
Long bone injuries in clinical cases are studied by comparison of roentgenograms with a rational mechanical analysis of the injuries. Fractures produced by torsional loads have a spiral shape with a smooth and even surface. Fractures induced by bending loads have uneven and rugged fracture surfaces perpendicular to the bone axis. Long bones are weak in torsion but strong in tensile stress produced by bending. This result corresponds to the clinical fact that a large direct external force is needed to produce a transverse fracture while a spiral fracture is produced by a relatively small torque. 相似文献
3.
Tadashi Kato 《Seishin shinkeigaku zasshi》2002,104(6):509-512
4.
Yutaka Okishio Tadayoshi Takeuchi Akikazu Fujita Kiyotaka Suenaga Kaori Fujinami Satoru Munakata Tadashi Takewaki Fumiaki Hata 《Journal of Smooth Muscle Research》2005,41(3):163-174
Recently an essential role of interstitial cells of Cajal (ICC) within myenteric plexus (ICC-MY) was suggested in ascending contraction and descending relaxation in the mouse ileum. The role of ICC in these neural reflexes was examined in the distal colonic segments prepared from the wild type and c-kit mutant, W/W(V) mice, in the present study. Localized distension of the segments from the wild type mice by using a small balloon resulted in ascending contraction and descending relaxation. In the segments from the mutant mice, localized distension also induced these neural reflexes similar to those observed in the wild type mice. Immunohistochemical examination demonstrated that ICC-MY and ICC present in muscle layers (ICC-IM) were severely disrupted in the mutant mouse, but only ICC, present within submucosal plexus (ICC-SMP), remained unchanged. In the small strips with ICC-SMP absent prepared from the mutant mouse, electrical field stimulation induced contraction or relaxation in the absence or presence of atropine, respectively. It was suggested that ICC have no important role in the ascending and descending neural reflexes in the mouse distal colon, this is in direct contrast to the role of ICC-MY in the ileum. 相似文献
5.
Roberto Civitelli M.D. Eturo Ogata Louis V. Avioli Gary Stein Samuel Edelstein John A. Eisman Yasuho Nishii Hajime Orimo Jane Lian Takuo Fujita Yasufumi Hayashi Shigeaki Kato Tadashi Kobayashi Hirotoshi Morii Rikushi Morita Toshitaka Nakamura Yoshiki Seino Masataka Shiraki Tatsuo Suda Naoyuki Takahashi Hideaki Takahashi Tastuhiko Tanisawa Akifumi Tokita 《Calcified tissue international》1995,57(6):409-414
6.
A. Robert Spitzer Shalom Stahl David Yarnitsky Ernest W. Johnson John R. Wilson R. A. C. Hughes Stefania Morino Giovanni Antonini Kiyotoshi Kaneko Yoji Ohnishi Tetsushi Atsumi Isao Hozumi Tadashi Miyatake Tetsuo Furukawa James P. Knochel Ikuo Mineo Seiichiro Tarui Francis O. Walker Andrew J. Gitter Walter C. Stolov Nicholas J. Capozzoli 《Muscle & nerve》1996,19(4):531-538
7.
Diagnosis and treatment of thoracic outlet syndrome 总被引:2,自引:0,他引:2
Masataka Abe Tadashi Shimamura Jun Nishida Katsuaki Ichinohe 《Journal of orthopaedic science》1997,2(2):119-127
Patients who develop symptoms of thoracic outlet syndrome (TOS) have a predisposing anatomic abnormality. In most patients
with TOS, the symptoms are caused by entrapment of the brachial plexus and they do not arise from compression of the subclavian
artery, as was previously thought. The tests advocated for diagnosing this common syndrome (i.e., evaluating the positional
compression of the artery when the arms are raised, the neck is turned, or the shoulders are braced) cannot accurately diagnose
this syndrome. There are two reasons for this. The symptoms of TOS are not related to the compression of the artery in the
outlet in 98% of patients, and 75% of normal individuals without symptoms show diminished radial pulse on various provocation
tests. We employed four timed provocation tests (minute tests) to diagnose TOS: the timed Morley test, timed Wright test,
timed Eden test, and elevated arm stress exercise, all of which are very sensitive. In normal individuals without symptoms,
20% experience transitional symptoms such as slight pain and tiredness, on these tests indicating a subclinical state. TOS
is treated by keeping the thoracic outlet wide, this being done either conservatively or surgically. In 1993 and 1994, we
conservatively treated 418 of 422 patients with TOS by means of active exercise, a brace, and by block therapy. These measures
did not reduce the symptoms in 23 of these patients, so surgical treatment was indicated. In the remaining 4 of the 422 patients,
conservative treatment was not indicated and surgery was performed directly. All the patients showed significant clinical
improvement of varying degree.
Presented at the 69th Annual Meeting of the Japanese Orthopaedic Association, Tokyo, April 12, 1996 相似文献
8.
Hideki SATO Kazuyuki KANEMASA Masamichi TANINO Tsugihiro KIMURA Kenji MAENOU Shouji MITSUFUJI Kyouhei MARUYAMA Tadashi KODAMA Kei KASHIMA Naoki TERAMAE Susumu FUKUI Keizo KAGAWA 《Digestive endoscopy》1996,8(1):41-45
Abstract: Biliobiliary fistula is a rare clinical entity. The case of a 72 year old female, who presented with epigastric pain and jaundice, is detailed herein. Endoscopic retrograde cholangiopancreatography (ERCP) revealed two stones, one each in the common bile duct and the gallbladder. Continuous endoscopic nasobiliary drainage (ENBD) was performed to relieve obstructive jaundice. Further study with contrast medium administered via the ENBD tube revealed a fistula between the neck of the gallbladder and the common bile duct. The cystic duct was intact. A stone was considered to have migrated into the common bile duct through the fistula. A diagnosis of biliobiliary fistula, Corlette type I was made. However, in this particular case, a biliobiliary fistula was noted at a site below the junction of the cystic duct and common bile duct. Removal of the gallbladder stones was followed by cholecystectomy. The common bile duct was then repaired by utilizing a T-tube. No evidence of malignancy was recognized in the resected gallbladder specimen. In the one year to date since surgery, the patient has been asymptomatic and without signs of biliary disease. 相似文献
9.
Naoharu Iwai Tadashi Inagami Masahiko Kinoshita 《Clinical and experimental pharmacology & physiology》1994,21(11):913-914
1. We have recently identified a candidate gene for rat genetic hypertension, termed Sa, by identifying an mRN A species that shows markedly higher expression in the kidneys of spontaneously hypertensive rats (SHR) than in those of Wistar-Kyoto rats (WKY). 2. Subsequent genetic co-segregation analyses by ourselves and others indicated that the Sa gene locus did indeed influence blood pressure. Moreover, in a preliminary association study, we found an association of a polymorphism of the human Sa gene with essential hypertension. 3. Further studies to identify functions of the Sa gene products are required before reaching a definite conclusion. 相似文献
10.
Hiroshi Ujike Kazuo Tsuchida Kazufumi Akiyama Yutaka Fujiwara Shigetoshi Kuroda 《Pharmacology, biochemistry, and behavior》1995,50(4):613-617
The ontogeny of the behavioral effects of acute cocaine administration and behavioral sensitization to cocaine in rat pups was investigated. Acute behavior stimulating effects of cocaine were observed in pups as young as 7 postnatal days (PND) old, although they needed a higher dose of cocaine than adult rats to evoke the same motor effects. An adult dose-response curve pattern of stereotypy and locomotion to acute cocaine treatment was observed at PND 21, and of rearing at PND 28. Rats aged PND 7, 14, 21, 28, and 56 received repeated injections of saline or cocaine (15 mg/kg) twice a day for 5 consecutive days. After a 3-week period of abstinence, sensitization to a challenge dose of cocaine was assessed. Cocaine-induced stereotyped behavior was enhanced significantly only in rats in which cocaine pretreatment was initiated on PND 21, 28, and 56, but not earlier on PND 7 and 14. Adult female rats given repeated cocaine injections on PND 56–60 showed significantly greater sensitization than males, but no such sex difference was observed in pups given cocaine repeatedly on PND 21–25 or 28–32. These results show clearly that cocaine-induced behavioral sensitization in rats occurred only when subchronic cocaine administration was commenced on PND 21 or later. 相似文献