全文获取类型
收费全文 | 11930篇 |
免费 | 415篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 129篇 |
儿科学 | 224篇 |
妇产科学 | 77篇 |
基础医学 | 1487篇 |
口腔科学 | 280篇 |
临床医学 | 593篇 |
内科学 | 2873篇 |
皮肤病学 | 101篇 |
神经病学 | 1059篇 |
特种医学 | 463篇 |
外科学 | 2020篇 |
综合类 | 85篇 |
预防医学 | 348篇 |
眼科学 | 439篇 |
药学 | 918篇 |
中国医学 | 72篇 |
肿瘤学 | 1245篇 |
出版年
2023年 | 34篇 |
2022年 | 74篇 |
2021年 | 145篇 |
2020年 | 89篇 |
2019年 | 105篇 |
2018年 | 144篇 |
2017年 | 114篇 |
2016年 | 176篇 |
2015年 | 185篇 |
2014年 | 245篇 |
2013年 | 375篇 |
2012年 | 641篇 |
2011年 | 711篇 |
2010年 | 377篇 |
2009年 | 329篇 |
2008年 | 687篇 |
2007年 | 822篇 |
2006年 | 843篇 |
2005年 | 883篇 |
2004年 | 917篇 |
2003年 | 872篇 |
2002年 | 909篇 |
2001年 | 165篇 |
2000年 | 123篇 |
1999年 | 172篇 |
1998年 | 242篇 |
1997年 | 211篇 |
1996年 | 182篇 |
1995年 | 160篇 |
1994年 | 168篇 |
1993年 | 141篇 |
1992年 | 111篇 |
1991年 | 107篇 |
1990年 | 97篇 |
1989年 | 72篇 |
1988年 | 68篇 |
1987年 | 62篇 |
1986年 | 55篇 |
1985年 | 54篇 |
1984年 | 64篇 |
1983年 | 49篇 |
1982年 | 60篇 |
1981年 | 55篇 |
1980年 | 63篇 |
1979年 | 33篇 |
1978年 | 38篇 |
1977年 | 30篇 |
1975年 | 22篇 |
1974年 | 18篇 |
1973年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Tadaki Yasumura MD Toshikazu Akami Manabu Mitsuo Takahiro Oka Kazuo Naitoh Takara Yamamoto Hideo Honjyo Hiroji Okada 《Surgery today》1990,20(4):369-375
The ovarian and pituitary functions of 64 operable breast cancer patients undergoing adjuvant therapy with cytotoxic chemotherapy
and/or tamoxifen were investigated. The post menopausal patients, divided into 3 treatment groups, one with tamoxifen alone,
one with tamoxifen and chemotherapy and the other with chemotherapy alone had serum estradiol 17-β (E2) and progesterone levels
lower than the evaluable limits. Although there was no significant difference in the level of estrone sulfate (E1-S) between
these three groups, the level of lutainizing hormone (LH) and follicle stimulating hormone (FSH) in the patients treated with
tamoxifen alone and tamoxifen and chemotherapy were significantly lower than those treated with chemotherapy alone. The decrease
in gonadotropin levels induced by tamoxifen treatment was reversible as it appeared after the initiation of tamoxifen and
recovered after its cessation. In the premenopausal patients, a group treated with tamoxifen and chemotherapy had significantly
higher E1-S, E2 and progesterone levels and significantly lower gonadotropin levels than a group treated with chemotherapy
alone or one treated with a cyclophosphamide regimen. These increases in the levels of estrogen and progesterone were also
reversible, and induced by tamoxifen. Thus, adjuvant endocrinochemotherapy causes profound alteration in the hypothalamo-pituitary-ovarian
axis and therefore, monitoring a variety of hormonal levels is thought to be necessary for assessing the consequences of adjuvant
therapy in breast cancer patients, especially in premenopausal patients using tamoxifen. 相似文献
52.
Hiroko Sasahara Susumu Sueyoshi Toshiaki Tanaka Hiromasa Fujita Kazuo Shirouzu 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(5):231-239
Objective: The purpose of this experimental study was to investigate whether aortic stent grafting can be applied to the treatment of
an esophageal cancer involving the thoracic aorta. Methods: The canine thoracic aorta was partially resected without aorta being clamped after emplacement of an endovascular stent graft.
Study I; The aortic whole layer of 1 cm in length and 1/4 of the circumference was resected and was covered by a free fascia
patch of the abdominal rectal muscle immediately after stent graft placement. Study II; The aortic adventitia and the outer
half of the media of the same size was resected on day 3, 7,14, 21, and on day 28, after the stent graft placement. The resected
portion was covered by the free fascia patch in half experimental dogs, and was uncovered in the others. Study III; The aortic
adventitia and the outer half of the media of 1 cm in length and 1/2 of the circumference was resected and was uncovered on
day 7 after stent graft placement. Histological examinations were performed on day 28 and at one year after aortic resection.
Results: The aortic wall could be resected in all cases with no complication, except in resection of 1/2 the circumference where the
aorta had become narrow. There was no difference in healing of the resected portion of the aorta between with and without
fascia covering. Conclusion: An aortic endovascular stent graft could be applied to surgery for an esophageal cancer involving the aorta. 相似文献
53.
Norio Ohkoshi Hldehlro Mizusawa Nobuko Shiraiwa Shin'Ichi Shoji Katsutoshi Harada Kazuo Yoshizawa 《Muscle & nerve》1995,18(11):1265-1271
Lmmunohistochemical analyses were made of the superoxide dismutases (Mn-SOD and CuiZn-SOD) in biopsied muscles from 7 patients with mitochondrial encephalomyopathies that included mitochondrial encephalomyopathy, lactic acidosis and strokelike episodes (MELAS), and chronic progressive external ophthalmoplegia (CPEO). Mn-SOD mainly was present in the subsarcolemmal region, but it also was found in a coarsely granular, reticular, or diffuse pattern of staining within the muscle fibers. These Mn-SOD-positive fibers corresponded almost completely to the ragged-red fibers. The immunoreaction for CuiZn-SOD was weakly positive in some of the muscle fibers positive for Mn-SOD. In CPEO, Mn-SOD-positive fibers predominantly showed decreased cytochrome c oxidase (COX) activity. In MELAS, Mn-SOD-positive fibers tended to be stained deeply for COX although a few were COX-negative. These findings suggest that Mn-SOD-positive fibers can be used to make a differential diagnosis between CPEO and MELAS and that in mitochondrial encephalomyopathies Mn-SOD in the raggedred fibers may protect against oxidative stress. © John Wiley & Sons, Inc. 相似文献
54.
Toshifumi Gabata Masumi Kadoya Osamu Matsui Masashi Yamashiro Tsutomu Takashima Donald G. Mitchell Yasutaka Nakamura Kazuo Takeuchi Yasuni Nakanuma 《Journal of magnetic resonance imaging : JMRI》1998,8(2):503-504
We reported a case of the biliary cystadenoma of the liver. The cystic mass had labulation and septation and showed marked hyperintensity on T1-weighted images and hypointensity on T2-weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly-like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid. 相似文献
55.
Kazuo Noguchi Kenzo Takahashi Shohei Higuchi 《The Journal of pharmacy and pharmacology》1998,50(3):329-334
The effects of CD-832 (4R-(-)-2-(nicotinoylamino)ethyl-3-nitroxypropyl-1,4-dihydro-2,6-dimethyl-4,3-nitrophenyl, 3,5-pyridine dicarboxylate), a novel dihydropyridine derivative, on guinea-pig isolated myocardial preparations have been compared with those of Ca2+-channel antagonists. All ten compounds induced concentration-dependent negative chronotropic effects on preparations of isolated right atria and negative inotropic effects on isolated right ventricular papillary muscles. The order of potency for the negative chronotropic effect was CD-832 > nicardipine = gallopamil > clentiazem > nifedipine = efonidipine > amlodipine = semotiadil > verapamil > diltiazem; that for the negative inotropic effect was nicardipine = gallopamil > nifedipine > verapamil > CD-832 > diltiazem > clentiazem > efonidipine = semotiadil > amlodipine. The ratio of the EC50 (the concentration of Ca2+ antagonist having 50% of the maximum effect) for the negative inotropic effect divided by the EC50 for the negative chronotropic effect, considered to be an index of selectivity for negative chronotropic effect, was higher for CD-832, amlodipine, efonidipine and semotiadil than for the other Ca2+ antagonists. The ratio for CD-832, nifedipine, nicardipine, efonidipine, amlodipine, verapamil, gallopamil, diltiazem, clentiazem and semotiadil was 11·4, 0·29, 0·87, 35·4, 37·1, 0·65, 0·87, 0·92, 7·11 and 30·0, respectively. These findings indicate that CD-832 and the newly developed Ca2+ antagonists including amlodipine, efonidipine, semotiadil and clentiazem were selective for a negative chronotropic effect rather than for a negative inotropic effect. This ‘chrono-selective’ effect of these drugs might be of benefit in the treatment of cardiovascular disorders. 相似文献
56.
Spondylolysis after posterior decompression of the lumbar spine: 35 patients followed for 3-9 years 总被引:5,自引:0,他引:5
Radiographs were examined in 35 patients who had had posterior decompression without fusion of the lumbar spine. Spondylolysis was found in 10 patients. Segmental range of motion, degree of vertebral slippage and width of decompression were analyzed by radiography. There was greater vertebral slippage after surgery in patients with postoperative spondylolysis than in those without spondylolysis. We conclude that excessive bony decompression may cause postoperative spondylolysis. 相似文献
57.
Kazuo Kawasaki Junji Ohnogi 《Documenta ophthalmologica. Advances in ophthalmology》1988,70(4):301-308
The effects of penicillin G (PC-G) sodium, procaine PC-G, cloxacillin sodium (MCIPC), disodium sulbenicillin (SBPC), cefazolin sodium (CEZ), gentamicin sulfate (GM) and fosfomycin sodium (FOM) on the electroretinogram (ERG) of the human in-vitro eye-cup were studied. The oscillatory potentials (OPs) were selectively and greatly suppressed by 1.0mM PC-G sodium. The OPs and c-wave were suppressed by 0.85mM procaine PC-G. The b-wave and OPs were slightly suppressed by 1.0mM MCIPC. The a-wave, b-wave, OPs and c-wave were not deteriorated by 1.0mM SBPC. The OPs appeared to be selectively suppressed by 1.0mM CEZ. The b-wave was suppressed and the peak latencies of the OPs were delayed by 184g/ml (approximately 0.4mM) GM. The amplitudes of the a-wave and c-wave were slightly enhanced and their peak latencies were slightly delayed by 184g/ml GM. The a-wave, b-wave, OPs and c-wave were not deteriorated by 1.0mM FOM. The results of the present study on the human retina were comparable to those on the albino rabbit retina in our previous studies. 相似文献
58.
Suzuki Hisamitsu; Ota Kazuo; Ohno Ryuzo; Masaoka Toru; Shibata Hirotoshi; Kimura Ikuro; Amaki Ichita; Miura Yasusada; Uzuka Yoshiro; Kawato Masafumi; Shirakawa Shigeru; Hirota Yutaka; Maekawa Tadashi; lmai Kuniyuki; Takaku Fumimaro; Shimoyama Masanori; Kitahara Takeshi; Oguro Masao; Kozuru Mitsuo; Kawagoe Hiroya; Nakamura Toru; Yamada Kazumasa 《Japanese journal of clinical oncology》1989,19(4):338-347
Patients with acute (2,569) and chronic (957) leukemia diagnosedat 19 institutes took part in the study on the "MultidisciplinaryTreatment of Leukemia" between 1971 and 1985 and were investigatedretrospectively. By dividing the 15 years into three five-yearperiods, we were able to compare patient ratios in the differentperiods. The proportions of acute to chronic leukemia casesshowed no obvious change; however, the proportions of casesdiagnosed as acute lymphocytic leukemia in acute leukemia showeda significant increase. The main chemotherapeutic drugs usedduring the three time periods were cytarabine or its analogues,the anthracyclines, 6-mercaputopurine and prednisolone, againstacute myelogenous leukemia, and the vinca alkaloids, prednisoloneand the anthracyclines against acute lymphocytic leukemia. Therate of complete remission from acute myelogenous leukemia mademarked progress, from 45.1% during 19711975 to 62.3%during 19811985, but that of acute lymphocytic leukemiashowed no significant progress, being 65% during 19711975and 69.7% during 19811985. The durations of remission,however, and the survival times for patients with acute lymphocyticleukemia, as well as for those with acute myelogenous leukemia,became significantly longer over the three periods. Median survivaltimes from chronic myelocytic leukemia were 3740 mo inall three periods, showing no progress. There was a better prognosisin cases of chronic myelocytic leukemia with, than without,Philadelphia chromosome. Except for a low incidence of chroniclymphocytic leukemia in Japan, adult leukemia patients' characteristicsand prognoses seem to be almost the same in Japan as in theU.S.A. and Europe. 相似文献
59.
Murdiastuti K Miki O Yao C Parvin MN Kosugi-Tanaka C Akamatsu T Kanamori N Hosoi K 《Pflügers Archiv : European journal of physiology》2002,445(3):405-412
By Western blot analysis, the expression level of aquaporin (AQP) 5 in the submandibular gland (SMG) was found to be different among individual rats of the Sprague-Dawley (SD) strain. Such differences were observed for AQP5 but not for AQP1 and consequently the SD strain was divided into two groups, one expressing a high level of AQP5 and the other a low one. The difference in average intensity of expression between the two groups was more than twofold. Immunohistochemical analysis of the SMG demonstrated that the AQP5 protein was localized in the basal and apical/lateral plasma membrane of acinar cells in rats expressing the high level of AQP5. In the rat expressing the low level, however, this channel protein was localized strongly in the apical/lateral plasma membrane, but only very weakly in the basal membrane of the acinar cells. Such a diverse localization of AQP5 was confirmed by Western blotting as well. Breeding between brother and sister was repeated for two times within high expressers and low expressers to obtain the third generation progenies (F2); the AQP5 level of the SMG in the third generation (F2 rats) from high expressers was significantly higher than the F2 from low expressers. Our present study suggests the existence of genetic variation in the expression of a water channel protein, AQP5, in rats. 相似文献
60.
Nakanishi M Yabe S Tanaka N Ito Y Nakamura KT Kitade Y 《Molecular and biochemical parasitology》2005,143(2):146-151
S-adenosylhomocysteine hydrolase is a prospective target for developing new anti-malarial drugs. Inhibition of the hydrolase results in an anti-cellular effect due to the suppression of adenosylmethionine-dependent transmethylations. Based on the crystal structure of Plasmodium falciparum S-adenosylhomocysteine hydrolase which we have determined recently, we performed mutational analyses on P. falciparum and human enzymes. Cys59 and Ala84 of the parasite enzyme, and the equivalent residues on the human enzyme, Thr60 and Gln85, were examined. Mutations of Cys59 and Thr60 caused dramatic impact on inhibition by 2-fluoronoraristeromycin without significant effect both on its kinetic parameters and on inhibition constant against noraristeromycin. In addition, the impact was independent from the electronegativity of the side chain of the substituting residue. These results showed that steric hindrance between a functional group at the 2-position of an adenine nucleoside inhibitor and Thr60 of the human enzyme, not an electrostatic effect, contributed to inhibitor selectivity. 相似文献