全文获取类型
收费全文 | 32455篇 |
免费 | 1747篇 |
国内免费 | 158篇 |
专业分类
耳鼻咽喉 | 296篇 |
儿科学 | 454篇 |
妇产科学 | 347篇 |
基础医学 | 4276篇 |
口腔科学 | 998篇 |
临床医学 | 2101篇 |
内科学 | 7836篇 |
皮肤病学 | 848篇 |
神经病学 | 2224篇 |
特种医学 | 1269篇 |
外科学 | 5745篇 |
综合类 | 160篇 |
一般理论 | 1篇 |
预防医学 | 1010篇 |
眼科学 | 682篇 |
药学 | 2453篇 |
中国医学 | 46篇 |
肿瘤学 | 3614篇 |
出版年
2023年 | 148篇 |
2022年 | 320篇 |
2021年 | 574篇 |
2020年 | 332篇 |
2019年 | 415篇 |
2018年 | 531篇 |
2017年 | 497篇 |
2016年 | 522篇 |
2015年 | 578篇 |
2014年 | 753篇 |
2013年 | 928篇 |
2012年 | 1385篇 |
2011年 | 1530篇 |
2010年 | 888篇 |
2009年 | 814篇 |
2008年 | 1352篇 |
2007年 | 1350篇 |
2006年 | 1377篇 |
2005年 | 1475篇 |
2004年 | 1361篇 |
2003年 | 1388篇 |
2002年 | 1283篇 |
2001年 | 1296篇 |
2000年 | 1328篇 |
1999年 | 1199篇 |
1998年 | 399篇 |
1997年 | 336篇 |
1996年 | 302篇 |
1995年 | 283篇 |
1994年 | 250篇 |
1993年 | 239篇 |
1992年 | 821篇 |
1991年 | 728篇 |
1990年 | 733篇 |
1989年 | 700篇 |
1988年 | 713篇 |
1987年 | 624篇 |
1986年 | 614篇 |
1985年 | 597篇 |
1984年 | 391篇 |
1983年 | 325篇 |
1982年 | 148篇 |
1979年 | 319篇 |
1978年 | 204篇 |
1977年 | 151篇 |
1975年 | 149篇 |
1974年 | 213篇 |
1973年 | 151篇 |
1972年 | 165篇 |
1971年 | 147篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
A. Mori S. Urabe M. Asada Y. Tanaka H. Tazaki I. Yamamoto N. Kimura T. Ozawa S. T. Morris R. Hickson P. R. Kenyon H. Blair C. B. Choi T. Arai 《Transboundary and Emerging Diseases》2007,54(7):342-345
Concentrations of metabolites and immunoreactive insulin (IRI) and activities of enzymes related to energy metabolism were measured in plasma of Korean and Japanese beef cattle, which were raised by the indoor feeding system programmed to feed larger amount of roughage in their growing periods and larger amount of concentrate diet in their finishing periods (Japanese feeding system), and grazing New Zealand beef cattle. By the Japanese beef grading system, Korean and Japanese beef cattle showed high beef quality score, average grade 3.3 and 3.6, respectively. The plasma free fatty acid and lactate concentrations and lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and aspartate aminotransferase (AST) activities in Korean beef cattle were significantly higher than those in Japanese beef cattle. The plasma lactate concentration in Korean beef cattle was 8.40 mmol/l, which was similar to the values observed in lactic acidosis. The higher activities of plasma LDH, MDH and AST may indicate slight liver damage by slightly acidotic conditions in Korean beef cattle. New Zealand beef cattle fed on pasture which they harvest by grazing showed significantly lower plasma glucose, cholesterol, lactate and IRI concentrations and enzyme activities than those in Korean and Japanese beef cattle fed on larger amount of concentrate diets. Plasma metabolite concentrations and energy metabolism‐related enzyme activities may be good indicators for evaluating metabolic conditions of beef cattle raised by different feeding systems. 相似文献
82.
Atsushi Takai Yoshihiro Okabe Nobuhiro Aoki Mariko Takada Shuji Yamamoto Naoya Kimoto Mikio Fujita Akihiko Okada Chiharu Kawanami Yukinobu Takimoto Akio Orino 《Nihon Shokakibyo Gakkai zasshi》2007,104(10):1498-1503
A 77-year-old man, who underwent segmental pancreatectomy for intraductal papillary mucinous adenoma in 2001, was referred to our hospital with complaints of hematemesis and melena on January, 2004. Emergency upper gastrointestinal endoscopy showed a pulsating submucosal protrusion in the duodenal bulb, which was identified as a gastroduodenal arterial aneurysm measuring 1.5cm on abdominal CT imaging. Transcatheter arterial embolization of the aneurysm with metallic coils was successfully performed. Periodically repeated endoscopic examination has revealed the coils protruding into the duodenal lumen without any serious complication. 相似文献
83.
F Ichida A Yoshikawa M Mizokami M Yamamoto N Inaba H Takamizawa T Ohmura A Ohmizu J Ohata Y Uemura 《The Journal of international medical research》1988,16(3):231-236
The efficacy and safety of a recombinant yeast-derived hepatitis B vaccine were evaluated in 209 subjects after three administrations at 0, 4 and 20 weeks. Subjects were divided into four groups given 5 micrograms vaccine subcutaneously, 10 micrograms subcutaneously, 10 micrograms intramuscularly and 20 micrograms subcutaneously to define the effective dose and to compare the effect of administration. Seroconversion of the antibody to hepatitis B surface antigen after the third vaccination reached 96.6% in the group given 5 micrograms vaccine subcutaneously and 100% in the other groups. The final geometric mean antibody titres were 700 IU/l in subjects given 5 micrograms subcutaneously, 2004 IU/l in those given 10 micrograms subcutaneously, 4674 IU/l in those given 10 micrograms intramuscularly and 3342 IU/l in those given 20 micrograms subcutaneously. In the groups given 10 micrograms, the early seroconversion rate of the antibody to hepatitis B surface antigen and the geometric mean antibody titres after the third vaccination were significantly higher in subjects administered intramuscularly than subcutaneously (P less than 0.05). No major adverse effects were observed and minor reactions were the same as, or less than, those reported for the plasma-derived vaccine. Before and after administration, no significant fluctuation in the yeast antibody titre was observed. These results demonstrate the efficacy and safety of the yeast-derived vaccine, and show that 10 micrograms was the effective dose. 相似文献
84.
W Sakamoto T Kishimoto M Nishisaka H Iimori S Wada R Yasumoto K Yamamoto M Maekawa S Sukano K Umeyama 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1990,81(2):230-235
We retrospectively reviewed 32 patients who underwent parathyroidectomy at our hospital for the last fourteen years. 1) Clinical appearance of primary hyperparathyroidism was in younger age in women. 2) In previous history or at the time of PTX, 9 patients had malignant tumors including 6 thyroid cancers, 36% of the patients with out bone related symptoms had a remarkable decrease in bone mineral content. 3) After PTX, none of patients had recurrent urolithiasis and bone mineral content of all patients was significantly increased in a short time. In addition, upper GI complaints were improved, or hypertension was partially normalized. However, renal insufficiency remained unchanged. 4) In preoperative localization study, Ultrasound sonography (US) demonstrated the best accuracy rate of 88% when only one gland was involved. US was able to detect multiple gland involvement only in 20% of 5 cases. 5) Hypercalciuria was recognized as one of the risk factors of stone formation in patients with primary hyperparathyroidism. 相似文献
85.
86.
High Cell-Density Culture System of Hepatocytes Entrapped in a Three-Dimensional Hollow Fiber Module with Collagen Gel 总被引:2,自引:0,他引:2
Kazuyoshi Takeshita Haruaki Ishibashi Masayuki Suzuki Takumi Yamamoto Toshihiro Akaike Masashi Kodama 《Artificial organs》1995,19(2):191-193
Abstract: A compact three-dimensional (3D) module is needed for hepatocyte culture in order to develop an effective hybrid artificial liver system that can retain hepa-tocellular structure and differentiated functions. We treated the 3D module with collagen gel to entrap rat hepatocytes. This method yielded a high hepatocellular density (2 times 107 cells/ml) over a period of 14 days and maintained the secretion of albumin and ureogenesis at the same level as the control monolayer method. The ammonia removal remained at 43% of the Day 0 value over 8 days of perfusion. Our data show that this approach may be useful for liver support therapy in an ex-tracorporeal circuit. 相似文献
87.
Ryoji Tanei Tatsuo Yamamoto Hideki Yokono Tadashi Motoori 《The Journal of dermatology》1997,24(8):514-521
We report a case of an 81-year-old woman in whom lichenoid eruptions and Sjögren-like sicca syndrome developed 45 days after cholecystectomy. During surgery, one unit (130 ml) of unirradiated packed red blood cells from a male donor was transfused. The lichenoid eruptions cleared up with exfoliation; however, sicca symptoms remained during the follow-up period of four years. Histological examinations of both skin and lip biopsy specimens were in agreement with those of graft-versus-host disease (GVHD). A Y-chromosomal body was identified in the lymphocytes in the skin lesion by staining with quinacrine dihydrochloride and in the lip lesion by a method with in situ hybridization. The findings suggest that this case demonstrated the manifestations of non-fatal transfusion-associated GVHD. 相似文献
88.
Xianghua Zhang Fumio Tsukuda Norihito Yamamoto Ikumasa Takenaka 《International journal of urology》1997,4(5):519-521
Brain metastases from prostate cancer are rare in postmortem examinations, and even rarer in clinical series. We report an unusual case of brain metastasis from prostate cancer confirmed by antemortem diagnosis in a 72-year-old man. The metastatic brain tumor was surgically resected and the patient was kept stable for more than 19 months after diagnosis of the brain metastasis. 相似文献
89.
Highly potent and selective inhibition of human immunodeficiency virus by the bicyclam derivative JM3100. 总被引:19,自引:5,他引:14 下载免费PDF全文
E De Clercq N Yamamoto R Pauwels J Balzarini M Witvrouw K De Vreese Z Debyser B Rosenwirth P Peichl R Datema et al. 《Antimicrobial agents and chemotherapy》1994,38(4):668-674
Bicyclams, in which the cyclam (1,4,8,11-tetraazacyclotetradecane) moieties are tethered via an aliphatic bridge (i.e., propylene, as in JM2763) are potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) (E. De Clercq, N. Yamamoto, R. Pauwels, M. Baba, D. Schols, H. Nakashima, J. Balzarini, Z. Debyser, B. A. Murrer, D. Schwartz, D. Thornton, G. Bridger, S. Fricker, G. Henson, M. Abrams, and D. Picker, Proc. Natl. Acad. Sci. USA 89:5286-5290, 1992). We have now found that the bicyclam JM3100, in which the cyclam moieties are tethered by an aromatic bridge [i.e., phenylenebis(methylene)], inhibits the replication of various HIV-1 and HIV-2 strains in various cell lines at a 50% effective concentration (EC50) of 1 to 10 ng/ml, which is about 100-fold lower than the concentration required for JM2763 to inhibit HIV replication and at least 100,000-fold lower than the cytotoxic concentration (> 500 micrograms/ml). In primary T4 lymphocytes or primary monocytes, JM3100 proved inhibitory to HIV-1(IIIB) and several clinical HIV-1 isolates at an EC50 of less than 1 ng/ml. On the basis of time-of-addition experiments, JM3100 appeared to interact with a viral uncoating event, and this was further corroborated by an uncoating assay in which RNase sensitivity of [5-3H]uridine-labeled virions was monitored. In addition, but possibly mechanistically related, JM3100 blocks formation of infectious particles. JM3100 was also found to interfere directly with virus-induced syncytium formation, albeit at a higher concentration (1 to 2 microgram/ml) than that required for inhibition of viral replication. Following subcutaneous injection of 10 mg of JM3100 per kg of body weight to rabbits, anti-HIV activity was detected in serum corresponding to serum drug levels exceeding for at least 6 h by >100-fold the EC(50) required to inhibit HIV replication in vitro. When combined with either 3'-azido-2',3' -dideoxythymidine or 2',3' -dideoxyinosine, JM3100 achieved a additive inhibition of HIV replication, and when repeatedly subcultivated in the presence of JM3100, the virus remained sensitive to the compound for at least 30 passages (120 days) in cell culture. 相似文献
90.
H Masuzaki M Iwanishi M Umemiya K Misaki S Sumitomo N Fujimura M Kato S Heki M Kanaoka R Yamamoto 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(12):1644-1650
A 33-year-old man with a 6-month history of rhinitis and bronchial asthma was referred to our hospital with polyarthralgia, severe anemia, hypoxemia, mononeuropathy multiplex, and renal insufficiency with hematuria. Marked eosinophilia was observed in his sputum, peripheral blood, and bronchoalveolar lavage fluid (BALF). In addition, his sputum contained many hemosiderin-laden macrophages, indicative of pulmonary hemorrhage. His chest roentgenogram on admission showed diffuse ground grass appearance. High resolution computed tomography (HRCT) demonstrated diffuse high density areas throughout the lung fields and characteristic irregularity and enlargement of the peripheral pulmonary arteries. His general condition rapidly deteriorated, but dramatically improved with oral steroid administration, and his major symptoms disappeared within a few days. Examination of the biopsied lung tissue revealed unequivocal evidence of pulmonary angitis with marked eosinophilic infiltration and perivascular granulomas. Bone marrow biopsy showed hyperplasia of eosinophilic leukocytes in contrast to the low cellularity. Suppression of erythroid hemopoiesis was thought to be the primary cause for his rapidly progressive anemia. Serum anti-GBM antibody titer returned to within the normal range soon after the initiation of steroid therapy. 相似文献