全文获取类型
收费全文 | 2466篇 |
免费 | 124篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 43篇 |
妇产科学 | 21篇 |
基础医学 | 268篇 |
口腔科学 | 70篇 |
临床医学 | 109篇 |
内科学 | 569篇 |
皮肤病学 | 8篇 |
神经病学 | 255篇 |
特种医学 | 234篇 |
外科学 | 606篇 |
综合类 | 9篇 |
预防医学 | 52篇 |
眼科学 | 13篇 |
药学 | 129篇 |
中国医学 | 5篇 |
肿瘤学 | 173篇 |
出版年
2023年 | 15篇 |
2022年 | 20篇 |
2021年 | 39篇 |
2020年 | 24篇 |
2019年 | 28篇 |
2018年 | 48篇 |
2017年 | 35篇 |
2016年 | 69篇 |
2015年 | 49篇 |
2014年 | 47篇 |
2013年 | 75篇 |
2012年 | 111篇 |
2011年 | 124篇 |
2010年 | 51篇 |
2009年 | 57篇 |
2008年 | 108篇 |
2007年 | 111篇 |
2006年 | 94篇 |
2005年 | 113篇 |
2004年 | 117篇 |
2003年 | 124篇 |
2002年 | 115篇 |
2001年 | 90篇 |
2000年 | 125篇 |
1999年 | 94篇 |
1998年 | 56篇 |
1997年 | 31篇 |
1996年 | 28篇 |
1995年 | 22篇 |
1994年 | 19篇 |
1993年 | 16篇 |
1992年 | 58篇 |
1991年 | 47篇 |
1990年 | 40篇 |
1989年 | 46篇 |
1988年 | 32篇 |
1987年 | 34篇 |
1986年 | 36篇 |
1985年 | 39篇 |
1984年 | 23篇 |
1983年 | 26篇 |
1982年 | 15篇 |
1981年 | 9篇 |
1979年 | 14篇 |
1978年 | 9篇 |
1974年 | 14篇 |
1973年 | 10篇 |
1972年 | 14篇 |
1969年 | 9篇 |
1966年 | 15篇 |
排序方式: 共有2596条查询结果,搜索用时 15 毫秒
1.
Antigen presentation by a B-cell line transfected with cloned immunoglobulin heavy- and light-chain genes specific for a defined hapten. 总被引:5,自引:1,他引:4
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M Watanabe D R Wegmann A Ochi N Hozumi 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(14):5247-5251
The rearranged genes encoding immunoglobulin heavy (mu) and light (kappa) chains specific for the hapten 2,4,6-trinitrophenyl (Tnp) were introduced into a B-lymphoma line that bears surface IgG with an unknown specificity and expresses surface Ia molecules. A transformant expressing surface IgM specific for Tnp was obtained. The transformant was found to present Tnp-proteins to antigen (protein)-specific T cells far more efficiently than the parenteral B-lymphoma line. This artificial system, utilizing recombinant DNA technology and gene transfer, provides several approaches for the study of T-cell-B-cell interactions. 相似文献
2.
3.
Yuji Maruyama Shigeo Yamauchi Hidetsugu Ogasawara Hajime Imura Masami Ochi Kazuo Shimizu 《Annals of thoracic and cardiovascular surgery》2006,12(1):60-62
Surgical treatment for subacute pulmonary arterial thromboembolism has previously been considered to be inappropriate. We undertook a pulmonary arterial thrombectomy and removal of a floating right heart thrombus in a patient who had been symptomatic for over a month. The pulmonary arterial pressure, which had been equal to the systemic pressure preoperatively, decreased gradually and almost normalized one month postoperatively. Pulmonary perfusion scintigraphy revealed a dramatic improvement and the patient returned to normal life activities. 相似文献
4.
Hirofumi Nakanishi Akira Myoui Takahiro Ochi Katsuyuki Aozasa 《Journal of cancer research and clinical oncology》1997,123(6):352-356
Multidrug resistance (MDR) is an important problem in chemotheraphy for neoplastic disease. In humans, MDR is mainly mediated by P-glycoprotein (P-gp), a product of theMDR1 gene, which acts as a transmembrane protein pump and eliminates chemotherapeutic agents from the cells. Expression of P-gp was immunohistochemically studied by using two monoclonal antibodies, JSB-1 and C-219, on paraffin-embedded sections from 55 patients with soft-tissue sarcoma. The histological diagnosis of tumors was malignant fibrous histiocytoma in 24 cases, liposarcoma in 9, synovial sarcoma in 7, malignant neurogenic tumors in 6, leiomyosarcoma in 5, others in 4. The histological grade was determined on the basis of criteria previously proposed by us. Out of 55 cases, 34 (62%) were positive for P-gp expression. There was a significant difference in P-gp expression between high-grade (90%) and intermediate and low-grade tumors (46%) (P<0.005). Tumors expressing P-gp had a less favorable prognosis than P-gp-negative tumors in the high- and intermediate-grade tumors. The current study demonstrated that the estimation of P-gp expression could be used to select appropriate therapeutic modalities.Abbreviations
MDR
multidrug resistance
-
P-gp
P-glyco-protein 相似文献
5.
S Shibata A Ochi H Yamashita A Yasunaga K Mori 《No shinkei geka. Neurological surgery》1990,18(6):527-531
The tumor vessels of a primary meningeal malignant melanoma were studied by electron microscopy. There were numerous endothelial fenestrae and basal lamina abnormalities in the intrinsic tumor capillaries. They resembled the tumor vessels found in nonglial tumors, but were distinctly different from those seen in glial tumors with nonfenestrated capillaries. These findings were anticipated because leptomeninges have fenestrated capillaries. 相似文献
6.
Kiyoshi Nakatsuka Yoshiki Nishizawa Satoshi Hagiwara Hidenori Koyama Takami Miki Hironobu Ochi Hirotoshi Morii 《Calcified tissue international》1990,47(6):378-382
Summary Total body bone mineral (TBBM) content in rats was measured by dual photon absorptiometry (DPA). TBBM showed significant increases
over 4 weeks in control groups with significant bone loss over the same time in prednisolone-injected rats on low calcium
feed. Daily injections of calcitonin significantly reduced loss of bone mass. Both prednisolone- and prednisolone-calcitonin-injected
groups showed significantly elevated serum alkaline phosphatase with the prednisolone-calcitonin group also exhibiting elevated
serum calcium and phosphate levels, confirming the impact of the experimental protocol. TBBM measured by DPA in all groups
correlated well (r=0.928,P<0.001 n=20) with the total ash weight suggesting that the method reflects total skeletal mineral content in the small animal.
TBBM measurement by DPA proves well-suited to monitoring bone mineral in a small animal experimental setting. 相似文献
7.
Protective effect of prostaglandins D2, E1 and I2 against cerebral hypoxia/anoxia in mice 总被引:3,自引:0,他引:3
Yoshinobu Masuda Yuko Ochi Yoshiaki Ochi Tadahiko Karasawa Naonobu Hatano Toshiaki Kadokawa Masanao Shimizu 《Naunyn-Schmiedeberg's archives of pharmacology》1986,334(3):282-289
The protective effect of prostaglandins (PGs) against cerebral hypoxia/anoxia was investigated with a variety of experimental models in relation to their CNS depressant effects in mice. Furthermore, the effect of PGs on the changes of cerebral energy metabolites and cyclic nucleotide was examined in hypoxic mice. Mice were given s.c. doses of PGs 30 min before tests. Among the PGs tested, treatment with PGD2, PGE1 and PGI2 Na showed a consistent and dose-dependent protection against cerebral anoxia induced by all models studied: histotoxic anoxia by KCN, hypobaric hypoxia, normobaric hypoxia and decapitation-induced gasping. However, PGA1, PGA2, PGB1, PGB2, PGE2, PGF1 alpha, PGF2 alpha and 6-keto-PGF1 alpha at a dose of 3 mg/kg were without effect against normobaric hypoxia and gasping duration. The three PGs, i.e. PGD2, PGE1 and PGI2 which showed anti-hypoxic effects decreased locomotor activity and potentiated hexobarbital-induced sleep. On the other hand, PGE2, PGA1, PGA2 and PGB2 also caused a decrease in locomotor activity. Similarly, PGE2 and PGA1 caused a potentiation of hexobarbital-induced sleep, but interestingly they did not cause clear-cut increase in cerebral resistance to hypoxia, in contrast with the former three PGs. Thus general depression of CNS function appears not to be responsible for the PGD2-, PGE1- and PGI2-induced increase in cerebral resistance to hypoxia. The levels of Cr-P and ATP were significantly reduced and those of ADP and AMP were markedly elevated in hypoxic brain, resulting in a decrease in a calculated energy charge potential. The lactate level and lactate/pyruvate ratio increased and the glucose level decreased markedly.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
8.
The effects of prior 24-hour ureteral obstruction on ischemic renal damage were studied in rats. Rats were divided into 6 groups with different times of ischemia (0, 60 and 90 min) and with or without 24-hour ureteral obstruction. Following a 4-week recovery period, contralateral nephrectomy was performed and the rat was sacrificed 24 h later for the determination of serum creatinine and for histologic examination of the affected kidney. A preceding ureteral obstruction for 24 h made no difference to the renal damage with 60 min of ischemia or without ischemia. However, kidneys with 90 min of ischemia and 24 h of ureteral obstruction were more damaged than those with 90 min of ischemia only. These results suggested that the hydronephrotic kidney was more susceptible to long periods of ischemia than the normal kidney. 相似文献
9.
Takashi Natsuume Norimasa Nakamura Konsei Shino Yukiyoshi Toritsuka Shuji Horibe Takahiro Ochi 《Journal of orthopaedic research》1997,15(6):837-843
We investigated the temporal and spatial expression of transforming growth factor-β in the healing patellar ligament of the rat by immunohistochemistry. The mid-portion of the medial half of the patellar ligament in 14-week-old male Wistar rats was cut transversely with a scalpel. On day 1 after ligament injury, diffuse staining for transforming growth factor-β was observed in the extracellular matrix filling the wound, and the staining in the adjacent ligament tissue was as weak as it was in the normal ligament. On day 3, the intensity of the diffuse extracellular staining decreased, and the staining was observed in correspondence with the cellular distribution in the wound site and in the adjacent uninjured ligament tissue. On day 7, the intense staining was widely distributed over the whole length of the ligament tissue. On day 28, the staining for transforming growth factor-β was still observed at the wound site and in the adjacent uninjured ligament tissue, where the staining was reduced in intensity but still stronger than it was in the normal ligament. On day 56, the expression of transforming growth factor-β was still detectable at the wound site: however, in the adjacent uninjured ligament tissue, it had almost subsided to the normal level. The results of the present study suggest that ligament healing may be accompanied by extensive changes in the expression of transforming growth factor-β over the whole length of ligament tissue. 相似文献
10.
Clinical Evaluation of a New Type of Centrifugal Pump 总被引:2,自引:0,他引:2
J. Ninomiya T. Shoji S. Tanaka M. Ikeshita M. Ochi S. Yamauchi T. Yajima H. Yamauchi T. Sugimotox T. Aizawa 《Artificial organs》1994,18(9):702-705
Abstract: The major problems with existing centrifugal pumps are leakage, mechanical trauma, and thrombus formation. In consideration of these problems, a new compact centrifugal pump system was developed. The purpose of this study was to evaluate the new centrifugal pump system clinically. Ten patients underwent open heart surgery with a centrifugal pump or a roller pump. During surgery, hemodynamic and hematological data were obtained. A pulsatile assist device in the pump circuit was used in patients with severe heart disease. There was neither operative death nor hospital mortality, and there was no difference with regard to hemodynamic data between the two groups. The centrifugal pump group, however, had significantly lower hemolysis, especially during prolonged cardiopulmonary bypass. This centrifugal pump could also create sufficient pulsatile flow with a pulsatile assist device. Postoperative macroscopic and microscopic findings demonstrated the smooth surface of the pump without thrombus formation. This centrifugal pump system might be useful for prolonged cardiopulmonary bypass. 相似文献