全文获取类型
收费全文 | 2943篇 |
免费 | 156篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 228篇 |
妇产科学 | 65篇 |
基础医学 | 349篇 |
口腔科学 | 43篇 |
临床医学 | 229篇 |
内科学 | 490篇 |
皮肤病学 | 68篇 |
神经病学 | 162篇 |
特种医学 | 83篇 |
外科学 | 383篇 |
综合类 | 99篇 |
预防医学 | 137篇 |
眼科学 | 54篇 |
药学 | 367篇 |
中国医学 | 18篇 |
肿瘤学 | 296篇 |
出版年
2023年 | 14篇 |
2022年 | 57篇 |
2021年 | 91篇 |
2020年 | 35篇 |
2019年 | 68篇 |
2018年 | 82篇 |
2017年 | 57篇 |
2016年 | 96篇 |
2015年 | 89篇 |
2014年 | 128篇 |
2013年 | 137篇 |
2012年 | 158篇 |
2011年 | 212篇 |
2010年 | 116篇 |
2009年 | 81篇 |
2008年 | 134篇 |
2007年 | 149篇 |
2006年 | 157篇 |
2005年 | 118篇 |
2004年 | 122篇 |
2003年 | 111篇 |
2002年 | 88篇 |
2001年 | 52篇 |
2000年 | 50篇 |
1999年 | 52篇 |
1998年 | 25篇 |
1997年 | 14篇 |
1996年 | 23篇 |
1995年 | 18篇 |
1994年 | 23篇 |
1992年 | 31篇 |
1991年 | 20篇 |
1990年 | 33篇 |
1989年 | 33篇 |
1988年 | 36篇 |
1987年 | 30篇 |
1986年 | 32篇 |
1985年 | 30篇 |
1984年 | 25篇 |
1983年 | 26篇 |
1981年 | 12篇 |
1979年 | 27篇 |
1977年 | 14篇 |
1976年 | 12篇 |
1974年 | 23篇 |
1972年 | 16篇 |
1971年 | 17篇 |
1970年 | 12篇 |
1968年 | 16篇 |
1967年 | 15篇 |
排序方式: 共有3103条查询结果,搜索用时 11 毫秒
11.
Mehta H Mahajan A Bansal N Vaidya S Pathak L 《The Journal of the Association of Physicians of India》1998,46(11):953-956
The above discussion on the interaction of aspirin and ACE inhibitors seems to suggest that aspirin in high doses may have adverse interaction with ACE inhibitors in patients with heart failure but the data obtained is not sufficient or conclusive to recommended omission of aspirin in patients with heart failure. This raises a query in the mind of the physician whether to use a combination or not? The role of aspirin in the early period after myocardial infarction is well established so is the role of ACE inhibitors. Hence in patients with myocardial infarction and preserved left ventricular function it would not be wrong to administer combination of ACE inhibitors and aspirin. Albeit at a lower dose. In patients with large myocardial infarction or heart failure, warfarin may be an option but still needs to be documented in large trials. As suggested long term use of aspirin after infarction is still ambiguous and may be harmful in patients with heart failure with its anticedent side effects. But long term benefits of ACE inhibitors in heart failure are well documented. Hence if a choice has to be made whether to discontinue either of the two drugs it would be preferable to stop the aspirin. To answer the issue of use of aspirin in patients with heart failure it would be essential to conduct a double blind randomized trial comparing known anti-thrombotic treatment, aspirin and anti-coagulants on mortality in patients with heart failure, especially caused by coronary artery disease. Such a trial is underway at the present and till the results are available it should be left to clinical judgement of the physician whether to administer aspirin in patients with heart failure after weighing the benefits versus risk. 相似文献
12.
Water-clear cell hyperplasia is a rare but well-documented cause of primary hyperparathyroidism. Parathyroid adenomas of water-clear cell type are exceptionally rare, and only five case reports are available at present in the medical literature. We report an additional case of water-clear cell adenoma of the parathyroid gland, and the differential diagnoses are discussed. 相似文献
13.
Tandon M Kapil U Bahadur S Dwivedi SN Pathak P 《The Journal of the Association of Physicians of India》2000,48(10):995-998
Cancer of the larynx is fourteenth most common cancer in the world. Evidence from case-control studies conducted in developed as well as developing countries suggest that specific micro-nutrients and trace elements have been implicated to be significantly associated with laryngeal carcinoma. The association of these micro-nutrients and trace elements with laryngeal cancer has been discussed in this review article. 相似文献
14.
S. K. Pathak K. Y. Tsang M. K. Cathcart P. Arnaud B. Boutin H. H. Fudenberg 《Immunology letters》1985,10(6):339-346
Human T cell hybridomas were established by fusion of PHA-activated PBL with the 8-azaguanine resistant human T-leukemic cell line CEM-CM3. High levels of B cell growth factor (BCGF) activity were detected in the supernatants of hybridoma C8-2B2 and its subclones. Hybridoma C8-2B2, in addition to the Leu 3a, also expressed the OKT11 surface marker which was not detectable on the parent CEM-CM3 cells. BCGF from the culture supernatant was purified by combined use of salt fractionation and gel filtration to 36.6 fold with 23.9% recovery of activity. The BCGF produced by hybridoma C8-2B2 has a molecular weight range of 16,000–20,000 in two major electrophoretically different forms with pI values of 6.4 and 7.4. 相似文献
15.
The restorative effect of naps on perceptual deterioration 总被引:4,自引:0,他引:4
Mednick SC Nakayama K Cantero JL Atienza M Levin AA Pathak N Stickgold R 《Nature neuroscience》2002,5(7):677-681
Human performance on visual texture discrimination tasks improves slowly (over days) in the absence of additional training. This 'slow learning' requires nocturnal sleep after training and is limited to the region of visual space in which training occurred. Here, we tested human subjects four times in one day and found that with repeated, within-day testing, perceptual thresholds actually increased progressively across the four test sessions. This performance deterioration was prevented either by shifting the target stimuli to an untrained region of visual space or by having the subjects take a mid-day nap between the second and third sessions. 相似文献
16.
M. Mishra U. N. Pathak A. B. Khan 《International journal of experimental pathology》1981,62(5):526-528
Twelve albino rabbits of either sex weighing 1.0-1.25 kg were fed a standard laboratory diet of green grass and sattu (roasted Bengal gram). After a 2-week run-in period their serum cholesterol levels were estimated. All animals were now fed 0.5 g cholesterol and 1.0 g clarified butter daily and were not divided into 3 groups of 4 animals each. While all received the standard cholesterol-rich diet, Group A animals received no additional substances, animals in Group B were each fed 10 mg vitamin C daily, while those in Group C were each given 1.0 g fresh Amla (Emblica officinalis Gaertn). Mean serum cholesterol levels in all three groups rose to significantly higher levels by the end of the second week. There was a further rise by the end of the third and fourth weeks in Groups A and B. However, animals in Group C (i.e. those given Amla) showed significantly lower mean serum cholesterol levels at the end of the second week than their counterparts in Groups A and B. At the end of the third and fourth weeks the differences were even more pronounced. 相似文献
17.
Interferon Production by Macrophages from Adult and Newborn Rabbits Bearing Fibroma Virus-Induced Tumors 总被引:2,自引:0,他引:2 下载免费PDF全文
Tumors were induced in adult and newborn rabbits by inoculation of fibroma virus. After 10 to 14 days, oil-induced peritoneal macrophages were harvested, purified, and tested in vitro for interferon synthesis after stimulation with specific and nonspecific viruses. Peritoneal macrophages from adult rabbits that had initiated tumor regression produced high levels of interferon (titers ranged from 160 to 640) after stimulation with fibroma virus, whereas macrophages from normal adult rabbits failed to produce significant levels of interferon under the same conditions (titers ranged from <10 to 10). Furthermore, fibroma-immune macrophages responded to vaccinia virus and Newcastle disease virus with higher levels of interferon than did normal macrophages. In contrast, macrophages from newborn tumor-bearing rabbits that showed no evidence of tumor regression failed to respond to fibroma virus stimulation with higher levels of interferon (titers ranged from <10 to 10). These macrophages did, however, yield significantly more interferon than newborn control macrophages when stimulated with a good interferon inducer, Newcastle disease virus (titers ranged from 10 to 80). These data suggest that interferon production may be an expression of macrophage activation to fibroma antigens and that macrophage activation is impaired in newborn rabbits with progressive growing tumors. 相似文献
18.
Vesnarinone, (3,4-dihydro-6-[4-(3,4-dimethoxybenzoyl)-1- piperazinyl]-2(1H)-quinolinone), a quinolinone derivative, is a positive inotropic agent. We examined the cytotoxicity either by vesnarinone alone or in combination with doxorubicin (DXR), in vitro. The cytotoxic effect of vesnarinone against HL-60 cells did not increase, even at concentrations as high as (50 mu g/ml). The cytotoxicity of DXR, however, was enhanced after being combined with 30 mu g/ml of vesnarinone. The intracellular level of DXR increased when DXR was administered after incubation with vesnarinone and the efflux of DXR was delayed when the cells were incubated in the presence of vesnarinone after DXR exposure. Flow cytometry showed that the combination of DXR and vesnarinone increased the cell population below the G(0)/G(1) region. Vesnarinone induced DNA ladder formation, but only when these cells were incubated for 72 h, while in addition, when DXR was combined with vesnarinone, the DNA ladder formation was enhanced. Based on the above findings, we thus conclude that the cytotoxicity of DXR was enhanced when combined with vesnarinone. 相似文献
19.
The MDA-MB-435 human breast cancer cell line metastasizes from tumors growing in the mammary fatpad of nude mice; metastases are found in the lymph nodes and lungs of 75 to 100% of tumor-bearing mice, and at a lower incidence in other organs such as the heart, skeletal muscle, adrenal gland and brain. Variants of this breast cancer cell line were established from metastases in different organs, including the lungs and brain of nude mice; these lines were designated 435-Lung2 and 435-Br1, respectively. Karyotypic analysis of the new variants suggested a clonal origin for the different organ metastases. The lung-derived cells were as metastatic as the original cell line when re-injected in nude mice, yet the cells from the brain metastasis produced few metastases. Analyses of the invasive potential of the cell lines showed that they did not differ in expression of mRNA for 72-kDa type IV-collagenase, or in gelatinase activity (by zymography), or in ability to invade through a Matrigel-coated filter. The poorly metastatic 435-Br1 cells showed reduced binding to cultured monolayers of mouse lung-endothelial cells, compared with the metastatic 435-Lung2 and MDA-MB-435 cells. When the breast cancer cells were artificially arrested in the lungs of nude mice, by injecting Cytodex beads coated with cells, all three cell lines grew equally well, suggesting that the deficiency found in the metastatic potential of the 435-Br1 cells may be associated with interactions with endothelial cells, rather than growth potential in the lungs. Further comparisons of these two metastasis-derived variants of a heterogeneous cell line will lead to greater understanding of the metastatic phenotype of human breast cancer. 相似文献
20.
Burke TA McKee JR Pathak DS Donahue RM Parasuraman TV Batenhorst AS 《American journal of mental retardation : AJMR》1999,104(2):148-157
Epilepsy is a significant comorbid condition in institutionalized persons with developmental disabilities and may contribute significant additional costs. This study was conducted to provide an estimate of the costs of epilepsy from the institutional perspective. Costs were measured retrospectively for 50 persons with epilepsy and 50 persons without epilepsy matched by severity of developmental disability. A time and motion study was employed to assign opportunity costs to documented nursing and physician activities. Two separate methods of attribution were used and incremental costs attributable to epilepsy were found to be approximately $825 and $918 per person over a 6-month period. The following categories accounted for costs: personnel (47.0%), drug (39.6%), hospitalization (9.4%), and laboratories/procedures (4.0%). Results are useful for describing the economic burden of epilepsy. 相似文献