全文获取类型
收费全文 | 3438619篇 |
免费 | 251554篇 |
国内免费 | 6276篇 |
专业分类
耳鼻咽喉 | 50386篇 |
儿科学 | 111396篇 |
妇产科学 | 99046篇 |
基础医学 | 488615篇 |
口腔科学 | 103001篇 |
临床医学 | 299190篇 |
内科学 | 660550篇 |
皮肤病学 | 75560篇 |
神经病学 | 274432篇 |
特种医学 | 134870篇 |
外国民族医学 | 1180篇 |
外科学 | 526104篇 |
综合类 | 81364篇 |
现状与发展 | 10篇 |
一般理论 | 1162篇 |
预防医学 | 258863篇 |
眼科学 | 82208篇 |
药学 | 260393篇 |
8篇 | |
中国医学 | 6851篇 |
肿瘤学 | 181260篇 |
出版年
2018年 | 31842篇 |
2015年 | 31762篇 |
2014年 | 44060篇 |
2013年 | 67839篇 |
2012年 | 90798篇 |
2011年 | 96695篇 |
2010年 | 57389篇 |
2009年 | 54443篇 |
2008年 | 92859篇 |
2007年 | 99743篇 |
2006年 | 101106篇 |
2005年 | 98636篇 |
2004年 | 96030篇 |
2003年 | 92691篇 |
2002年 | 91183篇 |
2001年 | 154245篇 |
2000年 | 158863篇 |
1999年 | 135247篇 |
1998年 | 38186篇 |
1997年 | 34320篇 |
1996年 | 33882篇 |
1995年 | 32357篇 |
1994年 | 30441篇 |
1993年 | 28450篇 |
1992年 | 109479篇 |
1991年 | 106833篇 |
1990年 | 104931篇 |
1989年 | 102319篇 |
1988年 | 95242篇 |
1987年 | 93839篇 |
1986年 | 89539篇 |
1985年 | 85847篇 |
1984年 | 64418篇 |
1983年 | 55731篇 |
1982年 | 33137篇 |
1981年 | 29712篇 |
1980年 | 27953篇 |
1979年 | 62012篇 |
1978年 | 43840篇 |
1977年 | 37582篇 |
1976年 | 35017篇 |
1975年 | 38339篇 |
1974年 | 46161篇 |
1973年 | 44593篇 |
1972年 | 42203篇 |
1971年 | 39471篇 |
1970年 | 36916篇 |
1969年 | 35216篇 |
1968年 | 32896篇 |
1967年 | 29475篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
962.
963.
964.
A protein from rat testes that catalyzes the oxidation of ethanolin the presence of NAD+, but not NADP+, has been characterizedenzymatically and compared to that of hepatic alcohol dehydrogenaseobtained from the same animals. The testicular enzyme, likethe hepatic enzyme, has a Km value for ethanol in the 0.51.0-mMrange and can utilize other alcohols such as n-propanol, n-butanol,and isobutanol, although the Km values for these other alcoholsare considerably lower (0.030.08 mM) that that for ethanol.The testicular enzyme is more heat-labile than is the hepaticenzyme. Finally, the testicular enzyme catalyzes the oxidationof retinol and its retinol dehydrogenase activity is inhibitedby ethanol. 相似文献
965.
966.
Medicaid families under managed care. Anticipated behavior 总被引:1,自引:0,他引:1
H Temkin-Greener 《Medical care》1986,24(8):721-732
This study reports the results of a household survey of 495 Medicaid clients eligible under the Aid to Families with Dependent Children program in Monroe County, New York. The purpose of the study has been to examine the views and to anticipate the health care choices/decisions of Medicaid clients prior to their enrollment in a new, county-wide Medicaid-managed care program. The findings indicate significant ethnic differentials among the Medicaid poor, both in the choice of care source and in the reasons offered for that choice. Forty percent of those interviewed would like to change to a new source of care, but less than 13% can actually be expected to change. Private practice arrangements were the preferred source of care, yet distance to such sources appears to represent a major stumbling block to access. This study suggests that the managed-care approach being offered in Monroe County may offer the Medicaid eligibles a new stigma-free way of affiliating with a health care provider. This is being recognized by those surveyed as an important element. The study demonstrates that the choices made by the Medicaid recipients are perfectly rational given the recipients' knowledge of Medicaid and the health care system, and the general conditions in which they find themselves. These findings have important implications for the move of Medicaid programs from the fee-for-service to the managed-care/HMO system. 相似文献
967.
We describe a case of pathologic jealousy (Othello syndrome) in a patient with Parkinson disease, which abated after discontinuing amantadine. We indicate that early recognition and treatment of the syndrome in this disease may avert physical violence. We also believe that our report further suggests a link between this specific behavioral disorder and dopaminergic activity. 相似文献
968.
A case of Ullrich disease was presented. The patient was a 3-year-old girl with torticollis, generalized muscle weakness and acroatonia since birth. High-arched palate, protruded calcaneus, and mild contracture of proximal joints were also recognized. Intellectual development was normal. Serum level of CPK was slightly increased. In histological and histochemical examinations of quadriceps femoris muscle, proliferated connective tissue, marked variation in the muscle fiber diameter, and a lot of degenerated and regenerated fibers were recognized. Minimal injury easily causes subcutaneous hemorrhage, but no abnormality was found in the structure of collagen. 相似文献
969.
K J Meador J L Thompson D W Loring A M Murro D W King B B Gallagher G P Lee J R Smith H F Flanigin 《Neurology》1991,41(6):869-872
Although there has been extensive examination of the behavioral and physiologic correlates of hippocampal theta activity in animals, the human literature consists of a single case study. We investigated the differential effects of four behavioral states on human hippocampal theta activity in 16 epilepsy surgery patients. Behavioral conditions included resting eyes closed (RC), resting eyes open (RO), eyes open with auditory word activation (AW), and eyes open with visuospatial activation (VS). Hippocampal theta activity decreased during both RO and VS compared to both RC and AW. There were reciprocal changes in delta activity. Comparisons of RO to VS and of RC to AW were nonsignificant. The results demonstrate state-specific changes in human hippocampal theta and are consistent with the animal literature that relates hippocampal theta to sensorimotor integration and forebrain volitional mechanisms. 相似文献
970.
J Elidan E Leibner S Freeman M Sela M Nitzan H Sohmer 《Electroencephalography and clinical neurophysiology》1991,80(2):140-145
We have succeeded in recording short and middle latency vestibular evoked responses in human subjects. The head was held rigidly in a special, patented head holder, constructed individually for each subject, which gripped the teeth of the upper jaw. The stimulus consisted of 2/sec steps of angular acceleration impulses produced by a special motor with intensities of about 10,000 degrees/sec 2 and with a rise time of 1-2 msec. The electrical activity was recorded as the potential difference between special forehead and mastoid electrodes having a large, secure contact area with the skin. The activity was digitally filtered and averaged in 2 separate channels by means of a Microshev 2000 evoked response system. The short latency responses, with peaks at about 3.5 msec (forehead positive), 6.0 msec (forehead negative) and 8.4 msec (forehead positive; bandpass: 200-2000 Hz; average of 1024 trials), had amplitudes of about 0.5 microV. The middle latency responses had peaks at about 8.8 msec (forehead positive), 18.8 msec (forehead negative) and 26.8 msec (forehead positive; 30-300 Hz; N = 128 trials), with larger amplitudes (about 15 microV). These responses were consistently recorded in the same subject at different times and were similar in different normal subjects. Strenuous control experiments were conducted in order to ensure that these responses are not artefacts due to the movement of conducting media (head, electrodes and leads) in the electromagnetic field of the motor and are elicited by activation of normal labyrinths.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献