全文获取类型
收费全文 | 1334768篇 |
免费 | 96043篇 |
国内免费 | 2910篇 |
专业分类
耳鼻咽喉 | 19729篇 |
儿科学 | 40249篇 |
妇产科学 | 38673篇 |
基础医学 | 187324篇 |
口腔科学 | 39835篇 |
临床医学 | 112622篇 |
内科学 | 262430篇 |
皮肤病学 | 30220篇 |
神经病学 | 106393篇 |
特种医学 | 53689篇 |
外国民族医学 | 435篇 |
外科学 | 208486篇 |
综合类 | 31040篇 |
现状与发展 | 6篇 |
一般理论 | 437篇 |
预防医学 | 92000篇 |
眼科学 | 31374篇 |
药学 | 100124篇 |
3篇 | |
中国医学 | 2991篇 |
肿瘤学 | 75661篇 |
出版年
2018年 | 11772篇 |
2015年 | 11906篇 |
2014年 | 16721篇 |
2013年 | 25290篇 |
2012年 | 33067篇 |
2011年 | 34950篇 |
2010年 | 20775篇 |
2009年 | 20260篇 |
2008年 | 33623篇 |
2007年 | 36744篇 |
2006年 | 37318篇 |
2005年 | 36082篇 |
2004年 | 35156篇 |
2003年 | 34116篇 |
2002年 | 33653篇 |
2001年 | 63647篇 |
2000年 | 65369篇 |
1999年 | 55420篇 |
1998年 | 14671篇 |
1997年 | 13474篇 |
1996年 | 12950篇 |
1995年 | 12236篇 |
1994年 | 11470篇 |
1992年 | 42775篇 |
1991年 | 41295篇 |
1990年 | 40566篇 |
1989年 | 39566篇 |
1988年 | 36973篇 |
1987年 | 36416篇 |
1986年 | 34905篇 |
1985年 | 33107篇 |
1984年 | 24829篇 |
1983年 | 21056篇 |
1982年 | 12666篇 |
1981年 | 11573篇 |
1980年 | 10777篇 |
1979年 | 23930篇 |
1978年 | 17070篇 |
1977年 | 14836篇 |
1976年 | 13389篇 |
1975年 | 15270篇 |
1974年 | 18082篇 |
1973年 | 17562篇 |
1972年 | 16816篇 |
1971年 | 15718篇 |
1970年 | 14919篇 |
1969年 | 14350篇 |
1968年 | 13463篇 |
1967年 | 12016篇 |
1966年 | 11258篇 |
排序方式: 共有10000条查询结果,搜索用时 593 毫秒
881.
882.
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
883.
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
884.
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
885.
Fourty-four narcotized rats were split into two equal groups, one being treated with nimodipine and the other with a placebo. By use of norfenefrine the blood pressure was raised to values of 150 and 180 mm Hg within the limits of the autoregulation of brain perfusion and under continuous measurement. Fifteen minutes after application of the standard tracer, horseradish peroxidase, the animals were exsanguinated using a saline perfusion and then perfusion-fixed with Karnovsky's solution. After development of the peroxidase staining the brain sections were evaluated and then allocated to their respective groups. In brain tissues from the experimental group significantly more frequent perivascular accumulations of horseradish peroxidase reaction product were found (P less than 0.001). In electron micrographs it could be seen that the tight junctions were intact and that there was a neuroendothelial transport, with horseradish peroxidase-filled vesicles, in the endothelium, muscle cells, and brain parenchyma. These vesicles represent a medium of transport for all proteins of high molecular weight and can therefore result in brain edema. It is concluded that nimodipine damages the blood-brain barrier by disturbance of the autoregulation of the cerebral blood flow. 相似文献
886.
887.
888.
Denis Nissim-Sabat William H. Farr Kathleen McCune Melanie Stith 《Community mental health journal》1986,22(2):160-165
This study represents the first of a two-stage project. The first phase of the study examined the funding sources for the 40 Community Services Boards in Virginia. Data provided from the Department of Mental Health and Mental Retardation in Virginia examined fee collections which are comprised of direct client, commercial insurance, Medicaid and Medicare. An analysis of quarterly reports from 1982 to 1984 revealed that Medicaid collections have decreased significantly, while commercial insurance reimbursements have increased significantly. These results, although limited to data from Virginia, point to the need to examine if these shifts are occurring nation-wide, and to determine if the shift toward commercial insurance is impacting upon the delivery of services in Community Mental Health Centers. 相似文献
889.
Slowly progressive aphasia without generalized dementia: studies with positron emission tomography 总被引:14,自引:0,他引:14
J B Chawluk M M Mesulam H Hurtig M Kushner S Weintraub A Saykin N Rubin A Alavi M Reivich 《Annals of neurology》1986,19(1):68-74
Slowly progressive aphasia without generalized dementia is a degenerative syndrome selectively affecting dominant hemisphere language areas. We report changes in regional glucose metabolism measured by positron emission tomography in two patients with this condition. Striking abnormalities of glucose utilization in the left cerebral cortex were demonstrated in both patients. The findings of other neurodiagnostic studies were relatively unremarkable. The first patient had a 3-year history of progressive anomia and impaired auditory verbal recall. An electroencephalogram was normal, and computed tomography showed mild left perisylvian atrophy. Positron emission tomography revealed profound hypometabolism in the left temporal regions. The second patient also had a 3-year history of progressive anomia. Electroencephalography, computed tomography, and magnetic resonance imaging scans were normal. Positron emission tomography showed a major reduction in left parietal glucose utilization, with a lesser decrement in left temporal metabolism. Neither patient demonstrated significant contralateral or global abnormalities such as those reported in positron emission tomographic studies of Alzheimer's disease with or without focal clinical features. These observations support the concept of adult-onset progressive aphasia without dementia as a clinical syndrome distinct from Alzheimer's disease. 相似文献
890.
K Murata H Itoh G Todo T Itoh M Kanaoka M Furuta K Torizuka 《Investigative radiology》1986,21(1):24-30
This study was undertaken to clarify the microvascular anatomy of the normal human bronchial circulation, focusing on the bronchial venous system and its communication with the pulmonary circulation. Ten normal lungs obtained at autopsy were studied. Bronchial arteriography was performed in six lungs, pulmonary arteriography in two lungs, and pulmonary venography in another two. Using radiologic methods, including microradiography, and serial histologic sections, we found numerous bronchial venous plexuses around the airways and blood vessels into which the bronchial capillaries drained. Frequent communications of the venous plexuses with the pulmonary veins and neighboring alveolar capillaries were also demonstrated. The bronchial venous plexus and its close connection with the pulmonary circulation may be important in various pathologic conditions involving the interstitial space, such as interstitial pulmonary edema. 相似文献