全文获取类型
收费全文 | 31348篇 |
免费 | 2610篇 |
国内免费 | 687篇 |
专业分类
耳鼻咽喉 | 238篇 |
儿科学 | 1280篇 |
妇产科学 | 778篇 |
基础医学 | 1766篇 |
口腔科学 | 908篇 |
临床医学 | 3642篇 |
内科学 | 6502篇 |
皮肤病学 | 405篇 |
神经病学 | 1328篇 |
特种医学 | 786篇 |
外国民族医学 | 1篇 |
外科学 | 2936篇 |
综合类 | 4207篇 |
现状与发展 | 1篇 |
预防医学 | 4839篇 |
眼科学 | 334篇 |
药学 | 2258篇 |
36篇 | |
中国医学 | 1145篇 |
肿瘤学 | 1255篇 |
出版年
2024年 | 149篇 |
2023年 | 886篇 |
2022年 | 1709篇 |
2021年 | 2187篇 |
2020年 | 1871篇 |
2019年 | 1716篇 |
2018年 | 1698篇 |
2017年 | 1262篇 |
2016年 | 1169篇 |
2015年 | 1104篇 |
2014年 | 2324篇 |
2013年 | 2183篇 |
2012年 | 1826篇 |
2011年 | 1975篇 |
2010年 | 1594篇 |
2009年 | 1520篇 |
2008年 | 1402篇 |
2007年 | 1436篇 |
2006年 | 1031篇 |
2005年 | 938篇 |
2004年 | 726篇 |
2003年 | 609篇 |
2002年 | 419篇 |
2001年 | 399篇 |
2000年 | 277篇 |
1999年 | 269篇 |
1998年 | 213篇 |
1997年 | 202篇 |
1996年 | 173篇 |
1995年 | 169篇 |
1994年 | 158篇 |
1993年 | 122篇 |
1992年 | 133篇 |
1991年 | 116篇 |
1990年 | 89篇 |
1989年 | 80篇 |
1988年 | 55篇 |
1987年 | 63篇 |
1986年 | 47篇 |
1985年 | 58篇 |
1984年 | 57篇 |
1983年 | 42篇 |
1982年 | 39篇 |
1981年 | 33篇 |
1980年 | 28篇 |
1979年 | 17篇 |
1978年 | 22篇 |
1977年 | 14篇 |
1976年 | 15篇 |
1975年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
B D Wilson V M Mondloch A L Katzenstein V L Moore 《The Journal of allergy and clinical immunology》1984,74(2):180-184
Immunized rabbits that were aerosol challenged for 2 to 3 wk with pigeon dropping extract, an etiologic agent of hypersensitivity pneumonitis, developed chronic pulmonary inflammation associated with cell-mediated immunity in bronchoalveolar cells. However, prolonged aerosol challenge for 12 wk resulted in the diminution of pulmonary inflammation (modulation) and the loss of demonstrable cell-mediated immunity. This was probably not due to loss of sensitized lymphocytes that mediated pulmonary inflammation. Furthermore, rabbits undergoing modulation when they were challenged with an unrelated antigen were refractory to the development of pulmonary inflammation for at least 9 wk. After this refractory period, animals reimmunized and aerosol challenged with pigeon dropping extract displayed an anamnestic response and produced pulmonary lesions that were strikingly similar to the histopathology of human hypersensitivity pneumonitis. 相似文献
122.
Responses of lateral medullary neurons to microstimulation of two points in the locomotor strip—rostral and caudal to the obex—were recorded intracellularly in mesencephalic decerebellated uncurarized cats. Excitatory and inhibitory postsynaptic potentials and orthodromic action potentials occurred up to 20 ms after a single stimulus. A number of cells responded to stimulation of a locomotor point by a repetitive discharge, and in some cells synaptic responses were evoked by contralateral stimulation. The responsive neurons were scattered among other cells in the lateral medullary tegmentum. At least one-third of neurons with synaptic responses to stimulation of the rostral locomotor point were antidromically invaded from the caudal one. The characteristic length of these descending axons was between 4 and 9 mm, although there were longer axons too.The lateral medullary cells which give synaptic responses to stimulation of the locomotor strip form the locomotor column located medial to the strip, and a portion of these cells send their axons to the strip. It is suggested that the activity is propagated polysynaptically along the column through axonal collaterals of its neurons. One can assume that when repetitive stimulation achieves a threshold for locomotion such a propagation occurs without decrement. As a result, spinal stepping generators are activated. 相似文献
123.
Zheng-Lin Jiang Hisao Yamaguchi Akira Takahashi Shingo Tanabe Noboru Utsuyama Toshitaka Ikehara Keiko Hosokawa Hiroyuki Tanaka Yohsuke Kinouchi Hiroshi Miyamoto 《European journal of applied physiology》1995,70(3):234-239
Cerebral blood volume flow and flow velocity have been reported to increase during dynamic exercise, but whether the two increase in parallel and whether both increases occur as functions of exercise intensity remain unsettled. In this study, blood flow velocity in the common carotid artery was measured using the Doppler ultrasound method in eight healthy male students during graded treadmill exercise. The exercise consisted of stepwise progressive increases and decreases in exercise intensity. The peak intensity corresponded to approximately 85% of maximal oxygen consumption. During this exercise, the heart rate (f
c), mean blood pressure (BP) in the brachial artery and mean blood flow velocity (cc) in the common carotid artery increased as functions of exercise intensity. At the peak exercise intensity, (f
c), BP and cc increased by 134.5%, 20.5% and 51.8% over the control levels before exercise (P < 0.01), respectively. The resistance index (RI) and pulsatility index (PI) were determined from the velocity profile and were expected to reflect the distal cerebral blood flow resistance. The RI and PI increased during the graded exercise, but tended to decrease at the highest levels of exercise intensity. As cc increased with increases in exercise intensity it would be expected that cerebral blood flow would also increase at these higher intensities. It is also suggested that blood flow velocity in the cerebral artery does not proportionately reflect the cerebral blood flow during dynamic exercise, since the cerebral blood flow resistance changes. 相似文献
124.
125.
126.
127.
Alyce C. Russell Agnieszka Kepka Irena Trbojević-Akmačić Ivo Ugrina Manshu Song Jennie Hui Michael Hunter Simon M. Laws Gordan Lauc Wei Wang 《Immunobiology》2019,224(1):110-115
Background
Increased body fat may be associated with an increased risk of developing an underlying pro-inflammatory state, thus leading to greater risk of developing certain chronic conditions. Immunoglobulin G has the ability to exert both anti- and pro-inflammatory effects, and the N-glycosylation of the fragment crystallisable portion is involved in mediating this process. Body mass index, a rudimentary yet gold standard indication for body fat, has been shown to be associated with agalactosylated immunoglobulin G N-glycans.Aim
We aimed to determine the association between increased body fat and the immunoglobulin G glycosylation features, comparing body mass index to other measures of body fat distribution.Methods
We investigated a sample of 637 community-based 45–69?year olds, with mixed phenotypes, residing in Busselton, Western Australia. Body mass index and the waist-to-hip and waist-to-height ratios were calculated using anthropometry, while dual-energy x-ray absorptiometry was performed to gain an accurate measure of total and area specific body fat. Serum immunoglobulin GN-glycans were analysed by ultra-performance liquid chromatography.Results
Twenty-two N-glycan peaks were found to be associated with at least one of the fat measures. While the previous association of body mass index to agalactosylated immunoglobulin G was replicated, measures of central adiposity explained the most variation in the immunoglobulin G glycome.Conclusion
Central adiposity is associated with an increased pro-inflammatory fraction of immunoglobulin G, suggesting that the android/gynoid ratio or waist-to-height ratio instead be considered when controlling for adiposity in immunoglobulin G glycome biomarker studies. 相似文献128.
Anti-MOG autoantibodies in Italian multiple sclerosis patients: specificity, sensitivity and clinical association 总被引:2,自引:0,他引:2
Mantegazza R Cristaldini P Bernasconi P Baggi F Pedotti R Piccini I Mascoli N La Mantia L Antozzi C Simoncini O Cornelio F Milanese C 《International immunology》2004,16(4):559-565
There is considerable evidence that multiple sclerosis (MS) is an immune-mediated disease characterized by infiltration of inflammatory cells into the CNS and demyelination. Several myelin proteins may be encephalitogenic, including myelin basic protein, proteolipid protein and myelin oligodendrocyte glycoprotein (MOG), the latter being expressed on the external layer of myelin sheaths and hence accessible to antibody attack. We investigated MOG autoreactivity in serum and cerebrospinal fluid (CSF) by ELISA, employing the recombinant extracellular domain of MOG as antigen. We tested serum samples from 262 MS patients (175 relapsing-remitting, 43 primary progressive and 44 secondary progressive), 131 patients with other neurological diseases (OND) and 307 healthy controls. No patients or controls were receiving immunomodulating treatments. We found anti-MOG antibodies in the serum of 13.7% MS patients, mainly in those with secondary progressive MS (25%), in 13.7% of OND patients and in 6.2% of controls. We found a direct correlation (R(2) = 0.6, P = 0.002) between disease severity and anti-MOG titer only in patients with primary and secondary progressive MS. Anti-MOG antibodies were present in the CSF of 11.4% MS patients and 18.9% OND patients. Intrathecal synthesis of anti-MOG antibodies was demonstrated in four (4.5%) of MS patients and no OND patients. Anti-MOG antibodies are not specific for MS; however, they may characterize a subset of MS patients and this may be revealed by serial assays in relation to changing disease phase. 相似文献
129.
Yu. A. Romanov T. N. Ivchenko Z. F. Sultanova 《Bulletin of experimental biology and medicine》1988,105(3):408-411
Department of Biology, Medico-Biological Faculty, N. I. Pirogov Second Moscow Medical Institute. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 105, No. 3, pp. 345–347, March, 1988. 相似文献
130.
At the age of 3 weeks, C57BL mice have comparatively low proliferative activity of their hepatocytes when the liver grows normally, but also during regeneration of the liver 44 h after its extensive resection (mitotic index 16%). Animals of the same age but of other strains (noninbred, CBA, and CC57BR), however, in most cases have a higher mitotic index of their hepatocytes both under normal conditions and during regeneration of the liver (42, 70, and 60%). This pattern of interlinear differences in mitotic activity of the hepatocytes during growth and regeneration of the liver was still found 7 days after the beginning of the experiment. The results indicate genetic determination of the level of proliferative activity of cells.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR. (Presented by Academician of the Academy of Medical Sciences of the USSR, A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 4, pp. 475–477, April, 1976. 相似文献