全文获取类型
收费全文 | 9418篇 |
免费 | 471篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 67篇 |
儿科学 | 132篇 |
妇产科学 | 263篇 |
基础医学 | 1347篇 |
口腔科学 | 234篇 |
临床医学 | 624篇 |
内科学 | 2053篇 |
皮肤病学 | 276篇 |
神经病学 | 761篇 |
特种医学 | 551篇 |
外科学 | 1581篇 |
综合类 | 27篇 |
一般理论 | 1篇 |
预防医学 | 265篇 |
眼科学 | 150篇 |
药学 | 604篇 |
中国医学 | 15篇 |
肿瘤学 | 965篇 |
出版年
2022年 | 88篇 |
2021年 | 167篇 |
2020年 | 102篇 |
2019年 | 124篇 |
2018年 | 147篇 |
2017年 | 118篇 |
2016年 | 124篇 |
2015年 | 159篇 |
2014年 | 222篇 |
2013年 | 277篇 |
2012年 | 439篇 |
2011年 | 440篇 |
2010年 | 235篇 |
2009年 | 204篇 |
2008年 | 428篇 |
2007年 | 437篇 |
2006年 | 426篇 |
2005年 | 435篇 |
2004年 | 400篇 |
2003年 | 422篇 |
2002年 | 425篇 |
2001年 | 333篇 |
2000年 | 388篇 |
1999年 | 264篇 |
1998年 | 90篇 |
1997年 | 77篇 |
1996年 | 82篇 |
1995年 | 72篇 |
1994年 | 76篇 |
1993年 | 54篇 |
1992年 | 222篇 |
1991年 | 226篇 |
1990年 | 199篇 |
1989年 | 241篇 |
1988年 | 204篇 |
1987年 | 207篇 |
1986年 | 181篇 |
1985年 | 148篇 |
1984年 | 96篇 |
1983年 | 78篇 |
1982年 | 46篇 |
1979年 | 75篇 |
1978年 | 68篇 |
1977年 | 48篇 |
1975年 | 48篇 |
1974年 | 51篇 |
1972年 | 58篇 |
1971年 | 55篇 |
1969年 | 45篇 |
1968年 | 49篇 |
排序方式: 共有9916条查询结果,搜索用时 15 毫秒
11.
12.
13.
Kentaro Matsubara Yasuhiro Fujimoto Hideya Kamei Kohei Ogawa Mureo Kasahara Mikiko Ueda Hiroto Egawa Yasutsugu Takada Masaki Kitajama Koichi Tanaka 《Liver transplantation》2005,11(11):1444-1447
Living-donor liver transplantation (LDLT) has become an established technique to treat children with end-stage liver disease. Biliary atresia (BA), one of the most common indications for liver transplantation in children, can be associated with situs inversus (SI). In the past, the presence of SI has been considered to be an absolute contraindication for liver transplantation because of the technical difficulties. Recently, some reports of successful diseased-donor liver transplantation in patients with BA complicated by SI have been published; however, few reports of that with LDLT exist. The technical difficulties involved with LDLT for such cases have not been described. Herein, we present 4 successful cases of LDLT for BA with SI. Complex anomalies associated with SI, such as a hepatic artery arising from the supraceliac aorta, a preduodenal portal vein, and absence of the retrohepatic inferior vena cava, increase the technical difficulties involved with the operation. Additional caution is required in LDLT because a living-donor graft has short vessels and the availability of vascular grafts from the donor is limited. In conclusion, LDLT for BA complicated by SI can be managed successfully with technical modifications and scrupulous attention. This series represents the largest reported group of patients with BA complicated by SI who underwent a successful LDLT procedure. 相似文献
14.
Inhibition of PAF-induced eosinophil accumulation in pulmonary airways of guinea pigs by anti-asthma drugs 总被引:3,自引:0,他引:3
S Sanjar S Aoki K Boubekeur L Burrows I Colditz I Chapman J Morley 《Japanese journal of pharmacology》1989,51(2):167-172
Intraperitoneal (i.p.) injection of platelet activating factor (PAF) in guinea pigs caused a dose-related increase in the number of eosinophils recovered from bronchoalveolar lavage fluid (BALF). The prevalence of eosinophils in BALF had significantly increased within 1 hr of i.p. injection of PAF (10 micrograms/animal) and was maximal after 24 hr. Subcutaneous osmotic mini-pumps were used to administer drugs for 5 days prior to i.p. injection of PAF (10 micrograms/animal) and for the subsequent 24 hr. The percentage increase of eosinophils in BALF, due to PAF, was inhibited in animals treated with dexamethasone, aminophylline, cromoglycate, tranilast or ketotifen, but not in animals treated with oxatomide, azelastine, amlexanox, ibudilast or AA-861. These results suggest that inhibition of pulmonary eosinophilia may be a necessary property of prophylactic anti-asthma drugs and provide indirect evidence favoring a role for PAF in eosinophilia of asthma. 相似文献
15.
The precise course and termination levels of the corticospinal tract (CST) in the cat were studied using the anterograde transport of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP). Following injection of WGA-HRP into the pericruciate (sensorimotor) cortex on one side, we observed the precise caudal termination levels of the CST fibers in the lateral and ventral funiculi. Simultaneously, the bilateral CSTs descending through the dorsal funiculus of the spinal cord were identified. Anterogradely labeled CST fibers within the lateral and ventral funiculi were observed bilaterally to reach the level of the third sacral (S3) spinal segment, which is lower than that ever described. The lowest level of the CST fibers within the dorsal funiculus, however, reached the level of the first sacral (S1) spinal segment. In conclusion, this study demonstrates that, in the cat, there exist 6 different CSTs (crossed and uncrossed lateral, ventral, dorsal) and that the termination levels of the lateral and ventral CSTs are much lower than those described in previous reports. 相似文献
16.
Pharmacological studies suggest that beta-adrenergic receptors (beta AR) in the medial nuclei of the solitary tracts (m-NTS) facilitate presynaptic release of catecholamines and also function at postsynaptic sites. We have localized the antigenic sites for a monoclonal antibody against a peptide corresponding to amino acids 226-239 of beta AR in the m-NTS of rat brain. By light microscopy, immunoperoxidase labeling for this antibody was detected in somata and proximal processes of many small cells that were distributed throughout the rostrocaudal extent of the m-NTS. Electron microscopy confirmed the cytoplasmic localization of beta AR in perikarya and proximal dendrites of neurons. Immunoreactivity occurred as discrete patches associated with cytoplasmic surfaces of plasma membrane and with irregularly-shaped saccules with clear lumen in the immediate vicinity. Select regions of nuclear envelopes, mitochondrial membranes, and rough endoplasmic reticulum were also immunoreactive along their cytoplasmic surfaces. In contrast, the Golgi apparatus was labeled, but infrequently. Immunoreactivity was also detected at numerous post- and occasional presynaptic membrane specializations of select axodendritic junctions. Dual labeling for the beta AR-antibody by the immunoperoxidase method and for a rabbit antiserum against the catecholamine-synthesizing enzyme, tyrosine hydroxylase (TH), by the immunoautoradiographic method within the same sections, further established the precise cellular relations between beta AR and catecholaminergic neurons. Immunoreactivity for beta AR was detected in numerous perikarya and proximal dendrites that did not show detectable levels of TH. However, a few cells were dually labeled for both antigens, as seen by both light and electron microscopy. The TH-labeled terminals formed synapses at junctions both with and without beta AR-like immunoreactivity. These results from the single and dual labeling studies: (1) confirm biochemical predictions that amino acids 226-239 of beta AR protein reside intracellularly; (2) provide the first ultrastructural evidence for beta AR localization within both pre- and postsynaptic membrane specializations of a subset of catecholaminergic synapses; and (3) suggest select intracellular sites that may be involved with synthesis and/or internalization and degradation of the receptor protein. 相似文献
17.
Peristaltic reflex and peptidergic nerve control in megacolon 总被引:1,自引:0,他引:1
N Aoki R Tomita N Nagai K Munekata Y Kurose K Morita 《Nippon Heikatsukin Gakkai zasshi》1989,25(5):233-235
18.
The purpose of the present study was to examine the effect of non-enzymatic glycosylation and subsequent heating on the browning of the plantar stratum corneum and the finger-nail, and to elucidate the pathogenesis of the yellow skin and the yellow nail seen in diabetic subjects. We incubated stratum corneum and nail from non-diabetics in 0 (control), 10 (only nail), 20 (only nail), 100 and 250 mM glucose buffer at 37 degrees C for 5 days. These glycosylated samples were dialysed against distilled water for 96 h. Distilled water was changed every 24 h. Then samples were dried for 24 h. The extent of non-enzymatic glycosylation was measured by furosine content. Each 5 mg of sample was hydrolysed by 6 N HCl and processed for measurement of furosine by high-performance liquid chromatography. The rest of each sample was stored at 37, 42 (only nail), 47 and 52 degrees C for 14 days. Browning of the stratum corneum was assessed macroscopically, and that of the nail by spectrophotometry. Based on their spectrophotometric reflectances. Munsell's scores (H = hue score, V = lightness score, C = saturation score) and (H + C)/V were calculated for objective evaluation of browning. Incubation of the stratum corneum and nail with glucose buffer increased their non-enzymatic glycosylation (furosine) dose dependently. Macroscopically, the browning of the stratum corneum was enhanced in proportion to the glucose concentration and storage temperature. However, samples incubated in 10 and 20 mM glucose and stored at 42 degrees C did not show visible browning. Munsell's score of the nail samples treated by glycosylation and heating showed increased hue and saturation but reduced lightness. (H + C)/V values of these nail samples were significantly higher than those of the control. We could not detect any fluorescence with Wood light in the browned samples. The present in vitro study demonstrated that the browning of the stratum corneum and the nail depended on the extent of both non-enzymatic glycosylation and storage temperature. We suggested a hypothesis that the non-enzymatic glycosylation and the storage temperature of the stratum corneum and the nail might be a contributory factor in the development of yellow skin and yellow nail in diabetic patients. 相似文献
19.
[3H]Flunitrazepam (FNZ) binding sites were characterized in homogenates of cat visual cortex during normal postnatal development and following dark rearing from birth. In parallel experiments, the distribution and density of [3H]FNZ binding sites were examined by in vitro autoradiographic or 'scrape' methods. In homogenates, Bmax measurements showed low early values, rising to a peak in receptor density at about 60 days postnatal, followed by a decline in adulthood. At all ages, gamma-aminobutyric acid (GABA) altered the Kd, but not the Bmax of [3H]FNZ binding sites. Kd values showed a general increase with age, parallelled by an increased sensitivity to GABA. Receptor autoradiography revealed that the highest density of [3H]FNZ binding sites was in layer IV of cats of all ages. Deafferentation of extrinsic inputs to the visual cortex by surgical undercutting did not alter this pattern of laminar distribution, indicating that the receptors were associated with intrinsic cortical elements rather than subcortical inputs. Dark rearing had no effect on [3H]FNZ laminar distribution in the visual cortex. The Bmax was higher at 30 days postnatal, but did not differ significantly thereafter. Modulation by GABA was concomitantly higher at 30 days, but lower than normal in dark-reared animals at ages greater than 30 days postnatal. The results are discussed in relation to the normal and abnormal development of GABA receptors in the cat visual cortex. 相似文献
20.