全文获取类型
收费全文 | 14556篇 |
免费 | 625篇 |
国内免费 | 104篇 |
专业分类
耳鼻咽喉 | 190篇 |
儿科学 | 374篇 |
妇产科学 | 134篇 |
基础医学 | 1585篇 |
口腔科学 | 392篇 |
临床医学 | 872篇 |
内科学 | 3510篇 |
皮肤病学 | 252篇 |
神经病学 | 1101篇 |
特种医学 | 574篇 |
外科学 | 2883篇 |
综合类 | 45篇 |
预防医学 | 449篇 |
眼科学 | 294篇 |
药学 | 944篇 |
中国医学 | 34篇 |
肿瘤学 | 1652篇 |
出版年
2023年 | 86篇 |
2022年 | 174篇 |
2021年 | 311篇 |
2020年 | 142篇 |
2019年 | 206篇 |
2018年 | 240篇 |
2017年 | 194篇 |
2016年 | 299篇 |
2015年 | 267篇 |
2014年 | 341篇 |
2013年 | 445篇 |
2012年 | 739篇 |
2011年 | 801篇 |
2010年 | 506篇 |
2009年 | 453篇 |
2008年 | 746篇 |
2007年 | 859篇 |
2006年 | 848篇 |
2005年 | 905篇 |
2004年 | 870篇 |
2003年 | 744篇 |
2002年 | 703篇 |
2001年 | 379篇 |
2000年 | 404篇 |
1999年 | 324篇 |
1998年 | 232篇 |
1997年 | 196篇 |
1996年 | 155篇 |
1995年 | 125篇 |
1994年 | 131篇 |
1993年 | 124篇 |
1992年 | 237篇 |
1991年 | 213篇 |
1990年 | 202篇 |
1989年 | 220篇 |
1988年 | 163篇 |
1987年 | 161篇 |
1986年 | 145篇 |
1985年 | 158篇 |
1984年 | 91篇 |
1983年 | 92篇 |
1982年 | 42篇 |
1980年 | 37篇 |
1979年 | 59篇 |
1978年 | 48篇 |
1977年 | 53篇 |
1974年 | 37篇 |
1972年 | 41篇 |
1970年 | 39篇 |
1968年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Naoki Sugawara Koji Arizono Toshiichi Kitajima Hideaki Inoue Yu-Rong Lai 《Archives of toxicology》1997,71(5):336-339
A new mutant, the Eisai hyperbilirubinemic (EHB) rat, shows no inherent expression of the canalicular isoform of the multidrug
resistance protein (cMrp) in the liver. It has defective biliary secretion of organic anions such as bilirubin glucuronides,
bromosulfophthalein (BSP), cysteinyl leukotrienes, glutathione (GSH) and bile acid sulfate and glucuronides. When rats were
injected intravenously with CdCl2, biliary excretion of Cd over 30 min was 0.28% and 0.004% of the total dose in Sprague-Dawley (SD) and EHB rats, respectively.
Six SD rats and five EHB rats were fed a diet containing Cd. Bile Cd was detected at the level of 2 ng/20 min in SD rats,
but not in EHB rats. There was no significant difference of hepatic Cd concentration between SD and EHB rats. Furthermore,
there were no significant differences of renal and intestinal Cd, and hepatic and renal metallothionein (MT) concentrations
between the SD and EHB groups. Biliary excretion of reduced-GSH for 20 min was 1.3 ± 0.3 mg and 3.6 ± 0.9 μg in SD and EHB
rats, respectively. Our results suggest that hepatobiliary excretion of exogenous Cd is mediated mainly via carrier transport,
including a cMrp or GSH carrier, but that the lack of the transport pathway does not contribute to abnormal accumulation of
Cd in the liver.
Received: 12 August 1996 / Accepted 7 November 1996 相似文献
62.
63.
The integrity of the sensory nervous system in the anal canals of chronically constipated children was investigated using
evoked potential techniques examining cerebral and spinal evoked potentials from the lower extremities and anal canal. Stimulation
of the posterior tibial nerve produced no significant difference in the parameters of spinal and cerebral evoked potentials
between 18 controls and 12 chronically constipated chidren. However, stimulation of the anal canal resulted in evoked potentials
related to the age and/or consciousness level of the control children. Reproducible cerebral responses were obtained only
from nine of these control children, all aged over 4 years, who were examined while awake without sedatives. A typical response
was characterized by a polyphasic wave occurring with an onset latency of 79.4± 27.7ms (mean ±SD). In the 12 chronically constipated
children, the 5 sedated patients examined while asleep did not show any reproducible potential, as in the controls. However,
in the remaining 7 children examined while awake, the occurrence of the anal canal evoked potential was significantly reduced,
and only two exhibited a cerebral response. These findings suggest that rectal mucosal perception of the intraluminal stimuli
might be disturbed in some children with chronic constipation. 相似文献
64.
Recent technological advances, in both hardware and software, and availability of various monoclonal antibodies (MoAb) for membrane antigens of blood cells have expanded the application of flow cytometry (FCM) in medicine. In the haematology laboratory, FCM has been used mainly for assessment of leukemia and lymphoma and for determination of lymphocyte subsets. In acute leukemia, FCM is useful to classify ALL accurately, particularly for bi phenotypic or mixed lineage leukemia. In lymphocyte subset determination, we found that the use of magnetic beads to remove contaminating monocytes and some granulocytes to purify the lymphocyte-population is helpful in clarify the subsets. We present data describing the age dependent variation in lymphocyte subsets in the pediatric population. In early life (up to 2 years old), CD4 (+) 2H4 (+) lymphocyte overwhelmed CD4 (+) 2H4 (-) cells, implying predominance of suppressor-inducer activity. We also presented some cases of markedly increased double negative T cells (gamma/delta TCR) and a rare case of double positive (CD4+, CD8+) T cells. 相似文献
65.
66.
Toshikazu Saito M.D. Hideaki Ishizawa M.D. Fumiaki Tsuchiya M.D. Hiroki Ozawa M.D. Naohiko Takahata M.D. 《Psychiatry and clinical neurosciences》1986,40(2):189-194
Abstract: Monoamine and their acid metabolites were determined in the CSF of 18 drug-treated chronic schizophrenic patients with the symptoms of tardive dyskinesia and neuroleptic-induced Parkinsonism (Parkinsonism). Six healthy volunteers were used as the control group.
The norepinephrine (NE) levels were found to be significantly higher in the patients with tardive dyskinesia than in the controls. Furthermore, elevated CSF NE levels were also observed in the patients with Parkinsonism. Epinephrine (E) and Dopamine (DA) were not present in the CSF of the control group, whereas measurable levels of DA could be detected in 4 out of 9 and E was found in 8 out of 9 patients with tardive dyskinesia. The mean concentration of HVA was slightly but not significantly elevated in the patients with tardive dyskinesia and Parkinsonism. The mean values of CSF 5-HIAA were all within the normal range in both patient groups. From the above results, it was suggested that abnormal adrenergic activity rather than abnormal dopaminergic activity may play an important role as a mechanism in the etiopathogenesis of extrapyramidal disorders. Furthermore, in the patients with Parkinsonism, CSF neurochemical observations were similar to those of the patients with tardive dyskinesia in this study. It may help to explain the clinical coexistence of tardive dyskinesia and neuroleptic-induced Parkinsonism. 相似文献
The norepinephrine (NE) levels were found to be significantly higher in the patients with tardive dyskinesia than in the controls. Furthermore, elevated CSF NE levels were also observed in the patients with Parkinsonism. Epinephrine (E) and Dopamine (DA) were not present in the CSF of the control group, whereas measurable levels of DA could be detected in 4 out of 9 and E was found in 8 out of 9 patients with tardive dyskinesia. The mean concentration of HVA was slightly but not significantly elevated in the patients with tardive dyskinesia and Parkinsonism. The mean values of CSF 5-HIAA were all within the normal range in both patient groups. From the above results, it was suggested that abnormal adrenergic activity rather than abnormal dopaminergic activity may play an important role as a mechanism in the etiopathogenesis of extrapyramidal disorders. Furthermore, in the patients with Parkinsonism, CSF neurochemical observations were similar to those of the patients with tardive dyskinesia in this study. It may help to explain the clinical coexistence of tardive dyskinesia and neuroleptic-induced Parkinsonism. 相似文献
67.
Intraoperative monitoring of anorectal pressure was used in a case of sacral lipomeningocele accompanied by congenital dermal sinus to protect the physiological function of the anorectal sphincters. This monitoring system consists of a manometric anorectal balloon and neural electrical stimulation. The system was able to differentiate functioning neural structures from surrounding tissues during the operation. 相似文献
68.
69.
Acute kindling: interstimulation interval effects and spontaneous interictal or ictal epileptiform discharges 总被引:3,自引:0,他引:3
With regard to "acute kindling" that signifies progressive changes in various epileptiform discharges produced with repeated electrical stimulations in a brief time span in acute experiments, the interstimulation interval effect was examined. Kindling developments produced respectively with 3 and 30-minute interval stimulations to the visual cortex of rabbits were compared with each other. Eventually, in kindling with a longer interstimulation interval, after-discharges induced in every trial of stimulation were often lengthened in duration more prominently than those with the shorter interstimulation interval and, furthermore, occasional slight relapses in the afterdischarge duration occurred more infrequently in the former than in the latter. These results suggest that the interstimulation interval plays an important role in the development of acute kindling, presumably in relation to postictal inhibition. In addition, spontaneous interictal or ictal epileptiform discharges occasionally arising during the 3-minute interstimulation intervals were reported. These spontaneous discharges may suggest a high epileptogenicity in acute kindling. 相似文献
70.
Key words reversal of neuromuscular blockade pancuronium - neostigmine 相似文献