全文获取类型
收费全文 | 19465篇 |
免费 | 1848篇 |
国内免费 | 882篇 |
专业分类
耳鼻咽喉 | 261篇 |
儿科学 | 240篇 |
妇产科学 | 207篇 |
基础医学 | 2000篇 |
口腔科学 | 335篇 |
临床医学 | 2545篇 |
内科学 | 2228篇 |
皮肤病学 | 426篇 |
神经病学 | 861篇 |
特种医学 | 668篇 |
外国民族医学 | 9篇 |
外科学 | 1135篇 |
综合类 | 3753篇 |
现状与发展 | 3篇 |
一般理论 | 2篇 |
预防医学 | 1960篇 |
眼科学 | 539篇 |
药学 | 2411篇 |
45篇 | |
中国医学 | 1291篇 |
肿瘤学 | 1276篇 |
出版年
2024年 | 39篇 |
2023年 | 256篇 |
2022年 | 990篇 |
2021年 | 1338篇 |
2020年 | 1018篇 |
2019年 | 651篇 |
2018年 | 715篇 |
2017年 | 811篇 |
2016年 | 651篇 |
2015年 | 1108篇 |
2014年 | 1374篇 |
2013年 | 1360篇 |
2012年 | 2029篇 |
2011年 | 2042篇 |
2010年 | 1365篇 |
2009年 | 1104篇 |
2008年 | 1179篇 |
2007年 | 989篇 |
2006年 | 777篇 |
2005年 | 660篇 |
2004年 | 416篇 |
2003年 | 320篇 |
2002年 | 192篇 |
2001年 | 156篇 |
2000年 | 141篇 |
1999年 | 102篇 |
1998年 | 46篇 |
1997年 | 44篇 |
1996年 | 25篇 |
1995年 | 34篇 |
1994年 | 24篇 |
1993年 | 14篇 |
1992年 | 35篇 |
1991年 | 40篇 |
1990年 | 19篇 |
1989年 | 18篇 |
1988年 | 13篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 12篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1971年 | 6篇 |
1970年 | 4篇 |
1969年 | 4篇 |
1968年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 25 毫秒
11.
In this paper, we propose a new approach aimed at handling the temporal Brainstem Auditory Evoked Potentials (BAEPs) non-stationarity. It is pointed out that for some endocochlear pathologies, BAEPs could be randomly delayed from one response to another. This non-stationarity leads to smoothed BAEPs when applying ensemble averaging or any other technique based on BAEPs stationarity. In that case, waves identification is very difficult, sometimes impossible. The problem consists in estimating time delays. Knowing the distribution of delays allows subsequent study of the dynamic of the cochlea and, perhaps, identification of the nature of its pathology. The approach suggested in this paper is based on Simulated Annealing, used to minimize a non-linear criterion involving delays. This technique is advantageously compared to the non-corrected ensemble averaging method, using a set of simulated data based on a realistic model. As an illustration, results based on real signals recorded from two patients are presented and discussed at the end of the paper. 相似文献
12.
Scrotal leiomyomas with atypical bizarre nuclei are rare, which might be misdiagnosed as malignant tumor. We describe a case of scrotal bizarre leiomyoma in a 65-yr-old man. The tumor was a 1 cm-sized, well circumscribed, oval mass arising from the tunica dartos muscle. Histologically, it was formed by whorling bundles of fusiform cells with occasional atypical, pleomorphic nuclei and pseudo-inclusions. Mitosis was not found. Although morphologically atypical, scrotal bizarre leiomyomas take on a biologic behavior not different from that of conventional leiomyoma, they should be distinguished from leiomyosarcoma to avoid unnecessary treatment. 相似文献
13.
Tamaru N Hishikawa Y Ejima K Nagasue N Inoue S Muramatsu M Hayashi T Koji T 《Laboratory investigation; a journal of technical methods and pathology》2004,84(11):1460-1471
Although estrogen is known to play a crucial role in the pathogenesis of breast cancer, the molecular mechanisms underlying the action of estrogen remain elusive. In the present study, we focused on keratinocyte growth factor (KGF) and its receptor (KGFR) in the pathogenesis of breast cancer, as a growth factor mediating estrogen action, since significant roles of KGF were demonstrated in various steroid hormone-dependent tissues. First, using paraffin-embedded specimens from 42 breast cancer patients, we examined expression patterns of KGF and KGFR by both immunohistochemistry using newly generated antibodies and nonradioactive in situ hybridization with T-T dimerized synthetic oligonucleotide probes. We next compared the results with the expression of estrogen receptor (ER) alpha and beta, proliferative activity and apoptotic frequency (TUNEL staining). Also, the similar approaches were taken to analyze the expression and role of KGF in ER-positive (MCF7, ZR-75-1) and ER-negative (SK-BR-3, MDA-MB-231) human breast cancer cell lines in vitro. In the surgical specimens, KGF was expressed in cancer cells as well as stromal cells in 19/42 cases (45%), while KGFR was found in cancer cells in 24/42 cases (57%). The distribution of protein and mRNA in the analysis of both KGF and KGFR expression generally coincided. Moreover, KGF expression was closely associated with the expression of ER alpha, and the coexpression of KGF and KGFR significantly correlated with lower TUNEL index, but not with proliferative activity. In accordance with the in vivo findings, KGF expression was detected only in ER alpha-positive MCF7 and ZR-75-1 cells in vitro. And more importantly, we found the inhibitory effect of KGF upon the induction of apoptosis by anticancer drugs in MCF7 cells. Collectively, our results indicate that ER alpha may be involved in KGF expression, and that KGF may play antiapoptotic roles, rather than mitogenic, in human breast cancer. 相似文献
14.
Early rehabilitation program in postmastectomy patients: a prospective clinical trial 总被引:2,自引:0,他引:2
The purpose of this study was to determine whether 20 patients who received an early postmastectomy rehabilitation treatment program showed more improvement in range of shoulder motion and functional activities than 13 patients who received instruction for exercise only. Data were obtained at preoperatively, three days after operation, at discharge and at postdischarge one month for each patient on parameters such as range of motion of the ipsilateral shoulder joint, upper extremity circumferential measurements, as well as 10 elements of shoulder function. Postoperatively, both groups showed an increased range of motion of the shoulder joint and improved functional activities, but the group that received postoperative rehabilitation management had a better range of shoulder motion and less difficulty in five items for functional assessment. This study also showed that an early rehabilitation program did not increase postoperative complications. We concluded that an early rehabilitation program or intensive instruction program only by a well-trained physical therapist or physiatrist was beneficial to postmastectomy patients in regaining the function and range of shoulder motion, and significantly better in a rehabilitation group. 相似文献
15.
Li N Nakamura K Jiang Y Tsurui H Matsuoka S Abe M Ohtsuji M Nishimura H Kato K Kawai T Atsumi T Koike T Shirai T Ueno H Hirose S 《Human molecular genetics》2004,13(2):171-179
Systemic lupus erythematosus (SLE), a complex multigenic disease, is a typical antibody-mediated autoimmune disease characterized by production of autoantibodies against a variety of autoantigens and immune complex-type tissue inflammation, most prominently in the kidney. Evidence suggests that genetic factors predisposing to aberrant proliferation/maturation of self-reactive B cells initiate and propagate the disease. In SLE-prone New Zealand Black (NZB) mice and their F1 cross with New Zealand White (NZW) mice, B cell abnormalities can be ascribed mainly to self-reactive CD5+ B1 cells. Our genome-wide scans to search for susceptibility genes for aberrant activation of B1 cells in these mice showed evidence that the gene, Ltk, encoding leukocyte tyrosine kinase (LTK), is a possible candidate. LTK is a receptor-type protein tyrosine kinase, belonging to the insulin receptor superfamily, and is mainly expressed in B lymphocyte precursors and neuronal tissues. Sequence and functional analyses of the gene revealed that NZB has a gain-of-function polymorphism in the LTK kinase domain near YXXM, a binding motif of the p85 subunit of phosphatidylinositol 3-kinase (PI3K). SLE patients also had this type of Ltk polymorphism with a significantly higher frequency compared with the healthy controls. Our findings suggest that these polymorphic LTKs cause up-regulation of the PI3K pathway and possibly form one genetic component of susceptibility to abnormal proliferation of self-reactive B cells in SLE. 相似文献
16.
Lee YS Kim KS Chung YS Cheon DS Jung SK Park KS Na BK Jee YM Kim DS Yoon JD Song CY Lee KH 《Archives of virology》2002,147(9):1711-1720
Summary. We have evaluated PCR–RFLP as a practical method for rapid typing of enteroviruses causing aseptic meningitis in Korea. Through
blind examination of 80 clinical isolates from patients with aseptic meningitis, we have compared the results of conventional
serotyping with PCR–RFLP based genotyping, which was developed for this study. Among the 80 case isolates, which had been
previously typed by routine neutralization test, only 42 cases (52.5%) were matched with typing by PCR–RFLP. The result clearly
demonstrated that the enterovirus serotype does not coincide with the genotype. Therefore, the classification of enteroviruses
by genotyping with PCR–RFLP, although rapid and simple, may be complicated by regional or seasonal differences. However, the
PCR–RFLP method developed in this study is applicable to the epidemiological study of enteroviruses when regional or seasonal
differences exist, and is useful in identifying the source of an infection.
Received August 6, 2001; accepted April 15, 2002 Published online July 10, 2002 相似文献
17.
Xin-Ran Liu Na Zhu Yun-Tao Hao Xiao-Chen Yu Zhen Li Rui-Xue Mao Rui Liu Jia-Wei Kang Jia-Ni Hu Yong Li 《Nutrients》2021,13(3)
Radiation therapy is widely used in the treatment of tumor diseases, but it can also cause serious damage to the body, so it is necessary to find effective nutritional supplements. The main purpose of this study is to evaluate the protective effect of whey hydrolysate peptides (WHPs) against 60Coγ radiation damage in mice and explore the mechanism. BALB/c mice were given WHPs by oral gavage administration for 14 days. Then, some mice underwent a 30-day survival test after 8 Gy radiation, and other mice received 3.5 Gy radiation to analyze the changes in body weight, hematology and bone marrow DNA after three and 14 days. In addition, through further analysis of the level of oxidative stress and intestinal barrier function, the possible mechanism of the radioprotective effect of WHPs was explored. The study found WHPs can prolong survival time, restore body weight, and increase the number of peripheral blood white blood cells and bone marrow DNA content in irradiated mice. In addition, WHPs can significantly improve the antioxidant capacity, inhibit pro-inflammatory cytokines and protect the intestinal barrier. These results indicate that WHPs have a certain radioprotective effect in mice, and the main mechanism is related to reducing oxidative damage. 相似文献
18.
19.
在传统中医经络理论的基础上,结合先进的电子技术设备,设计了一种小型中医经络检测仪。此检测仪通过采集人体穴位经电流测试(给一定电流刺激)所反射出来的信息,经微控制器处理后,能够精确显示或打印出人体的健康状况。检测仪具有方便、快捷等优势,易推广普及。 相似文献
20.
Ipsilesional neglect: behavioural and anatomical features 总被引:2,自引:0,他引:2
M Kim D Na G Kim J Adair K Lee K Heilman 《Journal of neurology, neurosurgery, and psychiatry》1999,67(1):35-38
OBJECTIVE: To learn more about the behavioural and anatomical features of ipsilesional neglect. METHODS: Thirty consecutive patients with spatial neglect were tested on cancellation and line bisection tasks. To learn if patients with ipsilesional neglect demonstrate the sensory-attentional or motor-intentional type of neglect, a video apparatus was used that dissociates these determinants. RESULTS: Five patients showed evidence of ipsilesional neglect. This phenomenon was seen only on the line bisection task. All patients with ipsilesional neglect had lesions involving frontal-subcortical regions. Although ipsilesional neglect evolved from early in three of five cases, the other patients displayed ipsilesional neglect without initial contralateral neglect, suggesting that ipsilesional neglect cannot be fully attributed to a compensatory strategy. The results of the tests that used the video apparatus indicate that right sided frontal or subcortical injury may induce contralateral attentional or intentional "approach" behaviours. CONCLUSIONS: Ipsilesional neglect is most often associated with frontal-subcortical lesions, cannot be entirely attributed to a compensatory strategy, and may be induced by an attentional bias, an intentional bias, or both. 相似文献