全文获取类型
收费全文 | 9325篇 |
免费 | 481篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 150篇 |
儿科学 | 106篇 |
妇产科学 | 90篇 |
基础医学 | 994篇 |
口腔科学 | 266篇 |
临床医学 | 739篇 |
内科学 | 2503篇 |
皮肤病学 | 139篇 |
神经病学 | 772篇 |
特种医学 | 393篇 |
外科学 | 1503篇 |
综合类 | 42篇 |
一般理论 | 1篇 |
预防医学 | 294篇 |
眼科学 | 194篇 |
药学 | 547篇 |
中国医学 | 33篇 |
肿瘤学 | 1118篇 |
出版年
2023年 | 82篇 |
2022年 | 161篇 |
2021年 | 314篇 |
2020年 | 163篇 |
2019年 | 208篇 |
2018年 | 242篇 |
2017年 | 156篇 |
2016年 | 199篇 |
2015年 | 212篇 |
2014年 | 293篇 |
2013年 | 316篇 |
2012年 | 515篇 |
2011年 | 617篇 |
2010年 | 338篇 |
2009年 | 267篇 |
2008年 | 479篇 |
2007年 | 583篇 |
2006年 | 554篇 |
2005年 | 608篇 |
2004年 | 597篇 |
2003年 | 561篇 |
2002年 | 495篇 |
2001年 | 156篇 |
2000年 | 183篇 |
1999年 | 136篇 |
1998年 | 110篇 |
1997年 | 83篇 |
1996年 | 103篇 |
1995年 | 58篇 |
1994年 | 50篇 |
1993年 | 56篇 |
1992年 | 85篇 |
1991年 | 77篇 |
1990年 | 87篇 |
1989年 | 86篇 |
1988年 | 62篇 |
1987年 | 76篇 |
1986年 | 53篇 |
1985年 | 47篇 |
1984年 | 46篇 |
1983年 | 31篇 |
1982年 | 19篇 |
1980年 | 24篇 |
1979年 | 29篇 |
1976年 | 21篇 |
1974年 | 23篇 |
1972年 | 26篇 |
1969年 | 18篇 |
1968年 | 24篇 |
1967年 | 19篇 |
排序方式: 共有9884条查询结果,搜索用时 15 毫秒
11.
Brain N-acetylaspartate is elevated in Pelizaeus-Merzbacher disease with PLP1 duplication. 总被引:1,自引:0,他引:1
J Takanashi K Inoue M Tomita A Kurihara F Morita H Ikehira S Tanada E Yoshitome Y Kohno 《Neurology》2002,58(2):237-241
OBJECTIVE: To assess alterations in brain metabolites of patients with Pelizaeus-Merzbacher disease (PMD) with the proteolipid protein gene 1 (PLP1) duplications using quantitative proton MRS. METHODS: Five unrelated male Japanese patients with PMD with PLP1 duplications were analyzed using automated proton brain examination with the point resolved spectroscopy technique (repetition and echo time of 5,000 and 30 msec). Localized spectra in the posterior portion of the centrum semiovale were acquired, and absolute metabolite concentrations were calculated using the LCModel. RESULTS: Absolute concentrations of N-acetylaspartate (NAA), creatine (Cr), and myoinositol (MI) were increased by 16% (p < 0.01), 43% (p < 0.001), and 31% (p < 0.01) in patients with PMD as compared with age-matched controls. There was no statistical difference in choline concentration. CONCLUSION: The increased concentration of NAA, which could not be detected by previous relative quantitation methods, suggests two possibilities: axonal involvement secondary to dysmyelination, or increased cell population of oligodendrocyte progenitors. Elevated Cr and MI concentrations may reflect the reactive astrocytic gliosis. Our study thus emphasizes the importance of absolute quantitation of metabolites to investigate the disease mechanism of the dysmyelinating disorders of the CNS. 相似文献
12.
13.
Tetsuya Nomura Tatsuya Kawasaki Takuji Tanabe Akihiro Azuma Hiroaki Matsubara 《Annals of thoracic and cardiovascular surgery》2007,13(2):118-121
Mediastinal cystic tumors are well-marginated round lesions that comprise 12% to 18% of all mediastinal masses. These lesions include a variety of diseases with overlapping radiologic appearances and variable prognoses. Pathological examinations are almost always required for differential diagnosis. We encountered a case of anterior mediastinal tumor discovered in the process of investigation of Raynaud's phenomenon. Taking into account the tumor location, a pericardial cyst was initially suspected. However, the tumor was surgically resected and histopathological examinations demonstrated thymus-like tissue in the cyst walls. Raynaud's phenomenon greatly improved after surgery. These findings suggested that cystic thymoma originated from ectopic thymic tissue and is accompanied by paraneoplastic syndrome. 相似文献
14.
Noriyoshi Kurihara Hua Zhou Sakamuri V Reddy Veronica Garcia Palacios Mark A Subler David W Dempster Jolene J Windle G David Roodman 《Journal of bone and mineral research》2006,21(3):446-455
We targeted the MVNP gene to the OCL lineage in transgenic mice. These mice developed abnormal OCLs and bone lesions similar to those found in Paget's patients. These results show that persistent expression of MVNP in OCLs can induce pagetic-like bone lesions in vivo. INTRODUCTION: Paget's disease (PD) of bone is the second most common bone disease. Both genetic and viral factors have been implicated in its pathogenesis, but their exact roles in vivo are unclear. We previously reported that transfection of normal human osteoclast (OCL) precursors with the measles virus nucleocapsid (MVNP) or measles virus (MV) infection of bone marrow cells from transgenic mice expressing a MV receptor results in formation of pagetic-like OCLs. MATERIALS AND METHODS: Based on these in vitro studies, we determined if the MVNP gene from either an Edmonston-related strain of MV or a MVNP gene sequence derived from a patient with PD (P-MVNP), when targeted to cells in the OCL lineage of transgenic mice with the TRACP promoter (TRACP/MVNP mice), induced changes in bone similar to those found in PD. RESULTS: Bone marrow culture studies and histomorphometric analysis of bones from these mice showed that their OCLs displayed many of the features of pagetic OCLs and that they developed bone lesions that were similar to those in patients with PD. Furthermore, IL-6 seemed to be required for the development of the pagetic phenotype in OCLs from TRACP/MVNP mice. CONCLUSIONS: These results show that persistent expression of the MVNP gene in cells of the OCL lineage can induce pagetic-like bone lesions in vivo. 相似文献
15.
16.
Tetsushi Tsujimoto Kazushi Daimon Kazuhide Izumi Maki Sawai Tatsuya Iwashige 《Seishin shinkeigaku zasshi》2007,109(4):313-320
Fifty two outpatients, who showed signs of school-refusal-withdrawal at the Shiga Prefectural Psychiatric Institution have been analyzed according to their age, gender, ICD-10 diagnosis, medical evolution, and total number of consultations. A total of 61.5% of the population were male, and they showed a higher average and a wider range of age than female patients. According to the ICD-10 diagnosis, 67.3% were in the group of F40-48 neurotic, stress-related and somatoform disorders, and 11.5% were in the group of F30-39 mood [affective] disorders. Twenty five % of the patients were assumed to have show medical improvement, and 42.3% of the patients continued to have further consultations. This article discusses the possible role of psychiatric medical institutions in supporting cases of school-refusal and social-withdrawal. 相似文献
17.
Daisuke Kubota Takanori Kanai Fumiro Yui Tomoko Matsumoto Takahiro Kawamura Yasuhiro Itsui Eriko Okada Seishin Chin Shinya Ooka Masakazu Nagahori Kiichiro Tsuchiya Akihiro Araki Naoya Sakamoto Tatsuya Miyata Mamoru Watanabe 《Nihon Shokakibyo Gakkai zasshi》2007,104(1):42-46
A 44-year-old women developed marked myopathy one year earlier, when she was treated with intravenous prednisolone for acute severe exacerbation of ulcerative colitis. When she was admitted to our hospital for another severe exacerbation, intravenous cyclosporine A was administered as monotherapy because she could not tolerate corticosteroid. The treatment was successful and she obtained complete remission. Cyclosporine A monotherapy is considered to be a valuable alternative to proctocolectomy for severe ulcerative colitis patients who cannot tolerate corticosteroid. 相似文献
18.
19.
Noriko Yoshimura Tomoko Takijiri Hirofumi Kinoshita Shigeto Danjoh Takahiro Kasamatsu Seiji Morioka Kiyomi Sakata Tsutomu Hashimoto Tatsuya Takeshita 《Osteoporosis international》2004,15(2):139-144
The aim of this study was to clarify and compare the temporal course of bone mineral density (BMD) between fast bone losers and normal residents in Miyama Village, a rural Japanese community. BMD was measured over a 10-year period in a cohort study in Miyama Village, Wakayama Prefecture, Japan, to provide information on rate of bone loss in the mature and elderly population. Subjects (n=400) were selected by sex and age stratum from the full list of residents born in 1910–1949, with 50 men and 50 women in each age decade. Baseline BMD of the lumbar spine and proximal femur was measured using dual energy X-ray absorptiometry in 1990, 1993, 1997 and 2000. In the cohort, 171 men and 189 women completed the follow-up survey performed in 1993. After calculating the rate of bone loss between 1990 and 1993, the greatest tertile from the distribution of bone loss was categorized as fast bone losers, with the remainder considered as normal subjects. Changes in BMD were compared between normal subjects and fast bone losers over the 10-year period. Mean rate of change for BMD at both lumbar spine and femoral neck in fast bone losers recovered to levels similar to those in normal subjects over 7 years of observation. By contrast, BMD at the lumbar spine and femoral neck decreased steeply over the 10-year period in both groups, and mean BMD for fast bone losers was significantly lower than that of normal subjects (P<0.05). These differences were apparent only at the lumbar spine in both men and women, even after adjusting for age. These results indicate that fast bone loss is a transient phenomenon rather than a fixed status, although individuals who have been categorized as fast bone losers at some stage continue to display low BMD in the lumbar spine. 相似文献
20.
Involvement of enzymatic degradation in the inactivation of tachykinin neurotransmitters in neonatal rat spinal cord.
下载免费PDF全文
![点击此处可从《British journal of pharmacology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H Suzuki K Yoshioka M Yanagisawa O Urayama T Kurihara R Hosoki K Saito M Otsuka 《British journal of pharmacology》1994,113(1):310-316
1. The possible involvement of enzymatic degradation in the inactivation of tachykinin neurotransmitters was examined in the spinal cord of the neonatal rat. 2. The magnitude of substance P (SP)- or neurokinin A (NKA)-evoked depolarization of a lumbar ventral root in the isolated spinal cord preparation was increased by a mixture of peptidase inhibitors, consisting of actinonin (6 microM), arphamenine B (6 microM), bestatin (10 microM), captopril (10 microM) and thiorphan (0.3 microM). The mixture augmented the response to NKA more markedly than that to SP. 3. In the isolated spinal cord-cutaneous nerve preparation, the saphenous nerve-evoked slow depolarization of the L3 ventral root was augmented by the mixture of peptidase inhibitors in the presence of naloxone (0.5 microM) but not in the presence of both naloxone and a tachykinin receptor antagonist, GR71251 (5 microM). 4. Application of capsaicin (0.5 microM) for 6 min to the spinal cord evoked an increase in the release of SP from the spinal cord. The amount of SP released was significantly augmented by the mixture of peptidase inhibitors. 5. Synaptic membrane fractions were prepared from neonatal rat spinal cords. These fractions showed degrading activities for SP and NKA and the activities were inhibited by the mixture of peptidase inhibitors. The degrading activity for NKA was higher than that for SP and the inhibitory effect of the mixture for NKA was more marked than that for SP. Although some other fractions obtained from homogenates of spinal cords showed higher degrading activities for SP, these activities were insensitive to the mixture of peptidase inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献