全文获取类型
收费全文 | 36008篇 |
免费 | 1617篇 |
国内免费 | 297篇 |
专业分类
耳鼻咽喉 | 266篇 |
儿科学 | 654篇 |
妇产科学 | 412篇 |
基础医学 | 4779篇 |
口腔科学 | 1003篇 |
临床医学 | 2103篇 |
内科学 | 8957篇 |
皮肤病学 | 855篇 |
神经病学 | 2448篇 |
特种医学 | 1253篇 |
外科学 | 6434篇 |
综合类 | 146篇 |
一般理论 | 1篇 |
预防医学 | 1005篇 |
眼科学 | 630篇 |
药学 | 2079篇 |
中国医学 | 123篇 |
肿瘤学 | 4774篇 |
出版年
2024年 | 25篇 |
2023年 | 202篇 |
2022年 | 537篇 |
2021年 | 879篇 |
2020年 | 450篇 |
2019年 | 648篇 |
2018年 | 845篇 |
2017年 | 655篇 |
2016年 | 774篇 |
2015年 | 800篇 |
2014年 | 1077篇 |
2013年 | 1370篇 |
2012年 | 2228篇 |
2011年 | 2607篇 |
2010年 | 1475篇 |
2009年 | 1213篇 |
2008年 | 2230篇 |
2007年 | 2464篇 |
2006年 | 2303篇 |
2005年 | 2480篇 |
2004年 | 2392篇 |
2003年 | 2394篇 |
2002年 | 2399篇 |
2001年 | 363篇 |
2000年 | 304篇 |
1999年 | 432篇 |
1998年 | 575篇 |
1997年 | 454篇 |
1996年 | 431篇 |
1995年 | 370篇 |
1994年 | 323篇 |
1993年 | 298篇 |
1992年 | 208篇 |
1991年 | 187篇 |
1990年 | 182篇 |
1989年 | 165篇 |
1988年 | 145篇 |
1987年 | 107篇 |
1986年 | 102篇 |
1985年 | 87篇 |
1984年 | 105篇 |
1983年 | 85篇 |
1982年 | 71篇 |
1981年 | 87篇 |
1980年 | 82篇 |
1979年 | 59篇 |
1978年 | 41篇 |
1977年 | 29篇 |
1976年 | 24篇 |
1975年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Takeshi Kondoh Shinichi Miura Masahiro Nakahara Takashi Mizowaki Hirotomo Tanaka Yoshiyuki Takaishi 《Radiology Case Reports》2022,17(4):1076
A 13-year-old boy, with a history of intermittent headache and transient diplopia, was found to have non-hemorrhagic cerebral arteriovenous malformation in the midbrain tegmental region associated with hydrocephalus. Gamma knife radiosurgery was performed at 16 Gy with 75% marginal dose. Posttreatment course was uneventful. Follow-up MR imaging at one year after the treatment revealed complete disappearance of the abnormal vascular flow voids. The size of each ventricle at the treatment and at one year after treatment were as follows; 60.2 cc and 20.9 cc in the lateral ventricles, 3.7 cc and 2.7 cc in the third ventricle. The hydrocephalus might be caused by obstructive mechanism but mostly by high venous pressure due to the shunt blood flow. The goal of treatment for hydrocephalus should be nidus obstruction and normalizing the vascular flow. 相似文献
992.
993.
994.
995.
Kevin C. Stieger James R. Eles Kip A. Ludwig Takashi D. Y. Kozai 《Journal of neuroscience research》2020,98(10):2072-2095
Electrical stimulation has been critical in the development of an understanding of brain function and disease. Despite its widespread use and obvious clinical potential, the mechanisms governing stimulation in the cortex remain largely unexplored in the context of pulse parameters. Modeling studies have suggested that modulation of stimulation pulse waveform may be able to control the probability of neuronal activation to selectively stimulate either cell bodies or passing fibers depending on the leading polarity. Thus, asymmetric waveforms with equal charge per phase (i.e., increasing the leading phase duration and proportionately decreasing the amplitude) may be able to activate a more spatially localized or distributed population of neurons if the leading phase is cathodic or anodic, respectively. Here, we use two-photon and mesoscale calcium imaging of GCaMP6s expressed in excitatory pyramidal neurons of male mice to investigate the role of pulse polarity and waveform asymmetry on the spatiotemporal properties of direct neuronal activation with 10-Hz electrical stimulation. We demonstrate that increasing cathodic asymmetry effectively reduces neuronal activation and results in a more spatially localized subpopulation of activated neurons without sacrificing the density of activated neurons around the electrode. Conversely, increasing anodic asymmetry increases the spatial spread of activation and highly resembles spatiotemporal calcium activity induced by conventional symmetric cathodic stimulation. These results suggest that stimulation polarity and asymmetry can be used to modulate the spatiotemporal dynamics of neuronal activity thus increasing the effective parameter space of electrical stimulation to restore sensation and study circuit dynamics. 相似文献
996.
997.
Lue Sun Yohei Inaba Yu Sogo Kumi Morikawa Naoki Kunugita Koichi Chida Takashi Moritake 《Journal of radiation research》2022,63(1):30
Ionizing radiation exposure affects the redox state in vivo. Recently, whole-blood antioxidant capacity (WBAC) has been reported to decrease in a dose-dependent manner after acute total body irradiation (TBI). However, changes in WBAC after localized and chronic irradiations have not been reported. This study analyzed changes to WBAC in mice after either localized irradiation (irradiation of the left hind leg only) or chronic TBI using the i-STrap method. Leg-localized irradiation exerted limited effects on WBAC, while WBAC decreased in a dose rate-dependent manner after TBI. Further, the WBAC reached the minimum value in a shorter period at a smaller dose rate. Our results suggest that changes in WBAC do not directly reflect absorbed dose, but may reflect radiation-induced biological damage at the systemic level. This study will contribute to the understanding of radiation-induced injuries and diseases, and will facilitate the establishment of biomarkers for radiation exposure. 相似文献
998.
Taito Mahoko Taito Shunsuke Banno Masahiro Fujiwara Takashi Okamura Hitoshi Tsujimoto Hiraku Kataoka Yuki Tsujimoto Yasushi 《European archives of oto-rhino-laryngology》2019,276(6):1573-1583
European Archives of Oto-Rhino-Laryngology - We aimed to determine whether voice rehabilitation after radiotherapy improves the quality of life (QOL), voice function, and self-rated voice function... 相似文献
999.
1000.
Takao Koike Seiichi Kobayashi Takashi Yoshiki Tetsuo Itoh Toshikazu Shirai 《Arthritis \u0026amp; Rheumatology》1979,22(10):1064-1073
By means of a modified sheep erythrocyte rosette inhibition assay, we were able to detect naturally occurring lymphocytotoxic antibodies in sera from patients with systemic lupus erythematosus (SLE). The incidence of lymphocytotoxic antibodies was 86% in all SLE patients, and 100% in patients with active disease. Since this assay detects only the antibodies that react with the determinants on T cells or on both T and B cells, it has a great advantage of demonstrating in combination with appropriate absorptions the antibodies specific for T cells. When an appropriate panel of target cells was used, most of the antibodies in SLE sera as detected by this assay appeared to be analogous to a natural thymocytotoxic autoantibody (NTA) of New Zealand mice in its specificity and nature. The changes in the antibody titer of a patient with SLE during the course of disease correlated well with those in the total number of T cells in the blood, the antinuclear antibody titer, and some delayed skin hypersensitivities. 相似文献