全文获取类型
收费全文 | 30515篇 |
免费 | 2919篇 |
国内免费 | 2211篇 |
专业分类
耳鼻咽喉 | 225篇 |
儿科学 | 501篇 |
妇产科学 | 360篇 |
基础医学 | 3474篇 |
口腔科学 | 574篇 |
临床医学 | 4033篇 |
内科学 | 4821篇 |
皮肤病学 | 293篇 |
神经病学 | 1449篇 |
特种医学 | 1457篇 |
外国民族医学 | 12篇 |
外科学 | 3408篇 |
综合类 | 4893篇 |
现状与发展 | 6篇 |
一般理论 | 3篇 |
预防医学 | 1975篇 |
眼科学 | 690篇 |
药学 | 3198篇 |
27篇 | |
中国医学 | 1588篇 |
肿瘤学 | 2658篇 |
出版年
2024年 | 95篇 |
2023年 | 453篇 |
2022年 | 1107篇 |
2021年 | 1390篇 |
2020年 | 1048篇 |
2019年 | 943篇 |
2018年 | 979篇 |
2017年 | 952篇 |
2016年 | 972篇 |
2015年 | 1344篇 |
2014年 | 1664篇 |
2013年 | 1527篇 |
2012年 | 1965篇 |
2011年 | 2348篇 |
2010年 | 1551篇 |
2009年 | 1222篇 |
2008年 | 1523篇 |
2007年 | 1635篇 |
2006年 | 1544篇 |
2005年 | 1495篇 |
2004年 | 1145篇 |
2003年 | 1148篇 |
2002年 | 1026篇 |
2001年 | 890篇 |
2000年 | 805篇 |
1999年 | 762篇 |
1998年 | 510篇 |
1997年 | 566篇 |
1996年 | 392篇 |
1995年 | 345篇 |
1994年 | 275篇 |
1993年 | 230篇 |
1992年 | 238篇 |
1991年 | 217篇 |
1990年 | 198篇 |
1989年 | 185篇 |
1988年 | 157篇 |
1987年 | 149篇 |
1986年 | 138篇 |
1985年 | 93篇 |
1984年 | 59篇 |
1983年 | 40篇 |
1982年 | 25篇 |
1981年 | 21篇 |
1980年 | 32篇 |
1979年 | 49篇 |
1978年 | 28篇 |
1976年 | 24篇 |
1975年 | 27篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Hereditary spastic paraplegia (HSP) is a heterogeneous group of inherited neurodegenerative disease characterized by progressive lower limb spasticity. Recent studies revealed that biallelic variants in RNF170 gene cause autosomal recessive complicated HSP with infancy onset. Here, we report an adolescent-onset HSP patient from a consanguineous Chinese family, with lower extremity stiffness, spastic gait, and unstable straight-line walking as the main manifestations. Whole-exome sequencing identifies a novel RNF170 mutation c.190C>T (p.R64*), which co-segregates with the disease in this pedigree. Functional analysis, including quantitative real-time PCR (RT-qPCR) and Western blot, indicates that both the mRNA and protein levels of mutant RNF170 are significantly reduced, which confirms the loss-of-function mechanism. Our study expands the spectrum of RNF170-associated HSP, while the RNF170 protein-involved degradation of the inositol 1,4,5-trisphosphate receptor in neurodegenerative motor neuron disorders deserves further investigation. 相似文献
82.
Huimin Cheng Liangbing Fu Xia Yang Yujian Yang Zhening Zhang Yuan Tao Junting Wan Zhengchao Tu Jianxin Chen Yingjun Li 《Journal of medical virology》2023,95(1):e28327
Quinolin-2-one represents an important and valuable chemical motif that possesses a wide variety of biological activities; however, the anti-influenza activities of quinolin-2-one-containing compounds were rarely reported. Herein, we describe the screening and identification of 3-aryl-quinolin-2-one derivatives as a novel class of antiviral agents. The 3-aryl-quinolinone derivatives were synthesized via an efficient copper-catalyzed reaction cascade that we previously developed. Using this synthetic method, preliminary structure–activity relationships of this scaffold against the influenza A virus infection were systematically explored. The most potent compound 34 displayed IC50 values of 2.14 and 4.88 μM against the replication of H3N2 (A/HK/8/68) and H1N1 (A/WSN/33) strains, respectively, without apparent cytotoxicity on MDCK cells. We further demonstrated that 27 and 34 potently inhibited the plaque formation of the IAV, rendering this scaffold attractive for pursuing novel anti-influenza agents. 相似文献
83.
Clonal analysis of mndne T cells has led to the idenuncation of Z typeS of Th cells, Thl and on. Thl cells,chacterized by secreting interferon-y (Iap-Y), interleukin-2 (IL2) and tumor necrosis factor-5 (TNF-3), involved Principally in cell-mediated ~ity and play acrucial role in defending the host against intracellularPathogens such as a Vallety of yi~es. ThZ cells,secreting IL4, ms, IL-6 and ilo, mostly regulateh~ immune responSe, and may oafs Paxtial PIDtection against extracellula… 相似文献
84.
85.
86.
Ages at different reproductive events, numbers of menstrual cycles in between and breast cancer risk
One hundred and seventy-five pathologically confirmed new cases of female breast cancer in National Taiwan University Hospital were selected as the case group. Four hundred and fifty-seven inpatient controls were individually matched for each case by age and date of admission. Information of reproductive factors and potential confounders were collected from questionnaire interview and medical records. Menstrual cycles before and after first fuIl-term pregnancy were estimated from the questionnaire. Conditional logistic regression was used to estimate the effects of reproductive risk factors and numbers of menstrual cycles before and after first full-term pregnancy. After adjusting for educational level, body mass index, family history of breast cancer and oral contraceptive use, age at menarche and menopause only showed borderline significance. Age at first full-term birth predicted breast cancer risk better. Parity was the most important protective factor. Number of menstrual cycles before first full-term pregnancy was also positively associated with breast cancer risk with linear trends. 相似文献
87.
Fu YL Hu YX Ling HL Ye ZZ Liang T Zhang MG Liu YK Kang B Luo YJ He SY Lian YJ 《Infectious diseases in obstetrics and gynecology》1994,1(5):235-241
Objective: The objective of this study was to determine whether human papillomavirus (HPV) infections are involved in the development of papillomatosis lesions of the lower female genital tract.Methods: A total of 616 biopsy specimens of genital papillomatous lesions (307 nodular and 309 papular types) from 598 patients were anaylyzed for the presence of HPV DNA sequences by polymerase chain reaction (PCR). These specimens were also examined by histopathological assessment for characteristic HPV-associated cytological changes, by immunohistochemical staining for HPV-associated antigen, and by electron microscopy for the presence of virions.Results: HPV DNA sequences were found in 97.9% (140 of 143 cases) and 1.1% (1 of 91 cases) of the nodular and papular papillomatosis cases tested, respectively. In 18 patients who had both types of papillomatosis lesions, HPV DNA was invariably found only in nodular tissues. HPV-associated antigen, koilocytosis, and virions were found in 53.6% (98 of 183 cases), 70.5% (129 of 183 cases), and 5.9% (5 of 85 cases) of nodular papillomatosis lesions tested, respectively.Conclusions: These data suggest that nodular papillomatosis was closely associated with HPV infection, but that papular papillomatosis of the lower female genital tract may have an etiology other than HPV infection. 相似文献
88.
目的观察正常及模拟“缺血”时胺碘酮对绵羊心室浦肯野纤维起搏离子流(If)的影响。方法双微电极电压钳制术,使膜电位过度极化以激活If。结果胺碘酮1×10-5mol/L在正常台氏液中显著降低浦肯野纤维If幅值;模拟“缺血”也使If幅值降低,在此基础上,胺碘酮使If幅值进一步减小,加剧了“缺血”对If离子流的抑制作用。结论提示胺碘酮能抑制心肌缺血时心室正常自律性活动。 相似文献
89.
90.