首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15995篇
  免费   1231篇
  国内免费   55篇
耳鼻咽喉   106篇
儿科学   547篇
妇产科学   519篇
基础医学   2166篇
口腔科学   289篇
临床医学   1798篇
内科学   3464篇
皮肤病学   445篇
神经病学   1555篇
特种医学   375篇
外科学   1620篇
综合类   132篇
一般理论   10篇
预防医学   1876篇
眼科学   286篇
药学   967篇
  1篇
中国医学   56篇
肿瘤学   1069篇
  2023年   158篇
  2022年   166篇
  2021年   665篇
  2020年   392篇
  2019年   604篇
  2018年   627篇
  2017年   472篇
  2016年   399篇
  2015年   455篇
  2014年   640篇
  2013年   910篇
  2012年   1254篇
  2011年   1257篇
  2010年   671篇
  2009年   598篇
  2008年   942篇
  2007年   1002篇
  2006年   935篇
  2005年   860篇
  2004年   778篇
  2003年   728篇
  2002年   557篇
  2001年   185篇
  2000年   185篇
  1999年   176篇
  1998年   114篇
  1997年   89篇
  1996年   76篇
  1995年   77篇
  1994年   52篇
  1993年   68篇
  1992年   102篇
  1991年   76篇
  1990年   91篇
  1989年   78篇
  1988年   73篇
  1987年   78篇
  1986年   48篇
  1985年   65篇
  1984年   49篇
  1983年   70篇
  1982年   53篇
  1981年   40篇
  1980年   33篇
  1979年   38篇
  1978年   39篇
  1977年   26篇
  1976年   31篇
  1974年   25篇
  1973年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Osteogenesis imperfecta (OI) is a collagen-related bone disorder characterized by fragile osteopenic bone and muscle weakness. We have previously shown that the soluble activin receptor type IIB decoy (sActRIIB) molecule increases muscle mass and improves bone strength in the mild to moderate G610C mouse model of OI. The sActRIIB molecule binds multiple transforming growth factor-β (TGF-β) ligands, including myostatin and activin A. Here, we investigate the musculoskeletal effects of inhibiting activin A alone, myostatin alone, or both myostatin and activin A in wild-type (Wt) and heterozygous G610C (+/G610C) mice using specific monoclonal antibodies. Male and female Wt and +/G610C mice were treated twice weekly with intraperitoneal injections of monoclonal control antibody (Ctrl-Ab, Regn1945), anti-activin A antibody (ActA-Ab, Regn2476), anti-myostatin antibody (Mstn-Ab, Regn647), or both ActA-Ab and Mstn-Ab (Combo, Regn2476, and Regn647) from 5 to 16 weeks of age. Prior to euthanasia, whole body composition, metabolism and muscle force generation assessments were performed. Post euthanasia, hindlimb muscles were evaluated for mass, and femurs were evaluated for changes in microarchitecture and biomechanical strength using micro–computed tomography (μCT) and three-point bend analyses. ActA-Ab treatment minimally impacted the +/G610C musculoskeleton, and was detrimental to bone strength in male +/G610C mice. Mstn-Ab treatment, as previously reported, resulted in substantial increases in hindlimb muscle weights and overall body weights in Wt and male +/G610C mice, but had minimal skeletal impact in +/G610C mice. Conversely, the Combo treatment outperformed ActA-Ab alone or Mstn-Ab alone, consistently increasing hindlimb muscle and body weights regardless of sex or genotype and improving bone microarchitecture and strength in both male and female +/G610C and Wt mice. Combinatorial inhibition of activin A and myostatin more potently increased muscle mass and bone microarchitecture and strength than either antibody alone, recapturing most of the observed benefits of sActRIIB treatment in +/G610C mice. © 2022 American Society for Bone and Mineral Research (ASBMR).  相似文献   
13.
Maternal and Child Health Journal - Background Prenatal substance use screening is recommended. The 4 P’s Plus screener includes questions on perceived problematic substance use in parents...  相似文献   
14.
Globally, the COVID‐19 pandemic has already led to major increases in unemployment and is expected to lead to unprecedented increases in poverty and food and nutrition insecurity, as well as poor health outcomes. Families where young children, youth, pregnant and lactating women live need to be protected against the ongoing protracted pandemic and the aftershocks that are very likely to follow for years to come. The future wellbeing of the vast majority of the world now depends on reconfiguring the current ineffective food, nutrition, health, and social protection systems to ensure food and nutrition security for all. Because food, nutrition, health, and socio‐economic outcomes are intimately inter‐linked, it is essential that we find out how to effectively address the need to reconfigure and to provide better intersecoral coordination among global and local food, health care, and social protection systems taking equity and sutainability principles into account. Implementation science research informed by complex adaptive sytems frameworks will be needed to fill in the major knowledge gaps. Not doing so will not only put the development of individuals at further risk, but also negatively impact on the development potential of entire nations and ultimately our planet.  相似文献   
15.
16.
17.
Carcinosarcomas are biphasic tumors composed of admixed malignant epithelial and mesenchymal components. Numerous terms have been used to name such neoplasms; therefore, terminological confusion is frequent. Most examples of carcinosarcomas are encountered in non‐cutaneous sites, with approximately 100 cases of cutaneous carcinosarcomas reported so far in the English literature. Although different theories have been suggested to explain the occurrence of these peculiar neoplasms, histogenetic mechanisms should be better hypothesized depending on each individual case. Even though prognosis tends to be related to the specific components of the lesion, especially the epithelial one, it seems that cases of cutaneous localization usually have a better outcome. We report an exceedingly rare case of syringocystadenocarcinoma papilliferum which showed an atypical stroma with sarcomatoid appearance, and highlight that the terminology used for this spectrum of lesions is disorganized and confusing.  相似文献   
18.
2‐deoxy D‐glucose (2DG) was tested for efficacy in treating alopecia areata using the C3H/HeJ skin graft model. 2DG has proven to be efficacious in treatment of various mouse models of autoimmunity with minimal serious side effects noted. This agent has been shown to normalize abnormally activated T‐cell populations while also preventing cell surface expression of NKG2D; key factors defining alopecia areata disease progression. Daily oral ingestion of 2DG via drinking water to mice with patchy or diffuse alopecia areata for 16 weeks failed to prevent expansion of alopecia or cause regrowth of hair in treated mice. Histologically, there were no differences between treated and control groups. These results indicate that, while 2DG is effective for some autoimmune diseases, it was not efficacious for the cell‐mediated autoimmune mouse disease, alopecia areata.  相似文献   
19.
There is little long-term follow-up information about how the number of melanoma deaths and case fatality vary over time according to the measured thickness of melanoma at diagnosis. This population-based longitudinal cohort study examines patterns and trends in case fatality among 44,531 people in Queensland (Australia) diagnosed with a single invasive melanoma (International Classification of Diseases for Oncology, third revision [ICD-O-3], C44, Morphology 872–879) between 1987 and 2011, including 11,883 diagnosed between 1987 and 1996, with up to 20 years follow-up (to December 2016). The 20-year case fatality increased by thickness, with the percentage of melanoma deaths within 20 years of diagnosis being up to 4.8% for melanomas with measured thickness <0.80 mm, 10.6% for tumors 0.8 to <1.0 mm and generally more than 30% for melanomas measuring 3 mm and more. For melanomas <1.0 mm, most deaths occurred between 5 and 20 years after diagnosis, whereas for thicker melanomas the reverse was true with most deaths occurring within the first 5 years. Five-year case fatality decreased over successive calendar time periods for melanomas <1.0 mm, but not for melanomas ≥1.0 mm. These findings demonstrate that the time course for fatal melanomas varies markedly according to tumor thickness at diagnosis. Improved understanding of the patient factors and characteristics of melanomas, in addition to tumor thickness, which increase the likelihood of progression, is needed to guide clinical diagnosis, communication with patients and ongoing surveillance pathways of patients with potentially fatal lesions.  相似文献   
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号