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   168721篇
  免费   11263篇
  国内免费   1232篇
耳鼻咽喉   2321篇
儿科学   3321篇
妇产科学   3950篇
基础医学   25297篇
口腔科学   3467篇
临床医学   16140篇
内科学   32339篇
皮肤病学   4490篇
神经病学   12944篇
特种医学   8176篇
外科学   22499篇
综合类   2219篇
现状与发展   5篇
一般理论   95篇
预防医学   10723篇
眼科学   4366篇
药学   14073篇
中国医学   1612篇
肿瘤学   13179篇
  2023年   1032篇
  2022年   2827篇
  2021年   5046篇
  2020年   2591篇
  2019年   3805篇
  2018年   4618篇
  2017年   3382篇
  2016年   4370篇
  2015年   5833篇
  2014年   7168篇
  2013年   8784篇
  2012年   13252篇
  2011年   12871篇
  2010年   7555篇
  2009年   6331篇
  2008年   9713篇
  2007年   9666篇
  2006年   8892篇
  2005年   8462篇
  2004年   7556篇
  2003年   6602篇
  2002年   5748篇
  2001年   4443篇
  2000年   4060篇
  1999年   3308篇
  1998年   1399篇
  1997年   1065篇
  1996年   1033篇
  1995年   914篇
  1994年   802篇
  1993年   707篇
  1992年   1611篇
  1991年   1598篇
  1990年   1386篇
  1989年   1268篇
  1988年   1184篇
  1987年   1057篇
  1986年   1030篇
  1985年   905篇
  1984年   678篇
  1983年   582篇
  1982年   441篇
  1981年   424篇
  1980年   360篇
  1979年   535篇
  1978年   429篇
  1977年   406篇
  1976年   358篇
  1974年   369篇
  1973年   337篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Scrub typhus usually presents as acute undifferentiated fever. This cross-sectional study included adult patients presenting with acute undifferentiated fever defined as any febrile illness for ≤ 14 days without evidence of localized infection. Scrub typhus cases were defined by an antibody titer of a ≥ fourfold increase in paired sera, a ≥ 1:160 in a single serum using indirect immunofluorescence assay, or a positive result of the immunochromatographic test. Multiple regression analysis identified predictors associated with scrub typhus to develop a prediction rule. Of 250 cases with known etiology of acute undifferentiated fever, influenza (28.0%), hepatitis A (25.2%), and scrub typhus (16.4%) were major causes. A prediction rule for identifying suspected cases of scrub typhus consisted of age ≥ 65 years (two points), recent fieldwork/outdoor activities (one point), onset of illness during an outbreak period (two points), myalgia (one point), and eschar (two points). The c statistic was 0.977 (95% confidence interval = 0.960–0.994). At a cutoff value ≥ 4, the sensitivity and specificity were 92.7% (79.0–98.1%) and 90.9% (86.0–94.3%), respectively. Scrub typhus, the third leading cause of acute undifferentiated fever in our region, can be identified early using the prediction rule.  相似文献   
22.
A classic pilomatricoma, which usually presents with an asymptomatic, solitary, firm, subcutaneous nodule in the head, neck, or extremities of the paediatric population, is easily diagnosed based on its characteristic clinical and histopathological features. However, its variants often pose particular diagnostic challenges to clinicians due to their rarity and diverse clinicopathological features. We present a new pseudocystic variant, manifesting as solid lesions floating in a fluid‐filled sac.  相似文献   
23.
Synovial chondromatosis is a rare lesion in the wrist, but some cases in the distal radioulnar joint have been reported and previous case reports emphasize joint calcifications, shown on preoperative plain radiographs. We report an extremely uncommon case of synovial chondromatosis in the pisotriquetral joint, in which radiographs and magnetic resonance imaging did not demonstrate apparent calcified bodies. In our case, for the accurate diagnosis and treatment, surgical exploration of the joint and synovectomy with removal of loose bodies was performed.  相似文献   
24.
25.
26.
The acquisition of chemoresistance remains a major cause of cancer mortality due to the limited accessibility of targeted or immune therapies. However, given that severe alterations of molecular features during epithelial‐to‐mesenchymal transition (EMT) lead to acquired chemoresistance, emerging studies have focused on identifying targetable drivers associated with acquired chemoresistance. Particularly, AXL, a key receptor tyrosine kinase that confers resistance against targets and chemotherapeutics, is highly expressed in mesenchymal cancer cells. However, the underlying mechanism of AXL induction in mesenchymal cancer cells is poorly understood. Our study revealed that the YAP signature, which was highly enriched in mesenchymal‐type lung cancer, was closely correlated to AXL expression in 181 lung cancer cell lines. Moreover, using isogenic lung cancer cell pairs, we also found that doxorubicin treatment induced YAP nuclear translocation in mesenchymal‐type lung cancer cells to induce AXL expression. Additionally, the concurrent activation of TGFβ signaling coordinated YAP‐dependent AXL expression through SMAD4. These data suggest that crosstalk between YAP and the TGFβ/SMAD axis upon treatment with chemotherapeutics might be a promising target to improve chemosensitivity in mesenchymal‐type lung cancer.

Abbreviations

AUC
area under the curve
AXL
AXL receptor tyrosine kinase
BCL2
B‐cell lymphoma 2
CTD2
cancer target discovery and development
CTGF
connective tissue growth factor
DEG
differentially expressed genes
DOXO
doxorubicin
EMT
epithelial–mesenchymal transition
Eto
etoposide
FDA
Food and Drug Administration
ITGB3
integrin beta‐3
MAPK
mitogen‐activated protein kinase
MMP2
matrix metalloproteinase‐2
MMP9
matrix metalloproteinase‐9
mRNA
messenger RNA
NF‐κB
nuclear factor kappa‐light‐chain‐enhancer of activated B cells
SBE
SMAD binding element
SERPINE1
serpin family E member 1
siRNA
small interfering RNA
ssGSEA
single‐sample gene set enrichment analysis
TCGA
The Cancer Genome Atlas
TGFβ
transforming growth factor beta
YAP
Yes‐associated protein
YAP8SA
mutants of inhibitory phosphorylation site at eight serine to Alanine of YAP
ZEB1
zinc finger E‐box binding homeobox 1
ZEB2
zinc finger E‐box‐binding homeobox 2
  相似文献   
27.
28.
29.
30.
Esophageal adenocarcinoma is the fastest rising cancer in the United States. It develops from long‐standing gastroesophageal reflux disease which affects >20% of the general population. It carries a very poor prognosis with 5‐year survival <20%. The disease is known to sequentially progress from reflux esophagitis to a metaplastic precursor, Barrett''s esophagus and then onto dysplasia and esophageal adenocarcinoma. However, only few patients with reflux develop Barrett''s esophagus and only a minority of these turn malignant. The reason for this heterogeneity in clinical progression is unknown. To improve patient management, molecular changes which facilitate disease progression must be identified. Animal models can provide a comprehensive functional and anatomic platform for such a study. Rats and mice have been the most widely studied but disease homology with humans has been questioned. No animal model naturally simulates the inflammation to adenocarcinoma progression as in humans, with all models requiring surgical bypass or destruction of existing antireflux mechanisms. Valuable properties of individual models could be utilized to holistically evaluate disease progression. In this review paper, we critically examined the current animal models of Barrett''s esophagus, their differences and homologies with human disease and how they have shaped our current understanding of Barrett''s carcinogenesis.  相似文献   
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