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   1737029篇
  免费   128464篇
  国内免费   5622篇
耳鼻咽喉   24948篇
儿科学   53531篇
妇产科学   46689篇
基础医学   246846篇
口腔科学   47146篇
临床医学   150204篇
内科学   349435篇
皮肤病学   39064篇
神经病学   133972篇
特种医学   69814篇
外国民族医学   716篇
外科学   267209篇
综合类   37240篇
现状与发展   7篇
一般理论   492篇
预防医学   118763篇
眼科学   39719篇
药学   133968篇
  3篇
中国医学   5793篇
肿瘤学   105556篇
  2021年   14609篇
  2019年   14491篇
  2018年   20696篇
  2017年   15589篇
  2016年   17568篇
  2015年   20759篇
  2014年   28122篇
  2013年   39803篇
  2012年   55607篇
  2011年   57401篇
  2010年   34452篇
  2009年   32092篇
  2008年   52490篇
  2007年   55783篇
  2006年   55230篇
  2005年   53008篇
  2004年   50983篇
  2003年   48846篇
  2002年   47123篇
  2001年   90147篇
  2000年   93116篇
  1999年   78555篇
  1998年   20633篇
  1997年   18144篇
  1996年   18060篇
  1995年   17024篇
  1994年   15923篇
  1993年   14674篇
  1992年   59544篇
  1991年   57329篇
  1990年   55463篇
  1989年   53358篇
  1988年   48779篇
  1987年   47639篇
  1986年   44227篇
  1985年   42114篇
  1984年   30737篇
  1983年   25708篇
  1982年   14409篇
  1981年   12922篇
  1979年   26665篇
  1978年   18153篇
  1977年   15522篇
  1976年   13966篇
  1975年   15238篇
  1974年   17729篇
  1973年   16983篇
  1972年   15783篇
  1971年   14443篇
  1970年   13552篇
排序方式: 共有10000条查询结果,搜索用时 970 毫秒
91.
92.
In the 6th Basic Plan for Long-Term Electricity Supply and Demand (6th BPE) for Korea, for the first time, the environmental costs of air pollution caused by oxides of sulfur (SOx), oxides of nitrogen (NOx), and particulate matters (PM) from power plants were estimated and included. However, several deficiencies in evaluating the environmental costs were found. In this study, (1) the validity of the environmental costs used in the 6th BPE was assessed, (2) a systematic approach was suggested and used to improve the environmental costs estimation, and (3) the sensitivity of the cost of generating electricity to the environmental costs by fuel type with the proposed approach was discussed. We found that the applied environmental costs used in the 6th BPE did not fully include the demographic characteristics of Korea. By applying more realistic parameter values, it was found that the newly estimated environmental cost was about 23 times higher than the cost estimated in the original 6th BPE for coal-fired power plants and about 1.5 times higher for liquefied natural gas (LNG)-fired power plants, suggesting that LNG-fired power plants are more economical if using more realistic environmental costs. Thus, it is critical to check the validity of parameter values when calculating environmental costs.  相似文献   
93.
94.
95.
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   
96.
Objective: Report efficacy findings from three clinical trials (one phase 2 and two phase 3 [OPUS-1, OPUS-2]) of lifitegrast ophthalmic solution 5.0% for treatment of dry eye disease (DED).

Research design and methods: Three 84-day, randomized, double-masked, placebo-controlled trials. Adults (≥18 years) with DED were randomized (1:1) to lifitegrast 5.0% or matching placebo. Changes from baseline to day 84 in signs and symptoms of DED were analyzed.

Main outcome measures: Phase 2, pre-specified endpoint: inferior corneal staining score (ICSS; 0–4); OPUS-1, coprimary endpoints: ICSS and visual-related function subscale (0–4 scale); OPUS-2, coprimary endpoints: ICSS and eye dryness score (EDS, VAS; 0–100).

Results: Fifty-eight participants were randomized to lifitegrast 5.0% and 58 to placebo in the phase 2 trial; 293 to lifitegrast and 295 to placebo in OPUS-1; 358 to lifitegrast and 360 to placebo in OPUS-2. In participants with mild-to-moderate baseline DED symptomatology, lifitegrast improved ICSS versus placebo in the phase 2 study (treatment effect, 0.35; 95% CI, 0.05–0.65; p?=?0.0209) and OPUS-1 (effect, 0.24; 95% CI, 0.10–0.38; p?=?0.0007). Among more symptomatic participants (baseline EDS ≥40, recent artificial tear use), lifitegrast improved EDS versus placebo in a post hoc analysis of OPUS-1 (effect, 13.34; 95% CI, 2.35–24.33; nominal p?=?0.0178) and in OPUS-2 (effect, 12.61; 95% CI, 8.51–16.70; p?<?0.0001).

Limitations: Trials were conducted over 12 weeks; efficacy beyond this period was not assessed.

Conclusions: Across three trials, lifitegrast improved ICSS in participants with mild-to-moderate baseline symptomatology in two studies, and EDS in participants with moderate-to-severe baseline symptomatology in two studies. Based on the overall findings from these trials, lifitegrast shows promise as a new treatment option for signs and symptoms of DED.  相似文献   
97.
98.
99.
100.
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