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   6623篇
  免费   366篇
  国内免费   12篇
耳鼻咽喉   55篇
儿科学   422篇
妇产科学   113篇
基础医学   578篇
口腔科学   222篇
临床医学   422篇
内科学   1448篇
皮肤病学   288篇
神经病学   490篇
特种医学   160篇
外科学   974篇
综合类   199篇
一般理论   1篇
预防医学   318篇
眼科学   326篇
药学   592篇
中国医学   19篇
肿瘤学   374篇
  2023年   46篇
  2022年   34篇
  2021年   198篇
  2020年   114篇
  2019年   204篇
  2018年   255篇
  2017年   187篇
  2016年   224篇
  2015年   223篇
  2014年   323篇
  2013年   339篇
  2012年   555篇
  2011年   621篇
  2010年   326篇
  2009年   241篇
  2008年   362篇
  2007年   372篇
  2006年   296篇
  2005年   273篇
  2004年   240篇
  2003年   188篇
  2002年   189篇
  2001年   110篇
  2000年   118篇
  1999年   92篇
  1998年   46篇
  1997年   21篇
  1996年   19篇
  1995年   39篇
  1994年   18篇
  1992年   70篇
  1991年   67篇
  1990年   42篇
  1989年   38篇
  1988年   54篇
  1987年   39篇
  1986年   32篇
  1985年   38篇
  1984年   27篇
  1983年   23篇
  1979年   22篇
  1977年   16篇
  1975年   16篇
  1974年   26篇
  1973年   15篇
  1972年   27篇
  1971年   19篇
  1970年   15篇
  1969年   16篇
  1968年   18篇
排序方式: 共有7001条查询结果,搜索用时 23 毫秒
1.
Treatment guidelines for management of uncomplicated gonorrhoeae have been recently modified owing to alarming upsurge in azithromycin resistance. This study investigated the prevalence and genetic determinants of gonococcal azithromycin resistance in India. Four (5.7%) of 70 gonococcal isolates were resistant to azithromycin. Of 16 isolates investigated for molecular mechanisms of resistance, 13 (81.3%) and 6 (37.5%) isolates exhibited mutations in coding and promoter regions of mtrR gene, respectively. However, ermA, ermB and ermC genes or mutations in rrl gene were absent in all isolates. Azithromycin resistance is low in India posing no immediate threat to use of dual-therapy for syndromic management.  相似文献   
2.
3.
Raghib syndrome is a rare developmental complex consisting of termination of the left superior vena cava in the left atrium, absence of the coronary sinus, and an atrial septal defect commonly located at the posterior‐inferior angle of the atrial septum. This complex was considered unique to Raghib syndrome; however, cases with a normal atrial septum have been reported where the orifice of the unroofed coronary sinus functions as the inter‐atrial communication. Our patient demonstrated an isolated persistent left superior vena cava draining into the left atrium through unroofed coronary sinus and presence of ostium primum atrial septal defect.  相似文献   
4.
The efforts for the development and testing of vaccines against Trypanosoma cruzi infection have increased during the past years. We have designed a TcVac series of vaccines composed of T. cruzi derived, GPI-anchored membrane antigens. The TcVac vaccines have been shown to elicit humoral and cellular mediated immune responses and provide significant (but not complete) control of experimental infection in mice and dogs. Herein, we aimed to test two immunization protocols for the delivery of DNA-prime/DNA-boost vaccine (TcVac1) composed of TcG2 and TcG4 antigens in a BALB/c mouse model. Mice were immunized with TcVac1 through intradermal/electroporation (IDE) or intramuscular (IM) routes, challenged with T. cruzi, and evaluated during acute phase of infection. The humoral immune response was evaluated through the assessment of anti-TcG2 and anti-TcG4 IgG subtypes by using an ELISA. Cellular immune response was assessed through a lymphocyte proliferation assay. Finally, clinical and morphopathological aspects were evaluated for all experimental animals. Our results demonstrated that when comparing TcVac1 IDE delivery vs IM delivery, the former induced significantly higher level of antigen-specific antibody response (IgG2a?+?IgG2b?>?IgG1) and lymphocyte proliferation, which expanded in response to challenge infection. Histological evaluation after challenge infection showed infiltration of inflammatory cells (macrophages and lymphocytes) in the heart and skeletal tissue of all infected mice. However, the largest increase in inflammatory infiltrate was observed in TcVac1_IDE/Tc mice when compared with TcVac1_IM/Tc or non-vaccinated/infected mice. The extent of tissue inflammatory infiltrate was directly associated with the control of tissue amastigote nests in vaccinated/infected (vs. non-vaccinated/infected) mice. Our results suggest that IDE delivery improves the protective efficacy of TcVac1 vaccine against T. cruzi infection in mice when compared with IM delivery of the vaccine.  相似文献   
5.
6.
7.
8.
9.
Objectives

To find out the relative prevalence of fetal neural tube defect (NTD) and its outcome in terms of survival at birth and beyond 2 years of age.

Methods

A 10-year prospective (2008–2018) observational study was performed, which included all prenatally detected fetal NTD. Two-year follow-up was done in cases of pregnancies resulting in live birth, in terms of their survival, physical morbidity and developmental delay.

Results

NTD was seen in 401/648 (62%) cases among the central nervous system malformations. More than half of the cases (54.1%) presented after 20 weeks of gestation, and 42.8% of the mothers were primiparous. Spina bifida was seen in 206 cases, anencephaly in 144, encephalocele in 43, whereas iniencephaly was seen in only eight cases. Associated anomalies were present in 51.2%. Only 19.0% cases were live-born, and merely 11% were alive beyond 2 years of age. Among types of spina bifida, lumbosacral meningomyocele was the most common (41.6%), whereas thoracic was the rarest (8.7%). After 2 years, physical disability was observed in more than half of the cases who survived.

Conclusions

NTD is one of the commonest malformations with high mortality, and the physical and mental sub-normality is high among those who survive.

  相似文献   
10.
PDE type 5 inhibitors (PDE5Is), such as sildenafil, tadalafil and vardenafil, are a class of drugs used to prolong the physiological effects of NO/cGMP signalling in tissues through the inhibition of cGMP degradation. Although these agents were originally developed for the treatment of hypertension and angina, unanticipated side effects led to advances in the treatment of erectile dysfunction and, later, pulmonary arterial hypertension. In the last decade, accumulating evidence suggests that PDE5Is may confer a wider range of clinical benefits than was previously recognised. This has led to a broader interest in the cardiovascular therapeutic potential of PDE5Is, in conditions such as hypertension, myocardial infarction, stroke, peripheral arterial disease, chronic kidney disease and diabetes mellitus. Here, we review the pharmacological properties and established licensed uses of this class of drug, along with emerging therapeutic developments and possible future indications.

Abbreviations

6MWD
6‐min walking distance
ACEI
ACE inhibitor
ARB
angiotensin receptor blocker
BPS
British Pharmacological Society
CCB
calcium channel blocker
CKD
chronic kidney disease
Cmax
maximum plasma/serum concentration
CTEPH
chronic thromboembolic pulmonary hypertension
CVD
cardiovascular disease
CYP2C19
cytochrome P450, family 2, subfamily C, polypeptide 19
CYP2C9
cytochrome P450, family 2, subfamily C, polypeptide 9
CYP2D6
cytochrome P450, family 2, subfamily D, polypeptide 6
CYP3A
cytochrome P450, family 3, subfamily A
CYP3A4
cytochrome P450, family 3, subfamily A, polypeptide 4
CYP450
cytochrome P450 enzyme family
DN
diabetic nephropathy
ED
erectile dysfunction
eGFR
estimated GFR
ERA
endothelin receptor antagonist
ET
endothelin
ET‐1
endothelin‐1
FGR
fetal growth restriction
GSK3B
glycogen synthase kinase 3 β
HbA1c
glycated Hb
HFpEF
heart failure with preserved ejection fraction
HFrEF
heart failure with reduced ejection fraction
IC50
half maximal inhibitory concentration
IUPHAR
International Union of Basic and Clinical Pharmacology
MI
myocardial infarction
mitoKATP
mitochondrial ATP‐sensitive potassium channels
NAION
nonarteritic anterior ischaemic optic neuropathy
Na+/K+‐ATPase
sodium–potassium pump
NOS1
neuronal NOS
NOS2
inducible NOS
NOS3
endothelial NOS
PAH
pulmonary arterial hypertension
PDE5I
PDE type 5 inhibitor
PH
pulmonary hypertension
PPHN
persistent pulmonary hypertension of the newborn
RCT
randomised controlled trial
RHTN
treatment‐resistant hypertension
RP
Raynaud''s phenomenon
sGC
soluble GC
SGLT2
sodium–glucose cotransporter 2
Tmax
time taken to reach the maximum plasma concentration
T2DM
type 2 diabetes mellitus
UACR
urinary albumin/creatinine ratio
V/Q
ventilation/perfusion
  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