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   1682篇
  免费   81篇
  国内免费   35篇
耳鼻咽喉   16篇
儿科学   33篇
妇产科学   18篇
基础医学   268篇
口腔科学   16篇
临床医学   137篇
内科学   326篇
皮肤病学   27篇
神经病学   97篇
特种医学   171篇
外科学   151篇
综合类   25篇
预防医学   47篇
眼科学   22篇
药学   277篇
中国医学   43篇
肿瘤学   124篇
  2023年   11篇
  2022年   27篇
  2021年   57篇
  2020年   16篇
  2019年   28篇
  2018年   31篇
  2017年   29篇
  2016年   45篇
  2015年   70篇
  2014年   79篇
  2013年   96篇
  2012年   127篇
  2011年   116篇
  2010年   73篇
  2009年   69篇
  2008年   94篇
  2007年   130篇
  2006年   95篇
  2005年   98篇
  2004年   62篇
  2003年   68篇
  2002年   47篇
  2001年   28篇
  2000年   17篇
  1999年   21篇
  1998年   23篇
  1997年   25篇
  1996年   23篇
  1995年   11篇
  1994年   26篇
  1993年   16篇
  1992年   9篇
  1991年   7篇
  1990年   7篇
  1989年   20篇
  1988年   6篇
  1987年   11篇
  1986年   16篇
  1985年   13篇
  1984年   8篇
  1983年   8篇
  1982年   7篇
  1981年   9篇
  1980年   7篇
  1979年   1篇
  1978年   1篇
  1977年   6篇
  1975年   3篇
  1973年   1篇
排序方式: 共有1798条查询结果,搜索用时 15 毫秒
61.
62.
63.
OBJECTIVE: Dust generating events frequently produce ambient dust particles that are less than 10 microm in diameter, and these have been linked to adverse effects in the general population. However, the evidence linking these particles to adverse effects on the airways of asthmatic individuals is limited. The objective of this study was to investigate the possible adverse effects of Asian dust events on the respiratory functions and symptoms of subjects with bronchial asthma. METHODOLOGY: From March to June 2002, individuals were enrolled who had been diagnosed as having asthma by bronchial challenge or by their bronchodilator response. The patients were divided into three groups according to asthma severity: mild, moderate and severe. Patients with other major disease states were excluded. Patients completed twice-daily diaries monitoring PEF, respiratory symptoms, and daily activities. The daily and hourly mean levels of particulate matter <10 microm in diameter (PM(10)), as well as nitrogen dioxide (NO(2)), sulphur dioxide (SO(2)), ozone (O(3)) and carbon monoxide (CO) were measured at 10 monitoring sites in Incheon, Korea. RESULTS: Dust events occurred 14 times during the study period. On dusty days there were increased levels of PM(10), decreased levels of NO(2) and SO(2), and no change in the CO levels, compared to the levels on control days. An increase in PM(10) concentration was associated with increases in PEF variability of >20% (P<0.05), more night-time symptoms (P<0.05), and a decrease in the mean PEF (P<0.05), calculated by longitudinal data analysis. In contrast, there was no association between the PM(10) levels and bronchodilator inhaler use or daytime respiratory symptoms. Using a general additive Poisson regression model, a borderline association was noted between PM(10) and respiratory symptoms, with a relative risk of 1.05 (95% confidence interval (CI), 0.99--1.17). There was no association between the PM(10) concentrations and PEF measurements, with PEF variability of >20% between the morning and evening values and a relative risk of 1.05 (95% CI, 0.89--1.24) in all subjects. CONCLUSIONS: This study provides evidence that Asian dust events are impacting on the respiratory symptoms of subjects with bronchial asthma, and ambient air pollution, particularly elevated PM(10), might be one of the aggravating factors.  相似文献   
64.
Various reports on the prevalence of gastroesophageal reflux disease (GERD) and uninvestigated dyspepsia have been conducted in Western countries. We sought to determine the frequency of GERD symptoms and uninvestigated dyspepsia in Korea. Telephone interviews were conducted with 1,044 individuals. Of all subjects, 7.1% reported that GERD symptoms were present at least once a week, and 3.8% at least twice a week. The prevalence of heartburn according to educational level and acid regurgitation according to age was significantly different (P < 0.05). The prevalence of uninvestigated dyspepsia was reported as 12.2%. Dyspepsia was divided into subgroups of 34% ulcer-like, 56% dysmotility-like, and 10% nonspecific. The occurrence of dyspepsia did not vary according to age, gender, educational level and household income. As frequency of GERD symptoms increased, quality of life significantly decreased. We concluded that GERD symptoms and uninvestigated dyspepsia were prevalent in Korea. The prevalence was similar to that of other Asian countries.  相似文献   
65.
BackgroundWe investigated whether fibrinogen to albumin ratio (FAR) at diagnosis could reflect the cross‐sectional activity and predict poor outcomes in patients with antineutrophil cytoplasmic antibody (ANCA)‐associated vasculitis (AAV).MethodsThis cross‐sectional study included 54 immunosuppressant drug‐naïve patients with AAV who had the results of plasma fibrinogen and serum albumin at diagnosis. Clinical and laboratory data at diagnosis were collected, and all‐cause mortality, cerebrovascular accident, cardiovascular disease, end‐stage renal disease occurrences were assessed as poor outcomes. FAR was calculated by the following equation: FAR = plasma fibrinogen (g/dl)/serum albumin (g/dl).ResultsThe median age was 65.5 years, and 59.3% of patients were men (33 MPA, 13 GPA and 8 EGPA). FAR was significantly correlated with Birmingham vasculitis activity score (BVAS; r = 0.271), erythrocyte sedimentation rate (ESR; r = 0.668) and C‐reactive protein (CRP; r = 0.638). High BVAS was defined as BVAS ≥16, and the cut‐off of FAR at diagnosis was set as 0.118. AAV patients with FAR at diagnosis ≥0.118 had a significantly higher risk for the cross‐sectional high BVAS than those without (RR 3.361). In the univariable linear regression analysis, CRP (β = 0.383) and FAR (β = 0.297) were significantly correlated with BVAS at diagnosis. However, in the multivariable analysis, none of them was correlated with the cross‐sectional BVAS. FAR at diagnosis could not predict poor outcomes during follow‐up in AAV patients.ConclusionsFibrinogen to albumin ratio at diagnosis could reflect the cross‐sectional BVAS but could not predict poor outcomes in patients with AAV.  相似文献   
66.
SUMMARY We report an unusual case of a pharyngeal diverticulum arising as a result of extrusion of a bone graft inserted during anterior cervical fusion operation. The dense scar tissue at the site of extrusion of the bone graft probably caused traction on the posterior pharyngeal wall, with the development of a pharyngeal pouch. This is believed to be the first case with acquired pharyngeal diverticulum following anterior cervical fusion to be recorded in the literature.  相似文献   
67.

Ethnopharmacological relevance

Artemisia capillaris Thunberg (Compositae) have been used as traditional medicine as a diuretic, liver protective agent, and for amelioration of inflammatory and analgesic disorders. The present study was carried out to establish the scientific rationale for treating inflammation and to find active principles from A. capillaris.The aim of the present study is to investigate the possible anti-inflammatory mechanism of the major component (capillarisin) isolated from A. capillaris via inhibition of MyD88/TIRAP inflammatory signaling both in vitro and in vivo models.

Materials and methods

The nitrite, PGE2, and TNF-α productions were evaluated by Griess reagent and ELISA kits. The protein and mRNA expression levels were investigated by Western blot and RT-PCR. The NF-κB and AP-1 DNA-binding was performed by electrophoretic mobility shift assay. The CFA- and carrageenan-induced paw edema was performed in ICR mice in which 20 and 80 mg/kg body weight of capillarisin was administered intraperitoneally (i.p.).

Results

The results demonstrated that pretreatment with capillarisin effectively inhibited the LPS-induced activation of NF-κB, Akt, and MAP kinase-activated inflammatory genes, which is mediated by MyD88 and TIRAP. Treatment with capillarisin reduced the mRNA and protein levels of iNOS and COX-2 in RAW 264.7 cells as assessed by RT-PCR and Western blot. Capillarisin suppressed LPS-induced inhibitory kappa kinase (IKK) phosphorylation and the degradation of inhibitory kappa B (IκBα) and prevented the nuclear translocation of p65 and p50. Capillarisin also exhibited a promising inhibitory effect on the LPS-induced NF-κB and AP-1 DNA binding activity based on an electrophoretic mobility shift assay. The LPS-induced activation of p-JNK, p-p38, p-ERK, and p-Akt was significantly inhibited. In addition, the TNF-α level in the media was effectively reduced by capillarisin. In vivo experimental analysis revealed that capillarisin (20 and 80 mg/kg, i.p.) inhibited complete Freund's adjuvant (CFA)-and carrageenan-induced paw edema, nitrite production in plasma, and TNF-α, a pro-inflammatory cytokine production.

Conclusion

The results presented here demonstrate that capillarisin has consistent anti-inflammatory properties and acts by inhibiting inflammatory mediators in in vitro and in vivo experimental models, and suggest its potential utility in the control of inflammatory disorders.  相似文献   
68.

Objectives

The aim of this study was to evaluate the HIV‐1 RNA pooled nucleic acid amplification testing (NAAT) strategy to screen pregnant women in the ‘window period’ of acute HIV infection (AHI) in rural South Africa.

Methods

In 2007 and 2008, 750 consecutive pregnant women on their first antenatal care visit to a primary health care clinic were tested anonymously for HIV infection. HIV‐1 RNA pooled NAAT was performed on HIV antibody‐negative samples. All positive pools were tested individually and positive samples were classified as incident cases to calculate HIV incidence.

Results

The overall HIV prevalence was 37.3% [95% confidence interval (CI) 34.3–41.3]. Of the 467 HIV antibody‐negative samples, four (0.9%) were HIV‐1 RNA‐positive. The mean viral load in the four samples was 386 260 HIV‐1 RNA copies/mL (range 64 200–1 228 130). The HIV incidence was 11.2% per year (95% CI 0.3–22.1) and all women with AHI were ≤21 years of age.

Conclusions

Identifying AHI in pregnancy is important for health interventions to reduce perinatal and heterosexual transmission of HIV, and to estimate HIV incidence for epidemiological surveillance.  相似文献   
69.
汉语阅读障碍儿童在本顿视觉保持测验中的反应特征   总被引:1,自引:0,他引:1  
目的:比较阅读障碍儿童与正常儿童在本顿视觉保持测验中的反应特征,探索阅读障碍儿童视觉空间记忆能力的特点。方法:①2005-07/2006-05在儿童发育行为门诊遴选阅读障碍儿童20名(平均年龄10.2岁),按1∶1配对原则,选择年龄、性别、年级和家庭状况等条件与阅读障碍组相似的20名正常阅读能力儿童为对照组(平均年龄10.1岁)。②应用国内修订版本顿视觉保持测验C式B法,D式C法和E式D法对两组儿童进行个别测试。C式图卡呈现5s后让被试默画(视觉记忆能力),D式图卡让被试临摹(视觉结构能力),E式图卡呈现10s后间隔15s再让被试默画(视觉延迟记忆能力)。③对两组儿童的视觉记忆保持能力、视觉结构能力和延迟记忆能力进行测试,分别记录两组儿童测验的正确分(每一图卡根据全或无的原则记1或0分,总分0~10)及错误次数(错误类型分为遗漏或增加、变形、持续、旋转、位置错误和大小错误6个范畴),进行配对t检验。结果:40名受试者均进入结果分析。①正确得分:在视觉记忆和视觉结构能力测验中阅读障碍组低于对照组(5.00±2.45,6.60±1.82,P=0.019;7.50±2.44,8.95±1.32,P=0.015),在视觉延迟记忆测试中,两组得分比较差异不显著(P=0.077)。②总错误分:在视觉记忆和视觉结构能力测验中阅读障碍组高于对照组(7.65±4.20,4.90±3.24,P=0.016;3.20±3.93,1.15±1.46,P=0.035),在视觉延迟记忆测试中,两组得分比较差异不显著(P=0.389)。③错误类型:阅读障碍组儿童在视觉记忆能力测试中变形和持续性错误次数均显著多于对照组(3.95±2.40,1.75±1.52;0.35±0.67,0;P均<0.05),在视觉结构能力测试中变形错误次数显著多于对照组(1.35±1.69,0.35±0.75,P<0.05)。结论:阅读障碍儿童的视觉空间短时记忆能力、视觉结构和视觉运动整合能力存在缺陷。  相似文献   
70.
Su-A.  KIM  Sang-Won  UM  Jae-Uk  SONG  Kyeongman  JEON  Won-Jung  KOH  Gee Young  SUH  Man Pyo  Jung  O. Jung  KWON  Jong Heon  PARK  Chin A.  YI  Joungho  HAN  Hojoong  KIM 《Respirology (Carlton, Vic.)》2010,15(1):150-154
Background and objective: Bronchoscopic resection of endobronchial hamartomas has been reported to have a favourable outcome. This study describes the bronchoscopic features of endobronchial hamartoma and reports the clinical outcome of bronchoscopic intervention. Methods: A retrospective analysis was conducted of patients with histologically proven endobronchial hamartomas, diagnosed in the 10‐year period 1999–2009 to elucidate the clinical, radiological and bronchoscopic features of hamartoma and to describe the clinical outcomes. Results: Seventeen of the 135 patients with pulmonary hamartomas were diagnosed as having endobronchial hamartomas. CXR was abnormal in 11 of the 17 patients. On chest CT (n = 16), the median diameter of the lesion was 15.6 mm. Calcification and areas of focal fat in the lesion, the diagnostic CT findings of pulmonary hamartoma, were found in two of 16 (12.5%) patients. At bronchoscopy (n = 16), all tumours had a mass appearance and most were smooth surfaced round masses (50.0%) with 18.8% having a ‘stalk’. Bronchoscopic forceps biopsies were performed in 13 patients, which resulted in five patients (38.5%) being diagnosed with endobronchial hamartoma. Fifteen patients were treated with rigid or flexible bronchoscopic resection, one had lobectomy, and one had no intervention. No procedure‐related mortalities or late complications developed. Conclusions: Bronchoscopic intervention appears to be a safe and effective method to resect endobronchial hamartomas.  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