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   3126篇
  免费   162篇
  国内免费   110篇
耳鼻咽喉   15篇
儿科学   85篇
妇产科学   87篇
基础医学   485篇
口腔科学   27篇
临床医学   357篇
内科学   667篇
皮肤病学   99篇
神经病学   144篇
特种医学   468篇
外科学   329篇
综合类   34篇
预防医学   155篇
眼科学   64篇
药学   172篇
中国医学   10篇
肿瘤学   200篇
  2023年   13篇
  2022年   57篇
  2021年   63篇
  2020年   36篇
  2019年   42篇
  2018年   69篇
  2017年   46篇
  2016年   83篇
  2015年   91篇
  2014年   116篇
  2013年   148篇
  2012年   188篇
  2011年   193篇
  2010年   133篇
  2009年   134篇
  2008年   150篇
  2007年   176篇
  2006年   115篇
  2005年   141篇
  2004年   103篇
  2003年   97篇
  2002年   90篇
  2001年   108篇
  2000年   100篇
  1999年   56篇
  1998年   100篇
  1997年   89篇
  1996年   65篇
  1995年   60篇
  1994年   52篇
  1993年   49篇
  1992年   40篇
  1991年   25篇
  1990年   35篇
  1989年   46篇
  1988年   40篇
  1987年   35篇
  1986年   25篇
  1985年   24篇
  1984年   23篇
  1983年   16篇
  1982年   22篇
  1981年   10篇
  1980年   15篇
  1979年   8篇
  1978年   10篇
  1977年   18篇
  1976年   15篇
  1975年   14篇
  1900年   2篇
排序方式: 共有3398条查询结果,搜索用时 0 毫秒
81.

Introduction

Low bone mass is prevalent in HIV-positive patients. However, compared to Western countries, less is known about HIV-associated osteopenia in Asian populations.

Methods

We performed a cross-sectional survey in Seoul National University Hospital from December 2011 to May 2012. We measured bone mineral density using central dual energy X-ray absorptiometry, with consent, in male HIV-positive patients, aged 40 years and older. Diagnosis of low bone mass was made using International Society for Clinical Densitometry Z-score criteria in the 40–49 years age group and World Health Organization T-score criteria in the >50-year age group. The data were compared with those of a community-based cohort in Korea.

Results

Eighty-four HIV-positive male patients were included in this study. Median age was 49 (interquartile range [IQR], 45–56) years, and median body mass index (BMI) was 22.6 (IQR, 20.9–24.4). Viral suppression was achieved in 75 (89.3%) patients and median duration of antiretroviral therapy was 71 (IQR, 36–120) months. The overall prevalence of low bone mass was 16.7% in the 40–49 years age group and 54.8% in the>50 years age group. Our cohort had significantly lower bone mass at the femur neck and total hip than HIV-negative Koreans in the 40–49 years age group. Low bone mass was significantly associated with low BMI, and a high level of serum carboxy-terminal collagen crosslinks, but was not associated with antiretroviral regimen or duration of antiretroviral therapy.

Conclusions

Low bone mass is prevalent in Korean HIV-positive males undergoing antiretroviral therapy, and may be associated with increased bone resorption.  相似文献   
82.

Background/Aims

A close relationship has been established between nonalcoholic fatty liver disease (NAFLD) and an elevated risk of coronary heart disease (CHD), but little is known about the association between alcoholic fatty liver disease (AFLD) and CHD risk. The aim of this study was to determine whether AFLD is associated with elevated CHD risk.

Methods

We retrospectively enrolled 10,710 subjects out of 11,469 individuals who visited the Konkuk University Health Care Center for a routine health checkup in 2010. AFLD was diagnosed made when the usual amount of alcohol consumption exceeded 210 g/week in males and 140 g/week in females for the previous 2 years and when hepatic steatosis was detected by liver ultrasonography. The 10-year risk for CHD was estimated using the Framingham Risk Score.

Results

Hepatic steatosis was diagnosed in 4,142 of the 10,710 individuals (38.7%); the remainder (i.e., n=6,568) became the control group. The 4,142 individuals with hepatic steatosis were divided into two groups: NAFLD (n=2,953) and AFLD (n=1,189). The risk of CHD was higher in AFLD (6.72±0.12) than in the control group (5.50±0.04, P<0.001), and comparable to that in NAFLD (7.32±0.07, P=0.02).

Conclusions

Individuals with AFLD have an elevated 10-year risk of CHD that is comparable to those with NAFLD. Therefore, AFLD should be considered a significant risk for future CHD, and preventive measures should be considered earlier.  相似文献   
83.

Background/Aims

A revised classification system for renal dysfunction in patients with cirrhosis was proposed by the Acute Dialysis Quality Initiative and the International Ascites Club Working Group in 2011. The aim of this study was to determine the prevalence of renal dysfunction according to the criteria in this proposal.

Methods

The medical records of cirrhotic patients who were admitted to Konkuk University Hospital between 2006 and 2010 were reviewed retrospectively. The data obtained at first admission were collected. Acute kidney injury (AKI) and chronic kidney disease (CKD) were defined using the proposed diagnostic criteria of kidney dysfunction in cirrhosis.

Results

Six hundred and forty-three patients were admitted, of whom 190 (29.5%), 273 (42.5%), and 180 (28.0%) were Child-Pugh class A, B, and C, respectively. Eighty-three patients (12.9%) were diagnosed with AKI, the most common cause for which was dehydration (30 patients). Three patients had hepatorenal syndrome type 1 and 26 patients had prerenal-type AKI caused by volume deficiency after variceal bleeding. In addition, 22 patients (3.4%) were diagnosed with CKD, 1 patient with hepatorenal syndrome type 2, and 3 patients (0.5%) with AKI on CKD.

Conclusions

Both AKI and CKD are common among hospitalized cirrhotic patients, and often occur simultaneously (16.8%). The most common type of renal dysfunction was AKI (12.9%). Diagnosis of type 2 hepatorenal syndrome remains difficult. A prospective cohort study is warranted to evaluate the clinical course in cirrhotic patients with renal dysfunction.  相似文献   
84.
Radio-frequency ablation (RFA) is a curative treatment for hepatocellular carcinoma (HCC). Percutaneous RFA has been shown to be beneficial for patients with small renal cell carcinoma (RCC) lacking indications for resection. We experienced the case of a 53-year-old male who had conditions that suggested HCC, RCC, and alcoholic liver cirrhosis. Abdominal contrast-enhanced computed tomography (CT) and magnetic resonance image showed liver cirrhosis with 2.8 cm ill-defined mass in segment 2 of the liver and 1.9 cm hypervascular mass in the left kidney. These findings were compatible with the double primary cancers of HCC and RCC. Transarterial chemoembolization (TACE) was performed to treat the HCC. After the TACE, a focal lipiodol uptake defect was noticed on a follow up CT images and loco-regional treatment was recommended. Therefore, we performed RFAs to treat HCC and RCC. There was no evidence of recurrence in the follow up image after 1 month.  相似文献   
85.
Following nonpharmaceutical intervention (NPI) to mitigate coronavirus disease 2019 has led to drastic reduction in incidence of communicable disease. Intussusception is commonly preceded by infectious pathogens. Indirect effect from NPI implementation on incidence of intussusception has not been understood fully. We conducted a cohort study to estimate the impact of NPI on incidence of intussusception in Korean children. The net risk ratio of intussusception incidence for 2020 compared to 2010–2019 was 0.53 (95% confidence interval [CI], 0.43–0.64) for boys and 0.56 (95% CI, 0.44–0.71) for girls (P for difference = 0.017). Our study showed an association between NPI implementation and reduction of intussusception incidence, with more profound reduction in boys compared to girls.  相似文献   
86.
A series of Co(ii), Zn(ii), and Cd(ii) complexes supported by 1-(3,5-dimethyl-1H-pyrazol-1-yl)-N-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-N-(furan-2-ylmethyl)methanamine (LA) and N,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-4-isopropylaniline (LB) were synthesized. The direct chelation of CoCl2·6H2O, ZnCl2, and CdBr2·4H2O by the ligands produced [LnMX2] (Ln = LA or LB; M = Zn or Co, with X = Cl; M = Cd, with X = Br) complexes in high yields. Structural studies revealed that [LBCoCl2] and [LBZnCl2] adopted distorted tetrahedral geometries, as LB coordinated the metal centers in a bidentate fashion, while LA coordinated the metal centers in a tridentate fashion through the nitrogen atoms of the pyrazole and amine moieties, so that [LACoCl2] and [LAZnCl2] exhibited trigonal bipyramidal geometries and [LACdBr2] a square pyramidal geometry. [LBCdBr2] has two Cd-containing structures per unit cell, whereby one Cd center adopted a distorted tetrahedral geometry and the other exhibited square bipyramidal geometry. The in situ-generated alkyl derivatives of the synthesized complexes were assessed in the ring-opening polymerization of rac-lactide. Heterotactic polylactides (PLAs) were furnished with all complexes. The [LBZnCl2]/MeLi system produced PLA with a superior heterotactic bias (Pr up to 0.94) at −25 °C. PLAs with wide-ranging polydispersity indices (1.16–2.23) and low molecular weights were produced in all cases, irrespective of the specific M(II) center and ancillary ligand utilized.

Co(ii), Zn(ii), and Cd(ii) complexes supported by bis-pyrazolyl ligands were applied to the ring-opening polymerization of rac-lactide to produce heterotactic polylactides (PLAs) with superior heterotactic bias i.e. Pr up to 0.94 at −25 °C.  相似文献   
87.
88.
Background/AimsThe efficacy of biologics for the treatment of Crohn’s disease (CD) is affected by the drug concentrations. We aimed to evaluate the importance of albumin and globulin which are known to be associated with drug concentrations as prognostic biomarkers in CD.MethodsIn total, 121 pediatric patients with CD who had received anti-tumor necrosis factor (TNF)-α therapy were retrospectively examined between January 2010 and February 2019.ResultsRelapse was observed in 48.8% of patients (59/121). The level of calprotectin (odds ratio, 2.13; p=0.03) and the albumin-to-globulin ratio (AGR) at 1 year after anti-TNF-α therapy (odds ratio, 0.0002; p=0.003) were associated with relapse. The AGR at 1 year after anti-TNF-α therapy was the only factor associated with the time-to-relapse (hazard ratio, 0.02; p<0.001). The optimal AGR cutoff value for the prediction of relapse was 1.47 (area under the curve, 0.916; p<0.001). The median infliximab trough level (TL) was lower in patients with AGRs <1.47 than in those with AGRs ≥1.47. Anti-drug antibody (ADA) concentrations were negatively correlated with the AGR at 1 year of anti-TNF-α therapy (r=–0.413, p=0.032).ConclusionsAGR can be used to predict relapse. Patients with AGRs <1.47 at 1 year after anti-TNF-α therapy are more likely to have low drug TLs and develop ADAs, which increase the possibility of relapse than those with AGRs ≥1.47. Therefore, if the AGR at 1 year after anti-TNF-α therapy is less than 1.47, clinicians should monitor disease activity, assess the TLs of the anti-TNF-α agents, test for ADAs and determine the appropriate therapeutic strategies.  相似文献   
89.
Outcome of hepatic resection for metastatic gastric cancer   总被引:1,自引:0,他引:1  
The role of hepatic resection for metastatic gastric cancer is less well defined due to the tendency of gastric cancer to widely metastasize. The purpose of this study is to examine the beneficial effect of hepatic resection in patients with metastatic gastric cancer. The clinicopathologic features and long-term results of 11 patients who underwent hepatic resection for metastatic gastric cancer from January 1988 to December 1996 at Seoul National University Hospital were analyzed retrospectively. All resected hepatic metastases were solitary lesions. Among eight patients with synchronous hepatic metastases, one patient with early gastric cancer and lymph node metastases (T1N2M1) remained alive for 8 years 6 months after hepatic resection without recurrence. Among three patients with metachronous hepatic metastases, two patients with advanced gastric cancer and lymph node metastases (T3N2MO, T2N1MO at the initial operation, respectively) survived 8 years 6 months and 3 years after hepatic resection, respectively. Median survival times of synchronous and metachronous hepatic metastases were 13.0 and 74.3 months, respectively. In solitary hepatic metastatic lesions from gastric cancer, surgical resection should be considered as one of the treatment options.  相似文献   
90.
OBJECTIVE: To assess the diagnostic efficiency of positron emission tomography with 18-fluorine fluorodeoxyglucose in detecting breast cancer in augmented breasts. DESIGN: Retrospective study. SETTING: University hospital, Korea. SUBJECT: 9 cases or 8 patients with breasts augmented with paraffin or silicone. INTERVENTION: FDG-PET, mammography, and ultrasonography RESULTS: The mammogram detected the breast cancer in only 1 of 3 patients, and ultrasonography gave a false positive result in 1 patient with an augmented breast. In contrast, PET predicted all the cancers and 5/6 benign lesions. 2/3 breast cancers had axillary FDG uptake interpreted as showing metastatic involvement, and in 1 case with cancer with no axillary lymph node involvement there was no FDG uptake in the axilla, which correlated with the pathological finding. CONCLUSIONS: Although the high cost of PET makes its use as a screening test for all patients with augmented breasts unrealistic, it would be the best diagnostic choice if other methods failed.  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