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   955篇
  免费   35篇
  国内免费   9篇
耳鼻咽喉   18篇
儿科学   54篇
妇产科学   19篇
基础医学   55篇
口腔科学   24篇
临床医学   97篇
内科学   304篇
皮肤病学   20篇
神经病学   61篇
特种医学   17篇
外科学   240篇
综合类   6篇
预防医学   13篇
眼科学   21篇
药学   32篇
中国医学   1篇
肿瘤学   17篇
  2023年   7篇
  2022年   6篇
  2021年   11篇
  2020年   14篇
  2019年   18篇
  2018年   15篇
  2017年   31篇
  2016年   28篇
  2015年   31篇
  2014年   48篇
  2013年   46篇
  2012年   62篇
  2011年   57篇
  2010年   36篇
  2009年   42篇
  2008年   82篇
  2007年   94篇
  2006年   91篇
  2005年   96篇
  2004年   64篇
  2003年   47篇
  2002年   37篇
  2001年   7篇
  2000年   7篇
  1999年   3篇
  1998年   5篇
  1997年   4篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
排序方式: 共有999条查询结果,搜索用时 15 毫秒
101.
Renal cell carcinoma (RCC) has a high metastatic potential due to its hematogen and vascular features. It metastasizes frequently to the lungs, the bones, the liver, the lymph nodes and the brain. Metastasis of RCC to the head and neck region is quite rare. In this case report, two RCC patients with head and neck metastases are presented: one occurring after 5 years and the other occurring 17 years after diagnosis.  相似文献   
102.
BACKGROUND: The aim of this study was to determine whether prophylactic use of calcium dobesilate (CD) can improve venous function after saphenous vein harvest in coronary artery bypass graft (CABG). MATERIALS AND METHODS: A total of 100 patients who underwent elective CABG were divided into four equal groups. In Group A, the greater saphenous vein (GSV) was harvested below the knee and, in Group B, through the knee till the groin. These patients remained untreated. Group C received CD in a dosage of 1500 mg po daily after the GSV was harvested below the knee. Group D received same dosage of CD after the GSV was harvested through the knee till the groin. Venous function of ipsilateral leg was evaluated clinically and by Doppler ultrasonography in the postoperative first week and second month. RESULTS: Clinical findings of venous insufficiency were observed with a similar rate between groups at both early and late periods. In Groups A and B, after 2 months, flow velocities decreased and reflux periods increased significantly. In groups C and D, treatment with CD for 2 months after saphenectomy resulted in a significant increase in flow velocities and a significant decrease in reflux periods. Patients in Groups B and D have significantly more impaired venous functions. CONCLUSION: Saphenectomy results in ipsilateral leg venous dysfunction, which seems to be unrelated to leg swelling and to be more prominent in patients with high-level saphenectomy. In addition, to be careful about the restriction of the saphenectomy procedure into the most appropriate level, prophylactic use of CD can prevent this deterioration when it was added to varice socks.  相似文献   
103.

AIMS

Pharmacokinetic (PK) and pharmacodynamic (PD) monitoring strategies and clinical outcome were evaluated in enteric-coated mycophenolate sodium (EC-MPS)-treated renal allograft recipients.

METHODS

PK [mycophenolic acid (MPA)] and PD [inosine monophosphate dehydrogenase (IMPDH) activity] data were analysed in 66 EC-MPS and ciclosporin A (CsA)-treated renal allograft recipients. Adverse events were considered in a follow-up period of 12 weeks.

RESULTS

Analyses confirmed a limited sampling strategy (LSS) consisting of PK and PD data at predose, 1, 2, 3 and 4 h after oral intake as an appropriate sampling method (MPA r2= 0.812; IMPDH r2= 0.833). MPA AUC0–12 of patients with early biopsy-proven acute rejection was significantly lower compared with patients without a rejection (median MPA AUC0–12 28 µg*h ml−1 (7–45) vs. 40 µg*h ml−1 (16–130), P < 0.01), MPA AUC0–12 of patients with recurrent infections was significantly higher compared with patients without infections (median MPA AUC0–12 65 µg*h ml−1 (range 37–130) vs. 37 µg*h ml−1 (range 7–120), P < 0.005). Low 12-h IMPDH enzyme activity curve (AEC0–12) was associated with an increased frequency of gastrointestinal side-effects (median IMPDH AEC0–12 43 nmol*h mg−1 protein h−1[range 12–67) vs. 75 nmol*h mg−1 protein h−1 (range 15–371), P < 0.01].

CONCLUSIONS

Despite highly variable absorption data, an appropriate LSS might be estimated by MPA AUC0–4 and IMPDH AEC0–4 in renal transplant patients treated with EC-MPS and CsA. Regarding adverse events, the suggested MPA-target AUC0–12 from 30 to 60 µg*h ml−1 seems to be appropriate in renal allograft recipients.  相似文献   
104.
The maxillofacial region is affected by a greater number of cysts than any other part of the body. In this study, 90 odontogenic cysts were collected from 90 patients over a five-year period. Patients with radicular cysts, dentigerous cysts and odontogenic keratocysts were further analyzed with regard to age, sex and anatomical distribution. Using the histological classification of the World Health Organization, 53 cases (59%) were classified as radicular cysts, 24 (27%) as keratocysts and 13 (14%) as dentigerous cysts. Radicular cysts occurred most frequently in the anterior region of the maxilla, odontogenic keratocysts in the ramus and angular region of the mandible, and dentigerous cysts in the mandible. No recurrences were observed during the limited follow-up period.  相似文献   
105.
Summary An individual's iron status may affect the response rate achieved with the use of interferon (IFN) as therapy for chronic viral hepatitis. A total of 27 patients with chronic hepatitis B viral infection, who had elevated serum ferritin levels, were randomized to receive either IFN 5 MU, three times weekly by subcutaneous injection alone ( n = 14) or in combination with cycles of deferoxamine at a dose of 80 mg kg-1 per cycle ( n = 13) administered over 3 consecutive days, to reduce their iron and maintain a serum ferritin level less than 250 ng ml-1. All deferoxamine-treated patients were on a low iron-containing diet. An IFN response was defined as a normalization of the serum alanine aminotransferase (ALT) level and seroconversion from hepatitis B e antigen (HBeAg) positivity to hepatitis B e antibody (HBeAb) positivity. The deferoxamine-treated group experienced a reduction in their serum ferritin level to 226 ± 73 ng ml-1 as a result of the deferoxamine treatment. Six of the 13 (46%) deferoxamine-treated patients and two of the 14 (14%) control patients normalized their ALT levels. Seven of the 13 (54%) deferoxamine but only 14% of the IFN-treated group seroconverted to HBeAb positivity. A greater rate of histological improvement and loss of hepatitis B virus (HBV) DNA was seen in the deferoxamine-treated group. Two of the deferoxamine-treated patients were treated only once, two were treated twice, seven were treated three times and two were treated four times to achieve a ferritin level below 250 ng ml-1.  相似文献   
106.
BACKGROUND: The population of incident dialysis patients is progressively ageing and dialysis outcome is particularly poor in the elderly. There is little documentation whether late referral is more frequent in the very elderly (> or =75 years) as compared with non-elderly patients and whether it contributes, at least in part, to their particularly poor outcome. METHODS: In a retrospective single center study we assessed all consecutive patients (n = 254) who had been admitted to haemodialysis between 1998 and 2001. Outcome in relation to the interval between the time of referral and start of dialysis was compared in very elderly and non-elderly patients. According to a previous analysis in our center major adverse outcome is seen in patients referred < or =8 weeks before the start of dialysis. For the present study this time interval was therefore operationally defined as 'late referral'. RESULTS: Expectedly 1 year after start of dialysis mortality was higher (31%) in the very elderly compared with younger patients (19%). The interval between referral and first dialysis was less in patients > or =75 years (median interval 3.5 weeks) compared with patients <75 years (median 20.5 weeks; P = 0.007). The difference in 1 year mortality between timely (>8 weeks) vs late (< or =8 weeks) referral, however, was as high in the very elderly (42% vs 16%) as in the younger patients (34% vs 9%). The relative risk of death conferred by late referral was also not significantly different in the very elderly (RR 1.80) compared with the younger (RR 2.32) patient. Using multivariate analysis timing of referral proves to be an independent factor with regard to the outcome and time of survival. CONCLUSIONS: We conclude that late referral is more frequent in the very elderly. Although the relative risk of death conferred by late referral is similar in the very elderly and non-elderly, due to higher frequency of late referral it accounts for a large proportion of excess mortality in the very elderly.  相似文献   
107.
BACKGROUND: Gastrointestinal (GI) complications are one of the serious complications of cardiac surgery. Although rarely seen, they cause major morbidity and mortality. The aim of the present study was to retrospectively analyze the risk factors acting on the GI complications seen after cardiac operations performed under cardiopulmonary bypass. METHOD: The present study was designed to retrospectively evaluate 13,544 patients who underwent cardiac surgery under cardiopulmonary bypass, between 1988 and 2004 in the authors' clinic. RESULTS: The overall mortality was 346 (2.55%) of 13,544 patients. GI complications developed in 128 patients (0.94%). Among those, 18 (14.1%) died because of GI complications, the most common of which was bleeding. Mesenteric ischemia had the highest case-fatality rate at 71.4%. Valve surgery, concomitant valve and coronary artery bypass grafting surgery, preoperative chronic renal dysfunction, postoperative acute renal failure, deep sternal infection, prolonged ventilation, need for intra-aortic balloon pump and ejection fraction less than 30% were found to be risk factors acting on GI complications. CONCLUSION: GI complications remain a significant concern after cardiac surgery under cardiopulmonary bypass. Higher-risk patients can be identified and treated prophylactically and in the postoperative period.  相似文献   
108.
BACKGROUND: It has been hypothesized that in renal failure, exogenous glycation compounds from food accumulate and play a major pathogenetic role when renal excretion is impaired. METHODS: To address this, a diet containing a defined amount of the lysine Amadori product (AP) lactuloselysine was used. Plasma concentrations and cumulative urinary excretion of AP were assessed in 16 healthy subjects, 12 renal failure patients and 6 continuous ambulatory peitoneal dialysis (CAPD) patients. Amadori product was measured as furosine using reverse phase high performance liquid chromatography (RP-HPLC) after acid hydrolysis. RESULTS: A diet low in glycation compounds significantly decreased excretion of APs in healthy subjects. In healthy individuals, ingestion of lactuloselysine bound to food proteins caused only a minor acute increase (8.24+/-1.11 mg/day, 2% of the administered dose) of AP excretion in the urine; in patients with renal failure not yet on dialysis, the increase in AP excretion in the urine was significantly less (4.0+/-0.51 mg/day) and the same was true in CAPD patients (0.21+/-0.09 mg/day). The plasma concentration of total APs, i.e. the sum of APs as free amino acids and residues bound to plasma proteins, did not change in any of the three groups, however. CONCLUSION: Dietary APs do not accumulate in the blood even in advanced renal failure. The amount of APs measured as furosine excreted in the urine is significantly less, however, in renal failure and CAPD patients compared with healthy subjects. Although the findings exclude accumulation of lactuloselysine in renal failure, they do not generally exclude accumulation of other food-derived advanced glycation end products (AGEs).  相似文献   
109.
Infestation with fasciola hepatica is not often seen in humans. Only a few cases have been reported previously, while in our clinic only three cases have been observed in 20 years. All three cases (two males aged 35 and 40 and a 45-year-old female) were operated on with the possible diagnosis of choledocholithiasis, and parasites were later incidentally discovered at operation. In recent years praziquantel has been used with a high rate of success in the medical treatment of this disease. We have also prescribed praziquantel for our last two cases in order to prevent recurrence and to kill any parasites that might still remain after the operation. In the postoperative follow-up a complete cure was observed in all cases.  相似文献   
110.
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