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   2063篇
  免费   110篇
  国内免费   10篇
耳鼻咽喉   42篇
儿科学   51篇
妇产科学   69篇
基础医学   249篇
口腔科学   72篇
临床医学   154篇
内科学   466篇
皮肤病学   19篇
神经病学   103篇
特种医学   89篇
外科学   377篇
综合类   38篇
一般理论   1篇
预防医学   92篇
眼科学   29篇
药学   141篇
中国医学   11篇
肿瘤学   180篇
  2024年   3篇
  2023年   20篇
  2022年   47篇
  2021年   97篇
  2020年   53篇
  2019年   73篇
  2018年   100篇
  2017年   59篇
  2016年   65篇
  2015年   64篇
  2014年   102篇
  2013年   127篇
  2012年   165篇
  2011年   185篇
  2010年   113篇
  2009年   80篇
  2008年   103篇
  2007年   115篇
  2006年   99篇
  2005年   81篇
  2004年   78篇
  2003年   70篇
  2002年   62篇
  2001年   17篇
  2000年   15篇
  1999年   13篇
  1998年   13篇
  1997年   12篇
  1996年   20篇
  1995年   9篇
  1994年   14篇
  1993年   3篇
  1992年   15篇
  1991年   11篇
  1990年   9篇
  1989年   4篇
  1988年   3篇
  1987年   5篇
  1986年   5篇
  1982年   3篇
  1981年   5篇
  1979年   5篇
  1977年   2篇
  1973年   2篇
  1972年   2篇
  1971年   3篇
  1968年   4篇
  1967年   7篇
  1966年   4篇
  1946年   2篇
排序方式: 共有2183条查询结果,搜索用时 15 毫秒
41.
AIM: To prospectively study the incidence and the natural history of acute diverticulitis in young patients.METHODS: A total of 207 patients hospitalized at our hospital between January 2000 to February 2005 with the diagnosis of acute diverticulitis were included. Their demographic characteristics, medical history, physical,radiographic and endoscopic findings as well as therapy were recorded. Patients were followed every 6 mo for the first year and later annually.RESULTS: The mean patients' age was 61 (range 27-92) years. Twenty- five patients (12%) were younger than 45 years. Acute diverticulitis was significantly more prevalent among male in the young age group as compared to the older age group (19/25, 76% vs 61/182,33%, respectively, P = 0.0001). Complications occurred more often in the young age group; 32% vs 13%, (P =0.002). During follow-up, 6 patients (28%) remained asymptomatic in the young age group as compared to 87 patients (55%) in the older age group (P = 0.024). As a result, sigmoidectomies were performed twice as often in the young age group (38% vs 13%, P = 0.002).CONCLUSION: Diverticulitis in young patients has a male predominance, a more aggressive course with a higher rate of complications and a higher recurrence rate. An earlier surgical approach might be considered in young patients with acute diverticulitis.  相似文献   
42.
BACKGROUND: Invasive group A streptococcus (GAS) affects approximately 10,500 persons annually; 1 in 5 patients >/=65 years die. In August 2001, CDC investigated a cluster of GAS deaths in a Georgia long-term care facility (LTCF). METHODS: We screened LTCF residents and staff for GAS carriage and conducted a retrospective cohort study among residents. We defined a case as GAS isolation associated with clinical infection. RESULTS: Eight cases were identified (median age: 79 years); 6 (75%) patients died. Carriage was similar in residents (10%) and staff (9%). All isolates among residents and 63% among staff were type emm 77. Risk factors for GAS disease or carriage among residents were receiving skin treatment (relative risk [RR] = 4.0, 95% confidence interval [CI] = 1.9-11.0) and having an infected or colonized roommate (RR = 2.0, 95% CI = 1.10-5.0). No wound care nurse carried GAS. Interventions included education about standardized infection control guidelines and appropriate hand hygiene; carriers were treated with antibiotics. No subsequent GAS cases were identified in the following year. CONCLUSIONS: Transmission of GAS in this outbreak likely occurred during wound care and ended with improved hand hygiene. This investigation highlights additional research and policy needs for control of severe GAS infections among the high-risk LTCF population.  相似文献   
43.
Methotrexate (MTX) is a widely used chemotherapeutic agent; nevertheless, the nephrotoxicity associated with its use has limited its clinical use. Rebamipide (REB) is a gastro-protective agent with diverse promising biological activities. Here, we investigated the renoprotective effects of REB against MTX-induced nephrotoxicity in rats. Male Wistar rats were allocated into four groups: the normal control group, the REB group (100 mg kg−1 day−1, PO, for 12 days), the MTX group (which received a single injection of 20 mg/kg, ip), and the REB + MTX group (which received 100 mg kg−1 day−1 REB for 7 days before and 5 days after being injected with 20 mg/kg MTX). Interestingly, MTX triggered kidney injury, characterized by renal dysfunction along with histopathological alterations. Moreover, increased reactive oxygen species level and inflammatory response were detected in the kidney of MTX-treated rats. However, REB prevented MTX-induced oxidative kidney injury and boosted an antioxidant balance. Mechanistically, REB markedly activated the NRF-2 protein and upregulated the expression of both SIRT-1 and FOXO-3 genes. Additionally, REB administration strongly inhibited the inflammatory response by downregulating both NF-κB-p65 and TLR-4. Finally, the coadministration of REB and MTX activated the mTOR/PI3K/AKT signaling pathway. Simultaneously, REB treatment attenuated the reduction in glomerular size, the widening of the capsular spaces, and the tubular cell damage due to MTX administration. Taken together, these results indicate the potential of REB as adjuvant therapy to prevent nephrotoxicity in patients receiving MTX treatment.  相似文献   
44.
Oral and Maxillofacial Surgery - There is still no definitive consensus about the ideal technique in the treatment of anterior mandibular fractures. Therefore, this study aimed to determine...  相似文献   
45.
BackgroundOptimal antiplatelet inhibition is vital during cerebrovascular stenting procedures, yet no standardized recommendation exists for antithrombotic therapy in these scenarios. Cangrelor is an intravenous P2Y12 inhibitor with a favorable pharmacokinetic profile for use during neuroendovascular stenting.MethodsA retrospective review of all neuroendovascular patients who underwent stenting between 1 January 2019 and 22 March 2020 and were treated with cangrelor was conducted. Thirty-seven patients met inclusion criteria.ResultsAll patients were administered a bolus of 5 mcg/kg of cangrelor followed by a maintenance infusion. Antiplatelet effects of cangrelor were monitored using platelet reactivity units (PRU). Based on the initial PRU, seven patients’ doses were adjusted with subsequent PRUs in or near the goal range of 50–150. One patient experienced an acute intraprocedural occlusion likely related to a subtherapeutic PRU which subsequently resolved with cangrelor dose adjustment and intra-arterial tirofiban administration, and one patient experienced a post-procedure stent occlusion which required a thrombectomy and intra-arterial tirofiban administration. No hemorrhagic complications occurred.DiscussionCangrelor utilization during neuroendovascular stenting with maintenance doses of <2 mcg/kg/min with dose adjustments based on platelet function testing has not been previously described. Cangrelor presents many advantages compared to standard therapy in patients undergoing stent placement related to its pharmacokinetic profile, rapid onset of action, ease of transition to oral P2Y12 antiplatelet agents, and measurability.ConclusionCangrelor is a promising alternative to currently available therapies, especially in patients with a high hemorrhagic risk.  相似文献   
46.
47.
Spinal cord compression due to extramedullary hematopoiesis is a rare manifestation of thalassemia. We present a 28-year-old woman with beta-thalassemia intermedia and progressive paraparesis. She had a thoracic extradural extramedullary mass lesion on MRI. She improved after receiving multiple transfusions. Clinical awareness of this phenomenon with early treatment is essential for a successful outcome.  相似文献   
48.

Background

Patients with chronic pancreatitis are prone to frequent readmissions. The aim of this study is to evaluate the rate and predictors of 30-day readmissions in patients with chronic pancreatitis using the Nationwide Readmission Database (NRD).

Methods

We performed a retrospective analysis of all adult patients with the principal discharge diagnosis of chronic pancreatitis from 2010 through 2014. We excluded patients who died during the hospitalization. Multivariate Cox proportional hazard regression was performed to identify demographic, clinical, and hospital factors that associated with 30-day unplanned readmissions.

Results

During the study period, 25,259 patients had the principal discharge diagnosis of chronic pancreatitis and survived the index hospitalization. Of these, 6477 (26.7%) were readmitted within 30 days. Younger age group, males, length of stay >5 days, admission to a large, metropolitan hospital, and several comorbidities (renal failure, rheumatic disease, chronic anemia, heart failure, depression, drug abuse, psychosis, and diabetes) were independently associated with increased risk of 30-day readmission. ERCP, pancreatic surgery, and obesity were associated with lower risk. The most common reasons for readmissions were acute pancreatitis (30%), chronic pancreatitis (17%), pseudocyst (2%), and abdominal pain (6%).

Conclusions

One in four patients with chronic pancreatitis is readmitted within 30 days (26.7%). Pancreatic disease accounts for at least half of all readmissions. Several baseline comorbidities and characteristics are associated with 30-day readmission risk after index admission. Knowledge of these predictors can help design interventions to target high-risk patients and reduce readmissions and costs of care.  相似文献   
49.
Mineo TC  Ambrogi V  Mineo D  Fabbri A  Fabbrini E  Massoud R 《Chest》2005,127(6):1960-1966
BACKGROUND: In patients with severe emphysema, bone mineral density (BMD) is reduced and the risk of osteoporosis is increased. STUDY OBJECTIVES: To identify the impact of lung volume reduction surgery on BMD. DESIGN: Prospective cohort study. SETTING: University hospital. PATIENTS AND INTERVENTIONS: Forty emphysematous patients, all receiving oral steroid therapy, underwent bilateral lung volume reduction surgery. Thirty similar patients, who refused the operation, followed a standard respiratory rehabilitation program. MEASUREMENTS: All subjects were evaluated pretreatment and 12 months posttreatment for respiratory function, nutritional status, and bone-related biochemical parameters. BMD was assessed by dual-energy radiograph absorptiometry. RESULTS: After surgery, we observed significant improvements in respiratory function (FEV1, + 18.8% [p < 0.01]; residual volume [RV], -29.6% [p < 0.001]; diffusing capacity of the lung for carbon monoxide [Dlco], + 21.6% [p < 0.01]) nutritional parameters (fat-free mass, + 6.0% [p < 0.01]), levels of bone-related hormones (free-testosterone, + 20.5% [p < 0.01]; parathormone, -11.2% [p < 0.01]), bone turnover markers (osteocalcin, -12.7% [p < 0.05]; bone-alkaline-phosphatase, -14.0% [p < 0.05]; beta-crosslaps, -33.6% [p < 0.001]), BMD (lumbar, + 8.8% [p < 0.01]; femoral, + 5.5% [p < 0.01]), and T-score (lumbar, + 21.0% [p < 0.01]; femoral, + 12.4% [p < 0.01]) with reduction in osteoporosis rate (50 to 25%). Nineteen patients who had undergone surgery were able to discontinue treatment with oral steroids. These subjects showed a more significant improvement in BMD (lumbar, + 9.6%; femoral, + 6.8%; p < 0.001) and T-score (lumbar, + 27.3%; femoral, + 14.3%; p < 0.001). The remaining 21 patients who had undergone surgery experienced significant improvement compared to respiratory rehabilitation subjects despite continued therapy with oral steroids (BMD: lumbar, + 4.5% vs -0.7%, respectively [p < 0.01]; femoral, + 2.7% vs -1.1%, respectively [p < 0.05]; T-score: lumbar, + 14 vs -2.1, respectively [p < 0.01]; femoral, + 7.4 vs -2.7, respectively [p < 0.01]). The increase in lumbar BMD was correlated with the surgical reduction of RV (p = 0.02) and with the increase in Dlco (p = 0.01) and fat-free mass (p = 0.01). CONCLUSIONS: Lung volume reduction surgery significantly improves BMD compared to respiratory rehabilitation therapy, even in patients requiring oral steroids. The increase in BMD correlates with RV, Dlco, and fat-free mass, suggesting that the restoration of respiratory dynamics, gas exchange, and nutritional status induces improvement in bone metabolism and mineral content.  相似文献   
50.
Objective:To compare personality traits, attitude toward orthodontic treatment, and pain perception and experience before and after orthodontic treatment.Materials and Methods:One hundred subjects (50 male and 50 female) were included in this study. The mean (SD) age was 17.5 (2.05) years at T1 and 19.15 (2.32) years at T2. The instruments for data collection were questionnaires that included assessment of patients'' personality traits, attitudes toward orthodontic treatment, and pain perception/experience. Subjects completed the questionnaires at two different times: before orthodontic treatment (T1) and after fixed orthodontic treatment (T2). Subjects were treated by fixed orthodontic appliances for an average (SD) period of 18.64 (0.35) months. Paired sample t-test and chi-square test were used to detect any differences.Results:Significant changes in personality traits were detected after orthodontic treatment irrespective of gender. Neuroticism, openness, agreeableness, and conscientiousness scores were improved (P < .001). A positive attitude toward orthodontic treatment was reported at T1 (4.31 [±1.26]) and improved at T2 (3.98 [±1.16]) irrespective of gender (P < .05). The average (SD) expected pain score (T1) was 4.73 (1.88) and the average (SD) experienced pain score (T2) was 4.63 (1.58). Significant difference in the expected and experienced pain scores was not detected (P  =  .11).Conclusions:Personality traits and attitude toward orthodontic treatment improved after orthodontic treatment. Reported actual pain experience during orthodontic treatment was similar to that expected before treatment.  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