全文获取类型
收费全文 | 1476篇 |
免费 | 80篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 28篇 |
妇产科学 | 44篇 |
基础医学 | 158篇 |
口腔科学 | 17篇 |
临床医学 | 99篇 |
内科学 | 513篇 |
皮肤病学 | 6篇 |
神经病学 | 157篇 |
特种医学 | 58篇 |
外科学 | 164篇 |
综合类 | 3篇 |
一般理论 | 2篇 |
预防医学 | 110篇 |
眼科学 | 31篇 |
药学 | 48篇 |
中国医学 | 6篇 |
肿瘤学 | 121篇 |
出版年
2024年 | 2篇 |
2023年 | 15篇 |
2022年 | 23篇 |
2021年 | 50篇 |
2020年 | 24篇 |
2019年 | 36篇 |
2018年 | 45篇 |
2017年 | 39篇 |
2016年 | 25篇 |
2015年 | 34篇 |
2014年 | 69篇 |
2013年 | 75篇 |
2012年 | 132篇 |
2011年 | 158篇 |
2010年 | 81篇 |
2009年 | 65篇 |
2008年 | 110篇 |
2007年 | 100篇 |
2006年 | 93篇 |
2005年 | 68篇 |
2004年 | 91篇 |
2003年 | 81篇 |
2002年 | 69篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 10篇 |
1998年 | 17篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有1570条查询结果,搜索用时 31 毫秒
91.
Soldevila M Calafell F Andrés AM Yagüe J Helgason A Stefánsson K Bertranpetit J 《Human mutation》2003,22(1):104-105
A total of 616 chromosomes from control individuals of all major continental groups, and six individuals affected by either Creutzfeldt-Jakob disease (CJD) or fatal familial insomnia (FFI), were typed with a new single-reaction protocol method and were also sequenced, with total reproducibility to screen variation at important positions (385A>G: M129V and 655G>A: E219K) in the human prion protein gene (PRNP). We have found, for the first time, that 129V allele is highly represented in some populations from the Americas, and that 129M and 129V are in similar frequencies in Africa. The 129M susceptibility allele was found at high frequencies in Old World populations, very high in the Pacific ( approximately 81%) and up to 93% in Central and East Asia, but at a low frequency (approximately 30%) in Native Americans. The protective 219L allele was restricted to Asian and Pacific populations. Susceptibility alleles exhibit marked geographic differences in frequency, and thus, differences in probability to develop prion diseases. 相似文献
92.
BACKGROUND: Primary carcinomas of the fallopian tube are rare and their preoperative diagnosis is difficult due to the lack of specific symptoms. CASES: We present two tumors diagnosed in women 74 and 77 years old. On examination both patients presented as acute pelvic peritonitis with abdominal pain and tenderness with guarding and rebound, as well as fever and leukocytosis. At surgery, a left tubal carcinoma was found in each patient. Marked inflammatory and purulent reaction involving the uterus, the adnexa, and the pelvic peritoneum, and no abnormalities in the digestive tract were identified. A total hysterectomy with bilateral salpingo-oophorectomy was performed in both patients. CONCLUSION: Carcinoma of the fallopian tube should be considered in the differential diagnosis of pelvic peritonitis, a previously poorly reported clinical presentation. 相似文献
93.
Arós F Cuñat J Loma-Osorio A Torrado E Bosch X Rodríguez JJ López Bescós L Ancillo P Pabón P Heras M Marrugat J;PRIAMHO II Study 《Revista espa?ola de cardiología》2003,56(12):1165-1173
INTRODUCTION AND OBJECTIVES: Hospital registries are useful tools to measure the degree of implementation of new treatments and clinical practice guidelines. PATIENTS AND METHOD: The hospital registry described here was developed in the prospective PRIAMHO II study, which involved a random selection of Spanish hospitals with a coronary intensive care unit and external quality control. This study investigated patients admitted to the coronary care unit with acute myocardial infarction. Demographic and clinical characteristics were recorded, as well as the management, clinical course and survival after 28 days and one year. RESULTS: From May 15 to December 15 2000 we included in the registry 6,221 patients from the 58 hospitals that complied with the quality control requirements (71.6% of all participating hospitals). Acute mortality was 9.6%; 28-day and one-year mortality were 11.4% and 16.5%, respectively. Of the patients with ST elevation-myocardial infarction of less than 12 hours' duration, 71.6% were reperfused and 89.3% received fibrinolysis with a median door-to-needle time of 48 minutes. Ejection fraction was measured in 81% of the patients, and 43% were tested for inducible ischemia. About nine-tenths (91%) of the patients were discharged on least one antiplatelet drug, 56% on a beta blocker, 45% on an ACE inhibitor, and 45% on a lipid-lowering agent, with a coefficient of variation between hospitals greater than 25% for the last three drugs. CONCLUSIONS: The percentage of patients with ST elevation treated with reperfusion should increase, as it probably will thanks to the increasing use of primary angioplasty. The door-to-needle time was longer than the recommended interval. In-hospital risk stratification was good but nonsystematic for the evaluation of ejection fraction, and unsatisfactory for inducible ischemia testing. At discharge the percentages of patients receiving beta blockers, ACE inhibitors and statins were not optimal, and there were wide variations in prescribing practices between hospitals. 相似文献
94.
Background Left ventricular free wall rupture (FWR) usually develops within the first days of acute myocardial infarction (AMI) without warning, but it is uncertain whether a mild pericardial effusion might herald this complication. Methods A 2-dimensional echocardiogram (2DE) was performed in patients with first AMI with (1149) or without (324) ST-segment elevation within 2 days. A second 2DE was performed 2 to 4 days later in 300 patients, 100 with and 200 without an initial mild PE (3-9 mm), and in those with initial moderate-severe PE (≥10 mm) (MSPE) or who developed hypotension or died. Results The first 2DE showed mild PE in 177 patients and MSPE in 51 patients, whereas a late (>2 days) MSPE occurred in 27 with a second routine 2DE, 15 (15%) with and 12 (6%) without initial mild PE (P = .01). Fourteen additional patients, 5 of 77 (6%) with and 9 of 1045 (1%) without initial PE, presented with hypotension and late MSPE (P < .002). Of 92 patients with MSPE, 90 had ST-segment elevation (98%), 60 had tamponade (65%), and 38 died of FWR or were operated on (41%). Results of pericardiocentesis performed in 64 patients were positive in 58, with hemopericardium in 57 (98%). Multivariant analysis showed mild PE on first 2DE and age of >60 years as the only independent predictors of late MSPE or late tamponade. Conclusions Mild PE within the first 2 days in patients aged >60 years with a first ST-segment elevation AMI is associated with an increased risk of late MSPE. Moreover, in this setting MSPE is most frequently associated with hemopericardium, and two thirds of these patients may develop tamponade/FWR. (Am Heart J 2002;144:251-8.) 相似文献
95.
Stroke in renal transplant recipients: epidemiology,predictive risk factors and outcome 总被引:9,自引:0,他引:9
Oliveras A Roquer J Puig JM Rodríguez A Mir M Orfila MA Masramon J Lloveras J 《Clinical transplantation》2003,17(1):1-8
BACKGROUND: Cerebrovascular and cardiovascular diseases are the most important causes of increased morbidity and mortality in patients with end-stage renal disease. Stroke has been widely reported in chronic dialysis patients, but there is scarce information about stroke in renal transplant recipients (RTR), although cerebrovascular events are the most common and potentially life-threatening neurological complications in them. Our aim is to analyze the prevalence, risk factors, etiopathogenia, clinical aspects and outcome of stroke in RTR. METHODS: We analyzed 403 patients who received one or more renal grafts between 1979 and 2000: group A = patients who had stroke (n = 19); group B = those who did not (n = 384). Medical records and pertinent data were compiled. The risk of stroke was studied using univariate and multivariate Cox regression models. RESULTS: prevalence of stroke in RTR was 7.97% at 10 yr. Time elapsed between renal transplantation (RT) and stroke: 49.3 months. Possible risk factors based on the univariate analyses were: diabetic nephropathy (DN) (p < 0.001) and autosomal-dominant-polycystic-kidney-disease (p = 0.049) as original nephropathies, peripheral vascular disease (PVD) (p < 0.001), diabetes mellitus prior to RT (p = 0.005), age older than 40 yr (p = 0.037) and hypertension (p = 0.049). Other analysed risk factors such as gender, renal function, cytomegalovirus infection, hyperlipidemia, hyperuricemia, erythrocytosis or hypertensive donor failed to show any significant predictive value for stroke in these patients. When multivariate analyses were carried out, we found that DN (OR = 4.8; p = 0.010), PVD (OR = 8.2; p < 0.001) and age > 40 yr (OR = 3.3; p = 0.019) were predictive risk factors for stroke. For group A, hypertension was present in all patients, 68.4% had hyperlipidemia and 42.1% reported previous stroke. Cerebral hemorrhage occurred in seven of 19 (36.84%) of the stroke patients, but no subarachnoid hemorrhage occurred in them. Seven of 12 ischemic strokes were atherotrombotic. Considering all strokes, basal ganglia was the predominant localization. The outcome was poor, as nearly half of the patients died in the 3 months following stroke. CONCLUSIONS: Prevalence of stroke in our RTR population was 7.97%. Cerebral hemorrhage appears to be more prevalent in RTR than in general population. More than that, the cerebral hemorrhage rate we found is higher than that reported elsewhere in RTR. The main predictors of stroke were DN, PVD and age. No patient with interstitial nephropathy suffered stroke. Mortality is high in RTR with stroke. 相似文献
96.
Lymphoblastic lymphoma of childhood and the LSA2-L2 protocol: the 30-year experience at Memorial-Sloan-Kettering Cancer Center 总被引:3,自引:0,他引:3
BACKGROUND: Until the 1970s, diffuse lymphoblastic lymphoma (DLBL) was considered incurable. With intensive multidrug regimens, the majority of patients can now be cured. In the current study, the authors present what to their knowledge is the longest follow-up presented to date (median, 20 years for survivors) of the largest group of DLBL patients treated with a single protocol at a single institution. METHODS: Between 1971-1990, a total of 95 consecutive patients (age < 21 years) with DLBL were treated with the LSA(2)-L(2) protocol at the Memorial Sloan-Kettering Cancer Center (MSKCC). Patients with Stage I-II disease were treated for 2 years. In 1980, the protocol was modified and patients with Stage III and IV disease were treated for 3 years. In addition, before the modification, patients with Stage IV disease received a cumulative dose of 15,600 mg/m(2) of cyclophosphamide for 3 years; after 1980, these patients received the same dosage as the other patients (i.e., 8400 mg/m(2) for 2 years). Radiation therapy initially was administered to all patients with bulky disease in the primary tumor site. Until 1977, the dose of radiation was 20-55 grays (Gy); from 1977 to 1989, the dose was 20 Gy. After the fifth year of completion of treatment, all patients were evaluated comprehensively every 2 years. RESULTS: The overall survival (OS) of the patients was 79% with a median follow-up of 20 years. The overall event-free survival (EFS) was 75% (71 of 95 patients). Seventeen patients developed a disease recurrence and 15 died of disease. The OS and EFS rates for patients with Stages I-II disease (n = 8) were 87% and 87%, respectively, and the OS and EFS rates for patients with Stage III disease (n = 41) were 90% and 85%, respectively. The OS and EFS for patients with Stage IVA disease (with bone marrow [BM] involvement of < 25%) (n = 19) were 79% and 73%, respectively, whereas the OS and EFS for patients with Stage IVB disease (BM involvement of > 25%) (n = 27) were 74% and 70%. Of the 29 patients with Stage IV disease who were treated with the original protocol, 7 died of disease (1 of 8 patients with Stage IVA disease and 6 of 21 patients with Stage IVB disease). Of the 17 patients with Stage IV disease who were treated with the modified protocol, 3 died of disease (2 of 11 patients with Stage IVA disease and 1 of 6 patients with Stage IVB disease). Six patients developed secondary malignancies, four of whom died. CONCLUSIONS: Long-term EFS can be achieved in the majority of patients with widely disseminated pediatric DLBL. Chemotherapy alone appears to be sufficient prophylaxis against disease recurrence in the central nervous system. No disease-related or treatment-related deaths were reported to occur > 4.5 years after diagnosis in the current study. 相似文献
97.
Galanthamine is an Amaryllidaceae-type alkaloid with acetylcholinesterase inhibitory activity which is used in the treatment of Alzheimer's disease. The distribution of galanthamine and four other alkaloids in different organs of Narcissus confusus plants, as well as the variations occurring during the ontogenic cycle of this plant species, was studied. The five alkaloids were found to be present in all the organs at every stage, with the exception of haemanthamine in senescent flowers. The highest amount of alkaloids occurred in the bulb at the emerging stage, galanthamine being the most abundant, reaching a concentration of up to 2.5 % referred to dry weight. 相似文献
98.
Tonda R Galán AM Pino M Cirera I Bosch J Hernández MR Ordinas A Escolar G 《Journal of hepatology》2003,39(6):954-959
BACKGROUND/AIMS: There is clinical evidence for the efficacy of activated recombinant factor VII (rFVIIa) in patients with cirrhosis. The exact mechanism of action of rFVIIa in this clinical condition is unknown. We have explored effects of rFVIIa on hemostasis in cirrhotic patients using an in vitro perfusion technique. METHODS: Blood samples were drawn from control donors or from 11 patients previously diagnosed with cirrhosis (seven Child-Pugh B and four Child-Pugh C) and anticoagulated with low molecular weight heparin. rFVIIa was added to blood samples at therapeutic concentrations (0.5 or 1 microg/ml of plasma) and blood was recirculated through annular chambers containing damaged vascular segments. Presence of platelets and fibrin on the subendothelium were morphometrically quantified. RESULTS: Cirrhotic patients showed a diminished platelet interaction with the subendothelium compared to healthy donors (17.3% (9.28-28.88%) vs. 26.16% (19.96-54.5%), P<0.05). After addition of rFVIIa to cirrhotic samples, no differences in platelet covered surface were observed. However, fibrin formation was significantly improved after the addition of rFVIIa (from 51.81% (3.02-86.68%) to 86.94% (30.03-93.18%) and 89.05% (45.65-93.84%), respectively, P<0.05). CONCLUSIONS: Our data confirm a defective interaction of platelets with the subendothelium in cirrhotic patients. rFVIIa improved local fibrin formation at damaged sites and this mechanism could explain the beneficial action of rFVIIa in cirrhotic patients. 相似文献
99.
Sastre-Garriga J Munteis E Río J Pericot I Tintoré M Montalban X 《Multiple sclerosis (Houndmills, Basingstoke, England)》2003,9(3):320-322
BACKGROUND: The use of unconventional therapies is growing in western countries. Few studies on their frequency and rationale among multiple sclerosis (MS) patients have been carried out in Europe. OBJECTIVE: To assess the frequency of use of unconventional therapies among MS patients and to explore associated clinical variables. METHODS: Structured questionnaires were given to 380 consecutive patients seen at two hospital-based MS clinics in Barcelona. Clinical and demographical data were recorded at the same time. The questionnaire inquired about demographical features, education, income, use of unconventional therapies for MS and satisfaction with conventional medicine both in general and specifically in MS. RESULTS: The response rate was 50.78%. Forty-one per cent of patients admitted using unconventional therapies during the previous year. Low levels of satisfaction with conventional medicine in general and for MS, and higher Expanded Disability Status Scale (EDSS) scores (EDSS mean: 4.43 in users versus 3.48 in nonusers) were significantly associated with use of unconventional therapies. CONCLUSION: Use of unconventional therapies is not rare among MS patients, and it is associated with high disability levels and dissatisfaction with conventional medicine. 相似文献
100.
Colomé C Artuch R Vilaseca MA Sierra C Brandi N Lambruschini N Cambra FJ Campistol J 《The American journal of clinical nutrition》2003,77(1):185-188
BACKGROUND: Low serum ubiquinone-10 concentrations have been described in phenylketonuric patients fed natural-protein-restricted diets. Such low concentrations may be related to increased free radical damage. OBJECTIVE: We evaluated the relation between low serum ubiquinone-10 concentrations and other lipophilic antioxidants (tocopherol and retinol), selenium, glutathione peroxidase activity, and malondialdehyde concentrations as a marker of lipid peroxidation. DESIGN: This was a cross-sectional study of 58 patients with phenylketonuria (aged 2-36 y; median: 13 y) under dietary treatment, 58 age-matched control subjects, and 30 children with moderate hyperphenylalaninemia fed unrestricted diets (aged 3-17 y; median: 7.5 y). Serum ubiquinone-10 concentrations were analyzed by HPLC with electrochemical detection. Serum retinol, serum tocopherol, and plasma malondialdehyde were analyzed by HPLC with ultraviolet detection. RESULTS: A significant positive correlation was observed between ubiquinone-10 and tocopherol (r = 0.510, P < 0.001) in the patients with phenylketonuria. After the patients were stratified into 2 groups according to ubiquinone-10 values, significantly lower concentrations of tocopherol were observed in group 1 (low ubiquinone values) than in group 2 (normal ubiquinone values), the hyperphenylalaninemic children, and the control group. Plasma malondialdehyde concentrations were significantly higher in group 1 than in the other groups. No significant differences between groups 1 and 2 were observed in daily intakes of selenium, ascorbate, tocopherol, or retinol. CONCLUSIONS: Plasma lipid peroxidation seems to be increased in phenylketonuria. Low concentrations of ubiquinone-10 could be associated with either excessive tocopherol consumption or high malondialdehyde concentrations in patients with phenylketonuria. 相似文献