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   1181篇
  免费   60篇
  国内免费   10篇
耳鼻咽喉   38篇
儿科学   81篇
妇产科学   48篇
基础医学   81篇
口腔科学   20篇
临床医学   125篇
内科学   351篇
皮肤病学   29篇
神经病学   108篇
特种医学   28篇
外科学   168篇
综合类   8篇
预防医学   28篇
眼科学   45篇
药学   70篇
肿瘤学   23篇
  2024年   1篇
  2023年   15篇
  2022年   20篇
  2021年   27篇
  2020年   28篇
  2019年   19篇
  2018年   37篇
  2017年   23篇
  2016年   36篇
  2015年   37篇
  2014年   53篇
  2013年   49篇
  2012年   83篇
  2011年   76篇
  2010年   44篇
  2009年   44篇
  2008年   61篇
  2007年   97篇
  2006年   105篇
  2005年   105篇
  2004年   70篇
  2003年   68篇
  2002年   59篇
  2001年   26篇
  2000年   21篇
  1999年   17篇
  1998年   7篇
  1997年   4篇
  1996年   4篇
  1995年   3篇
  1994年   7篇
  1993年   3篇
  1992年   2篇
排序方式: 共有1251条查询结果,搜索用时 35 毫秒
71.
OBJECTIVE: To determine the neural substrates of phonic tics in Tourette syndrome (TS) using functional magnetic resonance imaging (fMRI) and compare with a proposed tic-generating network (TGN). PATIENTS: One with TS and one normal control. METHODS: fMRI scans were obtained on the TS patient during which numerous unsuppressed phonic tics occurred and, along with the scanner noise, were recorded on audiotape. The control underwent the same functional MRI sequence but mimicked the tics within predetermined, on-off time blocks. Fuzzy clustering (FC) methods were used to generate the activation maps. RESULTS: The TS patient and control showed fMRI activation in the left middle frontal gyrus and right precentral gyrus. The TS patient also had activity in the caudate nucleus, cingulate gyrus, cuneus, left angular gyrus, left inferior parietal gyrus, and occipital gyri. CONCLUSIONS: fMRI, using an FC analysis, is a viable technique for studying TS patients with phonic tics. These results give further support to the hypothesis of a tic-generating circuit model. Further studies are required to confirm our data.  相似文献   
72.
A 4 1/2-year-old boy with signs and symptoms of spastic paraparesis and dyspnea is presented. Biotinidase deficiency was considered and was confirmed by both urine organic acid analysis and biotinidase activity measurement. The child recovered gradually on biotin therapy. Because other systemic signs and symptoms of the disease might not be present initially or might develop later, biotinidase deficiency should be considered in the differential diagnosis of a child presenting with acute or subacute spastic paraparesis.  相似文献   
73.
Cranial computed tomography in purulent meningitis of childhood   总被引:3,自引:0,他引:3  
The cranial computed tomography (CT) findings of 48 children with purulent meningitis were examined, prospectively, to determine the importance of cranial CT findings on the prognosis of childhood meningitis, in a developing country. The age of children ranged from 2 months to 13 years. Of 48 patients, 29 (60.5%) survived without sequelae, 13 (27%) survived with sequelae, and six (12.5%) died. Cranial CT was normal in 21 (43%) patients of 48 children with meningitis at admission. Abnormal CT findings were detected in 10, 11, and 6 children in the groups of survived without sequelae, survived with sequelae, and deaths, respectively, at admission (p <.05) We found that CT scan results were correlated with neurological signs (p <.05). At least one or more cranial CTs were was re-taken in children in whom the first CT revealed abnormal findings; we did not find a statistically significant difference for the follow-up CT findings between the groups (p >.05). Hydrocephalus and subdural effusion were the commonest abnormal CT findings. In conclusion, our findings showed that cranial CT may safely be used to detect intracranial complications of meningitis in childhood and the ratio of sequelae and death were more common in children with abnormal cranial CT than those of normal cranial CT findings. Additionally, there was a positive correlation between CT scan results and neurological signs.  相似文献   
74.
Ekici S  Saraydin D 《Drug delivery》2004,11(6):381-388
We prepared new ternary interpenetrating polymeric networks (IPN) systems containing chitosan, poly(N-vinylpyrrolidone) and poly(acrylamide) polymers. IPNs were synthesized by radical polymerization of acrylamide monomers in presence of glutaraldehyde (G) and N,N'-methylenebisacrylamide as crosslinkers and the other polymers. These IPNs were named as C-P-A. Glutaraldehyde were used in different concentration to control the network porous of IPNs. Spectroscopic and thermal analyses of these cylindrical shaped IPNs were made with fourier transform infrared spectroscopy analysis, thermogravimetric analysis, and thermomechanical analysis. Swelling studies of IPNs were carried out at pH 1.1 and pH 7.4 at 37°C. The swelling and diffusion parameters of IPNs in these solutions were calculated. Amoxicillin as a bioactive species was entrapped to the IPNs during synthesis. In vitro release kinetics of IPNs were investigated. The experimental data of swelling and release studies suggest clearly that the swelling and release process obeys second-order kinetics. The release of the entrapped bioactive species from IPNs depends on the degree of crosslinking of the polymer and pH of the medium at body temperature. We observed that amoxicillin release at pH 1.1 was higher than at pH 7.4. As a result, IPNs-based chitosan with different cross-linker concentration could be promising candidates for formulation in oral gastrointestinal delivery systems.  相似文献   
75.
The main problem after total laryngectomy is permanent loss of voice. Current methods of vocal rehabilitation after total laryngectomy include development of esophageal speech, use of artificial larynx, tracheoesophageal shunt operations and more recently surgical restoration of the voice with prosthesis. Primary voice restoration using Blom- Singer voice prosthesis after total laryngectomy and pharyngeal myotomy was performed in 187 patients between October 1992 and July 2000. There were 184 male and 3 female patients of average age 63.7 years (range 42-76). Mean follow up period was 62 months. Satisfactory speech was achieved in 156 patients (83.5%). During the follow-up period, we experienced complaints of insufficient voice in 31 (16.5%) patients, due to partial spasm in 17 and total spasm in the pharyngoesophageal segment in 14. Furthermore, 24 (12.8%) patients preferred esophageal speech or electro larynx because of low socioeconomic level. The overall success rate was 70.7%. In this study the results of the surgical technique and prosthesis insertion, as well as the associated complications and socioeconomic levels of the patients, are discussed.  相似文献   
76.
We retrospectively assessed the clinical course and outcome of left-sided endocarditis in pediatric patients to find out the prognostic significance of the presence and size of echocardiographically detected vegetations. Among the children admitted to our institution with endocarditis between January 1987 and October 1999, 16 patients (mean age 9.03 +/- 4.95 years) who met the Duke criteria for the diagnosis of infective endocarditis (IE) were included in this study. Rheumatic valvular disease was the most frequent underlying heart disease (10 patients: 62.5%). Five patients were operated at a mean of 13.9 months before endocarditis, and all had residual defects. Vegetation was detected in 11 cases (69%). Ten patients had major complications (within 2 weeks in 6 patients). Three patients developed congestive heart failure (CHF), six had intracranial and one had lower extremity emboli. Among them four were operated because of complications (CHF: 3 cases, intracranial emboli: 1 case). All the operated cases are doing well. The association between intracranial embolic events and echocardiographically detected vegetations was determined by calculating specificity (40%), sensitivity (100%), positive predictive value (50%), and negative predictive value (100%). No intracranial embolism occurred in patients without vegetations. All vegetations were < or = 6 mm in patients with systemic embolism. There were four deaths, three of which were because of intracranial embolism. This study suggests that intracranial emboli have a major risk of mortality in left-sided endocarditis. The larger size of the vegetation is not a predictor of complications; furthermore, the absence of vegetations predicts that the patient is safe from embolic events. Therefore all patients with left-sided IE should be considered for earlier surgical intervention.  相似文献   
77.
We report the case of a patient with epilepsy who had interictal severe affective aggression, and whose epilepsy significantly improved (but not aggression) after successful temporal lobectomy. Olanzapine significantly improved these aggressive episodes refractory to neurosurgery and previous pharmacological treatments including antipsychotics, anticonvulsants/mood stabilizers and benzodiazepines.  相似文献   
78.
Severe anemia, growth retardation, diabetes mellitus, cardiac disorders, and, infrequently, stroke are well-known complications of thalassemia major. We report a girl, age 7 years, 2 months, with beta-thalassemia major associated with chronic renal failure, diabetes mellitus, and cardiomyopathy in whom a silent stroke was noted during follow-up. She was diagnosed with thalassemia major at age 6 months, chronic renal failure at age 3 years, 3 months, and diabetes mellitus and cardiomyopathy at age 7 years. Although cranial computed tomography was found to be normal at the age of 3 years, 3 months, magnetic resonance imaging showed cerebral infarct in the right frontal region at 7 years, 2 months. A thrombophilic panel revealed increased factor VIII and decreased protein C concentrations. She died from disseminated intravascular coagulation at age 7 years, 9 months. We did not record any clinical findings of stroke during her follow-up. We think that diabetes mellitus, dilated cardiomyopathy, and increased factor VIII and decreased protein C concentrations led to the occurrence of cerebral infarct. In conclusion, we emphasize that children with thalassemia major should be monitored closely for stroke. We also suggest that stroke can show a silent progression in severely affected children, as in our case.  相似文献   
79.
An 11-year-old male was admitted with inability to walk and speech abnormality. He was diagnosed with subacute sclerosing panencephalitis on the basis of clinical and laboratory findings. Therapy with inosiplex (100 mg/kg/day orally) plus intrathecal interferon-alpha (3 million units/dose twice per week) and ribavirin (15 mg/kg/day orally) was initiated. Ribavirin was given orally because of a lack of parenteral form in our country. During follow-up, he complained about fever and widespread body pains after intrathecal therapy. On the sixth month of follow-up, generalized tonic-clonic seizures, associated with high fever, and lasting approximately 1-2 minutes occurred about 6 hours after giving interferon-alpha. Four days after the first seizures, a similar seizure attack reoccurred after intrathecal IFN-alpha. An antiepileptic agent was not administered because electroencephalogram results did not indicate epileptic discharges. At the current time, he is in the ninth month of follow-up and remains seizure-free. In conclusion, our case demonstrated that standard dose intrathecal interferon-alpha might cause seizures in children. We think that this unfortunate condition was more common in subacute sclerosing panencephalitis children treated with intrathecal interferon-alpha.  相似文献   
80.
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