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   980篇
  免费   41篇
  国内免费   11篇
耳鼻咽喉   16篇
儿科学   62篇
妇产科学   18篇
基础医学   68篇
口腔科学   18篇
临床医学   91篇
内科学   323篇
皮肤病学   11篇
神经病学   54篇
特种医学   11篇
外科学   254篇
综合类   7篇
预防医学   13篇
眼科学   17篇
药学   33篇
肿瘤学   36篇
  2023年   5篇
  2022年   6篇
  2021年   16篇
  2020年   15篇
  2019年   18篇
  2018年   18篇
  2017年   33篇
  2016年   30篇
  2015年   40篇
  2014年   53篇
  2013年   47篇
  2012年   64篇
  2011年   59篇
  2010年   40篇
  2009年   43篇
  2008年   82篇
  2007年   85篇
  2006年   84篇
  2005年   95篇
  2004年   60篇
  2003年   48篇
  2002年   38篇
  2001年   10篇
  2000年   18篇
  1999年   5篇
  1998年   6篇
  1997年   5篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1989年   1篇
排序方式: 共有1032条查询结果,搜索用时 15 毫秒
51.
BACKGROUND: There are no standard criteria for the timing of drain removal. The objective of this study was to determine whether the macroscopic appearance of chest tube drainage fluid to serosanguineous may be used as a criteria for drain removal. METHODS: 2,359 patients were assessed retrospectively and 80 randomized patients were followed prospectively who underwent cardiac surgery. In both parts of the study, patients were divided into two groups according to the timing of drain removal. Group I consisted of patients whose chest tubes were removed as soon as the macroscopic appearance of the drainage fluid turned to serosanguineous. Group II consisted of patients whose chest tubes were removed at the second postoperative day when the drainage output declined to less than 50 mL in a five-hour period. In the retrospective part, cases of hemodynamically significant pericardial effusion observed within seven days postoperatively were reviewed. In the prospective part, just before the drain removal, the fluid sample hematocrit obtained from the drain lines and patients' blood hematocrit were measured and recorded. Patients were evaluated with echocardiography for pericardial effusion. RESULTS: No statistically significant difference was detected in the frequency of hemodynamically significant pericardial effusion and incidence or amount of pericardial effusion between the two study groups. The drain hematocrit to blood hematocrit ratios before drain removal showed a significant correlation with pericardial effusion.The strength of correlation between the drain hematocrit to blood hematocrit ratios before drain removal and pericardial effusion was also studied using receiver operating characteristic curve, which suggests that a drain hematocrit to blood hematocrit ratio of < or = 0.3 is strongly predictive that pericardial effusion would be absent or mild between the fifth and seventh postoperative days. CONCLUSIONS: It is safe to remove the chest tubes as soon as the macroscopic appearance of the drainage fluid turns to serosanguineous since this practically indicates cessation of active bleeding.  相似文献   
52.
This study was conducted to describe clinical and prognostic aspects of neurological involvement in Behçet's disease (BD). Patients referred for neurological evaluation fulfilled the criteria of the International Study Group for Behçet's Disease. We analyzed disability and survival by the Kaplan-Meier method, using Kurtzke's Extended Disability Status Scale (modified for BD) and the prognostic effect of demographic and clinical factors by Cox regression analysis. We studied 164 patients; of the 107 diagnostic neuroimaging studies: 72.1% showed parenchymal involvement, 11.7% venous sinus thrombosis (VST) and the others were normal. CSF studies were performed in 47 patients; all with inflammatory CSF findings (n=18) had parenchymal involvement. An isolated increase in pressure was compatible with either VST or normal imaging. The final diagnoses were VST (12.2%), neuro-Behçet's syndrome (NBS) (75.6%), isolated optic neuritis (0.6%), psycho-Behçet's syndrome (0.6%), and indefinite (11%). VST and NBS were never diagnosed together. Ten years from onset of BD 45.1% (all NBS) reached a disability level of EDSS 6 or higher, and 95.7±2.1% of the patients were still alive. Having accompanying cerebellar symptoms at onset or a progressive course is unfavorable. Onset with headache or a diagnosis of VST is favorable. Two major neurological diagnoses in BD are NBS and VST. These are distinct in clinical, radiological, and prognostic aspects, hence suggesting a difference in pathogenesis.  相似文献   
53.
The purpose of this study was to compare the outcome and side effects of using the drugs methotrexate and misoprostol, alone or in combination, to induce abortion. A total of 108 subjects who had requested elective termination of pregnancy and medical abortion at 9 weeks gestation or less were randomized into three groups. The first group received 50 mg/m2 intramuscular (IM) methotrexate on day 1 and, if the hCG level had risen by >50% of the initial level on day 4, a second dose was given. They were then followed-up at weekly intervals up to day 21. Group 2 received 800 μg vaginal misoprostol on day 1 and, if ultrasound showed a gestational sac on day 4, they received a repeat dose and were re-examined on day 7. Group 3 received 50 mg/m2 methotrexate intramuscularly followed 3 days later by 800 μg vaginal misoprostol and were re-examined on day 7. Complete abortion occurred in 25 (69%) of the 36 subjects in group 1, 21 (58%) of the 36 subjects in group 2, and 32 (89%) of the 36 subjects in group 3. The complete abortion rate in group 3 was significantly higher than that of both group 1 and group 2 (p <0.05). The incomplete abortion rate was significantly higher in group 2 as compared with both of the other groups (p <0.05). There were significant differences between the mean gestational age of the successful abortions and the failures in group 1 (no abortion occurred at more than 49 days gestation), but not in groups 2 or 3. Vaginal bleeding in subjects who successfully aborted began within 16 ± 4 days in group 1 after the first dose, and within 24 h in 18 (86%) of the 21 subjects in group 2 and 27 (84%) of the 32 subjects in group 3 after the misoprostol dose. The drugs caused no serious or prolonged side effects. The combination of methotrexate and misoprostol is a more effective abortifacient regimen than when either drug is used alone.  相似文献   
54.
Heavy physical work and activity lead to degenerative changes, especially in the lumbar spine. We aimed to find out the occurence of radiographic changes (vertebral osteophytes, heights of lumbar dicsc, concavity index) and abnormalities of the lumbar spine in former professional football (association football or soccer) players according to their specialization (goalkeeper, defender, midfielder, forward) in their past professional sport life. We included 70 male former professional football players and 59 men as the control group. The football players group consisted of 15 defenders (21%), 29 midfielders (41%), 18 forwards (26%) and 8 goalkeepers (12%). Their mean professional football life was 11.04 years and the mean time period after their retirement was 13.87 years. Radiographs of both groups were taken to measure the disc height, concavity index and to determine osteophytes and abnormalities of the lumbar spine. FFbH-R score was assessed for daily activities. The mean FFbH-R score of football players was lower than that of the control group (P = 0.005). The total number of osteophytes in the player group was higher than in the control group (P = 0.001). The mean disc height of L1–L2 in football players was higher than in the control group (P = 0.045). The mean disc height of T12–L1 in goalkeepers was higher than in forward players (P = 0.019). The mean concavity index of L1 in forward players was lower than in defenders (P = 0.018). The mean disc heights of T12–L1 and L2–L3 were both higher in players whose professional sport life was >10 years than in players with ≤10 years (P = 0.018, P = 0.016). The mean disc height of L5–S1 was higher in players who had continued sport activity after retirement (P = 0.025). No statistically significant result was obtained with the rest of the variables. Playing football is heavy work. The decreased height of lumbar discs and the lower value of concavity index of forward players are because the lumbar spine of forward players is loaded more than in the rest of the players. Presented in part orally at Eurospine 2006, İstanbul, Turkey, 25–28 October 2006. Presented in part as poster at XXXVI Scientific Congress of Polish Orthopaedic and Traumatology Society, Katowice, Polland, 28–30 September 2006.  相似文献   
55.
Single-port laparoscopic surgery (SPLS) is a surgical technique with many advantages over conventional laparoscopy. Its range of indications has expanded alongside the development of its unique tools and equipment. We are able to safely perform SPLS with the low-cost glove-port method without need of any specially developed SPLS port or the TriPort Access System. For this study, the files of patients who underwent laparoscopic surgeries performed between the dates of January 2013 and December 2014 at our clinic were reviewed. Umbilical access single-port abdominal surgeries which were performed using glove-port technique were included in the study. Two hundred nineteen patients who underwent SPLS surgery were included in the study. Of these patients, 158 (72.1%) were male and 61 (27.8%) were females. 58.4% of the cases were appendectomies (n = 128), 20% were orchidopexies (n = 44), 8.6% were orchiectomies (n = 19), 5.4% were ovarian cyst excisions (n = 12), 3.6% were varicocelectomies (n = 8), 2.2% were peritoneal dialysis catheter placements (n = 5), and 1.3% were nephroureterectomies (n = 3). In 67 cases (30.4%), Kirschner wire was used to eliminate the need for a second port. The study concludes that glove-port SPLS, which can readily be performed using conventional tools and Kirschner wire rather than expensive specially developed instruments, is a preferable technique because it is reliable, more cost-effective, and results in a scarless recovery.  相似文献   
56.
Clinical and Experimental Medicine - The TIRADS is a scoring system used for the selection of nodules for FNA and classification of the risk of malignancy based on ultrasound characteristics. The...  相似文献   
57.
Cardiac biomarkers such as amino-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTNT) provide information on cardiovascular morbidity and mortality in patients with normal renal function. In a considerable number of chronic haemodialysis patients, both biomarkers - NT-proBNP and cTNT - are elevated despite the absence of cardiac ischaemia. The elevation of cardiac biomarkers in chronic haemodialysis patients is of prognostic value with respect to cardiovascular morbidity and mortality. They provide a useful rationale for the screening of occult cardiac disease and optimization of the dialysis procedure with respect to volume control.  相似文献   
58.
The hepatitis G virus (HGV) and transfusion-transmitted virus (TTV) are recently defined hepatitis viruses that the pathogenic roles in liver diseases are still not clear. It has been well known that some hepatitis virus, such as hepatitis C, might have an affinity to pancreatic islet cells. To investigate the relationship between the newly defined hepatitis viruses and diabetes mellitus (DM), we studied the prevalence of TTV and HGV in a type 2 diabetic patient population. Serum samples of 60 patients with DM and 45 healthy volunteers as control were taken. HGV RNA and TTV DNA was investigated by polymerase chain reaction. HGV was detected in none of diabetic patients (0%) and only one in control group (2.2%). However, TTV DNA was detected in 16 patients with DM (26%) and in five controls (11%). TTV was more prevalent in diabetic patients, but the difference between groups was not statistically significant (p > 0.05). These results revealed that TTV is more common in diabetic patients than in controls. At present, we don't know if this result is only a coincidence or a sign of potential association between TTV and DM. Further studies are certainly needed to elucidate a potential relationship.  相似文献   
59.
This study was designed to measure the frequency at which Turkish patients with cancer resort to complementary and alternative medicine (CAM). A total of 704 patients referred to the Gülhane Military Medical Academy and Ankara Numune Training Hospital between September 2002 and January 2003 were asked about the CAM therapies they used. Of these, 276 patients (39.2%) had used CAM. Gender, marital status, educational status, age, financial status, severity of pain, history of cancer in the family, and their own ideas concerning CAM therapies were found to be correlated with the frequency of resorting to CAM. Resorting to CAM may lead to delayed diagnosis and treatment, adverse drug interactions, treatment withdrawal, and disease progression. Therefore, it is very important to inform patients about these potential dangers. Further studies are needed to clarify the reasons that lead patients to resort to CAM.  相似文献   
60.
This study inquires into neurobiological response to stress and its clinical correlates among adolescents with post-traumatic stress disorder (PTSD). Structural magnetic resonance imaging (MRI) measures of cerebral anatomy were carried out on 23 female adolescents with PTSD related to severe childhood sexual abuse and 21 matched healthy controls. Clinician Administered PTSD Scale for Children and Adolescents, Adolescent Dissociative Experiences Scale, Childhood Trauma Questionnaire, Schedule for Affective Disorders and Schizophrenia for School Age Children, Beck Depression Scale, and a set of neuro-cognitive tests were administered to all participants. Compared to controls, PTSD group bilaterally had smaller amygdala, hippocampus, anterior cingulate, and thinner prefrontal cortex but normal thalamus. Further analyses within the PTSD group suggested an association between symptoms of PTSD and sizes of right brain structures including smaller amygdala but larger hippocampus and anterior cingulate. Thinner right prefrontal cortex and larger right thalamus seemed to be related to denial and response prevention, respectively. Being related to both hemispheres, dissociative amnesia was negatively associated with proportion of the right amygdala to right thalamus and to both left and right prefrontal cortex. Suggesting a neuro-protective effect against traumatic stress at least through adolescence, depersonalization–derealization and identity alteration were correlated with thicker left prefrontal cortex. Unlike the lateralization within PTSD group, correlations between regions of interest were rather symmetrical in controls. The graded response to stress seemed to be aimed at mental protection by lateralization of brain functions and possibly diminished connection between two hemispheres. A Tri-Modal Reaction (T-MR) Model of protection is proposed.  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