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   1035篇
  免费   45篇
  国内免费   4篇
耳鼻咽喉   19篇
儿科学   39篇
妇产科学   65篇
基础医学   81篇
口腔科学   37篇
临床医学   66篇
内科学   259篇
皮肤病学   8篇
神经病学   51篇
特种医学   102篇
外科学   220篇
综合类   16篇
预防医学   28篇
眼科学   19篇
药学   34篇
中国医学   4篇
肿瘤学   36篇
  2023年   5篇
  2022年   12篇
  2021年   26篇
  2020年   17篇
  2019年   16篇
  2018年   31篇
  2017年   24篇
  2016年   43篇
  2015年   57篇
  2014年   57篇
  2013年   64篇
  2012年   72篇
  2011年   58篇
  2010年   47篇
  2009年   37篇
  2008年   55篇
  2007年   71篇
  2006年   69篇
  2005年   68篇
  2004年   66篇
  2003年   82篇
  2002年   49篇
  2001年   7篇
  2000年   3篇
  1999年   2篇
  1998年   3篇
  1997年   9篇
  1996年   2篇
  1995年   6篇
  1994年   2篇
  1993年   3篇
  1992年   2篇
  1991年   2篇
  1990年   1篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1983年   1篇
  1976年   2篇
  1974年   2篇
  1970年   2篇
  1968年   1篇
  1967年   1篇
  1966年   1篇
  1965年   1篇
  1964年   1篇
  1959年   1篇
排序方式: 共有1084条查询结果,搜索用时 15 毫秒
1.
Background/purpose: The localized or generalized skin thickness detected on mammography may reflect an underlying pathology of breast or a systemic disease involving the skin. The aim of this report is to describe the range of normal breast skin thickness in women using a film-screen mammographic technique.
Methods: Measurement of the mammographic skin thickness over different parts of the breast was performed in 144 women who had normal findings in a combined mammographic and ultrasonographic examination. Patients were grouped as premenopause, postmenopause and surgical menopause who were under continuous oestrogen treatment. The skin thickness in four regions (superior, inferior, medial, lateral) of both breasts was compared, and their relations with age, breast size, menopausal and hormonal status were investigated. The interobserver reliability was tested in a small subgroup of patients.
Results: Interobserver agreement was good for all measurements. The range of normal breast skin thickness was between 0.50 and 3.10 mm. There were no differences in skin thickness between the corresponding regions of the breasts, with significant differences between the regions in the same breast. While breast size increased with age, skin thickness decreased in all regions.
Conclusion: The breast size, age, regional variations and hormonal status of the patients should be considered when defining the normal range of skin thickness in mammographic examinations. We assume that upper limit of mammographic skin thickness should be set as 3.0 mm, regardless of the focal spot size and film-focus distance.  相似文献   
2.
Background :
The aim of this study was to examine nuclear p53 overexpression in transitional cell carcinoma of the bladder, adenocarcinoma of the prostate, and renal cell carcinoma.
Methods :
Forty-four pathologic specimens from 39 bladder cancer patients, 41 prostatic adenocarcinoma, and 39 renal cell carcinoma specimens were analyzed immunohistochemically with D07 monoclonal antibody to detect the expression of the mutant p53 gene. Overexpression was said to occur when the number of positively-stained tumor nuclei were≥ 10% in each specimen. p53 overexpression was correlated with the clinical and histopathological features of these cancers.
Results :
Nuclear p53 overexpression occurred in 18.2% of transitional cell bladder cancer specimens, 12.2% of prostate cancer specimens, and 17.9% of renal cell cancer specimens. Statistical analyses showed that grade, vascular invasion, and necrosis in bladder cancer, a high Gleason score in prostate cancer, and the 1-year mortality rate in renal cancer were significantly related with p53 nuclear overexpression (P<0.05).
Conclusion :
Using the D07 monoclonal antibody, nuclear p53 overexpression is relatively uncommon in urologic malignancies, and moderately correlates with several histopathological and clinical features of urologic malignancies.  相似文献   
3.
The heels of 23 patients who were diagnosed with unilateral/bilateral plantar fasciitis were evaluated via ultrasonography and compared with their asymptomatic feet and a control group of 23 people. Plantar fascial thickness, echogenity, and heel pad thickness were evaluated, and the results were statistically analyzed. For symptomatic feet, increased thickness of the fascia and reduced echogenity were constant ultrasonographic findings (mean, 4.79 mm for symptomatic feet; 2.17 mm for control group, P < .05). No significant difference was found between heel pads of the diseased and healthy feet (mean, 12.96 mm for symptomatic feet; 13.10 mm for control group; P > .05). Ultrasonography seems to be a valuable, noninvasive diagnostic tool for the evaluation of plantar fasciitis.  相似文献   
4.
Giving adequate information about febrile convulsion and its prognosis would be helpful in alleviating parental stress, and would contribute to decrease in the morbidity of febrile convulsion. In this study, the knowledge level of parents on taking body temperature, and decreasing high fever, their attitudes during febrile convulsion and the impact of febrile convulsion on parents are evaluated. One hundred seventy-four parents of 132 children with FC were enrolled in the study. Twenty-seven per cent of parents had no thermometer at home, 32.8% of them did not know how to take a temperature, 72.2% of them did not know the minimum range of increased body temperature, and 69.5% of them did not know how to decrease the increased body temperature. Thirty-six percent of parents recognised the convulsions when their children suffered from them, the others assumed the convulsion were fainting spells (6.9%), near death state (38.5%) and suffocation (18.4%). Thirty-six per cent of parents brought their children to the hospital without doing anything themselves. Most parents (91.4%) had a fear of a recurrence of febrile convulsion in their children. Seventy-four per cent of parents complained of insomia, 24.3% parents had dyspeptic symptoms even 14 parents had weight loss due to dyspepsia.  相似文献   
5.
The aim of this prospective study was to determine the diagnostic value of Tc-99m MDP scintimammography (SMG) for the detection of breast cancer in patients with breast masses and to compare the results with Tc-99m MIBI scintimammography. Twenty patients, categorized as suspicious, positive or benign for breast cancer according to the mammographic findings were included in the study. Dual phase Tc-99m MIBI and Tc-99m MDP SMG were performed in the prone lateral position within 5 days of each other. Although early and late Tc-99m MIBI SMG showed equal (90.4%) sensitivity, the specificity of late Tc-99m MIBI (87.5%) was found superior to early (62.5%) imaging. The overall sensitivity and specificity of early Tc-99m MDP SMG were 71.4% and 62.5%, respectively. Although late Tc-99m MDP imaging showed 100% specificity, its sensitivity was only 23.8%. In the patients with palpable masses, both early Tc-99m MDP and Tc-99m MIBI showed equal sensitivity (100%), but the sensitivity of early Tc-99m MIBI (37.5%) was found slightly higher than Tc-99m MDP (25.0%) for nonpalpable breast lesions. The sensitivity of Tc-99m MIBI and Tc-99m MDP SMG in detecting metastatic axillary involvement was 66.6% and 50%, respectively. High sensitivity and specificity together with its low cost, easy availability and the possibility of detecting bone metastases seems to make Tc-99m MDP a contributive agent in the evaluation of breast lesions as an alternative to Tc-99m MIBI.  相似文献   
6.
Ozbek MN, Senée V, Aydemir S, Kotan LD, Mungan NO, Yuksel B, Julier C, Topaloglu AK. Wolcott–Rallison syndrome due to the same mutation (W522X) in EIF2AK3 in two unrelated families and review of the literature. Wolcott‐Rallison syndrome (WRS) is a rare autosomal recessive disorder characterized by an early‐infancy‐onset diabetes mellitus associated with a variety of multisystemic clinical manifestations. Here, we present six patients with WRS, carrying the same homozygous mutation (EIF2AK3‐W522X), from two unrelated Turkish families. This is the largest series of patients with the same mutation for this rare syndrome. In this communication we compare clinical features of these six patients with the other 34 patients who have been reported to date, and review the clinical features of WRS. All WRS patients presented first with symptoms of insulin dependent diabetes mellitus, with a mean age at onset of 2 months. All patients had skeletal dysplasia or early signs of it, and growth retardation. Many of the patients with WRS have been reported to have developmental delay, mental retardation, and learning difficulties; in contrast, none of our patients showed abnormal development at age up to 30 months. Acute attacks of hepatic failure were reported in 23 cases out of 37 patients; in 15 of those 23 cases an acute attack of renal failure accompanied the liver failure. Exocrine pancreatic deficiency has been reported in only four cases other than our four patients. Central hypothyroidism was observed in six of 28 cases. We propose that central hypothyroidism is not a component of WRS, but rather a reflection of euthyroid sick syndrome. Four of our patients experienced severe neutropenia, compared to only five of the 27 other cases, suggesting that the W522X mutation may be specifically associated with neutropenia. Other than the consistent features of diabetes mellitus and epiphyseal dysplasia, WRS patients are otherwise characterized by extensive phenotypic variability that correlates poorly to genotype.  相似文献   
7.

Objective

We sought to determine whether meconium-stained amniotic fluid is based on chronic hypoxia or not? In case of chronic hypoxia, higher red blood cell (Rbc) count and/or total hemoglobin levels (Hgb) and/or higher fetal hemoglobin (HbF) and/or lower adult hemoglobin (HbA) levels were expected when compared with controls.

Design

Case–control study.

Setting

Obstetric unit of a tertiary ministry of health hospital.

Sample

Fifty singleton pregnancies with meconium-stained amniotic fluid and 50 singleton pregnancies with clear amniotic fluid at all stages of labor.

Methods

Umbilical cord blood samples were collected for determination of total blood parameters and hemoglobin electrophoresis.

Main outcome measures

Red blood cell count, total hemoglobin, fetal and adult hemoglobin contents (HbF and HbA).

Results

Red blood cell count, total hemoglobin, fetal hemoglobin (HbF) and adult hemoglobin (HbA) contents were not different between meconium stained and clear amniotic fluid groups.

Conclusion

These results suggest that meconium passage may not be associated with chronic fetal hypoxia as demonstrated by similar red blood cell count, total hemoglobin values and fetal hemoglobin (HbF) and adult hemoglobin (HbA) contents.
  相似文献   
8.
OBJECTIVES: Congenital anomalies and intrauterine fetal death (IUFD) are frequent problems in pregnancies. Detection of the etiology is important for genetic counseling, and presenting the geographic distribution of the causes of disorders is necessary for a national policy on precautions. Here, we report the findings of terminated fetuses due to IUFD and congenital anomalies in Turkish population. METHODS: Physical examinations of fetuses and genetic evaluations of families were done. X-ray studies and autopsy were done in the event of necessity. Findings of these studies were combined with prenatal ultrasound results. All cases were classified according to ICD-10. RESULTS: The number of fetuses examined was 2407. Out of these, 1268 fetuses had congenital anomalies. Neurologic anomalies and musculoskeletal system malformations were the most frequent disorders. Specific diagnoses were possible in 64% of all multiple malformation syndromes.Abnormal findings were detected in 18.8% of IUFD fetuses. Nine percent had congenital anomalies and 5.2% had cord complications. The percentage of twins and triplets was 7.5% and 13% of them had anomalies. CONCLUSION: Postmortem evaluation is useful to detect findings necessary for genetic counseling. Our protocol is effective especially in fetuses with congenital anomalies but it can detect only some of the fetal reasons in IUFD cases. A more detailed protocol is needed to investigate IUFD cases.  相似文献   
9.
An 83‐year‐old male patient presented to the outpatient clinic with complaint of swelling at right antecubital area. Ultrasonographic examination of the right upper extremity revealed a mass lesion within the right cephalic vein, which was consistent with thrombus. A computed tomography (CT) venography showed contrast enhancement in cephalic vein at distal arm and an aneurysmatic thrombus area displaying regular borders with a size of 28*30 mm; there was no contrast enhancement at more proximal levels at the cephalic vein.  相似文献   
10.
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