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   1229篇
  免费   56篇
  国内免费   11篇
耳鼻咽喉   7篇
儿科学   70篇
妇产科学   18篇
基础医学   84篇
口腔科学   28篇
临床医学   101篇
内科学   279篇
皮肤病学   22篇
神经病学   67篇
特种医学   72篇
外国民族医学   1篇
外科学   205篇
综合类   21篇
一般理论   3篇
预防医学   183篇
眼科学   14篇
药学   54篇
中国医学   6篇
肿瘤学   61篇
  2023年   19篇
  2022年   50篇
  2021年   67篇
  2020年   31篇
  2019年   39篇
  2018年   38篇
  2017年   32篇
  2016年   36篇
  2015年   35篇
  2014年   44篇
  2013年   55篇
  2012年   78篇
  2011年   49篇
  2010年   47篇
  2009年   50篇
  2008年   57篇
  2007年   37篇
  2006年   58篇
  2005年   48篇
  2004年   47篇
  2003年   39篇
  2002年   26篇
  2001年   24篇
  2000年   17篇
  1999年   25篇
  1997年   4篇
  1995年   4篇
  1992年   11篇
  1991年   14篇
  1990年   20篇
  1989年   27篇
  1988年   25篇
  1987年   22篇
  1986年   17篇
  1985年   17篇
  1984年   10篇
  1983年   4篇
  1982年   6篇
  1981年   3篇
  1979年   11篇
  1977年   4篇
  1976年   3篇
  1975年   8篇
  1974年   5篇
  1973年   5篇
  1972年   4篇
  1971年   3篇
  1970年   2篇
  1966年   3篇
  1965年   5篇
排序方式: 共有1296条查询结果,搜索用时 15 毫秒
31.
A 5-month-old female was referred to the paediatric surgery clinic with a neck swelling in the right supra-clavicular region. This was thought clinically to be cystic hygroma. Pathology showed an ectopic salivary gland. This should be added to the list of differential diagnoses of neck swelling in childhood.  相似文献   
32.
Congenital esophageal stenosis (CES) is suspected by a fixed intrinsic narrowing of the esophagus that affects the normal swallowing mechanism. The diagnosis is only confirmed by histopathologic picture, which may show fibromuscular disease (FMD) or tracheobronchial remnants (TBR). The latter involves ciliated pseudo stratified columnar epithelium, seromucous glands or cartilage each alone or in combination. The aim of this study is to document the usefulness of histologic picture of surgical specimens obtained from the lower esophageal pouch (LEP) during primary repair in detecting cases of CES associated with esophageal atresia (EA) with or without tracheoesophageal fistula (TEF). Over an 8-year period, 57 consecutive cases operated upon for EA with or without TEF were subjected for histologic examination of surgical specimens obtained from the tip of the LEP. Cases that histologically showed FMD or TBR were included. The usefulness of this histologic picture as a diagnostic and therapeutic aid is assessed. Methods of treatment and outcome were also reviewed. Eight patients out of 57 (14%) had a histologic picture suggestive of CES, two with FMD, four with TBR without cartilage and two with cartilage. Out of 57 patients, 23 developed strictures, six of them had positive biopsies suggestive of CES. One patient with TBR without cartilage did not have stricture. Another case of pure atresia had LEP resection and gastric pull up showed cartilage involving the whole lower esophagus. Excluding the case of pure EA with gastric pull up, all patients suffered from feeding problems and recurrent aspiration. Fluoroscopic barium studies showed late onset minor dysmotility in five patients and late onset major dysmotility in two. All cases studied showed significant gastro-esophageal reflux (GER). Stricture was seen at the anastomotic site extending distally in the two fibromuscular cases and one case with cartilage, at the anastomotic site in three cases with TBR without cartilage. Anti reflux surgical procedures were performed in four patients without benefit in two patients with major dysmotility. Dilatation was successful in the three patients with TBR without cartilage. One patient with cartilage had resection of the anastomotic site and required frequent dilatations and is now doing well. A case of FMD did not improve after frequent dilatations and myotomy together with Nissen’s fundoplication and required resection while the other case of FMD responded partially to dilatations. Cartilage in cases of CES requires surgical resection. Those with TBR without cartilage may not develop stricture. If stricture develops, it responds well to dilatation and patients have good clinical outcomes. Unlike isolated CES, GER is a significant feature in CES with EA. Anti reflux procedures should be avoided before definitive surgery for the stricture and if necessary a partial wrap with gastrostomy is recommended. CES should be considered in the etiology of anastomotic stricture. Taking a surgical specimen routinely from the tip of the LEP during primary esophageal repair for histologic studies is highly recommended.  相似文献   
33.
Stature estimation based on hand length and foot length   总被引:1,自引:0,他引:1  
This study was carried out to estimate the relationship between hand length, foot length and stature using multiple linear regression analyses based on a sample of male and female adult Turks residing in Adana. Measurements of hand length, foot length and stature were taken from 155 adult Turks (80 male, 75 female) aged 17-23 years. The participants were students of the Medical Faculty of Cukurova University. A multiple linear regression model was fitted to the observed data. Stature was taken as the response or dependent variable, hand length and foot length were taken as explanatory variables or regressors. All possible (simple and multiple) linear regression models for each of males, females and both genders together were tested for the best model. The multiple linear regression model for both genders together was found to be the best model with the highest values for the coefficients of determination R2 = 0.861 and R2adjusted = 0.859, and multiple correlation coefficient R = 0.928.  相似文献   
34.
Arthroscopic EndoButton fixation of anterior cruciate ligament (ACL) grafts over the femoral cortex has become popular in recent years. However, elongation of fixation materials has lead to tunnel enlargement, graft tunnel motion and instability. Synovial fluid passages along femoral tunnels following ACL reconstruction may result in destruction of tissues. The purpose of the present study was to identify the seating position of the EndoButton in regard to the boundaries of the knee capsule in single-incision arthroscopic ACL reconstruction. A total of 20 cadaveric knees were dissected and arthroscopic drill guides were used to create tibial and femoral tunnels. The distances between the exit points and boundaries of the suprapatellar bursa at three different degrees of knee flexion were measured. The average distances from the exit points to the superior boundaries of the suprapatellar bursa were 6.89 ± 5.40 mm (range, 16.87–1.21). However, in knee flexion of greater than 90°, tunnel exits were placed below the superior boundaries of the suprapatellar bursa (−7.08 ± 3.69 mm, range, −3.24 to −12.87). In order to place the EndoButton extraarticularly, a safe degree of knee flexion during femoral tunnel drilling was defined as 80°.  相似文献   
35.
Backscatter factors, B, and mass energy-absorption coefficient ratios, (μ(en)/ρ)(w, air), for the determination of the surface dose in diagnostic radiology were calculated using Monte Carlo simulations. The main purpose was to extend the range of available data to qualities used in modern x-ray techniques, particularly for interventional radiology. A comprehensive database for mono-energetic photons between 4 and 150 keV and different field sizes was created for a 15 cm thick water phantom. Backscattered spectra were calculated with the PENELOPE Monte Carlo system, scoring track-length fluence differential in energy with negligible statistical uncertainty; using the Monte Carlo computed spectra, B factors and (μ(en)/ρ)(w, air) were then calculated numerically for each energy. Weighted averaging procedures were subsequently used to convolve incident clinical spectra with mono-energetic data. The method was benchmarked against full Monte Carlo calculations of incident clinical spectra obtaining differences within 0.3-0.6%. The technique used enables the calculation of B and (μ(en)/ρ)(w, air) for any incident spectrum without further time-consuming Monte Carlo simulations. The adequacy of the extended dosimetry data to a broader range of clinical qualities than those currently available, while keeping consistency with existing data, was confirmed through detailed comparisons. Mono-energetic and spectra-averaged values were compared with published data, including those in ICRU Report 74 and IAEA TRS-457, finding average differences of 0.6%. Results are provided in comprehensive tables appropriated for clinical use. Additional qualities can easily be calculated using a designed GUI interface in conjunction with software to generate incident photon spectra.  相似文献   
36.
The aims of the study were to determine: (1) the relationship between parity and bone mineral density (BMD); (2) the relationship between parity and osteoporotic peripheral fractures.

Material and methods

The group studied included 730 postmenopausal women. Patients were separated into four groups according to the number of fullterm pregnancies, group 1: nulliparae, group 2: one to three pregnancies, group 3: four to five pregnancies, and group 4: six and more pregnancies. Additionally, patients were separated into three groups according to their ages, as <50 years, 50–59 years and ≥60 years.

Results

The median parity was 4 [0–20]. All the patients with parity greater than six had spine and hip BMD values significantly lower than values in the other groups (p < 0.001). After adjustment for age and body mass index (BMI), decreased lumbar and total hip BMD were still associated to increased parity (analysis of covariance (ANCOVA), p = 0.04 and 0.023, respectively). The relation between parity and lumbar BMD was highly significant among women aged <50 years (age-adjusted p = 0.022), while there was no parity-spine BMD association in the other age groups. The relation between parity and hip BMD was seen only in the group 50–59 years (age-adjusted p = 0.042). A positive history for peripheral fractures was present in 170 (23%) patients. There was relationship between parity and peripheral fractures neither in the whole population nor in the sub-groups according to age.

Discussion

The present study suggests that the BMD of the spine and hip decreases with an increasing number of pregnancies, and this situation shows variations in different age groups. However, there was no correlation between parity level and peripheral fractures.  相似文献   

37.
International Urology and Nephrology - To compare the heart rate increase side effect of different antimuscarinic drugs used in overactive bladder (OAB). Overall 341 patients were consecutively...  相似文献   
38.
PURPOSE: Rathke's cleft cysts are non neoplastic lesions of the sellar area that seldom are symptomatic. Their incidence has been underestimated before magnetic resonance imaging (MRI). The aim of this work was to assess the value of MRI in the diagnosis and differential diagnosis of Rathke's cleft cyst based on a retrospective review of 12 cases and a review of the literature. PATIENTS AND METHODS: We retrospectively reviewed the MRI features of 12 patients with Rathke's cleft cyst collected over 4.5 years. Patients included ten females and two males (mean age: 39 years). The most common presentation was the association of dysmenorrhea and pituitary dysfunction. MRI examinations were performed using a 1.5 Tesla system, T1 and T2 weighted sequences performed before and after Gd- DTPA injection. Signal intensity, shape, size and location of the lesion were analyzed. RESULTS: In all cases, MRI examination showed a cystic lesion of variable size and signal intensity. The cyst was purely intrasellar in nine cases and a suprasellar extension was noted in three cases. Five patients underwent surgery providing pathological confirmation, four underwent routine follow-up and three were lost of follow-up. CONCLUSION: We conclude that MRI is an efficient tool for diagnosis, allowing appropriate medical decision making.  相似文献   
39.
Transverse fractures of the sacrum with major displacement are rare and often misdiagnosed. A case of transverse fracture of the sacrum with cauda equina injury is reported. The diagnosis was not recognized initially. Conventional radiographs of the pelvis failed to demonstrate the fracture. True lateral sacral views and CT scan with reconstructions allowed analysis of the different sagittal fracture lines to facilitate surgical planning. These examinations should be considered in all patients with history of high energy trauma and clinical signs indicating lumbosacral injury.  相似文献   
40.
Emergency Radiology - Mastoid air cell fluid is a commonly seen, but often dismissed finding. Given the location of the mastoid portion of the temporal bone and its location adjacent to vital...  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