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   2336篇
  免费   95篇
  国内免费   33篇
耳鼻咽喉   116篇
儿科学   90篇
妇产科学   118篇
基础医学   211篇
口腔科学   83篇
临床医学   177篇
内科学   538篇
皮肤病学   19篇
神经病学   172篇
特种医学   125篇
外科学   527篇
综合类   33篇
预防医学   46篇
眼科学   97篇
药学   66篇
中国医学   8篇
肿瘤学   38篇
  2024年   4篇
  2023年   15篇
  2022年   25篇
  2021年   44篇
  2020年   32篇
  2019年   30篇
  2018年   63篇
  2017年   45篇
  2016年   81篇
  2015年   97篇
  2014年   98篇
  2013年   135篇
  2012年   153篇
  2011年   153篇
  2010年   114篇
  2009年   78篇
  2008年   205篇
  2007年   194篇
  2006年   192篇
  2005年   189篇
  2004年   153篇
  2003年   153篇
  2002年   97篇
  2001年   13篇
  2000年   10篇
  1999年   6篇
  1998年   10篇
  1997年   14篇
  1996年   11篇
  1995年   5篇
  1994年   4篇
  1993年   4篇
  1992年   2篇
  1991年   2篇
  1990年   3篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1979年   2篇
  1977年   2篇
  1976年   2篇
  1974年   3篇
  1971年   2篇
  1970年   1篇
  1968年   1篇
  1966年   1篇
  1939年   1篇
  1937年   1篇
  1936年   2篇
  1928年   1篇
排序方式: 共有2464条查询结果,搜索用时 13 毫秒
81.
Herein we report the case of a patient with primary amenorrhea and cyclic menouria. The patient was a 20-year-old woman with primary amenorrhea and inability to achieve sexual intercourse. Clinical examination revealed normally developed labia majora and minora, clitoris, and external urethral orifice, but no vaginal opening. A mature female pubic hair pattern was present, and axillary hair development was normal. Breasts were normally developed. Abdominopelvic magnetic resonance imaging demonstrated a remnant upper vagina and unicornuate uterus filled with fluid, and left-sided renal agenesis. Intraoperatively, a congenital vesicouterine fistulous tract was observed. The fistulous tract was completely resected. Vaginal reconstruction using a sigmoid colon pedicled flap was performed. The proximal part of the neovagina was connected to the remnant cervix, and a Foley catheter was left in the uterine cavity for 7 days to prevent obstruction. The patient has been menstruating regularly since the operation. Menouria might be an early sign of congenital vesicouterine fistula. Resection of the fistulous tract with uterine preservation might be considered in patients with vaginal agenesis.  相似文献   
82.
83.
Morphology of the lumbar spinal canal in normal adult Turks   总被引:2,自引:0,他引:2  
Pathological changes can occur in the diameters of the lumbar spinal canal. Therefore, assessing the canal size an important diagnostic procedure. Two hundred plain anterioposterior radiographs of the lumbar spine were examined. The sample consisted of 100 males and 100 females. The transverse diameter of the bony spinal canal (interpedicular distance), which was measured as the minimum distance between the medial surfaces of the pedicles of a given vertebra, was measured. In addition, the transverse diameter of the vertebral body, which was measured as the minimum distance across the waist of the vertebra, was measured. The distances were measured to the nearest one tenth of a millimetere using a Vernier caliper. At all levels (L1 - L5) the transverse diameters of the lumbar spinal canal were approximately 1 - 1.5 mm higher in males than in females. The intersegmental differences increased proximodistally, in both sexes. The ratio of the transverse diameter canal to the width of the vertebra ranged from 0.55 to 0.60 mm in both sexes. The distribution of the different lumbar canal types were 47% A, 42% B, 11% C. Additionally, subtypes were determined and classified.  相似文献   
84.
85.
The case of an eight-year-old girl with congenital double-orifice mitral valve associated with atrioventricular septal defect is reported. This rare mitral valve anomaly was diagnosed with two-dimensional echocardiography. The associated atrioventricular septal defect was repaired successfully. The central fibrous bridge between anterior and posterior mitral valve leaflets was left undivided to avoid iatrogenic mitral regurgitation. Preoperative diagnosis may provide some useful information to the surgeon. The surgical method can be individualized in each case.  相似文献   
86.
AIM: To investigate how the location of the placenta at term pregnancies affects the duration of the third stage of labor and to discuss the possible mechanisms affecting the duration of the third stage. We believe that this is the first prospective study comparing the duration of the third stage of labor according to placental location. METHODS: The placental implantation was determined as anterior (n = 78), posterior (n = 59), or fundal (n = 64) by ultrasound, in 201 women with singleton pregnancies. After delivery of the newborn, oxytocin infusion was routinely given. Duration of the third stage of labor was compared by anova. P < 0.05 was determined as significant. RESULTS: The duration of the third stage of labor was 10.36 +/- 5.94 min, 10.44 +/- 5.35 min, and 8.12 +/- 4.25 min with placentas located anteriorly, posteriorly, and fundal, respectively. The length of the third stage was significantly shorter in the fundal placenta group. CONCLUSION: In this study, the length of the third stage of labor was approximately 2 min shorter with placentas located at the fundus compared to the other two groups. The mechanism responsible for shorter duration may be the bipolar separation of fundal placentas in contrast to usual unipolar down-up separation of anterior or posterior placentas. Another contributing factor may be the use of oxytocin infusion for the management of the third stage, however this should be investigated by further studies by using real time ultrasonography.  相似文献   
87.
OBJECTIVE: To investigate the effect of continuous administration of gonadotropin-releasing hormone agonist (GnRHa) during the luteal phase in an intracytoplasmic sperm injection program. STUDY DESIGN: One hundred eighty-one women underwent a down-regulation protocol of GnRHa administered from the 21st day of the preceding cycle. Patients were randomized at initiation of stimulation by a computer-generated list. Group 1 patients (n = 90) were continuously administered GnRHa for 12 days after embryo transfer, while in group 2 patients GnRHa was stopped on the day of human chorionic gonadotropin administration. RESULTS: Demographic parameters, infertility etiologies, number of gonadotropin ampules used, number of mature oocytes recovered, rates of testicular sperm usage, number of embryos transferred, and cycle and transfer cancellation rates were similar in both groups. Clinical pregnancy rates, implantation rates and live birth rates did not show a significant difference. CONCLUSION: Extending GnRHa treatment through the luteal phase appeared not to have a significant impact on pregnancy or implantation rates in intracytoplasmic sperm injection cycles.  相似文献   
88.
Morgagni hernia (MH) is a congenital herniation of the abdominal organs through the subcostosternal portion of the diaphragm. It is a rare type of diaphragmatic hernia that has been associated with other congenital anomalies. The purpose of this clinical review was to determine the incidence of associated anomalies in patients with MH at a major pediatric referral center. The medical records of all patients with the diagnosis of MH were reviewed retrospectively between 1983 and 2006. The age, sex, side of herniation, presenting symptoms and signs, associated anomalies, radiologic features, intraoperative findings, postoperative course, complications, and mortality were recorded. There were 11 males and 5 females. The average age of the patients was 34.5 months (range 2 months–14 years). Twelve patients (75%) had at least one associated congenital malformation and eight (66.6%) of them had multiple anomalies. Six (37.5%) patients had a chromosomal anomaly, Down’s syndrome in five and Turner syndrome in one. MH has a high incidence of associated congenital malformations.  相似文献   
89.
Ozbaran B, Kose S, Yagdi T, Engin C, Erermis S, Yazici KU, Noyan A, Ozbaran M. Depression and anxiety levels of the mothers of children and adolescents with left ventricular assist devices. Abstract: VADs have been used to provide treatment for end‐stage heart failure. Parents may feel overwhelmed with the VAD regimes responsibility and be affected from this process beside children. In this study, we aimed to evaluate the depressive and anxiety symptoms of mothers of the first eight children equipped with a VAD in Turkey. The mothers of eight pediatric patients living with VADs were filled BDI and STAI at first month of VAD implantation (E.I) and secondly six months after their first evaluation (E.II). In E.I, the BDI mean score of mothers was 20.87, in E.II 14.37. STAI‐S mean score was 53.37 in E.I and 43.62 in E.II. The Wilcoxon nonparametric‐paired t‐test revealed significant difference between baseline and end‐point STAI‐S scores (Z: ?2.035; p: 0.042), and for BDI scores (Z, ?1.965; p, 0.049). Prolonged usage of VAD may increase distress in parents. Psychiatric evaluation and support of the primary caregiver is important for the well‐being of the pediatric patients.  相似文献   
90.
OBJECTIVE: The goal of this study was to search the effects of two different doses of tibolone on endometrial IGF-1 and IGFBP-1 levels in ovariectomized rats. METHODS: Eighteen adult, female, 80-90-days-old, Wistar rats with an average weight of 250 g underwent bilateral ovariectomy under general anesthesia. After waiting for 4 weeks, they were randomized into three groups to receive either oral tibolone in two different doses or placebo. The treatment was continued for 5 weeks, and then the rats were sacrificed and the endometria were analyzed. RESULTS: Low columnar epithelium of the endometrial surface, longer epithelium and stratified squamous epithelium were seen in the control, low-dose and high-dose groups, respectively. The staining intensity of IGF-1 was mild in control, and moderate in both treatment groups, the difference between control the treatment groups was significant (P=0.015 for group L, and P=0.03 for group H). The staining intensity of IGFBP-1 was moderate in control, and strong in groups L and H. Again the difference was significant between control and both treatment groups (P=0.039 for grup L, and P=0.03 for group H). No significant difference was noted between each treatment group for both IGF-1 and IGFBP-1. CONCLUSION: Tibolone caused histological changes in endometrium and stimulated IGF-1 and IGFBP-1 staining. Both low and high dose treatments led to moderate and strong staining intensities for IGF-1 and IGFBP-1, respectively. The strong staining intensity of IGFBP-1 is likely due to the progestagenic effect of tibolone.  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