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   1286篇
  免费   72篇
  国内免费   3篇
耳鼻咽喉   15篇
儿科学   128篇
妇产科学   70篇
基础医学   120篇
口腔科学   54篇
临床医学   116篇
内科学   250篇
皮肤病学   50篇
神经病学   85篇
特种医学   72篇
外科学   207篇
综合类   20篇
预防医学   26篇
眼科学   60篇
药学   26篇
中国医学   13篇
肿瘤学   49篇
  2024年   2篇
  2023年   13篇
  2022年   24篇
  2021年   40篇
  2020年   32篇
  2019年   51篇
  2018年   39篇
  2017年   38篇
  2016年   38篇
  2015年   46篇
  2014年   46篇
  2013年   70篇
  2012年   80篇
  2011年   87篇
  2010年   62篇
  2009年   50篇
  2008年   107篇
  2007年   114篇
  2006年   81篇
  2005年   73篇
  2004年   68篇
  2003年   50篇
  2002年   48篇
  2001年   22篇
  2000年   13篇
  1999年   24篇
  1998年   3篇
  1997年   4篇
  1996年   4篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   3篇
  1990年   1篇
  1989年   2篇
  1987年   2篇
  1983年   1篇
  1980年   1篇
  1976年   1篇
  1975年   1篇
  1974年   4篇
  1973年   3篇
  1971年   4篇
  1970年   3篇
  1969年   3篇
排序方式: 共有1361条查询结果,搜索用时 15 毫秒
1.
Gallbladder sludge and acute pancreatitis induced by acute hepatitis A.   总被引:1,自引:0,他引:1  
In this case report, a young woman with gallbladder sludge and acute pancreatitis due to acute hepatitis A (HAV) is presented. She was admitted to our hospital with abnormal hepatic enzymes. Five days prior to her admission, an initial abdominal ultrasound was performed at another hospital and revealed no abnormality, while her serum aspartate aminotransferase (AST) level was at the upper limit of normal (ULN) x 8. A second ultrasound was performed at our hospital and revealed a gallbladder wall thickness (9.3 mm), gallbladder sludge in the gallbladder lumen, pancreatic edema, ascites, and hepatomegaly while AST was at the ULN x 50. Magnetic resonance imaging and magnetic resonance cholangiopancreatography revealed imaging features of an acute stage of pancreatitis and gallbladder wall thickness with coexisting sludge in the gallbladder lumen. HAV infection was diagnosed by the detection of immunoglobulin M against HAV in the serum. The patient underwent two repeated abdominal ultrasound examinations on the 5th (AST was at the ULN x 3) and the 20th days (AST was at the normal) after her discharge, and both revealed normal findings. In our case, we observed reversible changes in the hepatobiliary and pancreatic system which was related to the severity of hepatic necro-inflammation. HAV-associated pancreatitis may be due to the formation of biliary sludge during the acute phase of the viral illness, but this association needs further investigation.  相似文献   
2.
AIM: To evaluate the effects of oral continuous 17beta-estradiol plus norethisterone acetate (E2/NETA) replacement therapy on abdominal subcutaneous fat, serum leptin level (SLL) and body composition in postmenopausal women. MATERIALS AND METHODS: A 6-month, prospective, randomized, double-blind and placebo-controlled study was conducted. Forty-three healthy naturally postmenopausal women aged 43-65 years were randomly assigned to receive E2/NETA (2 mg E2 plus 1 mg NETA, n = 22) or placebo (n = 21). Fasting SLL by enzyme-linked immunosorbent assay, subcutaneous abdominal fat thickness (STh) by ultrasound and the anthropometric indices of body weight (BW), body mass index (BMI), waist and hip circumference (WC, HC) and waist-to-hip ratio (WHR) were recorded at the beginning and the end of the study. RESULTS: After 6 months of therapy, BW and SLL increased in the placebo group (p = 0.043 and 0.033, respectively). WC, HC and STh decreased significantly in the E2/NETA group (p = 0.002, 0.006 and 0.000, respectively) and they were also significantly lower in women receiving E2/NETA than in women taking placebo (p = 0.000, 0.034 and 0.000, respectively). At baseline, SLL and STh were positively correlated with all anthropometric indices except WHR. CONCLUSION: Oral continuous combined regimen of E2/NETA significantly reduced central fat accumulation as assessed by WC and STh, and attenuated the increase in SLL. The observed changes in SLL were highly and positively related to changes in STh. The oral continuous combined E2/NETA regimen appears to have protective effects on cardiovascular function and probably on metabolic diseases by its slimming effect upon WC in postmenopausal women.  相似文献   
3.
OBJECTIVE: Monitoring of the dorsal sural sensory nerve action potential (SNAP) is a sensitive method for detection of peripheral neuropathies. We tried to determine the normal dorsal sural nerve conduction values of the childhood population and assessed the clinical utility of this method in diabetic children who have no clinical sign of peripheral neuropathy. METHODS: In the study, 36 healthy and 27 diabetic children were included. In all subjects peripheral motor and sensory nerve studies were performed on the upper and lower limbs including dorsal sural nerve conduction studies. RESULTS: The dorsal sural SNAP mean amplitude was 8.24+/-3.08 microV, mean latency was 2.47+/-0.48 ms, mean sensory conduction velocity was 41.63+/-5.43 m/s in healthy children. Dorsal sural SNAPs were absent bilaterally in one diabetic patient. In the other 26 diabetic patients, the mean dorsal sural nerve distal latency was longer (2.93+/-0.63 ms, P = 0.004), mean SCV was slower than in healthy subjects (36.68+/-7.66 m/s, P = 0.005). However, dorsal sural nerve amplitude was not different between the groups. A dorsal sural nerve latency of more than 2.9 ms had a sensitivity of 50% and a specificity of 75%. A dorsal sural nerve velocity of less than 36 m/s had a sensitivity of 54% and a specificity of 92%. CONCLUSIONS: We designated the reference values of the dorsal sural nerve in healthy children. In addition, our findings suggest that dorsal sural nerve conduction studies may have value to determine neuropathy in the early stages in children with diabetes. SIGNIFICANCE: The dorsal sural nerve conduction studies in diabetic children may have value to determine the neuropathy in its early stages.  相似文献   
4.
OBJECTIVE: The aim of this study is to investigate dose-dependent effect of the topical application of methotrexate (MTX) in rats on the normal nasal mucosa, liver tissue, liver enzymes, and hemoglobin levels. STUDY DESIGN: Preclinical animal study. SETTING: Twenty male adult wistar albino rats were randomly divided into 4 groups (n=5). A single puff of MTX (2.5 microg) was applied to both nasal cavities 2 times a day. The animals were given MTX 1 day a week in group 1, 3 days a week in group 2, and 5 days a week in group 3. Control group animals were given 1 puff of physiologic saline to both nasal cavities 5 days a week and 2 times a day. After 28 days, liver biopsies, blood samples, and 5 nasal mucosal biopsies were taken. Histological examination was made with respect to certain parameters semiquantitatively (grade 0-3). The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and hemoglobin counts were studied from blood samples. RESULTS: There are no statistically significant differences with respect to histopathological parameters between the control group and the groups 1-3 (P>0.05). Histopathological examination of liver tissue did not reveal any evident difference between the control and study groups. Mean AST and ALT as liver function tests and hemoglobin counts were within normal limits. Topical application of MTX at these doses has no toxic effect on the nasal mucosa, the liver tissue, AST and ALT levels, and hemoglobin level. CONCLUSIONS: These results have been encouraging to investigate use of the topical application of MTX in nasal manifestation of autoimmune disease or addition of the topical application of MTX to the steroid treatment in cases with massive nasal polyposis resistant to steroids and prone to recurrence.  相似文献   
5.
OBJECTIVE: The purpose of this study was to investigate the incidence of the retroaortic left renal vein (RLRV) in patients with varicocele. METHODS: The left renal vein was ultrasonographically investigated for the presence of the RLRV in 140 patients with varicocele and a control group of 137 age-matched patients. The main diagnostic criteria for varicocele were the presence of a varicose vein with a diameter of 3 mm or larger at rest and with a reflux lasting more than 2 seconds during the Valsalva maneuver. The RLRV was defined as a posterior course of the left renal vein to the aorta at the level of the origin of the superior mesenteric artery. RESULTS: The RLRV was observed in 13 (9.3%) of the 140 patients with varicocele and 3 (2.2%) of the control patients. The incidence of the RLRV was found to be significantly higher in patients with varicocele compared with the control patients (P = .018, Fisher exact test). In 13 patients with the RLRV, left varicocele and bilateral varicocele were detected in 10 and 3 cases, respectively. CONCLUSIONS: In this study, the incidence of the RLRV was found to be significantly higher in patients with varicocele compared with control patients. Thus, we suggest that the presence of the RLRV may be considered one of the etiologic factors in the development of varicocele.  相似文献   
6.
BACKGROUND: Mycobacteria are being investigated for modulation of inflammation in asthma and atopic disorders by eliciting particularly strong protective TH1 immune responses. OBJECTIVE: To investigate the long-term effects of intratracheally administered Mycobacterium vaccae on an experimental murine model of asthma. METHODS: BALB/c mice were placed in 4 groups: long-term M. vaccae, M. vaccae, asthma, and control groups. All groups but controls were sensitized intraperitoneally and challenged intratracheally with ovalbumin. The long-term M. vaccae and M. vaccae groups were treated with M. vaccae intratracheally simultaneously during challenges. Finally, mice in the long-term M. vaccae group were rechallenged with ovalbumin nebulization 24 days later. Evaluations of lung histopathologic findings and serum cytokine levels were performed. RESULTS: Comparison of the long-term M. vaccae group with the asthma model group revealed that the number of hyperplasic goblet cells in small and large airways (small airway: P < .05; large airways: P < .01) and thickness of basement membrane in large airways were significantly less in the long-term M. vaccae group. Furthermore, numbers of hyperplasic goblet cells in small airways (P < .05) and basement membrane in the large airway (P < .05), as well as inflammation in small airways (P < .01), were significantly less in the M. vaccae group when compared with the asthma model group. Interferon-gamma secretion from splenocytes of the M. vaccae group was significantly higher than the asthma model and long-term M. vaccae groups. CONCLUSION: Intratracheal administration of M. vaccae exerted a long-lasting ameliorating effect on airway histopathologic features of a murine asthma model.  相似文献   
7.
Retrorectal or presacral tumors are rare lesions located in the presacral area and considered as being derived from multiple embryological remnants. These tumors are classified as congenital, neurogenic, osseous, inflammatory, or miscellaneous. The most common among these are congenital benign lesions that present with non-specific symptoms, such as lower back pain and change in bowel habit. Although congenital and developmental tumors occur in younger patients, the median age of presentation is reported to be 45 years. Magnetic resonance imaging plays a crucial role in treatment management through accurate diagnosis of the lesion, the evaluation of invasion to adjacent structures, and the decision of appropriate surgical approach. The usefulness of preoperative biopsy is still debated; currently, it is only indicated for solid or heterogeneous tumors if it will alter the treatment management. Surgical resection with clear margins is considered the optimal treatment; described approaches are transabdominal, perineal, combined abdominoperineal, and minimally invasive. Benign retrorectal tumors have favorable long-term outcomes with a low incidence of recurrence, whereas malignant tumors have a potential for distant organ metastasis in addition to local recurrence.  相似文献   
8.
Triphalangeal thumb-polysyndactyly (TPT-PS) is an isolated limb malformation consisting of pre- and postaxial polysyndactyly of hands and feet. The only family reported so far is of Dutch origin, and the genetic mapping study localized the TPT-PS locus at chromosome region 7q36 where the isolated triphalangeal thumb (TPT) anomaly has also been mapped. It was suggested that TPT-PS is a phenotypic variation of isolated TPT, and the same ancestral mutation may produce both phenotypes. Here we report on the second family with this malformation from the Turkish population. The characteristic findings in this family are triphalangeal thumb, webbing between 3rd, 4th, and 5th fingers associated with bony synostosis in the distal phalanges of the same fingers, and pre- and postaxial polysyndactyly of feet. Some individuals show a more severe phenotype with a complete syndactyly of all fingers giving a "cup-like" appearance to the hands. Genetic linkage study with DNA markers D7S1823, D7S550, D7S559, and D7S2423 demonstrated that this family is also linked to chromosome band 7q36. Identification of a second family from a distinct ethnic background suggests that TPT-PS and isolated TPT are not caused by the same ancestral mutation as it was originally anticipated.  相似文献   
9.
We describe the appearance of an adrenal neuroblastoma associated with tumor thrombus occurring in an adult patient. The tumor measured 14 x 12 x 12 cm, showed heterogeneous signal intensity on both T1-weighted and T2-weighted images, and displayed peripheral nodular enhancement on early post-gadolinium images. Tumor thrombus was identified within the inferior vena cava, which extended into the right atrium.  相似文献   
10.
Balci NC  Radjazi S  Polat H 《European radiology》2000,10(11):1708-1710
Adult intussusception secondary to inflammatory polyp occurs rarely. Imaging of intussusception on ultrasound, CT and MRI has been previously described. In this report we describe a case of an adult intussusception secondary to inflammatory fibroid polyp. Both the lead point (inflammatory fibroid polyp) and intussusception were depicted on multiplanar MR images. Findings on MRI were confirmed at surgery and histopathological examination. Received: 11 January 2000; Revised: 3 May 2000; Accepted: 4 May 2000  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