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   709篇
  免费   24篇
  国内免费   7篇
耳鼻咽喉   33篇
儿科学   57篇
妇产科学   46篇
基础医学   53篇
口腔科学   11篇
临床医学   51篇
内科学   113篇
皮肤病学   35篇
神经病学   56篇
特种医学   24篇
外科学   131篇
综合类   8篇
预防医学   34篇
眼科学   34篇
药学   34篇
肿瘤学   20篇
  2023年   3篇
  2022年   5篇
  2021年   4篇
  2020年   12篇
  2019年   16篇
  2018年   16篇
  2017年   13篇
  2016年   20篇
  2015年   29篇
  2014年   15篇
  2013年   28篇
  2012年   52篇
  2011年   41篇
  2010年   30篇
  2009年   25篇
  2008年   76篇
  2007年   87篇
  2006年   65篇
  2005年   59篇
  2004年   44篇
  2003年   33篇
  2002年   17篇
  2001年   12篇
  2000年   12篇
  1999年   11篇
  1998年   1篇
  1997年   1篇
  1994年   1篇
  1992年   5篇
  1987年   1篇
  1986年   2篇
  1984年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
排序方式: 共有740条查询结果,搜索用时 593 毫秒
101.
Steroidal hormones produced by humans and animals are constantly being excreted into the environment. It has been demonstrated that sewage effluent discharged to surface water contains natural estrogens and synthetic estrogenic chemicals. As estrogen levels continuously increase in the aquatic environment, it is very important to have a detailed understanding of estrogens' effects on fish. In the present study, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 17beta-estradiol (E2) for 3 weeks and the effects of E2 on rainbow trout livers were investigated at the molecular level using Fourier transform infrared spectroscopy. The results revealed that E2 induced significant alterations in the liver tissues. A decrease in glycogen levels and protein concentration, and an increase in both the population of hepatic lipids, especially triglycerides, as well as the relative content of nucleic acids was observed in the E2 treated liver. In addition, a decrease in the membrane fluidity and an increase in lipid order were found in the cells of treated samples. In order to compare the effect of E2 with that of NP at molecular level, the fish were also treated with an estrogenic compound, nonylphenol (NP). The NP-treated fish liver spectra were found to be quite similar to those of E2-treated fish confirming that NP mimics the effect of E2 in immature rainbow trout.  相似文献   
102.
103.
OBJECTIVE: The purpose of this study was to investigate the effect of raloxifene on leptin and insulin-like growth factor-I levels and their relation with the biochemical markers of bone metabolism in postmenopausal women. STUDY DESIGN: Sixty-four women were given 60 mg/d raloxifene for 6 months. Serum leptin, insulin-like growth factor-I, alkaline phosphatase, calcium, osteocalcin, and collagen type I cross-link C-telopeptide levels were measured before and after the treatment. The patients were grouped as obese (body mass index, > or =25 kg/m2) or non-obese (body mass index, <25 kg/m2). RESULTS: The mean basal leptin level was significantly higher (P < .001), and the mean cross-link C-telopeptide level was significantly lower (P = .001) in obese patients. Raloxifene therapy increased leptin levels (P < .001) and decreased insulin-like growth factor-I, alkaline phosphatase, and cross-link C-telopeptide levels significantly (P < .001). There was a strong negative correlation between leptin and cross-link C-telopeptide (r = -0.703; P < .001). Insulin-like growth factor-I was not correlated with any parameter. CONCLUSION: Raloxifene increases serum leptin levels while decreasing bone resorption in postmenopausal women.  相似文献   
104.
105.
A 50 year-old male patient was referred to our clinic due to a floating mass in the right eye. The uncorrected visual aquity was 10 / 10 in both eyes.The patient did not have any systemic disorder and trauma history. His ophthalmological examination revealed an unremarkable anterior segment with no signs of inflammation. Indirect opthalmoscopy and posterior segment biomicroscopy performed with 90D lens was unremarkable in the left eye, while in the right eye a single oval cyst was identified floating freely in the vitreous. The cyst was partially masking the underlying retinal vasculature. B-scan ultrasound revealed an echo-free, round-shaped cyst that was free from surrounding vitreous strands or retina localised at the posterior vitreous. Fluorescein angiography (FA) ruled out the presence of intra and overlying vascularisation of the cyst. Indeed, FA showed a clear-edged hypofluorescence due to a pre-retinal masking effect. The indirect hemaglutinin tests of the patient for ecinococcus and cysticercosis were negative. Eosinophilia was not detected in the preripheral blood smear. Based on these findings the patient was diagnosed as primary vitreal cyst. The presented case was mild symptomatic so the patient was decided to be followed up without any treatment.  相似文献   
106.
Fas (CD95/APO-1) is a protein that is mainly related to apoptosis of lymphoid cells. The increment of Fas expression is associated with long-term survival in various malignancies. However, there are limited studies regarding the effect of Fas expression on the course and prognosis of non-Hodgkin's lymphoma. The aim of this study was to investigate the significance of immunohistochemical Fas expression on the prognosis of nodal diffuse large B-cell lymphoma. A total of 63 patients with primary nodal diffuse large B-cell lymphoma diagnosed in the Erciyes University Department of Hematology between 1990 and 2003 were included in the study. The median age of the patients was 55 years old (range 19-102 years old). The median follow-up period was 19 months (2-132 months). Histopathological sections were stained immunohistochemically and evaluated by light microscopy for Fas, bcl-2, and p53. Clinical and laboratory parameters including Fas, bcl-2, and p53 positivity, age, sex, performance status, clinical stage, presence of B symptoms, bone marrow involvement, extranodal involvement, and lactic dehydrogenase levels were evaluated to compare overall survival. Complete remission was obtained in 28 patients (44.4%) after first-line chemotherapy. Fas positivity, male gender, good performance status, clinical stage I-II, absence of B symptoms, normal lactic dehydrogenase value, and absence of bone marrow involvement were favorable prognostic factors for complete remission in statistical analysis. Multivariate analysis revealed that positive Fas expression and ECOG performance status were independent prognostic factors for overall survival. Also, Fas-positive patients had significantly prolonged progression-free survival. Immunohistochemical Fas positivity was a favorable prognostic factor for complete remission and overall and progression-free survival in primary nodal diffuse large B-cell lymphoma.  相似文献   
107.
We aimed to evaluate the efficacy of treatment with partially hydrolyzed guar gum (PHGG) using a rat model of ileal pouch-anal anastomosis and pouchitis. In the J pouch groups, tissue myeloperoxidase activities were significantly higher than native myeloperoxidase activities (P = 0.020; P = 0.015; P = 0.004, respectively). A statistically significant difference in total histological score was detected in the J pouch + 5% dextran sulfate sodium (DSS) group, compared to the J pouch control and the J pouch + 5% DSS + PHGG groups (P < 0.01 and P < 0.01, respectively). There was a significant overgrowth of aerobes and anaerobes in the J pouch + 5% DSS group. This study demonstrated that rectal administration of PHGG attenuates the severity of pouchitis in a rat model. In conclusion, PHGG may be an additional therapeutic strategy for the treatment of pouchitis.  相似文献   
108.
AIM: To investigate the gastroprotective effect of vardenafil against indomethacin-induced gastric damage.METHODS: Forty-eight female Wistar albino rats were randomly divided into 6 groups. Group 1 received saline only. Group 2 (indomethacin) received indomethacin.Rats in group 3 and 4 were pretreated with different doses of famotidine. Group 5 and 6 were pretreated with different doses of vardenafil. Rats in groups 3 to 6 received 25 mg/kg indomethacin 30 min after pretreatment. The animals were sacrificed 6 h later and their stomachs were opened. Gastric lesions were counted and measured. The stomach of each animal was divided in two parts for histopathological examinations and nitric oxide (NO) and malondialdehyde (MDA) assays, respectively.RESULTS: There were no gastric mucosal lesion in the saline group but all rats in the indomethacin group had gastric mucosal ulcerations (ulcer count; 6.25 ± 3.49,and mean ulcer area; 21.00 ± 12.35). Ulcer counts were diminished with famotidine 5 mg/kg (4.12 ± 2.47, P > 0.05), 20 mg/kg (2.37 ± 4.43, P < 0.05), vardenafil 2 mg/kg (4.37 ± 3.06), and vardenafil 10 mg/kg (1.25 ± 1.38, P < 0.05) compared to the indomethacin group.Gastric mucosal lesion areas were diminished with famotidine 5 mg/kg (8.62 ± 2.97, P < 0.001), famotidine 20 mg/kg (0.94 ± 2.06, P < 0.001), vardenafil 2 mg/kg (6.62 ± 5.87, P < 0.001), and vardenafil 10 mg/kg (0.75 ± 0.88, P < 0.001) compared to the indomethacin group. MDA levels were significantly higher in indomethacin group (28.48 ± 14.51), compared to the famotidine 5 mg/kg (6,21 ± 1.88, P < 0.05), famotidine 20 mg/kg (5.88 ± 1.60. P < 0.05), vardenafil 2 mg/kg (15.87 ± 3.93, P < 0.05), and vardenafil 10 mg/kg (10.97 ± 4.50,P < 0.05). NO concentration in gastric tissues of the famotidine groups were significantly increased ( P < 0.05),but the NO increases in the vardenafil groups were not statistically significant. Histopathology revealed diminished gastric damage for pretreatment groups compared to the indomethacin group ( P < 0.05).CONCLUSION: Vardenafil affords a significant dosedependent protection against indomethacin induced gastric mucosal lesions in rats.  相似文献   
109.
Purpose Cases treated surgically using wide excision plus classic Limberg flap or wide excision plus asymmetric modified Limberg flap were compared with respect to complications and patient comfort in the postoperative period. Methods In this prospective, randomized study, 68 of 70 patients were followed for a mean of 29.22 (range, 6–44) months after wide excision plus classic Limberg flap (Group 1, n = 35) and after asymmetric modified Limberg flap closure (Group 2, n = 33). Results There were significantly more macerations in Group 1 (P < 0.001). All macerations were detected on the lower part of the incision left on the intergluteal sulcus, and infections occurred subsequent to maceration. The infection rate was statistically higher in Group 1 than in Group 2 (P = 0.028). We noted that as a result of these complications, time to suture removal (P = 0.001), discharge from hospital (P = 0.001), and time off from work (P = 0.001) were significantly longer for Group 1 than for Group 2. There were two recurrences in the inferior part of the suture line in Group 1 and none in Group 2, which showed no statistical difference (P = 0.493). Conclusions The deep intergluteal sulcus and midline gap were slightly flattened over the anococcygeal region. The vacuum effect was decreased, and there were less macerations and fewer infections. Time off from work and discharge time from hospital were shortened by eliminating the moisture effect and reducing complications by lateralizing the lower part of the suture line.  相似文献   
110.
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