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   122篇
  免费   2篇
妇产科学   23篇
基础医学   9篇
内科学   6篇
神经病学   1篇
特种医学   2篇
外科学   33篇
预防医学   3篇
药学   17篇
中国医学   1篇
肿瘤学   29篇
  2022年   1篇
  2021年   1篇
  2020年   1篇
  2018年   3篇
  2017年   3篇
  2015年   4篇
  2014年   3篇
  2012年   9篇
  2011年   6篇
  2010年   1篇
  2009年   5篇
  2008年   6篇
  2007年   3篇
  2006年   3篇
  2005年   4篇
  2004年   3篇
  2003年   8篇
  2002年   6篇
  2001年   7篇
  2000年   6篇
  1999年   3篇
  1998年   2篇
  1995年   1篇
  1993年   1篇
  1992年   3篇
  1991年   5篇
  1990年   6篇
  1989年   5篇
  1988年   6篇
  1987年   5篇
  1986年   3篇
  1985年   1篇
排序方式: 共有124条查询结果,搜索用时 15 毫秒
31.
32.
Populations in the Amazon are exposed to organic mercury via consumption of contaminated foods. These ethnic groups consume a specific plant seed “annatto” which contains certain carotenoids. The aim of this study was to find out if these compounds (bixin, BIX and norbixin, NOR), protect against DNA‐damage caused by the metal. Therefore, rats were treated orally with methylmercury (MeHg) and with the carotenoids under conditions that are relevant to humans. The animals were treated either with MeHg (30 μg/kg/bw/day), BIX (0.1–10 mg/kg/bw/day), NOR (0.01–1.0 mg/kg/bw/day) or combinations of the metal compound and the carotenoids consecutively for 45 days. Subsequently, the glutathione levels (GSH) and the activity of catalase were determined, and DNA‐damage was measured in hepatocytes and leukocytes using single cell gel electrophoresis assays. Treatment with the metal alone caused a decrease in the GSH levels (35%) and induced DNA damage, which resulted in increased DNA migration after electrophoresis in liver and blood cells, whereas no effects were seen with the carotenoids alone. When BIX or NOR were given in combination with organic mercury, the intermediate and the highest concentrations of the carotenoids (1.0 and 10.0 mg/kg/bw/day BIX and 0.1 and 1.0 mg/kg/bw/day NOR) protected against DNA‐damage. Furthermore, we found with both carotenoids, a moderate increase in the GSH levels in both metal‐treated and untreated animals, while the activities of catalase remained unchanged. Our results indicate that consumption of BIX and NOR may protect humans against the adverse health effects caused by exposure to organic mercury. Environ. Mol. Mutagen., 2012. © 2012 Wiley Periodicals, Inc.  相似文献   
33.
Insufficient intakes of many micronutrients found in fruits and vegetables, such as folic acid, vitamins C and B6 may lead to DNA damage, cancer, and degenerative disease. The investigation of dietary antioxidants is a field of great interest for elucidating mechanisms of mutagenesis/carcinogenesis. The present study was undertaken to investigate the effects of vitamin B6 on the induction of chromosomal aberrations in cultured human lymphocytes and to examine the possible anticlastogenic effect of this vitamin on chromosomal damage induced by the antitumor drug doxorubicin. The results showed that when the cultures treated with vitamin B6 were compared with the untreated control in terms of total chromosomal damage and abnormal metaphases, pre- and simultaneous treatment with this vitamin showed no significant differences. In the post-treatment, average and above average concentrations of vitamin B6 alone showed a clastogenic effect. In the simultaneous protocol, this vitamin (15, 90 and 120 microg/mL) was effective in inhibiting chromosomal aberrations induced by doxorubicin (p<0.05), with a reduction of 33.1% with the highest concentration tested. However, in the post-treatment, the associations of vitamin B6 and doxorubicin exerted a more evident clastogenic effect than that observed in the cultures exposed only to the antitumor drug. In the present investigation, the inability of vitamin B6 to decrease chromosomal damage induced by doxorubicin in the pre- and post-treatments could be justified by the instability of this vitamin as a free radical scavenger. In conclusion, the results from this study confirmed that vitamin B6 is protective against chromosomal damage induced by doxorubicin in cultured human lymphocytes, but that the effects depend on concentration and form of treatment.  相似文献   
34.

Purpose

To analyze changes in sagittal spinopelvic parameters (SSPs) after surgical treatment of Scheuermann’s Kyphosis (SK).

Methods

We analyzed 20 patients affected by SK and subjected to posterior correction of the kyphosis by facetectomy, Ponte osteotomy, fusion and multilevel instrumentation with pedicle screw system. Four spinal and three pelvic parameters were measured: sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis, lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS) and pelvic tilt (PT). Analysis of changes in postprocedural SSPs compared to preoperative values was performed.

Results

TK passed from 78.6° preoperatively to 45.8° (p = 0.003). LL passed from 74.5° preoperatively to 53.5° (p = 0.01). No significant changes occurred in SVA, SS, PT and PI compared to preoperative values.

Conclusion

We confirm the positive effect of surgery by Ponte osteotomy and posterior spinal fusion on TK and LL in patients with SK. In our experience, pelvic parameters did not change after surgery.
  相似文献   
35.
36.
Anthracyclines and platinum derivates are active drugs for advanced endometrial carcinoma (AEC), but new schedules with higher efficacy and better tolerability are needed. A phase II study was conducted to describe activity and tolerability of carboplatin (C)+pegylated liposomal doxorubicin (PLD) in patients with AEC. Patients with chemonaive AEC, PS < or = 2, aged < 75 years, with at least one measurable lesion were eligible. Treatment was C (area under curve 5)+PLD (40 mg m(-2)) on day 1 every 4 weeks, up to six cycles. Forty-two patients were needed in a single-stage design, with at least 13 objective responses to define the treatment active. Forty-two patients were enrolled. Median age was 64 years (31-74). A total of 64% of patients were recurrent while 36% were advanced. Three complete (7%) and 22 partial responses (52%) were observed, for an overall response rate of 59.5% (95% exact CI: 43.3-74.3). One death potentially related to treatment was recorded (death at home for unknown reasons after 6th cycle). Other relevant toxicities (% of patients) were grade 3/4 neutropaenia 33%/14%, febrile neutropaenia 5%, grade 3/4 thrombocytopaenia 17%/5%, grade 3/4 anaemia 31%/2%. Skin toxicity was mild: grade 1 14%, grade 2 10%, grade 3 5%. Hair loss: complete 5%, partial 12%. The combination of carboplatin and PLD shows good activity and favourable toxicity as first-line chemotherapy of patients with AEC, deserving further studies in this setting.  相似文献   
37.
The Authors report the case of a 28-year-old patient with type 1 neurofibromatosis, who presented a pathological dislocation of the hip. This event was preceded by the development of a neurological pattern of spastic paraparesis and decreased pain sensation in both lower limbs, secondary to the progression of a dystrophic kyphoscoliosis. Pathological dislocation of the hip in neurofibromatosis has been reported in the literature as a consequence of intra-articular growth of neurofibromas. Conversely, in the case described here, clinical and radiographic features and the absence of neurofibromas in the joint, verified by means of radiographic and histological examinations, suggested the diagnosis of neuropathic arthropathy. The treatment of hip dislocation should be differentiated according to the aetiology, given the underlying articular instability in cases of neuropathic arthropathy.  相似文献   
38.
OBJECTIVE: Mucinous ovarian carcinoma has a poorer prognosis compared with other histological subtypes. The aim of this study was to evaluate, retrospectively, the activity of first-line and second-line chemotherapy in patients with mucinous ovarian cancer in a mono-institutional series. PATIENTS AND METHODS: In the period under survey (1996-2003), 225 new patients with ovarian cancer were treated. Twenty-one out of these patients (9.3%) received a diagnosis of mucinous ovarian cancer. The median age, performance status, stage at diagnosis and residual disease after surgery were similar in the mucinous compared to the other histological groups (P=NS). RESULTS: In mucinous ovarian cancer the grading of the tumors was 2 in 76% of the cases, while grade 3 was more frequent in the other subtypes (p<0.002). Eighty-five % of the patients had received carboplatin/paclitaxel, while the remaining cases had been treated with a cisplatin-based chemotherapy not containing paclitaxel. Two patients with early stage were treated with adjuvant chemotherapy and were not evaluable for response while 19 patients had measurable disease (12 pts) or were assessed at second-look (7 pts). Forty-seven % of the 19 patients experienced disease progression during first-line, while 31.5% and 10.5% complete and partial responses were recorded, respectively. Fifteen out of the 21 patients had progressed at the time of the analyses. Sixty % of the progressed patients were platinum-refractory, 3 cases were platinum-sensitive and 3 platinum-resistant. The 3 platinum-sensitive patients were treated with single agent carboplatin without any response. No response was recorded with topotecan or liposomal doxorubicin when given as second- or third-line treatment in platinum-refractory/resistant patients. CONCLUSION: Mucinous ovarian cancer has a poor response to chemotherapy both in the first-line and in the recurrence settings. Studies with alternative chemotherapy combinations are mandatory in this histological subgroup.  相似文献   
39.
Different pedicle screws were biomechanically and morphologically studied and compared through the use of an animal model to determine their efficacy and resistance in spinal fixation. The principal objective was to compare biomechanical and histomorphological aspects of HA-coated screws to uncoated ones. Fourty-eight cylindrical transpedicular self-tapping screws divided into three groups of sixteen each were employed; Group A: stainless steel screws; Group B: titanium screws; Group C: HA-coated titanium screws. The screws were implanted bilaterally and randomly into the L3, L4, and L5 pedicles of eight adult mongrel sheep. The final insertion torque was measured in all the implants. After one and four months, upon euthanization, four samples per group were extracted from the surrounding bone and the screw extraction torque was measured. The remaining samples were examined and processed for histological and histomorphological evaluations. No differences were observed at one month among the extraction torque of the three groups. After four months the only significance between insertion and extraction values was for the HA group, i.e. p=0.001. Comparing the extraction torque values of the three groups after four months of healing, the HA-coated group showed a greater than twofold increase (p<0.0005). No differences were observed at one month among the percentages of bone-implant contact in the three groups. After four months the percentage was significant only for the C group (p<0.0005). At four months a correlation was found between the morphological and the biomechanical data of group C (p<0.0005). The use of hydroxyapatite-coated screws could act as an effective method to improve the bone-implant interface, thus obtaining a strong fixation of the implant independently of the arthrodesis achieved with bone graft.  相似文献   
40.
Macronutrients, fatty acids and cholesterol intake and endometrial cancer.   总被引:1,自引:0,他引:1  
BACKGROUND: There is some evidence that dietary habits may influence the risk of endometrial cancer independently of body mass, although the role of diet on endometrial carcinogenesis is unclear. PATIENTS AND METHODS: We carried out a multicenter case-control study from 1992 to 2006 in Italy on 454 women with incident, histologically confirmed endometrial cancer (age range 18-79 years) and 908 controls (age range 19-79 years) admitted to hospitals for acute, non-neoplastic diseases. A validated food-frequency questionnaire was used to estimate macronutrients, fatty acids and cholesterol intake. Logistic regression models, conditioned on age and study centre, and adjusted for major known risk factor of endometrial cancer and residual of energy intake were used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Significant direct associations were observed with intake of energy (OR = 1.7 for the highest versus the lowest quintile, 95% CI = 1.1-2.5), and cholesterol (OR = 2.1, 95% CI = 1.4-3.2), while a direct borderline association emerged with saturated fatty acids (OR = 1.3, 95% CI = 0.9-2.0). There was no association with proteins, sugars, starch, total fat and other selected fatty acids. CONCLUSION: Energy and cholesterol intake were associated with endometrial cancer.  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