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   1308篇
  免费   72篇
  国内免费   5篇
耳鼻咽喉   9篇
儿科学   63篇
妇产科学   52篇
基础医学   152篇
口腔科学   28篇
临床医学   106篇
内科学   378篇
皮肤病学   9篇
神经病学   134篇
特种医学   44篇
外科学   114篇
综合类   3篇
预防医学   66篇
眼科学   8篇
药学   106篇
中国医学   2篇
肿瘤学   111篇
  2023年   14篇
  2022年   11篇
  2021年   21篇
  2020年   26篇
  2019年   23篇
  2018年   41篇
  2017年   26篇
  2016年   43篇
  2015年   41篇
  2014年   38篇
  2013年   76篇
  2012年   78篇
  2011年   77篇
  2010年   44篇
  2009年   40篇
  2008年   54篇
  2007年   49篇
  2006年   61篇
  2005年   64篇
  2004年   55篇
  2003年   48篇
  2002年   38篇
  2001年   27篇
  2000年   8篇
  1999年   24篇
  1998年   8篇
  1997年   7篇
  1996年   8篇
  1995年   9篇
  1994年   9篇
  1992年   25篇
  1991年   15篇
  1990年   20篇
  1989年   21篇
  1988年   26篇
  1987年   25篇
  1986年   25篇
  1985年   22篇
  1984年   12篇
  1983年   7篇
  1982年   8篇
  1981年   7篇
  1979年   12篇
  1978年   7篇
  1977年   10篇
  1975年   7篇
  1974年   8篇
  1971年   6篇
  1969年   6篇
  1967年   9篇
排序方式: 共有1385条查询结果,搜索用时 15 毫秒
1.

Background

Radium 223 was introduced for metastatic castration-resistant prostate cancer based on the results of a randomized controlled trial showing risk reduction for death and skeletal events. Our aim was to evaluate the outcome of patients receiving radium 223 in a real-world setting.

Patients and Methods

We conducted a multicenter retrospective analysis in the Triveneto region of Italy.

Results

One hundred fifty-eight patients received radium 223 in our region. After a median follow-up of 9.5 months, 75 patients died. The median overall survival (OS) was 14.2 months, and the median progression-free survival (PFS) was 6.2 months. Seventy-one (45%) patients achieved progression as best response. Thirty-seven (23%) patients stopped the treatment early because of progression. Eastern Cooperative Oncology Group performance status was prognostic for OS (18.4 vs. 12.3 vs. 7.5 months; 0 vs. 1, P = .0062; 0 vs. 2, P = .0002), whereas previous prostatectomy or docetaxel exposure were not. A neutrophil to lymphocytes ratio ≥ 3 significantly impacted OS (18.1 vs. 9.7 months; P < .001) and slightly impacted PFS (6.6 vs. 5.6 months; P = .05). Patients with a baseline alkaline phosphatase (ALP) value ≥ 220 U/L had worse OS and PFS (24.1 vs. 10.5 months; 7.2 vs. 5.5 months; P < .001). Patients with changes in ALP value achieved better OS (P = .029) and PFS (P = .002). There was no difference according to the line of therapy (0 vs. ≥ 1; P = .490). The main grade 3/4 toxicities were anemia, asthenia, and thrombocytopenia.

Conclusion

This large real-world report confirms comparable OS and PFS data when compared with the pivotal study, as well as the predictive role of ALP and neutrophil to lymphocytes ratio. The definition of the optimal position of radium 223 in the treatment of metastatic castration-resistant prostate cancer has still to be defined.  相似文献   
2.
Objectives: To illustrate endoscopic techniques used in the treatment of esthesioneuroblastoma and to advocate this method of management followed by radiation therapy in selected cases. Methods: A retrospective case series of 10 patients with esthesioneuroblastomas treated between 1999 and 2004 at a tertiary referral center using endonasal techniques. Results: Mean age of patients at presentation was 56.2 years (median 57 years). Seven patients were female and 3 patients were male. Kadish staging at presentation was: A - 3 patients, B - 5 patients, C - 2 patients. Dulguerov stage at presentation was: T1 - 4 patients, T2 - 4 patients, T3 - 2 patients. The period of follow-up ranged from 11 months to 74 months (mean 38.1 months, median 39 months). To date no recurrence has developed in any patient. Conclusions: Our experience suggests that endoscopic surgery can be an effective method of management. Strict attention to selection criteria, careful surgical techniques, and regular follow-up are key elements for success.  相似文献   
3.
OBJECTIVE: To determine whether hyperinsulinemia has a negative effect on uterine blood supply in patients with polycystic ovary syndrome (PCOS). METHODS: Sixty-three patients with normal body mass index were included prospectively in the study: 48 had clinical and hormonal features of PCOS and 15 were normo-ovulatory. All patients underwent Doppler flow measurement of the uterine artery, and determination of serum concentrations of luteinizing hormone, follicle stimulating hormone, prolactin, estradiol, androgens, insulin and C-peptide during the early follicular phase of the menstrual cycle. The 48 PCOS-patients were divided into two groups according to the pulsatility index (PI) value of the uterine artery: Group 1, PI < 3; Group 2, PI >or= 3 and the groups were compared. RESULTS: The mean PI of the uterine artery (3.01 +/- 1.0 vs. 1.93 +/- 0.3, respectively) and fasting levels of insulin (50.9 +/- 9.3 vs. 40.3 +/- 10.9) and C-peptide (366.9 +/- 118.4 vs. 243.6 +/- 120.3) of PCOS-patients were significantly higher than those of the control group. No correlation was found between insulinemia and C-peptide and PI of the uterine artery and no significant difference was found in insulin and C-peptide levels among the two groups of PCOS-affected patients. Only the serum level of dehydroepiandrosterone sulfate was significantly higher in Group 2, and a direct correlation was found between PI values of the uterine artery and DHEAS plasma levels. CONCLUSION: Insulin and C-peptide do not seem to interfere with uterine perfusion in PCOS-affected patients.  相似文献   
4.
5.
The purpose of this study was threefold: to evaluate the role of gallium-67 scintigraphy in the staging of low-grade non-Hodgkin’s lymphomas (LGNHL), to assess the relationship between the expression of CD71 on the surface of the neoplastic cells and the 67Ga uptake by the tumour, and to establish the contribution of 67Ga scan in defining the prognosis of LGNHL. Forty-eight patients with untreated LGNHL diagnosed in a single institution over a decade were reviewed. The end point of the study was survival of the patients according to the scintigraphic 67Ga score at diagnosis. In addition to 67Ga scan, other prognostic variables were studied, relating to the neoplastic burden, the biology of the tumour and the host. Univariate and multivariate analyses were used. 67Ga scan identified only 116/286 (41%) nodes involved by lymphoma that were detected by clinical examination or computed tomography scan. A scintigraphic scoring system with an arbitrary cut-off value of 3 (high scan score) was able to predict patients with a dismal prognosis: with a mean follow-up of 47 months (range: 1–146 months) the median survival time was 28 months in patients with a high scan score and 74 months in patients with a low scan score (P=0.002). CD71 values were 27.4%±14.9% (mean ±SD) in the former and 8.9%±7.2% in the latter (P=0.0001). Only performance status and extranodal sites were significant variables for prognosis in multivariate analysis. It is concluded that 67Ga scan is inaccurate in staging but might be very important in defining the prognosis in LGNHL, in association with other prognostic variables. Received 1 May and in revised form 6 August 1997  相似文献   
6.
A pregnancy obtained in a patient with 46XY gonadal dysgenesis (Swyer's syndrome) after ovum donation and IVF/ET is described. The efficacy of this technique in overcoming particular cases of otherwise irreversible infertility is discussed.  相似文献   
7.
OBJECTIVE: To investigate the association between the use of fluoroquinolone agents and the risk of tendinitis in a large population-based case-control study. METHODS: The study was performed by linking automated health databases from the Region of Lombardia, Italy. Cases were patients aged > or =18 years who had a hospital discharge diagnosis of non-traumatic tendinitis in 2002-3. For each case, up to five controls were randomly selected among those eligible for inclusion in the study. A conditional logistic regression model was used to estimate the odds ratio of tendinitis associated with the current, recent and past use of fluoroquinolones. Odds ratios were adjusted for exposure to other antibacterials and other drugs. RESULTS: 22,194 cases and 104,906 controls met the inclusion criteria. Current use of fluoroquinolones significantly increased the risk of tendon disorders as a whole (odds ratio [OR] = 1.7; 95% CI 1.4, 2.0), tendon rupture (OR = 1.3; 95% CI 1.0, 1.8) and rupture of the Achilles' tendon (OR = 4.1; 95% CI 1.8, 9.6). Concomitant use of corticosteroids and fluoroquinolones increased the risk of both tendon rupture (OR = 3.1; 95% CI 1.5, 6.3) and rupture of the Achilles' tendon (OR = 43.2; 95% CI 5.5, 341.1). DISCUSSION: Evidence that exposure to fluoroquinolones is associated with the sudden occurrence of tendinitis is supported by this large population-based study. We can estimate that a single case of rupture of the Achilles' tendon would occur for every 5958 persons treated with fluoroquinolones (95% CI 2148, 23,085). The corresponding number needed to harm is 979 (95% CI 122, 9172) for patients who concomitantly use corticosteroids and 1638 (95% CI 351, 8843) for those aged >60 years. CONCLUSION: Clinicians should be aware of this adverse effect, and the increased risk for fluoroquinolone-associated tendinitis in elderly patients with corticosteroid use must be considered when these agents are prescribed.  相似文献   
8.
OBJECTIVE: The present study tested the hypothesis that the serum copper abnormalities were correlated with alterations of resting electroencephalographic (EEG) rhythms across the continuum of healthy elderly (Hold), mild cognitive impairment (MCI), and AD subjects. METHODS: Resting eyes-closed EEG rhythms delta (2-4Hz), theta (4-8Hz), alpha 1 (8-10.5Hz), alpha 2 (10.5-13Hz), beta 1 (13-20Hz), beta 2 (20-30Hz), and gamma (30-40Hz), estimated by LORETA, were recorded in 17 Hold, 19 MCI, 27 AD- (MMSE< or =20), and 27 AD+ (MMSE20) individuals and correlated with copper biological variables. RESULTS: Across the continuum of Hold, MCI and AD subjects, alpha sources in parietal, occipital, and temporal areas were decreased, while the magnitude of the delta and theta EEG sources in parietal, occipital, and temporal areas was increased. The fraction of serum copper unbound to ceruloplasmin positively correlated with temporal and frontal delta sources, regardless of the effects of age, gender, and education. CONCLUSIONS: These results sustain the hypothesis of a toxic component of serum copper that is correlated with functional loss of AD, as revealed by EEG indexes. SIGNIFICANCE: The present study represents the first demonstration that the fraction of serum copper unbound to ceruloplasmin is correlated with cortical delta rhythms across Hold, MCI, and AD subjects, thus unveiling possible relationships among the biological parameter, advanced neurodegenerative processes, and synchronization mechanisms regulating the relative amplitude of selective EEG rhythms.  相似文献   
9.
Penicillin acylase (EC 3.5.1.11) from E. coli, both in solution and immobilized on solid supports, has been commercially exploited for the large scale production of 6-aminopenicillanic acid (6-APA), which is an important intermediate for the manufacturing of semisynthetic penicillins. In this paper a very simple procedure of penicillin acylase purification is reported, which employs only one affinity chromatographic step (Sepharose-phenylacetic column). The enzyme was obtained at a high degree of purity and could be used for immobilization on partially hydrolyzed and activated nylon. Since the support is chemically inert and mechanically stable the catalyst can be used several times without any significant loss of activity, making the process of great commercial importance.  相似文献   
10.
From January 1988 to December 1991, 55 elderly patients (14 pretreated and 41 previously untreated) with non-Hodgkin's lymphoma (NHL) entered a prospective study to evaluate the feasibility of a combination of mitoxantrone (7-9 mg/m2), VP 16-213 (150 mg, 2-hour infusion on day 1, and 200 mg per os on days 3 and 5) and low-dose prednisone (25 mg days 1-5) (MVP regimen), recycling every 21-28 days. The median age was 75 (range 64-93). All but 4 pretreated patients had intermediate- or high-grade lymphomas. Complete remissions were obtained in 22 of 40 (55%) evaluable previously untreated patients, and partial remissions in 10 (2 of these obtained complete remissions after radiotherapy), for an overall response rate of 80%. The median duration of response was 12 months. At 24 months the overall survival was 52% and the relapse-free survival was 31%. Of 14 pretreated patients complete remissions were obtained in 4 (29%) and partial remissions in 3. Granulocytopenia and fever were the most important side effects; two patients contracted bronchopneumonia and one of them died. Other toxicities were mild. We conclude that this combination chemotherapy is effective as first-line and salvage treatment in elderly patients with intermediate- and high-grade NHL, and that it is feasible on an outpatient basis, with manageable toxicity.  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