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   1122篇
  免费   61篇
  国内免费   1篇
耳鼻咽喉   6篇
儿科学   33篇
妇产科学   22篇
基础医学   146篇
口腔科学   32篇
临床医学   73篇
内科学   359篇
皮肤病学   4篇
神经病学   84篇
特种医学   29篇
外科学   85篇
综合类   4篇
一般理论   2篇
预防医学   96篇
眼科学   5篇
药学   79篇
肿瘤学   125篇
  2022年   11篇
  2021年   22篇
  2020年   14篇
  2019年   14篇
  2018年   15篇
  2017年   13篇
  2016年   22篇
  2015年   18篇
  2014年   32篇
  2013年   33篇
  2012年   70篇
  2011年   61篇
  2010年   23篇
  2009年   28篇
  2008年   53篇
  2007年   42篇
  2006年   53篇
  2005年   53篇
  2004年   41篇
  2003年   45篇
  2002年   35篇
  2001年   38篇
  2000年   31篇
  1999年   43篇
  1998年   15篇
  1997年   8篇
  1996年   10篇
  1995年   11篇
  1994年   13篇
  1993年   10篇
  1992年   38篇
  1991年   24篇
  1990年   21篇
  1989年   28篇
  1988年   17篇
  1987年   27篇
  1986年   21篇
  1985年   23篇
  1984年   14篇
  1983年   18篇
  1982年   7篇
  1981年   6篇
  1979年   16篇
  1978年   7篇
  1976年   4篇
  1974年   9篇
  1972年   3篇
  1971年   3篇
  1970年   3篇
  1966年   4篇
排序方式: 共有1184条查询结果,搜索用时 15 毫秒
21.
The authors reviewed records of admission at the Fist Ais-Emergency Service of "G. Gaslini" Children's Hospital, data referring both to in and outpatients. First of all we took into account epidemiological data analysing occurrence and types of diseases; at the same time a demographic study, which aimed to show a decrease in the child population in Genova, was performed. Secondly we compared these data with the real number of admitted patients: collected data showed that this service has been used excessively.  相似文献   
22.
A new method for intraperitoneal tumour targetting in ovarian cancer using biotinylated monoclonal antibodies (MoAb) and radioactive streptavidin is described. Fifteen patients with histologically documented ovarian carcinoma were injected intraperitoneally with 2 mg of biotinylated MoAb MOv18, followed 3–5 days later by 100–150 g of indium-111 streptavidin, at the specific activity of 280–370 MBq/mg in 500 ml of normal saline. No toxicity was observed. Tumours were imaged from 2 to 48 h after radioactivity injection by recording both planar and single photon emission tomography (SPET) data. All patients underwent surgery 1–8 days later (mean 3 days) after scanning. The resected tumour and normal tissue radioactivity were measured. On the day of surgery, the tumour to normal tissue ratio was 9:1 (range 3:1–30:1) and 45:1 (range 12:1–120:1) for intra- and extraperitoneal samples, respectively. The mean tumor to blood ratio was 14:1 (range 4:1–30:1). The injected dose (i.d.) per gram of tumour was 0.112 (range 0.01–0.3) for recurrences and 0.05 for primary tumour (range 0.005–0.2). Over 24–48 h 14% i.d. (range 8–18% i.d.) was found in the urine, 14% i.d. (range 629% i.d.) in the blood and 63% i.d. (range 56–70% i.d.) was still in the peritoneal cavity. These preliminary clinical data suggest that this two-step strategy may be superior to the conventional approach (radiolabelled antibodies) for intraperitoneal radioimmunolocalization and radioimmunotherapy of ovarian cancer. Offprint requests to: G. Paganelli  相似文献   
23.
Radioactive antibodies that react with tumour-associated antigens to "tag" antigen-positive tumour cell deposits were given to 20 patients with primary or recurrent colorectal cancer. The tumour associated antigen TAG 72-specific monoclonal antibody B72.3 labelled with 125-Iodine was used, and the radioactivity in the tumour was sought during operation with a hand-held gamma detecting probe. Tumour was detected by the probe in 7 of 15 patients with primary cancer, with a mean tumour: normal tissue ratio of 3.9, and in 4 of 5 patients with recurrent disease, with a mean tumour: normal tissue ratio of 2.0. Immunohistochemical analysis of surgical specimens confirmed the results of the intraoperative detection. The incidence of TAG 72-positive tumours (11/20, 55%), detected by immunohistochemistry, was lower than the 80% in the other series, possibly because of sampling errors or because the cases studied were uncomplicated with small primary tumours. Results obtained with the probe were instrumental in modifying the operation in two of the four "positive" patients with recurrences, allowing the removal of tumour masses that would otherwise have been overlooked.  相似文献   
24.
BACKGROUND: Hypermethylation is studied as a new, relevant mechanism for silencing tumor suppressor genes. It is a potentially reversible epigenetic change and it is the target of novel anticancer compounds with demethylating activity. In this perspective, we investigated E-cadherin gene (CDH1) promoter hypermethylation in gastric carcinomas and its correlation with E-cadherin protein expression. METHODS: Consecutive cases of gastric carcinoma with assessable paraffin-embedded tumor blocks and paired normal mucosa were considered eligible for study entry. CDH1 promoter hypermethylation and E-cadherin protein expression were determined by methylation-specific polymerase chain reaction and immunohistochemistry, respectively. RESULTS: CDH1 promoter hypermethylation was found in 20 out of 70 gastric carcinomas and the epigenetic change occurred in the early, as well as in the locally advanced disease. In five cases, hypermethylation was also detected in the normal mucosa. Eighteen out of 20 hypermethylated tumors were of the diffuse histotype (P=0.0001). Of 24 tumors with reduced or negative E-cadherin expression, 19 were hypermethylated and 5 were unmethylated (P=0.0001). CONCLUSIONS: CDH1 promoter hypermethylation frequently occurs in gastric carcinomas of the diffuse histotype and it is significantly associated with downregulated E-cadherin expression. The knowledge on the hypermethylation status of tumor suppressor genes may be relevant to the development of demethylating drugs and novel chemopreventive strategies in solid tumors.  相似文献   
25.
The authors report their experience in a retrospective study on a sample year (1997) of cases (77 in number) of lateral epicondylitis treated non-surgically at the Rizzoli Orthopaedic Institute. The results for the 63 patients reviewed are very disappointing (healing only in 36.5% of cases). In their opinion, this may be attributed to the lack of an accurate clinical definition of the pathology, and an inadequate treatment protocol. They conclude with the proposal to classify 3 clinical forms for epicondylitis (acute, chronic recurrent, and chronic persistent) and to follow a corresponding treatment protocol, aimed at improving results.  相似文献   
26.
BACKGROUND AND PURPOSE: The objectives of the current study were to compare genito-urinary (GU) and gastro-intestinal (GI) toxicities as well as biochemical control (bRFS) in prostate cancer, utilizing conventional (2.0 Gy daily) (STD) or hyperfractionated (HFX) conformal irradiation (CRT). HFX (1.2 Gy BID) was chosen as a radiobiological method to try to reduce long term sequelae without compromising local control. PATIENTS AND METHODS: Three-hundred-and-seventy consecutive patients (pts) entered this prospective, non-randomized trial in the period January 1993-January 2003; 209 were treated with STD and 161 with HFX CRT. All were evaluable for acute toxicity analysis, 179 (STD) and 151 pts (HFX) being evaluable for late sequelae and bRFS analyses. Pt characteristics were not statistically different in the two groups. CRT consisted of a 4-field technique for prostate and/or pelvic nodes and a 5-field boost with rectal shielding. Median doses were 74 and 79.2 Gy for STD and HFX patients respectively, the latter dose being isoeffective for tumour control assuming alpha/beta=10 (EQD(2)=73.9 Gy). Median follow-up was 29.4 months (25.2 mos for STD; 37.7 mos for HFX; P<0.01). The two regimens were compared in terms of acute and late GU and GI toxicities and 5-year bRFS by univariate and multivariate analyses. RESULTS: Acute grade> or =2 GU toxicity was higher in the STD group (48.6% versus 37.3% in HFX, P=0.03), while no significant difference was found for acute GI toxicity. Late grade> or =2 GU and GI toxicities were lower in the HFX group (5-year actuarial rate: GU: 10.1% versus 20.3%, P=0.05; GI: 6.0% versus 10.6%, P=0.18). Five-year bRFS were 70% (+/-13.8%, 95% CI) and 82.6% (+/-7.2%) for STD and HFX, respectively (P=0.44); a trend favouring HFX was found in the subgroup of pts who did not receive hormonal therapy (5-year bRFS: 85.9%+/-12.4% versus 63.9%+/-23.8%, P=0.15). Multivariate analysis revealed only risk groups and age statistically related to bRFS but not fractionation regimen. Using the Nahum-Chapman TLCP model and prostate parameter set, which includes hypoxia, the TLCPs are approximately equal for the two regimens, whereas assuming alpha/beta=1.5 and no hypoxia we obtain 73% for the STD group but only 36% for the HFX group. CONCLUSIONS: As expected from radiobiological considerations, HFX reduces GI and GU late toxicities. Concerning early bRFS, our clinical findings suggest that HFX is no less effective than STD when delivering an isoeffective (alpha/beta=10) dose. Despite the relatively short follow-up, this result appears to be inconsistent with a low alpha/beta ratio for prostate cancer.  相似文献   
27.
A 1H and 13C NMR study on the inclusion complex of paroxetine with β-cyclodextrin was carried out in order to define the stoichiometry of the association and its strength. Proton and carbon chemical shift measurements of paroxetine and β-cyclodextrin were performed at several molar ratios and temperatures, allowing the determination of a 1:1 stoichiometry and an association constant value of the order of 2 × 103 for the paroxetine–β-cyclodextrin complex. Overhauser effects in the rotating frame were also measured, and the experimental interproton distance constraints have been used for molecular model building of the complex. The obtained model indicates that the benzodioxolyl moiety of paroxetine is deeply inserted in the cavity of the cylindrical structure of β-cyclodextrin, while the fluoro-phenyl ring lays above the wider rim.  相似文献   
28.
A 14-month-old child who had a haemolytic episode when he was 5 years old, and with psychomotor retardation, was found to have decreased red cell hexokinase activity. The mutant enzyme was characterized by an increased affinity for glucose associated with an increased inhibition constant for glucose-1,6-diphosphate. Affinity for Mg ATP2-, heat stability and pH-optimum were normal. The isozymic pattern of the red cell enzyme was normal but all the molecular forms were present in reduced amounts. The kinetics of decay of hexokinase during cell ageing was also normal. Glucose consumption of the hexokinase deficient cells was 60-65% of the controls while the amount metabolized through the hexose monophosphate shunt was unchanged. Red cell 2,3-diphosphoglycerate and glucose-6-phosphate levels were normal in the proband but reduced in the erythrocytes of his parents, who were heterozygous for the defect but had normal haematological data. Comparison with the 13 previously reported cases of hexokinase deficiency confirms the broad phenotypic variability that characterizes this disorder.  相似文献   
29.
Introduction: TNF-α is a pro-inflammatory cytokine known to a have a key role in the pathogenesis of chronic immune-mediated diseases. TNF-α inhibitors can be administered either as monotherapy or in combination with other anti-inflammatory or disease-modifying anti-rheumatic drugs (DMARDs) to treat chronic immune-mediated diseases.

Areas covered: Patients receiving TNF-α inhibitors are at high risk of infections. Based on our experience, in this paper, we discuss the risk of infections associated with the administration of TNF-α inhibitors and the strategies for mitigating against the development of these serious adverse events.

Expert opinion: Infliximab more so than etanercept appears to be responsible for the increased risk of infections. Re-activation of latent tuberculosis (LTB) infection and the overall risk of opportunistic infections should be considered before beginning TNF-α inhibitor therapy. A careful medical history, Mantoux test and chest-x-ray should always be performed before prescribing TNF-α inhibitors. Particular attention should be paid to risk factors for Pneumocystis jirovecii infection. Hepatitis B and C virological follow-up should be considered during TNF-α inhibitor treatment. Finally, patients who are at high risk of herpes zoster (HZ) reactivation would benefit from a second vaccination in adulthood when receiving TNF-α inhibitors.  相似文献   

30.
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