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   2287篇
  免费   26篇
  国内免费   1篇
耳鼻咽喉   13篇
儿科学   65篇
妇产科学   41篇
基础医学   227篇
口腔科学   57篇
临床医学   153篇
内科学   533篇
皮肤病学   39篇
神经病学   137篇
特种医学   29篇
外科学   360篇
综合类   1篇
一般理论   4篇
预防医学   394篇
眼科学   34篇
药学   64篇
中国医学   8篇
肿瘤学   155篇
  2023年   13篇
  2022年   36篇
  2021年   71篇
  2020年   25篇
  2019年   491篇
  2018年   295篇
  2017年   163篇
  2016年   22篇
  2015年   27篇
  2014年   39篇
  2013年   56篇
  2012年   27篇
  2011年   35篇
  2010年   32篇
  2009年   33篇
  2008年   47篇
  2007年   30篇
  2006年   30篇
  2005年   35篇
  2004年   22篇
  2003年   29篇
  2002年   19篇
  2001年   29篇
  2000年   21篇
  1999年   13篇
  1998年   13篇
  1997年   11篇
  1996年   10篇
  1995年   14篇
  1994年   10篇
  1993年   12篇
  1992年   12篇
  1991年   7篇
  1990年   4篇
  1989年   5篇
  1988年   8篇
  1987年   3篇
  1985年   62篇
  1984年   107篇
  1983年   69篇
  1982年   71篇
  1981年   55篇
  1980年   57篇
  1979年   51篇
  1978年   24篇
  1977年   16篇
  1976年   20篇
  1975年   14篇
  1974年   11篇
  1973年   7篇
排序方式: 共有2314条查询结果,搜索用时 15 毫秒
21.
Linkage of epidemiological registries can provide cost-effective information on the associations between different diseases or exposures in the population under study and on completeness of surveillance system databases. We describe the program SALI (software for automated linkage in Italy) aimed at matching individual records from medium-sized registries (in the order of 100,000 records), where the desired outcome is to miss as few links as possible and, because of low link-likelihood (< 1%), a manual revision of matched pairs is feasible. SALI, developed in CA-Clipper language, uses registry files in dBase format. It requires only name, surname, and date of birth as key fields, and it allows for spelling errors in Italian or other Latin languages through a specific algorithm. Furthermore, a double-blind procedure ensures data confidentiality. The main linkage procedure is based on four stages, two automatic ones, and two where the operator can decide through specific windows whether to accept stage-selected matches. SALI takes into account possible errors in key fields thus reducing false negatives. It was used to solve the problem of linkage between AIDS and cancer registries in Italy. It can be used with every IBM-compatible computer system, assuring uniquely high portability.  相似文献   
22.
Chromosome investigations were carried out in 7 patients with Fanconi's anemia, type Estren-Dameshek. The frequency and types of chromosome instability found in cultured lymphocytes were in accord with those detected in individuals with classical Fanconi's anemia. The break-point distribution indicates a significant excess of breaks in chromosomes No. 1, 2, and 7 and a deficit in No. 18 and X and Y chromosomes. There was a clear clustering of breaks at certain locations in chromosomes No. 1, 2, 3, 7, 9, and 14. The location of the breaks with respect to the bands demonstrated an almost exclusive involvement of the lighter bands, regardless of the banding method used. These results suggest that most breaks take place in the interbands between the G and R bands. In all patients, chromosome instability was less frequent in direct bone marrow preparations than in lymphocyte cultures. However, cultured bone marrow cells showed a significant increase of chromosome aberrations. On the whole, the chromosome data derived from this series of patients are in agreement with those obtained in individuals with classical Fanconi's anemia and give no support to the idea of cytogenetic heterogeneity between subjects affected by these two forms of childhood aplastic anemia.  相似文献   
23.
No clinical reports of blastomycosis in Italy have been published until now. We here report two cases of histologically diagnosed, unexpected cutaneous involvement in patients, aged 78 and 52 years, living in North Italy and never having been abroad. The histological differential diagnosis between blastomycosis and other fungal pathogens is discussed. Even in the absence of culture the present cases can confidently be considered as genuine examples of Blastomyces dermatitidis infection in Italy.  相似文献   
24.
The tumor promoting agent TPA (phorbol ester; 1.6 X 10(-8)M) was used to induce the differentiation in vitro of B-chronic lymphocytic leukemia (B-CLL) cells from 14 untreated patients. The uninduced phenotype was SIg+, Mrbc+, RFT-1+, RFA-4-, FMC7-. After 72 h incubation with TPA, B-CLL cells became RFA-4+, FMC7+ and lost the capability of Mrbc rosetting. Large proportions of the "induced" cells also showed morphological and ultrastructural changes, such as undulating membranes and bleblike protusions and became strongly positive for tartrate resistant acid phosphatase (TRAP+) and also contained cytoplasmic immunoglobulins. These features are very similar to the features of hairy cell leukemia (HCL). These observations confirm previous clinical findings that B-CLL and HCL are related disorders of the B lineage. The development of "hairy" features in induced B-CLL and in HCL seems to be a malignancy-associated feature because the Mrbc+ normal B cells (B-CLL-equivalent cells) isolated from tonsil also develop TRAP positivity but no membrane aberrations.  相似文献   
25.
Background: Coronavirus disease 2019 (COVID-19) causes not only severe illness but also detrimental effects associated with the lockdown measures. The present study aimed to evaluate reported lifestyle changes in a cohort of adults in Italy, including physical exercise, food choices, and psychological wellbeing, after two months of lockdown. Methods: A web survey on social media (Facebook and LinkedIn) of 32 multiple-choice questions aiming to evaluate the impact of the national COVID-19 lockdown in a sample of Italian adults. Results: We received 1378 complete responses (women 68.3%, mean age 39.5 ± 12.5 years). The percentage of participants reporting regular exercise decreased during lockdown (52 vs. 56.5%). The vast majority of people continued to consume the three traditional meals per day, but the consumption of meat, fish, and eggs significantly decreased. Women reported more frequent anxiety, sadness, fear, and feelings of insecurity than men. The factors predicting the worst outcome during the lockdown were being a woman, low education and income, gastrointestinal diseases. Conclusion: The lockdown has had a limited impact on food choices and physical exercise in Italian adults of our series, since most of them made an effort to improve their lifestyle. However, women with gastrointestinal diseases reported more frequent negative feelings and poor adaptation to the lockdown.  相似文献   
26.
《Value in health》2021,24(9):1273-1278
ObjectiveThe main objective of this study was to evaluate the potential role of efficacy data and other information available at the time of price and reimbursement (P&R) decision-making process within the definition of oncology treatment costs in Italy.MethodsThe study included all P&R dossiers submitted to the Italian Medicines Agency between July 2015 and December 2017. It prospectively collected the data of the P&R process starting from dossier submission up to the Italian Health Service reimbursement decision. The cost of treatment per patient was estimated using both the list price (“gross cost”) and the confidential net price (“net cost”) of drug packages and applied to the median duration of treatment. A 2-sample stage Heckman decomposition model was used to evaluate the potential role of efficacy data and other information available at the time of P&R decision making on the gross and net cost.ResultsA total of 37 oncology drugs related to 58 therapeutic indications were analyzed. The multivariate model showed that the variation of progression-free survival is the only variable predictor statistically associated with treatment cost, but this effect was observed only when confidential net prices were used (P=.026).ConclusionsConsidering the perspective of a developed country having a public healthcare service with a central reimbursement negotiation is determined a relevant reduction in the treatment cost purchased by public payers. This is a useful approach to guarantee the affordability of innovative oncology drugs and to contain public expenditures on healthcare. Furthermore, the negotiation of confidential discounts and agreement clauses in managed entry agreements seemed to reward oncology drugs displaying an added therapeutic benefit.  相似文献   
27.
We measured severe acute respiratory syndrome coronavirus 2 spike protein subunits S1/S2 antibodies by using capillary electrophoresis and a chemiluminescence immunoassay for 5,444 active healthcare workers in Italy. Seroprevalence was 6.9% and higher among participants having contact with patients. Seroconversion was not observed in 37/213 previously infected participants.  相似文献   
28.
Shiga toxin–producing Escherichia coli (STEC) O80:H2 has emerged in Europe as a cause of hemolytic uremic syndrome associated with bacteremia. STEC O80:H2 harbors the mosaic plasmid pR444_A, which combines several virulence genes, including hlyF and antimicrobial resistance genes. pR444_A is found in some extraintestinal pathogenic E. coli (ExPEC) strains. We identified and characterized 53 STEC strains with ExPEC-associated virulence genes isolated in Italy and the Netherlands during 2000–2019. The isolates belong to 2 major populations: 1 belongs to sequence type 301 and harbors diverse stx2 subtypes, the intimin variant eae-ξ, and pO157-like and pR444_A plasmids; 1 consists of strains belonging to various sequence types, some of which lack the pO157 plasmid, the locus of enterocyte effacement, and the antimicrobial resistance–encoding region. Our results showed that STEC strains harboring ExPEC-associated virulence genes can include multiple serotypes and that the pR444_A plasmid can be acquired and mobilized by STEC strains.  相似文献   
29.
30.
A case of infant botulism in a 9 week-old female is described. A strain of C. botulinum type B was isolated from the feces of the baby. The epidemiologic study detected in a sample of home canned honey Clostridium botulinum spores of the same serotype that was isolated from the patient. The honey had been used only to sweeten the pacifier of the baby. This is the first case of infant botulism in Europe linked conclusively to honey.Corresponding author.  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