全文获取类型
收费全文 | 15505篇 |
免费 | 875篇 |
国内免费 | 148篇 |
专业分类
耳鼻咽喉 | 96篇 |
儿科学 | 334篇 |
妇产科学 | 242篇 |
基础医学 | 1830篇 |
口腔科学 | 378篇 |
临床医学 | 1339篇 |
内科学 | 4797篇 |
皮肤病学 | 183篇 |
神经病学 | 1544篇 |
特种医学 | 610篇 |
外科学 | 2177篇 |
综合类 | 30篇 |
预防医学 | 522篇 |
眼科学 | 136篇 |
药学 | 776篇 |
中国医学 | 9篇 |
肿瘤学 | 1525篇 |
出版年
2023年 | 129篇 |
2022年 | 214篇 |
2021年 | 412篇 |
2020年 | 289篇 |
2019年 | 350篇 |
2018年 | 412篇 |
2017年 | 337篇 |
2016年 | 413篇 |
2015年 | 439篇 |
2014年 | 608篇 |
2013年 | 819篇 |
2012年 | 1168篇 |
2011年 | 1223篇 |
2010年 | 672篇 |
2009年 | 695篇 |
2008年 | 1070篇 |
2007年 | 1144篇 |
2006年 | 1042篇 |
2005年 | 1022篇 |
2004年 | 1004篇 |
2003年 | 817篇 |
2002年 | 731篇 |
2001年 | 115篇 |
2000年 | 102篇 |
1999年 | 112篇 |
1998年 | 126篇 |
1997年 | 127篇 |
1996年 | 93篇 |
1995年 | 87篇 |
1994年 | 72篇 |
1993年 | 77篇 |
1992年 | 60篇 |
1991年 | 74篇 |
1990年 | 47篇 |
1989年 | 33篇 |
1988年 | 34篇 |
1987年 | 39篇 |
1986年 | 44篇 |
1985年 | 29篇 |
1984年 | 45篇 |
1983年 | 32篇 |
1982年 | 20篇 |
1981年 | 18篇 |
1980年 | 15篇 |
1979年 | 12篇 |
1978年 | 11篇 |
1972年 | 9篇 |
1968年 | 8篇 |
1967年 | 12篇 |
1966年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Emanuele DAmico Aurora Zanghì Marzia Romeo Eleonora Cocco Giorgia Teresa Maniscalco Vincenzo Brescia Morra Damiano Paolicelli Giovanna De Luca Simonetta Galgani Maria Pia Amato Giuseppe Salemi Matilde Inglese Paolo Agostino Confalonieri Giacomo Lus Carlo Avolio Antonio Gallo Marika Vianello Marco Onofrj Massimo Filippi Maria Trojano Francesco Patti 《Neurotherapeutics》2021,18(2):905
The current study aims to compare injectable and oral first-line disease-modifying therapies (DMTs) for time to first relapse, time to confirmed disability progression (CDP), and time to discontinuation using a cohort of relapsing remitting multiple sclerosis (RRMS) patients, with data extracted from the Italian MS Register. This multicenter, observational, retrospectively acquired, and propensity-adjusted cohort study utilized RRMS-naïve patients from the Italian MS Register who started either injectable or oral first-line DMTs between January 1, 2010, and December 31, 2017, to evaluate the impact on disability outcomes in patients. Enrolled patients were divided into two groups, namely the injectable group (IG) and the oral group (OG). Of a cohort of 11,416 patients, 4602 were enrolled (3919 in the IG and 683 in the OG). The IG had a higher rate of women (67.3% vs 63.4%, p < 0.05) and a lower mean age (36.1 ± 10.9 vs 38.9 ± 11.8, p < 0.001). The event time to first relapse demonstrated a lower risk in the OG (HR = 0.58; CI 95% 0.48–0.72, p < 0.001). However, no differences were found between the two groups with respect to the risk of CDP (HR = 0.94; CI 95% 0.76–1.29, p = 0.941), while a lower risk of DMT was found in the OG (HR = 0.72; CI 95% 0.58–0.88, p = 0.002) for the event time to discontinuation. Real-world data from the Italian MS Register suggests that first-line oral DMTs are associated with a lower risk of experiencing a new relapse and of therapy discontinuation compared to injectable DMTs.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13311-020-01001-6.Key Words: Multiple sclerosis, injectable DMTs, oral DMTs, real-world setting, EDSS score 相似文献
992.
Substance abuse and psychopathology 总被引:1,自引:0,他引:1
Massimo Clerici Italo Carta Carlo Lorenzo Cazzullo 《Social psychiatry and psychiatric epidemiology》1989,24(4):219-226
This report evaluates, using DSM III, the psychopathological profile of 226 heroin users taken in at the clinical centre of "Cascina Verde" Therapeutic Community (Milan, Italy) and admitted to a psychotherapeutic, retraining, integrated, both out-and-in-patient treatment. The outcome shows that 30% of subjects are to be diagnosed according to Axis I while 61% are to be considered among Axis II personality disorders. A portion of 16% is to be referred to the "schizophrenic spectrum", 25% has histrionic, narcissistic, antisocial and borderline personality disorders and the remaining are to be referred to an extremely heterogeneous category. The report shows also data concerning Axes IV and V, always according DSM III. 相似文献
993.
Silvano Bosari Massimo Roncalli Giuseppe Viale Paola Bossi Guido Coggi 《The Journal of pathology》1993,169(4):425-430
Immunoreactivity for the tumour suppressor gene product p53 is commonly found in many different human malignancies and few premalignant lesions. Data on cervical neoplasms, however, are still lacking. We retrospectively investigated p53 immunoreactivity in 92 lesions of the uterine cervix, including 44 cases of chronic cervicitis, 29 squamous intraepithelial lesions (SILs), and 19 invasive carcinomas. p53 immunoreactivity confined to the basal cell layer, was detected in 74 per cent of cases showing chronic cervicitis and in all cases with low-grade SILs. Conversely, suprabasal and/or diffuse p53 immunoreactivity was exclusively demonstrated in 25 per cent of high-grade SILs and in 74 per cent of invasive carcinomas. The results of this investigation document a high prevalence of p53-immunoreactive malignant tumours of the uterine cervix. In high-grade SILs, p53-immunoreactive cells paralleled the height of involvement by dysplastic changes within the squamous epithelium. A prolonged half-life of the protein is the most likely explanation for the occurrence of p53 immunoreactivity in neoplastic cells. The unexpected finding of p53-immunoreactive cells in inflammatory lesions, though possibly related to an increased proliferation rate of the basal cell compartment, requires further study and underlines the need for a careful approach to p53 immunocytochemistry. 相似文献
994.
Soluble HLA-A,-B,-C and -G molecules induce apoptosis in T and NK CD8+ cells and inhibit cytotoxic T cell activity through CD8 ligation 总被引:21,自引:0,他引:21
Contini P Ghio M Poggi A Filaci G Indiveri F Ferrone S Puppo F 《European journal of immunology》2003,33(1):125-134
There is convincing evidence that soluble HLA-A,-B,-C (sHLA-A,-B,-C) and soluble HLA-G (sHLA-G) antigens can induce apoptosis in CD8(+) activated T cells although there is scanty and conflicting information about the mechanism(s) by which sHLA-A,-B,-C antigens and sHLA-G antigens induce apoptosis. In this study we have compared the apoptosis-inducing ability of sHLA-A,-B,-C antigens with that of sHLA-G1 antigens in CD8(+) T lymphocytes and CD8(+) NK cells. Furthermore we have compared the inhibitory effect of sHLA-A,-B,-C antigens and of sHLA-G1 antigens on the activity of EBV-specific CD8(+) cytotoxic T lymphocytes (CTL). sHLA molecules were purified from serum and from the supernatant of HLA class I-negative cells transfected with one gene encoding either classical or non-classical HLA class I antigens. Both classical and non-classical sHLA class I molecules trigger apoptosis in CD8(+) T lymphocytes and in CD8(+) NK cells, which lack the T cell receptor, and their apoptotic potency is comparable. The binding of sHLA-A,-B,-C and sHLA-G1 molecules to CD8 leads to Fas ligand (FasL) up-regulation, soluble FasL (sFasL) secretion and CD8(+) cell apoptosis by Fas/sFasL interaction. Moreover, classical and non-classical sHLA class I molecules inhibit the cytotoxic activity of EBV-specific CD8(+) CTL. As the amount ofsHLA-G molecules detectable in normal serum is significantly lower than that of sHLA-A,-B,-C molecules, the immunomodulatory effects of sHLA class I molecules purified from serum are likely to be mainly attributable to classical HLA class I antigens. As far as the potential in vivo relevance of these findings is concerned, we suggest that classical sHLA class I molecules may play a major immunoregulatory role in clinical situations characterized by activation of the immune system and elevated sHLA-A,-B,-C serum levels. In contrast, non-classical HLA class I molecules may exert immunomodulatory effects in particular conditions characterized by elevated sHLA-G levels such as pregnancy and some neoplastic diseases. 相似文献
995.
996.
997.
Conforti L Dell'Agnello C Calvaresi N Tortarolo M Giorgini A Coleman MP Bendotti C 《Journal of neuroscience research》2003,71(5):732-739
The kinesin superfamily motor protein Kif1B is expressed in two isoforms, Kif1Balpha and Kif1Bbeta, with distinct cargo-binding domains. We examined the mRNA distribution of the two isoforms in adjacent sections of brain and spinal cord of adult mice using in situ hybridization analysis. Kif1Bbeta mRNA is enriched in several regions of brain and spinal cord. Its levels are four to five times higher than that of the alpha isoform, which was barely detectable. The highest mRNA levels of Kif1Bbeta were found in the cortex, hippocampus, cerebellum and the grey matter of the spinal cord. At the cellular level the highest signal was found in motor neurons in the motor nuclei of medulla oblongata and the ventral horn of spinal cord. Because expression of other Kif genes is altered in amyotrophic lateral sclerosis (ALS) models, we examined the expression level of Kif1Bbeta mRNA in the spinal cord of transgenic mice carrying the SOD1G93A mutation, a model of familial ALS, at presymptomatic and early stages of the disease. No changes were observed in Kif1Bbeta mRNA in motor neurons or in other regions of the spinal cord. These findings indicate that Kif1Balpha, which modulates the transport of mitochondria, may play a major role in tissues other than the central nervous system. Instead Kif1Bbeta, responsible for the transport of synaptic vesicle precursors, seems to play an important role in the nervous system, particularly in the lower motor neurons. The absence of changes of Kif1Bbeta mRNA in transgenic SOD1G93A mice suggests that other molecular mechanisms may play a role in the disruption of axonal transport occurring in the motor neurons of these mice. 相似文献
998.
Jennifer Wheler Apostolia M. Tsimberidou Stacy Moulder Massimo Cristofanilli David Hong Aung Naing Raminder Pathak Suyu Liu Lei Feng Razelle Kurzrock 《Clinical breast cancer》2010,10(1):46-51
PurposePatients with metastatic breast cancer (MBC) refractory to standard therapy have a poor prognosis. We assessed prognostic factors and clinical outcomes for patients with MBC referred to a phase I clinic focused primarily on targeted agents.Patients and MethodsWe reviewed the medical records of sequential patients with MBC who presented to our phase I clinic between September 2004 and May 2008 to assess baseline patient characteristics, overall survival (OS), and clinical benefit.ResultsA total of 92 patients were identified, with a median age of 53 years (range, 28–83 years). The median number of previous therapies was 5 (range, 1–16 therapies). Of 92 patients, 78 were eligible for and offered ≥ 1 phase I clinical trial. With a median follow-up of 7.4 months, the median OS was 6.7 months (95% CI, 5.2–9.7). In multivariate analysis, independent factors predicting shorter survival were ≥ 10 previous treatments (vs. < 10 previous treatments; hazard ratio [HR], 3.27; 95% CI, 1.37–7.81; P = .008), Eastern Cooperative Oncology Group (ECOG) performance status (PS) 2/3 (vs. 0/1; HR, 2.92; 95% CI, 1.28–6.66; P = .01), and albumin level < 3.5 g/dL (vs. > 3.5 g/dL; HR, 2.88; 95% CI, 1.41–5.89; P = .004).ConclusionPatients with locally advanced or metastatic breast cancer referred for our phase I studies had a median survival of 6.7 months. Heavily pretreated disease, poor ECOG PS, and/or low albumin levels were associated with significantly shorter survival in a multivariate analysis. 相似文献
999.
Cytokines are key mediators of the development and homeostasis of haematopoietic cells, critical for host defense, but also for the development of autoimmune and inflammatory diseases such as psoriasis or rheumatoid arthritis (RA). Blocking cytokines activity by interfering with the ligand–receptor association has been successfully employed to treat several immune disorders. A subgroup of cytokines signals through receptors requiring the association with a family of cytoplasmic protein tyrosine kinases known as Janus kinases (Jaks). Jaks have recently gained significant attention as therapeutic targets in inflammation and autoimmunity, and several Jak inhibitory small molecules have been developed. The first two Jak inhibitors, tofacitinib and ruxolitinib, have been approved for the treatment of RA and primary myelofibrosis, respectively. Efficacy and safety data suggest that some of these oral Jak inhibitors as well as their topical formulations may soon enter the daily clinical practice for treating patients with psoriasis, lupus erythematosus or other inflammatory skin diseases. While biologics typically target one single cytokine, these new immunomodulators can inhibit signals from multiple cytokines intra‐cellularly and therefore could be useful when other therapies are ineffective. Thus, Jak inhibitors may replace some traditional immunosuppressive agents and help patients not responding to previous therapies. 相似文献
1000.
Genetic abnormalities in adolescents and young adults with neuroblastoma: A report from the Italian Neuroblastoma Group 下载免费PDF全文
Katia Mazzocco PhD Raffaella Defferrari PhD Angela Rita Sementa MD Alberto Garaventa MD Luca Longo PhD Marilena De Mariano PhD Maria Rosaria Esposito PhD Francesca Negri PhD Davide Ircolò Elisabetta Viscardi MD Roberto Luksch MD Paolo D'Angelo MD Arcangelo Prete MD Aurora Castellano MD Paolo Massirio MD Giovanni Erminio PhD Anna Rita Gigliotti MD Gian Paolo Tonini PhD Massimo Conte MD 《Pediatric blood & cancer》2015,62(10):1725-1732