全文获取类型
收费全文 | 2573篇 |
免费 | 136篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 55篇 |
妇产科学 | 110篇 |
基础医学 | 357篇 |
口腔科学 | 81篇 |
临床医学 | 172篇 |
内科学 | 639篇 |
皮肤病学 | 75篇 |
神经病学 | 263篇 |
特种医学 | 81篇 |
外科学 | 226篇 |
综合类 | 13篇 |
预防医学 | 93篇 |
眼科学 | 13篇 |
药学 | 250篇 |
中国医学 | 1篇 |
肿瘤学 | 250篇 |
出版年
2023年 | 20篇 |
2022年 | 41篇 |
2021年 | 80篇 |
2020年 | 37篇 |
2019年 | 54篇 |
2018年 | 54篇 |
2017年 | 49篇 |
2016年 | 80篇 |
2015年 | 55篇 |
2014年 | 94篇 |
2013年 | 99篇 |
2012年 | 175篇 |
2011年 | 204篇 |
2010年 | 108篇 |
2009年 | 116篇 |
2008年 | 161篇 |
2007年 | 184篇 |
2006年 | 173篇 |
2005年 | 142篇 |
2004年 | 133篇 |
2003年 | 131篇 |
2002年 | 114篇 |
2001年 | 28篇 |
2000年 | 26篇 |
1999年 | 33篇 |
1998年 | 22篇 |
1997年 | 28篇 |
1996年 | 16篇 |
1995年 | 24篇 |
1994年 | 20篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 16篇 |
1990年 | 23篇 |
1989年 | 16篇 |
1988年 | 13篇 |
1987年 | 10篇 |
1986年 | 15篇 |
1985年 | 15篇 |
1984年 | 12篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有2716条查询结果,搜索用时 0 毫秒
21.
Evaluation of the E Test for Antimicrobial Susceptibility Testing of Pseudomonas aeruginosa Isolates from Patients with Long-Term Bladder Catheterization 下载免费PDF全文
Giovanni Di Bonaventura Evandro Ricci Nicoletta Della Loggia Giovanni Catamo Raffaele Piccolomini 《Journal of clinical microbiology》1998,36(3):824-826
The E test was evaluated in comparison with reference agar methods (National Committee for Clinical Laboratory Standards) for the susceptibility testing of 248 Pseudomonas aeruginosa isolates from bladder-catheterized patients against nine antibiotics. The E-test MICs correlated well with those determined by the agar dilution and disk diffusion reference methods (88 and 92.5% within 1 log2 dilution step, respectively), confirming that the E test is a reliable method for the determination of MICs of antibiotics for catheterization-associated P. aeruginosa isolates. 相似文献
22.
Paola Laurienzo Mario Malinconico Nicoletta Perenze Anna Laura Segre 《Macromolecular chemistry and physics.》1994,195(9):3057-3065
A new series of polyimides was synthesized by addition polymerization of 4,4′-(bismaleimido)-diphenylmethane, 1,4-piperazine and an amino-terminated polydimethylsiloxane. The synthesis was carried out in m-cresol solution following a two-step procedure. Copolymers containing 15 and 20 wt.-% of the polydimethylsiloxane elastomer were prepared, together with the unmodified base copolymer. Infrared spectroscopy, 13C and 1H NMR, thermal and thermogravimetric analyses were used to characterize the copolymers. The DSC curves of all the samples showed an exotherm in the temperature range 230–280°C, attributable to curing and addition reactions involving the chain-end groups. Different glass transition temperatures (Tg) were observed, depending on the elastomer content. Thermogravimetric analysis indicated that no significant changes occur in the thermal stability of rubber-modified copolymers. 相似文献
23.
24.
Masi G Perugi G Toni C Millepiedi S Mucci M Bertini N Akiskal HS 《Journal of affective disorders》2004,78(3):175-183
BACKGROUND: Growing evidence documents the frequent co-morbidity between Obsessive Compulsive Disorder (OCD) and Bipolar Disorder (BP) in adults. The aim of the present study is to explore some clinical aspects of this interface in children and adolescents, as it appears in a setting of routine clinical practice. METHOD: The sample comprised 102 consecutively referred children and adolescents, both inpatients and outpatients, with BP, OCD or co-morbid BP-OCD during a 3-year period. The mean age was 14.2 (SD=3.2); 65 (63.7%) were males. Diagnoses and clinical features were collected by means of structured interview according to DSM-IV (DICA-R) and a rating scale for OCD (CY-BOCS). Clinical outcome was evaluated prospectively by means of clinical global impression (CGI) as part of routine clinical care, throughout the follow-up. RESULTS: Thirty-seven (36.3%) patients (21 males and 16 females) were diagnosed as BP, 35 (34.3%) patients (26 males and 9 females) were diagnosed as OCD and 30 (29.4%) patients (18 males and 12 females) were diagnosed as BP-OCD. BP II, was more frequent in the BP-OCD than in BP. When OCD was co-morbid with BP, age of onset was significantly earlier than in the 'pure' OCD patients. On the contrary, age of onset of BP was not affected by co-morbid OCD. According to CGI baseline scores, OCD patients were significantly less impaired than BP-OCD and BP patients, while the severity of the symptomatology was similar in the last two groups. Severity scores at the end of the follow-up were significantly higher in BP-OCD patients than in OCD patients. Patients with pure BP showed lower rates of panic disorder-agoraphobia than BP-OCD patients and higher rates of ADHD-conduct disorder. Pure OCD patients showed lower rates of ADHD and higher rates of Generalized Anxiety Disorder. The number of obsessions did not differentiate the two groups, whereas pure OCD patients showed significantly more compulsions. 'Other' obsessions-e.g., existential, philosophical, odd and/or superstitious-were significantly more frequent in BP-OCD than in pure OCD patients. Ordering compulsions were significantly more frequent in pure OCD patients. LIMITATIONS: Possible low reliability of children's and their parents' recall of past episodes of mental disorder. CONCLUSIONS: In a tertiary care center, co-morbidity between OCD and BP is a significant clinical problem affecting a large number of patients. The correct identification of OCD-bipolar co-morbidity has relevant clinical implications as far as other concomitant disorders, symptomatological features, course, complications, and treatment management and outcome are concerned. 相似文献
25.
Silvano Adami Maurizio Rossini Nicoletta Zamberlan Francesco Bertoldo Romolo Dorizzi Vincenzo Lo Cascio 《Maturitas》1993,17(3):191-196
The transdermal and oral administration of estrogens for one year were compared with respect to the effects on lipid metabolism. Eighty-one postmenopausal women (1.5-3 years after menopause) were randomly divided into three groups. The first two groups received sequential estrogen treatment with either transdermal estradiol (Estraderm TTS, Ciba Geigy; 50 μg/day; 24 women) or 0.625 mg/day conjugated estrogens (Premarin, Wyeth; 20 subjects), respectively. In both groups medroxyprogesterone (10 mg/day per os) was added for 12 days of each cycle. Thirty-five subjects served as control group without therapy. No significant changes in the lipid profile was observed in control subjects after 1 year of follow-up. Serum triglycerides decreased significantly (-10.9 ± 26% S.D.; P < 0.05) in transdermal treated women, whereas it slightly rose in oral estrogen group. Comparable significant decreases in total and low density lipoprotein (LDL) cholesterol (mean range -6.5/-18.0%) were observed in women on estrogen replacement therapy. High density lipoprotein (HDL) cholesterol significantly diminished in transdermal estradiol group, but it rose slightly in the oral estrogen group. Thus the fraction of HDL cholesterol over LDL cholesterol did not change in the transdermal group whereas it significantly rose in subjects treated with oral estrogens. It remains to be established to what extent these differences on lipid metabolism are relevant for the prevention of cardiovascular diseases. 相似文献
26.
Jonathan T. Sims Venkatesh Krishnan Ching-Yun Chang Sarah M. Engle Giacomo Casalini George H. Rodgers Nicoletta Bivi Brian J. Nickoloff Robert J. Konrad Stephanie de Bono Richard E. Higgs Robert J. Benschop Silvia Ottaviani Anabela Cardoso Ajay Nirula Mario Corbellino Justin Stebbing 《The Journal of allergy and clinical immunology》2021,147(1):107-111
27.
28.
Tinnitus and temporomandibular joint dysfunction (TMJD) are among the most common complaints encountered by physicians. Though the relationship between tinnitus and TMJD has attracted great interest during the past several years, theories attempting to explain this association are still few and inconsistent. Conceivably, TMJD could irritate auricolo-temporal nerve (ATN), triggering a somatosensory pathway-induced disinhibition of dorsal cochlear nucleus (DCN) activity in the auditory pathway. In genetically-predisposed TMJD patients, signals from cronically stimulated DCNs activating specific cortical neuronal networks, could yield plastic neural changes resulting in tinnitus. Based on current evidence of serotoninergic modulation of neural activity and plasticity in sensory pathways, reduced serotoninergic tone could promote plastic changes underlying tinnitus through diminished filtering of incoming signals. Therefore, the early establishment of specific treatments aimed at improving TMJD and/or boosting serotoninergic activity may be required to prevent the creation of 'tinnitus memory circuits'. 相似文献
29.
Mario DeMarchi Iolanda Borelli Eleonora Olivetti Patricia Richiardi Pamela Wright Nicoletta Ansaldi Cristiana Barbera Bruna Santini 《Tissue antigens》1979,14(4):309-316
A group of 45 children affected with Coeliac Disease (CD) was typed for HLA-A, B, C, D, and DR specificities. The most significant associations were found with two alleles of the D series, with both cellular and serological typing. It is suggested that the susceptibility to CD is determined by two different genes within the HLA region, the first in common with organ-specific autoimmune diseases and associated with DW3, the second possibly specific for CD and associated with Dw7. 相似文献
30.
Hypoxia promotes murine bone-marrow-derived stromal cell migration and tube formation 总被引:13,自引:0,他引:13
Annabi B Lee YT Turcotte S Naud E Desrosiers RR Champagne M Eliopoulos N Galipeau J Béliveau R 《Stem cells (Dayton, Ohio)》2003,21(3):337-347
Recent evidence indicates that bone-marrow-derived stromal cells (MSCs) have a histology coherent with endothelial cells that may enable them to contribute to tumor angiogenesis through yet undefined mechanisms. In this work, we investigated the angiogenic properties of murine MSCs involved in extracellular matrix degradation and in neovascularization that could take place in a hypoxic environment such as that encountered in tumor masses. MSCs were cultured in normoxia (95% air and 5% CO(2)) or in hypoxia (1% oxygen, 5% CO(2), and 94% nitrogen). We found that hypoxic culture conditions rapidly induced MSC migration and three-dimensional capillary-like structure formation on Matrigel. In vitro, MSC migration was induced by growth-factor- and cytokine-enriched conditioned media isolated from U-87 glioma cells as well as from MSCs cultured in hypoxic conditions, suggesting both paracrine and autocrine regulatory mechanisms. Although greater vascular endothelial growth factor levels were secreted by MSCs in hypoxic conditions, this growth factor alone could not explain their greater migration. Interestingly, matrix metalloproteinase (MMP)-2 mRNA expression and protein secretion were downregulated, while those of membrane-type (MT)1-MMP were strongly induced by hypoxia. Functional inhibition of MT1-MMP by a blocking antibody strongly suppressed MSC ability to migrate and generate capillary-like structures. Collectively, these data suggest that MSCs may have the capacity to participate in tumor angiogenesis through regulation of their angiogenic properties under an atmosphere of low oxygen that closely approximates the tumor microenvironment. 相似文献