全文获取类型
收费全文 | 3322篇 |
免费 | 186篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 52篇 |
妇产科学 | 77篇 |
基础医学 | 390篇 |
口腔科学 | 104篇 |
临床医学 | 263篇 |
内科学 | 737篇 |
皮肤病学 | 107篇 |
神经病学 | 527篇 |
特种医学 | 107篇 |
外科学 | 551篇 |
综合类 | 8篇 |
预防医学 | 110篇 |
眼科学 | 29篇 |
药学 | 176篇 |
中国医学 | 4篇 |
肿瘤学 | 274篇 |
出版年
2024年 | 6篇 |
2023年 | 27篇 |
2022年 | 78篇 |
2021年 | 137篇 |
2020年 | 82篇 |
2019年 | 83篇 |
2018年 | 120篇 |
2017年 | 103篇 |
2016年 | 118篇 |
2015年 | 113篇 |
2014年 | 174篇 |
2013年 | 207篇 |
2012年 | 284篇 |
2011年 | 286篇 |
2010年 | 174篇 |
2009年 | 146篇 |
2008年 | 248篇 |
2007年 | 211篇 |
2006年 | 182篇 |
2005年 | 188篇 |
2004年 | 177篇 |
2003年 | 164篇 |
2002年 | 113篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1975年 | 1篇 |
1974年 | 7篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有3536条查询结果,搜索用时 15 毫秒
21.
Chiara Merlino Massimiliano Bergallo Giorgio Gribaudo Gabriella Gregori Giuseppe Paolo Segoloni Franca Giacchino Alessandro Negro Ponzi Rossana Cavallo 《Journal of clinical virology》2003,28(3):265-274
BACKGROUND: Several studies have disclosed a correlation between polyomavirus BK (BKV) and interstitial nephritis in renal transplant recipients and its quantification in urine and serum is therefore required to assess the role of BKV infection in nephropathy. OBJECTIVE: This paper describes a urine and serum BKV-DNA quantification protocol devised to evaluate the viral load. STUDY DESIGN: Screening of samples containing > or =10(3)/ml viral genome copies by a semi-quantitative polymerase chain reaction (PCR) assay is followed by precise quantification of the samples containing a high number of viral genomes in a quantitative-competitive (QC)-PCR assay. Generation of the competitor construct relied on the different sizes of wild-type and competitor amplicons. RESULTS AND CONCLUSIONS: Screening by semi-quantitative PCR selects samples with a high number of viral genomes for use in the more labor-intensive and -expensive QC-PCR assay and thus provides a handy means for quantitative DNA analysis of large numbers of samples. The results obtained in BKV-DNA quantification in urine and serum samples from 51 renal transplant recipients (22 on treatment with tacrolimus (FK506) and 29 on cyclosporine A (Cy A)) are interesting: BKV-DNA findings (43.1%) in urine samples are in agreement with the BKV urinary shedding reported in literature (5-45%). With regard to immunosuppressive treatment, the percentage of activation of the infection (revealed by BKV-DNA detection in urine samples) in the two groups of therapy is similar (40.9% vs 44.8%). The observation that the viral load in urine is dissociated with that of serum suggests that both parameters should be investigated in evaluation of the pathogenetic role of BKV reactivation in renal transplant recipients. Moreover, our BKV-DNA quantification protocol could be used to monitor viral load in urine and serum samples from renal transplant recipients so as to detect those at risk of nephropathy and monitor their response to immunosuppression reduction therapy if it occurs. 相似文献
22.
Massimiliano Galdiero Mariateresa Vitiello Emma Sanzari Marina DIsanto Annalisa Tortora Anna Longanella Stefania Galdiero 《Infection and immunity》2002,70(2):558-568
In this study we examined the ability of Salmonella enterica serovar Typhimurium porins to activate activating protein 1 (AP-1) and nuclear factor kappaB (NF-kappaB) through the mitogen-activated protein kinase (MAPK) cascade, and we identified the AP-1-induced protein subunits. Our results demonstrate that these enzymes may participate in cell signaling pathways leading to AP-1 and NF-kappaB activation following porin stimulation of cells. Raf-1 was phosphorylated in response to the treatment of U937 cells with porins; moreover, the porin-mediated increase in Raf-1 phosphorylation is accompanied by the phosphorylation of MAPK kinase 1/2 (MEK1/2), p38, extracellular-signal-regulated kinase 1/2, and c-Jun N-terminal kinase. We used three different inhibitors of phosphorylation pathways: 2'-amino-3'-methoxyflavone (PD-098059), a selective inhibitor of MEK1 activator and the MAPK cascade; 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580), a specific inhibitor of the p38 pathway; and 7beta-acetoxy-1alpha,6beta,9alpha-trihydroxy-8,13-epoxy-labd-14-en-11-one (forskolin), an inhibitor at the level of Raf-1 kinase. PD-098059 pretreatment of cells decreases AP-1 and NF-kappaB activation by lipopolysaccharide (LPS) but not by porins, and SB203580 pretreatment of cells decreases mainly AP-1 and NF-kappaB activation by porins; in contrast, forskolin pretreatment of cells does not affect AP-1 and NF-kappaB activation following either porin or LPS stimulation. Our data suggest that the p38 signaling pathway mainly regulates AP-1 and NF-kappaB activation in cells treated with S. enterica serovar Typhimurium porins. Antibody electrophoretic mobility shift assays showed that JunD and c-Fos binding is found in cells treated with porins, in cells treated with LPS, and in unstimulated cells. However, by 30 to 60 min of stimulation, a different complex including c-Jun appears in cells treated with porins or LPS, while the Fra-2 subunit is present only after porin stimulation. These data suggest different molecular mechanisms of activation induced by porins or by LPS. 相似文献
23.
Elena Tragni Luisella Vigna Massimiliano Ruscica Chiara Macchi Manuela Casula Alfonso Santelia Alberico L. Catapano Paolo Magni 《Nutrients》2021,13(6)
Background: The prevention and treatment of obesity and its cardio-metabolic complications are relevant issues worldwide. Among lifestyle approaches, very low-calorie ketogenic diets (VLCKD) have been shown to lead to rapid initial weight loss, resulting in better long-term weight loss maintenance. As no information on VLCKD studies carried on in a real-world setting are available, we conducted this multi-centre study in a real-world setting, aiming at assessing the efficacy and the safety of a specific multiphasic VLCKD program in women with overweight or obesity. Methods: A multi-center, prospective, uncontrolled trial was conducted in 33 outpatient women (age range 27–60 y) with overweight or obesity (BMI: 30.9 ± 2.7 kg/m2; waist circumference: 96.0 ± 9.4 cm) who started a VLCKD dietary program (duration: 24 weeks), divided into four phases. The efficacy of VLCKD was assessed by evaluating anthropometric measures and cardiometabolic markers; liver and kidney function biomarkers were assessed as safety parameters. Results: The VLCKD program resulted in a significant decrease of body weight and BMI (−14.6%) and waist circumference (−12.4%). At the end of the protocol, 33.3% of the participants reached a normal weight and the subjects in the obesity range were reduced from 70% to 16.7%. HOMA-IR was markedly reduced from 3.17 ± 2.67 to 1.73 ± 1.23 already after phase 2 and was unchanged thereafter. Systolic blood pressure decreased after phase 1 (−3.5 mmHg) and remained unchanged until the end of the program. Total and LDL cholesterol and triglycerides were significantly reduced by VLCKD along with a significant HDL cholesterol increase. Liver, kidney and thyroid function markers did not change and remained within the reference range. Conclusions: The findings of a multi-center VLCKD program conducted in a real-world setting in a cohort of overweight/obese women indicate that it is safe and effective, as it results in a major improvement of cardiometabolic parameters, thus leading to benefits that span well beyond the mere body weight/adiposity reduction. 相似文献
24.
25.
Vascular endothelial growth factor and basic fibroblast growth factor in polycystic ovary syndrome during controlled ovarian hyperstimulation. 总被引:4,自引:0,他引:4
Paolo Giovanni Artini Massimiliano Monti Cristiana Matteucci Valeria Valentino Francesca Cristello Andrea Riccardo Genazzani 《Gynecological endocrinology》2006,22(8):465-470
BACKGROUND: Polycystic ovary syndrome (PCOS) is a common endocrine disorder that causes anovulation and consequent subfertility. It is well established that increased ovarian mass, supported by new blood vessel proliferation in stroma and theca, is a key feature of PCOS. Recent studies suggest a role for angiogenetic factors in this phenomenon. AIM: To evaluate of levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in serum and follicular fluid of PCOS patients during a controlled ovarian hyperstimulation. METHODS: In 52 patients undergoing in vitro fertilization treatments, 26 PCOS patients and 26 controls, serum VEGF and bFGF levels were assessed before starting administration of follicle-stimulating hormone (FSH) (day 0), on the day of administration of human chorionic gonadotropin (hCG) and on the day of oocyte retrieval. Follicular fluid levels of the two growth factors were detected on the day of oocyte retrieval. RESULTS: PCOS patients showed higher serum VEGF levels than controls before starting FSH administration, on the day of hCG administration and on the day of oocyte retrieval. Serum VEGF levels showed a rise after hCG administration only in the PCOS patients. In addition, serum bFGF levels were higher in PCOS patients than in controls on the day of hCG administration and the day of oocyte retrieval. Furthermore, on the day of hCG administration, serum bFGF levels were directly correlated to the amount of FSH previously administered (p < 0.0001). In follicular fluid, higher VEGF and bFGF levels were found in PCOS patients than in controls. Furthermore, follicular-fluid bFGF concentrations were inversely correlated with the percentage of mature oocytes collected (p < 0.05). CONCLUSIONS: The present study revealed elevated levels of VEGF and bFGF in serum and follicular fluid in PCOS patients compared with controls. bFGF seems to be an FSH-dependent growth factor and its levels in follicular fluid are inversely correlated with the percentage of mature oocytes collected. 相似文献
26.
Pantalone O Palladino F Lotito RM Missere M Savino G Minella G Meduri A Natale L Marano P 《Rays》2003,28(1):13-19
The introduction of spiral multislice or multidetector CT (MSCT) has led to significant results in coronary diagnostic imaging. In fact with MSCT, isotropic (cubic voxel) three-dimensional imaging of large volumes (e.g. the entire cardiac volume) was possible in a single breath-hold. Moreover, with dedicated reconstruction algorithms, temporal resolution and scannable volume could be optimized, limiting the artifacts associated with the spiral technique. The quantification of calcium deposits in the coronary walls and, in particular, the morphologic study of these vessels represent an important challenge to this technique. Multislice CT with retrospective gating is now a relevant diagnostic instrument in coronary heart disease; however only most recent CT devices with 16 rows of detectors enable a real solution of problems of spatial (isotropic, submillimetric imaging) and temporal (< 0.5 s rotation time) required for correct identification of stenosis and plaque characterization, which are the two main goals of noninvasive coronary imaging. 相似文献
27.
Coaxial Drainage versus Standard Chest Tube after Pulmonary Lobectomy: A Randomized Controlled Study
Massimiliano Bassi Emilia Mottola Sara Mantovani Davide Amore Andreina Pagini Daniele Diso Jacopo Vannucci Camilla Poggi Tiziano De Giacomo Erino Angelo Rendina Federico Venuta Marco Anile 《Current oncology (Toronto, Ont.)》2022,29(7):4455
Chest tubes are routinely inserted after thoracic surgery procedures in different sizes and numbers. The aim of this study is to assess the efficacy of Smart Drain Coaxial drainage compared with two standard chest tubes in patients undergoing thoracotomy for pulmonary lobectomy. Ninety-eight patients (57 males and 41 females, mean age 68.3 ± 7.4 years) with lung cancer undergoing open pulmonary lobectomy were randomized in two groups: 50 received one upper 28-Fr and one lower 32-Fr standard chest tube (ST group) and 48 received one 28-Fr Smart Drain Coaxial tube (SDC group). Hospitalization, quantity of fluid output, air leaks, radiograph findings, pain control and costs were assessed. SDC group showed shorter hospitalization (7.3 vs. 6.1 days, p = 0.02), lower pain in postoperative day-1 (p = 0.02) and a lower use of analgesic drugs (p = 0.04). Pleural effusion drainage was lower in SDC group in the first postoperative day (median 400.0 ± 200.0 mL vs. 450.0 ± 193.8 mL, p = 0.04) and as a mean of first three PODs (median 325.0 ± 137.5 mL vs. 362.5 ± 96.7 mL, p = 0.01). No difference in terms of fluid retention, residual pleural space, subcutaneous emphysema and complications after chest tubes removal was found. In conclusion, Smart Drain Coaxial chest tube seems a feasible option after thoracotomy for pulmonary lobectomy. The SDC group showed a shorter hospitalization and decreased analgesic drugs use and, thus, a reduction of costs. 相似文献
28.
Alessandro Dal Bosco Alice Cartoni Mancinelli Gaetano Vaudo Massimiliano Cavallo Cesare Castellini Simona Mattioli 《Nutrients》2022,14(15)
Chicken meat is becoming the most consumed in the world for both economic and nutritional reasons; regarding the latter, the lipid profile may play positive or negative roles in the prevention and treatment of diseases. In this study, we define the state of the art of lipid-based nutritional indexes and used the lipid content and fatty acid profile (both qualitative and quantitative) of breast meat of two poultry genotypes with different growth rates and meat traits. Further, we summarize and review the definitions, implications, and applications of nutritional indexes used in recent years and others of our own design to provide a useful tool to researchers working in the field of meat quality (not only in poultry) to select the most appropriate index for their own scientific purposes. All indexes show advantages and disadvantages; hence, a rational choice should be applied to consider the nutritional effect of meat on human health and for a possible assessment of the most suitable rearing systems (genotype, feeding, farming system or postmortem handling). 相似文献
29.
30.
Diego Gaddi Simone D. Gatti Massimiliano Piatti Andrea Poli Laura De Rosa Andrea Riganti Giovanni Zatti Marco Bigoni Marco Turati 《Indian Journal of Orthopaedics》2023,57(1):137
IntroductionBone consolidation defects represent a real orthopedic challenge because of the absence of validated treatment guidelines that can assist the surgeon in his choices. The aim of this study is to evaluate the appropriateness of the Non-Union Scoring System NUSS treatment protocol in the management of long bone non-unions by comparing it to the experience-based therapeutic approach carried out in our facility.Materials and MethodsWe conducted a comparative outcome study of a retrospective series of 89 patients surgically treated for long bone non-union in our facility vs. clinical results reported by Calori et al. obtained following the NUSS treatment protocol.ResultsRadiographic healing was reached in 13/13 non-unions (100%) in group NUSS 1, in 58/62 (93.5%) in group NUSS 2, and in 13/14 (92.9%) in group NUSS 3. The mean time to radiographic healing was 5.69 ± 2.09 months in group 1, 7.38 ± 3.81 months in group 2 and 9.23 ± 2.31 months in group 3. 91% of patients in group I, 69% in group II and 48% in group III received what would be considered by the NUSS treatment protocol an “overtreatment”, especially from a biological stand point. The comparative outcome analysis shows that our case series achieved significantly higher global healing rates (p value = 0.017) and shorter radiological healing times in groups NUSS 1 and 2 (p value < 0.001).ConclusionFrom the results obtained, we can assume that the NUSS treatment protocol might underestimate the necessary therapies, particularly from a biological point of view. 相似文献