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排序方式: 共有512条查询结果,搜索用时 15 毫秒
101.
Michele Ortolani Alessandra Di Gaspare Ennio Giovine Florestano Evangelisti Vittorio Foglietti Andrea Doria Gian Piero Gallerano Emilio Giovenale Giovanni Messina Ivan Spassovsky Claudio Lanzieri Marco Peroni Antonio Cetronio 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(12):1362-1373
High electron mobility transistors can work as room-temperature direct detectors of radiation at frequency much higher than their cutoff frequency. Here, we present a tool based on a Free Electron Laser source to study the detection mechanism and the coupling of the high frequency signal into the transistor channel. We performed a mapping over a wide area of the coupling of 0.15 THz radiation to an AlGaN/GaN transistors with cut-off frequency of 30 GHz. Local, polarization-dependent irradiation allowed us to selectively couple the signal to the channel either directly or through individual transistor bias lines, in order to study the nonlinear properties of the transistor channel. Our results indicate that HEMT technology can be used to design a millimeter-wave focal plane array with integrated planar antennas and readout electronics. 相似文献
102.
This paper presents an Application-specific Run-Time managEment (ARTE) framework to tackle the problem of managing computational resources in an application specific multi-core system. The ARTE framework run-time goal is to minimize applications’ response times while meeting the applications’ computational demands and fitting within the available power budget. 相似文献
103.
McCrae Robert R.; Costa Paul T.; de Lima Margarida Pedroso; Sim?es António; Ostendorf Fritz; Angleitner Alois; Maru?i? Iris; Bratko Denis; Caprara Gian Vittorio; Barbaranelli Claudio; Chae Joon-Ho; Piedmont Ralph L. 《Canadian Metallurgical Quarterly》1999,35(2):466
Both cross-sectional and longitudinal studies in the United States have shown consistent changes between college age and middle adulthood. There appear to be declines in 3 of the 5 major factors of personality-Neuroticism, Extraversion, and Openness-and increases in Agreeableness and Conscientiousness. To examine cross-cultural generalizability of these findings, translations of the Revised NEO Personality Inventory were administered to samples in Germany, Italy, Portugal, Croatia, and South Korea (N?=?7,363). Similar patterns of age differences were seen in each country, for both men and women. Common trends were also seen for the more specific traits that define the major factors. Because these nations differ substantially in culture and recent history, results suggest the hypothesis that these are universal maturational changes in adult personality. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
104.
Piero Savarino Enzo Montoneri Miriam Biasizzo Pierluigi Quagliotto Guido Viscardi Vittorio Boffa 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2007,82(10):939-948
BACKGROUND: In the context of the modern concern regarding rapid consumption and low availability of fossil sources of energy and chemicals, urban and agro‐industrial sources of chemicals represent interesting environmentally friendly alternatives. A recent paper has shown that a humic acid‐like material extracted from urban and green wastes compost exhibits very good surfactant properties. A large number of technological applications could possibly use this material as a chemical auxiliary. This paper reports on the performance of the material as a chemical auxiliary in textile dyeing. RESULTS: The compost‐isolated humic acid‐like bio‐surfactant is shown to perform in nylon 6 microfiber dyeing by water soluble and insoluble dyes as well as and more conveniently than commercial sodium dodecylsulfate (SDS) and sodium dodecylbenzenesulfonate (SDBS). With both types of dye the bio‐surfactant allows the same quality of dyed product as the synthetic surfactants do, but at lower additive concentration. From process cost and environmental impact points of view, the bio‐surfactant has the advantages of operating at much lower additive concentrations and should be available at significantly lower cost than the synthetic surfactants. CONCLUSION: The results suggest that biomass wastes may be a low cost renewable source of chemicals with friendly environmental impact. Such a perspective implies economic and environmental benefits deriving from a new waste management technology that considers biomass waste as a source of chemicals, and from lower oil consumption in the manufacture of synthetic surfactants. Copyright © 2007 Society of Chemical Industry 相似文献
105.
Claudia Canali Michele Colajanni Delfina Malandrino Vittorio Scarano Raffaele Spinelli 《计算机科学技术学报》2012,27(2):281-297
Multimedia content,user mobility and heterogeneous client devices require novel systems that are able to support ubiquitous access to the Web resources.In this scenario,solutions that combine flexibility,efficiency and scalability in offering edge services for ubiquitous access are needed.We propose an original intermediary framework,namely Scalable Intermediary Software Infrastructure (SISI),which is able to dynamically compose edge services on the basis of user preferences and device characteristics.The SISI framework exploits a per-user profiling mechanism,where each user can initially set his/her personal preferences through a simple Web interface,and the system is then able to compose at run-time the necessary components.The basic framework can be enriched through new edge services that can be easily implemented through a programming model based on APIs and internal functions.Our experiments demonstrate that flexibility and edge service composition do not affect the system performance.We show that this framework is able to chain multiple edge services and to guarantee stable performance. 相似文献
106.
Mauro Palmieri Alessandro Frati Antonio Santoro Paola Frati Vittorio Fineschi Alessandro Pesce 《International journal of molecular sciences》2021,22(19)
Traumatic brain injury (TBI) is a condition burdened by an extremely high rate of morbidity and mortality and can result in an overall disability rate as high as 50% in affected individuals. Therefore, the importance of identifying clinical prognostic factors for diffuse axonal injury (DAI) in (TBI) is commonly recognized as critical. The aim of the present review paper is to evaluate the most recent contributions from the relevant literature in order to understand how each single prognostic factor determinates the severity of the clinical syndrome associated with DAI. The main clinical factors with an important impact on prognosis in case of DAI are glycemia, early GCS, the peripheral oxygen saturation, blood pressure, and time to recover consciousness. In addition, the severity of the lesion, classified on the ground of the cerebral anatomical structures involved after the trauma, has a strong correlation with survival after DAI. In conclusion, modern findings concerning the role of reactive oxygen species (ROS) and oxidative stress in DAI suggest that biomarkers such as GFAP, pNF-H, NF-L, microtubule associated protein tau, Aβ42, S-100β, NSE, AQP4, Drp-1, and NCX represent a possible critical target for future pharmaceutical treatments to prevent the damages caused by DAI. 相似文献
107.
EP Leeflang S Tavaré P Marjoram CO Neal J Srinidhi H MacFarlane ME MacDonald JF Gusella M de Young NS Wexler N Arnheim 《Canadian Metallurgical Quarterly》1999,8(2):173-183
Trinucleotide repeat disease alleles can undergo 'dynamic' mutations in which repeat number may change when a gene is transmitted from parent to offspring. By typing >3500 sperm, we determined the size distribution of Huntington's disease (HD) germline mutations produced by 26 individuals from the Venezuelan cohort with CAG/CTG repeat numbers ranging from 37 to 62. Both the mutation frequency and mean change in allele size increased with increasing somatic repeat number. The mutation frequencies averaged 82% and, for individuals with at least 50 repeats, 98%. The extraordinarily high mutation frequency levels are most consistent with a mutation process that occurs throughout germline mitotic divisions, rather than resulting from a single meiotic event. In several cases, the mean change in repeat number differed significantly among individuals with similar somatic allele sizes. This individual variation could not be attributed to age in a simple way or to ' cis ' sequences, suggesting the influence of genetic background or other factors. A familial effect is suggested in one family where both the father and son gave highly unusual spectra compared with other individuals matched for age and repeat number. A statistical model based on incomplete processing of Okazaki fragments during DNA replication was found to provide an excellent fit to the data but variation in parameter values among individuals suggests that the molecular mechanism might be more complex. 相似文献
108.
Maria Teresa Rocchetti Pasquale Russo Vittorio Capozzi Djamel Drider Giuseppe Spano Daniela Fiocco 《International journal of molecular sciences》2021,22(21)
Lactiplantibacillus plantarum (L. plantarum) is a well-studied and versatile species of lactobacilli. It is found in several niches, including human mucosal surfaces, and it is largely employed in the food industry and boasts a millenary tradition of safe use, sharing a long-lasting relationship with humans. L. plantarum is generally recognised as safe and exhibits a strong probiotic character, so that several strains are commercialised as health-promoting supplements and functional food products. For these reasons, L. plantarum represents a valuable model to gain insight into the nature and mechanisms of antimicrobials as key factors underlying the probiotic action of health-promoting microbes. Probiotic antimicrobials can inhibit the growth of pathogens in the gut ensuring the intestinal homeostasis and contributing to the host health. Furthermore, they may be attractive alternatives to conventional antibiotics, holding potential in several biomedical applications. The aim of this review is to investigate the most relevant papers published in the last ten years, bioprospecting the antimicrobial activity of characterised probiotic L. plantarum strains. Specifically, it focuses on the different chemical nature, the action spectra and the mechanisms underlying the bioactivity of their antibacterial and antiviral agents. Emerging trends in postbiotics, some in vivo applications of L. plantarum antimicrobials, including strengths and limitations of their therapeutic potential, are addressed and discussed. 相似文献
109.
Matteo Trimarchi Dorina Lauritano Gianpaolo Ronconi Alessandro Caraffa Carla E. Gallenga Ilias Frydas Spyros K. Kritas Vittorio Calvisi Pio Conti 《International journal of molecular sciences》2022,23(21)
Much evidence suggests autoimmunity in the etiopathogenesis of periodontal disease. In fact, in periodontitis, there is antibody production against collagen, DNA, and IgG, as well as increased IgA expression, T cell dysfunction, high expression of class II MHC molecules on the surface of gingival epithelial cells in inflamed tissues, activation of NK cells, and the generation of antibodies against the azurophil granules of polymorphonuclear leukocytes. In general, direct activation of autoreactive immune cells and production of TNF can activate neutrophils to release pro-inflammatory enzymes with tissue damage in the gingiva. Gingival inflammation and, in the most serious cases, periodontitis, are mainly due to the dysbiosis of the commensal oral microbiota that triggers the immune system. This inflammatory pathological state can affect the periodontal ligament, bone, and the entire gingival tissue. Oral tolerance can be abrogated by some cytokines produced by epithelial cells and activated immune cells, including mast cells (MCs). Periodontal cells and inflammatory–immune cells, including mast cells (MCs), produce cytokines and chemokines, mediating local inflammation of the gingival, along with destruction of the periodontal ligament and alveolar bone. Immune-cell activation and recruitment can be induced by inflammatory cytokines, such as IL-1, TNF, IL-33, and bacterial products, including lipopolysaccharide (LPS). IL-1 and IL-33 are pleiotropic cytokines from members of the IL-1 family, which mediate inflammation of MCs and contribute to many key features of periodontitis and other inflammatory disorders. IL-33 activates several immune cells, including lymphocytes, Th2 cells, and MCs in both innate and acquired immunological diseases. The classic therapies for periodontitis include non-surgical periodontal treatment, surgery, antibiotics, anti-inflammatory drugs, and surgery, which have been only partially effective. Recently, a natural cytokine, IL-37, a member of the IL-1 family and a suppressor of IL-1b, has received considerable attention for the treatment of inflammatory diseases. In this article, we report that IL-37 may be an important and effective therapeutic cytokine that may inhibit periodontal inflammation. The purpose of this paper is to study the relationship between MCs, IL-1, IL-33, and IL-37 inhibition in acute and chronic inflamed gingival tissue. 相似文献
110.
Aponte M Blaiotta G Croce FL Mazzaglia A Farina V Settanni L Moschetti G 《Food microbiology》2012,30(1):8-16
The present work presents a successful attempt to achieve an enhanced and more predictable fermentation process in Spanish-style green olive technology by selection and use of autochthonous starter cultures. During the first phase of this work, two Spanish-like fermentations of green table olives of cultivar (cv) "Nocellara del Belice", coming from irrigated and not irrigated fields, were monitored, in order to highlight the best agricultural conditions for drupe production and to isolate lactic acid bacteria strains with relevant technological properties. Among 88 identified isolates, one Lactobacillus pentosus strain showed remarkable biochemical features and high acidification rate in synthetic brine. In the second phase, the selected strain was used as starter culture in three different trials to establish the best conditions for its use. Microbial counting, as well as starter tracking by M13 RAPD-PCR, reflected the optimal adaptation of the strain to the environment. Spontaneous fermentation needed a 14-day long lag phase to reach the same population as the inoculated trials. Moreover, sensory traits of table olives obtained with adjunct culture showed better characteristics compared to those processed in the other trials, in particular concerning the presence of off-odours. 相似文献