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排序方式: 共有1307条查询结果,搜索用时 9 毫秒
31.
T. L. Oberle 《JOM Journal of the Minerals, Metals and Materials Society》1951,3(6):438-439
Wear of metals costs billions of dollars annually; an amount exceeded not even by the loss through corrosion of metals. The importance of metal wear is emphasized in this special JOURNAL OF METALS feature. It deals not only with factors influencing wear of metals, but also is a study of methods to reduce or eliminate this costly waste. 相似文献
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Jirina Tyleckova Rita Hrabakova Katerina Mairychova Petr Halada Lenka Radova Petr Dzubak Marian Hajduch Suresh J. Gadher Hana Kovarova 《International journal of molecular sciences》2012,13(12):15536-15564
A comprehensive proteome map of T-lymphoblastic leukemia cells and its alterations after daunorubicin, doxorubicin and mitoxantrone treatments was monitored and evaluated either by paired comparison with relevant untreated control and using multivariate classification of treated and untreated samples. With the main focus on early time intervals when the influence of apoptosis is minimized, we found significantly different levels of proteins, which corresponded to 1%–2% of the total amount of protein spots detected. According to Gene Ontology classification of biological processes, the highest representation of identified proteins for all three drugs belong to metabolic processes of proteins and nucleic acids and cellular processes, mainly cytoskeleton organisation and ubiquitin-proteasome pathway. Importantly, we observed significant proportion of changes in proteins involved in the generation of precursor metabolites and energy typical for daunorubicin, transport proteins participating in response to doxorubicin and a group of proteins of immune system characterising response to mitoxantrone. Both a paired comparison and the multivariate evaluation of quantitative data revealed daunorubicin as a distinct member of the group of anthracycline/anthracenedione drugs. A combination of identified drug specific protein changes, which may help to explain anti-cancer activity, together with the benefit of blocking activation of adaptive cancer pathways, presents important approaches to improving treatment outcomes in cancer. 相似文献
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Lia-Tânia Dinis Maria Manuela OliveiraJosé Almeida Rita CostaJosé Gomes-Laranjo Francisco Peixoto 《Food chemistry》2012,132(1):1-8
The antioxidant properties of different ecotypes of chestnut nut (cv. Judia) were studied. Total phenolics and flavonoids were also determinated. Total phenolics amount ranged from 9.6 mg/g of GAE (hottest ecotype, Murça) to 19.4 mg/g of GAE (coldest ecotype, Valpaços). Gallic and ellagic acid were the predominant compounds and Valpaços had the highest values while, Murça had the lowest ones. The antioxidant capacity of ethanolic extracts were evaluated through several biochemical essays: ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid)) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity, FRAP (ferric reducing/antioxidant power) and inhibition of oxidative haemolysis in erythrocytes. In order to evaluate the antioxidant efficiency of each ecotype, the EC50 values were calculated. Once again Valpaços revealed the best antioxidant properties, presenting much lower EC50 values. Climatic conditions influence seems to be a limiting factor for production of phenolic compounds and consequently for the antioxidant properties of chestnut nuts. 相似文献
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Seung Hee Woo Lena Yadgarov Rita Rosentsveig Yuwon Park Daesun Song Reshef Tenne Sung You Hong 《Israel journal of chemistry》2015,55(5):599-603
Sodium ion batteries (SIBs) are considered as a promising alternative to threaten the reign of lithium ion batteries (LIBs) among various next-generation rechargeable energy storage systems, including magnesium ion, metal air, and metal sulfur batteries. Since both sodium and lithium are located in Group 1 of the periodic table, they share similar (electro)chemical properties with regard to ionization pattern, electronegativity, and electronic configuration; thus the vast number of compounds developed from LIBs can provide guidance to design electrode materials for SIBs. However, the larger ionic radius of the sodium cation and unique (de)sodiation processes may also lead to uncertainties in terms of thermodynamic or kinetic properties. Herein, we present the first construction of SIBs based on inorganic fullerene-like (IF) MoS2 nanoparticles. Closed-shell-type structures, represented by C60 fullerene, have largely been neglected for studies of alkali-metal hosting materials due to their inaccessibility for intercalating ions into the inner spaces. However, IF-MoS2, with faceted surfaces, can diffuse sodium ions through the defective channels, thereby allowing reversible sodium ion intercalation/deintercalation. Interestingly, Re-doped MoS2 showed good electrochemical performances with fast kinetics (ca. 74 mA h g−1 at 20 C). N-type doping caused by Re substitution of Mo in IF-MoS2 revealed enhanced electrical conductivity and an increased number of diffusion defect sites. Thus, chemical modification of fullerene-like structures through doping is proven to be a promising synthetic strategy to prepare improved electrodes. 相似文献
36.
Chris Oberle 《Natural Gas \u0026amp; Electricity》2015,31(8):19-23
Contrary to what many pundits say about utilities' inability to provide service levels rivaling those of other types of providers, utility companies actually perform relatively well on standard metrics used to measure loyalty and satisfaction among consumers. However, while these metrics tend to reflect and reward strong operational performance, an area that has been the primary focus of utility companies for many years, these metrics do not necessarily capture the full essence of the relationship or the extent to which customers feel connected to and engaged with their local utility company. 相似文献
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Disabled people want to have the same opportunities and experiences as everyone else, yet owing to a number of barriers they are often excluded from meaningful employment. There are few statistics available in the UK to provide an accurate understanding of the number of disabled people within construction, and there remains a lack of research on employment, disability and construction. The perceptions of, and barriers faced by, young disabled people in considering potential employment in the construction industry were investigated. A participatory research approach was adopted which places disabled people at the heart of the research process. A mix of interviews and mini focus groups was undertaken with a total of 49 participants drawn from the North West of England. The need for inclusive approaches within the construction industry came across strongly, with participants preferring to be treated equally rather than being treated favourably. Disabled young people are unlikely to consider employment within construction without better awareness raising by industry–both employers and professional institutions–of the range and scope of opportunities available, and a dispelling of the myths that construction is for able-bodied, fit, men. 相似文献
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Rita B. Figueira Carlos J. R. Silva Elsa V. Pereira 《Journal of Coatings Technology and Research》2016,13(2):355-373
The aim of this experimental research was to study the electrochemical behavior of organic–inorganic hybrid (OIH) coatings for corrosion protection of hot-dip galvanized steel (HDGS) in the first instants of immersion in simulated concrete pore solution (SCPS) (pH > 12.5). The electrochemical performance of the OIH coatings was assessed by electrochemical impedance spectroscopy, potentiodynamic polarization curves, macrocell current density, and polarization resistance. The OIH coatings were prepared via the sol–gel method and were deposited on HDGS surfaces by dip-coating using one or three dip steps. The electrochemical results obtained for HDGS samples coated with OIH matrices in SCPS showed higher corrosion resistance than bare HDGS; as the molecular weight (MW) of Jeffamine® increased the barrier protection of the coating decreased. The lowest protection efficiency was found for HDGS samples synthesized with oligopolymers with an MW of 2000. Coatings produced with an oligopolymer of 230 MW conferred the highest protection. The surface morphology of the OIH coatings deposited on HDGS surfaces was studied by atomic force microscopy. The results show that the roughness of the OIH films depends on the MW of Jeffamine® and on the number of dip-coating steps used. Thermogravimetry results show that the Jeffamine® MW affected the thermal properties of the prepared OIH samples. The prepared OIH materials are thermally stable within the range of 20–80°C. 相似文献
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