108 research outputs found
Photo-Induced Electron Transfer in P3DDT, P3OT, M3EH-PPV Conjugated Polymers Blended with Maleic Anhydride in THF Solution Under UV Flash Photolysis Studied by Means of CW TR ESR
Free-radical signals of positive polarons in conjugated polymer chains and maleic anhydride (MA) anion radicals were registered in poly(3-octylthiophene) P3OT:MA and (poly[2,5-dimethoxy-1,4-phenylene-1,2-ethenylene-2-methoxy-5-(2-ethylhexyloxy)-(1,4-phenylene-1,2-ethenylene)]) M3EH-PPV:MA blends in tetrahydrofuran (THF) solutions under ultraviolet flash photolysis (308 nm) by continuous-wave time-resolved electron spin resonance. Their emissive chemically induced dynamic electron polarization (CIDEP) originated mainly from excited triplet states (triplet mechanism of CIDEP) and partly by from the radical pair mechanism due to the singlet-triplet mixing states. The observed M3EH-PPV polaron spectrum (g0 = 2.0029) supports the supposition that the previously registered CIDEP spectra in P3DDT:MA blends (g0 = 2.0021) can be attributed to the polaron signals instead of the possible solvate electron signal one. © 2011 Springer-Verlag
Photo-induced charge separation process in (PCBM-C120O)/(M3EH-PPV) blend solid film studied by means of X and K-bands ESR at 77 and 120 K
The new fullerene dimer adduct PCBM-C120O was studied as an electron acceptor by light-induced ESR (LESR) when blended with the electron donor-conjugated polymer M3EH-PPV in a thin solid film. ESR parameters for the PCBM-C120O anion radical and the M3EH-PPV polaron (triaxial gx,y,z factors) were determined by X- and K-band ESR techniques at temperatures of 77 and 120 K. It was found that isotropic g0 of PCBM-C120O anion radical ESR spectra obtained in this blend under illumination is close to g-factors of electrochemically reduced (C120-O)-{radical dot} and does not coincide with the analogous parameter of (C120-O)2-{radical dot}{radical dot} (reported in literature). Spin relaxation parameters (T1 and T2) of the PCBM-C120O anion radical and M3EH-PPV positive polaron are similar to T1, T2 for light-induced ion radicals in the P3HT/PCBM blend. © 2010 Elsevier B.V. All rights reserved
Research findings from Africa in relation to WIPO development agenda priorities
Research findings indicate that there are several factors that inhibit access to knowledge, including unaffordability, unavailability and in some cases the lack of a reading culture. The African Copyright and Access to Knowledge (ACA2K) research studies further the understanding of the relationship between national copyright environments and access to knowledge (learning materials in particular). The World Intellectual Property Organization (WIPO) Development Agenda recognises that renewed efforts are required ‘to further facilitate access to knowledge and technology for developing countries and least developed countries (LDCs) to foster creativity and innovation.
The C-H bond activation in 1-ethyl-3-methylimidazolium acetate-copper(ii) acetate-water-air (dioxygen) systems
Ionic liquid (1-ethyl-3-methylimidazolium acetate, [C2C 1im][AcO])-copper(ii) diacetate monohydrate-water-air (O2) systems have been investigated by 13C NMR, EPR, spectrophotometry, HPLC, and synthetic chemistry methods at different temperatures. The C-H bond activation of [C2C1im]+ with the formation of the unusual dication 1,1′-diethyl-3,3′-dimethyl-2,2′- biimidazolium ([(C2C1im)2]2+) at 50°C and 1-ethyl-3-methyl-1H-imidazol-2(3H)-one (C2C 1imO) at 50-85°C was revealed. Two new complexes with the above compounds, [(C2C1im)2][Cu(AcO)4] and Cu2(AcO)4(C2C1imO)2, were isolated from the systems and characterized by X-ray structural analysis. Catalytic cycles with the participation of copper(ii) acetate and dioxygen and the production of [(C2C1im)2]2+ and C2C1imO have been proposed. The catalysis presumably includes the formation of the CuII(O2)CuII active centre with μ-η2:η2-peroxide bridging in analogy with tyrosinase and catechol oxidase activity. © 2014 The Royal Society of Chemistry
Раствор альбумина в современной концепции инфузионной терапии – история продолжается?
Hypoalbuminemia and hypovolemia are independent risk factors for the development of multiple organ dysfunction, the main cause of death in critically ill patients. The use of a human albumin (HA) solution in complex of the fluid therapy affects both of these risk factors. However, more than 75 years of experience of HA use by the medical community and numerous clinical studies have proved its safety but did not lead to a consensus on the clinical effectiveness of its use. Thus, questions remain, and in which patients the use of HA is most appropriate. The authors of this review attempted to summarize the knowledge accumulated by the medical community on the use of HA in the practice of intensive care.Гипоальбуминемия и гиповолемия являются независимыми факторами риска развития полиорганной недостаточности, основной причиной смерти пациентов, находящихся в критическом состоянии. Применение раствора альбумина человеческого (АЧ) в комплексной инфузионной терапии влияет на оба этих фактора риска. Однако более чем 75-летний опыт применения АЧ медицинским сообществом и многочисленные клинические исследования показали его безопасность, но не привели к единому мнению о клинической эффективности применения. Таким образом, остается вопрос «у каких именно пациентов применение АЧ наиболее целесообразно?». Авторами данного обзора предпринята попытка обобщить накопленные знания о применении растворов альбумина в практике интенсивной терапии
Multifrequency X,W-band ESR study on photo-induced ion radical formation in solid films of mono- and di-fullerenes embedded in conjugated polymers
Anion-cation radical formation in solid films of M3EH-PPV blended with C60-PCBM, C120-O-PCBM and C60-MDHE, C 120-O-MDHE under diode laser (532 nm) and Xe-lamp light excitation studied by means of X,W-band at temperatures 30-80 K is reported. Subsequent high frequency W-band ESR data demonstrate the reproducible, but variable effect of appreciable dispersion (D) contribution in the ESR spectral line for the di-fullerene anion radicals. It is suggested that the increase of the D part relative to the absorption (A) in the summarized ESR absorption line in blends with difullerenes is caused by the higher value of difullerene medium conductivity. The obtained data are quantitatively discussed by the D/A ∼ F(d/δ) functional dependence in approach of plane film geometry, where d is the film thickness and δ is the skin-depth. The influence of ν-dependent δ at D/A value has been checked using X-band LESR. © 2014 Elsevier Ltd. All rights reserved
Effectiveness of a rural longitudinal integrated clerkship in preparing medical students for internship
Biomass fuel use, burning technique and reasons for the denial of improved cooking stoves by Forest User Groups of Rema-Kalenga Wildlife Sanctuary, Bangladesh
This is an electronic version of an article published in International Journal of Sustainable Development & World Ecology, 1745-2627, 18(1) 2011, 88-97. International Journal of Sustainable Development & World Ecology is available online at: http://www.informaworld.com/smpp/content~db=all~content=a933218896~frm=titlelinkUse of biomass fuel in traditional cooking stoves (TCS) is a long-established practice that has incomplete combustion and generates substances with global warming potential (GWP). Improved cooking stoves (ICS) have been developed worldwide as an alternative household fuel burning device, as well as a climate change mitigation. A study was conducted among female Forest User Groups (FUGs) of Rema-Kalenga Wildlife Sanctuary, Bangladesh, to assess the status of ICS disseminated by the Forest Department (FD) under the Nishorgo (2009) Support Project, along with the community's biomass fuel consumption pattern. Wood consumption was highest (345kg month-1 household-1) followed by agricultural residues (60kg month-1 household-1), tree leaves (51kg month-1 household-1) and cow dung (25kg month-1 household-1). Neighbouring forests of the sanctuary was the core source for wood fuel, with little or no reduction in the extraction even after joining the FUG. Twenty-two species, both indigenous and introduced, were preferred as wood fuel. None of the respondents were found willing to use ICS although 43% owned one; either as a status symbol or to meet the conditions of the FD for membership in FUG. Seven negative features of the disseminated ICS were identified by households, which made them unwilling to use them further. Manufacturing faults may be responsible for some ICS demerits, while the FD failed to convince the community of the benefits. A proper examination of the disseminated ICS efficacy is crucial, with active involvement of community members. The Sustainable Energy Triangle Strategy (SETS) could be implemented for this purpose. Findings of the study are of immense importance in designing a strategy for the introduction of ICS into Bangladesh.ArticleINTERNATIONAL JOURNAL OF SUSTAINABLE DEVELOPMENT AND WORLD ECOLOGY. 18(1):88-97 (2011)journal articl
Historic recombination in a durum wheat breeding panel enables high-resolution mapping of Fusarium head blight resistance quantitative trait loci
The durum wheat line DT696 is a source of moderate Fusarium head blight (FHB) resistance. Previous analysis using a bi-parental population identified two FHB resistance quantitative trait loci (QTL) on chromosome 5A: 5A1 was co-located with a plant height QTL, and 5A2 with a major maturity QTL. A Genome-Wide Association Study (GWAS) of DT696 derivative lines from 72 crosses based on multi-environment FHB resistance, plant height, and maturity phenotypic data was conducted to improve the mapping resolution and further elucidate the genetic relationship of height and maturity with FHB resistance. The Global Tetraploid Wheat Collection (GTWC) was exploited to identify durum wheat lines with DT696 allele and additional recombination events. The 5A2 QTL was confirmed in the derivatives, suggesting the expression stability of the 5A2 QTL in various genetic backgrounds. The GWAS led to an improved mapping resolution rendering the 5A2 interval 10 Mbp shorter than the bi-parental QTL mapping interval. Haplotype analysis using SNPs within the 5A2 QTL applied to the GTWC identified novel haplotypes and recombination breakpoints, which could be exploited for further improvement of the mapping resolution. This study suggested that GWAS of derivative breeding lines is a credible strategy for improving mapping resolution.This article is published as Sari, E., Knox, R.E., Ruan, Y. et al. Historic recombination in a durum wheat breeding panel enables high-resolution mapping of Fusarium head blight resistance quantitative trait loci. Sci Rep 10, 7567 (2020). https://doi.org/10.1038/s41598-020-64399-1
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