65 resultados para Bion, of Borysthenes, active 325 B.C.-255 B.C.


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HR 8799 is a multi-planet system detected in direct imaging, with three companions known so far. Here, we present spatially resolved Very Large Telescope/NACO 3.88-4.10 µm spectroscopy of the middle planet, HR 8799 c, which has an estimated mass of ~10 M Jup, temperature of ~1100 K, and projected separation of 38 AU. The spectrum shows some differences in the continuum from existing theoretical models, particularly longwards of 4 µm, implying that detailed cloud structure or non-equilibrium conditions may play an important role in the physics of young exoplanetary atmospheres.

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Optimal fault ride-through (FRT) conditions for a doubly-fed induction generator (DFIG) during a transient grid fault are analyzed with special emphasis on improving the active power generation profile. The transition states due to crowbar activation during transient faults are investigated to exploit the maximum power during the fault and post-fault period. It has been identified that operating slip, severity of fault and crowbar resistance have a direct impact on the power capability of a DFIG, and crowbar resistance can be chosen to optimize the power capability. It has been further shown that an extended crowbar period can deliver enhanced inertial response following the transient fault. The converter protection and drive train dynamics have also been analyzed while choosing the optimum crowbar resistance and delivering enhanced inertial support for an extended crowbar period.

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Study of nanomechanical response of iron carbides is important because presence of iron carbides greatly influences the performance and longevity of steel components. This work contributes to the literature by exploring nanoindentation of nanocrystalline Fe3C and tetrahedral-Fe4C using molecular dynamics simulation. The chemical interactions of iron and carbon were described through an analytical bond order inter-atomic potential (ABOP) energy function. The indentations were performed at an indentation speed of 50 m/sec and a repeat trial was performed at 5 m/sec. Load-displacement (P-h) curve for both these carbides showed residual indentation depth and maximum indentation depth (hf/hmax) ratio to be higher than 0.7 i.e. a circumstance where Oliver and Pharr method was not appropriate to be applied to evaluate the material properties. Alternate evaluation revealed Fe3C to be much harder than Fe4C. Gibbs free energy of formation and radial distribution function, coupled with state of the average local temperature and von Mises stresses indicate the formation of a new phase of iron-carbide. Formation of this newer phase was found to be due to deviatoric strain rather than the high temperature induced in the substrate during nanoindentation

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Oxidation of NADH in the mitochondrial matrix of aerobic cells is catalysed by mitochondrial complex I. The regulation of this mitochondrial enzyme is not completely understood. An interesting characteristic of complex I from some organisms is the ability to adopt two distinct states: the so-called catalytically active (A) and the de-active, dormant state (D). The A-form in situ can undergo de-activation when the activity of the respiratory chain is limited (i.e. in the absence of oxygen). The mechanisms and driving force behind the A/D transition of the enzyme are currently unknown, but several subunits are most likely involved in the conformational rearrangements: the accessory subunit 39 kDa (NDUFA9) and the mitochondrially encoded subunits, ND3 and ND1. These three subunits are located in the region of the quinone binding site. The A/D transition could represent an intrinsic mechanism which provides a fast response of the mitochondrial respiratory chain to oxygen deprivation. The physiological role of the accumulation of the D-form in anoxia is most probably to protect mitochondria from ROS generation due to the rapid burst of respiration following reoxygenation. The de-activation rate varies in different tissues and can be modulated by the temperature, the presence of free fatty acids and divalent cations, the NAD/NADH ratio in the matrix, the presence of nitric oxide and oxygen availability. Cysteine-39 of the ND3 subunit, exposed in the D-form, is susceptible to covalent modification by nitrosothiols, ROS and RNS. The D-form in situ could react with natural effectors in mitochondria or with pharmacological agents. Therefore the modulation of the re-activation rate of complex I could be a way to ameliorate the ischaemia/reperfusion damage. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference. Guest Editors: Manuela Pereira and Miguel Teixeira.

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This essay investigates the changing dynamics of interaction and paradigm of communication in the design studio. It analyses the process of practical implementation of interactive tools in architectural education which placed the
diversity of students’ cultural experiences, contextual awareness and individual interests as crucial resource for design innovation and inquiry. Building on Brian Lawson’s thesis on creativity in design thinking, this research project undertook
comprehensive investigation of students’ satisfaction of their roles in the studio and the room for liberal thought they are given to elaborate on genuine approach to architectural matters. The cyclical development of interactive learning strategy is explored through two different settings: first, it analyses architectural students’ position as passive/active in the studio, considering their relationships with tutors’ ideals; second, it reports on empirical strategy of students-led workshops at British schools of architecture, during which students have taken the lead of their creative design agenda. The practical implementation of interactive learning tools proved influential in helping students to personalize their design direction and to build a sense of confidence and independence.

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Drawing on national and regional letter collections dating from the late seventeenth and early eighteenth centuries, this article explores women's experiences of the life of the mind through an analysis of their letter-writing. This study also highlights the shortcomings of the compartmentalised nature of scholarship on women's writing and intellectual lives and proposes the letter both as a beneficial historical source and methodological tool for research on women's mental worlds. By employing an inclusive definition of intellectual and creative life, and eschewing traditional benchmarks of achievement, this article contends that women took a full part in the cultures of knowledge of their time. 

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Aim: To analyse the role of sex-focused knowledge in the contraceptive behaviour of sexually active young people in state care.

Methods: The sample consisted of 19 care leavers (young people previously in state care) aged 18-22 years, 16 females and 3 males. In-depth interviewing was the method of data collection, and a qualitative strategy resembling modified analytical induction was used to analyse data.

Findings: Findings indicated that a lack of information was not the sole, or even the primary reason for engaging in unsafe sexual practices. Other factors such as ambivalence to becoming pregnant also featured in participants’ accounts. Several participants conveyed a relatively weak sense of agency about consistently using contraception. A small number of participants expressed a strong determination to avoid pregnancy, and these appeared to have a level of anxiety about becoming pregnant that motivated them to engage with knowledge about contraception and its use.

Conclusion: Lack of sex-focused information is just one aspect of a myriad of complex factors, including socioeconomic disadvantage and/or emotional deprivation, that influences contraceptive behaviour.

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Treatment of hepatocellular cancer with chemotherapeutic agents has limited successin clinical practice and their efficient IC50 concentration would require extremely highdoses of drug administration which could not be tolerated due to systemic side effects.In order to potentiate the efficacy of anticancer agents we explored the potentialof co-treatment with pro-apoptotic Cytochrome c which activates the apoptoticpathway downstream of p53 that is frequently mutated in cancer. To this end weused hybrid iron oxide-gold nanoparticles as a drug delivery system to facilitate theinternalisation of Cytochrome c into cultured HepG2 hepatocellular carcinoma cells.Our results showed that Cytochrome c can be easily conjugated to the gold shell ofthe nanoparticles which are readily taken up by the cells. We used Cytochrome cin concentration (0.2μgmL-1) below the threshold required to induce apoptosis onits own. When the conjugate was administered to cells treated by doxorubicin, itsignificantly reduced its IC50 concentration from 9μgmL-1 to 3.5μgmL-1 as detectedby cell viability assay, and the efficiency of doxorubicin on decreasing viability ofHepG2 cells was significantly enhanced in the lower concentration range between0.01μgmL-1 to 5μgmL-1. The results demonstrate the potential of the application oftherapeutic proteins in activating the apoptotic pathway to complement conventionalchemotherapy to increase its efficacy. The application of hybrid iron oxide-goldnanoparticles can also augment the specificity of drug targeting and could serve as amodel drug delivery system for pro-apoptotic protein targeting and delivery.

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Background
Prostate cancer is one of the most common male cancers worldwide. Active Surveillance (AS) has been developed to allow men with lower risk disease to postpone or avoid the adverse side effects associated with curative treatments until the disease progresses. Despite the medical benefits of AS, it is reported that living with untreated cancer can create a significant emotional burden for patients.

Methods/design
The aim of this study is to gain insight into the experiences of men eligible to undergo AS for favourable-risk PCa.

This study has a mixed-methods sequential explanatory design consisting of two phases: quantitative followed by qualitative. Phase 1 has a multiple point, prospective, longitudinal exploratory design. Ninety men diagnosed with favourable-risk prostate cancer will be assessed immediately post-diagnosis (baseline) and followed over a period of 12 months, in intervals of 3 month. Ninety age-matched men with no cancer diagnosis will also be recruited using peer nomination and followed up in the same 3 month intervals. Following completion of Phase 1, 10–15 AS participants who have reported both the best and worst psychological functioning will be invited to participate in semi-structured qualitative interviews. Phase 2 will facilitate further exploration of the quantitative results and obtain a richer understanding of participants’ personal interpretations of their illness and psychological wellbeing.

Discussion
To our knowledge, this is the first study to utilise early baseline measures; include a healthy comparison group; calculate sample size through power calculations; and use a mixed methods approach to gain a deeper more holistic insight into the experiences of men diagnosed with favourable-risk prostate cancer.