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71.
Martina Rejtharová Libor Rejthar Katarína Čačková 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2018,35(2):233-240
A sensitive and robust confirmatory method for determination of steroid esters in blood serum is essential for reliable monitoring of possible illegal use of steroid hormones as growth promoters in meat production. A previously used sample preparation methodology was improved. The procedure consists of protein precipitation and removal of phospholipids by dispersive SPE Supel? QuE Z-Sep (Sigma-Aldrich) followed by clean-up on alumina column and LC-MS/MS measurement. The modified method has been validated according to Commission Decision 2002/657/EC. Validation parameters for determination of six testosterone esters and five nortestosterone esters in bovine and porcine blood serum are presented in this article. Decision limits for all analytes were observed in the range 10–20 pg mL?1. The method described is considerably robust for bovine and porcine serum analyses and can be applied both for screening and confirmatory determination in routine residue monitoring. 相似文献
72.
A strategic analysis of the electricity market in Western Australia yields a market potential for renewable energy in Western Australia. However, from a purely financial viewpoint the installation of grid-connected pv-systems still is not economically viable. In this paper a balanced scorecard (BSC) is developed to capture and visualize other than financial benefits. Therefore, the BSC can be used as a marketing tool to communicate the benefits of a privately owned GCPV system to potential customers. 相似文献
73.
74.
Atomic force microscopy (AFM) can image materials at the nanometer scale and obtain quantitative information
on their surface energy, roughness and hardness (Morris et al. 1999). AFM has also been used to quantify
changes in the surface properties of polymer films and coatings exposed to UV radiation or natural weathering,
but it has not been used to assess the photodegradation of wood (Biggs et al. 2001). The advantage of
using AFM to assess the photodegradation of polymers lies in its ability to reveal early changes in the
material on a nanometer scale and elucidate mechanisms responsible for such degradation. This study examined
if AFM could provide similar information and insights for wood exposed to solar radiation. 相似文献
75.
Frantisek Rybnikar Martina Kaszonyiova Roman Cermak Veronika Habrova Martin Obadal 《应用聚合物科学杂志》2013,128(3):1665-1672
This study focuses on the structure, morphology, and properties of linear polyethylene (PE) profiles manufactured by continuous extrusion. High level of chain orientation was achieved using specific flow and processing conditions. An extrusion die with semihyperbolic convergency was used to generate high percentage of elongational flow and chain extension. Simultaneously, high extrusion pressure and relatively low melt temperature led to flow‐induced crystallization of PE extended chains. The structure of PE tapes consists of crystal aggregates with different level of orientation and crystallinity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
76.
Ulrike Cress Katrin Wodzicki Martina Bientzle Andreas Lingnau 《International Journal of Computer-Supported Collaborative Learning》2011,6(2):307-321
Computer-supported collaborative learning has an unexploited potential of becoming an effective learning method for pupils
with intellectual disabilities. This paper aims at showing how some specific requirements of this target group may be met
by structuring a learning situation with the help of floor control, which restricts the opportunities of a learning dyad to act simultaneously within the learning environment. It was expected
that floor control could improve communication between pupils with intellectual disabilities by explicitly structuring and restricting activities
in the learning environment and making it necessary for the pupils to communicate. To examine if floor control really supports the collaboration process in the hypothesized way, two different versions of a CSCL environment were implemented
and compared. The results revealed improved task-related communication and a higher quality of interaction outcomes. 相似文献
77.
Building on recent research investigating the role of life-course factors (including childhood conditions) and societal context in older Europeans health status, this study investigates the determinants of changes in elders’ health across two waves of the Survey of Health Ageing and Retirement in Europe (SHARE). Controlling for individuals’ current living conditions at baseline, our analysis provides evidence for long-term associations between childhood conditions (SES, health, cognition) and health dynamics in older age. Moreover, our findings suggest that income inequality tends to increase elders’ risk of experiencing negative health changes (decreases their chance to recover from poor health, respectively). Our study underlines the importance of accounting for both life-course and societal determinants of later life health dynamics. 相似文献
78.
Martina Rudnicki Marcos Roberto de Oliveira Tiago da Veiga Pereira Flávio Henrique Reginatto Felipe Dal-Pizzol José Cláudio Fonseca Moreira 《Food chemistry》2007,100(2):719-724
The leaves of Passiflora alata Dryander and Passiflora edulis Sims, traditionally used in American countries to treat both anxiety and nervousness by folk medicine, are rich in polyphenols, which have been reported as natural antioxidants. In this study, the antioxidant activities of P. edulis and P. alata hydroalcoholic leaf extracts were verified in in vitro and ex vivo assays. P. alata showed a higher total reactive antioxidant potential than did P. edulis. The antioxidant activities of both extracts were significantly correlated with polyphenol contents. In addition, both extracts attenuated ex vivo iron-induced cell death, quantified by lactate dehydrogenase leakage, and effectively protected against protein damage induced by iron and glucose. These findings demonstrate that the P. alata and P. edulis leaf extracts have potent in vitro and ex vivo antioxidant properties and might be considered as possible new sources of natural antioxidants. 相似文献
79.
Which kind of instruction helps children aged 9–14 years interact efficiently with a mobile phone? Due to analogies between navigation in menu structures and the natural environment, three instructions providing different forms of spatial knowledge were under study: A step-by-step instruction featuring landmark knowledge of the menu functions to be selected, a diagram of the menu structure providing survey knowledge and a free exploration of the menu, also giving the children the opportunity to develop survey knowledge. Results show a superiority of the two instructions that provide survey knowledge, except for the youngest children aged 9–10 years. This group showed to have lower spatial abilities and is therefore presumably not able to understand and integrate this type of knowledge. For those very young children, the landmark information given in traditional step-by-step instructions is more helpful. It is concluded, that simple diagrams of the menu structure can help children from 11 years on to significantly ease their interaction with small menu driven devices. 相似文献
80.
Cristina Mazzaccara Bruno Mirra Ferdinando Barretta Martina Caiazza Barbara Lombardo Olga Scudiero Nadia Tinto Giuseppe Limongelli Giulia Frisso 《International journal of molecular sciences》2021,22(11)
Mitochondrial Cardiomyopathy (MCM) is a common manifestation of multi-organ Mitochondrial Diseases (MDs), occasionally present in non-syndromic cases. Diagnosis of MCM is complex because of wide clinical and genetic heterogeneity and requires medical, laboratory, and neuroimaging investigations. Currently, the molecular screening for MCM is fundamental part of MDs management and allows achieving the definitive diagnosis. In this article, we review the current genetic knowledge associated with MDs, focusing on diagnosis of MCM and MDs showing cardiac involvement. We searched for publications on mitochondrial and nuclear genes involved in MCM, mainly focusing on genetic screening based on targeted gene panels for the molecular diagnosis of the MCM, by using Next Generation Sequencing. Here we report twelve case reports, four case-control studies, eleven retrospective studies, and two prospective studies, for a total of twenty-nine papers concerning the evaluation of cardiac manifestations in mitochondrial diseases. From the analysis of published causal mutations, we identified 130 genes to be associated with mitochondrial heart diseases. A large proportion of these genes (34.3%) encode for key proteins involved in the oxidative phosphorylation system (OXPHOS), either as directly OXPHOS subunits (22.8%), and as OXPHOS assembly factors (11.5%). Mutations in several mitochondrial tRNA genes have been also reported in multi-organ or isolated MCM (15.3%). This review highlights the main disease-genes, identified by extensive genetic analysis, which could be included as target genes in next generation panels for the molecular diagnosis of patients with clinical suspect of mitochondrial cardiomyopathies. 相似文献