Deposition and photo-induced electrical resistivity of dip-coated NiO thin films from a precipitation process

Thin films of the semiconductor NiO are deposited using a straightforward combination of simple and versatile techniques: the co-precipitation in aqueous media along with the dip- coating process. The obtained material is characterized by gravimetric/differential thermal analysis (TG–DTA) and X-ray diffraction technique. TG curve shows 30 % of total mass loss, whereas DTA indicates the formation of the NiO phase about 578 K (305 °C). X-ray diffraction (XRD) data confirms the FCC crystalline phase of NiO, whose crystallinity increases with thermal annealing temperature. UV–Vis optical absorption measurements are carried out for films deposited on quartz substrate in order to avoid the masking of bandgap evaluation by substrate spectra overlapping. The evaluated bandgap is about 3.0 eV. Current–voltage (I–V) curves measured for different temperatures as well as the temperature-dependent resistivity data show typical semiconductor behavior with the resistivity increasing with the decreasing of temperature. The Arrhenius plot reveals a level 233 meV above the conduction band top, which was attributed to Ni²⁺ vacancy level, responsible for the p-type electrical nature of NiO, even in undoped samples. Light irradiation on the films leads to a remarkable behavior, because above bandgap light induced a resistivity increase, despite the electron–hole generation. This performance was associated with excitation of the Ni²⁺ vacancy level, due to the proximity between energy levels.     

绝热气动力学方程组整体光滑解的存在性与非存在性

本文研究Lagrange坐标下绝热气动力学方程组的Cauchy问题,得到了其整体光滑解的存在性定理与非存在性定理。     

An expert protein loop refinement protocol by molecular dynamics simulations with restraints

Protein structure prediction (PSP) is a long standing problem in structural biology and bioinformatics. Within the PSP problem loop refinement is a major bottleneck. In this article we report the latest version of the CReF expert predictor system for the PSP problem with emphasis on loop refinement of the approximate 3-D structure 1ZDD_P of the Z34C mini protein predicted by CReF. We designed a loop refinement protocol based on seven molecular dynamics (MD) simulations runs at different temperatures. We found that, by letting the loop residues move freely during dynamics at 325 K and restraining the internal coordinates of the correctly predicted helical structures, while allowing them to move relative to each other, the refinement protocol was very effective in predicting an accurate loop conformation in the first 100 ps of a 1000 ps MD simulation. The quality of the predictions was confirmed by the RMSD between refined and experimental structures which varied from 0.6 to 1.3 Å. In addition, stereochemical analyses showed that 100% of all residues of the refined 1ZDD_P, including those in the loop, populates the most favorable core regions of the Ramachandran plot. Our study suggests that the proposed protocol may be suitable to refine more complex mini proteins with different classes and architectures.     

Survey of safe and hygienic practices among Slovenian sauerkraut growers

Food safety demands calls for new approaches to better understand the safe and hygienic practices of specific sectors in the food supply chain. In the present study, sauerkraut growers were investigated to explore their understanding of food safety and hygiene practices. A combination of quantitative (questionnaire prepared for the study) and qualitative (ten in-depth interviews) methods was used in the study so that topics could be discussed more completely and in greater depth. The results indicated that sauerkraut growers possess a rather good level of knowledge concerning food safety, although some gaps were discovered (e.g., record keeping and the feeling that recording data was an unnecessary burden, inadequate acquaintance with health status requirements, insufficient knowledge of the cabbage production process of food safety professionals, etc.). Some differences were found when comparing the results of the qualitative and quantitative studies. The qualitative analysis highlighted some contradictions (e.g., an attitude toward the production process: “We do not need the HACCP system”; a feeling concerning product safety: “Why the need for data recording?”) and differences between the sauerkraut growers and a professional understanding of good practice guidelines for sauerkraut production. All other determinations concerning food safety knowledge and practices are presented and discussed. The findings can be used as a guide for reorganizing current education programs aimed to improve safe and hygiene practices at the farm level.     

Pelvic suspension and fast post-mortem chilling: Effects on technological and sensory quality of pork - A combined NMR and sensory study

The effects of pre-rigor excision, which results in a fast post-mortem chilling; pelvic suspension, which results in a muscular stretching; control treatment of m. longissimus dorsi on water distribution measured by (1)H NMR relaxometry and on sensory properties were investigated in two sub-studies including a total of 16 pigs. Determination of sarcomere length revealed significant effects of the treatments on the degree of contraction, as pre-rigor excision and pelvic suspension resulted in shorter and longer sarcomere length, respectively. In addition, an effect of treatment on pH measured at 24h post-mortem was found, as pre-rigor excision was associated with a higher ultimate pH. NMR measurements revealed that water distribution in the meat was affected to a minor degree by the various treatments. However, an interaction between treatment and ageing period was observed, as the data demonstrated an effect of pre-rigor excision on water distribution in the cooked samples when meat was only aged for 2 days, but this effect was eliminated when meat was aged for 5 days. The effect of pre-rigor excision on water distribution in cooked meat after 2 days of ageing is suggested to reflect structural constraints in the meat that are eliminated during ageing. Sensory analyses demonstrated strong interactions between treatment and position on the muscle and between treatment and ageing period. However, in general pre-rigor-excised meat was sensed as significantly juicier compared with the other two treatments. Accordingly, the study demonstrates that under the present conditions the ultimate pH is more important for juiciness than the sarcomere length.     

Molecular Dynamics-Derived Pharmacophore Model Explaining the Nonselective Aspect of KV10.1 Pore Blockers

The K_V10.1 voltage-gated potassium channel is highly expressed in 70% of tumors, and thus represents a promising target for anticancer drug discovery. However, only a few ligands are known to inhibit K_V10.1, and almost all also inhibit the very similar cardiac hERG channel, which can lead to undesirable side-effects. In the absence of the structure of the K_V10.1–inhibitor complex, there remains the need for new strategies to identify selective K_V10.1 inhibitors and to understand the binding modes of the known K_V10.1 inhibitors. To investigate these binding modes in the central cavity of K_V10.1, a unique approach was used that allows derivation and analysis of ligand–protein interactions from molecular dynamics trajectories through pharmacophore modeling. The final molecular dynamics-derived structure-based pharmacophore model for the simulated K_V10.1–ligand complexes describes the necessary pharmacophore features for K_V10.1 inhibition and is highly similar to the previously reported ligand-based hERG pharmacophore model used to explain the nonselectivity of K_V10.1 pore blockers. Moreover, analysis of the molecular dynamics trajectories revealed disruption of the π–π network of aromatic residues F359, Y464, and F468 of K_V10.1, which has been reported to be important for binding of various ligands for both K_V10.1 and hERG channels. These data indicate that targeting the K_V10.1 channel pore is also likely to result in undesired hERG inhibition, and other potential binding sites should be explored to develop true K_V10.1-selective inhibitors as new anticancer agents.     

Yeasts isolated from three varieties of grapes cultivated in different locations of the Dolenjska vine-growing region, Slovenia

The number and diversity of yeasts on grape berry surfaces are influenced by several factors, such as grape variety, degree of grape maturity at harvest, climatological conditions, geographic location, physical damage of grapes, the intensity of pest management etc. Cvicek is a typical Slovene wine, which has obtained a special protection under the Slovene Wine Law for its geographical origin. This blended red wine is produced from different grape varieties (Vitis vinifera L.), mostly from red grapes of Zametovka and Modra frankinja and from white grapes of Kraljevina. The aim of this study was to evaluate the impact of geographical locations in the Dolenjska vine-growing region and to obtain precise information about the influence of different grape varieties on the composition of yeast community on grape berries. The restriction fragment length polymorphism of PCR-amplified fragments from the rDNA gene cluster (PCR RFLP of rDNA) has been used for the differentiation of yeast species. The standard identification procedure has been performed on representative strains that shared identical RFLP profiles. The number of yeasts and yeast species isolated varied according to different grape varieties, Zametovka, Modra frankinja and Kraljevina (V. vinifera L.) and according to different sampling location. On the surface of grape berries 13 different yeast species have been identified. Saccharomyces cerevisiae has not been found.     

Elucidation of the relationship between cooking temperature, water distribution and sensory attributes of pork - a combined NMR and sensory study

Low-field NMR T(2) relaxation was measured continuously during cooking of pork samples (m. longissimus dorsi) to a final temperature of 75 °C. Simultaneously the remaining muscle was cooked in an oven to a core temperature of either 62 or 75 °C and subsequently evaluated by a sensory panel. Highly significant effects of final cooking temperature on the sensory attributes juiciness (initial and final), hardness, tenderness, crumbliness and chewing time were found. Juiciness and tenderness decreased with increasing temperature, while hardness, crumbliness and chewing time increased with increasing temperature. Distributed T(2) relaxation data revealed marked effects of temperature (62 vs. 75 °C) on the water distribution within the meat. Partial least squares (PLS) regressions were used to examine a potential prediction of sensory attributes from the distributed T(2) relaxation data, and high correlations were obtained. Moreover, loadings from the PLS regressions were analysed to evaluate the alterations in the water distribution as a function of temperature that contribute to changes in juiciness. This analysis revealed that the reduction in juiciness at 75 °C can be ascribed to changes in the size of the pores confining the myofibrillar water together with an expulsion of water.     

Individual metering of energy in existing buildings: potential and critical aspects

Individual metering of energy in flats is a real opportunity to save energy and money for the occupiers of collective-ownership buildings with centralised heating systems. The individual management of energy, through such devices, make users more responsible and also stimulates them to implement energy retrofit interventions in their flats. The use of individual metering systems in existing apartments, however, could have some critical aspects. The purpose of this paper is to analyse the application of individual energy systems in existing collective-ownership residential buildings, highlighting the critical aspects and providing practical solutions to overcome them. A study has been made of an individual metering application in an existing residential block of flats located in Milan (Italy) with poor thermal insulation between the various dwellings themselves and for the outside walls of the building. Although a net reduction of 50.4 % in the global costs for winter heating, obtained exclusively through plant-modification works, represents an optimum goal for energy savings, the study highlight some critical aspects. The savings for different apartments differ greatly and depend upon the criteria chosen for burden sharing. This study shows that the phenomenon of “heat theft” can prove to be important and provides the possibility of reducing to zero the quota of expenses from consumption whilst still benefiting from comfortable temperatures. Once the problems have been identified, the paper then proposes solutions to overcome them through a revision of the criteria for the allocation of energy costs.