Volume and surface effects on two-photonic and three-photonic processes in dry co-doped upconversion nanocrystals

Despite considerable advances in synthesizing high-quality core/shell upconversion(UC)nanocrystals(NC;UCNC)and UCNC photophysics,the application of near-infrare...     

减少振动高速凸轮廓线修正的简易方法

凸轮从动件的多余振动将造成系统的力、噪音、磨损和工作成本增加,本文采用凸轮轮廓输入成形来减少振动,输入成形是一种实际的时间控制算法,它是为计算机控制器开发的,为了应用凸轮设计概念,必须建立某些修正算法.采用可变的工作速度和从动件动力学建造一试验装置来检验高速输入外形凸轮轮廓的效能.试验结果表明本文推荐的解决方法是有用的.     

Changes of bioactive components in berry seed oils during supercritical CO2 extraction

The objective of the work was to elucidate the chemical composition of fractions of oil extracts obtained during the supercritical extraction on a semi‐industrial scale from strawberry (Fragaria x ananassa Duch.), chokeberry [Aronia melanocarpa (Michx.)], and raspberry (Rubus idaeus L.) seeds from industrial press cake. The oil extracts differed in terms of their content of bioactive components: carotenoids, tocopherols, chlorophylls, and fatty acids. Raspberry seed oil was the richest source of tocopherols (620.1–2166.7 mg kg^?1) and α‐linolenic acid (above 37%). Chokeberry seed oil had the highest content of linoleic acid (above 70%), and α‐tocopherol (166.0–1104.8 mg kg^?1). Strawberry oil was characterized by the highest content of chlorophylls and α‐linolenic acid (above 30%). It was showed that the oil fraction collected at the beginning of extraction is characterized by a high acid value, which requires purification steps to be used for food purposes.

Practical applications

Strawberry, raspberry, and chokeberry by‐products left over from the production of concentrated juice are a valuable source of oils rich in n‐3 and n‐6 polyunsaturated fatty acids, tocopherols, and carotenoids. The research showed that the fractionation of extracts in the course of supercritical extraction leads to oils with varying amounts of different bioactive compounds, and thus to products with potentially wide applications. Seeds oils have high potential utility as a source of unconventional oil for cosmetic and pharmaceutical sectors and biodiesel. Their targeted utilization may be exploited for economic, environmental and health benefits.     

Copper(II) ion removal from aqueous solutions using biosorption technology: thermodynamic and SEM–EDX studies

The present study uses biosorption technology to remove copper(II) ions from aqueous solutions. Mature leaves of neem (Azadirachta indica) were developed into powder form of size 32–45 μm and used as the biosorbent, while copper(II) ion solutions were prepared to be used as adsorbates. Parameters varied include copper(II) ion concentration and adsorption temperature. The neem leaf powder (NLP) dosage which was kept constant at 1.0 g L^?1 and pH was between 5 and 6. Adsorption occurred at a high rate initially and reached equilibrium after 50 min. Adsorption seemed to be more favourable at higher temperatures. Optimal temperature was found to be 333 K, with a high adsorption capacity of 146.30 mg g^?1. Thermodynamic studies showed that the system is spontaneous and endothermic in nature, based on the parameters of Gibbs free energy (?G°), biosorption enthalpy (?H°) and biosorption entropy (?S°) obtained, which gave values of ?2.74, 26.70 and 0.07 kJ mol^?1 K^?1, respectively. The adsorption mechanism was found to be predominantly chemisorption. SEM and EDX results show that copper(II) ions were adsorbed on the micropores of NLP. Results indicate that NLP is a suitable biosorbent for removing copper(II) ions from solutions.     

Young drivers--reduced crash risk with passengers in the vehicle

Studies have shown that the effect of passengers on accident propensity among young drivers is ambiguous--in some cases positive and some negative. In Sweden, various kinds of information are compiled in registers, including a national accident database and exposure data collected in a national investigation of the driving habits of license holders. Access to such data offers a good opportunity to study crash risks related to driving with and without passengers. This was done for drivers in three different age groups (18-24, 25-64 and >65 years) accompanied by one, two or three or more passengers. Differences in crash risk were estimated using incidence density ratios (IDRs) and 95% confidence intervals. The results show that passengers had an overall protective effect, that is, the crash risk was higher for those who drove alone, regardless of their age or gender. This protective effect increased with every extra passenger (up to eight), indicating that the more passengers in the vehicle, the safer the driving. The influence of passengers was weakest (albeit still positive) among the youngest drivers (ages 18-24 years), especially the males in that group. The protective impact showed the same pattern on all days of the week, but was most marked from Friday to Sunday for most of the drivers, regardless of age.     

CD40/APC-specific antibodies with three T-cell epitopes loaded in the constant domains induce CD4+ T-cell responses

CD4+ T lymphocytes play a central role in the orchestration and maintenance of the adaptive immune response. Targeting of antigen to antigen presenting cells (APCs) increases peptide loading of major histocompatibility complex (MHC) class II molecules and CD4+ T-cell activation. APCs have been targeted by APC-specific recombinant antibodies (rAbs) with single T-cell epitopes integrated in the constant region of the heavy chain (C(H)). However, the strategy may be improved if several T-cell epitopes could be delivered simultaneously by one rAb. We here demonstrate that a single rAb can be loaded with multiple identical or different T-cell epitopes, integrated as loops between β-strands in C(H) domains. One epitope was inserted in C(H)1, while two were placed in C(H)2 of IgG. T-cell proliferation assays showed that all three peptides were excised from loops and presented on MHC class II to T-cells. Induction of T-cell activation by each epitope in the multi-peptide rAb was as good, or even better, than that elicited by corresponding single-peptide rAbs. Furthermore, following DNA vaccination of mice with plasmids that encode CD40-specific rAbs loaded with either one or three peptides, T-cell responses were induced. Thus, integration of multiple epitopes in C(H) region loops of APC-specific rAbs is feasible and may be utilized in design of multi-vaccines.     

Soliton dynamics in photonic-crystal fibers for coherent Raman microspectroscopy and microscopy

We describe various generation schemes that employ soliton dynamics in photonic-crystal fibers to generate a red-shifted femtosecond pulse with high efficiency. We then detail how to use this pulse along with the initial femtosecond laser pulse for coherent Raman experiments. We describe various measurement schemes that, though utilizing this pair of femtosecond pulses, mimick the preferred measurement scheme for coherent Raman microspectroscopy where one pulse is transform-limited and of picosecond duration; or for coherent Raman microscopy where both pulses are transform-limited and of picosecond duration. We finally discuss how to increase pulse energy and give some perspective on the realization of a coherent Raman endoscope based on soliton dynamics.     

The effect of viscous substances on the transit time of barley digesta in rats

The influence of a number of hydrocolloids on the transit time of digesta, stool weight and colour of stools was investigated in rats. All hydrocolloids tested gave the stools a lighter colour and increased their size and water content. The hydrocolloids could be divided into two groups according to their action on digesta passage: pectin, gum arabic, oxidised starch and barley β-glucan retarded it, while guar gum, carrageenan, tragacanth gum, carob bean gum, sodium alginate and sodium carboxymethyl cellulose accelerated it. After feeding carrageenan for 1 week it took several weeks before water content and transit time returned to normal. Gum arabic was found to cause caecal distension.