JIM杂谈 协作式领导

<正>全球商业环境需要协作式领导,管理人员应该放下领导者的架子,并与工作团队融为一体,提供指导、沟通、团队工作的便利、协调和支持。这将会比传统"老板-下属"的定位取得更好的成果。     

Monte Carlo simulation of the CHISEL flash memory cell

This work shows how physically-based hot carrier simulation was used to understand the importance of CHannel Initiated Secondary ELectron (CHISEL) injection in scaled MOSFETs, and how it was used to develop a powerful CHISEL-based technique for low voltage flash programming. Furthermore, it is shown how CHISEL flash addresses many of the disadvantages of CHE programming techniques, making it an ideal candidate for low-voltage, low-power Gigabit flash memories     

Lactobacillus spp. with in vitro probiotic properties from human faeces and traditional fermented products

Lactobacillus strains from traditional African fermented milk products, as well as human intestinal isolates were identified and investigated in vitro for their technological and functional characteristics as potential new probiotic strains. To test survival under gastrointestinal conditions, first the protective effect of milk and the effects of medium composition, lysozyme, pepsin, and pH of the medium on bacterial viability were assessed in vitro using the Plackett-Burman statistical model and the commercially used L. johnsonii LA1 probiotic strain. The use of either an artificial gastric electrolyte solution or MRS did not play a significant role in the viability of the cultures, while lysozyme, acidic conditions (pH 2.5), pepsin and the presence of milk significantly influenced the survival of the strain. Therefore, these parameters were selected as important test variables in a model stomach passage survival trial. Five strains identified as L. plantarum and two identified as L. johnsonii showed good survival under simulated gastrointestinal conditions. These selected strains also showed antimicrobial activity, probably due to production of organic acids. All strains exhibited bile salt hydrolase activity, while only the L. plantarum strains showed beta-galactosidase activity.     

Directly Compressed Mini Matrix Tablets Containing Ibuprofen: Preparation and Evaluation of Sustained Release

ABSTRACT

Directly compressed mini tablets were produced containing either hydroxypropylmethylcellulose (HPMC) or ethylcellulose (EC) as release controlling agent. The dynamics of water uptake and erosion degree of polymer were investigated. By changing the polymer concentration, the ibuprofen release was modified. In identical quantities, EC produced a greater sustaining release effect than HPMC. Different grades of viscosity of HPMC did not modify ibuprofen release. For EC formulations, the contribution of diffusion was predominant in the ibuprofen release process. For HPMC preparations, the drug release approached zero-order during a period of 8 h. For comparative purposes, tablets with 10 mm diameter were produced.     

Study of the content of cadmium,chromium and lead in bivalve molluscs of the Pacific Ocean (Maule Region,Chile)

The concentration of Cd, Cr and Pb in the following species Ameghinomya antiqua, Aulacomya atra and Mytilus chilensis, bivalves from Iloca, Constitución and Pelluhue, coastal towns located in the Maule Region, Chile was determined. Representative tissue samples of each species were analysed by using atomic absorption spectroscopy with flame. Validation of methodology was carried out using a certified reference material (TORT-1). The ranges of concentrations found for Cd, Cr and Pb in the 3 species were, respectively, 0.21–4.32, 0.38–12.62 and 0.43–31.10 mg kg⁻¹ dry weight. In relation to the results obtained and the average of each individual metal in the different species of bivalves, Pb concentrations were found in higher levels rather than those of other metals reported by other authors in a similar work, this element constitutes a potential health hazard for the consumers of shellfish. The results were statistically evaluated for possible correlations in the content of metals in different species and in different sites of origin.     

Multiferroic Bi 0.7Dy/ 0.3 FeO3 films as high k dielectric material for advanced non-volatile memory devices

Gate dielectric materials having high dielectric constant, low interface state density and good thermal stability are needed for advanced CMOS applications. In this letter, the electrical properties of novel multiferroic Bi_0.7Dy_0.3FeO₃ (BDFO) thin films deposited using the pulsed laser deposition technique on p-type (100) silicon substrate are reported. Using high frequency capacitance-voltage (C-V) measurements, the dielectric constant, effective oxide charge density and interface state density were estimated. The results suggest the potential application of multiferroic BDFO films as gate dielectric material for novel memory devices that can be electrically written and magnetically read.     

Zebrafish Motile Cilia as a Model for Primary Ciliary Dyskinesia

Zebrafish is a vertebrate teleost widely used in many areas of research. As embryos, they develop quickly and provide unique opportunities for research studies owing to their transparency for at least 48 h post fertilization. Zebrafish have many ciliated organs that include primary cilia as well as motile cilia. Using zebrafish as an animal model helps to better understand human diseases such as Primary Ciliary Dyskinesia (PCD), an autosomal recessive disorder that affects cilia motility, currently associated with more than 50 genes. The aim of this study was to validate zebrafish motile cilia, both in mono and multiciliated cells, as organelles for PCD research. For this purpose, we obtained systematic high-resolution data in both the olfactory pit (OP) and the left–right organizer (LRO), a superficial organ and a deep organ embedded in the tail of the embryo, respectively. For the analysis of their axonemal ciliary structure, we used conventional transmission electron microscopy (TEM) and electron tomography (ET). We characterised the wild-type OP cilia and showed, for the first time in zebrafish, the presence of motile cilia (9 + 2) in the periphery of the pit and the presence of immotile cilia (still 9 + 2), with absent outer dynein arms, in the centre of the pit. In addition, we reported that a central pair of microtubules in the LRO motile cilia is common in zebrafish, contrary to mouse embryos, but it is not observed in all LRO cilia from the same embryo. We further showed that the outer dynein arms of the microtubular doublet of both the OP and LRO cilia are structurally similar in dimensions to the human respiratory cilia at the resolution of TEM and ET. We conclude that zebrafish is a good model organism for PCD research but investigators need to be aware of the specific physical differences to correctly interpret their results.     

Effect of pore diffusional resistance on biocatalytic activity of Burkholderia cepacia lipase immobilized on SBA-15 hosts

The present study was focused on elucidating the effects of nanopore diffusional resistance on the activity of Burkholderia cepacia (BC lipase) lipase immobilized in ordered mesoporous silica hosts. BC lipase was immobilized in ordered SBA-15 hosts possessing 55 and diameter pores by physical adsorption. A colorimetric assay of p-nitrophenyl acetate was employed to determine the lipase catalytic activity. The effect of diffusional resistance on catalytic activity of lipase immobilized in SBA-15 hosts was investigated by determining the effective substrate diffusivity as a function of pore size of the SBA-15 host and enzyme loading. Lipase immobilized in SBA-15- exhibited 20-30% of free lipase activity and the activity was further reduced with enzyme loading due to limited accessibility of substrate to the enzyme active sites. Lipase immobilized in SBA-15- hosts showed catalytic activity similar to free lipase activity suggesting that diffusional limitations were minimal. Large pore SBA-15 hosts provided an improved environment for BC lipase to retain its catalytic activity.     

Expanded Core/Shell Poly(vinyl acetate)/Poly(vinyl alcohol) Particles for Embolization

An improvement to a previously published suspension polymerization process for the production of spherical core/shell PVAc/PVA particles is described. To increase the settling time of the beads in the suspension, an expansion stage was introduced. The core/shell structure was obtained through the partial hydrolysis of the PVAc. The particle density was manipulated through addition of a solvent during the suspension polymerization stage and posterior expansion of the polymer beads obtained at the end of the process. This technique allows for effective reduction of the density of the final polymer beads. The expansion stage exerts also a beneficial effect on particle drying, avoiding particle aggregation during post‐polymerization processing of the polymer beads.

     

Bioactive compounds and quantification of total ellagic acid in strawberries (Fragaria x ananassa Duch.)

Strawberries are one of the most popular edible fruits in Brazil and their consumption has increased with the development of new varieties available at almost all seasons. Fruit of seven full-ripened strawberry cultivars (Dover, Camp Dover, Camarosa, Sweet Charlie, Toyonoka, Oso Grande and Piedade) were characterized in relation to the total phenolics, vitamin C, flavonoids, free and total ellagic acid contents and antioxidant capacity. Camp Dover had the lowest values for anthocyanins and total phenolics but the highest total flavonoid content. Dover presented the highest anthocyanin, total phenolics and ellagic acid contents and also elevated antioxidant capacity. The best conditions for the determination of the total ellagic acid content in strawberries were also optimized and the results showed that the extraction with 80% acetone, and hydrolysis using 2 N TFA at 120 °C for 60 min allowed a 99% recovery.