An improved method for preparing glutaraldehyde cross-linked chitosan–poly(vinyl alcohol) microparticles

The features of microparticles, as size, surface structure, and morphology, depend, mainly, on the methodology used for their preparation. Emulsion polymerization techniques are undoubtedly among the most widespread. However, the use of toxic, volatile organic solvents represents a major disadvantage, namely, because of environmental issues. In this study, we prepared glutaraldehyde cross-linked chitosan–poly(vinyl alcohol) microparticles by an improved water-in-oil emulsion technique using corn oil as organic phase. The application of this polymeric blend as microparticle is scarcely investigated. As resulting of the procedure here presented, spherical and smooth surface microparticles were obtained, with mean diameter of 16 μm. The cross-linking reaction between the aldehyde and the amino or the hydroxyl groups formed either an imine (Schiff’s base) or an acetal bond, respectively, as analyzed by infrared spectroscopy. The microparticles here described did not present cytotoxic potential. Accordingly, this study can find promising and successful application in biotechnology.     

Fatty Acid Amide Hydrolase (FAAH) Inhibition Modulates Amyloid-Beta-Induced Microglia Polarization

The ability of endocannabinoid (eCB) to change functional microglial phenotype can be explored as a possible target for therapeutic intervention. Since the inhibition of fatty acid amide hydrolase (FAAH), the main catabolic enzyme of anandamide (AEA), may provide beneficial effects in mice model of Alzheimer’s disease (AD)-like pathology, we aimed at determining whether the FAAH inhibitor URB597 might target microglia polarization and alter the cytoskeleton reorganization induced by the amyloid-β peptide (Aβ). The morphological evaluation showed that Aβ treatment increased the surface area of BV-2 cells, which acquired a flat and polygonal morphology. URB597 treatment partially rescued the control phenotype of BV-2 cells when co-incubated with Aβ. Moreover, URB597 reduced both the increase of Rho protein activation in Aβ-treated BV-2 cells and the Aβ-induced migration of BV-2 cells, while an increase of Cdc42 protein activation was observed in all samples. URB597 also increased the number of BV-2 cells involved in phagocytosis. URB597 treatment induced the polarization of microglial cells towards an anti-inflammatory phenotype, as demonstrated by the decreased expression of iNOS and pro-inflammatory cytokines along with the parallel increase of Arg-1 and anti-inflammatory cytokines. Taken together, these data suggest that FAAH inhibition promotes cytoskeleton reorganization, regulates phagocytosis and cell migration processes, thus driving microglial polarization towards an anti-inflammatory phenotype.     

Bainite morphologies in sintered steels: influence of materials and process conditions

ABSTRACT

With the introduction of diffusion-bonded (d.b.) powders, metallographers found localised microstructure changes in sintered steels, and frequent presence of bainite. With the sinter-hardening process, the bainite fraction became a tool for rating the method. In this study, depending on different parameters, differences between bainitic structures of homogenous or not-homogeneous sintered steels have been analysed. When using pre-alloys, upper bainite is present with the same morphology. When using d.b. powders, variations of local composition lead to upper bainite of different morphology, each corresponding to a composition range. Quite high Ni local content gives rise to lower bainite, always mixed with martensite. Higher Ni contents lead to incoercible austenite. Upper bainite presents different morphologies, depending on local Ni and Cu amounts. The increase of sintering temperature leads to fewer morphologies of upper bainite, due to greater amount of diffusion processes. The lower bainite has always a typical morphology, whatever process parameters.     

Organisation design strategies for mass customisation: an information-processing-view perspective

The need to transform the organisation for mass customisation has long been recognised in literature, but the discussion has largely relied on anecdotal evidence or case studies and has limitedly taken advantage of insights from organisation theory. In this paper, we draw on organisational information-processing theory to develop solid theoretical links between mass customisation capability and four organisation design strategies aimed at either increasing an organisation's information-processing capacity or decreasing its information-processing needs. We then test the hypothesized relationships using a sample of 238 manufacturing plants from three industries and eight countries, and find that mass customisation capability is positively related to self-containment of tasks, environmental management, and use of lateral relations. We conclude by discussing implications of our results for both research and practice.     

Optimization models for the dynamic facility location and allocation problem

The design of logistic distribution systems is one of the most critical and strategic issues in industrial facility management. The aim of this study is to develop and apply innovative mixed integer programming optimization models to design and manage dynamic (i.e. multi-period) multi-stage and multi-commodity location allocation problems (LAP). LAP belong to the NP-hard complexity class of decision problems, and the generic occurrence requires simultaneous determination of the number of logistic facilities (e.g. production plants, warehousing systems, distribution centres), their locations, and assignment of customer demand to them. The proposed models use a mixed integer linear programming solver to find solutions in complex industrial applications even when several entities are involved (production plants, distribution centres, customers, etc.). Lastly, the application of the proposed models to a significant case study is presented and discussed.     

Aspect ratio dependence of the elastic properties of ZnO nanobelts

The Young's modulus of ZnO nanobelts was measured with an atomic force microscope by means of the modulated nanoindentation method. The elastic modulus was found to depend strongly on the width-to-thickness ratio of the nanobelt, decreasing from about 100 to 10 GPa, as the width-to-thickness ratio increases from 1.2 to 10.3. This surprising behavior is explained by a growth-direction-dependent aspect ratio and the presence of stacking faults in nanobelts growing along particular directions.     

Prevalence of 25(OH) vitamin D insufficiency and deficiency in chronic kidney disease stage 5 patients on hemodialysis

Little is known about the magnitude of vitamin D deficiency in patients with stage 5 chronic kidney disease (CKD-5) on hemodialysis (HD). In the present study, we examined the prevalence of vitamin D deficiency in patients with CKD-5 undergoing HD, evaluating the relationship between calcidiol levels with other parameters of mineral metabolism, nutrition/inflammation, functional capacity (FC), and sunlight exposure. Serum 25(OH) vitamin D levels were evaluated in 84 stable patients on chronic HD not receiving vitamin D supplements, with a mean age 58.9+/-16.6 years, during the month of September (end of winter in the southern hemisphere). 25(OH) vitamin D serum levels, intact PTH (iPTH), as well as serum albumin, calcium, phosphorus, and alkaline phosphatase were analyzed in fasting samples. Similarly, protein catabolic rate (PCR) and body mass index (BMI) were determined as nutritional parameters. Functional capacity according to the Karnofsky index, and sunlight exposure were also analyzed. In this study, we considered adequate vitamin D levels those above 30 ng/mL (U.S.A. National Kidney Foundation DOQI Guidelines), vitamin D insufficiency when levels were between 15 and 30 ng/mL, and vitamin D deficiency when levels were below 15 ng/mL. The mean 25(OH) D levels were significantly higher in men than in women (28.6 vs. 18.9 ng/mL; p=0.001). Vitamin D insufficiency was found in 53.5% of the patients (n=45) and vitamin D deficiency in 22.6% (n=19). In the univariate analysis, there were no correlations between 25(OH) D levels with age, iPTH, calcium, or phosphorus. There were positive correlations between serum 25(OH) D levels and degrees of sunlight exposure (R=0.55; p<0.0001), serum creatinine (r=0.38; p<0.001), serum albumin (r=0.22; p=0.04), and a negative correlation with BMI (r=-0.26; p=0.01). In the multiple regression analysis, only sunlight exposure (B=0.361), BMI (B=-0.23), and gender (B=-0.27) were significantly associated with 25(OH) D levels. Patients with FC 1 to FC 2 (n: 70%, 83.3%) had significantly higher 25(OH) D serum levels compared with FC 3 to FC 4 patients (n: 14%, 16.6%): 25.9 vs. 17.1 ng/mL (p=0.03). These results indicate that vitamin D insufficiency/deficiency is highly prevalent (76.1%) at the end of winter, in stage 5 CKD patients on HD, and lower values seem to be related to decreased sunlight exposure, female gender, increased BMI, and worse functional class.     

From water sensitive to floodable: defining adaptive urban design for water resilient cities

In growing urban areas, populations are increasingly exposed to the effects of climate change. Rainwater has been identified as a primary risk, although it is also an opportunity to pursue resilient and equitable cities while regenerating the urban ecosystem. Both urban design and landscape ecology have attempted to define effective responses to urban flooding and their synergy supports novel transdisciplinary approaches. The translation of adaptive management theories to the design process suggests working with rainwater rather than defending against it, combining science and practice. This paper retraces the evolution of design for flooding approaches and outlines the basis of an adaptive urban design for rainwater management.     

Corn salad (Valerianella locusta (L.) Laterr.) growth in a water-saving floating system as affected by iron and sulfate availability

BACKGROUND: Unbalanced nutrient availability causes disequilibrated plant growth, which can result in a worsening of harvested product quality, such as high nitrate content in edible tissues. To cope with this problem, improved knowledge of the mechanisms involved in nutrient acquisition and regulation is necessary. For this purpose the responses of acquisition mechanisms of N, Fe and S were studied as a function of Fe and S availability using two corn salad cultivars grown hydroponically, considering also aspects related to N metabolism. RESULTS: The results showed that an increase in Fe or S availability enhanced nitrate uptake and assimilation, which in turn increased biomass production of leaves with lower nitrate content. In particular, high S availability exerted a positive effect (gene expression and functionality) both on the uptake and metabolism of N and on Fe acquisition mechanisms. CONCLUSION: The data presented here show close interactions between N, S and Fe, highlighting that relevant improvements in yield and quality from soilless culture might also be obtained through appropriate adjustments of nutrient availability. In this respect, concerning the role of S in the acquisition mechanisms of N and Fe and in N metabolism, its level of availability should be taken into high consideration for equilibrated plant growth. Copyright © 2010 Society of Chemical Industry     

Changes in psychrotrophic microbial populations during milk creaming to produce Grana Trentino cheese

The aim of this study was to study the psychrotrophic microbiota developing during milk creaming of Grana Trentino cheese-making. 138 isolates from raw whole milk, cream and skim milk samples were screened by Randomly amplified polymorphic DNA PCR biotyping and representative strains of each biotype were characterised by partial 16S rRNA gene sequencing and enzymatic activity. Pseudomonadaceae were commonly isolated in cream samples while Streptococcaceae and Enterobacteriaceae in milk samples. Moraxellaceae and Flavobacteriaceae were found in both cream and milk samples.More than 80% of psychrotrophic isolates could grow at 37 °C. All Flavobacteriaceae and half of Pseudomonadaceae biotypes displayed proteolytic activity on milk agar even at low temperatures such as 10 °C. All Streptococcaceae and some of Enterobacteriaceae displayed acidifying activity and almost all Acinetobacter spp. (Moraxellaceae) displayed lipolytic activity towards tributyrin.Even if psychrotrophic bacteria is not the dominant microbial group in raw milk, their total number increases during creaming and becomes one of the most present group together with Lactic Acid Bacteria. Their enzymatic activities may be key players in determining milk quality for cheese making.