Gravitational drainage of compressible organic materials

A model was developed to simulate drainage of compressible particle suspensions, and study how cake compression and volumetric load influence the process. The input parameters were settling velocity, cake resistance and compressibility. These parameters were found using a new experimental method. Dextran‐MnO₂ particle suspensions were drained as these resemble organic waste slurries with respect to settling and compressibility. It was demonstrated that cake compressibility must be taken into account to obtain adequate simulations. This implies that pressurized filtration resistances cannot be used for drainage simulations. In the filtration step, a distinct increase of dry matter from top to bottom of the cake was observed. During the subsequent consolidation, the cake compressed and a uniform dry matter profile was found. The final dry matter content of the cake increased with feed concentration and volumetric load. The drainage time increased proportionally with feed concentration and, more importantly, proportionally with squared volumetric load. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

Nutritional Value of Seven Freshwater Fish Species From the Brazilian Pantanal

This study determined the proximate composition and fatty acid profile of the lipid fraction in muscle tissue (fillet) of seven fish species from the Miranda River, Brazil. Total lipid content had the largest coefficient of variation among species (73%), while protein content had the smallest (4.5%), allowing Pimelodus argenteus (mandi-prateado) to be categorized as lean fish; Pimelodus maculatus (mandi-amarelo), Hemisorubim platyrhynchos (jurupoca), and Pinirampus pirinampu (barbado) as species with medium fat content, and Paulicea luetkeni (jaú) and Surubim lima (jurupensém) as fatty fish. In all the species investigated, palmitic acid (23.76–25.99%) was the predominant saturated fatty acid. Oleic acid (16.09–32.90%) was the most abundant monounsaturated fatty acid. Total omega-6 polyunsaturated fatty acids (5.99–15.56%) were the predominant polyunsaturated fatty acids, except in Ageneiosus brevifilis (palmito), in which total omega-3 polyunsaturated fatty acids predominated (10.30%). All the species had favorable indices of nutritional quality for total lipids, with respect to human consumption.     

Determination of Deep Frying Soybean Oil Disposal Point by a Sensory Method

Measurements of degradation in frying oils are mainly based on physico-chemical properties. Total polar compounds (TPC) and free fatty acids (FFA) content in frying oils are used as a guide for discarding used oils. The purpose of this study was to evaluate the efficacy of a sensory method in detecting degradation in soybean oils used in potato chips deep frying. The sensory evaluation of oil samples was determined by a trained panel; after rigorous selection and training steps. Free fatty acid, TPC and Rancimat induction period (IP) were quantified in the same samples. The proposed sensory method was sensitive to small differences in rancidity. The selected and trained sensory panel discarded oil samples with 0.175% FFA as oleic acid, 18.92% TPC, and 0.20 h IP. According to the results achieved in this research sensorial trained panel response is sensitive and accurate in refusing deteriorated frying oils. Besides this, soybean oil can be used for deep frying procedures and safely discarded according to the panel response, although presenting up to 7% linolenic acid.     

Analysis of regeneration of sterically hindered alkanolamines aqueous solutions with and without activator

This work concerns the comparison of the regeneration capability of different single sterically hindered alkanolamines (SHA: AMP, AEPD, AMPD, AHPD) or Pz-activated aqueous solutions with that of single MEA aqueous solution. It was found that AEPD, AMPD and AHPD offer an easier and faster regeneration than conventional alkanolamines (MEA). Small additions of Pz to single AHPD aqueous solutions were found to have a beneficial influence on the desorption performance.     

Fabrication of CdSe‐Nanofibers with Potential for Biomedical Applications

The design and synthesis of nanostructured functional hybrid biomaterials are essential for the next generation of advanced diagnostics and the treatment of disease. A simple route to fabricate semiconductor nanofibers by self‐assembled, elastin‐like polymer (ELP)‐templated semiconductor nanoparticles is reported. Core–shell nanostructures of CdSe nanoparticles with a shell of ELPs are used as building blocks to fabricate functional one‐dimensional (1D) nanostructures. The CdSe particles are generated in situ within the ELP matrix at room temperature. The ELP controls the size and the size‐distribution of the CdSe nanoparticles in an aqueous medium and simultaneously directs the self‐assembly of core–shell building blocks into fibril architectures. It was found that the self‐assembly of core–shell building blocks into nanofibers is strongly dependent on the pH value of the medium. Results of cytotoxicity and antiproliferation of the CdSe‐ELP nanofibers demonstrate that the CdSe‐ELP does not exhibit any toxicity towards B14 cells. Moreover, these are found to be markedly capable of crossing the cell membrane of B14. In contrast, unmodified CdSe nanoparticles with ELPs cause a strong toxic response and reduction in the cell proliferation. This concept is valid for the fabrication of a variety of metallic and semiconductor 1D‐architectures. Therefore, it is believed that these could be used not only for biomedical purposes but for application in a wide range of advanced miniaturized devices.     

Kinetics of Ag(I) catalyzed oxidation of amino acids by peroxomonosulphate

Silver(I) catalyzed oxidation of amino acids such as glycine and α-alanine by peroxomonosulphate (PMS) in aqueous perchloric acid medium was found to be first order in [peroxomonosulphate] and fractional order in [amino acid] and [Ag(I)]. The rate equation was derived by assuming equilibrium formation of adduct between amino acids and Ag(I). This adduct was presumed to react with PMS in a slow step to yield (adduct)²⁺, which was self-oxidized in a fast step to give the products. The kinetic results revealed that silver catalyzed reaction occurred approximately 10⁴ times faster than the uncatalyzed reaction and this is attributed to the formation of (adduct)²⁺. The bimolecular rate constant (k) for the slow step and the activation parameters were calculated and the results are discussed.     

Modification of the fat composition of the Iberian pig using Bacillus licheniformis and Bacillus subtilis

The aim of this work was to study the influence of a diet with probiotic bacteria on the lipid composition of different tissues from Iberian pigs. Cholesterol and fatty acid profiles were measured in liver, subcutaneous fat, and Serratus ventralis muscle samples. Feeding Iberian pigs a mixture of probiotic microorganisms for 45 days prior to slaughter affected the tissue composition. The feeds of the control and probiotic groups were identical except for the added Bacillus licheniformis and Bacillus subtilis (1.28 × 10⁹ cfu/kg feed) in the feed of the probiotic group. The diet with probiotics significantly affected the fatty acid profile of liver, subcutaneous fat and Serratus ventralis muscle samples, but no significant differences were found for the cholesterol content. The livers of the probiotic group contained lower levels of n‐6 fatty acids and higher levels of n‐3 fatty acids. The subcutaneous fat contained lower levels of n‐6 fatty acids. Serratus ventralis muscles from the probiotic group contained a significantly higher percentage of oleic acid than those of the control group. Practical applications: This study deals with the effect of the addition of probiotic bacteria to the diet of pigs on both the cholesterol and fatty acid content. B. subtilis and B. licheniformis can be used in pig feed (Regulation EC no. 2148/2004), but there are no studies about their effects on fresh meat or other tissues, particularly regarding the fat composition. Thus, it is interesting to study how feeding these microorganisms affects the different tissues. Including these microorganisms in the basic diet could serve as a strategy to modify the fat composition and to obtain healthier products from pigs.     

New Blended Cement from Polishing and Glazing Ceramic Sludge

Waste generated in ceramic tiles manufacturing is not usually recycled inside the productive plant, but rather disposed to landfill. This paper deals with ceramic residues from polishing and glazing processes, as constituents for innovative blended cements. New binders made up of 75% CEM I 52.5 R and 25% residues were chemically, physically, and mechanically characterized with reference to EN 197-1 requirements and the results compared with ordinary Portland cement. Mechanical strength development and microstructure of the relevant mortar have been investigated up to 90 days of curing, and the behavior of polishing and glazing residues as cement constituents is reported.     

Design and In vitro Evaluation of Branched Peptide Conjugates: Turning Nonspecific Cytotoxic Drugs into Tumor‐Selective Agents

The use of peptide receptors as targets for tumor‐selective therapies was envisaged years ago with the findings that receptors for different endogenous regulatory peptides are overexpressed in several primary and metastatic human tumors, and can be used as tumor antigens. Branched peptides can retain or even increase, through multivalent binding, the biological activity of a peptide and are very resistant to proteolysis, thus having a markedly higher in vivo activity compared with the corresponding monomeric peptides. Oligo‐branched peptides, containing the human regulatory peptide neurotensin (NT) sequence, have been used as tumor‐specific targeting agents. These peptides are able to selectively and specifically deliver effector units, for cell imaging or killing, to tumor cells that overexpress NT receptors. Results obtained with branched NT conjugated to different functional units for tumor imaging and therapy indicate that branched peptides are promising novel multifunctional targeting molecules. This study is focused on the role of the releasing pattern of drug‐conjugated branched NT peptides. We present results obtained with oligo‐branched neurotensin peptides conjugated to 6‐mercaptopurin (6‐MP), combretastain A‐4 (CA4) and monastrol (MON). Drugs were conjugated to oligo‐branched neurotensin through different linkers, and the mode‐of‐release, together with cytotoxicity, was studied in different human cancer cell lines. The results show that branched peptides are very promising pharmacodelivery options. Among our drug‐armed branched peptides, NT4–CA4 was identified as a candidate for further development and evaluation in preclinical pharmacokinetic and pharmacodynamic studies. This peptide–drug exhibits significant activity against pancreas and prostate human cancer cells. Consequently, this derivative is of considerable interest due to the high mortality rates of pancreas neuroendocrine tumors and the high incidence of prostate cancer.     

Gene Therapy in HIV‐Infected Cells to Decrease Viral Impact by Using an Alternative Delivery Method

The ability of dendrimer 2G‐[Si{O(CH₂)₂N(Me)₂⁺(CH₂)₂NMe₃⁺(I^?)₂}]₈ (NN16) to transfect a wide range of cell types, as well as the possible biomedical application in direct or indirect inhibition of HIV replication, was investigated. Cells implicated in HIV infection such as primary peripheral blood mononuclear cells (PBMC) and immortalized suspension cells (lymphocytes), primary macrophages and dendritic cells, and immortalized adherent cells (astrocytes and trophoblasts) were analyzed. Dendrimer toxicity was evaluated by mitochondrial activity, cell membrane rupture, release of lactate dehydrogenase, erythrocyte hemolysis, and the effect on global gene expression profiles using whole‐genome human microarrays. Cellular uptake of genetic material was determined using flow cytometry and confocal microscopy. Transfection efficiency and gene knockdown was investigated using dendrimer‐delivered antisense oligonucleotides and small interfering RNA (siRNA). Very little cytotoxicity was detected in a variety of cells relevant to HIV infection and erythrocytes after NN16 dendrimer treatment. Imaging of cellular uptake showed high transfection efficiency of genetic material in all cells tested. Interestingly, NN16 further enhanced the reduction of HIV protein 24 antigen release by antisense oligonucleotides due to improved transfection efficiency. Finally, the dendrimer complexed with siRNA exhibited therapeutic potential by specifically inhibiting cyclooxygenase‐2 gene expression in HIV‐infected nervous system cells. NN16 dendrimers demonstrated the ability to transfect genetic material into a vast array of cells relevant to HIV pathology, combining high efficacy with low toxicity. These results suggest that NN16 dendrimers have the potential to be used as a versatile non‐viral vector for gene therapy against HIV infection.