Cytochemical characterization and structural approach to Prosopis juliflora (Sw) D.C. seed gum extraction

Mesquite seed is a good gum source. In this work seed structure was characterized in order to help seed gum extraction. Seed gum was located between cotyledon and seed coat. Milling process yielded, basically, two fractions: endosperm and seed coat plus gum. This fact was supported by the cytochemical observation of a dense layer near the seed coat and a loose layer near the endosperm. Cells containing seed gum had thick cell walls and a proteic core. Seed gum extraction implications are discussed. Copyright © 2005 Society of Chemical Industry     

On the design of high-complexity cosine-modulated transmultiplexers based on the frequency-response masking approach

Two efficient techniques exploiting the frequency-response masking (FRM) approach are proposed in order to make it feasible to design prototype filters for highly selective nearly perfect-reconstruction cosine-modulated transmultiplexers and filter banks (CMTs and CMFBs) having a very large number of channels. In these design schemes, the number of unknowns is drastically reduced when compared with the corresponding techniques for designing direct-form prototype filters. Furthermore, in the proposed techniques, the main figures of merits, that is, the intersymbol interference and the interchannel interference for CMTs and the overall and aliasing distortions for CMFBs are taken into account in a controlled manner. In order to speed up the convergence of these two optimization techniques, simplifications for computing the resulting nonlinear constraints and the corresponding gradient vectors are proposed. They differ from each other in the sense that the first and second ones utilize the frequency-domain and time-domain constraints for controlling the figures of merit, respectively. Combining these two techniques results in numerically efficient algorithms for designing optimized CMTs (or CMFBs) with a reduced computational complexity (number of arithmetic operations per output sample), particularly when both branches of the FRM structure are required. Design examples are included illustrating the efficiency of the design methods and the high performance of the resulting CMT structures.     

Design and validation of a novel multiplex real-time PCR assay for Vibrio pathogen detection

Three species--Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus--account for the majority of vibrio infections in humans. Rapid and accurate identification of Vibrio species has been problematic because phenotypic characteristics are variable within species. Additionally, biochemical identification and confirmation require 2 or more days to complete. Rapid and sensitive molecular techniques for the detection of vibrio pathogens would be useful for the surveillance and management of outbreaks. To facilitate the identification of human-pathogenic species, we designed and validated a highly sensitive, specific, and robust multiplex real-time PCR assay to identify V. cholerae, V. parahaemolyticus, and V. vulnificus using a four-dye configuration in a convenient lyophilized format. Multiple Vibrio strains were sequenced to verify candidate target TaqMan sites. Several individual assays within the multiplex contain multiple primers or probes to ensure detection of polymorphic variants. V. cholerae, V. parahaemolyticus, and V. vulnificus were detected either individually or in mixtures at ≤30 genomic copies. V. cholerae was specifically detected in the presence or absence of Vibrio mimicus. The Vibrio multiplex assay showed 100% specificity to all targets analyzed and no detection of nearest neighbor strains. Each assay exhibited 100% ± 10% efficiency. Multiplex real-time PCR can simplify pathogen detection and reduce costs per test since three species can be analyzed in a single reaction tube. Rapid and accurate detection of pathogenic vibrios in shellfish or seawater samples will improve the microbiological safety of seafood for consumers.     

Adoptive immunotherapy for leukemia: donor lymphocytes transduced with the herpes simplex thymidine kinase gene for remission induction. HGTRI 0103

This study will evaluate the safety and efficacy of allogenic donor lymphocyte infusions in patients who have relapsed hematologic malignancies after allogeneic bone marrow transplantation (BMT). Donor lymphocyte transfusions have resulted in the cure of some patients with relapsed leukemia or lymphoproliferative disorder after allogeneic BMT, but has been complicated by the development of graft versus host disease (GvHD). We hypothesize that a retroviral vector containing the Herpes simplex thymidine kinase (HStk) gene will allow for retention of the anti-leukemia response of transfused donor lymphocytes while allowing for the adverse effects of GVHD to be mitigated. Patients with relapsed hematologic malignancies after allogeneic BMT will be infused with ex vivo gene modified donor lymphocytes. The Herpes Simplex thymidine kinase (HStk) gene will be transduced into the cells ex vivo using LTKOSN. 1 vector supernate. Insertion of the HStk gene into lymphocytes confers a sensitivity to the anti-herpes drug ganciclovir (GCV). This selective destruction of donor lymphocytes in situ will be used to abrogate the effect of graft versus host disease, if it develops.     

Effect of propellant on the combustion synthesized Sr-doped LaMnO3 powders

Lanthanum strontium manganite (LSM) powders of composition La_0.7Sr_0.3MnO₃ are good candidates for cathode application in solid oxide fuel cells. This paper reports the synthesis of LSM powders from nitrate precursors by the combustion method, using two different propellants (urea and glycine) and varying the propellant/nitrate ratio. Thermogravimetric analysis (TGA) revealed two or three decomposition stages of the as-synthesized samples, with complete burn out of organics at about 850–900 °C. X-ray diffraction (XRD) patterns showed formation of only LSM phase for the sample synthesized with excess of urea, whereas SrCO₃ and MnCO₃ phases were also found for the samples prepared from glycine. The powder is better crystallized when a homogeneous gel is formed before burning. The crystallite size calculated using the Scherrer equation is in the range of 15–20 nm. Scanning electron microscopy (SEM) revealed the presence of agglomerates, formed by fine particles of different shapes.     

Effect of pH on Characteristics of Low‐Moisture Mozzarella Cheese during Refrigerated Storage

ABSTRACT: This study evaluated the effect of cheese pH on proteolysis, calcium distribution, and functional characteristics of Mozzarella cheese. On 4 occasions, cultured low‐moisture part‐skim Mozzarella cheeses were obtained from a commercial producer on the day after manufacture. Cheese blocks were randomly assigned to 2 groups. One group was shredded, subdivided, and exposed to either ammonia vapor to increase the pH or HCl vapor to decrease the pH. Samples were vacuum packaged, stored at 4 °C, and analyzed for pH 4.6 and 12% TCA soluble nitrogen, apparent viscosity, free oil, and water‐soluble calcium on days 5, 12, 22, and 40. The 2nd group was sectioned into 23‐mm thick slabs and similarly exposed to either ammonia vapor to increase the pH or HCl vapor to decrease the pH. The slabs were vacuum packaged, stored at 4 °C, and analyzed for pH 4.6 and 12% TCA soluble nitrogen, TPA hardness, springiness and cohesiveness, and meltability on days 17, 29, and 41. Data were analyzed by ANOVA according to a spilt‐plot design. Experimentally induced pH differences persisted and significantly affected TPA hardness, apparent viscosity, meltability, and water‐soluble calcium throughout 40 d of storage, but did not affect soluble nitrogen changes. Thus, cheese pH affected functional characteristics and calcium distribution but did not affect proteolysis rates. Higher cheese pH resulted in a harder cheese that required longer aging to develop desirable melting characteristics, whereas cheese with lower pH developed desirable melting characteristics more quickly but had a shorter functional shelf life.     

Preparation of sorbitol-based polyurethanes and their semiinterpenetrating polymer networks

Sorbitol is a useful agro-based substance that is inexpensive and commercially available. In the interest of adding value to bio-based raw materials, we have synthesized polyurethanes from sorbitol and toluene-2,4-diisocyanate (TDI) through both conventional heat and microwave processes. Relative to conventional heat, the microwave process achieved the same reaction at a faster rate, thereby saving time and energy. The nature of the resulting polyurethane products depended on the stoichiometry of the reaction. At increasing TDI levels, a viscous liquid, a soft gel, or a hard thermoset could be obtained. The polymers were fully characterized with ¹³C-NMR, Fourier transform infrared, size exclusion chromatography, and thermogravimetric analysis. The polyurethanes obtained near the gel point could be used to make semiinterpenetrating polymer networks (semi-IPNs) with a second polymer, thereby imparting some of the properties of the second polymer onto the sorbitol-based polyurethane. For illustration, the sorbitol-based polyurethane semi-IPNs were made in combination with poly(vinyl pyrrolidone) and poly(lactic acid). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47602.     

A block-symmetric linearization of odd degree matrix polynomials with optimal eigenvalue condition number and backward error

The standard way of solving numerically a polynomial eigenvalue problem (PEP) is to use a linearization and solve the corresponding generalized eigenvalue problem (GEP). In addition, if the PEP possesses one of the structures arising very often in applications, then the use of a linearization that preserves such structure combined with a structured algorithm for the GEP presents considerable numerical advantages. Block-symmetric linearizations have proven to be very useful for constructing structured linearizations of structured matrix polynomials. In this scenario, we analyze the eigenvalue condition numbers and backward errors of approximated eigenpairs of a block symmetric linearization that was introduced by Fiedler (Linear Algebra Appl 372:325–331, 2003) for scalar polynomials and generalized to matrix polynomials by Antoniou and Vologiannidis (Electron J Linear Algebra 11:78–87, 2004). This analysis reveals that such linearization has much better numerical properties than any other block-symmetric linearization analyzed so far in the literature, including those in the well known vector space \(\mathbb {DL}(P)\) of block-symmetric linearizations. The main drawback of the analyzed linearization is that it can be constructed only for matrix polynomials of odd degree, but we believe that it will be possible to extend its use to even degree polynomials via some strategies in the near future.     

Remaining Life Evaluation Based on Strain Deformation Monitoring

The operating conditions of a power plant affect its structural integrity due to many degradation mechanisms, among which is creep. Strain measurements constitute a relatively simple and reliable method of obtaining accurate data regarding the capability of engineering materials to withstand loads and of determining stress distribution in all manner of structural components. This work carried out a critical evaluation of the application of a high-temperature strain gage on a strain and stress analysis. The sensor was undergoing a group of long-term creep tests whose results were compared with the creep machine’s acquisition system. The same strain gage was part of a monitoring system and its out some used on the remaining life evaluation a power plant’s pipeline. The methodology consists of online strain monitoring of those components or regions more susceptible to creep failure, which were identified by finite element analysis. The long-term creep tests using high-temperature strain gages showed that the relative position between sensor and the sample necking region exercises great influence on the measured results. Linear relationship between minimum creep rate obtained by strain gages and rupture time values was observed. The power plant pipeline analysis showed that thermomechanical fatigue is the predominant degradation mechanism.