Circulating blood volume determination using electronic spin resonance spectroscopy

There have been numerous methods proposed to measure the circulating blood volume (CBV). Nevertheless, none of them have been massively and routinely accepted in clinical diagnosis. This study describes a simple and rapid method, on a rabbit model, using the dilution of autologous red cells labeled with a nitroxide radical (Iodoacetamide-TEMPO), which can be detected by electronic spin resonance (ESR) spectroscopy. Blood samples were withdrawn and re-injected using the ears' marginal veins. The average CBV measured by the new method/body weight (CBV(IAT)/BW) was 59 +/- 7 mL/kg (n = 33). Simultaneously, blood volume determinations using the nitroxide radical and (51)Cr (CBV(Cr)) were performed. In the plot of the difference between the methods (CBV(IAT) - CBV(Cr)) against the average (CBV(IAT) + CBV(Cr))/2, the mean of the bias was -1.1 +/- 6.9 mL and the limits of agreement (mean difference +/-2 SD) were -14.9 and 12.7 mL. Lin's concordance correlation coefficient p(c) = 0.988. Thus, both methods are in close agreement. The development of a new method that allows a correct estimation of the CBV without using radioactivity, avoiding blood manipulation, and decreasing the possibility of blood contamination with similar accuracy and precision of that of the "gold standard method" is an innovative proposal.     

Influence of the calcination temperature on the structure and reducibility of nanoceria obtained from crystalline Ce(OH)CO3 precursor

A high yield green method was developed for the preparation of reactive nanotextured ceria (CeO₂). The preparation method is based on the oxidation of a crystalline Ce(OH)CO₃ precursor that decompose at relative low temperature (ca. 250 °C) yielding CeO₂ nanocrystals initially rich in Ce³⁺. After increasing calcination temperatures (in the range 350-650 °C), PXRD analysis show a slight crystal growth after calcination temperatures up to 550 °C, however cell contraction in such case denotes the definitive oxidation of remnant Ce³⁺ centers. XPS results confirm Ce³⁺ fraction diminution as calcination temperature increases. TPR profiles of ceria samples show two reduction events being the low temperature one (at ca. 500 °C) related to a surface process in which approximately only one cerium monolayer is involved. Catalytic activity tests for COPROX reaction were performed under differential reactor conditions to evaluate their activity in the temperature range 100-300 °C. The optimum activity recorded for the sample calcined at 450 °C accounts for the compromise between oxide’s activation and surface preservation.     

Obtaining hydroxyapatite from the exoskeleton and spines of the purple sea urchin Strongylocentrotus purpuratus

We present a simple, quick, and viable way to produce hydroxyapatite (HA) from a waste by-product of the sea food industry, this was achieved by submitting the exoskeleton of the purple sea urchin Strongylocentrotus purpuratus through a chemical reaction with H₃PO₄ at 3 different times (3, 18, and 36 hours) with constant stirring at 35-40°C. The characterization of the materials was made by several techniques (FTIR, XRD, SEM-EDS, and TEM).The FTIR results confirmed the presence of the HA characteristic functional groups OH, PO₄, and CO₃, the XRD characterization showed that the synthesis of calcium phosphates such as brushite and HA was achieved by confirming the presence of its characteristic peaks, also the EDS analysis confirmed the expected HA Ca/P atomic ratio of 1.67. This work shows that we can take advantage from raw materials derived from processing sea food by giving it an added value for the biomedical industry.     

Forcespinning technique for the production of poly(d,l-lactic acid) submicrometer fibers: Process–morphology–properties relationship

This work addresses a systematic study for the process development and optimization of poly(d ,l -lactic acid) (PDLLA) submicrometer fibers utilizing the centrifugal spinning technique known as Forcespinning. This study analyzes the effect of polymer concentration (8, 10, and 12 wt %) and angular speed on the fiber morphology, diameter distribution, and fiber yield. The increase in polymer concentration and angular speed favored the formation of continuous and homogeneous submicrometer fibers with an absence of bead formation and higher output. The optimal conditions were established considering the morphological characteristics that exhibit a greater surface area (homogeneous and submicrometer fibers); and they were achieved at a polymer concentration of 10 wt % at an angular speed ranging from 8000 to 10 000 rpm. Optimization of PDLLA submicrometer fiber fabrication lays the groundwork for scaling up the process and serves as a platform to further develop promising applications of PDLLA nonwoven mats, particularly in the biomedical area such as in scaffolds for tissue engineering. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47643.     

Tensile Properties of Extruded Zein Sheets and Extrusion Blown Films

Zein‐based plastic sheets and films were formed by extrusion through a slit‐die or blowing head. Zein was plasticized with oleic acid and formed into a wet moldable mass (resin) to feed the extruders. Both single‐ and twin‐screw extruded sheets showed higher elongation at break, lower tensile strength, and lower Young's Modulus than non‐extruded samples. Stress‐strain plots for extruded samples showed evidence of plastic behavior. Observed necking of samples under tensile stress was also taken as evidence of plastic behavior. Small differences in tensile strength and elongation at break between single‐ and twin‐screw extruded samples were attributed to the effect of small voids observed by SEM in single‐screw extruded samples. Blown film extrusion was affected by feed moisture content and barrel temperatures. Optimal moisture content was determined at 14–15% while temperature at the three extruder zones was maintained at 20–25, 20–25, and 35 °C, respectively. Temperature at the blowing head was 45 °C. Film samples blown after either single‐ or twin‐screw extrusion showed similar tensile properties to those of slit die extruded samples.

Blown extrusion of zein film with single‐screw extruder.     

Vanadium antimonate as a partial oxidation catalyst

The catalytic selective oxidation on vanadium antimonate oxides partially doped with titanium was studied. Solids with nominal composition VSbO₄, V_0.8SbTi_0.2O₄ and VSb_0.8Ti_0.2O₄ were prepared by solid-state reaction. The solids were characterised by sorptometry, X-ray diffraction (XRD), temperature programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS). Catalytic tests were carried out in a fixed-bed reactor using toluene and air as reactants. It was found that partial substitution of V or Sb by Ti produces changes in the unit-cell composition and the redox properties of the solids. A possible role for V and Sb in the reaction mechanism of partial oxidation was established. Vanadium sites (V⁴⁺) are involved in the incorporation of gaseous oxygen as lattice oxygen and hold the Sb sites in an oxidation state (Sb⁵⁺) high enough to insert the lattice oxygen in the hydrocarbon molecule. A relationship between activity and V⁴⁺/Sb⁵⁺ ratio of the unit-cell was found. The selectivity to benzaldehyde is correlated with the redox properties of the solids while the selectivity to total oxidation products could be interpreted by the site isolation theory.     

Quinoline-Dihydropyrimidin-2(1H)-one Hybrids: Synthesis,Biological Activity,and Mechanistic Studies

A novel class of quinoline-dihydropyrimidin-2(1H)-one (DHPM) hybrids was synthesized and in vitro antiplasmodial activity was evaluated against chloroquine sensitive (D10) and chloroquine resistant (Dd2) strains of Plasmodium falciparum, the human malaria parasite. The antiplasmodial activity was compared to previously reported DHPM based molecular hybrids. Dual mode of antiplasmodial action of the most active member has been evaluated through heme binding study and in silico docking in the active site of dihydrofolate enzymes (wild-type as well as mutant). Favourable pharmacokinetic parameters were predicted in the ADMET evaluation. The new hybrids were also tested against a number of DNA and RNA viruses. No antiviral activity was found, except for one hybrid that showed mild inhibitory activity against two strains of cytomegalovirus (AD-169 and Davis), The most active hybrid was found to be a selective inhibitor of the growth of P. falciparum as well as a modest inhibitor of varicella zoster virus in HEL cells. Cytotoxicity of all hybrids was assessed in HEL, HeLa, Vero, MDCK, and CRFK cell cultures.     

Scenario inspections

Scenarios help practitioners to better understand the requirements of a software system as well as its interface with the environment. However, despite their widespread use both by object-oriented development teams and human–computer interface designers, scenarios are being built in a very ad-hoc way. Departing from the requirements engineering viewpoint, this article shows how inspections help software developers to better manage the production of scenarios. We used Fagans inspections as the main paradigm in the design of our proposed process. The process was applied to case studies and data were collected regarding the types of problems as well as the effort to find them.

Influence of grape variety on the extraction of anthocyanins during the fermentation on skins

The extraction of anthocyanins in the fermentation on skins is conditioned by several factors, such as the grape composition and the enological practices. In this work, the varietal effect on the anthocyanins extraction was studied, considering a series of fermentation on skins of Tannat, Cabernet-Sauvignon and Merlot. The different anthocyanic structures have a different diffusion in the must, at least during first stages of maceration. The decrease of the proportions of cyanidin and peonidin during the first days, with a consequent increase of the malvidin and petunidin proportions was verified. The coumarates proportions increased after the first day of maceration in all the musts. However, the definitive proportions of each anthocyanic form are reached rapidly and remain constant after the second or third day of maceration. The anthocyanic fingerprint of the young wines obtained in classical fermentation on skins is characteristic of each grape variety, although their evolution follows the general tendencies indicated.     

Doping of lanthanum cobaltite by Mn: thermal,magnetic, and catalytic effect

Great differences in crystallographic phases, magnetic properties, and catalytic activity were detected in lanthanum cobaltite and cobaltite modified with the insertion of 10 wt.% of Mn. Atomic absorption spectroscopy, BET area measurements, XRD analysis, TPR, and FT-IR suggest that the total insertion of manganese in the LaCoO₃ structure is successful. Thermal stability is reached for LaCo_0.90Mn_0.10O₃ up to 973 K without loss of the perovskite structure. The magnetic properties of the as-grown compounds are maintained after a first reduction process up to 723–773 K, while presence of segregated phases is observed after reduction at 973 K. The catalytic activity evaluated in the total combustion of acetyl acetate shows a decrease in the ignition temperature, i.e. an increase in the catalytic activity for the LaCo_0.90Mn_0.10O₃ perovskite. A significant enhancement in the catalytic activity expressed as intrinsic activity, mol m⁻² h⁻¹, with the manganese substitution was found.