Current usefulness of procaine penicillin in the treatment of pneumococcal pneumonia

Kidney transplantation offers the opportunity of an improved quality of life for those patients suffering from renal failure. Unfortunately, this treatment is not available to all people as this is influenced by the increasing demand for a limited supply of suitable organs. This situation is particularly alarming for the UK's Asian population with their higher susceptibility to end-stage renal failure which has resulted in a greater demand for transplants. Consequently, the proportion of Asians on transplant waiting lists is growing rapidly. Coupled with this are problems of cross-racial tissue type matching which has led to longer waiting times for a transplant. The situation is clear, there is an urgent need to address the number of Asians requiring a kidney transplant otherwise the human and economic costs will be very severe. In the short term there needs to be a greater number of donors coming forward from the Asian communities to increase the pool of suitable organs. In the long term, there needs to be greater attention on preventive strategies to reduce the number of Asians requiring renal replacement therapy.     

Polylactones

Summary Bulk polymerizations of L,L-lactide were conducted at 120 and 180°C, but mainly at 150°C. Magnesium oxide, ethoxide, acetate, stearate, and 2,4-pentane dionate were used as catalysts. Time conversion curves show that at least a temperature of 150°C and a reaction time of 72 h is required for maximum conversion. The highest yields (up to 96 %) were obtained with magnesium oxide. However, all initiators, in particular magnesium oxide, caused racemization which increased with reaction time and temperature. Polymerizations in solutions at temperatures around 100°C failed regardless of the solvent.     

Preparation and properties of biocomposites based on jute fibers and blend of plasticized starch and poly(β‐hydroxybutyrate)

In this work, preparation and properties of biocomposites based on jute fibers and blend of plasticized starch and poly(β‐hydroxybutyrate) (PHB) have been investigated. Different amounts of glycerol and aliphatic polyesters (PHB) have been added to native starch to obtain a processable biodegradable matrix. In the same way natural jute fibers up to 30 wt % loading were added to improve the mechanical and thermal stability of the material. Tensile mechanical, thermal, and thermomecahnical analyses have been performed to characterize the ensuing materials. Significant enhancement in the mechanical properties and water sensitivity were noted by the addition of 8 wt % PHB. The fibers incorporation into the biopolymer matrix brings about an increase in both the mechanical strength and modulus as much higher as the fibers loading is important. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

The use of dihydrazides as latent curing agents in diglycidyl ether of bisphenol A coatings

Dihydrazides of different structure were synthesized and tested as curing agents for DGEBA epoxy coatings. By calorimetric studies their latent characteristics were proved and the kinetics of the curing studied. The temperatures of activation are usually dependant on the melting point of the dihydrazide. The acceleration by base and Lewis acids was proved, but the latent character was diminished. FTIR/ATR allowed characterizing the final structures of the thermosets and confirming that the fully cured was achieved. The thermal stability of the materials and their thermomechanical characteristics were evaluated by TGA and DMTA, respectively. Mechanical properties of the thermosets were also determined.     

Epoxy/anhydride networks modified with polyhedral oligomeric silsesquioxanes

Epoxy/anhydride networks were modified, in the presence of benzyldimethylamine as catalyst, with two polyhedral oligomeric silsesquioxanes (POSS), whose inorganic framework had a compact and stable Si‐O core and an organic substituent shell. The influence of the content and type of POSS during curing and on the properties of the thermosets was investigated by thermal analysis and infrared spectroscopy. The curing kinetics was analyzed by means of an integral isoconversional nonisothermal procedure. When the POSS modifier was added, the storage modulus in the rubbery plateau increased and the glass transition temperature decreased because of the presence of the flexible organic moieties and the influence in the crosslinking density. The presence of these POSS structures hardly affected the thermodegradation behavior of cured materials. The dispersion of the POSS structures in the epoxy/anhydride matrix was good, but some submicron‐sized POSS agglomerates could be observed by transmission electron microscopy. POLYM. COMPOS., 2013. © 2012 Society of Plastics Engineers     

Effect of tasting and information on consumer opinion about pig castration

Our research explored the relative importance of pig castration amongst other aspects of animal welfare, and the potential impact of information and sensory experiences on European Union (EU) consumers' preferences. The EU is considering a future ban on surgical pig castration by 2018 which may affect markets and consumers' preferences. We carried out an empirical study using consumer-level data obtained from questionnaires completed in a controlled environment by a total of 825 consumers. The experiment was carried out in six EU countries (Spain, United Kingdom, The Netherlands, France, Italy and Germany) which account for 66.0% of the EU-27's and 76.3% of the EU-15's meat production. Results show that consumers do not perceive pig castration to be a relevant aspect of animal welfare nor its relationship with meat quality. Consumers with healthy life styles, concerned about animal welfare and who have had a negative sensory experience with boar meat are willing to accept paying more to avoid boar taint.     

Novel thermal curing of cycloaliphatic resins by thiol–epoxy click process with several multifunctional thiols

Novel thermosets were prepared by the base‐catalysed reaction between a cycloaliphatic resin (ECC) and various thiol crosslinkers. 4‐(N,N‐Dimethylaminopyridine) (DMAP) was used as base catalyst for the thiol–epoxy reaction. A commercial tetrathiol (PETMP) and three different thiols synthesized by us, 6SH‐SQ, 3SH‐EU and 3SH‐ISO, were tested. 6SH‐SQ and 3SH‐EU were prepared from vinyl or allyl compounds from renewable resources such as squalene and eugenol, respectively. Thiol 3SH‐ISO was prepared starting from commercially available triallyl isocyanurate. A kinetic study of the mixtures was performed using differential scanning calorimetry. Stoichiometric ECC/thiol/DMAP formulations were cured at 120 °C for 1 h, at 150 °C for 1 h and post‐cured for 30 min at 200 °C. The materials were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis and dynamic mechanical thermal analysis. The results revealed that the materials obtained from the synthesized thiols had higher thermal stability and glass transition temperatures than those obtained from the commercial PETMP. In addition, all the materials obtained exhibited very good transparency. This study proves the ability of multifunctional thiols to crosslink cycloaliphatic epoxy resins, leading to more flexible materials than those obtained by cationic homopolymerization of ECC or base‐catalysed ECC–anhydride copolymerization. © 2017 Society of Chemical Industry     

Rhamnolipids Obtained from a PHA-Negative Mutant of Pseudomonas aeruginosa 47T2 ΔAD: Composition and Emulsifying Behavior

Pseudomonas aeruginosa 47T2 (NCBIM 40044) synthesizes polyhydroxyalkanoic acids (PHAs) and rhamnolipids (Rhls). The knockout mutant for PHAs biosynthesis, P. aeruginosa 47T2 ΔAD prepared in this study, increased the cellular yield of Rhls production by 28 %. The Rhls mixture (composed up to eight homologs) reduced the water surface tension to 31.67 mN/m with a critical micelle concentration of 105 mg/L. The IC₅₀ (μg/mL) of the neutral red uptake assay and methylthiazol tetrazolium assay ranged between 53.9 and 72 μg/mL, which is similar to that of sodium dodecyl sulfate (SDS). Rhamnolipids had a lower hemolytic effect at 110.8 μg/ml than SDS, a commercial anionic surfactant, at 43.6 μg/mL. This suggests that the Rhls mixture could be used in topical pharmaceutical and cosmetic applications or cleansers as a biosurfactant. The emulsifying properties in water/oil dispersions were determined using ternary phase diagrams at 25 °C. Isopropyl myristate, soybean oil, olive oil and Casablanca oil were used as the oil components. Total emulsions were obtained with most of the oils.     

Modification of epoxy–anhydride thermosets with a hyperbranched poly(ester amide). II. Thermal,dynamic mechanical,and dielectric properties and thermal reworkability

An epoxy–anhydride formulation used for the coating electrical devices was modified with a commercially available hyperbranched poly(ester amide), Hybrane S2200, to improve the thermal degradability of the resulting thermoset and, thus, facilitate the recovery of substrate materials after the service life of the component. The thermomechanical, mechanical, and dielectric properties and thermal degradability were studied and interpreted in terms of the composition and network structure of the cured thermosets. Although the crosslinking density was significantly reduced with the incorporation of S2200, the glass transition temperature of the fully cured material (T_g∞) of the modified thermoset was hardly affected because of the enhancement of H‐bonding interactions in the presence of S2200. Despite the different network structures, the combined dielectric and dynamic mechanical analysis revealed that the relaxation dynamics of both networks were very similar. In terms of application, improvements in the dielectric and mechanical properties were observed. The incorporation of S2200 accelerated the thermal decomposition of the material and, thus, facilitated the recovery of the valuable parts from the substrate at the end of the service life of the apparatus. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013