Zn(II) adsorption from synthetic solution and kaolin wastewater onto vermicompost

The adsorption of Zn(II) from both synthetic solution and kaolin industry wastewater by cattle manure vermicompost was studied. The adsorption process was dependent on the various operating variables, viz., solution pH, particle size of the vermicompost, mass of vermicompost/volume of the Zn(II) solution ratio, contact time and temperature. The optimum conditions for Zn adsorption were pH 6.0, particle size of < or = 250 microm, 1 g per 10 mL adsorbent dose, contact time of 4h and temperature of 25 degrees C. Langmuir and Freundlich adsorption isotherms fit well in the experimental data and their constants were evaluated, with R(2) values from 0.95 to 0.99. In synthetic solution, the maximum adsorption capacity of the vermicompost for Zn(2+) ions was 20.48 mg g(-1) at 25 degrees C when the vermicompost dose was 1 g 10 mL(-1) and the initial adjusted pH was 2. The batch adsorption studies of Zn(II) on vermicompost using kaolin wastewater have shown the maximum adsorption capacity was 2.49 mg g(-1) at pH 2 (natural pH of the wastewater). The small values of the constant related to the energy of adsorption (from 0.07 to 0.163 L mg(-1)) indicated that Zn(2+) ions were binded strongly to vermicompost. The values of the separation factor, R(L), which has been used to predict affinity between adsorbate and adsorbent were between 0 and 1, indicating that sorption was very favorable for Zn(II) in synthetic solution and kaolin wastewater. The thermodynamic parameter, the Gibbs free energy, was calculated for each system and the negative values obtained confirm that the adsorption processes are spontaneous. The DeltaG degrees values were -19.656 kJ mol(-1) and -16.849 kJ mol(-1) for Zn(II) adsorption on vermicompost in synthetic solution at pH 6 and 2, respectively, and -13.275 kJ mol(-1) in kaolin wastewater at pH 2.     

Short communication: Association between the accessory gene regulator (agr) group and the severity of bovine mastitis caused by Staphylococcus aureus

Staphylococcus aureus can elicit mild to more severe degrees of mastitis in cattle, depending on the response of the host's immune system and the virulence factors of the specific isolate. Several virulence factors are controlled by a global regulatory system, designated accessory gene regulator (agr). Thus, the objective was to examine associations between different capsular and agr types and the severity of bovine mastitis caused by S. aureus. All isolates were obtained from bovine subclinical (n = 50), mild clinical (n = 73), and moderate clinical mastitis cases (n = 28). Isolates containing the agrI gene and lacking the agr locus (agr^?) were more prevalent among subclinical than clinical mastitis cases, whereas isolates containing the agrII and agrIII genes were more prevalent among clinical mastitis cases. The capsular types 5 (cap5) and 8 (cap8) were found in 42 and 44%, respectively, of the isolates obtained from subclinical cases and in 38.6 and 58.4%, respectively, of those isolated from clinical mastitis cases. Capsular type was not associated with type of mastitis (subclinical, mild clinical, or moderate clinical). We found a strong association between agr type and type of mastitis, suggesting that knowledge of S. aureus genetic profiles could be an additional tool to control this disease.     

Self-healing polymer blend based on PETG and EMAA

In this work, novel immiscible polymer blends with remarkable self-healing properties were developed. The blends are based on poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG), a nonself-healing polymer, and the ionomer sodium-neutralized poly(ethylene-co-methacrylic acid) (EMAA), with self-healing abilities. The ratios of (PETG)/ (EMAA) was varied from 0 to 100% (w/w) and mixtures were prepared using a twin-screw melt extrusion. The blend studied compositions were characterized by scanning electron microscope, differential scanning calorimetry, dynamic mechanical analysis and self-repair tests. The results revealed that blends samples were able to self-repair damages created by Vickers microhardness indentations. The self-repair is presented through video records where the establishment of scars in the damaged area can be observed. For the composition 50/50 (w/w), the whole repair was observed due the synergic effect between polymer chain mobility, new chemical interactions promoted between PETG and EMAA, thus improving its self-healing ability.     

Evaluation of acrylic acid grafting on the loading and release of scopolamine butylbromide from polymeric matrices for future sialorrhea treatment

Sialorrhea is a disorder which causes an increase in salivation. Scopolamine butylbromide (SBB) can be administrated to treat sialorrhea and its transdermal application minimizes the occurrence of side effects. This work compared SBB adsorption and release from two polymer matrices, polycaprolactone and natural rubber latex, as well as the matrices modified by gamma irradiation-induced graft copolymerization of acrylic acid (AAc). Grafting with AAc-introduced carboxylate groups onto the surface of the matrices evident from chemical analysis and resulted in increased hydrophilicity evident from contact angle measurements. SBB adsorbed to the matrices without changing its structure and for the AAc-grafted matrices this was governed by electrostatic interactions. Higher SBB loading was observed for the AAc-grafted matrices while SBB release was slower for the non-grafted matrices than the grafted matrices. The four different matrices produced are candidates for the development of a transdermal drug delivery system.     

Electrospun progesterone-loaded cellulose acetate nanofibers and their drug sustained-release profiles

Novel cellulose acetate (CA) nanofibers incorporated with hormone progesterone (P₄) were prepared by electrospinning and its potential as a controlled release system for medicine and veterinary was evaluated by controlled release essay. The morphology, thermal behavior, and structure of P₄-loaded CA nanofibers were characterized by scanning electron microscopy, differential scanning calorimetry, and Fourier-transform infrared spectroscopy. The analyses revealed that the incorporation of P₄ increased nanofibers' diameter from around 340 to 892 nm to 8% w/w P₄-loaded CA nanofibers. Furthermore, P₄ has demonstrated high interaction with CA affecting its crystalline structure, since pure CA nanofibers presented 67.23% of crystallinity while P₄-loaded CA nanofibers where amorphous. Ultimately, the drug release essay demonstrated a two-stage profile, and regarding release kinetics, the samples evidenced a diffusion mechanism depending on P₄ concentration in the nanofiber.     

Short-Term Administration of a High-Fat Diet Impairs Wound Repair in Mice

High intake of dietary fat plays an important role in obesity development in animals and humans, and prolonged intake of high-fat diet might lead to low-grade chronic inflammation. Previous study showed that diet-induced overweight delays cutaneous wound healing in both obesity-prone and obesity-resistant animals, highlighting the importance of diet composition in the wound healing process. This study evaluated the hypothesis that a short-term administration of high-fat diet could affect cutaneous wound healing. Male mice (C57/bl6) were randomly divided into standard (10% energy from fat) or high-fat (60% energy from fat) chow groups. After 10 days of diet administration, an excisional lesion was performed and the animals were sacrificed 6 or 10 days later. There was no difference in the fasting blood glucose between groups. Ten days after wounding, high-fat chow group presented increased inflammatory infiltrate, levels of inducible nitric oxide synthase and cyclo-oxygenase-2 proteins, and lipid peroxidation. The high-fat chow group presented delayed wound closure, increased amount of myofibroblasts and vessels, and decreased deposition of type I collagen. These findings support the hypothesis that short-term administration of high-fat diet exerts negative effects on mice cutaneous wound healing, due to the interference in the inflammatory phase.     

Ascorbic Acid Supplementation Improves Skeletal Muscle Growth in Pacu (Piaractus mesopotamicus) Juveniles: In Vivo and In Vitro Studies

In fish, fasting leads to loss of muscle mass. This condition triggers oxidative stress, and therefore, antioxidants can be an alternative to muscle recovery. We investigated the effects of antioxidant ascorbic acid (AA) on the morphology, antioxidant enzyme activity, and gene expression in the skeletal muscle of pacu (Piaractus mesopotamicus) following fasting, using in vitro and in vivo strategies. Isolated muscle cells of the pacu were subjected to 72 h of nutrient restriction, followed by 24 h of incubation with nutrients or nutrients and AA (200 µM). Fish were fasted for 15 days, followed by 6 h and 15 and 30 days of refeeding with 100, 200, and 400 mg/kg of AA supplementation. AA addition increased cell diameter and the expression of anabolic and cell proliferation genes in vitro. In vivo, 400 mg/kg of AA increased anabolic and proliferative genes expression at 6 h of refeeding, the fiber diameter and the expression of genes related to cell proliferation at 15 days, and the expression of catabolic and oxidative metabolism genes at 30 days. Catalase activity remained low in the higher supplementation group. In conclusion, AA directly affected the isolated muscle cells, and the higher AA supplementation positively influenced muscle growth after fasting.     

Endothelins inhibit cyclic-AMP induced renin gene expression in cultured mouse juxtaglomerular cells

We have recently described that endothelins-1 to -3 equipotently inhibit cAMP stimulated renin secretion from cultured mouse juxtaglomerular cells by a process involving phospholipase C activation. This study examined the influence of endothelin-2 on renin gene expression in renal juxtaglomerular cells. To this end we semiquantitated renin mRNA levels by competitive RT-PCR in primary cultures of mouse renal juxtaglomerular cells after 20 hours of incubation. We found that endothelin-2 (0.1 to 100 nmol/liter) did not change basal renin gene expression. The adenylate cyclase activator forskolin (3 mumol/ liter) increased renin mRNA levels to 400% of the controls and this stimulation was dose-dependently attenuated by ET-2 to 250% of the control value. The effect of ET-2 was mimicked by the ETB-receptor agonist sarafotoxin S6c. The kinase inhibitor staurosporine (100 nmol/ liter) increased renin secretion and renin mRNA levels. Combination of staurosporine with forskolin produced the same effects on renin secretion and renin mRNA levels as did staurosporine alone. In the presence of both forskolin and staurosporine ET-2 had no significant effect on renin secretion and renin gene expression. The phorbol ester PMA (30 nmol/ liter), which was used to stimulate protein kinase C activity, attenuated cAMP stimulated renin secretion and renin mRNA levels. Lowering the extracellular concentration of calcium by the addition of 1 mmol/liter EGTA did not inhibit the effect of ET-2 on cAMP induced renin secretion and renin gene expression. These findings suggest that endothelins inhibit cAMP stimulated renin gene expression by an event that is mediated via ETB receptors. This inhibitory effect may in part involve protein kinase C activation.     

Development of biodegradable PLA/PBT nanoblends

Poly(lactic acid)/poly(butylene terephthalate) (PLA/PBT) blends with 3, 5, and 10 wt % of PBT were produced in a twin‐screw extruder, with the addition of ethylene–glycidyl methacrylate copolymer as compatibilizer. An uncompatibilized PLA/PBT blend with 5 wt % of PBT was prepared for comparison studies. The epoxy reactive groups in the compatibilizer allowed modification of the interfacial tension in the blends and reduced the PBT dimensions. The crystallinity of the blends was studied, and its influence on mechanical properties was analyzed. Tensile tests showed an increase in strain at break from 3% for neat PLA to 49% for PLA with 3 wt % PBT, while the tensile modulus dropped from 3.59 GPa to 3.35 GPa for the same samples. Izod results showed a transition from a brittle behavior of PLA to a ductile one for compatibilized blends. These results indicate that the nanometer‐size dispersed phase was effective in changing the deformation behavior of the matrix without a significant loss of modulus. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45951.     

Spraying Cellulose Nanofibrils for Improvement of Tensile and Barrier Properties of Writing & Printing (W&P) Paper

An experimental spray coater was used to coat writing and printing (W&P) paper substrate with cellulose nanofibrils (CNFs) suspensions. The effects of spraying variables (i.e. concentration of suspension, spray pressure, distance and time of spray) on the coated sheets were analyzed in terms of the tensile strength, water vapor transmission rate (WVTR), and oxygen transmission rate (OTR). Basis weight and the thickness of coated layers in the different treatments were measured. In addition, image analysis of the microstructure examined the coating adhesion. The WVTR of the papers decreased, while tensile strength increased with one layer of CNF coating. The OTR was not changed with the CNF coating. The tensile strength and microstructure images of the coated papers indicate good adhesion between the CNF coating and the paper substrate when using the spray coater.