Fabrication of Polyurethane/Polylactide (PU/PLDL) Nanofibers Using Electrospinning Method

Polylactide and aliphatic polyurethane are biodegradable synthetic polymers which are broadly used as biomaterials in regenerative medicine for implants and scaffolds for tissue engineering. In this paper, the detailed studies of the fabrication of the electrospun fibers of polyurethane/polylactide mixtures were described. The influence of the used solvent (dimethylformamide (DMF)) and diluents (acetone and dichloromethane (DCM)) on the rheological parameters and electrospinning of the described mixtures was examined. Rheological studies showed that polyure-thane/polylactide mixtures have mostly non-Newtonian character, strongly influenced by the diluent. Solutions containing 50 wt.% or more of polyurethane became less viscous after the addition of DCM or acetone, whereas those with bigger amount of polylactide showed higher viscosity after the addition of DCM and lower viscosity after the addition of acetone. Optimized electrospinning process has been elaborated. Fibers with diameters from 250 nm up to 1 µm have been produced and compared. Pure acetone worsened the electrospinning process, but the more DCM was in the mixture, the thinner and more aligned fibers were produced.

Comparative histophysiological study the effective treatment of induced eczema in rats that treated with Lanolin and glycerine with Vaseline in rats

The present study has been designed to evaluate the potent role of healing efficacy of lanolin (which is also called wool wax), is an oily product secreted by the sebaceous glands beneath the skin of sheep which is have anti-inflammatory, anti-microbial, skin protecting properties, a forty-eight mature albino rats (weighted 250-350 g) were randomly assigned to two groups; control group and eczema group which is induced by 99.9% pure acetone. By squad cotton and put it on shaved skin, after 3 days of acetone application the eczema group were divided randomly into two equal groups each group 16 rats, treat these 32 rats with glycerin and lanolin, after 24h five rats from each group were sacrificed, and remaining rats were treated with glycerin and lanolin for 72h and then sacrificed at the third day, the histopathology there is a lot of histopathological changes occur in tissue section in eczematous skin in comparison with control section; there were obvious thickness and enlargement in the length of outermost layer of skin, also there is fissures and cracks in the epidermal layer due to the dryness of skin and aggregation of inflammatory cells. And as well as keratinization of epithelial layer and changes in skin color, the results indicate there were optimum healing effect of lanolin group in compare with glycerin group after 72h, Showed back the outer most layer of the skin to its normal length, also decrease in inflammatory cells number.

Optimal Aqueous Extraction Conditions as A Green Technique for Recovery of Phenolic Antioxidants from Robusta Dried Coffee Pulp

Coffee pulp, a by-product of coffee processing, contains high level of flavonoids and other phenolic compounds. This by-product also contains high levels of other bioactive compounds such as chlorogenic acids and caffeine, which can be potentially recovered for further applications. This study used water as an inexpensive green solvent, for the maximum recovery of phenolics, major bioactive compounds and antioxidant capacity from coffee pulp. Recovery yield from optimal aqueous extraction was compared with organic solvent extraction. The results showed that temperature, extraction time and solid/solvent ratio significantly affected recovery yields from coffee pulp (P<0.05). Optimal aqueous extraction conditions were 100 °C, 60 min and the ratio of sample to solvent 1:100 g/mL. Under these optimal conditions, recovery yields were similar to those of 50% aqueous acetone extraction. Recovery yields were significantly higher than pure acetone, methanol and ethanol as well as methanol and ethanol in combination with water (50% v/v). Therefore, these optimal aqueous conditions are recommended for recovery of bioactive compounds from coffee pulp for further applications.

Comparative Extraction Efficacy of Different Organic Solvents for Leaf Chlorophylls and Carotenoids in (Portulaca oleracea L.) Varying with Growth Behavior and Stress Type

The chlorophyll is one of the most important natural pigments used extensively in the food industry. Two important factors for the production of chlorophyll are the use of plants rich in chlorophyll and efficiency of extraction method. Present investigation was performed to compare the extraction of photosynthetic pigments by using solvents of different chemical nature. The purslane plants with different growth behavior viz. Scrollable and standing were grown under shade and sunshine stress condition. Different solvents including diethyl ether, 5% ethanol, pure acetone, 20% acetone, pure methanol and 10% methanol were used to extract chlorophyll and carotenoids from the purslane plant. The results indicated that stress, growth type and different solvents had a significant effect on the extraction of chlorophyll and carotenoids. Different trend was observed in extraction rate for chlorophylls and carotenoids. Among the solvents, pure methanol was the best for extraction of chl a. Methanol and acetone were appropriate solvents to achieve the highest amount of chlorophyll from plant tissues. Among different solvents, pure methanol for chl a, pure acetone and methanol for carotenoids were best solvent for purslane plant with a growing type scrollable of under shade.

A fast method to prepare microslides of wood in advanced stages of decay

ABSTRACTBiologically degraded wood in advanced stages of decay has a very soft and brittle structure that causes many problems during sectioning. Embedding wood specimens in different kinds of media ensures preparation of good quality microsections, but the preparation time is very long. The proposed method does not only have a reduced preparation time but also minimizes costs and consumption of chemicals while improving stabilization of the specimen and enhancing the quality of sections. The crux of the method is application of a reinforcing layer of transparent nail polish gel on a dry specimen that has been only stabilized (not embedded) with PEG 1500 medium. The gel is applied on a specimen in two layers just before sectioning. The first layer infiltrates the specimen sufficiently deep to fill the lumens and cell walls and allows preparation of thin sections from decayed wood. The second layer reinforces the section and allows better handling. Subsequently, the reinforcing and embedding layers are removed using pure acetone. This innovative method has so far been successfully tested on specimens that were degraded by the fungusPleurotus ostreatus(mass loss 55% and 83%) and the fungusPhaeolus schweinitzii(mass loss 45%), taken fromFagus sylvaticaandPinus sylvestrisspecies, a hardwood and softwood respectively with contrasting wide vessels and narrow tracheids.

A model for mono- and multi-component droplet heating and evaporation and its implementation into ANSYS Fluent.

A model for heating and evaporation of mono- and multi-component droplets, based on analytical solutions to the heat transfer and species diffusion equations in the liquid phase, is summarised. The implementation of the model into ANSYS Fluent via User-Defined Functions (UDF) is described. The model is applied to the analysis of pure acetone, ethanol, and mixtures of acetone/ethanol droplet heating/cooling and evaporation. The predictions of the customised version of ANSYS Fluent with the newly implemented UDF model are verified against the results predicted by the previously developed in house, one-dimensional code.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4759

Solution thermodynamics and preferential solvation of 3-chloro-N-phenyl-phthalimide in acetone + methanol mixtures

The thermodynamic properties of the 3-chloro-N-phenyl-phthalimide in acetone+ methanol cosolvent mixtures were obtained from solubility data report in literature. The solubility was higher in near acetone and lower in pure methanol at all temperatures studied. A non-linear plot of ∆ from pure acetone up to x 1 soln H° vs. ∆ soln 2, Gerson G° shows a negative slope = 0.691. Beyond this composition, a variable positive slope is obtained with the exception of mixtures with x 1 = 0.121, x1 = 0.272 and x 1= 0.356 which is a not common trend in these systems. The preferential solvation of 3-chloro-N-phenyl-phthalimide by the components of the solvents was estimated by means of the inverse Kirkwood–Buff integral method, showing the 3-chloro-Nphenyl-phthalimide is preferential solvated bymethanol in more polar mixtures and by acetone in less polar ones.

Pool Nucleate Boiling of Acetone and Acetone/Ethanol Mixture on Magnesium Alloy Surface

In this paper, the pool nucleate boiling performance of acetone and acetone/ethanol mixture on a magnesium alloy surface is studied experimentally. The pure acetone and the mixtures with two different mixing ratios are tested. A uniform heat flux is provided through the magnesium alloy tube to heat the mixtures around the magnesium tube surface. The general aim of this classic heat transfer experiment is to investigate the heat transfer performance of the binary fluids on the magnesium alloy surface, and the compatibility of the binary fluids with magnesium alloy. The results show that pure acetone presents better heat transfer performance than its mixtures. Compared two mixtures, the difference of 10% concentration of acetone (90% or 80%) do not result in a huge change of heat transfer coefficient. The scanning electronic microscope (SEM) observation suggested that either the pure acetone or acetone/ethanol mixtures could be used as working fluids of magnesium (Mg) alloy heat pipes.

Glutathione and zeaxanthin formation during high light stress in foliose lichens

In the presented study, we describe techniques for glutathione and pigment determination in lichens used in our laboratory. Glutathione and xanthophyll cycle pigments, especially zeaxanthin, are important antioxidants protecting plants against various stresses. In our laboratory, the high light stress in lichens has been intensively studied for several years. We extract glutathione in HCl and determine it by thiol-binding fluorescence label monobromobimane. For pigment determination, homogenized lichen thalli are extracted with pure acetone. According to our results, the total amount of glutathione decreases after a short-term high light exposure, while the amount of zeaxanthin increases.