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关键词： bioadhesive   fast curing   injectability   interface chemistry   methacrylated catechol‐   containing hyaluronic acid hydrogel   single network hydrogel   soft tissue  

摘要： Attaching hydrogels to soft internal tissues is crucial for the development of various biomedical devices. Tough sticky hydrogel patches present high adhesion, yet with lack of injectability and the need for treatment of contacting surface. On the contrary, injectable and photo-curable hydrogels are highly attractive owing to their ease of use, flexibility of filling any shape, and their minimally invasive character, compared to their conventional preformed counterparts. Despite recent advances in material developments, a hydrogel that exhibits both proper injectability and sufficient intrinsic adhesion is yet to be demonstrated. Herein, a paradigm shift is proposed toward the design of intrinsically adhesive networks for injectable and photo-curable hydrogels. The bioinspired design strategy not only provides strong adhesive contact, but also results in a wide window of physicochemical properties. The adhesive networks are based on a family of polymeric backbones where chains are modified to be intrinsically adhesive to host tissue and simultaneously form a hydrogel network via a hybrid cross-linking mechanism. With this strategy, adhesion is achieved through a controlled synergy between the interfacial chemistry and bulk mechanical properties. The functionalities of the bioadhesives are demonstrated for various applications, such as tissue adhesives, surgical sealants, or injectable scaffolds.

关键词： Ulva pertusa Kjellm   Ulvan   Extraction methods   Yields   Antioxidant activity   Polysaccharide characterization  

摘要： The present study investigated the effect of extraction conditions (including hot water-HW, ultrasonic assistedUA, enzyme assisted-EA and ultrasonic-enzyme assisted-UEA) on the yields, chemical composition, rheological properties and antioxidant activities of ulvan. The yields obtained by the above four extraction methods ranged from 17.88% to 26.77%. The use of enzymes helped to improve the yields of extraction, and through ultrasonicenzyme treatment, the maximum yield was obtained (26.7%). It was found that ulvan primarily consisted of sugar (41.9%?51.3%), uronic acid (14.1%?19.7%), protein (2.4%?3.3%) and ash (21.2%?24.9%), and the neutral sugars largely comprised rhamnose (22.4%?29.5%), xylose (10.0%?13.3%), glucose (5.0%?8.2%) and galactose (0.3%?0.5%). The results of the rheological measurements revealed that ulvan (4%, w/w) extracted by enzyme-assisted, ultrasonic-enzyme-assisted, ultrasonic-assisted and hot water treatment exhibited the stable shear viscosities of 24.5, 29.2, 56.7 and 95.2 mPa?s, respectively. Furthermore, ulvan extracted by enzymeassisted and ultrasonic-enzyme-assisted treatment showed visible DPPH radical scavenging ability over that extracted by hot water extraction and ultrasonic-assisted treatment, especially that extracted by enzyme-assisted treatment (SC50 6.52 mg/mL). Overall, the physicochemical properties of ulvan could be significantly affected by extraction methods. Polysaccharide from Ulva pertusa Kjellm, for its anti-oxidation activities, has high application implication in the field of healthcare, and subsequent researches should discuss its bioactive functions.

关键词： Catfish oil   Biodiesel   Transesterification   Adsorption   Activated earth   Fuel properties  

摘要： The effects of neutralization, transesterification, and adsorption on the physicochemical properties of fatty acid methyl esters (FAME) obtained from crude catfish oil (CO) were investigated. CO was recovered from catfish viscera and subjected to: neutralization (NCO) with 20 (g/100 g) NaOH solution, transesterification (BIO) with methyl alcohol (1:6 molar ratio, oil: alcohol) and 1 (g/100 g) (w/w) NaOH, and purification by adsorption (PBIO) with activated earth (10 g/100 g of BIO). CO, NCO, BIO, and PBIO were evaluated for FAME, free fatty acids (FFA), peroxide value (PV), cloud and flash points, free and total glycerin, rheological properties, and minerals. Catfish viscera had a lipid content of 28.5 g/100 g (wet basis), of which 20.9 g were recovered as CO (73.33% yield). Furthermore, 84.67 g of NCO, 77.53 g of BIO, and/or 60.22 g of PBIO were produced from 100 g of CO processed. NCO had significantly (P < 0.05) lower FFA, density, cloud point, flash point, and diacylglycerols content than CO. Meanwhile, PBIO had significantly (P < 0.05) lower PV and cloud points when compared to BIO. CO, NCO, BIO, and PBIO behaved as Newtonian fluids at 25 degrees C. BIO and PBIO adhere to the american society for testing and materials (ASTM) biodiesel standards for FAME, moisture, density, cloud point, free and total glycerin, Na, P, and S. This study demonstrated the feasibility of converting high-viscosity CO into low-viscosity PBIO with promising physicochemical attributes. PBIO has the potential to serve as a viable alternative biofuel.

关键词： epoxy oligomer   modification   plasticizer   filler   magnesite   physicochemical and mechanical properties  

摘要： The efficiency of application of magnesite as an active filler of an epoxy polymer has been proved, which improves strength and changes physicochemical properties of epoxy composites. The optimal content of magnesite as a structuring additive and as a filler in the epoxy composition (0.1 and 100 wt %) was selected, at which magnesite strengthens the epoxy composite. It has been found that the introduction of magnesite into the epoxy composite leads to an increase in the Vicat heat resistance from 132 to 148-216 degrees C, increases the thermal stability of the epoxy composite, therewith a shift in the initial temperature of destruction to the region of higher temperatures occurs. In addition, thermal destruction of the composite improves the yield of carbonized structures (from 54 to 70-83 wt %), which prevent the release of volatile pyrolysis products into the gas phase thereby result in a decrease in the flammability of the epoxy composite.

关键词： Early- successional and late-successional species   Stand development gradient   Soil depth   Basal area   Soil nitrogen   Soil C and N stocks  

摘要： The main objective of the study was to investigate influence of Nepalese alder (Alnus nepalensis D. Don) on fine root biomass (diameter <= 2 mm) dynamics and the physical and chemical properties of the soil in white oak (Quercus leucotrichophora A. Camus) forests. Five representative stands of each oak mixed alder (OMA) and oak without alder (OWA) were selected along the stand development gradient in the Indian central Himalaya. Fine root and soil samples from of 0-10 cm, 10-20 cm, and 20-30 cm depths were collected using soil core method. Soil physical and chemical properties and monthly variations in fine root dynamics (biomass distribution and decomposition) were analyzed. Fine root decomposition was studied by using the litterbag technique. Redundancy and correlation analyses were performed to evaluate the relationship between fine root dynamics, stands, and tree total basal area and soil properties. Both the fine root biomass and production of Q. leucotrichophora were significantly (P < 0.05) higher for oak without alder stands than oak mixed alder stands. Fine mot biomass, production, and turnover rate of A. nepalensis were significantly (P < 0.05) higher than Q. leucotrichophora in oak mixed alder stands. Within the investigated soil profile, in all the sites, maximum fine root biomass and production were found in the upper (0-10 cm) soil depths. The analyses revealed clear differences in all the measured soil physical and chemical properties and fine root traits in oak mixed alder and oak without alder stands. The soil organic carbon (SOC), total nitrogen (TN) contents, and soil C and N stocks were significantly (P < 0.05) higher in oak mixed alder stands than oak without alder stands while opposite trends were found for soil pH and bulk density (BD). Present findings reveal that improvement of the soil properties under oak mixed alder stands was significantly higher than the oak without alder stands. Fine root decomposition for A. nepalensis was significant

关键词： Polishing   Milling speed   Milling duration   Physicochemical properties  

摘要： Effect of polishing condition during milling of rice on the properties of rice starch was investigated. Waxy, lowand high-amylose rice were polished with different milling speeds (750, 950 and 1050 r/min) and milling durations (20, 40 and 60 s) to obtain polished rice. Rice starches were extracted from the polished rice. Swelling power and solubility index of low- and high-amylose rice starches increased with milling speed and duration compared with unpolished rice starches. However, for waxy rice starch, there was no significant change. The peak, trough and final viscosities decreased for waxy rice starch and increased for high-amylose rice starch with increased polishing, whereas those of low-amylose rice starch increased first and then decreased. Polishing induced greater pseudoplasticity in starch relative to that from unpolished rice. Polishing duration during milling caused greater changes in swelling behavior and pasting properties, whereas polishing duration caused greater effects on structural properties. This study showed that both polishing speed and duration impacted the physicochemical and rheological properties of different rice starches, but to a different extent.

关键词： Slag   Welding electrode   Characterization   Regression analysis  

摘要： The work is aimed at characterizing the properties of slag obtained from CaO-CaF2- TiO2-SiO(2)based coatings developed for welding the offshore structures. Extreme vertices methodology was used to formulate coating compositions. Iron ore waste red ochre has been used as source of iron in the coating. The slag has been characterized for thermal stability, density, specific heat, enthalpy of reaction, thermal conductivity behavior, and thermal diffusivity. Welding slag was also structurally analyzed for different phases and bonds. Silicate ion (SiO44-) has been found to influence all the slag properties significantly. Effect of coating constituents has been studied using regression analysis. Mineral constituents and their interactions were found to have influential role on thermo-physical, chemical and structural behavior of slags.

关键词： Microcrystalline cellulose   Date palm frond   MCC isolation   Delignification   thermal properties   Crystallinity  

摘要： In this study, pure cellulose was isolated from Algerian date palm fronds (DPF) using three different delignification processes (acidified NaClO2, totally chlorine free (TCF) and their combination). Then, microcrystalline cellulose (MCCs) particles have been successfully produced via direct acid hydrolysis of the different celluloses. All samples were characterized using infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry (TGA) and differential scanning calorimeter (DSC). From the FTIR analysis, most of hemicellulose and lignin were effectively removed throughout the extraction processes. The XRD spectra revealed that all MCCs belong to cellulose I type, and showed a highly crystallinity index than that of pure celluloses. According to DSC and TGA/DTG analyses, the MCC samples presented a higher decomposition temperature. The obtained results showed that the extracted MCC samples exhibited similar properties than those of commercial MCC. Furthermore, the employment of a combined process allowed obtaining MCC with higher crystallinity and better thermal stability. Thus, according to these results, date palm fronds can be considered as a potential low-cost material for MCC production and the combined process is promising to isolate high purity MCC from cellulosic substrate. [GRAPHICS] .

关键词： Solubility  

摘要： Two derivatives of adamantane benzenesulfamide have been synthesized and studied: N-adamantane-1-yl-2,4,6-trimethyl-benzenesulfamide (1) and N-adamantane-1-yl-4-methoxy-benzenesulfamide (2). Crystal structures 1 and 2 are solved using X-ray diffraction (XRD) analysis. The solubilities of compounds in a phosphate buffer solution with pH 7.4, 1-octanol, and n-hexane are determined at several temperature points using isothermal saturation. The values of Gibbs energy, enthalpy, and entropy of solubility of the compounds at 298 K are determined.

关键词： Colour   Milk gel   Texture   Nonthermal processing   Ultrasound   Syneresis   Viscosity  

摘要： The influence of sonication conditions (amplitude of ultrasound probe = 50, and 75%, time = 5, 10 and 15 min and temperature = 45, 55 and 65 oC) on the properties of yoghurt was investigated. The apparent viscosity, hardness and lightness increased when sonication time, temperature and amplitude increased. At 75% of amplitude, the pH, syneresis and flavour decreased but acidity, adhesiveness, cohesiveness, springiness, chewiness, redness, yellowness and overall acceptance increased. As the sonication temperature increased, acidity, syneresis, adhesiveness and yellowness decreased. Based on the physicochemical and sensorial results, sonication at 55 degrees C, 10 min and 75% of amplitude, effectively improved the properties of yoghurt.