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关键词： Silkworm   silkworm pupae   amino acid profile   fatty acid   pasting properties   proximate composition  

摘要： This research was performed to examine selected nutritional quality and physicochemical properties of silkworm pupae. Frozen or powdered pupae from two species of silkworm (Bombyx mori and Samia ricinii) were studied. Eri had the largest size with the highest lightness and peak viscosity. The PCA (principal component analysis) total variance could be explained by 74.68%, and silkworm pupaes could be put into 2 clusters. Cluster 1: all varieties of frozen silkworm pupae having a high moisture content;Cluster 2: silkworm pupae powder. Thai and Hybrid silkworm pupae powder had the highest calcium, total fat and n-3, n-6 and n-9 fatty acids. Eri silkworm pupae powder had the highest protein, essential amino acid and crude fibre. Each variety of silkworm pupae had different properties that might be suitable for developing different food products. Therefore, the presented data would be advantageous for manufacturers for developing functional ingredients and novel foods.

关键词： Quantitative structure-activity relationships   Bioconcentration   Hazard   risk assessment   OPERA   Mordred   Machine learning  

摘要： Bioconcentration factors (BCFs) are indicators of the accumulation of chemical substances in organisms;they play an important role in the environmental risk assessment of various chemical substances. Experiments to obtain BCFs are expensive and time consuming;hence, it is desirable to predictively determine BCF during the early stage of chemical development. In this study, we developed a quantitative structure-activity relationship (QSAR) model using physicochemical properties, environmental fate endpoints, and molecular descriptors. Physicochemical properties and environmental fate endpoints were generated by OPERA, which is a QSAR software. Moreover, we calculated the molecular descriptors using Mordred. A gradient boosting decision tree model was developed as a machine learning model, and multiple linear regression and support vector machine models were developed for comparison. Our developed model showed that the coefficients of determination (R2) of the training and test sets were 0.923 and 0.863, respectively, which are higher than the predictions of the previous model and values calculated by OPERA. The results obtained from the present study suggest that an accurate QSAR model can be developed using the physicochemical properties, environmental fate endpoints, and molecular descriptors calculated from the chemical structure without actually conducting BCF experiments. The model could be one of the choice for the preliminary risk assessment without investing in a large number of BCF experiments during the early development stages of candidate chemicals.

摘要： Vaccination has milestone significance for the prophylactic and complete elimination of infectious diseases. However, combating malignant infectious diseases, such as Ebola or HIV, remains a challenge. It is necessary to explore novel technologies to facilitate the immune profile of vaccines. Particles exhibit a remarkable ability to modulate sophisticated immunity because of their intrinsic adjuvanticity or codelivery with immunostimulatory molecules. Recently, particles have been broadly investigated as carriers for vaccine delivery. Their physicochemical parameters (e.g., size, shape, and surface chemistry) significantly influence their in vivo fate and subsequent immunization effect. Herein, we highlight several types of particulate carrier used in the delivery of vaccines. We also examine how to engineer the physical and chemical characteristics of particulate adjuvants to make them robust candidates for a versatile vaccine delivery platform.

关键词： Lignocellulosic biomass   Combined pretreatment   Fiber degradation   Sugar yield  

摘要： Sustainable biorefinery concepts based on lignocellulosic biomass are gaining worldwide research interest because of their inexpensiveness and abundance. The recalcitrance of lignocellulosic biomass poses a major hindrance to enhance biofuel production. Therefore, a pretreatment step is critical to prepare the substrates for the downstream process. Combining pretreatment steps help to lower the severity of the drawbacks of a single pretreatment step. This paper systematically reviews the combined biological and chemical/physicochemical pretreatment based on fiber degradation and sugar yield. An energy-efficient biological pretreatment method combined with a chemical pretreatment that accelerates the pretreatment times has been seen to be efficient for fiber degradation and sugar yields. However, fungal species, culture conditions, biomass type, the severity of chemical pretreatment and the order of sequential pretreatment influences the relative component contents and sugar yield. Even the same biomass from different sources undergoing similar pretreatment conditions could result in a varying amount of digestibility.

关键词： Nile blue   Polyvinyl alcohol   Irradiation   Chain scission   Crosslinking   gamma-ray protective materials  

摘要： Nile blue (NB, (C20H20ClN3O)) dye/polyvinyl alcohol (PVA) polymer composite films were developed by solvent casting technique, and were further exposed to high energy gamma-ray (25-125 kGy) radiation. The influence of dye content and gamma-ray radiation on the optical-spectral behaviour, structural, thermal and mechanical properties of the PVA-NB composite films was discussed. Modifications of the chemical structure of the host matrix - PVA polymer upon dye intercalation and subsequent radiation exposure on these composite structures was confirmed by FTIR analysis. The UV-Vis studies showed a decrease in both band gap (Eg) and Urbach energies (Eu) on the increase of dye concentration while the band gap decreased and the Urbach energy was found to increase on gamma-irradiation (25-125) kGy. These variations could be due to an increase of crystallinity on dye content loading and contrarily to an increase of amorphous nature upon radiation exposure which is supported by XRD results. Further, the thermal behaviour of the pre and post irradiated composite films were studied using DSC. Consequently, these observed modifications in the physico-chemical properties of the pre and post gamma irradiated PVA-(C20H20ClN3O) polymer composite structures impact the mechanical properties. The mechanical studies have revealed an increase in tensile strength and Young's modulus parameters (maximum of 94.688 MPa and 2185.7 MPa for 1 wt%) upon dye content inclusion. However, these parameters decreased (46.396 MPa and 357.76 MPa for 125 kGy) upon radiation-matter interaction. Interestingly, these films could withstand a gamma radiation upto 75 kGy. Therefore, clearly, these observations suggest that the developed polymer composite films are better candidates for the gamma-ray protective kits such as gloves, layers/shields in a variety of industries.

关键词： Artificial neural network   Ecology   Freshwater biodiversity   Modelling   Mollusc community   Tropical river systems  

摘要： The poor understanding of changes in mollusc ecology along rivers, especially in West Africa, hampers the implementation of management measures. We used a self?organizing map, indicator species analysis, linear discriminant analysis and a random forest model to distinguish mollusc assemblages, to determine the ecological preferences of individual mollusc species and to associate major physicochemical variables with mollusc assemblages and occurrences in the So? River Basin, Benin. We identified four mollusc assemblages along an upstream?downstream gradient. Dissolved oxygen (DO), biochemical oxygen demand (BOD), salinity, calcium (Ca), total nitrogen (TN), copper (Cu), lead (Pb), nickel (Ni), cadmium (Cd) and mercury (Hg) were the major physicochemical variables responsible for structuring these mollusc assemblages. However, the physicochemical factors responsible for shaping the distribution of individual species varied per species. Upstream sites (assemblage I) showed high DO and low BOD and mineral compounds (i.e., TN, salinity, and Ca), which are primarily responsible for structuring the occurrences of bivalves (Afropisidium pirothi, Etheria elliptica, Sphaerium hartmanni) and the gastropod Lanistes varicus. Sites along the middle reach (assemblage II) were characterised by a high degree of organic pollution but low heavy metal pollution;we detected no specific mollusc indicator species. Downstream sites (assemblage III) displayed high mineral and heavy metal concentrations and a fauna without specific indicator species. Finally, downstream sites associated with brackish water (assemblage IV) displayed important levels of organic and heavy metal pollution. These sites are dominated by diverse gastropods (i.e., Bulinus spp., Gabbiella africana, Indoplanorbis exustus, Pachymelania fusca, Radix natalensis, Stenophysa marmorata and Tympanotonos fuscatus). Our results highlight that mollusc communities in the So? River Basin are structured by key physicochemical vari

关键词： Hydrothermal synthesis   Manganese tungstate   Physicochemical properties   Photo-electrochemical performance   Semiconductor   Electronic band structure  

摘要： Manganese tungstate (MnWO4) synthesized by hydrothermal method is characterized by many physicochemical techniques. X-ray diffraction pattern (XRD) confirms the formation of the single-phase MnWO4 crystallizing in a monoclinic system. Scanning electron microscopy (SEM) shows a homogeneous grain distribution of the powder. The optical measurements indicate the existence of one direct optical transition and two indirect ones with an Urbach energy tail of 276.82 meV. The textural study, analyzed by the using the Brunauer, Emmett, and Teller (BET), model gives a specific surface area of 23 m(2) g(-1). The electrical conductivity follows an exponential law, characteristic of a non-degenerate semiconducting with an activation energy of 70 meV. The photo-electrochemical properties of MnWO4 are investigated by using the cyclic voltammetry, chrono-amperometry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS). The results indicate n-type conduction with a flat band potential of -0.41 V-SCE. All these results allowed us to construct the electronic energy diagram of the semiconductor/electrolyte junction in the electrochemical scale.

关键词： Optical and Electronic Materials   Characterization and Evaluation of Materials  

摘要： The present study aims to synthesize the tin oxide (SnO2) nanoparticles (NPs) via the green synthesis route, using Canna indica leaves extract as the reducing agent and examining their properties through various instrumentational techniques. The SnO2 NPs are being synthesized at various temperatures in the range of 400-700 degrees C by the green route method and their effects on the structural, morphological, optical, and magnetic properties have been investigated. On testing, the powder X-ray diffraction (PXRD) studies confirmed the cassiterite-type tetragonal phase of the formed SnO2 NPs with average crystallite size in the range of 10.08-10.87 nm. The FTIR spectrum has recorded for the prepared SnO2 nanostructures to confirm the presence of various functional and vibrational groups. The optical properties of these nanostructures are analysed by UV-Vis absorption studies. The UV-Visible spectrum shows high-intensity absorption peaks in the wavelength region of 280 to 300 nm due to the occurrence of quantum effect, and the bandgap values were found to be decreased with the increase in synthesizing temperature. Similarly, the morphological investigations revealed by scanning electron microscopy (SEM) indicate the formation of various morphologies of SnO2 nanostructures, i.e., platelet-like morphology (400 degrees C) and nanocube (600 degrees C). The transmission electron microscopy (TEM) images specified an average particle size varying in the range of 8.5 to 13.5 nm. The observation of photoluminescent emission at 370 nm for the SnO2 NPs attributes to the defectiveness created by the oxygen vacancies. Finally, the magnetic properties studied using the vibrating sample magnetometer (VSM) at room temperature show the magnetic moment of 3.1052 x 10(-4) emu/g for the highly calcined sample.

关键词： Pea protein   Chickpea protein   Pigeon pea protein   Lentil protein   Functional and molecular features  

摘要： The demand for more functional plant-based proteins has greatly increased. The objective of this study was to provide a systematic understanding of the functional properties and physicochemical features of protein isolates extracted from common pulses. Chickpea protein (ChPI) was much less soluble compared to other extracted proteins. Pigeon pea protein (PiPI) and lab extracted soybean protein (SPI) possessed excellent emulsification capacity and stability of 0.71-0.73 and 0.70-0.71 cm/cm, respectively. Most proteins had foaming capacities greater than 1.20 mL/mL, except for ChPI. Lentil protein (LPI-W), pea protein, and PiPI showed greater water absorption capacity of 4.9, 3.5, and 3.6 g/g than other proteins and good oil absorption capacity. Pigeon pea protein had the greatest gelation capacity, with a least gelation concentration of 80 g/L. ChPI had a higher thermal denaturation peak temperature (169 degrees C) than the other proteins (145-154 degrees C). Commercial SPI was much less functional compared to the lab extracted SPI, which was due to intensive protein denaturation during commercial processing. The amino acid profiles, SDS-PAGE patterns, secondary structure composition, and relative surface hydrophobicity were analyzed to help elucidate the functional features. This study provides useful information in selecting appropriate protein sources to achieve more desirable functional applications.

关键词： cross linking   film formation   Litchi kernel starch   pasting  

摘要： In this study, starch from a non-conventional source, that is, litchi is extracted and cross-linked (CL) with varying concentrations (1%, 3%, and 5%) of sodium trimetaphosphate (STMP). The starches are characterized for their physicochemical, pasting, rheological, and thermal properties. Bio-films are also prepared from these starches and analyzed for selected barrier and mechanical properties. The results indicate that an increase in cross linking agent concentration resulted in a significant decrease in amylose content, swelling power (SP), and solubility of starches. Peak viscosity (PV) and breakdown viscosity (BV) of CL starches are lower in comparison to native starch. Steady shear properties reveal that magnitudes of yield stress (sigma o) and consistency index (K) decrease upon increase in the concentration of cross linking reagent. CL starches exhibit significantly (p < 0.05) higher transition temperatures than native starch. Native starch film shows water solubility of 43.66% while for films from CL starches, the values ranged between 35.12 and 41.53%. Significant (p < 0.05) reduction in water vapor permeability (WVP) values of CL starch films (1.24-1.52 g m Pa-1 s(-1) m(-2)) is observed in comparison to native (2.32 g m Pa-1 s(-1) m(-2)) starch films. Cross linking significantly improves tensile strength (TS) of films, however, films elongation is lower (14.71-17.97%) than native starch film (19.88%).