Evaluation of cytotoxicity,biophysics and biomechanics of cells treated with functionalized hybrid nanomaterials

Hybrids consisting of carboxylated, single-walled carbon nanotube (c-SWNT)–silver nanoparticles (AgNPs)-DNA–poly vinyl alcohol (PVA) are synthesized via sequential functionalization to mimic the theragnostic (therapy and diagnosis) system. Carboxylation of SWNT has minimized the metal impurities with plenty of –COOH groups to produce hybrid (c-SWNT-AgNPs). The hybrid is further wrapped with DNA (hybrid-DNA) and encapsulated with PVA as hybrid composite (HC). Materials were tested against human alveolar epithelial cells (A549), mouse fibroblasts cells (NIH3T3) and human bone marrow stromal cells (HS-5). The composition-sensitive physico-chemical interactions, biophysics and biomechanics of materials-treated cells are evaluated. The cell viability was improved for HC, hybrid-PVA and c-SWNT when compared with SWNT and hybrid. SWNT and hybrid showed cell viability less than 60% at high dose (40 µg ml⁻¹) and hybrid-PVA and HC retained 80% or more cell viability. The treatment of hybrid nanomaterials considerably changed cell morphology and intercellular interaction with respect to the composition of materials. Peculiarly, PVA-coated hybrid was found to minimize the growth of invadopodia of A549 cells, which is responsible for the proliferation of cancer cells. Surface roughness of cells increased after treatment with hybrid, where cytoplasmic regions specifically showed higher roughness. Nanoindentation results suggest that changes in biomechanics occurred owing to possible internalization of the hybrid. The changes in force spectra of treated cells indicated a possible greater interaction between the cells and hybrid with distinct stiffness and demonstrated the surface adherence and internalization of hybrid on or inside the cells.     

Enhanced Anthocyanin Extraction from Red Cabbage Using Pulsed Electric Field Processing

Abstract: This study was conducted to evaluate the effect of pulsed electric field (PEF) treatment on anthocyanin extraction from red cabbage using water as a solvent. Mashed cabbage was placed in a batch treatment chamber and subjected to PEF (2.5 kV/cm electric field strength; 15 μs pulse width and 50 pulses, specific energy 15.63 J/g). Extracted anthocyanin concentrations (16 to 889 μg/mL) were determined using HPLC. Heat and light stabilities of the control and PEF-treated samples, having approximately the same initial concentrations, were studied. PEF treatments enhanced total anthocyanin extraction in water from red cabbage by 2.15 times with a higher proportion of nonacylated forms than the control (P < 0.05). The heat and light stabilities of the PEF-treated samples and control samples were not significantly different (P > 0.05). Practical Application: An innovative pretreatment technology, pulsed electric field processing, enhanced total anthocyanin extraction in water from red cabbage by 2.15 times. Manufacturers of natural colors can use this technology to extract anthocyanins from red cabbage efficiently.     

Probabilistic and Other Neural Nets in Multi-Hole Probe Calibration and Flow Angularity Pattern Recognition

The use of probabilistic (PNN) and multilayer feedforward (MLFNN) neural networks is investigated for the calibration of multi-hole pressure probes and the prediction of associated flow angularity patterns in test flow fields. Both types of network are studied in detail for their calibration and prediction characteristics. The current formalism can be applied to any multi-hole probe, however the test results for the most commonly used five-hole Cone and Prism probe types alone are reported in this paper. Received: 1 October 1998?Received in revised form: 12 December 1998?Accepted: 16 December 1998     

Glycerol Esters from Real Waste Cooking Oil Using a Robust Solid Acid Catalyst

Notwithstanding the food-for-fuel debate, turning waste cooking oil and fat (WCO) into a valuable product is a classic example of green chemistry. We demonstrate that sulfated zirconia and lanthanum-supported sulfated zirconia are good catalysts for the esterification of WCO free fatty acids (FFAs) with glycerol, giving high-value monoglycerides. Various catalysts were first screened using palmitic acid as a model FFA. Subsequently, six 10-kg batches of actual WCO were collected from commercial cookeries over a period of 28 weeks, pre-treated in a purpose-built decanter and esterified with industrial grade glycerol using heterogeneous catalysis. Good yield and turnovers were obtained. The pre-treatment stage and the catalytic esterification experiments are described and discussed.     

An Overview on the Synthetic Routes and Properties of Ammonium Dinitramide (ADN) and other Dinitramide Salts

In recent years, there has been a considerable interest in the development of novel type of high performance propellants for use in solid rocket motors. Ammonium salt of dinitramidic acid NH₄N(NO₂)₂ (ADN) has attracted wide interest as a potentially useful energetic oxidizer for rocket propellants because of its clean and environment‐friendly exhaust products during burning. ADN contains one N (NO₂)₂ group and its synthesis requires new type of N‐nitration. The present paper reviews the general synthetic methods used for the synthesis of inorganic, organic and metal dinitramide salts and their properties, with a special emphasis on ammonium dinitramide. The salient features with reference to the extent of conversion and ease of separation of the products of the various synthetic methodologies are also addressed.     

Performance and emission study on the effect of oxygenated additive in neat biodiesel fueled diesel engine

This work presents the effect of the Di-tetra-butyl-peroxide (DTBP) as an oxygenated additive on neat used mustard oil biodiesel (B100) to evaluate the emission and performance engine characteristics. Four fuels, namely, diesel, biodiesel (Mustard biodiesel), a blend of B100-10percentage, and 20% by volume of DTBP (BD90DTBP10 and BD80DTBP20) are prepared and tested on a single cylinder, constant speed diesel engine. Experimental outcomes revealed that 20% of DTBP reduces 7.3% CO, 5.1% HC, and 4.6% NOx and 3.2% smoke emissions of B100. From this study, further, it is inferred that BD80DTBP20 blend could be utilized as an alternative fuel for a CI engine with no modifications in engine design.     

Glycerol Esters from Real Waste Cooking Oil Using a Robust Solid Acid Catalyst

Notwithstanding the food-for-fuel debate, turning waste cooking oil and fat (WCO) into a valuable product is a classic example of green chemistry. We demonstrate that sulfated zirconia and lanthanum-supported sulfated zirconia are good catalysts for the esterification of WCO free fatty acids (FFAs) with glycerol, giving high-value monoglycerides. Various catalysts were first screened using palmitic acid as a model FFA. Subsequently, six 10-kg batches of actual WCO were collected from commercial cookeries over a period of 28 weeks, pre-treated in a purpose-built decanter and esterified with industrial grade glycerol using heterogeneous catalysis. Good yield and turnovers were obtained. The pre-treatment stage and the catalytic esterification experiments are described and discussed.

     

Homogeneous Nature of Malaysian Marine Fish Epinephelus fuscoguttatus (Perciformes; Serranidae): Evidence Based on Molecular Markers,Morphology and Fourier Transform Infrared Analysis

Taxonomic confusion exists within the genus Epinephelus due to the lack of morphological specializations and the overwhelming number of species reported in several studies. The homogenous nature of the morphology has created confusion in the Malaysian Marine fish species Epinephelus fuscoguttatus and Epinephelus hexagonatus. In this study, the partial DNA sequence of the 16S gene and mitochondrial nucleotide sequences of two gene regions, Cytochrome Oxidase Subunit I and III were used to investigate the phylogenetic relationship between them. In the phylogenetic trees, E. fuscoguttatus was monophyletic with E. hexagonatus species and morphology examination shows that no significant differences were found in the morphometric features between these two taxa. This suggests that E. fuscoguttatus is not distinguishable from E. hexagonatus species, and that E. fuscoguttatus have been identified to be E. hexagonatus species is likely attributed to differences in environment and ability to camouflage themselves under certain conditions. Interestingly, this finding was also supported by Principal Component Analysis on Attenuated Total Reflectance–Fourier-transform Infrared (ATR-FTIR) data analysis. Molecular, morphological and meristic characteristics were combined with ATR-FTIR analysis used in this study offer new perspectives in fish species identification. To our knowledge, this is the first report of an extensive genetic population study of E. fuscoguttatus in Malaysia and this understanding will play an important role in informing genetic stock-specific strategies for the management and conservation of this highly valued fish.     

Validation of process technologies for enhancing the safety of low-moisture foods: A review

The outbreaks linked to foodborne illnesses in low-moisture foods are frequently reported due to the occurrence of pathogenic microorganisms such as Salmonella Spp. Bacillus cereus, Clostridium spp., Cronobacter sakazakii, Escherichia coli, and Staphylococcus aureus. The ability of the pathogens to withstand the dry conditions and to develop resistance to heat is regarded as the major concern for the food industry dealing with low-moisture foods. In this regard, the present review is aimed to discuss the importance and the use of novel thermal and nonthermal technologies such as radiofrequency, steam pasteurization, plasma, and gaseous technologies for decontamination of foodborne pathogens in low-moisture foods and their microbial inactivation mechanisms. The review also summarizes the various sources of contamination and the factors influencing the survival and thermal resistance of pathogenic microorganisms in low-moisture foods. The literature survey indicated that the nonthermal techniques such as CO₂, high-pressure processing, and so on, may not offer effective microbial inactivation in low-moisture foods due to their insufficient moisture content. On the other hand, gases can penetrate deep inside the commodities and pores due to their higher diffusion properties and are regarded to have an advantage over thermal and other nonthermal processes. Further research is required to evaluate newer intervention strategies and combination treatments to enhance the microbial inactivation in low-moisture foods without significantly altering their organoleptic and nutritional quality.     

Modeling the effect of temperature on growth of Salmonella in chicken

Growth data of Salmonella in chicken were collected at several isothermal conditions (10, 15, 20, 25, 28, 32, 35, 37, 42, and 45 degrees C) and were then fitted into primary models, namely the logistic model, modified Gompertz model and Baranyi model. Measures of goodness-of-fit such as mean square error, pseudo-R(2), -2 log likelihood, Akaike's information, and Sawa's Bayesian information criteria were used for comparison for these primary models. Based on these criteria, modified Gompertz model described growth data the best, followed by the Baranyi model, and then the logistic model. The maximum growth rates obtained from each primary model were then modeled as a function of temperature using the modified Ratkowsky model. Pseudo-R(2) values for this secondary model describing growth rate obtained from Baranyi, modified Gompertz, and logistic models were 0.999, 0.980, and 0.990, respectively. Mean square error values for corresponding models were 0.0002, 0.0008, and 0.0009, respectively. Both measures clearly show that the Baranyi model performed better than the modified Gompertz model or the logistic model.