Interferometric evaluation of collagen concentration in tendon fibers

The dry mass concentration of collagen in native rat tail tendon fibers was studied by interferometric techniques. It could be shown that the collagen concentration of rat tail tendon fibers is not constant nor does it vary uniformly with the fiber diameter. Evidence is presented that the collagen concentration shows significant oscillations as a function of diameter. In order to explain the experimental findings, a layered model is proposed for the fiber structure; age dependent changes were also studied. It seems that the fiber structure is unaltered by ageing at the supramolecular level but its functional capacities are affected and swelling is inhibited.

The Malachite Green Biodegradation in Bioreactors on Various pH Domains

In the experimental study was studied the malachite green colorant biodegradation in biological sludge with biological activity. The biodegradability tests were carried out in laboratory bioreactors, on aqueous solutions of green malachite contacted with microorganisms in which the dominant species is Paramecium caudatum, in a pH range between 8 and 12, temperatures in the ranges 25-350C, using pH neutralizing substances and biomass growth promoters. The colorant initial concentrations and those obtained after biological degradation depending on the contact time, at certain pH values, were established through UV-Vis spectrometry. The studies have shown the measure of possible biological degradation of some organic substances with extended uses, with largely aromatic structure, resistance to biodegradation of microorganisms, commonly used in wastewater treatment plants.

Removal of Dyes from Textile Wastewater Using Sawdust as Low-cost Biosorbent

Dyes removal from textile effluents has been a matter of concern, both in health point of view and in the aesthetic sense. A waste material, characterized by ligno cellulose composition, availability and low cost was tested for its ability to remove synthetic dyes from aqueous systems. This study presents the results of the adsorption process of Alizarin Red S (AR) on some adsorbents: white pine sawdust (Pinus durangensis) and beech wood sawdust (Fagus sylvatica). The suitability of the Langmuir, Freundlich and Harkins - Jura adsorption models to the equilibrium data were investigated for each reactive dye - adsorbent system, in order to establish all favourable conditions to uptake of AR reactive dye from aqueous solution. The results of this study indicate that waste of wood is an attractive sorbent for removing synthetic dyes from the wastewater.

Ecotoxicity of o-Chlorobenzylidene Malononitrile (CBM) and Toxicological Risk Assessment for SCLP Biological Cultures (Saccharomyces sp., Chlorella sp., Lactobacillus sp., Paramecium sp.)

Toxic substances used as chemical weapons present a number of particularities that affect the surrounding environment, having a wide range of action by disrupting the ecological balance: they may infect soil or air, or form aerosols through smoke or toxic fog. Such substances can have a long duration of action, from minutes to weeks, which is why they are used in military attacks. This study evaluated the toxicological character of o-chlorobenzyliden malonitrile (CBM) in order to study the toxicity limit of this substance using microbiological cultures of Saccharomyces sp., Chlorella sp., Lactobacillus sp. and Paramecium sp., which were used to determine their rate of growth in the presence of different concentrations of o-chlorobenzyliden malonitrile and their ability to respond to this toxic stimulus.

Reduction of Oxygen Production by Algal Cells in the Presence of O-Chlorobenzylidene Malononitrile

Chemical compounds, such as the CS gas employed in military operations, have a number of characteristics that impact the ecosystem by upsetting its natural balance. In this work, the toxicity limit and microorganism's reaction to the oxidative stress induced by O-chlorobenzylidenemalonitrile, a chemical found in CS gas, were assessed in relation to the green algae Chlorella pyrenoidosa. A number of parameters, including the cell growth curve, the percent inhibition in yield, the dry cell weight, the percentage viability and productivity of algal biomass flocculation activity, and the change in oxygen production, were analyzed in order to comprehend the toxicological mechanisms of O-chlorobenzylidenemalonitrile on algal culture. Using fluorescence and Fourier transform infrared spectroscopy (FTIR), the content of chlorophyll pigments was determined. The values obtained for pH during the adaptation period of the C. pyrenoidosa culture were between 6.0 and 6.8, O2 had values between 6.5 and 7.0 mg/L, and the conductivity was 165-210 µS/cm. For the 20 µg/mL O-chlorobenzylidenemalonitrile concentration, the cell viability percentage was over 97.4%, and for the 150 µg/mL O-chlorobenzylidenemalonitrile concentration was 74%. The ECb50 value for C. pyrenoidosa was determined from the slope of the calibration curve; it was estimated by extrapolation to the value of 298.24 µg/mL. With the help of this study, basic information on the toxicity of O-chlorobenzylidenemalonitrile to aquatic creatures will be available, which will serve as a foundation for evaluating the possible effects on aquatic ecosystems. The management of the decontamination of the impacted areas could take the results into consideration.

Hydration forces involved in cellular interactions

Cellular physical interactions are determinant in many and various biological processes: aggregation, adhesion, segregation, contact inhibition, fusion, etc. A real advance concerning the understanding of cellular interactions from a physical point of view has been performed of late, but a great many problems still remain to be clarified. Thus, DLVO theory extrapolated to cell-cell interactions, is unable to describe cellular interactions at very short distances of separation, where other forces play an important role. A sketch of the original form of DLVO theory, its criticism along with the nature and mechanism of the short range repulsive forces (hydration forces) are presented and discussed.

The Contamination Effects and Toxicological Characterization of o-Chlorobenzylidene Manolonitrile

Toxicological characterization and global assessment of the toxicity of some chemicals used in the specific technique of the defense and public order system (e.g. o-chlorobenzylidene manolonitrile which enters the composition of the CS gas) is especially useful for environmental protection. Based on the results obtained, the toxicological characterization (acute lethal toxicity) and the harmful potential of some toxic substances, individual or in mixture, against euythermal sweet fish are established. The tests performed aim to change the behavior of the species studied in the presence of chlorobenzylidene manolonitrile, a substance used in the technique of defense and public order system. The tests established the toxicity values of acute lethal concentration LC50 and serve to further determine the maximum allowable concentration that inhibits the development of normal fish fauna in contaminated waters. The test results allow the toxicological characterization and measurement of the acute lethal toxicity of an inhibitor, in order to make more efficient its elimination from the contaminated environment.

Synthesis, Purity Check, Hydrolysis and Removal of o-Chlorobenzyliden Malononitrile (CBM) by Biological Selective Media

The removal yield of organic substances present in water depends on the environmental conditions, on the chemical composition of the water and on the chemical substance dissolved in the water, which constitutes the substrate of the metabolic activities of the microalgae that use these substances in the biochemical reactions of cellular enzyme complexes. o-Chlorobenzylidene malononitrile (CS, to use its military designation) was synthesized in-house, for research purposes, by a condensing reaction between o-chlorobenzaldehide and malononitrilein the presence of diethylamine. The detection, identification and confirmation of o-chlorobenzylidenemalononitrile (coded CBM in this experimental study) was performed using gas chromatography-mass spectrometry (GC-MS) and the purity of CBM was 99%. The biodegradation capacity in the samples that contained the biological suspension, after 24 h and 96 h of incubation, was determined via GC-MS analysis, and no evidence of the presence of CBM or some metabolites of CBM was detected. In the parallel samples, a hydrolysis process of CBM at room temperature, without biological treatment, revealed two main metabolites, malononitrile and o-chlorobenzaldehyde, respectively. This study is focused on evaluating the biodegradation capacity of o-chlorobenzylidene malononitrile in the presence of a biological material, culture of Chlorella sp., in comparison with a classical hydrolysis process. The tests performed indicate that the suspension of Chlorella sp. consumed the entire amount of CBM and metabolites from the analyzed samples. The tests prove that the biological material can be used to decontaminate the affected areas.

Evaluation of nutrient value and a classification of food products of animal origin in accordance with reconsidered water/protein ratio

Water/protein ratio, criterion of evaluation of comparative nutrive value of meat products, fully used at present in some European countries, does not take into account the nutritive value of protein from the structure. This work presents a reconsideration of the evaluation of food proteinogenic value, on the basis of numerous analytical data from collagen dosing and setting of collagen/protein ratio as well as from biological tests on laboratory animals, thus correcting the amount of total protein and, implicitly, water/protein ratio. Tables of these products structure and classification in accordance with water/protein ratio are given.