Cooperative effects in surfactant adsorption layers at water/alkane interfaces

In the present work, the properties of dodecyl dimethyl phosphine oxide (C12DMPO) at the water/decane interface are studied and compared with those obtained earlier at the interface to hexane. To simulate the interfacial behavior, a two-component thermodynamic model is proposed, which combines the equation of state and Frumkin isotherm for decane with the reorientation model involving the intrinsic compressibility for the surfactant. In this approach, the surface activity of decane is governed by its interaction with C12DMPO. The theory predicts the influence of decane on the decrease of the surface tension at a very low surfactant concentration for realistic values of the ratio of the adsorbed amounts of decane and surfactant. The surfactantrsquo;s distribution coefficient between the aqueous and decane phases is determined. Two types of adsorption systems were used: a decane drop immersed into the C12DMPO aqueous solution, and a water drop immersed into the C12DMPO solution in decane. To determine the distribution coefficient, a method based on the analysis of the transfer of C12DMPO between water and decane is also employed

Reaction of 2-phenyl(acetyl)-5-methyldiazaphosphole with phenyl azide

The reaction of 2-phenyl(acetyl)-5-methyldiazaphospholes with phenyl azide results in the formation of trimers which form 2-phenyl(acetyl)-3-oxo-3-anilino-5-methyl-1,2,3-diazaphospholines during hydrolysis. © 1982 Plenum Publishing Corporation

Reaction of 2-phenyl (acetyl)-5-methyldiazaphosphole with diazomethane and diazofluorene

1. 2-Phenyl-5-methyldiazaphosphole reacts with diazomethane with the evolution of nitrogen and the formation of a trimeric adduct of 1:1 composition. 2. The reaction of 2-acetyl-5-methyldiazaphosphole with 9-diazofluorene in pentane gives an adduct of pyrazoline structure which easily releases N2 with the formation of a trimer, obtained directly in carrying out the reaction without a solvent and in CCl4, CH2C12, or C6H6. 3. In the reaction of 9-diazofluorene with 2-phenyl-5-methyldiazaphosphole, either a trimeric adduct of 1:1 composition or its mixtrue with the corresponding pyrazoline derivatives is formed, depending on the nature of the solvent and the temperature. © 1981 Plenum Publishing Corporation

Non-Radioactive TRF Assay Modifications to Improve Telomeric DNA Detection Efficiency in Plants

© 2016, Springer Science+Business Media New York.The length of telomeric DNA is often considered a cellular biomarker of aging and general health status. Several telomere length measuring assays have been developed, of which the most common is the telomere restriction fragment (TRF) analysis, which typically involves the use of radioactively labeled oligonucleotide probes. While highly effective, this method potentially poses substantial health concerns and generates radioactive waste. Digoxigenin (DIG) alternatives to radioactive probes have been developed and used successfully in a number of assays. Here, we optimize the DIG protocol to measure telomere length in the model plant Arabidopsis thaliana and present evidence that this approach can be used successfully to efficiently and accurately measure telomere length in plants. Specifically, hybridization temperature of 42 °C instead of the typical 55 °C appears to generate stronger signals. In addition, DIG incorporation at 5′-end instead of 3′-end of the labeled oligonucleotide greatly enhances signal. We conclude that non-radioactive TRF assays can be as efficient as radioactive methods in detecting and measuring telomere length in plants, making this assay suitable for medical and research laboratories unable to utilize radioactivity due to hazardous waste disposal and safety concerns

Herpesvirus infection and infectious mononucleosis

In this review we present current information on various aspects of infectious mononucleosis in children. Based on the analysis of scientific literature highlights the major etiological factors that lead to the development of this disease. The paper describes the clinical and laboratory features of infectious mononucleosis caused by Epstein-Barr virus, cytomegalovirus, human herpes virus type VI. Presents literature data on the impact of herpes infection on the development of mononucleosis. Showing modern aspects of an integrated diagnosis of herpesvirus infection in infectious mononucleosis in children

Drug Loaded Biodegradable Load-Bearing Nanocomposites for Damaged Bone Repair

In this paper we present a short review-scientific report on processing and properties, including in vitro degradation, of load bearing biodegradable nanocomposites as well as of macroporous 3D scaffolds for bone ingrowth. Biodegradable implantable devices should slowly degrade over time and disappear with ingrown of natural bone replacing the synthetic graft. Compared to low strength biodegradable polymers, and brittle CaP ceramics, biodegradable CaP-polymer and CaP-metal nanocomposites, mimicking structure of natural bone, as well as strong and ductile metal nanocomposites can provide to implantable devices both strengths and toughness. Nanostructuring of biodegradable [beta]- TCP (tricalcium phosphate)-polymer (PCL and PLA), [beta]-TCP-metal (FeMg and FeAg) and of Fe-Ag composites was achieved employing high energy attrition milling of powder blends. Nanocomposite powders were consolidated to densities close to theoretical by high pressure consolidation at ambient temperature-cold sintering, with retention of nanoscale structure. The strength of developed nanocomposites was significantly higher as compared with microscale composites of the same or similar composition. Heat treatment at moderate temperatures in hydrogen flow resulted in retention of nanoscale structure and higher ductility. Degradation of developed biodegradable [beta]-TCP-polymer, [beta]-TCPmetal and of Fe-Ag nanocomposites was studied in physiological solutions. Immersion tests in Ringer's and saline solution for 4 weeks resulted in 4 to 10% weight loss and less than 50% decrease in compression or bending strength, the remaining strength being significantly higher than the values reported for other biodegradable materials. Nanostructuring of Fe-Ag based materials resulted also in an increase of degradation rate because of creation on galvanic Fe-Ag nanocouples. In cell culture experiments, the developed nanocomposites supported the attachment the human osteoblast cells and exhibited no signs of cytotoxicity. Interconnected system of nanopores formed during processing of nanocomposites was used for incorporation of drugs, including antibiotics and anticancer drugs, and can be used for loading of bioactive molecules enhancing bone ingrowth

Phytocoenotic Distribution of Hulthemia persica (Michaut ex Juss.) Bornm. (Rosaceae) under Different Ecological Conditions in Uzbekistan

The paper presents some of the results of the 2020–2022 studies of 7 communities with the participation of a poorly studied forage and melliferous species, Hulthemia persica, in the Republic of Uzbekistan. The research goal is to identify the phytocenotic confinement of the poorly studied forage and melliferous species H. persica in various environmental conditions in the Republic of Uzbekistan. Phytocoenotic studies in 7 communities have shown that the population numbers of H. persica in the Tashkent Region (Parkentsay) are satisfactory. However, in recent years the strong impact of anthropogenic factors, primarily livestock grazing under natural growing conditions, has affected this species’ abundance, which has gradually disappeared. Large-scale exploration and prospecting, with the development of the oil and gas industry and other technogenic factors, has harmed the state of H. persica; therefore, populations lack young individuals and the cover provided by this species is relatively low. Therefore, it is crucial to strengthen protection measures, which the authors also recommend using for degraded pastures in the desert and foothill regions of the Republic of Uzbekistan. A detailed survey of natural populations and monitoring their condition should be carried out. In particular, H. persica is a promising plant adapted to various environmental conditions and can be used in degraded pastures in desert and foothill regions of the Republic of Uzbekistan

Histidine Acid Phytases of Microbial Origin

© 2018, Pleiades Publishing, Ltd. Abstract—: This review is focused on analysis of the biological diversity of phytase-producing microorganisms capable of degrading phytate to inorganic phosphate. General approaches to microbial phytase classification are discussed, with a particular emphasis on histidine acid phytases (HAPs), which catalyze specific cleaving of myo-inositol hexakisphosphate. The effect of glycosylation and various effectors on enzyme thermostability and activity of phytases are described. The data on the biosynthesis of histidine acid phytases, their substrate specificity, and on the mechanism of myo-inositol hexakisphosphate hydrolysis are considered. A conclusion is made concerning the biotechnological potential of this group of microbial enzymes

An improved gene expression system to generate transgenic arabidopsis thaliana plants harboring a Bacillus ginsengihumi phytase gene

We constructed a new vector system for heterologous gene expression in Arabidopsis thaliana. The construct contains a codon-optimized sequence encoding Bacillus ginsengihumi phytase behind an inducible plant-specific promoter for expression in root epithelial cells. The new vector introduced into the plant A. thaliana by Agrobacterium mediated transformation. We obtained several generations of transgenic A. thaliana plants with integrated Bacillus ginsengihumi phytase gene, as well as with an empty vector as a negative control. We tested several transgenic plants harboring the phyCg construct under the control of phosphate-starvation inducible Pht1;2 promoter and show that the phyCg gene is expressed at the mRNA level. Further characterization of these lines of plants will help us to design an improved transgenic strategy for the development of a root-specific heterologous system for the expression of bacterial phytases in plants