Modulation of cellulose nanocrystals amphiphilic properties to stabilize oil/water interface

Neutral cellulose nanocrystals dispersed in water were shown in a previous work to stabilize oil/water interfaces and produce Pickering emulsions with outstanding stability, whereas sulfated nanocrystals obtained from cotton did not show interfacial properties. To develop a better understanding of the stabilization mechanism, amphiphilic properties of the nanocrystals were modulated by tuning the surface charge density to investigate emulsifying capability on two sources of cellulose: cotton linters (CCN) and bacterial cellulose (BCN). This charge adjustment made it possible to determine the conditions where a low surface charge density, below 0.03 e/nm(2), remains compatible with emulsification, as well as when assisted by charge screening regardless of the source. This study discusses this ability to stabilize oil-in-water emulsions for cellulose nanocrystals varying in crystalline allomorph, morphology, and hydrolysis processes related to the amphiphilic character of nonhydrophobized cellulose nanocrystal.     

Influence of Environmental Factors on the Structure of Soil Microfungi of Vietnamese Tropical Forests

Results of a multiyear complex study of species diversity, features and patterns of distribution, substrate colonization, and ecology of soil microscopic fungi in the lowland, piedmont, and mountain monsoon rain forests of Vietnam are presented for the first time. In 97 forest habitats studied within 13 specially protected areas of Vietnam in the Northern, Central, and Southern parts of the country, 510 species of micromycetes from 148 genera have been identified. The influence of environmental factors (climatic features, relief, soils, forest types, etc.) on the formation of complexes of micromycetes has been analyzed. As a result, the dependence of the number of colony-forming units (CFUs) on the type of the substrate and the season (wet/dry) is established: significantly more species are detected in the dry season (October–March) (p < 0.05) in comparison with the wet one; many species are associated with certain plant species. Indicators of species diversity decrease with an increase above sea level altitude (p < 0.01). Herewith, the ratio of the taxonomic groups of micromycetes also consistently changes. A latitudinal–zonal trend of the change of the species composition of microscopic fungi, determined by a combination of environmental factors, has been revealed.     

Fusicoccin-Like Ligands in Higher Plants

Fusicoccin-like ligands in higher plants were sought by combining high performance liquid chromatography with radioreceptor analysis and radioimmunoassay. Such substances were found in genetically transformed cultured roots of horseradish, alteus and lupine as well as in native horseradish, cucumber, horse chestnut, and maize plants. In root crops such as carrot and sugar beet or in potato tubers, only traces of fusicoccin-like ligands were detected. Fusicoccin A was detected in genetically transformed cultured roots of horseradish by gas chromatography/mass spectrometry. Received October 15, 1996; accepted February 14, 1997     

The effect of infrared laser irradiation on the growth of human melanoma cells in culture

Biophysics - Low-intensity laser irradiation exerts effects on various biological objects and is currently exploited in various branches of medicine. From a practical point of view, irradiation in...     

Histological and immunohistochemical effects of Curcuma longa on activation of rat hepatic stellate cells after cadmium induced hepatotoxicity

The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats.     

Inhibition of interferon secretion by vinblastine

The plant alkaloids vinblastine and colchicine are known to arrest cells in mitosis by virtue of their binding to spindle protein. These drugs are also capable of binding to microtubule protein and causing these structures to disaggregate into nonfunctional subunits (1, 2). Microtubular structures are thought to be involved in the secretory process of a number of proteins including insulin (7), collagen (4), and thyroid hormone (12). In this report we present our findings on the effects of these two drugs on the synthesis and secretion of interferon in a high producing human foreskin fibroblast strain (FS-4) (11).     

A comparative study of the sensitivity and specific activity of an immunoenzyme test system for determining class-M antibodies to the hepatitis A virus

The diagnostic value of the first experimental production batches of assay kit "DIAGN-A-HEP", produced at the Institute of Poliomyelitis and Viral Encephalitides (USSR Acad. Med. Sci.) and intended for the determination of IgM to hepatitis A virus (HAV) in the enzyme immunoassay (EIA), has been studied in comparison with that of the internationally known and widely approved commercial EIA system "HAVAB-MEIA" for the determination of antibodies to HAV (the product of Abbott, USA). The study has revealed that the EIA kit "DIAGN-A-HEP" is highly sensitive and specific, and the diagnostic value of this kit is not inferior to that of the commercial assay system "HAVAB-MEIA". On the basis of this study the use of the EIA kits "DIAGN-A-HEP" in medical practice has been allowed by the decree of the Ministry of Health of the USSR.