Thermal analysis of lipids isolated from various tissues of sheep fats

The physical–chemical properties and fatty acid composition of sheep subcutaneous, tallow, intestinal, and tail fats were determined. Sheep fat types contained C_16:0, C_18:0, and C_18:1 as the major components of fatty acid composition (19.56–23.40, 20.77–29.50, 32.07–38.30%, respectively). Differential scanning calorimetry (DSC) study revealed that two characteristic peaks were detected in both crystallization and melting curves. Major peaks (T _peak) of tallow and intestinal fats were similar and determined as 31.25–24.69 and 7.44–3.90 °C, respectively, for crystallization peaks and 15.36–13.44 and 45.98–44.60 °C, respectively, for melting peaks in DSC curves; but those of tail fat (18.29 and −2.13 °C for crystallization peaks and 6.56 and 33.46 °C for melting peaks) differed remarkably from those of other fat types.     

Physicochemical properties of alkali-treated new cellulosic fiber from cotton shell

The aim of this present investigation was to identify a new natural fiber from one of the cotton plant’s byproducts, which is chemically modified by alkaline treatment. Its characteristics were examined for the preparation of natural fiber–reinforced polymer composites. The cotton shell fibers (CSFs) were extracted from the cotton shell and its degree of crystallinity, crystallite size, chemical constituents group, and thermal stability were determined by X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis. The alkali treatment of CSFs is optimized at 5% (w/v) NaOH aqueous solution with 45 min soaking time.     

The thermal analysis of lipids isolated from various tissues of deers and does

TG analysis of lipids is a suitable analytical method that offers the possibility to correlate kinetic parameters of thermal degradation (activation energy) and lipid composition. For this purpose, an inert (nitrogen) or oxidising atmosphere (oxygen) was applied during the thermal treatment (30–220°C) of lipids isolated from intramuscular and fatty tissues (L-IMT and L-FT) of deers and does. Prior to investigation, the extracted samples of lipids were kept at –24°C or +4°C for nine months, thus enabling detection of the influence of storage temperature on the thermal behaviour of the lipids.     

Thermal properties of fibres from a new polymer of the polyimideamide group

The paper presents the thermal properties of fibres made of a modified polyimideamide. The effects of as-spun draw ratio and deformation during the fibre drawing stage on the structure, thermal properties, moisture absorption and tenacity of the obtained fibres have been determined. Based on the findings obtained by the DTA and DSC methods, it has been found that the modification of the polymer under investigation causes its glass transition temperature to decrease through the increase of molecular mobility. At the same time, the heat-resistant fibres with the amorphous oriented structure are characterized by a tenacity of 16 cN/tex, good absorption properties and increased porosity. The thermal stability indices of the examined fibres have been determined on the basis of thermogravimetric curves obtained both under air and inert gas. This revised version was published online in July 2006 with corrections to the Cover Date.     

Physicochemical properties of new cellulosic fibers from the bark of Acacia arabica

With the growing environmental consciousness toward carbon emissions, natural fibers are the best alternative and act as a substitute for synthetic fibers due to their potential properties. New cellulosic fibers were identified from Acacia arabica bark. This study aimed at understanding the characteristics of Acacia arabica fibers (AAFs) extracted from the bark of the A. arabica, and its physicochemical properties were examined by thermal stability analyses, X-ray diffraction, chemical constitutions, and Fourier transform infrared spectroscopy analysis. Cellulose content (68.1 wt%), density (1028 kg m^?3), and crystallinity index (51.72%) properties were identified.     

Synthesis and properties of polyimides derived from a new diamine containing bulky-flexible pendent group

Novel aromatic polyimides containing bulky-flexible pendent group were successfully synthesized by direct polycondensation of N-(4-(4-(4,5-diphenyl-1H-imidazole-2-yl)phenoxy)phenyl)-3,5-diaminobenzamide with various tetracarboxylic dianhydrides. These polymers are soluble in most of the aprotic organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, dimethylsulfoxide, N,N-dimethylacetamide, hexamethylphosphoramide, m-cresol, and pyridine. The prepared polymers were characterized by viscometry, FT-IR, ¹H NMR, and UV-Vis spectroscopy, fluorimetry, elemental analysis; the thermal properties were evaluated by differential scanning calorimetric and thermogravimetric analysis.     

Physicochemical properties of new cellulosic Artisdita hystrix leaf fiber

The characterization of new natural fiber is increasing due to its excellent properties. This drives investigators to create high performance composites. The present investigation was designed to study the physicochemical properties of fibers obtained from the leaf of the Artistida hystrix. The Artistida hystrix fibers (AHFs) had crystallinity index (44.85%), cellulose (59.54 wt%), hemicellulose (11.35 wt%), lignin (8.42 wt%), and density (540 kg m^?3). The tensile strength of AHFs was 440 ± 13.4 MPa with an average strain rate of 1.57 ± 0.04%. The calculated microfibril angle of AHFs was 12.64 ± 0.45°, which influenced the mechanical properties.     

Physicochemical properties affecting lipofection potency of a new series of 1,2-dialkoylamidopropane-based cationic lipids

The in vitro transfection activity of a novel series of N,N'-diacyl-1,2-diaminopropyl-3-carbamoyl-(aminoethane) derivatives was evaluated against a mouse melanoma cell line at different +/- charge ratios, in the presence and absence of helper lipids. Only the unsaturated derivative N,N'-dioleoyl-1,2-diaminopropyl-3-carbamoyl-(aminoethane), (1,2lmp[5]) mediated significant increase in the reporter gene level which was significantly boosted in the presence of DOPE peaking at +/- charge ratio of 2. The electrostatic interactions between the cationic liposomes and plasmid DNA were investigated by gel electrophoresis, fluorescence spectroscopy, dynamic light scattering and electrophoretic mobility techniques. In agreement with the transfection results, 1,2lmp[5]/DOPE formulation was most efficient in associating with and retarding DNA migration. The improved association between the dioleoyl derivative and DNA was further confirmed by ethidium bromide displacement assay and particle size distribution analysis of the lipoplexes. Differential scanning calorimetry studies showed that 1,2lmp[5] was the only lipid that exhibited a main phase transition below 37 degrees C. Likewise, 1,2lmp[5] was the only lipid found to form all liquid expanded monolayers at 23 degrees C. In conclusion, the current findings suggest that high in vitro transfection activity is mediated by cationic lipids characterized by increased acyl chain fluidity and high interfacial elasticity.     

Physicochemical properties of protease A from cotton seeds

It has been found that protease A from dormant seeds of cotton plants of the Tashkent-1 variety consists of two subunits: and , differing in molecular weight and carbohydrate content and linked with one another by a disulfide bridge. The amino acid and carbohydrate compositions of the enzyme and its subunits have been determined. A comparative study of peptide maps of protease A and its - and -subunits and of their amino acid compositions has permitted the assumption that subunits and , in their turn, each consists of two polypeptide chains that are identical or very close in composition.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 741–744, November–December, 1986.     

Physicochemical properties of protease A from cotton seeds

It has been found that protease A from dormant seeds of cotton plants of the Tashkent-1 variety consists of two subunits: α and β, differing in molecular weight and carbohydrate content and linked with one another by a disulfide bridge. The amino acid and carbohydrate compositions of the enzyme and its subunits have been determined. A comparative study of peptide maps of protease A and its α- and β-subunits and of their amino acid compositions has permitted the assumption that subunits α and β, in their turn, each consists of two polypeptide chains that are identical or very close in composition.     

Electrophoretic and zymographic characterization of proteins isolated by various extraction methods from ejaculated and capacitated boar sperms

The presented work focuses on electrophoretic and zymographic characterization of boar sperm proteins isolated by various extraction methods and on comparison of the protein profiles obtained from ejaculated and in vitro capacitated spermatozoa. Sperm proteins of ejaculated and in vitro capacitated boar sperms were isolated with the following agents: 1% v/v Triton X‐100, 1% v/v Triton X‐114, 2% v/v acetic acid, 1% m/v sodium dodecyl sulphate (SDS), 30 mM N‐octyl‐β‐D ‐glucopyranoside (OBG), rehydration buffer (RHB) for isoelectric focusing and finally by the freezing–thawing approach. The extracts were characterized in terms of 1‐DE, 2‐DE protein profiles, 1‐DE glycoprotein staining and proteinase and hyaluronidase substrate zymographic profiles. The results have shown quantitative and qualitative differences in 1‐DE protein and glycoprotein profiles with respect to the employed isolation approach. These differences were seen even more clearly in 2‐DE protein profiles, where it was possible to distinguish the presence/absence, changes in relative abundance and pI/M_r shifts of various protein spots. Proteinase and hyaluronidase zymograms supported the prediction that various isolation protocols result in various profiles of enzymatically active molecules.     

Physicochemical properties of amorphous silicon dioxide produced from nepheline

The properties of silicon dioxide precipitates produced by acid processing of nepheline have been investigated. Regardless of the production method, silicon dioxide takes an intermediate position between commercial silica gel and white soot in terms of the structure and some physicochemical properties, this position determining possible applications of this product.     

Synthesis and properties of a new chelating resin containing the oxime group

A macroreticular polystyrene-based chelating resin with oxime and diethylamino functional groups has been synthesized. The resin is stable in acid and alkaline solutions; no decrease in nitrogen content or capacity for sorption of copper(II) is observed when it is exposed to 3M hydrochloric acid and 1M sodium hydroxide for 7 days. The resin has higher selectivity for copper(II) than for other metal ions tested and the time required for 50% uptake of copper(II) is 15 min. The highest capacity for copper(II) is 2.0 mmole/g at pH 6.0. In a column operation, quantitative recovery of copper(II) is achieved by elution with 1M hydrochloric acid, and the resin can be used repeatedly.     

Physicochemical properties and stability of the emulsion prepared with various emulsifiers for enteral nutrition preparations

The mean diameter of emulsion droplets prepared using three different emulsifiers (egg yolk lecithin alone, egg yolk lysolecithin alone, and a mixture of egg yolk lecithin and lysolecithin) was investigated. Considering the nasal administration of enteral nutrients or that through gastric/jejunal fistulae, the stability of each emulsion with artificial gastric fluid (pH 1.2) or intestinal fluid (pH 6.8) was investigated. When adding artificial intestinal fluid, all emulsions prepared with various emulsifiers (egg yolk lecithin, egg yolk lysolecithin, soybean lecithin, soybean lysolecithin, DK ester^® F-140, and Sunsoft^® A-141E) were stable. On the other hand, when adding artificial gastric fluid, emulsions prepared with egg yolk lysolecithin or Sunsoft^® A-141E were stable, but there was a reduction in the stability of emulsions prepared with the other emulsifiers, with an increase in the particle size. Based on these results, we prepared an emulsion using a natural component-derived emulsifier for enteral nutrients, egg yolk lysolecithin, and clarified the pH change-related stability of the emulsion.     

Physicochemical and tensile properties of alkaline-treated new natural cellulosic Gossypium arboreum fiber

This article describes the characterization of novel natural lignocellulosic bark fibers extracted from the stem of the Gossypium arboreum (cotton) plant. The G. arboreum stem fibers were treated with 5% (w/v) aqueous NaOH solution for different soaking times, and the Fourier transform infrared spectroscopy analysis was conducted to examine the chemical compounds of the raw and treated fibers. The cellulose content improved from 70.06 to 83.91% after the treatment. The X-ray diffraction results indicate that the crystalline index and size were enhanced. Thermogravimetric analysis was performed to study the thermal properties and found that the thermal stability was higher for the treated fibers. The tensile strength and modulus were increased for the alkaline-treated fibers compared to the untreated fibers.     

Asymmetric synthesis of (+)-altholactone: a styryllactone isolated from various Goniothalamus species

The asymmetric total synthesis of (+)-altholactone (1), a member of the styryllactone family of natural products displaying cytotoxic and antitumor activities, is described. Key steps include a RAMP-hydrazone alpha-alkylation (RAMP=(R)-1-amino-2-methoxymethylpyrrolidine) of 2,2-dimethyl-1,3-dioxan-5-one, a boron-mediated aldol reaction, a six- to five-membered ring acetonide shuffling, an oxidative 1,5-diol to delta-lactone conversion and a stereoselective ring-closure to generate the annulated tetrahydrofuran moiety with inversion of configuration.     

In silico analyses of a new group of fungal and plant RecQ4-homologous proteins

Bacterial and eukaryotic RecQ helicases comprise a family of homologous proteins necessary for maintaining genomic integrity during the cell cycle and DNA repair. There is one known bacterial RecQ helicase, and five eukaryotic RecQ helicases that have been described: RecQ1p, RecQ4p, RecQ5p, Bloom, and Werner. While the biochemical functions of Bloom and Werner helicases are well understood, the same is not true for RecQ4p helicase. RecQ4p mutations lead to pathologies like Rothmund-Thompson syndrome (RTS), RAPADILINO, and Baller-Gerold syndrome (BGS). Until now, RecQ4p helicases had only been described in metazoans, and their presence in organisms like fungi and plants were not known. Thus far only one RecQ-homologous protein (Sgs1p), similar to Bloom helicase, has been described in fungal genomes. In the present study we employed an in silico approach, and successfully identified and characterized a second RecQ helicase from the genomes of different fungal and two plant species that shows similarity to metazoan RecQ4 proteins. An in-depth phylogenetic analysis of these new fungal and plant RecQ4-like sequences (termed Hrq1p) indicated that they are orthologous to the metazoan RecQ4p. We employed hydrophobic cluster analysis (HCA) and three-dimensional modeling of selected Hrq1p sequences to compare conserved regions among Hrq1p, human RecQ4p and bacterial RecQp. The results indicated that Hrq1p sequences, as previously observed for metazoan RecQ4 proteins, probably act in genomic maintenance and/or chromatin remodeling in fungal and plant cells.