Digital socialization: Insights into interpersonal communication motives for socialization in social networks among undergraduate students.

Social interactions and communication between individuals have been completely transformed by digital technology (DT). People from all around the world can now communicate with each other thanks to social media platforms. The main focus of this study is on interpersonal communication motives (ICM) in social networks (SNs), aiming to examine how Ethiopian undergraduate students socialize in relation to digital technologies (DTs).

Raman Spectroscopy Applied to Early Detection of Infection in Milk.

Detecting in milk presents a significant challenge for the dairy industry given that traditional methods are time-consuming and not specific for these bacteria. Microbiological techniques are expensive and require qualified personnel. , in the form of spores, can withstand pasteurization and revert to its vegetative form during cheese aging.

Clinical enzymes as possible immunological biomarkers in the diagnosis of malaria, human African and American trypanosomiasis.

Peripheral blood smear microscopy still remains the gold standard for diagnosing malaria and trypanosomiasis. Microscopy is a labor-intensive process and requires great amount of skill to accomplish. Even though cheap and easy to perform, it still has several limitations.

The interdigitated gel phase in mixtures of cationic and zwitterionic phospholipids.

To examine the phase behavior of mixtures of zwitterionic and cationic lipids we used three derivatives of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). All three lipids are uniquely capable of spontaneously forming the interdigitated gel phase (LβI) under typical hydration conditions. The P-O-ethyl derivative, 1,2-dipalmitoyl-sn-glycero-3-ethylphosphocholine (EDPPC), was chosen as the cationic lipid.

Effects of cis- and trans-unsaturated lipids on an interdigitated membrane.

The effects of adding cis- and trans-unsaturated lipid to a fully interdigitated membrane were examined using differential scanning calorimetry (DSC) and X-ray diffraction. A monofluorinated analog of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) was used as the interdigitated lipid. The single fluorine atom on the end of the sn-2 chain allows 1-palmitoyl-2-(16-fluoropalmitoyl)sn-glycero-3-phosphocholine (F-DPPC) to spontaneously form the interdigitated gel phase (LβI) below the main transition temperature (Tm).

Influence of the interdigitated gel phase in mixtures of ether-linked and monofluorinated ester-linked phospholipids.

To evaluate the influence of the hydrocarbon chain linkage on the thermodynamic phase behavior of spontaneously interdigitating lipids, mixtures of ether-linked 1,2-di-O-hexadecyl-phosphocholine (DHPC) and ester-linked 1-palmitoyl-2-[16-fluoropalmitoyl]sn-glycero-3-phosphocholine (F-DPPC) were studied. A combination of differential scanning calorimetry (DSC), fluorescence spectroscopy, and transmittance spectrophotometry was used. Small amounts of F-DPPC increase the pretransition temperature (T(p)) between the interdigitated gel phase (L(β)I) and the ripple gel phase (P(β)').

Effects of cholesterol on phospholipid membranes: inhibition of the interdigitated gel phase of F-DPPC and F-DPPC/DPPC.

Unlike the parent phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), the monofluorinated analog, 1-palmitoyl-2-(16-fluoropalmitoyl)sn-glycero-3-phosphocholine (F-DPPC), spontaneously forms an interdigitated gel phase (L(β)I) below the main transition temperature (T(m)). We have examined the effects of introducing cholesterol to F-DPPC and 1:1 F-DPPC/DPPC membranes using a combination of DSC, optical density, fluorescence intensity and polarization, (31)P NMR, and X-ray diffraction techniques. Cholesterol increases the fluidity of the gel phase, broadens the main transition, and decreases the main transition enthalpy.

Screening of species-specific lactic acid bacteria for veal calves multi-strain probiotic adjuncts.

The selection of promising specific species of lactic acid bacteria with potential probiotic characteristics is of particular interest in producing multi species-specific probiotic adjuncts in veal calves rearing. The aim of the present work was to select and evaluate in vitro the functional activity of lactic acid bacteria, Bifidobacterium longum and Bacillus coagulans strains isolated from veal calves in order to assess their potential use as multi species-specific probiotics for veal calves. For this purpose, bacterial strains isolated from faeces collected from 40 healthy 50-day-calves, were identified by RiboPrinter and 16s rRNA gene sequence.

Effects of pentanol isomers on the phase behavior of phospholipid bilayer membranes.

Differential scanning calorimetry (DSC) was used to analyze the thermotropic phase behavior of dipalmitoylphosphatidylcholine (DPPC) bilayers in the presence of pentanol isomers. The concentration of each pentanol isomer needed to induce the interdigitated phase was determined by the appearance of a biphasic effect in the main transition temperatures, the onset of a hysteresis associated with the main transition from the gel-to-liquid crystalline phase, and the disappearance of the pretransition. Lower threshold concentrations were found to correlate with isomers of greater alkyl chain length while branching of the alkyl chain was found to increase biphasic behavior.

Properties of phosphatidylcholine in the presence of its monofluorinated analogue.

In aqueous solution, the monofluorinated phospholipid 1-palmitoyl-2-[16-fluoropalmitoyl]sn-glycero-3-phosphocholine (F-DPPC) interdigitates without the use of inducing agents. To understand the thermal and physical properties of this unique lipid, F-DPPC was combined with the non-fluorinated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and 1,2-diarachidoyl-sn-glycero-3-phosphocholine (DAPC). Differential scanning calorimetry (DSC) was used to determine the miscibility and thermotropic phase behavior of these binary lipid mixtures.

Effects of butanol isomers on dipalmitoylphosphatidylcholine bilayer membranes.

Differential scanning calorimetry and (31)P-NMR were used to study the effects of butanol isomers on the thermotropic phase behavior of dipalmitoylphosphatidylcholine (DPPC) bilayers. The threshold concentration for the onset of interdigitation for each isomer was determined by the disappearance of the pretransition and the onset of a large hysteresis between the heating and cooling scans of the gel-to-liquid main transition. The threshold concentration was found to correlate with increased solubility of the isomers in the aqueous phase, led by tert-butanol.

Subgel studies of dimyristoylphosphatidylcholine bilayers.

It is known that when bilayers of some saturated phosphatidylcholines are stored for 3 or more days at approximately 0 degrees C, a lamellar subgel (Lc) phase is detected at temperatures below the pretransition by differential scanning calorimetry (DSC). However, the subgel (Lc) phase and the corresponding subtransition (Lc--> Lbeta') for dimyristoylphosphatidylcholine (DMPC) has not been clearly characterized. In this study, using the temperature jump protocol first developed by Tristram-Nagle et al.

Effects of alcohols on lipid bilayers with and without cholesterol: the dipalmitoylphosphatidylcholine system.

Differential scanning calorimetry is a useful method to study the thermotropic phase transitions of a phospholipid bilayer. In the present study DSC is used to determine the effects of methanol and ethanol on DPPC and DPPC/2 mol% cholesterol bilayers. The biphasic effect of the main transition and the presence of an extra peak on the DSC cooling scans were observed above certain alcohol concentrations.

Effects of ethanol on lipid bilayers with and without cholesterol: the distearoylphosphatidylcholine system.

Differential scanning calorimetry (DSC) and fluorescence spectroscopy are useful techniques for investigating the phase transitions of phospholipid bilayers. In this study, these methods have been extended to determine the effects of ethanol on DSPC and DSPC/2 mol.% cholesterol bilayers.

A polyphasic approach to highlight genotypic and phenotypic diversities of Lactobacillus helveticus strains isolated from dairy starter cultures and cheeses.

In the present work, 67 strains of Lactobacillus helveticus isolated from whey starter cultures and cheeses were identified and grouped by genotypic and phenotypic methods. Strains were identified by sugar fermentation pattern, by cell-wall protein profile, and by probe hybridisation. Phenotypic diversity was evaluated by a chemometric model taking into account biochemical characteristics (i.

Studies on the size and stability of chlorpromazine hydrochloride nanostructures in aqueous solution.

The mean aggregate number (MAN) of the antipsychotic drug chlorpromazine hydrochloride (CPZ) nanostructure was investigated by fluorescence quenching using 9-methylanthracene (9-MA) as the quencher. The method was designed to take advantage of the intrinsic fluorescent properties of CPZ. The validity of this method was supported by the results obtained for the MAN which was determined to be approximately 37 for a solution of 10 mM CPZ in 0.

Insights into the dynamics of DMSO in phosphatidylcholine bilayers.

The solvation effects of dimethyl sulfoxide (DMSO) on the phase stability of dimyristoylphosphatidylcholine (DMPC) have been fully characterized using differential scanning calorimetry (DSC) and fluorescence spectroscopy with 1,6-diphenyl-1,3,5-hexatriene (DPH). The temperatures of the sub-, pre-, and main transitions of DMPC were found to increase linearly with increasing mole fraction of DMSO up to mole fraction X=0.13 DMSO/H(2)O.

Molecular identification and cluster analysis of homofermentative thermophilic lactobacilli isolated from dairy products.

Twenty-five strains of thermophilic lactobacilli isolated from yoghurt and from semi-hard and hard cheeses (in parallel with nine type or reference strains) were identified and grouped according to their genetic relatedness. Strains were identified by sugar fermentation patterns using the "API 50 CHL" galleries, by species-specific DNA probes in dot-blot hybridization experiments, by amplification and restriction analysis of the 16S rRNA gene (ARDRA) and by polymerase chain reaction (PCR) using species-specific oligonucleotide primers. Strains were classified as Lactobacillus delbrueckii subsp.

The acute phase response in the Sudan plated lizard, Gerrhosaurus major.

The Sudan plated lizard (Gerrhosaurus major), previously reported to be an afebrile species, was utilized in a series of experiments to test for various aspects of the acute phase response. Treatment of individuals with the antibiotic Baytril resulted in a slight (0.5 degree C) but significant reduction in mean selected body temperature (MSBT), while treatment with saline did not lower MSBT.

Hydrophobic mismatch in gramicidin A'/lecithin systems.

Gramicidin A' (GA') has been added to three lipid systems of varying hydrophobic thicknesses: dimyristoyllecithin (DML), dipalmitoyllecithin (DPL), and distearoyllecithin (DSL). The similarity in length between the hydrophobic portion of GA' and the hydrocarbon chains of the lipid bilayers has been studied by using 31P and 2H NMR. Hydrophobic mismatch has been found to be most severe in the DML bilayer system and minimal in the case of DSL.

Characterization of the transverse relaxation rates in lipid bilayers.

The 2H NMR transverse relaxation rates of a deuterated phospholipid bilayer reflect slow motions in the bilayer membrane. A study of dimyristoyl lecithin specifically deuterated at several positions of the hydrocarbon chains indicates that these motions are cooperative and are confined to the hydrocarbon chains of the lipid bilayer. However, lipid head group interactions do play an important role in modulating the properties of the cooperative fluctuations of the hydrocarbon chains (director fluctuations), as evidenced by the effects of various lipid additives on the 2H NMR transverse relaxation rates of the dimyristoyl lecithin bilayer.

Effect of chlorophyll a on the phase behavior of hydrated monogalactosyldiacylglycerols.

We have studied the effect of chlorophyll a (chl a) on the X-ray diffraction patterns and the appearance of freeze-fracture electron micrographs of aqueous dispersions of monogalactosyldiacylglycerols (MGDG), the most abundant lipid in the thylakoid membrane. In MGDG systems containing 0-18 mol% of chl a, the diffraction patterns indicate the presence of a well-ordered reverse hexagonal phase. When 30 mol% of chl a was incorporated into the MGDG, the low-angle X-ray diffraction lines of the hexagonal lattice were slightly broadened and were accompanied by additional weak lines.

Organization of chlorophyll a in bilayer membranes. The chlorophyll a/dimyristoylphosphatidylcholine system.

In order to investigate the relative importance of the hydrophobic and headgroup interactions of chlorophyll a in phospholipid bilayers, we have carried out differential scanning calorimetry (DSC) and deuterium (2H) and phosphorus (31P) nuclear magnetic resonance (NMR) experiments on the multilamellar system of chlorophyll a in dimyristoylphosphatidylcholine (DMPC). Compared to the phytol chain of chlorophyll and the previously reported distearoylphosphatidylcholine (DSPC), the acyl chains of DMPC are shorter in length by three and four carbons, respectively. A lowering in the phase-transition temperature was observed for the DMPC multilayers in the presence of chlorophyll a in the DSC thermograms and in the 31P chemical shift anisotropy measurements.

Kinetics of phosphoramide mustard hydrolysis in aqueous solution.

Hydrolysis of phosphoramide mustard was investigated using HPLC, 31P NMR, and GC-MS with specific deuterium labels. The hydrolysis of phosphoramide mustard in sodium phosphate buffers was found to follow apparent first-order kinetics. The rate of hydrolysis was temperature and pH dependent, being slower under acidic conditions.

Quantitative analysis of hair cholesterol by gas-liquid chromatography.

1. An analytical procedure has been developed for the gas-liquid chromatographic analyses of cholesterol in hair samples. 2.