Search

In this study, the antibacterial characteristics and mechanism of Cordyceps cicadae polysaccharide were determined. A water-soluble polysaccharide from Cordyceps cicadae was separated, and antibacterial activity against common pathogens was investigated by Oxford cup method. To investigate its antibacterial mechanism, the change of bacterial ( Escherichia coli as the indicator bacteria) growth curve, electric conductivity, alkaline phosphatase (AKP) and β-galactosidase activity were measured. And the mycoprotein, membrane protein were also studied. The results showed that Cordyceps cicadae polysaccharide had strong antibacterial activity against Escherichia coli , Staphyloccocus aureus , Bacillus subtilis , Salmonella paratyphi and Pseudomonas aeruginosa . The minimum inhibitory concentration (MIC) to Escherichia coli was 0.10 mg/mL. In addition, the electric conductivity, AKP and β-galactosidase activity in microbial broth increased. The growth curve, mycoprotein, membrane protein changed. Our results revealed that Cordyceps cicadae polysaccharide exerted its bactericidal activity by damaging bacterial cell wall and cell membranes, increasing the cell permeability which resulted in the structural lesions and release of cell components, thus led to cell death. [ABSTRACT FROM AUTHOR]

To enhance the survival ability of Enterococcus faecalis HZNU P2 ( E. faecalis HZNU P2), soy protein–alginate microspheres used as the carriers were studied in this work. Characteristics of free and encapsulated cells under simulated conditions were investigated. The results so obtained showed that the viability of encapsulated cell did not decrease after 2 h incubation in simulated gastric fluid (SGF) at pH 2.5 and 2.0. Encapsulated cells experienced only minor viability reduction in bile salt solution after 1 or 2 h treatment. The viability of encapsulated cells was fully preserved after 21 days of storage at 4 °C, and only lost 0.70 and 2.0 Log CFU/g after 21 days of storage at 25 and 37 °C, respectively. Encapsulated cells could be released in simulated intestine fluid (SIF) with a fast rate. This study indicates that soy protein–alginate is a good encapsulation carrier for protecting E. faecalis HZNU P2 against adverse conditions. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a new encapsulation carrier was applied in order to improve the survival of Lactobacillus bulgaricus (L. bulgaricus). L. bulgaricus was encapsulated in alginate–milk microspheres prepared by extrusion method. Around 100% encapsulation yield was achieved. The tolerance of encapsulated L. bulgaricus to adverse environments such as low pH (pH 2.0 and 2.5), high concentration of bile salt (1.0% and 2.0%) and long time storage (1month), was investigated. Release characteristic of encapsulated L. bulgaricus in Simulated Intestine Fluid (SIF) was also studied. The results showed that encapsulation could improve the tolerance of L. bulgaricus to adverse environments. The viability of encapsulated L. bulgaricus did not change after 120min incubation in Simulated Gastric Fluid (SGF) pH 2.5. The viability of encapsulated L. bulgaricus could be kept more than 8logCFU/g after 120min incubation in SGF pH 2.0. The viability of encapsulated L. bulgaricus in 1% bile salt solution was reduced from 9.98logCFU/g microspheres to 9.24 and 8.48logCFU/g microspheres after 1 and 2h incubation, respectively. Around 1.3 and 2.1logCFU/g microspheres were reduced after 1 and 2h exposure in 2% bile salt solution, respectively. Full viability of encapsulated L. bulgaricus could be preserved after 1month’s storage at 4°C. L. bulgaricus encapsulated in alginate–milk microspheres could be completely released in 1h. These studies demonstrated encapsulation of L. bulgaricus in alginate–milk microspheres is an effective protection technique against extreme simulated gastrointestinal environment. [Copyright &y& Elsevier]

Abstract: We studied the distributions of calretinin and calbindin immunoreactivity in subdivisions of the mouse medial geniculate body and the adjacent paralaminar nuclei. We found that the vast majority of labeled cells in the dorsal division of the medial geniculate body were immunoreactive for calbindin-only, whereas most of the remaining labeled cells were double-labeled. Very few calretinin+ only cells were observed. By contrast, we observed significant proportions of calbindin+ only, calretinin+ only and double-labeled cells in the medial division of the medial geniculate body. Further, the distributions of calbindin-only, calretinin-only and double-labeled cells did not differ between the medial division of the medial geniculate body, the suprageniculate nucleus, the peripeduncular nucleus and the posterior intralaminar nucleus. We found essentially no somatic staining for either calbindin or calretinin in the ventral division of the medial geniculate body. These data suggest that there are distinct neurochemical differences between the two non-lemniscal auditory thalamic nuclei. In addition, these data extend previous observations that the medial division of the medial geniculate body shares many properties with the paralaminar group of nuclei. [Copyright &y& Elsevier]

Abstract: Gamma irradiated LiK0.97(NH4)0.03SO4 (LKS) and Li2KNH4(SO4)2 (LKAS) single and powder crystals were studied by electron paramagnetic resonance (EPR) technique in the temperature range of 113–373K. The species, responsible for the EPR spectrum, were found to be , and radicals. The principle values of the g and hyperfine tensors were found for each crystal. The spectra change significantly in the temperature range from 113 to 373K. These changes were attributed to structural phase transitions. [Copyright &y& Elsevier]

Abstract: Nuclease p1 produced by Penicillium citrinum was purified and characterized. Fermentation was carried out for 49h for optimum production. The enzyme was purified to homogeneity according to SDS-PAGE by thermal deactivation, ultrafiltration, (NH4)2SO4 precipitation, phenyl sepharose chromatography, ion-exchange chromatography and gel filtration. This protocol improved 93-fold purification and 5.4% recovery of enzyme activity. The molecular mass of nuclease p1 from Penicillium citrinum was estimated to be in the range from 43 to 44kDa. The enzyme showed an obligate requirement for Zn2+ for activity. K+ had a significant effect on enzyme activity. Mg2+ and Ca2+ had a slight positive effect on enzyme activity. While Cu2+, Co2+, Al3+, SDS and Triton X-100 were strong inhibitors of nuclease p1. The enzyme was completely stable in the pH range from 5 to 6.5 and had a pH optimum of 5.4. The optimum temperature of nuclease p1 was 69°C and enzyme was stable up to 70°C. K m and V max for the purified enzyme were 24.28mg/ml and 0.36mg/mlmin, respectively, with RNA as substrate. [Copyright &y& Elsevier]

Abstract: Some renal stones were investigated by electron paramagnetic resonance of their untreated, UV-photolyzed and gamma-irradiated states. Powder X-ray diffraction technique indicated that the renal stones were made mainly from , , and . Before radiation treatment, the renal stones yielded a signal that could be attributed to a radical. UV-photolysis seems to slightly increase the intensity of this signal, but does not produce any new centres. Gamma-irradiation initially gives and radicals, and while the intensity of the signal decreases, the intensity of the signal increases as time elapses. [Copyright &y& Elsevier]

Total M shell X-ray production cross section for 11 elements with 69 ⩽ Z ⩽ 92 have been measured using an incident photon energy of 5.96 keV. Measurements have been performed using an 55Fe annular source and a Si(Li) detector. Average M shell fluorescence yield at each incident photon energy has been deduced, using the experimental total M X-ray production cross section and theoretical M shell photoionization cross section. Present experimental results are compared with other experimental and theoretical values. Reasonable agreement (to within 0.3–28%) is typically obtained between present and other experimental and theoretical values. [Copyright &y& Elsevier]

Some drugs, used mainly in treatment of some neurological diseases and hypertension were exposed to γ-irradiation, and the samples were investigated by electron paramagnetic resonance (EPR). The observed spectra were interpreted in terms of some type of alkyl and amine radical fragments. The spectra were computer simulated and the g values of the radicals and the hyperfine structure constants of the free electron with nearby protons were determined. The species were found to be stable at room temperature for more than a year. The samples were found to display no EPR signal without irradiation. [Copyright &y& Elsevier]

Abstract: Half-metallic ferromagnetic full-Heusler alloys containing Co and Mn, having the formula Co2MnZ where Z is a sp element, are among the most studied Heusler alloys due to their stable ferromagnetism and the high Curie temperatures which they present. Using state-of-the-art electronic structure calculations we show that when Mn atoms migrate to sites occupied in the perfect alloys by Co, these Mn atoms have spin moments antiparallel to the other transition metal atoms. The ferrimagnetic compounds, which result from this procedure, keep the half-metallic character of the parent compounds and the large exchange-splitting of the Mn impurities atoms only marginally affects the width of the gap in the minority-spin band. The case of [Co1−x Mn x ]2MnSi is of particular interest since Mn3Si is known to crystallize in the Heusler lattice structure of Co2MnZ compounds. Robust half-metallic ferrimagnets are highly desirable for realistic applications since they lead to smaller energy losses due to the lower external magnetic fields created with respect to their ferromagnetic counterparts. [Copyright &y& Elsevier]

Abstract: In order to investigate the characterizations of chitosan nano-particles prepared by ionization gelation method, neutral proteinase was selected as a model enzyme to assess its potential applicability for the enzyme immobilization. The characterizations of immobilized enzyme were studied. The highest enzyme activity of immobilized enzyme was allowed at pH 7.5, identical to that of free enzyme, but the range of the optimum pH was broadened. The optimal temperature of immobilized enzyme was 55°C, and the range of the optimum temperature was also broadened. The thermal, operational and storage stabilities of immobilized enzyme were improved after they were immobilized on chitosan nano-particles. Chitosan nano-particles were applied to protect the activity of neutral proteinase. They could improve 13.17% of neutral proteinase activity than that of free neutral proteinase at the same conditions. The Michaelis constant K m for immobilized enzyme was disclosed to 0.6629mg/ml by Line weaver-Burk plot at 40°C. [Copyright &y& Elsevier]

Abstract: The concentration of five different elements in six lichens species of different regions in Giresun and Ordu (Turkey) was determined using the energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied to the elemental analysis of lichens. An annular 50mCi 241Am radioactive source and an annular 50mCi 55Fe radioactive source were used for excitation of characteristic K X-rays. An Si(Li)detector which has a 147eV full-width at half-maximum for 5.9keV photons was used for intensity measurements. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, and barium. [Copyright &y& Elsevier]

Mass attenuation coefficients of the YBaCuO and BiPbSrCaCuO superconductors were determined at 511, 661, and 1274 keV photon energies. The samples were irradiated using 0.5 mCi 137Cs and 2 mCi 22Na radioactive sources. The photons crossing the samples were counted using a multi-channel analyzer with a NaI(Tl) detector. The Nucleus II software was used to analyze the spectra. It was observed that the mass attenuation coefficient decreases with increasing energy and increases with increasing atomic number. [Copyright &y& Elsevier]

Radiation-induced defect production in tungsten was studied by a combination of experimental and simulation methods. The analysis of structural defects was performed using multi-energy Rutherford backscattering spectroscopy in channeling configuration (multi-energy C-RBS). To create different microstructures, (111) tungsten (W) single crystals were irradiated with W ions at two different doses (0.02 and 0.2 dpa) at 290 K. Detailed transmission electron microscopy (TEM) analysis of the samples revealed the presence of dislocation lines and loops of different sizes. The RBSADEC code was used to simulate the measured C-RBS spectra, recorded with four different He beam energies along the 〈111〉 direction. For the first time for tungsten, molecular dynamics (MD) simulations of overlapping cascades were used as input. The well-known method of randomly displaced atoms (RDA) was applied for comparison. RDA does not provide a satisfactory understanding of the nature of the induced defect structure. With MD, a very good agreement between the simulated and experimental spectra was obtained for the sample prepared at a lower dose, despite the fact that the absolute defect densities are two orders of magnitude higher than those found with TEM. A discrepancy is observed for the high-dose-irradiated sample, which is ascribed to the presence of extended defects such as dislocation lines, which are clearly observed by TEM, but cannot be formed in finite size MD cells. RBSADEC with MD cells as input can describe correctly the response of the RBS signal with analysing beam energy while RDA as input gives the wrong trend. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] It is the first time to study the biological structures and function of Y. NSN using bioinformatics methods. [•] Y. NSN shared high similarity with the nuclease from Yersinia enterocolitica subsp. enterocolitica 8081. [•] Y. NSN showed good thermostability. [Copyright &y& Elsevier]

Synchrotron X-ray specular scattering measurements confirm microscopically a structural model recently inferred by very-high-resolution ellipsometry of a solid dotriacontane (n-C32H66 or C32) film formed by adsorption from solution onto a SiO2 surface. Sequentially, one or two layers adsorb on the SiO2 surface with the long-axis of the C32 molecules oriented parallel to the interface followed by a C32 monolayer with the long-axis perpendicular to it. Finally, preferentially oriented bulk particles nucleate having two different crystal structures. This growth model differs from that found previously for shorter alkanes deposited from the vapor phase onto solid surfaces. [Copyright &y& Elsevier]

The concentration of eight different elements in tobacco of different region in Akc¸aabat (Trabzon/Turkey) was determined using energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied for the elemental analysis of tobacco and its ash. An annular 50 mCi241Am radioactive source and an annular 50 mCi55Fe radioactive source were used for excitation of characteristic K X-rays. An Si(Li) detector which has a 147 eV full width at half maximum for 5.9 keV photons was used for intensity measurements. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, copper, bromine, strontium and barium. Evaluation of these elements with their potential hazards for smokers is briefly discussed. [Copyright &y& Elsevier]

In this study, six Pt(II) complexes bearing 5(6)-H or –CH3-2-phenyl or -(2′-pyridyl) or -mercaptomethylbenzimidazole ligands as ‘carrier groups’ were synthesized and characterized by elemental analysis, IR and 1H-NMR spectra and evaluated for their preliminary in vitro cytotoxic activity to the human RD Rhabdomyosarcoma cell line and mutagenic properties in Salmonella typhimurium strains TA 98 and TA 100 in the absence of the S9 rat liver fraction. The preliminary test results showed that the complexes had slightly greater cytotoxic activity on the RD cell line at 1 μM concentration than cisplatin. Among the compounds tested for their mutagenicity, Pt(II) complexes of 2-(2′-pyridyl)- and 5(6)-methyl-2-(2′-pyridyl)benzimidazoles were found to be mutagenic. A comparative study of the MIC (minimum inhibitory concentration) values indicated that, in general, there were no differences between the poor antimicrobial activity values of the ligands and their Pt(II) complexes with respect to the tested microorganisms. These results suggest that the synthesized Pt(II) complexes should be considered for further antitumor activity studies. [Copyright &y& Elsevier]