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Mechanism of antibacterial activity of silver and praseodymium-loaded white carbon black

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Journal of Rare Earths 2010年第S1期28卷 442-445页

作者：张彬林艳唐晓宁许寅华谢刚 faculty of science Kunming University of Science and Technology faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology

This paper investigated the antibacterial mechanism of the Ag-Pr-antibacterial white carbon *** sol-gel method was used to prepare the carrier:white carbon *** ion was selected to be the antibacterial ion,and praseodymium nitrate was selected to be the *** structure and antibacterial mechanism of this new inorganic antibacterial material were characterized by laser particle size analyzer,scanning electron microscope(SEM) techniques,energy dispersive spectrum(EDS) analysis,and antibacterial activity test(Escherichia coli as experimental bacterium).Results showed that the particle size of Ag-Pr-antibacterial White carbon black was less than 30 μm with a narrow size ***+ is combined into the white carbon black by both the mode of ion exchange and the mode of adsorption *** bacteriostasis rate of the Ag-Pr-antibacterial white carbon black was higher than that of the general Ag-antibacterial white carbon *** antibacterial activity of Ag-Pr-antibacterial white carbon black was caused by the combination of contact and stripping antibacterial *** result also indicated that this new inorganic antibacterial material had good thermal and light stability.

关键词： inorganic antibacterial material white carbon black praseodymium nitrate antibacterial mechanism rare earths

Observation of wedge waves and their mode transformation by laser ultrasonic technique

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Chinese Optics Letters 2011年第2期9卷 66-68页

作者：贾静沈中华王丽娟袁玲 faculty of science Nanjing University of Science and Technology

Wedge waves （WWs） in wedges, including their dispersion characteristics and mode transformation, are investigated using the laser ultrasound technique. Pulsed laser excitation and optical deflection beam method for detection are used to record WWs. Numerous WWs are detected by scanning the excitation laser along the wedge tip. Dispersions of WWs are obtained by using the two-dimensional （2D） Fourier transformation method, and different WW orders are revealed on the wedges. Mode transformation is determined by fixing the distance between the excitation and detection position, as well as by scanning the samples along the normal direction of the wedge tip.

关键词： Dispersion (waves) Fourier analysis Fourier transforms Laser excitation Ultrasonic testing Ultrasonics

Catalytic reduction of N_2O by CO over Pt_lAu-m^- clusters:A first-principles study

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Chinese Physics B 2015年第9期24卷 557-561页

作者：米鸿韦世豪段香梅潘孝胤 Department of Microelectronic science and Engineering Faculty of ScienceNingbo University Department of Physics Faculty of ScienceNingbo University

Based on the density functional theory, we investigate negatively charged clusters PtlAum^-（l ＋ m = 4）, which show significant catalytic properties in the simultaneous removal of N2O and CO. We find that in these clusters, the platinum atom acts as the adsorption center for N2O, the gold and Pt atoms act as electron donors during the reaction, and the charge transfers from the bimetallic cluster to the N2O molecule. As the proportion of Au in the cluster increases, the d band center shifts down further away from the Fermi level, meanwhile more charge is transferred to the N2O molecule, resulting in weaker N–O bond strength. Therefore bimetallic cluster PtAu3^- shows better catalytic properties than the other clusters,especially pure Pt4^- and Au4^-clusters. This means that there is a synergetic effect between the Pt and Au atoms in the negatively charged bimetallic clusters. Our results help to reveal the mechanism of PtlAum^- bimetallic clusters as excellent catalysts.

关键词： bimetallic cluster translate state catalytic property potential energy surface

A comprehensive study for mass attenuation coefficients of different parts of the human body through Monte Carlo methods

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Nuclear science and Techniques 2016年第3期27卷 31-39页

作者： E.E.Ermis F.B.Pilicer E.Pilicer C.Celiktas Physics Department Faculty of ScienceEge University Physics Department Faculty of Arts and ScienceUludag University

The gamma-ray mass attenuation coefficients of blood,bone,lung,eye lens,adipose,tissue,muscle,brain and skin were calculated at different energies(60,80,150,400,500,600,1000,1250,1500,and 2000 keV) by various theoretical methods such as FLUKA,GEANT4 Monte Carlo(MC) methods and XCOM program in this *** coefficients were also compared with the National Institute of Standards and Technology(NIST) *** results were highly in accordance with each other and NIST *** results showed that FLUKA was quite convenient in comparison to GEANT4 in the calculation of the mass attenuation coefficients of the used human body samples for low-energy photons(60,80,and 150 keV) when compared with the NIST values.

关键词：质量衰减系数蒙特卡洛方法 Geant4 部位 NIST 美国国家标准能量计算眼晶状体

Evaluations of larvicidal activity of medicinal plant extracts to Aedes aegypti （Diptera： Culicidae） and other effects on a non target fish

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Insect science 2006年第3期13卷 179-188页

作者： SUWANNEE PROMSIRI AMARA NAKSATHIT MALEEYA KRUATRACHUE USAVADEE THAVARA The Biology Program Faculty of Science Rajabhat Songkhla University Songkhla province Department of Biology Faculty of ScienceMahidol university Bangkok National Institute of health Department of Medical Science Ministry'of Public Health Nonthaburi province Thailand

A preliminary study was conducted to investigate the effects of the extracts of 112 medicinal plant species, collected from the southern part of Thailand, on Aedes aegypti. Studies on larvicidal properties of plant extracts against the fourth instar larvae revealed that extracts of 14 species showed evidence of larvicidal activity. Eight out of the 14 plant species showed 100% mosquito larvae mortality. The LC50 values were less than 100μg/mL （4.1μg/ mL-89.4μg/mL）. Six plant species were comparatively more effective against the fourth instar larvae at very low concentrations. These extracts demonstrated no or very low toxicity to guppy fish （Poecilia reticulata）, which was selected to represent most common non-target organism found in habitats ofAe. aegypti, at concentrations active to mosquito larvae. Three medicinal plants with promising larvicidal activity, having LC50 and LC50 values being 4.1 and 16.4 μg/mL for Mammea siamensis, 20.2 and 34.7 μg/mL forAnethum graveolens and 67.4 and 110.3μg/mL forAnnona muricata, respectively, were used to study the impact of the extracts on the life cycle ofAe. aegypti. These plants affected pupal and adult mortality and also affected the reproductive potential of surviving adults by reducing the number of eggs laid and the percentage of egg hatchability. When each larval stage was treated with successive extracts at the LC50 value, the first instar larvae were found to be very susceptible to A. muricata and the second instar larvae were found to be susceptible to A. graveolens, while the third and fourth instar larvae were found to be susceptible to M. siamensis. These extracts delayed larval development and inhibited adult emergence and had no adverse effects on P. reticulata at LC50 and LC50 values, except for the M. siamensis extract at its LC50 value.

关键词： Aedes aegypti guppy fish larvicidal activity medicinal plants Poecilia reticulata

A monoclonal antibody against Lates calcarifer vitellogenin and a competitive ELISA to evaluate vitellogenin induction after exposure to xenoestrogen

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Journal of Environmental sciences 2019年第1期31卷 325-333页

作者： Witchuda Prasatkaew Phochit Nanthanawat Nanthika Khongchareonporn Sutin Kingtong Environmental science program Faculty of Science Burapha University Department of Biotechnology Faculty of Science Burapha University The Institute of Biotechnology and Genetic Engineering Chulalongkorn University Department of Biology Faculty of Science Burapha University

A monoclonal antibody specific to sea bass(Lates calcarifer) vitellogenin(VTG) was developed,for use as a tool for monitoring endocrine disrupting chemicals(EDCs). VTG was induced in sea bass by intramuscular injection of 17β-estradiol(E_2: 2 mg/kg) every three days. Blood was collected three days after the last injection. Plasma VTG was then purified by chromatography in hydroxyapatite and a sephacryl-S300 column. Characterizations of purified VTG were done by phospholipoglycoprotein staining on a native-PAGE with confirmation by mass spectrometry(LC-MS/MS). Antibody was raised in mice by injection of purified VTG. After monoclonal antibody production, the hybridoma clone No. 41(MAb-sea bass VTG 41)was selected and developed for quantification of VTG by competitive enzyme-linked immunosorbent assay(ELISA). The ELISA method was sensitive with a detection limit of VTG 40 ng/mL. MAb-sea bass VTG 41 was specific to VTG from E_2-treated sea bass and others EDCs(Nonylphenol, Benzo[a]pyrene and CdCl_2). Moreover, cross-reactivity was also found in E_2-treated coral grouper(Epinephelus corallicola). The ELISA method obtained from this work can be further applied for the assessment of EDCs in Thailand and Southeast Asia's aquatic environment.

关键词： Monoclonal antibody Vitellogenin Biomarker Endocrine disrupting chemicals(EDCs) ELISA

Synergistic Efficiency of Tricresyl Phosphate and Montmorillonite on the Mechanical Characteristics and Flame Retardant Properties of Polylactide and Poly(butylene succinate) Blends

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Chinese Journal of Polymer science 2018年第5期36卷 620-631页

作者： Tunsuda Suparanon Jiratchaya Surisaeng Neeranuch Phusunti Worasak Phetwarotai Department of Materials science and Technology Faculty of Science Prince of Songkla University Department of Chemistry Faculty of Science Prince of Songkla University Bioplastic Research Unit Department of Materials Science and Technology Faculty of Science Prince of Songkla University

The main aim of this research was to investigate the synergistic influence of additives and poly（butylene succinate）（PBS） in improving both the mechanical and flame retardant properties of polylactide（PLA） blends. Tricresyl phosphate（TCP） and montmorillonite（MMT） were the additives used to improve the mechanical characteristics and fire resistance of PLA. Differential scanning calorimetry（DSC） thermograms revealed that the addition of TCP and MMT significantly affected their thermal behaviors. The results of the mechanical and morphological characterizations were in agreement with the changes in thermal behavior. The impact strength and limiting oxygen index（LOI） value of PLA significantly increased with the presence of PBS. The failure mode of the blends as evidenced by scanning electron microscopy（SEM） changed from brittle to ductile. The addition of TCP and MMT produced excellent anti-dripping and self-extinguishing behaviors of the blends, achieving V-0 rating. For the PLA/PBS blends, the synergistic combination of PBS and additives led to an acceleration of cold crystallization, a significant increment of flexibility and impact toughness, and an improvement of flame retardancy.

关键词： Polylactide Poly(butylene succinate) Blend Flame retardant Impact toughness

Paraconductivity study in ErBa_2Cu_(3-x)M_xO_(7-δ)(M=Zn, Fe) superconductors

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Chinese Physics B 2013年第11期22卷 562-568页

作者： A.Sedky S.B.Mohamed Physics Department Faculty of Science King Faisal University Physics Department Faculty of Science Assiut University

We report here the paraconductivity of ErBa2Cu3-xMxO7-δ （M = Zn and Fe） superconductors. The logarithmic plots of excess conductivity Δσ and reduced temperature C reveal two different exponents corresponding to crossover temperature as a result of shifting the order parameter from 2 to 3. The first exponent in the normal field region is close to 1, in which the order parameter dimensionality （OPD） is 2. The second exponent in the critical field region is close to 0.5, in which the OPD is 3. The coherence length, interlayer coupling, interlayer separation and carrier concentration decrease with increasing doping content, and their values for Fe samples are different from those of Zn samples. While anisotropy is increased with increasing doping content, it is generally higher for a Zn sample than that for an Fe sample. We also estimate several physical parameters such as upper critical magnetic fields in the a–b plane and along the c axis （Bab and Bc）, and critical current density J at 0 K. Although Bab and Bc are generally increased with doping content increasing, the value of Bab is found to be twice more than that of Bc. A similar behavior is obtained for J （0 K） and its value is higher in the Fe sample than that in the Zn sample. These results are discussed in terms of oxygen deficiency, localization of carriers, and flux pinning, which are produced by doping.

关键词： ceramics chemical synthesis X-ray diffraction electrical properties transport properties

Bending of orthotropic plates resting on Pasternak's foundations using mixed shear deformation theory

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Acta Mechanica Sinica 2011年第6期27卷 956-962页

作者： A.M.Zenkour Department of Mathematics Faculty of Science King AbdulAziz University Department of Mathematics Faculty of Science Kafrelsheikh University

The mixed first-order shear deformation plate theory（MFPT） is employed to study the bending response of simply-supported orthotropic *** present plate is subjected to a mechanical load and resting on Pasternak＇s model or Winkler＇s model of elastic foundation or without any elastic *** examples are presented to verify the accuracy of the present *** results for deflection and stresses are *** proposed MFPT is shown simplely to implement and capable of giving satisfactory results for shear deformable plates under static loads and resting on two-parameter elastic *** results presented here show that the characteristics of deflection and stresses are significantly influenced by the elastic foundation stiffness,plate aspect ratio and side-to-thickness ratio.

关键词： Mixed theory Bending Rectangular plates Pasternak's model