Percentage Of Ag Research Articles

Preparation of magnetic Fe3O4@SiO2@CaSiO3 composite for removal of Ag+ from aqueous solution

A three-component magnetic material, namely, Fe3O4@SiO2@CaSiO3, which featuring an Fe3O4@SiO2 core and a layered porous CaSiO3 shell, was synthesized via precipitation and utilized as an adsorbent to remove Ag+ from wastewater. The structure, morphology, composition, and magnetic properties of this material were analyzed by a series of characterization techniques, and its adsorption efficiency, adsorption thermodynamics, kinetic characteristics, and recyclability were investigated in detail. The magnetic Fe3O4@SiO2@CaSiO3 composite possessed a core–shell structure, with a cotton-like morphology, a specific surface area of 75.97 m2·g−1, pore size of 11.4 nm, pore volume of 0.36 cm3·g−1, and magnetization saturation of 60.5 emu·g−1. The adsorption equilibrium data of Ag+ adsorption by Fe3O4@SiO2@CaSiO3 fitted the Redlich–Peterson model well, and the equilibrium adsorption capacity of the material for Ag+ reached 127.84 mg·g−1 at an initial concentration of 225 mg·L−1 and temperature of 293 K. Kinteic studies showed that the adsorption process conformed well to the pseudo-second-order model and reached equilibrium within 150 min. The adsorption process was endothermic, with an activation energy of 8.475 kJ·mol−1 and accompanied by AgO bonding and Ca2+ release. Therefore, the adsorption mechanism involved in Ag+ removal includes not only physisorption and ion exchange but also chemisorption, which is controlled by surface OH and O groups. The percentage of Ag+ removal tended to stabilize after five cycles of Fe3O4@SiO2@CaSiO3 reuse and but decreased by only 14.34%. Synthesized Fe3O4@SiO2@CaSiO3 exhibited excellent adsorption, regeneration, and magnetic separation performance. Thus, the synthesized Fe3O4@SiO2@CaSiO3 may potentially be applied to remove Ag+.

Characterization of Au-Ag nanoparticles biosynthesized by fungus Mariannaea sp. HJ

Biosynthesis of gold-silver alloy nanoparticles (Au-AgNPs) is a simple operation and ecological friendly, but with limited reports on the availability of fungal resources. In this study, cell-free extracts of Mariannaea sp. HJ was used to synthesize Au-AgNPs, and the effects of the different ratios of Au and Ag ion concentrations on the synthesis of Au-AgNPs were also studied. The results clearly showed that the ratio of Au and Ag ion concentrations had an impact on the composition of Au-AgNPs. With the Ag ion increasing, the color of culture supernatant changed from light purple to brown and an obvious blue shift of characteristic absorption peak was observed in UV-vis spectra, indicating an increase of the percentage of Ag in the Au-AgNPs. Transmission electron microscope showed that the morphologies of the Au-AgNPs were mainly spherical and pseudo spherical, and the average particle sizes of the Au-AgNPs at three different ion concentrations, including 0.5:0.5, 0.5:1.5 and 0.5:3.0, were 19.24 nm, 15.99 nm and 19.33 nm, respectively. X-ray diffraction results showed that the Au-AgNPs had a surface-centered cubic structure. Fourier transform infrared spectroscopy was used to characterize and speculate the involvement of -OH, -NH₃ and -COOH functional groups in the reduction and stability process of Au-AgNPs. Furthermore, 4-nitrophenol (4-NP) was used to explore catalytic activity of Au-AgNPs. Catalytic experiments demonstrated that the Au-AgNPs had a good catalytic activity on 4-NP reduction with a catalytic reaction rate constant of 7.85×10⁻³ s⁻¹. In brief, the present study suggested that Mariannaea sp. HJ could synthesize Au-AgNPs with good dispersity, and had a potential application in the catalytic reduction of nitro aromatic hydrocarbons.

The texture ordering in L10-FePt\u2013Ag nanocomposites

L10-FePt nanoparticles with different Ag percentages were prepared. The presence of 6% Ag in co-sputtering process with deposition rate of 1 {dot{A}}/text{s} at 500 °C led to the formation of FePt nanoparticles with 5–7 nm size in L10-fct phase. Moreover, Ag atoms laying in boundaries of these nanoparticles in these circumstances caused c axis to orient and (001) peak intensity in XRD spectrum to increase. This is the result of the indirect exchange interactions of Fe magnetic atoms through Ag atoms in these boundaries. Therefore, where L10-FePt grains have the most boundaries with each other, the order index would be maximum.

Enhanced Localized Surface Plasmon Resonance of Fully Alloyed AgAuPdPt, AgAuPt, AuPt, AgPt, and Pt Nanocrystals: Systematical Investigation on the Morphological and LSPR Properties of Mono-, Bi-, Tri-, and Quad-Metallic Nanoparticles.

Multi-metallic alloy nanoparticles (NPs) can offer tunable or modifiable localized surface plasmon resonance (LSPR) properties depending upon their configurational and elemental alterations, which can be utilized in various applications, that is, in photon energy harvesting, optical sensing, biomedical imaging, photocatalysis, and spectroscopy. In this work, a systematic investigation on the morphological and LSPR properties of multi-metallic alloy NPs incorporating Ag, Au, Pd, and Pt is presented on c-plane sapphire (0001). The resulting NPs exhibit much enhanced and tunable LSPR bands in the UV–VIS wavelength as compared to the previously reported mono-metallic NPs based on the considerable improvement in size and shape of nanostructures along with the electronic heterogeneity. Solid-state dewetting of sputtered bilayers (Ag/Pt), tri-layers (Ag/Au/Pt), and quad-layers (Ag/Au/Pd/Pt) is employed to demonstrate a wide variety of configurations, sizes, densities, and elemental compositions of Pt, AgPt, AuPt, AgAuPt, AgAuPt, and AgAuPdPt NPs by the systematic control of annealing temperature and deposition schemes. The distinct morphology and elemental composition of surface nanostructures are obtained by means of surface diffusion, intermixing, and surface/interface energy minimization along with the applied thermal energy. In addition, the sublimation of Ag atoms from the alloy nanostructure matrix significantly influences the structural, elemental, and thus optical properties of NPs by reducing the average size and Ag percentage in the alloy NPs. Based on the specific size, shape, and elemental composition of NPs, the excitation of LSPR is correlated to the dipolar, quadrupolar, multi-polar, and higher order (HO) modes along with the finite difference time domain simulation of local electric-field. The LSPR intensity is generally stronger with a higher percentage of Ag atoms in the alloy NPs and gradually diminished by the sublimation loss. However, even the mono-metallic and alloy NPs without Ag exhibited significantly improved and dynamic nature of plasmonic bands in the UV and VIS wavelength.

Highly reliable and transparent Al doped Ag cathode fabricated using thermal evaporation for transparent OLED applications

Abstract Here, we report a highly reliable and transparent cathode (TC) for transparent organic light emitting diode (TOLED) applications. The cathode layer is fabricated by co-deposition of silver (Ag) and aluminum (Al) metals using thermal evaporation. The atomic percentages of Al and Ag are fixed at 96 at% and 4 at%, respectively. TC shows transmittance at 520 nm (T@520nm) of 83.5% and sheet resistance as low as 7.0 Ω/□. Almost no specific agglomeration of Ag:Al (4%, 14 nm) is noticed by the thermal annealing of fabricated cathode at 85 °C, 240 h. The fabricated TOLED with this Ag:Al (4%, 14 nm) cathode shows an excellent electron injection property with a T@520nm of 83.5%, and achieved current efficiencies of 36 and 18 cd/A from bottom and top sides emissions, respectively. It is argued that the Al-doped Ag film could become an effective, feasible alternative to the existing transparent conducting electrode for TOLED applications.

Synthesis of Superparamagnetic ZnFe₂O₄-Core/Ag-Deposited ZnO-Shell Nanodiscs for Application as Visible Light Photocatalyst.

Nanodiscs with ZnFe₂O₄ core and Ag-deposited ZnO shell have been synthesized by hydrothermal method. Scanning electron microscopy (SEM) shows the morphology as nanodiscs. X-ray diffractometry (XRD), selected area electron diffractometry (SAED) and Raman spectroscopy reveal cubic ZnFe₂O₄, hexagonal ZnO and face centered cubic Ag as the constituents of the synthesized nanodiscs. Energy dispersive X-ray spectroscopy (EDS) provides the atomic percentage of Ag as 0.6. High resolution transmission electron microscopy (HRTEM) displays the core-shell structure of the synthesized nanodiscs. The specific surface area, pore volume and pore radius of the nanodiscs are 26.83 m² g-1, 0.082 cm³ g-1 and 4.88 nm, respectively. The charge-transfer resistance (RCT) of precursor ZnFe₂O₄ nanoparticles, determined by solid state impedance spectroscopy, is very much smaller than that of pristine ZnO and ZnFe₂O₄/Ag-ZnO and the RCT of ZnFe₂O₄/Ag-ZnO is larger than that of ZnO. The capacitance (C) of ZnFe₂O₄/Ag-ZnO is very much smaller than that of ZnFe₂O₄ and ZnO and the C of ZnFe₂O₄ is much larger than that of ZnO. ZnFe₂O₄/Ag-ZnO nanodiscs as well as ZnFe₂O₄ nanopowder are superparamagnetic. ZnFe₂O₄/Ag-ZnO exhibits surface plasmon resonance (SPR) in the visible region. The emission spectrum of ZnFe₂O₄/Ag-ZnO is similar to that of pristine ZnO and shows violet, blue, blue-green and green emissions due to different crystal defects in ZnO lattice. The synthesized nanodiscs display visible light photocatalysis, degrade dye completely and are reusable visible light photocatalyst. The mechanism of visible light photocatalysis is addressed.

Experimental Investigation on the Effect of Ag Addition on Ternary Lead Free Solder Alloy –Sn–0.5Cu–3Bi

Lead cannot be used in the solder material anymore due to environmental legislations which is related to the inherent toxicity of lead. This paper investigates the effect of silver (Ag) addition on the melting behavior, microstructure, and microhardness of Ternary lead free solder alloy Sn–0.5Cu–3Bi. The contact angle between Sn–0.5Cu–3Bi and Cu-substrate were also analyzed. Samples with different Ag percentages (0, 0.25, 0.5, 0.75 and 1.0 wt%) in Sn–0.5Cu–3Bi were prepared using an induction furnace, annealing furnace with argon gas. Tests were conducted for melting temperature using TG–DTA analysis, chemical composition using ICP–OES, Hardness using Vickers’s hardness tester and the microstructure using Field emission scanning electron microscopy. The obtained results were thoroughly analyzed. The results show that the Ag addition has striking positive effects on enhancing the properties of the base solder alloy. Melting point is found to be decreasing with the increase in Ag content. Hardness and contact angle were improved with the addition of Ag. The microstructure observations revealed that the Ag was uniformly distributed on the surface of the solder matrix. The recommended content of the Ag to be added into the Sn–0.5Cu–3Bi solder alloy is 1.0 wt%. With the observed better properties it can be considered as the potential alternative to lead–tin alloy.

The effect of silver doping on photoelectrochemical (PEC) properties of bismuth vanadate for hydrogen production

Bismuth vanadate (BVO) as one of the promising photoanodes suffers from low charge transport mobility and conductivity. Here, dip coating of successive layers of bismuth vanadate (BVO) precursor were utilized to prepared BVO photoanode. Ag-doped BVO electrodes were also prepared by adding a trace amount of Ag+ in the bismuth vanadate precursor and codepositing Ag with the BVO film. In the Ag-doped BVO, Ag+ ions substitutionally replaced Bi3+ ions and increased the electron concentration in BVO. The photocurrent density and photoconductivity of Ag-doped BVO were monitored by changing the loading percentage of Ag (1–5%). At optimum Ag-doping percentage (2% Ag-doped BVO), the photocurrent density is found to be 5.5-fold greater than that of pure BVO. Deterministic investigation indicated that the enhanced PEC performance of the 2% Ag-BVO was attributed to significantly increased donor concentration (30-fold), greater visible light absorption, decreased recombination process of charge carriers (9-fold), thinner space charge layer (6-fold) and reduced flat band potential (16%). The water splitting experiment showed that the total generated H2 after 2 h of irradiation for 2% Ag-BVO was estimated as 5.2 μmol cm-2 and the equivalent value for O2 was 2.70 μmol cm-2.

Endodontic Sealers Modified with Silver Vanadate: Antibacterial, Compositional, and Setting Time Evaluation.

The incorporation of nanoparticles into endodontic sealers aims at increasing antimicrobial activity of the original material. Aim. The aim of this study is to incorporate the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3, at 2.5%, 5%, and 10%) into three endodontic sealers and evaluate the antibacterial activity of freshly sealers, surface topography and chemical composition, and setting time. Material and Methods. The AgVO3 was incorporated into AH Plus, Sealer 26, and Endomethasone N at concentrations 0%, 2.5%, 5%, and 10% (in mass). The antibacterial activity of freshly sealers was assessed by direct contact with Enterococcus faecalis and CFU/mL count (n=10), surface topography, and chemical composition were measured by SEM/EDS, and the setting time was measured by Gillmore needle (n=10). The Kruskal-Wallis and Dunn statistical tests were applied (α=0.05). Results. All groups of sealers evaluated inhibited E. faecalis (p>0.05). The incorporation of AgVO3 altered the atomic proportions between components of the endodontic sealers, and the percentage of silver (Ag) and vanadium (V) increased proportionally to the concentrations of AgVO3. Topography analysis showed differences in components distribution on the surface of the specimens. The sealers incorporated with AgVO3 of AH Plus presented a lower setting time than the control group (p<0.05). For Sealer 26 and Endomethasone N, the incorporation of AgVO3 increased the setting time in relation to control group (p<0.05). Conclusions. The modification of endodontic sealers by AgVO3 increased the atomic percentage of Ag and V proportionally to the concentration of the nanomaterial and changed the atomic percentage of the sealer components and setting times. It cannot be affirmed that the AgVO3 promote differences in the antimicrobial activity of freshly sealers, and further investigations of the antimicrobial activity of the set sealers should be carried out.

Differentiating Silver Nanoparticles and Ions in Medaka Larvae by Coupling Two Aggregation-Induced Emission Fluorophores.

Although numerous studies have been conducted on the toxicity and biodistribution of AgNPs and corresponding ionic counterparts, it is still debatable whether the toxicity originates from the accumulation of particles within specific organs or is mediated by the dissolved Ag ions. To gain a better insight into the toxic mechanisms of AgNPs, two aggregation-induced emission fluorogens (AIEgens; AIEgens-coated AgNPs and a fluorogenic Ag+ sensor) were employed for the in situ visualization and quantitative analysis of distribution patterns of AIE-AgNPs and corresponding Ag ions in different organs of medaka larvae. The 96 h LC50 of AIEgens-coated AgNPs (AIE-AgNPs) was 10-20 mg/L, which was much higher than that of the citrate-coated AgNPs (Cit-AgNPs, 2.39-3.24 mg/L) and AgNO3 (0.23 mg/L), suggesting that the AIE-AgNPs were much more biocompability than Cit-AgNPs or AgNO3. The LC50 of AgNO3 was approximately 10% of the LC50 of Cit-AgNPs, which was comparable to the percentage of Ag+ released from Cit-AgNPs. The novel AIE method for the first time simultaneously analyzed the quantitative distribution patterns of AIE-AgNPs and corresponding Ag ions in different organs of medaka larvae. AIE-AgNPs and Ag ions showed distinct distribution patterns, in which AIE-AgNPs were concentrated in intestine and liver, accounting for 53.4% and 32.1% of the total AIE-AgNPs accumulated in medaka larvae, respectively. In contrast, Ag ions were accumulated mainly (92.5%) in the intestine of medaka larvae. The toxicity of AgNPs toward medaka larvae was attributed mainly to the released Ag ions which could potentially disrupt the absorptive capacity of the intestinal epithelium and induce digestive dysfunction. Our study provided a new technique for simultaneous monitoring of the AgNPs and corresponding Ag ions in the biological systems.

Uptake and impact of silver nanoparticles on the growth of an estuarine dinoflagellate, Prorocentrum minimum

Silver nanoparticles (AgNPs) are widely used and have been shown to have relatively high inherent toxicity to a range of living organisms including fish, annelids, daphnia and algae. AgNPs capped with either citrate (cit-AgNPs) or polyvinylpyrrolidone (PVP; PVP-AgNPs) were exposed to the estuarine dinoflagellate Prorocentrum minimum at a range of concentrations (1–1000 μg L−1). Transformations of the AgNPs (e.g. dissolution), along with their uptake and biological effects were measured. DLS and TEM measurements indicated a particle diameter of 15 nm for both particle types. A multi-method approach showed that both particle types underwent rapid and concentration-dependent dissolution and agglomeration. The effects were most apparent for the cit-AgNPs. With a larger total Ag addition, a larger percentage and mass of Ag was operationally defined as internalized in or strongly bound to cells, regardless of capping agent. Exposure to AgNP concentrations of 50–100 μg L−1 significantly decreased cellular growth after 72 h resulting in EC50 values of 60.5 μg L−1 (cit-AgNP), 67.1 μg L−1 (PVP-AgNP), and 30.3 μg L−1 (AgNO3(aq) control). The calculated no observed effect concentrations (NOEC) were 24.0, 19.0, 0.2 μg L−1 for cit-AgNP, PVP-AgNP and AgNO3 respectively. Using a predicted exposure concentration (PEC) of 0.116 ng L−1 for nano-Ag in the environment and predicted no effect concentrations (PNEC) of 0.02, 0.02, 0.002 μg L−1 (respectively), PEC/PNEC risk assessment ratios of <1 were determined for all treatments. This indicated no immediate concern for AgNPs toxicity to P. minimum.

Atomistic analysis of the thermomechanical properties of Sn–Ag–Cu solder materials at the nanoscale with the MEAM potential

Sn-Ag-Cu, commonly known as SAC, is considered to be among the most promising of all lead-free solder alloys. Research aimed at making electronic components smaller has pointed to the possible use of nanosized solder joints in the future. In this study, for the first time, molecular dynamics simulations were used to analyze the thermomechanical properties of SAC solder materials at the nanoscale. The modified embedded-atom method (MEAM) potential was utilized in the simulations of the SAC solder materials. The dimensions of the structures considered were 55 × 55 × 59Å. Four different SAC solders were studied, with Ag percentages ranging from 1% to 4% (SAC105, SAC205, SAC305, and SAC405). Thus, the effects of the Ag percentage on the thermomechanical properties of the solder at the nanoscale were identified. The impacts of the temperature on the uniaxial tensile properties and coefficient of thermal expansion (CTE) values of the SAC solder materials were investigated by performing simulations of the materials at different temperatures. Results suggest that as the Ag percentage increases, the uniaxial tensile strength and CTE of the solder increase whereas the failure strain and thermal conductivity decrease. The results presented should prove useful in the electronic packaging industry.

Novel flexible Ag nanoparticles doped on graphene – Ba2GaInO6 as cathode material for enhancement in the power conversion of DSSCs

In this study, we have demonstrated the first report on Ag nanoparticles doped on Graphene - Ba2GaInO6 (G-BGI@Ag), which was synthesized by a simple hydrothermal process for improving the counter electrode (CE) in dye-sensitized solar cells (DSSCs). Ag noble metallic nanoparticles can improve chemical and electronic properties by the localized surface Plasmon resonance effect. Therefore, the different atomic percentages of Ag (2–6 wt%) on G-BGI@Ag were studied. The 6% G-BGI@Ag showed an excellent power conversion efficiency (PCE) at 9.90%, which was similar to the Pt CE under the same conditions. The functional groups of G-BGI@Ag were also studied by use of the Boehm titration method. This was because of its enhancement to the adsorption properties and reactivity levels. Moreover, the positive synergistic effect between the BGI@Ag and graphene of the composite exhibited multifunctional characteristics of high photo activity, which could serve as a guideline in photovoltaic high-efficiency multifunctional devices.

Synthesis of silver nanoparticles using dialdehyde cellulose nanocrystal as a multi-functional agent and application to antibacterial paper

Development of a reliable and rapid process for synthesis of stable silver nanoparticles using nanocellulose is highly desired. In the present study, we report an efficient approach for the synthesis of stable silver nanoparticles (AgNPs) using dialdehyde cellulose nanocrystal (DACNC) as both reducing and stabilizing agent. The periodated cellulose nanocrystals (CNCs) were able to reduce silver ions to obtain cellulose nanocrystal–AgNPs (CNC–AgNPs) composites with high Ag percentage. The resulting composites were characterized by using UV–Vis spectroscopy, fourier infrared spectroscopy (FT-IR), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). Furthermore, their antimicrobial activities were investigated. The formation of AgNPs was evidenced by the surface plasmon resonance peak at around 400 nm. XRD data showed diffraction peaks at 2θ 38.33o, 44.55o, 64.27o, 77.66o, which can be indexed to (111), (200), (220), (311), and (222) planes of pure silver, indicating the successful synthesis of silver nanoparticles. The TEM images of CNC–AgNPs showed spherical AgNPs with sizes from several nanometers to 30 nm on the cellulose nanocrystal surfaces. The composites showed high antibacterial activities against Escherichia coli and Staphylococcus aureus. When the CNC–AgNPs was added into the pulp fibers, the obtained handsheets also displayed strong antibacterial activities with higher strength properties and a lower air permeability, indicating potential applications in food packaging materials.

Equilibrium and kinetic studies for silver removal from aqueous solution by hybrid hydrogels.

Hybrid hydrogels were prepared by blending Carboxymethyl chitosan (CMCts), Carboxymethyl cellulose (CMC) with Sodium sulfonate styrene (SSS) by 60-kGy gamma rays. The prepared hydrogels were utilized as silver-ion (Ag) sorbent under non- and competitive cases. Batch adsorption experiments were conducted in functional conditions including contact time, ratios of (CMC:CMCts) and SSS, pH value, temperature and adsorbent weight. Equilibrium contact time of 10 h. was obtained by the adsorption material. The optimal 4:2 ratio of (CMC:CMCts):SSS showed the Ag highest adsorption efficiency. The maximum percentage of Ag+ removal was achieved at the pH 5. The temperature effect on the adsorption ability of hybrid hydrogel indicated the Ag adsorption process was endothermic and spontaneous. The Langmuir isotherm model fitted Ag adsorption data well, assuming a monolayer adsorption with predicted maximum adsorption capacity of 451.74 × 10-3 mg. g-1. From the kinetic data, the process of Ag adsorption had higher agreement with the pseudo-2nd order model, predicting the amount of Ag+ uptake at different contact time intervals and at equilibrium.

The Contribution of MMP-7 Promoter Polymorphisms to Taiwan Lung Cancer Susceptibility.

Matrix metalloproteinase-7 (MMP-7) plays an important role in metastasis behavior of cancer cells, and overexpression of MMP-7 has been associated with poor prognosis in non-small cell lung cancer. However, the contribution of various genotypes of MMP-7 has not yet been investigated in lung cancer in Taiwan. Therefore, this study aimed to investigate the association of MMP-7 genotypes with lung cancer risk among the Taiwanese. In this hospital-based case-control study, genotypes and distributions at two promoter sites of MMP-7, A-181G and C-153T, were determined, and their association with lung cancer risk in Taiwan was evaluated among 358 lung cancer patients and 716 age- and gender-matched healthy control individuals. In addition, the interaction of MMP-7 genotypes and smoking status were also examined. The percentages of variant AG and GG at MMP-7 A-181G in the lung cancer group were similar to the control group (12.8% and 2.3% vs. 11.3% and 1.5%, respectively; ptrend=0.5294). The allelic frequency distribution analysis showed that the variant G allele at MMP-7 A-181G conferred non-significant elevated lung cancer risk compared to the wild-type A allele [odds ratio (OR)=1.18, 95% confidence interval (CI)=0.85-1.66, p=0.2289]. As for the genotypes of MMP-7 C-153T, all the studied Taiwanese population was of CC genotype. Furthermore, there was no obvious joint effect of MMP-7 A-181G genotype and smoking status on the lung cancer risk. No statistically significant correlation was observed between MMP-7 A-181G genotype distributions and gender. There was no evidence that the genotypes of MMP-7 A-181G may act as a biomarker in determining personal susceptibility to lung cancer in Taiwan.

The Contribution of MMP-7 Genotypes to Colorectal Cancer Susceptibility in Taiwan.

Matrix metalloproteinases (MMPs) play important roles in inflammation and carcinogenesis, but the genotypic role of MMP-7 has never been investigated in colorectal cancer (CRC) among the Taiwanese. Therefore, in this study we aimed to evaluate the contribution of MMP-7 genotypes to the risk of CRC in Taiwan. In this case-control study, MMP-7 A-181G and C-153T promoter genotypes were determined and their association with CRC risk were investigated among 362 CRC patients and 362 age- and gender-matched healthy controls. In addition, the interaction of MMP-7 genotypes and personal behaviors were also examined. The percentages of variant AG and GG for MMP-7 A-181G genotypes were 10.5% and 1.7% in the CRC group and 11.9% and 2.2% in the control group, respectively (p for trend=0.7145). The allelic frequency distribution analysis showed that the variant G allele of MMP-7 A-181G conferred a slight but non-significant decreased CRC susceptibility to the wild-type C allele (odds ratio (OR)=0.86, 95% confidence interval (CI)=0.64-1.31, p=0.37). Taiwanese all harbour the CC genotype at MMP-7 C-153T. As for the gene-lifestyle interaction, there were no obvious joint effects of MMP-7 A-181G genotype on the risk of CRC among ever smoker, alcohol drinker, non-smoker or non-drinker subgroups. No statistically significant correlation was observed between MMP-7 A-181G genotypic distributions and age, gender, tumor size, location or metastasis status. The genotypes of MMP-7 A-181G may play an indirect role in determining personal susceptibility to CRC and prognosis. The further genotyping work on MMP-7 and other genes (such as other MMPs, oncogenes and tumor suppression genes) on CRC susceptibility and prognosis, should be taken into consideration spontaneously in the precision medicine era.

Preparation of TiO&lt;SUB align="right"&gt;2 film on Ag and Al electrode for electrochemical bio-sensing application

In this present, work, titanium dioxide (TiO2) deposited on Ag and Al electrodes were fabricated by sol-gel chemical wet and dry (CWD) method to detect urea. The formation of the polycrystalline TiO2 deposited on Ag and Al substrates were confirmed by X-ray diffraction (XRD) analysis. The XRD analyses of both the samples clearly indicated that some percentage of Ag and Al diffuses into the TiO2 matrix at its interface region. The nature of I-V characteristics showed by the TiO2 on Ag and Al wire electrodes are found to be Ohmic and is perfect to be used for electrochemical sensor or bio-sensor at very low potential value. The performance and response to various concentrations of urea solution and pH level were experimentally studied by using TiO2 coated on Ag and Al as working electrodes with respect to Ag as reference electrode.

Exploring Ag-doped Mullite as High Dielectric and Antimicrobial Reinforcement with Polybenzoxazine Matrix

ABSTRACTThe present work describes the development of high k dielectric aluminosilicate and its application as reinforcement with polybenzoxazine matrix to achieve high dielectric and antimicrobial nanocomposite. Initially, dielectric constant value of mullite was found to increase with respect to the percentage of Ag in mullite lattices and reached a maximum of 14.9, when doped with 5 mol%. Data from antimicrobial assay also suggest that, the zone of inhibition expands with respect to embedding silver, and thus 10 mol% of Ag-doped mullite exhibiting the highest antimicrobial property. Since, 3 mol% Ag-doped mullite hold better dielectric, various weight percentages of the same (MA3) were embedded with polybenzoxazine matrices after its surface modification. Among the resulted nanocomposite, 1.5% of glycidyl-functionalized MA3/polybenzoxazine not only showed remarkable enhancement in their thermal, dielectric, electrical conductivity but also exhibited a zone of inhibition of 11 and 12 mm against Escherichia coli and Pseudomonas aeruginosa, respectively. The enhanced thermal, dielectric, and antimicrobial properties will make this material as a suitable candidate in printed circuit board application in particularly for cold weather climatic conditions.

Structural properties of electrodeposited Cu-Ag alloys

Cu-Ag alloys are promising materials for electrical interconnections due to their combination of high conductivity and superior mechanical strength. In the present work, Cu-Ag alloys were electrodeposited from a cyanide-free electrolytic bath and different Ag percentages, ranging from 3 to 15 at.%, were obtained by controlling the deposition conditions. Electrochemical processes occurring during Cu-Ag deposition were investigated by means of cyclic voltammetry. Structural properties were examined by TEM and XRD and hardness was assessed by microindentation. TEM observations revealed the presence of nano-sized Ag precipitates at low Ag content, and the composition of the Cu-rich and Ag-rich phases in high-Ag alloys was deduced from XRD measurements. As-deposited alloys exhibited high hardness values and the contribution of solid-solution hardening was highlighted.