Application of silver nitrate colorimetric method to non-steady-state diffusion test

NT build 443, or profile fitting method, is often used to measure the diffusion coefficient of chloride in concrete. However, this method is quite laborious and needs special equipment. Colorimetric method is a quick and simple method to measure the penetration depth of chloride by spraying 0.1 mol/L silver nitrate solution. The objective of this work is to study the possibility of the use of colorimetric method in the calculation of non-steady-state diffusion coefficient. Twelve concrete mixtures with different supplementary cementitious materials and water-to-cement ratios of 0.35, 0.48 and 0.6 were used for study. According to NT build 443, the concrete specimens were immersed in 165 g/L NaC1 （2.8 mol/L） solution for 42 d. Both water-soluble （convert to free chloride） chloride and acid-soluble chloride at different layers of specimens were measured. The results show that the mean value of free chloride concentration at the color change boundary Cd was 0.306 mol/L. The surface free chloride concentration cs was obtained by profile fitting method, which was 40% lower than the chloride concentration of exposure solution after an immersion period of 42 d. Chloride diffusion coefficients obtained by the colorimetric method was not well correlated with those obtained by profile fitting method.

OXIDATIVE DEGRADATION OF BILIVERDIN AND BILIRUBIN ESTERS IN PRESENCE OF SILVER NITRATE

Treatment of biliverdin IXα dimethyl ester(2)with silver nitrate in alkaline solution gave two violin-like tripyrrione carbaldehydes,one de- graded at C15-C16,other at C4-C5.Biliverdin IXα(1),bilirubin IXα(3)and its dimethyl ester(4)gave the same results.

Role of Silver Nitrate on in Vitro Flowering and Shoot Regeneration of Solanum nigrum (L.)—An Important Multipurpose Medicinal Plant

Silver nitrate induced MS media enhanced multiple shoot regeneration and in vitro flowering from axillary bud and leaf explants of Solanum nigrum (L.) an important antiulcer medicinal plant. Healthy axillary bud and leaf explants were inoculated on MS medium supplemented with BAP/Kn (1.0 - 2.0 mg/l) in combination with IAA/NAA (0.5 mg/l) and AgNO3 (0.1 - 1.0 mg/l). The explants were responded effectively and good regeneration frequencies were observed in all the combinations of silver nitrate tested when compared to control. Maximum number of multiple shoots (34.3) was found in leaf explants cultured on MS media supplemented with BAP (2.0 mg/l), NAA (0.5 mg/l) and AgNO3 (0.4 mg/l). These regenerated shoots were sub-cultured on to the flowering media. Maximum number of in vitro flowers (12) was obtained from axillary bud explants in BAP (2.0 mg/l), Kn (1.0 mg/l), IAA (0.5 mg/l) and AgNO3 (6.0 mg/l) supplemented media when compared to leaf (4) and control. All the in vitro raised shoots were transferred to rooting medium supplemented with NAA, IBA (1.0 - 2.0 mg/l) and AgNO3 (0.1 - 0.6 mg/l). The best rooting response (24.6) was observed in 2.0 mg/l IBA + 0.4 mg/l AgNO3. The well rooted plantlets were transferred to polybags containing soil + vermiculate in 1:1 ratio for hardening and finally the hardened plantlets were transferred to field conditions.

Influence of Ethylene Inhibitor Silver Nitrate on Direct Shoot Regeneration from in Vitro Raised Shoot Tip Explants of Sphaeranthus indicus Linn.—An Important Antijaundice Medicinal Plant

In the present investigation, an attempt has been made to study the influence of ethylene inhibitor silver nitrate on direct shoot regeneration in Sphaeranthus indicus, an important antijaundice medicinal plant, by using in vitro raised shoot tip explants. The effect of various concentrations of kinetin, BAP (0.5 - 3.0 mg/l), and NAA (0.1 - 0.5 mg/l) along with AgNO3 (0.1 - 1.0 mg/l) was studied. Among the combinations tested MS medium augmented with kinetin (1.0 mg/l), NAA (0.1 mg/l) and AgNO3 (0.4 mg/l) was found to be optimum for production of multiple shoots (34.3 ± 0.36). Addition of AgNO3 to the media not only increases shoot number in all the concentrations tested but also shoot length. AgNO3 at the concentration of 0.4 mg/l produced 35% more number of multiple shoots when compared to multiple shoots (10.8 ± 0.12) produced in control. In the present study by the addition of ethylene inhibitor silver nitrate and growth regulators, more number of multiple shoots (three folds) and shoot length was observed compared to control. These in vitro raised shoots were transferred to the rooting medium containing different concentrations of auxins such as NAA and IAA along with AgNO3 (0.1 - 0.6 mg/l). Better rooting response (21.6) was observed on NAA (2.0 mg/l) and AgNO3 (0.4 mg/l) containing media. The healthy rooted plantlets were transferred to polybags containing soil and vermiculate in 1:1 ratio for hardening. Finally the hardened plants were transferred to field environment for utmost survivability.

Assessment of the Presence of Chlorides in Mortar through the Silver Nitrate Colorimetric Spraying Method

This study aims to evaluate the presence of free chlorides by the silver nitrate colorimetric spraying method in mortars made with Portland cement CP II Z-32. In order to make an assessment beyond the qualitative analysis, a calculation of the contaminated areas by free chlorides was performed by measuring the regions using a computer image analysis software （IMAGEJ）. The experimental part of the research involved samples of 5 cm x 10 cm of mortar and 0.1 M solution of silver nitrate in distilled water. The mortar samples were made with cement CP II Z-32 with the following concentrations of chloride incorporated into the mixing water： 0%0, 0.4%, 0.6%, 0.8%, 1.0% and 2.0%, in relation to the mass of cement, totaling 108 samples. The average of percentage results from the contaminated area of the series of samples was respectively 0%, 14.9694%, 19.7444%, 46.0239%, 62.3311% and 96.0083% in relation to the total area, concluding that the method of silver nitrate spraying is applicable and that the white color indicates the presence of chloride ions and other possible aggressive salts to the structure or the concrete.

Antimicrobial Activity, Structural, Crystallographic and Thermal Characteristics of Alpha-Titanium Phosphate Promoted by Silver Ions

The recent global spread of the pandemic underscores the necessity of seeking new materials effective against microorganisms. Nanotechnology offers avenues for developing multifunctional materials. In this study, alpha-titanium phosphate (α-TiP) nanoparticles were synthesized and treated with silver salt to enhance their antimicrobial properties. The physicochemical characteristics and antimicrobial activity were evaluated. It was revealed by X-ray diffraction analysis that the structural integrity of α-TiP was influenced by ethylenediamine and silver ions. Distinct degradation profiles for each chemical modification were shown by thermogravimetric analysis. Infrared spectroscopy detected shifts and new absorption peaks in the spectra depending on the type of modification. Energy dispersive spectroscopy confirmed the disaggregation of α-TiP galleries following the addition of silver salt, which increased their effectiveness against microorganisms. Notably, only the sample treated with silver ions exhibited antimicrobial action. Antimicrobial activity was tested against the bacteria of medical importance Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria momocytogenes and the yeast Candida albicans. All microorganisms were inhibited by sample containing silver. Minor inhibition was observed against the Gram-positive bacteria L. monocytogenes and Bacillus cereus, while the greatest inhibition occurred against the fungus (yeast) C. albicans. The results revealed a potential application of the nanoparticles for control of microorganisms in public health.

Silver nitrate restores susceptibility of clinical multidrug resistant gram-negative and gram-positive bacteria to amikacin in vitro

Silver nitrate could inhibit the clinical multidrug resistant isolates at high concentrations（with minimal inhibitory concentrations（MICs） from 32 μM to 64 μM）. The activities of amikacin in the presence of sub-lethal silver nitrate（15 μM） were tested for the combinational effects against multidrug resistant clinical isolates in vitro. Silver nitrate restored the susceptibility of drug-resistant Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus to amikacin. It lowered the MICs of amikacin from 〉128 μg/mL to（2–16） μg/mL and 32 μg/mL, respectively, and lowered the MICs of amikacin on extended spectrum β-lactamase-producing Pseudomonas aeruginosa and Escherichia coli from（16–32） μg/mL and 16 μg/mL to（〈1–4） μg/mL and 〈1 μg/mL, respectively.

Modulation of Sex Expression in Four Forms of Watermelon by Gibberellin, Ethephone and Silver Nitrate

There has been no systematic research on the effect of plant growth regulators and silver nitrate treatments on the control of sex expression in watermelon. In this study, we tested sex expression responses of four watermelon forms(monoecism, gynoecism, andromonoecism,and hermaphrodite) to gibberellin, ethephon and silver nitrate treatments. Results have shown that, in monoecious plants, gibberellins(GA_3)and ethephon treatments reduced the percentage of female flowers and delayed the occurrence of the first female flower, while silver nitrate induced the formation of bisexual flowers. In gynoecious plants, both ethephon and silver nitrate treatments transformed some female flowers into bisexual flowers, and treatment with ethephon resulted in a mass of abnormal flowers, while no obvious effect of treatment with GA_3 was observed. In andromonoecious plants, ethephon and GA_3 treatments delayed the occurrence of the first bisexual flower, and GA_3 reduced the percentage of bisexual flowers, while no distinct effect for silver nitrate treatment was observed. In hermaphroditic plants, ethephon treatment induced the appearance of numerous abnormal flowers, while no obvious effects for GA_3 and silver nitrate treatments were observed.We analyzed the transcription levels of all the expressed aminocyclopropane-1-carboxylic acid synthase(ACS) homologues in two gynoecious mutants and their wild types. We also tested the gene expression of CitACS4 which had been recognized as the andromonoecious gene in all treatments. All these results suggested that the best masculinizing treatment for breeding of the gynoecious line is silver nitrate, which repressed the expression of CitACS4 and induced many bisexual flowers for use in self-fertilization subsequently.

Hydrothermal Synthesis and X-ray Characterization of Silver(I) Complex:Diacetylthiocarbamide Silver(I) Nitrate, [Ag(CH_3CONHC(S)NH_2)_2](NO_3)

The title compound [Ag(CH3CONHC(S)NH2)2](NO3) has been prepared by hydrothermal synthesis and characterized by single-crystal X-ray diffraction. It crystallizes in mo-noclinic, space group P21/c with Mr = 406.20 (C6H12Ag N5O5S2), a = 12.0680(6), b = 6.8056(5), c = 18.0173(1) ? b = 111.383(4), V = 1377.9(2) 3, Z = 4, Dc = 1.958 g/cm3 , F(000) = 808, = 1.789 mm-1, R = 0.0361 and wR = 0.1015. Of 4185 reflections ((2)max = 55.00?, 3147 were unique (Rint = 0.0174) and 2820 with I > 2(I) were used to solve the structure. The silver(I) atom adopts V-shape geometry with the AgS bond distance of 2.4271(7) and 2.7229(9) , respectively. Seven atoms of one acetylthiocarbamide ligand are coplanar, while only four atoms of another acetylthio-carbamide ligand are fairly planar. The [Ag(CH3CONHC(S)NH2)2]+ cation and nitrate anion NO3- are connected by hydrogen bonds to form a three dimensional hydrogen bonding network..

Preparation, characterization, and antibacterial activity of γ-irradiated silver nanoparticles in aqueous gelatin

Colloidal silver nanoparticles （Ag-NPs） were obtained through γ-irradiation of aqueous solutions containing AgNO3 and gelatin as a silver source and stabilizer, respectively. The absorbed dose of γ-irradiation influences the particle diameter of the Ag-NPs, as evidenced from surface plasmon resonance （SPR） and transmission electron microscopy （TEM） images. When the γ-irradiation dose was increased （from 2 to 50 kGy）, the mean particle size was decreased continuously as a result of γ-induced Ag-NPs fragmentation. The antibacterial properties of the Ag-NPs were tested against Methicillinresistant Staphylococcus aureus （MRSA） （Gram-positive） and Pseudomonas aeruginosa （P.a） （Gram-negative） bacteria. This approach reveals that the γ-irradiation-mediated method is a promising simple route for synthesizing highly stable Ag-NPs in aqueous solutions with good antibacterial properties for different applications.

Comparison of Antioxidant Activities of Silver Nanoparticles and Methanol Extracts of Three Indigenous Nigeria Herbal Seeds

The antioxidant of seeds was carried out using extracts from methanol and Silver Nanoparticles from the spice. The SEM shows the shapes, dispersion and agglomeration of the sample, while the EDX confirms the SEM and the presence of some compounds. The FT-IR reveals the AgNPs capping and reducing the particular biomolecule from the functional group for identification. Compounds found in the FT-IR seeds of Capsicum annum are Ag L (Silver iodide), C K (Cyanogen chloride), P K (Phenol). Monodora myristica are Mo L (Molybdenum), Ag L (Silver iodide), C K (Cyanogen chloride), P K (Phenol), Mg K (Magnesium). Piper guineense are Ag L (Silver iodide), Ci K (Potassium chloride), C K (Cyanogen chloride), P K (Phenol). The seeds show that the AgNPS of CA and MM has a better antioxidant activity than the methanol of CA and MM, while the PG methanol has a better activity than the AgNPS PG. The control (Catechin and Galic acid) has a slight overall better DPPH activity than the AgNPS. It is important to note that there is a concentration dependency in CA, MM AgNPS, PG methanol respectively. Notably, at CA methanol, the conc. at 125 was higher than the conc. at 250. Hence, there is need to create a great part in using plant samples for making tabulated or capsulated drugs for treatment of diseases and using plant silver nanoparticles to develop a healthy food/drug preservative package material “smart packaging” that will enhance shelf-life.

Zinc and Silver Salts-Containing Lamellar Titanium Phosphate: A Multifunctional Filler

Zinc and silver compounds have been studied because they have ultraviolet light barrier properties and bactericidal action, respectively. Materials with multifunctional characteristics have been sought to produce polymeric nanocomposites. In this work, the chemical modification of titanium phosphate (TiP) was carried out through a route with successive intercalations. TiP was synthesized and consecutively pre-expanded with ethylamine and pyromellitic acid. Then it was modified with zinc acetate and silver nitrate. The final product was characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, wide-angle X-ray diffractometry, field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and thermogravimetry. Infrared revealed dislocation and appearance of bands according to the intercalating agent. Inorganic salts interfered in the crystallization and melting processes of pyromellitic acid. Vanishing of the TiP hkl plane and variation and appearance of new crystallographic planes at low diffraction angles induced intercalation. SEM showed agglomerated structures. New thermal degradation events at higher temperatures endorsed the formation of zinc and silver carboxylate salts. We concluded that a new miscellaneous and multifunctional matter was achieved.

ESTABLISHMENT OF DIFFERENTIAL DISPLAY mRNA AND ITS APPLICATION IN THE STUDY ON THE MECHANISM OF LUNG CANCER INDUCED BY RADIATION

Objective: A method for separating mRNAs by means of the polymerase chain reaction (differential display mRNA), and identifying the genes related to radiation-induced lung cancer was introduced. Methods: The RNAs were isolated from two pairs of samples, SV40-immortalized human fetal tracheal fibroblast cell (SHTF) versus αSHTF cell (transformed SHTF cell induced by α particles) and lung cancer tissue versus normal lung tissue obtained from one miner, and amplified by RTPCR. The differential expressed gene fragments were displayed by autoradiograph or silver nitrate stain. Results: The differential display mRNA method was established using both cell and tissue samples. The bands stained by silver nitrate were clearer than those on X-ray film. The rate of reamplification of differentially expressed gene fragments stained by silver nitrate is 80%, higher than that by autoradiograph, 50%. Conclusion: Differential display mRNA method was established successfully on both cell and tissue samples. The modified method for staining band increased the rate of reamplification and established the basis for confirming relative genes.

Media Appraisal for Somatic Embryogenesis of Elite Inbred Lines of Maize

Several protocols have been published for somatic embryogenesis in maize. It is essential to compare different protocols on selected germplasm at initial stages of tissue culture to identify a protocol that would yield optimum results. The ultimate goal is to use in vitro system for selecting and generating stress tolerant maize germplasm. Immature embryos of the elite inbred lines of maize （87014 ×Z28-11 and POP43SRS5-57） were cultured on three different semi-solid media （0.5% agar） and the effectiveness of the media for somatic embryogenesis assessed over a period two weeks of sub-culturing. A significant difference was observed among the media in proportion of potentially embryogenic calli and callus cluster size at 1 and 2 weeks after culturing. N6 medium supplemented with casaminoacid （100 mg/L）, 2, 4-dichlorophenoxy acetic acid （1 mg/L）, L-proline （25 mM） and sucrose （2%）, and Murashige and Skoog （MS） medium supplemented with 2, 4-D （2 mg/L） and sucrose （3%） gave higher proportion of potentially embryogenic calli and callus size than MS medium supplemented with casaminoacids （100 mg/L）, 2, 4-D （2 mg/L）, abscissic acid （3.3μM）, and silver nitrate （195 μM） and sucrose （3%）. The difference between genotypes is not significant

Silver impregnated carbon for adsorption and desorption of elemental mercury vapors

The Hg 0 vapor adsorption experimental results on a novel sorbent obtained by impregnating a commercially available activated carbon （Darco G60 from BDH） with silver nitrate were reported.The study was performed by using a fundamental approach,in an apparatus at laboratory scale in which a synthetic flue gas,formed by Hg 0 vapors in a nitrogen gas stream,at a given temperature and mercury concentration,was flowed through a fixed bed of adsorbent material.Breakthrough curves and adsorption isotherms were obtained for bed temperatures of 90,120 and 150°C and for Hg 0 concentrations in the gas varying in the range of 0.8–5.0 mg/m 3 .The experimental gas-solid equilibrium data were used to evaluate the Langmuir parameters and the heat of adsorption.The experimental results showed that silver impregnated carbon was very effective to capture elemental mercury and the amount of mercury adsorbed by the carbon decreased as the bed temperature increased.In addition,to evaluate the possibility of adsorbent recovery,desorption was also studied.Desorption runs showed that both the adsorbing material and the mercury could be easily recovered,since at the end of desorption the residue on solid was almost negligible.The material balance on mercury and the constitutive equations of the adsorption phenomenon were integrated,leading to the evaluation of only one kinetic parameter which fits well both the experimentally determined breakthrough and desorption curves.

Silver(I)-mediated reaction of trimethylsilylated arylacetylenes with sulfonyl chlorides:Unexpected formation of vinvl sulfones

A novel reaction of trimethylsilylated arylacetylenes with sulfonyl chlorides was performed in the presence of silver nitrate or triflate. Conjugated vinyl sulfones as dramatic products were obtained in moderate yields and with Z-selectivity. A free radical mechanism has been proposed to account for the formation of the products.

Effective parameter study for the facile and controlled growth of silver molybdate nano/micro rods

Controlled growth of nano/micro structures by controlling the effective parameters is the basic requirement for the application point of view in various areas. Here we report the facile growth of silver molybdate nanolmicro rods by mixing the solution of silver nitrate and ammonium molybdate at ambient condition followed by hydrothermal treatment at various temperatures for 12 h. To achieve the goal for the synthesis of long, high yield and homogeneous nanorods various effective parameters have been studied to set the most effective conditions for the growth. Among possible effective parameters first the temperature of the furnace was set by warring the temperature and then at the set temperature the concentration of reactants （NH4）6Mo7O24 and silver nitrate are varied respect to each other. The pH and temperature values were monitored during the mixing of the reactants. Structurallmicrostructural characterization revealed the optimum condition of 150℃ of the furnace and the concentration of （NH4）sMo7O24 and silver nitrate as described in various tables.

Fabrication of silver nanoparticles decorated anodic aluminum oxide as the SERS substrate for the detection of pesticide thiram

An efficient surface-enhanced Raman scattering(SERS) substrate is developed based on silver nanoparticles decorated anodic aluminum oxide(Ag/AAO).The AAO templates were fabricated using a two-step anodization approach,and silver nanoparticles(Ag NPs) were obtained by thermal decomposition of Ag nitrate in AAO.The structure of Ag/AAO hybrid substrate is characterized by scanning electron microscopy(SEM).The results show that the as-prepared SERS substrates consist of high-density Ag NPs with sizes of tens of nanometers.The Ag NPs are adsorbed on the surface of AAO template in the form of network structure which is called "hot spot".The SERS enhancement ability of the nanostructure is verified using thiram as probing molecules.The limit of detection is as low as 1×10-9 mol/L.The results indicate that the as-prepared substrate possesses excellent SERS sensitivity,high stability and uniformity enhancement.

Efficient Synthesis of Isoquinolines by AgNO3-Catalyzed Sequential Imination-Annulation of 2-Alkynyl Aldehydes with Ammonium Bicarbonate

An operationally simple approach for the tandem synthesis of isoquinolines by the reaction of o-alkynylalde- hydes with ammonium bicarbonate via Ag-catalyzed 6-endo-dig ring closure is described. The reaction conditions and the scope of the reaction are examined, and a variety of substituted isoquinolines are prepared in moderate to excellent yields.

Determining the hospital cost of anterior epistaxis treatment modalities at a Canadian tertiary care centre

Objective:To estimate the hospital costs of managing anterior epistaxis in the Emergency Department at a Tertiary Care centre in Canada.Material and methods:A cost analysis was conducted based on a retrospective review of Emergency Department visits from January 2012 to May 2014.A consecutive sample of adult patients with a diagnosis of anterior epistaxis was included.Anterior epistaxis was managed via one of:Nasal clip,Merocel(R),Silver Nitrate cautery,Vaseline packing,other treatment or no treatment.Both the direct and indirect hospital costs(SCDN)for anterior epistaxis treatment were calculated from the hospital's perspective.Generalized linear models were used to assess the association between treatment modalities and total hospital costs while controlling for potential confounding factors.Results:Three hundred and fifty-three patients(49%female)with a mean age of(69.9±18.5)years were included in the analysis.The median(interquartile ranges)costs of treatment ranged from CS227.83(CS167.96,CS328.69)for observation to CS763.98(CS632.25,CS830.23)for Merocel(R).The overall median total hospital costs incurred across all modalities was CS566.24(CS459.61,CS753.46)for the management of anterior epistaxis.Silver Nitrate,nasal clip,and observation were statistically associated with a lower cost when compared to Merocel(R)(P<0.001)even after potential confounding factors were controlled.Conclusions:Our results show wide difference in the hospital cost of epistaxis across treatment modalities.These cost estimates can help inform future economic evaluation studies aiming to guide the allocation of health care resources for patients with epistaxis.