ChemInform Abstract: SILVER NITRATE AND MERCURIC SALT MEDIATED CYCLIZATION OF Δ-ALLENIC ALCOHOLS. SYNTHESIS OF 2-α-ALKENYL TETRAHYDROPYRANS

1985 ◽  
Vol 16 (10) ◽  
Author(s):  
P. AUDIN ◽  
A. DOUTHEAU ◽  
J. GORE
Keyword(s):  
Author(s):  
K. Chien ◽  
R.C. Heusser ◽  
M.L. Jones ◽  
R.L. Van de Velde

Silver impregnation techniques have been used for the demonstration of the complex carbohydrates in electron microscopy. However, the silver stains were believed to be technically sensitive and time consumming to perform. Currently, due to the need to more specifically evaluate immune complex for localization in certain renal diseases, a simplified procedure in conjunction with the use of the microwave has been developed and applied to renal and other biopsies. The procedure is as follows:Preparation of silver methenamine solution:1. 15ml graduated, clear polystyrene centrifuge tube (Falcon, No. 2099) was rinsed once with distilled water.2. 3% hexamethylene tetramine (methenamine) was added into the centrifuge tube to the 6ml mark.3. 3% silver nitrate was added slowly to the methenamine to the 7ml mark while agitating. (Solution will instantly turn milky in color and then clear rapidly by mixing. No precipitate should be formed).4. 2% sodium borate was added to the solution to the 8ml mark, mixed and centrifuged before use.


2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.


2011 ◽  
Vol 4 (6) ◽  
pp. 1-8
Author(s):  
Ragia M Hegazy ◽  
◽  
Eman Farouk ◽  
Taghreed G Kharboush

2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Mai Ngọc Tuan Anh

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag\(^+\) ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1120G-1120
Author(s):  
J. L. Jacobs ◽  
C. T. Stephens

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.


2019 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Ariyetti Ariyetti ◽  
Muhammad Nasir ◽  
Safni Safni ◽  
Syukri Darajat

<p><em>Metil merah merupakan salah satu zat warna golongan azo yang sering digunakan dalam industri dan laboratorium. Penggunaan metil merah dapat menimbulkan efek terhadap kesehatan dan lingkungan. Oleh sebab itu dilakukan metode fotodegradasi dengan menggunakan semikonduktor dan radiasi sinar tampak. Semikonduktor yang digunakan yaitu berbahan dasar tembaga sulfat hidrat dan perak nitrat. Prekusor tembaga sulfat hidrat dibuat dari pengolahan limbah logam tembaga hasil pemotongan tembaga yang ada di bengkel Lembaga Ilmu Pengetahuan Indonesia (LIPI) Bandung. Bahan semikonduktor juga memiliki kemampuan dalam menghambat pertumbuhan bakteri. Hasil optimum yang didapatkan dalam proses fotodegradasi dan antibakteri merupakan gabungan antara kedua prekusor tembaga sulfat hidrat dan perak nitrat dengan bantuan penyinaran. Kemampuan dalam menghambat pertumbuhan bakteri didapatkan persentase kematian 100 % untuk masing-masing bakteri, yaitu Escherichia coli dan Staphylococcus aureus. Aktifitas fotokatalitiknya dengan konsentrasi semikonduktor 10 ppm untuk mendegradasi zat warna metil merah 5 ppm, selama 23 jam, dimana persentase degradasi yang didapatkan dengan penyinaran lebih tinggi dibandingkan dengan tanpa penyinaran. Pengaruh pH larutan terhadap degradasi metil merah yaitu optimum pada pH 12 (basa).</em></p><p><em><br /></em></p><p><em>Methyl red is one of the azo group dyes that is often used in industry and laboratories. The use of methyl red can have an effect on health and the environment. Therefore photodegradation method is done by using semiconductor and visible light radiation. The semiconductor used is based on copper sulfate hydrate and silver nitrate. The copper sulphate hydrate precursor is made from the processing of copper-cut copper metal waste in the workshop of the Indonesian Institute of Sciences (LIPI) in Bandung. Semiconductor materials also have the ability to inhibit bacterial growth. The optimum results obtained in the photodegradation and antibacterial process are a combination of both copper sulfate hydrate precursor and silver nitrate with the help of irradiation. The ability to inhibit bacterial growth obtained 100% mortality for each bacterium, namely Escherichia coli and Staphylococcus aureus. Photocatalytic activity with 10 ppm semiconductor concentration to degrade methyl red dye 5 ppm, for 23 hours, where the percentage of degradation obtained by irradiation is higher than without irradiation. The effect of pH of the solution on the degradation of methyl red is optimum at pH 12 (base).</em></p>


Sign in / Sign up

Export Citation Format

Share Document