scholarly journals Ichthyotoxicity and Rotenone Stability of Derris trifoliata (Leguminosae) Acetone Formulations

2007 ◽  
Vol 19 (4) ◽  
Author(s):  
F.C. SUMERA ◽  
M.T. CONATO
Keyword(s):  
Oreochromis Niloticus ◽  
Chromatographic Analysis ◽  
Chloroform Extract ◽  
Acetone Extract ◽  
Ambient Conditions ◽  
Rapid Degradation ◽  
Fish Toxicity ◽  
Fishpond Management ◽  
The Stability ◽  
New Formulation

The stability of the acetone extract of Derris trifoliata (as a more accessible piscicide for fishpond management) was compared with those of Derris elliptica (Leguminosae) for a duration of seven months with respect to toxicity and rotenone content to Oreochromis niloticus (Cichlidae). Extract formulation of D. elliptica was found to retain its fish toxicity throughout the duration of the experiment without exposure to sunlight while that of D. trifoliata was found to decrease after only about a month. The toxicity of D. trifoliata and D. elliptica formulations were maintained longer, when their extracts were refrigerated at around 9 – 10o C. Chromatographic analysis (HPLC) revealed that although fish toxicity is maintained, rotenone concentration continued to decrease in D. elliptica extracts much faster at conditions where the extracts were exposed to sunlight than if kept in a refrigerator or simply kept inside a room at ambient conditions. However, for the D. trifoliata extract, not much difference was found if it was kept exposed or not to sunlight, as the rotenone concentration in both conditions continued to drop. Placing the extract at 9 – 10o C in a refrigerator prevented this rapid degradation of rotenone. A better way of preventing the toxicity to decrease and the rotenone to degrade was by partitioning the acetone extract between chloroform and water, taking the chloroform extract, evaporating, collecting and reformulating it when needed. This new formulation showed better rotenone stability and consistent toxicity throughout the seven months of experimental observation.

scholarly journals Stability of tilapia Minced (Oreochromis niloticus) due to the use of different additives

2013 ◽  
Vol 3 (1) ◽  
pp. 44
Author(s):  
Ingridy Simone Ribeiro Cabral ◽  
Maria Fernanda Calil Angelini ◽  
Ligianne Din Shirahigue ◽  
Lia Ferraz de Arruda Sucasas ◽  
Marília Oetterer
Keyword(s):  
Oreochromis Niloticus ◽  
Storage Time ◽  
Sodium Tripolyphosphate ◽  
Extraction Process ◽  
Font Size ◽  
Lower Stability ◽  
Technological Quality ◽  
The Stability ◽  
New Formulation

<span style="font-family: Times New Roman; font-size: small;"> </span><p class="MsoNormal" style="margin: 0cm 0cm 0pt; text-align: justify; line-height: 200%;">The application of minced extraction process is an emergent and attractive process due to its possibility of greater meat recovering, creating better quality products. The development of new formulation is necessary to improve the technological quality of minced, and can be achieved through the use of preservative ingredients. The aim of this study was to evaluate the effect of washing and use of additives such as BHT and the association sodium tripolyphosphate / sodium erythorbate, on the stability of tilapia minced stored at frozen until 60 days. Minced was prepared from tilapia with addition of different antioxidants, and its composition and freshness characteristics (TVB-N and TBARS) were evaluated. It was observed that the non-washed minced presented lower moisture but higher levels of proteins, lipids and ash. After the freshness analysis, the washed minced TVB-N showed lower values than non-washed, and the samples with antioxidants presented higher stability during storage. The TBARS analysis of cooked samples showed a lower stability and it was verified that the storage time tends to increase the oxidation. It was concluded that both washing and addition of antioxidants were able to enhance stability against minced storage under freezing.</p><p class="MsoNormal" style="margin: 0cm 0cm 0pt; text-align: justify; line-height: 200%;">&nbsp;</p><p class="MsoNormal" style="margin: 0cm 0cm 0pt; text-align: justify; line-height: 200%;">DOI: http://dx.doi.org/10.14685/rebrapa.v3i1.85</p><span style="font-family: Times New Roman; font-size: small;"> </span>

Structure, Stability and Water Adsorption on Ultra-Thin TiO2 Supported on TiN

2019 ◽  
Author(s):  
Jose Julio Gutierrez Moreno ◽  
Marco Fronzi ◽  
Pierre Lovera ◽  
alan O'Riordan ◽  
Mike J Ford ◽  
...  
Keyword(s):  
Density Functional ◽  
Water Adsorption ◽  
Chemical Potential ◽  
Energy Gap ◽  
Molecular Water ◽  
Structure Stability ◽  
Ambient Conditions ◽  
Rutile Structure ◽  
The Stability ◽  
The One

<p></p><p>Interfacial metal-oxide systems with ultrathin oxide layers are of high interest for their use in catalysis. In this study, we present a density functional theory (DFT) investigation of the structure of ultrathin rutile layers (one and two TiO<sub>2</sub> layers) supported on TiN and the stability of water on these interfacial structures. The rutile layers are stabilized on the TiN surface through the formation of interfacial Ti–O bonds. Charge transfer from the TiN substrate leads to the formation of reduced Ti<sup>3+</sup> cations in TiO<sub>2.</sub> The structure of the one-layer oxide slab is strongly distorted at the interface, while the thicker TiO<sub>2</sub> layer preserves the rutile structure. The energy cost for the formation of a single O vacancy in the one-layer oxide slab is only 0.5 eV with respect to the ideal interface. For the two-layer oxide slab, the introduction of several vacancies in an already non-stoichiometric system becomes progressively more favourable, which indicates the stability of the highly non-stoichiometric interfaces. Isolated water molecules dissociate when adsorbed at the TiO<sub>2</sub> layers. At higher coverages the preference is for molecular water adsorption. Our ab initio thermodynamics calculations show the fully water covered stoichiometric models as the most stable structure at typical ambient conditions. Interfacial models with multiple vacancies are most stable at low (reducing) oxygen chemical potential values. A water monolayer adsorbs dissociatively on the highly distorted 2-layer TiO<sub>1.75</sub>-TiN interface, where the Ti<sup>3+</sup> states lying above the top of the valence band contribute to a significant reduction of the energy gap compared to the stoichiometric TiO<sub>2</sub>-TiN model. Our results provide a guide for the design of novel interfacial systems containing ultrathin TiO<sub>2</sub> with potential application as photocatalytic water splitting devices.</p><p></p>

Biochemical Composition, Antibacterial and Anti-Biofilm Activities of Indian Medicinal Plants

2020 ◽  
Vol 18 ◽  
Author(s):  
Mulugeta Mulat ◽  
Fazlurrahman Khan ◽  
Archana Pandita
Keyword(s):  
Antibacterial Activity ◽  
Medicinal Plants ◽  
Pathogenic Bacteria ◽  
Chemical Constituents ◽  
Multidrug Resistant ◽  
Chloroform Extract ◽  
Acetone Extract ◽  
Biologically Active ◽  
Ocimum Sanctum ◽  
Agar Disc

Background: Medicinal plants have been used for treatments of various health ailments and the practices as a remedial back to thousands of years. Currently, plant-derived compounds used as alternative ways of treatment for multidrug-resistant pathogens. Objective: In the present study, various parts of six medical plants such as Solanum nigrum, Azadirachta indica, Vitex negundo, Mentha arvensis, Gloriosa superba, and Ocimum sanctum were extracted for obtaining biological active constituents. Methods: Soxhlet method of extraction was used for obtaining crude extracts. Agar disc diffusion and 96-well plate spectroscopic reading were used to detect the extract’s antibacterial and antibiofilm properties. Results: The obtained extracts were tested for antimicrobial and antibiofilm properties at 25 mg/mL concentrations. Maximum antibacterial activity was observed in O. sanctum chloroform extract (TUCE) against Staphylococcus aureus (24.33±1.52 mm), S. nigrum acetone extract (MAAC) against Salmonella Typhimurium (12.6 ± 1.5 mm) and Pseudomonas aeruginosa (15.0 ±2.0 mm). Only TUCE exhibited antibacterial activity at least a minimum inhibitory concentration of 0.781 mg/mL. Better antibiofilm activities were also exhibited by petroleum extracts of G. superba (KAPE) and S. nigrum (MAPE) against Escherichia coli, S. Typhimurium, P. aeruginosa and S. aureus. Moreover, S. nigrum acetone extract (MAAC) and O. sanctum chloroform extract (TUCE) were showed anti-swarming activity with a reduction of motility 56.3% against P. aeruginosa and 37.2% against S. aureus. MAAC also inhibits Las A activity (63.3% reduction) in P. aeruginosa. Conclusion: Extracts of TUCE, MAAC, MAPE, and KAPE were exhibited antibacterial and antibiofilm properties against the Gram-positive and Gram-negative pathogenic bacteria. GCMS identified chemical constituents are responsible for being biologically active.

scholarly journals Clinical Application and Efficacy of Silver Drug in Ophthalmology: A Literature Review and New Formulation of EYE Drops with Drug Silver (I) Complex of Metronidazole with Improved Dosage Form

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 210
Author(s):  
Arleta Waszczykowska ◽  
Dominik Żyro ◽  
Justyn Ochocki ◽  
Piotr Jurowski
Keyword(s):  
Dosage Form ◽  
Complex Analysis ◽  
Bacterial Resistance ◽  
Eye Drops ◽  
Ophthalmic Diseases ◽  
The Stability ◽  
New Formulation ◽  
Additional Therapy ◽  
Antibacterial Potential

The use of silver preparations in medicine is becoming increasingly popular. The basic aim of this evaluation was to review the literature on the clinical (in vivo) and antibacterial potential of silver preparations in ophthalmic diseases. The second goal was to summarize the results of experimental research on the use of silver preparations in ophthalmology. The third objective was to present a method for stabilizing eye drops containing silver (I) complex. Analysis of the pH stability of the silver (I) complex with metronidazole in the prepared dosage form (eye drops) was carried out. Most silver preparations are clinically used for topical application. Few experimental results indicate the usefulness of intraocular or systemic administration of silver (I) preparations as an alternative or additional therapy in infectious and angiogenic eye diseases. The development of a new formulation increases the stability of the dosage form. New forms of silver (I) products will certainly find application in the treatment of many ophthalmic diseases. One of the most important features of the silver (I) complex is its capacity to break down bacterial resistance. The new eye drops formula can significantly improve comfort of use. Due to their chemical nature, silver (I) compounds are difficult to stabilize, especially in the finished dosage form.

scholarly journals Tetrabutylammonium cations for moisture-resistant and semitransparent perovskite solar cells

2017 ◽  
Vol 5 (42) ◽  
pp. 22325-22333 ◽  
Author(s):  
Isabella Poli ◽  
Salvador Eslava ◽  
Petra Cameron
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Ambient Conditions ◽  
The Stability ◽  
Moisture Resistant

Tetra-butylammonium cations have been partially substituted for methylammonium cations in perovskite thin films. The stability of devices stored under ambient conditions was enhanced by the presence of TBA and cells with high mol% TBA were found to have reasonable efficiencies while being semi-transparent.

Studies on Polyaniline: Polyethyleneterephthalate Films

2006 ◽  
Vol 111 ◽  
pp. 99-102 ◽  
Author(s):  
A.A. Ahmed ◽  
Faiz Mohammad
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Arrhenius Equation ◽  
Great Increase ◽  
Thermooxidative Stability ◽  
Ambient Conditions ◽  
Dc Electrical Conductivity ◽  
The Stability ◽  
Almost All ◽  
Conductivity Retention

The films of polyaniline:polyethyleneterephthalate films were prepared by polymerizing aniline soaked in polyethyleneterephthalate films of different thicknesses. The films were characterized by FTIR as well as for their electrical properties. The electrical properties of the films were observed to be of good quality as almost all the films showed a great increase in their electrical conductivity from insulator to semiconductor region after doping with hydrochloric acid. All the films in their doped state follow the Arrhenius equation for the temperature dependence of electrical conductivity from 35 to 115oC. The thermooxidative stability was studied by thermogravimetry and differential thermal analysis. The stability in terms of dc electrical conductivity retention was also studied under ambient conditions by two slightly different techniques viz. isothermal and cyclic techniques. The dc electrical conductivity of the films was found to be stable below 90oC for all the films under ambient conditions.

scholarly journals Schéma SRNHS Analyse et Application d'un schéma aux volumes finis dédié aux systèmes non homogènes

2006 ◽  
Vol Volume 5, Special Issue TAM... ◽  
Author(s):  
Slah SAHMIM ◽  
Fayssal Benkhaldoun
Keyword(s):  
Shallow Water ◽  
Scalar Case ◽  
Finite Volume Scheme ◽  
Two Phase ◽  
Homogeneous Systems ◽  
Selfsimilar Solution ◽  
International Audience ◽  
The Stability ◽  
New Formulation ◽  
Water Problems

International audience This article is devoted to the analysis, and improvement of a finite volume scheme proposed recently for a class of non homogeneous systems. We consider those for which the corressponding Riemann problem admits a selfsimilar solution. Some important examples of such problems are Shallow Water problems with irregular topography and two phase flows. The stability analysis of the considered scheme, in the homogeneous scalar case, leads to a new formulation which has a naturel extension to non homogeneous systems. Comparative numerical experiments for Shallow Water equations with sourec term, and a two phase problem (Ransom faucet) are presented to validate the scheme. Cet article concerne l'analyse et l'application, d'un schéma proposé récemment por une classe de systèmes non homogènes. Nous considérons ceux pour lesquels le problème de Riemann correpondant admet une solution autosimilaire. Deux exemples importants de tels problèmes sont l'écoulement d'eau peu profonde au-dessus d'un fond non plat et les problèmes diphasiques. l'analyse de stabilité du schéma, dans le cas scalaire homogène, amène à une nouvelle écriture qui a une extension naturelle pour le cas non homogène. Des expériences numériques comparatives pour des équations de saint-Venant avec topographie variable, et un problème diphasique (Robinet de Ransom) sont présentés pour évaluer l'efficacité du schéma.

scholarly journals Advances in the Stability of Halide Perovskite Nanocrystals

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3733 ◽  
Author(s):  
Maning Liu ◽  
Anastasia Matuhina ◽  
Haichang Zhang ◽  
Paola Vivo
Keyword(s):  
Special Focus ◽  
Next Generation ◽  
Facile Synthesis ◽  
Research Directions ◽  
Rapid Degradation ◽  
Perovskite Nanocrystals ◽  
Final Goal ◽  
Tunable Properties ◽  
Halide Perovskite ◽  
The Stability

Colloidal halide perovskite nanocrystals are promising candidates for next-generation optoelectronics because of their facile synthesis and their outstanding and size-tunable properties. However, these materials suffer from rapid degradation, similarly to their bulk perovskite counterparts. Here, we survey the most recent strategies to boost perovskite nanocrystals stability, with a special focus on the intrinsic chemical- and compositional-factors at synthetic and post-synthetic stage. Finally, we review the most promising approaches to address the environmental extrinsic stability of perovskite nanocrystals (PNCs). Our final goal is to outline the most promising research directions to enhance PNCs’ lifetime, bringing them a step closer to their commercialization.

scholarly journals Antioxidant activities of allspice extracts in rapeseed oil

2000 ◽  
Vol 18 (No. 2) ◽  
pp. 49-51 ◽  
Author(s):  
D.V. Nguyen ◽  
M. Takácsová ◽  
M.N. Dang ◽  
K. Kristiánová
Keyword(s):  
Rapeseed Oil ◽  
Antioxidant Activities ◽  
Ethanol Extract ◽  
Chloroform Extract ◽  
Antioxidant Effect ◽  
Hexane Extract ◽  
Antioxidant Effectiveness ◽  
The Stability ◽  
Benzene Extract

Spices are an important component of both commercial and homemade foods. Many spices have been shown to possess an antioxidant effect. In our study, we tested the activity of different allspice extracts (ethanol, chloroform, diethylether, benzene and hexane) on the stability of rapeseed oil. The order of antioxidant effectiveness was as follows: ethanol extract &gt; chloroform extract&gt; diethylether extract &gt; benzene extract &gt; hexane extract. The ethanol extract exhibited a remarkable antioxidant effect.

Factors affecting the stability and estimation of carotene in artificially dried grass and hays

1940 ◽  
Vol 30 (4) ◽  
pp. 622-638 ◽  
Author(s):  
S. K. Kon ◽  
S. Y. Thompson
Keyword(s):  
Chromatographic Analysis ◽  
Accurate Determination ◽  
Total Loss ◽  
Carotene Content ◽  
Factors Affecting ◽  
Ordinary Temperature ◽  
Initial Drop ◽  
The Difference ◽  
The Stability

1. The influence of storage in the light and in the dark at ordinary temperature and in a heated room at 70–80° F. on the carotene content of finely ground artificially dried grass stored in paper sacks and jute sacks was studied. There was an initial drop in carotene content from 61·1 to 46·5 mg./100 g., i.e. 23·9%, in the first month, and a total loss of 31·4% during 6 months' storage (August to February). No difference could be detected either between treatments or types of containers.2. There was a marked loss of carotene during 13 months' storage of baled artificially dried grass and of hays, amounting to 30–40% of the original value.3. Two methods of estimating carotene were compared. The method of Ferguson & Bishop (1936) gave higher results than the method of Peterson, Hughes & Freéman (1937). The difference is probably due to incomplete extraction in the latter method.4. Chromatographic analyses of “carotene” fractions from the above grasses showed the presence of coloured impurities amounting to 20·5–33·8% of the total recovered pigments.5. As these impurities are biologically inactive, chromatographic analysis or the use of special solvents are probably necessary for the accurate determination of carotene in forage.

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