scholarly journals Researches Concerning Chemical Modifications of Hair Keratin

2019 ◽  
Vol 70 (6) ◽  
pp. 2091-2095
Author(s):  
Vasile Ciprian Macarel ◽  
Cezar Doru Radu ◽  
Liliana Verestiuc ◽  
Florina Daniela Ivan ◽  
Eugen Ulea ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Electrostatic Interactions ◽  
Control Sample ◽  
Cellulose Film ◽  
Chemical Modifications ◽  
Alcoholic Medium ◽  
Swelling Degree ◽  
Hair Keratin ◽  
Morphological Organization

The work presents chemical procedures used to obtain a film or a hydrogel after hydrolyze treatment of hair at the temperature of 150oC and the pressure of 4.9 atm. In order to obtain the hydrogel, this treatment is followed by a stage of oxidation with hydrogen peroxide, and a stage of reduction with Na2S2O4 or, in another variant, a stage of oxidation with hydrogen peroxide and a treatment with NaOH in alcoholic medium, to form natrium cationic groups. The protein chains with sulphonic groups and natrium cations determine opposite electrostatic interactions, with the formation of a polymer loop that incorporate water. The evaluation of formed hydrogel was carried out by determining the swelling degree. We have used optical and SEM photomicrographs to determine morphological organization, and EDAX micropictures for chemical modifications. A cellulose film realized by growing Gluconoacetobacter xylinus bacteria was used as control sample.

scholarly journals Effectiveness of Chemical and Thermal Treatments on Control Rhizopus Stolonifer Fruit Infection Comparing Tomato Cultivars with Different Sensitivities to Cracking

2019 ◽  
Vol 16 (15) ◽  
pp. 2754 ◽  
Author(s):  
Alfaro-Sifuentes ◽  
Juan ◽  
Meca ◽  
Elorrieta ◽  
Valenzuela
Keyword(s):  
Hydrogen Peroxide ◽  
Tomato Fruit ◽  
Control Sample ◽  
Hot Water ◽  
Economic Losses ◽  
Rhizopus Stolonifer ◽  
Tomato Fruits ◽  
Horticultural Crops ◽  
Tomato Yield ◽  
Fruit Cracking

Tomatoes are among the most important horticultural crops; however, it is estimated that 30% of tomato yield is lost due to postharvest rot due to Rhizopus stolonifer, a fungus which requires lesions to initiate the infectious process. Tomato fruit cracking is a physiopathy which causes significant economic losses, since cracking is the door used by the fungus. In this experiment, 14 cultivars of tomato of different types were used. Fruit sampling was carried out in the middle of the crop cycle, coinciding with the peak of yield; then, the fruits were divided into two groups: one group was inoculated with Rhizopus in order to assess the effectiveness of washing, whilst the other was treated with sterile water. The fruits of each group were divided into lots to be treated with six washing treatments: dipping in hot water at 20, 40 and 60 °C for 20 s; the fruits were then sprayed with the following solutions: 0.6% of Hydrogen Peroxide 23% + Peracetic acid 15%; commercial bleach at 0.5% and 2% of Hydrogen Peroxide 50%. The control sample was not washed. The results show that there was an influence of cultivar on fruit cracking, which was strongly related with Rhizopus infection. Three cultivars were not susceptible to cracking, and therefore, were not sensitive to Rhizopus infection. The effectiveness of different washing treatments of tomato fruits depends on several factors; nonetheless, hot water treatment has been shown to be more effective than the use of chemical products such as commercial bleach or hydrogen peroxide. Another factor, the susceptibility of cultivars to cracking, determines the effectiveness of the washing treatment. The results provide an important basis for making decisions about the washing management of tomato fruits in packaging houses.

scholarly journals Decomposition of Glucose-Sensitive Layer-by-Layer Films Using Hemin, DNA, and Glucose Oxidase

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 319 ◽  
Author(s):  
Kentaro Yoshida ◽  
Yu Kashimura ◽  
Toshio Kamijo ◽  
Tetsuya Ono ◽  
Takenori Dairaku ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Dna Cleavage ◽  
Electrostatic Interactions ◽  
Glucose Solution ◽  
Layer By Layer ◽  
Sensitive Layer ◽  
Physiological Conditions ◽  
Lbl Films ◽  
Low Glucose

Glucose-sensitive films were prepared through the layer-by-layer (LbL) deposition of hemin-modified poly(ethyleneimine) (H-PEI) solution and DNA solution (containing glucose oxidase (GOx)). H-PEI/DNA + GOx multilayer films were constructed using electrostatic interactions. The (H-PEI/DNA + GOx)5 film was then partially decomposed by hydrogen peroxide (H2O2). The mechanism for the decomposition of the LbL film was considered to involve more reactive oxygen species (ROS) that were formed by the reaction of hemin and H2O2, which then caused nonspecific DNA cleavage. In addition, GOx present in the LbL films reacts with glucose to generate hydrogen peroxide. Therefore, decomposition of the (H-PEI/DNA + GOx)5 film was observed when the thin film was immersed in a glucose solution. (H-PEI/DNA + GOx)5 films exposed to a glucose solution for periods of 24, 48 72, and 96 h indicated that the decomposition of the film increased with the time to 9.97%, 16.3%, 23.1%, and 30.5%, respectively. The rate of LbL film decomposition increased with the glucose concentration. At pH and ionic strengths close to physiological conditions, it was possible to slowly decompose the LbL film at low glucose concentrations of 1–10 mM.

EFFECT OF COLLAGEN ON THE MORPHOLOGY AND STRUCTURE OF CALCIUM PHOSPHATE NANOPARTICLES

2014 ◽  
Vol 26 (05) ◽  
pp. 1450061
Author(s):  
Hoda Salemi ◽  
Aliasghar Behnamghader ◽  
Mohamadreza Baghaban Eslaminejad ◽  
Mohammad Ataei
Keyword(s):  
Calcium Phosphate ◽  
Electrostatic Interactions ◽  
Type I Collagen ◽  
Bone Matrix ◽  
Control Sample ◽  
Molar Ratio ◽  
Type I ◽  
Sem Images ◽  
Collagen Concentration ◽  
Calcium Phosphate Nanoparticles

Collagen and noncollagenous proteins have an important role in the formation of mineral constituent of bone matrix. In this research, the morphology and phase characteristics of calcium phosphate nanoparticles in presence of collagen were investigated. The synthesis reaction was initiated by mixing H 3 PO 4 as phosphorous source and CaCl 2 as calcium source and type I collagen. Collagen concentration in suspension and Ca to P ratio was 1% and 1.67, respectively. The samples (with collagen and without collagen), were heat treated at 600°C and characterized by X-Ray diffraction (XRD), Fourier transformation infrared (FTIR) and scanning electron microscopy (SEM). More smaller and flake-like shape particles were observed in the SEM images of sample synthesized in the presence of collagen compared to the control sample which was constituted of larger granular particles. The XRD results revealed that the synthesized mineral powders with collagen were composed of hydroxyapatite and octacalcium phosphate. P – O and OH characteristic peaks were identified in FTIR spectra. In hybrid sample, the shift of amides band, revealed the electrostatic interactions between calcium phosphate ions and carboxyl or amino groups of collagen fibrils. The Ca to P molar ratio for sample with collagen was 1.9. It was found that the sample synthesized in the presence of collagen has a similar microstructure to natural bone.

Study of natural adsorbent chitosan and derivatives for the removal of caffeine from water

2012 ◽  
Vol 47 (1) ◽  
pp. 80-90 ◽  
Author(s):  
Serena Sanford ◽  
Kripa S. Singh ◽  
Sahil Chaini ◽  
Gaetan LeClair
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Mesoporous Materials ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Chemical Modifications ◽  
High Affinity ◽  
Natural Adsorbent ◽  
Batch Tests

The adsorption of caffeine was evaluated using natural adsorbent chitosan and three derivates of the material. Raw, H2O2 pre-treated, and a chemically altered chitosan were compared to activated carbon. Activated carbon was found to have a high affinity for caffeine (98% removal) while raw chitosan performed poorly with an average adsorption of 15.9%. Batch tests in acidic and basic conditions as well as increasing dosage did not have an effect on the performance. Chemical modifications to chitosan included calcinated mesoporous materials and non-calcinated materials, both of which increased chitosan adsorption of caffeine to 29 and 40%, respectively. Hydrogen peroxide pre-treated chitosan performed best of chitosan-based adsorbents, and reached a 46% removal of caffeine in batch adsorption tests. The majority of the adsorbents had low correlation to the Langmuir, Freundlich, and Redlich–Peterson isotherm models. However, data were sufficient to compare adsorption capacity for caffeine among activated carbon, chitosan, and chitosan derivatives.

scholarly journals A Novel Nanocomposite of Activated Serpentine Mineral Decorated with Magnetic Nanoparticles for Rapid and Effective Adsorption of Hazardous Cationic Dyes: Kinetics and Equilibrium Studies

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 684 ◽  
Author(s):  
Moaaz K. Seliem ◽  
Mariusz Barczak ◽  
Ioannis Anastopoulos ◽  
Dimitrios A. Giannakoudakis
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Environmental Remediation ◽  
Electrostatic Interactions ◽  
Active Sites ◽  
Eastern Desert ◽  
Cationic Dyes ◽  
Significant Deterioration ◽  
Equilibrium Studies ◽  
The Difference

A widely distributed mineral, serpentine, obtained from Wadi Ghadir (Eastern Desert in Egypt) was studied as a potential naturally and abundantly available source for the synthesis of an efficient adsorbent for aquatic remediation applications. A novel nanocomposite was synthesized after the exfoliation of the layered structure of serpentine by hydrogen peroxide treatment (serpentine (SP)), followed by decoration with magnetic Fe3O4 nanoparticles (MNP). The goal behind the utilization of the latter phase was to increase the environmental remediation capability and to incorporate magnetic properties at the final adsorbent, toward a better separation after the use. The fabricated composite (MNP/SP) was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The composite’s potential adsorption application toward the removal of two cationic dyes, methylene blue (MB) and malachite green (MG), was investigated. The observed adsorption kinetics was fast, and the highest uptake was observed at pH = 8, with the capacities to reach 162 and 176 mg g−1 for MB and MG, respectively, values significantly higher than various other materials tested against these two cationic dyes. Compared to hydrogen peroxide-treated serpentine, the removal efficiency of the composite was higher by 157 and 127% for MB and MG, respectively. The MB and MG were adsorbed because of the favorable electrostatic interactions between MNP/SP active sites and the cationic dyes. The close value capacities suggest that the difference in chemistry of the two dyes does not affect the interactions, with the later occurring via the dyes’ amine functionalities. With increasing ionic strength, the adsorption of the studied basic dyes was slightly decreased, suggesting only partial antagonistic ion effect. The sorbent can be easily regenerated and reused without significant deterioration of its adsorption efficiency, which makes MNP/SP a promising adsorbent for the removal of hazardous pollutants from aquatic environments.

Decomposition of Glucose-Sensitive Layer-by-Layer Films Using Hemin, DNA, and Glucose Oxidase

2019 ◽  
Author(s):  
Kentaro Yoshida ◽  
Yu Kashimura ◽  
Toshio Kamijo ◽  
Tetsuya Ono ◽  
Takenori Dairaku ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Glucose Concentration ◽  
Dna Cleavage ◽  
Electrostatic Interactions ◽  
Glucose Solution ◽  
Layer By Layer ◽  
Sensitive Layer ◽  
Physiological Conditions ◽  
Lbl Films

Glucose-sensitive films were prepared by the layer-by-layer (LbL) deposition of poly(ethyleneimine) (H-PEI) solution and DNA solution (containing glucose oxidase (GOx)). H-PEI/DNA+GOx multilayer films were constructed using electrostatic interactions. The (H-PEI/DNA+GOx)5 film was then partially decomposed by hydrogen peroxide (H2O2). The mechanism for the decomposition of the LbL film was considered to involve a more reactive oxygen species (ROS) that was formed by the reaction of hemin and H2O2, which then caused nonspecific DNA cleavage. GOx present in the LbL films reacts with glucose to generate hydrogen peroxide. Therefore, decomposition of the H-PEI/DNA+GOx)5 film was observed when the thin film was immersed in a glucose solution. A (H-PEI/DNA+GOx)5 film exposed to a glucose solution for periods of 24, 48 72, and 96 h indicated decomposition of the film increased with the time. The rate of LbL film decomposition increased with the glucose concentration. At pH and ionic strength close to physiological conditions, it was possible to slowly decompose the LbL film at a sub-millimolar glucose concentration.

scholarly journals Investigating the possibility of using recycled magazine paper in the production of newsprint with the aim of proper management of paper waste

2021 ◽  
Author(s):  
Seyedeh Fateme Shahcheragh
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
High Resistance ◽  
Control Sample ◽  
High Volume ◽  
Environmental Concerns ◽  
Recycled Paper ◽  
Flotation Method ◽  
Broadleaf Species

Abstract In recent yr. due to reduced ligneous resources, increased demand for paper products, increased environmental concerns that are made from virgin papers production, and high volume of waste papers, the need for recycling of papers is felt more than ever. One of the important steps in the process of recycling paper is the deinking of waste papers. The purpose of this study is the deinking of the old magazine papers in order to produce newsprint. In the review, old magazine papers were deinked by Flotation method using: Sodium hydroxide (1%), Sodium silicate (2%), Hydrogen peroxide (1%), and DTPA (1%). Then they were bleached with an amount of Hydrogen peroxide (1/5%). 60 grams of paper was made under standard conditions for testing. Then the brightness of handmade papers was measured in three replicates. The result showed that the brightness of non-deinked papers was about 40%, after deinking it was about 50%, and after bleaching it was increased to about 60%. Results indicate that the use of Hydrogen peroxide and its derivatives in bleaching of waste papers are resulted in increasing brightness in several percent. By combining pulp prepared from recycled magazine paper with CMP pulp prepared from a broadleaf species, the results showed that the addition of deinked OMG significantly reduced the brightness of the control sample. Also, adding deinked magazine paper in any proportion to the mixture of imported CMP pulp and long fiber pulp (by increasing the opacity) improves the quality of the printed paper obtained. This recycled paper can be used in production papers that are used temporary and do not need high resistance (such as newsprints).

scholarly journals THE TREATMENT OF THE I-II SТAGES PRESSURE ULCERS WITH MACERATION, LOCAL EXEMATISATION AND DESQUAMATION OF THE EPIDERMIS: SOME SPECIFICS OF MANUFACTURING AND USE, ANALYSIS OF CLINICAL CASES

2020 ◽  
Vol 1 (39) ◽  
Author(s):  
A. R. Vergun ◽  
M. B. Kalytovska ◽  
A. V. Yutanova ◽  
V. V. Kulchytskyi ◽  
O. M. Vergun ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Pressure Ulcers ◽  
Control Sample ◽  
Main Group ◽  
The Body ◽  
Stage I ◽  
Control Group ◽  
Complex Treatment ◽  
Prepared Powder ◽  
Antiseptic Treatment

It is known that the main causes of decubital ulcers (bedsores) are ischemia and neurotrophic soft tissue pathology caused by chronic local compression, nutritional disorders, urinary and fecal incontinence, metabolic disorders. Significant risk factors are the presence of diabetes mellitus, a condition after suffering a cerebral circulation disorder, and other neurological pathology, in patients with insufficient or inadequate care. In addition to decompression of problem areas, periodic changes in the spatial position of the body in combination with antiseptic treatment in complex therapy should take into account the nutritional state, circulation, microcirculation and oxygenation in tissues, skin moisture (excessive humidity increases the risk), neurodegeneration, the stage of process, local diaper rash and maceration. The aim of the work. To optimize and improve the results of treatment of stage I-II bedsores with diaper rash, maceration, exematisation and epidermis desquamation by local therapy using clinoptilolite-based powders and to substantiate the prospects of using this method in clinical practice. The main study group over 3-year period consisted of the results of complex treatment of 28 patients, age 72-87 years: 17 women and 11 men with I-II stages of bedsores with diaper rash, maceration, local exematisation and desquamation of the epidermis and formation of superficial ulcer. The control sample consisted of the results of the treatment of 32 patients with decubital ulcers I and II stages, who were treated inpatient in the palliative care departament of the municipal non-profit enterprise "4th City Clinical Hospital" in Lviv with the use of antiseptic remediation, use of streptocid and metronidazole containing powder according to generally accepted recommendations, clinical strategies, and local protocols.Patients in the main group performed sequential repair of the wound surface with a 3% solution of hydrogen peroxide, 20% chlorhexidine bigluconate solution and sprinkling extratemporally prepared powder containing fucorcin (17 patients) or brilliant green (11 other observations). Patients in the control group were sequentially sanitized with a 3% solution of hydrogen peroxide, 1% polyvidone iodine solution, and an extratemporally prepared powder, which, in addition to the adsorbent, contained powdered white streptocide and powdery metronidasole. During daily dressings repeated repairs were carried out – washing with antiseptics of maceration sites, drying with sterile gauze wipes and filling with powder. Patients with type II diabetes have insulin resistance and deviations from laboratory parameters. The criterion for the effectiveness of care and treatment was to reduce exudation with marginal epithelialization, and (or) crust formation. In the patients of the main group, the rate of healing of wounds and macerated areas was 4.8±0.12%, in the control group – 3.2±0.25% (χ2=28.62, p<0,01). In patients of the main group with cytological examination on 3, 5 and 12 days after the initial debridement in the smears of maceration areas consistently decreased the leukocytes, appeared macrophages and fibroblasts. In the control group at 5 days after primary debridement, segmental leukocytes were prevailed, cytological signs of regeneration were less pronounced (degree of exposure, χ2=31.12, significance level, p<0.01). On day 15, we observed the correction of sites of bedsores I and II stages with maceration and local epidermis desquamation in all patients of the main group and 60.71% of the of the control group. It is stated that clinoptilolite actively adsorbs of the wound secretions and bacterial toxins from the maceration surface and superficial I and II stages decubital ulcers, releases into the wound pre-adsorbed antiseptics, which are part of the proposed powders and have a pronounced antibacterial development, when is optimal for reparative processes and the healing environment that promotes healing of the superfitial pressure ulcers.Key words: pressure ulcers, stage I-II bedsores, diaper rash with maceration sites, exematisation and desquamation, clinoptilolite-containing powder, complex treatment

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