Trithioarsenites [(RS)3As], dithioarsonites [R-As(SR′)2] and thioarsinites [R2As-SR′]: Preparations, chemical, biochemical and biological properties

2021 ◽  
pp. 1-26
Author(s):  
Panayiotis V. Ioannou
Keyword(s):  
Chemical Properties ◽  
Biological Properties ◽  
Alkyl Halides ◽  
Metal Carbonyls ◽  
Electron Pairs ◽  
Antiparasitic Activity ◽  
Agricultural Applications ◽  
Patent Literature ◽  
Points Of View ◽  
Acyl Derivatives

Contrary to P(V) compounds, As(V) compounds can very easily reduced by thiols to As(III) thiolates that are deemed to play a central role in the metabolism of arsenic and therefore a review on the preparation and properties of the title thiolates can be of interest. The preparation of trithioarsenites, dithioarsonites and thioarsinites involves reactions of a thiol with a proper As(V) or As(III) precursor via 4-centered transition states or a thiolate by SN2 mechanisms. Convenient precursors are the solids As2O3, arsonic and arsinic acids, although for the latter two acids the separation of the product from the co-produced disulfides can be problematic. Only a few crystal structures have been reported and involve only trithioarsenites. From their chemical properties, the hydrolyses, transthiolations and air oxidations are of particular interest from mechanistic and biochemical/biological points of view. Their nucleophilicity towards alkyl halides and acyl derivatives revealed unexpected behavior. Although these molecules have many free electron pairs only three reports were found pertaining to their reaction with metal cations (Hg2+) and metal carbonyls; the mercuric complexes being not characterized. Only a few studies appeared for the action of the title compounds towards enzymes, while the patent literature revealed that they have bactericidal, fungicidal and insecticidal activities for agricultural applications, some have antiparasitic activity on animals and a few are carcinostatic.

PLGA+HA/βTCP scaffold incorporating simvastatin: a promising biomaterial for bone tissue engineering

2020 ◽  
Author(s):  
Mariane Beatriz Sordi ◽  
Ariadne Cristiane Cabral da Cruz ◽  
Águedo Aragones ◽  
Mabel Mariela Rodríguez Cordeiro ◽  
Ricardo de Souza Magini
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Thermal Analyses ◽  
Chemical Properties ◽  
Biological Properties ◽  
Scanning Calorimetry ◽  
Evaporation Technique ◽  
Porosity Analysis ◽  
Biphasic Ceramic

The aim of this study was to synthesize, characterize, and evaluate degradation and biocompatibility of poly(lactic-co-glycolic acid) + hydroxyapatite / β-tricalcium phosphate (PLGA+HA/βTCP) scaffolds incorporating simvastatin (SIM) to verify if this biomaterial might be promising for bone tissue engineering. Samples were obtained by the solvent evaporation technique. Biphasic ceramic particles (70% HA, 30% βTCP) were added to PLGA in a ratio of 1:1. Samples with SIM received 1% (m:m) of this medication. Scaffolds were synthesized in a cylindric-shape and sterilized by ethylene oxide. For degradation analysis, samples were immersed in PBS at 37 °C under constant stirring for 7, 14, 21, and 28 days. Non-degraded samples were taken as reference. Mass variation, scanning electron microscopy, porosity analysis, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetry were performed to evaluate physico-chemical properties. Wettability and cytotoxicity tests were conducted to evaluate the biocompatibility. Microscopic images revealed the presence of macro, meso, and micropores in the polymer structure with HA/βTCP particles homogeneously dispersed. Chemical and thermal analyses presented very similar results for both PLGA+HA/βTCP and PLGA+HA/βTCP+SIM. The incorporation of simvastatin improved the hydrophilicity of scaffolds. Additionally, PLGA+HA/βTCP and PLGA+HA/βTCP+SIM scaffolds were biocompatible for osteoblasts and mesenchymal stem cells. In summary, PLGA+HA/βTCP scaffolds incorporating simvastatin presented adequate structural, chemical, thermal, and biological properties for bone tissue engineering.

Chitosan-Nanocellulose Composites for Regenerative Medicine Applications

2020 ◽  
Vol 27 (28) ◽  
pp. 4584-4592 ◽  
Author(s):  
Avik Khan ◽  
Baobin Wang ◽  
Yonghao Ni
Keyword(s):  
Regenerative Medicine ◽  
Preparation Method ◽  
Chemical Properties ◽  
Biological Properties ◽  
Next Generation ◽  
Structure Property ◽  
Physico Chemical ◽  
Structure Property Relationship ◽  
Attractive Candidate ◽  
Fundamental Understanding

Regenerative medicine represents an emerging multidisciplinary field that brings together engineering methods and complexity of life sciences into a unified fundamental understanding of structure-property relationship in micro/nano environment to develop the next generation of scaffolds and hydrogels to restore or improve tissue functions. Chitosan has several unique physico-chemical properties that make it a highly desirable polysaccharide for various applications such as, biomedical, food, nutraceutical, agriculture, packaging, coating, etc. However, the utilization of chitosan in regenerative medicine is often limited due to its inadequate mechanical, barrier and thermal properties. Cellulosic nanomaterials (CNs), owing to their exceptional mechanical strength, ease of chemical modification, biocompatibility and favorable interaction with chitosan, represent an attractive candidate for the fabrication of chitosan/ CNs scaffolds and hydrogels. The unique mechanical and biological properties of the chitosan/CNs bio-nanocomposite make them a material of choice for the development of next generation bio-scaffolds and hydrogels for regenerative medicine applications. In this review, we have summarized the preparation method, mechanical properties, morphology, cytotoxicity/ biocompatibility of chitosan/CNs nanocomposites for regenerative medicine applications, which comprises tissue engineering and wound dressing applications.

scholarly journals Effect of Crosslinking Type on the Physical-Chemical Properties and Biocompatibility of Chitosan-Based Electrospun Membranes

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 831
Author(s):  
Andrea Dodero ◽  
Sonia Scarfi ◽  
Serena Mirata ◽  
Alina Sionkowska ◽  
Silvia Vicini ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Biological Properties ◽  
Diglycidyl Ether ◽  
Chemical Crosslinking ◽  
Electrospinning Technique ◽  
Vapour Permeability ◽  
Phosphate Ions ◽  
Physically Crosslinked ◽  
Mechanical Performances ◽  
Average Size

Chitosan nanofibrous membranes are prepared via an electrospinning technique and explored as potential wound healing patches. In particular, the effect of a physical or chemical crosslinking treatment on the mat morphological, mechanical, water-related, and biological properties is deeply evaluated. The use of phosphate ions (i.e., physical crosslinking) allows us to obtain smooth and highly homogenous nanofibers with an average size of 190 nm, whereas the use of ethylene glycol diglycidyl ether (i.e., chemical crosslinking) leads to rougher, partially coalesced, and bigger nanofibers with an average dimension of 270 nm. Additionally, the physically crosslinked mats show enhanced mechanical performances, as well as greater water vapour permeability and hydrophilicity, with respect to the chemically crosslinked ones. Above all, cell adhesion and cytotoxicity experiments demonstrate that the use of phosphate ions as crosslinkers significantly improves the capability of chitosan mats to promote cell viability owing to their higher biocompatibility. Moreover, tuneable drug delivery properties are achieved for the physically crosslinked mats by a simple post-processing impregnation methodology, thereby indicating the possibility to enrich the prepared membranes with unique features. The results prove that the proposed approach may lead to the preparation of cheap, biocompatible, and efficient chitosan-based nanofibers for biomedical and pharmaceutical applications.

Geotechnical Applications of Sewage Sludge Stabilized with Biomass Ash and its Effect on Soil Nutriential Properties: A Critical Review

2021 ◽  
Vol 9 (VI) ◽  
pp. 1046-1051
Author(s):  
Ishowriya Yumnam
Keyword(s):  
Sewage Sludge ◽  
Positive Impact ◽  
Chemical Properties ◽  
Past Research ◽  
Biological Properties ◽  
Engineering Properties ◽  
Biomass Ash ◽  
The Past ◽  
Waste Sewage Sludge ◽  
Properties Of Soil

In this review article the usage of waste sewage sludge and the biomass ash for improving the engineering and non-engineering properties’ of both concrete and soil are discussed in detail. Numerous past research works were studied in detail so as to predict the behavior of biomass ash and waste sewage sludge when used for the stabilization process of soil and concrete. Past studies related to the usage of stabilized sewage sludge and biomass ash were studied in a detailed manner and depending upon the past studies several conclusions has been drawn which are discussed further. Several studies related to the usage of the waste sewage sludge for improving soil physical, chemical and biological properties showed that the usage of waste sewage sludge improve the physical properties, chemical properties, macro-nutriential properties and micro-nutriential properties up to a great extent. Depending upon the results of the past studies it can be concluded that the usage of sewage sludge has positive impact over all the properties of soil and this waste should be utilized in improving the properties of soil rather than dumping. Numerous studies related to the usage of the biomass ash showed that biomass ash has positive impact over both soil as well as concrete. Studies related to the usage of the biomass ash in soil showed that there was a positive response of the stabilized soil after its stabilization with the biomass ash. Studies related to the usage of the biomass ash in concrete showed that the biomass ash can be used up to 10 percent replacement of the ordinary Portland cement so as to attain maximum strength results from it.

scholarly journals CHEMISTRY AND SYNTHESIS OF SOME DIHYDRO-2H-l,4-BENZOTHIAZINE DERIVATIVES

1966 ◽  
Vol 44 (11) ◽  
pp. 1247-1258 ◽  
Author(s):  
Raj Nandan Prasad ◽  
Karin Tietje
Keyword(s):  
Alkyl Halides ◽  
Reduction Product ◽  
Alkyl Derivatives ◽  
Reaction Proceeds ◽  
Thiazine Ring ◽  
Derivatives Of ◽  
Compound Xviii ◽  
Acyl Derivatives

The formation of 3-oxo-3,4-dihydro-2H-1,4-benzothiazine (IIIa) by cyclization of alkyl 2-haloacetamidophenyl sulfides (I) was investigated; it is proposed that the reaction proceeds via a six-membered sulfonium halide. The preparation of 4-alkyl derivatives of IIIa and of 4-alkyl and 4-acyl derivatives of its reduction product 3,4-dihydro-2H-1,4-benzothiazine (Va) is described. Acylation of Va was shown to proceed without opening of the thiazine ring. Preparation of the O-benzoyl, N-benzoyl, and O,N-dibenzoyl derivatives of 2-(β-hydroxyethyl-mercapto)aniline (VIII) has permitted clarification of the confusion in the literature with respect to the derivatives of Va and VIII. Compound XVIII, the 1,1-dioxide of IIIa, undergoes C-alkylation at the 2-position when treated with alkyl halides, rather than O-alkylation as previously suggested.

scholarly journals The effect of various composts on vegetable green mass on two soil types

2017 ◽  
pp. 179-183
Author(s):  
Judit Szűcsné Szolomájer ◽  
Marianna Makádi ◽  
Ibolya Demeter ◽  
Attila Tomócsik ◽  
Tibor Aranyos ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Nutrient Content ◽  
Biological Properties ◽  
Matter Content ◽  
Soil Types ◽  
Test Plant ◽  
Positive Effects ◽  
Supply Capacity

Composting of sewage sludges makes easier the utilization of sewage sludge in the agriculture and the composts in good quality could increase the nutrient content of soil. Due to the composting process, the sewage sludge composts with high organic matter content can be utilized in the same way as other composts or farmyard manure.Composts produced in different ways have different effects on the physical, chemical and biological properties of different soils, although their positive effects have already proved in the literature. In our study the effects of composts from different composting processes were investigated in soil-plant systems. The different physical and chemical properties of the two examined soil types (arenosol and chernozem)strongly influenced the nutrient supply capacity of composts which could be characterized by the growth of ray-grass as a test plant in the pot experiment. In this work we examined the effects of three different composts on the green weight of plants on the fourth and eighth weeks after the treatment and sowing.

scholarly journals Effect of exposure of African catfish (Clarias batrachus) to magnetic field on water properties and egg hatching

2018 ◽  
Vol 2 ◽  
pp. 54-59
Author(s):  
Sadam Mohamad Hassan ◽  
Ridzwan A. Rahman ◽  
Rezuan H. Kamaruddin ◽  
Najilaa S. Madlul
Keyword(s):  
Magnetic Field ◽  
Clarias Gariepinus ◽  
Chemical Properties ◽  
Biological Properties ◽  
Specific Conductance ◽  
African Catfish ◽  
Field Exposure ◽  
Egg Hatching ◽  
Magnetic Devices ◽  
Water Properties

Magnetic water is produced when water is passed through a magnetic field with the purpose of modifying its structure. The changes in physical and chemical properties of magnetised water affect the biological properties of the organisms. The magnetic field can affect the growth of fish from the embryo to the adult stage. The present study evaluates the effects of magnetic field exposure on water properties and hatchability of the eggs of African catfish (Clarias gariepinus). Water was passed through magnetic devices of different intensities; namely: 0.10, 0.15 and 0.20 Tesla. The dissolved oxygen (mgL-1) and pH levels were found to significantly (P ≤ 0.05) increase from 5.92 mgL-1 to 6.33 mgL-1, and from 8.03 to 8.19, respectively. Ammonium (NH4-N mgL-1) level declined significantly (P ≤ 0.05) (0.20 mgL-1 to 0.16 mgL-1). Salinity (ppt), conductivity (uscm-1), specific conductance (uscm-1) and total dissolved solids (mgL-1) also decreased after magnetization. Significant increase in the rate of hatching was attained in water exposed to a magnetic field of 0.10, 0.15 and 0.20 T. The study demonstrated the benefits of using magnetic devices that are simple, practical and cost-effective.

scholarly journals PASSAGE OF WHEAT FIRE IMPACT ON SOIL PROPERTIES AND ENVIRONMENT IN KURDISTAN REGION

2021 ◽  
Vol 52 (2) ◽  
pp. 461-470
Author(s):  
Tariq & et al.
Keyword(s):  
Soil Properties ◽  
Ph Value ◽  
Fire Severity ◽  
Chemical Properties ◽  
Field Capacity ◽  
Infiltration Rate ◽  
Germination Percentage ◽  
Biological Properties ◽  
Surface Burn ◽  
Effect Of Surface

The study was conducted to examine the effect of surface burn severity (Moderate, Severe and Unburned) of wheat straw on soil properties. The results showed statistical differences in some soil physical, chemical and biological properties. Bulk density and field capacity increased statistically by the severity of fire; however, porosity and infiltration rate were statistically lower in sever burned plot when compared to unburned plot. The chemical properties, soil organic matter (SOM), P, Ca, S, Cl, K, Mo, Fe and As were not affected by the fire. The pH value was increased slightly by increasing the fire severity, while, EC was decreased when compared with the unburned plot. It was found a statistical reduction in the number of bacterial and fungal cells per gram soil in the burned plots. A moderate and severe fire reduced seed germination percentage significantly. This finding suggests that fire severity may destruct the biological, physical and some of the chemical properties of the soil, and this may impact negatively on plant growth in the next growing season.

scholarly journals Structure Determination of C23H19N4OBr from Synchrotron Data

2014 ◽  
Vol 70 (a1) ◽  
pp. C141-C141
Author(s):  
Ozen Ozgen ◽  
Engin Kendi ◽  
Semra Koyunoglu ◽  
Akgul Yesilada ◽  
Hwo-Shuenn Sheu
Keyword(s):  
Powder Diffraction ◽  
Structural Information ◽  
Chemical Properties ◽  
Biological Properties ◽  
Cell Parameters ◽  
Fundamental Understanding ◽  
Physical And Chemical ◽  
Radiation Research ◽  
And Chemical Properties

A significant part of medicine is based on the discovery and development of drugs. It is very important to know the crystal structure of pharmaceutical compounds for fundamental understanding of structure, physical and chemical properties. Many of these materials are available only as powders. So any structural information must be obtained from powder diffraction. I am going to present following the stages while solving the structure of C23H19N4OBr, 2-[3-phenyl-4(m-bromophenyl)-2-pyrazolin-1-yl]-3-methyl-4(3H)-quinazolinone, from 2-pyrazolines derivatives. The compounds are known to display various biological properties such as fungicidal insecticidal, anti bacterial, anti viral activities, pharmacological properties such as antiinflammatory agents and have industral properties(1). The powder diffraction data was collected with Debye Scherrer camera at the BL01C2 beamline at room temperature in National Synchrotron Radiation Research Center(NSRRC), Taiwan. X-ray of wavelength was 1.0333Å. This compound crystallizes in orthorhombic system space group P bca, Z=8, unit cell parameters of a=25.83(1)Å, b=15.55(5)Å, c=10.63(3)Å, and V=4266.0(10)Å3. Reliability factors were reached Rwp=0.075, Rp=0.053, RB=0.086 ve S=1.31 after Rietveld refinement.

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