Subjects -> CHEMISTRY (Total: 1001 journals)
    - ANALYTICAL CHEMISTRY (59 journals)
    - CHEMISTRY (726 journals)
    - CRYSTALLOGRAPHY (23 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (45 journals)
    - ORGANIC CHEMISTRY (49 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (726 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
Accounts of Materials Research     Hybrid Journal  
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 36)
ACS Applied Polymer Materials     Hybrid Journal   (Followers: 15)
ACS Catalysis     Hybrid Journal   (Followers: 78)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 25)
ACS Combinatorial Science     Hybrid Journal   (Followers: 25)
ACS Macro Letters     Hybrid Journal   (Followers: 34)
ACS Materials Letters     Open Access   (Followers: 4)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 49)
ACS Nano     Hybrid Journal   (Followers: 452)
ACS Photonics     Hybrid Journal   (Followers: 19)
ACS Symposium Series     Full-text available via subscription   (Followers: 3)
ACS Synthetic Biology     Hybrid Journal   (Followers: 40)
Acta Chemica Iasi     Open Access   (Followers: 8)
Acta Chemica Malaysia     Open Access  
Acta Chimica Slovaca     Open Access   (Followers: 4)
Acta Chimica Slovenica     Open Access   (Followers: 2)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access   (Followers: 1)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 10)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 9)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 10)
Adsorption Science & Technology     Open Access   (Followers: 9)
Advanced Electronic Materials     Hybrid Journal   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 81)
Advanced Journal of Chemistry, Section A     Open Access   (Followers: 15)
Advanced Journal of Chemistry, Section B     Open Access   (Followers: 14)
Advanced Science Focus     Free   (Followers: 7)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 5)
Advanced Therapeutics     Hybrid Journal   (Followers: 1)
Advances in Chemical Engineering and Science     Open Access   (Followers: 108)
Advances in Chemical Science     Open Access   (Followers: 50)
Advances in Chemistry     Open Access   (Followers: 39)
Advances in Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 21)
Advances in Drug Research     Full-text available via subscription   (Followers: 27)
Advances in Environmental Chemistry     Open Access   (Followers: 11)
Advances in Enzyme Research     Open Access   (Followers: 13)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 20)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 35)
Advances in Nanoparticles     Open Access   (Followers: 20)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 20)
Advances in Polymer Science     Hybrid Journal   (Followers: 54)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 22)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 7)
Advances in Science and Technology     Full-text available via subscription   (Followers: 17)
Aerosol Science and Engineering     Hybrid Journal  
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 6)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Aggregate     Open Access   (Followers: 3)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 3)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 5)
Alchemy : Jurnal Penelitian Kimia     Open Access   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 71)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 24)
American Journal of Chemistry     Open Access   (Followers: 41)
American Journal of Plant Physiology     Open Access   (Followers: 13)
Analyst     Full-text available via subscription   (Followers: 40)
Analytical Science Advances     Open Access   (Followers: 2)
Angewandte Chemie     Hybrid Journal   (Followers: 238)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 354)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 8)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 4)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 6)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 13)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 16)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 12)
Applied Spectroscopy     Full-text available via subscription   (Followers: 27)
Applied Surface Science     Hybrid Journal   (Followers: 33)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Applied Chemistry Research     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemical Sciences     Open Access   (Followers: 1)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access   (Followers: 2)
Asian Journal of Physical and Chemical Sciences     Open Access   (Followers: 3)
Atomization and Sprays     Full-text available via subscription   (Followers: 8)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 7)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 485)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 3)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 4)
Biomacromolecules     Hybrid Journal   (Followers: 27)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 11)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 4)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 217)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 88)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 4)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 26)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 5)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 13)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Polymer Technologies and Applications     Open Access   (Followers: 3)
Carbohydrate Polymers     Hybrid Journal   (Followers: 13)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 76)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 13)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 4)
Catalysts     Open Access   (Followers: 14)
Cell Reports Physical Science     Open Access  
Cellulose     Hybrid Journal   (Followers: 17)
Cereal Chemistry     Full-text available via subscription   (Followers: 6)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 3)
ChemCatChem     Hybrid Journal   (Followers: 11)
Chemical and Engineering News     Free   (Followers: 24)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 88)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 28)
Chemical Physics Letters : X     Open Access   (Followers: 4)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 4)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 25)
Chemical Reviews     Hybrid Journal   (Followers: 267)
Chemical Science     Open Access   (Followers: 44)
Chemical Science International Journal     Open Access   (Followers: 1)
Chemical Technology     Open Access   (Followers: 71)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 23)
ChemInform     Hybrid Journal   (Followers: 9)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 31)
Chemistry & Industry     Full-text available via subscription   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 225)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 20)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 24)
Chemistry Central Journal     Open Access   (Followers: 5)
Chemistry Education Research and Practice     Free   (Followers: 8)
Chemistry Education Review     Open Access   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry Letters     Full-text available via subscription   (Followers: 49)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 339)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 20)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
ChemistrySelect     Hybrid Journal  
Chemistry–Methods     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
ChemNanoMat     Hybrid Journal   (Followers: 1)
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access   (Followers: 1)
ChemPhotoChem     Hybrid Journal  
ChemPhysChem     Hybrid Journal   (Followers: 14)
ChemPlusChem     Hybrid Journal   (Followers: 2)
Chempublish Journal     Open Access   (Followers: 1)
ChemSystemsChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal   (Followers: 1)
CHIMIA International Journal for Chemistry     Open Access   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 13)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Ciencia     Open Access   (Followers: 1)
Clay Minerals     Hybrid Journal   (Followers: 9)
Cogent Chemistry     Open Access   (Followers: 3)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 12)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 24)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)

        1 2 3 4 | Last

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Chemistry Africa : A Journal of the Tunisian Chemical Society
Number of Followers: 0  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2522-5758 - ISSN (Online) 2522-5766
Published by Springer-Verlag Homepage  [2658 journals]
  • Random Copolymerization of ε-Caprolactone and L-Lactide by Ring Opening
           Polymerization Using a Co/N-Doped Carbon Framework as Catalyst

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      Abstract: The synthesis and use of MOF-derived Co/NCF (N-doped carbon framework) material as a heterogeneous catalyst for copolymers synthesis via ring-opening polymerization (ROP) are reported for the first time. The Co/NCF material is applied for the copolymerization of L-lactides (LA) and ε-caprolactone (ε-CL) as monomers via ROP in bulk without any solvent or co-catalyst. The as-prepared catalyst is characterized using XRD, TPD, XPS, SEM, and TEM analytical techniques. At the same time, 1H and 13C-NMR spectroscopy were used to analyze the microstructure of the copolymer confirming the random copolymer structure. The average r values calculated from the heterodiad analysis of the 1H NMR, data were rLA = 0.96 and rCL = 0.93 and L value calculated from the triads analysis of 13C NMR, data were LLA = 3.17 and LCL = 2.79, respectively. It has been observed that the melting temperature and glass transition temperature of the copolymer increases with higher LA content. The XRD and DSC analyses also confirmed that the as-synthesized copolymer possesses two phases corresponding to the polylactide and polycaprolactone, respectively. Additionally, the activity of Co/NCF is also compared with other Co-based heterogeneous catalysts to demonstrate its ability. Graphic
      PubDate: 2021-10-16
       
  • Highly Specific and Rapid Colorimetric Detection of Tetracycline in Pills
           and Milk Based on Aptamer-Controlled Aggregation of Silver Nanoparticles

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      Abstract: Abstract Tetracycline (TET) residues exist in our lives and endanger our health. For rapid visual detection of tetracycline, we designed a TET colorimetric aptasensor based on aptamer (Apt) to control the aggregation of silver nanoparticles (AgNPs). Apt was adsorbed on the surface of AgNPs to protect the AgNPs from the influence of salt and maintained a dispersed state. The color of the solution was bright yellow. When TET was present, Apt desorbed from the surface of AgNPs and highly combined with TET to form a rigid structure. AgNPs without Apt protection aggregated under the induction of salt, and their color changed to pink. By comparing the three Apts of TET with different chain lengths, we found that the shortest Apt had the best effect on stabilizing AgNPs. The aptasensor constructed based on this mechanism was not only sensitive and fast. It is also highly specific and does not respond to substances similar to TET (chlortetracycline (CTC) and oxytetracycline (OTC)). Under the best conditions, the linear range was 40–480 nM, and the detection limit was 4.33 nM. This method is used in the detection of actual pills and milk samples, with high recovery rate and small relative error. This proves the potential of the aptasensor in food safety testing.
      PubDate: 2021-10-16
       
  • Monitoring of Parathion-Methyl Based on PtNPs Combined with
           4-Amino-3-Hydroxy-1-Naphthalenesulfonic Acid Fluorescent Probe and Enzyme
           Inhibition

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      Abstract: Abstract In this paper, a new fluorescence analysis method was proposed to detect parathion-methyl (PM) based on platinum nanoparticles (PtNPs) and 4-amino-3-hydroxy-1-naphthalenesulfonic acid (AHNSA) as fluorescent probe. AHNSA with high fluorescence could combine with PtNPs by electrostatic attraction, bringing out fluorescence quenching of AHNSA. Acetylthiocholine (ATCh) was hydrolyzed by acetylcholinesterase (AChE) to produce thiocholine, which could induce the aggregation of PtNPs by electrostatic attraction and restore the fluorescence intensity of AHNSA. However, in the presence of PM, the catalytic activity of AChE is inhibited, leading to the quenching of fluorescence of AHNSA again. Under the optimal conditions, the linear range of parathion-methyl (PM) detection was 0.26–53.3 ng/mL (R2 = 0.994), and the limit of detection was 0.17 ng/mL (S/N = 3). In addition, this method has been successfully used for the determination of PM in water and food samples.
      PubDate: 2021-10-11
       
  • Palladium Nanoparticles: Plant Aided Biosynthesis, Characterization,
           Applications

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      Abstract: Abstract Among diverse metal nanoparticles, palladium nanoparticles (PdNPs) have captured the special attention of researchers because of their unique applications. However, the synthesis of PdNPs by conventional procedures incorporates harmful solvents, reducing agents, and produces toxic pollutants and by-products. The plant part extract-assisted green synthesis of palladium nanoparticles has been known as the best solution to minimize the limitations of conventional methods. Bio synthesized nanoparticles have good selectivity and catalytic properties. Thus, they have been investigated as nanocatalysts in numerous catalyst based reactions. In this review article, we have explored the various plant parts responsible for the bioreduction of palladium ions, characterization of PdNPs and heterogeneous catalytic activity of PdNPs in the C–C coupling reaction. In addition, we reviewed a plausible mechanist approach for the fabrication of PdNPs.
      PubDate: 2021-10-11
       
  • Impact of the Illegal Gold Mining Activities on Pra River of Ghana on the
           Distribution of Potentially Toxic Metals and Naturally Occurring
           Radioactive Elements in Agricultural Land Soils

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      Abstract: Abstract Mining sectors in the developing world are located in villages, where farming is the prime source of income. This generates the likelihood of adverse spillovers to agriculturalists through rivalry for main inputs (i.e. land, labor, water, and environmental pollution). To explore this concern, gold mining sites on the Pra River of Ghana and nearby farmland soils were sampled and analyzed to evaluate the levels of potentially toxic metals (PTM) and naturally occurring radioactive elements (NORE) and appraise the potential ecological risk of PTM in soil samples. Cold vapor atomic fluorescence spectrometer was used to analyze the contents of total mercury (THg) while inductively coupled plasma-optical emission spectroscopy was used to determine the total concentrations of Ni, Cr, Pb, Co, Cu, Cd, Zn, and As. Instrumental Neutron Activation Analysis technique was used to detect the NORE concentrations in the soil samples. Geochemical indices were used to help evaluate the environmental risks. Toxic metals and radioactive elements concentrations in mining soil samples varied in the range: THg (0.37–0.59 mg/kg d.w.), As (4.68–19.69 mg/kg d.w.), Pb (6.67–23.02 mg/kg d.w.), Cd (0.103–0.315 mg/kg d.w.), Co (5.06–15.03 mg/kg d.w.), Cr (22.19–46.97 mg/kg d.w.), Cu (15.43–38.05 mg/kg d.w.), Ni (11.42–38.33 mg/kg d.w.), Zn (20.27–97.64 mg/kg d.w.), Al (34,739.33–51,037.07 mg/kg d.w.), Th (77.97–136.10 mg/kg d.w.), and U (< 34.14–102.31 mg/kg d.w.). The levels of PTM and NORE in farmland soil samples ranged from THg (0.09–0.49 mg/kg d.w.), As(0.45–7.01 mg/kg d.w.), Pb (3.01–7.01 mg/kg d.w.), Cd (0.01–0.10 mg/kg d.w.), Co (3.12–8.65 mg/kg d.w.), Cr (9.35–22.11 mg/kg d.w.), Cu (8.83–18.07 mg/kg d.w.), Ni (8.12–16.08 mg/kg d.w.), Zn (9.63–42.33 mg/kg d.w.), Al (23,011.65–34,110.71 mg/kg d.w.), Th (< 47.17–57.061 mg/kg d.w.), and U (< 34.14–42.99 mg/kg d.w.). High levels of NORE, THg, and As were detected in some of the farmland sites. Radioactive elements were enriched in all the soil samples detected, while THg, As, Co and Zn were enriched in some of the soil samples analyzed. Mercury exhibited a moderate level of monomial ecological risk in some farmland soil samples while the other PTMs showed low risk in all farmland soil samples. This study has proved that farmland soils contain concentrations of U, Th, THg, and As that can harm the eco-agrosystem and these hazardous elements can be transferred to humans and animals through the food chain process. It is believed that mining activities on the river and phosphate fertilizer applications on farmlands are the major influence.
      PubDate: 2021-10-06
       
  • Application of Unmodified Brachystegia spiciformis Leaf Biomass in the
           Adsorption of Nitrate Ions

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      Abstract: Abstract The application of Brachystegia spiciformis leaf powder in the adsorption of nitrate ions was conducted on both synthetic and real water samples. Optimum adsorption conditions for nitrate adsorption were pH of 4, equilibration time of 45 min, and biosorbent dose of 1.5 g. Batch adsorption was used in this study and nitrate ions were analyzed using the salicylic acid method. Non-linear adsorption isotherm fitting indicated that the experimental data was described well by the Langmuir model with a monolayer adsorption capacity of 5.97 mg/g. The Langmuir`s separation factor, \({R}_{L}\) , values were in the range, 0 < \({R}_{L}\)  < 1, indicating favorable interactions between nitrate ions and Brachystegia spiciformis leaf powder adsorbent. The pseudo first order model provided the best fit to the experimental kinetics data with an R2 value of 0.9880 and a rate constant of \(\left( {7.3 \pm 0.1} \right) \times 10^{ - 2}\)  min−1. The Brachystegia spiciformis leaf powder adsorbent achieved 100% and 78% nitrate ions removal from dam water and industrial effluent water respectively. We have shown that a cheap biomass adsorbent that has high activity towards nitrate ions adsorption can be produced and applied in the adsorption of nitrates from water.
      PubDate: 2021-09-29
       
  • Thermodynamics and Kinetic Investigation of Reaction of Acriflavine with
           L-cysteine in Aqueous Medium

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      Abstract: The kinetic investigation of reaction of 3,6-diamino-10-methylacridin-10-ium chloride (acriflavine) with l-cysteine in aqueous acidic medium at maximum absorption = 460 nm, ionic strength (I) = 0.1 mol dm−3 and temperature (T) = 307 K has been carried out spectrophotometrically. Using a pseudo first order approach, the rate of the redox reaction resulted to first order with respect to the [acriflavine, (AF)] and [l-cysteine, (CSH)] and second order total. Stoichiometric determination confirms that a mole of the acriflavine is consumed by a mole of l-cysteine at a time for the attainment of product formation. The reaction followed a one-way acid independence path. The adjustment in ionic strength (NaCl) and solvent polarity (water/acetone mixture) of the reaction system showed no reasonable effect and there was a fairly decrease in the reaction rate, respectively. The reaction rate is also characterised by neither catalysis nor inhibition of added ions. The negative magnitude of entropy of activation, \(\Delta\) S‡, (− 151.39 ± 031 J mol−1 K−1) and positive value of enthalpy of activation, \(\Delta\) H‡, (+ 31.378 ± 030 kJ mol−1) suggest that the reaction proceeds via an associative pathway and reasonable energy are needed to lower the activation energy for a tangible products formation. Two acridine unit products polymerised afterward forming a dimer as a result of an intramolecular coupling. A determinable intermediate has been observed through a spectroscopic test and confirmed by Michaelis–Menten’s plot. Based on Taube’s inorganic electron transfer reaction, an inner-sphere mechanistic pathway is implicated with a stable intermediate complex formation as shown below; Graphic abstract
      PubDate: 2021-09-29
       
  • Synthesis and Spectral, Electrochemical, Protein-Docking and Biological
           Studies of Fluoxetine Dithiocarbamate and Its Bivalent Metal Complexes

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      Abstract: A dithiocarbamate ligand, FLXDTC, has been synthesized from fluoxetine drug along with its complexes of some bivalent metal ions such as Zn(II), Cd(II), Hg(II), Co(II), Ni(II), Mn(II) and Cu(II). The ligand and the complexes have been characterized by various analytical and spectroscopic methods in addition to some voltammetry studies. The studies propose the formation M(FLXDTC)2 complex for all where M = Zn(II), Cd(II), Hg(II), Co(II), Ni(II), Mn(II) and Cu(II) ions. It is also found that Cu(FLXDTC)2 takes in more CuCl2 to result in a Cu2(FLXDTC)2Cl2 kind binuclear complex with sulfur atom bridges Antimicrobial, antioxidant, antifungal, anti-malarial and antitumor capabilities have been tested for both FLXDTC and M(FLXDTC)2 complexes. Molecular docking studies on Cu(FLXDTC)2 with the intercession of EGFR protein show good antimicrobial and antifungal activities. Biological studies of manganese and nickel complexes have shown excellent antioxidant activity with IC50 values of 11.29 ± 1.85 and 11.51 ± 1.38 μM. Three different cancer cell lines, viz., MCF-7, HepG-2 and HEK 293 have been subjected to the anticancer screening for FLXDTC and it metal complexes whereby it is revealed that Cd(FLXDTC)2 has greater activity against MCF-7 (IC50 = 23.08 ± 0.12 µM), HepG-2 (IC50 = 12.30 ± 0.25 µM) whereas Zn(FLXDTC)2 exhibits good anticancer activity against MCF-7 (IC50 = 28.63 ± 1.36 µM), HepG-2 (IC50 = 19.24 ± 1.04 µM). Graphic Fluoxetine dithiocarbamate (FLXDTC) and M(FLXDTC)2 have been synthesised and characterised and their biological activity and protein docking models presented.
      PubDate: 2021-09-29
       
  • Tetrabutylammonium Impregnated Chitosan for Adsorptive Removal of Harmful
           Carcinogenic Dyes from Water-Bodies

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      Abstract: The chitosan biopolymer was impregnated with quaternary ammonium salt tetrabutylammonium bromide to enhance adsorption capacity of the material. The synthesized material, tetrabutylammonium impregnated chitosan (TIC) was characterized using various spectral techniques such as Fourier Transform Infra-red spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) along with energy dispersive X-ray spectrum for elemental composition (EDAX), Thermo-gravimetric analysis (TGA-DTA) and pH point of zero charge (pHPZC). The pHPZC of the material was found to be 8.2 which indicated that both anionic as well as cationic dyes can be adsorbed on its surface. Thus TIC was employed as adsorbent for the removal of two dyes namely, malachite green (MG) and methylene blue (MB). The effects of operational parameters such as pH of dye solution, contact time, adsorbent dose, adsorbate concentration and temperature on the adsorption process were studied using batch adsorption method. The adsorption process was found to follow Freundlich isotherm model and maximum adsorption capacities were found to be 56.1 mg g−1 and 30.5 mg g−1 for MG and MB respectively at pH 8.5. Pseudo-second order kinetic model was found to be the best-fit model and thermodynamic studies showed that the process of adsorption is spontaneous and enthalpy driven in nature. Graphic abstract
      PubDate: 2021-09-24
       
  • Fabrication of sodium hydrogen sulfate onto silica from waste for biomass
           energy

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      Abstract: Abstract Processing of agro-waste into functional materials has caught the attention of scientist and technologist in recent times. The agro-waste can be used to generate energy and new functional materials. Different techniques were developed to generate new chemicals from the waste. Rice husk (RH) is one of the waste material produced from rice production. Two methods (direct burning and reflux) were developed to extract the silica (SiO2) from RH. The extracted silica was immobilized with sodium hydrogen sulfate. The resulting solid catalysts had specific surface area of 274, and 307 m2 gm−1 for the direct and reflux method respectively. The carbon and sulfur content was slightly higher in the catalyst prepared under reflux condition as compared with the direct method. The FT-IR showed that the functional groups on the catalyst were not changed in the products. The thermal and morphological studies did not show too many changes on the catalyst. The XRD pattern of the catalyst from the direct method show some crystallinity as compared with that produced by the reflux method. Both solid catalysts together with NaHSO4 (as a homogeneous catalyst) were used in the hydrolysis of cellulose. These catalysts were also used in the in-situ hydrolysis of glucose to other product. It was found that approximately 99% of cellulose was hydrolyzed to glucose at 120 ◦C in six hours.
      PubDate: 2021-09-14
       
  • Occurrence of Polycyclic Aromatic Hydrocarbons (PAHs) in the Lake Water at
           Grovnes Peninsula Over East Antarctica

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      Abstract: Purpose Polycyclic aromatic hydrocarbons (PAHs) are toxic and volatile in nature. They can persist for a long time in the environment. The aim of this work was to investigate the levels of PAHs and their diagnostic ratios in the samples of lake water of Grovnes peninsula, East Antarctica. Methods Total fourty five samples were collected from fifteen different lakes of the Northern & Southern Grovnes peninsula. Sixteen compounds of PAHs were estimated in the samples by GC–MS/MS (Gas chromatography-mass spectrometry) technique. Results PAHs levels were found from 10.33 to 44.35 pg ml−1 in the lake water samples. Fluorene was detected in all fifteen different lakes. The highest concentration of fluorene was found in the L7BNG lake. PAHs diagnostic ratios were found in the range of 0.76–4.68 for ∑LMW/∑HMW, 0.44–0.80 for FL/(FL + PYR), 1.00 for ANT/(ANT + PHE), 0.37–0.58 for FLA/(FLA + PYR), 0.44–0.47 for BaA/(BaA + CHR) in all fifteen different lakes. Conclusion The present study confirms the presence of PAHs in a small amount in Grovnes peninsula, East Antarctica. The presence of additional pollutants should be investigated in order to comprehensively assess the scale of environmental pollution in Antarctica.
      PubDate: 2021-09-13
       
  • Spectroscopic Analysis of Chemical Compounds Derived from the Calcination
           of Snail Shells Waste at Different Temperatures

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      Abstract: Abstract Biogenic calcium carbonate (CaCO3) has attracted great attention in multiple applications. This study investigates the influence of different calcination temperatures (200–1000 °C) on the morphology and the structure of snail shells waste. The different chemical compounds obtained were characterized by scanning electron microscope (SEM), energy dispersive X-ray analyzer (EDXS), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy (Raman). The identified particles for raw and calcined SSP at 200 °C were aragonite polymorphs, calcite for 400–600 °C and calcium oxide (CaO) for 800–1000 °C. The endothermic decomposition of the CaCO3 phase to CaO occurs in the temperature range of 668–870 °C. The transformation takes along with a loss of about 40% of the initial weight of the sample due to the CO2 release. Ca–OH bond was revealed in FT-IR spectra at calcination ≥ 700 °C. It was caused by the reaction of CaO with H2O in atmospheric air. The preparation of CaO from snail shells waste as the primary source is environmentally sustainable. Snail shells based CaO can potentially be exploited for various applications, especially for catalyst, wastewater treatment and biomedical.
      PubDate: 2021-09-12
       
  • Biological Studies on Anthra[1,9-cd]pyrazol-6(2D)-one Analogues as
           Anti-vascular Endothelial Growth Factor Via In silico Mechanisms

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      Abstract: Abstract Breast cancer still remains one of the dangerous ailments among women globally. The havoc caused by this disease has drawn the attention of many researchers which are intensely seeking for a lasting solution to this malignant neoplasia. Thus, anti-VEGF activities of twenty-six anthra[1,9-cd]pyrazol-6(2d)-one derivatives were investigated via in silico method. The obtained descriptors proved the that studied compounds have a drug-like properties. The studied and the proposed compounds proved to be effective against VEGF than the referenced drug. Also, 7-(benzylamino)dibenzo[cd,g]indazol-6(2H)-one (12) with − 6.8 kcal/mol and proposed compound D (2-amino-7-fluorodibenzo[cd,g]indazol-6(2H)-one) (− 6.4 kcal/mol) have better ability to inhibit VEGF than other studied compounds. ADMET properties of the selected compounds were observed and reported.
      PubDate: 2021-09-09
       
  • Contamination and Hazard Risk Assessment of Potentially Toxic Elements in
           Road Dust Lagos, Southwest, Nigeria

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      Abstract: Abstract The purpose of this study was to determine the concentration, sources of pollution and health risks associated with 16 potentially toxic elements (PTEs) in 120 urban road dust samples in the city environ of Lagos, southwest, Nigeria. For all road dust samples, Zn, Se, Mo, Ag, Cd and Pb were higher than background values as defined by Upper Continental Crust (UCC) values, whilst 50, 96, 3, 20, 20, 5 and 5% of the samples showed higher values for U, Cu, V, As, Cr, Ti and Fe, respectively. The spatial distribution maps showed that pollution hotspots for Pb, Zn, Cu, Cr, Se, Ag, Cd and Mo were concentrated in densely populated areas with a high volume of traffic and industrial areas such Ikeja, Ojo, Alimosho and Kosofe regions. Ninety five percent of the samples provided a Pollution Load Index (PLI) greater than 1, indicating the presence of pollution inputs. The calculated Contamination Degree (CD) was between 10–174 for PTE’s with an average of 58, exhibiting a moderate to very high degree of contamination. The potential ecological risk index (RI) ranged from 39 to 3496, with a mean value of 678 where 7% of the samples provided a low ecological risk index, 5% a moderate risk, 34% and 38% a considerable and very high ecological risk. The non-carcinogenic health risk index showed that Mo, Pb and Co accounted for 87% of the Heath risk index value for both children and adults with a low to moderate exposure risk following the order: dermal > ingestion > inhalation. The carcinogenic risk showed that Ni posed no carcinogenic risk in the dust, Co and As were within low risk, Pb and Cd posed a low and moderate carcinogenic risk to both children and adults in the study area. Road dusts from industrial and densely populated residential areas with high traffic influx exhibited a higher pollution and health risk index compared to less densely populated residential areas in Lagos. This confirmed vehicular traffic as the main source of the PTEs in the dust samples of the study area.
      PubDate: 2021-09-06
       
  • A Computational Exploration of Ammonia Adsorption on the Kaolinite Clay
           Surface

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      Abstract: The adsorption mode of ammonia on the (001) surface of kaolinite was explored using the periodic DFT/PBE-D3 method. The thermodynamics and electronic properties such as adsorption energy, bond lengths and density of states were calculated to investigate the adsorption mechanism. Calculated adsorption energies were negative for ammonia-kaolinite complexes indicating a favorable exothermic process. The corrections of the van der Waals dispersion play an important role in stabilizing ammonia-kaolinite interactions. The maximum surface coverage is found to 4.3 molecules/nm2. The geometric parameters, Bader charges and PDOS analysis results showed that ammonia is adsorbed on the surface (001) of kaolinite clay by a hydrogen bond, mainly through the electrostatic interaction between the hydroxyls group of the surface and the nitrogen atom of NH3 molecule. The analysis of the computed infrared spectra of free and adsorbed NH3 highlights the impact of adsorption on its characteristic stretching and bending modes. Graphic
      PubDate: 2021-09-04
       
  • Preliminary Study of the Effects of Some Antioxidants on the Physical and
           Flow Properties of Agbabu Natural Bitumen

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      Abstract: Abstract Road pavements constructed from neat or unmodified bitumen are usually limited by reduced performance and short service life arising from the high susceptibility of neat bitumen to oxidative degradation. To mitigate against these problems, neat bitumen is often modified by incorporating some materials that can increase its performance and reduce oxidative ageing. A preliminary investigation on the effects of some antioxidants (Vitamins C, K, and E) on the physical and flow properties of Agbabu Natural Bitumen (ANB) was carried out. Vitamin-modified ANB samples were prepared using the melt blend technique. This was achieved by mixing vitamin with the purified ANB which has been heated to fluid state in a stainless reactor, in the following ratios [(w/w %): 2%, 4%, and 6%)]. Three bituminous binders were successfully prepared for each antioxidant by varying amounts of antioxidants into bitumen. (i.e.2%, 4% and 6% w/w). Vitamin C-, E- and K- modified ANB were successfully developed and characterized for their physical and flow properties. Each of the vitamins has an increasing effect on softening point, kinetic viscosity, and penetration index of the neat ANB but a decreasing effect on the penetration point. The changes recorded in the modified samples imply an improvement in the physical and flow properties of ANB. The study underscores the potential application of vitamins as suitable additives for ANB modification to improve its durability in road pavements. Comparison of the three vitamin-modified ANBs produced, on basis of their physical and flow properties, showed that vitamin C- modified ANB has the highest potential of being a suitable modifier for bitumen that can be used in road pavement in a hot climate environment. However, the ageing characteristics of these vitamin-modified ANB produced need to be carried out.
      PubDate: 2021-09-01
       
  • Influence of Processing Parameters and PYTHON Based Image Analysis for
           Quantification of Carcinogenic Acrylamide in Potato Chips

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      Abstract: Abstract Acrylamide (AA), a toxic compound and potential carcinogen, which forms at elevated heating of starchy food stuffs through the Maillard reaction. Thus, the identification and quantification of AA in the fried starchy food stuffs is of great importance in order to prevent cancer causing possibilities. The primary objective of this research was to investigate the effect of frying conditions and utilize PYTHON programming language to quantify the AA content on the Potato Chips (PCs). The PCs were prepared by frying at different time intervals and duration. The digital images of PCs were captured and used to extract significant browning parameter. Here, we employed image processing technique with PYTHON module to quantify the AA content on the PCs. In addition, we studied the influence of frying conditions concerning to the formation of AA, by varying the temperature and duration. As-prepared PC samples’ water content decreased and ash content increased with respect to the enhancement of frying temperature and duration. For image processing, the captured PCs images were subjected to pre-processing in terms of object segmentation, region of interest and feature extraction to quantify the AA content, precisely. The lowest AA content was observed as 0.26 µg/g, and the highest AA content was observed as 4.75 µg/g on the PCs. The results of this study showed that the small/large scale fried starchy food stuffs companies can utilize this cost-effective technique to quantify the AA content in their products.
      PubDate: 2021-09-01
       
  • Anti-tyrosinase and Anti-butyrylcholinesterase Quinolines-Based Coumarin
           Derivatives: Synthesis and Insights from Molecular Docking Studies

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      Abstract: Abstract In this work, a series of anti-tyrosinase and anti-butyrylcholinesterase coumarin derivatives 4a–f and 5a–f were synthesized starting from 4-hydroxycoumarin. The condensation of 2-(arylimin)-4-hydroxycoumarins 3a–f with dimethylformamide dimethyl acetal (DMF-DMA), used as a key reaction, afforded the precursors 4a–f, whose acid treatment led to the formation of 5a–f. These prepared heterocycles were characterized by spectroscopic means including 1H-NMR, 13C-NMR, and DCI-HRMS. Their anti-tyrosinase and anti-butyrylcholinesterase activities have been evaluated in vitro and some of them exhibited promising activity supported by the molecular docking analysis to estimate possible interactions between these compounds and active sites of both proteins tyrosinase (PDB: 2Y9W) and butyrylcholinesterase (PDB: 4TPK).
      PubDate: 2021-09-01
       
  • Isosalipurposide: A Promising Analgesic, Anti-inflammatory and
           Gastroprotective Agent Isolated from the Flowers of Acacia cyanophylla

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      Abstract: Abstract The importance of the Acacia genus is due to its usage in nutrition, and in folk and modern medicine. They are considered as promising sources of bioactive metabolites displaying beneficial to human health. The chemical and biological investigation of some Acacia species helped in the design of food supplements and drugs. A. cyanophylla has been introduced in Tunisia mainly to rehabilitate rangelands, especially in semi-arid areas, and also as a potential forage resource during periods of drought. The aim of this study was to investigate, in vivo, the analgesic, anti-inflammatory and gastroprotective potentials of the EtOAc extract and one of its major glycoside constituents, isosalipurposide (1), from the flowers of A. cyanophylla. The gastroprotective activity was evaluated using HCl/EtOH induced gastric ulcers in rats. The EtOAc extract exhibited interesting gastroprotective, analgesic and anti-inflammatory activities in a dose-dependent manner. Similarly, isosalipurposide (1) displayed promising anti-inflammatory and analgesic potentials and showed a protection of stomach against ulcer induced by HCl/EtOH. These data suggest that the pharmacological potential of the EtOAc extract could be mainly due to its main component isosalipurposide (1), which leads to conclude that the flowers of A. cyanophylla may be a possible source for the quantitative isolation of a pharmacoactive compound of interest.
      PubDate: 2021-09-01
       
  • Evaluation of Phenolic Constituents and Toxicity of Lycophytes and Ferns
           of Shervarayan Hills Aqueous Extracts

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      Abstract: Abstract The present study was aimed to reveal the phenolic composition and toxicity of Shervarayan Hill lycophytes and ferns aqueous extracts. The total phenolic, tannin and flavonoid content of selected lycophytes and ferns aqueous extracts were determined. To reveal the toxicity of Shervarayan Hill lycophytes and ferns different concentrations (100, 250, 500, 750 and 1000 µL/mL) of the aquoues extracts were taken. The Brine Shrimp Lethality Assay (BSLA) was employed for the toxicity studies. The results revealed that varied quantity of total phenolics, tannins and flavonoids presence in the studied lycophytes and ferns aqueous extracts. A dose dependent toxicity was observed in all the studied ferns aqueous extract. The toxicity of studied ferns of Shervarayan Hills showed varied mortality rate and the LC50 values ranged from 168.6 to 1634.1 µg/mL. The correlation of all the studied ferns of Shervarayan Hills was significant at the 0.01 level (2-tailed) except Cyathea nilgirensis, Anemia wightiana and Lycopodiella cernua. The test of significance analysis confirmed the sigificance the metabolites concentration and toxicity (t = 0.000). The ANOVA analysis is confirmed the mean difference is significant at the 0.05 level. For the toxicity studies 44 lycophytes and ferns of Shervarayan Hill were included, of which 12 were considered as non-toxic, 17 were considered as low toxic, 15 were considered as medium toxic. The phytochemical and toxicity analysis suggested that the lycophytes and ferns of Shervarayan Hill are rich with biological properties; further study may bring out the active principles with anti-oxidant, anti-microbial, anti-inflammatory and anti-cancer properties.
      PubDate: 2021-09-01
       
 
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