Surface Area Values Research Articles

Layered MOF supported on 2D delaminated MXene (Mo2Ti2C3) nanosheets boosted water splitting.

Metal organic frameworks (MOFs) have a porous structure, high surface area, and high charge transfer, and they have been regarded as model electrocatalysts. Optimization of the electrocatalytic activity of MOFs is challenging, and an effective strategy for this optimization is the construction of a well-defined interfacial bond bridge. In this work, an in situ approach of composite synthesis is reported for MOF (CoNiNH2BDC) with MXenes (Mo2Ti2C3), as the electrocatalytic properties of MOF can be greatly enhanced with the incorporation of the conductive material MXene. The prepared composite material was characterized thoroughly using XRD, XPS, FESEM, EDX, TEM, and BET. The synergistic effect of both components of this composite material resulted in enhanced conductivity and the number of active sites, which led to enhanced electrocatalytic performance. The CoNiNH2BDC MOF with different ratios of Mo2Ti2C3 MXene were synthesized, and the resulting materials were evaluated for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities. It was observed that the MOFMX3 attained a 10 mA cm-2 current density at 1.44 V for OER and -0.037 V for HER (vs. RHE), and lower values of Tafel slopes of 44.8 mV dec-1 for OER and 45 mV dec-1 for HER in 0.1 M KOH were achieved. The higher double layer capacitance (C dl) values lead to high electrochemical surface area (ECSA) values. Lower Tafel slope values for MOFMX3 show that the presence of MXene nanosheets in the hybrid provides support to the layered and porous configuration of MOF, and the chances of the interaction of electrolyte to the catalytically active sites are significantly enhanced. This work highlights the idea of growing bimetallic MOFs on Mo2Ti2C3 MXene using an interdiffusion reaction strategy and opens up an avenue for designing highly electrocatalytic systems.

Microscopic molecular mobility of high-performance polymers of intrinsic microporosity revealed by neutron scattering - bend fluctuations and signature of methyl group rotation.

Polymers of intrinsic microporosity exhibit a combination of high gas permeability and reasonable permselectivity, which makes them attractive candidates for gas separation membrane materials. The diffusional selective gas transport properties are connected to the molecular mobility of these polymers in the condensed state. Incoherent quasielastic neutron scattering was carried out on two polymers of intrinsic microporosity, PIM-EA-TB(CH3) and its demethylated counterpart PIM-EA-TB(H2), which have high Brunauer-Emmett-Teller surface area values of 1030 m2 g-1 and 836 m2 g-1, respectively. As these two polymers only differ in the presence of two methyl groups at the ethanoanthracene unit, the effect of methyl group rotation can be investigated solely. To cover a broad dynamic range, neutron time-of-flight was combined with neutron backscattering. The demethylated PIM-EA-TB(H2) exhibits a relaxation process with a weak intensity at short times. As the backbone is rigid and stiff this process was assigned to bend-and-flex fluctuations. This process was also observed for the PIM-EA-TB(CH3). A further relaxation process is found for PIM-EA-TB(CH3), which is the methyl group rotation. It was analyzed by a jump-diffusion in a three-fold potential considering also the fact that only a fraction of the present hydrogens in PIM-EA-TB(CH3) participate in the methyl group rotation. This analysis can quantitatively describe the q dependence of the elastic incoherent structure factor. Furthermore, a relaxation time for the methyl group rotation can be extracted. A high activation energy of 35 kJ mol-1 was deduced. This high activation energy evidences a strong hindrance of the methyl group rotation in the bridged PIM-EA-TB(CH3) structure.

Advanced Pore Structure Analysis of Silver Nanoparticles via Electron Microscopy: Implications for Functional Optimization

In this paper, quantitative analysis of the pore structure of AgNPs is presented by combined analysis of advanced electron microscopy techniques. The synchrotron-based analysis of silver nanoparticles with 18-30 nm in size confirmed detailed information about the internal structure of their porous nature of the nanoparticles and their surface characteristics. Although the pore volume of AgNPs changed from 28 nm³ to 40 nm³, pore size ranged between 3 nm to 10 nm. Specific pore volume values referring to AgNP mass were within 10–26 nm 2 /g depending on nanoparticle size. Furthermore, the surface area values varied between 25 m²/g and 50 m²/g evidencing the influence of nanoparticle size on internal as well as exterior surface area. Taken together, the findings suggest a direct dependency of size dependent nanoparticle on the pore structure and surface area of the support material: Diameter of AgNP has direct impact on porosity of the samples. These findings are useful for optimizing internal porosity and surface properties of AgNPs for particular uses such as catalysis, drug delivery, and sensing. This vast study provides a framework for synthesising AgNPs with any types of pore structures to improve nanotechnology applications through careful tailoring of materials.

Anthropometry and Physical Characteristics of Indian Badminton Players

Introduction: Badminton is a fast-paced racket sport characterized by high-intensity intermittent actions interspersed with rest intervals. The role of anthropometry is critical in assessing athletes since the physique, body composition, physical growth, and one’s motor development are fundamental for optimal performance. Methods: 32 badminton players' anthropometry data was collected using ISAK protocol. Fat and fat free mass percentages were calculated using existing formulas. Results: Significant differences were observed across gender in body surface area, body density, fat mass, and fat free mass values. Body surface area, body density, and fat free mass and percentages are higher in male players and fat percentage and fat mass values are higher in female players. Conclusion: The average height of Indian players is less compared to other international players, whereas the fat percentage of both male and female players is relatively higher.

In English

Comparative characterization of the particulate morphology and texture of various silicas (fumed silicas, silica gels, ordered mesoporous silicas) and carbons (chars and activated carbons, AC) is of interest from both theoretical and practical points of view since it allows one better understanding of advantages and disadvantages of various adsorbents upon their interactions with different adsorbates, co-adsorbates, and solutes in various dispersion media. Complete characterization needs application of a certain set of methods that is analyzed in the present paper. It is shown that the main difference in the textural characteristics of silica and carbon adsorbents is due to the absence (silicas) or presence (carbons) of nanopores in nanoparticles (NP). A great contribution of these pores in strongly activated carbons provides the specific surface area values greater by an order of magnitude than that of fumed silicas. Despite a high activation degree of AC, contribution of closed pores or pores inaccessible for nitrogen molecules remains relatively large in contrast to fumed silica A–300 composed of nonporous nanoparticles synthesized in the flame at higher temperature (~80% of melting temperature, Tm, for amorphous silica) than carbon activation temperature (~25%of Tm for carbons). Therefore, the pores inaccessible for nitrogen molecules in fumed silica could be attributed to narrow voids around contact area between neighboring NP in their aggregates, but for AC, there are both closed pores and open nanopores inaccessible for nitrogen molecules. For complete characterization of the morphology and texture of various adsorbents, such methods as transmission and scanning electron microscopies, probe (nitrogen, argon) adsorption, smallangle X-ray scattering (SAXS)and X-ray diffraction (XRD)could be used with appropriate software to analyze the data. The latter is especially important for the analyses of indirect data (e.g., adsorption, SAXS, XRD) characterizing the materials.

The Effect of Pre-washing Process with NaOH Solution on the Surface Area in Activated Carbon Production

The alkaline pre-washing process in the production of activated carbon is an important step and a factor that affects the characteristics of activated carbon. Alkaline pre-washing is used to optimize the surface properties of activated carbon, increase its adsorption capacity, and remove unwanted substances.
 
 In this study, hazelnut shells were selected as the raw material for producing activated carbon. ZnCl2 was used for chemical activation, and physical activation was carried out at 650 °C. However, prior to the chemical activation process, a pre-washing process with NaOH solution was applied to remove acidic groups present in the raw material. The structural properties of the activated carbon obtained from samples subjected to the pre-washing process and those without the pre-washing process were determined using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) for surface morphology, Brunauer-Emmet-Teller (BET) for pore size analysis, and Thermogravimetric Analysis (TGA) for temperature-dependent mass loss.
 
 The surface area of the activated carbon produced without pre-washing with NaOH solution was found to be 770 m²/g, with a carbon content of 87.10% by weight. After the pre-washing process with NaOH solution and subsequent chemical and physical activation, the surface area of the activated carbon increased to 1935 m²/g, with a carbon content of 95.51% by weight. Therefore, subjecting the raw material to the pre-washing process with NaOH solution not only increased the carbon content but also increased the surface area value by approximately 2.5 times.

Natural clays as adsorbents for the efficient removal of antibiotic ciprofloxacin from wastewaters: Experimental and theoretical studies using DFT method

Natural clays were used as adsorbent to remove ciprofloxacin from aqueous solutions by adsorption. The textural, structural, and morphological properties were examined, finding low-moderate specific surface area values (9.9–50.1 m2g−1) and a structure coincident with the smectite phase. Adsorption kinetic studies revealed that clay 3 and 4 reached a CIP removal around 70–80 % in 7–8 h. Elovich and pseudo-second-order models were the most suitable to describe the kinetics. The highest equilibrium adsorption capacities (qe = 150.2–193.7 mg g−1) were obtained for clay 1, 3, and 4; the lowest (qe = 30.6 mg g−1) was found for clay 2, which showed the highest-ordered structure. The Freundlich adsorption model led to the best-fitting results. From pH studies, working at solution pH = 4.0 led to the best adsorption results. The estimated thermodynamic parameters suggested that the adsorption process can be considered of physical nature. It was found that the high concentration of CO32– salts in the hospital wastewater effluent enhanced the CIP adsorption capacity, showing a CIP removal of about 95 % for the clay 3. Therefore, the adsorbent with the greatest compromise situation among all the variables was clay 3, presenting the maximum CIP removal after 7 h at pH 4.0, 50 °C and real matrices. The reusability of natural clays can be successfully regenerated by NaOH treatment using the adsorption/desorption process, an indication of its excellent reusability and stability during the regeneration. Finally, DFT molecular studies were performed to clarify the particularities of the adsorption of CIP onto clays.

Natural sapogenins as potential inhibitors of aquaporins for targeted cancer therapy: computational insights into binding and inhibition mechanism

Aquaporins (AQPs) are membrane proteins that facilitate the transport of water and other small molecules across biological membranes. AQPs are involved in various physiological processes and pathological conditions, including cancer, making them as potential targets for anticancer therapy. However, the development of selective and effective inhibitors of AQPs remains a challenge. In this study, we explored the possibility of using natural sapogenins, a class of plant-derived aglycones of saponins with diverse biological activities, as potential inhibitors of AQPs. We performed molecular docking, dynamics simulation and binding energy calculation to investigate the binding and inhibition mechanism of 19 sapogenins against 13 AQPs (AQP0-AQP13) that are overexpressed in various cancers. Our results showed that out of 19 sapogenins, 8 (Diosgenin, Gitogenin, Tigogenin, Ruscogenin, Yamogenin, Hecogenin, Sarsasapogenin and Smilagenin) exhibited acceptable drug-like characteristics. These sapogenin also exhibited favourable binding affinities in the range of −7.6 to −13.4 kcal/mol, and interactions within the AQP binding sites. Furthermore, MD simulations provided insights into stability and dynamics of the sapogenin-AQP complexes. Most of the fluctuations in binding pocket were observed for AQP0-Gitogenin and AQP4-Diosgenin. However, remaining protein–ligand complex showed stable root mean square deviation (RMSD) plots, strong hydrogen bonding interactions, stable solvent-accessible surface area (SASA) values and minimum distance to the receptor. These observations suggest that natural sapogenin hold promise as novel inhibitors of AQPs, offering a basis for the development of innovative therapeutic agents for cancer treatment. However, further validation of the identified compounds through experiments is essential for translating these findings into therapeutic applications. Communicated by Ramaswamy H. Sarma

Preparation and Characterization of Red Mud-Based Geopolymer Composited with Rice Husk Ash for the Adsorption of Bromocresol Green in Aqueous Solution

Geopolymer-based industrial waste as red mud (RM) was successfully obtained in the presence of different loadings of rice husk ash (RHA). During the preparation, the added amounts of RHA in the geopolymer composition were varied from 10 to 50 % when the mass ratio of binder solution (Na2SiO3) and activated alkali-metal solution (NaOH 7 M) were 2.5 and the curing condition was fixed at 333 K within 24 h. For characterization, the surface morphology was evaluated by scanning electron microscope (SEM) equipped with the energy-dispersive X-ray, which detected the distribution of elements before and after the geopolymerization. To indicate the formation of geopolymer, Fourier–transform infrared spectroscopy (FT-IR) was used. The effect of the loading amounts of RHA on the Brunauer–Emmett Teller (BET) surface area value and Barrett–Joyner–Halenda (BJH) pore size of the obtained geopolymers were determined using a nitrogen gas adsorption instrument. In the bromocresol-green (BG) adsorption performed at pH 2, the higher addition of RHA in the geopolymer composition enhanced the adsorption capacities within 180 minutes. In addition, the adsorption behavior of the mixed geopolymer to BG fits well the Langmuir model, indicating that the adsorption occurs on the homogeneous monolayer surface of geopolymer. From this study, the RHA could be a natural potential filler to improve the BG-uptake of RM-based geopolymer in wastewater treatment.

Electrochemical Polymerization of a Novel Thiophene-Derived Monomer and Its Use as Support Material for Methanol Oxidation

This research, conductive polymer supported modified electrode system which was prepared for usage in direct methanol fuel cells. To test the behavior of these electrode system for methanol oxidation, cyclic voltammetry (CV), chronoamperometry (CHR) and electrochemical impedance spectroscopy (EIS) methods were used as electrochemical methods. As the working electrode, pencil graphite electrode (PGE) was preferred because of its porous structure, good ion conductivity, practicality in application and ease of preparation and obtaining. Thiophene derivative 4,4')-2,2'-(diazen-1,2 diylbis(4,1 phenylene))bis(4 (thiophene-2-ylmethylene) oxazol-5(4H)-one), (DiAzBiPhBiTyOx) monomer was prepared and electrochemically polymerized by CV method in 0.01M TBAP and 0.05 HClO4 containing ACN solution on the surfaces of PGE. The spectroscopic characterization of the synthesized monomer was performed by NMR spectroscopy. Optimum polymerization conditions of monomer was determined according to scanning rate, potential range and acid density. The obtained modified electrode system (PGE/PDiAzBiPhBiTyOx) was doped with chloroplatinic acid hexahydrat-Pt2Cl6.6H2O (Pt) at different densities and the optimum catalyst density was determined as 3.25mM (PGE/3.25mMPt@PDiAzBiPhBiTyOx). The methanol oxidation performances of conductive polymer film, platinum and conductive polymer supported platinum catalyst systems were investigated separately. While the methanol oxidation responses of the conductive polymer film and platinum are almost similar, the methanol oxidation response of the platinum doped conductive polymer film catalyst system is higher. The modified electrode characterization was performed by CV, CHR and EIS methods. Furtheremore obtained modified electrode systems were characterized by FESEM/EDS, XRD to confirm the structures and morphologies. Also, the theoretical values such as electrochemical surface area (ECSA) and specific capacitance (Cs) were calculated in aqueous acidic solution with and without methanol. Cs values of the PGE/3.25mMPt@PDiAzBiPhBiTyOx electrode in aqueous acidic solution with and without methanol were 3.861 and 3x10-4Fg-1 respectively. Also, the electrochemical surface area values of the same electrode in aqueous acidic solution with and without methanol were 196.437 and 21.150m2g-1 respectively.

Sustainable Lignin-Based 3D Porous Carbon Nanofibers As a Na-Ion Battery Anode

Rechargeable lithium-ion batteries (LIBs) have been increasingly popular in recent years in response to the growing need for large-scale energy storage applications and systems. However, due to the scarcity of lithium resources and their unequal distribution in the earth's crust, the present energy crisis has encouraged research into producing greener and more sustainable alternatives. Due to the relatively high abundance of sodium compared to lithium, sodium-ion batteries (SIBs) raise hope as an alternative and more sustainable chemistry.[1] Unfortunately, it is typically found that anode materials for LIBs are not suited for SIBs. Graphite, which is frequently used as an anode material in commercial LIBs, is incapable of achieving efficient Na+ insertion/extraction due to a lack of interlayer spacing (Na+ has a radius 39% bigger than Li+) and high energy involved in the formation of Na-C bonds..[2] So, to develop mechanically flexible electrode materials that combine high electrochemical performance with low-cost is still a challenge for its applications in a world subjected to severe shortage of resources and various environmental issues. The problem can be solved by selecting "green" and economically viable precursors and synthesis procedures. Carbon nanofibers derived from renewable biomass materials exhibit great potential as electrode materials with obvious cost and environmental benefits. Lignin, a heterogeneous and amorphous polymer found in many plants, and it is estimated that annual natural lignin production is 5-36×108 tons, of which more than 70 million tons are commercialized mainly from the paper industry as a by-product, is a possible choice as the precursor for carbon nanofibers due to its low cost and bio-renewable nature.In this work, mechanically flexible and 3D interconnected lignin/polylactic acid (PLA) carbon nanofibers with different amounts of lignin were prepared by electrospinning, then stabilized and carbonized. The obtained carbon nanofibers were characterized by scanning electron microscopy and transmission electron microscopy to investigate their morphology. To determine the carbon yield thermogravimetric analysis has been performed. Surface area, pore radius and volume values were obtained by performing BET analysis from N2 sorption isotherms. The obtained carbon nanofibers were tested as anode materiasl in 1 mol/L NaCF3SO3 in diethylene glycol dimethyl ether (DEGDME) electrolyte. Results show that lignin derived carbon nanofibers deliver a high reversible capacity of 330 mAhg-1 at the current density of 100 mAg-1 in the first cycle. Additionally, these carbon nanofibers showed excellent cycling and high-rate performance and maintained a capacity of up to 200 mAhg-1 for over 200 cycles. It is therefore, demonstrated that lignin derived carbon nanofibers prepared under appropriate conditions are promising anode material candidates for sodium-ion batteries.

Triazine‐based mesoporous organic polymers as palladium supports: physicochemical properties, porosity and catalytic performance in Suzuki coupling reaction

AbstractThis article reports the preparation of new mesoporous triazine‐based organic polymers and their characterization. The polymers were synthesized via a nucleophilic condensation reaction between cyanuric chloride and bisphenols or aromatic diamine linkers. As a result, two types of triazine‐based polymers were prepared: triazine‐ether and triazine‐amine polymers. The polymers reveal a mesoporous nature with surface area values ranging between 345 and 1275 m2 g−1 and mesopore volume between 0.273 and 1.03 cm3 g−1. These values were determined from argon gas isotherms at 87 K. The pore size distribution also confirmed the micro–mesoporosity, which reached up to 3.0 nm for all polymers. The triazine‐amine polymer shows good thermal oxidative stability up to 450 °C. Motivated by the mesopore size, the new polymers were also employed as palladium nanoparticle supports. The X‐ray diffraction technique indicated the successful incorporation of palladium nanoparticles, and Fourier transform infrared measurements proved that the framework of the polymers was retained after forming palladium supports. To ensure the catalytic reactivity of palladium nanoparticles, we employed one example as a catalyst in a Suzuki coupling reaction. The catalyst exhibited remarkable recyclability, maintaining catalytic efficiency through seven cycles, thereby enabling the use of palladium‐loaded triazine‐based polymeric catalysts in a variety of organic reactions in future. © 2023 Society of Industrial Chemistry.

Integral evaluation of effective conversion of sewage sludge from WWTP into highly porous activated carbon

Urban sewage sludge (SL) is a major concern due to the number of environmental problems it causes. Its application for different purposes is strictly regulated, limiting the possibilities of recycling and reusing this material. Thus, in this work, a complete study of a simple method to convert SL into activated carbon (AC) was carried out. The comprehensive study involves an evaluation of the main process parameters, such as the activating agent (AA) content (25 %, 33 %, 50 %), using the lowest amount of AA as novelty, different pyrolysis temperatures (600 and 800 °C), and purification conditions (6 M HCl:AC ratio, v:w). Under controlled and optimised conditions and through a single combined activation and pyrolysis step followed by acid purification, ACs with well-developed porosity can be obtained. Surface area values of around 870 m2/g and over 60 % carbon content were achieved, demonstrating that the prepared ACs could have applications in a wide variety of fields as high-value products. As an innovative aspect in this research, the gases streams and liquid effluents generated during the global process were analysed, achieving elimination of over 63 % of the concentration of the chemical elements contained in the SL during the chemical purification stage. Finally, mass, energy, and economic balances were carried out to estimate the production cost of AC derived from SL (<€ 8/kg AC).

Ethyl palmitate decarboxylation using colloidal SiO2- templated mesoporous Ni-ZrO2 catalysts

A series of 10 wt% NiO-xSiO2-ZrO2 (x = 0–30 wt%) catalysts were synthesized using a one-pot coprecipitation method with different of colloidal SiO2 contents, as a hard template, in order to imprint mesoporous cavities after a post-synthesis selective alkaline NaOH/H2O lixiviation. The final catalysts were characterized by XRD, HRTEM, textural measurements, 29Si-MAS NMR, FTIR, and XPS; the lixiviated, calcined and H2-reduced powders, were evaluated in the decarboxylation (DCO2) of ethyl palmitate as a liquid-solid phase model reaction at 300 °C, and 20 kg/cm2 H2 pressure. Optimal amount of colloidal SiO2 was 10 wt%. SiO2 effect (as colloid in fresh preparations and/or residual SiO2, after lixiviation) on ZrO2 is twofold. (i) to upgrade mesoporosity and (ii) to stabilize the porous structure. Residual SiO2 (from incomplete lixiviation) plays a beneficial role as examined by 29Si-NMR, being chemically bonded to ZrO2 and acting as props of the mesopores. Total pore volume and specific surface area values increased 5 and 6 times, respectively, when using a 30 wt% SiO2 in comparison with a non-silicated NiO-ZrO2 preparation. DCO2 of ethyl palmitate benefit from better mesoporosity and a great number of oxygen vacancies from Ni isomorphic substitution into cubic ZrO2 (as indicated by XPS); being at the origin of the reaction mechanism. For instance, a 10 wt% SiO2 NiO-ZrO2 catalyst is 1.6 times more selective (to n-pentadecane) and 1.2 times more active than a non-silicated NiO-ZrO2, yielding decarboxylated (i.e., deoxygenated) renewable linear hydrocarbons similar to those in a Diesel composition. However, DFT calculations indicate that adsorbed CO2 (as a formate species) desorbs, once fully hydrogenated, as methane regenerating the oxygen vacancies but consuming H2 as well, in agreement with the high methane concentration detected in gas phase.

Effectiveness of Salvadora persica toothbrush and Salvadora persica chewing stick in plaque and gingivitis control: a randomized control trial

BackgroundThe values of plant-based products have taken on an expanding relevance in dentistry. Salvadora persica chewing stick (miswak) has been practiced for centuries and is recommended by the World Health Organization as a customary oral hygiene tool. The therapeutic effects of S. persica chewing stick are contributed by its mechanical cleansing action, active chemicals released, or the combination of these two actions. However, the S. persica chewing stick in its natural form can be difficult to maneuver in certain parts of the mouth. This concern has inspired the innovation of the S. persica toothbrush that is designed to merge the ease of use of a toothbrush with the beneficial natural properties of S. persica preserved in its bristle. The present study aimed to compare the clinical effectiveness between S. persica toothbrush, S. persica chewing stick and the standard toothbrush in plaque and gingivitis control.MethodsIn this single-blinded and parallel randomized controlled trial, 78 participants were randomly divided into three groups to either use (i) S. persica toothbrush (MTB); (ii) S. persica chewing stick (MCS); or (iii) standard toothbrush (STB) in a standardized manner for three weeks. Plaque Index (PI) and Periodontal Inflamed Surface Area (PISA) values, measuring plaque levels and severity of gingivitis, respectively, were evaluated at baseline, one- and three-week post-interventions.ResultsThe MCS group showed a significant improvement in the mean PISA values of the anterior teeth compared to the MTB and STB groups (MCS: from 16.35 ± 10.03 to 3.41 ± 1.14; MTB: from 25.20 ± 14.01 to 3.57 ± 1.19; STB: from 26.54 ± 8.64 to 6.17 ± 0.86; p < .050). All three groups reported significant improvements (p < .001) in the plaque levels and the severity of gingivitis from baseline to three weeks after the intervention.ConclusionsFollowing correct techniques, S. persica toothbrush and chewing sticks are as effective as the standard toothbrush in plaque control and gingival health, which represent the reputed anti-plaque and anti-gingivitis properties of S. persica.Trial registrationThis clinical trial was prospectively registered in ClinicalTrials.gov with registration NCT04650685 (25/11/2020).

Discovery of potential RSK1 inhibitors for cancer therapy using virtual screening, molecular docking, molecular dynamics simulation, and MM/GBSA calculations

The p90 ribosomal protein S6 Kinase (RSK) family belongs to Ser/Thr protein kinases that includes four isoform RSK1-4 in mammals. The ribosomal protein S6 Kinase 1 (RSK1) is also known as ribosomal protein S6 kinase alpha-1 (RPS6KA1) is a special protein due to their two catalytic regions that is associated with abundantly various cancers and it is proposed as a drug target. Several RSK1 isoform inhibitors have been reported but none of them are used in clinical studies. Thus, we aimed to perform ligand pharmacophore mapping with the known inhibitor and structure-based virtual screening studies to determine potential candidates against RSK1-terminal kinase domains CTKD and NTKD. The studied compounds from the databases (ApexBio, ChEMBL, ChemDiv). The molecular docking study was performed with the resulted candidates by using CDOCKER and Glide/SP methods. The four candidates with the highest docking scores were used for further 100-ns molecular dynamics (MD) simulations and Molecular Mechanics Generalised Born and Surface Area (MM/GBSA) calculations. The root mean square deviation (RMSD) for protein complexes were found between 2 Å and 4 Å. Solvent accessible surface area (SASA), radius of gyration (Rg), and polar surface area (PSA) values were calculated for compounds. The binding free energies were calculated between −72.22 kcal/mol and −82.44 kcal/mol. The interaction diagrams showed that hydrogen bond, alkyl, and π-alkyl interactions were observed with specific residues such as Leu144, Lys94, Asp142 for RSK1-NTKD, and Cys532, Cys556, Lys447, Asn540 for RSK1-CTKD. The identified compounds may be potential inhibitor candidates of RSK1 following the preclinical studies. Communicated by Ramaswamy H. Sarma

Effect of Amino-Functionalized Polyhedral Oligomeric Silsesquioxanes on Structure-Property Relationships of Thermostable Hybrid Cyanate Ester Resin Based Nanocomposites.

Nanocomposites of cyanate ester resin (CER) filled with three different reactive amino-functionalized polyhedral oligomeric silsesquioxane (POSS) were synthesized and characterized. The addition of a small quantity (0.1 wt.%) of amino-POSS chemically grafted to the CER network led to the increasing thermal stability of the CER matrix by 12-15 °C, depending on the type of amino-POSS. A significant increase of the glass transition temperature, Tg (DSC data), and the temperature of α relaxation, Tα (DMTA data), by 45-55 °C of the CER matrix with loading of nanofillers was evidenced. CER/POSS films exhibited a higher storage modulus than that of neat CER in the temperature range investigated. It was evidenced that CER/aminopropylisobutyl (APIB)-POSS, CER/N-phenylaminopropyl (NPAP)-POSS, and CER/aminoethyl aminopropylisobutyl (AEAPIB)-POSS nanocomposites induced a more homogenous α relaxation phenomenon with higher Tα values and an enhanced nanocomposite elastic behavior. The value of the storage modulus, E', at 25 °C increased from 2.72 GPa for the pure CER matrix to 2.99-3.24 GPa for the nanocomposites with amino-functionalized POSS nanoparticles. Furthermore, CER/amino-POSS nanocomposites possessed a higher specific surface area, gas permeability (CO2, He), and diffusion coefficients (CO2) values than those for neat CER, due to an increasing free volume of the nanocomposites studied that is very important for their gas transport properties. Permeability grew by about 2 (He) and 3.5-4 times (CO2), respectively, and the diffusion coefficient of CO2 increased approximately twice for CER/amino-POSS nanocomposites in comparison with the neat CER network. The efficiency of amino-functionalized POSS in improving the thermal and transport properties of the CER/amino-POSS nanocomposites increased in a raw of reactive POSS containing one primary (APIB-POSS) < eight secondary (NPAP-POSS) < one secondary and one primary (AEAPIB-POSS) amino groups. APIB-POSS had the least strongly pronounced effect, since it could form covalent bonds with the CER network only by a reaction of one -NH2 group, while AEAPIB-POSS displayed the most highly marked effect, since it could easily be incorporated into the CER network via a reaction of -NH2 and -NH- groups with -O-C≡N groups from CER.

Surface area values for the human stomach including changes in length and diameter or width with meal volume

To quantify the amount of solid, liquid or gas that can be adsorbed on to a surface, the surface area must be known. Equations were developed to calculate the macroscopic surface area of the adult human stomach in vivo, at any given meal volume. For a meal volume of V≈0-2000 cm3, the surface area SA≈113-1030 cm2 and by using a cylinder-shaped stomach model, the diameter D≈2.4-10.3 cm, length L≈27-32 cm and width W≈ 7.5-32 cm. The cylinder model found for a given volume, the standard deviation in average surface area values may result from fluctuations in both length, diameter and width, indicating the stomach, by changing shape, changes surface area.

Enhanced dispersing properties of kaolin due to high-strength kneading process

In this study, the influence of high-strength kneading process on the dispersibility of kaolin was investigated. Various factors including crystallinity, shape and interaction energy of kaolin particles were investigated systematically based on XRD, SEM, FTIR, Zeta potential and DLVO analyses. The results showed that the high-strength kneading treatments increased the proportion of kaolinite (001) planes, reducing the friction between kaolin particles but increasing their crystallinity. In addition, this treatment promoted the tendency of kaolin to a pseudo-hexagonal shape. DLVO analyses further showed that the electrostatic repulsion energy between kaolin particles was proportional to the kneading time due to the increased specific surface area (e.g., increased from 14.63 to 18.24 m2·g−1) and negative charge value (e.g., decreased from −15 to −32 mV) of kaolin sample. This correspondingly led to a lower viscosity of kaolin pulp with better dispersing properties, e.g., the viscosity of kaolin samples decreased by 65.41% when kneading time was extended from 0 to 6 h. This study therefore provides a new strategy to reutilize kaolin sources with low dispersing properties and crystallinity after a high-strength kneading process.

Role of carbonization parameters on surface and microstructural and crystalline properties of mesoporous coconut shell char: Quantitative and structural study

The present work focuses on the synthesis of inactive mesoporous char using the carbonization method. The experiment was conducted at various conditions using a constant flow of nitrogen gas with variable temperature ramp and carbonization temperature i.e., 5 °C /min to 20 °C /min and 400 °C to 800 °C respectively. The product was identified by calculating its surface area, pore size, micro strain, interplanar spacing, packing density, full-width half maximum, crystallite size, lateral size, no of layers, dislocation density, crystallinity index, and morphological characterization. It was revealed that the best results in terms of surface area, pore size, micropore volume, and burn-off value of the char were observed at a carbonization temperature of 700 °C with a heating rate of 10 °C/min. The calculated values of surface area, pore size, micropore volume, and burn-off were found to be 211.816 m2/g, 2.288 nm, 0.121 cm3/g, and 20.2 % respectively.