Reaching Quantum Accuracy in Predicting Adsorption Properties for Ethane/Ethene in Zeolitic Imidazolate Framework-8 at Low Pressure Regime.

Nanoporous materials in the form of metal-organic frameworks such as zeolitic imidazolate framework-8 (ZIF-8) are promising membrane materials for the separation of hydrocarbon mixtures. To compute the adsorption isotherms in such adsorbents, grand canonical Monte Carlo simulations have proven to be very useful. The quality of these isotherms depends on the accuracy of adsorbate-adsorbent interactions, which are mostly described using force fields owing to their low computational cost. However, force field predictions of adsorption uptake often show discrepancies from experiments at low pressures, providing the need for methods that are more accurate. Hence, in this work, we propose and validate two novel methodologies for the ZIF-8/ethane and ethene systems; a benchmarking methodology to evaluate the performance of any given force field in describing adsorption in the low-pressure regime and a refinement procedure to rescale the parameters of a force field to better describe the host-guest interactions and provide for simulation isotherms with close agreement to experimental isotherms. Both methodologies were developed based on a reference Henry coefficient, computed with the PBE-MBD functional using the importance sampling technique. The force field rankings predicted by the benchmarking methodology involve the comparison of force field derived Henry coefficients with the reference Henry coefficients and ranking the force fields based on the disparities between these Henry coefficients. The ranking from this methodology matches the rankings made based on uptake disparities by comparing force field derived simulation isotherms to experimental isotherms in the low-pressure regime. The force field rescaling methodology was proven to refine even the worst performing force field in UFF/TraPPE. The uptake disparities of UFF/TraPPE improved from 197% and 194% to 11% and 21% for ethane and ethene, respectively. The proposed methodology is applicable to predict adsorption across nanoporous materials and allows for rescaled force fields to reach quantum accuracy without the need for experimental input.

Synthesis of novel organophosphorus compounds via reaction of substituted 2-oxoindoline-3-ylidene with acetylenic diesters and triphenylphosphine or triphenyl phosphite.

An efficient reaction between triphenylphosphine or triphenyl phosphite and 2-oxoindoline-3-ylidene derivatives in the presence of acetylenic esters leads to functionalized 2-oxoindoline-3-ylidene containing phosphorus ylieds or phosphonate esters. All compounds obtained in these reactions are stable and have good yields.

Membrane Surface Modification via In Situ Grafting of GO/Pt Nanoparticles for Nitrate Removal with Anti-Biofouling Properties.

Nanofiltration processes for the removal of emerging contaminants such as nitrate are a focus of attention of research works as an efficient technique for providing drinking water for people. Polysulfone (PSF) nanofiltration membranes containing graphene oxide (GO)/Pt (0, 0.25, 0.5, 0.75, 1 wt%) nanoparticles were generated with the phase inversion pathway. The as-synthesized samples were characterized by FTIR, SEM, AFM, and contact angle tests to study the effect of GO/Pt on hydrophilicity and antibacterial characteristics. The results conveyed that insertion of GO/Pt dramatically improved the biofouling resistance of the membranes. Permeation experiments indicated that PSF membrane embracing 0.75 wt% GO/Pt nanoparticles had the highest nitrate flux and rejection ability. The membrane's configuration was simulated using OPEN-MX simulating software indicating membranes maintaining 0.75 wt% of GO/Pt nanoparticles revealed the highest stability, which is well in accordance with experimental outcomes.

Adsorption, degradation, and mineralization of emerging pollutants (pharmaceuticals and agrochemicals) by nanostructures: a comprehensive review.

This review discusses a fresh pool of research findings reported on the multiple roles played by metal-based, magnetic, graphene-type, chitosan-derived, and sonicated nanoparticles in the treatment of pharmaceutical- and agrochemical-contaminated waters. Some main points from this review are as follows: (i) there is an extensive number of nanoparticles with diverse physicochemical and morphological properties which have been synthesized and then assessed in their respective roles in the degradation and mineralization of many pharmaceuticals and agrochemicals, (ii) the exceptional removal efficiencies of graphene-based nanomaterials for different pharmaceuticals and agrochemicals molecules support arguably well a high potential of these nanomaterials for futuristic applications in remediating water pollution issues, (iii) the need for specific surface modifications and functionalization of parent nanostructures and the design of economically feasible production methods of such tunable nanomaterials tend to hinder their widespread applicability at this stage, (iv) supplementary research is also required to comprehensively elucidate the life cycle ecotoxicity characteristics and behaviors of each type of engineered nanostructures seeded for remediation of pharmaceuticals and agrochemicals in real contaminated media, and last but not the least, (v) real wastewaters are extremely complex in composition due to the mix of inorganic and organic species in different concentrations, and the presence of such mixed species have different radical scavenging effects on the sonocatalytic degradation and mineralization of pharmaceuticals and agrochemicals. Moreover, the formulation of viable full-scale implementation strategies and reactor configurations which can use multifunctional nanostructures for the effective remediation of pharmaceuticals and agrochemicals remains a major area of further research.

Relationship of Frontal Sinus Size and Maturation of Cervical Vertebrae for Assessment of Skeletal Maturity.

OBJECTIVES: This study aimed to assess the relationship of frontal sinus height and width with the cervical vertebral maturation (CVM) for assessment of skeletal maturity. MATERIALS AND METHODS: This retrospective study evaluated lateral cephalograms of 132 patients between 8 to 21 years, including 66 males and 66 females. For each of the six stages of the CVM, 22 patients (11 males and 11 females) were evaluated. The Ertuk's method was used to measure the height and width of the frontal sinus. The sinus height to width ratio was calculated and considered as the sinus index. The CVM was evaluated on the same lateral cephalograms using the Baccetti's method. The correlation of frontal sinus height and width with the CVM was analyzed, and comparisons were made using independent t-test, ANOVA, Mann-Whitney test, and Kendall's tau-b correlation coefficient. RESULTS: The sinus width was 10.85±2.7 mm in males and 9.47±2.6 mm in females. The sinus index was 2.43±0.37 in males and 2.66±0.32 in females (P<0.000). The frontal sinus index and width were significantly greater in males but the sinus length was not significantly different between males and females (P=0.383). Significant differences were found in stages 2 and 3, and also 4 and 5 in females and 2 and 3, 3 and 4, and 4 and 5 in males. The mean frontal sinus index had a significant correlation with the CVM stage in both groups. CONCLUSION: According to the results, the frontal sinus index cannot be used as a predictor of skeletal maturity.

Comparison of interdental papilla around single implants in the anterior maxilla between two implant systems: A cohort study.

Background. In successful replacement of a tooth with a dental implant, soft tissue esthetic is as important as stability and function of the implant. Quality and quantity of the peri-implant mucosa can influence esthetic outcomes. This study assessed implant esthetic success of two different implant systems. In this regard the interdental papilla was evaluated and the relation-ship between implant type and crestal bone loss adjacent to implant was assessed. Methods. Eighteen patients (11 males, 7 females) with a total of 18 implants participated in this historical cohort study. Patients were divided into two groups based on the type of implants: Implantium group and SPI group; 36 interproximal papillae were evaluated photographically, using Jemt's papillary presence index (PPI). Radiographic analysis was carried out to find out the relation between bone loss and type of implant. Analysis of data was performed with SPSS 18, using Fisher's exact test, independent t-test, Spearman's correlation coefficient and ANOVA. Results. Comparison of photographs did not show a statistically significant difference in PPI between the two groups (P=0.94). Radiographic evaluation of crestal bone loss adjacent to implant shoulder did not reveal significant differences between the two groups (P=0.30). Conclusion. Implant therapy in the anterior maxilla, using Implantium or SPI system, did not result in significant differences in esthetics. In this study, there was an inverse relationship between the distance of contact point to bone crest and papilla index (P=0.002 in the SPI group) (P=0.02 in the Implantium group).

Excision of epulis granulomatosa with diode laser in 8 years old boy.

INTRODUCTION: Epulis granulomatosa is a lesion which grows from an extraction socket. It can be misdiagnosed with lesions of the same clinical appearance such as: foreign body or pyogenic granuloma, or as a herniation of the maxillary sinus. The most common treatment is surgical excision. CASE REPORT: The present article reports an Epulis granulomatosa which was removed with diode laser (810 nm) due to child's fear related to traditional surgical instruments and bleeding. RESULTS AND CONCLUSION: Lasers are useful for soft tissue surgery in modern dentistry, especially in relation to pediatric patients due to the rapid and regular wound healing without sutures.