Chemical Studies Research Articles

Chemical, electrochemical, and quantum investigation into the use of an organophosphorus derivative to inhibit copper corrosion in acidic environments.

In order to protect the copper against corrosion, a novel corrosion inhibitor known as diphenyl ((2-aminoethyl) amino) (4-methoxyphenyl) methyl) phosphonate (DAMP) was developed. Acid solutions of HCl and H2SO4 were the aggressive solutions employed in this study. Analysis using the FT-IR, 1H-NMR, 31P-NMR, 13C-NMR and BET confirmed that the DAMP was successfully synthesized. The anti-corrosion capabilities of DAMP are evaluated using a combination of chemical, electrochemical and quantum studies. The DAMP has been found to be crucial in preventing the corrosion of copper in both HCl and H2SO4 acid. This was obviously implied by the observation that the corrosion rate of copper in acid solutions decreased when DAMP was added. It is significant to note that 180ppm produced the highest levels of inhibiting efficiency (96.6% for HCl and 95.2% for H2SO4). The tendency of DAMP to adsorb on the surface of copper through its hetero-atoms (O, N, and P) is the main factor for the anti-corrosion capabilities of DAMP. Results from SEM/EDX tests supported this. The actual adsorption takes place via various active centers, physical and chemical mechanisms that are coordinated with the estimated quantum parameters. Additionally, the adsorption of DAMP adheres to the Langmuir isotherm.

(Invited) Luminescent InP Quantum Dots: They're Not Just Like CdSe

There are significant similarities and differences in the spectroscopy and photophysics between CdSe-based and InP-based quantum dots. One of the more important differences is the presence of reversibly populated hole traps in InP/ZnSe quantum dots (QDs). These traps affect many aspects of the overall excited state dynamics. In this paper we elucidate the hole relaxation dynamics in high quality InP/ZnSe/ZnS QDs at room temperature and focus on the role of these traps. Specifically, we show that the presence of transiently populated traps results in extremely slow (tens of picoseconds to nanoseconds) hole cooling as evidenced by a significant fraction of the photoluminescence exhibiting a slow risetime following photoexcitation. Through a combination of chemical derivatization studies and density functional theory calculations, they are assigned to substitutional indium adjacent to a zinc vacancy, In3+/VZn 2-, in the ZnSe shell.

Multi-Cellular Engineered Living Systems to Assess Reproductive Toxicology

Toxicants and some drugs can negatively impact reproductive health. Many toxicants haven’t been tested due to lack of available models. The impact of many drugs taken during pregnancy to address maternal health may adversely affect fetal development with life-long effects and clinical trials do not examine toxicity effects on the maternal-fetal interface, requiring indirect assessment of safety and efficacy. Due to current gaps in reproductive toxicological knowledge and limitations of animal models, multi-cellular engineered living systems may provide solutions for modeling reproductive physiology and pathology for chemical and xenobiotic toxicity studies. Multi-cellular engineered living systems model of functional units of tissues such as microphysiological systems (MPS) and organoids. In this review, we highlight the key functions and structures of human reproductive organs and well-known representative toxicants afflicting these systems. We then discuss current approaches and specific studies where scientists have used MPS or organoids to recreate in vivo markers and cellular responses of the female and male reproductive system, as well as pregnancy-associated placenta formation and embryo development. We provide specific examples of organoids and organ-on-chip that have been used for toxicological purposes with varied success. Finally, we address current issues related to usage of MPS, emerging techniques for improving upon these complications, and improvements needed to make MPS more capable in assessing reproductive toxicology. Overall, multi-cellular engineered living systems have considerable promise to serve as a suitable, alternative reproductive biological model compared to animal studies and 2D culture.

Structural and chemical study of complex silver patterns additively manufactured by multi-photon reduction.

Multi-photon reduction (MPR) based on femtosecond laser makes rapid prototyping and molding in micro-nano scale feasible, but is limited in material selectivity due to lack of the understanding of the reaction mechanism in MPR process. In this paper, additively manufacturing of complex silver-based patterns through MPR is demonstrated. The effects of laser parameters, including laser pulse energies and scanning speeds, on the structural and chemical characteristics of the printed structures are systematically investigated. The results show that the geometric size of printed cubes deviates from the designed size further by increasing laser pulse energies or decreasing scanning speeds. The reaction mechanism of MPR is revealed by studying the elemental composition and chemical structures of printed cubes. The evolution of Raman spectra upon the laser processing parameters suggests that the MPR process mainly includes two processes: reduction and decomposition. In the MPR process, silver ions are reduced and grow into particles by accepting the electrons from ethonal molecules; meanwhile carboxyl groups in polyvinylpyrrolidone are decomposed and form amorphous carbon that is attached on the surface of silver particles. The conductivity of silver wires fabricated by MPR reaches 2×105 S/m and stays relatively constant as varying their cross section area, suggesting excellent electrical conduction. The understanding of the MPR process would accelerate the development of MPR technology and the implementation of MPR in micro-electromechanical systems could therefore be envisioned.

Undescribed Cyclohexene and Benzofuran Alkenyl Derivatives from Choerospondias axillaris, a Potential Hypoglycemic Fruit

The fruit of Choerospondias axillaris (Anacardiaceae), known as south wild jujube in China, has been consumed widely in several regions of the world to produce fruit pastille and leathers, juice, jam, and candy. A comprehensive chemical study on the fresh fruits led to the isolation and identification of 18 compounds, including 7 new (1–7) and 11 known (8–18) comprised of 5 alkenyl (cyclohexenols and cyclohexenones) derivatives (1–5), 3 benzofuran derivatives (6–8), 6 flavonoids (9–14) and 4 lignans (15–18). Their structures were elucidated by extensive spectroscopic analysis. The known lignans 15–18 were isolated from the genus Choerospondias for the first time. Most of the isolates exhibited significant inhibitory activity on α-glucosidase with IC50 values from 2.26 ± 0.06 to 43.9 ± 0.96 μM. Molecular docking experiments strongly supported the potent α-glucosidase inhibitory activity. The results indicated that C. axillaris fruits could be an excellent source of functional foods that acquire potential hypoglycemic bioactive components.

The influence of topography and transport history on the composition of clastic deposits from the Jurassic Tlaxiaco basin, southern Mexico: limitations on the use of mineral and chemical indices as proxies for paleoclimate

ABSTRACT The mineral and chemical composition of clastic deposits is commonly used as a proxy for reconstructing the climatic history of the Earth. A mineralogical and chemical study of clastic deposits from the Jurassic Tlaxiaco basin of southern Mexico illustrates that the entire sedimentary system in which detritus is generated, subaerially transported, and deposited exerts a major control on the composition of sedimentary rocks, placing some constraints on the use of mineral and chemical indices as paleoclimatic proxies. Since clastic deposits of the Tlaxiaco basin were formed under similar humid climatic conditions, but in sedimentary systems with different topography and transport histories, they represent a natural laboratory for testing the control that these parameters exert on the composition of clastic rocks. Our petrographic and chemical results show that, in sedimentary systems associated with low relief and in which detritus had the possibility of being temporarily stored in floodplains and meandering bars, parent rocks and the derivative detritus interacted with weathering fluids over a long time, producing clastic deposits with composition that is representative of the weathering conditions and climate of the region. On the other hand, in environments associated with steep and tectonically active relief, the rates of sediment transport and burial exceed the rate at which weathering can generate detritus, producing sedimentary deposits with composition that largely underestimates potential weathering and provide unreliable information on climate. Mineral and chemical indices should be considered as reliable paleoclimate proxies only when sedimentological data indicate that the sedimentary system allowed sediment interaction with weathering fluids over a long time.

Pathways for macrophage uptake of cell-free circular RNAs.

Circular RNAs (circRNAs) are stable RNAs present in cell-free RNA, which may comprise cellular debris and pathogen genomes. Here, we investigate the phenomenon and mechanism of cellular uptake and intracellular fate of exogenous circRNAs. Human myeloid cells and B cells selectively internalize extracellular circRNAs. Macrophage uptake of circRNA is rapid, energy dependent, and saturable. CircRNA uptake can lead to translation of encoded sequences and antigen presentation. The route of internalization influences immune activation after circRNA uptake, with distinct gene expression programs depending on the route of RNA delivery. Genome-scale CRISPR screens and chemical inhibitor studies nominate macrophage scavenger receptor MSR1, Toll-like receptors, and mTOR signaling as key regulators of receptor-mediated phagocytosis of circRNAs, a dominant pathway to internalize circRNAs in parallel to macropinocytosis. These results suggest that cell-free circRNA serves as an "eat me" signal and danger-associated molecular pattern, indicating orderly pathways of recognition and disposal.

A New Species and a New Record of Byssoid Arthoniaceae (Lichenized Ascomycota) from Southern China

This paper illustrates two species in the lichen-forming family Arthoniaceae from southern China, including a new species of Herpothallon, H. fibrosum L.L. Liu & Lu L. Zhang and a new record of Cryptothecia, C. striata G. Thor for China. Herpothallon fibrosum has fluffy, cylindrical pseudoisidia, like a bundle of fiber, and psoromic acid and confluentic acid are present. Furthermore, the new record of Cryptothecia striata has been identified by morphological, anatomical, chemical, and molecular studies. The systematic position of the two species was clarified by the molecular sequence data from the small subunit of the mitochondrial ribosomal DNA (mtSSU). Detailed taxonomic descriptions, chemical characters, comparisons, and discussion of the characteristics of similar species are provided for the two species; the relationship between Cryptothecia and Herpothallon is also discussed here.

РАЗРАБОТКА СОСТАВА И ТЕХНОЛОГИИ ГЛАЗНЫХ КАПЕЛЬ АНЕСТЕЗИРУЮЩЕГО ДЕЙСТВИЯ

In modern ophthalmological practice, the use of local anesthetics for surface anesthesia of the eyeball becomes an integral stage in preparing the patient for diagnostic studies, therapeutic manipulations, surgical and laser interventions. The share of regional pain management methods is steadily increasing. However, at the same time, the list of requirements that local anesthetics must meet is also growing. According to them, the drug that combines high anesthetic activity and minimal toxicity should be considered the best. The local anesthetic anilocaine hydrochloride, developed according to the author's method in PGFA, exhibits high surface anesthetic activity with relatively low toxicity, and also has anti-inflammatory and moderate antimicrobial activity, which distinguishes it very favorably from the local anesthetics used and is an alternative to the use of expensive imported drugs. The purpose of this study is to develop the composition and technology of anesthetic eye drops. Materials and methods. The pharmaceutical substance anilocaine hydrochloride was used as a pharmacologically active component. The determination of the hydrogen index was carried out by the potentiometric method in accordance with the requirements of the OFS "Ionometry". To study the stability of eye drops, characterized by the indicator "Related impurities", a high-pressure liquid chromatograph "ShimadzuLCProminence" (Japan) was used. Statistical processing of the results of chemical studies was carried out according to generally accepted methods using standard EXCEL computer programs. Results and discussion. As a result of the conducted research, the composition of anesthetic eye drops based on anilocaine hydrochloride has been substantiated and developed. A technology for manufacturing eye drops has been developed to ensure the sterility of the resulting form. Conclusion. Based on technological and microbiological studies, the composition and technology of locally anesthetic eye drops based on anilocaine hydrochloride for surface (drip) anesthesia of the eyeball has been developed.

Structure and Spectroscopic Insights for CH3PCO Isomers: A High-Level Quantum Chemical Study.

The exploration of phosphorus-bearing species stands as a prolific field in current astrochemical research, particularly within the context of prebiotic chemistry. Herein, we have employed high-level quantum chemistry methodologies to predict the structure and spectroscopic properties of isomers composed of a methyl group and three P, C, and O atoms. We have computed relative and dissociation energies, as well as rotational, rovibrational, and torsional parameters using the B2PLYPD3 functional and the explicitly correlated coupled cluster CCSD(T)-F12b method. Based upon our study, all the isomers exhibit a bent heavy atom skeleton with CH3PCO being the most stable structure, regardless of the level theory employed. Following in energy, we found four high-energy isomers, namely, CH3OCP, CH3CPO, CH3COP, and CH3OPC. The computed adiabatic dissociation energies support the stability of all [CH3, P, C, O] isomers against fragmentation into CH3 and [P, C, O]. Torsional barrier heights associated with the methyl internal rotation for each structure have been computed to evaluate the occurrence of possible A-E splittings in the rotational spectra. For the most stable isomer, CH3PCO, we found a V3 barrier of 82 cm-1, which is slightly larger than that obtained experimentally for the N-counterpart, CH3NCO, yet still very low. Therefore, the analysis of its rotational spectrum can be anticipated as a challenging task owing to the effect of the CH3 internal rotation. The complete set of spectroscopic constants and transition frequencies reported here for the most stable isomer, CH3PCO, is intended to facilitate eventual laboratory searches.

Organic Donor-Acceptor Thermally Activated Delayed Fluorescence Photocatalysts in the Photoinduced Dehalogenation of Aryl Halides.

We report a family of donor-acceptor thermally activated delayed fluorescent (TADF) compounds based on derivatives of DMAC-TRZ, that are strongly photoreducing. Both Eox and thus E*ox could be tuned via substitution of the DMAC donor with a Hammett series of p-substituted phenyl moieties while Ered remained effectively constant. These compounds were assessed in the photoinduced dehalogenation of aryl halides, and analogues bearing electron withdrawing groups were found to produce the highest yields. Substrates of up to Ered=-2.72 V could be dehalogenated at low PC loading (1 mol %) and under air, conditions much milder than previously reported for this reaction. Spectroscopic and chemical studies demonstrate that all PCs, including literature reference PCs, photodegrade, and that it is these photodegradation products that are responsible for the reactivity.

Organic Donor–Acceptor Thermally Activated Delayed Fluorescence Photocatalysts in the Photoinduced Dehalogenation of Aryl Halides

AbstractWe report a family of donor‐acceptor thermally activated delayed fluorescent (TADF) compounds based on derivatives of DMAC‐TRZ, that are strongly photoreducing. Both Eox and thus E*ox could be tuned via substitution of the DMAC donor with a Hammett series of p‐substituted phenyl moieties while Ered remained effectively constant. These compounds were assessed in the photoinduced dehalogenation of aryl halides, and analogues bearing electron withdrawing groups were found to produce the highest yields. Substrates of up to Ered=−2.72 V could be dehalogenated at low PC loading (1 mol %) and under air, conditions much milder than previously reported for this reaction. Spectroscopic and chemical studies demonstrate that all PCs, including literature reference PCs, photodegrade, and that it is these photodegradation products that are responsible for the reactivity.

Integrating geoelectrical and water chemistry studies to explore environmental challenges with an Indigenous community in northern Canada

Integrating geoelectrical and water chemistry studies to explore environmental challenges with an Indigenous community in northern Canada

Theoretical calculations and molecular modelling of isoindoline compounds as anticonvulsant agents

The lack of safe and effective antiepileptic drugs is a persistent issue that could be addressed through the repurposing or further development of commonly available drugs. Due to high accuracy, low effort, and high cost, it is best to begin the search for alternative treatments with a theoretical chemical study. Isoindoline derivatives, their ΔG, and their molecular docking were subjected to the molecular level theory. Having a ΔG of -4.9, compound A1 demonstrated a unique activity against protein 1OHV (4-aminobutyrate-aminotransferase; from pig), while the same compound demonstrated distinct activity against protein 3F8E (coumarins as suicide carbonic anhydrase inhibitors) with a ΔG of -4.533. Moreover, compound A3 exhibited a unique activity against protein 6KZP (calcium channel-ligand) with a ΔG of -7.597. The undertaken DFT analysis determined the highest occupied molecular orbital (HOMO), the least unoc¬cupied molecular orbital (LUMO), and the HOMO-LUMO gap values for the studied derivatives (compound A1: -0.202, -0.091, and -0.111 eV; compound A3: -0.228, -0.102, and -0.126 eV, respectively). The ionization potential, the soft¬ness, the hardness, and other chemical properties of these compounds were subsequently computed. Drug likeness predictions were employed in order to show that the compounds adhered to Lipinski’s rule. Our results indicate that the molecular mass, log P, as well as the hydrogen bonding donors and acceptors of the herein assessed isoindoline compounds fall within acceptable ranges.

Theoretical calculations and molecular design of novel dioxoisoindoline derivatives as anticonvulsant agents

Our study discusses the need for the development of alternative treatments for antiepileptic drugs. It proposes a theoretical chemical study using dioxoisoindoline derivatives and molecular docking in order to find potential alterna¬tive drugs. Three compounds (S1, S3, and S4) exhibited distinct activity against specific proteins related to epilepsy treatment. Our study also describes a DFT study that analysed the energy levels of the derivatives. Furthermore, we employed Lipinski’s rule and drug likeness predictions in order to assess the suitability of the derivatives as medicines. The results indicate that the molecular mass, log P, hydrogen bonding donors, and acceptors of the compounds fall within acceptable ranges. Overall, our study emphasizes the importance of finding new treatments for epilepsy, and presents a preliminary investigation into the potential of dioxoisoindoline derivatives.

Overcoming Language Barrier for Scientific Studies via Unsupervised Literature Learning: Case Study on Solar Cell Materials Prediction

Data‐driven materials and chemical studies have been predominantly confined to English‐language databases, posing significant challenges for researchers in non‐English‐speaking regions to access and comprehend literature and derive scientific insights. In this manuscript, we present a machine learning approach designed for information extraction and knowledge acquisition in the materials and chemical science realm from non‐English literature databases, requiring minimal human intervention. We assess the efficacy of our language model through a case study centered on the prediction of solar cell materials using Chinese‐language sources. Our unsupervised learning model effectively extracts crucial latent chemical and materials data from non‐English literature resources. Subsequently, the language model successfully identifies existing solar cell materials and forecasts potential candidates from this non‐English corpus. To further validate the suitability of the proposed solar cell material candidates, we conduct ab‐initio density functional theory calculations to evaluate their structural and optoelectronic properties. The results demonstrate the optimal characteristics of the proposed candidates for photovoltaic applications, validating both the efficacy of our language model and the predictability of our approach. This study represents a significant stride towards comprehensive data‐driven machine learning for materials and chemical predictions, transcending the limitations of English literature. Furthermore, it offers a promising solution to aid researchers in non‐English‐speaking regions in overcoming language barriers and accessing valuable scientific discoveries.This article is protected by copyright. All rights reserved.

An eco-friendly and facile method for oil-water separation using the bio-Zn oxide-based superhydrophobic membrane.

This manuscript presents a novel approach for developing an environmentally friendly and effective oil-water separation membrane. Achieving a superhydrophobic (SH) coating on textile fabric (TF) involved a two-step process. Initially, the surface roughness was enhanced by applying bio-zinc oxide (ZnO) nanoparticles obtained from Thymbra spicata L. Subsequently, the roughened surface was modified with stearic acid, a material known for its low surface energy. The bio-ZnO nanoparticles exhibit a circular morphology with an average size of 21 nm. The coating demonstrated remarkable mechanical stability, maintaining SH properties even after an abrasion length of 300 mm. Chemical stability studies revealed that the prepared membrane retained SH properties within a pH range of 5-11, which ensures robust performance. Absorption capacity measurements showcased different capacities for n-hexane (Hex), corn oil (C.O), and silicone oil (S.O), with consistent performance over 10 absorption-desorption cycles. High oil-water separation efficiencies were achieved for hexane, C.O, and S.O, emphasizing the coating's versatility. Flux rate measurements demonstrated that oil passed through the membrane efficiently, with the highest flux observed for Hex. The prepared SH membrane has superior mechanical and chemical stability and high separation efficiencies, which positions it as a promising candidate for diverse industrial applications.

Fluorescence in depth: integration of spectroscopy and imaging with Raman, IR, and CD for advanced research.

Fluorescence spectroscopy serves as a vital technique for studying the interaction between light and fluorescent 
molecules. It encompasses a range of methods, each presenting unique advantages and applications. This 
technique finds utility in various chemical studies. This review discusses Fluorescence spectroscopy, its branches 
such as Time-Resolved Fluorescence Spectroscopy (TRFS) and Fluorescence Lifetime Imaging Microscopy 
(FLIM), and their integration with other spectroscopic methods, including Raman, Infrared (IR), and Circular 
Dichroism (CD) spectroscopies. By delving into these methods, we aim to provide a comprehensive 
understanding of the capabilities and significance of fluorescence spectroscopy in scientific research, highlighting 
its diverse applications and the enhanced understanding it brings when combined with other spectroscopic 
methods. This review looks at each technique's unique features and applications. It discusses the prospects of their 
combined use in advancing scientific understanding and applications across various domains.

Rapid assessment of the main economic value indicators in lupine flour samples using infrared spectroscopy

Background. A calibration model has been developed for rapid assessment of economic value indicators (protein, oil, and quinolizidine alkaloid contents) in the seeds of narrowleaf lupine accessions from VIR using near-infrared spectroscopy, with the help of which it is possible to decide on the further use of the accessions.Materials and methods. Biochemical quality indicators (protein, oil, and quinolizidine alkaloid content) were studied in the seeds of narrowleaf lupine (Lupinus angustifolius L.) grown in 2019 in the northwest of Russia. Calibration models for measuring protein, oil and alkaloids in lupine seeds (62 accessions) were developed using a MATRIX-I IR analyzer (Bruker Optics, Germany). To construct calibration models, we used the values obtained by chemical analysis methods accepted at VIR. The oil content in lupine seeds was assessed by the defatted dry residue technique in Soxhlet extractors, protein by the Kjeldahl method, and quinolizidine alkaloids by gas chromatography coupled with mass spectrometry. All indicators were recalculated on the dry-weight basis.Results and conclusion. Statistical significance of the developed models was verified according to the results of measuring the content of protein, oil and alkaloids in the seeds of the test batch. The protein and oil content data obtained using a calibration curve did not differ significantly from the results of chemical studies, in contrast to alkaloid indicators. Consequently, the developed calibration model for the MATRIX-I IR analyzer can be used for rapid assessment of protein and oil content in narrowleaf lupine flour samples, thus accelerating the process of obtaining data on the main economic value indicators. The analysis does not require reagents and is safe.

ИЗУЧЕНИЕ МАКРО- И МИКРОЭЛЕМЕНТНОГО СОСТАВА РОТОВОЙ ЖИДКОСТИ ПРИ ПРОВЕДЕНИИ ПРОФЕССИОНАЛЬНОГО ОТБЕЛИВАНИЯ ЗУБОВ

Aesthetic dentistry is one of the up-to-date trends in dentistry. There are a lot of methods targeted at eliminating discoloration, including teeth whitening. The dentist’s task is to choose the optimal whitening system. Patients, especially those who work in hazardous industries, are also interested in getting a snowwhite smile. The authors have conducted a comparative assessment of the effectiveness of a chemical activation system with a 37% concentration of hydrogen peroxide (USA) with a chemical activation system with a 35% concentration of carbamide peroxide (Russia). Changes in the chemical composition of oral fluid were revealed after the professional whitening procedure. The subject of the study is the chemical composition of oral fluid. The goal is to study the chemical composition of oral fluid during teeth whitening procedures. Methodology. The studies were carried out on the basis of the Department of Therapeutic Dentistry of the Federal State Budgetary Educational Institution of Higher Education “Privolzhsky Research Medical University” of the Ministry of Health of Russia, Autonomous Non-Profit Organization “Center for Biotic Medicine” of Dr. A.V. Skalny, State budgetary institution of the Ryazan region “Dental Clinic No. 1” (Ryazan). The study involved 50 patients of both sexes from 23 to 45 years old, who were employees of an aircraft repair plant in Ryazan. Patients were divided into two groups. A chemical study of oral fluid was performed for 50 people before teeth whitening and for 15 people, in the control group, after teeth whitening. Results. Determined macro- and micro elements differed in quantitative content between the studied groups. Comparing the obtained data of the concentration of elements in saliva with the results of the work of other researchers, we can conclude that there is a scattering in the results according to the literature, possibly due to the different “microelement” status of the regions in which the sample donors live. Conclusions. The results of the study demonstrate that both whitening systems have a pronounced effect on the chemical composition of the oral fluid, while the system based on 37% hydrogen peroxide led to a greater degree of normalization of the level of chemical elements in the oral fluid.