Mimicking lightning-induced electrochemistry on the early Earth.

To test the hypothesis that an abiotic Earth and its inert atmosphere could form chemically reactive carbon- and nitrogen-containing compounds, we designed a plasma electrochemical setup to mimic lightning-induced electrochemistry under steady-state conditions of the early Earth. Air-gap electrochemical reactions at air-water-ground interfaces lead to remarkable yields, with up to 40 moles of carbon dioxide being reduced into carbon monoxide and formic acid, and 3 moles of gaseous nitrogen being fixed into nitrate, nitrite, and ammonium ions, per mole of transmitted electrons. Interfaces enable reactants (e.

σ-Hole, lone-pair-hole, and π-hole site-based interactions in aerogen-comprising complexes: a comparative study.

Herein, the potential of ZO and ZF aerogen-comprising molecules (where Z = Ar, Kr, and Xe) to engage in σ-, lp-, and π-hole site-based interactions was comparatively studied using various computations. For the first time, a premier in-depth elucidation of the external electric field (EEF) influence on the strength of the σ-, lp-, and π-hole site-based interactions within the ZO/ZF⋯NH and ⋯NCH complexes was addressed using oriented EEF with disparate magnitude. Upon the energetic features, σ-hole site-based interactions were noticed with the most prominent preferability in comparison to lp- and π-hole analogs.

σ-Hole Site-Based Interactions within Hypervalent Pnicogen, Halogen, and Aerogen-Bearing Molecules with Lewis Bases: A Comparative Study.

σ-Hole site-based interactions in the trigonal bipyramidal geometrical structure of hypervalent pnicogen, halogen, and aerogen-bearing molecules with pyridine and NCH Lewis bases (LBs) were comparatively examined. In this respect, the ZF···, XFO···, and AeFO···LB complexes (where Z = As, Sb; X = Br, I; Ae = Kr, Xe; and LB = pyridine and NCH) were investigated. The electrostatic potential (EP) analysis affirmations outlined the occurrence of σ-holes on the systems under consideration with disparate magnitudes that increased according to the following order: AeFO < XFO < ZF.

Hole interactions of aerogen oxides with Lewis bases: an insight into σ-hole and lone-pair-hole interactions.

σ-Hole and lone-pair (lp)-hole interactions of aerogen oxides with Lewis bases (LB) were comparatively inspected in terms of quantum mechanics calculations. The ZO ⋯ LB complexes (where Z = Kr and Xe, = 1, 2, 3 and 4, and LB = NH and NCH) showed favourable negative interaction energies. The complexation features were explained in light of σ-hole and lp-hole interactions within optimum distances lower than the sum of the respective van der Waals radii.

Density functional theory study of the corrosion inhibition performance of 6-mercaptopurine and 6-thioguanine expired drugs toward the aluminium (111) surface.

The potentiality of the 6-mercaptopurine (MP) and 6-thioguanine (TG) expired drugs toward the corrosion inhibition of the aluminium (Al) (111) surface was widely investigated using a series of density functional theory (DFT) calculations. A competition between the anti-corrosive features of the studied drugs in the gas and aqueous phases was conducted on both neutral and protonated forms by means of quantum mechanical descriptors. The results of the electrostatic potential analysis demonstrated the prominent nucleophilic nature of the sulfur and nitrogen atoms over the structures of the examined drugs.

Sigma-Hole and Lone-Pair-Hole Site-Based Interactions of Seesaw Tetravalent Chalcogen-Bearing Molecules with Lewis Bases.

For the first time, sigma (σ)- and lone-pair (lp)-hole site-based interactions of SF and SeF molecules in seesaw geometry with NH and FH Lewis bases were herein comparatively investigated. The obtained findings from the electrostatic potential analysis outlined the emergence of sundry holes on the molecular entity of the SF and SeF molecules, dubbed the σ- and lp-holes. The energetic viewpoint announced splendid negative binding energy values for σ-hole site-based interactions succeeded by lp-hole analogues, which were found to be -9.

Elucidating the adsorption of 2-Mercaptopyridine drug on the aluminum phosphide (AlP) nanocage: A DFT study.

Adsorption amplitude of the aluminum phosphide (AlP) nanocage toward the 2-Mercaptopyridine (MCP) drug was herein monitored based on density functional theory (DFT) calculations. The adsorption process through MCP⋅⋅⋅AlP complex in various configurations was elucidated by means of adsorption () energies. According to the energetic affirmations, the AlP nanocage demonstrated potential versatility toward adsorbing the MCP drug within the investigated configurations and exhibited significant negative adsorption energies up to -27.

Preferability of Molnupiravir, an Anti-COVID-19 Drug, toward Purine Nucleosides: A Quantum Mechanical Study.

Structural aspects of molnupiravir complexed with the RNA of the SARS-CoV-2 virus have been recently resolved inside the RNA-dependent RNA polymerase (RdRp), demonstrating the interactions of molnupiravir with purine nucleosides. However, the preference of molnupiravir to interact with one purine nucleoside over another has not been clearly investigated. Herein, the complexation of molnupiravir in its active form with guanosine and adenosine was compared, using sundry density functional theory calculations.

In-Silico Mining of the Toxins Database (T3DB) towards Hunting Prospective Candidates as ABCB1 Inhibitors: Integrated Molecular Docking and Lipid Bilayer-Enhanced Molecular Dynamics Study.

Multidrug resistance (MDR) is one of the most problematic issues in chemotherapeutic carcinoma therapy. The ABCB1 transporter, a drug efflux pump overexpressed in cancer cells, has been thoroughly investigated for its association with MDR. Thus, discovering ABCB1 inhibitors can reverse the MDR in cancer cells.

Adsorption Features of Tetrahalomethanes (CX; X = F, Cl, and Br) on Borophene and Pristine Graphene Nanosheets: A Comparative DFT Study.

The potentiality of the borophene () and pristine graphene (GN) nanosheets to adsorb tetrahalomethanes (CX; X = F, Cl, and Br) were investigated using density functional theory (DFT) methods. To provide a thorough understanding of the adsorption process, tetrel (XC-X∙∙∙/GN)- and halogen (XC-X∙∙∙/GN)-oriented configurations were characterized at various adsorption sites. According to the energetic manifestations, the adsorption process of the CX∙∙∙/GN complexes within the tetrel-oriented configuration led to more desirable negative adsorption energy () values than that within the halogen-oriented analogs.

A green compliant hand-held selective electrode device for monitoring active pharmaceuticals and the kinetics of their degradation.

An in-line smartphone connected to a screen-printed selective electrode hand-held device was used to determine the concentration of distigmine bromide (DB) in its pure and dosage forms as well as its degradation kinetics by continuously measuring the change in the produced emf over time. The main objective, supported by the data presented, is to produce a highly reliable smartphone integrated selective sensor as a portable analyzer with potential high cloud connectivity combining a wide linear dynamic range, the fastest response time with the lowest limits of detection and quantitation while best integrating green analytical chemistry principles. The choice of ionophore used in this approach was guided by computation and the data obtained was compared with traditional analytical techniques.

On the Use of Graphene Nanosheets for Drug Delivery: A Case Study of Cisplatin and Some of Its Analogs.

Graphene (GN) nanosheets have been widely exploited in biomedical applications as potential nanocarriers for various drugs due to their distinct physical and chemical properties. In this regard, the adsorption behavior of cisplatin (PtCl) and some of its analogs on a GN nanosheet was investigated in perpendicular and parallel configurations by using density functional theory (DFT). According to the findings, the most significant negative adsorption energies () within the PtX⋯GN complexes (where X = Cl, Br, and I) were observed for the parallel configuration, with values up to -25.

Stability of nucleic acid bases in concentrated sulfuric acid: Implications for the habitability of Venus' clouds.

What constitutes a habitable planet is a frontier to be explored and requires pushing the boundaries of our terracentric viewpoint for what we deem to be a habitable environment. Despite Venus' 700 K surface temperature being too hot for any plausible solvent and most organic covalent chemistry, Venus' cloud-filled atmosphere layers at 48 to 60 km above the surface hold the main requirements for life: suitable temperatures for covalent bonds; an energy source (sunlight); and a liquid solvent. Yet, the Venus clouds are widely thought to be incapable of supporting life because the droplets are composed of concentrated liquid sulfuric acid-an aggressive solvent that is assumed to rapidly destroy most biochemicals of life on Earth.

Green ecofriendly electrochemical sensing platform for the sensitive determination of doxycycline.

The detection of pharmaceutical compounds in extremely low concentrations remains a challenge despite recent advancements in electrochemical sensing. In this study, a green hydrothermally synthesized nickel hydroxide-graphene hybrid material was used for the point-of-care determination of the antibiotic doxycycline (DOXY), which is a promising treatment for COVID-19 and other infections. The electrochemical sensor, based on a screen-printed electrode modified with the hybrid material, was able to detect DOXY in the range of 5.

Anti-Cancer Peptides: Status and Future Prospects.

The dramatic rise in cancer incidence, alongside treatment deficiencies, has elevated cancer to the second-leading cause of death globally. The increasing morbidity and mortality of this disease can be traced back to a number of causes, including treatment-related side effects, drug resistance, inadequate curative treatment and tumor relapse. Recently, anti-cancer bioactive peptides (ACPs) have emerged as a potential therapeutic choice within the pharmaceutical arsenal due to their high penetration, specificity and fewer side effects.

Microfabricated potentiometric sensor for personalized methacholine challenge tests during the COVID-19 pandemic.

The methacholine challenge test is considered to be the gold standard bronchoprovocation test used to diagnose asthma, and this test is always performed in pulmonary function labs or doctors' offices. Methacholine (MCH) acts by inducing airway tightening/bronchoconstriction, and more importantly, MCH is hydrolyzed by cholinesterase enzyme (ChE). Recently, the American Thoracic Society raised concerns about pulmonary function testing during the COVID-19 pandemic due to recently reported correlation between cholinesterase and COVID-19 pneumonia severity/mortality, and it was shown that cholinesterase levels are reduced in the acute phase of severe COVID-19 pneumonia.

Application of ICH Guidelines for Studying the Degradation Behavior of Rocuronium Bromide Coupled with Stability-Indicating RP-LC Method.

Non-depolarizing neuromuscular blocking agent Rocuronium bromide was quantified in drug substance and drug product using reversed-phase liquid chromatographic method. Forced degradation studies were conducted for Rocuronium bromide in drug substance under acidic (2MHCl), basic (2MNaOH), oxidative (3% H2O2), thermal (135°C) and photolytic (254 nm) stress conditions. An Agilent H12 C18 column was used for separation using diammonium hydrogen phosphate buffer (pH 8; 0.

Development and Characterization of Cellulose/Iron Acetate Nanofibers for Bone Tissue Engineering Applications.

In tissue engineering, design of biomaterial with a micro/nano structure is an essential step to mimic extracellular matrix (ECM) and to enhance biomineralization as well as cell biocompatibility. Composite polymeric nanofiber with iron particles/ions has an important role in biomineralization and collagen synthesis for bone tissue engineering. Herein, we report development of polymeric cellulose acetate (CA) nanofibers (17 wt.

Novel choline selective electrochemical membrane sensor with application in milk powders and infant formulas.

Choline (Ch), is a vitamin-like essential water-soluble organic micronutrient. The US-FDA requires that infant formula not made from cow's milk must be supplemented with Ch. Direct determination of Ch in milk powders and infant formulas is a challenging task due to the lack of a detectable chromophore, its existence in free and complexed forms as well as the presence of multi-analytes in these complex matrices.

A comparative study of two analytical techniques for the simultaneous determination of amprolium HCl and ethopabate from combined dosage form and in presence of their alkaline degradation.

Chemometric and separation-based techniques (HPLC) are the most applicable and versatile analytical techniques for the analysis of multicomponent mixtures, in the present contribution, a comparison was highlighted between the two analytical techniques of utmost importance as stability indicating assays: UV-spectrophotometry and HPLC-UV focusing on the greenness of each for the simultaneous determination of amprolium HCl (AMP) and ethopabate (ETHOP) in the presence of their alkaline degradation products. The first method was chemometric methods applied were PLS-1, GA-PLS and GA-ANN. To compare the prediction ability of the models, a 4-factor 5-level experimental design was used to establish a calibration set of 25 mixtures containing different ratios of the drugs and their degradation products.

Synchronous UPLC Resolution of Aceclofenac and Diacerin in Their Powdered Forms and Matrix Formulation: Stability Study.

Accurate, rapid and selective reversed phase ultra-performance liquid chromatography method with UV detection has been established and validated for the synchronous determination of aceclofenac (ACE) and diacerin (DIA) in the occurrence of diclofenac sodium and rhein, their main degradation products, respectively. Chromatographic separation was accomplished using Inertsil C-18 column (50 × 2.1 mm i.

Correction: Chemical fingerprinting and quantitative monitoring of the doping drugs bambuterol and terbutaline in human urine samples using ATR-FTIR coupled with a PLSR chemometric tool.

[This corrects the article DOI: 10.1039/C9RA10033D.].

Chemical fingerprinting and quantitative monitoring of the doping drugs bambuterol and terbutaline in human urine samples using ATR-FTIR coupled with a PLSR chemometric tool.

The use of performance-enhancing drugs is prohibited in sports competitions according to the World Anti-Doping Agency (WADA) regulations. Here, ATR-FTIR spectroscopy coupled with a partial least squares regression (PLSR) chemometric tool was used for the detection of the misuse of such substances. Bambuterol and its metabolite terbutaline have been included in the list of prohibited doping agents.

Smart Spectral Processing of Data for the estimation of Commonly Used Over-the-counter (OTC) Co-formulated drug; Pseudoephedrine hydrochloride and Ibuprofen.

Oral pharmaceutical preparation containing pseudoephedrine hydrochloride (PSE) and ibuprofen (IBU) is widely prescribed as over- the- counter (OTC) for treatment of common cold-sinus. Development of four precise and accurate spectrophotometric methods are established for the concurrent determination of (PSE) and (IBU)in this preparation exploiting zero and/or ratio spectra. Method I is a dual wavelength method (DW).