Computational Chemistry and Molecular Modeling Techniques for the Study of Micropeptin EI-964: Insights into Its Chemical Reactivity and Potential Pharmaceutical Properties

Micropeptin EI-964 is a cyclic peptide compound isolated from a marine cyanobacterium with potent inhibitory activity against serine proteases, particularly chymotrypsin and trypsin. It has shown promising activity against various cancer cell lines, making it a candidate for drug development. The unique structure and activity of Micropeptin EI-964 make it a promising lead compound for the development of novel serine protease inhibitors and anti-cancer drugs. Computational Chemistry and Molecular Modeling techniques can provide valuable insights into the chemical reactivity and pharmaceutical properties of Micropeptin EI-964, guiding the design and development of new compounds with enhanced bioactivity and improved drug-like properties.

Solar hydrogen production from electrochemical ammonia splitting powered by a single perovskite solar cell

For carbon-free electrochemical fuel formation,the electrochemical cell must be powered by renewable energy.Obtaining solar-powered H_(2) fuel from water typically requires multiple photovoltaic cells and/or junctions to drive the water splitting reaction.Because of the lower thermodynamic requirements to oxidize ammonia compared to water,solar cells with smaller open circuit voltages can provide the required potential for ammonia splitting.In this work,a single perovskite solar cell with an open-circuit potential of 1.08 V is coupled to a 2-electrode electrochemical cell employing hybrid electroanodes functionalized with Ru-based molecular catalysts.The device is active for more than 30 min,producing N_(2) and H_(2) in a 1:2.9 ratio with 89%faradaic efficiency with no external applied bias.This work illustrates that hydrogen production from ammonia can be driven by conventional semiconductors.

Chemical Reactivity Properties, Drug-Likeness Features and Bioactivity Scores of the Cholecystokinin Peptide Hormone

Five density functionals, CAM-B3LYP, LC-ωPBE, MN12SX, N12SX and ωB97XD, in connection with the Def2TZVP basis set were assessed together with the SMD solvation model for the calculation of the molecular and chemical reactivity properties of the Cholecystokinin peptide hormone (CCK-8) in the presence of water. All the chemical reactivity descriptors for the systems were calculated via Conceptual Density Functional Theory (CDFT). The potential bioavailability and druggability as well as the bioactivity scoresfor CCK-8 were predicted through different methodologies already reported in the literature which have been previously validated during the study of different peptidic systems. The conclusion was that the CCK-8 peptide will be moderately bioactive regarding all the interactions.

Conceptual Density Functional Theory Study of the Chemical Reactivity Properties and Bioactivity Scores of the Leu-Enkephalin Opioid Peptide Neurotransmitter

The SMD solvation model (Solvation Model based on the Density) and eight density functionals, CAM-B3LYP, LC-ωPBE, M11, MN12SX, N12SX, ωB97, ωB97X, and ωB97XD, were assessed in link with the Def2TZVP basis set for the calculation of the structure of the Leu-Enkephalin Opioid Peptide Neurotransmitter as well as their molecular properties. Through the Conceptual Density Functional Theory (CDFT), the entire chemical descriptors for the system were calculated. The active regions of the molecules necessary for electrophilic, nucleophilic and radical attacks were chosen through linking them with the corresponding Fukui functions. Furthermore, the prediction of the pKa value for the peptide is done with great accuracy as well as the ability of the studied molecule in acting as an efficient inhibitor of the formation of Advanced Glycation Endproducts (AGEs), which comprises of a useful knowledge for the development of drugs for preventing Alzheimer, Diabetes and Parkinson diseases. Lastly, the bioactivity scores for the studied peptides are predicted via various methodologies.

Chemical Reactivity Theory (CRT) Study of the Melanoidin M8: Local Conceptual Density Functional Theory Descriptors

This study evaluated a fixed long-range corrected range-separated hybrid (RSH) density functional associated with the Def2TZVP basis set alongside the Solvation Model based on Density (SMD) for the computation of the structure, molecular properties and chemical reactivity of the M8 intermediate melanoidin pigment. The preference of the active sites pertinent to radical, nucleophilic and electrophilic attacks is made through linking them with the electrophilic and nucleophilic Parr functions, Fukui function indices, and condensed Dual Descriptor. This study showed that the MN12SX density functional is the most suitable one for predicting the chemical reactivity of this system.

A stable anthraquinone-derivative cathode to develop sodium metal batteries: The role of ammoniates as electrolytes

Rechargeable sodium metal batteries constitute a cost-effective option for energy storage although sodium shows some drawbacks in terms of reactivity with organic solvents and dendritic growth.Here we demonstrate that an organic dye,indanthrone blue,behaves as an efficient cathode material for the development of secondary sodium metal batteries when combined with novel inorganic electrolytes.These electrolytes are ammonia solvates,known as liquid ammoniates,which can be formulated as NaI·3.3NH_(3) and NaBF_(4)·2.5NH_(3).They impart excellent stability to sodium metal,and they favor sodium non-dendritic growth linked to their exceedingly high sodium ion concentration.This advantage is complemented by a high specific conductivity.The battery described here can last hundreds of cycles at 10 C while keeping a Coulombic efficiency of 99%from the first cycle.Because of the high capacity of the cathode and the superior physicochemical properties of the electrolytes,the battery can reach a specific energy value as high as 210 W h kgIB^(-1),and a high specific power of 2.2 kW kgIB^(-1),even at below room temperature(4℃).Importantly,the battery is based on abundant and cost-effective materials,bearing promise for its application in large-scale energy storage.

Comparative Study of the Chemical Reactivity of Helical Peptide Models for Protein Glycation

Non-enzymatic glycation of proteins has been implicated as an important cause of the complications associated with diabetes and Alzheimer disease. It is well known that glycation involves the reactivity of, primarily, the ε-amino group of the lysines present in the protein. The immediate chemical environment of an amino group modulates the glycation reaction. In this work, several model helical peptides for protein glycation has been studied by resorting to QM:MM calculations through the ONIOM methodology. Some Conceptual DFT descriptors have been calculated that allowed the comparison of the chemical reactivity between the different model peptides in terms of the position of the Lys group and other spatially proximate amino acid residues.

Computational Study of the Chemical Reactivity and Bioactivity Rates of Marine Peptides Hemiasterlin and Its A and B Derivatives Used in the Cancer Treatment through Conceptual Density Functional Theory

This study involved the assessment of the MNI2SX/Def2TZVP/H2O model chemistry to enhance the understanding of the structural composition of the marine peptide Hemiasterlin and its derivatives A and B used in cancer treatment. The Conceptual Density Functional theory was used in the calculation of molecular properties of the system chemical descriptors during the study. Integration of the active molecular regions into their respective Fukui functions was used in the selection of electrophilic and nucleophilic attacks. Additionally, the proposed correlation between global hardness and the pKa was used as the basis of deriving accurate predictions for the pKa values while a homology technique was used in the prediction of bioactivity and bioavailability scores of the peptides under investigation.

Machine learning applications on lunar meteorite minerals:From classification to mechanical properties prediction

Amid the scarcity of lunar meteorites and the imperative to preserve their scientific value,nondestructive testing methods are essential.This translates into the application of microscale rock mechanics experiments and scanning electron microscopy for surface composition analysis.This study explores the application of Machine Learning algorithms in predicting the mineralogical and mechanical properties of DHOFAR 1084,JAH 838,and NWA 11444 lunar meteorites based solely on their atomic percentage compositions.Leveraging a prior-data fitted network model,we achieved near-perfect classification scores for meteorites,mineral groups,and individual minerals.The regressor models,notably the KNeighbor model,provided an outstanding estimate of the mechanical properties—previously measured by nanoindentation tests—such as hardness,reduced Young’s modulus,and elastic recovery.Further considerations on the nature and physical properties of the minerals forming these meteorites,including porosity,crystal orientation,or shock degree,are essential for refining predictions.Our findings underscore the potential of Machine Learning in enhancing mineral identification and mechanical property estimation in lunar exploration,which pave the way for new advancements and quick assessments in extraterrestrial mineral mining,processing,and research.

Protein glycation:a wolf in sweet sheep’s clothing behind neurodegeneration

At the beginning of the 16th century,Paracelsus coined the maxim:“the dose makes the poison”.This principle can be applied to all living organisms,including organs and cells.The brain and its glial and neuronal cells are no exception.Even small compounds that are essential for the life of brain cells can become truly toxic when overdosed.

Determination of drug,excipients and coating distribution in pharmaceutical tablets using NIR-CI

The growing interest of the pharmaceutical industry in Near Infrared-Chemical Imaging (NIR-CI) is a result of its high usefulness for quality control analyses of drugs throughout their production process (particularly of its non-destructive nature and expeditious data acquisition).In this work,the concentration and distribution of the major and minor components of pharmaceutical tablets are determined and the spatial distribution from the internal and external sides has been obtained.In addition,the same NIR-CI allowed the coating thickness and its surface distribution to be quantified.Images were processed to extract the target data and calibration models constructed using the Partial Least Squares (PLS) algorithms.The concentrations of Active Pharmaceutical Ingredient (API) and excipients obtained for uncoated cores were essentially identical to the nominal values of the pharmaceutical formulation.But the predictive ability of the calibration models applied to the coated tablets decreased as the coating thickness increased.

Microbial oxidation of refractory gold sulfide concentrate by a native consortium

A defined mesophilic consortium including an iron oxidizing bacterium and a sulfur oxidizing bacterium was constructed to evaluate its ability for bioleaching a flotation concentrate from Andacollo mine in Neuquén,Argentina.Experiments were performed in shake flasks with a pulp density of10%(w/v),using a basal salt medium containing ferrous iron at pH1.8.The leaching solutions were analyzed for pH,redox potential(using specifics electrodes),ferrous iron(by UV-Vis spectrophotometry)and metal concentrations(by atomic absorption spectroscopy).The results showed that the consortium was able to reduce the refractory behavior of the concentrate,allowing91.6%of gold recovery;at the same time,high dissolution of copper and zinc was reached.These dissolutions followed a shrinking core kinetic model.According to this model,the copper solubilization was controlled by diffusion through a product layer(mainly jarosite),while zinc dissolution did not show a defined control step.This designed consortium,composed of bacterial strains with specific physiological abilities,could be useful not only to optimize gold recovery but also to decrease the leachates metallic charge,which would be an environmental advantage.

掺硼金刚石阳极电氧化和电芬顿工艺处理真实水体中低含量药物的研究(英文)

本文报告了采用掺硼金刚石阳极(BDD)电氧化和电芬顿工艺处理真实水体中注入含有少量药物残留物的单组分和多组分溶液(即1 mg.L-1对乙酰氨基酚和(或)1 mg.L-1水杨酸,pH=3)的研究结果.以恒定电流密度方式在BDD/Pt电解池中进行电氧化,而在BDD/空气扩散电解池中进行电芬顿,从而在阴极电生H2O2.结果表明,由于乙酰氨基酚和水杨酸均与溶液中氯离子氧化所产生的活性氯物种发生反应,因此,电氧化处理真实水体中两种药物的降解要比超纯水中添加0.05 mol.L-1Na2SO4快.这种含氯氧化剂的反应活性甚至超过了阳极形成的有限的羟基活性基,提高电流密度大大加速了两种污染物的消除.在真实水体自然碱性pH下得到了类似的结果.当电氧化处理两种药物的混合物时,两种药物上面产生的氧化剂的竞争作用,导致药物的降解变慢,只有电芬顿处理真实水体时药物的降解才稍微加快,这是由于H2O2与Cl-的反应,生成了反应活性弱得多的含氯活性基,从而抑制了电生的H2O2和添加的Fe2+之间发生的芬顿反应所形成的同相羟基活性基的累积.对于添加了药物的真实水体,在较高的电流密度下电氧化可得到较好的天然有机物成分(NOM)矿化度,且添加0.05 mol.L-1Na2SO4效果会更好.虽然在药物溶液的电氧化中检测出微量的氧化副产物,如对苯醌、NO3-和NH4+离子,但在本研究条件下无法去除真实水体中所含有的氮基化合物.

The Janus face of N-terminal lysines in α-synuclein

Parkinson’s disease(PD)is the second most prevalent progressive neurodegenerative disorder after Alzheimer’s disease.PD usually starts with a tremor in the extremities(usually in the hands)and gradually evolves with other symptoms such as bradykinesia,muscle stiffness,impaired posture,loss of automatic movements or speech changes.These symptoms worsen as the condition progresses and eventually lead to death.

Using fireball networks to track more frequent reentries:Falcon 9 upperstage orbit determination from video recordings

On February 16,2021,an artificial object moving slowly over the Mediterranean was recorded by the Spanish Meteor Network(SPMN).Based on astrometric measurements,we identified this event as the reentry engine burn of a SpaceX Falcon 9 launch vehicle’s upper stage.To study this event in detail,we adapted the plane intersection method for near-straight meteoroid trajectories to analyze the slow and curved orbits associated with artificial objects.To corroborate our results,we approximated the orbital elements of the upper stage using four pieces of“debris”cataloged by the U.S.Government’s Combined Space Operations Center.Based on these calculations,we also estimated the possible deorbit hazard zone using the MSISE90 model atmosphere.We provide guidance regarding the interference that these artificial bolides may generate in fireball studies.Additionally,because artificial bolides will likely become more frequent in the future,we point out the new role that ground-based detection networks can play in the monitoring of potentially hazardous artificial objects in near-Earth space and in determining the strewn fields of artificial space debris.

面向高稳定的光纤和生物相容性细胞平台的柔性荧光金属有机框架

荧光金属有机框架(FMOF)是一种很有前途的光电和生物应用材料,然而,一些主要缺点限制了它们在这些领域的广泛应用.首先,FMOF晶体难以用来构建柔性的自支撑平台.此外,这些材料对外部刺激表现出较低的光学稳定性,并且用于合成它们的金属离子通常有毒.基于此,我们开发了一种同轴微流控纺丝方法,实现了一步大规模连续制备核-壳FMOF微纤维.获得的自支撑FMOF基超细纤维具有85.6 MPa的高抗拉强度,是MOF复合材料中的最高强度值.此外,还证明了用该微流控方法生成的交联水凝胶壳可以有效地提高位于微纤维核心的FMOF晶体的光学稳定性,对抗可能会损坏FMOF的化学物质(如金属离子、酸、碱)以及热.最重要的是,由于水凝胶外壳的生物相容性和微纤维核心的固有荧光,基于FMOF的超细纤维具有较高的细胞活力(约96.6%)和多种细胞外荧光成像能力.因此,本文报道的基于柔性FMOF微纤维为设计光学和生物医学应用的新概念和材料组件提供了一个先进的平台.

The Development of Materials for the Production of Hydrogen from Bio-ethanol

1 Results There is an increased interest in the hydrogen production from renewable sources. In this context, recently, numerous studies which use ethanol for hydrogen production have appeared. Ethanol is easily handled, non-toxic, and it can be obtained from biomass. The steam-reforming of bioethanol has been shown to beeffective for hydrogen production:C2H5OH + 3 H2O  6 H2 + 2 CO2. Six moles of hydrogen can be yielded for each mole of ethanol reacted. However, depending on the catalyst used, other und...

Switchable Rashba anisotropy in layered hybrid organic-inorganic perovskite by hybrid improper ferroelectricity

Hybrid organic–inorganic perovskites(HOIPs)are introducing exotic directions in the photovoltaic materials landscape.The coexistence of inversion symmetry breaking and spin–orbit interactions play a key role in their optoelectronic properties.We perform a detailed study on a recently synthesized ferroelectric layered HOIP,(AMP)PbI_(4)(AMP=4-aminomethyl-piperidinium).The calculated polarization and Rashba parameters are in excellent agreement with experimental values.