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1.
Int J Pharm ; : 124498, 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39187424

RESUMEN

This work presents an indicator-based assessment of potential supply risks for pharmaceutical excipients. The assessment was conducted systematically through the steps of survey, data collection, and indicator value calculation. Japan was specified as the target, and all marketed products were analyzed. As the basis of the indicator, the Herfindahl-Hirschman index (HHI), a well-established method for measuring market concentration in economics, was adopted. Modifications were made to enable comparison of the risk levels of compounds, dosage forms, and diseases. Case studies were performed on each of these levels, and recommendations were obtained for risk mitigation. On the compound level, magnesium stearate, a commonly used lubricant, showed the highest risk, and a switch to alternative compounds was recommended. The dosage-form level evaluation showed that tablets and capsules could have higher risk levels than granules, indicating the importance of diversification. Finally, the disease-level evaluation showed that the supply of adult disease drugs might be risky because of the frequent use of tablets; less reliance on tablet forms was advised for adult diseases.

2.
Glycobiology ; 34(1)2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-37935401

RESUMEN

It is important to recognize the great diversity of monosaccharides commonly encountered in animals, plants, and microbes, as well as to organize them in a visually interesting style that also emphasizes their similarities and relatedness. This article discusses the nature of building blocks, monosaccharides, and monosaccharide derivatives-terms commonly used in discussing "glycomolecules" found in nature. To aid in awareness of monosaccharide diversity, here is presented a Periodic Table of Monosaccharides. The rationale is given for construction of the Table and the selection of 103 monosaccharides, which is largely based on those presented in the KEGG and SNFG websites of monosaccharides, and includes room to enlarge as new discoveries are made. The Table should have educational value and is intended to capture the attention and foster imagination of those not very familiar with glycosciences, and encourage researchers to delve deeper into this fascinating area.


Asunto(s)
Monosacáridos , Plantas , Animales
3.
Acta Pharm ; 73(4): 735-753, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38147476

RESUMEN

The chemical science community will commemorate the 155th anniversary of Mendeleev's groundbreaking discovery of the periodic table of elements in 2024. This paper aims to underscore the significance of Mendeleev's honorary membership in the Academy of Sciences in Zagreb, Croatia, which occurred in 1882, making it the first scientific academy in Europe to extend this recognition. Additionally, we seek to explore the contextual circumstances that contributed to this noteworthy event within the broader European context. To provide insight into the specificities and variations in the influence and reception of the periodic table of elements within the educational process of select European countries (Russia, Germany, Czech Lands, Serbia), we conducted a comprehensive review, drawing comparisons to Croatia. Notably, upon its initial publication in 1869, the discovery of the periodic table did not gain immediate acceptance in Croatia, largely attributed to the absence of a well-established presence of chemical science within the country. About fifteen years passed from Mendeleev's discovery of the periodic law to its reception and dissemination throughout Croatia. Despite an initial delay, Croatian chemical science followed the development of the periodic table through secondary and university education, while actively partaking it in.


Asunto(s)
Química , Croacia , Química/educación , Elementos Químicos , Europa Oriental
4.
Proc Natl Acad Sci U S A ; 120(43): e2303989120, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37856546

RESUMEN

The Periodic Law of Chemistry is one of the great discoveries in cultural history. Elements behaving chemically similar are empirically merged in groups G of a Periodic Table, each element with G valence electrons per neutral atom, and with upper limit G for the oxidation and valence numbers. Here, we report that among the usually mono- or di-valent s-block elements (G = 1 or 2), the heaviest members (87Fr, 88Ra, 119E, and 120E) with atomic numbers Z = 87, 88, 119, 120 form unusual 5- or 6-valent compounds at ambient conditions. Together with well-reported basic changes of valence at the end of the 6d-series, in the whole 7p-series, and for 5g6f-elements, it indicates that at the bottom of common Periodic Tables, the classic Periodic Law is not as straightforward as commonly expected. Specifically, we predict the feasible experimental synthesis of polyvalent [RaL-n] (n = 4, 6) compounds.

5.
Beilstein J Nanotechnol ; 14: 939-950, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37736658

RESUMEN

Nanoparticles with their unique features have attracted researchers over the past decades. Heavy metals, upon release and emission, may interact with different environmental components, which may lead to co-exposure to living organisms. Nanoscale titanium dioxide (nano-TiO2) can adsorb heavy metals. The current idea is that nanoparticles (NPs) may act as carriers and facilitate the entry of heavy metals into organisms. Thus, the present study reports nanoscale quantitative structure-activity relationship (nano-QSAR) models, which are based on an ensemble learning approach, for predicting the cytotoxicity of heavy metals adsorbed on nano-TiO2 to human renal cortex proximal tubule epithelial (HK-2) cells. The ensemble learning approach implements gradient boosting and bagging algorithms; that is, random forest, AdaBoost, Gradient Boost, and Extreme Gradient Boost were constructed and utilized to establish statistically significant relationships between the structural properties of NPs and the cause of cytotoxicity. To demonstrate the predictive ability of the developed nano-QSAR models, simple periodic table descriptors requiring low computational resources were utilized. The nano-QSAR models generated good R2 values (0.99-0.89), Q2 values (0.64-0.77), and Q2F1 values (0.99-0.71). Thus, the present work manifests that ML in conjunction with periodic table descriptors can be used to explore the features and predict unknown compounds with similar properties.

6.
Biosystems ; 232: 104990, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37611861

RESUMEN

The gene encoding the spike glycoprotein of the SARS-CoV-2 virus that causes COVID-19 disease, was analyzed through two types of periodic tables (standard and cube) of the genetic code to discover the internal fine structure of the spike (S) protein. The analysis was performed on the Wuhan-Hu-1 SARS-CoV-2 sequence (GenBank accession number NC_045512.2). A partition was detected between codon numbers (three-letter code numbers) 47 and 48 that code amino acids in the S-protein. The population distribution of organized codes and amino acid replacements in the S-protein showed large differences between two regions of the cube-type periodic table. The genetic codes of codon numbers 48-63 (4th plane of the cube table) had a higher frequency than the genetic codes of each of the other three planes (1st-3rd planes). Planes-linkage structures involved in the partition were also analyzed and a simplified model for the S-protein gene was obtained where a planes-linkage of the 4th plane and another planes-linkage of the 1st-3rd planes were linked together in alternate shifts. Most of the code population in the 4th plane and their planes-linkage multiformity gave additional support to the partition between codon numbers 47 and 48 in the S-protein gene. Analysis of real lineages of the SARS-CoV-2 virus through the cube-type periodic table identified distinguishing features of the Omicron lineage that included not only a large code population within the receptor-binding domain of the S-protein, but also large percentage rises in the population of amino acid replacements in the 1st and 2nd planes.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/genética , Glicoproteína de la Espiga del Coronavirus/genética , Aminoácidos , Glicoproteínas
7.
SAR QSAR Environ Res ; 34(6): 459-474, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37350771

RESUMEN

Metal oxide nanoparticles (MeOxNPs) can be made safer by understanding the interaction between the immune system and nanoparticles. A nano-quantitative structure-activity relationship (nano-QSAR) model can be used to evaluate nanoparticle risk quickly and conveniently. The present work attempts to develop nano-QSAR models to determine the inflammatory potential of MeOxNPs based on the THP-1 cell line. A comprehensive dataset comprising 32 MeOxNPs was used to develop a regression model with fold change (FC) of pro-inflammatory cytokine interleukin (IL)-1beta (IL-1b) release in the THP-1 cell line as the endpoint. Further, the same number of MeOx NPs with varying doses was modelled for the cell viability [-ln(p/(1-p))] endpoint. The results obtained from regression models were statistically significant. The descriptors obtained from the developed predictive models inferred that dose, electronegativity and the presence of metal ions and oxygen can be responsible for IL-1ß leakage from the THP-1 cell line. Based on our results, we can conclude that periodic table-based descriptors, incorporated into the QSAR models, are reliable for modelling pro-inflammatory potential. Researchers can use these comprehensive results to design metal oxide nanoparticles with lower toxicity and determine the cause of pro-inflammatory conditions induced by MeOxNPs.


Asunto(s)
Nanopartículas del Metal , Nanopartículas , Humanos , Óxidos/toxicidad , Relación Estructura-Actividad Cuantitativa , Nanopartículas del Metal/toxicidad , Nanopartículas/toxicidad , Metales/toxicidad , Células THP-1
8.
Adv Microb Physiol ; 82: 1-127, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36948652

RESUMEN

Living systems are built from a small subset of the atomic elements, including the bulk macronutrients (C,H,N,O,P,S) and ions (Mg,K,Na,Ca) together with a small but variable set of trace elements (micronutrients). Here, we provide a global survey of how chemical elements contribute to life. We define five classes of elements: those that are (i) essential for all life, (ii) essential for many organisms in all three domains of life, (iii) essential or beneficial for many organisms in at least one domain, (iv) beneficial to at least some species, and (v) of no known beneficial use. The ability of cells to sustain life when individual elements are absent or limiting relies on complex physiological and evolutionary mechanisms (elemental economy). This survey of elemental use across the tree of life is encapsulated in a web-based, interactive periodic table that summarizes the roles chemical elements in biology and highlights corresponding mechanisms of elemental economy.


Asunto(s)
Oligoelementos , Micronutrientes , Sodio , Nutrientes
9.
Acta Crystallogr E Crystallogr Commun ; 79(Pt 3): 124-128, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36909985

RESUMEN

There are about 100 chemical elements, and 200 space groups, rounding to the nearest hundreds. The elements, by virtue of the iconic periodic table, which hangs in schoolrooms worldwide, are part of our common culture. Few on the outside of solid-state science and discrete mathematics know of the remarkable enumeration of the space groups and how they organize solids, the chemical elements included, that can be conformed to translationally periodic lattices in three dimensions. Perhaps the comparative inaccessibility of space groups to non-specialists can be attributed to the absence of a single chart that captures and organizes the space groups in a glance, as does the periodic table for the chemical elements? Here is designed a periodic-like table of the space groups. The symmorphic space groups are organized as the coordinates of two non-linear, non-orthogonal axes that capture the point group symmetry and the order of the group, the multiplicity of general positions. The related non-symmorphic groups are treated as 'isotopes' of the symmorphic groups and are enumerated with a subscript. The intent is to inspire better designs and to bring the crystallographic space groups to the attention of a wider audience.

10.
SN Comput Sci ; 4(1): 13, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36267467

RESUMEN

Although few performance evaluation instruments have been used conventionally in different machine learning-based classification problem domains, there are numerous ones defined in the literature. This study reviews and describes performance instruments via formally defined novel concepts and clarifies the terminology. The study first highlights the issues in performance evaluation via a survey of 78 mobile-malware classification studies and reviews terminology. Based on three research questions, it proposes novel concepts to identify characteristics, similarities, and differences of instruments that are categorized into 'performance measures' and 'performance metrics' in the classification context for the first time. The concepts reflecting the intrinsic properties of instruments such as canonical form, geometry, duality, complementation, dependency, and leveling, aim to reveal similarities and differences of numerous instruments, such as redundancy and ground-truth versus prediction focuses. As an application of knowledge representation, we introduced a new exploratory table called PToPI (Periodic Table of Performance Instruments) for 29 measures and 28 metrics (69 instruments including variant and parametric ones). Visualizing proposed concepts, PToPI provides a new relational structure for the instruments including graphical, probabilistic, and entropic ones to see their properties and dependencies all in one place. Applications of the exploratory table in six examples from different domains in the literature have shown that PToPI aids overall instrument analysis and selection of the proper performance metrics according to the specific requirements of a classification problem. We expect that the proposed concepts and PToPI will help researchers comprehend and use the instruments and follow a systematic approach to classification performance evaluation and publication.

11.
Metallomics ; 14(8)2022 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-35820043

RESUMEN

This year marks the 20th anniversary of the field of metallomics. As a landmark in time, it is an occasion to reflect on the past, present, and future of this integrated field of biometal sciences. A fundamental bias is one reason for having metallomics as a scientific discipline. The focus of biochemistry on the six non-metal chemical elements, collectively known with the acronym SPONCH (sulphur, phosphorus, oxygen, nitrogen, carbon, hydrogen), glosses over the fact that the lower quantities of many other elements have qualities that made them instrumental in the evolution of life and pivotal in numerous life processes. The metallome, alongside the genome, proteome, lipidome, and glycome, should be regarded as a fifth pillar of elemental-vis-à-vis molecular-building blocks in biochemistry. Metallomics as 'global approaches to metals in the biosciences' considers the biological significance of most chemical elements in the periodic table, not only the ones essential for life, but also the non-essential ones that are present in living matter-some at higher concentrations than the essential ones. The non-essential elements are bioactive with either positive or negative effects. Integrating the significance of many more chemical elements into the life sciences requires a transformation in learning and teaching with a focus on elemental biology in addition to molecular biology. It should include the dynamic interactions between the biosphere and the geosphere and how the human footprint is changing the ecology globally and exposing us to many additional chemical elements that become new bioelements.


Asunto(s)
Disciplinas de las Ciencias Biológicas , Metales , Carbono , Humanos , Metales/química , Nitrógeno , Fósforo
12.
Proc Natl Acad Sci U S A ; 119(30): e2119083119, 2022 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-35867818

RESUMEN

The periodic system, which intertwines order and similarity among chemical elements, arose from knowledge about substances constituting the chemical space. Little is known, however, about how the expansion of the space contributed to the emergence of the system-formulated in the 1860s. Here, we show by analyzing the space between 1800 and 1869 that after an unstable period culminating around 1826, chemical space led the system to converge to a backbone structure clearly recognizable in the 1840s. Hence, the system was already encoded in the space for about two and half decades before its formulation. Chemical events in 1826 and in the 1840s were driven by the discovery of new forms of combination standing the test of time. Emphasis of the space upon organic chemicals after 1830 prompted the recognition of relationships among elements participating in the organic turn and obscured some of the relationships among transition metals. To account for the role of nineteenth century atomic weights upon the system, we introduced an algorithm to adjust the space according to different sets of weights, which allowed for estimating the resulting periodic systems of chemists using one or the other weights. By analyzing these systems, from Dalton up to Mendeleev, Gmelin's atomic weights of 1843 produce systems remarkably similar to that of 1869, a similarity that was reinforced by the atomic weights on the years to come. Although our approach is computational rather than historical, we hope it can complement other tools of the history of chemistry.

13.
Proc Natl Acad Sci U S A ; 119(10): e2117416119, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-35238642

RESUMEN

SignificanceOver the years, many unusual chemical phenomena have been discovered at high pressures, yet our understanding of them is still very fragmentary. Our paper addresses this from the fundamental level by exploring the key chemical properties of atoms-electronegativity and chemical hardness-as a function of pressure. We have made an appropriate modification to the definition of Mulliken electronegativity to extend its applicability to high pressures. The change in atomic properties, which we observe, allows us to provide a unified framework explaining (and predicting) many chemical phenomena and the altered behavior of many elements under pressure.

14.
Biosystems ; 214: 104636, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35181371

RESUMEN

The Canonical Table of the Genetic Code (CTGC) is constructed theoretically on the basis of the similarity of PFs (PF) of proteins with the conformation of 4-arc chain graphs (Karasev, 2019). Of the 64 conformations of the graph, specified by the position of the connectivity edges, and the matrices of 6 variables (x1 … x6), xi = (0, 1), 4 blocks of 16 elements each were formed. Then they were coded in the form of triplets based on the correspondence of pairs of variables to four letters of the code: 00 = C, 01 = U, 10 = G, 11 = A, and supplemented based on the known triplet-amino acid assignment. The resulting table is compared with the Periodic Table of Chemical Elements (PTCE). As in the PTCE, this CTGC has an initial element - a triplet that encodes graphs with zero number of connected edges. Within each block, vacancies are filled with connectivity edges in two alternative ways, both in rows and in the columns. As we move from the initial block 00 to the final block 11, there is a sequential filling of vacancies for variables x3x4: 00, 01, 10, 11. In general, the CTGC can be considered as a periodic system of triplets. Comparison with the previously described variety of tables of the genetic code made it possible to conclude that the CTGC more adequately reflects the properties of the genetic code. Prospects for the possible application of this table are being discussed.


Asunto(s)
Aminoácidos , Código Genético , Aminoácidos/genética , Código Genético/genética , Proteínas/genética
15.
Chemphyschem ; 23(6): e202100880, 2022 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-35212126

RESUMEN

In the periodic table the position of each atom follows the 'aufbau' principle of the individual electron shells. The resulting intrinsic periodicity of atomic properties determines the overall behavior of atoms in two-dimensional (2D) bonding and structure formation. Insight into the type and strength of bonding is the key in the discovery of innovative 2D materials. The primary features of 2D bonding and the ensuing monolayer structures of the main-group II-VI elements result from the number of valence electrons and the change of atom size, which determine the type of hybridization. The results reveal the tight connection between strength of bonding and bond length in 2D networks. The predictive power of the periodic table reveals general rules of bonding, the bonding-structure relationship, and allows an assessment of published data of 2D materials.

16.
Chem Teach Int ; 3(1): 57-65, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34268481

RESUMEN

PubChem (https://pubchem.ncbi.nlm.nih.gov) is one of the top five most visited chemistry web sites in the world, with more than five million unique users per month (as of March 2020). Many of these users are educators, undergraduate students, and graduate students at academic institutions. Therefore, PubChem has a great potential as an online resource for chemical education. This paper describes the PubChem Periodic Table and Element pages, which were recently introduced to celebrate the 150th anniversary of the periodic table. These services help users navigate the abundant chemical element data available within PubChem, while providing a convenient entry point to explore additional chemical content, such as biological activities and health and safety data available in PubChem Compound pages for specific elements and their isotopes. The PubChem Periodic Table and Element pages are also available as widgets, which enable web developers to display PubChem's element data on web pages they design. The elemental data can be downloaded in common file formats and imported into data analysis programs (e.g., spreadsheet software, like Microsoft Excel and Google Sheets, and computer scripts, such as python and R). Overall, the PubChem Periodic Table and Element pages improve access to chemical element data from authoritative sources.

17.
BMC Ecol Evol ; 21(1): 149, 2021 07 30.
Artículo en Inglés | MEDLINE | ID: mdl-34330210

RESUMEN

BACKGROUND: Environmental conditions on Earth are repeated in non-random patterns that often coincide with species from different regions and time periods having consistent combinations of morphological, physiological and behavioral traits. Observation of repeated trait combinations among species confronting similar environmental conditions suggest that adaptive trait combinations are constrained by functional tradeoffs within or across niche dimensions. In an earlier study, we assembled a high-resolution database of functional traits for 134 lizard species to explore ecological diversification in relation to five fundamental niche dimensions. Here we expand and further examine multivariate relationships in that dataset to assess the relative influence of niche dimensions on the distribution of species in 6-dimensional niche space and how these may deviate from distributions generated from null models. We then analyzed a dataset with lower functional-trait resolution for 1023 lizard species that was compiled from our dataset and a published database, representing most of the extant families and environmental conditions occupied by lizards globally. Ordinations from multivariate analysis were compared with null models to assess how ecological and historical factors have resulted in the conservation, divergence or convergence of lizard niches. RESULTS: Lizard species clustered within a functional niche volume influenced mostly by functional traits associated with diet, activity, and habitat/substrate. Consistent patterns of trait combinations within and among niche dimensions yielded 24 functional groups that occupied a total niche space significantly smaller than plausible spaces projected by null models. Null model tests indicated that several functional groups are strongly constrained by phylogeny, such as nocturnality in the Gekkota and the secondarily acquired sit-and-wait foraging strategy in Iguania. Most of the widely distributed and species-rich families contained multiple functional groups thereby contributing to high incidence of niche convergence. CONCLUSIONS: Comparison of empirical patterns with those generated by null models suggests that ecological filters promote limited sets of trait combinations, especially where similar conditions occur, reflecting both niche convergence and conservatism. Widespread patterns of niche convergence following ancestral niche diversification support the idea that lizard niches are defined by trait-function relationships and interactions with environment that are, to some degree, predictable and independent of phylogeny.


Asunto(s)
Lagartos , Animales , Evolución Biológica , Ecosistema , Humanos , Fenotipo , Filogenia
18.
Argumentation ; 35(1): 101-139, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33678987

RESUMEN

Argument schemes are abstractions substantiating the inferential connection between premise(s) and conclusion in argumentative communication. Identifying such conventional patterns of reasoning is essential to the interpretation and evaluation of argumentation. Whether studying argumentation from a theory-driven or data-driven perspective, insight into the actual use of argumentation in communicative practice is essential. Large and reliably annotated corpora of argumentative discourse to quantitatively provide such insight are few and far between. This is all the more true for argument scheme corpora, which tend to suffer from a combination of limited size, poor validation, and the use of ad hoc restricted typologies. In the current paper, we describe the annotation of schemes on the basis of two distinct classifications: Walton's taxonomy of argument schemes, and Wagemans' Periodic Table of Arguments. We describe the annotation procedure for each, and the quantitative characteristics of the resulting annotated text corpora. In doing so, we extend the annotation of the preexisting US2016 corpus of televised election debates, resulting in, to the best of our knowledge, the two largest consistently annotated corpora of schemes in argumentative dialogue publicly available. Based on evaluation in terms of inter-annotator agreement, we propose further improvements to the guidelines for annotating schemes: the argument scheme key, and the Argument Type Identification Procedure.

20.
Small ; 16(45): e2002885, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32945097

RESUMEN

High demand for green ecosystems has urged the human community to reconsider and revamp the traditional way of synthesis of several compounds. Ammonia (NH3 ) is one such compound whose applications have been extended from fertilizers to explosives and is still being synthesized using the high energy inhaling Haber-Bosch process. Carbon free electrocatalytic nitrogen reduction reaction (NRR) is considered as a potential replacement for the Haber-Bosch method. However, it has few limitations such as low N2 adsorption, selectivity (competitive HER reactions), low yield rate etc. Since it is at the early stage, tremendous efforts have been devoted in understanding the reaction mechanism and screening of the electrocatalysts and electrolytes. In this review, the electrocatalysts are classified based on the periodic table with heat maps of Faraday efficiency and yield rate of NH3 in NRR and their electrocatalytic properties toward NRR are discussed. Also, the activity of each element is discussed and short tables and concise graphs are provided to enable the researchers to understand recent progress on each element. At the end, a perspective is provided on countering the current challenges in NRR. This review may act as handbook for basic NRR understandings, recent progress in NRR, and the design and development of advanced electrocatalysts and systems.

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