Introducing KICK-MEP: exploring potential energy surfaces in systems with significant non-covalent interactions.

Context: Exploring potential energy surfaces (PES) is fundamental in computational chemistry, as it provides insights into the relationship between molecular energy, geometry, and chemical reactivity. We introduce Kick-MEP, a hybrid method for exploring the PES of atomic and molecular clusters, particularly those dominated by non-covalent interactions. Kick-MEP computes the Coulomb integral between the maximum and minimum electrostatic potential values on a 0.

New Perspectives on Delocalization Pathways in Aromatic Molecular Chameleons.

This study comprehensively analyzes the magnetically induced current density of polycyclic compounds labeled as "aromatic chameleons" since they can arrange their π-electrons to exhibit aromaticity in both the ground and the lowest triplet state. These compounds comprise benzenoid moieties fused to a central skeleton with 4n π-electrons and traditional magnetic descriptors are biased due to the superposition of local magnetic responses. In the S state, our analysis reveals that the molecular constituent fragments preserve their (anti)aromatic features in agreement with two types of resonant structures: one associated with aromatic benzenoids and the other with a central antiaromatic ring.

Antioxidant activity and enzymatic of lichen substances: A study based on cyclic voltammetry and theoretical.

The antioxidant activity of nine lichen substances, including methylatrarate (1), methyl haematommate (2), lobaric acid (3), fumarprotocetraric acid (4), sphaerophorin (5), subsphaeric acid (6), diffractaic acid (7), barbatolic acid (8) and salazinic acid (9) has been determined through cyclic voltammetry. The compounds 1-4 presented slopes close to the Nernst constant of 0.059 V, indicating a 2H/2e relation between protons and electrons, as long as the compounds 5, 6, 7, 8, and 9 present slopes between 0.

Weakly Supervised Polyp Segmentation from an Attention Receptive Field Mechanism.

Colorectal cancer is the third most incidence cancer world-around. Colonoscopies are the most effective resource to detect and segment abnormal polyp masses, considered as the main biomarker of this cancer. Nonetheless, some recent clinical studies have revealed a polyp miss rate up to 26% during the clinical routine.

Dynamic Distribution of HIG2A between the Mitochondria and the Nucleus in Response to Hypoxia and Oxidative Stress.

Mitochondrial respiratory supercomplex formation requires HIG2A protein, which also has been associated with cell proliferation and cell survival under hypoxia. HIG2A protein localizes in mitochondria and nucleus. DNA methylation and mRNA expression of the gene show significant alterations in several cancers, suggesting a role for HIG2A in cancer biology.

Role of Copper on Mitochondrial Function and Metabolism.

Copper is essential for life processes like energy metabolism, reactive oxygen species detoxification, iron uptake, and signaling in eukaryotic organisms. Mitochondria gather copper for the assembly of cuproenzymes such as the respiratory complex IV, cytochrome c oxidase, and the antioxidant enzyme superoxide dismutase 1. In this regard, copper plays a role in mitochondrial function and signaling involving bioenergetics, dynamics, and mitophagy, which affect cell fate by means of metabolic reprogramming.

Erythroid Differentiation and Heme Biosynthesis Are Dependent on a Shift in the Balance of Mitochondrial Fusion and Fission Dynamics.

Erythropoiesis is the most robust cellular differentiation and proliferation system, with a production of ∼2 × 10 cells per day. In this fine-tuned process, the hematopoietic stem cells (HSCs) generate erythroid progenitors, which proliferate and mature into erythrocytes. During erythropoiesis, mitochondria are reprogrammed to drive the differentiation process before finally being eliminated by mitophagy.

Biosystem Analysis of the Hypoxia Inducible Domain Family Member 2A: Implications in Cancer Biology.

The expression of is dependent on oxygen levels, glucose concentration, and cell cycle progression. This gene encodes for protein HIG2A, found in mitochondria and the nucleus, promoting cell survival in hypoxic conditions. The genomic location of is in chromosome 5q35.

Theoretical Study of the Antioxidant Activity of Quercetin Oxidation Products.

It was recently shown that, when tested in cellular systems, quercetin oxidized products (Qox) have significantly better antioxidant activity than quercetin itself. The main Qox identified in the experiments are either 2,5,7,3',4'-pentahydroxy-3,4-flavandione or its tautomer, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2)-benzofuranone . We have now performed a theoretical evaluation of different physicochemical properties using density functional theory (DFT) calculations on and its main Qox species.

Alterations of Mitochondrial Biology in the Oral Mucosa of Chilean Children with Autism Spectrum Disorder (ASD).

Autistic Spectrum Disorder (ASD) is characterized by the impairment of socio-communicative skills and the presence of restricted and stereotyped behavior patterns. Recent researches have revealed the influence of mitochondrial physiology on the development of ASD. Several research groups have identified defects in respiratory complexes, coenzyme-Q10 deficiency, increased oxidative damage, decreased of superoxide dismutase (SOD2).

The OXPHOS supercomplex assembly factor HIG2A responds to changes in energetic metabolism and cell cycle.

HIG2A promotes cell survival under hypoxia and mediates the assembly of complex III and complex IV into respiratory chain supercomplexes. In the present study, we show that human HIGD2A and mouse Higd2a gene expressions are regulated by hypoxia, glucose, and the cell cycle-related transcription factor E2F1. The latter was found to bind the promoter region of HIGD2A.

Copper deficiency-induced anemia is caused by a mitochondrial metabolic reprograming in erythropoietic cells.

The lack of copper has been associated with anemia, myelodysplastic syndromes and leukemia as well as with a loss in complex IV activity and an enlarged mitochondrial morphology. Mitochondria play a key role during the differentiation of hematopoietic stem cells by regulating the passage from a glycolytic to oxidative metabolism. The former is associated with cell proliferation and the latter with cell differentiation.

The Interplay among PINK1/PARKIN/Dj-1 Network during Mitochondrial Quality Control in Cancer Biology: Protein Interaction Analysis.

PARKIN (E3 ubiquitin ligase ), PINK1 (PTEN induced kinase 1) and DJ-1 () are proteins involved in autosomal recessive parkinsonism, and carcinogenic processes. In damaged mitochondria, PINK1's importing into the inner mitochondrial membrane is prevented, PARKIN presents a partial mitochondrial localization at the outer mitochondrial membrane and DJ-1 relocates to mitochondria when oxidative stress increases. Depletion of these proteins result in abnormal mitochondrial morphology.

Current characteristics of tuberculosis and human immunodeficiency virus co-infection in a cohort of hospitalized patients in Medellín, Colombia.

Introduction: Tuberculosis (TB) is an important cause of morbidity and mortality in HIV patients. It is unknown if the advent of molecular diagnostic methods and a greater availability of antiretroviral therapy (ART) in our country have changed some characteristics of the TB/HIV co-infection.

Objective: To describe the epidemiology, clinical features, diagnosis, resistance patterns, tuberculosis drug effects and mortality in co-infected patients.

Which NICS method is most consistent with ring current analysis? Assessment in simple monocycles.

The aromaticity of benzene, Al cluster, cyclopropane, borazine and planar cyclooctatetraene (COT) was analyzed according to different strategies based on nucleus-independent chemical shift (NICS) computations. The analysis of NICS-components evolution along the main molecular axis seems to be the most adequate and simplest strategy to predict the aromatic or antiaromatic character of the studied systems. Moreover, the analysis of the σ- and π-electron contributions to the out-of-plane component of NICS (NICS ) leads to the same qualitative and quantitative conclusions previously obtained by the analysis of the magnetically induced ring current densities.

Incidental findings in pre-orthodontic treatment radiographs.

Objectives: To determine the frequency, radiodensity characteristics, topographic location and number per patient of incidental findings observed in radiographs taken before orthodontic treatment and to evaluate the relationship of the findings with age and sex.

Methods: This was a cross-sectional study that investigated 1,887 panoramic and lateral cephalogram radiographs from 783 patients (23.31 ± 13.

A Fukui function-guided genetic algorithm. Assessment on structural prediction of Si (n = 12-20) clusters.

Theoretical studies are essential for the structural characterization of clusters, when it comes to rationalize their unique size-dependent properties and composition. However, the rapid growth of local minima on the potential energy surface (PES), with respect to cluster size, makes the candidate identification a challenging undertaking. In this article, we introduce a hybrid strategy to explore the PES of clusters.

Proposal of a simple and effective local reactivity descriptor through a topological analysis of an orbital-weighted fukui function.

The prediction of reactivity is one of the long-standing objectives of chemistry, contributing to enforce the link between theory and experiment. In particular, the regioselectivity of aromatic molecules has motivated the proposal of different reactivity descriptors based on foundational theories, like Frontier Molecular Orbital (FMO) theory and density functional theory, to predict and rationalize such regioselectivity. This article examines cases where reactivity descriptors, based on FMO theories, are known to have failed, specifically on electrophilic aromatic substitution reactions, through a simple but effective new reactivity model: the Orbital-weighted Fukui function ( fw-(r)) and its topological analysis.

Non-cytotoxic copper overload boosts mitochondrial energy metabolism to modulate cell proliferation and differentiation in the human erythroleukemic cell line K562.

Copper is integral to the mitochondrial respiratory complex IV and contributes to proliferation and differentiation, metabolic reprogramming and mitochondrial function. The K562 cell line was exposed to a non-cytotoxic copper overload to evaluate mitochondrial dynamics, function and cell fate. This induced higher rates of mitochondrial turnover given by an increase in mitochondrial fusion and fission events and in the autophagic flux.

Revisiting Aromaticity and Chemical Bonding of Fluorinated Benzene Derivatives.

The electron delocalization of benzene (C6H6) and hexafluorobenzene (C6F6) was analyzed in terms of the induced magnetic field, nucleus-independent chemical shift (NICS), and ring current strength (RCS). The computed out-of-plane component of the induced magnetic field at a distance (r) greater than or equal to 1.0 Å above the ring center correlates well (R (2)>0.

Li7(BH)5(+): a new thermodynamically favored star-shaped molecule.

The potential energy surfaces (PESs) of Lin(BH)5(n-6) systems (where n = 5, 6, and 7) were explored using the gradient embedded genetic algorithm (GEGA) program, in order to find their global minima conformations. This search predicts that the lowest-energy isomers of Li6(BH)5 and Li7(BH)5(+) contain a (BH)5(6-) pentagonal fragment, which is isoelectronic and structurally analogous to the prototypical aromatic hydrocarbon anion C5H5(-). Li7(BH)5(+), along with Li7C5(+), Li7Si5(+) and Li7Ge5(+), joins a select group of clusters that adopt a seven-peak star-shape geometry, which is favored by aromaticity in the central five-membered ring, and by the preference of Li atoms for bridging positions.