Publications by authors named "Jana N"

Pyrazine (tppz) and 5-sulfosalicylic acid (HSSA) mixed-bridging Cd(II)-CP, {[Cd(HSSA)(tppz)]} (), is highly luminescent, and the emission has been quenched selectively by Al in the presence of other cations, with a limit of detection (LOD) of 43.9 nM (1.18 ppb).

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The coordination compounds featuring a {CuO} core, typically bridged by hydroxo or alkoxo groups, are particularly intriguing due to their notable magnetic properties and catalytic activity. In this study, we explored the synthesis and characterization of four new Schiff base ligands and their subsequent complexation with Cu salts, which resulted in the formation of three tetranuclear complexes: [Cu(L)]·2HO (1), [Cu(L)(HL)](Cl)(NO)·5HO (2), and [Cu(L)] (3), as well as one dinuclear complex: [Cu(L)] (4). These tetranuclear complexes all feature a {CuO} core, but with differing coordination environments around the Cu centers.

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Context: Protein secondary structure prediction is essential for understanding protein function and characteristics and can also facilitate drug discovery. Traditional methods for experimentally determining protein structures are both time-consuming and costly. Computational biology offers a viable alternative by predicting protein structures from their sequences.

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Article Synopsis
  • Cardiovascular diseases are a major health concern in Chile, being the second leading cause of death and placing a heavy economic burden on the country.
  • A Cardiometabolic Integrated Practice Unit (UPI) was established at the FUSAT Clinical Hospital to address these issues through a comprehensive healthcare approach, emphasizing prevention and rehabilitation.
  • The UPI implementation followed a structured process with five key steps, ultimately demonstrating the effectiveness of targeted healthcare strategies in improving cardiovascular health in Chile.
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In this study, a tetradentate Schiff-base ligand (HL), synthesized by the condensation of ethylenediamine with 2-hydroxy-3-methoxy-5-methylbenzaldehyde, was reacted with either manganese salts or manganese salts in the presence of various pseudohalides in methanol. This reaction resulted in the formation of five mononuclear Mn complexes: [Mn(L)(HO)](NO)·1/2HO·1/2CHOH (), [Mn(L)(HO)](ClO)·HO (), [Mn(L)(N)(HO)]·1/3HO (), [Mn(L)(NCS)(HO)] (), and [Mn(L)(HO)](dca) () (where dca is dicyanamide ion). X-ray crystallography revealed that the Mn centers adopt a hexa-coordinate pseudo-octahedral geometry, where the equatorial plane is constructed with phenoxo oxygen and imine nitrogen atoms from the Schiff base ligand, while the axial positions are occupied by water molecules or a combination of water and pseudohalides.

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Skin cancer is a critical global health issue, with millions of non-melanoma and melanoma cases diagnosed annually. Early detection is essential to improving patient outcomes, yet traditional deep learning models for skin cancer classification are often limited by the need for large, annotated datasets and extensive computational resources. The aim of this study is to address these limitations by proposing an efficient skin cancer classification framework that integrates active learning (AL) with particle swarm optimization (PSO).

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Hemin is a protoporphyrin complex of ferric ion which catalyzes HO degradation and produces reactive oxygen species (ROS). This ROS generation property induces oxidative stress to hemin-exposed cells that can lead to various situations such as intracellular Fenton reaction, ferroptosis, or autophagy. Therapeutic performance of hemin is hindered due to low bioavailability of the active monomeric form with an intact ROS generation property.

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The focus is on developing alternative molecular catalysts using main-group elements and implementing strategic improvements for sustainable hydrogen production. For this purpose, a FB corrole with a (2-(2-((4-methylphenyl)sulfonamido)ethoxy)phenyl) group inserted into the position (C-10) of the corrole, along with its high-valent (corrolato)(oxo)antimony(V) dimer, was synthesized. In the crystal structure analysis of the FB corrole and the (corrolato)(oxo)antimony(V) dimer complex, it was noted that the sulfonamido group in the ligand periphery sits atop the corrole ring.

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Clearing of toxic polyglutamine aggregates from neuronal cells is crucial for ameliorating Huntington's disease. However, such clearance is challenging, requiring the targeting of affected neuron cells in the brain, followed by the removal of polyglutamine from cells. Here we report a designed nanodrug that can be used for the ultrasound-based removal of toxic polyglutamine aggregates from neuron cells.

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With an increasing number of Biopharmaceutical Classification System (BCS) II/IV pipeline compounds, solubilizing and supersaturating formulation strategies are becoming prevalent. Beyond formulation and solid form strategies, prodrugs are also employed to overcome solubility-limited absorption of poorly water-soluble compounds. Prodrugs can potentially yield supersaturated systems upon conversion to the parent drug intraluminally and thus enhance absorption.

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Inhibition of the receptor tyrosine kinase MerTK by small molecules has the potential to augment the immune response to tumors. Potent, selective inhibitors with high levels of target engagement are needed to fully evaluate the potential use of MerTK inhibitors as cancer therapeutics. We report the discovery and optimization of a series of pyrazinamide-based type 1.

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Four air-stable one-dimensional copper(II) coordination polymers (-) with azide linkers were synthesized using tridentate NNS and NNN ligands. Single-crystal X-ray diffraction (XRD) analysis confirmed the molecular structures of , , and . In the presence of TEMPO, all four coordination polymers demonstrated effective catalytic activity for the selective aerobic oxidation of veratryl alcohol, a biomass model compound, under base-free conditions.

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Azadiradione is a brain-permeable phytochemical present in the seed of an Indian medicinal plant, Azadirachta Indica, well known as neem. Recently, this small bioactive molecule has been revealed to induce the expression of Ube3a, a ubiquitin ligase whose loss and gain of function are associated with two diverse neurodevelopmental disorders. Here, we report that in utero exposure to azadiradione in mice results in severe developmental disabilities.

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Despite the limited success of copper-catalyzed alkylations, (NNS)CuCl proved to be an effective catalyst for the sp C-H alkylation of fluorene with alcohols. Various primary alcohols and challenging secondary alcohols were successfully used. The practical applicability of the method was effectively tested with several post-functionalization reactions.

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We present herein magneto-structural studies of three heterometallic ZnDy complexes: [ZnDy(L)Cl(HO)](ClO)·4HO (1), [ZnDy(L)Br(HO)](ClO)·4HO (2) and [ZnDy(L)(OAc)I(HO)]I·4HO (3), utilizing a new Schiff base ligand, ,-bis(3-methoxy-5-methylsalicylidene)-1,2-diaminocyclohexane (HL). Complexes 1 and 2 exhibit remarkable magnetic relaxation behaviour with relatively high energy barriers in zero field (: 244 K for 1 and 211 K for 2) and notable hysteresis temperatures, despite the low local geometric symmetry around the central Dy ions. The SMM performance of these complexes is further enhanced under an applied magnetic field, with increasing to 309 K for 1 and 269 K for 2, positioning them as elite members within the Zn-Dy SMM family.

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Exploring the scope of biocatalytic transformations in the absence of enzyme structures without extensive experimentation is a challenging task. To expand the limited substrate capacity of carrot-mediated bioreduction and hunt for new medicinally relevant ketones with minimum cost of labor and time, we deployed a practical method inspired by ligand-based drug design. Through analyzing collected literature data and building pharmacophore and reactivity prediction models, we screened a self-built virtual library of >8000 ketones bearing the most frequently used -heterocycles and functional groups in drug discovery.

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The utilization of economical and environmentally benign transition metals in crucial catalytic processes is pivotal for sustainable advancement in synthetic organic chemistry. Iron, as the most abundant transition metal in the Earth's crust, has gained significant attention for this purpose. A combination of FeCl (5 mol%) in the presence of phenanthroline (10 mol%) and NaOBu (1.

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Eugenol, the major constituent of clove oil, has been explored as an essential natural ingredient for ages owing to its versatile pharmacological properties. However, to date, the coordination chemistry of eugenol derivatives has not been much explored. In the present work, an eugenol-based Schiff base ligand (HL) was synthesized and structurally confirmed through ESI-MS, NMR, and FT-IR spectroscopy studies.

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In the present era, the fixation of atmospheric CO is of significant importance and plays a crucial role in maintaining the balance of carbon and energy flow within ecosystems. Generally, CO fixation is carried out by autotrophic organisms; however, the scientific community has paid substantial attention to execute this process in laboratory. In this report, we synthesized two carbonato-bridged trinuclear copper(II) complexes, [Cu(L1)(μ-CO)](ClO) (1) and [Cu(L2)(μ-CO)](ClO) (2) atmospheric fixation of CO starting with Cu(ClO)·6HO and easily accessible pyridine/pyrazine-based N donor Schiff base ligands L1 and L2, respectively.

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Nanoparticles usually enter cells through energy-dependent endocytosis that involves their cytosolic entry via biomembrane-coated endosomes. In contrast, direct translocation of nanoparticles with straight access to cytosol/subcellular components without any membrane coating is limited to very selective conditions/approaches. Here we show that nanoparticles can switch from energy-dependent endocytosis to energy-independent direct membrane penetration once an amphiphile is electrostatically bound to their surface.

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Article Synopsis
  • Single-molecule localization microscopy (SMLM) is a cutting-edge technique allowing for super-resolution imaging at the nanometer level, but relies heavily on suitable fluorescent probes.
  • This study investigates two types of fluorescent carbon dots (CDs) derived from the same precursor, one red-emitting and the other green-emitting, both functioning as SMLM probes with 20 nm localization precision and 60 nm resolution.
  • The research finds that the different blinking rates of the CDs are linked to their chemical compositions, suggesting that red CDs are better for quantitative analysis while green CDs excel in high-resolution imaging, showcasing the versatility of CDs for various bioimaging applications.
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Ultrasound-based therapy is appealing as it can be used via a wireless approach at remote parts of the body including the brain. Microbubbles are commonly used in such therapy due to their highly sound-responsive property. However, the larger size of microbubbles limits selective targeting /.

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Nonendocytic cell uptake of nanomaterials is challenging, which requires specific surface chemistry and smaller particle size. Earlier works have shown that an arginine-terminated nanoparticle of <10-20 nm size shows nonendocytic uptake via direct membrane penetration. However, the roles of surface arginine density and the arginine-arginine distance at the nanoparticle surface in controlling such nonendocytic uptake mechanism is not yet explored.

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The present work describes electrocatalytic water oxidation of three monomeric copper complexes [Cu(L1)] (), [Cu(L2)(HO)] (), and [Cu(L3)] () with bis-amide tetradentate ligands: L1 = ,'-(1,2-phenylene)dipicolinamide, L2 = ,'-(4,5-dimethyl-1,2-phenylene)bis(pyrazine-2-carboxamide), L3 = ,'-(1,2-phenylene)bis(pyrazine-2-carboxamide), for the production of molecular oxygen by the oxidation of water at pH 13.0. Ligands and all complexes have been synthesized and characterized by single crystal XRD, analytical, and spectroscopic techniques.

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Article Synopsis
  • A list of 19 Myospila species from the Muscidae family in India is compiled based on new collections and existing literature.
  • A new species, Myospila himalayensis, has been identified in Darjeeling, West Bengal.
  • The study includes a detailed description of this new species and illustrated notes on its male reproductive structures and related species.
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