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1.
Sensors (Basel) ; 24(12)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38931684

RESUMO

In recent years, the demand for efficient automation across various sectors has accelerated significantly [...].

2.
AAPS PharmSciTech ; 25(5): 127, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844724

RESUMO

The success of obtaining solid dispersions for solubility improvement invariably depends on the miscibility of the drug and polymeric carriers. This study aimed to categorize and select polymeric carriers via the classical group contribution method using the multivariate analysis of the calculated solubility parameter of RX-HCl. The total, partial, and derivate parameters for RX-HCl were calculated. The data were compared with the results of excipients (N = 36), and a hierarchical clustering analysis was further performed. Solid dispersions of selected polymers in different drug loads were produced using solvent casting and characterized via X-ray diffraction, infrared spectroscopy and scanning electron microscopy. RX-HCl presented a Hansen solubility parameter (HSP) of 23.52 MPa1/2. The exploratory analysis of HSP and relative energy difference (RED) elicited a classification for miscible (n = 11), partially miscible (n = 15), and immiscible (n = 10) combinations. The experimental validation followed by a principal component regression exhibited a significant correlation between the crystallinity reduction and calculated parameters, whereas the spectroscopic evaluation highlighted the hydrogen-bonding contribution towards amorphization. The systematic approach presented a high discrimination ability, contributing to optimal excipient selection for the obtention of solid solutions of RX-HCl.


Assuntos
Química Farmacêutica , Excipientes , Polímeros , Cloridrato de Raloxifeno , Solubilidade , Difração de Raios X , Polímeros/química , Excipientes/química , Cloridrato de Raloxifeno/química , Análise Multivariada , Difração de Raios X/métodos , Química Farmacêutica/métodos , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Microscopia Eletrônica de Varredura/métodos , Ligação de Hidrogênio , Cristalização/métodos
3.
J Prosthet Dent ; 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38704322

RESUMO

STATEMENT OF PROBLEM: The gingival zenith (GZ) influences the line angle position in the emergence profile and the axial inclination of the crown. Irregularities in GZ symmetry and contour have a negative impact on dental esthetics. GZ location is not consistently distal to the crown's long axis; instead, it tends to be more distal in anterior teeth. The GZ levelling of the lateral incisor is often described as either level with or slightly above the zenith line connecting the central incisor and canine teeth, but there are also reports of GZ being aligned apically to the zenith line. Controversial reports persist regarding GZ positioning, magnitude, and location, potentially leading to inadequate positioning and levelling of the GZ in esthetic restorative therapy. PURPOSE: The purpose of this systematic review and meta-analysis was to assess the scientific evidence related to GZ level, position, and symmetry in maxillary incisors and canines. MATERIAL AND METHODS: This study adhered to the population, variable, outcome (PVO) criteria and the preferred reporting items for systematic reviews and meta-analysis (PRISMA) checklist. Cross-sectional studies involving healthy adults with complete dentition of the maxillary anterior sextant were subjected to prevalence analysis and quantitative measurement to assess the gingival zenith level and position. Data were extracted, and methodological quality was appraised using the Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Certainty of evidence was evaluated through the grading of recommendations, assessment, development, and evaluation (GRADE) system. RESULTS: The GZs were distally positioned, coinciding with the tooth axis or mesially positioned in, respectively, 96%, 3%, and 1% on central incisors; 84%, 14%, and 1% on lateral incisors; and 43%, 44%, and 5% on canines. GZ distal positioning was greater in central incisors, followed by lateral incisors and canines. In lateral incisors, the GZ was levelled coronally in 82% of the population. Contralateral symmetry was observed for GZ levelling and positioning. The certainty of the evidence was very low for all comparisons. CONCLUSIONS: The frequency and magnitude of the distal position of the GZ increased the more anterior the tooth. Axially, the GZ was frequently levelled coronally to the zenith line. The contralateral positioning and levelling of the GZ was symmetrical.

5.
Sensors (Basel) ; 24(7)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38610495

RESUMO

In mobile robotics, LASER scanners have a wide spectrum of indoor and outdoor applications, both in structured and unstructured environments, due to their accuracy and precision. Most works that use this sensor have their own data representation and their own case-specific modeling strategies, and no common formalism is adopted. To address this issue, this manuscript presents an analytical approach for the identification and localization of objects using 2D LiDARs. Our main contribution lies in formally defining LASER sensor measurements and their representation, the identification of objects, their main properties, and their location in a scene. We validate our proposal with experiments in generic semi-structured environments common in autonomous navigation, and we demonstrate its feasibility in multiple object detection and identification, strictly following its analytical representation. Finally, our proposal further encourages and facilitates the design, modeling, and implementation of other applications that use LASER scanners as a distance sensor.

6.
Einstein (Sao Paulo) ; 22: eAO0931, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38567917

RESUMO

OBJECTIVE: This study aimed to present a temporal and spatial analysis of the 2018 measles outbreak in Brazil, particularly in the metropolitan city of Manaus in the Amazon region, and further introduce a new tool for spatial analysis. METHODS: We analyzed the geographical data of the residences of over 7,000 individuals with measles in Manaus during 2018 and 2019. Spatial and temporal analyses were conducted to characterize various aspects of the outbreak, including the onset and prevalence of symptoms, demographics, and vaccination status. A visualization tool was also constructed to display the geographical and temporal distribution of the reported measles cases. RESULTS: Approximately 95% of the included participants had not received vaccination within the past decade. Heterogeneity was observed across all facets of the outbreak, including variations in the incubation period and symptom presentation. Age distribution exhibited two peaks, occurring at one year and 18 years of age, and the potential implications of this distribution on predictive analysis were discussed. Additionally, spatial analysis revealed that areas with the highest case densities tended to have the lowest standard of living. CONCLUSION: Understanding the spatial and temporal spread of measles outbreaks provides insights for decision-making regarding measures to mitigate future epidemics.


Assuntos
Sarampo , Humanos , Lactente , Brasil/epidemiologia , Sarampo/epidemiologia , Surtos de Doenças , Vacinação , Análise Espacial
7.
Chemistry ; 30(11): e202400244, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38299452

RESUMO

Invited for the cover of this issue are the groups of Holger Braunschweig at the Julius-Maximilians-Universität Würzburg, Germany and Eufrânio N. da Silva Júnior at the Universidade Federal de Minas Gerais, UFMG, Brazil. The image depicts the electrochemical synthesis of selenium-containing BODIPY molecules with lightning symbolizing the electrifying synthetic process, while the surrounding elemental chaos hints at the red-shifted absorption and emission and the transformative photophysical properties of these new compounds. Read the full text of the article at 10.1002/chem.202303883.

8.
Dalton Trans ; 53(9): 3994-4004, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38226629

RESUMO

A three-dimensional terbium(III) coordination polymer of formula [Tb(bttb)0.5(2,5-pzdc)0.5]n (1) [H4bttb = 1,2,4,5-tetrakis(4'-carboxyphenyl)benzene and H2-2,5-pzdc = 2,5-pyrazinedicarboxylic acid] was obtained under hydrothermal conditions. The bttb4- tetraanion in 1 adopts the bridging and chelating-bridging pseudo-oxo coordination modes while the 2,5-pzdc2- dianion exhibits a rather unusual bis-bidentate bridging pseudo-oxo coordination mode, both ligands being responsible for the stiffness of the resulting 3D structure. Solid-state photoluminescent measurements illustrate that 1 exhibits remarkable green luminescence emission, the most intense band occurring in the region of 550 nm (5D4 → 7F5) with lifetimes at the millisecond scale. Thermometric performances of 1 reveal a maximum relative sensitivity (Sm) of 0.76% K-1 at 295 K (δT = 0.05 K), constituting a TbIII ratiometric solid luminescent thermometer over the physiological temperature range. Variable-temperature static (dc) magnetic susceptibility measurements for 1 in the temperature range 2.0-300 K show the expected behavior for the depopulation of the splitted mJ levels of the 7F7 ground state of the magnetically anisotropic terbium(III) ion plus a weak antiferromagnetic interaction through the carboxylate bridges. No significant out-of-phase magnetic susceptibility signals were observed for 1 in the temperature range 2.0-10.0 K, either in the absence or presence of a static dc magnetic field.

9.
Chemistry ; 30(11): e202303883, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38085637

RESUMO

We report a rapid, efficient, and scope-extensive approach for the late-stage electrochemical diselenation of BODIPYs. Photophysical analyses reveal red-shifted absorption - corroborated by TD-DFT and DLPNO-STEOM-CCSD computations - and color-tunable emission with large Stokes shifts in the selenium-containing derivatives compared to their precursors. In addition, due to the presence of the heavy Se atoms, competitive ISC generates triplet states which sensitize 1 O2 and display phosphorescence in PMMA films at RT and in a frozen glass matrix at 77 K. Importantly, the selenium-containing BODIPYs demonstrate the ability to selectively stain lipid droplets, exhibiting distinct fluorescence in both green and red channels. This work highlights the potential of electrochemistry as an efficient method for synthesizing unique emission-tunable fluorophores with broad-ranging applications in bioimaging and related fields.


Assuntos
Selênio , Estrutura Molecular , Compostos de Boro , Fluorescência , Corantes Fluorescentes
10.
BrJP ; 7: e20240027, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1557199

RESUMO

ABSTRACT BACKGROUND AND OBJECTIVES: Addressing secondary headaches in SARS-CoV-2 infection is crucial for effective management and care optimization. This review aims to synthesize data on headache characteristics and the impact of pre-existing headache conditions on these symptoms in SARS-CoV-2 infection. CONTENTS: A systematic search was conducted across multiple databases, including PubMed/Medline, Cochrane Collaboration, Web of Science, Scopus, LILACS, Embase, Open Grey, and Google Scholar, to identify studies on headache characteristics associated with SARS-CoV-2. The search focused on headache symptoms, characteristics, onset, duration, and response to treatment during and post-infection. Twenty-three studies met the inclusion criteria. Approximately 42.1% of individuals with SARS-CoV-2 reported headaches, resembling tension-type headaches and migraines. These headaches often manifested within the first three days of infection and could persist for up to four months. The data suggest that trigeminovascular activation and pro-inflammatory mediators play a significant role in headache pathogenesis, with pre-existing headache conditions exacerbating the symptoms. The importance of effective pain management strategies must be emphasized. CONCLUSION: Headache is a prevalent symptom among SARS-CoV-2 infected individuals, with significant implications for patient care. The findings emphasize the importance of recognizing headache characteristics in SARS-CoV-2 management and suggest that tailored clinical approaches are essential for effective symptom relief.


RESUMO JUSTIFICATIVA E OBJETIVOS: A abordagem das cefaleias secundárias na infecção pela SARS-CoV-2 é crucial para um manejo adequado e otimização do cuidado. Esta revisão tem como objetivo sintetizar os dados sobre as características da cefaleia e o impacto das condições pré-existentes de cefaleia sobre esses sintomas na infecção pela SARS-CoV-2. CONTEÚDO: Uma pesquisa sistemática foi realizada em vários bancos de dados, incluindo: Pubmed/Medline, Cochrane Collaboration, Web of Science, Scopus, LILACS, Embase, Open Grey e Google Scholar, com o objetivo de identificar estudos sobre as características da cefaleia associadas à SARS-CoV-2. A pesquisa se concentrou nos sintomas, nas características, no início, na duração e na resposta ao tratamento da cefaleia durante e após a infecção. Vinte e três estudos atenderam aos critérios de inclusão. Aproximadamente 42,1% dos indivíduos com SARS-CoV-2 relataram dores de cabeça, semelhantes a dores de cabeça do tipo tensional e enxaquecas. Essas cefaleias geralmente se manifestavam nos primeiros três dias de infecção e podiam persistir por até quatro meses. Os dados sugerem que a ativação trigeminovascular e os mediadores pró-inflamatórios desempenham um papel importante na patogênese da cefaleia, com condições preexistentes de cefaleia exacerbando os sintomas. A importância de estratégias eficazes de controle da dor deve ser enfatizada. CONCLUSÃO: A cefaleia é um sintoma prevalente entre os indivíduos infectados pela SARS-CoV-2, com significativas implicações no atendimento ao paciente. Os achados deste estudo enfatizam a importância do reconhecimento das características da cefaleia no manejo da SARS-CoV-2 e sugerem que abordagens clínicas personalizadas são essenciais para o alívio eficaz dos sintomas.

11.
Einstein (Säo Paulo) ; 22: eAO0931, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1550238

RESUMO

ABSTRACT Objective: This study aimed to present a temporal and spatial analysis of the 2018 measles outbreak in Brazil, particularly in the metropolitan city of Manaus in the Amazon region, and further introduce a new tool for spatial analysis. Methods: We analyzed the geographical data of the residences of over 7,000 individuals with measles in Manaus during 2018 and 2019. Spatial and temporal analyses were conducted to characterize various aspects of the outbreak, including the onset and prevalence of symptoms, demographics, and vaccination status. A visualization tool was also constructed to display the geographical and temporal distribution of the reported measles cases. Results: Approximately 95% of the included participants had not received vaccination within the past decade. Heterogeneity was observed across all facets of the outbreak, including variations in the incubation period and symptom presentation. Age distribution exhibited two peaks, occurring at one year and 18 years of age, and the potential implications of this distribution on predictive analysis were discussed. Additionally, spatial analysis revealed that areas with the highest case densities tended to have the lowest standard of living. Conclusion: Understanding the spatial and temporal spread of measles outbreaks provides insights for decision-making regarding measures to mitigate future epidemics.

12.
Front Plant Sci ; 14: 1303417, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38148869

RESUMO

Tropical forage grasses, particularly those belonging to the Urochloa genus, play a crucial role in cattle production and serve as the main food source for animals in tropical and subtropical regions. The majority of these species are apomictic and tetraploid, highlighting the significance of U. ruziziensis, a sexual diploid species that can be tetraploidized for use in interspecific crosses with apomictic species. As a means to support breeding programs, our study investigates the feasibility of genome-wide family prediction in U. ruziziensis families to predict agronomic traits. Fifty half-sibling families were assessed for green matter yield, dry matter yield, regrowth capacity, leaf dry matter, and stem dry matter across different clippings established in contrasting seasons with varying available water capacity. Genotyping was performed using a genotyping-by-sequencing approach based on DNA samples from family pools. In addition to conventional genomic prediction methods, machine learning and feature selection algorithms were employed to reduce the necessary number of markers for prediction and enhance predictive accuracy across phenotypes. To explore the regulation of agronomic traits, our study evaluated the significance of selected markers for prediction using a tree-based approach, potentially linking these regions to quantitative trait loci (QTLs). In a multiomic approach, genes from the species transcriptome were mapped and correlated to those markers. A gene coexpression network was modeled with gene expression estimates from a diverse set of U. ruziziensis genotypes, enabling a comprehensive investigation of molecular mechanisms associated with these regions. The heritabilities of the evaluated traits ranged from 0.44 to 0.92. A total of 28,106 filtered SNPs were used to predict phenotypic measurements, achieving a mean predictive ability of 0.762. By employing feature selection techniques, we could reduce the dimensionality of SNP datasets, revealing potential genotype-phenotype associations. The functional annotation of genes near these markers revealed associations with auxin transport and biosynthesis of lignin, flavonol, and folic acid. Further exploration with the gene coexpression network uncovered associations with DNA metabolism, stress response, and circadian rhythm. These genes and regions represent important targets for expanding our understanding of the metabolic regulation of agronomic traits and offer valuable insights applicable to species breeding. Our work represents an innovative contribution to molecular breeding techniques for tropical forages, presenting a viable marker-assisted breeding approach and identifying target regions for future molecular studies on these agronomic traits.

13.
Int J Oral Maxillofac Implants ; 0(0): 1-36, 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37939238

RESUMO

BACKGROUND: The clinical use of bioactive substances, such as growth factors, have significantly increased, however, potential regenerative effects derived from the addition of different growth factors to bone substitutes on maxillary sinus floor augmentation (MSA) procedures is still controversial. This systematic review (SR) aimed at answering the following question: "Do recombinant, purified and concentrated growth factors enhance the regenerative potential of particulate bone graft substitutes in maxillary sinus floor augmentation?". METHODS: Human studies comparing histomorphometric data of the outcomes of interest new bone formation, residual graft material, and fibrous tissue ratio following MSA procedures employing particulate bone grafts/substitutes in combination or not with growth factors were retrieved from PubMed/MEDLINE, Web of Science, Cochrane and Scopus online databases and complemented with a hand search. Controlled studies published in English up to December 2022 and reporting on histomorphometric data expressed as percent volume of the outcomes of interest were considered. Risk of bias was assessed, and a meta-analysis (MA) was performed to investigate the effects of supplementary growth factors on new bone formation, remaining graft particles and fibrous tissue ratio. RESULTS: Data of 613 samples from 477 patients reported in 22 publications were included. MA showed PRP or PRF resulted in 49% more new bone formation than in areas in control groups (P=0.004), and those areas supplemented with growth factors presented 57% less residual graft particles after healing (P<0.0001). A significant (P=0.03) 1.85-fold increase in connective tissue formation was noted in areas treated with rhBMP after healing. CONCLUSION: The MA provided evidence that selective supplementary growth factors may enhance new bone formation and accelerate particulate graft turnover, while rhBMP may significantly increase connective tissue formation in MSA procedures in humans.

14.
Atherosclerosis ; 382: 117283, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37774430

RESUMO

BACKGROUND AND AIMS: Redox signaling is involved in the pathophysiology of aortic aneurysm/dissection. Protein Disulfide Isomerases and its prototype PDIA1 are thiol redox chaperones mainly from endoplasmic reticulum (ER), while PDIA1 cell surface pool redox-regulates thrombosis, cytoskeleton remodeling and integrin activation, which are mechanisms involved in aortic disease. Here we investigate the roles of PDIA1 in aortic dissection. METHODS: Initially, we assessed the outcome of aortic aneurysm/dissection in transgenic PDIA1-overexpressing FVB mice using a model of 28-day exposure to lysyl oxidase inhibitor BAPN plus angiotensin-II infusion. In a second protocol, we assessed the effects of PDIA1 inhibitor isoquercetin (IQ) against aortic dissection in C57BL/6 mice exposed to BAPN for 28 days. RESULTS: Transgenic PDIA1 overexpression associated with ca. 50% (p = 0.022) decrease (vs.wild-type) in mortality due to abdominal aortic rupture and protected against elastic fiber breaks in thoracic aorta. Conversely, exposure of mice to IQ increased thoracic aorta dissection-related mortality rates, from ca. 18%-50% within 28-days (p = 0.019); elastic fiber disruption and collagen deposition were also enhanced. The structurally-related compound diosmetin, which does not inhibit PDI, had negligible effects. In parallel, stretch-tension curves indicated that IQ amplified a ductile-type of biomechanical failure vs. control or BAPN-exposed mice aortas. IQ-induced effects seemed unassociated with nonspecific antioxidant effects or ER stress. In both models, echocardiographic analysis of surviving mice suggested that aortic rupture was dissociated from progressive dilatation. CONCLUSIONS: Our data indicate a protective role of PDIA1 against aortic dissection/rupture and potentially uncovers a novel integrative mechanism coupling redox and biomechanical homeostasis in vascular remodeling.

15.
Future Med Chem ; 15(16): 1469-1489, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37650735

RESUMO

Background: Chagas disease is a life-threatening illness caused by Trypanosoma cruzi. The involvement of serine-/arginine-rich protein kinase in the T. cruzi life cycle is significant. Aims: To synthesize, characterize and evaluate the trypanocidal activity of diamides inspired by kinase inhibitor, SRPIN340. Material & Methods: Synthesis using a three-step process and characterization by infrared, nuclear magnetic resonance and high-resolution mass spectrometry were conducted. The selectivity index was obtained by the ratio of CC50/IC50 in two in vitro models. The most active compound, 3j, was evaluated using in vitro cytokine assays and assessing in vivo trypanocidal activity. Results: 3j activity in the macrophage J774 lineage showed an anti-inflammatory profile, and mice showed significantly reduced parasitemia and morbidity at low compound dosages. Conclusion: Novel diamide is active against T. cruzi in vitro and in vivo.

16.
AAPS PharmSciTech ; 24(6): 156, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37468721

RESUMO

This study sought to develop polymer-lipid hybrid solid dispersions containing the poorly soluble drug lopinavir (LPV) by hot-melt extrusion (HME). Hence, the lipid and polymeric adjuvants were selected based on miscibility and compatibility studies. Film casting was used to assess the miscibility, whereas thermal, spectroscopic, and chromatographic analyses were employed to evaluate drug-excipient compatibility. Extrudates were obtained and characterized by physicochemical tests, including in vitro LPV dissolution. Preformulation studies led to select the most appropriate materials, i.e., the polymers PVPVA and Soluplus®, the plasticizers polyethylene glycol 400 and Kolliphor® HS15, phosphatidylcholine, and sodium taurodeoxycholate. HME processing did not result in LPV degradation and significantly increased entrapment efficiency (93.8% ± 2.8 for Soluplus® extrudate against 19.8% ± 0.5 of the respective physical mixture). LPV dissolution was also increased from the extrudates compared to the corresponding physical mixtures (p < 0.05). The dissolution improvement was considerably greater for the Soluplus®-based formulation (24.3 and 2.8-fold higher than pure LPV and PVPVA-based extrudate after 120 min, respectively), which can be attributed to the more pronounced effects of HME processing on the average size and LPV solid-state properties in the Soluplus® extrudates. Transmission electron microscopy and chemical microanalysis suggested that the polymer-lipid interactions in Soluplus®-based formulation depended on thermal processing.


Assuntos
Polietilenoglicóis , Polímeros , Polímeros/química , Composição de Medicamentos/métodos , Solubilidade , Polietilenoglicóis/química , Sistemas de Liberação de Medicamentos , Lipídeos , Temperatura Alta
17.
Life (Basel) ; 13(7)2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37511803

RESUMO

Lung cancer is the leading cause of cancer mortality worldwide, and malignant melanomas are highly lethal owing to their elevated metastatic potential. Despite improvements in therapeutic approaches, cancer treatments are not completely effective. Thus, new drug candidates are continuously sought. We synthesized mono- and di-methoxylated cinnamic acid esters and investigated their antitumor potential. A cell viability assay was performed to identify promising substances against A549 (non-small-cell lung cancer) and SK-MEL-147 (melanoma) cells. (E)-2,5-dimethoxybenzyl 3-(4-methoxyphenyl)acrylate (4m), a monomethoxylated cinnamic acid derivative, was identified as the lead antitumor compound, and its antitumor potential was deeply investigated. Various approaches were employed to investigate the antiproliferative (clonogenic assay and cell cycle analysis), proapoptotic (annexin V assay), and antimigratory (wound-healing and adhesion assays) activities of 4m on A549 cells. In addition, western blotting was performed to explore its mechanism of action. We demonstrated that 4m inhibits the proliferation of A549 by promoting cyclin B downregulation and cell cycle arrest at G2/M. Antimigratory and proapoptotic activities of 4m on A549 were also observed. The antitumor potential of 4m involved its ability to modulate the mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway once phosphorylated-ERK expression was considerably reduced in response to treatment. Our findings demonstrate that 4m is a promising anticancer drug candidate.

18.
Molecules ; 28(5)2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36903333

RESUMO

Herein, we describe the synthesis, crystal structure, and electronic properties of {[K2(dmso)(H2O)5][Ni2(H2mpba)3]·dmso·2H2O}n (1) and [Ni(H2O)6][Ni2(H2mpba)3]·3CH3OH·4H2O (2) [dmso = dimethyl sulfoxide; CH3OH = methanol; and H4mpba = 1,3-phenylenebis(oxamic acid)] bearing the [Ni2(H2mpba)3]2- helicate, hereafter referred to as {NiII2}. SHAPE software calculations indicate that the coordination geometry of all the NiII atoms in 1 and 2 is a distorted octahedron (Oh) whereas the coordination environments for K1 and K2 atoms in 1 are Snub disphenoid J84 (D2d) and distorted octahedron (Oh), respectively. The {NiII2} helicate in 1 is connected by K+ counter cations yielding a 2D coordination network with sql topology. In contrast to 1, the electroneutrality of the triple-stranded [Ni2(H2mpba)3] 2- dinuclear motif in 2 is achieved by a [Ni(H2O)6]2+ complex cation, where the three neighboring {NiII2} units interact in a supramolecular fashion through four R22(10) homosynthons yielding a 2D array. Voltammetric measurements reveal that both compounds are redox active (with the NiII/NiI pair being mediated by OH- ions) but with differences in formal potentials that reflect changes in the energy levels of molecular orbitals. The NiII ions from the helicate and the counter-ion (complex cation) in 2 can be reversibly reduced, resulting in the highest faradaic current intensities. The redox reactions in 1 also occur in an alkaline medium but at higher formal potentials. The connection of the helicate with the K+ counter cation has an impact on the energy levels of the molecular orbitals; this experimental behavior was further supported by X-ray absorption near-edge spectroscopy (XANES) experiments and computational calculations.

19.
Molecules ; 28(5)2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36903471

RESUMO

In 2021, our research group published the prominent anticancer activity achieved through the successful combination of two redox centres (ortho-quinone/para-quinone or quinone/selenium-containing triazole) through a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The combination of two naphthoquinoidal substrates towards a synergetic product was indicated, but not fully explored. Herein, we report the synthesis of 15 new quinone-based derivatives prepared from click chemistry reactions and their subsequent evaluation against nine cancer cell lines and the murine fibroblast line L929. Our strategy was based on the modification of the A-ring of para-naphthoquinones and subsequent conjugation with different ortho-quinoidal moieties. As anticipated, our study identified several compounds with IC50 values below 0.5 µM in tumour cell lines. Some of the compounds described here also exhibited an excellent selectivity index and low cytotoxicity on L929, the control cell line. The antitumour evaluation of the compounds separately and in their conjugated form proved that the activity is strongly enhanced in the derivatives containing two redox centres. Thus, our study confirms the efficiency of using A-ring functionalized para-quinones coupled with ortho-quinones to obtain a diverse range of two redox centre compounds with potential applications against cancer cell lines. Here as well, it literally takes two for an efficient tango!


Assuntos
Naftoquinonas , Quinonas , Animais , Camundongos , Quinonas/química , Benzoquinonas , Naftoquinonas/química , Oxirredução , Química Click , Reação de Cicloadição
20.
Sensors (Basel) ; 23(6)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36991840

RESUMO

Localization is a crucial skill in mobile robotics because the robot needs to make reasonable navigation decisions to complete its mission. Many approaches exist to implement localization, but artificial intelligence can be an interesting alternative to traditional localization techniques based on model calculations. This work proposes a machine learning approach to solve the localization problem in the RobotAtFactory 4.0 competition. The idea is to obtain the relative pose of an onboard camera with respect to fiducial markers (ArUcos) and then estimate the robot pose with machine learning. The approaches were validated in a simulation. Several algorithms were tested, and the best results were obtained by using Random Forest Regressor, with an error on the millimeter scale. The proposed solution presents results as high as the analytical approach for solving the localization problem in the RobotAtFactory 4.0 scenario, with the advantage of not requiring explicit knowledge of the exact positions of the fiducial markers, as in the analytical approach.

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