Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.179
Filtrar
1.
Biometals ; 2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39392553

RESUMO

Some studies have demonstrated the involvement of high concentrations of copper in the manifestation of insulin resistance in individuals with obesity. The objective of this study was to evaluate the copper nutritional status and its relationship with parameters of glycemic control in women with obesity. An observational case-control clinical study involving 203 women aged between 20 and 50 years, divided into two groups: obese (n = 84) and eutrophic (n = 119). Body weight, height and waist, hip and neck circumferences, dietary copper intake, copper biomarkers, determine ceruloplasmin activity and glycemic control parameters were measured. It was observed that women with obesity had higher copper concentrations in plasma and lower concentrations in erythrocytes when compared to the control group. Analysis of glycemic control parameters revealed a statistically significant difference in fasting blood glucose (p < 0.05) between groups. The study identified a significant positive correlation between plasma copper and fasting insulin values and the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index (p < 0.05). The results of this study demonstrate that obese women have high copper concentrations in plasma and lower concentrations in erythrocytes. Furthermore, the significant positive correlation between plasma copper and fasting insulin and HOMA-IR index suggests the influence of this mineral on glycemic control parameters in obese women.

2.
J Pediatr (Rio J) ; 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39374901

RESUMO

OBJECTIVE: The aim of this study was to assess whether the micronutrients zinc and copper, provided by human milk additives, are sufficient for very low birth weight preterm infants. METHOD: A phase 1 randomized double-blind controlled trial was conducted with very low birth weight preterm infants. This is a secondary analysis of copper and zinc. Sixty-six newborns were part of the initial sample, with forty participating and reaching the final stage of the study. Inclusion criteria were: gestational age less than 37 weeks, birth weight greater than or equal to 750 g and less than or equal to 1500 g, small or appropriate for gestational age, exclusively receiving human milk at a volume greater than or equal to 100 mL per kilogram per day, and hemodynamically stable. Participants were randomly assigned to two groups: intervention, Lioneo (received human milk with additive based on lyophilized human milk), n = 20, and control, HMCA (received human milk with commercial additive based on cow's milk protein), n = 20, and their serum levels of zinc and copper were measured on the first and twenty-first days. RESULTS: There was a reduction in intragroup zinc serum levels from the first to the twenty-first day of the study (p < 0.01). There was no intergroup difference. No difference was found in serum copper levels. CONCLUSION: Human milk additives were not sufficient to maintain adequate zinc serum levels in very low birth weight newborns. It was not possible to affirm whether human milk additives were sufficient to maintain adequate serum copper levels in the studied sample. UTN: U1111-1220-0550.

3.
Biometals ; 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39412734

RESUMO

Adipose tissue dysfunction influences the development of dyslipidemias associated with obesity, however, the mechanisms are still unclear. In this sense, the literature highlights the role of copper in cholesterol synthesis, contributing to the increase in concentrations of this lipid fraction and consequently to the manifestation of dyslipidemia. The objective of the study was to investigate the relationship between copper parameters and lipid profile markers in women with obesity. This is a cross-sectional study involving women aged 20 to 50 years divided into a case group (BMI ≥ 35 kg/m2) and a control group (BMI between 18.5 and 24.9 kg/m2). Copper concentrations in plasma and erythrocytes were determined by inductively coupled plasma optical emission spectrophotometry and ceruloplasmin activity by spectrophotometry. The lipid fractions were analyzed according to the enzymatic colorimetric method, using an automatic biochemical analyzer. Participants with obesity had elevated concentrations of copper in plasma and reduced concentrations in erythrocytes compared to the control group, but there was no significant difference in ceruloplasmin activity between the groups. The research does not identify a correlation between copper parameters and serum concentrations of lipid fractions, which does not allow inferring the role of copper in the manifestation of dyslipidemia in obesity.

4.
mBio ; 15(10): e0219224, 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39324795

RESUMO

Tupanviruses, members of the family Mimiviridae, infect phagocytic cells. Particle uncoating begins inside the phagosome, with capsid opening via the stargate. The mechanism through which this opening takes place is unknown. Once phagocytized, metal ion flux control and ROS are induced to inactivate foreign particles, including viruses. Here, we studied the effect of iron ions, copper ions, and H2O2 on Tupanvirus particles. Such treatments induced stargate opening in vitro, as observed by different microscopy techniques. Metal-treated viruses were found to be non-infectious, leading to the hypothesis that stargate opening likely resulted in the release of the viral seed, which is required for infection initiation. To the best of our knowledge, this is the first description of a giant virus capsid morphological change induced by transition metals and H2O2, which may be important to describe new virulence factors and capsid uncoating mechanisms.


Assuntos
Peróxido de Hidrogênio , Oxirredução , Replicação Viral , Peróxido de Hidrogênio/farmacologia , Mimiviridae/fisiologia , Mimiviridae/genética , Capsídeo/metabolismo , Cobre/farmacologia , Cobre/metabolismo , Ferro/metabolismo , Animais , Desenvelopamento do Vírus
5.
Avian Pathol ; : 1-11, 2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39319416

RESUMO

RESEARCH HIGHLIGHTS: Supplementation with CuNP in feed and water reduced Salmonella Enteritidis count.Supplementation with CuNP did not affect intestinal integrity of broilers.CuNP did not affect weight gain or total lactic acid bacterial counts.The results demonstrate the potential of CuNP as alternative antimicrobials.

6.
Acta Crystallogr C Struct Chem ; 80(Pt 10): 627-632, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39229750

RESUMO

The binuclear paddle-wheel copper(II) complex tetrakis(µ-3,4-diethoxybenzoato-κ2O:O')bis[(ethanol-κO)copper(II)], [Cu2(C11H13O4)4(C2H6O)2], has been synthesized and characterized. In each molecule, two CuII centres are bridged in a syn-syn fashion by four equatorial 3,4-diethoxybenzoate ligands, the two axial positions being occupied by ethanol molecules. The thermal stability has been studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. The magnetic behaviour, studied by SQUID magnetometry, shows a CuII-CuII antiferromagnetic exchange interaction with 2J = -288 cm-1, a value that fits with a magnetic structure correlation established for compounds of this kind.

7.
Polymers (Basel) ; 16(17)2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39274067

RESUMO

This investigation explores the fabrication of polymer matrix nanocomposites via additive manufacturing (AM), using a UV photopolymerization resin and copper nanoparticles (Cu-NPs) with vat photopolymerization 3D printing technology. The aim in this study is to investigate the mentioned materials in different formulations in terms of inexpensive processing, the property related variability, and targeting multifunctional applications. After the AM process, samples were post-cured with UV light in order to obtain better mechanical properties. The particles and resin were mixed using an ultrasonicator, and the particle contents used were 0.0, 0.5, and 1.0 wt %. The process used in this investigation was simple and inexpensive, as the technologies used are quite accessible, from the 3D printer to the UV curing device. These formulations were characterized with scanning electron microscopy (SEM) to observe the materials' microstructure and tensile tests to quantify stress-strain derived properties. Results showed that, besides the simplicity of the process, the mixing was effective, which was observed in the scanning electron microscope. Additionally, the tensile strength was increased with the UV irradiation exposure, while the strain properties did not change significantly.

8.
Nutrients ; 16(17)2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39275132

RESUMO

Geoffroea decorticans, commonly known as Chañar, is a native Chilean plant widely used in folk medicine for its expectorant, pain relief, and antinociceptive properties. This study explored the antioxidant, cytotoxic, and protective effects of its ethanolic (EE) and aqueous (EA) seed extracts against oxidative stress induced by copper sulfate, using both in vitro and in vivo approaches. Phytochemical analyses revealed the presence of phenolic compounds and flavonoids in the extracts. High-Performance Liquid Chromatography (HPLC) coupled with Gas Chromatography-Mass Spectrometry/Mass Spectrometry (GC-MS/MS) identified significant components such as phytol, alpha-tocopherol, vitexin, and rutin, with the EE being particularly rich in phytol and vitexin. Antioxidant assays-measuring the total antioxidant capacity (TAC), reducing power, DPPH radical scavenging, and copper and iron chelation-confirmed their potent antioxidant capabilities. Both extracts were non-cytotoxic and provided protection against CuSO4-induced oxidative stress in the 3T3 cell line. Additionally, the use of Tenebrio molitor as an invertebrate model underscored the extracts' antioxidant and protective potentials, especially that of the EE. In conclusion, this study highlights the significant antioxidant and protective properties of Chañar seed extracts, particularly the ethanolic extract, in both in vitro and in vivo models.


Assuntos
Antioxidantes , Estresse Oxidativo , Extratos Vegetais , Sementes , Tenebrio , Animais , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Antioxidantes/farmacologia , Sementes/química , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Fenóis/análise , Fenóis/farmacologia , Flavonoides/farmacologia , Flavonoides/análise , Cromatografia Líquida de Alta Pressão
9.
Environ Geochem Health ; 46(11): 447, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39316304

RESUMO

Tilapia is a model fish species used as a pollution biomonitor due to its tolerance and availability in many contaminated sites. Blue tilapia Oreochromis aureus specimens (n = 320) were collected in eleven dams influenced by mining in the SE Gulf of California region (dams 1, 2 and, 3 comprise 55 mining sites; dam 4 comprises 8; dams 6, 8, 10, and 11, ≤ 6; and dams 5, 7, and 9 include 19, 20, and 16 mining sites, respectively). Cadmium, Cu, Pb, and Zn concentrations were analyzed in the muscle, liver, gills, and guts to identify metal pollution and evaluate risks and seasonal changes. The distinct tissues exhibited different metal accumulation capacities, therefore allowed develop a diagnosis comparative between the eleven dams. In general, metal concentrations were higher in dams 1, 2, 5, and 9, which are associated with more mining sites in their sub-basins. The four metals exhibited the highest levels in the tilapia liver in dams 1 and 2, which can be related to the present and past mining activity in the lower watershed (55 sites) and the geothermal activity in these dams. In general, Zn exhibited the highest level in the tilapia livers from dams 1, 2, 3, 4, 5, and 10 compared to the maximum mean (220 µg/g) concentrations previously recorded. The non-carcinogenic risks indicated that the Pb risk was enhanced when the intake was ≥ 231.5 g week-1 of tilapia muscle, indicating a potential risk of adverse health effects for the entire population.


Assuntos
Metais Pesados , Mineração , Tilápia , Poluentes Químicos da Água , Animais , Tilápia/metabolismo , Poluentes Químicos da Água/análise , Medição de Risco , Metais Pesados/análise , Fígado/metabolismo , Fígado/química , Monitoramento Biológico , Músculos/química , Músculos/metabolismo , Monitoramento Ambiental/métodos , Brânquias/metabolismo , Brânquias/química
10.
Sensors (Basel) ; 24(17)2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39275715

RESUMO

This article implements a hybrid Machine Learning (ML) model to classify stoppage events in a copper-crushing equipment, more specifically, a conveyor belt. The model combines Artificial Neural Networks (ANNs) and Support Vector Machines (SVMs) with Principal Component Analysis (PCA) to identify the type of stoppage event when they occur in an industrial sector that is significant for the Chilean economy. This research addresses the critical need to optimise maintenance management in the mining industry, highlighting the technological relevance and motivation for using advanced ML techniques. This study focusses on combining and implementing three ML models trained with historical data composed of information from various sensors, real and virtual, as well from maintenance reports that report operational conditions and equipment failure characteristics. The main objective of this study is to improve the efficiency when identifying the nature of a stoppage serving as a basis for the subsequent development of a reliable failure prediction system. The results indicate that this approach significantly increases information reliability, addressing the persistent challenges in data management within the maintenance area. With a classification accuracy of 96.2% and a recall of 96.3%, the model validates and automates the classification of stoppage events, significantly reducing dependency on interdepartmental interactions. This advancement eliminates the need for reliance on external databases, which have previously been prone to errors, missing critical data, or containing outdated information. By implementing this methodology, a robust and reliable foundation is established for developing a failure prediction model, fostering both efficiency and reliability in the maintenance process. The application of ML in this context produces demonstrably positive outcomes in the classification of stoppage events, underscoring its significant impact on industry operations.

11.
Artigo em Inglês | MEDLINE | ID: mdl-39279687

RESUMO

OBJECTIVE: We assessed whether the administration of oral ketorolac with an analgesic provides effective pain relief during placement of an intrauterine device (IUD) in nulligravid women. METHODS: We conducted a double-blinded randomised trial in the Department of Obstetrics and Gynaecology, University of Campinas Faculty of Medical Sciences, Campinas, SP, Brazil. We randomised participants who voluntarily agreed to participate to receive either one pill containing ketorolac 20 mg together with one pill containing dipyrone 300 mg, scopolamine 6.5 µg, hyoscyamine 104 µg, and homatropine 1 mg or placebo 60 min before IUD placement. The participants and providers were blinded to the randomisation group. The primary outcome was pain assessment (measured on a 0-10 visual analogue scale) during IUD placement. RESULTS: We enrolled participants and randomised them 1:1 between November 7, 2023, and January 31, 2024. We analysed 60 women in each group. There were no differences between the groups in the pain score during tenaculum placement, uterine sounding, and IUD placement, and in the overall perception of pain. However, the pain score was significantly lower 10 min after the procedure in women who received the treatment compared with women who received the placebo. CONCLUSION: Oral ketorolac associated with an analgesic administered 60 min before IUD placement was not significantly better than placebo during tenaculum placement, uterine sounding, and IUD insertion, and did not significantly reduce the overall pain perception. However, this treatment did significantly reduce pain 10 min after the procedure. TRIAL REGISTRATION: The trial was registered at Registro Brasileiro de Ensaios Clínicos (REBEC; in English: The Brazilian Registry of Clinical Trials) under number RBR-7phn8yv on November 6, 2023. https://ensaiosclinicos.gov.br/rg/RBR-7phn8yv.


Pain at IUD placement after one pill containing ketorolac 20 mg together with one analgesic pill given 60 min before placement were similar than placebo.

12.
Acta Crystallogr C Struct Chem ; 80(Pt 9): 505-513, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39177772

RESUMO

The crystal structures of two coordination compounds, (acetato-κO)(2,2'-bipyridine-κ2N,N')(1,10-phenanthroline-κ2N,N')copper(II) acetate hexahydrate, [Cu(C2H3O2)(C10H8N2)(C12H8N2)](C2H3O2)·6H2O or [Cu(bipy)(phen)Ac]Ac·6H2O, and (acetato-κO)bis(2,2'-bipyridine-κ2N,N')copper(II) acetate-acetic acid-water (1/1/3), [Cu(C2H3O2)(C10H8N2)2](C2H3O2)·C2H4O2·3H2O or [Cu(bipy)2Ac]Ac·HAc·3H2O, are reported and compared with the previously published structure of [Cu(phen)2Ac]Ac·7H2O (phen is 1,10-phenanthroline, bipy for 2,2'-bipyridine, ac is acetate and Hac is acetic acid). The geometry around the metal centre is pentacoordinated, but highly distorted in all three cases. The coordination number and the geometric distortion are both discussed in detail, and all complexes belong to the space group P-1. The analysis of the geometric parameters and the Hirshfeld surface properties dnorm and curvedness provide information about the metal-ligand interactions in these complexes and allow comparison with similar systems.

13.
Int J Mol Sci ; 25(16)2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39201489

RESUMO

Triple-negative breast cancer (TNBC), accounting for 15-20% of all breast cancers, has one of the poorest prognoses and survival rates. Metastasis, a critical process in cancer progression, causes most cancer-related deaths, underscoring the need for alternative therapeutic approaches. This study explores the anti-migratory, anti-invasive, anti-tumoral, and antimetastatic effects of copper coordination compounds Casiopeína IIIia (CasIIIia) and Casiopeína IIgly (CasIIgly) on MDA-MB-231 and 4T1 breast carcinoma cell lines in vitro and in vivo. These emerging anticancer agents, mixed chelate copper(II) compounds, induce apoptosis by generating reactive oxygen species (ROS) and causing DNA damage. Whole-transcriptome analysis via gene expression arrays indicated that subtoxic concentrations of CasIIIia upregulate genes involved in metal response mechanisms. Casiopeínas® reduced TNBC cell viability dose-dependently and more efficiently than Cisplatin. At subtoxic concentrations (IC20), they inhibited random and chemotactic migration of MDA-MB-231 and 4T1 cells by 50-60%, similar to Cisplatin, as confirmed by transcriptome analysis. In vivo, CasIIIia and Cisplatin significantly reduced tumor growth, volume, and weight in a syngeneic breast cancer model with 4T1 cells. Furthermore, both compounds significantly decreased metastatic foci in treated mice compared to controls. Thus, CasIIIia and CasIIgly are promising chemotherapeutic candidates against TNBC.


Assuntos
Antineoplásicos , Cobre , Neoplasias de Mama Triplo Negativas , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Neoplasias de Mama Triplo Negativas/metabolismo , Animais , Humanos , Feminino , Cobre/química , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Quelantes/farmacologia , Apoptose/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/uso terapêutico , Movimento Celular/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Dano ao DNA/efeitos dos fármacos
14.
J Dent ; 149: 105283, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39096997

RESUMO

OBJECTIVE: The aim of this study was to evaluate the effect of an adhesive loaded with 0.2 % copper (Cu) and 5 % zinc oxide (ZnO) nanoparticles (Nps) on its adhesive properties and enzymatic activity at the hybrid layer ex vivo in a randomized clinical model. METHODS: Fifteen patients participated in this study, and a total of 30 third molars were used. Occlusal cavities (4 × 4 × 2 mm) were made in each tooth, and randomly divided into 2 groups: (i) Experimental group: commercial adhesive loaded with 0.2wt % CuNps and 5wt % ZnONps; and (ii) Control Group: non-loaded commercial adhesive. Teeth were restored with resin composite. Thirty days later, extractions were performed. Extracted teeth were longitudinally sectioned. Nps in powder were characterized by field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray (EDX) analysis. Microtensile bond strength (µTBS), degree of conversion (DC), and nanoleakeage (NL) tests were executed. In situ zymography (Zym) was performed to evaluate the gelatinolytic activity at the hybrid layer. Student's t-test (α = 0.05) was applied for all tests. RESULTS: µTBS and DC did not show significant differences (p > 0.05) between both groups. However, NL and gelatinolytic activity at the hybrid layer showed significant values (p < 0.05) for experimental group in comparison with control group. CONCLUSION: The addition of 0.2 % CuNps and 5 % ZnONps to a universal adhesive decreases NL and gelatinolytic activity at the hybrid layer, without jeopardizing its adhesive properties. SIGNIFICANCE: This randomized clinical trial with ex vivo analysis demonstrate that a commercial adhesive modified with 0.2wt % Cu and 5wt % ZnO Nps that does not affect its adhesive properties, reducing gelatinolytic activity and nanoleakage at the hybrid layer, which should contribute to an improvement of long term bonding-dentine clinical performance.


Assuntos
Resinas Compostas , Cobre , Colagem Dentária , Microscopia Eletrônica de Varredura , Resistência à Tração , Óxido de Zinco , Humanos , Óxido de Zinco/química , Cobre/química , Colagem Dentária/métodos , Resinas Compostas/química , Nanopartículas/química , Adesivos Dentinários/química , Dentina/efeitos dos fármacos , Dentina/enzimologia , Teste de Materiais , Masculino , Cimentos de Resina/química , Adulto , Feminino , Propriedades de Superfície , Cimentos Dentários/química , Dente Serotino , Restauração Dentária Permanente/métodos , Espectrometria por Raios X
15.
J Inorg Biochem ; 260: 112700, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39163715

RESUMO

The success of a classic inorganic coordination compound, Cisplatin, cis-[Pt(NH3)2Cl2], as the first anticancer metallodrug started a field of research dedicated to discovering coordination compounds with antitumor activity, encompassing various metals. Among these, copper complexes have emerged as interesting candidates to develop drugs to treat cancer. In this work, mixed ligand complexes of Cu(II) with diimines (phenanthroline or 4-methylphenanthroline) and 3-(4-hydroxyphenyl)propanoate, phenylcarboxylate or phenylacetate were synthesized. They were characterized in the solid state, including a new crystal structure of [Cu2(3-(4-hydroxyphenyl)propanoate)3(phenanthroline)2]Cl·H2O. The obtained complexes presented a variety of stoichiometries. In solution, complexes were partially dissociated in the corresponding Cu-diimine complex. The complexes bound to the DNA by partial intercalation and groove binding, as assessed by Circular Dichroism, relative viscosity change and UV-Vis titration. The cytotoxicity of the complexes was determined in vitro on MDA-MB-231, MCF-7 (human metastatic breast adenocarcinomas, the first triple negative), MCF-10A (breast nontumoral), A549 (human lung epithelial carcinoma), and MRC-5 (human nontumoral lung epithelial cells), finding an activity higher than that of Cisplatin, although with less selectivity.


Assuntos
Antineoplásicos , Complexos de Coordenação , Cobre , Fenantrolinas , Humanos , Cobre/química , Fenantrolinas/química , Fenantrolinas/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Linhagem Celular Tumoral , Ligantes , DNA/química , DNA/metabolismo , Células A549 , Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Células MCF-7
16.
Environ Sci Pollut Res Int ; 31(38): 50722-50732, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39102133

RESUMO

Copper oxide nanoparticles (CuONPs) have been produced on a large scale because they can be applied across various fields, especially in nano-enabled healthcare and agricultural products. However, the increasing use of CuONPs leads to their release and accumulation into the environment. The CuONPs uptaken by seeds and their implications on germination behavior have been reported, but little is known or understood about their impact on photosynthesis in seed tissues. To fill knowledge gaps, this study evaluated the effects of CuONP concentrations (0-300 mg L-1) on the photosynthetic activity of Inga laurina seeds. The microscopy data showed that CuONPs had an average size distribution of 57.5 ± 0.7 nm. Copper ion release and production of reactive oxygen species (ROS) by CuONPs were also evaluated by dialysis and spectroscopy experiments, respectively. CuONPs were not able to intrinsically generate ROS and released a low content of Cu2⁺ ions (4.5%, w/w). Time evolution of chlorophyll fluorescence imaging and laser-induced fluorescence spectroscopy were used to monitor the seeds subjected to nanoparticles during 168 h. The data demonstrate that CuONPs affected the steady-state maximum chlorophyll fluorescence ( F m ' ), the photochemical efficiency of photosystem II ( F v / F m ), and non-photochemical quenching ( NPQ ) of Inga laurina seeds over time. Besides, the NPQ significantly increased at the seed development stage, near the root protrusion stage, probably due to energy dissipation at this germination step. Additionally, the results indicated that CuONPs can change the oscillatory rhythms of energy dissipation of the seeds, disturbing the circadian clock. In conclusion, the results indicate that CuONPs can affect the photosynthetic behavior of I. laurina seeds. These findings open opportunities for using chlorophyll fluorescence as a non-destructive tool to evaluate nanoparticle impact on photosynthetic activity in seed tissues.


Assuntos
Cobre , Fabaceae , Fotossíntese , Sementes , Fotossíntese/efeitos dos fármacos , Sementes/efeitos dos fármacos , Fabaceae/efeitos dos fármacos , Germinação/efeitos dos fármacos , Nanopartículas , Clorofila/metabolismo
17.
Acta Crystallogr C Struct Chem ; 80(Pt 9): 458-471, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39115532

RESUMO

Chalcopyrite, the world's primary copper ore mineral, is abundant in Latin America. Copper extraction offers significant economic and social benefits due to its strategic importance across various industries. However, the hydrometallurgical route, considered more environmentally friendly for processing low-grade chalcopyrite ores, remains challenging, as does its concentration by froth flotation. This limited understanding stems from the poorly understood structure and reactivity of chalcopyrite surfaces. This study reviews recent contributions using density functional theory (DFT) calculations with periodic boundary conditions and slab models to elucidate chalcopyrite surface properties. Our analysis reveals that reconstructed surfaces preferentially expose S atoms at the topmost layer. Furthermore, some studies report the formation of disulfide groups (S22-) on pristine sulfur-terminated surfaces, accompanied by the reduction of Fe3+ to Fe2+, likely due to surface oxidation. Additionally, Fe sites are consistently identified as favourable adsorption locations for both oxygen (O2) and water (H2O) molecules. Finally, the potential of computer modelling for investigating collector-chalcopyrite surface interactions in the context of selective froth flotation is discussed, highlighting the need for further research in this area.

18.
Acta Crystallogr C Struct Chem ; 80(Pt 9): 487-496, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39158993

RESUMO

The synthesis and structural characterization of four novel supramolecular hydrogen-bonded arrangements based on self-assembly from molecular `[Cu(2,2'-biimidazole)]' modules and malonate anions are presented, namely, tetrakis(2,2'-biimidazole)di-µ-chlorido-dimalonatotricopper(II) pentahydrate, [Cu3(C3H2O4)2Cl2(C6H6N4)4]·5H2O or [Cu(H2biim)2(µ-Cl)Cu0.5(mal)]2·5H2O, aqua(2,2'-biimidazole)malonatocopper(II) dihydrate, [Cu(C3H2O4)(C6H6N4)(H2O)]·2H2O or [Cu(H2biim)(mal)(H2O)]·2H2O, bis[aquabis(2,2'-biimidazole)copper(II)] dimalonatodiperchloratocopper(II) 2.2-hydrate, [Cu(C6H6N4)2(H2O)]2[Cu(C3H2O4)(ClO4)2]·2.2H2O or [Cu(H2biim)2(H2O)]2[Cu(mal)2(ClO4)2]·2.2H2O, and bis(2,2'-biimidazole)copper(II) bis[bis(2,2'-biimidazole)(2-carboxyacetato)malonatocopper(II)] tridecahydrate, [Cu(C6H6N4)2][Cu(C3H2O4)(C3H3O4)(C6H6N4)2]·13H2O or [Cu(H2biim)2][Cu(H2biim)2(Hmal)(mal)]2·13H2O. These assemblies are characterized by self-complementary donor-acceptor molecular interactions, demonstrating a recurrent and distinctive pattern of hydrogen-bonding preferences among the carboxylate, carboxylic acid and N-H groups of the coordinated 2,2'-biimidazole and malonate ligands. Additionally, coordination of the carboxylate group with the metallic centre helps sustain remarkable supramolecular assemblies, such as layers, helices, double helix columns or 3D channeled architectures, including mixed-metal complexes, into a single structure.

19.
Chembiochem ; : e202400373, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39121373

RESUMO

New therapeutic strategies for osteosarcoma (OS) have demonstrated the potential efficacy of copper compounds as anticancer drugs and as a substitute for the often used platinum compounds. OS is a type of bone cancer, primarily affecting young adults and children.The main objective of this work is to discover the molecular targets and cellular pathways related to the antitumor properties of a Cu(II)-hydrazone toward human OS 2D and 3D systems. Cell viability study using MG-63 cells was evaluated in OS monolayer and spheroids. CuHL significantly reduced cell viability in OS models (IC50 2D: 2.6±0.3 µM; IC50 3D: 9.9±1.4 µM) (p<0.001). Also, CuHL inhibits cell proliferation and it induces cells to apoptosis. The main mechanism of action found for CuHL are the interaction with DNA, genotoxicity, the ROS generation and the proteasome activity inhibition. Besides, 67 differentially expressed proteins were found using proteomic approaches. Of those 67 proteins, 40 were found overexpressed and 27 underexpressed. The response to stress and to unfolded protein, as well as ATP synthesis were the most affected biological process among upregulated proteins, whilst proteins related to DNA replication and redox homeostasis were downregulated.

20.
Nanomaterials (Basel) ; 14(13)2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38998756

RESUMO

Copper selenide nanoparticles (Cu2-x Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization of copper selenide nanoparticles modified with gum arabic (GA) are reported. Also, through transmission electronic microscopy (TEM) analysis, the transformation of the morphology and particle size of copper selenide nanoparticles in aqueous solution was studied. In addition, we present an antimicrobial study with different microorganisms such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albiacans (C. albicans). Copper selenide nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry analysis (DSC) and TEM. XRD confirmed the crystal-line structure of the nanoparticles such as cubic berzelanite with a particle size of 6 nm ± 0.5. FTIR and TGA corroborated the surface modification of copper selenide nanoparticles with gum arabic, and DSC suggested a change in the structural phase from cubic to hexagonal. TEM analysis demonstrated that the surface modification of the Cu2-x Se NPs stabilized the nanostructure of the particles, preventing changes in the morphology and particle size. The antimicrobial susceptibility analysis of copper selenide nanoparticles indicated that they have the ability to inhibit the microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA