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1.
Sci Rep ; 14(1): 11535, 2024 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773159

RESUMO

In this study, a novel method for the fabrication of hesperidin/reduced graphene oxide nanocomposite (RGOH) with the assistance of gamma rays is reported. The different RGOHs were obtained by varying hesperidin concentrations (25, 50, 100, and 200 wt.%) in graphene oxide (GO) solution. Hesperidin concentrations (25, 50, 100, and 200 wt.%) in graphene oxide (GO) were varied to produce the various RGOHs. Upon irradiation with 80 kGy from γ-Ray, the successful reduction of GO occurred in the presence of hesperidin. The reduction process was confirmed by different characterization techniques such as FTIR, XRD, HRTEM, and Raman Spectroscopy. A cytotoxicity study using the MTT method was performed to evaluate the cytotoxic-anticancer effects of arbitrary RGOH on Wi38, CaCo2, and HepG2 cell lines. The assessment of RGOH's anti-inflammatory activity, including the monitoring of IL-1B and IL-6 activities as well as NF-kB gene expression was done. In addition, the anti-invasive and antimetastatic properties of RGOH, ICAM, and VCAM were assessed. Additionally, the expression of the MMP2-9 gene was quantified. The assessment of apoptotic activity was conducted by the detection of gene expressions related to BCl2 and P53. The documentation of the JNK/SMAD4/MMP2 signaling pathway was ultimately accomplished. The findings of our study indicate that RGOH therapy has significant inhibitory effects on the JNK/SMAD4/MMP2 pathway. This suggests that it could be a potential therapeutic option for cancer.


Assuntos
Raios gama , Grafite , Hesperidina , Metaloproteinase 2 da Matriz , Nanocompostos , Proteína Smad4 , Humanos , Grafite/química , Grafite/farmacologia , Nanocompostos/química , Hesperidina/farmacologia , Hesperidina/química , Proteína Smad4/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/genética , Química Verde/métodos , Transdução de Sinais/efeitos dos fármacos , Células CACO-2 , Células Hep G2 , Linhagem Celular Tumoral , MAP Quinase Quinase 4/metabolismo
2.
Artigo em Inglês | MEDLINE | ID: mdl-36767216

RESUMO

Cyberbullying is a form of aggression in which electronic communication such as e-mails, mobile phone calls, text messages, instant messenger contacts, photos, social networking sites and personal webpages are used to threaten or intimidate individuals. Cognitive-behavioral therapy (CBT) counselling based on empathic training may reduce cyberbullying among adolescents. The present study investigated the impact of developing empathy skills in reducing cyberbullying among a sample of adolescents using two groups (i.e., an experimental group and control group). The experimental group received counselling intervention based on CBT with special focus on improving empathy whereas the control group received CBT general counselling. The participants comprised 217 adolescents (experimental group = 98 adolescents, control group = 119 adolescents) with a mean age of 15.1 years (SD ± 1.5). The measures included the Toronto Empathy Questionnaire (TEQ) and the Bullying, Cyberbullying Scale for Adolescents (BCS-A). Results showed that there were statistically significant differences on TEQ scores and BCS-A scores in the experimental and control groups after the intervention but more so in favor of the experimental group in terms of reduced levels of cyberbullying (both victimization and perpetration). Positive gains among the experimental group in both empathy and reduced cyberbullying remained at two-month follow-up. It is recommended that teachers and school counselors tackling cyberbullying should use empathy training as part of their cyberbullying prevention programs.


Assuntos
Bullying , Vítimas de Crime , Cyberbullying , Humanos , Adolescente , Empatia , Bullying/prevenção & controle , Agressão
3.
Front Psychol ; 13: 945766, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36033028

RESUMO

The present study is a differential study that describes the nature of the relationship between cooperation and altruistic behavior in a sample of gifted adolescents in three universities in Egypt and Kuwait University. It also identified the differences between males/females, and senior students/junior students in both cooperation and altruism. A total of 237 gifted adolescents-with average age 21.3 ± SD 2.6 years-from three Egyptian universities: Alexandria University, Sadat Academy for Management Sciences, and Suez University (in Egypt), and Kuwait University, were involved in this study. Measures used in the study include the Scales for Rating the Behavioral Characteristics of Superior Students (SRBCSS), Generative Altruism Scale (GAlS), and The Cooperative/Competitive Strategy Scale (CCSS). Results revealed that there is a significant positive relationship between altruism and cooperation among gifted adolescents. Also, findings show that there are statistically significant differences between males and females in both altruism and cooperation. In addition, there are differences statistically significant between senior students and junior students in both altruism and cooperation in favor of senior students. It is recommended that altruism and cooperation intervention-based programs should be designed to increase the adaptive behaviors of adolescents.

4.
Hepatology ; 76(5): 1376-1388, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35313030

RESUMO

BACKGROUND AND AIMS: Resolution of pathways that converge to induce deleterious effects in hepatic diseases, such as in the later stages, have potential antifibrotic effects that may improve outcomes. We aimed to explore whether humans and rodents display similar fibrotic signaling networks. APPROACH AND RESULTS: We assiduously mapped kinase pathways using 340 substrate targets, upstream bioinformatic analysis of kinase pathways, and over 2000 random sampling iterations using the PamGene PamStation kinome microarray chip technology. Using this technology, we characterized a large number of kinases with altered activity in liver fibrosis of both species. Gene expression and immunostaining analyses validated many of these kinases as bona fide signaling events. Surprisingly, the insulin receptor emerged as a considerable protein tyrosine kinase that is hyperactive in fibrotic liver disease in humans and rodents. Discoidin domain receptor tyrosine kinase, activated by collagen that increases during fibrosis, was another hyperactive protein tyrosine kinase in humans and rodents with fibrosis. The serine/threonine kinases found to be the most active in fibrosis were dystrophy type 1 protein kinase and members of the protein kinase family of kinases. We compared the fibrotic events over four models: humans with cirrhosis and three murine models with differing levels of fibrosis, including two models of fatty liver disease with emerging fibrosis. The data demonstrate a high concordance between human and rodent hepatic kinome signaling that focalizes, as shown by our network analysis of detrimental pathways. CONCLUSIONS: Our findings establish a comprehensive kinase atlas for liver fibrosis, which identifies analogous signaling events conserved among humans and rodents.


Assuntos
Hepatopatias , Receptor de Insulina , Humanos , Camundongos , Animais , Receptor de Insulina/metabolismo , Roedores , Cirrose Hepática/patologia , Fígado/patologia , Hepatopatias/patologia , Fibrose , Proteínas Quinases/metabolismo , Colágeno/metabolismo , Serina/metabolismo , Receptores com Domínio Discoidina/metabolismo , Treonina/metabolismo
5.
J Autism Dev Disord ; 52(11): 4774-4782, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35028807

RESUMO

The present study examined the role of IQ and the Theory of Mind understanding in children with an autism spectrum disorder and down syndrome. Sixty-six Swedish children with ASD (n = 26), DS (n = 18), and typically developed group (n = 22) ranged between 6 and 12 years old were compared on ToM tasks consisted of standard ToM and IQ tasks. SPSS 25 program was used to analyze data. The results indicated that individuals with ASD reach a better understanding of first-order ToM tasks than children with DS. This picture was the same in the TD group to show better ability than children with ASD and DS on first-order tasks, except one task which was not found significant differences. To employ second-order TD performed better than clinical groups, while, there was no significant difference between ASD and DS. The scores for the third-order task in children with ASD were significantly better than children with DS.


Assuntos
Transtorno do Espectro Autista , Síndrome de Down , Teoria da Mente , Criança , Humanos , Suécia
6.
Health Soc Care Community ; 30(2): 602-611, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-32959465

RESUMO

There is scarce knowledge about factors contributing to underlying inequalities in vaccination coverage among Pakistani children. Therefore, the main objective of this study is to measure and decompose socioeconomic inequalities in childhood vaccination coverage. Pakistan Demographic and Health Survey, version 2017-18, data were used for analysis. Bivariate association was checked through Chi-square test and concentration curve (CC) and concentration index (CI) were used to assess the existence and nature of inequality. Finally, decomposition analysis was performed to measure the contribution of different factors to the observed inequality. Our findings suggested that vaccination coverage is more concentrated among children of educated mothers (CI = 0.296) and decomposition results suggest that a substantial proportion of the inequality is explained by maternal education, wealth status, paternal education and improved sanitation (34%, 19%, 14% and 21% respectively). Also, differences are observed between regions regarding vaccination coverage. There is need of female-targeted interventions to increase maternal role in the society through better education and decision-making autonomy. Also, the policies to improve the household's wealth status should be considered.


Assuntos
Mães , Cobertura Vacinal , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Paquistão , Fatores Socioeconômicos
7.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-922832

RESUMO

@#The current study investigates the relationship among Cyberchondria severity level, health anxiety and health locus of control as a direct response for COVID-19 anxiety among Arab people in the Middle East & North Africa (MENA) and the Gulf States. The study employed four main scales; The Coronavirus Anxiety Scale Syndrome (CASS), Cyberchondria Severity Scale (CSS). Short Health Anxiety Inventory (SHAI) and the Multidimensional Health Locus of Control – Form C (MHLC-C). The study sample consists of 573 respondents from 15 Arab countries; 243 (42.4%) males and 330 (57.6%) females. Results of the study showed that there are no statistically significant differences between the study participants in the study variables; cyberchondria severity levels, health anxiety, and health locus of control during COVID-19 pandemic. In addition, findings revealed that cyberchondria severity was positively elated o health anxiety (r=0.14, p.03). The mediation simple model revealed that high levels of COVID-19 anxiety syndrome symptoms lead to increased levels of health anxiety, whereas, COVID-19 anxiety and health anxiety cannot mediate the relationship between cyberchondria and health locus of control. Based on the study results, it is recommended that individuals form different Arab countries differ in their COVID-19 anxiety syndrome symptoms which may lead to heightened levels of internet use to seek health information and health anxiety. Also, individuals are characterized by external locus of control, they view that protection from COVID-19 infection depends mainly on the external health systems and other experienced physicians.

8.
Oper Dent ; 45(5): 457b-466, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32243251

RESUMO

CLINICAL RELEVANCE: This article presents the dental restoration of a young female patient complaining of erosive dental wear using a three-step restorative technique, an alternative approach with some novel adjustments. SUMMARY: For successful tooth wear treatment, determining the etiological systemic and local factors is the main priority before deciding on effective and long-term preventive and/or therapeutic restorative approaches. In addition to professional intervention, achieving optimal outcomes requires patients to control their diet and/or gastric issues, thus minimizing the wear process. However, continuous wear constitutes the most challenging scenario, mainly when it affects young patients' dentitions. This article describes the dental restoration of posterior teeth with reestablishment of occlusal vertical dimension before treating the anterior teeth, while educating the patient and providing medical monitoring. The three-step restorative technique seems to be properly applicable in cases of significant dental compromise due mainly to erosive wear and is based on direct procedures, which can assure a reliable and feasible approach.


Assuntos
Desgaste dos Dentes , Restauração Dentária Permanente , Dieta , Feminino , Humanos , Desgaste dos Dentes/terapia , Dimensão Vertical
9.
Acta Crystallogr C Struct Chem ; 73(Pt 9): 703-709, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28872068

RESUMO

Metal-flavonolate compounds are of significant current interest as synthetic models for quercetinase enzymes and as bioactive compounds of importance to human health. Zinc-3-hydroxyflavonolate compounds, including those of quercetin, kampferol, and morin, generally exhibit bidentate coordination to a single ZnII center. The bipyridine-ligated zinc-flavonolate compound reported herein, namely bis(µ-4-oxo-2-phenyl-4H-chromen-3-olato)-κ3O3:O3,O4;κ3O3,O4:O3-bis[(2,2'-bipyridine-κ2N,N')zinc(II)] bis(perchlorate), {[Zn2(C15H9O3)2(C10H8N2)2](ClO4)2}n, (1), provides an unusual example of bridging 3-hydroxyflavonolate ligation in a dinuclear metal complex. The symmetry-related ZnII centers of (1) exhibit a distorted octahedral geometry, with weak coordination of a perchlorate anion trans to the bridging deprotonated O atom of the flavonolate ligand. Variable-concentration conductivity measurements provide evidence that, when (1) is dissolved in CH3CN, the complex dissociates into monomers. 1H NMR resonances for (1) dissolved in d6-DMSO were assigned via HMQC to the H atoms of the flavonolate and bipyridine ligands. In CH3CN, (1) undergoes quantitative visible-light-induced CO release with a quantum yield [0.004 (1)] similar to that exhibited by other mononuclear zinc-3-hydroxyflavonolate complexes. Mass spectroscopic identification of the [(bpy)2Zn(O-benzoylsalicylate)]+ ion provides evidence of CO release from the flavonol and of ligand exchange at the ZnII center.

10.
Trop Anim Health Prod ; 49(6): 1107-1115, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28497207

RESUMO

Twenty Zaraibi goat bucks were used in this experiment which lasted 3 months during summer season of Egypt. The animals were divided randomly into two equal groups. The first group was kept without treatment as control while in the second group, rumen-protected choline (RPC) at the level of 20 g/buck/day was added to the concentrate feed mixture at the morning feeding. RPC additives to diet of Zaraibi goat bucks during the period of hot summer season increased (P < 0.01) total gain and average daily gain compared to the control group. RPC increased (P < 0.05) dry matter intake and feed conversion while water intake was not affected by RPC additives. RPC increased (P < 0.05) red and white blood cell (RBC × 106, WBC × 103) counts and hemoglobin concentration and hematocrit percentage. RPC increased total protein (P < 0.05), globulin, and γ-globulin (P < 0.01). On the other hand, total lipids, total cholesterol, and triglyceride concentrations decreased (P < 0.05 and P < 0.05) while phospholipids, glucose, and choline concentrations increased (P < 0.01) due to RPC supplementation. RPC increased (P < 0.01) thyroxin and triiodothyronine, increased (P < 0.05) testosterone levels, and decreased (P < 0.01) cortisol level compared with control bucks. It is concluded that dietary RPC at the rate of 20 g daily is required for growing male goats, especially, under heat stress conditions of summer season in Egypt and showed the best results concerning the growth, feed conversion, blood metabolites, and economic efficiency.


Assuntos
Colina , Dieta/veterinária , Suplementos Nutricionais , Metabolismo Energético , Comportamento Alimentar , Cabras/fisiologia , Vitaminas , Animais , Egito , Cabras/sangue , Testes Hematológicos/veterinária , Temperatura Alta , Masculino , Distribuição Aleatória , Estações do Ano
11.
J Am Chem Soc ; 138(42): 14083-14091, 2016 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-27689754

RESUMO

A series of (dppf)Ni(ketene) complexes were synthesized and fully characterized. In the solid state, the complexes possess η2-(C,O) coordination of the ketene in an overall planar configuration. They display similar structure in solution, except in some cases, the η2-(C,C) coordination mode is also detected. A combination of kinetic analysis and DFT calculations reveals the complexes undergo thermal decomposition by isomerization from η2-(C,O) to η2-(C,C) followed by scission of the C═C bond, which is usually rate limiting and results in an intermediate carbonyl carbene complex. Subsequent rearrangement of the carbene ligand is rate limiting for electron poor and sterically large ketenes, and results in a carbonyl alkene complex. The alkene readily dissociates, affording alkenes and (dppf)Ni(CO)2. Computational modeling of the decarbonylation pathway with partial phosphine dissociation reveals the barrier is reduced significantly, explaining the instability of ketene complexes with monodentate phosphines.

12.
Inorg Chem ; 55(14): 6916-28, 2016 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-27377103

RESUMO

Aliphatic oxidative carbon-carbon bond cleavage reactions involving Cu(II) catalysts and O2 as the terminal oxidant are of significant current interest. However, little is currently known regarding how the nature of the Cu(II) catalyst, including the anions present, influence the reaction with O2. In previous work, we found that exposure of the Cu(II) chlorodiketonate complex [(6-Ph2TPA)Cu(PhC(O)CClC(O)Ph)]ClO4 (1) to O2 results in oxidative aliphatic carbon-carbon bond cleavage within the diketonate unit, leading to the formation of benzoic acid, benzoic anhydride, benzil, and 1,3-diphenylpropanedione as organic products. Kinetic studies of this reaction revealed a slow induction phase followed by a rapid decay of the absorption features of 1. Notably, the induction phase is not present when the reaction is performed in the presence of a catalytic amount of chloride anion. In the studies presented herein, a combination of spectroscopic (UV-vis, EPR) and density functional theory (DFT) methods have been used to examine the chloride and benzoate ion binding properties of 1 under anaerobic conditions. These studies provide evidence that each anion coordinates in an axial position of the Cu(II) center. DFT studies reveal that the presence of the anion in the Cu(II) coordination sphere decreases the barrier for O2 activation and the formation of a Cu(II)-peroxo species. Notably, the chloride anion more effectively lowers the barrier associated with O-O bond cleavage. Thus, the nature of the anion plays an important role in determining the rate of reaction of the diketonate complex with O2. The same type of anion effects were observed in the O2 reactivity of the simple Cu(II)-bipyridine complex [(bpy)Cu(PhC(O)C(Cl)C(O)Ph)ClO4] (3).

13.
ChemistryOpen ; 4(5): 590-4, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26491637

RESUMO

Molecules that can be used to deliver a controlled amount of carbon monoxide (CO) have the potential to facilitate investigations into the roles of this gaseous molecule in biology and advance therapeutic treatments. This has led to the development of light-induced CO-releasing molecules (photoCORMs). A goal in this field of research is the development of molecules that exhibit a combination of controlled CO release, favorable biological properties (e.g., low toxicity and trackability in cells), and structural tunability to affect CO release. Herein, we report a new biologically-inspired organic photoCORM motif that exhibits several features that are desirable in a next-generation photoCORM. We show that 3-hydroxyflavone-based compounds are easily synthesized and modified to impart changes in absorption features and quantum yield for CO release, exhibit low toxicity, are trackable in cells, and can exhibit both O2-dependent and -independent CO release reactivity.

14.
Int J Surg Case Rep ; 6C: 73-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25528029

RESUMO

INTRODUCTION: Renal vein thrombosis, a rare complication of renal transplantation, often causes graft loss. Diagnosis includes ultrasound with Doppler, and it is often treated with anticoagulation or mechanical thrombectomy. Success is improved with early diagnosis and institution of treatment. PRESENTATION OF CASE: We report here the case of a 29 year-old female with sudden development of very late-onset renal vein thrombosis after simultaneous kidney pancreas transplant. This resolved initially with thrombectomy, stenting and anticoagulation, but thrombosis recurred, necessitating operative intervention. Intraoperatively the renal vein was discovered to be compressed by a large ovarian cyst. DISCUSSION: Compression of the renal vein by a lymphocele or hematoma is a known cause of thrombosis, but this is the first documented case of compression and thrombosis due to an ovarian cyst. CONCLUSION: Early detection and treatment of renal vein thrombosis is paramount to restoring renal allograft function. Any woman of childbearing age may have thrombosis due to compression by an ovarian cyst, and screening for this possibility may improve long-term graft function in this population.

15.
J Org Chem ; 79(17): 8189-201, 2014 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-25157493

RESUMO

The crystal structure, redox electrochemical stability, and reaction chemistry of 1,4-dicyanotetrazine (DCNT) has been experimentally characterized. These experimental results were rationalized by the results of theoretical calculations of the electronic structure, spin and charge distributions, electronic absorption spectra, and electron affinity and compared with the results for related the tetracyano electron acceptors tetracyanoethylene (TCNE), 7,7,8,8-tetracyano-p-quinodimethane (TCNQ), and 2,3,5,6-tetracyanopyrazine (TCNP). DCNT is made from the dehydration of 1,2,4,5-tetrazine-3,6-dicarboxamide, and because of the unusual deep-magenta color of the dicarboxamide in the solid state, its hydrogen-bonded layered structure, electronic structure, and electronic absorption spectra were determined. The magenta color is attributed to its absorptions at 532 nm (18 800 cm(-1)), and this corresponds to normalized chromaticity coordinates of x = 0.42 and y = 0.31 in the pink/red/orange part of the 1931 CIE chromaticity diagram. In contrast with previous reports, DCNT exhibits an irreversible one-electron reduction at -0.09 V vs SCE (MeCN), and reduced forms of DCNT have yet to be isolated and characterized. In addition, the reactions of DCNT with V(CO)6, Fe(II)(C5Me5)2, and I(-) are discussed.

16.
Minerva Gastroenterol Dietol ; 60(3): 177-89, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25027705

RESUMO

Over the last decade, treatment options for chronic hepatitis B and hepatitis C infection have markedly evolved. Several Food and Drug Administration-approved drugs are now available for the treatment of chronic hepatitis B, including immunomodulators (standard and pegylated interferon alpha), nucleoside analogues (lamivudine, entecavir and telbivudine) and nucleotide analogues (adefovir dipivoxil and tenofovir). For hepatitis C, the FDA-approved therapies include peginterferon-α, ribavirin, boceprevir, telaprevir, simeprevir and sofosbuvir with expected approval of more agents in the foreseeable future. Some of these antiviral medications have been reported to have nephrotoxic effects, particularly with long-standing therapy, although the exact mechanism has not been fully elucidated. Secondary forms of glomerulonephritis that can be associated with hepatitis B and hepatitis C viral infection can further complicate the evaluation of renal failure in this population. Knowledge of the different antiviral medications and their potential nephrotoxic effects is crucial, since early identification and substitution to a different agent with withdrawal of the offending medication, may result in recovery or stabilization of renal function. Close monitoring of renal function while taking new antiviral medications is recommended, as some of the nephrotoxic effects may only appear after long-term use.


Assuntos
Antivirais/efeitos adversos , Hepatite B Crônica/tratamento farmacológico , Hepatite C Crônica/tratamento farmacológico , Nefropatias/induzido quimicamente , Antivirais/administração & dosagem , Hepatite B Crônica/complicações , Hepatite C Crônica/complicações , Humanos , Proteinúria/induzido quimicamente
17.
J Am Chem Soc ; 136(22): 7821-4, 2014 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-24826946

RESUMO

A mononuclear Cu(II) chlorodiketonate complex was prepared, characterized, and found to undergo oxidative aliphatic carbon-carbon bond cleavage within the diketonate unit upon exposure to O2 at ambient temperature. Mechanistic studies provide evidence for a dioxygenase-type C-C bond cleavage reaction pathway involving trione and hypochlorite intermediates. Significantly, the presence of a catalytic amount of chloride ion accelerates the oxygen activation step via the formation of a Cu-Cl species, which facilitates monodentate diketonate formation and lowers the barrier for O2 activation. The observed reactivity and chloride catalysis is relevant to Cu(II) halide-catalyzed reactions in which diketonates are oxidatively cleaved using O2 as the terminal oxidant. The results of this study suggest that anion coordination can play a significant role in influencing copper-mediated oxygen activation in such systems.


Assuntos
Carbono/química , Cobre/química , Halogênios/química , Cetonas/química , Catálise , Dioxigenases/química , Oxidantes/química , Oxigênio/química
18.
Inorg Chem ; 52(19): 11480-92, 2013 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24066688

RESUMO

Two new Pb(II) complexes of the amide-appended nitrogen/sulfur epppa (N-((2-ethylthio)ethyl)-N-((6-pivaloylamido-2-pyridyl)methyl)-N-((2-pyridyl)methyl)amine) chelate ligand, [(epppa)Pb(NO3)2] (4-NO3) and [(epppa)Pb(ClO4)2] (4-ClO4), were prepared and characterized. In the solid state, 4-NO3 exhibits κ(5)-epppa chelate ligand coordination as well as the coordination of two bidentate nitrate ions. In acetonitrile, 4-NO3 is a 1:1 electrolyte with a coordinated NO3(-), whereas 4-ClO4 is a 1:2 electrolyte. Treatment of 4-ClO4 with 1 equiv Me4NOH·5H2O in CH3CN:CH3OH (3:5) results in amide methanolysis in a reaction that is akin to that previously reported for the Zn(II) analogue [(epppa)Zn](ClO4)2 (3-ClO4). (1)H NMR kinetic studies of the amide methanolysis reactions of 4-ClO4 and 3-ClO4 as a function of temperature revealed free energies of activation of 21.3 and 24.5 kcal/mol, respectively. The amide methanolysis reactions of 4-ClO4 and 3-ClO4 differ in terms of the effect of the concentration of methanol (saturation kinetics for 4-ClO4; second-order behavior for 3-ClO4), the observation of a small solvent kinetic isotope effect (SKIE) only for the reaction of the Zn(II)-containing 3-ClO4, and the properties of an initial intermediate isolated from each reaction upon treatment with Me4NOH·5H2O. These experimental results, combined with computational studies of the amide methanolysis reaction pathways of 4-ClO4 and 3-ClO4, indicate that the Zn(II)-containing 3-ClO4 initially undergoes amide deprotonation upon treatment with Me4NOH·5H2O. Subsequent amide protonation from coordinated methanol yields a structure containing a coordinated neutral amide and methoxide anion from which amide cleavage can then proceed. The rate-determining step in this pathway is either amide protonation or protonation of the leaving group. The Pb(II)-containing 4-ClO4 instead directly forms a neutral amide-containing, epppa-ligated Pb(II)-OH/Pb(II)-OCH3 equilibrium mixture upon treatment with Me4NOH·5H2O in methanol. The rate-determining step in the amide methanolysis pathway of 4-ClO4 is nucleophilic attack of the Pb(II)-OCH3 moiety on the coordinated amide. Overall, it is the larger size of the Pb(II) center and the availability of coordination positions that enable direct formation of a Pb(II)-OH/Pb(II)-OCH3 mixture versus the initial amide deprotonation identified in the reaction of the Zn(II)-containing 3-ClO4.


Assuntos
Amidas/química , Complexos de Coordenação/síntese química , Chumbo/química , Teoria Quântica , Zinco/química , Complexos de Coordenação/química , Cinética , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Termodinâmica
19.
Inorg Chem ; 52(18): 10583-94, 2013 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-23981238

RESUMO

The reaction of first row transition M(II) ions with KSCN in various solvents form tetrahedral (NMe4)2[M(II)(NCS)4] (M = Fe, Co), octahedral trans-M(II)(NCS)2(Sol)4 (M = Fe, V, Ni; Sol = MeCN, THF), and K4[M(II)(NCS)6] (M = V, Ni). The reaction of M(NCS)2(OCMe2)2 (M = Cr, Mn) in MeCN and [Co(NCMe)6](BF4)2 and KSCN in acetone and after diffusion of diethyl ether form M(NCS)2(Sol)2 that structurally differ as they form one-dimensional (1-D) (M = Co; Sol = THF), two-dimensional (2-D) (M = Mn; Sol = MeCN), and three-dimensional (3-D) (M = Cr; Sol = MeCN) extended structures. 1-D Co(NCS)2(THF)2 has trans-THFs, while the acetonitriles have a cis geometry for 2- and 3-D M(NCS)2(NCMe)2 (M = Cr, Mn). 2-D Mn(NCS)2(NCMe)2 is best described as Mn(II)(µ(N,N)-NCS)(µ(N,S)-NCS)(NCMe)2 [= Mn2(µ(N,N)-NCS)2(µ(N,S)-NCS)2(NCMe)4] with the latter µ(N,S)-NCS providing the 2-D connectivity. In addition, the reaction of Fe(NCS)2(OCMe2)2 and 7,7,8,8-tetracyanoquino-p-dimethane (TCNQ) forms 2-D structured Fe(II)(NCS)2TCNQ. The magnetic behavior of 1-D Co(NCS)2(THF)2 can be modeled by a 1-D Fisher expression (H = -2JS(i)·S(j)) with g = 2.4 and J/kB = 0.68 K (0.47 cm(-1)) and exhibit weak ferromagnetic coupling. Cr(NCS)2(NCMe)2 and Fe(II)(NCS)2TCNQ magnetically order as antiferromagnets with Tc's of 37 and 29 K, respectively, while Mn(NCS)2(NCMe)2 exhibits strong antiferromagnetic coupling. M(NCS)2(THF)4 and K4[M(NCS)6] (M = V, Ni) are paramagnets with weak coupling between the octahedral metal centers.

20.
Clin Proteomics ; 10(1): 6, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23724895

RESUMO

BACKGROUND: Complex molecular events lead to development and progression of liver cirrhosis to HCC. Differentially expressed nuclear membrane associated proteins are responsible for the functional and structural alteration during the progression from cirrhosis to carcinoma. Although alterations/ post translational modifications in protein expression have been extensively quantified, complementary analysis of nuclear membrane proteome changes have been limited. Deciphering the molecular mechanism that differentiate between normal and disease state may lead to identification of biomarkers for carcinoma. RESULTS: Many proteins displayed differential expression when nuclear membrane proteome of hepatocellular carcinoma (HCC), fibrotic liver, and HepG2 cell line were assessed using 2-DE and ESI-Q-TOF MS/MS. From the down regulated set in HCC, we have identified for the first time a 15 KDa cytochrome b5A (CYB5A), ATP synthase subunit delta (ATPD) and Hemoglobin subunit beta (HBB) with 11, 5 and 22 peptide matches respectively. Furthermore, nitrosylation studies with S-nitrosocysteine followed by immunoblotting with anti SNO-cysteine demonstrated a novel and biologically relevant post translational modification of thiols of CYB5A in HCC specimens only. Immunofluorescence images demonstrated increased protein S-nitrosylation signals in the tumor cells and fibrotic region of HCC tissues. The two other nuclear membrane proteins which were only found to be nitrosylated in case of HCC were up regulated ATP synthase subunit beta (ATPB) and down regulated HBB. The decrease in expression of CYB5A in HCC suggests their possible role in disease progression. Further insight of the functional association of the identified proteins was obtained through KEGG/ REACTOME pathway analysis databases. String 8.3 interaction network shows strong interactions with proteins at high confidence score, which is helpful in characterization of functional abnormalities that may be a causative factor of liver pathology. CONCLUSION: These findings may have broader implications for understanding the mechanism of development of carcinoma. However, large scale studies will be required for further verification of their critical role in development and progression of HCC.

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