Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Cureus ; 16(5): e59994, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38854262

RESUMO

Premature graying of hair (PGH) is a multifactorial condition defined by the graying of hair before the age of 20 in Caucasians and before the age of 30 in African Americans. Although the etiology remains unknown, it has been associated with genetic predisposition, oxidative stress, nutritional deficiencies, and autoimmune diseases. Current treatment options are limited but can include anti-inflammatory medications, vitamins, and hair colorants for symptom control. In this report, we present a case of premature graying in a 32-year-old male, onset at age 15, exhibiting a distinctive fractal pattern. This case represents a unique instance of PGH characterized by an unusual pattern, necessitating further investigation into potential etiological factors and underlying pathophysiological mechanisms.

2.
Molecules ; 27(23)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36500250

RESUMO

The excellent π-accepting azodicarboxylic esters adcOR (R = Et, iPr, tBu, Bn (CH2-C6H5) and Ph) and the piperidinyl amide derivative adcpip were used as bridging chelate ligands in dinuclear Re(CO)3 complexes [{Re(CO)3Cl}2(µ-adcOR)] and [{Re(CO)3Cl}2(µ-adcpip)]. From the adcpip ligand the mononuclear derivatives [Re(CO)3Cl(adcpip)] and [Re(CO)3(PPh3)(µ-adcpip)]Cl were also obtained. Optimised geometries from density functional theory (DFT) calculations show syn and anti isomers for the dinuclear fac-Re(CO)3 complexes at slightly different energies but they were not distinguishable from experimental IR or UV-Vis absorption spectroscopy. The electrochemistry of the adc complexes showed reduction potentials slightly below 0.0 V vs. the ferrocene/ferrocenium couple. Attempts to generate the radicals [{Re(CO)3Cl}2(µ-adcOR)]•- failed as they are inherently unstable, losing very probably first the Cl- coligand and then rapidly cleaving one [Re(CO)3] fragment. Consequently, we found signals in EPR very probably due to mononuclear radical complexes [Re(CO)3(solv)(adc)]•. The underlying Cl-→solvent exchange was modelled for the mononuclear [Re(CO)3Cl(adcpip)] using DFT calculations and showed a markedly enhanced Re-Cl labilisation for the reduced compared with the neutral complex. Both the easy reduction with potentials ranging roughly from -0.2 to -0.1 V for the adc ligands and the low-energy NIR absorptions in the 700 to 850 nm range place the adc ligands with their lowest-lying π* orbital being localised on the azo function, amongst comparable bridging chelate N^N coordinating ligands with low-lying π* orbitals of central azo, tetrazine or pyrazine functions. Comparative (TD)DFT-calculations on the Re(CO)3Cl complexes of the adcpip ligand using the quite established basis set and functionals M06-2X/def2TZVP/LANL2DZ/CPCM(THF) and the more advanced TPSSh/def2-TZVP(+def2-ECP for Re)/CPCMC(THF) for single-point calculations with BP86/def2-TZVP(+def2-ECP for Re)/CPCMC(THF) optimised geometries showed a markedly better agreement of the latter with the experimental XRD, IR and UV-Vis absorption data.


Assuntos
Rênio , Rênio/química , Ligantes , Análise Espectral , Eletroquímica
3.
ChemMedChem ; 12(6): 456-465, 2017 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-28195406

RESUMO

Cyclometalated rollover complexes of the type [PtMe(κ2 N,C-bipyO-H)(L)] [bipyO-H=cyclometalated 2,2'-bipyridine N-oxide; L=tricyclohexylphosphine (PCy3 , 2 a), 2-(diphenylphosphino)pyridine (PPh2 py, 2 b), P(OPh)3 (2 c)] were synthesized by treating [PtMe(κ2 N,C-bipyO-H)(SMe2 )] (1) with various monodentate phosphine and phosphite ligands. These complexes were characterized by NMR spectroscopy, and the structure of 2 a was confirmed by single-crystal X-ray diffraction. Complex 1 was treated with bis(diphenylphosphino)methane (dppm) at a 1:1 ratio to give the corresponding [PtMe(κ2 N,C-bipyO-H)(κ1 P-dppm)] (3 b) complex, in which the dppm ligand acts as a monodentate pendant ligand. The biological activities of these complexes were evaluated against a panel of four standard cancer cell lines: lung carcinoma (A549), ovarian carcinoma (OV-90 and SKOV3), and breast carcinoma (MCF-7). Complexes 2 c and especially 3 b indicated effective potent cytotoxic activity regarding the cell lines. Electrophoresis mobility shift assays and molecular-modeling investigations were performed to determine the specific binding mode and the binding orientation of these alkylating agents to DNA. Detection of cellular reactive oxygen species was also determined.


Assuntos
Complexos de Coordenação/síntese química , DNA/metabolismo , Platina/química , 2,2'-Dipiridil/química , Células A549 , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/metabolismo , Complexos de Coordenação/toxicidade , DNA/química , Humanos , Células MCF-7 , Conformação Molecular , Simulação de Acoplamento Molecular , Conformação de Ácido Nucleico , Espécies Reativas de Oxigênio/metabolismo , Termodinâmica
4.
Dalton Trans ; 46(6): 2013-2022, 2017 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-28116396

RESUMO

The preparation and characterization of new heteronuclear-platinum(ii) complexes containing a 1,1'-bis(diphenylphosphino)ferrocene (dppf) ligand are described. The reaction of the known starting complex [PtMe(κ2N,C-bipyO-H)(SMe2)], A, in which bipyO-H is a cyclometalated rollover 2,2'-bipyridine N-oxide, with the dppf ligand in a 2 : 1 ratio or an equimolar ratio led to the formation of the corresponding binuclear complex [Pt2Me2(κ2N,C-bipyO-H)2(µ-dppf)], 1, or the mononuclear complex [PtMe(κ1C-bipyO-H)(dppf)], 2, respectively. According to the reaction conditions, the dppf ligand in 1 and 2 behaves as either a bridging or chelating ligand. All complexes were characterized by NMR spectroscopy. The solid-state structure of 2 was determined by the single-crystal X-ray diffraction method and it was shown that the chelating dppf ligand in this complex was arranged in a "synclinal-staggered" conformation. Also, the occurrence of intermolecular C-HCpObipyO-H interactions in the solid-state gave rise to an extended 1-D network. The electronic absorption spectra and the electrochemical behavior of these complexes are discussed. Density functional theory (DFT) was used for geometry optimization of the singlet states in solution and for electronic structure calculations. The analysis of the molecular orbital (MO) compositions in terms of occupied and unoccupied fragment orbitals in 2 was performed.

5.
J Am Psychiatr Nurses Assoc ; 23(1): 50-60, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27738085

RESUMO

BACKGROUND: Mothers who abuse substances are more likely to have impaired parenting and lose custody of their young children. OBJECTIVE: The pilot study described mother-child relational quality of women in substance abuse treatment. The identification of mothers' perceptions of being parented, current level of depression, discrete and potentially modifiable mothering behaviors, and self-appraisals of their role. DESIGN: The descriptive study implemented audio-video-recorded mother-child interactions for coding. RESULTS: Twenty-nine dyads participated with children age 4 weeks to 5 years. Mothers had lower levels of caring from their parents and moderate depression that was correlated with many of the relational quality behaviors. Eleven of 29 maternal behaviors were coded as concerning. Reflections by mothers revealed modest, yet confident self-appraisals of their maternal role. CONCLUSIONS: Women who experienced higher depression demonstrated lower maternal quality. Some maternal behaviors were identified as less optimal although many were strengths.


Assuntos
Comportamento Materno/psicologia , Relações Mãe-Filho/psicologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Projetos Piloto
6.
J Addict Nurs ; 25(1): 48-55, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24613951

RESUMO

BACKGROUND: Mothers who abuse substances are likely to have insecure emotional attachment with their children, placing their children at risk for social-emotional and psychiatric conditions. Sobriety does not inevitably improve parenting. OBJECTIVES: We tested recruitment methods, audiovisual (AV) recording procedures, the protocol for identifying child abuse risk, the coding of mother-child interactions, and retention of the sample for repeated measures as the first phase in examining mother-child relational quality of women in substance abuse treatment. DESIGN: This innovative study involved AV recordings to capture the in-vivo mother-child interactional behaviors that were later coded and analyzed for mean scores on the 64-item Parent-Child Relational Quality Assessment. Repeated measurement was planned during treatment and two months after discharge from treatment. RESULTS: The pilot involved a small sample (n = 11) of mother-child (<6 years) dyads. Highest and lowest ratings of interaction behaviors were identified. Mothers showed less enthusiasm and creativity but matched their child's emotional state. The children showed appropriate motor skill items and attachment behaviors. The dyad coding showed less mutual enjoyment between the mother and child. Eight of the participants could not be located for the second measurement despite multiple contact methods. CONCLUSIONS: AV recordings capture rich, descriptive information that can be coded for interactional quality analysis. Repeated measurement with this cohort was not feasible, thus needing to assess for additional/more frequent contacts to maintain the sample.


Assuntos
Relações Mãe-Filho , Mães/psicologia , Apego ao Objeto , Poder Familiar/psicologia , Transtornos Relacionados ao Uso de Substâncias/terapia , Adulto , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Projetos Piloto , Centros de Tratamento de Abuso de Substâncias , Transtornos Relacionados ao Uso de Substâncias/psicologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...