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1.
Am J Orthopsychiatry ; 94(1): 23-32, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37768606

RESUMO

Our study aimed to assess the role of social support on the impact of discrimination on psychological distress for Asian American women and men. Using the Asian American sample from the Asian American and Native Hawaiian/Pacific Islander COVID-19 Needs Assessment Study (n = 3,508), we used logistic regression to examine the moderating role of different types of social support on the relationship between discrimination and psychological distress by gender. Among Asian Americans, facing discrimination was associated with higher odds of psychological distress, and receiving emotional support was associated with lower odds of psychological distress. When examining interactions between discrimination, social support, and gender, we found that facing discrimination led to the highest odds of psychological distress for Asian American women who provided emotional support. Our findings highlight different mechanisms by which social support buffers and exacerbates the psychological burden of discrimination for Asian Americans. These findings have overall and gender-informed implications for community policies to promote mental health resilience by actively alleviating the effects of racism among Asian Americans. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Assuntos
COVID-19 , Angústia Psicológica , Racismo , Masculino , Humanos , Feminino , Asiático , Fatores Sexuais , Racismo/psicologia , Apoio Social
2.
J Health Care Poor Underserved ; 34(2): 613-624, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37464521

RESUMO

Little is known about the inpatient mental health needs of undocumented immigrants in the United States. Based on existing literature, we hypothesized that undocumented patients would have fewer psychiatric admissions than documented patients. We reviewed 2019 inpatient admission data for Hispanic/Latino patients at an urban hospital. Patients were coded as undocumented or documented using insurance proxies. Multivariable logistic regression was used to report odds ratio of admission diagnoses of interest by documentation status. There were no significant differences in psychiatric admissions between undocumented patients (2.1%) and documented patients (2.8%) (p=.77). Compared with documented counterparts, undocumented patients were more likely to be admitted for alcohol-related disorders (AOR=1.59, 95%CI=1.31-1.93) but had lower proportions of admission for substance-related disorders, mood disorders, anxiety disorders, and suicide and intentional self-inflicted injury among others. Future studies should examine factors contributing to alcohol use disorder and barriers to accessing and using mental health care.


Assuntos
Emigrantes e Imigrantes , Transtornos Mentais , Imigrantes Indocumentados , Humanos , Estados Unidos , Hospitais de Condado , Transtornos Mentais/epidemiologia , Saúde Mental
3.
J Health Care Poor Underserved ; 34(1): 263-274, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37464493

RESUMO

Undocumented immigrants may be vulnerable to poor COVID-19 outcomes, but also may be less likely to seek medical care. To our knowledge, there have not been any investigations of potential COVID-19 disparities by immigration status. We analyzed emergency department (ED) visit data from March 20, 2020 to September 30, 2020 among patients in a safety-net hospital in Los Angeles County (n=30,023). We compared the probability of COVID-19-related ED visits between undocumented immigrants and Medi-Cal patients. We also examined differences in these comparisons over time. Undocumented patients had higher odds of COVID-19-related ED visits than Medi-Cal patients (OR: 1.41, 95% CI: 1.24-1.60) for all months in the study period except September. Even in the earliest days of the pandemic, undocumented patients were more likely than Medi-Cal patients to have a COVID-19-related ED visit. Additional analyses suggest this was likely because of higher COVID-19 exposure rather than differences in ED utilization.


Assuntos
COVID-19 , Imigrantes Indocumentados , Humanos , Los Angeles/epidemiologia , COVID-19/epidemiologia , Serviço Hospitalar de Emergência , Pacientes , Estudos Retrospectivos
4.
J Inorg Biochem ; 245: 112240, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37245283

RESUMO

A one-pot chemoenzymatic approach was developed by combining Palladium-catalysis with selective cytochrome P450 enzyme oxyfunctionalization. Various iodophenyl alkanoic acids could be coupled with alkylphenyl boronic acids to generate a series of alkyl substituted biarylalkanoic acids in overall high yield. The identity of the products could be confirmed by various analytical and chromatographic techniques. Addition of an engineered cytochrome P450 heme domain mutant with peroxygenase activity upon completion of the chemical reaction resulted in the selective oxyfunctionalization of those compounds, primarily at the benzylic position. Moreover, in order to increase the biocatalytic product conversion, a reversible substrate engineering approach was developed. This involves the coupling of a bulky amino acid such as L- phenylalanine or tryptophan, to the carboxylic acid moiety. The approach resulted in a 14 to 49% overall biocatalytic product conversion increase associated with a change in regioselectivity of hydroxylation towards less favored positions.


Assuntos
Sistema Enzimático do Citocromo P-450 , Domínio Catalítico , Sistema Enzimático do Citocromo P-450/metabolismo , Biocatálise , Hidroxilação , Catálise , Especificidade por Substrato
5.
Public Health Rep ; 138(3): 535-545, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36971268

RESUMO

OBJECTIVE: Disaggregated data on the mental health of Asian/Asian American people are needed to inform public health interventions related to reports of racism during the COVID-19 pandemic. We describe the prevalence of psychological distress and unmet mental health needs among Asian/Asian American adults during the COVID-19 pandemic across various sociodemographic subgroups. METHODS: We used cross-sectional, weighted data from the US-based 2021 Asian American and Native Hawaiian/Pacific Islander COVID-19 Needs Assessment Study (unweighted n = 3508) to estimate prevalence rates of psychological distress and unmet mental health needs, overall and by nativity status. We conducted population-weighted multivariable logistic regression analyses to examine sociodemographic factors associated with these mental health outcomes. RESULTS: About one-third (1419 of 3508) of Asian/Asian American adults (32.9%; 95% CI, 30.6%-35.2%) reported psychological distress; odds of psychological distress were increased among adults who were female, trans, and nonbinary; aged 18-44 years; US-born; Cambodian; multiracial; and low income. Of those reporting psychological distress (638 of 1419), 41.8% (95% CI, 37.8%-45.8%) reported unmet mental health needs; unmet mental health needs were highest among Asian/Asian American adults who were aged 18-24 years; Korean, Japanese, and Cambodian; US-born female; non-US-born young adults; and non-US-born with ≥bachelor's degree. CONCLUSIONS: The mental health of Asian/Asian American people is an important public health concern, with some groups more vulnerable and in need of services than others. Mental health resources need to be designed for vulnerable subgroups, and cultural and systemic barriers to mental health care need to be addressed.


Assuntos
COVID-19 , Necessidades e Demandas de Serviços de Saúde , Serviços de Saúde Mental , Feminino , Humanos , Masculino , Adulto Jovem , Asiático/psicologia , COVID-19/epidemiologia , Estudos Transversais , Saúde Mental , Pandemias , Estados Unidos/epidemiologia , Adolescente , Adulto
6.
Inorg Chem ; 62(1): 3-17, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36538590

RESUMO

Metallophilic interactions between closed-shell metal centers are exemplified by d10 ions, with Au(I) aurophilic interactions as the archetype. Such an interaction extends to d8 species, and examples involving Au(III) are prevalent. Conversely, Ag(III) argentophilic interactions are uncommon. Here, we identify argentophilic interactions in silver corroles, which are authentic Ag(III) species. The crystal structure of a monomeric silver corrole is a dimer in the solid state, and the macrocycle exhibits an atypical domed conformation. In order to evaluate whether this represents an authentic metallophilic interaction or a crystal-packing artifact, the analogous cofacial or "pacman" corrole was prepared. The conformation of the monomer was recapitulated in the silver pacman corrole, exhibiting a short 3.67 Å distance between metal centers and a significant compression of the xanthene backbone. Theoretical calculations support the presence of a rare Ag(III)···Ag(III) argentophilic interaction in the pacman complex.


Assuntos
Porfirinas , Prata , Prata/química , Porfirinas/química , Conformação Molecular
7.
Community Ment Health J ; 59(4): 622-630, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36509936

RESUMO

Emergency department (ED) visits for psychiatric care in the US reportedly declined during the COVID-19 pandemic. This work, however, does not control for strong temporal patterning in visits before the pandemic and does not examine a potential "rebound" in demand for psychiatric care following the relaxation of initial societal restrictions. Here, we examine COVID-19-related perturbations in psychiatric care during and after the 1st stage of societal restrictions in the largest safety-net hospital in Los Angeles. We retrieved psychiatric ED visit data (98,888 total over 156 weeks, Jan 2018 to Dec 2020) from Los Angeles County + USC Medical Center. We applied interrupted time series methods to identify and control for autocorrelation in psychiatric ED visits before examining their relation with the 1st stage of societal restrictions (i.e., March 13 to May 8, 2020), as well as the subsequent "rebound" period of relaxed restrictions (i.e., after May 8, 2020). Psychiatric ED visits fell by 78.13 per week (i.e., 12%) during the 1st stage of societal restrictions (SD = 23.99, p < 0.01). Reductions in ED visits for alcohol use, substance use, and (to a lesser extent) anxiety disorders accounted for the overall decline. After the 1st stage of societal restrictions, however, we observe no "rebound" above expected values in psychiatric ED visits overall (coef = - 16.89, SD = 20.58, p = 0.41) or by diagnostic subtype. This pattern of results does not support speculation that, at the population level, foregoing ED care during initial societal restrictions subsequently induced a psychiatric "pandemic" of urgent visits.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Los Angeles/epidemiologia , Pandemias , Emergências , Análise de Séries Temporais Interrompida , Serviço Hospitalar de Emergência , Estudos Retrospectivos
8.
J Racial Ethn Health Disparities ; 10(4): 2020-2027, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-35982287

RESUMO

OBJECTIVE: To determine whether Latino undocumented immigrants had a steeper decline in Emergency Department (ED) utilization compared to Latino Medi-Cal patients in a Los Angeles safety-net hospital, March 13, 2020, to May 8, 2020. STUDY DESIGN: The data were extracted from patient medical records for ED visits at LAC + USC Medical Center from January 2018 to September 2020. We analyzed weekly ED encounters among undocumented Latino patients in the nine-week period after COVID was declared a national emergency. We applied time-series routines to identify and remove autocorrelation in ED encounters before examining its relation with the COVID-19 pandemic. We included Latino patients 18 years of age and older who were either on restricted or full-scope Medi-Cal (n = 230,195). RESULTS: All low-income Latino patients, regardless of immigration status, experienced a significant decline in ED utilization during the first nine weeks of the pandemic. Undocumented patients, however, experienced an even steeper decline. ED visits for this group fall below expected levels between March 13, 2020, and May 8, 2020 (coef. = - 38.67; 95% CI = - 71.71, - 5.63). When applied to the weekly mean of ED visits, this translates to a 10% reduction below expected levels in ED visits during this time period. CONCLUSION: Undocumented immigrants' health care utilization was influenced by external events that occurred early in the pandemic, such as strict stay-at-home orders and the public charge rule change. Health care institutions and local policy efforts could work to ensure that hospitals are safer spaces for undocumented immigrants to receive care without immigration concerns.


Assuntos
COVID-19 , Serviço Hospitalar de Emergência , Hispânico ou Latino , Imigrantes Indocumentados , Adolescente , Adulto , Humanos , COVID-19/epidemiologia , COVID-19/etnologia , COVID-19/terapia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Utilização de Instalações e Serviços/estatística & dados numéricos , Hispânico ou Latino/estatística & dados numéricos , Pandemias/estatística & dados numéricos , Imigrantes Indocumentados/estatística & dados numéricos , California/epidemiologia
9.
Inorg Chem ; 61(50): 20288-20298, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36459671

RESUMO

The electronic structure of copper corroles has been a topic of debate and revision since the advent of corrole chemistry. The ground state of these compounds is best described as an antiferromagnetically coupled Cu(II) corrole radical cation. In coordinating solvents, these molecules become paramagnetic, and this is often accompanied by a color change. The underlying chemistry of these solvent-induced properties is currently unknown. Here, we show that a coordinating solvent, such as pyridine, induces a change in the ground spin state from an antiferromagnetically coupled Cu(II) corrole radical cation to a ferromagnetically coupled triplet. Over time, the triplet reacts to produce a species with spectral signatures that are characteristic of the one-electron-reduced Cu(II) corrole. These observations account for the solvent-induced paramagnetism and the associated color changes that have been observed for copper corroles in coordinating solvents.


Assuntos
Cobre , Porfirinas , Cobre/química , Solventes , Porfirinas/química , Elétrons
10.
BMC Public Health ; 22(1): 1965, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36289476

RESUMO

BACKGROUND: Undocumented immigrants face barriers to health care access, which may have been exacerbated during the early days of the COVID-19 pandemic. We test whether undocumented immigrants in Los Angeles County accessed COVID-19 related medical care by examining their Emergency Department (ED) patterns through high and low periods of COVID-19 infection. If undocumented immigrants were underutilizing or foregoing health care, we expect null or weaker associations between COVID-19 cases and COVID-19 related ED visits relative to Medi-Cal patients. METHODS: We analyzed all ED visits to the Los Angeles County + University of Southern California (LAC + USC) Medical Center between March - December 2020 (n = 85,387). We conducted logistic regressions with Los Angeles County weekly COVID-19 case counts as our main independent variable and an interaction between case counts and immigration status, stratified by age (over and under 65 years). RESULTS: We found that undocumented immigrants under 65 years old had a higher odds for a COVID-19 related ED visit compared to Medi-Cal patients and that both undocumented and Medi-Cal patients had higher odds of a COVID-19 related ED visit as COVID-19 cases in Los Angeles County increased. For patients over 65 years, Medi-Cal patients actually had a weaker association between ED visits and county COVID-19 counts; as COVID-19 case counts rose, the odds of a COVID-19 related ED visit increased for the undocumented patients. CONCLUSION: While the overall likelihood of undocumented patients having a COVID-19 related ED visit varies compared to Medi-Cal patients - for younger patients, the odds is higher; for older patients, the odds is lower - it does not appear that undocumented patients underutilized the ED during the early COVID-19 pandemic relative to Medi-Cal patients. The ED may be a viable source of contact for this high-risk population for future outreach.


Assuntos
COVID-19 , Humanos , Idoso , COVID-19/epidemiologia , Pandemias , Emigração e Imigração , Serviço Hospitalar de Emergência , Acessibilidade aos Serviços de Saúde
11.
Dig Dis Sci ; 66(3): 768-774, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32236885

RESUMO

BACKGROUND: How clinical teams function varies across sites and may affect follow-up of abnormal fecal immunochemical test (FIT) results. AIMS: This study aimed to identify the characteristics of clinical practices associated with higher diagnostic colonoscopy completion after an abnormal FIT result in a multi-site integrated safety-net system. METHODS: We distributed survey questionnaires about tracking and follow-up of abnormal FIT results to primary care team members across 11 safety-net clinics from January 2017 to April 2017. Surveys were distributed at all-staff clinic meetings and electronic surveys sent to those not in attendance. Participants received up to three reminders to complete the survey. RESULTS: Of the 501 primary care team members identified, 343 (68.5%) completed the survey. In the four highest-performing clinics, nurse managers identified at least two team members who were responsible for communicating abnormal FIT results to patients. Additionally, team members used a clinic-based registry to track patients with abnormal FIT results until colonoscopy completion. Compared to higher-performing clinics, lower-performing clinics more frequently cited competing health issues (56% vs. 40%, p = 0.03) and lack of patient priority (59% vs. 37%, p < 0.01) as barriers and were also more likely to discuss abnormal results at a clinic visit (83% vs. 61%, p < 0.01). CONCLUSIONS: Our findings suggest organized and dedicated efforts to communicate abnormal FIT results and track patients until colonoscopy completion through registries is associated with improved follow-up. Increased utilization of electronic health record platforms to coordinate communication and navigation may improve diagnostic colonoscopy rates in patients with abnormal FIT results.


Assuntos
Assistência ao Convalescente/normas , Colonoscopia/normas , Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer/normas , Atenção Primária à Saúde/normas , Idoso , Estudos Transversais , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sangue Oculto , Padrões de Prática Médica/normas , Provedores de Redes de Segurança/normas , Inquéritos e Questionários , Fluxo de Trabalho
12.
Biotechnol Appl Biochem ; 67(4): 536-540, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33376255

RESUMO

Protein dimerization often occurs in many biological systems as to provide structural and functional advantages. A tris(5-iodoacetamido-1,10-phenanthroline)Ruthenium(II) complex was shown to promote the covalent dimerization of a P450 BM3 heme domain mutant containing a surface exposed non-native single cysteine residue. The formation of homodimeric species was confirmed by protein gel electrophoresis, mass spectrometry and UV-Vis spectroscopy. The dimeric species could be separated from the monomer and aggregates by size-exclusion chromatography. Docking simulation reveals a plausible structure with two proteins covalently conjugated to the inorganic compound.


Assuntos
Complexos de Coordenação/química , Sistema Enzimático do Citocromo P-450/química , Heme/química , Fenantrolinas/química , Multimerização Proteica , Rutênio/química , Substituição de Aminoácidos , Sistema Enzimático do Citocromo P-450/genética , Mutação de Sentido Incorreto , Domínios Proteicos
13.
Biodemography Soc Biol ; 65(3): 257-267, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32727275

RESUMO

In the United States, obesity has increased in prevalence over time and is strongly associated with subsequent outcomes such as diabetes mellitus (DM) and nonalcoholic fatty liver disease (NAFLD). It is unclear, however, as to how the magnitude of NAFLD risk from obesity and DM is increased in safety-net health system settings. Among the San Francisco Health Network (SFHN) patients (N = 47,211), we examined the association between Body Mass Index (BMI) and elevated liver enzyme levels, including interaction by DM status. Our findings revealed that 32.2 percent of SFHN patients were obese, and Pacific Islanders in the safety-net had the highest rates of obesity compared to other racial groups, even after using higher race-specific BMI cutoffs. In SFHN, obesity was associated with elevated liver enzymes, with the relationship stronger among those without DM. Our findings highlight how obesity is a stronger factor of NAFLD in the absence of DM, suggesting that practitioners consider screening for NAFLD among safety-net patients with obesity even if DM has not developed. These results highlight the importance of directing efforts to reduce obesity in safety-net health systems and encourage researchers to further examine effect modification between health outcomes in such populations.


Assuntos
Obesidade/terapia , Provedores de Redes de Segurança/métodos , Adolescente , Adulto , Idoso , Índice de Massa Corporal , California/epidemiologia , Comorbidade , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/etiologia , Registros Eletrônicos de Saúde/estatística & dados numéricos , Feminino , Insuficiência Hepática/epidemiologia , Insuficiência Hepática/etiologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Prevalência , Fatores de Risco , Provedores de Redes de Segurança/organização & administração , Provedores de Redes de Segurança/estatística & dados numéricos
14.
Dalton Trans ; 47(34): 11903-11908, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-29942938

RESUMO

The mechanism of oxygen activation at a dicobalt bis-µ-hydroxo core is probed by the implementation of synthetic methods to isolate reaction intermediates. Reduction of a dicobalt(iii,iii) core ligated by the polypyridyl ligand dipyridylethane naphthyridine (DPEN) by two electrons and subsequent protonation result in the release of one water moiety to furnish a dicobalt(ii,ii) center with an open binding site. This reduced core may be independently isolated by chemical reduction. Variable-temperature 1H NMR and SQUID magnetometry reveal the reduced dicobalt(ii,ii) intermediate to consist of two low spin Co(ii) centers coupled antiferromagnetically. Binding of O2 to the open coordination site of the dicobalt(ii,ii) core results in the production of an oxygen adduct, which is proposed to be a dicobalt(iii,iii) peroxo. Electrochemical studies show that the addition of two electrons results in cleavage of the O-O bond.

15.
Biochemistry ; 57(24): 3402-3415, 2018 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-29630358

RESUMO

3-Aminotyrosine (NH2Y) has been a useful probe to study the role of redox active tyrosines in enzymes. This report describes properties of NH2Y of key importance for its application in mechanistic studies. By combining the tRNA/NH2Y-RS suppression technology with a model protein tailored for amino acid redox studies (α3X, X = NH2Y), the formal reduction potential of NH2Y32(O•/OH) ( E°' = 395 ± 7 mV at pH 7.08 ± 0.05) could be determined using protein film voltammetry. We find that the Δ E°' between NH2Y32(O•/OH) and Y32(O•/OH) when measured under reversible conditions is ∼300-400 mV larger than earlier estimates based on irreversible voltammograms obtained on aqueous NH2Y and Y. We have also generated D6-NH2Y731-α2 of ribonucleotide reductase (RNR), which when incubated with ß2/CDP/ATP generates the D6-NH2Y731•-α2/ß2 complex. By multifrequency electron paramagnetic resonance (35, 94, and 263 GHz) and 34 GHz 1H ENDOR spectroscopies, we determined the hyperfine coupling (hfc) constants of the amino protons that establish RNH2• planarity and thus minimal perturbation of the reduction potential by the protein environment. The amount of Y in the isolated NH2Y-RNR incorporated by infidelity of the tRNA/NH2Y-RS pair was determined by a generally useful LC-MS method. This information is essential to the utility of this NH2Y probe to study any protein of interest and is employed to address our previously reported activity associated with NH2Y-substituted RNRs.


Assuntos
Escherichia coli/enzimologia , Ribonucleotídeo Redutases/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismo , Estrutura Molecular , Oxirredução , Ribonucleotídeo Redutases/química , Tirosina/química
16.
Chem Sci ; 8(7): 4779-4794, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29163926

RESUMO

Oxygen evolution reaction (OER) catalysts that are earth-abundant and are active and stable in acid are unknown. Active catalysts derived from Co and Ni oxides dissolve at low pH, whereas acid stable systems such as Mn oxides (MnO x ) display poor OER activity. We now demonstrate a rational approach for the design of earth-abundant catalysts that are stable and active in acid by treating activity and stability as decoupled elements of mixed metal oxides. Manganese serves as a stabilizing structural element for catalytically active Co centers in CoMnO x films. In acidic solutions (pH 2.5), CoMnO x exhibits the OER activity of electrodeposited Co oxide (CoO x ) with a Tafel slope of 70-80 mV per decade while also retaining the long-term acid stability of MnO x films for OER at 0.1 mA cm-2. Driving OER at greater current densities in this system is not viable because at high anodic potentials, Mn oxides convert to and dissolve as permanganate. However, by exploiting the decoupled design of the catalyst, the stabilizing structural element may be optimized independently of the Co active sites. By screening potential-pH diagrams, we replaced Mn with Pb to prepare CoFePbO x films that maintained the high OER activity of CoO x at pH 2.5 while exhibiting long-term acid stability at higher current densities (at 1 mA cm-2 for over 50 h at pH 2.0). Under these acidic conditions, CoFePbO x exhibits OER activity that approaches noble metal oxides, thus establishing the viability of decoupling functionality in mixed metal catalysts for designing active, acid-stable, and earth-abundant OER catalysts.

17.
Angew Chem Int Ed Engl ; 55(6): 2176-80, 2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26836345

RESUMO

The ground state electronic structure of copper corroles has been a topic of debate and revision since the advent of corrole chemistry. Computational studies formulate neutral Cu corroles with an antiferromagnetically coupled Cu(II) corrole radical cation ground state. X-ray photoelectron spectroscopy, EPR, and magnetometry support this assignment. For comparison, Cu(II) isocorrole and [TBA][Cu(CF3)4] were studied as authentic Cu(II) and Cu(III) samples, respectively. In addition, the one-electron reduction and one-electron oxidation processes are both ligand-based, demonstrating that the Cu(II) centre is retained in these derivatives. These observations underscore ligand non-innocence in copper corrole complexes.

18.
Conn Med ; 80(8): 475-478, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29782783

RESUMO

Posterior reversible encephalopathy syndrome (PRES) is one of many causes of status epilepticus (SE). Itis defined classically as a clinical radiographic entity, characterized by presentation of headache, altered mental status, visual disturbances, seizures, and typical neuroradiographic findings of symmetrical white-matter edema. Predisposing conditions include uncontrolled hypertension, eclampsia, and use of chemotherapeu- tic and immunosuppressant agents. Bevacizumab (Avastin), a monoclonal antibody against vascular endothelial growth factor (VEGF), is used in a combination with FOLFOX [FOL - Folinic acid; F - Fluorouracil (5-FU); OX - Oxaliplatin] as a first-line treatment for patients with metastatic colorectal cancer. We present a case of a 52-year-old male on systemic chemotherapy with FOLFOX and bevacizumab who presented with SE and was diagnosed with PRES. His symptoms resolved with intensive control of blood pressure and discontinuation of chemotherapy. Bevacizumab-induced vasospasm, endothelial and blood-brain-barrier dysfunction, in combination with elevated blood pressure, were likely the underlying mechanism of PRES in our patient.


Assuntos
Anti-Hipertensivos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/efeitos adversos , Hipertensão , Síndrome da Leucoencefalopatia Posterior , Estado Epiléptico , Antineoplásicos Imunológicos/administração & dosagem , Antineoplásicos Imunológicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bevacizumab/administração & dosagem , Encéfalo/diagnóstico por imagem , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Leucovorina/administração & dosagem , Leucovorina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/efeitos adversos , Administração dos Cuidados ao Paciente , Síndrome da Leucoencefalopatia Posterior/diagnóstico , Síndrome da Leucoencefalopatia Posterior/etiologia , Síndrome da Leucoencefalopatia Posterior/fisiopatologia , Síndrome da Leucoencefalopatia Posterior/terapia , Estado Epiléptico/diagnóstico , Estado Epiléptico/etiologia , Estado Epiléptico/fisiopatologia , Estado Epiléptico/terapia , Suspensão de Tratamento
19.
J Am Chem Soc ; 137(47): 14887-904, 2015 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-26574923

RESUMO

Electrodeposited manganese oxide films (MnOx) are promising stable oxygen evolution catalysts. They are able to catalyze the oxygen evolution reaction in acidic solutions but with only modest activity when prepared by constant anodic potential deposition. We now show that the performance of these catalysts is improved when they are "activated" by potential cycling protocols, as measured by Tafel analysis (where lower slope is better): upon activation the Tafel slope decreases from ∼120 to ∼70 mV/decade in neutral conditions and from ∼650 to ∼90 mV/decade in acidic solutions. Electrochemical, spectroscopic, and structural methods were employed to study the activation process and support a mechanism where the original birnessite-like MnOx (δ-MnO2) undergoes a phase change, induced by comproportionation with cathodically generated Mn(OH)2, to a hausmannite-like intermediate (α-Mn3O4). Subsequent anodic conditioning from voltage cycling or water oxidation produces a disordered birnessite-like phase, which is highly active for oxygen evolution. At pH 2.5, the current density of activated MnOx (at an overpotential of 600 mV) is 2 orders of magnitude higher than that of the original MnOx and begins to approach that of Ru and Ir oxides in acid.

20.
J Am Chem Soc ; 137(37): 11860-3, 2015 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-26305909

RESUMO

The presentation of two phenols on a xanthene backbone is akin to the tyrosine dyad (Y730 and Y731) of ribonucleotide reductase. X-ray crystallography reveals that the two phenol moieties are cofacially disposed at 4.35 Å. Cyclic voltammetry reveals that phenol oxidation is modulated within the dyad, which exhibits a splitting of one-electron waves with the second oxidation of the phenol dyad occurring at larger positive potential than that of a typical phenol. In contrast, a single phenol appended to a xanthene exhibits a two-electron process, consistent with reported oxidation pathways of phenols in acetonitrile. The perturbation of the phenol potential by stacking is reminiscent of a similar effect for guanines stacked within DNA base pairs.


Assuntos
Fenol/química , Xantenos/química , Transporte de Elétrons , Modelos Moleculares , Conformação Molecular , Ribonucleotídeo Redutases/química , Tirosina/química
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