Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 202
Filtrar
1.
Org Biomol Chem ; 22(15): 2978-2984, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38415501

RESUMO

Thienothiophene (TT) has received great attention in the fields of electronics and optoelectronics. Here we report a synthesis and characterization of fullerene-donor-fullerene triads linked to thieno[2,3-b]thiophene as a donor. The photophysical and electrochemical properties of the new dumbbells were investigated using UV-vis spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and square wave voltammetry. The results showed that both compounds have higher LUMO energy levels than PC61BM, indicating that they can be used in photovoltaic applications. Furthermore, the powder was structurally and morphologically characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM). The SEM revealed the morphological characterization of the two derivatives as globular and urchin-like supramolecular assemblies.

2.
Dalton Trans ; 53(9): 3930-3948, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38240369

RESUMO

The remarkable structures of open-cage fullerenes with functionalization on the outer surface and an accessible inner void make them interesting ligands for reactions with metal complexes. The behaviors of open-cage fullerenes in reactions with various metal complexes are examined and compared to the corresponding reactions with intact fullerenes. The structural results from X-ray diffraction are emphasized. Open-cage fullerenes frequently undergo unanticipated structural changes such as carbon-carbon bond cleavage upon reactions with metal complexes. Much more remains to be learned about the possibility of inserting metal ions larger than Li+ into the interior void of these open-cage fullerenes and about the effects of redox reactions on metal complexes of open-cage fullerenes.

3.
Inorg Chem ; 62(39): 15902-15911, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37721543

RESUMO

Six salts ([Au2(µ-dppe)2](BF4)2·CHCl3, [Au2(µ-dppe)2](BF4)2·1,2-Cl2C2H4, [Au2(µ-dppe)2](PF6)2·CHCl3, [Au2(µ-dppe)2](PF6)2, [Au2(µ-dppe)2](SbF6)2, and [Au2(µ-dppe)2](OTf)2·2CHCl3), (dppe is bis(diphenylphosphine)ethane) containing the dication, [Au2(µ-dppe)2]2+, have been prepared and structurally characterized by single-crystal X-ray crystallography. Unlike the three-coordinate dppe-bridged dimers, Au2X2(µ-dppe)2 (X = Br, I), which show considerable variation in the distance between the gold(I) ions over the range 3.0995(10) to 3.8479(3) Å in various solvates, the structure of the helical dication, [Au2(µ-dppe)2], in the new salts is remarkably consistent with the Au···Au separation falling in the narrow range 2.8787(9) to 2.9593(5) Å. In the solid state, the six crystals display a green luminescence both at room temperature and at 77 K, which has been assigned as phosphorescence. However, solutions of the dication are not luminescent. Salts containing the analogous dication [Au2(µ-dppp)2](PF6)2 (dppp is bis(diphenylphosphine)propane) have been prepared to determine whether the longer bridging ligand might also twist into a helical shape. These salts include [Au2(µ-dppp)2](OTf)2 (OTf is triflate) and three crystalline forms of [Au2(µ-dppp)2](PF6)2: the solvate [Au2(µ-dppp)2](PF6)2·(CHCl3) and two polymorphs of the unsolvated salt. None of these crystals are luminescent, but all contain a similar dication, [Au2(µ-dppp)2]2+, that contains two nearly parallel, linear P-Au-P groups and a long separation between the gold ions that varies from 5.3409(4) to 5.6613(6)Å.

5.
Inorg Chem ; 62(34): 14055-14063, 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37582091

RESUMO

The oxidation of thianthrene and 10-phenylphenothiazine into cation radicals has been examined using redox-active Lewis acids. The reaction of titanium(IV) tetrachloride with thianthrene in toluene produces a solution with an EPR spectrum indicative of oxidation of thianthrene to a cation radical, but the molecular compound (1) (µ-thianthrene)Ti2(µ-Cl2)Cl6 crystallized exclusively. Red crystalline (2) (µ-thianthrene)Ti2(µ-Br2)Br6 formed similarly from titanium(IV) tetrabromide. In contrast, the reaction of antimony(V) pentachloride with thianthrene in toluene yielded crystalline (3) (thianthrene·+)2(Sb2(µ-Cl)2Cl62-)·(SbCl3), while the same reaction in acetonitrile produced crystals of (4) (thianthrene·+)(SbCl6-). The two paramagnetic salts differ in that in (3), the folded (thianthrene·+) cation radicals self-associate, whereas in (4), the (thianthrene·+) cation radicals are isolated from one another and are planar. The reaction of 10-phenylphenothiazine with titanium(IV) tetrachloride in toluene solution resulted in the formation of crystalline paramagnetic (5) (10-phenylphenothiazine·+)(Ti(µ-Cl)3Cl6-) and the reaction of 10-phenylphenothiazine with tin(IV) tetrachloride produced paramagnetic (6) (10-phenylphenothiazine·+)(SnCl5-).

6.
Inorg Chem ; 62(13): 5114-5122, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-36939159

RESUMO

Terbium has been added to the list of elements that form oxide clusters inside fullerene cages. Tb2O@C2(13333)-C74 has been isolated as a byproduct of the electric arc synthesis of the azafullerene Tb2@C79N. Cocrystallization of Tb2O@C2(13333)-C74 with Ni(OEP) (where OEP is the dianion of octaethylporphyrin) in toluene yielded black needles of Tb2O@C2(13333)-C74·NiII(OEP)·1.5C7H8 that have been examined by single-crystal X-ray diffraction. The resulting structure shows that a nearly linear Tb-O-Tb unit is contained in a C2(13333)-C74, which has two sites where pentagons share an edge to form pentalene units at opposite ends of the fullerene. Unlike the usual situations where metal atoms in fullerenes that do not obey the isolated pentagon rule are situated within the folds of the pentalene units, the Tb atoms in Tb2O@C2(13333)-C74 are positioned to the side of the pentalene units and near-neighboring hexagons. The magnetic properties of Tb2O@C2(13333)-C74 have been examined starting from the experimental geometry, using ab-initio multiconfigurational methods. The computations predict that Tb2O@C2(13333)-C74 will show strong axiality, which would make it a single-molecule magnet with a large magnetic anisotropy barrier.

7.
Inorg Chem ; 62(11): 4467-4475, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36897254

RESUMO

Synthetic routes to the crystallization of two new box-like complexes, [Au6(Triphos)4(CuBr2)](OTf)5·(CH2Cl2)3·(CH3OH)3·(H2O)4 (1) and [Au6(Triphos)4 (CuCl2)](PF6)5·(CH2Cl2)4 (2) (triphos = bis(2-diphenylphosphinoethyl)phenylphosphine), have been developed. The two centrosymmetric cationic complexes have been structurally characterized through single-crystal X-ray diffraction and shown to contain a CuX2- (X = Br or Cl) unit suspended between two Au(I) centers without the involvement of bridging ligands. These colorless crystals display green luminescence (λem = 527 nm) for (1) and teal luminescence (λem = 464 nm) for (2). Computational results document the metallophilic interactions that are involved in positioning the Cu(I) center between the two Au(I) ions and in the luminescence.

8.
J Psychosoc Oncol ; 41(5): 630-641, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36519613

RESUMO

PURPOSE: Healthcare discrimination has been associated with health disparities including lower cancer screenings, higher medical mistrust, and strained patient-provider relationships. Our study sought to understand patient-reported discrimination among cancer survivors with limited resources living in the United States. DESIGN AND METHODS: We used cross-sectional survey data distributed by the Patient Advocate Foundation (PAF) in 12/2020 and 07/2021. Respondents reported source and reason of healthcare discrimination. Age, sex, race and ethnicity, annual household income, Rural-Urban Commuting Area (RUCA), Area Deprivation Index (ADI), employment status, cancer type, and number of comorbidities were independent variables of interest. The association between these variables and patient-reported healthcare discrimination was estimated using risk ratios (RRs) and 95% confidence intervals (CIs) from a multivariable modified Poisson regression model with robust standard errors. FINDINGS: A total of 587 cancer survivors were included in our analysis. Most respondents were female (72%) and aged ≥56 (62%); while 33% were Black, Indigenous, or Person of Color. Overall, 23% reported receipt of discrimination, with the majority reporting doctor, nurse, or healthcare provider as the source (58%). Most common reasons for discrimination included disease status (42%), income/ability to pay (36%), and race and ethnicity (17%). In the adjusted model, retired survivors were 62% less likely to report discrimination compared to those employed (RR 0.38; 95% CI 0.23-0.64). Additionally, survivors with ≥3 comorbidities were 86% more likely to report discrimination compared to those survivors with no non-cancer comorbidities (RR 1.86; 95% CI 1.26-2.72). IMPLICATIONS: Cancer survivors with limited resources reported substantial discrimination most often from a healthcare provider and most commonly for disease status and income. Discrimination should be mitigated to provide equitable and high-quality cancer care.


Assuntos
Sobreviventes de Câncer , Neoplasias , Humanos , Feminino , Estados Unidos , Masculino , Estudos Transversais , Confiança , Etnicidade , Neoplasias/terapia , Medidas de Resultados Relatados pelo Paciente
9.
Chem Commun (Camb) ; 58(83): 11673-11676, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36172960

RESUMO

Reaction between RuCl2(PPh3)3 and 1,2-diphenylhydrazine resulted in rearrangement and coordination of ortho-semidine. The product, RuCl2(PPh3)2(κ2-NH2-1,2-C6H4-NHPh), was characterized spectroscopically and the molecular structure was conclusively determined using X-ray crystallography. Computational chemistry was employed to probe the energetics surrounding the rearrangement reaction and product.

11.
Chemistry ; 28(17): e202104631, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35150030

RESUMO

Direct synthesis of diamine radical cations in crystalline form proceeding through oxidation of triphenylamine followed by the formation of a new C-N bond is reported. Although the oxidative coupling of triphenylamine is well studied, diamine products are rarely captured in their radical cation state. The neutral diamine most frequently obtained from this reaction pathway is N,N,N',N'-tetraphenylbenzidine. Herein, the capture of radical cations of diamines in crystalline form in one step starting with neutral triphenylamine was demonstrated, and the formation of two products (the radical cations of N,N,N',N'-tetraphenyl-1,4-benzenediamine or N,N,N',N'-tetraphenylbenzidine) depending on the oxidizing agent used was observed. The radical species are characterized by single-crystal X-Ray diffraction, electron paramagnetic resonance spectroscopy, and optical spectroscopy.

13.
Cancer Med ; 10(24): 8854-8865, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34845860

RESUMO

BACKGROUND: Given the high risk of COVID-19 mortality, patients with cancer may be vulnerable to fear of COVID-19, adverse psychological outcomes, and health care delays. METHODS: This longitudinal study surveyed the pandemic's impact on patients with cancer (N= 1529) receiving Patient Advocate Foundation services during early and later pandemic. Generalized estimating equation with repeated measures was conducted to assess the effect of COVID-19 on psychological distress. Logistic regression with repeated measures was used to assess the effect of COVID-19 on any delays in accessing health care (e.g., specialty care doctors, laboratory, or diagnostic testing, etc.). RESULTS: Among 1199 respondents, 94% considered themselves high risk for COVID-19. Respondents with more fear of COVID-19 had a higher mean psychological distress score (10.21; 95% confidence intervals [CI] 9.38-11.03) compared to respondents with less fear (7.55; 95% CI 6.75-8.36). Additionally, 47% reported delaying care. Respondents with more fear of COVID-19 had higher percentages of delayed care than those with less (56; 95% CI 39%-72% vs. 44%; 95% CI 28%-61%). These relationships persisted throughout the pandemic. For respondents with a COVID-19 diagnosis in their household (n = 116), distress scores were similar despite higher delays in care (58% vs. 27%) than those without COVID-19. CONCLUSIONS: Fear of COVID-19 is linked to psychological distress and delays in care among patients with cancer. Furthermore, those who are personally impacted see exacerbated cancer care delays. Timely psychosocial support and health care coordination are critical to meet increased care needs of patients with cancer during the COVID-19 pandemic.


Assuntos
COVID-19/psicologia , Medo , Neoplasias/psicologia , Angústia Psicológica , Adulto , Idoso , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Pandemias , Estresse Psicológico/epidemiologia , Adulto Jovem
14.
Chem Commun (Camb) ; 57(79): 10218-10221, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34523625

RESUMO

Treatment of an open-cage fullerene, designated as MMK-9, with (Ph3P)4Pt in toluene solution at room temperature allows a (PPh3)2Pt unit to be incorporated into the rim of the cage so that it becomes an integral part of the carbon cage skeleton. The structure of the adduct has been determined by single crystal X-ray diffraction and reveals that the platinum atom has planar PtC2P2 coordination, rather than the usual η2-bonding to an intact C-C double bond of the fullerene.

15.
ACS Omega ; 6(31): 20321-20330, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34395980

RESUMO

The design of covalently linked [60]fullerene dimers has gained increased attention, as the linked electron donors or acceptors are in close proximity to the surface of the C60, providing a valuable approach to novel molecular electronic devices. Herein, new compounds involving C60 dumbbells covalently connected by the π-conjugated system from azobenzene and diaryl ether linkers were synthesized following the bifunctional cycloaddition reactions to C60 using microwave radiation. The structural identity of the fullerene dimers has been determined using spectroscopic techniques including Fourier transform infrared (FT-IR), matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF), and NMR spectroscopy, and the photophysical and the electrochemical properties for the new dumbbells have been examined using UV-vis spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and square wave voltammetry. Both new dimers show electronic interaction with the fullerene cage and higher electron affinity than the pristine C60.

16.
J Gynecol Oncol ; 32(6): e87, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34431257

RESUMO

OBJECTIVE: To evaluate financial toxicity and assess its risk factors among patients with gynecologic cancers. METHODS: This is a cross sectional study that included 2 survey tools, as well as patient demographics, disease characteristics, and treatment regimen. Financial toxicity is measured by validated Comprehensive Score for Financial Toxicity (COST) tool. Participants were also asked to complete a 55-question-survey on attitudes and perspectives surrounding cost of care. Descriptive statistics was used to report patient demographics. Spearman's rank correlation was calculated to assess the relation between financial toxicity and patient/disease related variables. Graphpad Prism Software Version 8.0 was used for analyses. RESULTS: A total of 50 patients with various gynecologic malignancies were enrolled. Median COST score was 20.5 (range, 1-33). Sixty-five percent of the patients reported being in debt due to their cancer care and 4% filed bankruptcy. Correlation analysis showed that COST score was correlated with age (r=-0.3, p=0.028), malignancy type (r=0.3, p=0.039) and income (r=0.3, p=0.047). Ovarian cancer patients had significantly less financial toxicity (median COST score=23) when compared to patients with other gynecologic malignancies (median COST score=17, p=0.043). When scores were dichotomized into low (score ≥22) and high toxicity (score <22), 58% (29/50) of the patients were noted to have high financial toxicity. Enrollment to a clinical trial did not significantly alleviate financial burden. CONCLUSION: Financial toxicity is a significant burden even among highly insured gynecologic oncology patients. Age, malignancy type and income were correlated with high financial burden.


Assuntos
Estresse Financeiro , Neoplasias dos Genitais Femininos , Efeitos Psicossociais da Doença , Estudos Transversais , Feminino , Humanos , Inquéritos e Questionários
17.
Cancer Med ; 10(10): 3288-3298, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33932097

RESUMO

BACKGROUND: Given excellent survival outcomes in breast cancer, there is interest in de-escalating the amount of chemotherapy delivered to patients. This approach may be of even greater importance in the setting of the COVID-19 pandemic. METHODS: This concurrent mixed methods study included (1) interviews with patients and patient advocates and (2) a cross-sectional survey of women with breast cancer served by a charitable nonprofit organization. Questions evaluated interest in de-escalation trial participation, perceived barriers/facilitators to participation, and language describing de-escalation. RESULTS: Sixteen patient advocates and 24 patients were interviewed. Key barriers to de-escalation included fear of recurrence, worry about decision regret, lack of clinical trial interest, and dislike for focus on less treatment. Facilitators included trust in physician recommendation, toxicity avoidance, monitoring for progression, perception of good prognosis, and impact on daily life. Participants reported that the COVID-19 pandemic made them more likely to avoid chemotherapy if possible. Of 91 survey respondents, many (43%) patients would have been unwilling to participation in a de-escalation clinical trial. The most commonly reported barrier to participation was fear of recurrence (85%). Few patients (19%) considered clinical trials themselves as a barrier to de-escalation trial participation. The most popular terminology describing chemotherapy de-escalation was "lowest effective chemotherapy dose" (53%); no patients preferred the term "de-escalation." CONCLUSIONS: Fear of recurrence is a common concern among breast cancer survivors and patient advocates, contributing to resistance to de-escalation clinical trial participation. Additional research is needed to understand how to engage patients in de-escalation trials.


Assuntos
Neoplasias da Mama/tratamento farmacológico , COVID-19/prevenção & controle , SARS-CoV-2/isolamento & purificação , Inquéritos e Questionários , Adulto , Idoso , Ansiedade/psicologia , Neoplasias da Mama/psicologia , COVID-19/epidemiologia , COVID-19/virologia , Estudos Transversais , Medo/psicologia , Feminino , Humanos , Pessoa de Meia-Idade , Pandemias , Pesquisa Qualitativa , SARS-CoV-2/fisiologia
18.
Chem Commun (Camb) ; 57(6): 793-796, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33355566

RESUMO

The discovery of a third, non-luminescent crystalline polymorph of [(C6H11NC)2Au]PF6 is reported. Remarkably, crystals of this polymorph are sensitive to mechanical pressure or to exposure to dichloromethane vapor. In both cases, the conversion produces the yellow, green luminescent polymorph of [(C6H11NC)2Au]PF6 and not the colorless, blue luminescent polymorph.

20.
Cancer ; 127(3): 449-457, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33108023

RESUMO

BACKGROUND: The objective of the current study was to understand treatment preferences and their association with financial toxicity in Patient Advocate Foundation clients with breast cancer. METHODS: This choice-based conjoint analysis used data from a nationwide sample of women with breast cancer who received assistance from the Patient Advocate Foundation. Choice sets created from 13 attributes of 3 levels each elicited patient preferences and trade-offs. Latent class analysis segmented respondents into distinct preference archetypes. The Comprehensive Score for Financial Toxicity (COST) tool captured financial toxicity. Adjusted generalized linear models estimated COST score differences by preference archetype. RESULTS: Of 220 respondents (for a response rate of 10%), the median age was 58 years (interquartile range, 49-66 years); 28% of respondents were Black, indigenous, or people of color; and approximately 60% had household incomes <$40,000. The majority of respondents were diagnosed with early-stage cancer (91%), 38% had recurrent disease, and 61% were receiving treatment. Treatment choice was most affected by preferences related to affordability and impact on activities of daily living. Two distinct treatment preference archetypes emerged. The "cost-prioritizing group" (75% of respondents) was most concerned about affordability, impact on activities of daily living, and burdening care partners. The "functional independence-prioritizing group" (25% of respondents) was most concerned about their ability to work, physical side effects, and interference with life events. COST scores were found to be similar between the archetypes in adjusted models (cost-prioritizing group COST score, 12 [95% confidence interval, 9-14]; and functional independence-prioritizing COST score, 11 [95% confidence interval, 9-13]). CONCLUSIONS: Patients with breast cancer prioritized affordability or maintaining functional independence when making treatment decisions. Because of this variability, preference evaluation during treatment decision making could optimize patients' treatment experiences.


Assuntos
Neoplasias da Mama/terapia , Preferência do Paciente , Atividades Cotidianas , Idoso , Neoplasias da Mama/economia , Efeitos Psicossociais da Doença , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...