Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Am Chem Soc ; 146(28): 19077-19087, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38973199

RESUMO

Deposition of amyloid plaques in the brains of Alzheimer's disease (AD) patients is a hallmark of the disease. AD plaques consist primarily of the beta-amyloid (Aß) peptide but can contain other factors such as lipids, proteoglycans, and chaperones. So far, it is unclear how the cellular environment modulates fibril polymorphism and how differences in fibril structure affect cell viability. The small heat-shock protein (sHSP) alpha-B-Crystallin (αBC) is abundant in brains of AD patients, and colocalizes with Aß amyloid plaques. Using solid-state NMR spectroscopy, we show that the Aß40 fibril seed structure is not replicated in the presence of the sHSP. αBC prevents the generation of a compact fibril structure and leads to the formation of a new polymorph with a dynamic N-terminus. We find that the N-terminal fuzzy coat and the stability of the C-terminal residues in the Aß40 fibril core affect the chemical and thermodynamic stability of the fibrils and influence their seeding capacity. We believe that our results yield a better understanding of how sHSP, such as αBC, that are part of the cellular environment, can affect fibril structures related to cell degeneration in amyloid diseases.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Cadeia B de alfa-Cristalina , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Humanos , Cadeia B de alfa-Cristalina/química , Cadeia B de alfa-Cristalina/metabolismo , Cadeia B de alfa-Cristalina/genética , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/genética , Amiloide/química , Amiloide/metabolismo
2.
PLoS One ; 19(7): e0308159, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39078836

RESUMO

Health communicators are faced with the challenge that people can hesitate vaccines for different reasons. Our aim was to identify and describe the qualities of distinct COVID-19 and influenza vaccine-hesitancy subgroups to facilitate the development of tailored vaccine-hesitancy communication. In two studies, we used agglomerative hierarchical cluster analysis to identify COVID-19 (N = 554) and influenza (N = 539) vaccine-hesitancy subgroups in the general population based on nine vaccine hesitancy-related variables (intent to get vaccinated, perceived vaccine safety, perceived vaccine efficacy, perceived disease threat, perceived vaccination responsibility, perceived vaccination convenience, distrust in authorities, conspiracy mentality, and reliance on anecdotal testimonies). We identified and described six distinct COVID-19 vaccine-hesitancy subgroups (the Vaccination Positive, the Ambivalent, the Fearing Skeptic, the Unconvinced, the Constrained Skeptic, and the Vaccination Opponent), and three influenza vaccine-hesitancy subgroups (the Vaccination Positive, the Complacent, and the Vaccination Opponent), with different levels of hesitancy. We discuss the implications of the results for health communicators. Our results shed light on the (dis)similarities between people who hesitate COVID-19 and influenza vaccines and suggest that there is greater variety in hesitancy concerning COVID-19 vaccinations than influenza vaccinations. These findings can be used to design and test tailored vaccination messages.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Vacinas contra Influenza , Influenza Humana , Hesitação Vacinal , Humanos , Vacinas contra Influenza/administração & dosagem , COVID-19/prevenção & controle , COVID-19/epidemiologia , COVID-19/psicologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Vacinas contra COVID-19/administração & dosagem , Influenza Humana/prevenção & controle , Influenza Humana/epidemiologia , Hesitação Vacinal/psicologia , SARS-CoV-2/imunologia , Idoso , Vacinação/psicologia , Adulto Jovem , Adolescente , Inquéritos e Questionários
3.
Nat Hum Behav ; 8(6): 1044-1052, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38740990

RESUMO

The spread of misinformation through media and social networks threatens many aspects of society, including public health and the state of democracies. One approach to mitigating the effect of misinformation focuses on individual-level interventions, equipping policymakers and the public with essential tools to curb the spread and influence of falsehoods. Here we introduce a toolbox of individual-level interventions for reducing harm from online misinformation. Comprising an up-to-date account of interventions featured in 81 scientific papers from across the globe, the toolbox provides both a conceptual overview of nine main types of interventions, including their target, scope and examples, and a summary of the empirical evidence supporting the interventions, including the methods and experimental paradigms used to test them. The nine types of interventions covered are accuracy prompts, debunking and rebuttals, friction, inoculation, lateral reading and verification strategies, media-literacy tips, social norms, source-credibility labels, and warning and fact-checking labels.


Assuntos
Comunicação , Humanos , Mídias Sociais , Enganação , Normas Sociais
4.
Chemistry ; 30(42): e202401382, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-38805349

RESUMO

Germanium is a promising basis for nanomaterials due to its low toxicity and valuable optical and electronic properties. However, germanium nanomaterials have seen little research compared to other group 14 elements due to unpredictable chemical behavior and high costs. Here, we report the dehydrocoupling of o-tolylgermanium trihydride to amorphous nanoparticles. The reaction is facilitated through reflux at 162 °C and can be accelerated with an amine base catalyst. Through cleavage of both H2 and toluene, new Ge-Ge bonds form. This results in nanoparticles consisting of crosslinked germanium with o-tolyl termination. The particles are 2-6 nm in size and have masses above approximately 3500 Da. The organic substituents are promising for further functionalization. Combined with strong absorption up to 600 nm and moderate solubility and air stability, there are numerous possibilities for future applications.

5.
Health Commun ; : 1-9, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38450609

RESUMO

Research has found that vaccine-promoting messages can elicit state reactance (i.e., negative emotions in response to a perceived threat to behavioral freedom), especially among individuals with high trait reactance (i.e., proneness to experiencing reactance). This can result in a lower willingness to accept vaccines. We investigated whether inoculation against reactance - that is, forewarning individuals about potentially experiencing reactance - can reduce the effects of trait reactance on vaccination willingness. Participants (N = 710) recruited through Facebook were randomly allocated to be either inoculated or not. They were then shown a message promoting a fictitious vaccine, which included either a low, medium, or high threat to freedom. Contrary to research on other health topics, inoculation was ineffective at reducing state reactance toward the vaccination message. Inoculation also did not mitigate the effects of trait reactance on vaccination willingness, and was even counterproductive in some cases. High-reactant individuals were less willing to get vaccinated than low-reactant ones, especially at high freedom threat. Conversely, high freedom threat resulted in increased vaccination willingness among low-reactant individuals. Further research is needed to understand why inoculation against reactance produces different results with vaccination, and to develop communication strategies that mitigate reactance to vaccination campaigns without compromising the positive effects of vaccine recommendations for low-reactant individuals.

6.
Health Psychol ; 43(6): 426-437, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38436659

RESUMO

OBJECTIVE: We introduce and report early stage testing of a novel, multicomponent intervention that can be used by healthcare professionals (HCPs) to address false or misleading antivaccination arguments while maintaining empathy for and understanding of people's motivations to believe misinformation: the "Empathetic Refutational Interview" (ERI). METHOD: We conducted four experiments in 2022 with participants who were predominantly negative or on the fence about vaccination (total n = 2,545) to test four steps for tailoring an HCP's response to a vaccine-hesitant individual: (a) elicit their concerns, (b) affirm their values and beliefs to the extent possible, (c) refute the misinformed beliefs in their reasoning in a way that is tailored to their psychological motivations, and (d) provide factual information about vaccines. Each of the steps was tested against active control conditions, with participants randomized to conditions. RESULTS: Overall, compared to controls, we found that observing steps of the ERI produced small effects on increasing vaccine acceptance and lowering support for antivaccination arguments. Critically, an HCP who affirmed participants' concerns generated significantly more support for their refutations and subsequent information, with large effects compared to controls. In addition, participants found tailored refutations (compared to control responses) more compelling, and displayed more trust and openness toward the HCP giving them. CONCLUSIONS: The ERI can potentially be leveraged and tested further as a tailored communication tool for HCPs to refute antivaccination misconceptions while maintaining trust and rapport with patients. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Assuntos
Empatia , Humanos , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Hesitação Vacinal/psicologia , Adulto Jovem , Vacinação/psicologia , Pessoal de Saúde/psicologia , Comunicação , Motivação , Adolescente , Entrevistas como Assunto
7.
Molecules ; 29(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38338409

RESUMO

Two fundamental halocarbon ions, CH2Cl+ and CH3ClH+, were studied in the gas phase using the FELion 22-pole ion trap apparatus and the Free Electron Laser for Infrared eXperiments (FELIX) at Radboud University, Nijmegen (the Netherlands). The vibrational bands of a total of four isotopologs, CH235,37Cl+ and CH335,37ClH+, were observed in selected wavenumber regions between 500 and 2900 cm-1 and then spectroscopically assigned based on the results of anharmonic force field calculations performed at the CCSD(T) level of theory. As the infrared photodissociation spectroscopy scheme employed probes singly Ne-tagged weakly bound complexes, complementary quantum-chemical calculations of selected species were also performed. The impact of tagging on the vibrational spectra of CH2Cl+ and CH3ClH+ is found to be virtually negligible for most bands; for CH3ClH+-Ne, the observations suggest a proton-bound structural arrangement. The experimental band positions as well as the best estimate rotational molecular parameters given in this work provide a solid basis for future spectroscopic studies at high spectral resolutions.

8.
J Chem Phys ; 160(7)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38364002

RESUMO

The rotational spectrum of the molecular ion HCNH+ is revisited using double-resonance spectroscopy in an ion trap apparatus, with six transitions measured between 74 and 445 GHz. Due to the cryogenic temperature of the trap, the hyperfine splittings caused by the 14N quadrupolar nucleus were resolved for transitions up to J = 4 ← 3, allowing for a refinement of the spectroscopic parameters previously reported, especially the quadrupole coupling constant eQq.

9.
J Am Chem Soc ; 146(2): 1501-1511, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38189235

RESUMO

The self-assembly of organic amphiphilic species into various aggregates such as spherical or elongated micelles and cylinders up to the formation of lyotropic hexagonal or lamellar phases results from cooperative processes orchestrated by the hydrophobic effect, while those involving ionic inorganic polynuclear entities and nonionic organic components are still intriguing. Herein, we report on the supramolecular behavior of giant toroidal molybdenum blue-type polyoxometalate, namely, the {Mo154} species in the presence of n-octyl-ß-glucoside (C8G1), widely used as a surfactant in biochemistry. Structural investigations were carried out using a set of complementary multiscale methods including single-crystal X-ray diffraction analysis supported by molecular modeling, small-angle X-ray scattering and cryo-TEM observations. In addition, liquid NMR, viscosimetry, surface tension measurement, and isothermal titration calorimetry provided further information to decipher the complex aggregation pathway. Elucidation of the assembly process reveals a rich scenario where the presence of the large {Mo154} anion disrupts the self-assembly of the C8G1, well-known to produce micelles, and induces striking successive phase transitions from fluid-to-gel and from gel-to-fluid. Herein, intimate organic-inorganic primary interactions arising from the superchaotropic nature of the {Mo154} lead to versatile nanoscopic hybrid C8G1-{Mo154} aggregates including crystalline discrete assemblies, smectic lamellar liquid crystals, and large uni- or multilamellar vesicles where the large torus {Mo154} acts a trans-membrane component.

10.
Sci Commun ; 44(5): 531-558, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38603361

RESUMO

Misinformation about mRNA vaccination is a barrier in the global fight against the COVID-19 pandemic. Thus, authorities often rely on text-based refutations as a countermeasure. In two experiments (N = 2,444), text-based refutations effectively reduced the belief in misinformation and immunized participants against the impact of a misleading social media post. However, a follow-up (N = 817) questions the longevity of these debunking and prebunking effects. Moreover, the studies reveal potential pitfalls by showing a row of unintended effects of the refutations (lacking effect on intentions, backfire-effects among religious groups, and biased judgments when omitting information about vaccine side effects).

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA