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1.
Chem Mater ; 36(11): 5596-5610, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38883437

RESUMEN

Operando synchrotron radiation-based techniques are a precious tool in battery research, as they enable the detection of metastable intermediates and ensure characterization under realistic cycling conditions. However, they do not come exempt of risks. The interaction between synchrotron radiation and samples, particularly within an active electrochemical cell, can induce relevant effects at the irradiated spot, potentially jeopardizing the experiment's reliability and biasing data interpretation. With the aim of contributing to this ongoing debate, a systematic investigation into these phenomena was carried out by conducting a root cause analysis of beam-induced effects during the operando characterization of two of the most commonly employed positive electrode materials in commercial Li-ion batteries: LiNi0.33Mn0.33Co0.33O2 and LiFePO4. The study spans across diverse experimental conditions involving different cell types and absorption and scattering techniques and seeks to correlate beam effects with factors such as radiation energy, photon flux, exposure time, and other parameters associated with radiation dosage. Finally, it provides a comprehensive set of guidelines and recommendations for assessing and mitigating beam-induced effects that may affect the outcome of battery operando experiments.

2.
AIDS Behav ; 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38816592

RESUMEN

This randomized controlled study assessed the feasibility, acceptability, and preliminary impact of the PrEP iT! mHealth intervention designed to improve PrEP adherence among young men who have sex with men (YMSM). A national sample of 80 YMSM in the U.S. (Mage = 25 years; 54% racial/ethnic minority), recruited through social media ads, were randomized to either the PrEP iT! or usual PrEP care conditions. Participants completed online surveys and submitted self-collected dried blood sample (DBS) data as measures of PrEP adherence. Differences in PrEP adherence across treatment arms and between participants with high versus low engagement in PrEP iT! were assessed. Retention was high at the three (94%) and six (93%) month assessment, and participants in PrEP iT! reported satisfactory acceptability of the intervention. There were no significant differences in self-reported or DBS-derived PrEP adherence between randomized groups. However, YMSM in the PrEP iT! group with high PrEP adherence (the equivalent of four or more doses/week through self-report and DBS-derived measures) demonstrated significantly higher engagement in the intervention than those with low PrEP adherence (the equivalent of 3 or fewer doses/week). Overall, the PrEP iT! intervention demonstrated strong feasibility and acceptability. The finding that high PrEP iT! intervention engagement was associated with protective levels of PrEP adherence suggests it is a viable adherence support tool that should be further evaluated in definitive trial among YMSM who need basic support, or as part of a more comprehensive adherence support package for those who need greater assistance.Trial registration Clinical Trials # NCT04509076 (registered August 10, 2020).

3.
J Homosex ; : 1-17, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38377340

RESUMEN

Although the use of geosocial networking (GSN) applications for relationship seeking is prevalent among sexual minority men (SMM), SMM of color may be vulnerable to sexual racism online. Little is known about how sexual racism relates to SMM of color's identity outness, which is integral to the minority stress model and the focus of this study. Eighty SMM, recruited through social media (53.7% racial/ethnic minority), reported their experiences of race-based discrimination on GSN apps and identity outness. Chi-squared and Fisher's tests examined differences in race-based discrimination online by participants' race/ethnicity. A factorial MANOVA was performed on outness to family, peers, and healthcare providers. Nearly one-third of participants experienced race-based discrimination online. Higher percentages of SMM of color experienced race-based discrimination than White SMM. SMM who experienced race-based discrimination online reported lower outness to family than those who had not. Post-hoc analyses revealed that Asian SMM reported consistently lower outness than other groups. Our findings resonated with the mediation framework of minority stress, suggesting that sexual racism online may be a distal stressor that contributes to the group-specific process of identity outness. This also illustrated the importance of addressing sexual racism on GSN apps to buffer existing stress with outness among SMM of color.

4.
J Sex Res ; 61(2): 285-298, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37163732

RESUMEN

Scholars have established connections between how married couples navigate their finances and their sexual relationship. For example, financial management behaviors are associated with sexual satisfaction among newlywed couples. However, we know very little about the direction of the association between financial management behaviors and sexual satisfaction. Understanding which might predict the other, or if there might be a bidirectional association between the two, could provide information on where to intervene to help newlywed couples with financial or sexual obstacles in their marriage. With three waves of dyadic data (N = 1,205 U.S. newlywed couples), we used structural equation modeling to examine the bidirectional, indirect associations between husbands' and wives' financial management behaviors and their own sexual satisfaction through their own marital satisfaction. Overall, we found that financial management behaviors indirectly predicted changes in sexual satisfaction through marital satisfaction for both husbands and wives. We also found limited evidence that husbands' sexual satisfaction indirectly predicted changes in their own financial management behaviors through their own marital satisfaction. Additionally, these indirect associations differed by gender. Partner effects, however, were largely non-significant. Implications of these findings for those who help newlywed couples with their sexual relationships are discussed.


Asunto(s)
Matrimonio , Orgasmo , Humanos , Satisfacción Personal , Conducta Sexual , Identidad de Género , Esposos
5.
Fam Process ; 63(1): 176-191, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37055040

RESUMEN

Guided by an intersectional feminism framework, we used three-wave, dyadic survey data from a nationally representative sample of 1625 U.S. different-gender newlywed couples to test three research questions. First, as balanced power is considered a key concept for relational well-being in feminism, we examined developmental trajectories in husbands' and wives' perception of power (im)balance. Second, considering money as a major influence on power and aggression, we examined how financial behaviors relate to power (im)balance and in turn relational aggression-a type of intimate partner violence that is controlling and manipulative in nature. Third, informed by the intersectionality between gender and socioeconomic status (SES), we examined gender differences and SES disparities in the associations among financial behaviors, developmental trajectories of perception of power (im)balance, and relational aggression. Our findings demonstrate that newlywed different-gender couples are experiencing power struggles, where two partners diminish each other's influence over time. We also found that healthy financial behaviors are associated with balanced power and, in turn, less relational aggression (especially for wives and in lower-SES households). Taken collectively, we continue calling for efforts to facilitate money management skills and promote balanced marital power.


Asunto(s)
Agresión , Violencia de Pareja , Humanos , Matrimonio , Esposos , Composición Familiar
6.
Int J Behav Med ; 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38114707

RESUMEN

BACKGROUND: Pre-exposure prophylaxis (PrEP) and HIV treatment as prevention, which underlies the Undetectable = Untransmittable (U = U) campaign, are two effective biomedical approaches for HIV prevention among sexual minority men (SMM). Attitudes toward PrEP and U = U may differ between SMM emerging adults (EA: 18-24 years old) and young adults (YA: 25-29 years old) to drive differences in sexual behavior. However, to date, few studies assessed the degree to which YAs and EAs differ in their beliefs in the effectiveness of PrEP and U = U. METHOD: A national sample of 80 SMM in the USA (Mage = 25.1 years; 53.7% racial/ethnic minority; 38.8% EA; 61.3% YA) participated in a 6-month mHealth intervention for PrEP adherence. Non-parametric tests assessed differences in sexual behaviors and attitudes toward the effectiveness of PrEP and U = U between EAs and YAs using baseline data. RESULTS: Compared to EAs, higher proportions of YAs trusted PrEP's effectiveness and considered condom use unnecessary after taking PrEP. More YAs than EAs were willing to engage in sexual behaviors that they felt too risky before learning about U = U and were more comfortable having condomless sex with HIV-positive partners. Conversely, a greater proportion of EAs than YAs preferred to use condoms even when their partners are on anti-HIV medications. CONCLUSION: Overall, YAs trusted the effectiveness of U = U and PrEP more than EAs, underscoring developmental differences in SMM's perspectives on biomedical HIV prevention tools. Our findings underscore the importance of tailoring messages on biomedical HIV prevention options differently for EAs and YAs to optimize uptake.

7.
ACS Appl Energy Mater ; 6(13): 7250-7257, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37448980

RESUMEN

Ca- and Mg-based batteries represent a more sustainable alternative to Li-ion batteries. However, multivalent cation technologies suffer from poor cation mass transport. In addition, the development of positive electrodes enabling reversible charge storage currently represents one of the major challenges. Organic positive electrodes, in addition to being the most sustainable and potentially low-cost candidates, compared with their inorganic counterparts, currently present the best electrochemical performances in Ca and Mg cells. Unfortunately, organic positive electrodes suffer from relatively low capacity retention upon cycling, the origin of which is not yet fully understood. Here, 1,4,5,8-naphthalenetetracarboxylic dianhydride-derived polyimide was tested in Li, Na, Mg, and Ca cells for the sake of comparison in terms of redox potential, gravimetric capacities, capacity retention, and rate capability. The redox mechanisms were also investigated by means of operando IR experiments, and a parameter affecting most figures of merit has been identified: the presence of contact ion-pairs in the electrolyte.

9.
AIDS Behav ; 27(11): 3632-3644, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37195471

RESUMEN

Pre-exposure prophylaxis (PrEP) is a highly effective HIV prevention option for gay, bisexual and other men who have sex with men (GBMSM). However, with newer PrEP options, a greater understanding of whether and why GBMSM switch dosing strategies is needed to inform clinical practice and research. We assessed the dosing strategies (daily or on-demand) of GBMSM enrolled in an mHealth PrEP adherence pilot intervention at four timepoints over approximately 10 months. Among GBMSM with complete data (n = 66), a consistent daily dosing strategy was used by most (73%) participants across all time points, while on-demand PrEP was used at least once during the study period by 27% of participants. A higher percentage of on-demand PrEP users self-reported as Asian/Pacific Islander and had less positive attitudes toward PrEP, adjusting for key sociodemographic variables and intervention arm. Daily PrEP users reported high numbers of sexual partners, and the primary reason that they would switch to on-demand PrEP is reduced sexual activity. At the final assessment, 75% of participants were taking daily PrEP, of whom 27% reported that they would like to switch to another option, including on-demand and long-acting injectable PrEP. While findings were largely descriptive, they showed that switches in PrEP dosing strategies are relatively common and PrEP strategy choice may vary across racial and ethnic groups.


Asunto(s)
Infecciones por VIH , Profilaxis Pre-Exposición , Minorías Sexuales y de Género , Masculino , Humanos , Adulto Joven , Homosexualidad Masculina , Infecciones por VIH/prevención & control , Infecciones por VIH/tratamiento farmacológico , Conducta Sexual
10.
Chem Sci ; 14(7): 1641-1665, 2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36819848

RESUMEN

Synchrotron radiation based techniques are powerful tools for battery research and allow probing a wide range of length scales, with different depth sensitivities and spatial/temporal resolutions. Operando experiments enable characterization during functioning of the cell and are thus a precious tool to elucidate the reaction mechanisms taking place. In this perspective, the current state of the art for the most relevant techniques (scattering, spectroscopy, and imaging) is discussed together with the bottlenecks to address, either specific for application in the battery field or more generic. The former includes the improvement of cell designs, multi-modal characterization and development of protocols for automated or at least semi-automated data analysis to quickly process the huge amount of data resulting from operando experiments. Given the recent evolution in these areas, accelerated progress is expected in the years to come, which should in turn foster battery performance improvements.

11.
J Fam Econ Issues ; 44(1): 34-52, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36820278

RESUMEN

Guided by the family adjustment and adaptation response (FAAR) model and using a panel survey of 1510 adults in the US administered during the summer of 2020 and a mixed methods approach, we explored associations between changes in financial stress related to COVID-19 and relational wellbeing. Regression analyses showed that, compared to those who maintained their levels of financial stress, those who reported increased financial stress reported increased conflict and those who reported decreased financial stress reported decreased conflict. However, decreased financial stress was also associated with decreases in emotional closeness and relationship happiness, suggesting that changes in financial stress can lead to both maladaptation and bonadaptation in families. Qualitative findings provide insights into factors that may exacerbate or help alleviate financial stress related to COVID-19.

12.
ACS Appl Energy Mater ; 5(10): 11964-11969, 2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-36311467

RESUMEN

Magnesium batteries have attracted great attention as an alternative to Li-ion batteries but still suffer from limited choice of positive electrode materials. V2O5 exhibits high theoretical capacities, but previous studies have been mostly limited to α-V2O5. Herein, we report on the ß-V2O5 polymorph as a Mg intercalation electrode. The structural changes associated with the Mg2+ (de-) intercalation were analyzed by a combination of several characterization techniques: in situ high resolution X-ray diffraction, scanning transmission electron microscopy, electron energy-loss spectroscopy, and X-ray absorption spectroscopy. The reversible capacity reached 361 mAh g-1, the highest value found at room temperature for V2O5 polymorphs.

13.
Artículo en Inglés | MEDLINE | ID: mdl-36293701

RESUMEN

Many emerging adults have experienced increased financial distress and mental health problems during the COVID-19 pandemic, and isolation may have amplified the importance of close relationships (especially as parents' influence diminishes during this developmental stage). Using the ABC-X Model to frame our model, we tested whether financial distress (C) mediates the associations between COVID-19 impact (A) and anxiety and depressive symptoms (X), and whether or not romantic relationship quality (B) moderates these indirect associations. Our sample comprised of 1950 U.S. emerging adults in a romantic relationship. Mediation and first-stage moderated mediation were tested using structural equation modeling. Financial distress partially mediated the association between COVID-19 impact and anxiety symptoms and fully mediated the association between COVID-19 impact and depressive symptoms. Strong evidence of moderated mediation was found but in the opposite direction expected: the indirect associations of COVID-19 impact with anxiety and depressive symptoms (through financial distress) were stronger for those in high-quality romantic relationships. The findings may inform policy and practice aimed at optimizing the mental health of emerging adults, especially in light of the ongoing COVID-19 pandemic: specifically, alleviating financial distress may improve the mental health of emerging adults, while focusing on the quality of their romantic relationships may not.


Asunto(s)
COVID-19 , Adulto , Humanos , COVID-19/epidemiología , Pandemias , Salud Mental , Depresión/epidemiología , Depresión/psicología , Ansiedad/epidemiología , Ansiedad/psicología
15.
Front Psychol ; 13: 883352, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35992422

RESUMEN

Emerging adult newlywed couples often experience many demands on their time, and three common problems may surface as couples try to balance these demands-problems related to finances, sleep, and sex. We used two waves of dyadic data from 1,001 emerging adult newlywed couples to identify four dyadic latent profiles from husbands' and wives' financial management behaviors, sexual satisfaction, and sleep quality: Flounderers, Financially Challenged Lovers, Drowsy Budgeters, and Flourishers. We then examined how husbands' and wives' marital satisfaction, in relation to profile membership, varied at a later wave. We found that Financially Challenged Lovers and Flourishers had significantly higher marital satisfaction than Drowsy Budgeters and Flounderers (mostly medium effect sizes). Whereas, Financially Challenged Lovers and Flourishers did not differ in terms of marital satisfaction, Drowsy Budgeters seemed to have slightly higher marital satisfaction than Flounderers for wives only (small effect size). However, we did not find evidence that these connections meaningfully differed by sex. Implications for the efforts of clinicians and educators are discussed.

16.
J Fam Psychol ; 36(6): 943-953, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34735182

RESUMEN

A theoretically grounded, validated measure of parent financial socialization is needed. This article describes the development and validation process of three new scales: the Parent Financial Modeling Scale (eight items), the Parent-Child Financial Discussion Scale (nine items), and the Experiential Learning of Finances Scale (three items). These may be treated as subscales of a multidimensional latent construct: the Parent Financial Socialization Scale (20 items). The three scales measure the three primary methods of family financial socialization. The scales are designed to be retrospective, with target participants being U.S. emerging adults (age 18-30). A rigorous development process was undertaken: an initial pool of items was generated, expert assessments were collected, cognitive interviews were conducted, and (following preliminary data collection) preliminary item reduction analysis and confirmatory factor analysis (CFA) were conducted. Final data were collected from a diverse (51.7% female, 47.6% male; 31.6% White, 22.0% Black, 19.8% Latinx, 14.6% Asian; 50.4% no parent with college degree, 47.4% parent with college degree) sample of 4,182 U.S. emerging adults. During validation, item reduction analysis, CFA, reliability tests, measurement invariance tests, and construct validity tests were conducted. The scales demonstrated acceptable reliability and validity, and invariance was established across sex, race, and parents' education level. These scales are unique in their ability to capture nuance and will allow for comparisons across studies. They will enhance the quality of family financial socialization research, expand the questions that can be answered, and allow for the development of programming that is effective for a wide range of families. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Asunto(s)
Padres , Socialización , Adolescente , Adulto , Análisis Factorial , Femenino , Humanos , Masculino , Padres/psicología , Psicometría , Reproducibilidad de los Resultados , Estudios Retrospectivos , Encuestas y Cuestionarios , Adulto Joven
17.
Adv Mater ; 34(8): e2108363, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34881463

RESUMEN

Porous carbon has been widely used as an efficient host to encapsulate highly active molecular sulfur (S) in Li-S and Na-S batteries. However, for these sub-nanosized pores, it is a challenge to provide fully accessible sodium ions with unobstructed channels during cycling, particularly for high sulfur content. It is well recognized that solid interphase with full coverage over the designed architectures plays critical roles in promoting rapid charge transfer and stable conversion reactions in batteries, whereas constructing a high-ionic-conductivity solid interphase in the pores is very difficult. Herein, unique continuous carbonaceous pores are tailored, which can serve as multifunctional channels to encapsulate highly active S and provide fully accessible pathways for sodium ions. Solid sodium sulfide interphase layers are also realized in the channels, showing high Na-ion conductivity toward stabilizing the redox kinetics of the S cathode during charge/discharge processes. This systematically designed carbon-hosted sulfur cathode delivers superior cycling performance (420 mAh g-1 at 2 A g-1 after 2000 cycles), high capacity retention of ≈90% over 500 cycles at current density of 0.5 A g-1 , and outstanding rate capability (470 mAh g-1 at 5 A g-1 ) for room-temperature sodium-sulfur batteries.

18.
Dalton Trans ; 49(8): 2671-2679, 2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32048697

RESUMEN

Sustainability combined with high energy density prospects makes Fe-based oxides attractive as cathodes for calcium rechargeable batteries. This work presents a DFT evaluation of the CaFe2+nO4+n (0 < n < 3) family, for which both the average intercalation voltage and the theoretical specific capacity decrease with the increasing n value. The term n = 1/4, Ca4Fe9O17, meets the most appealing characteristics: a calculated average voltage of 4.16 V, a theoretical specific capacity of 230 mA h g-1 and the lowest energy barrier for Ca migration so far predicted for an existing oxide (0.72 eV). To overcome the previously reported synthesis difficulties, we employed a novel synthesis procedure in sealed quartz tubes followed by quenching in water. The XRD and SAED patterns of the prepared Ca4Fe9O17 powder reveal a certain degree of stacking defects along the c axis. Attempts to deinsert Ca ions from Ca4Fe9O17 by chemical means (NO2BF4 in ACN) and in electrochemical Ca cells were unsuccessful, although some hints of oxidation are observed in Li cells with the LP30 electrolyte. The suitability of Ca4Fe9O17 as a Ca cathode is pending further studies utilizing Ca-electrolytes with high anodic stability.

19.
ACS Omega ; 4(5): 8943-8952, 2019 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-31459982

RESUMEN

Layered CaTaN2 and MgTa2N3 and cubic Mg2Ta2N4 were prepared by direct solid state reaction from the binary nitrides Ta3N5 and A3N2 (A: Mg, Ca). CaTaN2 showed a slight Ca deficiency (0.11 moles per formula), and a monoclinic distortion from previously reported R3̅m symmetry, with space group C2/m and cell parameters a = 5.4011(2), b = 3.1434(1), c = 5.9464(2) Å and ß = 107.91(3)°. Ca2+ and Mg2+ deintercalation was investigated in the three compounds both chemically and electrochemically. No significant Mg2+ extraction could be inferred for MgTa2N3 and Mg2Ta2N4, neither after reaction with NO2BF4 nor after electrochemical oxidation at 100 °C in alkyl carbonate electrolytes. Rietveld refinement of the X-ray powder diffraction pattern of chemically oxidized Ca0.89TaN2 indicates a decrease of the Ca content to 0.34 concomitant to the disappearance of the monoclinic distortion and expansion of the interlayer space from 5.658 to 5.762 Å, space group R3̅m and cell parameters a = 3.1103(1) and c = 17.287(1) Å. Deintercalation in this compound was also achieved electrochemically at 100 °C. Results of density functional theory calculations seem to indicate that reaction mechanisms for CaTaN2 oxidation additional and/or alternative to deintercalation are taking place, which is likely related to the loss of crystallinity observed upon oxidation and the irreversibility of the process.

20.
Chem Commun (Camb) ; 55(21): 3105-3108, 2019 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-30789159

RESUMEN

The topotactic nitridation of cation ordered, tetragonal Sr2FeMoO6 in NH3 at moderate temperatures leads to cubic, Fm3[combining macron]m double perovskite oxynitride Sr2FeMoO4.9N1.1 where double-exchange interactions determine ferromagnetic order with TC ≈ 100 K. Substitution of oxide by nitride induces bond asymmetries and local electronically driven structural distortions, which combined with Fermi level lowering restricts charge itinerancy to confined regions and preclude spontaneous long-range magnetic order. Under a magnetic field, ferromagnetic correlations expand, favoring charge delocalization and a negative magnetoresistance is observed.

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