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1.
Artigo em Inglês | MEDLINE | ID: mdl-38580808

RESUMO

OBJECTIVE: The COVID-19 pandemic disproportionately affected ethnic minority populations and exacerbated preexisting health disparities. The current study aims to promote vaccine uptake among Mexican-origin youth from immigrant families by examining their time to COVID-19 vaccine uptake and assessing the influence of demographic, cognitive, and social factors on the incidence of COVID-19 vaccination. METHODS: The study conducted Survival Analysis using a Cox proportional hazards model based on a sample of 202 Mexican-origin youth (61.39% female; Mage = 20.41) with data collected from August 2021 to January 2023 in central Texas. RESULTS: The results show a critical time period for vaccine uptake (i.e., in the first six months after the vaccines were publicly available), evidenced by a surge decrease in COVID-19 unvaccination probability. In addition, more positive attitudes toward the COVID-19 vaccine (Hazard ratio/HR = 1.89, 95% Confidence Interval/CI = [1.64, 2.18]), greater motivation (HR = 2.29, 95% CI = [1.85, 2.85]), higher education levels (HR = 1.52, 95% CI = [1.24, 1.86]), and fewer general barriers to COVID-19 vaccine knowledge (HR = 0.75, 95% CI = [0.60, 0.94]) were associated with greater incidences of receiving COVID-19 vaccines at any given time point during the pandemic. CONCLUSION: The findings suggest that COVID-19 vaccine uptake among Mexican-origin youth occurred primarily within the initial months of vaccines being publicly distributed. To encourage vaccination among Mexican-origin youth, sustained COVID-19 vaccine promotion efforts are needed by targeting their motivation and positive attitudes and reducing barriers to vaccine information, particularly for youth with lower education levels.

2.
J Magn Reson Imaging ; 59(2): 613-625, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37199241

RESUMO

BACKGROUND: Radiomics has been applied for assessing lymphovascular invasion (LVI) in patients with breast cancer. However, associations between features from peritumoral regions and the LVI status were not investigated. PURPOSE: To investigate the value of intra- and peritumoral radiomics for assessing LVI, and to develop a nomogram to assist in making treatment decisions. STUDY TYPE: Retrospective. POPULATION: Three hundred and sixteen patients were enrolled from two centers and divided into training (N = 165), internal validation (N = 83), and external validation (N = 68) cohorts. FIELD STRENGTH/SEQUENCE: 1.5 T and 3.0 T/dynamic contrast-enhanced (DCE) and diffusion-weighted imaging (DWI). ASSESSMENT: Radiomics features were extracted and selected based on intra- and peritumoral breast regions in two magnetic resonance imaging (MRI) sequences to create the multiparametric MRI combined radiomics signature (RS-DCE plus DWI). The clinical model was built with MRI-axillary lymph nodes (MRI ALN), MRI-reported peritumoral edema (MPE), and apparent diffusion coefficient (ADC). The nomogram was constructed with RS-DCE plus DWI, MRI ALN, MPE, and ADC. STATISTICAL TESTS: Intra- and interclass correlation coefficient analysis, Mann-Whitney U test, and least absolute shrinkage and selection operator regression were used for feature selection. Receiver operating characteristic and decision curve analyses were applied to compare performance of the RS-DCE plus DWI, clinical model, and nomogram. RESULTS: A total of 10 features were found to be associated with LVI, 3 from intra- and 7 from peritumoral areas. The nomogram showed good performance in the training (AUCs, nomogram vs. clinical model vs. RS-DCE plus DWI, 0.884 vs. 0.695 vs. 0.870), internal validation (AUCs, nomogram vs. clinical model vs. RS-DCE plus DWI, 0.813 vs. 0.695 vs. 0.794), and external validation (AUCs, nomogram vs. clinical model vs. RS-DCE plus DWI, 0.862 vs. 0.601 vs. 0.849) cohorts. DATA CONCLUSION: The constructed preoperative nomogram might effectively assess LVI. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/diagnóstico por imagem , Radiômica , Estudos Retrospectivos , Imagem de Difusão por Ressonância Magnética , Mama , Imageamento por Ressonância Magnética
3.
Artigo em Inglês | MEDLINE | ID: mdl-37340123

RESUMO

The current study investigated adolescents' experiences of COVID-19 anti-Chinese discrimination (i.e., vicariously witnessed, directly experienced), the consequences for mental health, and the moderating role of general pandemic stress. During Summer 2020, 106 adolescents (43% Latino/a/x, 19% Asian American, 13% Black/African American, 26% biracial/multiracial/other; 58% female) participated in a 14-day daily diary study. Path analyses revealed that more experiences of vicarious COVID-19 anti-Chinese discrimination were associated with greater anxious mood, depressed mood, and mental health stress, while direct COVID-19 anti-Chinese discrimination was unrelated to mental health outcomes. The interaction between vicarious COVID-19 anti-Chinese discrimination and general COVID-19 stress was significant for depressed mood; simple slope analyses showed that for adolescents reporting high levels of COVID-19 stress, more frequent experiences of vicarious COVID-19 anti-Chinese discrimination were associated with greater severity in depressed mood, but this link was nonsignificant for those reporting low levels of general pandemic stress. Findings from the current study underscore the pernicious effects of vicarious COVID-19 anti-Chinese discrimination on the mental health of minoritized youth beyond solely Asian Americans. Additionally, the results evince the need for future pandemic-response efforts to craft public health messaging that avoids the racialization of disease and subsequent stigmatization of ethnic-minority communities.

4.
J Magn Reson Imaging ; 58(6): 1815-1823, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36988474

RESUMO

BACKGROUND: There are known cardiac manifestations of HIV, but the findings in asymptomatic subjects are still not fully explored. PURPOSE: To evaluate for the presence of subclinical myocardial injury in asymptomatic people living with human immunodeficiency virus (PLWH) by cardiac MRI and to explore the possible association between subclinical myocardial injury and HIV-related clinical characteristics. STUDY TYPE: Cross-sectional. POPULATION: A total of 80 asymptomatic PLWH (age: 53 years [47-56 years]; 90% male) and 50 age- and sex-matched healthy participants. FIELD STRENGTH/SEQUENCE: A 3-T, cine sequence, T1, T2, and T2* mapping. ASSESSMENT: Function analysis was derived from short axis, two-, three-, and four-chamber cine images by feature tracking. Regions of interest were manually selected in the midventricular septum T1, T2, and T2* mapping sequences. PLWH were evaluated for T1 increment (△T1 mapping = native T1 - cutoff values) and HIV-related clinical characteristics, particularly the nadir CD4 count. And PLWH were stratified into two groups according to the cutoff value of native T1: elevated native T1 and normal. STATISTICAL TESTS: T test, Wilcoxon rank-sum test, Chi-square test, Spearman rank correlation, and logistic regression. P <0.05 indicated statistical significance. RESULTS: Asymptomatic PLWH revealed significantly higher native myocardial T1 values (1241 ± 29 msec vs. 1189 ± 21 msec), T2 values (40.7 ± 1.5 msec vs. 37.9 ± 1.4 msec), and lower LVGRS (30.2% ± 6.2% vs. 35.8% ± 6.4%), LVGCS (-18.0% ± 2.5% vs. -19.5% ± 2.0%), and LVGLS (-16.0% ± 3.8% vs. -17.9% ± 2.6%) but showed no difference in T2* values (17.3 msec [16.3-19.1 msec] vs. 18.3 msec [16.5-19.3 msec], P = 0.201). A negative correlation between the native T1 increment in PLWH with subclinical myocardial injury and the nadir CD4 count (u = -0.316). Nadir CD4 count <500 cells/mm3 was associated with higher odds of elevated native T1 myocardial values (odds ratio, 6.12 [95% CI, 1.07-34.91]) in PLWH. DATA CONCLUSION: Subclinical myocardial inflammation and dysfunction were present in asymptomatic PLWH, and a lower nadir CD4 count may be a risk factor for subclinical myocardial injury. EVIDENCE LEVEL: 1. TECHNICAL EFFICACY: Stage 2.


Assuntos
Infecções por HIV , Traumatismos Cardíacos , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , HIV , Estudos Transversais , Imageamento por Ressonância Magnética/métodos , Coração/diagnóstico por imagem , Miocárdio , Infecções por HIV/complicações , Imagem Cinética por Ressonância Magnética , Valor Preditivo dos Testes
5.
Res Int Bus Finance ; 59: 101510, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34539027

RESUMO

In this paper, we investigate both constant and time-varying hedge ratios in terms of the effectiveness of CSI300 index futures during the COVID-19 crisis. Using naïve, OLS and EC/ROLS strategies to estimate constant hedge ratios, results indicate that the CSI300 spot index presents decreased effectiveness using the naïve hedging strategy; however, increased effectiveness of OLS and EC hedge ratios are identified. Differential behaviour is identified when considering five newly introduced COVID-19 concept-based stock indices. Time-varying hedge ratios indicate the weakened effectiveness, ranging between 20% and 40% variance reduction. Evidence suggests that the capability of the CSI300 index futures to hedge against the risks of the COVID-19 is impaired, regardless of whether constant or time-varying hedge ratios are used. Such results provide important implications to both local and foreign investors in the Chinese stock market.

6.
Quant Imaging Med Surg ; 11(6): 2622-2633, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34079728

RESUMO

BACKGROUND: Lymph node (LN) metastasis is an important factor affecting the treatment of lung cancer. The purpose of this article was to investigate the benefits of dual-layer spectral detector computed tomography (SDCT) for the evaluation of metastatic LNs in lung cancer. METHODS: Data from 93 patients with lung cancer who underwent dual-phase enhanced scanning with SDCT were retrospectively analyzed. According to the pathological findings, 166 LNs were grouped as metastatic (n=80) or non-metastatic (n=86). LNs in station 4 (n=80) and station 7 (n=35) accounted for the majority of the LNs (approximately 69.23%). The short-axis diameter of the LN, arterial enhancement fraction (AEF), normalized iodine concentration (NIC), and the slope of the spectral Hounsfield unit curve (λHU) during the arterial phase (AP) and venous phase (VP) were measured. The Mann-Whitney U test was used to statistically compare these quantitative parameters. Receiver operating characteristic (ROC) curves were plotted to identify the cutoff values, and decision curve analysis (DCA) was performed to determine the net benefit of each parameter. The diagnostic performance, obtained by combining the short-axis diameter with each of the above parameters, was also studied. RESULTS: The short-axis LN diameter, AEF, NIC, and λHU during the AP and VP all showed significant differences between the metastatic and non-metastatic groups (P<0.05). Of the parameters, the AEF had the greatest diagnostic efficiency for metastatic LNs [area under the ROC curve (AUC)AEF =0.885] with a threshold of 86.40%. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and 95% confidence interval were 90.00%, 89.53%, 88.89%, 90.59%, and 0.830-0.944, respectively. When the quantitative parameters were combined with the short-axis diameter, the AUCs of the parameters, except the AEF, were significantly improved (P<0.05). CONCLUSIONS: The iodine quantitative parameters from SDCT, such as the AEF, demonstrated high diagnostic performances in the differentiation of metastatic and non-metastatic LNs.

7.
Jpn J Radiol ; 38(4): 374-381, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31989387

RESUMO

BACKGROUND: The purpose of this study is to investigate the performance of dual-layer detector spectral CT for iron deposition compared to magnetic resonance imaging (MRI) T2* imaging. METHODS: Thirty-one patients with a clinical history of myelodysplastic syndromes and aplastic anemia underwent liver and cardiac T2*-weighted unenhanced MRI on a three-tesla MRI scanner, and underwent unenhanced CT scan laterally on a 128-row spectral detector CT. R2* values of the liver, septal muscle, and paraspinal muscle were calculated. Attenuation differences (ΔH) in the liver and myocardium were calculated between the lower (50 keV) and higher (120 keV) energy levels. RESULTS: The liver and cardiac T2* values were 9.54 ± 5.63 ms and 21.41 ± 2.44 ms, respectively. The liver-to-muscle and myocardium-to-muscle T2* value ratios were 0.37 ± 0.23 and 0.79 ± 0.19, respectively. The liver and cardiac ΔH were - 1.13 ± 4.24 HU and 2.22 ± 4.41 HU, respectively. There was a strong linear correlation between the liver R2* and ΔH (r = - 0.832, P < 0.001), but weak correlation existed between the cardiac R2* and ΔH (P = 0.041). CONCLUSIONS: Dual-layer detector spectral unenhanced CT seemed to be equally valuable to MRI T2* imaging for evaluating liver iron overload.


Assuntos
Anemia Aplástica/diagnóstico por imagem , Sobrecarga de Ferro/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Síndromes Mielodisplásicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Algoritmos , Feminino , Coração/diagnóstico por imagem , Humanos , Fígado/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
8.
Int Rev Financ Anal ; 72: 101560, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38620666

RESUMO

The circumstances surrounding the outbreak of the COVID-19 pandemic have generated substantial international political strain as governments attempt to mitigate the widespread associated social and economic repercussions. One theory has focused on the potential for Chinese informational asymmetry. Using Chinese financial market data, we attempt to establish the scale and direction of information flows during multiple distinct phases of the development of the pandemic. Two specific results are identified. Firstly, the majority of domestically-traded Chinese stocks present evidence of significant information flows at a far earlier stage than internationally-traded comparatives, suggesting that domestic investors recognised the dangers associated with COVID-19 far in advance of the rest of the world. One potential explanation surrounds the view that the severity of domestically-reported Chinese news was not appropriately recognised by international investors. Secondly, while evidence of safe-haven and flight-to-safety behaviour is evident throughout traditional energy and precious metal markets, cryptocurrencies became informationally-synchronised with Chinese equity markets, indicating their use as an investor safe-haven. This is a particularly concerning outcome for international policy-maker and regulatory authorities due to the fragility of these developing markets.

9.
Int Rev Financ Anal ; 72: 101569, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38620702

RESUMO

Recent papers that have explored spot and futures markets for Bitcoin have concluded that price discovery takes place either in the spot, or the futures market. Here, we consider the robustness of previous price discovery conclusions by investigating causal relationships, cointegration and price discovery between spot and futures markets for Bitcoin, using appropriate daily data and time-varying mechanisms. We apply the time-varying Granger causality test of Shi, Phillips, and Hurn [2018]; time-varying cointegration tests of Park and Hahn [1999], and time-varying information share methodologies, concluding that futures prices Granger cause spot prices and that futures prices dominate the price discovery process.

10.
J Youth Adolesc ; 47(6): 1238-1251, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29470762

RESUMO

Parents' educational aspirations for youth play an important role in shaping youth's own educational aspirations; however, little is known about how and in what context parents may transmit their aspirations to youth effectively. This is of particular interest and import to be examined in Chinese families, given Chinese cultural emphasis on educational achievement and Chinese youth's outstanding academic performance internationally. By integrating several key theories of motivation and parental socialization (i.e., the expectancy-value model of academic achievement, the two-step model of value transmission, the contextual model of parenting, and the self-determination theory), the current study investigated simultaneously the mediating roles of parental involvement in youth's learning and youth's perceptions of parental aspirations, as well as the moderating role of parental warmth in the intergenerational transmission process of educational aspirations in Chinese families. A two-wave longitudinal study spanning about half a year was conducted among 323 Chinese seventh graders (54% female; Mage = 13.25 years) and one of their parents (median educational attainment = completion of high school, median monthly income = USD 766-1226). It was found that parental educational aspirations for youth were related positively both indirectly through parental involvement and directly to youth's perceptions of parental aspirations, which in turn were associated positively with youth's own educational aspirations about half a year later. It was also found that parental educational aspirations for youth and youth's own educational aspirations were associated positively with each other only when youth reported experiencing high levels of parental warmth, but unrelated when youth reported experiencing low levels of parental warmth, whereas such moderating effects of parental warmth were absent on the links from parental aspirations to youth's perceptions of parental aspirations and parental involvement. These findings highlight the importance of integrating multiple theories to understand parent-to-youth transmission of educational aspirations in non-western cultures, which helps not only reveal generalizability, as well as boundary conditions for Western-originated theories, but also inform practical endeavors at promoting youth's educational achievement worldwide to draw on strengths of different cultures.


Assuntos
Sucesso Acadêmico , Aspirações Psicológicas , Relação entre Gerações/etnologia , Relações Pais-Filho/etnologia , Poder Familiar/psicologia , Adolescente , Povo Asiático , Escolaridade , Feminino , Humanos , Estudos Longitudinais , Masculino , Motivação , Pais/psicologia , Instituições Acadêmicas , Socialização , Estudantes/psicologia
11.
Int Orthop ; 40(6): 1143-55, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26169838

RESUMO

OBJECTIVE: Our aim was to investigate the biological effects of bone morphogenic protein 2 (BMP2) on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into chondrocyte-like cells in platelet-rich plasma (PRP) gel in vitro. In addition, the effectiveness of BMP2-transduced BMSCs in combined with PRP gel to repair the degenerated intervertebral disc in a rabbit model was also evaluated. Previous studies have shown that tissue engineering provides many promising advantages to treating disc degeneration and may reverse the pathological process of disc degeneration. METHODS: The expressions of types I, II and X collagen, aggrecan and Sox9 of the BMP2-transduced BMSCs in monolayer or PRP gel were examined by reverse transcriptase polymerase chain reaction (RT-PCR). Sixty New Zealand white rabbits were divided into five groups: 12 normal controls; 12 puncture operated with only disc degeneration being induced; 12 PRP transplantation animals; 12 BMSC and PRP-transplantation animals; 12 BMP2-transduced BMSCs and PRP-transplantation animals. The effect of BMP2-transduced BMSCs on degenerated discs were evaluated by magnetic resonance image (MRI) scan, histology, immunohistochemistry and Western blot analysis. RESULTS: BMP2 could facilitate chondrogenic differentiation of BMSCs in monolayer or PRP gel. The discs treated with BMP2-transduced BMSCs exhibited relatively well-preserved nucleus pulposus (NP) structure. Significantly higher T2-weighted signal intensity and a greater amount of extracellular matrix were observed in the BMP2-transduced BMSC group compared with other groups. In addition, the presences of BMP2-transduced BMSCs were identified at week 12 postoperatively in vivo. CONCLUSIONS: BMP2-transduced BMSCs can maintain the chondrocyte-like phenotype in PRP gel in vitro, and the combined use of these two agents can significantly promote repair of the degenerated discs in vivo.


Assuntos
Proteína Morfogenética Óssea 2/farmacologia , Degeneração do Disco Intervertebral/terapia , Células-Tronco Mesenquimais/efeitos dos fármacos , Plasma Rico em Plaquetas/efeitos dos fármacos , Agrecanas/metabolismo , Animais , Western Blotting , Diferenciação Celular , Condrócitos/metabolismo , Colágeno/metabolismo , Imuno-Histoquímica , Disco Intervertebral/efeitos dos fármacos , Disco Intervertebral/patologia , Imageamento por Ressonância Magnética , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Plasma Rico em Plaquetas/metabolismo , Coelhos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOX9/metabolismo
12.
J Youth Adolesc ; 44(6): 1263-74, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24820295

RESUMO

Acculturation plays a critical role in the adjustment of Asian Americans, as a large proportion of them are immigrants in the US. However, little is known about how acculturation influences Asian American adolescents' academic trajectories over time. Using a longitudinal sample of 444 Chinese American families (54% female children), the current study explored the effect of mothers', fathers', and adolescents' individual acculturation profiles and parent-child acculturation dissonance on adolescents' academic trajectories from 8th to 12th grade. Academic performance was measured by grade point average (GPA), and by standardized test scores in English language arts (ELA) and Math every year. Latent growth modeling analyses showed that adolescents with a Chinese-oriented father showed faster decline in GPA, and Chinese-oriented adolescents had lower initial ELA scores. Adolescents whose parents had American-oriented acculturation profiles tended to have lower initial Math scores. These results suggest that Chinese and American profiles may be disadvantageous for certain aspects of academic performance, and bicultural adolescents and/or adolescents with bicultural parents are best positioned to achieve across multiple domains. In terms of the role of parent-child acculturation dissonance on academic trajectories, the current study highlighted the importance of distinguishing among different types of dissonance. Adolescents who were more Chinese-oriented than their parents tended to have the lowest initial ELA scores, and adolescents experiencing more normative acculturation dissonance (i.e., who were more American-oriented than their parents) had the highest initial ELA scores. No effects of parent-child acculturation dissonance were observed for GPAs or standardized Math scores. Altogether, the current findings add nuances to the current understanding of acculturation and adolescent adjustment.


Assuntos
Aculturação , Comportamento do Adolescente/etnologia , Povo Asiático/psicologia , Relações Pais-Filho/etnologia , Adaptação Psicológica , Adolescente , Povo Asiático/estatística & dados numéricos , Aspirações Psicológicas , Escolaridade , Feminino , Humanos , Masculino , Poder Familiar , Psicologia do Adolescente , Estados Unidos
14.
Pediatr Radiol ; 39(11): 1209-15, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19669746

RESUMO

BACKGROUND: Transthoracic two-dimensional echocardiography is an effective method for detecting coronary arterial injury in Kawasaki disease. However, its accuracy in the diagnosis of coronary arterial lesions is limited. OBJECTIVE: To investigate the value of multislice spiral CT for coronary angiography for observing the coronary arterial injury caused by infantile Kawasaki disease. MATERIALS AND METHODS: Coronary angiography, using a 64-slice spiral CT scanner, and 2-D echocardiography were performed in 48 children with Kawasaki disease in whom the position, internal diameter, and length of each coronary artery were measured. RESULTS: MSCT showed coronary artery injury in 15 of the 48 children. Among these 15 children, 20 coronary artery branches showed complications, including the left coronary artery branches in 15 (31.2%) and the right coronary artery branches in 5 (10.4%). Complications in the left coronary artery branches included dilation in 12 (25.0%) and stenosis, calcification and the combination of the two in one each, and the right coronary artery branches showed dilation; two branches also showed beaded changes. MSCT also showed dilation in the left anterior descending arteries in two children. These children showed no abnormality on 2-D echocardiography. CONCLUSION: MSCT is a valuable examination method for detecting coronary artery injury in Kawasaki disease.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico por imagem , Ecocardiografia/métodos , Síndrome de Linfonodos Mucocutâneos/complicações , Síndrome de Linfonodos Mucocutâneos/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino
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