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1.
J Am Heart Assoc ; 13(9): e033253, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38686864

RESUMO

BACKGROUND: The digital transformation of medical data enables health systems to leverage real-world data from electronic health records to gain actionable insights for improving hypertension care. METHODS AND RESULTS: We performed a serial cross-sectional analysis of outpatients of a large regional health system from 2010 to 2021. Hypertension was defined by systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or recorded treatment with antihypertension medications. We evaluated 4 methods of using blood pressure measurements in the electronic health record to define hypertension. The primary outcomes were age-adjusted prevalence rates and age-adjusted control rates. Hypertension prevalence varied depending on the definition used, ranging from 36.5% to 50.9% initially and increasing over time by ≈5%, regardless of the definition used. Control rates ranged from 61.2% to 71.3% initially, increased during 2018 to 2019, and decreased during 2020 to 2021. The proportion of patients with a hypertension diagnosis ranged from 45.5% to 60.2% initially and improved during the study period. Non-Hispanic Black patients represented 25% of our regional population and consistently had higher prevalence rates, higher mean systolic and diastolic blood pressure, and lower control rates compared with other racial and ethnic groups. CONCLUSIONS: In a large regional health system, we leveraged the electronic health record to provide real-world insights. The findings largely reflected national trends but showed distinctive regional demographics and findings, with prevalence increasing, one-quarter of the patients not controlled, and marked disparities. This approach could be emulated by regional health systems seeking to improve hypertension care.


Assuntos
Registros Eletrônicos de Saúde , Hipertensão , Humanos , Hipertensão/epidemiologia , Hipertensão/tratamento farmacológico , Hipertensão/diagnóstico , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Prevalência , Idoso , Pressão Sanguínea/efeitos dos fármacos , Adulto , Disparidades em Assistência à Saúde/tendências , Fatores de Tempo , Anti-Hipertensivos/uso terapêutico , Disparidades nos Níveis de Saúde , Determinação da Pressão Arterial/métodos
2.
medRxiv ; 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38370787

RESUMO

Background: SGLT2 inhibitors (SGLT2is) and GLP-1 receptor agonists (GLP1-RAs) reduce major adverse cardiovascular events (MACE) in patients with type 2 diabetes mellitus (T2DM). However, their effectiveness relative to each other and other second-line antihyperglycemic agents is unknown, without any major ongoing head-to-head trials. Methods: Across the LEGEND-T2DM network, we included ten federated international data sources, spanning 1992-2021. We identified 1,492,855 patients with T2DM and established cardiovascular disease (CVD) on metformin monotherapy who initiated one of four second-line agents (SGLT2is, GLP1-RAs, dipeptidyl peptidase 4 inhibitor [DPP4is], sulfonylureas [SUs]). We used large-scale propensity score models to conduct an active comparator, target trial emulation for pairwise comparisons. After evaluating empirical equipoise and population generalizability, we fit on-treatment Cox proportional hazard models for 3-point MACE (myocardial infarction, stroke, death) and 4-point MACE (3-point MACE + heart failure hospitalization) risk, and combined hazard ratio (HR) estimates in a random-effects meta-analysis. Findings: Across cohorts, 16·4%, 8·3%, 27·7%, and 47·6% of individuals with T2DM initiated SGLT2is, GLP1-RAs, DPP4is, and SUs, respectively. Over 5·2 million patient-years of follow-up and 489 million patient-days of time at-risk, there were 25,982 3-point MACE and 41,447 4-point MACE events. SGLT2is and GLP1-RAs were associated with a lower risk for 3-point MACE compared with DPP4is (HR 0·89 [95% CI, 0·79-1·00] and 0·83 [0·70-0·98]), and SUs (HR 0·76 [0·65-0·89] and 0·71 [0·59-0·86]). DPP4is were associated with a lower 3-point MACE risk versus SUs (HR 0·87 [0·79-0·95]). The pattern was consistent for 4-point MACE for the comparisons above. There were no significant differences between SGLT2is and GLP1-RAs for 3-point or 4-point MACE (HR 1·06 [0·96-1·17] and 1·05 [0·97-1·13]). Interpretation: In patients with T2DM and established CVD, we found comparable cardiovascular risk reduction with SGLT2is and GLP1-RAs, with both agents more effective than DPP4is, which in turn were more effective than SUs. These findings suggest that the use of GLP1-RAs and SGLT2is should be prioritized as second-line agents in those with established CVD. Funding: National Institutes of Health, United States Department of Veterans Affairs.

3.
Nature ; 626(7999): 523-528, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38356068

RESUMO

Spatial, momentum and energy separation of electronic spins in condensed-matter systems guides the development of new devices in which spin-polarized current is generated and manipulated1-3. Recent attention on a set of previously overlooked symmetry operations in magnetic materials4 leads to the emergence of a new type of spin splitting, enabling giant and momentum-dependent spin polarization of energy bands on selected antiferromagnets5-10. Despite the ever-growing theoretical predictions, the direct spectroscopic proof of such spin splitting is still lacking. Here we provide solid spectroscopic and computational evidence for the existence of such materials. In the noncoplanar antiferromagnet manganese ditelluride (MnTe2), the in-plane components of spin are found to be antisymmetric about the high-symmetry planes of the Brillouin zone, comprising a plaid-like spin texture in the antiferromagnetic (AFM) ground state. Such an unconventional spin pattern, further found to diminish at the high-temperature paramagnetic state, originates from the intrinsic AFM order instead of spin-orbit coupling (SOC). Our finding demonstrates a new type of quadratic spin texture induced by time-reversal breaking, placing AFM spintronics on a firm basis and paving the way for studying exotic quantum phenomena in related materials.

4.
medRxiv ; 2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38260693

RESUMO

IMPORTANCE: Hypertension poses a significant public health challenge. Despite clinical practice guidelines for hypertension management, clinician adherence to these guidelines remains suboptimal. OBJECTIVE: This study aims to develop a taxonomy of suboptimal adherence scenarios for severe hypertension and identify barriers to guideline adherence. DESIGN: We conducted a qualitative content analysis using electronic health records (EHRs) of Yale New Haven Health System who had at least two consecutive visits between January 1, 2013, and October 31, 2018. SETTING: This was a thematic analysis of EHR data to generate a real-world taxonomy of scenarios of suboptimal clinician guideline adherence in the management of severe hypertension. PARTICIPANTS: We identified patients with markedly elevated blood pressure ([BP]; defined as at least 2 consecutive readings of BP ≥160/100 mmHg) and no prescription for antihypertensive medication within a 90-day of the 2nd BP elevation (n=4,828). We randomly selected 100 records from the group of all eligible patients for qualitative analysis. MAIN OUTCOMES AND MEASURES: The scenarios and influencing factors contributing to clinician non-adherence to the guidelines for hypertension management. RESULTS: Thematic saturation was reached after analyzing 100 patient records. Three content domains emerged: clinician-related scenarios (neglect and diffusion of responsibility), patient-related scenarios (patient non-adherence and patient preference), and clinical complexity-related scenarios (diagnostic uncertainty, maintenance of current intervention and competing medical priorities). Through a metareview of literature, we identified several plausible influencing factors, including a lack of protocols and processes that clearly define the roles within the institution to implement guidelines, infrastructure limitations, and clinicians' lack of autonomy and authority, excessive workload, time constraints, clinician belief that intervention was not part of their role, or perception that guidelines restrict clinical judgment. CONCLUSIONS AND RELEVANCE: This study illuminates reasons for suboptimal adherence to guidelines for managing markedly elevated BP. The taxonomy of suboptimal adherence scenarios, derived from real-world EHR data, is pragmatic and provides a basis for developing targeted interventions to improve clinician guideline adherence and patient outcomes.

6.
JAMA Netw Open ; 6(12): e2345964, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38039001

RESUMO

Importance: Despite efforts to improve the quality of care for patients with atherosclerotic cardiovascular disease (ASCVD), it is unclear whether the US has made progress in reducing racial and ethnic differences in utilization of guideline-recommended therapies for secondary prevention. Objective: To evaluate 21-year trends in racial and ethnic differences in utilization of guideline-recommended pharmacological medications and lifestyle modifications among US adults with ASCVD. Design, Setting, and Participants: This cross-sectional study includes data from the National Health and Nutrition Examination Survey between 1999 and 2020. Eligible participants were adults aged 18 years or older with a history of ASCVD. Data were analyzed between March 2022 and May 2023. Exposure: Self-reported race and ethnicity. Main Outcome and Measures: Rates and racial and ethnic differences in the use of guideline-recommended pharmacological medications and lifestyle modifications. Results: The study included 5218 adults with a history of ASCVD (mean [SD] age, 65.5 [13.2] years, 2148 women [weighted average, 44.2%]), among whom 1170 (11.6%) were Black, 930 (7.7%) were Hispanic or Latino, and 3118 (80.7%) were White in the weighted sample. Between 1999 and 2020, there was a significant increase in total cholesterol control and statin use in all racial and ethnic subgroups, and in angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) utilization in non-Hispanic White individuals and Hispanic and Latino individuals (Hispanic and Latino individuals: 17.12 percentage points; 95% CI, 0.37-37.88 percentage points; P = .046; non-Hispanic White individuals: 12.14 percentage points; 95% CI, 6.08-18.20 percentage points; P < .001), as well as smoking cessation within the Hispanic and Latino population (-27.13 percentage points; 95% CI, -43.14 to -11.12 percentage points; P = .002). During the same period, the difference in smoking cessation between Hispanic and Latino individuals and White individuals was reduced (-24.85 percentage points; 95% CI, -38.19 to -11.51 percentage points; P < .001), but racial and ethnic differences for other metrics did not change significantly. Notably, substantial gaps persisted between current care and optimal care throughout the 2 decades of data analyzed. In the period of 2017 to 2020, optimal regimens were observed in 47.4% (95% CI, 39.3%-55.4%), 48.7% (95% CI, 36.7%-60.6%), and 53.0% (95% CI, 45.6%-60.4%) of Black, Hispanic and Latino, and White individuals, respectively. Conclusions and Relevance: In this cross-sectional study of US adults with ASCVD, significant disparities persisted between current care and optimal care, surpassing any differences observed among demographic groups. These findings highlight the critical need for sustained efforts to bridge these gaps and achieve better outcomes for all patients, regardless of their racial and ethnic backgrounds.


Assuntos
Doenças Cardiovasculares , Adulto , Humanos , Feminino , Idoso , Inquéritos Nutricionais , Estudos Transversais , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina
7.
BMJ Med ; 2(1): e000651, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37829182

RESUMO

Objective: To assess the uptake of second line antihyperglycaemic drugs among patients with type 2 diabetes mellitus who are receiving metformin. Design: Federated pharmacoepidemiological evaluation in LEGEND-T2DM. Setting: 10 US and seven non-US electronic health record and administrative claims databases in the Observational Health Data Sciences and Informatics network in eight countries from 2011 to the end of 2021. Participants: 4.8 million patients (≥18 years) across US and non-US based databases with type 2 diabetes mellitus who had received metformin monotherapy and had initiated second line treatments. Exposure: The exposure used to evaluate each database was calendar year trends, with the years in the study that were specific to each cohort. Main outcomes measures: The outcome was the incidence of second line antihyperglycaemic drug use (ie, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter-2 inhibitors, dipeptidyl peptidase-4 inhibitors, and sulfonylureas) among individuals who were already receiving treatment with metformin. The relative drug class level uptake across cardiovascular risk groups was also evaluated. Results: 4.6 million patients were identified in US databases, 61 382 from Spain, 32 442 from Germany, 25 173 from the UK, 13 270 from France, 5580 from Scotland, 4614 from Hong Kong, and 2322 from Australia. During 2011-21, the combined proportional initiation of the cardioprotective antihyperglycaemic drugs (glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors) increased across all data sources, with the combined initiation of these drugs as second line drugs in 2021 ranging from 35.2% to 68.2% in the US databases, 15.4% in France, 34.7% in Spain, 50.1% in Germany, and 54.8% in Scotland. From 2016 to 2021, in some US and non-US databases, uptake of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors increased more significantly among populations with no cardiovascular disease compared with patients with established cardiovascular disease. No data source provided evidence of a greater increase in the uptake of these two drug classes in populations with cardiovascular disease compared with no cardiovascular disease. Conclusions: Despite the increase in overall uptake of cardioprotective antihyperglycaemic drugs as second line treatments for type 2 diabetes mellitus, their uptake was lower in patients with cardiovascular disease than in people with no cardiovascular disease over the past decade. A strategy is needed to ensure that medication use is concordant with guideline recommendations to improve outcomes of patients with type 2 diabetes mellitus.

8.
Nano Lett ; 23(18): 8650-8656, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37704584

RESUMO

The long-sought Chern insulators that manifest a quantum anomalous Hall effect are typically considered to occur in ferromagnets. Here, we theoretically predict the realizabilities of Chern insulators in antiferromagnets, in which the magnetic sublattices are connected by symmetry operators enforcing zero net magnetic moment. Our symmetry analysis provides comprehensive magnetic layer point groups that allow antiferromagnetic (AFM) Chern insulators, revealing that an in-plane magnetic configuration is required. Followed by first-principles calculations, such design principles naturally lead to two categories of material candidates, exemplified by monolayer RbCr4S8 and bilayer Mn3Sn with collinear and noncollinear AFM orders, respectively. We further show that the Chern number could be tuned by slight ferromagnetic canting as an effective pivot. Our work elucidates the nature of the Chern-insulator phase in AFM systems, paving a new avenue for designing quantum anomalous Hall insulators with the integration of nondissipative transport and the promising advantages of the AFM order.

9.
JAMA ; 329(19): 1662-1670, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37191702

RESUMO

Importance: Amid efforts in the US to promote health equity, there is a need to assess recent progress in reducing excess deaths and years of potential life lost among the Black population compared with the White population. Objective: To evaluate trends in excess mortality and years of potential life lost among the Black population compared with the White population. Design, setting, and participants: Serial cross-sectional study using US national data from the Centers for Disease Control and Prevention from 1999 through 2020. We included data from non-Hispanic White and non-Hispanic Black populations across all age groups. Exposures: Race as documented in the death certificates. Main outcomes and measures: Excess age-adjusted all-cause mortality, cause-specific mortality, age-specific mortality, and years of potential life lost rates (per 100 000 individuals) among the Black population compared with the White population. Results: From 1999 to 2011, the age-adjusted excess mortality rate declined from 404 to 211 excess deaths per 100 000 individuals among Black males (P for trend <.001). However, the rate plateaued from 2011 through 2019 (P for trend = .98) and increased in 2020 to 395-rates not seen since 2000. Among Black females, the rate declined from 224 excess deaths per 100 000 individuals in 1999 to 87 in 2015 (P for trend <.001). There was no significant change between 2016 and 2019 (P for trend = .71) and in 2020 rates increased to 192-levels not seen since 2005. The trends in rates of excess years of potential life lost followed a similar pattern. From 1999 to 2020, the disproportionately higher mortality rates in Black males and females resulted in 997 623 and 628 464 excess deaths, respectively, representing a loss of more than 80 million years of life. Heart disease had the highest excess mortality rates, and the excess years of potential life lost rates were largest among infants and middle-aged adults. Conclusions and relevance: Over a recent 22-year period, the Black population in the US experienced more than 1.63 million excess deaths and more than 80 million excess years of life lost when compared with the White population. After a period of progress in reducing disparities, improvements stalled, and differences between the Black population and the White population worsened in 2020.


Assuntos
Negro ou Afro-Americano , Expectativa de Vida , Mortalidade , Adulto , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , População Negra/estatística & dados numéricos , Estudos Transversais , Etnicidade , Promoção da Saúde , Expectativa de Vida/etnologia , Expectativa de Vida/tendências , Mortalidade/etnologia , Mortalidade/tendências , Estados Unidos/epidemiologia , Negro ou Afro-Americano/estatística & dados numéricos , Brancos/estatística & dados numéricos
10.
Nat Commun ; 14(1): 2905, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37217499

RESUMO

The century-long development of surface sciences has witnessed the discoveries of a variety of quantum states. In the recently proposed "obstructed atomic insulators", symmetric charges are pinned at virtual sites where no real atoms reside. The cleavage through these sites could lead to a set of obstructed surface states with partial electronic occupation. Here, utilizing scanning tunneling microscopy, angle-resolved photoemission spectroscopy and first-principles calculations, we observe spectroscopic signature of obstructed surface states in SrIn2P2. We find that a pair of surface states that are originated from the pristine obstructed surface states split in energy by a unique surface reconstruction. The upper branch is marked with a striking differential conductance peak followed by negative differential conductance, signaling its localized nature, while the lower branch is found to be highly dispersive. This pair of surface states is in consistency with our calculational results. Our finding not only demonstrates a surface quantum state induced by a new type of bulk-boundary correspondence, but also provides a platform for exploring efficient catalysts and related surface engineering.

11.
J Am Med Inform Assoc ; 30(5): 943-952, 2023 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-36905605

RESUMO

OBJECTIVE: Nonexercise algorithms are cost-effective methods to estimate cardiorespiratory fitness (CRF), but the existing models have limitations in generalizability and predictive power. This study aims to improve the nonexercise algorithms using machine learning (ML) methods and data from US national population surveys. MATERIALS AND METHODS: We used the 1999-2004 data from the National Health and Nutrition Examination Survey (NHANES). Maximal oxygen uptake (VO2 max), measured through a submaximal exercise test, served as the gold standard measure for CRF in this study. We applied multiple ML algorithms to build 2 models: a parsimonious model using commonly available interview and examination data, and an extended model additionally incorporating variables from Dual-Energy X-ray Absorptiometry (DEXA) and standard laboratory tests in clinical practice. Key predictors were identified using Shapley additive explanation (SHAP). RESULTS: Among the 5668 NHANES participants in the study population, 49.9% were women and the mean (SD) age was 32.5 years (10.0). The light gradient boosting machine (LightGBM) had the best performance across multiple types of supervised ML algorithms. Compared with the best existing nonexercise algorithms that could be applied to the NHANES, the parsimonious LightGBM model (RMSE: 8.51 ml/kg/min [95% CI: 7.73-9.33]) and the extended LightGBM model (RMSE: 8.26 ml/kg/min [95% CI: 7.44-9.09]) significantly reduced the error by 15% and 12% (P < .001 for both), respectively. DISCUSSION: The integration of ML and national data source presents a novel approach for estimating cardiovascular fitness. This method provides valuable insights for cardiovascular disease risk classification and clinical decision-making, ultimately leading to improved health outcomes. CONCLUSION: Our nonexercise models provide improved accuracy in estimating VO2 max within NHANES data as compared to existing nonexercise algorithms.


Assuntos
Teste de Esforço , Exercício Físico , Adulto , Feminino , Humanos , Masculino , Teste de Esforço/métodos , Aprendizado de Máquina , Inquéritos Nutricionais , Oxigênio , Adulto Jovem
12.
Circ Cardiovasc Qual Outcomes ; 16(4): e009258, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36883456

RESUMO

BACKGROUND: Visit-to-visit variability (VVV) in blood pressure values has been reported in clinical studies. However, little is known about VVV in clinical practice and whether it is associated with patient characteristics in real-world setting. METHODS: We conducted a retrospective cohort study to quantify VVV in systolic blood pressure (SBP) values in a real-world setting. We included adults (age ≥18 years) with at least 2 outpatient visits between January 1, 2014 and October 31, 2018 from Yale New Haven Health System. Patient-level measures of VVV included SD and coefficient of variation of a given patient's SBP across visits. We calculated patient-level VVV overall and by patient subgroups. We further developed a multilevel regression model to assess the extent to which VVV in SBP was explained by patient characteristics. RESULTS: The study population included 537 218 adults, with a total of 7 721 864 SBP measurements. The mean age was 53.4 (SD 19.0) years, 60.4% were women, 69.4% were non-Hispanic White, and 18.1% were on antihypertensive medications. Patients had a mean body mass index of 28.4 (5.9) kg/m2 and 22.6%, 8.0%, 9.7%, and 5.6% had a history of hypertension, diabetes, hyperlipidemia, and coronary artery disease, respectively. The mean number of visits per patient was 13.3, over an average period of 2.4 years. The mean (SD) intraindividual SD and coefficient of variation of SBP across visits were 10.6 (5.1) mm Hg and 0.08 (0.04). These measures of blood pressure variation were consistent across patient subgroups defined by demographic characteristics and medical history. In the multivariable linear regression model, only 4% of the variance in absolute standardized difference was attributable to patient characteristics. CONCLUSIONS: The VVV in real-world practice poses challenges for management of patients with hypertension based on blood pressure readings in outpatient settings and suggest the need to go beyond episodic clinic evaluation.


Assuntos
Hipertensão , Adulto , Humanos , Feminino , Pessoa de Meia-Idade , Adolescente , Masculino , Pressão Sanguínea , Estudos Retrospectivos , Fatores de Risco , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Determinação da Pressão Arterial
13.
Conserv Biol ; 37(5): e14072, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-36748394

RESUMO

Mass media worldwide has contributed to increasing awareness of the illegal wildlife trade and its significant impact on wildlife conservation. We used mass media coverage as a proxy for macro-level public opinion to analyze the media framing of elephant ivory in 6394 Chinese newspaper articles published from 2000 to 2021 and thus determine the effects of wildlife policies on public opinion. We focused on 2 events: the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) approval of China as a trading partner in the purchase and import of ivory stockpiles from Africa in July 2008 and the Chinese government's announcement of a domestic ivory ban in December 2016. Using latent Dirichlet allocation topic modeling, we identified 8 topics about elephant ivory and grouped them into 3 frames: ivory arts and culture, ivory crimes, and elephant conservation. Over the last 2 decades, topics related to ivory crimes remained the most prevalent in news articles. Topics about ivory arts and culture showed a significant shift in media salience before and after the 2 events (from 0.44 to 0.19 and from 0.08 to 0.15, respectively, p < 0.05), whereas the other 2 frames did not change significantly. Contrary to popular belief, our results indicated that Chinese macro-level public opinion on ivory had become more negative following the CITES approval of ivory importation and less negative after the ivory ban announcement, at least for certain periods. The relationship between mass media, public opinion, and wildlife trade policies is complex and requires further examination of the sociopolitical dynamics that influence media narratives. Our results showed the value of topic modeling in monitoring and assessing media representations of wildlife issues in the era of big data. Conservationists should remain vigilant of mass media coverage and collaborate with media practitioners to produce comprehensive narratives on wildlife issues if resources permit.


Los medios masivos han contribuido a una mayor conciencia mundial del mercado ilegal de fauna y el impacto significativo que tiene sobre la conservación. Usamos la cobertura de los medios masivos como sustituto de la opinión pública a nivel macro para analizar el encuadre mediático que le dan al marfil 6,394 artículos publicados en periódicos chinos entre el 2000 y 2021 para así determinar los efectos que tienen las políticas de fauna sobre la opinión pública. Nos enfocamos en dos eventos: la autorización que dio la Convención sobre el Comercio Internacional de Especies Amenazadas (CITES) a China como socio comercial en la compra e importación de reservas de marfil desde África en julio de 2008 y la prohibición doméstica de marfil anunciada por el gobierno chino en diciembre de 2016. Usamos el modelado de asignación latente de Dirichlet para identificar ocho temas sobre el marfil y los agrupamos en tres encuadres: arte y cultura del marfil, crimen del marfil y conservación de elefantes. Durante las últimas dos décadas, los temas relacionados con los crímenes del marfil fueron los más prevalentes en los artículos periodísticos. Los temas relacionados al arte y cultura del marfil mostraron un cambio significativo en la relevancia mediática antes y después de los dos eventos (de 0.44 a 0.19 y de 0.08 a 0.15, respectivamente, p<0.05), mientras que los otros dos encuadres no cambiaron significativamente. Contrario a las creencias populares, nuestros resultados indicaron que la opinión pública a nivel macro sobre el marfil en China se ha vuelto más negativa después de la autorización de CITES y menos negativa después de la prohibición del marfil, al menos durante ciertos periodos. La relación entre los medios masivos, la opinión pública y las políticas del comercio de fauna es compleja y requiere un análisis más profundo de las dinámicas sociopolíticas que influyen sobre las narrativas mediáticas. Nuestros resultados muestran el valor del modelado de temas en el monitoreo y evaluación de la representación en medios de los temas sobre fauna en tiempos de los macrodatos. Los conservacionistas deberían permanecer atentos a la cobertura de los medios masivos y colaborar con los profesionales de los medios para producir narraciones completas sobre la fauna si los recursos lo permiten.


Assuntos
Elefantes , Animais , Conservação dos Recursos Naturais , Comércio , Internacionalidade , Animais Selvagens
14.
Nano Lett ; 23(2): 414-421, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36607246

RESUMO

Heterostructures composed of the intrinsic magnetic topological insulator MnBi2Te4 and its nonmagnetic counterpart Bi2Te3 host distinct surface electronic band structures depending on the stacking order and exposed termination. Here, we probe the ultrafast dynamical response of MnBi2Te4 and MnBi4Te7 following near-infrared optical excitation using time- and angle-resolved photoemission spectroscopy and disentangle surface from bulk dynamics based on density functional theory slab calculations of the surface-projected electronic structure. We gain access to the out-of-equilibrium charge carrier populations of both MnBi2Te4 and Bi2Te3 surface terminations of MnBi4Te7, revealing an instantaneous occupation of states associated with the Bi2Te3 surface layer followed by carrier extraction into the adjacent MnBi2Te4 layers with a laser fluence-tunable delay of up to 350 fs. The ensuing thermal relaxation processes are driven by phonon scattering with significantly slower relaxation times in the magnetic MnBi2Te4 septuple layers. The observed competition between interlayer charge transfer and intralayer phonon scattering demonstrates a method to control ultrafast charge transfer processes in MnBi2Te4-based van der Waals compounds.

15.
J Am Heart Assoc ; 11(19): e025545, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36172953

RESUMO

Background Semaglutide holds the promise for weight loss and risk reduction. Less is known about racial and ethnic disparities in financial barriers among the semaglutide-eligible population. Methods and Results We conducted a cross-sectional analysis of adults aged 18 years or older using data from the National Health and Nutrition Examination Survey 2015 to 2020. We analyzed adults eligible for semaglutide based on Food and Drug Administration labeling and assessed financial barriers and social determinants of health among the eligible population overall and by race and ethnicity. A total of 13 711 adults were included in the final analysis. In 2015 to 2020, 51.1% (48.3%-53.2%) of US adults (≈43.3 million) met the Food and Drug Administration eligibility criteria for semaglutide. The percentage of adults eligible for semaglutide was highest among Black adults (56.6% [54.2%-59.1%]), followed by Hispanic adults (55.0% [52.8%-57.3%]). Among adults eligible for semaglutide, 11.9% (10.1%-13.6%) were uninsured, 13.3% (12.1%-14.5%) lacked a usual source of care, 33.6% (30.2%-36.9%) had low family income, and 38.9% (36.5%-41.3%) lacked higher education. Compared with White individuals, significantly larger proportions of Black and Hispanic individuals were uninsured, lacked a usual source of care, had low family income, or lacked higher education (P<0.001 for all). Conclusions Many Americans who were eligible for semaglutide were likely to be unable to afford the medication. Among the eligible population, a larger proportion of Black and Hispanic adults had financial barriers than other subgroups.


Assuntos
Etnicidade , Sobrepeso , Adulto , Negro ou Afro-Americano , Estudos Transversais , Peptídeos Semelhantes ao Glucagon , Humanos , Inquéritos Nutricionais , Obesidade/epidemiologia , Estados Unidos/epidemiologia
16.
JAMA Netw Open ; 5(5): e229953, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35503221

RESUMO

Importance: An increasing proportion of people in the US hospitalized for acute myocardial infarction (AMI) are younger than 55 years, with the largest increase in young women. Effective prevention requires an understanding of risk factors associated with risk of AMI in young women compared with men. Objectives: To assess the sex-specific associations of demographic, clinical, and psychosocial risk factors with first AMI among adults younger than 55 years, overall, and by AMI subtype. Design, Setting, and Participants: This study used a case-control design with 2264 patients with AMI, aged 18 to 55 years, from the VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients) study and 2264 population-based controls matched for age, sex, and race and ethnicity from the National Health and Nutrition Examination Survey from 2008 to 2012. Data were analyzed from April 2020 to November 2021. Exposures: A wide range of demographic, clinical, and psychosocial risk factors. Main Outcomes and Measures: Odds ratios (ORs) and population attributable fractions (PAF) for first AMI associated with demographic, clinical, and psychosocial risk factors. Results: Of the 4528 case patients and matched controls, 3122 (68.9%) were women, and the median (IQR) age was 48 (44-52) years. Seven risk factors (diabetes [OR, 3.59 (95% CI, 2.72-4.74) in women vs 1.76 (1.19-2.60) in men], depression [OR, 3.09 (95% CI, 2.37-4.04) in women vs 1.77 (1.15-2.73) in men], hypertension [OR, 2.87 (95% CI, 2.31-3.57) in women vs 2.19 (1.65-2.90) in men], current smoking [OR, 3.28 (95% CI, 2.65-4.07) in women vs 3.28 (2.65-4.07) in men], family history of premature myocardial infarction [OR, 1.48 (95% CI, 1.17-1.88) in women vs 2.42 (1.71-3.41) in men], low household income [OR, 1.79 (95% CI, 1.28-2.50) in women vs 1.35 (0.82-2.23) in men], hypercholesterolemia [OR, 1.02 (95% CI, 0.81-1.29) in women vs 2.16 (1.49-3.15) in men]) collectively accounted for the majority of the total risk of AMI in women (83.9%) and men (85.1%). There were significant sex differences in risk factor associations: hypertension, depression, diabetes, current smoking, and family history of diabetes had stronger associations with AMI in young women, whereas hypercholesterolemia had a stronger association in young men. Risk factor profiles varied by AMI subtype, and traditional cardiovascular risk factors had higher prevalence and stronger ORs for type 1 AMI compared with other AMI subtypes. Conclusions and Relevance: In this case-control study, 7 risk factors, many potentially modifiable, accounted for 85% of the risk of first AMI in young women and men. Significant differences in risk factor profiles and risk factor associations existed by sex and by AMI subtype. These findings suggest the need for sex-specific strategies in risk factor modification and prevention of AMI in young adults. Further research is needed to improve risk assessment of AMI subtypes.


Assuntos
Diabetes Mellitus , Hipercolesterolemia , Hipertensão , Infarto do Miocárdio , Estudos de Casos e Controles , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Hipertensão/complicações , Masculino , Infarto do Miocárdio/diagnóstico , Inquéritos Nutricionais , Fatores de Risco , Adulto Jovem
17.
Hypertension ; 79(1): 207-217, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34775785

RESUMO

Poor hypertension awareness and underuse of guideline-recommended medications are critical factors contributing to poor hypertension control. Using data from 8095 hypertensive people aged ≥18 years from the National Health and Nutrition Examination Survey (2011-2018), we examined recent trends in racial and ethnic differences in awareness and antihypertensive medication use, and their association with racial and ethnic differences in hypertension control. Between 2011 and 2018, age-adjusted hypertension awareness declined for Black, Hispanic, and White individuals, but the 3 outcomes increased or did not change for Asian individuals. Compared with White individuals, Black individuals had a similar awareness (odds ratio, 1.20 [0.96-1.45]) and overall treatment rates (1.04 [0.84-1.25]), and received more intensive antihypertensive medication if treated (1.41 [1.27-1.56]), but had a lower control rate (0.72 [0.61-0.83]). Asian and Hispanic individuals had significantly lower awareness rates (0.69 [0.52-0.85] and 0.74 [0.59-0.89]), overall treatment rates (0.72 [0.57-0.88] and 0.69 [0.55-0.82]), received less intensive medication if treated (0.60 [0.50-0.72] and 0.86 [0.75-0.96]), and had lower control rates (0.66 [0.54-0.79] and 0.69 [0.57-0.81]). The racial and ethnic differences in awareness, treatment, and control persisted over the study period and were consistent across age, sex, and income strata. Lower awareness and treatment were significantly associated with lower control in Asian and Hispanic individuals (P<0.01 for all) but not in Black individuals. These findings highlight the need for interventions to improve awareness and treatment among Asian and Hispanic individuals, and more investigation into the downstream factors that may contribute to the poor hypertension control among Black individuals.


Assuntos
Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Etnicidade , Feminino , Disparidades nos Níveis de Saúde , Disparidades em Assistência à Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Grupos Raciais , Estados Unidos , Adulto Jovem
18.
Nano Lett ; 21(13): 5874-5880, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34197120

RESUMO

The magnetic structures of MnBi2Te4(Bi2Te3)n can be manipulated by tuning the interlayer coupling via the number of Bi2Te3 spacer layers n, while the intralayer ferromagnetic (FM) exchange coupling is considered too robust to control. By applying hydrostatic pressure up to 3.5 GPa, we discover opposite responses of magnetic properties for n = 1 and 2. MnBi4Te7 stays at A-type antiferromagnetic (AFM) phase with a decreasing Néel temperature and an increasing saturation field. In sharp contrast, MnBi6Te10 experiences a phase transition from A-type AFM to a quasi-two-dimensional FM state with a suppressed saturation field under pressure. First-principles calculations reveal the essential role of intralayer exchange coupling from lattice compression in determining these magnetic properties. Such magnetic phase transition is also observed in 20% Sb-doped MnBi6Te10 because of the in-plane lattice compression.

19.
Nat Commun ; 11(1): 97, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31911588

RESUMO

Magnetic topological insulators (TI) provide an important material platform to explore quantum phenomena such as quantized anomalous Hall effect and Majorana modes, etc. Their successful material realization is thus essential for our fundamental understanding and potential technical revolutions. By realizing a bulk van der Waals material MnBi4Te7 with alternating septuple [MnBi2Te4] and quintuple [Bi2Te3] layers, we show that it is ferromagnetic in plane but antiferromagnetic along the c axis with an out-of-plane saturation field of ~0.22 T at 2 K. Our angle-resolved photoemission spectroscopy measurements and first-principles calculations further demonstrate that MnBi4Te7 is a Z2 antiferromagnetic TI with two types of surface states associated with the [MnBi2Te4] or [Bi2Te3] termination, respectively. Additionally, its superlattice nature may make various heterostructures of [MnBi2Te4] and [Bi2Te3] layers possible by exfoliation. Therefore, the low saturation field and the superlattice nature of MnBi4Te7 make it an ideal system to investigate rich emergent phenomena.

20.
RSC Adv ; 9(2): 668-674, 2019 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-35517619

RESUMO

µ-Conotoxin PIIIA, a peptide toxin isolated from Conus purpurascens, blocks the skeletal muscle voltage-gated sodium channel NaV1.4 with significant potency. PIIIA has three disulfide bonds, which contribute largely to its highly constrained and stable structure. In this study, a combination of experimental studies and computational modeling were performed to assess the effects of deletion of the disulfide bonds on the structure and activity of PIIIA. The final results indicate that the three disulfide bonds of PIIIA are required to produce the effective inhibition of NaV1.4, and the removal of any one of the disulfide bonds significantly reduces its binding affinity owing to secondary structure variation, among which the Cys11-Cys22 is the most important for sustaining the structure and activity of PIIIA.

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