RESUMEN
BACKGROUND: Disparities in hypertension control are well documented but underaddressed. METHODS: RICH LIFE (Reducing Inequities in Care of Hypertension: Lifestyle Improvement for Everyone) was a 2-arm, cluster randomized trial comparing the effect on blood pressure (BP) control (systolic BP ≤140 mm Hg, diastolic BP ≤90 mm Hg), patient activation, and disparities in BP control of 2 multilevel interventions, standard of care plus (SCP) and collaborative care/stepped care (CC/SC). SCP included BP measurement standardization, audit and feedback, and equity-leadership training. CC/SC added roles to address social or medical needs. Primary outcomes were BP control and patient activation at 12 months. Generalized estimating equations and mixed-effects regression models with fixed effects of time, intervention, and their interaction compared change in outcomes at 12 months from baseline. RESULTS: A total of 1820 adults with uncontrolled BP and ≥1 other risk factors enrolled in the study. Their mean age was 60.3 years, and baseline BP was 152.3/85.5 mm Hg; 59.4% were women; 57.4% were Black, 33.2% were White, and 9.4% were Hispanic; 74% had hyperlipidemia; and 45.1% had type 2 diabetes. CC/SC did not improve BP control rates more than SCP. Both groups achieved statistically and clinically significant BP control rates at 12 months (CC/SC: 57.3% [95% CI, 52.7%-62.0%]; SCP: 56.7% [95% CI, 51.9%-61.5%]). Pairwise comparisons between racial and ethnic groups showed overall no significant differences in BP control at 12 months. Patients with coronary heart disease showed greater achievement of BP control in CC/SC than in SCP (64.0% [95% CI, 54.1%-73.9%] versus 50.8% [95% CI, 42.6%-59.0%]; P=0.04), as did patients in rural areas (67.3% [95% CI, 49.8%-84.8%] versus 47.8% [95% CI, 32.4%-63.2%]; P=0.01). Individuals in both arms experienced statistically and clinically significant reductions in mean systolic BP (CC/SC: -13.8 mm Hg [95% CI, -15.2 to -12.5]; SCP: -14.6 mm Hg [95% CI, -15.9 to -13.2]) and diastolic BP (CC/SC: -6.9 mm Hg [95% CI, -7.8 to -6.1]; SCP: -5.5 mm Hg [95% CI, -6.4 to -4.6]) over time. The difference in diastolic BP reduction between CC/SC and SCP over time was statistically significant (-1.4 mm Hg [95% CI, -2.6 to -0.2). Patient activation did not differ between arms. CC/SC showed greater improvements in patient ratings of chronic illness care (Patient Assessment of Chronic Illness Care score) over 12 months (0.12 [95% CI, 0.02-0.22]). CONCLUSIONS: Adding a collaborative care team to enhanced standard of care did not improve BP control but did improve patient ratings of chronic illness care.
Asunto(s)
Presión Sanguínea , Hipertensión , Medición de Resultados Informados por el Paciente , Humanos , Hipertensión/terapia , Hipertensión/fisiopatología , Hipertensión/diagnóstico , Femenino , Masculino , Persona de Mediana Edad , Anciano , Disparidades en Atención de Salud , Resultado del Tratamiento , Antihipertensivos/uso terapéuticoRESUMEN
Electron-spin qubits have long coherence times suitable for quantum technologies. Spin-orbit coupling promises to greatly improve spin qubit scalability and functionality, allowing qubit coupling via photons, phonons or mutual capacitances, and enabling the realization of engineered hybrid and topological quantum systems. However, despite much recent interest, results to date have yielded short coherence times (from 0.1 to 1 µs). Here we demonstrate ultra-long coherence times of 10 ms for holes where spin-orbit coupling yields quantized total angular momentum. We focus on holes bound to boron acceptors in bulk silicon 28, whose wavefunction symmetry can be controlled through crystal strain, allowing direct control over the longitudinal electric dipole that causes decoherence. The results rival the best electron-spin qubits and are 104 to 105 longer than previous spin-orbit qubits. These results open a pathway to develop new artificial quantum systems and to improve the functionality and scalability of spin-based quantum technologies.
RESUMEN
A requirement for quantum information processors is the in situ tunability of the tunnel rates and the exchange interaction energy within the device. The large energy level separation for atom qubits in silicon is well suited for qubit operation but limits device tunability using in-plane gate architectures, requiring vertically separated top-gates to control tunnelling within the device. In this paper, we address control of the simplest tunnelling device in Si:P, the tunnel junction. Here we demonstrate that we can tune its conductance by using a vertically separated top-gate aligned with ±5 nm precision to the junction. We show that a monolithic 3D epitaxial top-gate increases the capacitive coupling by a factor of 3 compared to in-plane gates, resulting in a tunnel barrier height tunability of 0-186 meV. By combining multiple gated junctions in series we extend our monolithic 3D gating technology to implement nanoscale logic circuits including AND and OR gates.
RESUMEN
BACKGROUND: Effective hypertension self-management interventions are needed for socially disadvantaged African Americans, who have poorer blood pressure (BP) control compared to others. OBJECTIVE: We studied the incremental effectiveness of contextually adapted hypertension self-management interventions among socially disadvantaged African Americans. DESIGN: Randomized comparative effectiveness trial. PARTICIPANTS: One hundred fifty-nine African Americans at an urban primary care clinic. INTERVENTIONS: Participants were randomly assigned to receive (1) a community health worker ("CHW") intervention, including the provision of a home BP monitor; (2) the CHW plus additional training in shared decision-making skills ("DoMyPART"); or (3) the CHW plus additional training in self-management problem-solving ("Problem Solving"). MAIN MEASURES: We assessed group differences in BP control (systolic BP (SBP) < 140 mm Hg and diastolic BP (DBP) < 90 mmHg), over 12 months using generalized linear mixed models. We also assessed changes in SBP and DBP and participants' BP self-monitoring frequency, clinic visit patient-centeredness (i.e., extent of patient-physician discussions focused on patient emotional and psychosocial concerns), hypertension self-management behaviors, and self-efficacy. KEY RESULTS: BP control improved in all groups from baseline (36%) to 12 months (52%) with significant declines in SBP (estimated mean [95% CI] - 9.1 [- 15.1, - 3.1], - 7.4 [- 13.4, - 1.4], and - 11.3 [- 17.2, - 5.3] mmHg) and DBP (- 4.8 [- 8.3, - 1.3], - 4.0 [- 7.5, - 0.5], and - 5.4 [- 8.8, - 1.9] mmHg) for CHW, DoMyPART, and Problem Solving, respectively). There were no group differences in BP outcomes, BP self-monitor use, or clinic visit patient-centeredness. The Problem Solving group had higher odds of high hypertension self-care behaviors (OR [95% CI] 18.7 [4.0, 87.3]) and self-efficacy scores (OR [95% CI] 4.7 [1.5, 14.9]) at 12 months compared to baseline, while other groups did not. Compared to DoMyPART, the Problem Solving group had higher odds of high hypertension self-care behaviors (OR [95% CI] 5.7 [1.3, 25.5]) at 12 months. CONCLUSION: A context-adapted CHW intervention was correlated with improvements in BP control among socially disadvantaged African Americans. However, it is not clear whether improvements were the result of this intervention. Neither the addition of shared decision-making nor problem-solving self-management training to the CHW intervention further improved BP control. TRIAL REGISTRY: ClinicalTrials.gov Identifier: NCT01902719.
Asunto(s)
Hipertensión , Automanejo , Negro o Afroamericano , Antihipertensivos/uso terapéutico , Presión Sanguínea , Humanos , Hipertensión/tratamiento farmacológico , Hipertensión/terapia , Poblaciones VulnerablesRESUMEN
We present a donor-based quadruple-quantum-dot device, designed to host two singlet-triplet qubits fabricated by scanning tunnelling microscope lithography, with just two leads per qubit. The design is geometrically compact, with each pair of dots independently controlled via one gate and one reservoir. The reservoirs both supply electrons for the dots and measure the singlet-triplet state of each qubit via dispersive sensing. We verify the locations of the four phosphorus donor dots via an electrostatic model of the device. We study one of the observed singlet-triplet states with a tunnel coupling of 39 GHz and a S0-to- T- decay of 2 ms at zero detuning. We measure a 5 GHz electrostatic interaction between two pairs of dots separated by 65 nm. The results outline a low-gate-density pathway to a scalable 1D building block of atomic-precision singlet-triplet qubits using donors with dispersive readout.
RESUMEN
The atomically precise doping of silicon with phosphorus (Si:P) using scanning tunneling microscopy (STM) promises ultimate miniaturization of field effect transistors. The one-dimensional (1D) Si:P nanowires are of particular interest, retaining exceptional conductivity down to the atomic scale, and are predicted as interconnects for a scalable silicon-based quantum computer. Here, we show that ultrathin Si:P nanowires form one of the most-stable electrical conductors, with the phenomenological Hooge parameter of low-frequency noise being as low as ≈10(-8) at 4.2 K, nearly 3 orders of magnitude lower than even carbon-nanotube-based 1D conductors. A in-built isolation from the surface charge fluctuations due to encapsulation of the wires within the epitaxial Si matrix is the dominant cause for the observed suppression of noise. Apart from quantum information technology, our results confirm the promising prospects for precision-doped Si:P structures in atomic-scale circuitry for the 11 nm technology node and beyond.
RESUMEN
Cardiovascular health disparities persist despite decades of recognition and the availability of evidence-based clinical and public health interventions. Racial and ethnic minorities and adults in urban and low-income communities are high-risk groups for uncontrolled hypertension (HTN), a major contributor to cardiovascular health disparities, in part due to inequitable social structures and economic systems that negatively impact daily environments and risk behaviors. This commentary presents the Johns Hopkins Center to Eliminate Cardiovascular Health Disparities as a case study for highlighting the evolution of an academic-community partnership to overcome HTN disparities. Key elements of the iterative development process of a Community Advisory Board (CAB) are summarized, and major CAB activities and engagement with the Baltimore community are highlighted. Using a conceptual framework adapted from O'Mara-Eves and colleagues, the authors discuss how different population groups and needs, motivations, types and intensity of community participation, contextual factors, and actions have shaped the Center's approach to stakeholder engagement in research and community outreach efforts to achieve health equity.
Asunto(s)
Equidad en Salud , Disparidades en el Estado de Salud , Hipertensión/etnología , Justicia Social , Adulto , Baltimore , Investigación Participativa Basada en la Comunidad , Relaciones Comunidad-Institución , Etnicidad , Humanos , Hipertensión/terapia , Grupos Minoritarios , Pobreza , Grupos RacialesRESUMEN
A detailed theoretical study of the electronic and transport properties of a single atom transistor, where a single phosphorus atom is embedded within a single crystal transistor architecture, is presented. Using a recently reported deterministic single-atom transistor as a reference, the electronic structure of the device is represented atomistically with a tight-binding model, and the channel modulation is simulated self-consistently with a Thomas-Fermi method. The multi-scale modeling approach used allows confirmation of the charging energy of the one-electron donor charge state and explains how the electrostatic environments of the device electrodes affects the donor confinement potential and hence extent in gate voltage of the two-electron charge state. Importantly, whilst devices are relatively insensitive to dopant ordering in the highly doped leads, a â¼1% variation of the charging energy is observed when a dopant is moved just one lattice spacing within the device. The multi-scale modeling method presented here lays a strong foundation for the understanding of single-atom device structures: essential for both classical and quantum information processing.
RESUMEN
We demonstrate serial electron transport through a donor-based triple quantum dot in silicon fabricated with nanoscale precision by scanning tunnelling microscopy lithography. From an equivalent circuit model, we calculate the electrochemical potentials of the dots allowing us to identify ground and excited states in finite bias transport. Significantly, we show that using a scanning tunnelling microscope, we can directly demonstrate that a â¼1 nm difference in interdot distance dramatically affects transport pathways between the three dots.
Asunto(s)
Puntos Cuánticos/química , Silicio/química , Algoritmos , Electroquímica , Transporte de Electrón , Electrones , Microscopía de Túnel de Rastreo , Puntos Cuánticos/ultraestructuraRESUMEN
By suppressing an undesirable surface Umklapp process, it is possible to resolve the two most occupied states (1Γ and 2Γ) in a buried two-dimensional electron gas (2DEG) in silicon. The 2DEG exists because of an atomically sharp profile of phosphorus dopants which have been formed beneath the Si(001) surface (a δ-layer). The energy separation, or valley splitting, of the two most occupied bands has critical implications for the properties of δ-layer derived devices, yet until now, has not been directly measurable. Density functional theory (DFT) allows the 2DEG band structure to be calculated, but without experimental verification the size of the valley splitting has been unclear. Using a combination of direct spectroscopic measurements and DFT we show that the measured band structure is in good qualitative agreement with calculations and reveal a valley splitting of 132 ± 5 meV. We also report the effective mass and occupation of the 2DEG states and compare the dispersions and Fermi surface with DFT.
RESUMEN
The recent observation of ultralow resistivity in highly doped, atomic-scale silicon wires has sparked interest in what limits conduction in these quasi-1D systems. Here we present electron transport measurements of gated Si:P wires of widths 4.6 and 1.5 nm. At 4.6 nm we find an electron mobility, µ(el)≃60 cm²/V s, in excellent agreement with that of macroscopic Hall bars. Metallic conduction persists to millikelvin temperatures where we observe Gaussian conductance fluctuations of order δGâ¼e²/h. In thinner wires (1.5 nm), metallic conduction breaks down at Gâ²e²/h, where localization of carriers leads to Coulomb blockade. Metallic behavior is explained by the large carrier densities in Si:P δ-doped systems, allowing the occupation of all six valleys of the silicon conduction band, enhancing the number of 1D channels and hence the localization length.
RESUMEN
An atomistic method of calculating the spin-lattice relaxation times (T1) is presented for donors in silicon nanostructures comprising of millions of atoms. The method takes into account the full band structure of silicon including the spin-orbit interaction. The electron-phonon Hamiltonian, and hence, the deformation potential, is directly evaluated from the strain-dependent tight-binding Hamiltonian. The technique is applied to single donors and donor clusters in silicon, and explains the variation of T1 with the number of donors and electrons, as well as donor locations. Without any adjustable parameters, the relaxation rates in a magnetic field for both systems are found to vary as B5, in excellent quantitative agreement with experimental measurements. The results also show that by engineering electronic wave functions in nanostructures, T1 times can be varied by orders of magnitude.
RESUMEN
African Americans suffer disproportionately poor hypertension control despite the availability of efficacious interventions. Using principles of community-based participatory research and implementation science, we adapted established hypertension self-management interventions to enhance interventions' cultural relevance and potential for sustained effectiveness among urban African Americans. We obtained input from patients and their family members, their health care providers, and community members. The process required substantial time and resources, and the adapted interventions will be tested in a randomized controlled trial.
Asunto(s)
Negro o Afroamericano , Investigación Participativa Basada en la Comunidad , Hipertensión/etnología , Hipertensión/terapia , Autocuidado/métodos , Humanos , Hipertensión/psicología , Atención Dirigida al Paciente , Autocuidado/psicología , Resultado del Tratamiento , Población UrbanaRESUMEN
This study describes the benefits and challenges of meta-analyses of single-case design research using multilevel modeling. The researchers illustrate procedures for conducting meta-analyses using four-level multilevel modeling through open-source R code. The demonstration uses data from multiple-baseline or multiple-probe across-participant single-case design studies (n = 21) on word problem instruction for students with learning disabilities published between 1975 and 2023. Researchers explore changes in levels and trends between adjacent phases (baseline vs. intervention and intervention vs. maintenance) using the sample data. The researchers conclude that word problem solving of students with learning disabilities varies based on the complexity of the word problem measures involving single-word problem, mixed-word problem, and generalization questions. These moderating effects differed across adjacent phases. These findings extend previous literature on meta-analyses methodology by describing how multilevel modeling can be used to compare the impacts of time-varying predictors within and across cases when analyzing single-case design studies. Future researchers may want to use this methodology to explore the roles of time-varying predictors as well as case or study-level moderators. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
RESUMEN
BACKGROUND: The collection of data on 'infant feeding at hospital discharge' is used to monitor breastfeeding outcomes, health service benchmarking, and research. While some Australian states have clear definitions of this data collection point, there is no operational definition of 'infant feeding at hospital discharge' in the Australian state of New South Wales. Little is known about how midwives interpret the term 'infant feeding at hospital discharge', in particular, the timeframe used to calculate these important indicators. The purpose of this study was to explore midwives' and nurses' practices of reporting 'infant feeding at hospital discharge' in the Australian state of New South Wales. METHODS: An online survey was distributed across public and private maternity hospitals in New South Wales, Australia. The survey asked midwives and nurses their practice of reporting 'infant feeding at discharge' from categories offered by the state Mothers and Babies report of either "full breastfeeding", "any breastfeeding", and "infant formula only". The Qualtrics survey was available from December 2021 to May 2022. RESULTS: There were 319 completed surveys for analysis and all 15 NSW Health Districts were represented. Some participants reported using the timeframe 'since birth' as a reference (39%), however, the majority (54%, n = 173) referenced one of the feeding timeframes within the previous 24 h. Most midwives and nurses (83%, n = 265) recommended 24 h before discharge as the most relevant reference timeframe, and 65% (n = 207) were in favour of recording data on 'exclusive breastfeeding' since birth. CONCLUSION: This study identified multiple practice inconsistencies within New South Wales reporting of 'infant feeding at hospital discharge'. This has ramifications for key health statistics, state reporting, and national benchmarking. While the Baby Friendly Hospital Initiative accreditation requires hospitals to demonstrate and continuously monitor at least a 75% exclusive breastfeeding rate on discharge, only 11 New South Wales facilities have achieved this accreditation. We recommend introducing an option to collect 'exclusive breastfeeding' on discharge' which is in line with participant recommendations and the Baby Friendly Hospital accreditation. Other important considerations are the updated World Health Organization indicators such as, "Ever breastfed"; "Early initiation of breastfeeding" (first hour); "Exclusively breastfed for the first two days after birth".
Asunto(s)
Lactancia Materna , Alta del Paciente , Humanos , Nueva Gales del Sur , Femenino , Encuestas y Cuestionarios , Recién Nacido , Adulto , Enfermeras y Enfermeros , Partería , Lactante , Masculino , EmbarazoRESUMEN
OBJECTIVE: The pharyngeal swallow typically begins within 400 ms following the arrival of a liquid bolus in the pharynx. By contrast, processed food particles aggregate in the valleculae prior to swallow initiation. With solid foods, swallow reaction time (SRT), the interval between bolus passing the ramus of mandible and hyoid burst onset (HYB) can be subdivided into components of vallecular aggregation time (VAT) and the subsequent end of aggregation to hyoid burst interval (EOA-to-HYB). However, expected durations of these timing measures remain unclear. We aimed to study bolus aggregation in healthy swallowing for International Dysphagia Diet Standardisation Initiative Food Levels 5 (minced and moist [MM5]), 6 (soft and bite-sized [SB6]), and 7 (regular [RG7]). Understanding typical patterns and durations of vallecular aggregation with solids in healthy swallowing will inform the identification of impaired swallow timing in patient populations. DESIGN: Twenty healthy adults (10 males, Mage = 28 years, range: 23-55 years) swallowed two boluses each of MM5, SB6, and RG7 foods in videofluoroscopy. Blinded duplicate ratings determined bolus location at swallow onset, SRT, VAT, and EOA-to-HYB. Texture-based differences were measured using Friedman's tests. Bolus location was at/above the valleculae at swallow onset for 85% of boluses, with no differences by texture. SRT, VAT, and EOA-to-HYB did not vary by texture, with overall median values (interquartile range) of 99 ms (-66 to 743 ms) for SRT, 347 ms (66 to 891 ms) for VAT, and -132 ms (-231 to -83 ms) for EOA-to-HYB. CONCLUSIONS: These data corroborate prior evidence that it is not unusual for food particles to aggregate in the valleculae prior to swallow initiation in healthy swallowing. However, durations of vallecular aggregation are typically < 1 s in healthy adults.
Asunto(s)
Deglución , Alimentos , Humanos , Deglución/fisiología , Masculino , Adulto , Persona de Mediana Edad , Femenino , Adulto Joven , Voluntarios Sanos , Tiempo de Reacción , Faringe/fisiología , Trastornos de Deglución/fisiopatología , Hueso Hioides/fisiología , Hueso Hioides/diagnóstico por imagenRESUMEN
Donor-based qubits in silicon, manufactured using scanning tunneling microscope (STM) lithography, provide a promising route to realizing full-scale quantum computing architectures. This is due to the precision of donor placement, long coherence times, and scalability of the silicon material platform. The properties of multiatom quantum dot qubits, however, depend on the exact number and location of the donor atoms within the quantum dots. In this work, we develop machine learning techniques that allow accurate and real-time prediction of the donor number at the qubit site during STM patterning. Machine learning image recognition is used to determine the probability distribution of donor numbers at the qubit site directly from STM images during device manufacturing. Models in excess of 90% accuracy are found to be consistently achieved by mitigating overfitting through reduced model complexity, image preprocessing, data augmentation, and examination of the intermediate layers of the convolutional neural networks. The results presented in this paper constitute an important milestone in automating the manufacture of atom-based qubits for computation and sensing applications.
RESUMEN
Spin-orbit interactions arise whenever the bulk inversion symmetry and/or structural inversion symmetry of a crystal is broken providing a bridge between a qubit's spin and orbital degree of freedom. While strong interactions can facilitate fast qubit operations by all-electrical control, they also provide a mechanism to couple charge noise thereby limiting qubit lifetimes. Previously believed to be negligible in bulk silicon, recent silicon nano-electronic devices have shown larger than bulk spin-orbit coupling strengths from Dresselhaus and Rashba couplings. Here, it is shown that with precision placement of phosphorus atoms in silicon along the [110] direction (without inversion symmetry) or [111] direction (with inversion symmetry), a wide range of Dresselhaus and Rashba coupling strength can be achieved from zero to 1113 × 10-13eV-cm. It is shown that with precision placement of phosphorus atoms, the local symmetry (C2v, D2d, and D3d) can be changed to engineer spin-orbit interactions. Since spin-orbit interactions affect both qubit operation and lifetimes, understanding their impact is essential for quantum processor design.
RESUMEN
We directly measure the band structure of a buried two dimensional electron gas (2DEG) using angle resolved photoemission spectroscopy. The buried 2DEG forms 2 nm beneath the surface of p-type silicon, because of a dense delta-type layer of phosphorus n-type dopants which have been placed there. The position of the phosphorous layer is beyond the probing depth of the photoemission experiment but the observation of the 2DEG is nevertheless possible at certain photon energies where emission from the states is resonantly enhanced. This permits direct access to the band structure of the 2DEG and its temperature dependence.