Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 93
Filtrar
1.
Nat Mater ; 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654140

RESUMO

Single-photon emitters serve as building blocks for many emerging concepts in quantum photonics. The recent identification of bright, tunable and stable emitters in hexagonal boron nitride (hBN) has opened the door to quantum platforms operating across the infrared to ultraviolet spectrum. Although it is widely acknowledged that defects are responsible for single-photon emitters in hBN, crucial details regarding their origin, electronic levels and orbital involvement remain unknown. Here we employ a combination of resonant inelastic X-ray scattering and photoluminescence spectroscopy in defective hBN, unveiling an elementary excitation at 285 meV that gives rise to a plethora of harmonics correlated with single-photon emitters. We discuss the importance of N π* anti-bonding orbitals in shaping the electronic states of the emitters. The discovery of elementary excitations in hBN provides fundamental insights into quantum emission in low-dimensional materials, paving the way for future investigations in other platforms.

2.
Neurology ; 102(5): e209138, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38354325

RESUMO

BACKGROUND AND OBJECTIVES: Cardiovascular disease contributes significantly to disease burden among many Indigenous populations. However, data on stroke incidence in Indigenous populations are sparse. We aimed to investigate what is known of stroke incidence in Indigenous populations of countries with a very high Human Development Index (HDI), locating the research in the broader context of Indigenous health. METHODS: We identified population-based stroke incidence studies published between 1990 and 2022 among Indigenous adult populations of developed countries using PubMed, Embase, and Global Health databases, without language restriction. We excluded non-peer-reviewed sources, studies with fewer than 10 Indigenous people, or not covering a 35- to 64-year minimum age range. Two reviewers independently screened titles, abstracts, and full-text articles and extracted data. We assessed quality using "gold standard" criteria for population-based stroke incidence studies, the Newcastle-Ottawa Scale for risk of bias, and CONSIDER criteria for reporting of Indigenous health research. An Indigenous Advisory Board provided oversight for the study. RESULTS: From 13,041 publications screened, 24 studies (19 full-text articles, 5 abstracts) from 7 countries met the inclusion criteria. Age-standardized stroke incidence rate ratios were greater in Aboriginal and Torres Strait Islander Australians (1.7-3.2), American Indians (1.2), Sámi of Sweden/Norway (1.08-2.14), and Singaporean Malay (1.7-1.9), compared with respective non-Indigenous populations. Studies had substantial heterogeneity in design and risk of bias. Attack rates, male-female rate ratios, and time trends are reported where available. Few investigators reported Indigenous stakeholder involvement, with few studies meeting any of the CONSIDER criteria for research among Indigenous populations. DISCUSSION: In countries with a very high HDI, there are notable, albeit varying, disparities in stroke incidence between Indigenous and non-Indigenous populations, although there are gaps in data availability and quality. A greater understanding of stroke incidence is imperative for informing effective societal responses to socioeconomic and health disparities in these populations. Future studies into stroke incidence in Indigenous populations should be designed and conducted with Indigenous oversight and governance to facilitate improved outcomes and capacity building. REGISTRATION INFORMATION: PROSPERO registration: CRD42021242367.


Assuntos
Povos Indígenas , Acidente Vascular Cerebral , Adulto , Feminino , Humanos , Masculino , Incidência , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etnologia , Pessoa de Meia-Idade , Países Desenvolvidos
3.
J Biol Chem ; 300(1): 105465, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37979915

RESUMO

Calreticulin (CRT) was originally identified as a key calcium-binding protein of the endoplasmic reticulum. Subsequently, CRT was shown to possess multiple intracellular functions, including roles in calcium homeostasis and protein folding. Recently, several extracellular functions have been identified for CRT, including roles in cancer cell invasion and phagocytosis of apoptotic and cancer cells by macrophages. In the current report, we uncover a novel function for extracellular CRT and report that CRT functions as a plasminogen-binding receptor that regulates the conversion of plasminogen to plasmin. We show that human recombinant or bovine tissue-derived CRT dramatically stimulated the conversion of plasminogen to plasmin by tissue plasminogen activator or urokinase-type plasminogen activator. Surface plasmon resonance analysis revealed that CRT-bound plasminogen (KD = 1.8 µM) with moderate affinity. Plasminogen binding and activation by CRT were inhibited by ε-aminocaproic acid, suggesting that an internal lysine residue of CRT interacts with plasminogen. We subsequently show that clinically relevant CRT variants (lacking four or eight lysines in carboxyl-terminal region) exhibited decreased plasminogen activation. Furthermore, CRT-deficient fibroblasts generated 90% less plasmin and CRT-depleted MDA MB 231 cells also demonstrated a significant reduction in plasmin generation. Moreover, treatment of fibroblasts with mitoxantrone dramatically stimulated plasmin generation by WT but not CRT-deficient fibroblasts. Our results suggest that CRT is an important cellular plasminogen regulatory protein. Given that CRT can empower cells with plasmin proteolytic activity, this discovery may provide new mechanistic insight into the established role of CRT in cancer.


Assuntos
Calreticulina , Plasminogênio , Animais , Bovinos , Humanos , Calreticulina/genética , Calreticulina/isolamento & purificação , Calreticulina/metabolismo , Fibrinolisina/metabolismo , Plasminogênio/genética , Plasminogênio/metabolismo , Ativador de Plasminogênio Tecidual/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Domínios Proteicos/genética , Mutação , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Técnicas de Inativação de Genes , Linhagem Celular Tumoral , Neoplasias/fisiopatologia
4.
Nat Commun ; 14(1): 3712, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37349290

RESUMO

The growing field of quantum information technology requires propagation of information over long distances with efficient readout mechanisms. Excitonic quantum fluids have emerged as a powerful platform for this task due to their straightforward electro-optical conversion. In two-dimensional transition metal dichalcogenides, the coupling between spin and valley provides exciting opportunities for harnessing, manipulating, and storing bits of information. However, the large inhomogeneity of single layers cannot be overcome by the properties of bright excitons, hindering spin-valley transport. Nonetheless, the rich band structure supports dark excitonic states with strong binding energy and longer lifetime, ideally suited for long-range transport. Here we show that dark excitons can diffuse over several micrometers and prove that this repulsion-driven propagation is robust across non-uniform samples. The long-range propagation of dark states with an optical readout mediated by chiral phonons provides a new concept of excitonic devices for applications in both classical and quantum information technology.


Assuntos
Ciência da Informação , Fônons , Tecnologia da Informação , Meio Ambiente , Semicondutores
5.
PLoS One ; 18(4): e0284302, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37036881

RESUMO

BACKGROUND: Family and domestic violence, encompassing diverse behaviours including physical, sexual, emotional and financial abuse, is endemic worldwide and has multiple adverse health and social consequences. Principal drivers include traditional gender values that disempower women. Changing these is a key prevention strategy. In Australia, high-quality national surveys provide data on public perspectives concerning family and domestic violence but may not capture community-level diversity. As part of a project for primary prevention family and domestic violence in outer regional Australia, our aims were to develop and administer a questionnaire-based survey suitable for the local community encompassing knowledge about, attitudes towards, and personal experiences of family and domestic violence, to describe and to investigate the theoretical (factor) structure and local socio-demographic predictors of responses, and to determine the extent to which the survey findings are locally distinctive. METHODS: The online community survey for local residents (≥15 years), comprised items on respondents' sociodemographic characteristics plus questions abridged from pre-existing national instruments on knowledge about, attitudes towards, and personal experiences of family and domestic violence. Responses were rake-weighted to correct census-ascertained sample imbalance and investigated using exploratory factor analysis, with sociodemographic predictors determined using multiple linear regression and dominance analysis. RESULTS: Among 914 respondents, males (27.0%), those from age-group extremes, and less-educated persons were underrepresented. Familiarity with diverse family and domestic violence behaviours was high among all subgroups. Poorer knowledge of the FDV behaviour continuum and attitudes supporting traditional gender roles and FDV were disproportionately evident among males, older respondents and those with lower education levels. Both the factor structure of extracted composite measures reflecting community perspectives and sociodemographic predictors of responses generally aligned with patterns evident in national data. CONCLUSIONS: Local reinforcement of existing nationwide findings on community understanding of and attitudes towards family and domestic violence provides salience for targeted interventions.


Assuntos
Violência Doméstica , Masculino , Humanos , Feminino , Austrália , Identidade de Gênero , Inquéritos e Questionários , Comportamento Sexual
6.
Transplant Cell Ther ; 29(2): 95.e1-95.e10, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36402456

RESUMO

Despite the readily available graft sources for allogeneic hematopoietic cell transplantation (alloHCT), a significant unmet need remains in the timely provision of suitable unrelated donor grafts. This shortage is related to the rarity of certain HLA alleles in the donor pool, nonclearance of donors owing to infectious disease or general health status, and prolonged graft procurement and processing times. An alternative hematopoietic progenitor cell (HPC) graft source obtained from the vertebral bodies (VBs) of deceased organ donors could alleviate many of the obstacles associated with using grafts from healthy living donors or umbilical cord blood (UCB). Deceased organ donor-derived bone marrow (BM) can be preemptively screened, cryogenically banked for on-demand use, and made available in adequate cell doses for HCT. We have developed a good manufacturing practice (GMP)-compliant process to recover and cryogenically bank VB-derived HPCs from deceased organ donor (OD) BM. Here we present results from an analysis of HPCs from BM obtained from 250 deceased donors to identify any substantial difference in composition or quality compared with HPCs from BM aspirated from the iliac crests of healthy living donors. BM from deceased donor VBs was processed in a central GMP facility and packaged for cryopreservation in 5% DMSO/2.5% human serum albumin. BM aspirated from living donor iliac crests was obtained and used for comparison. A portion of each specimen was analyzed before and after cryopreservation by flow cytometry and colony-forming unit potential. Bone marrow chimerism potential was assessed in irradiated immunocompromised NSG mice. Analysis of variance with Bonferroni correction for multiple comparisons was used to determine how cryopreservation affects BM cells and to evaluate indicators of successful engraftment of BM cells into irradiated murine models. The t test (with 95% confidence intervals [CIs]) was used to compare cells from deceased donors and living donors. A final dataset of complete clinical and matched laboratory data from 226 cryopreserved samples was used in linear regressions to predict outcomes of BM HPC processing. When compared before and after cryopreservation, OD-derived BM HPCs were found to be stable, with CD34+ cells maintaining high viability and function after thawing. The yield from a single donor is sufficient for transplantation of an average of 1.6 patients (range, 1.2 to 7.5). CD34+ cells from OD-derived HPCs from BM productively engrafted sublethally irradiated immunocompromised mouse BM (>44% and >67% chimerism at 8 and 16 weeks, respectively). Flow cytometry and secondary transplantation confirmed that OD HPCs from BM is composed of long-term engrafting CD34+CD38-CD45RA-CD90+CD49f+ HSCs. Linear regression identified no meaningful predictive associations between selected donor-related characteristics and OD BM HPC quality or yield. Collectively, these data demonstrate that cryopreserved BM HPCs from deceased organ donors is potent and functionally equivalent to living donor BM HPCs and is a viable on-demand graft source for clinical HCT. Prospective clinical trials will soon commence in collaboration with the Center for International Blood and Marrow Research to assess the feasibility, safety, and efficacy of Ossium HPCs from BM (ClinicalTrials.gov identifier NCT05068401).


Assuntos
Medula Óssea , Transplante de Células-Tronco Hematopoéticas , Humanos , Animais , Camundongos , Estudos Prospectivos , Transplante de Células-Tronco Hematopoéticas/métodos , Criopreservação/métodos , Doadores Vivos
8.
Adv Mater ; 34(24): e2200861, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35488783

RESUMO

The Weyl semimetal WTe2 has shown several correlated electronic behaviors, such as the quantum spin Hall effect, superconductivity, ferroelectricity, and a possible exciton insulator state, all of which can be tuned by various physical and chemical approaches. Here, a new electronic phase in WTe2 induced by lithium intercalation is discovered. The new phase exhibits an increasing resistivity with decreasing temperature and its carrier density is almost two orders of magnitude lower than the carrier density of the semimetallic Td phase, probed by in situ Hall measurements as a function of lithium intercalation. The theoretical calculations predict the new lithiated phase to be a potential charge density wave (CDW) phase with a bandgap of ≈0.14 eV, in good agreement with the in situ transport data. The new phase is structurally distinct from the initial Td phase, characterized by polarization-angle-dependent Raman spectroscopy, and large lattice distortions close to 6% are predicted in the new phase. This finding of a new gapped phase in a 2D semimetal demonstrates electrochemical intercalation as a powerful tuning knob for modulating electron density and phase stability in 2D materials.

9.
Nano Lett ; 22(7): 3087-3094, 2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35290068

RESUMO

Transition-metal dichalcogenides (TMDs) are layered materials that have a semiconducting phase with many advantageous optoelectronic properties, including tightly bound excitons and spin-valley locking. In tungsten-based TMDs, spin- and momentum-forbidden transitions give rise to dark excitons that typically are optically inaccessible but represent the lowest excitonic states of the system. Dark excitons can deeply affect the transport, dynamics, and coherence of bright excitons, hampering device performance. Therefore, it is crucial to create conditions in which these excitonic states can be visualized and controlled. Here, we show that compressive strain in WS2 enables phonon scattering of photoexcited electrons between momentum valleys, enhancing the formation of dark intervalley excitons. We show that the emission and spectral properties of momentum-forbidden excitons are accessible and strongly depend on the local strain environment that modifies the band alignment. This mechanism is further exploited for strain sensing in two-dimensional semiconductors, revealing a gauge factor exceeding 104.


Assuntos
Semicondutores , Elementos de Transição , Movimento (Física) , Fônons , Tungstênio
10.
Development ; 148(23)2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34738614

RESUMO

Autosomal dominant PDGFRß gain-of-function mutations in mice and humans cause a spectrum of wasting and overgrowth disorders afflicting the skeleton and other connective tissues, but the cellular origin of these disorders remains unknown. We demonstrate that skeletal stem cells (SSCs) isolated from mice with a gain-of-function D849V point mutation in PDGFRß exhibit colony formation defects that parallel the wasting or overgrowth phenotypes of the mice. Single-cell RNA transcriptomics with SSC-derived polyclonal colonies demonstrates alterations in osteogenic and chondrogenic precursors caused by PDGFRßD849V. Mutant cells undergo poor osteogenesis in vitro with increased expression of Sox9 and other chondrogenic markers. Mice with PDGFRßD849V exhibit osteopenia. Increased STAT5 phosphorylation and overexpression of Igf1 and Socs2 in PDGFRßD849V cells suggests that overgrowth in mice involves PDGFRßD849V activating the STAT5-IGF1 axis locally in the skeleton. Our study establishes that PDGFRßD849V causes osteopenic skeletal phenotypes that are associated with intrinsic changes in SSCs, promoting chondrogenesis over osteogenesis.


Assuntos
Mutação com Ganho de Função , Mioblastos Esqueléticos/metabolismo , Mutação Puntual , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Substituição de Aminoácidos , Animais , Condrogênese/genética , Regulação da Expressão Gênica , Camundongos , Camundongos Transgênicos , Mioblastos Esqueléticos/patologia , Osteogênese/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Transdução de Sinais/genética
11.
Cell Stem Cell ; 28(6): 989-990, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34087159

RESUMO

Specific cell targeting with one site-specific recombinase is challenging. In this issue of Cell Stem Cell, Han et al. (2021) released a collection of Dre drivers and demonstrate how two recombinases can be combined to improve the cell specificity of lineage tracing and gene inactivation in mice.


Assuntos
Integrases , Recombinases , Animais , Sequência de Bases , Movimento Celular , Integrases/metabolismo , Camundongos , Recombinases/genética , Recombinases/metabolismo
13.
PLoS One ; 16(6): e0252701, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34143817

RESUMO

Previous research indicates that patient self-measured blood pressure (SMBP) is a cost-effective strategy for improving hypertension (HTN) diagnosis and control. However, it is unknown which specific uses of SMBP produce the most value. Our goal is to estimate, from an insurance perspective, the return-on-investment (ROI) and net present value associated with coverage of SMBP devices when used (a) only to diagnose HTN, (b) only to select and titrate medication, (c) only to monitor HTN treatment, or (d) as a bundle with all three uses combined. We employed national sample of claims data, Framingham risk predictions, and published sensitivity-specificity values of SMBP and clinic blood-pressure measurement to extend a previously-developed local decision-analytic simulation model. We then used the extended model to determine which uses of SMBP produce the most economic value when scaled to the U.S. adult population. We found that coverage of SMBP devices yielded positive ROIs for insurers in the short-run and at lifetime horizon when the three uses of SMBP were considered together. When each use was evaluated separately, positive returns were seen when SMBP was used for diagnosis or for medication selection and titration. However, returns were negative when SMBP was used exclusively to monitor HTN treatment. When scaled to the U.S. population, adoption of SMBP would prevent nearly 16.5 million false positive HTN diagnoses, thereby improving quality of care while saving insurance plans $254 per member. A strong economic case exists for insurers to cover the cost of SMBP devices, but it matters how devices are used.


Assuntos
Determinação da Pressão Arterial/métodos , Pressão Sanguínea/fisiologia , Hipertensão/prevenção & controle , Autocuidado/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Determinação da Pressão Arterial/economia , Análise Custo-Benefício , Humanos , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Pessoa de Meia-Idade , Modelos Econômicos , Autocuidado/economia , Sensibilidade e Especificidade
14.
Front Neurol ; 12: 661570, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33967945

RESUMO

Background and Aims: Despite known Indigenous health and socioeconomic disadvantage in countries with a Very High Human Development Index, data on the incidence of stroke in these populations are sparse. With oversight from an Indigenous Advisory Board, we will undertake a systematic review of the incidence of stroke in Indigenous populations of developed countries or regions, with comparisons between Indigenous and non-Indigenous populations of the same region, though not between different Indigenous populations. Methods: Using PubMed, OVID-EMBASE, and Global Health databases, we will examine population-based incidence studies of stroke in Indigenous adult populations of developed countries published 1990-current, without language restriction. Non-peer-reviewed sources, studies including <10 Indigenous People, or with insufficient data to determine incidence, will be excluded. Two reviewers will independently validate the search strategies, screen titles and abstracts, and record reasons for rejection. Relevant articles will undergo full-text screening, with standard data extracted for all studies included. Quality assessment will include Sudlow and Warlow's criteria for population-based stroke incidence studies, the Newcastle-Ottawa Scale for risk of bias, and the CONSIDER checklist for Indigenous research. Results: Primary outcomes include crude, age-specific and/or age-standardized incidence of stroke. Secondary outcomes include overall stroke rates, incidence rate ratio and case-fatality. Results will be synthesized in figures and tables, describing data sources, populations, methodology, and findings. Within-population meta-analysis will be performed if, and where, methodologically sound and comparable studies allow this. Conclusion: We will undertake the first systematic review assessing disparities in stroke incidence in Indigenous populations of developed countries. Data outputs will be disseminated to relevant Indigenous stakeholders to inform public health and policy research.

15.
BMJ Open ; 11(3): e042268, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727263

RESUMO

OBJECTIVES: Anticipation and prompt relief of symptoms among patients with a life-limiting illness is a core element of palliative care. Indigenous Australians commonly encounter cultural barriers in healthcare that may impair outcomes. The Palliative Care Outcomes Collaboration collects patient care data for the purposes of continuous quality improvement and benchmarking, with each recorded care episode divided into phases that reflect a patient's condition. We aimed to investigate differences between Indigenous and non-Indigenous patients in the occurrence and duration of 'unstable' phases (which indicate unanticipated deterioration in a patient's condition or circumstances), and determine attainment of the relevant benchmark (resolution of unstable phases in ≤3 days in 90% of cases) for both groups. DESIGN: Cohort study. SETTING: Australia-wide hospital-based and community-based specialist palliative care (1 January 2010 to 30 June 2015). PARTICIPANTS: 139 556 (1502 Indigenous and 138 054 non-Indigenous) adult patients. OUTCOME MEASURES: Indigenous and non-Indigenous patients were compared on (1) the risk of a phase being categorised as unstable, (2) the duration of unstable phases, and (3) the risk of unstable phases being prolonged (>3 days). Crude and adjusted estimates were produced from three-level robust Poisson regression and complementary log-log discrete time survival models. RESULTS: Unstable phases occurred with similar frequency overall among Indigenous and non-Indigenous patients (adjusted relative risks 1.06; 95% CI 1.00 to 1.11; not significant after correction for multiple comparisons). The duration and risk of prolongation of unstable phases were similar in both patient groups, with no significant differences evident among subgroups. The benchmark was not met for either Indigenous or non-Indigenous patients (unstable phase duration >3 days in 24.3% vs 25.5%; p=0.398). CONCLUSIONS: Despite well-documented shortcomings of healthcare for Indigenous Australians, there is no clear evidence of greater occurrence or prolongation of unanticipated problems among Indigenous patients accessing specialist palliative care services in hospital or the community.


Assuntos
Serviços de Saúde do Indígena , Cuidados Paliativos , Adulto , Austrália , Estudos de Coortes , Humanos , Havaiano Nativo ou Outro Ilhéu do Pacífico
16.
ACS Appl Mater Interfaces ; 13(8): 10603-10611, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33596044

RESUMO

The intercalation-induced phase transition of MoS2 from the semiconducting 2H to the semimetallic 1T' phase has been studied in detail for nearly a decade; however, the effects of a heterointerface between MoS2 and other two-dimensional (2D) crystals on the phase transition have largely been overlooked. Here, ab initio calculations show that intercalating Li at a MoS2-hexagonal boron nitride (hBN) interface stabilizes the 1T phase over the 2H phase of MoS2 by ∼100 mJ m -2, suggesting that encapsulating MoS2 with hBN may lower the electrochemical energy needed for the intercalation-induced phase transition. However, in situ Raman spectroscopy of hBN-MoS2-hBN heterostructures during the electrochemical intercalation of Li+ shows that the phase transition occurs at the same applied voltage for the heterostructure as for bare MoS2. We hypothesize that the predicted thermodynamic stabilization of the 1T'-MoS2-hBN interface is counteracted by an energy barrier to the phase transition imposed by the steric hindrance of the heterointerface. The phase transition occurs at lower applied voltages upon heating the heterostructure, which supports our hypothesis. Our study highlights that interfacial effects of 2D heterostructures can go beyond modulating electrical properties and can modify electrochemical and phase transition behaviors.

17.
Health Inf Manag ; 50(1-2): 64-75, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32216561

RESUMO

BACKGROUND: Data quality is fundamental to the integrity of quantitative research. The role of external researchers in data quality assessment (DQA) remains ill-defined in the context of secondary use for research of large, centrally curated health datasets. In order to investigate equity of palliative care provided to Indigenous Australian patients, researchers accessed a now-historical version of a national palliative care dataset developed primarily for the purpose of continuous quality improvement. OBJECTIVES: (i) To apply a generic DQA framework to the dataset and (ii) to report the process and results of this assessment and examine the consequences for conducting the research. METHOD: The data were systematically examined for completeness, consistency and credibility. Data quality issues relevant to the Indigenous identifier and framing of research questions were of particular interest. RESULTS: The dataset comprised 477,518 records of 144,951 patients (Indigenous N = 1515; missing Indigenous identifier N = 4998) collected from participating specialist palliative care services during a period (1 January 2010-30 June 2015) in which data-checking systems underwent substantial upgrades. Progressive improvement in completeness of data over the study period was evident. The data were error-free with respect to many credibility and consistency checks, with anomalies detected reported to data managers. As the proportion of missing values remained substantial for some clinical care variables, multiple imputation procedures were used in subsequent analyses. CONCLUSION AND IMPLICATIONS: In secondary use of large curated datasets, DQA by external researchers may both influence proposed analytical methods and contribute to improvement of data curation processes through feedback to data managers.


Assuntos
Confiabilidade dos Dados , Conjuntos de Dados como Assunto/normas , Havaiano Nativo ou Outro Ilhéu do Pacífico , Cuidados Paliativos , Austrália , Disparidades em Assistência à Saúde , Humanos
18.
ACS Nano ; 15(1): 410-418, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33211473

RESUMO

Owing to the small energy differences between its polymorphs, MoTe2 can access a full spectrum of electronic states from the 2H semiconducting state to the 1T' semimetallic state and from the Td Weyl semimetallic state to the superconducting state in the 1T' and Td phase at low temperature. Thus, it is a model system for phase transformation studies as well as quantum phenomena such as the quantum spin Hall effect and topological superconductivity. Careful studies of MoTe2 and its potential applications require large-area MoTe2 thin films with high crystallinity and thickness control. Here, we present cm2-scale synthesis of 2H-MoTe2 thin films with layer control and large grains that span several microns. Layer control is achieved by controlling the initial thickness of the precursor MoOx thin films, which are deposited on sapphire substrates by atomic layer deposition and subsequently tellurized. Despite the van der Waals epitaxy, the precursor-substrate interface is found to critically determine the uniformity in thickness and grain size of the resulting MoTe2 films: MoTe2 grown on sapphire show uniform films while MoTe2 grown on amorphous SiO2 substrates form islands. This synthesis strategy decouples the layer control from the variabilities of growth conditions for robust growth results and is applicable to growing other transition-metal dichalcogenides with layer control.

19.
J Transl Med ; 18(1): 300, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32758261

RESUMO

BACKGROUND: Deceased organ donors represent an untapped source of therapeutic bone marrow (BM) that can be recovered in 3-5 times the volume of that obtained from living donors, tested for quality, cryopreserved, and banked indefinitely for future on-demand use. A challenge for a future BM banking system will be to manage the prolonged ischemia times that are inevitable when bones procured at geographically-dispersed locations are shipped to distant facilities for processing. Our objectives were to: (a) quantify, under realistic field conditions, the relationship between ischemia time and the quality of hematopoietic stem and progenitor cells (HSPCs) derived from deceased-donor BM; (b) identify ischemia-time boundaries beyond which HSPC quality is adversely affected; (c) investigate whole-body cooling as a strategy for preserving cell quality; and (d) investigate processing experience as a variable affecting quality. METHODS: Seventy-five bones from 62 donors were analyzed for CD34+ viability following their exposure to various periods of warm-ischemia time (WIT), cold-ischemia time (CIT), and body-cooling time (BCT). Regression models were developed to quantify the independent associations of WIT, CIT, and BCT, with the viability and function of recovered HSPCs. RESULTS: Results demonstrate that under "real-world" scenarios: (a) combinations of warm- and cold-ischemia times favorable to the recovery of high-quality HSPCs are achievable (e.g., CD34+ cell viabilities in the range of 80-90% were commonly observed); (b) body cooling prior to bone recovery is detrimental to cell viability (e.g., CD34+ viability < 73% with, vs. > 89% without body cooling); (c) vertebral bodies (VBs) are a superior source of HSPCs compared to ilia (IL) (e.g., %CD34+ viability > 80% when VBs were the source, vs. < 74% when IL were the source); and (d) processing experience is a critical variable affecting quality. CONCLUSIONS: Our models can be used by an emerging BM banking system to formulate ischemia-time tolerance limits and data-driven HSPC quality-acceptance standards.


Assuntos
Medula Óssea , Doadores de Tecidos , Antígenos CD34 , Células da Medula Óssea , Transplante de Medula Óssea , Células-Tronco Hematopoéticas , Humanos , Isquemia
20.
Artigo em Inglês | MEDLINE | ID: mdl-32365883

RESUMO

Symptom relief is fundamental to palliative care. Aboriginal and Torres Strait Islander (Indigenous) Australians are known to experience inequities in health care delivery and outcomes, but large-scale studies of end-of-life symptoms in this population are lacking. We compared symptom-related distress among Indigenous and non-Indigenous Australian patients in specialist palliative care using the multi-jurisdictional Palliative Care Outcomes Collaboration dataset. Based on patient-reported rating scale responses, adjusted relative risks (aRRs) stratified by care setting were calculated for occurrence of (i) symptom-related moderate-to-severe distress and worsening distress during a first episode of care and (ii) symptom-related moderate-to-severe distress at the final pre-death assessment. The p-value significance threshold was corrected for multiple comparisons. First-episode frequencies of symptom-related distress were similar among Indigenous (n = 1180) and non-Indigenous (n = 107,952) patients in both inpatient and community settings. In final pre-death assessments (681 Indigenous and 67,339 non-Indigenous patients), both groups had similar occurrence of moderate-to-severe distress when care was provided in hospital. In community settings, Indigenous compared with non-Indigenous patients had lower pre-death risks of moderate-to-severe distress from overall symptom occurrence (aRR 0.78; p = 0.001; confidence interval [CI] 0.67-0.91). These findings provide reassurance of reasonable equivalence of end-of-life outcomes for Indigenous patients who have been accepted for specialist palliative care.


Assuntos
Disparidades em Assistência à Saúde , Cuidados Paliativos , Estresse Psicológico , Assistência Terminal , Adulto , Idoso , Austrália , Atenção à Saúde , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Havaiano Nativo ou Outro Ilhéu do Pacífico , Estresse Psicológico/etnologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA