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1.
Small ; 17(45): e2103994, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34605163

RESUMEN

The emergence of interlayer excitons (IEs) from atomic layered transition metal dichalcogenides (TMDCs) heterostructures has drawn tremendous attention due to their unique and exotic optoelectronic properties. Coupling the IEs into optical cavities provides distinctive electromagnetic environments which plays an important role in controlling multiple optical processes such as optical nonlinear generation or photoluminescence enhancement. Here, the integration of IEs in TMDCs into plasmonic nanocavities based on a nanocube on a metallic mirror is reported. Spectroscopic studies reveal an order of magnitude enhancement of the IE at room temperature and a 5-time enhancement in fluorescence at cryogenic temperatures. Cavity modeling reveals that the enhancement of the emission is attributed to both increased excitation efficiency and Purcell effect from the cavity. The results show a novel method to control the excitonic processes in TMDC heterostructures to build high performance photonics and optoelectronics devices.

2.
Pract Neurol ; 21(3): 237-240, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33574114

RESUMEN

A 37-year-old woman developed progressive symmetrical weakness with areflexia, consistent with Guillain-Barré syndrome. After initially briefly responding to intravenous immunoglobulin, her weakness progressed markedly. Further investigation identified a new diagnosis of systemic lupus erythematosus with lupus nephritis. Following additional plasma exchange and corticosteroids, the lupus activity remitted and she made a complete neurological recovery.


Asunto(s)
Síndrome de Guillain-Barré , Lupus Eritematoso Sistémico , Adulto , Femenino , Síndrome de Guillain-Barré/complicaciones , Síndrome de Guillain-Barré/diagnóstico , Síndrome de Guillain-Barré/terapia , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnóstico , Intercambio Plasmático
3.
Nano Lett ; 19(8): 5417-5422, 2019 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-31264881

RESUMEN

Fluorescent nanoparticles with optically robust luminescence are imperative to applications in imaging and labeling. Here we demonstrate that hexagonal boron nitride (hBN) nanoparticles can be reliably produced using a scalable cryogenic exfoliation technique with sizes below 10 nm. The particles exhibit bright fluorescence generated by color centers that act as atomic-size quantum emitters. We analyze their optical properties, including emission wavelength, photon-statistics, and photodynamics, and show that they are suitable for far-field super-resolution fluorescence nanoscopy. Our results provide a foundation for exploration of hBN nanoparticles as candidates for bioimaging, labeling, as well as biomarkers that are suitable for quantum sensing.


Asunto(s)
Compuestos de Boro/química , Nanopartículas/química , Frío , Fluorescencia , Colorantes Fluorescentes/química , Nanopartículas/ultraestructura , Nanotecnología/métodos , Tamaño de la Partícula , Propiedades de Superficie
4.
Mol Biol Evol ; 30(5): 1188-95, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23418397

RESUMEN

Nonparametric bootstrap has been a widely used tool in phylogenetic analysis to assess the clade support of phylogenetic trees. However, with the rapidly growing amount of data, this task remains a computational bottleneck. Recently, approximation methods such as the RAxML rapid bootstrap (RBS) and the Shimodaira-Hasegawa-like approximate likelihood ratio test have been introduced to speed up the bootstrap. Here, we suggest an ultrafast bootstrap approximation approach (UFBoot) to compute the support of phylogenetic groups in maximum likelihood (ML) based trees. To achieve this, we combine the resampling estimated log-likelihood method with a simple but effective collection scheme of candidate trees. We also propose a stopping rule that assesses the convergence of branch support values to automatically determine when to stop collecting candidate trees. UFBoot achieves a median speed up of 3.1 (range: 0.66-33.3) to 10.2 (range: 1.32-41.4) compared with RAxML RBS for real DNA and amino acid alignments, respectively. Moreover, our extensive simulations show that UFBoot is robust against moderate model violations and the support values obtained appear to be relatively unbiased compared with the conservative standard bootstrap. This provides a more direct interpretation of the bootstrap support. We offer an efficient and easy-to-use software (available at http://www.cibiv.at/software/iqtree) to perform the UFBoot analysis with ML tree inference.


Asunto(s)
Funciones de Verosimilitud , Simulación por Computador , Filogenia
5.
J Clin Pathol ; 77(4): 219-224, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-37258250

RESUMEN

AIMS: To investigate trends in representation of women among authors and editorial boards of surgical pathology journals over the last two decades.Secondary aims: to identify barriers and potential solutions. METHODS: The names and gender of first, middle, last authors and editorial board members were obtained from original articles from seven pathology journals from various geopolitical regions in 2002, 2011 and 2021. The proportion of women first, middle, last authors and editorial board members were compared over time. RESULTS: 1097 publications and 8012 individual authors were extracted. In 2002, 2011 and 2021, respectively, the percentage of women first authors were 28.3% (257 of 907), 31.9% (566 of 1773) and 41.1% (1421 of 3457); women middle authorship rates were 30.0% (159 of 530), 32.8% (375 of 1145) and 40.9% (1067 of 2609) and women last authors were 18.0% (34 of 188), 26.0% (82 of 315) and 36.0% (152 of 422). Women representation on editorial boards has increased (11.3%, 15.8%, 26.5%), but of the chief editors, there was only one woman in 2021, while all were men in 2002 and 2011. CONCLUSIONS: To our knowledge, this study is the first to document under-representation of women among authors and editorial boards of surgical pathology journals. While women representation has increased over time, predominance of men remains relative to workforce proportions. Our findings are comparable to those from other medical fields and prompt the need to investigate the underlying causes for this imbalance and implement strategies to promote diversity, equity and inclusion in academic surgical pathology.


Asunto(s)
Patología Quirúrgica , Masculino , Humanos , Femenino , Autoria
6.
Micromachines (Basel) ; 15(7)2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-39064338

RESUMEN

Graphite is a versatile material used in various fields, particularly in the power source manufacturing industry. Nowadays, graphite holds a unique position in materials for anode electrodes in lithium-ion batteries. With a carbon content of over 99% being a requirement for graphite to serve as an electrode material, the graphite refinement process plays a pivotal role in the research and development of anode materials for lithium-ion batteries. This study used three different processes to purify spherical graphite through wet chemical methods. The spherical graphite after the purification processes was analysed for carbon content by using energy-dispersive X-ray (EDX) spectroscopy and was evaluated for structural and morphological characteristics through X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analyses. The analyses results indicate that the three-step process via H2SO4-NaOH-HCl cleaning can elevate the carbon content from 90% to above 99.9% while still maintaining the graphite structure and spherical morphology, thus enhancing the surface area of the material for anode application. Furthermore, the spherical graphite was studied for electrochemical properties when used as an anode for Li-ion batteries using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements. The results demonstrated that the purification process significantly improves the material's capacity with a specific capacity of 350 mAh/g compared to the 280 mAh/g capacity of the anode made of spherical graphite without purification.

7.
Mol Biol Evol ; 29(2): 663-73, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21940641

RESUMEN

Among the criteria to evaluate the performance of a phylogenetic method, robustness to model violation is of particular practical importance as complete a priori knowledge of evolutionary processes is typically unavailable. For studies of robustness in phylogenetic inference, a utility to add well-defined model violations to the simulated data would be helpful. We therefore introduce ImOSM, a tool to imbed intermittent evolution as model violation into an alignment. Intermittent evolution refers to extra substitutions occurring randomly on branches of a tree, thus changing alignment site patterns. This means that the extra substitutions are placed on the tree after the typical process of sequence evolution is completed. We then study the robustness of widely used phylogenetic methods: maximum likelihood (ML), maximum parsimony (MP), and a distance-based method (BIONJ) to various scenarios of model violation. Violation of rates across sites (RaS) heterogeneity and simultaneous violation of RaS and the transition/transversion ratio on two nonadjacent external branches hinder all the methods recovery of the true topology for a four-taxon tree. For an eight-taxon balanced tree, the violations cause each of the three methods to infer a different topology. Both ML and MP fail, whereas BIONJ, which calculates the distances based on the ML estimated parameters, reconstructs the true tree. Finally, we report that a test of model homogeneity and goodness of fit tests have enough power to detect such model violations. The outcome of the tests can help to actually gain confidence in the inferred trees. Therefore, we recommend using these tests in practical phylogenetic analyses.


Asunto(s)
Simulación por Computador , Modelos Genéticos , Modelos Teóricos , Filogenia , Algoritmos , Evolución Biológica , Evolución Molecular , Funciones de Verosimilitud
8.
Pathology ; 55(5): 596-609, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37330338

RESUMEN

Fusions involving the Neurotrophic tropomyosin receptor kinase (NTRK) gene family (NTRK1, NTRK2 and NTRK3) are targetable oncogenic alterations that are found in a diverse range of tumours. There is an increasing demand to identify tumours which harbour these fusions to enable treatment with selective tyrosine kinase inhibitors such as larotrectinib and entrectinib. NTRK fusions occur in a wide range of tumours including rare tumours such as infantile fibrosarcoma and secretory carcinomas of the salivary gland and breast, as well as at low frequencies in more common tumours including melanoma, colorectal, thyroid and lung carcinomas. Identifying NTRK fusions is a challenging task given the different genetic mechanisms underlying NTRK fusions, their varying frequency across different tumour types, complicated by other factors such as tissue availability, optimal detection methods, accessibility and costs of testing methods. Pathologists play a key role in navigating through these complexities by determining optimal approaches to NTRK testing which has important therapeutic and prognostic implications. This review provides an overview of tumours harbouring NTRK fusions, the importance of identifying these fusions, available testing methods including advantages and limitations, and generalised and tumour-specific approaches to testing.


Asunto(s)
Neoplasias de la Mama , Carcinoma , Neoplasias , Humanos , Femenino , Receptor trkA/genética , Patólogos , Proteínas de Fusión Oncogénica/genética , Neoplasias/genética , Neoplasias/patología , Fusión Génica
9.
Hum Pathol ; 138: 41-48, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37245628

RESUMEN

Cellular myofibromas/myopericytomas harboring recurring SRF fusions are recently characterized as rare and diagnostically challenging entities, which can mimic myogenic sarcomas. These tumors belong to the pericytic/perivascular myoid tumor family, which comprises a group of genetically heterogenous and sometimes morphologically overlapping entities. In this series, we describe 3 cases of SRF-rearranged cellular myofibromas/perivascular myoid tumors with a smooth muscle-like phenotype in children. The children ranged from 7 to 16 years of age, and all presented with a painless mass in the extremities, 2 of which were deep-seated. Histologically, the tumors demonstrated a smooth muscle-like morphology and immunophenotype with mild atypia and low-level mitotic activity. Prominent dense collagen deposition and coarse calcification was observed in 2 tumors. RNA sequencing revealed SRF fusions in all cases, with each tumor showing a different 3' partner gene, RELA, NFKBIE, and NCOA3. Of these, NCOA3 has not been reported previously, and this expands the molecular spectrum by identifying a novel fusion partner for SRF. Given that histological features can be worrisome for a myogenic sarcoma, wider awareness of this emerging tumor is valuable to avoid potential misclassification.


Asunto(s)
Miofibroma , Sarcoma , Neoplasias de los Tejidos Blandos , Humanos , Extremidades , Miofibroma/genética , Recurrencia Local de Neoplasia , Sarcoma/genética , Neoplasias de los Tejidos Blandos/genética
10.
Pathology ; 55(6): 760-771, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37573162

RESUMEN

While women pathologists have made up over one-third of pathologists in the Australian workforce for over 15 years and at least 50% since 2019, they are under-represented in senior leadership roles, scientific publications, grant recipients, editorial boards, key presentations, and professional awards. This is not unique to pathology and is seen in the broader medical and academic community. Barriers to gender equity and equality in pathology, medicine and academia include gender stereotypes, gender-based discrimination, structural and organisational barriers as well as broader social and cultural barriers. A diverse leadership reflective of the whole professional body and the broader community is important for optimal health outcomes. It is the responsibility and moral duty of individuals and organisations to address any gender disparities, inequities, and inequalities by monitoring, identifying, and acting on gender biases and systemic barriers that hinder appropriate levels of representation by women.


Asunto(s)
Equidad de Género , Sexismo , Femenino , Humanos , Australia , Recursos Humanos
11.
Mol Biol Evol ; 28(1): 143-52, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20643866

RESUMEN

As models of sequence evolution become more and more complicated, many criteria for model selection have been proposed, and tools are available to select the best model for an alignment under a particular criterion. However, in many instances the selected model fails to explain the data adequately as reflected by large deviations between observed pattern frequencies and the corresponding expectation. We present MISFITS, an approach to evaluate the goodness of fit (http://www.cibiv.at/software/misfits). MISFITS introduces a minimum number of "extra substitutions" on the inferred tree to provide a biologically motivated explanation why the alignment may deviate from expectation. These extra substitutions plus the evolutionary model then fully explain the alignment. We illustrate the method on several examples and then give a survey about the goodness of fit of the selected models to the alignments in the PANDIT database.


Asunto(s)
Algoritmos , Modelos Genéticos , Alineación de Secuencia/métodos , Análisis de Secuencia de Proteína/métodos , Programas Informáticos , Animales , Secuencia de Bases , ADN Mitocondrial/análisis , ADN Mitocondrial/genética , Bases de Datos Genéticas , Evolución Molecular , Humanos , Funciones de Verosimilitud , Datos de Secuencia Molecular , Filogenia , Primates/genética , Homología de Secuencia de Ácido Nucleico
12.
Radiol Case Rep ; 17(1): 142-146, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34820038

RESUMEN

Acute bilateral internal carotid occlusion was a very rare disease with a very poor prognosis. Clinical case reports according to the literature showed that mechanical thrombectomy was the most optimal treatment. We reported a clinical case of successful treatment with simultaneous thrombectomy in both occluded carotid arteries. A 62-year-old woman was admitted at our hospital within three hours of stroke onset secondary to an acute simultaneously bilateral carotid artery occlusion. On admission, her NIHSS (National Institutes of Health Stroke Scale) was 32. Non-contrast computed tomography right after that showed hyperacute infarction lesions in both hemispheres with right inferior temporal and insular cortex (Alberta Stroke Program Early CT Score - ASPECTS 8) and left putamen (ASPECTS 9). Her medical history included paroxysmal atrial fibrillation, prior ischemic stroke, pacemaker due to sick sinus syndrome. Her pre-stroke modified Rankin Scale score was 0 that she was fully recovered from previous stroke 4 months ago thanks to successful thrombectomy of the right internal carotid arteries (ICA). This time, the patient underwent again the simultaneous bilateral mechanical thrombectomy of both occluded ICA. The complete recanalization achieved on both sides with recanalization level of TICI-3 (thrombolysis in cerebral infarction) only in 38 mins after the groin puncture. She showed dramatic recovery and was discharged on day 28 with a Rankin Scale score of 2. Mechanical thrombectomy on bilateral ICA performed simultaneously will helps shorten the reperfusion time compared to the alternative one and thus, provides a better prognosis in acute ischemic stroke.

13.
Lancet Reg Health Southeast Asia ; 4: 100031, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35775040

RESUMEN

Background: Tackling the spread of COVID-19 remains a crucial part of ending the pandemic. Its highly contagious nature and constant evolution coupled with a relative lack of immunity make the virus difficult to control. For this, various strategies have been proposed and adopted including limiting contact, social isolation, vaccination, contact tracing, etc. However, given the heterogeneity in the enforcement of these strategies and constant fluctuations in the strictness levels of these strategies, it becomes challenging to assess the true impact of these strategies in controlling the spread of COVID-19. Methods: In the present study, we evaluated various transmission control measures that were imposed in 10 global urban cities and provinces in 2021- Bangkok, Gauteng, Ho Chi Minh City, Jakarta, London, Manila City, New Delhi, New York City, Singapore, and Tokyo. Findings: Based on our analysis, we herein propose the population-level Swiss cheese model for the failures and pitfalls in various strategies that each of these cities and provinces had. Furthermore, whilst all the evaluated cities and provinces took a different personalized approach to managing the pandemic, what remained common was dynamic enforcement and monitoring of breaches of each barrier of protection. The measures taken to reinforce the barriers were adjusted continuously based on the evolving epidemiological situation. Interpretation: How an individual city or province handled the pandemic profoundly affected and determined how the entire country handled the pandemic since the chain of transmission needs to be broken at the very grassroot level to achieve nationwide control. Funding: The present study did not receive any external funding.

14.
J Med Humanit ; 42(4): 603-625, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34779996

RESUMEN

INTRODUCTION: This study examines differences in students' perceived value of three artmaking modalities (poetry, comics, masks) and whether the resulting creative projects offer similar or different insights into medical students' professional identity formation. METHODS: Mixed-methods design using a student survey, student narrative comments and qualitative analysis of students' original work. RESULTS: Poetry and comics stimulated insight, but masks were more enjoyable and stress-reducing. All three art modalities expressed tension between personal and professional identities. DISCUSSION: Regardless of type of artmaking, students express concern about encroachments of training on personal identity but hoped that personal and professional selves could be integrated.


Asunto(s)
Educación de Pregrado en Medicina , Estudiantes de Medicina , Humanos , Máscaras , Narración , Identificación Social
15.
Environ Sci Process Impacts ; 23(10): 1458-1465, 2021 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-34546240

RESUMEN

The high proportion of unidentified extractable organofluorine (EOF) observed globally in humans and the environment indicates widespread occurrence of unknown per- and polyfluoroalkyl substances (PFAS). However, efforts to standardize or assess the reproducibility of EOF methods are currently lacking. Here we present the first EOF interlaboratory comparison in water and sludge. Three participants (four organizations) analyzed unfortified and PFAS-fortified ultrapure water, two unfortified groundwater samples, unfortified wastewater treatment plant effluent and sludge, and an unfortified groundwater extract. Participants adopted common sample handling strategies and target lists for EOF mass balance but used in-house combustion ion-chromatography (CIC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. EOF accuracy ranged from 85-101% and 76-109% for the 60 and 334 ng L-1 fluorine (F) - fortified water samples, respectively, with between-laboratory variation of 9-19%, and within-laboratory variation of 3-27%. In unfortified sludge and aqueous samples, between-laboratory variation ranged from 21-37%. The contribution from sum concentrations of 16 individual PFAS (∑PFAS-16) to EOF ranged from 2.2-60% but extended analysis showed that other targets were prevalent, in particular ultra-short-chain perfluoroalkyl acids (e.g. trifluoroacetic acid) in aqueous samples and perfluoroalkyl acid-precursors (e.g. polyfluoroalkyl phosphate diesters) in sludge. The EOF-CIC method demonstrated promising accuracy, robustness and reporting limits but poor extraction efficiency was observed for some targets (e.g. trifluoroacetic acid).


Asunto(s)
Fluorocarburos , Contaminantes Químicos del Agua , Cromatografía Liquida , Flúor , Fluorocarburos/análisis , Humanos , Reproducibilidad de los Resultados , Aguas del Alcantarillado , Espectrometría de Masas en Tándem , Agua , Contaminantes Químicos del Agua/análisis
16.
Environ Int ; 130: 104921, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31229872

RESUMEN

Consumer goods and building materials present in the preschool environment can be important sources of hazardous chemicals, such as plasticizers, bisphenols, organophosphorus and brominated flame retardants, poly- and perfluoroalkyl substances, which may pose a health risk to children. Even though exposure occurs via many different pathways, such as food intake, inhalation, dermal exposure, mouthing of toys etc., dust has been identified as a valuable indicator for indoor exposure. In the present study, we evaluate the efficiency of product substitution actions taken in 20 Swedish preschools from the Stockholm area to reduce the presence of hazardous substances in indoor environments. Dust samples were collected from elevated surfaces in rooms where children have their everyday activities, and the concentrations found were compared to the levels from a previous study conducted in 2015 at the same preschools. It was possible to lower levels of hazardous substances in dust, but their continued presence in the everyday environment of children was confirmed since bisphenol A, restricted phthalates and organophosphate esters were still detectable in all preschools. Also, an increase in the levels of some of the substitutes for the nowadays restricted substances was noted; some of the alternative plasticizers to phthalates, such as DEHA and DEHT, were found with increased concentrations. DINP was the dominant plasticizer in preschool dust with a median concentration of 389 µg/g, while its level was significantly (p = 0.012) higher at 716 µg/g in preschools with polyvinyl chloride (PVC) flooring. PBDEs were now less frequently detected in dust and their levels decreased 20% to 30%. This was one of the few times that PFAS were analyzed in preschool dust, where 6:2 diPAP was found to be most abundant with a median concentration of 1140 ng/g, followed by 6:2 PAP 151 ng/g, 8:2 diPAP 36 ng/g, N-Et-FOSAA 18 ng/g, PFOS 12 ng/g, PFOA 7.7 ng/g and PFNA 1.1 ng/g. In addition, fluorotelomer alcohols were detected in 65-90% of the samples. Children's exposure via dust ingestion was evaluated using intermediate and high daily intake rates of the targeted chemicals and established health limit values. In each case, the hazard quotients (HQs) were < 1, and the risk for children to have adverse health effects from the hazardous chemicals analyzed in this study via dust ingestion was even lower after the product substitution actions were taken in preschools.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Retardadores de Llama/análisis , Éteres Difenilos Halogenados/química , Sustancias Peligrosas/química , Organofosfatos/química , Instituciones Académicas , Contaminación del Aire Interior/análisis , Compuestos de Bencidrilo/química , Niño , Preescolar , Polvo/análisis , Monitoreo del Ambiente/métodos , Pisos y Cubiertas de Piso , Halogenación , Humanos , Fenoles/química , Ácidos Ftálicos , Plastificantes/química , Juego e Implementos de Juego , Suecia
17.
Sci Total Environ ; 625: 1046-1055, 2018 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-29996401

RESUMEN

Alternative flame retardants (FRs) have now replaced legacy FRs (such as polybrominated diphenyl ethers, PBDEs), but little is known about their fate in the aquatic environment. In this study, a range of legacy FRs (n=10) and alternative FRs, including halogenated FRs (HFRs, n=32) and organophosphorus FRs (OPFRs, n=19), were screened in water samples collected from 23 rivers covering the whole latitudinal range of Sweden. Of the 61 targeted FRs, 26 were detected in at least one of the river samples, with ΣFR concentrations ranging up to 170ngL-1 (mean 31±45ngL-1). In general, higher concentrations and a larger variety of FRs were detected in southern Sweden (ΣFR=60±56ngL-1) compared with the north (ΣFR=9.0±16ngL-1). In the south, HFRs were dominant, constituting on average 59% of ∑FRs, whereas in the north, OPFRs were dominant, constituting on average 82% of ∑FRs. This difference was best explained by higher population density in the south. The total daily flux of FRs into the Baltic Sea was estimated to be ~31kg and comprised mainly tetrabromobisphenol-A (TBBPA), 3,4,5,6-tetrabromophthalic anhydride (TEBP-Anh), and 2,4,6-tribromophenol (TBP). To the best of our knowledge, this is the first report of environmental occurrence of TEBP-Anh, which was detected in two rivers and is suggested to originate from airports located near the sampling sites.

18.
ACS Appl Mater Interfaces ; 10(29): 24886-24891, 2018 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-29882642

RESUMEN

Hexagonal boron nitride (hBN) mono and multilayers are promising hosts for room-temperature single photon emitters (SPEs). In this work we explore high-energy (∼MeV) electron irradiation as a means to generate stable SPEs in hBN. We investigate four types of exfoliated hBN flakes-namely, high-purity multilayers, isotopically pure hBN, carbon-rich hBN multilayers and monolayered material-and find that electron irradiation increases emitter concentrations dramatically in all samples. Furthermore, the engineered emitters are located throughout hBN flakes (not only at flake edges or grain boundaries) and do not require activation by high-temperature annealing of the host material after electron exposure. Our results provide important insights into controlled formation of hBN SPEs and may aid in identification of their crystallographic origin.

19.
Primates ; 58(3): 435-440, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28492971

RESUMEN

Following the split of the silvered langurs of Indochina into two species based on molecular and phenotypic data, there is a need to reevaluate their distribution and update their conservation status. Here, we report the distribution and assess the population size of Germain's langur (Trachypithecus germaini) within its known range across Vietnam. We confirmed this species at six of seven survey sites in different habitats within three provinces in the Mekong Delta Region, including semi-evergreen forest at the Seven Mountains of An Giang Province, mangrove forest in Ngoc Hien and Nam Can Districts and Melaleuca forest in U Minh Ha National Park of Ca Mau Province, and limestone forest at Kien Luong Karst Area and semi-evergreen and evergreen forests at Phu Quoc National Park of Kien Giang Province. We found no evidence of this species in Mui Ca Mau National Park, Ca Mau Province where it was previously reported. We conservatively estimate that the total population of Germain's langurs in Vietnam consists of 362-406 individuals, with the largest population found in the Kien Luong Karst Area. Hunting and habitat loss are severely impacting Germain's langur, resulting in the extirpation of the population in Mui Ca Mau National Park and small, isolated populations in the Seven Mountains and Ngoc Hien and Nam Can Districts. However, the ability of this species to inhabit a wide range of forest types, and its increasing population sizes in Phu Quoc National Park and Kien Luong Karst Area, provide signs of hope that continued conservation actions may help in its long-term survival.


Asunto(s)
Cercopithecidae , Colobinae , Conservación de los Recursos Naturales , Animales , Ecosistema , Bosques , Vietnam
20.
Health Behav Policy Rev ; 4(2): 118-128, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28798944

RESUMEN

OBJECTIVES: Interventions for colorectal cancer (CRC) prevention among black adults are needed. Connections between CRC screening non-adherence and other health risk behaviors may inform intervention development. METHODS: Associations between red meat (RM) and fruit and vegetable (FV) consumption, at-risk alcohol use, and CRC ever-screening were examined using adjusted logistic regressions among 520 church-going black adults in Houston, Texas, aged >50. RESULTS: In the final adjusted model, being younger, uninsured, eating more RM and engaging in at-risk alcohol use were associated with lower likelihood of CRC ever-screening. CONCLUSIONS: Church-based interventions to increase CRC screening among black adults might capitalize on associations with RM consumption and alcohol use behaviors as part of a broader wellness promotion initiative.

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