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1.
AIDS Behav ; 19(8): 1478-90, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25863467

RESUMO

African Americans face disproportionate sexually transmitted infection including HIV (STI/HIV), with those passing through a correctional facility at heightened risk. There is a need to identify modifiable STI/HIV risk factors among incarcerated African Americans. Project DISRUPT is a cohort study of incarcerated African American men recruited from September 2011 through January 2014 from prisons in North Carolina who were in committed partnerships with women at prison entry (N = 207). During the baseline (in-prison) study visit, participants responded to a risk behavior survey and provided a urine specimen, which was tested for STIs. Substantial proportions reported multiple partnerships (42 %), concurrent partnerships (33 %), and buying sex (11 %) in the 6 months before incarceration, and 9 % tested positive for an STI at baseline (chlamydia: 5.3 %, gonorrhea: 0.5 %, trichomoniasis: 4.9 %). Poverty and depression appeared to be strongly associated with sexual risk behaviors. Substance use was linked to prevalent STI, with binge drinking the strongest independent risk factor (adjusted odds ratio: 3.79, 95 % CI 1.19-12.04). There is a continued need for improved prison-based STI testing, treatment, and prevention education as well as mental health and substance use diagnosis.


Assuntos
Negro ou Afro-Americano/psicologia , Infecções por HIV/epidemiologia , Transtornos do Humor/psicologia , Pobreza , Prisioneiros , Infecções Sexualmente Transmissíveis/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adulto , Estudos Transversais , Infecções por HIV/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , North Carolina/epidemiologia , Prevalência , Prisioneiros/estatística & dados numéricos , Prisões , Fatores de Risco , Assunção de Riscos , Comportamento Sexual/estatística & dados numéricos , Parceiros Sexuais , Infecções Sexualmente Transmissíveis/psicologia , Sexo sem Proteção/estatística & dados numéricos
2.
Heliyon ; 10(4): e26144, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38390105

RESUMO

Within various unstructured industrial environments, there is often the requirement to conduct remote engineering tasks, such as sampling the structure for analysis prior to decommissioning. Most existing tools are simply not dexterous enough to fulfil this task, and thus new technology is required. We describe here a simple, lightweight, and water-resistant collaborative dual-arm continuum robot system which can aid in this task. To improve the kinematic accuracy of the system, a class of flexible hinges have been combined with a conventional continuum robot configuration. The thickness and width of said flexible hinges can be adjusted to adapt to various tasks. Kinematic and stiffness models have further been developed, incorporating the influence of these flexible hinges. A set of experiments have been conducted to validate the proposed model and demonstrate the advantages of the platform. It was found that the kinematic accuracy of the continuum robot can be improved by a factor of around 10 with the aid of said hinges.

3.
Nat Genet ; 21(3): 271-7, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10080178

RESUMO

Darier disease (DD) is an autosomal-dominant skin disorder characterized by loss of adhesion between epidermal cells (acantholysis) and abnormal keratinization. Recently we constructed a 2.4-Mb, P1-derived artificial chromosome contig spanning the DD candidate region on chromosome 12q23-24.1. After screening several genes that mapped to this region, we identified mutations in the ATP2A2 gene, which encodes the sarco/endoplasmic reticulum Ca2(+)-ATPase type 2 isoform (SERCA2) and is highly expressed in keratinocytes. Thirteen mutations were identified, including frameshift deletions, in-frame deletions or insertions, splice-site mutations and non-conservative missense mutations in functional domains. Our results demonstrate that mutations in ATP2A2 cause DD and disclose a role for this pump in a Ca(2+)-signalling pathway regulating cell-to-cell adhesion and differentiation of the epidermis.


Assuntos
ATPases Transportadoras de Cálcio/genética , Doença de Darier/genética , Mutação , ATPases Transportadoras de Cálcio/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Queratinócitos/fisiologia , Masculino , Dados de Sequência Molecular
4.
J Frailty Aging ; 11(1): 74-82, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35122094

RESUMO

BACKGROUND: Older adults with Type 2 diabetes (T2D) are more likely to be frail, which increases the risk for disability and mortality. OBJECTIVES: To determine the feasibility of a behavioral lifestyle intervention, enhanced with mobile health technology for self-monitoring of diet and activity, to improve frailty in overweight/obese older adults (≥65 years) diagnosed with T2D. DESIGN, SETTING, AND PARTICIPANTS: Single arm, 6-month study of a behavioral lifestyle intervention in 20 overweight/obese (BMI>25) older adults (≥ 65 years) with self-reported T2D diagnosis who owned a smartphone. A Fitbit tracker was provided to all participants for self-monitoring of diet and physical activity. Our primary outcome of feasibility was measured by session attendance, adherence to Fitbit usage to self-monitor diet and physical activity, and study retention. Secondary outcomes included the preliminary efficacy of the intervention on frailty, physical function, quality of life, and T2D-related outcomes. RESULTS: Eighteen participants completed the study. The mean age was 71.5 (SD ± 5.3) years, 56% were female, and half were Hispanic. At baseline, 13 (72%) were pre-frail, 4 (22%) were frail, and 1 (6%) were non-frail. At follow-up, frailty scores improved significantly from 1.61 ± 1.15 to 0.94 ± 0.94 (p=0.01) and bodyweight improved from 205.66 ± 45.52 lbs. to 198.33 ± 43.6 lbs. (p=<0.001). CONCLUSION: This study provides evidence for the feasibility of a behavioral lifestyle intervention in overweight/obese older adults with T2D and preliminary results support its potential efficacy in improving frailty score.


Assuntos
Diabetes Mellitus Tipo 2 , Fragilidade , Idoso , Diabetes Mellitus Tipo 2/terapia , Estudos de Viabilidade , Feminino , Humanos , Estilo de Vida , Obesidade/terapia , Sobrepeso/terapia , Qualidade de Vida
5.
Nature ; 432(7019): 878-81, 2004 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-15602555

RESUMO

The Earth's radiation belts--also known as the Van Allen belts--contain high-energy electrons trapped on magnetic field lines. The centre of the outer belt is usually 20,000-25,000 km from Earth. The region between the belts is normally devoid of particles, and is accordingly favoured as a location for spacecraft operation because of the benign environment. Here we report that the outer Van Allen belt was compressed dramatically by a solar storm known as the 'Hallowe'en storm' of 2003. From 1 to 10 November, the outer belt had its centre only approximately 10,000 km from Earth's equatorial surface, and the plasmasphere was similarly displaced inwards. The region between the belts became the location of high particle radiation intensity. This remarkable deformation of the entire magnetosphere implies surprisingly powerful acceleration and loss processes deep within the magnetosphere.

6.
Rev Sci Instrum ; 79(2 Pt 1): 023301, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18315287

RESUMO

The construction and testing of a portable energy-sensitive neutron instrument are described. This instrument has been designed and constructed for the primary purpose of characterizing cosmic-ray neutron fields in the upper atmosphere and in cosmic reference field facilities. The instrument comprises a helium-3 proportional counter surrounded by 15 mm of lead and 140 mm of polyethylene creating a spherical structure with a diameter of 34 cm. The instrument also incorporates 12 boron-coated diodes, six on the outside of the polyethylene layer with six placed within the structure. The dimensions, materials, and arrangement of these in the instrument have previously been optimized with the MCNPX Monte Carlo simulation software to provide a compromise between the requirements of portability and spectral response. Testing took place at several locations and experimental data from the instrument's operation at the high-altitude Jungfraujoch laboratory in the Swiss alps are presented.

7.
Radiat Prot Dosimetry ; 123(1): 3-14, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16829509

RESUMO

The design of a portable three-band cosmic-ray neutron detector is reported in this article. This instrument has been designed to characterise cosmic ray neutron fields in the upper atmosphere and in cosmic reference field facilities. The design utilises a spherical moderator with a layer of spallation material covering a central (3)He proportional counter. The instrument incorporates twelve lithium-coated diodes, six on the outside of the polyethylene layer and six placed within the structure. The dimensions, materials and arrangement of these in the instrument have been optimised with MCNPX to provide a compromise between the requirements of portability and spectral response.


Assuntos
Radiação Cósmica , Nêutrons , Monitoramento de Radiação/instrumentação , Lítio/química , Método de Monte Carlo , Processamento de Sinais Assistido por Computador , Silício/química , Análise Espectral
8.
J Prev Alzheimers Dis ; 4(4): 247-254, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29181490

RESUMO

Several ongoing clinical development programs are investigating potential disease-modifying treatments for Alzheimer's disease (AD), including lanabecestat (AZD3293/LY3314814). Lanabecestat is a brain-permeable oral inhibitor of human beta-site amyloid (Aß) precursor protein-cleaving enzyme 1 (BACE1) that reduces Aß production. As a potent BACE1 inhibitor, lanabecestat significantly reduced soluble Aß species and soluble amyloid precursor proteins (sAPPß) in mouse, guinea pig, and dog in a time- and dose-dependent manner. Significant reductions in plasma and cerebrospinal fluid (CSF) Aß1-40 and Aß1-42 were observed in Phase 1 studies of healthy subjects and AD patients treated with lanabecestat. Three lanabecestat trials are ongoing and intended to support registration in Early AD: (1) Phase 2/3 study in patients with mild cognitive impairment (MCI) due to AD and mild AD dementia (AMARANTH, NCT02245737); (2) Delayed-start extension study (AMARANTH-EXTENSION, NCT02972658) for patients who have completed treatment in the AMARANTH Study; and (3) Phase 3 study in mild AD dementia (DAYBREAK-ALZ, NCT02783573). This review will discuss the development of lanabecestat, results from the completed nonclinical and clinical studies, as well as describe the ongoing Phase 3 clinical trials.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Compostos de Espiro/farmacologia , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/tratamento farmacológico , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Ensaios Clínicos como Assunto , Disfunção Cognitiva/sangue , Disfunção Cognitiva/líquido cefalorraquidiano , Disfunção Cognitiva/tratamento farmacológico , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/uso terapêutico , Humanos , Imidazóis/farmacocinética , Imidazóis/uso terapêutico , Compostos de Espiro/farmacocinética , Compostos de Espiro/uso terapêutico
9.
Respir Med ; 100(2): 300-6, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16002272

RESUMO

There is increasing interest in ethane (C(2)H(6)) in exhaled breath as a non-invasive marker of oxidative stress (OS) and thereby a potential indicator of disease. However, the lack of real-time measurement techniques has limited progress in the field. Here we report on a novel Tunable Diode Laser Spectrometer (TDLS) applied to the analysis of exhaled ethane in patients with lung cancer. The patient group (n=52) comprised randomly selected patients presenting at a respiratory clinic. Of these, a sub-group (n=12) was subsequently diagnosed with lung cancer. An age-matched group (n=12) corresponding to the lung cancer group was taken from a larger control group of healthy adults (n=58). The concentration of ethane in a single exhaled breath sample collected from all subjects was later measured using the TDLS. This technique is capable of real-time analysis of samples with accuracy 0.1 parts per billion (ppb), over 10 times less than typical ambient levels in the northern hemisphere. After correcting for ambient background, ethane in the control group (26% smokers) ranged from 0 to 10.54 ppb (median of 1.9 ppb) while ethane in the lung cancer patients (42% smokers) ranged from 0 to 7.6 ppb (median of 0.7 ppb). Ethane among the non-lung cancer patients presenting for investigation of respiratory disease ranged from 0 to 25 ppb (median 1.45 ppb). We conclude that, while the TDLS proved effective for accurate and rapid sample analysis, there was no significant difference in exhaled ethane among any of the subject groups. Comments are made on the suitability of the technique for monitoring applications.


Assuntos
Etano/análise , Lasers , Neoplasias Pulmonares/diagnóstico , Idoso , Testes Respiratórios/métodos , Estudos de Casos e Controles , Humanos , Estudos Prospectivos , Distribuição Aleatória , Sensibilidade e Especificidade , Análise Espectral/normas
10.
Radiat Prot Dosimetry ; 164(3): 228-38, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25342608

RESUMO

Here, the characterisation of the high-energy neutron field at TRIUMF (The Tri Universities Meson Facility, Vancouver, British Columbia) with Monte Carlo simulation software is described. The package used is MCNPX version 2.6.0, with the neutron fluence rate determined at three locations within the TRIUMF Thermal Neutron Facility (TNF), including the exit of the neutron channel where users of the facility can test devices that may be susceptible to the effects of this form of radiation. The facility is often used to roughly emulate the field likely to be encountered at high altitudes due to radiation of galactic origin and thus the simulated information is compared with the energy spectrum calculated to be due to neutron radiation of cosmic origin at typical aircraft altitudes. The calculated values were also compared with neutron flux measurements that were estimated using the activation of various foils by the staff of the facility, showing agreement within an order of magnitude.


Assuntos
Simulação por Computador , Método de Monte Carlo , Nêutrons , Monitoramento de Radiação/instrumentação , Proteção Radiológica/instrumentação , Software , Aeronaves , Altitude , Radiação Cósmica , Humanos , Doses de Radiação
11.
Neuropharmacology ; 41(8): 1013-6, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11747906

RESUMO

The present study generated a polyclonal antibody (AP86/3) that recognises a peptide sequence of the h5-HT(3B) receptor subunit. Western blot analysis of homogenates prepared from cell lines expressing either homomeric (h5-HT(3A)) or heteromeric (h5-HT(3A/3B)) receptors, as well as immunocytochemical studies with the same cell lines, indicated that AP86/3 recognised, selectively, the 5-HT(3B) subunit. Immunohistochemical labelling was also apparent in cells in the rat hippocampus that displayed the distribution and morphology of interneurones.


Assuntos
Anticorpos/metabolismo , Hipocampo/citologia , Hipocampo/imunologia , Receptores de Serotonina/imunologia , Receptores de Serotonina/metabolismo , Animais , Reações Antígeno-Anticorpo , Linhagem Celular , Humanos , Soros Imunes/metabolismo , Imuno-Histoquímica , Masculino , Coelhos , Ratos , Ratos Wistar , Receptores 5-HT3 de Serotonina
12.
J Appl Physiol (1985) ; 62(3): 978-82, 1987 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3571096

RESUMO

Pregnant T-O mice were exposed to 50 ATA He-O2 pressure for 4 days at different stages of gestation: 4-7, 6-9, and 9-12 days gestation. Controls were exposed to 1 atmosphere absolute (ATA) air. After the exposure period, pregnancy continued until 18 days gestation when the mice were killed and autopsied. Data were collected relating to the litters and placentas (Litter size, percent resorptions, placental weight, fetal-to-placental ratio) and fetuses (weight, crown-rump length, sex, skeletal abnormalities) and analyzed using analysis of variance. Results showed a small but significant increase in the percent resorptions in the pressure group and also a decrease in crown-rump length and placental weight. None of these changes were related to the stage of gestation in which the mice were exposed. No teratogenic effects of pressure were seen. We conclude that exposure to 50 ATA He-O2 during pregnancy in mice produces a small nonselective effect on fetal growth and development but does not affect any specific event taking place during these stages of embryogenesis.


Assuntos
Feto/efeitos dos fármacos , Hélio/farmacologia , Prenhez/efeitos dos fármacos , Animais , Feminino , Reabsorção do Feto/fisiopatologia , Camundongos , Camundongos Endogâmicos , Tamanho do Órgão/efeitos dos fármacos , Placenta/anatomia & histologia , Placenta/efeitos dos fármacos , Gravidez
13.
Toxicol Lett ; 7(3): 259-62, 1981 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7013158

RESUMO

The mutagenic and toxic potential of nitrous oxide were assessed in vitro by microbial assay using two histidine dependent strains of Salmonella typhimurium, TA98 and TA100. Bacteria on plates and in liquid suspension in the presence or absence of enzymes prepared from rat liver, were exposed in a pressure chamber to partial pressures of nitrous oxide ranging from 0.5 to 6 atmospheres. Nitrous oxide decreased viability of both strains of bacteria at 4 and 6 atmospheres but was not mutagenic at any pressure tested.


Assuntos
Óxido Nitroso/toxicidade , Animais , Técnicas In Vitro , Microssomos Hepáticos/metabolismo , Mutação/efeitos dos fármacos , Óxido Nitroso/metabolismo , Pressão , Ratos , Salmonella typhimurium/efeitos dos fármacos
14.
Toxicol Lett ; 9(3): 201-6, 1981 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7031991

RESUMO

The mutagenic and toxic effect of high helium and hydrostatic pressure were assessed in an in vitro microbial assay using two histidine-dependent strains of Salmonella typhimurium. TA98 and TA100. Bacteria in the presence or absence of mammalian enzyme system were subjected to either 50 or 100 atmospheres absolute (ATA) helium or 300 ATA hydrostatic pressure. The number of revertant colonies, colony forming units and cell growth rates were measured. There was no mutagenic effect of decrease in number of colony forming units at any of the pressures tested. However, a statistically significant decrease in growth rate of exponentially dividing cells was seen at 300 ATA hydrostatic pressure and 100 ATA helium, but not at 50 ATA helium.


Assuntos
Hélio/toxicidade , Pressão Hidrostática/efeitos adversos , Mutação , Pressão/efeitos adversos , Testes de Mutagenicidade , Salmonella typhimurium/genética , Salmonella typhimurium/crescimento & desenvolvimento , Salmonella typhimurium/fisiologia
15.
Appl Radiat Isot ; 70(7): 1288-90, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22189372

RESUMO

A Monte Carlo simulation package, MCNPX version 2.6.0, has been used to evaluate the effect on the response of a spherical neutron detector utilising various numbers of point detectors on the surface of a spherical polyethylene structure, which forms an instrument specifically designed for low radiation environments.

16.
Appl Radiat Isot ; 70(7): 1370-2, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22112596

RESUMO

The viability of various materials and blanket designs for use in nuclear fusion reactors can be tested using computer simulations and as parts of the test blanket modules within the International Thermonuclear Experimental Reactor (ITER) facility. The work presented here focuses on blanket model simulations using the Monte Carlo simulation package MCNPX (Computational Physics Division Los Alamos National Laboratory, 2010) and FISPACT (Forrest, 2007) to evaluate the tritium breeding capability of a number of solid and liquid breeding materials. The liquid/molten salt breeders are found to have the higher tritium breeding ratio (TBR) and are to be considered for further analysis of the self sufficiency timing.

17.
Appl Radiat Isot ; 70(7): 1145-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22221462

RESUMO

A portable neutron spectrometry and dosimetry measurement device is in the process of development, which will be capable of accurate characterisation of neutron fields. The instrument is an amalgamation of two well-known techniques the Bonner-sphere and the surface barrier detector. Recent developments in semiconductor materials have allowed the growth of large-area thin-film based semiconductors upon high density polyethylene substrates, on which this detector is formed. Herein we discuss three plausible detection devices and test their results.

18.
Radiat Prot Dosimetry ; 144(1-4): 182-6, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21186216

RESUMO

A Monte Carlo-based simulation of the transport of a series of monoenergetic neutron sources through first a rectangular block of 0.93 g cm(-3) density polyethylene and secondly through a sphere made of the same substance is presented here. In both instances, the neutron fields are monitored at closely spread intervals through the moderator mass, producing a lot of data in the process. To reduce the amount of data presented, a figure of merit is created by estimating the cross section for each discrete neutron energy and by applying this to the number of neutrons present of each energy giving an arbitrary response figure. This work was undertaken in order to aid the design and development of a novel neutron spectrometer.


Assuntos
Polietileno/análise , Monitoramento de Radiação/instrumentação , Proteção Radiológica/instrumentação , Radiometria/instrumentação , Espectrofotometria/instrumentação , Partículas alfa , Partículas beta , Simulação por Computador , Desenho de Equipamento , Humanos , Teste de Materiais , Método de Monte Carlo , Nêutrons , Probabilidade , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos , Radiometria/métodos , Espectrofotometria/métodos
19.
Radiat Prot Dosimetry ; 144(1-4): 249-52, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21186214

RESUMO

Solid state-based surface barrier detectors (SBDs) have been employed in neutron radiation dosimetry for over half a century, each combination of detector featuring positives and pitfalls. Here the implications of constructing a portable neutron spectrometer device, based upon moderating high-density polyethylene substrates and utilising different types of large-area solid state SBDs, are discussed.


Assuntos
Polietileno/química , Radiometria/instrumentação , Algoritmos , Desenho de Equipamento , Hidrogênio/química , Teste de Materiais , Nêutrons , Oxigênio/química , Polietileno/análise , Doses de Radiação , Radiometria/métodos , Espectrofotometria/métodos , Propriedades de Superfície , Temperatura , Fatores de Tempo
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