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1.
BMJ ; 384: q524, 2024 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443067
2.
BMJ ; 384: q92, 2024 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-38233066
3.
Brain Behav ; 8(4): e00919, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29670817

RESUMO

Introduction: The nerve sonographic features of Dejerine-Sottas disease (DSD) have not previously been described. Methods: This exploratory cross-sectional, matched, case-control study investigated differences in nerve cross-sectional area (CSA) in children with DSD compared to healthy controls and children with Charcot-Marie-Tooth disease type 1A (CMT1A). CSA of the median, ulnar, tibial, and sural nerves was measured by peripheral nerve ultrasound. The mean difference in CSA between children with DSD, controls, and CMT1A was determined individually and within each group. Results: Five children with DSD and five age- and sex-matched controls were enrolled. Data from five age-matched children with CMT1A was also included. Group comparison showed no mean difference in nerve CSA between children with DSD and controls. Individual analysis of each DSD patient with their matched control indicated an increase in nerve CSA in three of the five children. The largest increase was observed in a child with a heterozygous PMP22 point mutation (nerve CSA fivefold larger than a control and twofold larger than a child with CMT1A). Nerve CSA was moderately increased in two children-one with a heterozygous mutation in MPZ and the other of unknown genetic etiology. Conclusions: Changes in nerve CSA on ultrasonography in children with DSD differ according to the underlying genetic etiology, confirming the variation in underlying pathobiologic processes and downstream morphological abnormalities of DSD subtypes. Nerve ultrasound may assist in the clinical phenotyping of DSD and act as an adjunct to known distinctive clinical and neurophysiologic findings of DSD subtypes. Larger studies in DSD cohorts are required to confirm these findings.


Assuntos
Doença de Charcot-Marie-Tooth/diagnóstico por imagem , Neuropatia Hereditária Motora e Sensorial/diagnóstico por imagem , Nervos Periféricos/diagnóstico por imagem , Estudos de Casos e Controles , Doença de Charcot-Marie-Tooth/genética , Criança , Pré-Escolar , Estudos Transversais , Proteína 2 de Resposta de Crescimento Precoce/genética , Feminino , Neuropatia Hereditária Motora e Sensorial/genética , Neuropatia Hereditária Motora e Sensorial/fisiopatologia , Heterozigoto , Humanos , Masculino , Nervo Mediano/diagnóstico por imagem , Nervo Mediano/patologia , Proteína P0 da Mielina/genética , Proteínas da Mielina/genética , Condução Nervosa , Tamanho do Órgão , Nervos Periféricos/patologia , Mutação Puntual , Nervo Sural/diagnóstico por imagem , Nervo Sural/patologia , Nervo Tibial/diagnóstico por imagem , Nervo Tibial/patologia , Nervo Ulnar/diagnóstico por imagem , Nervo Ulnar/patologia , Ultrassonografia
4.
Vet Rec ; 180(20): 499, 2017 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-28242781

RESUMO

Footpad dermatitis and hockburn are serious welfare and economic issues for the production of broiler (meat) chickens. The authors here describe the use of an inexpensive camera system that monitors the movements of broiler flocks throughout their lives and suggest that it is possible to predict, even in young birds, the cross-sectional prevalence at slaughter of footpad dermatitis and hockburn before external signs are visible. The skew and kurtosis calculated from the authors' camera-based optical flow system had considerably more power to predict these outcomes in the 50 flocks reported here than water consumption, bodyweight or mortality and therefore have the potential to inform improved flock management through giving farmers early warning of welfare issues. Further trials are underway to establish the generality of the results.


Assuntos
Dermatite/veterinária , Doenças do Pé/veterinária , Doenças das Aves Domésticas/diagnóstico , Tarso Animal/patologia , Bem-Estar do Animal , Animais , Peso Corporal , Galinhas , Estudos Transversais , Dermatite/diagnóstico , Ingestão de Líquidos , Doenças do Pé/diagnóstico , Fenômenos Ópticos , Valor Preditivo dos Testes
5.
Appl Ergon ; 59(Pt A): 342-356, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27890147

RESUMO

Involving users through participation in healthcare service and environment design is growing. Existing approaches and toolkits for practitioners and researchers are often paper based involving workshops and other more traditional design approaches such as paper prototyping. The advent of digital technology provides the opportunity to explore new platforms for user participation. This paper presents results from three studies that used a bespoke situated user participation digital kiosk, engaging 33 users in investigating healthcare environment design. The studies, from primary and secondary care settings, allowed participant feedback on each environment and proved a novel, engaging "21st century" way to participate in the appraisal of the design process. The results point toward this as an exciting and growing area of research in developing not just a new method of user participation but also the technology that supports it. Limitations were noted in terms of data validity and engagement with the device. To guide the development of user participation using similar situated digital devices, key lessons and reflections are presented.


Assuntos
Participação da Comunidade , Coleta de Dados/métodos , Planejamento Ambiental , Ambiente de Instituições de Saúde , Adulto , Atitude do Pessoal de Saúde , Terminais de Computador , Arquitetura de Instituições de Saúde , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Participação do Paciente , Interface Usuário-Computador , Adulto Jovem
6.
Vaccine ; 34(15): 1739-43, 2016 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-26921781

RESUMO

Campylobacter is the leading cause of food-borne diarrhoea in humans in the developed world and consumption of contaminated poultry meat is the main source of infection. Vaccination of broilers could reduce carcass contamination and zoonotic infections. Towards this aim, we evaluated recombinant anti-Campylobacter subunit vaccines based on the flagellum-capping protein FliD and the flagellum-secreted protein FspA as they are immunogenic in chickens and the flagellum is vital for colonisation. In three studies, a recombinant FliD vaccine induced a transient but reproducible and statistically significant decrease of c. 2 log10 CFU/g in caecal colonisation levels at 49 days post-primary vaccination on the day of hatch. Levels of serum IgY specific to FliD positively correlated with caecal bacterial counts in individual birds, indicating that such antibodies may not play a role in protection. The data add to the limited repertoire of candidate antigens for the control of a key foodborne zoonosis.


Assuntos
Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Infecções por Campylobacter/veterinária , Flagelos/imunologia , Doenças das Aves Domésticas/prevenção & controle , Transportadores de Cassetes de Ligação de ATP/imunologia , Sistemas de Transporte de Aminoácidos Neutros/imunologia , Animais , Anticorpos Antibacterianos/sangue , Carga Bacteriana , Infecções por Campylobacter/prevenção & controle , Campylobacter jejuni , Ceco/microbiologia , Galinhas , Imunoglobulinas/sangue , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/imunologia
7.
Neurology ; 84(6): 569-74, 2015 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-25576636

RESUMO

OBJECTIVE: To investigate differences in nerve cross-sectional area (CSA) as measured by peripheral nerve ultrasound in children with Charcot-Marie-Tooth disease type 1A (CMT1A) compared to healthy controls. METHODS: This was a cross-sectional, matched, case-control study. CSA of the median, ulnar, tibial, and sural nerves was measured by peripheral nerve ultrasound. The mean difference in CSA between children with CMT1A and controls at each nerve site was determined. The relationship between nerve CSA and age/body metrics, and between nerve CSA and neurologic disability in CMT1A, was also evaluated. RESULTS: Twenty-nine children with CMT1A and 29 age- and sex-matched controls were enrolled. Nerve CSA was significantly increased in children with CMT1A compared to controls (1.9- to 3.5-fold increase, p < 0.001). The increase in nerve CSA with age was disproportionately greater in those with CMT1A. Nerve CSA showed a strong positive linear correlation with age, height, and weight in both the CMT1A and control groups. Disease severity correlated with both nerve CSA and age. CONCLUSIONS: Children with CMT1A have significantly increased nerve CSA compared to controls, and the increase in nerve CSA with age is disproportionately greater in CMT1A, suggesting ongoing nerve hypertrophy throughout childhood. Nerve CSA correlates with neurologic disability. These findings demonstrate the utility of peripheral nerve ultrasound as a diagnostic tool in pediatric neuropathies, and as an outcome measure in natural history studies and clinical trials in CMT1A. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that measurement of nerve CSA by peripheral nerve ultrasound accurately identifies patients with CMT1A.


Assuntos
Doença de Charcot-Marie-Tooth/diagnóstico por imagem , Doença de Charcot-Marie-Tooth/patologia , Nervos Periféricos/diagnóstico por imagem , Nervos Periféricos/patologia , Adolescente , Fatores Etários , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos Transversais , Pessoas com Deficiência , Feminino , Humanos , Hipertrofia/diagnóstico por imagem , Masculino , Nervo Mediano/diagnóstico por imagem , Nervo Mediano/patologia , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Nervo Sural/diagnóstico por imagem , Nervo Sural/patologia , Nervo Tibial/diagnóstico por imagem , Nervo Tibial/patologia , Nervo Ulnar/diagnóstico por imagem , Nervo Ulnar/patologia , Ultrassonografia
8.
Appl Ergon ; 45(6): 1454-60, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24768090

RESUMO

Sound is often considered as a negative aspect of an environment that needs mitigating, particularly in hospitals. It is worthwhile however, to consider how subjective responses to hospital sounds can be made more positive. The authors identified natural sound, steady state sound and written sound source information as having the potential to do this. Listening evaluations were conducted with 24 participants who rated their emotional (Relaxation) and cognitive (Interest and Understanding) response to a variety of hospital ward soundscape clips across these three interventions. A repeated measures ANOVA revealed that the 'Relaxation' response was significantly affected (n(2) = 0.05, p = 0.001) by the interventions with natural sound producing a 10.1% more positive response. Most interestingly, written sound source information produced a 4.7% positive change in response. The authors conclude that exploring different ways to improve the sounds of a hospital offers subjective benefits that move beyond sound level reduction. This is an area for future work to focus upon in an effort to achieve more positively experienced hospital soundscapes and environments.


Assuntos
Estimulação Acústica/psicologia , Percepção Auditiva , Ambiente de Instituições de Saúde , Hospitais , Ruído , Adulto , Emoções , Feminino , Humanos , Masculino , Inquéritos e Questionários
9.
Ergonomics ; 56(11): 1687-97, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24073684

RESUMO

Work on the perception of urban soundscapes has generated a number of perceptual models which are proposed as tools to test and evaluate soundscape interventions. However, despite the excessive sound levels and noise within hospital environments, perceptual models have not been developed for these spaces. To address this, a two-stage approach was developed by the authors to create such a model. First, semantics were obtained from listening evaluations which captured the feelings of individuals from hearing hospital sounds. Then, 30 participants rated a range of sound clips representative of a ward soundscape based on these semantics. Principal component analysis extracted a two-dimensional space representing an emotional-cognitive response. The framework enables soundscape interventions to be tested which may improve the perception of these hospital environments.


Assuntos
Estimulação Acústica/psicologia , Percepção Auditiva , Emoções , Ambiente de Instituições de Saúde , Hospitais , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Ruído , Análise de Componente Principal , Semântica , Adulto Jovem
10.
Osteoarthritis Cartilage ; 18(7): 992-1000, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20434574

RESUMO

OBJECTIVE: The purpose of this study was to use microarray technology to: (1) understand the early molecular events underlying the damage of articular cartilage initiated by this surgical procedure, and (2) determine whether these changes mimic those that are occurring in human osteoarthritic (OA) cartilage. DESIGN: Cartilage was harvested from both medial and lateral sides of the tibial plateaus and femoral condyles of both meniscal tear (MT) and sham surgery groups on days 3, 7 and 21 post-surgery. mRNA prepared from these rat cartilage samples was used for microarray analysis. RESULTS: Statistical analysis identified 475 genes that were differentially expressed between the sham and MT groups, at one or more of the time points that were analyzed. By integrating these genes with OA-related genes reported previously in a rat OA model and in human OA array studies, we identified 20 commonly changed genes. Six out of these 20 genes (Col5A1, Col6A2, INHBA, LTBP2, NBL1 and SERPINA1) were differentially expressed in two animal models and in human OA. Pathway analysis identified some key features of OA pathology, namely cartilage extracellular matrix remodeling, angiogenesis, and chondrocyte cell death that were recapitulated in the animal models. The rat models suggested increased inflammation and cholesterol metabolic pathways may play important role in early cartilage degeneration. CONCLUSION: We identified a large number of differentially expressed genes in the articular cartilage of the MT model. While there was lack of overall identity in cartilage gene expression between the rat models and human OA, several key biological processes were recapitulated in the rat MT OA model.


Assuntos
Lesões do Ligamento Cruzado Anterior , Artrite Experimental/metabolismo , Cartilagem Articular/metabolismo , Osteoartrite/metabolismo , Lesões do Menisco Tibial , Animais , Fêmur/metabolismo , Humanos , Masculino , Análise em Microsséries , Modelos Animais , Ratos , Ratos Endogâmicos Lew , Tíbia/metabolismo
11.
Rev Sci Instrum ; 78(8): 084103, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17764339

RESUMO

We use a multiwell micromechanical cantilever sensor (MCS) device to measure surface stress changes induced by specific adsorption of molecules. A multiplexed assay format facilitates the monitoring of the bending of 16 MCSs in parallel. The 16 MCSs are grouped within four separate wells. Each well can be addressed independently by different analyte liquids. This enables functionalization of MCS separately by flowing different solutions through each well. In addition, each well contains a fixed reference mirror which allows measuring the absolute bending of MCS. In addition, the mirror can be used to follow refractive index changes upon mixing of different solutions. The effect of the flow rate on the MCS bending change was found to be dependent on the absolute bending value of MCS. Experiments and finite element simulations of solution exchange in wells were performed. Both revealed that one solution can be exchanged by another one after 200 microl volume has flown through. Using this device, the adsorption of thiolated DNA molecules and 6-mercapto-1-hexanol on gold surfaces was performed to test the nanomechanical response of MCS.


Assuntos
Técnicas Biossensoriais/instrumentação , Biotecnologia/instrumentação , Análise de Injeção de Fluxo/instrumentação , Análise em Microsséries/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Fotometria/instrumentação , Transdutores , Técnicas Biossensoriais/métodos , Biotecnologia/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Análise de Injeção de Fluxo/métodos , Teste de Materiais/instrumentação , Teste de Materiais/métodos , Mecânica , Análise em Microsséries/métodos , Técnicas Analíticas Microfluídicas/métodos , Miniaturização , Fotometria/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Bone ; 40(4): 1103-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17258520

RESUMO

Serum PINP has emerged as a reliable marker of bone turnover in humans and is routinely used to monitor bone formation. However, the effects of PTH (1-34) on bone turnover have not been evaluated following short-term treatment. We present data demonstrating that PINP is an early serum biomarker in the rat for assessing bone anabolic activity in response to treatment with PTH (1-38). Rat serum PINP levels were found to increase following as few as 6 days of treatment with PTH (1-38) and these increases paralleled expression of genes associated with bone formation, as well as, later increases in BMD. Additionally, PINP levels were unaffected by treatment with an antiresorptive bisphosphonate. PINP may be used to detect PTH-induced early bone formation in the rat and may be more generally applicable for preclinical testing of potential bone anabolic drugs.


Assuntos
Remodelação Óssea/fisiologia , Osteogênese/fisiologia , Fragmentos de Peptídeos/sangue , Pró-Colágeno/sangue , Animais , Biomarcadores/sangue , Remodelação Óssea/efeitos dos fármacos , Remodelação Óssea/genética , Proteínas de Sinalização Intercelular CCN , Carboxipeptidases/genética , Colágeno/genética , Colágeno Tipo I , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Oncogênicas/genética , Osteocalcina/genética , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Ovariectomia , Hormônio Paratireóideo/farmacologia , Fragmentos de Peptídeos/farmacologia , Proteínas Proto-Oncogênicas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia
13.
J Biomech ; 40(1): 125-36, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16376354

RESUMO

Both computational finite element and experimental models of the human torso have been developed for ballistic impact testing. The human torso finite element model (HTFEM), including the thoracic skeletal structure and organs, was created in the finite element code LS-DYNA. The skeletal structure was assumed to be linear-elastic while all internal organs were modeled as viscoelastic. A physical human surrogate torso model (HSTM) was developed using biosimulant materials and the same anthropometry as the HTFEM. The HSTM response to impact was recorded with piezoresistive pressure sensors molded into the heart, liver and stomach and an accelerometer attached to the sternum. For experimentation, the HSTM was outfitted with National Institute of Justice (NIJ) Level I, IIa, II and IIIa soft armor vests. Twenty-six ballistic tests targeting the HSTM heart and liver were conducted with 22 caliber ammunition at a velocity of 329 m/s and 9 mm ammunition at velocities of 332, 358 and 430 m/s. The HSTM pressure response repeatability was found to vary by less than 10% for similar impact conditions. A comparison of the HSTM and HTFEM response showed similar pressure profiles and less than 35% peak pressure difference for organs near the ballistic impact point. Furthermore, the peak sternum accelerations of the HSTM and HTFEM varied by less than 10% for impacts over the sternum. These models provide comparative tools for determining the thoracic response to ballistic impact and could be used to evaluate soft body armor design and efficacy, determine thoracic injury mechanisms and assist with injury prevention.


Assuntos
Balística Forense , Fenômenos Biomecânicos , Análise de Elementos Finitos , Balística Forense/estatística & dados numéricos , Humanos , Modelos Anatômicos , Modelos Biológicos , Modelos Estatísticos , Traumatismos Torácicos/etiologia , Traumatismos Torácicos/fisiopatologia , Tórax/anatomia & histologia
14.
J Econ Entomol ; 99(2): 373-82, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16686135

RESUMO

We compared naturally baited trapping systems to synthetically baited funnel traps and fallen trap trees for suppressing preoutbreak spruce beetle, Dendroctonus rufipennis Kirby, populations. Lures for the traps were fresh spruce (Picea spp.) bolts or bark sections, augmented by adding female spruce beetles to create secondary attraction. In 2003, we compared a naturally baited system ("bolt trap") with fallen trap trees and with synthetically baited funnel traps. Trap performance was evaluated by comparing total beetle captures and spillover of attacks into nearby host trees. Overall, the trap systems did not significantly differ in spruce beetle captures, although bolt traps caught 6 to 7 times more beetles than funnel traps during the first 4 wk of testing. Funnel traps with synthetic lures had significantly more spillover than either trap trees or bolt traps. The study was repeated in 2004 with modifications including an enhanced blend synthetic lure. Again, trap captures were generally similar among naturally and synthetically baited traps, but naturally baited traps had significantly less spillover. Although relatively labor-intensive, the bolt trap could be used to suppress preoutbreak beetle populations, especially when spillover is undesirable. Our work provides additional avenues for management of spruce beetles and suggests that currently used synthetic lures can be improved.


Assuntos
Besouros/fisiologia , Controle de Insetos/métodos , Animais , Colorado , Fatores de Tempo , Árvores , Utah , Wyoming
15.
J Contam Hydrol ; 64(3-4): 191-202, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12814880

RESUMO

Tracer tests were conducted to evaluate the effect of a complexing sugar flush (CSF) on in-situ biodegradation potential at a site contaminated by jet fuel, solvents, and other organic compounds. Technical-grade hydroxypropyl-beta-cyclodextrin was used during the CSF study, which was conducted in a hydraulically isolated cell emplaced in a surficial aquifer. In-situ biodegradation potential was assessed with the use of tracer tests, which were conducted prior to and immediately following the CSF study. Ethanol, hexanol, and benzoate were used as the biodegradable tracers, while bromide was used as a nonreactive tracer. The results indicate that the biodegradation of benzoate was similar for both tracer tests. Conversely, the biodegradation of ethanol (23% increase) and hexanol (41% increase) was greater for the post-CSF tracer test. In addition, analysis of core samples collected from within the test cell indicates that the population density of aerobic jet-fuel degraders increased in the vicinity of the injection wells during the CSF. These results indicate that the cyclodextrin flush did not deleteriously affect the indigenous microbial community. This study illustrates that tracer tests can be used to evaluate the impact of remediation activities on in-situ biodegradation potential.


Assuntos
Ciclodextrinas/metabolismo , Hidrocarbonetos/metabolismo , Poluentes do Solo/metabolismo , Solventes/metabolismo , Poluentes da Água/metabolismo , beta-Ciclodextrinas , 2-Hidroxipropil-beta-Ciclodextrina , Bactérias , Benzoatos/metabolismo , Biodegradação Ambiental , Reatores Biológicos , Etanol/metabolismo , Hexanóis/metabolismo , Dinâmica Populacional
16.
Gene Ther ; 9(16): 1109-15, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12140739

RESUMO

Lung inflammation leads to severe tissue destruction and ultimately organ failure in a number of diseases, including cystic fibrosis (CF). The transcription factor nuclear factor kappa B (NFkappaB) regulates expression of many pro-inflammatory mediators. We have assessed the effect of topical administration of NFkappaB decoys in a bleomycin model of acute lung inflammation. Using fluorescein-labelled decoy oligonucleotides (ODN) (80 microg/mouse) we have shown that lipid-complexed and 'naked' ODN transfect conducting airway epithelium in a comparable manner (approximately 65% of cells). However, the ODN were detectable in the cytoplasm, but not in the nucleus of transfected cells. An increase of ODN dose to 500 microg/mouse did not increase nuclear transfection significantly. We determined the effect of cytoplasmic NFkappaB decoys on bleomycin-induced inflammation. We transfected mice with 'naked' decoy and scrambled ODN (500 microg) 1 h before intratracheal administration of bleomycin. We measured IL6 secretion in BALF and lung homogenates and total and differential cell counts in BALF 5 days after bleomycin administration. We did not detect a difference between NFkappaB decoy and scrambled ODN-treated animals in any of the parameters tested. We suggest that access of ODN to the nucleus of airway epithelial cells is a key problem, limiting the efficacy of such decoy strategies, as well as attempts at gene repair.


Assuntos
Terapia Genética/métodos , NF-kappa B/genética , Oligonucleotídeos/farmacocinética , Pneumonia/prevenção & controle , Animais , Bleomicina , Líquido da Lavagem Broncoalveolar/imunologia , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Feminino , Interleucina-6/biossíntese , Pulmão/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Mimetismo Molecular , Oligonucleotídeos/genética , Pneumonia/induzido quimicamente , Pneumonia/imunologia , Distribuição Tecidual , Transfecção
17.
Environ Sci Technol ; 36(5): 1033-41, 2002 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11917988

RESUMO

The purpose of this work is to examine the effect of nonuniform distributions of immiscible organic liquid on dissolution behavior, with a specific focus on the condition dependency of dissolution (i.e., mass transfer) rate coefficients associated with applying mathematical models of differing complexities to measured data. Dissolution experiments were conducted using intermediate-scale flow cells packed with sand in which well-characterized zones of residual trichloroethene (TCE) and 1,2-dichloroethane (DCA) saturation were emplaced. A dual-energy gamma radiation system was used for in-situ measurement of NAPL saturation. Aqueous concentrations of TCE and DCA measured in the flow-cell effluent were significantly less than solubility, due primarily to dilution associated with the nonuniform immiscible-liquid distribution and bypass flow effects associated with physical heterogeneity. A quantitative analysis of flow and transport was conducted using a three-dimensional mathematical model wherein immiscible-liquid distribution, permeability variability, and sampling effects were explicitly considered. Independent values for the initial dissolution rate coefficients were obtained from dissolution experiments conducted using homogeneously packed columns. The independent predictions obtained from the model provided good representations of NAPL dissolution behavior and of total TCE/DCA mass removed, signifying model robustness. This indicates that for the complex three-dimensional model, explicit consideration of the larger scale factors that influenced immiscible-liquid dissolution in the flow cells allowed the use of a dissolution rate coefficient that represents only local-scale mass transfer processes. Conversely, the use of simpler models that did not explicitly consider the nonuniform immiscible-liquid distribution required the use of dissolution rate coefficients that are approximately 3 orders of magnitude smaller than the values obtained from the column experiments. The rate coefficients associated with the simpler models represent composite or lumped coefficients that incorporate the effects of the larger scale dissolution processes associated with the nonuniform immiscible-liquid distribution, which are not explicitly represented in the simpler models, as well as local-scale mass transfer. These results demonstrate that local-scale dissolution rate coefficients, such as those obtained from column experiments, can be used in models to successfully predict dissolution and transport of immiscible-liquid constituents at larger scales when the larger scale factors influencing dissolution behavior are explicitly accounted for in the model.


Assuntos
Modelos Teóricos , Poluentes da Água/análise , Dicloretos de Etileno/química , Solubilidade , Solventes/química , Tricloroetileno/química , Movimentos da Água
18.
J Musculoskelet Neuronal Interact ; 2(4): 321-6, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15758423

RESUMO

Human parathyroid hormone (hPTH 1-34) stimulates an anabolic response in human and animal skeletons; however, it is unclear if the effect is strain dependent. To determine if the anabolic response to hPTH (1-34) was dependent upon strain in rats we used 2 outbred strains (Sprague Dawley, Wistar), 2 inbred strains (Fischer 344, Wistar spontaneously hypertensive:SHR), and 2 mutant strains (Zucker obese, Zucker lean) of rats. Male rats, 5 weeks of age, from each strain were treated subcutaneously with 80 microg/kg body weight hPTH (1-34) or vehicle for 12 days. The response to PTH was similar in all strains whereby PTH exerted an anabolic effect on femoral bone mass and cancellous bone histology that was independent of strain differences. Histomorphometric indices of bone volume, mineralized surface and bone formation in lumbar vertebrae increased in all PTH-treated rats. Additionally, femur bone mineral content and bone mineral density measured by dual energy X-ray absorptiometry (DEXA), and ash weight increased in all PTH-treated rats. These increases occurred regardless of strain. In summary, PTH exerted comparable anabolic effects on bone mass, bone mineral density and bone formation in all rat models tested demonstrating that the skeletal responsiveness to PTH was not dependent upon strain.

19.
Disabil Rehabil ; 23(14): 604-13, 2001 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-11697458

RESUMO

PURPOSE: This preliminary investigation of the use of voice recognition software by people with aphasia presents a new method of training the software, which allows the aphasic user to by-pass the linguistically demanding standard training. It examines how accurately voice recognition software performed with aphasic speech and language as compared to that of control subjects. METHOD: Five non-impaired controls and six participants with aphasia used a vocabulary of 50 words and 24 phrases to train the software over a maximum of five sessions. For the people with aphasia baseline assessments provided a profile of speech and language impairment. Measures of software accuracy were taken for all subjects at baseline and after four subsequent training sessions, for both single word and phrase level dictation. RESULTS: Word level production resulted in similar accuracy levels for both groups. Phrase level production showed greater accuracy levels than single word level production for both aphasics and controls, but participants with greater speech difficulties had lower software accuracy scores. CONCLUSIONS: Training the software on a specific vocabulary allows people to access it whose speech and language difficulties would otherwise have prevented them. Findings are discussed in relation to use of the software as a dictation tool and as an input device to therapy software.


Assuntos
Afasia/reabilitação , Software , Medida da Produção da Fala/instrumentação , Adulto , Idoso , Afasia/etiologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Valores de Referência , Sensibilidade e Especificidade , Inteligibilidade da Fala , Acidente Vascular Cerebral/complicações , Reabilitação do Acidente Vascular Cerebral , Terapia Assistida por Computador , Interface Usuário-Computador , Gravação em Vídeo , Voz
20.
Endocrinology ; 142(9): 4047-54, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11517184

RESUMO

Continuous infusion of PTH in vivo results in active bone resorption. To investigate the molecular basis of the catabolic effect of PTH in vivo, we evaluated the role of OPG and RANKL, which are known to influence osteoclast formation and function. Weanling rats fed a calcium-free diet were parathyroidectomized and infused with PTH via an Alzet pump to examine: 1) the changes of serum-ionized calcium and osteoclast number, 2) the expression of OPG/RANKL mRNA and protein, and 3) the expression of osteoblast phenotype bone formation-associated genes such as osteoblast specific transcription factor, osteocalcin, bone sialoprotein, and type I collagen. PTH (1--38) (0.01--20 microg/100 g) continuous infusion for 1--24 h resulted in a dose-dependent increase in serum-ionized calcium in parathyroidectomized rats and a corresponding dose-dependent increase in osteoclast number, indicating an increased bone resorption. At 20 microg/100 g PTH dose level, serum-ionized calcium was 2.1-fold of the vehicle control and not different from the Sham-parathyroidectomized rats, and osteoclast number was 3-fold of the vehicle control and 1.7-fold of the Sham-parathyroidectomized rats. In the distal femur, RANKL mRNA expression was increased (27-fold) and OPG mRNA expression was decreased (4.6-fold). The changes in RANKL and OPG mRNA levels were rapid (as early as 1 h), dose dependent, and sustained over a 24-h period that was examined. Immunohistochemical evaluation of bone sections confirmed that OPG level was reduced in proximal tibial metaphysis upon PTH infusion. Circulating OPG protein level was also decreased by 32% when compared with the parathyroidectomized control. The expression of genes that mark the osteoblast phenotype was significantly decreased [osteoblast specific transcription factor (2.3-fold), osteocalcin (3-fold), bone sialoprotein (2.8-fold), and type I collagen (5-fold)]. These results suggest that the catabolic effect of PTH infusion in vivo in this well-established resorption model is associated with a reciprocal expression of OPG/RANKL and a co-ordinate decrease in the expression of bone formation-related genes. We propose that the rapid and sustained increase in RANKL and decrease in OPG initiate maintain and favor the cascade of events in the differentiation/recruitment and activation of osteoclasts.


Assuntos
Glicoproteínas/antagonistas & inibidores , Glicoproteínas/metabolismo , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Hormônio Paratireóideo/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Reabsorção Óssea/patologia , Feminino , Fêmur/patologia , Fêmur/fisiopatologia , Glicoproteínas/genética , Humanos , Bombas de Infusão , Osteoblastos/fisiologia , Osteoprotegerina , Hormônio Paratireóideo/farmacologia , Fragmentos de Peptídeos/farmacologia , Fenótipo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Citoplasmáticos e Nucleares/genética , Receptores do Fator de Necrose Tumoral
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