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1.
Phys Rev Lett ; 132(15): 155102, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38683000

RESUMO

We present the first experimental study of plasmoid formation in a magnetic reconnection layer undergoing rapid radiative cooling, a regime relevant to extreme astrophysical plasmas. Two exploding aluminum wire arrays, driven by the Z machine, generate a reconnection layer (S_{L}≈120) in which the cooling rate far exceeds the hydrodynamic transit rate (τ_{hydro}/τ_{cool}>100). The reconnection layer generates a transient burst of >1 keV x-ray emission, consistent with the formation and subsequent rapid cooling of the layer. Time-gated x-ray images show fast-moving (up to 50 km s^{-1}) hotspots in the layer, consistent with the presence of plasmoids in 3D resistive magnetohydrodynamic simulations. X-ray spectroscopy shows that these hotspots generate the majority of Al K-shell emission (around 1.6 keV) prior to the onset of cooling, and exhibit temperatures (170 eV) much greater than that of the plasma inflows and the rest of the reconnection layer, thus providing insight into the generation of high-energy radiation in radiatively cooled reconnection events.

2.
Cell Rep ; 42(8): 112982, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37585292

RESUMO

In daylight, demand for visual chromophore (11-cis-retinal) exceeds supply by the classical visual cycle. This shortfall is compensated, in part, by the retinal G-protein-coupled receptor (RGR) photoisomerase, which is expressed in both the retinal pigment epithelium (RPE) and in Müller cells. The relative contributions of these two cellular pools of RGR to the maintenance of photoreceptor light responses are not known. Here, we use a cell-specific gene reactivation approach to elucidate the kinetics of RGR-mediated recovery of photoreceptor responses following light exposure. Electroretinographic measurements in mice with RGR expression limited to either cell type reveal that the RPE and a specialized subset of Müller glia contribute both to scotopic and photopic function. We demonstrate that 11-cis-retinal formed through photoisomerization is rapidly hydrolyzed, consistent with its role in a rapid visual pigment regeneration process. Our study shows that RGR provides a pan-retinal sink for all-trans-retinal released under sustained light conditions and supports rapid chromophore regeneration through the photic visual cycle.


Assuntos
Epitélio Pigmentado da Retina , Retinaldeído , Animais , Camundongos , Epitélio Pigmentado da Retina/metabolismo , Retinaldeído/metabolismo , Pigmentos da Retina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Neuroglia/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo
3.
Rev Sci Instrum ; 94(5)2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37184347

RESUMO

We report on progress implementing and testing cryogenically cooled platforms for Magnetized Liner Inertial Fusion (MagLIF) experiments. Two cryogenically cooled experimental platforms were developed: an integrated platform fielded on the Z pulsed power generator that combines magnetization, laser preheat, and pulsed-power-driven fuel compression and a laser-only platform in a separate chamber that enables measurements of the laser preheat energy using shadowgraphy measurements. The laser-only experiments suggest that ∼89% ± 10% of the incident energy is coupled to the fuel in cooled targets across the energy range tested, significantly higher than previous warm experiments that achieved at most 67% coupling and in line with simulation predictions. The laser preheat configuration was applied to a cryogenically cooled integrated experiment that used a novel cryostat configuration that cooled the MagLIF liner from both ends. The integrated experiment, z3576, coupled 2.32 ± 0.25 kJ preheat energy to the fuel, the highest to-date, demonstrated excellent temperature control and nominal current delivery, and produced one of the highest pressure stagnations as determined by a Bayesian analysis of the data.

4.
Proc Natl Acad Sci U S A ; 120(19): e2221045120, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37126699

RESUMO

Chronic, progressive retinal diseases, such as age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa, arise from genetic and environmental perturbations of cellular and tissue homeostasis. These disruptions accumulate with repeated exposures to stress over time, leading to progressive visual impairment and, in many cases, legal blindness. Despite decades of research, therapeutic options for the millions of patients suffering from these disorders remain severely limited, especially for treating earlier stages of pathogenesis when the opportunity to preserve the retinal structure and visual function is greatest. To address this urgent, unmet medical need, we employed a systems pharmacology platform for therapeutic development. Through integrative single-cell transcriptomics, proteomics, and phosphoproteomics, we identified universal molecular mechanisms across distinct models of age-related and inherited retinal degenerations, characterized by impaired physiological resilience to stress. Here, we report that selective, targeted pharmacological inhibition of cyclic nucleotide phosphodiesterases (PDEs), which serve as critical regulatory nodes that modulate intracellular second messenger signaling pathways, stabilized the transcriptome, proteome, and phosphoproteome through downstream activation of protective mechanisms coupled with synergistic inhibition of degenerative processes. This therapeutic intervention enhanced resilience to acute and chronic forms of stress in the degenerating retina, thus preserving tissue structure and function across various models of age-related and inherited retinal disease. Taken together, these findings exemplify a systems pharmacology approach to drug discovery and development, revealing a new class of therapeutics with potential clinical utility in the treatment or prevention of the most common causes of blindness.


Assuntos
Retinopatia Diabética , Degeneração Macular , Degeneração Retiniana , Retinose Pigmentar , Humanos , Retina/metabolismo , Degeneração Retiniana/metabolismo , Retinose Pigmentar/metabolismo , Degeneração Macular/patologia , Retinopatia Diabética/metabolismo
5.
Ann R Coll Surg Engl ; 105(6): 507-512, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36374289

RESUMO

INTRODUCTION: Workplace-based assessments (WBAs) are intended to maximise learning opportunities in surgical training. There is speculation as to whether mandatory assessments in this form contribute to a tick-box culture. The objective of this review was to investigate surgical trainees' attitudes towards WBAs. METHODS: This systematic review of qualitative studies was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement. The literature was searched on the Medline®, Embase™, PubMed and Web of Science™ databases on 22 March 2022. RESULTS: Sixteen studies were included in the review, mostly carried out on users of the Intercollegiate Surgical Curriculum Programme portfolio in the UK. Trainees felt that WBAs were educationally useful, providing opportunity for feedback, but this was overshadowed by a pressure to reach a set annual quota for WBAs and achieve high scores. Other themes included inaccurate recording of WBAs, the role of WBAs as formative or summative assessments, engagement and accessibility of trainers, and lack of time to complete WBAs. CONCLUSIONS: Negative perceptions about WBAs were widespread among surgical trainees despite a recognition of their capacity to facilitate learning. This review supports the recent removal of the annual quota for WBAs in UK surgical training programmes.


Assuntos
Competência Clínica , Local de Trabalho , Humanos , Avaliação Educacional , Currículo , Aprendizagem , Educação de Pós-Graduação em Medicina
6.
Eur J Cardiovasc Nurs ; 22(7): 719-729, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-36351004

RESUMO

AIMS: To (1) Describe the sociodemographic and risk factor profiles of a sample of patients with coronary disease, (2) Explore associations between illness perceptions and health literacy with sociodemographic characteristics and risk factors, health-related quality of life (HRQoL), anxiety, and depression. METHODS AND RESULTS: Conducted as part of the ESC Prevention of CVD Project and EUROASPIRE V survey, patients were consecutively and retrospectively identified 6 months to 2 years after an acute event or elective procedure from 12 countries and interviewed. Three thousand four hundred and eight participants (76% male, mean age 64 years) were recruited, 16% were smokers, 38% obese, 60% physically inactive, and 41% hypertensive. Forty percent had attended cardiac rehabilitation. More threatening illness perceptions were associated with female gender (P < 0.0001), lower income (P < 0.0001), lower education (P = 0.02), obesity (P < 0.0001), sedentary behaviour (P < 0.0001), and diabetes (P < 0.0001). Poorer health literacy was associated with obesity (P = 0.02) and sedentary behaviour (P = 0.0001). Threatening illness perceptions were strongly associated with anxiety, depression, and poorer ratings of HRQoL after multivariable adjustment (all P < 0.001). Poor health literacy was associated with anxiety and depression (P < 0.0001) and poorer ratings of HRQoL (HeartQol scores P = 0.03). Results were consistent across regions of Europe, age, gender, and socio-economic strata. CONCLUSIONS: Interventions like cardiac rehabilitation should be targeted at vulnerable groups given the strong associations between more threatening illness perceptions, lower health literacy, lower HRQoL, and higher levels of anxiety and depression. The delivery and content of these interventions should be accessible for those with low health literacy.


Assuntos
Doença da Artéria Coronariana , Letramento em Saúde , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Qualidade de Vida , Estudos Transversais , Depressão , Estudos Retrospectivos , Ansiedade , Obesidade
7.
Am J Infect Control ; 49(9): 1158-1161, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34454683

RESUMO

BACKGROUND: The purpose of this study was to assess the occupational SARS-CoV-2 infection risk among health care workers (HCW) at University of Kentucky HealthCare (UKHC) by evaluating the prevalence of SARS-CoV-2 antibodies. METHODS: This is a prospective cohort study of HCW at UKHC. SARS-CoV-2 IgG antibody seropositivity was measured in a CLIA-certified laboratory utilizing the Abbott Architect SARS-CoV-2 IgG antibody assay. Demographics and work type were self-reported by study participants via an emailed survey. RESULTS: The overall antibody positivity rate of HCW was 1.55% (5/322; 95% confidence interval: 0.65%-3.71%) at cohort entry. There were no differences in antibody positivity between those that worked directly with SARS-CoV-2 infected patients and those that did not. The antibody rate of positivity of patients during the same time period was similar, 1.8% (9/499; 95% confidence interval 0.94%-3.45%). CONCLUSIONS: Antibody positivity was low and similar between HCW and patients tested during a similar time period. HCW positivity rates did not appear to be impacted by caring for known SARS-CoV-2 infected patients suggesting that appropriate use of personal protective equipment is effective in protecting individuals from transmission.


Assuntos
COVID-19 , SARS-CoV-2 , Centros Médicos Acadêmicos , Pessoal de Saúde , Humanos , Imunoglobulina G , Prevalência , Estudos Prospectivos , Atenção Terciária à Saúde
8.
Thromb Update ; 5: 100086, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38620810

RESUMO

Since the beginning of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) virus pandemic, several highly effective and safe vaccines have been produced at remarkable speed. Following global implementation of vaccination programmes, cases of thrombosis with thrombocytopenia following administration of adenoviral vector-based vaccines started being reported. In this review we discuss the known pathogenesis and epidemiology of so-called vaccine induced thrombocytopenia and thrombosis (VITT). We consider the available guidelines, diagnostic laboratory tests and management options for these patients. Finally, we discuss important unanswered questions and areas for future research in this novel pathoclinical entity.

9.
medRxiv ; 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33330888

RESUMO

BACKGROUND: Following COVID-19 exposure, the CDC recommends a 10-14 day quarantine for asymptomatic individuals and more recently a 7 day quarantine with a negative PCR test. We performed a university-based prospective student cohort study to determine if early PCR negativity predicts day 14 negativity. METHODS: We enrolled 101 asymptomatic, quarantining, students, performed nasopharyngeal swabs for viral testing on days 3 or 4, 5, 7, 10 and 14 and determined the proportion of concordant negative results for each day versus day 14 with a two-sided 95% exact binomial confidence interval. RESULTS: Overall, 14 of 90 (16%, 95% CI: 9% - 25%) tested positive while in quarantine, with 7 initial positive tests on day 3 or 4, 5 on day 5, 2 on day 7, and none on day 10 or 14. Rates of concordant negative test results are: day 5 vs. day 14 = 45/50 (90%, 95% CI: 78% - 97%); day 7 vs. day 14 = 47/52 (90%, 95% CI: 79% - 97%); day 10 vs. day 14 = 48/53 (91%, 95% CI:79% - 97%), with no evidence of different negative rates between earlier days and day 14 by McNemar's test, p > 0.05. CONCLUSIONS: The 16% positive rate supports the ongoing need to quarantine close contacts of COVID-19 cases, but this prospective study provides the first direct evidence that exposed asymptomatic students ages 18-44 years in a university setting are at low risk if released from quarantine at 7 days if they test negative PCR test prior to release.

10.
Phys Rev Lett ; 125(15): 155002, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33095639

RESUMO

We present experimental results from the first systematic study of performance scaling with drive parameters for a magnetoinertial fusion concept. In magnetized liner inertial fusion experiments, the burn-averaged ion temperature doubles to 3.1 keV and the primary deuterium-deuterium neutron yield increases by more than an order of magnitude to 1.1×10^{13} (2 kJ deuterium-tritium equivalent) through a simultaneous increase in the applied magnetic field (from 10.4 to 15.9 T), laser preheat energy (from 0.46 to 1.2 kJ), and current coupling (from 16 to 20 MA). Individual parametric scans of the initial magnetic field and laser preheat energy show the expected trends, demonstrating the importance of magnetic insulation and the impact of the Nernst effect for this concept. A drive-current scan shows that present experiments operate close to the point where implosion stability is a limiting factor in performance, demonstrating the need to raise fuel pressure as drive current is increased. Simulations that capture these experimental trends indicate that another order of magnitude increase in yield on the Z facility is possible with additional increases of input parameters.

13.
Front Immunol ; 10: 2470, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681336

RESUMO

Allogeneic hematopoietic stem cell transplant (allo-HSCT) is often used to treat acute leukemia or defects of hematopoiesis. Its widespread use is hampered by graft-vs.-host disease (GVHD), which has high morbidity and mortality in both acute and chronic subtypes. Chronic GVHD (cGVHD) occurs most frequently in skin and often is characterized by pathogenic fibrosis. Mast cells (MCs) are known to be involved in the pathogenesis of other fibrotic diseases. In a murine model of cGVHD after allo-HSCT, C57BL/6J recipients of allogeneic LP/J donor cells develop sclerodermatous dermal cGVHD which is significantly decreased in mast cell-deficient B6.Cg-KitW-sh/HNihrJaeBsmGlliJ recipients. The presence of MCs is associated with fibrosis, chemokine production, and recruitment of GVHD effector cells to the skin. Chemokine production by MCs is blocked by drugs used to treat cGVHD. The importance of MCs in skin cGVHD is mirrored by increased MCs in the skin of patients with dermal cGVHD. We show for the first time a role for MCs in skin cGVHD that may be targetable for preventive and therapeutic intervention in this disease.


Assuntos
Citocinas/imunologia , Doença Enxerto-Hospedeiro/imunologia , Transplante de Células-Tronco Hematopoéticas/métodos , Mastócitos/imunologia , Pele/imunologia , Adulto , Animais , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Feminino , Fibrose , Perfilação da Expressão Gênica/métodos , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Masculino , Mastócitos/citologia , Mastócitos/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Pele/metabolismo , Pele/patologia , Transplante Homólogo
14.
J Pediatr Urol ; 15(5): 552.e1-552.e8, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31326328

RESUMO

BACKGROUND: Intravesical botulinum toxin A (BtA) injection is well established in managing paediatric neuropathic detrusor overactivity (NDO). Electromotive drug administration (EMDA) is a less invasive method, which can be performed in the clinic, using pulsed electrical current for drug delivery via a urethral catheter. Few small studies report good outcomes following BtA via EMDA (BtA/EMDA) into bladders of children with NDO. OBJECTIVE: The objective of this study is to assess the efficacy of BtA/EMDA in children with NDO, reduced bladder capacity and compliance. METHODS: Twelve children with NDO on baseline urodynamic study were prospectively included. Pre-BtA/EMDA and post-BtA/EMDA results compared the following four parameters: maximal cystometric capacity, bladder compliance, maximal detrusor pressure (pDetmax) during detrusor overactivity and pDetmax at capacity. The Wilcoxon matched-pairs signed-rank test using Graphpad Prism 8 was used for analysis. Secondary outcomes include adverse effects and symptomatic improvement. RESULTS: Fourteen episodes of BtA/EMDA were performed. Five patients received 3.3 IU/kg of Botox®, and five received 10 IU/kg (maximum 300 IU). Four patients received 10 IU/kg of Dysport®. Two patients in the Dysport®/EMDA group also received Botox®/EMDA more than six months previously. Thirteen of 14 post-EMDA results were completed and included in the paired analysis. No statistically significant improvements in any cystometric parameters were demonstrated. Eight patients subsequently had intravesical BtA injections with significant improvements in both cystometric parameters and symptoms. Two patients subsequently transitioned to adult services; one was commenced on mirabegron, and one has undergone ileocystoplasty with Mitrofanoff appendicovesicostomy. DISCUSSION: Despite some evidence to support BtA/EMDA in children with NDO, the authors were unable to replicate previously published positive cystometric and symptomatic outcomes. In addition, BtA/EMDA performed poorly when compared with conventional intravesical BtA injections. This implies failure of EMDA to deliver BtA correctly to the target tissue. The large size of the BtA molecule or the abnormal bladder wall in NDO could account for the negative results. Thorough preparation and consultation was undertaken before this study with BtA/EMDA, and it is discouraging that the authors were unable to reproduce the positive results of other groups. CONCLUSIONS: Although safe and acceptable to most patients, the authors cannot recommend the use of BtA/EMDA for NDO in children at present.


Assuntos
Toxinas Botulínicas Tipo A/administração & dosagem , Bexiga Urinaria Neurogênica/tratamento farmacológico , Bexiga Urinária Hiperativa/tratamento farmacológico , Urodinâmica/fisiologia , Criança , Pré-Escolar , Feminino , Humanos , Injeções Intramusculares , Masculino , Fármacos Neuromusculares/administração & dosagem , Projetos Piloto , Resultado do Tratamento , Bexiga Urinária , Bexiga Urinaria Neurogênica/fisiopatologia , Bexiga Urinária Hiperativa/fisiopatologia
15.
Int J Cardiol ; 258: 1-6, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29544918

RESUMO

OBJECTIVE: We investigated smoking cessation rates in coronary heart disease (CHD) patients throughout Europe; current and as compared to earlier EUROASPIRE surveys, and we studied characteristics of successful quitters. METHODS: Analyses were done on 7998 patients from the EUROASPIRE-IV survey admitted for myocardial infarction, unstable angina and coronary revascularisation. Self-reported smoking status was validated by measuring carbon monoxide in exhaled air. RESULTS: Thirty-one percent of the patients reported being a smoker in the month preceding hospital admission for the recruiting event, varying from 15% in centres from Finland to 57% from centres in Cyprus. Smoking rates at the interview were also highly variable, ranging from 7% to 28%. The proportion of successful quitters was relatively low in centres with a low number of pre- event smokers. Overall, successful smoking cessation was associated with increasing age (OR 1.50; 95% CI 1.09-2.06) and higher levels of education (OR 1.38; 95% CI 1.08-1.75). Successful quitters more frequently reported that they had been advised (56% vs. 47%, p < .001) and to attend (81% vs. 75%, p < .01) a cardiac rehabilitation programme. CONCLUSION: Our study shows wide variation in cessation rates in a large contemporary European survey of CHD patients. Therefore, smoking cessation rates in patients with a CHD event should be interpreted in the light of pre-event smoking prevalence, and caution is needed when comparing cessation rates across Europe. Furthermore, we found that successful quitters reported more actions to make healthy lifestyle changes, including participating in a cardiac rehabilitation programme, as compared with persistent smokers.


Assuntos
Doença das Coronárias/epidemiologia , Doença das Coronárias/terapia , Sistema de Registros , Abandono do Hábito de Fumar/métodos , Inquéritos e Questionários , Idoso , Estudos Transversais , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fumar/epidemiologia , Fumar/terapia , Fumar/tendências
16.
Rev Sci Instrum ; 88(10): 103503, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29092482

RESUMO

Many experiments on Sandia National Laboratories' Z Pulsed Power Facility-a 30 MA, 100 ns rise-time, pulsed-power driver-use a monochromatic quartz crystal backlighter system at 1.865 keV (Si Heα) or 6.151 keV (Mn Heα) x-ray energy to radiograph an imploding liner (cylindrical tube) or wire array z-pinch. The x-ray source is generated by the Z-Beamlet laser, which provides two 527-nm, 1 kJ, 1-ns laser pulses. Radiographs of imploding, thick-walled beryllium liners at convergence ratios CR above 15 [CR=ri(0)/ri(t)] using the 6.151-keV backlighter system were too opaque to identify the inner radius ri of the liner with high confidence, demonstrating the need for a higher-energy x-ray radiography system. Here, we present a 7.242 keV backlighter system using a Ge(335) spherical crystal with the Co Heα resonance line. This system operates at a similar Bragg angle as the existing 1.865 keV and 6.151 keV backlighters, enhancing our capabilities for two-color, two-frame radiography without modifying the system integration at Z. The first data taken at Z include 6.2-keV and 7.2-keV two-color radiographs as well as radiographs of low-convergence (CR about 4-5), high-areal-density liner implosions.

17.
Heart ; 103(11): 840-847, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28255098

RESUMO

BACKGROUND: National guidance for England recommends that cardiovascular disease (CVD) should be managed as a family of diseases in the community. Here, we describe the results of such an approach. METHODS: Patients with established CVD or who were at high multifactorial risk (HRI) underwent a 12-week community-based nurse-led prevention programme (MyAction) that included lifestyle and risk factor management, prescription of medication and weekly exercise and education sessions. RESULTS: Over a 6-year period, 3232 patients attended an initial assessment; 63% were male, and 48% belonged to black and minority ethnic groups. 56% attended an end-of-programme assessment, and 33% attended a one year assessment. By the end of the programme, there was a significant reduction in smoking prevalence but only in HRI (-3.7%, p<0.001). Mediterranean diet score increased in both CVD (+1.2, p<0.001) and HRI (+1.5; p<0.001), as did fitness levels (CVD +0.8 estimated Mets maximum, p<0.001, HRI +0.9 estimated Mets maximum, p<0.001) and the proportions achieving their physical activity targets (CVD +40%, p<0.001, HRI +37%, p<0.001). There were significant increases in proportions achieving their blood pressure (CVD +15.4%, p<0.001, HRI +25%, p<0.001 and low-density lipoprotein cholesterol targets (CVD +6%, p=0.004, HRI +23%, p<0.001). Statins and antihypertensive medications significantly increased in HRI. Significant improvements in depression scores and quality-of-life measures were also seen. The majority of improvements were maintained at 1 year. CONCLUSION: These results demonstrate that an integrated vascular prevention programme is feasible in practice and reduces cardiovascular risk in patients with established CVD and in those at high multifactorial risk.


Assuntos
Reabilitação Cardíaca/enfermagem , Doenças Cardiovasculares/prevenção & controle , Serviços de Saúde Comunitária/métodos , Estilo de Vida , Cooperação do Paciente , Avaliação de Programas e Projetos de Saúde/métodos , Comportamento de Redução do Risco , Doenças Cardiovasculares/enfermagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
18.
Phys Rev Lett ; 116(6): 065001, 2016 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-26918996

RESUMO

Enhanced implosion stability has been experimentally demonstrated for magnetically accelerated liners that are coated with 70 µm of dielectric. The dielectric tamps liner-mass redistribution from electrothermal instabilities and also buffers coupling of the drive magnetic field to the magneto-Rayleigh-Taylor instability. A dielectric-coated and axially premagnetized beryllium liner was radiographed at a convergence ratio [CR=Rin,0/Rin(z,t)] of 20, which is the highest CR ever directly observed for a strengthless magnetically driven liner. The inner-wall radius Rin(z,t) displayed unprecedented uniformity, varying from 95 to 130 µm over the 4.0 mm axial height captured by the radiograph.

19.
Equine Vet J ; 48(1): 83-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25297461

RESUMO

REASONS FOR PERFORMING STUDY: Lungeing is often part of the clinical lameness examination. The difference in movement symmetry, which is a commonly employed lameness measure, has not been quantified between surfaces. OBJECTIVES: To compare head and pelvic movement symmetry between surfaces and reins during lungeing. STUDY DESIGN: Quantitative gait analysis in 23 horses considered sound by their owners. METHODS: Twenty-three horses were assessed in-hand and on the lunge on both reins on hard and soft surfaces with inertial sensors. Seven movement symmetry parameters were quantified and used to establish 2 groups, namely symmetrical (n = 9) and forelimb-lame horses (n = 14), based on values from straight-line assessment. Movement symmetry values for left rein measurements were side corrected to allow comparison of the amount of movement symmetry between reins. A mixed model (P<0.05) was used to study effects on movement symmetry of surface (hard/soft) and rein (inside/outside with respect to movement symmetry on the straight). RESULTS: In forelimb-lame horses, surface and rein were identified as significantly affecting all head movement symmetry measures (rein, all P<0.0001; surface, all P<0.042). In the symmetrical group, no significant influence of surface or rein was identified for head movement symmetry (rein, all P>0.245; surface, all P>0.073). No significant influence of surface or rein was identified for any of the pelvic movement symmetry measures in either group. CONCLUSIONS: While more symmetrical horses showed a consistent amount of movement symmetry across surfaces/reins, horses objectively quantified as lame on the straight showed decreased movement symmetry during lungeing, in particular with the lame limb on the inside of a hard circle. The variation within group questions straight-line movement symmetry as a sole measure of lameness without quantification of movement symmetry on the lunge, ideally on hard and soft surfaces to evaluate differences between reins and surfaces. In future, thresholds for lungeing need to be determined using simultaneous visual and objective assessment.


Assuntos
Marcha , Cavalos/fisiologia , Movimento , Animais , Fenômenos Biomecânicos , Cabeça/fisiologia , Monitorização Ambulatorial , Tronco/fisiologia
20.
Br J Cancer ; 113(1): 69-75, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26057448

RESUMO

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare and essentially incurable malignancy most often linked with occupational exposure to asbestos fibres. In common with other malignancies, the development and progression of MPM is associated with extensive dysregulation of cell cycle checkpoint proteins that modulate cell proliferation, apoptosis, DNA repair and senescence. METHODS: The expression of cyclin-dependent kinase inhibitor p16/INK4A was evaluated by immunohistochemistry using tumour biopsy specimens from 88 MPM cases and a semi-quantitative score for p16/INK4A expression was obtained. Post-diagnosis survival and the survival benefit of chemotherapeutic intervention was correlated with p16/INK4A expression. RESULTS: A low, intermediate and high score for p16/INK4A expression was observed for 45 (51.1%), 28 (31.8%) and 15 (17.1%) of the MPM cases, respectively. Those cases with intermediate or high p16/INK4A tumour expression had a significantly better post-diagnosis survival than those cases whose tumours lost p16 expression (log-rank P<0.001). Those patients with sustained p16/INK4A expression who received chemotherapy also had a better survival than those treated patients whose tumours had lost p16/INK4A expression (log-rank P<0.001). CONCLUSIONS: Sustained p16/INK4A expression predicts better post-diagnosis survival in MPM and also better survival following chemotherapeutic intervention.


Assuntos
Proteínas Inibidoras de Quinase Dependente de Ciclina/metabolismo , Mesotelioma/tratamento farmacológico , Neoplasias Pleurais/tratamento farmacológico , Linhagem Celular Tumoral , Estudos de Coortes , Humanos , Mesotelioma/metabolismo , Mesotelioma/patologia , Neoplasias Pleurais/metabolismo , Neoplasias Pleurais/patologia
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