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1.
PLoS One ; 16(2): e0246123, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33577565

RESUMEN

BACKGROUND: Nasal High Flow (NHF) therapy delivers flows of heated humidified gases up to 60 LPM (litres per minute) via a nasal cannula. Particles of oral/nasal fluid released by patients undergoing NHF therapy may pose a cross-infection risk, which is a potential concern for treating COVID-19 patients. METHODS: Liquid particles within the exhaled breath of healthy participants were measured with two protocols: (1) high speed camera imaging and counting exhaled particles under high magnification (6 participants) and (2) measuring the deposition of a chemical marker (riboflavin-5-monophosphate) at a distance of 100 and 500 mm on filter papers through which air was drawn (10 participants). The filter papers were assayed with HPLC. Breathing conditions tested included quiet (resting) breathing and vigorous breathing (which here means nasal snorting, voluntary coughing and voluntary sneezing). Unsupported (natural) breathing and NHF at 30 and 60 LPM were compared. RESULTS: Imaging: During quiet breathing, no particles were recorded with unsupported breathing or 30 LPM NHF (detection limit for single particles 33 µm). Particles were detected from 2 of 6 participants at 60 LPM quiet breathing at approximately 10% of the rate caused by unsupported vigorous breathing. Unsupported vigorous breathing released the greatest numbers of particles. Vigorous breathing with NHF at 60 LPM, released half the number of particles compared to vigorous breathing without NHF.Chemical marker tests: No oral/nasal fluid was detected in quiet breathing without NHF (detection limit 0.28 µL/m3). In quiet breathing with NHF at 60 LPM, small quantities were detected in 4 out of 29 quiet breathing tests, not exceeding 17 µL/m3. Vigorous breathing released 200-1000 times more fluid than the quiet breathing with NHF. The quantities detected in vigorous breathing were similar whether using NHF or not. CONCLUSION: During quiet breathing, 60 LPM NHF therapy may cause oral/nasal fluid to be released as particles, at levels of tens of µL per cubic metre of air. Vigorous breathing (snort, cough or sneeze) releases 200 to 1000 times more oral/nasal fluid than quiet breathing (p < 0.001 with both imaging and chemical marker methods). During vigorous breathing, 60 LPM NHF therapy caused no statistically significant difference in the quantity of oral/nasal fluid released compared to unsupported breathing. NHF use does not increase the risk of dispersing infectious aerosols above the risk of unsupported vigorous breathing. Standard infection prevention and control measures should apply when dealing with a patient who has an acute respiratory infection, independent of which, if any, respiratory support is being used. CLINICAL TRIAL REGISTRATION: ACTRN12614000924651.


Asunto(s)
Espiración , Terapia por Inhalación de Oxígeno/efectos adversos , Terapia por Inhalación de Oxígeno/métodos , Adulto , Pruebas Respiratorias/métodos , COVID-19/terapia , Cánula , Femenino , Humanos , Masculino , Microscopía por Video , Nariz/química , Respiración , Frecuencia Respiratoria
2.
Nat Commun ; 11(1): 1097, 2020 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-32107369

RESUMEN

Manipulating the surface energy, and thereby the wetting properties of solids, has promise for various physical, chemical, biological and industrial processes. Typically, this is achieved by either chemical modification or by controlling the hierarchical structures of surfaces. Here we report a phenomenon whereby the wetting properties of vermiculite laminates are controlled by the hydrated cations on the surface and in the interlamellar space. We find that vermiculite laminates can be tuned from superhydrophilic to hydrophobic simply by exchanging the cations; hydrophilicity decreases with increasing cation hydration free energy, except for lithium. The lithium-exchanged vermiculite laminate is found to provide a superhydrophilic surface due to its anomalous hydrated structure at the vermiculite surface. Building on these findings, we demonstrate the potential application of superhydrophilic lithium exchanged vermiculite as a thin coating layer on microfiltration membranes to resist fouling, and thus, we address a major challenge for oil-water separation technology.

3.
Public Health ; 180: 129-135, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31887609

RESUMEN

OBJECTIVES: The aim of the Scottish AHP LifeCurve™ survey was to gather a snapshot of where people are on their LifeCurve™ when receiving allied health professions (AHP) services and to understand the cost consequence of intervening 'late' in the ageing trajectory. The objectives were to promote discussion around preventing functional decline, support innovation in service delivery, and facilitate broader engagement with individuals, communities, and wider environments for improving health and well-being in later life. In addition, subsequent learning could help address the increasing resource gap between the demand and capacity across health and social care. STUDY DESIGN: The survey was paper-based in the form of a printed booklet, which contained the 15 activities of daily living (ADL) and instrumental ADL (IADL) which comprise the LifeCurve™ with additional lifestyle questions and information about the member of staff and service the participant was seen in, including their Community Health Index (CHI) number. The survey questions and booklet layout were tested over a five-month period with AHPs and people receiving AHP services. Liaison with national health literacy colleagues and lead speech and language therapists ensured that the survey material was accessible to a wide range of people. In addition, the survey could be made available in alternative formats, on request. METHODS: Agreement to undertake the national survey was obtained in November 2016 by all AHP directors and associate directors who appointed communication support leads in their area who would support implementation at all stages at a local level. All materials relating to the survey were published on a dedicated area of a community of practice to support awareness and training during the preimplementation phase. AHPs working in adult services were asked to complete a survey with a minimum of two people they would 'typically' see in their service during a two-week period in May 2017, with the exclusion of people who were too unwell to participate, children and young people under 16 years, and adults with incapacity and without a guardianship arrangement in place. Approval was gained from the Public Benefit Privacy Panel to link the survey data to participants' health service usage using their CHI number. Completed forms were returned to the University of Strathclyde for entry into an encrypted electronic database using a double data entry process and were allocated a unique identifier. The unique identifier and CHI numbers were sent to Information Services Division (ISD), and then, the CHI numbers were deleted from the encrypted database. ISD sent the linked health data to the Scottish Government Analytical Services Division, which thus produced a full encrypted and anonymised database. RESULTS: The data explain what stages on the LifeCurve™ AHPs are intervening, and the matched data provide associated healthcare costs at each stage. Due to poor or missing data in the AHP/Service section, only 60% (n = 8261) of the total completed surveys were able to be matched with health service usage records. These data show that whilst AHPs are seeing people at each of the 15 ADL/IADL stages on the LifeCurve™, interventions fell into three groups where 25% of people where seen at the 'precurve' stage, 13% of people at 'mid-curve' (stage number five), and 39% of people at 'late-curve' (stages 10 to 13). The healthcare cost usage of these participants increased the further along the LifeCurve™ a person moves, with an average annual cost of £2700 at 'precurve' rising to £12,330 at 'late-curve' in 2016-2017. The results indicate that different services and professions are represented at each of these three points. So, for example, as might be expected, outpatient (especially musculoskeletal) services were seen more often at the 'precurve' stage, and in-patient and community rehabilitation, services were seen more often at the 'late-curve' stages; diagnostic radiographers and orthoptists saw people at the 'early-curve' stages, dieticians and podiatrists saw people at the 'mid-curve' stage, whilst physiotherapists, speech and language therapists, and occupational therapists saw people at the 'late-curve' stages. Data analysis showed this pattern is different for people receiving mental health services and, so, their data were removed and will be analysed and reported separately. CONCLUSIONS: It is clear from the results that healthcare costs increased as participants moved down LifeCurve™ stages, that is, as their levels of functional decline increase. It is also clear that AHPs are intervening late in a person's functional decline with associated limitations on changing their ageing trajectory. The cost consequence of this is significant - moving someone from 'late- to mid-curve' could save £3200 per person per annum. However, those AHPs typically associated with reabling approaches and rehabilitation, which have greatest potential to change ageing trajectories, were not represented at the 'mid-curve' stage (e.g., physiotherapists, occupational therapists). Therefore, we must find places to have conversations with people to inform them that functional decline is malleable and not inevitable purely by virtue of chronological age and provide education and support to prevent or reverse functional decline and collaborate around strategic planning and commissioning to offer different options that support an optimum LifeCurve™.


Asunto(s)
Actividades Cotidianas , Envejecimiento/fisiología , Encuestas y Cuestionarios , Costos y Análisis de Costo , Promoción de la Salud/métodos , Humanos , Uso Significativo , Escocia
4.
Med Eng Phys ; 72: 66-69, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31554578

RESUMEN

This editorial pays tribute to the work of Professor John P. Paul and his team at the University of Strathclyde in the 1960s and '70s, and subsequently by the Strathclyde Rehabilitation Engineering Group, as featured in the journal Medical Engineering & Physics. It also includes a consideration of the nature of full biomechanical analysis of movement and how it can be mathematically modelled and physically recorded, the different approaches taken by Paul's and Winter's groups, respectively, and what a full biomechanical model should include in the future. The article also attempts to signpost the reader to future developments in the field, and how the techniques pioneered by Paul in the 1960s may influence Clinical Biomechanics and Rehabilitation in the years to come.


Asunto(s)
Ingeniería/historia , Fenómenos Biomecánicos , Historia del Siglo XX , Historia del Siglo XXI , Humanos
5.
Med Biol Eng Comput ; 56(12): 2325-2335, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29946955

RESUMEN

Perturbation-based gait assessment has been used to quantify gait stability in older adults. However, knowledge on which perturbation type is most suitable to identify poor gait stability is lacking. We evaluated the effects of ipsi- and contra-lateral sway, belt acceleration and deceleration, and visual and auditory perturbations on medio-lateral (ML) and anterior-posterior (AP) margins of stability (MoS) in young and older adults. We aimed to evaluate (1) which perturbation type disturbed the gait pattern substantially, (2) how participants recovered, and (3) whether recovery responses could discriminate between young and older adults. Nine young (25.1 ± 3.4 years) and nine older (70.1 ± 7.6 years) adults walked on the CAREN Extended (Motek BV, The Netherlands). The perturbation effect was quantified by deviation in MoS over six post-perturbation steps compared to baseline walking. Contra-lateral sway and deceleration perturbations resulted in the largest ML (1.9-4 times larger than other types) and AP (1.6-5.6 times larger than other types) perturbation effects, respectively. After both perturbation types, participants increased MoS by taking wider, shorter, and faster steps. No differences between young and older adults were found. We suggest to evaluate the potential of using contra-lateral sway and deceleration perturbations for fall risk identification by including both healthy and frail older adults. Graphical abstract Margins of stability during steady state (left) and perturbed (right) gait to quantify reactive gait stability in response to various perturbation types in young and older adults.


Asunto(s)
Prueba de Esfuerzo/instrumentación , Prueba de Esfuerzo/métodos , Marcha/fisiología , Accidentes por Caídas/prevención & control , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Equilibrio Postural/fisiología , Análisis Espacio-Temporal , Caminata/fisiología
6.
BMC Musculoskelet Disord ; 19(1): 140, 2018 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-29743063

RESUMEN

BACKGROUND: A structured approach to perioperative patient management based on an enhanced recovery pathway protocol facilitates early recovery and reduces morbidity in high income countries. However, in low- and middle-income countries (LMICs), the feasibility of implementing enhanced recovery pathways and its influence on patient outcomes is scarcely investigated. To inform similar practice in LMICs for total hip and knee arthroplasty, it is necessary to identify potential factors for inclusion in such a programme, appropriate for LMICs. METHODS: Applying a Delphi method, 33 stakeholders (13 arthroplasty surgeons, 12 anaesthetists and 8 physiotherapists) from 10 state hospitals representing 4 South African provinces identified and prioritised i) risk factors associated with poor outcomes, ii) perioperative interventions to improve outcomes and iii) patient and clinical outcomes necessary to benchmark practice for patients scheduled for primary elective unilateral total hip and knee arthroplasty. RESULTS: Thirty of the thirty-three stakeholders completed the 3 months Delphi study. The first round yielded i) 36 suggestions to preoperative risk factors, ii) 14 (preoperative), 18 (intraoperative) and 23 (postoperative) suggestions to best practices for perioperative interventions to improve outcomes and iii) 25 suggestions to important postsurgical outcomes. These items were prioritised by the group in the consecutive rounds and consensus was reached for the top ten priorities for each category. CONCLUSION: The consensus derived risk factors, perioperative interventions and important outcomes will inform the development of a structured, perioperative multidisciplinary enhanced patient care protocol for total hip and knee arthroplasty. It is anticipated that this study will provide the construct necessary for developing pragmatic enhanced care pathways aimed at improving patient outcomes after arthroplasty in LMICs.


Asunto(s)
Artroplastia de Reemplazo de Cadera/normas , Artroplastia de Reemplazo de Rodilla/normas , Consenso , Técnica Delfos , Personal de Salud/normas , Atención Perioperativa/normas , Artroplastia de Reemplazo de Cadera/métodos , Artroplastia de Reemplazo de Rodilla/métodos , Humanos , Atención Perioperativa/métodos , Sudáfrica/epidemiología
7.
J Dent Res ; 97(2): 184-191, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28880715

RESUMEN

X-linked hypophosphatemia (XLH) is a skeletal disease caused by inactivating mutations in the PHEX gene. Mutated or absent PHEX protein/enzyme leads to a decreased serum phosphate level, which cause mineralization defects in the skeleton and teeth (osteomalacia/odontomalacia). It is not yet altogether clear whether these manifestations are caused solely by insufficient circulating phosphate availability for mineralization or also by a direct, local intrinsic effect caused by impaired PHEX activity. Here, we evaluated the local role of PHEX in a 3-dimensional model of extracellular matrix (ECM) mineralization. Dense collagen hydrogels were seeded either with human dental pulp cells from patients with characterized PHEX mutations or with sex- and age-matched healthy controls and cultured up to 24 d using osteogenic medium with standard phosphate concentration. Calcium quantification, micro-computed tomography, and histology with von Kossa staining for mineral showed significantly lower mineralization in XLH cell-seeded scaffolds, using nonparametric statistical tests. While apatitic mineralization was observed along collagen fibrils by electron microscopy in both groups, Raman microspectrometry indicated that XLH cells harboring the PHEX mutation produced less mineralized scaffolds having impaired mineral quality with less carbonate substitution and lower crystallinity. In the XLH cultures, immunoblotting revealed more abundant osteopontin (OPN), dentin matrix protein 1 (DMP1), and matrix extracellular phosphoglycoprotein (MEPE) than controls, as well as the presence of fragments of these proteins not found in controls, suggesting a role for PHEX in SIBLING protein degradation. Immunohistochemistry revealed altered OPN and DMP1 associated with an increased alkaline phosphatase staining in the XLH cultures. These results are consistent with impaired PHEX activity having local ECM effects in XLH. Future treatments for XLH should target both systemic and local manifestations.


Asunto(s)
Raquitismo Hipofosfatémico Familiar/genética , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Endopeptidasa Neutra Reguladora de Fosfato PHEX/genética , Desmineralización Dental/genética , Adolescente , Calcio/análisis , Células Cultivadas , Niño , Matriz Extracelular/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Glicoproteínas/metabolismo , Humanos , Immunoblotting , Inmunohistoquímica , Microscopía Electrónica de Rastreo , Osteopontina/metabolismo , Fenotipo , Fosfoproteínas/metabolismo , Reacción en Cadena de la Polimerasa , Espectrometría Raman , Andamios del Tejido , Diente Primario , Microtomografía por Rayos X
8.
JIMD Rep ; 42: 19-29, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29159459

RESUMEN

Vici syndrome is a rare, under-recognised, relentlessly progressive congenital multisystem disorder characterised by five principal features of callosal agenesis, cataracts, cardiomyopathy, combined immunodeficiency and oculocutaneous hypopigmentation. In addition, three equally consistent features (profound developmental delay, progressive failure to thrive and acquired microcephaly) are highly supportive of the diagnosis. Since its recognition as a distinct entity in 1988, an extended phenotype with sensorineural hearing loss, skeletal myopathy and variable involvement of virtually any organ system, including the lungs, thyroid, liver and kidneys, have been described.Autosomal recessive mutations in EPG5 encoding ectopic P-granules autophagy protein 5 (EPG5), a key autophagy regulator implicated in the formation of autolysosomes, were identified as the genetic cause of Vici syndrome. The eight key features outlined above are highly predictive of EPG5 involvement, with pathogenic EPG5 mutations identified in >90% of cases where six or more of these features are present. The manifestation of all eight features has a specificity of 97% and sensitivity of 89% for EPG5-related Vici syndrome. Nevertheless, substantial clinical overlap exists with other multisystem disorders, in particular congenital disorders of glycosylation and mitochondrial disorders. Clinical and pathological findings suggest Vici syndrome as a paradigm of congenital disorders of autophagy, a novel group of inherited neurometabolic conditions linking neurodevelopment and neurodegeneration due to primary autophagy defects.Here we describe the diagnostic odyssey in a 4-year-old boy whose clinical presentation with multisystem manifestations including skeletal myopathy mimicked a mitochondrial disorder. A genetic diagnosis of Vici syndrome was made through whole genome sequencing which identified compound heterozygous variants in EPG5. We also review the myopathic presentation and morphological characterisation of previously reported cases.

9.
Rhinology ; 55(4): 298-304, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-29166426

RESUMEN

The first Rhinology Future Debates was held in Brussels in December 2016, organized by EUFOREA (European Forum for Research and Education in Allergy and Airways diseases). The purpose of these debates is to bring novel developments in the field of Rhinology to the attention of the medical, paramedical and patient community, in a highly credible and balanced context. For the first time in Rhinology, a peer to peer scientific exchange with key experts in the field of rhinology and key medical colleagues from leading industries let to a brainstorming and discussion event on a number of hot issues in Rhinology. Novel developments are presented by key experts from industry and/or key thought leaders in Rhinology, and then followed by a lively debate on the potential positioning of new developments in care pathways, the strengths and weaknesses of the novel development(s), and comparisons with existing and/or competing products, devices, and/or molecules. As all debates are recorded and distributed on-line with limited editing (www.rhinology-future.com), EUFOREA aims at maximizing the education of the target groups on novel developments, allowing a critical appraisal of the future and a more rapid implementation of promising novel tools, techniques and/or molecules in clinical practise in Europe. The next Rhinology Future debate will be held in Brussels in December 2017.


Asunto(s)
Rinitis/terapia , Sinusitis/terapia , Antiasmáticos/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados , Enfermedad Crónica , Congresos como Asunto , Dilatación/instrumentación , Implantes de Medicamentos , Glucocorticoides/administración & dosificación , Humanos , Otolaringología , Cirugía Asistida por Computador
10.
Bone Joint Res ; 6(11): 631-639, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29162608

RESUMEN

OBJECTIVES: This study reports on a secondary exploratory analysis of the early clinical outcomes of a randomised clinical trial comparing robotic arm-assisted unicompartmental knee arthroplasty (UKA) for medial compartment osteoarthritis of the knee with manual UKA performed using traditional surgical jigs. This follows reporting of the primary outcomes of implant accuracy and gait analysis that showed significant advantages in the robotic arm-assisted group. METHODS: A total of 139 patients were recruited from a single centre. Patients were randomised to receive either a manual UKA implanted with the aid of traditional surgical jigs, or a UKA implanted with the aid of a tactile guided robotic arm-assisted system. Outcome measures included the American Knee Society Score (AKSS), Oxford Knee Score (OKS), Forgotten Joint Score, Hospital Anxiety Depression Scale, University of California at Los Angeles (UCLA) activity scale, Short Form-12, Pain Catastrophising Scale, somatic disease (Primary Care Evaluation of Mental Disorders Score), Pain visual analogue scale, analgesic use, patient satisfaction, complications relating to surgery, 90-day pain diaries and the requirement for revision surgery. RESULTS: From the first post-operative day through to week 8 post-operatively, the median pain scores for the robotic arm-assisted group were 55.4% lower than those observed in the manual surgery group (p = 0.040).At three months post-operatively, the robotic arm-assisted group had better AKSS (robotic median 164, interquartile range (IQR) 131 to 178, manual median 143, IQR 132 to 166), although no difference was noted with the OKS.At one year post-operatively, the observed differences with the AKSS had narrowed from a median of 21 points to a median of seven points (p = 0.106) (robotic median 171, IQR 153 to 179; manual median 164, IQR 144 to 182). No difference was observed with the OKS, and almost half of each group reached the ceiling limit of the score (OKS > 43). A greater proportion of patients receiving robotic arm-assisted surgery improved their UCLA activity score.Binary logistic regression modelling for dichotomised outcome scores predicted the key factors associated with achieving excellent outcome on the AKSS: a pre-operative activity level > 5 on the UCLA activity score and use of robotic-arm surgery. For the same regression modelling, factors associated with a poor outcome were manual surgery and pre-operative depression. CONCLUSION: Robotic arm-assisted surgery results in improved early pain scores and early function scores in some patient-reported outcomes measures, but no difference was observed at one year post-operatively. Although improved results favoured the robotic arm-assisted group in active patients (i.e. UCLA ⩾ 5), these do not withstand adjustment for multiple comparisons.Cite this article: M. J. G. Blyth, I. Anthony, P. Rowe, M. S. Banger, A. MacLean, B. Jones. Robotic arm-assisted versus conventional unicompartmental knee arthroplasty: Exploratory secondary analysis of a randomised controlled trial. Bone Joint Res 2017;6:631-639. DOI: 10.1302/2046-3758.611.BJR-2017-0060.R1.

11.
Physiotherapy ; 103(3): 259-265, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27107979

RESUMEN

OBJECTIVES: Restoring independence in the sit-to-stand (STS) task is an important objective for stroke rehabilitation. It is not known if a particular intervention, strength training or therapy focused on movement performance is more likely to improve STS recovery. This study aimed to compare STS outcomes from functional strength training, movement performance therapy and conventional therapy. DESIGN: Randomised controlled trial. SETTING: Acute stroke units. PARTICIPANTS: Medically well patients (n=93) with recent (<42 days) stroke. The mean age of patients was 68.8 years, mean time post ictus was 33.5 days, 54 (58%) were male, 20 showed neglect (22%) and 37 (40%) had a left-sided brain lesion. INTERVENTIONS: Six weeks of either conventional therapy, functional strength training or movement performance therapy. Subjects were allocated to groups on a random basis. MAIN OUTCOME MEASURES: STS ability, timing, symmetry, co-ordination, smoothness and knee velocity were measured at baseline, outcome (after 6 weeks of intervention) and follow-up (3 months after outcome). RESULTS: No significant differences were found between the groups. All three groups improved their STS ability, with 88% able to STS at follow-up compared with 56% at baseline. Few differences were noted in quality of movement, with only symmetry when rising showing significantly greater improvement in the movement performance therapy group; this benefit was not evident at follow-up. CONCLUSIONS: Recovery of the STS movement is consistently good during stroke rehabilitation, irrespective of the type of therapy experienced. Changes in quality of movement did not differ according to group allocation, indicating that the type of therapy is less important. Clinical trial registration number NCT00322192.


Asunto(s)
Movimiento/fisiología , Entrenamiento de Fuerza/métodos , Rehabilitación de Accidente Cerebrovascular/métodos , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modalidades de Fisioterapia , Postura , Método Simple Ciego
12.
Ultrasonics ; 72: 165-76, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27552482

RESUMEN

Synthetic aperture imaging methods have been employed widely in recent research in non-destructive testing (NDT), but uptake has been more limited in medical ultrasound imaging. Typically offering superior focussing power over more traditional phased array methods, these techniques have been employed in NDT applications to locate and characterise small defects within large samples, but have rarely been used to image surfaces. A desire to ultimately employ ultrasonic surface imaging for bone surface geometry measurement prior to surgical intervention motivates this research, and results are presented for initial laboratory trials of a surface reconstruction technique based on global thresholding of ultrasonic 3D point cloud data. In this study, representative geometry artefacts were imaged in the laboratory using two synthetic aperture techniques; the Total Focusing Method (TFM) and the Synthetic Aperture Focusing Technique (SAFT) employing full and narrow synthetic apertures, respectively. Three high precision metallic samples of known geometries (cuboid, sphere and cylinder) which featured a range of elementary surface primitives were imaged using a 5MHz, 128 element 1D phased array employing both SAFT and TFM approaches. The array was manipulated around the samples using a precision robotic positioning system, allowing for repeatable ultrasound derived 3D surface point clouds to be created. A global thresholding technique was then developed that allowed the extraction of the surface profiles, and these were compared with the known geometry samples to provide a quantitative measure of error of 3D surface reconstruction. The mean errors achieved with optimised SAFT imaging for the cuboidal, spherical and cylindrical samples were 1.3mm, 2.9mm and 2.0mm respectively, while those for TFM imaging were 3.7mm, 3.0mm and 3.1mm, respectively. These results were contrary to expectations given the higher information content associated with the TFM images. However, it was established that the reduced error associated with the SAFT technique was associated with significant reductions in side lobe levels of approximately 24dB in comparison to TFM imaging, although this came at the expense of reduced resolution and coverage.

13.
Sci Rep ; 6: 22457, 2016 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-26932150

RESUMEN

The Atacama Desert has been pointed out as one of the places on earth where the highest surface irradiance may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low columns of ozone and water vapor. Aimed at the characterization of the solar spectrum in the Atacama Desert, we carried out in February-March 2015 ground-based measurements of the spectral irradiance (from the ultraviolet to the near infrared) at seven locations that ranged from the city of Antofagasta (on the southern pacific coastline) to the Chajnantor Plateau (5,100 m altitude). Our spectral measurements allowed us to retrieve the total ozone column, the precipitable water, and the aerosol properties at each location. We found that changes in these parameters, as well as the shorter optical path length at high-altitude locations, lead to significant increases in the surface irradiance with the altitude. Our measurements show that, in the range 0-5100 m altitude, surface irradiance increases with the altitude by about 27% in the infrared range, 6% in the visible range, and 20% in the ultraviolet range. Spectral measurements carried out at the Izaña Observatory (Tenerife, Spain), in Hannover (Germany) and in Santiago (Chile), were used for further comparisons.

14.
Physiotherapy ; 102(4): 327-331, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26725003

RESUMEN

OBJECTIVE: To describe and compare patterns of physical activity among stroke survivors during their hospital stay and community living with early supported discharge. DESIGN: Observational cohort study of physical activity before and after early supported discharge. SETTING: UK National Health Service stroke units and participants' homes. PARTICIPANTS: Forty-one stroke survivors with a mean age of 69 (standard deviation 11) years, and a median Modified Rivermead Mobility Index of 33.5 [interquartile range (IQR) 25.8 to 35.3]. MAIN OUTCOME MEASURES: The primary outcome measures were time spent in sitting/standing/walking and number of steps taken, as recorded by a physical activity monitor. RESULTS: There were statistical differences (P<0.001) for all categories of physical activity. After early supported discharge to the community, participants took more than twice the number of steps {median 474 (IQR 189 to 773) vs. 1193 (IQR 512 to 2856), median difference 636 [95% confidence interval (CI) 262 to 931]} and spent more than double the time in standing [median 51 (IQR 22 to 128) minutes vs. 100 (IQR 51 to 178) minutes, median difference 28 (95% CI 11 to 68)] compared with their hospital stay. CONCLUSION: Community living with early supported discharge promoted higher levels of physical activity in medically stable stroke survivors. The near-doubling of activity may serve as a guideline for what is achievable during stroke rehabilitation. CLINICAL TRIAL REGISTRATION: Number UKCRN 15472.


Asunto(s)
Ejercicio Físico , Pacientes Internos/estadística & datos numéricos , Alta del Paciente/estadística & datos numéricos , Modalidades de Fisioterapia , Rehabilitación de Accidente Cerebrovascular/métodos , Acelerometría , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad
15.
Chem Res Toxicol ; 28(10): 1975-86, 2015 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-26382665

RESUMEN

Many chemicals can induce skin sensitization, and there is a pressing need for non-animal methods to give a quantitative indication of potency. Using two large published data sets of skin sensitizers, we have allocated each sensitizing chemical to one of 10 mechanistic categories and then developed good QSAR models for the seven categories that have a sufficient number of chemicals to allow modeling. Both internal and external validation checks showed that each model had good predictivity.


Asunto(s)
Modelos Teóricos , Relación Estructura-Actividad Cuantitativa , Animales , Compuestos Orgánicos/química , Compuestos Orgánicos/toxicidad , Piel/efectos de los fármacos , Piel/metabolismo
16.
SAR QSAR Environ Res ; 26(6): 439-48, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26034813

RESUMEN

Sulphonylureas are widely used anti-hyperglycaemic drugs for the treatment of type 2 diabetes. The only published quantitative structure-activity relationship (QSAR) models for sulphonylurea drugs have been found to be questionable, for a number of reasons. We have re-analysed the human anti-hyperglycaemic potencies, acute mouse intraperitoneal toxicities (LD50) and plasma protein-binding abilities of the 15 drugs using multiple linear regression and obtained good QSAR models for each endpoint. The obtained QSARs all comply well with the Organisation for Economic Co-operation and Development (OECD) Guidelines for the Validation of (Q)SARs. We could not carry out external validation of our models for acute toxicity and plasma protein-binding because of the very small datasets available.


Asunto(s)
Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Relación Estructura-Actividad Cuantitativa , Compuestos de Sulfonilurea/química , Compuestos de Sulfonilurea/farmacología , Animales , Proteínas Sanguíneas/metabolismo , Humanos , Hipoglucemiantes/toxicidad , Dosificación Letal Mediana , Modelos Lineales , Ratones , Análisis Multivariante , Unión Proteica , Compuestos de Sulfonilurea/toxicidad
17.
Connect Tissue Res ; 55 Suppl 1: 79-82, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25158186

RESUMEN

Mutations in phosphate-regulating gene (PHEX) lead to X-linked hypophosphatemic rickets (XLH), a genetic disease characterized by impaired mineralization in bones and teeth. In human XLH tooth dentin, calcospherites that would normally merge as part of the mineralization process are separated by unmineralized interglobular spaces where fragments of matrix proteins accumulate. Here, we immunolocalized osteopontin (OPN) in human XLH teeth, in a three-dimensional XLH human dental pulp stem cell-collagen scaffold culture model and in a rat tooth injury repair model treated with acidic serine- and aspartate-rich motif peptides (ASARM). In parallel, matrix extracellular phosphoglycoprotein (MEPE) immunolocalization and alkaline phosphatase (ALP) activity were assessed in XLH teeth. OPN was expressed by odontoblasts in the XLH models, and localized to the abnormal calcospherites of XLH tooth dentin. In addition, ALP activity and MEPE localization were abnormal in human XLH teeth, with MEPE showing an accumulation in the unmineralized interglobular spaces in dentin. Furthermore, XLH odontoblasts failed to form a well-polarized odontoblast layer. These data suggest that both MEPE and OPN are involved in impaired tooth mineralization associated with XLH, possibly through different effects on the mineralization process.


Asunto(s)
Calcificación Fisiológica/fisiología , Proteínas de la Matriz Extracelular/metabolismo , Raquitismo Hipofosfatémico Familiar/metabolismo , Glicoproteínas/metabolismo , Odontoblastos/citología , Osteopontina/metabolismo , Fosfoproteínas/metabolismo , Adolescente , Animales , Diferenciación Celular/fisiología , Raquitismo Hipofosfatémico Familiar/genética , Femenino , Humanos , Ratas , Diente/citología , Diente/metabolismo
20.
SAR QSAR Environ Res ; 24(8): 661-78, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23724974

RESUMEN

Many in silico alternatives to aquatic toxicity tests rely on hydrophobicity-based quantitative structure-activity relationships (QSARs). Hydrophobicity is often estimated as log P, where P is the octanol-water partition coefficient. Immobilised artificial membrane (IAM) high performance liquid chromatography (HPLC) may be a more biologically relevant alternative to log P. The aim of this study was to investigate the applicability of a theoretical structural fragment and feature-based method to predict log k IAM (the logarithm of the retention index determined by IAM-HPLC) values. This will allow the prediction of log k IAM based on chemical structure alone. The use of structural fragment values to predict log P was first proposed in the 1970s. The application of a similar method using fragment values to predict log k IAM is a novel approach. Values of log k IAM were determined for 22 aliphatic and 42 aromatic compounds using an optimised and robust IAM-HPLC assay. The method developed shows good predictive performance using leave-one-out cross validation and application to an external validation set not seen a priori by the training set also generated good predictive values. The ability to predict log k IAM without the need for practical measurement will allow for the increased use of QSARs based on this descriptor.


Asunto(s)
Cromatografía Líquida de Alta Presión , Membranas Artificiales , Compuestos Orgánicos/química , Interacciones Hidrofóbicas e Hidrofílicas , Estructura Molecular , Relación Estructura-Actividad Cuantitativa
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