IMECE2009-11857 BIOMECHANICAL BASIS OF OSCILLOMETRIC BLOOD PRESSURE MEASURING TECHNIQUE

ABSTRACT Non-invasive blood pressure (BP) measurement has been used clinically for over a century to diagnose hypertension. Compared with the auscultatory technique, the oscillometric technique requires less professional training and is widely used in automatic BP measurement devices. Currently, most of these devices measure and record amplitude of cuff pressure oscillation, and then calculate diastolic and systolic pressure using characteristic ratios and designed algorithms. A finite element (FE) model is developed to study the biomechanical basis of this technique. The model identifies that errors were caused by mechanical factors of the soft tissue and the shape of the arm. By personalizing the parameters for each patient, the accuracy of the measurement will be improved for all age groups

Traumatic surfing injuries in New Zealand: a descriptive epidemiology study

BACKGROUND: New Zealand (NZ) has nearly 14,000 km of coastline and a surfing population of approximately 315,000 surfers. Given its popularity, surfing has a high frequency of injury claims, however, there remains a lack of data on traumatic surfing-related injuries from large population studies. The primary purpose of this study was to examine traumatic surfing injuries in NZ specific to injury incidence, duration, location, type, mechanism of injury and associated risk factors. METHODS: A sample of self-identified surfers currently living in NZ participated in an online retrospective cross-sectional survey between December 2015 and July 2016. Demographic and surfing injury data were collected and analysed. RESULTS: The survey yielded 1,473 respondents (18.3% female); a total of 502 surfers reported 702 major traumatic injuries with an overall incidence proportion of 0.34 (95% CI [0.32–0.37]). When comparing the number of injured surfers who sustained an injury at various body locations, a significantly higher proportion of competitive surfers, compared to recreational surfers, had an injury at the neck (6.8% vs 4%, χ(2) (1,1473) = 5.84, P = 0.019); shoulder (7.4% vs 4.3%, χ(2) (1,1473) = 6.34, P = 0.017), upper back (1% vs 2.4%, χ(2) (1,1473) = 4.77, P = 0.043), lower back (7% vs 3.1%, χ(2) (1,1473) = 11.98, P = 0.001) and knee (7% vs 3.4%, χ(2) (1,1473) = 9.67, P = 0.003). A significantly higher proportion of surfers who performed aerial manoeuvres compared to those who did not reported a higher proportion of knee injuries (9.7% vs 3.9%, χ(2) (1,1473) = 13.00, P = 0.001). With respect to injury duration, the shoulder represented the largest proportion of chronic injuries (>3 months) (44.4%), and the head and face represented the largest proportion of acute injuries (≤3 months) (88%). Muscle and tendon injuries were reported most frequently (25.6%) and direct contact injuries accounted for 58.1% of all injury mechanisms. Key risk factors for traumatic injury included: competitive compared to recreational status (41.0% vs 30.1%, Relative Risk (RR) = 1.36, P < 0.001), ability to perform aerial manoeuvres (48.1% vs 31.8%, RR = 1.51, P < 0.001) and intermediate or above skill level surfers compared to beginner surfers (35.8% vs 22.7%, RR = 1.58, P < 0.001). CONCLUSION: One third of recreational surfers sustained a major traumatic injury in the previous 12 months. For competitive or aerialist surfers the risk was greater, with this proportion approximately half. Overall, the head/face was the most common location of traumatic injury, with competitive surfers being more likely to sustain a neck, shoulder, lower back, and knee injury compared to recreational surfers. The shoulder was associated with the highest proportion of injuries of chronic duration. Future research should investigate injury mechanisms and causation using prospective injury monitoring to better underpin targeted injury prevention programs

Photoelectrochemical imaging system for the mapping of cell surface charges

The surface charge of cells affects cell signaling, cell metabolic processes, adherence to surfaces, and cell proliferation. Our understanding of the role of membrane charges is limited due to the inability to observe changes without interfering, chemically or physically, with the cell or its membrane. Here, we report that a photoelectrochemical imaging system (PEIS) based on label-free ac-photocurrent measurements at indium tin oxide (ITO) coated glass substrates can be used to map the basal surface charge of single live cells under physiological conditions. Cells were cultured on the ITO substrate. Photocurrent images were generated by scanning a focused, modulated laser beam across the back of the ITO coated glass substrate under an applied bias voltage. The photocurrent was shown to be sensitive to the negative surface charge of the substrate facing, basal side of a single living cell—an area not accessible to other electrochemical or electrophysiological imaging techniques. The PEIS was used to monitor the lysis of mesenchymal stem cells

Physiological Profile of Male Competitive and Recreational Surfers

Surfing consists of both high- and low-intensity paddling of varying durations, using both the aerobic and anaerobic systems. Surf-specific physiological studies lack adequate group sample sizes, and V[Combining Dot Above]O2peak values are yet to determine the differences between competitive and recreational surfers. The purpose of this study was therefore to provide a comprehensive physiological profile of both recreational and competitive surfers. This multisite study involved 62 male surfers, recreational (n = 47) and competitive (n = 15). Anthropometric measurements were conducted followed by dual-energy x-ray absorptiometry, anaerobic testing and finally aerobic testing. V[Combining Dot Above]O2peak was significantly greater in competitive surfers than in recreational surfers (M = 40.71 ± 3.28 vs. 31.25 ± 6.31 ml·kg·min, p \u3c 0.001). This was also paralleled for anaerobic power (M = 303.93 vs. 264.58 W) for competitive surfers. Arm span and lean total muscle mass was significantly (p ≤ 0.01) correlated with key performance variables (V[Combining Dot Above]O2peak and anaerobic power). No significant (p ≥ 0.05) correlations were revealed between season rank and each of the variables of interest (V[Combining Dot Above]O2peak and anaerobic power). Key performance variables (V[Combining Dot Above]O2peak and anaerobic power) are significantly higher in competitive surfers, indicating that this is both an adaptation and requirement in this cohort. This battery of physiological tests could be used as a screening tool to identify an athlete\u27s weaknesses or strengths. Coaches and clinicians could then select appropriate training regimes to address weaknesses

Selective laser sintering of hydroxyapatite reinforced polyethylene composites for bioactive implants and tissue scaffold development

Selective laser sintering (SLS) has been investigated for the production of bioactive implants and tissue scaffolds using composites of high-density polyethylene (HDPE) reinforced with hydroxyapatite (HA) with the aim of achieving the rapid manufacturing of customized implants. Single-layer and multilayer block specimens made of HA-HDPE composites with 30 and 40 vol % HA were sintered successfully using a CO2 laser sintering system. Laser power and scanning speed had a significant effect on the sintering behaviour. The degree of particle fusion and porosity were influenced by the laser processing parameters, hence control can be attained by varying these parameters. Moreover, the SLS processing allowed exposure of HA particles on the surface of the composites and thereby should provide bioactive products. Pores existed in the SLS-fabricated composite parts and at certain processing parameters a significant fraction of the pores were within the optimal sizes for tissue regeneration. The results indicate that the SLS technique has the potential not only to fabricate HA-HDPE composite products but also to produce appropriate features for their application as bioactive implants and tissue scaffolds

Modelo de avaliação da disfunção arterial na região cervical, pré-­‐intervenção com Terapia Manual Ortopédica (TMO)

Tradução do documento “International Framework for Examination of the Cervical Region for potential of Cervical Arterial Dysfunction prior to Orthopaedic Manual Therapy Intervention" por Diogo Pires, Eduarto Brazete Cruz, Isabel Bastos de Almeida, João Filipe Vasconcelos Abreu, Lúcia Domingues e Susana Duarteinfo:eu-repo/semantics/publishedVersio

Seminal plasma as a source of prostate cancer peptide biomarker candidates for detection of indolent and advanced disease

Background:Extensive prostate specific antigen screening for prostate cancer generates a high number of unnecessary biopsies and over-treatment due to insufficient differentiation between indolent and aggressive tumours. We hypothesized that seminal plasma is a robust source of novel prostate cancer (PCa) biomarkers with the potential to improve primary diagnosis of and to distinguish advanced from indolent disease. &lt;br&gt;Methodology/Principal Findings: In an open-label case/control study 125 patients (70 PCa, 21 benign prostate hyperplasia, 25 chronic prostatitis, 9 healthy controls) were enrolled in 3 centres. Biomarker panels a) for PCa diagnosis (comparison of PCa patients versus benign controls) and b) for advanced disease (comparison of patients with post surgery Gleason score &#60;7 versus Gleason score &#62;&gt;7) were sought. Independent cohorts were used for proteomic biomarker discovery and testing the performance of the identified biomarker profiles. Seminal plasma was profiled using capillary electrophoresis mass spectrometry. Pre-analytical stability and analytical precision of the proteome analysis were determined. Support vector machine learning was used for classification. Stepwise application of two biomarker signatures with 21 and 5 biomarkers provided 83% sensitivity and 67% specificity for PCa detection in a test set of samples. A panel of 11 biomarkers for advanced disease discriminated between patients with Gleason score 7 and organ-confined (&#60;pT3a) or advanced (&#8805;pT3a) disease with 80% sensitivity and 82% specificity in a preliminary validation setting. Seminal profiles showed excellent pre-analytical stability. Eight biomarkers were identified as fragments of N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase​,prostatic acid phosphatase, stabilin-2, GTPase IMAP family member 6, semenogelin-1 and -2. Restricted sample size was the major limitation of the study.&lt;/br&gt; &lt;br&gt;Conclusions/Significance: Seminal plasma represents a robust source of potential peptide makers for primary PCa diagnosis. Our findings warrant further prospective validation to confirm the diagnostic potential of identified seminal biomarker candidates.&lt;/br&gt