71 research outputs found

    Thermal and cardiovascular strain imposed by motorcycle protective clothing under Australian summer conditions

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    Motorcycle protective clothing can be uncomfortably hot during summer, and this experiment was designed to evaluate the physiological significance of that burden. Twelve males participated in four, 90-min trials (cycling 30 W) across three environments (25, 30, 35 °C [all 40% relative humidity]). Clothing was modified between full and minimal injury protection. Both ensembles were tested at 25 °C, with only the more protective ensemble investigated at 30 and 35 °C. At 35 °C, auditory canal temperature rose at 0.02 °C min(-1) (SD 0.005), deviating from all other trials (p \u3c 0.05). The thresholds for moderate (\u3e38.5 °C) and profound hyperthermia (\u3e40.0 °C) were predicted to occur within 105 min (SD 20.6) and 180 min (SD 33.0), respectively. Profound hyperthermia might eventuate in ~10 h at 30 °C, but should not occur at 25 °C. These outcomes demonstrate a need to enhance the heat dissipation capabilities of motorcycle clothing designed for summer use in hot climates, but without compromising impact protection. Practitioner\u27s Summary: Motorcycle protective clothing can be uncomfortably hot during summer. This experiment was designed to evaluate the physiological significance of this burden across climatic states. In the heat, moderate (\u3e38.5 °C) and profound hyperthermia (\u3e40.0 °C) were predicted to occur within 105 and 180 min, respectively

    Motorcycle protective clothing: physiological and perceptual barriers to its summer use

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    Despite strong evidence of protective benefits, thermal discomfort is a key disincentive to motorcyclists wearing protective clothing in hot conditions. This paper presents some findings from our studies concerning the thermal management properties of motorcycle protective clothing and their physiological impact in hot conditions. The thermal and vapour permeability and abrasion resistance properties of motorcycle protective clothing were investigated in laboratory tests. The physiological and cognitive impact on humans was investigated using objective and subjective measures under controlled climate conditions and in a real-world riding trial. The aims were to determine: (i) if associations existed between thermal management and the abrasion-resistance properties of a range of commonly available, all-season motorcycle protective suits, (ii) the extent of the thermal load imposed by motorcycle clothing worn in average Australian summer conditions, and (iii) the impact of that thermal burden on psychophysical function. The results demonstrated significant physiological strain for motorcyclists wearing protective clothing in hot conditions. Wide variations in the thermal characteristics and abrasion resistance properties of the suits tested were identified. Ongoing work is investigating the impact that elevated thermal discomfort and physiological thermal strain can have on riding performance and the potential for clothing features, such as ventilation ports to reduce thermal discomfort. These results will determine thresholds for the thermal qualities of motorcycle clothing required for an acceptable compromise between user comfort and injury protection. The outcome will inform industry and consumer information programs about the performance required of motorcycle protective clothing suitable for use in hot conditions

    Thermal and cardiovascular strain imposed by motorcycle protective clothing under Australian summer conditions

    Get PDF
    Motorcycle protective clothing can be uncomfortably hot during summer, and this experiment was designed to evaluate the physiological significance of that burden. Twelve males participated in four, 90-min trials (cycling 30 W) across three environments (25, 30, 35 °C [all 40% relative humidity]). Clothing was modified between full and minimal injury protection. Both ensembles were tested at 25 °C, with only the more protective ensemble investigated at 30 and 35 °C. At 35 °C, auditory canal temperature rose at 0.02 °C min(-1) (SD 0.005), deviating from all other trials (p \u3c 0.05). The thresholds for moderate (\u3e38.5 °C) and profound hyperthermia (\u3e40.0 °C) were predicted to occur within 105 min (SD 20.6) and 180 min (SD 33.0), respectively. Profound hyperthermia might eventuate in ~10 h at 30 °C, but should not occur at 25 °C. These outcomes demonstrate a need to enhance the heat dissipation capabilities of motorcycle clothing designed for summer use in hot climates, but without compromising impact protection. Practitioner\u27s Summary: Motorcycle protective clothing can be uncomfortably hot during summer. This experiment was designed to evaluate the physiological significance of this burden across climatic states. In the heat, moderate (\u3e38.5 °C) and profound hyperthermia (\u3e40.0 °C) were predicted to occur within 105 and 180 min, respectively

    Categorisation of foot complaints in systemic lupus erythematosus (SLE) from a New Zealand cohort

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    Background: Foot complaints have been shown to be common in systemic lupus erythematosus (SLE) and heterogeneous in nature. We aimed to categorize self-reported foot complaints in people with SLE and foot symptoms. Methods A self-administered validated questionnaire was posted to 406 people with SLE attending adult rheumatology clinics across three health boards in Auckland, New Zealand. In addition to foot pain, vascular complaints, dermatological lesions and neurological symptoms were included in the analysis. Pairwise correlations among the variables were undertaken followed by factor analysis to identify and categorise associations between reported foot complaints. Results From the questionnaires returned, 93 full datasets were analysed. Participants’ were predominantly female (n =87, 93.7%), with mean (SD) age of 50.4 (14.3) years and a mean (SD) disease duration of 13.1 (11) years. Three categories of foot complaint were determined: ‘foot pain’, ‘skin disorders’ and ‘vascular insufficiency’. These three groups provided the best fit (0.91) to describe the wide range of foot complaints reported by those with SLE. Factor analysis for foot pain demonstrated a high positive loading for the inter-correlation of foot pain in past month (0.83), foot pain today (0.71), intermittent claudication (0.71), numbness (0.62), loss of balance (0.81), swelling (0.59), foot joint pain (0.77), arch pain (0.68) and tendon pain (0.77). Skin disorders demonstrated a very high positive loading for 3 factors skin rash (0.82), blistering skin rash (0.95) and foot ulceration (0.88). In vascular insufficiency a high positive loading for cold feet (0.83), chilblains (0.76) and Raynaud’s phenomenon (0.70) Conclusions This work suggests people with SLE report three independent categories of foot complaints; foot pain, skin disorders or vascular insufficiency

    K-ras mutations in sinonasal cancers in relation to wood dust exposure

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    <p>Abstract</p> <p>Background</p> <p>Cancer in the sinonasal tract is rare, but persons who have been occupationally exposed to wood dust have a substantially increased risk. It has been estimated that approximately 3.6 million workers are exposed to inhalable wood dust in EU. In previous small studies of this cancer, <it>ras </it>mutations were suggested to be related to wood dust exposure, but these studies were too limited to detect statistically significant associations.</p> <p>Methods</p> <p>We examined 174 cases of sinonasal cancer diagnosed in Denmark in the period from 1991 to 2001. To ensure uniformity, all histological diagnoses were carefully reviewed pathologically before inclusion. Paraffin embedded tumour samples from 58 adenocarcinomas, 109 squamous cell carcinomas and 7 other carcinomas were analysed for K-<it>ras </it>codon 12, 13 and 61 point mutations by restriction fragment length polymorphisms and direct sequencing. Information on occupational exposure to wood dust and to potential confounders was obtained from telephone interviews and from registry data.</p> <p>Results</p> <p>Among the patients in this study, exposure to wood dust was associated with a 21-fold increased risk of having an adenocarcinoma than a squamous cell carcinoma compared to unexposed [OR = 21.0, CI = 8.0–55.0]. K-<it>ras </it>was mutated in 13% of the adenocarcinomas (seven patients) and in 1% of squamous cell carcinomas (one patient). Of these eight mutations, five mutations were located in the codon 12. The exact sequence change of remaining three could not be identified unambiguously. Among the five identified mutations, the G→A transition was the most common, and it was present in tumour tissue from two wood dust exposed adenocarcinoma patients and one patient with unknown exposure. Previously published studies of sinonasal cancer also identify the GGT → GAT transition as the most common and often related to wood dust exposure.</p> <p>Conclusion</p> <p>Patients exposed to wood dust seemed more likely to develop adenocarcinoma compared to squamous cell carcinomas. K-<it>ras </it>mutations were detected in 13% of adenocarcinomas. In this study and previously published studies of sinonasal cancer the found K-<it>ras </it>mutations, were almost exclusively G → A transitions. In conclusion, our study, based on a large representative collection of human SNC tumours, indicates that K-<it>ras </it>mutations are relatively infrequent, and most commonly occur in adenocarcinomas. Wood dust exposure alone was not found to be explanatory for the G→A mutations, but combination of exposure to tobacco, wood dust, and possibly other occupational agents may be a more likely explanation. Overall, the study suggests a limited role for K-<it>ras </it>mutations in development of sinonasal cancer.</p

    Electrical conductivity measurement: a new technique to detect iatrogenic initial pedicle perforation

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    Abstract Pedicle screw fixation has achieved significant popularity amongst spinal surgeons for both single and multi-level spinal fusion. Misplacement and pedicle cortical violation occurs in over 20% of screw placement and can result in potential complications such as dysthesia, paraparesis or paraplegia. There have been many advances in techniques available for navigating through the pedicle; however, these techniques are not without drawbacks. A new electrical conductivity-measuring device, previously evaluated on the porcine model to detect the pedicle violation, was evaluated amongst nine European Hospitals to be used in conjunction with the methods currently used in that centre. This new device is based on two original principles; the device is integrated in the drilling or screwing tool. The technology allows real-time detection of perforation through two independent parameters, impedance variation and evoked muscle contractions. Data was collected twofold. Initially, the surgeon was given the device and a comparison was made between the devices ability to detect a breech and the surgeon&apos;s ability to detect one using his traditional methods of pedicle preparation. In the second module of the study, the surgeon was limited to using the electrical conductivity detection device as their sole guide to detect pedicle breaches. A comparison was made between the detection ability of the device and the other detection possibilities. Post-operative fine cut CT scanning was used to detect the pedicle breaches. Overall, the 11 trial surgeons performed a total of 521 pedicle drillings on 97 patients. Initially there were 147 drillings with 23 breaches detected. The detection rate of these breaches were 22/23 for the device compared to 10/23 by the surgeon. Over both parts of the study 64 breaches (12.3%) were confirmed on post-operative CT imaging. The electrical conductivity detection device detected 63 of the 64 breaches (98.4%). There was one false negative and four false positives. This gives the device an overall sensitivity of 98% and specificity of 99% for detecting a pedicle breach. The negative predictive value was 99.8%, with a positive predictive value of 94%. No adverse event was noted with the use of the electrical conductivity device. Electrical conductivity monitoring may provide

    Identification of Novel Proteins in Neospora caninum Using an Organelle Purification and Monoclonal Antibody Approach

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    Neospora caninum is an important veterinary pathogen that causes abortion in cattle and neuromuscular disease in dogs. Neospora has also generated substantial interest because it is an extremely close relative of the human pathogen Toxoplasma gondii, yet does not appear to infect humans. While for Toxoplasma there are a wide array of molecular tools and reagents available for experimental investigation, relatively few reagents exist for Neospora. To investigate the unique biological features of this parasite and exploit the recent sequencing of its genome, we have used an organelle isolation and monoclonal antibody approach to identify novel organellar proteins and develop a wide array of probes for subcellular localization. We raised a panel of forty-six monoclonal antibodies that detect proteins from the rhoptries, micronemes, dense granules, inner membrane complex, apicoplast, mitochondrion and parasite surface. A subset of the proteins was identified by immunoprecipitation and mass spectrometry and reveal that we have identified and localized many of the key proteins involved in invasion and host interaction in Neospora. In addition, we identified novel secretory proteins not previously studied in any apicomplexan parasite. Thus, this organellar monoclonal antibody approach not only greatly enhances the tools available for Neospora cell biology, but also identifies novel components of the unique biological characteristics of this important veterinary pathogen

    Medial longitudinal arch development of school children : The College of Podiatry Annual Conference 2015: meeting abstracts

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    Background Foot structure is often classified into flat foot, neutral and high arch type based on the variability of the Medial Longitudinal Arch (MLA). To date, the literature provided contrasting evidence on the age when MLA development stabilises in children. The influence of footwear on MLA development is also unknown. Aim This study aims to (i) clarify whether the MLA is still changing in children from age 7 to 9 years old and (ii) explore the relationship between footwear usage and MLA development, using a longitudinal approach. Methods We evaluated the MLA of 111 healthy school children [age = 6.9 (0.3) years] using three parameters [arch index (AI), midfoot peak pressure (PP) and maximum force (MF: % of body weight)] extracted from dynamic foot loading measurements at baseline, 10-month and 22-month follow-up. Information on the type of footwear worn was collected using survey question. Linear mixed modelling was used to test for differences in the MLA over time. Results Insignificant changes in all MLA parameters were observed over time [AI: P = .15; PP: P = .84; MF: P = .91]. When gender was considered, the AI of boys decreased with age [P = .02]. Boys also displayed a flatter MLA than girls at age 6.9 years [AI: mean difference = 0.02 (0.01, 0.04); P = .02]. At baseline, subjects who wore close-toe shoes displayed the lowest MLA overall [AI/PP/MF: P < .05]. Subjects who used slippers when commencing footwear use experienced higher PP than those who wore sandals [mean difference = 31.60 (1.44, 61.75) kPa; post-hoc P = .04]. Discussion and conclusion Our findings suggested that the MLA of children remained stable from 7 to 9 years old, while gender and the type of footwear worn during childhood may influence MLA development. Clinicians may choose to commence therapy when a child presents with painful flexible flat foot at age 7 years, and may discourage younger children from wearing slippers when they commence using footwear

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
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