56 research outputs found

    3D random fiber composites as a repair material for damaged honeycomb cores

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    Povećana upotreba kompozitnih materijala donela potrebu za razvojem pouzdanih i efikasnih tehnika popravki. Kao i sve druge noseće metalne strukture i kompozitne strukture sklone su oštećenjima. Razvijene tehnike popravki metalnih konstrukcije nisu direktno primenljive na kompozite i problem popravki kompozitnih struktura mora biti detaljno proučen. U ovom radu analizirana je primena kompozitnih materijala sa slučajnim rasporedom vlakana, kao materijalom za popravku oštećenih saćastih jezgara visoke gustine sendvič konstrukcija. Pomoću Panove teorije izveden je izraz potrebnog zapreminskog udela vlakana materijala popravke i određeno je kompletno naponsko deformaciono stanje popravljene kompozitne stukture metodom konačnih elemenata. Zaključeno je da kompozitni materijali sa slučajnim rasporedom vlakana predstavljaju veoma dobre kandidate za popravku oštećenih kompozitnih struktura sa saćastim jezgrima.The increased use of composites has rendered the need for development of reliable and efficient repair techniques. Like all other metallic structures composite structures are prone to variety of damage. Repair techniques developed for metallic structures are not directly applicable to composites and problem of composite repair has to be investigated in great detail. In the present paper application of 3D random fiber polymer composites, as a repair material for damaged high density honeycomb cores in sandwich structures is investigated. Based on Pan 's theory the expression for matching fiber volume fraction of the repair material is derived and complete stress-strain field, of the repaired sandwich structure is determined using finite element approach. It is concluded that the 3D random fiber composites represent very good candidates as repair materials for damaged honeycomb structured composites

    L’observation de l’écologie de quelques algues

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    Les auteurs décrivent deux cas de l’épiphytisme sur le Fucus vir- soides de l’ Adriatique. Les épiphytes sont Ulva lactuca et Cladophora spec. Us germent des conceptaculums (Ulva) ou de la surface (Cladophora). Concernant les conceptaculums on doit supposer que les zoospores, planozigotes ou les gametes y soient arrivés. D’ailleurs on ne pouvait remarquer aucun changement soit sur les hôtes soit sur les épiphytes (v. les fig. !). Hors de cela il est cité une trouvaille de l’algue tropique Pithophora du Jardin \u27botanique de Zagreb. Cette algue a été y trouvée aussi plus tôt (Milicic, 1949) mais nos exemplaires ont les autres données morphologiques et dimensionelles

    Survival of outborns with congenital diaphragmatic hernia: the role of protective ventilation, early presentation and transport distance: a retrospective cohort study

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    BACKGROUND: Congenital diaphragmatic hernia (CDH) is a congenital malformation associated with life-threatening pulmonary dysfunction and high neonatal mortality. Outcomes are improved with protective ventilation, less severe pulmonary pathology, and the proximity of the treating center to the site of delivery. The major CDH treatment center in Croatia lacks a maternity ward, thus all CDH patients are transferred from local Zagreb hospitals or remote areas (outborns). In 2000 this center adopted protective ventilation for CDH management. In the present study we assess the roles of protective ventilation, transport distance, and severity of pulmonary pathology on survival of neonates with CDH. ----- METHODS: The study was divided into Epoch I, (1990-1999, traditional ventilation to achieve normocapnia), and Epoch II, (2000-2014, protective ventilation with permissive hypercapnia). Patients were categorized by transfer distance (local hospital or remote locations) and by acuity of respiratory distress after delivery (early presentation-occurring at birth, or late presentation, ≥ 6 h after delivery). Survival between epochs, types of transfers, and acuity of presentation were assessed. An additional analysis was assessed for the potential association between survival and end-capillary blood CO2 (PcCO2), an indirect measure of pulmonary pathology. ----- RESULTS: There were 83 neonates, 26 in Epoch I, and 57 in Epoch II. In Epoch I 11 patients (42%) survived, and in Epoch II 38 (67%) (P = 0.039). Survival with early presentation (N = 63) was 48 % and with late presentation 95% (P <0.001). Among early presentation, survival was higher in Epoch II vs. Epoch I (57% vs. 26%, P = 0.031). From multiple logistic regression analysis restricted to neonates with early presentation and adjusting for severity of disease, survival was improved in Epoch II (OR 4.8, 95%CI 1.3-18.0, P = 0.019). Survival was unrelated to distance of transfer but improved with lower partial pressure of PcCO2 on admission (OR 1.16, 95%CI 1.01-1.33 per 5 mmHg decrease, P = 0.031). ----- CONCLUSIONS: The introduction of protective ventilation was associated with improved survival in neonates with early presentation. Survival did not differ between local and remote transfers, but primarily depended on severity of pulmonary pathology as inferred from admission capillary PcCO2

    Body Size Changes in Elite Junior Rowers: 1997 to 2007

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    The aim of this study was to determine whether elite international junior rowers in 2007 were heavier and taller than those evaluated in 1997, and to compare this change among finalists and non-finalists, and sweep rowers and scullers. Body weight and height data obtained by a questionnaire from a total of 398 rowers (42% female, 58% male) at the Junior World Rowing Championships in Beijing, People’s Republic of China, in 2007 (65.9% of all competitors), were compared with data from 603 rowers measured at the Junior World Rowing Championships in Hazewinkel, Belgium in 1997 (36.5% female, 63.5% male, representing 90% and 89% of all competitors, respectively, by gender). Male and female rowers in 2007 were significantly taller compared to those in 1997 (1.0 cm, p=0.009 and 2.1 cm, p<0.001, respectively; one-sample t-test). No statistically significant difference was found for body mass. The finalists and sweep rowers were taller and heavier compared to nonfinalists and scullers at both Championships respectively. The heights of elite level junior rowers increased significantly over the decade. The finalists at World Junior Rowing Championships were again taller and heavier compared to the nonfinalists

    Has the COVID-19 pandemic influenced suicide rates differentially according to socioeconomic indices and ethnicity? More evidence is needed globally

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    Abstract The COVID-19 pandemic has harmed many people's mental health globally. Whilst the evidence generated thus far from high-income countries regarding the pandemic's impact on suicide rates is generally reassuring, we know little about its influence on this outcome in lower- and middle-income countries or among marginalised and disadvantaged people. There are some signals for concern regarding the pandemic's potentially unequal impact on suicide rates, with some of the affected demographic subgroups and regions being at elevated risk before the pandemic began. However, the evidence-base for this topic is currently sparse, and studies conducted to date have generally not taken account of pre-pandemic temporal trends. The collection of accurate, complete and comparable data on suicide rate trends in ethnic minority and low-income groups should be prioritised. The vulnerability of low-income groups will likely be exacerbated further by the current energy supply and cost-of-living crises in many countries. It is therefore crucial that reassuring messaging highlighting the stability of suicide rates during the pandemic does not lead to complacency among policymakers.</jats:p

    Antibiotic consumption and antimicrobial resistance in Poland; findings and implications

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    Background: The problem of inappropriate use of antibiotics and the resulting growth in antimicrobial resistance (AMR) has implications for Poland and the world. The objective of this paper was to compare and contrast antibiotic resistance and antibiotic utilisation in Poland in recent years versus other European countries, including agreed quality indicators, alongside current AMR patterns and ongoing policies and initiatives in Poland to influence and improve antibiotic prescribing. Methods: A quantitative ten-year analysis (2007-2016) of the use of antibiotics based on European Centre for Disease Prevention and Control (ECDC) data combined with a literature review on AMR rates and antimicrobial stewardship initiatives. Results: The system of monitoring AMR and appropriate strategies to address AMR rates remain underdeveloped in Poland. The role of microbiological diagnostics and efforts to prevent infections is currently underestimated by physicians. Overall, Poland had one of the highest rates of total consumption of antibiotics in the analysed European countries. Total consumption of antibacterials for systemic use and relative consumption of beta-lactamase sensitive penicillins were characterized by small but statistically significant average annual increases between 2007 and 2016 (from 22.2DIDs to 23.9 DIDs and from 0.8% to 1.3%, respectively). Conclusions: The integrated activities around appropriate antibiotic prescribing in the pre- and post-graduate training of physicians and dentists seem to be particularly important, as well as changes in policies on prescribing antibiotics within ambulatory care. AMR and appropriate prescribing of antibiotics should be the focus of health policy actions in Poland

    The general fault in our fault lines

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    Pervading global narratives suggest that political polarization is increasing, yet the accuracy of such group meta-perceptions has been drawn into question. A recent US study suggests that these beliefs are inaccurate and drive polarized beliefs about out-groups. However, it also found that informing people of inaccuracies reduces those negative beliefs. In this work, we explore whether these results generalize to other countries. To achieve this, we replicate two of the original experiments with 10,207 participants across 26 countries. We focus on local group divisions, which we refer to as fault lines. We find broad generalizability for both inaccurate meta-perceptions and reduced negative motive attribution through a simple disclosure intervention. We conclude that inaccurate and negative group meta-perceptions are exhibited in myriad contexts and that informing individuals of their misperceptions can yield positive benefits for intergroup relations. Such generalizability highlights a robust phenomenon with implications for political discourse worldwide

    Ongoing strategies to improve the management of upper respiratory tract infections and reduce inappropriate antibiotic use particularly among lower and middle-income countries: findings and implications for the future

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    Introduction: Antibiotics are indispensable to maintaining human health; however, their overuse has resulted in resistant organisms, increasing morbidity, mortality and costs. Increasing antimicrobial resistance (AMR) is a major public health threat, resulting in multiple campaigns across countries to improve appropriate antimicrobial use. This includes addressing the overuse of antimicrobials for self-limiting infections, such as upper respiratory tract infections (URTIs), particularly in lower- and middle-income countries (LMICs) where there is the greatest inappropriate use and where antibiotic utilization has increased the most in recent years. Consequently, there is a need to document current practices and successful initiatives in LMICs to improve future antimicrobial use. Methodology: Documentation of current epidemiology and management of URTIs, particularly in LMICs, as well as campaigns to improve future antimicrobial use and their influence where known. Results: Much concern remains regarding the prescribing and dispensing of antibiotics for URTIs among LMICs. This includes considerable self-purchasing, up to 100% of pharmacies in some LMICs. However, multiple activities are now ongoing to improve future use. These incorporate educational initiatives among all key stakeholder groups, as well as legislation and other activities to reduce self-purchasing as part of National Action Plans (NAPs). Further activities are still needed however. These include increased physician and pharmacist education, starting in medical and pharmacy schools; greater monitoring of prescribing and dispensing practices, including the development of pertinent quality indicators; and targeted patient information and health education campaigns. It is recognized that such activities are more challenging in LMICs given more limited resources and a lack of healthcare professionals. Conclusion: Initiatives will grow across LMICs to reduce inappropriate prescribing and dispensing of antimicrobials for URTIs as part of NAPs and other activities, and these will be monitored

    COVID-19 trajectories among 57 million adults in England: a cohort study using electronic health records

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    BACKGROUND: Updatable estimates of COVID-19 onset, progression, and trajectories underpin pandemic mitigation efforts. To identify and characterise disease trajectories, we aimed to define and validate ten COVID-19 phenotypes from nationwide linked electronic health records (EHR) using an extensible framework. METHODS: In this cohort study, we used eight linked National Health Service (NHS) datasets for people in England alive on Jan 23, 2020. Data on COVID-19 testing, vaccination, primary and secondary care records, and death registrations were collected until Nov 30, 2021. We defined ten COVID-19 phenotypes reflecting clinically relevant stages of disease severity and encompassing five categories: positive SARS-CoV-2 test, primary care diagnosis, hospital admission, ventilation modality (four phenotypes), and death (three phenotypes). We constructed patient trajectories illustrating transition frequency and duration between phenotypes. Analyses were stratified by pandemic waves and vaccination status. FINDINGS: Among 57 032 174 individuals included in the cohort, 13 990 423 COVID-19 events were identified in 7 244 925 individuals, equating to an infection rate of 12·7% during the study period. Of 7 244 925 individuals, 460 737 (6·4%) were admitted to hospital and 158 020 (2·2%) died. Of 460 737 individuals who were admitted to hospital, 48 847 (10·6%) were admitted to the intensive care unit (ICU), 69 090 (15·0%) received non-invasive ventilation, and 25 928 (5·6%) received invasive ventilation. Among 384 135 patients who were admitted to hospital but did not require ventilation, mortality was higher in wave 1 (23 485 [30·4%] of 77 202 patients) than wave 2 (44 220 [23·1%] of 191 528 patients), but remained unchanged for patients admitted to the ICU. Mortality was highest among patients who received ventilatory support outside of the ICU in wave 1 (2569 [50·7%] of 5063 patients). 15 486 (9·8%) of 158 020 COVID-19-related deaths occurred within 28 days of the first COVID-19 event without a COVID-19 diagnoses on the death certificate. 10 884 (6·9%) of 158 020 deaths were identified exclusively from mortality data with no previous COVID-19 phenotype recorded. We observed longer patient trajectories in wave 2 than wave 1. INTERPRETATION: Our analyses illustrate the wide spectrum of disease trajectories as shown by differences in incidence, survival, and clinical pathways. We have provided a modular analytical framework that can be used to monitor the impact of the pandemic and generate evidence of clinical and policy relevance using multiple EHR sources. FUNDING: British Heart Foundation Data Science Centre, led by Health Data Research UK
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