56 research outputs found

    On the Significance and Predicted Functional Effects of the Crown-to-Implant Ratio: a Finite Element Study of Long-Term Implant Stability Using High-Resolution, Nonlinear Numerical Analysis

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    poster abstractBackground. As the use of short dental implants becomes increasingly popular, the effects of the crown-to-implant (C/I) ratio on stress and strain distributions remain controversial. Previous studies in literature disagree on results of interest and level of necessary technical detail. Purpose. The present study sought to evaluate the strain distribution and assess its functional implications in a single implant-supported crown with various C/I ratios placed in the maxillary molar region. Materials and Methods. A high-fidelity, nonlinear finite-element model was developed to simulate multiple clinical scenarios by laterally loading a set of single implants with various implant lengths and crown heights. Strain distribution and maximum equivalent strain were analyzed to evaluate the effects and significance of the crown height, implant length and C/I ratio. The consistency of predicted functional responses to resulting strain at the implant interface were analyzed by interface surface area. Results. Results were evaluated according to the mechanostat hypothesis to predict functional response to strain. Overloading and effects of strain concentrations were more prevalent with increasing C/I ratios. Overloading was predicted for all configurations to varying degrees, and increased with decreasing implant lengths. Fracture in trabecular bone was predicted for at least one C/I ratio and all implant lengths of 10 mm or less. Conclusions. Higher C/I ratios and lower implant lengths increase the biomechanical risks of overloading and fracture. Increasing C/I ratios augment the functional effects of other implant design factors, particularly implant interface features. Greater C/I ratios may be achieved with implant designs that induce less significant strain concentrations

    A cytoplasmic RNA virus generates functional viral small RNAs and regulates viral IRES activity in mammalian cells

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    The roles of virus-derived small RNAs (vsRNAs) have been studied in plants and insects. However, the generation and function of small RNAs from cytoplasmic RNA viruses in mammalian cells remain unexplored. This study describes four vsRNAs that were detected in enterovirus 71-infected cells using next-generation sequencing and northern blots. Viral infection produced substantial levels (\u3e105 copy numbers per cell) of vsRNA1, one of the four vsRNAs. We also demonstrated that Dicer is involved in vsRNA1 generation in infected cells. vsRNA1 overexpression inhibited viral translation and internal ribosomal entry site (IRES) activity in infected cells. Conversely, blocking vsRNA1 enhanced viral yield and viral protein synthesis. We also present evidence that vsRNA1 targets stem-loop II of the viral 5′ untranslated region and inhibits the activity of the IRES through this sequence-specific targeting. Our study demonstrates the ability of a cytoplasmic RNA virus to generate functional vsRNA in mammalian cells. In addition, we also demonstrate a potential novel mechanism for a positive-stranded RNA virus to regulate viral translation: generating a vsRNA that targets the IRES

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    Epidemiology of community-acquired bacteremia among infants in a medical center in Taiwan, 2002-2011

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    Objective: To investigate the etiologies and antibiotic susceptibility of community-acquired bacteremia in infants in a medical center in northern Taiwan. ;Methods: We conducted a retrospective analysis of all blood cultures from infants in the National Taiwan University Hospital from 2002 to 2011 to find community-acquired bacteremia. Common pathogens, antibiotic resistance, and outcome were analyzed. ;Results: During the study period, 25,628 blood cultures were collected, and 3.4% of the cultures were positive, of which 15.9% were categorized as community-acquired bacteremia. In the age group of 0-6-days, the leading causative organisms were group B streptococcus (41.7%) and Escherichia coli (30.6%). In the 7-90-days and 4-6-months groups, the most common pathogens were E. coli (44.1%, 45.5%, respectively) and group B streptococcus (32.4%, 13.6%, respectively). For infants aged 7-12 months, the most common pathogens were Salmonella species (51.1%) and E. coli (12.8%). The overall mortality rate of community-acquired bacteremia was 6%. Urinary tract infection was the concomitant diagnosis among 52.4% of infants with E. coli bacteremia. Meningitis was found in 33.3% of infants with group B streptococcus bacteremia. Listeria monocytogenes bacteremia was identified in three infants, one of whom had meningitis. Penicillin resistance was found in 4% of group B streptococcus and ampicillin resistance in 71% of E. coli. ;Conclusion: Our study provides updated etiological data on community-acquired bacteremia in infants in northern Taiwan. Group B streptococcus and E. coli remained the leading pathogens in infants aged 6 months or younger and Salmonella species for those older than 6 months. Copyright (C) 2013, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. All rights reserved

    [[alternative]]Parental Experiences of End-of-Life Care and Bereavement in Pediatric Oncology - Preliminary Study

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    [[abstract]]背景:癌症死亡兒童的家庭會承受極大的痛苦,本研究欲以質性研究探討照顧者在癌症兒童的末期照顧和哀慟的經驗。方法:以立意採樣的方式對四位研究參與者進行單一次半結構式訪談,訪談過程錄音並建立逐字稿文本,透過海德格的此在詮釋學,研究者充分了解在末期照護及哀慟過程所發生的經驗,文本使用ATLAS.ti 9軟體,以Colaizzi的七個步驟分析。根據 Lioncoln 與 Guba 的標準來增加資料的值得信任度。結果:在末期照顧過程中的八個主題包括:尋求可能的治療,或許會有奇蹟、喜樂是良藥,讓日子充滿期待、接受孩子有一天會離開,陪伴他到最後一刻、感到束手無策及無力感、將自己的需求擺在病童之後、醫療團隊看顧家屬的情緒、共患難的家人病友家屬支持、引發正向情緒的回憶。癌症兒童過世後,專屬於孩子的豎靈和告別式可以讓照顧者少一些遺憾。哀慟歷程中的七個主題有:頓失生活重心,強烈空虛感,回憶湧現,表達哀傷的情緒、爸爸面對孩子的離開,以哭泣以外的方式表達哀傷、原有的認知∕習慣∕行為出現改變、保留孩子的東西,守著和孩子的承諾、與有共同回憶的人持續連繫、孩子用一種新的方式,和家人生活在一起、找出失落經驗的意義,並幫助有相似經驗的他人。而父母以開放且誠實的溝通,給予支持,對手足的調適有正向影響。結論:與有共同回憶的醫療團隊及病友家屬持續連繫,是癌症死亡兒童照顧者末期照護及哀慟過程重要的調適資源。[[abstract]]Background: Families who lose a child to cancer endure pain of tremencous proportions. The aim of the qualitative study was to understand how caregivers experienced end-of-life care and bereavement process. The study conduct a qualitative research of caregivers of children with cancer. Methods: In total 4 hemi-structured interviews were conducted using a purposive sampling. The interviews were recorded and transcribed. According to Heidegger’s dasien hermeneutics, the researcher gained full understandings of what happened during the end-of-life care and bereavement process. Texts were analyzed by the method of Colaizzi’s seven steps with ATLAS.ti 9 software. Trustworthiness of the data were assessed according to the criteria of Lincoln and Guba. Results: The themes during end-of-life care include (1) asking for a second opinion; in search of a miracle, (2) a joyful heart is good medicine, (3) accepting the fact that my child will die someday, (4) feeling helpless and self-blame, (5) putting the child’s needs in the first place, (6) emotional supports from the health care providers, (7) supports from other caregivers, and (8) memories with positive emotions. There were 7 themes during bereavement identified: (1) feeling empty inside and getting teary easily, (2) Father was not able to cry, (3) interpersonal changes, (4) preserving the child’s things and keeping a promise, (5) continued contact with health care providers, (6) the child “lives” with the family in a new way, (7) finding out the meanings of the experience and supporting others in the same situation.Conclusion: Ongoing communication and connection with health care providers and caregivers in the same situation were very supportive throughout the entire process

    KubAnomaly: Anomaly detection for the Docker orchestration platform with neural network approaches

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    Kubernetes, which is the most popular orchestration platform for Docker containers, is used widely for developing microservices and automating Docker instance life cycle administration. Because of advancements in containerization technology, a single server can run multiple services and use hardware resources more efficiently. However, containerized environments also bring new challenges in terms of complete monitoring and security provision. Thus, hackers can exploit the security vulnerabilities of containers to gain remote control permissions and cause extensive damage to company assets. Therefore, in this study, we propose KubAnomaly, a system that provides security monitoring capabilities for anomaly detection on the Kubernetes orchestration platform. We develop a container monitoring module for Kubernetes and implement neural network approaches to create classification models that strengthen its ability to find abnormal behaviors such as web service attacks and common vulnerabilities and exposures attacks. We use three types of datasets to evaluate our system, including privately collected and publicly available datasets as well as real‐world experiment data. Furthermore, we demonstrate the effectiveness of KubAnomaly by comparing its accuracy with that of other machine learning algorithms. KubAnomaly is shown to achieve an overall accuracy of up to 96% for anomaly detection. It successfully identifies four real attacks carried out by hackers in September 2018. Moreover, its performance overhead is only 5% greater than that of current methods. In summary, KubAnomaly significantly improves container security by avoiding anomaly attacks

    Modeling Progressive Damage Accumulation in Bone Remodeling Explains the Thermodynamic Basis of Bone Resorption by Overloading

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    Computational modeling of skeletal tissue seeks to predict the structural adaptation of bone in response to mechanical loading. The theory of continuum damage-repair, a mathematical description of structural adaptation based on principles of damage mechanics, continues to be developed and utilized for the prediction of long-term peri-implant outcomes. Despite its technical soundness, CDR does not account for the accumulation of mechanical damage and irreversible deformation. In this work, a nonlinear mathematical model of independent damage accumulation and plastic deformation is developed in terms of the CDR formulation. The proposed model incorporates empirical correlations from uniaxial experiments. Supporting elements of the model are derived, including damage and yielding criteria, corresponding consistency conditions, and the basic, necessary forms for integration during loading. Positivity of mechanical dissipation due to damage is proved, while strain-based, associative plastic flow and linear hardening describe post-yield behavior. Calibration of model parameters to the empirical correlations from which the model was derived is then accomplished. Results of numerical experiments on a point-wise specimen show that damage and plasticity inhibit bone formation by dissipation of energy available to biological processes, leading to material failure that would otherwise be predicted to experience a net gain of bone
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