18 research outputs found
Enhanced self-collimation effect by low rotational symmetry in hexagonal lattice photonic crystals
In this study, we present the design of a photonic crystal (PC) structure
with a hexagonal lattice, where adjustments to the PC unit cell symmetry reveal
an all-angle self-collimation (SC) effect. By optimizing opto-geometric
parameters, such as the rotational angle of auxiliary rods and adjacent
distances, we analyze the SC property in detail, leveraging group velocity
dispersion (GVD) and third-order dispersion (TOD) characteristics. We also
investigate the relationship between symmetry properties and their influence on
dispersion characteristics. Through symmetry manipulation, we gain a
comprehensive understanding of the underlying mechanisms governing light
collimation and confinement in the proposed configurations. The PC structure
with a symmetry group exhibits all-angle SC effect within the range of
and normalized frequencies, with a
bandwidth of . Further breaking the symmetry,
transforming from to group symmetry, enhances the SC bandwidth to
and reveals the perfect linear equi-frequency
contours (EFC) at two different frequency bands: all angle SC between
and normalized frequencies in the 4th
transverse magnetic (TM) band and between and
in the 5th TM band. Additionally, we propose a
composite/hybrid PC structure resembling group symmetry, where two
auxiliary rods are replaced by rectangular photonic wires with the same
refractive index and width equal to the diameter of auxiliary rods. This hybrid
structure exhibits an all-angle SC effect with an operating bandwidth of
, displays near-zero GVD and TOD performance
and offers enhanced robustness against potential fabrication precision issues
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
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
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Visceral Fat Reflects Disease Activity in Patients with Ankylosing Spondylitis
Purpose: Response to infliximab treatment diminishes as body mass index (BMI) increases in patients with ankylosing spondylitis (AS). The purpose of the study was to determine if diminished response to infliximab treatment in patients with AS could be associated with increased visceral adipose tissue rather than increased BMI.
Methods: Twenty six AS patients (21 males and five females) who fulfilled the modified New York criteria and who were currently receiving infliximab treatment were enrolled in the study. Pain was measured by the visual analogue scale (VAS). The disease activity and functional status were assessed by the Bath AS Disease Activity Index (BASDAI) and the Bath AS Functional Index (BASFI). The Bath AS Metrology Index (BASMI) was used to evaluate mobility restrictions. Weight and visceral body composition were measured without shoes in light indoor clothes using a bio-impedance meter.
Results: There was a significant correlation between visceral adipose tissue amount and disease activity under infliximab treatment. In correlation analysis, visceral fat showed significant correlations between BASDAI (r=0.545, p=0.004) and VAS (r=0.458, p=0.019). Total body fat also showed a significant correlation with BASDAI (r=0.463, p=0.017).
Conclusion: A significant correlation was found between visceral adipose tissue amount and disease activity in patients with AS
Effect of Sleep Quality on Hemodynamic Response to Exercise and Heart Rate Recovery in Apparently Healthy Individuals
Purpose: Poor sleep quality has an unfavorable impact on autonomic nervous system activity, especially that of the cardiovascular (CV) system. The heart rate (HR) and blood pressure (BP) at rest and during exercise, along with the heart rate recovery (HRR), were examined in poor sleepers and compared with individuals with good sleep quality.
Methods: A total of 113 healthy individuals were enrolled to the study. All participants performed treadmill stress testing. Sleep quality of participants was assessed by using the Pittsburgh Sleep Quality Index (PSQI) questionnaire: 48 subjects were categorized as ‘poor sleepers’ (PSQI score > 6 points), and the rest were grouped as ‘good sleepers’.
Results: The poor sleepers showed higher resting HR (
Molecular analysis of PROP1, POU1F1, LHX3, and HESX1 in Turkish patients with combined pituitary hormone deficiency: a multicenter study
WOS: 000355230500022PubMed ID: 25500790To investigate the specific mutations in PROP1, POU1F1, LHX3, and HESX1 genes in patients with combined pituitary hormone deficiency (CPHD) in Turkey. Seventy-six patients with CPHD were included in this study. Based on clinical, hormonal, and neuro-radiological data, relevant transcription factor genes were evaluated by Sanger sequencing and multiplex ligation-dependent probe amplification. Total frequency of mutations was 30.9 % in patients with CPHD. Frequency was significantly higher in familial patients (p = 0.001). Three different types of mutations in PROP1 gene (complete gene deletion, c.301-302delAG, a novel mutation; IVS1+2T > G) were found in 12 unrelated patients (21.8 %). Mutations in PROP1 gene were markedly higher in familial than in sporadic cases (58.8 vs. 5.3 %, p < 0.001). Homozygous complete gene deletion was the most common mutation in PROP1 gene (8/12) and was identified in six familial patients. Four different homozygous mutations [p.Q4X, novel mutations; exons 1-2 deletion, p.V153F, p.I244S] were detected in POU1F1 gene. Central precocious puberty was firstly observed in a sporadic-male patient with homozygous POU1F1 (p.I244S) mutation. A homozygous mutation in HESX1 gene (p.R160H) was detected in one patient. This study is the first to investigate specific mutations in CPHD patients in Turkey. Complete deletion in PROP1 gene was the most common mutation encountered in patients with CPHD. We believe that the results of this study will contribute to the establishment of genetic screening strategies in Turkey, as well as to the studies on phenotype-genotype correlations and early diagnosis of CPHD patients.Scientific and Technological Research Institution of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [106S277-SBAG-3488]; Scientific Research Projects Coordination Unit of Istanbul UniversityIstanbul University [2871]This work was supported by Scientific and Technological Research Institution of Turkey (Project Number: 106S277-SBAG-3488) and Scientific Research Projects Coordination Unit of Istanbul University (Project Number: 2871). The authors would like to thank Professor Olcay Neyzi, MD, of the Istanbul Faculty of Medicine, Istanbul University, for helpful discussions and critical reading of the manuscript