In this paper, the design and optimization of a circularly polarized antenna based on two crossed dipoles in phase quadrature for Global Navigation Satellite System (GNSS) wide band application has been investigated. The proposed design is single fed and relies on parasitic structures to achieve wide band coverage on the GPS standard bands L1 (1559–1610 MHz) and L5 (1164–1189 MHz). Full-wave simulations have been used to compute the radiation properties and the impedance of the antenna. A prototype was manufactured, and good agreement has been observed between the simulated results and measurement for both radiation pattern and reflection coefficient.

The antenna achieves a −10 dB impedance bandwidth of $56.97\%$ covering the band 1164–1610 MHz, and an axial ratio that covers the L5 band ranging between 7 dB and 2.8 dB from 1.164 GHz to 1.3 GHz while maintaining a value below 2.7 dB across the entire L1 band. The antenna occupies a volume of $\,99\, \,\times\,99\, \times 50$ mm3. It has been tested in real conditions during the 23rd French National Microwave Days (JNM) student competition. A GNSS signal receiver has been connected to the antenna. The antenna has been evaluated based on the number of connections it could achieve over a duration of 30 s.

The COVID-19 pandemic led to an initial increase in the incidence of carbapenem-resistant Enterobacterales (CRE) from clinical cultures in South-East Asia hospitals, which was unsustained as the pandemic progressed. Conversely, there was a decrease in CRE incidence from surveillance cultures and overall combined incidence. Further studies are needed for future pandemic preparedness.

Dust storms are typical dispersed two-phase atmospheric turbulence involving electrified charged dust particles. Previous observations have demonstrated that clean-air atmospheric turbulence is strongly intermittent. However, the intermittency of the wind velocity, concentration of dust particles with a diameter smaller than $10\ \mathrm {\mu }{\rm m}$ (PM10) and electric fields, known as multifield intermittency, has not been reported or characterized yet. Here, we quantify the small-scale multifield intermittency of dust storms using datasets obtained from the Qingtu Lake Observation Array and a wavelet-based data analysis technique. The results indicate that the probability density functions of the multifield increments are scale dependent, and the scaling exponents of the multifield structure functions exhibit anomalous scaling, suggesting that the multiple fields in dust storms are also highly intermittent. Specifically, the wind velocity during dust storms appears to be more intermittent as compared with clean-air conditions. Among the multiple fields, the small-scale intermittency is strongest for PM10 dust concentration, moderate for electric fields and weakest for wind velocity. Furthermore, the anomalous scaling of multiple fields is well described by the hierarchical structure theory of turbulence. It is theoretically predicted that the wind velocity displays a one-dimensional filamentary structure, while the PM10 dust concentration and electric fields display two-dimensional sheet-like structures. Finally, after removing the coherent components of the observed time series by the proposed wavelet conditioning statistics, Kolmogorov linear scaling is recovered for the multiple fields, suggesting that small-scale multifield intermittency is caused by the presence of small-scale coherent structures.

Objectives: HCWs are recommended to wipe the computers with alcohol wipes before clinical use. Compliance assessment by direct observation is resource intensive. We used ATP measurement as a surrogate to assess the compliance to preutilization cleaning of computers. Methods: We conducted a pilot study to determine the median relative light unit (RLU) value reflective of preutilization cleaning of the computers. We identified values of <250, 250–500, and >500 RLU to reflect cleaned, probably cleaned, and not cleaned computers, respectively. Subsequently, we conducted a cross-sectional study of the computers in the inpatient wards in Tan Tock Seng Hospital and National Centre for Infectious Diseases. Using 3M Clean-Trace ATP swabs, we tested 5 computers in each ward: 2 computers on wheels, 2 from the nursing station, and 1 at the patients’ room entrance. All analyses were conducted using STATA version 15 software. Results: Between October 4 and 10, 2021, we collected 219 samples from 219 computers. Among them, 44 (20.1%) were cleaned, 49 (22.4%) were probably cleaned, and 126 (57.5%) computers were not cleaned. Higher compliance to computer cleaning was observed in COVID-19 wards [85 ATP samples; cleaned, 37 (43.5%); probably cleaned, 26 (30.6%); not cleaned, 22 (25.9%)] compared with non–COVID-19 wards [134 ATP samples; cleaned, 7 (5.2%); probably cleaned, 23 (17.2%); not cleaned, 104 (77.6%)] (P < .01). No significant difference was observed in compliance with cleaning computers between the ICU [30 ATP samples; cleaned, 7 (23.3%); probably cleaned, 4 (13.3%); not cleaned, 19 (63.3%)] and general wards [189 ATP samples; cleaned, 37 (19.6%); probably cleaned, 45 (23.8%); not cleaned, 107 (56.6%)] (P = .47). Conclusions: ATP swab tests can be used as a surrogate marker to assess compliance to pre-utilization cleaning of computers. Enhanced awareness of environmental hygiene may explain the higher compliance to computer cleaning observed in COVID-19 wards.

Objectives: The use of handwashing sinks for activities other than hand hygiene (HH) is associated with higher rates of β-lactamase–producing Enterobacteriaceae. However, little has been published about the handwashing sink activities in Singapore hospitals. We explored the handwashing sink activities in a tertiary-care hospital in Singapore. Methods: Five trained shadow observers conducted this observational study between December 18 and 21, 2018 (6 hours per day: 07:00–09:00, 09:30–11:30, and 12:30–14:30) in acute-care general wards. We divided the handwashing sink activities by healthcare workers (HCWs) and non-HCWs (ie, visitors, caregivers, and relatives) and by HH- and non–HH-related activities. We used Stata version 15 software for the analysis. The study was approved by the Institutional Review Board of the National Healthcare Group, Singapore (DSRB no. 2020/01257). Results: In total, 657 handwashing sink activities were recorded [HCWs, 475 (72.3%) and non-HCWs, 182 (27.7%)]. Of the 475 HCW handwashing sink activities, 451 (94.9%) were HH-related, 10 (2.1%) were for patient nutrition, 7 (1.5%) were for environmental care, 6 (1.3%) were for medical equipment cleaning, and 1 (0.2%) was patient personal-item cleaning. Of the 182 handwashing sink activities by non-HCWs, 117 (64.3%) were HH related, 30 (16.5%) were for patient nutrition, 21 (11.5%) were for personal hygiene, 14 (7.7%) were patient personal-item cleaning. The distribution of handwashing sink activities differed significantly (P < .01) between HCWs and non-HCWs. The odds of non–HH-related handwashing sink activities among non-HCWs was 10× higher than among HCWs (OR, 10.44; 95% CI, 5.98–18.23; P < .01). Conclusions: Handwashing sinks use for non–HH-related activities is higher among non-HCWs than HCWs. Further studies are needed to understand the impact of non-HH handwashing sink activities on nosocomial infections and ways to reduce them.

Objectives: In healthcare facilities, environmental reservoirs of CPE are associated with CPE outbreaks. In the newly built NCID building, we studied the introduction of CPE in the aqueous environment. Methods: We sampled the aqueous environments (ie, sink, sink strainer, and shower drain-trap with Copan E-swabs and sink P-trap water) of 4 NCID wards (ie, 2 multidrug-resistant organism (MDRO) wards and 2 non-MDRO wards). Two sampling cycles (cycle 1, June–July 2019 and cycle 2, September–November 2019) were conducted in all 4 wards. Cycle 3 (November 2020) was conducted in 1 non-MDRO ward to investigate CPE colonization from previous cycles. Enterobacterales were identified using MALDI-TOF MS and underwent phenotypic (mCIM and eCIM) and confirmatory PCR tests for CPE. Results: We collected 448, 636, and 96 samples in cycles 1, 2, and 3, respectively. MDRO and non-MDRO wards were operational for 1 and 7 months during the first sampling cycle. The CPE prevalence rates in MDRO wards were 1.67% (95% CI, 0.46% – 4.21%) in cycle 1 and 1.76% (95% CI, 0.65% – 3.80%) in cycle 2. In the aqueous environments in MDRO wards, multiple species were detected (cycle 1: 2 K. pneumoniae, 1 E. coli, and 1 S. marcescens; cycle 2: 5 K. pneumoniae and 1 R. planticola), and multiple genotypes were detected (cycle 1: 3 blaOXA48; cycle 2: 5 blaOXA48 and 1 blaKPC). The CPE prevalence in non-MDRO wards was 1.92% (95% CI, 0.53%–4.85%) in cycle 1. The prevalence rate increased by 5.51% (95% CI, 1.99%–9.03%) to 7.43% (95% CI, 4.72%–11.04%; P = .006) in cycle 2, and by another 2.98% (95% CI, −3.82% to 9.79%) to 10.42% (95% CI, 5.11% – 18.3%; P = .353) in cycle 3. Only blaOXA48 S. marcescens were detected in all cycles (except 1 blaOXA48 K. pneumoniae in cycle 2) in the non-MDRO ward. Conclusions: CPE established rapidly in the aqueous environment of NCID wards, more so in MDRO wards than non-MDRO wards. Longitudinal studies to understand the further expansion of the CPE colonization and its impact on patients are needed.

Objectives: The increase in carbapenemase-producing organism (CPO) transmission among hospitalized patients is a growing concern. Studies investigating the transmission of CPO to epidemiologically linked contacts are scarce. We conducted an interim subgroup analysis of the ongoing multicenter household transmission of CPO in Singapore (CaPES-C) study to identify the acquisition rate of CPO among epidemiologically linked contacts of hospitalized CPO patients. Methods: This multicenter prospective cohort study was conducted between January and December 2021. We recruited CPO-positive patients and their epidemiologically linked contacts. Stool samples were collected from the patients at baseline, day 3, day 7, and at weeks 2, 3, 4, 5, 6, 12, 24, 36, and 48. Additionally, a sample was collected at the time of discharge from the hospital. Xpert Carba-R test was used to detect CPO genotypes in the stool samples. In this interim analysis, we calculated the acquisition rate of CPO among the epidemiologically linked hospital contacts of CPO positive patients using Stata version 15 software. Results: We recruited 22 (56.4%) CPO-positive index patients [blaNDM, n = 7 (31.8%); blaIMP, n = 3 (13.6%); blaOXA-48, n = 10 (45.5%), others, n = 2 (9.1%)] and 14 (35.9%) epidemiologically linked hospital contacts. The median age of CPO-positive patients was 72.5 years (IQR, 62–82) and 15 (68.2%) were female. The median age for the epidemiologically linked contacts was 82.5 years (IQR, 70–85) and 4 (28.6%) were female. After 1,082 patient days, 2 (14.3%) epidemiologically linked contacts tested positive for CPO giving an acquisition rate of 1.85 per 1,000 patient days (95% CI, 0.46 – 7.39). One of these participants acquired a concordant genotype (blaOXA-48) at day 7 and the other acquired a discordant genotype (CPO positive index, blaIMP; epidemiologically linked contact, blaNDM) at week 12 of follow-up. Conclusions: This small interim analysis revealed a high conversion rate among epidemiologically linked hospital contacts. A larger study is needed to understand the influence of genotypes, hospital environment, and human behavior on the transmission of CPO in hospitals.

Disturbances in lipid metabolism are at the core of several health issues facing modern society, including fatty liver and obesity. The sterol regulatory element-binding protein 1 (SREBP-1) is one important transcription factor regulating lipid metabolism, but the relevant mechanism still remains unknown. The present study determined the transcriptional regulation of SREBP-1 and its target genes (including acetyl-CoA carboxylase α (accα), fatty acid synthase (fas) and stearoyl-CoA desaturase 1 (scd1)) in a freshwater teleost, grass carp Ctenopharyngodon idella. We cloned and characterised the 1988 bp, 2043 bp, 1632 bp and 1889 bp sequences of srebp-1, accα, scd1 and fas promoters, respectively. A cluster of putative binding sites of transcription factors, such as specific protein, yin yang 1, nuclear factor Y, sterol response elements (SRE) and enhancer box (E-box) element, were predicted on their promoter regions. Overexpression of nSREBP-1 reduced srebp-1 promoter activity, increased scd1 and fas promoter activity but did not influence accα promoter activity. The site-mutation and electrophoretic mobility shift assay analysis indicated that srebp-1, fas and scd1 promoters, but not accα promoter, possessed SRE. In Ctenopharyngodon idella kidney (CIK) cells of grass carp, nSREBP-1 overexpression significantly reduced srebp-1 mRNA expression and up-regulated miR-29 mRNA expression. The 3′UTR of srebp-1 possessed the potential miR-29 binding site and miR-29 up-regulated the luciferase activity of srebp-1 3′UTR and srebp-1 mRNA expression, implying a self-activating loop of SREBP-1 and miR-29 in grass carp. Based on the above-mentioned results, we found two novel transcriptional mechanisms for SREBP-1 in grass carp: (1) the auto-regulation sited on the SREBP-1 promoter regions was suppressive and (2) there was a self-activating loop of SREBP-1 and miR-29.

Reproduction of Varroa jacobsoni Oudemans has been extensively studied in colonies of the mite's recently acquired host, Apis mellifera Linnaeus. However, data on reproduction in colonies of its original host, A. cerana Fabricius, are still fragmentary. In order to compare reproductive success in naturally infested brood cells of A. cerana and A. mellifera, freshly capped worker and drone cells (0–5 h after capping) were marked and opened 9 days later. When one or more foundress Varroa mites were found, the number and stage of the offspring were recorded. In colonies of A. cerana, V. jacobsoni reproduced almost exclusively in drone cells. Surprisingly, however, these drone cells proved to be better suited for reproduction than drone (and worker) cells of A. mellifera. Firstly, in drone cells of A. cerana, 97–100% of the mites produced daughters and 98–99% of these mites also produced a son. In drone and worker cells of A. mellifera only 70–80% produced daughters and only 74–86% of these mites produced a son. Secondly, if a mite produced daughters, she produced more daughters in drone cells of A. cerana than in drone cells of A. mellifera: 4.5–4.6 vs 2.9–3.7 daughters per mite, respectively. Finally, infestation by two foundress females negatively affected reproduction per mite in drone cells of A. mellifera, but not in drone cells of A. cerana. Thus, V. jacobsoni seems to be better adapted to A. cerana than to A. mellifera, although population growth of mites in A. mellifera colonies is higher due to the exploitation of worker cells besides drone cells.

Ion beam nitridation (IBN) of GaAs at room temperature was studied as a function of N2+ ion incident angle at ion energy of 10 keV. The ion beam bombardment surface area of GaAs was characterized in situ by both Auger electron spectroscopy (AES) and small spot-size x-ray photoelectron spectroscopy (XPS). Thin GaN reaction layers are formed at all N2+ ion incident angles, whereas the formation of As–N bonds has not been found. However, the degree of nitridation of Ga decreases with increasing incident angle. The observed angular dependence of the N incorporation can be explained in terms of sputtering yield, indicating that the growth kinetics can be described as a dynamic process comprising the accumulation of N and sputter removal of the surface layer. N2+ ion bombardment causes the depletion of As from the surface region because of the preferential sputtering of As from GaAs. The preferential sputtering of As reduces with increasing N2+ ion incident angle. The angular dependent behavior of preferential sputtering of As by 10 keV N2+ ions can be attributed to the angular dependence of GaN surface layer formation.

Secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS) are used to investigate Ti silicide formation mechanisms on a series of Ti on Si thin films annealed in ultrahigh vacuum (UHV) at different temperatures and durations. The competition between oxygen diffusion and the silicide formation reaction (the socalled “snowplough” effect) is observed directly, as well as a Ti-Si-O layer. The results from these controlled experiments are compared with those from Ti silicide films formed under rapid thermal annealing (RTA) conditions in a production furnace, with and without a TiW barrier layer.