Precision Tailoring Quasi-BIC Resonance of a-Si:H Metasurfaces.

The capability of tailoring the resonance wavelength of metasurfaces is important as it can alleviate the manufacturing precision required to produce the exact structure according to the design of the nanoresonators. Tuning of Fano resonances by applying heat has been theoretically predicted in the case of silicon metasurfaces. Here, we experimentally demonstrate the permanent tailoring of quasi-bound states in the continuum (quasi-BIC) resonance wavelength in an a-Si:H metasurface and quantitatively analyze the modification in the Q-factor with gradual heating. A gradual increment in temperature leads to a spectral shift in the resonance wavelength. With the support of ellipsometry measurements, the spectral shift resulting from the short-duration (ten minutes) heating is identified to be due to refractive index variations in the material rather than a geometric effect or amorphous/polycrystalline phase transition. In the case of quasi-BIC modes in the near-infrared, resonance wavelength could be adjusted from T = 350 °C to T = 550 °C without affecting the Q-factor considerably. Apart from the temperature-induced resonance trimming, large Q-factors can be attained at the highest analyzed temperature (T = 700 °C) in the near-infrared quasi-BIC modes. Resonance tailoring is just one of the possible applications of our results. We expect that our study is also insightful in the design of a-Si:H metasurfaces where large Q-factors are required at high temperatures.

Smart Safety Surveillance (3S): Multi-Country Experience of Implementing the 3S Concepts and Principles.

INTRODUCTION: The Smart Safety Surveillance (3S) concept is based on the understanding that, when faced with competing pharmacovigilance priorities, countries will have to invest judiciously, by focusing on new priority products, sharing work and resources with other countries when possible and building national competence for those activities that cannot be delegated. METHOD: The 3S principles were applied to Armenia, Brazil, Ethiopia, India, Peru and Thailand using three priority products: bedaquiline, rotavirus vaccine and tafenoquine. A baseline assessment of pharmacovigilance preparedness was used to identify gaps and establish a work plan. The impact was measured by comparing pre and post 3S-intervention outcomes, which included the number and quality of reports (completeness scores) in the WHO global database of Individual Case Safety Reports, VigiBase, and number of structural indicators met. The implementation period was 9-18 months, ranging from March 2018 (earliest started) until May 2020 (latest). RESULT: An increase in adverse drug reaction (ADR) reporting was demonstrated in Armenia (bedaquiline), Brazil (TB and malaria medicines), India (rotavirus vaccine) and Ethiopia (TB medicines). Completeness scores were above 0.5 at baseline in all countries, and reports improved in quality for Brazil (TB), Peru (malaria), Thailand (malaria) and India (immunization). The number of structural indicators met increased by more than double for Ethiopia. Ethiopia and India demonstrated an increased capacity for signal detection and signal evaluation. Armenia, Brazil, Peru and Thailand showed increased capacity to assess risk management plans following the implementation of 3S principles. CONCLUSION: The 3S concept has demonstrated success in different ways across the six countries. Activities focused on three products for a proof of concept of the 3S principles, with the expectation that the project impact will be sustained through strengthened systems, to guide pharmacovigilance activities of other products in the future. It is important to continue monitoring the countries to understand if the gains and successes of the current 3S project are sustainable.

Structural, optical, and mechanical properties of TiO2 nanolaminates.

The structural, optical, and mechanical properties of TiO2 nanolaminate films grown by plasma-enhanced atomic layer deposition are discussed. Several TiO2/Al2O3 and TiO2/SiO2 compositions have been investigated to study the effect of the relative number of ALD oxide cycles on the film properties to obtain a high refractive index coating with low optical losses, low roughness, and low mechanical stress. The formation of crystalline TiO2 observed at high deposition temperature, or film thickness was inhibited by periodically introducing ultra-thin amorphous layers into the film. Only 4 ALD cycles of Al2O3 (corresponding to ca. 0.5 nm) between 335 ALD cycles of TiO2 (ca. 11 nm) form a closed, distinct layer suppressing the crystallization in TiO2 film. Consequently, the roughness of the pure TiO2 film is reduced from ca. 20 nm rms to 1 nm rms in the 335/4 nanolaminate, with only a slight decrease of the refractive index from 2.46 to 2.44 in 100 nm pure TiO2 and the nanolaminate, respectively. The refractive indices of the nanolaminates in various compositions vary between 2.38 and 2.50 at 632 nm, and the corresponding optical losses from the films are low. The mechanical stress was reduced to about 140 MPa in several TiO2/Al2O3 nanolaminates; however, lower mechanical stress has not been obtained with the studied compositions. The nanolaminate structure is preserved up to 600 °C annealing temperature. After annealing at 800 °C, the individual layers interdiffuse into each other so that no distinct nanolaminate structure is detected. By using TiO2/Al2O3 nanolaminates with reduced mechanical stress, a narrow bandpass filter was realized on various substrates, including half-ball and aspherical lenses.

Light scattering characterization of single-layer nanoporous SiO2 antireflection coating in visible light.

Antireflective coatings are widely applied on transparent optical components to reduce reflections at surfaces. Nanoporous silica (NP SiO2) thin films with tailored refractive index properties are used as single-layer antireflective coatings providing nearly zero reflectivity. In this work, light scattering properties of nanoporous silica single-layer antireflective coatings are investigated in order to determine their optical quality by means of total scattering and detailed roughness analysis. Scattering and roughness characterization of the samples coated with different film thicknesses were realized to distinguish the influences of nanopores and surface roughness on scattering losses in the visible (VIS) spectral range. No significant correlation of scattering losses with the film thickness is found, showing negligible influence of the nanopores to the overall scattering properties compared with the dominating effect of interface roughness. Moreover, the scattering losses from coated fused silica glass were observed as low as 20 ppm (0.002%). It is confirmed that NP SiO2 single-layer antireflective coatings are suitable to be used in optics demanding extremely low scattering characteristics.

The antibiotic knowledge, attitudes and behaviors of patients, doctors and pharmacists in the WHO Eastern European region - a qualitative, comparative analysis of the culture of antibiotic use in Armenia, Georgia, Kazakhstan, Moldova, Russia and Tajikistan.

BACKGROUND: To reduce antimicrobial resistance (AMR), initiatives such as surveillance activities and activities to increase knowledge about how and why antibiotics (ABs) are (mis)used are needed. More surveillance systems are in place in the WHO Western European region than in the Eastern region, and only sparse knowledge exists about the current culture of AB use in the Eastern European countries. OBJECTIVE: To investigate AB knowledge, attitudes and behaviors in countries in the WHO Eastern European region in order to identify overall similarities and differences across the region and how AB knowledge, attitudes and behavior patterns may be influenced by the national health care system. METHODS: Semi-structured interviews were conducted in Armenia, Georgia, Kazakhstan, Moldova, Russia and Tajikistan with patients, doctors and pharmacists. In total, 80 interviews were carried out. A directed content analysis was applied, followed by a comparative analysis, identifying the similarities and differences in AB attitudes, knowledge and behaviors between the countries and discussing how the national health care systems might influence these patterns. RESULTS: Cross-national patterns were identified regarding patients seeking ABs over-the-counter (OTC), patient variations in their requests for ABs when consulting doctors, and, finally, doctors and pharmacists appearing knowledgeable about ABs and their uses, with doctors displaying careful attitudes towards AMR. Indications of national differences between the countries included the ability of patients to afford ABs, prescribing practices of doctors and pharmacist attitudes towards selling ABs without prescriptions. Multiple aspects involved in patient and pharmacist AB decision making were detected, such as various rationales involved in buying/selling ABs OTC, implying that these processes are more complex than previously reported in the literature. CONCLUSIONS: Similarities across the Eastern European region could be seen in patient needs and uses of antibiotics obtained OTC at community pharmacies, whereas doctors appeared more influenced by specific structures of the national healthcare system.

Wide-Angle Broadband Antireflection Coatings Prepared by Atomic Layer Deposition.

A novel broadband antireflective coating with ultra-low residual reflectance for light incidence angles from 0° up to 60° is presented. The system consists of an interference multilayer coating made by atomic layer deposition (ALD) combined with a low- n nanoporous SiO2 top-layer obtained by wet-chemical etching of an atomically mixed SiO2/Al2O3 ALD composite. The average residual reflectance measured at normal incidence for double-sided coated B270 glass substrates is only 0.5% in a broad spectral range from 400 to 1100 nm. The average reflectance of the substrate considering both front and rear sides decreased in the visible spectral range of 420-680 nm from 9.9 and 15.8 to 0.4 and 1.8% at an oblique angle of incidence (AOI) of 45° and 60°, respectively, by applying the hybrid ALD antireflection coatings. The measured average transmittance reaches 99.5% at AOI 6° in the 400-950 nm spectral range. Measurements three weeks after preparation show only a small reduction of the average transmittance to 99.3% in this spectral range spanning 550 nm. Ten months later, the average transmittance is still 99.0%, whereby the sample handling might have also affected the performance. The hybrid ALD system shows excellent conformal AR performance on a strongly curved B270 aspheric lens with a diameter of 50 mm and a height of 25 mm. The presented process is a promising route toward omnidirectional AR coatings on complex 3D optics, which are increasingly important for consumer and high-performance optical systems.

Antimicrobial Medicines Consumption in Eastern Europeand Central Asia - An Updated Cross-National Study and Assessment of QuantitativeMetrics for Policy Action.

Introduction: Surveillance of antimicrobial medicines consumption is central to improving their use and reducing resistance rates. There are few published data on antibiotic consumption in Eastern Europe and Central Asia. To address this, 18 non-European Union (EU) countries and territories contribute to the WHO Regional Office for Europe (WHO Europe) Antimicrobial Medicines Consumption (AMC) Network. Objectives: (i) Analyze 2015 consumption of J01 class antibacterials for systemic use from 16 AMC Network members; (ii) compare results with 2011 data and 2015 ESAC-Net estimates; (iii) assess consumption against suggested indicators; (iv) evaluate the impact of planned changes to defined daily doses (DDDs) in 2019 for some commonly used antibiotics; and (v) consider the utility of quantitative metrics of consumption for policy action. Methods: Analysis methods are similar to ESAC-Net for EU countries. The Anatomical Therapeutic Chemical (ATC) classification and DDD methodology were used to calculate total consumption (DDD/1000 inhabitants/day [DID]), relative use measures (percentages), extent of use of WHO Watch and Reserve group antibiotics and impact of DDD changes. Findings: Total J01 consumption in 2015 ranged 8.0-41.5 DID (mean 21.2 DID), generally lower than in 2011 (6.4-42.3 DID, mean 23.6 DID). Beta-lactam penicillins, cephalosporins, and quinolones represented 16.2-56.6, 9.4-28.8, and 7.5-24.6% of total J01 consumption, respectively. Third-generation cephalosporins comprised up to 90% of total cephalosporin consumption in some countries. Consumption of WHO Reserve antibiotics was very low; Watch antibiotics comprised 17.3-49.5% of total consumption (mean 30.9%). Variability was similar to 2015 ESAC-Net data (11.7-38.3 DID; mean 22.6 DID). DDD changes in 2019 impact both total and relative consumption estimates: total DIDs reduced on average by 12.0% (7.3-35.5 DID), mostly due to reduced total DDDs for commonly used penicillins; impact on rankings and relative use estimates were modest. Discussion: Quantitative metrics of antibiotic consumption have value. Improvements over time reflect national activities, however, changes in total volumes may conceal shifts to less desirable choices. Relative use measures targeting antibiotics of concern may be more informative. Some, including WHO Watch and Reserve classifications, lend themselves to prescribing targets supported by guidelines and treatment protocols.

Mechanical, structural, and optical properties of PEALD metallic oxides for optical applications.

Structural, optical, and mechanical properties of Al2O3, SiO2, and HfO2 materials prepared by plasma-enhanced atomic layer deposition (PEALD) were investigated. Residual stress poses significant challenges for optical coatings since it may lead to mechanical failure, but in-depth understanding of these properties is still missing for PEALD coatings. The tensile stress of PEALD alumina films decreases with increasing deposition temperature and is approximately 100 MPa lower than the stress in thermally grown films. It was associated with incorporation of -OH groups in the film as measured by infrared spectroscopy. The tensile stress of hafnia PEALD layers increases with deposition temperature and was related to crystallization of the film. HfO2 nanocrystallites were observed even at 100°C deposition temperature with transmission electron microscopy. Stress in hafnia films can be reduced from approximately 650 MPA to approximately 450 MPa by incorporating ultrathin Al2O3 layers. PEALD silica layers have shown moderate stress values and stress relaxation with the storage time, which was correlated to water adsorption. A complex interference coating system for a dichroic mirror (DCM) at 355 nm wavelength was realized with a total coating thickness of approximately 2 µm. Severe cracking of the DCM coating was observed, and it propagates even into the substrate material, showing a good adhesion of the ALD films. The reflectance peak is above 99.6% despite the mechanical failure, and further optimization on the material properties should be carried out for demanding optical applications.

Nanoporous SiO2 thin films made by atomic layer deposition and atomic etching.

A new route to prepare nanoporous SiO2 films by mixing atomic-layer-deposited alumina and silica in an Å-scale is presented. The selective removal of Al2O3 from the composites using wet chemical etching with phosphoric acid resulted in nanoporous thin SiO2 layers. A diffusion-controlled dissolution mechanism is identified whereby an interesting reorganization of the residual SiO2 is observed. The atomic scale oxide mixing is decisive in attaining and tailoring the film porosity. The porosity and the refractive index of nanoporous silica films were tailored from 9% to 69% and from 1.40 to 1.13, respectively. The nanoporous silica was successfully employed as antireflection coatings and as diffusion membranes to encapsulate nanostructures.

Antibiotic use in eastern Europe: a cross-national database study in coordination with the WHO Regional Office for Europe.

BACKGROUND: There are no reliable data on antibiotic use in non-European Union (EU) southern and eastern European countries and newly independent states. We aimed to collect valid, representative, comparable data on systemic antimicrobial use in these non-EU countries of the WHO European region. METHODS: Validated 2011 total national wholesale antibiotic-use data of six southern and eastern European countries and regions and seven newly independent states were analysed in accordance with the WHO anatomical therapeutic chemical (ATC)/defined daily doses (DDD) method and expressed in DDD/1000 inhabitants per day (DID). FINDINGS: Total (outpatients and hospital care) antibiotic use ranged from 15·3 DID for Armenia to 42·3 DID for Turkey. Co-amoxiclav was mainly used in Georgia (42·9% of total antibiotic use) and Turkey (30·7%). Newly independent states used substantial quantities of ampicillin and amoxicillin (up to 55·9% of total antibiotic use in Azerbaijan). Montenegro and Serbia were the highest consumers of macrolides (15·8% and 19·5% of total antibiotic use, respectively), mainly azithromycin. Parenteral antibiotic treatment is common practice: 46·4% of total antibiotic use in Azerbaijan (mainly ampicillin; 5·3 DID) and 31·1% of total antibiotic use in Tajikistan (mainly ceftriaxone; 4·7 DID). INTERPRETATION: This study provides publicly available total antibiotic-use data for 13 non-EU countries and areas of the WHO European region. These data will raise awareness of inappropriate antibiotic use and stimulate policy makers to develop action plans. The established surveillance system provides a method to develop quality indicators of antibiotic use and to assess the effect of policy and regulatory actions. FUNDING: Netherlands Ministry of Health, Welfare, and Sport, and EU.

Synthesis and structure elucidation of discotic liquid crystalline perylene imide benzimidazole.

We report the synthesis of a soluble perylene imide benzimidazole (PIBI) and its structural, thermotropic, optical and electrochemical characterization with emphasis on discotic liquid crystalline properties.