Dispersion retrieval from multi-level ultra-deep reactive-ion-etched microstructures for terahertz slow-wave circuits

A multi-level microstructure is proposed for terahertz slow-wave circuits, with dispersion relation retrieved by scattering parameter measurements. The measured return loss shows strong resonances above the cutoff with negligible phase shifts compared with finite element analysis. Splitting the circuit into multi levels enables a low aspect ratio configuration that alleviates the loading effect of deep-reactive-ion etching on silicon wafers. This makes it easier to achieve flat-etched bottom and smooth sidewall profiles. The dispersion retrieved from the measurement, therefore, corresponds well to the theoretical estimation. The result provides a straightforward way to the precise determination of dispersions in terahertz vacuum electronics.</jats:p

Vitamin D and Exercise Are Major Determinants of Natural Killer Cell Activity, Which Is Age- and Gender-Specific

BackgroundThe coronavirus-19 disease (COVID-19) pandemic reminds us of the importance of immune function, even in immunologically normal individuals. Multiple lifestyle factors are known to influence the immune function.ObjectiveThe aim was to investigate the association between NK cell activity (NKA) and multiple factors including vitamin D, physical exercise, age, and gender.MethodsThis was a cross-sectional association study using health check-up and NKA data of 2,095 subjects collected from 2016 to 2018 in a health check-up center in the Republic of Korea. NKA was measured using the interferon-γ (IFN-γ) stimulation method. The association of NKA with 25-(OH)-vitamin D (25(OH)D) and other factors was investigated by multiple logistic regression analysis.ResultsThe average age of subjects was 48.8 ± 11.6 years (52.9% of subjects were female). Among 2,095 subjects, 1,427 had normal NKA (NKA ≥ 500 pg IFN-γ/mL), while 506 had low NKA (100 ≤ NKA &lt; 500 pg/mL), and 162 subjects had very low NKA (NKA &lt; 100 pg/mL). Compared to men with low 25(OH)D serum level (&lt; 20 ng/mL), vitamin D replete men (30–39.9 ng/mL) had significantly lower risk of very low NKA (OR: 0.358; 95% CI: 0.138, 0.929; P = 0.035). In women, both low exercise (OR: 0.529; 95% CI: 0.299, 0.939; P = 0.030) and medium to high exercise (OR: 0.522; 95% CI: 0.277, 0.981; P = 0.043) decreased the risk compared to lack of physical exercise. Interestingly, in men and women older than 60 years, physical exercise significantly decreased the risk. Older-age was associated with increased risk of very low NKA in men, but not in women.ConclusionPhysical exercise and vitamin D were associated with NKA in a gender- and age-dependent manner. Age was a major risk factor of very low NKA in men but not in women

Fabrication of Deterministic and Random Surfaces Using 3-D Printing Technology for Psychophysical Studies of Roughness Perception

For psychophysical studies of roughness perception, it is vital of importance to efficiently fabricate the sample surfaces that have different levels of physical roughness. In this context, the present study seeks to develop an efficient way of fabricating such sample surfaces using 3-D printing technology, which consists surface modeling, 3-D printing and measurement. Reliability of this method is ensured by conducting a psychophysical experiment with the samples fabricated using the developed method and comparing the results with those of the previous studies.Published versio

Decision support for selecting exportable nuclear technology using the analytic hierarchy process: A Korean case

The Korean government plans to increase strategically focused R&D investment in some promising nuclear technology areas to create export opportunities of technology in a global nuclear market. The purpose of this paper is to present a decision support process for selecting promising nuclear technology with the perspective of exportability by using the AHP based on extensive data gathered from nuclear experts in Korea. In this study, the decision criteria for evaluating the export competitiveness of nuclear technologies were determined, and a hierarchical structure for the decision-making process was systematically developed. Subsequently relative weights of decision criteria were derived using AHP methodology and the export competitiveness of nuclear technology alternatives was quantified to prioritize them. We discuss the implications of our results with a viewpoint toward national nuclear technology policy.Technology selection Nuclear technology Analytic hierarchy process

Spatial Equality and Equity for Effective Emergency Water Distribution System: Points of Distribution

In recent years, there have been multiple incidents of drinking water contamination reported in major US cities. A critical part of the response to such an emergency is the distribution of bottled water to affected residents via points of distribution (PODs). However, in all of these instances the locations of the PODs and the limited transportation options of the residents meant that some residents had less accessibility to the PODs to obtain the clean water they needed. Unfortunately, current policies and regulations fail to consider spatial equity in determining placement of PODs. Thus, this study investigates the effectiveness of POD locations from the perspectives of spatial equality and spatial equity. We present a binary linear programming model that considers travel distance-based and time-based accessibility measurements simultaneously to find the optimal location of capacitated public facilities. The proposed model is applied to the Flint, Michigan, water crisis. Our results show the effects of POD locations and census block groups assigned to PODs on spatial equality and spatial equity, and the model&apos;s ability to improve accessibility measurements. In particular, the proposed model is able to decrease travel time-based assessment and distance-based assessment by up to 12.5% and 12.24% respectively. Also, our results demonstrate the combined impact of different levels of capacity and numbers of PODs with different allowable levels of accessibility on an efficient emergency water distribution system. The results of this study offer emergency agencies and policy makers an avenue toward better guidelines and policies for an effective emergency drinking water distribution system

Current Limitations and Recent Progress in Nanomedicine for Clinically Available Photodynamic Therapy

Photodynamic therapy (PDT) using oxygen, light, and photosensitizers has been receiving great attention, because it has potential for making up for the weakness of the existing therapies such as surgery, radiation therapy, and chemotherapy. It has been mainly used to treat cancer, and clinical tests for second-generation photosensitizers with improved physicochemical properties, pharmacokinetic profiles, or singlet oxygen quantum yield have been conducted. Progress is also being made in cancer theranostics by using fluorescent signals generated by photosensitizers. In order to obtain the effective cytotoxic effects on the target cells and prevent off-target side effects, photosensitizers need to be localized to the target tissue. The use of nanocarriers combined with photosensitizers can enhance accumulation of photosensitizers in the tumor site, owing to preferential extravasation of nanoparticles into the tumor vasculature by the enhanced permeability and retention effect. Self-assembly of amphiphilic polymers provide good loading efficiency and sustained release of hydrophobic photosensitizers. In addition, prodrug nanomedicines for PDT can be activated by stimuli in the tumor site. In this review, we introduce current limitations and recent progress in nanomedicine for PDT and discuss the expected future direction of research

Current Limitations and Recent Progress in Nanomedicine for Clinically Available Photodynamic Therapy

Photodynamic therapy (PDT) using oxygen, light, and photosensitizers has been receiving great attention, because it has potential for making up for the weakness of the existing therapies such as surgery, radiation therapy, and chemotherapy. It has been mainly used to treat cancer, and clinical tests for second-generation photosensitizers with improved physicochemical properties, pharmacokinetic profiles, or singlet oxygen quantum yield have been conducted. Progress is also being made in cancer theranostics by using fluorescent signals generated by photosensitizers. In order to obtain the effective cytotoxic effects on the target cells and prevent off-target side effects, photosensitizers need to be localized to the target tissue. The use of nanocarriers combined with photosensitizers can enhance accumulation of photosensitizers in the tumor site, owing to preferential extravasation of nanoparticles into the tumor vasculature by the enhanced permeability and retention effect. Self-assembly of amphiphilic polymers provide good loading efficiency and sustained release of hydrophobic photosensitizers. In addition, prodrug nanomedicines for PDT can be activated by stimuli in the tumor site. In this review, we introduce current limitations and recent progress in nanomedicine for PDT and discuss the expected future direction of research

Extended Data Pipeline for Circular Economy Monitoring

Circular economy (CE) and sustainability are high on the political agenda of governments nationally and internationally. Governments are developing instruments to stimulate the CE, but without monitoring in place, these measures can be subject to abuse, failing to achieve the desired effects. CE monitoring, however, is still a nascent topic in academic literature. In this paper we propose the concept of the extended data pipeline to support CE visibility. Governments, but also banks and auditing firms can use this visibility to monitor CE flows to design and evaluate instruments and measures to enhance the CE

Roll-to-roll-compatible, flexible, transparent electrodes based on self-nanoembedded Cu nanowires using intense pulsed light irradiation

Copper nanowire (Cu NW)-based flexible transparent conductive electrodes (FTCEs) have been investigated in detail for use in various applications such as flexible touch screens, organic photovoltaics and organic light-emitting diodes. In this study, hexadecylamine (HDA) adsorbed onto the surface of NWs is changed into polyvinylpyrrolidone (PVP) via a ligand exchange process; the high-molecular-weight PVP enables high dispersion stability. Intense pulsed light (IPL) irradiation is used to remove organic species present on the surface of the NWs and to form direct connections between the NWs rapidly without any atmospheric control. NWs are self-nanoembedded into a plastic substrate after IPL irradiation, which results in a smooth surface, strong NW/substrate adhesion, excellent mechanical flexibility and enhanced oxidation stability. Moreover, Cu NW FTCEs with high uniformities are successfully fabricated on a large area (150 mm × 200 mm) via successive IPL irradiation that is synchronized with the motion of the sample stage. This study demonstrates the possibility of roll-to-roll-based, large-scale production of low-cost, high-performance Cu NW-based FTCEs. © The Royal Society of Chemistry 2016.

Realizing value from voluntary business-government information sharing through blockchain-enabled infrastructures: The case of importing tires to the Netherlands using TradeLens

Blockchain technology has emerged as new technology and governments are now exploring its potential for realizing value. In recent years, studies have focused on identifying opportunities and barriers of blockchain-based applications for government, and multiple piloting initiatives have been started to experiment and test the potential of this technology. Nevertheless, many of these blockchain initiatives are in the pilot stage. For the initiatives that have reached a large-scale implementation or production stage, these are largely on a local (municipal) or national level. There is limited research on operational blockchain-enabled infrastructures implemented on a global level and how they can be used by government organizations to create value. This is an area that we set out to explore with this paper. In this paper, we take the specific focus on business-government information sharing via a global blockchain-enabled platform (TradeLens) to create value for business and government. As a case study, we focus on examining the case of importing tires from China to the Netherlands and the value creation processes for the tire importer and customs enabled by information sharing via the TradeLens platform. From a theoretical perspective, building on two models that have been published earlier, we propose a framework that explicitly allows to link and reason about business-government information sharing enabled by blockchain, how it enables value creation for both business and government, and the technical blockchain design choices that are linked to this value creation process