Visible-light-induced superhydrophilicity of crystallized WO3 thin films fabricated by using a newly isolated W6+ complex salt of citric acid.

Transparent tungsten trioxide thin films, which demonstrated visible-light (Vis-light)-induced superhydrophilicity, with thicknesses of 100-120 nm, adhesion strengths greater than 49 MPa, bandgap energies of 2.8-2.9 eV, and haze values of 0.4-0.5%, were fabricated using a solution-based process on quartz glass substrates. The precursor solution was prepared by dissolving a W6+ complex salt isolated from a reacted solution of tungstic acid, citric acid, and dibutylamine in H2O, in ethanol. By heating the spin-coated films in air for 30 min at temperatures higher than 500 °C, crystallized WO3 thin films were obtained. The O/W atomic ratio was evaluated to be 2.90, based on the peak area analysis of X-ray photoelectron spectroscopy spectra of the thin-film surfaces, indicating the co-presence of W5+ ions. The water contact angle on film surfaces, which was approximately 25° prior to light irradiation, decreased to less than 10° upon irradiation with 0.06 mW cm-2 Vis-light for only 20 min at 20-25 °C and a relative humidity (RH) of 40-50%. By comparing the contact angle changes at RH values of 20-25%, it was revealed that the interaction between ambient water molecules and the partially O-deficient WO3 thin films plays an important role in achieving photoinduced superhydrophilicity.

Fabrication of Transparent and Conductive SWCNT/SiO2 Composite Thin-Film by Photo-Irradiation of Molecular Precursor Films.

A single-walled carbon nanotube (SWCNT)-silica composite thin film on a quartz glass was formed by ultraviolet irradiation (20-40 °C) onto a spin-coated precursor film. With 7.4 mass% SWCNTs, the electrical resistivity reached 7.7 × 10-3 Ω·cm after UV-irradiation. The transmittance was >80% at 178-2600 nm, and 79%-73% at 220-352 nm. Heat treatment increased the transparency and pencil hardness, without affecting the low electrical resistivity. Raman spectroscopy and microscopic analyses revealed the excellent film morphology with good SWCNT dispersal. The low refractive index (1.49) and haze value (<1.5%) are invaluable for transparent windows for novel optoelectronic devices.

Measuring Public Concern About COVID-19 in Japanese Internet Users Through Search Queries: Infodemiological Study.

BACKGROUND: COVID-19 has disrupted lives and livelihoods and caused widespread panic worldwide. Emerging reports suggest that people living in rural areas in some countries are more susceptible to COVID-19. However, there is a lack of quantitative evidence that can shed light on whether residents of rural areas are more concerned about COVID-19 than residents of urban areas. OBJECTIVE: This infodemiology study investigated attitudes toward COVID-19 in different Japanese prefectures by aggregating and analyzing Yahoo! JAPAN search queries. METHODS: We measured COVID-19 concerns in each Japanese prefecture by aggregating search counts of COVID-19-related queries of Yahoo! JAPAN users and data related to COVID-19 cases. We then defined two indices-the localized concern index (LCI) and localized concern index by patient percentage (LCIPP)-to quantitatively represent the degree of concern. To investigate the impact of emergency declarations on people's concerns, we divided our study period into three phases according to the timing of the state of emergency in Japan: before, during, and after. In addition, we evaluated the relationship between the LCI and LCIPP in different prefectures by correlating them with prefecture-level indicators of urbanization. RESULTS: Our results demonstrated that the concerns about COVID-19 in the prefectures changed in accordance with the declaration of the state of emergency. The correlation analyses also indicated that the differentiated types of public concern measured by the LCI and LCIPP reflect the prefectures' level of urbanization to a certain extent (ie, the LCI appears to be more suitable for quantifying COVID-19 concern in urban areas, while the LCIPP seems to be more appropriate for rural areas). CONCLUSIONS: We quantitatively defined Japanese Yahoo users' concerns about COVID-19 by using the search counts of COVID-19-related search queries. Our results also showed that the LCI and LCIPP have external validity.

Modeling the spread of fake news on Twitter.

Fake news can have a significant negative impact on society because of the growing use of mobile devices and the worldwide increase in Internet access. It is therefore essential to develop a simple mathematical model to understand the online dissemination of fake news. In this study, we propose a point process model of the spread of fake news on Twitter. The proposed model describes the spread of a fake news item as a two-stage process: initially, fake news spreads as a piece of ordinary news; then, when most users start recognizing the falsity of the news item, that itself spreads as another news story. We validate this model using two datasets of fake news items spread on Twitter. We show that the proposed model is superior to the current state-of-the-art methods in accurately predicting the evolution of the spread of a fake news item. Moreover, a text analysis suggests that our model appropriately infers the correction time, i.e., the moment when Twitter users start realizing the falsity of the news item. The proposed model contributes to understanding the dynamics of the spread of fake news on social media. Its ability to extract a compact representation of the spreading pattern could be useful in the detection and mitigation of fake news.

Predicting regional influenza epidemics with uncertainty estimation using commuting data in Japan.

Obtaining an accurate prediction of the number of influenza patients in specific areas is a crucial task undertaken by medical institutions. Infections (such as influenza) spread from person to person, and people are rarely confined to a single area. Therefore, creating a regional influenza prediction model should consider the flow of people between different areas. Although various regional flu prediction models have previously been proposed, they do not consider the flow of people among areas. In this study, we propose a method that can predict the geographical distribution of influenza patients using commuting data to represent the flow of people. To elucidate the complex spatial dependence relations, our model uses an extension of the graph convolutional network (GCN). Additionally, a prediction interval for medical institutions is proposed, which is suitable for cyclic time series. Subsequently, we used the weekly data of flu patients from health authorities as the ground-truth to evaluate the prediction interval and performance of influenza patient prediction in each prefecture in Japan. The results indicate that our GCN-based model, which used commuting data, considerably improved the predictive accuracy over baseline values both temporally and spatially to provide an appropriate prediction interval. The proposed model is vital in practical settings, such as in the decision making of public health authorities and addressing growth in vaccine demand and workload. This paper primarily presents a GCN as a useful means for predicting the spread of an epidemic.

Surveillance of early stage COVID-19 clusters using search query logs and mobile device-based location information.

Two clusters of the coronavirus disease 2019 (COVID-19) were confirmed in Hokkaido, Japan, in February 2020. To identify these clusters, this study employed web search query logs of multiple devices and user location information from location-aware mobile devices. We anonymously identified users who used a web search engine (i.e., Yahoo! JAPAN) to search for COVID-19 or its symptoms. We regarded them as web searchers who were suspicious of their own COVID-19 infection (WSSCI). We extracted the location of WSSCI via a mobile operating system application and compared the spatio-temporal distribution of WSSCI with the actual location of the two known clusters. In the early stage of cluster development, we confirmed several WSSCI. Our approach was accurate in this stage and became biased after a public announcement of the cluster development. When other cluster-related resources, such as detailed population statistics, are not available, the proposed metric can capture hints of emerging clusters.

Robust two-stage influenza prediction model considering regular and irregular trends.

Influenza causes numerous deaths worldwide every year. Predicting the number of influenza patients is an important task for medical institutions. Two types of data regarding influenza-like illnesses (ILIs) are often used for flu prediction: (1) historical data and (2) user generated content (UGC) data on the web such as search queries and tweets. Historical data have an advantage against the normal state but show disadvantages against irregular phenomena. In contrast, UGC data are advantageous for irregular phenomena. So far, no effective model providing the benefits of both types of data has been devised. This study proposes a novel model, designated the two-stage model, which combines both historical and UGC data. The basic idea is, first, basic regular trends are estimated using the historical data-based model, and then, irregular trends are predicted by the UGC data-based model. Our approach is practically useful because we can train models separately. Thus, if a UGC provider changes the service, our model could produce better performance because the first part of the model is still stable. Experiments on the US and Japan datasets demonstrated the basic feasibility of the proposed approach. In the dropout (pseudo-noise) test that assumes a UGC service would change, the proposed method also showed robustness against outliers. The proposed model is suitable for prediction of seasonal flu.

Comparing Medical Term Usage Patterns of Professionals and Search Engine and Community Question Answering Service Users in Japan: Log Analysis.

BACKGROUND: Despite increasing opportunities for acquiring health information online, discussion of the specific words used in searches has been limited. OBJECTIVE: The aim of this study was to clarify the medical information gap between medical professionals and the general public in Japan through health information-seeking activities on the internet. METHODS: Search and posting data were analyzed from one of the most popular domestic search engines in Japan (Yahoo! JAPAN Search) and the most popular Japanese community question answering service (Yahoo! Chiebukuro). We compared the frequency of 100 clinical words appearing in the clinical case reports of medical professionals (clinical frequency) with their frequency in Yahoo! JAPAN Search (search frequency) logs and questions posted to Yahoo! Chiebukuro (question frequency). The Spearman correlation coefficient was used to quantify association patterns among the three information sources. Additionally, user information (gender and age) in the search frequency associated with each registered user was extracted. RESULTS: Significant correlations were observed between clinical and search frequencies (r=0.29, P=.003), clinical and question frequencies (r=0.34, P=.001), and search and question frequencies (r=0.57, P<.001). Low-frequency words in clinical frequency (eg, "hypothyroidism," "ulcerative colitis") highly ranked in search frequency. Similarly, "pain," "slight fever," and "numbness" were highly ranked only in question frequency. The weighted average of ages was 34.5 (SD 2.7) years, and the weighted average of gender (man -1, woman +1) was 0.1 (SD 0.1) in search frequency. Some words were specifically extracted from the search frequency of certain age groups, including "abdominal pain" (10-20 years), "plasma cells" and "inflammatory findings" (20-30 years), "DM" (diabetes mellitus; 30-40 years), "abnormal shadow" and "inflammatory findings" (40-50 years), "hypertension" and "abnormal shadow" (50-60 years), and "lung cancer" and "gastric cancer" (60-70 years). CONCLUSIONS: Search and question frequencies showed similar tendencies, whereas search and clinical frequencies showed discrepancy. Low-clinical frequency words related to diseases such as "hypothyroidism" and "ulcerative colitis" had high search frequencies, whereas those related to symptoms such as "pain," "slight fever," and "numbness" had high question frequencies. Moreover, high search frequency words included designated intractable diseases such as "ulcerative colitis," which has an incidence of less than 0.1% in the Japanese population. Therefore, it is generally worthwhile to pay attention not only to major diseases but also to minor diseases that users frequently seek information on, and more words will need to be analyzed in the future. Some characteristic words for certain age groups were observed (eg, 20-40 years: "cancer"; 40-60 years: diagnoses and diseases identified in health examinations; 60-70 years: diseases with late adulthood onset and "death"). Overall, this analysis demonstrates that medical professionals as information providers should be aware of clinical frequency, and medical information gaps between professionals and the general public should be bridged.

[Caseous Calcification of Mitral Valve Annulus;Report of a Case].

We report a case of an 80-year-old female presenting with a mitral valve tumor. Postoperatively, pathologic diagnosis was caseous calcification of the mitral annulus. In surgery, she successfully underwent a mitral valve replacement with a 20 mm mechanical valve. The importance of correctly making a preoperative diagnosis cannot be over-emphasized. Technical discussion on possibility of mitral valve repair and patient-prosthesis mismatch after mitral valve replacement is also made.

Fenestration using a scoring balloon Scoreflex® as troubleshooting for acute vessel closure due to intramural hematoma complication in percutaneous coronary intervention.

This case report demonstrated the usefulness of scoring balloon when luminal narrowing occurred after balloon angioplasty in the left circumflex artery due to coronary intramural hematoma. Although a stent was placed, coronary flow was not improved. We intended to make a fenestra between the true lumen and the hematoma using a scoring balloon (Scoreflex® 2.0 × 10 mm, OrbusNeich, Tokyo, Japan) which was dilated in the distal segment of the branch. Angiograms showed restoration of TIMI-3 flow with a long dissection spanning from distal of the stent to the scored area. After 3 months and 1 year, follow-up coronary angiograms demonstrated occluded false lumen and good coronary flow in the treated vessel.

Pressure-assisted dissociation and degradation of "proteinase K-resistant" fibrils prepared by seeding with scrapie-infected hamster prion protein.

The crucial step for the fatal neurodegenerative prion diseases involves the conversion of a normal cellular protein, PrP(C), into a fibrous pathogenic form, PrP(Sc), which has an unusual stability against heat and resistance against proteinase K digestion. A successful challenge to reverse the reaction from PrP(Sc) into PrP(C) is considered valuable, as it would give a key to dissolving the complex molecular events into thermodynamic and kinetic analyses and may also provide a means to prevent the formation of PrP(Sc) from PrP(C) eventually in vivo. Here we show that, by applying pressures at kbar range, the "proteinase K-resistant" fibrils (rHaPrP(res)) prepared from hamster prion protein (rHaPrP [23-231]) by seeding with brain homogenate of scrapie-infected hamster, becomes easily digestible. The result is consistent with the notion that rHaPrP(res) fibrils are dissociated into rHaPrP monomers under pressure and that the formation of PrP(Sc) from PrP(C) is thermodynamically controlled. Moreover, the efficient degradation of prion fibrils under pressure provides a novel means of eliminating infectious PrP(Sc) from various systems of pathogenic concern.

Left atrial wall thickness in paroxysmal atrial fibrillation by multislice-CT is initial marker of structural remodeling and predictor of transition from paroxysmal to chronic form.

PURPOSE: We used ECG-gated MSCT to evaluate alterations in the LA wall in patients with paroxysmal atrial fibrillation (AF) (PAF) and compared with chronic AF (CAF) and normal sinus rhythm (NSR). MATERIALS AND METHODS: We enrolled 3 groups, each consisting of 62 patients with either recurrent PAF (48 males, 65 ± 11 years), CAF (43 males, 69 ± 9 years), or NSR without any history of AF (40 males, 64 ± 11 years) for a total of 186 study patients. In CT, the absolute LA wall thickness (LAT) and LA volumes were calculated. RESULTS: In CT, patients with PAF had significantly thicker LAT than those with either CAF or NSR (2.4 ± 0.2mm in PAF >2.1 ± 0.2mm in CAF or 1.9 ± 0.2mm in NSR, p<0.01). Patients with CAF had significantly larger LA volume than those with either PAF or NSR (p<0.01). Subsequently, 9 of the 62 patients with PAF developed CAF over a mean follow-up period of 19 ± 22 months. The mean LAT was significantly thinner in patients who had transitioned from PAF to CAF than in those who had not (2.2 ± 0.2mm and 2.4 ± 0.2mm, respectively) (p<0.01). Receiver operating characteristic analysis demonstrated that the area under the curve for LAT was greater than that for LA volume in CT and LAD in transthoracic echocardiogram. In the Kaplan-Meier analysis, the transition from PAF to CAF was observed more frequently in patients with LAT<2.4mm than LAT ≥ 2.4mm (p=0.018). CONCLUSIONS: Alteration of the LA wall may suggest a part of structural remodeling in AF before the occurrence of LA dilatation. LAT in CT seems to be a useful predictor of the transition from PAF to CAF in patients with PAF.

Quality of coronary arterial 320-slice computed tomography images in subjects with chronic atrial fibrillation compared with normal sinus rhythm.

PURPOSE: To evaluate coronary arterial image quality on 320-slice CT in subjects with chronic atrial fibrillation (CAf) vs. normal sinus rhythm (NSR). MATERIALS AND METHODS: In 92 consecutive subjects, 46 each with CAf (male:female ratio 2.54:1.00, age 69.7 ± 9.9 years) and NSR (male:female ratio 1.88:1.00, age 63.7 ± 13.7 years), 320-slice CT (Aquilion-one) was performed with enhanced images reconstructed at 80% of ECG R-to-R intervals. Visualized coronary vessels >1.5mm diameter in the right coronary artery, left anterior descending (LAD), and circumflex (LCx) distribution were evaluated for length, percentage of length free from motion artifacts, and image quality on a scale ranging from 1 (highest quality) to 5 (lowest quality). RESULTS: LCx length measurements were significantly greater in subjects with NSR (108.8 ± 27.0mm) than CAf (96.6 ± 31.4mm) (P = 0.049), whereas percentages of length free from motion artifacts did not differ between the three vascular beds. Image quality, was significantly but marginally better overall in NSR than in CAF, as well as for LAD and LCx vascular beds. Mean scores in subjects with CAf and NSR were 1.4 ± 0.7 and 1.3 ± 0.6 in all arteries, 1.4 ± 0.7 and 1.2 ± 0.5 in LAD, and 1.5 ± 0.7 and 1.2 ± 0.5 in LCx, respectively (all P<0.001). Despite this difference in image quality, mean scores for both CAf and NSR were weighted toward the high quality end of the scale. CONCLUSION: By 320-slice CT, the overall length of visualized coronary arteries, motion artifact-free length, and image quality using a 5-point scale showed values equal to or slightly lower in CAf than in NSR, but the absolute values were quite acceptable in both groups.

New classification of aortic dissection during the cardiac cycle as pulsating type and static type evaluated by electrocardiogram-gated multislice CT.

PURPOSE: In some four-dimensional images acquired by electrocardiogram (ECG)-gated multislice computed tomography (MSCT) of thoracic aortic dissection (AD), true lumen (TL) gets larger (pulsating-type), whereas in others, TL and false lumen (FL) do not change (static-type) in a cardiac cycle. We have characterized these types. MATERIALS AND METHODS: Twenty subjects (10 with a double-barrel type thoracic descending AD and 10-controls) were enrolled. MSCT covered the thorax, and reconstructed every 10% from 0-90% of the R-R interval. Two physicians measured the TL and FL areas of descending thoracic aorta for each phase at 1) left-pulmonary-artery, 2) left-main-coronary-artery, and 3) right-coronary-artery levels. RESULTS: By designating the pulsating-range acquired from the control data as normal, AD subjects were classified as pulsating or static type when the maximum area of TL was >125% of the minimum TL area at any of the 3 levels. Five subjects were classified as pulsating and 5 as static-type AD. Excluding those with entry at the distal portion of the descending-thoracic-aorta with retrograde flow in FL, the mean-period from onset was 4.3+/-5.9 in the pulsating-type and 42.0+/-13.0 months in the static-type (P<0.05). Percentages with entry at the distal-portion of the descending-thoracic-aorta with retrograde flow in FL in the pulsating-type and static-type were 0% and 40%, respectively. CONCLUSION: In AD, pulsating-type is more common if in the acute-phase from onset or the entry is not located at the distal-portion of descending-thoracic-aorta with retrograde flow in FL. This new classification of AD may usefully differentiate unstable-AD affected by cardiac pulsation from stable-AD.

Positive influence of aging on the occurrence of fat replacement in the right ventricular myocardium determined by multislice-CT in subjects with atherosclerosis.

PURPOSE: We evaluated predictors of fat replacement (FR) in the right-ventricular-myocardium (RVM) determined by MSCT in atherosclerotics not receiving anti-arrhythmia drugs and evaluated the relationship between the presence of FR in the RVM and the occurrence of ventricular premature beats (VPB). MATERIALS AND METHODS: 120-consecutive-atherosclerotics (101-males, 11-85 years) not receiving anti-arrhythmia drugs for VPB, who underwent MSCT for evaluating atherosclerosis and Holter-ECG within one-month, were retrospectively analyzed for FR in the RVM and its relationship with age, body mass index (BMI), and occurrence of VPB. RESULTS: 31-subjects had FR in RVM (18-males; median 67 years), and 89 did not (53-males, median 56 years). Median age was significantly higher in subjects with FR in RVM (P<0.01). The median BMI was 23.0 in subjects with FR and 23.0 in those without (not significant). Average number of VPB by Holter-ECG was 1445 in 31 subjects with FR. Without FR, the average number of VPB was 995. The difference in the numbers of VPB was not significant (P=0.73). A logistic-regression-model using age, male sex and BMI indicated that age was associated with an increased incidence of FR in the RVM (relative risk=1.055, 95% CI 1.019-1.092, P<0.05). CONCLUSIONS: Age but not BMI is significantly associated with the presence of FR in the RVM. Aging might have a positive influence on the occurrence of FR in the RVM as determined by MSCT in atherosclerotics, but FR in the RVM had no influence on the occurrence of VPB.

Acute effect of oral flavonoid-rich dark chocolate intake on coronary circulation, as compared with non-flavonoid white chocolate, by transthoracic Doppler echocardiography in healthy adults.

PURPOSE: To assess the effects of the oral intake of flavonoid-rich dark chocolate on coronary circulation, we measured coronary flow velocity reserve (CFVR) by noninvasive transthoracic Doppler echocardiography (TTDE) in healthy adult subjects. MATERIALS AND METHODS: The study was a randomized, single-blind design conducted for 2 weeks in 39 healthy men (mean age 29.7+/-3.9 years, range 23-40 years). Subjects were randomly assigned a daily intake of either flavonoid-rich dark chocolate (Meiji Black Chocolate 45 g, Meiji Seika kaisya Ltd, including cacao polyphenol 550 mg/day, 200 kcal) or non-flavonoid white chocolate (Meiji White Chocolate 35 g, Meiji Seika kaisya Ltd, including cacao polyphenol 0 mg/day, 140 kcal) as a control. CFVR was recorded by TTDE, and assessed before and after 2 weeks of intake. At the same time, we also assessed serum asymmetric dimethylarginine, 8-isoprostanes, and malondialdehyde-modified low-density lipoprotein (MDA-LDL) as markers of oxidative stress. RESULTS: Flavonoid-rich dark chocolate consumption significantly improved CFVR (3.38+/-0.49 before intake, 4.28+/-0.85 after intake; p<0.01), whereas non-flavonoid white chocolate consumption did not (3.28+/-0.49 before intake, 3.16+/-0.49 after intake; p=0.44). All predictor variables were used as dependent variables in a multiple regression model of the incremental change in CFVR after 2 weeks of chocolate intake. Intake of dark (but not white) chocolate, MDA-LDL, triglyceride (TG) and heart rate (HR) significantly influenced the change of CFVR after 2 weeks of intake (p<0.01) according to the multiple regression formula: Y=1.01X(1)-0.005X(2)-0.003X(3)-0.017X4 (Y=change in CFVR after 2 weeks of chocolate intake, X1=intake of dark (but not white) chocolate, X2=MDA-LDL, X3=TG, X4=HR). CONCLUSION: Flavonoid-rich dark chocolate intake significantly improved coronary circulation in healthy adults, independent of changes in oxidative stress parameters, blood pressure and lipid profile, whereas non-flavonoid white chocolate had no such effects.

Hemangioma located just above the left main coronary artery, in a subject who had cardiac arrest due to ventricular fibrillation, led to a diagnosis of Brugada syndrome.

We report the case of a 38-year-old Asian man with a pericardial hemangioma on the left main coronary artery. The patient presented initially at our hospital after cardiopulmonary resuscitation following an episode of ventricular fibrillation (VF). Because of spontaneous coved-type ST segment elevation on the higher intercostal space V1 to V2 in a 12-lead electrocardiogram, documented VF in the absence of structural heart disease, and a family history of sudden death, he was diagnosed with Brugada syndrome. Transesophageal echocardiography showed a smooth-surfaced mass with well-demarcated borders, directly above the left main coronary artery. Computed tomography confirmed the presence of the mass, which showed no enhancement at early phase, but did demonstrate homogenous enhancement at delay phase by contrast material. There were no findings from either the nuclear medicine or the tumor marker investigations which indicated that the mass located just above the main coronary arteries was malignant. Therefore, taken together, these findings suggested that the tumor might be a pericardial hemangioma. The relationship between the location of the hemangioma just above the left main coronary artery and the occurrence of VF was not clear, i.e. whether the presence of the hemangioma caused the stimulation of the left main coronary artery and as a result, led to the spasm of the left main coronary artery and the occurrence of VF. Furthermore, as the tumor did not extend into any of the adjacent structures, such as the coronary arteries or the right ventricular outflow tract, surgical resection was not performed; instead, the patient received a dual chamber implantable cardioverter-defibrillator.