ABSTRACT
Translational regulation in tissue environments during in vivo viral pathogenesis has rarely been studied due to the lack of translatomes from virus-infected tissues, although a series of translatome studies using in vitro cultured cells with viral infection have been reported. In this study, we exploited tissue-optimized ribosome profiling (Ribo-seq) and severe-COVID-19 model mice to establish the first temporal translation profiles of virus and host genes in the lungs during SARS-CoV-2 pathogenesis. Our datasets revealed not only previously unknown targets of translation regulation in infected tissues but also hitherto unreported molecular signatures that contribute to tissue pathology after SARS-CoV-2 infection. Specifically, we observed gradual increases in pseudoribosomal ribonucleoprotein (RNP) interactions that partially overlapped the trails of ribosomes, being likely involved in impeding translation elongation. Contemporaneously developed ribosome heterogeneity with predominantly dysregulated 5 S rRNP association supported the malfunction of elongating ribosomes. Analyses of canonical Ribo-seq reads (ribosome footprints) highlighted two obstructive characteristics to host gene expression: ribosome stalling on codons within transmembrane domain-coding regions and compromised translation of immunity- and metabolism-related genes with upregulated transcription. Our findings collectively demonstrate that the abrogation of translation integrity may be one of the most critical factors contributing to pathogenesis after SARS-CoV-2 infection of tissues.
Subject(s)
COVID-19 , Animals , Mice , RNA, Messenger/genetics , COVID-19/genetics , SARS-CoV-2/genetics , Protein Biosynthesis , Lung/metabolismABSTRACT
Introduction: Once the underlying pathology has been identified, pulsatile tinnitus (PT) can be treated successfully with surgical or interventional management. However, some patients experience residual or recurrent symptoms following initially successful surgical treatment, and require revision surgery or additional procedures. Here, we report a case series of patients who had undergone revision surgery or interventional treatment, and suggest possible ways of minimizing the need for revision. Methods: Between January 2014 and March 2023, a total of seven subjects underwent revision surgery or interventional treatment for persistent or recurrent PT after initial surgical treatment. Demographic data, reasons for revision, and changes in symptoms before and after revision were analyzed retrospectively. Temporal bone computed tomographic angiography images were reviewed to identify the causes and reasons for revision. Results: Of the seven subjects, six underwent sigmoid sinus (SS) resurfacing/reshaping due to ipsilateral diverticulum (Div) or dehiscence (Deh), and one underwent jugular bulb (JB) resurfacing due to a high-riding JB with bony Deh. Of the five subjects who underwent revision SS surgery due to recurrent SS-Div or SS-Deh, three showed marked resolution of PT, while the other two showed partial improvement of the symptoms. One subject who underwent revision JB resurfacing, and another who underwent additional transarterial embolization for a concurrent ipsilateral dural arteriovenous fistula, reported marked improvement of PT. Discussion: The possibility of recurrence should be taken into account when performing surgical intervention in patients with PT. The likelihood of recurrence can be minimized through a comprehensive evaluation to identify possible multiple etiologies, and through the use of durable materials and appropriate surgical methods.
ABSTRACT
To reconstruct an ideal full-thickness skin model, basal keratinocytes must be distributed as a confluent monolayer on the dermis. However, the currently available extrusion bioprinting method for the skin is limited when producing an air-exposed cellular monolayer because the cells are encapsulated within a bioink. This is the first study to use sacrificial gelatin-assisted extrusion bioprinting to reproduce a uniform and stratified epidermal layer. Experimental analyses of the rheological properties, printability, cell viability, and initial keratinocyte adhesion shows that the optimal gelatin bioink concentration is 4 wt.%. The appropriate thickness of the bioprinted gelatin structure for achieving a confluent keratinocyte layer is determined to be 400 µm. The suggested strategy generates a uniform keratinocyte monolayer with tight junctions throughout the central and peripheral regions, whereas manual seeding generates non-uniform cellular aggregates and vacancies. These results influence gene expression, exhibiting a propensity for epidermal differentiation. Finally, the gelatin-assisted keratinocytes are bioprinted onto a dermis composed of gelatin methacryloyl and dermis-derived decellularized extracellular matrix to establish a full-thickness skin model. Thus, this strategy leads to significant improvements in epidermal differentiation/stratification. The findings demonstrate that the gelatin-assisted approach is advantageous for recreating reliable full-thickness skin models with significant consistency for mass production.
Subject(s)
Bioprinting , Bioprinting/methods , Gelatin/chemistry , Skin , Epidermis , Hydrogels/chemistry , Tissue Engineering/methods , Printing, Three-Dimensional , Tissue Scaffolds/chemistryABSTRACT
OBJECTIVES: Topical lidocaine remains the mainstay for anesthesia in transcutaneous vocal fold injection (VFI). While using topical lidocaine, laryngologists sometimes encounter uncontrolled reflexes or poor compliance. Superior laryngeal nerve block (SLNB) provides deep and rapid anesthesia on the larynx above the vocal folds and abolishes the glottic closure reflex. Herein, we present a pilot study to evaluate the feasibility and safety of SLNB for transcutaneous VFI and explored its usefulness. METHODS: Fifty-nine patients were prospectively anesthetized with SLNB during transcutaneous VFI for unilateral vocal fold paralysis. In the SLNB group, 0.5 to 1 mL of 2% lidocaine was infiltrated on bilateral SLNs through the thyrohyoid membrane. As the control group, we included previous 47 patients who underwent VFI with topical lidocaine. In the control group, 10% lidocaine spray was applied to the laryngopharyngeal mucosa. Demographic data, laryngeal exposure, patient compliance, procedural interruption, and complications were investigated. Patient compliance was evaluated based on the frequency of cough and swallowing during VFI procedures. RESULTS: SLNB enabled endoscopic contact on the epiglottis and pharyngeal wall without gag reflex and provided good exposure of the procedure field on the vocal folds. In the SLNB group, the laryngeal exposure is significantly better than in the control (P = 0.005). The frequency of cough and swallowing was significantly lower in the SLNB group than in the control (P < 0.001). The number of procedural interruptions was lower in the SLNB group than in the control (P < 0.001). There was no acute or delayed complication related to SLNB such as bleeding, hematoma, delayed sensory/swallowing problems, or unscheduled hospital visits. CONCLUSIONS: SLNB might be safe and effective for anesthesia in transcutaneous VFI. SLNB could be a good anesthetic option for patients with poor compliance despite the sufficient application of topical lidocaine.
ABSTRACT
AIM: This study aimed to develop a valid and reliable new intensive care unit nursing classification tool, including direct and indirect nursing activities, by measuring the nursing intensity provided to patients. BACKGROUND: Prior tools primarily examine patients' medical records or disease severity/interactions, systematically failing to reflect comorbidity risk factors. DESIGN: The Delphi technique was used to test the content validity of the Korean Patient Classification System on Nursing Intensity for Critical Care Nurses (KPCSNIC). METHODS: Data were collected from four hospitals in two provinces from 26 December 2017 to 30 January 2018. To verify construct validity, staff nurses classified 365 patients, comparing differences by medical department and type of stay. To verify interrater reliability, data collectors and the head nurses of three intensive care units classified 87 patients. RESULTS: The KPCSNIC had 8 categories, 44 nursing activities and 105 criteria. Reliability was high (r = .84). Construct validity was verified by revealing differences according to medical department and type of patient. Using total scores, four KPCSNIC groups were identified. CONCLUSION: The KPCSNIC developed in this study can support staffing for nursing intensity by providing more specific evaluation criteria. Moreover, it reflects nursing intensity, including direct and indirect nursing activities.
Subject(s)
Critical Care Nursing , Nursing Care , Nursing Staff, Hospital , Humans , Reproducibility of Results , Intensive Care Units , Critical CareABSTRACT
Depression in the elderly is an important health factor that requires intervention in the form of social support resources. The purpose of this study was to conduct a systematic review, while synthesizing available evidence on what kind of social support, such as social participation and social connection/network, is effective for depression in the elderly. We performed a quality assessment of the included studies using the revised Risk of Bias for Non-randomized Studies tool and a meta-analysis of studies published up to 14 May 2021. Of the 3449 studies, 52 were relevant to this study. The various types of social resource applications reported in these were classified into three types: social support, social participation, and social connection/network. The social support group had significantly lower depression compared to the control group (0.72 [0.65, 0.81], p < 0.00001, I2 = 92%). There was a significant decrease in depression in the social participation group compared to the control group (0.67 [0.56, 0.80], p < 0.00001, I2 = 93%) (2.77 [1.30, 5.91], p = 0.008, I2 = 97%) (0.67 [0.56, 0.80], p < 0.00001, I2 = 93%). Finally, the social connection/network group showed decreased depression compared to the control group (2.40 [1.89, 3.05], p < 0.00001, I2 = 24%) (0.83 [0.76, 0.90], p < 0.00001, I2 = 94%). The results of this systematic review confirmed the effects of various social support interventions in reducing depression among the elderly living in the community.
ABSTRACT
AIM: The aim of this study was to identify the patient and hospital characteristics related to nursing needs and nursing hours in acute hospital settings. BACKGROUND: To determine appropriate staffing levels, accumulating empirical data through direct observation and surveys reflecting the actual situation is necessary. METHODS: In this cross-sectional study, we conducted direct observations of nurses in acute care hospitals from 1 May to 31 August 2020. Twenty-six hospitals in five cities participated, and 747 nursing personnel collected 1,681 patients' data while performing nursing activities. The data of 1,605 nurses were analysed using descriptive statistics, t tests, analysis of variance and linear regression. RESULTS: Hospital size, admission day, patients' dependence level, high fall risk and disease diagnoses were variables associated with nursing needs (F = 73.49, P < .001) and nursing hours (F = 57.7, P < .001). Comparing the correlates of nursing needs and nursing hours revealed that, unlike nursing needs, nursing hours were not significantly associated with surgery and certain diagnoses. CONCLUSION: This study confirmed the variables associated with nursing needs and nursing hours in acute hospitals; based on this, determining appropriate staffing levels, which is an important step in improving inpatients' health outcomes, is necessary. IMPLICATIONS FOR NURSING MANAGEMENT: In acute hospitals, an increased number of nurse staffing should be employed based on the number of newly hospitalized patients, patients with high dependence levels and specific diagnoses, and those at high risk of falling.
Subject(s)
Nursing Staff, Hospital , Personnel Staffing and Scheduling , Cross-Sectional Studies , Hospitals , Humans , InpatientsABSTRACT
AIM: To develop a new general wards patient classification tool based on the nursing intensity level that reflects patients' clinical characteristics and indirect nursing activities. DESIGN: A cross-sectional design was adopted. This methodological study developed a patient classification system to sort general ward patients based on the intensity of their nursing needs and verified the validity and reliability of this classification system. METHODS: Thirteen experts verified the tools' content validity. Data collectors and head nurses classified 150 patients from two hospitals with four general wards and various nurse staffing levels. Inter-rater reliability was analysed. Staff nurses classified 846 patients following the Korean patient classification system on nursing intensity scores that reflected patients' clinical status. Content validity was verified based on the classification results. Using K-group cluster analysis, score ranges for four groups were identified. RESULTS: The developed tool includes 8 domains, (symptom management, infection control, nutrition and medication, personal hygiene and secretion, activity, sleep and rest, guidance in nursing/emotional support, nursing activity planning and coordination, indirect activity), 24 subdomains, 66 nursing activities and 124 criteria. Inter-rater reliability showed high agreement.
Subject(s)
Nursing Care , Patients' Rooms , Cross-Sectional Studies , Humans , Reproducibility of Results , Republic of KoreaABSTRACT
Microbial metabolites play a critical role in mucosal homeostasis by mediating physiological communication between the host and colonic microbes, whose perturbation may lead to gut inflammation. The microbial metabolite 3-indolepropionic acid (3-IPA) is one such communication mediator with potent antioxidative and anti-inflammatory activity. To apply the metabolite for the treatment of colitis, 3-IPA was coupled with acidic amino acids to yield colon-targeted 3-IPA, 3-IPA-aspartic acid (IPA-AA) and 3-IPA-glutamic acid (IPA-GA). Both conjugates were activated to 3-IPA in the cecal contents, which occurred faster for IPA-AA. Oral gavage of IPA-AA (oral IPA-AA) delivered a millimolar concentration of IPA-AA to the cecum, liberating 3-IPA. In a 2,4-dinitrobenzene sulfonic acid (DNBS)-induced rat colitis model, oral IPA-AA ameliorated rat colitis and was less effective than sulfasalazine (SSZ), a current anti-inflammatory bowel disease drug. To enhance the anticolitic activity of 3-IPA, it was azo-linked with the GPR109 agonist 5-aminonicotinic acid (5-ANA) to yield IPA-azo-ANA, expecting a mutual anticolitic action. IPA-azo-ANA (activated to 5-ANA and 2-amino-3-IPA) exhibited colon specificity in in vitro and in vivo experiments. Oral IPA-azo-ANA mitigated colonic damage and inflammation and was more effective than SSZ. These results suggest that colon-targeted 3-IPA ameliorated rat colitis and its anticolitic activity could be enhanced by codelivery of the GPR109A agonist 5-ANA.
Subject(s)
Anti-Inflammatory Agents/administration & dosage , Colitis/drug therapy , Indoles/administration & dosage , Nicotinic Acids/administration & dosage , Prodrugs/administration & dosage , Propionates/administration & dosage , Administration, Oral , Animals , Anti-Inflammatory Agents/chemistry , Colitis/chemically induced , Colitis/immunology , Colitis/pathology , Colon/drug effects , Colon/immunology , Colon/pathology , Dinitrofluorobenzene/administration & dosage , Dinitrofluorobenzene/analogs & derivatives , Dinitrofluorobenzene/toxicity , Disease Models, Animal , Drug Compounding/methods , Humans , Indoles/chemistry , Intestinal Mucosa/drug effects , Intestinal Mucosa/immunology , Intestinal Mucosa/pathology , Male , Mice , Nicotinic Acids/chemistry , Prodrugs/chemistry , Propionates/chemistry , RAW 264.7 Cells , Rats , Receptors, G-Protein-Coupled/agonists , Sulfasalazine/administration & dosageABSTRACT
An elevated level of endoplasmic reticulum (ER) stress is considered an aggravating factor for inflammatory bowel disease (IBD). To develop an ER-stress attenuator that is effective against colitis, 4-phenylbutyric acid (4-PBA), a chemical chaperone that alleviates ER stress, was conjugated with acidic amino acids to yield 4-PBA-glutamic acid (PBA-GA) and 4-PBA-aspartic acid (PBA-AA) conjugates. The PBA derivatives were converted to 4-PBA in the cecal contents, and the conversion was greater with PBA-GA than that with PBA-AA. After oral administration of PBA-GA (oral PBA-GA), up to 2.7 mM PBA was detected in the cecum, whereas 4-PBA was not detected in the blood, indicating that PBA-GA predominantly targeted the large intestine. In 2,4-dinitrobenzenesulfonic acid-induced colitis in rats, oral PBA-GA alleviated the damage and inflammation in the colon and substantially reduced the elevated levels of ER stress marker proteins in the inflamed colon. Moreover, PBA-GA was found to be as effective as the currently used anti-IBD drug, sulfasalazine. In conclusion, PBA-GA is a colon-targeted prodrug of 4-PBA and is effective against rat colitis probably via the attenuation of ER stress in the inflamed colon.
ABSTRACT
To develop a 5-aminosalicylic acid (5-ASA)-based anticolitic drug with enhanced therapeutic activity, a colon-targeted codrug constituting 5-ASA and a GPR109A agonist was designed. 5-ASA azo-coupled with nicotinic acid (ASA-azo-NA) was synthesized, and the colon specificity and anticolitic effects were evaluated. Approximately 89% of ASA-azo-NA was converted to 5-aminonicotinic acid (5-ANA) and 5-ASA after 24 h of incubation in the cecal contents. 5-ANA was identified as a GPR109A agonist (concentration that gives half-maximal response (EC50): 18 µM) in a cell-based assay. Upon oral gavage of ASA-azo-NA (oral ASA-azo-NA) and sulfasalazine (oral SSZ), a colon-targeted 5-ASA prodrug, cecal accumulation of 5-ASA was comparable, and 5-ANA was barely detectable in the blood, while it was detected up to 62.7 µM with oral 5-ANA. In parallel, oral ASA-azo-NA did not elicit an adverse skin response. In murine macrophage and human colon carcinoma cells, activation of GPR109A by 5-ANA elevated the level of the anti-inflammatory cytokine IL-10, suppressed NF-κB activation, and potentiated the inhibitory activity of 5-ASA on NF-κB. Oral ASA-azo-NA ameliorated rat colitis and was more effective than oral SSZ, which were substantially blunted following cotreatment with the GPR109A antagonist, mepenzolate. In conclusion, ASA-azo-NA is a colon-targeted anticolitic codrug with a reduced risk of skin toxicity induced by the GPR109A agonist, therapeutically surpassing a current 5-ASA-based anti-inflammatory bowel disease drug in a rat colitis model.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Colitis/drug therapy , Colon/drug effects , Receptors, G-Protein-Coupled/agonists , Animals , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Anti-Inflammatory Agents, Non-Steroidal/toxicity , Cell Line, Tumor , Chromatography, Liquid , Colitis/metabolism , Colon/pathology , Drug Delivery Systems , Humans , Inflammatory Bowel Diseases/drug therapy , Inflammatory Bowel Diseases/metabolism , Interleukin-10/metabolism , Male , Mesalamine/blood , Mesalamine/therapeutic use , Mice , NF-kappa B/metabolism , Nicotinic Acids/blood , Nicotinic Acids/therapeutic use , Rats , Rats, Sprague-Dawley , Sulfasalazine/pharmacology , Sulfasalazine/therapeutic useABSTRACT
Amisulpride (ASP), an anti-psychotic agent, is a pharmacologically equivalent to sulpiride (SP). Because SP demonstrates anti-ulcer and anti-colitic activities, ASP with an aniline moiety was azo-coupled to salicylic acid to generate 5-(aminoethanoylsulfamoyl)-N-[(1-ethylpyrrolidin-2-yl)methyl]-2-methoxybenzamide (ASP-azo-ASA), with the expectation that it would act as a colon-specific mutual prodrug against colitis. Following a 24 h incubation, approximately 80% of ASP-azo-ASA was cleaved to form ASP and 5-aminosalicylic acid (5-ASA) in the cecal contents, whereas it remained stable in the small intestinal contents. Oral gavage of ASP-azo-ASA (oral ASP-azo-ASA) delivered 5-ASA to the cecum to levels comparable with those observed for sulfasalazine (SSZ; clinical colon-specific prodrug of 5-ASA) and without detectable concentrations of ASP in the blood, indicating efficient colonic delivery. Oral ASP-azo-ASA ameliorated 2, 4-dinitrobenzenesulfonic acid hydrate (DNBS)-induced colitis in rats more effectively than oral SSZ. Additionally, oral ASP-azo-ASA lowered the levels of inflammatory mediators in the inflamed distal colon more effectively than oral SSZ. Combined treatment with 5-ASA and ASP via the rectal route more effectively reversed colonic damage and inflammation than treatment with 5-ASA or ASP alone, confirming the mutual anti-colitic actions of 5-ASA and ASP. In conclusion, ASP-azo-ASA is an orally active mutual prodrug against rat colitis with limited systemic absorption of ASP.
ABSTRACT
Sofalcone is a synthetic chalcone being used as a gastric mucosa protective agent in Japan. Sofalcone contains a 1,3-diaryl-2-propen-1-one moiety, which is a common chemical scaffold in naturally occurring chalcones. The α,ß-unsaturated carbonyl group (Michael reaction acceptor) has electrophilic properties. We investigated the biochemical mechanisms by which sofalcone activated the cytoprotective and anti-inflammatory nuclear factor-erythroid 2 (NF-E2) p45-related factor 2 (Nrf2)-heme oxygenase (HO)-1 pathway. Furthermore, we investigated whether the activation of this pathway was involved in sofalcone -mediated protective effects in an experimental colitis model. Sofalcone induced HO-1 protein expression, which was dependent on increased nuclear accumulation of Nrf2 in human colon carcinoma cells. In addition, Sofalcone reacted with nucleophilic thiol compounds to form Michael adducts. A reduced form of sofalcone (SFCR) in which the Michael reaction acceptor was deactivated, did not exert biological or chemical activity. Biotin-tagged sofalcone bound to Kelch-like ECH-associated protein 1 (KEAP1), a cytosolic repressor of Nrf2. This binding was prevented by pretreatment with sofalcone and a thiol compound but not with SFCR. Furthermore, sofalcone treatment induced dissociation of the Nrf2-KEAP1 complex. Rectal administration of sofalcone alleviated colon damage and inflammation and increased colon nuclear accumulation of Nrf2 and HO-1 levels in a dinitrobenzene sulfonic acid-induced rat colitis model. The protective effects of sofalcone against colon damage and inflammation were significantly inhibited by co-administration of an HO-1 inhibitor. In conclusion, sofalcone activated the Nrf2-HO-1 pathway by covalently binding to KEAP1 via Michael addition, and may confer anti-colitic effects by inducing Nrf2 activation.
Subject(s)
Chalcones/metabolism , Chalcones/pharmacology , Colitis/drug therapy , Gastrointestinal Tract/drug effects , Kelch-Like ECH-Associated Protein 1/metabolism , NF-E2-Related Factor 2/metabolism , Animals , Chalcones/therapeutic use , Colitis/metabolism , Colitis/pathology , Gastrointestinal Tract/metabolism , Gastrointestinal Tract/pathology , Male , Protein Binding , Rats , Rats, Sprague-DawleyABSTRACT
We investigated if the therapeutic switching of sofalcone (SFC), a gastroprotective agent, to an anticolitic agent is feasible using colon-targeted drug delivery. SFC can activate the anti-inflammatory nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-hemeoxygenase-1 (HO-1) pathway in human colon epithelial cells and murine macrophages. For the efficient treatment of colitis, SFC was coupled with acidic amino acids to yield SFC-aspartic acid (SFC-AA) and SFC-glutamic acid, and their colon targetability and therapeutic effects were assessed as an anticolitic agent in a 2,4-dinitrobenezenesulfonic acid-induced rat colitis model. The SFC derivatives were decoupled up to 72% in the cecal contents but remained stable in the small intestinal contents. Oral gavage of SFC-AA (oral SFC-AA, equivalent to 1.67 mg/kg of SFC) delivered SFC (maximal cecal concentration: 57.36 µM) to the cecum, while no SFC was detected with oral gavage of SFC (oral SFC, 1.67 mg/kg). Moreover, oral SFC-AA (equivalent to 10 mg/kg of SFC) did not afford detectable concentration of SFC in the blood but detected up to 4.64 µM with oral SFC (10 mg/kg), indicating efficient colonic delivery and limited systemic absorption of SFC upon oral SFC-AA. Oral SFC-AA ameliorated colonic damage and inflammation in rat colitis with elevating colonic levels of HO-1 and nuclear Nrf2 protein, and the anticolitic effects of SFC-AA were significantly undermined by an HO-1 inhibitor. At an equivalent dose of SFC, oral SFC-AA but not oral SFC increased colonic HO-1 and nuclear Nrf2 levels, and oral SFC-AA was more effective than oral SFC in treating rat colitis. Moreover, oral SFC-AA was as effective against colitis as oral sulfasalazine being used for the treatment of inflammatory bowel disease. In conclusion, colon-targeted delivery of SFC facilitated the therapeutic switching of the drug to an anticolitic drug via Nrf2 activation.
Subject(s)
Anti-Ulcer Agents/therapeutic use , Chalcones/therapeutic use , Colitis/drug therapy , Drug Delivery Systems/methods , NF-E2-Related Factor 2/metabolism , Protective Agents/therapeutic use , Administration, Oral , Amino Acids, Acidic/administration & dosage , Amino Acids, Acidic/chemistry , Animals , Anti-Ulcer Agents/administration & dosage , Anti-Ulcer Agents/chemistry , Chalcones/administration & dosage , Chalcones/chemistry , Colitis/chemically induced , Dinitrofluorobenzene/analogs & derivatives , Dinitrofluorobenzene/pharmacology , Disease Models, Animal , Epithelial Cells/metabolism , Gene Knockdown Techniques , HCT116 Cells , Heme Oxygenase-1/metabolism , Humans , Male , Mice , NF-E2-Related Factor 2/genetics , Protective Agents/administration & dosage , Protective Agents/chemistry , RAW 264.7 Cells , Rats , Rats, Sprague-Dawley , Signal Transduction/drug effects , Sulfasalazine/administration & dosage , Sulfasalazine/therapeutic use , Transfection , Treatment OutcomeABSTRACT
We report a simultaneous imaging method of the temperature and the magnetic field distributions based on the magneto optical indicator microscopy. The present method utilizes an optical indicator composed of a bismuth-substituted yttrium iron garnet thin film, and visualizes the magnetic field and temperature distributions through the magneto-optical effect and the temperature dependent optical absorption of the garnet thin film. By using a printed circuit board that carries an electric current as a device under test, we showed that the present method can visualize the magnetic field and temperature distribution simultaneously with a comparable temperature sensitivity (0.2 K) to that of existing conventional thermal imagers. The present technique provides a practical way to get a high resolution magnetic and thermal image at the same time, which is valuable in investigating how thermal variation results in a change of the operation state of a micrometer sized electronic device or material.
ABSTRACT
Adaptive electronics, which are often referred to as memristive systems as they often rely on a memristor (memory resistor), are an emerging technology inspired by adaptive biological systems. Dissipative systems may provide a proper platform to implement an adaptive system due to its inherent adaptive property that parameters describing the system are optimized to maximize the entropy production for a given environment. Here, we report that a non-volatile and reversible adaptive microwave impedance memory device can be realized through the adaptive property of the dissipative structure of the driven ferromagnetic system. Like the memristive device, the microwave impedance of the device is modulated as a function of excitation microwave passing through the device. This kind of new device may not only helpful to implement adaptive information processing technologies, but also may be useful to investigate and understand the underlying mechanism of spontaneous formation of complex and ordered structures.
ABSTRACT
A high resolution imaging of the temperature and microwave near field can be a powerful tool for the non-destructive testing of materials and devices. However, it is presently a very challenging issue due to the lack of a practical measurement pathway. In this work, we propose and demonstrate experimentally a practical method resolving the issue by using a conventional CCD-based optical indicator microscope system. The present method utilizes the heat caused by an interaction between the material and an electromagnetic wave, and visualizes the heat source distribution from the measured photoelastic images. By using a slide glass coated by a metal thin film as the indicator, we obtain optically resolved temperature, electric, and magnetic microwave near field images selectively with a comparable sensitivity, response time, and bandwidth of existing methods. The present method provides a practical way to characterize the thermal and electromagnetic properties of materials and devices under various environments.
ABSTRACT
Animated pedagogical agents are lifelike virtual characters designed to augment learning. A review of developmental psychology literature led to the hypothesis that the temporal contingency of such agents would promote human learning. We developed a Pedagogical Agent with Gaze Interaction (PAGI), an experimental animated pedagogical agent that engages in gaze interaction with students. In this study, university students learned words of a foreign language, with temporally contingent PAGI (live group) or recorded version of PAGI (recorded group), which played pre-recorded sequences from live sessions. The result revealed that students in the live group scored considerably better than those in the recorded group. The finding indicates that incorporating temporal contingency of gaze interaction from a pedagogical agent has positive effect on learning.
ABSTRACT
We study the opto-electrical properties of Natronomonas pharaonis sensory rhodopsin II (NpSRII) by using a near-field microwave microprobe (NFMM) under external light illumination. To investigate the possibility of application of NFMM to biological macromolecules, we used time dependent properties of NPSRII before/after light activation which has three distinct states - ground-state, M-state, and O-state. The diagnostic ability of NFMM is demonstrated by measuring the microwave reflection coefficient (S(11)) spectrum of NpSRII under steady-state illumination in the wavelength range of 350-650 nm. Moreover, we present microwave reflection coefficient S(11) spectra in the same wavelength range for two fast-photocycling rhodopsins: green light-absorbing proteorhodopsin (GPR) and Gloeobacter rhodopsin (GR). In addition the frequency sweep shift can be detected completely even for tiny amounts of sample (â¼10(-3) OD of rhodopsin). Based on these results NFMM shows both very high sensitivity for detecting conformational changes and produces a good time-resolved spectrum.