Efficacy of very-low-dose oral food challenge in children with severe hen egg allergy: A retrospective, single-center case series.

BACKGROUND: To avoid complete elimination of hen eggs (HE) from diet, we introduced a very-low-dose (VLD) oral food challenge (OFC) in patients with severe HE allergy in 2019. Herein, we investigated the efficacy of VLD HE OFC for achieving the full dose OFC. METHODS: Patients with an overt allergic reaction to LD (1/32 HE [≤100 mg]) or less, egg white (EW) protein within 6 months were included. In the VLD group, patients not achieving full-dose OFC (1/2 HE: 1600 mg EW protein) within 2 years were excluded. We retrospectively compared the rate of passing a full-dose OFC between patients who underwent a LD OFC before 2019 (LD group) and those who underwent a VLD OFC (1/100 HE: 32 mg EW protein) after 2019 (VLD group). The period for passing the full-dose OFC was evaluated using Kaplan-Meier survival analysis. RESULTS: We enrolled 411 and 111 patients in the LD and VLD groups, respectively. The median age at OFC initiation was 2.2 [1.5-3.6] and 2.1 [1.4-3.2] years in the LD and VLD groups, respectively. EW- and ovomucoid-specific IgE levels were 38.3 (12.5-72.9) and 21.0 (8.3-46.2) kUA/L in the LD group and 49.8 [18.8-83.9] and 32.1 [15.6-67.8] kUA/L in the VLD group, respectively. Over 4 years, the LD and VLD groups passed the full-dose OFC at rates of 70 and 95%, respectively, with significant differences (log-rank test, P < 0.001). CONCLUSIONS: VLD HE OFC may contribute to passing a full-dose OFC in patients with severe HE allergies.

Phonon modes controlled by primary chemical structure of partially fluorinated dimyristoylphosphatidylcholine (DMPC) revealed by multiple-angle incidence resolution spectrometry (MAIRS).

Partially fluorinated dimyristoylphosphatidylcholines (DMPCs) involving double alkyl chains are employed to control the phonon generation in thin films, which is examined by infrared (IR) spectroscopy coupled with multiple-angle incidence resolution spectrometry (MAIRS). technique. Compounds having perfluoroalkyl (Rf) chains are known to exhibit phonon bands in IR spectra because of the strong dipole-dipole interactions. Since the phonon bands of an organic matter have a similar shape to the normal absorption bands, however, recognition of the phonon modes is difficult and confusing for IR spectroscopists. Here, we show that MAIRS works out for finding phonon modes in monolayers: the Berreman shift is readily captured by the MAIRS in-plane and out-of-plane (OP) spectra. By measuring the longitudinal-optic (LO) energy-loss function spectrum of a bulk sample, the degree of molecular aggregation in the monolayer is also revealed by comparing the OP spectrum of the monolayer to the LO one. In addition, partially fluorinated DMPC compounds having both hydrocarbon and Rf chains are prepared, and they are used to obstruct the self-aggregation of the Rf groups in the film. As a result, the phonon characteristics are mostly lost in the MAIRS spectra as expected.

Suppressed pediatric asthma hospitalizations during the COVID-19 pandemic in Japan, from a national survey.

BACKGROUND: Acute asthma exacerbation in children is often caused by respiratory infections. In this study, a coordinated national surveillance system for acute asthma hospitalizations and causative respiratory infections was established. We herein report recent trends in pediatric acute asthma hospitalizations since the COVID-19 pandemic in Japan. METHODS: Thirty-three sentinel hospitals in Japan registered all of their hospitalized pediatric asthma patients and their causal pathogens. The changes in acute asthma hospitalization in children before and after the onset of the COVID-19 pandemic and whether or not COVID-19 caused acute asthma exacerbation were investigated. RESULTS: From fiscal years 2010-2019, the median number of acute asthma hospitalizations per year was 3524 (2462-4570), but in fiscal years 2020, 2021, and 2022, the numbers were 820, 1,001, and 1,026, respectively (the fiscal year in Japan is April to March). This decrease was observed in all age groups with the exception of the 3- to 6-year group. SARS-CoV-2 was evaluated in 2094 patients from fiscal years 2020-2022, but the first positive case was not detected until February 2022. Since then, only 36 of them have been identified with SARS-CoV-2, none of which required mechanical ventilation. Influenza, RS virus, and human metapneumovirus infections also decreased in FY 2020. In contrast, 24% of patients had not been receiving long-term control medications before admission despite the severity of bronchial asthma. CONCLUSION: SARS-CoV-2 was hardly detected in children with acute asthma hospitalization during the COVID-19 pandemic. This result indicated that SARS-CoV-2 did not induce acute asthma exacerbation in children. Rather, infection control measures implemented against the pandemic may have consequently reduced other respiratory virus infections and thus acute asthma hospitalizations during this period. However, the fact that many hospitalized patients have not been receiving appropriate long-term control medications is a major problem that should be addressed.

Thermodynamic study on hydrated bilayers of ether-linked phosphatidylcholines with terminal perfluorobutyl group.

Novel terminally perfluorobutyl group-containing ether-linked phosphatidylcholines with different alkyl chain lengths (di-O-F4-Cn-PCs, n = 14,16 and 18) were developed as possible materials for stable liposomes aiming at applications of structural and functional analyses of membrane proteins. Differential scanning calorimetric investigations of the thermotropic transition of hydrated di-O-F4-Cn-PC bilayers demonstrated that the transition temperature of every di-O-F4-Cn-PC decreases by ~20 °C compared to their corresponding non-fluorinated PCs, di-O-Cn-PCs. With the elongation of the hydrophobic chain, on the other hand, the transition enthalpy (ΔH) and entropy (ΔS) increased in a linear manner. Comparison of ΔH and ΔS values against the net hydrocarbon chain length between di-O-F4-Cn-PCs and di-O-Cn-PCs strongly suggests that in the thermotropic transition of the di-O-F4-Cn-PC membrane, the perfluorobutyl segments undergo very limited structural changes; therefore, the hydrocarbon segments are mainly responsible for the phase transition.

[BULLYING IN JAPANESE CHILDREN AND ADOLESCENTS WITH FOOD ALLERGIES].

OBJECTIVE: To elucidate the prevailing circumstances of victimization, including bullying, faced by children afflicted with food allergies in Japan. METHODS: From July to August 2021, we executed a web-based questionnaire survey targeting children with food allergies enrolled in the fourth grade or higher, who sought medical attention at the Department of Pediatrics in Showa University Hospital or were affiliated with three allergy-focused patient associations. The survey aimed to ascertain whether these children had encountered instances of bullying, the nature of the bullying incidents, and whether such acts of bullying triggered allergic symptoms. RESULTS: A total of sixty-six children with food allergies participated in the survey. Among them, forty-five (68%) were male, thirty-three (50%) were attending elementary school, and thirty-five (53%) reported experiencing some form of victimization throughout their lives. Specifically, fourteen (21%) had been subjected to bullying due to their food allergy, with two children being coerced into consuming allergens and one child experiencing symptoms induced by allergen-based bullying. CONCLUSION: It is evident that a significant number of children with food allergies face bullying. Therefore, it is imperative for healthcare providers and parents to acknowledge the inherent risk of bullying as an integral aspect of caring for children with food allergies. Prompt measures should be taken, such as educating both teachers and non-allergic children about this risk.

[INVESTIGATION OF THE IMPACT OF ALLERGIC DISEASE ON CHILDREN'S SARS-CoV-2 VACCINATION DECISIONS].

Background, Objectives: The factors associated with parents' decisions to vaccinate their children with SARS-CoV-2 vaccine and the impact of the coexistence of allergic diseases in their children are unclear. METHODS: A cross-sectional survey was conducted among parents of patients aged 15 years or younger who visited our pediatric allergy outpatient clinic and three partner pediatric clinics between April and May 2021. Survey items included presence or absence of other allergic diseases, and SARS-CoV-2 vaccination preferences and reasons. RESULTS: 646 responses were received, with 568 valid responses (88%). Thirty-eight respondents (6.7%) did not want their children to receive SARS-CoV-2 vaccine. Factors that led parents to reject the SARS-CoV-2 vaccine for their children were the coexistence of food allergies and a low evaluation of the expectations of the safety and preventive effect of the SARS-CoV-2 vaccine. The top reasons for not wanting to vaccinate were related to concerns about side effects to the vaccine. CONCLUSION: In order for parents to make correct decisions regarding SARS-CoV-2 vaccination of their children, it is necessary to create an environment in which up-to-date and correct information is available to avoid excessive anxiety. More care is needed, especially if the child has food allergies.

Relationship between the diagnosis of food protein-induced enterocolitis syndrome and postemetic procalcitonin levels.

Background: There are no reports on the relationship between food protein-induced enterocolitis syndrome (FPIES) diagnosis and procalcitonin levels. Objective: Our study sought to demonstrate a correlation between the presence or absence and severity of FPIES symptoms and postemetic procalcitonin levels. Methods: The subjects were 53 patients with FPIES (44 with hen's egg allergy, 4 with milk allergy, 4 with wheat allergy, and 3 with soy allergy), who collectively underwent a total of 75 oral food challenges (OFCs). Procalcitonin levels at 5 hours after antigen ingestion were compared between patients with a positive OFC result and those with a negative OFC result and between patients who experienced mild or moderate events and those who experienced severe events. Results: At 5 hours after ingestion of the causative food, the median procalcitonin levels in patients with a negative OFC result, patients who experienced a mild or moderate event, and patients who experienced a severe event were 0.02, 0.03, and 0.16 ng/mL, respectively. The procalcitonin level was significantly higher in the groups with a positive OFC result than in the groups with a negative OFC result (P < .001), and it was significantly higher in those who experienced severe events than in those who experienced mild or moderate events (P = .012). Conclusion: Measurement of procalcitonin levels has the potential to provide a quantitative and objective assessment of FPIES diagnosis and severity.

Euryhaline fish larvae ingest more microplastic particles in seawater than in freshwater.

Microplastic (MP) pollution is a major concern in aquatic environments. Many studies have detected MPs in fishes; however, little is known about differences of microplastic uptake by fish in freshwater (FW) and those in seawater (SW), although physiological conditions of fish differ significantly in the two media. In this study, we exposed larvae (21 days post-hatching) of Oryzias javanicus (euryhaline SW) and Oryzias latipes (euryhaline FW), to 1-µm polystyrene microspheres in SW and FW for 1, 3, or 7 days, after which, microscopic observation was conducted. MPs were detected in the gastrointestinal tracts in both FW and SW groups, and MP numbers were higher in the SW group in both species. Vertical distribution of MPs in the water, and body sizes of both species exhibited no significant difference between SW and FW. Detection of water containing a fluorescent dye revealed that O. javanicus larvae swallowed more water in SW than in FW, as has also been reported for O. latipes. Therefore, MPs are thought to be ingested with water for osmoregulation. These results imply that SW fish ingest more MPs than FW fish when exposed to the same concentration of MPs.

Mutualistic Interactions between Dinoflagellates and Pigmented Bacteria Mitigate Environmental Stress.

Scleractinian corals form symbiotic relationships with a variety of microorganisms, including endosymbiotic dinoflagellates of the family Symbiodiniaceae, and with bacteria, which are collectively termed coral holobionts. Interactions between hosts and their symbionts are critical to the physiological status of corals. Coral-microorganism interactions have been studied extensively, but dinoflagellate-bacterial interactions remain largely unexplored. Here, we developed a microbiome manipulation method employing KAS-antibiotic treatment (kanamycin, ampicillin, and streptomycin) to favor pigmented bacteria residing on cultured Cladocopium and Durusdinium, major endosymbionts of corals, and isolated several carotenoid-producing bacteria from cell surfaces of the microalgae. Following KAS-antibiotic treatment of Cladocopium sp. strain NIES-4077, pigmented bacteria increased 8-fold based on colony-forming assays from the parental strain, and 100% of bacterial sequences retrieved through 16S rRNA amplicon sequencing were affiliated with the genus Maribacter. Microbiome manipulation enabled host microalgae to maintain higher maximum quantum yield of photosystem II (variable fluorescence divided by maximum fluorescence [Fv/Fm]) under light-stress conditions, compared to the parental strain. Furthermore, by combining culture-dependent and -independent techniques, we demonstrated that species of the family Symbiodiniaceae and pigmented bacteria form strong interactions. Dinoflagellates protected bacteria from antibiotics, while pigmented bacteria protected microalgal cells from light stress via carotenoid production. Here, we describe for the first time a symbiotic relationship in which dinoflagellates and bacteria mutually reduce environmental stress. Investigations of microalgal-bacterial interactions further document bacterial contributions to coral holobionts and may facilitate development of novel techniques for microbiome-mediated coral reef conservation. IMPORTANCE Coral reefs cover less than 0.1% of the ocean floor, but about 25% of all marine species depend on coral reefs at some point in their life cycles. However, rising ocean temperatures associated with global climate change are a serious threat to coral reefs, causing dysfunction of the photosynthetic apparatus of endosymbiotic microalgae of corals, and overproducing reactive oxygen species harmful to corals. We manipulated the microbiome using an antibiotic treatment to favor pigmented bacteria, enabling their symbiotic microalgal partners to maintain higher photosynthetic function under insolation stress. Furthermore, we investigated mechanisms underlying microalgal-bacterial interactions, describing for the first time a symbiotic relationship in which the two symbionts mutually reduce environmental stress. Our findings extend current insights about microalgal-bacterial interactions, enabling better understanding of bacterial contributions to coral holobionts under stressful conditions and offering hope of reducing the adverse impacts of global warming on coral reefs.

Rapid and Highly Sensitive Method for Evaluating Surface Coatings against an Enveloped RNA Virus.

The COVID-19 pandemic has increased public health vigilance worldwide. The coronavirus (SARS-CoV-2) can spread via aerosols, and droplet-borne viruses remain viable on nonliving surfaces for long duration. Hence, effective antiviral coatings are highly useful in eliminating viral persistence on nonliving surfaces. Although innovative antiviral coatings have been designed, conventional procedures for antiviral assays are generally laborious, time-consuming, and have a high limit of detection. In the present study, we report a rapid and highly sensitive method for evaluating antiviral coatings by measuring the luciferase activity derived from recombinant Sendai virus (SeV). The physicochemical characteristics of SeV, which has a single-stranded RNA genome encapsulated within a lipid envelope, allow us to exploit it as an indicator of the physicochemical potential of coating materials against enveloped RNA viruses in general. We demonstrate that SeV-based assay systems allow for the rapid and quantitative evaluation of the surface coatings composed of iodine solubilized in polyvinyl acetate. Additionally, we have investigated the effect of mucins, the dominant protein component of saliva, on the antiviral activity of surface coatings. The presence of mucins in the SeV suspension considerably rescues luciferase activity at the viral-surface interface, presumably due to mucin-mediated viral protection. Our findings provide insights into a procedure capable of the rapid evaluation and optimization of surface coatings, and suggest an important role of the mucin in the valid evaluation of antiviral agents.

Establishment of cytochrome P450 1a gene-knockout Javanese medaka, Oryzias javanicus, which distinguishes toxicity modes of the polycyclic aromatic hydrocarbons, pyrene and phenanthrene.

Cytochrome P450 1a (Cyp1a) is an important enzyme for metabolism of organic pollutants. To understand its reaction to polycyclic aromatic hydrocarbons (PAHs), we knocked out this gene in a marine model fish, Javanese medaka, Oryzias javanicus, using the CRISPR/Cas 9 system. A homozygous mutant (KO) strain with a four-base deletion was established using an environmental DNA (eDNA)-based genotyping technique. Subsequently, KO, heterozygous mutant (HT), and wild-type (WT) fish were exposed to model pollutants, pyrene and phenanthrene, and survivorship and swimming behavior were analyzed. Compared to WT, KO fish were more sensitive to pyrene, suggesting that Cyp1a transforms pyrene into less toxic metabolites. Conversely, WT fish were sensitive to phenanthrene, suggesting that metabolites transformed by Cyp1a are more toxic than the original compound. HT fish showed intermediate results. Thus, comparative use of KO and WT fish can distinguish modes of pollutant toxicity, providing a deeper understanding of fish catabolism of environmental pollutants.

High-Selectivity imaging of the closed fatigue crack due to thermal environment using surface-acoustic-wave phased array (SAW PA).

Crack closure can cause the underestimation or misdetection of fatigue cracks in ultrasonic testing (UT). Fatigue-crack closure due to an environmental factor, i.e., high temperature, was found in eddy current testing (ECT), which is used to inspect the vicinity of surfaces. However, its effect and countermeasures have yet to be examined in UT. In this study, we examined the fatigue-crack closure induced by heat processing using a surface-acoustic-wave phased array (SAW PA). SAW PA is a phased-array imaging method using Rayleigh waves, which can sensitively visualize defects in the vicinity of surfaces. As a result, the intensity of crack responses visualized by SAW PA markedly decreased after the heat processing of a fatigue-crack specimen. Furthermore, we demonstrated that the combination of SAW PA with a crack opening method, global preheating and local cooling (GPLC), and a load difference phased array (LDPA) is useful for the high-selectivity imaging of closed fatigue cracks. We also discussed a possible mechanism of the fatigue-crack closure induced by heat processing.

Specific Detection of Coral-Associated Ruegeria, a Potential Probiotic Bacterium, in Corals and Subtropical Seawater.

Coral microbial flora has been attracting attention because of their potential to protect corals from environmental stresses or pathogens. Although coral-associated bacteria are considered to be acquired from seawater, little is known about the relationships between microbial composition in corals and its surrounding seawater. Here, we tested several methods to identify coral-associated bacteria in coral and its surrounding seawater to detect specific types of Ruegeria species, some of which exhibit growth inhibition activities against the coral pathogen Vibrio coralliilyticus. We first isolated coral-associated bacteria from the reef-building coral Galaxea fascicularis collected at Sesoko Island, Okinawa, Japan, via random colony picking, which showed the existence of varieties of bacteria including Ruegeria species. Using newly constructed primers for colony PCR, several Ruegeria species were successfully isolated from G. fascicularis and seawater. We further investigated the seawater microbiome in association with the distance from coral reefs. By seasonal sampling, it was suggested that the seawater microbiome is more affected by seasonality than the distance from coral reefs. These methods and results may contribute to investigating and understanding the relationships between the presence of corals and microbial diversity in seawater, in addition to the efficient isolation of specific bacterial species from coral or its surrounding seawater.

Comparison of functionality and structural stability of bacteriorhodopsin reconstituted in partially fluorinated dimyristoylphosphatidylcholine liposomes with different perfluoroalkyl chain lengths.

Amphiphilic molecules with one or more perfluoroalkyl groups (Rf, CnF2n+1), which show peculiar interfacial properties, are attracting much attention in membrane protein science. We recently have developed a partially fluorinated dimyristoylphosphatidylcholine (DMPC) with a perfluorobutyl group in the hydrophobic chain terminal (F4-DMPC) and demonstrated that F4-DMPC is a promising material for incorporating membrane proteins. Moreover, we have found out that membrane properties of a series of partially fluorinated DMPCs with different Rf chain lengths (Fn-DMPCs) vary in a significant Rf chain length-dependent manner. In the present study, structural and functional properties of a membrane protein bacteriorhodopsin (bR) in the Fn-DMPC (n = 4, 6, and 8) membranes (bR/Fn-DMPC) are investigated using several physicochemical techniques. Regardless of the Rf chain lengths, bR/Fn-DMPCs retain native-like structural and functional properties at 30 °C, unlike bR molecules in DMPC vesicles. In particular, bR/F6-DMPC, which is in the fluid phase at 30 °C, shows flash-induced transient absorption changes very similar to the native purple membrane (PM) and very high thermal stability of bR trimers comparable to the PM. Structural and functional properties of bR/Fn-DMPCs are discussed compared to the PM and bR/DMPC.

Divalent metal transporter-related protein restricts animals to marine habitats.

Utilization and regulation of metals from seawater by marine organisms are important physiological processes. To better understand metal regulation, we searched the crown-of-thorns starfish genome for the divalent metal transporter (DMT) gene, a membrane protein responsible for uptake of divalent cations. We found two DMT-like sequences. One is an ortholog of vertebrate DMT, but the other is an unknown protein, which we named DMT-related protein (DMTRP). Functional analysis using a yeast expression system demonstrated that DMT transports various metals, like known DMTs, but DMTRP does not. In contrast, DMTRP reduced the intracellular concentration of some metals, especially zinc, suggesting its involvement in negative regulation of metal uptake. Phylogenetic distribution of the DMTRP gene in various metazoans, including sponges, protostomes, and deuterostomes, indicates that it originated early in metazoan evolution. However, the DMTRP gene is only retained in marine species, and its loss seems to have occurred independently in ecdysozoan and vertebrate lineages from which major freshwater and land animals appeared. DMTRP may be an evolutionary and ecological limitation, restricting organisms that possess it to marine habitats, whereas its loss may have allowed other organisms to invade freshwater and terrestrial habitats.

Membrane properties of amacrocyclic tetraether bisphosphatidylcholine lipid: Effect of a single membrane-spanning polymethylene cross-linkage between two head groups of ditetradecylphosphatidylcholine membrane.

The plasma membranes of archaea are abundant in macrocyclic tetraether lipids that contain a single or double long transmembrane hydrocarbon chains connecting the two glycerol backbones at both ends. In this study, a novel amacrocyclic bisphosphatidylcholine lipid bearing a single membrane-spanning octacosamethylene chain, 1,1'-O-octacosamethylene-2,2'-di-O-tetradecyl-bis-(sn-glycero)-3,3'-diphosphocholine (AC-(di-O-C14PC)2), was synthesized to elucidate effects of the interlayer cross-linkage on membrane properties based on comparison with its corresponding diether phosphatidylcholine, 1,2-di-O-tetradecyl-sn-glycero-3-phosphocholine (DTPC), that forms bilayer membrane. Several physicochemical techniques demonstrated that while AC-(di-O-C14PC)2 monolayer, which adopts a particularly high-ordered structure in the gel phase, shows remarkably high thermotropic transition temperature compared to DTPC bilayer, the fluidity of both phospholipids above the transition temperature is comparable. Nonetheless, the fluorescent dye leakage from inside the AC-(di-O-C14PC)2 vesicles in the fluid phase is highly suppressed. The origin of the membrane properties characteristic of AC-(di-O-C14PC)2 monolayer is discussed in terms of the single long transmembrane hydrophobic linkage and the diffusional motion of the lipid molecules.

Membrane properties of ether-type phosphatidylcholine bearing partially fluorinated C18-monoacetylenic chains and their applicability to membrane protein reconstitution matrices.

To examine the applicability of fluorinated membrane-forming phospholipids to reconstitution matrices for functional membrane proteins, the membrane properties of a synthetic ether-type phosphatidylcholine (PC) bearing partially fluorinated C18-monoacetylenic (9-octadecynyl) chains, DF8CCH8PC, were compared with those of its non-fluorinated counterpart, DH8CCH8PC. Light-harvesting complex 2 (LH2) and the light-harvesting 1‒reaction center core complex (LH1-RC) isolated from purple photosynthetic bacteria were employed as probe membrane proteins to evaluate the extent to which their reconstitution into DF8CCH8PC membranes could proceed. DF8CCH8PC formed more expanded and more stable fluid monolayers than DH8CCH8PC at the air-water interface at 25 °C; the former PC molecule occupied an area of ca. 0.70 nm2 at a collapse pressure, πc, of 52 mN/m, while the latter occupied an area of ca. 0.55 nm2 at a πc of 45 mN/m. In contrast, the molecular motion detected using fluorescent probes was much more restricted in DF8CCH8PC bilayers than in DH8CCH8PC ones. Although the reconstitution efficiencies of both LH2 and LH1-RC into DF8CCH8PC bilayers were lower than those into DH8CCH8PC bilayers, the membrane proteins incorporated into DF8CCH8PC bilayers showed increased thermostability. The increased thermostability of these proteins in fluorinated PC membranes might be due to the restricted molecular motion in the hydrophobic chains. The results of this study suggest that partially fluorinated PCs can be useful materials for the construction of lipid‒functional membrane protein assemblies including large membrane protein complexes, such as LH1-RC, for biotechnological applications.

Stepwise construction of dynamic microscale concentration gradients around hydrogel-encapsulated cells in a microfluidic perfusion culture device.

Inside living organisms, concentration gradients dynamically change over time as biological processes progress. Therefore, methods to construct dynamic microscale concentration gradients in a spatially controlled manner are needed to provide more realistic research environments. Here, we report a novel method for the construction of dynamic microscale concentration gradients in a stepwise manner around cells in micropatterned hydrogel. In our method, cells are encapsulated in a photodegradable hydrogel formed inside a microfluidic perfusion culture device, and perfusion microchannels are then fabricated in the hydrogel by micropatterned photodegradation. The cells in the micropatterned hydrogel can then be cultured by perfusing culture medium through the fabricated microchannels. By using this method, we demonstrate the simultaneous construction of two dynamic concentration gradients, which allowed us to expose the cells encapsulated in the hydrogel to a dynamic microenvironment.

Evaluation of detectability of differential type probe using directional eddy current for fibre waviness in CFRP.

This paper describes the detectability of eddy current testing (ECT) using directional eddy current for detection of in-plane fibre waviness in unidirectional carbon fibre reinforced plastic (CFRP) laminate. Three different types of probes, such as circular driving, symmetrical driving and uniform driving probe, were proposed, and the waviness angle was extracted from the contour map of the ECT signal by applying a Canny filter and a Hough transform. By comparing both the waviness angle estimated by ECT and that obtained by an X-ray CT image, the standard deviation (precision) and root mean square error (accuracy) were evaluated to discuss the detectability of these probes. The directional uniform driving probe shows the best detectability and can detect fibre waviness with a waviness angle of more than 2° in unidirectional CFRP. The probe shows a root mean square error of 1.90° and a standard deviation of 4.49° between the actual waviness angle and the angle estimated by ECT. This article is part of the theme issue 'Advanced electromagnetic non-destructive evaluation and smart monitoring'.