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This study is concerned with an eigenvalue problem of a vibro-acoustic coupled system. In the conventional modal coupling method, the particle velocity normal to the surface of a panel is always calculated as zero, and the wave motion in the cavity cannot be directly treated. To overcome the problem, this study presents a novel formulation for a coupled system that expresses the correct boundary condition at the coupling plane and the wave motion in the cavity. First, a transfer matrix is introduced which can describe the characteristics of the sound field based on the wave dynamics. It is then clarified that if the panel vibration is regarded as the input to the cavity, the boundary condition of the sound field at the coupling plane should be a rigid wall. This is followed by the formulation of the eigenvalue problem of a vibro-acoustic coupled system. Finally, some numerical simulations are conducted, thereby clarifying the principles of the shift of natural frequencies and mode shapes, the accuracy of boundary condition at a coupling plane, and the orthogonality of coupled modes.

Approximately half of genetic disease-associated mutations cause aberrant splicing. However, a widely applicable therapeutic strategy to splicing diseases is yet to be developed. Here, we analyze the mechanism whereby IKBKAP-familial dysautonomia (FD) exon 20 inclusion is specifically promoted by a small molecule splice modulator, RECTAS, even though IKBKAP-FD exon 20 has a suboptimal 5' splice site due to the IVS20 + 6 T C mutation. Knockdown experiments reveal that exon 20 inclusion is suppressed in the absence of serine/arginine-rich splicing factor 6 (SRSF6) binding to an intronic splicing enhancer in intron 20. We show that RECTAS directly interacts with CDC-like kinases (CLKs) and enhances SRSF6 phosphorylation. Consistently, exon 20 splicing is bidirectionally manipulated by targeting cellular CLK activity with RECTAS versus CLK inhibitors. The therapeutic potential of RECTAS is validated in multiple FD disease models. Our study indicates that small synthetic molecules affecting phosphorylation state of SRSFs is available as a new therapeutic modality for mechanism-oriented precision medicine of splicing diseases.

Ultrafast phenomena in gold nanotriangles (AuNTs) were investigated using a transient electron energy-loss spectroscopy (TEELS) technique under irradiation from a 150-fs pulse laser with a wavelength of 780 nm. This investigation was conducted using a time-resolved transmission electron microscopy method that was developed to measure the dynamics of nanomaterials. Enhancement of the intensity and energy-width broadening of the energy loss were observed at the EEL peaks associated with surface and bulk plasmons on the AuNTs. The TEELS measurement revealed two decay processes of 7.8 ps and longer than 100 ps that compensate for relaxation times of excited surface plasmons using transient absorption spectroscopy. The results show that the bulk and surface plasmons have the same time evolution, i.e., that the excited electrons on the surface and in the bulk have the same relaxation processes in both electron–phonon and phonon–phonon interactions. The time evolution of electronic and lattice temperatures was also estimated based on the measured relaxation time using a two-temperature model, which revealed the volume expansion of the AuNTs and clarified the energy shifts of plasmons. Details of excited electrons in nanoparticles investigated via plasmon energy loss are expected to facilitate improvement in the performance for energy harvesting of photons in nanostructure-controlled materials.

Approximately half of genetic disease-associated mutations cause aberrant splicing. However, a widely applicable therapeutic strategy to splicing diseases is yet to be developed. Here, we analyze the mechanism whereby IKBKAP-familial dysautonomia (FD) exon 20 inclusion is specifically promoted by a small molecule splice modulator, RECTAS, even though IKBKAP-FD exon 20 has a suboptimal 5′ splice site due to the IVS20 + 6 T > C mutation. Knockdown experiments reveal that exon 20 inclusion is suppressed in the absence of serine/arginine-rich splicing factor 6 (SRSF6) binding to an intronic splicing enhancer in intron 20. We show that RECTAS directly interacts with CDC-like kinases (CLKs) and enhances SRSF6 phosphorylation. Consistently, exon 20 splicing is bidirectionally manipulated by targeting cellular CLK activity with RECTAS versus CLK inhibitors. The therapeutic potential of RECTAS is validated in multiple FD disease models. Our study indicates that small synthetic molecules affecting phosphorylation state of SRSFs is available as a new therapeutic modality for mechanism-oriented precision medicine of splicing diseases., 遺伝病を薬で治す --家族制自律神経失調症に対する低分子化合物による効果を実証--. 京都大学プレスリリース. 2021-07-28.

The objectives of this study are to clarify the significance of persistent descending mesocolon (PDM), a kind of intestinal malrotation, in laparoscopic colorectal surgery and present potentially useful preoperative diagnostic methods for PDM. Although several risk factors for laparoscopic colorectal surgery have been convincingly reported, the impact of PDM on laparoscopic surgery for colorectal cancer remains less studied. This was an observational study with a retrospective analysis. A consecutive 110 patients undergoing laparoscopic colorectal surgery for colorectal cancer were included. To identify risk factors for operative time of laparoscopic surgery for colorectal cancer, we examined age, sex, body mass index, American Society of Anesthesiologists Performance Status score, tumor location, depth of tumor invasion, lymph node metastasis, and PDM as potential risk factors. For identification of appropriate preoperative diagnostic imaging, we reviewed three-dimensional vessel images reconstructed from computed tomographic slice data of all patients. During the study period, no effective pre- or intraoperative diagnoses of PDM were achieved. A total of 4 patients were diagnosed with PDM. Sex (P = 0.0032); tumor location (P = 0.0044); lymph node metastasis (P = 0.022); and PDM (P = 0.0007) were identified as risk factors based on multivariate analysis. A ventrally branched left colic artery visualized by three-dimensional imaging appeared to be a highly specific feature of PDM. Laparoscopic surgery for colorectal cancer with PDM was difficult without the recognition of PDM. PDM was well-defined preoperatively using three-dimensional vessels images reconstructed from computed tomographic slice data.

A simple chromatographic model including extra-column sample bandspreading is built and validated experimentally. It is used to quantify the advantage of slowly transporting under isocratic elution of the injected sample band along the pre-column volume of the chromatographic system compared to the conventional injection method at constant flow rate. For fast analyses ( 30 s), the model allows for the determination of the optimum and slow injection speed that maximizes the trade-off between the analysis time and the isocratic peak capacity. For 2.1 mm × 20 mm columns packed with 2 μm particles and a highest retention factor of 10, the optimum injection speed is about 10–15% of the operating column flow rate for a maximum relative gain of 5% in overall isocratic peak capacity at constant elution time. Overall, the proposed injection method is directly applicable for enhanced resolution of weakly retained polar compounds in RPLC without the need of changing separation conditions, which may strongly increase the retention times of the late apolar eluters.

The skin barrier protects our body from water loss, allergens and pathogens. Profilaggrin (proFLG) is produced by differentiated keratinocytes and is processed into FLG monomers. These monomers crosslink keratin filaments and are also decomposed to natural moisturizing factors in the stratum corneum for skin hydration and barrier function. Deficits in FLG expression impair skin barrier function and underlie skin diseases such as dry skin and atopic dermatitis (AD). However, intrinsic factors that regulate FLG expression and their mechanism of action remain unknown. Here, we show that lysophosphatidic acid (LPA) induces FLG expression in human keratinocytes via the LPAR1 and LPAR5 receptors and the downstream RHO-ROCK-SRF pathway. Comprehensive gene profiling analysis further revealed that LPA not only induces FLG expression but also facilitates keratinocyte differentiation. Moreover, LPA treatment significantly upregulated FLG production in a three-dimensional culture model of human skin, and promoted barrier function in mouse skin in vivo. Thus, our work demonstrates a previously unsuspected role for LPA and its downstream signaling in the maintenance of skin homeostasis, which may serve as a novel therapeutic target for skin barrier dysfunction., ヒト表皮細胞の分化と皮膚バリア機能の調節機構を解明 --アトピー性皮膚炎の新たな治療戦略へ向けて--. 京都大学プレスリリース. 2018-11-16.

Background Clostridioides (Clostridium) difficile infection (CDI) has become an increasingly significant disease not only as healthcare-associated infection, but also as community-acquired (CA) infection worldwide. CDI caused by the NAP1/BI/027 strain is reported to be more severe, difficult to cure, and frequently associated with recurrences in North America and Europe. Case presentation A 68-year-old woman was referred to our hospital for continuous lower abdominal pain 4 weeks after eradication therapy against Helicobacter pylori. While she was treated with fasting on the suspicion of ischemic colitis, she experienced septic shock. Emergent subtotal proctocolectomy revealed fulminant pseudomembranous C. difficile colitis. The C. difficile isolate recovered from the patient was identified as ribotype 027, which has been reported to be uncommon in Japan. Conclusion We report a rare case of CA fulminant pseudomembranous colitis caused by ribotype 027 C. difficile after H. pylori eradication therapy.

We investigate the intensity interference between pairs of electrons using a spin-polarized electron beam having a high polarization and a narrow energy width. We observe spin-dependent antibunching on the basis of coincident counts of electron pairs performed with a spin-polarized transmission electron microscope, which could control the spin-polarization without any changes in the electron optics. The experimental results show that the time correlation was only affected by the spin polarization, demonstrating that the antibunching is associated with fermionic statistics. The coherent spin-polarized electron beam facilitates the extraction of intrinsic quantum interference.

Sample introduction method was studied to reduce the extra-column effect in reversed-phase HPLC. Slow transport of a sample band (SToSB) in the pre-column space followed by the introduction of the band into the column at a near-optimum flow rate resulted in larger plate counts for a 1.0 mmID, 5 cm long column as much as 1.4-1.6 times for solutes with a retention factor (k) of 0.5-1.8 compared to a conventional elution method. Further reduction of the extra-column effect was possible by orthogonally splitting the sample band (SplSB) by flow switching during its slow transport followed by the introduction of the leading part of the band into the column. In this case, increased plate counts of up to 2-3 times for solutes with k of 0.5-1.8 were observed for a 1.0 mmID, 5 cm column. The sample introduction method, SToSB in the injector and the pre-column tube of a few μL, was found to reduce the extra-column band variance by 0.4-0.5 μL2 for an UHPLC system with the extra-column volume (Vextra) of ca. 4.6 μL and the system variance (σextra2) of 1.1 μL2 at flow rate of 100 μL/min, while SToSB and subsequent SplSB were found to be more effective, reducing σextra2 by about 0.8 μL2. With an UHPLC instrument with Vextra of about 10 μL and σextra2 of ca. 3.6 μL2 at flow rate of 300 μL/min, 1.4-2.1 times as many plate counts were observed with SToSB and SplSB compared to the normal elution method for early-eluting solutes with k=0.25-1.7 for a column, 2.1 mmID, 5 cm long. With this UHPLC instrument, SToSB and/or SplSB resulted in the reduction of σextra2 by 1.2-2.2 μL2.

Active S1PR3 structure reveals the unique ligand-binding mode and signaling selectivity switching mechanism., Sphingosine-1-phosphate (S1P) regulates numerous important physiological functions, including immune response and vascular integrity, via its cognate receptors (S1PR1 to S1PR5); however, it remains unclear how S1P activates S1PRs upon binding. Here, we determined the crystal structure of the active human S1PR3 in complex with its natural agonist S1P at 3.2-Å resolution. S1P exhibits an unbent conformation in the long tunnel, which penetrates through the receptor obliquely. Compared with the inactive S1PR1 structure, four residues surrounding the alkyl tail of S1P (the “quartet core”) exhibit orchestrating rotamer changes that accommodate the moiety, thereby inducing an active conformation. In addition, we reveal that the quartet core determines G protein selectivity of S1PR3. These results offer insight into the structural basis of activation and biased signaling in G protein–coupled receptors and will help the design of biased ligands for optimized therapeutics.

Increasing the separation efficiency and understanding the interactions associated with the columns and the stationary phases are some of the major objectives of fundamental studies on liquid chromatography. The separation of isotopic compounds is significant in separation science for how it illustrates the extremely high ability of high performance liquid chromatography systems, and has its own significance, too, as a longtime target of scientific curiosity. Isotopic separation is an interesting subject for separation science by itself because of the high similarity in the solute structure. Fundamental information on molecular interactions will be helpful for understanding the retention behaviors of various solutes in combination with diverse stationary phases and mobile phases. Difficult separations have often been carried out by recycle chromatography using a series of several columns to allow the solute mixture band to go through the columns many times before being eluted out.

Fast enantiomeric separation of amino acids was studied by liquid chromatography/mass spectrometry (LC/MS) on a chiral crown ether stationary phase. A chiral crown ether bonded silica column (3 mm internal diameter (i.d.), 5 cm long) packed with 3 μm particles was employed instead of a 15 cm column packed with 5 μm particles used in our previous study. In addition, the extra-column variance, becoming more serious for smaller columns, was reduced by replacing 0.127 mm i.d. post-column tubes with shorter, smaller-diameter (0.0635 mm i.d.) tubes. The results demonstrated the benefits of using shorter columns packed with smaller particles and the reduction of the extra-column band broadening for fast enantiomeric separation. Finally, the enantiomeric separation of 18 pairs of proteinogenic amino acids was achieved within 2 min with a resolution (Rs) > 1.5 for each pair using an isocratic mobile phase of acetonitrile/water/trifluoroacetic acid (ACN/W/TFA) = 96/4/0.5, and a flow rate 1.2 mL/min at 30°C. This is the highest throughput method for simultaneous chiral separation of all proteinogenic amino acids except proline to date.

We report hydrogen/deuterium (H/D) isotope effects based on weak intermolecular interactions with polar functional groups and aromatic rings in liquid chromatography (LC). Various LC experiments with different aromatic analytes, separation media, and nonpolar mobile phases were conducted under normal phase LC conditions, where the hydrophobic interaction was completely suppressed. The separation media that had polar functional groups, such as silanol groups, allowed for higher separation efficiencies for the pairs of aromatic H/D isotopologues. In comparing the 13C NMR spectra of protiated and deuterated aromatic analytes, the electron density of the deuterated analyte was found to be slightly higher than that of the protiated analytes. In the case of silanol functional groups, aromatic rings of the analyte acted as donors through the OH-π interaction to hydrogen atoms in the silanol groups. Thus, the deuterated analytes were able to be greatly retained by the stronger OH-π interactions. Furthermore, a C70-fullerene bonded monolithic column (C70 column), which effectively provides CH-π interactions, allowed the opposite isotope effect. Briefly, an electrostatic attraction based on the dipole-(induced) dipole interaction dominated in the CH-π interactions, according to a van't Hoff analysis. Hence, the bonding lengths of the C-H or D bonds were sensitively affected, such that we were able to conclude that the CH-π interaction depended on the geometric effect. Applying these opposing H/D isotope effects, we were able to finally demonstrate effective H/D isotopologue separations by utilizing the complementary action of the OH-π and CH-π interactions.

The separation mechanism of amino acid enantiomers using a chiral crown ether-bonded stationary phase, CROWNPAK CR-I(+), and acetonitrile (ACN)-rich mobile phases (MPs) was studied. The retention factors of proteinogenic l - amino acids (except proline) formed U-shaped plots against the ACN content in the MP with a sharp increase at a high ACN content, while d - amino acids showed much smaller increases or monotonous decreases in retention within the same range. The use of an acidic, highly organic MP with trifluoroacetic acid (TFA) provided a high enantioselectivity with a short separation time from the contribution of the increased binding of the ammonium group of the analytes to the crown ether functionality of the stationary phase and electrostatic repulsion counteracting the hydrophilic partition mechanism. Optimizing the sample diluent and MP alleviated the peak distortion caused by a moving water band that accompanied the hydrophilic interaction liquid chromatography-like elution conditions. The liquid chromatography/time-of-flight mass spectrometry method with the optimized MP — ACN/ethanol/water/TFA = 80/15/5/0.5 (v/v/v/v) — enabled the determination of eighteen pairs of proteinogenic amino acid enantiomers within 10 min. The conditions also provided the following advantages: (i) fast and highly reproducible separations under isocratic conditions, (ii) high sensitivity and low backpressure using the MP with a high organic content, and (iii) highly reliable peak identification by combining two columns (CR-I(+) and CR-I(-)), reversing the elution orders of the enantiomers.

Extra-column band dispersion during the transport of a sample band from the injector to the column can be reduced by a flow rate program starting with a low flow rate until the sample band has approached to, or just entered into the column, followed by an increased flow rate suitable for the solute separation in the column. Such a sample introduction method increased the plate counts of a 50 mm long column, 1.0 or 2.1 mmID, especially for early-eluting solutes by up to several times compared to a conventional elution method, when a 0.254 mmID, 15.2 cm connection tubing was used. Increase in plate counts of up to 50–70% was possible for solutes with retention factors smaller than 1.0 for the columns connected with a 0.13 mmID, 15 cm tube. The method also seems to reduce the contribution of the void space at the column inlet to the band dispersion. The elution method including a slow transport of the sample band in the pre-column space of 10 μL or less may require a little longer separation time than normal elution, but it was shown to be effective for increasing the observed efficiency of a small column for solutes with small retention factors.

This paper is concerned with the generation of a quiet space in a rectangular cavity using active wave control methodology. It is the purpose of this paper to present the wave filtering method for a rectangular cavity using multiple microphones and its application to an adaptive feedforward control system. Firstly, the transfer matrix method is introduced for describing the wave dynamics of the sound field, and then feedforward control laws for eliminating transmitted waves is derived. Furthermore, some numerical simulations are conducted that show the best possible result of active wave control. This is followed by the derivation of the wave filtering equations that indicates the structure of the wave filter. It is clarified that the wave filter consists of three portions; modal group filter, rearrangement filter and wave decomposition filter. Next, from a numerical point of view, the accuracy of the wave decomposition filter which is expressed as a function of frequency is investigated using condition numbers. Finally, an experiment on the adaptive feedforward control system using the wave filter is carried out, demonstrating that a quiet space is generated in the target space by the proposed method.

Patients with strangulating small bowel obstructions (SBOs) can rapidly deteriorate, in condition; therefore, immediate and appropriate diagnosis is required. However, some cases of SBO are difficult to diagnose using axial computed tomography (CT) images alone. The impact of 3D vessel imaging for the diagnosis, surgical indication, and timing of strangulating SBOs was investigated, prospectively. Clinical data were collected for 111 strangulating SBOs and 48 simple SBOs from patients receiving surgical interventions from January 2009 to March 2018. The accuracy of preoperative diagnoses for the type of SBO was evaluated. Among 159 patients, 27 underwent contrast-enhanced CT imaging as well as prospectively reconstructed 3D vessel imaging of the superior mesenteric artery, vein, and branches. The concordance rate of operative findings and preoperative diagnoses of the type of SBO were compared between axial CT imaging alone and combination of axial and 3D vessel imaging. Overall concordance rate of diagnosis for the type of SBO by axial imaging was 93.1% and that of strangulating and simple SBOs was 92.8% and 93.8%, respectively. Combined axial and 3D vessel imaging resulted in 100% accuracy of preoperative diagnoses for both types of SBO. In addition, abnormalities could be classified from 3D vessel images as central twists or peripheral twists, and deteriorated vascular flow could also be detected. The combination of axial imaging and 3D vessel imaging can be used to accurately diagnose SBOs, and this imaging technique may be useful for determining the surgical indication and suitable timing of strangulating SBOs.

A 74-year-old man with aspiration pneumonia was admitted in the internal medicine department. CT revealed progressive carcinoma of RS-Ra, which became the focus of intervention after the pneumonia was treated. After having been allowed temporary discharge, the patient was rehospitalized for surgical operation and rehabilitation. During the perioperative period of cancer patients, we use body distribution data for teaching and environment setting, which is a useful tool in rehabilitation. Rectal cancer was observed after hospitalization for pneumonia, presenting an interesting case. Therefore, care needs to be taken as body pressure distribution may be modified by comorbidity.

In this article, we demonstrate that a convolutional neural network (CNN) can be effectively used to determine the presence of twins in the atomic resolution scanning transmission electron microscopy (STEM) images of catalytic Au nanoparticles. In particular, the CNN screening of Hough transformed images resulted in significantly higher accuracy rates as compared to those obtained by applying this technique to the raw STEM images. The proposed method can be utilized for evaluating the statistical twining fraction of Au nanoparticles that strongly affects their catalytic activity.

This paper deals with the active control of sound transmission through a rectangular honeycomb panel. The authors have proposed an effective control method using point force actuators and PVDF film sensors to suppress the transmitted sound power through a thin flexible panel in a low-frequency range before. With the proposed method, the frequency range in which the control effect can be obtained depends on the natural frequency of the panel since the method can control the lowest three odd/odd structural modes. Therefore, in order to make the control frequency range higher, a honeycomb panel, which has high strength-to-weight ratio, is used as a target panel in this study. However, when the honeycomb panel is used, the characteristics of sound transmission are totally changed and then the control effect decreases around even/odd, odd/even and even/even mode frequencies. Hence, in this study, active control method comprising both feedforward and feedback control is investigated theoretically and experimentally. The direct velocity feedback control is added to the previously proposed SISO feedforward control system in order to suppress resonances of the even order vibration modes. The results show that the feedback control can improve the control effect around even order structural mode frequencies and that the proposed control method using a honeycomb panel is capable of proceeding the significant control effect for improving the sound insulation property over a wide frequency range.

This paper addresses active sound transmission control based on structural sensors and actuators. The proposed methodology is to independently measure and control the targeted structural modes, which significantly contribute to sound transmission, with structural modal filters, i.e., modal sensors and modal actuators. The targeting is performed by using modal sound transmission coefficients before control as the criteria. The modal sound transmission coefficient enables the contribution from a structural mode to the sound transmission via the modal interaction with the other structural modes to be determined. The structural modal filters effectively facilitate decreasing the sound transmission and guarantee that the structural vibration and near-field sound, side effects of sound transmission control, will not increase. It is shown with numerical examples that sound transmission can be reduced significantly in a broad frequency band by controlling a small number of structural modes and neither the structural vibration nor near-field sound are increased.

An improved unroofing method consisting of tearing off the cell membrane using an adhesive electron microscopy (EM) grid instead of vitreous ice sectioning (cryo-sectioning) has enabled us to panoramically view the membrane cytoskeleton in its native state with extremely high contrast. Grids pre-treated with Alcian blue were placed on cells, and a portion of the dorsal plasma membrane was transferred onto the grid, which was then floated in buffer solution. These membrane fragments contained sufficient cytoskeleton and were of suitable thickness for observation by cryo-EM. Many actin filaments and microtubules were clearly observed on the cytoplasmic surface of the plasma membrane with extremely high contrast because the soluble components of the cytoplasm flowed out and broke away from the cells. Actin filaments extended in all directions in a smooth contour with little branching. Microtubules spread out as far as 3 µm or more while winding gently in their native state. Upon fixation with 1% glutaraldehyde, however, the microtubules became straight and fragmented. Cryo-EM revealed for the first time a smooth endoplasmic reticulum network beneath the cell membrane in native cells. Clathrin coats and caveolae were also observed on the cytoplasmic surface of the plasma membrane, similar to those seen using freeze-etching replica EM (freeze-etching EM). Unroofing was also useful for immuno-labelling in cryo-EM. Antibody-labelled IQGAP1, one of the effector proteins facilitating the formation of actin filament networks, was localized alongside actin filaments. Freeze-etching EM confirmed the morphological findings of cryo-EM.

In order to directly investigate the grain boundary (GB) hydrogen embrittlement in polycrystalline materials, a novel micro-mechanical testing method was developed. By combining a site-specific sampling technique and a high-voltage environmental transmission electron microscope (HV ETEM), the fracture property of micro-cantilever specimens fabricated from the same GB in a nickel-aluminide (Ni 3 Al) polycrystal was critically compared in environments with/without hydrogen (H 2 ) gas. For randomly oriented GBs, brittle fracture nucleation accompanied by plastic deformation was observed in a H 2 -containing environment except for ones with small orientation difference. No GB fracture was observed for coherent Σ3 boundaries. It also appeared that the similitude of the hydrogen-enhanced decohesion (HEDE) mechanism was still valid even for the submicron-scale specimens.

The taste and quality of red wine are determined by its highly complex mixture of polyphenols and many other metabolites. No single method can fully cover the full metabolome, but even for polyphenols and related compounds, current methods proved inadequate. We optimized liquid chromatography resolution and sensitivity using 1 mm i.d. columns with microLC pumps and compared data-dependent to data-independent (SWATH) MS/MS acquisitions. A high-throughput microLC-MS method was developed with a 4 min gradient at 0.05 mL/min flow rate on a Kinetex C18 column and Sciex TripleTOF mass spectrometry. Using the novel software MS-DIAL, we structurally annotated 264 compounds including 165 polyphenols in six commercial red wines by accurate mass MS/MS matching. As proof of concept, multivariate statistics revealed the difference in the metabolite profiles of the six red wines, and regression analysis linked the polyphenol contents to the taste of the red wines.

This paper presents a theoretical study on the modelling and active control of bending waves propagating in an orthotropic rectangular panel. The main objectives are to clarify the characteristics of the wave dynamics of an orthotropic rectangular panel and to propose the feedforward control of wave propagation based on a transfer matrix method. As a result of the numerical investigation of the wave dynamics, it is found that there are two types of cut-on frequency in the orthotropic rectangular panel, and the type of bending waves are categorised into progressive, evanescent, and amplitude-varying progressive waves. Next, after the reflected wave absorbing control (RWAC) and the transmitted wave eliminating control (TWEC) laws are derived, numerical simulations on an active wave control system are performed. It is clarified that if the number of control forces is same as that of target mode groups, the RWAC enables the inactivation of vibration modes, and the TWEC enables the vibration-free state in the orthotropic rectangular panel. Moreover, it is concluded that if the number of control forces is lower than that of target mode group, the optimal position of the control force is around the nodal line of the non-targeted mode group which is closer to the disturbance force.

A new environmental high-voltage transmission electron microscope (E-HVEM) was developed by Nagoya University in collaboration with JEOL Ltd. An open-type environmental cell was employed to enable in-situ observations of chemical reactions on catalyst particles as well as mechanical deformation in gaseous conditions. One of the reasons for success was the application of high-voltage transmission electron microscopy to environmental (in-situ) observations in the gas atmosphere because of high transmission of electrons through gas layers and thick samples. Knock-on damages to samples by high-energy electrons were carefully considered. In this paper, we describe the detailed design of the E-HVEM, recent developments and various applications. This article is part of a discussion meeting issue ‘Dynamic in situ microscopy relating structure and function'.

Pulse beam emission in a spin-polarized pulse-TEM (SP-TEM) was performed using a combination of a semiconductor photocathode and an ultra-short pulse laser, which has an ability of a time-resolved measurement. The photocathode has high quantum efficiency of the order of 10-3 comparing with other metal-type photocathode, which can realize a wide range of the pulse duration from a continuous emission to a pico-second pulse emission. The SP-TEM has several advantages of a high brightness of 3.1×108 A cm-2 sr-1, a narrow energy width of 114meV and a long coherence length of 200 nm in a continuous mode. Time-resolved TEM image and pulsed interference fringes were also conducted successfully with a stroboscopic acquisition technique. Consequently, instead of a high current density, the pulsed electron beam emitted from the photocathode has enough coherence to realize a time-resolved holography that can observe phase information in a temporal space.

In this article, we demonstrate that a convolutional neural network (CNN) can be effectively used to determine the presence of twins in the atomic resolution scanning transmission electron microscopy (STEM) images of catalytic Au nanoparticles. In particular, the CNN screening of Hough transformed images resulted in significantly higher accuracy rates as compared to those obtained by applying this technique to the raw STEM images. The proposed method can be utilized for evaluating the statistical twining fraction of Au nanoparticles that strongly affects their catalytic activity.