Anti-adsorption Mechanism of Photoresist by Pluronic Surfactants: An Insight into Their Adsorbed Structure.

Photoresist stripping is the final step in the photolithography process that forms fine patterns for electronic devices. Recently, a mixture of ethylene carbonate (EC) and propylene carbonate (PC) has attracted attention as a new stripper based on its eco-friendliness and anti-corrosiveness. However, the EC/PC mixture causes re-adsorption of the photoresist during a process of subsequent water rinsing. In this study, we characterized the adsorption/desorption of the photoresist and a triblock Pluronic surfactant [poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)] as a blocking agent on an indium tin oxide (ITO) substrate. In addition, we evaluated the dispersion of photoresist particles. The photoresist polymer formed a thin and rigid adsorption layer on an ITO substrate in the EC/PC mixture. When water was injected into the EC/PC mixture and the photoresist solutions, the photoresist polymer aggregated and was then deposited on the substrate. In contrast, the addition of Pluronic surfactant F-68 (PEO79PPO30PEO79) into the EC/PC mixture remarkably decreased the residual amount of the photoresist on the ITO after water injection. This variation was attributed to the PEO blocks of F-68 extended to the solution phase, whereas the PPO blocks of F-68 functioned as anchors for adsorption onto the photoresist. Therefore, the F-68-adsorbed layer prevented interaction between the photoresist particles or the photoresist and the ITO surface, which provides potential for future applications as new stripping agents with high removal performance.

Induction of Paraptosis by Cyclometalated Iridium Complex-Peptide Hybrids and CGP37157 via a Mitochondrial Ca2+ Overload Triggered by Membrane Fusion between Mitochondria and the Endoplasmic Reticulum.

We previously reported that a cyclometalated iridium (Ir) complex-peptide hybrid (IPH) 4 functionalized with a cationic KKKGG peptide unit on the 2-phenylpyridine ligand induces paraptosis, a relatively newly found programmed cell death, in cancer cells (Jurkat cells) via the direct transport of calcium (Ca2+) from the endoplasmic reticulum (ER) to mitochondria. Here, we describe that CGP37157, an inhibitor of a mitochondrial sodium (Na+)/Ca2+ exchanger, induces paraptosis in Jurkat cells via intracellular pathways similar to those induced by 4. The findings allow us to suggest that the induction of paraptosis by 4 and CGP37157 is associated with membrane fusion between mitochondria and the ER, subsequent Ca2+ influx from the ER to mitochondria, and a decrease in the mitochondrial membrane potential (ΔΨm). On the contrary, celastrol, a naturally occurring triterpenoid that had been reported as a paraptosis inducer in cancer cells, negligibly induces mitochondria-ER membrane fusion. Consequently, we conclude that the paraptosis induced by 4 and CGP37157 (termed paraptosis II herein) proceeds via a signaling pathway different from that of the previously known paraptosis induced by celastrol, a process that negligibly involves membrane fusion between mitochondria and the ER (termed paraptosis I herein).

Design, Synthesis, and Anticancer Activity of Triptycene-Peptide Hybrids that Induce Paraptotic Cell Death in Cancer Cells.

We report on the design and synthesis of triptycene-peptide hybrids (TPHs), 5, syn-6, and anti-6, which are conjugates of a triptycene core unit with two or three cationic KKKGG peptides (K: lysine and G: glycine) through a C8 alkyl chain. It was discovered that syn-6 and anti-6 induce paraptosis, a type of programmed cell death (PCD), in Jurkat cells (leukemia T-lymphocytes). Mechanistic studies indicate that these TPHs induce the transfer of Ca2+ from the endoplasmic reticulum (ER) to mitochondria, a loss of mitochondrial membrane potential (ΔΨm), tethering of the ER and mitochondria, and cytoplasmic vacuolization in the paraptosis processes.

Meals and Room Temperature Storage do not Significantly Affect Feasibility of Direct RT-PCR Tests for SARS-CoV-2 Using Saliva.

BACKGROUND: Rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using saliva samples has emerged as a preferred technique since sample collection is easy and noninvasive. In addition, several commercial high-throughput PCR kits that do not require RNA extraction/purification have been developed and are now available for testing saliva samples. However, an optimal protocol for SARS-CoV-2 RT-PCR testing of saliva samples using the RNA extraction/purification-free kits has not yet been established. The aim of this study was to establish optimal preanalytical conditions, including saliva sample collection, storage, and dilution for RNA extraction/purification-free RT-PCR (direct RT-PCR). METHODS: Patients suspected with COVID-19 from March 02 to August 31, 2020, were enrolled in this study. A total of 248 samples, including 43 nasopharyngeal swabs and 205 saliva samples, were collected from 66 patients (37 outpatients and 29 inpatients) and tested using the 2019 Novel Coronavirus Detection Kit (nCoV-DK, Shimadzu Corporation, Kyoto, Japan). RESULTS: The detection results obtained using nasopharyngeal swabs and saliva samples matched 100%. The sampling time, i.e., either awakening time or post-breakfast, had no significant effect on the viral load of the saliva samples. Although saliva samples are routinely diluted to reduce viscosity, we observed that dilution negatively affected PCR sensitivity. Saliva samples could be stored at room temperature (25°C) for 24 hours or at 4°C for up to 48 hours. CONCLUSIONS: This study demonstrated the appropriate conditions of saliva sample collection, processing, and storage, and indicated that the nCoV-DK is applicable to saliva samples, making the diagnosis method simple and safe.

Cyclometalated Iridium(III) Complex-Cationic Peptide Hybrids Trigger Paraptosis in Cancer Cells via an Intracellular Ca2+ Overload from the Endoplasmic Reticulum and a Decrease in Mitochondrial Membrane Potential.

In our previous paper, we reported that amphiphilic Ir complex-peptide hybrids (IPHs) containing basic peptides such as KK(K)GG (K: lysine, G: glycine) (e.g., ASb-2) exhibited potent anticancer activity against Jurkat cells, with the dead cells showing a strong green emission. Our initial mechanistic studies of this cell death suggest that IPHs would bind to the calcium (Ca2+)-calmodulin (CaM) complex and induce an overload of intracellular Ca2+, resulting in the induction of non-apoptotic programmed cell death. In this work, we conduct a detailed mechanistic study of cell death induced by ASb-2, a typical example of IPHs, and describe how ASb-2 induces paraptotic programmed cell death in a manner similar to that of celastrol, a naturally occurring triterpenoid that is known to function as a paraptosis inducer in cancer cells. It is suggested that ASb-2 (50 µM) induces ER stress and decreases the mitochondrial membrane potential (ΔΨm), thus triggering intracellular signaling pathways and resulting in cytoplasmic vacuolization in Jurkat cells (which is a typical phenomenon of paraptosis), while the change in ΔΨm values is negligibly induced by celastrol and curcumin. Other experimental data imply that both ASb-2 and celastrol induce paraptotic cell death in Jurkat cells, but this induction occurs via different signaling pathways.

Phase Behavior and Polymerization of the Ternary Polymerizable Cationic Gemini Surfactant/Fatty Alcohol/Water System.

We studied the phase behavior of a ternary polymerizable gemini surfactant (PC11-6-11)/1-undecanol/water system and stabilized these liquid crystalline structures through the polymerization of surfactants. The addition of 1-undecanol to a PC11-6-11/water system formed bicontinuous cubic (V1) and reversed hexagonal (H2) liquid crystal phases in addition to hexagonal (H1) and lamellar (Lα) phases, which were also formed using the binary system of PC11-6-11/water. These new phases were formed because the fatty alcohol penetrated the palisade layer of the PC11-6-11 micelles. The polymerization of PC11-6-11 with a thermal initiator successfully preserved the Lα and H2 phases. Layered or honeycomb structures of these liquid crystals were clearly observed by transmission electron microscopy. The nanomaterials have potential applications as membranes for nano- or microfiltration and catalyst support materials.

Comparison of the Analytical Performance Between cobas EGFR Assay and PCR-Clamp Method in the Detection of EGFR Mutations in Japanese Non-Small Cell Lung Cancer Patients.

BACKGROUND: EGFR, a tyrosine-kinase, plays an important role in the progression of lung cancer. Since genetic abnormality of EGFR alters the effects of tyrosine-kinase inhibitors targeting EGFR, molecular analyses of EGFR have recently gained more attention in the treatment of lung cancer. However, several different techniques are available and which method is superior has not been determined. In this study, we compared two recently developed PCR-based techniques, PCR-clamp method and cobas EGFR assay. METHODS: Ninety-four surgical samples and 58 biopsy samples from patients suffering from non-small cell lung cancers (NSCLCs) were included in the study. Samples with positive and negative genetic abnormalities, 66 and 28 respectively, were chosen for PCR-Clamp methods. Those same samples were reanalyzed with cobas EGFR assay. RESULTS: The concordance between PCR-Clamp and cobas EGFR methods was 95.7%. PCR-Clamp failed to detect four mutations that were detected with cobas EGFR assay. These two methods were further tested by analyzing 58 random biopsy samples. The concordance for the biopsy samples was 93.1%, and PCR-Clamp, again, failed to detect three mutations that were detected with cobas EGFR assay. CONCLUSIONS: Our results showed both methods detected most of the known EGFR mutations and the concordance was similar to those previously reported in different ethnicities. However, in our study, PCR-Clamp method failed to detect a total of seven mutations that were detected with cobas EGFR assay. Thus, we concluded that cobas EGFR assay is an easier and more accurate screening assay than PCR-Clamp method in detecting EGFR genetic abnormalities.

[Tricuspid Valve Replacement in a Case of an Adult Patient with Corrected Transposition of the Great Arteries；Report of a Case].

The patient was a 69-year-old man with corrected transposition of the great arteries. Chest X-ray abnormality had been pointed out since his childhood. Recently he was admitted with congestive heart failure. Examination revealed severe regurgitation of the tricuspid valve (systemic atrioventricular valve) with mild systemic ventricular dysfunction. After a median sternotomy, the operation was conducted with the surgeon standing on the patient's left side. Tricuspid valve was approached through left superior atriotomy. Tricuspid valve was facing almost dorsal to the patient, and there was a big cleft between anterior and posterior leaflets. Tricuspid valve replacement with a mechanical valve was performed with leaflets preserved. The patients had a favorable postoperative course.

Circulating TNF receptor levels are associated with estimated glomerular filtration rate even in healthy individuals with normal kidney function.

The association between serum tumor necrosis factor receptor (TNFRs: TNFR1, TNFR2) levels and estimated glomerular filtration rate (eGFR) observed in patients with diabetes has not been comprehensively tested in healthy subjects with normal kidney function. It also remains unclear whether TNFR levels differ by age and sex, and between healthy subjects and diabetics. We measured serum TNFR levels in 413 healthy subjects and 292 patients with type 2 diabetes. In healthy subjects, TNFR levels did not differ between men and women. Additionally, TNFR2, but not TNFR1, levels increased with age. In multivariate analysis, TNFR1 was associated only with cystatin C-based eGFR (eGFR-CysC), whereas TNFR2 was associated with systolic blood pressure in addition to eGFR-CysC. Both TNFRs were associated with lower eGFR (eGFR-Cys < 90 mL/min/1.73 m2) even after adjustment for relevant clinical factors. Upon combining healthy subjects and patients with diabetes, the presence of diabetes and elevated glycated hemoglobin level were significant factors in determining TNFR levels. TNFR levels were associated with eGFR-CysC, but were not affected by age and sex in healthy subjects with normal kidney function. TNFR levels in patients with diabetes appeared to be higher than in healthy subjects.

Corrigendum: SARS-CoV-2 evolution among patients with immunosuppression in a nosocomial cluster of a Japanese medical center during the Delta (AY.29 sublineage) surge.

[This corrects the article DOI: 10.3389/fmicb.2023.944369.].

Photorheological response of aqueous wormlike micelles with photocleavable surfactant.

Recently, we have reported a new cinnamic acid-type photocleavable surfactant, C4-C-N-PEG9 that experiences a photocleavage through UV-induced cyclization in aqueous solution, yielding a coumarin derivative (7-butoxy-2H-chromen-2-one) and an aminated polyoxyethylene compound. Here, we have studied the effects of C4-C-N-PEG9 on the photorheological behavior of viscoelastic wormlike micelles formed by aqueous mixture of nonionic surfactants, polyoxyethylene phytosterol ether (PhyEO20) and tetraoxyethylene dodecyl ether (C12EO4). The 4.9 wt % PhyEO20/H2O + 2.4 wt % C12EO4 solution forms wormlike micelles, and its viscosity is ~10 Pa·s. We have found that the addition of C4-C-N-PEG9 into this viscous, non-Newtonian fluid system decreases the viscosity. Viscosity decreased in parallel to the C4-C-N-PEG9 concentration reaching ~0.003 Pa·s at 2.5 wt % of C4-C-N-PEG9. However, viscosity of the C4-C-N-PEG9 incorporated system increased significantly (~200 times at 1.5 wt % of C4-C-N-PEG9 system) upon UV irradiation. Small-Angle X-ray scattering studies have shown that addition of C4-C-N-PEG9 favors wormlike-to-sphere type transition in the micellar structure. However, UV irradiation in the C4-C-N-PEG9 incorporated system causes one-dimensional micellar growth. Since C4-C-N-PEG9 has relatively bigger headgroup size compared to the C12EO4, addition of C4-C-N-PEG9 into wormlike micelles reduces the critical packing parameter resulting in the formation of spherical aggregates. UV irradiation induced one-dimensional micellar growth is caused due to photocleavage of the C4-C-N-PEG9 into a less surface-active coumarin derivative and an aminated polyoxyethylene compound, as confirmed by UV-vis spectrometry and HPLC measurements. The hydrophobic coumarin derivative formed after cleavage of C4-C-N-PEG9 goes to the micellar core and is responsible for decreasing the viscosity. However, the hydrophilic aminated polyoxyethylene prefers to reside at the vicinity of headgroup of PhyEO20 reducing the interhead repulsion, increasing the critical packing parameter and the viscosity as well.

SARS-CoV-2 evolution among patients with immunosuppression in a nosocomial cluster of a Japanese medical center during the Delta (AY.29 sublineage) surge.

Background: Previous studies have shown that patients with immunosuppression tend to have longer-lasting SARS-CoV-2 infections and a number of mutations were observed during the infection period. However, these studies were, in general, conducted longitudinally. Mutation evolution among groups of patients with immunosuppression have not been well studied, especially among Asian populations. Methods: Our study targeted a nosocomial cluster of SARS-CoV-2 infection in a Japanese medical center during Delta surge (AY.29 sublineage), involving ward nurses and inpatients. Whole-genome sequencing analyses were performed to examine mutation changes. Haplotype and minor variant analyses were furtherly performed to detect the mutations on the viral genomes in detail. In addition, sequences of the first wild-type strain hCoV-19/Wuhan/WIV04/2019 and AY.29 wild-type strain hCoV-19/Japan/TKYK15779/2021 were used as references to assess the phylogenetical development of this cluster. Results: A total of 6 nurses and 14 inpatients were identified as a nosocomial cluster from September 14 through 28, 2021. All were Delta variant (AY.29 sublineage) positive. 92.9% of infected patients (13 out of 14) were either cancer patients and/or receiving immunosuppressive or steroid treatments. Compared to AY.29 wild type, a total of 12 mutations were found in the 20 cases. Haplotype analysis found one index group of eight cases with F274F (N) mutation and 10 other haplotypes with one to three additional mutations. Furthermore, we found that cases with more than three minor variants were all cancer patients under immunosuppressive treatments. The phylogenetical tree analysis, including 20 nosocomial cluster-associated viral genomes, the first wild-type strain and the AY.29 wild-type strain as references, indicated the mutation development of the AY.29 virus in this cluster. Conclusion: Our study of a nosocomial SARS-CoV-2 cluster highlights mutation acquisition during transmission. More importantly, it provided new evidence emphasizing the need to further improve infection control measures to prevent nosocomial infection among immunosuppressed patients.

Novel O/W Emulsions by Utilizing a Vesicle/Disc Transformation of Polyether Modified Silicone.

Emulsification is an important technology in the field of cosmetics and household products. Emulsions are in non-equilibrium state; therefore, the products vary depending on the preparation process, and their state changes with time. Furthermore, it is known empirically that different types of oils have different emulsification properties (preparation and stability). For these reasons, the variables in emulsification research are numerous and complicated to analyze. As a result, many industrial applications have had to rely on empirical rules. In this study, emulsions with a lamellar liquid crystalline phase as an adsorption layer at the emulsion interface were investigated. The characteristics of O/W emulsions formed with the excess solvent phases (aqueous and oil phases) separated from the lamellar liquid crystalline phase were investigated based on the phase equilibrium of the ternary system.As a result, it was found that by agitating the aqueous phase containing dispersed vesicles of emulsifier (polyether modified silicone) together with the oil phase, an emulsion with a uniform interfacial membrane of lamellar liquid crystalline phase could be obtained. The emulsions prepared by this method were found to have good stability against coalescence. The process of transformation from vesicles to the uniform liquid crystal interfacial membrane during the emulsification process was clarified by a freeze-fracture transmission electron micrograph and the calculation of interfacial membrane thickness based on precise particle size analysis. Furthermore, the emulsification properties of polyether-modified silicones were clarified using polar oils and silicone oils, which are a combination of high/low and low/high compatibility with hydrophilic (polyethylene glycol) and lipophilic (polydimethylsiloxane) groups of polyether modified silicone, respectively. It is expected that this research will lead to the evolution of various functionalities in products in the fields of cosmetics, household products, food, pharmaceuticals, paint and others.

Investigation of the individual genetic evolution of SARS-CoV-2 in a small cluster during the rapid spread of the BF.5 lineage in Tokyo, Japan.

There has been a decreasing trend in new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases and fatalities worldwide. The virus has been evolving, indicating the potential emergence of new variants and uncertainties. These challenges necessitate continued efforts in disease control and mitigation strategies. We investigated a small cluster of SARS-CoV-2 Omicron variant infections containing a common set of genomic mutations, which provided a valuable model for investigating the transmission mechanism of genetic alterations. We conducted a study at a medical center in Japan during the Omicron surge (sub-lineage BA.5), sequencing the entire SARS-CoV-2 genomes from infected individuals and evaluating the phylogenetic tree and haplotype network among the variants. We compared the mutations present in each strain within the BA.5 strain, TKYnat2317, which was first identified in Tokyo, Japan. From June 29th to July 4th 2022, nine healthcare workers (HCWs) tested positive for SARS-CoV-2 by real-time PCR. During the same period, five patients also tested positive by real-time PCR. Whole genome sequencing revealed that the infected patients belonged to either the isolated BA.2 or BA.5 sub-lineage, while the healthcare worker infections were classified as BF.5. The phylogenetic tree and haplotype network clearly showed the specificity and similarity of the HCW cluster. We identified 12 common mutations in the cluster, including I110V in nonstructural protein 4 (nsp4), A1020S in the Spike protein, and H47Y in ORF7a, compared to the BA.5 reference. Additionally, one case had the extra nucleotide-deletion mutation I27* in ORF10, and low frequencies of genetic alterations were also found in certain instances. The results of genome sequencing showed that the nine HCWs shared a set of genetic mutations, indicating transmission within the cluster. Minor mutations observed in five HCW individuals suggested the emergence of new virus variants. Five amino acid substitutions occurred in nsp3, which could potentially affect virus replication or immune escape. Intra-host evolution also generated additional mutations. The cluster exhibited a mild disease course, with individuals in this case, recovering without requiring any medical treatments. Further investigation is needed to understand the relationship between the genetic evolution of the virus and the symptoms.

Evaluation of bone marrow aspirates using the automated hematology analyzer Sysmex XN-3000.

INTRODUCTION: This study evaluated the feasibility of the Sysmex XN-3000 automated hematology analyzer for the assessment of total nucleated cells (TNC) and bone marrow (BM) cell density in routine bone marrow aspiration (BMA) samples. METHODS: A total of 54 BMA samples from 39 hematological patients were evaluated. The number of megakaryocytes was calculated by a specific gating algorithm using the body fluid mode of the WBC differential (WDF) channel. Lipid contents were calculated through a newly developed algorithm utilizing the WDF channel. The ratio of lipid particles over TNCs by the WNR channel was compared with the BM cellularity assessed by the BM biopsy. The myeloid/erythroid (M/E) ratio was calculated by measuring the number of myeloid cells in the WDF channel and the number of nucleated red blood cells (NRBCs) in the WNR channel. RESULTS: XN-3000 counts and microscopic results showed a linear correlation in TNC (R2  = .98, p < .001), megakaryocytes (R2  = .59, p = .002), NRBC (R2  = .84, p < .001), and M/E ratio (R2  = .59, p < .001). There were significant differences in the lipid/TNC ratios of hypercellular, normocellular, and hypocellular BMs measured by XN-3000 (p < .001). Receiver-operating characteristic analysis detected cut-off values of the lipid/TNC ratio of >0.4054 for hypoplasia and <0.157 for hyperplasia. The sensitivity and specificity for hypoplasia were 100% and 88%, and for hyperplasia were 89% and 86%, respectively. CONCLUSION: XN-3000 provides a quantitative assessment of BM cellularity, supporting the qualitative assessment by myelogram and BM biopsy.

Preparation of Highly Stable Oil-in-Water Emulsions with High Ethanol Content Using Polyglycerol Monofatty Acid Esters as Emulsifiers.

Oil-in-water (O/W) emulsions containing ethanol have been used in food, cosmetics, paints, and other applications. However, O/W emulsions with long-term stability are difficult to produce at high ethanol concentrations because the adsorption of the emulsifier at the O/W interface is restricted by ethanol. In this study, to resolve this issue, we prepared ethanol-containing O/W emulsions with high dispersion stability using a series of polyglycerol monofatty acid esters (PGFEs) with different fatty acid chain lengths, which are bio-safe nonionic surfactants, as emulsifiers. First, aqueous PGFE solutions containing 0-50 wt% ethanol were prepared and then O/W emulsions were formed using limonene as the oil phase. When decaglycerol stearic acid ester (DGMS, C18) was used as the emulsifier, an O/W emulsion with fine droplets (~30 nm in size) was successfully obtained at an ethanol concentration of 35 wt%. This emulsion remained stable for more than four weeks, during which no phase separation occurred, indicating its high dispersion stability. Furthermore, aqueous DGMS solutions containing 30-40 wt% ethanol were viscous, and a lamellar liquid crystal phase was observed to be dispersed in these solutions. The formation of this lamellar liquid crystal phase at the O/W interface led to an interfacial film with superior viscoelastic properties. The results suggested that the stability of the emulsions was determined by the balance between the decrease in interfacial tension caused by the addition of ethanol and the density (rigidity) of the DGMS film formed at the O/W interface. Finally, to further improve the dispersion stability of the ethanol-containing O/W-type emulsions, O/W emulsions were prepared using a mixture of two PGFEs with different degrees of glycerol polymerization, that is, systems having different hydrophilic-lipophilic balance values.

Effect of polyols on membrane structures of liposomes: A study using small-angle X-ray scattering data and generalized indirect Fourier transformation.

This study aimed to evaluate the membrane structure of distearoylphosphatidylcholine (DSPC) liposomes dispersed in water containing various types of polyols with low molecular weight such as glycerin (Gly), 1,3-butandiol (BG), and propylene glycol (PG). To clarify the detailed membrane structure, generalized indirect Fourier transformation (GIFT) analysis, which provides information about the bilayer spacing, bilayer thickness, number of lamellar layers, and membrane flexibility, was applied to small-angle X-ray scattering (SAXS) data of the present system. The GIFT results showed that the bilayer thickness of the DSPC liposomes followed the order Gly>>BG>PG. In addition, the membrane flexibility estimated by the Caille parameter was in the order Gly>>BG>PG; this result was supported by the gel-liquid crystal phase transition temperature (Tc) obtained by differential scanning calorimetry (DSC). These results, together with the Raman spectra, suggest that BG and PG incorporated into the bilayers of DSPC liposomes result in the formation of an interdigitated lamellar structure.

Molecular characterization of SARS-CoV-2 detected in Tokyo, Japan during five waves: Identification of the amino acid substitutions associated with transmissibility and severity.

Many variants of SARS-CoV-2 have emerged around the world. It is therefore important to understand its global viral evolution and the corresponding mutations associated with transmissibility and severity. In this study, we analyzed 112 whole genome sequences of SARS-CoV-2 collected from patients at Juntendo University Hospital in Tokyo and the genome data from entire Japan deposited in Global Initiative on Sharing Avian Influenza Data (GISAID) to examine the relationship of amino acid changes with the transmissibility and the severity of each strain/lineage. We identified 12 lineages, including B.1.1.284, B.1.1.214, R.1, AY.29, and AY.29.1, which were prevalent specifically in Japan. B.1.1.284 was most frequently detected in the second wave, but B.1.1.214 became the predominant lineage in the third wave, indicating that B.1.1.214 has a higher transmissibility than B.1.1.284. The most prevalent lineage during the fourth and fifth wave was B.1.1.7 and AY.29, respectively. In regard to the severity of identified lineages, B.1.1.214 was significantly lower than the reference lineage, B.1.1.284. Analysis of the genome sequence and other traits of each lineage/strain revealed the mutations in S, N, and NSPs that increase the transmissibility and/or severity. These mutations include S: M153T, N: P151L, NSP3: S543P, NSP5: P108S, and NSP12: A423V in B.1.1.284; S: W152L and E484K in R.1; S: H69del, V70del, and N501Y in the Alpha strain; S: L452R, T478K, and P681R in the Delta strain. Furthermore, it is suggested that the transmissibility of B.1.1.214 could be enhanced by the mutations N: M234I, NSP14: P43L, and NSP16: R287I. To address the issue of the virus evolution, it is necessary to continuously monitor the genomes of SARS-CoV-2 and analyze the effects of mutations for developing vaccines and antiviral drugs effective against SARS-CoV-2 variants.

Photochemical control of molecular assembly formation in a catanionic surfactant system.

Photochemical control of vesicle disintegration and reformation in aqueous solution was examined using a mixture of 4-butylazobenzene-4'-(oxyethyl)trimethylammonium bromide (AZTMA) as the photoresponsive cationic surfactant and sodium dodecylbenzenesulfonate (SDBS) as the anionic surfactant. Spontaneous vesicle formation was found in a wide-ranging composition of the trans-AZTMA/SDBS system. AZTMA molecules constituting vesicles underwent reversible trans-cis photoisomerization when irradiated with ultraviolet and visible light. Transmission electron microscopy observations using the freeze-fracture technique (FF-TEM) showed that UV light irradiation caused the vesicles to disintegrate into coarse aggregates and visible light irradiation stimulated the reformation of vesicles (normal control). A detailed investigation of the phase state and the effects of UV and visible light irradiation on the AZTMA/SDBS system with the use of electroconductivity, dynamic/static light scattering, and surface tension measurements and FF-TEM observations revealed that in the AZTMA-rich composition (AZTMA/SDBS 9:1) a micellar solution before light irradiation became a vesicular solution after UV light irradiation and visible light irradiation allowed the return to a micellar solution (reverse control). Thus, we could photochemically control the disintegration (normal control) and reformation (reverse control) of vesicles in the same system.

[Aortic regurgitation due to quadricuspid aortic valve; report of a case].

A 66-year-old man was referred to our hospital for surgical treatment for aortic regurgitation. Transthoracic echocardiography revealed the diagnosis of aortic regurgitation due to quadricuspid aortic valve. During operation, we confirmed that the aortic valve consisted of 4 leaflets with almost same size (Hurwitz and Roberts classification type A). We performed valve replacement because each leaflet has degenerative change. The patient's postoperative course was uneventful and discharged the hospital without complications. Congenital quadricuspid aortic valves are rare, and patients with this disease are frequently operated because of aortic regurgitation. Presently, common operative procedure is aortic valve replacement, although in the future valvuloplasty should be investigated.