Absolute local conformation of poly(methyl methacrylate) chains adsorbed on a quartz surface.

Polymer chains at a buried interface with an inorganic solid play a critical role in the performance of polymer nanocomposites and adhesives. Sum frequency generation (SFG) vibrational spectroscopy with a sub-nanometer depth resolution provides valuable information regarding the orientation angle of functional groups at interfaces. However, in the case of conventional SFG, since the signal intensity is proportional to the square of the second-order nonlinear optical susceptibility and thereby loses phase information, it cannot be unambiguously determined whether the functional groups face upward or downward. This problem can be solved by phase-sensitive SFG (ps-SFG). We here applied ps-SFG to poly(methyl methacrylate) (PMMA) chains in direct contact with a quartz surface, shedding light on the local conformation of chains adsorbed onto the solid surface. The measurements made it possible to determine the absolute orientation of the ester methyl groups of PMMA, which were oriented toward the quartz interface. Combining ps-SFG with all-atomistic molecular dynamics simulation, the distribution of the local conformation and the driving force are also discussed.

Effect of problem-based learning tutor seniority on medical students' emotions: an equivalence study.

BACKGROUND: The effectiveness of peer learning has been recognized and discussed by many scholars, and implemented in the formal curriculums of medical schools internationally. However, there is a general dearth of studies in measuring the objective outcomes in learning. METHODS: We investigated the objective effect of near-peer learning on tutee's emotions and its equivalence within the formal curriculum of a clinical reasoning Problem Based Learning session in a Japanese medical school. Fourth-year medical students were assigned to the group tutored by 6th-year students or by faculties. The positive activating emotion, positive deactivating emotion, negative activating emotion, negative deactivating emotion, Neutral emotion were measured using the Japanese version of the Medical Emotion Scale (J-MES), and self-efficacy scores were also assessed. We calculated the mean differences of these variables between the faculty and the peer tutor groups and were statistically analyzed the equivalence of these scores. The equivalence margin was defined as a score of 0.4 for J-MES and 10.0 for the self-efficacy score, respectively. RESULTS: Of the 143 eligible participant students, 90 were allocated to the peer tutor group and 53 were allocated to the faculty group. There was no significant difference between the groups. The 95% confidence interval of the mean score difference for positive activating emotions (-0.22 to 0.15), positive deactivating emotions (-0.35 to 0.18), negative activating emotions (-0.20 to 0.22), negative deactivating emotions (-0.20 to 0.23), and self-efficacy (-6.83 to 5.04) were withing the predetermined equivalence margins for emotion scores, meaning that equivalence was confirmed for these variables. CONCLUSIONS: Emotional outcomes were equivalent between near-peer PBL sessions and faculty-led sessions. This comparative measurement of the emotional outcomes in near-peer learning contributes to understanding PBL in the field of medical education.

Properties of INDETERMINATE DOMAIN Proteins from Physcomitrium patens: DNA-Binding, Interaction with GRAS Proteins, and Transcriptional Activity.

INDETERMINATE DOMAIN (IDD) proteins are plant-specific transcription factors that interact with GRAS proteins, such as DELLA and SHORT ROOT (SHR), to regulate target genes. The combination of IDD and DELLA proteins regulates genes involved in gibberellic acid (GA) synthesis and GA signaling, whereas the combination of IDD with the complex of SHR and SCARECROW, another GRAS protein, regulates genes involved in root tissue formation. Previous bioinformatic research identified seven IDDs, two DELLA, and two SHR genes in Physcomitrium patens, a model organism for non-vascular plants (bryophytes), which lack a GA signaling pathway and roots. In this study, DNA-binding properties and protein-protein interaction of IDDs from P. patens (PpIDD) were analyzed. Our results showed that the DNA-binding properties of PpIDDs were largely conserved between moss and seed plants. Four PpIDDs showed interaction with Arabidopsis DELLA (AtDELLA) proteins but not with PpDELLAs, and one PpIDD showed interaction with PpSHR but not with AtSHR. Moreover, AtIDD10 (JACKDAW) interacted with PpSHR but not with PpDELLAs. Our results indicate that DELLA proteins have modified their structure to interact with IDD proteins during evolution from moss lineage to seed plants, whereas the interaction of IDD and SHR was already present in moss lineage.

Local orientation of chains at crystal/amorphous interfaces buried in isotactic polypropylene thin films.

A better understanding of the aggregation states of polymer chains in thin films is of pivotal importance for developing thin film polymer devices in addition to its inherent scientific interest. Here we report the preferential orientation of the crystalline lamellae for isotactic polypropylene (iPP) in spin-coated films by grazing incidence of wide-angle X-ray diffraction in conjunction with sum frequency generation vibrational spectroscopy, which provides information on the local conformation of chains at crystal/amorphous interfaces buried in a thin film. The crystalline orientation of iPP, which formed cross-hatched lamellae induced by lamellar branching, altered from a mixture of edge-on and face-on mother lamellae to preferential face-on mother lamellae with decreasing thickness. The orientation of methyl groups at the crystal/amorphous interfaces in the interior region of the iPP films changed, accompanied by a change in the lamellar orientation.

Successful treatment of two Japanese ESRD cases with severe COVID-19 pneumonia.

Novel coronavirus disease 2019 (COVID-19) is a highly infectious and deadly disease, spreading worldwide. There are limited data about the clinical course of end-stage renal disease (ESRD) patients infected with COVID-19. However, previous cohort studies showed a high mortality rate of ESRD patients infected with COVID-19. We report here two Japanese ESRD patients confirmed with severe COVID-19 pneumonia. Case 1 was a 60-year-old man with ESRD due to diabetic nephropathy who were infected with COVID-19 and exhibited acute respiratory distress syndrome (ARDS) requiring mechanical ventilation and intensive care unit (ICU) admission. He was treated with tocilizumab and intravenous immunoglobulin (IVIG). After 6 days of treatment in ICU, he was extubated. Case 2 was a 68-year-old woman undergoing maintenance hemodialysis for 17 years who also exhibited ARDS due to COVID-19. Her clinical course resembles case 1. Our experience of these two cases indicates that anti-cytokine therapy might be effective for severe COVID-19 pneumonia in ESRD patients.

Surface Segregation of a Star-Shaped Polyhedral Oligomeric Silsesquioxane in a Polymer Matrix.

A simple way to control only the surface properties of polymer materials, without changing the bulk properties, has long been desired. The segregation behavior when a component with a tiny amount fed into the matrix is thermodynamically enriched at the surface is one of the candidate methods. This capability was examined herein by focusing on a star-shaped polyhedral oligomeric silsesquioxane (s-POSS), where the central POSS unit is tethered to eight isobutyl-substituted POSS cages as a surface modifier. X-ray photoelectron spectroscopy revealed that the surface of a film of poly(methyl methacrylate) (PMMA) was almost completely covered with POSS units by adding just 5 wt % s-POSS to it. The segregated POSS dramatically altered the physical properties such as molecular motion and the mechanical and dielectric responses at the surface of the PMMA film. These findings make it clear that s-POSS is an excellent surface modifier for glassy polymers.

Impact of the Solid Interface on Proton Conductivity in Nafion Thin Films.

Proton conductivity of polyelectrolytes in the interfacial region with a solid is key to the performance of polyelectrolyte-based fuel cells. The proton conductivity of Nafion thin films was examined as a function of the thickness along both directions, normal and parallel to the interface. Neutron reflectivity measurements revealed that a water-containing multilamellar structure was formed at the substrate interface. The presence of the interfacial layer, or the two-dimensional proton-conductive pathway, suppressed and enhanced the out-of-plane and in-plane proton conductivities, respectively. The method of proton conductivity in the interfacial region differed from that in the bulk, namely, the Grotthuss mechanism. Using laminated films, we conclude by showing that the proton conductivity in the Nafion thin film changes on the basis of the interface-to-volume ratio. This knowledge will be helpful for the design of devices containing polyelectrolytes with solid materials.

A new protein tyrosine phosphatase 1B inhibitory α-pyrone-type polyketide from Okinawan plant-associated Aspergillus sp. TMPU1623.

A new polyenyl-α-pyrone polyketide, aspopyrone A (1), was isolated from a culture broth of Okinawan plant-associated Aspergillus sp. TMPU1623 by solvent extraction, ODS column chromatography, and preparative HPLC (ODS). The structure of 1 was assigned based on NMR experiments. Compound 1 exhibited protein tyrosine phosphatase (PTP) 1B and T-cell PTP (TCPTP) inhibitory activities with IC50 values of 6.7 and 6.0 µM, respectively.

Effect of temperature post viral vector inoculation on the amount of hemagglutinin transiently expressed in Nicotiana benthamiana leaves.

Transient gene expression in whole plants by using viral vectors is promising as a rapid, mass production system for biopharmaceutical proteins. Recent studies have indicated that plant growth conditions such as air temperature markedly influence the accumulation levels of target proteins. Here, we investigated time course of the amount of recombinant hemagglutinin (HA), a vaccine antigen of influenza virus, in leaves of Nicotiana benthamiana plants grown at 20°C or 25°C post viral vector inoculation. The HA content per unit of leaf biomass increased and decreased from 4 to 6 days post inoculation at 20°C and 25°C, respectively, irrespective of the subcellular localization of HA. The overall HA contents were higher when HA was targeted to the endoplasmic reticulum (ER) rather than the apoplast. Necrosis of leaf tissues was specifically observed in plants inoculated with the ER-targeting vector and grown at 25°C. With the ER-targeting vector, the maximum HA contents at 20°C and 25°C were recorded at 6 and 4 days post inoculation, respectively, and were comparable to each other. HA contents thereafter decreased at both temperatures; the rate of reduction appeared faster at 25°C than at 20°C. From a practical point of view, our results indicate that the strategy of targeting HA to the ER, growing plants at a lower temperature of 20°C, and harvesting leaves at around a week after vector inoculation should be implemented to obtain a high HA yield stably and efficiently.

Production of ricinoleic acid-containing monoestolide triacylglycerides in an oleaginous diatom, Chaetoceros gracilis.

Ricinoleic acid (RA), a hydroxyl fatty acid, is suitable for medical and industrial uses and is produced in high-oil-accumulating organisms such as castor bean and the ergot fungus Claviceps. We report here the efficient production of RA in a transgenic diatom Chaetoceros gracilis expressing the fatty acid hydroxylase gene (CpFAH) from Claviceps purpurea. In transgenic C. gracilis, RA content increased at low temperatures, reaching 2.2 pg/cell when cultured for 7 d at 15 °C, without affecting cell growth, and was enhanced (3.3 pg/cell) by the co-expression of a palmitic acid-specific elongase gene. Most of the accumulated RA was linked with monoestolide triacylglycerol (ME TAG), in which one RA molecule was esterified to the α position of the glycerol backbone and was further esterified at its hydroxy group with a fatty acid or second RA moiety, or 1-OH TAG, in which RA was esterified to the glycerol backbone. Overall, 80% of RA was accumulated as ME TAGs. Furthermore, exogenous RA-methyl ester suppressed the growth of wild-type diatoms in a dose-dependent manner and was rapidly converted to ME TAG. These results suggest that C. gracilis masks the hydroxyl group and accumulates RA as the less-toxic ME TAG.

Docking-complex-independent alignment of Chlamydomonas outer dynein arms with 24-nm periodicity in vitro.

The docking complex is a molecular complex necessary for assembly of outer dynein arms (ODAs) on the axonemal doublet microtubules (DMTs) in cilia and flagella. The docking complex is hypothesized to be a 24-nm molecular ruler because ODAs align along the DMTs with 24-nm periodicity. In this study, we rigorously tested this hypothesis using structural and genetic methods. We found that the ODAs can bind to DMTs and porcine microtubules with 24-nm periodicities even in the absence of the docking complexin vitro Using cryo-electron tomography and structural labeling, we observed that the docking complex took an unexpectedly flexible conformation and did not lie along the length of DMTs. In the absence of docking complex, ODAs were released from the DMT at relatively low ionic strength conditions, suggesting that the docking complex strengthens the electrostatic interactions between the ODA and DMT. Based on these results, we conclude that the docking complex serves as a flexible stabilizer of the ODA rather than as a molecular ruler.

Structure and function of outer dynein arm intermediate and light chain complex.

The outer dynein arm (ODA) is a molecular complex that drives the beating motion of cilia/flagella. Chlamydomonas ODA is composed of three heavy chains (HCs), two ICs, and 11 light chains (LCs). Although the three-dimensional (3D) structure of the whole ODA complex has been investigated, the 3D configurations of the ICs and LCs are largely unknown. Here we identified the 3D positions of the two ICs and three LCs using cryo-electron tomography and structural labeling. We found that these ICs and LCs were all localized at the root of the outer-inner dynein (OID) linker, designated the ODA-Beak complex. Of interest, the coiled-coil domain of IC2 extended from the ODA-Beak to the outer surface of ODA. Furthermore, we investigated the molecular mechanisms of how the OID linker transmits signals to the ODA-Beak, by manipulating the interaction within the OID linker using a chemically induced dimerization system. We showed that the cross-linking of the OID linker strongly suppresses flagellar motility in vivo. These results suggest that the ICs and LCs of the ODA form the ODA-Beak, which may be involved in mechanosignaling from the OID linker to the HCs.

Predictors associated with the willingness to take human papilloma virus vaccination.

Human papilloma virus vaccine is considered to be the primary form of cervical cancer prevention. The objectives were (1) to determine knowledge about, and perception of human papilloma virus infection in relation to cervical cancer, (2) to explore the intention of the community to be vaccinated with human papilloma virus vaccine, and (3) to identify variables that could predict the likelihood of uptake of the vaccine. A cross-sectional survey was carried out in a semi-urban Town of Malaysia, using a pre-tested structured questionnaire. Summary statistics, Pearson chi-square test and a binary logistic regression were used for data analysis. A total of 232 respondents were interviewed. Overall, only a few had good knowledge related to human papilloma virus (14%) or vaccination (8%). Many had misconceptions that it could be transmitted through blood transfusion (57%). Sixty percent had intention to take vaccination. In the binary logistic model, willingness to take vaccination was significant with 'trusts that vaccination would be effective for prevention of cervical cancer' (P = 0.001), 'worries for themselves' (P < 0.001) or 'their family members' (P = 0.003) and 'being Indian ethnicity' (P = 0.024). The model could fairly predict the likelihood of uptake of the vaccine (Cox & Snell R(2) = .415; Nagelkerke R(2) = 0.561). Results indicate that intensive health education dispelling misconception and risk perception towards human papilloma virus infection and cervical cancer would be helpful to increase the acceptability of vaccination program.