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Proton conductors are attractive materials with a wide range of potential applications such as proton-conducting fuel cells (PCFCs). The conventional strategy to enhance the proton conductivity is acceptor doping into oxides without oxygen vacancies. However, the acceptor doping results in proton trapping near dopants, leading to the high apparent activation energy and low proton conductivity at intermediate and low temperatures. The hypothetical cubic perovskite BaScO 2.5 may have intrinsic oxygen vacancies without the acceptor doping. Herein, we report that the cubic perovskite-type BaSc 0.8 Mo 0.2 O 2.8 stabilized by Mo donor-doing into BaScO 2.5 exhibits high proton conductivity within the ‘Norby gap’ (e.g., 0.01 S cm −1 at 320 °C) and high chemical stability under oxidizing, reducing and CO 2 atmospheres. The high proton conductivity of BaSc 0.8 Mo 0.2 O 2.8 at intermediate and low temperatures is attributable to high proton concentration, high proton mobility due to reduced proton trapping, and three-dimensional proton diffusion in the cubic perovskite stabilized by the Mo-doping into BaScO 2.5 . The donor doping into the perovskite with disordered intrinsic oxygen vacancies would be a viable strategy towards high proton conductivity at intermediate and low temperatures. Proton conductors are promising materials used in various applications such as fuel cells. Here, authors report high proton conductivity due to the reduction of proton trapping of donor Mo 6+ doped BaScO 2.5 with disordered intrinsic oxygen vacancies.

The relationship between different microstructures and hydrogen trapping states of cold-drawn pearlitic (CD-P) steel, medium-carbon martensitic (MC-M) steel, and high-carbon martensitic (HC-M) steel was studied based on the hydrogen desorption profile, activation energy of hydrogen desorption (Ea), and hydrogen release behavior at room temperature by means of thermal desorption analysis (TDA). The TDA results revealed that hydrogen in CD-P and HC-M was present as both Peak 1H and Peak 2H, but only as Peak 1H in MC-M. Hydrogen release behavior indicated that Peak 1H for all three types of steel was diffusible (Ea ≤ 34 kJ/mol). For CD-P, Peak 2H was non-diffusible (Ea = 62 kJ/mol), but diffusible for HC-M (Ea = 43 kJ/mol). TDA results combined with SEM and/or TEM observation and XRD analysis clarified that the former hydrogen was desorbed from strained incoherent α/θ interfaces in a detrapping-controlled process. The latter hydrogen was desorbed via trapping sites involved in retained austenite in a diffusion-controlled process. It is essential to judge hydrogen trapping states as either diffusible or non-diffusible by analyzing not only hydrogen desorption profiles but also hydrogen release behaviors and Ea values, taking into account microstructure characteristics related to hydrogen trapping and diffusion processes.

BackgroundEndoscopic management of hepaticojejunostomy anastomotic strictures is technically demanding due to surgically altered anatomy. The promise of double-balloon endoscope-assisted endoscopic retrograde cholangiopancreatography (DB-ERCP) has been reported in this setting. No large study has examined long-term outcomes of this new treatment modality and predictive factors for the stricture resolution.MethodsWe included 102 patients who received DB-ERCP for a hepaticojejunostomy anastomotic stricture between 2008 and 2018. Balloon dilation was performed as a first-line treatment, and plastic stent(s) were placed for refractory cases. Potential predictive factors for the stricture resolution were examined using multivariable logistic regression analyses.ResultsDB-ERCP was technically successful in 91 patients (89.2%). Overall, stricture resolution was achieved in 70 patients (76.9%) with a median follow-up period of 30.9 months (range 1–118.5 months). Among 64 patients (71.9%) who underwent successful re-canalization via balloon dilation, anastomotic stricture recurred in 22 patients (34.4%). In cases with refractory or recurrent stricture after balloon dilation, 20 patients (52.6%) underwent stricture resolution via plastic stent placement, and the recurrence was observed in two patients (10%). Post-operative time to DB-ERCP of > 12 months and the scar-like appearance around the anastomosis were associated with a higher rate of stricture resolution (odds ratios, 5.59 [95% CI 1.69–18.5] and 5.22 [95% CI 1.29–21.1], respectively).ConclusionsTreatment of hepaticojejunostomy anastomotic strictures via DB-ERCP was technically feasible, providing a reasonably high rate of stricture resolution. Alternative treatment should be explored for refractory cases.

BackgroundIn patients with unresectable hilar malignant biliary obstruction (MBO), bilateral metal stent placement is recommended. However, treatment selection between partially stent-in-stent (SIS) and side-by-side (SBS) methods is still controversial.StudyClinical outcomes of bilateral metal stent placement by SBS and SIS methods for hilar MBO were retrospectively studied in four Japanese centers. While large-cell-type uncovered metal stents were placed above the papilla in SIS, braided-type uncovered metal stents were placed across the papilla in SBS.ResultsA total of 64 patients with hilar MBO (40 SIS and 24 SBS) were included in the analysis. Technical success rate was 100% in SIS and 96% in SBS. Functional success rate was 93% in SIS and 96% in SBS. Early adverse event rates were higher in SBS (46%) than in SIS (23%), though not statistically significant (P = 0.09). Post-procedure pancreatitis was exclusively observed in SBS group (29%). Recurrent biliary obstruction rates were 48% and 43%, and the median time to recurrent biliary obstruction was 169 and 205 days in SIS and SBS, respectively.ConclusionsOther than a trend to higher adverse event rates including post-procedure pancreatitis in SBS, clinical outcomes of SIS and SBS methods were comparable in patients with unresectable hilar MBO.

An attempt was made to separate and identify hydrogen peaks desorbed from plastic-strained, hydrogen-enhanced lattice defects from among various trapping sites in tempered martensitic steel showing quasi-cleavage fracture using thermal desorption spectroscopy from a low temperature (L-TDS) and positron annihilation spectroscopy (PAS). The amount of the lattice defects beneath the quasi-cleavage fracture surface was measured by L-TDS. The L-TDS results made it possible to separate two peaks, namely that of the original desorption and also that of new desorption from the steel specimens due to the application of plastic strain in the presence of hydrogen. The PAS results revealed that the new desorption obtained by L-TDS corresponded to vacancy-type defects. Hydrogen and plastic strain noticeably enhanced lattice defects formed within 1.5 mm from the fracture surface, where the average concentration of vacancy-type defects reached approximately 10−5 order in terms of atomic ratio. These results indicate that the accumulation of excess vacancy-type defects enhanced by hydrogen in the local region can lead to nanovoid nucleation and coalescence in plastic deformation, resulting in quasi-cleavage fracture of tempered martensitic steel.

Properly patterned deposition of cell wall polymers is prerequisite for the morphogenesis of plant cells. A cortical microtubule array guides the two-dimensional pattern of cell wall deposition. Yet, the mechanism underlying the three-dimensional patterning of cell wall deposition is poorly understood. In metaxylem vessels, cell wall arches are formed over numerous pit membranes, forming highly organized three-dimensional cell wall structures. Here, we show that the microtubule-associated proteins, MAP70-5 and MAP70-1, regulate arch development. The map70-1 map70-5 plants formed oblique arches in an abnormal orientation in pits. Microtubules fit the aperture of developing arches in wild-type cells, whereas microtubules in map70-1 map70-5 cells extended over the boundaries of pit arches. MAP70 caused the bending and bundling of microtubules. These results suggest that MAP70 confines microtubules within the pit apertures by altering the physical properties of microtubules, thereby directing the growth of pit arches in the proper orientation. This study provides clues to understanding how plants develop three-dimensional structure of cell walls. In plant metaxylem, three-dimensional cell wall arches are formed over pit membranes. Here, the authors show that the microtubule-associated proteins, MAP70-5 and MAP70-1, confine microtubules within the pit aperture and direct growth of pit arches in the proper orientation.

Somatosensory training, which involves repetitive somatosensory stimulation, has been employed to enhance somatosensory performance by modulating excitability in the primary somatosensory cortex. This process, known as perceptual learning, can benefit stroke patients with somatosensory deficits. However, its effectiveness in both healthy individuals and stroke patients has not been thoroughly investigated. This systematic review and meta-analysis aimed to evaluate the effectiveness of somatosensory training in these groups. However, no eligible data on stroke patients were identified, excluding them from the analysis. In healthy participants, somatosensory training improved performance in 61.2% datasets, but this effect was observed only at the stimulated site. Additionally, it increased early somatosensory-evoked potential amplitudes in 76.9% of datasets at the stimulated site, with no effect on the non-stimulated site. Despite these moderate improvements, the risk of bias assessment revealed methodological concerns including randomization process, proper control conditions, blinding information, and missing data. The meta-analysis focused on the impact of somatosensory training on tactile two-point discrimination (TPD) in various factors, including different age groups, stimulus durations, stimulus frequencies, and stimulus types. A marked reduction in TPD threshold was observed at the stimulated finger post-training compared to pre-training, though there was a noticeable heterogeneity across studies. In contrast, no significant changes occurred at the non-stimulated fingers, and the subgroup analysis found no specific factors influencing TPD improvements. Although somatosensory training benefits healthy individuals, the variability and methodological concerns highlight the need for further high-quality research to optimize its use in treating somatosensory deficits in stroke patients.

Cardiac ryanodine receptor (RyR2) is a large Ca 2+ release channel in the sarcoplasmic reticulum and indispensable for excitation-contraction coupling in the heart. RyR2 is activated by Ca 2+ and RyR2 mutations are implicated in severe arrhythmogenic diseases. Yet, the structural basis underlying channel opening and how mutations affect the channel remains unknown. Here, we address the gating mechanism of RyR2 by combining high-resolution structures determined by cryo-electron microscopy with quantitative functional analysis of channels carrying various mutations in specific residues. We demonstrated two fundamental mechanisms for channel gating: interactions close to the channel pore stabilize the channel to prevent hyperactivity and a series of interactions in the surrounding regions is necessary for channel opening upon Ca 2+ binding. Mutations at the residues involved in the former and the latter mechanisms cause gain-of-function and loss-of-function, respectively. Our results reveal gating mechanisms of the RyR2 channel and alterations by pathogenic mutations at the atomic level. Ryanodine receptor 2 (RyR2) is a Ca 2+ release channel essential for cardiac excitation-contraction coupling. Here, the authors use structural and functional analysis to reveal RyR2 gating mechanism and its alterations by pathogenic mutations.

•We identified key processes underlying tactile orientation processing.•Alpha rs-FC between S1–SPL and S1–POS plays a role in this processing.•S1/S2-derived inhibitory circuits do not contribute to this processing. Grating orientation discrimination (GOD) is commonly used to assess somatosensory spatial processing. It allows discrimination between parallel and orthogonal orientations of tactile stimuli applied to the fingertip. Despite its widespread application, the underlying mechanisms of GOD, particularly the role of cortico-cortical interactions and local brain activity in this process, remain elusive. Therefore, we aimed to investigate how a specific cortico-cortical network and inhibitory circuits within the primary somatosensory cortex (S1) and secondary somatosensory cortex (S2) contribute to GOD. In total, 51 healthy young adults were included in our study. We recorded resting-state magnetoencephalography (MEG) and somatosensory-evoked magnetic field (SEF) in participants with open eyes. We converted the data into a source space based on individual structural magnetic resonance imaging. Next, we estimated S1- and S2-seed resting-state functional connectivity (rs-FC) at the alpha and beta bands through resting-state MEG using the amplitude envelope correlation method across the entire brain (i.e., S1/S2-seeds × 15,000 vertices × two frequencies). We assessed the inhibitory response in the S1 and S2 from SEFs using a paired-pulse paradigm. We automatically measured the GOD task in parallel and orthogonal orientations to the index finger, applying various groove widths with a custom-made device. We observed a specific association between the GOD threshold (all P < 0.048) and the alpha rs-FC in the S1–superior parietal lobule and S1–adjacent to the parieto-occipital sulcus (i.e., lower rs-FC values corresponded to higher performance). In contrast, no association was observed between the local responses and the threshold. The results of this study underpin the significance of specific cortico-cortical networks in recognizing variations in tactile stimuli. [Display omitted]

BackgroundEndoscopic ultrasonography (EUS)-guided interventions are often performed using a single guidewire (SGW), but there are a few reports on the use of double guidewire (DGW) technique to facilitate multiple drainage placement during EUS-guided drainage of pancreatic fluid collections. This DGW technique may have advantages other than multiple drainage placement during EUS-guided interventions such as scope stabilization, support for stone extraction and device insertion.MethodsConsecutive patients who underwent EUS-guided interventions between Feb 2012 and Apr 2019 were retrospectively reviewed. The rate and reasons of DGW technique, and clinical outcomes were evaluated. DGW technique was performed, using an uneven double lumen cannula (UDLC), which facilitates insertion of 0.025-in. and 0.035-in. guidewires.ResultsA total of 249 EUS-guided interventions were analyzed, and DGW technique was utilized primarily in 65 cases (25.7%) and as a salvage after failed SGW technique in 18 cases (7.1%). The reasons for DGW technique were 60 multiple drainage placement, 10 scope stabilization, 7 device insertion, 5 safety guidewire, and 4 antegrade stone removal. Insertion of UDLC and DGW was successful in 100%. Technical success rate of preplanned interventions was 92.7% (96.9% in primary DGW and 77.8% in salvage DGW technique). Adverse events were observed in 19.5% after DGW but were not related to DGW technique.ConclusionsDGW technique using UDLC during EUS-guided interventions was technically feasible and safe. In addition to multiple drainage insertion, it can potentially support complex EUS-guided interventions.