Splicing factors control C. elegans behavioural learning in a single neuron by producing DAF-2c receptor

Alternative splicing generates protein diversity essential for neuronal properties. However, the precise mechanisms underlying this process and its relevance to physiological and behavioural functions are poorly understood. To address these issues, we focused on a cassette exon of the Caenorhabditis elegans insulin receptor gene daf-2, whose proper variant expression in the taste receptor neuron ASER is critical for taste-avoidance learning. We show that inclusion of daf-2 exon 11.5 is restricted to specific neuron types, including ASER, and is controlled by a combinatorial action of evolutionarily conserved alternative splicing factors, RBFOX, CELF and PTB families of proteins. Mutations of these factors cause a learning defect, and this defect is relieved by DAF-2c (exon 11.5þ) isoform expression only in a single neuron ASER. Our results provide evidence that alternative splicing regulation of a single critical gene in a single critical neuron is essential for learning ability in an organism.UTokyo Research掲載「飢餓の記憶の形成に必要な分子が作られるしくみ」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/production-of-a-molecule-for-memory-of-salt-concentration.htmlUTokyo Research "Production of a molecule for memory of salt concentration" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/production-of-a-molecule-for-memory-of-salt-concentration.htm

A Sexually Conditioned Switch of Chemosensory Behavior in C. elegans

In sexually reproducing animals, mating is essential for transmitting genetic information to the next generation and therefore animals have evolved mechanisms for optimizing the chance of successful mate location. In the soil nematode C. elegans, males approach hermaphrodites via the ascaroside pheromones, recognize hermaphrodites when their tails contact the hermaphrodites' body, and eventually mate with them. These processes are mediated by sensory signals specialized for sexual communication, but other mechanisms may also be used to optimize mate location. Here we describe associative learning whereby males use sodium chloride as a cue for hermaphrodite location. Both males and hermaphrodites normally avoid sodium chloride after associative conditioning with salt and starvation. However, we found that males become attracted to sodium chloride after conditioning with salt and starvation if hermaphrodites are present during conditioning. For this conditioning, which we call sexual conditioning, hermaphrodites are detected by males through pheromonal signaling and additional cue(s). Sex transformation experiments suggest that neuronal sex of males is essential for sexual conditioning. Altogether, these results suggest that C. elegans males integrate environmental, internal and social signals to determine the optimal strategy for mate location

Suitable binder for Li‑ion battery anode produced from rice husk

Rice husk (RH) is a globally abundant and sustainable bioresource composed of lignocellulose and　inorganic components, the majority of which consist of silicon oxides (approximately 20% w/w in　dried RH). In this work, a RH-derived C/SiOx composite (RHC) was prepared by carbonization at　1000 °C for use in Li-ion battery anodes. To find a suitable binder for RHC, the RHC-based electrodes　were fabricated using two different contemporary aqueous binders: polyacrylic acid (PAA) and a　combination of carboxymethyl cellulose and styrene butadiene rubber (CMC/SBR). The rate and　cycling performances of the RHC electrodes with respect to the insertion/extraction of Li ions were　evaluated in a half-cell configuration. The cell was shorted for 24 h to completely lithiate the RHC.　Impedance analysis was conducted to identify the source of the increase in the resistance of the　RHC electrodes. The RHC electrode fabricated using PAA exhibited higher specific capacity for Li-ion　extraction during the cycling test. The PAA binder strengthened the electrode and alleviated the　increase in electrode resistance caused by the formation of the interphase film. The high affinity of　PAA for SiOx　in RHC was responsible for the stabilization of the anodic performance of Li-ion batteries

Role of SiOx in rice-husk-derived anodes for Li-ion batteries

The present study investigated the role of SiOx in a rice-husk-derived C/SiOx anode on the rate and cycling performance of a Li-ion battery. C/SiOx active materials with different SiOx contents (45, 24, and 5 mass%) were prepared from rice husk by heat treatment and immersion in NaOH solution. The C and SiOx specific capacities were 375 and 475 mAh g(-1), respectively. A stable anodic operation was achieved by pre-lithiating the C/SiOx anode. Full-cells consisting of this anode and a Li(Ni-0.5,Co-0.2,Mn-0.3) O-2 cathode displayed high initial Coulombic efficiency (similar to 85%) and high discharge specific capacity, indicating the maximum performance of the cathode (similar to 150 mAh g(-1)). At increased current density, the higher the SiOx content, the higher the specific capacity retention, suggesting that the time response of the reversible reaction of SiOx with Li ions is faster than that of the C component. The full-cell with the highest SiOx content exhibited the largest decrease in cell specific capacity during the cycle test. The structural decay caused by the volume expansion of SiOx during Li-ion uptake and release degraded the cycling performance. Based on its high production yield and electrochemical benefits, degree of cycling performance degradation, and disadvantages of its removal, SiOx is preferably retained for Li-ion battery anode applications

Effects of Excessive Prelithiation on Full-Cell Performance of Li-Ion Batteries with a Hard-Carbon/Nanosized-Si Composite Anode

The effects of excessive prelithiation on the full-cell performance of Li-ion batteries (LIBs) with a hard-carbon/nanosized-Si (HC/N-Si) composite anode were investigated; HC and N-Si simply mixed at mass ratios of 9:1 and 8:2 were analyzed. CR2032-type half- and full-cells were assembled to evaluate the electrochemical LIB anode behavior. The galvanostatic measurements of half-cell configurations revealed that the composite anode with an 8:2 HC/N-Si mass ratio exhibited a high capacity (531 mAh g(-1)) at 0.1 C and superior current-rate dependence (rate performance) at 0.1-10 C. To evaluate the practical LIB anode performance, the optimally performing composite anode was used in the full cell. Prior to full-cell assembly, the composite anodes were prelithiated via electrochemical Li doping at different cutoff anodic specific capacities (200-600 mAh g(-1)). The composite anode was paired with a LiNi0.5Co0.2Mn0.3O2 cathode to construct full-cells, the performance of which was evaluated by conducting sequential rate and cycling performance tests. Prelithiation affected only the cycling performance, without affecting the rate performance. Excellent capacity retention was observed in the full-cells with prelithiation conducted at cutoff anodic specific capacities greater than or equal to 500 mAh g(-1)

Effect of Ball Milling on the Electrochemical Performance of Activated Carbon with a Very High Specific Surface Area

Activated carbon (AC) with a very high specific surface area of >3000 m(2)g(-1) and a number of course particles (average size: 75 mu m) was pulverized by means of planetary ball milling under different conditions to find its greatest performances as the active material of an electric double-layer capacitor (EDLC) using a nonaqueous electrolyte. The variations in textural properties and particle morphology of the AC during the ball milling were investigated. The electrochemical performance (specific capacitance, rate and cyclic stabilities, and Ragone plot, both from gravimetric and volumetric viewpoints) was also evaluated for the ACs milled with different particle size distributions. A trade-off relation between the pulverization and the porosity maintenance of the AC was observed within the limited milling time. However, prolonged milling led to a degeneration of pores within the AC and a saturation of pulverization degree. The appropriate milling time provided the AC a high volumetric specific capacitance, as well as the greatest maintenance of both the gravimetric and volumetric specific capacitance. A high volumetric energy density of 6.6 Wh L-1 was attained at the high-power density of 1 kW L-1, which was a 35% increment compared with the nonmilled AC. The electrode densification (decreased interparticle gap) and the enhanced ion-transportation within the AC pores, which were attributed to the pulverization, were responsible for those excellent performances. It was also shown that excessive milling could degrade the EDLC performances because of the lowered micro- and meso-porosity and the excessive electrode densification to restrict the ion-transportation within the pores

Impact of Full Prelithiation of Si-Based Anodes on the Rate and Cycle Performance of Li-Ion Capacitors

The impact of full prelithiation on the rate and cycle performance of a Si-based Li-ion capacitor (LIC) was investigated. Full prelithiation of the anode was achieved by assembling a half cell with a 2 mu m-sized Si anode (0 V vs. Li/Li+) and Li metal. A three-electrode full cell (100% prelithiation) was assembled using an activated carbon (AC) cathode with a high specific surface area (3041 m(2)/g), fully prelithiated Si anode, and Li metal reference electrode. A three-electrode full cell (87% prelithiation) using a Si anode prelithiated with 87% Li ions was also assembled. Both cells displayed similar energy density levels at a lower power density (200 Wh/kg at <= 100 W/kg; based on the total mass of AC and Si). However, at a higher power density (1 kW/kg), the 100% prelithiation cell maintained a high energy density (180 Wh/kg), whereas that of the 87% prelithiation cell was significantly reduced (80 Wh/kg). During charge/discharge cycling at similar to 1 kW/kg, the energy density retention of the 100% prelithiation cell was higher than that of the 87% prelithiation cell. The larger irreversibility of the Si anode during the initial Li-ion uptake/release cycles confirmed that the simple full prelithiation process is essential for Si-based LIC cells

Efect of Ball Milling on the Electrochemical Performance of Activated Carbon with a Very High Specific Surface Area

Activated carbon (AC) with a very high specific surface area of >3000 m2 g-1 and a number　of course particles (average size: 75 μm) was pulverized by means of planetary ball milling under　di erent conditions to find its greatest performances as the active material of an electric double-layer　capacitor (EDLC) using a nonaqueous electrolyte. The variations in textural properties and particle　morphology of the AC during the ball milling were investigated. The electrochemical performance　(specific capacitance, rate and cyclic stabilities, and Ragone plot, both from gravimetric and volumetric　viewpoints) was also evaluated for the ACs milled with di erent particle size distributions. A trade-o 　relation between the pulverization and the porosity maintenance of the AC was observed within the　limited milling time. However, prolonged milling led to a degeneration of pores within the AC and a　saturation of pulverization degree. The appropriate milling time provided the AC a high volumetric　specific capacitance, as well as the greatest maintenance of both the gravimetric and volumetric　specific capacitance. A high volumetric energy density of 6.6 Wh L-1 was attained at the high-power　density of 1 kW L-1, which was a 35% increment compared with the nonmilled AC. The electrode　densification (decreased interparticle gap) and the enhanced ion-transportation within the AC pores,　which were attributed to the pulverization, were responsible for those excellent performances. It was　also shown that excessive milling could degrade the EDLC performances because of the lowered　micro- and meso-porosity and the excessive electrode densification to restrict the ion-transportation　within the pores

Misdiagnosis of Anterior Superior Pancreaticoduodenal Artery Aneurysm Rupture Likely Due to Segmental Arterial Mediolysis: A Case Report

An aneurysm of the abdominal internal organs is relatively rare. Recently, segmental arterial mediolysis (SAM) and median arcuate ligament syndrome (MALS) were identified as specific causes for aneurysms of the pancreaticoduodenal artery arcade. Herein, we report a ruptured anterior superior pancreaticoduodenal artery (ASPDA) aneurysm due to SAM that was misdiagnosed as acute pancreatitis. The patient was a 59-year-old male with acute, severe, and sharp pain in the upper abdomen. He was clinically diagnosed with acute pancreatitis based on abdominal computed tomography (CT). However, a follow-up CT scan revealed an aneurysm of the ASPDA. We therefore diagnosed this case as retroperitoneal hemorrhage due to aneurysm rupture, and we performed an angiogram and transcatheter arterial embolization to prevent aneurysm re-rupture. Based on a subsequent review of all the findings for this patient, we retrospectively determined the cause of the ASPDA aneurysm to be SAM. Such case reports are rare, and further accumulation of similar cases is necessary in the near future to establish proper diagnostic criteria and appropriate treatment protocols

Timing of therapeutic interventions against infection-triggered encephalopathy syndrome: a scoping review of the pediatric literature

Our goal was to conduct a scoping review of the literature on the treatment of infection-triggered encephalopathy syndrome/acute encephalopathy in children, focusing on treatment targets and treatment initiation timing. We performed literature searches using PubMed for articles reporting treatments of infection-triggered encephalopathy syndrome/acute encephalopathy. We included articles describing specific treatments for acute encephalopathy with control groups. For the purpose of searching new therapies only experimentally tried in the case series, we also included case series studies without control groups in this review, if the studies contained at least two cases with clear treatment goals. Therapies were classified based on their mechanisms of action into brain protection therapy, immunotherapy, and other therapies. We operationally categorized the timing of treatment initiation as T1 (6–12 h), T2 (12–24 h), T3 (24–48 h), and T4 (&gt;48 h) after the onset of seizures and/or impaired consciousness. Thirty articles were included in this review; no randomized control study was found. Eleven retrospective/historical cohort studies and five case–control studies included control groups with or without specific therapies or outcomes. The targeted conditions and treatment timing varied widely across studies. However, the following three points were suggested to be effective in multiple studies: (1) Careful seizure management and targeted temperature management within 12 h (T1) of onset of febrile seizure/prolonged impaired consciousness without multiple organ failure may reduce the development of acute encephalopathy with biphasic seizures and late reduced diffusion; (2) immunotherapy using corticosteroids, tocilizumab, or plasma exchange within 24 h (T1–T2) of onset of acute necrotizing encephalopathy may reduce sequelae; and (3) anakinra therapy and ketogenic diet demonstrate little evidence of neurologic sequelae reduction, but may reduce seizure frequency and allow for weaning from barbiturates, even when administered weeks (T4) after onset in children with febrile infection-related epilepsy syndrome. Although available studies have no solid evidence in the treatment of infection-triggered encephalopathy syndrome/acute encephalopathy, this scoping review lays the groundwork for future prospective clinical trials