Anthranilamide-protected vinylboronic acid: rational monomer design for improved polymerization/transformation ability providing access to conventionally inaccessible copolymers

We have studied several protecting groups for vinylboronic-acid derivatives as monomers in radical polymerizations with the objective to improve the polymerization ability and C–B bond-cleaving post-transformation performance. Anthranilamide (aam)-protected vinylboronic acid (VBaam) exhibited experimentally a relatively high polymerization activity, which was theoretically corroborated by density functional theory (DFT) calculations that revealed a peculiar effect of the interaction between the aam groups on the polymerization behavior. The VBaam units in the copolymers can subsequently be transformed into vinyl alcohols or into ethylene units through C–B-bond-cleaving side-chain replacement, which affords valuable copolymers such as poly(vinyl alcohol-co-styrene), poly(ethylene-co-styrene), and poly(ethylene-co-acrylate)

Optical and radiographical characterization of silica aerogel for Cherenkov radiator

We present optical and X-ray radiographical characterization of silica aerogels with refractive index from 1.05 to 1.07 for a Cherenkov radiator. A novel pin-drying method enables us to produce highly transparent hydrophobic aerogels with high refractive index by shrinking wet-gels. In order to investigate the uniformity in the density (i.e., refractive index) of an individual aerogel monolith, we use the laser Fraunhofer method, an X-ray absorption technique, and Cherenkov imaging by a ring imaging Cherenkov detector in a beam test. We observed an increase in density at the edge of the aerogel tiles, produced by pin-drying.Comment: To be published in IEEE Trans. Nucl. Sci., 7 pages, 9 figures, 1 tabl

Community structure and vertical distribution of chaetognaths in the Celebes and Sulu Seas

Chaetognath community structure, vertical distribution and migration patterns were investigated in two marginal basins-the Celebes and Sulu Seas. The two seas are part of an island arc located in the southeastern Asia region of the western equatorial Pacific Ocean. The Sulu Sea had higher species diversity (Shannon Index, H\u27) and higher overall chaetognath abundance than the Celebes Sea. Twenty-two species from 4 genera were collected from the Sulu Sea and 19 species from 4 genera were collected from the Celebes Sea. Three species were collected exclusively in the Sulu Sea: Sagitta bipunctata, Sagitta nagae and an unidentified Sagitta species. Sagitta enflata was the numerically dominant species at both locations. Species diversity in the Celebes Sea was fairly even between the surface and 1000m. However, in the Sulu Sea substantial drops in diversity occurred at 175-200m-below the oxycline, thermocline and halocline-as well as at 900-1000m. The drop at 175-200m and 900-1000m was largely due to the numerical dominance of the species Sagitta decipiens and Sagitta macrocephala, respectively. In the Celebes Sea only, a large portion of the overall chaetognath population migrated downwards during the day into the 125-200m layer. Cluster analysis using Ward\u27s method, along with weighted mean depth values, revealed that this migration was largely attributable to the species Sagitta pacifica, Sagitta ferox-robusta, Sagitta neglecta and Pterosagitta draco. A similar migration of the overall population was blocked in the Sulu Sea-apparently by the oxycline. It seems the group of migrating chaetognaths in the Celebes Sea prevented the numerical dominance of S. decipiens at the lower edge of the epipelagic region, possibly through competition, and consequently prevented the same drop in diversity (H\u27) at 175-200m as was recorded in the Sulu Sea

Quasi-direct Cu–Si3N4 bonding using multi-layered active metal deposition for power-module substrate

Tatsumi H., Moon S., Takahashi M., et al. Quasi-direct Cu–Si3N4 bonding using multi-layered active metal deposition for power-module substrate. Materials and Design 238, 112637 (2024); https://doi.org/10.1016/j.matdes.2024.112637.The advancement of power modules demands more reliable insulating circuit substrates. Traditional substrates, comprising Cu and Si3N4, are produced using active metal brazing (AMB). However, AMB substrates have reliability concerns owing to electrochemical migration and void formation from brazing filler metals. This study introduces a quasi-direct Cu–Si3N4 bonding technique using a Ti/Al bilayer active metal deposition at the bonding interface. A sputtered Ti/Al bilayer was formed on the Si3N4 surface, then heated and pressurized the sputtered Si3N4 substrate with Cu sheets in vacuum to bond each other without voids or delamination. The Ti/Al layers reacted with Si3N4 and Cu, forming a 300 nm intermediate layer. TEM observations show this layer contains segregated Ti–N and Cu–Al phases, with a good lattice match to Si3N4 and Cu–Al. Temperature-cycling tests on the Cu/Si3N4/Cu substrate revealed delamination caused by increased tensile stress at the periphery of the bonding area due to asymmetrical Cu patterns. This novel quasi-direct Cu–Si3N4 bonding technique addresses issues of electrochemical migration and void formation seen in AMB substrates, offering a reliable bonding interface for power electronic substrates

Joint Degradation in a Monkey Model of Collagen-Induced Arthritis: Role of Cathepsin K Based on Biochemical Markers and Histological Evaluation

The role of cathepsin K in joint degradation in a model of collagen-induced arthritis (CIA) in cynomolgus monkey was examined using biochemical markers and histology. Joint swelling, urinary C-telopeptide of type II collagen (CTX-II), deoxypyridinoline (DPD), and N- and C-telopeptides of type I collagen (NTX and CTX-I, resp.) were analyzed. Immunohistochemistry of type II collagen, cathepsin K, and CTX-II were performed using joints. Joint swelling reached peak on day 42 and continued at this level. The CTX-II level peaked on day 28 and declined thereafter, while CTX-I, NTX, and DPD reached plateau on day 43. Joint swelling was positively correlated with CTX-II increases on days 20 and 42/43, with increases in CTX-I and NTX/Cr on days 42/43 and 84, and with DPD increases throughout the study period. Intense cathepsin K staining was observed in osteoclasts and in articular cartilage and synovial tissue in arthritic joints. CTX-II was present in the superficial layer of articular cartilage in CIA monkeys. Evidence from biochemical markers suggests that matrix degradation in the CIA model starts with degradation of cartilage, rather than bone resorption. Cathepsin K expressed in osteoclasts, articular cartilage, and synovial tissue may contribute to degradation of cartilage

Rare Influenza A (H3N2) Variants with Reduced Sensitivity to Antiviral Drugs

In 2007 and 2008 in Myanmar, we detected influenza viruses A (H3N2) that exhibited reduced sensitivity to both zanamivir and amantadine. These rare and naturally occurring viruses harbored a novel Q136K mutation in neuraminidase and S31N mutation in M2

Synchronous neuroendocrine tumors in both the pancreas and ileum: A case report

AbstractIntroductionAlthough it is well-known that in multiple endocrine neoplasia type 1 (MEN 1) disease, multiple endocrine lesions frequently occur, synchronous or metachronous neuroendocrine tumors (NETs) in non-MEN 1 patients are extremely rare.Presentation of caseAn asymptomatic 72-year-old woman with an ileal NET was referred to our hospital. Abdominal computed tomography revealed another circular tumor within the pancreatic head. She was classified as a non-MEN 1 patient. An operative procedure was performed with a preoperative diagnosis of synchronous NET, which was confirmed by pathological examination.DiscussionBoth morphologic and immunophenotypic findings were different between in the ileum and pancreas. Therefore, it was reasonable to consider that both tumors were primary tumors. The synchronous occurrence of these tumors is unusual, and it may be considered as a chance occurrence.ConclusionWe here report the first case of synchronous pancreatic NET and ileal NET in a non-MEN 1 patient