Elastic constants of GaN grown by the oxide vapor phase epitaxy method

Fukuda H., Nagakubo A., Usami S., et al. Elastic constants of GaN grown by the oxide vapor phase epitaxy method. Applied Physics Express 17, 016501 (2024); https://doi.org/10.35848/1882-0786/ad0ba2.Oxide vapor phase epitaxy (OVPE) has attracted much attention as a highly efficient method for synthesizing high-quality bulk GaN crystals, but the mechanical properties of OVPE GaN have not been clarified. We measured the five independent elastic constants of the OVPE GaN by resonant ultrasound spectroscopy. The in-plane Young modulus E 1 and shear modulus C 66 of the OVPE GaN are smaller than those of the hydride vapor phase epitaxy GaN by 1.8% and 1.3%, respectively. These reductions agree with predictions by density functional theory calculations. We also calculated the Debye temperature, revealing that oxygen impurity decreases its magnitude

Preparation of Peptide Thioesters from Naturally Occurring Sequences Using Reaction Sequence Consisting of Regioselective S-Cyanylation and Hydrazinolysis

Vital roles of peptide/protein thioesters in protein chemistry, including chemical or semi synthesis of proteins, have encouraged studies on the development of methods for the preparation of such chemical units. Biochemical protocols using intein or sortase have proved to be useful in protein chemistry as methods suitable for naturally occurring sequences, including recombinant proteins. Although chemical protocols are potential options for thioester preparation, only a few are applicable to naturally occurring sequences, because standard chemical protocols require an artificial chemical device for producing thioesters. In this context, the chemical preparation of thioesters based on a reaction sequence consisting of regioselective S-cyanylation and hydrazinolysis was investigated. Regioselective S-cyanylation, which is required for cysteine-containing thioesters, was achieved with the aid of zinc-complex formation of a CCHH-type zinc-finger sequence. Free cysteine residues that are not involved in complex formation were selectively protected with a 6-nitroveratryl group followed by S-cyanylation of the zinc-binding cysteine. Hydrazinolysis of the resulting S-cyanopeptideand subsequent photo-removal of the 6-nitroveratryl group yielded the desired peptide hydrazide, which was then converted to the corresponding thioester. The generated thioester was successfully used in N–to–C-directed one-pot/sequential native chemical ligation using an N-sulfanylethylanilide peptide to give a 64-residue peptide toxin

Toll-like Receptor 7-Dependent Loss of B Cell Tolerance in Pathogenic Autoantibody Knockin Mice

SummarySystemic lupus erythematosus (SLE) is characterized by the production of autoantibodies that are frequently directed against nucleic acid-associated antigens. To better understand how B cells reactive with such antigens are regulated, we generated a model system in which heavy and light chain genes encoding 564 immunoglobulin have been targeted to the heavy and light chain loci of the nonautoimmune C57BL/6 mouse strain. This antibody recognizes RNA, single-stranded DNA, and nucleosomes. We show that B cells expressing this immunoglobulin were activated, producing class-switched autoantibody in vivo despite the apparently normal induction of anergy. This autoantibody production was largely dependent on Toll-like receptor 7 (TLR7). We further show that production of these autoantibodies was sufficient to cause kidney pathology in these mice. These results demonstrate that the particular threat of nucleic acid-containing autoantigens lies in their ability to bind both antigen receptor and TLR7

CA9 and PRELID2; hypoxia-responsive potential therapeutic targets for pancreatic ductal adenocarcinoma as per bioinformatics analyses

A strong hypoxic environment has been observed in pancreatic ductal adenocarcinoma (PDAC) cells, which contributes to drug resistance, tumor progression, and metastasis. Therefore, we performed bioinformatics analyses to investigate potential targets for the treatment of PDAC. To identify potential genes as effective PDAC treatment targets, we selected all genes whose expression level was related to worse overall survival (OS) in The Cancer Genome Atlas (TCGA) database and selected only the genes that matched with the genes upregulated due to hypoxia in pancreatic cancer cells in the dataset obtained from the Gene Expression Omnibus (GEO) database. Although the extracted 107 hypoxia-responsive genes included the genes that were slightly enriched in angiogenic factors, TCGA data analysis revealed that the expression level of endothelial cell (EC) markers did not affect OS. Finally, we selected CA9 and PRELID2 as potential targets for PDAC treatment and elucidated that a CA9 inhibitor, U-104, suppressed pancreatic cancer cell growth more effectively than 5-fluorouracil (5-FU) and PRELID2 siRNA treatment suppressed the cell growth stronger than CA9 siRNA treatment. Thus, we elucidated that specific inhibition of PRELID2 as well as CA9, extracted via exhaustive bioinformatic analyses of clinical datasets, could be a more effective strategy for PDAC treatment

Cryo-EM structure of a Ca2⁺-bound photosynthetic LH1-RC complex containing multiple αβ-polypeptides

The light-harvesting-reaction center complex (LH1-RC) from the purple phototrophic bacterium Thiorhodovibrio strain 970 exhibits an LH1 absorption maximum at 960nm, the most red-shifted absorption for any bacteriochlorophyll (BChl) a-containing species. Here we present a cryo-EM structure of the strain 970 LH1-RC complex at 2.82 angstrom resolution. The LH1 forms a closed ring structure composed of sixteen pairs of the αβ-polypeptides. Sixteen Ca ions are present in the LH1 C-terminal domain and are coordinated by residues from the αβ -polypeptides that are hydrogen-bonded to BChl a. The Ca2⁺-facilitated hydrogen-bonding network forms the structural basis of the unusual LH1 redshift. The structure also revealed the arrangement of multiple forms of α- and β -polypeptides in an individual LH1 ring. Such organization indicates a mechanism of interplay between the expression and assembly of the LH1 complex that is regulated through interactions with the RC subunits inside

First Data Release of the Hyper Suprime-Cam Subaru Strategic Program

The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layered imaging survey aimed at addressing some of the most outstanding questions in astronomy today, including the nature of dark matter and dark energy. The survey has been awarded 300 nights of observing time at the Subaru Telescope and it started in March 2014. This paper presents the first public data release of HSC-SSP. This release includes data taken in the first 1.7 years of observations (61.5 nights) and each of the Wide, Deep, and UltraDeep layers covers about 108, 26, and 4 square degrees down to depths of i~26.4, ~26.5, and ~27.0 mag, respectively (5sigma for point sources). All the layers are observed in five broad bands (grizy), and the Deep and UltraDeep layers are observed in narrow bands as well. We achieve an impressive image quality of 0.6 arcsec in the i-band in the Wide layer. We show that we achieve 1-2 per cent PSF photometry (rms) both internally and externally (against Pan-STARRS1), and ~10 mas and 40 mas internal and external astrometric accuracy, respectively. Both the calibrated images and catalogs are made available to the community through dedicated user interfaces and database servers. In addition to the pipeline products, we also provide value-added products such as photometric redshifts and a collection of public spectroscopic redshifts. Detailed descriptions of all the data can be found online. The data release website is https://hsc-release.mtk.nao.ac.jp/.Comment: 34 pages, 20 figures, 7 tables, moderate revision, accepted for publication in PAS

進路選択自己効力とキャリア教育およびキャリア支援プログラムの有用性との関連

本研究は,大学3回生対象のキャリア教育プログラム(career education program:以下,CEP3)や,大学の就職部・キャリアセンターが行ってきたキャリア支援プログラム(careersupport program:以下,CSP)に対して受講生が役に立ったかどうかという捉え方の程度(役立ち度)が進路選択自己効力と関連するのかを明らかにすることを目的とした。計21項目のCEP やCSP に対する役立ち度得点について因子分析を行ったところ,「就職情報調査獲得因子」「就職活動表出因子」「自己分析因子」の3因子が抽出された。各因子の役立ち度得点,および「相談相手の経路数」「アルバイト総継続期間」の5つを説明変数とし,進路選択自己効力尺度得点を目的変数とする重回帰分析を行った結果,「自己分析因子」に関連するプログラムに対して役に立つかどうかという捉え方と進路選択自己効力に関連があることが明らかとなった。これらの結果は,自己分析に関連したプログラムが進路選択自己効力の向上に効果的である可能性を示唆する。さらに,CEP が行われた授業への出席率と進路選択自己効力との違いを検討した結果,CEP を受講することが進路選択自己効力の低下防止に繋がる可能性が示唆された

Genome analysis of myelodysplastic syndromes among atomic bomb survivors in Nagasaki

Ionizing radiation is a risk factor for myeloid neoplasms including myelodysplastic syndromes (MDS), and atomic bomb survivors have been shown to have a significantly higher risk of MDS. Our previous analyses demonstrated that MDS among these survivors had a significantly higher frequency of complex karyotypes and structural alterations of chromosomes 3, 8, and 11. However, there was no difference in the median survival time between MDS among survivors compared with those of de novo origin. This suggested that a different pathophysiology may underlie the causative genetic aberrations for those among survivors. In this study, we performed genome analyses of MDS among survivors and found that proximally exposed patients had significantly fewer mutations in genes such as TET2 along the DNA methylation pathways, and they had a significantly higher rate of 11q deletions. Among the genes located in the deleted portion of chromosome 11, alterations of ATM were significantly more frequent in proximally exposed group with mutations identified on the remaining allele in 2 out of 5 cases. TP53, which is frequently mutated in therapy-related myeloid neoplasms, was equally affected between proximally and distally exposed patients. These results suggested that the genetic aberration profiles in MDS among atomic bomb survivors differed from those in therapy-related and de novo origin. Considering the role of ATM in DNA damage response after radiation exposure, further studies are warranted to elucidate how 11q deletion and aberrations of ATM contribute to the pathogenesis of MDS after radiation exposure