Family Gauge Boson Production at the LHC

Family gauge boson production at the LHC is investigated according to a $U(3)$ family gauge model with twisted family number assignment. In the model we study, a family gauge boson with the lowest mass, $A_1^{\ 1}$, interacts only with the first generation leptons and the third generation quarks. (The family numbers are assigned, for example, as $(e_1, e_2, e_3)= (e^-, \mu^-, \tau^-)$ and $(d_1, d_2, d_3)=(b, d, s)$[or $(d_1, d_2, d_3)=(b, s, d)$]). In the model, the family gauge coupling constant is fixed by relating to the electroweak gauge coupling constant. Thus measurements of production cross sections and branching ratios of $A_1^{\ 1}$ clearly confirm or rule out the model. We calculate the cross sections of inclusive $A_1^{\ 1}$ production and $b \bar{b} \, (t \bar{t})$ associated $A_1^{\ 1}$ production at $\sqrt{s} = 14~\text{TeV}$ and $100~\text{TeV}$. With the dielectron production cross section, we discuss the determination of diagonalizing matrix of quark mass matrix, $U_{u}$ and $U_{d}$, respectively.Comment: 14 pages, 6 figure

The protein kinase C family for the regulation of cellular functions

The physiological importance of protein kinase C (PKC) activation is widely appreciated and well documented. It is now clear that there is more than one species of PKC molecule, and several discrete subspecies have been defined. These proteins are derived from both multiple genes and from alternative splicing of a single mRNA transcript, yet possess a primary structure containing conserved structural motifs with a high degree of sequence homology. In mammalian tissues at least seven subspecies can be distinguished, one of which is expressed only in the central nervous tissues. Biochemical and immunocytochemical studies have revealed that these PKC subspecies are differently located in particular cell types, and at limited intracellular locations. The enzyme subspecies purified from tissue show subtle differences in their mode of activation, sensitivity to Ca2+ and catalytic activity. It is worth noting that unsaturated free fatty acids including arachidonic, oleic, and linoleic acids dramatically activate several members of the PKC family in the presence of diacylglycerol at the basal level of Ca2+. It is possible that activation of the enzyme is an integral part of the signal-induced degradation cascade of various membrane phospholipids catalyzed by phospholipases C, A2 and perhaps D as well. Evidence now accumulates that PKC plays pivotal roles in control of a number of membrane functions, such as exocytosis, release reactions, and ion channel conductivity, as well as in cross-talks of various cell-signaling systems. It is also clear that PKC plays roles of crucial importance for regulation of gene expression and cell growth.Biomedical Reviews 1992; 1: 1-6

Adsorption of rare earth ions onto the cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis

The aim of this study is to investigate the potential of cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis 168 to adsorb rare earth ions. Freeze-dried cell powders prepared from both strains were used for the evaluation of adsorption ability for the rare earth ions, namely, La(III), Eu(III), and Tm(III). The rare earth ions were efficiently adsorbed onto powders of both wild-type strain (WT powder) and lipoteichoic acid-defective strain (a dagger LTA powder) at pH 3. The maximum adsorption capacities for Tm(III) by WT and a dagger LTA powders were 43 and 37 mg g(-1), respectively. Removal (in percent) of Tm(III), La(III), and Eu(III) from aqueous solution by WT powder was greater than by a dagger LTA powder. These results indicate that rare earth ions are adsorbed to functional groups, such as phosphate and carboxyl groups, of lipoteichoic acid. We observed coagulated a dagger LTA powder in the removal of rare earth ions (1-20 mg L-1) from aqueous solution. In contrast, sedimentation of WT powder did not occur under the same conditions. This unique feature of a dagger LTA powder may be caused by the difference of the distribution between lipoteichoic acid and wall teichoic acid. It appears that a dagger LTA powder is useful for removal of rare earth ions by adsorption, because aggregation allows for rapid separation of the adsorbent by filtration.ArticleAPPLIED MICROBIOLOGY AND BIOTECHNOLOGY. 97(8):3721-3728 (2013)journal articl

ES細胞におけるテロメラーゼ活性の制御機構の解析

金沢大学医薬保健研究域医学系本研究では細胞内におけるテロメラーゼ活性の制御機構を解析するために、ES細胞に存在するテロメラーゼ活性制御分子を同定することを目的として実験を進めた。マウスES細胞は、白血病阻害因子(LIF)を培地に添加することによって、その未分化状態を維持することができる。またES細胞は分化するとそのテロメラーゼ活性を失うことがすでに知られていた。そこで本研究ではES細胞の未分化状態を維持しているLIFの下流でテロメラーゼの活性が調節されていると考え、その可能性を検討した。まずLIF存在下で培養したES細胞、およびLIF除去後6日間培養して分化させたES細胞より粗抽出液を調製し、テロメラーゼの活性をTRAP法を用いて比較したが、両者の間で活性の差は見られなかった。次に同様な実験を、胚様体と呼ばれる構造体を形成させることによって分化させたES細胞で行ったところ、分化がかなり進んだ時点でようやくテロメラーゼ活性の低下が見られた。これらのことからテロメラーゼの活性はLIFの直下で制御されているというよりも、ヒストンのアセチル化、DNAのメチル化といったクロマチンの修飾が関与している可能性が示唆された。この実験と平行してLIFの下流分子であるRasが多くの癌細胞で活性化されていることからRasがテロメラーゼの活性制御に関与している可能性を検討した。ES細胞に活性型Rasを薬剤耐性遺伝子とともに導入し、7日間薬剤による選択を行った。回収した細胞よりRNAを調製してTenの発現量を調べたところ、コントロールに比べて活性型Rasを発現させた細胞ではTen量が増加せず、逆に減少していた。このことから、Rasは未分化ES細胞におけるテロメラーゼ活性の維持には関与していないと思われた。研究課題/領域番号:14028024, 研究期間(年度):2002出典：「ES細胞におけるテロメラーゼ活性の制御機構の解析」研究成果報告書　課題番号14028024（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-14028024/)を加工して作

オーファン核内受容体LRH-1によるES細胞の増殖制御機構

金沢大学医薬保健研究域医学系本年度は、LRH1による下流分子の発現制御機構に関する解析を進めるとともに、LRH1が他の転写因子とネットワークを形成している可能性を見い出した。LRH1による細胞周期関連分子Cdk2およびサイクリンEの発現制御機構に関しては、Cdk2およびサイクリンEの発現制御領域と思われる領域を単離し、Luciferaseをレポーター遺伝子として用いた実験を行った。その結果、発現制御領域にはLRH1の結合配列が見い出されず、これらの分子がLRH-1によって直接制御されているわけではないことが示唆された。これとは別に、LRH1が転写制御因子Dax1の発現を正に制御していることも見出した。興味深いことに、ある種の細胞においてはDax1はLRH1の負の制御因子として働くことが報告されている。これらのことから、ES細胞においてLRH1とDax1が互いに制御ループを形成している可能性が考えられた。さらにDax1が自己複製に必須な転写因子であるOct3/4に結合して、そのDNA結合能を阻害することを見い出した。一方で、Oct3/4はDax1の発現制御領域に直接結合し、その発現を正に制御していることも明らかにした。これらのことからES細胞においてDax1とOct3/4も互いに制御ループを形成していると思われる。以上の知見を総合すると、ES細胞において増殖を制御しているLRH1が、自己複製を制御しているOct3/4と、Dax1を介したクロストークを行っている可能性が考えられた。研究課題/領域番号:20058011, 研究期間(年度):2008 – 200

Numerical Simulations of Axisymmetric Flows in Astrophysics and their Visualization by a Video Movie

Numerical simulations of axisymmetric flow in four different astrophysical situations are performed, and their results are visualized by using a video movie. The situations considered are : 1) an accretion flow on to a gravitating compact object allowing maximum accrection ; 2) a jet formation in a flow past a gravitating rigid sphere ; 3) an interaction between a supersonic wind from a central object and a uniform supersonic incident flow ; 4) a wind bubble formed by spherical supersonic wind. The video tape of VHS/NTSC format is available from the author

Thoracic endovascular aneurysm repair in Japan: Experience with fenestrated stent grafts in the treatment of distal arch aneurysms

ObjectivesIn the West, stent grafts for endovascular repair of thoracic aortic aneurysms have been commercially available for several years, whereas in Japan, a manufactured stent graft was not approved for this application until March 2008. Nevertheless, endovascular thoracic intervention began to be performed in Japan in the early 1990s, with homemade devices used in most cases. Many researchers have continued to develop homemade devices. We have participated in joint design and assessment efforts with a stent graft manufacturer, focusing primarily on fenestrated stent grafts used in repairs at the distal arch, a site especially prone to aneurysm.MethodsFrom 1995 to February 2008, we performed about 1100 endovascular procedures to treat thoracic aortic aneurysms and 682 cases were performed at Tokyo Medical University. In 435 out of 682 the aneurysm was located in the area from the distal arch to the proximal descending aorta. Fenestrated stent grafts were inserted in 288 cases. Computed tomography scans were performed at 3, 6, and 12 months postoperatively and annually thereafter.ResultsThe initial success rate in the entire series was 95.2%. Complications included 26 cerebral infarctions (3.8%), six of which (0.9%) resulted in serious paralysis and changes in consciousness. Among patients who received fenestrated stent grafts, paraplegia occurred in 2.6%, aortic injury in 1.2%, and iliofemoral artery injury in 6.0%. No complications resulted from occlusion of aortic arch branches. At ≥2 years after intervention, aneurysm diameter was reduced in 62% of patients, 33% had no change, and 5% had a diameter enlargement. The stent graft complication rate during follow-up was 8.4%, the device fracture rate was 1.4%, and the device migration rate was 7%. The 5-year survival rate was 62.4%, with follow-up in 96.8% of the patients.ConclusionEndovascular repair has promising results in the descending thoracic aortic region, although some stent grafts and their delivery systems can still be improved. Additional commercial developments and available stent grafts designed for use in the distal arch are urgently needed

Effect of Helium Implantation on Tensile Properties of V-Ti-Cr-Si Type Alloy

Helium implantation of 50at.ppmHe by cyclotron accelerator was adopted to study helium effect on tensile properties of the V-5Ti-5Cr-1Si-Al-Y type alloy. Tensile tests were conducted at temperatures ranging from room temperature to 850℃ with strain rates from 6.7×10^ to 6.7×10^/s. Increase of yield stress was not appreciable in helium-implanted specimens except for 450℃. Intergranular fracture mode was observed specimens tested at temperatures above 450℃. Decrease of elongation was observed at all testing temperatures. Relationship between tensile strength and decrease of elongation was discussed