Study on the Kondo effect in the tunneling phenomena through a quantum dot

We review our recent studies on the Kondo effect in the tunneling phenomena through quantum dot systems. Numerical methods to calculate reliable tunneling conductance are developed. In the first place, a case in which electrons of odd number occupy the dot is studied, and experimental results are analyzed based on the calculated result. Tunneling anomaly in the even-number-electron occupation case, which is recently observed in experiment and is ascribed to the Kondo effect in the spin singlet-triplet cross over transition region, is also examined theoretically.Comment: 9 pages, 5 figures, Proceedings of the 2nd Hiroshima Workshop--Transport and Thermal Properties of Advanced Materials--, Hiroshima, Japan, August 16-19, 200

Issues in Student Surveys of a Permanent Experimental Stand in a Research Forest

学生実習による固定試験地調査を通じて，授業でのフィールド調査の割り当て方法について検討した。信州大学農学部手良沢山演習林のイチイ植林地において，参加学生20名を4班に分け，先回り探索（他の班との位置関係と未調査木の位置をもとに次の調査木を選ばせる方式）で，立木のサイズと位置の計測を実施した。全体では94本（班ごとに17～28本）の立木が調査され，胸高直径（DBH）は正規分布し，班ごとに見ても平均DBHに有意差はなく概ね正規分布していた。立木の位置情報をもとに調査中の各班の移動の軌跡を描いたところ，調査終了まで開始時点の各班の位置関係がほぼ保たれ，軌跡が互いに交錯することはなかった。また，班ごとで調査終了までの時間差はほとんど生じなかった。次の調査木への距離（平均の水平距離3.0～3.5m，垂直距離1.0～1.8m）に班ごとに有意差はなく，調査条件に班ごとの著しい違いはなかった。また，最も調査本数の多かった班で，標識番号の誤記入が1件見られ，それによって欠測と重複カウントをそれぞれ1本ずつ生じたのと等しい状況になった。各班の意思に任せる先回り方式での調査割り当てでは，班ごとの能率に合わせて調査地が分担されることが確かめられたが，問題点として調査ミスを検出しにくいことが挙げられた。Article環境科学年報 40:57-63(2018)research repor

Indigo plant improves serum lipid profiles

We investigated the effects of Polygonum tinctorium Lour (PTL), a plant commonly known as indigo, on biological parameters in an animal model of high-fat diet-induced obesity. Wistar rats fed a high-fat diet and treated with PTL showed lower serum levels of triglycerides and total cholesterol levels and a higher serum levels of HDL cholesterol than those in Wistar rats fed a high-fat diet without PTL treatment. The weight of mesenteric fat in PTL-treated rats was decreased compared to that in control rats not treated with PTL. In addition, energy metabolic rate in the dark period, but not in the light period, in PTL-treated rats was higher than that in control rats. Although a significant difference was not observed, body weight in PTL-treated rats tended to be decreased compared to that in control rats. The results show that PTL improves serum lipid profiles in Wistar rats with high-fat diet-induced obesity

Secondary BRCA1 Mutations in BRCA1-Mutated Ovarian carcinomas with platinum resistance.

Although ovarian carcinomas with mutated BRCA1 or BRCA2 are sensitive to platinum compounds, such carcinomas eventually develop platinum resistance. Previously, we showed that acquired resistance to cisplatin in BRCA2-mutated tumors can be mediated by secondary intragenic mutations in BRCA2 that restore the wild-type BRCA2 reading frame. Here, we show that secondary mutations of BRCA1 also occur in BRCA1-mutated ovarian cancer with platinum resistance. We evaluated nine recurrent BRCA1-mutated ovarian cancers previously treated with platinum compounds, including five with acquired platinum resistance, one with primary platinum resistance, and three with platinum sensitivity. Four of the six recurrent platinum-resistant tumors had developed secondary genetic changes in BRCA1 that restored the reading frame of the BRCA1 protein, whereas none of the three platinum-sensitive recurrent tumors developed BRCA1 sequence alterations. We immunohistochemically confirmed restored expression of BRCA1 protein in two cases with secondary mutations. Intriguingly, the case with primary platinum resistance showed back mutation of BRCA1 in the primary tumor and showed another secondary mutation in the recurrent tumor. Our results suggest that secondary mutations in BRCA1 can mediate resistance to platinum in BRCA1-mutated ovarian tumors

Prognostic Impact of Cardio-renal-anemia Syndrome in Patients at Risk for Heart Failure from the IMPACT-ABI study

Article信州医学雑誌 68(3): 139-147(2020)journal articl

Winter longitudinal variation in the body size of larval fishes in the Seto Inland Sea, Japan

This study revealed the spatial variation in abun-dance and body size of larval fishes in the Seto Inland Sea, Japan, in January 2014 and 2015. Fish larvae were col-lected by a 1.3-m-diameter ring net towed at the surface and at 10-m depth at 21 stations. The most dominant spe-cies was the sandlance Ammodytes japonicus, constituting 82% of total larval fish caught. The body size of A. japoni-cus was greater [ca. 9 mm total length (TL) in 2014] in eastern areas than in western areas (ca. 5 mm TL in 2014). This trend was also observed in rockfishes (Sebastiscus marmoratus and Sebastes inermis species complex), sug-gesting a common phenomenon in this region. Because the water temperature was lower in eastern areas, it is likely that the longitudinal differences in larval body size are attributable to earlier spawning in eastern areas caused by different temperature conditions.This work was partly supported by the Environment Research and Technology Development Fund (S-13) granted by the Ministry of the Environment, Japan.Electronic supplementary material: The online version of this article (doi:10.1007/s12562-017-1076-2) contains supplementary material, which is available to authorized users.アクセプト後にアブストラクト・キーワードの変更あり

Fibroblasts Show More Potential as Target Cells than Keratinocytes in COL7A1 Gene Therapy of Dystrophic Epidermolysis Bullosa

Dystrophic epidermolysis bullosa (DEB) is an inherited blistering skin disorder caused by mutations in the type VII collagen gene (COL7A1). Therapeutic introduction of COL7A1 into skin cells holds significant promise for the treatment of DEB. The purpose of this study was to establish an efficient retroviral transfer method for COL7A1 into DEB epidermal keratinocytes and dermal fibroblasts, and to determine which gene-transferred cells can most efficiently express collagen VII in the skin. We demonstrated that gene transfer using a combination of G protein of vesicular stomatitis virus-pseudotyped retroviral vector and retronectin introduced COL7A1 into keratinocytes and fibroblasts from a DEB patient with the lack of COL7A1 expression. Real-time polymerase chain reaction analysis of the normal human skin demonstrated that the quantity of COL7A1 expression in the epidermis was significantly higher than that in the dermis. Subsequently, we have produced skin grafts with the gene-transferred or untreated DEB keratinocytes and fibroblasts, and have transplanted them into nude rats. Interestingly, the series of skin graft experiments showed that the gene-transferred fibroblasts supplied higher amount of collagen VII to the new dermal–epidermal junction than the gene-transferred keratinocytes. An ultrastructural study revealed that collagen VII from gene-transferred cells formed proper anchoring fibrils. These results suggest that fibroblasts may be a better gene therapy target of DEB treatment than keratinocytes

The Epistatic Relationship between BRCA2 and the Other RAD51 Mediators in Homologous Recombination

RAD51 recombinase polymerizes at the site of double-strand breaks (DSBs) where it performs DSB repair. The loss of RAD51 causes extensive chromosomal breaks, leading to apoptosis. The polymerization of RAD51 is regulated by a number of RAD51 mediators, such as BRCA1, BRCA2, RAD52, SFR1, SWS1, and the five RAD51 paralogs, including XRCC3. We here show that brca2-null mutant cells were able to proliferate, indicating that RAD51 can perform DSB repair in the absence of BRCA2. We disrupted the BRCA1, RAD52, SFR1, SWS1, and XRCC3 genes in the brca2-null cells. All the resulting double-mutant cells displayed a phenotype that was very similar to that of the brca2-null cells. We suggest that BRCA2 might thus serve as a platform to recruit various RAD51 mediators at the appropriate position at the DNA–damage site.</p