University of TsukubaIbaraki


University of TsukubaIbaraki

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Sivasankari J.,Anna University | Selvakumar Sellaiyan S.,University of TsukubaIbaraki | Sankar S.,Anna University | Devi L.V.,Anna University | Sivaji K.,University of Madras
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2017

Pure MgO, rare-earth (Er) doped MgO (MgO:Er), and alkali metal ions (Li, Na and K) co-doped MgO:Er [i.e. MgO: Er+X (X=Li, Na, and K)] nanopowders were synthesized by solution combustion method and characterized. The XRD analysis reveals the cubic structure and the substitution of dopants and co-dopants in MgO. Annealing at 800 °C, increases the sizes of nano-crystallites of all samples appreciably, indicating the grain growth and the improvement in crystallinity of all the samples. Increase in lattice parameter, d spacing and band gap were observed after annealing. Structural and morphological analysis using scanning electron microscope (SEM) and transmission electron microscope (TEM) studies has shown that the samples contain structures like agglomerated clusters. FT-IR spectra confirm the stretching mode of hydroxyl groups, carbonate and presence of MgO bonding. The characteristic wavelength ranging from 2600 cm−1 to 3000 cm−1 were assigned to transition of 4S3/2→4I13/2 and 4I11/2→4I15/2 of Er3+. © 2016 Elsevier B.V.

Tang L.,China University of Geosciences | Tang L.,University of TsukubaIbaraki | Santosh M.,China University of Geosciences | Santosh M.,University of Adelaide | And 3 more authors.
Precambrian Research | Year: 2016

The Trans-North China Orogen (TNCO) represents one of the major Paleoproterozoic collisional orogens across the central part of the North China Craton. Here we investigate the meta-carbonates (marbles and calc-silicate rocks) from the Fuping and Zanhuang Complexes in the TNCO through a combination of detrital zircon U–Pb geochronology, geochemistry and stable isotopes (carbon and oxygen). The U–Pb ages obtained from detrital zircons in both sequences show age populations of 2.50–2.57 Ga, 2.2–2.4 Ga, 2.0–2.1 Ga and 1.85–1.90 Ga. The depositional age for the Wanzi Group in the Fuping Complex is further constrained as 1.95–1.93 Ga and the Central Zanhuang Domain (Zanhuang Complex) as 2.03–1.90 Ga. All samples show nearly flat REE patterns below the concentration level of 1 in the shale-normalized REE distribution diagram. The dolomite–calcite marbles from the Fuping Complex have δ13C values ranging from −0.31‰ to 3.65‰ and δ18O values vary from −9.12‰ to −2.96‰. The calc-silicate rocks from the Fuping Complex show wide variation of δ13C (−1.56‰ to 3.30‰) and δ18O (−12.89‰ to −5.84‰). Dolomite marbles from the Zanhuang Complex show low δ13C and δ18O values ranging from −3.31‰ to −3.69‰ and −12.98‰ to −13.59‰. The dolomite–calcite marbles from the Zanhuang Complex display δ13C and δ18O compositions of −2.68‰ to 1.44‰ and −11.77‰ to −7.76‰, respectively. The correlations between the isotopic results (δ13C and δ18O) and geochemical compositions (Mn, Sr, Mn/Sr, Mg/Ca, Ca/Sr and Fe/Sr) suggest that the dolomite marbles from the Zanhuang Complex are strongly disturbed and the calc-silicate rocks are moderately affected by the post-depositional processes. The salient lithological, geochemical and isotopic features imply that the protoliths of the meta-carbonates were formed in a proximal and shallow marine environment. The Wanzi Group was deposited in a forearc basin and the Central Zanhuang Domain was formed in a back-arc basin. The geochemical imprints and biospheres of the oceanic basin in the Fuping area were possibly affected by the Lomagundi or Jatulian Event, resulting in the positive excursion of δ13C values in the dolomite–calcite marbles. However, the back-arc basin in the Zanhuang area was formed after the 2.1–2.0 Ga rifting event, thus it was generated after the Jatulian Event, thus preserving normal δ13C values of marine carbonates. © 2016 Elsevier B.V.

Satoh Y.,University of TsukubaIbaraki | Sugawara Y.,Ritsumeikan UniversityShiga | Wada T.,Ritsumeikan UniversityShiga
Journal of High Energy Physics | Year: 2016

We study type II string vacua defined by torus compactifications accompanied by T-duality twists. We realize the string vacua, specifically, by means of the asymmetric orbifolding associated to the chiral reflections combined with a shift, which are interpreted asdescribing the compactification on ‘T-folds’. We discuss possible consistent actions of the chiral reflection on the Ramond-sector of the world-sheet fermions, and explicitly construct non-supersymmetric as well as supersymmetric vacua. Above all, we demonstrate a simple realization of non-supersymmetric vacua with vanishing cosmological constant at one loop. Our orbifold group is generated only by a single element, which results in simpler models than those with such property known previously. © The Authors.

Ogura A.,RIKEN | Ogura A.,University of TsukubaIbaraki | Ogura A.,University of Tokyo
Experimental Animals | Year: 2017

Reproductive engineering techniques are essential for assisted reproduction of animals and generation of genetically modified animals. They may also provide invaluable research models for understanding the mechanisms involved in the developmental and reproductive processes. At the RIKEN BioResource Center (BRC), I have sought to develop new reproductive engineering techniques, especially those related to cryopreservation, microinsemination (sperm injection), nuclear transfer, and generation of new stem cell lines and animals, hoping that they will support the present and future projects at BRC. I also want to combine our techniques with genetic and biochemical analyses to solve important biological questions. We expect that this strategy makes our research more unique and refined by providing deeper insights into the mechanisms that govern the reproductive and developmental systems in mammals. To make this strategy more effective, it is critical to work with experts in different scientific fields. I have enjoyed collaborations with about 100 world-recognized laboratories, and all our collaborations have been successful and fruitful. This review summarizes development of reproductive engineering techniques at BRC during these 15 years. © 2017 Japanese Association for Laboratory Animal Science.

Dong Y.,University of TsukubaIbaraki | Chen H.,University of TsukubaIbaraki | Furuse K.,University of TsukubaIbaraki | Kitagawa H.,University of TsukubaIbaraki
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017

Given two data sets of user preferences and product attributes in addition to a set of query products, the aggregate reverse rank (ARR) query returns top-k users who regard the given query products as the highest aggregate rank than other users. In this paper, we reveal two limitations of the state-of-the-art solution to ARR query; that is, (a) It has poor efficiency when the distribution of the query set is dispersive. (b) It processes a lot of user data. To address these limitations, we develop a cluster-and-process method and a sophisticated indexing strategy. From the theoretical analysis of the results and experimental comparisons, we conclude that our proposals have superior performance. © 2017, Springer International Publishing AG.

Baig D.N.,Forman Christian College | Yanagawa T.,University of TsukubaIbaraki | Tabuchi K.,Shinshu University
Brain Research Bulletin | Year: 2017

Synaptic cell adhesion molecules (SCAMs) are a functional category of cell adhesion molecules that connect pre- and postsynapses by the protein-protein interaction via their extracellular cell adhesion domains. Countless numbers of common genetic variants and rare mutations in SCAMs have been identified in the patients with autism spectrum disorders (ASDs). Among these, NRXN and NLGN family proteins cooperatively function at synaptic terminals both of which genes are strongly implicated as risk genes for ASDs. Knock-in mice carrying a single rare point mutation of NLGN3 (NLGN3 R451C) discovered in the patients with ASDs display a deficit in social interaction and an enhancement of spatial learning and memory ability reminiscent of the clinical phenotype of ASDs. NLGN4 knockout (KO) and NRXN2α KO mice also show a deficit in sociability as well as some specific neuropsychiatric behaviors. In this review, we selected NRXNs/NLGNs, CNTNAP2/CNTNAP4, CNTN4, ITGB3, and KIRREL3 as strong ASD risk genes based on SFARI score and summarize the protein structures, functions at synapses, representative discoveries in human genetic studies, and phenotypes of the mutant model mice in light of the pathophysiology of ASDs. © 2016 Elsevier Inc.

Kakutani Y.,University of TsukubaIbaraki | Kamiya S.,University of TsukubaIbaraki | Omi N.,University of TsukubaIbaraki
Journal of Nutritional Science and Vitaminology | Year: 2015

“Shushoku,” “Shusai,” and “Hukusai” are staple food, main dish, and side dish, respectively. The recommended meal in Japan is a combination of “Shushoku,” “Shusai,” and “Hukusai”; however, it remains unclear whether there is an association between the frequency of these meals and intake of nutrients and food groups. This cross-sectional study examined the association between the frequency of meals combining “Shushoku, Shusai, and Hukusai” and intake of nutrients and food groups among 664 Japanese young adults aged 18–24 y. The dietary habits of the subjects during the preceding month were assessed using a validated brief-type self-administered diet history questionnaire. The frequency of meals combining “Shushoku, Shusai, and Hukusai” was self-reported according to four categories: “less than 1 d or 1 d/wk,” “2 or 3 d/wk,” “4 or 5 d/wk,” and “every day.” In both women and men, there was an association between the higher frequency of these meals and higher intake of the following food groups: pulses, green and yellow vegetables, other vegetables, mushrooms, seaweeds, fish and shellfish, and eggs. Moreover, there was an association with higher intake of protein, polyunsaturated fat, n-6 and n-3 polyunsaturated fat, total dietary fiber, soluble and insoluble dietary fiber, β-carotene, a-tocopherol, vitamin K, thiamin, riboflavin, folate, pantothenic acid, vitamin C, potassium, calcium, magnesium, iron, and copper, and lower intake of carbohydrate in both women and men. Our findings support the hypothesis that the meals combining “Shushoku, Shusai, and Hukusai” may be associated with intake of many food groups and nutrients among Japanese young adults. © 2015, Center for Academic Publications Japan. All rights reserved.

Hizawa N.,University of TsukubaIbaraki
International Journal of COPD | Year: 2015

In the combined use of bronchodilators of different classes, ie, long-acting β2-agonists (LABAs) and long-acting muscarinic antagonists (LAMAs), bronchodilation is obtained both directly, through LABA-mediated stimulation of β2-adrenergic receptors, and indirectly, through LAMA-mediated inhibition of acetylcholine action at muscarinic receptors. The clinical trial data for LABAs/LAMAs in the treatment of chronic obstructive pulmonary disease (COPD) continue to be promising, and these combinations will provide the convenience of delivering the two major bronchodilator classes, recommended as first-line maintenance options in COPD treatment guidelines. COPD is a complex condition that has pulmonary and extrapulmonary manifestations. These clinical manifestations are highly variable, and several are associated with different responses to currently available therapies. The concept of a COPD phenotype is rapidly evolving from one focusing on the clinical characteristics to one linking the underlying biology to the phenotype of the disease. Identification of the peculiarities of the different COPD phenotypes will permit us to implement a more personalized treatment in which the patient’s characteristics, together with his or her genotype, will be key to choosing the best treatment option. At present in Japan, fixed combinations of inhaled corticosteroids (ICSs) and LABAs are frequently prescribed in the earlier stages of COPD. However, ICSs increase the risk of pneumonia. Notably, 10%–30% of patients with COPD with or without a history of asthma have persistent circulating and airway eosinophilia associated with an increased risk of exacerbations and sensitivity to steroids. Thus, sputum or blood eosinophil counts might identify a subpopulation in which ICSs could have potentially deleterious effects as well as a subpopulation that benefits from ICSs. In this review, I propose one plausible approach to position ICSs and LABAs/LAMAs in clinical practice, based on both the extent of airflow obstruction and the presence of an asthma component or airway eosinophilic inflammation. This approach is a tentative move toward personalized treatment for COPD patients, and with progress in knowledge and developments in physiology, lung imaging, medical biology, and genetics, identification of COPD phenotypes that provide prognostic and therapeutic information that can affect clinically meaningful outcomes is an urgent medical need. © 2015 Hizawa.

Sugiura Y.,University of TsukubaIbaraki | Okamoto F.,University of TsukubaIbaraki | Okamoto Y.,University of TsukubaIbaraki | Hiraoka T.,University of TsukubaIbaraki | Oshika T.,University of TsukubaIbaraki
Investigative Ophthalmology and Visual Science | Year: 2014

Purpose. To evaluate contrast sensitivity (CS) in patients with epiretinal membrane (ERM) following vitrectomy and to investigate the relationship between CS and foveal microstruc-tures with spectral-domain optical coherence tomography (SD-OCT).Methods. Thirty-one eyes of 31 patients with ERM were included. We examined CS with a CSV-1000E chart, a logMAR best-corrected visual acuity (BCVA), and foveal microstructure by using SD-OCT before and at 6 months after surgery. From the CS data, the area under the log contrast sensitivity function (AULCSF) was calculated. Based on the OCT images, we quantified the mean thickness of the ganglion cell layer (GCL), the inner nuclear layer (INL), and the outer retinal layer (outer nuclear layer and outer plexiform layer [ONL+OPL]). The status of the photoreceptor inner and outer segment junction (IS/OS) and external limiting membrane (ELM) was also evaluated.Results. Vitrectomy significantly improved logMAR BCVA and AULCSF. Even in patients with poor improvement of visual acuity (changes in logMAR BCVA by surgery was ≤0.2), postoperative AULCSF significantly increased by treatment (P < 0.05). Postoperative AULCSF showed a significant correlation with preoperative (P < 0.05) and postoperative (P < 0.05) ONL+OPL thickness, whereas other parameters were not relevant. Postoperative logMAR BCVA significantly correlated with postoperative status of IS/OS (P < 0.05) and preoperative ONL+OPL thickness (P < 0.05).Conclusions. In patients with ERM, CS improved even though their visual acuity did not recover significantly by vitrectomy. CS was associated with the thickness of outer retinal layer. © 2014 The Association for Research in Vision and Ophthalmology, Inc.

Matsuda M.,University of TsukubaIbaraki | Kurosaki K.,University of TsukubaIbaraki | Okamura N.,University of TsukubaIbaraki
Journal of Reproduction and Development | Year: 2014

Exposure of mice to a high dose of estrogens including diethylstilbestrol (DES) during the neonatal period modifies the developmental plan of the genital tract, which leads to various permanent changes in physiology, morphology and gene expression. These changes include development of an abnormal vaginal epithelium lined with hyperplastic mucinous cells accompanied by Tff1 gene expression in mice. Here, the influence of vitamin D on the direct effect of estrogen on the developing mouse vagina was examined. The mid-vagina of neonatal mice was cultured in a serum-free medium containing estradiol-17β (E2) and various concentrations of 1,25-dihydroxyvitamin D3 (1,25(OH)2D) ex vivo and then was transplanted under the renal capsule of ovariectomized host mice for 35 days. Exposure to E2 alone caused the vaginal tissue to develop estrogenindependent epithelial hyperplasia and to express TFF1 mRNA, while addition of a low nanomolar amount of 1,25(OH)2D added at the same time as E2 to the culture medium attenuated the effects of estrogen. Expression of vitamin D receptor was also evident in the neonatal mouse vagina. Interestingly, addition of 25-hydroxyvitamin D3, a pro-activated form of vitamin D, at the micromolar level was found to be potent in disrupting the developmental effects of E2, while cholecalciferol was not at least at the dose examined. Correspondingly, expression of Cyp27B1, a kidney-specific 25-hydroxyvitamin D hydroxylase, was evident in the neonatal mouse vagina when examined by RT-PCR. In addition, simultaneous administration of 1,25(OH)2D successfully attenuated DES-induced ovary-independent hyperplasia in the vagina in neonatal mice in vivo. Thus, manipulation of vitamin D influenced the harmful effects of estrogens on mouse vaginal development. ©2014 by the Society for Reproduction and Development.

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