45 research outputs found
Independent Effects of Temperature, Salinity, Ammonium Concentration and pH on Nitrification Rate of the Ariake Seawater Above Mud Sediment
The Ariake Sea located in the west parts of Kyushu Island is a semi-closed and macro-tidal shallow sea, and has the largest tidal flat in Japan. A large mud tidal flat with a productive ecosystem found along the western shoreline of the sea makes this area ideal as a major production site of nori (Porphyra yezoensis) in Japan. We determined the independent effect of temperature, salinity, ammonium concentration and pH on nitrification rates (NR) in the Ariake seawater above the mud sediment. The NR was determined by measuring accumulation of NO2-N production after adding sodium chlorate, an inhibitor of NO2-N to NO3-N oxidation. NRs were relatively high at 20-35 oC (optimum at 29.5 oC), but the rates were very low at 5, 10, and 40 oC. NRs increased sharply when increasing the salinity from 13 to 20 ppt, but it decreased drastically at salinity levels more than 35 ppt (optimum at 19 ppt). The relationship between ammonium concentration and NR showed a typical kinetic curve of enzymatic reaction with the maximum NR (Vmax) of 0.029 mM N.h-1 at 200 mM NH4-N (the half saturation constant (Ks) = 35 mM NH4-N). High NRs were determined at pH 7.5-8.0 (optimum pH 7.8). This is the first report on the independent effects of temperature, pH, salinity and NH4-N concentration on the NR of seawater, specifically the Ariake seawater
The ABC130 barrel module prototyping programme for the ATLAS strip tracker
For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector,
consisting of silicon pixel, silicon strip and transition radiation
sub-detectors, will be replaced with an all new 100 % silicon tracker, composed
of a pixel tracker at inner radii and a strip tracker at outer radii. The
future ATLAS strip tracker will include 11,000 silicon sensor modules in the
central region (barrel) and 7,000 modules in the forward region (end-caps),
which are foreseen to be constructed over a period of 3.5 years. The
construction of each module consists of a series of assembly and quality
control steps, which were engineered to be identical for all production sites.
In order to develop the tooling and procedures for assembly and testing of
these modules, two series of major prototyping programs were conducted: an
early program using readout chips designed using a 250 nm fabrication process
(ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm
processing (ABC130 and HCC130 chips). This second generation of readout chips
was used for an extensive prototyping program that produced around 100
barrel-type modules and contributed significantly to the development of the
final module layout. This paper gives an overview of the components used in
ABC130 barrel modules, their assembly procedure and findings resulting from
their tests.Comment: 82 pages, 66 figure
Analytical formalism for determining quantum-wire and quantum-dot band structure in the multiband envelope-function approximation
金属触媒を用いるアリル、アレニル、プロパルギル基移動反応および機能性材料への利用
京都大学0048新制・課程博士博士(工学)甲第16868号工博第3589号新制||工||1542(附属図書館)29543京都大学大学院工学研究科材料化学専攻(主査)教授 松原 誠二郎, 教授 辻 康之, 教授 杉野目 道紀学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA
One-Pot Synthesis of 3-Functionalized (Z)-Silyl Enol Ethers from 1-Arylallylic Alcohols by C,O-Difunctionalization of Dipotassio α,β-Dianion Intermediates
Previously reported syntheses of 3-functionalized silyl enol ethers using allyloxysilanes are hindered by undesirable reactions owing to retro Brook rearrangements. In this study, various 3-functionalized (Z)-silyl enol ethers were synthesized from readily available 1-arylallylic alcohols using (trimethylsilyl)methylpotassium as a base. C,O-Difunctionalization of the in-situ-generated dipotassio α,β-dianion with electrophiles and silyl chlorides is the key to the success of this transformation. Control experiments confirmed that the dianion has higher nucleophilicity and thermal stability than related siloxyallylpotassiums
Silver-Catalyzed Tandem Cyclization for Syntheses of Azaoxa- and Diazaspirocycles
1-Azaspirocycles are important structures present in many drugs and natural products. This paper describes the silver-catalyzed tandem cyclization strategy, which provides atom-economical access to various azaoxa- and diazaspirocycles from alkynes containing two appended oxygen- and nitrogen-based nucleophiles. Intramolecular attack of the pendant nucleophile on the in situ-generated iminium intermediate is the key to the success of this transformation
Myogenic Differentiation and Immunomodulatory Properties of Rat Adipose-Derived Mesenchymal Stem/Stromal Cells
The myogenic differentiation potential of MSCs is a key factor in their potential use as a cell source for muscle tissue repair and regeneration. Additionally, evaluating the immunomodulatory properties of MSCs is important to highlight their potential for regulating inflammation and supporting tissue regeneration. Given the limited literature on muscle differentiation potential and immunomodulatory properties, this study aims to characterize rat ADP MSCs for treating muscle disease. We isolated MSCs from adipose tissues around the periscapular region of the rats. We used a monoculture method for the myogenic differentiation and modified the myogenic induction medium by supplementing it with the growth factors FGF, HGF, and IGF. In rat ADP MSCs, expression of the MSC-specific marker, CD90, was 87.7%, while CD44 was 42.8%. For genes involved in immunomodulation, IGF1 and TGFB1 were highly expressed, while IL6 was poorly expressed. In addition to their trilineage differentiation potential, ADP MSCs exhibited the capacity to differentiate into myogenic cell lines, as evidenced by changes in cell morphology, leading to elongated and aligned structures and the expression of the MyoD and MYOG antibodies. The study found that ADP MSCs show great clinical promise for muscle regeneration
Chiral Brønsted Acid as a True Catalyst: Asymmetric Mukaiyama Aldol and Hosomi–Sakurai Allylation Reactions
Highly diastereo- and enantioselective
Mukaiyama aldol reaction
catalyzed by a new chiral Brønsted acid, <i>N</i>-(perfluorooctanesulfonyl)thiophosphoramide,
is described. The perfluorooctyl substituent on the sulfonyl group
of the catalyst plays an essential role in the stereoselection. The
catalyst also allows the asymmetric Hosomi–Sakurai allylation,
which has been considerably challenging due to the low reactivity
of allylsilanes. <sup>29</sup>Si and <sup>31</sup>P NMR monitoring
reveals the characteristic feature of the thiophosphoramide catalyst,
acting as a strong Brønsted acid even in the presence of excess
silyl nucleophiles, which cannot be found in other related phosphoric
acid analogues