サンギョウ ハイキブツ オ モチイタ ケイサン カルシウム スイワブツ ノ ゴウセイ ト ソノ リヨウ ニ カンスル ケンキュウ

本論文は，リサイクルの対象として，ケイ石廃泥，石炭灰(フライアッシュ)を取り扱い，それ らがより有効に再利用されるための処理条件，また反応生成物の性質などについて述べている. ケイ石廃泥は，砕石を水洗して出荷される際に発生する汚濁水を凝集沈殿し，フィルタープレス で、脱水後，排出されているものである.化学組成はシリカ質に富み，粒径も産業廃棄物としては比 般的揃っている.また，砕石粉であることから，表面が活性であり，化学的反応性が期待される. これらの点を考慮し，消石灰と混合・水熱処理によりケイ酸カルシウム硬化体を作製し，軽量か つ構造材としての用途開発の可能性について検討した.その結果，消石灰とケイ石廃泥の配合比， CaO/SiO2=0.40 の試料が種々の水熱処理条件などによらず，他の配合比の試料より大きな曲げ強さ を示すことが分かった.この時，硬化体を構成する鉱物は，低結晶のトバモライト族であった. しかし，通常の水熱処理温度180℃で，最大曲げ強さ(約30MPa)を示すのに48時間以上要した. そのため，反応促進を目的として各種アルカリ添加の効果を検討したところ，少量の添加で反応時 間が短縮されると共に，曲げ強さも増加した.これは，アルカリの添加がシリカ質の溶出を促進し すみやかにケイ酸カルシウム水和物が生成されたためと考えられる. また，コロイダルシリカを添加した実験では，コロイダルシリカが消石灰と優先的に反応し，比 較的空隙の多い反応層を形成した.この組織では，石英の物質移動が容易に行われるため，ケイ石 廃泥の反応率も上昇した.硬化体の軽量化を考慮した配合の場合，かさ密度は1.17と，従来の試料 1.75の約2/3程度となったが，曲げ強さは13MPaと低下した. しかし，市販の発泡コンクリート と比較すると，曲げ強さは数十倍あり，断熱効果を有する構造材としての使用が考えられる. 一方，石炭灰(フライアッシュ)は，燃焼炉から発生する代表的な産業廃棄物であるが，石炭灰 のなかでシリカ成分比が高く強熱減量値の低いものは，とくにフライアッシュと称されている. 小型燃焼炉などから発生する，低品位石炭灰は未燃焼カーボンを含み，また，表面が硬石膏，炭 酸カルシウムなどに覆われているため，反応性が乏しい.そのため， リサイクルの対象とならず， 大半が海面埋立，陸上埋立されている. 本研究では， HC1溶液，NaOH溶液で、反応阻害層を取り除き，従来の水熱処理法によりケイ 酸カルシウム硬化体の作製を試みた.その結果，かさ密度1.32，曲げ強さ12.OMPaと実用強度を 有する硬化体が作製できることが分かった.さらに，この試料にケイ石廃泥をシリカ分の1/4程度 添加した場合では，曲げ強さが18～19M P aに改善された. フライアッシュは，発生量が厖大であることから.大規模使用を考慮し，排水溝などで利用可能 な水質浄化能力を有する構造材への開発を検討した.すなわち，ケイ酸カルシウム硬化体の多孔質 組織，組成が微生物保持担体として有効であることを期待したものである.この実験では，比表面 積が大きく，また曲げ強さも大きい試料を選定し，人工排水を用いて水質浄化試験を行った.微生 物保持担体としてのケイ酸カルシウム硬化体の性能は，活性炭と同程度であり，構造材かつ微生物 保持担体として利用可能な材料であることが明らかになった

Lambert-Eaton syndrome antibodies inhibit acetylcholine release and P/Q-type Ca2+ channels in electric ray nerve endings

The types of voltage-dependent calcium channels (VDCCs) present in the cholinergic terminals isolated from the electric organ of the ray, Narke japonica, were characterized on the basis of their pharmacological sensitivity to specific antagonists. Inhibition of these channel types by autoantibodies from patients with the Lambert-Eaton syndrome (LES) was then studied to determine the specificity of the pathogenic IgG. In normal untreated synaptosomal preparations, maximal doses of N- and P and/or Q-type Ca2+ channel antagonists, -conotoxin GVIA and -agatoxin IVA, inhibited depolarization-evoked ACh release by 47 % and 43 %, respectively. Calciseptine, an L-type VDCC antagonist, caused a 20 % reduction in the release. This indicates that the exocytotic release process is predominantly mediated by N- and P/Q-type VDCCs. LES IgG or sera caused an inhibition of ACh release by 39-45 % in comparison with the control antibody-treated preparations. The ionomycin-induced ACh release, however, was not altered by the antibodies. Additionally, the same LES antibodies inhibited whole-cell calcium currents (ICa) in bovine adrenal chromaffin cells. Thus, the pathogenic antibodies exert their action on VDCCs present in the synaptosomes. The efficacy of three Ca2+ channel antagonists in blocking ACh release was determined in preparations pretreated with LES IgG. -Agatoxin IVA produced only an additional 3-5 % reduction in release beyond that obtained with LES antibodies. Despite the pretreatment with LES IgG, -conotoxin GVIA and calciseptine inhibited the release to nearly their control levels. These results indicate that LES antibodies mainly downregulate P/Q-type Ca2+ channels which contribute to presynaptic transmitter release from the cholinergic nerve terminals of electric organ. The present findings are consistent with the hypothesis that P/Q-type VDCCs at the neuromuscular junction are the target of LES antibodies and that their inhibition by the antibodies produces the characteristic neuromuscular defect in this disease

Use of Recycled Steel Machining Chips and Aluminum Can Shreds for Synthesizing Iron Aluminide Intermetallic Alloys

Some iron aluminide intermetallic alloys based on Fe3Al or FeAl have been synthesized from recycled raw materials of steel machining chips and aluminum can shreds. The former was an industrial waste made at a bearing case maker, and it had a spiral shape and a length less than 1 mm and contained 0.87 wt% C, 0.21 wt% Si, 1.53 wt% Cr with some other minor elements. The latter, on the other hand, was made by shredding used aluminum cans, and it had a flaky shape and a edge length of 2 to 3 mm and contained 2.3 wt% Mg, 0.36 wt% Fe, 0.88 wt% Mn with some other minor elements. When compacts of the steel and aluminum mixture were heated in a crucible in an argon atmosphere, they exothermically reacted and produced iron aluminide intermetallic alloys. For comparison, similar alloys were produced from pure iron and aluminum by melting them in the same heating apparatus. The bending strength, fracture toughness, Vickers hardness and wear resistance of the alloys synthesized from the recycled raw materials were more excellent than or similar to those of the alloys produced from pure iron and aluminum

Reactive Casting of Ni-Al-Fe Ternary Intermetallic Alloys

NiAl-base intermetallic alloys containing iron up to 25 at% are produced by reactive casting, which involves an exothermic reaction between elemental liquids and enables one to cast high-melting-point intermetallic alloys without the need of external heating. In this study, aluminum liquid at 1023 K and a moltennickeliron alloy at 1773 K are mixed to produce a molten Ni–Al–Fe ternary intermetallic alloy with a temperature of over 2300 K, which is approximately 400 K higher than the melting point of the alloy produced. The concentrations of the constituent elements are approximately homogeneous in the ingot of 30 mm in diameter and 130 mm in height. The grain size of the ingot decreases, as the iron content increases. The increase in iron content improves the hardness, bending strength and wear resistance of the alloy. Young's modulus of the alloy decreases with the increase in temperature and iron content

Galectin-9 Is a High Affinity IgE-binding Lectin with Anti-allergic Effect by Blocking IgE-Antigen Complex Formation

Galectin (Gal)-9 was first described as an eosinophil chemoattractant. With the progress in research, Gal-9 has come to be known as a versatile immunomodulator that is involved in various aspects of immune regulations, and the entire picture of the function still remains elusive. To uncover as-yet unknown activity of Gal-9, we have been examining the effect of the protein in various disease animal models. Here we show that Gal-9 attenuated asthmatic reaction in guinea pigs and suppressed passive-cutaneous anaphylaxis in mice. These results indicate the mast cell stabilizing effect of Gal-9. In vitro studies of mast cell degranulation involving RBL-2H3 cells demonstrated that Gal-9 suppressed degranulation from the cells stimulated by IgE plus antigen and that the inhibitory effect was completely abrogated in the presence of lactose, indicating lectin activity of Gal-9 is critical. We found that Gal-9 strongly and specifically bound IgE, which is a heavily glycosylated immunoglobulin, and that the interaction prevented IgE-antigen complex formation, clarifying the mode of action of the anti-degranulation effect. Gal-9 is expressed by several mast cells including mouse mast cell line MC/9. The fact that immunological stimuli of MC/9 cells augmented Gal-9 secretion from the cells implies that Gal-9 is an autocrine regulator of mast cell function to suppress excessive degranulation. Collectively, these findings shed light on a novel function of Gal-9 in mast cells and suggest a beneficial utility of Gal-9 for the treatment of allergic disorders including asthma