Liquid-Liquid Direct Contact Heat Exchange Using a Perfluorocarbon Liquid for Waste Heat Recovery : Heat Transfer Characteristics obtained with Perfluorocarbon Droplets Descending in a Hot Water Medium

This paper deals with the heat transfer characteristics of a liquid-liquid direct contact operation in which a Perfluorocarbon (PFC) liquid is released in a hot water stream, a low-grade heat source such as urban sewage, for the purpose of heat recovery from it. The paper reports on a set of experiments in which a PFC liquid (1800 kg/m^3 at 20℃) was continuously injected from a single, downward-facing nozzle into a slow, upward flow of hot water to be disintegrated into droplets descending in, and thereby heated from the water flow. The results of the experiments show how the size distribution and the translational motions of the droplets affect the overall coefficient for the water-flow-to-droplets heat transfer and also the temperature effectiveness for the droplets.近年、未利用エネルギー活用の観点から、工場や家庭温排水などを熱源として利用する廃熱回収用熱交換器の開発が急務となっている。従来のシェルアンドチューブなどの隔壁型交換器では、伝熱面に排水中のごみやスケールが堆積し、その伝熱効率が著しく低下する等の問題点があった。この問題解決として、このような汚濁排水中に、非水溶性熱媒体を噴射・注入し、直接接触熱交換により、熱抽出が可能となる。このような直接接触熱交換法は、個体壁伝熱面の汚れによる伝熱効率低下の問題がなくなり、廃熱回収用熱交換方式として極めて有効である。さらに、この熱交換法は、個体壁を介さないために高い熱通過率が得られ、小温度差での熱交換に有効である。また、液－液の直接接触する界面が、そのまま伝熱面に相当するため、単位体積当たりの伝熱面積が増加する利点を有する。本研究は、下水等の汚れた熱水源より効率的な熱回収をする手段として液液直接熱交換法に注目したものであり、熱回収媒体としてフッ素系不活性液体を熱源水へ噴射し、形成したフッ素系不活性液滴群と熱源水の直接接触による、流動及び熱伝達特性を検討するものである。すなわち、円形単孔ノズルから高密度のフッ素系不活性液体を熱源である温水槽へ上部より噴射し、その液滴群形成過程の観察及び液滴群の流れの特性の解明を通じて、熱水源からの直接熱交換法による熱抽出に関する基礎特性を明らかにすることを目的とする。最終的に、この種の熱源水よりの熱回収媒体としてフッ素系不活性液体を用いた場合における実用に寄与する無次元熱伝達率等に関する実験整理式の検討をも行うものである

Rapid separation method for protactinium from uranium using manganese oxide filter cake

Adsorption and separation performance of protactinium (Pa) on a manganese oxide (MnO2)filter cake was studied by measurements of α-, β-, and γ-rays and the results compared with those ofsolid-phase extraction using MnO2 and TK400 resins. The MnO2 filter cake method demonstratedexcellent recovery. Radiochemical purity was comparable with that achieved by other newly developedmethods, with only small amounts of contamination by Bi, Ra, Ac, Th, and U. The method, originallydeveloped for recovering Pa from uranium solutions, has the merit of rapidity in chemical separation. Itmay be able to be applied to other purposes, such as investigation of the chemical properties of dubnium,a superheavy element

The Conserved Domain CR2 of Epstein–Barr Virus Nuclear Antigen Leader Protein Is Responsible Not Only for Nuclear Matrix Association but Also for Nuclear Localization

AbstractThere is a growing body of evidence for the importance of the nuclear matrix in various nuclear events including gene expression and DNA replication. Epstein–Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) is a nuclear matrix-associated protein that has been suggested to play an important role in EBV-induced transformation. To define the biological significance of the association of EBNA-LP with the nuclear matrix, we mapped the domain of EBNA-LP responsible for nuclear matrix association and investigated the functions of the EBNA-LP mutant mutagenized by substitution of alanines for the cluster of arginine residues in the mapped region. The results of the present study were as follows. (i) Transiently expressed EBNA-LP in COS-7 or BOSC23 cells was associated with the nuclear matrix, similarly to that in EBV-infected B cells. (ii) Mutational analysis of EBNA-LP revealed that a 10-amino acid segment of EBNA-LP is critical for nuclear matrix association of the protein. Interestingly, the identified region overlapped with the region CR2 of EBNA-LP conserved among a subset of primate gammaherpesviruses. The identified segment is referred to as EBNA-LP NMTS (nuclear matrix targeting signal). (iii) The EBNA-LP mutant with the arginine to alanine substitutions in NMTS was no longer localized not only to the nuclear matrix but also to the nucleus. (iv) The EBNA-LP mutant lacked its ability to coactivate EBNA-2-dependent transactivation. These results indicated that EBNA-LP needs to be localized in the nucleus and/or associated with the nuclear matrix through CR2 to elicit its function such as the coactivation of the EBNA-2-dependent transcriptional activation

Improvements on the method for determining of 210Pb and 210Po in lead

An improved method is proposed to determine the content of 210Pb in lead using 210Po measured by alpha-ray spectrometry. This improved method, which is based on radiochemical separation by DDTC-toluene extraction, employs EDTA and citrate as masking reagents for the lead ions. To selectively extract polonium from an alkaline solution, the pH dependency was examined using a liquid scintillation counting method. And pH 9 was chosen as an extraction condition. Then 210Po was electrodeposited on a stainless steel disk, and the chemical recovery was followed by 209Po tracer. The effectiveness of the new method was validated by the agreement with the analytical results from five samples as determined by gamma-ray spectrometry. © 2010 Akadémiai Kiadó, Budapest, Hungary

金属タンパク質中の活性位における超微細電場測定

ガンマ線摂動角相関(PAC)法は、物質中のプローブ核に加えられる外場の情報を得ることで,その核の属する原子付近の電子状態や物質の構造を探ることができる。この手法は適応される測定試料の状態に制限されることなく液体状態でも超微細場測定が可能である。この特長を生かして近年構造と機能が注目されているタンパク質への適用を考えた。本研究では,溶液中の状態についての情報を得るために生体分子の活性中心での超微細場測定をPAC法で試みた。マビシアニン野生型と変異型(Thrl5Ala-Mav)を測定試料に選び,このマビシアニン中の銅の位置にPACプローブ親核である^Cd(半減期2.5h)を入れ,水溶液中のpHに対するマビシアニンの銅活性部位における超微細場測定を行った。その結果pH6.0-8.0の範囲では、野生型マビシアニンについて活性部位の電場勾配V_は1.48〜2.08×10^V・m^であるのに対し、変異型では0.43〜1.49×10^V・m^という値になった。変異型の値はいずれも対応するpHの野生型に比較して低い値になった。また,pH6と7.5の間での電場勾配の急激な変化は同様に見られた。電場勾配の比較より,野生型と変異型の間で何らかの構造の変化があったと考えられる。変異型は野生型の15位トレオニンをアラニンに置換したもので酸化還元電位の変動が確認されている。さらに詳しくその変化について議論を進めるために,活性部位周りの元素と似ている様々な配位子から作ったオキシンなど5種類の錯体に関する電場勾配を求める同様の実験を行った。また,PACプローブ核の依存性をみるために^Cd以外にプローブ親核として^Cd,^Inの測定を行った。これらのデータから,同じ化合物でもプローブ核を変えた場合では電場勾配が違っていることがわかった。これはプローブ核の元素自体か壊変過程における後遺効果の違いであると考えられる。また,測定した錯体の電場勾配値はマビシアニンの電場勾配値に比べるとほとんどは低いものであったが、キノリン-8-カルボン酸錯体はマビシアニンに近い値を与えることがわかった。これらのデータはタンパク質中の金属に対する配位の特異性を示唆している一方で、キノリン-8-カルボン酸錯体の配位構造との類似が示唆される。タンパク質の配位構造を考えるためにもこれらの配位子についてさらに詳しい検討をする必要があると考えられる.The structure around the metal site of mavicyanin, a protein molecule with a copper site, was investigated by using time-differential perturbed angular correlation of γ-rays related to a metastable state of ^In. Its parent nuclei of ^Cd are subjected to β^- decay to populate the 749 keV excited state of ^In with a half-life t_=2.49 h, decaying to the 315 keV excited state through the 660 keV intermediate state having a spin I= 3/2, t_=53.6 ns, and an electric quadrupole moment Q=(-)0.59(1) b. The parent nuclei ^Cd were obtained by irradiating enriched ^CdO (96.53%) for about 30 min in thermal neutron flux of 1.93×10^ cm^s^ or 2.34×10^ cm^s^ at Kyoto University Research Reactor Institute. The Cd ions from solution of the irradiated sample were substituted in the metal sites of mavicyanin, from which Cu ions were extracted beforehand. The sample solution was subjected to PAC measurements.The field gradient values were determined from the PAC spectra of wild-type mavicyanin for pH=6.0, 7.5 and 8.0 to be 1.48×10^ to 2.08×10^ Vm^, while those of a mutant-type mavicyanin, Thr15Ala-Mav, were 0.43×10^ to 1.49×10^ Vm^. Compared with the value, 1.71×10^ Vm^ reported on stellacyanin, the results obtained in this work seem to be reasonable. It was also found that there is a steep change of the gradient between 6.0 and 7.5 in pH for both of the proteins. In order to clarify the relevant change of the proteins in structure, several metal chelates were subjected to the PAC measurement as described above for comparison. In addition to that, additional parent nuclides of Cd-111m and In-111 decaying to PAC probes were used for the experiment for comparison as well. The latter experiment demonstrated that there is clear difference between proteins and metal chelates in gradient fields probably due to coordination of relevant ligands and that there is dependence of the used probes in measurement of the gradients.研究課題/領域番号:16550052, 研究期間(年度):2004-2005出典：「金属タンパク質中の活性位における超微細電場測定」研究成果報告書　課題番号16550052 (KAKEN：科学研究費助成事業データベース（国立情報学研究所）)　　　本文データは著者版報告書より作

Onset heart rate of microvolt-level T-wave alternans provides clinical and prognostic value in nonischemic dilated cardiomyopathy

AbstractObjectivesThis study was designed to determine the prognostic value of onset heart rate (OHR) in T-wave alternans (TWA) in patients with nonischemic dilated cardiomyopathy (DCM).BackgroundOne of the current major issues in DCM is to prevent sudden cardiac death (SCD). However, the value of the OHR of TWA as a prognostic indicator in DCM remains to be elucidated.MethodsWe prospectively investigated 104 patients with DCM undergoing TWA testing. The end point of this study was defined as SCD, documented sustained ventricular tachycardia/ventricular fibrillation. Relations between clinical parameters and subsequent outcome were evaluated.ResultsForty-six patients presenting with TWA were assigned to one of the following two subgroups according to OHR for TWA of ≤100 beats/min: group A (n = 24) with OHR ≤100 beats/min and group B (n = 22) with 100 < OHR ≤ 110 beats/min. T-wave alternans was negative in 37 patients (group C) and indeterminate in 21 patients. The follow-up result comprised 83 patients with determined TWA. During a follow-up duration of 21 ± 14 months, there was a total of 12 arrhythmic events, nine of which included three SCDs in group A, two in group B and one in group C. The forward stepwise multivariate Cox hazard analysis revealed that TWA with an OHR ≤100 beats/min and left ventricular ejection fraction were independent predictors of these arrhythmic events (p = 0.0001 and p = 0.0152, respectively).ConclusionsThe OHR of TWA is of additional prognostic value in DCM

Improvements on the method for determining of 210Pb and 210Po in lead

金沢大学理工研究域An improved method is proposed to determine the content of 210Pb in lead using 210Po measured by alpha-ray spectrometry. This improved method, which is based on radiochemical separation by DDTC-toluene extraction, employs EDTA and citrate as masking reagents for the lead ions. To selectively extract polonium from an alkaline solution, the pH dependency was examined using a liquid scintillation counting method. And pH 9 was chosen as an extraction condition. Then 210Po was electrodeposited on a stainless steel disk, and the chemical recovery was followed by 209Po tracer. The effectiveness of the new method was validated by the agreement with the analytical results from five samples as determined by gamma-ray spectrometry. © 2010 Akadémiai Kiadó, Budapest, Hungary

The Menin Tumor Suppressor Protein Is an Essential Oncogenic Cofactor for MLL-Associated Leukemogenesis

SummaryThe Mixed-Lineage Leukemia (MLL) protein is a histone methyltransferase that is mutated in clinically and biologically distinctive subsets of acute leukemia. MLL normally associates with a cohort of highly conserved cofactors to form a macromolecular complex that includes menin, a product of the MEN1 tumor suppressor gene, which is mutated in heritable and sporadic endocrine tumors. We demonstrate here that oncogenic MLL fusion proteins retain an ability to stably associate with menin through a high-affinity, amino-terminal, conserved binding motif and that this interaction is required for the initiation of MLL-mediated leukemogenesis. Furthermore, menin is essential for maintenance of MLL-associated but not other oncogene induced myeloid transformation. Acute genetic ablation of menin reverses aberrant Hox gene expression mediated by MLL-menin promoter-associated complexes, and specifically abrogates the differentiation arrest and oncogenic properties of MLL-transformed leukemic blasts. These results demonstrate that a human oncoprotein is critically dependent on direct physical interaction with a tumor suppressor protein for its oncogenic activity, validate a potential target for molecular therapy, and suggest central roles for menin in altered epigenetic functions underlying the pathogenesis of hematopoietic cancers

MFG-E8 Regulates Angiogenesis in Cutaneous Wound Healing

Our research group recently demonstrated that pericytes are major sources of the secreted glycoprotein and integrin ligand lactadherin (MFG-E8) in B16 melanoma tumors, and that MFG-E8 promotes angiogenesis via enhanced PDGF–PDGFRβ signaling mediated by integrin–growth factor receptor crosstalk. However, sources of MFG-E8 and its possible roles in skin physiology are not well characterized. The objective of this study was to characterize the involvement of MFG-E8 in skin wound healing. In the dermis of normal murine and human skin, accumulations of MFG-E8 were found around CD31+ blood vessels, and MFG-E8 colocalized with PDGFRβ+, αSMA+, and NG2+ pericytes. MFG-E8 protein and mRNA levels were elevated in the dermis during full-thickness wound healing in mice. MFG-E8 was diffusely present in granulation tissue and was localized around blood vessels. Wound healing was delayed in MFG-E8 knockout mice, compared with the wild type, and myofibroblast and vessel numbers in wound areas were significantly reduced in knockout mice. Inhibition of MFG-E8 production with siRNA attenuated the formation of capillary-like structures in vitro. Expression of MFG-E8 in fibrous human granulation tissue with scant blood vessels was less than that in granulation tissue with many blood vessels. These findings suggest that MFG-E8 promotes cutaneous wound healing by enhancing angiogenesis

Extraction of astatine isotopes for development of radiopharmaceuticals using a 211Rn–211At generator

In order to utilize a 211At isotope, a promising α-emitter for radionuclide therapy, the chemical properties of astatine isotopes are studied. We have examined wet chemistry methods through the distribution ratios of astatine in liquid–liquid extraction. The astatine isotopes have been found to be well extracted into DIPE and MIBK. We observed that the distribution ratio of astatine isotopes increases with concentrations of HCl greater than 3 M, while it decreases with the HCl concentration less than 2 M. The results will be useful for development of the 211Rn–211At generator