Direct Monitoring of γ‐Glutamyl Transpeptidase Activity In Vivo Using a Hyperpolarized 13C‐Labeled Molecular Probe

The γ‐glutamyl transpeptidase (GGT) enzyme plays a central role in glutathione homeostasis. Direct detection of GGT activity could provide critical information for the diagnosis of several pathologies. We propose a new molecular probe, γ‐Glu‐[1‐¹³C]Gly, for monitoring GGT activity in vivo by hyperpolarized (HP) ¹³C magnetic resonance (MR). The properties of γ‐Glu‐[1‐¹³C]Gly are suitable for in vivo HP ¹³C metabolic analysis since the chemical shift between γ‐Glu‐[1‐¹³C]Gly and its metabolic product, [1‐¹³C]Gly, is large (4.3 ppm) and the T₁ of both compounds is relatively long (30 s and 45 s, respectively, in H₂O at 9.4 T). We also demonstrate that γ‐Glu‐[1‐¹³C]Gly is highly sensitive to in vivo modulation of GGT activity induced by the inhibitor acivicin.     

Multiple photofragmentation pathways with different recoil anisotropy from a metal-ion-ligand complex

Spatial recoil anisotropy that is dependent upon the fragment-ion species is reported for the first time for a metal-ion-ligand complex after a single photoexcitation process by linearly polarized light. Upon excitation to the lowest three excited states of Mg+-ICH3, originating from the Mg+2P states, fragment ions of MgI+ and ICH+3 are found to have clear and different angular dependences, which are also characteristic of the excited states. These are explained from the results of theoretical work in that the calculated ground-state complex has a bent structure and further in that each transition dipole moment vector of the complex almost coincides with the Mg+ 3p orbital lobe direction in each case. The fragment ions are concluded to be formed along dissociative potential surfaces which are crossed by the initially excited states, in a much faster process than the rotational period of the complex.     

Normal integral bases and strict ray class groups modulo 4

Let F be a number field. We construct three tamely ramified quadratic extensions which are ramified at most at some given set of finite primes, such that K₃⊂K₁K₂, both K₁/F and K₂/F have normal integral bases, but K₃/F has no normal integral basis. Since Hilbert-Speiser's theorem yields that every finite and tamely ramified abelian extension over the field of rational numbers has a normal integral basis, it seems that this example is interesting (cf. [5] J. Number Theory 79 (1999) 164; Theorem 2). As we shall explain below, the previous papers (Acta Arith. 106 (2) (2003) 171-181; Abh. Math. Sem. Univ. Hamburg 72 (2002) 217-233) motivated the construction. We prove that if the class number of F is bigger than 1, or the strict ray class group of F modulo 4 has an element of order ?3, then there exist infinitely many triplets (K₁,K₂,K₃) of such fields.     

化学计量的氧化钠团簇阳离子结构的离子迁移质谱法研究（英文）

本文通过离子迁移质谱法研究了氧化钠团簇阳离子(Na_nO_m~+,n≤11)的稳定结构.质谱结果表明化学计量组成Na(Na_2O)_((n-1)/2)~+(n=3、5、7、9和11)系列是稳定的,并且NaO(Na_2O)_((n-1)/2)~+(n=5、7、9和11)系列作为二级稳定系列.为了获得这些团簇离子的结构,通过离子迁移率测量实验测定离子和氦缓冲气体之间的碰撞截面.同时计算了这些组合物优化结构的理论碰撞截面.结果表明,Na(Na_2O)_((n-1)/2)~+和NaO(Na_2O)_((n-1)/2)~+的结构除了n=9之外,其它具有相似结构框架.Na(Na_2O)_((n-1)/2)~+所有的化合键位于钠和氧之间.另一方面,NaO(Na_2O)_((n-1)/2)~+中除了Na-O键之外,还存在一个O-O氧键,表明NaO(Na_2O)_((n-1)/2)~+具有过氧化物离子(O_2~(2-))作为Na(Na_2O)_((n-1)/2)~+的氧化物离子(O~(2-))的替代物.Na(Na_2O)_((n-1)/2)~+和NaO(Na_2O)_((n-1)/2)~+两种稳定系列都是闭壳组合物.这些闭壳特征对氧化钠簇阳离子的稳定性具有强烈影响.     

Structure and properties of the 70Li2S · (30 − x)P2S5 · xP2O5 oxysulfide glasses and glass–ceramics

The 70Li₂S · (30 ? x)P₂S₅ · xP₂O₅ (mol%) oxysulfide glasses were prepared by the melt quenching method. The glasses were prepared in the composition range 0 ≦ x ≦ 10. The glass–ceramics were prepared by heating the glasses over crystallization temperatures. The PO_nS_3?n (n = 1–3) oxysulfide units were produced in the glasses and glass–ceramics by partial substituting P₂O₅ for P₂S₅. In particular, the P₂OS₆^4? unit would be produced by substituting a small amount of P₂O₅ for P₂S₅. The oxygen atoms were incorporated into the Li₇P₃S₁₁ crystal structure because the diffraction peaks of the oxysulfide glass–ceramic shifted to the higher angle side. The glass–ceramic with 3 mol% of P₂O₅ exhibited the highest conductivity of 3.0 × 10^?3 S cm^?1 and the lowest activation energy for conduction of 16 kJ mol^?1. The P₂OS₆^4? dimer units in the oxygen-incorporated Li₇P₃S₁₁ crystal would improve conductive behavior of the Li₂S–P₂S₅ glass–ceramics.     

Funds allocation in NPOs: the role of administrative cost ratios

Performance measurement of Non-Profit Organizations (NPOs) is of increasing importance for aid agencies, policy-makers and donors. A widely used benchmark for measuring the efficiency of NPOs is the overhead cost ratio, consisting of the total money spent on administration and fundraising relative to the budget. Donors generally favor a lower overhead cost ratio as it ensures that more money directly reaches beneficiaries. Unlike fundraising expenses, administrative costs do not contribute to advertising the actions of an NPO even though they account for a significant proportion of overhead cost. Reducing administrative expenses is a logical consequence from a financial viewpoint, but might negatively affect NPOs through the resulting administrative capacities. This phenomenon is known as “Nonprofit Starvation Cycle”. This work provides an analytical framework for analyzing NPO decision making concerning administrative costs. The paper provides answers to important research questions on the optimal level of administrative spending, the influencing factors and the effects of available information on NPOs. The research shows that focusing on financial performance measurements can result in reduced utility created for NPOs. Less transparency often leads to increased utility for NPOs, but more transparency can increase NPOs’ utility if the information available exceeds a certain threshold. Fluctuating donations are challenging for NPOs’ planning and may impact administrative capacities negatively.

     

Boron Clusters as Highly Stable Magnesium‐Battery Electrolytes

Boron clusters are proposed as a new concept for the design of magnesium‐battery electrolytes that are magnesium‐battery‐compatible, highly stable, and noncorrosive. A novel carborane‐based electrolyte incorporating an unprecedented magnesium‐centered complex anion is reported and shown to perform well as a magnesium‐battery electrolyte. This finding opens a new approach towards the design of electrolytes whose likelihood of meeting the challenging design targets for magnesium‐battery electrolytes is very high.     

Photon emission from channeled heavy ions excited Resonant-coherently

Abstract

The possibility of the radiative deexcitation from channeled heavy ions excited by the Okorokov Effect (Resonant coherent excitation) is discussed and the experiments on the photon emission due to the deexcitation from hydrogen-like Ne⁹⁺ and Fe⁸⁺ ions are reported.