Observation of Cabibbo suppressed B --> D(*)K- decays at Belle

We report observations of the Cabibbo suppressed decays B-->D((*))K- using a 10.4 fb(-1) data sample accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. We find that the ratios of Cabibbo suppressed to Cabibbo favored branching fractions are B(B--->D0K-)/B(B--->D0pi(-)) = 0.079+/-0.009+/-0.006, B(B(0)-->D+K-)/B(B(0)-->D+pi(-)) = 0.068+/-0.015+/-0.007, B(B--->D(*0)K-)/B(B--->D(*0)pi(-)) = 0.078+/-0.019+/-0.009, and B(B(0)-->D(*+)K-)/B(B(0)-->D(*+)pi(-)) = 0.074+/-0.015+/-0.006. These are the first observations of the B-->D+K-, D(*0)K-, and D(*+)K- decay processes.     

Existence and uniqueness for Legendre curves

We give a moving frame of a Legendre curve (or, a frontal) in the unit tangent bundle and define a pair of smooth functions of a Legendre curve like as the curvature of a regular plane curve. It is quite useful to analyse the Legendre curves. The existence and uniqueness for Legendre curves hold similarly to the case of regular plane curves. As an application, we consider contact between Legendre curves and the arc-length parameter of Legendre immersions in the unit tangent bundle.     

Structural study of (Li2S)50(GeS2)50 glass by X-ray and neutron diffraction

(Li₂S)₅₀(GeS₂)₅₀ glass was characterized by high-energy X-ray diffraction. The results were compared with previous neutron diffraction data. Moreover, Reverse Monte Carlo (RMC) modeling was performed using the X-ray and neutron data in order to obtain a three-dimensional structural model. The RMC model showed that the Ge–S framework structure was formed mainly by the connection of corner-sharing GeS₄ tetrahedra. Furthermore, many lithium ions were coordinated by three non-bridging sulfurs and one bridging sulfur.     

All 4-Edge-Connected HHD-Free Graphs are {\mathbb{Z}_3}-Connected

An undirected graph G = (V, E) is called \mathbbZ₃{\mathbb{Z}_3}-connected if for all b: V ? \mathbbZ₃{b: V \rightarrow \mathbb{Z}_3} with ?_{v ? V}b(v)=0{\sum_{v \in V}b(v)=0}, an orientation D = (V, A) of G has a \mathbbZ₃{\mathbb{Z}_3}-valued nowhere-zero flow f: A? \mathbbZ₃-{0}{f: A\rightarrow \mathbb{Z}_3-\{0\}} such that ?_{e ? d⁺(v)}f(e)-?_{e ? d^-(v)}f(e)=b(v){\sum_{e \in \delta^+(v)}f(e)-\sum_{e \in \delta^-(v)}f(e)=b(v)} for all v ? V{v \in V}. We show that all 4-edge-connected HHD-free graphs are \mathbbZ₃{\mathbb{Z}_3}-connected. This extends the result due to Lai (Graphs Comb 16:165–176, 2000), which proves the \mathbbZ₃{\mathbb{Z}_3}-connectivity for 4-edge-connected chordal graphs.     

Einen Saugfiltrierapparat

Ohne Zusammenfassung     

Polyamides from 2,6,(7)-diamino-9,10-dihydro-9,10-ethanoanthracene and 2,6,(7)-diaminoanthracene

High-molecular-weight, film-forming, amorphous polyamides have been prepared from 2,6(7)-diamino-9,10-dihydro-9,10-ethanoantracene with adipic, sebacic, dodecanoic, isophthalic, 4,4′-oxybibenzoic, 2,6-naphthoic, 4,4′-bibenzoic, and terephthalic acid. Thermal elimination of ethylene from these polymers has yielded the corresponding polyamides from 2,6(7)-diaminoanthracene which were of high molecular weight, film forming, and crystalline.     

Efficient Total Synthesis of Bongkrekic Acid and Apoptosis Inhibitory Activity of Its Analogues

Bongkrekic acid (BKA), isolated from the bacterium Burkholderia cocovenenans, is an inhibitor of adenine nucleotide translocator, which inhibits apoptosis, and is thus an important tool for the mechanistic investigation of apoptosis. An efficient total synthesis of BKA has been achieved by employing a three‐component convergent strategy based on Kocienski–Julia olefination and Suzuki–Miyaura coupling. It is noteworthy that segment B has been prepared as a new doubly functionalized coupling partner, which contributes to shortening of the number of steps. Torquoselective olefination with an ynolate has also been applied for the efficient construction of an unsaturated ester. Furthermore, it is revealed that 1‐methyl‐2‐azaadamantane N‐oxyl is an excellent reagent for final oxidation to afford BKA in high yield. Based on the total synthesis, several BKA analogues were prepared for structure–activity relationship studies, which indicated that the carboxylic acid moieties were essential for the apoptosis inhibitory activity of BKA. More easily available BKA analogues with potent apoptosis inhibitory activity were also developed.