Temporal profile curves for calcium transients during single twitch activation (A) and tetanic stimulation (B).

<p>Each line corresponds to the average of all single fiber measurements that have been included in the statistical analysis. For improving the visibility of group differences, the time interval was adjusted accordingly. The red and black dashed lines indicate the drift of the baseline calcium during the tetanic stimulation. Treatment of fibers with 25 μM FK506 (red line) leads to an elevated inter-peak-baseline level compared to untreated control fibers (black line). </p

Energy utilization in FDB fibers.

<p>The graph shows the estimates for the relative baseline change ± SEM after different treatment conditions (pretreatment/injection). Changes, displayed in %, are statistically valuated by the corresponding p-value. The increased SERCA activity observed after FK506 injection can be incompletely normalized by pretreatment with JTV-519.</p

Photoinduced Brook-Type Rearrangement of Acylcyclopolysilanes

Previously unknown 1,1,4-tris­(trimethylsilyl)-4-acyldodecamethylcyclohexasilanes (Me₃Si)₂Si₆Me₁₂(Me₃Si)­COR (<b>16a</b>, R = <i>tert</i>-butyl; <b>16b</b>, R = 1-adamantyl) have been synthesized by the reaction of the potassium silanides (Me₃Si)₂Si₆Me₁₂(Me₃Si)K with acid chlorides ClCOR, and their photochemical rearrangement reactions have been studied. The molecular structures of <b>16a</b>,<b>b</b> as determined by single-crystal X-ray diffraction analysis exhibit an unusual twist-boat conformation of the cyclohexasilane ring. When <b>16a</b>,<b>b</b> were photolyzed with λ >300 nm radiation, they underwent Brook type 1,3-Si → O migration reactions to generate the cyclohexasilanes <b>17a</b>,<b>b</b> with exocyclic SiC bonds along with smaller amounts of the ring-enlarged species <b>19a</b>,<b>b</b> with endocyclic SiC double bonds. While <b>17a</b>,<b>b</b> were stable enough to allow characterization by NMR and UV absorption spectroscopy, the less stable products <b>19a</b>,<b>b</b> could only be observed in the form of their methanol adducts

The graph shows the estimates for the AUC (mean±SEM) for the four groups.

<p>Changes, displayed in %, are statistically valuated by the corresponding p-value. n: number of fibers measured per group. Control (n=42), FK506 (n=42), JTV-519 (n=53) and JTV-519 + FK506 (n= 44).</p

Stable Silenolates and Brook-Type Silenes with Exocyclic Structures

The first silenolates with exocyclic structures [(Me₃Si)₂Si­(Si₂Me₄)₂SiC­(R)­O]⁻K⁺ (<b>2a</b>: R = 1-adamantyl; <b>2b</b>: mesityl; <b>2c</b>: <i>o</i>-tolyl) were synthesized by the reaction of the corresponding acylcyclohexasilanes <b>1a</b>–<b>c</b> with KO<i>t</i>Bu. NMR spectroscopy and single-crystal X-ray diffraction analysis suggest that the aryl-substituted silenolates <b>2b</b>,<b>c</b> exhibit increased character of functionalized silenes as compared to the alkyl-substituted derivative <b>2a</b> due to the different coordination of the K⁺ counterion to the SiC­(R)O moiety. <b>2b</b>,<b>c</b>, thus, reacted with ClSi<i>i</i>Pr₃ to give the exocyclic silenes (Me₃Si)₂Si­(Si₂Me₄)₂SiC­(OSi<i>i</i>Pr₃)­R (<b>3b</b>: R = Mes; <b>3c</b>: <i>o</i>-Tol), while <b>2a</b> afforded the Si-silylated acylcyclohexasilane <b>1d</b>. The thermally remarkably stable compound <b>3b</b>, which is the first isolated silene with the sp² silicon atom incorporated into a cyclopolysilane framework, could be fully characterized structurally and spectroscopically