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Homogeneous Sc(OTf)3 used in nitromethane showed excellent catalytic activity for the direct allylation reactions of general alcohols including benzylic, propargylic, allylic, and some aliphatic alcohols with allyltrimethylsilane under mild and neutral reaction conditions. Metal-free β-silyl-substituted carbocations are intermediates generated by the highly oxophilic Sc(OTf)3-assisted rapid removal of a hydroxyl group in alcohols, which is supported by the result that allylation of (R)-1-(naphthalen-2-yl)ethan-1-ol with allytrimethylsilanes using the Sc(OTf)3 catalyst combined with (R)- or (S)-[1,1′-binaphthalene]-2,2′-diol ligands gave only racemic 2-(pent-4-en-2-yl)naphthalene in quantitative yield. The present study resolves the argument about the uncertain catalytic activity of Sc(OTf)3.

An accelerated evaluation method for the SRAM cell write margin is proposed based on the conventional Write Noise Margin (WNM) definition. The WNM is measured under a lower word line voltage than the power supply voltage VDD. A lower word line voltage is used because the access transistor operates in the saturation mode over a wide range of threshold voltage variation. The final WNM at the VDD word line voltage, the Accelerated Write Noise Margin (AWNM), is obtained by shifting the measured WNM at the lower word line voltage. The amount of WNM shift is determined from the WNM dependence on the word line voltage. As a result, the cumulative frequency of the AWNM displays a normal distribution. A normal distribution of the AWNM drastically improves development efficiency, because the write failure probability can be estimated by a small number of samples. Effectiveness of the proposed method is verified using the Monte Carlo simulation. © 2011 IEEE.

The sigma (σ) factor is a subunit for the RNA polymerase (RNAP) holoenzyme and can confer promoter selectivity at a target gene. On the inactivation of all group 2 and 3 σ factor genes, expression at the level of the transcript and protein was examined under continuous white light at an exponential phase in a unicellular cyanobacterium, Synechocystis sp. strain PCC 6803. It was found that interference expression exists among group 1, 2, and 3 σ factor genes. Authentic echoes of the expression did not always reflect correlations between the transcript and protein levels. Linkages for the expression network of the σ factors were summarized and unique properties discussed.

In drug discovery, the cerebrospinal fluid (CSF) drug concentration (CCSF) has been used as a surrogate for the interstitial fluid (ISF) concentration (CISF). However, the CCSF-to-CISF gradient suggested for P-glycoprotein (P-gp) substrates in rodents causes uncertainty in CISF estimations and subsequent pharmacokinetic-pharmacodynamic analyses. To evaluate the utility of CCSF as a surrogate for CISF, this study directly compared the CCSF with the CISF of 12 compounds, including P-gp substrates, under steady-state conditions in wild-type and Mdr1a(−/−) rats using microdialysis coupled with cisternal CSF sampling. In wild-type rats, the ISF-to-unbound plasma (Kp,uu,ISF) and CSF-to-unbound plasma (Kp,uu,CSF) concentration ratios of the P-gp substrates, except for metoclopramide, were lower than those of the non-P-gp substrates, and the Kp,uu,CSF values were within or close to 3-fold of the Kp,uu,ISF values for all the compounds examined. The Kp,uu,CSF values of the selected P-gp substrates increased in Mdr1a(−/−) rats with a similar magnitude to the Kp,uu,ISF values, resulting in the Kp,uu,CSF-to-Kp,uu,ISF ratios being unchanged. These results suggested that P-gp-mediated active efflux at the blood–brain barrier is a major determinant not only for CISF, but also for CCSF, and that CCSF can be used as a surrogate for CISF even for P-gp substrates in rats.