Expandable metal stents for the treatment of colonic obstruction: techniques and outcomes

Modulation of CD8(+) T-cell responses specific for an exogenous antigen by epitope variants would be advantageous to develop a novel means of antigen-specific immune regulation. We have analyzed CD8(+) T-cell responses to single amino acid-substituted variants of a peptide corresponding to residues 142-149 (p142-149; LAYFYPEL) of alphas1-casein, a major milk allergen, which is a dominant determinant restricted by H-2Kb. An analog peptide L142I with a substitution of Ile for Leu at the nonanchor N-terminal residue induced more IFN-gamma secretion than p142-149 from specific CD8(+) T cells. Furthermore, L142I could prime CD8(+) T cells more efficiently in vivo, and these L142I-primed cells secreted more IFN-gamma than p142-149-primed CD8(+) T cells upon stimulation with p142-149 in vitro. These findings are mainly explained by the greater ability of L142I to form stable Kb-peptide complexes. These findings indicate that appropriate analog peptides may be useful as efficient inducers of CD8(+) T cells which recognize the parent peptide and secrete IFN-gamma, a potent inhibitor of Th2-dependent events, including IgE production.     

Effect of alcohol consumption on adult and aged bone: composition, morphology, and hormone levels of a rat animal model

To determine the effect of life-long alcohol consumption on the adult and aged rat model, 4-week-old, female Sprague-Dawley rats were divided into three diet groups. Alcohol-treated animals were fed a modified Lieber-DeCarli diet ad libitum containing 35% ethanol-derived calories, whereas the pair-fed animals (weight-matched to ethanol rats) received an isocaloric liquid diet in which maltose-dextrin substituted calories supplied by ethanol. Chow animals were fed a standard rat chow ad libitum. Proximal tibiae (primarily cancellous bone) and femora (primarily cortical bone) were removed for analysis after 3, 6, 9, 12, or 18 months on the diets. Serum was collected for analysis of calcium levels, the calcium regulating hormones; parathyroid hormone, 25-hydroxyvitamin D, calcitonin, corticosterone, estradiol, testosterone, and IGF-1. Creatinine, SGOT/AST, and SGPT/ALT levels were measured to determine kidney and liver integrity. Previous studies, with young animals, showed that chronic alcohol consumption during the age of bone development reduced bone density and bone mass in both cortical and cancellous bone. The present study demonstrates that these reductions last throughout life, whereas morphological values, such as length and diameter, attain control levels. Calcium regulating hormones and sex hormones are essentially normal and do not appear to be the primary causative agent for adult alcohol-induced osteopenia, but it appears to be due to a more direct effect of alcohol on bone cells.     

用USB启动Windows XP Embedded

Windows XP Embedded Service Pack 2 Feature Pack 2007（以下简称FP2007）推出了用于嵌入式应用的USB启动功能。现在，用户可以通过一个USB闪存驱动器（UFD）、a．k．a．、U盘和USB密钥等来启动并构建一个Windows XPe的映像。构建这种启动Windows XP Embedded的USB设备的过程中，只要直接使用Target Designer，并准备好需要启动的UFD，就像使用ufdprep．exe（FP2007中包含的一个工具）文件一样简单。     

Deflation-based power iteration clustering

Spectral clustering (SC) is currently one of the most popular clustering techniques because of its advantages over conventional approaches such as K-means and hierarchical clustering. However, SC requires the use of computing eigenvectors, making it time consuming. To overcome this limitation, Lin and Cohen proposed the power iteration clustering (PIC) technique (Lin and Cohen in Proceedings of the 27th International Conference on Machine Learning, pp. 655–662, 2010), which is a simple and fast version of SC. Instead of finding the eigenvectors, PIC finds only one pseudo-eigenvector, which is a linear combination of the eigenvectors in linear time. However, in certain critical situations, using only one pseudo-eigenvector is not enough for clustering because of the inter-class collision problem. In this paper, we propose a novel method based on the deflation technique to compute multiple orthogonal pseudo-eigenvectors (orthogonality is used to avoid redundancy). Our method is more accurate than PIC but has the same computational complexity. Experiments on synthetic and real datasets demonstrate the improvement of our approach.     

Maximum likelihood estimation for continuous-time autoregressive models by relaxation on residual variances ratio parameters

In this paper we derive an explicit expression for the log likelihood function of a continuous-time autoregressive model. Then, using earlier results relating the autoregressive coefficients to the set of positive parameters called residual variances ratios, we develop an iterative algorithm for computing the maximum likelihood estimator of the model, similar to one in the discrete-time case. A simple noniterative estimation method, which can be used to produce an initial estimate for the algorithm, is also proposed.     

Parallel Flow Asymmetries in Heat Exchangers

The effect of flow asymmetry was observed experimentally in vertical parallel channels of a continuous direct ohmic heater. While downward-oriented flow is evenly distributed at isothermal conditions, the flow rate in parallel channels differs in the case of heating due to buoyancy effects. Three different configurations of parallel flow (with and without internal heating in channels) are analyzed, giving critical values of Gr/Re or Ri = Gr/Re² and ensuring stable and even distribution of flow into parallel channels of vertically oriented heat exchangers or heaters. Experimental verification was based upon flow visualization (injection of a colored tracer and monitoring the tracer by a camera), measurement of temperature profiles, and stimulus response experiments using KCl as a tracer for conductivity methods (2 Pt conductivity probes) and Tc99 as a radioisotope tracer (collimated scintillation detectors).