The role of the peripheral benzodiazepine receptor in the apoptotic response to photodynamic therapy

Several previous studies have suggested that the peripheral benzodiazepine receptor (PBR) on the mitochondrial surface was an important target for photodynamic therapy (PDT). In this study we compared PBR affinity vs photodynamic efficacy of protoporphyrin-IX (PP-IX) and two structural analogs, PP-III and PP-XIII, using murine leukemia L1210 cells in culture. The results indicate that the three agents have approximately equal hydrophobicity, affinity for L1210 cells and ability to initiate photodamage leading to an apoptotic response. But only PPIX had significant affinity for the PBR. These data indicate that the relationship between PDT efficacy and PBR affinity may hold only for sensitizers with the PP-IX configuration

L1 LASSO and its Bayesian Inference

A new iterative procedure for solving regression problems with the so-called LASSO penalty is proposed by using generative Bayesian modeling and inference. The algorithm produces the anticipated parsimonious or sparse regression models that generalize well on unseen data. The proposed algorithm is quite robust and there is no need to specify any model hyperparameters. A comparison with state-of-the-art methods for constructing sparse regression models such as the relevance vector machine (RVM) and the local regularization assisted orthogonal least squares regression (LROLS) is given

Liquid chromatography-mass spectrometry (LC-MS) investigation of the thiobarbituric acid reactive substances (TBARS) reaction

The thiobarbituric acid reactive substances (TBARS) assay is a commonly used method for the detection of lipid peroxidation. Malondialdehyde is formed as a result of lipid peroxidation and reacts with thiobarbituric acid to form a pink pigment that has an absorption maximum at 532 nm. Other compounds also react with thiobarbituric acid to form colored species that can interfere with this assay, but little is known about these interfering species. This is the first investigation using LC-MS and MS-MS to study the structures of the pink adduct as well as a common unstable yellow interference compound, which absorbs at 455 nm. Also, the presence of barbituric acid impurities in the thiobarbituric acid reagent was found to produce 1:1:1 thiobarbituric acid/malondialdehyde/barbituric acid and 2:1 barbituric acid/malondialdehyde adducts that absorbed at 513 and 490 nm, respectively, indicating that thiobarbituric acid should be purified before use.5 page(s

UND: unite-and-divide method in Fourier and Radon domains for line segment detection

In this paper, we extend our previously proposed line detection method to line segmentation using a so-called unite-and-divide (UND) approach. The methodology includes two phases, namely the union of spectra in the frequency domain, and the division of the sinogram in Radon space. In the union phase, given an image, its sinogram is obtained by parallel 2D multilayer Fourier transforms, Cartesian-to-polar mapping and 1D inverse Fourier transform. In the division phase, the edges of butterfly wings in the neighborhood of every sinogram peak are firstly specified, with each neighborhood area corresponding to a window in image space. By applying the separated sinogram of each such windowed image, we can extract the line segments. The division Phase identifies the edges of butterfly wings in the neighborhood of every sinogram peak such that each neighborhood area corresponds to a window in image space. Line segments are extracted by applying the separated sinogram of each windowed image. Our experiments are conducted on benchmark images and the results reveal that the UND method yields higher accuracy, has lower computational cost and is more robust to noise, compared to existing state-of-the-art methods

First syntheses of fused pyrroloporphyrins

(2-Nitro-5,10,15,20-tetraphenylporphyrinato)nickel(II) reacts with α-isocyanoacetic esters in the presence of DBU to give the first β-fused pyrroloporphyrins, the pyrrole ring in the fused system being shown to undergo typical pyrrole-type chemistry; the corresponding zinc(II) complex affords a novel cyclopropanochlorin (characterized by X-ray crystallography), when treated with an α-isocyanoacetic ester