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161.
A phytochemical investigation on the ethyl acetate soluble fraction of Lonicera quinquelocularis (whole plant) led to the first time isolation of one new phthalate; bis(7-acetoxy-2-ethyl-5-methylheptyl) phthalate (3) and two new benzoates; neopentyl-4-ethoxy-3, 5-bis (3-methyl-2-butenyl benzoate (4) and neopentyl-4-hydroxy-3, 5-bis (3-methyl-2-butenyl benzoate (5) along with two known compounds bis (2-ethylhexyl phthalate (1) and dioctyl phthalate (2). Their structures were established on the basis of spectroscopic analysis and by comparison with available data in the literature. All the compounds (1–5) were tested for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in dose dependent manner. The IC50 (50% inhibitory effect) values of compounds 3 and 5 against AChE were 1.65 and 3.43 µM while the values obtained against BChE were 5.98 and 9.84 µM respectively. Compounds 2 and 4 showed weak inhibition profile.  相似文献   
162.
The wide occurrence of peristaltic pumping should not be surprising at all since it results physiologically from neuro-muscular properties of any tubular smooth muscle. Of special concern here is to predict the rheological effects on the peristaltic motion in a curved channel. Attention is focused to develop and simulate a nonlinear mathematical model for Carreau-Yasuda fluid. The progressive wave front of peristaltic flow is taken sinusoidal (expansion/contraction type). The governing problem is challenge since it has nonlinear differential equation and nonlinear boundary conditions even in the long wavelength and low Reynolds number regime. Numerical solutions for various flow quantities of interest are presented. Comparison for different flow situations is also made. Results of physical quantities are interpreted with particular emphasis to rheological characteristics.  相似文献   
163.
Manual offline analysis, of a scanning electron microscopy (SEM) image, is a time consuming process and requires continuous human intervention and efforts. This paper presents an image processing based method for automated offline analyses of SEM images. To this end, our strategy relies on a two-stage process, viz. texture analysis and quantification. The method involves a preprocessing step, aimed at the noise removal, in order to avoid false edges. For texture analysis, the proposed method employs a state of the art Curvelet transform followed by segmentation through a combination of entropy filtering, thresholding and mathematical morphology (MM). The quantification is carried out by the application of a box-counting algorithm, for fractal dimension (FD) calculations, with the ultimate goal of measuring the parameters, like surface area and perimeter. The perimeter is estimated indirectly by counting the boundary boxes of the filled shapes. The proposed method, when applied to a representative set of SEM images, not only showed better results in image segmentation but also exhibited a good accuracy in the calculation of surface area and perimeter. The proposed method outperforms the well-known Watershed segmentation algorithm.  相似文献   
164.
165.
Cln3(Δex7/8) mice harbor the most common genetic defect causing juvenile neuronal ceroid lipofuscinosis (JNCL), an autosomal recessive disease involving seizures, visual, motor and cognitive decline, and premature death. Here, to more thoroughly investigate the manifestations of the common JNCL mutation, we performed a broad phenotyping study of Cln3(Δex7/8) mice. Homozygous Cln3(Δex7/8) mice, congenic on a C57BL/6N background, displayed subtle deficits in sensory and motor tasks at 10-14 weeks of age. Homozygous Cln3(Δex7/8) mice also displayed electroretinographic changes reflecting cone function deficits past 5 months of age and a progressive decline of retinal post-receptoral function. Metabolic analysis revealed increases in rectal body temperature and minimum oxygen consumption in 12-13 week old homozygous Cln3(Δex7/8) mice, which were also seen to a lesser extent in heterozygous Cln3(Δex7/8) mice. Heart weight was slightly increased at 20 weeks of age, but no significant differences were observed in cardiac function in young adults. In a comprehensive blood analysis at 15-16 weeks of age, serum ferritin concentrations, mean corpuscular volume of red blood cells (MCV), and reticulocyte counts were reproducibly increased in homozygous Cln3(Δ) (ex7/8) mice, and male homozygotes had a relative T-cell deficiency, suggesting alterations in hematopoiesis. Finally, consistent with findings in JNCL patients, vacuolated peripheral blood lymphocytes were observed in homozygous Cln3(Δ) (ex7/8) neonates, and to a greater extent in older animals. Early onset, severe vacuolation in clear cells of the epididymis of male homozygous Cln3(Δ) (ex7/8) mice was also observed. These data highlight additional organ systems in which to study CLN3 function, and early phenotypes have been established in homozygous Cln3(Δ) (ex7/8) mice that merit further study for JNCL biomarker development.  相似文献   
166.
The serine protease granzyme B (GrB) plays an important role in the immune defense mediated by cytotoxic lymphocytes. Recombinant derivatives of this pro-apoptotic protein fused to tumor-targeting ligands hold promise for cancer therapy, but their applicability may be limited by promiscuous binding to nontarget tissues via electrostatic interactions. Here, we investigated cell binding and specific cytotoxicity of chimeric molecules consisting of wild-type or surface-charge-modified human GrB and the natural EGFR ligand TGFα for tumor targeting. We mutated two cationic heparin-binding motifs responsible for electrostatic interactions of GrB with cell surface structures, and genetically fused the resulting GrBcs derivative to TGFα for expression in the yeast Pichia pastoris . Purified GrBcs-TGFα (GrBcs-T) and a corresponding fusion protein employing wild-type GrB (GrB-T) displayed similar enzymatic activity and targeted cytotoxicity against EGFR-overexpressing breast carcinoma cells in the presence of an endosomolytic reagent. However, unspecific binding of the modified GrBcs-T variant to EGFR-negative cells was dramatically reduced, preventing the sequestration by nontarget cells in mixed cell cultures and increasing tumor-cell specificity. Likewise, modification of the GrB domain alleviated unspecific extracellular effects such as cell detachment indicative of extracellular matrix degradation. Our data demonstrate improved selectivity and functionality of surface-charge-modified GrBcs, suggesting this strategy as a general approach for the development of optimized GrB fusion proteins for therapeutic applications.  相似文献   
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168.
Light color and savory flavor enhancer are attractive for consumers and food producers. The effect of addition time of l ‐cysteine on inhibiting color formation was investigated in soybean peptide‐xylose system, and the possible pathway was explored. Once dicarbonyl compounds were formed during the Maillard reaction, the addition of l ‐cysteine had no color‐inhibiting effect; if l ‐cysteine was added immediately after the Amadori compound was formed, the extraordinary color‐inhibiting effect was observed. Therefore, an improved way to inhibit color formation was proposed on the basis of the interaction of l ‐cysteine and Amadori compounds by controlling the addition time of l ‐cysteine through gradient temperature‐elevating Maillard reaction. The system was heated at 80 °C for 60 min to form Amadori compounds, followed by the addition of L‐cysteine, and the temperature was raised to 120 °C and held for 110 min. Compared with traditional products, the lightest color product was found desirable by GC/MS analysis and sensory evaluation. The novel method proposed can be a guide for the industrial preparation of light‐colored products. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.  相似文献   
169.
The present piece of work highlights the comparative effects of two active forms of brassinosteroids (BRs), 28-homobrassinolide (HBL) and 24-epibrassinolide (EBL), on growth parameters, carbonic anhydrase activity and photosynthetic parameters in Lycopersicon esculentum (cv. K-21) sampled at 45 (24 h after spray) and 60 days after sowing, under natural conditions. Out of the two active forms of BR, EBL proved better than HBL in improving the above parameters, when applied as foliar spray. Of the three concentrations (10−6 M, 10−8 M or 10−10 M) of HBL and EBL, 10−8M proved best in both cases.  相似文献   
170.
Fetal magnetic resonance imaging provides an ideal tool for investigating growth and development of the brain in vivo. Current imaging methods have been hampered by fetal motion but recent advances in image acquisition can produce high signal to noise, high resolution 3-dimensional datasets suitable for objective quantification by state of the art post acquisition computer programs. Continuing development of imaging techniques will allow a unique insight into the developing brain, more specifically process of cell migration, axonal pathway formation, and cortical maturation. Accurate quantification of these developmental processes in the normal fetus will allow us to identify subtle deviations from normal during the second and third trimester of pregnancy either in the compromised fetus or in infants born prematurely.  相似文献   
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