Magnetic-nanoparticle-doped carbogenic nanocomposite: an effective magnetic resonance/fluorescence multimodal imaging probe

A novel and facile approach is developed to synthesize a magnetic nanoparticle (iron oxide)-doped carbogenic nanocomposite (IO-CNC) for magnetic resonance (MR)/fluorescence imaging applications. IO-CNC is synthesized by thermal decomposition of organic precursors in the presence of Fe(3) O(4) nanoparticles with an average size of 6 nm. IO-CNC shows wavelength-tunable fluorescence properties with high quantum yield. Magnetic studies confirm the superparamagnetic nature of IO-CNC at room temperature. IO-CNC shows MR contrast behavior by affecting the proton relaxation phenomena. The measured longitudinal (r(1) ) and transverse (r(2) ) relaxivity values are 4.52 and 34.75 mM(-1) s(-1) , respectively. No apparent cytotoxicity is observed and the nanocomposite shows a biocompatible nature. In vivo MR studies show both T(1) and T(2) * contrast behavior of the nanocomposite. Fluorescence imaging indicates selective uptake of IO-CNC by macrophages in spleen.     

Survival of Streptococcus pyogenes on foods and food contact surfaces

Streptococcus pyogenes causes septic sore throat in millions of Americans each year and may be transmitted from food handlers to food contact surfaces, foods, and consumers. This study examined the individual survival of six S. pyogenes strains on food contact surfaces (plastic and ceramic plates, plastic cups, and stainless steel utensils) held at 21 degrees C for 2 h and on tomatoes stored aerobically at 21 degrees C for 2 h and at 5 degrees C for 24 h. Survival of a cocktail of the six S. pyogenes strains was also evaluated on vacuum-packaged ready-to-eat meats and cheeses held at 21 degrees C for 8 h and at 5 degrees C for 24 h. Populations generally did not change on tomatoes, cheeses, or beef bologna; however, there were small (0.1 to 0.7 log CFU) but statistically significant decreases (P < 0.05) in average S. pyogenes populations on turkey luncheon meat and beef summer sausage stored for 8 h at 21degrees C and on beef summer sausage stored for 24 h at 5 degrees C. On food contact surfaces, average populations either decreased slightly (P > or = 0.05) or remained constant, with the exception of three strains that significantly decreased in number on ceramic plates (P < 0.05; average decreases, 0.3 log CFU). Results of this study suggest the importance of preventing the contamination of foods and food contact surfaces with S. pyogenes by infected workers.     

Preserving boundaries for image texture segmentation using grey level co-occurring probabilities

Texture analysis has been used extensively in the computer-assisted interpretation of digital imagery. A popular texture feature extraction approach is the grey level co-occurrence probability (GLCP) method. Most investigations consider the use of the GLCP texture features for classification purposes only, and do not address segmentation performance. Specifically, for segmentation, the pixels in an image located near texture boundaries have a tendency to be misclassified. Boundary preservation when using the GLCP texture features for image segmentation is important. An advancement which exploits spatial relationships has been implemented. The generated features are referred to as weighted GLCP (WGLCP) texture features. In addition, an investigation for selecting suitable GLCP parameters for improved boundary preservation is presented. From the tests, WGLCP features provide improved boundary preservation and segmentation accuracy at a computational cost. As well, the GLCP correlation statistical parameter should not be used when segmenting images with high contrast texture boundaries.     

Operation kinetics of a DNA-based molecular switch

The influence of temperature variation, salt concentration, and pH on the operation kinetics of a simple DNA-based molecular switch is investigated. The device shows robust behavior over a wide range of temperatures, pH, and salt concentrations. In particular, the device operates well under physiological conditions. The experimental data can be qualitatively understood in terms of the influence temperature, salt concentration, and pH have on DNA strand interactions.     

Azadirachta indica exhibits chemopreventive action against hepatic cancer: Studies on associated histopathological and ultrastructural changes

The present study was designed to evaluate the anticarcinogenic potential of Azadirachta indica against N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis. Further, the associated histopathological and ultrastructural changes were also analyzed. Hepatic cancer model was developed by the intraperitoneal administration of NDEA to mice at weekly intervals, in successive increasing doses, for a period of 8 weeks. Aqueous A. indica leaf extract (AAILE) was administered orally at a dosage of 100 μg/g body weight thrice a week till termination of the study. A relationship between histopathological grading and chemopreventive effect of A. indica had been established at various stages of carcinogenesis. Anticancer activity of A. indica was evaluated in terms of tumor incidence, tumor multiplicity, and survival rate. A significant reduction in tumor incidence (33%), tumor multiplicity (42%), and increase in survival (34%) was observed upon administration of AAILE to NDEA-abused mice. Transmission and scanning electron microscopic investigations showed severe alterations in organelle organization, cellular arrangement, degree of differentiation, cellular metabolism, and morphology of the hepatocytes. These changes appeared to be distinctly delayed upon AAILE supplementation. The results suggest A. indica may have anticancer potential against NDEA-induced hepatic cancer.     

The effects of individual differences and visual instructional aids on disorientation,learning performance and attitudes in a Hypermedia Learning System

Research suggests that certain visual instructional aids can reduce levels of disorientation and increase learning performance in, and positive attitudes towards, HLS for learners with specific individual differences. However, existing studies have looked at only one or two individual differences at a time, and/or considered only a small number of visual instructional aids. No study has considered the impact of the three most commonly studied individual differences – cognitive style, domain knowledge and computer experience – on learning performance, disorientation and attitudes in a HLS incorporating a full range of visual instructional aids. The study reported here addresses this shortcoming, examining the effects of, and between, these three individual differences in relation to learning performance, disorientation and attitudes in two HLS versions: one that incorporated a full set of visual instructional aids and one that did not. Significant effects were found between the three individual differences with respect to disorientation, learning performance and attitudes in the HLS that provided no instructional aids, whereas no such effects were found for the other HLS version. Analysis of the results led to a set of HLS design guidelines, presented in the paper, and the development of an agenda for future research. Limitations of the study and their implications for the generalizability of the findings are also presented.     

PROCESSING AND STORAGE OF CARBONATED GUAVA BEVERAGE

Guava cv.'Allahabad Safeda'was crushed and treated with pectic enzymes at 0.1% concentration (w/v), incubated for 1 h at 40–50C and the liquefied juice having 10.8 Brix and 0. 65% acidity was used for carbonation. The juice was converted into sugar syrup base having 40% guava juice at 40 Brix and 1% acidity. After dosing 50 ml of it into a glass bottle (200ml capacity) filled with chilled (4-6C) carbonated water at 80 psi pressure of CO₂ gas, the bottle was sealed with crown cork and heat processed at 60C for 30 min. The carbonated guava beverage could be stored for 3 months at room (23-41C) and low (3-5C) temperatures and was found acceptable with respect to color, flavor and overall quality. Heat processing improved the flavor of the carbonated guava beverage, and the beverage contained no detectible microbes.     

数字信号控制器实现嵌入式语音应用

在通信领域,改善话音质量和提高话音传输速度是一直以来的要求。在其他市场领域,如消费电子和汽车行业,语音识别正快速成为用户和终端产品交流的标准方法。传统上,这些市场应用主要由集成了数字信号处理器(DSP)和微控制器(MCU)的系统来实现。MCU过去用来录音、回放声音以及控制     

A multidrug resistance transporter from human MCF-7 breast cancer cells

MCF-7/AdrVp is a multidrug-resistant human breast cancer subline that displays an ATP-dependent reduction in the intracellular accumulation of anthracycline anticancer drugs in the absence of overexpression of known multidrug resistance transporters such as P glycoprotein or the multidrug resistance protein. RNA fingerprinting led to the identification of a 2.4-kb mRNA that is overexpressed in MCF-7/AdrVp cells relative to parental MCF-7 cells. The mRNA encodes a 655-aa [corrected] member of the ATP-binding cassette superfamily of transporters that we term breast cancer resistance protein (BCRP). Enforced expression of the full-length BCRP cDNA in MCF-7 breast cancer cells confers resistance to mitoxantrone, doxorubicin, and daunorubicin, reduces daunorubicin accumulation and retention, and causes an ATP-dependent enhancement of the efflux of rhodamine 123 in the cloned transfected cells. BCRP is a xenobiotic transporter that appears to play a major role in the multidrug resistance phenotype of MCF-7/AdrVp human breast cancer cells.     

Detection of chemical warfare agent Nitrogen Mustard-1 based on conducting polymer phthalocyanine nanorod modified electrode

A simple method is reported for the detection of chemical warfare agent Nitrogen Mustard-1 (NM-1) by using a modified electrode which was prepared by electrochemically immobilizing copper phthalocyanine (CuPc) into polypyrrole (pPy) in presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB) during the polymerization of pyrrole in an aqueous solution. The surface of the modified and bare electrodes are characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques in order to know the surface morphology and elemental composition of the modified electrodes, respectively. SEM images indicated the presence of nanorods on pPy/CuPc/CTAB sample and EDS study confirmed the nanorods as CuPc. Moreover, EDS study confirmed that the nanorods are only on the pPy matrix and not inside the pPy. FTIR results confirmed the presence of CuPc in pPy film. AC impedance spectroscopy analysis of the modified electrode with NM-1 exhibited more electron transfer resistance. The prepared modified electrode showed good electrochemical activity with NM-1 when compared to the unmodified gold electrode.