Biosynthesis,characterization and cytotoxic activity of CeO2 nanoparticles

Cerium oxide nanoparticles (CeO₂-NPs) have been biosynthesized using the aqueous extract of aerial parts of Prosopis farcta. This plant contains phenolic compounds that function as reducing and capping agents. Biosynthesized particles have been characterized through the use of UV–vis, PXRD, TEM, FESEM, EDX, Raman and FTIR analysis. The UV–vis spectrum clearly showed absorption peak at 317?nm, which indicated the formation of spherical CeO₂-NPs. It displayed in the FESEM and TEM images that the biosynthesized particles are uniformly and spherically shaped with a size of about 30?nm, while the EDX has clearly shown that only the elements Ce and O are present in the biosynthesized sample. Moreover, the Raman spectrum of synthesized nanoparticles has displayed a Ce-O stretching band at a measurement of 459?cm^?1. The cytotoxic activity of biosynthesized nanoparticles against the HT-29 cancer cell line was studied using the MTT assay. All the concentrations of CeO₂-NPs (0–800?µg/ml) showed non-toxic effects and thus, it can be suggested that these nanoparticles have the potential of being utilized in various fields of medicine, such as drug delivery.     

Remember-Know and source memory instructions can qualitatively change old-new recognition accuracy: The modality-match effect in recognition memory.

Remember-Know (RK) and source memory tasks were designed to elucidate processes underlying memory retrieval. As part of more complex judgments, both tests produce a measure of old-new recognition, which is typically treated as equivalent to that derived from a standard recognition task. The present study demonstrates, however, that recognition accuracy can be qualitatively changed by a RK or source-retrieval orientation. Visual and auditory presentations of words were varied at encoding and at test. The memory test was either a standard (old-new) recognition test, the RK test, or a source (modality) test. No effect of modality match was found on standard recognition. However, recognition accuracy in the RK and modality tests was greater when study and test modalities matched—a result obtained for both 1-step (e.g., R, K, or new?) and 2-step (e.g., old-new decision followed by RK decision for items judged old) versions of these tests. Thus, the RK and source (modality) memory procedures produced a measure of old-new recognition that was qualitatively different than standard recognition, having a greater sensitivity to perceptual information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retinal image analysis using curvelet transform and multistructure elements morphology by reconstruction

Retinal images can be used in several applications, such as ocular fundus operations as well as human recognition. Also, they play important roles in detection of some diseases in early stages, such as diabetes, which can be performed by comparison of the states of retinal blood vessels. Intrinsic characteristics of retinal images make the blood vessel detection process difficult. Here, we proposed a new algorithm to detect the retinal blood vessels effectively. Due to the high ability of the curvelet transform in representing the edges, modification of curvelet transform coefficients to enhance the retinal image edges better prepares the image for the segmentation part. The directionality feature of the multistructure elements method makes it an effective tool in edge detection. Hence, morphology operators using multistructure elements are applied to the enhanced image in order to find the retinal image ridges. Afterward, morphological operators by reconstruction eliminate the ridges not belonging to the vessel tree while trying to preserve the thin vessels unchanged. In order to increase the efficiency of the morphological operators by reconstruction, they were applied using multistructure elements. A simple thresholding method along with connected components analysis (CCA) indicates the remained ridges belonging to vessels. In order to utilize CCA more efficiently, we locally applied the CCA and length filtering instead of considering the whole image. Experimental results on a known database, DRIVE, and achieving to more than 94% accuracy in about 50 s for blood vessel detection, proved that the blood vessels can be effectively detected by applying our method on the retinal images.     

Imaging food freezing using X-ray microtomography

X‐ray micro‐computed tomography (X‐ray micro‐CT) has been applied to visualise ice crystal structures formed during freezing of a number of foods. Materials were frozen unidirectionally at ?5 °C and then freeze‐dried to remove the ice crystal structure and leave voids that can be measured by the X‐ray. The system reconstructs the 3‐D image based on a set of 2‐D images, and is capable of micrometre‐scale visualisation. This study demonstrates the capability of the technique to characterise the internal ice crystal microstructure of a range of frozen materials; meat, fish, chicken, potato, cheese and carrot. Results show the voids corresponding to the ice crystals formed within these materials at different directions to the heat flux and various axial positions. Electron microscopy of the same materials, both fresh and frozen at ?5 °C, indicates the same shape of voids seen by the tomographic technique. Ice crystal parameters such as size, area and width can be quantified by the technique. Ice crystals in carrot were larger than in the other materials, while cheese and potato had the lowest values. The ice crystal distribution of all the experimental materials varied with axial distance from cooling surface; the closer the measurement was to the cooling surface, the smaller the crystal size. The results demonstrate that X‐ray micro‐CT might be useful in the analysis of frozen foods.     

Blocking the PCNA/NKp44 Checkpoint to Stimulate NK Cell Responses to Multiple Myeloma

Simple SummaryMembrane-associated PCNA is expressed on the surface of human MM cell lines and primary MM cells. Mab 14-25-9 interacts with membrane-associated PCNA and blocks its binding to NK-expressed NKp44, thus activating NK function. We showed that mAb 14-25-9 can serve as an immune checkpoint blocker, enhancing the function of NK cells on target human MM cell lines and primary cells.AbstractMultiple Myeloma (MM) is a devastating malignancy that evades immune destruction using multiple mechanisms. The NKp44 receptor interacts with PCNA (Proliferating Cell Nuclear Antigen) and may inhibit NK cells’ functions. Here we studied in vitro the expression and function of PCNA on MM cells. First, we show that PCNA is present on the cell membrane of five out of six MM cell lines, using novel anti-PCNA mAb developed to recognize membrane-associated PCNA. Next, we stained primary bone marrow (BM) mononuclear cells from MM patients and showed significant staining of membrane-associated PCNA in the fraction of CD38⁺CD138⁺ BM cells that contain the MM cells. Importantly, blocking of the membrane PCNA on MM cells enhanced the activity of NK cells, including IFN-γ-secretion and degranulation. Our results highlight the possible blocking of the NKp44-PCNA immune checkpoint by the mAb 14-25-9 antibody to enhance NK cell responses against MM, providing a novel treatment option.     

Through a narrow window: Sample size and the perception of correlation.

A theoretical analysis (Y. Kareev, 1995b) of the sampling distribution of correlations led to the surprising conclusion that the use of small samples has a potential advantage for the early detection of a correlation. This is so because the distribution is highly skewed, and the smaller the sample size, the more the distribution is skewed. This article describes 2 experiments that were designed as empirical tests of this conclusion. In Experiment 1 (N?=?112), the authors compared the predictions of participants differing in their working-memory capacity (hence in the size of the samples they were likely to consider). In Experiment 2 (N?=?144), the authors compared the predictions of participants who viewed samples of different sizes, whose size was determined by the authors. The results fully supported Y. Kareev's conclusion: In both experiments, participants with lower capacity (or smaller samples) indeed perceived the correlation as more extreme and were more accurate in their predictions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modified distributed arithmetic based architecture for discrete wavelet transforms

A highly area-efficient multiplier-less filterbank architecture for one-and two-dimensional discrete wavelet transforms (DWT) is presented. The look-up table (LUT) structure in traditional distributed arithmetic (DA)-based filter structures has been dissolved to implement a LUT-less DA-DWT with dual filterbanks, which permits the reuse of the same circuitry for both highpass and lowpass filters.