Characterization of silver nanoparticles prepared by wet chemical method and their antibacterial and cytotoxicity activities

Purpose: To investigate the efficiency of silver nanoparticles synthesized by wet chemical method, and evaluate their antibacterial and anti-cancer activities.Methods: Wet chemical method was used to synthesize silver nanoparticles (AgNPs) from silver nitrate, trisodium citrate dehydrate (C6H5O7Na3.2H2O) and sodium borohydride (NaBH4) as reducing agent. The AgNPs and the reaction process were characterized by UV–visible spectrometry, zetasizer, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The antibacterial and cytotoxic effects of the synthesized nanoparticles were investigated by agar diffusion method and MTT assay respectively.Results: The silver nanoparticles formed were spherical in shape with mean size of 10.3 nm. The results showed good antibacterial properties, killing both Gram-positive and Gram-negative bacteria, and its aqueous suspension displayed cytotoxic activity against colon adenocarcinoma (HCT-116) cell line.Conclusion: The findings indicate that silver nanoparticles synthesized by wet chemical method demonstrate good cytotoxic activity in colon adenocarcinoma (HCT-116) cell lines and strong antibacterial activity against various strains of bacteria.Keywords: Wet chemical, Silver nanoparticles, Characterization, Diffusion method, Antibacterial, Cytotoxic activit

Most vital segment barriers

We study continuous analogues of "vitality" for discrete network flows/paths, and consider problems related to placing segment barriers that have highest impact on a flow/path in a polygonal domain. This extends the graph-theoretic notion of "most vital arcs" for flows/paths to geometric environments. We give hardness results and efficient algorithms for various versions of the problem, (almost) completely separating hard and polynomially-solvable cases

Construction of expression vectors carrying mouse peroxisomal protein gene (PeP) with GST and Flag labels

The aim of this study was to construct expression vectors carrying mouse peroxisomal protein gene (PEP-cDNA) in prokaryotic and mammalian expression vectors in chimeric cDNA types, encompassingGST and FLAG with PEP-cDNA. PEP-cDNA was sub-cloned in pGEX6p2 prokaryotic expression vector in order to label this gene with GST to purify PEP protein for further biochemical analysis and identifying related proteins thereafter. FLAG-PEP recombinant DNA was produced and sub-cloned inpUcD3 eukaryotic expression vector to express tagged-PEP protein for transient transfection analysis and identifying intracellular localization of PEP protein in future experiments. PEP-cDNA was amplifiedin different PCR reactions using pEGFP-PEP vector and 2 sets of primers introducing specific restriction sites at the ends of PEP. PCR products with BamHI/SalI restriction sites were treated by restriction enzymes and inserted into the pGEX6p2, downstream of GST tag. PEP-cDNA containingBamHI/ApaI restriction sites and FLAG gene (which amplified using pUcD3-FLAG-PEX3 vector) were used as templates in secondary PCR for amplifying FLAG-PEP recombinant DNA. FLAG-PEP fragment was treated by enzymatic digestion and inserted into the pUcD3 eukaryotic expression vector.pGEX6p2-PEP and pUcD3-FLAG-PEP constructed vectors were transformed into the one shot TOP10 and JM105 bacterial competent cells, respectively. Positive colonies were selected for plasmid preparation. Results confirmed correct amplification of the expected products. PEP-cDNA in both PCRreactions encompasses 630 bp. FLAG fragment containing designed sites was 77 bp and FLAG-PEP fragment was 700 bp. Sequencing of constructed vectors confirmed that PEP-cDNA was tagged appropriately and inserted free of mutation and in frame with GST and FLAG

New empirical fits to the proton electromagnetic form factors

Recent measurements of the ratio of the elastic electromagnetic form factors of the proton, G_Ep/G_Mp, using the polarization transfer technique at Jefferson Lab show that this ratio decreases dramatically with increasing Q^2, in contradiction to previous measurements using the Rosenbluth separation technique. Using this new high quality data as a constraint, we have reanalyzed most of the world e-p elastic cross section data. In this paper, we present a new empirical fit to the reanalyzed data for the proton elastic magnetic form factor in the region 0 < Q^2 < 30 GeV^2. As well, we present an empirical fit to the proton electromagnetic form factor ratio, G_Ep/G_Mp, which is valid in the region 0.1 < Q^2 < 6 GeV^2

A deep learning approach for human activities recognition from multimodal sensing devices

Research in the recognition of human activities of daily living has significantly improved using deep learning techniques. Traditional human activity recognition techniques often use handcrafted features from heuristic processes from single sensing modality. The development of deep learning techniques has addressed most of these problems by the automatic feature extraction from multimodal sensing devices to recognise activities accurately. In this paper, we propose a deep learning multi-channel architecture using a combination of convolutional neural network (CNN) and Bidirectional long short-term memory (BLSTM). The advantage of this model is that the CNN layers perform direct mapping and abstract representation of raw sensor inputs for feature extraction at different resolutions. The BLSTM layer takes full advantage of the forward and backward sequences to improve the extracted features for activity recognition significantly. We evaluate the proposed model on two publicly available datasets. The experimental results show that the proposed model performed considerably better than our baseline models and other models using the same datasets. It also demonstrates the suitability of the proposed model on multimodal sensing devices for enhanced human activity recognition

Simultaneous lateral and posterior ponticles resulting in the formation of a vertebral artery tunnel of the atlas: case report and review of the literature. Folia Neuropathol

Case report A b s t r a c t The foramen arcuale is infrequently found and is potentially a clinically/surgically significant anatomical variation of the atlas. When present, the vertebral artery travels through this bony ring after exiting the transverse foramen of the atlas and prior to entering the cranium. We present a case of an adult female skeleton noted to harbor both a foramen arcuale and a lateral ponticle that resulted in the formatio

Insights into the Mechanism of Ligand Binding to Octopine Dehydrogenase from Pecten maximus by NMR and Crystallography

Octopine dehydrogenase (OcDH) from the adductor muscle of the great scallop, Pecten maximus, catalyzes the NADH dependent, reductive condensation of L-arginine and pyruvate to octopine, NAD+, and water during escape swimming and/or subsequent recovery. The structure of OcDH was recently solved and a reaction mechanism was proposed which implied an ordered binding of NADH, L-arginine and finally pyruvate. Here, the order of substrate binding as well as the underlying conformational changes were investigated by NMR confirming the model derived from the crystal structures. Furthermore, the crystal structure of the OcDH/NADH/agmatine complex was determined which suggests a key role of the side chain of L-arginine in protein cataylsis. Thus, the order of substrate binding to OcDH as well as the molecular signals involved in octopine formation can now be described in molecular detail

Robust estimation of microbial diversity in theory and in practice

Quantifying diversity is of central importance for the study of structure, function and evolution of microbial communities. The estimation of microbial diversity has received renewed attention with the advent of large-scale metagenomic studies. Here, we consider what the diversity observed in a sample tells us about the diversity of the community being sampled. First, we argue that one cannot reliably estimate the absolute and relative number of microbial species present in a community without making unsupported assumptions about species abundance distributions. The reason for this is that sample data do not contain information about the number of rare species in the tail of species abundance distributions. We illustrate the difficulty in comparing species richness estimates by applying Chao's estimator of species richness to a set of in silico communities: they are ranked incorrectly in the presence of large numbers of rare species. Next, we extend our analysis to a general family of diversity metrics ("Hill diversities"), and construct lower and upper estimates of diversity values consistent with the sample data. The theory generalizes Chao's estimator, which we retrieve as the lower estimate of species richness. We show that Shannon and Simpson diversity can be robustly estimated for the in silico communities. We analyze nine metagenomic data sets from a wide range of environments, and show that our findings are relevant for empirically-sampled communities. Hence, we recommend the use of Shannon and Simpson diversity rather than species richness in efforts to quantify and compare microbial diversity.Comment: To be published in The ISME Journal. Main text: 16 pages, 5 figures. Supplement: 16 pages, 4 figure