In-vitro cytotoxicity of biosynthesized gold nanoparticles against thyroid cancer cell lines

Purpose: To undertake the biosynthesis of gold nanoparticles (AuNPs) using Shorea tumbuggaia bark extract and to study their in-vitro cytotoxicity in thyroid cancer (SW579) cell lines.Methods: AuNPs were prepared by adding 10 mL of Shorea tumbuggaia extract to 5 mL of 2 × 10-3 M of chloroauric acid (HAuCl4) and stirred at room temperature for about 20 min. The AuNPs were evaluated by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV–Vis) spectroscopy and transmission electron microscopy (TEM). They were also assessed for cytotoxicity against SW579 cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.Results: The reaction of Shorea tumbuggaia extract with HAuCl4 led to a change in the color of the reaction solution to ruby red after 20 min, indicating the formation of AuNPs. The results of various instrumental tests, including XRD, TEM, UV–vis spectroscopy and FT-IR spectroscopy confirmed the formation of AuNPs. TEM images showed spherical NPs with a mean particle size of 20 nM. Further, in vitro cytotoxicity results indicated concentration-dependent cytotoxicity against SW579 cell lines.Conclusions: A simple, green and low-cost method for the preparation of AuNPs using Shorea tumbuggaia extract has been achieved. The AuNPs exert cytotoxic activity against SW579 cell lines.Keywords: Shorea tumbuggaia, Polyphenols, Gold nanoparticles, Cytotoxicity, Thyroid cancer cel

First report on the occurrence of Rickettsia slovaca and Rickettsia raoultii in Dermacentor silvarum in China

10.1186/1756-3305-5-19Parasites and Vectors511

Price competition between shrink-wrap software and cloud service firms under a stochastic model

The authors establish a stochastic model of the price competition between shrink-wrap software and cloud service firms. They show that cloud service firms earn higher profits, but face higher risks compared to shrink-wrap software firms. In order to attract customers and earn higher profits, the authors obtain the result that shrink-wrap software firms need to focus on pricing strategies, by contrast, cloud service firms need to focus on quantity strategie

Affinity purification of recombinant human plasminogen activator from transgenic rabbit milk using a novel polyolresponsive monoclonal antibody

Purpose: To develop processes for effective isolation and purification of recombinant human plasminogen activator (rhPA) from transgenic rabbit milk.Methods: Immunoaffinity chromatography was selected and improved by a special polyol-responsive monoclonal antibody (PR-mAb). Alteplase was used as immunogen because of its similarity to rhPA in terms of structure. The PR-mAb was prepared by hybridoma technology and screened by ELISA-elution assay. Screening antibody was performed using rhPA milk in an ELISA-elution assay. The antibody clone C4-PR-mAb was selected for immunoaffinity chromatography. The rhPA was effectively bound to immobilized C4-PR-mAb on the column and was eluted with Tris buffer comprising 0.75 mol/L ammonium sulfate and 40n% propanediol (pH7.9). The rhPA was further purified by passing through Chromdex75 gel filtration column.Results: There were 12 hybridoma strains selected into the polyol responsive mAbs screen step and three hybridoma strains were superior for producing PR-mAbs (C1, C4, C8). The rhPA can be purified from transgenic rabbit milk and maintained a higher thrombolytic activity in vitro by FAPA.Conclusion: The results demonstrate the suitability of the alternative approach used in this study. Using immunoaffinity chromatography and  gel filtration column is feasible and convenient for extracting rhPA from milk, and should be useful for purifying other tPA mutants or other novel recombinant milkderived proteins.Keywords: tPA, Immunoaffinity chromatography, PR-mAb, ELISA-elution, Antibody, Thrombolytic activit

Mid-infrared Spectral Compression of Soliton Pulse in an Adiabatically Suspended Silicon Waveguide Taper

Spectral compression (SPC) can be used for generating narrow bandwidth and wavelength-tunable light sources, which have important applications in optical communication system, spectroscopy, and nonlinear microscopy. In this paper, we numerically demonstrate the high-degree SPC of the chirp-free femtosecond pulse at wavelength 2.4 μm in a 6-cm long adiabatically suspended silicon waveguide taper. The silicon waveguide taper is designed with a dispersion-increasing profile along the propagation distance z. Simulation results show that the SPC factor can be up to 10.9, along with the brightness-enhanced factor of 8.0 and negligible sidelobe. The impacts of the higher-order dispersion, higher-order nonlinearity, losses (including linear and nonlinear loss), and variation of Kerr nonlinear coefficient along z on the SPC are also investigated. It is found that variation of Kerr nonlinear coefficient γ(z) and linear loss are the dominant perturbation to the degradation of the SPC performance

Perovskite and organic solar cells fabricated by inkjet printing: progress and prospects

Inkjet printing (IJP) technology, adapted from home and office printing, has proven to be an essential research tool and industrial manufacturing technique in a wide range of printed electronic technologies, including optoelectronics. Its primary advantage over other deposition methods is the low-cost and maskless on-demand patterning, which offers unmatched freedom-of-design. Additional benefits include the efficient use of materials, contactless high-resolution deposition, and scalability, enabling rapid translation of learning from small-scale, laboratory-based research into large-scale industrial roll-to-roll manufacturing. In the development of organic solar cells (OSCs), IJP has enabled the printing of many of the multiple functional layers which comprise the complete cell as part of an additive printing scheme. Although IJP is only recently employed in perovskite solar cell (PeSC) fabrication, it is already showing great promise and is anticipated to find broader application with this class of materials. As OSCs and PeSCs share many common functional materials and device architectures, this review presents a progress report on the IJP of OSCs and PeSCs in order to facilitate knowledge transfer between the two technologies, with critical analyses of the challenges and opportunities also presented

Spinocerebellar ataxia type 8 larger triplet expansion alters histone modification and induces RNA foci

<p>Abstract</p> <p>Background</p> <p>Spinocerebellar ataxia type 8 (SCA8) involves the expression of an expanded CTG/CAG combined repeats (CR) from opposite strands producing CUG expansion transcripts (ataxin 8 opposite strand, ATXN8OS) and a polyglutamine expansion protein (ataxin 8, ATXN8). The pathogenesis of SCA8 is complex and the spectrum of clinical presentations is broad.</p> <p>Results</p> <p>Using stably induced cell models expressing 0, 23, 88 and 157 CR, we study the role of ATXN8OS transcripts in SCA8 pathogenesis. In the absence of doxycycline, the stable ATXN8OS CR cell lines exhibit low levels of ATXN8OS expression and a repeat length-related increase in staurosporine sensitivity and in the number of annexin positive cells. A repeat length-dependent repression of ATXN8OS expression was also notable. Addition of doxycycline leads to 25~50 times more ATXN8OS RNA expression with a repeat length-dependent increase in fold of ATXN8OS RNA induction. ChIP-PCR assay using anti-dimethyl-histone H3-K9 and anti-acetyl-histone H3-K14 antibodies revealed increased H3-K9 dimethylation and reduced H3-K14 acetylation around the ATXN8OS cDNA gene in 157 CR line. The repeat length-dependent increase in induction fold is probably due to the increased RNA stability as demonstrated by monitoring ATXN8OS RNA decay in cells treated with the transcriptional inhibitor, actinomycin D. In cells stably expressing ATXN8OS, RNA FISH experiments further revealed ribonuclear foci formation in cells carrying expanded 88 and 157 CR.</p> <p>Conclusion</p> <p>The present study demonstrates that the expanded CUG-repeat tracts are toxic to human cells and may affect ATXN8OS RNA expression and stability through epigenetic and post-transcriptional mechanisms.</p

Linking transformational leadership and core self-evaluation to job performance: The mediating role of felt accountability

The present study examines the mediating effects of felt accountability on the relationship of both transformational leadership as well as core self-evaluation on task and contextual performance. SEM with AMOS was used to analyze the data collected from questionnaires distributed to 302 supervisor-employee dyads. The concept of felt accountability is based on a social contingency model of accountability, which is distinct from the feelings of responsibility or obligation in organizational research. Our hypotheses of the mediating roles of felt accountability were supported by the data, except that the mediating effect of felt accountability between the relationship of core self-evaluation and contextual performance was not supported. We discuss the implications of these results for research and practice in organizations