Evaluation of the antioxidant and antityrosinase activities of three extracts from Pleurotus nebrodensis fruiting bodies

Pleurotus nebrodensis has been widely used for nutritional and medicinal purposes. The aim of the present study was to evaluate the antioxidant activities and tyrosinase inhibitory effects on the fruiting bodies of P. nebrodensis extracted with acetone, methanol and hot water. The antioxidant activities were performed on - carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferrous ions chelating abilities and xanthine oxidase inhibitory activity. In addition to this, phenolic compounds were also detected. The acetonic and methanolic extracts of P. nebrodensis showed the strongest -carotene-linoleic acid inhibition as compare to hot water extract. At 8 mg/ml, the acetonic extract showed a high reducing power of 1.86. The scavenging activity on DPPH radicals, the acetonic and methanolic extracts were effective than that of hot water extract. At lower concentrations, chelating effect of tested mushroom was significantly effective as compare to positive control. Gallic acid, protocatechuic acid, chlorogenic acid, ferulic acid, naringenin, hesperetin, formononetin and biochanin-A were detected from acetonitrile and hydrochloric acid solvent extract. The xanthine oxidase and tyrosinase inhibitory activities of the acetonic, methanolic and hot water extracts increased with increase of concentration. This study suggests that fruiting bodies of P. nebrodensis can potentially be used as a readily accessible source of natural antioxidants.Key words: Antioxidant, phenolic compounds, Pleurotus nebrodensis, tyrosinase inhibition, xanthine oxidase

Corporate governance and the long-run performance of firms issuing seasoned equity: An Australian study

Corporate governance has been propelled to the forefront of contemporary business thinking by a string of high profile corporate collapses and dramatic regulatory responses in the United States, Australia and in other countries as well. A particularly extensive body of research has emerged surrounding the relationship between corporate governance and firm performance. We combine the governance literature with evidence on the long-term underperformance of firms issuing seasoned equity to examine the benefits of corporate governance in a setting where it is more likely to matter. That is, we address the question, Does good corporate governance mitigate post-issue underperformance? For a broad sample of Australian seasoned equity offerings and employing a comprehensive, self-constructed governance database, we first demonstrate that issuing firms substantially underperform a variety of benchmarks over the long term, confirming similar findings in the existing literature. We then find evidence that better-governed firms do not experience the same degree of post-issue underperformance. Our findings, which are robust to a variety of estimation methods and econometric specifications, are consistent with the windows of opportunity hypothesis and with equity raisings being an important channel through which better corporate governance can improve future performance

Engineering microbialm phenotypes through rewiring of genetic networks

The ability to program cellular behaviour is a major goal of synthetic biology, with applications in health, agriculture and chemicals production. Despite efforts to build ‘orthogonal’ systems, interactions between engineered genetic circuits and the endogenous regulatory network of a host cell can have a significant impact on desired functionality. We have developed a strategy to rewire the endogenous cellular regulatory network of yeast to enhance compatibility with synthetic protein and metabolite production. We found that introducing novel connections in the cellular regulatory network enabled us to increase the production of heterologous proteins and metabolites. This strategy is demonstrated in yeast strains that show significantly enhanced heterologous protein expression and higher titers of terpenoid production. Specifically, we found that the addition of transcriptional regulation between free radical induced signalling and nitrogen regulation provided robust improvement of protein production. Assessment of rewired networks revealed the importance of key topological features such as high betweenness centrality. The generation of rewired transcriptional networks, selection for specific phenotypes, and analysis of resulting library members is a powerful tool for engineering cellular behavior and may enable improved integration of heterologous protein and metabolite pathways

A novel duplication at the putative DNA polymerase alpha arrest site and a founder mutation in Chinese in the IVD gene underlie isovaleric acidaemia

Isovaleric acidaemia is a rare inherited organic acidaemia associated with a characteristic odour in affected patients. Fewer than 40 causative mutations have been reported to date. We report a case in a Hong Kong Chinese neonate who presented with respiratory distress and acute encephalopathy requiring aggressive resuscitation and treatment. Residual gross motor developmental delay was still observed at the age of 16 months. The child was subsequently found to harbour a known missense mutation (c.A1199G [p.Y371C]) and a novel 4-bp duplication (c.1148_1151dupGCTA [p.Y355X]) in the IVD gene. We suggest that the former is a founder mutation in the Chinese population and propose an explanation for the duplication event. Strategies that may achieve early diagnosis and prompt treatment include raising awareness of this condition, implementation of a tandem mass spectrometry neonatal screening programme, and local acquisition of appropriate medications for these metabolic diseases.published_or_final_versio

Competition in the market for takeover advisers

We investigate factors that motivate bidders to engage advisers, we model adviser selection and we test whether value-adding advisers gain market share. Our sample includes 801 attempted takeovers over 1989-1998 in Australia. Our results indicate advisers are likely to be engaged if the takeover deal is large, hostile, and includes non-cash compensation. We find deal completion is not as closely correlated with adviser rankings as does Rau (2000) but we confirm his finding that adviser ranked high on market value of deals advised do not have a comparative advantage in adding value to firms. However, we document some (limited) evidence that value- adding advisers achieve an increase in subsequent deal flow. Our results are consistent with specialization among takeover advisers

Extraction of high-quality DNA from ethanol-preserved tropical plant tissues

BACKGROUND: Proper conservation of plant samples, especially during remote field collection, is essential to assure quality of extracted DNA. Tropical plant species contain considerable amounts of secondary compounds, such as polysaccharides, phenols, and latex, which affect DNA quality during extraction. The suitability of ethanol (96% v/v) as a preservative solution prior to DNA extraction was evaluated using leaves of Jatropha curcas and other tropical species. RESULTS: Total DNA extracted from leaf samples stored in liquid nitrogen or ethanol from J. curcas and other tropical species (Theobroma cacao, Coffea arabica, Ricinus communis, Saccharum spp., and Solanum lycopersicon) was similar in quality, with high-molecular-weight DNA visualized by gel electrophoresis. DNA quality was confirmed by digestion with EcoRI or HindIII and by amplification of the ribosomal gene internal transcribed spacer region. Leaf tissue of J. curcas was analyzed by light and transmission electron microscopy before and after exposure to ethanol. Our results indicate that leaf samples can be successfully preserved in ethanol for long periods (30 days) as a viable method for fixation and conservation of DNA from leaves. The success of this technique is likely due to reduction or inactivation of secondary metabolites that could contaminate or degrade genomic DNA. CONCLUSIONS: Tissue conservation in 96% ethanol represents an attractive low-cost alternative to commonly used methods for preservation of samples for DNA extraction. This technique yields DNA of equivalent quality to that obtained from fresh or frozen tissue

Hypernetwork functional image representation

Motivated by the human way of memorizing images we introduce their functional representation, where an image is represented by a neural network. For this purpose, we construct a hypernetwork which takes an image and returns weights to the target network, which maps point from the plane (representing positions of the pixel) into its corresponding color in the image. Since the obtained representation is continuous, one can easily inspect the image at various resolutions and perform on it arbitrary continuous operations. Moreover, by inspecting interpolations we show that such representation has some properties characteristic to generative models. To evaluate the proposed mechanism experimentally, we apply it to image super-resolution problem. Despite using a single model for various scaling factors, we obtained results comparable to existing super-resolution methods

The comparison of immunomodulatory effects of peripheral mononuclear cells against proliferation in U937 in junior elderly habitual morning swimming in Taiwan cohort

The present investigation was carried out to evaluate the effect of greater immunomodulatory effects of human peripheral blood mononuclear cells against proliferation in human leukemia cells. To achieve this, cells U937 in junior elderly (with cool environmental physical activities) subjects with habitual morning swimming and sedentary lifestyle were recruited in relatively cool season in Taiwan; the isolated human peripheral blood mononuclear cells were stimulated by phytohemagglutinin to obtain the conditioned medium which contains various cytokines. However, the differential effects of the conditioned medium on growth inhibition in U937 leukemia cells were observed. The cytokines, including interferon-gamma, tumor necrosis factors-alpha and interleukine-2 secreted into conditioned medium were higher in the morning-swimming subjects than in the sedentary-lifestyle ones. Similarly, serum white blood cell, creatine phosphokinase, immunoglobulin G and immunoglobulin A in the morning-swimming and sedentary-lifestyle groups indicated that no further inflammatory status existed in the morning-swimming group. In summary, greater immunomodulatory effects of human peripheral blood mononuclear cells against proliferation in human leukemia cells U937 in junior elderly subjects came from the effects of regular moderate exercise in cool temperature rather than of inflammatory effects.Keywords: Immunomodulatory, junior elderly, morning swimming, leukemia, U937, human peripheral blood mononuclear cell

Selenium nanoparticles as candidates for antibacterial substitutes and supplements against multidrug-resistant bacteria

In recent years, multidrug-resistant (MDR) bacteria have increased rapidly, representing a major threat to human health. This problem has created an urgent need to identify alternatives for the treatment of MDR bacteria. The aim of this study was to identify the antibacterial activity of selenium nanoparticles (SeNPs) and selenium nanowires (SeNWs) against MDR bacteria and assess the potential synergistic effects when combined with a conventional antibiotic (linezolid). SeNPs and SeNWs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), zeta potential, and UV-visible analysis. The antibacterial effects of SeNPs and SeNWs were confirmed by the macro-dilution minimum inhibi-tory concentration (MIC) test. SeNPs showed MIC values against methicillin-sensitive S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), vancomycin-resistant S. aureus (VRSA), and vanco-mycin-resistant enterococci (VRE) at concentrations of 20, 80, 320, and >320 μg/mL, respectively. On the other hand, SeNWs showed a MIC value of >320 μg/mL against all tested bacteria. Therefore, MSSA, MRSA, and VRSA were selected for the bacteria to be tested, and SeNPs were selected as the antimicrobial agent for the following experiments. In the time-kill assay, SeNPs at a concentration of 4X MIC (80 and 320 μg/mL) showed bactericidal effects against MSSA and MRSA, respectively. At a concentration of 2X MIC (40 and 160 μg/mL), SeNPs showed bacteriostatic effects against MSSA and bactericidal effects against MRSA, respectively. In the synergy test, SeNPs showed a synergistic effect with linezolid (LZD) through protein degradation against MSSA and MRSA. In conclusion, these results suggest that SeNPs can be candidates for antibacterial substitutes and supplements against MDR bacteria for topical use, such as dressings. However, for use in clinical situations, additional experiments such as toxicity and synergistic mechanism tests of SeNPs are needed

Wearable Internet of Things - from Human Activity Tracking to Clinical Integration

Wearable devices for human activity tracking have been rapidly emerging. Most of them are capable of sending health statistics to smartphones, smartwatches or smart bands. However, they only provide the data for individual analysis and their data is not integrated into clinical practice. Leveraging on the Internet of Things (IoT), edge and cloud computing technologies, we propose an architecture which is capable of providing cloud based clinical services using human activity data. Such services could supplement the shortage of staff in primary healthcare centers thereby reducing the burden on healthcare service providers. The enormous amount of data created from such services could also be utilized for planning future therapies by studying recovery cycles of existing patients. We provide a prototype based on our architecture and discuss its salient features. We also provide use cases of our system in personalized and home based healthcare services. We propose an International Telecommunication Union based standardization (ITU-T) for our design and discuss future directions in wearable IoT