Chromatographic-mass spectrometric analysis of ethanol extract of Maesa perlaria var formosana

Purpose: This study analyzes the chemical composition of ethanol root extracts of Maesa perlaria var. formosana by gas chromatography-mass spectrometry (GC-MS).Methods: The dried root of Maesa perlaria var. formosana was extracted with 95 % ethanol for composition analysis under the following optimum GC-MS conditions: 250 °C inlet temperature, 250 °C MSD detector temperature, and GC oven temperature programmed as follows: initial temperature held at 70 °C for 15 min, then increased at a rate of 2.5 °C/min and held at 170 °C for 15 min; then raised at a rate of 2 °C/min and kept at 180 °C for 20 min; then raised at 2 °C/min and kept at 250 °C for 20 min. Finally, it was raised at 3 °C/min and kept at 280 °C for 15 min.Results: A total of 59 chemical compounds were identified, representing 88.82 % of the composition of the ethanol extracts. The three major components, include 2,4-di-tert-butylphenol (16.76 %), stigmasterol (15.86 %) and campesterol (7.33 %)Conclusion: The results show that a total of 59 components were identified in the ethanol extract of Maesa perlaria var. formosana. The major component, 2,4-Di-tert-butylphenol, exhibits various biological activities.Keywords: Maesa perlaria var. formosana, 2,4-Di-tert-butylphenol, Stigmasterol, Campesterol, Gas chromatography-mass spectrometr

Complexities in financial network topological dynamics: modeling of emerging and developed stock markets

Policy makings and regulations of financial markets rely on a good understanding of the complexity of financial markets. There have been recent advances in applying data-driven science and network theory into the studies of social and financial systems. Financial assets and institutions are strongly connected and influence each other. It is essential to study how the topological structures of financial networks could potentially influence market behaviors. Network analysis is an innovative method to enhance data mining and knowledge discovery in financial data. With the help of complex network theory, the topological network structures of a market can be extracted to reveal hidden information and relationships among stocks. In this study, two major markets of the most influential economies, China and the United States, are systematically studied from the perspective of financial network analysis. Results suggest that the network properties and hierarchical structures are fundamentally different for the two stock markets. The patterns embedded in the price movements are revealed and shed light on the market dynamics. Financial policymakers and regulators can gain inspiration from these findings for applications in policy making, regulations design, portfolio management, risk management, and trading

Enhancement of polar phases in PVDF by forming PVDF/SiC nanowire composite

Different contents of silicon carbide (SiC) nanowires were mixed with Poly(vinylidene fluoride) (PVDF) to facilitate the polar phase crystallization. It was shown that the annealing temperature and SiC content affected on the phase and crystalline structures of PVDF/SiC samples. Furthermore, the addition of SiC nanowire enhanced the transformation of non-polar α phase to polar phases and increased the relative fraction of β phase in PVDF. Due to the nucleating agent mechanism of SiC nanowires, the ion-dipole interaction between the negatively charged surface of SiC nanowires and the positive CH2 groups in PVDF facilitated the formation of polar phases in PVDF

A Metalloprotease Homolog Venom Protein From a Parasitoid Wasp Suppresses the Toll Pathway in Host Hemocytes

Parasitoid wasps depend on a variety of maternal virulence factors to ensure successful parasitism. Encapsulation response carried out by host hemocytes is one of the major host immune responses toward limiting endoparasitoid wasp offspring production. We found that VRF1, a metalloprotease homolog venom protein identified from the endoparasitoid wasp, Microplitis mediator, could modulate egg encapsulation in its host, the cotton bollworm, Helicoverpa armigera. Here, we show that the VRF1 proenzyme is cleaved after parasitism, and that the C-terminal fragment containing the catalytic domain enters host hemocytes 6 h post-parasitism. Furthermore, using yeast two-hybrid and pull-down assays, VRF1 is shown to interact with the H. armigera NF-κB factor, Dorsal. We also show that overexpressed of VRF1 in an H. armigera cell line cleaved Dorsal in vivo. Taken together, our results have revealed a novel mechanism by which a component of endoparasitoid wasp venom interferes with the Toll signaling pathway in the host hemocytes

Elevated Expression of miR-19b Enhances CD8+ T Cell Function by Targeting PTEN in HIV Infected Long Term Non-progressors With Sustained Viral Suppression

Human immunodeficiency virus (HIV)-infected long-term non-progressors (LTNPs) are of particular importance because of their unique disease progression characteristics. Defined by the maintenance of normal CD4+T cells after more than 8 years of infection, these LTNPs are heterogeneous. Some LTNPs exhibit ongoing viral production, while others do not and are able to control viral production. The underlying basis for this heterogeneity has not been clearly elucidated. In this study, the miRNA expression profiles of LTNPs were assessed. The levels of microRNA-19b (miR-19b) were found to be significantly increased in peripheral blood mononuclear cells of LTNPs with lower rather than higher viral load. We made clear that miR-19b may regulate CD8+T cell functions in HIV infection, which has not been addressed before. Overexpression of miR-19b promoted CD8+T cell proliferation, as well as interferon-γ and granzyme B expression, while inhibiting CD8+T cells apoptosis induced by anti-CD3/CD28 stimulation. The target of miR-19b was found to be the “phosphatase and tensin homolog”, which regulates CD8+T cells function during HIV infections. Furthermore, we found that miR-19b can directly inhibit viral production in in-vitro HIV infected T cells. These results highlight the importance of miR-19b to control viral levels, which facilitate an understanding of human immunodeficiency virus pathogenesis and provide potential targets for improved immune intervention

Retrospective analysis of 23 Chinese children with congenital hyperinsulinism undergoing pancreatectomy

Introduction: The aim of the study was to discuss therapeutic effect and prognosis of pancreatectomy in the treatment of congenital hyperinsulinism (CHI). Material and methods: A total of 23 Chinese children with CHI, who had undergone pancreatectomy, were selected as the study objects. The clinical data, the results of the 18Fluoro-L-3-4 dihydroxyphenylalanine positron emission tomography/computerized tomography (18F-DOPA PET/CT) scanning, and the diagnosis, treatment, and follow-up were analysed retrospectively. Results: Among the 23 cases, 14 patients were diagnosed with focal-type CHI via a 18F-DOPA PET/CT scan prior to the operation, with the lesions removed via partial pancreatectomy. After the operation, ten patients (71%) had normal blood glucose levels, while frequent feeding was required in four patients (29%) to control the hypoglycaemia. Three cases were diagnosed as diffuse-type CHI via preoperative scanning, two of which were treated by subtotal pancreatectomy. The other case was treated by near-total pancreatectomy, and the blood glucose level was normal following the operation. The remaining six cases were not diagnosed via the pancreatic scanning prior to the operation due to the limitation of certain conditions. Here, pancreatectomy was performed directly due to severe hypoglycaemia. Conclusions: 18F-DOPA PET/CT scanning was a reliable method for determining the histological type and localizing the lesion before the operation. Partial pancreatectomy for focal-type CHI had a high cure rate.