Browsing by Author "Wang, Y."
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Item Entrapment of inclusions in continuous casting billet: Industrial observation and modeling(AIST – Association for Iron and Steel Technology, 2010) Wang, Y.; Zuo, X.; Zhang, L.; Li, S.; Dong, A.; Damoah, L.N.W.Item Eudesmane-Type Sesquiterpenes from Curcuma phaeocaulis and Their Inhibitory Activities on Nitric Oxide Production in RAW 264.7 Cells(European Journal of Organic Chemistry, 2014-09) Liu, Y.; Ma, J.; Wang, Y.; Donkor, P.O.; Li, Q.; Gao, S.; Hou, Y.; Xu, Y.; Cui, J.; Ding, L.; Zhao, F.; Kang, N.; Chen, L.; Qiu, F.Eight eudesmane-type sesquiterpenes - phaeusmanes A-H (1-8) - isolated for the first time in this work, and four others (9-12) isolated for the first time from plants in this work, together with fourteen known eudesmane derivatives, were isolated from the rhizomes of Curcuma phaeocaulis. Their structures were elucidated by 1D and 2D NMR and CD spectroscopy and HRMS. Compound 8 is the first example of a nitrogen-containing eudesmane-type sesquiterpene isolated from the genus Curcuma. Furthermore, inhibitory effects of the isolated compounds on NO production in lipopolysaccharide-activated macrophages were evaluated. Compounds 1, 6, 10, 19, 22, and 24 showed strong inhibitory activities on NO production with IC50 values of 3.2, 4.8, 1.2, 0.8, 3.8, and 0.8 μM, respectively. Preliminary structure-activity relationships for these compounds are proposed. A possible biogenetic pathway for nitrogen-containing eudesmane-type sesquiterpene 8 is postulated. Eight new sesquiterpenes (phaeusmanes A-H), together with eighteen known analogues, were isolated from the rhizomes of Curcuma phaeocaulis. Their complete structures were elucidated by NMR, MS, and CD spectroscopy. The NO inhibitory effects of the isolates are presented. A possible biogenetic pathway for N-containing eudesmane-type sesquiterpene 8 is postulated. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Item Fermentation of Saccharomyces cerevisiae in a one liter flask coupled with an external circulation ultrasonic irradiation slot: Influence of ultrasonic mode and frequency on the bacterial growth and metabolism yield(Ultrasonics Sonochemistry, 2019-02) Zhang, Z.; Xiong, F.; Wang, Y.; Dai, C.; Xing, Z.; Dabbour, M.; Mintah, B.; He, R.; Ma, H.In this study, the influences of ultrasonic treatments with different working modes (fixed frequency and sweeping frequency) and various frequencies on the bacterial growth and metabolism yield of Saccharomyces cerevisiae (S. cerevisiae) were investigated by employing an in situ ultrasonic irradiation slot coupled with a flask fermentation equipment. The results revealed that the in situ ultrasonic treatment could promote the bacterial growth and metabolism yield, and the effect of fixed frequency ultrasound (FF) was higher than sweeping frequency ultrasound (SF). The content of metabolite in the fermentation broth increased with FF and decreased after SF treatments. On the other hand, when the frequency of FF was more than 33 kHz, the growth of S. cerevisiae became weaken, and the mortality rate of S. cerevisiae increased in fermentation broth. At FF of 23 kHz and 48 h fermentation-time, ethanol content increased by 19.33%, and the content of β-phenylethanol and other volatile metabolites such as esters also increased. In conclusion, FF could significantly improve the growth of S. cerevisiae, and the FF of 23 kHz showed the optimum impact on fermentation process of S. cerevisiae.Item Genetic Analyses of Tanzanian Local Chicken Ecotypes Challenged with Newcastle Disease Virus(genes, 2019-07-15) Amuzu-Aweh, E.N.; Walugembe, M.; Mushi, J.R.; Chiwanga, G.H.; Msoffe, P.L.; Wang, Y.; Saelao, P.; Kelly, T.; Gallardo, R.A.; Zhou, H.; Lamont, S.J.; Muhairwa, A.P.; Dekkers, J.C.M.Newcastle Disease (ND) is a continuing global threat to domestic poultry, especially in developing countries, where severe outbreaks of velogenic ND virus (NDV) often cause major economic losses to households. Local chickens are of great importance to rural family livelihoods through provision of high-quality protein. To investigate the genetic basis of host response to NDV, three popular Tanzanian chicken ecotypes (regional populations) were challenged with a lentogenic (vaccine) strain of NDV at 28 days of age. Various host response phenotypes, including anti-NDV antibody levels (pre-infection and 10 days post-infection, dpi), and viral load (2 and 6 dpi) were measured, in addition to growth rate. We estimated genetic parameters and conducted genome-wide association study analyses by genotyping 1399 chickens using the Affymetrix 600K chicken SNP chip. Estimates of heritability of the evaluated traits were moderate (0.18–0.35). Five quantitative trait loci (QTL) associated with growth and/or response to NDV were identified by single-SNP analyses, with some regions explaining ≥1% of genetic variance based on the Bayes-B method. Immune related genes, such as ETS1, TIRAP, and KIRREL3, were located in regions associated with viral load at 6 dpi. The moderate estimates of heritability and identified QTL indicate that NDV response traits may be improved through selective breeding of chickens to enhance increased NDV resistance and vaccine efficacy in Tanzanian local ecotypes.Item Regulated expression of the Ras effector Rin1 in forebrain neurons(Mol Cell Neurosci., 2010) Dzudzor, B.; Huynh, L.; Thai, M.; Bliss, J.M.; Nagaoka, Y.; Wang, Y.; Ch'ng, T.H.; Jiang, M.; Martin, K.C.; Colicelli, J.The Ras effector Rin1 is induced concomitant with synaptogenesis in forebrain neurons, where it inhibits fear conditioning and amygdala LTP. In epithelial cells, lower levels of Rin1 orchestrate receptor endocytosis. A 945 bp Rin1 promoter fragment was active in hippocampal neurons and directed accurate tissue-specific and temporal expression in transgenic mice. Regulated expression in neurons and epithelial cells was mediated in part by Snail transcriptional repressors: mutation of a conserved Snail site increased expression and endogenous Snai1 was detected at the Rin1 promoter. We also describe an element closely related to, but distinct from, the consensus site for REST, a master repressor of neuronal genes. Conversion to a consensus REST sequence reduced expression in both cell types. These results provide insight into regulated expression of a neuronal Ras effector, define a promoter useful in telencephalic neuron studies, and describe a novel REST site variant directing expression to mature neurons.Item A review on phytochemistry, pharmacology and toxicology studies of Aconitum(Journal of Pharmacy and Pharmacology, 2015-01) Nyirimigabo, E.; Xu, Y.; Li, Y.; Wang, Y.; Agyemang, K.; Zhang, Y.Objectives A number of species belonging to herbal genus Aconitum are well-known and popular for their medicinal benefits in Indian, Vietnamese, Korean, Japanese, Tibetan and Chinese systems of medicine. It is a valuable drug as well as an unpredictable toxic material. It is therefore imperative to understand and control the toxic potential of herbs from this genus. In this review, the ethnomedicinal, phytochemistry, pharmacology, structure activity relationship and toxicology studies of Aconitum were presented to add to knowledge for their safe application. Key findings A total of about 76 of all aconite species growing in China and surrounding far-east and Asian countries are used for various medical purposes. The main ingredients of aconite species are alkaloids, flavonoids, free fatty acids and polysaccharides. The tuberous roots of genus Aconitum are commonly applied for various diseases such as rheumatic fever, painful joints and some endocrinal disorders. It stimulates the tip of sensory nerve fibres. These tubers of Aconitum are used in the herbal medicines only after processing. There remain high toxicological risks of the improper medicinal applications of Aconitum. The cardio and neurotoxicities of this herb are potentially lethal. Many analytical methods have been reported for quantitatively and qualitatively characterization of Aconitum. Summary Aconitum is a plant of great importance both in traditional medicine in general and in TCM in particular. Much attention should be put on Aconitum because of its narrow therapeutic range. However, Aconitum's toxicity can be reduced using different techniques and then benefit from its pharmacological activities. New methods, approaches and techniques should be developed for chemical and toxicological analysis to improve its quality and safety. © 2014 Royal Pharmaceutical Society.