Browsing by Author "Zhang, Y."
Now showing 1 - 9 of 9
Results Per Page
Sort Options
Item Goji Berries as a Potential Natural Antioxidant Medicine: An Insight into Their Molecular Mechanisms of Action(Oxidative medicine and cellular longevity, 2019-01) Ma, Z.F.; Zhang, H.; Teh, S.S.; Wang, C.W.; Zhang, Y.; Hayford, F.; Wang, L.; Ma, T.; Dong, Z.; Zhang, Y.; Zhu, Y.Goji berries (Lycium fruits) are usually found in Asia, particularly in northwest regions of China. Traditionally, dried goji berries are cooked before they are consumed. They are commonly used in Chinese soups and as herbal tea. Moreover, goji berries are used for the production of tincture, wine, and juice. Goji berries are high antioxidant potential fruits which alleviate oxidative stress to confer many health protective benefits such as preventing free radicals from damaging DNA, lipids, and proteins. Therefore, the aim of the review was to focus on the bioactive compounds and pharmacological properties of goji berries including their molecular mechanisms of action. The health benefits of goji berries include enhancing hemopoiesis, antiradiation, antiaging, anticancer, improvement of immunity, and antioxidation. There is a better protection through synergistic and additive effects in fruits and herbal products from a complex mixture of phytochemicals when compared to one single phytochemical.Item Inkjet-printed graphene electrodes for dye-sensitized solar cells(Carbon, 2016) Dodoo-Arhin, D.; Howe, R.C.T.; Hu, G.; Zhang, Y.; Hiralal, P.; Bello, A.; Amaratunga, G.; Hasan, T.We present a stable inkjet printable graphene ink, formulated in isopropyl alcohol via liquid phase exfoliation of chemically pristine graphite with a polymer stabilizer. The rheology and low deposition temperature of the ink allow uniform printing. We use the graphene ink to fabricate counter electrodes (CE) for natural and ruthenium-based dye-sensitized solar cells (DSSCs). The repeatability of the printing process for the CEs is demonstrated through an array of inkjet-printed graphene electrodes, with ~5% standard deviation in the sheet resistance. As photosensitizers, we investigate natural tropical dye extracts from Pennisetum glaucum, Hibiscus sabdariffa and Caesalpinia pulcherrima. Among the three natural dyes, we find extracts from C. pulcherrima exhibit the best performance, with ~0.9% conversion efficiency using a printed graphene CE and a comparable ~1.1% efficiency using a platinum (Pt) CE. When used with N719 dye, the inkjet-printed graphene CE shows a ~3.0% conversion efficiency, compared to ~4.4% obtained using Pt CEs. Our results show that inkjet printable graphene inks, without any chemical functionalization, offers a flexible and scalable fabrication route, with a material cost of only ~2.7% of the equivalent solution processed Pt-based electrodes.Item Lexicons of women's empowerment online: Appropriating the other.(2010) Gajjala, R.; Zhang, Y.; Dako-Gyeke, P.In this essay, we examine discourses of women's emancipation online. We examine some nuances of how these lexicons of empowerment play out. One discursive formation examined is websites around female genital mutilation (FGM) in online activism while a second is the Americans for United Nations Population Fund (UNFPA) website. The third case is based in work offline trying to develop strategies for online marketing. This case discusses the (im)possibility of sustaining handloom and craft communities through online marketing of such products, arguing that online marketing of such products often tends to be subsumed by the logic of charity towards oppressed women. We try to show how lexicons of women's empowerment online are situated in an ideological framing that ends up being counterproductive over the long run. In each of the cases described, the possibilities for articulation are constrained by the same discourse that claims to empower.Item Lipid-related genetic polymorphisms significantly modulate the association between lipids and disability progression in multiple sclerosis(Journal of Neurology, Neurosurgery and Psychiatry, 2019-01) Zhang, Y.; Zhou, Y.; Van Der Mei, I.A.F.; Simpson, S.; Ponsonby, A.L.; Lucas, R.M.; Tettey, P.; Charlesworth, J.; Kostner, K.; Taylor, B.V.Objective To investigate whether lipid-related or body mass index (BMI)–related common genetic polymorphisms modulate the associations between serum lipid levels, BMI and disability progression in multiple sclerosis (MS). Methods The association between disability progression (annualised Expanded Disability Status Scale (EDSS) change over 5 years, ΔEDSS) and lipid-related or BMI-related genetic polymorphisms was evaluated in a longitudinal cohort (n=184), diagnosed with MS. We constructed a cumulative genetic risk score (CGRS) of associated polymorphisms (p<0.05) and examined the interactions between the CGRS and lipid levels (measured at baseline) in predicting ΔEDSS. All analyses were conducted using linear regression. Results Five lipid polymorphisms (rs2013208, rs9488822, rs17173637, rs10401969 and rs2277862) and one BMI polymorphism (rs2033529) were nominally associated with ΔEDSS. The constructed lipid CGRS showed a significant, dose-dependent association with ΔEDSS (ptrend=1.4×10−6), such that participants having ≥6 risk alleles progressed 0.38 EDSS points per year faster compared with those having ≤3. This CGRS model explained 16% of the variance in ΔEDSS. We also found significant interactions between the CGRS and lipid levels in modulating ΔEDSS, including high-density lipoprotein (HDL; pinteraction=0.005) and total cholesterol:high-density lipoprotein ratio (TC:HDL; pinteraction=0.030). The combined model (combination of CGRS and the lipid parameter) explained 26% of the disability variance for HDL and 27% for TC:HDL. Interpretation In this prospective cohort study, both lipid levels and lipid-related polymorphisms individually and jointly were associated with significantly increased disability progression in MS. These results indicate that these polymorphisms and tagged genes might be potential points of intervention to moderate disability progression.Item Mapping helminth co-infection and co-intensity: geostatistical prediction in Ghana(PLoS Negl Trop Dis., 2011) Soares Magalhães, R.J.; Biritwum, N.K.; Gyapong, J.O.; Brooker, S.; Zhang, Y.; Blair, L.; Fenwick, A.; Clements, A.C.Background: Morbidity due to Schistosoma haematobium and hookworm infections is marked in those with intense coinfections by these parasites. The development of a spatial predictive decision-support tool is crucial for targeting the delivery of integrated mass drug administration (MDA) to those most in need. We investigated the co-distribution of S.haematobium and hookworm infection, plus the spatial overlap of infection intensity of both parasites, in Ghana. The aim was to produce maps to assist the planning and evaluation of national parasitic disease control programs. Methodology/Principal Findings: A national cross-sectional school-based parasitological survey was conducted in Ghana in 2008, using standardized sampling and parasitological methods. Bayesian geostatistical models were built, including a multinomial regression model for S. haematobium and hookworm mono- and co-infections and zero-inflated Poisson regression models for S. haematobium and hookworm infection intensity as measured by egg counts in urine and stool respectively. The resulting infection intensity maps were overlaid to determine the extent of geographical overlap of S.haematobium and hookworm infection intensity. In Ghana, prevalence of S. haematobium mono-infection was 14.4%, hookworm mono-infection was 3.2%, and S. haematobium and hookworm co-infection was 0.7%. Distance to water bodies was negatively associated with S. haematobium and hookworm co-infections, hookworm mono-infections and S. haematobium infection intensity. Land surface temperature was positively associated with hookworm mono-infections and S. haematobium infection intensity. While high-risk (prevalence .10–20%) of co-infection was predicted in an area around Lake Volta, co-intensity was predicted to be highest in foci within that area. Conclusions/Significance: Our approach, based on the combination of co-infection and co-intensity maps allows the identification of communities at increased risk of severe morbidity and environmental contamination and provides a platform to evaluate progress of control efforts.Item Phytochemical Properties and Nutrigenomic Implications of Yacon as a Potential Source of Prebiotic: Current Evidence and Future Directions(Foods, 2018-04) Cao, Y.; Ma, Z.F.; Zhang, H.; Jin, Y.; Zhang, Y.; Hayford, F.The human gut is densely populated with diverse microbial communities that are essential to health. Prebiotics and fiber have been shown to possess the ability to modulate the gut microbiota. One of the plants being considered as a potential source of prebiotic is yacon. Yacon is an underutilized plant consumed as a traditional root-based fruit in South America. Yacon mainly contains fructooligosaccharides (FOS) and inulin. Therefore, it has bifidogenic benefits for gut health, because FOS are not easily broken down by digestive enzymes. Bioactive chemical compounds and extracts isolated from yacon have been studied for their various nutrigenomic properties, including as a prebiotic for intestinal health and their antimicrobial and antioxidant effects. This article reviewed scientific studies regarding the bioactive chemical compounds and nutrigenomic properties of extracts and isolated compounds from yacon. These findings may help in further research to investigate yacon-based nutritional products. Yacon can be considered a potential prebiotic source and a novel functional food. However, more detailed epidemiological, animal, and human clinical studies, particularly mechanism-based and phytopharmacological studies, are lacking for the development of evidence-based functional food products.Item Polygenic risk scores for CARDINAL study(nature, 2022) Adebamowo, C.A.; Adeyemo, A.; Ashaye, A.; Akpa, O.M.; Chikowore, T.; Choudhury, A.; Fakim, Y.J.; Fatumo, S.; Hanchard, N.; Hauser, M.; Mitchell, B.; Mulder, N.; Ofori-Acquah, S.F.; Owolabi, M.; Ramsay, M.; Tayo, B.; VasanthKumar, A.B.; Zhang, Y.; Adebamowo, S.N.Item Recent Advances in Astragalus membranaceus Anti-Diabetic Research: Pharmacological Effects of Its Phytochemical Constituents(Hindawi Publishing Corporation, Evidence-Based Complementary and Alternative Medicine, 2013-11-05) Agyemang, K.; Han, L.; Liu, E.; Zhang, Y.; Wang, T.; Gao, X.The disease burden of diabetes mellitus is increasing throughout the world. The need for more potent drugs to complement the present anti-diabetic drugs has become an imperative. Astragalus membranaceus, a key component of most Chinese herbal antidiabetic formulas, has been an important prospect for lead anti-diabetic compounds. It has been progressively studied for its antidiabetic properties. Ethnopharmacological studies have established its potential to alleviate diabetes mellitus. Recent studies have sought to relate its chemical constituents to types 1 and 2 diabetes mellitus. Its total polysaccharides, saponins, and flavonoids fractions and several isolated compounds have been the most studied. The total polysaccharides fraction demonstrated activity to both types 1 and 2 diabetes mellitus.This paper discusses the anti-diabetic effects and pharmacological action of the chemical constituents in relation to types 1 and 2 diabetes mellitus.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.