766 research outputs found

    The Minimal GUT with Inflaton and Dark Matter Unification

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    Giving up the solutions to the fine-tuning problems, we propose the non-supersymmetric flipped SU(5)×U(1)XSU(5)\times U(1)_X model based on the minimal particle content principle, which can be constructed from the four-dimensional SO(10)SO(10) models, five-dimensional orbifold SO(10)SO(10) models, and local F-theory SO(10)SO(10) models. To achieve gauge coupling unification, we introduce one pair of vector-like fermions, which form complete SU(5)×U(1)XSU(5)\times U(1)_X representation. Proton lifetime is around 5×10355\times 10^{35} years, neutrino masses and mixing can be explained via seesaw mechanism, baryon asymmetry can be generated via leptogenesis, and vacuum stability problem can be solved as well. In particular, we propose that inflaton and dark matter particle can be unified to a real scalar field with Z2Z_2 symmetry, which is not an axion and does not have the non-minimal coupling to gravity. Such kind of scenarios can be applied to the generic scalar dark matter models. Also, we find that the vector-like particle corrections to the Bs0B_s^0 masses can be about 6.6%, while their corrections to the K0K^0 and Bd0B_d^0 masses are negligible.Comment: 5 pages, 4 figures;V2: published versio

    Supergravity inflation on a brane

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    We discuss supergravity inflation in braneworld cosmology for the class of potentials V(ϕ)=αϕnexp(βmϕm)V(\phi)=\alpha \phi^n\rm{exp}(-\beta^m \phi^m) with m=1, 2m=1,~2. These minimal SUGRA models evade the η\eta problem due to a broken shift symmetry and can easily accommodate the observational constraints. Models with smaller nn are preferred while models with larger nn are out of the 2σ2\sigma region. Remarkably, the field excursions required for 6060 ee-foldings stay sub-planckian Δϕ<1\Delta\phi <1.Comment: 10 pages, 4 figure

    Metabolism and Metabolic Inhibition of Xanthotoxol in Human Liver Microsomes

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    Cytochrome p450 (CYP450) enzymes are predominantly involved in Phase I metabolism of xenobiotics. In this study, the CYP450 isoforms involved in xanthotoxol metabolism were identified using recombinant CYP450s. In addition, the inhibitory effects of xanthotoxol on eight CYP450 isoforms and its pharmacokinetic parameters were determined using human liver microsomes. CYP1A2, one of CYP450s, played a key role in the metabolism of xanthotoxol compared to other CYP450s. Xanthotoxol showed stronger inhibition on CYP3A4 and CYP1A2 compared to other isoenzymes with the IC50 of 7.43 μM for CYP3A4 and 27.82 μM for CYP1A2. The values of inhibition kinetic parameters (Ki) were 21.15 μM and 2.22 μM for CYP1A2 and CYP3A4, respectively. The metabolism of xanthotoxol obeyed the typical monophasic Michaelis-Menten kinetics and Vmax, Km, and CLint values were calculated as 0.55 nmol·min−1·mg−1, 8.46 μM, and 0.06 mL·min−1·mg−1. In addition, the results of molecular docking showed that xanthotoxol was bound to CYP1A2 with hydrophobic and π-π bond and CYP3A4 with hydrogen and hydrophobic bond. We predicted the hepatic clearance (CLh) and the CLh value was 15.91 mL·min−1·kg−1 body weight. These data were significant for the application of xanthotoxol and xanthotoxol-containing herbs

    Identification of the Metabolic Enzyme Involved Morusin Metabolism and Characterization of Its Metabolites by Ultraperformance Liquid Chromatogaphy Quadrupole Time-of-Flight Mass Spectrometry (UPLC/Q-TOF-MS/MS)

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    Morusin, the important active component of a traditional Chinese medicine, Morus alba L., has been shown to exhibit many vital pharmacological activities. In this study, six recombinant CYP450 supersomes and liver microsomes were used to perform metabolic studies. Chemical inhibition studies and screening assays with recombinant human cytochrome P450s were also used to characterize the CYP450 isoforms involved in morusin metabolism. The morusin metabolites identified varied greatly among different species. Eight metabolites of morusin were detected in the liver microsomes from pigs (PLMs), rats (RLMs), and monkeys (MLMs) by LC-MS/MS and six metabolites were detected in the liver microsomes from humans (HLMs), rabbits (RAMs), and dogs (DLMs). Four metabolites (M1, M2, M5, and M7) were found in all species and hydroxylation was the major metabolic transformation. CYP1A2, CYP2C9, CYP2D6, CYP2E1, CYP3A4, and CYP2C19 contributed differently to the metabolism of morusin. Compared to other CYP450 isoforms, CYP3A4 played the most significant role in the metabolism of morusin in human liver microsomes. These results are significant to better understand the metabolic behaviors of morusin among various species

    FOCAC at 21: future trajectories of China-Africa relations

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    The China-Africa relationship has continued to evolve over the last years. In light of the 8th Forum on China-Africa Cooperation (FOCAC) that will take place later in 2021, the latest report from LSE IDEAS China Foresight brings together an international team of experts to shed light on emerging and consolidated areas of engagement between China and Africa that will likely shape the relationship in the years to come

    Comparison of the Inhibitory Potential of Bavachalcone and Corylin against UDP-Glucuronosyltransferases

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    Bavachalcone and corylin are two major bioactive compounds isolated from Psoralea corylifolia L., which has been widely used as traditional Chinese medicine for many years. As two antibiotic or anticancer drugs, bavachalcone and corylin are used in combination with other drugs; thus it is necessary to evaluate potential pharmacokinetic herb-drug interactions (HDI) of the two bioactive compounds. The aim of the present study was to compare the effects of liver UDP-glucuronosyltransferase (UGT) 1A1, UGT1A3, UGT1A7, UGT1A8, UGT 1A10, and UGT2B4 inhibited by bavachalcone and corylin. 4-Methylumbelliferone (4-MU) was used as a nonspecific “probe” substrate. Bavachalcone had stronger inhibition on UGT1A1 and UGT1A7 than corylin which did not inhibit UGT1A1, UGT1A3, UGT1A7, UGT1A8, UGT1A10, and UGT2B4. Data fitting using Dixon and Lineweaver-Burk plots demonstrated the noncompetitive inhibition of bavachalcone against UGT1A1 and UGT1A7-mediated 4-MU glucuronidation reaction. The values of inhibition kinetic parameters (Ki) were 5.41 μM and 4.51 μM for UGT1A1 and UGT1A7, respectively. The results of present study suggested that there was a possibility of UGT1A1 and UGT1A7 inhibition-based herb-drug interaction associated with bavachalcone and provided the basis for further in vivo studies to investigate the HDI potential between bavachalcone and UGT substrates

    The impact of e-commerce on transportation dependency

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    Growth of world population has directly caused traffic congestion particularly in the cities.With the development of technologies such as the internet applications have changed the way of doing things.The e-commerce allows buying to be done at any place and at any time, in the word, subjected to the availability of internet connections.The e-commerce has impacted the buying behaviour and business operations. Ecommerce is boomed as it provides the virtual platform to trade the goods and services by just a click without brick and mortal store.It has the ability to re-direct consumer to shop from physical store to online marketplace around the globe. The individuals’ journeys to the stores are replaced by frequent deliveries by the courier companies. Growing of e-commerce is able to reduce the private vehicles on road as the delivery services provide by e-retailer.This paper provides more insights into the relationships between e-commerce and transportation dependency.This study examines the role of buying behavior in e-commerce in affecting the transportation dependency in Malaysia. Non probability convenient sampling method used to collect the data from the students studying at Universiti Utara Malaysia (UUM).The data were collected from 400 undergraduate students in UUM by using semi-structured questionnaire.In the pilot test, the Cronbach’s alpha score is 0.927, which is reliable.The findings are expected to widen the knowledge regard the impacts of e-commerce on transportation dependency

    Effects of saponins Rb1 and Re in American ginseng combined intervention on immune system of aging model

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    Aging is a major risk factor for the development of many pathological processes, such as reduced immunity, cancer, cardiovascular diseases or neurodegenerative diseases, while age-related chronic diseases are the most common causes of death. This paper studies the effects of American ginseng saponin Rb1 and Re alone and combined intervention on the immune system of aging mouse models, by using 30 mg/kg Rb1, 15 mg/kg Re, and Rb1 + Re (30 mg/kg Rb1 and 15 mg/kg Re (co-intervention) was used to intervene in the aging model, and immune indicators such as thymus index, spleen index, interleukin and interferon were detected to evaluate the impact of Rb1 and Re on immune function. The results show that Rb1 and Re intervention alone can increase the spleen index by 7%–12% and the thymus index by 12%–19% in the aging model. After Rb1 or Re alone intervened, the apoptotic cells in the thymus were slightly reduced, and the proportion of apoptotic cells was reduced. The combination of Rb1 + Re can promote the thymus index and spleen index to increase by 23.40% and 25.5% respectively, which is more advantageous than Rb1 or Re alone. In addition, Rb1 and Re intervention can reduce the level of interferon INF to a level comparable to that of young mice. Rb1 + Re can not only reduce the INF content, but also reduce the TNF content. The above results show that American ginseng saponin Rb1 and Re can delay the decline of the immune system in the aging model, and the combined intervention of the two is significantly better than individual intervention in the recovery of the immune system. This paper can provide theoretical basis and data support for the development of American ginseng nutritional supplements and its application in aging groups products to improve immunity
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