48 research outputs found
Evodiamine inhibits adipogenesis via the EGFR–PKCα–ERK signaling pathway
AbstractThe molecular mechanism of the anti-adipogenic effect of evodiamine (which has several capsaicin-like pharmacological actions) was investigated. The evodiamine effect was not blocked by the specific TRPV1 antagonist capsazepine in 3T3-L1 preadipocytes, whereas its effect was greatly curtailed by inhibitors of protein kinase C (PKC) and epidermal growth factor receptor (EGFR). Signal analyses showed that evodiamine stimulated the phosphorylation of EGFR, PKCα, and ERK, all of which were reduced by an EGFR inhibitor. Silencing experiments of EGFR mRNA supported the involvement of these signaling molecules in the inhibitory effect of evodiamine. An unidentified mechanism whereby evodiamine inhibits adipogenesis via the EGFR–PKCα–ERK signaling pathway was revealed
Mineral inclusions in pyrope crystals from Garnet Ridge, Arizona, USA: implications for processes in the upper mantle
Mineral inclusions in pyrope crystals from Garnet Ridge in the Navajo Volcanic Field on the Colorado Plateau are investigated in this study with emphasis on the oxide minerals. Each pyrope crystal is roughly uniform in composition except for diffusion halos surrounding some inclusions. The pyrope crystals have near constant Ca:Fe:Mg ratios, 0.3 to 5.7 wt% Cr 2 O 3, and 20 to 220 ppm H 2 O. Thermobarometric calculations show that pyrope crystals with different Cr contents formed at different depths ranging from 50 km (where T  ≈ 600 °C and P  = 15 kbar) to 95 km (where T  ≈ 800 °C and P  = 30 kbar) along the local geotherm. In addition to previously reported inclusions of rutile, spinel and ilmenite, we discovered crichtonite series minerals (AM 21 O 38 , where A  = Sr, Ca, Ba and LREE, and M mainly includes Ti, Cr, Fe and Zr), srilankite (ZrTi 2 O 6 ), and a new oxide mineral, carmichaelite (MO 2−x (OH) x , where M  = Ti, Cr, Fe, Al and Mg). Relatively large rutile inclusions contain a significant Nb (up to 2.7 wt% Nb 2 O 5 ), Cr (up to ∼6 wt% Cr 2 O 3 ), and OH (up to ∼0.9 wt% H 2 O). The Cr and OH contents of rutile inclusions are positively related to those of pyrope hosts, respectively. Needle- and blade-like oxide inclusions are commonly preferentially oriented. Composite inclusions consisting mainly of carbonate, amphibole, phlogopite, chlorapatite, spinel and rutile are interpreted to have crystallized from trapped fluid/melt. These minerals in composite inclusions commonly occur at the boundaries between garnet host and large silicate inclusions of peridotitic origin, such as olivine, enstatite and diopside. The Ti-rich oxide minerals may constitute a potential repository for high field strength elements (HFSE), large ion lithophile elements and light rare earth elements (LREE) in the upper mantle. The composite and exotic oxide inclusions strongly suggest an episode of metasomatism in the depleted upper mantle beneath the Colorado Plateau, contemporaneous with the formation of pyrope crystals. Our observations show that mantle metasomatism may deplete HFSE in metasomatic fluids/melts. Such fluids/melts may subsequently contribute substantial trace elements to island arc basalts, providing a possible mechanism for HFSE depletion in these rocks.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42226/1/410-135-2-3-164_91350164.pd
Calibration for IR measurements of OH in apatite
abstract In this work, we have calibrated the infrared (IR) method for determining OH concentrations in apatite with absolute concentrations obtained through elastic recoil detection (ERD) analysis. IR spectra were collected on oriented, single-crystal apatite samples using polarized transmission infrared spectroscopy. The weight percent H 2 O is 0.001199 ± 0.000029 (the error is given at 1σ level hereafter) times A/d, where A is the linear absorbance peak height measured using polarized IR when the light vector E is parallel to the c-axis of the apatite crystal, and d is the sample thickness in centimeters. This corresponds to a linear molar absorptivity, ε = 470 ± 11 L/mol/cm -1 . The calibration using linear absorbance can be applied when there is only one dominant peak at 3540 cm -1 . If other peaks are significant, then the integrated molar absorptivity, ε = (2.31 ± 0.06) ×10 4 L/mol/cm 2 , should be used. The detection limit of H 2 O concentration in apatite by IR approaches parts per million level for wafers of 0.1 mm thickness. The accuracy based on our calibration is 5-10% relative
Coupling Modes and Stoichiometry of Cl−/HCO3− Exchange by slc26a3 and slc26a6
The SLC26 transporters are a family of mostly luminal Cl− and HCO3− transporters. The transport mechanism and the Cl−/HCO3− stoichiometry are not known for any member of the family. To address these questions, we simultaneously measured the HCO3− and Cl− fluxes and the current or membrane potential of slc26a3 and slc26a6 expressed in Xenopus laevis oocytes and the current of the transporters expressed in human embryonic kidney 293 cells. slc26a3 mediates a coupled 2Cl−/1HCO3− exchanger. The membrane potential modulated the apparent affinity for extracellular Cl− of Cl−/HCO3− exchange by slc26a3. Interestingly, the replacement of Cl− with NO3− or SCN− uncoupled the transport, with large NO3− and SCN− currents and low HCO3− transport. An apparent uncoupled current was also developed during the incubation of slc26a3-expressing oocytes in HCO3−-buffered Cl−-free media. These findings were used to develop a turnover cycle for Cl− and HCO3− transport by slc26a3. Cl− and HCO3− flux measurements revealed that slc26a6 mediates a 1Cl−/2HCO3− exchange. Accordingly, holding the membrane potential at 40 and −100 mV accelerated and inhibited, respectively, Cl−-mediated HCO3− influx, and holding the membrane potential at −100 mV increased HCO3−-mediated Cl− influx. These findings indicate that slc26a6 functions as a coupled 1Cl−/2HCO3− exchanger. The significance of isoform-specific Cl− and HCO3− transport stoichiometry by slc26a3 and slc26a6 is discussed in the context of diseases of epithelial Cl− absorption and HCO3− secretion
Association Analysis of IL-17A and IL-17F Polymorphisms in Chinese Han Women with Breast Cancer
Background: Research into the etiology of breast cancer has recently focused on the role of the immunity and inflammation. The proinflammatory cytokines IL-17A and IL-17F can mediate inflammation and cancer. To evaluate the influences of IL-17A and IL-17F gene polymorphisms on the risk of sporadic breast cancer, a case-control study was conducted in Chinese Han women. Methodology and Principal Findings: We genotyped three single-nucleotide polymorphisms (SNPs) in IL-17A (rs2275913, rs3819025 and rs3748067) and five SNPs in IL-17F (rs7771511, rs9382084, rs12203582, rs1266828 and rs763780) to determine the haplotypes in 491 women with breast cancer and 502 healthy individuals. The genotypes were determined using the SNaPshot technique. The differences in the genotypic distribution between breast cancer patients and healthy controls were analyzed with the Chi-square test for trends. For rs2275913 in IL-17A, the frequency of the AA genotype was higher in patients than controls (P = 0.0016). The clinical features analysis demonstrated significant associations between IL-17 SNPs and tumor protein 53 (P53), progesterone receptor (PR), human epidermal growth factor receptor 2 (Her-2) and triple-negative (ER-/PR-/Her-2-) status. In addition, the haplotype analysis indicated that the frequency of the haplotype A rs2275913G rs3819025G rs3748067, located in the IL-17A linkage disequilibrium (LD) block, was higher in patients than in controls (P = 0.0471 after correction for multiple testing)
A heterogeneous lunar interior for hydrogen isotopes as revealed by the lunar highlands samples
Silicate melt properties and volcanic eruptions
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95246/1/rog1657.pd
Spatial Distribution Characteristics of Agritourism Consumption
Agritourism is a newly developed type of tourism, which is significant in promoting the sustainable development of rural economies and ecological environments. The spatial distribution of agritourism consumption is an important basis on which to formulate an agritourism development plan. This paper introduces the concept of agritourism consumption, which is applied to develop a theoretical model of spatial distribution based on the analogy that the attraction to agritourism by urban residents is similar to the attraction among charges in physics. With this model, the spatial distribution characteristics of agritourism consumption are investigated under the superposition of multifield sources arising from metropolitan regions. The results indicate that the field strength of agritourism consumption is gradually attenuated with spatial distance. The trend that field strength under multifield sources varies with distance is generally similar to that under a single field source, but the decay rate under multifield sources tends to slow down slightly in different directions. Due to the superposition of multifield sources, the spatial distribution of field strength is no longer in a pattern of concentric circles, but an uneven distribution of contour lines. In addition, there is a positive correlation between field strength distribution and the consumption demand of agritourism
An Interactive System Based on the IASP91 Earth Model for Earthquake Data Processing
System software for interactive human–computer data processing based on the IASP91 Earth model was designed. An interactive data processing system for visualizing earthquake data was designed and implemented via the Intel Fortran platform. The system reads and processes broadband seismic data acquired by field stations, mainly including the reading and import of raw data, pre-processing, identification of seismic phases and inter-correlation traveltimes picking. In the data processing step, shortcomings have been improved and functions have been gradually refined and enhanced, making it easier and faster to process data. It has already processed more than 1000 large seismic events received by the station from 2013 to 2018. The practical application shows that the human–computer interaction system is easy to operate, accurate, fast and flexible, and is an effective tool for processing seismic data
Accurate Redetermination of the Focal Depth by Using the Time Intervals between the Inner Core Phases PKIKP and pPKIKP
The hypocenter parameters of an earthquake may give us an insight into the Earth’s structure and tectonic processes. Among the hypocenter parameters, the focal depth is normally more difficult to estimate than the earthquake location (latitude and longitude). We propose to use the pPKIKP-PKIKP arrival time intervals for estimating the focal depth. We analyze the sensitivity of the pPKIKP-PKIKP arrival time interval to the earthquake depth. We measure the pPKIKP-PKIKP arrival time interval on seismograms (the vertical component), and invert the time interval data set using the simulated annealing inversion algorithm. We illustrate the inversion approach on two teleseismic earthquakes which have shallow and deep focal depths, and demonstrate that the approach is indeed appropriate to the shallow and deep event. We can obtain a reliable estimate on focal depth, even though the seismic station is sparse or in a remote part of the epicenter