712 research outputs found
A study of the impact of the Ceramic Materials Research program at the University of Washington Final report, 15 Jun. 1968 - 15 Sep. 1969
Impact of Ceramic Materials Research Program at University of Washingto
A Joint Venture of Ab Initio Molecular Dynamics, Coupled Cluster Electronic Structure Methods, and Liquid-State Theory to Compute Accurate Isotropic Hyperfine Constants of Nitroxide Probes in Water
The isotropic hyperfine coupling constant (HFCC, Aiso) of a pH-sensitive spin probe in a solution, HMI (2,2,3,4,5,5-hexamethylimidazolidin-1-oxyl, C9H19N2O) in water, is computed using an ensemble of state-of-the-art computational techniques and is gauged against X-band continuous wave electron paramagnetic resonance (EPR) measurement spectra at room temperature. Fundamentally, the investigation aims to delineate the cutting edge of current first-principles-based calculations of EPR parameters in aqueous solutions based on using rigorous statistical mechanics combined with correlated electronic structure techniques. In particular, the impact of solvation is described by exploiting fully atomistic, RISM integral equation, and implicit solvation approaches as offered by ab initio molecular dynamics (AIMD) of the periodic bulk solution (using the spin-polarized revPBE0-D3 hybrid functional), embedded cluster reference interaction site model integral equation theory (EC-RISM), and polarizable continuum embedding (using CPCM) of microsolvated complexes, respectively. HFCCs are obtained from efficient coupled cluster calculations (using open-shell DLPNO-CCSD theory) as well as from hybrid density functional theory (using revPBE0-D3). Re-solvation of âvertically desolvatedâ spin probe configuration snapshots by EC-RISM embedding is shown to provide significantly improved results compared to CPCM since only the former captures the inherent structural heterogeneity of the solvent close to the spin probe. The average values of the Aiso parameter obtained based on configurational statistics using explicit water within AIMD and from EC-RISM solvation are found to be satisfactorily close. Using either such explicit or RISM solvation in conjunction with DLPNO-CCSD calculations of the HFCCs provides an average Aiso parameter for HMI in aqueous solution at 300 K and 1 bar that is in good agreement with the experimentally determined one. The developed computational strategy is general in the sense that it can be readily applied to other spin probes of similar molecular complexity, to aqueous solutions beyond ambient conditions, as well as to other solvents in the longer run
Shot-noise spectroscopy of energy-resolved ballistic currents
We investigate the shot noise of nonequilibrium carriers injected into a
ballistic conductor and interacting via long-range Coulomb forces. Coulomb
interactions are shown to act as an energy analyzer of the profile of injected
electrons by means of the fluctuations of the potential barrier at the emitter
contact. We show that the details in the energy profile can be extracted from
shot-noise measurements in the Coulomb interaction regime, but cannot be
obtained from time-averaged quantities or shot-noise measurements in the
absence of interactions.Comment: 7 pages, 4 figure
Farnesoid X Receptor Deficiency Improves Glucose Homeostasis in Mouse Models of Obesity
International audienceOBJECTIVE Bile acids (BA) participate in the maintenance of metabolic homeostasis acting through different signaling pathways. The nuclear BA receptor farnesoid X receptor (FXR) regulates pathways in BA, lipid, glucose, and energy metabolism, which become dysregulated in obesity. However, the role of FXR in obesity and associated complications, such as dyslipidemia and insulin resistance, has not been directly assessed. RESEARCH DESIGN AND METHODS Here, we evaluate the consequences of FXR deficiency on body weight development, lipid metabolism, and insulin resistance in murine models of genetic and diet-induced obesity. RESULTS FXR deficiency attenuated body weight gain and reduced adipose tissue mass in both models. Surprisingly, glucose homeostasis improved as a result of an enhanced glucose clearance and adipose tissue insulin sensitivity. In contrast, hepatic insulin sensitivity did not change, and liver steatosis aggravated as a result of the repression of ÎČ-oxidation genes. In agreement, liver-specific FXR deficiency did not protect from diet-induced obesity and insulin resistance, indicating a role for nonhepatic FXR in the control of glucose homeostasis in obesity. Decreasing elevated plasma BA concentrations in obese FXR-deficient mice by administration of the BA sequestrant colesevelam improved glucose homeostasis in a FXR-dependent manner, indicating that the observed improvements by FXR deficiency are not a result of indirect effects of altered BA metabolism. CONCLUSIONS Overall, FXR deficiency in obesity beneficially affects body weight development and glucose homeostasis
Structural and temporal patterns of the first global trading market
Little is known about the structural patterns and dynamics of the first global trading market (FGTM), which emerged during the sixteenth century as a result of the Iberian expansion, let alone how it compares to today's global financial markets. Here we build a representative network of the FGTM using information contained in 8725 (handwritten) Bills of Exchange from that time-which were (human) interpreted and digitalized into an online database. We show that the resulting temporal network exhibits a hierarchical, highly clustered and disassortative structure, with a power-law dependence on the connectivity that remains remarkably robust throughout the entire period investigated. Temporal analysis shows that, despite major turnovers in the number and nature of the links-suggesting fast adaptation in response to the geopolitical and financial turmoil experienced at the time-the overall characteristics of the FGTM remain robust and virtually unchanged. The methodology developed here demonstrates the possibility of building and analysing complex trading and finance networks originating from pre-statistical eras, enabling us to highlight the striking similarities between the structural patterns of financial networks separated by centuries in time.This research was supported by FCT-Portugal through grant nos FCT-TECH/0002/2007 (A.S.R. and A.P.), SFRH/BD/77389/2011 (F.L.P.), SFRH/BPD/76278/2011 (A.S.R.), PTDC/MAT-STA/3358/2014 (F.L.P., F.C.S. and J.M.P.), PTDC/EEI-SII/5081/2014 (F.L.P., F.C.S. and J.M.P.), UID/BIA/04050/2013 (J.M.P.) and UID/CEC/50021/2013 (F.C.S.), and by the European Science Foundation through grant no. DynCoopNet-06-TECT-FP-004 (A.S.R. and A.P.)
Lifetime measurements of high-spin states in Ag-101 and their interpretation in the interacting boson fermion plus broken pair model
Lifetimes of 20 high spin states in Ag-101 in the range between 0.2 and 200 ps have been measuredand interpreted within the boson fermion plus broken pair model
Expression and methylation status of tissue factor pathway inhibitor-2 gene in non-small-cell lung cancer
Tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine proteinase inhibitor that inhibits plasmin-dependent activation of several metalloproteinases. Downregulation of TFPI-2 could thus enhance the invasive potential of neoplastic cells in several cancers, including lung cancer. In this study, TFPI-2 mRNA was measured using a real-time PCR method in tumours of 59 patients with non-small-cell lung cancer (NSCLC). Tumour TFPI-2 mRNA levels appeared well correlated with protein expression evaluated by immunohistochemistry and were 4â120 times lower compared to those of nonaffected lung tissue in 22 cases (37%). Hypermethylation of the TFPI-2 gene promoter was demonstrated by restriction enzyme-polymerase chain reaction in 12 of 40 cases of NSCLC (30%), including nine of 17 for whom tumour TFPI-2 gene expression was lower than in noncancerous tissue. In contrast, this epigenetic modification was shown in only three of 23 tumours in which no decrease in TFPI-2 synthesis was found (P=0.016). Decreased TFPI-2 gene expression and hypermethylation were more frequently associated with stages III or IV NSCLC (eight out of 10, P=0.02) and the TFPI-2 gene promoter was more frequently hypermethylated in patients with lymph node metastases (eight out of 16, P=0.02). These results suggest that silencing of the TFPI-2 gene by hypermethylation might contribute to tumour progression in NSCLC
Probing the action of a novel anti-leukaemic drug therapy at the single cell level using modern vibrational spectroscopy techniques
Acute myeloid leukaemia (AML) is a life threatening cancer for which there is an urgent clinical need for novel therapeutic approaches. A redeployed drug combination of bezafibrate and medroxyprogesterone acetate (BaP) has shown anti-leukaemic activity in vitro and in vivo. Elucidation of the BaP mechanism of action is required in order to understand how to maximise the clinical benefit. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, Synchrotron radiation FTIR (S-FTIR) and Raman microspectroscopy are powerful complementary techniques which were employed to probe the biochemical composition of two AML cell lines in the presence and absence of BaP. Analysis was performed on single living cells along with dehydrated and fixed cells to provide a large and detailed data set. A consideration of the main spectral differences in conjunction with multivariate statistical analysis reveals a significant change to the cellular lipid composition with drug treatment; furthermore, this response is not caused by cell apoptosis. No change to the DNA of either cell line was observed suggesting this combination therapy primarily targets lipid biosynthesis or effects bioactive lipids that activate specific signalling pathways
Vaccination against nonmutated neoantigens induced in recurrent and future tumors
Vaccination of patients against neoantigens expressed in concurrent tumors, recurrent tumors, or tumors developing in individuals at risk of cancer is posing major challenges in terms of which antigens to target and is limited to patients expressing neoantigens in their tumors. Here, we describe a vaccination strategy against antigens that were induced in tumor cells by downregulation of the peptide transporter associated with antigen processing (TAP). Vaccination against TAP downregulation-induced antigens was more effective than vaccination against mutation-derived neoantigens, was devoid of measurable toxicity, and inhibited the growth of concurrent and future tumors in models of recurrence and premalignant disease. Human CD8(+) T cells stimulated with TAP(low) dendritic cells elicited a polyclonal T-cell response that recognized tumor cells with experimentally reduced TAP expression. Vaccination against TAP downregulation-induced antigens overcomes the main limitations of vaccinating against mostly unique tumor-resident neoantigens and could represent a simpler vaccination strategy that will be applicable to most patients with cancer.Experimental cancer immunology and therap
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