2,164 research outputs found

    Analysis of the structural integrity of a frozen wall during a mine shaft excavation using temperature monitoring data

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    This paper describes the results of the temperature monitoring of a frozen wall (FW) around the skip shaft of a potash mine under construction. The data on temperature measurements in control-thermal boreholes were used to parameterize the mathematical model of heat transfer, which allowed for the reconstruction of the temperature field throughout the entire cooled and frozen soil volume. The resulting temperature distribution in the FW zone for greater than 1 year was used to determine the distribution of the strength properties and calculate the temporary change in the limiting value of the external lateral load on an FW of a given thickness and specified thermomechanical properties. The obtained dependencies of the maximum external load on the FW can be used to optimize the operation mode of the freezing station at the ice holding stage (or passive freezing) to increase the energy efficiency of the system and ensure the structural integrity of the FW

    Direct photons at forward rapidities in high-energy pp collisions

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    We investigate direct photon production in pp collisions at the energies of RHIC, CDF and LHC, at different rapidities employing various color-dipole models. The cross section peaks at forward rapidities due to the abelian dynamics of photon radiation. This opens new opportunities for measurement of direct photons at forward rapidities, where the background from radiative hadronic decays is strongly suppressed. Our model calculations show that photon production is sensitive to the gluon saturation effects, and strongly depends on the value of the anomalous dimension.Comment: 7 pages, 8 figures, minor clarifications added. The version to appear in PL

    Glauber - Gribov approach for DIS on nuclei in N=4 SYM

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    In this paper the Glauber-Gribov approach for deep-inelastic scattering (DIS) with nuclei is developed in N=4 SYM. It is shown that the amplitude displays the same general properties, such as geometrical scaling, as is the case in the high density QCD approach. We found that the quantum effects leading to the graviton reggeization, give rise to an imaginary part of the nucleon amplitude, which makes the DIS in N=4 SYM almost identical to the one expected in high density QCD. We concluded that the impact parameter dependence of the nucleon amplitude is very essential for N=4 SYM, and the entire kinematic region can be divided into three regions which are discussed in the paper. We revisited the dipole description for DIS and proposed a new renormalized Lagrangian for the shock wave formalism which reproduces the Glauber-Gribov approach in a certain kinematic region. However the saturation momentum turns out to be independent of energy, as it has been discussed by Albacete, Kovchegov and Taliotis. We discuss the physical meaning of such a saturation momentum Qs(A)Q_s(A) and argue that one can consider only Q>Qs(A)Q>Q_s(A) within the shock wave approximation.Comment: 40pp.,9 figures in eps file

    COHORT PROFILE: The Complications of Long-Term Antiretroviral Therapy study in Uganda (CoLTART), a prospective clinical cohort.

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    BACKGROUND: Antiretroviral therapy (ART) improves the survival and quality of life of HIV-positive individuals, but the effects of long-term ART use do eventually manifest. The Complications of Long-Term Antiretroviral Therapy cohort study in Uganda (CoLTART) was established to investigate the metabolic and renal complications of long-term ART use among Ugandan adults. We describe the CoLTART study set-up, aims, objectives, study methods, and also report some preliminary cross-sectional study enrolment metabolic and renal complications data analysis results. METHODS: HIV-positive ART naïve and experienced adults (18 years and above) in Uganda were enrolled. Data on demographic, dietary, medical, social economic and behaviour was obtained; and biophysical measurements and a clinical examination were undertaken. We measured: fasting glucose and lipid profiles, renal and liver function tests, full blood counts, immunology, virology and HIV drug resistance testing. Plasma samples were stored for future studies. RESULTS: Between July 2013 and October 2014, we enrolled 1095 individuals, of whom 964 (88.0%) were ART experienced (6 months or more), with a median of 9.4 years (IQR 7.0-9.9) on ART. Overall, 968 (88.4%) were aged 35 years and above, 711 (64.9%) were females, 608 (59.6%) were or had ever been on a Tenofovir ART regimen and 236 (23.1%) on a Protease Inhibitor (PI) regimen. There were no differences in renal dysfunction between patients on Tenofovir and Non-Tenofovir containing ART regimens. Patients on PI regimens had higher total cholesterol, lower high density lipoprotein, higher low density lipoprotein, higher triglycerides, and a high atherogenic index for plasma than the non-PI regimen, p = 0.001 or < 0.001. Patients on Non-PI regimens had higher mean diastolic hypertension than patients on PI regimens, p < 0.001. CONCLUSIONS: Our finding of no differences in renal dysfunction between patients on Tenofovir and those on Non-Tenofovir containing ART regimens means that Tenofovir based first line ART can safely be initiated even in settings without routine renal function monitoring. However, integration of cardiovascular risk assessment, preventive and curative measures against cardiovascular disease are required. The CoLTART cohort is a good platform to investigate the complications of long-term ART use in Uganda

    Analysis of the structural integrity of a frozen wall during a mine shaft excavation using temperature monitoring data

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    The construction of shafts of potash mines in flooded and unstable soils is usually carried out with the help of artificial ground freezing. The freezing process aims to form a waterproof frozen wall (FW) around the shaft and is monitored throughout the construction of the mine shaft. This paper describes the results of the temperature monitoring of the FW around the skip shaft of a potash mine under construction. The data on temperature measurements in control-thermal boreholes were used to parameterize the mathematical model of heat transfer, which allowed for the reconstruction of the temperature field throughout the entire cooled and frozen soil volume. The resulting temperature distribution in the FW zone for greater than one year was used to determine the distribution of the strength properties and calculate the temporary change in the limiting value of the external lateral load on an FW of a given thickness and specified thermomechanical properties. The obtained dependencies of the maximum external load on the FW can be used to optimize the operation mode of the freezing station at the ice holding stage (or passive freezing) to increase the energy efficiency of the system and ensure the structural integrity of the FW

    Serum microRNA-122 and miR-155 as biomarkers of liver injury and inflammation in models of acute and chronic liver disease

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    Background: MicroRNAs (miRs) are small non-coding molecules that regulate gene expression. MiRs expression levels change not only in diseased tissues but also in circulation. Further, miRs are stable in frozen samples that make them attractive for biomarker discovery. Recent reports suggest altered expression of circulating miRNAs in various diseases. MiR-122 is highly abundant in hepatocytes where it regulates different metabolic pathways while miR-155 is a central regulator of inflammation. The aim of this study was to evaluate circulating miRNAs as potential markers of hepatocyte damage and inflammation in liver diseases. Methods: Serum/plasma and liver samples were collected from C57/BL6 mice after: 1. Chronic alcohol feeding with Lieber-deCarli diet containing alcohol or pair-fed diet for 5 weeks 2. Acetaminophen (APAP) administration. 3. TLR9/4 administration. 4. CCL4 administration. Serum/plasma ALT was evaluated and total RNA was analyzed for miRNAs expression with TaqMan MicroRNA assay. Non-parametric Mann-Whitney test was used for statistics. Results: The alcohol, APAP, TLR9/TLR4 and CCL4, -induced liver injury models all resulted in ALT increase and more important, in increased serum/plasma miR-122 levels compared to control mice. There was a linear correlation between miR-122 and ALT levels. After CCL4 treatment, serum miR-122 was upregulated as early as one week over controls and it remained elevated. No increase in serum miR-122 in Toll like receptor 4 or NADPH oxidase–deficient mice was found after alcohol feeding as these KO mice were protected from alcohol-induced liver injury and inflammation. Alcohol-, APAP, TLR9/TLR4 and CCL4-induced liver damage all involve in activation of the inflammatory cascade. Consistent with this, we found increased serum miR-155 levels. Conclusion: Our novel results show that serum/plasma miR-122 up-regulation correlates with ALT, thus, miR-122 could be a useful biomarker in acute and chronic liver injury. We also report that serum miR-155 is increased in liver disease with inflammation

    Argon-photoion–Auger-electron Coincidence Measurements Following K-shell Excitation by Synchrotron Radiation

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    Argon photoion spectra have been obtained for the first time in coincidence with K-LL and K-LM Auger electrons, as a function of photon energy. The simplified charge distributions which result exhibit a much more pronounced photon-energy dependence than do the more complicated noncoincident spectra. In the near-K-threshold region, Rydberg shakeoff of np levels, populated by resonant excitation of K electrons, occurs with significant probability, as do double-Auger processes and recapture of the K photoelectron through postcollision interaction
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