Particles migrating and plugging mechanism in loosen sandstone heavy oil reservoir and the strategy of production with moderate sanding

Fine rock particles is easy to be suspended and carried in loosen sandstone heavy oil reservoir due to the higher density and viscosity of heavy oil. The sand particles settle down, bridge and clog in pore and throat, as the result, the filtration resistance in reservoir will be redistributed. It significantly impacts on the well productivity. In this paper, the process of sand particles transporting and clogging in tunnels of rock is observed utilizing a microscopic visualization model with the unconsolidated sandpack. Furthermore, the mechanism of fine particles migration and clogging and the effects to percolation capacity of porous medium is investigated through the dynamic permeability changes in the weak-consolidated sandpack tube is monitored under different conditions of particles suspended fluid injection. It is shown that the performance of permeability decline with particles migration is affected by the size and sorting of mobile particles and throats, concentration of suspended particles, total amount of particles and the pressure drawdown or fluid flowing velocity, the maximum permeability reduction and the clogging transition time is determined by the minimum size of bridging particles. As a field application example, the strategy of production with moderate sanding in loosen sandstone heavy oil reservoir is discussed at the end of this pape

Transcriptome profile of halofuginone resistant and sensitive strains of Eimeria tenella

The antiparasitic drug halofuginone is important for controlling apicomplexan parasites. However, the occurrence of halofuginone resistance is a major obstacle for it to the treatment of apicomplexan parasites. Current studies have identified the molecular marker and drug resistance mechanisms of halofuginone in Plasmodium falciparum. In this study, we tried to use transcriptomic data to explore resistance mechanisms of halofuginone in apicomplexan parasites of the genus Eimeria (Apicomplexa: Eimeriidae). After halofuginone treatment of E. tenella parasites, transcriptome analysis was performed using samples derived from both resistant and sensitive strains. In the sensitive group, DEGs associated with enzymes were significantly downregulated, whereas the DNA damaging process was upregulated after halofuginone treatment, revealing the mechanism of halofuginone-induced parasite death. In addition, 1,325 differentially expressed genes (DEGs) were detected between halofuginone resistant and sensitive strains, and the DEGs related to translation were significantly downregulated after halofuginone induction. Overall, our results provide a gene expression profile for further studies on the mechanism of halofuginone resistance in E. tenella

Quantitative magnetization transfer of white matter tracts correlates with diffusion tensor imaging indices in predicting the conversion from mild cognitive impairment to Alzheimer's disease

Patients with amnestic mild cognitive impairment (aMCI) have higher probability to develop Alzheimer's disease (AD) than elderly controls. The detection of subtle changes in brain structure associated with disease progression and the development of tools to identify patients at high risk for dementia in a short time is crucial. Here, we used probabilistic white matter (WM) tractography to explore microstructural alterations within the main association, limbic, and commissural pathways in aMCI patients who converted to AD after 1 year follow-up (MCIconverters) and those who remained stable (MCIstable). Both diffusion tensor imaging (DTI) and quantitative magnetization transfer (qMT) parameters have been considered for a comprehensive pathophysiological characterization of the WM damage. Overall, tract-specific parameters derived from qMT and DTI at baseline were able to differentiate aMCI patients who converted to AD from those who remained stable in time. In particular, the qMT exchange rate, RMB0, of the right uncinate fasciculus was significantly decreased in MCIconverters, whereas fractional anisotropy was significantly decreased in the bilateral superior cingulum in MCIconverters compared to MCIstable. These results confirm the involvement of WM and particularly of association fibers in the progression of AD, highlighting disconnection as a potential mechanism

Oceanic Residual Depth Measurements, the Plate Cooling Model and Global Dynamic Topography

Convective circulation of the mantle causes deflections of the Earth's surface that vary as a function of space and time. Accurate measurements of this dynamic topography are complicated by the need to isolate and remove other sources of elevation, arising from flexure and lithospheric isostasy. The complex architecture of continental lithosphere means that measurement of present-day dynamic topography is more straightforward in the oceanic realm. Here, we present an updated methodology for calculating oceanic residual bathymetry, which is a proxy for dynamic topography. Corrections are applied that account for the effects of sedimentary loading and compaction, for anomalous crustal thickness variations, for subsidence of oceanic lithosphere as a function of age, and for non-hydrostatic geoid height variations. Errors are formally propagated to estimate measurement uncertainties. We apply this methodology to a global database of 1,936 seismic surveys located on oceanic crust and generate 2,297 spot measurements of residual topography, including 1,161 with crustal corrections. The resultant anomalies have amplitudes of ±1 km and wavelengths of ∼1,000 km. Spectral analysis of our database using cross-validation demonstrates that spherical harmonics up to and including degree 30 (i.e. wavelengths down to 1,300 km) are required to accurately represent these observations. Truncation of the expansion at a lower maximum degree erroneously increases the amplitude of inferred long-wavelength dynamic topography. There is a strong correlation between our observations and free-air gravity anomalies, magmatism, ridge seismicity, vertical motions of adjacent rifted margins, and global tomographic models. We infer that shorter wavelength components of the observed pattern of dynamic topography may be attributable to the presence of thermal anomalies within the shallow asthenospheric mantle.This research is supported by a BP-Cambridge collaboration

High-Content Lithium Aluminum Titanium Phosphate-Based Composite Solid Electrolyte with Poly(ionic liquid) Binder

Solid electrolytes have been regarded as the most promising electrolyte materials for the next generation of flexible electronic devices due to their excellent safety and machinability. Herein, composite solid electrolytes (CSE) with “polymer in ceramic” are prepared by using lithium aluminum titanium phosphate (LATP) as a matrix and modified poly(ionic liquid) as a binder. The results revealed that adding a poly(ionic liquid)-based binder not only endowed good flexibility for solid electrolytes, but also significantly improved the ionic conductivity of the electrolytes. When the content of LATP in the CSE was 50 wt.%, the electrolyte obtained the highest ionic conductivity (1.2 × 10−3 S·cm−1), which was one order of magnitude higher than that of the pristine LATP. Finally, this study also characterized the compression resistance of the composite solid-state electrolyte by testing the Vickers hardness, and the results showed that the hardness of the composite solid-state electrolyte can reach 0.9 ± 0.1 gf/mm2 at a LATP content of 50 wt.%

MiR-3976 regulates HCT-8 cell apoptosis and parasite burden by targeting BCL2A1 in response to Cryptosporidium parvum infection

Abstract Background Cryptosporidium is second only to rotavirus as a cause of moderate-to-severe diarrhea in young children. There are currently no fully effective drug treatments or vaccines for cryptosporidiosis. MicroRNAs (miRNAs) are involved in regulating the innate immune response to Cryptosporidium parvum infection. In this study, we investigated the role and mechanism of miR-3976 in regulating HCT-8 cell apoptosis induced by C. parvum infection. Methods Expression levels of miR-3976 and C. parvum burden were estimated using real-time quantitative polymerase chain reaction (RT-qPCR) and cell apoptosis was detected by flow cytometry. The interaction between miR-3976 and B-cell lymphoma 2-related protein A1 (BCL2A1) was studied by luciferase reporter assay, RT-qPCR, and western blotting. Results Expression levels of miR-3976 were decreased at 8 and 12 h post-infection (hpi) but increased at 24 and 48 hpi. Upregulation of miR-3976 promoted cell apoptosis and inhibited the parasite burden in HCT-8 cells after C. parvum infection. Luciferase reporter assay indicated that BCL2A1 was a target gene of miR-3976. Co-transfection with miR-3976 and a BCL2A1 overexpression vector revealed that miR-3976 targeted BCL2A1 and suppressed cell apoptosis and promoted the parasite burden in HCT-8 cells. Conclusions The present data indicated that miR-3976 regulated cell apoptosis and parasite burden in HCT-8 cells by targeting BCL2A1 following C. parvum infection. Future study should determine the role of miR-3976 in hosts’ anti-C. parvum immunity in vivo. Graphical Abstrac

Lignin as Renewable and Superior Asphalt Binder Modifier

The utilization of lignin for fungible products remains a major challenge for biofuel, pulp and paper industries. We hereby demonstrated the potential of lignin to be used as the asphalt binder modifier, and addressed the challenges in producing high-performance asphalt binder modifiers from lignin. We first demonstrated that Kraft lignin could improve the high temperature performance of asphalt binder, yet compromise the low temperature performance. To address the challenge, we developed both enzyme-mediator-based biological processing and formic acid-based chemical processing to derive lignin fractions to improve the high temperature performance of asphalt binder without compromising its low temperature performance. Moreover, the soluble fraction of biologically processed lignin could improve both high temperature and low temperature performance of asphalt binder, which enabled lignin to serve as a modifier with unique features. We also carried out a thorough characterization of different lignin fractions, and revealed the potential mechanisms for lignin to improve the asphalt binder performance. Overall, the study opened the new avenues for lignin to serve as an exceptional modifier and renewable substitute to improve both high and low temperature performance of asphalt binder. The novel application also transformed lignin waste into a valuable byproduct with market size compatible to biorefinery, pulp and paper industries