Rate Of Depletion Research Articles

State of art review of algal biodiesel and its blends influence on performance and emission characteristics of compression ignition engine

The current scenario, ever ending increase in depletion rate of petro-diesel and eventually their socio-economic impacts, strongly urges to invent appropriate substitute to petro-diesel. Profound research in the field has been carried out till time which is still continuing for investigating even more possible and probable way outs. In this context, the evaluation of the performance parameters of internal combustion engine is the essential step to ascertain the effective and appropriate fuel and its blends. This paper focus on extensive review of often discussed performance parameters such as break specific fuel consumption, break thermal efficiency and brake power. To widen the assortment of information in this field, the state of art review of the emission characteristics of Compression Ignition machine using algal biodiesel as a fuel has been recited through this survey. For evoking more precise knowledge of this review, the variety of fuel and engine type used for experimentation is thoroughly reviewed, analyzed and explained. It was found in review that there is an increase in brake power by 1%–20%, brake specific fuel consumption by 0.9%–13.90% and brake thermal efficiency from 1% to 27.65% which are in adoptable range. The emissions such as carbon monoxide and dioxides are found to be reduced considerably along with reduction in hydrocarbon emissions. The only exemption of oxides of nitrogen which found to be increase. Finally, it can be underlined that algae and its blends) characteristics were compatible with petroleum diesel and performance and emission parameters are in close proximity of diesel so, algal biodiesel and its blends can be used as diesel engine fuel without any modification in existing diesel engines. Considering the state of art review on this less explored topic, along with blends preparation, investigating physiochemical properties of blends and the impact of small proportion of algal biodiesel blends on performance and emission of compression ignition engine could be carried out.

How Do Inheritances Shape Wealth Inequality? Theory and Evidence from Sweden

Abstract This article aims to measure and understand the role of inheritances in shaping wealth inequality. We use a quasi-experimental design and Swedish administrative data to document that the average heir depletes her inheritance within a decade while the inheritances of wealthy heirs remain intact. These different depletion rates are not due to different consumption or labour supply responses but due to different rates of return on inherited wealth. Upon their receipt, inheritances reduce relative measures of wealth inequality, such as top shares or percentile ratios. Theoretically, this reduction in inequality could be due to either a compressed inheritance distribution or similar chances of having wealthy parents (high intergenerational mobility). Empirically, the first force is more significant in Sweden. Within a decade, however, the effect is reversed: inheritances increase wealth inequality since the different depletion rates widen the inequality in inherited wealth over time. This implies that inheritance taxation can reduce long run wealth inequality only through the taxation of wealthy heirs.

Interspecies Comparisons of the Effects of Potential Antiviral 3-Amidinophenylalanine Derivatives on Cytochrome P450 1A2 Isoenzyme

In vitro models of animals vulnerable to SARS-CoV-2 infection can support the characterization of effective antiviral drugs, such as synthetic inhibitors of the transmembrane protease serine 2 (TMPRSS2). Changes in cytochrome P450 (CYP) 1A2 activities in the presence of the potential TMPRSS2/matriptase inhibitors (MI) were measured using fluorometric and luminescent assays. Furthermore, the cytotoxicity of these inhibitors was evaluated using the MTS method. In addition, 60 min-long microsomal stability assays were performed using an UPLC-MS/MS procedure to elucidate depletion rates of the inhibitors. CYP1A2 was influenced significantly by MI-463 and MI-1900 in rat microsomes, by MI-432 and MI-482 in beagle microsomes, and by MI-432, MI-463, MI-482, and MI-1900 in cynomolgus monkey microsomes. The IC50 values in monkey microsomes were 1.30 ± 0.14 µM, 2.4 ± 1.4 µM, 0.21 ± 0.09 µM, and 1.1 ± 0.8 µM for inhibitors MI-432, MI-463, MI-482, and MI-1900, respectively. The depletion rates of the parent compounds were lower than 50%, independently of the investigated animal species. The host cell factor TMPRSS2 is of key importance for the cross-species spread of SARS-CoV-2. Studies of the in vitro biotransformation of TMPRSS2 inhibitors provide additional information for the development of new antiviral drugs.

A new warm-cloud collection and breakup parameterization scheme for weather and climate models

Microphysical process rates in bulk microphysics schemes have been parameterized in simple forms which may inadequately represent their complicated dependencies on hydrometeor quantities. In this study, we develop a bulk warm rain microphysics scheme that includes physically based parameterizations of collection and breakup. The parameterizations are derived from the stochastic collection and breakup equations by approximating the collection and breakup kernels in elaborate forms and analytically evaluating the integrals in those equations. Although the new scheme performs relatively complicated calculations, it is computationally not too expensive to be used in weather and climate models. We first evaluate the raindrop self-collection and collisional breakup (RSCB) parameterizations developed in this study using a box model. Under the intrinsic limitation of bulk schemes, they generally yield the equilibrium raindrop size distributions closest to those from a bin-based solver. We then evaluate the new scheme through the simulations of shallow cumuli field and a single warm convective cloud. In the simulation of shallow cumuli field, the new scheme quite well reproduces the observed cloud properties. Compared to two other bulk schemes, the new scheme yields somewhat different rainwater mass and raindrop number concentration, which is largely attributable to the differences in autoconversion parameterizations. In the simulation of a single warm convective cloud where RSCB plays a major role, the rate of raindrop number depletion by RSCB and the time of precipitation onset predicted by the new scheme are close to those predicted by a bin scheme used as the reference.

Growing Use and Impacts of Chemical Fertilizers and Assessing Alternative Organic Fertilizer Sources in Ethiopia

This paper reviews relevant facts and statistics about the benefits and impacts of the growing use of chemical fertilizer with a focus on soil fertility, crop productivity, and alternative sources of biofertilizers. Agriculture in Ethiopia is the main source of the economy, and it is the key contributor of the export value and provider of raw materials to processing industries. However, Ethiopian agronomical production is characterized by low output, lack of infrastructure, and low level of technology and is enormously dependent on rainfall availability. In Ethiopia, soil fertility reduction is evolving as a serious contest causing low crop yields, and research findings reported that, at the country level, nutrient balance indicated a depletion rate of 122 kg N ha−1 yr−1, 13 kg P ha−1 yr−1, and 82 kg K ha−1 yr−1. To control soil fertility depletion, primarily fertilizers are used as the source of essential plant nutrients. In Ethiopia, the use of chemical fertilizers to increase crop production was low relative to other developing countries; however, now, it is steadily increasing. Urea and diammonium phosphate are common practices for maintaining soil fertility. Chemical fertilizer consumption increased from 12 kg/ha in 1996 to 36.2 kg/ha in 2018. The main cereals’ production increased from 16.5 quintal/ha in 2009 to 23.94 quintal/ha in 2018.

Distinguishing between multiple mathematical models of neural stem cell quiescence and activation during age-related neural stem cell decline in neurogenesis

Stem cells are required for tissue maintenance and homeostasis during an organism’s lifetime. Neural stem cells (NSCs) can be in an actively dividing state or in a quiescent state. The balance between stem cell quiescence and cycling activity determines the rate of neurogenesis. With age, more NSCs enter the quiescent state, while the total number of NSCs decreases. Here we reconsider an existing mathematical model of how neural stem cells switch between active and quiescent states from the point of view of control theory by considering the activation rate, self-renewal probability, and division rate as control parameters rather than as pre-defined functions. Our goal is to test whether those modifications to the basic model could explain the observed decline of neural stem cells with age better than Gomerzian time-dependent parameters, and compare the output from different model variants to experimental data from mice using AIC. We find that time-dependent activation rate provides the best fit to the activated cell fraction (ACF) of NSCs over time, but that other model variants with constant parameter values can better fit the total number of NSCs over time. We also consider an alternate model for NSCs with nonlinear feedback from progenitor cells that affect NSC parameters, and compare all models to experimental stem cell and progenitor data. However, all of the feedback models considered provide a worse fit to the experimental data. This suggests that when switching between active and quiescent stem cells is considered, a time-dependent linear model outperforms the integral feedback mechanism considered by other models of stem cell lineages. Fitting progenitor data for both the time varying models and feedback models indicates that four or five intermediate transit amplifying progenitor states are necessary. Our modeling suggests that in order to determine whether an increase in age-related neural stem cell quiescence is determined by a decreasing stem cell activation rate or an increased stem cell depletion rate, additional experiments should be designed to explore whether or not depletion of the stem cell pool is occurring, and that a higher resolution time series for activated cell fraction (ACF) would be best to resolve this issue.

Effects of a Fully Humanized Type II Anti-CD20 Monoclonal Antibody on Peripheral and CNS B Cells in a Transgenic Mouse Model of Multiple Sclerosis.

Successful therapy with anti-CD20 monoclonal antibodies (mAbs) has reinforced the key role of B cells in the immunopathology of multiple sclerosis (MS). This study aimed to determine the effects of a novel class of anti-CD20 mAbs on vascular and extravascular central nervous system (CNS)-infiltrating B cells in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Male hCD20xhIgR3 mice and wild-type C57BL/6 (B6) mice were immunized with human myelin oligodendrocyte glycoprotein (MOG)1–125 to induce EAE. While hCD20xhIgR3 mice were injected intravenously with an anti-human CD20 mAb (5 mg/kg) (rituximab (a type I anti-CD20 mAb) or obinutuzumab (a type II anti-CD20 mAb), B6 mice received the anti-mouse CD20 antibody 18B12. Neither mAb affected clinical disease or serum antibody levels. Obinutuzumab and rituximab had an impact on splenic and CNS-infiltrated B cells with slightly differential depletion efficacy. Additionally, obinutuzumab had beneficial effects on spinal cord myelination. B cell depletion rates in the 18B12/B6 model were comparable with those observed in obinutuzumab-treated hCD20xhIgR3 mice. Our results demonstrate the usefulness of anti-CD20 mAbs for the modulation of B cell-driven peripheral immune response and CNS pathology, with type II antibodies potentially being superior to type I in the depletion of tissue-infiltrating B cells.

Fuel efficiency optimisation based on boosting control of the particulate filter active regeneration at high driving altitude

The air pressure change as a function of the driving altitude affects negatively the engine performance and emissions as well as the efficiency of the exhaust aftertreatment systems (ATS). These detrimental effects have driven the emissions standards to account for the altitude as boundary condition in type-approval tests. The new requirements demand to balance the recovery of the engine performance as the altitude increases by means of control strategies avoiding negative effects on tailpipe emissions, i.e. combination of engine-out emissions and ATS performance. In this context, this study identifies experimentally the need of optimisation of the active regeneration strategies applied to wall-flow particulate filters for altitude driving. Firstly, a particulate filter was subjected to active regenerations at altitudes ranging from sea-level to 2500 m for a variety of initial soot loads. As boundaries, the engine worked according to the series calibration, which was found to be a function of the altitude for the boosting system actuation. The results evidenced a noticeable deterioration of the soot oxidation rate as the altitude increased. In fact, some operating conditions showed an early balance between filtration and oxidation that avoided the completeness of the regeneration process. The root causes of the soot depletion rate reduction, which involved thermal and transport phenomena, are reasoned from the combined analysis of experimental and modelling approaches. The conclusions provided a guide to successfully conduct the turbine actuation for an optimum exhaust thermal management during the regeneration event at altitude.

Thermal performance of a controllable pavement solar collector prototype with configuration flexibility

Solar energy harvesting as a renewable and sustainable energy source has been widely investigated in recent years across engineering fields. The use of Pavement Solar Collectors (PSC) can lead to clean energy production, an increase in road safety, prolong the service life of asphalt pavement, and can mitigate the Urban Heat Island (UHI) effect. This study describes a controllable large-scale research PSC prototype with high configuration flexibility, and full monitoring capability at the University of Antwerp, Belgium. Since small- or laboratory-scale setups do not reflect the behavior of actual projects, the present paper investigates the thermal response of a large-scale PSC in the Western European climate, including heating load, heat extraction capacity, and asphalt surface and profile temperature changes during heating and cooling experiments.The study shows that a low supply temperature compared to high (14 °C vs. 28 °C) can reduce the depletion rate of the stored thermal energy in borehole thermal energy storage up to 7 times. The sensitivity analysis indicates that an increase in flow rate from laminar to transient regime requires twice as much thermal power compared to the same flow rate changes within transient and turbulent regimes. The maximum average daily efficiency of the PSC could reach 34% with a flow rate of 4 l/min. The experimental results showed that increasing the pipe length from 50 m to 200 m reduces the cumulative power extraction capacity by up to 48%. Furthermore, the PSC system shows great potential in reducing the asphalt surface temperature (up to 12 °C) to mitigate the UHI effects. Finally, the PSC system effectively controls the temperatures of the interface zones to reduce the rutting distress in the summertime and lower the potential of cold thermal crack developments and brittle shear failure behavior in wintertime.

In Vitro Comparative Study of Platelets Treated with Two Pathogen-Inactivation Methods to Extend Shelf Life to 7 Days.

Background and Objectives: Since 2015, platelet products have been pathogen-inactivated (PI) at the Luxemburgish Red Cross (LRC) using Riboflavin and UV light (RF-PI). As the LRC should respond to hospital needs at any time, platelet production exceeds the demand, generating a discard rate of 18%. To reduce this, we consider the extension of storage time from 5 to 7 days. This study’s objective was to evaluate the in vitro 7-day platelet-storage quality, comparing two PI technologies, RF-PI and amotosalen/UVA light (AM-PI), for platelet pools from whole-blood donations (PPCs) and apheresis platelets collected from single apheresis donation (APCs). Materials and Methods: For each product type, 6 double-platelet concentrates were prepared and divided into 2 units; one was treated with RF-PI and the other by AM-PI. In vitro platelet-quality parameters were tested pre- and post-PI, at days 5 and 7. Results: Treatment and storage lesions were observed in PPCs and APCs with both PI methods. We found a higher rate of lactate increase and glucose depletion, suggesting a stronger stimulation of the glycolytic pathway, a higher Annexin V binding, and a loss of swirling in the RF-PI-treated units from day 5. The platelet loss was significantly higher in the AM-PI compared with the RF-PI units. Conclusions: Results suggest that RF-PI treatment has a higher deleterious impact on in vitro platelet quality compared to AM-PI, but we observed higher loss of platelets with AM-PI due to the post-illumination amotosalen adsorption step. If 7-day storage is needed, it can only be achieved with AM-PI, based on our quality criteria.

Modelling of Boil-Off and Sloshing Relevant to Future Liquid Hydrogen Carriers

This study presents an approach for estimating fuel boil-off behaviour in cryogenic energy carrier ships, such as future liquid hydrogen (LH2) carriers. By relying on thermodynamic modelling and empirical formulas for ship motion and propulsion, the approach can be used to investigate boil-off as a function of tank properties, weather conditions, and operating velocities during a laden voyage. The model is first calibrated against data from a liquefied natural gas (LNG) carrier and is consequently used to investigate various design configurations of an LH2 ship. Results indicate that an LH2 ship with the same tank volume and glass wool insulation thickness as a conventional LNG carrier stores 40% of the fuel energy and is characterised by a boil-off rate nine times higher and twice as sensitive to sloshing. Adding a reliquefaction unit can reduce the LH2 fuel depletion rate by at least 38.7% but can increase its variability regarding velocity and weather conditions. In calm weather, LH2 boil-off rates can only meet LNG carrier standards by utilising at least 6.6 times the insulation thickness. By adopting fuel cell propulsion in an LH2 ship, a 1.1% increase in fuel delivery is expected. An LH2 ship with fuel cells and reliquefaction is required to be at least 1.7 times larger than an existing LNG carrier to deliver the same energy. Further comparison of alternative scenarios indicates that LH2 carriers necessitate significant redesigns if LNG carrier standards are desired. The present approach can assist future feasibility studies featuring other vessels and propulsion technologies, and can be seen as an extendable framework that can predict boil-off in real-time.

Structure and Dynamic Properties of a Glycerol-Betaine Deep Eutectic Solvent: When Does a DES Become an Aqueous Solution?

Deep eutectic solvents (DESs) are an emerging class of green solvents with a wide spectrum of potential applications whose properties may be further tailored through the addition of water. Here, we study, through molecular dynamics, the influence of water on the properties of a betaine-glycerol-water (B:G:W) DES (1:2:ζ; ζ = 0 to 100), aiming at getting insight into the structural and dynamic crossover between a DES and an aqueous solution. The density, shear viscosity, and diffusion coefficients are found to exhibit a non-linear dependence of ζ, similar to that observed for the solvation layers' composition. Each Gly and Bet are replaced, respectively, by ∼3 and ∼5 water molecules, with the highest rates of depletion being found for Gly around Bet and Gly around Gly. Above ζ = 7 (70 mol %; 29.5 wt %), a major structural transformation occurs, with the complete disruption of the second Bet-Gly solvation layer and the formation of a new second layer at a shorter distance, accompanied by a sudden change in the rate of increase of the components' diffusion. Nonetheless, opposite to other DES, our results indicate a smooth crossover between a DES and an aqueous solution.

Feasibility of innovative design concepts of Burnable poison pins for 24-month cycle PWR

In this study, two innovative burnable poison (BP) design concepts were introduced for an extended cycle of PWR. They are Double Tube Burnable Poison (DTBP) and Burnable poison Attached to Guide tube (BAG). DTBP is specifically designed for the 17 × 17 Westinghouse (WH) fuel assembly, and BAG is for the 16 × 16 Combustion Engineering (CE) fuel assembly. The DTBP design has two tubes inserted into each other, made of different absorber materials, and contained as a single tube by covering them with the cladding material. The inner tube is made of Al2O3-B4C with natural boron, and the outer tube is made of a low concentration of Gd2O3 homogeneously dispersed in ZIRLO. On the other hand, the BAG design contains four thin wires made of Al2O3-B4C with natural boron. These wires are attached to the outer wall of guide tubes. High-Assay Low Enriched Uranium (HALEU) fuel with enrichment of 6.96 w/o was used instead of the standard fuel to simulate a 24-month cycle length of PWR core. DeCART2D code was used to perform assembly calculations for both designs. Only DTBP design was further investigated by DeCART2D-MASTER code to perform core calculation and MCNP analysis to check the distribution of thermal neutrons flux and the depletion of poison materials at different layers of this design. After comparing these options with conventional BPs, the results showed that the DTBP and BAG + IFBA cases reduced the initial excess reactivity by about 44% and 43%, respectively. Also, they maintained the k-infinite letdown curve as the flattest line among all cases and obtained the lowest residual reactivity penalty with the values of 2806 pcm and 1898 pcm, respectively. Although the DTBP design has a slow depletion rate, the depletion of all the poison isotopes was complete before the end of the cycle, as proved by MCNP analysis. The DTBP + Erbia core achieved the 24-month cycle length without violating the design constraints of power peaking factor and moderator temperature coefficient (MTC).

Constraining organic matter composition and dynamics as a dominant driver of hypoxic blackwater risk during river Murray floodplain inundation

AbstractThe ecology of floodplain ecosystems evolved according to the historical frequency and extent of inundation. In many dryland rivers, inundation frequency has reduced due to regulation, competition for water resources and climate change. In some rivers infrastructure has been constructed to enable temporary rises in water level and more frequent floodplain inundation, delivering environmental water to ecosystems that are dependent on surface water. During such events, the release of dissolved organic carbon (DOC) from inundated plant material may result in depletion of dissolved oxygen (DO). If the rate of DO depletion exceeds re‐aeration, hypoxic conditions can occur. Models have been developed to represent these processes, however, there is a wide range of chemical and biological interactions, and hence model parameters, involved. The aim of this research was: (1) identify the dominant parameters through sensitivity analysis, (2) design and implement a field monitoring program to quantify the inherent variability in those parameters, and (3) translate that input variability into the modelled DO, ultimately to support risk management decisions when planning delivery of environmental water. The results indicated that the mass of organic matter on a floodplain had the greatest impact on the modelled DO concentrations. Based on the field monitoring results, the steady state load of organic matter, that is, when the accumulation and decay rates are equal, was estimated, and vegetation mapping used to apply the field monitoring results across the floodplain for a 206 km reach of river of the River Murray, Australia. The model results from multiple, cumulative, operations identified one particular high‐risk operational site. The results are useful to prioritize monitoring effort to focus on the most sensitive model parameters and indicate that the likelihood of hypoxic conditions can be reduced through slower rates of inundation and timing events to coincide with periods with lower water temperature. The methodology developed can be transferred to other sites where hypoxic conditions are a potential outcome associated with delivery of environmental water.

Management of invasive cells in soft biological tissues through modulated nonlinear excitations: Long-range effects

In the present paper, we investigate the contribution of long-range diffusion and diffusive stresses on cellular waves generated during an invasion in soft biological tissues. To that end, we consider a set of three coupled nonlinear partial differential equations describing spatiotemporal evolutions of cell density, extracellular matrix (ECM), and spatial displacements of a material point taken in the ECM. In addition to long-range diffusion, diffusive stresses, and proliferation, the model also accounts for ECM production-degradation. The linear stability analysis reveals that in presence of temporal perturbations, there is no stability-instability transition in the system. In presence of spatiotemporal perturbations, instability dominates but the stability-instability transition is controlled by proliferation rate and long-range diffusion of cells. Analytical solutions are constructed as well as their existence conditions provided. Amongst the structures recovered, breathers are associated with the transport of a high number of cells. Long-range diffusive stresses, saturation, and ECM depletion rate significantly modify the wave structure as well as the number of cells carried. On the other hand, Proliferation, ECM production rate, long-range haptotaxis, diffusion, and traction affect both spatial rearrangement and the number of cells carried by the wave. Through our analysis, numerical solutions remain positive, do not diverge from their analytical counterpart, meaning that the solutions proposed are stable and may be used to probe the inherent biological realities of the model considered.

Integrated microdevice with a windmill-like hole array for the clog-free, efficient, and self-mixing enrichment of circulating tumor cells

Circulating tumor cells (CTCs) have tremendous potential to indicate disease progression and monitor therapeutic response using minimally invasive approaches. Considering the limitations of affinity strategies based on their cost, effectiveness, and simplicity, size-based enrichment methods that involve low-cost, label-free, and relatively simple protocols have been further promoted. Nevertheless, the key challenges of these methods are clogging issues and cell aggregation, which reduce the recovery rates and purity. Inspired by the natural phenomenon that the airflow around a windmill is disturbed, in this study, a windmill-like hole array on the SU-8 membrane was designed to perturb the fluid such that cells in a fluid would be able to self-mix and that the pressure acting on cells or the membrane would be dispersed to allow a greater velocity. In addition, based on the advantages of fluid coatings, a lipid coating was used to modify the membrane surface to prevent cell aggregation and clogging of the holes. Under the optimal conditions, recovery rates of 93% and 90% were found for A549 and HeLa cells in a clinical simulation test of our platform with a CTC concentration of 20–100 cells per milliliter of blood. The white blood cell (WBC) depletion rate was 98.7% (n = 15), and the CTC detection limit was less than 10 cells per milliliter of blood (n = 6). Moreover, compared with conventional membrane filtration, the advantages of the proposed device for the rapid (2 mL/min) and efficient enrichment of CTCs without clogging were shown both experimentally and theoretically. Due to its advantages in the efficient, rapid, uniform, and clog-free enrichment of CTCs, our platform offers great potential for metastatic detection and therapy analyses.

Long term influence of groundwater preservation policy on stubble burning and air pollution over North-West India

Stubble burning (SB) has been a major source of seasonal aerosol loading and pollution over northern India. The aftereffects of groundwater preservation act i.e., post 2010 era (2011–2020) has seen delay in crop harvesting thereby shifting the peak SB to May (Wheat SB) and to November (Paddy SB) by 8–10 and 10–12 days compared to pre-2010. Groundwater storage depletion rate of 29.2 mm yr−1 was observed over the region. Post 2010 era shows an increase of 1.4% in wheat SB and 21% in Paddy SB fires over Punjab and Haryana with 70% of PM2.5 air mass clusters (high probability > 0.8) advecting to the downwind regions leading to 23–26% increase in PM2.5 and 4–6% in aerosol loading over National Capital Region (NCR). Although the objective of water conservation policy was supposed to preserve the groundwater by delaying the paddy transplantation and sowing, on the contrary the implementation of this policy has seen groundwater storage after 2013 depleting at a rate of 29.2 mmyr−1 over these regions. Post policy implementation has led to shift and shrinking of harvest window with increased occurrences in SB fires which also increase associated particulate matter pollution over North India.

Experimental investigation on the influence factors of primary production performance of tight oil

The effects of permeability, initial fluid pressure, effective stress, gas-oil ratio, pressure depletion rate, and oil viscosity on the primary production oil recovery were investigated in detail. The results show that the permeability of tight core is the most significant influence factor. When the permeability decreases from 3.0 × 10−3 µm2 to 0.0021 × 10−3 µm2, the oil and gas recoveries decrease from 45% and 90% to 10% and 20%. Furthermore, the initial fluid pressure also has great influence and the oil recovery linearly increases with the fluid pressure as well as the decrease of effective stress. When the initial fluid pressure increases from 6 MPa to 15 MPa, the oil and gas recoveries can be enhanced about 10% and 22%. Gas-oil ratio is another important parameter. When the gas-oil ratio is 26 m3⋅m−3, the oil recovery can reach approximately 30% compared to 2.7% at the gas-oil ratio of 0. The pressure depletion rate has a more obvious influence on the ultimate oil recovery for the cores with a low permeability, while with a low depletion rate after bubble point can enhance the oil recovery. The work can provide useful information for the choosing of key parameter and development method in tight oil production.

Biochemical profiling of functionally expressed CYP6P9 variants of the malaria vector Anopheles funestus with special reference to cytochrome b5 and its role in pyrethroid and coumarin substrate metabolism

Cytochrome P450 monooxygenases (P450s) are well studied enzymes catalyzing the oxidative metabolism of xenobiotics in insects including mosquitoes. Their duplication and upregulation in agricultural and public health pests such as anopheline mosquitoes often leads to an enhanced metabolism of insecticides which confers resistance. In the laboratory strain Anopheles funestus FUMOZ-R the duplicated P450s CYP6P9a and CYP6P9b are highly upregulated and proven to confer pyrethroid resistance. Microsomal P450 activity is regulated by NADPH cytochrome P450 oxidoreductase (CPR) required for electron transfer, whereas the modulatory role of cytochrome b5 (CYB5) on insect P450 activity is less clear. In previous studies CYP6P9a and CYP6P9b were recombinantly expressed in tandem with An. gambiae CPR using E. coli-expression systems and CYB5 added to the reaction mix to enhance activity. However, the precise role of CYB5 on substrate turn-over when combined with CYP6P9a and CYP6P9b remains poorly investigated, thus one objective of our study was to address this knowledge gap. In contrast to the CYP6P9 variants, the expression levels of both CYB5 and CPR were not upregulated in the pyrethroid resistant FUMOZ-R strain when compared to the susceptible FANG strain, suggesting no immediate regulatory role of these genes in pyrethroid resistance in FUMOZ-R. Here, for the first time we recombinantly expressed CYP6P9a and CYP6P9b from An. funestus in a baculovirus expression system using High-5 insect cells. Co-expression of each enzyme with CPR from either An. gambiae or An. funestus did not reveal noteworthy differences in catalytic capacity. Whereas the co-expression of An. funestus CYB5 – tested at different multiplicity of infection (MOI) ratios – resulted in a significantly higher metabolization of coumarin substrates as measured by fluorescence assays. This was confirmed by Michaelis-Menten kinetics using the most active substrate, 7-benzyloxymethoxy-4-trifluoromethylcoumarin (BOMFC). We observed a similar increase in coumarin substrate turnover by adding human CYB5 to the reaction mix. Finally, we compared by UPLC-MS/MS analysis the depletion rate of deltamethrin and the formation of 4’OH-deltamethrin by recombinantly expressed CYP6P9a and CYP6P9b with and without CYB5 and detected no difference in the extent of deltamethrin metabolism. Our results suggest that co-expression (or addition) of CYB5 with CYP6P9 variants, recombinantly expressed in insect cells, can significantly enhance their metabolic capacity to oxidize coumarins, but not deltamethrin.

The Slowing Rate of CpG Depletion in SARS-CoV-2 Genomes Is Consistent with Adaptations to the Human Host.

Depletion of CpG dinucleotides in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genomes has been linked to virus evolution, host-switching, virus replication, and innate immune responses. Temporal variations, if any, in the rate of CpG depletion during virus evolution in the host remain poorly understood. Here, we analyzed the CpG content of over 1.4 million full-length SARS-CoV-2 genomes representing over 170 million documented infections during the first 17 months of the pandemic. Our findings suggest that the extent of CpG depletion in SARS-CoV-2 genomes is modest. Interestingly, the rate of CpG depletion is highest during early evolution in humans and it gradually tapers off, almost reaching an equilibrium; this is consistent with adaptations to the human host. Furthermore, within the coding regions, CpG depletion occurs predominantly at codon positions 2-3 and 3-1. Loss of ZAP (Zinc-finger antiviral protein)-binding motifs in SARS-CoV-2 genomes is primarily driven by the loss of the terminal CpG within the motifs. Nonetheless, majority of the CpG depletion in SARS-CoV-2 genomes occurs outside ZAP-binding motifs. SARS-CoV-2 genomes selectively lose CpGs-motifs from a U-rich context; this may help avoid immune recognition by TLR7. SARS-CoV-2 alpha-, beta-, and delta-variants of concern have reduced CpG content compared to sequences from the beginning of the pandemic. In sum, we provide evidence that the rate of CpG depletion in virus genomes is not uniform and it greatly varies over time and during adaptations to the host. This work highlights how temporal variations in selection pressures during virus adaption may impact the rate and the extent of CpG depletion in virus genomes.