Vital Effects Research Articles

Mechanical characteristics and reservoir stimulation mechanisms of the Gulong shale oil reservoirs, the northern Songliao Basin

Shale oil of the Qingshankou Formation of the Gulong Sag, the northern Songliao Basin, represents the first attempt at large-scale development of pure-shale-type shale oil in China. By integrating the multi-scale refined reservoir characterization with macro-micro-scale mechanical testing, it is clarified that the Gulong shale is characterized by high clay mineral content, high rock plasticity, highly-developed bedding, and prominent mechanical anisotropy. A three-dimensional (3D) fracture propagation model of hydraulic fracturing was built for the Gulong shale, which fully captures the hydraulic fracture distribution pattern affected by the high bedding density, in-situ stress, and fracturing treatment parameters. Our research showed that due to influences of bedding, hydraulic fracturing in the Gulong shale forms a complex fracture morphology featuring the main fracture with multiple perpendicular branches that have different lengths (like the outdoor directional TV antenna); however, the vertical propagation of fractures is inhibited, and the fracture height is commonly less than 10 m. The limited stimulated reservoir volume (SRV) is the main problem facing the fracturing stimulation of the Gulong shale oil. Bedding density has vital effects on fracture morphology, so case-specific fracturing designs shall be developed for shale intervals with different bedding development degrees. For reservoirs with well-developed bedding, it is suggested to properly increase the perforation cluster spacing and raise the volume and proportions of viscous fluids of the pad, so as to effectively promote vertical fracture propagation and improve reservoir stimulation performance. This study integrates multi-scale fine reservoir characterization and macro-micro-scale mechanical testing, as well as the construction and numerical simulation of hydraulic fracturing models for high-density layered shale reservoirs, providing a new approach and methodological framework for the fracturing research of high-density layered shale reservoirs.

Geochemical Differences Between Alive, Uncrusted and Dead, Crusted Shells of Neogloboquadrina pachyderma: Implications for Paleoreconstruction

AbstractPlanktic foraminiferal‐based trace element‐calcium ratios (TE/Ca) are a cornerstone in paleoceanographic reconstructions. While TE‐environment calibrations are often established through culturing experiments, shell growth in culture is not always consistent with growth in a natural setting. For example, many species of planktic foraminifera thicken their shell at the end of their life cycle, producing a distinct “gametogenic” crust. Crust is common in fossil foraminifers, however, shells grown in culture do not often develop a thick crust. Here, we investigate potential vital effects associated with the crusting process by comparing the trace element (Mg/Ca, Na/Ca, Ba/Ca, Sr/Ca, Mn/Ca, Zn/Ca) and stable isotope (δ13C, δ18O) composition of alive, fully mature, uncrusted shells to recently deceased, crusted shells of Neogloboquadrina pachyderma collected from the same plankton tows off the Oregon (USA) coast. We find that uncrusted (N = 55) shells yield significantly higher Ba/Ca, Na/Ca, Mn/Ca, and Sr/Ca than crusted (N = 66) shells, and crust calcite records significantly lower TE/Ca values for all elements examined. Isotopic mixing models suggest that the crust calcite accounts for ∼40%–70% of crusted shell volume. Comparison of foraminiferal and seawater isotopes indicate that N. pachyderma lives in the upper 90 m of the water column, and that crust formation occurs slightly deeper than their average living depth habitat. Results highlight the necessity to establish calibrations from crusted shells, as application of calibrations from TE‐enriched uncrusted shells may yield attenuated or misleading paleoceanographic reconstructions.

Evaluation of the stress relaxation behavior of poly (L‐lactic acid) self‐expanding braided stents

AbstractStress relaxation of poly (L‐lactic acid) (PLLA) braided stents generated after crimping will significantly influence the radial properties of the stents, due to the viscoelasticity of PLLA. In particular, the environmental temperature and duration in the relaxation process are two vital effects on these radial performances. Thereby, a serious of crimping temperatures and holding durations were adopted in this study to investigate their influence on the radial properties of stents. The radial properties of the stent, including peak compression force, chronic outward force and energy loss, were characterized by radial mechanical tests. Results showed that the stress relaxation rates of PLLA braided stents increased with the increase of the crimp‐holding temperature and time. Specifically, the stress relaxation rates at 25, 37 and 42°C were 22.81%, 28.41% and 36.10% at hold time of 300 s. Moreover, the increase of stress relaxation can reduce chronic outward force of stents, which will furtherly cause complications such as insufficient supporting and the shift of stent and so on. Therefore, decreasing the crimp‐holding temperature and duration of stents is an effective method to reduce the stent stress relaxation. This work provides experimental references for the comprehensive evaluation of mechanical properties of PLLA braided stent in clinical application.

Trace elements in bivalve shells: How “vital effects” can bias environmental studies

We report on the concentrations of rare earths (REE), Y, Mg, Mn, Cu, Zn, Sr, Ba, Pb and U in a series of wild scallops (Placopecten magellanicus) collected alive on the same day in Saint Pierre et Miquelon (a French archipelago located south of Newfoundland) and ranging in age from 2 to about 20 years. We analyzed representative fragments from the entire last annual shell growth increment of each animal to assess changes in trace element incorporation with age.No correlation with the age of the animals was obtained for Sr and Mn concentrations, which are quite variable from one individual to another, even of similar age. On the other hand, for REE, Y, Cu, Zn, Ba and U, the concentrations measured in the last annual growth increment formed by animals aged 2 to 7 years are similar. From 8 years of age, the concentrations of these elements increased very strongly (for example for Yb, almost by an order of magnitude between 8 and 20 years of age), and possibly with some variation between individuals of the same age. Two elements show a different behavior: Mg concentrations in the shell margins increase continuously with the age of the animals; Pb concentrations are scattered but seem to decrease with the age of the animals.This turning point in the behavior of the elements from 8 years of age coincides with major metabolic changes, since at this age wild P. magellanicus from Newfoundland reduce their growth, in favor of gamete production. Our results demonstrate that metabolic activity of the animals largely controls the incorporation of many trace elements into the shells. These results demonstrate that the age of the animals must be taken into account when their shells are used to study pollution or (paleo) environmental condition.

The Involvement of Melatonin and Tasimelteon against Alzheimer's Disease.

Alzheimer's disease (AD) is an age-dependent neurodegenerative disease with progressive cognition and memory loss, insomnia, and other abnormal behavioral changes. Amongst various hypotheses for AD pathophysiology, occupational stress-induced Alzheimer's has recently been reported in many AD cases. Studies pertaining to the same suggest that stress leads to insomnia or sleep disruption, which further leads to neuroinflammation due to oxidative stress, both of which are major harbingers of AD. Additionally, overall sleep deficit is associated with progressive cognitive and memory decline, which adds more inconvenience to Alzheimer's disease. Based on this, any triumphant AD management needs a pharmacological intervention that can not only antagonize the amyloid betainduced neurotoxicity but also correct the sleep-wake cycle disruption. Chronobiotic therapeutics like melatonin offer vital neuroprotective effects by eliciting its action through more than one of the pathologies of AD. This is also bolstered by the finding that endogenous melatonin levels are lower in AD patients. This melatonin replacement therapy can be especially useful in AD treatment, but only in the early phases of the disease and in cases where the melatonin receptors are intact and functioning. To negate such limitations and extend the action and therapeutic efficacy of melatonin- mediated actions towards AD treatment, melatonin analogue like tasimelteon can pose a high therapeutic value in AD treatment superior to that provided by melatonin. This review encapsulates all details about how AD is believed to occur and how current situations influence it, along with how melatonin and tasimelteon act towards treating Alzheimer's.

Sr/Ca-temperature calibration for the coral Montastraea cavernosa

The Sr/Ca ratio in coral skeletons is an important proxy for the reconstruction of sea surface temperatures (SST) of the environment and helps our knowledge about SST variability in the tropics. In the western tropical South Atlantic where the species Montastraea cavernosa is one of the most important reef-builders, only a few species have been evaluated as coral-based archives for environmental changes. Here we evaluate the Sr/Ca ratio recorded in the thecal wall and other skeletal structures of the species M. cavernosa and its implications for paleothermometry investigations. Sampling along the thecal wall generated a record of Sr/Ca ratios with well-defined annual cycles, but also with noisy intervals. A linear regression of the most recent 8 years of well-defined Sr/Ca ratios and SST results in the calibration equation Sr/Ca (mmol/mol) = −0.040 (±0.005) * SST (°C) + 10.15 (±0.15). This is the first calibration equation for this species. The skeletal elements of M. cavernosa were characterized by heterogeneous Sr/Ca ratios, with higher values for the columellae and septum, which could potentially generate a cold bias in reconstructed SST of up to 7.5 °C. The variability of Sr/Ca ratios in these structures overwhelms the annual seasonality of Sr/Ca ratios in the thecal wall, and the difference in Sr/Ca ratios observed from distinct skeletal structures may be related to biological or vital effects influencing the uptake of Sr into different coral structures. Furthermore, improving sampling techniques for M. cavernosa should be considered in future studies for the successful recovery of robust geochemical signals, eventually expanding the number of species used as natural archives in the western tropical South Atlantic.

A new wormhole mechanistic model for radial acid flow geometry using novel 3D flow correlations

In carbonate reservoirs, matrix acidizing is used to improve well performance by creating conductive channels called wormholes. Predicting wormhole propagation rate in radial acid flow geometry up to the real wellbore scale is the main problem regarding designing field operations in previous studies which are still challenging. In this study, a new mechanistic approach is presented to predict the radial flow acidizing up to near wellbore scale by considering the vital effects of porous media size and geometrical parameters of wormhole patterns.Accordingly, wormhole tip velocity and wormhole wall fluid loss rate will be introduced as the scale transferring parameters between different porous media sizes which are correlated in terms of rock diameter and wellbore height, wormhole size and density. These novel correlations are extracted from the large databank of flux distribution between rock matrix and wormhole channel obtained in 60 different 3D FEM flow simulations for various patterns of wormhole propagating and different wellbore sizes. In addition, an HPHT radial acid flooding setup is designed and constructed to perform radial acid coreflood on ultra-low permeable rocks (k«1md) for model validation. During the experiments, the breakthrough pore volume, pressure behavior and CT scan of samples are closely monitored. The results showed that due to the tight window of pore size distribution, faster breakthroughs with 1.23 and 1.45 pore volumes occurred in these tight samples compared to those reported already which are confirmed by developed model prediction. Besides, the model results showed that increasing the rock height (open-hole interval) would increase wormhole tip velocity and decrease acid breakthrough time. In addition, the higher temperature shifted the acid response curve to the right, toward higher acid breakthrough volume and higher acid concentration shifted it toward lower breakthrough volumes. The model is validated using radial acid experiments and previous radial acid models for different rock sizes with good agreement (R2 = 0.9547, MSE = 0.02161 and RMSE = 0.14701). The new radial acidizing model is capable to quickly predict wormhole propagation rate up to wellbore scale without requiring excess up-scaling data due to considering wide ranges of porous rock sizes from (25.4–152.4 cm) diameter and (5–25.4 cm) pay zone height (sufficient size for considering repetitive wormhole patterns). This technique can be utilized for tuning parameters of various radial cases to predict the acid tests results leading to reduce the number of required experiments.

Unraveling antibiotic resistomes associated with bacterial and viral communities in intertidal mudflat aquaculture area

The extensive use of antibiotics in intertidal mudflat aquaculture area has substantially increased the dissemination risk of antibiotic resistance genes (ARGs). As hosts of ARGs, bacteria and virus exert vital effects on ARG dissemination. However, the insights for the interrelationships among ARGs, bacteria, and virus have not been thoroughly explored in intertidal mudflat. Therefore, this study attempts to unravel the occurrence, dissemination, evolution, and driving mechanisms of ARGs associated with bacterial and viral communities using metagenomic sequencing in a typical intertidal mudflat. Abundant and diverse ARGs (22 types and 437 subtypes) were identified and those of ARGs were higher in spring than in autumn. It is worthy noted that virus occupied a more essential position than bacteria for ARGs dissemination through network analysis. Meanwhile, nitrogen exerted indirect effect on ARG profiles by shaping viral and bacterial diversity. According to the results of neutral and null models, deterministic processes dominated the ARG community assembly by controlling sediment nitrogen and antibiotics. Homogeneous and variable selection dominated phylogenetic turnover of ARG community, contributing 46.15% and 45.90% of the total processes, respectively. This study can hence theoretically support for the ARG pollution control and management in intertidal mudflat aquaculture area.

Chemical fractionation in benthic fauna from Saya de Malha Bank (Mascarene Plateau, western Indian Ocean): Vital and habitat effects

The temperature, salinity, nutrient availability and dissolved oxygen characterizing ocean water-masses and circulation patterns are essential environmental controlling parameters of marine benthic assemblages. This work presents for the first time the geochemical composition of different taxonomic groups of benthic assemblages from the Saya de Malha Bank, Mascarene Plateau (Indian Ocean). The studied stations, located in water masses at different water depths, are perfect spots for studying biogeochemical proxies of diverse taxonomic groups to elucidate the impact of the vital factor as opposed to environmental or oceanographic factors. Forty-two specimens were studied, including scleractinian corals, bryozoans, brachiopods, bivalves, gastropods, scaphopods, and echinoids. Specimens were taphonomically analyzed in order to discard those with a poor preservation that might affect the geochemical assays. Geochemical analyses of the specimens involved high resolution inductively coupled plasma-mass spectrometry for main and trace elements. According to the results, (1) the content of trace elements in the shells is primarily controlled by their mineralogy: i.e. aragonitic, low-Mg calcite, and high-Mg calcite. (2) Vital effects related to metabolism play a major role in the co-precipitation and adsorption of trace elements in the shells, especially for Ca, Mg, Sr, Ba, and Zn. (3) The environmental parameters (habitat effect) such as oxygenation, primary productivity, salinity, but mainly temperature, at different water depths were found to be related to the growth rate of the specimens and the incorporation of trace elements. In the shallower station, the Li/Mg ratio is lower and the content in U is higher among the selected taxa, which is related to an increased growth rate in warmer waters.

The vital effects of Bacillus subtilis during carbon isotope fractionation in the process of carbonate precipitation

The carbon isotope composition (δ13C) of biogenic carbonates has been a valuable tool for reconstructing paleoenvironments worldwide. However, the vital effects of microbes during carbon isotope fractionation (CIF) in the process of microbial induced carbonate precipitation (MICP) have not been fully revealed. In this study, calcium carbonate (CaCO3) biomineralization experiments have been performed using the Bacillus subtilis strain 168 under the standing condition. In addition, corresponding shaking experiments and inorganic experiments were also carried out, respectively. We have quantified the temporal change of δ13C values of the carbonate minerals and dissolved inorganic carbon (DIC) as well as the cellular density, Ca2+ and HCO3− concentrations, and the carbonic anhydrase (CA) activity. X-ray diffraction analysis has shown that the precipitates produced by strain 168 were calcite, while no mineral has been formed in abiotic experiments. The values of δ13CCaCO3 fluctuated around −5.2‰ in Bio-standing experiments, whereas δ13CCaCO3 in Ino-standing experiments ranged from −14.1‰ to −13.1‰. The carbon isotope offset (Δ13CCaCO3–DIC) values increased from +0.8‰ to +7.6‰ with incubation and these in Ino-standing experiments increased from −2.3‰ to −0.2‰. These results indicate that bacteria participated in CIF and atmospheric CO2 is the dominant source of carbon in the carbonate minerals. An increase in pH and hydration of CO2 catalyzed by CA played synergetic roles in increasing the saturation index (SI) and accelerating the precipitation rate (R). The values of Δ13CCaCO3-DIC were found to be closely negatively correlated with SI (r = −0.86, P < 0.0001, n = 21), while no clear relationship in inorganic experiments. Moreover, the Δ13CCaCO3-DIC values increased synchronously with the LogR (r = 0.97, P < 0.0001, n = 21), while a negative correlation emerged in inorganic experiments (r = −0.93, P = 0.02, n = 5). Thus, a large CIF could be attributed to the vital effects of bacteria. The shaking condition can affect the CIF during MICP by increasing bacterial activity. These findings emphasize the importance of evaluating vital effects by bacteria during CIF to accurately reconstruct paleoenvironments and highlight the potential of biogenic carbonate minerals for CO2 sequestration.

A Novel Approach for Modeling and Evaluating Road Operational Resilience Based on Pressure-State-Response Theory and Dynamic Bayesian Networks

Urban roads face significant challenges from the unpredictable and destructive characteristics of natural or man-made disasters, emphasizing the importance of modeling and evaluating their resilience for emergency management. Resilience is the ability to recover from disruptions and is influenced by factors such as human behavior, road conditions, and the environment. However, current approaches to measuring resilience primarily focus on the functional attributes of road facilities, neglecting the vital feedback effects that occur during disasters. This study aims to model and evaluate road resilience under dynamic and uncertain emergency event scenarios. A new definition of road operational resilience is proposed based on the pressure-state-response theory, and the interaction mechanism between multidimensional factors and the stage characteristics of resilience is analyzed. A method for measuring road operational resilience using Dynamic Bayesian Networks (DBN) is proposed, and a hierarchical DBN structure is constructed based on domain knowledge to describe the influence relationship between resilience elements. The Best Worst method (BWM) and Dempster–Shafer evidence theory are used to determine the resilience status of network nodes in DBN parameter learning. A road operational resilience cube is constructed to visually integrate multidimensional and dynamic road resilience measurement results obtained from DBNs. The method proposed in this paper is applied to measure the operational resilience of roads during emergencies on the Shanghai expressway, achieving a 92.19% accuracy rate in predicting resilient nodes. Sensitivity analysis identifies scattered objects, casualties, and the availability of rescue resources as key factors affecting the rapidity of response disposal in road operations. These findings help managers better understand road resilience during emergencies and make informed decisions.

Hypoxia stress induces complicated miRNA responses in the gill of Chinese mitten crab (Eriocheir sinensis)

Hypoxia caused by global climate change and human activities has become a growing concern eliciting serious damages to aquatic animals. microRNAs (miRNAs) as non-coding regulatory RNAs exert vital effects on hypoxia responses. Chinese mitten crab (Eriocheir sinensis) with the habitat on the sediment surface or the pond bottom is susceptible to oxygen deficiency. However, whether miRNAs are involved in the response of the crabs to hypoxia stress remains enigmas. In this study, we conducted the whole transcriptome-based miRNA-mRNA integrated analysis of Chinese mitten crab gill under hypoxic condition for 3 h and 24 h We found that the acute hypoxia induces complex miRNA responses with the extensive influences on their target genes that engaged in various bio-processes, especially those associated with immunity, metabolism and endocrine. The impact of hypoxia on crab miRNAs is severer, as the exposure lasts longer. In response to the dissolved oxygen fluctuation, the HIF-1 signaling is activated by miRNAs to cope with the hypoxia stress through strategies including balancing inflammatory and autophagy involved in immunity, changing metabolism to reducing energy consumption, and enhancing oxygen-carrying and delivering capacities. The miRNAs and their corresponding target genes engaged in hypoxia response were intertwined into an intricate network. Moreover, the top hub molecular, miR-998-y and miR-275-z, discovered from the network might serve as biomarkers for hypoxia response in crabs. Our study provides the first systemic miRNA profile of Chinese mitten crab induced by hypoxia stress, and the identified miRNAs and the interactive network add new insights into the mechanism of hypoxia response in crabs.

Temperature-dependent oxygen isotope fractionation in otoliths of juvenile Chinook salmon (Oncorhynchus tshawytscha)

Oxygen thermometry has become a widely used technique for reconstructing thermal history in calcifying organisms but interpretation can be subject to predictive error from vital effects. To better understand these processes in Chinook salmon (Oncorhynchus tshawytscha) we experimentally constructed a temperature-dependent, otolith–water fractionation relationship for oxygen isotopes (δ18O) by rearing post-yolk absorptive juvenile fish at nominal temperatures from 6 to 21 °C. Temperature and otolith precipitation rate had significant effects on the otolith–water δ18O fractionation, but somatic growth rate did not. The slope of the δ18O fractionation equation also differed significantly from that of synthetic aragonite. Our results suggest the expression of kinetic effects on δ18O fractionation in otoliths of Chinook salmon that are increasingly constrained at higher temperatures by other physical and physiological processes involved in mineral formation. Species-specific δ18O fractionation equations have considerable utility to reconstruct temperature history in Pacific salmon, but applications should recognize the potential for inferential uncertainty arising from interacting vital effects.

Effects of Shaft Tuyere Parameters on Gas Movement Behavior and Burden Reduction in Oxygen Blast Furnace

Parameters of shaft tuyere have vital effects on the gas flow distribution and working condition in the TGR-OBF, which determine the production index, CO2 emission reduction, and economic benefit. To clarify the effects of shaft tuyere parameters on gas movement behavior and burden reduction in oxygen blast furnaces, a 2D steady-state model based on actual plant conditions in China is published in this study. The shaft of the blast furnace can be divided into region I near the wall and region II close to the center, which was influenced by top gas and bosh gas, respectively. The farthest movement distance of the top gas along the radial direction was defined as the penetration depth decided by its kinetic energy ratio. As the height of shaft tuyere decreased from 5/10 L to 1/10 L, the penetration depth decreased from 1.615 m to 1.308 m, and the reduction degree of iron-bearing burden before entering the cohesive zone increased from 0.925 to 0.982. With the shaft tuyere diameters increased from 0.088 m to 0.096 m with a constant blast velocity, the penetration depth was kept elongated at 1.24 m, and the reduction degree before entering the cohesive zone increased from 0.972 to 0.983. While the blast volume of top gas was kept constant, the reduction degree before entering the cohesive zone increased from 0.969 to 0.986. When the shaft tuyere angles increased from −20° to 20°, both the distribution of temperature and CO fraction moved towards the upper shaft slightly, and the penetration depth was kept around 1.24. Under experimental conditions, a low-height shaft tuyere was appropriate for an oxygen blast furnace. Within a certain control range, the changes of shaft tuyere diameters and angles had a small effect on the oxygen blast furnace.

Histological changes of electric yellow (Labidochromis caeruleus) exposed to three different copper concentrations

The water pollution is affecting rivers, lakes, and seas. Therefore, all aquatic organiss may influenced by it. In this study, it was intended to examine and assess histological changes in the electric yellow cichlid exposed to three different periods of copper concentrations (acute, chronic and not containing copper). Firstly, this study was formed in three parts of acute and chronic exposures and recovery. Electric yellow cichlid were exposed to 0, 10, 20, 30, 40 mg l-1 of copper sulfate for 96-h acute trial. Secondly, they were exposed to 0.0, 0.5, 1.0, 2.0, 4.0 mg l-1 of copper sulfate for 20-d chronic trial. Thirdly, survived fish from the chronic trial were holded in clean water without copper for 10-d recovery. At the end of three trials, gill, liver and spleen samples of fish were collected and stained with hematoxylin-eosin (H&amp;E) techniques. Preparations were examined and detected by the light microscope and significant pictures were saved by the digital camera. As a results of acute and chronic copper trials, edema, aneurism and serious degenerations of gills, necrosis and vacuolations in the hepatocytes and blood vessels of liver, and degenerations, granulamas and black spots in the spleen were indicated. It is detected that copper had vital effects on physiology of electric yellow cichlid and caused important tissue damages in fish.

The effects of GPER on age-associated memory impairment induced by decreased estrogen levels.

Estrogen, as a pleiotropic endocrine hormone, not only regulates the physiological functions of peripheral tissues but also exerts vital neuroregulatory effects in the central nervous system (CNS), such as the development of neurons and the formation of neural network connections, wherein rapid estrogen-mediated reactions positively stimulate spinogenesis and regulate synaptic plasticity and synaptic transmission to facilitate cognitive and memory performance. These fast non-genomic effects can be initiated by membrane-bound estrogen receptors (ERs), three best known of which are ERα, ERβ, and G protein-coupled estrogen receptor (GPER). To date, the effects of ERα and ERβ have been well studied in age-associated memory impairment, whereas there is still a lack of attention to the role of GPER in age-associated memory impairment, and there are still disputes about whether GPER indeed functions as an ER to enhance learning and memory. In this review, we provide a systematic overview of the role of GPER in age-associated memory impairment based on its expression, distribution, and signaling pathways, which might bring some inspiration for translational drugs targeting GPER for age-related diseases and update knowledge on the role of estrogen and its receptor system in the brain.

Nonstructural proteins 2B and 4A of Tembusu virus induce complete autophagy to promote viral multiplication in vitro

Tembusu virus (TMUV) is an emerging flavivirus that has broken out in different regions of China. TMUV infection has been reported to induce autophagy in duck embryo fibroblast cells. However, the molecular mechanisms underlying this autophagy induction remain unclear. Here, we explored the interactions between autophagy and TMUV and the effects of the structural and nonstructural proteins of TMUV on autophagy in vitro. Among our results, TMUV infection enhanced autophagy to facilitate viral replication in HEK293T cells. After pharmacologically inducing autophagy with rapamycin (Rapa), the replication of TMUV increased by a maximum of 14-fold compared with the control group. To determine which TMUV protein primarily induced autophagy, cells were transfected with two structural proteins and seven nonstructural proteins of TMUV. Western blotting showed that nonstructural proteins 2B (NS2B) and 4 A (NS4A) of TMUV significantly induced the conversion of microtubule-associated protein 1 light chain 3 (LC3) from LC3-I to LC3-II in HEK293T cells. In addition, through immunofluorescence assays, we found that NS2B and NS4A significantly increased the punctate fluorescence of GFP-LC3-II. Furthermore, we found that both NS2B and NS4A interacted with polyubiquitin-binding protein sequestosome 1 (SQSTM1/p62) in a coimmunoprecipitation assay. Moreover, the autophagic degradation of p62 and LC3 mediated by NS2B or NS4A was inhibited by treatment with the autophagic flux inhibitor chloroquine (CQ). These results confirmed the vital effects of NS2B and NS4A in TMUV-induced complete autophagy and clarified the importance of complete autophagy for viral replication, providing novel insight into the relationship between TMUV and autophagy.

Diagenetic and Biological Overprints in Geochemical Signatures of the Gigantoproductus Tertiary Layer (Brachiopoda): Assessing the Paleoclimatic Interpretation

Variations in the geochemical signatures of fossil brachiopod shells may be due to diagenesis and/or biological processes (i.e., 'vital effects'). It is critical to characterise them in order to identify reliable shell areas suitable for paleoclimate studies. This investigation contributes to an in-depth understanding of geochemical variations in Gigantoproductus sp. shells (SW Spain, Serpukhovian age), throwing light onto the Late Paleozoic Ice Age interpretation. Microstructural, crystallographic, cathodoluminescence and geochemical (minor and trace elements, δ18O, δ13C, and strontium isotopes) characterisations have been performed on the tertiary layer of the ventral valve, to assess the preservation state. Poorly preserved areas exhibit microstructural and geochemical changes such as recrystallisation, fracturing and higher Mn and Fe enrichment. Moreover, these areas have a higher dispersion of ⁸⁶Sr, ⁸⁷Sr, δ18O and δ13C than well-preserved areas. Three structural regions have been identified in well-preserved areas of the ventral valve by differences in valve curvature and thickness, such as the umbonal and thick and thin regions. These regions have different proportions of Mg, S, Na, δ18O, and δ13C, which are interpreted as 'vital effects' and probably related to growth-rate differences during shell growth. The Gigantoproductus tertiary layer seems the most suitable for paleoclimate studies, because it retains the original microstructure and geochemical composition.

Experimental study on self–emulsification of shale crude oil by natural emulsifiers

Self–emulsification can be accomplished by enhanced oil recovery (EOR), the realization of the exploration of natural emulsifiers, which is a crucial task to understand the mechanism of crude oil self–emulsification, albeit it is, of course, accompanied by difficulties, during the development of shale crude oil. In this study, we separated the active components of crude oil, and with the help of modern characterization and laboratory tests, coupled with nuclear magnetic resonance of core flooding method, we fully explored the independent and synergistic effects of crude oil active components, and deepened the understanding of the mechanism of crude oil self–emulsification. Among the active components of crude oil, asphaltene and resin have vital effects on its self–emulsification, which is shown in the amphiphilic structure of asphaltene and the effect of resin solvent. Asphaltene can reduce oil–water interfacial tension to 19 mN/m, and the resin significantly increase the viscosity of emulsion. Meanwhile, resin and asphaltene stabilize the viscoelasticity of oil–water interface films and affect the phase transition of emulsions in different water oil ratio environment. As a result, the active components of crude oil are closely related to formation and stabilization of the emulsion, which together endue the inherent conditions of its self–emulsification. Core flooding test confirmed that some emulsions in nanoscale size are produced in shale porous media, and the average emulsion diameter size is 181 nm. This study explored the effects of natural emulsifiers on the self–emulsification of crude oil, thereby promising new potential opportunities for EOR of shale oil.

Biologically driven isotopic fractionations in bivalves: from palaeoenvironmental problem to palaeophysiological proxy.

Traditional bulk stable isotope (δ18 O and δ13 C) and clumped isotope (Δ47 ) records from bivalve shells provide invaluable histories of Earth's local and global climate change. However, biologically driven isotopic fractionations (BioDIFs) can overprint primary environmental signals in the shell. Here, we explore how conventional measurements of δ18 O, δ13 C, and Δ47 in bivalve shells can be re-interpreted to investigate these physiological processes deliberately. Using intrashell Δ47 and δ18 O alignment as a proxy for equilibrium state, we separately examine fractionations and/or disequilibrium occurring in the two major stages of the biomineralisation process: the secretion of the extrapallial fluid (EPF) and the precipitation of shell material from the EPF. We measured δ18 O, δ13 C, and Δ47 in fossil shells representing five genera (Lahillia, Dozyia, Eselaevitrigonia, Nordenskjoldia, and Cucullaea) from the Maastrichtian age [66-69 million years ago (Ma)] López de Bertodano Formation on Seymour Island, Antarctica. Material was sampled from both the outer and inner shell layers (OSL and ISL, respectively), which precipitate from separate EPF reservoirs. We find consistent δ18 O values across the five taxa, indicating that the composition of the OSL can be a reliable palaeoclimate proxy. However, relative to the OSL baseline, ISLs of all taxa show BioDIFs in one or more isotopic parameters. We discuss/hypothesise potential origins of these BioDIFs by synthesising isotope systematics with the physiological processes underlying shell biomineralisation. We propose a generalised analytical and interpretive framework that maximises the amount of palaeoenvironmental and palaeobiological information that can be derived from the isotopic composition of fossil shell material, even in the presence of previously confounding 'vital effects'. Applying this framework in deep time can expand the utility of δ18 O, δ13 C, and Δ47 measurements from proxies of past environments to proxies for certain biomineralisation strategies across space, time, and phylogeny among Bivalvia and other calcifying organisms.