Experimental analysis of matrix moveable oil saturation in tight sandstone reservoirs of the south Ordos Basin,China

Tight oil reservoirs in the south Ordos Basin are characterized by fractured,heterogeneous oil-bearing strata(an oil saturation of less than 55%on average),normal pressure(0.8±)and extra-low permeability(less than 0.3 mD).In the Chang 8 tight sandstone reservoir in Honghe oilfield,micro-and nanopores,especially those with a pore-throat radius of less than 1 mm,account for more than 90%.Fluid flow in the matrix is non-linear and crude oil flow rates are very low under normal pressure gradients.An improved understanding of oil mobility in a tight matrix is key to further development of normalpressure tight-oil resources in the continental basin.In this study,constant-velocity and high-pressure mercury injection experiments were conducted using samples of typical tight sandstone cores obtained from the south of Ordos Basin.A new method for reconstructing the full-scale pore-throat distribution characteristics of tight sandstone reservoirs was established successfully,based on which multistage centrifugal tests,tests of low-pressure differential displacement of oil by water,and nuclear magnetic resonance tests were conducted in order to obtain the distribution characteristics of moveable fluid in different pores.The moveable oil saturation(MOS)and degree of oil recovery(i.e.ratio of accumulative oil production to producing geologic reserves)of the core samples under different differential pressures for displacement were determined.As for the tight oil reservoirs in the south Ordos Basin,the moveable fluids are mainly stored in sub-micron(0.10-0.5 mm)pores.For Type I reservoirs(k>0.1 mD),the volume percentage of moveable fluid in pores with a radius larger than 0.5 mm is relatively high(greater than 40%).The degree of oil recovery of water flooding serves as the basis for forecasting recoverable reserves for tight oil reservoirs.Recoverable reserves under water flooding,mainly occur in pores with a radius greater than 0.5 mm.The contribution of Type I reserves to oil production is observed to be greater than 60%,and the degree of oil recovery reaches up to 17.1%.These results help improve our understanding on the evaluation and classification of Chang 8 tight sandstone reservoirs in Honghe oilfield and serve as theoretical basis for pilot tests to explore effective injection media and development methods to improve the matrix-driven pressure differences and displacement efficiency for oil.

“Three‐in‐one”strategy:Heat regulation and conversion enhancement of a multifunctional separator for safer lithium-sulfur batteries

The safety problems encountered with lithium–sulfur batteries(LSBs)hinder their development for practical applications.Herein,a highly thermally conductive separator was constructed by cross‐weaving super‐aligned carbon nanotubes(SA‐C)on super‐aligned boron nitride@carbon nanotubes(SA‐BC)to create a composite film(SA‐BC/SA‐C).This separator was used to fabricate safe LSBs with improved electrochemical performance.The highly aligned separator structure created a uniform thermal field that could rapidly dissipate heat accumulated during continuous operation due to internal resistance,which prevented the development of extremely high temperatures.The array of boron nitride nanosheets endowed the composite separator with a large number of adsorption sites,while the highly graphitized carbon nanotube skeleton accelerated the catalytic conversion of high‐valence polysulfides into low‐valence polysulfides.The arrayed molecular brush design enabled the regulation of local current density and ion flux,and considerably alleviated the growth of lithium dendrites,thus promoting the smooth deposition of Li metal.Consequently,a battery constructed with the SA‐BC/SA‐C separator showed a good discharge capacity of 685.2 mAh g−1 over 300 cycles(a capacity decay of 0.026%per cycle)at 2 C and 60°C.This“three‐in‐one”multifunctional separator design strategy constitutes a new path forward for overcoming the safety problems of LSBs.

SuperFeat:Quantitative Feature Learning from Single-cell RNA-seq Data Facilitates Drug Repurposing

In this study,we devised a computational framework called Supervised Feature Learning and Scoring(SuperFeat)which enables the training of a machine learning model and evaluates the canonical cellular statuses/features in pathological tissues that underlie the progression of disease.This framework also enables the identification of potential drugs that target the presumed detrimental cellular features.This framework was constructed on the basis of an artificial neural network with the gene expression profiles serving as input nodes.The training data comprised single-cell RNA sequencing datasets that encompassed the specific cell lineage during the developmental progression of cell features.A few models of the canonical cancer-involved cellular statuses/features were tested by such framework.Finally,we illustrated the drug repurposing pipeline,utilizing the training parameters derived from the adverse cellular statuses/features,which yielded successful validation results both in vitro and in vivo.SuperFeat is accessible at https://github.com/weilin-genomics/rSuperFeat.

The effect of NiO-Ni_(3)N interfaces in in-situ formed heterostructure ultrafine nanoparticles on enhanced polysulfide regulation in lithium-sulfur batteries

Inhibiting the “shuttle effect” of soluble polysulfides and improving reaction kinetics are the key factors necessary for further exploration of high-performance Li-S batteries. Herein, an effective interface engineering strategy is reported, wherein nitriding of an Ni-based precursor is controlled to enhance Li-S cell regulation. The resulting in-situ formed NiO-Ni_(3)N heterostructure interface not only has a stronger polysulfide adsorption effect than that of monomeric NiO or Ni_(3)N but also has a faster Li ion diffusion ability than a simple physical mixture. More importantly, this approach couples the respective advantages of NiO and Ni_(3)N to reduce polarization and facilitate electron transfer during polysulfide reactions and synergistically catalyze polysulfide conversion. In addition, ultrafine nanoparticles are thought to effectively improve the use of additive materials. In summary, Li-S batteries based on this NiO-Ni_(3)N heterostructure have the features of long cycle stability, rapid charging-discharging, and good performance under high sulfur loading.

Protective role of retinoid X receptor in H9c2 cardiomyocytes from hypoxia/reoxygenation injury in rats

BACKGROUND: Retinoid X receptor(RXR) plays a central role in the regulation of intracellular receptor signaling pathways. The activation of RXR has protective effect on H2O2-induced apoptosis of H9c2 ventricular cells in rats. But the protective effect and mechanism of activating RXR in cardiomyocytes against hypoxia/reoxygenation(H/R)-induced oxidative iniury are still unclear.METHODS: The model of H/R injury was established through hypoxia for 2 hours and reoxygenation for 4 hours in H9c2 cardiomyocytes of rats. 9-cis-retinoic acid(9-cis RA) was obtained as an RXR agonist, and HX531 as an RXR antagonist. Cultured cardiomyocytes were randomly divided into four groups: sham group, H/R group, H/R+9-cis RA-pretreated group(100 nmol/L 9-cis RA), and H/R+9-cis RA+HX531-pretreated group(2.5 μmol/L HX531). The cell viability was measured by MTT, apoptosis rate of cardiomyocytes by flow cytometry analysis, and mitochondrial membrane potential(ΔΨm) by JC-1 fluorescent probe, and protein expressions of Bcl-2, Bax and cleaved caspase-9 with Western blotting. All measurement data were expressed as mean±standard deviation, and analyzed using one-way ANOVA and the Dunnett test. Differences were considered signif icant when P was <0.05.RESULTS: Pretreatment with RXR agonist enhanced cell viability, reduced apoptosis ratio, and stabled ΔΨm. Dot blotting experiments showed that under H/R stress conditions, Bcl-2 protein level decreased, while Bax and cleaved caspase-9 were increased. 9-cis RA administration before H/R stress prevented these effects, but the protective effects of activating RXR on cardiomyocytes against H/R induced oxidative injury were abolished when pretreated with RXR pan-antagonist HX531.CONCLUSION: The activation of RXR has protective effects against H/R injury in H9c2 cardiomyocytes of rats through attenuating signaling pathway of mitochondria apoptosis.

Excitatory amino acid changes in the brains of rhesus monkeys following selective cerebral deep hypothermia and blood flow occlusion

Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large amount of excitatory amino acids after cerebral ischemia is the major mechanism underlying ischemic brain injury and nerve cell death. In the present study, we used selective cerebral deep hypothermia and blood flow occlusion to block the bilateral common carotid arteries and/or bilateral vertebral arteries in rhesus monkey, followed by reperfusion using Ringer＇s solution at 4~C. Microdialysis and transmission electron microscope results showed that selective cerebral deep hypothermia and blood flow occlusion inhibited the release of glutamic acid into the extracellular fluid in the brain frontal lobe and relieved pathological injury in terms of the ultrastructure of brain tissues after severe cerebral ischemia. These findings indicate that cerebral deep hypothermia and blood flow occlusion can inhibit cytotoxic effects and attenuate ischemic/ hypoxic brain injury through decreasing the release of excitatory amino acids, such as glutamic acid.

Distribution of nitrogen and oxygen compounds in shale oil distillates and their catalytic cracking performance

The positive-and negative-ion electrospray ionization(ESI)coupled with Fourier transform-ion cyclotron resonance mass spectrometry(FT-ICR MS)was employed to identify the chemical composition of heteroatomic compounds in four distillates of Fushun shale oil,and their catalytic cracking performance was investigated.There are nine classes of basic nitrogen compounds(BNCs)and eleven classes of non-basic heteroatomic compounds(NBHCs)in the different distillates.The dominant BNCs are mainly basic N1 class species.The dominant NBHCs are mainly acidic O2 and O1 class species in the300-350℃,350-400℃,and 400-450℃distillates,while the neutral N1,N1 O1 and N2 compounds become relatively abundant in the>450℃fraction.The basic N1 compounds and acidic O1 and O2 compounds are separated into different distillates by the degree of alkylation(different carbon number)but not by aromaticity(different double-bond equivalent values).The basic N1 O1 and N2 class species and neutral N1 and N2 class species are separated into different distillates by the degrees of both alkylation and aromaticity.After the catalytic cracking of Fushun shale oil,the classes of BNCs in the liquid products remain unchanged,while the classes and relative abundances of NBHCs vary significantly.

The primary use of artificial intelligence in cardiovascular diseases: what kind of potential role does artificial intelligence play in future medicine?

Cardiovascular diseases (CVD) is a major threat to human health and the leading cause of death worldwide.[1] The incidence of CVD caused 17.6 million deaths in 2016, an increase of 14.5% from 2006 to 2016.[2] Unfortunately, the mortality and morbidity rates of CVD are increasing year by year, especially in developing regions. Studies have shown that approximately 80% of CVD-related deaths occur in low- and middle-income countries. Besides, these deaths occur at a younger age than in high-income countries.[3]?

Characteristics of diffusion-tensor imaging for healthy adult rhesus monkey brains

Diffusion-tensor imaging can be used to observe the microstructure of brain tissue. Fractional ani- sotropy reflects the integrity of white matter fibers. Fractional anisotropy of a young adult brain is low in gray matter, high in white matter, and highest in the splenium of the corpus callosum. Thus, we selected the anterior and posterior limbs of the internal capsule, head of the caudate nucleus, semioval center, thalamus, and corpus callosum （splenium and genu） as regions of interest when using diffusion-tensor imaging to observe fractional anisotropy of major white matter fiber tracts and the deep gray matter of healthy rhesus monkeys aged 4-8 years. Results showed no laterality dif- ferences in fractional anisotropy values. Fractional anisotropy values were low in the head of cau- date nucleus and thalamus in gray matter. Fractional anisotropy values were highest in the sple- nium of corpus callosum in the white matter, followed by genu of the corpus callosum and the pos- terior limb of the internal capsule. Fractional anisotropy values were lowest in the semioval center and posterior limb of internal capsule. These results suggest that fractional anisotropy values in major white matter fibers and the deep gray matter of 4-8-year-old rhesus monkeys are similar to those of healthy young people.

Assessment of intraoperative oxygenation function and trauma degree of PCV-VG and VCV mode for elderly patients with laparoscopic abdominal surgery

Objective:To study the intraoperative oxygenation function and trauma degree of pressure-controlled ventilation-volume guaranteed (PCV-VG) and volume-controlled ventilation (VCV) mode for elderly patients with laparoscopic abdominal surgery. Methods:60 elderly patients with laparoscopic abdominal surgery were selected for study and randomly divided into two groups (n=30), group A received ventilation in accordance with sequential VCV-PCV-VG mode, group B received ventilation in accordance with the sequential PCV-VG-VCV mode, and the respiratory function parameters and arterial blood gas parameters and serum damage indexes were determined before the start of pneumoperitoneum (T0), 1 h after the start of the first ventilation mode after the start of pneumoperitoneum (T1), 1 h after the switch of ventilation mode (T2) and after the end of pneumoperitoneum (T3). Results:At T1, Ppeak, mean airway pressure (Pmean) and plateau airway pressure (Pplant) of group A were significantly higher than those of group B (P<0.05), partial pressure of oxygen (PaO2) was significantly lower than that of group B (P<0.05), and pulse oxygen saturation (SpO2) and partial pressure of carbon dioxide (PaCO2) were not significantly different from those of group B;at T2 and T3, Ppeak, Pmean and Pplant of group A were significantly lower than those of group B (P<0.05), PaO2 were significantly lower than those of group B (P<0.05), and SpO2 and PaCO2 were not significantly different from those of group B. At T1, serum soluble receptor for advanced glycation end-product (sRAGE), KL-6 (krebs. von den Iungen-6), tumor necrosis factor-α(TNF-α) and malondialdehyde (MDA) content of group A were significantly higher than those of group B (P<0.05);at T3, serum sRAGE, KL-6, TNF-αand MDA content of group A were significantly lower than those of group B (P<0.05). Conclusions:PCV-VG mode for elderly patients with laparoscopic abdominal surgery can reduce airway pressure, improve lung compliance and alveolar oxidation, and reduce lung injury and systemic trauma.

Research progress in performance improvement strategies and sulfur conversion mechanisms of Li-S batteries based on Fe series nanomaterials

Lithium-sulfur(Li-S)batteries hold the potential to revolutionize energy storage due to the high theoretical capacity and energy density.However,the commercialization process is seriously hindered by the rapid capacity decay and low utilization of sulfur,caused by the inevitable slow dynamics and the“shuttle effect”.The incorporation of metal-based electrocatalysts into sulfur cathodes shows promise in promoting the conversion of lithium polysulfides(LiPSs),reducing the“shuttle effect”,and enhancing cell kinetics and cycle life.Among these,Fe-based materials,characterized by environmental friendliness,low cost,abundant reserves,and high activity,are extensively used in sulfur cathode modification.This article reviews the advancements of Fe-based materials in enhancing Li-S batteries in recent years.Starting from single/multi-component Fe-based metal compounds and single/bimetallic atoms,the influence of different Fe coordination environments on the conversion mechanism of LiPSs is analyzed.It is hoped that this review and the proposed prospects can further stimulate the development and application of the Fe element in Li-S batteries in the future.

Chinese expert consensus on the management of aneurysmal subarachnoid hemorrhage-related hydrocephalus

Aneurysmal subarachnoid hemorrhage-related hydrocephalus(aSAH-H)refers to a clinical syndrome of excessive secretion,obstructive absorption,or circulatory disturbance of cerebrospinal fluid(CSF)with subarachnoid hemorrhage following rupture of aneurysm that leads to excessive accumulation of intracranial CSF and enlargement of ventricles impairing neurological function.aSAH is an important risk factor for hydrocephalus[1,2].According to fluid dynamics,aSAH-H is divided into communicating and obstructive hydrocephalus;according to the time of occurrence.

The desumoylating enzyme sentrin-specific protease 3 contributes to myocardial ischemia reperfusion injury

Sentrin-specific protease 3（SENP3）, a member of the desumoylating enzyme family, is known as a redox sensor and could regulate multiple cellular signaling pathways. However, its implication in myocardial ischemia reperfusion（MIR） injury is unclear. Here, we observed that SENP3 was expressed and upregulated in the mouse heart depending on reactive oxygen species（ROS） production in response to MIR injury. By utilizing si RNA-mediated cardiac specific gene silencing, SENP3 knockdown was demonstrated to significantly reduce MIR-induced infarct size and improve cardiac function. Mechanistic studies indicated that SENP3 silencing ameliorated myocardial apoptosis mainly via suppression of endoplasmic reticulum（ER） stress and mitochondrial-mediated apoptosis pathways. By contrast, adenovirusmediated cardiac SENP3 overexpression significantly exaggerated MIR injury. Further molecular analysis revealed that SENP3 promoted mitochondrial translocation of dynamin-related protein 1（Drp1） in reperfused myocardium. In addition, mitochondrial division inhibitor-1（Mdivi-1）, a pharmacological inhibitor of Drp1, significantly attenuated the exaggerated mitochondrial abnormality and cardiac injury by SENP3 overexpression after MIR injury. Taken together, we provide the first direct evidence that SENP3 upregulation pivotally contributes to MIR injury in a Drp1-dependent manner, and suggest that SENP3 suppression may hold therapeutic promise for constraining MIR injury.

HACE1-mediated NRF2 activation causes enhanced malignant phenotypes and decreased radiosensitivity of glioma cells

HACE1,an E3 ubiquitin-protein ligase,is frequently inactivated and has been evidenced as a putative tumor suppressor in different types of cancer.However,its role in glioma remains elusive.Here,we observed increased expression of HACE1 in gliomas related to control subjects,and found a strong correlation of high HACE1 expression with poor prognosis in patients with WHO grade III and IV as well as low-grade glioma(LGG)patients receiving radiotherapy.HACE1 knockdown obviously suppressed malignant behaviors of glioma cells,while ectopic expression of HACE1 enhanced cell growth in vitro and in vivo.Further studies revealed that HACE1 enhanced protein stability of nuclear factor erythroid 2-related factor 2(NRF2)by competitively binding to NRF2 with another E3 ligase KEAP1.Besides,HACE1 also promoted internal ribosome entry site(IRES)-mediated mRNA translation of NRF2.These effects did not depend on its E3 ligase activity.Finally,we demonstrated that HACE1 dramatically reduced cellular ROS levels by activating NRF2,thereby decreasing the response of glioma cells to radiation.Altogether,our data demonstrate that HACE1 causes enhanced malignant phenotypes and decreased radiosensitivity of glioma cells by activating NRF2,and indicate that it may act as the role of prognostic factor and potential therapeutic target in glioma.

Kinetic analysis of γ-glutamyltransferase reaction process for measuring activity via an integration strategy at low concentrations of γ-glutamyl p-nitroaniline

At 0.12 mmol/L γ-glutamyl p-nitroaniline(GGPNA),an improved integrated method was developed for kinetic analysis of γ-glutamyltransferase(GGT) reaction process and the integration with the classical initial rate method to measure serum GGT.For the improved integrated method,an integrated rate equation,which used the predictor variable of reaction time and considered inhibitions by both GGPNA and products,was nonlinearly fit to GGT reaction processes.For the integration strategy,classical initial rates were estimated when GGPNA consumption percentages were below 50%;otherwise,maximal reaction rates of GGT were estimated by the improved integrated method and converted into initial rates according to the differential rate equation at 0.11 mmol/L GGPNA.The inte-gration strategy was validated using optimized GGT kinetic parameters and 10-s intervals to record reaction curves within 8.0 min.By the integration strategy,there was a linear response from 0.9 to 32.0 U/L GGT,coefficients of variation were below 3.5%for GGT from 8.0 to 32.0 U/L(n=5) ,and GGT activities in clinical sera responded linearly to their classical initial rates at 2.00 mmol/L GGPNA with an expected slope.Therefore,the integration strategy was successful in measuring GGT at 0.12 mmol/L GGPNA.

Targeting RAS phosphorylation in cancer therapy:Mechanisms and modulators

RAS,a member of the small GTPase family,functions as a binary switch by shifting between inactive GDP-loaded and active GTP-loaded state.RAS gain-of-function mutations are one of the leading causes in human oncogenesis,accounting for w19%of the global cancer burden.As a well-recognized target in malignancy,RAS has been intensively studied in the past decades.Despite the sustained efforts,many failures occurred in the earlier exploration and resulted in an‘undruggable’feature of RAS proteins.Phosphorylation at several residues has been recently determined as regulators for wild-type and mutated RAS proteins.Therefore,the development of RAS inhibitors directly targeting the RAS mutants or towards upstream regulatory kinases supplies a novel direction for tackling the anti-RAS difficulties.A better understanding of RAS phosphorylation can contribute to future therapeutic strategies.In this review,we comprehensively summarized the current advances in RAS phosphorylation and provided mechanistic insights into the signaling transduction of associated pathways.Importantly,the preclinical and clinical success in developing anti-RAS drugs targeting the upstream kinases and potential directions of harnessing allostery to target RAS phosphorylation sites were also discussed.

A targeted nanoplatform co-delivery of pooled siRNA and doxorubicin for reversing of multidrug resistance in breast cancer

Multi-drug resistance(MDR)has become the largest obstacle to the success of cancer patients receiving traditional chemotherapeutics or novel targeted drugs.Here,we developed a targeted nanoplatform based on biodegradable boronic acid modifiedε-polylysine to co-deliver P-gp siRNA,Bcl-2 siRNA,and doxorubicin for overcoming the challenge.The targeted nanoplatform showed a robust suppressing efficiency for the invasion,proliferation,and colony formation of adriamycin(ADR)resistant breast cancer cell line(MCF-7/ADR)cells in vitro.The ATP responsiveness of the nanoplatform was also proved in the research.In the in vivo antitumor experiment,the targeted nanoplatform showed a significant inhibition of tumor growth with good biocompatibility.The goal of this study is to develop a novel and facile strategy to prepare a highly efficient and safe gene and drug delivery system for MDR breast cancer based on biocompatibleε-polylysine polymers.

Exploring COVID-19 at the single-cell level:a narrative review

The coronavirus disease 2019 (COVID-19) pandemic has been an unmitigated disaster for society and the economy worldwide. However, much remains unknown about the pathogenesis of, treatment methods for, and preventive measures against COVID-19. Single-cell sequencing is a novel sequencing technology whose use has recently become prevalent in various life-science fields. This high-resolution technology is being used to analyze the COVID-19 pandemic at a single-cell level. In this review, we summarize the application of single-cell sequencing technology to the field of COVID-19-related research, including the biology of severe acute respiratory syndrome coronavirus 2, clinical concerns associated with COVID-19, neutralizing antibody screening, and vaccine development. We also address challenges to, and improvements in, existing single-cell research related to COVID-19.