Pilot Test for Nitrogen Foam Flooding in Low Permeability Reservoir

Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.

An SU(3) Electroweak Unified Model Using Generalized Yang-Mills Theory

Generalized Yang-Mills theory has a covariant derivative which contains both vector and scalar gauge bosons. Based on this theory, we construct an SU(3) unified model of electromagnetic and weak interactions to simplify the Weinberg-Salam model. By using the Nambu-Jona-Lasinio mechanism, the symmetry breaking can be realized dynamically. The masses of W±, Z0 are obtained and interactions between various particles are the same as that of the Weinberg-Salam model. At the same time, sin2 θw =1/4 can be given.

化妆品风险物质检测方法的研究进展

化妆品风险物质是指由化妆品原料带入、生产过程中产生或带入的,可能对人体健康造成潜在危害的物质。随着化妆品消费市场的不断扩大,人们安全意识的增强以及近些年来层出不穷的化妆品安全事件,显示我国目前的化妆品安全形势不容乐观,化妆品的属性为日用化学工业产品,且长期施用于人体皮肤表面,与使用者的健康和切身利益密切相关,化妆品风险物质作为化妆品安全性评估的重要部分,逐渐成为化妆品企业、监管部门以及广大消费者重点关注的对象。本文从化妆品风险物质的来源出发,结合风险评估的重要性以及化妆品风险物质可能对人体健康产生的影响,重点就所列举的化妆风险物质的检测方法、法规政策、风险评估等方面归纳了国内外化妆品风险物质的研究现状。

Studies on the Correlation between Germination and cAMP Content of Different Color Chlamydospores in Ustiloginoidea virens

Ustilaginoidea virens is the causal agent of a serious disease of rice. To reveal the relationship between germination and the 3'-5'-cyclic adenosine monophosphate(c AMP) content from the dormant(black or green-black) and non-dormant(yellow)chlamydospore in Ustiloginoidea virens,this study adopts ultrasonic-bath method and high-performance liquid chromatography(HPLC) method, for extraction c AMP content of the different color chlamydospore. The results demonstrated that, as for the freshly chlamydospores collected from the false smut balls during their germination, c AMP content of yellow chlamydospore appeared a slight growth during 0-12 h, and showed a rapid declining as the germination time extended(12-48 h). Above all, in yellow chlamydospores, the germination rate and the content of c AMP presented a very notably negative correlation(|r|=0.861 9>r0.01=0.834), but the correlation between germination rate and content of c AMP was not obvious in black chlamydospores. The germination rate and the content of c AMP presented a notably positive correlation under different storage period(0, 2, 4, 6, 8,10 months) of the two color chlamydospores(the yellow of chlamydospore: |r | = 0.785 1 > r0.05= 0.707; the black of chlamydospore: |r| = 0.957 9 > r0.05= 0.707).

内感受损伤对药物成瘾的影响及其机制研究进展

内感受,即人对身体内部信号的感知、整合解释和调节能力,在药物成瘾的形成、发展和治疗过程中起到重要作用.长期的药物使用导致成瘾者无法准确地识别管理来自身体内部的信号,并对与药物效应相关的身体信号过分敏感,其背后的神经基础是以岛叶为核心的内感受处理中枢的损伤.内感受的功能障碍可能导致个体对药物的过度依赖和无法自控.受损的内感受通过影响线索诱发的药物渴求、增加负性情绪和冲动、损伤风险决策能力导致成瘾者的复吸.本文探究内感受的损伤特征及其在药物成瘾过程中的作用,有助于识别药物成瘾形成的诱因、评估成瘾严重程度,为干预提供一个外周、中枢、行为和主观报告相结合的多维度靶点.未来的研究可从多模态评估内感受能力、建立内感受神经和心理表征的对应关系、探究不同药物的内感受损伤特征共性和特异性等方向进一步明确内感受在药物成瘾中的作用,并探索内感受作为跨诊断和共病干预的靶点的可行性.

An efficient approach for the treatment of radioactive waste perfluoropolyether lubricants via a synergistic effect of thermal catalysis and immobilization

Perfluoropolyether(PFPE)lubricants are a kind of high-molecular polymer with many excellent properties.However,the use of PFPEs in the nuclear industry can lead to partial decomposition and carrying radionuclides,resulting in a large amount of radioactive waste PFPE lubricants annually.Moreover,radioactive waste PFPE lubricants are difficult to be effectively treated due to their high stability,the risk of possible leakage of radionuclides,and hypertoxic fluorine-containing by-products.In this study,without any precedent,a strategy of Mn O_(2)-catalyzed decomposition and Na_(2)CO_(3)-immobilized conversion was proposed for PFPE lubricant decomposition and fluorine immobilization simultaneously based on the Lewis acid-base and oxygen vacancies concept.A high fluorine conversion efficiency of 95.4%was achieved.Meanwhile,the mechanism of decomposition suggested that Mn O_(2)mainly provided Lewis acid sites and attacked the(basic)fluorine or oxygen atoms in PFPE molecules.The decomposition of PFPE chains was proceed down and volatile fluorine-containing gas was released by partial electron transfer,intramolecular disproportionation reaction,and unzipping fashion.Subsequently,gas by-products could be further oxidized and then immobilized into fluoride salts by carbonate solid absorbents.Overall,this study provides a simple,safe,and potentially practical strategy for the harmless conversion of refractory fluorinated organic wastes,especially perfluoropolymers.

Andrographolide protects against atrial fibrillation by alleviating oxidative stress injury and promoting impaired mitochondrial bioenergetics

Atrial fibrillation(AF)is the most prevalent cardiac arrhythmia seen in clinical settings,which has been associated with substantial rates of mortality and morbidity.However,clinically available drugs have limited efficacy and adverse effects.We aimed to investigate the mechanisms of action of andrographolide(Andr)with respect to AF.We used network pharmacology approaches to investigate the possible therapeutic effect of Andr.To define the role of Andr in AF,HL-1 cells were pro-treated with Andr for 1 h before rapid electronic stimulation(RES)and rabbits were pro-treated for 1 d before rapid atrial pacing(RAP).Apoptosis,myofibril degradation,oxidative stress,and inflammation were determined.RNA sequencing(RNA-seq)was performed to investigate the relevant mechanism.Andr treatment attenuated RAP-induced atrial electrophysiological changes,inflammation,oxidative damage,and apoptosis both in vivo and in vitro.RNA-seq indicated that oxidative phosphorylation played an important role.Transmission electron microscopy and adenosine triphosphate(ATP)content assay respectively validated the morphological and functional changes in mitochondria.The translocation of nuclear factor erythroid 2-related factor 2(Nrf2)to the nucleus and the molecular docking suggested that Andr might exert a therapeutic effect by influencing the Keap1-Nrf2 complex.In conclusions,this study revealed that Andr is a potential preventive therapeutic drug toward AF via activating the translocation of Nrf2 to the nucleus and the upregulation of heme oxygenase-1(HO-1)to promote mitochondrial bioenergetics.

Mosquito CYP4C21 knockout reduces dengue virus and Zika virus replication in Aedes aegypti cells

Aedes aegypti(Ae.aegypti)is a major vector of dengue virus(DENV)and Zika virus(ZIKV).Understanding the complex interaction mechanisms between mosquito vectors and arboviruses is essential to interrupt virus trans-mission.This study constructed CYP4C21 knockout(KO)Aag2 cells(Ae.aegypti cells)and confirmed that CYP4C21 KO reduced DENV2 and ZIKV copies in Aag2 cells,which suggests that CYP4C21 may play an impor-tant role in mosquito infection with arboviruses.Furthermore,it is the first report of the CYP4 family related to viral infection,which lays the foundation for exploring the role of the CYP4C21 in the interaction of Ae.aegypti and arbovirus and provides novel insights into the function of cytochrome family proteins.

抗菌肽及类抗菌肽的设计、合成及应用

抗菌肽是大多数生物体中均存在的阳离子型短肽,其构成了生物免疫系统的重要部分。抗菌肽具有广谱高效的抗菌性和细胞选择性,其独特的膜破坏杀菌机制不易引起病原体的耐药性突变,有望成为新一代控制病原体的有效"抗生素"。但天然抗菌肽的提取成本高、产率低且周期长,不利于大规模生产推广,所以依托化学合成方法合成抗菌肽及其模拟聚合物应运而生。该方法为抗菌肽的设计及合成提供无限可能。本文介绍了抗菌肽的来源、结构和其作用机理并对现有的抗菌肽合成方法进行综述,阐述了现今抗菌肽及类抗菌肽的研究进展以及抗菌肽组装体的应用,最后对抗菌肽及类抗菌肽的发展前景作了展望,为开发高效、低毒的"新一代"抗生素提供重要信息和策略。

Effect of wall boundary condition on CFD simulation of CFB risers

The effect of solid-phase wall boundary condition on the numerical simulation of gas-solid flow in CFB risers containing FCC particles was investigated using the two-fluid model incorporating the kinetic theory of granular flow.Both the Gidaspow drag model and the EMMS-based drag model were used.The Johnson and Jackson(1987) wall boundary condition was applied to describe the interaction between particles and wall.Based on the experimental system of Li and Kwauk(1994),parametric studies of specularity coefficient(φ=1.0,0.6,0.0005,0.00005,0) and particle-wall restitution coefficient(e_w=0.6,0.9,0.95,0.99,0.999) were performed to evaluate their effects on axial voidage profile,solids flux,meso-scale and heterogeneous structures.Simulation results showed that solid-phase wall boundary condition had little effect on axial voidage profile when the Gidaspow drag model was used.However,the specularity coefficient φ had a pronounced influence on flow behavior when the EMMS-based drag model was used,and a small specularity coefficient(φ=0.00005,0) could result in better agreement with experimental data.The particle-wall restitution coefficient e_w plays but a minor role in the holistic flow characteristics.

Pure drug nano-assemblies: A facile carrier-free nanoplatform for efficient cancer therapy

Nanoparticulate drug delivery systems(Nano-DDSs) have emerged as possible solution to the obstacles of anticancer drug delivery. However, the clinical outcomes and translation are restricted by several drawbacks, such as low drug loading, premature drug leakage and carrier-related toxicity.Recently, pure drug nano-assemblies(PDNAs), fabricated by the self-assembly or co-assembly of pure drug molecules, have attracted considerable attention. Their facile and reproducible preparation technique helps to remove the bottleneck of nanomedicines including quality control, scale-up production and clinical translation. Acting as both carriers and cargos, the carrier-free PDNAs have an ultra-high or even100% drug loading. In addition, combination therapies based on PDNAs could possibly address the most intractable problems in cancer treatment, such as tumor metastasis and drug resistance. In the present review, the latest development of PDNAs for cancer treatment is overviewed. First, PDNAs are classified according to the composition of drug molecules, and the assembly mechanisms are discussed. Furthermore, the co-delivery of PDNAs for combination therapies is summarized, with special focus on the improvement of therapeutic outcomes. Finally, future prospects and challenges of PDNAs for efficient cancer therapy are spotlighted.

Association of human leukocyte antigen-DR-DQ-DP haplotypes with the risk of hepatitis B virus-related hepatocellular carcinoma

Aim:Genetic polymorphisms of human leukocyte antigen(HLA)class II molecules are associated with chronic hepatitis B virus(HBV)infection.We aimed to investigate the impacts of HLA-II haplotypes on viral evolution and the risks of HBV-caused liver diseases.Methods:HLA-DR-DQ-DP haplotypes were estimated in 1210 healthy controls,296 HBV clearance subjects,301 asymptomatic hepatitis B surface antigen carriers,770 chronic hepatitis B patients,443 HBV-related liver cirrhosis(LC)patients,and 1037 HBV-related hepatocellular carcinoma(HCC)patients.HBV mutations were determined by sequencing.The associations of HLA-DR-DQ-DP haplotypes with viral mutations and the risks of liver diseases were assessed by multivariate logistic regression.Results:Compared to HBV-free subjects,the haplotypes CCAACG,CCGACG,TCAATA,and TCGATA were associated with decreased HCC risk,with an odds ratio(OR)[95%confidence interval(CI)]of 0.62(0.40-0.95),0.60(0.39-0.92),0.73(0.54-0.98),and 0.58(0.42-0.78),respectively.CCAACG,CCGACG,and TCAATA were significantly associated with decreased frequencies of the HCC-risk HBV mutations:preS1 deletion,APOBECsignature HBV mutations in the core promoter and preS regions,A51C/T,G104C/T,and G146C/T.TCGATA and TTAACG were associated with increased LC risk,with an OR(95%CI)of 1.54(1.03-2.30)and 2.23(1.50-3.33),respectively.However,TCGATA and TTAACG were not consistently associated with the cirrhosis-risk HBV mutations.Conclusion:CCAACG,CCGACG,and TCAATA are inversely associated with HCC risk,possibly because they are involved in creating an immune microenvironment attenuating the generation of HCC-risk HBV mutations.TCGATA and TTAACG might predispose the polarity of immunity towards Th17 isotype related to LC.

Comparison between the Roles of Low-Level Jets in Two Heavy Rainfall Events over South China

Two heavy rainfall events occurred over the Pearl River Delta during 20-22 May 2020:the first was a warm-sector event and the second a frontal event.Based on ERA5 reanalysis data and observations from wind profilers and Doppler weather radars,the structures and roles of low-level jets(LLJs)during these two heavy rainfall events were analyzed.The results show that:(1)South China was affected by a low-level vortex and a low-level shear line during the two processes.The two heavy rainfall events were both associated with a synoptic-system-related low-level jet(SLLJ)and a boundary layer jet(BLJ).The coupling of the convergence at the exit of the BLJ and the divergence at the entrance of the SLLJ produced strong lifting for the warm-sector heavy rainfall,and the strong convergence between the LLJs and northerly winds as the cold front moved southwards was the main lifting reason for the frontal heavy rainfall.(2)The BLJ was the main transport of water vapor during the two processes.The coupling of the BLJ and SLLJ caused the water vapor convergence to be concentrated in the boundary layer during the first process,whereas the strong convergence between the LLJs and northerly winds led to the lower and middle troposphere having strong water vapor convergence during the second process.(3)During the period of these two heavy rainfall events,the lower and middle troposphere remained unstable.Further analysis show that the differences in the intensity,location,and direction between the BLJ and SLLJ resulted in the pseudo-equivalent potential temperature advection in the boundary layer being significantly larger than in the lower and middle troposphere,which compensated for the energy loss caused by heavy rainfall and maintained the convective instability.These findings add to our knowledge on the roles of LLJs in the pre-summer rainfall over South China.