Experimental study of the influencing factors and mechanisms of the pressure-reduction and augmented injection effect by nanoparticles in ultra-low permeability reservoirs

Nanoparticles(NPs)have gained significant attention as a functional material due to their ability to effectively enhance pressure reduction in injection processes in ultra-low permeability reservoirs.NPs are typically studied in controlled laboratory conditions,and their behavior in real-world,complex environments such as ultra-low permeability reservoirs,is not well understood due to the limited scope of their applications.This study investigates the efficacy and underlying mechanisms of NPs in decreasing injection pressure under various injection conditions(25—85℃,10—25 MPa).The results reveal that under optimal injection conditions,NPs effectively reduce injection pressure by a maximum of 22.77%in core experiment.The pressure reduction rate is found to be positively correlated with oil saturation and permeability,and negatively correlated with temperature and salinity.Furthermore,particle image velocimetry(PIV)experiments(25℃,atmospheric pressure)indicate that the pressure reduction is achieved by NPs through the reduction of wall shear resistance and wettability change.This work has important implications for the design of water injection strategies in ultra-low permeability reservoirs.

Nondegenerate Soliton Solutions of(2+1)-Dimensional Multi-Component Maccari System

For a multi-component Maccari system with two spatial dimensions,nondegenerate one-soliton and two-soliton solutions are obtained with the bilinear method.It can be seen by drawing the spatial graphs of nondegenerate solitons that the real component of the system shows a cross-shaped structure,while the two solitons of the complex component show a multi-solitoff structure.At the same time,the asymptotic analysis of the interaction behavior of the two solitons is conducted,and it is found that under partially nondegenerate conditions,the real and complex components of the system experience elastic collision and inelastic collision,respectively.

Peters异常PITX2及PAX6基因型表型分析

目的:分析中国人Peters异常(PA)患者的临床特征,研究Peters异常患者PITX2及PAX6基因变异情况。方法:选取2016/2019年在常州市第二人民医院及第三人民医院眼科就诊的15例Peters异常患者,并收集详细的相关临床资料。征得患者及其家系成员的同意后抽血制备基因组DNA,用聚合酶链反应(PCR)对致病基因PITX2及PAX6的编码区及其临接内含子进行扩增后,直接测序筛查中国人群Peters异常患者PITX2及PAX6基因变异,异源双链-单链构象多态性分析(HA-SSCP)的方法对突变患者及其家系成员及80例正常对照进行验证;分析比较国内已报道的Peters异常患者PITX2及PAX6基因突变并研究其相关表型。结果:Peters异常患者15例PITX2基因突变筛查结果发现了1种新PITX2的突变c.296delG(P.R99fsx56),导致该基因的功能异常,分析突变患者临床特征,该患者右眼诊断为Axenfeld-Rieger综合征(ARS),左眼诊断为Peters异常。而家系成员中该患者父母及无亲缘关系的正常对照者均未发现相同突变,故此突变为新生突变。PAX6基因突变筛查未能发现突变。结论:PA患者15例中检测到1个新PITX2基因突变,丰富了PITX2基因突变频谱,进一步明确了PA合并ARS眼病的临床特点,为该种少见眼病的临床诊断和发病原因提供了依据。

Root stoichiometric dynamics and homeostasis of invasive species Phyllostachys edulis and native species Cunninghamia lanceolata in a subtropical forest in China

The community species abundance and diversity declined with bamboo invasion had been widely reported worldwide.However,the physiological strategies used during root competition between native species and invasive bamboo are poorly understood.To clarify the mechanisms underlying such strategies,the stoichiometric dynamics and homeostasis of nitrogen,phosphorus,organic carbon in root orders of Phyllostachys edulis(I du[=Ⅰ-Pe,years 1 and 2];Ⅱdu[=Ⅱ-Pe,years 3 and 4]),Cunninghamia lanceolata in transition and pure forests were analyzed.With increasing intensity of bamboo invasion,N,P,and C content of C.lanceolata root orders declined,N and P content in P.edulis rhizome orders declined,while C increased,the stoichiometric ratios in mixed forest interface mainly increased,and the stoichiometric differences within native and invasive species root orders narrowed.Meanwhile,the stoichiometric homeostasis index(H)of elements in the same root order and even the same elements in different root orders were not consistent.H of most root orders(except some HP)was greater than 4,the H ranked order wasⅠ-Pe>Cl>Ⅱ-Pe in mixed interfaces,and the N:P ratio of most species root orders was greater than 16,despite being affected by invasion.Our research concluded that the bamboo invasion narrows stoichiometric differences within root orders,and the juvenile bamboo rhizome has a stronger capacity for homeostatic regulation than in adult bamboo and C.lanceolata,which is a key determinant of bamboo invasion success.

Effects of sodium valproate combined with levetiracetam in treatment of children epilepsy and its influences on serum S-100βand high mobility group box-1

Objective:To explore the effects of sodium valproate combined with levetiracetam in the treatment of children epilepsy,and its influences on serum S-100βand high mobility group box-1(HMGB-1)in children with epilepsy.Methods:A total of 160 children who were diagnosed as epilepsy in Baogang Hospital of Inner Mongolia from July 2016 to October 2018 were selected as research objects.They were randomly divided into the study group(n=80)and the control group(n=80)by the random number table method,i.e.,they were treated with sodium valproate combined with levetiracetam and sodium valproate alone,respectively.After 16 weeks of treatment,the effective rates of epileptic seizure treatment and the improvement of epileptiform discharge were evaluated,and chi-square test was used for statistical comparison.The related indicators,including serum tumor necrosis factor-(TNF-α),hypersensitive C-reactive protein(hs-CRP),homocysteine(Hcy),haematocrit(HCT),erythrocyte sedimentation rate(ESR),serum S-100βand HMGB-1,were measured before and after treatment.Paired t-test was used for the comparison in the above indicators within a group before and after treatment;group t-test was used for the comparison between two groups.Chi-square test was used for the comparison in the rate of adverse reactions during treatment between two groups.The study was approved by Ethics Committee of Baogang Hospital(Approval No.:BG201606073),and all children’s guardians were required to sign informed consent forms for clinical study.There were no statistically significant differences between two groups in general clinical data(p>0.05),such as sex constituent ratio,age,the course of disease,the frequency of epileptic seizure per year before treatment,the incidence of epileptiform discharge before treatment and the constituent ratio of types of epileptic seizure,etc.Results:1)After treatment,the effective rates of epileptic seizure treatment and the improvement of epileptiform discharge in the study group were 92.5%(74/80)and 85.0%(68/80)respectively,which were both significantly higher than those in the control group[68.8%(55/80)and 58.8%(47/80)],and the differences were statistically significant(Х^(2)=14.444,13.635;p<0.001).2)In the study group,the levels of serum TNF-α,hs-CRP and Hcy,as well as HCT and ESR after treatment were(53.1±14.0)pg/ml,(5.0±2.5)mg/L,(12.5±3.1)μmol/L,(38.1±5.1)%and(3.0±0.5)mm/h respectively,which were all significantly lower than those[(107.9±17.8)pg/ml,(10.1±2.5)mg/L,(42.2±5.8)μmol/L,(45.3±4.5)%and(5.2±0.6)mm/h]before treatment,and all the differences were statistically significant(t=21.644,12.902,40.393,9.468,25.194;p<0.001).In the control group,the levels of serum TNF-α,hs-CRP and Hcy,as well as HCT and ESR after treatment were(60.6±17.8)pg/ml,(8.2±2.2)mg/L,(15.2±3.1)μmol/L,(40.2±3.4)%and(4.5±0.6)mm/h respectively,which were all significantly lower than those[(112.4±14.3)pg/ml,(9.3±3.8)mg/L,(41.1±2.8)μmol/L,(44.6±5.5)%and(5.4±0.8)mm/h]before treatment,and all the differences were statistically significant(t=20.292,2.241,55.456,3.320,8.050;p<0.05).After treatment,the above indicators in the study group were all significantly lower than those in the control group,and all the differences were statistically significant(t=2.962,8.595,5.508,3.064,17.178;p<0.05).3)In the study group,the levels of serum S-100βand HMGB-1 after treatment were(0.65±0.38)μg/L and(5.3±2.4)μg/L respectively,which were significantly lower than those[(0.91±0.32)μg/L and(8.1±2.0)μg/L]before treatment,and the differences were statistically significant(t=4.681,8.020;p<0.001).In the control group,the levels of serum S-100βand HMGB-1 after treatment were(0.78±0.27)μg/L and(6.4±2.2)μg/L respectively,which were significantly lower than those[(0.88±0.25)μg/L and(7.9±1.7)μg/L]before treatment,and the differences were statistically significant(t=2.431,p=.016;t=4.826,p<0.001).After treatment,the levels of serum S-100βand HMGB-1 in the study group were significantly lower than those in the control group,and the differences were statistically significant(t=2.495,p=.014;t=2.840,p=.005).4)There was no significant difference between two groups in the rate of adverse reactions,such as nausea,vomiting,poor appetite,dizziness,drowsiness,hepatic and renal injury during treatment(p>0.05).Conclusions:The efficacy of sodium valproate combined with levetiracetam is obviously better than that of sodium valproate alone in the treatment of children epilepsy.The children patients’serum S-100βand HMGB-1 are more significantly reduced,resulting in a lower rate of adverse reactions,which has a certain clinical value.

Pilot test of polymer microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants under harsh conditions in a sandstone reservoir

The first pilot test of polyacrylamide microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants(Sa/c)was carried out for a high-temperature,high-salinity,and highhardness sandstone reservoir to demonstrate the potential of this novel technique to improve oil recovery.A critical micelle concentration(CMC)of 4.82 mg/L,an ultralow interfacial tension(IFT)of 8104 mN/m,and a high oil solubilization of 22 were obtained.Static and dynamic adsorptions of Sa/c on natural core containing 15 wt%clay were reduced to about 2.20 and 0.30 mg/g-core,respectively,with the addition of adsorption inhibitor(AI).Since June 2014,the pilot test of PMAS was carried out in a Sinopec reservoir with a temperature of 87C,a salinity of 260,393 mg/L,and a hardness of 6,401 mg/L.Twelve cycles of alternative injection of 0.0125 PV Sa/c with a concentration of 0.1%and 0.0125 PV polyacrylamide microsphere with a concentration of 0.2%were conducted at an injection rate of 0.1 PV/yr,for a total of 0.3 PV chemical injection.As a result,the net daily oil production increased from 0 t to 6.5 t,and the water cut decreased from 96.3%to 93.8%,leading to an ultimate improved oil recovery of 6.3%original oil-in-place.