P-Δ effect on inelastic displacement ratio spectra for inelastic structures

For the evaluation of structures with known ductility demands,the constant-ductility displacement ratio spectra(CDDRS) are particularly useful for providing inelastic displacement ratios to estimate maximum lateral inelastic displacement demands from maximum elastic displacement demands.The CDDRS are computed for single-degree-of-freedom systems(SDOF) by considering or ignoring P-Δ effect for different ductility levels when subjected to 344 earthquake ground motions recorded in four site classes.The modified expressions of CDDRS for P-Δ effect are proposed.It is concluded that the P-Δ effect on CDDRS is significant,and the effect increases with the increase of ductility level.In the long-period region,the CDDRS ignoring P-Δ effect almost conforms to the equal-displacement rule.But in the case of higher ductility level,the CDDRS considering P-Δ effect are much higher than 1.0,which do not conform to the equal-displacement rule.

Static and dynamic inelastic P-Δ effect for seismic design

Seismic influence of P-Δ effect is the subject of this study.First,it is pointed out that the elastic static amplification factor shall be isolated in formulating the dynamic inelastic second order effect.An amplification factor for the static inelastic P-Δ effect is derived.Seismic force reduction factors(SFRF)for given ductility and stability coefficients are computed for one-story,one-span frames.The P-Δ amplification factors for seismic base shears are obtained by dividing SFRFs with and without P-Δ effect.Both P-Δ amplification factors and SFRFs are presented separately with two kinds of period abscissas.The P-Δ amplification factors are dependent on periods with the maximum occurring at about 0.75 s for site type C and approach to the static inelastic counterpart at long periods.Post-yield stiffness cannot fully counteract the adverse impact of the P-Δ effect.Formulas for seismic P-Δ amplification factors are proposed and compared to results of others.Collapse capacity spectra(CCS)are reviewed and their application in codes discussed.Available CCSs are compared with SFRFs with finite ductility computed for two ensembles of seismic records.A comparison reveals that the SFRFs are affected by seismic records,and available CCSs do not always provide upper limits for the SFRFs when stability coefficients are greater than 0.1 for frame models.

Experimental investigation on the permeability of gap-graded soil due to horizontal suffusion considering boundary effect

The boundary condition is a crucial factor affecting the permeability variation due to suffusion.An experimental investigation on the permeability of gap-graded soil due to horizontal suffusion considering the boundary effect is conducted,where the hydraulic head difference(DH)varies,and the boundary includes non-loss and soil-loss conditions.Soil samples are filled into seven soil storerooms connected in turn.After evaluation,the variation in content of fine sand(ΔR_(f))and the hydraulic conductivity of soils in each storeroom(C_(i))are analyzed.In the non-loss test,the soil sample filling area is divided into runoff,transited,and accumulated areas according to the negative or positive ΔR_(f) values.ΔR_(f) increases from negative to positive along the seepage path,and Ci decreases from runoff area to transited area and then rebounds in accumulated area.In the soil-loss test,all soil sample filling areas belong to the runoff area,where the gentle-loss,strengthened-loss,and alleviated-loss parts are further divided.ΔR_(f) decreases from the gentle-loss part to the strengthened-loss part and then rebounds in the alleviated-loss part,and C_(i) increases and then decreases along the seepage path.The relationship between ΔR_(f) and Ci is different with the boundary condition.Ci exponentially decreases with ΔR_(f) in the non-loss test and increases with ΔR_(f) generally in the soil-loss test.

Cost-Effective Method of Gene Synthesis by Sequencing from Microchip-Derived Oligos for Droplet Cloning

Gene synthesis has provided important contributions in various fields including genomics and medicine. Current genes are 7 - 30 cents depending on the assembly and sequencing methods performed. Demand for gene synthesis has been increasing for the past few decades, yet available methods remain expensive. A solution to this problem involves microchip-derived oligonucleotides (oligos), an oligo pool with a substantial number of oligo fragments. Microchips have been proposed as a tool for gene synthesis, but this approach has been criticized for its high error rate during sequencing. This study tests a possible cost-effective method for gene synthesis utilizing fragment assembly and golden gate assembly, which can be employed for quicker manufacturing and efficient execution of genes in the near future. The droplet method was tested in two trials to determine the viability of the method through the accuracy of the oligos sequenced. A preliminary research experiment was performed to determine the efficacy of oligo lengths ranging from two to four overlapping oligos through Gibson assembly. Of the three oligo lengths tested, only two fragment oligos were correctly sequenced. Two fragment oligos were used for the second experiment, which determined the efficacy of the droplet method in reducing gene synthesis cost and speed. The first trial utilized a high-fidelity polymerase and resulted in 3% correctly sequenced oligos, so the second trial utilized a non-high-fidelity polymerase, resulting in 8% correctly sequenced oligos. After calculating, the cost of gene synthesis lowers down to 0.8 cents/base. The final calculated cost of 0.8 cents/base is significantly cheaper than other manufacturing costs of 7 - 30 cents/base. Reducing the cost of gene synthesis provides new insight into the cost-effectiveness of present technologies and protocols and has the potential to benefit the fields of bioengineering and gene therapy.

基于P-犹豫模糊集与VIKOR的绿色产品设计多属性决策方法

针对绿色产品设计属性不确定及其关联关系的复杂性问题,提出一种基于P-犹豫模糊集与多准则妥协解排序(VIKOR)法的绿色产品设计多属性决策方法。利用Pythagorean犹豫模糊数度量产品属性及其特征值得到专家初始权重;考虑绿色设计决策者及属性关联,运用λ-模糊测度、Shapley值和交叉熵得到决策者及属性关联权重;以综合最大化整体效用和最小化个体遗憾为目标,基于VIKOR法对绿色产品设计方案进行排序选择;最后通过实例分析验证方法的合理性和有效性。研究结果显示,该方法既可以综合绿色设计决策者心理,有效区分不同绿色设计方案之间的差别,又可以描述绿色设计决策者和属性间的关联关系,为绿色产品设计多属性决策提供了一种可行的方法。

血清HMGA2、P-gp与老年进展性脑梗死患者预后相关研究

目的探讨血清高迁移率族蛋白A2(HMGA2)、P-糖蛋白(P-gp)在老年进展性脑梗死患者中的表达水平及其与预后的关系。方法收集2020年2月—2023年2月大连市中心医院神经内科收治老年进展性脑梗死患者67例为进展组,老年非进展性脑梗死患者79例为非进展组;进展组根据治疗后3个月神经功能恢复情况分为预后良好亚组(n=39,mRS评分0~2分)和预后不良亚组(n=28,mRS评分3~6分)。采用酶联免疫吸附法检测血清HMGA2、P-gp水平,Pearson积矩相关分析血清HMGA2、P-gp与NIHSS评分的关系,Logistic回归分析进展性脑梗死患者预后不良的影响因素,受试者工作特征曲线(ROC)评估血清HMGA2、P-gp对预后不良的预测价值。结果进展组血清HMGA2、P-gp水平及NIHSS评分高于非进展组(t/P=13.672/<0.001,8.095/<0.001,8.226/<0.001)。进展性脑梗死患者血清HMGA2、P-gp与NIHSS评分均呈正相关(r/P=0.732/<0.001、0.708/<0.001);预后不良亚组患者年龄大于预后良好亚组,血清HMGA2、P-gp水平及NIHSS评分高于预后良好亚组(t/P=5.092/<0.001、5.103/<0.001、4.449/<0.001、2.357/0.021)。多因素Logistic回归结果显示,高龄和血清HMGA2、P-gp水平及NIHSS评分升高是进展性脑梗死患者预后不良独立危险因素[OR(95%CI)=1.429(1.093~1.869),1.288(1.082~1.533),1.586(1.161~2.165),1.483(1.120~1.963)];血清HMGA2、P-gp及二者联合预测进展性脑梗死患者预后不良的AUC分别为0.738、0.740、0.895,二者联合优于各自单独预测效能(Z/P=2.031/0.002、2.006/0.003)。结论血清HMGA2、P-gp在老年进展性脑梗死患者中异常升高,并与病情严重程度以及预后不良有关,早期联合检测两项指标可预测患者预后不良风险发生。

NVP-BEZ235逆转伯基特淋巴瘤RAJI细胞阿霉素耐药的研究

目的:研究NVP-BEZ23对耐阿霉素细胞株RAJI/DOX的逆转耐药作用。方法:利用浓度梯度法诱导耐阿霉素细胞株RAJI/DOX;Western blot测定各组细胞Pgp、p-AKT、p-mTOR蛋白水平;MTT法检测细胞抑制率,SPSS软件测定IC50。结果:成功诱导出耐阿霉素细胞株RAJI/DOX。耐阿霉素细胞株RAJI/DOX中Pgp、p-AKT、p-mTOR蛋白水平高于亲本细胞RAJI。NVP-BEZ235可引起耐阿霉素细胞株RAJI/DOX中p-AKT、p-mTOR蛋白水平下降。NVP-BEZ235能够抑制耐阿霉素细胞株RAJI/DOX增殖,与阿霉素具有协同作用。结论:PI3K/AKT/mTOR通道在耐阿霉素伯基特淋巴瘤细胞中进一步活化;NVP-BEZ235通过抑制PI3K/AKT/mTOR信号通道活化,能够与阿霉素协同抑制伯基特淋巴瘤耐药细胞,逆转伯基特淋巴瘤耐药细胞对阿霉素的耐药性。

基于改进p-有效点法的多风电场共享储能联合参与一次调频的容量优化

以大规模多风电场接入电力系统的一次调频备用容量为研究对象,首先通过引入风电出力预测误差的概率分布描述系统的不确定性因素,考虑风储一次调频备用总成本最小为目标;然后建立基于机会约束规划的多风电场联合共享储能参与一次调频的容量优化模型;最后提出基于快速傅里叶变换快速求解联合变量概率分布的改进p-有效点法通过数学解析将机会约束规划从形式上转化为确定性规划,再通过Yalmip调用Cplex实现模型的快速求解。算例结果表明,所提模型和方法可有效提高风储调频效果和收益,且具有更高的求解效率。

240 nm AlGaN-based deep ultraviolet micro-LEDs:size effect versus edge effect

240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge effects.Here,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μm.Thereinto,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light extraction.Most notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector design.However,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized ones.The underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further shrinking.Moreover,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa edge.These findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs.

Evaluation of the intracellular lipid-lowering effect of polyphenols extract from highland barley in HepG2 cells

Active ingredients from highland barley have received considerable attention as natural products for developing treatments and dietary supplements against obesity.In practical application,the research of food combinations is more significant than a specific food component.This study investigated the lipid-lowering effect of highland barley polyphenols via lipase assay in vitro and HepG2 cells induced by oleic acid(OA).Five indexes,triglyceride(TG),total cholesterol(T-CHO),low density lipoprotein-cholesterol(LDL-C),aspartate aminotransferase(AST),and alanine aminotransferase(ALT),were used to evaluate the lipidlowering effect of highland barley extract.We also preliminary studied the lipid-lowering mechanism by Realtime fluorescent quantitative polymerase chain reaction(q PCR).The results indicated that highland barley extract contains many components with lipid-lowering effects,such as hyperoside and scoparone.In vitro,the lipase assay showed an 18.4%lipase inhibition rate when the additive contents of highland barley extract were 100μg/m L.The intracellular lipid-lowering effect of highland barley extract was examined using 0.25 mmol/L OA-induced HepG2 cells.The results showed that intracellular TG,LDL-C,and T-CHO content decreased by 34.4%,51.2%,and 18.4%,respectively.ALT and AST decreased by 51.6%and 20.7%compared with the untreated hyperlipidemic HepG2 cells.q PCR results showed that highland barley polyphenols could up-regulation the expression of lipid metabolism-related genes such as PPARγand Fabp4.

Engineering Strategies for Suppressing the Shuttle Effect in Lithium–Sulfur Batteries

Lithium–sulfur(Li–S)batteries are supposed to be one of the most potential next-generation batteries owing to their high theoretical capacity and low cost.Nevertheless,the shuttle effect of firm multi-step two-electron reaction between sulfur and lithium in liquid electrolyte makes the capacity much smaller than the theoretical value.Many methods were proposed for inhibiting the shuttle effect of polysulfide,improving corresponding redox kinetics and enhancing the integral performance of Li–S batteries.Here,we will comprehensively and systematically summarize the strategies for inhibiting the shuttle effect from all components of Li–S batteries.First,the electrochemical principles/mechanism and origin of the shuttle effect are described in detail.Moreover,the efficient strategies,including boosting the sulfur conversion rate of sulfur,confining sulfur or lithium polysulfides(LPS)within cathode host,confining LPS in the shield layer,and preventing LPS from contacting the anode,will be discussed to suppress the shuttle effect.Then,recent advances in inhibition of shuttle effect in cathode,electrolyte,separator,and anode with the aforementioned strategies have been summarized to direct the further design of efficient materials for Li–S batteries.Finally,we present prospects for inhibition of the LPS shuttle and potential development directions in Li–S batteries.

亚油酸诱导植物乳杆菌p-8产生共轭亚油酸的蛋白组和类组蛋白乙酰化分析

研究亚油酸(linoleic acid,LA)诱导下植物乳杆菌(Lactobacillus plantarum)p-8的蛋白组和类组蛋白乙酰化水平差异,探究共轭亚油酸(conjugated linoleic acid,CLA)产生的机制。结果表明,LA的最佳诱导质量浓度为1 mg/mL,在此质量浓度条件下,蛋白质组学分析发现,烯酰-酰基载体蛋白还原酶、酰基载体蛋白等脂肪酸合成的关键蛋白因子下调,脂肪酸合成下调,乙酰基转移酶水平上调。Western blot结合体外添加NaAc实验表明,乙酰辅酶A含量增加导致类组蛋白乙酰化水平提升。实时聚合酶链式反应检测显示,添加LA和NaAc使CLA相关酶、转录调控因子和Sigma因子的mRNA表达升高,CLA含量也提高。相关性分析得出,乙酰辅酶A与LA水合酶转录水平和CLA含量之间呈显著正相关,揭示乙酰辅酶A和乙酰基转移酶含量上调导致类组蛋白乙酰化加强而上调CLA合成。结果为分子改良或科学调控乳酸菌以提高CLA转化率奠定了基础。

具p-双调和算子的非局部椭圆方程Navier边值问题的广义解

利用变分方法和相应的临界点定理研究一类具有p-双调和算子的非局部椭圆方程Navier边值问题,在非线性项满足超线性条件时,得到了两个非平凡广义解的存在性定理.

A method to interpret fracture aperture of rock slope using adaptive shape and unmanned aerial vehicle multi-angle nap-of-the-object photogrammetry

The aperture of natural rock fractures significantly affects the deformation and strength properties of rock masses,as well as the hydrodynamic properties of fractured rock masses.The conventional measurement methods are inadequate for collecting data on high-steep rock slopes in complex mountainous regions.This study establishes a high-resolution three-dimensional model of a rock slope using unmanned aerial vehicle(UAV)multi-angle nap-of-the-object photogrammetry to obtain edge feature points of fractures.Fracture opening morphology is characterized using coordinate projection and transformation.Fracture central axis is determined using vertical measuring lines,allowing for the interpretation of aperture of adaptive fracture shape.The feasibility and reliability of the new method are verified at a construction site of a railway in southeast Tibet,China.The study shows that the fracture aperture has a significant interval effect and size effect.The optimal sampling length for fractures is approximately 0.5e1 m,and the optimal aperture interpretation results can be achieved when the measuring line spacing is 1%of the sampling length.Tensile fractures in the study area generally have larger apertures than shear fractures,and their tendency to increase with slope height is also greater than that of shear fractures.The aperture of tensile fractures is generally positively correlated with their trace length,while the correlation between the aperture of shear fractures and their trace length appears to be weak.Fractures of different orientations exhibit certain differences in their distribution of aperture,but generally follow the forms of normal,log-normal,and gamma distributions.This study provides essential data support for rock and slope stability evaluation,which is of significant practical importance.

健脾化瘀解毒法对结肠癌裸鼠模型癌及癌旁组织中AKT、mTOR、p-4EBP1表达的影响研究

目的研究健脾化瘀解毒法对结肠癌原位种植瘤癌及癌旁组织中蛋白激酶B(AKT)、哺乳动物雷帕霉素靶蛋白(mTOR)、磷酸化真核细胞起始因子4E结合蛋白1(p-4EBP1)表达的影响。方法建立裸鼠结肠癌模型,随机分为空白组、模型组、健脾益气组、化瘀解毒组、健脾化瘀解毒组、雷帕霉素组及5-氟尿嘧啶组,每组5只。干预各组4周后,检测各组癌组织与癌旁组织中AKT、mTOR、p-4EBP1的表达水平。结果与空白组比较,模型组癌组织与癌旁组织中AKT1、mTOR、p-4EBP1的表达均上调,差异有显著性(P<0.05),且AKT、mTOR、p-4EBP1的表达水平均为癌组织>癌旁组织>正常肠黏膜组织。与模型组比较,健脾化瘀解毒法能在一定程度上抑制结肠癌癌组织及癌旁组织中AKT、mTOR、p-4EBP1的表达水平,差异有统计学意义(P<0.05);健脾益气法、化瘀解毒法均能下调癌组织与癌旁组织中AKT、mTOR、p-4EBP1蛋白,但其降低水平不如健脾化瘀解毒法。结论健脾化瘀解毒法能够降低AKT、mTOR、p-4EBP1蛋白的表达,健脾益气法与化瘀解毒法协同增效,以获得最佳疗效。

Experimental study on the effect of water absorption level on rockburst occurrence of sandstone

To investigate the mechanism of rockburst prevention by spraying water onto the surrounding rocks,15 experiments are performed considering different water absorption levels on a single face.High-speed photography and acoustic emission(AE)system are used to monitor the rockburst process.The effect of water on sandstone rockburst and the prevention mechanism of water on sandstone rockburst are analyzed from the perspective of energy and failure mode.The results show that the higher the ab-sorption degree,the lower the intensity of the rockburst after absorbing water on single side of sand-stone.This is reflected in the fact that with the increase in the water absorption level,the ejection velocity of rockburst fragments is smaller,the depth of the rockburst pit is shallower,and the AE energy is smaller.Under the water absorption level of 100%,the magnitude of rockburst intensity changes from medium to slight.The prevention mechanism of water on sandstone rockburst is that water reduces the capacity of sandstone to store strain energy and accelerates the expansion of shear cracks,which is not conducive to the occurrence of plate cracking before rockburst,and destroys the conditions for rockburst incubation.

温度和湿度对P-CNT自感知混凝土压敏性的影响

为研究温度与湿度对自感知混凝土(SSC)感知性能的影响,通过低温等离子体改性处理技术对碳纳米管(CNT)进行官能团嫁接,使其在水性体系下获得较好的分散性,并将改性后的CNT(P-CNT)加入混凝土中制备P-CNT/SSC传感器,通过改变含水率与温度条件研究P-CNT/SSC传感器的极化效应与循环加载下的自感知性能。试验结果表明:过高或过低的含水率均不利于SSC的感知性能,其中变化最为明显的是饱水状态下的P-CNT/SSC传感器,其应力敏感系数下降89.8%,并且压敏曲线极不稳定;在变温试验中,P-CNT/SSC传感器的电阻率与温度之间呈现负相关性,高温和低温下的应力敏感系数相较于常温组试件,分别下降了约35.66%和44.53%,并且压敏曲线整体出现了上移或下滑的趋势;P-CNT/SSC传感器在工程应用中的最佳测试环境为常温、自然含水率。

High responsivity photodetectors based on graphene/WSe_(2) heterostructure by photogating effect

Graphene, with its zero-bandgap electronic structure, is a highly promising ultra-broadband light absorbing material.However, the performance of graphene-based photodetectors is limited by weak absorption efficiency and rapid recombination of photoexcited carriers, leading to poor photodetection performance. Here, inspired by the photogating effect, we demonstrated a highly sensitive photodetector based on graphene/WSe_(2) vertical heterostructure where the WSe_(2) layer acts as both the light absorption layer and the localized grating layer. The graphene conductive channel is induced to produce more carriers by capacitive coupling. Due to the strong light absorption and high external quantum efficiency of multilayer WSe_(2), as well as the high carrier mobility of graphene, a high photocurrent is generated in the vertical heterostructure. As a result, the photodetector exhibits ultra-high responsivity of 3.85×10~4A/W and external quantum efficiency of 1.3 × 10~7%.This finding demonstrates that photogating structures can effectively enhance the sensitivity of graphene-based photodetectors and may have great potential applications in future optoelectronic devices.

Cumulative effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease in China

BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD.

基于AHP-FCE的职业农民学历教育教学效果评价研究

开展新型职业农民学历教育教学效果评价,为职业院校教学质量的评估提供切实可行的科学依据。该文构建教学效果、教学满意度、教学忠诚度和生产状况4个一级指标的新型职业农民学历教育教学效果评价体系,并采用多层模糊综合评价模型(AHP-FCE)进行实证检验。