Causal associations between intermediate very-low-density lipoprotein cholesterol-to-total lipids ratio and peptic ulcer:A bidirectional Mendelian randomization study

BACKGROUND Previous epidemiologic investigations have consistently demonstrated a strong association between the ratio of cholesterol to total lipids in medium very-lowdensity lipoprotein(VLDL)and the occurrence of peptic ulcers(PU).However,the precise causal relationship between these factors remains ambiguous.Consequently,this study aims to elucidate the potential correlation between the ratio of cholesterol to total lipids in medium VLDL and the incidence of peptic ulcer.AIM To investigate the ratio of cholesterol to total lipids in medium very-low-density lipoprotein(VLDL)association with PU via genetic methods,guiding future clinical research.METHODS Genome-wide association study(GWAS)datasets for the ratio of cholesterol to total lipids in intermediate VLDL and peptic ulcer were retrieved from the IEU OpenGWAS project(https://gwas.mrcieu.ac.uk).For the forward Mendelian randomization(MR)analysis,72 single nucleotide polymorphisms(SNPs)were identified as instrumental variables.These SNPs were selected based on their association with the ratio of cholesterol to total lipids in intermediate VLDL,with peptic ulcer as the outcome variable.Conversely,for the inverse MR analysis,no SNPs were identified with peptic ulcer as the exposure variable and the ratio of cholesterol to total lipids in intermediate VLDL as the outcome.All MR analyses utilized inverse variance weighted(IVW)as the primary analytical method.Additionally,weighted median and MR-Egger methods were employed as supplementary analytical approaches to assess causal effects.Egger regression was used as a supplementary method to evaluate potential directional pleiotropy.Heterogeneity and multiplicity tests were conducted using the leave-one-out method to evaluate result stability and mitigate biases associated with multiple testing.RESULTS The genetically predicted ratio of cholesterol to total lipids in medium VLDL was significantly associated with an elevated risk of peptic ulcer(IVW:OR=2.557,95%CI=1.274-5.132,P=0.008).However,no causal association of peptic ulcer with the ratio of cholesterol to total lipids in medium VLDL was observed in the inverse Mendelian randomization analysis.CONCLUSION In conclusion,our study reveals a significant association between the ratio of cholesterol to total lipids in medium VLDL and an elevated risk of peptic ulcers.However,further validation through laboratory investigations and larger-scale studies is warranted to strengthen the evidence and confirm the causal relationship between these factors.

Evaluation of diagnostic ratios of medium and serious weathered oils from five different oil sources

Laboratory experiments were conducted to simulate oil weathering process, a medium to long term weathering process for 210-d, using samples collected from five different oil resources. Based on relative deviation and repeatability limit analysis about indexes of these samples, the results show there had been significant changes in diagnostic ratios among the initial and weathered samples of different oils during this process. Changes of selected n-alkane diagnostic ratios of all oil samples displayed more obviously than diagnostic ratios of terpanes,steranes and PAHs in this process. Almost all selected diagnostic ratios of terpanes, steranes and PAHs can be efficiently used in tracking sources of hydrocarbon pollution, differentiating from the n-alkane diagnostic ratios.In these efficient diagnostic ratios, only four ratios maintained good stability in the weathering processes and are more suitable because their relative deviation（RSD） are lower than 5%.

烟叶打叶后大片率调控关键技术研究

为解决当前烟叶打叶后大片率过高的问题,提出了对打叶后烟片采用振筛机大片叶筛选、图像监控打辊机可控再打叶的技术处理方案。设计实现了烟片分选再处理装置,并通过实验研究了不同控制参数对再打叶后烟叶的影响。结果表明:(1)提高振筛机筛孔孔径有助于大片叶分离;(2)再处理打辊机框栏开口尺寸与形状相比提高转速对再打叶效果的影响更为显著,使用圆形50.8 mm框栏开口的打辊机可实现再打叶后大片率低于30%、中片率高于45%、含末率低于0.3%的水平;(3)提高打辊机转动频率和增加再处理大片叶分料比例有助于降低大片率,但均会导致中片率降低和烟末增加。实验表明打辊机转动频率和分料比例分别控制在40 Hz和50%左右时表现较好。

基于VTI介质的页岩储层地应力预测方法及应用研究

地应力对页岩气的采集及储层改造具有重要的指导作用,准确的地应力预测可以为优化压裂改造提供依据。页岩储层纵向上存在各向异性特征,为提高页岩储层地应力预测精度,将页岩储层等效为横向各向同性介质(VTI)模型,结合等效模型刚度矩阵参数、弹性系数及结构应变系数,开展页岩储层地应力场及应力差异比的三维模拟,预测水平主应力值、应力方向及应力差异比;并将地应力与储层裂缝、含气量相关参数相结合,分析三者之间存在的联系,并将该方法应用于试验工区龙马溪组页岩储层的地应力预测中。结果表明,基于VTI介质模型的地应力预测结果相较于基于各向同性模型的精度更高,工区应力差异比整体较大,进行压裂改造较困难,压裂不易形成较好的裂缝网络;随水平最大主应力的增大,曲率值减小,含气量存在减小的趋势。

Mirador铜矿一段磨矿球磨机介质配比优化研究

针对Mirador铜矿Ф7.9 m×13.6 m球磨机装补球制度不合理、磨矿产品粒度组成不合理等问题,对初装球介质配比进行了计算。确定初装球方案为Ф80 mm、Ф60 mm、Ф50 mm、Ф40 mm、Ф30 mm钢球质量为15∶20∶25∶20∶20,对推荐初装球与原初装球进行磨矿对比试验,推荐初装球径配比适宜且级配合理,磨矿产品-0.074 mm级别产率比现场原初装球配比提高了4.11个百分点,0.074~0.010 mm中间粒级产率提高了2.05个百分点,且待磨+0.20 mm产率降低了6.24个百分点,优化效果明显。补加球对比试验结果表明,与补加单一钢球相比,补加钢球采用Ф80 mm、Ф60 mm、Ф50 mm、Ф40 mm质量比为25∶35∶20∶20时,获得的磨矿产品-0.074 mm级别产率提高了6.05个百分点,中间易选粒级0.074~0.010 mm产率提高了3.14个百分点,+0.20 mm粒级降低了8.87个百分点。试验结果对改善一段磨矿产品粒度组成,减少混合浮选尾矿中粗粒级含铜,提高铜回收率具有重要意义。

战略性新兴企业ESG表现、中长期信贷与企业绩效——基于杠杆率的门槛效应

基于2019-2021年A股上市战略性新兴企业面板数据,对战略性新兴企业ESG表现、企业中长期信贷与企业绩效之间基于杠杆率的门槛效应的关系进行了分析。研究表明:①当战略性新兴企业ESG表现越好,其在追求利润的同时越注重环境社会责任担当,能够长期可持续性发展可能性越高,从而企业能从信贷类金融机构获取更多的中长期信贷越多,缓解战略性新兴企业融资困境;②战略性新兴企业获取中长期信贷后更能对周期较长的研发投产创造产能绩效,进一步提高企业高质量创新发展能力,同时中长期信贷过多会导致企业杠杆率过高,企业还债能力不足的情况下会导致企业绩效持续下降。进而找寻到一个适度杠杆阈值来约束企业杠杆率增减,使得企业在此参考杠杆阈值内将企业中长期信贷作用最大化,以此获得企业绩效最大化。

濒危植物华木莲叶片组织培养初探

华木莲是木兰科的珍贵濒危树种,具有重要的潜在应用价值。本研究采用华木莲叶片为实验材料,通过单因素实验,探究华木莲叶片诱导愈伤组织的最佳消毒时长、最适宜激素浓度配比及最佳培养基。结果表明:(1)以0.1%的升汞溶液(HgCl 2)作为消毒剂,消毒时长为8 min时,华木莲叶片诱导愈伤组织培养外植体污染率最低;(2)MS培养基为华木莲叶片组织培养的最佳基本培养基;(3)华木莲叶片诱导愈伤组织形成最适激素配比为MS+2.0 mg/L 6-BA+0.2 mg/L IBA。研究结果是对华木莲组织培养技术的经验总结,同时对华木莲的保护与利用有一定的实际意义。

圆钢管煤矸石混凝土中长柱轴压性能有限元分析

目的研究圆钢管煤矸石混凝土中长柱的轴压性能,找到各设计参数对试件轴压承载力的影响规律,提出轴压承载力计算式,推广钢-煤矸石混凝土组合结构。方法采用ABAQUS有限元分析软件建立圆钢管煤矸石混凝土中长柱轴压有限元模型,分析典型试件受力全过程的应力分布、荷载分配以及不同参数变化对其轴压承载力的影响。结果相同设计参数下,钢材屈服强度与含钢率是承载力的关键影响因素;而随煤矸石粗骨料取代率的增加,试件的承载力降低幅度未超过3.6%。结论掺入煤矸石粗骨料后的试件仍具有较高承载力,依据《钢管混凝土结构技术规范》(GB 50936—2014)中的方法对计算式进行修正后的误差在10%以内,适用于圆钢管煤矸石混凝土中长柱,能够满足实际需求。

砖混建筑废弃物再生碎砖混凝土耐久性研究

砖混建筑废弃物经过破碎筛选可以制成再生碎砖粗骨料,将其与水泥、河砂细骨料等主要原料混合,可以制备再生碎砖混凝土试件。为探究再生碎砖混凝土的耐久性,通过抗氯离子渗透性、干湿循环、冻融循环试验,分析不同水灰比以及再生碎砖粗骨料、粉煤灰、硅粉含量下混凝土试件的抗压强度、氯离子迁移系数以及质量损失率和动弹性模量的变化,并分析了混凝土试件在不同冻融介质中的质量损失率和动弹性模量的变化情况。结果表明:当碎砖粗骨料、粉煤灰、硅粉掺量分别为15%、16%、7%,水灰比为0.4时,再生碎砖混凝土试件的抗压强度、动弹性模量指标最大,抗氯离子渗透能力最优,质量损失率最小,耐久性最好;再生碎砖混凝土试件在水介质中的耐久性最大,在4%氯化钠溶液的耐久性最小,在4%硫酸钠溶液的耐久性居中。

层状介质背景下地-井方位激电异常分析与解释

为了更好地探究层状介质背景下井旁隐伏矿体的地-井方位激电异常特征,首先研究了地-井三维激电的有限元正演模拟算法,并编制了程序;然后构建三维地电模型并进行正演模拟,讨论层状介质背景下地-井方位激电异常,并分析其异常特征规律;最后通过比值法归一化压制层状介质背景,突出局部异常。理论和算例表明,比值法归一化处理是地-井方位激电观测中消除层状介质背景异常影响的有效方法。

城市商业银行在资本新规背景下对小微企业融资的策略研究

在《商业银行资本管理办法》(资本新规)的背景下,城市商业银行的前景充满了挑战与机遇。资本新规提高了商业银行的风险抵御能力,使其在复杂市场环境中运营更为稳健,但同时也对其业务运营效率提出了更高要求。为了更好地支持小微企业的融资与发展,城市商业银行必须调整融资策略,如增加对小微企业的信贷投放、优化审批流程以及提供更加灵活的融资方案。本文通过深入分析小微企业的融资现状和需求特点,以及明确城市商业银行所面临的问题和挑战,提出针对性的策略建议,旨在帮助城市商业银行更好地适应资本新规要求、满足小微企业融资需求、推动实体经济发展,为城市商业银行的发展提供指导和借鉴。

影响DAM中波发射机信噪比的因素分析及对策研究

主要研究了影响数字调幅(Digital Amplitude Modulation,DAM)中波发射机信噪比的主要因素和相应的对策。首先介绍了数字调幅广播的工作原理和DAM中波发射机信噪比(Signal-to-Noise Ratio,SNR)的基本概念,其次重点分析了影响DAM中波发射机信噪比的主要因素,最后针对性地提出了抑制其影响的措施,以期为改进DAM中波发射机性能提供参考。

小宽跨比山区中小跨径桥梁设计要点研究

随着我国基础设施建设的不断推进,山区中小跨径桥梁的设计和施工技术日臻完善。本文在前人研究的基础上,进一步探讨小宽跨比山区中小跨径桥梁设计要点,以期为山区桥梁设计提供更为详尽的参考。

中高灰炼焦煤生产高品质83焦的应用实践

为了降低配煤成本,云煤能源安宁分公司使用低价格的中高灰炼焦煤。由于配量过大,导致焦炭CSR严重下降,在总结经验和小焦炉试验的基础上,采用合适的配煤比,消化了库存的中高灰炼焦煤,焦炭CSR达到≥66.0%的要求。

Investigation of block foundations resting on soil-rock and rock-rock media under coupled vibrations

In the present study,the dynamic response of block foundations of different equivalent radius to mass（R;/m） ratios under coupled vibrations is investigated for various homogeneous and layered systems.The frequency-dependent stiffness and damping of foundation resting on homogeneous soils and rocks are determined using the half-space theory.The dynamic response characteristics of foundation resting on the layered system considering rock-rock combination are evaluated using finite element program with transmitting boundaries.Frequencies versus amplitude responses of block foundation are obtained for both translational and rotational motion.A new methodology is proposed for determination of dynamic response of block foundations resting on soil-rock and weathered rock-rock system in the form of equations and graphs.The variations of dimensionless natural frequency and dimensionless resonant amplitude with shear wave velocity ratio are investigated for different thicknesses of top soil/weathered rock layer.The dynamic behaviors of block foundations are also analyzed for different rock-rock systems by considering sandstone,shale and limestone underlain by basalt.The variations of stiffness,damping and amplitudes of block foundations with frequency are shown in this study for various rock—rock combinations.In the analysis,two resonant peaks are observed at two different frequencies for both translational and rotational motion.It is observed that the dimensionless resonant amplitudes decrease and natural frequencies increase with increase in shear wave velocity ratio.Finally,the parametric study is performed for block foundations with dimensions of 4 m × 3 m × 2 m and 8m×5m×2m by using generalized graphs.The variations of natural frequency and peak displacement amplitude are also studied for different top layer thicknesses and eccentric moments.

基于Weibull分布的不同冻融介质下再生骨料透水混凝土耐久性能研究

为探究不同环境下再生骨料透水混凝土(RPC)耐久性变化规律,以3种再生骨料替代率(0、30%、50%)和4种冻融介质(H 2O、3.5%NaCl、5%Na_(2)SO_(4)、3.5%NaCl+5%Na_(2)SO_(4))为变量进行冻融试验。定期测定RPC质量损失率和相对抗压强度损失率,对RPC取样并进行扫描电镜(SEM)分析,以冻融试验下RPC相对抗压强度损失率为依据,利用Weibull函数对RPC进行寿命预测。结果表明,同一环境下,RPC质量损失率和相对抗压强度损失率随着再生骨料替代率的增加而增加;同一再生骨料替代率下,3.5%NaCl、5%Na_(2)SO_(4)、3.5%NaCl+5%Na_(2)SO_(4)均加速RPC冻融破坏,3.5%NaCl+5%Na_(2)SO_(4)对RPC质量损失率和相对抗压强度损失率影响最严重。由SEM分析可知RPC内部孔隙和侵蚀产物数量均因循环次数和冻融介质的变化呈现明显的差异性,NaCl和Na_(2)SO_(4)对RPC侵蚀破坏起着相互促进的作用。由寿命预测结果可知,H 2O中RPC-0可靠度退化持续时间最长,即预测寿命最长,为4675 h左右,3.5%NaCl+5%Na_(2)SO_(4)溶液中RPC-50可靠度退化持续啥时间最短,为2200 h左右,表明NaCl和Na_(2)SO_(4)对RPC侵蚀作用较为严重。

Cohesion variation during instability evolution of disaster medium in mud inrush of mountain tunnel

Mud inrush in mountain tunnel is an independent geological hazard type different from water inrush,landslide and debris flow.The intrinsic factor of mud inrush is the instability failure of disaster medium.Its essence is that when the cohesion decreases gradually with the increase of void ratio to the point where the movement of soil particles cannot be restricted,soil particles and groundwater form slurry and gush out.Thus,accurate calculation of cohesion with variable void ratios is crucial for analyzing the reliability of disaster medium.In this study,the disaster medium was regarded as graded soil and a structural model was established wherein soil particles were simplified as cubes and the inter-particle pores were represented by the clearance between cubes.On the basis of the structure model of disaster medium,a function between the soil particle distance and void ratio was derived.Cohesion is equivalent to the resultant force between soil particles per unit area;thus,a cohesion function was derived in which the void ratio is the main variable.This function considers the influence of gradation characteristics on cohesion variation and is generally applicable to various types of disaster medium.A series of direct shear tests were carried out to determine the cohesion variation for different types of disaster medium with variable void ratios.By comparing the variation of cohesion obtained through direct shear tests with those deduced by the proposed cohesion function,we verified the validity and general applicability of the cohesion function.It is of great significance because the cohesion function can accurately predict the variation of cohesion by using the void ratio,and effectively evaluate the possibility of mud inrush according to the initial mechanical properties of disaster medium.

Unconventional Medium Effect in K^+ Scattering From ~6Li,^(12)C,^(28)Si and ^(40)Ca

The results of comprehensive microscopic optical model calculations are pres-ented for the K+ scattering from 6Li,12C,28Si and 40Ca at incident momenta 400-800MeV/c.The unconventional medium effect （i.e.the density-dependent correction forthe K+-nucleon scattering amplitude） is considered in two approaches.Both results arein agreement with recent experimental data.The influence of the correction on K+ scat-tering from different nuclei are discussed in detail and only a weak dependence of thein-medium nucleon“swelling”effects on the mass number of target nuclei is found ex-cept for very light loosely-bound nucleus.

Stress-strain analysis on AA7075 cylindrical parts during hot granule medium pressure forming

Hot granule medium pressure forming(HGMF) is a technology in which heat-resistant granules are used to replace liquids or gases in existing flexible-die forming technology as pressure-transfer medium. Considering the characteristic of granule medium that seals and loads easily, the technology provides a new method to realize the hot deep-drawing forming on high strength aluminum alloy sheet. Based on the pressure-transfer performance test of granule medium and the material performance test of AA7075-T6 sheet, plastic mechanics analysis is conducted for the areas, such as the flange area, force-transfer area and free deforming area, of cylindrical parts deep-drawn by HGMF technology, and the function relation of forming pressure is obtained under the condition of nonuniform distribution of internal pressure. The comparison between theoretical result and experimental data shows that larger deviation occurs in the middle and later period of forming process, and the maximum theoretical forming force is less than the experimental value by 24.6%. The variation tendency of the theoretical thickness curve is close to the practical situation, and the theoretical value basically agrees well with experimental value in the flange area and the top area of spherical cap which is in the free deforming area.

基于磨矿动力学某铜矿磨矿介质配比优化试验研究

针对云南某铜矿磨矿介质配比m(Φ80)∶m(Φ60)=50∶50与球磨机给矿力学性质及粒度不匹配,导致磨矿细度及中间易选粒级产率偏低等问题,基于磨矿动力学原理可得到磨矿介质推荐配比m(Φ70)∶m(Φ60)∶m(Φ50)∶m(Φ40)=15∶30∶10∶45。对比试验结果表明,推荐配比与现场配比相比,磨矿前期(4 min),+0.3 mm粒级物料产率提高1.01百分点,0.3~0.074 mm粒级产率降低7.88百分点;磨矿细度(-0.074 mm)在12 min时达到79.85%,且中间易选粒级与过粉碎粒级产率分别提高3.44、1.79百分点。最终推荐选厂选择基于磨矿动力学原理所得介质配比m(Φ70)∶m(Φ60)∶m(Φ50)∶m(Φ40)=15∶30∶10∶45。