Alkyl dimethyl betaine activates the low-temperature collection capacity of sodium oleate for scheelite

The impact of alkyl dimethyl betaine (ADB) on the collection capacity of sodium oleate (NaOl) at low temperatures was evaluated using flotation tests at various scales. The low-temperature synergistic mechanism of ADB and NaOl was explored by infrared spectroscopy, X-ray photoelectron spectroscopy, surface tension measurement, foam performance test, and flotation reagent size measurement.The flotation tests revealed that the collector mixed with octadecyl dimethyl betaine (ODB) and NaOl in a mass ratio of 4:96 exhibited the highest collection capacity. The combined collector could increase the scheelite recovery by 3.48% at low temperatures of 8–12℃. This is particularly relevant in the Luanchuan area, which has the largest scheelite concentrate output in China. The results confirmed that ODB enhanced the collection capability of NaOl by improving the dispersion and foaming performance. Betaine can be introduced as an additive to NaOl to improve the recovery of scheelite at low temperatures.

Engineering vascularized organotypic tissues via module assembly

Adequate vascularization is a critical determinant for the successful construction and clinical implementation of complex organotypic tissue models. Currently, low cell and vessel density and insufficient vascular maturation make vascularized organotypic tissue construction difficult,greatly limiting its use in tissue engineering and regenerative medicine. To address these limitations, recent studies have adopted pre-vascularized microtissue assembly for the rapid generation of functional tissue analogs with dense vascular networks and high cell density. In this article, we summarize the development of module assembly-based vascularized organotypic tissue construction and its application in tissue repair and regeneration, organ-scale tissue biomanufacturing, as well as advanced tissue modeling.

Psychiatric comorbidities in epilepsy:population co-occurrence,genetic correlations and causal effects

Background Psychiatric comorbidities are common in patients with epilepsy.Reasons for the co-occurrence of psychiatric conditions and epilepsy remain poorly understood.Aim We aimed to triangulate the relationship between epilepsy and psychiatric conditions to determine the extent and possible origins of these conditions.Methods Using nationwide Swedish health registries,we quantified the lifetime prevalence of psychiatric disorders in patients with epilepsy.We then used summarydata from genome-wide association studies to investigate whether the identified observational associations could be attributed to a shared underlying genetic aetiology using cross-trait linkage disequilibrium score regression.Finally,we assessed the potential bidirectional relationships using two-sample Mendelian randomisation.Results In a cohort of 7628495 individuals,we found that almost half of the 94435 individuals diagnosed with epilepsy were also diagnosed with a psychiatric condition in their lifetime(adjusted lifetime prevalence,44.09%;95%confidence interval(Cl)43.78%to 44.39%).We found evidence for a genetic correlation between epilepsy and some neurodevelopmental and psychiatric conditions.For example,we observed a genetic correlation between epilepsy and attention-deficit/hyperactivity disorder(r,=0.18,95%Cl 0.09 to 0.27,p<0.001)—a correlation that was more pronounced in focal epilepsy(r=0.23,95%CI 0.09 to 0.36,p<0.001).Findings from Mendelian randomisation using common genetic variants did not support bidirectional effects between epilepsy and neurodevelopmental or psychiatric conditions.Conclusions Psychiatric comorbidities are common in patients with epilepsy.Genetic correlations may partially explain some comorbidities;however,there is little evidence of a bidirectional relationship between the genetic liability of epilepsy and psychiatric conditions.These findings highlight the need to understand the role of environmental factors or rare genetic variations in the origins of psychiatric comorbidities in epilepsy.

Pyroelectric Plate with Magnetoelectric Effect

In dynamic problems the electric and magnetic fields are inseparable. At the same time, a multitude of electrostatic and magnetostatic effects permit mutually independent description. This separation appears to be possible and thermodynamically consistent when the bulk energy density depends only on the polarization density or, alternatively, on the magnetization density. However, when the bulk energy density depends simultaneously on the both densities, then, the electrostatic and magnetostatic effects should be studied together. There appear interesting cross-effects;among those are the change of the internal electrostatic field inside a specimen under the influence of the external magnetic fields, and vice versa. Below, in the framework of thermodynamic approach the boundary value problem for magnetoelectric plate is formulated and analyzed. The exact solution is established for the isotropic pyroelectric plate.

Multifunctional MXene/C Aerogels for Enhanced Microwave Absorption and Thermal Insulation

Two-dimensional transition metal carbides and nitrides(MXene)have emerged as promising candidates for microwave absorption(MA)materials.However,they also have some drawbacks,such as poor impedance matching,high self-stacking tendency,and high density.To tackle these challenges,MXene nanosheets were incorporated into polyacrylonitrile(PAN)nanofibers and subsequently assembled into a three-dimensional(3D)network structure through PAN carbonization,yielding MXene/C aerogels.The 3D network effectively extends the path of microcurrent transmission,leading to enhanced conductive loss of electromagnetic(EM)waves.Moreover,the aerogel’s rich pore structure significantly improves the impedance matching while effectively reducing the density of the MXenebased absorbers.EM parameter analysis shows that the MXene/C aerogels exhibit a minimum reflection loss(RL_(min))value of−53.02 dB(f=4.44 GHz,t=3.8 mm),and an effective absorption bandwidth(EAB)of 5.3 GHz(t=2.4 mm,7.44–12.72 GHz).Radar cross-sectional(RCS)simulations were employed to assess the radar stealth effect of the aerogels,revealing that the maximum RCS reduction value of the perfect electric conductor covered by the MXene/C aerogel reaches 12.02 dB m^(2).In addition to the MA performance,the MXene/C aerogel also demonstrates good thermal insulation performance,and a 5-mm-thick aerogel can generate a temperature gradient of over 30℃ at 82℃.This study provides a feasible design approach for creating lightweight,efficient,and multifunctional MXene-based MA materials.

Cellular response toβ-amyloid neurotoxicity in Alzheimer's disease and implications in new therapeutics

β-Amyloid(Aβ)is a specific pathological hallmark of Alzheimer's disease(AD).Because of its neurotoxicity,AD patients exhibit multiple brain dysfunctions.Disease-modifying therapy(DMT)is the central concept in the development of AD thera-peutics today,and most DMT drugs that are currently in clinical trials are anti-Aβdrugs,such as aducanumab and lecanemab.Therefore,understanding Aβ's neurotoxic mechanism is crucial for Aβ-targeted drug development.Despite its total length of only a few dozen amino acids,Aβis incredibly diverse.In addition to the well-known Aβ_(1-42),N-terminally truncated,glutaminyl cyclase(QC)catalyzed,and pyroglutamate-modified Aβ(pEAβ)is also highly amyloidogenic and far more cytotoxic.The extracel-lular monomeric Aβ_(x-42)(x=1-11)initiates the aggregation to form fibrils and plaques and causes many abnormal cellular responses through cell membrane receptors and receptor-coupled signal pathways.These signal cascades further influence many cel-lular metabolism-related processes,such as gene expression,cell cycle,and cell fate,and ultimately cause severe neural cell damage.However,endogenous cellular anti-Aβdefense processes always accompany the Aβ-induced microenvironment alterations.Aβ-cleaving endopeptidases,Aβ-degrading ubiquitin-proteasome system(UPS),and Aβ-engulfing glial cell immune responses are all essential self-defense mechanisms that we can leverage to develop new drugs.This review discusses some of the most recent advances in understanding Aβ-centric AD mechanisms and suggests prospects for promising anti-Aβstrategies.

Biomechanics associated with tibial stress fracture in runners:A systematic review and meta-analysis

Background:Tibial stress fracture(TSF)is an overuse running injury with a long recovery period.While many running studies refer to biomechanical risk factors for TSF,only a few have compared biomechanics in runners with TSF to controls.The aim of this systematic review and meta-analysis was to evaluate biomechanics in runners with TSF compared to controls.Methods:Electronic databases PubMed,Web of Science,SPORTDiscus,Scopus,Cochrane,and CINAHL were searched.Risk of bias was assessed and meta-analysis conducted for variables reported in 3 or more studies.Results:The search retrieved 359 unique records,but only the 14 that compared runners with TSF to controls were included in the review.Most studies were retrospective,2 were prospective,and most had a small sample size(5-30 per group).Many variables were not significantly different between groups.Meta-analysis of peak impact,active,and braking ground reaction forces found no significant differences between groups.Individual studies found larger tibial peak anterior tensile stress,peak posterior compressive stress,peak axial acceleration,peak rearfoot eversion,and hip adduction in the TSF group.Conclusion:Meta-analysis indicated that discrete ground reaction force variables were not statistically significantly different in runners with TSF compared to controls.In individual included studies,many biomechanical variables were not statistically significantly different between groups.However,many were reported by only a single study,and sample sizes were small.We encourage additional studies with larger sample sizes of runners with TSF and controls and adequate statistical power to confirm or refute these findings.

In situ TEM observations and molecular dynamics simulations of deformation defect activities in Mg via nanoindentation

In this work, we performed in situ nanoindentation in TEM to capture the real-time dislocation and twinning activities in pure Mg during loading and unloading. We demonstrated that the screw component of dislocations glides continuously, while the edge components rapidly become sessile during loading. The twin tip propagation is intermittent, whereas the twin boundary migration is more continuous. During unloading, we observed the elastic strain relaxation causes both dislocation retraction and detwinning. Moreover,we note that the plastic zone comprised of dislocations in Mg is well-defined, which contrasts with the diffused plastic zones observed in face-centered cubic metals under the nanoindentation impressions. Additionally, molecular dynamics simulations were performed to study the formation and evolution of deformation-induced crystallographic defects at the early stages of indentation. We observed that,in addition to dislocations, the I1stacking fault bounded with a <1/2c+p> Frank loop can be generated from the plastic zone ahead of the indenter, and potentially serve as a nucleation source for abundant dislocations observed experimentally. These new findings are anticipated to provide new knowledge on the deformation mechanisms of Mg, which are difficult to obtain through conventional ex situ approaches. These observations may serve as a baseline for simulation work that investigate the dynamics of dislocation slip and twinning in Mg and alloys.

Free-Standing α-MoO_(3)/Ti_(3)C_(2) MXene Hybrid Electrode in Water-in-Salt Electrolytes

While transition-metal oxides such as α-MoO_(3)provide high capacity,their use is limited by modest electronic conductivity and electrochemical instability in aqueous electrolytes.Two-dimensional(2D)MXenes,offer metallic conductivity,but their capacitance is limited in aqueous electrolytes.Insertion of partially solvated cations into Ti_(3)C_(2)MXene from lithium-based water-in-salt(WIS)electrolytes enables charge storage at positive potentials,allowing a wider potential window and higher capacitance.Herein,we demonstrate that α-MoO_(3)/Ti_(3)C_(2)hybrids combine the high capacity of α-MoO_(3)and conductivity of Ti_(3)C_(2)in WIS(19.8 m LiCI)electrolyte in a wide1.8 V voltage window.Cyclic voltammograms reveal multiple redox peaks from α-MoO_(3)in addition to the well-separated peaks of Ti_(3)C_(2)in the hybrid electrode.This leads to a higher specific charge and a higher rate capability compared to a carbon and binder containing α-MoO_(3)electrode.These results demonstrate that the addition of MXene to less conductive oxides eliminates the need for conductive carbon additives and binders,leads to a larger amount of charge stored,and increases redox capacity at higher rates.In addition,MXene encapsulated α-MoO_(3)showed improved electrochemical stability,which was attributed to the suppressed dissolution of α-MoO_(3).The work suggests that oxide/MXene hybrids are promising for energy storage.

Pharmacoepidemiologic study of association between apparent treatment resistant hypertension, cardiovascular disease and interaction effect by sex and age

BACKGROUND A limited number of studies have been conducted to test the magnitudes of the association between apparent treatment resistant hypertension(aTRH)and risk of cardiovascular disease(CVD).AIM To investigate the association between aTRH and risk of CVD and examine whether sex and age modify this association.METHODS We applied an observational analysis study design using data from the United States Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial(ALLHAT).ALLHAT recruited participants(n=25516)from 625 primary care settings throughout the United States,Canada,Puerto Rico,and United States Virgin Islands,aged 55 and older with hypertension and at least one additional risk factor for heart disease.aTRH was assessed from the year 2 visit.CVD event was defined as one of the following from the year 2 follow-up visit:Fatal or non-fatal myocardial infarction,coronary revascularization,angina,stroke,heart failure,or peripheral artery disease.Cox proportional hazards regression was used to examine the effect of aTRH on CVD risk.Potential modifications of sex and age on this association were examined on the multiplicative scale by interaction term and additive scale by joint effects and relative excess risk for interaction.RESULTS Of the total study participants(n=25516),5030 experienced a CVD event during a mean of 4.7 years follow-up.aTRH was associated with a 30%increase in risk of CVD compared to non-aTRH[hazards ratio(HR)=1.3,95%CI:1.19-1.42].Sex and age modified this relationship on both multiplicative and additive scales independently.Stratified by sex,aTRH was associated with a 64%increase in risk of CVD(HR=1.64,95%CI:1.43–1.88)in women,and a 13%increase in risk of CVD(HR=1.13,95%CI:1.01–1.27)in men.Stratified by age,aTRH had a stronger impact on the risk of CVD in participants aged<65(HR=1.53,95%CI:1.32–1.77)than it did in those aged≥65(HR=1.18,95%CI:1.05–1.32).Significant two-way interactions of sex and aTRH,and age and aTRH on risk of CVD were observed(P<0.05).The observed joint effect of aTRH and ages≥65 years(HR=1.85,95%CI:1.22–2.48)in males was less than what was expected for both additive and multiplicative models(HR=4.10,95%CI:3.63–4.57 and 4.88,95%CI:3.66–6.31),although three-way interaction of sex,age,and aTRH on the risk of CVD and coronary heart disease did not reach a statistical significance(P>0.05).CONCLUSION aTRH was significantly associated with an increased risk of CVD and this association was modified by both sex and age.Further studies are warranted to test these mechanisms.

A Vector Tensor Calculus Description of a Euclidean Space

We present a tensor description of Euclidean spaces that emphasizes the use of geometric vectors which leads to greater geometric insight and a higher degree of organization in analytical expressions. We demonstrate the effectiveness of the approach by proving a number of integral identities with vector integrands. The presented approach may be aptly described as absolute vector calculus or as vector tensor calculus.

Morphological Instability of Phase Interface between Pyroelectric Domains

The Gibbs-like variational methodology is applied to the heterogeneous systems with rigid pyroelectric or pyromagnetic domains. The processes of depolarization/demagnetization are taken into account by assuming the spatial mobility of the interfaces. The simplest configuration of flat interface separating rigid pyroelectric half-spaces permits explicit analysis of morphological stability.

Deformable Permanent Ferroelectric or Ferromagnetic Media

In the framework of continuum mechanics, one of possible consistent definitions of deformable permanent magnets is introduced and explored. Similar model can be used for ferroelectric substances. Based on the suggested definition, we establish the key kinematic relationship for the deformable permanent magnet and suggest the simplest master system, allowing to analyze behavior of such substances.

MXene ink hosting zinc anode for high performance aqueous zinc metal batteries

Despite the safety,low cost,and high theoretical capacity(820 mA h g^(-1))of Zn metal anodes,the practical application of aqueous Zn metal batteries remains a critical challenge due to the Zn dendrite growth,corrosion,and hydrogen evolution reaction.Herein,we demonstrate the MXene ink hosting Zn metal anodes(MX@Zn)for high-performance and patternable Zn metal full batteries.The as-designed MX@Zn electrode is more facile and reversible than bare Zn and CC@Zn,as verified by better cyclic stability and lower overpotentials of symmetric cells with the plating capacity of 0.05 mA h cm^(-2)at 0.1 m A cm^(-2)and of 1 m A h cm^(-2)at 1 m A cm^(-2).The MX@Zn|MnO_(2)full cells deliver a high specific capacity of 281.9 m A h g^(-1),91.5%of the theoretical capacity,achieving 50%capacity retention from 60 mA g^(-1)to 300 mA g^(-1)and 79.7%of initial capacity after 200 cycles.Moreover,the patterned devices based on the MX@Zn electrode achieve high energy and power densities of 348.57 Wh kg^(-1)and 1556 W kg^(-1),respectively,along with a capacity retention of 64%and Coulombic efficiency of 99%over 500 cycles.The high performance of MX@Zn is attributed to the high electrical conductivity and hydrophilicity of MXene and rapid ion diffusion through the 3D interconnected porous channels.

菲在土壤/沉积物上的吸附-解吸过程及滞后现象的研究

实验研究了菲在土壤 /沉积物上的吸附 解吸过程。CHL土壤和HFH沉积物中有机质的固相13 CCPMASNMR谱图很相似 ,表明样品中有机质的组成差异不大 ;菲在土壤 /沉积物上的吸附过程表现出明显的非线性 ;线性模型不适合拟合菲的吸附等温线 ,Freundlich模型和双区位反应模型 (DRDM)较好地拟合了菲的吸附等温线 ,其中DRDM模型还清楚地反映菲在低浓度和高浓度下不同的吸附方式 ;另外 ,研究表明菲在土壤 /沉积物上的解吸过程中存在明显的滞后现象 ,这可能和土壤 /沉积物有机质的异质性和土壤胶团微小孔隙的存在有关。

脱细胞真皮基质的改建及其作为软骨细胞移植载体在兔软骨缺损修复中的应用

目的:探讨脱细胞真皮(acellular dermal matrix,ADM)经改建后作为软骨细胞移植载体的可行性。方法:取新生小牛背部真皮组织,分别用自制脱细胞剂和表面活性剂对其进行脱细胞处理后,观察得出自制脱细胞剂脱细胞的效果良好,但脱细胞后的胶原纤维结构需要改建;将自制脱细胞剂脱细胞后的真皮组织分别用按一定浓度配比的消化液和胃蛋白酶消化,发现经配比消化液改建后的胶原纤维表面光滑、孔隙均匀,符合软骨细胞移植载体的要求;比较戊二醛和水溶性交联剂对改建后脱细胞真皮基质的交联效果,可见水溶性交联剂交联后的ADM载体植入大鼠皮下后,其生物相容性良好;用生长因子对改建和交联后的ADM进行纤维表面修饰,然后接种乳兔软骨细胞,观察细胞粘附及生长情况;最后将接种有兔自体软骨细胞的ADM植入兔胫骨软骨缺损部位,术后定期取材观察修复效果。结果:(1)经戊二醛交联后的ADM植入大鼠皮下后有强烈的炎症反应,并有组织出血坏死;而经水溶性交联剂交联的ADM的组织相容性较好。(2)在植入接种有自体软骨细胞的ADM24周后,大白兔胫骨的软骨缺损修复完好,附和的细胞能够存活且增殖,ADM本身基本降解。结论:经脱细胞、纤维改建、交联及生长因子修饰的ADM孔隙均匀,组织相容性好,适于细胞粘附及长期生长。ADM胶原支架在兔体内可基本降解,未见排异反应,移植24周后骨缺损修复。

改建脱细胞真皮基质作为软骨细胞移植载体修复兔软骨缺损(英文)

背景:脱细胞真皮(Acellular Dermal Matrix,ADM)具有良好的柔韧性、易于修剪,制成微粉状皮内或皮下注射后,可见到成纤维细胞的移入及胶原的沉积,目前己被广泛应用于整形修复临床实践。目的:验证脱细胞真皮经改建后作为软骨细胞移植载体的可行性。设计、时间及地点:对比观察,于2003-08/2007-02在北京大学医学部和北京积水潭医院完成。材料:新生小牛的真皮层由北京元亨圣马生物研究所提供;体质量250g的SD健康成年大白鼠24只,雌雄不限。3月龄的新西兰大白兔36只。方法:①取新生小牛背部真皮组织,进行脱细胞处理,分别用戊二醛和水溶性交联剂进行交联;再用生长因子对其进行纤维表面修饰。②取SD大白鼠,于大鼠脊柱两侧各设计3个长方形皮瓣,分别植入两组交联后的脱细胞真皮基质。术后2,6,12周取出植入物。③取新西兰大白兔,分为实验组和对照组,从其左侧关节面取原代软骨,分离软骨细胞并接种于复合后的ADM上进行培养。将实验组兔右侧后肢造成软骨缺损,植入含有自体软骨细胞的ADM,再将生物胶滴加于载体表面;对照组兔右侧后肢造成软骨缺损后分层缝合伤口。分别于第4,12,24周取材,对照组每次取2只,实验组每次取5只。主要观察指标:①交联效果的比较。②兔软骨缺损修复结果。结果:①经戊二醛交联后的ADM植入大鼠皮下后有强烈的炎症反应,并有组织出血坏死;而经水溶性交联剂交联的ADM的组织相容性较好。②在植入接种有自体软骨细胞的ADM24周后大白兔股关节的软骨缺损修复完好,附和的细胞能够存活且有增殖,ADM本身基本降解。结论:经脱细胞及纤维改建和交联及生长因子修饰的ADM孔隙均匀,组织相容性好,适于细胞黏附及长期生长。ADM胶原支架在兔体内可基本降解,未见排异反应,移植24周后见骨缺损修复。

分子筛生产废水在浮选药剂合成中的应用

通过皂化反应试验和浮选试验,对废碱液作为氢氧化钠的替代品用于皂化,改善脂肪酸的捕收性能的应用进行研究。皂试验结果表明,皂化反应的最佳条件为:搅拌速度55 r/min、起始温度40℃和搅拌时间45 min。同时,实验室规模和工业规模的浮选试验表明,废水合成的脂肪酸盐得到与氢氧化钠合成的脂肪酸钠相当的指标。因此,用来自分子筛生产过程中产生的废水代替氢氧化钠用于脂肪酸皂化是可行的。废碱液的跨界利用不仅减少环境污染,同时还产生良好的经济效益。

液晶混合光学双稳装置中分叉和混沌行为

本文报道在t_R>>τ(t_R为反馈系统延迟时间,τ为液晶的弛豫时间)条件下,液晶混合光学双稳装置中,随着系统参数的改变,自脉冲经倍周期分叉发展到混沌的过程。计算了分叉图,通过频谱和相空间图能清晰地分析系统的动态行为。实验结果与Ikeda理论进行了比较。

氩气等离子体射流诱导水生成OH自由基的研究

·OH在众多领域中具有非常重要的作用,在国际上引起了广泛关注,而大气压等离子体射流由于不需要真空、装置简单易于携带,且具有高浓度活性粒子、高电子温度、低射流温度等优点,具有极强的应用前景,成为气体放电领域的重要研究课题。特别是如何诱导等离子体射流中·OH的产生已成为等离子体射流领域一个新的研究热点。国外率先报道了将水蒸汽以一定的比例混入等离子体射流工作气体中以诱导产生大量·OH的研究,然而当含水量较高时,射流会剧烈摆动,放电变得十分不均匀、不稳定。为此,本文设计了一种大气压双环电极氩气等离子体射流诱导水产生·OH的装置,通过引入超声雾化装置增加等离子体羽周围的湿度以提高·OH含量,重点研究了不同电压、流量下诱导水生成OH(A2Σ+)的生成规律;利用发射光谱法测试了装置产生·OH的含量;并利用810.41和811.48nm这两条Ar原子光谱线,计算了等离子体羽中的电子温度。结果表明等离子体羽可以诱导周围的水产生·OH,且随电压从20kV增大到28kV时,OH(A2Σ+)的产量逐渐增大;而当氩气流量从100L·h-1增大到200L·h-1时,·OH产量随着流量的增大而增大,但是当氩气流量从200L·h-1增大到600L·h-1时,·OH产量随着流量的增大而不断减小。OH(A2Σ+)的产量和电子温度变化趋势完全一致,证明了·OH的产量主要受电子温度的影响。