Synergistic activation of smithsonite with copper-ammonium species for enhancing surface reactivity and xanthate adsorption

Copper ions(Cu^(2+))are usually added to activate the sulfidized surface of zinc oxide minerals to enhance xanthate attachment using sulfidization xanthate flotation technology.The adsorption of Cu^(2+)and xanthate on the sulfidized surface was investigated in various systems,and its effect on the surface hydrophobicity and flotation performance was revealed by multiple analytical methods and experiments.X-ray photoelectron spectroscopy(XPS)and time-of-flight secondary ion mass spectrometry(To F-SIMS)characterization demonstrated that the adsorption of Cu^(2+)on sulfidized smithsonite surfaces increased the active Cu—S content,regardless of treatment in any activation system.The sulfidized surface pretreated with NH_(4)^(+)-Cu^(2+)created favorable conditions for the adsorption of more Cu^(2+),significantly enhancing the smithsonite reactivity.Zeta potential determination,ultraviolet(UV)-visible spectroscopy,Fourier transform-infrared(FT-IR)measurements,and contact angle detection showed that xanthate was chemically adsorbed on the sulfidized surface,and its adsorption capacity in various systems was illustrated from qualitative and quantitative aspects.In comparison to the Na2S–Cu^(2+)and Cu^(2+)–Na2S–Cu^(2+)systems,xanthate exhibited a higher adsorption capacity on sulfidized smithsonite surfaces in NH_(4)^(+)-Cu^(2+)–Na2S–Cu^(2+)system.Hence,activation with Cu^(2+)–NH4+synergistic species prior to sulfidization significantly enhanced the mineral surface hydrophobicity,thereby increasing its flotation recovery.

Flotation of copper oxide minerals:A review

Copper oxide minerals are important copper resources,which include malachite,azurite,chrysocolla,cuprite,etc.Flotation is the most widely used method for the enrichment of copper oxide minerals in the mineral processing industry.In this paper,the surface properties of copper oxide minerals and their effects on the mineral flotation behavior are systematically summarized.The flotation methods of copper oxide minerals and the interaction mechanism with reagents are reviewed in detail.Flotation methods include direct flotation(using chelating reagents or a fatty acid as collector),sulfidization flotation(using xanthate as collector),and activation flotation(using chelating reagents,ammonium/amine salts,metal ions,and oxidant for activation).An effective way to realize efficient flotation of copper oxide minerals is to increase active sites on the surface of copper oxide minerals to enhance the interaction of collector with the mineral surface.Besides,various perspectives for further investigation on the efficient recovery of copper oxide minerals are proposed.

上海市综合医院内科医护人员对善终感知的调查研究

目的探讨综合医院内科医护人员对善终内涵的理解。方法采用面对面半结构式访谈收集资料。于2020年10月至2021年1月,在上海市8所综合医院中有目地的选取有内科工作、照顾终末期慢性病患者经验的16名医生和13名护士进行访谈,并采用内容分析法对资料进行分析。结果善终的内涵可以概括为六个主题,包括无痛苦、家人的陪伴与照顾、无牵挂、有尊严、尽力与接受、对家庭影响小。并提炼出一系列子主题,包括感知不到痛苦地离世、缓解症状、避免无效医疗措施及有创抢救措施、缓解心理痛苦;家人的陪伴照顾和医疗护理服务;人生圆满、做好安排、完成告别;在体面的环境中离世、个人意愿得到尊重、躯体完整、生活有质量;家属及医护人员对患者死亡的接受和家属及医护人员在照顾临终患者过程中的尽力感;对家庭负担影响小、对患者生活质量影响小、提高家庭凝聚力。结论患者临终过程中家人参与照顾对最终达到善终有积极作用。避免和减少使用无效医疗措施及有创抢救措施是促进我国终末期患者获得善终以及推动预立医疗照护计划发展的第一步。

Experimental Research on Toluene Degradation in Plasma as the Driving Force of Nanomaterials

Plasma technology has some shortcomings, such as higher energy consumption and byproducts produced in the reaction process. However non-thermal plasma associated with catalyst can resolve these problems. So this kind of technology was paid more and more attention to treat waste gas. In this paper, we make use of this technology to decompose toluene under different electric field and packed materials. At the same time, the mechanism of toluene decomposition using plasma and catalyst is discussed. The experimental results show toluene decomposition increases with electric field strength increasing and flow velocity and initial concentration decreasing. There are four conditions in plasma: without packed materials (1);with packed materials (2);with BaTiO3 in the surfaces of packed materials (3);and with nanometer Ba0.8Sr0.2Zr0.1Ti0.9O3 (4). Toluene decomposition represents a obvious trend, that is, η(4) > η(3) > η(2) > η(1). The best decomposition efficiency of toluene arrives at 95%.

The Effects of Simulated Microgravity on Immune Function of Macrophages

Since the 1 960 s,many successful space missions have highlighted the advantages and necessity of humans in the exploration of space,but scientists have long worried about the adverse effects of spaceflight on Astronaut.Space flight and models that create conditions similar to those that occur during space flight have been shown to deleteriously affect a variety of immunological responses.The mechanisms and biomedical consequences of these changes remain to be established.Conducting experiments in an environment of true microgravity requires a roundtrip ticket into space,a feat that is both expensive and challenging.Simulated microgravity(SMG)models allow scientists to gather preliminary data without the cost and logistical challenges of spaceflight.The objective of the present study was to evaluate the effects of SMG on immunity function of macrophages that exposed to RPM and RCCS separately.While many studies have demonstrated that alterations occur in the immune system as a result of space travel,the level at which these mechanisms exert their effect,at the level of the mature immune cell or earlier at the progenitor or stem cell stage is not known.In particular,macrophages,as one of the most important immune cells and play a key role in both specific and non-specific immunity,did not have received much attention.Therefore,in our study,we mainly study the influence of microgravity on the immune function of macrophages.In this study,we evaluated the immune dysfunction of macrophages under SMG.Firstly,we found that the morphology and structure of the macrophages were changed,specifically,we observed that there were more protrusions on cell surface and the cells were shrinking significantly after exposure to SMG.Secondly,we demonstrated that under simulated microgravity(SMG)conditions,the phagocytic and proliferative functions of macrophages were significantly reduced.Thirdly,several processes,including surface receptor expression,cytoskeleton,and cytokines secreted were investigated in macrophages under SMG.Phagocytosis is one of the important means for macrophages to exert immune function,and cell surface phagocytosis-related receptors play an important role.Here,we selected four common receptors(TLR2,FcyR1,CD11b and CD 18)to detect.The results indicate that SMG(RPM and RCCS)have a great influence on the expression of surface phagocytosis-related receptors,which may be one of the main reasons for the decline of immune function ofmacrophages.Macrophages exert immune function through phagocytosis,and the cytoskeleton plays an important role in the process of phagocytosis.The results indicate that SMG(RPM and RCCS)have a great influence on the expression of cytoskeleton-related proteins,which provides me with a new idea that SMG may regulate immunity of macrophage by affecting the cytoskeleton.Immune-related cytokines play an important role in macrophage immune process.Here,we selected four common immunocytokine(TNF-α,IL-1β,IL-6 and IL-10)to detect.The change of these four immunocytokine further demonstrate that SMG significantly decline the immunity of macrophage,we must pay enough attention to the impact of SMG on macrophage.The above factors such as the changes of morphology and structure of the macrophages and the decreased expression of Arp2/3 complex related proteins,cytokine secretion,and cell surface receptors may be responsible for the immune dysfunction of macrophages under SMG.

Surface effect on band structure of magneto-elastic phononic crystal nanoplates subject to magnetic and stress loadings

This paper presents a theoretical model for the size-dependent band structure of magneto-elastic phononic crystal(PC)nanoplates according to the Kirchhoff plate theory and Gurtin-Murdoch theory,in which the surface effect and magneto-elastic coupling are considered.By introducing the nonlinear coupling constitutive relation of magnetostrictive materials,Terfenol-D/epoxy PC nanoplates are carried out as an example to investigate the dependence of the band structure on the surface effect,magnetic field,pre-stress,and geometric parameters.The results show that the surface effect has promotive influence on dispersion curves of the band structure,and the band gaps can be improved gradually with the increase in the material intrinsic length.Meanwhile,the band gaps exhibit obvious nonlinear coupling characteristics owing to the competition between the magnetic field and the pre-stress.By considering the surface effect and magneto-elastic coupling,the open and closed points of band gaps are found when the lattice constant to thickness ratio increases.The study may provide a method for flexible tunability of elastic wave propagation in magneto-elastic PC nanoplates and functional design of highperformance nanoplate-based devices.

Livelihood Capital and Livelihood Diversification for Different Farmers in Yuanjiang Dry-Hot River Valley

Under the analytical framework of sustainable livelihoods,we establish the evaluation indicator system for farmers' livelihood capital,to evaluate the current livelihood capital and livelihood diversification for different farmers in the Dai nationality region of Xinping County in the Yuanjiang dry-hot river valley area,and discuss the relationship between livelihood capital and livelihood diversification. Studies have shown that the mode dominated by agriculture,supplemented by non-agricultural activities,combined with breeding,is the commonly used livelihood strategy for farmers in this region. As farmers change from pure agriculture to non-agriculture,their total livelihood capital and nonagricultural livelihood diversification index will increase,while agricultural livelihood diversification index will decrease. In the meantime,their livelihood activities gradually shift from agricultural to non-agricultural ones,which is mainly reflected in the combination of both agricultural and non-agricultural activities. Regression analysis on livelihood capital and livelihood diversification shows that natural and physical capital is the basis of realizing agricultural livelihood diversification. Farmers with rich natural and physical capital will prefer agricultural livelihood strategies. While financial and human capital is the driving force for farmers' transition from pure agriculture to non-agriculture.

Macrophage LMO7 deficiency facilitates inflammatory injury via metabolic-epigenetic reprogramming

Inflammatory bowel disease(IBD)is a formidable disease due to its complex pathogenesis.Macrophages,as a major immune cell population in IBD,are crucial for gut homeostasis.However,it is still unveiled how macrophages modulate IBD.Here,we found that LIM domain only 7(LMO7)was downregulated in pro-inflammatory macrophages,and that LMO7 directly degraded 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3(PFKFB3)through K48-mediated ubiquitination in macrophages.As an enzyme that regulates glycolysis,PFKFB3 degradation led to the glycolytic process inhibition in macrophages,which in turn inhibited macrophage activation and ultimately attenuated murine colitis.Moreover,we demonstrated that PFKFB3 was required for histone demethylase Jumonji domaincontaining protein 3(JMJD3)expression,thereby inhibiting the protein level of trimethylation of histone H3 on lysine 27(H3K27me3).Overall,our results indicated the LMO7/PFKFB3/JMJD3 axis is essential for modulating macrophage function and IBD pathogenesis.Targeting LMO7 or macrophage metabolism could potentially be an effective strategy for treating inflammatory diseases.

一种新型酰胺功能化的共价有机框架用于选择性染料吸附

共价有机框架(covalent organic framework, COF)是一种由轻质元素(C、H、O和N)以共价键的形式连接组成的结晶多孔聚合物,由于其具有规则的孔道、可修饰的骨架以及良好的稳定性而被广泛应用于不同的领域.尤其是将含氮的功能基团连接到COF的骨架中,可以为其吸附特定的染料提供丰富的活性位点.基于此,本工作成功制备了一种酰胺功能化的二维共价有机框架材料(JUC-578),通过一系列的表征证明了该材料具有高的结晶度、均一规整的形貌以及开放的一维介孔孔道.更重要的是,发现JUC-578可以选择性地吸附阳离子染料,并且可以多次循环利用.这主要归因于骨架中的氮作为电子给体与缺电子的染料之间的静电作用以及其他弱相互作用(氢键、偶联作用等).与此同时,JUC-578高的结晶度和有序的孔道也是实现可逆吸附染料非常重要的因素.

Temperature-induced Lifshitz transition in topological insulator candidate HfTe_5

The ongoing discoveries and studies of novel topological quantum materials have become an emergent and important field of condensed matter physics.Recently,HfTe_5 ignited renewed interest as a candidate of a novel topological material.The single-layer HfTe_5 is predicted to be a two-dimensional large band gap topological insulator and can be stacked into a bulk that may host a temperature-driven topological phase transition.Historically,HfTe_5 attracted considerable interest for its anomalous transport properties characterized by a peculiar resistivity peak accompanied by a sign reversal carrier type.The origin of the transport anomaly remains under a hot debate.Here we report the first high-resolution laser-based angle-resolved photoemission measurements on the temperature-dependent electronic structure in HfTe_5.Our results indicated that a temperature-induced Lifshitz transition occurs in HfTe_5,which provides a natural understanding on the origin of the transport anomaly in HfTe_5.In addition,our observations suggest that HfTe_5 is a weak topological insulator that is located at the phase boundary between weak and strong topological insulators at very low temperature.

Electronic structure of exfoliated millimeter-sized monolayer WSe2 on silicon wafer

The mono layer WSe2 is in teresting and important for future application in nanoelectronics,spintronics and valleytronics devices,because it has the largest spin splitting and Ion gest valley coherence time among all the known monolayer transition-metal dichalcogenides(TMDs).Toobtain the large-area monolayer TMDs'crystal is the first step to manu facture scalable and high-performance electronic devices.In this letter,we have successfully fabricated millimeter-sized mono layer WSe2 single crystals with very high quality,based on our improved mecha nicalexfoliation method.With such superior samples,using standard high resolution angle-resolved photoemission spectroscopy,we didcomprehe nsive electronic band structure measurements on our mono layer WSe2.The overall band features point it to be a 1.2 eV direct bandgap semico nductor.Its spin splitting of the valence band at K point is found as 460 meV,which is 30 meV less than the corresponding band splitting in its bulk counterpart.The effective hole masses of valence bands are determined as 2.344 me atГ,and 0.529 me as well as 0.532 meat K for the upper and lower branch of splitting ban ds,respectively.And screening effect from substrate is shown to substa ntially impact onthe electronic properties.Our results provide importa nt insights into band structure engineering in mono layer TMDs.Our mono layer WSe2 crystals may constitute a valuable device platform.

Spatial distribution of health risks for residents located close to solvent-consuming industrial VOC emission sources

Emissions derived from the consumption of organic solvents have been proven to be the primary industrial source of volatile organic compounds(VOCs).In conjunction with epidemiologic studies, water-based paints(WBPs) and solvent-based paints(SBPs) were selected as representatives of newly developed solvents and traditional solvents, respectively,to simulate the effects of consuming solvents emitted during industrial production.And non-carcinogenic and carcinogenic risks to residents near emission sources were studied in detail.The results showed that the spatial distribution of health risks varied with meteorological conditions and type of emission source, and the prevailing wind direction strongly affected the distribution range and shape of the influenced area.The areas of influence maximized on heavy-polluting days for both WBP and SBP emission sources with the total span reaching 804 m and 16 km, respectively;meanwhile, the areas of influence for carcinogenic risk resulting from WBP emission sources were 1.2 and 2.3 times greater than those measured on fine and rainy days, respectively, and 1.8 and 2.9 times greater for SBP emission sources.Compared with WBPs, the total spans of negatively influenced regions resulting from SBP emission sources were 10.4, 12.5 and 19.9 times greater on fine, rainy and heavypolluting days, respectively.Therefore, carcinogenic risk was the dominant health threat for populations residing close to solvent-consuming industrial emission sources.The findings suggest that newly developed solvents are capable of significantly reducing consequent health threats, nevertheless, they could still pose occasional threats to nearby residents under specific meteorological conditions.

Defining Proximity Proteome of Histone Modifications by Antibody-mediated Protein A-APEX2 Labeling

Proximity labeling catalyzed by promiscuous enzymes,such as APEX2,has emerged as a powerful approach to characterize multiprotein complexes and protein-protein interactions.However,current methods depend on the expression of exogenous fusion proteins and cannot be applied to identify proteins surrounding post-translationally modified proteins.To address this limitation,we developed a new method to label proximal proteins of interest by antibody-mediated protein A-ascorbate peroxidase 2(pA-APEX2) labeling(AMAPEX).In this method,a modified protein is bound in situ by a specific antibody,which then tethers a pA-APEX2 fusion protein.Activation of APEX2 labels the nearby proteins with biotin;the biotinylated proteins are then purified using streptavidin beads and identified by mass spectrometry.We demonstrated the utility of this approach by profiling the proximal proteins of histone modifications including H3 K27 me3,H3 K9 me3,H3 K4 me3,H4 K5 ac,and H4 K12 ac,as well as verifying the co-localization of these identified proteins with bait proteins by published ChIP-seq analysis and nucleosome immunoprecipitation.Overall,AMAPEX is an efficient method to identify proteins that are proximal to modified histones.

高脂饮食对小鼠胃蛋白质组表达水平的影响

以高脂饮食小鼠为模型,多角度分析高脂饮食对小鼠胃蛋白组表达的影响。实验小鼠(C57BL/6)随机分配两组,实验组食用高脂饲料,对照组食用正常饲料,喂养110d后,把胃组织分为前胃、胃体和胃窦3个区分别进行蛋白质谱鉴定,随后比较两组实验的蛋白表达谱,分别筛选两组之间的差异蛋白以及胃分区的差异蛋白(差异倍数≥2),并对其进行GO富集及蛋白相互作用网络分析。对照组和实验组共鉴定到9 307种蛋白,筛选特异性肽段≥1且重复实验中至少鉴定到2次的蛋白,最后剩余4 066种蛋白,其中对照组3654种,实验组3832种。进一步从生物功能角度整体分析了胃组织的蛋白表达谱,结果发现实验组小鼠胃组织中高表达蛋白主要参与蛋白稳定和运输等生物学过程。而在对胃分区差异蛋白的功能分析表明,前胃主要参与角质化和肌动蛋白组装相关生物学过程,且受饮食影响程度较小;胃体和胃窦主要执行消化功能,高脂饮食后对胃的基本消化功能并无显著影响,但与对照组相比,参与蛋白转运和脂肪代谢相关生物学过程的蛋白显著高表达。