Covalently Assembled Dipeptide Nanoparticles with Adjustable Fluorescence Emission for Multicolor Bioimaging

Peptide self-assembly, inspired by the naturally occurring fabrication principle, remains the most attractive in constructing fluorescent nanoagents towards bioimaging. However, the noncovalent interactions that drive peptide self-assembly are usually susceptible to the complex physiological environment; thus leading to disassembly and dysfunction of fluorescent nanoagents. Herein, a covalently crosslinked assembly strategy for fabrication of stable peptide-based nanoparticles with adjustable emission is introduced. In the process of cationic diphenylalanine peptide (H-Phe-Phe-NH₂ ⋅ HCl) self-assembly, glutaraldehyde is used as a crosslinker and the resulting product of the Schiff base reaction can be fluorescent. More importantly, the emission wavelength can be readily tuned by controlling the covalent reaction time. It has been demonstrated that the nanoparticles are stable, even after intracellular uptake, and can be used for sustainable multicolor fluorescent imaging. The strategy with integrating peptide self-assembly and covalent crosslinking could be promising for the design and engineering of functional fluorescent nanoparticles with robust physiological stability and adjustable emission towards improved bioimaging applications.     

基于CSC方法的钢铁行业节能减排技术潜力分析

为了研究中国钢铁行业的节能减排潜力，以35项钢铁行业先进节能减排技术为研究对象，建立节能供应曲线(Conservation Supply Curve，简称CSC)模型，分析影响钢铁行业的节能减排收益、成本效益以及钢铁生产流程工序层面的节能减排潜力因素。结果表明，这35项技术全部应用可实现3.01 GJ/t的节能量以及398.22 kg/t的CO2减排量。将结果与第十三个五年计划推广技术作对比，在当前情况下，约有50%的推广技术并不符合成本效益；运用CSC模型进行了钢铁生产流程工序层面的节能减排潜力研究，得到各个工序的节能量和减排量，并据此分析了各项技术未来的发展趋势和应用前景。     

电感耦合等离子体原子发射光谱法测定辛酸铑催化剂中铂钯铅铁铜铝镍

准确测定辛酸铑催化剂中杂质元素含量,是判定产品是否合格的重要指标之一。以往常采用直流电弧发射光谱法(摄谱法)进行检测,但测定周期长,且重复性较差。用电感耦合等离子体原子发射光谱法(ICP-AES)测定辛酸铑催化剂中微量杂质元素时,辛酸铑催化剂样品中含有的大量有机组分和铑基体会对测定有严重干扰。实验采用反复滴加硝酸消解样品中有机组分,再用王水溶解盐类,选用合适背景点扣除的方式消除铑基体的干扰,建立了使用ICP-AES测定辛酸铑催化剂中0.001%~0.1%(质量分数)Pt、Pd、Pb、Fe、Cu、Al、Ni等7种微量杂质元素的方法。各元素在0.10~10.00μg/mL范围内与其发射强度呈线性关系,相关系数均大于0.9999;方法检出限(μg/mL)为0.075(Pt)、0.0033(Pd)、0.015(Pb)、0.0036(Fe)、0.010(Cu)、0.001(Al)、0.012(Ni)。实验方法用于测定辛酸铑催化剂样品中Pt、Pd、Pb、Fe、Cu、Al、Ni,结果的相对标准偏差为(RSD,n=7)为1.4%~9.6%。按照实验方法测定辛酸铑催化剂中Pt、Pd、Pb、Fe、Cu、Al、Ni,并与直流电弧发射光谱法的测定结果进行比对,结果相一致。     

配加预处理脱硫灰对铁矿烧结基础特性的影响

 半干法脱硫灰堆弃处理占用土地且容易造成二次污染,将脱硫灰预处理后替代CaO熔剂配入烧结有望充分利用其中的熔剂组分,实现脱硫灰在钢铁企业的闭路资源化利用。研究了脱硫灰配加焦粉加热分解特性及替代CaO熔剂配加对铁矿粉烧结基础特性的影响。结果表明,配加1%焦粉可以有效提高脱硫灰分解率,减少CaSO₄的生成。随着预处理脱硫灰替代CaO比例的增加,铁矿粉同化温度和黏结相强度呈现先增加后减小的趋势;液相流动性呈现单调增加趋势,当替代比超过40%时,液相流动性形成了流动性很大的“假象”;黏结相微观结构表明,替代比例小于40%时,有利于烧结试样中铁酸钙的生成;综合考虑,最佳的替代比例应小于40%。     

露天采场高陡边坡下深部采空区的爆破处理研究

鞍本地区是我国最大的BIF型铁矿集中分布区,其铁矿资源量/储量约占全国总量的1/4,但由于日伪时期的掠夺式开采和矿业整合开发前的无序开发利用,在一定深度空间内遗留了大量隐伏采空区,为后期实现规模化露天开采带来极大的安全隐患,成为制约露天铁矿资源安全高效开采的难题。以弓长岭露天铁矿大砬子采区高陡边坡下的深部采空区为研究对象,利用LS_DYNA软件进行采空区的安全爆破模拟研究,结合现场深部采空区爆破参数试验结果,提出了采用孔中起爆处理采空区的方法,具体参数设置为空区预留顶板厚度3 m,孔间延期时间42 ms,排间延期时间75 ms,平均炸药单耗0.237 kg/t。在上述分析的基础上,针对大砬子露天采场高陡边坡内的深部不规则多层采空区提出了分层、分区安全爆破处理的技术方案,且空区边界用切割爆破方法处理,爆破处理效果良好,采空区得到了安全有效治理。     

Scavenging Bacterial Siderophores with Engineered Lipocalin Proteins as an Alternative Antimicrobial Strategy

Iron acquisition mediated by siderophores, high-affinity chelators for which bacteria have evolved specific synthesis and uptake mechanisms, plays a crucial role in microbiology and in host–pathogen interactions. In the ongoing fight against bacterial infections, this area has attracted biomedical interest. Beyond several approaches to interfere with siderophore-mediated iron uptake from medicinal and immunochemistry, the development of high-affinity protein scavengers that tightly complex the siderophores produced by pathogenic bacteria has appeared as a novel strategy. Such binding proteins have been engineered based on siderocalin—also known as lipocalin 2—an endogenous human scavenger of enterobactin and bacillibactin that controls the systemic spreading of commensal bacteria such as Escherichia coli. By using combinatorial protein design, siderocalin was reshaped to bind several siderophores from Pseudomonas aeruginosa and, in particular, petrobactin from Bacillus anthracis, none of which is recognized by the natural protein. Such engineered versions of siderocalin effectively suppress the growth of corresponding pathogenic bacteria by depriving them of their iron supply and offer the potential to complement antibiotic therapy in situations of acute or persistent infection.     

Epigenetic Targets for Oligonucleotide Therapies of Pulmonary Arterial Hypertension

Arterial wall remodeling underlies increased pulmonary vascular resistance and right heart failure in pulmonary arterial hypertension (PAH). None of the established vasodilator drug therapies for PAH prevents or reverse established arterial wall thickening, stiffening, and hypercontractility. Therefore, new approaches are needed to achieve long-acting prevention and reversal of occlusive pulmonary vascular remodeling. Several promising new drug classes are emerging from a better understanding of pulmonary vascular gene expression programs. In this review, potential epigenetic targets for small molecules and oligonucleotides will be described. Most are in preclinical studies aimed at modifying the growth of vascular wall cells in vitro or normalizing vascular remodeling in PAH animal models. Initial success with lung-directed delivery of oligonucleotides targeting microRNAs suggests other epigenetic mechanisms might also be suitable drug targets. Those targets include DNA methylation, proteins of the chromatin remodeling machinery, and long noncoding RNAs, all of which act as epigenetic regulators of vascular wall structure and function. The progress in testing small molecules and oligonucleotide-based drugs in PAH models is summarized.     

氯化铵蒸发器结垢成分鉴别及原因分析

多效蒸发器结垢的问题常常发生,影响热效率和装置的正常运行。为明确导致蒸发器结垢的原因和成分,利用X射线衍射（XRD）、等离子发射光谱（ICP）、扫描电镜能谱（SEM-EDS）、偏光显微镜、拉曼光谱和离子色谱等分析测试技术,对浙江大洋生物科技集团股份有限公司的氯化铵多效蒸发器上的不明结垢物做了表征和分析。结果表明,该结垢物的主要成分为磷酸铁、氧化铝和有机物的混合物。探讨了发生上述结垢的原因,并提出相应的解决方案,减少了公司氯化铵蒸发器的结垢。     

Fabrication of 3D Ni nanosheet array on Crofer22APU interconnect and NiO-YSZ anode support to sinter with small-size Ag nanoparticles for low-temperature sealing SOFCs

A novel low-temperature sealing method was developed to seal solid oxide fuel cells. The 3D Ni nanosheet array was pre-fabricated on faying surfaces of Crofer22APU interconnect and NiO-YSZ anode-support. Then it was covered with Au film without changing its morphology. This special nanostructure improved sintering efficiency between Ag nanoparticles and substrates. A dense joint was obtained at the low-temperature between 250 °C–300 °C. This method effectively avoided the oxidation of interconnect during sealing. When joints were sealed at 300 °C, the shear strength reached 16 MPa. The fracture was mainly located in the central Ag layer, presenting a significant plastic deformation. Due to the effective protection of Ni layer, joints also possessed excellent oxidation resistance in oxidizing atmosphere at 800 °C for 400 h. After high-temperature oxidation, the shear strength was increased to 23 MPa, revealing an increasement of 43.8% compared with the as-sealed condition (16 MPa). This sealing method has great potential in sealing solid oxide fuel cells. It also can be extended to seal other energy-conversion devices.     

Enhanced hydrogen storage performance of three-dimensional hierarchical porous graphene with nickel nanoparticles

Three-dimensional hierarchical porous graphene with nickel nanoparticles (3DHPG-Ni) was synthesized through electrostatic assembly method with the assistance of poly (methyl methacrylate) (PMMA) template and subsequent removal of PMMA template by calcination. The morphology, microstructure and hydrogen adsorption properties of 3DHPG-Ni nanocomposites were examined in detail. The obtained 3DHPG-Ni nanocomposite exhibited hierarchical porous structure composed of macro-, meso- and micropores, high specific surface area (925 m² g^?1), large pore volume (0.58 cm³ g^?1) and excellent hydrogen storage capacity. Under the pressure of 5 bar, 3DHPG-Ni nanocomposite showed a maximum hydrogen capacity of 4.22 wt% and 1.95 wt% at 77 K and 298 K, respectively, demonstrating that the as-prepared 3DHPG-Ni nanocomposite was supposed to be a promising material with outstanding properties for practical applications in the field of hydrogen storage. The three-dimensional hierarchical porous structure, evenly distributed Ni nanoparticles and hydrogen spillover effect were responsible for the enhanced hydrogen storage capacities.