Facile construction of cellulose/layered double hydroxides nanocomposite membranes with high strength and antibacterial properties

High-strength regenerated cellulose/ZnAl-layered double hydroxides (LDH) composite membranes (RCL) with good mechanical and antibacterial performance were developed by stirring vigorously cellulose and LDH in NaOH/urea aqueous solvent system at −12°C. The obtained cellulose/LDH composited materials were characterized and the results indicated that well dispersion of LDH in the cellulose matrix. The tensile strength of RCL membranes were enhanced to 92.1 MPa from 68.3 MPa for that of RC film because of the strong interfacial interaction between the LDHs and cellulose matrix as well as the high rigidity of the LDHs. The addition of LDH into the cellulose could improve the thermal stability, water resistance, and flame retardant of the regenerated cellulose film. Zn²⁺ ions were exited in the cellulose/ZnAl-LDH materials, leading to good antibacterial activities against Staphylococcus aureus and Escherichia coli, which is important for RCL composite materials in antibacterial packaging filed.     

Development of Phosphodiesterase–Protein-Kinase Complexes as Novel Targets for Discovery of Inhibitors with Enhanced Specificity

Phosphodiesterases (PDEs) hydrolyze cyclic nucleotides to modulate multiple signaling events in cells. PDEs are recognized to actively associate with cyclic nucleotide receptors (protein kinases, PKs) in larger macromolecular assemblies referred to as signalosomes. Complexation of PDEs with PKs generates an expanded active site that enhances PDE activity. This facilitates signalosome-associated PDEs to preferentially catalyze active hydrolysis of cyclic nucleotides bound to PKs and aid in signal termination. PDEs are important drug targets, and current strategies for inhibitor discovery are based entirely on targeting conserved PDE catalytic domains. This often results in inhibitors with cross-reactivity amongst closely related PDEs and attendant unwanted side effects. Here, our approach targeted PDE–PK complexes as they would occur in signalosomes, thereby offering greater specificity. Our developed fluorescence polarization assay was adapted to identify inhibitors that block cyclic nucleotide pockets in PDE–PK complexes in one mode and disrupt protein-protein interactions between PDEs and PKs in a second mode. We tested this approach with three different systems—cAMP-specific PDE8–PKAR, cGMP-specific PDE5–PKG, and dual-specificity RegA–R_D complexes—and ranked inhibitors according to their inhibition potency. Targeting PDE–PK complexes offers biochemical tools for describing the exquisite specificity of cyclic nucleotide signaling networks in cells.     

Oil Demand and Stocks

Current data of world oil demand. This includes international bunkers and refinery fuel. Updated on a monthly basis. Current data of oil demand from counties such as Canada, the United States of America, Japan, OECD Europe, Belgium, France, Germany, Italy, Netherlands, Spain, Sweden, the United Kingdom, Australia, Mexico, Republic of Korea, and Turkey. Updated on a monthly basis. Current data for crude oil and refined product stocks in Canada, Chile, Mexico, the United States (Western Hemisphere), France, Germany, Italy, Netherlands, Spain, the United Kingdom and Other Europe (Europe), Japan, Republic of Korea, Other Pacific (Asia‐Pacific), and Total OECD (Table 12.1) Current data for refined product stocks in the OECD Western Hemisphere, OECD Europe, OECD Asia‐Pacific and Total OECD. Products include gasoline, diesel and gasoil, and heavy fuel oil. Updated on a monthly basis (Table 12.2).     

Phosphorylated cellulose/electrospun chitosan nanofibers media for removal of heavy metals from aqueous solutions

Contamination of water resources by toxic heavy metals has significant impacts on environmental and human health. Their removal from aqueous media is essential to ensure water sustainability and to provide safe freshwater availability to population. Electrospun chitosan (CS) nonwoven mats are efficient at removing heavy metals from aqueous media. However, they suffer from low permeability and low-mechanical strength. They are also unable to remove contaminants in a nonselective way. A bilayer sorbent media made of a porous phosphorylated cellulose substrate covered by electrospun CS nanofibers was developed to overcome those weaknesses. The hydrophilic composite shows good water permeability and mechanical strength with appropriate thermal and chemical characteristics. Adsorption tests with Cd(II) indicate that pseudo-second order and Langmuir models best fitted experimental data, with a maximum adsorption capacity of 591 mg/g at 25°C. Adsorption with multielement samples containing Cr(VI), Cu(II), Cd(II), and Pb(II) also reveal their capability to remove them in a selective way. This mechanically resistant, hydrophilic, and permeable adsorbent media was able to capture both cationic and anionic metallic contaminants.     

样品前处理QuEChERS法及新型吸附材料在水产品中抗生素残留分析中的应用进展

抗生素的不合理使用，给水产品带来了一系列的潜在食用安全风险。品种繁多且残留痕量的抗生素也为食品安全检测带来了新的挑战，发展准确、快速、简便、高效且安全的前处理方法尤为重要。QuEChERS法作为一种新型样品前处理技术，现已逐渐应用到水产品抗生素残留检测中，并可实现较好的回收率。由于水产品中蛋白质和脂类含量高，样品基质复杂，使用经典QuEChERS法无法满足抗生素分析需求，改良其提取方法和净化方法是保证分析结果的关键。本文综述QuEChERS法原理特点，总结归纳其在针对水产品抗生素分析上的主要方法改良手段，并就近十年来改良QuEChERS法在水产品抗生素残留分析中的应用进行文献归纳，同时介绍新型吸附材料在该领域的使用，为探索新的净化方式提供参考，以期帮助检测人员持续优化改进QuEChERS法，推动和扩大QuEChERS法在水产品抗生素残留分析中的应用范围。     

Knowledge‐Based Conceptual Synthesis of Industrial‐Scale Downstream Processes for Biochemical Products

A generic, knowledge‐based guideline assisting downstream process synthesis for biochemical products is presented. It offers process designers a structured process design methodology supporting them in capturing potentially relevant information, which might be beyond their expertise. The guideline is based on heuristic knowledge which was collected, structured in a generic way, and clearly represented. The generation of alternative downstream routes as starting points for experiments, simulation, and cost calculation is hereby accelerated. The application of the guideline is demonstrated on the example of penicillin V downstream processing from fermentation broth.     

Traceability of 9 Portuguese cattle breeds with PDO products in the market using microsatellites

Assignment tests based on multilocus genotypes are becoming increasingly important to certify the origin of livestock products and assure food safety and authenticity. The potential of microsatellites for determining the origin of beef products among cattle breeds present in the Portuguese market with the Protected Denomination of Origin (PDO) was studied. Methodologies were used to establish the number of populations under study and to allocate individuals to their original population. The STRUCTURE program was used to perform the strictly Bayesian method and the GENECLASS 2 program was used to accomplish two types of assignment tests. The STRUCTURE program converged to 9 populations, precisely the number of populations under study. Regarding the individual allocation, the strictly Bayesian method implemented by the STRUCTURE program allowed 96% of correct allocations when running the program without the knowledge of the source populations and 98% when the STRUCTURE program was run knowing the source populations of the animals. In the assignment test performed by the GENECLASS 2, 95% and 97% of individuals were correctly allocated by the frequency and the Bayesian methods, respectively. These results show the potential feasibility for traceability scheme based on microsatellites.     

零能耗太阳能住宅的工业化建造

当前建筑业正处于向工业化发展转型的重要时期,以中国国际太阳能十项全能竞赛(SD 2013)中的北京交通大学"i-Yard"参赛作品为例,重点从建筑部品系统的划分和工业化建造等方面进行解析,为零能耗、可持续建筑的模数化设计和快速工业化生产提供了有益的参考。     

激光共聚焦原位观察水泥早期水化(英文)

采用激光共聚焦显微镜对水泥早期水化过程进行原位观察,样品尺寸为35mm×25mm×5mm的水泥压实体,通过滴加水使压实体中的水泥水化。结果表明:压实体的水化对于正常水泥浆体的水化有着很好的参考作用;压实体样品与水接触8h,表面生成大量的水化产物,水化16h,大部分孔洞被水化产物填充,水化1d,水泥水化到达稳定期,微结构逐渐变密实。     

Improvement in impact strength of modified cardanol‐bonded cellulose thermoplastic resin by adding modified silicones

The impact strength of cellulose diacetate (CDA) bonded with a modified cardanol (3‐pentadecylphenoxy acetic acid: PAA) was greatly improved up to 9 kJ/m² by adding a relatively small amount of modified silicones while suppressing a decrease in bending strength. In our recent research, this thermoplastic resin (PAA‐bonded CDA) exhibited high rigidity, glass transition temperature, and water resistance. However, its impact strength was insufficient for use in durable products. Therefore, silicones modified with polyether, amino, and epoxy groups were investigated as possible ways to improve the impact strength. The results show that adding polyether‐modified silicone (polyether silicone) with moderate polarity relative to PAA‐bonded CDA resulted in shearing deformation greatly enhances its impact strength while maintaining other properties, including glass transition temperature (T_g), water resistance, and thermoplasticity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40366.