Analysis of Sequence Divergence in Mammalian ABCGs Predicts a Structural Network of Residues That Underlies Functional Divergence

The five members of the mammalian G subfamily of ATP-binding cassette transporters differ greatly in their substrate specificity. Four members of the subfamily are important in lipid transport and the wide substrate specificity of one of the members, ABCG2, is of significance due to its role in multidrug resistance. To explore the origin of substrate selectivity in members 1, 2, 4, 5 and 8 of this subfamily, we have analysed the differences in conservation between members in a multiple sequence alignment of ABCG sequences from mammals. Mapping sets of residues with similar patterns of conservation onto the resolved 3D structure of ABCG2 reveals possible explanations for differences in function, via a connected network of residues from the cytoplasmic to transmembrane domains. In ABCG2, this network of residues may confer extra conformational flexibility, enabling it to transport a wider array of substrates.     

Operational optimization of a building-level integrated energy system considering additional potential benefits of energy storage

As a key component of an integrated energy system (IES), energy storage can effectively alleviate the problem of the times between energy production and consumption. Exploiting the benefits of energy storage can improve the competitiveness of multi-energy systems. This paper proposes a method for day-ahead operation optimization of a building-level integrated energy system (BIES) considering additional potential benefits of energy storage. Based on the characteristics of peak-shaving and valley-filling of energy storage, and further consideration of the changes in the system’s load and real-time electricity price, a model of additional potential benefits of energy storage is developed. Aiming at the lowest total operating cost, a bi-level optimal operational model for day-ahead operation of BIES is developed. A case analysis of different dispatch strategies verifies that the addition of the proposed battery scheduling strategy improves economic operation. The results demonstrate that the model can exploit energy storage’s potential, further optimize the power output of BIES and reduce the economic cost.     

A comparative study of comminution in rotary and vibratory ball mills

A comparative study of the comminution in rotary and vibratory ball mills using sodium chloride is presented. The many advantages of vibratory over rotary ball milling are outlined and it is shown experimentally that the rate and extent of grinding is higher for the vibratory ball mill. It is further shown that fine particles re-aggregate in the rotary ball mill and ‘cake’ irreversibly. This phenomenon, exclusive to the rotary ball mill, is explained in terms of consolidation and high stress relaxation of the crystals occurring during prolonged grinding.     

Preparation and characterization of surfactant‐free stimuli‐sensitive microgel dispersions

A surfactant‐free method to produce responsive polymer microgels is introduced. As an example, poly(methacrylic acid) hydrogels with varying crosslinking density have been synthesized in bulk and then chopped using a high shear mechanical cutter to form microgel particles dispersed in water. The mechanical cutting technique enables the concentration and particle size distribution of the microgel suspensions to be easily controlled, therefore making the rheology of the suspensions tuneable. The particle size distribution of the dispersions, characterized using light scattering, was dependent on the speed and duration of mechanical cutting. The particle size distribution also depended on the degree of crosslinking of the hydrogel. The higher the crosslinking density, the lower the average mean diameter of the resulting microgel particles. The lower the crosslinking density of the hydrogel, the larger the difference between the maximum and minimum particle size. The time to complete swelling of the particles upon change in pH was measured to be up to 45 s, depending on the particle size. The rheology of the resulting suspensions as a function of pH was investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 104: 1912–1919, 2007     

Dewatering behaviour of water treatment sludges associated with contaminated site remediation in Antarctica

Sludge reduction and dewatering is an important aspect of water and waste water treatment. This is especially true in the case of Australia's Antarctic contaminated site remediation program, where the reduction in volume of wastes to be returned to Australia can lead to significant transport and handling cost savings. The dewatering characterisation of water treatment sludges from an Antarctic contaminated site was conducted using a theory of suspension dewatering developed by Buscall, Landman and White. This theory uses fundamental material properties of compressibility and permeability to determine the diffusivity of a suspension. Diffusivity is a useful property that can be used to directly compare the dewaterability of various sludges. In this investigation, several water treatment sludges were collected and characterised in the field to determine the impact of temperature and additives on compressibility, permeability and diffusivity. The Antarctic sludges were found to be less compressible and less permeable than materials such as mineral suspensions and alum water treatment sludges. Compressibility was found to decrease with the addition of powdered coagulation aids such as bentonite and chitosan.     

Obesity in children – facts and fallacies

Obesity is now recognised as the most prevalent nutritional disorder affecting children. Prevalence rates across Europe have increased sharply in the past decade and the consequences of this are increasingly clear with type 2 diabetes, hyperlipidaemia and hypertension now affecting children in growing numbers. The causes of this modern epidemic are many and involve complex genetic and environmental factors and the traditional view of obesity as a product of laziness and greed is increasingly being challenged. Whatever the causes, prevention and treatment need to be considered with urgency. While personal and parental responsibility remain crucial, it also falls to government to help control powerful environmental pressures which are leading our children into premature ill‐health and mortality. Equally health professionals are increasingly recognising that they have a significant role to play in delivering medical treatment of obesity in children. Successful treatment requires a greater understanding of obesity, causes, and consequences, and of the particular style of approach that is required for children, and their families. The role of weight loss medication remains unclear, but is being examined seriously, such is the need for effective treatment strategies to minimise the incidence and severity of co‐morbid disease. Inaction at any level can no longer be considered a viable option.     

Selective oxidation of styrenes under oxygen catalyzed by cobalt chloride

The cobalt(II) chloride-catalyzed oxidative cleavage of -methylstyrene with oxygen in t-BuOH gives acetophenone and formaldehyde in good yield. The competing reactions between C=C cleavage and formation of polymeric products are strongly affected by the solvent, cobalt catalyst and concentration used, as well as the reaction temperature. A free radical mechanism involving a cyclic peroxide intermediate is proposed to give the cleavage products. Oxidation of various alkenes using CoCl₂/t-BuOH/O₂ system shows that only activated styrenes can be oxidized effectively. The reactivity of various styrenes and their selectivity towards giving cleavage products or polymers are strongly influenced by the electronic and steric properties of the substrate.     

Effects of octadecanoid metabolites and inhibitors on induced nicotine accumulation inNicotiana sylvestris

We examined the effects of inhibitors of the octadecanoid pathway (n-propyl gallate, acetosalicylic acid, salicylhydroxamic acid, methyl salicylate, and antipyrine) on wound- and jasmonate-induced nicotine accumulation and compared the nicotine-inducing ability of exogeneous additions of linolenic acid (18:3) and its methyl ester, linoleic acid (18:2), abscisic acid, traumatic acid, and methyl dihydrojasmonate to the nicotine-inducing ability of exogenous additions of methyl jasmonate (MJ). The first four of these inhibitors significantly reduced wound-induced nicotine accumulation when applied in a lanolin paste to wounded tissues immediately after wounding at concentrations of 89–90µg/plant. When methyl salicylate and propyl gallate were mixed individually with MJ, neither inhibited MJ-induced nicotine synthesis, which suggests that the inhibitors block jasmonate synthesis or release from stored pools and not its effects. Linolenic acid or its methyl ester applied to undamaged plants or damaged plants (to either damaged or undamaged leaves) or to the roots of hydroponically growing plants did not induce nicotine accumulation or increase nicotine accumulation above levels found in damaged plants. Similarly, traumatic acid, linoleic acid, and abscisic acid did not induce nicotine accumulations. Methyl dihydrojasmonate, which is biosynthetically derived from linoleic acid, had 12–56% of the nicotine-inducing acitivity of MJ when added to the roots of hydroponically grown plants. The signal transduction pathway mediating wound-induced nicotine production therefore shares many features of the pathway eliciting wound-induced proteinase inhibitor production but differs in not being regulated at the lipase step in jasmonic acid production and not being responsive to abscisic acid.     

Regressing Local to Global Shape Properties for Online Segmentation and Tracking

We propose a novel regression based framework that uses online learned shape information to reconstruct occluded object contours. Our key insight is to regress the global, coarse, properties of shape from its local properties, i.e. its details. We do this by representing shapes using their 2D discrete cosine transforms and by regressing low frequency from high frequency harmonics. We learn this regression model using Locally Weighted Projection Regression which expedites online, incremental learning. After sufficient observation of a set of unoccluded shapes, the learned model can detect occlusion and recover the full shapes from the occluded ones. We demonstrate the ideas using a level-set based tracking system that provides shape and pose, however, the framework could be embedded in any segmentation-based tracking system. Our experiments demonstrate the efficacy of the method on a variety of objects using both real data and artificial data.     

超临界流体技术在微孔发泡聚合物制备中的应用

介绍了超临界流体技术和微孔聚合物的概念及优点。着重介绍了超临界流体技术在微孔聚合物制备中的应用及发展状况，并简单介绍了制备微孔聚合物的影响因素，最后阐述了对超临界流体技术的展望和建议。