The Research on Sino-US Green Building Rating System

AbstractThis paper describes the more commonly used domestic and international green building rating systems and details of the evaluation of U.S. LEED, its old and new versions, the trend of improvement in LEED; Compared Chinese “Evaluation Standard for Green Building” (GB/T 50378-2006)with the LEED2009, the paper points out their shortcomings, and identify the existing differences between them. Then comes out the conclusion that LEED2009 is still target to the U.S. buildings, Chinese engineers should learn from its advantage, make use in our evaluation of green building, which is suitable for China's actual conditions. But we make full use of Chinese buildings of the LEED rating system is not appropriate. Finally, we make a suggestion for “Evaluation Standard for Green Building” that we should add incentives for new energy sources can effectively develop our new energy, give a positive role in environment protection

Popping the soap bubble: Bile acids as postrandial signal

Bile acids are not merely soaps to aid lipid absorption but also function as signaling molecules in glucose, lipid, and their own metabolism. Bile acids are synthesized in the liver, stored in the gallbladder and released into the small intestines after food intake. Most of the bile acids are reabsorbed from the intestines and travel back to the liver. This is called the enterohepatic circulation. A small percentage of the total bile acid pool escapes hepatic clearance and, therefore, bile acids are also present in the systemic circulation. After food intake (“postprandial”) the concentration of bile acid rises. There are various receptors that can bind bile acids, the ones involved in energy metabolism and described in this thesis are the farnesoid X receptor (FXR) and the Takeda G protein-coupled receptor 5 (TGR5). FXR and TGR5 are highly expressed within the enterohepatic circulation, but also outside, for example in adipose tissue and the brain. Therefore, the notion emerged that circulating bile acids might serve as postprandial messengers through these receptors. We aimed to investigate whether the metabolic effects of bile acids were exerted via the brain. For this purpose, we studied several aspects of bile acid metabolism with regard to postprandial hepatic kinetics, day-night rhythm, food paradigms and effects in the brain

Hydrogels of collagen-inspired telechelic triblock copolymers for the sustained release of proteins

We studied the release of entrapped protein from transient gels made of thermosensitive, collagen-inspired ABA triblock copolymers with tailorable properties and with mid blocks of two different lengths (~ 37 kDa and ~ 73 kDa). These polymers were produced as heterologous proteins in recombinant yeast. By varying polymer length and concentration, the elastic properties of the hydrogels as well as their mesh size, swelling and erosion could be tuned. Whereas the volume of the investigated dense networks decreased in time as a result of temperature- and polymer concentration-dependent surface erosion, the release of entrapped protein was governed by a combination of gel erosion and protein diffusion. The prevalence of one or the other was strongly dependent on polymer concentration. Most importantly, the encapsulated protein was quantitatively released, which demonstrates that these hydrogels offer great potential as drug delivery systems

Secreted production of collagen-inspired gel-forming polymers with high thermal stability in Pichia pastoris

Previously, we have shown that gel-forming triblock proteins, consisting of random coil middle blocks and trimer-forming (Pro-Gly-Pro)(9) end blocks, are efficiently produced and secreted by the yeast Pichia pastoris. These end blocks had a melting temperature (T (m) ) of ~41°C (at 1.1¿mM of protein). The present work reveals that an increase of T (m) to ~74°C, obtained by extension of the end blocks to (Pro-Gly-Pro)(16) , resulted in a five times lower yield and partial endoproteolytic degradation of the protein. A possible cause could be that the higher thermostability of the longer (Pro-Gly-Pro)(16) trimers leads to a higher incidence of trimers in the cell, and that this disturbs secretion of the protein. Alternatively, the increased length of the proline-rich (Pro-Gly-Pro)( n ) domain may negatively influence ribosomal translation, or may result in, for example, hydrophobic aggregation or membrane-active behavior owing to the greater number of closely placed proline residues. To discriminate between these possibilities, we studied the production of molecules with randomized end blocks that are unable to form triple helices. The codon- and amino acid composition of the genes and proteins, respectively, remained unchanged. As these nontrimerizing molecules were secreted intact and at high yield, we conclude that the impaired secretion and partial degradation of the triblock with (Pro-Gly-Pro)(16) end blocks was triggered by the occurrence of intracellular triple helices. This degradation was overcome by using a yapsin 1 protease disruptant, and the intact secreted polymer was capable of forming self-supporting gels of high thermal stability

Influence of molecular size on gel-forming properties of telechelic collagen-inspired polymers

We studied the influence of molecular size on the formation of transient networks by telechelic protein polymers with 2.3 kDa collagen-like triple helix-forming end-blocks and much longer random coil mid-blocks. We compared triblock copolymers with mid-blocks of 400 and 800 amino acids (37 and 73 kDa, respectively) and two different amino acid sequences, all of which were secreted to high concentration by recombinant yeast cells. At the same molar concentration of protein and crosslink-forming end-blocks, the storage modulus of the longer polymers was higher than that of the shorter polymers. Differences in storage modulus values were also observed for the polymers with mid-blocks of the same amino acid composition but different amino sequence, which correlated to differences in the measured hydrodynamic radius of the mid-blocks. The melting temperature of the triple helices was the same for both larger and smaller polymers; however, the elastic properties of the gels were lost at lower temperature for the smaller polymers than for the larger polymers. Using an analytical model based on classical gel theory and accounting for the well-defined multiplicity of the network, we could ascribe these differences to the lower probability of the longer chains to form intramolecular loops

Precision gels from collagen-inspired triblock copolymers

Gelatin hydrogels find broad medical application. The current materials, however, are from animal sources, and their molecular structure and thermal properties cannot be controlled. This study describes recombinant gelatin-like polymers with a general design that inherently offers independent tuning of the cross-link density, melting temperature, and biocompatibility of the gel. The polymers contain small blocks with thermoreversible trimerization capacity and defined melting temperature, separated by hydrophilic nontrimerizing blocks defining the distance between the knot-forming domains. As an example, we report the secreted production in yeast at several g/L of two nonhydroxylated 42 kDa triblock copolymers with terminal trimerizing blocks. Because only the end blocks formed cross-links, the molecular architecture of the gels is much more defined than that of traditional gelatins. The novel hydrogels had a 37 °C melting temperature, and the dynamic elasticity was independent of the thermal history. The concept allows to produce custom-made precision gels for biomedical applications

A multilevel screening strategy defines a molecular fingerprint of proregenerative olfactory ensheathing cells and identifies SCARB2, a protein that improves regenerative sprouting of injured sensory spinal axons

Olfactory ensheathing cells (OECs) have neuro-restorative properties in animal models for spinal cord injury, stroke, and amyotrophic lateral sclerosis. Here we used a multistep screening approach to discover genes specifically contributing to the regeneration-promoting properties of OECs. Microarray screening of the injured olfactory pathway and of cultured OECs identified 102 genes that were subsequently functionally characterized in cocultures of OECs and primary dorsal root ganglion (DRG) neurons. Selective siRNA-mediated knockdown of 16 genes in OECs (ADAMTS1, BM385941, FZD1, GFRA1, LEPRE1, NCAM1, NID2, NRP1, MSLN, RND1, S100A9, SCARB2, SERPINI1, SERPINF1, TGFB2, and VAV1) significantly reduced outgrowth of cocultured DRG neurons, indicating that endogenous expression of these genes in OECs supports neurite extension of DRG neurons. In a gain-of-function screen for 18 genes, six (CX3CL1, FZD1, LEPRE1, S100A9, SCARB2, and SERPINI1) enhanced and one (TIMP2) inhibited neurite growth. The most potent hit in both the loss- and gain-of-function screens was SCARB2, a protein that promotes cholesterol secretion. Transplants of fibroblasts that were genetically modified to overexpress SCARB2 significantly increased the number of regenerating DRG axons that grew toward the center of a spinal cord lesion in rats. We conclude that expression of SCARB2 enhances regenerative sprouting and that SCARB2 contributes to OEC-mediated neuronal repair. © 2013 Asian Network for Scientific Information

Longitudinal sampling is required to maximize detection of intrahost A/H3N2 virus variants

10.1093/ve/veaa088Virus Evolution62veaa08