ABCG5/G8 Deficiency in Mice Reduces Dietary Triacylglycerol and Cholesterol Transport into the Lymph

The adenosine triphosphate‐binding cassette (ABC) transporter G5/G8 is critical in protecting the body from accumulating dietary plant sterols. Expressed in the liver and small intestine, it transports plant sterols into the biliary and intestinal lumens, thus promoting their excretion. The extent to which G5/G8 regulates cholesterol absorption remains unclear. G5/G8 is also implicated in reducing the absorption of dietary triacylglycerols (TAG) by unknown mechanisms. We hypothesized that G5/G8 suppresses the production of chylomicrons, and its deficiency would enhance the absorption of both dietary TAG and cholesterol. The aim of this study was to investigate the effects of G5/G8 deficiency on lipid uptake and secretion into the lymph under steady‐state conditions. Surprisingly, compared with wild‐type mice (WT) (n = 9), G5/G8 KO (n = 13) lymph fistula mice given a continuous intraduodenal infusion of [3H]‐TAG and [14C]‐cholesterol showed a significant (P < 0.05) reduction in lymphatic transport of both [³H]‐TAG and [¹⁴C]‐cholesterol, concomitant with a significant (P < 0.05) increase of [³H]‐TAG and [¹⁴C]‐cholesterol accumulated in the intestinal lumen. There was no difference in the total amount of radiolabeled lipids retained in the intestinal mucosa between the two groups. G5/G8 KO mice given a bolus of TAG showed reduced intestinal TAG secretion compared with WT, suggesting an independent role for G5/G8 in facilitating intestinal TAG transport. Our data demonstrate that G5/G8 deficiency reduces the uptake and secretion of both dietary TAG and cholesterol by the intestine, suggesting a novel role for the sterol transporter in the formation and secretion of chylomicrons.     

干污泥表面形貌及孔隙分布规律

污泥干燥焚烧以回收其热能的资源化利用正受到越来越多的关注。污泥干燥过程中,孔隙的大小及其分布直接影响污泥中液体及气体的传递过程．进而影响干燥速率。为研究干污泥表面形貌及孔隙分布规律,采用扫描电子显微镜观测了干污泥表面形貌。利用动态氮吸附法测量了干污泥的孔隙大小。利用数理统计方法研究了孔隙分布规律,研究结果表明干污泥的孔隙分布服从对数正态分布。建立了孔隙分布模型,求解了5种干污泥的孔隙分布特征参数,模型计算值与实际测量值吻合较好,均方根误差小于18．2％,所建立的干污泥孔隙分布模型具有一定的通用性及准确性。     

Sol-gel-derived hydroxyapatite-carbon nanotube/titania coatings on titanium substrates

In this paper, hydroxyapatite-carbon nanotube/titania (HA-CNT/TiO(2)) double layer coatings were successfully developed on titanium (Ti) substrates intended for biomedical applications. A TiO(2) coating was firstly developed by anodization to improve bonding between HA and Ti, and then the layer of HA and CNTs was coated on the surface by the sol-gel process to improve the biocompatibility and mechanical properties of Ti. The surfaces of double layer coatings were uniform and crack-free with a thickness of about 7 μm. The bonding strength of the HA-CNT/TiO(2) coating was higher than that of the pure HA and HA-CNT coatings. Additionally, in vitro cell experiments showed that CNTs promoted the adhesion of preosteoblasts on the HA-CNT/TiO(2) double layer coatings. These unique surfaces combined with the osteoconductive properties of HA exhibited the excellent mechanical properties of CNTs. Therefore, the developed HA-CNT/TiO(2) coatings on Ti substrates might be a promising material for bone replacement.     

Hepatic differentiation of rat mesenchymal stem cells by a small molecule

Mesenchymal stem cells (MSCs) are capable of self-renewal and multilineage differentiation. A periodic acid-Schiff (PAS) stain-based assay was developed to screen for small-molecule inducers of hepatic differentiation of bone marrow MSCs. 2-(4-Bromophenyl)-N-(4-fluorophenyl)-3-propyl-3H-imidazo[4,5-b]pyridin-5-amine (SJA710-6) was identified as a novel small molecule able to induce the differentiation of rat MSCs (rMSCs) toward hepatocyte-like cells in vitro, where rMSCs treated with SJA710-6 have typical morphological and functional characteristics of hepatic cells, including glycogen storage, urea secretion, uptake of low density lipoprotein (LDL) and expression of hepatocyte-specific genes and proteins. Expression of FoxH1 (FAST1/2) induces the differentiation of rMSCs towards hepatocyte-like cells, suggesting that this gene plays an important role in the hepatic fate specification of rMSCs.     

Morphology-controlled synthesis of ZnO replicas with photonic structures from butterfly (Papilio paris) wing scales for tunable optical properties

ZnO replicas with photonic structures were fabricated from Papilio paris butterfly wing scales and their tunable optical properties were studied. Through modification of the fabrication method, the reticular porous network structure was successfully replicated from dark black (DB) wing scales. The DB wing scale replicas exhibit a photonic band gap (PBG) in the visible region, which overlaps with the visible emission range of ZnO. Both DB and GB (greenish-blue) wing scale replicas can work as one-dimensional diffraction gratings in optical diffraction experiments, whose spot distances can be tuned by different periodic sizes of butterfly wing structure. Moreover, the ZnO DB wing scale replicas exhibit improved photoluminescence (PL) spectra with reduced visible emission and enhanced UV emission, which can both be attributed to the existence of a PBG produced by the reticular porous network structure in DB wing scales. These results can be very helpful in the research of applications of ZnO materials in UV lasing and optical diffraction devices.     

A magnetically separable photocatalyst based on nest-like γ-Fe₂O₃/ZnO double-shelled hollow structures with enhanced photocatalytic activity

Magnetic nest-like γ-Fe(2)O(3)/ZnO double-shelled hollow nanostructures have been successfully synthesized via a multi-step process. The materials have been thoroughly characterized by different techniques. These interesting nest-like hollow nanostructures are composed of ZnO nanoflakes grown on the surface of γ-Fe(2)O(3) hollow spheres. Importantly, these magnetic hollow nanostructures show very high visible-light photocatalytic activity for the degradation of different organic dyes including methylene blue (MB), Rhodamine-B (RhB), and methyl orange (MO). It is further demonstrated that these γ-Fe(2)O(3)/ZnO hybrid photocatalysts are highly stable and can be used repeatedly.     

等离子S—N—C共渗

本文介绍在研制的多功能离子轰击炉中进行38CrMoAl,W18Cr4V。钢试样的离子S—N—C共渗工艺。通过金相、硬度、X射线结构分析等测试方法,讨论了用H_2,N_2,CS_2挥发气作为共渗介质时的最佳工艺参数。结果表明;在550±10℃,(N_2 H_2)/CS_2=20/l,共渗时间为2.5小时,共渗效果最佳。     

Metastable Phase Selection and Partitioning in ZrO2—MgO Processed from Liquid Precursors

Aqueous mixtures of either zirconium acetate or zirconium nitrate and magnesium nitrate were dried and subsequently pyrolyzed at fast heating rates (upquenching) to form metastable crystalline phases of ZrO₂ with various degrees of MgO supersaturation. The crystallization temperature was determined to be 380°C for the zirconium acetate, and 270°C for the zirconium nitrate at a heating rate of 5°C/min. The crystalline structures were characterized as a function of MgO content and thermal history for specimens containing 0 to 30 mol% MgO. Upquenching to 900°C, where monoclinic ( m ) ZrO₂ and MgO are the equilibrium phases, yielded single-phase tetragonal ( t ) ZrO₂ (<8 mol% MgO), single-phase cubic ( c ) ZrO₂ (9 to 17 mol% MgO), and two-phase c -ZrO₂+ MgO structures (>17 mol% MgO). The composition for which T ₀( t/c ) = 900°C was estimated as 9 ± 1 mol% MgO. Compositions crystallizing as metastable t -ZrO₂ (<8 mol% MgO) partitioned at higher temperatures and/or longer times into two-phase mixtures, following the general sequence t → t + m → m + MgO. Similarly, compositions forming metastable c -ZrO₂ (10 to 30 mol% MgO) partitioned in the following sequence: c → c + t + MgO → t + MgO → t + m + Mgo → m + Mgo. The initial phase selection and subsequent partitioning sequence are discussed in light of phase hierarchies predicted from thermodynamic concepts and kinetic constraints which are introduced by the solute partitioning required to achieve equilibrium.     

草酸铅化废水处理工艺研究

采用不同沉淀剂对草酸铅化废水进行平行沉淀试验,表明在满足除铅效果前提下,以Ca(OH)2与Na2S为沉淀剂处理该废水可改善沉淀物的沉降和过滤性能。提出了处理工艺流程以及pH值控制范围。工程实践表明：废水总铅质量浓度由20～40mg／L降至0.38～1.84mg／L,铅去除率高于90％,排水达标率91．7％～100％,明显改善了纳污水体环境质量。     

解决汽车蓄电池槽注塑包模的方法

汽车蓄电池槽注塑生产过程中经常出现包模。为了防止包模,分析了整个生产过程中出现的问题,并对蓄电池槽设计、模具制造、成型工艺等方面提出预防和整改措施。经生产实践验证,预防和整改措施能解决蓄电池槽生产中的包模。