Porous ceramics with tailored pore size and morphology as substrates for coral larval settlement

The growing demand for stony corals as ornamental aquarium animals requires defined aquacultural breeding strategies. For the sexual propagation of corals, material substrates are needed, that attract larvae and support their settlement and development. In this study, five types of highly porous ceramic materials were developed following the example of coral skeleton. The applicability of these settlement substrates was tested using larvae of the stony coral Pocillopora damicornis. Partial sintering of pressed clay pellets, freeze casting of clay and alumina-mullite based slurries and direct foaming of high alkane phase emulsified suspensions (HAPES) using alumina were employed. By the addition of mm-sized spherical polystyrene beads as sacrificial templates during freeze casting (alumina-mullite), superficial pores in the size of the larvae were created. The inorganic substrates featured open porosities between 35% (pressed clay) and 83% (foamed alumina), pore sizes ranging from nm to mm-scale and pore morphologies dominated by interparticle porosity (pressed), lamellar pores (freeze casting) and cellular pore types (direct foaming). The ceramic substrates were incubated in artificial sea water for 3 months to induce necessary biofilm formation and algae growth. Afterwards, individual substrates were exposed to 5 coral larvae, and their settlement behavior was monitored over 14 days. At the end of this period, all ceramic materials were successfully accepted as settlement substrates, with a mean settlement rate of 46.2%, and no significant differences between the substrate types. On samples with large surface superficial pores, a significantly reduced survival of settled larvae (79%) compared to the other porous materials (93–98%) was determined, suggesting a non-ideal surface topography. While alumina foam samples (HAPES) exhibit the most promising results in terms of settlement and survival of larvae, clay-based substrates provide a more economic solution for the sexual propagation of corals in aquaculture.     

Development of a quantitative method for headspace analysis of methylsulfanyl-volatiles from kiwifruit tissue

Minor fruit volatiles are likely to be missed using sampling techniques optimized for the extraction of major compounds. This can be a disadvantage if these minor compounds contribute to characteristic fruit flavors. In this comparative study, headspace solid-phase microextraction (HS-SPME) and dynamic headspace sampling (DHS) parameters were systematically optimized to ensure highest extraction yields of methylsulfanyl-volatiles from kiwifruit tissue samples. A significant “salting-out” effect from the fruit matrix was observed using both sampling techniques after (NH₄)₂SO₄ saturation. HS-SPME at optimized conditions (polydimethylsiloxane-divinylbenzene-coated fiber, (NH₄)₂SO₄ saturation, 5 min equilibration and 20 min sampling at 40 °C) was faster and more convenient to use than DHS for qualitative purposes. Despite this, the qualitative and quantitative methylsulfanyl-volatile profile was improved using optimized DHS ((NH₄)₂SO₄ saturation; sampling time 20 h; flow rate 30 mL min^− 1) compared with HS-SPME, making this the more sensitive and preferred method for quantitative studies. The optimization strategies for increasing headspace extraction yields of trace compounds presented in this study can easily be applied to tissue samples from other fruit.     

Discovery of Adamantyl Ethanone Derivatives as Potent 11β‐Hydroxysteroid Dehydrogenase Type 1 (11β‐HSD1) Inhibitors

11β‐Hydroxysteroid dehydrogenases (11β‐HSDs) are key enzymes regulating the pre‐receptor metabolism of glucocorticoid hormones. The modulation of 11β‐HSD type 1 activity with selective inhibitors has beneficial effects on various conditions including insulin resistance, dyslipidemia and obesity. Inhibition of tissue‐specific glucocorticoid action by regulating 11β‐HSD1 constitutes a promising treatment for metabolic and cardiovascular diseases. A series of novel adamantyl ethanone compounds was identified as potent inhibitors of human 11β‐HSD1. The most active compounds identified ( 52 , 62 , 72 , 92 , 103 and 104 ) display potent inhibition of 11β‐HSD1 with IC₅₀ values in the 50–70 nM range. Compound 72 also proved to be metabolically stable when incubated with human liver microsomes. Furthermore, compound 72 showed very weak inhibitory activity for human cytochrome P450 enzymes and is therefore a candidate for in vivo studies. Comparison of the publicly available X‐ray crystal structures of human 11β‐HSD1 led to docking studies of the potent compounds, revealing how these molecules may interact with the enzyme and cofactor.     

基于局部不变特征的直方图相关匹配方法

将一种基于局部不变的特征描述符ARPIH(Angular Radial Partitioning Inten-sity Histogram)与直方图相关性判断结合起来,提出了一种新的图像匹配算法。本方法保留了ARPIH描述的优点,在匹配旋转、亮度变化、透视等畸变图像时显示出了鲁棒性。通过求取模板图像和目标图像的两个描述直方图间的相似点的个数进行相似性匹配,提高了匹配精度。     

新型橡胶硫化促进剂HSD在氯磺化聚乙烯橡胶中的应用

对硫化促进剂HSD和DPTT在氯磺化聚乙烯橡胶中作性能对比,证实HSD有比较好的耐焦烧性能而不影响硫化。     

11βHSD1抑制剂1-(4-三氟甲氧基苯甲酰基)-4-(4-甲氧基苯甲酰基)哌啶的合成研究

以4-甲氧羰基哌啶盐酸盐(1)和对三氟甲氧基苯甲酰氯(2)为起始原料,在三乙胺的作用下以92.7%的收率制得1-(4-三氟甲基苯甲酰基)-4-甲氧羰基哌啶(3);化合物(3)在羰基二咪唑与N,O-二甲基羟胺盐酸盐(4)作用下,以89.9%的收率制得1-(4-三氟甲氧基苯甲酰基)-4-(N-甲基-N-甲氧基羰基)哌啶(5);化合物(5)和4-甲氧基苯基溴化镁(6)偶联,以60.1%的收率制得化合物1-(4-三氟甲氧基苯甲酰基)-4-(4-甲氧基苯甲酰基)哌啶(7)。三步反应总收率50.0%。     

新型硫化促进剂HSD在氯磺化聚乙烯中应用

本文介绍了一种新型橡胶硫化促进剂 SHD在氯磺化聚乙烯橡胶中应用 ,可等量代替目前使用的硫化促进剂 DPTT,并获得非常满意的效果     

Dehydroepiandrosterone (DHEA) metabolism in Saccharomyces cerevisiae expressing mammalian steroid hydroxylase CYP7B: Ayr1p and Fox2p display 17beta-hydroxysteroid dehydrogenase activity

We have engineered recombinant yeast to perform stereospecific hydroxylation of dehydroepiandrosterone (DHEA). This mammalian pro-hormone promotes brain and immune function; hydroxylation at the 7alpha position by P450 CYP7B is the major pathway of metabolic activation. We have sought to activate DHEA via yeast expression of rat CYP7B enzyme. Saccharomyces cerevisiae was found to metabolize DHEA by 3beta-acetylation; this was abolished by mutation at atf2. DHEA was also toxic, blocking tryptophan (trp) uptake: prototrophic strains were DHEA-resistant. In TRP(+) atf2 strains DHEA was then converted to androstene-3beta,17beta-diol (A/enediol) by an endogenous 17beta-hydroxysteroid dehydrogenase (17betaHSD). Seven yeast polypeptides similar to human 17betaHSDs were identified: when expressed in yeast, only AYR1 (1-acyl dihydroxyacetone phosphate reductase) increased A/enediol accumulation, while the hydroxyacyl-CoA dehydrogenase Fox2p, highly homologous to human 17betaHSD4, oxidized A/enediol to DHEA. The presence of endogenous yeast enzymes metabolizing steroids may relate to fungal pathogenesis. Disruption of AYR1 eliminated reductive 17betaHSD activity, and expression of CYP7B on the combination background (atf2, ayr1, TRP(+)) permitted efficient (>98%) bioconversion of DHEA to 7alpha-hydroxyDHEA, a product of potential medical utility.     

HSD三叶异形涤纶的研制

介绍了在ＨＳＤ三热辊超高速纺丝一步法设备上以５２００ｍ／ｍｉｎ的超高速纺技术生产异形涤纶系列产品的探索性试验，并工业化大批量生产了８３．３ｄｔｅｘ／３６ｆ三叶异形丝。生产实践证明适当提高熔体温度，缓和侧吹风风速，减少卷绕张力，调整拉伸倍数等工艺，能生产出优质的三叶异形丝。