Recent advances on bioprinting of hydrogels containing carbon materials

The intrinsic properties and versatility of carbon materials (CMs) have recently raised a growing interest in their combination with hydrogels towards the development of advanced materials for biomedical applications. The increasing demand for biomimetic constructs that closely mimic the intricate composition and structure of native tissues has boosted the interest in using three-dimensional (3D) bioprinting technologies for the processing of CMs-containing hydrogels into specialized and more complex constructs capable of steering cell behavior. This review summarizes the progress on the bioprinting of 3D hydrogels containing CMs, focusing on the role of CMs on biomaterial ink design and their impact on both the printing process and the biological function of fabricated constructs. Recent findings demonstrate that CMs are versatile materials that have been mostly used to (1) tune the rheological properties of biomaterial inks, (2) improve the mechanical properties of hydrogels, and/or (3) confer new physical features to hydrogels, such as shape memory, roughness, and thermal and electrical conductivity, which have been shown to modulate the biological response of bioprinted constructs.     

Bioassay-guided fractionation of a hepatoprotective and antioxidant extract of pea by-product

The hepatoprotective and antioxidant activities of the hydroalcoholic extract (PE) of pea (Pisum sativum L.) by-product were evaluated, using CCl4-induced oxidative stress and hepatic damage in rats. These activities were assessed via measuring alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein and albumin, malondialdehyde (MDA), reduced glutathione (GSH), protein thiols (PSH), nitrite/nitrate levels, glutathione-peroxidase (GSH-Px), glutathione-S-transferase (GST) activities, as well as, histopathological evaluation. PE revealed significant hepatoprotective and antioxidant activities mostly found in n-butanol fraction. Chromatographic fractionation of this active fraction led to the isolation of five flavonoid glycosides namely, quercetin-3-O-sophorotrioside (1), quercetin-3-O-rutinoside (2), quercetin-3-O-(6″″-O-E sinapoyl)-sophorotrioside (3), quercetin-3-O-(6″″-O-E feruloyl)-sophorotrioside (4) and quercetin-3-O-β-D-glucopyranoside (5). The isolated compounds were quantified in PE, using a validated HPLC method and the nutritional composition of pea by-product was also investigated. Our results suggest that pea by-product contained biologically active constituents which can be utilised to obtain high value added products for nutraceutical use.     

Na-W-Mn/SiO2催化剂表面甲烷脉冲反应Ⅱ. 多组分Na、 W、 Mn/SiO2催化剂

制备了多组分Na,W,Mn/SiO2催化剂,在ITD（Ion Trap Detector)装置上进行了催化剂表面晶格氧脱附前后的甲烷恒温脉冲反应（CH4－CTPR）。研究结果表明,Na-W/SiO2催化剂表面晶格氧,具有较高的CH4转化率和C2烃选择性,并对C2H6的生成起着重要的作用,Na-Mn/SiO2催化剂表面晶格氧,也具有较高的CH4转化率和C2烃选择性,但对C2H6的形成有一定的诱导期;W－Mn/SiO2催化剂表面晶格氧,对CH4的转化和CO2的生成具有很高初活性,但对C2烃的选择性较低;Na-W-Mn/SiO2催化剂表面晶格氧,具有很高的CH4转化率和C2烃定向选择性,这是由于Na,W,Mn各组分协同作用的结果。     

Na-W-Mn/SiO_2催化剂活化甲烷的研究 Ⅰ.活性中心的结构

制备了不同 Na、W、Mn组分的 Na- W- Mn/ Si O2 催化剂 ,并进行了甲烷氧化偶联反应催化性能的评价和XPS、XRD、L RS表征 .研究结果表明 ,Na不但有强的表面富集能力 ,而且可以使 Mn向表面发生迁移 .首次发现 Na2 W2 O7也是活化甲烷的活性相 .活化甲烷的活性中心是 Na- O- Mn和 Na- O- W结构单元 ,且 Na- O-Mn主要存在于催化剂的表面 ,Na- O- W则分布在距催化剂表面较深的部位     

Vereinfachung der 1H- und 13C-NMR-spektren von benzylether-blockierten sacchariden. Eine leistungsfähige synthese von brommethyl-d2-benzol

An efficient synthesis of bromomethyl-d₂-benzene as reagent for protection of hydroxyl groups and its benefit in ¹H- and ¹³C-NMR-spectroscopical analysis of benzylether blocked saccharides is described.     

异丁烷催化脱氢制异丁烯Cr2O3／Al2O3体系催化剂

对异丁烷催化脱氢催化剂进行了研究。助催化剂Ｋ２Ｏ,ＣｕＯ的引入改进了Ｃｒ２Ｏ３／Ａｌ２Ｏ３催化剂的活性和抗积炭性能。同时考察了原料气空速、反应温度以及催化剂制备的焙烧温度对Ｋ２Ｏ－ＣｕＯ－Ｃｒ２Ｏ３／Ａｌ２Ｏ３催化剂反应性能的影响。ＸＲＤ谱图表明,Ｃｒ２Ｏ３在催化剂中高分散,７００℃焙烧的催化剂中出现的ＫＣｕＯ晶相对催化剂活性不利。用ＮＨ３－ＴＰＤ和ＣＯ２－ＴＰＤ检测了催化剂表面的酸碱中心,表明助     

Controlled optical photonic crystal AND gate using nematic liquid crystal layers

Two optical AND gates built in 2D photonic crystal (PhC) platform have been proposed and numerically simulated using 2D finite element method (FEM). The suggested logic gates consist of five PhC waveguides and silicon annular ring resonator filled by nematic liquid crystal (NLC) of type E7. The first proposed AND gate can handle two inputs and support two operating wavelengths, λ = 1.5 and 1.55 µm. However, the second proposed AND gate can handle three inputs at λ = 1.5 µm. The reported logic gates offer high and low transmission levels with a threshold of 0.5 and an ultra-high bit rate of not less than 0.3 Tbits/s. Further, the suggested AND gates operation can be switched off by using the NLC layer.     

Regiocontrolled preparation of 3-acyl-6-aryl-2-pyridones via condensation of 3-aryl-3-chloropropeniminium salts with β-keto-amides

Α series of substituted 3-acyl-6-aryl-2-pyridones have been prepared in one-step reactions via condensation of 3-aryl-3-chloropropeniminium salts with β-keto-amides. This efficient synthesis has the advantages of high yields and simple reaction procedures.