稻杆的热溶剂提质及多级分离

采用1-甲基萘(1-MN)为溶剂,在不同温度下(250、300、350 ℃)对稻秆进行热溶剂提质及多级分离,获得3种主要固体产物:低分子量萃取物(soluble)、高分子量萃取物(deposit)和萃取残渣(residue),以及少量气体产物和液体产物。对各组分的元素组成、化学结构、物理化学特性等进行了详细分析,并采用ICP-MS测定了其碱金属和碱土金属(AAEM)含量。结果发现,低分子量萃取物收率随着温度的升高而增大,350 ℃时碳基收率达到33.48%。3种固体产物的碳含量和氧含量随着温度的升高而分别升高和降低,350 ℃时soluble、deposit的碳含量分别高达82.36%、80.59%,氧含量分别低至9.50%、12.03%,稻杆原样中高达86.99%的氧以H₂O或CO₂的形式释放。soluble几乎无灰,deposit的灰含量也低于1.50%。3种固体产物的高位发热量显著高于稻杆原样。FT-IR结果表明,稻杆热溶剂处理过程中除发生了脱水反应、脱羧基反应外,还有明显的芳香化反应。soluble和deposit的Na、Mg和K含量极低,而且随温度的升高其含量逐渐降低。总之,热溶剂提质及多级分离法实现了温和条件下的生物质脱水脱氧提质,并获得低灰低氧含量、高碳含量和发热量的多种产物,此方法有较好的应用前景。     

Use of Crude Glycerol as Sole Carbon Source for Microbial Lipid Production by Oleaginous Yeasts

Polyphenols of plant origin with wide range of antiradical activity can prevent diseases caused by oxidative and inflammatory processes. In this study, we show using ESR method that the purified water-soluble extract from leaves of Rhus typhina L. containing hydrolysable tannins and its main component, 3,6-bis-O-di-O-galloyl-1,2,4-tri-O-galloyl-β-d-glucose (C₅₅H₄₀O₃₄), displayed a strong antiradical activity against the synthetic 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) in homogenous (solution) and heterogeneous systems (suspension of DPPH containing liposomes) in the range of 1–10 μg/ml. The C₅₅H₄₀O₃₄ and extract at 1–30 μg/ml also efficiently, but to a various degree, decreased reactive oxygen and nitrogen species (RONS) formation induced in erythrocytes by oxidants, following the sequence: tert-butyl hydroperoxide (tBuOOH) > peroxynitrite (ONOO^?) >hypochlorous acid (HClO). The explanation of these differences should be seen in the specificity of scavenging different RONS types. These relationships can be represented for C₅₅H₄₀O₃₄ and the extract by the following order of selectivity: O^.? ₂ ≥ NO· > ·OH > ¹O₂. The extract exerted a more pronounced antiradical effect in reaction with DPPH and ROS in all models of oxidative stress in erythrocytes in comparison with C₅₅H₄₀O₃₄. The redox processes between the extract components and their specificity in relation to RONS can underlie this effect.     

一种反应型染料的合成及其在聚氨酯革染色中的应用

针对传统聚氨酯色浆中色基与聚氨酯结合力弱(分子间力),导致成品革色牢度差、色迁移严重等技术难题,本文设计合成了一种反应型彩色二元醇:在四氢呋喃介质中,控制n(对苯二胺)∶n(乙酸酐)=1.00∶0.95,0~5℃下,用乙酸酐将对苯二胺单酰化反应15 h,得到对氨基乙酰苯胺(产率85%),经重氮化,与过量摩尔分数为5%N-苯基二乙醇胺偶合制得了一种含两个端羟甲基的偶氮化合物4-乙酰基胺基-4'-N,N-二羟乙氨基偶氮苯(产率82%);将其与聚酯二元醇、聚醚二元醇以不同比例混合,与双异氰酸酯预聚、扩链后形成红色聚氨酯树脂色浆,在离型纸上铺展成膜,其断裂增长率443.0%,断裂相对强度125.5 g,色迁移量21.4μg,进口同类产品形成膜后的断裂增长率、断裂相对强度与色迁移量分别为442.2%、125.3 g和29.2μg.合成产品优于同类进口产品。     

Gas-Phase Analysis of the Complex of Fibroblast GrowthFactor 1 with Heparan Sulfate: A Traveling Wave Ion Mobility Spectrometry (TWIMS) and Molecular Modeling Study

Fibroblast growth factors (FGFs) regulate several cellular developmental processes by interacting with cell surface heparan proteoglycans and transmembrane cell surface receptors (FGFR). The interaction of FGF with heparan sulfate (HS) is known to induce protein oligomerization, increase the affinity of FGF towards its receptor FGFR, promoting the formation of the HS–FGF–FGFR signaling complex. Although the role of HS in the signaling pathways is well recognized, the details of FGF oligomerization and formation of the ternary signaling complex are still not clear, with several conflicting models proposed in literature. Here, we examine the effect of size and sulfation pattern of HS upon FGF1 oligomerization, binding stoichiometry and conformational stability, through a combination of ion mobility (IM) and theoretical modeling approaches. Ion mobility-mass spectrometry (IMMS) of FGF1 in the presence of several HS fragments ranging from tetrasaccharide (dp4) to dodecasaccharide (dp12) in length was performed. A comparison of the binding stoichiometry of variably sulfated dp4 HS to FGF1 confirmed the significance of the previously known high-affinity binding motif in FGF1 dimerization, and demonstrated that certain tetrasaccharide-length fragments are also capable of inducing dimerization of FGF1. The degree of oligomerization was found to increase in the presence of dp12 HS, and a general lack of specificity for longer HS was observed. Additionally, collision cross-sections (CCSs) of several FGF1–HS complexes were calculated, and were found to be in close agreement with experimental results. Based on the (CCSs) a number of plausible binding modes of 2:1 and 3:1 FGF1–HS are proposed.

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Visual and photometric determination of histamine using unmodified gold nanoparticles

Microchimica Acta - The authors describe a colorimetric approach for on-site monitoring of histamine based on the use of gold nanoparticles (AuNPs) that have a negatively charged surface due to the...     

Rapid discrimination of slimming capsules based on illegal additives by electronic nose and flash gas chromatography

The discrimination of counterfeit and/or illegally manufactured medicines is an important task in the pharmaceutical industry for pharmaceutical safety. In this study, 22 slimming capsule samples with illegally added sibutramine and phenolphthalein were analyzed by electronic nose and flash gas chromatography. To reveal the difference among the different classes of samples, principal component analysis and linear discriminant analysis were employed to analyze the data acquired from electronic nose and flash gas chromatography, respectively. The samples without illegal additives can be discriminated from the ones with illegal additives by using electronic nose or flash gas chromatography data individually. To improve the performance of classification, a data fusion strategy was applied to integrate the data from electronic nose and flash gas chromatography data into a single model. The results show that the samples with phenolphthalein, sibutramine and both can be classified well by using fused data.     

High-throughput imaging assay of multiple proteins via target-induced DNA assembly and cleavage

This work integrates target-induced DNA assembly and cleavage on a DNA chip to design a versatile imaging strategy as an assay for multiple proteins. The DNA assembly is achieved via immunological recognition to trigger the proximity hybridization for releasing a DNA sequence, which then hybridizes with FITC-DNA1 immobilized on the chip to induce the enzymatic cleavage of DNA1 and thus decrease the signals. The signal readout is performed with both fluorescent imaging of the left FITC and chemiluminescent (CL) imaging, by adding peroxidase labelled anti-FITC in assembly solution and CL substrates to produce CL emission. This one-step incubation can be completed in 30 min. The imaging method shows wide detection ranges and detection limits down to pg mL^–1 for the simultaneous detection of 4 protein biomarkers. This high-throughput strategy with good practicability can be easily extended to other protein analytes, providing a powerful protocol for protein analysis and clinical diagnosis.     

Mild N-deacylation of secondary amides by alkylation with organocerium reagents

Secondary amides are a class of highly stable compounds serving as versatile starting materials, intermediates and directing groups (amido groups) in organic synthesis. The direct deacylation of secondary amides to release amines is an important transformation in organic synthesis. Here, we report a protocol for the deacylation of secondary amides and isolation of amines. The method is based on the activation of amides with Tf₂O, followed by addition of organocerium reagents, and acidic work-up. The reaction proceeded under mild conditions and afforded the corresponding amines, isolated as their hydrochloride salts, in good yields. In combination with the C-H activation functionalization methodology, the method is applicable to the functionalization of aniline as well as conversion of carboxylic derivatives to functionalized ketones.     

EXACT BOUNDARY CONTROLLABILITY OF 1-D NONLINEAR SCHRODINGER EQUATION

In this paper, the boundary control problem of a distributed parameter system described by the Schr(o)dinger equation posed on finite interval α≤ x ≤β:{iyt yxx |y|2y = 0,y(α,t) = h1(t),y(β,t) = h2(t) for t ＞ 0 (S)is considered. It is shown that by choosing appropriate control inputs (hj), (j = 1,2) one can always guide the system (S) from a given initial state ψ∈ Hs(α,β),(s ∈ R) to a terminal state ψ∈ Hs(α,β), in the time period [0, T]. The exact boundary controllability is obtained by considering a related initial value control problem of Schr(o)dinger equation posed on the whole line R. The discovered smoothing properties of Schr(o)dinger equation have played important roles in our approach; this may be the first step to prove the results on boundary controllability of (semi-linear) nonlinear Schr(o)dinger equation.     

Compact, single-frequency all-fiber Q-switched laser at 1 microm

We demonstrate a unique, all-fiber, actively Q-switched laser operating in the 1 microm region. The laser is compact, single mode, single frequency, highly polarized, and exhibits high peak power. The laser cavity is constructed without external coupling, utilizing fiber Bragg gratings that permit feedback at only a single polarization. By using a piezoelectric to press the fiber and modulate the fiber birefringence, the cavity is switched between high and low loss states, permitting Q-switching. We demonstrate this Q-switching at repetition rates up to 700 KHz.