原料米对广东客家黄酒发酵及产γ-氨基丁酸的影响

该文研究不同原料米(糯米、粳米、籼米)对客家黄酒发酵过程中总糖、总酸、氨基酸态氮、γ-氨基丁酸(GABA)含量及谷氨酸脱羧酶(GAD酶)活性的影响。结果表明,在总糖、总酸、氨基酸态氮指标方面,糯米、粳米、籼米都适合酿制客家黄酒,但糯米黄酒、粳米黄酒总糖、总酸和氨基酸态氮含量较高;发酵过程中,GABA含量糯米黄酒最高,粳米黄酒次之,籼米黄酒最低;贮藏一个月后,糯米黄酒GABA含量达到260.45 mg/L,分别为粳米黄酒、籼米黄酒的1.13、1.44倍。糯米、粳米黄酒的GAD酶活性较大且两者接近,而籼米GAD酶活性较小,与糯米、粳米相差较大。综上所述,对比三种原料米,糯米最适合发酵客家黄酒及产GABA,粳米次之,籼米较不利。

椰毒假单胞菌酵米面亚种在湿米粉及其原料中的生长产毒规律及风险分析

采用在湿米粉及其原料米和米浆中分别接入不同浓度(10^(3)、10^(5)和10^(7) cfu/mL)椰毒假单胞菌酵米面亚种(简称“椰毒假单胞菌”),在最佳产毒温度(26℃)和最佳生长温度(36℃)中培养并检测毒素米酵菌酸含量变化等技术,研究分析了椰毒假单胞菌在三种食物基质中的生长产毒规律以及相关风险。结果表明:椰毒假单胞菌产米酵菌酸的量与食物基质中椰毒假单胞菌量呈正相关,与食物性状、含水量等有较大相关性;相同接菌量、培养温度和时间下,湿米粉中米酵菌酸含量高于原料米和米浆(最高约5000多倍);湿米粉和原料米分别接菌105 cfu/mL、26℃和36℃培养,培养48 h时湿米粉中米酵菌酸含量可高达27 mg/kg,风险较高,原料米培养期间(35 d)米酵菌酸含量约在0.7~16μg/kg,风险较低。研究提示应从原料、生产、储运、经营和消费全链条来加强防控湿米粉被椰毒假单胞菌污染产毒。

HPLC法测定醋酸地塞米松原料中的有关物质

目的建立HPLC法测定醋酸地塞米松原料的有关物质。方法采用Diamonsil C18(250 mm×4.6 mm,5μm)色谱柱,流动相:乙腈-水(体积比为40∶60),检测波长:254 nm,流速:1.0 mL·min-1,柱温:30℃,进样量:20μL。结果地塞米松、醋酸倍他米松、杂质A、杂质B、杂质C均在0.01~1.6mg·L-1内线性关系良好,平均回收率为91.0%~98.2%(n=9),RSD≤3.0%。结论醋酸地塞米松和有关物质可有效分离,可更好的控制醋酸地塞米松的质量。

激光散射法测定醋酸地塞米松原料药粒度的方法学研究

目的使用激光粒度分析仪建立醋酸地塞米松原料药粒度的测定方法。方法研究了不同测定参数,包括分散介质、光学参数、超声时间和搅拌速率,对样品平均粒径(Average particle size,APS)的影响。根据所得数据的平均残差(Mean residual,MR)和相对标准偏差(Relative standard deviation,RSD),分析了测定参数对测定结果的影响。结果选择水为分散介质、折射率为1.53、吸收率为0.01、超声时间为1 min、转速为1500 r·min^(-1)时,测定结果具有较小的MR和RSD。结论该方法能够有效测定醋酸地塞米松原料药的粒度。

他米巴罗汀原料药的稳定性考察

目的考察他米巴罗汀原料药的稳定性。方法依据2010年版《中国药典(二部)》附录"原料药与药物制剂稳定性试验指导原则"的有关技术要求,进行稳定性试验,包括影响因素试验、加速试验、长期试验。结果两年考察结果显示,3批样品的熔点、含量、有关物质均无显著变化,外观上稍有吸湿性。结论他米巴罗汀原料药应密闭于阴凉干燥处贮藏,有效期暂定两年。

基于全基因组序列的污染事件中椰毒假单胞菌酵米面亚种溯源分析

目的溯源分析湿米粉与淀粉制品(统称为"湿粉")及其原料米中分离的椰毒假单胞菌酵米面亚种。方法采用GB/T 4789.29—2003《食品安全国家标准食品卫生微生物学检验椰毒假单胞菌酵米面亚种检验》在14份湿粉及其原料米中分离出34株唐菖蒲伯克霍尔德氏菌并进行菌株全基因组重测序,以BurkholderiagladioliCo14作为参比基因,基于单核苷酸多态性(single nucleotide polymorphism,SNP)数据构建进化树,分析不同菌株的同源关系。结果来源于相同产地标识的样品的菌株呈现较好聚类;来源于同一生产企业的湿粉和碎米样品的菌株具有高度同源关系。结论提示原料米中椰毒假单胞菌酵米面亚种的基因组序列与产地溯源具有较大相关性,在湿粉生产加工过程中存在椰毒假单胞菌酵米面亚种污染传递的风险。

日本清酒酿造用米品质要求

日本清酒酿造用米必须高度精白,清酒品质标准越高,原料米精白处理要求也越高。介绍了清酒用米的品质要求及处理方法。（陶然）

Microstructure and mechanism of in-situ Al_2O_(3(p))/Al nano-composites synthesized by sonochemistry melt reaction

The Al2O3（p）/Al nano-composites were fabricated from Al-K2ZrF6-Na2B4O7 system by sonochemistry in situ reaction. The fabrication mechanisms, including high intensity ultrasonic influence on microstructures and reinforcement particles-aluminum matrix interface, were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The XRD results show that the component of the as-prepared composites is Al2O3 reinforcement. The SEM analysis results indicate that Al2O3 particles are uniformly distributed in the aluminum matrix. The TEM results show that the morphologies of Al2O3 particles present in nearly sphere-shape, the sizes are in the range of 20-100 nm, and the interfaces are net and no interfacial outgrowth is observed. Analysis with secondary development Image-J software shows that Al2O3 recoveries are firstly improved and then decreased with increasing ultrasonic power. When the power is 0.4 kW, the distribution is the best, and a maximum number of particles are obtained. The reaction mechanisms were investigated.

Effect of thermal cycle on Ni-Cr based nanostructured thermal spray coating in boiler tubes

Ni-Cr based nanostructured feedstock powder was prepared by mechanical milling technique involving repeated welding, fracturing, and re-welding of powder particles in a planetary ball mill. The milled nanocrystalline powders were used to coat carbon steel tubes using high velocity oxygen fuel（HVOF） thermal spraying process. The characterization of the feedstock powder and HVOF coated substrates was performed using optical microscope, X-ray diffractometer（XRD）, scanning electron microscope（SEM）, high resolution transmission electron microscope（HR-TEM）, energy dispersive spectrometer（EDS） and microhardness tests. The coated and uncoated samples were subjected to different thermal cycles and characterized for their phase changes, metallurgical changes and microhardness variations. Ni-Cr nanostructured coated samples exhibited higher mechanical and metallurgical properties compared to their conventionally coated counter parts. The results showed that the nanostructured coating possessed a more uniform and denser microstructure than the conventional coating.

Recent advances in the rational design of electrocatalysts towards the oxygen reduction reaction

The quest for low‐cost yet efficient non‐Pt electrocatalysts for the oxygen reduction reaction(ORR)has become one of the main focuses of research in the field of catalysis,which has implications for the development of the next generation of greener fuel cells.Here,we comprehensively describe the'big picture'of recent advances made in the rational design of ORR electrocatalysts,including molecule‐based,metal‐oxide‐based,metal‐nanomaterial‐based and two‐dimensional electrocatalysts.Transition metals can fabricate molecular electrocatalysts with N4‐macrocycles such as porphyrin‐class compounds and the so‐formed M-N-C active centre plays a crucial role in determining the catalytic performances towards the ORR.Group‐IV and‐V Transition metal oxides represent another class of promising alternative of Pt‐based catalysts for the ORR which catalytic activity largely depends on the surface structure and the introduction of surface defects.Recent advances in synthesis of metallic nanoparticles(NPs)allow for precise control over particle sizes and shapes and the crystalline facets exposed to enhance the ORR performance of electrocatalysts.Two‐dimensional materials such as functionalized grapheme or MoS2are emerging as novel electrocatalysts for the ORR.This review covers various aspects towards the design of future ORR electrocatalysts,including the catalytic performance,stability,durability and cost.Some novel electrocatalysts even surpass commercial Pt/C systems,demonstrating their potential to be alternatives in industrial applications.Despite the encouraging progress,challenges,which are also described,remain to be overcome before the real‐world application of novel ORR electrocatalysts.

Mn-corrolazine-based 2D-nanocatalytic material with single Mn atoms for catalytic oxidation of alkane to alcohol

Heterogenization of organic-macrocyclic metal catalysts is one of the simplest and most efficient methods for effective separation of products and cyclic application of a catalyst.By using an environmentally friendly Mn-corrolazine catalyst as the building unit,which can directly oxidize organic substrates under oxygen atmosphere and mild conditions,we theoretically constructed a novel two-dimensional(2D)Mn-corrolazine nanocatalytic material with high catalytic activity.In this material,each Mn atom maintains its electronic configuration in the monomer and can directly activate O2 as the single-atom catalyst(SAC)center to form a radical-like[Mn]-O-O under mild visible-light irradiation conditions.The newly generated[Mn]–O–O can efficiently and selectively oxidize C–H bonds to form alcohol species through H-abstraction and the rebound reaction.Moreover,the catalytic reaction is easily regulated by an external electric field along its intrinsic Mn–O–O reaction axis.The current study provides a theoretical foundation for further experimental studies and practical applications of the Mn-corrolazine-based SAC.

Net Energy Ratio and Greenhouse Gas Analysis of a Biogas Power Plant

The results of a net energy life cycle analysis and greenhouse gas analysis for a 1.45 MW （0.71 MW electrical） biogas power plant operating with a 70% corn silage and 30% cow dung feedstock mixture are presented after its initial five years of operation. A ratio of 8.0 for the total output electrical energy divided by the total input energy from fossil fuels is found. A net efficiency of 1.2% of converting solar energy into electricity and usable heat （0.6% electricity） is achieved. Only 16 g CO2 per kWh are generated in the process. If all greenhouse gases are considered, this process even actively reduces the total greenhouse gas load on the atmosphere. In terms of producing transportation biofuels, this process provides 3.8 times more yield per hectare than bioethanol generation.

Therapeutic and Immunomodulatory Effects of Raw Maize ＂OGI＂ on Rats Infected with Escherichia coil 0157：H7

Escherichia coli O157：H7 is known to cause food borne illness globally. Treatment of infections caused by this organism is difficult because the administration of antibiotics might precipitate kidney complications; therefore there is the need to search for alternative therapy. In this study, the therapeutic and immunomodulatory effects of raw maize ＂ogi＂ was investigated on rats infected with Escherichia coli 0157：H7. Infected rats treated with maize ＂ogi＂ slurry 1.0 mL once or twice daily and maize ＂ogi＂ liquor, 1.0 mL twice daily recovered 72 h while those that were treated with less than 1.0 mL recovered by 96 h. Without treatment with ＂ogi＂ however, the rats started recovering by 120 h. The treatment caused the white blood cells which had already gone up as a result of the infection to reduce significantly （P 〈 0.05） by 24 h of administration of raw fermented maize ＂ogi＂ components to the infected rats. It also caused a significant decrease in the lymphocyte counts of the infected and treated rats by 24 h. On the other hand, there was an increase in the neutrophil count irrespective of the different volumes and different components of raw ＂ogi＂ used by 24 h but by the 72 h of treatment, it started to decrease and by 120 h reduced to normal levels. Since the administration of raw maize ＂ogi＂ either slurry or liquor caused the duration of infection in rats infected with Escherichia coli 0157：H7 to reduce from 120 h to 72 h, it is therefore suggested that people having diarrhoea caused by this organism could drink fermented raw maize ＂ogi＂ slurry or liquor to treat the infection.

Preparation of graphene/MgCl_2-supported Ti-based Ziegler-Natta catalysts by the coagglomeration method and their application in ethylene polymerization

We report a facile coagglomeration method for preparing graphene (G)/MgCl2‐supported Ti‐based Ziegler‐Natta catalysts. The effects of graphene feed ratio on catalyst morphology and ethylene polymerization behavior were examined. The synthesized catalyst exhibited very high activity for ethylene polymerization. The resultant polyethylene (PE)/G nanocomposites showed a layered morphology, and the graphene fillers were well dispersed in the PE matrix. In addition, the thermal stability and mechanical properties of PE were significantly enhanced with the introduction of a very small amount of G fillers (0.05 wt%). This work provides a facile approach to the production o fhigh‐performance PE.

Nitrogen‐doped graphene aerogel‐supported ruthenium nanocrystals for pH‐universal hydrogen evolution reaction

The design and synthesis of high‐performance and low‐cost electrocatalysts for the hydrogen evolution reaction(HER),a key half‐reaction in water electrolysis,are essential.Owing to their modest hydrogen adsorption energy,ruthenium(Ru)‐based nanomaterials are considered outstanding candidates to replace the expensive platinum(Pt)‐based HER electrocatalysts.In this study,we developed an adsorption‐pyrolysis method to construct nitrogen(N)‐doped graphene aerogel(N‐GA)‐supported ultrafine Ru nanocrystal(Ru‐NC)nanocomposites(Ru‐NCs/N‐GA).The particle size of the Ru‐NCs and the conductivity of the N‐GA substrate can be controlled by varying the pyrolysis temperature.Optimal experiments reveal revealed that 10 wt%Ru‐NCs/N‐GA nanocomposites require overpotentials of only 52 and 36 mV to achieve a current density of 10 mA cm^(−2) in 1 mol/L HClO4 and 1 mol/L KOH electrolytes for HER,respectively,which is comparable to 20 wt%Pt/C electrocatalyst.Benefiting from the ultrafine size and uniform dispersion of the Ru‐NCs,the synergy between Ru and the highly conductive substrate,and the anchoring effect of the N atom,the Ru‐NCs/N‐GA nanocomposites exhibit excellent activity and durability in the pH‐universal HER,thereby opening a new avenue for the production of commercial HER electrocatalysts.

Preparation of Mesoporous Carbons from Acrylonitrile-methyl Methacrylate Copolymer/Silica Nanocomposites Synthesized by in-situ Emulsion Polymerization

Acrylonitrile-methyl methacrylate （AN-MMA） copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2＇-azobis（2-amidinopropane） dihydrochloride absorbed onto colloidal silica particles, and the mesoporous carbon materials were prepared through carbonization of the obtained AN-MMA copolymer/silica nanocomposites, followed by HF etching. Thermogravimetric analysis of AN-MMAcopolymer/silica nanocomposltes snoweO mat me caroon ylelCl or copolymer was slgnuy oecreaseo as Silica parucle incorporated. N2 adsorption-desorption, scan electron microscopy （SEM） and transmission electron microscopy （TEM） were used to characterize the structure and morphology of the mesoporous carbon materials. Both SEM and

Preparation of in-situ Cu/NbC nanocomposite and its functionally graded behavior for electrical contact applications

Cu–15%NbC (volume fraction) powder was synthesized using the starting powders of Cu, Nb and graphite in a high energy vibratory disc mill for 7 h of milling under argon atmosphere. A composite sample and a Cu/NbC functionally graded material (FGM) sample were produced by using the two-step press and sintering at 900 °C for 1 h under vacuum. The microstructure and physical and mechanical properties of the specimens were investigated. The field emission scanning electron microscopy, energy dispersive X-ray and X-ray diffraction analysis confirmed the synthesis of the nanostructure matrix of 18–27 nm with the nanoparticles reinforcement of 42 nm after sintering, verifying the thermal stability of this composite at high temperature. The hardness of Cu–15%NbC was five times greater than that of the pure Cu specimen. The volume reduction of the sample after the wear test decreased in comparison with the pure Cu specimen. The electrical conductivity of the composite specimen decreased to 36.68% IACS. The FGM specimen exhibited high electrical conductivity corresponding to 75.83% IACS with the same hardness and wear properties as those of the composite sample on the composite surface. Thus, Cu/NbC FGM with good mechanical and electrical properties can be a good candidate for electrical contact applications.

Nano Fibrous Cerium（IV） Hydrogen Phosphate Membrane Self Supported Indole Polymerization Agent

Nanosized fibrous cerium（IV） hydrogen phosphate membrane, Ce（HPO4）2·2.9H20 （nCePf）, was prepared and characterized by chemical, XRD （X-ray diffraction）, TGA （thermogravimetric analysis）, SEM （scanning electron microscopy） and TEM （transmission electron microscopy）. Novel supported nanofibrous Ce（IV） phosphate/polyiondole nanocomposite membranes were prepared via in-situ chemical oxidation of the monomer that was promoted by the reduction of Ce（IV） ions present in the inorganic matrix. The presence of Ce（IV） ions allows redox reactions necessary to oxidative polymerization to occur. The resultant material was characterized by TGA, elemental （C, H, N） analysis and FT-IR （Fourier transform spectroscopy）. SEM images of the resulting nanocomposite reveals a uniform distribution of the polymer on the inorganic matrix. Amount of polyindole polymer present in the composite is found to be - 7.0%.

Mycotoxins in Brewing Grain Raw Material （Barley, Malt） in Russia

The levels of five mycotoxins （MT）： deoxynivalenol （DON）, T-2-toxin （T-2）, zearalenone （ZEA）, aflatoxin （Aft）, ochratoxin A （OTA） were measured in malting barley and malt samples by enzyme immunoassay （ELISA）, using test systems RIDASCREEN FAST （R-Biopharm, Germany）. 40 samples of malting barley, mainly from the Central part of European Russia and fewer from the Southern part of, and also some samples from Altai （Asian Russia） were analyzed during 2007-2011 years as well as 120 samples of malt from Russian malting companies. It was found that 17% of barley samples were contaminated with MT; in two cases （5%）, the MT concentration exceeded maximum allowable levels （MAL）. Among malt samples in more than half （in 56%） MT were detected, in 9% of samples, the MT concentration exceeded MAL （Aft-3 incidents, T-2-3 incidents, OTA-2 incidents, ZEA-1 incident）. Maximum levels ofmycotoxins in malt were found to be higher than those in barley. These facts support the idea about risky conditions during malting processing.