基于PCI-6013汽车动态轴重系统设计与实现

本文以介绍了一个基于PCI-6013用于动态测量的轴重系统,讨论了轴重系统的软硬件构成,同时给出了系统的软件实现。系统还能够自动测量车速和轴距以及对车型分类进行分类,具有很强的实用性和适用性。     

真菌多糖对鼠李糖乳杆菌体外增殖的影响

通过液体发酵提取曲霉HGY8和云芝胞内胞外多糖,脱蛋白,制成一定浓度溶液。选用MRS培养基,采取试管法,试验曲霉和云芝多糖对鼠李糖乳杆菌增殖的影响,并将其应用于鼠李糖乳杆菌发酵乳的研究中。结果表明:0.5%、1%的曲霉和云芝多糖对鼠李糖乳杆菌体外增殖均有极显著的效果(P<0.05)。不同浓度相比之下,2%的曲霉多糖和1%的云芝多糖更能提高鼠李糖乳杆菌的活性,缩短凝乳时间。初步显示,曲霉和云芝多糖中含促生长因子。     

鼠李糖乳杆菌(LGG)的功能特性及其应用前景

鼠李糖乳杆菌LGG(Lactobacillus rhamnosus GG,ATCC 53103)是目前最受全球关注的益生菌之一。该菌能够耐受动物消化道环境,具有能够在人和动物肠道内定植,起到调节肠道菌群、预防和治疗腹泻、排除毒素、预防龋齿和提高机体免疫力等功能特性。     

Production of lactic acid from vine‐trimming wastes and viticulture lees using a simultaneous saccharification fermentation method

An effective process for the chemical–biotechnological utilization of trimming wastes of vineshoots, an agricultural waste with little use, is reported. Initial treatment with sulfuric acid (prehydrolysis) allowed the solubilization of hemicelluloses to give xylose and glucose‐containing liquors (suitable to make fermentation media for lactic acid production with Lactobacillus pentosus) and a solid phase containing cellulose and lignin. The solid residues from prehydrolysis were treated with NaOH in order to increase their cellulase digestibility. In the alkaline treatments, the effects of temperature (in the range, 50–130 °C), reaction time (30–120 min) and NaOH concentration (4–12 wt% of solution) on the composition and susceptibility to enzymatic hydrolysis of solid residues were assessed by means of an experimental plan with factorial structure. The lignin content decreased, whereas the susceptibility towards the enzymatic hydrolysis increased with temperature, reaction time and NaOH concentration within the tested range. Using the cellulosic residues achieved under the harsher conditions, favorable fermentation kinetics during simultaneous saccharification and fermentation carried out by L rhamnosus for lactic acid production were observed. The nutrients employed were the complete MRS broth and a cheaper medium developed using viticulture lees coming from the white wine making technology. In all cases the final lactic acid concentration achieved was similar, although the volumetric productivity was lower when using lees due to inhibitory effects over the enzymatic hydrolysis. Copyright © 2004 Society of Chemical Industry     

反复镦压6013型铝合金的组织和性能

以6013型铝合金为试验对象,研究了反复镦压工艺制备细晶材料,消除合金各向异性的可行性。采用金相显微镜,透射电镜研究了6013型铝合金反复镦压对合金组织和性能的影响。结果表明:反复镦压使合金内部产生取向各异、彼此交错的变形带,有利于细化合金组织,经480℃,2 h的退火处理后,合金发生再结晶,合金晶粒等轴化,大小分布均匀,与未反复镦压合金组织相比,晶粒显著细化,减轻了组织各向异性;合金强度随镦压道次的增加,先降低后升高,对镦压后的合金进行T6处理(560℃,2 h+191℃,4 h),反复镦压3道次和12道次合金的硬度分别为1418.5和1503.5 MPa。研究表明:反复镦压工艺可以有效细化晶粒,消除组织各向异性,多道次镦压后,合金强度有所提高。     

Evaluation of genetic polymorphism among Lactobacillus rhamnosus non-starter Parmigiano Reggiano cheese strains

Parmigiano Reggiano (PR) is an Italian cooked, long-ripened cheese made with unheated cow's milk and natural whey starter. The microflora is involved in the manufacturing of this cheese, arising from the natural whey starter, the raw milk and the environment. Molecular studies have shown that mesophilic non-starter lactic acid bacteria (NSLAB) are the dominant microflora present during the ripening of PR. In this study, a characterisation of Lactobacillus rhamnosus isolated from a single PR manufacturing and ripening process is reported, using a combination of genotypic fingerprinting techniques (RAPD-PCR and REP-PCR). The intraspecies heterogeneity evidenced for 66 strains is correlated to their abilities to adapt to specific environmental and technological conditions. The detection of biotypes that correlate with specific moments in cheese ripening or differential development throughout this process suggests that these strains may have specific roles closely linked to their peculiar technological properties.     

Microencapsulated Lactobacillus rhamnosus GG powders: relationship of powder physical properties to probiotic survival during storage

Freeze-dried commercial Lactobacillus rhamnosus GG (LGG) were encapsulated in an emulsion-based formulation stabilized by whey protein and resistant starch and either spray-dried or freeze-dried to produce probiotic microcapsules. There was no difference in loss of probiotics viability after spray drying or freeze drying. Particle size, morphology, moisture sorption, and water mobility of the powder microcapsules were examined. Particle size analysis and scanning electron microscopy showed that spray-dried LGG microcapsules (SDMC) were small spherical particles, whereas freeze-dried LGG microcapsules (FDMC) were larger nonspherical particles. Moisture sorption isotherms obtained using dynamic vapor sorption showed a slightly higher water uptake in spray-dried microcapsules. The effect of water mobility, as measured by nuclear magnetic resonance (NMR) spectroscopy, at various water activities (a(w) 0.32, 0.57, and 0.70) and probiotic viability during storage at 25 °C was also examined. Increasing the relative humidity of the environment at which the samples were stored caused an increase in water mobility and the rate of loss in viability. The viability data during storage indicated that SDMC had better storage stability compared to FDMC. Although more water was adsorbed for spray-dried than freeze-dried microcapsules, water mobility was similar for corresponding storage conditions because there was a stronger water-binding energy for spray-dried microcapsule. This possibly accounted for the improved survival of probiotics in spray-dried microcapsules.     

鼠李糖乳酸杆菌对河豚肝脏中河豚毒素毒性的影响

以野生河豚肝脏中的河豚毒素（tetrodotoxin,TTX）为研究对象,研究活化与热灭活处理的鼠李糖乳杆菌对其毒性的消减作用。将活化的与热灭活处理的鼠李糖乳杆菌作为材料对TTX进行脱除,采用酶联免疫吸附剂测定（enzyme-linked immunosorbnent assay,ELISA）、层析试纸检测和小鼠生物法分析TTX消减率的变化,采用气相色谱-质谱分析发酵处理后的肝脏二十碳五烯酸（eicosapentaenoic acid,EPA）与二十二碳六烯酸（docosahexaenoic acid,DHA）含量变化。竞争性ELISA结果显示加热灭活后的鼠李糖乳杆菌对TTX的消减率高达82.16%;而未经灭活处理的鼠李糖乳杆菌对TTX的消减率为70.05%,表明热灭活处理的鼠李糖乳杆菌消减效果更佳。此外,经鼠李糖乳杆菌发酵7 d后野生河豚肝脏的TTX消减率为93.27%,气相色谱-质谱检测结果显示发酵后肝脏内的EPA与DHA含量分别减少了11.93%、22.50%。综上所述,鼠李糖乳杆菌能消减河豚肝脏中的TTX,经鼠李糖乳杆菌发酵处理后消减效果更佳,本研究结果可为河豚内脏组织的毒性消减提供参考。     

鼠李糖乳杆菌对河豚毒素的免疫活性消减作用方式

为探究鼠李糖乳杆菌（Lactobacillus rhamnosus）对河豚毒素（tetrodotoxin，TTX）免疫活性的消减作用方式和可能作用位点，分别采用活化、热灭活和破碎的鼠李糖乳杆菌以及去除胞外多糖、原生质体、细胞壁和肽聚糖的分离样品，与TTX标准品在37 ℃孵育1 h，使用竞争性酶联免疫吸附法分析作用前后TTX的免疫活性变化。通过化学处理掩蔽鼠李糖乳杆菌表面的羧基和氨基，采用傅里叶变换红外光谱（Fourier transform infrared spectroscopy，FTIR）分析菌体表面的化学键振动类型和官能团变化情况。结果发现，活化、热灭活和破碎后的鼠李糖乳杆菌均可消减TTX的免疫活性，因此TTX免疫活性的变化和鼠李糖乳杆菌的活性无关。各分离样品对TTX的消减作用表明肽聚糖成分对TTX免疫活性的消减率最高可达到47%。FTIR分析发现鼠李糖乳杆菌表面羧基掩蔽后可显著降低TTX免疫活性的消减率至18%，而掩蔽氨基则对作用前后的TTX消减率影响无显著差异（P＞0.05）。实验表明，消减TTX免疫活性的原因可能为TTX与鼠李糖乳杆菌表面肽聚糖上的羧基结合。     

A novel method for elimination of aflatoxin M1 in milk using Lactobacillus rhamnosus GG biofilm

This study aimed to develop a new method for detoxification of milk from aflatoxin M1 (AFM1) by using Lactobacillus rhamnosus GG biofilm. After inoculation of milk contaminated with AFM1 into L. rhamnosus GG biofilm, the unbound AFM1 was extracted and quantified by HPLC. The stability of the formed AFM1/biofilm complex using different AFM1 contamination levels of milk was also studied. We found that the percentages of bound AFM1 by L. rhamnosus GG biofilm reached up to 60.74%. While no significant difference in milk proteins content was observed after AFM1 binding, some changes in total dry matter and fat content were noticed.