牛粪与猪粪混合两相厌氧发酵酸化特性

研究了牛粪分离液和猪粪按比例调配的混合物料,在两相厌氧发酵进程中,物料浓度(TS)分别为8%、1 0%、1 2%时的酸化特性。酸化试验过程中考察的指标有p H、氨氮和挥发性脂肪酸(VFA)等。依据酸化过程中各指标的变化趋势,确定浓度为8%、10%、12%3组混合物料酸化过程的HRT分别为7、5、5天。研究结果可为牛粪分离液与猪粪混合两相厌氧发酵酸化过程工艺参数控制提供依据。

模拟酸雨对烟田土壤酸化及烟草生长发育的影响

我国西南地区是全球酸沉降负荷最高的地区之一,为明确酸性降水给烟田生态系统产生的可能危害,在田间利用自动模拟酸雨监测仪,模拟自然降雨(CK,pH 6.3)、超纯水(T1,pH 6.8)和酸雨(T2,pH 3.5)3种条件,测定其对土壤酸化及阳离子特征、烟草长势、生物量及氮磷钾积累量的影响。结果表明:(1)与CK和T1相比,T2土壤pH显著降低且随时间推移各处理之间差异逐渐增大;T2土壤交换性酸及铝离子含量显著增加,CEC和盐基总量下降;(2)T2显著抑制烟草生长发育,显著降低烟株株高、茎围、有效叶数及叶片长、宽,CK的茎和叶生物量最高,T1的根生物量最高;(3)根中氮和钾的积累量均为T2最低;茎和叶中氮的积累量表现为T2>T1>CK,茎和叶中钾的积累量表现为CK>T2>T1;磷的积累量在不同部位中差异不大,整体表现为T2最低。可见pH 3.5的酸雨能导致土壤明显酸化,显著抑制烟株生长发育,应采取有效措施控制其发生危害。

酸奶冻干发酵剂制备中保加利亚乳杆菌不同菌株特性的研究

研究了不同来源的7株保加利亚乳杆菌在乳中的生长与发酵特性、后酸化活性以及抗冷冻干燥特性。结果表明,7菌株在乳中42℃发酵,L.b-S1和L.b-DR凝乳时间最短,为3 h,凝乳后的活菌数、pH值、滴定酸度均无显著差别,活菌数均达1×108 mL-1以上,pH值均达4.5～5.0,滴定酸度均达90～100°T;7菌株在发酵后的酸乳中冷藏期间,L.b-S1和L.b-DR的后酸化活性最低,4℃冷藏21 d,酸度上浮不足10°T,pH值下降0.2～0.4,活菌数下降1个log数量级左右;7菌株在以脱脂乳为保护剂的冷冻干燥试验中,L.b-S1抗冻干性最强,其次为L.b-DR,其冻干存活率分别达31.46%和20.39%。

不同青贮秸秆的水解产酸特性研究

通过对玉米秸秆粉碎后青贮(青贮秸秆Ⅰ)和榨汁处理后青贮(青贮秸秆Ⅱ)的厌氧酸化过程中pH和挥发酸浓度的比较,分析了青贮方式对产酸特性的影响。结果表明:随着酸化时间的增加,两种青贮秸秆的pH变化趋势均为先降低后升高,总挥发性脂肪酸浓度均呈先升高后降低的趋势。青贮秸秆Ⅰ和青贮秸秆Ⅱ的总挥发酸浓度均在第5天达到最大,分别为12.20 g/L和14.06 g/L。与青贮秸秆Ⅰ相比,青贮秸秆Ⅱ的酸化液中乙酸占总挥发性脂肪酸的比例总体较高,而丙酸所占比例较低。因此,在相同厌氧酸化条件下,由于榨汁处理后青贮的秸秆能够提高酸化过程中挥发性脂肪酸的浓度,改善挥发性脂肪酸的组成,有利于提高后续产甲烷效果。

ABR系统中酸解过程的污泥特性及分析

介绍了ABR酸解过程中污泥的特性 :ABR各隔室酸化污泥外观呈黄褐色絮状污泥 ;污泥表面主要以水解产酸菌为主 ,污泥的沉降性变差 ,易于上浮 ;酸化污泥的产甲烷活性比正常的甲烷发酵低得多。碱度不足是引起酸化的直接原因 ,污泥内存在“死区”范围大 ,加剧酸化的进行。采用同时增加碱度和降低负荷的方式 ,连续调控 6 0d后 ,反应器恢复正常运行 ,恢复后污泥表面仍以产酸菌为主 ,但内部的产甲烷菌已恢复。

木薯渣厌氧发酵制取沼气的研究

研究了木薯渣的酸化特性和不同接种率(60%、70%、80%)对厌氧发酵产沼气的影响。试验结果表明,木薯渣极易酸化,但厌氧发酵甲烷化是可行的,在试验采用的接种率中,70%的接种率能调控发酵系统的pH、VFA浓度在正常范围,产气能顺利启动和进行,产气率和最高甲烷含量分别为249.35ml/g VS和48.16%,优于其他两组,为木薯渣厌氧发酵产沼气的深化研究和应用提供了参考依据。

Purification and Characterization of Glutamate Decarboxylase of Lactobacillus brevis CGMCC 1306 Isolated from Fresh Milk

A Lactobacillus brevis CGMCC 1306 isolated from fresh milk without pasteurization was found to have higher glutamate decarboxylase （GAD） activity. An effective isolation and purification procedure of GAD from a cell-free extract of Lactobacillus brevis was developed, and the procedure included four steps： 30%-90% saturation （NH4）2SO4 fractional precipitation, Q sepharose FF anion-exchange chromatography, sephacryl S-200 gel filtration, and resource Q anion-exchange chromatography. Using this protocol, the purified GAD was demonstrated to possess electrophoretic homogeneity via SDS-PAGE. The purification fold and activity recovery of GAD were 43.78 and 16.95%, respectively. The molecular weight of the purified GAD was estimated to be approximately 62 kDa via SDS-PAGE. The optimum pH and temperature of the purified GAD were 4.4 and 37℃, respectively. The purified GAD had a half-life of 50rain at 45℃ and the Km value of the enzyme from Lineweaver-Burk plot was found to be 8.22.5＇-pyridoxal phosphate （PLP） had little effect on the regulation of its activity.

Biochemical characteristics of neonatal cholestasis induced by citrin deficiency

AIM:To explore differences in biochemical indices between neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and that with other etiologies. METHODS:Patients under 6 mo of age who were referred for investigation of conjugated hyperbiliru-binaemia from June 2003 to December 2010 were eligible for this study. After excluding diseases affecting the extrahepatic biliary system, all patients were screened for the two most common SLC25A13 mutations; the coding exons of the entire SLC25A13 gene was sequenced and Western blotting of citrin protein performed in selected cases. Patients in whom homo-zygous or compound heterozygous SLC25A13 mutation and/or absence of normal citrin protein was detected were defined as having NICCD. Cases in which no specific etiological factor could be ascertained after a com-prehensive conjugated hyperbilirubinaemia work-up were defined as idiopathic neonatal cholestasis (INC). Thirty-two NICCD patients, 250 INC patients, and 39 infants with cholangiography-confirmed biliary atresia (BA) were enrolled. Laboratory values at their first visit were abstracted from medical files and compared. RESULTS:Compared with BA and INC patients, the NICCD patients had significantly higher levels of total bile acid (TBA) [all measures are expressed as median (inter-quartile range):178.0 (111.2-236.4) μmol/L in NICCD vs 112.0 (84.9-153.9) μmol/L in BA and 103.0 (70.9-135.3) μmol/L in INC, P = 0.0001]. The NICCD patients had significantly lower direct bilirubin [D-Bil 59.6 (43.1-90.9) μmol/L in NICCD vs 134.0 (115.9-151.2) μmol/L in BA and 87.3 (63.0-123.6) μmol/L in INC, P = 0.0001]; alanine aminotransferase [ALT 34.0 (23.0-55.0) U/L in NICCD vs 108.0 (62.0-199.0) U/L in BA and 84.5 (46.0-166.0) U/L in INC, P = 0.0001]; aspartate aminotransferase [AST 74.0 (53.5-150.0) U/L in NICCD vs 153.0 (115.0-239.0) U/L in BA and 130.5 (81.0-223.0) U/L in INC, P = 0.0006]; albumin [34.9 (30.7-38.2) g/L in NICCD vs 38.4 (36.3-42.2) g/L in BA and 39.9 (37.0-42.3) g/L in INC, P = 0.0001]; glucose [3.2 (2.0-4.4) mmol/L in NICCD vs 4.1 (3.4-5.1) mmol/L in BA and 4.0 (3.4-4.6) mmol/L in INC, P = 0.0014] and total cholesterol [TCH 3.33 (2.97-4.00) mmol/L in N ICCD vs 4.57 (3.81-5.26) mmol/L in BA and 4.00 (3.24-4.74) mmol/L in INC, P = 0.0155] levels. The D-Bil to total bilirubin (T-Bil) ratio was significantly lower in NICCD patients [all measures are expressed as median (inter-quartile range):0.54 (0.40-0.74)] than that in BA patients [0.77 (0.72-0.81), P = 0.001] and that in INC patients [0.74 (0.59-0.80), P = 0.0045]. A much higher AST/ALT ratio was found in NICCD patients [2.46 (1.95-3.63)] compared to BA patients [1.38 (0.94-1.97), P = 0.0001] and INC patients [1.48 (1.10-2.26), P = 0.0001]. NICCD patients had significantly higher TBA/D-Bil ratio [3.36 (1.98-4.43) vs 0.85 (0.72-1.09) in BA patients and 1.04 (0.92-1.14) in INC patients, P = 0.0001], and TBA/TCH ratio [60.7 (32.4-70.9) vs 24.7 (19.8-30.2) in BA patients and 24.2 (21.4-26.9) in INC patients, P = 0.0001] compared to the BA and INC groups. CONCLUSION:NICCD has significantly different bio- chemical indices from BA or INC. TBA excretion in NICCD appeared to be more severely disturbed than that of bilirubin and cholesterol.

A Simplified Method for Purifying Osteoclasts from Human Giant Cell Tumor of Bone

Objective: To purify and identify the osteoclasts from the tissue of humangiant cell tumor of bone. Methods: We have developed a new method that allows the purification oflarge numbers of authentic osteoclasts (OCs). The OCs were isolated from tissue of human giant celltumor of bone by 0.25% trypsin and collagenase. We characterized OCs in terms of the expression ofdifferent phenotypic markers of OCs. The phenotypic markers of OC included Tartrate-resistant acidphosphatase staining (TRAP). The expression of calcitonin receptor (CTR), cathepsin K and receptoractivator of necrosis factor κB (RANK) mRNA were examined by RT-PCR. Results: The OC cell purifiedby above method functioned normally in vitro. The purity was about 79.7%. They showed the normalosteoclast phenotypes markers of OC. Conclusion: The method provides a system for performingbiochemical and molecular studies of OCs. The study indicates that the method of purifying theosteoclasts from human GCT cell can be used for research of bone metabolism.

Characterization, Acid Activation and Bleaching Performance of Bentonite from Xinjiang

Bentonite produced in Xiazijie, Xinjiang (China) was characterized by X-ray diffraction (XRD), dif- ferential thermal analysis (DTA), thermogravimetric analysis (TG) and cation exchange capacity (CEC). The ben- tonite is composed of dioctahedral montmorillonite with predominant quantity, certain amounts of quartz, feldspar and illite and minor amounts of kaolinite, gypsum, etc. The raw bentonite has a CEC of 0.6497 meq·g-1 and allows to be characterized as typical sodium bentonite. In order to bleach cottonseed oil, optimum conditions for sulfuric acid activation of the raw bentonites were investigated, which were obtained by selecting various acid strength, at 96—98℃ and activating for 4h with 1︰2 solid-liquid ratio. The acid activation bentonites were suitable for decol- orization of cottonseed oil through removing carotene and chlorophyll. The bleaching capabilities of different pig- ments with activated bentonite with treatment of 25% sulfuric acid were 70.3%, 73.1%, 83.2%, 81.8% and 88.9%, respectively. Bleaching with acid activated bentonite gave oils lower peroxide values and acid values.

Effect of CaCO_3 on hydration characteristics of C_3A

Hydration products and morphology characteristics of C3A （tricalcium aluminate）-CaCO3-H2O system were studied by means of XRD, DSC, FTIR spectrum analysis and SEM. The results indicate that, the new phases, i.e., C3A·0.5CaCO3·0.5Ca（OH）2·11.5H2O and C3A·CaCO3·11H2O are found in this system due to the activity of CaC03; the formation of C4AH13 and C2AH8 is prohibited and the generation of C3AH6 is delayed in the early hydration process. C3A·0.5CaCO3·0.5Ca（OH）2.11.5HEO is not stable and will be totally transferred within 24 h; C3A·CaCO3.11H2O exists stably once formation, and its flake-like crystalline phases in the early hydration transform to long rod shape, and to finally fine-needle at 28 d.

Nitrogen removal characteristics of heterotrophic nitrification-aerobic denitrification by Alcaligenes faecalis C16

Alcaligenes faecalis C16 was found to have the ability to heterotrophically nitrify and aerobically denitrify. In order to further understand its nitrogen removal ability and mechanism, the growth and ammonium removal response were investigated at different C/N ratios and ammonium concentrations in the medium with citrate and acetate as carbon source separately. Furthermore, experiments of nitrogen sources, production of nitrogen gas and enzyme assay were conducted. Results show that the bacterium converts NH+4-N and produces NH2 OH during the growing phase and nitrite accumulation is its distinct metabolic feature. A. faecalis C16 is able to tolerate not only high ammonium concentration but also high C/N ratio, and the ammonium tolerance is associated with carbon source and C/N ratio. The nitrogen balance under different conditions shows that approximately28%–45% of the initial ammonium is assimilated into the cells, 44%–60% is denitrified and several percent is converted to nitrification products. A. faecalis C16 cannot utilize hydroxylamine, nitrite or nitrate as the sole nitrogen source for growth. However, nitrate can be used when ammonium is simultaneously present in the medium. A possible pathway for nitrogen removal by C16 is suggested. The preliminary enzyme assay provides more evidence for this nitrogen removal pathway.

Development of Magnesium-Dominant Soils Under Irrigated Agriculture in Southern Kazakhstan

Irrational irrigation practices in the Arys Turkestan Canal command area in the southern part of Kazakhstan have led to the formation of soils with poor physical and chemical properties. To study whether irrigation and leaching practices and/or groundwater rise have contributed to the accumulation of Mg2+ on the cation exchange complex of these soils, historical changes in soil and groundwater quality were used as source data and the Visual MINTEQ model was applied to analyze the chemical composition of water and soils in the study area. The imposed irrigation regime and the leaching of light sierosem soils led to the dissolution and subsequent leaching of inherent gypsum and organic matter from the soil profile. Further, the domination of bicarbonate in the irrigation water promoted weathering of the carbonate minerals present as calcite. The higher concentrations of Mg2+ in comparison to Ca2+ in the irrigation water resulted in the replacement of Na+ by Mg2+ on the cation exchange complex. In the lower part of the command area, shallow groundwater has contributed to the accumulation of Na+ and to a large extent of Mg2+ on the cation exchange sites.

Photo-electrochemical Lithium Insertion Characteristics of Carbon Nanotubes Modified with SrTiO3 Photocatalyst

Perovskite-type SrTiO3 nanoparticles were synthesized by direct hydrolysis-precipitation method and were employed to modify the surface of the carbon nanotubes to form a SrTiO3/CNTs composite. The photoelectrochemical lithium insertion characteristics of the SrTiO3/CNTs composite under xenon light irradiation were investigated. The results show that the light irradiation has little influence on the specific capacity of the CNTs electrode. However, for the SrTiO3/CNTs electrode irradiated by light, the lithium insertion capacity reaches about 251 mAh/g, much higher than that without light irradiation （170 mAh/g）. Cyclic voltammetry test reveals that the light irradiation can remarkably increase the reaction currents of lithium insertion and extraction. This may be attributed to the photo-excited intercalation of Li-ions into the CNTs by the SrTiO3 photocatalyst when irradiated by light.

Improvement of alkaline electrochemical characteristics of bauxite residue amendment with organic acid and gypsum

Neutralization of alkaline properties of bauxite residue(BR)by using organic acid and gypsum additions may effectively improve electrochemical properties and alleviate physicochemical barriers to ecological rehabilitation.Mineral acids,citric acid and hybrid acid–gypsum additions were compared for their potential to transform and improve zeta potential,isoelectric point(IEP),surface protonation and active alkaline-OH groups,which are critical factors for further improvement of physicochemical and biological properties later.Isoelectric points of untransformed bauxite residue and six transformed derivatives were determined by using electroacoustic methods.Electrochemical characteristics were significantly improved by the amendments used,resulting in reduced IEP and-OH groups and decreased surface protonation for transformed residues.XRD results revealed that the primary alkaline minerals of cancrinite,calcite and grossular were transformed by the treatments.The treatments of citric acid and gypsum promoted the dissolution of cancrinite.From the SEM examination,citric acid and gypsum treatments contributed to the reduction in IEP and redistribution of-OH groups on particle surfaces.The collective evidence suggested that citric acid and gypsum amendments may be used firstly to rapidly amend bauxite residues for alleviating the caustic conditions prior to the consideration of soil formation in bauxite residue.

Characteristics of deslanoside-induced modulation on jejunal contractility

AIM:To characterize the dual effects of deslanoside on the contractility of jejunal smooth muscle.METHODS:Eight pairs of different low and high contractile states of isolated jejunal smooth muscle fragment(JSMF) were established.Contractile amplitude of JSMF in different low and high contractile states was selected to determine the effects of deslanoside,and Western blotting analysis was performed to measure the effects of deslanoside on myosin phosphorylation of jejunal smooth muscle.RESULTS:Stimulatory effects on the contractility of JSMF were induced(45.3% ± 4.0% vs 87.0% ± 7.8%,P < 0.01) by deslanoside in 8 low contractile states,and inhibitory effects were induced(180.6% ± 17.8% vs 109.9% ± 10.8%,P < 0.01) on the contractility of JSMF in 8 high contractile states.The effect of deslanoside on the phosphorylation of myosin light chain of JSMF in low(78.1% ± 4.1% vs 96.0% ± 8.1%,P < 0.01) and high contractile state(139.2% ± 8.5% vs 105.5 ± 7.34,P < 0.01) was also bidirectional.Bidirec-tional regulation(BR) was abolished in the presence of tetrodotoxin.Deslanoside did not affect jejunal contractility pretreated with the Ca 2+ channel blocker verapamil or in a Ca 2+-free assay condition.The stimulatory effect of deslanoside on JSMF in a low contractile state(low Ca 2+ induced) was abolished by atropine.The inhibitory effect of deslanoside on jejunal contractility in a high contractile state(high Ca 2+ induced) was blocked by phentolamine,propranolol and L-NG-nitroarginine,respectively.CONCLUSION:Deslanoside-induced BR is Ca 2+ dependent and is related to cholinergic and adrenergic systems when JSMF is in low or high contractile states.

Research progress in ionic liquids catalyzed isobutane/butene alkylation

The complicated reaction mechanism and the character of competitive reactions lead to a stringent requirement for the catalyst of C_4 alkylation process. Due to their unique properties, ionic liquids(ILs) are thought to be new potential acid catalysts for C_4 alkylation. An analysis of the regular and modified chloroaluminate ILs, novel Br?nsted ILs and composite ILs used in isobutane/butene alkylation shows that the use of either ILs or ILs coupled with mineral acid as homogeneous catalysts can help to greatly adjust the acid strength. By modifying the structural parameters of the cations and anions of the ILs, the solubility of the reactants could also be adjusted, which in turn displays a positive effect on improving the activity of ILs. Immobilization of ILs is an effective way to modulate the surface adsorption/desorption properties and acid strength distribution of the solid acid catalysts. Such a process has a tremendous potential to reduce the deactivation of catalyst and enhance the activity of the solid acid catalyst. The development of novel acid catalysts for C_4 alkylation is a comprehensive consideration of acid strength and its distribution, interfacial properties and transport characteristics.

Effect of CaCl2, Citric Acid and Storage Period on Physico-Chemical Characteristics of Cherry Candy

Cherry cultivar Misri （Bigarreau Noir Grossa） was used for making candy. Pitting of fruit was done manually and KMS （0.2%） was added for bleaching. The fruit was pretreated using 4 levels of CaCl2 （Co = 0%, C1 = 1%, C2 = 1.5%, C3 = 2%） and stored in jars for 4 weeks. Thereafter, application of colour was done using Erythrosine （0.05%） followed by dipping pitted fruits in sugar syrup for 24 hours. The samples were treated with 4 levels of citric acid （To = 0%, Tl = 1%, T2 = 1.5%, T3 = 2%） and then concentrated subsequently till desired TSS of 70~ Brix was attained. The samples were dried in cabinet drier at 80 ±20 ℃till constant moisture was attained. The product was packed in polyethene pouches and stored under ambient storage conditions. Results revealed that there was gradual increase in reducing sugars （%）, total sugars （%） during storage while as moisture content （%） decreased. The product developed was found economically profitable and viable for commercial production.

Synthesis and biochemical properties of fluorescent/magnetic bifunctional starch particles

Magnetic starch particles （MSPs） were synthesized in water-in-oil mieroemulsion at room temperature. MSPs were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectrometry （FTIR）, zeta potential system, thermogravimetric analysis （TGA） and vibrating sample magnetometry （VSM）. The average diameter of the MSPs was 220 nm, dispersed with well-proportioned size and magnetic resonance, the saturation magnetization was 3.64 A.mR/kg. MSP was coated with poly-L-lysine （PLL）, and then the surface of PLL-MSP was combined with fluorescein isothiocynate （FITC）. Results show that fluorescent/magnetic starch particles （FMSPs） are of stable photo-bleaching capability compared with free FITC, with low bio-toxicity and certain function of magnetic separation. It is expected that FMSPs are bifimctional nano-materials including fluorescence labelling and magnetic separation.

Preparation and Characterization of Nanosized Al-MCM-41 Using Different Silica Sources

Silica sources influence different aspects of Al-MCM-41 product. The crystallinity of nanosized Al-MCM-41 zeolites prepared crystallization and lead to change in the properties of the final from precursors mixtures containing different silica sources, e.g. tetraethylorthosilicate （TEOS）, colloidal silica （CS）, silicic acid （SA） and fumed silica （FS） have been studied. The produced samples are investigated using XRD, SEM, FT-IR, pyridine adsorption and N2 physisorption. XRD results show that the products obtained from different silica sources are in Al-MCM-41 phase. SEM results show that silica sources influence the produced Al-MCM-41 shape. Using silicic acid leads to formation of spherical crystals, TEOS gives cubical crystals, colloidal silica forms spherical crystals with smaller aggregated, and fumed silica gives rounded crystals. N2 physisorption results show that silica sources influence pore-diameter and pore-volume of the produced Al-MCM-41 ; the pore diameter of the produced Al-MCM-41 in case of colloidal silica, TEOS, fumed silica, and silicic acid are 12, 20, 15, and 17A respectively. Also, the pore volume of the produced AI-MCM-41 in case of colloidal silica, TEOS, fumed silica and silicic acid are 0.78, 0.71, 0.76, and 0.8 cm^3/gm, respectively.