A competitive dual-label time-resolved fluoroimmunoassay for the simultaneous determination of chloramphenicol and ractopamine in swine tissue

A novel dual-label time-resolved fluoroimmunoassay method was developed for the simultaneous determination of chloramphenicol (CAP) and ractopamine (RAC) residues in 18 swine tissue samples, using anti-CAP and anti-RAC monoclonal antibodies labeled with europium (Eu³⁺) and samarium (Sm³⁺), respectively. The detection limits for CAP and RAC were 0.06 and 0.25 ng/g. The recovery from swine muscle samples was 102%–121% for CAP at spiking levels of 0.1–5 ng/g, and 69.8%–85.8% for RAC at spiking levels of 1–10 ng/g. The results obtained from the swine tissue samples using this method showed good agreement with those obtained using ELISA and GC-MS, with correlation coefficients (R) between 0.92–0.98.     

A method for determination of hexokinase activity by RP-HPLC

A method was established to determine the activity of hexokinase by reverse-phase high-performance liquid chromatography(RP-HPLC).The activity of hexokinase was determined by detecting the amount of ADP in the reaction that converts glucose into glucose-6-phosphate.The separation degree of ATP and ADP was as good as 3.46(separation degree>1.5).In the range of 0.01-0.40 mmol/L,there was a good linear relationship between concentration of ADP and its peak areas(the correlation coefficient was 0.999).The relative standard deviation(RSD) of intraday was 1.43%-1.46%,that of interday was 2.12%-2.15%.At 30 °C(optimal temperature) and pH7.0(optimal pH),the recovery rate of hexokinase was 95.3%-97.6%.The results showed that the method had good precision and high recovery rate,and the enzyme activity was determined through only one-step reaction.To some extent,this method can reduce the cost.     

Treatment efficiency of integrated vertical-flow constructed wetland for saline wastewater

The integrated vertical-flow constructed wetland(IVCW) was simulated with three suits of designed experiment columns planted with Kandelia candel.Units A,B and C were irrigated with sewage of different salinity(A:10‰ B:20‰,C:30‰),respectively.The removal rates of dissolved organic carbon(DOC),NH3-N and NO3--N dropped 90.4%-48.6%,80.2%-40.3% and 84.8%-60.9%,respectively,when salinity increases from 10‰ to 30‰.The removal rate of TP increased 14%-31.2%,oppositely.A 20-day inflow salinity drastic change shock affective trial was done on units D and E.Unit D was used as a control and irrigated with saline sewage(20‰).Unit E was irrigated with sewage with low salinity(5‰) as a salinity drastic change shock on the third and fourth days.DOC,NH3-N and NO3--N removal efficiency of unit E showed a three-stage process of change,"rapidly decrease,increase beyond the normal standard,and then back to the normal standard".TP removal value was negative during the 2-day shock period.     

Levels and distributions of polychlorinated naphthalenes in sewage sludge of urban wastewater treatment plants

Over seventy congeners of polychlorinated naphthalenes （PCNs） in sewage sludge of 8 urban waste- water treatment plants （WWTPs） in Beijing were analyzed by isotope dilution, and high resolution gas chromatography/high resolution mass spectrometry （HRGC/HRMS） method, The total PCN concentrations determined in the samples range from 1.48 to 28.21 ng/g dw （dry weight） with TEQ concentrations of 0.11--2.45 pg/g dw. These levels were lower than those found in other regions, DiCNs and TrCNs were the most dominant homologues of PCNs, The similar congener profiles in all the samples suggest the similarity in certain sources, Contamination from industrial input might be the most significant source of PCNs in the sludges in this study, and thermal processes such as waste incineration and coal combustion may be another source of the PCNs contamination.     

Spectrofluorimetric determination of tetracycline using Eu3+ chelation and cetyltrimethylammonium bromide

The fluorescence of tetracycline was greatly enhanced by chelation with Eu³⁺ in Tris-HCl buffer (pH8.5). The addition of cetyltrimethylammonium bromide, a cationic surfactant, further enhanced the fluorescence of tetracycline-Eu³⁺ chelates. This spectrofluorimetric method for the determination of tetracycline yielded a linear responses in the range of 10 nmol/L–10 μmol/L. The detection limit was 5 nmol/L (or 2.22 ng/mL). The recovery of tetracycline spiked in serum at levels of 1 and 0.09 μg/mL was 97.9% and 97.8%, respectively. This method is fast, sensitive and suitable for the determination of tetracycline in biological specimens. Foundation item: Supported by the National Natural Science Foundation of China Biography: Huang Zu-yun (1963-), male, Ph D.     

Optimizing Conditions of Enhancing Granule Sludge Concentration and Performance

An expanded granular sludge bed （EGSB） reactor was adopted to study the influence factors and rule of enhancing granular sludge concentration and performance. The experiment was performed at 33 ℃, pH 6.0-8.0 with continuous flow by adding proper quantity of nutritional trace elements. The results show that SLR was the key of steady operation of EGSB reactor. The increment of the granular sludge was influenced by volume loading rate （VLR）, liquid up-flow velocity and sludge loading rate （SLR）. Concentration of granular sludge increased rapidly when liquid up-flow velocity was over 0.94 m · h^-1 with SLR being at 1.0-2.0 d ^-1. With the propriety parameters： liquid up-flow velocity 2.52 m · h^-1, SLR 1.0-2.2 d^-1 and VLR 8.2-13.1 kg · m ^3 · d^-1, 23 days＇ continuous operation resulted in an increment by over 80% of granular sludge concentration in the EGSB reactor, plus good granular sludge property.     

Determination of sulfonamides with fluorescent inclusion complex of carbonic anhydrase and dansylamide

A new fluorimetric method for determination of sulfonamides was described based on the formation of a fluorescent inclusion complex of carbonic anhydrase(CA) with dansylamide(DNSA). The binding of DNSA to CA resulted in an enhancement in the fluorescence emission at 460 nm with excitation at 280 nm. Dissociation constants were determined for the carbonic anhydrase sulfonamide complexes. Linear calibration graphs of sulfonamides were obtained within a concentration range of 0- 0.058 μg/mL for DNSA; 0-0.344 μg/mL for sulfanilamide (SAN) and 0-0.286 μg/mL for P toluenesulfonamide (PTSN). The relative standard deviations were within 1.8%-4.2%. Limits of detection for DNSA, SAN and PTSN were 0.84, 19.5 and 6.1 ng/mL, respectively. The method was applied to the determination of sulfonamides in cow milk at ng/mL level.     

Rice protoplasts isolated directly from mature-embryo-derived calli

Mature-embryo-derived calli of japonica rice (Oryza sativa L) Taipei 309 were used for replicated protoplast isolation experiments. Six out of nine callus lines produced protoplasts with satisfactory yield of 5.20×10⁶–8.96×10⁶ protoplasts/g FW (fresh weight). The remaining three callus lines initiated from seeds of cryopreserved-callus-derived plants had rooty calli, resulting in low yield of protoplasts and a large number of isolated banana-shape intact cells. Viability of protoplasts ranged 87.46%–94.15%. The average size of protoplasts was 207.49–379.04 μm² in different callus lines. Comparitive experiments were also carried out using both calli and suspension culture cells for protoplast isolation. The results demonstrated that protoplast isolation of calli was a substantially simplified and reliable method for preparing rice protoplasts. Jin Deming: born in Jan. 1959, Associated Professor     

A practical artificial diet for the diamondback moth

A new artificial diet for the diamondback moth,Plutella Xylostella (L), had been selected out successfully. The diet contained the following constituents: soybean powder, wheat germ, wheat bran powder, brewer's yeast and other constituents. So far, the diamondback moth had been reared on this artificial diet for 25 generations and still mantained its normal biological characteristics. Under 25±1 C and 60%–75%RH with 12 h PH, the results of rearing the diamondback moth on the diet as follows: egg hatch, 81.3%–94.7%; survival from eggs to pupae, 55.0%–76.7%; pupal survival, 79.7%–100%; adult emergence, 80%–100%; fecundity 94.7–144. 4 eggs/♀; pupal weight, 90.4–110.8 mg/20 pupae; average days to adult: ♀, 10.2; ♂ 13.1. The diet is not only simpler on the constituents but also have better rearing results and more rearing generations. Li Guanghong: born in June 1965, Ph.D. graduate student. Current research interest is in entomo logical physiology Supported by the State Eighth Five-Year-Plan     

Genome organization and phylogenetic tree analysis of Garlic virus E, a new member of genus Allexivirus

The complete sequence of an Allexivirus isolated from garlic plants in Yuhang City, Zhejiang Province, China had been determined. The single-strand, positive RNA genome was 8451 nucleotides in length excluding poly(A) tail. The genome organization of this virus was similar to that of the other Allexiviruses but only with 62.8%–64.8% nucleotide acid identities. The amino acid sequences of proteins encoded by ORF1-6 shared 67.6%–78.5%, 55.4%–66.2%, 56.7%–66.4%,40.3%–55.6%,66.3%–79.7%and 52.2%–68.8% identities with those of the others respectively. The homology range between it and the other Allexiviruses was similar to that between the other distinct species in this genus. A more comprehensive comparison using all available CP amino acid sequences showed that it shared only 63.9%–79.8% amino acids identical with the others. Therefore, it had been considered as a new member of the genus, named as garlic virus E (GarV-E). Phylogenetic analysis confirmed GarV-E as a distinct member and the correct names and classification of some members of genus Allexivirus were also discussed.     

Sanitary Sewage Treatment with Jet Inner-loop Bioreactor

0　IntroductionThejetloopreactorhasthecharacteristicsofbothjetandloopflow .Ononehand ,theairsuckedinisdispersedintosmallgasbubblesbecauseoftheshearingforcecausedbythehighvelocityjet,producinganincreasedinterfacialcontactbe tweengasandliquid ,thusthemasstransferefficiencyisin creased .Ontheotherhand ,aregularloopflowisformedbecauseofmutualimpetusofbothjetandair lift,thusdramaticallyim provestheperformancesofmixture ,diffusion ,masstransferandheattransferofthematerial.Withoutmechanicdriving ,the…     

Origin of middle Miocene leucogranites and rhyolites on the Tibetan Plateau: Constraints on the timing of crustal thickening and uplift of its northern boundary

Leucogranites play a significant role in understanding crustal thickening, melting within continental collisional belts, and plateau uplift. Field investigations show that Miocene igneous rocks from the Hoh Xil Lake area mainly consist of two-mica leucogranites and rhyolites. We studied the Bukadaban two-mica leucogranites and the Kekao Lake, Malanshan and Hudongliang rhyolites by zircon U-Pb, muscovite and sanidine 40Ar/39Ar geochronology, and whole-rock geochemical and Sr-Nd isotopic analysis. Results yielded crystallization and cooling ages for the Bukadaban leucogranites of 9.7±0.2 and 6.88±0.19 Ma, respectively. Extrusive ages of the Kekao Lake and Malanshan rhyolites are 14.5±0.8 and 9.37±0.30 Ma, respectively. All rocks are enriched in SiO2 (70.99%-73.59%), Al2O3 (14.39%-15.25%) and K2O (3.78%-5.50%) but depleted in Fe2O3 (0.58%-1.56%), MgO (0.11%- 0.44%) and CaO (0.59%-1.19%). The rocks are strongly peraluminous (A/CNK=1.11?1.21) S-type granites characterized by negative Eu anomalies (δ Eu=0.18-0.39). In also considering their Sr-Nd isotopic compositions (87Sr/86Sri=0.7124 to 0.7143; δ Nd (9 Ma) =-5.5 to -7.1), we propose that these igneous rocks were generated through dehydration melting of muscovite in the thickened middle or lower crust of northern Tibet. Melting was probably triggered by localized E-W stretching decompression in the horse tails of Kunlun sinistral strike-slip faults. Reactivation of the Kunlun strike-slip faults, accompanied by emplacement of leucogranite and eruption of rhyolite in the Hoh Xil Lake area, indicates that large-scale crustal shortening and thickening in northern Tibet mainly occurred before 15 Ma. In addition, these findings suggest that the northern Tibetan Plateau attained its present elevation (~5000 m) at least 15 Ma ago.     

污水处理中雌酮的定量分析

采用酶联免疫吸附检测(ELISA)试剂盒定量分析了某采用生物脱氮活性污泥工艺的污水厂中的原水、一级处理出水、二级处理出水、尾水和出水口下游受纳河水中的雌酮浓度,分析方法的定量检测限为0.5 ng/L.ELISA分析中增加的凝胶色谱净化步骤可降低E1检测值73.0%的假阳性,使其检测结果平均值从液相色谱一飞行时间质谱联用(HPLC-MS(TOF))的对照分析结果平均值的1.52倍降为1.15倍.ELISA分析检测值的假阳性与水样的污染程度呈正相关.     

Applications of crown ether cross-linked chitosan for the analysis of lead and cadmium in environmental water samples

A new type of crown ether cross-linked chitosan was synthesized by the reaction of chitosan with 4,4′-dibromodibenzo-18-crown-6 (Br-DBC). Its token structure was analyzed with FT-IR and NMR and the adsorption behaviors for lead and cadmium in environmental water samples by FAAS were studied. In addition the best analysis conditions were discussed and the adsorption mechanism was explained. As the enrichment factor is above 100, both recoveries are 94%–106%, the detection limits of lead and cadmium are 0.5μg·L⁻¹ and 0.04 μg·L⁻¹ and the relatively standard deviations of lead and cadmium are 3.1% and 2.8% respectively, this new method was successfully applied to the determination of environmental water samples. This method is fast and simple and it greatly enhances the determination ability of FAAS for lead and cadmium. Foundation item: Supported by the State Education Committee Doctoral Foundation (No. 2000048615) Biography: Tang Yu-rong(1943-), female, Associate professor, research direction: trace elements analysis.     

The recognition of adakite-type gneisses in the North Dabie Mountain and its implication to ultrahigh pressure metamorphic geology

Adakite[1] is an igneous rock generated by the partial melting of subducting ocean slab in an island arc setting. Meanwhile, residuals of the slab-melting are transformed to eclogite or garnet-amphibolite during a slab subduction process. This note reports the adakite-type grey gneisses discovered in the North Dabie Mountain. These adakitic rocks are characterized by high Al2O3 (14.97%-17.56%), Sr (545-941 μg/g), Sr/Y (44.71-218.98), La/Yb (16.70-97.50), and low Y (3.32-12.19?μg/g), Yb (0.31-1.34 μg/g), Sc (0.92-4.2 μg/g), as well as positive Sr anomaly but absent or positive Eu anomaly. They are different from the low aluminum grey gneisses with low Al2O3 (13.73%-14.38%), Sr (262-409μg/g), Sr/Y (6.46-15.97) and La/Yb (1.90-22.60), high Y(21.79- 36.24 μg/g), Yb (2.00-5.59 μg/g) , Sc (8.30%-12.70%), and negative Sr, Eu anomaly in the North Dabie Mountain. The adakite-type grey gneisses in the North Dabie Mountain were most probably formed by the partial melting of subducting ocean slab before the Indo-Chinese epoch. We suggest that the subducting of an ocean slab took place prior to the incorporation between the Yangtze and North China plates in the Indo-Chinese epoch, resulting in formation of adakite-type igneous rocks and some ultrahigh pressure eclogites related to the subducted ocean slab. Therefore, besides the ultrahigh pressure metamorphism of the Indo-Chinese epoch, some ultrahigh pressure ecoglits were most likely formed prior to the Indo-Chinese epoch in the Dabie Mountain. In addition, the adakite-type grey gneisses with arc origin occur in the North Dabie Mountain, inferring that the Yangtze plate subducted down below the North China plate and the main suture zone between the two plates was likely along the southern side to the North Dabie Mountain.     

Preconcentration and Separation of Trace Copper in Water Samples with Nanometer-Size TiO2 Colloid and Determination by FAAS

A new absorbent of nanometer-size TiO2 colloid for Cu(Ⅱ) was studied in this work. The adsorption rate could reach above 99% when the pH values were at the range of 5-6. The adsorption balance time, adsorption capacities, and the eluent were investigated. A novel method of trace Cu(Ⅱ) preconcentration and separation with nanometer-size titanium dioxide colloid and determination by flame atomic absorption spectrometry (FAAS) was advanced. The detection limit (3σ) of the method was 1.15 μg· L~(-1) , and the relative standard deviation (R.S.D) was 1.53% (n=6). Environmental sample experiments were also conducted to test the feasibility of the method, and it came out that the recovery rates were between 95.9% and 97.8%.     

流动注射-冷蒸汽发生AAS法测定烟草样品中的痕量汞

 研究了以KBH₄为还原剂的流动注射-冷蒸汽发生原子吸收光谱法,测定烟草中痕量汞.就其分析条件对灵敏度影响进行了优化研究.本方法共存离子干扰小,精密度较高(平行测定10ng/mL的标准样品7次的相对标准偏差为2.80%)、检测限好(0.4ng/mL),线性范围在0.4～60ng/mL之间.利用HNO₃-H₂O₂体系微波消解进行了样品前处理,有较高的样品回收率(98.15%).测定结果令人满意.     

Melt rheology of poly (lactic acid) plasticized by epoxidized soybean oil

This study investigated that epoxidized soybean oil (ESO) was blended as plasticizer with poly (lactic acid) (PLA) and its effects on the melt rheological properties, such as melt flow index, apparent shear viscosity, and melt strength of the blends. PLA was blended by the twin-screw plastic extruder at five mass fractions: 3%, 6%, 9%, 12%, and 15% (based on PLA mass). Melt flow index (MFI) was examined with a melt flow indexer. The results indicate that the blends of PLA/ESO had higher MFI than pure PLA, except for MFI at 9% reaching to the lowest point, even lower than that of pure PLA. Melt rheological properties were studied by a capillary rheometer in a temperature range of 160–180 °C. The blends ends exhibited shear-thinning behavior and the apparent shear viscosity was well described by the power law in this shear rate region. The melt strength of PLA plasticized with 6% ESO reached the maximums. ESO was more effective in increasing the melt strength at the mass fractions less than 6%, which could toughen the blends to some extent. Therefore, the authors suggested the optimum addition level of 6%–9% ESO will get good melt rheological performance balance. Biography: XU Yuqiong (1974–), female, Ph.D., research direction: polymer composites.     

Occurrence of perfluoroalkyl acids in precipitation from Shenyang, China

Perfluorosulfonates （PFSAs） and perfluorocarboxylates （PFCAs） in precipitation collected from Shenyang, China were determined. Snow samples were collected in the snow event on March 4, 2007 from 34 sites involving both the urban and suburban areas in Shenyang. The snowmelt was preconcentrated by solid phase extraction and analyzed using LC-MS method. Measurable amounts of perfluoroalkyl acids （PFAS） were found in precipitation samples from Shenyang, demonstrating that wet deposition is one possible pathway for the removing of the selected PFAS chemicals from atmosphere. Major PFAS detected were PFOS （〈0.38-51 ng/L）, PFOA （0.82-13 ng/L） and PFHpA （0.76-11 ng/L）, with their mean concentration of 5.4, 3.3 and 2.9 ng/L, respectively. Other PFSAs and PFCAs were detected at much lower frequency or below the limit of detection in all the samples. The work presented here offers some basis for the investigation on the environmental behavior and the evaluation of human exposure to PFAS.     

Myoglobin as Mimetic Enzyme and Its Analytical Application in Determination of H2O2

0 IntroductionSltougdiiceasl csoynstceermnsin gharveeac btieveen o txhyeg ei nm psopretcaienst ( oRbjOecSt) iinn bbiioo--medicine and analytical chemistry in recent years[1-4]. Manyi mportant life phenomena and diseases are relatedtotheinter-mediates of ROS[5-7].ROS have beeni mplicated as ani mpor-tant causative factor in cell damage,including apoptosis andnecrosis . Their proposed actions comprise lipid peroxidation,DNAdamage,the mitochondrial respiratory chain destructionand protein mo…