小分子水测试剂显色原理的探究

针对利用“小分子水测试剂”在检测含有小分子水的样品时变红这一实验现象,设计了相应的对比探究实验,从测试剂的成分以及生活中几种常见饮用水的pH这两种因素来分别探究“小分子水测试剂”能在小分子水中显示红色的原因,从而引导我们正确看待“小分子水”在生活、生产等方面的重要作用。

默克公司COD测试剂的替代品开发

德国默克(MERCK)公司制造的COD测定仪在我国环保行业、科研院所的水质监测工作中应用广泛,但配套测试剂价格昂贵,限制了该仪器的使用.设计了高量程(100～1 500 mg/L)和低量程(25～100 mg/L)下COD测试剂替代品的开发方案.通过实验,确定了两个量程下COD测试剂替代品中K2Cr2O7,H2SO4-Ag2SO4,HgSO4的浓度和加入量以及测试方法.实验结果表明,在高量程和低量程范围内,使用COD测试剂替代品的测试结果与MERCK公司配套测试剂的测试结果比较相符,反应时间也可缩短至0.5 h.

COD测试剂及其应用方法的研究

研制出一种新的COD测试剂并创立一种用分光光度计准确快捷、高效、经济地测定污水中的COD值的方法 。

蔬菜农药残留速测方法中若干问题的探讨

随着“无公害蔬菜”、“放心菜”工程的开展,蔬菜上农药残留速测技术备受关注,各种速测方法应运而生,作者对常见的几种速测技术的原理与方法进行了评价,对目前速测方法中存在的重现性差、灵敏度低、误差大、实用性差等问题进行了讨论,为防止未成熟产品、伪劣产品流入市场,影响“三绿工程”的正常开展,提出建立多学科协作研究体系,把农药残留速测技术提高到一个新水平。

Performance analysis of three-stage liquid desiccant deep dehumidification processor driven by heat pump

A new type of a heat pump driven three-stage lithium bromide liquid desiccant deep dehumidification processor is presented,which can dehumidify the outdoor humid air to a rather dry state,even when there is no available indoor exhaust air.The test results show that with an outdoor air temperature of 28 to 31 ℃ and an outdoor air humidity ratio of 11 to 14 g/kg,the supply air temperature and the supply air humidity ratio are 1.6 to 2.6 ℃ and 2.6 to 3.0 g/kg,respectively,and the coefficient of performance（COP）of the processor is 1.8.During the test,a liquid pipeline link problem leading to mixture losses of hot and cold liquid desiccants is found.These pipelines are modified.Then,the performance of the modified processor is investigated.And the experimental results show that with an outdoor air temperature of 25 to 32 ℃ and an outdoor air humidity ratio of 18 to 21 g/kg,the supply air temperature and the supply air humidity ratio are 3.2 to 4.0 ℃ and 3.4 to 3.6 g/kg,respectively,and the COP is 2.8.Finally,a mathematical model of the processor is established.The comparison of the simulation results and the test results of the processor exhibits that the pipeline modification improves the performance by about 20%.

Study on Agrobacterium tumefaciens-mediated Transformation of Brassica campestris L. with Fusion Gene Ycoil-bFGF

[ Objective] The study is to generate pharmaceutical protein via plant transgenic technique. [Methed] Using the cotyledons with petiole as transformation receptor, the fusion gene of rapeseed oil-body gene and bFGF was introduced into the rapeseed （ Brassica campestris L. ） by Agrobacterium tumefaciens-mediated transformation; meanwhile regeneration conditions of rapeseed were also optimized, and the regenerated resistant plantlets were detected by PCR and Southern blot. [ Result] This fusion gene had been integrated into rapeseed genome successfully, and the optimized conditions of transformation and regeneration were as follows： explants pre-culture for 2 d, co-culture for 3 d, bacteria solution OD600 for 0.3 and infection time for 5 min. [ Conclusion] The results laid a solid foundation for extraction, isolation and purification of protein in transgenic plant seeds.

Pro-apoptotic effects of tectorigenin on human hepatocellular carcinoma HepG2 cells

AIM:To investigate the effects of tectorigenin on human hepatocellular carcinoma(HCC)HepG2 cells.METHODS:Tectorigenin,one of the main components of rhizome of Iris tectorum,was prepared by simple methods,such as extraction,filtration,concentration,precipitation and recrystallization.HepG2 cells were incubated with tectorigenin at different concentrations,and their viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Apoptosis was detected by morphological observation of nuclear change,agarose gel electrophoresis of DNA ladder,and flow cytometry with Hoechst 33342,Annexin V-EGFP and propidium iodide staining.Generation of reactive oxygen species was quantified using DCFH-DA.Intracellular Ca2+was monitored by Fura 2-AM.Mitochondrial membrane potential was monitored using Rhodamine 123.Release of cytochrome c from mitochondria to cytosol was detected by Western blotting.Activities of caspase-3,-8 and-9 were investigated by Caspase Activity Assay Kit.RESULTS:The viability of HepG2 cells treated by tectorigenin decreased in a concentration-and timedependent manner.The concentration that reduced the number of viable HepG2 cells by 50%(IC50)after 12,24 and 48 h of incubation was 35.72 mg/L,21.19 mg/L and 11.06 mg/L,respectively.However,treatment with tectorigenin at 20 mg/L resulted in a very slight cytotoxicity to L02 cells after incubation for 12,24 or 48 h.Tectorigenin at a concentration of 20 mg/L greatly inhibited the viability of HepG2 cells and induced the condensation of chromatin and fragmentation of nuclei.Tectorigenin induced apoptosis of HepG2 cells in a time-and dose-dependent manner.Compared with the viability rate,induction of apoptosis was the main mechanism of the anti-proliferation effect of tectorigenin in HepG2 cells.Furthermore,tectorigenininduced apoptosis of HepG2 cells was associated with the generation of reactive oxygen species,increased intracellular[Ca2+]i,loss of mitochondrial membrane potential,translocation of cytochrome c,and activation of caspase-9 and-3.CONCLUSION:Tectorigenin induces apoptosis of HepG2 cells mainly via mitochondrial-mediated pathway,and produces a slight cytotoxicity to L02 cells.

Plasma levels of acylated ghrelin in patients with functional dyspepsia

AIM:To investigate the relationship between plasma acylated ghrelin levels and the pathophysiology of functional dyspepsia.METHODS:Twenty-two female patients with functional dyspepsia and twelve healthy volunteers were recruited for the study.The functional dyspepsia patients were each diagnosed based on the Rome Ⅲ criteria.Eligible patients completed a questionnaire concerning the severity of 10 symptoms.Plasma acylated ghrelin levels before and after a meal were determined in the study participants using a commercial human acylated enzyme immunoassay kit;electrogastrograms were performed for 50 min before and after a standardized 10-min meal containing 265 kcal.RESULTS:There were no significant differences in plasma acylated ghrelin levels between healthy volunteers and patients with functional dyspepsia.However,in patients with functional dyspepsia,there was a negative correlation between fasting plasma acylated ghrelin levels and the sum score of epigastric pain(r =-0.427,P = 0.047) and a positive correlation between the postprandial/fasting plasma acylated ghrelin ratio and the sum score of early satiety(r = 0.428,P =0.047).Additionally,there was a negative correlation between fasting acylated ghrelin plasma levels and fasting normogastria(%)(r =-0.522,P = 0.013).Interestingly,two functional dyspepsia patients showed paradoxically elevated plasma acylated ghrelin levels after the meal.CONCLUSION:Abnormal plasma acylated ghrelin levels before or after a meal may be related to several of the dyspeptic symptoms seen in patients with functional dyspepsia.

Time-resolved laser-induced breakdown spectroscopy of aluminum

We develop a system to measure the elemental composition of unprepared samples using laser-induced breakdown spec-troscopy (LIBS) in our laboratory,which can be used for the determination of elements in solids,liquids and aerosols. A description of the instrumentation,including laser,sample chamber and detection,is followed by a brief discussion. The time-resolved LIBS of aluminum at atmospheric pressure is presented. At the end,the possibilities and later uses of this technique are briefly discussed.

Development of Multiple ELISAs for the Detection of Antibodies against Classical Swine Fever Virus in Pig Sera

The major immunogenic proteins （Ems, E2 and NS3） of classical swine fever virus （CSFV） （Shimen strain） were expressed in E. coli and purified by affinity chromatography. The recombinant antigens were applied to develop multiple enzyme-linked immunosorbent assays （ELISAs） for the detection of specific antibodies in pig sera. Optimum cut-off values were determined by receiver operating characteristic （ROC） analysis after testing 201 sera of vaccinated pigs and 64 negative sera of unvaccinated piglets. The multiple ELISAs were validated with 265 pig sera yielding high sensitivity and specificity in comparison with the virus neutralization results. The results demonstrated that multiple ELISAs can be a valuable tool for the detection of CSFV infection and serological surveys in CSFV-free countries or for the evaluation of the antibody responses in pigs induced by a live attenuated C-strain vaccination

Measuring Ca^(2+) influxes of TRPC1-dependent Ca^(2+) channels in HL-7702 cells with Non-invasive Micro-test Technique

AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a normal human liver cell line.METHODS： Net Ca^2＋ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPCl were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.RESULTS： Ca^2＋ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 （a non-selective Ca^2＋ channel blocker）; 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2＋ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION： In HL-7702 cells, there is a type of TRPCl-dependent Ca^2＋ channel, which could be detected v/a NMT and inhibited by La^3＋.

Screening of Surface Medication Agents and Modification Mechanism of Fly Ash

The fly ash from Jixi power plant was treated with various surface modifiers. The surface properties of the modified fly ash,including active index wetting angle,were measured in this paper. The modified fly ash was filled into rubber to improve the rubber properties. The results of rubber tests indicate that the type of the surface modifiers has a great influence on the rubber reinforcing properties. The fly ash modified by titanate coupling agents exhibits the best performance in respect to rubber reinforcing properties. The test results show that the fly ash can take place of some decomposition material so that the dosage of decomposition in rubber can be reduced,resulting in the low producing cost of rubber and the low pollution of fly ash.

Feasibility of a finger prick-based self-testing kit in first- and second-degree relatives of children with coeliac disease

AIM:To assess feasibility of a finger prick-based kit as method for self-testing of first and second-degree relatives of coeliac disease (CD) patients. METHODS:A total number of 379 subjects were invited to participate in this study,consisting of 197 first- degree and 182 second-degree relatives of CD patients. The self-testing kit (BiocardTM) was sent out with included instructions for use. Completed tests were sent back to the study coordinator for assessment. RESULTS:One hundred and ninety-six invited relatives carried out the BiocardTM test at home. Amongst these,70% were children. In 97% of the cases the test was performed correctly. Three tests revealed a positive result,all of which were later confirmed by serology and histology as coeliac disease.CONCLUSION:Our study indicates that BiocardTM test is a reliable,easy to use and well-accepted tool for home testing of first- and second-degree relatives of CD patients.

A new polymorphism in the GRP78 is not associated with HBV invasion

AIM:To examine the association between -86 bp(T>A) in the glucose-regulated protein 78 gene(GRP78) and hepatitis B virus(HBV) invasion.METHODS:DNA was genotyped for the single-nucleotide polymorphism by polymerase chain reaction followed by sequencing in a sample of 382 unrelated HBV carriers and a total of 350 sex-and age-matched healthy controls.Serological markers for HBV infection were determined by enzyme-linked immunosorbent as-say kits or clinical chemistry testing.RESULTS:The distributions of allelotype and genotype in cases were not significantly different from those in controls.In addition,our fi ndings suggested that neither alanine aminotransferase/hepatitis B e antigen nor HBV-DNA were associated with the allele/genotype variation in HBV infected individuals.CONCLUSION:-86 bp T>A polymorphism in GRP78 gene is not related to the clinical risk and acute exacerbation of HBV invasion.

Quantification of CrylAb Toxin in Bt Maize for Ostrinia nubilalis （Lep.： Crambidae） Bioassay

Two variants of diet composition were prepared to evaluate the susceptibility of ECBs to CrylAb toxin as follows： 1） 38-0600 Stonefly Heliothis Diet mixed with purified CrylAb protein and 2） 38-0600 Stonefly Heliothis Diet mixed with lyophylized leaves of Bt maize MON 810-YieldGard. A method of sample preparation and extraction of Bt toxin for reproducible ELISA quantification were optimized. The qualitative DAS-ELISA kit from Agdia was optimized for use in quantitative analysis of Cry lAb toxin. The mortality of ECB larvae from the laboratory strain on the diet with CrylAb toxin did not differ significantly from the mortality on the diet with Bt maize leaves with the same rate of Cry lAb toxin. Similarly, the mortality of the ECB larvae from the field population on the diet with Bt maize leaves did not differ significantly from the mortality of ECB larvae from the laboratory strain on the same type of diet. Therefore, the incorporation of Bt maize leaves into the diet did not influence the efficacy of CrylAb toxin against ECBs. Using this method, a susceptibility of one field population of ECBs from the Czech Republic to CrylAb toxin was determined （LC50 of 2.16 μg of Cry 1Ab g^-1 of diet）.

Detection of Acetyl-CoA Carboxylase （ACCase） Inhibitor Herbicides Resistance in Sterile Wild Oat （Avena sterilis L.） Using Agar Quick Test

This study was conducted using seeds in Petri dish containing agar medium in order to determine acetyl-CoA carboxylase （ACCase） herbicides resistance （R） in Avena sterilis that was grown in wheat fields at Adana province, Turkey. Seeds were collected from one large suspected field, where clodinafop-propargyl （Aryloxyphenoxypropionate “FOPs”） and pinoxaden （Phenylpyrazoline “DEN”） have been applied for many years. Susceptible （S） population was collected from the road side on the same region. Agar media of concentration 14 g/L was prepared and it was melted in microwave. Then the amount of 20 mL agar media was added into each Petri dish. Five seeds were placed on agar mediums containing discriminating dose of clodinafop and pinoxaden. Petri dishes were placed in growth incubator operating at 10 °C. After 15 d, both radicle and hypocotyl length were measured. The percentage of germinated seed and dose-response curves were determined. At these different concentration levels, there were more than 50% of R and less than 40% of S seed germinated for pinoxaden. However, for clodinafop, more than 60% of R and less than 50% of S seeds were germinated. At higher concentration levels, the populations of resistant and susceptible were not germinated for both herbicides. The resistance value of R population was then compared with that of the S biotype. From the resistance index （RI）, the population was more resistant to pinoxaden （7.43 for radicle and 2.47 for hypocotyl） than the clodinafop-propagyl （1.39 for radicle and 3.77 for hypocotyl）. The method provided a simple, quick and cost effective way to identify ACCase herbicides resistance in most grass weeds.

Effect of Eliminated the Breeding Pigs with Unqualified CSFV Antibody on Sows' Reproductive Performance and Pigs' Growth Performance

[Objective] The aim was to explore the effect of eliminated the breeding pigs with unqualified CSFV antibody on sow's reproductive performance and pig's growth performance so as to provide a scientific basis for the eliminating of the breeding pigs with unqualified CSFV antibody in large-scale pig farms.[Method] Serum samples from three scale pig farms were collected and tested with HerdChek CSFV-ELISA kit,then provided a certain scientific basis for scale pig farm to eliminate the unqualified(antibody blocking rate<50%)breeders after booster immunization.[Result ] After eliminating the breeding pigs with unqualified CSFV antibody,the average litter number of piglet in three pig farms(A,B,C)were increased by 0.29(P<0.05),0.40(P<0.01),0.39(P<0.01)respectively;the average number of survival piglets were increased by 0.54(P<0.01),0.35(P<0.01),0.62(P<0.01)respectively;the average litter number of weaned piglets were increased by 0.65(P<0.01),0.71(P<0.01),0.81(P<0.01)respectively.The difference in weight gain of piglet at 30-60 d of age was extremely significant(P<0.01),but inconspicuousness for the swine pregnancy rate,the survival rate of weaned piglet and piglet at 30-60 d of age.[Conclusion] The eliminating the breeding pigs with unqualified CSFV antibody can significantly improve the performance of breeder and piglets.

Circulating adiponectin: a potential prognostic marker for hepatocellular carcinoma

Objective: We planned this study to investigate the relation between serum adiponectin level and hepatocellular carcinoma (HCC): risk, features and prognosis. Methods: The study included 100 patients with HCC and 40 healthy control subjects. Adiponectin levels were determined by an enzyme-linked immunosorbent assay kit. Results: In the subset of patients with compensated cirrhosis, the mean serum adiponectin level was significantly lower in HCC cases compared to healthy controls (88.6 versus 115 ng/mL; P = 0.012). In addition, serum adiponectin levels correlated negatively with tumor size (P = 0.004) and were significantly lower in patients with vascular invasion and distant metastases (P = 0.03 and P = 0.02 respectively). Furthermore, the median overall survival was significantly higher in the high adiponectin group than the low adiponectin group (median 12.5 versus 9.5 months; log rank = 4.6, P = 0.03). Conclusion: Decreased circulating adiponectin level may play a role in the development of HCC and is a potential poor prognostic marker. These data should be validated in further prospective studies. Also the mechanisms by which adiponectin affect the course of HCC need to be clarified.