气相色谱串联质谱法测定鸡蛋中的三聚氰胺

建立了使用气相色谱串联质谱(GC/MS/MS)检测鸡蛋中三聚氰胺的分析方法,对鸡蛋试样中的三聚氰胺用三氯乙酸溶液超声提取,经混合型阳离子交换固相萃取柱净化,净化液用N,O-双三甲基硅基三氟乙酰胺(BSTFA)+三甲基氯硅(TMCS)进行硅烷化衍生,衍生产物采用多反应监测(MRM)质谱扫描模式,用化合物的保留时间和质谱碎片的丰度比定性,外标法定量。在0.005～1.0 mg/L范围内具有良好的线性关系,相关系数为0.9998。方法最低定量限为0.005 mg/kg,回收率范围为90%～110%,相对偏差小于10%。此方法样品前处理简单、定量限低、定性准确,适用于测定鸡蛋中的三聚氰胺。     

新型复合混凝吸附剂对无铅皮蛋废水的处理研究

针对皮蛋废水,采用化学混凝吸附法进行处理,实践表明,聚合氯化铝(PAC)具有非常好的废水处理效果,粉煤灰对废水中各污染物质也具有一定的去除作用,本实验所需絮凝剂采用聚合氯化铝(PAC),吸附剂采用锅炉厂废弃粉煤灰。通过正交试验讨论了PAC+粉煤灰混合制成的复合混凝吸附剂与PAM(+)联合处理皮蛋废水的较佳处理条件。结果表明,PAC与粉煤灰投加比为2:5配成新型混凝吸附药剂,投加量为50g/L,pH为6.5左右,搅拌时间约为14m in时,经处理后废水中COD去除率达81.25%,重金属离子Cu2+和Zn2+的去除率可分别达到92.1%和99.2%。     

新城疫病毒Lasota系疫苗生产中鸡胚孵化条件的优化

目的优化新城疫病毒Lasota系疫苗生产中鸡胚孵化条件。方法利用正交实验,对影响疫苗效价的鸡胚孵化温度、孵化湿度、照蛋时间间隔等3个因素进行优化。结果鸡胚最佳孵化条件为孵化温度36℃,孵化湿度55%,照蛋时间间隔2h。孵化湿度对疫苗效价有极显著影响,孵化温度和照蛋时间间隔有显著影响。应用优化的条件生产的疫苗,效价为10~(9.5)EID_(50)/0.1ml,明显高于原条件生产疫苗的平均效价10~(8.5)EID_(50)/0.1ml。结论采用优化的生产条件,可明显提高疫苗的效价。     

微波消化络合萃取-GFAAS测定松花蛋中微量铅

尝试建立新的分析方法,试样经微波消化后,络合萃取浓缩,在适当条件下采用石墨炉原子吸收法测定。测定结果在1～20μg/L范围内呈线性,RSD%为1.92%～3.45%,回收率为97.8%～101.5%。本方法测定松花蛋中微量铅简单、快速、安全、准确、选择性好。     

Quantification of Lipidomics Profiling using UPLC-QE-HESI- Lipid Analysis on the Salted Duck Egg Incorporated with Clove Extract

The salted egg yolks supplemented with clove extract are compared with the non-supplemented group, and subsequently the lipidomics profiles are characterized and identified by UPLC-QE-MS/MS in positive and negative ion modes respectively. A total of 315 lipids are detected in the control group and the clove extract treated group. In the positive ion mode, the 10 subclasses of glycerolipids in the treated samples are significantly different (p < 0.05). The lipid types with most varied compositions are triglyceride and ceramides, followed by CerG1 (glucosylceramide), LPE (lyso-phosphatidylethanolamine), diglyceride, and monosialodihexosyl ganglioside. In the negative ion mode, the authors identified 35 subclasses which are significantly different (p < 0.05), that include glycerolphospholipids, glycosphingolipids, and neutralglycosphingolipid. The lipid types with most varied compositions in negative mode are PE (phosphatidylethanolamine), followed by PC (phosphatidylcholine), LPC (lyso-phosphatidylcholine), and GM3 (monosialo-dihexosyl ganglioside). The contents of phosphatidylcholine, lyso-phosphatidylcholine, phosphatidylethanolamine, and monosialo-dihexosyl ganglioside in egg yolks treated with 0.5% (w/v) clove are significantly higher than those in the control group (p < 0.05), in which phosphatidylcholine and phosphatidylethanolamine are the main components of glycerolphospholipid. Practical Application : The lipidomics analyses of the salted egg yolk added with and without clove extract are compared to reveal the beneficial effect of clove extracts on the lipid profiles, and further exploring the types and relative content of the lipid components. A total of 315 lipids are detected in all samples. In the positive ion mode, the 10 subclasses of glycerolipids are found to be significantly different in the treated samples. In the negative ion mode, the lipid content of 35 subclasses are significantly different. From the nutrition fact value, salted duck egg enriched with clove extract can serve as one of the alternative egg products rich in essential lipids.     

Acute Toxicity of Dissolved Ozone to Eggs and Larvae of Selected Freshwater Fish Species

To prevent encroachment of undesirable fish species entrained in Connecticut River water diverted to the Quabbin Reservoir, the investigators determined levels of ozone and chlorine required to destroy all larvae and eggs of selected test organisms within 48 hours. The oxidant exposure duration of three hours was chosen to reflect the transit time of the diverted water from the Northfield impoundment to Quabbin. The experimental design reflected both in-line and contact chamber modes of oxidant administration.     

Urban wastewater disinfection by filtration technologies

The microbiological quality of effluents from different macrofiltration systems (pressure sand filter and disc filter) used as pre-treatment and membrane technologies (microfiltration and ultrafiltration) was evaluated in order to determine their possible application as alternatives to disinfection of urban wastewater prior to reutilization. Microbiological quality was determined by reference to nematode egg content, fecal coliforms, E. coli and somatic coliphages. Pathogenic nematode eggs were efficiently retained by the macrofiltration systems. However, since other types of nematode eggs were present in the effluents treated by both systems, the possibility of such infective agents appearing after this type of treatment cannot be discounted. The membrane technologies proved highly efficient at retaining micro-organisms, achieving effluents of excellent microbiological quality. However, the effluents could not be classified as sterile, since contamination of permeation zones gave rise to the presence of micro-organisms. This result casts doubt on the validity of using the fecal coliform indicator to assess microbiological quality of effluents from these systems. Differences between the two membrane technologies were noted with regard to viral particle retention capacity, with only the ultrafiltration module achieving effluents with total absence of fecal contamination indicators. The macrofiltration systems may present problems when used as pre-treatments to standard disinfection systems (UV radiation, reactive oxidant disinfection). Such problems do not arise with the membrane technologies, which offer a valid alternative for the disinfection of urban wastewater prior to reutilization.     

Calcium Signaling and Meiotic Exit at Fertilization in Xenopus Egg

Calcium is a universal messenger that mediates egg activation at fertilization in all sexually reproducing species studied. However, signaling pathways leading to calcium generation and the mechanisms of calcium-induced exit from meiotic arrest vary substantially among species. Here, we review the pathways of calcium signaling and the mechanisms of meiotic exit at fertilization in the eggs of the established developmental model, African clawed frog, Xenopus laevis. We also discuss calcium involvement in the early fertilization-induced events in Xenopus egg, such as membrane depolarization, the increase in intracellular pH, cortical granule exocytosis, cortical contraction, contraction wave, cortical rotation, reformation of the nuclear envelope, sperm chromatin decondensation and sister chromatid segregation.     

Lipidomic Profiling Reveals the Effect of Egg Components on Nonalcoholic Steatosis in HepG2 Cells and Its Involved Mechanisms

Non‐alcoholic fatty liver disease (NAFLD) is a major cause of cardiovascular disease. The relationship between egg consumption and NAFLD is still controversial for its high cholesterol content. In this study, the effects of different egg components (egg white (EW), egg yolk (EY), and whole egg (WE)) on NAFLD are examined using oleic acid (OA)‐induced HepG2 cells with UPLC‐ESI‐MS/MS approach. The results show EY could affect the lipid profile effectively by increasing phosphocholine (PC), phosphatidylglycerol (PG), and carnitine (CAR). Orthogonal projections to latent structures?discriminate analysis (OPLS‐DA) combine with S‐plot analysis select 10, 82, and 20 potential biomarkers in EW, EY, and WE group, respectively. Up‐regulated TG, DG, and down‐regulated lysophosphatidylcholines (lysoPC), lysophosphatidylethanolamine (lysoPE) biomarkers are found in EY group, while down‐regulated TG and FFA are found in EW and WE group. Glycerolipid and choline metabolism are the most involved pathways affected by EY and WE. In addition, the mechanism is associated with the expression of Pla2g15, Pnpla6‐1, Gad1, and involved lipogenic genes ABC1 and PPARα. This study suggests that WE treatment can ameliorate OA‐induced hepatic steatosis by inhibiting TG accumulation, while EY seems slightly accelerate hepatic steatosis. Furthermore, the effects are closely associated with its effects on glycerolipid metabolism. Practical applications: Nonalcoholic fatty liver disease (NAFLD) is a worldwide disease, while the associations between egg consumption and NAFLD are still poorly understood. This study investigates the effects of egg components on NAFLD in oleic acid (OA)‐induced HepG2 cells based on a targeted lipidomics approach. The results indicate that WE (whole egg) treatment could ameliorate OA‐induced hepatic steatosis by inhibiting TG and FFA accumulation, which is closely associated with glycerolipid metabolism. The results provide knowledge and understanding of the effects of egg on NAFLD and involved mechanism, and further provided nutritional guidelines for egg consumption.     

HS-SPME结合GC-MS分析煎鸡蛋的挥发性风味成分

采用顶空固相微萃取与GC-MS联用方法对煎鸡蛋中挥发性成分进行提取与分析,考察萃取头、萃取温度和吸附时间对分析结果的影响,得到优化的顶空固相微萃取条件为:黑色萃取头(75μm Carboxen/PDMS),吸附温度75℃,吸附时间70 min。在优化的条件下分析,共鉴定出50种挥发性风味成分,其中,醛类16种(40.588%)、含氮化合物14种(23.639%)、醇类8种(7.156%)、烃类3种(4.800%)、酚类及杂环化合物3种(1.755%)、酮类3种(0.868%)及含硫化合物3种(0.563%)。鉴定出含量较高(相对质量分数大于2.5%)的物质有:2,5-二甲基吡嗪、3-甲基丁醛、2-甲基吡嗪、壬醛、苯甲醛、反,反-2,4-癸二烯醛、辛醛、2-甲基丁醛、反-2-癸烯醛、3,7-二甲基-1,6-辛二烯、1-辛烯-3-醇。     

Defensive Components in Insect Eggs: Are Anthraquinones Produced during Egg Development?

Eggs of several insect species are protected against natural enemies by noxious components. However, almost nothing is known about the fate of these defensive substances during egg development nor their site of biosynthesis. The eggs of several leaf beetle species of the taxon Galerucini contain components that are unusual in insects: 1,8-dihydroxylated anthraquinones and anthrones that deter predators such as ants and birds. These components, i.e., the anthrones dithranol and chrysarobin, and the anthraquinones chrysazin and chrysophanol, are not sequestered from host plants. We asked whether the amounts of these components in the overwintering eggs of Galeruca tanaceti change from deposition to larval hatching. Gas chromatography-mass spectroscopy (GC-MS) analyses of eggs revealed a significant decrease in total amounts of dithranol and chrysophanol from egg deposition in autumn to the next spring 5 months later. Thus, these results do not provide any hint of active anthraquinone biosynthesis within eggs. Instead, the anthrones and anthraquinones that must be incorporated by the female into the eggs seem to be degraded to some extent either by the embryo or endosymbionts. GC-MS analyses showed that parasitization of eggs had some effects on the quantities of anthrones and anthraquinones.     

2,6-Dichlorophenol in the tickRhipicephalus appendiculatus Neumann

Certain olfactory cells of maleRhipicephalus appendiculatus Neumann are known to be stimulated by 2,6-dichlorophenol.R. appendiculatus has been reexamined for the presence of 2,6-dichlorophenol, and it has been detected in both male and female adults. Unfed females contain 12 ng/ tick, declining to 2 ng/tick after six days of feeding, while unfed males contain 2 ng/tick, falling to 0 after feeding. Larval tick extracts which are also known to stimulate 2,6-dichlorophenol-sensitive cells were examined and found to contain this phenol, whereasR. appendiculatus eggs did not contain this compound.     

Defensive adaptations of eggs and adults ofGastrophysa cyanea (Coleoptera: Chrysomelidae)

Egg clusters and adults ofGastrophysa cyanea are conspicuous and, like their larvae, are chemically protected. The eggs owe their bright yellow color primarily to -carotene and, in addition, contain substantial quantities of oleic acid. At natural concentrations oleic acid effectively deters many species of ants from feeding. The use of fatty acids as deterrents against ants is discussed as a possible widespread phenomenon among insects. During defensive confrontations, adults ofG. cyanea exhibit avoidance behavior and may also feign death. In addition, the adults may autohemmorhage or secrete a fluid from elytral or pronotal pores in response to traumatic stimuli. The secretions are effective against ants and contain a mixture of hydrocarbons as well as terpenoid components. The pattern of ontogenetic modification in the defensive chemical repertoire ofG. cyanea is discussed.     

Effects of urea analogs on egg hatching and movement of unhatched larvae of monogenean parasiteAcanthocotyle lobianchi from skin ofRaja montagui

Rapid hatching in the monogenean parasiteAcanthocotyle lobianchi from the skin ofRaja montagui is stimulated by urea. Structurally similar to the urea molecule, the following analogs of urea provide amino groups, carboxyl groups, or combinations of these, but fail to stimulate hatching at concentrations of 1 mM in seawater: methylurea (MU); 1, 3-dimethylurea (DU); 1, 1, 3, 3-tetramethylurea (TMU); thiourea (TU); 1, 1, 3, 3-tetramethyl-2-thiourea (TMTU); and 1-phenyl-2-thiourea (PTU). All of these analogs except PTU elicit movements of unhatched larvae, and posttreatment of the eggs with urea showed that the ability to hatch is not impaired by initial treatment with any of the urea analogs. Thus the larval chemoreceptor that initiates hatching appears to be highly specific for the urea molecule.     

Anthraquinones in different developmental stages ofGaleruca tanaceti (Coleoptera,Chrysomelidae)

The overwintering eggs and the larvae of the leaf beetleGaleruca tanaceti (L.) contain hydroxylated anthraquinones. In both developmental stages, l,8-dihydroxy-3-methylanthraquinone (= chrysophanol) and 1,8-di-hydroxyanthraquinone (= chrysazin) were detected by GC-MS and GC-FTIR analyses. In the eggs, chrysazin was found only in traces. Anthraquinones were also present in ovaries and hemolymph of gravid females, which were investigated in order to examine the incorporation of these substances into the eggs. Neither in acidified nor in nonacidified extracts of the host plantsTanacetum vulgäre L. andAchillea millefolium L. were anthraquinones found. The activity of these anthraquinones as chemical defense substances was proved in bioassays with the antMyrmica ruginodis NYL. Further possible biological significances of anthraquinones are discussed.     

Effects of Geldanamycin on Hatching and Juvenile Motility in <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis> and <Emphasis Type="Italic">Heterodera glycines</Emphasis>

Several Streptomyces species are known to produce metabolites that inhibit plant pathogens. One such compound is geldanamycin (GA), a benzoquinone ansamycin originally isolated from Streptomyces hygroscopicus. We examined the effect of geldanamycin on egg hatch and juvenile motility in Caenorhabditis elegans and in two populations of the plant-parasitic nematode Heterodera glycines. When C. elegans eggs were exposed to geldanamycin, both hatch and motility were reduced by GA doses between 2 and 50 μg/ml. The H. glycines inbred populations TN17 and TN18 exhibited low dose stimulation of hatch and motility, whereas levels occurring at higher GA doses were at or below control levels. These experiments represent the first demonstration of geldanamycin effects in C. elegans and H. glycines and suggest that the heat shock chaperone Hsp90, the known molecular target of geldanamycin, may be involved in nematode egg hatch and motility. This study also indicates that geldanamycin-producing strains of Streptomyces may be useful as biocontrol agents for nematodes.     

Effects of Peruvian Maize Extracts on Growth, Development, and Fecundity of the European Corn Borer

Twelve Peruvian maize, Zea mays, accessions were selected because of their relatively high level of field resistance to first-generation European corn borer (ECB), Ostrinia nubilalis, larval leaf-feeding. Water extracts of freeze-dried, powdered, leaf tissue were incorporated into a standard ECB diet, fed to larvae, and the effects on larval growth, development, and fecundity were measured. Larval and pupal weights were monitored as were the time elapsed in the larval, pupal, and adult stages. Adult fecundity and egg fertility were recorded. The experiment was a randomized block design (larvae and pupae) or a completely randomized design (adults) and analyzed with ANOVA ( = 0.05). Pairwise comparisons were made between groups of insects grown on diets containing extracts from the Peruvian lines, a standard diet, or diets containing extracts of a known susceptible inbred, and a known resistant inbred line. Survival was analyzed with a chi-squared test ( = 0.05). Two Peruvian accessions significantly reduced female larval and pupal weights, extended pupal and adult development time, and decreased survival of pupae and adults. Water extracts also had a pronounced impact on males; two accessions significantly reduced pupal weight and extended the time required to pupate, and one reduced male survival to adults. The results indicate that water-soluble factors from resistant Peruvian accessions inhibit the growth, developmental time, and survival of ECB. These resistance factors could be useful in the development of maize germplasm with insect-resistant traits.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.