A new species of Microplitis Foerster 1862:Microplitis vitellipedis,sp.nov.(♀) is described from China,Fujian,Mt.Wuyi.The new species is similar to Microplitis changbaishana Song et Chen.but has the following diff...A new species of Microplitis Foerster 1862:Microplitis vitellipedis,sp.nov.(♀) is described from China,Fujian,Mt.Wuyi.The new species is similar to Microplitis changbaishana Song et Chen.but has the following differences:Microplitis vitllivipes sp.nov:T1 parallel or subparallel-sided;antennae with F12-15 loosely connected;hind coxae reddish yellow;body normal.Microplitis changbaishana Song et Chen:T1 slightly widened towards apex;antennae with F12-15 tightly connected;hind coxae yellowish beown;body stout.展开更多
A gene encoding a novel G protein β subunit of β1 subclass, GβMmed was isolated from Microplitis mediator (Hymenoptera: Braconidae). The full-length sequence of GβMmed is 1 119 bp, the cDNA contains a 1 023 bp...A gene encoding a novel G protein β subunit of β1 subclass, GβMmed was isolated from Microplitis mediator (Hymenoptera: Braconidae). The full-length sequence of GβMmed is 1 119 bp, the cDNA contains a 1 023 bp open reading frame that encodes a protein with 340 amino acids, and the predicted molecular weight of GβMmed is 37.23 kDa and isoelectric point is 5.86. By the quantitative real-time RT-PCR method, the tissue-specific expression and quantitative changes in the developmental expression profile of GβMmed were detected. It was found that GβMmed was abundantly expressed in M. mediator antennae, head (without antennae), thorax, abdomen, legs and the wings, and especially at high levels in abdomen. In antennae, expression varied through 1st day before emergence to 5-d-old adults, and had equal expression levels detected in females and males in total. In head, GβMmed expresses while initially high in females, and have another peaked in stage 4 and 1st day, in males showed a peak of GβMmed expression prior to emergence and relatively low levels after emergence. In female abdomen GβMmed expression levels have two peaks in stage 1 and the 5th d, but just have one peak in male abdomen in stage 1. In all other tissues expression was low and stable.展开更多
Sex pheromones are considered to play critical roles in partner communication of most parasitic Hymenoptera.However,the identification of sex pheromone components remains limited to a few families of parasitoid wasps....Sex pheromones are considered to play critical roles in partner communication of most parasitic Hymenoptera.However,the identification of sex pheromone components remains limited to a few families of parasitoid wasps.In this study,we functionally characterized a candidate sex pheromone component in Microplitis mediator(Hymenoptera:Braconidae),a solitary parasitoid of Noctuidae insects.We found that the body surface extract from female wasps could significantly stimulate courtship behavior of males.Gas chromatography-electroantennographic detection(GC-EAD)analysis revealed that a candidate semiochemical from extract triggered significant electrophysiological response of antennae of males.By performing gas chromatography-mass spectrometer(GC-MS)measurement,GC-EAD active compound was identified as n-octyl acrylate,a candidate sex pheromone component in female M.mediator.In electroantennogram(EAG)tests,antennae of male wasps showed significantly higher electrophysiological responses to n-octyl acrylate than those of females.Y-tube olfactometer assays indicated that male wasps significantly chose n-octyl acrylate compared with the control.Furthermore,male wasps showed a remarkable preference for n-octyl acrylate in a simulated field condition behavioral trial;simultaneously,n-octyl acrylate standard could also trigger significant courtship behavior in males.We propose that n-octyl acrylate,as a candidate vital sex pheromone component,could be utilized to design behavioral regulators of M.mediator to implement the protection and utilization of natural enemies.展开更多
Peptidoglycan recognition proteins (PGRPs) are a family of innate immune receptors that specifically recognize peptidoglycans (PGNs) on the surface of a number of pathogens. Here, we have identified and characteri...Peptidoglycan recognition proteins (PGRPs) are a family of innate immune receptors that specifically recognize peptidoglycans (PGNs) on the surface of a number of pathogens. Here, we have identified and characterized six PGRPs from endoparasitoid wasp, Microplitis mediator (MmePGRPs). To understand the roles of PGRPs in parasitoid wasps, we analyzed their evolutionary relationship and orthology, expression profiles during different developmental stages, and transcriptional expression following infection with Gram-positive and -negative bacteria and a fungus. MmePGRP-S1 was significantly induced in response to pathogenic infection. This prompted us to evaluate the effects of RNA interference mediated gene specific knockdown ofMmePGRP-S1. The knockdown of MmePGRP-S1 (iMmePGRP-S1) dramatically affected wasps' survival following challenge by Micrococcus luteus, indicating the involvement of this particular PGRP in immune responses against Gram-positive bacteria. This action is likely to be mediated by the Toll pathway, but the mechanism remains to be determined. MmePGRP-S 1 does not play a significant role in anti-fungal immunity as indicated by the survival rate of iMmePGRP-S wasps. This study provides a comprehensive characterization of PGRPs in the economically important hymenopteran species M. mediator.展开更多
Sensory neuron membrane proteins(SNMPs),homologs of the human fatty acid transport protein CD36 family,are observed to play a significant role in chemoreception,especially in detecting sex pheromone in Drosophila and ...Sensory neuron membrane proteins(SNMPs),homologs of the human fatty acid transport protein CD36 family,are observed to play a significant role in chemoreception,especially in detecting sex pheromone in Drosophila and some lepidopteran species.In the current study,two full‐length SNMP transcripts,MmedSNMP1 and MmedSNMP2,were identified in the parasitoid Microplitis mediator(Hymenoptera:Braconidae).Quantitative real‐time polymerase chain reaction analysis showed that the expression of MmedSNMP1 was significantly higher in antennae than in other tissues of both sexes.In addition,the MmedSNMP1 transcript was increased dramatically in newly emerged adults and there were no significant differences between adults with or without mating and parasitic experiences.However,compared with MmedSNMP1,the expression of MmedSNMP2 was widely found in various tissues,significantly increased at half‐pigmented pupae stage and remained at a relatively constant level during the following developmental stages.It was found that MmedSNMP1 contained eight exons and seven introns,which was highly conserved compared with other insect species.In situ hybridization assay demonstrated that MmedSNMP1 transcript was distributed widely in antennal flagella.Among selected chemosensory genes(odorant binding protein,odorant receptor,and ionotropic receptor genes),MmedSNMP1 only partially overlapped with MmedORco in olfactory sensory neurons of antennae.Subsequent immunolocalization results further indicated that MmedSNMP1 was mainly expressed in sensilla placodea of antennae and possibly involved in perceiving plant volatiles and sex pheromones.These findings lay a foundation for further investigating the roles of SNMPs in the chemosensation of parasitoids.展开更多
MicroRNAs(miRNAs),a class of non-coding single-strand RNA molecules encoded by endogenous genes,are about 21–24 nucleotides long and are involved in the post-transcriptional regulation of gene expression in plants an...MicroRNAs(miRNAs),a class of non-coding single-strand RNA molecules encoded by endogenous genes,are about 21–24 nucleotides long and are involved in the post-transcriptional regulation of gene expression in plants and animals.Generally,the types and quantities of miRNAs in the different tissues of an organism are diverse,and these divergences may be related to their specific functions.Here we have identified 296 known miRNAs and 46 novel miRNAs in the antennae of the parasitoid wasp Microplitis mediator by high-throughput sequencing.Thirty-three miRNAs were predicted to target olfactory-associated genes,including odorant binding proteins(OBPs),chemosensory proteins,odorant receptors(ORs),ionotropic receptors(IRs)and gustatory receptors.Among these,17 miRNAs were significantly highly expressed in the antennae,four miRNAs were highly expressed both in the antennae and head or wings,while the remaining 12 miRNAs were mainly expressed in the head,thorax,abdomen,legs and wings.Notably,miR-9a-5p and miR-2525-3p were highly expressed in male antennae,whereas miR-1000-5p and novel-miR-13 were enriched in female antennae.The 17 miRNAs highly expressed in antennae are likely to be associated with olfaction,and were predicted to target one OBP(targeted by miR-3751-3p),one IR(targeted by miR-7-5p)and 14 ORs(targeted by 15 miRNAs including miR-6-3p,miR-9a-5p,miR-9b-5p,miR-29-5p,miR-71-5p,miR-275-3p,miR-1000-5p,miR-1000-3p,miR-2525-3p,miR-6012-3p,miR-9719-3p,novel-miR-10,novel-miR-13,novel-miR-14 and novel-miR-28).These candidate olfactory-associated miRNAs are all likely to be involved in chemoreception through the regulation of chemosensory gene expression in the antennae of M.mediator.展开更多
This work develops a Hermitian C^(2) differential reproducing kernel interpolation meshless(DRKIM)method within the consistent couple stress theory(CCST)framework to study the three-dimensional(3D)microstructuredepend...This work develops a Hermitian C^(2) differential reproducing kernel interpolation meshless(DRKIM)method within the consistent couple stress theory(CCST)framework to study the three-dimensional(3D)microstructuredependent static flexural behavior of a functionally graded(FG)microplate subjected to mechanical loads and placed under full simple supports.In the formulation,we select the transverse stress and displacement components and their first-and second-order derivatives as primary variables.Then,we set up the differential reproducing conditions(DRCs)to obtain the shape functions of the Hermitian C^(2) differential reproducing kernel(DRK)interpolant’s derivatives without using direct differentiation.The interpolant’s shape function is combined with a primitive function that possesses Kronecker delta properties and an enrichment function that constituents DRCs.As a result,the primary variables and their first-and second-order derivatives satisfy the nodal interpolation properties.Subsequently,incorporating ourHermitianC^(2)DRKinterpolant intothe strong formof the3DCCST,we develop a DRKIM method to analyze the FG microplate’s 3D microstructure-dependent static flexural behavior.The Hermitian C^(2) DRKIM method is confirmed to be accurate and fast in its convergence rate by comparing the solutions it produces with the relevant 3D solutions available in the literature.Finally,the impact of essential factors on the transverse stresses,in-plane stresses,displacements,and couple stresses that are induced in the loaded microplate is examined.These factors include the length-to-thickness ratio,the material length-scale parameter,and the inhomogeneity index,which appear to be significant.展开更多
Adult size, longevity, egg load dynamics and oviposition ofMicroplitis rufiventris Kok. which began their development in the first, second, third (preferred hosts) or fourth (non-preferred hosts) instar larvae of ...Adult size, longevity, egg load dynamics and oviposition ofMicroplitis rufiventris Kok. which began their development in the first, second, third (preferred hosts) or fourth (non-preferred hosts) instar larvae of Spodoptera littoralis (Boisd.) were studied. The parasitoid size was largely determined by the initial host size at parasitism. Non-ovipositing females derived from older hosts lived for longer periods than those derived from younger ones. However, the ovipositing females, irrespective of their size, lived for almost the same periods. At emergence, the oviducts of adult females contain a significant amount of mature eggs available for oviposition for a few hours on eclosion day. Egg load increases during the early phase of adult life. The amount of additional mature eggs and rate of egg maturation per hour was greater for wasps derived from preferred hosts compared with those in females derived from non-preferred hosts. The pattern of egg production in M. rufiventris females depended on the availability of hosts for parasitization. Host-deprived females depleted the egg complement with aging; the longer the host deprivation, the lower the oviduct egg load. Marked reduction in both realized or potential fecundity of host-deprived females was observed following host availability. Host privation for more than 3 days induced a marked deficit fecundity pattern through the female' s life. The realized fecundity was determined by the interaction among host availability, the number of eggs that are matured over the female' s life span, oviposition rate and host size from which the female was derived. These results suggest that: (i) M. rufiventris wasp is a weak synovigenic species; (ii) the maturation of additional eggs is inhibited once the maximum oviduct egg load is reached; (iii) the egg load of the newly emerged female is significantly less than the realized fecundity; and (iv) because M. rufiventris females oviposit fewer eggs when they begin depleting their egg supply at 3 days, augmentative releases will require release immediately following emergence to ensure the highest parasitization rate in the field.展开更多
Tin halide perovskites recently have attracted extensive research attention due to their similar electronic and band structures but non-toxicity compared with their lead analogues. In this work, we prepare high-qualit...Tin halide perovskites recently have attracted extensive research attention due to their similar electronic and band structures but non-toxicity compared with their lead analogues. In this work, we prepare high-quality CsSnX_(3)(X=Br,I) microplates with lateral sizes of around 1–4 μm by chemical vapor deposition and investigate their low-temperature photoluminescence(PL) properties. A remarkable splitting of PL peaks of the CsSnBr_(3)microplate is observed at low temperatures. Besides the possible structural phase transition at below 70 K, the multi-peak fittings using Gauss functions and the power-dependent saturation phenomenon suggest that the PL could also be influenced by the conversion from the emission of bound excitons into free excitons. With the increase of temperature, the peak position shows a blueshift tendency for CsSnI_(3), which is governed by thermal expansion. However, the peak position of the CsSnBr3microplate exhibits a transition from redshift to blueshift at ~160 K. The full width at half maximum of CsSnX_(3)broadens with increasing temperature, and the fitting results imply that longitudinal optical phonons dominate the electron–phonon coupling and the coupling strength is much more robust in CsSnBr3than in CsSnI_(3). The PL intensity of CsSnX_(3)microplates is suppressed due to the enhanced non-radiative relaxation and exciton dissociation competing with radiative recombination. According to the Arrhenius law, the exciton binding energy of CsSnBr_(3)is ~38.4 meV, slightly smaller than that of CsSnI_(3).展开更多
During the Paleozoic, the Ordos area in the western North China Plate was located at the intersecting position of microplates and controlled by their interaction. The structural framework in the Ordos area, which unde...During the Paleozoic, the Ordos area in the western North China Plate was located at the intersecting position of microplates and controlled by their interaction. The structural framework in the Ordos area, which underwent transformations in the Ordovician, the Carboniferous and the Permian respectively, was dominated by the alternation of uplift and depression. The transformations of structural framework are utilized as the clues to investigate the microplates' interacting type and its response in the Ordos area. According to the regional structural evolution, the Ordos area is simplified into an isopachous, isotropic and elastic shell model, and under proposed various boundary conditions, three series of numerical simulations corresponding to the three structural transformations are carried out to determine the detailed tectonic constraints. Numerical simulations reveal that the structure of the uplift and depression, which is similar to the actual pattern, develops only under one special boundary condition in each of the three series, indicating that the structural framework responds to the unique tectonic background. The simulation results show that in the Early Paleozoic, the L-shaped paleouplift formed nearby the southwestern corner of the Ordos area because the intensity of the compressions in the southern and western boundaries resulting from the ocean-continent collisions was similar. In the Late Paleozoic, it evolved into continent-continent (or arc-continent) interaction in the southern and northern boundaries; in the preliminary stage of the interaction, since the interface between the North China Plate and the plates on the south and north was narrow, the relative acting force was little and the regional western boundary immobile, and the structural framework in the basin was characterized by the N-S trending slender-waist-shaped uplift; as the interface between the plates expanded gradually, the extrusive force in the southern and northern boundaries of the North China Plate increased, resulting in the paleogeographic divisions showing E-W trending, and, the western boundary of the basin was extruded westward due to the intense compression inducing the local NE trending of paleogeographic division in the central area. The simulation results further reflect that the symmetry of the uplift-depression pattern is restricted by that of the boundary conditions, suggesting that the Paleozoic structural transformations of the Ordos area under boundary constraints accord with the universal physical symmetrical principle.展开更多
A new method for the determination of antithrombotic activity of egg white protein hydrolysate (EWPH) was developed using a microplate reader. Reaction was carried out at 37℃and pH 7.2 with fibrinogen concentration...A new method for the determination of antithrombotic activity of egg white protein hydrolysate (EWPH) was developed using a microplate reader. Reaction was carried out at 37℃and pH 7.2 with fibrinogen concentration 0.1%. Microplate reading was conducted at 405 nm. Inhibition rate of EWPH on thrombin activity showed linearity (R2 = 0.9971), when the inhibition rate was in the range of 10-90%. The lower limit of detection (LLD, at 99.7% probability) and the biological limit of detection (BLD, at 99.7% probability) of the method were 10.643 and 40 mg/mL, respectively. The repeatability standard deviation (R.S.D.) was 1.08%. The standard deviation of the method was ±0.027 AT-U.展开更多
A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble ph...A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble phosphorus (WSP),diluted calcium chloride extractable phosphorus (PCaCl2), and Olsen-P in the sediments of Taihu Lake, China, where potential P release in response to pH was analyzed. MPA for rapid P analysis was shown to be promising when applied on samples of natural water and sediment extracts. Concentrations of WSP and PCaCl2 in the sediments were much lower than those of Olsen-P. Olsen-P levels in the littoral sediments along the north coast of Meiliang Bay in Taihu Lake (80to 140 mg kg-1) were much higher than those in the mouth of the bay (less than 50 mg kg-1). The risk of P release in the mouth area of Meiliang Bay was lower than that in the north littoral zone with a risk of sediment P release induced by pH increases.展开更多
Objective: To identify the impact of lamivudine on HBV e antigen (HBeAg) seroconversion and HBV DNA level, and the appearance of Tyr-Met-Asn-Asp (YMDD) resistants. Methods: Forty-seven hepatitis B patients were trea- ...Objective: To identify the impact of lamivudine on HBV e antigen (HBeAg) seroconversion and HBV DNA level, and the appearance of Tyr-Met-Asn-Asp (YMDD) resistants. Methods: Forty-seven hepatitis B patients were trea- ted with oral lamivudine. ALT level and HBeAg were detected in the treatment on the zero, 3rd, 6th and 9th month respectively. The levels of HBV DNA and YMDD resistants were analyzed with PCR mi- croplate hybridization-ELISA. Results: After 9 months of treatment, HBV DNA be- came negative and ALT level was normal in 74% pa- tients. Among these patients, 17% patients had HBeAg converted to negative and anti-HBe antibody positive, whereas another 15% patients showed HBeAg negative. YMDD resistants appeared in 19 % patients (9/47). One, three and five resistants were detected in the treatment on the 3rd, 6th and 9th month respectively. Conclusions: Most HBV DNA in serum became nega- tive after 9 months of treatment, and the rate of HBeAg seroconversion was 17% (HBV DNA level was lower than 100 pg/ml before treatment). YMDD resistants appeared in 19% patients.展开更多
[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and...[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and provide experimental basis for the development of medicinal resources of P. ramosissimus. [Methods] The ultrasonic extraction method was adopted and orthogonal design was carried out to study the effects of ethanol concentration( A),ultrasonic time( B),the solid-to-liquid ratio( C) on the extraction of flavonoids from leaves of P. ramosissimus. The Microplate Reader was used to measure the content of flavonoids in leaves of P. ramosissimus. in different extraction conditions,P. ramosissimus. and the optimal extraction conditions were used to measure the content of flavonoids from leaves of P. ramosissimus.[Results]Effects of the ultrasonic extraction method on the extraction rate of flavonoids from leaves of P. ramosissimus: extraction times >ethanol concentration > Ultrasound time > solid-liquid ratio. The screened optimal extraction process was: ethanol concentration of 65%,the solid-to-liquid ratio of 1∶ 25,ultrasonic time of 2 h and extraction times Under this condition,the extraction rate of total flavonoids in leaves of P. ramosissimus. was 2. 56%. [Conclusions] This method is simple and feasibility,reliable,and suitable for rapid measurement with large samples.展开更多
Crop residue is a major source of soil organic matter;therefore,application of crop straw to soil contributes to the sustainable development of organic agriculture.To better understand the transformation of crop straw...Crop residue is a major source of soil organic matter;therefore,application of crop straw to soil contributes to the sustainable development of organic agriculture.To better understand the transformation of crop straw in orchard soils,we investigated the relationship between the characteristics of straw decomposition and functional diversity of associated microbial communities in a long-term peach orchard,China.Mesh bags,each containing 30 g of corn or bean straw,were buried at a soil depth of 20 cm in a 12-year-old peach orchard for 360 d(October 2011–October 2012).Three treatments were applied,i.e.,fresh corn straw,fresh corn straw with nitrogen fertilizer(urea,10.34 g/kg),and fresh bean straw.Changes in straw residual rate,straw water content and soil conditions were monitored after treatment.The functional diversity of straw-associated microbial communities was analyzed by the Biolog-Eco microplate assay.During the decomposition process,straw residual rates did not vary considerably from 10 d(30.4%–45.4%)to 360 d(19.0%–30.3%).Irrespective of nitrogen addition,corn straw decomposed faster than bean straw.Corn straw with nitrogen fertilizer yielded the highest average well color development(AWCD)values(1.11–1.67),followed by corn straw(1.14–1.68)and bean straw(1.18–1.62).Although the AWCD values did not differ significantly among the three treatments,substantial differences occurred across various time periods of the decomposition process(P<0.01).In terms of carbon source utilization,the dominant microbial groups fed mainly on saccharides.Hard-to-decompose substances gradually accumulated in the middle and late stages of straw decomposition.Of the six categories of carbon sources tested,the utilization rate of aromatics was the lowest with corn straw,whereas that of polymers was the lowest with bean straw.Among different treatments,straw residual rate was negatively correlated to soil available phosphorous,soil available potassium and soil temperature(P<0.05),but not to soil water content.In some cases(corn straw with or without nitrogen fertilizer),straw residual rate was negatively correlated to straw water content,amino acid utilization and carboxylic acid utilization,and positively correlated with microbial species richness and evenness(P<0.05).Microbial community associated with corn and bean straw decomposition in soil was respectively dominated by aromatic-and polymer-metabolizing groups during the middle and late stages of this process,which could reduce the stability of microbial community structure and decrease the rate of straw decomposition in the fruit tree orchard.展开更多
Hydrothermal plume is an important constituent of seabed hydrothermal circulation and is also one of the characteristics of active hydrothermal vents. Portable Miniature Autonomous Plume Recorders (MAPR) attached to...Hydrothermal plume is an important constituent of seabed hydrothermal circulation and is also one of the characteristics of active hydrothermal vents. Portable Miniature Autonomous Plume Recorders (MAPR) attached to a towed deep-sea instrument was used to search for hydrothermal plumes and hydrothermal vents. We introduced the basic principle of MAPR based on deep towing technology to detect plumes, then analyzed the factors affecting the quality of the MAPR data and presented a data correction method for MAPR, including instrument location correction, noise reduction processing, system error elimination and seawater background reduction. Finally we applied the method to analyze MAPR data obtained during the Chinese DY115-21 cruise on R/VDayang Iin the “Precious Stone Mountain” hydrothermal field on the Gala-pagos Microplate. The results provided a better understanding of the distribution of the hydrothermal activ-ity in this field, indicating the presence of a new hydrothermal vent.展开更多
To investigate the feasibility of using free fetal DNA from maternal plasma as the source of fetal material in non invasive prenatal diagnosis, SRY gene of free DNA in maternal blood of 65 samples were analyzed by us...To investigate the feasibility of using free fetal DNA from maternal plasma as the source of fetal material in non invasive prenatal diagnosis, SRY gene of free DNA in maternal blood of 65 samples were analyzed by using primer extension preamplication (PEP) and probe microplate hybridization techniques. The results showed that the detection rate of SRY gene in maternal blood from women carrying male fetuses detected by probe microplate hybridization alone and probe microplate hybridization with PEP were 76.09 % (35/46) and 95.65 % (44/46) respectively, and there was a significant difference between them. The non detection rate of SRY gene in blood samples from women carrying female fetus was 100 % (19/19). It is indicated that probe microplate hybridization was an effective method in detecting trace fetal DNA from maternal plasma and the sensitivity could be substantially improved by combined use of the two techniques. Analysis of fetal DNA in maternal plasma can serve as an alternative for non invasive prenatal diagnosis.展开更多
Here, we present an optimization of colorimetric determination of hydrogen peroxide content in plants using potassium iodide. Our method is based on a one step buffer (extraction and reaction) for the determination of...Here, we present an optimization of colorimetric determination of hydrogen peroxide content in plants using potassium iodide. Our method is based on a one step buffer (extraction and reaction) for the determination of H2O2 in different plant tissues and overcomes interference of soluble antioxidant and color background. A particular attention is paid to buffer pH shown to be tissue dependent. With this inexpensive microplate method, it is possible to analyze 12 experimental samples in about 45 min all in triplicates, with blanks, controls and standard curve.展开更多
Abstract: A simple optimized microplate-based method to assay endo-1,4-β-mannosidase activity was described as an improved high-throughput screening method. A series of experimental conditions were optimized. It is ...Abstract: A simple optimized microplate-based method to assay endo-1,4-β-mannosidase activity was described as an improved high-throughput screening method. A series of experimental conditions were optimized. It is revealed that the optimum measurement procedure is as follows: adding 50μL of diluted enzyme sample and 50 μL substrate, incubating at 45 ℃ for exactly 5 min in micro-plate, mixing with 100 μL 3,5-dinitrosalicylic acid (DNS) reagent, maintaining at boiling point for 15 rain, cooling down to room temperature before determining the ABS value at 540 nm using an ELISA micro-plate reader. The reaction volume of the optimized microplate-assay is reduced to 200μL from 2 500 μL used in the standard β-mannanase macro-assay. The optimized micro-assay is significantly more sensitive in all of the 643 candidates during endo-1,4-β-mannosidase screening. Statistical analyses show that the sensitivity of the optimized micro-method is significantly greater than that of the macro-assay. The optimized method is convenient, fast, and cheap for high throughput enzyme screening.展开更多
An electrochemical method for the simultaneous detection of two different DNA sequences from PAT and FMV 35S gene sequence using CdS and PbS quantum dots (QDs) as labels was described. The QDs were readily functiona...An electrochemical method for the simultaneous detection of two different DNA sequences from PAT and FMV 35S gene sequence using CdS and PbS quantum dots (QDs) as labels was described. The QDs were readily functionalized with oligonucleotides as electrochemical DNA probes and selectively hybridized to the complementary sequences immobilized on the microplate. The QDs anchored on the hybrids were dissolved in the solution by the oxidation of HNO3 and further detected by a sensitive differential pulse anodic stripping voltammetric method (DPASV). The DPASV signals of the oxidation of Cd^2+ and Pb^2+ ions present in the solution were different and reflected the identity of corresponding ssDNA targets sequences.展开更多
基金supported by the Digitization Construction of Insect Specimen of Nature Reserve from MST(2005DKA21404)
文摘A new species of Microplitis Foerster 1862:Microplitis vitellipedis,sp.nov.(♀) is described from China,Fujian,Mt.Wuyi.The new species is similar to Microplitis changbaishana Song et Chen.but has the following differences:Microplitis vitllivipes sp.nov:T1 parallel or subparallel-sided;antennae with F12-15 loosely connected;hind coxae reddish yellow;body normal.Microplitis changbaishana Song et Chen:T1 slightly widened towards apex;antennae with F12-15 tightly connected;hind coxae yellowish beown;body stout.
基金support from the Na-tional Natural Science Foundation of China (30871640,30330410)the National Basic Research Program ofChina (2007CB109202)the Research Foundationof State Key Laboratory for Biology of Plant Diseasesand Insect Pests of China (SKL2007SR01)
文摘A gene encoding a novel G protein β subunit of β1 subclass, GβMmed was isolated from Microplitis mediator (Hymenoptera: Braconidae). The full-length sequence of GβMmed is 1 119 bp, the cDNA contains a 1 023 bp open reading frame that encodes a protein with 340 amino acids, and the predicted molecular weight of GβMmed is 37.23 kDa and isoelectric point is 5.86. By the quantitative real-time RT-PCR method, the tissue-specific expression and quantitative changes in the developmental expression profile of GβMmed were detected. It was found that GβMmed was abundantly expressed in M. mediator antennae, head (without antennae), thorax, abdomen, legs and the wings, and especially at high levels in abdomen. In antennae, expression varied through 1st day before emergence to 5-d-old adults, and had equal expression levels detected in females and males in total. In head, GβMmed expresses while initially high in females, and have another peaked in stage 4 and 1st day, in males showed a peak of GβMmed expression prior to emergence and relatively low levels after emergence. In female abdomen GβMmed expression levels have two peaks in stage 1 and the 5th d, but just have one peak in male abdomen in stage 1. In all other tissues expression was low and stable.
基金supported by the National Natural Science Foundation of China(32150410366,31972338,and 32372639)China Agriculture Research System(CARS-02-26)the National Key Research and Development Program of China(2021YFD1400700).
文摘Sex pheromones are considered to play critical roles in partner communication of most parasitic Hymenoptera.However,the identification of sex pheromone components remains limited to a few families of parasitoid wasps.In this study,we functionally characterized a candidate sex pheromone component in Microplitis mediator(Hymenoptera:Braconidae),a solitary parasitoid of Noctuidae insects.We found that the body surface extract from female wasps could significantly stimulate courtship behavior of males.Gas chromatography-electroantennographic detection(GC-EAD)analysis revealed that a candidate semiochemical from extract triggered significant electrophysiological response of antennae of males.By performing gas chromatography-mass spectrometer(GC-MS)measurement,GC-EAD active compound was identified as n-octyl acrylate,a candidate sex pheromone component in female M.mediator.In electroantennogram(EAG)tests,antennae of male wasps showed significantly higher electrophysiological responses to n-octyl acrylate than those of females.Y-tube olfactometer assays indicated that male wasps significantly chose n-octyl acrylate compared with the control.Furthermore,male wasps showed a remarkable preference for n-octyl acrylate in a simulated field condition behavioral trial;simultaneously,n-octyl acrylate standard could also trigger significant courtship behavior in males.We propose that n-octyl acrylate,as a candidate vital sex pheromone component,could be utilized to design behavioral regulators of M.mediator to implement the protection and utilization of natural enemies.
基金Acknowledgments This work was supported by National Basic Research Program of China (No. 2014CB138405), Strategic Priority Research Program of CAS (No. XDB 11030600), National Natural Science Foundation of China (No. 31472008, 31401804, 31272497), Open Research Fund Program of State Key Laboratory of Integrated Pest Management (Chinese IPM1407, 1304).
文摘Peptidoglycan recognition proteins (PGRPs) are a family of innate immune receptors that specifically recognize peptidoglycans (PGNs) on the surface of a number of pathogens. Here, we have identified and characterized six PGRPs from endoparasitoid wasp, Microplitis mediator (MmePGRPs). To understand the roles of PGRPs in parasitoid wasps, we analyzed their evolutionary relationship and orthology, expression profiles during different developmental stages, and transcriptional expression following infection with Gram-positive and -negative bacteria and a fungus. MmePGRP-S1 was significantly induced in response to pathogenic infection. This prompted us to evaluate the effects of RNA interference mediated gene specific knockdown ofMmePGRP-S1. The knockdown of MmePGRP-S1 (iMmePGRP-S1) dramatically affected wasps' survival following challenge by Micrococcus luteus, indicating the involvement of this particular PGRP in immune responses against Gram-positive bacteria. This action is likely to be mediated by the Toll pathway, but the mechanism remains to be determined. MmePGRP-S 1 does not play a significant role in anti-fungal immunity as indicated by the survival rate of iMmePGRP-S wasps. This study provides a comprehensive characterization of PGRPs in the economically important hymenopteran species M. mediator.
基金This work was supported by the National Natural Science Foundation of China(31471778,31672038,31621064 and 31772176).
文摘Sensory neuron membrane proteins(SNMPs),homologs of the human fatty acid transport protein CD36 family,are observed to play a significant role in chemoreception,especially in detecting sex pheromone in Drosophila and some lepidopteran species.In the current study,two full‐length SNMP transcripts,MmedSNMP1 and MmedSNMP2,were identified in the parasitoid Microplitis mediator(Hymenoptera:Braconidae).Quantitative real‐time polymerase chain reaction analysis showed that the expression of MmedSNMP1 was significantly higher in antennae than in other tissues of both sexes.In addition,the MmedSNMP1 transcript was increased dramatically in newly emerged adults and there were no significant differences between adults with or without mating and parasitic experiences.However,compared with MmedSNMP1,the expression of MmedSNMP2 was widely found in various tissues,significantly increased at half‐pigmented pupae stage and remained at a relatively constant level during the following developmental stages.It was found that MmedSNMP1 contained eight exons and seven introns,which was highly conserved compared with other insect species.In situ hybridization assay demonstrated that MmedSNMP1 transcript was distributed widely in antennal flagella.Among selected chemosensory genes(odorant binding protein,odorant receptor,and ionotropic receptor genes),MmedSNMP1 only partially overlapped with MmedORco in olfactory sensory neurons of antennae.Subsequent immunolocalization results further indicated that MmedSNMP1 was mainly expressed in sensilla placodea of antennae and possibly involved in perceiving plant volatiles and sex pheromones.These findings lay a foundation for further investigating the roles of SNMPs in the chemosensation of parasitoids.
基金This work was supported by the National Natural Science Foundation of China(31672038,31621064 and 31772176)the National Key Research and Development Program of China(2019YFD0300105 and 2017YFD0201900).
文摘MicroRNAs(miRNAs),a class of non-coding single-strand RNA molecules encoded by endogenous genes,are about 21–24 nucleotides long and are involved in the post-transcriptional regulation of gene expression in plants and animals.Generally,the types and quantities of miRNAs in the different tissues of an organism are diverse,and these divergences may be related to their specific functions.Here we have identified 296 known miRNAs and 46 novel miRNAs in the antennae of the parasitoid wasp Microplitis mediator by high-throughput sequencing.Thirty-three miRNAs were predicted to target olfactory-associated genes,including odorant binding proteins(OBPs),chemosensory proteins,odorant receptors(ORs),ionotropic receptors(IRs)and gustatory receptors.Among these,17 miRNAs were significantly highly expressed in the antennae,four miRNAs were highly expressed both in the antennae and head or wings,while the remaining 12 miRNAs were mainly expressed in the head,thorax,abdomen,legs and wings.Notably,miR-9a-5p and miR-2525-3p were highly expressed in male antennae,whereas miR-1000-5p and novel-miR-13 were enriched in female antennae.The 17 miRNAs highly expressed in antennae are likely to be associated with olfaction,and were predicted to target one OBP(targeted by miR-3751-3p),one IR(targeted by miR-7-5p)and 14 ORs(targeted by 15 miRNAs including miR-6-3p,miR-9a-5p,miR-9b-5p,miR-29-5p,miR-71-5p,miR-275-3p,miR-1000-5p,miR-1000-3p,miR-2525-3p,miR-6012-3p,miR-9719-3p,novel-miR-10,novel-miR-13,novel-miR-14 and novel-miR-28).These candidate olfactory-associated miRNAs are all likely to be involved in chemoreception through the regulation of chemosensory gene expression in the antennae of M.mediator.
基金supported by a grant from the National Science and Technology Council of the Republic of China(Grant Number:MOST 112-2221-E-006-048-MY2).
文摘This work develops a Hermitian C^(2) differential reproducing kernel interpolation meshless(DRKIM)method within the consistent couple stress theory(CCST)framework to study the three-dimensional(3D)microstructuredependent static flexural behavior of a functionally graded(FG)microplate subjected to mechanical loads and placed under full simple supports.In the formulation,we select the transverse stress and displacement components and their first-and second-order derivatives as primary variables.Then,we set up the differential reproducing conditions(DRCs)to obtain the shape functions of the Hermitian C^(2) differential reproducing kernel(DRK)interpolant’s derivatives without using direct differentiation.The interpolant’s shape function is combined with a primitive function that possesses Kronecker delta properties and an enrichment function that constituents DRCs.As a result,the primary variables and their first-and second-order derivatives satisfy the nodal interpolation properties.Subsequently,incorporating ourHermitianC^(2)DRKinterpolant intothe strong formof the3DCCST,we develop a DRKIM method to analyze the FG microplate’s 3D microstructure-dependent static flexural behavior.The Hermitian C^(2) DRKIM method is confirmed to be accurate and fast in its convergence rate by comparing the solutions it produces with the relevant 3D solutions available in the literature.Finally,the impact of essential factors on the transverse stresses,in-plane stresses,displacements,and couple stresses that are induced in the loaded microplate is examined.These factors include the length-to-thickness ratio,the material length-scale parameter,and the inhomogeneity index,which appear to be significant.
文摘Adult size, longevity, egg load dynamics and oviposition ofMicroplitis rufiventris Kok. which began their development in the first, second, third (preferred hosts) or fourth (non-preferred hosts) instar larvae of Spodoptera littoralis (Boisd.) were studied. The parasitoid size was largely determined by the initial host size at parasitism. Non-ovipositing females derived from older hosts lived for longer periods than those derived from younger ones. However, the ovipositing females, irrespective of their size, lived for almost the same periods. At emergence, the oviducts of adult females contain a significant amount of mature eggs available for oviposition for a few hours on eclosion day. Egg load increases during the early phase of adult life. The amount of additional mature eggs and rate of egg maturation per hour was greater for wasps derived from preferred hosts compared with those in females derived from non-preferred hosts. The pattern of egg production in M. rufiventris females depended on the availability of hosts for parasitization. Host-deprived females depleted the egg complement with aging; the longer the host deprivation, the lower the oviduct egg load. Marked reduction in both realized or potential fecundity of host-deprived females was observed following host availability. Host privation for more than 3 days induced a marked deficit fecundity pattern through the female' s life. The realized fecundity was determined by the interaction among host availability, the number of eggs that are matured over the female' s life span, oviposition rate and host size from which the female was derived. These results suggest that: (i) M. rufiventris wasp is a weak synovigenic species; (ii) the maturation of additional eggs is inhibited once the maximum oviduct egg load is reached; (iii) the egg load of the newly emerged female is significantly less than the realized fecundity; and (iv) because M. rufiventris females oviposit fewer eggs when they begin depleting their egg supply at 3 days, augmentative releases will require release immediately following emergence to ensure the highest parasitization rate in the field.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11974279, 12074311, 12004310, and 12261141662)。
文摘Tin halide perovskites recently have attracted extensive research attention due to their similar electronic and band structures but non-toxicity compared with their lead analogues. In this work, we prepare high-quality CsSnX_(3)(X=Br,I) microplates with lateral sizes of around 1–4 μm by chemical vapor deposition and investigate their low-temperature photoluminescence(PL) properties. A remarkable splitting of PL peaks of the CsSnBr_(3)microplate is observed at low temperatures. Besides the possible structural phase transition at below 70 K, the multi-peak fittings using Gauss functions and the power-dependent saturation phenomenon suggest that the PL could also be influenced by the conversion from the emission of bound excitons into free excitons. With the increase of temperature, the peak position shows a blueshift tendency for CsSnI_(3), which is governed by thermal expansion. However, the peak position of the CsSnBr3microplate exhibits a transition from redshift to blueshift at ~160 K. The full width at half maximum of CsSnX_(3)broadens with increasing temperature, and the fitting results imply that longitudinal optical phonons dominate the electron–phonon coupling and the coupling strength is much more robust in CsSnBr3than in CsSnI_(3). The PL intensity of CsSnX_(3)microplates is suppressed due to the enhanced non-radiative relaxation and exciton dissociation competing with radiative recombination. According to the Arrhenius law, the exciton binding energy of CsSnBr_(3)is ~38.4 meV, slightly smaller than that of CsSnI_(3).
文摘During the Paleozoic, the Ordos area in the western North China Plate was located at the intersecting position of microplates and controlled by their interaction. The structural framework in the Ordos area, which underwent transformations in the Ordovician, the Carboniferous and the Permian respectively, was dominated by the alternation of uplift and depression. The transformations of structural framework are utilized as the clues to investigate the microplates' interacting type and its response in the Ordos area. According to the regional structural evolution, the Ordos area is simplified into an isopachous, isotropic and elastic shell model, and under proposed various boundary conditions, three series of numerical simulations corresponding to the three structural transformations are carried out to determine the detailed tectonic constraints. Numerical simulations reveal that the structure of the uplift and depression, which is similar to the actual pattern, develops only under one special boundary condition in each of the three series, indicating that the structural framework responds to the unique tectonic background. The simulation results show that in the Early Paleozoic, the L-shaped paleouplift formed nearby the southwestern corner of the Ordos area because the intensity of the compressions in the southern and western boundaries resulting from the ocean-continent collisions was similar. In the Late Paleozoic, it evolved into continent-continent (or arc-continent) interaction in the southern and northern boundaries; in the preliminary stage of the interaction, since the interface between the North China Plate and the plates on the south and north was narrow, the relative acting force was little and the regional western boundary immobile, and the structural framework in the basin was characterized by the N-S trending slender-waist-shaped uplift; as the interface between the plates expanded gradually, the extrusive force in the southern and northern boundaries of the North China Plate increased, resulting in the paleogeographic divisions showing E-W trending, and, the western boundary of the basin was extruded westward due to the intense compression inducing the local NE trending of paleogeographic division in the central area. The simulation results further reflect that the symmetry of the uplift-depression pattern is restricted by that of the boundary conditions, suggesting that the Paleozoic structural transformations of the Ordos area under boundary constraints accord with the universal physical symmetrical principle.
文摘A new method for the determination of antithrombotic activity of egg white protein hydrolysate (EWPH) was developed using a microplate reader. Reaction was carried out at 37℃and pH 7.2 with fibrinogen concentration 0.1%. Microplate reading was conducted at 405 nm. Inhibition rate of EWPH on thrombin activity showed linearity (R2 = 0.9971), when the inhibition rate was in the range of 10-90%. The lower limit of detection (LLD, at 99.7% probability) and the biological limit of detection (BLD, at 99.7% probability) of the method were 10.643 and 40 mg/mL, respectively. The repeatability standard deviation (R.S.D.) was 1.08%. The standard deviation of the method was ±0.027 AT-U.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No. 2002CB412304) the Chinese Academy of Sciences (No. KZCX1-SW-Ⅱ-32).
文摘A microtiter plate assay (MPA) for soluble reactive phosphorus (SRP) was applied to samples in overlying water and pore water as well as in three forms of environmental soil test phosphorus (P) types: water soluble phosphorus (WSP),diluted calcium chloride extractable phosphorus (PCaCl2), and Olsen-P in the sediments of Taihu Lake, China, where potential P release in response to pH was analyzed. MPA for rapid P analysis was shown to be promising when applied on samples of natural water and sediment extracts. Concentrations of WSP and PCaCl2 in the sediments were much lower than those of Olsen-P. Olsen-P levels in the littoral sediments along the north coast of Meiliang Bay in Taihu Lake (80to 140 mg kg-1) were much higher than those in the mouth of the bay (less than 50 mg kg-1). The risk of P release in the mouth area of Meiliang Bay was lower than that in the north littoral zone with a risk of sediment P release induced by pH increases.
文摘Objective: To identify the impact of lamivudine on HBV e antigen (HBeAg) seroconversion and HBV DNA level, and the appearance of Tyr-Met-Asn-Asp (YMDD) resistants. Methods: Forty-seven hepatitis B patients were trea- ted with oral lamivudine. ALT level and HBeAg were detected in the treatment on the zero, 3rd, 6th and 9th month respectively. The levels of HBV DNA and YMDD resistants were analyzed with PCR mi- croplate hybridization-ELISA. Results: After 9 months of treatment, HBV DNA be- came negative and ALT level was normal in 74% pa- tients. Among these patients, 17% patients had HBeAg converted to negative and anti-HBe antibody positive, whereas another 15% patients showed HBeAg negative. YMDD resistants appeared in 19 % patients (9/47). One, three and five resistants were detected in the treatment on the 3rd, 6th and 9th month respectively. Conclusions: Most HBV DNA in serum became nega- tive after 9 months of treatment, and the rate of HBeAg seroconversion was 17% (HBV DNA level was lower than 100 pg/ml before treatment). YMDD resistants appeared in 19% patients.
基金Supported by Project of Sichuan Provincial Health Department(120385)Project of Sichuan Provincial Science and Technology Department(14JC0137)Project of Luzhou City Department of Science and Technology(2015LZCYDS09(2/8))
文摘[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and provide experimental basis for the development of medicinal resources of P. ramosissimus. [Methods] The ultrasonic extraction method was adopted and orthogonal design was carried out to study the effects of ethanol concentration( A),ultrasonic time( B),the solid-to-liquid ratio( C) on the extraction of flavonoids from leaves of P. ramosissimus. The Microplate Reader was used to measure the content of flavonoids in leaves of P. ramosissimus. in different extraction conditions,P. ramosissimus. and the optimal extraction conditions were used to measure the content of flavonoids from leaves of P. ramosissimus.[Results]Effects of the ultrasonic extraction method on the extraction rate of flavonoids from leaves of P. ramosissimus: extraction times >ethanol concentration > Ultrasound time > solid-liquid ratio. The screened optimal extraction process was: ethanol concentration of 65%,the solid-to-liquid ratio of 1∶ 25,ultrasonic time of 2 h and extraction times Under this condition,the extraction rate of total flavonoids in leaves of P. ramosissimus. was 2. 56%. [Conclusions] This method is simple and feasibility,reliable,and suitable for rapid measurement with large samples.
基金the Project of State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau,Chinese Academy of Sciences(A314021402-1916)the Key Project of the Ministry of Science and Technology of China(2017YFD0200200)the Innovative Engineering Project of Shaanxi Province,China(2016slkj-15)。
文摘Crop residue is a major source of soil organic matter;therefore,application of crop straw to soil contributes to the sustainable development of organic agriculture.To better understand the transformation of crop straw in orchard soils,we investigated the relationship between the characteristics of straw decomposition and functional diversity of associated microbial communities in a long-term peach orchard,China.Mesh bags,each containing 30 g of corn or bean straw,were buried at a soil depth of 20 cm in a 12-year-old peach orchard for 360 d(October 2011–October 2012).Three treatments were applied,i.e.,fresh corn straw,fresh corn straw with nitrogen fertilizer(urea,10.34 g/kg),and fresh bean straw.Changes in straw residual rate,straw water content and soil conditions were monitored after treatment.The functional diversity of straw-associated microbial communities was analyzed by the Biolog-Eco microplate assay.During the decomposition process,straw residual rates did not vary considerably from 10 d(30.4%–45.4%)to 360 d(19.0%–30.3%).Irrespective of nitrogen addition,corn straw decomposed faster than bean straw.Corn straw with nitrogen fertilizer yielded the highest average well color development(AWCD)values(1.11–1.67),followed by corn straw(1.14–1.68)and bean straw(1.18–1.62).Although the AWCD values did not differ significantly among the three treatments,substantial differences occurred across various time periods of the decomposition process(P<0.01).In terms of carbon source utilization,the dominant microbial groups fed mainly on saccharides.Hard-to-decompose substances gradually accumulated in the middle and late stages of straw decomposition.Of the six categories of carbon sources tested,the utilization rate of aromatics was the lowest with corn straw,whereas that of polymers was the lowest with bean straw.Among different treatments,straw residual rate was negatively correlated to soil available phosphorous,soil available potassium and soil temperature(P<0.05),but not to soil water content.In some cases(corn straw with or without nitrogen fertilizer),straw residual rate was negatively correlated to straw water content,amino acid utilization and carboxylic acid utilization,and positively correlated with microbial species richness and evenness(P<0.05).Microbial community associated with corn and bean straw decomposition in soil was respectively dominated by aromatic-and polymer-metabolizing groups during the middle and late stages of this process,which could reduce the stability of microbial community structure and decrease the rate of straw decomposition in the fruit tree orchard.
基金The National Basic Research Program of China(973 Program)under contract No.2012CB417305China Ocean Mineral Resources R&D Association"Twelfth Five-Year"Major Program under contract Nos DY125-11-R-01 and DY125-11-R-05+1 种基金the Natural Science Foundation of Zhejiang Province under contract No.LY12D06006the scientific research fund of the Second Institute of Oceanography under contract No.JG1203
文摘Hydrothermal plume is an important constituent of seabed hydrothermal circulation and is also one of the characteristics of active hydrothermal vents. Portable Miniature Autonomous Plume Recorders (MAPR) attached to a towed deep-sea instrument was used to search for hydrothermal plumes and hydrothermal vents. We introduced the basic principle of MAPR based on deep towing technology to detect plumes, then analyzed the factors affecting the quality of the MAPR data and presented a data correction method for MAPR, including instrument location correction, noise reduction processing, system error elimination and seawater background reduction. Finally we applied the method to analyze MAPR data obtained during the Chinese DY115-21 cruise on R/VDayang Iin the “Precious Stone Mountain” hydrothermal field on the Gala-pagos Microplate. The results provided a better understanding of the distribution of the hydrothermal activ-ity in this field, indicating the presence of a new hydrothermal vent.
基金This project was supported by a grant from ScienceFoundation of Health Ministry(No.96 .2 - 112 ) and HubeiProvincial Natural Science Foundation(No.96 J0 6 8)
文摘To investigate the feasibility of using free fetal DNA from maternal plasma as the source of fetal material in non invasive prenatal diagnosis, SRY gene of free DNA in maternal blood of 65 samples were analyzed by using primer extension preamplication (PEP) and probe microplate hybridization techniques. The results showed that the detection rate of SRY gene in maternal blood from women carrying male fetuses detected by probe microplate hybridization alone and probe microplate hybridization with PEP were 76.09 % (35/46) and 95.65 % (44/46) respectively, and there was a significant difference between them. The non detection rate of SRY gene in blood samples from women carrying female fetus was 100 % (19/19). It is indicated that probe microplate hybridization was an effective method in detecting trace fetal DNA from maternal plasma and the sensitivity could be substantially improved by combined use of the two techniques. Analysis of fetal DNA in maternal plasma can serve as an alternative for non invasive prenatal diagnosis.
文摘Here, we present an optimization of colorimetric determination of hydrogen peroxide content in plants using potassium iodide. Our method is based on a one step buffer (extraction and reaction) for the determination of H2O2 in different plant tissues and overcomes interference of soluble antioxidant and color background. A particular attention is paid to buffer pH shown to be tissue dependent. With this inexpensive microplate method, it is possible to analyze 12 experimental samples in about 45 min all in triplicates, with blanks, controls and standard curve.
基金Project(31000350)supported by the National Natural Science Foundation of China
文摘Abstract: A simple optimized microplate-based method to assay endo-1,4-β-mannosidase activity was described as an improved high-throughput screening method. A series of experimental conditions were optimized. It is revealed that the optimum measurement procedure is as follows: adding 50μL of diluted enzyme sample and 50 μL substrate, incubating at 45 ℃ for exactly 5 min in micro-plate, mixing with 100 μL 3,5-dinitrosalicylic acid (DNS) reagent, maintaining at boiling point for 15 rain, cooling down to room temperature before determining the ABS value at 540 nm using an ELISA micro-plate reader. The reaction volume of the optimized microplate-assay is reduced to 200μL from 2 500 μL used in the standard β-mannanase macro-assay. The optimized micro-assay is significantly more sensitive in all of the 643 candidates during endo-1,4-β-mannosidase screening. Statistical analyses show that the sensitivity of the optimized micro-method is significantly greater than that of the macro-assay. The optimized method is convenient, fast, and cheap for high throughput enzyme screening.
基金the National Natural Science Foundation of China(Nos.20405008,20635020).
文摘An electrochemical method for the simultaneous detection of two different DNA sequences from PAT and FMV 35S gene sequence using CdS and PbS quantum dots (QDs) as labels was described. The QDs were readily functionalized with oligonucleotides as electrochemical DNA probes and selectively hybridized to the complementary sequences immobilized on the microplate. The QDs anchored on the hybrids were dissolved in the solution by the oxidation of HNO3 and further detected by a sensitive differential pulse anodic stripping voltammetric method (DPASV). The DPASV signals of the oxidation of Cd^2+ and Pb^2+ ions present in the solution were different and reflected the identity of corresponding ssDNA targets sequences.