Biomedical subjects

Yang Mei

Publications and source records attributed to Yang Mei.

6 recordsLinked to original sources

PubMed2025

Large-scale Genome Analyses Provide Insights into Hymenoptera Evolution.

The order Hymenoptera includes a large number of species with diverse lifestyles and is known for its significant contributions to natural ecosystems. To better understand the evolution of this diverse order, we performed large-scale comparative genomics on 131 species from 13 superfamilies, covering most representative groups. We used these genomes to reveal an overall pattern of genomic change in terms of gene content and evolutionary rate throughout hymenopteran history. We identified genes that possibly contributed to the evolution of several key innovations, such as parasitoidism, wasp-waist, stinger, and secondary phytophagy. We also discovered the distinct genomic trajectories between the clade containing major parasitoid wasps (Parasitoida) and stinging species (Aculeata) since their divergence, which are involved in many aspects of genomic change, such as rapidly evolving gene families, gene gain and loss, and metabolic pathway evolution. In addition, we explored the genomic features accompanying the three independent evolution of secondary phytophagy. Our work provides insights for understanding genome evolution and the genomic basis of diversification in Hymenoptera.

Animals↗

PubMed2006

Investigations of the EPR g factors and hyperfine structure constants for two trigonal Co2+ centers in Al2O3 crystals.

The EPR g factors gparallel, gperpendicular and the hyperfine structure constants Aparallel, Aperpendicular for two trigonal Co2+ centers (i.e. Co2+(I) center at the substitutional site and Co2+(II) center at the interstitial site) in Al2O3 crystals are calculated from the second-order perturbation formulas based on the cluster approach. In these formulas, the contributions to EPR parameters from both the spin-orbit coupling parameter of central 3dn ion and that of ligand are included. The calculated results are in reasonable agreement with the observed values. Based on the calculations, the defect structures of both Co2+ centers in Al2O3 crystals are obtained and the negative sign of Aparallel for Co2+(I) center is suggested. The results are discussed.

Aluminum Oxide↗

PubMed2006

A sequential injection analysis/chemiluminescent plant tissue-based biosensor system for the determination of diamine.

In this paper, a new chemiluminescent plant tissue-based biosensor for diamine detection was presented by employing sequential injection analysis (SIA), which facilitates precise fluidic handling and lower consumption of sample and reagents. Pea-seedling tissue acted as the molecular recognition element and was packed in a mini-PTFE column and further incorporated in the SIA system. The analysis of diamines, such as putrescine and cadaverine, is based on an enzymatic conversion which takes place in the plant tissue column to produce hydrogen peroxide. The formed hydrogen peroxide was detected by a chemiluminescence reaction involving luminol and Co(2+). Under the optimal conditions, the linear calibration graphs were obtained within 0.2-80 microM (putrescine) and 0.5-100 microM (cadaverine). The detection limits of 0.03 and 0.06 microM were achieved for putrescine and cadaverine, respectively, along with the relative standard deviations of 2.14% and 3.08% (n=11) and a sampling frequency of 40 h(-1). The present biosensor has been used for the analysis of diamine in fish samples with an acceptable accuracy.

Biological Assay↗

PubMed2006

Studies of the trigonal field parameters and g factors for magnetic semiconductor NaCrS2.

The trigonal field parameters v and v' of magnetic semiconductor NaCrS2 are calculated from the superposition model, and its g factors g parallel and g perpendicular are calculated from the high-order perturbation formulas of 3d3 ions in trigonal symmetry obtained by the one and two spin-orbit coupling parameter models. These calculations are based on the structural data of NaCrS2 crystal. The calculated results suggest that the superposition model is effective to the analyses of the low-symmetry field parameters of 3dn ions in crystals and that the two spin-orbit coupling parameter model (where the contributions from both the spin-orbit coupling parameter of 3dn ion and that of ligand are considered) is preferable to the one spin-orbit coupling parameter model (in which the contribution from only the spin-orbit coupling parameter of 3dn ion is considered) in the explanations of g factors in the cases that ligands have large spin-orbit coupling parameter in 3dn clusters.

Chromium Compounds↗

PubMed2005

Effect of PD I administration on dopamine receptors mRNAs expression in the lesioned striatum of PD rat model.

To study the effect of PD I administration on dopamine receptors (DR1, DR2) mRNAs expression in the lesioned striatum of the PD rat model and confirm if PD I has the effect of dopamine receptor agonist. The PD rats with unilateral 6-hydroxydopamine lesioned were administrated with PD I, L-dopa methyl/benserazide, L-dopa methyl /benserazide/ PD I, normal saline respectively for 4 weeks and their behavioral changes were observed. Then the rats were sacrificed and RT-PCR technique was used to detect changes of dopamine receptors (DR1, DR2) mRNAs expression in the ipsilateral striatum 1 day after the last treatment. The results showed that treatment with PD I plus L-dopa resulted in a stable contralateral rotation behavior; treatment with L-dopa resulted in a progressively increased contralateral rotation behavior. Rotation behavior induced by anhydromorphine decreased with PD I or PD I plus L-dopa treatment. Treatment With L-dopa or PD I plus L-dopa, up-regulation of DR1 mRNA and down-regulation of DR2 mRNA were observed in the ipsilateral striatum which were more obvious than that treated with PD I or vehicle (P < 0.05). It was concluded that long-term treatment with PD I could alleviate the behavior of PD rats. PD I had no apparent effect on the dopamine receptors (DR1, DR2) mRNAs expression in the ipsilateral striatum and the PD I has no agonist effect on dopamine receptors.

Animals↗

PubMedDate not supplied

A novel flow-injection chemiluminescence system for the determination of guanine.

A novel flow-injection chemiluminescence (CL) method for the determination of guanine was developed. The procedure is based on the CL reaction of guanine with hydrogen peroxide in borax buffer (pH 8.5) with Co2+ as a catalyst. The calibration graph is linear within the range of 3 x 10(-7)-9 x 10(-5) g/mL. A detection limit of 1 x 10(-7) g/mL, along with a relative standard deviation of 2.23% (3 x 10(-7) g/mL guanine, n = 11), were obtained. The present procedure was applied to the measurement of guanine in urine with recoveries of 97.5-107.5%. A possible CL mechanism of the reaction system is proposed.

Buffers↗