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1.
Identification of Rhodiola species by using RP-HPLC   总被引：2，自引：0，他引：2  
INTRODUCTION The roots of Rhodiola species, one of the im-portant traditional Chinese herbal medicines, have anti-viral (Sun et al., 1993), anti-tumor (Wang et al., 1992), anti-ageing (Yi et al., 1992), anti-oxygen de-ficiency, anti-radiation (Luo et al., 1996) effects and other pharmacological properties (Xu et al., 2000). Ten Rhodiola species distribute in the Tianshan Mountains areas of China. Biologically active com-pounds content in the roots has large variation and the value of…  相似文献   

2.
Studies were conducted on specific core collections constructed on the basis of different traits and sample size by the method of stepwise cluster with three sampling strategies based on genotypic values of cotton. A total 21 traits (11 agronomy traits, 5 fiber traits and 5 seed traits) were used to construct main core collections. Specific core collections, as representative of the initial collection, were constructed by agronomy, fiber or seed trait, respectively. As compared with the main core collection, specific core collections tended to have similar property for maintaining genetic diversity of agronomy, seed or fiber traits. Core collections developed by about sample size of 17% (P 2=0.17) and 24% with three sampling strategies could be quite representative of the initial collection. Project(No 39470377) supported by NSFC  相似文献   

3.
Midkine is a heparin-binding growth factor, which plays important roles in the regulation of cell growth and differentiation. The non-tagged recombinant human midkine (rhMK) is therefore required to facilitate its functional studies of this important growth factor. In the present work, rhMK was expressed in Escherichia coli (E. coli) BL21 (DE3). The expression of midkine was efficiently induced by isopropyl-β-D-thiogalactopyranoside (IPTG). After sonication, midkine was recovered in an insoluble form, and was dissolved in guanidine hydrochloride buffer. Renaturation of the denatured protein was carried out in the defined protein refolding buffer, and the refolded protein was purified using S-Sepharose ion-exchange chromatography. The final preparation of the rhMK was greater than 98% pure as measured by sodium dodecylsulfate-polyacrylamid gel electrophoresis (SDS-PAGE) and reverse phase high performance liquid chromatography (RP-HPLC). The purified rhMK enhanced the proliferation of NIH3T3 cells. Project supported in part by the Hi-Tech Research and Development Program (863) of China (No. 2007AA02Z149) and the Science and Technology Commission of Shanghai Municipality (No. 075407071), China  相似文献   

4.
Seed vigor is an important characteristic of seed quality, and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment. In the present study, the quantitative trait loci (QTLs) of three traits for rice seed vigor during the germination stage, including germination rate, final germination percentage, and germination index, were investigated using one recombinant inbred line (RIL) population derived from a cross between japonica Daguandao and indica IR28, and using the multiple interval mapping (MIM) approach. The results show that indica rice presented stronger seed vigor during the germination stage than japonica rice. A total of ten QTLs, and at least five novel alleles, were detected to control rice seed vigor, and the amount of variation (R 2) explained by an individual QTL ranged from 7.5% to 68.5%, with three major QTLs with R 2>20%. Most of the QTLs detected here are likely to coincide with QTLs for seed weight, seed size, or seed dormancy, suggesting that the rice seed vigor might be correlated with seed weight, seed size, and seed dormancy. At least five QTLs are novel alleles with no previous reports of seed vigor genes in rice, and those major or minor QTLs could be used to significantly improve the seed vigor by marker-assisted selection (MAS) in rice.  相似文献   

5.
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6.
To optimize the hydrolysis conditions to prepare hydrolysates of jellyfish umbrella collagen with the highest hydroxyl radical scavenging activity, collagen extracted from jellyfish umbrella was hydrolyzed with trypsin, and response surface methodology (RSM) was applied. The optimum conditions obtained from experiments were pH 7.75, temperature (T) 48.77 °C, and enzyme-to-substrate ratio ([E]/[S]) 3.50%. The analysis of variance in RSM showed that pH and [E]/[S] were important factors that significantly affected the process (P<0.05 and P<0.01, respectively). The hydrolysates of jellyfish umbrella collagen were fractionated by high performance liquid chromatography (HPLC), and three fractions (HF-1>3000 Da, 1000 Da<HF-2<3000 Da, and HF-3<1000 Da) were collected. The HF-2 fraction had the highest hydroxyl radical scavenging activity with the highest yield compared with the other two fractions. Furthermore, HF-2 also showed the strongest Cu2+-chelating ability and the best tyrosinase-inhibitory activity. Project (No. 2008BAD94B07) supported by the Hi-Tech Research and Development Program (863) of China  相似文献   

7.
Abstract

The information on farmers' indigenous social networks in local seed systems is based on a case study undertaken in the central rift valley of Ethiopia. Farmers' indigenous social networks (social relation, locally developed seed exchange methods and local institutions) are presented as leverage mechanisms for the survival of local seed systems. A farmer decision to acquire seeds is discussed as an act of making a choice between whether to obtain a new germplasm/maintain old ones (genetic diversity management) or a search for renewable physical input (seed) or to take advantage of each merit in specific situations. This clearly underscores the need to value the individual merit of a seed before putting in place any type of variety selection, seed multiplication or extension programs. Analysis of the case study leads to the conclusion that the government imposed extension program should focus on institutional transformation of farmers' indigenous social networks in order to validate the complementary role of local seed systems in the development of a national seed industry.  相似文献   

8.
The genetic effects on individual differences in reading development were examined using genome‐wide complex trait analysis (GCTA) in a twin sample. In unrelated individuals (one twin per pair, n = 2,942), the GCTA‐based heritability of reading fluency was ~20%–29% at ages 7 and 12. GCTA bivariate results showed that the phenotypic stability of reading fluency from 7 to 12 years (r = 0.69) is largely driven by genetic stability (genetic r = 0.69). Genetic effects on print exposure at age 12 were moderate (~26%) and correlated with those influencing reading fluency at 12 (genetic r = 0.89), indicative of a gene–environment correlation. These findings were largely consistent with quantitative genetic twin analyses that used both twins in each pair (n = 1,066–1,409).  相似文献   

9.
Using SnxTi1-xO2 as carriers, CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 were examined using a microreactor-gas chromatography (GC) NO CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.  相似文献   

10.
Selenocosmia huwena and Selenocosmia hainana are two tarantula species found in southern China. Their venoms contain abundant peptide toxins. Two new neurotoxic peptides, huwentoxin-III (HWTX-III) and hainantoxin-VI (HNTX-VI), were obtained from the venom using ion-exchange chromatography and reverse-phase high performance liquid chromatography (RP-HPLC). The mechanism of action of HWTX-III and HNTX-VI on insect neuronal voltage-gated sodium channels (VGSCs) was studied via whole-cell patch clamp techniques. In a fashion similar to δ-atracotoxins, HNTX-VI can induce a slowdown of current inactivation of the VGSC and reduction in the peak of Na+ current in cockroach dorsal unpaired median (DUM) neurons. Meanwhile, 10 μmol/L HNTX-IV caused a positive shift of steady-state inactivation of sodium channel. HWTX-III inhibited VGSCs on DUM neurons (concentration of toxin at half-maximal inhibition (IC50)≈1.106 μmol/L) in a way much similar to tetrodotoxin (TTX). HWTX-III had no effect on the kinetics of activation and inactivation. The shift in the steady-state inactivation curve was distinct from other depressant spider toxins. The diverse effect and the mechanism of action of the two insect toxins illustrate the diverse biological activities of spider toxins and provide a fresh theoretical foundation to design and develop novel insecticides.  相似文献   

11.
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12.
Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants (Caralluma acutangula, Rhazya stricta, and Moringa peregrina) and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp. (6 isolates), Alternaria sp. (2), Bipolaris sp. (1), and Cladosporium sp. (1) based on 18S rDNA sequencing and phylogenetic analysis. The culture filtrates (CFs; 25%, 50%, and 100% concentrations) from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF (100%) of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry (GC/MS) analysis showed the highest indole acetic acid content ((54.31±0.21) μmol/L) in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses.  相似文献   

13.

Objective

To investigate the antibacterial mechanism of high-mobility group nucleosomal-binding domain 2 (HMGN2) on Escherichia coli K12, focusing on the antibacterial and antibiofilm formation effects. Its chemotactic activity on human neutrophils was also investigated.

Methods

Human tissue-derived HMGN2 (tHMGN2) was extracted from fresh uterus fiber cystadenoma and purified by HP1100 reversed-phase high-performance liquid chromatography (RP-HPLC). Recombinant human HMGN2 (rHMGN2) was generated in E. coli DE3 carrying PET-32ac(+)- HMGN2. Antibacterial activity of HMGN2 was determined using an agarose diffusion assay and minimum inhibitory concentration (MIC) of HMGN2 was determined by the microdilution broth method. Bacterial membrane permeability assay and DNA binding assay were performed. The antibiofilm effect of HMGN2 was investigated using a crystal violet assay and electron microscopy scanning. The activating effect and chemotactic activity of HMGN2 on neutrophils were determined using a nitroblue tetrazolium (NBT) reduction assay and Transwell chamber cell migration assay, respectively.

Results

HMGN2 showed a relatively high potency against Gram-negative bacteria E. coli and the MIC of HMGN2 was 16.25 μg/ml. Elevated bacterial membrane permeability was observed in HMGN2-treated E. coli K12. HMGN2 could also bind the bacterial plasmid and genomic DNA in a dose-dependent manner. The antibiofilm effect of HMGN2 on E. coli K12 was confirmed by crystal violet staining and scanning electron microscopy. However, the activating effects and chemotactic effects of HMGN2 on human neutrophils were not observed.

Conclusions

As an antimicrobial peptide (AMP), HMGN2 possessed a good capacity for antibacterial and antibiofilm activities on E. coli K12. This capacity might be associated with disruption of the bacterial membrane and combination of DNA, which might affect the growth and viability of E. coli.
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14.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｐｏｔｅｎｔｉａｌｕｓｅｒｏｆｃｏｒｅｃｏｌｌｅｃｔｉｏｎｆａｌｌｓｉｎｔｏｔｈｒｅｅｍａｉｎｇｒｏｕｐｓ:ｐｌａｎｔｂｒｅｅｄｅｒｓｗｈｏｗｉｓｈｔｏｆｉｎｄａｎｄｕｔｉｌｉｚｅｇｅｒｍｐｌａｓｍ ;ｇｅｒｍｐｌａｓｍｓｐｅｃｉａｌ ｉｓｔｓｗｈｏｗｉｓｈｔｏｓｔｕｄｙｇｅｒｍｐｌａｓｍｏｒｇｅｎｅｔｉｃｖａｒｉ ａｔｉｏｎ ;ｃｕｒａｔｏｒｓｗｈｏｒｅｑｕｉｒｅａｓｓｉｓｔａｎｃｅｗｉｔｈｇｅｒｍ ｐｌａｓｍｍａｎａｇｅｍｅｎｔ (Ｍａｃｋａｙ ,1 995) .Ｇｅｒｍ ｐｌａｓ…  相似文献   

15.
Xu  Lei  Wu  Zhifang  Wang  Yuan  Wang  Sa  Shu  Chang  Duan  Zhuhui  Deng  Shuli 《Journal of Zhejiang University. Science. B》2021,22(4):285-294
Objectives: The study aimed at identifying salivary microbiota in caries-free Chinese preschool children using highthroughput sequencing. Methods: Saliva samples were obtained from 35 caries-free preschool children(18 boys and 17 girls)with primary dentition, and 16 S ribosomal DNA(r DNA) V3–V4 hypervariable regions of the microorganisms were analyzed using Illumina MiSeq. Results: At 97% similarity level, all of these reads were clustered into 334 operational taxonomic units(OTUs). Among these, five phyla(Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Candidate division TM7) and13 genera(Streptococcus, Rothia, Granulicatella, Prevotella, Enterobacter, Veillonella, Neisseria, Staphylococcus, Janthinobacterium, Pseudomonas, Brevundimonas, Devosia, and Gemella) were the most dominant, constituting 99.4% and 89.9% of the salivary microbiota, respectively. The core salivary microbiome comprised nine genera(Actinomyces, Capnocytophaga, Gemella,Granulicatella, Lachnoanaerobaculum, Neisseria, Porphyromonas, Rothia, and Streptococcus). Analysis of microbial diversity and community structure revealed a similar pattern between male and female subjects. The difference in microbial community composition between them was mainly attributed to Neisseria(P=0.023). Furthermore, functional prediction revealed that the most abundant genes were related to amino acid transport and metabolism. Conclusions: Our results revealed the diversity and composition of salivary microbiota in caries-free preschool children, with little difference between male and female subjects.Identity of the core microbiome, coupled with prediction of gene function, deepens our understanding of oral microbiota in cariesfree populations and provides basic information for associating salivary microecology and oral health.  相似文献   

16.
This paper presents the findings of original research which applied the Early Childhood Environmental Rating Scale Extension (ECERS/E) four Curricular Subscales in 26 pre-schools throughout Ireland to measure and assess the provision of literacy, maths, science and environment, and diversity as follows: inadequate, minimal, good or excellent. The rating instrument was chosen as it relates closely to the Relational Pedagogical (RP) approach in the Irish curriculum Aistear; the Early Childhood Curriculum Framework. The approach uses four interconnected themes well-being, identity and belonging, communicating and exploring and thinking. The results are analysed using quantitative ECERS/E findings and offer evidence-based empirical results on pre-school quality using international standards of best practice. The study reveals a minimal standard in the provision of literacy and maths. Provision in science and environment and diversity are inadequate. The findings have implications concerning the capacity of pre-school services to implement quality and curriculum frameworks Síolta and Aistear and question the appropriateness of the current pre-school inspection systems in improving standards.  相似文献   

17.
Utilization of a two-line breeding system via photoperiod-thermo sensitive male sterility has a great potential for hybrid production in wheat (Triticum aestivum L.). 337S is a novel wheat male sterile line sensitive to both short daylength/low temperature and long daylength/high temperature. Five F2 populations derived from the crosses between 337S and five common wheat varieties were developed for genetic analysis. All F1’s were highly fertile while segregation occurred in the F2 populations with a ratio of 3 fertile:1 sterile under short daylength/low temperature. It is shown that male sterility in 337S was controlled by a single recessive gene, temporarily designated as wptms3. Bulked segregant analysis (BSA) coupled with simple sequence repeat (SSR) markers was applied to map the sterile gene using one mapping population. The wptms3 gene was mapped to chromosome arm 1BS and flanked by Xgwm413 and Xgwm182 at a genetic distance of 3.2 and 23.5 cM, respectively. The accuracy and efficiency of marker-assisted selection were evaluated and proved essential for identifying homozygous recessive male sterile genotypes of the wptms3 gene in F2 generation.  相似文献   

18.
Maintaining genetic diversity is a major issue in conservation biology. In this study, we demonstrate the differences of genetic diversity levels between wild and captive individuals of Elliot‘s Pheasant Syrmaticus ellioti. Wild individuals showed a higher genetic diversity level than that of the captive individuals. Nucleotide diversity and haplotype diversity of wild individuals were 0.00628 and 0.993, while those of captive individuals were 0.00150 and 0.584 respectively. Only 3 haplotypes of mtDNA control region sequence were identified among 36 captive individuals, while 16 unique haplotypes were identified among the 17 wild individuals in this study. One captive haplotype was shared by a wild individual from Anhui Province. It is concluded that a low number of founders was the likely reason for the lower level genetic diversity of the captive group. Careful genetic management is suggested for captive populations, particularly of such an endangered species, to maintain genetic variability levels.  相似文献   

19.
The changes of kernel nutritive components and seed vigor in F1 seeds of sh 2 sweet corn during seed development stage were investigated and the relationships between them were analyzed by time series regression (TSR) analysis. The results show that total soluble sugar and reducing sugar contents gradually declined, while starch and soluble protein contents increased throughout the seed development stages. Germination percentage, energy of germination, germination index and vigor index gradually increased along with seed development and reached the highest levels at 38 d after pollination (DAP). The TSR showed that, during 14 to 42 DAP, total soluble sugar content was independent of the vigor parameters determined in present experiment, while the reducing sugar content had a significant effect on seed vigor. TSR equations between seed reducing sugar and seed vigor were also developed. There were negative correlations between the seed reducing sugar content and the germination percentage, energy of germination, germination index and vigor index, respectively. It is suggested that the seed germination, energy of germination, germination index and vigor index could be predicted by the content of reducing sugar in sweet corn seeds during seed development stages. Project supported by the National Natural Science Foundation of China (No. 30370911) and Education Department of Zhejiang Province, China (No. 20070147)  相似文献   

20.
Objective: To study the stereoselective glucuronidation of carvedilol (CARV) by three Chinese liver microsomes. Methods: The metabolites of CARV were identified by a hydrolysis reaction with β-glucuronidase and HPLC-MS/MS. The enzyme kinetics for CARV enantiomers glucuronidation was determined by a reversed phase-high pressure liquid chromatogra-phy (RP-HPLC) assay using (S)-propafenone as internal standard after precolumn derivatization with 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosylisothiocyanate. Results: Two CARV glucuronides were found in three Chinese liver microsomes incubated with CARV. The non-linear regression analysis showed that the values of Km and Vmax for (S)-CARV and (R)-CARV enantiomers were (118±44) μmol/L, (2 500±833) pmol/(min·mg protein) and (24±7) μmol/L, (953±399) pmol/(min·mg protein), respectively. Conclusion: These results suggested that there was a significant (P<0.05) stereoselective glucuronidation of CARV enantiomers in three Chinese liver microsomes, which might partly explain the enantioselective pharmacokinetics of CARV.  相似文献   

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