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1.
World J Gastroenterol ; 29(24): 3871-3882, 2023 Jun 28.
Article in English | MEDLINE | ID: mdl-37426321

ABSTRACT

BACKGROUND: Stereotactic body radiotherapy (SBRT) and programmed cell death 1 inhibitors have shown potential in treating hepatocellular carcinoma (HCC) in retrospective studies. AIM: To evaluate the efficacy of combining SBRT with sintilimab for patients with recurrent or oligometastatic HCC. METHODS: This trial involved patients with recurrent or oligometastatic HCC intravenously treated with SBRT plus sintilimab every 3 wk for 12 mo or until disease progression. The primary endpoint was progression-free survival (PFS). RESULTS: Twenty-five patients were enrolled from August 14, 2019, to August 23, 2021. The median treatment duration was 10.2 (range, 0.7-14.6) months. SBRT was delivered at a median dose of 54 (range, 48-60) Gy in 6 (range, 6-10) fractions. The median follow-up time was 21.9 (range, 10.3-39.7) mo, and 32 targeted lesions among 25 patients were evaluated for treatment response according to the Response Evaluation Criteria in Solid Tumors version 1.1. The median PFS was 19.7 mo [95% confidence interval (CI): 16.9-NA], with PFS rates of 68% (95%CI: 52-89) and 45.3% (95%CI: 28-73.4) at 12 and 24 mo, respectively. The median overall survival (OS) was not reached, with OS rates of 91.5% (95%CI: 80.8-100.0) and 83.2% (95%CI: 66.5-100.0) at 12 and 24 mo, respectively. The 1- and 2-year local control rate were 100% and 90.9% (95%CI: 75.4%-100.0%), respectively. The confirmed objective response rate and disease control rate was 96%, and 96%, respectively. Most adverse events were graded as 1 or 2, and grade 3 adverse events were observed in three patients. CONCLUSION: SBRT plus sintilimab is an effective, well-tolerated treatment regimen for patients with recurrent or oligometastatic HCC.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Radiosurgery , Humans , Radiosurgery/adverse effects , Retrospective Studies
2.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(4): 364-370, 2020 Aug 01.
Article in Chinese | MEDLINE | ID: mdl-32865352

ABSTRACT

OBJECTIVE: To explore the association between two single nucleotide polymorphisms (SNPs), namely, rs4691383 and rs7667857, in the platelet-derived growth factor-C (PDGF-C) gene, the genotypes, environmental exposure factors, and nonsyndromic cleft lip with or without cleft palate (NSCL/P) in Western Chinese population. METHODS: A total of 268 case-parent trios were selected, and two SNPs (rs4691383 andrs7667857) were genotyped by using polymerase chain reaction and restriction enzyme fragment length polymorphic method and direct sequencing method. Hardy-Weinberg equilibrium, linkage disequilibrium test, transmission disequilibrium test, and haplotype analysis were conducted to analyze the data. Meanwhile, the questionnaires on the epidemiology of cleft lip and palate filled by the included samples were collected, and the interaction between the genotypes of the two SNPs and environmental exposure factors was assessed by conditional logistic regression. RESULTS: The A allele at rs4691383 and the G allele at rs7667857 of PDGF-C gene were over-transmitted for NSCL/P (P<0.05). No interaction effect was observed between the three environmental exposure factors (history of smoking/passive smoking, folic acid supplementation, and long-term inhalation of harmful environmental gases) and the PDGF-C genotypes among NSCL/P (P>0.05). CONCLUSIONS: The rs4691383 and rs7667857 at PDGF-C gene are closely related to the occurrence of NSCL/P in Western Chinese population. However, the interaction between environmental exposure factors and PDGF-C genotypes is not obvious in the occurrence of NSCL/P.


Subject(s)
Cleft Lip , Cleft Palate , Case-Control Studies , Genetic Predisposition to Disease , Genotype , Humans , Lymphokines , Platelet-Derived Growth Factor , Polymorphism, Single Nucleotide
3.
Technol Cancer Res Treat ; 19: 1533033820937002, 2020.
Article in English | MEDLINE | ID: mdl-32613904

ABSTRACT

PURPOSE: To assess the efficacy and safety of stereotactic body radiation therapy using an abdominal compression technique and modified fractionation regimen (5-10 fractions) in patients with small-sized hepatocellular carcinoma. METHODS: A total of 101 patients with small-sized hepatocellular carcinoma treated with stereotactic body radiation therapy using an abdominal compression technique and modified fractionation regimen were registered between June 2011 and June 2019 in our hospital. A total dose of 48 to 60 Gy was applied over 5 to 14 consecutive days. Liver motion was controlled by abdominal compression, and a helical intensity-modified radiation therapy-based stereotactic body radiation therapy administrated in tomotherapy platform. RESULTS: The median follow-up period was 23.2 months (range: 4.1-99.2 months). Complete response and partial response were observed in 63 (62.4%) patients and in 24 (23.8%) patients, respectively. At the time of our analysis, the 1-, 3-, and 5-year local control rates after stereotactic body radiation therapy were 96.1%, 89.0%, and 89.0%, respectively. However, logistic regression analysis revealed no correlation between the biologically effective dose and 3-year local control rates. The 1-, 3-, and 5-year overall survival rates were 96.9%, 69.0%, and 64.3%, respectively. For patients who were treatment-naive, the 1-, 3-, and 5-year overall survival were 96.3%, 82.0%, and 82.0%, respectively. No patients experienced classic radiation-induced liver disease or nonclassic radiation-induced liver disease after stereotactic body radiation therapy completion. CONCLUSIONS: When using an abdominal compression technique and modified fractionation regimen (5-10 fractions) based on helical intensity-modified radiation therapy, stereotactic body radiation therapy led to a lower toxicity and comparative rate of local control and overall survival for patients who with small-sized hepatocellular carcinoma.


Subject(s)
Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/radiotherapy , Dose Fractionation, Radiation , Liver Neoplasms/pathology , Liver Neoplasms/radiotherapy , Radiosurgery/methods , Radiotherapy, Intensity-Modulated/methods , Adult , Aged , Aged, 80 and over , Carcinoma, Hepatocellular/mortality , Disease Management , Female , Follow-Up Studies , Humans , Liver Neoplasms/mortality , Male , Middle Aged , Radiosurgery/adverse effects , Radiotherapy, Intensity-Modulated/adverse effects , Treatment Outcome , Tumor Burden
4.
Int J Mol Sci ; 21(2)2020 Jan 10.
Article in English | MEDLINE | ID: mdl-31936712

ABSTRACT

SBP-box (Squamosa-promoter binding protein) genes are a type of plant-specific transcription factor and play important roles in plant growth, signal transduction, and stress response. However, little is known about the role of pepper SBP-box transcription factor genes in response to abiotic stress. Here, one of the pepper SBP-box gene, CaSBP12, was selected and isolated from pepper genome database in our previous study. The CaSBP12 gene was induced under salt stress. Silencing the CaSBP12 gene enhanced pepper plant tolerance to salt stress. The accumulation of reactive oxygen species (ROS) of the detached leaves of CaSBP12-silenced plants was significantly lower than that of control plants. Besides, the Na+, malondialdehyde content, and conductivity were significantly increased in control plants than that in the CaSBP12-silenced plants. In addition, the CaSBP12 over-expressed Nicotiana benthamiana plants were more susceptible to salt stress with higher damage severity index percentage and accumulation of ROS as compared to the wild-type. These results indicated that CaSBP12 negatively regulates salt stress tolerance in pepper may relate to ROS signaling cascades.


Subject(s)
Capsicum/metabolism , Salt Stress/physiology , Salt Tolerance/physiology , Selenium-Binding Proteins/metabolism , Transcription Factors/metabolism , Capsicum/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Plant , Plant Leaves/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified/genetics , Reactive Oxygen Species/metabolism , Selenium-Binding Proteins/genetics , Stress, Physiological/physiology , Nicotiana/genetics , Nicotiana/metabolism , Transcription Factors/genetics
5.
Food Nutr Res ; 642020.
Article in English | MEDLINE | ID: mdl-33447178

ABSTRACT

BACKGROUND: Carotenoids, the secondary metabolites terpenoids, are the largest factors that form the fruit color. Similar to flavonoids, they are not only safe and natural colorants of fruits but also play a role as stress response biomolecules. METHODS: To study the contribution of the key genes in carotenoids biosynthesis, fruit-color formation, and in response to cold stress, we characterized the key regulatory factor CaATHB-12 from the HD-ZIP I sub-gene family members in pepper. RESULTS: Cold stress enhanced carotenoid accumulation as compared with the normal condition. CaATHB-12 silencing through virus-induced gene silencing changed the fruit color by regulating the carotenoid contents. CaATHB-12 silencing increased the antioxidant enzyme activities in the fruits of pepper, exposed to cold stress, whereas CaATHB-12 overexpression decreased the activities of antioxidant enzymes in the transgenic Arabidopsis lines, exposed to cold stress, suggesting that CaATHB-12 is involved in the regulation of cold stress in the pepper fruits. CONCLUSION: Our research will provide insights into the formation of fruit color in pepper and contribution of CaATHB-12 in response to cold stress. Further study should be focused on the interaction between CaATHB-12 and its target gene.

6.
Front Oncol ; 9: 896, 2019.
Article in English | MEDLINE | ID: mdl-31552194

ABSTRACT

Background and Objective: Radiation-induced lymphopenia has a tangible impact on overall survival (OS) in multiple solid tumors. We investigated the association between circulating lymphocyte populations (CLPs) before and after stereotactic body radiation therapy (SBRT) and OS in patients with hepatocellular carcinoma (HCC). Materials and Methods: Seventy-eight HCC patients treated with SBRT between January 2013 and June 2017 were retrospectively analyzed. Baseline and post-treatment total peripheral lymphocyte counts (TPLCs) and values of different CLPs were obtained and analyzed for clinical outcomes. Univariate and multivariate Cox regression analyses were used to explore the independent prognostic factors for patient survival. Results: The one-, two- and three-year OS rates were 94.8, 75.9, and 63.3%, respectively. The mean TPLCs before and 10 days after SBRT were 1.4 × 109/L and 0.7 × 109/L, respectively. The TPLC recovered to its baseline value 1 year after SBRT. Multivariate analysis results revealed that variables, including tumor necrosis factor-alpha (TNF-α) level <5.5 ng/mL and post-treatment TPLC <0.45 × 109/L were independent factors for inferior OS. Further analysis showed that the values of CLPs, including CD3+, CD4+, CD8+, CD19+, and CD16+56+ cells dropped profoundly 10 days after SBRT, among which CD19+ B cell count was mostly depleted and gradually recovered after 2 months. Univariate analysis showed that both baseline and post-treatment TPLC and CLP (except post-treatment B cell) counts were significantly associated with patient OS (p < 0.05 for each). Further stratified analysis performed according to OS at 2 years demonstrated that the CD16+CD56+ NK cell counts remained significantly elevated in patients with better survival (OS > 2 years) compared to those in short-term survivors at 10 days, 1 month, and 2 months after SBRT (p < 0.05 for each). In addition, there were significant differences in TPLC and CD8+ T cell counts in patients with long-term and short-term OS at 2 months after SBRT (p < 0.05). Conclusions: Peripheral lymphopenia after SBRT might be an independent prognostic factor for poorer outcome in HCC patients. Post-treatment lymphocyte subsets, including CD8+ T cell and NK cell counts were also associated with 2-year OS rates.

7.
Insect Biochem Mol Biol ; 85: 11-20, 2017 06.
Article in English | MEDLINE | ID: mdl-28412513

ABSTRACT

Wolbachia are endosymbionts that infect many species of arthropods and nematodes. Wolbachia-induced cytoplasmic incompatibility (CI) is the most common phenotype in affected hosts, involving embryonic lethality in crosses between Wolbachia-infected males and uninfected females. The molecular mechanisms underlying this phenomenon are currently unclear. Here we examine the molecular correlates of the Wolbachia infection in Laodelphax striatellus (Fallén), an important rice pest, where embryonic lethality is strong and almost complete. We compared the gene expression of 4-day-old Wolbachia-infected and uninfected L. striatellus testes to identify candidate genes for paternal-effect embryonic lethality induction. Based on microarray analysis, iLvE was the most down-regulated gene; this gene mediates branched-chain amino acid (BCAA) biosynthesis and participates in many processes related to reproductive performance. After knocking down iLvE by RNAi in uninfected male L. striatellus, male fertility was reduced, leading to a decrease in embryo hatching rates, but fertility was rescued in crosses between these males and Wolbachia-infected females. Removal of BCAA in chemically-defined diets of uninfected males also led to a loss of male fertility. Low amino acid nutrition may enhance exposure time of sperm to Wolbachia in the testes to affect adult reproduction in L. striatellus by reducing the number of sperm transferred per mating by males. These results indicate that Wolbachia may decrease male fertility in L. striatellus by acting on iLvE, a key factor of BCAA biosynthesis, and delaying sperm maturation.


Subject(s)
Amino Acids/biosynthesis , Hemiptera/microbiology , Host-Pathogen Interactions , Wolbachia/physiology , Animals , Copulation , Female , Fertility , Hemiptera/metabolism , Insect Proteins/metabolism , Male , Oligonucleotide Array Sequence Analysis , Testis/metabolism , Transcriptome
8.
Arch Oral Biol ; 76: 14-19, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28068523

ABSTRACT

OBJECTIVE: Non-syndromic orofacial cleftings (NSOCs) are considered as complex trait, which results from genetic and/or environmental modifiers. Current findings could only explain small portion of the NSOCs. SOX9 gene plays an important role during craniofacial development in animal models and the Pierre Robin sequence (PRS). However, its role in non-syndromic clefts remains unknown. DESIGN: In this study, we selected eight SNPs in and around SOX9 gene to make maximum coverage, and genotyped them by using RFLP-PCR and ligase detection reaction (LDR) methods to test its associations among 151 NSOCs (53 NSCLP, 52 NSCLO and 46 NSCPO) from Western Han Chinese population. RESULTS: Allelic TDT results showed that G allele at rs12941170 of SOX9 was under-transmitted among NSOCs (p=0.00014, OR=0.55 and 95%CI: 0.40-0.75), which could indicate that the G allele is protective against NSOCs; parent-of-origin effect analysis showed that G allele at rs12941170 was maternally under-transmitted (p=0.002), while there was no statistically difference between the maternal and paternal transmission of it. To test if the adjacent SNPs travel together from parents to the affected individual, we carried out the sliding window haplotype analysis, it is interesting to find that the haplotypes carrying the G allele at rs12941170 also was under-transmitted for NSOCs, NSCL/P, NSCLP and NSCPO (lowest p=0.00033). CONCLUSIONS: This study suggested that G allele at rs12941170 was protective, which could decrease the risk for NSOCs from Western Han Chinese population, and it will provide new reference for future research and genetic counseling in NSOCs.


Subject(s)
Cleft Lip/genetics , Cleft Palate/genetics , Polymorphism, Single Nucleotide , SOX9 Transcription Factor/genetics , Alleles , Asian People/genetics , China , Cleft Lip/ethnology , Cleft Palate/ethnology , Female , Genetic Predisposition to Disease , Genotype , Haplotypes , Humans , Male , Phenotype , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length
9.
J Oral Pathol Med ; 44(10): 864-9, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25640282

ABSTRACT

BACKGROUND: Non-syndromic orofacial clefts (NSOCs) are complex disease involving genetic triggers, environmental factors, and their interplay. Recent studies demonstrated that EYA1, a member of eye absent gene family, might contribute to NSOCs. METHODS: We investigated three single nucleotide polymorphisms (SNPs) and eight environmental factors (multivitamin, folic acid and calcium supplementation history, maternal alcohol consumption, common cold history, maternal smoking and environmental tobacco smoke in the first trimester, and paternal smoking in the 3 months before pregnancy) among 294 case-parent trios and 183 individual controls in western Han Chinese to evaluate the relationship between EYA1, environmental factors, and NSOCs. To be better known the gene's role in the etiology of NSOCs, we performed statistical analysis in different aspects including the linkage disequilibrium test, transmission disequilibrium test, haplotype analysis, multiple logistic regression analysis, and conditional logistic regression analysis. RESULTS: Allele C at rs3779748 showed an over-transmission in NSCL/P trios (P = 0.03), and genotype A/A at rs10094908 was under-transmitted among NSCL/P trios (P = 0.03), whereas over-transmitted among NSCPO trios (P = 0.02). The haplotype GC of rs10094908-rs3779748 was over-transmitted among NSCL/P trios (P = 0.05) and NSCPO trios (P = 0.05), respectively. Maternal common cold history, environmental tobacco smoke, and maternal alcohol consumption during the first trimester of pregnancy were risk factors for NSOCs, while calcium supplementation during the first trimester showed a protective effect. No evidence of interactions between EYA1 and environmental factors was found. CONCLUSIONS: These results revealed an association between EYA1, some environmental factors, and NSOCs in western Han Chinese.


Subject(s)
Cleft Lip/genetics , Cleft Palate/genetics , Intracellular Signaling Peptides and Proteins/genetics , Nuclear Proteins/genetics , Protein Tyrosine Phosphatases/genetics , Alcohol Drinking , Alleles , Case-Control Studies , China , Cleft Lip/etiology , Cleft Palate/etiology , Environment , Female , Gene-Environment Interaction , Haplotypes , Heterozygote , Humans , Linkage Disequilibrium , Male , Polymorphism, Single Nucleotide , Pregnancy , Risk Factors , Tobacco Smoke Pollution
10.
Gene ; 533(1): 100-9, 2014 Jan 01.
Article in English | MEDLINE | ID: mdl-24120898

ABSTRACT

The white-backed planthopper (WBPH), Sogatella furcifera (Horváth), is one of the most destructive pests of rice crops in many Asian countries. Using long-PCR and shotgun library methods, we sequenced the entire mitochondrial genomes (mt-genomes) of two WBPH individuals. Total lengths of the mt-genome of the two WBPH individuals were 16,612 bp and 16,654 bp with an identical AT content of 76.19%. Among the 13 protein coding genes (PCGs), only nad5 used an atypical initiation codon GTG. Most of the tRNA genes had the typical cloverleaf secondary structure except that the dihydrouridine (DHU) arms in two trnS genes and the TΨC arm of trnG gene did not form a stable stem-loop structure. Similar to the brown planthopper (BPH), Nilaparvata lugens (Stål), and the small brown planthopper (SBPH), Laodelphax striatellus (Fallén), some extraordinary features were observed in the WBPH mt-genome. These include similar gene rearrangement pattern, unusually short length of the atp8 gene and variable numbers of tandem repeat (VNTR) structure in control region. Interestingly, the same tandem repeat unit with stable secondary structure appeared in two different planthoppers, WBPH and SBPH, which belong to two different genera of the Delphacidae. This peculiar feature provides a direct evidence for the close relationship between the two planthoppers and updates our understanding of the evolutionary characteristics of mitochondrial control region. Comparison with two other predominant rice planthoppers (BPH and SBPH) revealed that different PCGs of mitochondria exhibit different evolutionary patterns.


Subject(s)
Genome, Mitochondrial , Hemiptera/genetics , Animals , Base Sequence , Codon, Initiator , DNA Primers , Oryza , Polymerase Chain Reaction , RNA, Transfer/genetics
11.
BMC Genomics ; 14: 417, 2013 Jun 22.
Article in English | MEDLINE | ID: mdl-23799924

ABSTRACT

BACKGROUND: Nilaparvata lugens (the brown planthopper, BPH) and Laodelphax striatellus (the small brown planthopper, SBPH) are two of the most important pests of rice. Up to now, there was only one mitochondrial genome of rice planthopper has been sequenced and very few dependable information of mitochondria could be used for research on population genetics, phylogeographics and phylogenetic evolution of these pests. To get more valuable information from the mitochondria, we sequenced the complete mitochondrial genomes of BPH and SBPH. These two planthoppers were infected with two different functional Wolbachia (intracellular endosymbiont) strains (wLug and wStri). Since both mitochondria and Wolbachia are transmitted by cytoplasmic inheritance and it was difficult to separate them when purified the Wolbachia particles, concomitantly sequencing the genome of Wolbachia using next generation sequencing method, we also got nearly complete mitochondrial genome sequences of these two rice planthoppers. After gap closing, we present high quality and reliable complete mitochondrial genomes of these two planthoppers. RESULTS: The mitogenomes of N. lugens (BPH) and L. striatellus (SBPH) are 17, 619 bp and 16, 431 bp long with A + T contents of 76.95% and 77.17%, respectively. Both species have typical circular mitochondrial genomes that encode the complete set of 37 genes which are usually found in metazoans. However, the BPH mitogenome also possesses two additional copies of the trnC gene. In both mitochondrial genomes, the lengths of the atp8 gene were conspicuously shorter than that of all other known insect mitochondrial genomes (99 bp for BPH, 102 bp for SBPH). That two rearrangement regions (trnC-trnW and nad6-trnP-trnT) of mitochondrial genomes differing from other known insect were found in these two distantly related planthoppers revealed that the gene order of mitochondria might be conservative in Delphacidae. The large non-coding fragment (the A+T-rich region) putatively corresponding responsible for the control of replication and transcription of mitochondria contained a variable number of tandem repeats (VNTRs) block in different natural individuals of these two planthoppers. Comparison with a previously sequenced individual of SBPH revealed that the mitochondrial genetic variation within a species exists not only in the sequence and secondary structure of genes, but also in the gene order (the different location of trnH gene). CONCLUSION: The mitochondrial genome arrangement pattern found in planthoppers was involved in rearrangements of both tRNA genes and protein-coding genes (PCGs). Different species from different genera of Delphacidae possessing the same mitochondrial gene rearrangement suggests that gene rearrangements of mitochondrial genome probably occurred before the differentiation of this family. After comparatively analyzing the gene order of different species of Hemiptera, we propose that except for some specific taxonomical group (e.g. the whiteflies) the gene order might have diversified in family level of this order. The VNTRs detected in the control region might provide additional genetic markers for studying population genetics, individual difference and phylogeographics of planthoppers.


Subject(s)
Conserved Sequence/genetics , Gene Rearrangement/genetics , Genome, Mitochondrial/genetics , Genomics , Hemiptera/genetics , Mitochondrial Proton-Translocating ATPases/genetics , RNA, Transfer/genetics , Animals , Base Composition , DNA, Mitochondrial/chemistry , DNA, Mitochondrial/genetics , Gene Order/genetics , Genes, Mitochondrial/genetics , Hemiptera/enzymology , Molecular Sequence Data , Regulatory Sequences, Nucleic Acid/genetics , Species Specificity
12.
J Oral Pathol Med ; 42(9): 711-5, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23601008

ABSTRACT

BACKGROUND: Non-syndromic orofacial clefts (NSOC) are the most common craniofacial birth defects and are considered as complex and multifactorial diseases involving the interplay of genetic predisposition and environmental exposures. Recent studies demonstrated that EYA1, a member of eye absent gene family, might contribute to the development of orofacial clefts. This study aimed to evaluate the association between EYA1 gene polymorphism and NSOC in western Chinese population. METHOD: Two single-nucleotide polymorphisms, rs13260349 and rs2380716, were investigated among 199 case-parent trios, and the linkage disequilibrium (LD) test, transmission disequilibrium test, family based association test, and haplotype analysis were performed. RESULTS: Weak evidence of LD was found between these markers (D' = 0.573, r(2) = 0.218); allel C and genotype C/C at rs13260349 showed an overtransmission in CL/P; haplotype T-T (rs13260349-rs2380716) displayed an association with NSOC and CL/P. CONCLUSIONS: The results showed evidence of weak association between the two SNPs of EYA1 (rs13260349 and rs2380716) and NSOC.


Subject(s)
Cleft Lip/genetics , Cleft Palate/genetics , Ethnicity/genetics , Intracellular Signaling Peptides and Proteins/genetics , Nuclear Proteins/genetics , Polymorphism, Single Nucleotide/genetics , Protein Tyrosine Phosphatases/genetics , Alleles , China/ethnology , Cytosine , Female , Gene Frequency/genetics , Genotype , Haplotypes/genetics , Heterozygote , Homozygote , Humans , Introns/genetics , Linkage Disequilibrium/genetics , Male , Polymorphism, Restriction Fragment Length/genetics , Thymine
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(2): 370-3, 2012 Feb.
Article in Chinese | MEDLINE | ID: mdl-22512170

ABSTRACT

Visible/near-infrared (Vis/NIR) spectroscopy was investigated for the fast discrimination of rice leaves with different genes and the determination of chlorophyll content. Least squares-support vector machines (LS-SVM) was employed to discriminate transgenic rice leaves from non-transgenic ones. The classification accuracy of calibration samples reached to 100%. Successive projections algorithm (SPA) was proposed to select effective wavelengths. SPA-LS-SVM discrimination model was performed, and the result indicated that an 87.27% recognition ratio was achieved using only 0.3% of total variables. The optimal performance of each quantification model was achieved after orthogonal signal correction (OSA). Performances treated by SPA were better than that of full-spectrum PLS, which indicated that SPA is a powerful way for effective wavelength selection. The best performance of quantification was obtained by SPA-LS-SVM model; with correlation coefficient (R) and root mean square error of prediction (RMSEP) being 0.902 2 and 1.312 1, respectively. Excellent classification and prediction precision were achieved. The overall results indicated that the new proposed SPA-LS-SVM is a powerful method for varieties recognition and SPAD prediction. This study supplied a new and alternative approach to the further application of Vis/NIR spectroscopy in on-field classification and monitoring.


Subject(s)
Oryza , Plants, Genetically Modified , Spectroscopy, Near-Infrared , Algorithms , Calibration , Least-Squares Analysis , Models, Theoretical , Plant Leaves , Support Vector Machine
14.
Int J Mol Sci ; 13(3): 2863-2876, 2012.
Article in English | MEDLINE | ID: mdl-22489130

ABSTRACT

The western flower thrips, Frankliniella occidentalis (Pergande), is an invasive species and the most economically important pest within the insect order Thysanoptera. For a better understanding of the genetic makeup and migration patterns of F. occidentalis throughout the world, we characterized 18 novel polymorphic EST-derived microsatellites. The mutational mechanism of these EST-SSRs was also investigated to facilitate the selection of appropriate combinations of markers for population genetic studies. Genetic diversity of these novel markers was assessed in 96 individuals from three populations in China (Harbin, Dali, and Guiyang). The results showed that all these 18 loci were highly polymorphic; the number of alleles ranged from 2 to 15, with an average of 5.50 alleles per locus. The observed (H(O)) and expected (H(E)) heterozygosities ranged from 0.072 to 0.707 and 0.089 to 0.851, respectively. Furthermore, only two locus/population combinations (WFT144 in Dali and WFT50 in Guiyang) significantly deviated from Hardy-Weinberg equilibrium (HWE). Pairwise F(ST) analysis showed a low but significant differentiation (0.026 < F(ST) < 0.032) among all three pairwise population comparisons. Sequence analysis of alleles per locus revealed a complex mutational pattern of these EST-SSRs. Thus, these EST-SSRs are useful markers but greater attention should be paid to the mutational characteristics of these microsatellites when they are used in population genetic studies.


Subject(s)
Expressed Sequence Tags , Flowers/parasitology , Microsatellite Repeats/genetics , Thysanoptera/genetics , Animals , Base Sequence , Genetic Loci/genetics , Genetics, Population , Molecular Sequence Data , Mutation/genetics
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 29(11): 3011-4, 2009 Nov.
Article in Chinese | MEDLINE | ID: mdl-20101975

ABSTRACT

Ceria (CeO2) nanoparticles were prepared by precipitation method using cerium nitrate (Ce(NO3)3 x 6H2O) and ammonia (25 Wt%) as raw materials under the reaction for 3 h and ageing for 9 h at 80 degrees C without any surfactants and further calcination. The powder X-ray diffraction (XRD) pattern shows the as-prepared CeO2 crystals belong to the cubic phase and are well crystallized. Transmission electron microscopic (TEM) studies reveal that the appearance of as-prepared CeO2 is hexagonal, which is proposed to be the projection of polyhedral shape. The regular fringes spacing of 0.31 nm is in agreement with the d value of (111) lattice planes of cubic phase CeO2 from high-magnification TEM image. Reaction conditions such as the concentration of precipitant, reaction temperature and ageing duration exert important influence on the purity and morphology of the product. Ce(OH)3 was detected when the reaction was processed at lower pH (< 9) or with ageing duration less than 8 h at 80 degrees C. The size of polyhedral ceria nanoparticles increased with longer ageing time (> 15 h). If the reaction went on at a temperature lower than 40 degrees C, a large quantity of rodlike Ce(OH)3 was produced according to TEM observation. Raman spectra of CeO2 nanocrystallines exhibit a Raman shift at 465 cm(-1), corresponding to a F2g Raman band from the space group Fm3m of a cubic fluorite structure, while the Raman shift at about 600 cm(-1) may be attributed to the second Raman vibration mode of O2- vacancy due to Ce3+ impurity. Photoluminescence spectrum of CeO2 shows an emission at 465 nm at room temperature, which may be explained by charge transition from the 4f band to the valence band of CeO2.

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