Transcriptomics and metabolomics reveal the mechanism of metabolites changes in Cymbidium tortisepalum var. longibracteatum colour mutation cultivars.

BACKGROUND: Foliage color is considered an important ornamental character of Cymbidium tortisepalum (C. tortisepalum), which significantly improves its horticultural and economic value. However, little is understood on the formation mechanism underlying foliage-color variations. METHODS: In this study, we applied a multi-omics approach based on transcriptomics and metabolomics, to investigate the biomolecule mechanisms of metabolites changes in C. tortisepalum colour mutation cultivars. RESULTS: A total of 508 genes were identified as differentially expressed genes (DEGs) between wild and foliage colour mutation C. tortisepalum cultivars based on transcriptomic data. KEGG enrichment of DEGs showed that genes involved in phenylalanine metabolism, phenylpropanoid biosynthesis, flavonoid biosynthesis and brassinosteroid biosynthesis were most significantly enriched. A total of 420 metabolites were identified in C. tortisepalum using UPLC-MS/MS-based approach and 115 metabolites differentially produced by the mutation cultivars were identified. KEGG enrichment indicated that the most metabolites differentially produced by the mutation cultivars were involved in glycerophospholipid metabolism, tryptophan metabolism, isoflavonoid biosynthesis, flavone and flavonol biosynthesis. Integrated analysis of the metabolomic and transcriptomic data showed that there were four significant enrichment pathways between the two cultivars, including phenylalanine metabolism, phenylpropanoid biosynthesis, flavone and flavonol biosynthesis and flavonoid biosynthesis. CONCLUSION: The results of this study revealed the mechanism of metabolites changes in C. tortisepalum foliage colour mutation cultivars, which provides a new reference for breeders to improve the foliage color of C. tortisepalum.

Parity-time symmetry light bullets in a cold Rydberg atomic gas.

A scheme is proposed to generate stable light bullets (LBs) in a cold Rydberg atomic system with a parity-time (PT) symmetric potential, by utilizing electromagnetically induced transparency (EIT). Using an incoherent population pumping between two low-lying levels and spatial modulations of control and auxiliary laser fields, we obtain a two-dimensional (2D) periodic optical potential with PT symmetry. Based on PT symmetry potential and the long-range Rydberg-Rydberg atomic interaction, the system may support slow LBs with low light intensity. Further, it is found that the local and non-local nonlinear coefficients and PT-symmetric potential can be tuned and used to manipulate the behavior of LBs.

A study on the clinical application of a patented perfusion and suctioning platform and ureteral access sheath in the treatment of large ureteral stones below L4 level.

PURPOSE: The purpose of the study was to evaluate the efficacy and safety of a patented perfusion and suctioning platform and ureteral access sheath in the treatment of large ureteral stones (≥ 1.5 cm) below L4 level. METHODS: We recruited 122 patients with large ureteral stones below L4 level at our hospital from December 2014 to June 2017. The patients were randomly divided into the study and control groups. Multiple operative and perioperative parameters were compared between the two groups. RESULTS: The study group had shorter operation time, less cases of postoperative fever, lower serum levels of PCT, IL-6 and BET within 24 h after surgery, as well as less number of cases receiving secondary surgery than the control group. Moreover, the former had a significantly higher stone clearance rate than the latter (P < 0.05; t-test or χ2 test). CONCLUSIONS: The patented perfusion and suctioning platform and ureteral access sheath are safe and effective in treating large ureteral stones (≥ 1.5 cm) below L4 level.

Abnormal resting-state functional network centrality in patients with high myopia: evidence from a voxel-wise degree centrality analysis.

AIM: To investigate the functional networks underlying the brain-activity changes of patients with high myopia using the voxel-wise degree centrality (DC) method. METHODS: In total, 38 patients with high myopia (HM) (17 males and 21 females), whose binocular refractive diopter were -6.00 to -7.00 D, and 38 healthy controls (17 males and 21 females), closely matched in age, sex, and education levels, participated in the study. Spontaneous brain activities were evaluated using the voxel-wise DC method. The receiver operating characteristic curve was measured to distinguish patients with HM from healthy controls. Correlation analysis was used to explore the relationship between the observed mean DC values of the different brain areas and the behavioral performance. RESULTS: Compared with healthy controls, HM patients had significantly decreased DC values in the right inferior frontal gyrus/insula, right middle frontal gyrus, and right supramarginal/inferior parietal lobule (P<0.05). In contrast, HM patients had significantly increased DC values in the right cerebellum posterior lobe, left precentral gyrus/postcentral gyrus, and right middle cingulate gyrus (P<0.05). However, no relationship was found between the observed mean DC values of the different brain areas and the behavioral performance (P>0.05). CONCLUSION: HM is associated with abnormalities in many brain regions, which may indicate the neural mechanisms of HM. The altered DC values may be used as a useful biomarker for the brain activity changes in HM patients.

Comparative transcriptome analysis provides global insight into gene expression differences between two orchid cultivars.

The orchids GL and YL are two cultivars of Cymbidium longibracteatum. YL displays an obviously yellowing rhizome and yellow leaves, while GL ('Longchangsu') shows dark green leaves and greenish rhizome. But the molecular mechanism for the differences between the two cultivars is poorly understood. In the present study, we showed that the structure of chloroplasts was significantly damaged in YL. Biochemical analysis uncovered the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid were notably decreased in YL. Using RNA-Seq technology, more than 38 million clean reads were generated in each pool, and 116,422 unigenes were assembled de novo. 6,660 unigenes with differential expression patterns (FDR≤0.01 and |log2 ratio|≥1) were totally identified between the two cultivars. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed unigenes (DEGs) suggested 33 KEGG pathways were notably enriched, including biological processes such as "phenylpropanoid biosynthesis", "phagosome", "starch and sucrose metabolism", "drug metabolism-cytochrome P450", "fatty acid elongation", and "flavone and flavonol biosynthesis". Further analysis revealed that chlorophyll degeneration related unigene (c48794_g1) and flavonoid biosynthesis related unigenes (c16388_g1, c48963_g1, c63571_g1, c4492_g1, c52282_g1, c78740_g1, c4645_g1) were up-regulated while carotenoid biosynthesis related unigene (c7212_g1) were down-regulated in YL. Additionally, six of NAC, R2R3-MYB, bHLH transcription factors (c42861_g1, c105949_g1, c61265_g1, c42659_g1, c82171_g1, c19158_g1) might be involved in regulation of pigment biosynthesis. The chlorophyll degeneration and the flavonoid biosynthesis related unigenes up-regulation together with the carotenoid biosynthesis related unigenes down-regulation may contribute to the yellowing phenotype of YL.

Comparative analysis of IDF, ATPIII and CDS in the diagnosis of metabolic syndrome among adult inhabitants in Jiangxi Province, China.

BACKGROUND: Currently, the prevalence of metabolic syndrome (MS) has attracted widespread public attention. However, there is a war regarding the applicability of the diagnosis in different populations regarding the distinct criteria for the diagnosis of MS. Data about the prevalence rate of MS and its components in Jiangxi Province are limited. Thus, our goals were to compare the consistency rates and applicability of three criteria, i.e., those of the International Diabetes Federation (IDF), the National Cholesterol Education Program Adult Treatment PanelⅢ (ATPⅢ), and the Chinese Diabetes Society (CDS). METHODS: From September 2013 to March 2014, 5959 residents (age≥18 years) from Jiangxi Province were selected by multistage stratified cluster random sampling methods. The prevalence rate of MS and its components were calculated according to the IDF, ATPⅢ and CDS criteria, and the protocols of the different criteria were measured in terms of consistency with the kappa statistic and Youden's index. Receiver operator characteristic (ROC) curve analysis was used to explore the optimal cut-off points of body mass index (BMI) and waist circumference (WC). RESULTS: The mean age of the participants was 50.52±13.92 years among the total of 5959 individuals (2451 male and 3508 female). The standardized prevalence rate of MS was 19.85%, 24.77% and 9.95% according to the IDF, ATPⅢ and CDS criteria, respectively. The order of the prevalence rates of the different components of MS according to the IDF or ATPⅢ criteria from high to low were as follows: elevated blood pressure, central obesity, reduced high density lipoprotein cholesterol (HDL-C), hyperglycemia, and hypertriglyceridemia. The most prevalent component of MS, according to the CDS criterion, was being overweight or obese, followed by elevated blood pressure, dyslipidemia and hyperglycemia. The Youden's index in IDF criterion was higher than which in CDS criterion (0.79 for IDF vs. 0.38 for CDS) referring to the ATPⅢ criterion. The agreement between the IDF and ATPⅢ criteria was good (kappa = 0.85), whereas the agreement of the CDS with the IDF and ATPⅢ criteria was moderate (kappa = 0.46 and 0.46, respectively). The ability to predict MS risk factors clusters was superior when the BMI cut-off point was 24/24kg/m2 (male/female), and the WC cut-off point was 87/80cm (male/female). Among the 18~59 years old male group, BMI was superior to WC in predicting clusters of risk factors for MS; while in the 60 years and above male group and all-age female group, WC was superior to BMI. CONCLUSION: Our results revealed that the prevalence rate of metabolic syndrome among adults was high in Jiangxi Province. BMI and WC had different ability to predict clusters of risk factors for MS in different age groups and gender. Among the three criteria for MS, there was bigger difference in applicability for the adults of Jiangxi Province. The choice of the appropriate criteria should be based on the actual conditions of the site.

Light bullets in coupled nonlinear Schrödinger equations with variable coefficients and a trapping potential.

We analyze three-dimensional (3D) vector solitary waves in a system of coupled nonlinear Schrödinger equations with spatially modulated diffraction and nonlinearity, under action of a composite self-consistent trapping potential. Exact vector solitary waves, or light bullets (LBs), are found using the self-similarity method. The stability of vortex 3D LB pairs is examined by direct numerical simulations; the results show that only low-order vortex soliton pairs with the mode parameter values n ≤ 1, l ≤ 1 and m = 0 can be supported by the spatially modulated interaction in the composite trap. Higher-order LBs are found unstable over prolonged distances.

Self-similar asymptotic optical beams in semiconductor waveguides doped with quantum dots.

The self-similar propagation of asymptotic optical beams in semiconductor waveguides doped with quantum dots is reported. The possibility of controlling the shape of output asymptotic optical beams is demonstrated. The analytical results are confirmed by numerical simulations. We give a possible experimental protocol to generate the obtained asymptotic parabolic beams in realistic waveguides. As a generalization to the present work, the self-similar propagation of asymptotic optical beams is proposed in a power-law nonlinear medium.

Self-similar propagation and asymptotic optical waves in nonlinear waveguides.

The properties of self-similar optical waves propagating in a tapered cubic-quintic nonlinear waveguide are investigated. Using a lens-type transformation we obtain the exact analytical self-similar solutions which describe the propagation of bright-shaped solitons, dark-shaped solitons, kink-shaped solitons, and antikink-shaped solitons. The stability of the solutions is examined by numerical simulations such that stable bright solitons are found. Beyond the exact analytical solutions, asymptotic optical waves are also found by employing a direct ansatz. These waves possess linear chirps and can propagate self-similarly. The possibility of controlling the shape of output asymptotic optical waves is demonstrated. The analytical results are confirmed by numerical simulations. Finally, we investigate the generation and propagation properties of self-similar optical waves in a quintic nonlinear medium.

Genetic diversity and population structure of Miscanthus sinensis germplasm in China.

Miscanthus is a perennial rhizomatous C4 grass native to East Asia. Endowed with great biomass yield, high ligno-cellulose composition, efficient use of radiation, nutrient and water, as well as tolerance to stress, Miscanthus has great potential as an excellent bioenergy crop. Despite of the high potential for biomass production of the allotriploid hybrid M. ×giganteus, derived from M. sacchariflorus and M. sinensis, other options need to be explored to improve the narrow genetic base of M. ×giganteus, and also to exploit other Miscanthus species, including M. sinensis (2n = 2x = 38), as bioenergy crops. In the present study, a large number of 459 M. sinensis accessions, collected from the wide geographical distribution regions in China, were genotyped using 23 SSR markers transferable from Brachypodium distachyon. Genetic diversity and population structure were assessed. High genetic diversity and differentiation of the germplasm were observed, with 115 alleles in total, a polymorphic rate of 0.77, Nei's genetic diversity index (He) of 0.32 and polymorphism information content (PIC) of 0.26. Clustering of germplasm accessions was primarily in agreement with the natural geographic distribution. AMOVA and genetic distance analyses confirmed the genetic differentiation in the M. sinensis germplasm and it was grouped into five clusters or subpopulations. Significant genetic variation among subpopulations indicated obvious genetic differentiation in the collections, but within-subpopulation variation (83%) was substantially greater than the between-subpopulation variation (17%). Considerable phenotypic variation was observed for multiple traits among 300 M. sinensis accessions. Nine SSR markers were found to be associated with heading date and biomass yield. The diverse Chinese M. sinensis germplasm and newly identified SSR markers were proved to be valuable for breeding Miscanthus varieties with desired bioenergy traits.

Analytical solitary-wave solutions of the generalized nonautonomous cubic-quintic nonlinear Schrödinger equation with different external potentials.

A large family of analytical solitary wave solutions to the generalized nonautonomous cubic-quintic nonlinear Schrödinger equation with time- and space-dependent distributed coefficients and external potentials are obtained by using a similarity transformation technique. We use the cubic nonlinearity as an independent parameter function, where a simple procedure is established to obtain different classes of potentials and solutions. The solutions exist under certain conditions and impose constraints on the coefficients depicting dispersion, cubic and quintic nonlinearities, and gain (or loss). We investigate the space-quadratic potential, optical lattice potential, flying bird potential, and potential barrier (well). Some interesting periodic solitary wave solutions corresponding to these potentials are then studied. Also, properties of a few solutions and physical applications of interest to the field are discussed. Finally, the stability of the solitary wave solutions under slight disturbance of the constraint conditions and initial perturbation of white noise is discussed numerically; the results reveal that the solitary waves can propagate in a stable way under slight disturbance of the constraint conditions and the initial perturbation of white noise.