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Graphical abstract LBP attenuated myocardial ischemia/reperfusion injury by restoring redox status, ultimately improving cardiac function. CAT: catalase; GPX: glutathione peroxidase; HO1: heme oxygenase 1; IL-6: interleukin-6; I/R: ischemia/reperfusion; LBP: Lycium barbarum polysaccharides; Nrf2: nuclear factor erythroid 2-related factor 2; NQO1: NADPH dehydrogenase quinone 1; ROS: reactive oxygen species; SOD: superoxide dismutase; TNF-α: tumor necrosis factor α., Highlights • LBP attenuated myocardial oxidative stress and apoptosis induced by I/R. • LBP improved cardiac function by reducing oxidative stress and apoptosis. • LBP ameliorated myocardial I/R injury via activation the Nrf2 signal pathway., Oxidative stress is considered to be one of main pathophysiological mechanisms in myocardial ischemia/reperfusion (I/R) injury. Lycium barbarum polysaccharides (LBP), the main ingredient of Lycium barbarum, have potential antioxidant activity. We aimed to investigate the effects of LBP on myocardial I/R injury and explore the underlying mechanisms. Myocardial I/R group was treated with or without LBP to evaluate oxidative stress markers and the role of Nrf2 signal pathway. Our results showed that I/R increased infarct size and the activities of creatine kinase (CK) and lactate dehydrogenase (LDH) when compared with control group. Meanwhile, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were enhanced and the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were decreased. These changes were associated with a significant increase in myocardial apoptosis, ultimately leading to cardiac dysfunction. LBP reduced infarct size (38.4 ± 2 % versus 19.4 ± 1.8 %, p < 0.05), CK and LDH activities and myocardial apoptotic index. Meanwhile, LBP suppressed the production of ROS and restored redox status. Additionally, LBP increased protein level of nuclear Nrf2 in vivo (2.1 ± 0.3 versus 3.8 ± 0.4, p < 0.05) and in vitro (1.9 ± 0.2 versus 3.8 ± 0.1, p < 0.05) and subsequently upregulated heme oxygenase 1 and NADPH dehydrogenase quinone 1 compared to I/R group. Interestingly, Nrf2 siRNA abolished the protective effects of LBP. LBP suppressed oxidative stress damage and attenuated cardiac dysfunction induced by I/R via activation of the Nrf2 antioxidant signal pathway.

It is generally believed that the right-handed circularly polarized (RCP) and left-handed circularly polarized (LCP) waves in an isotropic chiral medium propagate at different velocities, known as circular birefringence. Here we show that this is not the case. After obtaining the refraction and reflection coefficients of any elliptically polarized wave at the surface of a chiral medium, we derive the conditions for single-mode refraction. By means of the process of single-mode refraction, we demonstrate that both the refracted RCP and the refracted LCP waves at normal incidence can be expressed as a coherent superposition of a pair of orthogonal linearly polarized waves that are rotated simultaneously. As a result, they must propagate at the same velocity as the linearly polarized waves. A physical interpretation is also given in detail. In particular, we show that the state of polarization of any elliptically polarized wave in a chiral medium is rotated with propagation. Such a rotation amounts to the rotation of polarization bases without involving the change of the Jones vector. The rotation of the RCP and LCP waves, as special cases of elliptically polarized waves, results in two opposite phases as if they propagated at different phase velocities with their polarization states transmitted unchanged., 18 pages, 1 figure

One dimensional topological systems with extended periodically modulated parameters can be used to simulate and investigate two dimensional or other higher dimensional topological systems. In this paper, topological properties of an extended SSH model under the periodic δ-function kickings with X-direction, Y -direction, and Z-direction defined by pseudo-spin expression of the Hamiltonian in momentum space, has been explored. We find that, by modulating driven parameters and periodic δ-function kickings in such extended system, fruitful phase diagrams and topological states with higher Chern numbers can be introduced. In the case of X-direction kicking and Z-direction kicking, topological phase diagram will be changed but Chern numbers remain as 0 and ± 1, while for Y -direction kickings, large Chern numbers ± 2 can emerge. This is an extended study of using periodic kickings to obtain fruitful topological phases and large Chern number states in simulate two-dimensional systems.

Gutin and Rafiey (Australas J. Combin. 34 (2006), 17-21) provided an example of an n-partite tournament with exactly n − m + 1 cycles of length of m for any given m with 4 ≤ m ≤ n, and posed the following question. Let 3 ≤ m ≤ n and n ≥ 4. Are there strong n-partite tournaments, which are not themselves tournaments, with exactly n − m + 1 cycles of length m for two values of m? In the same paper, they showed that this question has a negative answer for two values n − 1 and n. In this paper, we prove that a strong n-partite tournament with exactly two cycles of length n − 1 must contain some given multipartite tournament as subdigraph. As a corollary, we also show that the above question has a negative answer for two values n − 1 and any l with 3 ≤ l ≤ n and l ≠ n − 1.

Oxidative stress induced by long-term cyclosporine A (CsA) administration is a major cause of chronic nephrotoxicity, which is characterized by tubular atrophy, tubular cell apoptosis, and interstitial fibrosis in the progression of organ transplantation. Although hydrogen-rich water (HRW) has been used to prevent various oxidative stress-related diseases, its underlying mechanisms remain unclear. This study investigated the effects of HRW on CsA-induced nephrotoxicity and its potential mechanisms. After administration of CsA (25 mg/kg/day), rats were treated with or without HRW (12 mL/kg) for 4 weeks. Renal function and vascular activity were investigated. Histological changes in kidney tissues were analyzed using Masson's trichrome and terminal deoxynucleotidyl transferase dUTP nick-end labeling stains. Oxidative stress markers and the activation of the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway were also measured. We found that CsA increased the levels of reactive oxygen species (ROS) and malonaldehyde (MDA), but it reduced glutathione (GSH) and superoxide dismutase (SOD) levels. Such alterations induced vascular dysfunction, tubular atrophy, interstitial fibrosis, and tubular apoptosis. This was evident secondary to an increase in urinary protein, serum creatinine, and blood urea nitrogen, ultimately leading to renal dysfunction. Conversely, HRW decreased levels of ROS and MDA while increasing the activity of GSH and SOD. This was accompanied by an improvement in vascular and renal function. Moreover, HRW significantly decreased the level of Keap1 and increased the expression of Nrf2, NADPH dehydrogenase quinone 1, and heme oxygenase 1. In conclusion, HRW restored the balance of redox status, suppressed oxidative stress damage, and improved kidney function induced by CsA via activation of the Keap1/Nrf2 signaling pathway.

Accurate dosimetry of a specific brain region in rats exposed to an electromagnetic field (EMF) is essential for studies focusing on dose-effect relationship of the region. However, only dosimetry of whole brain or whole body were evaluated in most of previous studies. In this study, a numerical voxel rat model with 10 segmented brain regions was constructed. Then, the effects of frequency, incidence direction, and E-polarization direction of plane wave EMF on brain region averaged specific absorption rate (BRSAR) of rats were investigated. At last, the reliability of using whole-body averaged SAR (WBDSAR) and whole-brain averaged SAR (WBRSAR) as estimations of BRSAR were also evaluated. Our results demonstrated that the BRSAR depended on the frequency, incidence direction, and E-polarization direction of the EMF. Besides, the largest deviation could be up to 13.1 dB between BRSAR and WBDSAR and 9.59 dB between BRSAR and WBRSAR. The results suggested that to establish an accurate dose-effect relationship, the variance of the BRSAR induced by alteration of frequency, incidence direction, and E-polarization direction of EMF should be avoided or carefully evaluated. Furthermore, the use of WBDSAR and WBRSAR as estimations of BRSAR should be restricted to certain conditions such that the deviations are not too large.

Oxidative stress plays an important role in pressure overload-induced cardiac remodeling. The purpose of this study was to determine whether apocynin, a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, attenuates pressure overload-induced cardiac remodeling in rats. After abdominal aorta constriction, the surviving rats were randomly divided into four groups: sham group, abdominal aorta constriction group, apocynin group, captopril group. Left ventricular pathological changes were studied using Masson’s trichrome staining. Metalloproteinase-2 (MMP-2) levels in the left ventricle were analyzed by western blot and gelatin zymography. Oxidative stress and apoptotic index were also examined in cardiomyocytes using dihydroethidium and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), respectively. Our results showed that abdominal aorta constriction significantly caused excess collagen deposition and cardiac insult. Treatment with apocynin significantly inhibited deposition of collagen and reduced the level of MMP-2. Furthermore, apocynin also decreased the NADPH oxidase activity, reactive oxygen species production and cardiomyocyte apoptotic index. Interestingly, apocynin only inhibited NADPH oxidase activity without affecting its expression or the level of angiotension II in the left ventricle. In conclusion, apocynin reduced collagen deposition, oxidative stress, and inhibited apoptosis, ultimately ameliorating cardiac remodeling by mechanisms that are independent of the renin-angiotensin system.

In a recent paper (2014 New J. Phys. 16 093008) Barnett discussed the so-called optical Dirac equation and referred to the involved wave function as a spinor. But as he claimed explicitly, he did not really associate that wave function with a true spinor. Here we show that if the optical Dirac equation is interpreted as the dynamical equation for the photon in conventional quantum mechanics, the wave function, called the photon field, does transform under the Lorentz transformation as a spinor. For the optical Dirac equation to be Lorentz covariant, however, a constraint on the photon field is required, which can be cast into the form of Maxwell’s divergence equations. It is found that the spinorial photon field not only satisfies the principle of locality but also has the right dimensionality as is required by conventional quantum mechanics.

Objective: To research and analyze the effect of psychological nursing intervention on selfrating depression (SDS), self-rating anxiety scale (SAS), Glasgow Score (GCS), Barthel index (Barthel, index, BI) of patients. Methods: From September 2015 to September 2016, 84 patients with craniocerebral injury admitted to our hospital were divided into observation group (n = 42) and control group (n = 42) according to randomized single blindness method. All patients were treated with hyperbaric oxygen therapy. The control group was given routine nursing care, while the observation group was treated by psychological nursing intervention. Results: The scores of GCS in the observation group after 2 weeks and 8 weeks of treatment were respectively (7.79±1.42), (11.86±2.56) which were higher than those in the control group (6.23±1.01), (8.21±1.65) the data show significant difference. After treatment, the scores of SDS and SAS in the observation group were respectively (39.14±1.21), (41.67±1.12) which were lower than those in the control group (45.56±2.50), (56.89±2.47) the data show significant difference. The BI index of the observation group was (43.29±4.63), which was higher than that of the control group (36.83±3.10), the scores of NFD was (23.12±1.01) in the observation group, which was lower than that in the control group (28.45±1.67), the data were statistically significant. Conclusion: Psychological care intervention in patients with craniocerebral injury treated by hyperbaric oxygen therapy is helpful to improve the adverse psychological state and consciousness state, improve the ability of daily living activities and promote the recovery of neurological function. It can be actively promoted and applied in clinical practice.

Since sewage irrigation can markedly disturb the status of heavy metals in soils, a convenient and accurate technique for heavy metal concentration estimation is of utmost importance in the cropland using wastewater for irrigation. This study therefore assessed the feasibility of visible and near infrared reflectance (VINR) spectroscopy for predicting heavy metal contents including Cr, Cu, Ni, Pb, Zn, As, Cd, and Hg in the north plain of Longkou city, Shandong Province, China. A total of 70 topsoil samples were taken for in situ spectra measurement and chemical analysis. Stepwise multiple linear regression (SMLR) and principal component regression (PCR) algorithms were applied to establish the associations between heavy metals and reflectance spectral data pretreated by different transformation methods. Based on the criteria that minimal root mean square error (RMSE), maximal coefficient of determination (R 2) for calibration, and greater ratio of standard error of performance to standard deviation (RPD) is related to the optimal model, SMLR model using first deviation data (RD1) provided the best prediction for the contents of Ni, Pb, As, Cd, and Hg, calibration using SNV data for Cr and continuum removal spectra for Zn, while PCR equation employed RD1 values was fit for prediction of the contents of Cu. The determination coefficients of all the reasonable models were beyond 0.6, and RPD indicated a fair or good result. In general, first deviation preprocessing tool outperformed other methods in this study, while raw spectra reflectance performed unsatisfactory in all models. Overall, VINR reflectance spectroscopy technique could be applicable to the rapid concentration assessment of heavy metals in soils of the study area.

Surface soils were collected from five types of land use in the northern plain of Longkou City and the contents of five heavy metals (Cu, Pb, Zn, Cd, and As) were determined. Based on results from preliminary studies on heavy metal pollution of soil, the potential ecological risks caused by heavy metals in the soil and risks to human health were evaluated using the Hakanson potential ecological risk assessment model after adjusting the evaluation threshold and the health assessment model after modifying parameters. The results show that the contents of five heavy metals in the study area exceed the background value, the potential ecological risk of Cd is high and complex, in irrigated land, orchard land, and bare land it is mostly the second-class risk, and urban industrial land and mining land are dominated by severe risk. The element As is equivalent to the first two levels of each land class; the minor risk areas of the other three types of heavy metals are larger than 70%. The comprehensive ecological risk of the five elements is higher than the three-level risk in the field, except for the bare ground. The area of four-level risk of urban industrial land and mining land is relatively large. The five types of soil heavy metals in this area present noncarcinogenic and carcinogenic risks to human health. The element Pb and heavy metal As, both entering the body by oral intake, pose a noncarcinogenic and carcinogenic risk to adults and children, respectively.

Objective: To study and analyze the effect of early psychological intervention on the scores of SAS and SDS in children with hypoxic-ischemic encephalopathy undergoing hyperbaric oxygen therapy. Methods: A total of 64 children with hypoxic - ischemic encephalopathy enrolled in our hospital from July 2015 to July 2016 and their parents were selected as study subjects. The patients were treated with hyperbaric oxygen therapy, while their parents were given early psychological intervention. By the way of increasing parents’ awareness of the disease, helping parents build confidence in their children’s treatment and encouraging them to participate in daily training for their children to relieve their anxiety and depression. The parents' knowledge of the disease before and during treatment, the treatment of hyperbaric oxygen therapy and the change of SAS and SDS were observed. Results: After effective intervention, the scores of SAS and SDS of 64 patients’ parents were significantly lower than those before treatment. After 1 courses of intervention, the score of SAS was (43.36 ± 1.27) points, and the score of SDS was (45.22 ± 8.13) points. After 2 courses of intervention, the score of SAS was (41.07 ± 1.21) and the score of SDS was (42.35 ± 7.44) points, and parents' awareness of hypoxic-ischemic encephalopathy was significantly increased, and the differences between the two groups were statistically significant. Conclusion: Early psychological intervention on parents of children with hypoxic-ischemic encephalopathy can effectively improve the awareness of parents on the disease, so as to improve their acceptance of hyperbaric oxygen therapy; significantly reduce the parents’ SAS, SDS score. It is beneficial to build a good doctor-patient and nurse-patient relationship, improve the treatment effect and shorten the treatment time.

Farmland soils in sewage irrigation area at Longkou City were collected, soil pH together with the heavy metal content were tested. Taking 70 soil points as the study object, this paper investigated the source of heavy metals in this area based on the correlation analysis and PCA of multivariate statistical analysis theory. We studied the spatial variation and distribution characteristics about heavy metals using both the theory of geostatistics and GIS spatial interpolation method. At last, the heavy metal pollution was evaluated in the way of Nemerow Index and improved fuzzy evaluation method. It turned out that, 9 kinds of heavy metal elements in the soil of research area had a certain degree of enrichment, among them the average of Cd was 3.06 times as high as the background value, and its enrichment was most severe. The result of Nemerow Index showed that, the values of comprehensive pollution index of Cu, Cd and Pb respectively were 7.06, 6.10 and 5.54, and they all belonged to high levels of pollution. According to the results of correlation analysis and principal component analysis, Cu, Zn together with Pb, Cd were mainly affected by human factors, sewage irrigation was their common pollution factor, the pollution sources for the first two heavy metals included excessive use of chemical fertilizers and pesticides in agricultural production and the accumulation of long time, whereas pollution from northern coal mining and coal gangue piled up as well as plating, machinery manufacturing and other industrial pollution were the pollution sources of the latter two elements. Other elements (Co, Cr, Mn, Ni and As) were mainly influenced by natural factors such as parent material. Comprehensive evaluation results showed that, among the 70 points, 13 points had moderate pollution,23 points belonged to light pollution, 28 points were at alert level, 6 points were in the safe range. From the perspective of spatial distribution,high value areas of heavy metal contents were mainly concentrated in towns of Zhuyouguan and Xufu. This showed that, sewage irrigation caused a certain degree of heavy metal pollution to local soil.

Albino tea cultivars are special mutants of tea plants with white or yellow leaf color. In this study, three albino tea cultivars, including 'Anji Baicha', 'Huangjinya', and 'Baijiguan', and two green tea cultivars, 'Longjing 43' and 'Fuding Dabaicha', were applied to metabolite profiling by gas chromatography-mass spectrometry and ultraperformance liquid chromatography-mass spectrometry. Multivariate analyses revealed significantly different metabolite phenotypes in leaves among albino cultivars and green cultivars. The differential metabolite-related pathways included galactose metabolism, tryptophan metabolism, phenylpropanoid biosynthesis, and flavonoid biosynthesis. For the young leaves of albino cultivars, the sugar (sorbitol and erythrose) and amino acid (mainly proline, isoleucine, ornithine, aspartic acid, threonine, and valine) concentrations increased, whereas gallocatechin and epigallocatechin gallate concentrations decreased. These results reveal the divergence in metabolic profiling between tea plant cultivars with different leaf colors. With the development of leaves, the concentrations of flavonoids increased largely in the older leaves of albino cultivars.

The tea plant ( Camellia sinensis (L.) O. Kuntze) is vulnerable to Ectropis oblique (Prout) (tea geometrids) in warm and humid climates. Therefore, tea plants have generated a series of mechanisms in response to the two stimuli related to E. oblique feeding: mechanical damage and oral secretion stimuli. To elucidate the molecular mechanisms underlying the responses to these distinct inducers, we employed RNA-sequencing (RNA-Seq) to compare three genome-wide expression profiles of a mechanically damaged plant, geometrid-damaged plant and undamaged control. Using the Illumina sequencing platform, we obtained approximately 304.54 million reads in total. These reads were assembled into 65,548 unigenes with an average length of 602 bp and an N50 of 860 bp. By comparing the profiles between the mechanically damaged plant and undamaged control, geometrid-damaged plant and undamaged control and geometrid-damaged plant and mechanically damaged plant, 33,418, 27,029 and 28,260 differentially expressed unigenes were identified, respectively. A comparison of the transcriptomes of the geometrid-damaged and mechanically damaged plants showed that 2995 unigenes were induced only by oral secretion stimuli. These unigenes exhibited significant differences in expression for the jasmonate/ethylene signaling and brassinosteroid pathways, terpenoid synthesis and phenylpropanoid biosynthesis, which are involved in defense against insect pests. Finally, reverse transcription PCR (RT-PCR) was used to verify the expression of preferentially expressed unigenes in the geometrid-damaged plant compared with that of the mechanically damaged plant as predicted by RNA-Seq. Our research yielded novel insights into the molecular mechanisms of pest resistance in tea plants and determined numerous genes and pathways that are involved in these processes. In addition, the expressed sequences were compiled to provide a valuable resource for the study of tea plant resistance to pests.

Drought is one of the major constraints for crop growth and productivity worldwide. Here, responses to soil drying and rewatering were measured at morphological, physiological and molecular levels in two adult field-grown tea plant [ Camellia sinensis (L.) O. Kuntze] cultivars including drought-susceptible ‘Zhuyeqi’ (T1) and drought-tolerant ‘Ningzhou 2’ (T2). After eight days drought stress (DS), most of leaves in T1 were reddish brown, curled and withered, whereas only a few needle spots and yellow patches were observed in T2. Based on the morphological symptoms, T2 recovered more quickly than T1. The malondialdehyde (MDA), soluble sugars (SS) and proline (Pro) contents as well as superoxide dismutase (SOD) and catalase (CAT) activities in two cultivars increased significantly as DS progressed and then rapidly decreased following rehydration. In contrast, the abscisic acid (ABA) and salicylic acid (SA) content peaked in the early stage of DS and then decreased rapidly, while these changes were more apparent in T2 than in T1. T1 had a higher concentration of MDA, SS and Pro than T2 throughout dehydration and rehydration. T2 was characterized by lower ABA and higher SA accumulation, but the opposite results were observed in T1. Furthermore, T2 had stable SOD and higher CAT activities during the stress and recovery. Under recovery rewatering, two cultivars still maintained high CAT activities. SS level in T1 was 1.2 times higher than control value on the fourth day after rehydration, while in T2 it was nearly equal to control level. In general, T2 showed more drastic changes in the expression of five selected genes during and after DS, these changes were positively correlated with corresponding physiological indicators. Nevertheless, expression levels of Δ 1 -pyrroline-5-carboxylate synthetase (P5CS) gene and phenylalanine ammonia lyase (PAL) gene in T1 were subjected to feedback inhibition. Overall, these findings were consistent with the results from the controlled indoor test and duplicate field test, providing new insights into the drought-tolerant mechanisms in tea plants.

Although a variety of functional metal-organic frameworks (MOFs) have been synthesized, post-modified, and applied in various areas, there is little knowledge about how molecular cluster building units are stepwise evolved into MOFs via intermediates. Coordination bonds are generally stronger than hydrogen bonds, and thus equivalent replacement of X-H···Y hydrogen bonds by X-M-Y coordination bonds can transform hydrogen bond networks into MOFs. In this work, solvothermal in situ reduction reactions of CuBr2 and 1,4-diazoniabicyclo[2,2,2]octane (DABCO) generated a myriad of tunable photoluminescent cuprous body-centered cubic bromide cluster-based networks with the general formula [Cu4+xH4-xBr6(DABCO)4](HCO2)2·S (x = 0, 0.56, 0.81, 1.27, 1.39, 2.56, 2.78, and 4 for compounds 1-8, respectively). All of these compounds crystallize in the cubic space group with the largest volume difference being only 5.2%, but they belong to three remarkably different kinds of crystals. Complex 1 is a molecular crystal and consists of tetrahedral [Cu4Br6(HDABCO)4](2+) clusters with monodentate HDABCO groups that are supported via N-H···Br synthons in the hydrogen bond network. Compound 8 is a [Cu8Br6](2+) cube cluster-based MOF with bridged DABCO ligands. Complexes 2-7 are seemingly impossible Cu/H-substituted solid solutions of 1 and 8. The CuBr framework components in 1-8 are Cu4Br6, Cu4.56Br6, Cu4.81Br6, Cu5.27Br6, Cu5.39Br6, Cu6.56Br6, Cu6.78Br6, and Cu8Br6, respectively. Crystallization kinetics studies revealed that the [Cu4Br6(HDABCO)4](2+) cluster-based hydrogen bond network (1) was initially formed such that N-H···Br hydrogen bonds could be stepwise replaced by N-Cu-Br coordination bonds to form the [Cu8Br6](2+) cube cluster-based MOF (8) via solid solutions. These observations directly reveal the equivalence and transformation between the N-H···Br hydrogen bond and the N-Cu-Br coordination bond and the evolutionary mechanism of a molecular crystal to a MOF via solid solutions, which is of fundamental importance in materials but has never before been revealed. DFT calculations suggest that equivalent replacement of a N-H···Br hydrogen bond by a N-Cu-Br coordination bond is exothermic and exergonic, which also supports the transformation from molecule 1 to MOF 8.

In the context of the era of speed economic, the airport as a quick means of transportation, promote the rapid flow of local people, capital, technology and other factors of production, promote local economic development, and development of the airport is also inseparable from the support of the local economy, Therefore, Use the airport and local economic data for data processing,and analyzing the degree of coupled development of airport and local economic scientifically, planning for further improving coordination between the airport and the city, and promoting coordinated development between them is important.

The cyclically modulated Su-Schrieffer-Heeger (SSH) chain systems with long-range hoppings, including the nearest-neighbor, the next-nearest-neighbor and the third-nearest-neighbor hoppings, have been proposed and investigated in this letter. The topological nontrivial phases characterized by Chern number have been obtained, showing a rich phase diagram in the two-dimensional space of the momentum and the modulation parameter. A similar shape of phase diagram but with different Chern numbers as Haldane model with long-range hoppings has been shown, and higher Chern numbers have been obtained and verified, indicating that more edge states can be obtained in such system.

Zn–Al layered double hydroxide (LDH) was used as precursor to produce ZnO nanostructures through dissolution of aluminum hydroxide in caustic soda. The Zn–Al LDH could transform into different nanostructures of ZnO on LDH nanosheets and even pure ZnO nanorods under various NaOH concentration. The formed ZnO nanorods vertically aligned on both LDH sides. UV–vis diverse reflectance spectra show that the obtained ZnO nanorods have a band gap of approximately 3.05 eV. Such ZnO/LDH nanostructures might be used as photocatalyst in the organic pollutant decomposition.

High-speed train air-conditioning systems put forward higher request on the aspect of air uniformity and comfort. The use of orifice which can form a more uniform velocity and temperature field in the car can be widely applied to high-speed train air-conditioning system. The experimental study of the influence of several different factors (such as the opening rate, aperture, orifice plate thickness, etc.) in the research may provide a reference for the design choices of the orifice type.

Background The new shoots of the albino tea cultivar ‘Anji Baicha’ are yellow or white at low temperatures and turn green as the environmental temperatures increase during the early spring. ‘Anji Baicha’ metabolite profiles exhibit considerable variability over three color and developmental stages, especially regarding the carotenoid, chlorophyll, and theanine concentrations. Previous studies focused on physiological characteristics, gene expression differences, and variations in metabolite abundances in albino tea plant leaves at specific growth stages. However, the molecular mechanisms regulating metabolite biosynthesis in various color and developmental stages in albino tea leaves have not been fully characterized. Results We used RNA-sequencing to analyze ‘Anji Baicha’ leaves at the yellow-green, albescent, and re-greening stages. The leaf transcriptomes differed considerably among the three stages. Functional classifications based on Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that differentially expressed unigenes were mainly related to metabolic pathways, biosynthesis of secondary metabolites, phenylpropanoid biosynthesis, and carbon fixation in photosynthetic organisms. Chemical analyses revealed higher β-carotene and theanine levels, but lower chlorophyll a levels, in the albescent stage than in the green stage. Furthermore, unigenes involved in carotenoid, chlorophyll, and theanine biosyntheses were identified, and the expression patterns of the differentially expressed unigenes in these biosynthesis pathways were characterized. Through co-expression analyses, we identified the key genes in these pathways. These genes may be responsible for the metabolite biosynthesis differences among the different leaf color and developmental stages of ‘Anji Baicha’ tea plants. Conclusions Our study presents the results of transcriptomic and biochemical analyses of ‘Anji Baicha’ tea plants at various stages. The distinct transcriptome profiles for each color and developmental stage enabled us to identify changes to biosynthesis pathways and revealed the contributions of such variations to the albino phenotype of tea plants. Furthermore, comparisons of the transcriptomes and related metabolites helped clarify the molecular regulatory mechanisms underlying the secondary metabolic pathways in different stages. Electronic supplementary material The online version of this article (doi:10.1186/s12870-016-0885-2) contains supplementary material, which is available to authorized users.

Tea plant (Camellia sinensis) is an economically important beverage crop. Drought stress (DS) seriously limits the growth and development of tea plant, thus affecting crop yield and quality. To elucidate the molecular mechanisms of tea plant responding to DS, we performed transcriptomic analysis of tea plant during the three stages [control (CK) and during DS, and recovery (RC) after DS] using RNA sequencing (RNA-Seq). Totally 378.08 million high-quality trimmed reads were obtained and assembled into 59,674 unigenes, which were extensively annotated. There were 5,955 differentially expressed genes (DEGs) among the three stages. Among them, 3,948 and 1,673 DEGs were up-regulated under DS and RC, respectively. RNA-Seq data were further confirmed by qRT-PCR analysis. Genes involved in abscisic acid (ABA), ethylene, and jasmonic acid biosynthesis and signaling were generally up-regulated under DS and down-regulated during RC. Tea plant potentially used an exchange pathway for biosynthesis of indole-3-acetic acid (IAA) and salicylic acid under DS. IAA signaling was possibly decreased under DS but increased after RC. Genes encoding enzymes involved in cytokinin synthesis were up-regulated under DS, but down-regulated during RC. It seemed probable that cytokinin signaling was slightly enhanced under DS. In total, 762 and 950 protein kinases belonging to 26 families were differentially expressed during DS and RC, respectively. Overall, 547 and 604 transcription factor (TF) genes belonging to 58 families were induced in the DS vs. CK and RC vs. DS libraries, respectively. Most members of the 12 TF families were up-regulated under DS. Under DS, genes related to starch synthesis were down-regulated, while those related to starch decomposition were up-regulated. Mannitol, trehalose and sucrose synthesis-related genes were up-regulated under DS. Proline was probably mainly biosynthesized from glutamate under DS and RC. The mechanism by which ABA regulated stomatal movement under DS and RC was partly clarified. These results document the global and novel responses of tea plant during DS and RC. These data will serve as a valuable resource for drought-tolerance research and will be useful for breeding drought-resistant tea cultivars.

Auxin response factor (ARF) proteins are a multigene family of regulators involved in various physiological and developmental processes in plants. However, their modes of action in the tea plant (Camellia sinensis) remain largely unknown. In this study, we identified 15 members of the tea ARF gene family, using the public information about C. sinensis, both in our laboratory, as well as in other laboratories, and analyzed their phylogenetic relationships, conserved domains and the compositions of the amino acids in the middle region. A comprehensive expression analysis in different tissues and organs revealed that many ARF genes were expressed in a tissue-specific manner, suggesting they have different functions in the growth and development processes of the tea plant. The expression analysis under three forms of auxin (indole-3-acetic acid, 2,4-dichlorophenoxyacetic acid, naphthylacetic acid) treatment showed that the majority of the ARF genes were down-regulated in the shoots and up-regulated in the roots, suggesting opposite action mechanisms of the ARF genes in the shoots and roots. The expression levels of most ARF genes were changed under various phytohormone and abiotic stresses, indicating the ARF gene family plays important roles in various phytohormone and abiotic stress signals and may mediate the crosstalk between phytohormones and abiotic stresses. The current study provides basic information for the ARF genes of the tea plant and will pave the way for deciphering the precise role of ARFs in tea developmental processes and breeding stress-tolerant tea varieties.