[Effect of soil moisture on water potential gradients in the soil-plant-atmosphere continuum (SPAC) of apple orchards in the Loess Plateau, Northwest China]. / 土壤水分对黄土区苹果园土壤-植物-大气连续体(SPAC)中水势梯度的影响.

The variations of water potential gradients through the soil-plant-atmosphere continuum (SPAC) are of great significance to reveal the responses of plant water use to environmental changes. We conducted a continuous experiment to monitor the potentials in the near-canopy atmosphere (Ψair), soil (Ψsoil) and plant xylems (Ψstem) during the growing season in an apple orchard located in the Loess Plateau. The results showed that the average Ψstem during the growing season ranged from -0.24 to -2.0 MPa, with a mean value of -0.57 MPa. The average water potential gradient in soil-plant-atmosphere system was 1:9.8:1155 (Ψsoil:Ψstem:Ψair). We found a significant positive linear correlation between the Ψstem:Ψsoil gradient and volumetric soil water content (VWC, %). The Ψstem was more strongly correlated with Ψsoil than Ψair. Moreover, the sensitivity of Ψstem to Ψsoil decreased when Ψsoil was lower than -0.08 MPa which corresponded to VWC=17%, 0.56 times of field capacity. This was reflected by the increased linearity between Ψair /Ψstem and Ψsoil as Ψsoil decreased. There was a threshold effect for the relationship between Ψair and Ψstem. That is, the Ψstem in a day increased with the increasing of Ψair before the latter reached -69 MPa, after which the Ψstem decreased. The decline of soil water content caused an obvious decrease in water potential gradient through the SPAC system, and the threshold effect existed when VWC was below 17%. The results provide a basis for understanding the mechanisms of plant water in response to soil and atmospheric drought.

Sesquiterpenoids from Artemisia vestita and Their Antifeedant and Antifungal Activities.

Four new sesquiterpenoids, named artemivestinolide D-G (1-4) and three known sesquiterpenoids (5-7), were isolated from Artemisia vestita. The structures of these new compounds were determined based on extensive spectroscopic data analyses. Furthermore, the electronic circular dichroism data determined the absolute configurations of the new compounds. The antifeedant and antifungal activities of the isolates were evaluated against third-instar larvae of Plutella xylostella and three plant pathogenic fungi. Compounds 1-7 showed moderate antifeedant activities and compounds 1-4 and 6-7 exhibited antifungal activities.

Response of sap flow rate of apple trees to environmental factors in Loess Platea of Western Shanxi Province, China.

To clarify the effects of environmental factors on transpiration process of apple trees in rain-fed ecosystem, the dynamics of sap flow in apple trees from Loess Plateau area in western Shanxi Province of China were monitored using the thermal diffusion technique. Meanwhile, environmental factors including meteorological elements and soil moisture content were measured. The results showed that both net solar radiation (Rn) and atmospheric vapor deficit (VPD) were closely correlated with sap flow rate (Js), as the main ones among all the measured environmental factors. At both hourly and daily scales, the cumulative variances of the three principal components of the environmental factor were above 86%. The first principal component contained VPD and Rn, and explained the variance of over 52% (at hour scale) and 63% (at daily scale), which could be classified as the evaporation demand index (EDI) and as the key comprehensive environmental varia-bles affecting tree sap flow. The second principal component mainly included soil moisture content (SWC) and other factors, which were referred to the soil water and heat supply index. The third principal component mainly included wind speed and other factors, and could be classified into the hydrothermal dissipation index. At the scale of hourly or daily, the response of Js to EDI showed a significant exponential growth relationship. At the hourly time scale, Js of apple trees could be accurately modelled based on the first principal component EDI (R2=0.72). At the daily scale, Js of apple trees could be better modelled based on potential evapotranspiration (ET0) (R2=0.88). Our results were of great significance for clarifying the responses of water transport in apple tree to environmental factors, estimating water consumption of apple tree based on meteorological factors, as well as directing orchard water management.

Prevalence of celiac disease in patients with Down syndrome: a meta-analysis.

BACKGROUND: The association between Down syndrome and celiac disease has been reported by many studies. However, the prevalence of celiac disease (CD) in Down syndrome (DS) varies considerably across studies (from 0 % to 19 %). The aim of this study was to use meta-analysis to exam the prevalence of CD in patients with DS. METHODS: A systematic search of English articles from Pubmed, Web of Science and CNKI without year limitation. Data were extracted by two independent observers and pooled using a random effects model by the Comprehensive Meta-Analysis Version 2 software. RESULTS: A pooled analysis, based on 31 studies included 4383 individuals, revealed prevalence of biopsy-confirmed CD of 5.8 % (95 % CI = 4.7-7.2 %) in patients with DS. Sub-group analysis showed a slightly higher prevalence of CD in children with DS (6.6 %; 17 studies), than in age mixed samples with both children and adults (5.1 %; 13 studies). In addition, most of the studies included in this meta-analysis were from Europe and America, with the prevalence of celiac disease of 6 % (21 studies) and 5.7 % (6 studies) in DS patients, respectively. Furthermore, meta-regression analysis suggested that proportion of antibody-positive individuals that underwent small intestine biopsy had moderating effect on the outcome of the meta-analysis. CONCLUSIONS: These results demonstrated that patients (children) with Down syndrome had high prevalence of CD (more than one in twenty). The prevalence is high enough to motivate screening CD in DS children.

Oleanane-Type Saponins from the Roots of Ligulariopsis shichuana and Their α-Glucosidase Inhibitory Activities.

Five new oleanane-type saponins, named ligushicosides A-E, and three known oleanane-type saponins were isolated from the roots of Ligulariopsis shichuana. Their structures were established by a combination of spectroscopic techniques, including 1D and 2D NMR and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Furthermore, all isolates were evaluated for their yeast α-glucosidase inhibitory effects and exhibited potent inhibition against α-glucosidase, while compounds 1 and 2 showed excellent inhibitory activities. The 3-O-glycoside moiety in oleanane-type saponin is important for the α-glucosidase inhibitory effects.

Association of Peripheral Blood Levels of Brain-Derived Neurotrophic Factor With Autism Spectrum Disorder in Children: A Systematic Review and Meta-analysis.

Importance: Accumulating evidence suggests that brain-derived neurotrophic factor (BDNF) may be implicated in the developmental outcomes of children with autism spectrum disorder (ASD). Objective: To use meta-analysis to determine whether children with ASD have altered peripheral blood levels of BDNF. Data Source: A systematic search of PubMed, PsycINFO, and Web of Science was performed for English-language literature through February 7, 2016. The search terms included brain-derived neurotrophic factor or BDNF in combination with autism, without year restriction. Two additional records were retrieved after a review of the reference lists of selected articles. Study Selection: Studies were included if they provided data on peripheral blood levels of BDNF in children with ASD and healthy control children. Studies that included adults or with overlapping samples were excluded. Data Extraction and Synthesis: Data were extracted by 2 independent observers from 19 included studies. Data were pooled using a random-effects model with Comprehensive Meta-analysis software. Main Outcomes and Measures: Blood levels of BDNF in children with ASD compared with healthy controls. Altered levels of BDNF were hypothesized to be related to ASD. Results: This meta-analysis included 19 studies with 2896 unique participants. Random-effects meta-analysis of all 19 studies showed that children with ASD had significantly increased peripheral blood levels of BDNF compared with healthy controls (Hedges g, 0.490; 95% CI, 0.185-0.794; P = .002). Subgroup analyses in 4 studies revealed that neonates diagnosed with ASD later in life had no association with blood levels of BDNF (Hedges g, 0.384; 95% CI, -0.244 to 1.011; P = .23), whereas children in the nonneonate ASD group (15 studies) demonstrated significantly increased BDNF levels compared with healthy controls (Hedges g, 0.524; 95% CI, 0.206 to 0.842; P = .001). Further analysis showed that children in the nonneonate ASD group had increased BDNF levels in serum (10 studies) (Hedges g, 0.564; 95% CI, 0.168 to 0.960; P = .005) but not in plasma (5 studies) (Hedges g, 0.436; 95% CI, -0.176 to 1.048; P = .16). Meta-regression analyses revealed that sample size had a moderating effect on the outcome of the meta-analysis in the nonneonate group. In addition, no publication bias was found in the meta-analysis. Conclusions and Relevance: Children with ASD have increased peripheral blood levels of BDNF, strengthening the clinical evidence of an abnormal neurotrophic factor profile in this population.

Methane emissions from the trunks of living trees on upland soils.

Upland forests are traditionally thought to be net sinks for atmospheric methane (CH4 ). In such forests, in situ CH4 fluxes on tree trunks have been neglected relative to soil and canopy fluxes. We measured in situ CH4 fluxes from the trunks of living trees and other surfaces, such as twigs and soils, using a static closed-chamber method, and estimated the CH4 budget in a temperate upland forest in Beijing. We found that the trunks of Populus davidiana emitted large quantities of CH4 during July 2014-July 2015, amounting to mean annual emissions of 85.3 and 103.1 µg m(-2)  h(-1) on a trunk surface area basis on two replicate plots. The emission rates were similar in magnitude to those from tree trunks in wetland forests. The emitted CH4 was derived from the heartwood of trunks. On a plot or ecosystem scale, trunk CH4 emissions were equivalent to c. 30-90% of the amount of CH4 consumed by soils throughout the year, with an annual average of 63%. Our findings suggest that wet heartwoods, regardless of rot or not, occur widely in living trees on various habitats, where CH4 can be produced.

[Ecological characteristics of preferred habitat of reindeer of Daxing'an Mountain forest area Northeast China in summer].

In July and August of 2012 and 2013, habitat selection and use patterns of reindeer were studied using both line and strip-transect surveys. Twenty-three habitat factors were measured and compared in known reindeer range areas in northwestern China. A total of 72 sampling sites were designated as being used by reindeer, and 162 sites were designated as unused control plots. The results indicated that, compared to the non-used habitat plots, reindeer selected summer habitats with higher values in altitude (26.9 ± 0.8 m), arbor canopy (17.9% ± 2.4%), arbor DBH (35.5 ± 2.1 cm), arbor height (8.2 ± 0.5 m), arbor density (6.9 ± 0.5 ind · 400 m(-2)) and stump quan- tity (1.3 ± 0.2 ind · 400 m(-2)), and with a lower shrub height (54.2 ± 2.0 cm). Moreover, reindeer also selected habitats at intermediate positions of intermediate slope gradient, which provided good water accessibility, more distance from human disturbance and herder influence, but bad concealment and lee condition. Results of the principal component analysis showed that the disturbance intensity (i. e. residential dispersion, anthropogenic-disturbance dispersion), arbor characteristics (arbor height and arbor density, arbor DBH and arbor canopy), geography characteristics (i. e. slope position, slope aspect and soil moisture), food abundance (ground-plant cover and shrub cover), openness (concealment and lee condition) and slope gradient were the most important factors influencing the habitat selection of reindeer in summer. In summary, the summer habitat selection of reindeer is a multidimensional process, through which reindeer adapt according to their ecological needs of food resources, safety and anti-predation. Furthermore, the pattern of habitat selection of reindeer showed that reindeer in China has not yet been domesticated, and reindeer populations and their core habitats should be conserved from intensive disturbance.

[Surfactant-assisted solid-phase synthesis and spectral characterization of silver iodide nanowire bundles].

In the present paper, AgNO3 and KI were used as raw materials synthesize silver iodide nanowire bundles in the condition of nonionic surfactant polyethylene glycol (PEG-400) at room temperature. XRD, TEM and SEM techniques were used to characterize the silver iodide structure and morphology. The results indicated that the product was one-dimensional silver iodide nanowire bundles with diameters of 80-100 nm and lengths of 20 microm, and the length-diameter ratio was greater than 200. In the forming process of silver iodide nanowire bundles, PEG-400 surfactant was used as soft template agent, which induced the product nanocrystalline along a particular direction and directional orderly growth so as to generate nanowire bundles. This method with a simple operation and low cost eliminated the influence of water on the reaction process.

[Preparation by template method and spectral characterization of α-MoO3 nanorods and nanometer rectangular pieces].

α-MoO3 was paid special attention to nano scale with its layered crystal structure and potential applications in material chemistry fields. In the present paper, (NH4)6 Mo7O24 x 4H2O and hexadecyl trimethyl ammonium bromide (CTAB) were proposed as molybdenum precursor and template agent, respectively, and the precursor was prepared by statistic ion exchange with strong acidic ion exchange resin (R-H). The precursor can be transformed into alpha-MoO3 nanorods and nanometer rectangular small pieces via calcining precursor at 600 degrees C for different times. The phasestate, structure and morphology of samples were identified by FTIR, XRD, TEM and SEM. The α-MoO3 nanorods with the length of about 1-1.6 microm, the diameter of about 0. 10-0. 20 microm and the ratio of length to diameter of 8, and the nanometer rectangular small pieces with the length of about 0. 14-0. 18 microm, the width of about 60-80 nm and the thickness of 28-32 nm, were obtained after 600 degrees C sintering for 4 and 8 h. This preparation procedure is simple, without the need for artificially adjusting the pH, redundantly washing can be avoided, the resin can be regenerated and NH4 Cl was recycled without environmental pollution.

Two new compounds from Comastoma pedunlulatum.

Two new compounds, a xanthonoid and a flavonoid C-glycoside, were isolated from the ethyl acetate extract of the dried herb of Comastoma pedunlulatum. The structures of the new compounds were elucidated, respectively, as 1,8-dihydroxy-3,5-dimethoxyxanthone 1-O-[2-(4'-hydroxy-3',5'-dimethoxy-E-cinnamoyl)]-ß-D-xylopyranosyl-(1-6)-ß-D-glucopyranoside (1) and 6″-O-acetylisoorientin (2) on the basis of their spectroscopic and physicochemical properties.

[Summer habitat selection of alpine musk deer in Xinglongshan National Nature Reserve, Northwestern China].

During July and August from 2006 to 2008, summer habitat selection was studied in Alpine musk deer (Moschus sifanicus) in Xinglongshan National Natural Reserve in northwestern China. In total, seventy one musk deer utilized habitat plots and 246 random habitat plots were surveyed. Seventeen habitat characteristics were recorded and compared between the two habitat types, using Mann-Whitney U test and chi-square to compare the differences between utilized and random habitat plots, and principal component analysis (PCA) to determine the main factors influencing the habitat selection of musk deer. Mann-Whitney U test and chi-square was conducted to test whether there was significant difference between utilized and random plots. The results showed that musk deer prefers habitat with taller arbor height (7.57 +/- 0.83 ) m, higher food-plants abundance (12.97 +/- 1.80), increasing foliage cover for concealment, lower water dispersion, and higher anthropogenic disturbance. Furthermore, PCA results suggested that the arbor characteristics (arbor canopy and arbor DBH), altitude characteristic, food characteristics (ground-plant cover and food-plant abundance) and shrub characteristics (shrub canopy, shrub height and related arbor density) influence summer habitat selection patterns of alpine musk deer in Xinglongshan National Nature Reserve. The general pattern of summer habitat utilization and selection of alpine musk deer is an adaptive strategy to the changing food, concealment, water source and the physical condition of summer habitat.

A new jacaranone derivative from Senecio scandens var. incisus.

A new jacaranone derivative, 2-(1,6-dihydroxy-4-oxocyclohex-2-enyl) acetic acid (1), has been isolated from the whole plants of Senecio scandens var. incisus, together with three known compounds: 2'-(p-hydroxyl-cinnamoyl)-6'-jacaranone-D-glucopyranoside (2), 2'-caffeoyl-6'-jacaranone-D-glucopyranoside (3) and kampferol-3-rhamnoside (4). Their structures were elucidated on the basis of spectroscopic data analyses and by comparison with the related known compounds. Cytotoxic activities of 1 against three human tumour cell lines have been evaluated by the MTT method.

[Application of fluorescence microscopic imaging technique with self-ordered ring to residues detection of antibiotics].

Fluorescence microscopic self-ordered ring (SOR) technique with microwave heating is proposed for minocycline based on the capillary flow of solvent on the surface of hydrophobic glass slide and applied to residues detection of the antibiotics in milks of Inner Mongolia. In the reaction medium of hexahydropyridine containing polyvinyl alcohol-124 (PVA-124), a SOR of minocycline with the outer diameter of 1.54 mm and the ring belt width of 22.6 microm can be formed. When a 0.30 microL droplet of minocycline mixture was spotted on the solid surface, minocycline in the range of 4.2 x 10(-2)-1.8 x 10(-11) mol x ring(-1) (1.4 x 10(-6)-0.60 x 10(-5) mol x L(-1)) can be detected, the maximum fluorescence intensity was found to be proportional to the minocycline concentration, and the limit of detection can reach 4.2 x 10(-13) mol x ring(-1) (1.4 x 10(-7) mol x L(-1)) with three times of signal to noise ratio. With the present method, the contents of minocycline in milk samples of Inner Mongolia and minocycline hydrochloride capsule sample were satisfactorily determined with recoveries of 97.2%-103% and 99.4%-102%, respectively, and RSD lower than 1.2%, correspondingly. Therefore, a highly sensitive and selective analysis method for detecting content of trace drug contaminations was established. The method provided theory basis to quantificational analysis of the residues of the antibiotics in milks which was Inner Mongolia' preponderant resource products. It has important realistic meaning and broad application prospect.

[Determination of nutrients in 7 species of desert plants for raising livestock in inner Mongolia].

In order to accumulate the foundational information about the nutrients related to 7 species of desert plants, chemical and instrumental methods for determination were used and quantitative results were obtained as follows (%, in dry mass): calcium 0.73-3.89, phosphorus 0.043-0.34, selenium 0.026-2.8, protein 3.38-13.92, lipid 3.97-15.03, total sugar 14.89-35.78, ash 0.61-14.33, medium washing fiber 26.66-79.72, and acid washing fiber 27.03-69.01. Among the 7 species of desert plants, the total content of amino acid in the leaf and caudex ranges from 2.30% to 11.26%. Apart from Elaeagnus angusti folia, the ratios of the calcium and phosphorus both in the leaves and caudexes of the rest 6 kinds of desert plants are higher than those in the leaf powder and caudex powder of clover blossom. The selenium content is greater than the usual amount in plants; the protein content reaches the level of excellent grains; the lipid contents in leaf, caudex and whole plant are higher than those in straws of corn and wheat; the leaves have more total sugar than the caudex and the whole plant, and the high level of ash content exists in the 7 species of desert plants; and the medium washing fiber content in leaf of those plants is lower than that in clover blossom leaf powder, which is opposite to the content in caudex. Except for Haloxylon ammodendron, the acid washing fiber content in caudexes is beyond that in the caudex powder of the clover blossom. As is indicated in the data above, the 7 species of desert plants not only do meet the demands of raising livestock, but also are ideal feeding resources for the husbandry development in sandy areas.

[Preparation of Nd2O3 nanoparticles by ion exchange resin homogenous precipitation method].

In the present paper, homogenous precipitation with Nd(NO)3.6H2O and (NH)2CzO4.2H2O, a strong base anion exchange resin and strong acidic cation exchange resin, respectively, and subsequent calcination of precursors at 700 C were used to synthesize Nd2O3 nanoparticles. In the precipitation from homogeneous solution, the relative supersaturation is always low and the local reagent excesses do not occur because the precipitating agent appears homogeneously throughout the entire solution. In general, homogeneous precipitates are better suited for analysis than precipitates formed by direct addition of a reagent. The concentration of reactant, reaction temperature and time are important factors which dominate the morphology and structure size of the Nd2O3 nanoparticles. Assay results showed that between 40 and 50 degrees C, when the ion exchange resin was added tardily with continuous stirring and mixing, the precursor could be obtained after being filtered, washed, and dried at 80 degrees C. The Nd2O3 Sample was obtained via calcination of the precursor at 700 degrees C for 1.5 h. The morphology, size and distribution of the precursors and samples were characterized by TG-DTA, XRD, TEM, HR-TEM, SAED and BET techniques. The forming mechanism of homogenous precipitation was discussed detailedly. The results indicated that the Nd2O3 nanocrystal prepared with the present method belonged to hexagonal crystal system, and its average diameter was 26-32 nm with better decentralization. The electron diffraction pattern which had a clear and regular lattice of Nd2O3 confirmed that the particles were monocrystals. The specific surface area of sample a and sample b was 42. 57 and 29.43 m2 x g(-1), respectively. The ion exchange resin homogenous precipitation method has such advantages as low cost, environmentally benign innocuity of the starting reagents, the simplicity of the synthetic route, easy recycling of ion exchange resin and so on, making it a promising method to be scaled up for industrial production.