Renal water molecular diffusion characteristics in healthy native kidneys: assessment with diffusion tensor MR imaging.

BACKGROUND: To explore the characteristics of diffusion tensor imaging (DTI) and magnetic resonance (MR) imaging in healthy native kidneys. METHODS: Seventy-three patients without chronic kidney disease underwent DTI-MRI with spin echo-echo planar (SE-EPI) sequences accompanied by an array spatial sensitivity encoding technique (ASSET). Cortical and medullary mean, axial and radial diffusivity (MD, AD and RD), fractional anisotropy (FA) and primary, secondary and tertiary eigenvalues (λ1, λ2, λ3) were analysed in both kidneys and in different genders. RESULTS: Cortical MD, λ2, λ3, and RD values were higher than corresponding medullary values. The cortical FA value was lower than the medullary FA value. Medullary λ1 and RD values in the left kidney were lower than in the right kidney. Medullary λ2, and λ3 values in women were higher than those in men. Medullary FA values in women were lower than those in men. Medullary FA (r = 0.351, P = 0.002) and λ1 (r = 0.277, P = 0.018) positively correlated with eGFR. Medullary FA (r = -0.25, P = 0.033) negatively correlated with age. CONCLUSIONS: Renal water molecular diffusion differences exist in human kidneys and genders. Age and eGFR correlate with medullary FA and primary eigenvalue

Physiological, biochemical and phytohormone responses of Elymus nutans to α-pinene-induced allelopathy

The α-pinene is the main allelochemical of many weeds that inhibit the growth of Elymus nutans, an important forage and ecological restoration herbage. However, the response changes of α-pinene-induced allelopathy to E. nutans is still unclear. Here, we investigated the physiological, biochemical and phytohormone changes of E. nutans exposed to different α-pinene concentrations. The α-pinene-stress had no significant effect on height and fresh weight (FW) of seedlings. The water-soluble proteins, the soluble sugars and proline (Pro) strengthened seedlings immunity at 5 and 10 µL L−1 α-pinene. Superoxide dismutase (SOD) and ascorbate peroxidase (APX) increased at 5 µL L−1 α-pinene to resist stress. APX reduced the membrane lipid peroxidation quickly at 10 µL L−1 α-pinene. The high-activity of peroxidase (POD), APX along with the high level of GSH contributed to the cellular redox equilibrium at 15 µL L−1 α-pinene. The POD, glutathione reductase (GR) activity and glutathione (GSH) level remained stable at 20 µL L−1 α-pinene. The changes in antioxidant enzymes and antioxidants indicated that E. nutans was effective in counteracting the harmful effects generated by hydrogen peroxide (H2O2). The α-pinene caused severe phytotoxic effects in E. nutans seedlings at 15 and 20 µL L−1. Endogenous signal nitric oxide (NO) and cell membrane damage product Pro accumulated in leaves of E. nutans seedlings at 15 and 20 µL L−1 α-pinene, while lipid peroxidation product malondialdehyde (MDA) accumulated. The chlorophylls (Chls), chlorophyll a (Chl a), chlorophyll b (Chl b) content decreased, and biomass of seedlings was severely inhibited at 20 µL L−1 α-pinene. The α-pinene caused phytotoxic effects on E. nutans seedlings mainly through breaking the balance of the membrane system rather than with reactive oxygen species (ROS) productionat 15 and 20 µL L−1 α-pinene. Additionally, phytohormone levels were altered by α-pinene-stress. Abscisic acid (ABA) and indole acetic acid (IAA) of E. nutans seedlings were sensitive to α-pinene. As for the degree of α-pinene stress, salicylic acid (SA) and jasmonic acid (JA) played an important role in resisting allelopathic effects at 15 µL L−1 α-pinene. The ABA, Zeatin, SA, gibberellin 7 (GA7), JA and IAA levels increased at 20 µL L−1 α-pinene. The α-pinene had a greatest impact on ABA and IAA levels. Collectively, our results suggest that E. nutans seedlings were effective in counteracting the harmful effects at 5 and 10 µL L−1 α-pinene, and they were severely stressed at 15 and 20 µL L−1 α-pinene. Our findings provided references for understanding the allelopathic mechanism about allelochemicals to plants

Niche analysis of dominant species in alpine desert grassland communities in Qaidam Basin

Community dominant plants and their ecological niche research is the focus of community ecology research. To explore the niche characteristics of desert dominant plants and the relationship between them and soil factors in Qaidam Basin, and to provide a basis for the construction of desert plant communities and the sustainable management of natural resources in Qaidam Basin. Taking 13 desert plant communities in Qaidam Basin, Qinghai Province as the research objects, this paper analyzed the characteristics of desert plant communities and dominant species based on soil physical and chemical properties, and calculated the niche width and niche overlap of dominant plants. The dominant plants are, Haloxylon ammodendron, Tamarix chinensis, Achnatherum splendens, Poacynum hendersonii, Reaumuria songonica, Phragmites australiss, Sympegma regelii, and Ajania Tenuifolia, Artemisia sphaerocephala, Ceratoides latens, Pearl russianthistle, Scirpustriquter. There were different degree of niche overlap among species in the community. In addition, CCA sequencing showed that different species had different requirements on the environment, and the distribution of dominant species was mainly affected by soil total nitrogen and soil organic matter

Biosynthesis pathway related production of medium chain length polyhydroxyalkanoates

Pseudomonas flava   HBE06 isolated from oil-contaminated soil was found to produce polyesters consisting of medium chain length polyhydroxyalkanoates (mcl PHA). The strain mainly synthesized PHA containing 3-hydroxyoctanoate (C8 or HO), 3-hydroxynonanoate (C9 or HN), 3-hydroxydecanoate (C10 or HD), and 3-hydroxyunidecanoate (C11 or HUD) as monomers when grown on various substrates. It was found that the monomer ratio (especially C10 /C8 or C11 /C9) was related to the PHA biosynthesis pathway. When PHA was synthesized via the de novo fatty acid pathway, the molar ratio of C10 /C8was greater than 2. If PHA was synthesized from β-oxidation of fatty acids, C10 /C8was less than 1. Pseudomonas stutzeri   1317 is another mcl PHA synthesizing bacteria whose C10 /C8 ratio is also related to the synthesis pathway. When the two synthesis pathways were used together, the C10 /C8 ratio could be adjusted according to the ratio of the mixed substrates

Anatomic and DTI-MRI map of native healthy kidneys.

<p>(A) T₁INPHASE fat-suppression background reference map; (B) DTI tractographic map; (C) DTI MD pseudo-color map; (D) DTI FA pseudo-color map.</p

Factor analysis of physiological and DTI indices.

<p>Factor analysis of physiological and DTI indices.</p

Variance by principal component and rotational sum.

<p>Variance by principal component and rotational sum.</p

DTI parameter index value by gender.

<p>Footnote: KMO, Kaiser-Meyer-Olkin measure of sampling adequacy;</p><p>Bartlett’s, Bartlett’s test of sphericity.</p><p>physiological items including: age, gender, height, weight, BMI, BSA, eGFR.</p><p>DTI items including: MD, FA, λ₁, λ₂, λ₃, RD.</p><p>DTI parameter index value by gender.</p

Evaluation of Heavy Metal Level in Soil of Typical Alpine Grassland Communities

Objective: Through the investigation, determination and analysis of heavy metals in the soil of typical alpine grassland community, five kinds of alpine grasslands with different degeneration degree of Maduo County in Alpine area, two kinds of alpine grassland with high Maqu County, high Alpine desert along the coast of Qinghai Lake, alpine thickets in the yellow South region, Alpine wetlands, The condition of soil heavy metals in alpine meadow and other communities is analyzed, which provides scientific guidance for the ecological protection measures of typical alpine grassland communities, and provides a basis for the sustainable utilization of Alpine grassland. Methods: The content of various kinds of heavy metals in soil samples was determined by ICP-MS, and the pollution status of heavy metals was analyzed by means of single factor pollution index method, Nemero comprehensive pollution index method and potential ecological risk index method by using Excel. Results: (1) The content of Cd in Maduo, Maqu, Qinghai Lake and Huangnan was 1.74, 0.97, 1.84 and 1.06 times times the soil environment background respectively, and the content of Hg in Maqu was 1.36 times times that of soil environmental background value. The variation coefficient of Hg and Pb in Maqu and the coefficient of variation of Cd in Qinghai Lake are more than 100%, which is in the degree of high variation, which is greatly influenced by man. (2) The highest total pollution index in the 4 sample places was in the area of MA diversity, at 1.33. The second is the Huangnan sample, with an exponential value of 0.86. The Nemero comprehensive pollution Index of the Maqu sample is 0.77. The index value of Qinghai Lake sample is the lowest, at 0.61. (3) The highest potential ecological hazard index is the most diverse, in 0-10, 10-20, 20-30cm three soil layers are 96.96, 103.58, 102.46, Maqu in 0-10, 10-20cm soil, the potential ecological hazard index is 65.70, 71.01, the potential ecological hazard index of Huangnan in three soil layer is 78.23, 73.42 and 72.84 respectively, which refers to the smallest value of Qinghai Lake sample, three, 51.07 and 51.72 in 51.48 soil layer respectively. Conclusion: The Nemero comprehensive pollution Index of Qinghai Lake sample is less than 0.7, at the level of cleanliness, the exponential value of Huangnan and Maqu two samples is between 0.7~1, at the level of cordon, and the exponential value of ma variety is between 1~2, at the level of mild pollution. The comprehensive potential ecological hazard index of 80~160 has the potential ecological risk of strength, and the exponential value of the other three samples is between 40~80, which has medium potential ecological risk. Generally, the pollution degree of heavy metals is small in the whole alpine grassland area