ABSTRACT
Exopolysaccharides (EPS), an important substance of cyanobacteria in resisting stresses, are the main form of carbon storage in biocrusts and play an important role in material cycling and stability of biocrusts. In this study, the biocrusts in different seasons (January, April, July, October) were collected from Gurbantunggut Desert, and the dynamics of EPS content, composition, morphological characteristics and microbial community structures were analyzed. The results showed that: 1) The excretion of EPS showed obvious seasonal dynamics. The EPS contents in January, April, July and October were 81.72, 52.46, 76.77, 70.54 µg·cm-2, and the chlorophyll a contents were 2.7, 4.94, 4.2 and 5.98 µg·cm-2, respectively. Cyanobacteria allocated more fixed organic carbon to EPS in winter and summer, and more to their own biomass accumulation in spring and autumn. 2) EPS in biocrusts of each season was composed of seven kinds of monosaccharides. The sum of relative mole percentages of glucose and galactose was 46%-56%, much higher than the other five monosaccharides. The monosaccharide compositions of EPS were significantly affected by temperature and precipitation. There was no significant difference in the Fourier infrared spectra of EPS in biocrusts across different seasons. 3) The observation results of atomic force microscope showed that more filamentous and thick rope-like structures occurred in EPS in July and October, while the EPS showed block-like morphology in January and April. 4) The results of 16S rDNA high-throughput sequencing showed that Cyanobacteria and Microcoleus were the dominant bacterial phyla and genus in biocrusts in all the four seasons, with significantly higher relative abundance than other bacterial phyla and genera. The relative abundance of Proteobacteria was significantly positively correlated with the relative mole percentages of fucose and galactose, indicating that the composition of monosaccharides affected heterotrophic bacteria in crusts. In deserts, environmental factors such as temperature and moisture changed significantly across seasons. The physicochemical properties of biocrust exopolysaccharides and the seasonal dynamics of bacterial communities were controlled by multiple factors, such as temperature, moisture, and light.
Subject(s)
Cyanobacteria , Microbiota , Carbon , Chlorophyll A , Desert Climate , Galactose , Seasons , Soil/chemistry , Soil MicrobiologyABSTRACT
Objective To analyze the related factors regarding diabetic nephropathy (DN).Methods A total number of 756 diabetic patients from 2009 to 2011 were analyzed retrospectively.Three groups were formed according to the urinary albumin excretion rates (UAER).Patients with UAER＜20 μg/min was grouped to group A,with UAER from 20 to 200 μg/min as group B,and the others with UAER ≥200 μg/min was grouped to group C.General characteristics and laboratory parameters were then compared and related factors of DN analyzed.Results The constituent ratio of nephropathy was 30.2％ (228/756).Patient's age,duration of disease,both diastolic and systolic blood pressure of group A were significantly higher than the non-DN group (A) (P＜0.05).Patient's age,disease duration,both diastolic and systolic blood pressure of group C were (64.08± 11.71)years,(14.67± 7.34)years,(87.43 ± 14.36)mm Hg,(152.45 ± 18.48)mm Hg,respectively,with statistically significant difference (P＜0.05) between group C and group B.FPG,TG,TC,HDL-C,UA,HbAlc,FINS,FCP of group B were (9.27 ± 3.06) mmol/L,(1.98 ± 0.37) mmol/L,(5.01 ± 1.08) mmol/L,(1.05 ± 0.35) mmol/L,(312.78 ± 39.83) mmol/L,(9.33 ± 1.47)％,(11.45 ± 7.83) μU/ml,(509.73 ±132.78) pmol/L respectively,with significant difference (P＜0.05) between group B and group A.FPG,TG,HDL-C,UA,FINS,FCP of group C were (9.29 ± 3.12)mmol/L,(2.02 ± 0.36)mmol/L,(1.04 ± 0.27) mmol/L,(389.72 ± 46.32) mmol/L,(11.09 ± 8.29) μ U/ml,(575.77 ± 143.29) pmol/Lrespectively,with significant difference (P＜0.05) between group C and group A.UA,FINS,FCP were found with significant differences (P＜0.05) between group C and group B.Data from multivariate logistic regression showed that DNs were related with disease duration,BMI,systolic blood pressure,HbAlc,FPG,UA.Conclusion DN was closely related to the duration,age,blood sugar,blood lipids,blood pressure,uric acid levels of the disease.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the basis of distinctive function of acupoint through observing the effects of acupuncture at the areas of acupoint and non-acupoint on functional connectivity of different brain regions.</p><p><b>METHODS</b>Twenty-one healthy volunteers were randomly divided into two groups: 12 cases in the acupoint group and 9 cases in the non-acupoints group. Bilateral Zusanli (ST 36) and its lateral 3-4 mm were punctured with twirling manipulation in the acupoint group and the non-acupoints group respectively. Before and after 25 minutes treatment, data of functional magnetic resonance imaging (fMRI) scanning was taken from bilateral cingulate gyrus (seed point) to analyze the functional connectivity in both groups.</p><p><b>RESULTS</b>Brain functional connectivity was demonstrated widely in both acupoint group and non-acupoint group after acupuncture. Comparing with the non-acupoint group, in the acupoint group, brain functional connectivity with posterior cingulate gyrus was found more intensively in the bilateral tonsil, right dentate nucleus, bilateral uvula, left declive and right tuber of cerebellum, as well as in the left inferior frontal gyrus, right middle temporal gyurs, bilateral paracentral lobule, left cingulate cortex, right superior temporal gyrus, right anterior cingulate gyrus etc., however, its connectivity was less in the bilateral medial frontal gyrus and right inferior frontal gyrus.</p><p><b>CONCLUSION</b>Both acupoint and non-acupoint can evoke brain functional connectivity that is similar on the most of regions, but the intensity of this connectivity in the acupoint group is higher than that in the non-acupoint group.</p>
