Various configuration types of the foveal avascular zone with related factors in normal Chinese adults with or without myopia assessed by swept-source OCT angiography.

AIM: To describe the morphological characteristics of foveal avascular zone (FAZ) in normal Chinese adults with or without myopia by swept-source optical coherence tomography angiography (SS-OCTA) and analyze the possible associated factors. METHODS: Normal Chinese adults with or without myopia aged between 18 and 60y were recruited into the study. One eye in each individual was randomly selected for scanning using SS-OCTA. FAZ parameters, central retinal thickness (CRT) and central choroidal thickness (CCT) were then analyzed. Correlations between systemic and ocular variables and FAZ parameters were subsequently evaluated. The subgroup analysis based on refractive error was also carried out. RESULTS: In total, 127 eyes out of 127 normal subjects were finally included in the study (mean age 29.5±8.22y, 61 males and 66 females). The pattern of FAZ was variable: round configuration in 28 eyes (22%), quadrilateral configuration in 23 eyes (18%), pentagonal configuration in 20 eyes (16%), oval configuration in 15 eyes (12%), triangular configuration in 6 eyes (5%) and irregular configuration in 35 eyes (28%). The mean area of FAZ was 0.37±0.12 mm2. Females had a larger FAZ (0.41±0.11 mm2 vs 0.32±0.11 mm2) compared with that of males (P<0.01). All myopic individuals showed smaller FAZ area and perimeter compared with that of normal individuals (P<0.01). There was no obvious correlation between age and FAZ. In the univariate regression analysis, both axial length (AL) and refractive error were significantly related to FAZ parameters. However, only CRT showed negative correlation with FAZ in the multivariate regression analysis. CONCLUSION: The pattern of FAZ configuration in normal Chinese adults with or without myopia is highly variable. Establishing quantitative parameters of FAZ would not only provide details of macular pathophysiology but could possibly contribute as a biomarker in disease staging.

[Plant species diversity of Carex peat mire in Changbai Mountains, China]. / é•¿ç™½å±±åŒºè‹”è‰æ³¥ç‚­æ²¼æ³½æ¤ç‰©ç‰©ç§å¤šæ ·æ€§.

We investigated the plant species richness both in cespitose Carex mires (C. schmidtii, C. meyeriana) and non-cespitose Carex mire (C. lasiocarpa) in Changbai Mountain. A total of 83 species (36 families, 59 genuses) was recorded in three sites. Among which, 71 species occurred in the C. meyeriana site, 61 species in the C. schmidtii site, and 26 species in the C. lasiocarpa site. The total species number and species richness in the two cespitose Carex mires were much higher than that in the non-cespitose Carex mire, while those on tussocks were much higher than between tussocks in the two cespitose Carex mires. Plant species richness on tussocks was positively related to the height, basal circumference and surface area of the tussocks, suggesting that tussocks were important for plant species diversity in Carex mires. Results of the canonical correspondence analysis indicated that the differences in soil water content, nutrient (soil organic carbon, total N, total P and C/N), and litter layer depth were the main factors influencing the differences of plant community composition on tussocks and between-tussocks. In the cespitose Carex mires, the hummock-hollow microtopography could foster high diversity by increasing surface area and creating multiple micro-habitats. Given its function in maintaining high species diversity, cespitose Carex could be a preferred species for vegetation restoration in degraded peat mires.

Study of retinal vessel oxygen saturation in ischemic and non-ischemic branch retinal vein occlusion.

AIM: To explore how oxygen saturation in retinal blood vessels is altered in ischemic and non-ischemic branch retinal vein occlusion (BRVO). METHODS: Fifty BRVO eyes were divided into ischemic (n=26) and non-ischemic (n=24) groups, based on fundus fluorescein angiography. Healthy individuals (n=52 and n=48, respectively) were also recruited as controls for the two groups. The mean oxygen saturations of the occluded vessels and central vessels were measured by oximetry in the BRVO and control groups. RESULTS: In the ischemic BRVO group, the occluded arterioles oxygen saturation (SaO2-A, 106.0%±14.3%), instead of the occluded venule oxygen saturation (SaO2-V, 60.8%±9.4%), showed increases when compared with those in the same quadrant vessels (SaO2-A, 86.1%±16.5%) in the contralateral eyes (P<0.05). The oxygen saturations of the central vessels showed similar trends with those of the occluded vessels. In the non-ischemic BRVO group, the occluded and central SaO2-V and SaO2-A showed no significant changes. In both the ischemic and non-ischemic BRVOs, the central SaO2-A was significantly increased when compared to healthy individuals. CONCLUSION: Obvious changes in the occluded and central SaO2-A were found in the ischemic BRVO group, indicating that disorders of oxygen metabolism in the arterioles may participate in the pathogenesis of ischemic BRVO.

[Influence of LDAO on the conformation and release of bacteriochlorophyll of peripheral light-harvesting complex (LH2) from Rhodobacter azotoformans].

The aim of this study is to reveal the interaction relationships between lauryl dimethylamine N-oxide (LDAO) and peripheral light-harvesting complex (LH2) as well as the influence of LDAO on structure and function of LH2. In the present work, the effects of LDAO on the conformation and release processes of bacteriochlorophyll (BChl) of LH2 when incubated under different temperature and pH in the presence and absence of LDAO were investigated by spectroscopy. The results indicated that (1) the presence of LDAO resulted in alterations in the conformation, alpha-helix content, and spectra of Tyr and B850 band of LH2 at room temperature and pH 8.0. Moreover, energy transfer efficiency of LH2 was enhanced markedly in the presence of LDAO. (2) At 60 degrees C, both the B800 and B850 band of LH2 were released and transited into free BChl at pH 8.0. However, the release rates of bacteriochlorophylls of B800 and B850 band from LH2 were slowed down and the release processes were changed when incubated in the presence of LDAO. Hence, the stability of LH2 was improved in the presence of LDAO. (3) The accelerated release processes of bacteriochlorophylls of B800 and B850 band of LH2 were induced to transform into bacteriopheophytin (BPhe) and free BChl by LDAO in strong acid and strong alkalic solution at room temperature. However, the kinetic patterns of the B800 and B850 band were remarkably different. The release and self-assemble processes of B850 in LH2 were observed in strong acid solution without LDAO. Therefore, the different release behaviors of B800 and B850 of LH2 are induced by LDAO under different extreme environmental conditions.

[Function of pancreatic islet beta cells and features of TCM symptoms and syndromes in the non-diabetic first-grade relatives of patients with type 2 diabetes mellitus].

OBJECTIVE: To study the function of pancreatic islet beta cells, insulin resistance (IR) and features of TCM symptoms and syndromes in the non-diabetic first-grade relatives (ND1GR) of patients with type 2 diabetes mellitus (DM2). METHODS: A total of 68 ND1GR of DM2 patients were enrolled in the observed group and 45 healthy subjects with matched sex, age and body mass index (BMI) but without family history of DM were selected into the control group. Levels of fasting blood glucose (FBG), 2 hrs postprandial glucose (2hPG), fasting insulin (FINS) and 2 hrs postprandial insulin (2h INS) in all the subjects were measured to calculate and compare the IR and beta-cell function of the homeostatic model analog (HOMA-IR and HOMA-beta), and the insulin sensitive index (ISI). Moreover, the symptoms manifested in the ND1GR were also observed to analyze the features in them. RESULTS: FBG and FINS were obviously higher in the observed group than those in the control group (P < 0.01), while no significant difference was found in 2hPG or 2h INS (P > 0.05). HOMA-IR and HOMA-beta were significantly higher (P < 0.05) and ISI were significantly lower (P < 0.01) in the observed group than those in the control group. Compared with the control group, the main symptoms such as dark purplish tongue, listlessness, thready and thin pulse, lassitude in loin and legs in the observed group were seen more frequently. In the observed group syndrome of deficiency of Qi and Yin accounted for 51.47%, syndrome of deficiency of Yin for 30.88%, subjects with syndrome of blood stasis as the main accompanying syndrome accounts for 61.76%. CONCLUSION: Higher beta cell secretion function and lower insulin sensitivity appear in ND1GR of DM2 patients, suggesting the existence of insulin resistance. The feature of TCM syndrome in them is characterized by deficiency of Qi and Yin with inner obstruction of blood stasis.