Corneal thickness (CT) maps of the central (2-mm diameter), para-central (2 to 5-mm diameter), peripheral (5 to 6-mm diameter), and minimum (5-mm diameter) cornea were measured in normal Chinese ...school children aged 7 to 15 years old using Fourier-domain optical coherence tomography. Multiple regression analyses were performed to explore the effect of associated factors age, gender, refraction, axial length and corneal curvature radius (CCR) on CT and the relationship between central corneal thickness (CCT) and intraocular pressure (IOP). A total of 1228 eyes from 614 children were analyzed. The average CCT was 532.96 ± 28.33 μm for right eyes and 532.70 ±28.45 μm for left eyes. With a 10 μm increase in CCT, the IOP was elevated by 0.37 mm Hg, as measured by noncontact tonometry. The CT increased gradually from the center to the periphery. The superior and superior nasal regions had the thickest CTs, while the thinnest points were primarily located in the inferior temporal cornea. The CCT was associated with CCR (p = 0.008) but not with gender (p = 0.075), age (p = 0.286), axial length (p = 0.405), or refraction (p = 0.985). In the para-central region and the peripheral cornea, increased CT was associated with younger age, male gender, and a flatter cornea.
To calculate crystalline lens power and to determine the relationship between ocular biometry and diabetic retinopathy (DR) in an adult population with type 2 diabetes mellitus (T2DM).
...Cross-sectional, population-based study.
Patients with T2DM from the Beixinjing community, Changning district, Shanghai.
Random clustering sampling was used to identify adults with T2DM in the Beixinjing community. Spherical equivalent (SE) was determined by subjective refraction that achieved the best corrected vision. Axial length (AL), corneal power (CP), and anterior chamber depth (ACD) were measured using the IOLMaster. Diabetic retinopathy and diabetic macular edema (DME) were assessed according to the international DR classification.
The crystalline lens power was calculated using the Bennett-Rabbetts formula. The AL-to-corneal radius ratio (AL/CR ratio) was defined as the axial length divided by the mean corneal radius of curvature.
A total of 4011 eyes of 2057 subjects with T2DM were included in the analysis. In multivariate logistic models adjusting for age, sex, duration of diabetes, glycosylated hemoglobin A1c, serum creatinine, body mass index, systolic blood pressure, and cataract, after categorizing values into quartiles, there were trend associations between lens power and any DR (P = 0.01), between AL/CR ratio and any DR (P = 0.02), and between AL and any DR (P = 0.03), between lens power and moderate DR (P = 0.02), and between AL and moderate DR (P = 0.02); eyes with higher AL/CR ratio were less likely to have any DR (odds ratio OR, 0.43; 95% confidence interval CI, 0.24-0.78; P = 0.01 per 1 increase) and moderate DR (OR, 0.44; 95% CI, 0.21-0.93; P = 0.03 per 1 increase), eyes with longer AL were less likely to have any DR (OR, 0.88; 95% CI, 0.81-0.95; P = 0.002 per millimeter increase) or moderate DR (OR, 0.89; 95% CI, 0.80-0.98; P = 0.02 per millimeter increase), and eyes with higher SE were more likely to have any DR (OR, 1.08; 95% CI, 1.03-1.13; P = 0.003 per diopter increase).
In persons with T2DM, lens power, AL/CR ratio, and AL were associated with the presence of any DR and moderate DR. These findings suggested that globe elongation plays a major role in protective effects against DR, with contributions from lens power and other refractive components.
To determine the relationship between choroidal thickness (ChT) at the posterior pole and refractive error and to explore the difference between the macular and peripapillary regions in children with ...myopia.
A total of 340 healthy Chinese children underwent a series of comprehensive ocular examinations including cycloplegic refraction. Swept-source optical coherence tomography was used to measure the ChT in the macular and peripapillary regions. The Early Treatment of Diabetic Retinopathy Study grid was applied to define the sectors.
The mean spherical equivalent (SE) of the participants was -1.71 ± 2.22 diopter (D; range from -7.63 to 4.25 D). The mean ChT in the central foveal, parafoveal, and perifoveal regions were 229 ± 65 μm, 227 ± 60 μm, and 215 ± 50 μm, respectively, and the mean global peripapillary choroidal thickness (PPCT) was 136 ± 33 μm. The choroid in the macular region and the global PPCT was thinner in myopes compared to hyperopes. The area between the central fovea and the optic disc underwent the largest change as myopia worsened. SE, uncorrected visual acuity, cornea curvature radius (CR), retinal thickness (RT), and retinal nerve fiber layer thickness (RNFLT, except for the central fovea) were the independent factors of ChT in the macular region. SE, CR, RT, and RNFLT were the independent factors of PPCT temporally, inferiorly, and globally, while only CR, RT, and RNFLT were independently associated with PPCT superiorly and nasally.
Choroidal thinning might be uneven during the development of myopia. SE only influenced the macular area and sectors temporal and inferior to the optic disc.
Purpose
To explore the subfoveal thickness of sclera (SST), choroid (SCT) and retina (SRT) as well as their relationship in healthy Chinese children with varying levels of refractive error.
Methods
A ...total of 810 healthy Chinese schoolchildren and adolescents underwent a series of comprehensive ocular examinations, as well as swept‐source optical coherence tomography (OCT) after induced cycloplegia. The thicknesses of the sclera, choroid and retina below the central fovea were measured manually, and each measurement was compared across different refractive statuses. Independent factors associated with the thickness of each layer were analysed.
Results
The mean SST, SCT and SRT were 524 ± 57 μm, 195 ± 49 μm and 224 ± 19 μm, respectively. The SSTs and SCTs of myopes were significantly thinner than those of emmetropes and hyperopes (all p < 0.001). Although the choroid seemed to be thicker in hyperopes (225 ± 46 μm) than in emmetropes (211 ± 45 μm), no statistically significant difference was observed between emmetropes and hyperopes in the sclera and choroid. Thinner SSTs and SCTs were associated with greater levels of myopia, whereas the SRT was similar in children with different myopic levels. SST (p < 0.001) and SCT (p = 0.003) as well as age (p < 0.001), sex (p < 0.001) and axial length (p < 0.001) were independently associated with spherical equivalent refraction (SER). Older age (p = 0.013), myopic‐shifted SER (p < 0.001), thicker SCT (p < 0.001) and thinner SRT (p = 0.012) were independently associated with a thinner SST.
Conclusion
The subfoveal sclera and choroid were thinner in myopes than in emmetropes and hyperopes, while the retina remains constant. Age, refractive error and choroidal and retinal thicknesses are related to subfoveal scleral thickness.
The species-specific responses of plant growth to elevated atmospheric CO2 concentration (eCO2) could lead to N limitation and potentially influence the sustainability of ecosystem. Questions remain ...unanswered with regards to the response of soil N2-fixing community to eCO2 when developing high-yielding agroecosystem to dampen the future rate of increase in CO2 levels and associated climate warming. This study demonstrates the divergent eCO2 influences on the paddy diazotrophic community between weak- and strong-responsive rice cultivars. In response to eCO2, the diazotrophic abundance increased more for the strong-responsive cultivar treatments than for the weak-responsive ones. Only the strong-responsive cultivars decreased the alpha diversity and separated the composition of diazotrophic communities in response to eCO2. The topological indices of the ecological networks further highlighted the different co-occurrence patterns of the diazotrophic microbiome in rice cultivars under eCO2. Strong-responsive cultivars destabilized the diazotrophic community by complicating and centralizing the co-occurrence network as well as by shifting the hub species from Bradyrhizobium to Dechloromonas in response to eCO2. On the contrary, the network pattern of the weak-responsive cultivars was simplified and decentralized in response to eCO2, with the hub species shifting from Halorhodospira under aCO2 to Sideroxydans under eCO2. Collectively, the above information indicates that the strong-responsive cultivars could potentially undermine the belowground ecosystem from the diazotrophs perspective in response to eCO2. This information highlights that more attention should be paid to the stability of the belowground ecosystem when developing agricultural strategies to adapt prospective climatic scenarios by growing high-yielding crop cultivars under eCO2.
AimsTo elucidate the influence of age and myopic shift on retinal development.MethodsThis 1-year longitudinal study included 769 participants aged 6–17 years. Cycloplegic refraction, axial length and ...swept-source optical coherence tomography were examined at baseline and follow-up. The thickness changes in the retina, ganglion cell complex (GCC) and outer retinal layers (ORL) in the macular region were calculated, and their relation with age and myopic shift was analysed with multiple linear regression analysis.ResultsThe thickness of the central foveal retinal layers was increased in children (<10 years) but unchanged or decreased in adolescents (>13 years). The thickness changes in the retina, GCC and ORL decreased with age (r=−0.24,–0.23, −0.15, respectively, all p<0.01). Multiple regression analysis showed that the changes in central foveal retinal thickness (RT) and GCC thickness were independently associated with age and baseline spherical equivalent (SE), while the changes in ORL thickness were associated with age and SE changes. In children 8–9 years, a greater increase was observed in central foveal ORL thickness in those with no myopic shift (p<0.01). The thickness of the most parafoveal and perifoveal retinal layers was less increased or more decreased in children <9 years with myopic shift (p<0.05).ConclusionsRetinal development and its relation with myopic shift varies from childhood to adolescence. Myopia-related retinal thinning may result from less increase in the RT in childhood rather than a decrease in RT in adolescents. Children under 9 years old could be at a critical age for future myopia-related retinal thinning.
Caerulomycins are a family of natural alkaloids featuring a 2,2′-bipyridine nucleus. Since the first example of caerulomycins, caerulomycin A from Streptomyces caeruleus, was reported in 1959, there ...have been 34 natural caerulomycins from microorganisms reported. The unique structure of caerulomycins and their potential bioactivity, including antifungal activity, cytotoxicity, and immunosuppression, have attracted the interest of both chemists and biologists. Herein, we report 8 new caerulomycins (19–22 and 39–42) as well as 14 known analogues (1–3, 6–9, 16, 18, 24, 25, 27, 29, and 31) from wild-type and mutant Actinoalloteichus cyanogriseus WH1-2216-6. The structures including the absolute configurations were unambiguously elucidated by spectroscopic analysis, X-ray single crystal diffraction, 1-phenyl-3-methyl-5-pyrazolone (PMP)-labeling HPLC analysis, Mosher's method and quantum electronic circular dichroism (ECD) calculation. The cytotoxicity of caerulomycins 1–42 and some previously reported analogues was assayed against six human tumor cell lines and a human normal liver cell line, L-02. Compounds 1, 2, 5, 13, 18, 27, and 39 exhibited moderate to strong cytotoxicity against the tumor cells with IC50 values ranging from 0.1 to 50 μM. The structure and activity relationships (SARs) are also discussed. In addition, the caerulomycin glycosides (29, 34, and 39) showed effective selectivity against HCT-116 cells with low toxicity toward the normal L-02 cell line, indicating their potential use as lead compounds for antitumor drugs.
Microbial communities, coupled with substrate quality and availability, regulate the stock (formation versus mineralization) of soil organic matter (SOM) in terrestrial ecosystems. However, our ...understanding of how soil microbes interact with contrasting substrates influencing SOM quantity and quality is still very superficial. Here, we used thermodynamic theory principles and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) to evaluate the linkages between dissolved organic matter (DOM organic substrates in soil that are readily available), thermodynamic quality, and microbial communities. We investigated soils from subtropical paddy ecosystems across a 1,000-km gradient and comprising contrasting levels of SOM content and nutrient availability. Our region-scale study suggested that soils with a larger abundance of readily accessible resources (i.e., lower Gibbs free energy) supported higher levels of microbial diversity and higher SOM content. We further advocated a novel phylotype-level microbial classification based on their associations with OM quantities and qualities and identified two contrasting clusters of bacterial taxa: phylotypes that are highly positively correlated with thermodynamically favorable DOM and larger SOM content versus those which are associated with less-favorable DOM and lower SOM content. Both groups are expected to play critical roles in regulating SOM contents in the soil. By identifying the associations between microbial phylotypes of different life strategies and OM qualities and quantities, our study indicates that thermodynamic theory can act as a proxy for the relationship between OM and soil microbial communities and should be considered in models of soil organic matter preservation.
Microbial communities are known to be important drivers of organic matter (OM) accumulation in terrestrial ecosystems. However, despite the importance of these soil microbes and processes, the mechanisms behind these microbial-SOM associations remain poorly understood. Here, we used the principles of thermodynamic theory and novel Fourier transform ion cyclotron resonance mass spectrometry techniques to investigate the links between microbial communities and dissolved OM (DOM) thermodynamic quality in soils across a 1,000-km gradient and comprising contrasting nutrient and C contents. Our region-scale study provided evidence that soils with a larger amount of readily accessible resources (i.e., lower Gibbs free energy) supported higher levels of microbial diversity and larger SOM content. Moreover, we created a novel phylotype-level microbial classification based on the associations between microbial taxa and DOM quantities and qualities. We found two contrasting clusters of bacterial taxa based on their level of association with thermodynamically favorable DOM and SOM content. Our study advances our knowledge on the important links between microbial communities and SOM. Moreover, by identifying the associations between microbial phylotypes of different life strategies and OM qualities and quantities, our study indicates that thermodynamic theory can act as a proxy for the relationship between OM and soil microbial communities. Together, our findings support that the association between microbial species taxa and substrate thermodynamic quality constituted an important complement explanation for soil organic matter preservation.
Plant endophytic bacteria play an important role in plant growth and health. In the context of climate change, the response of plant endophytic bacterial communities to elevated CO2 at different rice ...growing stages is poorly understood. Using 454 pyrosequencing, we investigated the response of leaf endophytic bacterial communities to elevated CO2 (eCO2) at the tillering, filling, and maturity stages of the rice plant under different nitrogen fertilization conditions low nitrogen fertilization (LN) and high nitrogen fertilization (HN). The results revealed that the leaf endophytic bacterial community was dominated by Gammaproteobacteria-affiliated families, such as Enterobacteriaceae and Xanthomonadaceae, which represent 28.7-86.8% and 2.14-42.6% of the total sequence reads, respectively, at all tested growth stages. The difference in the bacterial community structure between the different growth stages was greater than the difference resulting from the CO2 and nitrogen fertilization treatments. The eCO2 effect on the bacterial communities differed greatly under different nitrogen application conditions and at different growth stages. Specifically, eCO2 revealed a significant effect on the community structure under both LN and HN levels at the tillering stage; however, the significant effect of eCO2 was only observed under HN, rather than under the LN condition at the filling stage; no significant effect of eCO2 on the community structure at both the LN and HN fertilization levels was found at the maturity stage. These results provide useful insights into the response of leaf endophytic bacterial communities to elevated CO2 across rice growth stages.
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