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The size and shape of the foveal avascular zone (FAZ) have a strong positive correlation with several vision-threatening retinovascular diseases. The identification, segmentation and analysis of FAZ are of great significance to clinical diagnosis and treatment. We presented an adaptive watershed algorithm to automatically extract FAZ from retinal optical coherence tomography angiography (OCTA) images. For the traditional watershed algorithm, “over-segmentation” is the most common problem. FAZ is often incorrectly divided into multiple regions by redundant “dams”. This paper analyzed the relationship between the “dams” length and the maximum inscribed circle radius of FAZ, and proposed an adaptive watershed algorithm to solve the problem of “over-segmentation”. Here, 132 healthy retinal images and 50 diabetic retinopathy (DR) images were used to verify the accuracy and stability of the algorithm. Three ophthalmologists were invited to make quantitative and qualitative evaluations on the segmentation results of this algorithm. The quantitative evaluation results show that the correlation coefficients between the automatic and manual segmentation results are 0.945 (in healthy subjects) and 0.927 (in DR patients), respectively. For qualitative evaluation, the percentages of “perfect segmentation” (score of 3) and “good segmentation” (score of 2) are 99.4% (in healthy subjects) and 98.7% (in DR patients), respectively. This work promotes the application of watershed algorithm in FAZ segmentation, making it a useful tool for analyzing and diagnosing eye diseases.

Adipose tissue‑derived stem cells (ASCs) are beneficial for myocardial regeneration. The physiological oxygen content of human organs is estimated to range between 1 and 11%. However, in the majority of previous in vitro studies with cultured ASCs, the O2 concentration was artificially set to 21%. The present study aimed to compare the protective effects of rat ASCs on neonatal rat ventricular myocytes (NRVMs) under normoxic (21% O2) and physioxic (5% O2) conditions. Rat NRVMs cultured under normoxia or physioxia were treated with H2O2 or left untreated, and further co‑cultured with ASCs in 21% or 5% O2. The apoptosis of NRVMs was evaluated by Annexin V staining and quantitating the protein levels of Bcl‑2 and Bax by western blotting. The oxidative stress of NRVMs was determined by a glutathione/oxidized glutathione assay kit. The concentrations of secreted vascular endothelium growth factor (VEGF), insulin like growth factor‑1 (IGF‑1) and basic fibroblast growth factor (bFGF) in the culture medium were quantified by enzyme‑linked immunosorbent assay. Under both normoxia and physioxia, co‑culture with ASCs protected H2O2‑exposed NRVMs from apoptosis and significantly alleviated the oxidative stress in NRVMs. The protective effects of ASCs were associated with increased secretion of VEGF, IGF‑1 and bFGF. ASCs cultured in 5% O2 exhibited certain cardioprotective effects against H2O2 stress. The results of the present study suggested that O2 concentrations influenced the cardioprotective effects of ASCs. VEGF, IGF‑1 and bFGF may serve a role in the myocardial regeneration mediated by transplanted ASCs.

Novel adsorbents from raw corn stalks (RCS) were synthesised after cellulose isolation followed by modification with epichlorohydrin, N,N-dimethylformamide, pyridine and diethylamine. The MCCS (modified cellulose from corn stalks) products were characterised by thermogravimetric analysis, elemental analysis, scanning electron microscopy–energy dispersive spectrometry (SEM-EDS) and Fourier transform infrared spectroscopy (FT-IR); moreover, the adsorption characteristics of nitrate and phosphate on MCCS were investigated in binary systems using batch adsorption procedures. The mass loss of RCS and MCCS may be divided into three stages and the modification reaction increased the stability of samples. The surface of MCCS was rougher than that of RCS and amine groups were successfully loaded onto MCCS, as shown by elemental analysis results and FT-IR spectra. The pseudo-second order kinetics equation and Langmuir isotherm could well describe the adsorption process, and the maximum adsorption capacities (298 K) of nitrate and phosphate on MCCS as calculated from the Langmuir isotherm were 13.6054 and 22.8833 mg/g, respectively. The obtained thermodynamic parameters indicated the spontaneous and exothermic nature of adsorption.

A portable and power-free microfluidic device was designed for rapid and sensitive detection of lead (Pb(2+)). 11-mercaptoundecanoic acid (MUA)-functionalized gold nanoparticles (MUA-AuNPs) aggregated in the presence of Pb(2+) for the chelation mechanism. When we performed this analysis on a polydimethylsiloxane (PDMS) microfluidic chip, the aggregations deposited onto the surface of chip and formed dark lines along the laminar flows in the zigzag microchannels. This visual result can be observed by the naked eye through a microscope or just a drop of water as a magnifier. Ten μM Pb(2+) was successfully detected.

Batch adsorption procedures were conducted to remove methylene blue (MB) from aqueous solutions with fly ash (FA). The samples of FA were characterized by scanning electronic microscopy (SEM), and the effects of initial pH value, contact time, MB concentration and dosage of FA on removal efficiency were investigated. The holey characteristics and rough surface of FA made it possible to purify wastewater containing MB. It proved the reaction was fast, at the pH value of 6, the removal efficiency was optimal, lower MB concentration as well as higher dosage of FA could accelerate MB removal. The regeneration reaction on FA with 200 mL of C 3 H 6 O for 30 min was more effective than others. FA was effective in wastewater purification for MB, the ease of handling and low cost made it potential in practical application.

Fly ash (FA) was used as adsorbent to remove methylene blue (MB) in aqueous solutions, adsorption kinetics and isotherm equations were analyzed to reveal the characteristics, optimal operation conditions were attained through orthogonal experiments. The results revealed that FA was acceptable on MB removal. The process was a pseudo-second-order reaction and fit Langmuir isotherm equation better with correlation coefficients of R2 0.9989 and the maximum adsorption capacity 11.0865 mg/g, the reaction could proceed spontaneously and the reaction was endothermic. Orthogonal experiments indicated that of MB concentration 20 mg/L, dosage of FA 0.5 g and initial pH value 5 was optimal, the average removal efficiency was 98.77%. FA was appropriate to remove MB and Cr(III) together in aqueous solutions. With acceptable removal efficiency and lower cost, the reaction system with FA was potential in future utilization for wastewater purification.

The paper investigated the treatment effect of modified rice husk as an adsorbent on wastewater containing Zn(Ⅱ). Langmuir and Freundlich equations quantified the Zn(Ⅱ) removal effect of modified rice husk. We analyzed characteristics of adsorption kinetics, the initial pH value, temperature effect on adsorption process, and compared with the regeneration efficiency of adsorbent. The results showed that: compared to the non-modified rice husk, modified rice husk's Zn(Ⅱ) adsorption capacity significantly increased from 12.41 mg•g-1 to 21.32 mg•g-1. Pseudo-second-order kinetic equation fitted adsorption process better, coefficient R was 0.9731. The best pH value with which modified rice husk removed Zn(Ⅱ) was 5. Adsorption capacity reached to 15.07 mg•g-1, and changes in pH value were little before and after adsorption. Effects of temperature on the adsorption process were very small and can be ignored. HCL, H2SO4 and HNO3 of different concentrations and volumes all had desorption capacity to some degree, a desorption rate was mostly between 40%-50%. It was feasible to remove Zn(Ⅱ) in wastewater with modified rice husk. The study of batch adsorption experiments can provide reference for the research of dynamic adsorption experiments and adsorption mechanism.