Differential distribution of fibrovascular proliferative membranes in 25-gauge vitrectomy for proliferative diabetic retinopathy.

Aim: To analyze the distribution of fibrovascular proliferative membranes (FVPMs) in proliferative diabetic retinopathy (PDR) patients that treated with pars plana vitrectomy (PPV), and to evaluate the outcomes separately.

Methods: This was a retrospective and cross-sectional study. Consecutive 25-gauge (25-G) PPV cases operated for PDR from May 2018 to April 2020.

[Spectral Characteristics of Dissolved Organic Matter (DOM) Derived from Water and Sediment in Normal Flow Period of the Intersection Zone of Jing River and Wei River].

As the representative component for eco-environmental researchers, dissolved organic matter (DOM) is playing a significant role for the indication effect on environmental quality and efficiency assessment on remediation approaches. Nowadays, it lacks related investigation on DOM derived from rivers and sediments, and the advanced discussion is in urgent need because of the dynamic variations of experimental target, such as spatial-temporal condition, hydrological condition, environmental condition and research dimension. The spectral approaches, including elemental analysis, ultraviolet spectra (UV), Fourier transform infrared spectroscopy (FT-IR), Raman spectra (Raman), three dimensional excitation emission matrix fluorescence spectroscopy (3D-EEMs) and nuclear magnetic resonance (NMR) were used to reveal the characteristics of DOM derived from water and sediment samples in the intersection zone of Jing River and Wei River (Gaoling District, Xi’an City, Shaanxi Province).

[Spectral Evidence of In-Situ Regulatory Mechanisms on Chemical Speciation of Lead/Cadmium Affected by Dissolved Organic Matter Extracted from Rhizosphere Loess of Calendula Officinalis Seedling].

The various characteristics of DOM have great impact on the transformation process of contaminants in soil due to the generation of the feedback regulation in cycles of plant, Rhizosphere soil and environmental contaminants. Currently, more attention was paid on contaminants behaviors of adsorption, transformation, accumulation and detoxification than DOM derived from Rhizosphere soil. The chemical speciation of lead/cadmium and growth efficiency related variations were revealed in the growth process of Calendula officinalis seedlings, and the spectral characteristics of DOM in Rhizosphere loess were discussed with UV, FT-IR and 3D-EEMs spectra.

[Determination of Lead and Cadmium in Calendula Officinalis Seedlings for Phytoremediation of Multi-Contaminated Loess by Using Flame Atomic Absorption Spectrometry with Wet Digestion].

Atomic absorption spectrometry (AAS) is widely used in the analysis and detection of heavy metals. The optimal operation conditions on metals detection are important for the stabilization and repeatability of scientific research, which affects the expected investigation objectives greatly. Thus, it becomes a key issue to establish appropriate detection methods in scientific works.

[FTIR Analysis of Secondary Abiotic Stress Response of Calendula Officinalis Seedlings to Lead and Cadmium in Multi-Contaminated Loess].

As an environmentally-friendly technology attracting great attention from current researchers, phytoremediation is significant for site remediation contaminated by heavy metals. The plant will appear related physiological response to reduce direct harm caused by the stress of heavy metals. The microscale behavior is always multi-dimensional and difficult to detect.

[Response of FTIR and Raman Spectra on Cell Wall of Calendula Officinalis Seedlings Roots to the Co-Contamination Stress of Lead and Cadmium in Loess].

Phytoremediation is a novel method with great potential for site remediation contaminated by heavy metals in future. The cell wall of plant roots is significant to affect the remediation efficiency, for it is related to the multi-interface of heavy metals, pedosphere and plant. The relationship between cell wall of plant and heavy metals is complicated, containing the reaction behavior of physical chemistry, physiology and biochemistry.

[Study on the Mechanism to Ease the Leaching Effect of Nutrient in the Multi-Contaminated Loess Washing Process with the Addition of Anion Adsorbent(Ⅱ)].

The soil washing technology is commonly used to remediate contaminated soils because of its advantages of low cost, ease handling and environmental-friendly. However, it should be noticed that the nutrient might leach simultaneously from soil in the washing process, and the technical solution of the issue will greatly accelerate the application process of washing technology in site remediation. This paper aims to reveal the regulating mechanism of synthesized anion adsorbent from straw on nutrient leaching potential through approaches of adsorption equilibrium models (isotherms and kinetics) and spectral analysis instruments (SEM and FTIR).

[Influence Mechanism of Dissolved Organic Matter (DOM) from Straw Humification on Chemical Speciation of Lead in Loess Region].

Heavy metal is regarded as one of the most representative contaminants in soil, and the chemical speciation is greatly related to the toxicity and transformation behavior, which attracts the attention of researchers for years. The environmental factors could change the speciation of heavy metals, plus to the complexity of soil system, and the transformation variation of speciation might occasional existed under similar conditions. At present, the different viewpoints of related issues are urgent to be investigated.

[Effect of Temperatures and Lead Ions on 3D-EEMs of Dissolved Organic Matter (DOM) Derived from Straw Humification].

Straw incorporation is significant for straw reduction and reutilization, and is clearly required in the twelfth five-year-plan for national economic and social development of the People's Republic of China. The incorporated straw will naturally decompose and release the component of dissolved organic matter (DOM). At present, it lacks the research on straw humification behavior controlled by environmental factors and complexation effect between humification component and metal ions with fluorescence spectrometry in the representative region of loess.

[Effect of pH on the Ultraviolet Spectra and Fluorescence Characteristics of Dissolved Organic Matter in the Process of Straw Humification].

Crop straw is the dominant by-product from agriculture and is regarded as the new source of non-point contamination. Straw incorporation is possible to solve the issues of straw reduction and reutilization, which is clearly required in the twelfth five-year-plan for national economic and social development of the People's Republic of China. At present, it is of noticeable lack of the investigation on straw incorporation behavior and detail humification product analysis in the representative regions under different environmental conditions.

[Spectral Analysis of Dissolved Organic Matter of Tannery Wastewater in the Treatment Process].

Tannery industry is one of the major traditional industries and important wastewater sources in China. The existing research mainly focus on the quality of inlet and outlet water, rather than the purification and transformation behavior of dissolved organic matter (DOM) in the treatment process of tannery wastewater. The UV spectra and fluorescence spectroscopy were used to detect the spectral characteristics of water samples in the treatment process, and it is analyzed that the formation process and the linear relationships between total fluorescence intensity and parameters.

[FTIR and 13C NMR Analysis of Dissolved Organic Matter (DOM) in the Treatment Process of Tannery Wastewater].

Nowadays, the wastewater quantity discharged yearly from tannery industry is around 0. 2 billion t in China. The contaminants of tannery wastewater include macromolecular organic matters, such as grease, fur scraps and collagen, and the alkaline wastewater appears to be of high content of salt and COD.

[Application of Tessier-AAS to the non-biological transformation mechanism of chemical speciation of lead in red soil in agricultural area of central China].

The soil contamination of heavy metals, from the areas of mine, highway, industrial area, agricultural land and so on, is nowadays a serious issue all over the world. The contamination of heavy metals in large agricultural area might lead to the decrease of products quality and economic value. Actually, the accumulation amount of heavy metals by crops is much more related to the activated speciation, which is exchangeable and able to transform to the forms of carbonates, Fe-Mn oxides, organic matter and residual.

[Spectrum characteristics of leaching components from co-contaminated loess in ex-situ column washing reaction].

Soil contamination is regarded as one of the most serious issues to humanity all over the world. It is statistically believed that over one-fifth of the farmland, that is 20 million ha, is found to be contaminated by heavy metals in China. And the related issues, caused by soil contamination, of food safety, human health and eco-environmental quality attract much attention by public with more serious contamination than before.

[Spectral characteristics of decomposition of incorporated straw in compound polluted arid loess].

The original loess from western China was used as soil sample, the spectral methods of scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS), elemental analysis, Fourier transform infrared spectroscopy (FT-IR) and 13C nuclear magnetic resonance (13C NMR) were used to investigate the characteristics of decomposed straw and formed humic acids in compound polluted arid loess. The SEM micrographs show the variation from dense to decomposed surface, and finally to damaged structure, and the EDS data reveal the phenomenon of element transfer. The newly-formed humic acids are of low aromaticity, helpful for increasing the activity of organic matters in loess.

[Ex-situ remediation on co-contaminated arid loess in column with spectral methods].

The arid loess in northwestern China is one of the dominant soil types nationwide, the removal efficiency of Pb and chlorpyrifos in simulated co-contaminated loess was investigated by ethylene diamine tetra-acetic acid (EDTA) in ex-situ column experiment, and methods of ultraviolet spectroscopy (UV), atomic absorption spectroscopy (AAS), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier transform infrared spectroscopy (FTIR) were used to reveal the remediation characteristics and mechanism. The results showed that the flow rate and pH value of EDTA are responsible for the reaction curves. In the experimental conditions, the removal rates of Pb and chlorpyrifos are more than 70% and 90%, respectively, and the bioavailability of heavy metals decreases greatly.

[Study on the co-adsorption mechanism of Pb (II) and chlorpyrifos on arid loess in northwestern China].

The co-adsorption characteristics of Pb(II) and chlorpyrifos on arid loess were investigated with batch adsorption procedures, and the co-adsorption mechanism was studied with approaches of SEM, FT-IR, XRD and theoretical analysis. The experimental results indicated that the adsorption process of Pb(II) and chlorpyrifos on loess fit better the Langmuir isotherm, the maximum adsorption capacity of q(m) is 12.5 and 0.

[Effect of straw incorporation on three-dimensional fluorescence spectrum of dissolved organic matter in arid loess].

The three-dimensional fluorescence spectrum was used to investigate the fluorescence characterization of dissolved organic matter (DOM) before and after straw incorporation in arid loess, and the variation of humification degree and Pb(II) speciation were illustrated. The results showed that the fluorescence peaks of loess appears at the regions of lambda(ex/em) = 240-270/280-340 and lambda(ex/em) = 325/450, referred as UV fulvic-like fluorescence, and visible fulvic-like and humic-like fluorescence, respectively. After straw incorporation for 60 days, the intensity of UV fulvic-like fluorescence peaks increases, and novel humic-like fluorescence peaks appears around the region of lambda(ex/em) = 250/440 and lambda(ex/em) = 320-350/350-400.

[Spectroscopic analysis of the crystallization mechanism of synthesized zeolite with XRD and FTIR approaches].

Zeolites were synthesized from fly ash using modified one-stage method. The changes in cation exchange capacity (CEC) and chemical elements of zeolite were investigated during the synthesis process to reveal the materials and elements transformation in solid-liquid system. The approaches of XRD, SEM and FTIR were used to indicate the crystallization characteristics and mechanism.

FT-IR study on interactions between medroxyprogesterone acetate and solvent in CHCl₃/cyclo-C6H₁₂ and CCl₄/cyclo-C6H₁₂ binary solvent systems.

The intermolecular interactions between medroxyprogesterone acetate (MPA) and CHCl(3) and CCl(4) solvent in CHCl(3)/cyclo-C(6)H(12) and CCl(4)/cyclo-C(6)H(12) binary solvent systems have been studied by Fourier transform infrared spectroscopy (FT-IR). The experimental results showed that there are hydrogen bonding interactions between oxygen atoms of all carbonyl groups in MPA and hydrogen atom of CHCl(3) so as to form 1:3 complex of MPA with CHCl(3) and produce three new absorption bands at 1728.9-1736.

[FTIR and XPS analysis of characteristics of synthesized zeolite and removal mechanisms for Cr(III)].

Zeolite products were synthesized from fly ash using one-stage method, and the characteristics of zeolite were analyzed with approaches of XRD, SEM and zeta potential, the removal mechanism for Cr(III) was further investigated by FTIR and XPS. From the pH value of 8 to 12, the negative zeta potential of NaP1 zeolite products decreased from -8.72 to -24.

[Spectroscopic characterization analysis on Cr (VI) removal mechanism by low-cost adsorbent of rice husk ash].

Analyzing methods of Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction analysis (XRD) and X-ray fluorescence spectroscopy (XRF) were used to reveal the adsorption mechanism of Cr(VI) by low-cost adsorbent of rice husk ash. Results of FTIR showed that amide II band, Si--O--Si, and (O--Si--O were important for Cr(VI) removal. SEM micrographs suggested that series of needle-shaped precipitation appeared on cell surface, and inorganic precipitation mechanism and redox mechanism might work in the test.

[Cr(VI) adsorption mechanism on rice husk ash burned at low temperature by method of IR spectra].

Boehm titration method was used to analyze functional groups on cell surface of rice husk ash burned at low temperature in the present paper. Effects of initial pH value and temperature on Cr(VI) adsorption were studied, adsorption capacity was tested with the help of kinetic models and adsorption isotherms, instruments of Fourier transform infrared spectroscopy(FTIR) and scanning electron microscope (SEM) were used to check characteristics and adsorption mechanism of Cr(VI). The results indicated that optimal removing rate was achieved at initial pH value 5, and pH values of aqueous solution changed little be fore and after adsorption process.

Evaluation of water quality in Er-longshan reservoir by fuzzy model.

The Er-longshan reservoir, located in Harbin city, Heilongjiang province, plays a significant role in development of economy and society. It's one of the most important fresh water sources for drinking as well as the safeguard of flood and soil erosion. Thus, as the monitored place in this study, its water quality was measured and predicted through a fuzzy model.