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1
A cost-effective method to prepare size-controlled nanoscale zero-valent iron for nitrate reduction

Claudio Adrian Ruiz-Torres,Rene Fernando Araujo-Martinez,Gabriel Alejandro Martinez-Cas,J. Elpidio Morales-Sanchez,Tae-Jin Lee,Hyun-Sang Shin,Yuhoon Hwang,Abel Hurtado-Macias,Facundo Ruiz 대한환경공학회 2019 Environmental Engineering Research Vol.24 No.3
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 ScienceON
 
 DBpia
Nanoscale zero-valent iron (nZVI) has proved to be an effective tool in applied environmental nanotechnology, where the decreased particle diameter provides a drastic change in the properties and efficiency of nanomaterials used in water purification. However, the agglomeration and colloidal instability represent a problematic and a remarkable reduction in nZVI reactivity. In view of that, this study reports a simple and cost-effective new strategy for ultra-small (< 7.5%) distributed functionalized nZVI-EG (1-9 ㎚), with high colloidal stability and reduction capacity. These were obtained without inert conditions, using a simple, economical synthesis methodology employing two stabilization mechanisms based on the use of non-aqueous solvent (methanol) and ethylene glycol (EG) as a stabilizer. The information from UV-Vis absorption spectroscopy and Fourier transform infrared spectroscopy suggests iron ion coordination by interaction with methanol molecules. Subsequently, after nZVI formation, particle-surface modification occurs by the addition of the EG. Size distribution analysis shows an average diameter of 4.23 ㎚ and the predominance (> 90%) of particles with sizes < 6.10 ㎚. Evaluation of the stability of functionalized nZVI by sedimentation test and a dynamic light-scattering technique, demonstrated very high colloidal stability. The ultra-small particles displayed a rapid and high nitrate removal capacity from water.
2
Frequency spectra characterization of noncoding human genomic sequences

O. Paredes,Rebeca Romo‑Vázquez,Israel Román‑Godínez,Hugo Vélez‑Pérez,Ricardo A. Salido‑Ruiz,J. Alejandro Morales 한국유전학회 2020 Genes & Genomics Vol.42 No.10
Background Noncoding sequences have been demonstrated to possess regulatory functions. Its classifcation is challenging because they do not show well-defned nucleotide patterns that can correlate with their biological functions. Genomic signal processing techniques like Fourier transform have been employed to characterize coding and noncoding sequences. This transformation in a systematic whole-genome noncoding library, such as the ENCODE database, can provide evidence of a periodic behaviour in the noncoding sequences that correlates with their regulatory functions. Objective The objective of this study was to classify diferent noncoding regulatory regions through their frequency spectra. Methods We computed machine learning algorithms to classify the noncoding regulatory sequences frequency spectra. Results The sequences from diferent regulatory regions, cell lines, and chromosomes possessed distinct frequency spectra, and that machine learning classifers (such as those of the support vector machine type) could successfully discriminate among regulatory regions, thus correlating the frequency spectra with their biological functions Conclusion Our work supports the idea that there are patterns in the noncoding sequences of the genome.
3
Preparation of air stable nanoscale zero valent iron functionalized by ethylene glycol without inert condition

Ruiz-Torres, Claudio Adrian,Araujo-Martí,nez, René,Fernando,Martí,nez-Castañ,ó,n, Gabriel Alejandro,Morales-Sá,nchez, J. Elpidio,Guajardo-Pacheco, Jesú,s Mar& Elsevier 2018 Chemical Engineering Journal Vol.336 No.-
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Abstract The use of nanoscale zero-valent iron has been widely studied in recent years for potential application in environmental engineering, due to its affinity for a large number of contaminants, which may be in aqueous or solid phase, and for its abundance, which makes it an attractive tool for environmental remediation. However, there exist some variables in the production of nZVI that complicate the generation of the material, such as the complex methodologies of synthesis and the cost of inert conditions like nitrogen or argon atmosphere, which have the purpose of preventing the oxidation and reducing the instability of the material under ambient conditions. As a simple and economical synthesis methodology, this work presents an optimized method to synthesize functionalized nanoscale zero-valent iron (nZVI) using ethylene glycol (EG) without need for inert conditions. The coordination of iron ions during the nZVI-EG synthesis and the functionalization mechanism of the nanoparticles were identified by UV–Vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). Functionalized nZVI showed increased dispersibility due to the effects of steric repulsion between the grafted polymers. Ethylene glycol functionalized nZVI showed stability against oxidation during dry atmospheric condition, while significant oxidation was observed in the case of unfunctionalized nZVI. This result was also correlated with actual capacity for contaminant reduction. Therefore, the possibility was verified of using ethylene glycol in an effective surface modification method to prepare air stable nZVI for environmental remediation. Highlights <UL> <LI> Air-stable nZVI could be prepared by ethylene glycol without inert condition. </LI> <LI> Smaller and narrower size distribution could be obtained by functionalization. </LI> <LI> The nZVI-EG exhibited a protection effect against oxidation in oxic conditions. </LI> <LI> The reaction kinetics was not hindered by the organic functionalization agent EG. </LI> </UL> Graphical abstract [DISPLAY OMISSION]