Manuel Valiente

• Professor at Autonomous University of Barcelona

Selenium (Se) is an essential micronutrient, yet its deficiency remains a global concern. This study investigates the biofortification of alfalfa (Medicago sativa cv. ProINTA Super Monarca GR9) via foliar Se application to enhance Se accumulation and transformation into bioavailable organic forms. A controlled environment experiment in a plant grow...

Persistent pharmaceutical contaminants, such as Platinum cytostatics, commonly used in cancer therapy, have been detected in water bodies at low concentrations. Electrochemical, photochemical and biological treatments for the removal and degradation of these contaminants are expensive and sometimes ineffective. Sorption methods are a viable and mor...

Increasing levels of boron in water exceeding acceptable thresholds have triggered concerns regarding environmental pollution and adverse health effects. In response, significant efforts are being made to develop new adsorbents for the removal of boron from contaminated water. Among the various materials proposed, inorganic adsorbents have emerged...

Mercury (Hg) pollution in agricultural soils and its potential pathway to the human food chain can pose a serious health concern. Understanding the pathway of Hg in plants and how the speciation may change upon interaction with other elements used for biofortification can be critical to assess the real implications for the final plant-based product...

Plastics with nanosize (nanoplastics, NPLs) must be characterized, since they can be toxic or act as carriers of organic and inorganic pollutants, but there is a lack of reference materials and validated methods in the nanosize range. Therefore, this study has focused on the development and validation of a separation and size characterization metho...

To efficiently remove trace Pt-based cytostatic drugs (Pt-CDs) from aqueous environments, a comparative investigation was conducted on the adsorption behavior of three commercial adsorbents including cysteine-functionalized silica gel (Si-Cys), 3-(diethylenetriamino) propyl-functionalized silica gel (Si-DETA) and open-celled cellulose MetalZorb® sp...

Olivetol (OLV), as a cannabidiol (CBD) analog, was incorporated in γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes as potential analgesic drug delivery systems (DDS) for dental hypersensitivity (DH) treatment. These DDS have been scarcely employed in oral health, being the first t...

Wheat can be biofortified with different inorganic selenium (Se) forms, selenite or selenate. The choice of Se source influences the physiological response of the plant and the Se metabolites produced. We looked at selenium uptake, distribution and metabolization in wheat exposed to selenite, selenate and a 1:1 molar mixture of both to determine th...

Mercury (Hg) pollution in agricultural soils and its potential pathway to the human food chain continues being a health concern, whereas selenium (Se) biofortification of crops grown in Se-poor soil regions is becoming a common practice to avoid health issues derived from Se deficient diets. Understanding the pathway of Hg in plants grown under Se...

In this study, a commercial cube-shaped open-celled cellulose sponge adsorbent was modified by in-situ co-precipitation of superparamagnetic iron oxide nanoparticles (SPION) and used to remove As(V) from aqueous solutions. Fe K-edge X-ray absorption spectroscopy (XAS) and TEM identified maghemite as the main iron phase of the SPION nanoparticles wi...

The limitations to assess dental enamel remineraliza-tion have been overcome by a methodology resulting from the appropriate combination of synchrotron radiation-based techniques on both, infrared microspectroscopy and micro X-ray diffraction, with the help of specific data mining. Since amelogenin plays a key role in modulating the mineralization...

Objectives To compare the side effects of typical whitening treatments (by means of oxidation) compared to the new treatment developed by the authors through reduction. The aim is to provide information about the chemical interactions of the encapsulated reductant agent (metabisulfite, MBS) with the enamel structure compared with carbamide peroxide...

This study aims to develop an innovative dental product to remineralize dental enamel by a proper combination of ion-exchange resins as controlled release of mineral ions that form dental enamel, in the presence of amelogenin to guide the appropriate crystal growth. The novel product proposed consists of a combination of ion-exchange resins (weak a...

Hypothesis The easy aggregation of superparamagnetic iron oxide nanoparticles (SPION) greatly reduces their adsorption performance for removing arsenic (As) from polluted water. We propose to exploit the porosity and good diffusion properties of a cube-shaped cellulose sponge for loading SPION to reduce the aggregation and to develop a composite ad...

Nephrolithiasis is a multifactor disease that produces nephrolites in the kidneys. Calcium oxalate hydrate (dihydrated, COD, or monohydrated, COM) stones are the most common ones with more than sixty percent incidence worldwide. They are related to different pathologies, COD with hypercalciuria and COM with hyperoxaluria. COD is an unstable species...

The uncontrolled release of pharmaceutical drugs into the environment raised serious concerns in the last decades as they can potentially exert adverse effects on living organisms even at the low concentrations at which they are typically found. Among them, platinum based cytostatic drugs (Pt CDs) are among the most used drugs in cancer treatments...

An appropriate selenium intake can be beneficial for human health. Se-biofortified food in Se-deficient regions is becoming an increasingly common practice but there are still issues to be addressed regarding the observed Se-induced toxicity to the plant. In this respect, plant biostimulants are used to enhance nutrition efficiency, abiotic stress...

Calcium oxalate can be found in humans as kidney stones and in cultural heritage as films in two crystallographic species, dihydrate (COD/weddellite) and/or monohydrate (COM/whewellite). Due to its instability, COD is transformed into COM. Studying this crystalline conversion provides information about the origin of the monohydrated species, which...

AimSelenium (Se) can induce stress in plants. Our main purpose is to assess the effect of a biostimulant, based on hetero-polyoxometalates mixed with humic acids, on Se bio-fortified wheat plants. Secondly, to evaluate a possible modification of the Se species in the plant tissues and to investigate the response of phytohormones.Method Wheat plants...

Kidney stones are collections of microcrystals formed inside the kidneys, which affect 6–12% of the population worldwide, with an increasing recurrence (50–72%) after the first episode. The most abundant type is calcium oxalate (66%), described as monohydrated (COM) and dihydrated (COD). An issue in their chemistry is the transformation process of...

Tooth whitening materials have not undergone relevant advances in the last years. Current materials base their action on the oxidant activity of peroxides, which present the disadvantage of requiring long application times, along with unpleasant side effects of dental hypersensitivity (e.g. sharp pain). In this work, a novel tooth whitening formula...

The periodic application of copper-based fungicides (Bourdeaux mixture) to vineyards of the Mediterranean region has generated an important pollution source that in some cases requires a quick intervention due to the high bioavailable copper content measured. Despite some vineyards were abandoned 40 years ago, noticeable amounts of Cu and other man...

This paper suggests a new alternative for the acceleration of dye removal by adopting alternating current instead of direct current in the treatment of methylene blue solutions and industrials effluents, using anodic oxidation on Pb/PbO2 and stainless steel (SS)/PbO2 anodes. A comparative study of the influence of electrolyte support (NaCl, NaNO3,...

Objective: The aim is to review the most important aspects about tooth whitening treatments, their side effects, and the new emerging approaches to overcome them. Overview: This review is focused on origin of tooth stains, the whitening systems and their chemistry, their side effects, and the new approaches. The search of bibliography of the per...

Ordered mesoporous Al2O3 and Fe-Al2O3 materials were synthesized at room temperature by an easy and environmentally friendly self-assembly sol-gel route, to be tested for arsenic removal. Solid samples were thoroughly characterized by several techniques. Synthetized and commercial alumina samples were evaluated as adsorbents for the removal of domi...

Superparamagnetic iron nanoparticles (SPION) have been functionalized with 3-mercaptopropionic acid (3-MPA), characterized and applied for the removal of Ag⁺, Hg²⁺ and Pb²⁺ metal ions from aqueous solutions by iron oxide (Fe3O4). The heavy metal adsorption has been investigated by means of ICP-OES and isothermal titration calorimetry. Experimental...

p>El uso de programas de regresión multiparamétrica es una herramienta muy empleada en la actualidad para el análisis de datos en Química. Con el objeto de ilustrar una de sus aplicaciones, se realizó un estudio de equilibrios de distribución líquido-líquido empleando el programa LETAGROP-DISTR. El conjunto de datos estudiado se generó por modelaci...

Contaminants of Emerging Concerns (CECs) have been introduced as one type of recalcitrant pollutant sources in water. In this study, the non-steroidal anti-inflammatory drug diclofenac (DCF) has been removed from water solutions using Molecularly Imprinted Polymer (MIP), synthetized via bulk polymerization with allylthiourea (AT) as the functional...

The adsorption of Pt(IV) by iron oxide (Fe3O4) superparamagnetic nanoparticles (SPION) functionalized with 3-mercaptopropionic acid (3-MPA) is investigated by means of inductively coupled plasma optical emission spectrometry and isothermal titration calorimetry. Experimental ICP data are better fitted by Langmuir rather than Freundlich isotherms. T...

Pharmaceutical compounds in surface waters are an emerging environmental concern due to their biological activity, which consequently present a new challenge for drinking water and wastewater treatment systems. In this work, diclofenac(DCF) and indomethacin (IDM) have been used as target molecules or templates in orderto be removed by means of mole...

The use of human teeth as biomarkers has been previously applied to characterize environmental exposure mainly to metal contamination. Difficulties arise when the contaminants are volatile or its concentration level is very low. This study presents the development of a methodology based on the transport through hollow fibre membrane liquid-phase mi...

We have examined the potential of discriminant inorganic constituents (trace-, ultra-trace elements and Sr isotope ratios) to assess the origin of world famous brands of European dry-cured hams. The variation of the multielemental composition with principal component analysis allowed to discriminate the origin of Bayonne hams. Determined ratio ⁸⁷Sr...

Mining activity is one of the most important sources of Heavy metals in the environment. In Marrakech region, functioning or abandoned mines represent a great hazard due to huge amounts of waste deposited in waste dumps and tailings often with high concentration of heavy metals pollution. These mining sites located near Marrakesh contain mining res...

Kidney stone formation is a common disease and the incidence rate is constantly increasing worldwide. It has been shown that the classification of kidney stones can lead to an important reduction of the recurrence rate. The classification of kidney stones by human experts on the basis of certain visual color and texture features is one of the most...

Applications of benzene, toluene, ethylbenzene, and o-, m-, and p-xylenes (BTEX) release them into the environment exposing living organism. These endocrine disruptors are toxic, highly volatile and easily absorbed by the lungs and can cause adverse consequences for the human health as neurological diseases and cancer. A method for the analysis of...

Novel nanocomposite sorbents of superparamagnetic iron oxide nanoparticles (SPION) supported onto electrospun polyacrylonitrile nanofibers were synthesized by a simple and scalable method. The influence of both nanofiber size and SPION loading on AsIJV) adsorption capacity was studied and optimization was conducted. A maximum uptake capacity of 32.5...

Mesoporous Hierarchical Alumina Microspheres (HAM) with high efficiency for fluoride removal have been synthesized and characterized. Two types of HAM, differing mostly in crystallinity, surface area and pore size have been obtained. Fluoride adsorption studies have been carried out by means of potentiometry and Isothermal Titration Calorimetry (IT...

The analysis of urinary stones is mandatory for the best management of the disease after the stone passage in order to prevent further stone episodes. Thus the use of an appropriate methodology for an individualized stone analysis becomes a key factor for giving the patient the most suitable treatment. A recently developed hyperspectral imaging met...

Wheat (Triticum aestivum) and its derivative products account for a major source of dietary intake of selenium (Se) in humans and animals, because of its essentiality due to its presence in vital enzymes. Se antioxidant role has resulted in the popularity of agronomic biofortification practises in Se deficient areas. Controlling Se uptake, metaboli...

Evolution of urinary lithiasis is determined by the metabolism and life-style of the related patient. The appropriate classification of the stone is mandatory for the identification of the lithogenic process. In this study, cros-sections from a single stone of each of the most frequent urolithiasis types (calcium oxalate mono and dihydrate and carb...

The thermodynamic parameters for the complexation between the monodentate diethylsulfide (Et2S), the macrocyclic thioethers 1,4,7-trithiacyclononane ([9]aneS3) 1,4,7,10-tetrathiacyclododecane ([12]aneS4) and 1,4,8,11-tetrathiacyclotetradecane ([14]aneS4) have been determined in dimethylsulfoxide (DMSO) with d(10) metal ions such as Hg2+, Ag+, Cd(2+...

To evaluate the influence of chronic stress (CS) on urine composition of calcium oxalate (CaOx) stone patients and controls. This case-control study enrolled 128 patients during a period of 20 months. The cases were CaOx stone formers with a recent stone episode. Controls were matched by sex and age. Dimensions of CS were evaluated in cases and con...

Thermodynamic parameters of complex formation between d(10) metal ions, such as Zn(2+), Cd(2+), Hg(2+) and Ag(+), and the macrocyclic thioether 1,4,7-trithiacyclononane ([9]AneS3) or the monodentate diethylsulfide (Et(2)S), in acetonitrile (AN) at 298.15 K, were studied by a systematic methodology including potentiometry, calorimetry and polarograp...

Mining activity is one of the most important sources of Heavy metals in the environment. In Marrakech region, functioning or abandoned mines represent a great hazard due to huge amounts of waste deposited in waste dumps and tailings often with high concentration of heavy metals pollution. These mining sites located near Marrakesh contain tailings a...

The formation of kidney stones is a common and highly studied disease, which causes intense pain and presents a high recidivism. In order to find the causes of this problem, the characterization of the main compounds is of great importance. In this sense, the analysis of the composition and structure of the stone can give key information about the...

Objective: To study the possible effects caused by the interaction of some urinary components on the inhibition of calcium oxalate crystallization. Such interactions are susceptible to importantly change the inhibitory behavior of some urinary components by producing either positive (synergistic) or negative effects on preventing crystallization....

Problem statement: Metal mining; together with mineral smelting and processing, have contaminated the environment surrounding mine areas throughout the world exceeding natural background concentration. Approach: These processes introduce metal contaminants into the environment through gaseous and particulate emissions, waste liquids and solid waste...

The present study represents a first insight into the Draa Lasfar mine (Marrakech) to assess the possible diffusion of heavy metals and to predict the risk of their mobility in the surroundings of the mine area. The edaphologic parameters pH, electrical conductivity (EC), loss on ignition (LOI) and CaCO3 were measured according to standard methods,...

Problem statement: Metal mining; together with mineral smelting and processing, have contaminated the environment surrounding mine areas throughout the world exceeding natural background concentration. Approach: These processes introduce metal contaminants into the environment through gaseous and particulate emissions, waste liquids and solid waste...

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A stream of effluent from a mine tailings pond, containing zinc, ferrous ions and other metals, required treatment to prevent pollution and recover valuable metals. A solvent extraction (SX) process using Ionquest 290 as extractant was developed to recover the Zn from the effluent. Ferrous ions were bio-oxidized and removed by selective alkaline pr...

In vitro antioxidant capacity of thirteen genotypes of faba bean (Vicia faba L.) collected during three different growing stages (vegetative, reproductive and maturity) have been evaluated. For the vegetative stage (VS) and reproductive stage (RS) the whole plant (WP) has been used for the analysis while for the maturity stage (MS) the plant was di...

The decolourization and mineralization of a solution of an azo dye using a catalyst based on Fe(II) supported on Y Zeolite (Fe(II)-Y Zeolite) and adding hydrogen peroxide (heterogeneous Fenton process) have been studied. The catalyst was prepared by ion exchange, starting from a commercial ultra-stable Y Zeolite. All experiments were performed on a...

The environmental behavior of chromium is of concern because of its effects on human health. Health hazards associated with exposure to chromium are dependent on its oxidation state. The hexavalent form is toxic and causes adverse effects of the on the skin including dermatitis and allergic skin reactions. Its presence in the starting materials use...

Mining activity is one of the most important sources of Heavy metals in the environment. In Marrakech region, functioning or abandoned mines represent a great hazard due to huge amounts of waste deposited in waste dumps and tailings often with high concentration of heavy metals pollution. These mining sites located near Marrakesh contain mining res...

Objectives: The main objective of the present work is to study a novel antitartar system based on the in-vitro inhibition of calcium oxalate calculi formation. The system exploits the synergism effects between phytate and pyrophosphate as crystallization inhibitors. Its harmful characteristics to possible enamel damage have also been evaluated....

Objectives: The aim of this study was to evaluate the influence of several accelerator compositions on the compressive strength of grey MTA and Portland cement. Methods: For each cement (grey MTA and ordinary Portland cement) 6 different compositions were prepared by adding different amounts of accelerator compounds as listed. The accelerators us...

A novel carrier, the N‐methyl, N‐dodecyl‐ephedrinium ion, was studied for the selective transport of some aromatic amino acids [phenylalanine (Phe), histidine (His) and tryptophan (Trp)] through bulk liquid membranes. Investigations of the main parameters limiting the aided transport of the amino acids were carried out. Transport rates that resulte...

Hydroxyapatite is the main mineral component of bones and teeth. Fluorapatite, a bioceramic that can be obtained from hydroxyapatite by chemical substitution of the hydroxide ions with fluoride, exhibits lower mineral solubility and larger mechanical strength. Despite the widespread use of fluoride against caries, a reliable technique for unambiguo...

The selectivity coefficients, KIJpot, of ion-selective electrodes (ISEs) have been fundamentally related to thermodynamic parameters, but yet, the effect of temperature on KIJpot has not been studied. We describe a new approach to fine-tune the selectivity of ISEs based on the effect of temperature on selectivity coefficients. This effect was quant...

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Oxalate, citrate, uric acid and creatinine are important urine markers for the evaluation and treatment of urolithiasic patients. They have been traditionally analysed by enzymatic and chromatographic techniques which present practical drawbacks, mainly in the sample pre-treatment step. The purpose of this study was to evaluate those markers in uri...

The mobility, bioavailability and toxicity of mercury in the environment strongly depend on the chemical species in which it is present in soil, sediments, water or air. In mining districts, differences in mobility and bioavailability of mercury mainly arise from the different type of mineralization and ore processing. In this work, synchrotron-bas...

Pyrophosphate (PPi) and phytic acid (IP6) are natural phosphorous compounds with growing interest in the biomedical field due to their ability as potential inhibitors of urolithiasis among others. Existing methodologies for their evaluation show inconveniences mainly associated with sample treatment, matrix interferences and lack of resolution. The...

This study compares analytical figures of merit such as sensitivity, background, % 140Ce16O+/140Ce+, 40Ar16O+, time dependent and matrix induced interference effects for solutions containing up to 500 mg L−1 Na for a conventional sampler cone designated as the High Performance Interface (HPI) with that obtained with a so-called Xi cone. HPI counts...

Zn is a typical metal component of acidic mining waters. Its selective recovery is a goal to valorize such effluents and also to minimize the cost for the mandatory treatment of such effluents. To this purpose, a solvent extraction process was developed successfully in our laboratories after comparing the results of applying different organophospho...

A new self-tuning single-mode-focused microwave technology has been evaluated in this work to perform the quantitative routine extraction of organometallic species from solid matrices of environmental interest. Species-specific isotope dilution analysis has been employed to better investigate the real influence of the microwave-assisted extractions...

Accelerated methods for partitioning of Cd, Cr, Cu, Ni, Pb and Zn, such as the use of single and ultrasonic ex-tractions are assessed in terms of readsorption and compared with the three-stage sequential extraction scheme (SES) of the Standards Measurements and Testing Programme (SM&T). The standard addition approach was employed for charac-terisin...

The purpose of this study has been to investigate the influence of key parameters (i.e., the structure of the resin organic polymer and its particle size, as well as the temperature of the process) on the release of calcium and fluoride ions from cationic and anionic ion exchange resins of strong character, in order to develop a formulation for a c...

Nowadays there is a great concern about new adsorbent materials for either the removal or fixation of arsenic species because of their high toxicity and the health problems associated with such species. In this paper the kinetics of absorption of As(V) on Fe(III)-loaded sponge have been studied and the results are compared with those of other natur...

The aim of the present work is concerned with a study of the kinetics of release of both Ca2+ and F− from the corresponding loaded ion-exchange resins (weak acid and weak base character for Ca2+ for F−, respectively), using both dynamic and batch experimental conditions with an artificial saliva solution as the ion-exchange media at 293 and 310K. T...

The pollution emitted by traffic activities and road maintenance is an area of great interest as contaminants can be transported to roadside sediments and pose a risk to environmental and human health. In the presentwork, deposited pollution in roadside sediments has been assessed by sampling along a highly traveled highway in Barcelona and the sur...

Metallurgic calcines with very high mercury and methylmercury content from the Almadén mining district were analyzed by synchrotron-based microprobe techniques. Information about mercury speciation was obtained by micro-EXAFS (microscopic extended X-ray absorption fine structure) spectroscopy, whereas elemental associations were evaluated by micro-...

Soil samples collected in the surroundings of a chlor-alkali plant in the Netherlands were characterised by synchrotron-based techniques and conventional analytical procedures, in order to evaluate the environmental impact of Hg emissions and other heavy metals present in these locations. Analysis of total metal content by inductively coupled plasm...

Poster

myo-Inositol hexaphosphate (InsP6) widely occurs in plant seeds. At present, some important benefits of InsP6 for human health have been described. The purpose of this study was to find the best condition for the optimum absorption of orally administered InsP6, evaluated by InsP6 urinary excretion. The influence of different stomach conditions (emp...

This manuscript describes the analysis and evaluation of mercury species present in three different types of samples (ore, slag and soil) belonging to the abandoned mining area of Almadén (Spain), by means of X-ray Absorption Spectroscopy (XAS) techniques. The applied methodology includes the analysis of possible interfering compounds by ICP-OES an...

The present work studies the adsorption behaviour of mercury species on different soil components (montmorillonite, kaolinite and humic acid) spiked with CH3HgCl and CH3HgOH at different pH values, by using XAS techniques and bacterial mercury sensors in order to evaluate the availability of methyl mercury on soil components. The study details and...

The aim of this study was to examine the possible effects of some trace metals on the inhibition of calcium oxalate crystallization. A test of urinary lithogenic risk was used to follow the crystallization of calcium oxalate from artificial urine in the presence of several metal ions assayed in their physiological concentrations. Interactions of th...

To evaluate the effects for cytotoxicity of two dentifrices: a toothpaste commercially available (Crest Extra-Whitening toothpaste) and a new experimental toothpaste based on a mixture of ion-exchange resins (named NMTD) that supplies calcium, fluoride, phosphate and zinc ions. Cultures of mouse fibroblasts cells L929 were used in a MTT assay for i...

Chiral activated membranes were prepared and tested for the enantioseparation of the racemic drug SR-propranolol. Polysulfone (PS) based membranes were investigated for this purpose, and N-Hexadecyl-l-hydroxyproline (HHP) was tested as a chiral carrier. The prepared membranes were characterized using two different membrane modules. In both cases, t...

The mobility, availability and persistence of Heavy Metals (HMs), As, Cd, Cu, Ni, Pb and Zn, in contaminated soils of a former abandoned mining area were evaluated by means of a sequential extraction scheme (SES) and applying a multivariate statistical analysis to the obtained data. Chemical partitioning of HMs in each sample was determined in four...

A supported liquid membrane (SLM) containing the chiral selector N‐hexadecyl‐L‐hydroxyproline (HHP) was characterized for the enantioseparation of a β‐blocking drug. SR‐propranolol was the target racemic mixture to be resolved by the membrane separation system. The different affinity shown by the selected carrier, HHP, for the two propranolol enant...

The results presented in this work deal with the prime application of activated composite membranes (ACMs) for the transport of Hg(II) ions in a continuous extraction-re-extraction system using di-(2-ethylhexyl)dithiophosphoric acid (DTPA) as carrier. The effects of variables such as the pH, the nature of the acid and the concentration of the casti...

An indirect method is described for determination of phytate in human urine. The method is based on hydrolysis of the phytate and determination of myo-inositol, one of the hydrolysis products. Chromatographic separations were performed on an Aminex HPX-87C column with Milli-Q water as mobile phase; 5 mM ammonium acetate was added post-column. The d...