ABSTRACT
In this work, the electrochemical behavior of the glycosylated flavonoid kaempferitrin was studied, and an electroanalytical methodology was developed for its determination in infusions of Bauhinia forficata using a boron-doped diamond electrode (BDD). The electrochemical behavior of the flavonoid was studied by cyclic voltammetry, and two irreversible oxidation peaks at 0.80 and 1.0 V vs Ag/AgCl were observed. The influence of the pH on the voltammograms was examined, and higher sensitivity was found at pH 7.0. The electrochemical process corresponding to peak 1 at 0.80 V is predominantly diffusion-controlled, as the study shows at varying scan rates. An analytical plot was obtained by square wave voltammetry at optimized experimental conditions (frequency = 100 s-1, amplitude = 90 mV, and step potential = 8 mV) in the concentration range from 3.4 µmol L-1 to 58 µmol L-1, with a linearity of 0.99. The limit of detection and limit of quantification values were 1.0 µmol L-1 and 3.4 µmol L-1, respectively. Three samples of Bauhinia forficata infusions (2 g of sample in 100 mL of water) were analyzed, and the KF values found were 5.0 × 10-4 mol L-1, 3.0 × 10-4 mol L-1, and 7.0 × 10-4 mol L-1, with recovery percentages of 98 %, 106 % and 94 %, respectively. Finally, experiments were performed with two other flavonoids (chrysin and apeginin) to compare and propose an electrochemical oxidation mechanism for kaempferitrin, which was supported by quantum chemical calculations.
Subject(s)
Electrochemical Techniques , Kaempferols , Oxidation-Reduction , Kaempferols/chemistry , Kaempferols/analysis , Electrochemical Techniques/methods , Glycosylation , Electrodes , Bauhinia/chemistry , Quantum Theory , Flavonoids/chemistry , Flavonoids/analysis , Limit of Detection , Diamond/chemistryABSTRACT
Lysergic acid diethylamide (LSD) and two phenethylamine classes (NBOHs and NBOMes) are the main illicit drugs found in seized blotter papers. The preliminary identification of these substances is of great interest for forensic analysis. In this context, this work constitutes the inaugural demonstration of an efficient methodology for the selective detection of LSD, NBOHs, and NBOMes, utilizing a fully 3D-printed electrochemical double cell (3D-EDC). This novel 3D-EDC enables the use of two working electrodes and/or two supporting electrolytes (at different pHs) in the same detection system, with the possibility of shared or individual auxiliary and pseudo-reference electrodes. Thus, the selective voltammetric detection of these substances is proposed using two elegant strategies: (i) utilizing the same 3D-EDC platform with two working electrodes (boron-doped diamond (BDD) and 3D-printed graphite), and (ii) employing two pH levels (4.0 and 12.0) with 3D-printed graphite electrode. This comprehensive framework facilitates a fast, robust, and uncomplicated electrochemical analysis. Moreover, this configuration enables a rapid and sensitive detection of LSD, NBOHs, and NBOMes in seized samples, and can also provide quantitative analysis. The proposed method showed good stability of the electrochemical response with RSD <9 % for Ip and <5 % for Ep, evaluating all oxidation processes observed for studied analytes (n = 7) at two pH levels, using the same and different (n = 3) working electrodes. It demonstrates a broad linear range (20-100 and 20-70 µmol L-1) and a low LOD (1.0 µmol L-1) for quantification of a model molecule (LSD) at the two pHs studied. Hence, the 3D-EDC combined with voltammetric techniques using BDD and 3D-printed graphite electrodes on the same platform, or only with this last sensor at two pH values, provide a practical and robust avenue for preliminary identification of NBOHs, NBOMes, and LSD. This method embodies ease, swiftness, cost-efficiency, robustness, and selectivity as an on-site screening tool for forensic analysis.
Subject(s)
Electrochemical Techniques , Electrodes , Lysergic Acid Diethylamide , Printing, Three-Dimensional , Lysergic Acid Diethylamide/analogs & derivatives , Lysergic Acid Diethylamide/chemistry , Lysergic Acid Diethylamide/analysis , Electrochemical Techniques/methods , Phenethylamines/analysis , Illicit Drugs/analysis , Humans , Limit of Detection , Graphite/chemistryABSTRACT
This work presents a novel multielectrode array (MEA) to quantitatively assess the dose enhancement factor (DEF) produced in a medium by embedded nanoparticles. The MEA has 16 nanocrystalline diamond electrodes (in a cell-culture well), and a single-crystal diamond divided into four quadrants for X-ray dosimetry. DEF was assessed in water solutions with up to a 1000 µg/mL concentration of silver, platinum, and gold nanoparticles. The X-ray detectors showed a linear response to radiation dose (r2 ≥ 0.9999). Overall, platinum and gold nanoparticles produced a dose enhancement in the medium (maximum of 1.9 and 3.1, respectively), while silver nanoparticles produced a shielding effect (maximum of 37%), lowering the dose in the medium. This work shows that the novel MEA can be a useful tool in the quantitative assessment of radiation dose enhancement due to nanoparticles. Together with its suitability for cells' exocytosis studies, it proves to be a highly versatile device for several applications.
Subject(s)
Diamond , Electrodes , Gold , Metal Nanoparticles , Diamond/chemistry , Metal Nanoparticles/chemistry , Gold/chemistry , Silver/chemistry , Platinum/chemistry , Radiation Dosage , Humans , X-Rays , Nanoparticles/chemistryABSTRACT
One challenge of the citrus industry is the treatment and disposal of its effluents due to their high toxicity, substantial organic load, and consequent resistance to conventional biotechnological processes. This study introduces a novel approach, using electrochemical oxidation with a boron-doped diamond anode to efficiently remove organic compounds from biodegraded pulp wash (treated using the fungus Pleurotus sajor-caju.) The findings reveal that employing a current density of 20 mA cm-2 achieves notable results, including a 44.1% reduction in color, a 70.0% decrease in chemical oxygen demand, an 88.0% reduction in turbidity, and an impressive 99.7% removal of total organic carbon (TOC) after 6 h of electrolysis. The energy consumption was estimated at 2.93 kWh g-1 of removed TOC. This sequential biological-electrochemical procedure not only significantly reduced the mortality rate (85%) of Danio rerio embryos but also reduced the incidence of morphologically altered parameters. Regarding acute toxicity (LC50) of the residue, the process demonstrated a mortality reduction of 6.97% for D. rerio and a 40.88% lethality decrease for Lactuca sativa seeds. The substantial reduction in toxicity and organic load observed in this study highlights the potential applicability of combined biological and electrochemical treatments for real agroindustrial residues or their effluents.
Subject(s)
Diamond , Water Pollutants, Chemical , Diamond/chemistry , Water Pollutants, Chemical/analysis , Electrolysis/methods , Organic Chemicals , Electrodes , Oxidation-ReductionABSTRACT
Beauty salons (BS) are places that deal with a wide range of cosmetics with potentially hazardous chemicals, and their effluent should be properly treated before going to the sewage system, once it represents characteristics of industrial wastewater. This work provides an extensive characterization of a BS effluent and its respective electrochemical treatment by comparing NaCl, Na2SO4, and Na2S2O8 as supporting electrolytes with a boron-doped diamond (BDD) as anode, applying 10 or 30 mA cm-2 of current density (j). The inclusion of UVC irradiation was also performed but the improvements achieved in removing the organic matter were null or lower. The analysis of chemical oxygen demand (COD) removal, energy consumption, and total current efficiency (TCE) was required to prove the efficacy of the processes and the comparative study of the performance of different technologies. Precipitate analysis was also done due to the high turbidity of the raw effluent and the appearance of a precipitate before and during the electrolysis, mainly with Na2S2O8. The precipitate confirmed the presence of silicates and small amounts of heavy metals. The results clearly showed that 6 h of treatment with Na2SO4 achieved 58% of COD removal with an energy consumption of about 0.52 kWh m-3, being the best electrolyte option for treating BS effluent by applying 10 mA cm-2. Under these experimental conditions, the final wastewater can be directly discharged into the sewage system with a lower amount of visible precipitate, and with 73% less turbidity. The treatment here proposed can be used as an alternative to decision-makers and governments once it can be a step further in the implementation of better and advanced politics of water sanitation.
Subject(s)
Wastewater , Water Pollutants, Chemical , Oxidation-Reduction , Sewage , Sulfates/analysis , Water Pollutants, Chemical/analysis , Electrolytes , Diamond/chemistry , ElectrodesABSTRACT
ABSTRACT Purposes: The purpose of this study is to compare the standard inner limiting membrane peeling technique to the inner limiting membrane abrasion technique with respect to visual outcomes and central retinal thickness in the primary epiretinal membrane surgery. Methods: A total of 59 eyes from 57 epiretinal membrane patients were separated into two groups including the standard inner limiting membrane peeling group and the inner limiting membrane peeling with abrasion technique group. At 6, 12, and 24 months of follow-up, the mean alteration in best-corrected visual acuity and central retinal thickness were assessed for each group. Results: The study includes 32 (54%) standard inner peeling and 27 (46%) inner limiting membrane peeling with abrasion technique patients. The mean preoperative logMAR best-corrected visual acuity for the standard inner limiting membrane peeling and inner limiting membrane peeling with abrasion groups was 0.73 (±0.29) and 0.61 (±0.3) respectively. At 6, 12, and 24 months of follow-up, the best-corrected visual acuity improved significantly in each group. At each period of observation, the alteration in best-corrected visual acuity was not statistically significant (p=0.54, p=0.52, p=0.67). When comparing the alterations between the standard inner limiting membrane peeling and inner limiting membrane peeling with abrasion technique groups at 6 months (p=0.26) and 24 months (p=0.06), no statistically significant differences were observed, but they were statistically different at 12 months (p=0.03), reflecting a greater reduction in central retinal thickness for the inner limiting membrane peeling with abrasion technique group after one year. Conclusion: Abrasion of the inner limiting membrane with a diamond-dusted membrane scraper during epiretinal membrane surgery demonstrates similar effectiveness to the standard inner limiting membrane peeling technique. At 12 months, retinal thinning was found to be more significant in inner limiting membrane peeling with abrasion technique patients in terms of central retinal thickness values. As a result, it may be argued that the inner limiting membrane abrasion technique eliminates the inner limiting membrane and related structures more effectively while inflicting less retinal damage.
RESUMO Objetivo: Este estudo tem como objetivo comparar a técnica padrão de peeling da membrana limitadora interna com a técnica de abrasão da membrana limitadora interna com relação aos resultados visuais e à espessura central da retina na cirurgia primária de membrana epirretiniana. Métodos: Cinquenta e nove olhos de 57 pacientes com membrana epirretiniana foram divididos em dois grupos, incluindo o grupo de remoção padrão da membrana limitante interna e o grupo de remoção da membrana limitante interna com técnica de abrasão. A alteração média da melhor acuidade visual corrigida e da espessura central da retina foram medidas para cada grupo aos 6, 12 e 24 meses de acompanhamento. Resultados: O estudo incluiu 32 (54%) de padrão de membrana limitante e 27 (46%) de membrana interna com técnica de abrasão. A média de logMar pré-operatório de melhor acuidade visual corrigida foi de 0,73 (±0,29) e 0,61 (±0,3) para os grupos de remoção padrão da membrana limitante interna e de remoção da membrana limitante interna com técnica de abrasão, respectivamente. A melhor acuidade visual corrigida melhorou significativamente em cada grupo aos 6, 12 e 24 meses de acompanhamento. A alteração na melhor acuidade visual corrigida não foi estatisticamente significante (p=0,54, p=0,52, p=0,67) em cada período de observação. Quanto à espessura central da retina, diferenças estatisticamente significativas não foram observadas aos 6 meses (p=0,26) e 24 meses (p=0,06), mas foram estatisticamente diferentes aos 12 meses (p=0,03) quando comparadas às alterações entre os grupos de remoção padrão da membrana limitante interna e de remoção da membrana limitante interna com técnica de abrasão, refletindo uma maior redução da espessura central da retina para o grupo de remoção da membrana limitante interna com técnica de abrasão após um ano. Conclusão: A abrasão da membrana limitante interna com um raspador de membrana com pó de diamante em cirurgia de membrana epirretiniana demonstra eficácia semelhante com a técnica de remoção padrão de membrana limitante interna. Em relação aos valores de espessura central da retina, o afinamento da retina foi mais significativo em pacientes com remoção da membrana limitante interna com técnica de abrasão aos 12 meses. Assim, pode-se argumentar que a técnica de abrasão da membrana limitante interna remove a membrana limitante interna e as estruturas relacionadas de forma mais eficaz sem causar danos significativos à retina.
ABSTRACT
In this study, we explore the potential of functionalized two-dimensional (2D) diamond for spin-dependent electronic devices using first-principles calculations. Specifically, we investigate functionalizations with either hydroxyl (-OH) or fluorine (-F) groups. In the case of an isolated layer, we observe that the quantity and distribution of (-OH) or (-F) on the 2D diamond surface significantly influence thesp2/sp3ratio of the carbon atoms in the layer. As the coverage is reduced, both the band gap and magnetic moment decrease. When the 2D diamond is placed between gold contacts and functionalized with (-OH), it results in a device with lower resistance compared to the (-F) functionalization. We predict that the maximum current achieved in the device increases with decreasing (-OH) surface coverage, while the opposite behavior occurs for (-F). Additionally, the surface coverage alone can alter the direction of current rectification in (-F) functionalized 2D diamonds. For all studied systems, a single spin component contributes to the total current for certain values of applied bias, indicating a spin filter behavior.
ABSTRACT
In this work, a new coating of boron-doped diamond ultra-nanocrystalline (U-NBDD), tailored to prevent massive formation of perchlorates during disinfection, is evaluated as electrode for the reclaiming of treated secondary wastewater by the electrochemically assisted disinfection process. Results obtained are compared to those obtained by using a standard electrode (STD) that was evaluated as a standard in previous research showing outstanding performance for this application. First tests were carried out to evaluate the chlorine speciation obtained after the electrolysis of synthetic chloride solutions at two different ranges of current densities. Concentrations of hypochlorite obtained using the U-NBDD anode at 25 mA cm-2 were 1.5-fold higher, outperforming STD anode; however, at 300 mA cm-2, an overturn on the behavior of anodes occurs where the amount of hypochlorite produced on STD anode was 1.5-fold higher. Importantly, at low current density the formation of chlorates and perchlorates is null using U-NBDD. Then, the disinfection of the real effluent of the secondary clarifier of a municipal wastewater treatment facility is assessed, where inactivation of Escherichia coli is achieved at low charge applied per volume electrolyzed (0.08 A h L-1) at 25 mA cm-2 using the U-NBDD. These findings demonstrate the appropriateness of the strategy followed in this work to obtain safer electro-disinfection technologies for the reclaiming of treated wastewater.
Subject(s)
Wastewater , Water Pollutants, Chemical , Diamond/chemistry , Disinfection/methods , Hypochlorous Acid , Perchlorates , Electrolysis/methods , Electrodes , Oxidation-Reduction , Water Pollutants, Chemical/chemistryABSTRACT
Treating domestic wastewater has become more and more complicated due to the high content of different types of detergents. In this context, advanced electro-oxidation (AEO) has become a powerful tool for complex wastewater remediation. The electrochemical degradation of surfactants present in domestic wastewater was carried out using a DiaClean® cell in a recirculation system equipped with boron-doped diamond (BDD) as the anode and stainless steel as the cathode. The effect of recirculation flow (1.5, 4.0 and 7.0 L min-1) and the applied current density (j = 7, 14, 20, 30, 40, and 50 mA cm-2) was studied. The degradation was followed by the concentration of surfactants, chemical oxygen demand (COD), and turbidity. pH value, conductivity, temperature, sulfates, nitrates, phosphates, and chlorides were also evaluated. Toxicity assays were studied through evaluating Chlorella sp. performance at 0, 3, and 7 h of treatment. Finally, the mineralization was followed by total organic carbon (TOC) under optimal operating conditions. The results showed that applying j = 14 mA cm-2 and a flow rate of 1.5 L min-1 during 7 h of electrolysis were the best conditions for the efficient mineralization of wastewater, achieving the removal of 64.7% of surfactants, 48.7% of COD, 24.9% of turbidity, and 44.9% of mineralization analyzed by the removal of TOC. The toxicity assays showed that Chlorella microalgae were unable to grow in AEO-treated wastewater (cellular density: 0 × 104 cells ml-1 after 3- and 7-h treatments). Finally, the energy consumption was analyzed, and the operating cost of 1.40 USD m-3 was calculated. Therefore, this technology allows for the degradation of complex and stable molecules such as surfactants in real and complex wastewater, if toxicity is not taken into account.
ABSTRACT
Given the importance of identifying the presence of biomarkers of human diseases in DNA samples, the main objective of this work was to investigate, for the first time, the electro-catalytic oxidation of 7-methyl-guanine (7-mGua) and 5-methyl-cytosine (5-mCyt) on a boron doped diamond electrode pre-treated cathodically (red-BDDE), using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The anodic peak potentials of 7-mGua and 5-mCyt by DPV were at E = 1.04 V and E = 1.37 V at pH = 4.5, indicating excellent peak separation of approximately 330 mV between species. Using DPV, experimental conditions such as supporting electrolyte, pH and influence of interferents were also investigated to develop a sensitive and selective method for individual and simultaneous quantification of these biomarkers. The analytical curves for the simultaneous quantification of 7-mGua and 5-mCyt in the acid medium (pH = 4.5) were: concentration range of 0.50-5.00 µmol L-1 (r = 0.999), detection limit of 0.27 µmol L-1 for 7-mGua; from 3.00 to 25.00 µmol L-1 (r = 0.998), with a detection limit of 1.69 µmol L-1 for 5-mCyt. A new DP voltammetric method for the simultaneous detection and quantification of biomarkers 7-mGua and 5-mCyt using a red-BDDE is proposed.
Subject(s)
5-Methylcytosine , Boron , Humans , Oxidation-Reduction , Electrodes , GuanineABSTRACT
Introduction: The inherited bone marrow failure syndromes (IBMFSs) are a group of rare disorders characterized by bone marrow failure (BMF), physical abnormalities, and an increased risk of neoplasia. The National Institute of Pediatrics (INP) is a major medical institution in Mexico, where patients with BMF receive a complete approach that includes paraclinical tests. Readily recognizable features, such as the hematological and distinctive physical phenotypes, identified by clinical dysmorphologists, remain crucial for the diagnosis and management of these patients, particularly in circumstances where next-generation sequencing (NGS) is not easily available. Here, we describe a group of Mexican patients with a high clinical suspicion of an IBMFS. Methods: We performed a systematic retrospective analysis of the medical records of patients who had a high IBMFS suspicion at our institution from January 2018 to July 2021. An initial assessment included first ruling out acquired causes of BMF by the Hematology Department and referral of the patient to the Department of Human Genetics for physical examination to search for specific phenotypes suggesting an IBMFS. Patients with high suspicion of having an IBMFS were classified into two main groups: 1) specific IBMFS, including dyskeratosis congenita (DC), Diamond-Blackfan anemia (DBA), Shwachman-Diamond syndrome (SDS), thrombocytopenia with absent radii (TAR), and severe congenital neutropenia (SCN); 2) undefined IBMFS (UI). Results: We established a high suspicion of having an IBMFS in 48 patients. At initial evaluation, the most common hematologic features were bicytopenia (20%) and aplastic anemia (16%); three patients received hematopoietic stem cell transplantation. Among patients with a suspicion of an IBMFS, the most common physical abnormality was minor craniofacial features in 83% of patients and neurodevelopmental disorders in 52%. The specific suspicions that we built were DBA (31%), SDS (18%), DC (14%), TAR (4%), and SCN (4%), whereas 27% of cases remained as undefined IBMFS. SDS, TAR, and SCN were more commonly suspected at an earlier age (<1 year), followed by DBA (2 years) and DC (5 years). Conclusions: Thorough examination of reported clinical data allowed us to highly suspect a specific IBMFS in approximately 70% of patients; however, an important number of patients remained with suspicion of an undefined IBMFS. Implementation of NGS and telomere length measurement are forthcoming measures to improve IBMFS diagnosis in Mexico.
ABSTRACT
Selecting the ideal anodic potential conditions and corresponding limiting current density to generate reactive oxygen species, especially the hydroxyl radical (â¢OH), becomes a major challenge when venturing into advanced electrochemical oxidation processes. In this work, a step-by-step guide for the electrochemical generation of â¢OH on boron-doped diamond (BDD) for beginners is shown, in which the following steps are discussed: i) BDD activation (assuming it is new), ii) the electrochemical response of BDD (in electrolyte and ferri/ferro-cyanide), iii) Tafel plots using sampled current voltammetry to evaluate the overpotential region where â¢OH is mainly generated, iv) a study of radical entrapment in the overpotential region where â¢OH generation is predominant according to the Tafel plots, and v) finally, the previously found ideal conditions are applied in the electrochemical degradation of amoxicillin, and the instantaneous current efficiency and relative cost of the process are reported.
ABSTRACT
Single crystal diamond (SCD) is a promising material to satisfy emerging requirements of high-demand fields, such as microelectronics, beta batteries and wide-spectrum optical communication systems, due to its excellent optical characteristics, elevated breakdown voltage, high hardness and superior thermal conductivity. For such applications, it is essential to study the optically active defects in as-grown diamonds, namely three-dimensional defects (such as stacking faults and dislocations) and the inherent defects arising from the cultivation method. This paper reports the growth of SCD films on a commercial HPHT single-crystal diamond seed substrate using a 2.45 GHz microwave plasma-assisted chemical vapor deposition (MWPACVD) technique by varying the methane (CH4) gas concentration from 6 to 12%, keeping the other parameters constant. The influence of the CH4 concentration on the properties, such as structural quality, morphology and thickness, of the highly oriented SCD films in the crystalline plane (004) was investigated and compared with those on the diamond substrate surface. The SCD film thickness is dependent on the CH4 concentration, and a high growth rate of up to 27 µm/h can be reached. Raman spectroscopy, high-resolution X-ray diffractometry (HRXRD), scanning electron microscopy (SEM), surface profilometry and optical microscopic analyses showed that the produced homoepitaxial SCD films are of good quality with few macroscopic defects.
ABSTRACT
Bone healing after a fracture has many intercalated steps that depend on the host, type of injury, and often the orthopedist. The diamond concept since 2007 has outlined 4 main facets that have to be considered as a model by the treating surgeon at the time of injury and when nonunion develops: osteogenic cells, osteoconductive scaffolds, osteoinduction, and the biomechanical environment. All of these foment fracture healing in optimal circumstances. Yet, this work proposes other facets, such as osteoimmunology and vascularity, to be considered as well in the model. These are as important as the original four, though their correlation to the original work has been less noted until more recent literature. The mindset of the orthopedist must thoroughly analyze all these facets and many more when dealing with nonunion. This work presents, probably the most significant ones, parting from the original 4-corner diamond model and expanding it to a more representative hexagon integrated model. Metaphorically, just like the strongest inorganic constituent of the bone: hydroxyapatite.
Hay múltiples pasos intercalados en la consolidación de la fractura que dependen del paciente, el tipo de fractura y frecuentemente del ortopedista. Desde su introducción en el año 2007, el concepto del diamante ha delineado 4 facetas o aristas principales que se han de tener en cuenta por el ortopedista en el momento de la lesión y cuando la no-unión de fractura ocurre: células osteogénicas, matrices osteocunductivas, osteoinducción, y el ambiente biomecánico. Otras facetas para tener en cuenta, no menos importantes, son la osteoimmunología y la vascularidad. Estas son tan importantes como las 4 facetas originales, pero la correlación entre las mismas ha sido poco notada o integrada hasta ahora. El ortopedista tratante debe analizar todas ellas en profundidad, especialmente cuando se trata de una no-unión. Este trabajo presenta las más significantes, partiendo del modelo original del diamante de 4 facetas hacia uno más representativo e integrado como el hexágono. Metafóricamente, como el elemento inorgánico más abundante y fuerte en el hueso: la hidroxiapatita.
Subject(s)
Fracture Healing , Fractures, Bone , Durapatite , HumansABSTRACT
Abstract Bone healing after a fracture has many intercalated steps that depend on the host, type of injury, and often the orthopedist. The diamond concept since 2007 has outlined 4 main facets that have to be considered as a model by the treating surgeon at the time of injury and when nonunion develops: osteogenic cells, osteoconductive scaffolds, osteoinduction, and the biomechanical environment. All of these foment fracture healing in optimal circumstances. Yet, this work proposes other facets, such as osteoimmunology and vascularity, to be considered as well in the model. These are as important as the original four, though their correlation to the original work has been less noted until more recent literature. The mindset of the orthopedist must thoroughly analyze all these facets and many more when dealing with nonunion. This work presents, probably the most sig nificant ones, parting from the original 4-corner diamond model and expanding it to a more representative hexagon integrated model. Metaphorically, just like the strongest inorganic constituent of the bone: hydroxyapatite.
Resumen Hay múltiples pasos intercalados en la consolidación de la fractura que dependen del paciente, el tipo de fractura y frecuentemente del ortopedista. Desde su introducción en el año 2007, el concepto del diamante ha delineado 4 facetas o aristas principales que se han de tener en cuenta por el ortopedista en el momento de la lesión y cuando la no-unión de fractura ocurre: células osteogénicas, matrices osteocunductivas, osteoinducción, y el ambiente biomecánico. Otras facetas para tener en cuenta, no menos importantes, son la osteoimmunología y la vascularidad. Estas son tan importantes como las 4 facetas originales, pero la correlación entre las mismas ha sido poco notada o integrada hasta ahora. El ortopedista tratante debe analizar todas ellas en profundidad, especialmente cuando se trata de una no-unión. Este trabajo presenta las más significantes, partiendo del modelo original del diamante de 4 facetas hacia uno más representativo e integrado como el hexágono. Metafóricamente, como el elemento inorgánico más abundante y fuerte en el hueso: la hidroxiapatita.
ABSTRACT
Boron-doped diamond (BDD) electrodes are regarded as the most promising catalytic materials that are highly efficient and suitable for application in advanced electrochemical oxidation processes targeted at the removal of recalcitrant contaminants in different water matrices. Improving the synthesis of these electrodes through the enhancement of their morphology, structure and stability has become the goal of the material scientists. The present work reports the use of an ultranano-diamond electrode with a highly porous structure (B-UNCDWS/TDNT/Ti) for the treatment of water containing carbaryl. The application of the proposed electrode at current density of 75 mA cm-2 led to the complete removal of the pollutant (carbaryl) from the synthetic medium in 30 min of electrolysis with an electric energy per order of 4.01 kWh m-3 order-1. The results obtained from the time-course analysis of the carboxylic acids and nitrogen-based ions present in the solution showed that the concentrations of nitrogen-based ions were within the established maximum levels for human consumption. Under optimal operating conditions, the proposed electrode was successfully employed for the complete removal of carbaryl in real water. Thus, the findings of this study show that the unique, easy-to-prepare BDD-based electrode proposed in this study is a highly efficient tool which has excellent application potential for the removal of recalcitrant pollutants in water.
Subject(s)
Boron , Water Pollutants, Chemical , Boron/chemistry , Carbaryl/analysis , Electrodes , Humans , Nitrogen/analysis , Oxidation-Reduction , Porosity , Water , Water Pollutants, Chemical/analysisABSTRACT
The electrophoretic deposition of titanium dioxide (TiO2) nanoparticles (Degussa P25) onto a boron-doped diamond (BDD) substrate was carried out to produce a photoanode (TiO2/BDD) to apply in the degradation and mineralization of sodium diclofenac (DCF-Na) in an aqueous medium using photoelectrocatalysis (PEC). This study was divided into three stages: i) photoanode production through electrophoretic deposition using three suspensions (1.25%, 2.5%, 5.0% w/v) of TiO2 nanoparticles, applying 4.8 V for 15 and 20 s; ii) characterization of the TiO2/BDD photoanode using scanning electron microscopy and cyclic voltammetry response with the [Fe(CN)6]3-/4- redox system; iii) degradation of DCF-Na (25 mg L-1) through electrochemical oxidation (EO) on BDD and PEC on TiO2/BDD under dark and UVC-light conditions. The degradation of DCF-Na was evaluated using high-performance liquid chromatography and UV-Vis spectroscopy, and its mineralization measured using total organic carbon and chemical oxygen demand. The results showed that after 2 h, DCF-Na degradation and mineralization reached 98.5% and 80.1%, respectively, through PEC on the TiO2/BDD photoanode at 2.2 mA cm-2 under UVC illumination, while through EO on BDD applying 4.4 mA cm-2, degradation and mineralization reached 85.6% and 76.1%, respectively. This difference occurred because of the optimal electrophoretic formation of a TiO2 film with a 9.17 µm thickness on the BDD (2.5% w/v TiO2, time 15 s, 4.8 V), which improved the electrocatalysis and oxidative capacity of the TiO2/BDD photoanode. Additionally, PEC showed a lower specific energy consumption (1.55 kWh m-3). Thus, the use of nanostructured TiO2 films deposited on BDD is an innovative photoanode alternative for the photoelectrocatalytic degradation of DCF-Na, which substantially improves the degradation capacity of bare BDD.
Subject(s)
Boron , Water Pollutants, Chemical , Diclofenac , Electrodes , Oxidation-Reduction , Titanium/chemistry , Water Pollutants, Chemical/chemistryABSTRACT
La Aplasia Medular pura de Células Rojas es un trastorno que se caracteriza por anemia con ausencia casi completa de precursores de células rojas en la médula ósea, con contaje de leucocitos y plaquetas normales. La anemia de Diamond-Blackfan es un síndrome de insuficiencia de la médula ósea caracterizada por anemia, reticulocitopenia y disminución de precursores eritroides en la médula ósea. Se presenta el caso de un lactante menor masculino de 2 meses de edad, sin antecedentes familiares ni perinatales de importancia, cuya madre evidencia palidez cutáneo mucosa progresiva asociado a hiporexia; acude a centro de salud donde realizan paraclínicos que reportan hemoglobina en 1,7g/dL. Se realiza frotis de sangre periférica donde se muestra serie eritroide francamente afectada con contaje granulocítico y megacariocítico normales; se realiza biopsia y aspirado de médula ósea concluyéndose aplasia medular de serie roja y en vista de otros hallazgos clínicos, se plantea posible anemia de Diamond-lackfan. Se indica tratamiento con glucocorticoides, sin embargo por respuesta insuficiente, se inicia eritropoyetina aumentando dosis de forma progresiva, a pesar de la administración de la misma, amerita transfusiones sanguíneas de forma regular; se realizan estudios de compatibilidad con familiares de primer grado resultando positivos, actualmente es candidato a trasplante alogénico de médula ósea. Se concluye que a pesar de corresponder a un síndrome poco frecuente, debe sospecharse ante la presencia de anemia severa, sin pérdida sanguínea aguda y descarte previo de otras etiologías, además se plantea que el inicio oportuno del tratamiento es fundamental para la supervivencia de estos pacientes(AU)
Pure red cell aplasia medullary is a disorder characterized by anemia with almost complete absence of red cell precursors in the bone marrow, with leukocyte count and platelets. îe Diamond-Blackfan anemia is a failure syndrome characterized by bone marrow anemia, reticulocytopenia and decreased erythroid precursors in the bone marrow. the case of an infant under 2 months of age presented no family or perinatal history major, whose mother progressive skin pallor evidence mucosa associated with hyporexia; go to health center where they perform paraclinical reporting hemoglobin 1.7 g /dL. peripheral blood smear where erythroid frankly affected with normal megakaryocytic granulocytic count shown is made; It biopsied and bone marrow aspirate concluding marrow red cell aplasia; possible anemia Diamond-Blackfan in light of other clinical findings arises. It stays with glucocorticoid treatment, however insufficient response, begins erythropoietin dose progressively increasing, despite it, warrants blood transfusions on a regular basis; compatibility studies performed with firstdegree resulting positive, currently a candidate for allogeneic bone marrow transplantation. It is concluded that despite being a rare syndrome should be suspected in severe anemia where there is acute blood loss, ruling out other etiologies; also timely initiation of treatment is critical to the survival of these patients(AU)
Subject(s)
Humans , Male , Infant , Red-Cell Aplasia, Pure , Anemia, Diamond-Blackfan , Anemia , Bone Marrow , Hemoglobins , Bone Marrow Transplantation , ErythropoietinABSTRACT
OBJECTIVE: To systematically describe the short stature of patients with Diamond-Blackfan anemia and to explore factors affecting the height development of patients with Diamond-Blackfan anemia. STUDY DESIGN: This cross-sectional study was conducted at the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, and the height, weight, and clinical data of 129 patients with Diamond-Blackfan anemia were collected from June 2020 to September 2020. RESULTS: The median height-age-z score (HAZ) of children affected by Diamond-Blackfan anemia was -1.54 (-6.36-1.96). Short stature was found in 37.98% of the patients. Specific Diamond-Blackfan anemia growth curves were developed for weight, height, and body mass index, separately for male and female patients. Multivariable logistic regression models showed that female sex (aOR 4.92; 95% CI 1.29-18.71; P = .0195), underweight (aOR 10.41, 95% CI 1.41-76.98, P = .0217), cardiovascular malformations (aOR 216.65; 95% CI 3.29-14279.79; P = .0118), and RPL11(aOR 29.14; 95% CI 1.18-719.10; P = .0392) or RPS26 (aOR 53.49; 95% CI 1.40-2044.30; P = .0323) mutations were independent risk factors for short stature. In the subgroup of patients who were steroid-dependent, patients with a duration of steroid therapy over 2 years (OR 2.95; 95% CI 1.00-8.66; P = .0494) or maintenance dose of prednisone >0.1 mg/kg per day (OR 3.30; 95% CI 1.02-10.72; P = .0470) had a higher incidence of short stature. CONCLUSIONS: Patients with Diamond-Blackfan anemia had a high prevalence of short stature. The risk of short stature increased with age and was associated with sex, underweight, congenital malformations, and RPL11 or RPS26 mutations. The duration of steroid therapy and maintenance dose of steroid was significantly associated with the incidence of short stature in steroid-dependent patients with Diamond-Blackfan anemia.
Subject(s)
Anemia, Diamond-Blackfan/epidemiology , Dwarfism/epidemiology , Abnormalities, Multiple/epidemiology , Adolescent , Age Factors , Anemia, Diamond-Blackfan/drug therapy , Anemia, Diamond-Blackfan/genetics , Child , Child, Preschool , China , Cross-Sectional Studies , Dwarfism/etiology , Female , Glucocorticoids/administration & dosage , Glucocorticoids/adverse effects , Humans , Infant , Male , Mutation , Prednisone/administration & dosage , Prednisone/adverse effects , Ribosomal Proteins , Sex FactorsABSTRACT
SUMMARY: Humberto Fernández-Morán (1924-1999) a Venezuelan physician and biophysicist research, who developed the diamond knife. Furthermore he focused on improving the mechanical performance, accuracy and reliability of mocrotomes and ultramicrotomes which significantly advanced the development of electromagnetic lenses for electron microscopy based on superconducting technology. Promoter and founded of the Venezuelan Institute for Neurological and Brain Studies. He was a pioneer in electron ultra-cryomicroscopy field. Fernández-Morán taught and researched in University of Stockholm, Massachusetts Institute of Technology, Harvard University, Massachussetts General Hospital and the University of Chicago. He worked with NASA for the Apollo project in the field of physic-chemical analysis of lunar rocks.
RESUMEN: Humberto Fernández-Morán (1924-1999) médico venezolano e investigador biofísico, quien desarrolló el cuchillo de diamante. Además, se centró en mejorar el rendimiento mecánico, la precisión y la fiabilidad de los micrótomos y ultramicrótomos, lo que avanzó significativamente en el desarrollo de lentes electromagnéticos para microscopía electrónica basados en tecnología superconductora. Promotor y fundador del Instituto Venezolano de Estudios Neurológicos y Cerebrales. Fue pionero en el campo de la ultracriomicroscopía electrónica. Fernández-Morán enseñó e investigó en la Universidad de Estocolmo, el Instituto Tecnológico de Massachusetts, la Universidad de Harvard, el Hospital General de Massachussets y la Universidad de Chicago. Trabajó con la NASA para el proyecto Apollo en el campo del análisis físico-químico de rocas lunares.