Development of Low-Cost IoT System for Monitoring Piezometric Level and Temperature of Groundwater.

Rural communities in Mexico and other countries with limited economic resources require a low-cost measurement system for the piezometric level and temperature of groundwater for their sustainable management, since anthropogenic action (pumping extractions), natural recharge and climate change phenomena affect the behavior of piezometric levels in the aquifer and its sustainability is at risk. Decrease in the piezometric level under a balanced level promotes salt intrusion from ocean water to the aquifer, salinizing and deteriorating the water quality for agriculture and other activities; and a decrease in water level under the pumps or well drilling depth could deprive communities of water. Water temperature monitoring is essential to determine electric conductivity and dissolved salt content in groundwater. Using IoT technology, a device was developed that monitors both variables inside the well, and the ambient temperature and atmospheric pressure outside the well. The measurements are made in real time, with sampling every second and sending data to a dedicated server every 15 min so that the visualization can be accessed through a device with Internet access. The time series of the variables measured inside and outside the well were obtained over a period of three months in the rural community of Agua Blanca, Guasave, Sinaloa, Mexico. Through these records, a progressive temporary drawdown of the piezometric level is observed, as well as the frequency of pumping. This low-cost IoT system shows potential use in hydrological processes of interest such as the separation of regional and local flow, drawdown rates and recognition of geohydrological parameters.

Contact Mode Atomic Force Microscopy as a Rapid Technique for Morphological Observation and Bacterial Cell Damage Analysis.

Electron microscopy is one of the tools required to characterize cellular structures. However, the procedure is complicated and expensive due to the sample preparation for observation. Atomic force microscopy (AFM) is a very useful characterization technique due to its high resolution in three dimensions and because of the absence of any requirement for vacuum and sample conductivity. AFM can image a wide variety of samples with different topographies and different types of materials. AFM provides high-resolution 3D topography information from the angstrom level to the micron scale. Unlike traditional microscopy, AFM uses a probe to generate an image of the surface topography of a sample. In this protocol, the use of this type of microscopy is suggested for the morphological and cell damage characterization of bacteria fixed on a support. Strains of Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), and Pseudomonas hunanensis (isolated from garlic bulb samples) were used. In this work, bacterial cells were grown in specific culture media. To observe cell damage, Staphylococcus aureus and Escherichia coli were incubated with different concentrations of nanoparticles (NPs). A drop of bacterial suspension was fixed on a glass support, and images were taken with AFM at different scales. The images obtained showed the morphological characteristics of the bacteria. Further, employing AFM, it was possible to observe the damage to the cellular structure caused by the effect of NPs. Based on the images obtained, contact AFM can be used to characterize the morphology of bacterial cells fixed on a support. AFM is also a suitable tool for the investigation of the effects of NPs on bacteria. Compared to electron microscopy, AFM is an inexpensive and easy-to-use technique.

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water.

Amino acid complexes of zirconia represent an entirely new class of materials that were synthesized and studied for the first time for the decontamination of fluoride ion containing aqueous solutions. Glutamic and aspartic acid complexes of zirconia assembled with thin carbon (stacked graphene oxide) platelets deriving from graphite oxide (GO) were synthesized by a two-step method to prepare adsorbents. The characterization of the complexes was carried out using infrared spectroscopy to determine the functional groups and the types of interaction between the composites and fluoride ions. To reveal the mechanisms and extent of adsorption, two types of batch adsorption measurements were performed: (i) varying equilibrium fluoride ion concentrations to construct adsorption isotherms at pH = 7 in the absence of added electrolytes and (ii) using fixed initial fluoride ion concentrations (10 mg/L) with a variation of either the pH or the concentration of a series of salts that potentially interfere with adsorption. The experimental adsorption isotherms were fitted by three different theoretical isotherm equations, and they are described most appropriately by the two-site Langmuir model for both adsorbents. The adsorption capacities of Zr-glutamic acid-graphite oxide and Zr-aspartic acid-graphite oxide are 105.3 and 101.0 mg/g, respectively. We found that two distinct binding modes are combined in the Zr-amino acid complexes: at low solution concentrations, F- ions are preferentially adsorbed by coordinating to the surface Zr species up to a capacity of ca. 10 mg/g. At higher concentrations, however, large amounts of fluoride ions may undergo anion exchange processes and physisorption may occur on the positively charged ammonium moieties of the interfacially bound amino acid molecules. The high adsorption capacity and affinity of the studied dicarboxylate-type amino acids demonstrate that amino acid complexes of zirconia are highly variable materials for the safe and efficient capture of strong Lewis base-type ions such as fluoride.

Molecular characterization of group A rotavirus strains detected in alpacas (Vicugna pacos) from Peru.

The alpaca is a very important social and economic resource for the production of fibre and meat for Andean communities. Peru is the main producer of alpacas. Group A rotavirus (RVA) has been sporadically detected in alpacas. In this study, a total of 1423 faecal samples from alpacas from different locations of the Puno department in Peru were collected and analysed by an antigen-capture ELISA in order to detect RVA. Four per cent of the samples were RVA-positive (57/1423). The genotype constellation of three selected alpaca RVA strains were G3/8 P[1/14]-I2-R2/5-C2/3-M2/3-A17-N2/3-T6-E3-H3. Two of the analysed strains presented a bovine-like genotype constellation, whereas the third strain presented six segments belonging to the AU-1-like genogroup (G3, M3, C3, N3, T3 and E3), suggesting reassorting events. Monitoring of the sanitary health of juvenile alpacas is essential to reduce the rates of neonatal mortality and for the development of preventive health strategies.

Assessing mechanical behavior of ostrich and equine trabecular and cortical bone based on depth sensing indentation measurements.

Guided bone regeneration surgeries are based on grafting a scaffold in the site to be repaired. The main focus of the scaffold is to provide mechanical support to newly formed blood vessels and cells that will colonize the grafted site, achiving bone regenertation. In this regards, the aim of this study was to characterize the anatomy, structular, surface morphologycal, chemical composition, and nanomechanical properties of ostrich and equine trabecular bone. Ostrich and equine specimens were obtained from a local abattoir and bone was obtained by blunt dissection, n = 5. Tissue bone anatomy and trabecular structure were measured using Computerized Axial Tomography (CAT). Atomic Force Microscopy (AFM) and Energy dispersion spectrometry of X-ray (EDS) were used to examine surface morphology and chemical composition of the trabecular ostrich and equine bone. Mechanical behavior was analysted by nanoindentation. Equine specimens were examined as control. CAT results suggest that in terms of anthropometry, ostrich tarsometatarsus bone is more suitable due to its length is 432.56 ± 3.12 mm vs. the highest human bone structures reported, which femur length is 533.66 ± 18.81 mm. Besides, the low radiodensity in the Hounsfield scale exhibits equine trabecular bone more brittle (Av = 1538.4 ± 0.9) than ostrich trabecular bone (Av = 462.1 ± 1.5). EDS showed a slight variation of the element Calcium (Ca2+) ranging from 20% to 25.5% wt in equine bone; the Ca2+ content variation is consistent with the ring-shaped morphology, while in ostrich bone the chemical composition is homogeneous. The elastic modulus, nanohardness (E = 5.3 ± 0.7 GPa, H = 220 ± 10 MPa) and average roughness (Ra = 207 nm) are similar to the human trabecular bone which could reduce the stress shielding, all of these findings suggest that ostrich bone can be promising for native tissue scaffolds for mechanically demanding applications. This research makes innovative contributions to science and provides a framework, which will allow us to address future biomedical tests, and rapidly identify promising organic and sustainable waste for tissue scaffold.

Two-Step Triethylamine-Based Synthesis of MgO Nanoparticles and Their Antibacterial Effect against Pathogenic Bacteria.

Magnesium oxide nanoparticles (MgO NPs) were obtained by the calcination of precursor microparticles (PM) synthesized by a novel triethylamine-based precipitation method. Scanning electron microscopy (SEM) revealed a mean size of 120 nm for the MgO NPs. The results of the characterizations for MgO NPs support the suggestion that our material has the capacity to attack, and have an antibacterial effect against, Gram-negative and Gram-positive bacteria strains. The ability of the MgO NPs to produce reactive oxygen species (ROS), such as superoxide anion radicals (O2•-) or hydrogen peroxide (H2O2), was demonstrated by the corresponding quantitative assays. The MgO antibacterial activity was evaluated against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria, with minimum inhibitory concentrations (MICs) of 250 and 500 ppm on the microdilution assays, respectively. Structural changes in the bacteria, such as membrane collapse; surface changes, such as vesicular formation; and changes in the longitudinal and horizontal sizes, as well as the circumference, were observed using atomic force microscopy (AFM). The lipidic peroxidation of the bacterial membranes was quantified, and finally, a bactericidal mechanism for the MgO NPs was also proposed.

Síndrome hipereosinofílico con eritrodermia / Hypereosinophilic syndrome with erythrodermia

Varón de 77 años de edad, con antecedentes de insuficiencia cardiaca y fibrilación auricular recibiendo warfarina, hipotiroidismo, diabetes mellitus e hiperuricemia, con historia de un año de lesiones dérmicas eritematosas y descamativas en el tronco, pruriginosas y con moderada eosinofilia recurrente. Después de descartarse causas alérgicas, parasitarias, autoinmunes y neoplásicas, se hizo el diagnóstico de síndrome hipereosinofílico idiopático. Recibió tratamiento con prednisona e hidroxiurea, consiguiéndose una remisión completa de la eosinofilia y mejoría progresiva de las lesiones dérmicas. (AU)

A 77-year-old male, with a history of heart failure and atrial fibrillation receiving warfarin, hypothyroidism, diabetes mellitus and hyperuricaemia, with a one-year history of erythematous and desquamative skin lesions in the trunk, pruritic and moderate recurrent eosinophilia. After allergic, parasitic, autoimmune and neoplastic causes were ruled out, the diagnosis of idiopathic hypereosinophilic syndrome was done. He was treated with prednisone and hydroxyurea, resulting in complete remission of eosinophilia and progressive improvement of dermal lesions. (AU)

Properties of Mortar with Recycled Aggregates, and Polyacrylonitrile Microfibers Synthesized by Electrospinning.

Currently it is necessary to find alternatives towards a sustainable construction, in order to optimize the management of natural resources. Thus, using recycled fine aggregate (RFA) is a viable recycling option for the production of new cementitious materials. In addition, the use of polymeric microfibers would cause an increase in the properties of these materials. In this work, mortars were studied with 25% of RFA and an addition of polyacrylonitrile PAN microfibers of 0.05% in cement weight. The microfibers were obtained by the electrospinning method, which had an average diameter of 1.024 µm and were separated by means of a homogenizer to be added to the mortar. Cementing materials under study were evaluated for compressive strength, flexural strength, total porosity, effective porosity and capillary absorption, resistance to water penetration, sorptivity and carbonation. The results showed that using 25% of RFA causes decreases mechanical properties and durability, but adding PAN microfibers in 0.05% caused an increase of 2.9% and 30.8% of compressive strength and flexural strength respectively (with respect to the reference sample); a decrease in total porosity of 5.8% and effective porosity of 7.4%; and significant decreases in capillary absorption (approximately 23.3%), resistance to water penetration (25%) and carbonation (14.3% after 28 days of exposure). The results showed that the use of PAN microfibers in recycled mortars allowed it to increase the mechanical properties (because they increase the tensile strength), helped to fill pores or cavities and this causes them to be mortars with greater durability. Therefore, the use of PAN microfibers as a reinforcement in recycled cementitious materials would be a viable option to increase their applications.

Cyclo-hexane-1,4-dicarb-oxy-lic acid-pyridinium-4-olate (1/1).

In the title adduct, C5H5NO·C8H12O4, the heterocycle exists in its zwitterionic form. The cyclo-hexane ring exhibits a chair conformation with the carb-oxy-lic acid groups in equatorial and axial orientations. In the crystal, mol-ecules are linked through charge-assisted O-H⋯O(-), N(+)-H⋯O(-) and N(+)-H⋯O hydrogen bonds, and an additional series of C-H⋯O contacts, giving a pleated two-dimensional hydrogen-bonded network parallel to (-204).

Estudio clínico epidemiológico de las aguas de consumo humano de la Villa de Cofradía Cortés y su influencia en la población / Clinic epidemiological survey of human water consumption the Villa of Cofradia, Cortes Honduras and its population influence

ANTECEDENTES. El sistema de abastecimiento de aguas para consumo humano en la Villa de Cofradía está constituido por dos fuentes: Río Manchaguala y Río Negro. En los últimos años se produjeron múltiples denuncias de sus pobladores relacionando sus enfermedades dermatológicas y gastrointestinales con el agua de consumo. OBJETIVO. Describir las condiciones clínicas y epidemiológicas en una muestra de pobladores de la Villa de Cofradía y su asociación con el agua que consumen. MÉTODOS. Durante enero y febrero del 2003 se estudiaron 79 individuos (39 mujeres y 40 hombres) que representaban el 72% de un total de 110 pacientes que acudieron al Centro de Salud de la comunidad aduciendo que su sintomatología dermatológica y gastrointestinal era causada por el agua que consumían. Se midieron niveles séricos de metales pesados y se realizó medición de metales pesados y bacterías en agua potable. RESULTADOS. El 90% de los pacientes adolecía de enfermedades de origen infeccioso (escabiosis, micosis,abscesos, impétigos, varicela, SIDA, etc.) y el resto de otro origen (psoriasis, urticaria, prurigo, úlceras varicosas,etc.). De 6 pacientes con enfermedades diarreicas, 4 tenían uno o más helmintos y/o protozoarios intestinales.Se determinaron niveles séricos detectables de níquel (11 pacientes), cromo (9) y cadmio (2). El análisis físico-químico del agua reveló niveles elevados de hierro, níquel, cromo, cadmio, aluminio y plomo sobrepasando el máximo permitido para agua potable.En ninguna muestra se encontró niveles de coliformes fecales que sobrepasaran la norma permitida. CONCLUSIONES.Un sector de esta población sufre de problemas dermatológicas, gastrointestinales de tipo infecto-contagiosas que no precisamente están relacionadas con el agua que consumen, sino a condiciones socioeconómicas y culturales. Aunque los pacientes a quienes se les encontraron niveles séricos aumentados de algunos metales pesados no presentaban manifestaciones clínicas...

Traumatismo penetrante de cráneo / Penetrating head stab injury

Introducción. El traumatismo craneoencefálico es una entidad común en el departamento de urgencias y se ha vuelto un problema de salud pública. El trauma penetrante de cráneo (TPC) ocupa un lugar especial por su rareza. En un sentido general el TPC es definido como "cualquier daño físico o inapropiada funcionalidad del contenido craneal por un intercambio mecánico de energía". Caso clínico. Se presenta el caso de un lactante mayor que sufrió un TPC por arma blanca mientras dormía, al caer accidentalmente sobre un cuchillo sostenido en posición vertical dentro de un vaso al pie de la cama; fue sometido a extracción de la misma en quirófano y cuya evolución y pronóstico fueron favorables. Conclusiones. Se ofrecen algunas indicaciones de manejo y se enfatiza sobre la implementación de medidas de seguridad en el hogar y de que todo niño deberá de ser vigilado estrechamente aunque duerma plácidamente.

Introduction. Acute head trauma is a common presentation to the pediatric emergency department. Penetrating head trauma (PHT) represents a small fraction of this group.The PHT can be defined as "any physical damage to, or functional impairment, of the cranial contents by acute mechanical energy exchange". Case report. This is the case of a 1 year old male boy, who suffered accidental PHT with a knife, when he fell down from his bed.The extraction of the knife was carried out in the operating room without any complications and with satisfactory outcome. Conclusions. We offer some clues of management and emphasize about the implementation of household safety rules, even when a child is sleeping.