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Nanomaterials are widely employed in wastewater treatment, among which nanoferrites and their composites hold significant prominence. This study adopts a green approach to synthesize zinc ferrite nanoparticles, subsequently integrating them with polyaniline (PANI) to fabricate the ZnFe2O4-PANI nanocomposite. Characterization of the prepared ZnFe2O4-PANI nanocomposite was conducted using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. Using Scherrer's equation, the crystallite size of the synthesized zinc ferrite nanoparticles was found to be 17.67 nm. SEM micrographs of the ZnFe2O4-PANI nanocomposite revealed that in situ polymerization of ZnFe2O4 with polyaniline transforms the amorphous surface morphology of the polymer into a homogeneous nanoparticle structure. The adsorption of crystal violet (CV) dye onto the surface of the ZnFe2O4-PANI nanocomposite depends on pH, adsorbent dosage, temperature, concentration levels and duration. The Langmuir adsorption model fitted the data well, indicating adherence to a pseudo-second-order kinetic pattern. Thermodynamic values ΔG°, ΔH° and ΔS° indicated that the adsorption process occurred spontaneously. Advantages and disadvantages of the technique have also been highlighted. Mechanism of adsorption is discussed. From the obtained results, it is evident that the ZnFe2O4-PANI nanocomposite holds promise as a sorbent for the removal of dye from wastewater.
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Compuestos de Anilina , Compuestos Férricos , Violeta de Genciana , Nanocompuestos , Contaminantes Químicos del Agua , Zinc , Compuestos de Anilina/química , Violeta de Genciana/química , Nanocompuestos/química , Contaminantes Químicos del Agua/química , Compuestos Férricos/química , Zinc/química , Adsorción , Eliminación de Residuos Líquidos/métodos , Cinética , Purificación del Agua/métodosRESUMEN
The presence of heavy metal in soil and water resources has serious impact on human health. The study was designed to examine the phytoremediation ability of plant species that are growing naturally on the Zn-contaminated site. For the study, six plant species and their rhizospheric soil as well as non-rhizospheric soil samples were collected from different parts of the industrial sites for chemical and biological characterization. Visual observations and highest importance value index (IVI) through biodiversity study revealed potential plants as effective ecological tools for the restoration of the contaminated site. Among the plants, almost all were the most efficient in accumulating Fe, Mn, Cu and Zn in its shoots and roots, while Cynodon dactylon, Chloris virgata and Desmostachya bipinnata were found to be stabilizing Cr, Pb and Cd (bioconcentration factor in root = 7.95, 6.28 and 1.98 as well as translocation factor = 0.48, 0.46 and 0.78), respectively. Thus, the results of this study showed that the naturally growing plant species have phytoremediation potential to remediate the electroplating wastewater-contaminated site. These plant species are successful phytoremediators with their efficient metal stabilizing and well-evolved tolerance to heavy metal toxicity.
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Galvanoplastia , Metales Pesados/metabolismo , Plantas/metabolismo , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/metabolismo , Biodegradación Ambiental , Biodiversidad , Metales Pesados/análisis , Raíces de Plantas/clasificación , Raíces de Plantas/metabolismo , Plantas/clasificación , Rizosfera , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo , Contaminantes Químicos del Agua/análisisRESUMEN
Cerium oxide nanoparticles (nanoceria) were synthesized by a novel, simple green chemistry procedure using Elaeagnus angustifolia leaf extract as a reducing and capping agent. The crystalline nature of nanoceria was confirmed by XRD analysis. FTIR analysis revealed that phytochemicals are present on the surface of nanoceria. SEM and TEM images revealed that the nanoceria are well dispersed, spherical in shape with a particle size range in between 30 and 75â¯nm. Thereafter, the effects of various concentrations of cerium oxide (CeO2) and green synthesized nanoceria on growth and metabolism of Solanum lycopersicum (tomato) were investigated. The bio-accumulation of Ce in tomato seedlings was found to be dose dependent and the results showed that with the increase in exposure concentrations, the accumulation of Ce contents in both root and shoots augmented. However, unlike nanoceria treated seedlings, Ce contents in the roots with CeO2 treatments were negligible than that in the shoots at lower concentrations and this suggested the immobilization of Ce in CeO2 treatment at lower concentrations. Nanoceria at 500 and 1000â¯mg/L resulted in inhibitory effect on growth of test plant as compared to CeO2 component. The exposure of plants to nanoceria and CeO2 has resulted in significant reduction in pigment content, increased LP, EL and H2O2 content. The activities of antioxidant enzymes viz. SOD, CAT, APX and GPX were significantly up regulated on exposure of nanoceria and CeO2. It is concluded that plant exposure with nanoceria at concentrations of 20 and 100â¯mg/L were more beneficial for growth and metabolism of tomato plants than that of CeO2 at equivalent concentrations.
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Antioxidantes/metabolismo , Cerio/farmacología , Tecnología Química Verde/métodos , Nanopartículas/química , Solanum lycopersicum/efectos de los fármacos , Solanum lycopersicum/enzimología , Transporte Biológico , Cerio/química , Cerio/metabolismo , Elaeagnaceae/química , Peróxido de Hidrógeno/metabolismo , Tamaño de la Partícula , Extractos Vegetales/químicaRESUMEN
Disposal of red mud (RM) poses serious environmental problems such as wind erosion, air and water pollution. To overcome these problems, effective restoration of the disposal land through naturally growing vegetation is a sustainable and economical approach. The present study involved estimation of frequency (F), density (D), abundance (Ab), and important value index (IVI) of natural flora on abandoned RM sites in order to assess their metal toxicity tolerance capacity. Based on visual observations and highest IVI, S. Asper and S. punicea were identified as effective ecological tools for the restoration of barren RM sites. From the study, remarkable differences were observed between non-rhizospheric and rhizospheric RM of both species. These rhizospheric RM analyses confirm the ability of S. asper and S. punicea for enhancing the biological activities of abandoned RM. Translocation factor (TF) of iron was maximum (2.58) in S. asper, and bioconcentration factor (BCF) was found maximum (1.25) in S. punicea, but both TF (2.58) and BCF (1.35) were high in S. asper. Therefore, this plant could be reported as an iron hyperaccumulator plant. These results suggest that these plant species can be exploited for effective restoration of RM deposited land without any inputs or maintenance.
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Restauración y Remediación Ambiental , Metales Pesados/metabolismo , Sesbania/metabolismo , Contaminantes del Suelo/metabolismo , Sonchus/metabolismo , Biodegradación Ambiental , India , Residuos Industriales/análisis , Minería , Sesbania/química , Sesbania/enzimología , Sesbania/microbiología , Suelo/química , Sonchus/química , Sonchus/enzimología , Sonchus/microbiologíaRESUMEN
Nanotechnology is a new and emerging technology with wealth of applications. It involves the synthesis and application of materials having one of the dimensions in the range of 1-100 nm. A wide variety of physico-chemical approaches are being used these days for the synthesis of nanoparticles (NPs). However, biogenic reduction of metal precursors to produce corresponding NPs is eco-friendly, less expensive, free of chemical contaminants for medical and biological applications where purity of NPs is of major concern. Biogenic reduction is a "Bottom Up" approach similar to chemical reduction where a reducing agent is replaced by extract of a natural products with inherent stabilizing, growth terminating and capping properties. Furthermore, the nature of biological entities in different concentrations in combination with reducing organic agents influence the size and shape of NPs. Present review focuses on microbes or plants based green synthesis of Ag, Au, Cu, Fe, Pd, Ru, PbS, CdS, CuO, CeO2, Fe3O4, TiO2, and ZnO NPs and their potential applications.
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Tecnología Química Verde/métodos , Nanopartículas del Metal/química , Nanotecnología/métodos , Extractos Vegetales/química , SemiconductoresRESUMEN
Genetic variability studies for needle and wood traits were carried out for the different half sib progenies of Chir pine, raised in 1985 at the main campus of University. There existed a significant variation for these traits among the different half sib progenies, viz., needle length (18.1-24.6 cm), needle thickness (0.53-0.71 mm), number of stomata per mm of a row (7.3-12.0), specific gravity of wood (0.36-0.46), tracheid length (1.51-1.85) and moisture content of wood (47.76-58.81). This variability was found under genetic control, as all these progenies are growing under same environment, and are of same age. Traits having high heritability and genetic gain like, needle thickness, wood specific gravity, tracheid length and others, indicate high genetic control. This variability can be exploited in tree improvement programs through selection and breeding approaches for development of advanced generations. Correlation studies for different traits at genotypic and phenotypic levels provided the basic knowledge of association to chalk out efficient breeding strategy for higher productivity through indirect selection.
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First principle calculations with generalized gradient approximation were carried out to analyse the electronic and optical properties of armchair and zigzag graphyne nanotubes (GNTs). The possible application of these NTs in optoelectronic devices was also investigated. The GNTs were doped with boron (B) and nitrogen (N) atoms and the resulting band gap tuning was studied with respect to the B/N substitution site and increasing diameter of the NTs. The basis of this variation was examined using the partial density of states and crystal orbital Hamilton population analysis. A decreasing trend in the optical response was seen with an increase in the diameter of the NTs. The reported systems showed anisotropic behaviour in the low-energy region. The origin of the optical responses was monitored from the infrared to the UV region depending on the doping site of the B/N. As a result of the large band gap, low reflectivity and low refractive index, B/N GNTs have been established as a suitable system for novel optoelectronic devices. The strong absorption peaks in the UV region mean that they are a good choice for use in UV light protection.
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The implication of molecular biology in crop improvement is now more than three decades old. Not surprisingly, technology has moved on, and there are a number of new techniques that may or may not come under the genetically modified (GM) banner and, therefore, GM regulations. In cisgenic technology, cisgenes from crossable plants are used and it is a single procedure of gene introduction whereby the problem of linkage drag of other genes is overcome. The gene used in cisgenic approach is similar compared with classical breeding and cisgenic plant should be treated equally as classically bred plant and differently from transgenic plants. Therefore, it offers a sturdy reference to treat cisgenic plants similarly as classically bred plants, by exemption of cisgenesis from the current GMO legislations. This review covers the implications of cisgenesis towards the sustainable development in the genetic improvement of crops and considers the prospects for the technology.
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BACKGROUND: Water pollution is one of the important causes of human fatality in the world, particularly in underdeveloped or developing countries. Moreover, with rapid industrialization and urbanization, the problem of water pollution is posing a severe threat to health and livelihood. The pollutants found in water are of varied nature and depend on the source of the water. Several techniques have so far been adopted to purify contaminated water. All the techniques have one or the other disadvantages, limiting their applications on large scale, sustainability, and long-term usage. The advances in the field of nanoscience and technology have opened a new horizon for replacement/improvement of conventional ways with more efficient methods. Presently, green synthesized nanomaterials are being used for water purification. METHODS: Plant extracts and microbes are being used to synthesize nanomaterials, which are used as catalysts, adsorbents and membranes for water purification. RESULTS: Nanomaterial-based techniques could create problems for the environment due to various chemicals used in their production step, thus defeating the ultimate purpose. In this regard, green nanomaterials can prove to be extremely useful both in terms of sustainability and efficiency. CONCLUSION: This review illustrates various ways of how green nanomaterials can be utilized for water remediation and summarizes the recent work done in this emerging research area.
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Contaminantes Ambientales , Nanoestructuras , Purificación del Agua , Humanos , Aguas Residuales , Purificación del Agua/métodos , Agua , AdsorciónRESUMEN
Beginning of industrialization accelerates the heavy metal pollution in the biosphere. Plant being the immovable entity utilizes different mechanisms to flee from unfavourable conditions. To alleviate toxic impact of metals like cadmium (Cd) and lead (Pb), phytohormones such as indole acetic acid (IAA) has been applied exogenously. This manuscript aims to evaluate the significant change occurring in biochemical parameters of Indian mustard (Brassica napus) grown under individual and combined treatments of IAA with Cd and Pb. Herbicidal potential of treated Brassica extracts were evaluated on growth and development of Anagallis arvensis. Quantum yield parameters were more sensitive to Cd than Pb stress resulted in reduced photosynthetic pigments. However, exogenously applied IAA together with Cd and Pb considerably improved the level of photosynthetic attributes along with reduced accumulation of Cd and Pb in Brassica plant. Cd and Pb enhanced the activities of reactive oxygen species (ROS) and antioxidant machinery. However, addition of IAA with Cd and Pb mitigated the effect of heavy metals on antioxidant system. Moreover, activity of the phenylalanine ammonia lyase enzyme and the defensive metabolites (phenolic, flavonoid and anthocyanin compounds) were boosted under individual treatments of Cd and Pb responsible for increasing herbicidal potential of Brassica plant. Our results exhibited essentiality of IAA in mitigating Cd and Pb stress in Brassica through up-regulated mechanisms of the antioxidant system for balancing ROS related injuries. Increased metabolites enhancing herbicidal potential of Brassica napus against Anagallis weed were also observed.
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Anagallis/crecimiento & desarrollo , Brassica napus , Herbicidas , Contaminantes del Suelo , Brassica napus/metabolismo , Cadmio/toxicidad , Ácidos Indolacéticos , Plomo/toxicidad , Fitoquímicos , Malezas/crecimiento & desarrollo , Contaminantes del Suelo/toxicidadRESUMEN
The present work describes the bio-based green synthesis and characterization of zinc oxide nanoparticles (ZnO NPs) using leaf extract of Tridax procumbens; the synthesized nanoparticles were used to study their beneficial effect on the growth and metabolism of Vigna radiata. ZnO NPs were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and ultraviolet-visible spectroscopy (UV-Vis spectra). Growth of V. radiata seedlings was measured in terms of shoot length and root length that were treated 20 and 40 mg/L concentrations of green synthesized ZnO NPs and constant concentration (50 mg/L) of PbCl2. These studies have shown the effect of ZnO NPs in the stimulation of growth as well as physiological and biochemical parameters. Vigna seedlings showed positive effects depending upon the increasing concentrations of ZnO NPs. This study suggests that ZnO NPs can be effectively used to ameliorate the toxicity of Pb in Vigna plants.
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Nanopartículas del Metal , Vigna , Óxido de Zinc , Antibacterianos/química , Tecnología Química Verde , Nanopartículas del Metal/química , Nanopartículas del Metal/toxicidad , Pruebas de Sensibilidad Microbiana , Óxidos , Extractos Vegetales/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , Óxido de Zinc/química , Óxido de Zinc/toxicidadRESUMEN
It is an age of nanomaterials. Nanotechnology has revolutionized the scientific world. Every sphere of technology has benefited significantly by using nanomaterials. A number of physical and chemical methods are being used for the synthesis of nanomaterials. In recent years, much emphasis is placed on green synthesis, particularly by using plant extracts or microorganisms. This is useful for promoting environmental sustainability. Microwave heating and ultrasound techniques are also being used for the synthesis of different types of nanomaterials. Green synthesis is a more advanced method of synthesizing nanomaterials over other methods because of its simplicity, lower cost, and relatively higher reproducibility. Plants produce more stable nanoparticles compared to other means, and it is straightforward to scale up. The risk of contamination is also lower. In this article, different methods of green synthesis of nanomaterials and applications have been reviewed and discussed.
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Nanopartículas , Nanoestructuras , Nanotecnología , Plantas , Reproducibilidad de los ResultadosRESUMEN
This data article deals with the assessment of groundwater quality based on water quality index (WQI) and irrigation indices. A total of 8 sites have been selected for the qualification of groundwater fitness. The assessment of groundwater quality has been done by selecting 13 physico-chemical parameters such as pH, EC, TDS, Ca2+, Mg2+, Na+, K+, Cl-, SO4-, HCO3-, NO3-, F-, and TH. Inverse distance-weighted (IDW) application was used to prepare the spatial distribution maps of WQI for the pre and post-monsoon period. All the samples were found in the rock dominance zone in Gibbs plot and according to the Piper plot, Ca-HCO3 is the dominant hydrochemical facies in the study area. On the other hand, irrigation water quality was examined by computing irrigation indices such as SAR, RSC, SSP, MHR, KR, %Na, PI, and PS. The outcomes of the irrigation indices suggests that the water quality is of a good and excellent category except for MHR and RSC.
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BACKGROUND: For developing countries with a large number of cases and financial constraints, evaluation of rapid and inexpensive diagnostic methods has great importance. The bacilli in the sputum can be detected microscopically by ZN stain and fluorochrome stain. OBJECTIVES: To study the efficacy of fluorescence microscopy in the diagnosis of pulmonary tuberculosis in comparison to Ziehl-Neelsen staining and culture of sputum samples from patients suspected of pulmonary tuberculosis. MATERIALS AND METHODS: 306 sputum samples collected from 102 patients suspected of pulmonary tuberculosis were processed by the Petroff's method, and subjected to Ziehl-Neelsen staining (ZN), fluorescent Auramine-O staining (AO) and culture on modified Lowenstein-Jensen media (gold standard) for detection of Mycobacterium tuberculosis. Positive smears were graded according to Forbes BA et al, and culture isolates were biochemically tested for confirmation of species. RESULTS: Out of 102 patients, 44.1%, 71.6% and 70% were found positive by ZN, AO and culture respectively. AO was found to be superior to ZN on several aspects. The difference in their case detection rates was statistically significant (chi(2) = 24.93, p < 0.001). AO was also able to detect more pauci-bacillary cases than ZN. There was more agreement between culture and fluorescence microscopy (95.1%) than with ZN microscopy (69.6%). The percentage of false negative by AO staining was only 2.78% which was in sharp contrast to that of ZN (40.27%). CONCLUSION: The better case detection rates of AO over ZN were comparable to those found by several studies. Since screening was done under lower power of magnification (400x), fluorescence microscopy has been found to be less time consuming as compared to ZN method (1000x) in the diagnosis of tuberculosis. The tubercle bacilli stood out as bright objects against a dark background in fluorescence microscopy which makes them easily identifiable hence causing less eye-strain. The efficacy of fluorescence microscopy proved to be much higher than conventional light microscopy and comparable to that of culture.
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Microscopía Fluorescente/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Esputo/microbiología , Coloración y Etiquetado/métodos , Tuberculosis Pulmonar/diagnóstico , Células Cultivadas , Diagnóstico Diferencial , Humanos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Esputo/citología , Tuberculosis Pulmonar/microbiologíaRESUMEN
Study on the ecological effect of metal oxide nanomaterials (NMs) has quickly amplified over the precedent years because it is assumed that these NMs will sooner or later be released into the environment. The present study deals with biologically oriented process for the green synthesis of copper oxide nanoparticles (CuO NPs) by using Morus alba leaf extract as reducing agent. Powder X-ray diffraction (XRD) and transmission electron microscope (TEM) analysis revealed the monoclinic phase and 20-40nm size respectively. The presence of reducing and capping agents revealed by Fourier transform infrared (FTIR) spectroscopy. The seedlings of Brassica oleracea var. botrytis and Solanum lycopersicum were exposed to 10, 50, 100, and 500mgL-1 concentrations of CuO NPs in the sand medium. Bioaccumulation of Cu was also investigated by atomic absorption spectroscopy (AAS). Plant exposure to 100 and 500mgL-1 of CuO NPs has resulted in significant reduction of total chlorophyll and sugar content in the two test plants while 10mgL-1 of NPs slightly increased the pigment and sugar content in tomato plants only. Augmentation of lipid peroxidation, electrolyte leakage, and antioxidant enzyme activity was observed in a dose dependent manner upon plants exposure to CuO NPs. Deposition of lignin in roots of both plants treated with the highest concentration of CuO NPs was observed. Histochemical analysis of leaves of treated plant with nitroblue tetrazolium and 3'3' diaminobenzidine showed a concentration dependent increase in superoxide and hydrogen peroxide formation in leaves. The green synthesis of CuO NPs was carried out by using Morus alba leaf extract. Accumulation of NPs more actively by tomato plants as compared to cauliflower was possibly due to the difference in root morphology. The histochemical visualization highlights the spatial organization of oxidant biochemistry occurring in response to metal stress.
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Brassica/efectos de los fármacos , Cobre/metabolismo , Nanopartículas del Metal/química , Solanum lycopersicum/efectos de los fármacos , Antioxidantes , Brassica/crecimiento & desarrollo , Catalasa/análisis , Clorofila/análisis , Cobre/análisis , Cobre/química , Cobre/farmacología , Electrólitos , Tecnología Química Verde/métodos , Peroxidación de Lípido , Solanum lycopersicum/crecimiento & desarrollo , Microscopía Electrónica de Transmisión , Morus/química , Nitrato-Reductasa/metabolismo , Fotosíntesis , Extractos Vegetales/química , Hojas de la Planta/efectos de los fármacos , Raíces de Plantas/citología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Plantones , Espectroscopía Infrarroja por Transformada de Fourier , Azúcares/análisis , Superóxido Dismutasa/análisis , Superóxidos , Difracción de Rayos XRESUMEN
In the present study, we compared the effects of Al3+ ions and alumina (Al2O3) nanoparticles (NPs) on growth and biochemical parameters of cabbage seedlings. The seedlings were treated with A=698.8µM Al3+ions and A1=101.8µM, A2=253.8µM, A3=507.7µM, A4=1.02mM, A5=2.17mM NPs of Al2O3 in 700mL Hoagland solution. The untreated seedlings were taken as control. It was observed that aluminium ions were phytotoxic and adversely affected seedling growth and biochemical parameters of the test crop with stunting of the stem growth, while lower doses of alumina NPs enhanced seedling growth, pigments, sugar and protein contents of cabbage (Brassica oleracea var. capitata) seedlings. Higher doses of alumina NPs adversely affected biochemical parameters and nitrate reductase activities of the treated seedlings. Alumina NPs induced activities of antioxidant enzymes viz. SOD, CAT and POX. Antioxidant enzyme activities increased under all treatments with maximum increase in the seedlings treated with aluminium ions and higher concentrations of alumina NPs. The lower amount of alumina NPs buttressed the metabolic processes of the test crop and appeared to mitigate the phytotoxic effects of aluminium ions.
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Antioxidantes/farmacología , Brassica/crecimiento & desarrollo , Nanopartículas del Metal/química , Plantones/crecimiento & desarrollo , Óxido de Aluminio/química , Óxido de Aluminio/farmacología , Antioxidantes/química , Brassica/efectos de los fármacos , Brassica/metabolismo , Catalasa/metabolismo , Iones/farmacología , Plantones/efectos de los fármacos , Plantones/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
In the present study, zinc oxide nanoparticles (ZnO NPs) were rapidly synthesized at room temperature by treating zinc acetate dihydrate with the flower extract of Elaeagnus angustifolia (Russian olive). The formation of ZnO NPs was primarily confirmed by UV-visible absorption spectrum in the range of 250-700nm. XRD analysis and DLS particle size analyzer revealed the size of ZnO NPs. The FTIR spectrum revealed the presence of phytochemicals in the flower extract mediated ZnO NPs. Moreover, the morphology of the ZnO NPs was determined using SEM. Seeds of Solanum lycopersicum (tomato) were separately treated with different concentrations of synthesized ZnO NPs and zinc sulphate (ZnSO4) salt suspensions (common zinc supplement). The effect of these treatments on seed germination, seedling vigor, chlorophyll, protein and sugar contents as well as on the activities of lipid peroxidation and antioxidant enzyme were studied. Leaves of plants treated with 6.1mM concentration of ZnO NPs recorded maximum reflectance while it was minimum in plants treated with 1.2mM concentration of NPs. The effect of synthesized ZnO NPs on seedling vigor, pigment, protein and sugar content was found affirmative at lower concentrations contrary to control and ZnSO4 salt. The inhibitory effect at higher concentration of NPs indicated importance in the precise application of NPs, in Zn deficient system, where plant response varies with concentration. To the best of our knowledge this is the first report on Elaeagnus angustifolia mediated synthesis of ZnO NPs and their effects on germination and physiological activity of tomato.
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Germinación/efectos de los fármacos , Nanopartículas del Metal/química , Extractos Vegetales/química , Solanum lycopersicum/efectos de los fármacos , Óxido de Zinc/química , Elaeagnaceae/química , Flores/química , Tecnología Química Verde , Solanum lycopersicum/metabolismo , Nanopartículas del Metal/toxicidad , Hojas de la Planta/química , Semillas/efectos de los fármacos , Óxido de Zinc/metabolismoRESUMEN
Neuromotor processes are inherently noisy, which results in variability during movement and fluctuations in motor control. Although controversial, low levels of variability are traditionally considered healthy, while increased levels are thought to be pathological. This systematic review and meta-analysis of the literature investigates the thresholds between healthy and pathological task variability. After examining 13,195 publications, 109 studies were included. Results from over 3000 healthy subjects and 2775 patients revealed an overall positive effect size of pathology on variability of 0.59 for walking and 0.80 for sway. For the coefficient of variation of stride time (ST) and sway area (SA), upper thresholds of 2.6% and 265mm(2) discriminated pathological from asymptomatic performance, while 1.1% and 62mm(2) identified the lower thresholds for pathological variability. This window of healthy performance now provides science based evidence for the discrimination of both extremely low and extremely high levels of variability in the identification as well as standardised monitoring of functional status in neurological cases.
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Postura , Caminata , Marcha , Humanos , Equilibrio PosturalRESUMEN
Geopolymer concrete mixes were cast using fly ash, kaolin, sodium hydroxide, potassium hydroxide, sodium silicate and aggregates. Portland cement concrete (M30) was used as a reference sample. The effect of silica fume, temperature (40 °C, 60 °C, 80 °C, 100 °C and 120 °C), sodium and potassium hydroxides and different superplasticizers on the compressive strength are reported [1]. Maximum strength was found at 100 °C and 14 M alkali solution [1].