One of the main issues in the medical field and clinical practice is the development of novel and effective treatments against infections caused by antibiotic-resistant bacteria. One avenue that has ...been approached to develop effective antimicrobials is the use of silver nanoparticles (Ag-NPs), since they have been found to exhibit an efficient and wide spectrum of antimicrobial properties. Among the main drawbacks of using Ag-NPs are their potential cytotoxicity against eukaryotic cells and the latent environmental toxicity of their synthesis methods. Therefore, diverse green synthesis methods, which involve the use of environmentally friendly plant extracts as reductive and capping agents, have become attractive to synthesize Ag-NPs that exhibit antimicrobial effects against resistant bacteria at concentrations below toxicity thresholds for eukaryotic cells.
In this study, we report a green one-pot synthesis method that uses
extract as a reducing and capping agent, to produce Ag-NPs with applications as therapeutic agents to treat infections in vivo.
The Ag-NPs were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive spectroscopy, ultraviolet-visible, and Fourier transform infrared.
We show that Ag-NPs are spherical with a narrow size distribution. The Ag-NPs show antimicrobial activities in vitro against Gram-negative (
,
, and a clinical multidrug-resistant strain of
) and Gram-positive (
) bacteria. Moreover, antimicrobial effects of the Ag-NPs, against a resistant
clinical strain, were tested in a murine skin infection model. The results demonstrate that the Ag-NPs reported in this work are capable of eradicating pathogenic resistant bacteria in an infection in vivo. In addition, skin, liver, and kidney damage profiles were monitored in the murine infection model, and the results demonstrate that Ag-NPs can be used safely as therapeutic agents in animal models.
Together, these results suggest the potential use of Ag-NPs, synthesized by green chemistry methods, as therapeutic agents against infections caused by resistant and nonresistant strains.
•Ce-doped HfO2 nanoparticles were prepared by a modified solgel method.•Ce-doped HfO2 nanoparticles have a semispherical shape with sizes between 6 and 11.5nm.•The samples doped with 10% in weight of ...Ce directly crystallized in a cubic structure.•A quick, straightforward and effective route for the preparation of Ce-doped nanoparticles.
A modified solgel method to synthesize Ce-doped HfO2 nanoparticles was carried out using a precursor material prepared with cerium nitrate, hafnium chloride, citric acid and ethylene glycol. The obtained precursor material was calcined at 500 and 700°C for 2h in air. The influence of the concentration of Ce and the calcination temperature was studied to observe the structural and morphological changes of the obtained materials. For the characterization, X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman scattering (RS) were employed. The XRD patterns shown that the Ce-doped HfO2 undergoes a structural transformation from monoclinic to cubic phase, which is significantly dependent on the Ce content and calcination temperature. TEM images have also confirmed the existence of semispherical nanoparticles with sizes between 6 and 11.5nm.
Micrometer-sized composite polymer-magnetic spheres consisting of a magnetic-spherical core with a polystyrene shell were produced. The magnetic-spherical core was produced by plasma thermal ...conversion of waste powders precursor (iron oxide) generated during the conventional process of steel production. Precursor powders were projected into an Ar-He plasma plume using industrial thermal-spray equipment. The results are a total conversion of the precursor powders into magnetic-spherical particles with diameters in the micrometer size range. The surfaces of the magnetic-spheres were functionalized by a chemistry hydrolysis method using 3-aminopropyltrimethoxysilane (APTMS) and creating superficial amine structures that improved the adherence of the final polystyrene shells that was polymerized by adapting the miniemulsion process. The products at the different synthesis steps were characterized by diverse techniques, such as: X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), X-ray energy dispersive spectroscopy (EDS), Fourier Transformed Infrared spectroscopy (FTIR) and the magnetic properties were investigated with a vibrating sample magnetometer.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Blast furnace slags (BFS) were transformed into glass porous spheres by applying a natural gas/oxygen thermal projection process. Three types of BFS were selected as a function of their age or ...storage time. Effect of type of precursor, as well as gases mixture, feeding distance and feeding rate on density, morphology, microstructure and particles size of generated spheres were evaluated. It was found that despite of the slag age, obtained spheres are completely amorphous, and that the feeding distance has an important effect on spheres densities. Optimum treatment conditions were established in order to generate glass porous spheres with lower densities than their precursors.
This work reports the formation of α-alumina from pseudoboehmite synthesized from three different hydrated inorganic aluminum salts such as aluminum nitrate, aluminum chloride and aluminum sulfate ...using the sol–gel method in aqueous medium at 80 °C. All the aluminum hydroxides were thermally treated and all showed similar crystalline conversion behavior; and, their solid-phase transformations to aluminum oxides were investigated. Following the synthesis, all products were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry–thermogravimetric analysis and X-ray diffraction. The hydrolysis products were calcined at 200, 300, 600, 800, 1100 and 1200 °C for 1-h. The eta (η) and theta (θ) transitional aluminas were detected until complete transformation to highly crystalline α-alumina occurred at ~1200 °C. Moreover, starting at 1100 °C the sample derived from the sulfate salt showed intense crystalline peaks corresponding to α-alumina. The morphological study for the samples of α-alumina calcined at 1200 °C was carried out by field emission scanning electron microscopy where a vermicular structure was observed. These α-alumina samples were also analyzed by high resolution-transmission electron microscopy. In addition, fast Fourier transform and selected area electron diffraction patterns of α-alumina samples calcined at the highest temperature were obtained to calculate the experimental interplanar distances whose values were compared to reported theoretical values.
The accidental ingestion of Karwinskia humboldtiana (Kh) fruit in humans and animals causes chronic or acute intoxication. Acute poisoning induces respiratory failure that progresses rapidly to ...death. Studies in animals intoxicated with Kh describe lesions in cerebral cortex, cerebellum, spinal cord, hippocampus and caudate nucleus. Kh intoxication in Wistar rats models the sub-lethal clinical phase observed in humans. Considering these reports, the present study analyzed the histopathological alterations within the striatum following experimental Kh intoxication. Twenty Wistar rats were divided into three groups (n =5) and were intoxicated with Kh fruit. A control group (n =5) was included. Animals were euthanized at several time points (48, 58 and 170 days post-intoxication). The brain was collected, divided and processed for conventional histology or electron microscopy. Sections were stained with hematoxylin and eosin, cresyl violet, Klüver-Barrera, and toluidine blue. Immunolabeling was performed for glial cells in the striatum, and the samples were analyzed with light microscopy. Morphometric and statistical analyses were performed. In control group, neurons, axon bundles and neuropil had a normal appearance. At 48 days, hyperchromic neurons with apparent decreased size were observed interspersed among the normal neurons. At 58 days, we observed an increased number of hyperchromic neurons and disorganization of the myelin sheath and neuropil. At 170 days, these alterations persisted in the paralysis group. In treated groups, we observed signs of gliosis and increased axonal diameters. This study is the first report that describes the histopathological alterations within the striatum caused by chronic intoxication with Kh fruit in the Wistar rat.
A novel production of new aggregate for mortars based on glass-ceramic porous spherical particles into SiO2-CaO-Al2O3-MgO quaternary system is reported. Crystalline blast furnace slags (c-BFS) are ...transformed into new glass-ceramic porous spherical materials with lower density than their precursor. The conversion occurs by c-BFS projection into an oxygen/Liquefied Petroleum Gas (LPG) plume-flame. The aim of the present work is to evaluate these new materials as aggregates to replace the sand in conventional mortars formulations in order to indicate a potential way to reduce the use of this mineral resource and also how industrial wastes can be transformed in useful materials with direct application into the construction materials field. The characterization of the precursor and products were carried out by optical microscopy; scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and their densities were measured by Helium pycnometry. Additionally, the compressive strengths at different aging times (7, 14 and 28 days), from a control sample and diverse mortars based on glass-ceramic porous spherical particles were evaluated. Finally, thermal conductivities from all the specimens cured at 28 days were also measured.
Karwinskia humboldtiana fruit (Kh) causes a neurological disorder 3–4 weeks after ingestion, characterized by flaccid, symmetrical, ascending paralysis, similar to the Guillain–Barre syndrome. In ...this polyneuropathy the lesion (demyelization) in peripheral nerves has been described in several animal species, both in acute and in chronic intoxication. However, no reports exist about the presence of lesions in the Central Nervous System (CNS), in chronic intoxication. We considered it important to evaluate, with histological techniques, the possible presence of lesions in the brain, by using a model of chronic intoxication that reproduces the same stages present in the human intoxication, to better understanding of this pathological process. In our present work we fed the ground Kh fruit to Wistar rats and samples of brain, cerebellum, and pons were embedded in paraffin. Sections were stained with Hematoxylin & Eosin (HE) and special stains for nerve tissue. Histopathological changes were evaluated in the CNS through the different stages of the polyneuropathy and comparison to a control group.
With this methodology, we found lesions in the motor pathway. This is the first report about the presence of neuronal damage caused by Kh in the Central Nervous System in chronic intoxication.
Chytridiomycosis is affecting amphibians worldwide, causing the decline and extinction of several amphibian populations. The disease is caused by the fungus
Batrachochytrium dendrobatidis
(
Bd
), a ...multihost pathogen living in freshwater habitats. While several environmental factors have been associated with the prevalence of
Bd
and its virulence, the effects of water quality on the pathogen are not clear yet. Some evidence suggests that water pollution may reduce amphibians’ immune response and increase prevalence of
Bd
. To explore this hypothesis, we analyzed the relationship between water quality and the presence of
Bd
by using spatial data mining of 150 geolocations of
Bd
in amphibians from 9 families where
Bd
positive specimens have been previously reported, and water quality in 4,202 lentic and lotic water bodies in Mexico from 2010 to 2021. Our model showed that in the 3 main families where
Bd
was recorded, its presence is high in locations with low water quality, i.e., water polluted likely contaminated with urban and industrial waste. Using this model, we inferred areas suitable for
Bd
in Mexico; mainly in poorly studied areas along the gulf and on the pacific slope. We further argue that actions to reduce water pollution should become an integral part of public policies to prevent the spread of
Bd
and protect amphibians from this deadly pathogen.
Introduction. The present study evaluated the quality of medical care for patients diagnosed with diabetes mellitus (DM), hypertension (HBP), and both pathologies (DM+HBP) within a public health ...system in Mexico. Methods. 45,498 patients were included from 2012 to 2015. All information was taken from the electronic medical record database. Each patient record was compared against the standard to test the quality of medical care. Results. Glycemia with hypertension goals reached 29.6% in DM+HBP, 48.6% in DM, and 53.2% in HBP. The goals of serum lipids were reached by 3% in DM+HBP, 5% in DM, and 0.2% in HBP. Glycemia, hypertension, and LDL cholesterol reached 0.04%. 15% of patients had an undiagnosed disease. Clinical follow-up examinations reached 20% for foot examination and clinical eye examination. Specialty referrals reached 1% in angiology or cardiology. Conclusion. Goals for glycemic and hypertension reached 50% in the overall population, while serum lipids, clinical follow-up examinations, and referral to a specialist were deficient. Patients who had both diseases had more consultations, better control for hypertension and lipids, but inferior glycemic control. Overall, quality care for DM and/or HBP has not been met according to the standards.
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