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1.
Nanoscale Adv ; 5(3): 701-710, 2023 Jan 31.
Article in English | MEDLINE | ID: mdl-36756503

ABSTRACT

We synthesized nickel (Ni) nanoparticles (NPs) in a high specific surface area (SSA) p-block element-containing inorganic compound prepared via the polymer-derived ceramics (PDC) route to dispatch the obtained nanocomposite towards oxygen evolution reaction (OER). The in situ formation of Ni NPs in an amorphous silicon carboxynitride (Si-C-O-N(H)) matrix is allowed by the reactive blending of a polysilazane, NiCl2 and DMF followed by the subsequent thermolysis of the Ni : organosilicon polymer coordination complex at a temperature as low as 500 °C in flowing argon. The final nanocomposite displays a BET SSA as high as 311 m2 g-1 while the structure of the NPs corresponds to face-centred cubic (fcc) Ni along with interstitial-atom free (IAF) hexagonal close-packed (hcp) Ni as revealed by XRD. A closer look into the compound through FEG-SEM microscopy confirms the formation of pure metallic Ni, while HR-TEM imaging reveals the occurrence of Ni particles featuring a fcc phase and surrounded by carbon layers; thus, forming core-shell structures, along with Ni NPs in an IAF hcp phase. By considering that this newly synthesized material contains only Ni without doping (e.g., Fe) with a low mass loading (0.15 mg cm-2), it shows promising OER performances with an overpotential as low as 360 mV at 10 mA cm-2 according to the high SSA matrix, the presence of the IAF hcp Ni NPs and the development of core-shell structures. Given the simplicity, the flexibility, and the low cost of the proposed synthesis approach, this work opens the doors towards a new family of very active and stable high SSA nanocomposites made by the PDC route containing well dispersed and accessible non-noble transition metals for electrocatalysis applications.

2.
Trop Anim Health Prod ; 54(4): 237, 2022 Jul 22.
Article in English | MEDLINE | ID: mdl-35864408

ABSTRACT

Crimean-Congo hemorrhagic fever virus (CCHFV) is a widespread zoonotic pathogen that can cause mild to severe hemorrhagic disease in humans. CCHFV may be transmitted through direct contact with tissue or blood of viremic animals; however, the primary transmission route is through infected tick bites. CCHFV RNA has been detected in ticks feeding on domestic and wild animals in western Spain, suggesting an established circulation of CCHFV in Western Europe. Ruminants have been recognized as important CCHFV reservoirs and have been linked to human cases in endemic regions. Given the emergence of CCHF in neighboring Spain, and a report of two CCHFV seropositive humans in southern Portugal in 1985, we investigated the potential circulation of this virus in the country by performing a nationwide anti-CCHFV IgG serosurvey in sentinel sheep of Portugal. Sera (n = 459) randomly selected from widely distributed farms (n = 20) of Portugal were tested using a commercial double-antigen enzyme-linked immunosorbent assay, yielding an overall seroprevalence of 0.4% (95% confidence interval [CI] 0.04-1.56%). Positive sheep were from the southern region of Portugal (Alentejo region), which raise the seroprevalence of this region to 0.74% (95% CI 0.09-2.66%). This is the first study reporting the presence of CCHFV antibodies in sheep of Portugal, thus suggesting a geographical expansion of CCHFV to this country. It seems likely that CCHFV may exist focally in southern Portugal.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Sheep Diseases , Ticks , Animals , Antibodies, Viral , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/veterinary , Humans , Portugal/epidemiology , Seroepidemiologic Studies , Sheep , Sheep Diseases/epidemiology
3.
Emerg Infect Dis ; 26(5): 1041-1044, 2020 05.
Article in English | MEDLINE | ID: mdl-32310061

ABSTRACT

We conducted a serologic survey for Crimean-Congo hemorrhagic fever virus antibodies in livestock (cattle, sheep, and goats; N = 3,890) on Corsica (island of France) during 2014-2016. Overall, 9.1% of animals were seropositive, suggesting this virus circulates on Corsica. However, virus identification is needed to confirm these results.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Animals , Antibodies, Viral , Cattle , France/epidemiology , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/veterinary , Livestock , Sheep
4.
Bioelectromagnetics ; 35(6): 444-51, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25099539

ABSTRACT

Emerging high data rate wireless communication systems, currently under development, will operate at millimeter waves (MMW) and specifically in the 60 GHz band for broadband short-range communications. The aim of this study was to investigate potential effects of MMW radiation on the cellular endoplasmic reticulum (ER) stress. Human skin cell lines were exposed at 60.4 GHz, with incident power densities (IPD) ranging between 1 and 20 mW/cm(2) . The upper IPD limits correspond to the ICNIRP local exposure limit for the general public. The expression of ER-stress sensors, namely BIP and ORP150, was then examined by real-time RT-PCR. Our experimental data demonstrated that MMW radiations do not change BIP or ORP150 mRNA basal levels, whatever the cell line, the exposure duration or the IPD level. Co-exposure to the well-known ER-stress inducer thapsigargin (TG) and MMW were then assessed. Our results show that MMW exposure at 20 mW/cm(2) inhibits TG-induced BIP and ORP150 over expression. Experimental controls showed that this inhibition is linked to the thermal effect resulting from the MMW exposure.


Subject(s)
Electromagnetic Radiation , Endoplasmic Reticulum Stress/genetics , Endoplasmic Reticulum Stress/radiation effects , Hot Temperature , Cell Line , Endoplasmic Reticulum Stress/drug effects , Endoplasmic Reticulum Stress/physiology , Enzyme Inhibitors/pharmacology , Gene Expression/drug effects , Gene Expression/physiology , Gene Expression/radiation effects , HSP70 Heat-Shock Proteins/metabolism , Humans , RNA, Messenger/metabolism , Real-Time Polymerase Chain Reaction , Skin/drug effects , Skin/radiation effects , Skin Physiological Phenomena/drug effects , Skin Physiological Phenomena/genetics , Skin Physiological Phenomena/radiation effects , Thapsigargin/pharmacology , Time Factors , Wireless Technology
5.
Virus Res ; 179: 187-203, 2014 Jan 22.
Article in English | MEDLINE | ID: mdl-24184319

ABSTRACT

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus responsible for hemorrhagic manifestations and multiple organ failure, with a high mortality rate. In infected humans, damage to endothelial cells and vascular leakage may be a direct result of virus infection or an immune response-mediated indirect effect. The main target cells are mononuclear phagocytes, endothelial cells and hepatocytes; the liver being a key target for the virus, which was described as susceptible to interferon host response and to induce apoptosis. To better understand the early liver cell alterations due to virus infection, the protein profile of in vitro CCHFV-infected HepG2 cells was analyzed using two quantitative proteomic approaches, 2D-DIGE and iTRAQ. A set of 243 differentially expressed proteins was identified. Bioinformatics analysis (Ingenuity Pathways Analysis) revealed multiple host cell pathways and functions altered after CCHFV infection, with notably 106 proteins related to cell death, including 79 associated with apoptosis. Different protein networks emerged with associated pathways involved in inflammation, oxidative stress and apoptosis, ubiquitination/sumoylation, regulation of the nucleo-cytoplasmic transport, and virus entry. Collectively, this study revealed host liver protein abundances that were modified at the early stages of CCHFV infection, offering an unparalleled opportunity of the description of the potential pathogenesis processes and of possible targets for antiviral research.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo/physiology , Hemorrhagic Fever, Crimean/metabolism , Hemorrhagic Fever, Crimean/virology , Hepatocytes/virology , Animals , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/genetics , Hepatocytes/chemistry , Hepatocytes/metabolism , Humans , Molecular Sequence Data , Proteins/chemistry , Proteins/genetics , Proteins/metabolism , Proteomics
6.
Bioelectromagnetics ; 30(5): 365-73, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19274636

ABSTRACT

The main purpose of this article is to study potential biological effects of low-power millimeter waves (MMWs) on endoplasmic reticulum (ER), an organelle sensitive to a wide variety of environmental insults and involved in a number of pathologies. We considered exposure frequencies around 60 GHz in the context of their near-future applications in wireless communication systems. Radiations within this frequency range are strongly absorbed by oxygen molecules, and biological species have never been exposed to such radiations in natural environmental conditions. A set of five discrete frequencies has been selected; three of them coincide with oxygen spectral lines (59.16, 60.43, and 61.15 GHz) and two frequencies correspond to the spectral line overlap regions (59.87 and 60.83 GHz). Moreover, we used a microwave spectroscopy approach to select eight frequencies corresponding to the spectral lines of various molecular groups within 59-61 GHz frequency range. The human glial cell line, U-251 MG, was exposed or sham-exposed for 24 h with a peak incident power density of 0.14 mW/cm(2). The average specific absorption rate (SAR) within the cell monolayer ranges from 2.64 +/- 0.08 to 3.3 +/- 0.1 W/kg depending on the location of the exposed well. We analyzed by quantitative reverse transcription-polymerase chain reaction (RT-PCR) the level of expression of two endogenous ER-stress biomarkers, namely, the chaperones BiP/GRP78 and ORP150/GRP170. It was found that exposure to low-power MMW does not significantly modify the mRNA levels of these stress-sensitive genes suggesting that ER homeostasis is not altered by low-power MMW at the considered frequencies.


Subject(s)
Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/radiation effects , Radio Waves/adverse effects , Stress, Physiological/genetics , Animals , Cell Line, Tumor , Endoplasmic Reticulum Chaperone BiP , Environmental Exposure , Heat-Shock Proteins/genetics , Humans , RNA, Messenger/genetics , RNA, Messenger/metabolism , Stress, Physiological/radiation effects , Telecommunications , Transcriptional Activation/radiation effects
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