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Cadmium (Cd) is a metal used in various industrial applications, thereby causing exposure to Cd-containing fumes. The submicron-sized particles in the fumes represent an extra risk due to their high mobility within the organism and high surface area. Toxicity of Cd on the liver, kidney and bones is well known, but there are less data on its neurotoxicity. Here, male Wistar rats were treated for 3 and 6 weeks by intratracheal instillation of cadmium oxide nanosuspension. The body weight gain in treated rats was significantly decreased, and in the rats treated with high dose (0.4 mg/kg Cd daily), there was a significant increase in the weight of lungs and thymus. In this group, the spectrum of spontaneous cortical electrical activity was shifted to higher frequencies, the latency of sensory-evoked potentials was lengthened, and the frequency following ability of the somatosensory evoked potential was impaired--even without detectable Cd deposition in the brain. The data support the role of the nano-sized Cd in the causation of nervous system damage and show the possibility of modeling human neurotoxic damage in rats.

Cadmium, a toxic heavy metal with various applications in technology, can affect people both by environmental (foodborne) and occupational (inhalation) exposure and can cause nervous system damage. To model this, rats were subacutely treated either with CdCl(2) solution per os (3.0 mg kg(-1) b.w.) or nanoparticulate CdO(2) (particle size ca 65 nm) by intratracheal instillation (0.04 mg kg(-1) b.w.) alone or in sequential combination. Nervous system effects were observed at different levels of function (open field behavior, cortical electrical activity, nerve action potential) and some general toxicological indicators were also measured. Three weeks of oral plus one week of intratracheal exposure caused significant reduction of body weight gain and open field motility. Lengthening of latency of sensory evoked potentials, observed in all treated rats, was also the most significant in the group receiving oral plus intratracheal treatment. Conduction velocity of the tail nerve was likewise decreased in all treated groups. Several of the effects pointed to a potentiating interaction between the two forms of Cd. Modeling environmental and occupational Cd exposure by oral and intratracheal application in rats was feasible, with results suggesting serious negative health effects in humans suffering such a combined exposure., (Copyright © 2011 John Wiley & Sons, Ltd.)

We report the synthesis of N-doped TiO(2) nanofibers and high photocatalytic efficiency in generating hydrogen from ethanol-water mixtures under UV-A and UV-B irradiation. Titanate nanofibers synthesized by hydrothermal method are annealed in air and/or ammonia to achieve N-doped anatase fibers. Depending on the synthesis route, either interstitial N atoms or new N-Ti bonds appear in the lattice, resulting in slight lattice expansion as shown by XPS and HR-TEM analysis, respectively. These nanofibers were then used as support for Pd and Pt nanoparticles deposited with wet impregnation followed by calcination and reduction. In the hydrogen generation tests, the N-doped samples were clearly outperforming their undoped counterparts, showing remarkable efficiency not only under UV-B but also with UV-A illumination. When 100 mg of catalyst (N-doped TiO(2) nanofiber decorated with Pt nanoparticles) was applied to 1 L of water-ethanol mixture, the H(2) evolution rates were as high as 700 μmol/h (UV-A) and 2250 μmol/h (UV-B) corresponding to photo energy conversion percentages of ∼3.6 and ∼12.3%, respectively.

Context and Objective: Lead (Pb) is a heavy metal harmful for human health and environment. From leaded gasoline (still used in certain countries), and in Pb processing and reprocessing industries, airborne particles are emitted which can be inhaled. In such exposure, the size of particles entering the airways is crucial. The nervous system is a primary target for Pb, and consequences like occupational neuropathy and delayed mental development of children are well-known. The aim of this work was to investigate the neurotoxicity of Pb nanoparticles (NPs) applied into the airways of rats., Methods: Nano-sized lead oxide particles (mean diameter ca. 20 nm) were suspended in distilled water and instilled into the trachea of adult male Wistar rats (in doses equivalent to 2 and 4 mg/kg Pb), 5 times a week for 3 and 6 weeks. At the end, open field motility was tested, then central and peripheral nervous activity was recorded in urethane anesthesia., Results and Conclusion: The treated rats' body weight gain was significantly lower than that of the controls from the 3rd week onwards, and the weight of their lungs was significantly increased. Horizontal motility increased while vertical motility decreased. Spontaneous cortical activity was shifted to higher frequencies. The somatosensory cortical evoked potential showed increased latency and decreased frequency-following ability, and similar alterations were seen in the tail nerve. Significant Pb deposition was measured in blood, brain, lung and liver samples of the treated rats. The experiments performed seem to constitute an adequate model of the human effects of inhaled Pb NPs.

Heterogeneous catalysis is a chemical process achieved at solid–gas or solid–liquid interfaces. Many factors including the particle size, shape and metal-support interfaces can have significant influences on the catalytic properties of metal catalysts. The recent progress in the synthesis techniques and advanced characterization tools allow to understand the catalytic mechanisms at molecular level. In this Review, the size and shape dependent catalytic chemistry of metal nanoparticles and their electronic properties will be discussed. Then the unique catalytic chemistry at the metal-support interfaces will be discussed in details. Furthermore, the challenges of bimetallic nanoparticle catalytic chemistry will be discussed. [ABSTRACT FROM AUTHOR]

The activation and conversion of CO 2 can be achieved on multifunctional catalytic sites at the metal/oxide interface by taking advantage of the synergy between noble metal nanoparticles and supports. Herein, sequential deposition of noble metals (Ru, Rh, and Pt) and nanodiamonds (NDs) was carried out on the surface of strontium titanates (STO). The noble metals and NDs were deposited in either 1 wt% or 10 wt%. The samples were characterized with in-situ as well as ex-situ spectroscopic and microscopic techniques and tested towards photocatalytic CO 2 hydrogenation. The sequential deposition of the noble metals and NDs enhanced light absorption properties, which also led to higher photocatalytic activity. The STO-ND-Ru sample had the highest photocatalytic CO 2 hydrogenation efficiency (47.5%) and showed improved selectivity for CH 4 (14.5%). Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) studies showed that the hydrogenation of CO 2 to CO and CH 4 followed different mechanisms for pristine STO and STO-ND-Ru. [Display omitted] • Strontium titanates (STO) were modified with nanodiamonds (ND) and noble metals. • Modification with NDs and ruthenium enhanced photocatalytic CO 2 reduction the most. • Higher light absorption resulted in higher yield of CO and CH 4. • Formate is the key photoactive intermediate in the photoreduction of CO 2. • A charge transfer mechanism and reaction scheme are proposed. [ABSTRACT FROM AUTHOR]

Fossil fuel depletion, global warming, climate change, and steep hikes in the price of fuel are driving scientists to investigate commercial and environmentally friendly energy carriers like hydrogen. Steam methane reforming (SMR), a current commercial route for H 2 production, has been considered the best remedy to fulfill the requirements. Despite the remarkable quantity of H 2 produced by the SMR, this technology still faces major challenges such as catalyst deactivation due to the sintering of metal nanoparticles, coking, and generation of a large quantity of CO 2. Firstly, the effects of catalyst types, kinetic models, and operating conditions on high-yield H 2 production, the evolution path from gray to blue, via the conventional SMR are comprehensively reviewed. Secondly, exploiting intensified techniques such as membrane technology, sorption, fluidization, and chemical looping for SMR to blue H 2 are discussed in detail. Further, a novel and sustainable path for the SMR process, hybridizing the use of novel materials and emerging technologies to produce turquoise H 2 , is proposed. Finally, the critical points for steam reforming process technology that can help leverage environmental, social, and governance (ESG) profiling have been discussed. [Display omitted] • Evolution path from gray to turquoise H 2 via catalytic SMR is discussed. • Recent advances in catalysis, kinetic models, and operating conditions are reviewed. • The importance of SMR process intensification for blue H 2 production is highlighted. • A novel and sustainable path for the SMR process to efficiently produce turquoise H 2 is proposed. • Key points for SMR technology that can help leverage ESG profiling are listed. [ABSTRACT FROM AUTHOR]

In this study, a set of nitrogen-doped TiO-based nanomaterials demonstrating photocatalytic activity was developed by combining the efforts of lattice doping and metal nanoparticle decoration and tested for photo-degradation of methylene blue dye by applying solar simulator irradiation. The surface potential shifts of these TiO-based photocatalytic nanomaterials measured by Kelvin probe force microscope have been used to study the degree of electron generation of the photocatalysts after irradiation and were well correlated with the photocatalytic activity. The nitrogen-doped TiO nanowires decorated with Pt nanoparticles can induce obvious electron accumulation and result in a large shift of surface potential. The analysis shows a clear correlation between the surface potential shift and the photodegradation activity. Furthermore, a thorough comparative photocatalytic activity study combined with X-ray photoelectron spectroscopy analysis of the materials-doped with nitrogen under various conditions-reveals that the photocatalytic efficiency of the catalysts is maintained even if the lattice doping is leached e.g., by thermal treatments after doping. Graphical Abstract: By monitoring the surface potential shifts of various TiO-based photocatalysts by photo-assisted Kelvin probe force microscopy, we obtain a useful tool for developing novel materials with high photocatalytic activity.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]