Travelers lowering their guard: a bacterial, viral and protozoan co-infection after a five-day journey in India

We present a case of concurrent infections by Campylobacter jejuni, Giardia intestinalis and Hepatitis E virus acquired during a 5-days travel to India by an Italian traveller : Professionals responsible for pre- and post-travel care should underline food and water precautions and prescribe an adequate diagnostic work-up in symptomatic patients.

Facile and quick preparation of carbon nanohorn-based counter electrodes for efficient dye-sensitized solar cells

For the first time, Pt-free counter electrodes based on carbon nanohorns for highly efficient dye-sensitized solar cells were assembled by a facile and fast drop cast technique. These novel electrodes feature an effective catalytic behavior towards the reduction of I3(-) and, as such, afford even higher short-circuit current densities compared to Pt-based references. In a final device, solar cells with 7.7% efficiency were achieved.

[60]Fullerene–porphyrin [n]pseudorotaxanes: self-assembly, photophysics and third-order NLO response

Herein we report a series of porphyrin and methano[60]fullerene that undergo self-assembly.

Highly efficient hydrogen production through ethanol photoreforming by a carbon nanocone/Pd@TiO2 hybrid catalyst

Production of molecular hydrogen (H₂) is becoming an increasingly prominent process, due to the high expectations as a new green energy carrier and key reagent for many industrial processes.

Under the lens: carbon nanotube and protein interaction at the nanoscale

The combination of the very different chemical natures of carbon nanotubes (CNTs) and proteins gives rise to systems with unprecedented performance, thanks to a rich pool of very diverse chemical, electronic, catalytic and biological properties. Here we review recent advances in the field, including innovative and imaginative aspects from a nanoscale point of view. The tubular nature of CNTs allows for internal protein encapsulation, and also for their external coating by protein cages, affording bottom-up ordering of molecules in hierarchical structures. To achieve such complex systems it is imperative to master the intermolecular forces between CNTs and proteins, including geometry effects (e.g. CNT diameter and curvature) and how they translate into changes in the local environment (e.g. water entropy). The type of interaction between proteins and CNTs has important consequences for the preservation of their structure and, in turn, function. This key aspect cannot be neglected during the design of their conjugation, be it covalent, non-covalent, or based on a combination of both methods. The review concludes with a brief discussion of the very many applications intended for CNT-protein systems that go across various fields of science, from industrial biocatalysis to nanomedicine, from innovative materials to biotechnological tools in molecular biology research.

In situ growth of capping-free magnetic iron oxide nanoparticles on liquid-phase exfoliated graphene

We report a facile approach for the in situ synthesis of very small iron oxide nanoparticles on the surface of high-quality graphene sheets. Our synthetic strategy involved the direct, liquid-phase exfoliation of highly crystalline graphite (avoiding any oxidation treatment) and the subsequent chemical functionalization of the graphene sheets via the well-established 1,3-dipolar cycloaddition reaction. The resulting graphene derivatives were employed for the immobilization of the nanoparticle precursor (Fe cations) at the introduced organic groups by a modified wet-impregnation method, followed by interaction with acetic acid vapours. The final graphene-iron oxide hybrid material was achieved by heating (calcination) in an inert atmosphere. Characterization by X-ray diffraction, transmission electron and atomic force microscopy, Raman and X-ray photoelectron spectroscopy gave evidence for the formation of rather small (<12 nm), spherical, magnetite-rich nanoparticles which were evenly distributed on the surface of few-layer (<1.2 nm thick) graphene. Due to the presence of the iron oxide nanoparticles, the hybrid material showed a superparamagnetic behaviour at room temperature.

Chemical modification of carbon nanomaterials (SWCNTs, DWCNTs, MWCNTs and SWCNHs) with diphenyl dichalcogenides

Control over chemical functionalization is a crucial point in the field of nanotechnology. Herein, we present the covalent functionalization of several carbon nanoforms (single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes and carbon nanohorns) by means of diphenyl dichalcogenides. These ones show different reactivity to the nanomaterials and are able to modify their electronic properties depending on the electronegativity of the functionalizing heteroatom. Theoretical calculations were also performed to support the experimental results. All the modified structured nanocarbons were thoroughly characterized by TGA Raman, XPS, UV/Vis/nIR, IR and TEM techniques. Our findings propose a simple approach to functionalize carbon nanomaterials and, in the meantime, to tune their electronic properties.

Carbon nanotubes and catalysis: the many facets of a successful marriage

Carbon nanotubes have emerged as unique carbon allotropes that bear very interesting prospects in catalysis.

Production of Sexuals and Mating Frequency in the Stingless Bee Tetragonisca angustula (Latreille) (Hymenoptera, Apidae)

Queen, worker, and male production was studied for 1 year in three queenright colonies of Tetragonisca angustula (Latreille). We sampled brood combs monthly and noticed that the number of brood cells and production of individuals were similar among colonies. Although the production of queens did not vary significantly, the frequencies of workers, males, and the number of cells among the combs varied over time. The production of males was highly seasonal, occurring mostly from February to April, coinciding with the period of intense brood cells production, when colonies produced more males and less workers, resulting in a negative correlation. Although the frequency of queens has not varied in time, the seasonal availability of males affected the mating frequency and the time spent since emergence until fertilization of queens. In the T. angustula colonies studied, the population dynamics was highly seasonal and the mating success depended of male production, according to the season.

Sandwich ELISA assay for the quantitation of palytoxin and its analogs in natural samples

Palytoxins are potent marine biotoxins that have recently become endemic to the Mediterranean Sea, and are becoming more frequently associated with seafood. Due to their high toxicity, suitable methods to quantify palytoxins are needed. Thus, we developed an indirect sandwich ELISA for palytoxin and 42-hydroxy-palytoxin. An intralaboratory study demonstrated sensitivity (limit of detection, LOD = 1.1 ng/mL; limit of quantitation, LOQ = 2.2 ng/mL), accuracy (bias of 2.1%), repeatability (RSDr = 6% and 9% for intra- and interassay variability, respectively) and specificity: other common marine toxins (okadaic acid, domoic acid, saxitoxin, brevetoxin-3, and yessotoxin) do not cross-react in this assay. It performed well in three different matrices: observed LOQs were 11.0, 9.6, and 2.4 ng/mL for mussel extracts, algal net samples and seawater, respectively, with good accuracy and precision. The LOQ in seafood is 11 μg palytoxin/kg mussel meat, lower than that of the most common detection technique, LC-MS/MS.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

A state observer for the Virgo inverted pendulum

We report an application of Kalman filtering to the inverted pendulum (IP) of the Virgo gravitational wave interferometer. Using subspace method system identification techniques, we calculated a linear mechanical model of Virgo IP from experimental transfer functions. We then developed a Kalman filter, based on the obtained state space representation, that estimates from open loop time domain data, the state variables of the system. This allows the observation (and eventually control) of every resonance mode of the IP mechanical structure independently.

Interaction of alkanethiols with nanoporous cluster-assembled Au films

This article presents a study of the interaction of octadecanethiol molecules (C(18)) with nanoporous cluster-assembled gold films under a liquid environment based on a combined spectroscopic ellipsometry and X-ray photoelectron spectroscopy investigation. By comparing the optical response, following the deposition of C(18), of cluster-assembled films with varying degrees of porosity with that of flat surfaces and by resolving the corresponding features of the molecule-Au bond, we have been able to define the conditions that either favor molecular in-depth diffusion into the pores or promote the formation of a molecular self-assembled monolayer (SAM) restricted to the film surface. In the presence of abundant open pores, C(18) molecules strongly diffuse within the film interior and bind to the pore walls, whereas in the presence of porous films with less abundant open pores we have observed that the molecules tend to remain confined to the surface region, adopting a SAM-like configuration.

A regularization algorithm for decoding perceptual temporal profiles from fMRI data

In several biomedical fields, researchers are faced with regression problems that can be stated as Statistical Learning problems. One example is given by decoding brain states from functional magnetic resonance imaging (fMRI) data. Recently, it has been shown that the general Statistical Learning problem can be restated as a linear inverse problem. Hence, new algorithms were proposed to solve this inverse problem in the context of Reproducing Kernel Hilbert Spaces. In this paper, we detail one iterative learning algorithm belonging to this class, called ν-method, and test its effectiveness in a between-subjects regression framework. Specifically, our goal was to predict the perceived pain intensity based on fMRI signals, during an experimental model of acute prolonged noxious stimulation. We found that, using a linear kernel, the psychophysical time profile was well reconstructed, while pain intensity was in some cases significantly over/underestimated. No substantial differences in terms of accuracy were found between the proposed approach and one of the state-of-the-art learning methods, the Support Vector Machines. Nonetheless, adopting the ν-method yielded a significant reduction in computational time, an advantage that became more evident when a relevant feature selection procedure was implemented. The ν-method can be easily extended and included in typical approaches for binary or multiple classification problems, and therefore it seems well-suited to build effective brain activity estimators.

In-vacuum Faraday isolation remote tuning

In-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment (Virgo), has a 20 mm clear aperture and is illuminated by an almost 20 W incoming beam, having a diameter of about 5 mm. When going in vacuum at 10(-6) mbar, a degradation of the isolation exceeding 10 dB was observed. A remotely controlled system using a motorized lambda=2 waveplate inserted between the first polarizer and the Faraday rotator has proven its capability to restore the optical isolation to a value close to the one set up in air.

Promises, facts and challenges for carbon nanotubes in imaging and therapeutics

The use of carbon nanotubes in medicine is now at the crossroads between a proof-of-principle concept and an established preclinical candidate for a variety of therapeutic and diagnostic applications. Progress towards clinical trials will depend on the outcomes of efficacy and toxicology studies, which will provide the necessary risk-to-benefit assessments for carbon-nanotube-based materials. Here we focus on carbon nanotubes that have been studied in preclinical animal models, and draw attention to the promises, facts and challenges of these materials as they transition from research to the clinical phase. We address common questions regarding the use of carbon nanotubes in disease imaging and therapy, and highlight the opportunities and challenges ahead.

Element-Specific Probe of the Magnetic and Electronic Properties of Dy incar-Fullerenes

The magnetic and electronic properties of a single atom and a pair of Dy atoms encapsulated inside fullerene carbon cages have been examined using X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) as well as resonant photoelectron spectroscopy (RESPES) across the Dy M(4,5)-edge. The comparison of the measured XAS spectra with multiplet calculations indicates that the encaged Dy has a 4f( 9) configuration. The presence of Dy 5d spectral weight in the valence band is not detected by RESPES, indicating that Dy is in a formally trivalent state. The evolution of the encaged Dy orbital and spin moments of the 4f orbitals as a function of the applied magnetic field and temperature has been obtained from XMCD measurements. At 6.9 T and 4 K, both the orbital and the spin magnetic moments of the encaged Dy 4f electrons are dramatically smaller than those expected for the free Dy(3+) at saturation.

Anti-inflammatory and anti-oxidant activity of a new class of phenyl-pyrazolone derivatives

The anti-inflammatory activity of a new class of phenyl-pyrazolone derivatives, structurally related to phenidone, has been evaluated using the Croton oil ear test in mice as model of acute inflammation. Derivative 5h reduces the percentage of oedema similarly to indomethacin and more efficiently than phenylbutazone. The anti-inflammatory activity of these two reference drugs depends on their COX inhibition, but for the synthesized derivatives it has not been demonstrated a significant COX or LOX inhibition, as previously reported. While the anti-inflammatory activity of phenidone is correlated to its anti-oxidant properties, the redox potential of these compounds appears not decisive in the inflammatory process inhibition. In order to investigate the mechanism of action for these compounds, we quantified their anti-oxidant activity and the lipophilicity, and a relationship between the calculated logP and the percentage of oedema reduction was found. We hypothesize that the anti-inflammatory activity, recorded in vivo, could be related to lipophilic parameter of these compounds.