Chances and risks of nanomaterials for health and environment

Nanomaterials have properties that are often very different from normal materials made of the same substance, which can be used to create novel products with exciting properties. However, the health and environmental impact of these nanomaterials is also changed and their potential risk needs to be studied. There is evidence that some nanomaterials can pass through tissue barriers (including the blood-brain barrier) and cell membranes. This is interesting for medical applications, but it raises concerns about the impact of non-medical nanomaterials. Current research aims at better coordinating research efforts and at better communication between researchers and involved stakeholders. Many research labs and production sites currently follow strategies that were established for dealing with very toxic chemicals and powders, until future research in this field helps identify the appropriate level of protection. All these efforts will ultimately ensure a safe, healthy and environmental friendly production, use and disposal of nanomaterials.

Role of Sam68 in post-transcriptional gene regulation.

The STAR family of proteins links signaling pathways to various aspects of post-transcriptional regulation and processing of RNAs. Sam68 belongs to this class of heteronuclear ribonucleoprotein particle K (hnRNP K) homology (KH) single domain-containing family of RNA-binding proteins that also contains some domains predicted to bind critical components in signal transduction pathways. In response to phosphorylation and other post-transcriptional modifications, Sam68 has been shown to have the ability to link signal transduction pathways to downstream effects regulating RNA metabolism, including transcription, alternative splicing or RNA transport. In addition to its function as a docking protein in some signaling pathways, this prototypic STAR protein has been identified to have a nuclear localization and to take part in the formation of both nuclear and cytosolic multi-molecular complexes such as Sam68 nuclear bodies and stress granules. Coupling with other proteins and RNA targets, Sam68 may play a role in the regulation of differential expression and mRNA processing and translation according to internal and external signals, thus mediating important physiological functions, such as cell death, proliferation or cell differentiation.

Harmonic Nanocrystals for Biolabeling: A Survey of Optical Properties and Biocompatibility.

Nonlinear optical nanocrystals have been recently introduced as a promising alternative to fluorescent probes for multiphoton microscopy. We present for the first time a complete survey of the properties of five nanomaterials (KNbO(3), LiNbO(3), BaTiO(3), KTP, and ZnO), describing their preparation and stabilization and providing quantitative estimations of their nonlinear optical response. In the light of their prospective use as biological and clinical markers, we assess their biocompatibility on human healthy and cancerous cell lines. Finally, we demonstrate the great potential for cell imaging of these inherently nonlinear probes in terms of optical contrast, wavelength flexibility, and signal photostability.

A convex optimization framework for global tractography

In this article we present a novel approach for diffusion MRI global tractography. Our formulation models the signal in each voxel as a linear combination of fiber-tract basis func- tions, which consist of a comprehensive set of plausible fiber tracts that are locally compatible with the measured MR signal. This large dictionary of candidate fibers is directly estimated from the data and, subsequently, efficient convex optimization techniques are used for recovering the smallest subset globally best fitting the measured signal. Experimen- tal results conducted on a realistic phantom demonstrate that our approach significantly reduces the computational cost of global tractography while still attaining a reconstruction quality at least as good as the state-of-the-art global methods.

Sodium sensing in neurons with a dendrimer-based nanoprobe.

Ion imaging is a powerful methodology to assess fundamental biological processes in live cells. The limited efficiency of some ion-sensing probes and their fast leakage from cells are important restrictions to this approach. In this study, we present a novel strategy based on the use of dendrimer nanoparticles to obtain better intracellular retention of fluorescent probes and perform prolonged fluorescence imaging of intracellular ion dynamics. A new sodium-sensitive nanoprobe was generated by encapsulating a sodium dye in a PAMAM dendrimer nanocontainer. This nanoprobe is very stable and has high sodium sensitivity and selectivity. When loaded in neurons in live brain tissue, it homogenously fills the entire cell volume, including small processes, and stays for long durations, with no detectable alterations of cell functional properties. We demonstrate the suitability of this new sodium nanosensor for monitoring physiological sodium responses such as those occurring during neuronal activity.

Valoración de la calidad de vida tras implante de cabestrillo ajustable tipo remeex en incontinencia de orina femenina recidivada o insuficiencia esfinteriana intrínseca

Se evalúa la calidad de vida (CdV) tras implante de cabestrillo suburetral ajustable (Remeex). Se analizan 54 mujeres, clasificadas mediante Prueba de la tos, Qtip, y Urodinamia en: incontinencia de orina recidivada (IOEr: 25 casos) e incontinencia esfinteriana intrínseca (IEI:29 casos). La CdV se evalúa mediante el cuestionario específico Kings Health (KH). Tras un seguimiento medio de 49 meses, 46 pacientes (85%) estaban curadas de IOE. Las puntuaciones en CdV muestran una mejoría estadísticamente significativa en 8/9 dominios del KH. Podemos concluir que la cirugía de Remeex condiciona una mejoría estadísticamente significativa en la CdV percibida por las pacientes.

[Archives de la Parole]. , [The story of the herdsman] : shindi [i.e. sindhi], Indo-aryen, groupe occidental / [Sir George Grierson], éd. ; Linguistic survey of India ; [V.T. Shimpi], voix

[Traditions. Asie. Inde. Province de Bombay. État du Maharashtra. Dhule]

Time-Lapse AFM Imaging of DNA Conformational Changes Induced by Daunorubicin.

Cancer is a major health issue that absorbs the attention of a large part of the biomedical research. Intercalating agents bind to DNA molecules and can inhibit their synthesis and transcription; thus, they are increasingly used as drugs to fight cancer. In this work, we show how atomic force microscopy in liquid can characterize, through time-lapse imaging, the dynamical influence of intercalating agents on the supercoiling of DNA, improving our understanding of the drug's effect.

[Archives de la Parole]. , Parabole de l'enfant prodigue : en shindi - groupe occidental, Indo-aryen / [Sir George Grierson], éd. ; Linguistic survey of India ; [V.T. Shimpi], voix

[Traditions. Asie. Inde. État du Maharashtra. Dhule]

Nanopore detection of single molecule RNAP-DNA transcription complex.

In the past decade, a number of single-molecule methods have been developed with the aim of investigating single protein and nucleic acid interactions. For the first time we use solid-state nanopore sensing to detect a single E. coli RNAP-DNA transcription complex and single E. coli RNAP enzyme. On the basis of their specific conductance translocation signature, we can discriminate and identify between those two types of molecular translocations and translocations of bare DNA. This opens up a new perspectives for investigating transcription processes at the single-molecule level.

An Efficient Segmentation Method for Ultrasound Images based on a Semi-supervised Approach and Patch-based Features

Segmenting ultrasound images is a challenging problemwhere standard unsupervised segmentation methods such asthe well-known Chan-Vese method fail. We propose in thispaper an efficient segmentation method for this class ofimages. Our proposed algorithm is based on asemi-supervised approach (user labels) and the use ofimage patches as data features. We also consider thePearson distance between patches, which has been shown tobe robust w.r.t speckle noise present in ultrasoundimages. Our results on phantom and clinical data show avery high similarity agreement with the ground truthprovided by a medical expert.