Evaluation of a TEM based Approach for Size Measurement of Particulate (Nano)materials.

An approach for the size measurement of particulate (nano)materials by transmission electron microscopy was evaluated. The approach combines standard operating procedures for specimen preparation, imaging, and image analysis, and it was evaluated on a series of certified reference materials and representative test materials with varying physical properties, including particle size, shape, and agglomeration state. The measurement of the median value of the minimal external particle diameter distribution was intra-laboratory validated.

Validation of a particle tracking analysis method for the size determination of nano- and microparticles.

Particle tracking analysis (PTA) is an emerging technique suitable for size analysis of particles with external dimensions in the nano- and sub-micrometre scale range. Only limited attempts have so far been made to investigate and quantify the performance of the PTA method for particle size analysis. This article presents the results of a validation study during which selected colloidal silica and polystyrene latex reference materials with particle sizes in the range of 20 nm to 200 nm were analysed with NS500 and LM10-HSBF NanoSight instruments and video analysis software NTA 2.

Improved Metrological Traceability of Particle Size Values Measured with Line-Start Incremental Centrifugal Liquid Sedimentation.

Line-start incremental centrifugal liquid sedimentation (disc-CLS) is a powerful method to determine particle size based on the principles of Stokes' law. Because several of the input quantities of the Stokes equation cannot be easily determined for this case of a rotating disc, the disc-CLS approach relies on calibrating the sedimentation time scale with reference particles. To use these calibrant particles for establishing metrological traceability, they must fulfill the same requirements as those imposed on a certified reference material, i.

Challenges in the size analysis of a silica nanoparticle mixture as candidate certified reference material.

A new certified reference material for quality control of nanoparticle size analysis methods has been developed and produced by the Institute for Reference Materials and Measurements of the European Commission's Joint Research Centre. The material, ERM-FD102, consists of an aqueous suspension of a mixture of silica nanoparticle populations of distinct particle size and origin. The characterisation relied on an interlaboratory comparison study in which 30 laboratories of demonstrated competence participated with a variety of techniques for particle size analysis.

Dietary silver nanoparticles can disturb the gut microbiota in mice.

Background: Humans are increasingly exposed via the diet to Ag nanoparticles (NP) used in the food industry. Because of their anti-bacterial activity, ingested Ag NP might disturb the gut microbiota that is essential for local and systemic homeostasis. We explored here the possible impact of dietary Ag NP on the gut microbiota in mice at doses relevant for currently estimated human intake.

Engineering a nanopore with co-chaperonin function.

The emergence of an enzymatic function can reveal functional insights and allows the engineering of biological systems with enhanced properties. We engineered an alpha hemolysin nanopore to function as GroES, a protein that, in complex with GroEL, forms a two-stroke protein-folding nanomachine. The transmembrane co-chaperonin was prepared by recombination of GroES functional elements with the nanopore, suggesting that emergent functions in molecular machines can be added bottom-up by incorporating modular elements into preexisting protein scaffolds.

TEM and SP-ICP-MS analysis of the release of silver nanoparticles from decoration of pastry.

Metallic silver is an EU approved food additive referred to as E174. It is generally assumed that silver is only present in bulk form in the food chain. This work demonstrates that a simple treatment with water of "silver pearls", meant for decoration of pastry, results in the release of a subfraction of silver nanoparticles.

Genotoxicity evaluation of nanosized titanium dioxide, synthetic amorphous silica and multi-walled carbon nanotubes in human lymphocytes.

Toxicological characterization of manufactured nanomaterials (NMs) is essential for safety assessment, while keeping pace with innovation from their development and application in consumer products. The specific physicochemical properties of NMs, including size and morphology, might influence their toxicity and have impact on human health. The present work aimed to evaluate the genotoxicity of nanosized titanium dioxide (TiO2), synthetic amorphous silica (SAS) and multiwalled carbon nanotubes (MWCNTs), in human lymphocytes.

Effects of lung exposure to carbon nanotubes on female fertility and pregnancy. A study in mice.

We studied the effects of preconceptional exposure to multiwalled carbon nanotubes (MWCNTs): mature, female C57BL/6J mice were intratracheally instilled with 67μg NM-400 MWCNT, and the following day co-housed with mature males, in breeding pairs. Time to delivery of the first litter, litter parameters, maternal inflammation and histopathology of lung and liver were recorded. In male offspring, locomotor activity, startle response, and daily sperm production (DSP) were assessed.

Street characteristics and traffic factors determining road users' exposure to black carbon.

Many studies nowadays make the effort of determining personal exposure rather than estimating exposure at the residential address only. While intra-urban air pollution can be modeled quite easily using interpolation methods, estimating exposure in transport is more challenging. The aim of this study is to investigate which factors determine black carbon (BC) concentrations in transport microenvironments.

Combined endovascular treatment of aorto-oesophageal fistula with mediastinitis.

False aortic aneurysm is an uncommon complication after oesophageal perforation and results in a high rate of mortality. A 63-year-old patient presented with acute chest pain. Biochemical tests (cardiac enzymes) and electrocardiogram were normal.

Quantitative characterization of agglomerates and aggregates of pyrogenic and precipitated amorphous silica nanomaterials by transmission electron microscopy.

Background: The interaction of a nanomaterial (NM) with a biological system depends not only on the size of its primary particles but also on the size, shape and surface topology of its aggregates and agglomerates. A method based on transmission electron microscopy (TEM), to visualize the NM and on image analysis, to measure detected features quantitatively, was assessed for its capacity to characterize the aggregates and agglomerates of precipitated and pyrogenic synthetic amorphous silicon dioxide (SAS), or silica, NM.

Results: Bright field (BF) TEM combined with systematic random imaging and semi-automatic image analysis allows measuring the properties of SAS NM quantitatively.

Determination of the volume-specific surface area by using transmission electron tomography for characterization and definition of nanomaterials.

Background: Transmission electron microscopy (TEM) remains an important technique to investigate the size, shape and surface characteristics of particles at the nanometer scale. Resulting micrographs are two dimensional projections of objects and their interpretation can be difficult. Recently, electron tomography (ET) is increasingly used to reveal the morphology of nanomaterials (NM) in 3D.

[Peutz-Jeghers syndrome. Description of a case and literature review].

The authors describe the case of a 7 year old boy who presented an intestinal intussusception due to a large jejunal hamartomatous jejunal polyp. The preoperative diagnosis of Peutz-Jeghers syndrome was based on typical mucocutaneous pigmentation and confirmed by radiological examination including computerized tomography of the abdomen. Following recent data from the literature, a long-term surveillance is justified after diagnosis of this syndrome, since malignant degeneration may occur within the intestinal polyps as well as in other organs.

[The child with defective hearing. Medical, educational, sociological and psychological aspects].

Hearing impairment in children is considered in its various aspects: medical, sociological, psychological, and educational. After a review of the aetiologies, the biological consequences of early auditory deprivation are underlined. The necessity of avoiding or reducing them justifies the efforts made to insure early diagnosis and adequate intervention.

Anesthetic protocol in human renal transplantation: twenty-two years of experience.

This paper reviews the experience of 22 years of transplantation. From June 1963 to December 1984, 1362 human renal grafts were performed in our center. Throughout this period, advances in surgical techniques, kidney preservation methods and immunosuppressive regimen have improved patient and graft survival.

[Integrated services in emergency medicine: the Regional Center for Emergency Medical Assistance].

According to the law of 8 July 1964, the Belgian State is responsible for the treatment of the emergencies in the public ways and places. Due to an important spontaneous private extension, among the 502.600 annual calls the 252.

Enflurane in renal transplantation: report of 375 cases.

Our experience to date covers 675 kidney grafts performed in the Transplantation Department of the University of Louvain. The evolution of our anaesthesia methods has led us since the end of 1973 to conduct 375 transplantations with enflurane. The patients, aged between 18 months and 50 years, receive a conventional premedication, do not receive corticoids preoperatively nor undergo dialysis immediately prior to operation, but systematically receive a 5-unit transfusion beforehand.

Clinical and bacteriological evaluation of amikacin in severe gram-negative infections.

Amikacin was administered to 51 patients with serious Gram-negative infections. A favorable clinical outcome was observed in 32 patients (62 per cent). No major untoward effects were noted.