High performance magnetorheological fluids: very high magnetization FeCo-Fe3O4 nanoclusters in a ferrofluid carrier.

High magnetization Fe3O4/OA-FeCo/Al2O3 nanocomposite magnetic clusters have been obtained using a modified oil-in-water miniemulsion method. These nanocomposite clusters dispersed in a ferrofluid carrier result in a magnetorheological fluid with improved characteristics. The magnetic clusters have a magnetic core consisting of a mixture of magnetite nanoparticles of about 6 nm average size, stabilized with oleic acid (Fe3O4/OA) and FeCo/Al2O3 particles of about 50 nm average size, compactly packed in the form of spherical clusters with a diameter distribution in the range 100-300 nm and a hydrophilic coating of sodium lauryl sulphate surfactant. The surface chemical composition of the Fe3O4/OA-FeCo/Al2O3 clusters investigated by XPS indicates the presence of the Co2+ and Co3+ oxidation states of cobalt and the components of Fe2+ and Fe3+ characteristic to both an enhanced oxidation state at the surface of the FeCo particles and to the presence of magnetic nanoparticles of spinel structure which are decorating the supporting FeCo. This specific decorating morphology is also indicated by TEM images. Advanced characterization of the Fe3O4/OA-FeCo/Al2O3 magnetic clusters has been performed using Mössbauer spectroscopy and magnetization measurements at various temperatures between 6 K and 200 K. The unexpected formation of Co ferrite decorating nanoparticles was supported by Mössbauer spectroscopy. The dispersion of magnetic clusters in the ferrofluid carrier highly influences the flow properties in the absence of the field (shear thinning for low and moderate shear rates) and especially in applied magnetic field, when significant magnetoviscous effect and shear thinning was observed for the whole range of shear rate values. Detailed analysis of the magnetorheological behavior of the nanocomposite magnetic clusters dispersed in a ferrofluid carrier evidence significantly higher normalized dynamic yield stress values in comparison with the magnetite nanocluster suspensions of the same mass concentration, a promising result for this new type of nanocomposite magnetorheological fluid.

Antiviral and lung protective activity of a novel respiratory syncytial virus fusion inhibitor in a mouse model.

Respiratory syncytial virus (RSV) causes bronchiolitis in young children and common colds in adults. There is no licensed vaccine, and prophylactic treatment with palivizumab is very expensive and limited to high-risk infants. Ribavirin is used as an antiviral treatment in infants and immunosuppressed patients, and its use is limited due to side-effects, toxicity to the recipient and staff, and evidence of marginal clinical efficacy. Therefore, we studied the in vivo kinetics, and the antiviral and protective properties of a novel candidate for RSV disease treatment. The drug is a small molecule (TMC353121) discovered by screening for fusion inhibitory properties against RSV in a cellular infection model. The pharmacokinetics of TMC353121 was studied in BALB/c mice and antiviral effects determined by testing viral loads in lung tissue by quantitative RT-PCR and plaque assay after intranasal RSV infection. At doses of 0.25-10 mg · kg(-1), TMC353121 significantly reduced viral load, bronchoalveolar lavage cell accumulation and the severity of lung histopathological change after infection. Treatment remained effective if started within 48 h of infection, but was ineffective thereafter. Therefore, TMC353121 is a novel potent antiviral drug, in vivo reducing RSV replication and inhibiting consequential lung inflammation, with a great potential for further clinical development.

[Lymphosarcoma of the lacrimal gland]. / Limfosarcom al glandei lacrimale.

The malignant lymphoreticular tumours of the lacrimal gland are quite rare. A female patient 65 years old presents a neoformation at the level of the lacrimal gland of the left eye, adhering to the profound planes. The extirpation of the lacrimal gland shows a diffuse infiltrate with atypical cells, shape, volume and tinctorial inequalities with frequent atypical mitosis, having an aspect of lymphosarcoma. The lymphoreticular infiltrate exceeds the own capsule of the gland, so the patient must follow a roentgen-therapeutical treatment.

[The staging of malignant uveal melanoma]. / Contributii la stadiul melanomului malign uveal.

There have been investigated 30 malignant uveal melanomas hospitalized in the Ophthalmologic Clinic of Craiova during the last 15 years. The disease has developed more frequently among the female sex in a 3/2 proportion, the maximum age ranging between, 40 and 70 years old. As to the localization, 2 were at the level of the iris, 7 at the level of ciliary body and 21 at the choroid level. In anterior localizations tumour extirpation was possible in the 2 cases through iridectomy and in only one case through cyclectomy. Anatomicopathologically, most cases presented mixed-type cells where prevailed the type B fusiform cells and epithelioid cells with big quantitative variations from one zone to another. The tumours detected in an incipient stage benefited from laser photocoagulation or application of CO60 and I125 radioactive disks. In advanced stages enucleation was practised preceded by 2 treatments of radiotherapy for the devitalization of tumorous cells and prevention of metastases.