Dipyridamole-loaded biodegradable PLA nanoplatforms as coatings for cardiovascular stents.

Cardiovascular stents are commonly used for the treatment of cardiovascular diseases that in developed societies are the most frequent causes of mortality and morbidity. In recent years, thorough research and development of drug-eluting stents has been done, with emphasis on coronary stenting to avoid the most common complication, in-stent thrombosis. Dipyridamole (DPM) is a medication that inhibits blood clot formation. Drug delivery nanoplatforms consisting of biodegradable polymers can be fabricated via electrospinning deposition, known for its cost-effective and versatile advantages, that produces fibrous scaffolds that are able to sustain and control drug release. A novel drug delivery nanosystem of polylactic acid fibrous scaffold loaded with the anti-platelet drug DPM was fabricated by electrospinning as coating for cardiovascular stents. The surface morphology and topography that were evaluated via atomic force microscopy, scanning electron microscopy and optical microscopy, were found to be good and suitable for tissue engineering. Contact angle measurements established the hydrophobic behavior of these fibrous nanoplatforms. Drug-release kinetics and degradation studies were conducted and revealed a sustained and controllable release of DPM, through this fibrous matrix over time. Finally, cytotoxicity studies took place to evaluate the cytocompatibility of the scaffold that confirmed its compatible behavior. The successful performance of this nanoplatform can lead to it being a valuable tool for atherosclerosis treatment.

Vitrification of incinerated tannery sludge in silicate matrices for chromium stabilization.

The vitrification process was applied for the stabilization and solidification of a rich in chromium ash that was the by-product of incineration of tannery sludge. Six different batch compositions were produced, based on silica as the glass former and sodium and calcium oxides as flux agents. As-vitrified products (monoliths) were either composed of silicate matrices with separated from the melt Eskolaite (Cr2O3) crystallites or were homogeneous glasses (in one case). All as-vitrified products were thermally treated in order to transform them to partially crystallized, i.e. devitrified products. Devitrification is an important part of the work since studying the transformation of the initial as-vitrified products into glass-ceramics with better properties could result to stabilized products with potential added value. The devitrified products were diversified by the effective crystallization mode and separated crystal phase composition. These variations originated from differences in: (a) batch composition of the initial as-vitrified products and (b) thermal treatment conditions. In devitrified products crystallization led to the separation of Devitrite (Na2Ca3Si6O16), Combeite (Na4Ca4Si6O18) and Wollastonite (CaSiO3) crystalline phases, while Eskolaite crystallites were not affected by thermal treatment. Leaching test results revealed that chromium was successfully stabilized inside the as-vitrified monoliths. Devitrification impairs chromium stabilization, only in the case where the initial as-vitrified product was a homogeneous glass. In all other cases, devitrification did not affect successful chromium stabilization.

Severe particulate pollution from the deposition practices of the primary materials of a cement plant.

Global cement production has increased twofold during the last decade. This increase has been accompanied by the installation of many new plants, especially in Southeast Asia. Although various aspects of pollution related to cement production have been reported, the impact of primary material deposition practices on ambient air quality has not yet been studied. In this study, we show that deposition practices can have a very serious impact on levels of ambient aerosols, far larger than other cement production-related impacts. Analyses of ambient particulates sampled near a cement plant show 1.3-30.4 mg/m(3) total suspended particulates in the air and concentrations of particles with a diameter of 10 µm or less at 0.04-3 mg/m(3). These concentrations are very high and seriously exceed air quality standards. We unequivocally attribute these levels to outdoor deposition of cement primary materials, especially clinker, using scanning electron microscopy/energy-dispersive X-ray spectroscopy. We also used satellite-derived aerosol optical depth maps over the area of study to estimate the extent of the spatial impact. The satellite data indicate a 33% decrease in aerosol optical depth during a 10-year period, possibly due to changing primary material deposition practices. Although the in situ sampling was performed in one location, primary materials used in cement production are common in all parts of the world and have not changed significantly over the last decades. Hence, the results reported here demonstrate the dominant impact of deposition practices on aerosol levels near cement plants.

Cu-Zn powders as potential Cr(VI) adsorbents for drinking water.

This work examines the possibility of applying CuZn alloys as a reducing medium for the efficient removal of hexavalent chromium from drinking water. In an effort to develop a route for producing powders of CuZn alloys under mild conditions and investigate the optimum composition for such application, a series of alloys in the form of powders were prepared, by a sequence of Cu and Zn ball-milling and low temperature annealing. Batch Cr(VI) removal tests, performed to evaluate and compare the efficiency of the products under typical natural water parameters (pH 7 and natural-like water), indicated that the best performing material have a composition around 50 wt% Cu. The dominant reduction mechanisms are both the corrosion of the alloy surface and the electron transfer to the solution. The behavior of granulated CuZn media was tested in rapid-scale column tests using the commercial KDF which verified the high potential of CuZn alloys in Cr(VI) removal. Nevertheless, Cu and Zn leaching problems should be also considered.

Juxtacortical clavicular chondrosarcoma: diagnostic dilemmas: case report and review of literature.

Juxtacortical chondrosarcoma is a rare primary malignant cartilaginous tumor accounting for 0.2% of all bone tumors. Wide surgical resection is the treatment of choice for juxtacortical chondrosarcomas. Accurate preoperative diagnosis is important in ensuring appropriate management, staging, and treatment of the patient. A combination of radiographs, three-dimensional imaging with computerized tomography (CT) scan and magnetic resonance imaging (MRI) can typically allow accurate diagnosis of juxtacortical chondrosarcomas. Bone scan and chest x-ray or CT chest scans are indicated for appropriate staging of the patient. Pet scan, ultrasound, bone scan, etc. are not typically needed for the diagnosis. Certainly, pulmonary imaging and bone scan are required for staging and could be commented upon.

Structural, microchemistry, and hydrogenation properties of TiMn0.4Fe0.2V0.4, TiMn0.1Fe0.2V0.7 and Ti0.4Zr0.6Mn0.4Fe0.2V0.4 metal hydrides.

In this work, TiFe-based alloys have been developed according to the stoichiometry Ti1-xAx Fe1-yBy (A [triple bond] Zr; B [triple bond] Mn, V). The hydrogen solubility properties have been investigated to develop dynamic hydrides of Ti-based alloys for hydrogen storage applications. The hydrogenation behavior of these alloys has been studied, and their hydrogen storage capacities and kinetics have been evaluated. Several activation modes, including activation at high temperatures under hydrogen pressure, have been attempted for the as-milled powders. In order to clarify the structural/microstructural characteristics, and chemical composition before and after hydrogenation, X-Ray Diffraction (XRD), EDAX-Mapping Analysis and Scanning Electron Microscopy (SEM), have been carried out for the samples. Modeling of the isotherms has been performed by using MATLAB programming. The maximum gravimetric density of 4.3 wt%, has been obtained on the sample with the BCC main phase. The calculated enthalpy of reaction (deltaH) is found to be about 4 kJ/mol.

Time trends of female breast cancer mortality in Greece during 1980-2005: a population based study.

BACKGROUND: Changes in female breast cancer mortality trends have been observed in recent years in western countries. The aim of the present study was to analyse breast cancer mortality in Greece, between 1980 and 2005. METHODS: Time trends of breast cancer mortality were calculated per 100,000 women in the whole female population of Greece, in different age groups, and in different areas of the country. Mortality data and population age distribution were provided by the National Statistical Service of Greece. RESULTS: Overall, female breast cancer mortality in Greece had an increasing trend during 1980-2005. Subgroup analysis according to age showed that this increase was confined to women older than 70 years. In contrast, a mild decrease was noted after the mid-1990s in women 40-69 years old. There were no notable regional differences in breast cancer mortality. CONCLUSIONS: The increasing trend of breast cancer mortality in women aged 70 years and older could be attributed to limited use of secondary prevention methods and rare administration of systemic cytotoxic chemotherapy in these women. In contrast, implementation of these strategies could explain the recent reduction of breast cancer mortality in younger age groups.

Late postoperative opacification of hydrogel intraocular lenses: analysis of 13 explanted lenses.

PURPOSE: We report the clinical, morphological, and ultrastructural findings of 13 consecutively explanted opacified Hydroview(R) (hydrogel) intraocular lenses (IOLs). Our purpose was to provide a comprehensive account on the possible factors involved in late postoperative opacification of these IOLs. PATIENTS AND METHODS: Thirteen consecutive opacified hydrogel IOLs (Hydroview H 60 M, Bausch & Lomb) were explanted due to the significant visual impairment they caused. The IOLs underwent macroscopical examination, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and electrophoresis for protein detection. Three unused control Hydroview IOLs served for comparison. RESULTS: Macroscopical examination showed a diffuse or localized grey-whitish opacification within the IOL optic. TEM confirmed the presence of lesions inside the optic in all the explanted IOLs and revealed 3 patterns of deep deposits: a) diffuse, thick, granular, electron-dense ones; b) small, thin, lattice-like ones, with prominent electron-lucent areas; and c) elongated electron-dense formations surrounded by electron-lucent halos. SEM showed surface deposits on four IOLs. EDS revealed oxygen and carbon in all IOLs and documented calcium, phosphorus, silicon and/or iron in the deposits. Two of the patients with iron in their IOLs had eye surgery prior to their phacoemulsification. Iron correlated well with the second TEM pattern of deep lesions, whereas calcium with the third TEM pattern. No protein bands were detected on electrophoresis. Control lenses did not show any ultrastructural or chemical abnormality. CONCLUSIONS: The present study supports the presence of chemical alterations inside the polymer of the optic in late postoperative opacification of Hydroview IOLs. This opacification does not follow a unique pathway but may present under different ultrastructular patterns depending on the responsible factors. Mechanical stress during surgery may initiate a sequence of events where ions such as calcium, phosphorus, silicon, and/or iron, participate in a biochemical cascade that leads to gradual alteration of the polymer network. Intraocular inflammation due to previous operation may be a factor inducing opacification through increase of iron-binding capacity in the aqueous humour. Calcification accounts only partially for the opacification noted in this type of IOL.

Combined FTIR and SEM-EDS study of Bi2O3 doped ZnO-SnO2 ceramics.

The effects of Bi(2)O(3) addition on the phase composition, microstructure and optical properties of ZnO-SnO(2) ceramics were investigated. Starting powders of ZnO and SnO(2) were mixed in the molar ratio 2:1. After adding Bi(2)O(3) (1.0 mol.%) this mixture was mechanically activated for 10 min in a planetary ball mill, uniaxially pressed and sintered at 1300 degrees C for 2 h. Far-infrared reflection spectra were measured (100-1000 cm(-1)). To investigate the occurred differences in FTIR spectra, the Bi(2)O(3)-doped sample was examined more carefully with a Perkin-Elmer FTIR spectrometer (Perkin Elmer, Waltham, MA, USA) connected with a Perkin-Elmer FTIR microscope and itemized points of interest were also studied with SEM-EDS.

Infrared and Raman vibrational spectroscopies reveal the palette of frescos found in the medieval monastery of Karaach Teke.

Vibrational spectroscopy is applied on samples obtained from the excavation area of the medieval Monastery (10th century) of Karaach-Teke in Bulgaria. The results of the corresponding study, reveal the type of materials used for the creation of the wall-paintings and give evidence of Byzantine influence, a fact that further supports the well known impact of Byzantium on the technology and thematic-aesthetic features of iconography in Bulgaria during this era. In addition, the complementarity of FTIR and micro-Raman spectroscopies in the identification of pigments is indicated.

[Congenital hemiplegia. A disease with manifold problems]. / Kongenitale Hemiplegie. Eine Krankheit mit vielen Problemen.

Congenital hemiplegia, defined as unilateral motor disability, is the hemiplegic type of cerebral palsy. The prevalence of congenital hemiplegia is estimated to be about 0.41-0.79/1000 live births. We examined 223 children (122 boys and 101 girls) suffering from congenital hemiplegia at the age of 3 months to 12 years. Mild hemiplegia was found in 31%, a moderate form in 48%, and a severe form in 21%. The upper limb was affected in more than half of the patients, only the lower extremity in one third, and both upper and lower limbs in 20%. Electroencephalographic abnormalities were found in 75.8% of the patients. The most frequent type of epilepsy was complex partial seizures (33%). Severity of the motor handicap, grade of EEG abnormalities, and the prevalence of epilepsy showed a significant correlation. The magnitude of the lesions in neuroimaging directly correlated with these three clinical variables, particularly in children with cortical and subcortical defects (84.2%). Strabismus was the most common visual impairment (17%), while hearing impairment was found in 8% of the patients. Of them, 38.3% showed no cognitive deficits, while those with severe congenital hemiplegia were found to have a lower intelligence quotient.

Morphological features and apoptosis in the left internal thoracic artery grafts before implantation.

AIM: A small number of left internal thoracic artery (LITA) grafts are occluded at 3 years after the operation or show more than 50% stenosis of the lumen. The purpose of this study is to examine factors related to the morphology of the wall and to the function of the cell population of LITA grafts before implantation, in order to evaluate their quality and the viability, in a follow-up examination. METHODS: Fifteen LITA grafts were examined with light microscopy, for their morphology, endothelial cell coverage, apoptosis and cell proliferation, scanning electron microscopy and transmission electron microscopy. RESULTS: Increase of the thickness of the intima (14.21+/-1.28 mm), mean thickness of media 160.37+/-11.97 mm, detachment of intima from media, presence of foam cells in the media, low endothelial coverage (40.638+/-16.864), increase of apoptosis in intima (46.38+/-13.46), sub-intima (29.3+/-8.54), media (34.91+/-6.05) and adventitia (40.21+/-5.36), blood cells penetration of the intima through disruptions between endothelial cells are findings of LITA grafts before implantation. Cell proliferation was not detected in the wall of any graft. Follow-up examination 6 months and 2.5 years after the operation showed normal function of LITA grafts. CONCLUSIONS: Besides of the wall injury and the initiated atherosclerotic lesions, LITA grafts are well functioning at the time of the follow-up examination. Maybe our findings are related to the later occlusion of the referred in the literature small number of LITA grafts.

[Indications for intermittent diazepam prophylaxis in febrile seizures]. / Indikation der intermittierenden Diazepamprophylaxe bei Fieberkrämpfen.

BACKGROUND: In a prospective controlled study we evaluated the efficacy of intermittent diazepam prophylaxis in the recurrence rate of febrile seizures (FS). PATIENTS: A total of 139 children aged between 6 and 36 months, who had a first FS, were enrolled in the study and were randomly allocated to two groups: group (A) that received diazepam prophylaxis and group (B) without prophylaxis. METHODS: All children were followed up for at least 3 years after their first FS. The prophylaxis group (n = 68) received rectal diazepam the first two days of a febrile illness, whenever the temperature was > 38 degrees C (0.33 mg/kg every 8 h on the first day, and 0.33 mg/kg every 12 h on the second day of fever, max. dosage 7.5 mg). The no-prophylaxis group (n = 71) did not receive any prophylaxis at all. Each group was stratified to low, intermediate and high risk subgroups according to the following clinical data: age at the first febrile seizure

Effect of heat sterilization on surface characteristics and microstructure of Mani NRT rotary nickel-titanium instruments.

AIM: To evaluate the effect of repeated dry heat sterilization on surface characteristics and microstructure of Mani nickel-titanium rotary instruments. METHODOLOGY: Thirty-three new Mani NRT instruments, size 30, taper 0.04 and 25 mm in length were examined. Twenty-seven instruments were divided into three groups for surface characterization by scanning electron microscopy (SEM). In the first group (n = 3), instruments were examined in the 'as-received' condition and after they had been subjected to 11 sterilization cycles. In the second and third subgroups (n = 12), 12 instruments were prepared for cross-section and a further 12 for longitudinal sectional analysis and evaluated in subgroups of three, after 0, 1, 6 and 11 sterilization cycles. The remaining six instruments were analysed with differential scanning calorimetry (DSC), three in the 'as-received' condition and three after being subjected to 11 cycles of sterilization. RESULTS: Scanning electron microscopy observations indicated the presence of debris, pitting and deep milling marks in both new and sterilized files. After 11 sterilization cycles, debris remained and surface roughness was increased significantly (P = 0.05). DSC analyses showed that the specimens in the 'as-received' condition and after 11 sterilization cycles were in the austenite phase or a mixture of austenite and R-phase at 37 degrees C. CONCLUSIONS: The machining defects and structural imperfections of new Mani instruments are indicative of the difficulty in manufacturing nickel-titanium endodontic instruments. DSC measurements suggest that Mani instruments are capable of superelastic behaviour under clinical conditions.

Apatite formation on dental ceramics modified by a bioactive glass.

Restorative dental materials are considered biocompatible without exhibiting any bioactive behaviour. The aim of this study was the investigation of surface structure changes on conventional dental ceramics used in metal-ceramic restorations modified by a bioactive glass, after immersion in SBF for various time periods. Bioactive glass powder was mixed with porcelain powder with three different weight ratios: 1:1, 1:2, and 2:1. The two powders were mixed with porcelain modelling liquid and the mixture was transferred and spread on the surface of pre-fabricated ceramic disks. Coated ceramic specimens after being exposed to a specific thermal cycle as it is recommended for dental ceramics were soaked in Simulated Body Fluid (SBF) at 37 degrees C for various periods of time. After soaking, specimens were studied using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Results revealed the development of a non-stoichiometric, biological apatite layer on their surface after exposure in SBF for several time periods. The onset of apatite-layer formation is directly dependent on the amount of bioglass in the coating and its thickness reduces within the specimens of the same bioactive glass-porcelain proportion with time, reaching an average thickness of 15 microm at the longest immersion time, for all the specimens.

Vitrification of lead-rich solid ashes from incineration of hazardous industrial wastes.

Lead-rich solid industrial wastes were vitrified by the addition of glass formers in various concentrations, to produce non-toxic vitreous stabilized products that can be freely disposed or used as construction materials. Toxicity of both the as-received industrial solid waste and the stabilized products was determined using standard leaching test procedures. The chemically stable vitreous products were subjected to thermal annealing in order to investigate the extent of crystal separation that could occur during cooling of large pieces of glass. Leaching tests were repeated to investigate the relation between annealing process and chemical stability. X-ray, scanning and transmission electron microscopy techniques were employed to identify the microstructure of stabilized products before and after thermal treatment. Relation between synthesis and processing, chemical stability and microstructure was investigated.

Folate and breast cancer: the role of polymorphisms in methylenetetrahydrofolate reductase (MTHFR).

Evidence is growing that low folate status may be a factor in the aetiology of several cancers, including breast cancer. The methylenetetrahydrofolate reductase gene (MTHFR), which has a key role in folate metabolism, is polymorphic. We report a case-control study of two functional polymorphisms in MTHFR, dietary folate intake and breast cancer. Sixty-two cases with invasive breast cancer and sixty-six general practice controls participated. Women reporting the highest dietary folate intake had non-significantly reduced breast cancer risk (odds ratio (OR) = 0.49, 95% confidence interval (CI) 0.20-1.20). Risk was significantly lower for the 1298CC genotype compared to AA (OR = 0.24, 95% CI 0.06-0.97). Relative to compound wild-type subjects, compound heterozygotes had moderately reduced risk (OR = 0.47, 95% CI 0.11-1.92) and homozygote variants (677TT and/or 1298CC) greater reduced risk (OR = 0.26, 95% CI 0.07-0.96); the trend was statistically significant. Patterns in risk with regard to genotype and folate combinations are broadly similar those reported for colorectal neoplasia. The roles of MTHFR and folate in breast cancer aetiology are likely to be complex.

Ochre-differentiation through micro-Raman and micro-FTIR spectroscopies: application on wall paintings at Meteora and Mount Athos, Greece.

The most widely-used inorganic pigments of Byzantine and post-Byzantine hagiography are earth pigments called ochres such as, red and yellow ochres, limonite, goethite, raw and burnt sienna, caput mortuum and hematite. The present experimental work proposes a technique of differentiation that allows one to distinguish among all the different kinds of iron oxides, thereby providing a better understanding of the painting technique used on portable icons and wall paintings. The ratios between the main spectroscopic peaks, attributable to the major components usually present in ochres, were calculated and compared, one against the another, from the spectra obtained through micro-Raman spectroscopy. Elementary composition is also revealed through a scanning electron microscopy (SEM) analysis. The possibility for detailed study on a particular Byzantine ochre palette can thus be performed based on the small differences in its nature and composition. These differences can first be observed and then measured among all of the natural earth pigments, through microRaman and microFTIR spectroscopies.

DNA-dependent RNA polymerase from T8 Guerin tumor.

DNA-dependent RNA polymerases from nuclei of T8 Guerin tumor were studied. Two enzymes were purified several hundred times by the use of ammonium sulfate precipitation, DEAE-cellulose and phosphocellulose chromatography. One of them belongs to A(I) RNA polymerases and the second to B(II) as was established from their metal and ionic strength requirements. activity in the presence of native and denatured DNA and the resistance to a-amanitin inhibition. The quantity of class A enzyme was increased compared to B, a fact observed with most neoplastic tissues so far studied. This increase of the polymerase responsible for ribosomal RNA synthesis could probably be related to malignant transformation in animals.