Structure and magnetic properties of nanocrystalline Fe-Mo alloys prepared by mechanosynthesis

Nanocrystalline samples of Fe8 0 Mo 20 and Fe50 Mo 50 alloys were prepared by the mechanical milling method. The structure, lattice parameters, and crystallite size were determined by the X -ray diffraction . The magnetic properties of the milled products were determined by the M ossbauer spectroscopy . It was observed that in the case of the Fe80 Mo 20 alloy a solid solutio n of Mo in Fe was formed with the lattice parameters of Fe increasing from 0.28659 nm to 0.29240 nm and the crystalli te size decreasing from 250 nm to 20 nm. In the case of the Fe50 Mo 50 alloy there were no clear changes in values of the lattice parameters of Fe and Mo during the millin g pro cess, but the crystallite size decreased from 200 nm to 15 nm. M ossbauer spectra revealed different magnetic phases in the mechanosynthesized Fe-Mo samples. In the case of the Fe80 Mo 20 alloy , the spectrum for the milled mi xture indicated the formation of a solid solution. In contrast, for the Fe50 Mo50 the spectrum indicated the disappeara ce of the ferromagnetic phase

Distribution of microelements in human articular cartilage : initial report

The aim of this study was evaluation of distribution microelements in human articular cartilage and to determine factors influencing it. The following elements were taken under consideration: Mg, Ca, Zn, Fe, Pb. Their concentration was assessed in the articular cartilage harvested from the loaded an unloaded area of human femoral heads. Initial results indicate that mechanical loadings are one of the important factors influencing distribution of microelements in human articular cartilage

Distribution of heavy metals in sediments of Dobczyce reservoir

Osady denne stanowią istotny składnik środowiska wodnego, akumulując składniki mineralne, w tym metale ciężkie. Zbiornik Dobczycki, będąc rezerwuarem wody pitnej dla aglomeracji krakowskiej, spełnia bardzo ważną funkcję gospodarczą. W badaniach osadów dennych Zbiornika Dobczyckiego wykonano analizę wierzchniej ich warstwy w 17 punktach pomiarowych. Pozwoliło to na opisanie dystrybucji metali w czaszy zbiornika oraz ocenę czynników warunkujących tę dystrybucję. Analizę wykonano dwoma metodami: metodą atomowej spektrometrii absorpcyjnej oraz metodą PIXE. Stwierdzono, z wykorzystaniem narzędzi statystycznych, że ze względu na stężenie metali, punkty poboru próbek można podzielić na dwie grupy: leżące poza dawnym nurtem rzeki Raby (niższe stężenia metali ciężkich) oraz usytuowane w dawnym nurcie rzeki (wyższe stężenia). Odpowiada to zmieniającym się właściwościom sorpcyjnym osadów, zależnym m.in. od uziarnienia, składu chemicznego i mineralnego oraz zawartości materii organicznej. Zastosowanie metody PIXE umożliwiło wykonanie wielopierwiastkowej analizy składu bez wstępnej procedury przygotowania próbek, z wystarczającą czułością oznaczeń, lecz mniejszą precyzją niż metoda ASA. Metody te mogą być komplementarne z punktu widzenia potrzeb analiz środowiskowych.Sediments constitute important part of water systems, accumulating mineral compounds, such as heavy metals. Dobczyce Reservoir, being the main drinking water source for the city of Krakow, is important from the economical point of view. In the present research, analysis of elemental composition of sediment samples (upper 10 cm layer) in 17 sampling points was performed. It enabled us to analyse distribution of analysis of elements in Dobczyce Reservoir and to assess what factors influenced that distribution. The analysis was carried out by means of two instrumental methods, namely PIXE and ASA. Based on the statistical analysis of the results, it was found that all the sampling points could be divided into two groups – one situated out of the Raba river current (characterized by lower concentration of elements) and the other along the river current (higher concentration of elements). Such a division results from the differences in chemical and mineralogical composition of sediments as well as from their organic matter content and physical properties. The use of PIXE method makes it possible to analyze sediments in a multielemental mode without sample pretreatment, obtaining satisfactory sensitivity but less precision than with the use of AAS method. Both methods could be considered as complementary in environmental analysis

Partitioning of chromium (VI) and chromium (III) between dissolved and colloidal forms in a stream and reservoir contaminated with tannery waste water

Environmental fate of chromium rejected from tannery wastewater to the Dunajec River (southern Poland) was investigated using separation with tangential flow filtration followed by measurements with Cathodic Adsorptive Stripping Voltammetry (CAdSV) and ICP-MS. Virtually all Cr(VI) was found in the dissolved fraction ($<$1 kDa). Thus form was present at low concentrations. Cr(III) was rapidly transferred from dissolved and low molecular weight colloidal fractions to particles and high molecular weight colloids and thus scavenged from the water column of the Czorsztyn Reservoir to the sediments. The possibility of Cr remobilization via oxidation of Cr(III) in the presence of freshly precipitated Mn-oxides in water or at the water-sediment interface needs further investigation.

Rivaroxaban with or without aspirin in stable cardiovascular disease

BACKGROUND: We evaluated whether rivaroxaban alone or in combination with aspirin would be more effective than aspirin alone for secondary cardiovascular prevention. METHODS: In this double-blind trial, we randomly assigned 27,395 participants with stable atherosclerotic vascular disease to receive rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily), rivaroxaban (5 mg twice daily), or aspirin (100 mg once daily). The primary outcome was a composite of cardiovascular death, stroke, or myocardial infarction. The study was stopped for superiority of the rivaroxaban-plus-aspirin group after a mean follow-up of 23 months. RESULTS: The primary outcome occurred in fewer patients in the rivaroxaban-plus-aspirin group than in the aspirin-alone group (379 patients [4.1%] vs. 496 patients [5.4%]; hazard ratio, 0.76; 95% confidence interval [CI], 0.66 to 0.86; P<0.001; z=−4.126), but major bleeding events occurred in more patients in the rivaroxaban-plus-aspirin group (288 patients [3.1%] vs. 170 patients [1.9%]; hazard ratio, 1.70; 95% CI, 1.40 to 2.05; P<0.001). There was no significant difference in intracranial or fatal bleeding between these two groups. There were 313 deaths (3.4%) in the rivaroxaban-plus-aspirin group as compared with 378 (4.1%) in the aspirin-alone group (hazard ratio, 0.82; 95% CI, 0.71 to 0.96; P=0.01; threshold P value for significance, 0.0025). The primary outcome did not occur in significantly fewer patients in the rivaroxaban-alone group than in the aspirin-alone group, but major bleeding events occurred in more patients in the rivaroxaban-alone group. CONCLUSIONS: Among patients with stable atherosclerotic vascular disease, those assigned to rivaroxaban (2.5 mg twice daily) plus aspirin had better cardiovascular outcomes and more major bleeding events than those assigned to aspirin alone. Rivaroxaban (5 mg twice daily) alone did not result in better cardiovascular outcomes than aspirin alone and resulted in more major bleeding events