Mud and burnt Roman bricks from Romula.

Sesquipedalian mud and burnt bricks (second to third century AD) were excavated from the Roman city of Romula located in the Lower Danube Region (Olt county, Romania). Along with local soils, bricks are investigated by petrographic analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), electron microscopy (SEM/EDX), X-ray microtomography (XRT), thermal analysis (DTA-TG), MÓ§ssbauer spectroscopy, magnetometry, colorimetry, and mechanical properties assessment. The results correlate well with each other, being useful for conservation/restoration purposes and as reference data for other ceramic materials. Remarkably, our analysis and comparison with literature data indicate possible control and wise optimization by the ancient brickmakers through the recipe, design (size, shape, and micro/macrostructure), and technology of the desired physical-chemical-mechanical properties. We discuss the Roman bricks as materials that can adapt to external factors, similar, to some extent, to modern "smart" or "intelligent" materials. These features can explain their outstanding durability to changes of weather/climate and mechanical load.

Results from time integrated measurements of indoor radon, thoron and their decay product concentrations in schools in the Republic of Macedonia.

As part of a survey on concentrations of radon, thoron and their decay products in different indoor environments of the Balkan region involving international collaboration, measurements were performed in 43 schools from 5 municipalities of the Republic of Macedonia. The time-integrated radon and thoron gas concentrations (CRn and CTn) were measured by CR-39 (placed in chambers with different diffusion barriers), whereas the equilibrium equivalent radon and thoron concentrations (EERC and EETC) were measured using direct radon-thoron progeny sensors consisting of LR-115 nuclear track detectors. The detectors were deployed at a distance of at least 0.5 m from the walls as well as far away from the windows and doors in order to obtain more representative samples of air from the breathing zone; detectors were exposed over a 3-month period (March-May 2012). The geometric mean (GM) values [and geometric standard deviations (GSDs)] of CRn, CTn, EERC and EETC were 76 (1.7), 12 (2.3), 27 (1.4) and 0.75 Bq m(-3) (2.5), respectively. The equilibrium factors between radon and its decay products (FRn) and thoron and its decay products (FTn (>0.5 m)) were evaluated: FRn ranged between 0.10 and 0.84 and FTn (>0.5 m) ranged between 0.003 and 0.998 with GMs (and GSDs) equal to 0.36 (1.7) and 0.07 (3.4), respectively.

Preliminary results regarding the first map of residential radon in some regions in Romania.

Radon represents the most important contribution of population exposure to natural ionising radiation. This article presents the first indoor radon map in some regions of Romania based on 883 surveyed buildings in the Stei-BaiTa radon-prone region and 864 in other regions of Romania. Indoor radon measurements were performed in the last 10 y by using CR-39 nuclear track detectors exposed for 3-12 months on ground floor levels of dwellings. Excluding the Stei-BaiTa radon-prone region, an average indoor radon concentration of 126 Bq m(-3) was calculated for Romanian houses. In the Stei-BaiTa radon-prone area, the average indoor concentration was 292 Bq m(-3). About 21 % of the investigated dwellings in the Stei-BaiTa radon-prone region exceed the threshold of 400 Bq m(-3), while 5 % of the dwellings in other areas of Romania exceed the same threshold. As expected, indoor radon concentration is not uniformly distributed throughout Romania. The map shows a high variability among surveyed regions, mainly due to the differences in geology. The radon emanation rate is substantially influenced by the soil characteristics, such as the soil permeability and soil gas radon concentration. Since higher permeability enables the increased migration of soil gas and radon from the soil into the building, elevated levels of indoor radon can be expected in more permeable soil environments.

Deposition of radon progeny on skin surfaces and resulting radiation doses in radon therapy.

In the Gastein valley, Austria, radon-rich thermal water and air have been used for decades for the treatment of various diseases. To explore the exposure pathway of radon progeny adsorbed to the skin, progeny activities on the skin of patients exposed to thermal water (in a bathtub) and hot vapour (in a vapour chamber) were measured by alpha spectrometry. Average total alpha activities on the patients' skin varied from 1.2 to 4.1 Bq/cm(2) in the bathtub, and from 1.1 to 2.6 Bq/cm(2) in the vapour bath. Water pH-value and ion concentration did affect radon progeny adsorption on the skin, whereas skin greasiness and blood circulation did not. Measurements of the penetration of deposited radon progeny into the skin revealed a roughly exponential activity distribution in the upper layers of the skin. Based on the radon progeny surface activity concentrations and their depth distributions, equivalent doses to different layers of the skin, in particular to the Langerhans cells located in the epidermis, ranged from 0.12 mSv in the thermal bath to 0.33 mSv in the vapour bath, exceeding equivalent doses to the inner organs (kidneys) by inhaled radon and progeny by about a factor 3, except for the lung, which receives the highest doses via inhalation. These results suggest that radon progeny attachment on skin surfaces may play a major role in the dosimetry for both thermal water and hot vapour treatment schemes.

Frequency of antibodies to the cholesterol transport protein apolipoprotein A1 in patients with SLE.

In examining reasons for premature atherosclerosis in systemic lupus erythematosus (SLE), we previously reported low levels of the cholesterol transport protein apolipoprotein A1 (apoA1) in these patients, and specific antibodies to purified apoA1 were identified in the sera of 5 out of 30 lupus patients. The current study was initiated to determine whether these antibodies are common in lupus patients. 520 serum samples from 175 patients with SLE or primary antiphospholipid syndrome (PAPS) were tested for antibodies to purified apoA1. Positive sera were retested for binding to apolipoprotein incorporated into reconstructed nascent or mature high-density lipoprotein (HDL). Autoantibodies to apoA1 were found in 32.5% of patients with SLE and 22.9% of patients with PAPS, associated with the presence of aPL (anti-beta2 glycoprotein-1, anti-beta2 GP1) antibodies. When reconstructed, nascent and mature HDL molecules were compared as antigen-containing environments, positive sera reacted best to apoA1 embedded in mature HDL molecules. This report confirms the high prevalence of antibodies to apoA1 in patients with systemic lupus and suggests a high affinity of these antibodies for mature HDL.

Inhibition of methotrexate-induced rheumatoid nodulosis by colchicine: evidence from an in vitro model and regression in 7 of 14 patients.

Methotrexate is one of the most effective and widely used medications in the treatment of rheumatoid arthritis. One poorly understood side effect of methotrexate is increased rheumatoid nodule formation, a phenomenon which has been reported to occur in some patients despite suppression of synovial inflammation. Using an in vitro model of nodulosis, induction of monocyte differentiation into multinucleated giant cells, we previously found that methotrexate promotes this inflammatory response by a mechanism dependent on adenosine A1 receptor stimulation. In the current study, we tested the effects of an A1 signal inhibitor, the commonly available anti-inflammatory medication colchicine, and found that it markedly inhibited nodulosis in vitro as well as in seven of fourteen patients in a clinical series.

The polar behavior of frog photoreceptors.

It was observed that the outer segments of the frog visual rods orient along the direction of an externally applied static electric field. The orientation ability of the rod outer segments seems to be fuelled by the cell energy. The dipolar moment per rod was determined using a model which considers rod outer segments as rigid dipoles interacting with the electric field in a viscous medium. The mean dipolar charge of ROS was determined as being (2.10 +/- 0.17).10(-14)C.

Studies concerning ATP dynamics in essential hypertension.

The use of Beckmann LS-7000 liquid scintillation spectrometer enabled us to develop a rapid and reproducible technique for the enzymatic microdosage of ATP by means of the bioluminescence reaction of the luciferin-luciferase system from the firefly. Changes of ATP concentration in the plasma, erythrocytes and cerebrospinal fluid of the hypertensive subjects as compared to the control ones have been revealed by means of this method. According to our results ATP concentration significantly increases in the plasma and cerebrospinal fluid and slightly modifies in the erythrocytes of the hypertensive as compared with control subjects. Correlation of data concerning the variation of ATP distribution in the different compartments (plasma, erythrocytes, cerebrospinal fluid) with those related to Na and K content in hypertensive and control subjects seems to be useful for some remarks on the molecular mechanisms in the essential hypertension.

On the electrical conductivity of rhodopsin solutions.

Measurements were made on the conductivity of digitonin extracts of frog rhodopsin with and without previous light exposure. The light-dark difference in conductivity is observed at low concentrations of rhodopsin and detergent.

Theoretical and experimental aspects of the possible role of calcium in some physiological and physiopathological phenomena.

The role played by calcium in some physiological and physiopathological phenomena is examined in the light of the intervention of calmodulin as a calcium regulatory protein. Data are presented concerning the interaction of some heavy metal ions with the erythrocyte membrane with special references to the modifications of calcium dynamics by Pb2. The results are discussed considering the interaction of heavy metal ions with the proteins of erythrocyte cytoskeleton and the role played by calmodulin in this interaction.