Effect of Meteorological Conditions and Anthropogenic Factors on Air Concentrations of PM2.5 and PM10 Particulates on the Examples of the City of Kielce, Poland

The paper analyzes the influence of meteorological conditions (air temperature, wind speed, humidity, visibility) and anthropogenic factors (population in cities and in rural areas, road length, number of vehicles, emission of dusts and gases, coal consumption in industrial plants, number of air purification devices installed in industrial plants) on the concentration of PM2.5 and PM10 dusts in the air in the region of Kielce city in Poland. Spearman correlation coefficient was used to evaluate the relationship between the mentioned independent variables and air quality indicators. The calculated values of the correlation coefficient showed statistically significant relationships between air quality and the amount of installed air purification equipment in industrial plants. A statistically significant effect of the population in rural settlement units on the increase in air concentrations of PM2.5 and PM10 was also found, which proves the influence of the so-called low emission of pollutants on the air quality in the studied region. The analyses also revealed a statistically significant effect of road length on the decrease in PM2.5 and PM10 air content. This result indicates that a decrease in traffic intensity on particular road sections leads to an improvement in air quality. The analyses showed that despite the progressing anthropopression in the Kielce city region the air quality with respect to PM2.5 and PM10 content is improving. To verify the results obtained from statistical calculations, parametric models were also determined to predict PM2.5 and PM10 concentrations in the air, using the methods of Random Forests (RF), Boosted Trees (BT) and Support Vector Machines (SVM) for comparison purposes. The modelling results confirmed the conclusions that had been made based on previous statistical calculations

Synthesis and characterization of dextran esters as coating or matrix systems for oral delivery of drugs targeted to the colon

Different dextran esters with various degrees of substitution (1, 2 and 3) were synthesized by esterification reaction, with three acid anhydrides: acetic anhydride, propionic anhydride, and butyric anhydride, separately. These modified polysaccharides were characterized by FT-IR, 1H NMR and 13C NMR spectroscopies. Enzymatic degradation of biopolymers by dextranase was also studied. The polymers showing the best degradation profiles were chosen to design blended free films in combination with a polymethacrylate (Eudragit® RS 30D) as a sustained release system for targeting to the colon. These free films were evaluated by permeability of theophylline used as tracer in different in vitro media of the gastro intestinal tract, in presence or in absence of dextranase. From these studies, it was concluded that dextran esters having the lower degree of substitution and constituted of short carbohydrate chains showed the best and significant enzymatic degradation and could be used as a promising carrier for specific colon drug delivery system.Keywords: Colon-Specific Drug Delivery; Polysaccharides; Dextran; Dextranase; Dextran esters; Enzymatic Degradation; Eudragit® RS 30D; Sid-by-side diffusion cel

Patients’ Radiation Doses During the Implantation of Stents in Carotid, Renal, Iliac, Femoral and Popliteal Arteries

AbstractObjectives and DesignThe aim of the study was to document the radiation doses to patients during the implantation of stents in various arteries and to discuss potential reasons for prolongation of radiological procedures.Materials and MethodsMeasurements of air kerma (Gy) and dose–area product (Gy cm2) (DAP) were carried out simultaneously on a sample of 345 patients, who underwent different interventional radiological procedures involving angioplasty with stenting of 73 carotid (21.5%), 22 renal (6.5%), 160 iliac (45%), 63 femoral (18.6%) and 27 popliteal (7.9%) arteries.ResultsThe highest mean air kerma values for fluoroscopy and exposure were found for renal angioplasty (340 and 420 mGy, respectively). With regard to total DAP values, the highest were obtained for renal (148 Gy cm2) and iliac/The Inter-Society Consensus for Management of Peripheral Arterial Disease (TASC) II C (199 Gy cm2) stent implantation. The lowest values were for carotid (53 Gy cm2), iliac/TASC II A (6.3 Gy cm2) and femoral/TASC II A (53 Gy cm2) arteries. For 3.5% of the patients, the air kerma was between 1 and 1.5 Gy and for 1.5%, it was between 1.5 and 2 Gy.ConclusionsIn procedures performed on the arteries of the lower limbs, a significantly higher dose was received by patients with TASC II C lesions. With regard to the number of stents implanted, the total DAP value was 50% higher for simultaneous three-stent implantation than for one or two stents

Pulsating B-type stars in the young open cluster h Persei (NGC 869)

We announce the discovery of six Beta Cephei stars and many other variable stars in the young open cluster h Persei (NGC 869). The cluster seems to be very rich in variable B-type stars, similarly to its twin, Chi Persei (NGC 884).Comment: 5 pages, 5 figures, Proc. HELAS-II conference, Goettingen, 20-24 August 200

Controlling spontaneous chirality in achiral materials : liquid crystal oligomers and the heliconical twist-bend nematic phase

Peer reviewedPublisher PD