Addition of N -centered radicals to C=C bonds or insertion into C–H bonds is well represented in the literature. These reactions have a tremendous significance, because they afford polyfunctionalized organic molecules. Despite the tetrahydroisoquinoline (THIQ) moiety widely occurring in natural biologically active compounds, N -unsubstituted THIQs as a source of N -centered radicals are not studied. Herein, we report a photocatalytic reaction between tetrahydroisoquinoline and chalcones that gives N -fused pyrroles—1,3-disubstituted-5,6-dihydropyrrolo[2,1-a]isoquinolines (DHPIQ). The mechanism includes at least two photocatalytic events in one pot: (1) C–N bond formation; (2) C–C bond formation. In this process potassium poly(heptazine imide) is used as a visible light active heterogeneous and recyclable photocatalyst. Fifteen N -fused pyrroles are reported with 65–90% isolated yield. DHPIQs are characterized by UV–vis and fluorescence spectroscopy, while the fluorescence quantum efficiency of fluorinated DHPIQs reaches 24%.

Background: Cardiac implantable electronic devices (CIED) are very rare in the pediatric population. In children with CIED, transvenous lead extraction (TLE) is often necessary. The course and effects of TLE in children are different than in adults. Thus, this study determined the differences and specific characteristics of TLE in children vs. adults. Methods and Results:A post hoc analysis of TLE data in 63 children (age ≤18 years) and 2,659 adults (age ≥40 years) was performed. The 2 groups were compared with respect to risk factors, procedure complexity, and effectiveness. In children, the predominant pacing mode was a single chamber ventricular system and lead dysfunction was the main indication for lead extraction. The mean implant duration before TLE was longer in children (P=0.03), but the dwell time of the oldest extracted lead did not differ significantly between adults and children. The duration (P=0.006) and mean extraction time per lead (P<0.001) were longer in children, with more technical difficulties during TLE in the pediatric group (P<0.001). Major complications were more common, albeit not significantly, in children. Complete radiographic and procedural success were significantly lower in children (P<0.001).Conclusions: TLE in children is frequently more complex, time consuming, and arduous, and procedural success is more often lower. This is related to the formation of strong fibrous tissue surrounding the leads in pediatric patients.

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To implement the Mehlich 3 method in Polish agro-chemical laboratories, limit values for deficiency of B, Cu, Fe, Mn and Zn in soil for wheat were developed. The values were developed on the basis of 1921 fields with wheat, evenly distributed throughout Poland. Soil samples were collected from these fields in 2016, together with the plants growing on them, at the stage of stem elongation (BBCH 30/31). The concentration of micronutrients was determined in all soil and plant samples. In addition, pH, texture, and the content of organic carbon and available phosphorus were determined in soil samples. Moreover, grain yield after wheat harvest was estimated for all fields. Limit values were developed by two independent methods: 1) the regression equation method and 2) the so-called high yield method. In the first case, the limit microelement concentration in soil was calculated from the equation describing the relationship between the bioaccumulation factor (R/G) and a specific soil feature (n=1921). The bioaccumulation factor is the quotient of the concentration of a micronutrient in a plant (R) and its concentration in the soil (G) determined by the Mehlich 3 method. The equations were constructed using the Stagraphics program. For each micronutrient, 8 models were tested in search for the equation with the highest determination coefficient r2. Limit values were calculated after substituting the critical value of microelements in the plant (R) to the selected model and transforming the equation accordingly. The basis of the second method was to separate the “high yield group” ≥7.0 t ha−1 (n=578) from the entire data set. In this group, lower quintiles for the Mehlich 3-concentration of individual microelements in soil were calculated. The lower quintiles (QU1) were taken as limit values. It was assumed that QU1 is a good indicator of the lowest micronutrient concentration in the soil at which a yield of 7.0 t ha−1 or higher can be obtained. The comparison of the values calculated with the regression equations method and the high yield method showed their similarity, which confirmed the reliability of these values. The proposed values define the limit for low microelements concentration in soil determined with the Mehlich 3 method, below which wheat fertilization with these nutrients is recommended.

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The optical thickness of highly attenuating packed-bed particulate media can be significantly reduced and, consequently, the radiation heat transfer enhanced, by the addition of large (>100 m) semi-transparent SiO 2 particles. The monochromatic transmittance of packed-bed mixtures of SiO 2 , ZnO, and C particles of various relative mass fractions is experimentally measured as a function of the packed-bed thickness using a He-Ne laser/fiber optic/spectrometer system. Two functions, one derived from the general solution of the equation of radiative transfer for an absorbing-scattering-non emitting medium, and a second one derived from Bouguer's law, were fitted to the experimental data and used to elucidate the effect of the incoming scattering and optical thickness on the medium transmittance. The augmenting contribution of the incoming scattering diminishes with increasing content of highly absorbing carbon particles, and, when it becomes negligible, the extinction coefficient is directly determined by applying Bouguer's law for attenuation of incident radiation along its path.

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A b s t r a c t. One unintended consequence of nitrogen use in agriculture is an increase in nitrate content in ground waters. Nitrogen content was evaluated in soil samples from specific hydrographic regions of Poland from the 60-90 cm soil layer, in which this nutrient is not readily available to the main root mass of crop plants and may negatively affect the environment. It was revealed that N min content in specific hydrographic regions was highly dependent on both the soil type and land use. Notably higher values of N min content were observed for organic soils. The highest N contents were found in the grasslands of the northwestern area of Poland, while they were slightly lower in several regions of the main Odra River catchment and west of the Vistula River. The area with a high N min content in soils under maize was significantly larger compared to the grasslands area and primarily included the hydrographic regions of the Odra River basin in its south-western stretch, and of the Vistula River on its western and south-eastern side. With regard to the arable land under mixed cereals, the soils with the highest N min content in the non-root layer were predominantly located in hydrographic regions belonging to the main Odra catchment and to the catchment of the Vistula River in its upper course.K e y w o r d s: nitrogen, spatial distribution, hydrographic areas, land use, grassland