Nanosilica synthesis mediated by Aspergillus parasiticus strain

Rice husks (RHs) are plant waste materials abundant in phytoliths silica bodies. These were used as starting material for fungal-mediated biotransformation leading to the synthesis of a high-value added product. A strain of Aspergillus parasiticus was capable of transforming the amorphous silica conglomerates into structured nanoparticles (NPs) in the process of RHs biotransformation. Silica NPs were produced extracellularly and their size ranged from 3 to 400 nm depending on the biotransformation conditions and the post-biotransformation supernatant processing. To characterize the NP's structure and dimension, SEM, STEM, EDX and FTIR technics were applied. These demonstrated and confirmed that pyramid (400 nm), cubical (85 nm) and spherical (3 nm and 24 ± 8 nm) forms of silica NPs were obtained.     

Evaluation of Mineral Concentrations in Maternal Serum Before and After Birth and in Newborn Cord Blood Postpartum—Preliminary Study

The mineral levels in maternal serum change during pregnancy and may be correlated with those of newborn cord blood. The aim of this study was to evaluate the concentrations of calcium (Ca), magnesium (Mg), zinc (Zn), iron (Fe), and copper (Cu) in maternal blood before and after delivery and in umbilical cord vein and artery serum. The study was carried out in 64 Caucasian pregnant women who delivered in a district hospital in Greater Poland region, aged 28.1 ± 5.4 years, with a mean gestational age of 39.2 ± 1.3 weeks. Blood samples were taken from women 2–8 h before delivery and immediately after childbirth. The umbilical cord artery and vein blood of newborns was obtained immediately after childbirth. The levels of minerals in serum were determined by flame atomic absorption spectrometry. A significant drop in the concentrations of Mg (17.71 ± 1.51 vs 17.07 ± 1.61 μg/ml; p < 0.007), Fe (1.08 ± 0.46 vs 0.82 ± 0.35 μg/ml; p < 0.0004), and Zn (0.63 ± 0.17 vs 0.46 ± 0.16; p < 0.0001) in maternal serum was found after delivery. Moreover, higher levels of Ca, Fe, and Zn and lower levels of Cu were observed in the umbilical vein (Ca: 102.80 ± 7.80 μg/ml; p < 0.0001, Fe: 1.96 ± 0.43 μg/ml; p < 0.0001, Zn: 0.65 ± 0.16 μg/ml; p < 0.0001, Cu: 0.36 ± 0.09 μg/ml; p < 0.0001) and in the umbilical artery cord blood (Ca: 98.07 ± 8.18 μg/ml; p < 0.0001, Fe: 1.63 ± 0.30 μg/ml; p < 0.0001, Zn: 0.65 ± 0.15 μg/ml; p < 0.0001, and Cu: 0.36 ± 0.10 μg/ml; p < 0.0001) compared to the maternal serum (Ca: 85.05 ± 10.76 μg/ml, Fe: 0.82 ± 0.35 μg/ml, Zn: 0.46 ± 0.16 μg/ml, and Cu: 1.90 ± 0.35 μg/ml). Fe levels in the cord artery serum negatively correlated with blood loss during delivery (R = ?0.48; p = 0.01), while the Ca concentration in the maternal serum after birth decreased with the age of the women (R = ?0.25; p = 0.03). In conclusion, it seems that the process of birth alters the mineral levels in pregnant women’s blood. Moreover, it was found that blood loss and the age of the mother are associated with mineral concentrations in the maternal serum and cord artery blood.     

4-N-Alkanoyl and 4-N-alkyl gemcitabine analogues with NOTA chelators for 68-gallium labelling

The conjugation of 4-N-(3-aminopropanyl)-2′-deoxy-2′,2′-difluorocytidine with 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (SCN-Bn-NOTA) ligand in 0.1?M Na₂CO₃ buffer (pH 11) at ambient temperature provided 4-N-alkylgemcitabine-NOTA chelator. Incubation of latter with excess of gallium(III) chloride (GaCl₃) (0.6?N AcONa/H₂O, pH?=?9.3) over 15?min gave gallium 4-N-alkylgemcitabine-NOTA complex which was characterized by HRMS. Analogous [⁶⁸Ga]-complexation of 4-N-alkylgemcitabine-NOTA conjugate proceeded with high labeling efficiency (94%–96%) with the radioligand almost exclusively found in the aqueous layer (～95%). The high polarity of the gallium 4-N-alkylgemctiabine-NOTA complex resulted in rapid renal clearance of the ⁶⁸Ga-labelled radioligand in BALB/c mice.     

Diurnal cycle of carbon isotope ratio in soil CO2 in various ecosystems

Our investigations of diurnal variations of the ¹³C/¹²C ratio and CO₂ content in soil air were carried out in three environments during periods of high biosphere activity. It has been observed that diurnal variation of CO₂ concentration is negatively correlated ¹³. Particularly great variations occurred at shallow soil depths (10–30 cm) when the plant cover activity was high while the soil temperature was rather low. Under such conditions the ¹³ variations had the magnitude of 4, while the CO₂ concentration varied more than doubly. The maximum of the ¹³C/¹²C ratlo and the minimum of the CO₂ concentration in a cultivated field with winter wheat took place in the afternoon, whereas in deciduous forest similar patterns were observed at dawn. In these cases soil temperatures at 10 cm depths varied less than 2°C. Hence, under wheat the variation in root respiration rate seem to be the main reason of the recorded varations. In an uncultivated grass-field during the hottest period in summer we did not measure any distinct variations of CO₂ properties in spite of the fact that soil temperature varied up to 5°C. This might be due to dominant microbial respiration at the high soil temperature, which exceeded 20°C.     

Differences in drought tolerance between cultivars of field bean and field pea. Morphological characteristics, germination and seedling growth

Different responses among legume species were observed, but the morphological and physiological differences that confer drought resistance or susceptibility are not well explained. The objective of this study was the determination of variation of morphological characteristics within 7 field bean and 4 field pea cultivars as related to drought tolerance. Also differences in the effect of drought on seed germination and seedling growth in 2 field bean and 2 field pea cultivars of different drought tolerances were investigated. The examined cultivars were characterized by variation of certain morphological characteristics regarded as xeromorphic features associated with the ability of plant to survive under drought. The drought resistant cultivars (field bean Gobo and field pea Solara) in comparison with the sensitive ones (field bean Victor and field pea Bareness) were characterized by more favourable relations between the size of the above—ground parts and the size of root, as well as the frequency and size of stomata. Moreover, in the resistant cultivars there was observed, a smaller influence of simulated drought (ψ=−0.6 MPa) on the increase of dry matter of the above-ground parts and of the roots. Also there was smaller influence on the height of seedlings and on the length of lateral roots. The correlation coefficients between the measured characteristics and the values of the drought susceptibility index (DSI) were in most cases statistically not significant, although, on the whole, they were very high. This may be an indication of a relatively high participation of the measured characteristics in the total variation of the drought tolerance in the cultivars. In cultivars regarded as belonging to the group of sensitive ones, a more disadvantageous effect of simulated drought (ψ=−0.6 MPa) on seed germination was observed, especially in the determination of the promptness index (PI).     

Differences in drought tolerance between cultivars of field bean and field pea. A comparison of drought-resistant and drought-sensitive cultivars

Relatively little research has been conducted to determine different responses to drought among cultivars of the legume species. The objective of this study was to identify differences in seedlings growth, water relations and leaf conductances resulting from drought imposed on two field bean and two field pea cultivars that had been observed to differ in their drought tolerances, and special emphasis was placed on the root system development. Distinct differences between resistant and sensitive cultivars of field bean and field pea became evident in measurements of the characteristics of the lateral root. The drought treatment induced statistically significant decrease in the number of the developed laterals, their total length and dry matter. In the drought resistant cultivars (field bean Gobo and field pea Solara) this reduction was smaller in comparison with sensitive ones (field bean Victor and field pea Bareness). The effect of drought on growth of tap root in the drought resistant and drought sensitive cultivars was smaller and statistically not significant. The results showed that drought resistant cultivars when compared with drought sensitive one would demonstrate less abundance in the above-ground part and greater dimensions of the root system. The measurements of leaf water potential and stomata diffusive resistance measurements indicate that the physiological reasons for the different reactions to drought between the resistant and the sensitive field bean and field pea cultivars may be due to a more effective protection of the level of tissue hydration and due to increase stomata diffusive resistance in the resistant cultivars. During recovery period it has been also demonstrated that in the drought resistant cultivars a tendency exists for a more complete return to the level of the control plants.     

Pseudoguaianolides from Gaillardia grandiflora

The aerial parts of Gaillardia grandiflora afforded two new pseudoguaianolides,9-O-desacetylspathulin-2-O-angelate 9-O-desacetylspathulin-2-O-isovalerate. The structures were elucidated by ¹H NMR spectroscopic investigations by some chemical transformations.     

Characteristic features of the coumarin induced growth

Summary Effect of 2,4-dinitrophenol, iodoacetic acid, mannitol, ribonuclease, CaCl₂, phosphates, low oxygen tension, different temperatures, CCC and IAA on the coumarin-induced growth of sunflower hypocotyl sections have been investigated. Results indicate that coumarin-induced growth is auxin-like in type; nevertheless, the primary mode of coumarin action is probably quite different from that of IAA.With 4 Figures in the Text