An accurate comparative theoretical study of the interaction of furan,pyrrole, and thiophene with various gaseous analytes

An accurate comparison of the interaction of furan, pyrrole, and thiophene with different gaseous analytes is vital not only for understanding the sensing mechanism of corresponding polymers but also for rational design of new materials. In the present study, DFT calculations at (M05-2X/Aug-cc-PVDZ) have been performed to investigate the interaction behavior of furan, pyrrole, and thiophene (as models for their corresponding polymers) with different analytes (NH₃, CO₂, CO, N₂H₄, HCN, H₂O₂, H₂S, CH₄, CH₃OH, SO₂, SO₃, H₂O). The interaction of heterocycles with analytes is illustrated by changes in geometric, energetic, and electronic properties. SAPT calculations were performed for energy decomposition analysis to study the contribution of non-covalent components of the total interaction energy for each complex. Analysis of energetic and electronic properties reveals that all heterocycles are highly sensitive to SO₃. The results suggest that sensing ability of polypyrrole is higher than polyfuran and polythiophene for all analytes.

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Graphical abstract SAPT0 energies (kcal mol^-1) of furan, pyrrole, and thiophene with various gaseous analytes?

     

Bacterial microbiomes of individual ectomycorrhizal Pinus sylvestris roots are shaped by soil horizon and differentially sensitive to nitrogen addition

Plant roots select non‐random communities of fungi and bacteria from the surrounding soil that have effects on their health and growth, but we know little about the factors influencing their composition. We profiled bacterial microbiomes associated with individual ectomycorrhizal Pinus sylvestris roots colonized by different fungi and analyzed differences in microbiome structure related to soils from distinct podzol horizons and effects of short‐term additions of N, a growth‐limiting nutrient commonly applied as a fertilizer, but known to influence patterns of carbon allocation to roots. Ectomycorrhizal roots growing in soil from different horizons harboured distinct bacterial communities. The fungi colonizing individual roots had a strong effect on the associated bacterial communities. Even closely related species within the same ectomycorrhizal genus had distinct bacterial microbiomes in unfertilized soil, but fertilization removed this specificity. Effects of N were rapid and context dependent, being influenced by both soil type and the particular ectomycorrhizal fungi involved. Fungal community composition changed in soil from all horizons, but bacteria only responded strongly to N in soil from the B horizon where community structure was different and bacterial diversity was significantly reduced, possibly reflecting changed carbon allocation patterns.     

A novel homozygous frameshift variant in the <Emphasis Type="Italic">MCPH1 gene causes</Emphasis> primary microcephaly in a consanguineous Saudi family

Primary microcephaly (MCPH) is a rare developmental defect characterized by impaired cognitive functions, retarded neurodevelopment and reduced brain size. It is genetically heterogeneous and so far more than 17 genes associated with this disease have been identified. Primary microcephaly type 1 (MCPH1) gene encodes a protein called microcephalin, which is implicated in chromosome condensation and DNA damage induced cellular responses. It is suggested to play a role in neurogenesis and regulation of the size of the cerebral cortex. Whole exome sequencing revealed a novel, homozygous frameshift mutation (c.373_374delAA) in MCPH1 gene in exon 5 resulting in frameshift change from p.Lys125Glusfs*7. Our report presents the results of the simultaneous analysis of the trio exome data of both unaffected parents and their affected son. A homozygous frameshift variant in the MCPH1 gene was identified as a plausible candidate causal variant for the clinical phenotype in this family.     

New chromosome counts in nine endemic species from Iran

Original meiotic chromosome counts are presented for nine endemic species in seven families of Angiosperms from Iran including:Arum giganteum Ghahr. (Araceae) (n=14),Caccinia actinobole Bunge (Boraginaceae) (n=8),Delphinium aquilegifolium (Boiss.)Bornm. (Ranunculaceae) (n=8),Diplotaenia damavandica Mozaff., Hedge etLamond (Apiaceae) (n=11),Gypsophila caricifolia Boiss. (Caryophyllaceae) (n=17),Iphiona arachnoidea (Boiss.)Anderb. (Asteraceae) (n=9),Moltkia gypsacea Rech. f. etAellen (Boraginaceae) (n=20),Onobrychis gaubae Bornm. (Fabaceae) (n=8) andOnosma platyphyllum Riedl (Boraginaceae) (n=9). Eight counts are reported for the first time. Furthermore, the previous chromosome count forIphiona aracnoidea is corrected. Based on cytological data the species status ofMoltkia gypsacea is confirmed; it is not merely synonymous withM. coerulea (Willd.)Lehm. The basic chromosome number n=11 is reported in the genusDiplotaenia for the first time.     

Expression of sodium-glucose co-transporter and brush border disaccharidases in Giardia lamblia infected rat intestine

The absorption of D-glucose and brush border membrane disaccharidases in the intestine of rat during infection by Giardia lamblia has been studied. The level of mRNA encoding Na+/glucose co-transporter (SGLT1) and brush border sucrase and lactase activities were also analyzed. At the peak of infection, i.e, day 7, 11 and 15 post-infection, there was a marked decrease in the signal of 4.5 kb and 2.8 kb mRNAs encoding SGTL1 compared to the controls. A similar decrease in sucrase and lactase mRNA's (6.5 kb and 6.8 kb respectively) was also observed under these conditions. This corresponds to observed decrease in the rate of Na(+)-dependent D-glucose uptake and low activities of brush border sucrase and lactase under these conditions. There was no change in Na(+)-independent D-glucose uptake in giardia infected rat intestine. These findings suggest that the down regulation of the expression of SGLT1 and brush border sucrase and lactase activities may be responsible for the observed malabsorption in G. lamblia infection.     

Carotenoid uptake and secretion by CaCo-2 cells: beta-carotene isomer selectivity and carotenoid interactions

In presence of oleate and taurocholate, differentiated CaCo-2 cell monolayers on membranes were able to assemble and secrete chylomicrons. Under these conditions, both cellular uptake and secretion into chylomicrons of beta-carotene (beta-C) were curvilinear, time-dependent (2-16 h), saturable, and concentration-dependent (apparent K(m) of 7-10 microM) processes. Under linear concentration conditions at 16 h incubation, the extent of absorption of all-trans beta-C was 11% (80% in chylomicrons), while those of 9-cis- and 13-cis-beta-C were significantly lower (2-3%). The preferential uptake of the all-trans isomer was also shown in hepatic stellate HSC-T6 cells and in a cell-free system from rat liver (microsomes), but not in endothelial EAHY cells or U937 monocyte-macrophages. Moreover, extents of absorption of alpha-carotene (alpha-C), lutein (LUT), and lycopene (LYC) in CaCo-2 cells were 10%, 7%, and 2.5%, respectively. Marked carotenoid interactions were observed between LYC/beta-C and beta-C/alpha-C. The present results indicate that beta-C conformation plays a major role in its intestinal absorption and that cis isomer discrimination is at the levels of cellular uptake and incorporation into chylomicrons. Moreover, the kinetics of cellular uptake and secretion of beta-C, the inhibition of the intestinal absorption of one carotenoid by another, and the cellular specificity of isomer discrimination all suggest that carotenoid uptake by intestinal cells is a facilitated process.     

Dominant-negative NSF2 disrupts the structure and function of Drosophila neuromuscular synapses

N-ethylmaleimide sensitive fusion protein (NSF) is an ATPase necessary for vesicle trafficking, including exocytosis. Current models hold that NSF is required in a step that readies vesicles for fusion by disassembling postfusion SNARE protein complexes allowing them to participate in further rounds of vesicle cycling. Whereas most organisms have only one NSF isoform, Drosophila has two. dNSF1 is the predominant functional isoform in the adult nervous system. Conditional mutations in the dNSF1 gene, comatose, are paralytic and lead to disruption of synaptic transmission and the rapid accumulation of SNARE complexes in adult flies. This isoform is not required for synaptic transmission in larvae. In contrast, dNSF2 is important at earlier developmental stages, and its broad expression indicates its importance in neural and non-neural tissues alike. To study dNSF2, and to circumvent the lethality of dNSF2 null mutants, we have constructed transgenic flies carrying a dominant negative form of dNSF2. When this construct was expressed in neurons we observed suppression of synaptic transmission, activity-dependent fatigue of transmitter release, and a reduction in the number of releasable vesicles. However, we unexpectedly found that there was no accumulation of SNARE complexes accompanying these physiological phenotypes. Intriguingly, we also found that expression of mutant dNSF2 induced pronounced overgrowth of the neuromuscular junction and some misrouting of axons. These results support the idea that dNSF2 has multiple roles in cellular function and adds that not all of its functions require disassembly of the SNARE complex.