Growth characteristics, nitrogen uptake and enzyme activities of the nitrate-utilising ectomycorrhizal Scleroderma verrucosum

The growth characteristics and uptake capacities for NO3- and NH4+, as well as activities of nitrogen assimilating-enzymes have been determined in Scleroderma verrucosum. Biomass, grown on agar or liquid MMN media, was higher on nitrate. When S. verrucosum was grown in the presence of equal amounts of ammonium and nitrate, uptake rate for NH4+ was considerably higher than that of NO3-. In addition, it was found that a limitation in ammonium concentration was a prerequisite for nitrate uptake. Nitrate reductase was stimulated when the fungus was transferred from ammonium to nitrate containing media, indicating that the enzyme was inducible by nitrate and repressed by ammonium. Glutamine synthetase and NAD-glutamate synthase activities were clearly detected in S. verrucosum, while the NADP-glutamate dehydrogenase was almost undetectable. This is consistent with the view that ammonium assimilation occurs through the GS/GOGAT cycle in S. verrucosum

Investigation of CuIn1-xGaxSe2 thin films co-evaporated from two metal sources for photovoltaic solar cells

 CuIn1-xGaxSe2 (CIGS) thin films were grown by co-evaporation using two sources for the metal elements (Cu, Ga and In). A Mo coated soda lime glass substrates heated at 500 °C was used for the deposition. X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirm that these films are polycrystalline with a chalcopyrite structure and showed homogeneous grain size estimate about 25 nm. X-ray photoelectron spectroscopy (XPS) was performed to analyse the binding energy values of Ga3d and O1s onto CIGSe layers. The conductivity measurements in the temperature range of 40-400 K were carried out for 0.05≤ x ≤ 0.23. The effect of grain boundary scattering on the electrical transport played an important role in describing the transport processes in these films. The bowing factor is discussed taking into account the deposition techniques of CIGS films. It has been noticed that the open circuit voltage (Voc) is influenced by Ga content and the energy gap value of the absorber CIGS thin layers and yielded a poor efficiency of solar cells

Modelowanie obecnego i przyszłego zaopatrzenia i zapotrzebowania na wodę w północnym regionie Doliny Seybouse

Water in the Seybouse River basin is getting scarce, yet it is the key to its economic development. A fast growing population, expanding agricultural and industrial sectors and the impacts of climate variability, create demands for new water sources and innovative management of water resources and services. The object of this study is the water resources management in the lower Seybouse basin characterized by a steady increase of water demand to meet different uses. This study takes into account changes in water demand of different urban, agricultural and industrial supply process. Our approach is to integrate data in WEAP modelling software to simulate current and future water balance and then to analyse the situation of water in different scenarios, socio-economic development and climate change to 2050. This software is based on the representation of the feeding system in a form of the network of water demand and supply. Our findings reveal the vulnerability of the region in its ability to the pressures resulting from the increase of needs of different sectors at the horizon of the forecasted period. They also indicate the need for larger mobilization of new resources into the system and lay the foundations for a sustainable water policy in the northern region of the Seybouse valley.Zasoby wody w zlewni rzeki Seybouse są coraz skromniejsze, a przecież są one kluczowym elementem rozwoju gospodarczego. Szybko rosnąca liczba ludności, rozwój rolnictwa i przemysłu oraz wpływ zmienności klimatu tworzą zapotrzebowanie na nowe źródła wody i innowacyjne metody zarządzania jej zasobami. Przedmiotem badań było zarządzanie zasobami w dolnej części zlewni Seybouse. W badaniach uwzględnia się zmiany zapotrzebowania na wodę w miastach, rolnictwie i przemyśle. W pracy integrowano dane w programie WEAP w celu symulowania obecnego i przyszłego bilansu wodnego, a następnie analizowano sytuację w warunkach różnych scenariuszy społeczno-gospodarczego rozwoju i zmian klimatycznych do roku 2050. Program polega na przedstawieniu systemu zasilania w formie sieci potrzeb i zaopatrzenia w wodę. Wyniki badań ujawniły wrażliwość regionu na presje wynikające z rosnących potrzeb wodnych różnych sektorów w prognozowanym horyzoncie czasowym. Wskazały także potrzebę uruchomienia nowych zasobów w systemie i stworzenia podstaw zrównoważonej polityki wodnej w północnym regionie doliny Seybouse

A new family of 1,2,5-thiadiazolidine 1,1-dioxides: Synthesis, structure and antibacterial activity

International audienceA convenient synthesis of novel N-N’-substituted 1,2,5-thiadiazolidine 1,1-dioxides starting from amino acids isreported in five step (reduction, carbamoylation-sulfamoylation, intermolecular cyclization via the Mitsunobureaction and acylation). The newly synthesized compounds were characterized by IR, NMR and mass spectralanalysis. Some of the newly synthesized compounds (4c and 4d) were examined for their antibacterial activityagainst several strains of Gram-positive and Gram-negative bacteria

Optimisation of the interface “organic material/aluminium” of CuPc/C

We report the influence of an exciton-blocking layer and/or an Al2O3 thin layer at the interface “organic acceptor/aluminium” on the efficiency of CuPc/C60 based photovoltaic cells. The presence, or not, of a thin Al2O3 layer depends on the encapsulating process of the devices. In the case of glass/ITO/CuPc/C60/Al cells, the presence of an Al2O3 thin layer at the interface “organic acceptor/aluminium” increases strongly the open circuit voltage of the cells but decreases slightly their short circuit current and fill factor. In the case of glass/ITO/CuPc/C60/Alq3/Al cells, the open circuit voltage is systematically higher than without Alq3. However, in that case, the presence of Al2O3 does not improve significantly the cell performances. All these results are discussed in terms of series and shunt resistance values related to possible oxygen contamination and organic covalent action with the Al films. The effectiveness of these different phenomena depends on the presence, or not, of Alq3 and/or Al2O3 layers

On the improvement of the efficiency of organic photovoltaic cells by the presence of an ultra-thin metal layer at the interface organic/ITO

Organic photovoltaic cells based on the multilayers structure, indium tin oxide (ITO)/copper-phthalocyanine(CuPc)/fullerene(C60)/aluminium tris(8-hydroxyquinoline) (Alq3)/aluminium, have been studied. When an ultra-thin metal layer is deposited onto the surface of the ITO anode the power conversion efficiency of the cells is significantly improved. The improvement depends on the ITO used. These differences have been attributed to the difficulty to control the surface chemistry of ITO. The best result has been obtained with a gold layer thick of about 0.5 nm. We propose that the gold ultra-thin film, which is too thin to be continuous, allows to improve the agreement between the work function of the anode and the highest occupied molecular orbital (HOMO) of the organic donor CuPc and to passivate the surface contamination of ITO

Morphological, molecular, and biochemical study of cyanobacteria from a eutrophic Algerian reservoir (Cheffia)

The cyanobacteria management in water bodies requires a deep knowledge of the community composition. Considering the reliable and thorough information provided by the polyphasic approach in cyanobacteria taxonomy, here we assess the cyanobacterial community structure of the Cheffia reservoir from Algeria. Cyanobacteria were identified on the basis of morphological traits and next-generation sequencing (NGS); toxins-related genes were localized in addition to the identification of toxins; temperature and nutrient level of water samples were also determined. The polyphasic approach was essential for cyanobacteria investigation; 28 genera were identified through 16S rRNA metabarcoding with the dominance of taxa from Microcystis (34.2%), Aphanizomenon (20.1%), and Planktothrix (20.0%), and morphological analysis revealed the association in this water body of five species within the genus Microcystis: M. aeruginosa, M. novacekii, M. panniformis, M. ichthyoblabe, and M. flos-aquae. The presence of mcyE genotypes was detected; moreover, HPLC–PDA and LC–ESI–MS/MS revealed the production of microcystin-LR. Results obtained in our study are very important since this ecosystem is used for water supply and irrigation; as a consequence, a good water management plan is essential

Synthesis and Evaluation of Some New 4<i>H</i>-Pyran Derivatives as Antioxidant, Antibacterial and Anti-HCT-116 Cells of CRC, with Molecular Docking, Antiproliferative, Apoptotic and ADME Investigations

Colorectal cancer oncogenesis is linked to dysbiosis, oxidative stress and overexpression of CDK2. The 4H-pyran scaffold is considered an antitumoral, antibacterial and antioxidant lead as well as a CDK2 inhibitor. Herein, certain 4H-pyran derivatives were evaluated as antibacterial, antioxidant and cytotoxic agents against HCT-116 cells. Derivatives 4g and 4j inhibited all the tested Gram-positive isolates, except for B. cereus (ATCC 14579), with lower IC50 values (µM) than ampicillin. In addition, 4g and 4j demonstrated the strongest DPPH scavenging and reducing potencies, with 4j being more efficient than BHT. In cell viability assays, 4d and 4k suppressed the proliferation of HCT-116 cells, with the lowest IC50 values being 75.1 and 85.88 µM, respectively. The results of molecular docking simulations of 4d and 4k, inhibitory kinase assays against CDK2, along with determination of CDK2 protein concentration and the expression level of CDK2 gene in the lysates of HCT-116 treated cells, suggested that these analogues blocked the proliferation of HCT-116 cells by inhibiting kinase activity and downregulating expression levels of CDK2 protein and gene. Moreover, 4d and 4k were found to induce apoptosis in HCT-116 cells via activation of the caspase-3 gene. Lastly, compounds 4g, 4j, 4d and 4k were predicted to comply with Lipinski’s rule of five, and they are expected to possess excellent physiochemical and pharmacokinetic properties suitable for in vivo bioavailability, as predicted by the SwissADME web tool