23 research outputs found
Treatment of Chromium(III) in Tannery Wastewater Using LDH Incorporated With EDTA
Removing of Chromium(III) from contaminated tannery wastewater by adsorption on Zn/Al layered double hydroxides incorporated with ethylenediamintetraacetic acid, referred to as Zn/Al-EDTA, has been investigated by batch experiments. The effects of different parameters on the percentage relative adsorption concentration were carried out. The adsorption capacity with the Zn/Al-EDTA, provided almost complete removal of chromium(III) which was accomplished within one hour, while the Zn/Al-EDTA particles were kept in suspension by shaking. The effect of pH on sorption in the range of 2-8 at an optimized temperature of 300C was studied having 95% removal efficiency. The kinetics of adsorption were evaluted and conformed well with the Langmuir isotherm The bound Cr(III) ions could be eluted successfully using 0.1?M HCl. The sorption–desorption studies employing that the Zn/Al-EDTA could be regenerated without any major loss in the adsorption capacity. The Zn,Al layered double hydroxides (LDHs) host was intercalated by an anionic ethylenediaminetetraacetate (EDTA) guest. It was prepared by coprecipitation of the EDTA anion with the precursor Zn,Al-NO3 LDHs in a basic condition. Characterization of Zn/Al-EDTA was done using Powder X-ray diffraction (PXRD), elemental analysis and FTIR spectroscopy indicated that most of the interlayer nitrate anions were displaced by (EDTA) anions to form Zn/Al-EDTA which then used as sorption material for Cr(III) metal ion from tanning wastewater. Keywords: tannery wastewater, layered double hydroxides, sorption, chromium(III), edta
A New Approach for Preparing Methyl 6-azido-2,3,4-tri-O-benzyl-6-deoxy-alpha-D-glucopyranoside
Azide sugars are key intermediates in the synthesis of aminglycosides, which themselves are useful for the synthesis of glycopeptides. A new method has been achieved by using DPPA and DBU in dry DMF with high temperature for replacement of the azide group from alcohol (glucoside) on the position 6. The results of this method are very important for preparing 6-azido sugar without needing to prepare and separate glucosyl halide completely. The proposed method was successfully applied with direct, simple, and time saving. In addition, excellent yield of 95% was obtained from azide, which could be used to obtain pharmaceutical active compounds. Keywords: Methyl 6-azido-2,3,4-tri-O-benzyl-6-deoxy-?-D-glucopyranoside, DPPA, DBU, azides
Молекуларна карактеризација и филогенетски односи европских врста рода Aphidius Nees (Hymenoptera, Braconidae, Aphidiinae)
The genus Aphidius includes many species of economic importance that are used as biocontrol agents against numerous pest aphids in greenhouses and under open field conditions. However, classification within this genus is constantly revisited, in view of the fact that the biology, ecology and taxonomic status of many species are still understudied. Partial sequences of the cytochrome oxidase subunit I mitochondrial gene (mtCOI) and Elongation factor 1-α nuclear gene (EF1-α) were used to explore the taxonomic status and phylogenetic relationships of 33 European species from the genus Aphidius in different aphid /plant host associations over a wide area of distribution. Phylogenetic analyses clarified that Aphidius is in fact a paraphyletic group. Topology of the maximum likelihood tree showed separation of 22 taxa as independent species: A. erysimi, A. sonchi, A. linosiphonis, A. hieraciorum, A. arvensis, A. balcanicus, A. phalangomyzi, A. banksae, A. uzbekistanicus, A. sussi, A. silvaticus, A. avenae, A. rosae, A. ericaphidis, A. eadyi, A. viaticus, A. schimitscheki, A. ribis, A. setiger, A. asteris, A. matricariae and A. urticae. Besides “good” species, five more clades were distinguished: i) A. salicis and A. aquilus; ii) A. funebris, A. tanacetarius, A. absinthii; iii) A. ervi and A. microlophii; iv) A. chaetosiphonis and A. hortensis; v) A. rubi and A. rhopalosiphi. Taxa within five clades could not be clearly discriminated as separate species based on either mtCOI or EF1-α. Failure of the two markers to delimit these taxa could be attributed either to adaptive divergence due to host and/or habitat range expansion and speciation or to mitochondrial introgression via hybridization of sibling species. In any event, it is suggested that their taxonomic status be re-visited using an integrative approach. Molecular characterization revealed cryptic taxa associated with different hosts within the A. urticae group. Re-descriptions of A. urticae s. str., A. rubi and A. silvaticus are given. Also, mtDNA barcoding identified the presence of A. ericaphidis for the first time in EuropeУ род Aphidius класификоване су многе врсте које су економски значајне као биолошки агенти за контролу штетних врста биљних вашију у стакленицима и на отвореном пољу. Обзиром да биологија, екологија и таксономски статус многих врста нису довољно истражени, класификација врста унутар рода се континуирано ревидира. Делимичне секвенце гена митохондријске ДНК цитохром оксидазе субјединица I (mtCOI) и једарног гена за фактор елонгације 1-α a (EF1-α) су маркери коришћени у истраживању таксономског статуса и филогенетиских односа 33 врсте рода Aphidius у асоцијацији са раличитим врстама ваши и биљака домаћина сакупљених са ширег арела у Европи. Филогенетске анализе су потврдиле да је род Aphidius парафилетички. На филогенетском стаблу конструисаном maximum likelihood методом јасно је издвајање следећа 22 таксона као засебних врста: A. erysimi, A. sonchi, A. linosiphonis, A. hieraciorum, A. arvensis, A. balcanicus, A. phalangomyzi, A. banksae, A. uzbekistanicus, A. sussi, A. silvaticus, A. avenae, A. rosae, A. ericaphidis, A. eadyi, A. viaticus, A. schimitscheki, A. ribis, A. setiger, A. asteris, A. matricariae и A. urticae Поред ових „добрих“ врста, издовјило се још пет клада: i) A. salicis и A. aquilus; ii) A. funebris, A. tanacetarius, A. absinthii; iii) A. ervi и A. microlophii; iv) A. chaetosiphonis и A. hortensis; v) A. rubi и A. rhopalosiphi. Врсте у овим кладама се не могу јасно идентификовати на основу митохондријског и једарног маркера. Неуспех у идентификацији врста применом ових маркера може се приписати адаптивној дивергенцији услед ширења круга домаћина или станишта и специјацији, или митохондријалној интрогресији приликом хибридизације примерака сродних врста. За поједине врсте сугерише се ревизија таксономског статуса, примењујући савремени интегративни приступ. Молекуларна идентификација mtCOI открила је у оквиру комплекса врста A. urticae три криптичне врсте A. urticae s. str., A. rubi и A. silvaticus. Такође, ДНК баркодинг метод је потврдио први пут у Европи присуство врсте A. ericaphidis
Suzuki-Miyaura Cross-Coupling Reaction Based on Novel Palladium(II) Diphenylphosphine Derivative Catalyst
The synthesis and characterization of palladium complexes ((CH3)3SiC6H4PPh2)2PdCl2,4a, and ((CH3)3SiC12H8PPh2)2PdCl2, 4b, containing phosphine (CH3)3SiC6H4PPh2, 3a and (CH3)3SiC12H8PPh2, 3b ligands are reported. The phosphine ligands are prepared conveniently in high yield by treatment of the corresponding 1,4-dibromoarene with one equivalent of butyl lithium, and one equivalent of ClPPh2 at -78 °C under an atmosphere of argon. The palladium complexes are synthesized by the reaction of Pd(cod)Cl2 with two equivalent of the above mentioned phosphine ligands. The new complexes were fully characterized by spectroscopic methods and elemental analysis. Furthermore, the use of the palladium (II) complexes of such system as pre-catalysts for the Suzuki-Miyaura coupling of some arylbromides and arylchloride with substituted phenyl boronic acid has been tested. Keywords:1,4-dibromoarene, Palladium complex, Suzuki coupling, catalyst
Quality of t-cell response to SARS-CoV-2 mrrna vaccine in art-treated plwh
We investigated specific humoral and T-cell responses in people living with HIV (PLWH) before (T0), after two (T1) and after six months (T2) from the third dose of the BNT162b2 vaccine. Healthy donors (HD) were enrolled. The specific humoral response was present in most PLWH already after the second dose, but the third dose increased both the rate of response and its magnitude. Collectively, no significant differences were found in the percentage of responding T-cells between PLWH and HD. At T0, stratifying PLWH according to CD4 cell count, a lower percentage of responding T-cells in 200 cells/mu L one was observed. At T1, this parameter was comparable between the two subgroups, and the same result was found at T2. However, the pattern of co-expression of IFN gamma, IL2 and TNF alpha in PLWH was characterized by a higher expression of TNF alpha, independently of CD4 cell count, indicating a persistent immunological signature despite successful ART. mRNA vaccination elicited a specific response in most PLWH, although the cellular one seems qualitatively inferior compared to HD. Therefore, an understanding of the T-cell quality dynamic is needed to determine the best vaccination strategy and, in general, the capability of immune response in ART-treated PLWH
Layered hydroxide anion exchanger and their applications related to pesticides: a brief review
Layered double hydroxides and layered hydroxide salts have generated enormous excitement in the inorganic field due to their potential to act as versatile host materials in fabricating novel host–guest layered materials. The ability of the layered hydroxide anion exchanger to be incorporated with a wide range of guest ions enable them to be exploited in various applications related to pesticides. This review sums up the different methods of preparing layered hydroxide anion exchanger, summarises the types of anion intercalated into these layered hydroxide anion exchanger based on their respective systems, and elucidates their potential applications in pesticide-related fields