Detachment of Cu (II) and Co (II) ions from synthetic wastewater via adsorption on Lates niloticus fish bones using LIBS and XRF

Natural fish bones, that are known to have unique adsorption capacity, have been used in the present work for removal of heavy metals, copper, and cobalt, from wastewater. It has been found that sorption process depends on the initial metal concentration and on the contact time. Laser-induced breakdown spectroscopy (LIBS) as a spectrochemical analytical technique was used for qualitative and quantitative analysis of the water samples. X-ray Fluorescence (XRF), as another spectrochemical analytical method, was exploited to characterize the remediation of wastewater. The optimum contact time values for the removal of Cu (II) and Co (II) were 270 and 300 min, respectively. Furthermore, the percentages of adsorbed Cu (II) and Co (II) were high for low initial concentrations and decreased with increasing the heavy metal initial concentrations. The Langmuir and Freundlich isotherm models were used to analyze the equilibrium adsorption data and Freundlich isotherm was found to represent the experimental results well with a correlation factor close to one. However, the pseudo-second-order kinetic model provided the best fit to the experimental data for the adsorption of heavy metals using fish bones compared to the pseudo-first-order model. The obtained results demonstrate the potential of using both LIBS and XRF in the analysis of contaminant wastewater effectively. Keywords: Co and Cu ions, Adsorption, Fishbones, Spectrochemical techniques, Isotherm model

Targeting of somatostatin receptors expressed in blood cells using quantum dots coated with vapreotide

Cancer may be difficult to target, however, if cancer targeted this provides the chance for a better and more effective treatment. Quantum dots (Qdots) coated vapreotide (VAP) as a somatostatin receptors (SSTRs) agonist can be efficient targeting issue since may reduce side effects and increase drug delivery to the target tissue. This study highlights the active targeting of cancer cells by cells imaging with improving the therapeutic outcomes. VAP was conjugated to Qdots using amine-to-sulfhydryl crosslinker. The synthesized Qdots-VAP was characterized by determination of size, measuring the zeta-potential and UV fluorometer. The cellular uptake was studied using different cell lines. Finally, the Qdots-VAP was injected into a rat model. The results showed a size of 479.8 ± 15 and 604.88 ± 17 nm for unmodified Qdots and Qdots-VAP respectively, while the zeta potential of particles went from negative to positive charge which proved the conjugation of VAP to Qdots. The fluorometer recorded a redshift for Qdots-VAP compared with unmodified Qdots. Moreover, cellular uptake exhibited high specific binding with cells which express SSTRs using confocal microscopy and flow cytometry (17.3 MFU comparing to 3.1 MFU of control, P < 0.001). Finally, an in vivo study showed a strong accumulation of Qdots-VAP in the blood cells (70%). In conclusion, Qdots-VAP can play a crucial role in cancer diagnosis and treatment of blood cells diseases when conjugated with VAP as SSTRs agonist. Keywords: Quantum dots, Vapreotide, Somatostatin, Blood, Receptor, Targetin

Iron-Sulfur Cluster Biogenesis in Chloroplasts. Involvement of the Scaffold Protein CpIscA

The chloroplast contains many iron (Fe)-sulfur (S) proteins for the processes of photosynthesis and nitrogen and S assimilation. Although isolated chloroplasts are known to be able to synthesize their own Fe-S clusters, the machinery involved is largely unknown. Recently, a cysteine desulfurase was reported in Arabidopsis (Arabidopsis thaliana; AtCpNifS) that likely provides the S for Fe-S clusters. Here, we describe an additional putative component of the plastid Fe-S cluster assembly machinery in Arabidopsis: CpIscA, which has homology to bacterial IscA and SufA proteins that have a scaffold function during Fe-S cluster formation. CpIscA mRNA was shown to be expressed in all tissues tested, with higher expression level in green, photosynthetic tissues. The plastid localization of CpIscA was confirmed by green fluorescent protein fusions, in vitro import, and immunoblotting experiments. CpIscA was cloned and purified after expression in Escherichia coli. Addition of CpIscA significantly enhanced CpNifS-mediated in vitro reconstitution of the 2Fe-2S cluster in apo-ferredoxin. During incubation with CpNifS in a reconstitution mix, CpIscA was shown to acquire a transient Fe-S cluster. The Fe-S cluster could subsequently be transferred by CpIscA to apo-ferredoxin. We propose that the CpIscA protein serves as a scaffold in chloroplast Fe-S cluster assembly