Effective Removal of Cr(VI) from Wastewater Using Biochar Derived from Walnut Shell.

Heavy metals are the major concern of the modern age. Among the heavy metals, chromium (Cr(VI)) is regarded as a highly toxic heavy metal released largely from leather tanning operations. To remove such high concentrations of Cr(VI), an advanced method is required urgently. Thus, biosorption using biochar, which is an organic material produced from various sources such as walnut shell, can be applied successfully for Cr(VI) abatement. The major objectives of this experiment were the remediation of the Cr(VI) heavy metal using walnut shell biochar and checking of the effect of pH, biochar dosage, Cr level, and shaking time. Remediation of Cr(VI) using walnut shell biochar was proved to be effective and removed the maximum concentration of Cr(VI) up to 93% at pH 5.5, 2 h agitation time, and the biochar amount of 1.1 g L-1 from an aqueous solution. Equilibrium modeling demonstrated that the chemisorption process was involved in adsorption of Cr(VI). The surface of the biochar was porous and provided numerous sites for Cr(VI) attachment, which was also confirmed by the presence of Cr(VI) onto the biochar after adsorption. Hence, the use of walnut shell biochar was highly effective as a sorbent, which could conveniently be applied to small-scale as well as large-scale levels.

Identification of Genetic Variants Associated With Myocardial Infarction in Saudi Arabia.

The genetic variants associated with various genetic disorders have not been identified decisively in Saudi Arabia. Among these variants, six known for their association with coronary artery disease or myocardial infarction (MI) were studied on Saudi patients. Reference single nucleotide polymorphisms (SNPs) of these variants are rs5174, rs11591147, rs2259816, rs111245230, rs3782886 and rs2259820, referring to genes LRP8, PCSK9, HNF1A, SVEP1, BRAP and HNF1A, respectively. The analysis employed polymerase chain reaction panel coupled with mini-sequencing (SNapShot multiplex system) in order to identify these variants. A total of 100 MI patients and 103 healthy control individuals participated in this study. The six variants (SNPs) were evaluated for the risk of developing MI in the Saudi patients. Analysis of allele frequencies indicated that A allele of rs11591147 variant can be a protective allele, thus, is associated with the decreased risk of MI in Saudi individuals. Rare allele of rs111245230 variant (e.g., C allele) was extremely reduced, while rare allele of rs3782886 variant (e.g., G allele) does not exist in the ethnic signature of the Saudi population. This study elucidates the possible prediction of risk factors associated with severe diseases in Saudi population utilizing SNapShot multiplex system.

Stepwise response of MeJA-induced genes and pathways in leaves of C. roseus.

Catharanthus roseus is a perennial herb known for the production of important terpenoid indole alkaloids (TIAs) in addition to a variety of phenolic compounds. The goal of the present work was to detect the prolonged effects of MeJA (6 uM) treatment across time (up to 24 days) in order to detect the stepwise response of MeJA-induced genes and pathways in leaves of C. rouses. Prolonged exposure of plants to MeJA (6 uM) treatment for different time points (6, 12 and 24 days) indicated that genes in the indole alkaloid biosynthesis pathway and upstream pathways were triggered earlier (e.g., 6 days) than those in the anthocyanin biosynthesis pathway and its upstream pathways (e.g., 12 days). Three enzymes, e.g., T16H, OMT, and D4H, in the six-step vindoline biosynthesis and two enzymes, e.g., TDC and STR, acting consecutively in the conversion of tryptophan to strictosidine, were activated after 6 days of MeJA treatment. Two other key enzymes, e.g., TRP and CYP72A1, acting concurrently upstream of the TIA biosynthesis pathway were upregulated after 6 days. The genes encoding TDC and STR might concurrently act as a master switch of the TIA pathway towards the production of the indole alkaloids. On the other hand, we speculate that the gene encoding PAL enzyme also acts as the master switch of phenylpropanoid biosynthesis and the downstream flavonoid biosynthesis and anthocyanin biosynthesis pathways towards the production of several phenolic compounds. PAL and the downstream enzymes were activated 12 days after treatment. Cluster analysis confirmed the concordant activities of the flower- and silique-specific bHLH25 transcription factor and the key enzyme in the TIA biosynthesis pathway, e.g., STR. Due to the stepwise response of the two sets of pathways, we speculate that enzymes activated earlier likely make TIA biosynthesis pathway a more favourable target in C. roseus than anthocyanin biosynthesis pathway.