Reactive Extraction of Citric Acid Using Different Extractants: Equilibrium, Kinetics and Modeling

Recovery of citric acid from biotechnologically produced low concentration aqueous solution has attracted several separation techniques for the downstream processing. Amongst them, reactive extraction is a convenient, cheap, and effective method. Three different extractants are used in this study, namely tri-n-butyl phosphate (TBP), tri-n-octylamine (TOA), and Aliquat 336 (A336), all diluted in methyl-iso-butyl ketone (MIBK). The isothermal batch experiments were performed for the equilibrium and kinetic studies at T = 300.15±1 K. Around 92 % extraction efficiency (E %) was obtained using 20 % (v/v) TOA in MIBK. Based on the overloading of amine (Z > 0.5), (2:1) acid:extractant complex in TOA+MIBK phase was proposed. Kinetics of extraction of citric acid (0.2–0.8 kmol m–3) was also performed in a Lewis-type stirred cell, using TOA in MIBK. The extraction reaction was occurring in the diffusion film. The second order rate constant was calculated as k2 = 0.0351 m3 kmol–1 s–1. The extraction parameters were estimated by differential evolution optimization technique. Optimal value of equilibrium constant, KE, was found to be 3.6 · 10–3 (m3 kmol–1)2, for the reactive extraction of citric acid using 20 % TOA in MIBK, and was found in close agreement with experimental values. This work is licensed under a Creative Commons Attribution 4.0 International License

Utilisation of sea nodules leaching residue for adsorption of Ni(II) ions

Polymetallic sea nodules may be considered as lean grade ore of Cu, Ni & Co. After recovery of these valuable metals, a huge quantity of residue (~70% of ore body) is generated. In the present paper, investigations carried out for the application of leached sea nodule residue for the removal of Ni(II) from aqueous solution by adsorption, are described. Several parameters have been varied to study the feasibility of using residue as potential adsorbent for remediation Ni(II) contaminated water. The adsorption kinetics followed pseudo first-order equation and the rate of adsorption increased with solution temperature. Kinetics data of Ni(II) adsorption was also discussed using diffusion models of Webber-Morris and Dumwald-Wagner models. The equilibrium data was best fitted into Langmuir adsorption isotherm and the maximum adsorption capacities was found to be 15.15 mg g-1 at pH 5.5 and temperature 303 K, which decreased to 10.64 mg g-1 upon raising the solution temperature to 323 K. The activation energy for Ni(II) adsorption onto leached sea nodule residue was 9.56 kJ mol−1 indicated physical sorption. Desorption studies showed successful regeneration of adsorbent and recovery of Ni. This process can be utilised for removal and recovery of Ni from the industrial effluent

Drug utilization pattern of antiseizure drugs and their adverse effects in the pediatric population, in a tertiary care hospital attached to a medical college

Background: Epilepsy is “a condition characterized by recurrent (two or more) seizure, unprovoked by any immediate identified cause.” The desired outcome of antiseizure drug (ASD) therapy is to be seizure-free throughout the rest of life. The objective was to study the utilization pattern and adverse drug reactions (ADRs) associated with the use of ASDs in pediatric outpatients in epilepsy clinic.Methods: This cross-sectional, observational and single center study was carried out over a period of 1 year in 430 pediatric patients. Analyzed data included demographic details and drugs prescribed in respective seizure types along with ADRs due to ASDs. Results: In a total 430 patients analyzed, seizure were most commonly observed in boys (69.8%) in 6-10 year of age (45.3%), with a positive family history in (16%), with no specific cause of seizure in (71.6%), with most common type was focal seizure in (62.3%), which was mainly treated with carbamazepine (73.8%). Most common ADR was irritability (32.2%) with Valproate being main drug. 87.3% ADRs were in “ possible” as per World Health Organization causality assessment scale, 94.9% ADRs were “mild” as per Hartwig and Siegel severity assessment scale and 98.3% ADRs were “preventable” as per Schumock and Thornton preventability scale.Conclusion: Focal seizure was most common type of seizure observed mainly in boys of 6-10 year with carbamazepine as mainly prescribed drug. Use of appropriate ASDs in the majority of patients as per guidelines, has decreased number of ADRs in our study. Prescribing drugs were mainly from essential drug list and by generic names

Seasonal distribution of benthic foraminifera at Nana Layja, Kachchh, Gujarat – India

648-657Benthic foraminiferal abundance from three sites at Nana Layja from the coast of Kachchh was studied over a period of one year to determine the seasonal variability. All the three sites were dominated by Ammonia beccarii (Brunnich, 1772), Pararotalia calcariformata (Le Calvez, 1949), Elphidium advenum (Haynes, 1973), Eponides repandus (Montfort, 1808) and Quinqueloculina bosciana (d'Orbigny, 1826). These showed considerable seasonal variability at the studied three sites. The maximum total foraminiferal abundance was found on December 2016 while the minimum was observed on June 2017. A. beccarii, P. calcariformata, and E. repandus exhibited a seasonal pattern similar to the total foraminiferal abundance. Whereas, E. advenum and Q. bosciana showed a different pattern of abundance with the minimum and maximum abundances found in December 2016 and June 2017, respectively. Other two rare species recorded were Spiroloculina sp. 1 (Alcide d'Orbigny, 1826) and Rosalina globularis (Alcide d'Orbigny, 1826) in all the seasons. Species diversity analysis showed that the three sites are rich in species variability with a high Shannon−Weiner Index and low Evenness Index. The physicochemical characterization of seawater collected from three sites showed distinct seasonal variations

Analysis of Single-Cell RNA-Seq Identifies Cell-Cell Communication Associated with Tumor Characteristics

Tumor ecosystems are composed of multiple cell types that communicate by ligand-receptor interactions. Targeting ligand-receptor interactions (for instance, with immune checkpoint inhibitors) can provide significant benefits for patients. However, our knowledge of which interactions occur in a tumor and how these interactions affect outcome is still limited. We present an approach to characterize communication by ligand-receptor interactions across all cell types in a microenvironment using single-cell RNA sequencing. We apply this approach to identify and compare the ligand-receptor interactions present in six syngeneic mouse tumor models. To identify interactions potentially associated with outcome, we regress interactions against phenotypic measurements of tumor growth rate. In addition, we quantify ligand-receptor interactions between T cell subsets and their relation to immune infiltration using a publicly available human melanoma dataset. Overall, this approach provides a tool for studying cell-cell interactions, their variability across tumors, and their relationship to outcome. Tumors are composed of cancer cells and many non-malignant cell types, such as immune and stromal cells. To better understand how all cell types in a tumor cooperate to facilitate malignant growth, Kumar et al. studied communication between cells via ligand and receptor interactions using single-cell data and computational modeling. Keywords: computational analysis; single-cell RNA sequencing; cell-cell communication; ligand-receptor interaction; tumor microenvironment; syngeneic mouse models; cancer patient samplesNational Institute of General Medical Sciences (U.S.) (Grant T32-GM008334)National Cancer Institute (U.S.) (Grant U01-CA215798

Allelic dimorphism of Plasmodium vivax gam-1 in the Indian subcontinent

BACKGROUND: Genetic polymorphism is an inevitable component of a complex organism especially in multistage infectious organisms such as malaria parasites. Understanding the population genetic structure of the parasites would provide valuable information for effective malaria control strategies. Recently, the development of molecular tools like PCR has made analysis of field samples possible and easier and research on Plasmodium vivax has also been strengthened. Not many reports are available on the genetic polymorphism of P. vivax from the Indian sub-continent. This study evaluates the extent of diversity in field isolates of India with respect to Pvgam-1. METHODS: A study was designed to assess the diversity of Pvgam-1 among field isolates from India, using a nested PCR assay. Field isolates were collected from different regions of the country and the observed variability was confirmed by sequencing data. RESULTS: Both Belem and Chesson type alleles were present either exclusively or in mixed form among isolates of all 10 study sites. The Belem type allele was predominant, occurring in 67% of isolates. The proportion of isolates showing the mixed form (both Belem and Chesson type alleles occurring together in the same isolate) was about 13 overall (up to 38.5% in some isolates). Sequencing of the PCR-amplified Belem and Chesson type alleles confirmed the PCR results. Among the 10 study sequences, 11 polymorphic sites and four singleton variations were observed. All the nucleotide substitutions were non-synonymous. CONCLUSION: Study shows limited diversity of Pvgam-1 marker in Indian isolates with well representation of both Belem and Chesson type alleles