Comparative evaluation of extraction of tetra- and hexa-valent neptunium ions by CMPO in a room temperature ionic liquid

ABSTRACT

Solvent extraction studies were performed to understand the extraction behavior of Np⁴⁺ and NpO₂ ²⁺ from acidic feeds with CMPO (octyl (phenyl)-N,N-diisobutyl carbamoyl methyl phosphine oxide) dissolved in 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide, a water immiscible ionic liquid. Slope analyses on the distribution data revealed the extraction of ML₂ type species, where M = Np⁴⁺ or NpO₂ ²⁺, and L = CMPO. Studies were also carried out with Pu⁴⁺ and UO₂ ²⁺ under identical conditions. The nature of the extracted species was found to vary with the nature of the ionic species.     

Li4Ti5O12/Li3SbO4/C composite anode for high rate lithium-ion batteries

Nanocrystalline Li₄Ti₅O₁₂/Li₃SbO₄/C composite-prepared by mechanical ball-milling of Li₄Ti₅O₁₂ (synthesized by aqueous combustion), Li₃SbO₄ (synthesized by solid state method) and activated carbon, has been investigated as anode in lithium-ion coin cells and compared to pristine Li₄Ti₅O₁₂. Galvanostatic charge–discharge measurements in the potential window of 0.05–2.0 V show three plateau regions corresponding to Li insertion/extraction in the composite: a large flat plateau at ~ 1.52/1.59 V, followed by a second plateau at ~ 0.75/1.1 V and a sloppy tail at ~ 0.4/0.6 V. While the plateaus at ~ 0.4/0.6 V and ~ 1.52/1.59 V correspond to Li₄Ti₅O₁₂, the other one at ~ 0.75/1.1 V corresponds to Li₃SbO₄. At a high rate of ~ 15 C, the capacity for Li₄Ti₅O₁₂/Li₃SbO₄/C composite is found to be 105 mAhg^?1 retaining ~ 78% of its initial capacity compared to only 58 mAhg^?1 (~ 27% of the initial capacity) at 14 C for pristine Li₄Ti₅O₁₂ up to 100 cycles. Thus, such composite material might find application in lithium-ion batteries requiring high rate of charge and discharge.     

PYRENE ENCAPSULATED ALGINATE BEAD TYPE FOR SUSTAINED RELEASE IN BIODEGRADATION: PREPARATION AND CHARACTERISTICS

A novel method for preparation of pyrene encapsulated alginate beads for controlled release delivery of pyrene is reported in this study. Five different bead types that varied on the organic phase for pyrene delivery, presence or absence of polyvinyl alcohol (PVA) and boric acid treatment were prepared. Based on the pyrene release profile, silicone oil encapsulated in PVA-alginate bead was selected where encapsulation efficiency was more than 99% without any solvent leakage. Silicone oil encapsulation was further confirmed in microscopy observations. Pyrene release behavior from the beads was explained by a diffusion controlled first order release (R² > 0.96). Reusability of this bead was demonstrated, where pyrene was loaded from an external medium in a non-destructive way. Application of the system was finally established in a biodegradation study using Mycobacterium frederiksbergense, where simultaneous release and removal of pyrene along with appearance of pyrene metabolites was observed.     

Logistics planning and inventory optimization using swarm intelligence: a third party perspective

The economic and competitive pressures have made it imperative for organizations to focus on third party or outsourcing to reduce costs and improve operating efficiencies. The thrust of global economy drives the organizations to outsource process, parts, and labor, virtually anywhere in the world and get the desired combination of low cost and high quality. However, ineffective utilization of shipment practices in supply chain prevents to achieve the anticipated outsourcing benefits. In this research, a three-stage inventory model is developed to address the outsourcing issues with different shipment policies between manufacturer, exporter, and assembly point for any manufacturing industry. The model provides a measure for establishing an optimal balance between two conflicting objectives viz. net costs involved and the transportation discounts with consideration of holding cost at all the points in the supply chain. Owing to inherent computational complexities of the problem with higher dimensions, various deterministic approaches practically fail. Proposed work, therefore, utilizes a nature-inspired evolutionary algorithm, namely particle swarm optimization, to solve the problem. This paper applies enhanced particle swarm optimization, a variant of particle swarm optimization for solution purpose. Furthermore, the practical benefits and implications of the proposed model are demonstrated. The results obtained delineate efficacy to handle the fluctuations in the possible shipment options and simultaneously deciding the optimal shipment policies.     

Functional expression of the cystic fibrosis transmembrane conductance regulator in yeast

Recombinant human cystic fibrosis transmembrane conductance regulator (CFTR) has been produced in a Saccharomyces cerevisiae expression system used previously to produce transport ATPases with high yields. The arrangement of the bases in the region immediately upstream from the ATG start codon of the CFTR is extremely important for high expression levels. The maximal CFTR expression level is about 5-10% of that in Sf9 insect cells as judged by comparison of immunoblots. Upon sucrose gradient centrifugation, the majority of the CFTR is found in a light vesicle fraction separated from the yeast plasma membrane in a heavier fraction. It thus appears that most of expressed CFTR is not directed to the plasma membrane in this system. CFTR expressed in yeast has the same mobility (ca. 140 kDa) as recombinant CFTR produced in Sf9 cells in a high resolution SDS-PAGE gel before and after N-glycosidase F treatment, suggesting that it is not glycosylated. The channel function of the expressed CFTR was measured by an isotope flux assay in isolated yeast membrane vesicles and single channel recording following reconstitution into planar lipid bilayers. In the isotope flux assay, protein kinase A (PKA) increased the rate of 125I- uptake by about 30% in membrane vesicles containing the CFTR, but not in control membranes. The single channel recordings showed that a PKA-activated small conductance anion channel (8 pS) with a linear I-V relationship was present in the CFTR membranes, but not in control membranes. These results show that the human CFTR has been expressed in functional form in yeast. With the reasonably high yield and the ability to grow massive quantities of yeast at low cost, this CFTR expression system may provide a valuable new source of starting material for purification of large quantities of the CFTR for biochemical studies.     

High levels of spontaneous and parasite antigen-driven interleukin-10 production are associated with antigen-specific hyporesponsiveness in human lymphatic filariasis

To determine whether counterregulation by interleukin (IL)-10 plays a role in the generation or maintenance of the antigen-specific hyporesponsiveness seen in asymptomatic microfilaremic (MF) patients, parasite antigen (PAg)- and nonparasite antigen (NPAg)-driven IL-10 production by peripheral blood mononuclear cells (PBMC) was studied in 10 MF patients and in ll patients with chronic lymphatic pathology (CP). PBMC from MF patients spontaneously secreted 10-fold more IL-10 than did PBMC from patients with CP. PAg also induced significantly more IL-10 production by PBMC from CP patients. There was a negative correlation between PAg driven IL-10 production by PBMC and PAg-specific T cell proliferation in the MF group. IL-10 secretion by plastic adherent cells from MF persons was higher in response to PAg than NPAg, whereas IL-6 and tumor necrosis factor-alpha secretion were equivalent for PAg and NPAg, suggesting that PAg preferentially induces IL-10 secretion in these cells. Thus, PAg-induced IL-10 likely plays an important role in down-regulating antigen-specific proliferative responses in MF patients.     

IL-4- and IL-5-secreting lymphocyte populations are preferentially stimulated by parasite-derived antigens in human tissue invasive nematode infections

Helminth infections in humans and animals are associated with strong T helper 2 (Th2) responses. To determine whether parasite-derived Ag preferentially expand a Th2-like cell population, a filter immunoplaque assay was used to enumerate the frequencies (F0) of PBMC and CD4(+)-enriched PBMC from individuals with helminth infections secreting selected cytokines in response to parasite-derived (PAg) and nonparasite antigens (NPAg). In 20 individuals with lymphatic filariasis, frequency analysis of PBMC secreting IL-4 and IFN-gamma indicated that the F0 of PAg-specific IL-4-secreting cells (geometric mean F0 (GM): 1/12,100) was 57-fold higher than the corresponding F0 of NPAg-reactive cells (GM: 1/692,000; p < 0.02). In marked contrast, the F0 of IFN-gamma-secreting cells responding to PAg (GM: 1/2,700) did not differ from those of cells specific for NAPg (GM: 1/3,400; p = 0.83). In another group of helminth-infected individuals, the F0 of highly enriched CD4+ cells secreting IL-4 and IL-5 in response to PAg (GMs: 1/2,600 and 1/5,600 CD4+ cells, respectively) were also found to be significantly higher than those specific for NPAg (GMs: 1/291,000 and 1/303,000 CD4+; p < 0.05 and p < 0.01, respectively), whereas the corresponding F0 of IFN-gamma- and granulocyte-macrophage-CSF-secreting cells were equivalent for PAg and NPag. Furthermore, the proportion of PAg-specific IL-4- and IL-5-secreting CD4+ cells relative to all cells secreting the given cytokine were approximately 29-fold higher than the proportion of NPAg-specific cells secreting these cytokines. Again, the corresponding proportions of Ag-specific IFN-gamma-and GM-CSF-secreting CD4+ cells were equivalent for PAg and NPAg. Thus, in this ex vivo system, a circulating population of IL-4- and IL-5-secreting (Th2-like) cells has been shown to exist in humans; PAg appears to expand these cells preferentially.     

Optimal dual-channel supply chain configuration for product categories with different customer preference of online channel

This study addresses the supply chain configuration problem of manufacturer faced with multiple channel choices. We investigate the optimal combination of traditional and online sales channels for different product categories with differing customer preference of the online channel. We have considered three distinct dual-channel supply chain configurations comprising of a manufacturer, a traditional channel and an online channel viz. retailer–e-tailer; company store–e-tailer; and retailer–e-marketplace. As the manufacturer will face a quantity allocation decision between traditional and online channels, the competition is modeled using Cournot model with the manufacturer as the Stackelberg leader. Values of optimal order quantity and price for the different entities have been established. Influence of variation in customer preference of online channel on the optimal policies is also examined. We find that the manufacturer prefers retailer–e-marketplace configuration for products with high customer preference of online channel and company store–e-tailer configuration for products with low customer preference of online channel. In addition, we find that the retailer–e-tailer configuration is dominated by company store–e-tailer and retailer–e-marketplace configuration irrespective of the product’s customer preference of online channel.