Leaching kinetics of copper from waste printed circuit boards by electro-generated chlorine in HCl solution

The leaching behavior of metals such as copper, zinc, lead and tin from waste printed circuit boards (PCBs) has been investigated using electro-generated chlorine in hydrochloric acid solution. The experiments were carried out by employing two different reactors: (a) a combined reactor facilitated with simultaneous Cl2 generation and metal leaching, and (b) a separate metal leaching reactor connected with the anode compartment of a Cl2 gas generator. Leaching efficiency in two reactors was compared for recycling of valuable metals from the PCBs. It was observed that the leaching rate of the metals increased with increase in current density, temperature and time in both reactors. The copper leaching rate gradually diminished when its dissolution was around 20 and 25% in the combined and separate reactor, respectively, which may be attributed to a decrease in surface area of copper with leaching time and the formation of CuCl(s) on the surface. The leaching efficiency of copper was found to be lower in the combined reactor than that of the separate reactor. The dissolution kinetics of copper with electro-generated chlorine followed empirical logarithmic law controlled by surface layer diffusion. The leaching mechanism of copper was further corroborated by SEM-EDS study of the residue. The activation energy for copper leaching in the combined and separate reactors was calculated to be 24.5 and 20.7 kJ/mol, respectively in the temperature range 298–323 K

Orbital Variations of Biogenic CaCO3 and Opal Abundance in the Western and Central Equatorial Pacific Ocean During the Late Quaternary

Biogenic CaCO3 and opal abundances were measured in two piston cores (PC313 and PC5101) collected, respectively, along the equator in the western and central Pacific Ocean. The age model for core PC313, which extends to about 750 ka, was developed by comparing the oxygen isotope stratigraphy of planktonic foraminifera (N. dutetrei) to the SPECMAP stack. The age model for core PC5101, which extends to about 600 ka, was developed by stratigraphic correlation of CaCO3 contents to those in the well-dated core RC11-210 (Chuey et al. 1987). Both cores distinctly exhibited a series of CaCO3 and opal variations, which are mainly controlled by the orbital eccentricity cycle of about 100-kyr. The orbital-scale cyclic variations of CaCO3 and opal contents appear to be contrasting in both cores such that high CaCO3 and low opal contents occurred during the glacial periods. In contrast, during the interglacial periods, low CaCO3 and high opal contents occurred. Mostly remarkable is the distinct occurrence of a mid-Bruhnes event (MBE) at around 350 ka. The CaCO3 content was higher in core PC5101 than in core PC313 before the MBE, whereas biogenic opal abundance became higher in core PC5101 after the MBE. Such a characteristic discrepancy of biogenic (CaCO3 and opal) production, i.e., a succession of primary producers from coccolithophore to diatom, between cores PC313 and PC5101 may be attributed to the prevailing dominant hydrographic conditions (i.e., the South Equatorial Current), in the path of which both cores are located. The intensity of westward propagation might have been an important factor in contrasting biogenic production centering around the MBE

Large scale and integrated platform for digital mass culture of anchorage dependent cells

Industrial applications of anchorage-dependent cells require large-scale cell culture with multifunctional monitoring of culture conditions and control of cell behaviour. Here, we introduce a large-scale, integrated, and smart cell-culture platform (LISCCP) that facilitates digital mass culture of anchorage-dependent cells. LISCCP is devised through large-scale integration of ultrathin sensors and stimulator arrays in multiple layers. LISCCP provides real-time, 3D, and multimodal monitoring and localized control of the cultured cells, which thereby allows minimizing operation labour and maximizing cell culture performance. Wireless integration of multiple LISCCPs across multiple incubators further amplifies the culture scale and enables digital monitoring and local control of numerous culture layers, making the large-scale culture more efficient. Thus, LISCCP can transform conventional labour-intensive and high-cost cell cultures into efficient digital mass cell cultures. This platform could be useful for industrial applications of cell cultures such as in vitro toxicity testing of drugs and cosmetics and clinical scale production of cells for cell therapy.

Effects of Inositol 1,4,5-triphosphate on Osteoclast Differentiation in RANKL-induced Osteoclastogenesis

The receptor activator of NF-κB ligand (RANKL) signal is an activator of tumor necrosis factor receptor-associated factor 6 (TRAF6), which leads to the activation of NF-κB and other signal transduction pathways essential for osteoclastogenesis, such as Ca2+ signaling. However, the intracellular levels of inositol 1,4,5-trisphosphate (IP3) and IP3-mediated cellular function of RANKL during osteoclastogenesis are not known. In the present study, we determined the levels of IP3 and evaluated IP3-mediated osteoclast differentiation and osteoclast activity by RANKL treatment of mouse leukemic macrophage cells (RAW 264.7) and mouse bone marrow-derived monocyte/macrophage precursor cells (BMMs). During osteoclastogenesis, the expression levels of Ca2+ signaling proteins such as IP3 receptors (IP3Rs), plasma membrane Ca2+ ATPase, and sarco/endoplasmic reticulum Ca2+ ATPase type2 did not change by RANKL treatment for up to 6 days in both cell types. At 24 h after RANKL treatment, a higher steady-state level of IP3 was observed in RAW264.7 cells transfected with green fluorescent protein (GFP)-tagged pleckstrin homology (PH) domains of phospholipase C (PLC) δ, a probe specifically detecting intracellular IP3 levels. In BMMs, the inhibition of PLC with U73122 [a specific inhibitor of phospholipase C (PLC)] and of IP3Rs with 2-aminoethoxydiphenyl borate (2APB; a non-specific inhibitor of IP3Rs) inhibited the generation of RANKL-induced multinucleated cells and decreased the bone-resorption rate in dentin slice, respectively. These results suggest that intracellular IP3 levels and the IP3-mediated signaling pathway play an important role in RANKL-induced osteoclastogenesis

Variation block-based genomics method for crop plants

BACKGROUND: In contrast with wild species, cultivated crop genomes consist of reshuffled recombination blocks, which occurred by crossing and selection processes. Accordingly, recombination block-based genomics analysis can be an effective approach for the screening of target loci for agricultural traits. RESULTS: We propose the variation block method, which is a three-step process for recombination block detection and comparison. The first step is to detect variations by comparing the short-read DNA sequences of the cultivar to the reference genome of the target crop. Next, sequence blocks with variation patterns are examined and defined. The boundaries between the variation-containing sequence blocks are regarded as recombination sites. All the assumed recombination sites in the cultivar set are used to split the genomes, and the resulting sequence regions are termed variation blocks. Finally, the genomes are compared using the variation blocks. The variation block method identified recurring recombination blocks accurately and successfully represented block-level diversities in the publicly available genomes of 31 soybean and 23 rice accessions. The practicality of this approach was demonstrated by the identification of a putative locus determining soybean hilum color. CONCLUSIONS: We suggest that the variation block method is an efficient genomics method for the recombination block-level comparison of crop genomes. We expect that this method will facilitate the development of crop genomics by bringing genomics technologies to the field of crop breeding

Highly Pathogenic Avian Influenza Virus (H5N1) in Domestic Poultry and Relationship with Migratory Birds, South Korea

During the 2006–2007 winter season in South Korea, several outbreaks of highly pathogenic avian influenza virus (H5N1) were confirmed among domestic poultry and in migratory bird habitats. Phylogenetic analysis showed that all isolates were closely related and that all belong to the A/bar-headed goose/Qinghai/5/2005–like lineage rather than the A/chicken/Korea/ES/2003–like lineage

A Case of Postoperative Tuberculous Spondylitis with a Bizarre Course

Postoperative infections following spine surgery are usually attributable to bacterial organisms. Staphylococcus aureus is known to be the most common single pathogen leading to this infection, and the number of infections caused by methicillin-resistant Staphylococcus aureus is increasing. However, there is a paucity of literature addressing postoperative infection with Mycobacterium tuberculosis. We encountered a case of tuberculous spondylitis after spine surgery. A man had fever with low back pain three weeks after posterior interbody fusion with instrumentation for a herniated intervertebral disc at the L4-L5 level. He had been treated with antibiotics for an extended period of time under the impression that he had a bacterial infection, but his symptoms and laboratory data had not improved. Polymerase chain reaction for Mycobacterium tuberculosis turned out to be positive. The patient's symptoms finally improved when he was treated with antituberculosis medication

Expression of Ca2+-dependent Synaptotagmin Isoforms in Mouse and Rat Parotid Acinar Cells

Synaptotagmin is a Ca2+ sensing protein, which triggers a fusion of synaptic vesicles in neuronal transmission. Little is known regarding the expression of Ca2+-dependent synaptotagmin isoforms and their contribution to the release of secretory vesicles in mouse and rat parotid acinar cells. We investigated a type of Ca2+-dependent synaptotagmin and Ca2+ signaling in both rat and mouse parotid acinar cells using RT-PCR, microfluorometry, and amylase assay. Mouse parotid acinar cells exhibited much more sensitive amylase release in response to muscarinic stimulation than did rat parotid acinar cells. However, transient [Ca2+]i increases and Ca2+ influx in response to muscarinic stimulation in both cells were identical, suggesting that the expression or activity of the Ca2+ sensing proteins is different. Seven Ca2+-dependent synaptotagmins, from 1 to 7, were expressed in the mouse parotid acinar cells. However, in the rat parotid acinar cells, only synaptotagmins 1, 3, 4 and 7 were expressed. These results indicate that the expression of Ca2+-dependent synaptotagmins may contribute to the release of secretory vesicles in parotid acinar cells

The cascade of care for latent tuberculosis infection in congregate settings:a national cohort 1 analysis, Korea, 2017-18

BACKGROUND: In 2017, Korea implemented a nationwide project to screen and treat latent tuberculosis infection (LTBI) in high-risk for transmission public congregate settings. We aimed to assess programme success using a cascade of care framework. MATERIALS AND METHODS: We undertook a cohort study of people from three congregate settings screened between March 2017 and December 2018: (1) first-grade high school students, (2) employees of educational institutions, (3) employees of social welfare facilities. We report percentages of participants with LTBI completing each step in the cascade of care model. Poisson regression models were used to determine factors associated with not visiting clinics, not initiating treatment, and not completing treatment. RESULTS: Among the 96,439 participants who had a positive interferon-gamma release assay result, the percentage visiting clinics for further assessment, to initiate treatment, and who then completed treatment were 50.7, 34.7, and 28.9%, respectively. Compared to those aged 20-34 years, individuals aged < 20 years and aged ≥ 65 years were less likely to visit clinics, though more likely to complete treatment once initiated. Using public health centres rather than private hospitals was associated with people "not initiating treatment" (adjusted risk ratio [aRR], 3.72; 95% confidence interval [CI], 3.95-3.86). Nine-month isoniazid monotherapy therapy was associated with "not completing treatment," compared to 3-month isoniazid and rifampin therapy (aRR, 1.28; 95% CI, 1.16-1.41). CONCLUSION: Among participants with LTBI from three congregate settings, less than one third completed treatment. Age, treatment centre, and initial regimen were important determinants of losses to care through the cascade