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In this paper, according to the reaction principle and material balance, the coefficient calculation rule is established to construct the valuable element allocation model with Java programs in the hydrometallurgy process of cobalt-rich slag. Thus, the ratio of distribution in each process containing acid leaching, copper deposition, ferromanganese precipitation, and cobalt deposition are forecast quantitatively, accompanied by the recovery rate of the valuable element. Compared with the expanding process of cobalt-rich slag, the correctness and applicability of the model for the distribution and ratio of the valuable element are investigated, and the weak link can be improved according to the specific situation of the process. The recovery rate of cobalt is 95.38 %, and the content of cobalt in the cobalt product is 44.93 % in the cobalt deposition. Ultimately, the valuable element allocation model can quantitatively predict the experimental results, indicating that it can be used for simulating and optimizing the control of the hydrometallurgy process of cobalt-rich slag. This can improve the recovery rate of valuable elements in such hydrometallurgical processes. [ABSTRACT FROM AUTHOR]

N,N′-dioctyl-N,N′-di-dodecyl-3-oxapentane-1,5-diamide ((DdO)2DGA) is a novel unsymmetrical diglycolamide. Herein, we analyzed the third phase formation and extraction behavior of trivalent actinides and lanthanides with (DdO)2DGA in kerosene. Moreover, FT-IR and UV/Vis spectra of the extracted phase of Nd(III) with (DdO)2DGA were analyzed. The third phase is not formed by the extraction of Nd(III) with 0.10 mol/L (DdO)2DGA at 298 K. The metal ion distribution ratios increase with increased acidity and extractant concentration. Moreover, thermodynamic analysis demonstrates that the extraction is an exothermic reaction with ΔH = − 64.94 kJ/mol and ΔS = − 144.42 J/(mol·K). Both slope and spectroscopic analysis suggest that the extracted species is Nd(NO3)3·3(DdO)2DGA and the change in the acidity or extractant concentration will not change the extracted species. [ABSTRACT FROM AUTHOR]

A series of dialdehyde microcrystalline cellulose (DAMC) particles crosslinked with EPL (EPL-DAMCs) was successfully prepared by reacting DAMC with varying amounts of ε-Poly-L-lysine (EPL). Based on the excellent antibacterial property of ε-poly-L-lysine (EPL), the obtained EPL-DAMCs have a broad-spectrum antibacterial activity, and their physicochemical and antibacterial activities were also investigated. Fourier -transform infrared spectroscopy results demonstrated the formation of Schiff base between the aldehyde groups in DAMC and amino groups of EPL. The DAMC particles showed an aggregated structure of fibres. Among all DAMC crosslinked with EPL (EPL-DAMCs), the EPL-DAMC-4, with a lysine content of 0.46 ± 0.08 mg/g, showed the highest antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Salmonella typhimurium, with the minimum inhibitory concentration (MIC) of 3.75, 15.0, 7.5 and 3.75 mg/mL, respectively. Compared with DAMC, the EPL-DAMC-4 exhibited the better inhibition effect and antimicrobial stability on the tested strains. These findings suggested that EPL-DAMCs might be used as antimicrobial biomaterial and have great potential in food packaging field. [ABSTRACT FROM AUTHOR]

Hydrophilic 2,6-bis[1-(propan-1-ol)-1,2,3-triazol-4-yl)] pyridine (PyTri-Diol) was synthesized and tested for selective complexation of Am(III) into nitric acid solution from acidic bis(2-ethylhexyl)phosphoric (HDEHP) acid extractant. As the result of stripping experiments showed, PyTri-Diol dramatically promote Am(III) stripping in nitric acid up to 0.5 mol/L while the majority of Eu(III) was hold in the HDEHP phase. Separation factors in the range of 900 are achieved and PyTri-Diol remains active in nitric acid up to 0.5 mol/L without buffered solution or salting-out agent. The above properties of PyTri-Diol demonstrate the great potential for separating the minor actinides from the lanthanides in the TALSPEAK process. [ABSTRACT FROM AUTHOR]

Ficellomycin is an aziridine antibiotic produced by Streptomyces ficellus, which displays high in vitro activity against Gram-positive bacteria including multidrug resistant strains of Staphylococcus aureus. Compared to currently available antibiotics, ficellomycin exhibits a unique mechanism of action—it impairs the semiconservative DNA replication by inducing the formation of deficient 34S DNA fragments, which lack the ability to integrate into larger DNA pieces and eventually the complete bacterial chromosome. Until recently, some important progress has been made in research on ficellomycin synthesis and biosynthesis, opening the perspective to develop a new generation of antibiotics with better clinical performance than the currently used ones. In this review, we will cover the discovery and biological activity of ficellomycin, its biosynthesis, mode of action, and related synthetic analogs. The role of ficellomycin and its analogs as an important source of drug prototypes will be discussed together with future research prospects. [ABSTRACT FROM AUTHOR]

Ficellomycin is a peptide-like antibiotic which exhibits potent in vitro activity against Penicillium oxalicum and Staphylococcus aureus, even against strains resistant to most clinically used antibiotics. The gene cluster responsible for ficellomycin biosynthesis was cloned from Streptomyces ficellus and sequenced. It was found to contain 26 ORFs and is located within 30 kb of contiguous DNA. Targeted disruption of the encoding genes revealed that most were involved in the functional section of ficellomycin biosynthesis, such as peptide assembly, regulation, resistance, and biosynthesis of the precursor of ficellomycin 2-[4-guanidyl-1-azabicyclo[3.1.0]hexan-2-yl] glycine (2-GAHG). Within the 2-GAHG synthesis pathway, a sulfate adenylyltransferase appears to be involved in the synthesis of the pharmaceutically important 1-azabicyclo[3.1.0]hexane ring moiety, which has been reported to cause DNA cross-linking or impairment of semiconservative DNA replication. [ABSTRACT FROM AUTHOR]

Competitive complexation of solid lanthanide nitrates with tri-n-butyl phosphate (TBP) in n-hexane was studied by spectroscopic methods. For light lanthanides binary system (Nd-Pr), they complexed with TBP equally, leading to a low separation factor. However, distinct different behavior was observed for light-heavy lanthanides binary system (Nd-Ho). Heavy lanthanide Ho(NO)·6HO complexed preferentially with TBP, resulting in a much higher separation factor. The separation factor was low during HO stripping of lanthanides from their complexes in n-hexane, even thought, the tendency of stripping more light lanthanide was also observed. [ABSTRACT FROM AUTHOR]

In recent years, a great deal of interest has been focused on nitrogen-containing extractants for the separation of actinides from lanthanides. In this study, we synthesized a polyazamacrocycle-type C-cyclen ligand comprising four tertiary alkyl amino groups, for the extraction of Am and Eu. The C-cyclen demonstrated a weak ability to extract and separate Am and Eu that increased with the increasing 'softness' of the aqueous anions. The extraction behavior of Am and Eu indicated coordination interactions between the C-cyclen and the Am and Eu ions. The suppression of Am or Eu extraction by acid depended on the media anions involved. [ABSTRACT FROM AUTHOR]

Streptococcus zooepidemicus is a bacterial pathogen used for production of hyaluronan in industry. Intensive research has significantly contributed to our understanding of S. zooepidemicus biology and pathogenesis. However, the lack of an effective targeted gene inactivation system in S. zooepidemicus has notably prevented the functional genomics analysis of this gram-positive bacterium. Here, we report the development of a markerless gene deletion system in S. zooepidemicus. We constructed a sacB expression cassette on the thermosensitive suicide vector pSET4s and demonstrated its use as a counterselection marker in S. zooepidemicus. We validated the efficiency of this system by deletion of hasA, which synthesizes the important virulence factor hyaluronic acid (HA) capsule. The genotype of the resultant hasA mutant was confirmed by polymerase chain reaction and sequencing. Deletion of hasA resulted in non-mucoid morphology, loss of HA capsule formation, and HA production. These defects can be rescued by introduction of a plasmid containing wild-type hasA expression cassette. Moreover, compared with wild type, hasA mutant showed no significant difference in expressions of other members of the hasABCDE operon, further suggesting that the loss of hasA contributed to the defects observed with Δ hasA mutant. Our results describe the first establishment of a sacB-based counterselection system in S. zooepidemicus, along with the first demonstration of hasA that is the only gene encoding a functional hyaluronan synthase in this bacterium. [ABSTRACT FROM AUTHOR]

Variations of U-slot and pair of rectangular slots (E-shape) cut rectangular and square microstrip antenna are reported for the circularly polarized response. In the reported literature, details about the functioning of the two designs in terms of the resonant modes present, with a comparison amongst them, are not discussed. This paper provides a detailed review-based study to explain the functioning of the resonant slot-cut circular polarized microstrip antenna in terms of the resonant modes present. This study reveals that TM11 mode in an E-shape microstrip antenna and degenerated TM10 modes in a U-slot design yield the circularly polarized response. Amongst the two, U-slot cut design offers stable gain characteristics across the axial ratio bandwidth and offers a dual-band frequency response. A design methodology based on the resonant length formulation is presented that helps in realizing both the circularly polarized configurations as per the given frequency of interest. Thus, the present work provides a detailed review-based study about the functioning of resonant slot-cut microstrip antenna and its design methodology, which is not discussed in the reported literature. [ABSTRACT FROM AUTHOR]

Serine can regulate selenoprotein expression, and dietary serine is correlated with the contents of plasma selenoprotein P (Sepp1) and milk selenium (Se) in lactating mothers. Based on this, we investigated the effects of serine supplementation in the diets of late gestating and lactating sows on Sepp1 and Se contents in sows and their offspring. A total of 72 sows were assigned to four groups. During the experiment, sows were fed either a basal diet or basal diets supplemented with three different levels of serine. The results showed that maternal dietary serine had no effect on the Se content in the serum of sows and their offspring, whereas it significantly increased the Se content in the liver of piglets at the age of 21 days. Maternal dietary serine significantly increased Sepp1 content, either in the serum of sows or that in their offspring at the ages of 3 days, 7 days, and 21 days. Additionally, maternal dietary serine significantly increased litter weight and the average body weight of piglets at the age of 11 days. Notably, a positive correlation was found between the average body weight of piglets at the age of 11 days and serum Sepp1 content in piglets, at the age of either 3 days or 7 days. In conclusion, maternal dietary serine supplementation could improve Se nutritional status in sows and their offspring. These beneficial changes may contribute to the higher body weight of the offspring. [ABSTRACT FROM AUTHOR]