This review aims to provide an overview of homogeneous liquid–liquid extraction (HLLE) and dispersive liquid–liquid microextraction (DLLME) methods and their potential use in inorganic analysis. ...Relevant applications to the determination of metal ions, metalloids and organometals are included. The phase separation mechanisms of these unconventional solvent extraction techniques are discussed. The new trends in the field of miniaturization and automation are presented, while proposing future trends and potential new areas for their application.
A simple, sensitive and powerful on-line sequential injection (SI) dispersive liquid–liquid microextraction (DLLME) system was developed as an alternative approach for on-line metal preconcentration ...and separation, using extraction solvent at microlitre volume. The potentials of this novel schema, coupled to flame atomic absorption spectrometry (FAAS), were demonstrated for trace copper and lead determination in water samples. The stream of methanol (disperser solvent) containing 2.0% (v/v) xylene (extraction solvent) and 0.3% (m/v) ammonium diethyldithiophosphate (chelating agent) was merged on-line with the stream of sample (aqueous phase), resulting a cloudy mixture, which was consisted of fine droplets of the extraction solvent dispersed entirely into the aqueous phase. By this continuous process, metal chelating complexes were formed and extracted into the fine droplets of the extraction solvent. The hydrophobic droplets of organic phase were retained into a microcolumn packed with PTFE-turnings. A portion of 300
μL isobutylmethylketone was used for quantitative elution of the analytes, which transported directly to the nebulizer of FAAS. All the critical parameters of the system such as type of extraction solvent, flow-rate of disperser and sample, extraction time as well as the chemical parameters were studied. Under the optimum conditions the enhancement factor for copper and lead was 560 and 265, respectively. For copper, the detection limit and the precision (R.S.D.) were 0.04
μg
L
−1 and 2.1% at 2.0
μg
L
−1 Cu(II), respectively, while for lead were 0.54
μg
L
−1 and 1.9% at 30.0
μg
L
−1 Pb(II), respectively. The developed method was evaluated by analyzing certified reference material and applied successfully to the analysis of environmental water samples.
A novel on-line sequential injection (SI) dispersive liquid–liquid microextraction (DLLME) system coupled to electrothermal atomic absorption spectrometry (ETAAS) was developed for metal ...preconcentration in micro-scale, eliminating the laborious and time consuming procedure of phase separation with centrifugation. The potentials of the system were demonstrated for trace lead and cadmium determination in water samples. An appropriate disperser solution which contains the extraction solvent (xylene) and the chelating agent (ammonium pyrrolidine dithiocarbamate) in methanol is mixed on-line with the sample solution (aqueous phase), resulting thus, a cloudy solution, which is consisted of fine droplets of xylene, dispersed throughout the aqueous phase. Three procedures are taking place simultaneously: cloudy solution creation, analyte complex formation and extraction from aqueous phase into the fine droplets of xylene. Subsequently the droplets were retained on the hydrophobic surface of PTFE-turnings into the column. A part of 30
μL of the eluent (methyl isobutyl ketone) was injected into furnace graphite for analyte atomization and quantification. The sampling frequency was 10
h
−1, and the obtained enrichment factor was 80 for lead and 34 for cadmium. The detection limit was 10
ng
L
−1 and 2
ng
L
−1, while the precision expressed as relative standard deviation (RSD) was 3.8% (at 0.5
μg
L
−1) and 4.1% (at 0.03
μg
L
−1) for lead and cadmium respectively. The proposed method was evaluated by analyzing certified reference materials and was applied to the analysis of natural waters.
The behaviour of pre-code reinforced concrete (RC) columns in sequence of fire and earthquake is not well understood and can be critical in case of buildings which experienced fire and are either ...unrepaired or poorly repaired when exposed to an earthquake. This study proposes a framework on how to construct a simplified model to assess the post-fire cyclic behaviour of such columns. Emphasis is given to the development of simplified material models which can be used to describe the performance of the confined concrete, as its post-fire behaviour is not well studied. The model's performance is validated against the experimental results of a square, non-seismically designed RC column. Three scenarios are considered. The reference scenario, where the column is exposed only to cyclic loading. In the other two, the column is firstly exposed to an ISO-834 time-temperature curves in a furnace of 30 min and 90 min duration and after it cooled down, it is exposed to cyclic loading. The results showed that simplified material models can be used to capture the post-fire cyclic behaviour of an RC column, built without seismic design. It was also found that the confined model adopted played an important role after the peak strength is reached.
P-type Bi0.3Sb1.7Te3 polycrystalline pellets were fabricated using different methods: melting and mechanical alloying, followed by hot-press sintering. The effect of starting powder particle size on ...the thermoelectric properties was investigated in samples prepared using powders of different particle sizes (with micro- and/or nano-scale dimensions). A peak ZT (350 K) of ~1.13 was recorded for hot-pressed samples prepared from mechanical alloyed powder. Moreover, hot-pressed samples prepared from ≤45 μm powder exhibited similar ZT (~1.1). These high ZT values are attributed both to the presence of high-density grain boundaries, which reduced the lattice thermal conductivity, as well as the formation of antisite defects during milling and grinding, which resulted in lower carrier concentrations and higher Seebeck coefficient values. In addition, Bi0.3Sb1.7Te3 bulk nanocomposites were fabricated in an attempt to further reduce the lattice thermal conductivity. Surprisingly, however, the lattice thermal conductivity showed an unexpected increasing trend in nanocomposite samples. This surprising observation can be attributed to a possible overestimation of the lattice thermal conductivity component by using the conventional Wiedemann–Franz law to estimate the electronic thermal conductivity component, which is known to occur in nanocomposite materials with significant grain boundary electrical resistance.
There are several studies on the deregulated gene expression profiles in kidney cancer, with varying results depending on the tumor histology and other parameters. None of these, however, have ...identified the networks that the co-deregulated genes (co-DEGs), across different studies, create. Here, we reanalyzed 10 Gene Expression Omnibus (GEO) studies to detect and annotate co-deregulated signatures across different subtypes of kidney cancer or in single-gene perturbation experiments in kidney cancer cells and/or tissue. Using a systems biology approach, we aimed to decipher the networks they form along with their upstream regulators. Differential expression and upstream regulators, including transcription factors MYC proto-oncogene (MYC), CCAAT enhancer binding protein delta (CEBPD), RELA proto-oncogene, NF-kB subunit (RELA), zinc finger MIZ-type containing 1 (ZMIZ1), negative elongation factor complex member E (NELFE) and Kruppel-like factor 4 (KLF4) and protein kinases Casein kinase 2 alpha 1 (CSNK2A1), mitogen-activated protein kinases 1 (MAPK1) and 14 (MAPK14), Sirtuin 1 (SIRT1), Cyclin dependent kinases 1 (CDK1) and 4 (CDK4), Homeodomain interacting protein kinase 2 (HIPK2) and Extracellular signal-regulated kinases 1 and 2 (ERK1/2), were computed using the Characteristic Direction, as well as GEO2Enrichr and X2K, respectively, and further subjected to GO and KEGG pathways enrichment analyses. Furthermore, using CMap, DrugMatrix and the LINCS L1000 chemical perturbation databases, we highlight putative repurposing drugs, including Etoposide, Haloperidol, BW-B70C, Triamterene, Chlorphenesin, BRD-K79459005 and β-Estradiol 3-benzoate, among others, that may reverse the expression of the identified co-DEGs in kidney cancers. Of these, the cytotoxic effects of Etoposide, Catecholamine, Cyclosporin A, BW-B70C and Lasalocid sodium were validated in vitro. Overall, we identified critical co-DEGs across different subtypes in kidney cancer, and our results provide an innovative framework for their potential use in the future.
•Different response of reinforced concrete frame to earthquake and tsunami.•The prior earthquake slightly influences the earthquake-tsunami fragility curves.•Column shear failure is found to govern ...collapse mechanism under tsunami.
Many coastal regions lying on subduction zones are likely to experience the catastrophic effects of cascading earthquake and tsunami observed in recent events, e.g., 2011 Tohoku Earthquake and Tsunami. The influence of earthquake on the response of the structure to tsunami is difficult to quantify through damage observations from past events, since they only provide information on the combined effects of both perils. Hence, the use of analytical methodologies is fundamental. This paper investigates the response of a reinforced concrete frame subjected to realistic ground motion and tsunami inundation time histories that have been simulated considering a seismic source representative of the M9 2011 Tohoku earthquake event. The structure is analysed via nonlinear time-history analyses under (a) tsunami inundation only and (b) earthquake ground motion and tsunami inundation in sequence. Comparison of these analyses shows that there is a small impact of the preceding earthquake ground shaking on the tsunami fragility. The fragility curves constructed for the cascading hazards show less than 15% reduction in the median estimate of tsunami capacity compared to the fragility functions for tsunami only. This outcome reflects the fundamentally different response of the structure to the two perils: while the ground motion response of the structure is governed by its strength, ductility and stiffness, the tsunami performance of the structure is dominated by its strength. It is found that the ground shaking influences the tsunami displacement response of the considered structure due to the stiffness degradation induced in the ground motion cyclic response, but this effect decreases with increasing tsunami force.
A novel, automatic on-line sequential injection dispersive liquid–liquid microextraction (SI-DLLME) method, based on 1-hexyl-3-methylimidazolium hexafluorophosphate (HmimPF
6
) ionic liquid as an ...extractant solvent was developed and demonstrated for trace thallium determination by flame atomic absorption spectrometry. The ionic liquid was on-line fully dispersed into the aqueous solution in a continuous flow format while the TlBr
4
−
complex was easily migrated into the fine droplets of the extractant due to the huge contact area of them with the aqueous phase. Furthermore, the extractant was simply retained onto the surface of polyurethane foam packed into a microcolumn. No specific conditions like low temperature are required for extractant isolation. All analytical parameters of the proposed method were investigated and optimized. For 15 mL of sample solution, an enhancement factor of 290, a detection limit of 0.86 μg L
−1
and a precision (RSD) of 2.7% at 20.0 μg L
−1
Tl(I) concentration level, was obtained. The developed method was evaluated by analyzing certified reference materials while good recoveries from environmental and biological samples proved that present method was competitive in practical applications.
Figure
An automatic sequential injection dispersive liquid-liquid microextraction (SI-DLLME) system for thallium determination
A novel, simple and efficient sequential injection (SI) on-line dispersive liquid–liquid microextraction (DLLME) procedure was described and was demonstrated for the assay of trace silver ...determination by flame atomic absorption spectrometry (FAAS). Fatty alcohols, such as 1-undecanol and 1-dodecanol, were examined as extraction solvents at microlitre volume, overcoming a major problem of the DLLME methods, the high toxicity of the extraction solvents used. Furthermore, the extractant fine droplets can be easily separated from the aqueous phase using a micro-column packed with a novel hydrophobic sorbent material, poly(etheretherketone)-turnings. In this method fine droplets of 1-dodecanol were on-line generated and dispersed into the stream of aqueous sample. By this continuous process, silver diethyldithiocarbamate (Ag-DDTC) complex was formed and extracted into the dispersed extraction solvent. No specific conditions such as ice bath for low temperature or special tools are required for extractant isolation. All significant parameters that influence the efficiency of the system such as sample acidity, concentration of complexing reagent and extraction solvent, flow-rate of disperser and sample solution as well as the preconcentration time were investigated and optimized by full factorial design. Under the optimized conditions a detection limit of 0.15μgL−1, a relative standard deviation (RSD) of 2.9% at 5.00μgL−1 Ag(I) concentration level and an enhancement factor of 186 were obtained. The developed method was evaluated by analyzing certified reference material and was applied successfully to the analysis of environmental water samples.
The aim of the present study was to select the optimal extraction conditions for two underutilized wild fruits of the Rosaceae family (Mespilus germanica and Crataegus azarolus) in order to ...investigate the possibility of utilizing their potential bioactive properties by developing novel fermented milk drinks enriched with fruit extracts, with functional properties. The total phenolic and flavonoid contents of the extracts, as well as their antioxidant and antidiabetic activities, were evaluated, and based on the results, the optimal extraction conditions were selected. The technological characteristics (i.e., fermentation conditions) and microbiological and bioactive properties of the final products were evaluated over refrigerated storage for 28 days. The findings of the study showed that the incorporation of Mespilus germanica or Crataegus azarolus extracts had a positive influence on the bioactive properties of the end-products, decreased fermentation times and maintained high viable populations of lactic acid bacteria. Hence, it can be concluded that Mespilus germanica or Crataegus azarolus extracts can be exploited in the enrichment of an added-value fermented milk drink.
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