Demulsification of stable W/O emulsions poses a challenge in crude oil processing. The terahertz pulse electric field is introduced to disrupt the hydrogen bond network between water molecules, ...enhancing water mobility in the oil phase and facilitating the rupture of the interface membrane for efficient oil-water separation. This presents a potential opportunity for economically streamlining of crude oil emulsions processing.
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•Introduction of a 1.0 THz pulse electric field disrupts the hydrogen bond network among water molecules, improving water mobility in the oil phase.•The increased self-diffusion coefficient indicates heightened penetration of water molecules into the interfacial region between the two phases.•The THz pulse electric field reduces oil-water interface tension, facilitating efficient coalescence of water droplets.•Altered interface structure is evidenced by the weakening of the electric double-layer structure at the oil-water interface.
Demulsifying highly stable W/O emulsions, composed of heavy oil and water, is crucial for simplifying crude oil processing, reducing production costs, and mitigating environmental pollution. In these emulsions, aromatic components in the oil phase stack via π-π interactions, while hydrogen bonds stabilize the water phase. This leads to the creation of a strong oil-water interface through electrostatic attraction, ultimately hindering water droplet coalescence and oil-water separation. In this study, a 1.0 THz pulse electric field is introduced to effectively disrupt the hydrogen bond network among water molecules by inducing hydrogen bond resonance. This disruption contributes to increased water mobility in the oil phase, weakened stability of the oil-water interface film, and facilitates efficient water droplet coalescence in the oil phase. The results show that throughout the demulsification process, the average number of hydrogen bonds per water molecule rapidly decreases from 1.41 to 1.08 within 100 ps. The upper and lower limits of hydrogen bond lifetimes decrease by 8.12 ps and 3.24ps, respectively. This indicates a significant disruption in the stability of hydrogen bonds between water molecules. Concurrently, the terahertz pulse electric field disrupts the initially stable oil-water interface film of the emulsion system, leading to a noteworthy reduction in the oil-water interface tension from 54.3 to 39.2 mN·m−1. The self-diffusion coefficient of water molecules increases from 1.33 to 2.62 Å2·ps−1, signifying that water molecules are more inclined to penetrate the interfacial region between the two phases. Additionally, the terahertz pulse electric field induces alterations in the arrangement of water molecules, resulting in the rearrangement of electrons in the water phase and disrupting the originally stable electrical double layer structure of the oil-water interface. This study provides novel insights into the development of efficient and environmentally friendly electric demulsification technologies, holding significant potential for widespread industrial applications.
HMSS was facilely synthesized by the Stöber method, where decane was first used to form the hollow structure. The HMSS shows an excellent adsorption property for MB from aqueous solutions with higher ...adsorption rate and capacity than reported.
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•Hollow mesoporous silica spheres were facilely synthesized with addition of decane.•The mesoporous channels perpendicular throughout the shell to the center of the HMSS.•The HMSS shows an excellent adsorption property for cationic organic dye from aqueous solutions.
Hollow mesoporous silica spheres (HMSS) were facilely synthesized by the Stöber method, in which decane was first used to form the hollow structure. The pore diameter of the mesoporous shell and the porous volume of the HMSS become higher with addition of decane. The average diameter of the HMSS is about 1100nm, the thickness of the shell is about 190nm. The mesoporous channels are perpendicular throughout the shell to the center of the HMSS. The HMSS shows an excellent adsorption property for cationic organic dye (methylene blue, MB) from aqueous solutions, such as higher adsorption rate and capacity than those reported.
The Asian tiger mosquito,
, is a competent vector for the majority of arboviruses. The mosquito innate immune response is a primary determinant for arthropod-borne virus transmission, and the midgut ...is the first barrier to pathogen transmission. Mosquito antiviral immunity is primarily mediated by the small interfering RNA pathway. However, the roles that the P-element induced wimpy testis (PIWI)-interacting RNA (piRNA) pathway play in antiviral immunity in
and its midgut still need further exploration. This study aimed to explore the profiles of both viral-derived and host-originated piRNAs in the whole body and midgut infected with Dengue virus 2 (DENV-2) in
, and to elucidate gene expression profile differences of the PIWI protein family between adult females and their midguts. A deep sequencing-based method was used to identify and analyze small non-coding RNAs, especially the piRNA profiles in DENV-2-infected
and its midgut. The top-ranked, differentially-expressed piRNAs were further validated using Stem-loop qRT-PCR. Bioinformatics analyses and reverse-transcription PCR (RT-PCR) methods were used to detect PIWI protein family members, and their expression profiles. DENV-2 derived piRNAs (vpiRNA, 24⁻30 nts) were observed in both infected
and its midgut; however, only vpiRNA in the whole-body library had a weak preference for adenine at position 10 (10A) in the sense molecules as a feature of secondary piRNA. These vpiRNAs were not equally distributed, instead they were derived from a few specific regions of the genome, especially several hot spots, and displayed an obvious positive strand bias. We refer to the differentially expressed host piRNAs after DENV infection as virus-induced host endogenous piRNAs (vepiRNAs). However, we found that vepiRNAs were abundant in mosquito whole-body tissue, but deficient in the midgut. A total of eleven PIWI family genes were identified in
; however, only AalPiwi5⁻7 and AalAgo3(1⁻2) were readily detected in the midgut. The characteristics of piRNAs in DENV-2-infected
adult females were similar to those previously described for flavivirus infections but were not observed in the midgut. The reduced levels of vepiRNAs and incomplete expression of PIWI pathway genes in midgut samples from DENV-2-infected
suggests that viral regulation of host piRNAs may not be an important factor in the midgut.
Aedes albopictus is one of the most invasive insect species in the world and an effective vector for many important arboviruses. We reported previously that Ae. albopictus Nix (AalNix) is the ...male-determining factor of this species. However, whether AalNix alone is sufficient to initiate male development is unknown. Transgenic lines that express each of the three AalNix isoforms from the native promoter were obtained using piggyBac transformation. We verified the stable expression of AalNix isoforms in the transgenic lines and confirm that one isoform, AalNix3&4, is sufficient to convert females into fertile males (pseudo-males) that are indistinguishable from wild-type males. We also established a stable sex-converted female mosquito strain, AalNix3&4-♂4-pseudo-male. The pseudo-male mosquitoes can fly and mate normally with wild-type female, although their mating competitiveness is lower than wild-type. This work further clarifies the role of AalNix in the sex determination pathway and will facilitate the development of Ae. albopictus control strategies that rely on male-only releases such as SIT and sex-ratio distortion.
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▶ Peroxo-molybdenum amino acid complexes were effective wide-ranging catalysts in ECODS. ▶ High desulfurization was not only in water-miscible IL but also in water-immiscible IL. ▶ ...The most difficult refractory compound, 4,6-DMDBT in HDS, can be removed completely. ▶ Reaction mechanism in water-miscible and water-immiscible ILs was investigated. ▶ Desulfurization difference between using simple catalysts and PMAACs was explained.
Three peroxo-molybdenum amino acid complexes (PMAACs) were synthesized and characterized. Their catalytic activities for oxidation of dibenzothiophene (DBT) in extraction and catalytic oxidative desulfurization system (ECODS) were evaluated using different ionic liquids. Comparing with simple catalyst Na
2MoO
4·2H
2O in ECODS, PMAACs were effective wide-ranging catalysts and exhibited high desulfurization efficiency not only in water-miscible IL bmimBF
4 but also in water-immiscible bmimPF
6, omimBF
4 and omimPF
6. Especially 4,6-dimethyldibenzothiophene (4,6-DMDBT), the most difficult refractory compound in HDS, could be completely removed under optimal conditions. The reaction mechanism and desulfurization differences between using Na
2MoO
4·2H
2O catalyst and PMAACs in water-miscible and water-immiscible ionic liquids have been investigated and explained by UV–vis. Kinetic parameters of the oxidation of DBT, BT and 4,6-DMDBT were studied.
Herein, we fabricate cuprous oxides within the pores of zeolite Y by the ion exchange and liquid reduction (LR) strategy combined with the confined effect of micropores. First, Cu2+ ions are ...incorporated into the pores of zeolite Y through ion exchange, and then part of Cu2+ ions within the pores of zeolite Y are reduced to cuprous oxide by using sodium borohydride as reducing agent. As-fabricated cuprous oxides within the confined pore of zeolite Y (Cu(I)–Y) adsorbent exhibits excellent adsorption desulfurization performance such as large breakthrough adsorption sulfur capacity of DBT (20.0 mg S g−1) and superior regeneration (15 cycles). The outstanding adsorption desulfurization performance could be attributed to the unique pore structure, proper pore sizes and π-complexation interaction between Cu(I) sites and aromatic sulfur compounds such as DBT and TP. Besides, the confined effect of pore for Cu(I)–Y also plays an important role in stabilizing Cu(I) sites in the micropores. This facile fabrication strategy combined with the size and confined effect of micropore for Cu(I)-zeolite adsorbent provides a new way for the composite of porous materials with various active sites.
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•Part of Cu(Ⅱ) ions in pores of zeolite Y are reduced to Cu(Ⅰ) sites with the confined space of zeolite Y.•The Cu(I)–Y adsorbent possesses proper amount of Cu(I) active sites and appropriate pore size.•Cu(I)–Y adsorbent exhibits large breakthrough adsorption sulfur capacity and superior regeneration.•The outstanding adsorption performance is attributed to the π-complexation interaction and the confined effect of micropores.
The initial signals governing sex determination vary widely among insects. Here we show that Armigeres subalbatus M factor (AsuMf), a male-specific duplication of an autosomal gene of the Drosophila ...behaviour/human splicing (DBHS) gene family, is the potential primary signal for sex determination in the human filariasis vector mosquito, Ar. subalbatus. Our results show that AsuMf satisfies two fundamental requirements of an M factor: male-specific expression and early embryonic expression. Ablations of AsuMf result in a shift from male- to female-specific splicing of doublesex and fruitless, leading to feminization of males both in morphology and general transcription profile. These data support the conclusion that AsuMf is essential for male development in Ar. subalbatus and reveal a male-determining factor that is derived from duplication and subsequent neofunctionalization of a member of the conserved DBHS family.
An effective surface-enhanced Raman scattering (SERS) method is presented for the rapid identification and drug sensitivity analysis of pathogens in blood. In a first step, polyethyleneimine-modified ...magnetic microspheres (Fe
3
O
4
@PEI) were used to enrich bacteria from blood samples. Next, the Fe
3
O
4
@PEI@bacteria complex was cultured on both ordinary and drug-sensitive plates. Lastly, the SERS spectra of single colonies were acquired in order to identify different pathogens and their resistant strains by comparison with established standardized bacterial SERS spectras and orthogonal partial least squares discriminant analysis (OPLS-DA) method.
Staphylococcus aureus
,
Acinetobacter baumannii
,
Pseudomonas aeruginosa
and their resistant strains were used to evaluate the performance of the SERS method. The results demonstrate that the method can accurately detect and identify all the tested sensitive and drug-resistant strains of bacteria, including 77 clinical blood infection samples. The method provides a way for rapid identification and susceptibility test of pathogens, and has great potential to replace currently used time-consuming methods.
Graphical abstract
Schematic presentation of a method for the rapid identification and drug sensitivity analysis of pathogens in blood. It is based on a combination of magnetic separation, SERS fingerprint analysis and orthogonal partial least squares discriminant analysis (OPLS-DA).
Harmless disposal of formaldehyde for hydrogen production is attractive in energy and environmental science. Herein, hydrogen production from formaldehyde steam reforming (FSR) using recyclable ...NiO/NaF was investigated, and the optimized 4 wt% catalyst exhibited 100% formaldehyde conversion, 104.9% H2 selectivity and excellent stability at 400 °C. The used catalysts can be easily recycled by water washing and pickling, and the activity of the regenerated catalyst is comparable to that of fresh one. We confirmed that FSR was a rapid surface reaction process, and the special contribution of NaF ensured the high activity of NiO/NaF with low specific surface areas. F ions in the carrier could activate the surface OH, which promoted adsorption and oxidation to reactants. Furthermore, the in situ DRIFTs study revealed that formate species (HCOO) was the key intermediate in formaldehyde steam reforming. Formaldehyde was first oxidized to HCOO and then decomposed into CO2 and H.
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•NiO/NaF is active and stable in formaldehyde steam reforming for H2 production.•The used NiO/NaF catalysts can be easily regenerated to the fresh level.•Formaldehyde steam reforming over NiO/NaF is a fast surface reaction.•Formate species is the key intermediate in formaldehyde steam reforming.
•NiO/NaF has universality for hydrogen production from OVOCs steam reforming.•OVOCs steam reforming over NiO/NaF is a rapid surface reaction process.•NaF can promote the efficient adsorption of OVOCs ...by NiO/NaF.•The local electric field generated by F- induces the weakening of the Ni-O bond.
Regenerable NiO/NaF catalysts break the limitation that catalyst with low specific surface area is difficult to obtain high catalytic activity. In this paper, we investigated the feasibility and universal applicability of hydrogen evolution from different oxygen-containing volatile organic compounds (OVOCs) such as methanol, formaldehyde, formic acid, ethanol, acetic acid, acetone and ethyl acetate steam reforming over NiO/NaF catalysts. The reaction processes and catalytic mechanism of OVOCs steam reforming by 4 wt%NiO/NaF catalyst were analyzed by FESEM, H2-TPR, in situ DRIFTS, XRD characterization and Density functional theory (DFT) calculation. The results showed that different OVOCs could achieve high-efficiency hydrogen production in steam reforming over 4 wt%NiO/NaF catalyst. The order of conversion easiness was formic acid > formaldehyde > methanol > acetic acid > ethanol > acetone > ethyl acetate. Single-carbon organics such as formic acid, formaldehyde and methanol, had H2 selectivity exceeding 100% at 350, 450 and 500 °C, respectively. The effective reforming temperature rose with the increasing of carbon contents of reactants. Further investigation confirmed that hydrogen production from different OVOCs steam reforming over 4 wt%NiO/NaF catalyst was a rapid surface reaction. And NaF played a key role, which not only promoted the adsorption of the catalyst to the reactants, but also generated local electric field induced by F- ion that weakened the Ni-O bond and reduced the activation energy. As a result, NiO/NaF had better low-temperature redox properties and hydrogen evolution performance than other nickel-based catalysts with big specific surface area.
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