TRPM4-Inspired Polymeric Nanochannels with Preferential Cation Transport for High-Efficiency Salinity-Gradient Energy Conversion.

Biological ion channels exhibit switchable cation transport with ultrahigh selectivity for efficient energy conversion, such as Ca2+-activated TRPM4 channels tuned by cation-π interactions, but achieving an analogous highly selective function is challenging in artificial nanochannels. Here, we design a TRPM4-inspired cation-selective nanochannel (CN) assembled by two poly(ether sulfone)s, respectively, with sulfonate acid and indole moieties, which act as cation-selective activators to manage Na+/Cl- selectivity via ionic and cation-π interactions. The cation selectivity of CNs can be activated by Na+, and thereby the Na+ transference number significantly improves from 0.720 to 0.982 (Na+/Cl- selectivity ratio from 2.6 to 54.6) under a 50-fold salinity gradient, surpassing the K+ transference number (0.886) and Li+ transference number (0.900). The TRPM4-inspired nanochannel membrane enabled a maximum output power density of 5.7 W m-2 for salinity-gradient power harvesting. Moreover, a record energy conversion efficiency of up to 46.5% is provided, superior to most nanochannel membranes (below 30%). This work proposes a novel strategy to biomimetic nanochannels for highly selective cation transport and high-efficiency salinity-gradient energy conversion.

A marine bacteria-inspired electrochemical regulation for continuous uranium extraction from seawater and salt lake brine.

Oceans and salt lakes contain vast amounts of uranium. Uranium recovery from natural water not only copes with radioactive pollution in water but also can sustain the fuel supply for nuclear power. The adsorption-assisted electrochemical processes offer a promising route for efficient uranium extraction. However, competitive hydrogen evolution greatly reduces the extraction capacity and the stability of electrode materials with electrocatalytic activity. In this study, we got inspiration from the biomineralisation of marine bacteria under high salinity and biomimetically regulated the electrochemical process to avoid the undesired deposition of metal hydroxides. The uranium uptake capacity can be increased by more than 20% without extra energy input. In natural seawater, the designed membrane electrode exhibits an impressive extraction capacity of 48.04 mg-U per g-COF within 21 days (2.29 mg-U per g-COF per day). Furthermore, in salt lake brine with much higher salinity, the membrane can extract as much uranium as 75.72 mg-U per g-COF after 32 days (2.37 mg-U per g-COF per day). This study provides a general basis for the performance optimisation of uranium capture electrodes, which is beneficial for sustainable access to nuclear energy sources from natural water systems.

Gradient Quasi-Solid Electrolyte Enables Selective and Fast Ion Transport for Robust Aqueous Zinc-Ion Batteries.

The quasi-solid electrolytes (QSEs) attract extensive attention due to their improved ion transport properties and high stability, which is synergistically based on tunable functional groups and confined solvent molecules among the polymetric networks. However, the trade-off effect between the polymer content and ionic conductivity exists in QSEs, limiting their rate performance. In this work, the epitaxial polymerization strategy is used to build the gradient hydrogel networks (GHNs) covalently fixed on zinc anode. Then, it is revealed that the asymmetric distribution of negative charges benefits GHNs with fast and selective ionic transport properties, realizing a higher Zn2+ transference number of 0.65 than that (0.52) for homogeneous hydrogel networks (HHNs) with the same polymer content. Meanwhile, the high-density networks formed at Zn/GHNs interface can efficiently immobilize free water molecules and homogenize the Zn2+ flux, greatly inhibiting the water-involved parasitic reactions and dendrite growth. Thus, the GHNs enable dendrite-free stripping/plating over 1000 h at 8 mA cm-2 and 1 mAh cm-2 in a Zn||Zn symmetric cell, as well as the evidently prolonged cycles in various full cells. This work will shed light on asymmetric engineering of ion transport channels in advanced quasi-solid battery systems to achieve high energy and safety.

Neuron-Inspired Nanofluidic Biosensors for Highly Sensitive and Selective Imidacloprid Detection.

Pesticides have caused concerns about food safety due to their residual effects in vegetables and fruits. Imidacloprid, as the frequently used neonicotinoid pesticide, could harm cardiovascular and respiratory function and cause reproductive toxicity in humans. Therefore, reliable methods for portable, selective, and rapid detection are desirable to develop. Herein, we report a neuron-inspired nanofluidic biosensor based on a tyrosine-modified artificial nanochannel for sensitively detecting imidacloprid. The functional tyrosine is modified on the outer surface of porous anodic aluminum oxide to rapidly capture imidacloprid through π-π interactions and hydrogen bonds. The integrated nanofluidic biosensor has a wide concentration range from 10-8 to 10-4 g/mL with an ultralow detection limit of 6.28 × 10-9 g/mL, which outperforms the state-of-the-art sensors. This work provides a new perspective on detecting imidacloprid residues as well as other hazardous pesticide residues in environmental and food samples.

Skeleton engineering of rigid covalent organic frameworks to alter the number of binding sites for improved radionuclide extraction.

Crystalline porous covalent frameworks (COFs) have been considered as a platform for uranium extraction from seawater and nuclear waste. However, the role of rigid skeleton and atomically precise structures of COFs is often ignored in the design of defined binding configuration. Here, a COF with an optimized relative position of two bidentate ligands realizes full potential in uranium extraction. Compared with the para-chelating groups, the optimized ortho-chelating groups with oriented adjacent phenolic hydroxyl groups on the rigid skeleton endow an additional uranyl binding site, thereby increasing the total number of binding sites up to 150%. Experimental and theoretical results indicate that the uranyl capture is greatly improved via the energetically favored multi-site configuration and the adsorption capacity reaches up to 640 mg g-1, which exceeds that of most reported COF-based adsorbents with chemical coordination mechanism in uranium aqueous solution. This ligand engineering strategy can efficiently advance the fundamental understanding of designing the sorbent systems for extraction and remediation technology.

Efficient Solar-osmotic Power Generation from Bioinspired Anti-fouling 2D WS2 Composite Membranes.

Nanofluidic reverse electrodialysis provides an attractive way to harvest osmotic energy. However, most attention was paid to monotonous membrane structure optimization to promote selective ion transport, while the role of external fields and relevant mechanisms are rarely explored. Here, we demonstrate a Kevlar-toughened tungsten disulfide (WS2 ) composite membrane with bioinspired serosa-mimetic structures as an efficient osmotic energy generator coupling light. As a result, the output power could be up to 16.43 W m-2 under irradiation, outperforming traditional two-dimensional (2D) membranes. Both the experiment and simulation uncover that the generated photothermal and photoelectronic effects could synergistically promote the confined ion transport process. In addition, this membrane also possesses great anti-fouling properties, endowing its practical application. This work paves new avenues for sustainable power generation by coupling solar energy.

Metabolic perturbations in human hepatocytes induced by bis (2-ethylhexyl)-2,3,4,5-tetrabromophthalate exposure: Insights from high-coverage quantitative metabolomics.

Bis (2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is an extensively used novel brominated flame retardant that is present ubiquitously in the environment and in biota. However, there is inadequate data on its potential hepatotoxicity to humans. In this study, high-coverage quantitative metabolomics based on 12C-/13C-dansylation labeling LC-MS was performed for the first time to assess the metabolic perturbations and underlying mechanisms of TBPH on human hepatocytes. HepG2 cells were exposed to TBPH at dosages of 0.1,1,10 µM for 24 or 72 h. Overall, 1887 and 1364 amine/phenol-containing metabolites were relatively quantified in cells and culture supernatant. Our results revealed that exposure to 0.1 µM TBPH showed little adverse effects, whereas exposure to 10 µM TBPH for 24 h enhanced intracellular protein catabolism and disrupted energy and lipid homeostasis-related pathways such as histidine metabolism, pantothenate and CoA biosynthesis, alanine, aspartate and glutamate metabolism. Nevertheless, most of these perturbations returned to the same levels as controls after 72 h of exposure. Additionally, prolonged TBPH exposure increased oxidative stress, as reflected by marked disturbances in taurine metabolism. This study sensitively revealed the dysregulations of intracellular and extracellular metabolome induced by TBPH, providing a comprehensive understanding of metabolic responses of cells to novel brominated flame retardants.

Distinct Bile Acid Profiles in Patients With Chronic Hepatitis B Virus Infection Reveal Metabolic Interplay Between Host, Virus and Gut Microbiome.

Hepatitis B virus (HBV) can hijack the host bile acids (BAs) metabolic pathway during infection in cell and animal models. Additionally, microbiome was known to play critical role in the enterohepatic cycle of BAs. However, the impact of HBV infection and associated gut microbiota on the BA metabolism in chronic hepatitis B (CHB) patients is unknown. This study aimed to unveil the distinct BA profiles in chronic HBV infection (CHB) patients with no or mild hepatic injury, and to explore the relationship between HBV, microbiome and BA metabolism with clinical implications. Methods: Serum BA profiles were compared between CHB patients with normal ALT (CHB-NALT, n = 92), with abnormal ALT (CHB-AALT, n = 34) and healthy controls (HCs, n = 28) using UPLC-MS measurement. Hepatic gene expression in CHB patients were explored using previously published transcriptomic data. Fecal microbiome was compared between 30 CHB-NALT and 30 HCs using 16S rRNA sequencing, and key microbial function was predicted by PICRUSt analysis. Results: Significant higher percentage of conjugated BAs and primary BAs was found in CHB patients even without apparent liver injury. Combinatory BA features can discriminate CHB patients and HCs with high accuracy (AUC = 0.838). Up-regulation of BA importer Na+ taurocholate co-transporting peptide (NTCP) and down-regulation of bile salt export pump (BSEP) was found in CHB-NALT patients. The microbial diversity and abundance of Lactobacillus, Clostridium, Bifidobacterium were lower in CHB-NALT patients compared to healthy controls. Suppressed microbial bile salt hydrolases (BSH), 7-alpha-hydroxysteroid dehydrogenase (hdhA) and 3-dehydro-bile acid Delta 4, 6-reductase (BaiN) activity were found in CHB-NALT patients. Conclusion: This study provides new insight into the BA metabolism influenced both by HBV infection and associated gut microbiome modulations, and may lead to novel strategy for clinical management for chronic HBV infection.

Impressive Proton Conductivities of Two Highly Stable Metal-Organic Frameworks Constructed by Substituted Imidazoledicarboxylates.

There is great interest in the promising applications of proton-conductive metal-organic frameworks (MOFs) in the field of electrochemistry. Thus, seeking more types of MOFs with high proton conductivity is of great importance. Herein, we designed and prepared two substituted imidazoledicarboxylate-based MOFs, {[Cd( p-TIPhH2IDC)2]·H2O} n [1; p-TIPhH3IDC = 2- p-(1 H-1,2,4-triazolyl)phenyl-1 H-4,5-imidazoledicarboxylic acid] and [Sr(DMPhH2IDC)2] n [2; DMPhH3IDC = 2-(3,4-dimethylphenyl)-1 H-imidazole-4,5-dicarboxylic acid], and fully explored their water-assisted proton conduction. The best conductivity for 1 of 1.24 × 10-4 S·cm-1 is higher than that of most previous conductive Cd-MOFs under similar conditions. 2 has the highest conductivity (0.92 × 10-3 S·cm-1) among the reported conductive Sr-MOFs. Via structural analysis, Ea values, water vapor adsorptions, and powder X-ray diffraction and scanning electron microscopy tests, reasonable proton pathways and conduction mechanisms were highlighted. It should be emphasized that the N-heterocyclic units (imidazole and triazole) and carboxyl and hydrogen-bonding networks in the frameworks all play crucial roles in the transmission of proton conductivity. Our research offers more choice for the preparation of desired proton-conductive materials.

Controlling Preanalytical Process in High-Coverage Quantitative Metabolomics: Spot-Sample Collection for Mouse Urine and Fecal Metabolome Profiling.

Compared to conventional MS and NMR techniques, high-performance chemical isotope labeling (CIL) LC-MS provides accurate relative quantification of many more metabolites in biological samples. However, to apply this technique for urine and fecal metabolomics studies of animal models, the entire workflow, including the preanalytical process, needs to be strictly controlled to avoid or minimize quantitative errors. In this study, we report our investigation of the effects of mouse urine and fecal sample collection methods on CIL LC-MS metabolome analysis. Metabolic-cage collection and spot-sample collection of urine and feces were compared in a mouse model of CCl4-induced liver disease. 13C-/12C-dansylation LC-MS was used for quantitative profiling of the amine-/phenol-submetabolome changes. A total of 5026, 4963, 4238, and 4600 peak pairs or metabolites were detected from spot urine, spot feces, cage-collected urine, and cage-collected feces, respectively. It was found that samples collected using metabolic cages, widely used in low coverage metabolomics, could be contaminated with food as well as cross-specimen (urine in feces or feces in urine) to the extent that metabolomic comparison of different groups of mice could be seriously compromised in high-coverage metabolomics. In contrast, spot urine and spot feces could be collected without contamination and should be used in CIL LC-MS metabolomics.

Copper-Catalyzed Double Thiolation To Access Sulfur-Bridged Imidazopyridines with Isothiocyanate.

A copper(I)-catalyzed sulfur-bridged dimerization of imidazopyridines has been developed using isothiocyanate as the sulfur source. This method enables a switchable synthesis of bis(imidazo[1,2- a]pyridin-3-yl)sulfanes or bis(2-(imidazo[1,2- a]pyridin-2-yl)phenyl)sulfanes in the presence of 4-dimethylaminopyridine (DMAP) or K2CO3 when different imidazopyridines were employed. Under optimized conditions, a variety of sulfur-bridged imidazopyridines were obtained in good yields. Moreover, thiourea was proved to be the key intermediate under catalytic system A.

Three-dimensional ionic liquid functionalized magnetic graphene oxide nanocomposite for the magnetic dispersive solid phase extraction of 16 polycyclic aromatic hydrocarbons in vegetable oils.

In this paper, a novel three-dimensional ionic liquid functionalized magnetic graphene oxide nanocomposite (3D-IL@mGO) was prepared, and used as an effective adsorbent for the magnetic dispersive solid phase extraction (MSPE) of 16 polycyclic aromatic hydrocarbons (PAHs) in vegetable oil prior to gas chromatography-mass spectrometry (GC-MS). The properties of 3D-IL@mGO were characterized by scanning electron micrographs (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM). The 3D-IL@mGO, functionalized by ionic liquid, exhibited high adsorption toward PAHs. Compared to molecularly imprinted solid phase extraction (MISPE), the MSPE method based on 3D-IL@mGO had less solvent consumption and low cost, and was more efficent to light PAHs in quantitative analysis. Furthermore, the rapid and accurate GC-MS method coupled with 3D-IL@mGO MSPE procedure was successfully applied for the analysis of 16 PAHs in eleven vegetable oil samples from supermarket in Zhejiang Province. The results showed that the concentrations of BaP in 3 out of 11 samples were higher than the legal limit (2.0µg/kg, Commission Regulation 835/2011a), the sum of 8 heavy PAHs (BaA, CHR, BbF, BkF, BaP, IcP, DaA, BgP) in 11 samples was between 3.03µg/kg and 229.5µg/kg. Validation results on linearity, specificity, accuracy, precision and stability, as well as on application to the analysis of PAHs in oil samples demonstrated the applicability to food safety risk monitoring in China.

[Determination of 16 polycyclic aromatic hydrocarbons in edible oils by gas chromatography-mass spectrometry combined with molecularly imprinted solid phase extraction].

OBJECTIVE: To establish a method for determination of 16 polycyclic aromatic hydrocarbons( PAHs) in edible oils by gas chromatography-mass spectrometry( GC/MS) combined with molecularly imprinted solid phase extraction( MISPE-GC/MS). METHODS: Oil samples were diluted with n-hexane, purified by SPE cartridges based on molecularly imprinted polymer. The cartridges were washed by n-hexane to remove impurities, then eluted with dichloromethane. After being concentrated to a volume of 200µL, the analytes were separated by capillary column( 30 m×0. 25 mm×0. 25 µm) and analyzed by GC/MS with selected ion monitoring( SIM) mode. Isotope internal standard method was adopted for quantification. RESULTS: The 16 kinds of PAHs showed good linearity in the range of 2-20 µg/L( r > 0. 998). The detection limits ranged from 0. 1 to0. 6 µg/kg. The recoveries of spiked samples at the level of 2 µg/kg and 10 µg/kg were in the range of 75. 5%-125. 2%( n = 6), the relative standard deviations( RSD) were all less than 15%. CONCLUSION: The proposed method is selective, fast, and presentsexcellent purification effect as well as high sensitivity, which makes it capable for rapid determination of 16 PAHs in edible oils with satisfactory accuracy.

[Determination of chlorfenapyr and indoxacarb in tea by gas chromatography-mass spectrometry with solid phase extraction].

OBJECTIVE: To establish a method for simultaneous determination of chlorfenapyr and indoxacarb in tea by gas chromatography-mass spectrometry. METHODS: The tea samples were homogenized and extracted with acetonitrile. Extracts obtained through centrifugation were cleaned up by CARB / NH2 cartridges, and further purified with SLH cartridges. After separated by DB-5MS capillary column( 30 m × 0. 25 mm × 0. 25µm), the analytes were measured by gas chromatography-mass spectrometry in selective ion monitoring( SIM) mode and quantified by external standard method. RESULTS: The linear range was 0. 10- 10 µg / m L for both of the two pesticides. The detection limits of chlorfenapyr and indoxacarb in tea samples were 0. 01 and 0. 008 mg / kg, and the quantitation limits were 0. 03 and 0. 025 mg / kg, respectively. The recoveries were from75. 6% to 92. 7%, and the relative standarddeviations( RSDs) were 3. 6%- 11. 4%( n =6). CONCLUSION: The proposed method has good purification effect and high accuracy, which is capable for simultaneously detecting the chlorfenapyr and indoxacarb in tea samples.

Silver nanoparticle gated, mesoporous silica coated gold nanorods (AuNR@MS@AgNPs): low premature release and multifunctional cancer theranostic platform.

Multifunctional nanoparticles integrated with an imaging module and therapeutic drugs are promising candidates for future cancer diagnosis and therapy. Mesoporous silica coated gold nanorods (AuNR@MS) have emerged as a novel multifunctional cancer theranostic platform combining the large specific surface area of mesoporous silica, which guarantees a high drug payload, and the photothermal modality of AuNRs. However, premature release and side effects of exogenous stimulus still hinder the further application of AuNR@MS. To address these issues, herein, we proposed a glutathione (GSH)-responsive multifunctional AuNR@MS nanocarrier with in situ formed silver nanoparticles (AgNPs) as the capping agent. The inner AuNR core functions as a hyperthermia agent, while the outer mesoporous silica shell exhibits the potential to allow a high drug payload, thus posing itself as an effective drug carrier. With the incorporation of targeting aptamers, the constructed nanocarriers show drug release in accordance with an intracellular GSH level with maximum drug release into tumors and minimum systemic release in the blood. Meanwhile, the photothermal effect of the AuNRs upon application to near-infrared (NIR) light led to a rapid rise in the local temperature, resulting in an enhanced cell cytotoxicity. Such a versatile theranostic system as AuNR@MS@AgNPs is expected to have a wide biomedical application and may be particularly useful for cancer therapy.

A family of ductile intermetallic compounds.

Stoichiometric intermetallic compounds have always been touted for their attractive chemical, physical, electrical, magnetic and mechanical properties, but few practical uses have materialized because they are brittle at room temperature. Here we report on a large family of fully ordered, stoichiometric binary rare-earth intermetallic compounds with high ductility at room temperature. Although conventional wisdom calls for special conditions, such as non-stoichiometry, metastable disorder or doping to achieve some ductility in intermetallic compounds at room temperature, none of these is required in these unique B2 rare-earth compounds. Ab initio calculations of YAg, YCu and NiAl crystal defect energies support the observed deformation modes of these intermetallics.