Copper-coordinated cellulose ion conductors for solid-state batteries.

Although solid-state lithium (Li)-metal batteries promise both high energy density and safety, existing solid ion conductors fail to satisfy the rigorous requirements of battery operations. Inorganic ion conductors allow fast ion transport, but their rigid and brittle nature prevents good interfacial contact with electrodes. Conversely, polymer ion conductors that are Li-metal-stable usually provide better interfacial compatibility and mechanical tolerance, but typically suffer from inferior ionic conductivity owing to the coupling of the ion transport with the motion of the polymer chains1-3. Here we report a general strategy for achieving high-performance solid polymer ion conductors by engineering of molecular channels. Through the coordination of copper ions (Cu2+) with one-dimensional cellulose nanofibrils, we show that the opening of molecular channels within the normally ion-insulating cellulose enables rapid transport of Li+ ions along the polymer chains. In addition to high Li+ conductivity (1.5 × 10-3 siemens per centimetre at room temperature along the molecular chain direction), the Cu2+-coordinated cellulose ion conductor also exhibits a high transference number (0.78, compared with 0.2-0.5 in other polymers2) and a wide window of electrochemical stability (0-4.5 volts) that can accommodate both the Li-metal anode and high-voltage cathodes. This one-dimensional ion conductor also allows ion percolation in thick LiFePO4 solid-state cathodes for application in batteries with a high energy density. Furthermore, we have verified the universality of this molecular-channel engineering approach with other polymers and cations, achieving similarly high conductivities, with implications that could go beyond safe, high-performance solid-state batteries.

Diatom Frustules Decorated with Co Nanoparticles for the Advanced Anode of Li-Ion Batteries.

Silica is regarded as a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity. However, large volume variation and poor electrical conductivity are limiting factors for the development of SiO2 anode materials. To solve this problem, combining SiO2 with a conductive phase and designing hollow porous structures are effective ways. In this work, The Co(II)-EDTA chelate on the surface of diatom biosilica (DBS) frustules and obtained DBS@C-Co composites decorated with Co nanoparticles by calcination without a reducing atmosphere is first precipitated. The unique three-dimensional structure of diatom frustules provides enough space for the volume change of silica during lithiation/delithiation. Co nanoparticles effectively improve the electrical conductivity and electrochemical activity of silica. Through the synergistic effect of the hollow porous structure, carbon layer and Co nanoparticles, the DBS@C-Co-60 composite delivers a high reversible capacity of >620 mAh g-1 at 100 mA g-1 after 270 cycles. This study provides a new method for the synthesis of metal/silica composites and an opportunity for the development of natural resources as advanced active materials for LIBs.

Cloning and identification of a new repressor of 3,17ß-Hydroxysteroid dehydrogenase of Comamonas testosteroni.

BACKGROUND: 3,17ß-hydroxysteroid dehydrogenase (3,17ß-HSD) is a key enzyme in the metabolic pathway for steroid compounds catabolism in Comamonas testosteroni. Tetracycline repressor (TetR) family, repressors existing in most microorganisms, may play key roles in regulating the expression of 3,17ß-HSD. Previous reports showed that three tetR genes are located in the contig58 of C. testosteroni ATCC 11996 (GenBank: AHIL01000049.1), among which the first tetR gene encoded a potential repressor of 3,17ß-HSD by sensing environmental signals. However, whether the other proposed tetR genes act as repressors of 3,17ß-HSD are still unknown. METHODS AND RESULTS: In the present study, we cloned the second tetR gene and analyzed the regulatory mechanism of the protein on 3,17ß-HSD using electrophoretic mobility shift assay (EMSA), gold nanoparticles (AuNPs)-based assay, and loss-of-function analysis. The results showed that the second tetR gene was 660-bp, encoding a 26 kD protein, which could regulate the expression of 3,17ß-HSD gene via binding to the conserved consensus sequences located 1100-bp upstream of the 3,17ß-HSD gene. Furthermore, the mutant strain of C. testosteroni with the second tetR gene knocked-out mutant expresses good biological genetic stability, and the expression of 3,17ß-HSD in the mutant strain is slightly higher than that in the wild type under testosterone induction. CONCLUSIONS: The second tetR gene acts as a negative regulator in 3,17ß-HSD expression, and the mutant has potential application in bioremediation of steroids contaminated environment.

PP2Acα inhibits PFKFB2-induced glycolysis to promote termination of liver regeneration.

The mechanisms underlying the initiation and proliferation of liver regeneration (LR) has been extensively studied using the partial hepatectomy (PHx) model, while little is known about the termination of LR. PP2Acα (protein phosphatase 2 A catalytic subunit α isoform) is the catalytic subunit of protein phosphatase 2 A (PP2A), accounting for most of intracellular serine/threonine phosphatase activity. We have previously observed that termination of LR delayed in PP2Acα liver-specific knockout (LKO) mice after PHx. In our study, we used phospho explorer antibody array analysis to screen the potential phosphorylation targets of PP2Acα, and PP2Acα had a great influence on the hepatic phosphoproteomic signaling in the termination of LR after PHx. We then tested the phosphorylation changes and metabolic function of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-2 (PFKFB2), an isoform of the key glycolytic enzyme PFKFB, which was significantly regulated by PP2Acα knockout. PP2Acα knockout enhanced glycolysis in vivo and in vitro, while adenoviral-mediated RNAi of PFKFB2 reversed the extension of postoperative liver regeneration in KO mice along with the downregulation of glycolysis. Therefore, we demonstrated that PP2Acα liver-specific knockout regulated the hepatocytes glycolysis via activating PFKFB2, thus enhancing liver regeneration during the termination stage.

A fast and simple headspace gas chromatographic technique for quantitatively analyzing urea in human urine.

A fast and convenient headspace gas chromatographic (HS-GC) approach was described for the estimation of urea in human urine. The HS-GC could detect the generated carbon dioxide derived from the urease-catalyzed hydrolysis of urea. It was found that the hydrolysis of urea catalyzed by urease was completed within 40 min at 35 °C. The results proved the great accuracy (relative errors ≤ 8.48%) and precision (RSD ≤ 2.66%) of the HS-GC approach. Moreover, the recoveries ranged from 97.9% to 101.5%. The new approach is rapid and automated, which provides a new way to routinely analyze urea in urine for the control of metabolic disease.

Simple and accurate method for determining dissolved inorganic carbon in environmental water by reaction headspace gas chromatography.

We investigate a simple and accurate method for quantitatively analyzing dissolved inorganic carbon in environmental water by reaction headspace gas chromatography. The neutralization reaction between the inorganic carbon species (i.e. bicarbonate ions and carbonate ions) in environmental water and hydrochloric acid is carried out in a sealed headspace vial, and the carbon dioxide formed from the neutralization reaction, the self-decomposition of carbonic acid, and dissolved carbon dioxide in environmental water is then analyzed by headspace gas chromatography. The data show that the headspace gas chromatography method has good precision (relative standard deviation ≤ 1.63%) and accuracy (relative differences ≤ 5.81% compared with the coulometric titration technique). The headspace gas chromatography method is simple, reliable, and can be well applied in the dissolved inorganic carbon detection in environmental water.

Measurement of water absorption capacity in wheat flour by a headspace gas chromatographic technique.

The purpose of this work is to introduce a new method for quantitatively analyzing water absorption capacity in wheat flour by a headspace gas chromatographic technique. This headspace gas chromatographic technique was based on measuring the water vapor released from a series of wheat flour samples with different contents of water addition. According to the different trends between the vapor and wheat flour phase before and after the water absorption capacity in wheat flour, a turning point (corresponding to water absorption capacity in wheat flour) can be obtained by fitting the data of the water gas chromatography peak area from different wheat flour samples. The data showed that the phase equilibrium in the vial can be achieved in 25 min at desired temperature (35°C). The relative standard deviation of the reaction headspace gas chromatographic technique in water absorption capacity determination was within 3.48%, the relative differences has been determined by comparing the water absorption capacity obtained from this new analytical technique with the data from the reference technique (i.e., the filtration method), which are less than 8.92%. The new headspace gas chromatographic method is automated, accurate and be a reliable tool for quantifying water absorption capacity in wheat flour in both laboratory research and mill applications.

Utilizing two detectors in the measurement of trichloroacetic acid in human urine by reaction headspace gas chromatography.

A reaction headspace gas chromatography (HS-GC) technique was investigated for quantitatively analyzing trichloroacetic acid in human urine. This method is based on the decomposition reaction of trichloroacetic acid under high-temperature conditions. The carbon dioxide and chloroform formed from the decomposition reaction can be respectively detected by the thermal conductivity detection HS-GC and flame ionization detection HS-GC. The reaction can be completed in 60 min at 90°C. This method was used to quantify 25 different human urine samples, which had a range of trichloroacetic acid from 0.52 to 3.47 mg/L. It also utilized two different detectors, the thermal conductivity detector and the flame ionization detector. The present reaction HS-GC method is accurate, reliable and well suitable for batch detection of trichloroacetic acid in human urine.

Efficient quantification of water content in edible oils by headspace gas chromatography with vapour phase calibration.

BACKGROUND: An automated and accurate headspace gas chromatographic (HS-GC) technique was investigated for rapidly quantifying water content in edible oils. In this method, multiple headspace extraction (MHE) procedures were used to analyse the integrated water content from the edible oil sample. A simple vapour phase calibration technique with an external vapour standard was used to calibrate both the water content in the gas phase and the total weight of water in edible oil sample. After that the water in edible oils can be quantified. RESULTS: The data showed that the relative standard deviation of the present HS-GC method in the precision test was less than 1.13%, the relative differences between the new method and a reference method (i.e. the oven-drying method) were no more than 1.62%. CONCLUSION: The present HS-GC method is automated, accurate, efficient, and can be a reliable tool for quantifying water content in edible oil related products and research. © 2017 Society of Chemical Industry.

Quantitative analysis of total starch content in wheat flour by reaction headspace gas chromatography.

This paper proposed a new reaction headspace gas chromatographic (HS-GC) method for efficiently quantifying the total starch content in wheat flours. A certain weight of wheat flour was oxidized by potassium dichromate in an acidic condition in a sealed headspace vial. The results show that the starch in wheat flour can be completely transferred to carbon dioxide at the given conditions (at 100 °C for 40 min) and the total starch content in wheat flour sample can be indirectly quantified by detecting the CO2 formed from the oxidation reaction. The data showed that the relative standard deviation of the reaction HS-GC method in the precision test was less than 3.06%, and the relative differences between the new method and the reference method (titration method) were no more than 8.90%. The new reaction HS-GC method is automated, accurate, and can be a reliable tool for determining the total starch content in wheat flours in both laboratory and industrial applications. Graphical abstract The total starch content in wheat flour can be indirectly quantified by the GC detection of the CO2 formed from the oxidation reaction between wheat flour and potassium dichromate in an acidic condition.

Method for improving accuracy in full evaporation headspace analysis.

We report a new headspace analytical method in which multiple headspace extraction is incorporated with the full evaporation technique. The pressure uncertainty caused by the solid content change in the samples has a great impact to the measurement accuracy in the conventional full evaporation headspace analysis. The results (using ethanol solution as the model sample) showed that the present technique is effective to minimize such a problem. The proposed full evaporation multiple headspace extraction analysis technique is also automated and practical, and which could greatly broaden the applications of the full-evaporation-based headspace analysis.

Quantification of anhydride groups in anhydride-based epoxy hardeners by reaction headspace gas chromatography.

We demonstrate a reaction headspace gas chromatographic method for quantifying anhydride groups in anhydride-based epoxy hardeners. In this method, the conversion process of anhydride groups can be realized by two steps. In the first step, anhydride groups in anhydride-based epoxy hardeners completely reacted with water to form carboxyl groups. In the second step, the carboxyl groups reacted with sodium bicarbonate solution in a closed sample vial. After the complete reaction between the carboxyl groups and sodium bicarbonate, the CO2 formed from this reaction was then measured by headspace gas chromatography. The data showed that the reaction in the closed headspace vial can be completed in 15 min at 55°C, the relative standard deviation of the reaction headspace gas chromatography method in the precision test was less than 3.94%, the relative differences between the new method and a reference method were no more than 9.38%. The present reaction method is automated, efficient and can be a reliable tool for quantifying the anhydride groups in anhydride-based epoxy hardeners and related research.

Measurement of permanganate index in environmental water via indirect phase-conversion strategy.

In this work, we proposed an indirect phase-conversion strategy to construct a new approach for accurately and efficiently determining the permanganate index in water samples via headspace GC measurement. After the reducible substances in water reacted with excess potassium permanganate, the remaining potassium permanganate underwent a reaction with sodium oxalate under acidic conditions. The carbon dioxide generated from the gas-evolving reaction was then analyzed by headspace GC. Our findings showed that this new approach boasts high precision (relative standard deviation ≤ 2.18%) and accuracy for permanganate index analysis, thus validating the effectiveness of this new method in analyzing permanganate index. The introduction of the indirect phase-conversion strategy in this study is expected to set a precedent for further advancements in methodologies designed to indirectly evaluate substances capable of undergoing gas-producing reactions.

Establishing a new methodology for determining the water absorbability of cellulose-derived materials via a vapor-monitoring headspace strategy.

In this research, for the first time, we introduce a vapor-monitoring headspace strategy to establish a new methodology for determining the water absorbability of cellulose-derived materials. The method involves detecting the water in the gas phase from various cellulose-derived materials after achieving the equilibrium state. By utilizing the headspace technique to monitor the change in water vapor pressure from bound water to free water, a change point indicating the water absorbability can be identified through fitting procedures. The study showed that the newly-established method possesses high precision (relative standard deviation ≤2.92%) and accuracy (relative differences ≤5.74%) for water absorbability analysis. The present method emerges as a facile and reliable tool for measuring water absorbability, and the introduction of the vapor-monitoring headspace strategy is anticipated to inspire the development of a new type of analytical method.

Quantifying sodium hypochlorite content in hypochlorite-based disinfectants via phase-conversion headspace technique.

In this work, a novel and efficient approach for sodium hypochlorite analysis is proposed via phase-conversion headspace technique, which is based on the gas chromatography (GC) detection of generated carbon dioxide (CO2) from the redox reaction of sodium hypochlorite with sodium oxalate. The data obtained by the proposed method suggest the high detecting precision and accuracy. In addition, the method has low detection limits (limit of quantification (LOQ) = 0.24 µg/mL), and the recoveries of added standard ranged from 98.33 to 101.27 %. The proposed phase-conversion headspace technique is efficient and automated, thereby offering an efficient strategy for highly efficient analysis of sodium hypochlorite and related products.

Molecular-caged metal-organic frameworks for energy management.

Metal-organic frameworks (MOFs) hold great promise for diverse applications when combined with polymers. However, a persistent challenge lies in the susceptibility of exposed MOF pores to molecule and polymer penetration, compromising the porosity and overall performance. Here, we design a molecular-caged MOF (MC-MOF) to achieve contracted window without sacrificing the MOF porosity by torsional conjugated ligands. These molecular cages effectively shield against the undesired molecule penetration during polymerization, thereby preserving the pristine porosity of MC-MOF and providing outstanding light and thermal management to the composites. The polymer containing 0.5 wt % MC-MOF achieves an 83% transmittance and an exceptional haze of 93% at 550 nanometers, coupled with remarkable thermal insulation. These MC-MOF/polymer composites offer the potential for more uniform daylighting and reduced energy consumption in sustainable buildings when compared to traditional glass materials. This work delivers a general method to uphold MOF porosity in polymers through molecular cage design, advancing MOF-polymer applications in energy and sustainability.

Design of Imide Oligomer-Mediated MOF Clusters for Solar Cell Encapsulation Systems by Interface Fusion Strategy.

Dielectric encapsulation materials are promising for solar cell areas, but the unsatisfactory light-management capability and relatively poor dielectric properties restrict their further applications in photovoltaic and microelectronic devices. Herein, an interface fusion strategy to engineer the interface of MOF (UiO-66-NH2 ) with anhydride terminated imide oligomer (6FDA-TFMB) is designed and a novel MOF cluster (UFT) with enhanced forward scattering and robust porosity is prepared. UFT is applied as an optical and dielectric modifier for bisphenol A epoxy resin (DGEBA), and UFT epoxy composites with high transmittance (>80%), tunable haze (45-58%) and excellent dielectric properties can be prepared at low UFT contents (0.5-1 wt%), which delivers an optimal design for dielectric encapsulation systems with efficient light management in solar cells. Additionally, UFT epoxy composites also show excellent UV blocking, and hydrophobic, thermal and mechanical properties. This work provides a template for the synthesis of covalent bond-mediated nanofillers and for the modulation of haze and dielectric properties of dielectric encapsulation materials for energy systems, semiconductors, microelectronics, and more.

A critical review on adsorption and recovery of fluoride from wastewater by metal-based adsorbents.

Rapid industrialization is deteriorating water quality, and fluoride pollution in water is one of the most serious environmental pollution problems. Adsorption technology is an efficient and selective process for removing fluoride from aqueous solutions using adsorbents. Metal-based adsorbents synergize the advantages of fast adsorption, high adsorption capacity, and excellent selectivity to effectively remove fluoride from water bodies, promising to satisfy environmental sustainability requirements. This paper reviews the metal-based adsorbents: iron-based, aluminum-based, lanthanum-based, cerium-based, titanium-based, zirconium-based, and multi-metal composite adsorbents, primarily focusing on the adsorption conditions and fluoride removal capacities and discusses prospects and challenges in the synthesis and application of metal-based adsorbents. This paper aims to stimulate new thinking and innovation in developing the next generation of sustainable adsorbents.

Mind Bomb 1 Promotes Pancreatic Cancer Proliferation by Activating ß-Catenin Signaling.

Mind bomb 1 (MIB1), an E3 ligase, plays a vital role in chemo-resistance and cancer metastasis. According to The Cancer Genome Atlas (TCGA), MIB1 gene is preferentially amplified in pancreatic cancer. Copy number alterations in MIB1 gene are associated with worse survival. Gene Expression Omnibus (GEO) also showed that pancreatic cancer with high mRNA level of MIB1 tend to be more resistant to gemcitabine and higher mRNA levels of MIB1 are found in pancreatic tumors compared with adjacent normal tissues. MIB1 knockdown (KD) in Panc-1 and HPAF2 cell lines significantly inhibit proliferation and colony formation of pancreatic cancer. The gene set enrichment analysis (GSEA) has also showed that ß-catenin is the downstream of MIB1. Western blot analysis showed that total and active ß-catenin levels are decreased in MIB1 KD cells. ß-catenin inhibitor also inhibits proliferation of Panc-1 and HPAF2 cells. We in this study implanted HPAF2 scramble and MIB1 KD cells orthotopically in athymic nude mice. Gemcitabine was used to treat the mice. Results revealed that after MIB1 KD HPAF2 cells were more sensitive to gemcitabine. In conclusion, we demonstrated that MIB1 promotes pancreatic cancer proliferation through activating ß-catenin signaling. MIB1 may thus be a therapeutic target in pancreatic cancer therapy.