Search

Reducing the oil-water interfacial tension (IFT) to ultra-low is believed the primary mechanism for surfactant-based enhanced oil recovery (EOR) process. However, field trials have shown that low concentration surfactant flooding can also improve oil recovery without ultra-low IFT. To clarify the mechanism behind, the currently-used surfactant, naphthenic arylsulfonate (NAS), was used to unravel its function during surfactant flooding from the horizon of micron- and nano-scale. The solubilization capacity of NAS micelle to petroleum fractions was evaluated through light absorbance strategy, small-angle neutron scattering, dynamic light scattering and transmission electron microscopy. It was found that micellar solubilization plays a significant role during the surfactant flooding. In-situ emulsification was visualized in microfluidics with three types of microchips, respectively. A series of displacement tests were carried out with NAS solution pumping into oil-saturated chip. The results show that in-situ emulsification improve oil recovery mainly through blocking and entrainment effects. Results from this work aid in understanding the interaction between surfactant solution and petroleum fractions at low surfactant concentration, which is helpful for design surfactant-based displacing system for EOR process.

Design and synthesis of noble-metal-free bifunctional catalysts for efficient and robust electrochemical water splitting are of significant importance in developing clean and renewable energy sources for sustainable energy consumption. Herein, a simple three-step strategy is reported to construct cobalt-iron nitride/alloy nanosheets on nickel foam (CoFe-NA/NF) as a bifunctional catalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The electrocatalyst with optimized composition (CoFe-NA2/NF) can achieve ultralow overpotentials of 73 mV and 250 mV for HER and OER, respectively, at a current density of 10 mA cm−2 in 1 M KOH. Notably, the electrolyzer based on this electrocatalyst is able to boost the overall water splitting with a cell voltage of 1.564 V to deliver 10 mA cm−2 for at least 50 h without obvious performance decay. Furthermore, our experiment and theoretical calculation demonstrate that the combination of cobalt-iron nitride and alloy can have low hydrogen adsorption energy and facilitate water dissociation during HER. In addition, the surface reconstruction introduces metal oxyhydroxides to optimize the OER process. Our work may pave a new pathway to design bifunctional catalysts for overall water splitting.

Posterior capsular opacification (PCO) is the main postoperative complication after intraocular lens (IOL) implantation in cataract surgery, because of the proliferation of the residual lens epithelial cells (LECs) in the lens capsule. Drug-eluting IOLs, aimed to develop an in situ drug delivery device, are the promising concept in recent years. As IOLs are optical devices other than implants, the feasibility and applicability remain a challenge for drug-eluting coatings. In this investigation, a centrifugally concentric ring-patterned drug-loaded poly(lactide-co-glycolic acid) (PLGA) coating was designed and fabricated by the spin coating technique. The concentric ring-patterned morphologies and the drug loading and release properties were carefully investigated, and the spin coating parameters were optimized. A concentric annular coating with a thin center and thick periphery was obtained, which was particularly suitable for the surface modification of IOLs, as the visual pathway of the intraocular light transmission greatly requires good light transmittance of the IOLs. IOLs with the immunosuppressant cyclosporin A (CsA)-loaded coating (CsA @ PLGA) modification were then fabricated for PCO prevention. The in vitro LECs culture results showed that the CsA @ PLGA coating-modified IOLs significantly inhibited cell proliferation and induced cell death. Western blot analysis showed that the efficient cell inhibition behavior of CsA was due to the autophagy-mediated cell death pathway. The in vivo intraocular implantation results confirmed the desired PCO inhibition effect. Thus, the centrifugally concentric ring-patterned drug-loaded PLGA coating obtained by the spin coating technique provides a simple yet effective alternative of IOL modification for PCO prevention. Statement of Significance • Concentric ring-patterned polymer coating, specifically for drug-eluting IOL fabrication, was developed by the spin coating technique. • The immunosuppressant CsA inhibited LEC proliferation through the autophagy-mediated cell death pathway. • Concentric ring-patterned CsA-eluting IOLs exhibited reliable in vivo PCO prevention. • The drug-eluting IOLs fabricated by the simple and economical spin coating technique have a great potential in clinical translation.

A series of tetraphenylporphyrin-based thermotropic liquid crystals containing oligo(dimethylsiloxane) were synthesized. These disc-coil hybrids form ordered nanostructures with periodic sizes on the sub-5 nm scale, including oblique columnar, lamellar, and hexagonal columnar phases. Films with sub-5 nm line patterns and homeotropically aligned columnar structures can be obtained by substrate-induced self-assembly.

Compared with the traditional suspension fermentation, immobilised biofilm fermentation has advantages of strong resistance, high yield and continuous fermentation and is conducive to improving the industrial fermentation methods. The formation of a biofilm on correct supports is critical to immobilised fermentation. In this study, Pichia pastoris was used to understand and control the modification of surface properties of supports and cells. Following deletion of gene PAS_chr2-1_0773, in P. pastoris △0773, the cell-surface negative charge density decreased and hydrophobicity improved, which was conducive to adhesion. Therefore, according to the changing trend of cell surface properties, cotton fibre was used with succinic anhydride (SA) to modify the carrier for changing the surface properties for efficient conduction of immobilised fermentation. In the fermentation process, the adhesion between the modified cotton fibre and yeast was better than that between an unmodified cotton fibre and yeast, and the additive amount increased by ∼25 %. The enzyme activity of the △0773-cotton-SA fermentation system reached 302.7 U/mL, which was 39.6 % higher than that of the original fermentation system. Therefore, this study provides a guide for significant improvement of immobilised fermentation of fungi.

Background Tin oxide (SnO2) has attracted numerous interests as anode for lithium ion batteries (LIBs) owing to its high theoretical specific capacity of 782 mAh/g. But the poor conductivity and rapid capacity fading during the electrochemical cycling due to the huge volume variation limit its practical application. Methods Ultra-fine SnO2 nanoparticles were anchored onto polypyrrole nanotubes (T-PPy) as clusters via a facile hydro-thermal reaction. Their ultra-fine size is beneficial to the volumetric change alleviation, while the clusters would increase the loading amount of the active materials and maintain a high specific surface area. Significant findings The hierarchically porous (T-PPy)@SnO2 hybrid were obtained with high SnO2 content around 70% and large specific surface area of 128.82 m2/g. They could deliver a high specific capacity of 605.0 mAh/g after 300 cycles at a current density of 1.0 C (782 mA/g), presenting an excellent cycling performance, and a discharge capacity of 422.2 mAh/g at 2.0 C, exhibiting a good rate capability.

Hydrogel-based wearable sensors have flourished as encouraging candidates for human mechanosensation due to their controllable conductivity and tailorable mechanical performances. However, it is st...

Liquid electrolytes used in lithium-ion batteries suffer from leakage, flammability, and lithium dendrites, making polymer electrolyte a potential alternative. Herein, a series of ABA triblock copolymers (ABA-x) containing a mesogen-jacketed liquid crystalline polymer (MJLCP) with a polynorbornene backbone as segment A and a second polynorbornene-based polymer having poly(ethylene oxide) (PEO) side chains as segment B were synthesized through tandem ring-opening metathesis polymerizations. The block copolymers can self-assemble into ordered morphologies at 200 °C. After doping of lithium salts and ionic liquid (IL), ABA-x self-assembles into cylindrical structures. The MJLCP segments with a high glass transition temperature and a stable liquid crystalline phase serve as physical crosslinking points, which significantly improve the mechanical performance of the polymer electrolytes. The ionic conductivity of ABA-x/lithium salt/IL is as high as 10−3 S·cm−1 at ambient temperature owing to the high IL uptake and the continuous phase of conducting PEO domains. The relationship between ionic conductivity and temperature fits the Vogel-Tamman-Fulcher (VTF) equation. In addition, the electrolyte films are flame retardant owing to the addition of IL. The polymer electrolytes with good safety and high ambient-temperature ionic conductivity developed in this work are potentially useful in solid lithium-ion batteries.

Stimuli-responsive solids with adjustable photophysical properties are particularly attractive because they can be used as smart materials in anticounterfeiting, information storage, holographic imaging, and other fields. Herein, we report a unique nonporous coordination polymer, {[Ag(3,3'-dpe)](2,2'-Hbpdc)}n (1; 3,3'-dpe = 1,2-dipyridin-3-ylethene and 2,2'-H2bpdc = 2,2'-biphenyldicarboxylic acid), that can convert to an extremely photoreactive compound, 1·H2O·MeCN (MeCN = acetonitrile), through guest capture. Upon irradiation of sunlight, 1·H2O·MeCN can transform to {[Ag(3,3'-tpcb)0.5](2,2'-Hbpdc)(H2O)(MeCN)}n (2·H2O·MeCN; 3,3'-tpcb = 1,2,3,4-tetrapyridin-3-ylcyclobutane). 2·H2O·MeCN can lose its solvent molecules to form 2 and further return to 1 at high temperature. Accompanied by direct visualization based on multistep single-crystal-to-single-crystal conversions, the recyclable crystalline solid exhibits remarkable fluorescence changes, which makes it a supramolecular switch for application in multiple anticounterfeiting.

The development of an efficient hydrogen spillover (HS) catalyst achieves the stoichiometric chemoselective hydrogenation of NO3− and NO2− into N2 at room temperature, which is extremely challenging. Herein, we report a CuxPd1−x nanowire network (NWN) (x = 7, 5, or 3) with tunable hydrogen spillover rate of formic acid (FA) with polyvinylpyrrolidine imine (PVPI) modifying its surface. The presence of PVPI boosts the catalytic selectivity and activity of CuPd NWN for FA dehydrogenation and, more importantly, serves as a modem to tune the HS rate of FA and to stoichiometrically hydrogenate NO3− and NO2− to N2 at room temperature. The density functional theory (DFT) reveals that the CuPd (130 h−1) has a weaker HS rate than AgPd (390 h−1), but the CuPd (> 99%) has a higher utilization of HS than AgPd (31%). Our studies demonstrate a new approach of tuning the FA HS rate and maximizing the application for stoichiometric chemoselective hydrogenation reaction, which will be important for hydrogen generation and its applications.

Light serves as one of the major environmental signals that stimulates anthocyanin biosynthesis in higher plants. In this study, we demonstrate that AtGLK2, an Arabidopsis nuclear GARP transcription factor, plays a positive role in the regulation of anthocyanin biosynthesis. The disruption of AtGLK2 decreased the anthocyanin contents in Arabidopsis seedlings, whereas the overexpression of AtGLK2 resulted in significant enhancements to the accumulation of anthocyanin. Gene expression analysis demonstrated that the expression of late biosynthetic genes in the anthocyanin biosynthetic pathway was dramatically reduced in glk2 but elevated in AtGLK2-overexpressing seedlings. It was found that the disruption of AtHY5 decreased the expression of AtGLK2 and that AtGLK2 exhibited light-responsive expression patterns in an AtHY5-dependent manner. Further studies demonstrated that AtHY5-mediated light signaling is required for AtGLK2-regulated anthocyanin accumulation and photosynthetic development. Moreover, AtGLK2 and AtMYBL2 antagonistically regulate the expression of anthocyanin biosynthetic genes and the subsequent anthocyanin accumulation process. Taken together, our data reveal that AtGLK2 positively regulates anthocyanin biosynthesis through AtHY5-mediated light signaling in Arabidopsis.

To address overheating and electromagnetic interference of integrated electronics, the design of multi-functional materials with high out-of-plane thermal conductivity and excellent electromagnetic interference shielding effectiveness is desirable. In this contribution, an anisotropy graphene/multi-walled carbon nanotubes with 3D continuous network is fabricated by KOH induced hydrothermal reaction and subsequent graphitization at 2800 °C. When the graphene oxide to multi-walled carbon nanotubes ratio is 1:3, the balance between the decline of sp2 crystallite size in horizontal direction and the enhancement of turbostratic-stacking is achieved, which facilities the phonon transfer and electron transport. The optimal thermal conductivity of composites reaches up to 1.30 W m−1 K−1 at a low loading of 2.77 wt%, which is 465% higher than that of pure silicon rubber (0.23 W m−1 K−1). Meanwhile, the composite exhibits the maximum electric conductivity and electromagnetic interference shielding effectiveness of 42 dB in K-band. Moreover, it still retains the flexibility of matrix. This work paves the way of lightweight dual-function integrated materials.

The present work focused on the combustion chemistry in sooting transition process in iso-octane counterflow diffusion flames. A series of iso-octane flames ranging from sooting-free to heavy-sooting were investigated by stepwise increasing the oxygen concentration (XO) in the oxidizer stream. In particular an optical approach with two different algorithms based on the three wavelengths distribution of flame images captured by digital single lens reflex (DSLR) camera was proposed to identify the critical condition for the sooting transition process. The results showed that the sharp increase in signal ratio of red luminosity with simultaneously obvious decrease in signal rations of blue luminosity could be used as an effective indicator of sooting onset in flames. On-line gas chromatography (GC) measurements were used to investigate the flame chemistry and determine quantitative mole fraction profiles of stable and reactive species formed in the combustion process. Particular attention was given to the combustion chemistry changes caused by the occurrence of sooting transition. Numerical kinetic simulations were performed along with the comparisons with experimental results to obtain deep insights into the sooting transition process, with focus on benzene chemistry considering the critical role of benzene formation in the subsequent large aromatic species/soot formation process. In most cases, the trend observed in the experiments could be satisfactorily reproduced and explained by the models. For major species and C1–C4 species, it can be seen that the concentration increased with the increase of XO in sooting transition process. For the decomposition of fuel and the formation of benzene, the influence in sooting transition process was mainly reflected in the contributions of different pathways due to temperature effects. The impact of sooting transition on flame chemical structure was mainly reflected in the growth of PAHs. The increasing trend for the PAHs growth caused by the increase of oxygen concentration in the transition process was more and more obvious.

Atomically dispersed metals stabilized by nitrogen elements in carbon skeleton hold great promise as alternatives for Pt-based catalysts towards oxygen reduction reaction in proton exchange membrane fuel cells. However, their widespread commercial applications are limited by complicated synthetic procedures for mass production. Herein, we are proposing a simple, green mechanochemical approach to synthesize zeolitic imidazolate frameworks precursors for the production of atomically dispersed “Fe-N4” sites in holey carbon nanosheets on a large scale. The thin porous carbon nanosheets (PCNs) with atomically dispersed “Fe-N4” moieties can be prepared in hectogram scale by directly pyrolysis of salt-sealed Fe-based zeolitic imidazolate framework-8 (Fe-ZIF-8@NaCl) precursors. The PCNs possess large specific surface area, abundant lamellar edges and rich “Fe-N4” active sites, and show superior catalytic activity towards oxygen reduction reaction in an acid electrolyte. This work provides a promising approach to cost-effective production of atomically dispersed transition metal catalysts on large scale for practical applications.

Optical coherence tomography (OCT) is one of the most commonly used ophthalmic diagnostic techniques. Macular Edema (ME) is the swelling of the macular region in the eye. Segmentation of the fluid region in the retinal layer is an important step in detecting lesions. However, manual segmentation is often a time consuming and subjective process. In this paper, an improved U-Net segmentation method is proposed. In this method, the attention mechanism is introduced to automatically locate the fluid region, which avoids the problem of excessive calculation in multi-stage methods. At the same time, the use of dense skip connections which combines high-level and low-level features makes the segmentation results more precise. The loss function is a joint loss, including weighted binary cross entropy loss, dice loss, and regression loss, where regression loss is used to avoid the problem of merging multiple fluid regions into one. The experimental results show that the proposed method can adapt to the OCT scans acquired by various imaging scanning devices, and this method is more effective than other start-of-the-art fluid segmentation methods.

The high activity electrocatalysts with low cost are crucial for large-scale direct alcohol fuel cells (DAFCs) applications. In this study, the “self-doping-defects” mesoporous carbon (SDMC) as support of uniformly-dispersed Pd nanoparticles (Pd/SDMC) was prepared for high active electrooxidation by a simple route without additional surfactant and acid treatment. According to the mutually corroborated experimental and theoretical calculation results, our route can significantly increase the carbon defect, which is conducive to the anchoring and uniform distribution of Pd nanoparticles. Meanwhile, the uniquely and hierarchically mesoporous nanostructure of SDMC provides abundant pathways for mass transport in the electrooxidation reaction. Benefitting from the above advantages, Pd/SDMC exhibits superior activity than commercial Pd/C and previously reported carbon-based electrocatalysts. The mass activities and specific activities of Pd/SDMC toward ethanol oxidation reaction (EOR) are 3404.3 mA mg−1, 4.48 mA cm−2, respectively. The mass activities and specific activities of Pd/SDMC for ethylene glycol oxidation reaction (EGOR) are 4002 mA mg−1, 5.26 mA cm−2, respectively. We believe that the facile strategy to synthesis mesoporous carbon with “self-doping” defects would promote large-scale DAFCs applications in the future.

In this work, we report experimental characterizations of stimulated Brillouin scattering (SBS) in low-loss Ge25Sb10S65 (GeSbS) chalcogenide waveguides. A 7-cm-long spiral waveguide with a propagation loss as low as 0.2 dB/cm and a microring resonator with a high loaded quality factor of 1.34×106 are demonstrated. In addition, we use a high-resolution pump-probe measurement technique to investigate the SBS characteristics in the GeSbS waveguide. The measured Brillouin frequency shift and the intrinsic Brillouin linewidth are 7.443 GHz and 47.8 MHz, respectively. A Brillouin-gain coefficient of 338 m−1W−1 is obtained, which corresponds to an intrinsic Brillouin gain of 0.524×10-9 m/W, comparable to that of As2S3 chalcogenide. Moreover, a 17.6-dB probe gain is achieved with a continuous-wave pump of 200 mW, while nonlinear losses are not observed. The large Brillouin gain, together with the low linear propagation loss and the negligible nonlinear loss, make the GeSbS chalcogenide waveguides become a very promising arsenic-free integrated platform for on-chip Brillouin applications.

The Confinement effect is an effective strategy for enhancing the performance of catalysts during various reactions. We developed a strategy to encapsulating Palladium nanoparticles with a dopamine-derived N-doped multilayer carbon shell to catalyze the Heck reaction between iodobenzene and carbon–carbon double-bond compounds (styrene and methyl acrylate). The catalytic performances of Pd nanoparticles encapsulated within a N-doped carbon layer (Pd@N-C) and those attached to the external surface of such a layer (Pd/N-C) were evaluated and compared. Pd@N-C exhibited a lower reaction activation energy (78 kJ/mol) than that of Pd/N-C (106 kJ/mol). Thus, the activity of Pd@N-C during the Heck reaction between iodobenzene and methyl acrylate was approximately 20 times higher than that of Pd/N-C-200. The results of thermal filtration and recycling tests indicated that Pd@N-C showed a lower degree of leaching than that of Pd/N-C-200 owing to the spatial restriction effect of the cavity in the case of the former. Hence, the superior catalytic performance of Pd@N-C can be ascribed to the confinement of the Pd nanoparticles within the N-doped carbon layer. Finally, we used these catalysts to synthesize a range of para-substituted iodobenzene derivatives, thus demonstrating the potential of Pd-encapsulating catalysts for use in the Heck reaction on the technical scale.

Titanium nitride (TiN) decorated N-doped titania (N-TiO2) composite (TiN/N-TiO2) is fabricated via an in situ nitridation using a hydrothermally synthesized TiO2 and melamine (MA) as raw materials. After the optimization of the reaction condition, the resultant TiN/N-TiO2 composite delivers a hydrogen evolution activity of up to 703 μmol/h under the full spectrum irradiation of Xe-lamp, which is approximately 2.6 and 32.0 times more than that of TiO2 and TiN alone, respectively. To explore the underlying photocatalytic mechanism, the crystal phase, morphology, light absorption, energy band structure, element composition, and electrochemical behavior of the composite material are characterized and analyzed. The results indicate that the superior activity is mainly caused by the in situ formation of plasmonic TiN and N-TiO2 with intimate interface contact, which not only extends the spectral response range, but also accelerates the transfer and separation of the photoexcited hot charge carrier of TiN. The present study provides a fascinating approach to in situ forming nonmetallic plasmonic material/N-doped TiO2 composite photocatalysts for high-efficiency water splitting.

The development of atomically precise dinuclear heterogeneous catalysts is promising to achieve efficient catalytic performance and is also helpful to the atomic-level understanding on the synergy mechanism under reaction conditions. Here, we report a Ni2(dppm)2Cl3 dinuclear-cluster-derived strategy to a uniform atomically precise Ni2 site, consisting of two Ni1-N4 moieties shared with two nitrogen atoms, anchored on a N-doped carbon. By using operando synchrotron X-ray absorption spectroscopy, we identify the dynamically catalytic dinuclear Ni2 structure under electrochemical CO2 reduction reaction, revealing an oxygen-bridge adsorption on the Ni2-N6 site to form an O-Ni2-N6 structure with enhanced Ni-Ni interaction. Theoretical simulations demonstrate that the key O-Ni2-N6 structure can significantly lower the energy barrier for CO2 activation. As a result, the dinuclear Ni2 catalyst exhibits >94% Faradaic efficiency for efficient carbon monoxide production. This work provides bottom-up target synthesis approaches and evidences the identity of dinuclear sites active toward catalytic reactions.

Because of the great risk of spontaneous combustion of coal, new gel materials are used for fire prevention and firefighting in coal mines. In this study, sodium alginate (SA), polyacrylamide (CPAM), and carboxymethyl cellulose (CMC) were used as matrices to prepare three different types of fireproof gel: SA-Al3+/WG, CPAM-Al3+/WG, and CMC-Al3+/WG, respectively. Their thermal stabilities were analyzed using thermogravimetric analysis. The microstructures of these gels were observed using scanning electron microscopy, and their chemical bond breakages and combinations were analyzed using Fourier-transform infrared spectroscopy. The CMC-Al3+/WG hydrogel had the best water retention capacity, water absorption capacity, compressive strength, and inhibition characteristics according to the results of the water retention rate tests, swelling kinetics experiments, mechanics, and fire extinguishing experiments. It was proven that CMC-Al3+/WG gel is an ideal fire-extinguishing material.

Epigenetic manipulation of a deep-sea sediment-derived Spiromastix sp. fungus using suberoylanilide hydroxamic acid (SAHA) induction resulted in the activation of a terpene-related biosynthetic gene cluster, and nine new guaiane-type sesquiterpenes, spiromaterpenes A-I (1-9), were isolated. Their structures were determined using various spectroscopic techniques, in association with the modified Mosher's method, computed electronic circular dichroism (ECD) spectra, and chemical conversion for configurational assignments. Compounds 4-6 exhibited significant effects against the NO production on lipopolysaccharide (LPS)-induced microglia cells BV2, and the preliminary SAR analyses demonstrated that a 2(R),11-diol unit is favorable. The most active 5 abolished LPS-induced NF-κB translocation from the cytosol to the nucleus in BV-2 microglial cells, accompanied by the marked reduction of the transcription levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α dose-dependently in both LPS-induced BV-2 and BV-2 cells, as well as the protein and mRNA levels of iNOS and COX-2. This study complements the gap in knowledge regarding the anti-neuroinflammatory activity of guaiane-type sesquiterpenoids at the cellular level and suggests that 5 is promising for further optimization as a multifunctional agent for antineuroinflammation.

Molybdenum disulfide (MoS2) is intrinsically inert for the hydrogen evolution reaction (HER) in alkaline media due to its electronic structures. Herein, we tune the electronic structures of MoS2 by a combined strategy of post-N doping coupled with the synergistic effect of Ti3C2TX. The as-prepared N-doped MoS2/Ti3C2TX heterostructures show remarkable alkaline HER activity with an overpotential of 225 mV at 140 mA cm-2, which ranks the N-doped MoS2/Ti3C2TX heterostructures among the best MoS2/MXene-based electrocatalysts reported for alkaline HER. The first-principles calculations indicate that the N doping can enhance the activation of nearby S sites of MoS2/Ti3C2TX and thus promote the HER process. This strategy provides a promising way to develop high-efficiency MoS2/MXene heterostructure catalysts for alkaline HER.

We present the design, preparation, and performance optimization of strip waveguide in chalcogenide glass (ChG) for broadband supercontinuum (SC) generation. Ternary Ge-Sb-S systems possess large band-gap, high refractive index, and strong laser damage resistance. The characterization of strip waveguide in Ge-Sb-S glass for SC source generation with 1300 nm bandwidth is experimentally demonstrated. Sensing capability of the device is validated for optical absorption of β-phenylethylamine solutions near 1551 nm in various concentrations, revealing the repeatability and consistency of the generated SC spectrum in test. The advantages of high specificity detection scheme, scalable integration and ease of miniaturization might make the device a promising platform for biochemical monitoring.

Fermentation and chemical methods for industrial cytidine diphosphate choline (CDP-choline) catalytic production both suffer from several disadvantages such as relatively low efficiency and productivity. To overcome these problems, we applied the concept of synthetic biology to develop a new one-pot multi-enzyme system to produce CDP-choline from orotic acid. Enzymes from different sources were selected and optimized as building blocks of the system, and parameters such as oxygen supply were also optimized. This system shows a titer of 37.6 ± 1.1 mM and a reaction rate of 1.6 mM L-1 h-1, both increase 66 % from traditional processes. It also has an efficiency of energy of 25.4%, improves 2-folds. This new one-pot CDP-choline-producing system has a potential for industrial use, and the procedure to design one-pot multi-enzyme system can be applied to build other one-pot system producing energy-rich compounds.

In biomass pyrolysis engineering, it is important to develop an industrial catalyst with efficient activity, high selectivity, and a long working life. Dolomite-based porous ceramics were considered in this work. The influence of total corn flour content on the open porosity, compressive strength, and thermal conductivity of dolomite-based porous ceramics was investigated. In order to enhance the catalytic activity, dolomite-based porous ceramics were impregnated with an Al2(SO4)3 solution to load the Al2O3 catalyst. Catalytic fast pyrolysis experiments using corn stalk were conducted with the aforementioned catalyst. The bio-oil yield increased as the open porosity of the dolomite-based porous ceramics increased. The pyrolysis bio-oil yield decreased as the Al2(SO4)3 concentration increased. The phenol content in the bio-oil increased as the Al2O3 load increased. Aluminum oxide not only promoted the formation of phenols in the bio-oil, but it also promoted the conversion of phenols, e.g., 4-ethylphenol and 2, 6-dimethoxy-phenol. The results demonstrated that Al2O3 was beneficial for the formation of phenols during pyrolysis. The results detailing the preparation of Al2O3 loaded dolomite-based porous ceramics can provide a reference for large-scale biomass pyrolysis projects.

It still is a challenge to create a superior and easily coupled bifunctional electrocatalyst for water splitting impelled by a low voltage. In this work, the controlled growth of Co2P NAs on the surface of a MXene (Ti3C2Tx)-modified self-supporting electrode is demonstrated as a competent and reliable bifunctional electrocatalyst for efficient water splitting. The heterointerface in Co2P@Ti3C2Tx with an optimized adsorption free energy of H*, H2O, and better conductivity can give enhanced HER (hydrogen evolution reaction) activity, with a low overpotential (42 mV) at 10 mA cm-2. Additionally, the OER (oxygen evolution reaction) activity has also been similarly strengthened by the synergy of Co2P and MXene with an overpotential of 267 mV to arrive at 10 mA cm-2. Furthermore, the excellent bifunctional electrode (Co2P@Ti3C2Tx∥Co2P@Ti3C2Tx) exhibits efficient engineering water-splitting performance (1.46 V@10 mA cm-2) in alkaline solution. This simple design can propose a promising approach to exploit precious-metal-free catalysts for energy conversion.

Hydrogen evolution reaction (HER) is a critical process in electrocatalytic water splitting for hydrogen production. However, the development of low-cost electrocatalysts for highly efficient HER is still a huge challenge. Hence, we fabricate a multi-metal phosphide on Ni foam, FeCoNiNbxP, through a facile hydrothermal reaction followed by phosphorization. We find that Nb promotes the formation of metal phosphides, and the main phases of the catalysts with Nb are multiphase phosphides. Importantly, the Nb incorporation significantly improves the HER activity of FeCoNiP. We show that FeCoNiNb0.3P has the best HER activity, which only requires an overpotential of 78 mV to achieve a current density of 10 mA cm−2 in 1 M KOH, and demonstrates excellent stability under both constant potential and varied current densities. Our findings show that the multiple-metal compounds are beneficial to the improvement of catalytic activity and provide guidance on the design of novel catalysts for applications.

The miglitol intermediate, 6-(N-hydroxyethyl)-amino-6-deoxy-α-l-sorbofuranose (6NSL), is catalyzed from N-2-hydroxyethyl glucamine (NHEG) by resting cells of Gluconobacter oxydans. One of the key factors limiting 6NSL production was the availability of oxygen during both cell cultivation and biotransformation of NHEG to 6NSL. Based on G. oxydans/pBBR1-sldAB-pqqABCDE-tldD (G. oxydans/AB-PQQ), the Vitreoscilla hemoglobin (VHb) was heterologously expressed in G. oxydans to enhance oxygen transfer efficiency and improve 6NSL production. The recombinant G. oxydans/AB-PQQ-VHb displayed higher biomass and NHEG oxidation activity than the control stain. The transcription levels of respiratory chain-related enzyme genes in G. oxydans/AB-PQQ-VHb exhibited up-regulation, indicating that the presence of VHb promoted the respiration. The dissolved oxygen (DO) concentration for cell cultivation was optimized in a 5-L stirred bioreactor. At a DO concentration of 20%, the maximum volumetric oxidation activity of NHEG of G. oxydans/AB-PQQ-VHb in the stirred bioreactor reached 168.3 ± 3.2 U/L. Furthermore, the biotransformation of NHEG to 6NSL using G. oxydans/AB-PQQ-VHb was carried out under different oxygen tensions to investigate the effect of oxygen on 6NSL production. Finally, up to 87.5 ± 5.9 g/L 6NSL was accumulated in the reaction mixture within 16 h when the DO was controlled at 30%.

BACKGROUND Eltrombopag is an orally administered thrombopoietin receptor agonist linked to a heightened risk of treatment-related thromboembolism. Both venous and arterial thromboses have been documented in the medical literature. CASE SUMMARY In the absence of nephropathy, a 48-year-old patient receiving eltrombopag for immune thrombocytopenia (ITP) developed renal vein thrombosis and pulmonary embolism. The renal vein thrombus spontaneously resolved during subsequent anticoagulant treatment, restoring venous circulation. CONCLUSION A rapid upsurge in platelets, rather than their absolute number, may trigger thrombotic events in this setting. For patients at high thrombotic risk, individualized eltrombopag dosing and vigilance in platelet monitoring are perhaps needed during treatment of ITP.

Torrefaction pretreatment conducted at a low temperature is an important technique for refining the bio-oil and improving the production of some chemicals in the bio-oil (e.g. aromatic hydrocarbons). In this work, the effects of torrefaction temperature and catalysts on the yields of pyrolysis products and components distribution in the bio-oils were analyzed. The weak acid sites shifted to higher temperature as the HZSM-5 was modified by Mg2+ or Al3+. The catalytic pyrolysis from camphorwood was done at pyrolysis of 450 °C and torrefaction temperature of 200 °C. The catalysts remarkably influenced the yields of bio-oil and components distribution. The catalysts increased the production of phenols. The content of phenols in the resulting bio-oil exhibited the following trend: HZSM-5 < MgO-modified HZSM-5 < Al2O3-modified HZSM-5. In addition, the content of 2,6-dimethoxyphenol was the highest among all phenol components (5.58%). The production of aldehydes was remarkably improved by the Al2O3-modified HZSM-5, resulting in a maximum content of 8.21%. Thus the torrefaction temperature and catalysts would refine the bio-oil (such as the acid value decreased) and significantly improve the contents of components (such as D-allose, 2,6-dimethoxy-4-(2-propeny)-phenol, 1,2,4-trimethoxybenzene, and 2,6-dimethoxyphenol). The results provide a theoretical basis for the resource recovery of biomass.

Fermentation using Corynebacterium glutamicum is an important method for the industrial production of amino acids. However, conventional fermentation processes using C. glutamicum are susceptible to microbial contamination and therefore require equipment sterilization or antibiotic dosing. To establish a more robust fermentation process, l-lysine-producing C. glutamicum was engineered to efficiently utilize xenobiotic phosphite (Pt) by optimizing the expression of Pt dehydrogenase in the exeR genome locus. This ability provided C. glutamicum with a competitive advantage over common contaminating microbes when grown on media containing Pt as a phosphorus source instead of phosphate. As a result, the engineered strain could produce 41.00 g/L l-lysine under nonsterile conditions during batch fermentation for 60 h, whereas the original strain required 72 h to produce 40.78 g/L l-lysine under sterile conditions. Therefore, the recombinant strain can efficiently produce l-lysine under nonsterilized conditions with unaffected production efficiency. Although this anticontamination strategy has been previously reported for other species, this is the first time it has been demonstrated in C. glutamicum; these findings should aid in the further development of cost-efficient amino acid fermentation processes.

In order to prevent the inter-molecular aggregation and retard electron recombination, blocking side substituents, i.e. alkyl and alkylphenyl, were incorporated into the bithiophene bridge and two new carbazole-based sensitizers (CzD2 and CzD3) were synthesized. A reference dye (CzD1) comprising bithiophene spacer was also synthesized for comparative purposes. Their photophysical, electrochemical, structural and electronic properties were extensively investigated for highlighting the effects of side substituents. Moreover, their photovoltaic properties were evaluated using cobalt-containing electrolyte. The CzD3 with the bulkiest side group yielded the highest power conversion efficiency (PCE) of 6.20% due to the largest open circuit voltage (Voc) and short circuit photocurrent (Jsc). Furthermore, incident photon-to-current efficiency (IPCE) spectra and electrochemical impedance spectroscopy (EIS) analysis were performed to reveal the impact of side substituents on the performance of devices. Therefore, this work demonstrates that incorporating blocking side groups into the π-bridge is an effective way to obtain high PCEs of sensitized cells with cobalt redox.

Electrochemistry has been successfully applied in metal catalysis to avoid the usage of chemical redox agents. This strategy proved to be a powerful approach to construct carbon-carbon (C-C) and carbon-heteroatom (C-X) bonds. However, most of the developed methods are based on either anodic oxidation or cathodic reduction, in which a sacrificial reaction occurs at the counter electrode. Paired electrolysis merging with metal catalysis is underdeveloped, wherein both anodic and cathodic processes are taking place simultaneously. Herein, we demonstrated that by using esterification of carboxylic acids with aryl halides via paired electrolysis using nickel as the catalyst the respective aryl esters were obtained in good to excellent yields at room temperature in an undivided electrochemical cell.

Plants control water-use efficiency (WUE) by regulating water loss and CO2 diffusion through stomata. Variation in stomatal control has been reported among lineages of vascular plants, thus giving rise to the possibility that different lineages may show distinct WUE dynamics in response to water stress. Here, we compared the response of gas exchange to decreasing leaf water potential among four ferns and nine seed plant species exposed to a gradually intensifying water deficit. The data collected were combined with those from 339 phylogenetically diverse species obtained from previous studies. In well-watered angiosperms, the maximum stomatal conductance was high and greater than that required for maximum WUE, but drought stress caused a rapid reduction in stomatal conductance and an increase in WUE in response to elevated concentrations of abscisic acid. However, in ferns, stomata did not open beyond the optimum point corresponding to maximum WUE and actually exhibited a steady WUE in response to dehydration. Thus, seed plants showed improved photosynthetic WUE under water stress. The ability of seed plants to increase WUE could provide them with an advantage over ferns under drought conditions, thereby presumably increasing their fitness under selection pressure by drought.

The performance of classical lithium-ion technologies based on liquid electrolytes has made great advances in the last two decades, but safety issues are inevitable for batteries assembled with liquid electrolytes, which have intrinsic instability. In response to this issue, solid polymer electrolytes are developed in the lithium batteries field extensively for improving safety issues, as well as miniaturizing and enhancing the energy densities. Considering the great advantages of polymerized ionic networks, such as facile synthesis, high charge density, and high stability, two polymerized ionic networks (PDM-TFSI-1 and PDM-TFSI-2) with different polysubstituted benzene groups have been developed. The new type of polymerized ionic network with cross-linked structure was synthesized by the simple radical copolymerization of 2-(dimethylamino)ethyl methacrylate and methyl methacrylate monomers, then the copolymer (Mₙ = 14.5 kg mol⁻¹) reacted with polysubstituted bromobenzene to form a cross-linked structure, and finally this was ion exchanged with bis(trifluoromethane)sulfonimide lithium salt (LiTFSI). The ionic networks filled with ionic liquid/LiTFSI mixture exhibit high ionic conductivity (1.0 × 10–⁴ and 1.9 × 10–⁴ S cm–¹) and high decomposition potential (4.7 V vs Li/Li⁺) at 30 °C. The batteries were assembled by sandwiching the obtained polymer electrolytes between a LiFePO₄ cathode and a lithium anode, exhibiting good cycling stability and specific capacity, suggesting that these novel kinds of solid polymer electrolyte are promising for application in next-generation lithium-ion batteries.

A novel strategy for the N-arylation of NH-sulfoximines has been developed by merging nickel catalysis and electrochemistry (in an undivided cell), thereby providing a practical method for the construction of sulfoximine derivatives. Paired electrolysis is employed in this protocol, so a sacrificial anode is not required. Owing to the mild reaction conditions, excellent functional group tolerance and yield are achieved. A preliminary mechanistic study indicates that the anodic oxidation of a NiII species is crucial to promote the reductive elimination of a C-N bond from the resulting NiIII species at room temperature.

It is well established that ferroptosis is primarily induced by peroxidation of long-chain poly-unsaturated fatty acid (PUFA) through nonenzymatic oxidation by free radicals or enzymatic stimulation of lipoxygenase. Although there is emerging evidence that long-chain saturated fatty acid (SFA) might be implicated in ferroptosis, it remains unclear whether and how SFA participates in the process of ferroptosis. Using endogenous metabolites and genome-wide CRISPR screening, we have identified FAR1 as a critical factor for SFA-mediated ferroptosis. FAR1 catalyzes the reduction of C16 or C18 saturated fatty acid to fatty alcohol, which is required for the synthesis of alkyl-ether lipids and plasmalogens. Inactivation of FAR1 diminishes SFA-dependent ferroptosis. Furthermore, FAR1-mediated ferroptosis is dependent on peroxisome-driven ether phospholipid biosynthesis. Strikingly, TMEM189, a newly identified gene which introduces vinyl-ether double bond into alkyl-ether lipids to generate plasmalogens abrogates FAR1-alkyl-ether lipids axis induced ferroptosis. Our study reveals a new FAR1-ether lipids-TMEM189 axis dependent ferroptosis pathway and suggests TMEM189 as a promising druggable target for anticancer therapy.

Herein, chemical activation of chitosan gel by KNO3 to prepare nitrogen-doped carbon. The sol-gel method enabled the activation agent KNO3 to be evenly dispersed in the carbon precursor, thereby ge...

Breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp) are co-located at blood–brain barrier (BBB) cells, preventing their substrates from entering brain. Accumulating evidence demonstrates that liver failure impairs P-gp and BCRP expression and function in the brain. In the current study, we investigated how liver failure influenced the expression and function of brain BCRP and P-gp in rats subjected to bile duct ligation (BDL). The function of BCRP, P-gp and BBB integrity was assessed using distribution of prazosin, rhodamine 123 and fluorescein, respectively. We showed that BDL significantly decreased BCRP function, but increased P-gp function without affecting BBB integrity. Furthermore, we found that BDL significantly downregulated the expression of membrane BCRP and upregulated the expression of membrane P-gp protein in the cortex and hippocampus. In human cerebral microvascular endothelial cells, NH(4)Cl plus unconjugated bilirubin significantly decreased BCRP function and expression of membrane BCRP protein, but upregulated P-gp function and expression of membrane P-gp protein. The decreased expression of membrane BCRP protein was linked to the decreased expression of membrane radixin protein, while the increased expression of membrane P-gp protein was related to the increased location of membrane ezrin protein. Silencing ezrin impaired membrane location of P-gp, whereas silencing radixin impaired membrane location of BCRP protein. BDL rats showed the increased expression of membrane ezrin protein and decreased expression of membrane radixin protein in the brain. We conclude that BDL causes opposite effects on the expression and function of brain BCRP and P-gp, attributing to the altered expression of membrane radixin and ezrin protein, respectively, due to hyperbilirubinemia and hyperammonemia.

Preparation of high-activity and earth-abundant bifunctional catalysts for efficient electrochemical water splitting are crucial and challenging. Herein, Co-doped Ni3N nanosheets loaded on nickel foam (Co-Ni3N) were synthesized. The as-prepared Co-Ni3N exhibits excellent catalytic activity toward both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in alkaline media. Density functional theory (DFT) calculation reveals that Co-Ni3N with redistribution of electrons not only can facilitate the HER kinetics but also can regulate intermediates adsorption energies for OER. Specifically, the Co-Ni3N exhibits high efficiency and stable catalytic activity, with an overpotential of only 30 and 270 mV at a current density of 10 mA cm-2 for the HER and OER in 1 M KOH, respectively. This work provides strong evidence to the merit of Co doping to improve the innate electrochemical performance in bifunctional catalysts, which might have a common impact in many similar metal-metal nitride electrocatalysts.

Baicalin is the main active component of Scutellaria baicalensis, widely used in traditional Chinese medicine thanks to its various pharmacological effects, such as anti-tumor, anti-inflammatory, and antibacterial properties, as well as cardiovascular, hepatic, and renal protective effect. Recently, the protective effects of baicalin on liver disease have received much more attention. Several studies showed that baicalin protects against several types of liver diseases including viral hepatitis, fatty liver disease, xenobiotic induced liver injury, cholestatic liver injury, and hepatocellular carcinoma, with a variety of pharmacological mechanisms. A comprehensive understanding of the mechanism of baicalin can provide a valuable reference for its clinical use, but up to now, no narrative review is available that summarizes the pharmacological effects of baicalin to clarify its potential use in the treatment of liver diseases. Therefore, this review summarizes the progress of baicalin research and the underlying mechanism in the treatment of various liver diseases, to promote further research and its clinical application. Supplementary Information The online version contains supplementary material available at 10.1007/s43440-021-00227-1.

Posterior capsule opacification (PCO) is one of the most frequent complications in cataract surgery and likely to cause the second loss of vision. Proliferation and migration of postoperative remnants of lens epithelial cells (LECs) on the implanted intraocular lens (IOL) are the leading causes of PCO. Antiproliferative drugs can be an effective solution but also possess some problems including sudden release and accompanying adverse effects to surrounding normal tissues, which greatly limit the clinical trials. In this study, an antiproliferative drug Paclitaxel (Pac) -sustained released hyaluronic acid (HA) and chitosan (CHI) multilayer modified IOL with postoperatively long-term PCO prevention was fabricated

Prussian blue analogs (PBAs) with unique structure show great potential for aqueous potassium-ion batteries (AKIBs). Herein, K2Co[Fe(CN)6] and KNi[Co(CN)6] architectures are developed as the cathode candidates for AKIBs. Moreover, the reaction kinetics detection and DFT calculations are employed to analyse the battery performances.

For the study of various retinal diseases, an accurate quantitative analysis of the retinal layer is essential for assessing the severity of the disease and diagnosing the progression of the disease. Optical coherence tomography (OCT) images can clearly show each layer of the retinal structure and detect subtle early lesions, thus providing a gold standard for the diagnosis of retinal diseases. In this article, we propose a coarse-to-fine retinal layer boundary segmentation method based on the embedded residual recurrent network (ERR-Net) and the graph search (GS). Considering the integrity of information transmission and the dependence of features, we first design a novel end-to-end residual recurrent network to roughly segment the retinal layer boundaries. The proposed ERR-Net not only solves the gradient problem brought by the depth but also fully captures the global spatial structure of the image. Second, we employ a GS algorithm for boundary continuous to make the layer boundary segmentation results more accurate. Finally, we evaluate the effectiveness of the proposed method on three publicly available datasets and compare it with the state-of-the-art methods on each dataset. The quantitative results and visual effects show that the proposed method outperforms the state-of-the-art approaches in the segmentation of retinal layer boundaries in OCT images. Moreover, the results also show that the proposed method has good algorithm stability on three datasets with different sizes, characteristics, and segmentation difficulties.

Controlling the products, i.e. achieving high selectivity, is essential yet challenging for many chemical processes. So far, ex/in situ methods have been reported to prepare selective catalysts; here, we present a distinct operational strategy. To demonstrate its power and simplicity, a high-pressure artificial photosynthetic device (HiPAD) was designed correspondingly to achieve selective and efficient solar-driven photoelectrochemical (PEC) carbon dioxide reduction (CO2R). The HiPAD features a high-pressure operation to enhance the CO2 concentration, as well as straight operations of copper (Cu) catalyst synthesis and Cu-catalyzed PEC CO2R to enhance the active site concentration. This strategy is quantitatively described by the Langmuir mechanism. By leveraging it, CO2R selectivity higher than 80% and solar-to-chemical energy conversion efficiency exceeding 0.9% were experimentally demonstrated. The material and synthesis versatility feature of this strategy was also demonstrated. These results shed new light on selective and efficient catalytic conversions.

The abuse of antibiotics has caused global problems including critical environmental ecology impacts. Herein, four new metal–organic frameworks (MOFs) – {[Cd(HL)(bic)(H2O)]·2H2O}(1), {[Cd3(L)2(bbi)2(H2O)2]·2H2O}(2), [Cd3(L)2(bib)2(H2O)2] (3) and [Cd3(L)2(idy)2] (4), where bic = 3,6-bis(imidazol-1-yl)-9H-carbazole, bbi = 1,1′-(1,4-butanediyl)bis(imidazole), bib =1,4-bis(1-imidazoly)benzene and idy = 2-imidazol-1-ylpyridine – have been synthesized and fully characterized. 1 is a 1D chain with a large loop, stacked parallel to each other in 2D supramolecular layers by hydrogen-bonded and packing interactions. 2 and 3 are isostructural and show a 3D (3,8)-connected tfz-type network with (43)2(46·618·84) topology. 4 has a 2D grid framework. The oxygen atom of the ether-bridging group acts as a Lewis base site, which improves the connection strength and allows the detection of 11 types of antibiotics through the fluorescence quenching effect. Among them, 2 exhibits sensitive and selective detection for nitrofural (NZF) (KSV = 8.26 × 103 M−1 and LOD = 1.83 ppm). Moreover, the highly selective probe behavior towards NZF ions could be maintained even if there are other interfering antibiotics.

Carbon microspheres were synthesized using itaconic acid fermentation waste liquid as the raw material by the hydrothermal method. The sequential porous adsorbent was prepared (by chemical activation) using carbon microspheres as a carbonaceous framework. The adsorbent was characterized by SEM, BET, Raman, XRD, XPS, and elemental analysis. Also, the adsorption performance of the adsorbent was tested using the batch adsorption method. The effects of several parameters such as pH, adsorbent dose, and concentration of Cr(VI) on the sorption of Cr(VI) were investigated. The results indicate that an outstanding adsorbent with a specific surface area of 1802.16 m2 g−1 and a maximum adsorption capacity for Cr(VI) of 270.14 mg g−1 has been acquired. According to the adsorption isotherm model, the kinetic model, and the intra-particle diffusion model, it was found that the adsorption process of Cr(VI) by the adsorbent conforms to the Freundlich model and the quasi-second-order kinetic model. The evaluation of the thermodynamic parameters (ΔH > 0, ΔS > 0, and ΔG < 0) revealed that the adsorption process was endothermic and spontaneous. The mechanistic studies showed that the adsorption of Cr(VI) likely involved electrostatic attraction and a redox reaction. After 5 cycles of repeated usage, the adsorbent maintains good adsorption stability to Cr(VI), favoring its practical application.