Chitosan Composite Membrane with Efficient Hydroxide Ion Transport via Nano-Confined Hydrogen Bonding Network for Alkaline Zinc-Based Flow Batteries.

The development of membranes with rapid and selective ionic transport is imperative for diverse electrochemical energy conversion and storage systems, including fuel cells and flow batteries. However, the practical application of membranes is significantly hindered by their limited conductivity and stability under strong alkaline conditions. Herein, a unique composite membrane decorated with functional Cu2+ cross-linked chitosan (Cts-Cu-M) is reported and their high hydroxide ion conductivity and stability in alkaline flow batteries are demonstrated. The underlying hydroxide ions transport of the membrane through Cu2+ coordinated nano-confined channels with abundant hydrogen bonding network via Grotthuss (proton hopping) mechanism is proposed. Consequently, the Cts-Cu-M membrane achieves high hydroxide ion conductivity with an area resistance of 0.17 Ω cm2 and enables an alkaline zinc-based flow battery to operate at 320 mA cm-2, along with an energy efficiency of ≈80%. Furthermore, the membrane enables the battery for 200 cycles of long-cycle stability at a current density of 200 mA cm-2. This study offers an in-depth understanding of ion transport for the design and preparation of high-performance membranes for energy storage devices and beyond.

A novel hydrophobic carborane-hybrid microporous material for reversed C2H6 adsorption and efficient C2H4/C2H6 separation under humid conditions.

Since ethylene (C2H4) is important feedstock in the chemical industry, developing economical and energy-efficient adsorption separation techniques based on ethane (C2H6)-selective adsorbents to replace the energy-intensive cryogenic distillation is highly demanded, which however remains a daunting challenge. While previous anionic boron cluster hybrid microporous materials display C2H4-selective features, we herein reported that the incorporation of a neutral para-carborane backbone and aliphatic 1,4-diazabicyclo[2.2.2]octane (DABCO) enables the reversed adsorption of C2H6 over C2H4. The generated carborane-hybrid microporous material ZNU-10 (ZNU = Zhejiang Normal University) is highly stable in humid air and maintains good C2H6/C2H4 separation performance under high humidity. Gas loaded single crystal structure and density-functional theory (DFT) calculations revealed that the weakly polarized carborane and DABCO within ZNU-10 induce more specific C-Hδ+⋯Hδ--B dihydrogen bonds and other van der Waals interactions with C2H6, while the suitable pore space allows the high C2H6 uptake. Approximately 14.5 L kg-1 of polymer grade C2H4 can be produced from simulated C2H6/C2H4 (v/v 10/90) mixtures under ambient conditions in a single step, comparable to those of many popular materials.

Using a New Fe3O4@CPAM Magnetic Flocculant and Microwave to Demulsify Heavy Oil-in-Water Emulsions.

In this study, cationic polyacrylamide (CPAM)-coated magnetic nanoparticles (MNPs) Fe3O4@CPAM were synthesized for treating heavy O/W emulsions. This Fe3O4@CPAM was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM) techniques, and its synergistic performances with microwaves were evaluated in detail with respect to the microwave radiation power, radiation time, and magnetic nanoparticle concentration. On this basis, the distribution of oil droplets and the wettability and chargeability of magnetic nanoparticles were measured without or with microwave radiation using biomicroscopy, contact angle measurement instrument, and a ζ-potential analyzer, thus revealing the synergistic demulsification mechanism between microwave and magnetic nanoparticles. The results showed that excessively high or low microwave radiation parameters had an inhibitory effect on the magnetic nanoparticle demulsification, and microwave promoted the magnetic nanoparticle demulsification only when the radiation parameters were in the optimal range. In addition, the water separation rate showed an increasing and then decreasing trend with the increase of magnetic nanoparticles concentration, with or without microwave action. As an example, the water separation rate of the emulsion for 1 h was 21.34% when the Fe3O4 concentration was 175 mg/L without microwave action, while it increased to 55.56% with microwave action. In contrast, when the concentration of Fe3O4@CPAM was 175 mg/L, the water separation rate was 42.86% without microwave radiation, while it was further increased to 77.38% under microwave radiation. These results indicate that magnetic nanoparticles and their complexes significantly affect the water separation process under different conditions. There is a more obvious coupling synergistic effect between Fe3O4@CPAM and microwave. This was due to the lower absolute potential of Fe3O4@CPAM and its higher hydrophobicity.

Selective sorting of hexane isomers by anion-functionalized metal-organic frameworks with optimal energy regulation.

Extensive efforts have been made to improve the separation selectivity of hydrocarbon isomers with nearly distinguishable boiling points; however, how to balance the high regeneration energy consumption remains a daunting challenge. Here we describe the efficient separation of hexane isomers by constructing and exploiting the rotational freedom of organic linkers and inorganic SnF62- anions within adaptive frameworks, and reveal the nature of flexible host-guest interactions to maximize the gas-framework interactions while achieving potential energy storage. This approach enables the discrimination of hexane isomers according to the degree of branching along with high capacity and record mono-/di-branched selectivity (6.97), di-branched isomers selectivity (22.16), and upgrades the gasoline to a maximum RON (Research Octane Number) of 105. Benefitting from the energy regulation of the flexible pore space, the material can be easily regenerated only through a simple vacuum treatment for 15 minutes at 25 °C with no temperature fluctuation, saving almost 45% energy compared to the commercialized zeolite 5 A. This approach could potentially revolutionize the whole scenario of alkane isomer separation processes.

A rare case of an unexpected trigger of paroxysmal atrial fibrillation in the right atrial appendage diverticulum.

INTRODUCTION: We described a rare case of an adolescent girl with paroxysmal atrial fibrillation originating from the right atrial appendage diverticulum and successfully converted to sinus rhythm after surgical intervention. METHODS: A 19-year-old girl was referred to the hospital for a catheter ablation of paroxysmal atrial fibrillation. conventional radiofrequency ablation using 3-D mapping were ineffective. Activation mapping showed the root of the free wall atrial appendage was first excited and catheter modeling (3D Carto map) showed a sac-like structure. RESULTS: We did selective angiography and further Computed tomography angiography (CTA) and Transesophageal echocardiography (TEE) which showed diverticulum originating from the right atrial appendage. Hence the patient was referred to cardiac surgery and had no recurrent atrial fibrillation at three months postoperative follow up. CONCLUSIONS: Right atrial appendage diverticulum was an extremely rare malformation that can coexist with atrial tachyarrhythmia. Surgical ligation or excision of the abnormal structure with local ablation can achieve excellent results.

Study on the Effect of Polymer-Modified Magnetic Nanoparticles on Viscosity Reduction of Heavy Oil Emulsion.

To overcome the problems of large dosage, fast sedimentation, and the unsatisfactory emulsification effect of traditional magnetic nanoparticles, polymer-modified magnetic nanoparticle Co3O4@HPAM was synthesized as an emulsifier for heavy oil O/W emulsion by modifying the surface of Co3O4. The composition of Co3O4@HPAM was characterized by Fourier transform infrared spectroscopy, X-ray diffraction analysis, thermogravimetric analysis, and scanning electron microscopy. Then, the effects of the mass fraction of magnetic nanoparticles before and after modification on the stability and rheology of the emulsion were compared and analyzed. The experiments show that the degree of reduction of the water-separation rate under the action of Co3O4@HPAM was 13 times higher than that under the action of Co3O4 at the same mass fraction. By using Co3O4@HPAM, the water separation of the emulsion was only 6.74% at 4 h, while the viscosity reduction was greater than 97% at a mass fraction of 0.04%. Finally, combined with the test results of zeta potential, interfacial tension, contact angle, and oil droplet distribution, the effect mechanism of Co3O4@HPAM on the viscosity reduction of heavy oil emulsification was investigated. It is found that the polymer-modified magnetic nanoparticles have stronger negative electricity, a larger contact angle, and smaller interfacial tension, while the oil droplets under their action have a smaller radius and a more homogeneous distribution. The research in this paper provides a theoretical basis for the application of magnetic nanoparticles in heavy oil emulsification and viscosity reduction technology.

First principles molecular dynamics simulation and thermal decomposition kinetics study of CL-20.

CONTEXT: 2,4,6,8,10, 12-hexanitro-2,4,6,8,10, 12-hexazepane (CL-20) is a new energetic material with high performance and low sensitivity. In-depth study of the thermal decomposition mechanism of CL-20 is a necessary condition to improve its performance, ensure its safety, and optimize its application. On the basis of a large number of empirical force fields used in molecular dynamics simulation in the past, the machine learning augmented first-principles molecular dynamics method was used for the first time to simulate the thermal decomposition reaction of CL-20 at 2200 K, 2500 K, 2800 K, and 3000 K isothermal temperature. The main stable resulting compounds are N2, CO2, CO, H2O, andH2, where CO2 and H2O continue to decompose at higher temperatures. The initial decomposition pathways are denitration by N-N fracture, ring-opening by C-N bond fracture, and redox reaction involving NO2 and CL-20. After ring opening, two main compounds, fused tricyclic pyrazine and azadicyclic, were formed, which were decomposed continuously to form monocyclic pyrazine and pyrazole ring structures. The most common fragments formed during decomposition are those containing two, three, four, and six carbons. The formation rule and quantity of main small molecule intermediates and resulting stable products under different simulated temperatures were analyzed. METHODS: Based on ab initio Bayesian active learning algorithm, efficient and accurate prediction of CL-20 is made using the dynamic machine learning function of Vienna Ab-Initio Simulation Package (VASP), which constructs the energy potential surface by learning a large number of data based on AIMD calculations. The result is a machine learning force field (MLFF). Then the molecular dynamics of CL-20 was simulated using the trained MLFF model. PAW pseudopotentials and generalized gradient approximation (GGA), namely, Perdew-Burke-Ernzerhof (PBE) functional, are used in the calculation. The plane wave truncation energy (ENCUT) is set to 550 eV, and using the Gaussian broadening, the thermal broadening size of the single-electron orbital is 0.05 eV. A van der Waals revision of the system with Grimme Version 3. The energy convergence accuracy (EDIFF) of electron self-consistent iteration is set to 1E-5 eV and 1E-6 eV, respectively. The two-step structure optimization is carried out using 1'1'1 k point grid and conjugate gradient method. The ENCUT was changed to 500 eV and EDIFF to 1E-5 eV, and NVT integration (ISIF = 2) of Langevin thermostat was used for machine learning force field training and AIMD simulation of the system.

A molecular sieve with ultrafast adsorption kinetics for propylene separation.

The design of molecular sieves is vital for gas separation, but it suffers from a long-standing issue of slow adsorption kinetics due to the intrinsic contradiction between molecular sieving and diffusion within restricted nanopores. We report a molecular sieve ZU-609 with local sieving channels that feature molecular sieving gates and rapid diffusion channels. The precise cross-sectional cutoff of molecular sieving gates enables the exclusion of propane from propylene. The coexisting large channels constituted by sulfonic anions and helically arranged metal-organic architectures allow the fast adsorption kinetics of propylene, and the measured propylene diffusion coefficient in ZU-609 is one to two orders of magnitude higher than previous molecular sieves. Propylene with 99.9% purity is obtained through breakthrough experiments with a productivity of 32.2 L kg-1.

Specific Propyne Trapping Sites within a Robust MOF for Efficient Propyne/Propadiene Separation with Record Propadiene Productivity.

Separating propyne/propadiene to produce pure propadiene is extremely challenging in industry due to their similar properties. Herein, a novel ZrF6 2- anion pillared cage-like metal-organic framework (termed as CuZrF6 -TPA) for highly efficient propyne/propadiene separation is reported. It exhibits high propyne capacity (177.4/188.6 cm3 /cm3 at 0.5/1.0 bar and 298 K), benchmark separation selectivity (6.0), and remarkable separation potential (5.7 mol L-1 ) simultaneously. Record propadiene productivity (≈4.7 mol L-1 ) is achieved through a single adsorption process in breakthrough experiments with excellent recycle stability even under humid conditions. Based on the structure of propyne-loaded single crystals, two binding sites are identified, including a major propyne trapping site at the windows and a minor binding site located in the large cages. Modelling studies further confirm that the contracted cage windows surrounded with rotating Lewis basic F atoms and aromatic rings are the optimal bonding sites to capture propyne with multiple hydrogen bonding and π···π interactions.

Effect of 40 Hz light flicker on cognitive impairment and transcriptome of hippocampus in right unilateral common carotid artery occlusion mice.

Vascular cognitive impairment caused by chronic cerebral hypoperfusion (CCH) seriously affects the quality of life of elderly patients. However, there is no effective treatment to control this disease. This study investigated the potential neuroprotective effect of the 40 Hz light flicker in a mouse model of CCH. CCH was induced in male C57 mice by right unilateral common carotid artery occlusion (rUCCAO), leading to chronic brain injury. The mice underwent 40 Hz light flicker stimulation for 30 days after surgery. The results showed that 40 Hz light flicker treatment ameliorated memory deficits after rUCCAO and alleviated the damage to neurons in the frontal lobe and hippocampus. Light flicker administration at 40 Hz decreased IL-1ß and TNF-α levels in the frontal lobe and hippocampus, but immunohistochemistry showed that it did not induce angiogenesis in mice with rUCCAO. Gene expression profiling revealed that the induction of genes was mainly enriched in inflammatory-related pathways. Our findings demonstrate that 40 Hz light flicker can suppress cognitive impairment caused by rUCCAO and that this effect may be involved in the attenuation of neuroinflammation.

Direct prediction of gas adsorption via spatial atom interaction learning.

Physisorption relying on crystalline porous materials offers prospective avenues for sustainable separation processes, greenhouse gas capture, and energy storage. However, the lack of end-to-end deep learning model for adsorption prediction confines the rapid and precise screen of crystalline porous materials. Here, we present DeepSorption, a spatial atom interaction learning network that realizes accurate, fast, and direct structure-adsorption prediction with only information of atomic coordinate and chemical element types. The breakthrough in prediction is attributed to the awareness of global structure and local spatial atom interactions endowed by the developed Matformer, which provides the intuitive visualization of atomic-level thinking and executing trajectory in crystalline porous materials prediction. Complete adsorption curves prediction could be performed using DeepSorption with a higher accuracy than Grand canonical Monte Carlo simulation and other machine learning models, a 20-35% decline in the mean absolute error compared to graph neural network CGCNN and machine learning models based on descriptors. Since the established direct associations between raw structure and target functions are based on the understanding of the fundamental chemistry of interatomic interactions, the deep learning network is rationally universal in predicting the different physicochemical properties of various crystalline materials.

Changes in Plasma TPH2, GDNF, Trk-b, BDNF, and proBDNF in People Who Died by Suicide.

Recent studies have shown that neuropeptides and neurotrophic factors may be involved in the pathophysiological mechanisms of suicide. However, the current research on this aspect is still insufficient. Our study aimed to explore the biological patterns of suicide deaths, including levels of BDNF, proBDNF, BDNF/proBDNF, Trk-b, GDNF, and TPH2. The researchers selected 25 normal control patients matched by age with 30 suicide deaths. We used enzyme-linked immunosorbent assays to detect the levels of BDNF, proBDNF, BDNF/proBDNF, Trk-b, GDNF, and TPH2 in the plasma of suicide and control subjects. proBDNF, BDNF/proBDNF, Trk-b, GDNF, and TPH2 levels are shown as the median (25th-75th percentile). BDNF levels are shown as the mean (standard error of the mean). (1) The levels of plasma TPH2 and proBDNF in people who died by suicide were significantly higher than those in the control group. (2) The plasma levels of GDNF and BDNF/proBDNF in the suicide group were obviously lower than those in the control group. (3) There was no significant difference in plasma BDNF or Trk-b concentrations between the suicide group and the control group.Plasma TPH2, GDNF, and proBDNF levels are related to suicide. Plasma neurotrophic factor markers may predict suicide risk.

Quantifying the partial ionization effect of gold in the transition region between condensed matter and warm dense matter.

It is now well known that solids under ultra-high-pressure shock compression will enter the warm dense matter (WDM) regime which connects condensed matter and hot plasma. How condensed matter turns into the WDM, however, remains largely unexplored due to the lack of data in the transition pressure range. In this letter, by employing the unique high-Z three-stage gas gun launcher technique developed recently, we compress gold into TPa shock pressure to fill the gap inaccessible by the two-stage gas gun and laser shock experiments. With the aid of high-precision Hugoniot data obtained experimentally, we observe a clear softening behavior beyond ~560 GPa. The state-of-the-art ab-initio molecular dynamics calculations reveal that the softening is caused by the ionization of 5d electrons in gold. This work quantifies the partial ionization effect of electrons under extreme conditions, which is critical to model the transition region between condensed matter and WDM.

Insights into the thermodynamic-kinetic synergistic separation of propyne/propylene in anion pillared cage MOFs with entropy-enthalpy balanced adsorption sites.

Propyne/propylene (C3H4/C3H6) separation is an important industrial process yet challenged by the trade-off of selectivity and capacity due to the molecular similarity. Herein, record C3H4/C3H6 separation performance is achieved by fine tuning the pore structure in anion pillared MOFs. SIFSIX-Cu-TPA (ZNU-2-Si) displays a benchmark C3H4 capacity (106/188 cm3 g-1 at 0.01/1 bar and 298 K), excellent C3H4/C3H6 IAST selectivity (14.6-19.3) and kinetic selectivity, and record high C3H4/C3H6 (10/90) separation potential (36.2 mol kg-1). The practical C3H4/C3H6 separation performance is fully demonstrated by breakthroughs under various conditions. 37.8 and 52.9 mol kg-1 of polymer grade C3H6 can be produced from 10/90 and 1/99 C3H4/C3H6 mixtures. 4.7 mol kg-1 of >99% purity C3H4 can be recovered by a stepped desorption process. Based on the in situ single crystal analysis and DFT calculation, an unprecedented entropy-enthalpy balanced adsorption pathway is discovered. MD simulation further confirmed the thermodynamic-kinetic synergistic separation of C3H4/C3H6 in ZNU-2-Si.

Ultrafast modulation of a high harmonic generation in a bulk ZnO single crystal.

Optical modulation of high harmonic generation (HHG) is of fundamental interest in science and technology, which can facilitate understanding of HHG generation mechanisms and expand the potential optoelectronic applications. However, the current established works have neither shown the advanced modulation performance nor provided a deep understanding of modulation mechanisms. In this work, taking wurtzite zinc oxide (ZnO) single crystal as a prototype, we have demonstrated an all-optical intensity modulation of high-order HHG with a response time of less than 0.2 ps and a depth of more than 95%, based on the pump-probe configuration with two different pumping wavelengths. Besides the achieved excellent modulation performance, we have also revealed that the modulation dynamics in ZnO single crystal highly depend on the excitation conditions. Specifically, the modulation dynamics with the near-bandgap or above-bandgap excitation are attributed to the non-equilibrium interband carrier relaxations, while for mid-gap excitation, the modulation dynamics are dominated by the nonlinear frequency mixing process. This work may enhance the current understanding of the HHG modulation mechanism and enlighten novel device designs.

Excimer Formation in the Non-Van-Der-Waals 2D Semiconductor Bi2 O2 Se.

The layered semiconductor Bi2 O2 Se is a promising new-type 2D material that holds layered structure via electrostatic forces instead of van der Waals (vdW) attractions. Aside from the huge success in device performance, the non-vdW nature in Bi2 O2 Se with a built-in interlayer electric field has also provided an appealing platform for investigating unique photoexcited carrier dynamics. Here, experimental evidence for the observation of excimers in multilayer Bi2 O2 Se nanosheets via transient absorption spectroscopy is presented. It is found that the excimer formation is the primary decay pathway of photoexcited excitons and three-stage excimer dynamics with corresponding time scales are established. Excitation-fluence-dependent excimer dynamics further suggest that the excimer is diffusive and its formation can be simply described as excitons relaxed to an excimer geometry. This work indicates the outstanding promise of unique excitonic processes in Bi2 O2 Se, which may motivate novel device designs.

A Diffused Mini-Sniffing Sensor for Monitoring SO2 Emissions Compliance of Navigating Ships.

The ship exhaust sniffing unmanned aerial vehicle (UAV) system can be applied to monitor vessel emissions in emission control areas (ECAs) to improve the efficiency of maritime law enforcement and reduce ship pollution. To solve the problems of large size, heavy weight and high cost of ship exhaust sniffing sensors, in this paper, a unique diffused mini-sniffing sensor was designed, which provides a low-cost, lightweight, and highly adaptable solution for ship exhaust sniffing UAV. To verify the measurement accuracy of the system, a large number of on-site tests were performed based in the mouth of the Yangtze River, and some cases of violation of the fuel sulfur content (FSC) were verified and punished. Maritime law enforcement officers boarded the ship to take oil samples from eight suspected ships and sent them to the laboratory for testing. The results showed that the FSCs of the eight ships in chemical inspection were all greater than the regulatory limit 0.5% (m/m) of the International Maritime Organization (IMO). The system enables authorities to monitor emissions using rotary UAVs equipped with diffused mini-sniffing sensors to measure the FSC of navigating ships, which couple hardware and operational software with a dedicated lab service to produce highly reliable measurement results. The system offers an effective tool for screening vessel compliance.

Paliperidone Extended Release Versus Olanzapine in Treatment-Resistant Schizophrenia: A Randomized, Double-Blind, Multicenter Study.

PURPOSE: Paliperidone is an atypical antipsychotic as effective as other atypical antipsychotics for schizophrenia. However, few studies have explored the efficacy of paliperidone for treatment-resistant schizophrenia. This study aimed to compare the efficacy and safety of paliperidone extended release (ER) versus olanzapine in schizophrenia patients with either poor treatment response or intolerable adverse effects due to standardized antipsychotic therapy. METHODS: This 12-week randomized, double-blind, multicenter study compared the treatment efficacy on psychotic symptoms, cognitive functions, and tolerance between paliperidone ER (6-15 mg/d, n = 45) and olanzapine (10-30 mg/d, n = 41) in treatment-resistant or treatment-intolerant patients with schizophrenia. The severity of psychotic symptoms was evaluated by the Positive and Negative Syndrome Scale and the Clinical Global Impression Severity of Illness Scale. The cognitive functions were assessed by the MATRICS Consensus Cognitive Battery. In addition, the metabolic impacts were evaluated by weight gain and waist circumference. RESULTS: Patients with either paliperidone ER or olanzapine treatment showed apparent improvement in psychotic symptoms, without significant intergroup difference. Twelve-week paliperidone ER or olanzapine treatment did not improve the cognitive functions. Both paliperidone ER and olanzapine treatment caused significant increase in weight and waist circumference, and olanzapine had a greater impact on waist circumference than paliperidone ER. In addition, both drugs were well tolerated. CONCLUSIONS: Paliperidone ER could be a safe alternative for treatment-resistant schizophrenia.

Sample entropy based prescribed performance control for tailless aircraft.

This paper proposes a sample entropy (SampEn) based prescribed performance controller (SPPC) for the longitudinal control of a supersonic tailless aircraft subject to model uncertainty and nonlinearity. Considering that SampEn can evaluate the system's stability, a SampEn-based feedback adjust system (SFAS) is developed in this paper. With the help of SFAS, the SPPC could identify the dangerous chattering in the status signal that may lead the aircraft to lose control and make appropriate adjustments to feedback. Besides, the SPPC does not require any accurate model information and only needs to know the rough trend of dynamic functions. Although no adaptive or robust control mechanisms are introduced, the SPPC shows robustness against model uncertainty utilizing the nonlinear error feedback. Compared with traditional prescribed performance control (TPPC), the SPPC achieves better performance and safer flight. The whole control structure is developed through the backstepping technique, and the closed-loop stability is proved. At last, the advance of SPPC is verified via simulation using a high-fidelity tailless aircraft model, and the inner mechanisms of SPPC are further discussed.

One-step removal of alkynes and propadiene from cracking gases using a multi-functional molecular separator.

Refineries generally employ multiple energy-intensive distillation/adsorption columns to separate and purify complicated chemical mixtures. Materials such as multi-functional molecular separators integrating various modules capable of separating molecules according to their shape and chemical properties simultaneously may represent an alternative. Herein, we address this challenge in the context of one-step removal of alkynes and propadiene from cracking gases (up to 10 components) using a multi-functional and responsive material ZU-33 through a guest/temperature dual-response regulation strategy. The responsive and guest-adaptive properties of ZU-33 provide the optimized binding energy for alkynes and propadiene, and avoid the competitive adsorption of olefins and paraffins, which is verified by breakthrough tests, single-crystal X-ray diffraction experiments, and simulation studies. The responsive properties to different stimuli endow materials with multiple regulation methods and broaden the boundaries of the applicability of porous materials to challenging separations.