[Research progress on structure and hydrological processes in the karst critical zone of southwest China]. / è¥¿å—å–€æ–¯ç‰¹å ³é”®å¸¦ç»“æž„åŠå ¶æ°´æ–‡è¿‡ç¨‹ç ”ç©¶è¿›å±•.

The southwestern region of China is the largest exposed karst area in the world and serves as an important ecological security barrier for the upstream of Yangtze River and Pearl River. Different from the critical zone of non-karst areas, the epikarst, formed by an interwoven network of denudation pores, is the core area of karst critical zone. Water is the most active component that participates in internal material cycle and energy flow within the critical zone. We reviewed relevant research conducted in the southwestern region from three aspects: the characte-rization of critical zone structure, the hydrological processes of soil-epikarst system, and their model simulations. We further proposed potential research hotpots. The main approach involved multi-scale and multi-method integrated observations, as well as interdisciplinary collaboration. Precisely characterizing the eco-hydrological processes of the vegetation-soil-epikarst coupling system was a new trend in the future research. This review would provide scientific reference for further studies on hydrological processes in critical zones and regional hydrological water resource management in karst areas.

Associations between Total Atherosclerosis Burden of Baroreceptor-Resident Arteries and ECG Abnormalities after Acute Ischemic Stroke.

Electrocardiogram (ECG) abnormalities are the most common cardiac complications after acute ischemic stroke (AIS) and predict poor outcomes. The arterial baroreflex is an essential determinant of cardiovascular autonomic regulation, with receptors mainly residing in carotid sinuses and aortic arch. The atherosclerosis of these baroreceptor-resident arteries (BRA) is very common in AIS patients and might impair baroreflex function. However, the associations between the atherosclerosis of BRA and ECG abnormalities after AIS are still unknown. In total, 228 AIS patients within 7 days after onset without a pre-existing heart disease were prospectively recruited. With computed tomography angiography, atherosclerosis conditions in 10 segments of the carotid sinuses and aortic arch were scored and summed as the Total Atherosclerosis Burden of BRA (TAB-BRA), and asymptomatic coronary artery stenosis (ACAS) ≥50% was simultaneously assessed. We performed 12-lead ECG to dynamically detect abnormal repolarization, and 24 h Holter ECG to monitor arrhythmias and heart rate variability (HRV) parameters, which are reliable indicators to assess cardiac autonomic function. We found that TAB-BRA was positively associated with abnormal repolarization (OR 1.09; CI% 1.03-1.16; p = 0.003) and serious cardiac arrhythmias (OR 1.08; CI% 1.01-1.15; p = 0.021). In addition, TAB-BRA was an important predictor of abnormal repolarization, persisting over 3 days (OR 1.17; CI% 1.05-1.30; p = 0.003). However, ACAS ≥ 50% did not relate to these ECG abnormalities. TAB-BRA was negatively correlated with parasympathetic-related HRV parameters. Our results indicated that AIS patients with a high TAB-BRA are more likely to have ECG abnormalities and delayed normalization, which may relate to the decreased cardiac parasympathetic activity, but not the accompanied ACAS ≥ 50%.

Optical properties and molecular compositions of dissolved organic matter in multiple runoff components during rainfalls on the karst hillslope.

Understanding the chemical composition, origin, and molecular structure of dissolved organic matter (DOM) in multi-interface runoff is essential for comprehending the fate of laterally transported DOM in complex soil-epikarst systems of karst hillslopes. Limited information, however, is available for the optical properties and molecular compositions of the transported OM in multiple runoff components on the karst hillslope in relation to land-uses and soil thicknesses. In this study, we conducted a study to observe the changes in the quantity and quality of DOM in multiple interface flow (surface, subsurface, and epikarst) during natural rainfall events in 2022 in karst hillslopes that are covered by different land uses (cropland and shrubland) and soil thicknesses (with mean depths of 66.0 cm for deeper soil and 35.4 cm for shallower soil) in the karst region of southwest China. chemcial compositions of runoff DOM were determined by optical analysis and microbial compositions in runoff were inferred with high-throughput sequencing. The results showed that the soil-epikarst structure was controlling the runoff DOM quantity and quality during rainfall events. A decrease in the aromaticity, humification, unsaturation, and oxidation degree and an increase in carbohydrate, aminosugars, protein, and lipid compounds were found from surface to epikarst flow, indicating that plant-and soil-derived carbon decreased, while the microbially-derived carbon increased. The results were further comfirmed by the higher bacterial richness and diversity, along with fungal diversity in the epikarst flow compared to other runoff components. The bio-labile protein materials (C2) were the most important component of runoff DOM output in karst hillslopes. In surface and subsurface flow, rainfall amount, runoff rate, and discharge significantly affected the DOM concentration and quality during rainfalls, indicating that the dynamics of DOM in runoff from karst hillslopes were predominantly influenced by hydrological processes. Furthermore, the runoff DOM quality in cropland was dominated by lower unsaturation and oxidation degrees and higher protein component, compared to those in shrubland. The compositions of DOM in runoff from hillslope plots with thicker soils were primarily characterized by microbially-derived materials. Our findings were conducive to understanding the mechanism governing the migration of DOM quality and quantity in discharge during multi-interface hydrological processes on karst hillslopes.

Study on high-precision three-dimensional reconstruction of pulmonary lesions and surrounding blood vessels based on CT images.

The adoption of computerized tomography (CT) technology has significantly elevated the role of pulmonary CT imaging in diagnosing and treating pulmonary diseases. However, challenges persist due to the complex relationship between lesions within pulmonary tissue and the surrounding blood vessels. These challenges involve achieving precise three-dimensional reconstruction while maintaining accurate relative positioning of these elements. To effectively address this issue, this study employs a semi-automatic precise labeling process for the target region. This procedure ensures a high level of consistency in the relative positions of lesions and the surrounding blood vessels. Additionally, a morphological gradient interpolation algorithm, combined with Gaussian filtering, is applied to facilitate high-precision three-dimensional reconstruction of both lesions and blood vessels. Furthermore, this technique enables post-reconstruction slicing at any layer, facilitating intuitive exploration of the correlation between blood vessels and lesion layers. Moreover, the study utilizes physiological knowledge to simulate real-world blood vessel intersections, determining the range of blood vessel branch angles and achieving seamless continuity at internal blood vessel branch points. The experimental results achieved a satisfactory reconstruction with an average Hausdorff distance of 1.5 mm and an average Dice coefficient of 92%, obtained by comparing the reconstructed shape with the original shape,the approach also achieves a high level of accuracy in three-dimensional reconstruction and visualization. In conclusion, this study is a valuable source of technical support for the diagnosis and treatment of pulmonary diseases and holds promising potential for widespread adoption in clinical practice.

Association between High-Sensitivity C-Reactive Protein and Blood Pressure Variability in Subacute Stage of Ischemic Stroke.

The determinants of blood pressure variability (BPV) are complex. We aimed to evaluate whether circulating high-sensitivity C-reactive protein (hsCRP) is associated with short-term BPV during the subacute stage of ischemic stroke. In this observational study, a consecutive series of acute ischemic stroke patients who underwent 24 h ambulator blood pressure monitoring (ABPM) during day 4 to 10 after onset were enrolled. Multivariable linear regression models were constructed to assess relationships between hsCRP and BPV. Among a total of 325 patients analyzed, the mean age was 60 years old and 72% were male. The SD, CV, ARV of 24 h SBP and DBP were more likely to be higher in patients with hsCRP ≥ 2 mg/L, and these predispositions remained unchanged in linear regression analyses after adjusting for possible confounding factors, with a dose-response relationship when patients were additionally categorized into quartiles according to hsCRP levels using the lowest quartile as a reference category. In contrast, similar results were observed for the mean of SBP but not the mean of DBP. These results indicate that hsCRP is dose-dependently associated with short-term BPV during the subacute stage of ischemic stroke. These findings suggested that patients with a higher level of hsCRP tended to have larger blood pressure fluctuations.

Double-Layer ePTFE-Reinforced Membrane Electrode Assemblies Prepared by a Reverse Membrane Deposition Process for High-Performance and Durable Proton Exchange Membrane Fuel Cells.

To promote further commercialization of proton exchange membrane (PEM) fuel cells, developing a novel preparation method for high-performance and durable membrane electrode assemblies (MEAs) is imperative. In this study, we adopt the reverse membrane deposition process and expanded polytetrafluoroethylene (ePTFE) reinforcing technology to optimize the interface combination and durability of MEAs simultaneously for the preparation of novel MEAs with double-layer ePTFE reinforcement skeletons (DR-MEA). With the wet-contact between the liquid ionomer solution and porous catalyst layers (CLs), a tight 3D PEM/CL interface is formed in the DR-MEA. Based on this enhanced PEM/CL interface combination, the DR-MEA exhibits a significantly increased electrochemical surface area, reduced interfacial resistance, and improved power performance compared with a conventional MEA (C-MEA) based on a catalyst-coated membrane method. Furthermore, with the reinforcement of double-layer ePTFE skeletons and the support of rigid electrodes for the membranes, the DR-MEA demonstrates less mechanical degradation than the C-MEA after wet/dry cycle test, reflected in lower increase in hydrogen crossover current, interfacial resistance, and charge-transfer resistance and reduced power performance attenuation. With less mechanical degradation, the DR-MEA therefore shows less chemical degradation than the C-MEA after an open-circuit voltage durability test.

A Comparative Study of CCM and CCS Membrane Electrode Assemblies for High-Temperature Proton Exchange Membrane Fuel Cells with a CsH5(PO4)2-Doped Polybenzimidazole Membrane.

Membrane electrode assemblies (MEAs) are critical components in influencing the electrochemical performance of high-temperature proton exchange membrane fuel cells (HT-PEMFCs). MEA manufacturing processes are mainly divided into the catalyst-coated membrane (CCM) and the catalyst-coated substrate (CCS) methods. For conventional HT-PEMFCs based on phosphoric acid-doped polybenzimidazole (PBI) membranes, the wetting surface and extreme swelling of the PA-doped PBI membranes make the CCM method difficult to apply to the fabrication of MEAs. In this study, by taking advantage of the dry surface and low swelling of a CsH5(PO4)2-doped PBI membrane, an MEA fabricated by the CCM method was compared with an MEA made by the CCS method. Under each temperature condition, the peak power density of the CCM-MEA was higher than that of the CCS-MEA. Furthermore, under humidified gas conditions, an enhancement in the peak power densities was observed for both MEAs, which was attributed to the increase in the conductivity of the electrolyte membrane. The CCM-MEA exhibited a peak power density of 647 mW cm-2 at 200 °C, which was ~16% higher than that of the CCS-MEA. Electrochemical impedance spectroscopy results showed that the CCM-MEA had lower ohmic resistance, which implied that it had better contact between the membrane and catalyst layer.

Microclimate stability on the critical zone of a karst hillslope in southwest China: Insights from continuous temperature observations at the air-soil-epikarst interface.

Temperature is an important near-surface microclimate parameter that plays a key role in hydrological, ecological, and biogeochemical functions. However, the spatio-temporal distribution of temperature on the invisible and inaccessible soil-weathered bedrock continuum, wherein hydrothermal processes are most active, remains poorly understood. Temperature dynamics were monitored at 5 min intervals in the air-soil-epikarst (∼3 m) system at different topographical positions of the karst peak-cluster depression in southwest China. The weathering intensity was characterized based on the physicochemical properties of samples collected through drilling. No significant difference was observed in air temperature across slope positions, which was related to the limited distance and elevation resulting in roughly consistent energy input. The control effect of air temperature on the soil-epikarst was weakened with the decrease in elevation (±0.36 to ±0.25 °C). It is attributed to the enhanced temperature regulation capacity of vegetation cover from the up slope (shrub dominant) to down slope (tree dominant) in a relatively uniform energy environment. Temperature stability is clearly distinguished in two adjacent hillslopes that were differentiated by weathering intensity. For every 1 °C change in the ambient temperature, the amplitude of soil-epikasrt temperature variation on the strongly and weakly weathered hillslopes were ±0.28 and ± 0.32 °C, respectively. The response of soil-epikarst temperature to ambient temperature was more sensitive in the wet season (±0.40 °C) than in the dry season (±0.20 °C), which was related to the cooling effect caused by abundant rainfall. The cooling effect was particularly prominent in the preferential flow development area composed of pipeline cracks, which appear in the hillslope with relatively weak weathering intensity. These demonstrate that soil-epikarst temperature responds more gently to the variability of rainfall and ambient temperature on a relatively strong weathered hillslope. Accordingly, this study highlights that the sensitivity of soil-epikarst temperature to climate change is regulated by vegetation and weathering intensity on karst hillslopes in southwest China.

[Spatial variations and the key driving factors of soil losses on dolomite slopes]. / ç™½äº‘å²©å¡åœ°åœŸå£¤æµå¤±ç©ºé—´åˆ†å¸ƒç‰¹å¾åŠå ³é”®å½±å“å› å­.

We selected a typical dolomite slope and set up three micro-plots (projection length was 2 m, width was 1.2 m) on the upper, middle, and lower slopes to analyze the variations of soil losses and the key influencing factors during two hydrological years (2020-2021). The results showed that soil losses at different slope positions on dolomite slopes followed an order of semi-alfisol in lower slopes (386 g·m-2·a-1) > inceptisol in middle slopes (77 g·m-2·a-1) > entisol in upper slopes (48 g·m-2·a-1). Downward along the slope, the positive correlation gradually increased between soil losses and surface soil water content, as well as rainfall, while it gradually decreased with the maximum 30 min rainfall intensity. The meteorological factors affecting soil erosion on the upper, middle and lower slopes were the maximum 30 min rainfall intensity, precipitation, average rainfall intensity and surface soil water content, respectively. Soil erosion processes on upper slopes were mainly driven by raindrop splash erosion and infiltration-excess runoff, while that on lower slopes were mainly driven by saturation-excess runoff. The volume ratio of fine soil in the soil profile was the key factor of soil losses on dolomite slopes, with an explanation rate of 93.7%. The lower slope was the key site of soil erosion in the dolomite slopes. Subsequent rock desertification management should be based on the erosion mechanism of different slope positions, while control measures should be arranged according to local conditions.

Aggregation of Electrochemically Active Conjugated Organic Molecules and Its Impact on Aqueous Organic Redox Flow Batteries.

Molecule aggregation in solution is acknowledged to be universal and can regulate the molecule's physiochemical properties, which however has been rarely investigated in electrochemistry. Herein, an electrochemical method is developed to quantitatively study the aggregation behavior of the target molecule methyl viologen dichloride. It is found that the oxidation state dicationic ions stay discrete, while the singly-reduced state monoradicals yield a concentration-dependent aggregation behavior. As a result, the molecule's energy level and its redox potential can be effectively regulated. This work does not only provide a method to investigate the molecular aggregation, but also demonstrates the feasibility to tune redox flow battery's performance by regulating the aggregation behavior.

Abdominal core training in table tennis players / Treinamento do centro abdominal em jogadores de tênis de mesa / Entrenamiento del núcleo abdominal en jugadores de tenis de mesa

ABSTRACT Introduction The current teaching mode of table tennis in China is satisfactory, but there are still some problems that are the focus of physical education teachers, such as the low efficiency of sports training. Objective Study the effect of abdominal core training on table tennis teaching. Methods Volunteers trained in table tennis at a physical education college were divided into the experimental and control group. Before and after the beginning of the experiment, table tennis students' physical indices and overall physical scores were obtained under a parameterized protocol. Results The overall score of the experimental group resulted from 7.355 (± 1.827) to 9.072 (± 1.992) before training, and the mean difference was 1.2581 points (P < 0.05), indicating a significant difference. The control group score increased from 7.606 (± 1.937) to 7.989 (± 1.440) before training, and the mean difference was 0.1976, P > 0.05, indicating no significant difference. Conclusion Compared with the current way of teaching table tennis, the scheme proposed in this paper showed better sports efficiency and could help students to improve their physical quality and sports ability. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução O atual modo de ensino do tênis de mesa na China é satisfatório, mas ainda existem alguns problemas que são o foco dos professores de educação física, como a baixa eficiência do treinamento esportivo. Objetivo Estudar o efeito do treinamento do centro abdominal no ensino do tênis de mesa. Métodos Voluntários formados em tênis de mesa em uma faculdade de educação física foram divididos em grupo experimental e de controle. Antes e depois do início da experiência, foram obtidos os índices físicos dos alunos de tênis de mesa e a pontuação física geral sob um protocolo parametrizado. Resultados A pontuação geral do grupo experimental resultou em 7,355 (± 1,827) para 9,072 (± 1,992) antes do treinamento, e a diferença média foi de 1,2581 pontos (P < 0,05), indicando uma diferença significativa. A pontuação do grupo de controle aumentou de 7,606 (± 1,937) para 7,989 (± 1,440) antes do treinamento, sendo a diferença média de 0,1976, P > 0,05, indicando que não houve diferença significativa. Conclusão Em comparação com o atual modo de ensino do tênis de mesa, o esquema proposto neste trabalho apresentou melhor eficiência esportiva podendo ajudar os estudantes a melhorar a sua qualidade física e habilidade esportiva. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción El modo de enseñanza actual del tenis de mesa en China es satisfactorio, pero todavía hay algunos problemas que son el centro de atención de los profesores de educación física, como la baja eficiencia del entrenamiento deportivo. Objetivo Estudiar el efecto del entrenamiento del núcleo abdominal en la enseñanza del tenis de mesa. Métodos Los voluntarios entrenados en tenis de mesa en una escuela de educación física se dividieron en grupo experimental y grupo de control. Antes y después del inicio del experimento, se obtuvieron los índices físicos de los alumnos de tenis de mesa y la puntuación física global bajo un protocolo parametrizado. Resultados La puntuación global del grupo experimental pasó de 7,355 (± 1,827) a 9,072 (± 1,992) antes del entrenamiento, y la diferencia media fue de 1,2581 puntos (P < 0,05), lo que indica una diferencia significativa. La puntuación del grupo de control aumentó de 7,606 (± 1,937) a 7,989 (± 1,440) antes del entrenamiento, y la diferencia media fue de 0,1976, P > 0,05, lo que indica que no hubo diferencias significativas. Conclusión En comparación con la forma actual de enseñar el tenis de mesa, el esquema propuesto en este trabajo presentaba una mayor eficacia deportiva y podía ayudar a los alumnos a mejorar su calidad física y su capacidad deportiva. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Enhanced MEA Performance for an Intermediate-Temperature Fuel Cell with a KH5(PO4)2-Doped Polybenzimidazole Membrane.

This work exhibits an effective approach to enhance the performance of membrane-electrode assembly (MEA) with KH5(PO4)2-doped PBI membrane, by adding phosphoric acid (PA) in the catalyst layer (CL). The ohmic resistance and single-cell performance of the MEA, treated with PA, are reduced by ~80% and improved by ~800%, respectively, compared to that of untreated MEA. Based on the MEA pretreated with PA, the influence of humidity and temperature on the resistance and the single-cell performance are investigated. Under humidified gas conditions, the ohmic resistance of MEA is reduced but the charge transfer resistance is slightly increased. Regarding the effect of temperature, the ohmic resistance of MEA becomes lower as the temperature elevates from 140 to 180 °C, but increases at 200 °C. The maximum peak power density presents at 180 °C and 20% RH with 454 mW cm-2. The peak power density is favored with temperature increase from 140 to 180 °C, but decreases with further increase to 200 °C. Moreover, when dry gas conditions are employed, the output performance is unstable, suggesting that humidification is necessary to inhibit degradation for a long-term stability test.

Modulating p-Orbital of Bismuth Nanosheet by Nickel Doping for Electrocatalytic Carbon Dioxide Reduction Reaction.

Electrochemical reduction of CO2 (CO2 RR) to value-added chemicals is an effective way to harvest renewable energy and utilize carbon dioxide. However, the electrocatalysts for CO2 RR suffer from insufficient activity and selectivity due to the limitation of CO2 activation. In this work, a Ni-doped Bi nanosheet (Ni@Bi-NS) electrocatalyst is synthesized for the electrochemical reduction of CO2 to HCOOH. Physicochemical characterization methods are extensively used to investigate the composition and structure of the materials. Electrochemical results reveal that for the production of HCOOH, the obtained Ni@Bi-NS exhibits an equivalent current density of 51.12 mA cm-2 at -1.10 V, which is much higher than the pure Bi-NS (18.00 mA cm-2 at -1.10 V). A high Faradaic efficiency over 92.0 % for HCOOH is achieved in a wide potential range from -0.80 to -1.10 V, and particularly, the highest efficiency of 98.4 % is achieved at -0.90 V. Both experimental and theoretical results reveal that the superior activity and selectivity are attributed to the doping effect of Ni on the Bi nanosheet. The density functional theory calculation reveals that upon doping, the charge is transferred from Ni to the adjacent Bi atoms, which shifts the p-orbital electronic density states towards the Fermi level. The resultant strong orbital hybridization between Bi and the π* orbitals of CO2 facilitates the formation of *OCHO intermediates and favors its activation. This work provides an effective strategy to develop active and selective electrocatalysts for CO2 RR by modulating the electronic density state.

Implication of Retrobulbar and internal carotid artery blood-flow-volume alterations for the pathogenesis of non-arteritic anterior ischemic optic neuropathy.

BACKGROUND: To analyze blood flow volume alteration that involved both retrobulbar artery and internal carotid artery (ICA) in patients with non-arteritic anterior ischemic optic neuropathy (NAION) and to assess their relevance for the pathogenesis of NAION. METHODS: Forty two patients with NAION (unilateral affected) and 42 age-matched controls participated in this study. By head-and-neck computed tomographic angiography (CTA), the diameter of ICA and ophthalmic artery (OA) were measured. By colour Doppler imaging (CDI), the mean blood flow velocity (Vm) and the blood flow volume of ICA and OA were measured or calculated. By optical coherence tomography angiography (OCTA), peripapillary and optic disc vessel density were measured. Data obtained from the affected side of the patients were compared to those of the contralateral healthy side and the control. RESULTS: Compared with the controls and the contralateral healthy side of the patients with NAION, the diameter of ICA, the blood flow volume of ICA and OA, the peripapillary and optic disc vessel density in the affected side decreased significantly (p < 0.05). However, there was no statistical difference in the diameter of OA (p = 0.179, 0.054 respectively), the Vm of OA (p = 0.052, 0.083 respectively), or the Vm of ICA (p = 0.364, 0.938 respectively) between groups. Peripapillary and optic disc vessel density were significantly positive correlated with the blood flow volume in ipsilateral ICA and OA in patients with NAION (all p < 0.01). CONCLUSIONS: The reduction of blood flow volume was more prominent in OA and ICA than decrease of Vm, peripapillary and optic disc vessel density were significantly positive correlated with the blood flow volume of ipsilateral ICA and OA in patients with NAION.

[Soil-epikarst structures and their hydrological characteristics on dolomite slopes in karst region of southwest China]. / 西南喀斯特白云岩坡地土壤-表层岩溶带结构及水文特征.

Epikarst is the core area of karst critical zone, with important hydrologic regulation and storage function. However, the effects of karst development degree on hydrologic characteristics of epikasrt is still unclear. We used geophysical exploration and hydrogeological techniques, combined with the dynamic monitoring of moisture and water levels, to quantify the karst development degrees and their hydrologic characteristics on slope lands. We analyzed the responses of soil-epikarst systems to rainfall. Results showed that geophysical exploration technology could be well applied to the detection of surface-subsurface structures in the karst areas. The average thickness of soil and surface karst zone on the slope was less than 0.63 m and 2.60 m, respectively. The slopes of strong-karstification characterized by high apparent resistivity, well-developed joint fractures, and strong permeability (0.73 m·d-1). Such a result indicated that epikarst could regulate precipitation. The responses of soil moisture had a larger rainfall threshold (>20.50 mm·d-1) and the water level was determined by rainfall amount. In contrast, the slope with weak-karstification had low apparent resistivity and weak permeability (0.07 m·d-1). Moisture and water level were sensitive to rainfall. Karst channels were developed locally at 240-300 cm with a permeability coefficient of up to 432 mm·d-1. Obvious preferential flow was observed in extreme rainfall events on this slope, which could induce flood disaster in the adjacent depression. Our results would provide scientific basis for further research on water resources regulation, management, and eco-hydrology in karst areas of southwest China.

Radical Stabilization of a Tripyridinium-Triazine Molecule Enables Reversible Storage of Multiple Electrons.

A novel organic molecule, 2,4,6-tris[1-(trimethylamonium)propyl-4-pyridiniumyl]-1,3,5-triazine hexachloride, was developed as a reversible six-electron storage electrolyte for use in an aqueous redox flow battery (ARFB). Physicochemical characterization reveals that the molecule evolves from a radical to a biradical and finally to a quinoid structure upon accepting four electrons. Both the diffusion coefficient and the rate constant were sufficiently high to run a flow battery with low concentration and kinetics polarization losses. In a demonstration unit, the assembled flow battery affords a high specific capacity of 33.0 Ah L-1 and a peak power density of 273 mW cm-2 . This work highlights the rational design of electroactive organics that can manipulate multi-electron transfer in a reversible way, which will pave the way to development of energy-dense, manageable and low-cost ARFBs.

Phenylene-Bridged Bispyridinium with High Capacity and Stability for Aqueous Flow Batteries.

A rotating phenyl ring is introduced between the two pyridinium rings, namely, 1,1'-bis[3-(trimethylamonium)propyl]-4,4'-(1,4-phenylene)bispyridinium tetrachloride ((APBPy)Cl4 ), to form a switchable conjugation. In this design, the conjugation is switched "off" in the oxidized state and the two pyridinium rings behave independently during the redox process, yielding a concomitant transfer of two electrons at the same potential and, thus, simplifying the battery management. The conjugation is switched "on" in the reduced state and the charge can be effectively delocalized, lowering the Lewis basicity and improving its chemical stability. By pairing 0.50 m (APBPy)Cl4 with a 2,2,6,6-tetramethylpiperidin-1-yl oxyl derivative as the positive electrolyte, a flow battery delivers a high standard cell voltage of 1.730 V and a high specific capacity of 20.0 Ah L-1 . The battery also shows an exceptionally high energy efficiency of 80.8% and a superior cycling stability at 80 mA cm-2 . This strategy proves itself a great success in engineering viologen as a two-electron storage mediator with high capacity and stability.

Imageology of internal carotid artery siphon in non-arteritic anterior ischaemic optic neuropathy.

AIM: To evaluate whether narrowing of internal carotid artery siphon (ICAS) may increase the risk of developing non-arteritic anterior ischaemic optic neuropathy (NAION). METHODS: Totally 30 consecutive patients who had unilateral NAION and 30 gender-matched control subjects were recruited in the present study. The diameter of ICAS of all the participants were measured using head-and-neck computed tomographic angiography (CTA). Color doppler flow imaging (CDI) was used to measure the haemodynamics parameters of ICAS and short posterior ciliary arteries (SPCAs) in all subjects. Comparison of parameters between the NAION patients and controls as well as between the two sides within the patients were performed. The correlation between the diameter of ICAS and NAION was analyzed. RESULTS: A comparison of parameters between the affected side of the NAION patients and the controls, including the diameter of ICAS, the resistance index (RI) of ICAS, the blood flow velocities of SPCAs and RI of SPCAs, showed significantly difference (P<0.01), while there was no significant difference in terms of the mean blood flow velocity (Vm) of ICAS; Similar results were found while comparing all the measurements of the affected and unaffected side of patients (P for RI of SPCAs <0.05). No marked difference was detected in nearly all parameters except for RI of ICAS and SPCAs between the unaffected side of the NAION patients and the controls (P<0.05). The diameter of ICAS were significantly positive correlated with both peak systolic velocity (PSV) of SPCAs and end diastolic velocity (EDV) of SPCAs in patients with NAION (r=0.514, P<0.01 and r=0.418, P<0.05, respectively). CONCLUSION: Narrowing of ICAS may increase the risk of developing NAION.

Improved stability of ß-CsPbI3 inorganic perovskite using π-conjugated bifunctional surface capped organic cations for high performance photovoltaics.

Multiple-ring naphthalenediammonium is employed for the first time to overcome the intrinsic instability of ß-CsPbI3 perovskite via anchoring the ammonium groups occupying A-site vacancies. It improves charge transport and moisture stability giving out a champion power conversion efficiency of 16.69% for an excellent inorganic perovskite solar cell.