Reinterpreting the Intercalation-Conversion Mechanism of FeP Anodes in Lithium/Sodium-Ion Batteries from Evolution of the Magnetic Phase.

Batteries with intercalation-conversion-type electrodes tend to achieve high-capacity storage, but the complicated reaction process often suffers from confusing electrochemical mechanisms. Here, we reinterpreted the essential issue about the potential of the conversion reaction and whether there is an intercalation reaction in a lithium/sodium-ion battery (LIB/SIB) with the FeP anode based on the evolution of the magnetic phase. Especially, the ever-present intercalation process in a large voltage range followed by the conversion reaction with extremely low potential was confirmed in FeP LIB, while it is mainly the conversion reaction for the sodium storage mechanism in FeP SIB. The insufficient conversion reaction profoundly limits the actual capacity to the expectedly respectable value. Accordingly, a graphene oxide modification strategy was proposed to increase the reversible capacity of FeP LIB/SIB by 99% and 132%, respectively. The results facilitate the development of anode materials with a high capacity and low operating potential.

Real-time tracking of electron transfer at catalytically active interfaces in lithium-ion batteries.

Transition metals and related compounds are known to exhibit high catalytic activities in various electrochemical reactions thanks to their intriguing electronic structures. What is lesser known is their unique role in storing and transferring electrons in battery electrodes which undergo additional solid-state conversion reactions and exhibit substantially large extra capacities. Here, a full dynamic picture depicting the generation and evolution of electrochemical interfaces in the presence of metallic nanoparticles is revealed in a model CoCO3/Li battery via an in situ magnetometry technique. Beyond the conventional reduction to a Li2CO3/Co mixture under battery operation, further decomposition of Li2CO3 is realized by releasing interfacially stored electrons from its adjacent Co nanoparticles, whose subtle variation in the electronic structure during this charge transfer process has been monitored in real time. The findings in this work may not only inspire future development of advanced electrode materials for next-generation energy storage devices but also open up opportunities in achieving in situ monitoring of important electrocatalytic processes in many energy conversion and storage systems.

Electrochemical interfacial catalysis in Co-based battery electrodes involving spin-polarized electron transfer.

Interfacial catalysis occurs ubiquitously in electrochemical systems, such as batteries, fuel cells, and photocatalytic devices. Frequently, in such a system, the electrode material evolves dynamically at different operating voltages, and this electrochemically driven transformation usually dictates the catalytic reactivity of the material and ultimately the electrochemical performance of the device. Despite the importance of the process, comprehension of the underlying structural and compositional evolutions of the electrode material with direct visualization and quantification is still a significant challenge. In this work, we demonstrate a protocol for studying the dynamic evolution of the electrode material under electrochemical processes by integrating microscopic and spectroscopic analyses, operando magnetometry techniques, and density functional theory calculations. The presented methodology provides a real-time picture of the chemical, physical, and electronic structures of the material and its link to the electrochemical performance. Using Co(OH)2 as a prototype battery electrode and by monitoring the Co metal center under different applied voltages, we show that before a well-known catalytic reaction proceeds, an interfacial storage process occurs at the metallic Co nanoparticles/LiOH interface due to injection of spin-polarized electrons. Subsequently, the metallic Co nanoparticles act as catalytic activation centers and promote LiOH decomposition by transferring these interfacially residing electrons. Most intriguingly, at the LiOH decomposition potential, electronic structure of the metallic Co nanoparticles involving spin-polarized electrons transfer has been shown to exhibit a dynamic variation. This work illustrates a viable approach to access key information inside interfacial catalytic processes and provides useful insights in controlling complex interfaces for wide-ranging electrochemical systems.

Prognostic Value of the Average Lung CT Number in Patients with Acute Paraquat Poisoning.

Objective: The chest computed tomography (CT) examination is an important clinical examination in the diagnosis and monitoring of paraquat- (PQ-) induced lung injury. The aim of this study was to explore the prognostic value of the average lung CT number acquired by quantitative CT techniques in patients with acute paraquat poisoning in the early stages of the disease. Methods: 46 patients who suffered from acute PQ poisoning in the emergency department of the Nanjing Drum Tower Hospital from January 2015 to June 2020 were enrolled in the present study. The patients were divided into survival group (n = 21) and nonsurvival group (n = 25). Clinical data were collected from subjects who met the inclusion criteria, including general information, personal disease history, and laboratory test indicators. The average lung CT numbers of each patient were obtained by quantitative CT techniques. Receiver operating characteristic (ROC) analysis was conducted to assess the prognostic value of average lung CT number in patients with acute paraquat poisoning. Results: The average CT numbers of the middle-lung, lower-lung, and whole lung fields in the nonsurvival group were significantly higher than those of the survival group (p < 0.0001). However, the upper-lung field was not significantly different between the two groups (p = 0.7765). The AUCs of different levels ranged from 0.554 to 0.977, among which the lower-lung field presented the largest AUC of 0.977 (95% CI: 0.943∼1; cut-off value: -702Hu; sensitivity 96%; specificity, 90.5%; YI: 0.865), followed by the whole lung field 0.914 (95% CI: 0.830∼0.999; cut-off value: -727Hu; sensitivity 76%; specificity, 95.2%; YI: 0.712) and the middle-lung field 0.87 (95% CI: 0.768∼0.971; cut-off value: -779Hu; sensitivity 80%; specificity, 85.7%; YI: 0.657). Conclusion: The present study indicated that the average lung CT number could be used to evaluate the relationship between the severity of PQ-induced lung injury and prognosis, especially in the lower-lung field. However, further research is needed to draw a clear conclusion.

Spin state modulation on dual Fe center by adjacent Ni sites enabling the boosted activities and ultra-long stability in Zn-air batteries.

Breakthrough in developing cost-effective Fe-based catalysts with superior oxygen reduction reaction (ORR) activities and ultra-long-term stability for application in Zn-air batteries (ZABs) remain a priority but still full of challenges. Herein, the neighboring NiN4 single-metal-atom and Fe2N5 dual-metal-atoms on the N-doped hollow carbon sphere (Fe/Ni-NHCS) were deliberately constructed as the efficient and robust ORR catalyst for ZABs. Both theory calculations and magnetic measurements demonstrate that the introduction of NiN4 provides a significant role on optimizing the electron spin state of Fe2N5 sites and reducing the energy barrier for the adsorption and conversion of the oxygen-containing intermediates, enabling the Fe/Ni-NHCS with excellent ORR performance and ultralow byproduct HO2- yield (0.5%). Impressively, the ZABs driven by Fe/Ni-NHCS exhibit unprecedented long-term rechargeable stability over 1200 h. This work paves a new venue to manipulate the spin state of active sites for simultaneously achieving superior catalytic activities and ultra-long-term stability in energy conversion technologies.

Space-Charge Control of Magnetism in Ferromagnetic Metals: Coupling Giant Magnitude and Robust Endurance.

Ferromagnetic metals show great prospects in ultralow-power-consumption spintronic devices, due to their high Curie temperature and robust magnetization. However, there is still a lack of reliable solutions for giant and reversible voltage control of magnetism in ferromagnetic metal films. Here, a novel space-charge approach is proposed which allows for achieving a modulation of 30.3 emu/g under 1.3 V in Co/TiO2 multilayer granular films. The robust endurance with more than 5000 cycles is demonstrated. Similar phenomena exist in Ni/TiO2 and Fe/TiO2 multilayer granular films, which shows its universality. The magnetic change of 107% in Ni/TiO2 underlines its potential in a voltage-driven ON-OFF magnetism. Such giant and reversible voltage control of magnetism can be ascribed to space-charge effect at the ferromagnetic metals/TiO2 interfaces, in which spin-polarized electrons are injected into the ferromagnetic metal layer with the adsorption of lithium-ions on the TiO2 surface. These results open the door for a promising method to modulate the magnetization in ferromagnetic metals, paving the way toward the development of ionic-magnetic-electric coupled applications.

Pseudocapacitance-Enhanced Storage Kinetics of 3D Anhydrous Iron (III) Fluoride as a Cathode for Li/Na-Ion Batteries.

Transition metal fluoride (TMF) conversion cathodes, with high energy density, are recognized as promising candidates for next-generation high-energy Li/Na-ion batteries (LIBs/SIBs). Unfortunately, the poor electronic conductivity and detrimental active material dissolution of TMFs seriously limit the performance of TMF-LIBs/SIBs. A variety of FeF3-based composites are designed to improve their electrochemical characteristics. However, the storage mechanism of the conversion-type cathode for Li+ and Na+ co-storage is still unclear. Here, the storage mechanism of honeycomb iron (III) fluoride and carbon (FeF3@C) as a general cathode for LIBs/SIBs is analyzed by kinetics. In addition, the FeF3@C cathode shows high electrochemical performance in a full-cell system. The results show that the honeycomb FeF3@C shows excellent long-term cycle stability in LIBs (208.3 mA h g-1 at 1.0 C after 100 cycles with a capacity retention of 98.1%). As a cathode of SIBs, the rate performance is unexpectedly stable. The kinetic analysis reveals that the FeF3@C cathode exhibit distinct ion-dependent charge storage mechanisms and exceptional long-durability cyclic performance in the storage of Li+/Na+, benefiting from the synergistic contribution of pseudocapacitive and reversible redox behavior. The work deepens the understanding of the conversion-type cathode in Li+/Na+ storage.

Revealing An Intercalation-Conversion-Heterogeneity Hybrid Lithium-Ion Storage Mechanism in Transition Metal Nitrides Electrodes with Jointly Fast Charging Capability and High Energy Output.

The performance of electrode materials depends intensively on the lithium (Li)-ion storage mechanisms correlating ultimately with the Coulombic efficiency, reversible capacity, and morphology variation of electrode material upon cycling. Transition metal nitrides anode materials have exhibited high-energy density and superior rate capability; however, the intrinsic mechanism is largely unexplored and still unclear. Here, a typical 3D porous Fe2 N micro-coral anode is prepared and, an intercalation-conversion-heterogeneity hybrid Li-ion storage mechanism that is beyond the conventional intercalation or conversion reaction is revealed through various characterization techniques and thermodynamic analysis. Interestingly, using advanced in situ magnetometry, the ratio (ca. 24.4%) of the part where conversion reaction occurs to the entire Fe2 N can further be quantified. By rationally constructing a Li-ion capacitor comprising 3D porous Fe2 N micro-corals anode and commercial AC cathode, the hybrid full device delivers a high energy-density (157 Wh kg-1 ) and high power-density (20 000 W kg-1 ), as well as outstanding cycling stability (93.5% capacitance retention after 5000 cycles). This research provides an original and insightful method to confirm the reaction mechanism of material related to transition metals and a fundamental basis for emerging fast charging electrode materials to be efficiently explored for a next-generation battery.

Reacquainting the Electrochemical Conversion Mechanism of FeS2 Sodium-Ion Batteries by Operando Magnetometry.

In spite of the excellent electrochemical performance in lithium-ion batteries (LIBs), transition-metal compounds usually show inferior capacity and cyclability in sodium-ion batteries (SIBs), implying different reaction schemes between these two types of systems. Herein, coupling operando magnetometry with electrochemical measurement, we peformed a comprehensive investigation on the intrinsic relationship between the ion-embedding mechanisms and the electrochemical properties of the typical FeS2/Na (Li) cells. Operando magnetometry together with ex-situ transmission electron microscopy (TEM) measurement reveal that only part of FeS2 is involved in the conversion reaction process, while the unreactive parts form "inactive cores" that lead to the low capacity. Through quantification with Langevin fitting, we further show that the size of the iron grains produced by the conversion reaction are much smaller in SIBs than that in LIBs, which may lead to more serious pulverization, thereby resulting in worse cycle performance. The underlying reason for the above two above phenomena in SIBs is the sluggish kinetics caused by the larger Na-ion radius. Our work paves a new way for the investigation of novel SIB materials with high capacity and long durability.

Two Small Extracellular Vesicle sRNAs Derived From Mycobacterium tuberculosis Serve as Diagnostic Biomarkers for Active Pulmonary Tuberculosis.

The rapid diagnosis of tuberculosis (TB) is of great significance for the control and treatment of TB. However, TB remains a major healthy, social, and economic burden worldwide because of the lack of ideal diagnostic biomarkers. Mycobacterium tuberculosis (M. tuberculosis)-encoded small RNA (sRNA) is a class of regulation small RNA. Several studies have identified M. tuberculosis encoded-sRNAs in the serum/plasm of M. tuberculosis-infected patients. Small extracellular vesicles are small membrane vesicles secreted by many cell types during physiological and pathological conditions. Recent evidence has indicated that most of the nucleic acids in the serum/plasma are packaged in the small extracellular vesicles and could serve as ideal diagnostic biomarkers. In this study, we attempted a novel approach for TB diagnosis: targeting small extracellular vesicles M. tuberculosis encoded sRNA (sRNA) by qRT-PCR. The results showed that M. tuberculosis-encoded ASdes and MTB-miR5 only existed in tuberculosis patients and have the potential to serve as a sensitive and accurate methodology for TB diagnosis.

A Panel of CircRNAs in the Serum Serves as Biomarkers for Mycobacterium tuberculosis Infection.

Tuberculosis (TB), one of the ancient and deadliest diseases, is a chronic immune disorder caused by Mycobacterium tuberculosis (Mtb) infection. Due to the lack of ideal diagnostic and therapeutic markers, TB is still posing a major health, social, and economic burden worldwide. Circular RNA (circRNA), a newly discovered endogenous RNA, is abundant and stable in the cytoplasm and has tissue specificity. More and more studies suggested circRNA is involved in a variety of human pathological and physiological processes. Recently, several studies have confirmed circRNAs not only existed in the serum but also could serve as ideal biomarkers for detecting diseases since the circRNAs have continuous, stable, and covalently closed circular structures and are not easily degraded by nucleases. In this study, we screened the circRNA expression profiles in active TB serum samples and healthy volunteers serum samples by circRNA microarrays. Then, we performed qRT-PCR to verified the dysregulated circRNAs and ROC curve analysis to evaluate the value of circRNAs for TB diagnosis. The results showed circRNA_051239, circRNA_029965, and circRNA_404022 could serve as biomarkers for TB diagnosis.

Temporal Trends in the Risk Factors and Clinical Characteristics of Ischemic Stroke in Young Adults.

OBJECTIVES: This study aimed to analyze the risk factors of ischemic stroke in young adults of different ages; explore the changes in these risk factors with time; analyze the clinical characteristics of ischemic stroke in young adults; and assess how to better prevent ischemic stroke in young adults. METHODS: All patients with ischemic stroke who presented to the Department of Emergency Medicine, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School were enrolled. The data of patients aged 18-50 years were retrospectively evaluated for two periods, January-December 2008 and January-December 2018. Additionally, we collected the data of patients aged 51-90 years with ischemic stroke in the same ward in 2018. The subjects were divided into three groups: ischemic stroke in young people in 2008 ("Youth 2008"), ischemic stroke in young people in 2018 ("Youth 2018"), and ischemic stroke in elderly people in 2018 ("Senior 2018"). Risk factors, clinical characteristics and test indices were recorded and analyzed statistically. RESULTS: The "Youth 2008" group included 28 patients-19 males (67.9%) and 9 females (31.2%) with a male-to-female ratio of 2.11:1. The "Youth 2018" group included 23 patients-20 males (87.0%) and 3 females (13.0%) with a male-to-female ratio of 6.67:1. The "Senior 2018" group included 210 patients-150 males (71.4%) and 60 females (28.6%) with a male-to-female ratio of 2.50:1. The risk factors in "Youth 2018" were higher than those in "Youth 2008" in terms of hypertension, hyperglycemia, and hypercholesterolemia without significant difference. Smoking and hypertrophic cardiomyopathy were significantly increased (P < 0.05) in this population. Smoking, hypercholesterolemia, and hypertrophic cardiomyopathy were more prevalent among the "Youth 2018" group than among the "Senior 2018" group, whereas carotid plaques, hypertension, and atrial fibrillation were less common in the younger group (P < 0.05). There was no significant difference between the younger and older groups in terms of thrombolysis rate, cerebral infarction type, and complications, except pulmonary infections (P < 0.05). CONCLUSIONS: There was no significant change in the main risk factors of ischemic stroke in young adults during the 10-year period. Traditional risk factors-smoking and hypertrophic cardiomyopathy-were still common but with a significantly greater prevalence, whereas carotid plaques, hypertension, and atrial fibrillation had become less common. The clinical characteristics, other than pulmonary infection, were not significantly different between the younger and older patients with ischemic stroke.

The characteristic evolution of soluble microbial product and its effects on membrane fouling during the development of sponge membrane bioreactor coupled with fiber bundle anoxic bio-filter for treating saline wastewater.

Membrane fouling mitigation was observed during the development of novel sponge membrane bioreactor coupled with fiber bundle anoxic bio-filter (AF-MBMBR). Soluble microbial product (SMP) was found to be positively correlated with membrane fouling. To further clarify the mechanism of fouling mitigation, the effects of bio-carriers (sponge and fiber bundles) on characteristics and fouling potential of SMP were investigated. Characterization of SMP implied that as a consequence of employing bio-carriers, tyrosine and tryptophan in SMP significantly decreased, instead relative proportions of humic and fulvic acids increased. Meanwhile, batch filtration tests demonstrated that fouling potential of SMP was significantly alleviated, flux decline caused by filtrating SMP decreased from 84.5% to 60.1%. Further analysis on foulants and filtrate revealed that proteins performed high adhesion propensity on membrane while humic and fulvic acids mainly can pass through the membrane; this finding could well explain the mitigation of SMP fouling potential induced by bio-carriers.

[Neurological prognostic value of gray-white-matter ratio in patients after respiratory and cardiac arrest].

OBJECTIVE: To evaluate the role of gray-white-matter ratio (GWR) on neurological outcome in patients with coma after cardiopulmonary resuscitation (CPR) post-respiratory and cardiac arrest (CA). METHODS: Respiratory and CA patients with restoration of spontaneous circulation (ROSC) and coma after CPR admitted to Nanjing Drum Tower Hospital Clinical Medical College of Nanjing Medical University from February 2013 to June 2016 were enrolled. All patients were subjected to target temperature management (TTM) after CPR, and received cranial CT within 5 days after ROSC. Attenuation (hounsfield units) was measured at special sites (basal ganglia, centrum semiovale), and specific locus (caudate nucleus, put amen, corpus callosum, posterior limb of internal capsule, medial cortex, medial white matter). The GWR was calculated for basal ganglia and cerebrum. Neurological outcome was judged according to the Glasgow-Pittsburgh cerebral performance category (CPC) at 3 months after ICU discharge. CPC 1-3 were divided into good prognosis, CPC 4-5 were divided into poor prognosis. The receiver-operating characteristic (ROC) curve was drawn to evaluate the prognostic value of GWR in patients with respiratory and CA. RESULTS: Forty-three patients were enrolled, including 26 males and 17 females; age (63±15) years old; 14 good prognosis and 29 poor prognosis. Compared with the good prognosis group, the basal ganglia GWR (GWRbg) and the average GWR (GWRav) were significantly lowered in the poor prognosis group (1.064±0.103 vs. 1.163±0.818, 1.068±0.087 vs. 1.128±0.071, both P < 0.05), the centrum semiovale GWR (GWRce) was similar to that in the good prognosis group (1.072±0.077 vs. 1.092±0.075, P > 0.05). It was shown by ROC curve analysis that the GWRbg, GWRav could evaluate the neurological outcomes of patients, but GWRce could not. The area under the ROC curve (AUC) of GWRbg was 0.756 [95% confidence interval (95%CI) = 0.607-0.905, P = 0.007], the cut-off value was 1.13, the sensitivity was 71.4%, and specificity was 69.0%; the AUC of GWRav was 0.701 (95%CI = 0.532-0.869, P = 0.035), the cut-off value was 1.13, the sensitivity was 71.4%, and specificity was 65.5%; the AUC of GWRce was 0.590 (95%CI = 0.405-0.775, P = 0.344). CONCLUSIONS: Respiratory and CA patients receiving TTM with high GWR had favorable neurological outcome. GWR, especially GWRbg could provide help for clinical treatment and prognostic value of survival after CA.

The Influence of Virus Infection on the Extracellular pH of the Host Cell Detected on Cell Membrane.

Influenza virus infection can result in changes in the cellular ion levels at 2-3 h post-infection. More H(+) is produced by glycolysis, and the viral M2 proton channel also plays a role in the capture and release of H(+) during both viral entry and egress. Then the cells might regulate the intracellular pH by increasing the export of H(+) from the intracellular compartment. Increased H(+) export could lead indirectly to increased extracellular acidity. To detect changes in extracellular pH of both virus-infected and uninfected cells, pH sensors were synthesized using polystyrene beads (ϕ1 µm) containing Rhodamine B and Fluorescein isothiocyanate (FITC). The fluorescence intensity of FITC can respond to both pH and temperature. So Rhodamine B was also introduced in the sensor for temperature compensation. Then the pH can be measured after temperature compensation. The sensor was adhered to cell membrane for extracellular pH measurement. The results showed that the multiplication of influenza virus in host cell decreased extracellular pH of the host cell by 0.5-0.6 in 4 h after the virus bound to the cell membrane, compared to that in uninfected cells. Immunostaining revealed the presence of viral PB1 protein in the nucleus of virus-bound cells that exhibited extracellular pH changes, but no PB1 protein are detected in virus-unbound cells where the extracellular pH remained constant.

Genotyping of hepatitis B virus (HBV) by oligonucleotides microarray.

Oligonuleotides (oligo) microarray is a promising method for virus genotyping. In this study, we developed an oligo microarray used for genotyping hepatitis B virus (HBV). It consists of 15 probes targeting HBV genotypes A-G and two genotypes of apes, and one conserved probe selected from the HBV pre-S region. To test a clinical sample, the gene targets of clinical samples were amplified and labelled with Cy5-dCTP in a PCR reaction using primers covering the flanking region of the HBV pre-S gene. Following purification, the labelled PCR products were hybridized to the microarray. In an analysis of 96 HBV patients' serum samples using our developed microarray, we identified 34 genotype B, 60 genotype C and 2 genotypes B/C coinfection samples. Sequencing results of 24 randomly selected samples agreed 100% with microarray data. Geographic distribution of genotypes C and B was also divergent, 95.7% (44/46) of genotype C and 64.0% (32/50) of genotype B samples were collected from Northern and Southern China, respectively. The accuracy of genotyping was confirmed by analyzing DNA sequences of 24 samples. It is demonstrated that low-density oligo microarray can serve as a reliable and time-saving method to HBV genotyping from patient's sera.

[Relationship between core promoter mutation, clinical features and virus replication in HBV carriers].

OBJECTIVE: To elucidate the relationship between HBV core promoter mutation and clinical features as well as its effects on serum e system and viral replication. METHODS: Semi-nested mutation specific PCR (msPCR) was employed for detecting core promoter mutation at nt 1 762-1 764 in 97 patients with HBV infection. RESULTS: The msPCR method was demonstrated to be specific and reliable for the mutation detection by sequencing the PCR products. The detection ratio of the mutation in patients with acute hepatitis, mild, moderate and severe chronic hepatitis and liver cirrhosis was 2/5, 7/43, 10/31, 1/3 and 7/15, respectively. The detection rate of the mutation in liver cirrhosis was significantly higher than that in light chronic hepatitis (P < 0.025). In 92 patients with chronic HBV infection, HBeAg positive rate in wild (25/92), mutant (42/92) and mixed (25/92) strain infection was 80.0%, 56.0% and 64.3%, HBV DNA level was (4.4 +/- 8.5) x 10(8), (1.1 +/- 1.6) x 10(9) and (1.4 +/- 1.8) x 10(9) copies/ml, the rate of abnormal ALT was 44.0%, 52.0% and 42.6%; ALT level was (58.6 +/- 79.0), (57.1 +/- 75.2) and (62.6 +/- 90.3) IU/L, respectively (P > 0.05). CONCLUSIONS: The msPCR method for detecting core promoter mutation at nt 1 762-1 764 is specific and reliable. Core promoter mutation is associated with the severity of liver disease, but neither related to the status of e system in serum nor to the virus replication.