Esophageal squamous dysplasia is believed to be the precursor lesion of esophageal squamous cell carcinoma (ESCC); however, the genetic evolution from dysplasia to ESCC remains poorly understood. ...Here, we applied multi-region whole-exome sequencing to samples from two cohorts, 45 ESCC patients with matched dysplasia and carcinoma samples, and 13 tumor-free patients with only dysplasia samples. Our analysis reveals that dysplasia is heavily mutated and harbors most of the driver events reported in ESCC. Moreover, dysplasia is polyclonal, and remarkable heterogeneity is often observed between tumors and their neighboring dysplasia samples. Notably, copy number alterations are prevalent in dysplasia and persist during the ESCC progression, which is distinct from the development of esophageal adenocarcinoma. The sharp contrast in the prevalence of the 'two-hit' event on TP53 between the two cohorts suggests that the complete inactivation of TP53 is essential in promoting the development of ESCC.The pathogenesis of oesophageal squamous cell carcinoma is a multi-step process but the genetic determinants behind this progression are unknown. Here the authors use multi-region exome sequencing to comprehensively investigate the genetic evolution of precursor dysplastic lesions and untransformed oesophagus.
The average increase in the rate of the energy density of secondary batteries has been about 3% in the past 60 years. Obviously, a great breakthrough is needed in order to increase the energy density ...from the current 210 Wh kg-1 of Li-ion batteries to the ambitious target of 500-700 Wh kg-1 to satisfy application in electrical vehicles. A thermodynamic calculation on the theoretical energy densities of 1172 systems is performed and energy storage mechanisms are discussed, aiming to determine the theoretical and practical limits of storing chemical energy and to screen possible systems. Among all calculated systems, the Li/F2 battery processes the highest energy density and the Li/O2 battery ranks as the second highest, theoretically about ten times higher than current Li-ion batteries. In this paper, energy densities of Li-ion batteries and a comparison of Li, Na, Mg, Al, Zn-based batteries, Li-storage capacities of the electrode materials and conversion reactions for energy storage, in addition to resource and environmental concerns, are analyzed.
Lithium–sulfur (Li–S) batteries are regarded as promising high‐energy‐density energy storage devices. However, the cycling stability of Li–S batteries is restricted by the parasitic reactions between ...Li metal anodes and soluble lithium polysulfides (LiPSs). Encapsulating LiPS electrolyte (EPSE) can efficiently suppress the parasitic reactions but inevitably sacrifices the cathode sulfur redox kinetics. To address the above dilemma, a redox comediation strategy for EPSE is proposed to realize high‐energy‐density and long‐cycling Li–S batteries. Concretely, dimethyl diselenide (DMDSe) is employed as an efficient redox comediator to facilitate the sulfur redox kinetics in Li–S batteries with EPSE. DMDSe enhances the liquid–liquid and liquid–solid conversion kinetics of LiPS in EPSE while maintains the ability to alleviate the anode parasitic reactions from LiPSs. Consequently, a Li–S pouch cell with a high energy density of 359 Wh kg−1 at cell level and stable 37 cycles is realized. This work provides an effective redox comediation strategy for EPSE to simultaneously achieve high energy density and long cycling stability in Li–S batteries and inspires rational integration of multi‐strategies for practical working batteries.
A redox comediation strategy is proposed for promoting the cathode redox kinetics and simultaneously retaining the anode protection capability of lithium–sulfur batteries using encapsulating lithium polysulfide electrolyte. A 1.5 Ah lithium–sulfur pouch cell realizes a high initial energy density of 359 Wh kg−1 and 37 stable cycles following the above strategy.
Practical lithium–sulfur (Li−S) batteries are severely plagued by the instability of solid electrolyte interphase (SEI) formed in routine ether electrolytes. Herein, an electrolyte with ...1,3,5‐trioxane (TO) and 1,2‐dimethoxyethane (DME) as co‐solvents is proposed to construct a high‐mechanical‐stability SEI by enriching organic components in Li−S batteries. The high‐mechanical‐stability SEI works compatibly in Li−S batteries. TO with high polymerization capability can preferentially decompose and form organic‐rich SEI, strengthening mechanical stability of SEI, which mitigates crack and regeneration of SEI and reduces the consumption rate of active Li, Li polysulfides, and electrolytes. Meanwhile, DME ensures high specific capacity of S cathodes. Accordingly, the lifespan of Li−S batteries increases from 75 cycles in routine ether electrolyte to 216 cycles in TO‐based electrolyte. Furthermore, a 417 Wh kg−1 Li−S pouch cell undergoes 20 cycles. This work provides an emerging electrolyte design for practical Li−S batteries.
An emerging electrolyte design, which can construct high‐mechanical‐stability solid electrolyte interphase (SEI) on lithium metal anodes, is proposed for practical lithium–sulfur batteries. High‐mechanical‐stability SEI effectively restricts its fracture and ongoing reactions of electrolytes on lithium metal anodes, which notably improves the stability of practical lithium–sulfur coin and pouch cells.
Long cycling lifespan is a prerequisite for practical lithium–sulfur batteries yet is restricted by side reactions between soluble polysulfides and the lithium‐metal anode. The regulation on ...solvation structure of polysulfides renders encapsulating polysulfides electrolytes (EPSE) as a promising solution to suppress the parasitic reactions. The solvating power of the solvents in the outer solvent shell of lithium polysulfides is critical for the encapsulation effect of EPSE. Herein, 1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropyl ether (HFE) is demonstrated as a superior outer‐shell solvent to construct EPSE. Based on the large steric hindrance of the fluorohydrocarbon chains, the electron‐withdrawing perfluoro segment (CF2 further endows HFE with prominently weak solvating power. The HFE‐EPSE improves the lifespan from 54 to 135 cycles for lithium–sulfur batteries with an ultrathin lithium‐metal anode (50 µm) and high‐areal‐loading sulfur cathode (4.4 mg cm−2). Furthermore, a 334 Wh kg−1 lithium–sulfur pouch cell (2.4 Ah level) with HFE‐EPSE stably undergoes 25 cycles. This work demonstrates the role of weakening solvating power of outer‐shell solvents to construct superior EPSE and inspires the significance of the solvation chemistry of polysulfides to achieve practical lithium–sulfur batteries.
The large steric hindrance of its fluorohydrocarbon chains and the electron‐withdrawing CF2 segments endow 1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropyl ether with prominently weak solvating power and high reduction stability. The weakening solvating power of fluorohydrocarbon solvent leads the formation of encapsulating‐lithium polysulfide electrolyte for lithium–sulfur pouch cells with long cycling lifespan.
Lithium–sulfur (Li–S) batteries promise great potential as high‐energy‐density energy storage devices. However, the parasitic reactions between lithium polysulfides (LiPSs) and Li metal anodes render ...limited cycling lifespan of Li–S batteries. Herein, an organic‐rich solid electrolyte interphase (SEI) is constructed to inhibit the LiPS parasitic reactions and achieve long‐cycling Li–S batteries. Concretely, 1,3,5‐trioxane is introduced as a reactive co‐solvent that decomposes on Li anode surfaces and contributes organic components to the SEI. The as‐constructed organic‐rich SEI effectively inhibits the LiPS parasitic reactions and protects working Li metal anodes. Consequently, the cycling lifespan of Li–S coin cells with 50 µm Li anodes and 4.0 mg cm−2 sulfur cathodes is prolonged from 130 to 300 cycles by the organic‐rich SEI. Furthermore, the organic‐rich SEI enables a 3.0 Ah‐level Li–S pouch cell to achieve a high energy density of 400 Wh kg−1 and stable 26 cycles. This study affords an effective organic‐rich SEI to inhibit the LiPS parasitic reactions and inspires rational SEI design to achieve long‐cycling Li–S batteries.
A robust organic‐rich solid electrolyte interphase (SEI) is constructed to inhibit the lithium polysulfide parasitic reactions and achieve long‐cycling lithium–sulfur batteries. The organic‐rich SEI constructed by the decomposition of 1,3,5‐trioxane effectively protects lithium metal anodes during cycling while the routine SEI induces inhomogeneous lithium deposition and rapid lithium anode failure.
Atomically ordered intermetallic nanoparticles are promising for catalytic applications but are difficult to produce because the high-temperature annealing required for atom ordering inevitably ...accelerates metal sintering that leads to larger crystallites. We prepared platinum intermetallics with an average particle size of <5 nanometers on porous sulfur-doped carbon supports, on which the strong interaction between platinum and sulfur suppresses metal sintering up to 1000°C. We synthesized intermetallic libraries of small nanoparticles consisting of 46 combinations of platinum with 16 other metal elements and used them to study the dependence of electrocatalytic oxygen-reduction reaction activity on alloy composition and platinum skin strain. The intermetallic libraries are highly mass efficient in proton-exchange-membrane fuel cells and could achieve high activities of 1.3 to 1.8 amperes per milligram of platinum at 0.9 volts.
The existence of breast cancer stem cells (BCSCs) is a major reason underlying cancer metastasis and recurrence after chemotherapy and radiotherapy. Targeting BCSCs may ameliorate breast cancer ...relapse and therapy resistance. Here we report that expression of the pseudokinase Tribble 3 (TRIB3) positively associates with breast cancer stemness and progression. Elevated TRIB3 expression supports BCSCs by interacting with AKT to interfere with the FOXO1-AKT interaction and suppress FOXO1 phosphorylation, ubiquitination, and degradation by E3 ligases SKP2 and NEDD4L. The accumulated FOXO1 promotes transcriptional expression of SOX2, a transcriptional factor for cancer stemness, which in turn, activates FOXO1 transcription and forms a positive regulatory loop. Disturbing the TRIB3-AKT interaction suppresses BCSCs by accelerating FOXO1 degradation and reducing SOX2 expression in mouse models of breast cancer. Our study provides insights into breast cancer development and confers a potential therapeutic strategy against TRIB3-overexpressed breast cancer.
The cycle life of high‐energy‐density lithium−sulfur (Li−S) batteries is severely plagued by the incessant parasitic reactions between Li metal anodes and reactive Li polysulfides (LiPSs). ...Encapsulating Li‐polysulfide electrolyte (EPSE) emerges as an effective electrolyte design to mitigate the parasitic reactions kinetically. Nevertheless, the rate performance of Li−S batteries with EPSE is synchronously suppressed. Herein, the sacrifice in rate performance by EPSE is circumvented while mitigating parasitic reactions by employing hexyl methyl ether (HME) as a co‐solvent. The specific capacity of Li−S batteries with HME‐based EPSE is nearly not decreased at 0.1 C compared with conventional ether electrolytes. With an ultrathin Li metal anode (50 μm) and a high‐areal‐loading sulfur cathode (4.4 mgS cm−2), a longer cycle life of 113 cycles was achieved in HME‐based EPSE compared with that of 65 cycles in conventional ether electrolytes at 0.1 C. Furthermore, both high energy density of 387 Wh kg−1 and stable cycle life of 27 cycles were achieved in a Li−S pouch cell (2.7 Ah). This work inspires the feasibility of regulating the solvation structure of LiPSs in EPSE for Li−S batteries with balanced performance.
Hexyl methyl ether (HME) is proposed as a co‐solvent to formulate encapsulating lithium‐polysulfide electrolyte (EPSE). The sacrifice in specific capacity of S cathodes at a high rate in common EPSEs is circumvented in HME‐EPSE while mitigating parasitic reactions of lithium polysulfides with lithium metal anodes. Both high energy density of 387 Wh kg−1 and stable cycle life of 27 cycles were achieved in a lithium−sulfur pouch cell.
Psychological health problems, especially emotional disorders, are common among adolescents. The epidemiology of emotional disorders is greatly influenced by stressful events. This study sought to ...assess the prevalence rate and socio-demographic correlates of depressive and anxiety symptoms among Chinese adolescents affected by the outbreak of COVID-19. We conducted a cross-sectional study among Chinese students aged 12–18 years during the COVID-19 epidemic period. An online survey was used to conduct rapid assessment. A total of 8079 participants were involved in the study. An online survey was used to collect demographic data, assess students’ awareness of COVID-19, and assess depressive and anxiety symptoms with the Patient Health Questionnaire (PHQ-9) and the Generalized Anxiety Disorder (GAD-7) questionnaire, respectively. The prevalence of depressive symptoms, anxiety symptoms, and a combination of depressive and anxiety symptoms was 43.7%, 37.4%, and 31.3%, respectively, among Chinese high school students during the COVID-19 outbreak. Multivariable logistic regression analysis revealed that female gender was the higher risk factor for depressive and anxiety symptoms. In terms of grades, senior high school was a risk factor for depressive and anxiety symptoms; the higher the grade, the greater the prevalence of depressive and anxiety symptoms. Our findings show there is a high prevalence of psychological health problems among adolescents, which are negatively associated with the level of awareness of COVID-19. These findings suggest that the government needs to pay more attention to psychological health among adolescents while combating COVID-19.
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