RESUMEN
Graphite exhibits crystal anisotropy, which impedes the mass transfer of ion intercalation and extraction processes in Li-ion batteries. Herein, a dual-shock chemical strategy has been developed to synthesize the carbon anode. This approach comprised two key phases: (1) a thermal shock utilizing ultrahigh temperature (3228 K) can thermodynamically facilitate graphitization; (2) a mechanical shock (21.64 MPa) disrupting the π-π interactions in the aromatic chains of carbon can result in hybrid-structured carbon composed of crystalline and amorphous carbon. The optimized carbon (DSC-200-0.3) demonstrates a capacity of 208.61 mAh/g at a 10C rate, with a significant enhancement comparing with 15 mAh/g of the original graphite. Impressively, it maintains 81.06% capacity even after 3000 charge-discharge cycles. Dynamic process analysis reveals that this superior rate performance is attributed to a larger interlayer spacing facilitating ion transport comparing with the original graphite, disordered amorphous carbon for additional lithium storage sites, and crystallized carbon for enhanced charge transfer. The dual-shock chemical approach offers a cost-effective and efficient method to rapidly produce hybrid-structured carbon anodes, enabling 10C fast charging capabilities in lithium-ion batteries.
RESUMEN
During development, H3K9me3 heterochromatin is dynamically rearranged, silencing repeat elements and protein coding genes to restrict cell identity. Enhancer of Rudimentary Homolog (ERH) is an evolutionarily conserved protein originally characterized in fission yeast and recently shown to be required for H3K9me3 maintenance in human fibroblasts, but its function during development remains unknown. Here, we show that ERH is required for proper segregation of the inner cell mass and trophectoderm cell lineages during mouse development by repressing totipotent and alternative lineage programs. During human embryonic stem cell (hESC) differentiation into germ layer lineages, ERH is crucial for silencing naïve and pluripotency genes, transposable elements, and alternative lineage genes. Strikingly, ERH depletion in somatic cells reverts the H3K9me3 landscape to an hESC state and enables naïve and pluripotency gene and transposable element activation during iPSC reprogramming. Our findings reveal a role for ERH in initiation and maintenance of developmentally established gene repression.
RESUMEN
Nickel-rich layered oxide LiNixCoyMnzO2 (NCM, x + y + z = 1) is the most promising cathode material for high-energy lithium-ion batteries. However, conventional synthesis methods are limited by the slow heating rate, sluggish reaction dynamics, high energy consumption, and long reaction time. To overcome these challenges, we first employed a high-temperature shock (HTS) strategy for fast synthesis of the NCM, and the approaching ultimate reaction rate of solid phase transition is deeply investigated for the first time. In the HTS process, ultrafast average reaction rate of phase transition from Ni0.6Co0.2Mn0.2(OH)2 to Li- containing oxides is 66.7 (% s-1), that is, taking only 1.5 s. An ultrahigh heating rate leads to fast reaction kinetics, which induces the rapid phase transition of NCM cathodes. The HTS-synthesized nickel-rich layered oxides perform good cycling performances (94% for NCM523, 94% for NCM622, and 80% for NCM811 after 200 cycles at 4.3 V). These findings might also assist to pave the way for preparing effectively Ni-rich layered oxides for lithium-ion batteries.
RESUMEN
Despite widely used as a commercial cathode, the anisotropic 1D channel hopping of lithium ions along the [010] direction in LiFePO4 prevents its application in fast charging conditions. Herein, an ultrafast nonequilibrium high-temperature shock technology is employed to controllably introduce the Li-Fe antisite defects and tensile strain into the lattice of LiFePO4. This design makes the study of the effect of the strain field on the performance further extended from the theoretical calculation to the experimental perspective. The existence of Li-Fe antisite defects makes it feasible for Li+ to move from the 4a site of the edge-sharing octahedra across the ab plane to 4c site of corner-sharing octahedra, producing a new diffusion channel different from [010]. Meanwhile, the presence of a tensile strain field reduces the energy barrier of the new 2D diffusion path. In the combination of electrochemical experiments and first-principles calculations, the unique multiscale coupling structure of Li-Fe antisite defects and lattice strain promotes isotropic 2D interchannel Li+ hopping, leading to excellent fast charging performance and cycling stability (high-capacity retention of 84.4% after 2000 cycles at 10 C). The new mechanism of Li+ diffusion kinetics accelerated by multiscale coupling can guide the design of high-rate electrodes.
RESUMEN
Type IV pili (TFP) are known to be functionally related to cell motilities and natural transformation in many bacteria. However, the molecular and ecological functions of the TFP have rarely been reported for photosynthetic cyanobacteria. Here, by labeling pili in model cyanobacterium Synechococcus elongatus PCC 7942 (Syn7942), we have quantitatively characterized the TFP and its driven twitching motility in situ at the single-cell level. We found an oscillating pattern of TFP in accordance with the light and dark periods during light-dark cycles, which is correlated positively to the oscillating pattern of the natural transformation efficiency. We further showed that the internal circadian clock plays an important role in regulating the oscillating pattern of TFP, which is also supported by evidences at the molecular level by tracking the expression of 16 TFP-related genes. This study adds a detailed picture toward the gap between TFP and its relations to circadian regulations in Syn7942.
Asunto(s)
Relojes Circadianos , Synechococcus , Synechococcus/genética , Fimbrias Bacterianas , CabelloRESUMEN
P2-Na2/3Ni1/3Mn2/3O2 cathode materials have garnered significant attention due to their high cationic and anionic redox capacity under high voltage. However, the challenge of structural instability caused by lattice oxygen evolution and P2-O2 phase transition during deep charging persists. A breakthrough is achieved through a simple one-step synthesis of Cr, Mg co-doped P2-NaNMCM, resulting in a bi-functional improvement effect. P2-NaNMCM-0.01 exhibits an impressive capacity retention rate of 82% after 100 cycles at 1 C. In situ X-ray diffraction analysis shows that the "pillar effect" of Mg mitigates the weakening of the electrostatic shielding and effectively suppresses the phase transition of P2-O2 during the charging and discharging process. This successfully averts serious volume expansion linked to the phase transition, as well as enhances the Na+ migration. Simultaneously, in situ Raman spectroscopy and ex situ X-ray photoelectron spectroscopy tests demonstrate that the strong oxygen affinity of Cr forms a robust TMâO bond, effectively restraining lattice oxygen evolution during deep charging. This study pioneers a novel approach to designing and optimizing layered oxide cathode materials for sodium-ion batteries, promising high operating voltage and energy density.
RESUMEN
BACKGROUND/OBJECTIVES: Relationship between dietary intake and sensory sensitivity and intelligence in autism spectrum disorder (ASD) is not well described. This study aims to investigate nutrition status in children with ASD and ID and its association with sensory sensitivity and intelligence. SUBJECTS/METHODS: 84 students (34 ASD and 48 ID) in a special education school were recruited. Dietary intakes were evaluated with 3-day food dairy. Sensory sensitivity was measured using short sensory profile (SSP). Wechsler IQ test were performed. RESULTS: Two out of twenty-four investigated nutrients had an adequate intake rate of over 50%. Four out of ten investigated vitamins had an inadequate intake rate of over 90% and another two over 80%. 75.6% of participants had inadequate energy intake. After adjusting for age, ASD participants had a higher intake of all surveyed nutrients but only the intake of vitamin E and folate were statistically different (p < 0.05) along with a smaller number of inadequate nutrients (p < 0.001). Taste/smell sensitivity, movement sensitivity, underresponsive/seeks sensation, and total sensory sensitivity symptoms severity were slightly higher in ASD group than in ID group (all p < 0.05). After adjusting for IQ and sensory sensitivity score, difference of number of inadequate nutrients between ASD and ID group were not statistically significant (p = 0.193). CONCLUSIONS: Individuals with ASD had better dietary intake but worse sensory sensitivity compared to those with ID. Sensory sensitivity and intelligence are correlated with nutritional status in individuals with neurodevelopmental disorder.
Asunto(s)
Trastorno del Espectro Autista , Discapacidad Intelectual , Niño , Humanos , Trastorno del Espectro Autista/complicaciones , Inteligencia , Estado Nutricional , VitaminasRESUMEN
The design of a highly and photomodulated proton conductor is important for advanced potential applications in chemical sensors and bioionic functions. In this work, a metal-organic framework (MOF; Gd-NO2) with high proton conductivity is synthesized with a photosensitive ligand of 5-nitroisophthalic acid (BDC-NO2), and it provides remote-control photomodulated proton-conducting behavior. The proton conduction of Gd-NO2 reaches 3.66 × 10-2 S cm-1 at 98% relative humidity (RH) and 25 °C, while it decreases by â¼400 times after irradiation with a 355 nm laser. The newly generated and disappearing FT-IR characteristic peaks reveal that this photomodulated process is realized by the photoinduced transformation from BDC-NO2 to 5-nitroso-isophthalic acid (BDC-NO). According to density functional theory, the smaller electronegativity of the -NO group, the longer distance of the hydrogen bond between BDC-NO and H2O molecules, and the lower water adsorption energy of BDC-NO indicate that the irradiated sample possesses a poorer hydrophilicity and has difficulty forming rich hydrogen-bonded networks, which results in the remarkable decrease of proton conductivity.
RESUMEN
As an important protein structure on the surface of bacteria, type â £ pili (TFP) is the sensing and moving organ of bacteria. It plays a variety of roles in bacterial physiology, cell adhesion, host cell invasion, DNA uptake, protein secretion, biofilm formation, cell movement and electron transmission. With the rapid development of research methods, technical equipment and pili visualization tools, increasing number of studies have revealed various functions of pili in cellular activities, which greatly facilitated the microbial single cell research. This review focuses on the pili visualization method and its application in the functional research of TFP, providing ideas for the research and application of TFP in biology, medicine and ecology.
Asunto(s)
Proteínas Bacterianas , Fimbrias Bacterianas , Fimbrias Bacterianas/genética , Fimbrias Bacterianas/metabolismo , Proteínas Bacterianas/genética , Fenómenos Fisiológicos Bacterianos , Adhesión Bacteriana/fisiologíaRESUMEN
Aqueous rechargeable zinc ion batteries (ARZIBs) are ideal for massive and longstanding energy storage applications because of their excellent security and low operation cost. Nevertheless, ARZIBs are subject to the severe corrosion reaction of zinc metal anodes that is derived from the thermodynamic unsteadiness of the zinc anodes in aqueous solution, as well as zinc dendrite growth originating from uncontrolled zinc deposition. Herein, we created a separator by coating a thin piece of polypropylene (PP) with a compound consisting of zinc trifluoromethanesulfonate [Zn(OTf)2] and poly(vinylidene fluoride-hexafluoropropylene (PVDF-HFP). Consequently, the severe corrosion reaction of the zinc metal anodes and the profuse formation of zinc dendrites were effectively mitigated by the novel PP separator, which prolonged the lifetime of the zinc metal anodes. When a zinc metal plating layer was used with preferential (002) crystallographic orientation, the cyclic performance over 1100 h of the symmetrical Znâ¥Zn battery based on the novel separator was steady. Additionally, the Znâ¥MnO2 batteries exhibited an impressive specific capacity and competitive long durability of 75.5% over 500 cycles at a current density of 0.1 A g-1. With this work, we intend to set the standard for designing novel separators in the construction of advanced zinc anodes for high-performance ARZIBs.
RESUMEN
DeePMD-kit is a powerful open-source software package that facilitates molecular dynamics simulations using machine learning potentials known as Deep Potential (DP) models. This package, which was released in 2017, has been widely used in the fields of physics, chemistry, biology, and material science for studying atomistic systems. The current version of DeePMD-kit offers numerous advanced features, such as DeepPot-SE, attention-based and hybrid descriptors, the ability to fit tensile properties, type embedding, model deviation, DP-range correction, DP long range, graphics processing unit support for customized operators, model compression, non-von Neumann molecular dynamics, and improved usability, including documentation, compiled binary packages, graphical user interfaces, and application programming interfaces. This article presents an overview of the current major version of the DeePMD-kit package, highlighting its features and technical details. Additionally, this article presents a comprehensive procedure for conducting molecular dynamics as a representative application, benchmarks the accuracy and efficiency of different models, and discusses ongoing developments.
RESUMEN
Pioneer transcription factors interact with nucleosomes to scan silent, compact chromatin, enabling cooperative events that modulate gene activity. While at a subset of sites pioneer factors access chromatin by assisted loading with other transcription factors, the nucleosome-binding properties of pioneer factors enable them to initiate zygotic genome activation, embryonic development, and cellular reprogramming. To better understand nucleosome targeting in vivo, we assess whether pioneer factors FoxA1 and Sox2 target stable or unstable nucleosomes and find that they target DNase-resistant, stable nucleosomes, whereas HNF4A, a non-nucleosome binding factor, targets open, DNase-sensitive chromatin. Despite FOXA1 and SOX2 targeting similar proportions of DNase-resistant chromatin, using single-molecule tracking, we find that FOXA1 uses lower nucleoplasmic diffusion and longer residence times while SOX2 uses higher nucleoplasmic diffusion and shorter residence times to scan compact chromatin, while HNF4 scans compact chromatin much less efficiently. Thus, pioneer factors target compact chromatin through distinct processes.
Asunto(s)
Cromatina , Factor Nuclear 3-alfa del Hepatocito , Nucleosomas , Factores de Transcripción SOXB1 , Desoxirribonucleasas/metabolismo , Unión Proteica , Factores de Transcripción/metabolismo , Factor Nuclear 3-alfa del Hepatocito/metabolismo , Factores de Transcripción SOXB1/metabolismoRESUMEN
A mild strategy for Co(III)-catalyzed C(sp2)-H cyanation of indoles was developed by using NCBLD as an electrophilic cyanation reagent and 1-butyl-3-acetylimidazole ditrifluoromethylsulfonimide ([BAIM]NTf2) as an environmentally friendly and recyclable solvent, and a series of 2-cyano products were obtained at room temperature. Adopting this strategy, the unnatural nucleotide fragment precursor of Remdesivir, which was a drug for COVID-19, was synthesized through cyano transformation, further proving the practicability of this cyanation method.
RESUMEN
Colloidal nanocrystals (NCs) have shown remarkable promise for optoelectronics, energy harvesting, photonics, and biomedical imaging. In addition to optimizing quantum confinement, the current challenge is to obtain a better understanding of the critical processing steps and their influence on the evolution of structural motifs. Computational simulations and electron microscopy presented in this work show that nanofaceting can occur during nanocrystal synthesis from a Pb-poor environment in a polar solvent. This could explain the curved interfaces and the olivelike-shaped NCs observed experimentally when these conditions are employed. Furthermore, the wettability of the PbS NCs solid film can be further modified via stoichiometry control, which impacts the interface band bending and, therefore, processes such as multiple junction deposition and interparticle epitaxial growth. Our results suggest that nanofaceting in NCs can become an inherent advantage when used to modulate band structures beyond what is traditionally possible in bulk crystals.
RESUMEN
Heterochromatin is defined as a chromosomal domain harboring repressive H3K9me2/3 or H3K27me3 histone modifications and relevant factors that physically compact the chromatin. Heterochromatin can restrict where transcription factors bind, providing a barrier to gene activation and changes in cell identity. While heterochromatin thus helps maintain cell differentiation, it presents a barrier to overcome during efforts to reprogram cells for biomedical purposes. Recent findings have revealed complexity in the composition and regulation of heterochromatin, and shown that transiently disrupting the machinery of heterochromatin can enhance reprogramming. Here, we discuss how heterochromatin is established and maintained during development, and how our growing understanding of the mechanisms regulating H3K9me3 heterochromatin can be leveraged to improve our ability to direct changes in cell identity.
Asunto(s)
Heterocromatina , Histonas , Histonas/metabolismo , Cromatina , Diferenciación Celular , Factores de Transcripción/metabolismoRESUMEN
N-trifluoromethylsuccinimide (NTFS) as a new trifluoromethylation reagent was designed and prepared via Ag-CF3 , and applied to the direct trifluoromethylation of free aniline, and a series of trifluoromethyl products were obtained with good yields. The practicability of the protocol was verified by a gram-level experiment and the synthesis of the antiasthmatic drug Mabuterol. In addition, a possible radical mechanism was proposed and verified by related experiments. The protocol provided a new solution for C-H trifluoromethylation of free anilines.
RESUMEN
The synthesis of cathode materials plays an important role in determining the production efficiency, cost, and performance of lithium-ion batteries. However, conventional synthesis methods always experience a slow heating rate and involve a complicated multistep reaction process and sluggish reaction dynamics, leading to high energy and long time consumption. Herein, a high-temperature shock (HTS) strategy is reported for the ultrafast synthesis of cathode materials in seconds. The HTS process experiences an ultrahigh heating rate, leading to a non-equilibrium reaction and fast reaction kinetics, and avoids high energy and long time consumption. Mainstream cathode materials (such as LiMn2 O4 , LiCoO2 , LiFePO4 , and Li-rich layered oxide/NiO heterostructured material) are successfully synthesized with pure phases, oxygen vacancies, ultrasmall particle sizes, and good electrochemical performance. The HTS process not only provides an efficient synthesis approach for cathode materials, but also can be extended beyond lithium-ion batteries.
RESUMEN
BACKGROUND: Acute myocardial infarction (MI) is considered to be the main cause of congestive heart failure. The aim of this study was to provide an in-depth analysis of athophysiological processes and provide key targets for intervention in the occurrence of acute MI. METHODS: A rat model of MI was established by ligation of left anterior descending branch. Heart tissue, epicardial adipose tissue (EAT) and subcutaneous adipose tissue (SAT) were collected. H9c2 cells were used to explore the mechanism of complement factor D (CFD) regulating cardiomyocyte apoptosis. RESULTS: Myocardial apoptosis were observed in MI rat, and more EAT was found in the MI group in vivo. The conditioned medium prepared by EAT (EAT-CM) significantly reduced the activity of H9c2 cells. The content of CFD in EAT was significantly increased, and CFD promoted cardiomyocyte apoptosis in vitro and CFD-IN1 (a selective inhibitor of CFD) could revised this effect. CFD induced poly ADP-ribosepolymerase-1 (PARP-1) overactivation. Furthermore, the addition of pan-caspase inhibitor Z-VAD in the SAT-CM + CFD group couldn't affect H9c2 cell apoptosis. CFD induced cell apoptosis via PARP-1 activation and PARP-1 inhibitor 3-Aminobenzamide could revise this effect. The injection of CFD-IN1 in MI rat model confirmed that inhibition of CFD activity alleviated cardiomyocytes apoptosis. CONCLUSION: Our findings indicate that EAT mediating cardiomyocyte apoptosis after MI through secretion of CFD and activation of PARP-1 activity.
Asunto(s)
Factor D del Complemento , Infarto del Miocardio , Miocitos Cardíacos , Poli(ADP-Ribosa) Polimerasa-1 , Animales , Ratas , Tejido Adiposo , Apoptosis , Factor D del Complemento/farmacología , Poli(ADP-Ribosa) Polimerasa-1/metabolismoRESUMEN
BACKGROUND: Preoperative diagnosis of appendiceal mucinous neoplasms is challenging, and there are few reports regarding the endosonographic characteristics of these neoplasms. AIM: To provide a retrospective assessment of the imaging features of appendiceal mucinous neoplasms using endoscopic ultrasound (EUS) by curved linear-array echoendoscope. METHODS: A database of all patients with appendiceal mucinous neoplasms who had received EUS examination at our hospital between January 2018 and July 2023 was retrospectively analyzed. The EUS characteristics and patients' clinical data were reviewed. RESULTS: Twenty-two patients were included in the study. The linear-array echoendoscope successfully reached the ileocecal region in every patient. In the endoscopic view, we could observe the protrusion in the appendiceal orifice in all patients. A volcano sign was observed in two patients, and an atypical volcano sign was seen in two patients. EUS showed that all 22 lesions were submucosal cystic hypoechoic lesions with clear boundaries. No wall nodules were observed, but an onion-peeling sign was observed in 17 cases. CONCLUSION: Linear-array echoendoscope is safe to reach the ileocecal region under the guidance of EUS. Image features on endoscopic and echoendosonograhic views could be used to diagnose appendiceal mucinous neoplasms.
RESUMEN
Electrochemical energy storage devices (EESDs) have caused widespread concern, ascribed to the increasing depletion of traditional fossil energy and environmental pollution. In recent years, nickel cobalt bimetallic sulfides have been regarded as the most attractive electrode materials for super-performance EESDs due to their relatively low cost and multiple electrochemical reaction sites. In this work, NiCo-bimetallic sulfide NixCo3-xS4 particles were synthesized in a mixed solvent system with different proportion of Ni and Co salts added. In order to improve the electrochemical performance of optimized Ni2.5Co0.5S4 electrode, the Ni2.5Co0.5S4 particles were annealed at 350 °C for 60 min (denoted as Ni2.5Co0.5S4-350), and the capacity and rate performance of Ni2.5Co0.5S4-350 was greatly improved. An aqueous NiCo-Zn battery was assembled by utilizing Ni2.5Co0.5S4-350 pressed onto Ni form as cathode and commercial Zn sheet as anode. The NiCo-Zn battery based on Ni2.5Co0.5S4-350 cathode electrode delivers a high specific capacity of 232 mAh g-1 at 1 A g-1 and satisfactory cycling performance (65% capacity retention after 1000 repeated cycles at 8 A g-1). The as-assembled NiCo-Zn battery deliver a high specific energy of 394.6 Wh kg-1 and long-term cycling ability. The results suggest that Ni2.5Co0.5S4-350 electrode has possible applications in the field of alkaline aqueous rechargeable electrochemical energy storage devices for supercapacitor and NiCo-Zn battery.