Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 147
Filtrar
1.
J Am Chem Soc ; 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38754363

RESUMO

Lithium-sulfur (Li-S) batteries are highly considered as next-generation energy storage techniques. Weakly solvating electrolyte with low lithium polysulfide (LiPS) solvating power promises Li anode protection and improved cycling stability. However, the cathodic LiPS kinetics is inevitably deteriorated, resulting in severe cathodic polarization and limited energy density. Herein, the LiPS kinetic degradation mechanism in weakly solvating electrolytes is disclosed to construct high-energy-density Li-S batteries. Activation polarization instead of concentration or ohmic polarization is identified as the dominant kinetic limitation, which originates from higher charge-transfer activation energy and a changed rate-determining step. To solve the kinetic issue, a titanium nitride (TiN) electrocatalyst is introduced and corresponding Li-S batteries exhibit reduced polarization, prolonged cycling lifespan, and high actual energy density of 381 Wh kg-1 in 2.5 Ah-level pouch cells. This work clarifies the LiPS reaction mechanism in protective weakly solvating electrolytes and highlights the electrocatalytic regulation strategy toward high-energy-density and long-cycling Li-S batteries.

2.
ACS Nano ; 18(13): 9713-9735, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38507590

RESUMO

Cancer-associated fibroblasts (CAFs) assist in breast cancer (BRCA) invasion and immune resistance by overproduction of extracellular matrix (ECM). Herein, we develop FPC@S, a photodynamic immunomodulator that targets the ECM, to improve the photodynamic immunotherapy for fibrotic BRCA. FPC@S combines a tumor ECM-targeting peptide, a photosensitizer (protoporphyrin IX) and an antifibrotic drug (SIS3). After anchoring to the ECM, FPC@S causes ECM remodeling and BRCA cell death by generating reactive oxygen species (ROS) in situ. Interestingly, the ROS-mediated ECM remodeling can normalize the tumor blood vessel to improve hypoxia and in turn facilitate more ROS production. Besides, upon the acidic tumor microenvironment, FPC@S will release SIS3 for reprograming CAFs to reduce their activity but not kill them, thus inhibiting fibrosis while preventing BRCA metastasis. The natural physical barrier formed by the dense ECM is consequently eliminated in fibrotic BRCA, allowing the drugs and immune cells to penetrate deep into tumors and have better efficacy. Furthermore, FPC@S can stimulate the immune system and effectively suppress primary, distant and metastatic tumors by combining with immune checkpoint blockade therapy. This study provides different insights for the development of fibrotic tumor targeted delivery systems and exploration of synergistic immunotherapeutic mechanisms against aggressive BRCA.


Assuntos
Neoplasias da Mama , Fibroblastos Associados a Câncer , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Fibroblastos Associados a Câncer/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Matriz Extracelular/metabolismo , Imunoterapia , Fibrose , Microambiente Tumoral
3.
Nature ; 627(8002): 42-43, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38418722
4.
Acc Chem Res ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38319810

RESUMO

ConspectusLithium-sulfur (Li-S) batteries have attracted worldwide attention as promising next-generation rechargeable batteries due to their high theoretical energy density of 2600 Wh kg-1. The actual energy density of Li-S batteries at the pouch cell level has significantly exceeded that of state-of-the-art Li-ion batteries. However, the overall performances of Li-S batteries under practical working conditions are limited by the sluggish conversion kinetics of the sulfur cathodes. To overcome the above challenge, various kinetic promotion strategies have been proposed to accelerate the multiphase and multi-electron cathodic redox reactions between sulfur, lithium polysulfides (LiPSs), and lithium sulfide. Nowadays, kinetic promoters have been massively employed in sulfur cathodes to achieve Li-S batteries with high energy densities, high rates, and long lifespans. A comprehensive and timely summary of cutting-edge kinetic promoters for sulfur cathodes is of great essence to afford an in-depth understanding of the unique Li-S electrochemistry.In this Account, we outline the recent efforts on the design of sulfur cathode kinetic promoters for advanced Li-S batteries. The latest progress is discussed in detail regarding heterogeneous, homogeneous, and semi-immobilized kinetic promoters. Heterogeneous promoters, representatively known as electrocatalysts, function mainly by reducing the energy barriers of the interfacial electrochemical reactions. The working mechanism, activity regulation strategies, and reconstitution/deactivation processes of the heterogeneous promoters are reviewed to provide guiding principles for rational design. In comparison, homogeneous promoters are able to fully contact with the reaction interfaces and regulate the electron/ion-inaccessible reactants in working Li-S batteries. Redox mediators and redox comediators are typical homogeneous promoters. The former establishes extra chemical reaction pathways to circumvent the originally sluggish steps and boost the overall kinetics, while the latter fundamentally modifies the LiPS molecules to enhance their redox kinetics. For semi-immobilized promoters, the active units are generally anchored on the cathode substrate through flexible chains with mobile characteristics. Such a design endows the promoter with both heterogeneous and homogeneous characteristics to comprehensively regulate the multiphase sulfur redox reactions involving both mobile and immobile reactants.Overall, this Account summarizes the fundamental electrochemistry, design principles, and practical promotion effects of the various kinetic promoters used for the sulfur cathodes in Li-S batteries. We believe that this Account will provide an in-depth and cutting-edge understanding of the unique sulfur electrochemistry, thereby providing guidance for further development of high-performance Li-S batteries and analogous rechargeable battery systems.

5.
Medicine (Baltimore) ; 103(4): e36653, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38277544

RESUMO

BACKGROUND: Previous clinical trials have reported that acupoint catgut embedding (ACE) is a useful modality for weight loss. However, no study has specifically investigated the effectiveness and safety of comparing verum and sham ACE in adults with obesity. Thus, this study aimed to evaluate the effectiveness and safety of comparing verum and sham ACE in obese adults. METHODS: A comprehensive literature search was conducted in the electronic databases of PUBMED, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang, China Science and Technology Journal Database, and China Biomedical Literature Service System from inception to April 1, 2022. Randomized clinical trials that focused on evaluating the effectiveness of comparing verum and sham ACE in adults with obesity were included. The primary outcomes included reduction in body weight, body mass index, hip circumference, and waist circumference. The secondary outcomes consisted of a decrease in body fat percentage and the occurrence rate of adverse events. The methodological quality of the included randomized clinical trials was evaluated using the Cochrane Risk-of-bias tool. Statistical analysis was performed using RevMan 5.4 software. RESULTS: Six trials involving 679 adults with obesity were included in this study and entered in the data analysis of systematic review and meta-analysis. Results of the meta-analysis revealed significant reduction in body weight (mean difference [MD] = -1.68, 95% confidence intervals (CI) [-2.34, -1.01], I2 = 51%, P < .001), body mass index (MD = -0.51, 95% CI [-0.81, -0.21], I2 = 74%, P < .001), hip circumference (MD = -1.11, 95% CI [-1.67, -0.55], I2 = 0%, P < .001), waist circumference (MD = -2.42, 95% CI [-3.38, -1.45], I2 = 68%, P < .001), and decrease in body fat percentage (MD = -0.83, 95% CI [-1.30, -0.36], I2 = 16%, P < .001) in comparing verum and sham ACE. However, no significant difference was identified in AEs (odds ratio = 1.53, 95% CI [0.80, 2.95], I2 = 0%, P = .20) between the 2 groups. CONCLUSION: ACE is effective in the treatment of obesity in adults with safety profile. Further studies with higher quality and larger sample size are warranted to confirm the current findings.


Assuntos
Pontos de Acupuntura , Categute , Adulto , Humanos , Categute/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Obesidade/tratamento farmacológico , Peso Corporal
6.
Fitoterapia ; 174: 105841, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38296170

RESUMO

Prunella vulgaris (PV) is a medicine and food homologous plant, but its quality evaluation seldom relies on the polysaccharides (PVPs). In this work, we established the multi-level fingerprinting and in vitro anti-inflammatory evaluation approaches to characterize and compare the polysaccharides of P. vulgaris collected from the major production regions in China. PVPs prepared from 22 batches of samples gave the content variation of 5.76-24.524 mg/g, but displayed high similarity in the molecular weight distribution. Hydrolyzed oligosaccharides with degrees of polymerization 2-14 were characterized with different numbers of pentose and hexose by HILIC-MS. The tested 22 batches of oligosaccharides exhibited visible differences in peak abundance, which failed to corelate to their production regions. All the PVPs contained Gal, Xyl, and Ara, as the main monosaccharides. Eleven batches among the tested PVPs showed the significant inhibitory effects on NO production on LPS-induced RAW264.7 cells at 10 µg/mL, but the exerted efficacy did not exhibit correlation with the production regions. Conclusively, we, for the first time, investigated the chemical features of PVPs at three levels, and assessed the chemical and anti-inflammatory variations among the different regions of P. vulgaris samples.


Assuntos
Prunella , Prunella/química , Estrutura Molecular , Polissacarídeos/farmacologia , Polissacarídeos/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Oligossacarídeos
7.
Angew Chem Int Ed Engl ; 63(10): e202318785, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38226740

RESUMO

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.

8.
J Pharm Biomed Anal ; 239: 115911, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38091818

RESUMO

Polygonatum odoratum (Yu-Zhu) can be utilized to treat the digestive and respiratory illness. Previous studies have revealed that the underlying therapeutic mechanism of P. odoratum polysaccharides (POPs) is associated with remodeling the gut microbiota. However, POPs in terms of the chemical composition and fermentation activities have been understudied. Here we developed the three-level fingerprinting approaches to characterize the structures of POPs and probed into the beneficial effects on promoting the growth and fermentation of Lactobacillus johnsonii. POPs were prepared by water decoction followed by alcohol sedimentation, while trifluoroacetic acid under different conditions to prepare the hydrolyzed oligosaccharides and monosaccharides. POPs exhibited three main molecular distribution of 601-620 kDa, 4.12-6.09 kDa, and 3.57-6.02 kDa. Hydrolyzed oligosaccharides with degree of polymerization (DP) 2-13 got primarily characterized by analyzing the rich fragmentation information obtained by hydrophilic interaction chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (HILIC/IM-QTOF-MS). Amongst them, the DP5 oligosaccharide was characterized as 1,6,6-kestopentaose. The molecular ratio of Fru: Ara: Glc: Gal: Xyl was 87.72: 0.30: 11.56: 0.19: 0.23. In vitro fermentation demonstrated that 4.5 mg/mL of POPs could significantly promote the growth of L. johnsonii. Co-cultivated with 4.5 mg/mL of POPs, L. johnsonii exhibited stronger antimicrobial activity against Klebsiella pneumoniae. The concentrations of short-chain fatty acids in the POPs-lactobacilli fermented products, including acetic acid, isobutyric acid, and isovaleric acid, were increased. Conclusively, POPs represent the promising prebiotic candidate to facilitate lactobacilli, which is associated with exerting the health benefits.


Assuntos
Microbioma Gastrointestinal , Lactobacillus johnsonii , Polygonatum , Polygonatum/química , Polissacarídeos/farmacologia , Polissacarídeos/química , Oligossacarídeos , Lactobacillus
9.
Adv Mater ; 36(3): e2307768, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37852012

RESUMO

All-solid-state lithium (Li) metal batteries (ASSLMBs) employing sulfide solid electrolytes have attracted increasing attention owing to superior safety and high energy density. However, the instability of sulfide electrolytes against Li metal induces the formation of two types of incompetent interphases, solid electrolyte interphase (SEI) and mixed conducting interphase (MCI), which significantly blocks rapid Li-ion transport and induces uneven Li deposition and continuous interface degradation. In this contribution, a dynamically stable mixed conducting interphase (S-MCI) is proposed by in situ stress self-limiting reaction to achieve the compatibility of Li metal with composite sulfide electrolytes (Li6 PS5 Cl (LPSCl) and Li10 GeP2 S12 (LGPS)). The rational design of composite electrolytes utilizes the expansion stress induced by the electrolyte decomposition to in turn constrain the further decomposition of LGPS. Consequently, the S-MCI inherits the high dynamical stability of LPSCl-derived SEI and the lithiophilic affinity of Li-Ge alloy in LGPS-derived MCI. The Li||Li symmetric cells with the protection of S-MCI can operate stably for 1500 h at 0.5 mA cm-2 and 0.5 mAh cm-2 . The Li||NCM622 full cells present stable cycling for 100 cycles at 0.1 C with a high-capacity retention of 93.7%. This work sheds fresh insight into constructing electrochemically stable interphase for high-performance ASSLMBs.

10.
Adv Mater ; 36(1): e2307370, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37684038

RESUMO

Severe dendrite growth and high-level activity of the lithium metal anode lead to a short life span and poor safety, seriously hindering the practical applications of lithium metal batteries. With a trisalt electrolyte design, an F-/N-containing inorganics-rich solid electrolyte interphase on a lithium anode is constructed, which is electrochemically and thermally stable over long-term cycles and safety abuse conditions. As a result, its Coulombic efficiency can be maintained over 98.98% for 400 cycles. An 85.0% capacity can be retained for coin-type full cells with a 3.14 mAh cm-2 LiNi0.5 Co0.2 Mn0.3 O2 cathode after 200 cycles and 1.0 Ah pouch-type full cells with a 4.0 mAh cm-2 cathode after 72 cycles. During the thermal runaway tests of a cycled 1.0 Ah pouch cell, the onset and triggering temperatures were increased from 70.8 °C and 117.4 °C to 100.6 °C and 153.1 °C, respectively, indicating a greatly enhanced safety performance. This work gives novel insights into electrolyte and interface design, potentially paving the way for high-energy-density, long-life-span, and thermally safe lithium metal batteries.

11.
Adv Mater ; 36(14): e2310738, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38054396

RESUMO

Li-rich Mn-based (LRMO) cathode materials have attracted widespread attention due to their high specific capacity, energy density, and cost-effectiveness. However, challenges such as poor cycling stability, voltage deca,y and oxygen escape limit their commercial application in liquid Li-ion batteries. Consequently, there is a growing interest in the development of safe and resilient all-solid-state batteries (ASSBs), driven by their remarkable safety features and superior energy density. ASSBs based on LRMO cathodes offer distinct advantages over conventional liquid Li-ion batteries, including long-term cycle stability, thermal and wider electrochemical windows stability, as well as the prevention of transition metal dissolution. This review aims to recapitulate the challenges and fundamental understanding associated with the application of LRMO cathodes in ASSBs. Additionally, it proposes the mechanisms of interfacial mechanical and chemical instability, introduces noteworthy strategies to enhance oxygen redox reversibility, enhances high-voltage interfacial stability, and optimizes Li+ transfer kinetics. Furthermore, it suggests potential research approaches to facilitate the large-scale implementation of LRMO cathodes in ASSBs.

12.
J Ethnopharmacol ; 321: 117540, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38056534

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Chimonanthus nitens Oliv. Leaf Granule (COG) is a commonly used clinical preparation of traditional Chinese medicine for the treatment of cold, but there are folk reports that it can treat diarrhea and other gastrointestinal diseases. Therefore, the mechanism of COG in the treatment of ulcerative colitis with diarrhea as the main symptom needs to be studied. AIM OF THE STUDY: Combined network pharmacology and experimental validation to explore the mechanism of COG in the treatment of ulcerative colitis. MATERIALS AND METHODS: First, the main components of COG were characterized by liquid chromatography-mass spectrometry (LC-MS); subsequently, a network pharmacology approach was used to screen the effective chemical components and action targets of COG to construct a target network of COG for the treatment of ulcerative colitis (UC). The protein-protein interaction network (PPI) and literature reports were combined to identify the potential targets of COG for the treatment of UC. Finally, the predicted results of network pharmacology were validated by animal and cellular experiments. RESULTS: 19 components of COG were characterized by LC-MS, among which 10 bioactive components could act on 377 potential targets of UC. Key therapeutic targets were collected, including SRC, HSP90AA1, PIK3RI, MAPK1 and ESR1. KEGG results are enriched in pathways related to oxidative stress. Molecular docking analysis showed good binding activity of main components and target genes. Animal experiments showed that COG significantly relieved the colitis symptoms in mice, regulated the Treg/Th17 balance, and promoted the secretion of IL-10 and IL-4, along with the inhibition of IL-1ß and TNF-α. Additionally, COG reduced the apoptosis of colon epithelial cells, and significantly improved the levels of SOD, MAO, GSH-px, and inhibited MDA, iNOS, eNOS in colon. Also, it increased the expression of tight junction proteins such as ZO-1, Claudin1, Occludin and E-cadherin. In vitro experiments, COG inhibited the oxidative stress and inflammatory injury of HCT116 cells induced by LPS. CONCLUSIONS: Combining network pharmacology and in vitro and in vivo experiments, COG was verified to have a good protective effect in UC, which may be related to enhancing antioxidation in colon tissues.


Assuntos
Calycanthaceae , Colite Ulcerativa , Colite , Medicamentos de Ervas Chinesas , Animais , Camundongos , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Simulação de Acoplamento Molecular , Farmacologia em Rede , Diarreia , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Sulfato de Dextrana
13.
ACS Appl Mater Interfaces ; 15(51): 59165-59174, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38100370

RESUMO

Immunotherapy is known to be a promising strategy in the clinical treatment of malignant tumors, but it has received generally low response rates in various tumors because of the poor immunogenicity and multiple immunosuppressive microenvironments. A self-delivery photodynamic re-educator, denoted as CCXB, is synthesized through the self-assembly of chlorine e6 (Ce6) and celecoxib (CXB). As a carrier-free nanomedicine, CCXB shows a high drug loading rate, improved water stability, superior cellular uptake, and tumor accumulation capability. In comparison with free Ce6, CCXB triggers much stronger photodynamic therapy (PDT) to reduce the proliferation of breast cancer cells and activates robust immune responses via the induction of immunogenic cell death (ICD). Better yet, CXB-mediated cyclooxygenase 2 (COX-2) inhibition can decrease the level of synthesis of prostaglandin E2 (PGE2) to further improve immunosuppressive microenvironments. With the increase of cytotoxic T lymphocytes (CTLs) and decrease of regulatory T cells (Tregs) in tumor, in vivo antitumor immunity is significantly amplified to inhibit the metastasis of breast cancer. This study sheds light on developing drug codelivery systems with collaborative mechanisms for immunotherapy of metastatic tumors.


Assuntos
Neoplasias da Mama , Nanopartículas , Fotoquimioterapia , Humanos , Feminino , Morte Celular Imunogênica , Neoplasias da Mama/patologia , Imunoterapia , Linfócitos T Citotóxicos , Imunossupressores/farmacologia , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes/farmacologia , Microambiente Tumoral
14.
World J Gastroenterol ; 29(36): 5226-5239, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37901446

RESUMO

BACKGROUND: Restoration of immune homeostasis by targeting the balance between memory T helper (mTh) cells and memory follicular T helper (mTfh) cells is a potential therapeutic strategy against ulcerative colitis (UC). Because of its anti-inflammatory and immunomodulatory properties, curcumin (Cur) is a promising drug for UC treatment. However, fewer studies have demonstrated whether Cur can modulate the mTh/mTfh subset balance in mice with colitis. AIM: To explore the potential mechanism underlying Cur-mediated alleviation of colitis induced by dextran sulfate sodium (DSS) in mice by regulating the mTh and mTfh immune homeostasis. METHODS: Balb/c mice were administered 3% and 2% DSS to establish the UC model and treated with Cur (200 mg/kg/d) by gavage on days 11-17. On the 18th d, all mice were anesthetized and euthanized, and the colonic length, colonic weight, and colonic weight index were evaluated. Histomorphological changes in the mouse colon were observed through hematoxylin-eosin staining. Levels of Th/mTh and Tfh/mTfh cell subsets in the spleen were detected through flow cytometry. Western blotting was performed to detect SOCS-1, SOCS-3, STAT3, p-STAT3, JAK1, p-JAK1, and NF-κB p65 protein expression levels in colon tissues. RESULTS: Cur effectively mitigates DSS-induced colitis, facilitates the restoration of mouse weight and colonic length, and diminishes the colonic weight and colonic weight index. Simultaneously, it hinders ulcer development and inflammatory cell infiltration in the colonic mucous membrane. While the percentage of Th1, mTh1, Th7, mTh7, Th17, mTh17, Tfh1, mTfh1, Tfh7, mTfh7, Tfh17, and mTfh17 cells decreased after Cur treatment of the mice for 7 d, and the frequency of mTh10, Th10, mTfh10, and Tfh10 cells in the mouse spleen increased. Further studies revealed that Cur administration prominently decreased the SOCS-1, SOCS-3, STAT3, p-STAT3, JAK1, p-JAK1, and NF-κB p65 protein expression levels in the colon tissue. CONCLUSION: Cur regulated the mTh/mTfh cell homeostasis to reduce DSS-induced colonic pathological damage, potentially by suppressing the JAK1/STAT3/SOCS signaling pathway.


Assuntos
Colite Ulcerativa , Colite , Curcumina , Animais , Camundongos , Sulfato de Dextrana/toxicidade , Curcumina/farmacologia , Curcumina/uso terapêutico , NF-kappa B/metabolismo , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colo/patologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL
15.
Adv Mater ; 35(42): e2301881, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37718507

RESUMO

The Li-plating behavior of Li-ion batteries under fast-charging conditions is elusive due to a lack of reliable indicators of the Li-plating onset. In this work, the relaxation time constant of the charge-transfer process (τCT ) is proposed to be promising for the determination of Li-plating onset. A novel pulse/relaxation test method enables rapid access to the τCT of the graphite anode during battery operation, applicable to both half and full batteries. The diagnosis of Li plating at varying temperatures and charging rates enriches the cognition of Li-plating behaviors. Li plating at low temperatures and high charging rates can be avoided because of the battery voltage limitations. Nevertheless, after the onset, severe Li plating evolves rapidly under harsh charging conditions, while the Li-plating process under benign charging conditions is accompanied by a simultaneous Li-intercalation process. The quantitative estimates indicate that Li plating at high temperatures/high charging rates leads to more irreversible capacity losses. This facile method with rational scientific principles can provide inspiration for exploring the safe boundaries of Li-ion batteries.

16.
Int J Biol Macromol ; 253(Pt 3): 126994, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37730001

RESUMO

Ginseng is rich of polysaccharides, however, the evidence supporting polysaccharides to distinguish various ginseng species is rarely reported. Focusing on six root ginseng (e.g., Panax ginseng-PG, P. quinquefolius-PQ, P. notoginseng-PN, red ginseng-RG, P. japonicus-PJ, and P. japonicus var. major-PJM), the contained non-starch polysaccharides (NPs) were structurally characterized and compared by both the chemical and biological evaluation. Holistic fingerprinting at three levels (the NPs and the acid hydrolysates involving oligosaccharides and monosaccharides) utilized various chromatography methods, and the treatment of H9c2 cells with the NPs by OGD and H2O2-induced injury models was used to assess the protective effect. NPs from six Panax herbal medicines occupied about 20 % of the total polysaccharides, which were of the highest content in RG and the lowest in PN. NPs from six ginseng exhibited weak differentiations in the molecular weight distribution, while marker oligosaccharides were found to distinguish PN and RG from the others. Glc and GalA were more abundant in the NPs for PG and RG, respectively. NPs from PQ (100/200 µg/mL) showed significant cardiomyocyte protection effect by regulating the mitochondrial functions. This work further testifies the role of polysaccharides in quality control of herbal medicine, with new markers discovered beneficial to distinguish the ginseng.


Assuntos
Panax , Plantas Medicinais , Miócitos Cardíacos , Peróxido de Hidrogênio , Panax/química , Extratos Vegetais/química , Polissacarídeos/farmacologia , Polissacarídeos/química , Oligossacarídeos
17.
J Am Chem Soc ; 145(30): 16449-16457, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37427442

RESUMO

Lithium-sulfur (Li-S) batteries afford great promise on achieving practical high energy density beyond lithium-ion batteries. Lean-electrolyte conditions constitute the prerequisite for achieving high-energy-density Li-S batteries but inevitably deteriorates battery performances, especially the sulfur cathode kinetics. Herein, the polarizations of the sulfur cathode are systematically decoupled to identify the key kinetic limiting factor in lean-electrolyte Li-S batteries. Concretely, an electrochemical impedance spectroscopy combined galvanostatic intermittent titration technique method is developed to decouple the cathodic polarizations into activation, concentration, and ohmic parts. Therein, activation polarization during lithium sulfide nucleation emerges as the dominant polarization as the electrolyte-to-sulfur ratio (E/S ratio) decreases, and the sluggish interfacial charge transfer kinetics is identified as the main reason for degraded cell performances under lean-electrolyte conditions. Accordingly, a lithium bis(fluorosulfonyl)imide electrolyte is proposed to decrease activation polarization, and Li-S batteries adopting this electrolyte provide a discharge capacity of 985 mAh g-1 under a low E/S ratio of 4 µL mg-1 at 0.2 C. This work identifies the key kinetic limiting factor of lean-electrolyte Li-S batteries and provides guidance on designing rational promotion strategies to achieve advanced Li-S batteries.

18.
Chem Commun (Camb) ; 59(61): 9320-9335, 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37440172

RESUMO

As a class of promising cathodes in the field of large-scale power storage systems especially for alkali-metal-ion batteries (MIBs), Prussian blue (PB) and its analogues (PBAs) have received wide research attention due to their open framework, high theoretical specific capacity, and simple synthesis method. For large-scale applications, cathode materials with low-cost and long cycle life are preferred. However, only a few of the review papers have concentrated on the detailed analysis of low-cost PBAs, including Fe-based and Mn-based PBAs, which also show excellent electrochemical performance. This review aims to first provide an all-sided understanding of low-cost PBAs in terms of their application and recent progress in MIBs. Then, the major challenges such as inferior electrochemical properties of low-cost PBAs are discussed. Meanwhile, we provide feasible strategies to prepare PBA electrodes with advanced electrochemical performance. Finally, we present some personal perspectives and guidance for future research, aiming to narrow the gap between laboratory investigation and practical application.

19.
Angew Chem Int Ed Engl ; 62(42): e202306889, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37442815

RESUMO

The stability of high-energy-density lithium metal batteries depends on the uniformity of solid electrolyte interphase (SEI) on lithium metal anodes. Rationally improving SEI uniformity is hindered by poorly understanding the effect of structure and components of SEI on its uniformity. Herein, a bilayer structure of SEI formed by isosorbide dinitrate (ISDN) additives in localized high-concentration electrolytes was demonstrated to improve SEI uniformity. In the bilayer SEI, LiNx Oy generated by ISDN occupies top layer and LiF dominates bottom layer next to anode. The uniformity of lithium deposition is remarkably improved with the bilayer SEI, mitigating the consumption rate of active lithium and electrolytes. The cycle life of lithium metal batteries with bilayer SEI is three times as that with common anion-derived SEI under practical conditions. A prototype lithium metal pouch cell of 430 Wh kg-1 undergoes 173 cycles. This work demonstrates the effect of a reasonable structure of SEI on reforming SEI uniformity.

20.
ACS Appl Bio Mater ; 6(7): 2816-2825, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37326439

RESUMO

Inflammation activation is accompanied by tumor growth, migration, and differentiation. Photodynamic therapy (PDT) can trigger an inflammatory response to cause negative feedback of tumor inhibition. In this paper, a feedback-elevated antitumor amplifier is developed by constructing self-delivery nanomedicine for PDT and cascade anti-inflammation therapy. Based on the photosensitizer chlorin e6 (Ce6) and COX-2 inhibitor indomethacin (Indo), the nanomedicine is prepared via molecular self-assembly technology without additional drug carriers. It is exciting that the optimized nanomedicine (designated as CeIndo) possesses favorable stability and dispersibility in the aqueous phase. Moreover, the drug delivery efficiency of CeIndo is significantly improved, which could be effectively accumulated at the tumor site and internalized by tumor cells. Importantly, CeIndo not only exhibits a robust PDT efficacy on tumor cells but also drastically decreases the PDT-induced inflammatory response in vivo, resulting in feedback-elevated tumor inhibition. By virtue of the synergistic effect of PDT and cascade inflammation suppression, CeIndo tremendously reduces tumor growth and leads to a low side effect. This study presents a paradigm for the development of codelivery nanomedicine for enhanced tumor therapy through inflammation suppression.


Assuntos
Fotoquimioterapia , Humanos , Fotoquimioterapia/efeitos adversos , Fotoquimioterapia/métodos , Nanomedicina , Retroalimentação , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes/farmacologia , Inflamação/tratamento farmacológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA