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1.
Cureus ; 16(8): e66078, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39229391

RESUMO

Background Recently, elective posting has been introduced by the National Medical Commission (NMC) of India in the undergraduate competency-based medical education (CBME) curriculum. To successfully implement it in medical colleges, facilitators (medical teachers) need to commit extra time. Hence, this study aimed to evaluate the impact of online teaching-learning methods for implementing an elective module for undergraduate medical students at Burdwan Medical College and Hospital, West Bengal, India. Methods An online module for systematic review methods was developed using the Delphi method. This module was used to train 30 medical students divided into six groups. One resident and one faculty facilitated each group. After the elective program of 15 days, program feedback and evaluation using the Kirkpatrick model were obtained from the students. Results A total of 30 undergraduate medical students with a mean age of 22.7±0.95 years participated in the study. All of them successfully conducted a systematic review per group. The students' feedback was 86.33% positive, and the project evaluation showed an 84% positive opinion. The highest score was for understanding, facilitators' knowledge, and experience. The lowest score was for the immediate applicability of the knowledge. Conclusion An online systematic review training module can be used for elective teaching-learning for final-year medical students, particularly within limited time and resource constraints. Students appreciated the module's clear objectives, appropriate complexity, and facilitators' expertise, leading to improved communication, engagement, and critical-thinking skills. Despite some limitations, these findings suggest that online learning can complement traditional methods and address logistical challenges in medical education, warranting further research on its long-term impact and broader applicability.

3.
Chem Biol Drug Des ; 104(3): e14626, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39307842

RESUMO

Depression is a prevalent mental disorder, but the side effects of antidepressants also make depressed patients resistant. Effective and safe antidepressants should be developed from traditional herbs, with the aim of reducing the side effects of antidepressants and improving the efficacy of drugs. In this study, the new macamide compound-4 (NMC-4) was synthesized for the first time, addressing the problem of difficult extraction, isolation, and low content of natural macamide. NMC-4 was characterized using mass spectrometry, nuclear magnetic resonance, and infrared spectroscopy. The protective effect of NMC-4 against cell injury was demonstrated to be stronger than that of natural macamide (N-benzylhexadecanamide, XA) using a PC12 cell injury model. The study explored the effects of NMC-4 on chronic unpredictable mild stress (CUMS)-induced depressive symptoms. NMC-4 significantly improved depressive-like behaviors. NMC-4 ameliorated CUMS-induced depressive-like behaviors by mitigating neuroinflammation and modulating the NF-κB/Nrf2 and BDNF/PI3K/Akt pathways.


Assuntos
Antidepressivos , Depressão , Animais , Depressão/tratamento farmacológico , Ratos , Células PC12 , Masculino , Antidepressivos/farmacologia , Antidepressivos/química , Antidepressivos/uso terapêutico , Estresse Psicológico/tratamento farmacológico , Doenças Neuroinflamatórias/tratamento farmacológico , Doenças Neuroinflamatórias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Modelos Animais de Doenças , NF-kappa B/metabolismo , Camundongos , Comportamento Animal/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
4.
Small ; : e2405432, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39295569

RESUMO

LiNi0.8Mn0.1Co0.1O2 (NMC811) is the most promising cathode material for future Li-ion batteries (LIBs). However, the bulk and surface structural instabilities retard its commercial success. Surface chemical instability toward exposure to moisture (H2O and CO2) leads to the formation of residual lithium compounds (RLCs: Li2CO3, LiOH) on the surface. The alkaline RLCs form a resistive layer on the surface of NMC811 by undergoing parasitic side reactions with electrolytes. Herein, an "Adverse-to-Beneficial" approach is proposed to eliminate RLCs by chemically transforming them into a LixPOy (Li3PO4 and LiPO3) interface. The interface protects the NMC811 surface from moisture attack and unwanted side reactions with electrolytes. It enhances the cycle life by retaining 70% of the initial capacity after 300 cycles at a 0.5C rate and 60% after 500 cycles, even at a 5C rate in a voltage window of 3.0-4.3 V versus Li+/Li. The coexistence of two Li-conducting phases lowers the voltage polarization of the kinetically sluggish H1 → M phase transition to unlock fast cycling, reduces cationic disorder, improves coulombic efficiency, enhances ion diffusion kinetics, and minimizes particle crack formation after long-term cycling. Hence, the LixPOy interface yields multifaceted benefits in the storage, processing, and electrochemistry of NMC811.

5.
ACS Appl Mater Interfaces ; 16(38): 50561-50566, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39259850

RESUMO

Li metal batteries (LMBs) have revived people's interest due to their high energy density. This work compares the cycling stability, structure stability, and thermal stability of Li||0.7Nb-NMC 9055 (0.7% Nb-modified LiNi0.9Co0.05Mn0.05O2) system in commercial carbonate electrolyte (1.0 M LiPF6 in EC/DMC) and designed carbonate electrolyte (1.0 M LiPF6-0.125 M LiNO3-0.025 M Mg(TFSI)2 in FEC-EMC). Li||0.7Nb-NMC 9055 battery with designed carbonate electrolyte exhibited superior capacity retention, 80% after ∼500 cycles. This can be explained by the improved mechanical integrity of the secondary particles and large reduced charge transfer resistance. Further, the real-time thermal monitoring of full cell via a high-precision, multimode calorimeter TAM IV Micro XL shows that the designed carbonate electrolyte with multisalt additive and FEC cosolvent has less heat release during the charging and discharge process, allowing these high-nickel (Ni) cathodes to reach closer to their full potential.

6.
ACS Appl Mater Interfaces ; 16(32): 42034-42048, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39102531

RESUMO

Solid-state batteries promise higher energy density and improved safety compared with lithium-ion batteries. However, electro-chemomechanical instabilities at the solid electrolyte interface with the cathode and the anode hinder their large scale implementation. Here, we focus on resolving electro-chemo-mechanical instability mechanisms and their onset conditions between a state-of-the-art cathode, LiNi0.6Mn0.2Co0.2O2 (NMC622), and the garnet Li7La3Zr2O12 (LLZO) solid electrolyte. We used thin-film NMC622 on LLZO pellets to place the interfacial region within the detection depth of the X-ray characterization techniques. The experimental probes of the near-interface region included in operando X-ray absorption spectroscopy and ex situ focused ion beam scanning electron microscopy. Electrochemical degradation was not observable during cycling at room temperature with 4.3 V versus Li/Li+ charge voltage cutoff, or with stepwise potentiostatic hold up to 4.1 V versus Li/Li+. In contrast, secondary phases including reduced transition metal species (Ni2+, Co2+) were found after cycling up to 4.3 V versus Li/Li+ at 80 °C and during potentiostatic hold at 4.3 V versus Li/Li+ (Ni2+). Intergranular cracks between NMC622 grains and delamination at the NMC622|LLZO interface occurred readily after the first charge. These interface reaction products and mechanical failure lowered the capacity and cell efficiency due to partial loss of the NMC622 phase, partial loss of contact at the interface, and a higher polarization resistance. Electrochemical instability between delithiated NMC622 and LLZO could be mitigated by using a low charge voltage cutoff or cycling at lower temperature. Ways to engineer the mechanical properties to avoid crack deflection and delamination at the interface are also discussed for enhancing mechanical stability.

7.
Chemosphere ; 364: 143209, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39216553

RESUMO

The expansion of technology motivates the increase of global demands for critical minerals. In this context, the exploration of secondary sources of these components is expanding. End-of-life batteries can be seen as potential sources of lithium, cobalt, nickel and manganese for electric vehicles or diverse applications in electronic equipments. This paper provides a comprehensive evaluation of the recovery of metals from waste batteries with diverse chemistry composition. Lithium cobalt oxide (LCO) and lithium nickel cobalt manganese oxide (NMC) batteries were co-treated with polyvinyl chloride (PVC) channels under supercritical water, varying reaction temperature (400-600 °C) and PVC/Battery composition (0-3 m/m) in a tubular continuous reactor. Results show high recovery rates for all metals, with up to 90% percentage recovery of lithium and cobalt in all cases. Temperature and feed composition were identified as determining factors for the recovery of lithium from LCO batteries. In the case of cobalt, temperature was identified as the most important factor that affects its recovery. The selected optimal conditions for cobalt recovery in the solid products of reactions were identified for batteries LCO and NMC: temperature of 600 °C and PVC/Battery ratio of 3.0 and temperature of 500 °C and PVC/Battery ratio of 1.5, respectively. Environmental impacts, primarily Global Warming Potential (GWP), were minimal, with 4.71·10-5 kg CO2 eq., indicating the benefits of the process as an eco-efficient and promising route for the recycling of valuable metals.


Assuntos
Cobalto , Fontes de Energia Elétrica , Lítio , Níquel , Óxidos , Cobalto/química , Cobalto/análise , Óxidos/química , Lítio/química , Níquel/química , Níquel/análise , Reciclagem/métodos , Temperatura , Metais/química , Metais/análise , Manganês/química , Manganês/análise , Compostos de Manganês/química
8.
J Family Med Prim Care ; 13(7): 2541-2544, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39071001

RESUMO

Policy decisions shape strategies which in turn influence the outcome. The expected outcome of medical education in India is to produce an MBBS graduate of first contact. Are we able to do so or are we failing in that and what are the reasons behind our failure Is it a failure on part of the regulatory body to align with the expected outcome using a continuity of approach or a willingness to accept transitory as the process to achieve the objective?

9.
Sci Rep ; 14(1): 17369, 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39075102

RESUMO

Recycling lithium (Li) from spent lithium-ion batteries (LIBs) due to the depletion of natural resources and potential toxicity is becoming a progressively favourable measure to realize green sustainability. Presently, the prevalent recycling technique relying on pyrometallurgy lacks the capability to extract lithium. Meanwhile, conventional hydrometallurgical processes frequently employ robust acidic solutions like sulfuric acid and precipitation agents such as sodium carbonate. Unfortunately, this approach tends to result in the extraction of lithium at the end of a lengthy process chain, leading to associated losses and creating challenges in managing complex waste. This study addresses a cost-effective and environmentally friendly early-stage lithium recovery from the thermally conditioned black mass. In this sense, a thermally conditioned black mass is subjected to the carbonization process in a water solution to transform the water-insoluble Li phase into soluble lithium bicarbonate (LiHCO3) and carbonate (Li2CO3) facilitating its selective separation from other elements. Response surface methodology (RSM)-a statistical tool integrated with central composite design (CCD) is employed to optimize the parameters for Li recovery. Temperature, solid-liquid (S/L) ratio, leaching time and CO2 flow rate are considered as variable factors in modelling the optimum recycling process. A quadratic regression model is developed for Li recovery and based on ANOVA analysis, (S/L) ratio, temperature and time are identified as statistically significant factors. Experimental results demonstrate a maximum leaching efficiency of lithium with optimized parameter set, achieving a recovery rate of 97.18% with a fit response of 93.54%.

10.
J Environ Manage ; 366: 121710, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38986378

RESUMO

We report an environmentally benign recycling approach for large-capacity nickel manganese cobalt (NMC) batteries through the electrochemical concentration of lithium on the anode and subsequent recovery with only water. Cycling of the NMC pouch cells indicated the potential for maximum lithium recovery at a 5C charging rate. The anodes extracted from discharged and disassembled cells were submerged in deionized water, resulting in lithium dissolution and graphite recovery from the copper foils. A maximum of 13 mg of lithium salts per 100 mg of the anode, copper current collector, and separator was obtained from NMC pouch cell cycled at a 4C charging rate. The lithium salts extracted from batteries cycled at low C-rates were richer in lithium carbonate, while the salts from batteries cycled at high C-rates were richer in lithium oxides and peroxides, as determined by X-Ray photoelectron spectroscopy. The present method can be successfully used to recover all the pouch cell components: lithium, graphite, copper, and aluminum current collectors, separator, and the cathode active material.


Assuntos
Fontes de Energia Elétrica , Lítio , Lítio/química , Água/química , Eletrodos , Solventes/química , Cobalto/química , Reciclagem , Níquel/química , Manganês/química , Grafite/química , Cobre/química
11.
ChemSusChem ; : e202401128, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058577

RESUMO

With the rapidly increasing demand for lithium ion batteries (LIBs), recycling the metals found in spent cathodes is mandatory to both alleviate shortages resulting from the mining of natural metal ores and manage the disposal of spent LIBs. The use of deep eutectic solvents (DESs) for metals recovery from spent cathodes of LIBs (e. g., LCO and NMC types) offers a sustainable yet efficient alternative to conventional hydrometallurgical processes. Nonetheless, g efforts are required to use milder temperatures and higher mass loadings, thus ensuring cost-effectiveness. In this latter regard, addressing the reutilization of DESs in subsequent stages of metal extraction, and streamlining or eliminating the chemical procedures employed for metal separation, is even more crucial to guarantee the economic feasibility of the recycling process. Herein, we have prepared a DES that provides extraction efficiencies of ca. 100 % for every metal of NMC cathodes even at mild experimental conditions (e. g., 60 °C) and for loadings as high as 70 mgNMC/gDES. Moreover, we have pioneered the direct use of leachates containing DESs and metals as electrolytes for supercapacitors. This approach enables the reintroduction of DESs and the recovered metals into the value chain with a minimal economic and environmental impact.

12.
Small ; : e2401610, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38856970

RESUMO

Herein, the design of novel and safe electrolyte formulations for high-voltage Ni-rich cathodes is reported. The solvent mixture comprising 1,1,2,2-tetraethoxyethane and propylene carbonate not only displays good transport properties, but also greatly enhances the overall safety of the cell thanks to its low flammability. The influence of the conducting salts, that is, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium bis(fluorosulfonyl)imide (LiFSI), and of the additives lithium bis(oxalato)borate (LiBOB) and lithium difluoro(oxalato)borate (LiDFOB) is examined. Molecular dynamics simulations are carried out to gain insights into the local structure of the different electrolytes and the lithium-ion coordination. Furthermore, special emphasis is placed on the film-forming abilities of the salts to suppress the anodic dissolution of the aluminum  current collector and to create a stable cathode electrolyte interphase (CEI). In this regard, the borate-based additives significantly alleviate the intrinsic challenges associated with the use of LiTFSI and LiFSI salts. It is worth remarking that a superior cathode performance is achieved by using the LiFSI/LiDFOB electrolyte, displaying a high specific capacity of 164 mAh g-1 at 6 C and ca. 95% capacity retention after 100 cycles at 1 C. This is attributed to the rich chemistry of the generated CEI layer, as confirmed by ex situ X-ray photoelectron spectroscopy.

13.
Adv Mater ; 36(30): e2400259, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38881361

RESUMO

Li-rich NMCs layered oxides, with the general formula of Li[LixNiyMnzCo1- x - y - z]O2, are known for their exceptionally high capacities but remain yet to be practicalized in the real world. They have attracted enormous research attention due to their complex structure and intriguing redox mechanisms, with a particular focus on anionic redox over the past decade. While fundamental understandings are fruitful, the practical considerations are emphasized here by providing perspectives on how Li-rich NMCs are limited by practical roadblocks and guidelines on how to cope with these limitations. It is also demonstrated that, via a techno-economic analysis, Li-rich NMCs have material cost ($/kg) highly dependent on the lithium price, but still preserve the dominance of lower pack cost ($/kWh) than other cathode candidates principally owing to their larger material energy densities. In addition to their pure application in electric-vehicle batteries, using them as "electrode additive" or "sacrificial agent" can further multiply their practicalities in assortment of scenarios, which is further discussed.

14.
Small ; 20(38): e2400762, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38794872

RESUMO

Single-crystal lithium-nickel-manganese-cobalt-oxide (SC-NMC) is attracting increasing attention due to its excellent structural stability. However, its practical production faces challenges associated with complex precursor preparation processes and severe lithium-nickel cation mixing at high temperatures, which restricts its widespread application. Here, a molten-salt-assisted method is proposed using low-melting-point carbonates. This method obviates the necessity for precursor processes and simplified the synthetic procedure for SC-NMC down to a single isothermal sintering step. Multiple characterizations indicate that the acquired SC-LiNi0.6Mn0.2Co0.2O2 (SC-622) exhibits favorable structural capability against intra-granular fracture and suppressive Li+/Ni2+ cation mixing. Consequently, the SC-622 exhibits superior electrochemical performance with a high initial specific capacity (174 mAh g-1 at 0.1 C, 3.0-4.3 V) and excellent capacity retention (87.5% after 300 cycles at 1C). Moreover, this molten-salt-assisted method exhibits its effectiveness in directly regenerating SC-622 from spent NMC materials. The recovered material delivered a capacity of 125.4 mAh g-1 and retained 99.4% of the initial capacity after 250 cycles at 1 C. This work highlights the importance of understanding the process-structure-property relationships and can broadly guide the synthesis of other SC Ni-rich cathode materials.

15.
ACS Appl Mater Interfaces ; 16(22): 28683-28693, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38768951

RESUMO

Ni-rich layered oxides LiNi1-x-yMnxCoyO2 (NMC811, x = 0.1 and y = 0.1) are considered promising cathode materials in lithium-ion batteries (LiBs) due to their high energy density. However, those suffer a severe capacity loss upon cycling at high delithiated states. The loss of performance over time can be retarded by Zr doping. Herein, a small amount of Zr is added to NMC811 material via two alternative pathways: during the formation of the transition metal (TM) hydroxide precursor at the co-precipitation step (0.1%-Zr-cp) and during the lithiation at the solid-state synthesis step (0.1%-Zr-ss). In this work, the crystallographic Zr uptake in both 0.1%-Zr-ss and 0.1%-Zr-cp is determined and quantified through synchrotron X-ray diffraction and X-ray absorption spectroscopy. We prove that the inclusion of Zr in the TM site for 0.1%-Zr-cp leads to an improvement of both specific capacity (156 vs 149 mAh/g) and capacity retention (85 vs 82%) upon 100 cycles compared to 0.1%-Zr-ss where the Zr does not diffuse into the active material and forms only an extra phase separated from the NMC811 particles.

16.
Curr Top Dev Biol ; 159: 232-271, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38729677

RESUMO

The anterior-to-posterior (head-to-tail) body axis is extraordinarily diverse among vertebrates but conserved within species. Body axis development requires a population of axial progenitors that resides at the posterior of the embryo to sustain elongation and is then eliminated once axis extension is complete. These progenitors occupy distinct domains in the posterior (tail-end) of the embryo and contribute to various lineages along the body axis. The subset of axial progenitors with neuromesodermal competency will generate both the neural tube (the precursor of the spinal cord), and the trunk and tail somites (producing the musculoskeleton) during embryo development. These axial progenitors are called Neuromesodermal Competent cells (NMCs) and Neuromesodermal Progenitors (NMPs). NMCs/NMPs have recently attracted interest beyond the field of developmental biology due to their clinical potential. In the mouse, the maintenance of neuromesodermal competency relies on a fine balance between a trio of known signals: Wnt/ß-catenin, FGF signalling activity and suppression of retinoic acid signalling. These signals regulate the relative expression levels of the mesodermal transcription factor Brachyury and the neural transcription factor Sox2, permitting the maintenance of progenitor identity when co-expressed, and either mesoderm or neural lineage commitment when the balance is tilted towards either Brachyury or Sox2, respectively. Despite important advances in understanding key genes and cellular behaviours involved in these fate decisions, how the balance between mesodermal and neural fates is achieved remains largely unknown. In this chapter, we provide an overview of signalling and gene regulatory networks in NMCs/NMPs. We discuss mutant phenotypes associated with axial defects, hinting at the potential significant role of lesser studied proteins in the maintenance and differentiation of the progenitors that fuel axial elongation.


Assuntos
Padronização Corporal , Mesoderma , Animais , Padronização Corporal/genética , Mesoderma/metabolismo , Mesoderma/citologia , Mesoderma/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Transdução de Sinais , Proteínas com Domínio T/metabolismo , Proteínas com Domínio T/genética , Diferenciação Celular , Cabeça/embriologia
17.
Uisahak ; 33(1): 103-134, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38768992

RESUMO

This article focuses on the medical activities conducted by major hospitals in downtown Seoul during the April Revolution in 1960, examining their experiential context and significance. The influx of guns and bullets into Korean society following the liberation in 1945 intertwined with the political and social conflicts of the period, resulting in numerous assassinations, crimes, and terrorism. Gunshot wounds were traumas that became a part of the everyday life of Koreans, as well as scars which reflected their historical contexts. At the same time, the frequent occurrence of gunshot wounds led to the development of medical capacities to treat them. The Korean surgical academia expanded its technical foundation with experiences during and after the Korean War. This progress was particularly noticeable in areas closely related to gunshot wounds, such as craniotomy, thoracotomy, vascular anastomosis, debridement, anesthesia, and blood transfusion. Major hospitals in downtown Seoul served as medical spaces where these experimental and technical foundations were concentrated, allowing them to minimize the death toll despite the massive gunfire by the National Police in April 1960. Thus, the aftermath of the epidemic of gunshots resulted in a rather paradoxical outcome. This development became a resource for doctors and nurses, who added their revolutionary implications in reconstructing the experience of April 1960 in their various memoirs and reports. While memoirs reorganized general medical activities, portraying injured patients as participants in the revolution, reports provided forensic descriptions and interpretations of the deaths, giving authority to the main narrative of the revolution. As the interpretations and significance based on historical contexts gained prominence, major hospitals in downtown Seoul also developed a sense of place closely associated with the revolution.


Assuntos
Hospitais , Ferimentos por Arma de Fogo , Hospitais/história , Ferimentos por Arma de Fogo/história , Humanos , História do Século XX , Seul , Guerra da Coreia
18.
J Med Life ; 17(1): 81-86, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38737652

RESUMO

Pemphigus vulgaris (PV) is a potentially fatal autoimmune disease characterized by blistering of the skin, mucous membranes, and oral cavity. Genetics are implicated in its etiology, with the ST18 gene identified as a potential risk factor for pemphigus in certain populations, suggesting its role as a novel molecular target for therapeutic intervention. This study aimed to detect single nucleotide polymorphisms (SNPs) rs17315309 A/G and rs2304365 C/G in the ST18 gene among Iraqi/Arabic patients with PV. A total of 90 Iraqi subjects participated in this study, including 45 patients diagnosed with PV and 45 healthy controls. SNP analysis was performed using High-Resolution Melt Analysis (HRMA) with Eva Green I Dye. For SNP rs17315309 A/G, the distribution of heterozygous genotypes showed highly significant differences between the patient and healthy groups (P = 0.005), with the mutant G-allele being significantly more prevalent in patients than in the healthy group (P = 0.001). In contrast, for SNP rs2304365 C/G, the distribution of heterozygous and mutant genotypes did not differ significantly between patients and healthy individuals (P = 0.8 and P = 0.3, respectively), with the mutant G-allele also showing no significant difference (P = 0.4). Our data indicate a significant association between PV and the rs17315309 A/G SNP in the ST18 gene among the Iraqi population of Arabic origin. However, no association was found between patients with PV and the rs2304365 C/G SNP in the same gene.


Assuntos
Pênfigo , Polimorfismo de Nucleotídeo Único , Humanos , Pênfigo/genética , Iraque , Polimorfismo de Nucleotídeo Único/genética , Masculino , Feminino , Adulto , Estudos de Casos e Controles , Predisposição Genética para Doença , Pessoa de Meia-Idade , Genótipo
19.
ACS Appl Mater Interfaces ; 16(15): 19720-19729, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38571476

RESUMO

LiNi0.8Mn0.1Co0.1O2 (NMC811) is the most promising cathode material for next-generation lithium-ion batteries (LIBs). However, the chemical instability of the material during air exposure leads to the formation of residual lithium compounds (RLCs: LiOH and Li2CO3) on the surface and inhibits its practical application. Here, we propose a chemical conversion process to remove RLCs by utilizing them and forming a hybrid coating layer on the surface of NMC811 that contains Li3PO4, LiMn2O4, and LiMnPO4 phases, yielding multifaceted benefits. The hybrid layer on the surface protects the material from undesirable side reactions. It improves the cycle life of NMC811 by retaining 80% of its initial capacity after 300 cycles and 66% after 500 cycles at a 0.5C rate in the operating voltage of 3.0-4.3 V. The process enables high-voltage (4.7 V vs Li+/Li) operation by stabilizing the electrode-electrolyte interface, reduces the degree of cationic disorder and the voltage polarization for phase transitions, improves Coulombic efficiency and ion diffusion kinetics, and minimizes the secondary particle crack formation over long-term cycling. In fact, the coating reduces the detrimental effects of RLCs, leaves the surface for better Li+ transport, and hence significantly improves the electrochemical performance of NMC811.

20.
Br J Community Nurs ; 29(4): 160-161, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38564445

RESUMO

In this month's Policy column, Iwan Dowie explores the laws of confidentiality, which forms part of the legal obligation of every community nurse.


Assuntos
Confidencialidade , Humanos
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