Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 801
Filtrar
1.
Adv Mater ; : e2403229, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38598727

RESUMO

Li-CO2 batteries are regarded as promising high-energy-density energy conversion and storage devices, but their practicability is severely hindered by the sluggish CO2 reduction/evolution reaction (CORR/COER) kinetics. Due to the various crystal structures and unique electronic configuration, Mn-based cathode catalysts have shown considerable competition to facilitate CORR/COER. However, the specific active sites and regulation principle of Mn-based catalysts remain ambiguous and limited. Herein, this work designs novel Mn dual-active sites (MOC) supported on N-doped carbon nanofibers and conduct a comprehensive investigation into the underlying relationship between different Mn active sites and their electrochemical performance in Li-CO2 batteries. Impressively, this work finds that owing to the in situ generation and stable existence of Mn(III), MOC undergoes obvious electrochemical reconstruction during battery cycling. Moreover, a series of characterizations and theoretical calculations demonstrate that the different electronic configurations and coordination environments of Mn(II) and Mn(III) are conducive to promoting CORR and COER, respectively. Benefiting from such a modulating behavior, the Li-CO2 batteries deliver a high full discharge capacity of 10.31 mAh cm-2, and ultra-long cycle life (327 cycles/1308 h). This fundamental understanding of MOC reconstruction and the electrocatalytic mechanisms provides a new perspective for designing high-performance multivalent Mn-integrated hybrid catalysts for Li-CO2 batteries.

2.
Heliyon ; 10(7): e28733, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38576558

RESUMO

Objectives: Chronic obstructive pulmonary disease (COPD) is a prevalent respiratory disorder characterized by progressive airflow limitation. This meta-analysis aims to evaluate the effectiveness of respiratory muscle training (RMT) on key pulmonary function parameters, inspiratory muscle strength and quality of life in patients with stable COPD. Methods: A comprehensive search was conducted in the databases including PubMed, Cochrane, Web of Science, Embase, and ClinicalTrials.gov, from their inception to June 12, 2023. Randomized controlled trials (RCTs) evaluating the impact of RMT on stable COPD were included for meta-analysis. Results: In total, 12 RCTs involving 453 participants were included in the meta-analysis. RMT demonstrated a significant increase in maximal inspiratory pressure (PImax, MD, 95% CI: 14.34, 8.17 to 20.51, P < 0.001) but not on maximal expiratory pressure (PEmax). No significant improvement was observed in 6-Min walk test (6MWT), dyspnea, forced expiratory volume in 1 s (FEV1), forced vital capacity ratio (FVC) and quality of life between RMT and control groups. However, subgroup analysis revealed a significant negative effect of RMT alone on FEV1/FVC (MD, 95% CI: 2.59, -5.11 to -0.06, P = 0.04). When RMT was combined with other interventions, improvements in FEV1/FVC and FEV1 were found, although not statistically significant. Conclusion: RMT can effectively improve maximal inspiratory pressure in stable COPD patients, but the effect is slight in improving lung function, dyspnea and quality of life. It is recommended to combine with other treatment strategies to comprehensively improve the prognosis of COPD patients.

3.
Sci Bull (Beijing) ; 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38616150

RESUMO

Traditional dual-ion lithium salts have been widely used in solid polymer lithium-metal batteries (LMBs). Nevertheless, concentration polarization caused by uncontrolled migration of free anions has severely caused the growth of lithium dendrites. Although single-ion conductor polymers (SICP) have been developed to reduce concentration polarization, the poor ionic conductivity caused by low carrier concentration limits their application. Herein, a dual-salt quasi-solid polymer electrolyte (QSPE), containing the SICP network as a salt and traditional dual-ion lithium salt, is designed for retarding the movement of free anions and simultaneously providing sufficient effective carriers to alleviate concentration polarization. The dual salt network of this designed QSPE is prepared through in-situ crosslinking copolymerization of SICP monomer, regular ionic conductor, crosslinker with the presence of the dual-ion lithium salt, delivering a high lithium-ion transference number (0.75) and satisfactory ionic conductivity (1.16 × 10-3 S cm-1 at 30 °C). Comprehensive characterizations combined with theoretical calculation demonstrate that polyanions from SICP exerts a potential repulsive effect on the transport of free anions to reduce concentration polarization inhibiting lithium dendrites. As a consequence, the Li||LiFePO4 cell achieves a long-cycle stability for 2000 cycles and a 90% capacity retention at 30 °C. This work provides a new perspective for reducing concentration polarization and simultaneously enabling enough lithium-ions migration for high-performance polymer LMBs.

4.
Nat Commun ; 15(1): 3299, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632245

RESUMO

Improving the absorption of electromagnetic waves at low-frequency bands (2-8 GHz) is crucial for the increasing electromagnetic (EM) pollution brought about by the innovation of the fifth generation (5G) communication technology. However, the poor impedance matching and intrinsic attenuation of material in low-frequency bands hinders the development of low-frequency electromagnetic wave absorbing (EMWA) materials. Here we propose an interface-induced dual-pinning mechanism and establish a magnetoelectric bias interface by constructing bilayer core-shell structures of NiFe2O4 (NFO)@BiFeO3 (BFO)@polypyrrole (PPy). Such heterogeneous interface could induce distinct magnetic pinning of the magnetic moment in the ferromagnetic NFO and dielectric pinning of the dipole rotation in PPy. The establishment of the dual-pinning effect resulted in optimized impedance and enhanced attenuation at low-frequency bands, leading to better EMWA performance. The minimum reflection loss (RLmin) at thickness of 4.43 mm reaches -65.30 dB (the optimal absorption efficiency of 99.99997%), and the effective absorption bandwidth (EAB) can almost cover C-band (4.72 ~ 7.04 GHz) with low filling of 15.0 wt.%. This work proposes a mechanism to optimize low-frequency impedance matching with electromagnetic wave (EMW) loss and pave an avenue for the research of high-performance low-frequency absorbers.

6.
Ophthalmology ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38661617
8.
J Phys Chem Lett ; 15(10): 2859-2866, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38445979

RESUMO

Transition metal hydr(oxy)oxides (TMHs) are considered efficient electrocatalysts for the oxygen evolution reaction (OER) under alkaline conditions. Toward identification of potential descriptors to circumvent the scaling relation limit for the OER, first-principles calculations were used to quantify the effects on the overpotential of different s (Mg), p (Al), and d (Ti, V, Cr, Fe, Co, Sc, and Zn) electron dopants in Ni-based TMHs. Both the adsorbate evolution mechanism (AEM) and the lattice oxygen-mediated mechanism (LOM) were examined. The results demonstrate that the formation energy of oxygen vacancies (EVO) is strongly affected by the chemical nature of the dopants. A linear relationship is identified between EVO and the free energy difference for the oxygen-oxygen coupling. A descriptor could be employed to discriminate whether the LOM is energetically favored over the AEM. These findings fill existing gaps in appropriate yet computationally light descriptors for direct identification between the AEM and LOM.

9.
Sci Bull (Beijing) ; 69(8): 1100-1108, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38423872

RESUMO

Catalytic conversion of nitrate (NO3-) pollutants into ammonia (NH3) offers a sustainable and promising route for both wastewater treatment and NH3 synthesis. Alkali cations are prevalent in nitrate solutions, but their roles beyond charge balance in catalytic NO3- conversion have been generally ignored. Herein, we report the promotion effect of K+ cations in KNO3 solution for NO3- reduction over a TiO2-supported Ni single-atom catalyst (Ni1/TiO2). For photocatalytic NO3- reduction reaction, Ni1/TiO2 exhibited a 1.9-fold NH3 yield rate with nearly 100% selectivity in KNO3 solution relative to that in NaNO3 solution. Mechanistic studies reveal that the K+ cations from KNO3 gradually bonded with the surface of Ni1/TiO2, in situ forming a K-O-Ni moiety during reaction, whereas the Na+ ions were unable to interact with the catalyst in NaNO3 solution. The charge accumulation on the Ni sites induced by the incorporation of K atom promoted the adsorption and activation of NO3-. Furthermore, the K-O-Ni moiety facilitated the multiple proton-electron coupling of NO3- into NH3 by stabilizing the intermediates.

11.
Anal Sci ; 40(4): 701-707, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38316711

RESUMO

In this work, a novel zirconium phosphonate (ZrPR1R2) was prepared by decorating both the aminoethoxy- group (R1) and the carboxypropyl- group (R2) on the zirconium phosphate layers in order to manipulate further the immobilization of the peroxidase (POD), and an antioxidant biosensor with higher sensitivity was constructed by dropping the POD/ZrPR1R2 composite onto the glassy carbon electrode surface. The activity of the POD/ZrPR1R2 composite was detected by Uv-vis spectra. The direct electrochemical behavior, the electrocatalytic response to dissolved oxygen and hydrogen peroxide, as well as the ability to detect total antioxidant capacity in tea sample were investigated by the methods of cyclic voltammetry. The results indicated that the immobilization of POD in ZrPR1R2 nanosheets matrix enhanced the enzymatic activity, and achieved the fast and direct electron transfer between POD and glassy carbon electrode. Moreover, the POD/ZrPR1R2 composite modified electrode show the electrocatalytic response to hydrogen peroxide in the linear range of 8.8×10-8 to 8.8×10-7 mol L-1, with the detection limit of 3.3×10-8 mol L-1. Attributing to the sensitive response to dissolved oxygen, the total antioxidant capacity can be detected directly in the real tea water by this POD/ZrPR1R2 composite modified electrode.


Assuntos
Antioxidantes , Técnicas Biossensoriais , Peroxidase , Peróxido de Hidrogênio/análise , Zircônio , Carbono , Eletrodos , Peroxidases , Oxigênio , Chá , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos
12.
Eur Spine J ; 33(3): 1055-1060, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38341814

RESUMO

PURPOSE: It is the first study to evaluate the predictive value of the geriatric nutritional risk index (GNRI) on postoperative delirium (POD) after transforaminal lumber interbody fusion (TLIF) in elderly patients with degenerative lumbar diseases. METHODS: A retrospective study was conducted to assess the outcomes of TLIF surgery in elderly patients with lumbar degenerative disease between the years 2016 and 2022. Delirium was diagnosed by reviewing postoperative medical records during hospitalization, utilizing the Confusion Assessment Method. The geriatric nutritional risk index was calculated using the baseline serum albumin level and body weight. Multivariate logistic regression analysis was employed to identify the association between preoperative GNRI and postoperative delirium (POD). Additionally, a receiver operating characteristic curve was utilized to determine the optimal GNRI cutoff for predicting POD. RESULTS: POD was observed in 50 of the 324 patients. The GNRI was visibly reduced in the delirium group. The mean GNRI was 93.0 ± 9.1 in non-delirium group and 101.2 ± 8.2 in delirium group. On multivariate logistic regression, Risk of POD increases significantly with low GNRI and was an independent factor in predicting POD following TLIF (OR 0.714; 95% CI 0.540-0.944; p = 0.018). On receiver operating characteristic curve, the area under curve (AUC) for GNRI was 0.738 (95% CI 0.660-0.817). The cutoff value for GNRI according to the Youden index was 96.370 (sensitivity: 66.0%, specificity: 70.4%). CONCLUSION: Our study indicated that lower GNRI correlated significantly with POD after TLIF. Performing GNRI evaluation prior to TLIF may be an effective approach of predicting the risk for POD among elderly patients with degenerative lumbar diseases.


Assuntos
Delírio do Despertar , Fusão Vertebral , Humanos , Idoso , Estado Nutricional , Avaliação Nutricional , Estudos Retrospectivos , Vértebras Lombares/cirurgia , Fusão Vertebral/efeitos adversos , Fatores de Risco
13.
Spine J ; 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38301901

RESUMO

BACKGROUND CONTEXT: Cage subsidence after lumbar fusion can lead to many adverse outcomes. Low bone mineral density (BMD) is a widely recognized risk factor for cage subsidence. Conventional methods can predict and evaluate BMD, but there are many shortcomings. Recently, MRI-based assessment of bone quality in specific parts of the vertebral body has been proposed, including scores for vertebral bone quality (VBQ) and endplate bone quality (EBQ). However, the predictive accuracy of the two scoring systems for cage subsidence after transforaminal lumbar interbody fusion (TLIF) remains unknown. Therefore, we investigated MRI-based VBQ and EBQ scores for assessing bone quality and compared their predictive value for cage subsidence after TLIF. PURPOSE: To compare the predictive value between MRI-based VBQ and EBQ scores for cage subsidence after TLIF. STUDY DESIGN/SETTING: A retrospective case-control study PATIENTS SAMPLE: Patients with degenerative lumbar diseases underwent single-level TLIF at our medical center between 2014 and 2020, all of whom had preoperative MRIs available. OUTCOMES MEASURES: Cage subsidence, disc height, VBQ score, EBQ score, upper and lower vertebral body bone quality (UL-VBQ) score. METHODS: Data were retrospectively examined for a consecutive sample of 346 patients who underwent TLIF at our medical center between 2014 and 2020. Patients who subsequently experienced cage subsidence or not were matched to each other based on propensity scoring, and the two matched groups (52 patients each) were compared using conditional logistic regression to investigate the association between the potential radiographic factors and cage subsidence. Scores for VBQ and EBQ were assessed for their ability to predict cage subsidence in the matched patients based on the area under the receiver operative characteristic curve (AUC). RESULTS: Among matched patients, those who suffered cage subsidence had significantly higher VBQ score (3.7 vs. 3.1, p<.001) and EBQ score (5.0 vs. 4.3, p<.001), and regression linked greater risk of subsidence to higher VBQ score (OR 4.557, 95% CI 1.076-19.291, p=.039) and higher EBQ score (OR 5.396, 95% CI 1.158-25.146, p=.032). A cut-off VBQ score of 3.4 predicted the cage subsidence among matched patients with an AUC of 0.799, sensitivity of 84.6%, and specificity of 69.2%. A cut-off EBQ score of 4.7 predicted subsidence with an AUC of 0.829, sensitivity of 76.9%, and specificity of 82.7%. CONCLUSION: Higher VBQ and EBQ scores are associated with a greater risk of cage subsidence following TLIF, and EBQ may perform better because of greater specificity.

14.
ACS Nano ; 18(6): 5132-5140, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38311845

RESUMO

Flexible all-solid-state lithium-carbon dioxide batteries (FASSLCBs) are recognized as a next-generation energy storage technology by solving safety and shuttle effect problems. However, the present FASSLCBs rely heavily on high-temperature operation due to sluggish solid-solid-gas multiphase mass transfer and unclear capacity degradation mechanism. Herein, we designed bicontinuous hierarchical porous structures (BCHPSs) for both solid polymer electrolyte and cathode for FASSLCBs to facilitate the mass transfer in all connected directions. The formed large Lewis acidic surface effectively promotes the lithium salt dissociation and the CO2 conversion. Furthermore, it is unraveled that the battery capacity degradation originates from the "dead Li2CO3" formation, which is inhibited by the fast decomposition of Li2CO3. Accordingly, the assembled FASSLCBs exhibit an excellent cycling stability of 133 cycles at 60 °C, which is 2.7 times longer than that without BCHPSs, and the FASSLCBs can be operated repeatedly even at room temperature. This BCHPS method and fundamental deactivation mechanism provide a perspective for designing FASSLCBs with long cycling life.

15.
Small ; : e2310530, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38317526

RESUMO

Rechargeable aprotic Li-CO2 batteries have aroused worldwide interest owing to their environmentally friendly CO2 fixation ability and ultra-high specific energy density. However, its practical applications are impeded by the sluggish reaction kinetics and discharge product accumulation during cycling. Herein, a flexible composite electrode comprising CoSe2 nanoparticles embedded in 3D carbonized melamine foam (CoSe2 /CMF) for Li-CO2 batteries is reported. The abundant CoSe2 clusters can not only facilitate CO2 reduction/evolution kinetics but also serve as Li2 CO3 nucleation sites for homogeneous discharge product growth. The CoSe2 /CMF-based Li-CO2 battery exhibits a large initial discharge capacity as high as 5.62 mAh cm-2 at 0.05 mA cm-2 , a remarkably small voltage gap of 0.72 V, and an ultrahigh energy efficiency of 85.9% at 0.01 mA cm-2 , surpassing most of the noble metal-based catalysts. Meanwhile, the battery demonstrates excellent cycling stability of 1620 h (162 cycles) at 0.02 mA cm-2 with an average overpotential of 0.98 V and energy efficiency of 85.4%. Theoretical investigations suggest that this outstanding performance is attributed to the suitable CO2 /Li adsorption and low Li2 CO3 decomposition energy. Moreover, flexible Li-CO2 pouch cell with CoSe2 /CMF cathode displays stable power output under different bending deformations, showing promising potential in wearable electronic devices.

16.
Int Ophthalmol ; 44(1): 5, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38315276

RESUMO

PURPOSE: This study aimed to investigate the value of the orbital septum attachment site on the levator aponeurosis (OSASLA) sling in correcting mild congenital blepharoptosis. METHODS: A total of 60 patients (92 eyes) with mild congenital blepharoptosis (levator function ≥ 8 mm) were treated in our hospital from January to October 2021, and relevant data of these patients were collected. All patients underwent OSASLA sling for ptosis correction. The distances from the superior tarsal border to the OSASLA were measured. The primary outcome was the number of postoperative changes in the marginal reflex distance 1 (MRD1). Pearson's correlation coefficient between the distance from the superior tarsal border to the OSASLA and the height of the upper eyelid elevated was analyzed. RESULTS: Fifty-eight patients (89 eyes) successfully underwent OSASLA sling surgery. The preoperative MRD1 was 1.4-3.6 mm (mean 2.1 ± 0.5 mm), and the postoperative MRD1 was 3.4-5.0 mm (mean 3.7 ± 0.6 mm). The distance from the superior tarsal border to the OSASLA sling was significantly and positively correlated with the height of the upper eyelid elevation (r = 0.7328, P < 0.0001). The eyelid margin positions of the patients did not regress substantially during 6-18 months of follow-up. CONCLUSIONS: Compared with the shortening of levator palpebrae superioris (LPS) and pleating of LPS, the OSASLA sling is a less invasive, more effective, and easy-operating surgery for mild congenital blepharoptosis.


Assuntos
Blefaroplastia , Blefaroptose , Humanos , Blefaroptose/congênito , Aponeurose/cirurgia , Lipopolissacarídeos , Estudos Retrospectivos , Músculos Oculomotores/cirurgia , Resultado do Tratamento
17.
Free Radic Biol Med ; 214: 219-235, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38367927

RESUMO

Ulcerative colitis (UC) is a chronic gastrointestinal disease that can be managed with 5-aminosalicylic acid (5-ASA), the standard treatment for UC. However, the effectiveness of 5-ASA is not always optimal. Our study revealed that despite 5-ASA treatment, cells continued to experience excessive ferroptosis, which may hinder mucosal healing in UC and limit the success of this treatment approach in achieving disease remission. We found that combining 5-ASA with the ferroptosis inhibitor Fer-1 led to a significant inhibition of ferroptosis in macrophages present in the colon tissue, along with an increase in the proportion of M2 macrophages, suggesting that targeting ferroptosis in M2 macrophages could be a potential therapeutic strategy for alleviating UC. Our study also demonstrated that M2 macrophages are more susceptible to ferroptosis compared to M1 macrophages, and this susceptibility is associated with the activated arachidonic acid (AA) metabolism pathway mediated by ERK-cPLA2-ACSL4. Additionally, we found that the expression of cPLA2 gene pla2g4a was increased in the colon of UC patients compared to healthy controls. Furthermore, targeted metabolomics analysis revealed that the combination treatment group, as opposed to the 5-ASA treatment group, exhibited the ability to modulate AA metabolism. Overall, our findings emphasize the importance of addressing macrophage ferroptosis in order to enhance macrophage anti-inflammation, improve mucosal healing, and achieve better therapeutic outcomes for patients with UC.


Assuntos
Colite Ulcerativa , Ferroptose , Humanos , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/genética , Ferroptose/genética , Metabolismo dos Lipídeos , Macrófagos , Mesalamina
18.
Ophthalmology ; 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38372678
19.
Cell Commun Signal ; 22(1): 6, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166927

RESUMO

Ferroptosis is a newly discovered form of cell death that is featured in a wide range of diseases. Exosome therapy is a promising therapeutic option that has attracted much attention due to its low immunogenicity, low toxicity, and ability to penetrate biological barriers. In addition, emerging evidence indicates that exosomes possess the ability to modulate the progression of diverse diseases by regulating ferroptosis in damaged cells. Hence, the mechanism by which cell-derived and noncellular-derived exosomes target ferroptosis in different diseases through the system Xc-/GSH/GPX4 axis, NAD(P)H/FSP1/CoQ10 axis, iron metabolism pathway and lipid metabolism pathway associated with ferroptosis, as well as its applications in liver disease, neurological diseases, lung injury, heart injury, cancer and other diseases, are summarized here. Additionally, the role of exosome-regulated ferroptosis as an emerging repair mechanism for damaged tissues and cells is also discussed, and this is expected to be a promising treatment direction for various diseases in the future. Video Abstract.


Assuntos
Exossomos , Ferroptose , Lesão Pulmonar , Humanos , Morte Celular , NAD
20.
J Int Med Res ; 52(1): 3000605231220894, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38190847

RESUMO

OBJECTIVE: Treatment of syncope in older adults places a burden on healthcare systems. We used five risk stratification tools to predict short-term adverse outcomes in older patients with syncope. METHODS: This was a retrospective analysis of patients with syncope (age ≥60 years) in the emergency department of an urban academic hospital. The data were evaluated using the Risk Stratification of Syncope in the Emergency Department (ROSE), San Francisco Syncope Rule (SFSR), FAINT, Canadian Syncope Risk Score (CSRS), and Boston Syncope Criteria (BSC) tools. Sensitivity, specificity, accuracy, positive and negative predictive value (NPV), and positive and negative likelihood ratios of each tool were calculated and compared for adverse events within 1 month. RESULTS: In total, 221 patients (average age 75.6 years) were analyzed. Fifty-nine patients (26.7%) had experienced an adverse event within 1 month. For the ROSE, SFSR, FAINT, CSRS and BSC tools, sensitivities were 81.3%, 76.3%, 93.2%, 71.2%, and 94.9%, specificities were 88.3%, 87.7%, 56.8%, 71.6%, and 67.3%, and NPVs were 92.9%, 91.0%, 95.8%, 87.2%, and 97.3%, respectively. CONCLUSION: The five assessed tools could be useful for physicians in screening older patients with syncope for the risk of short-term adverse events, according to the patient's actual situation.


Assuntos
Síncope , Humanos , Idoso , Pessoa de Meia-Idade , Canadá , Estudos Retrospectivos , Boston , Síncope/diagnóstico , Medição de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...