Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
1.
Nature ; 600(7890): 659-663, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34937896

RESUMO

The increasing demand for next-generation energy storage systems necessitates the development of high-performance lithium batteries1-3. Unfortunately, current Li anodes exhibit rapid capacity decay and a short cycle life4-6, owing to the continuous generation of solid electrolyte interface7,8 and isolated Li (i-Li)9-11. The formation of i-Li during the nonuniform dissolution of Li dendrites12 leads to a substantial capacity loss in lithium batteries under most testing conditions13. Because i-Li loses electrical connection with the current collector, it has been considered electrochemically inactive or 'dead' in batteries14,15. Contradicting this commonly accepted presumption, here we show that i-Li is highly responsive to battery operations, owing to its dynamic polarization to the electric field in the electrolyte. Simultaneous Li deposition and dissolution occurs on two ends of the i-Li, leading to its spatial progression toward the cathode (anode) during charge (discharge). Revealed by our simulation results, the progression rate of i-Li is mainly affected by its length, orientation and the applied current density. Moreover, we successfully demonstrate the recovery of i-Li in Cu-Li cells with >100% Coulombic efficiency and realize LiNi0.5Mn0.3Co0.2O2 (NMC)-Li full cells with extended cycle life.

2.
Proc Natl Acad Sci U S A ; 120(10): e2214357120, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36848560

RESUMO

Improving Coulombic efficiency (CE) is key to the adoption of high energy density lithium metal batteries. Liquid electrolyte engineering has emerged as a promising strategy for improving the CE of lithium metal batteries, but its complexity renders the performance prediction and design of electrolytes challenging. Here, we develop machine learning (ML) models that assist and accelerate the design of high-performance electrolytes. Using the elemental composition of electrolytes as the features of our models, we apply linear regression, random forest, and bagging models to identify the critical features for predicting CE. Our models reveal that a reduction in the solvent oxygen content is critical for superior CE. We use the ML models to design electrolyte formulations with fluorine-free solvents that achieve a high CE of 99.70%. This work highlights the promise of data-driven approaches that can accelerate the design of high-performance electrolytes for lithium metal batteries.

3.
BMC Pulm Med ; 24(1): 224, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38720270

RESUMO

BACKGROUND: Simvastatin (Sim), a hydroxy-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, has been widely used in prevention and treatment of cardiovascular diseases. Studies have suggested that Sim exerts anti-fibrotic effects by interfering fibroblast proliferation and collagen synthesis. This study was to determine whether Sim could alleviate silica-induced pulmonary fibrosis and explore the underlying mechanisms. METHODS: The rat model of silicosis was established by the tracheal perfusion method and treated with Sim (5 or 10 mg/kg), AICAR (an AMPK agonist), and apocynin (a NOX inhibitor) for 28 days. Lung tissues were collected for further analyses including pathological histology, inflammatory response, oxidative stress, epithelial mesenchymal transformation (EMT), and the AMPK-NOX pathway. RESULTS: Sim significantly reduced silica-induced pulmonary inflammation and fibrosis at 28 days after administration. Sim could reduce the levels of interleukin (IL)-1ß, IL-6, tumor necrosis factor-α and transforming growth factor-ß1 in lung tissues. The expressions of hydroxyproline, α-SMA and vimentin were down-regulated, while E-cad was increased in Sim-treated rats. In addition, NOX4, p22pox, p40phox, p-p47phox/p47phox expressions and ROS levels were all increased, whereas p-AMPK/AMPK was decreased in silica-induced rats. Sim or AICAR treatment could notably reverse the decrease of AMPK activity and increase of NOX activity induced by silica. Apocynin treatment exhibited similar protective effects to Sim, including down-regulating of oxidative stress and inhibition of the EMT process and inflammatory reactions. CONCLUSIONS: Sim attenuates silica-induced pulmonary inflammation and fibrosis by downregulating EMT and oxidative stress through the AMPK-NOX pathway.


Assuntos
Proteínas Quinases Ativadas por AMP , Fibrose Pulmonar , Dióxido de Silício , Sinvastatina , Animais , Masculino , Ratos , Acetofenonas/farmacologia , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Pulmão/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , NADPH Oxidase 4/metabolismo , NADPH Oxidases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Pneumonia/induzido quimicamente , Pneumonia/prevenção & controle , Pneumonia/tratamento farmacológico , Pneumonia/metabolismo , Pneumonia/patologia , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/tratamento farmacológico , Ribonucleotídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Silicose/tratamento farmacológico , Silicose/patologia , Silicose/metabolismo , Sinvastatina/farmacologia , Fator de Crescimento Transformador beta1/metabolismo
4.
Nat Mater ; 21(4): 445-454, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35039645

RESUMO

Designing a stable solid-electrolyte interphase on a Li anode is imperative to developing reliable Li metal batteries. Herein, we report a suspension electrolyte design that modifies the Li+ solvation environment in liquid electrolytes and creates inorganic-rich solid-electrolyte interphases on Li. Li2O nanoparticles suspended in liquid electrolytes were investigated as a proof of concept. Through theoretical and empirical analyses of Li2O suspension electrolytes, the roles played by Li2O in the liquid electrolyte and solid-electrolyte interphases of the Li anode are elucidated. Also, the suspension electrolyte design is applied in conventional and state-of-the-art high-performance electrolytes to demonstrate its applicability. Based on electrochemical analyses, improved Coulombic efficiency (up to ~99.7%), reduced Li nucleation overpotential, stabilized Li interphases and prolonged cycle life of anode-free cells (~70 cycles at 80% of initial capacity) were achieved with the suspension electrolytes. We expect this design principle and our findings to be expanded into developing electrolytes and solid-electrolyte interphases for Li metal batteries.


Assuntos
Fontes de Energia Elétrica , Lítio , Eletrodos , Eletrólitos
5.
J Med Virol ; 95(9): e29112, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37750188

RESUMO

The association between HIV pre-exposure prophylaxis (PrEP) and the natural history of human papillomavirus (HPV) has not been well documented. Our objective was to evaluate the impact of PrEP on the prevalence, incidence, and clearance of anal HPV among men who have sex with men (MSM). Sexually active, HIV-negative MSM aged 18 years and older in Xinjiang, China since September 1, 2016, were enrolled in an ongoing observational cohort study of HPV. At baseline and every 6 months, an anal swab was taken to test for HPV and a questionnaire on sociodemographic characteristics and sexual behaviors was collected. Those who consented to receive PrEP were enrolled in an open-label PrEP intervention study from November 1, 2019, to June 30, 2021. This study analyzed data from participants present in the HPV cohort between November 1, 2019, and June 30, 2021. We compared the prevalence, incidence, and clearance of anal HPV between men who received PrEP (PrEP users) and those who did not (non-PrEP users), and compared men before and after initiating PrEP. We calculated prevalence ratios (PRs), incidence rate ratios (IRRs), and clearance rate ratios (CRRs) for both comparisons. Of the 870 participants present in the HPV cohort during the period between November 1, 2019, and June 30, 2021, 859 had adequate ß-globin for HPV genotype testing and were included in our study. Among them, 429 were PrEP users, while 430 were non-PrEP users. Median age was 32 years (interquartile range [IQR]: 26-38). Among PrEP users, 217 were tested for anal HPV before PrEP initiation. PrEP users had lower prevalence of HPV 45, 51, and 54 (PRs: 0.27 [95% CI: 0.09-0.80], 0.42 [0.21-0.85], and 0.41 [0.17-0.99], respectively) and lower clearance of HPV 16 (CRR: 0.31 [0.10-0.91]) compared with non-PrEP users. PrEP users exhibited lower prevalence of HPV 51 (PR: 0.31 [0.12-0.84]), lower incidence of HPV 6, 11, 16, 39 and 61 (IRRs: 0.34 [0.13-0.90], 0.26 [0.08-0.87], 0.44 [0.21-0.91], 0.21 [0.05-0.93], and 0.19 [0.04-0.82], respectively), as well as higher clearance of HPV 52 (CRR: 2.17 [1.08-4.35]) after PrEP initiation. PrEP use may lower the risk of HPV infection among MSM in Xinjiang, China. Our findings further extend the knowledge of the impact of PrEP on sexually transmitted infections.


Assuntos
Infecções por HIV , Infecções por Papillomavirus , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Masculino , Humanos , Adulto , Papillomavirus Humano , Incidência , Homossexualidade Masculina , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/prevenção & controle , Prevalência , Estudos de Coortes , Papillomaviridae/genética , China/epidemiologia , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle
6.
Appl Opt ; 62(3): 735-744, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36821279

RESUMO

In this paper, a random forest regression (RFR) rain size characterization method based on a laser ultrasound technique is investigated to predict the grain size of titanium alloy (Ti-6Al-4V). The longitudinal wave velocity of the ultrasound signal and the attenuation coefficient at different frequencies are used as the input and the grain size is used as the output. An RFR algorithm was used to develop a grain size prediction model. Meanwhile, the grain size calculation model based on conventional scattering attenuation was established by calibrating the n value in the classical scattering theory using the attenuation coefficients at different frequencies of ultrasonic signals. The results show that the RFR algorithm is feasible for the grain size characterization of titanium alloys.

7.
J Genet Couns ; 2023 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-37864575

RESUMO

Due to a lack of ancestry-matched, functional, and segregation data, Asians have a higher rate of receiving a variant of uncertain significance (VUS) result following panel testing. Managing VUS results presents challenges, as it often leads to increased anxiety and distress among cancer patients undergoing genetic testing. This exploratory study aims to investigate the experience of Asian cancer patients upon receiving a VUS result. A qualitative, semi-structured interview study was conducted, involving cancer patients who had received a VUS result through the Cancer Genetics Service of the National Cancer Centre Singapore. Twenty participants were interviewed, and their responses were transcribed and analyzed using thematic analysis to identify key themes. Thematic analysis revealed five major themes: (1) VUS results are interpreted as uncertain outcomes; (2) a VUS result provides relief and prompts positive behavioral adjustments; (3) patients employ fatalism and religion as coping mechanisms to navigate uncertainty; (4) genetic counselors, family, and the community offer reassurance and support; (5) patients value updates on variant classifications for future management. While this novel study provides unique insights into the perspectives of Asian patients who receive VUS results, it also highlights patients' effective management of VUS results and uncertainty, which has implications for improving counseling practices in Asia. Emphasis must be placed on accurate interpretation and clear communication of VUS results to dispel the possibility of misconceptions, misdiagnosis, and mismanagement in cancer care.

8.
Proc Natl Acad Sci U S A ; 117(47): 29453-29461, 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33168752

RESUMO

Rechargeability and operational safety of commercial lithium (Li)-ion batteries demand further improvement. Plating of metallic Li on graphite anodes is a critical reason for Li-ion battery capacity decay and short circuit. It is generally believed that Li plating is caused by the slow kinetics of graphite intercalation, but in this paper, we demonstrate that thermodynamics also serves a crucial role. We show that a nonuniform temperature distribution within the battery can make local plating of Li above 0 V vs. Li0/Li+ (room temperature) thermodynamically favorable. This phenomenon is caused by temperature-dependent shifts of the equilibrium potential of Li0/Li+ Supported by simulation results, we confirm the likelihood of this failure mechanism during commercial Li-ion battery operation, including both slow and fast charging conditions. This work furthers the understanding of nonuniform Li plating and will inspire future studies to prolong the cycling lifetime of Li-ion batteries.

9.
Hered Cancer Clin Pract ; 21(1): 5, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37046302

RESUMO

BACKGROUND: Although Singapore is one of the highest vaccinated countries in the world, vaccine hesitancy remains in a subpopulation, including individuals with cancer predisposition syndromes. At the Cancer Genetics Service National Cancer Centre Singapore, we see patients with germline genetic alterations, most being BRCA1/2 pathogenic/likely pathogenic variant (PV/LPV) carriers. While reported safe for cancer patients, there are limited studies addressing the safety profile and outcomes of COVID-19 vaccination among individuals with germline PV/LPV in cancer predisposition genes such as BRCA1/2. This study aims to evaluate the outcomes of COVID-19 vaccination among germline PV/LPV carriers in BRCA1/2. METHODS: We conducted a phone call survey of COVID-19 vaccination uptake and toxicity in a prospective cohort of 189 participants with germline BRCA1/2 PV/LPV between 1st Sept 2021 and 30th Sept 2021. We collected demographics data including gender, race, age, history of cancer, types of cancer, and number of cancers. Statistical difference in baseline demographics between responders with history of cancer and those without were assessed using Chi-square, Fisher's exact and independent t-test analysis. Logistic regression was used to evaluate effect of demographics on the occurrence of post-vaccination side effects. RESULTS: Among 189 BRCA1/2 PV/LPV carriers responded, 97 carried PV/LPV in BRCA1 and 92 in BRCA2. Majority were vaccinated (89.5%) and had completed the two-dose vaccine schedule, with 7 (4.1%) received only one dose. The most common post-vaccination side effects was myalgia (56.5%) followed by fever (40.2%), headache (16.3%) and fatigue (11.2%). There were no major severe side events. Evaluation by logistic regression showed that the occurrence of side effects was not affected by PV/LPV gene (BRCA1 or BRCA2), gender, race, age or history of cancer. CONCLUSION: The post-vaccination side effects profile among individuals with germline PV/LPV in BRCA1/2 is consistent with the Singaporean general population, hence recommendations for COVID-19 vaccination for these individuals should not differ from non-carriers and should be encouraged by their healthcare providers.

10.
Altern Ther Health Med ; 29(3): 26-31, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36735712

RESUMO

Objective: To explore the key sites in which L-arginine affects the expression of human coagulation factor VIII gene, and to create new drug targets for the treatment of hemophilia. Methods: A total of 5 human FVIII genes (A1, A2, A3, C1 and C2) with B domain deletion were transfected into human umbilical vein endothelial cells (HUVECs) as promoters. Run-on assay and ELISA analysis were performed to observe the driving effect of each domain gene on chloramphenicol acetyl transferase (CAT) gene transcription and expression, and the effect of L-arginine on each promoter. Results: In co-culture with L-arginine, transcriptional expression of the CAT gene was not detected in the PCAT3-Basic group (negative control without promoters), PA3-CAT3-Enhancer group or PC1-CAT3-Enhancer group. The transcriptional expression of CAT gene in the PCAT3-Control group (positive control with promoters) and PA1-CAT3-Enhancer group was unchanged compared with the non-L-arginine intervention, while the transcriptional expression of CAT gene in the PA2-CAT3-Enhancer group was significantly enhanced. Conclusions: A1 and A2 domain genes had promoter function and could initiate the transcription and expression of CAT gene, but A3, C1 and C2 domain genes could not. Moreover, L-arginine can significantly enhance transcription and expression of human coagulation factor VIII via A2 domain.


Assuntos
Células Endoteliais , Fator VIII , Humanos , Fator VIII/genética , Fator VIII/metabolismo , Células Endoteliais/metabolismo , Arginina/farmacologia
11.
Nano Lett ; 22(20): 8224-8232, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36214378

RESUMO

Poor fast-charge capabilities limit the usage of rechargeable Li metal anodes. Understanding the connection between charging rate, electroplating mechanism, and Li morphology could enable fast-charging solutions. Here, we develop a combined electroanalytical and nanoscale characterization approach to resolve the current-dependent regimes of Li plating mechanisms and morphology. Measurement of Li+ transport through the solid electrolyte interphase (SEI) shows that low currents induce plating at buried Li||SEI interfaces, but high currents initiate SEI-breakdown and plating at fresh Li||electrolyte interfaces. The latter pathway can induce uniform growth of {110}-faceted Li at extremely high currents, suggesting ion-transport limitations alone are insufficient to predict Li morphology. At battery relevant fast-charging rates, SEI-breakdown above a critical current density produces detrimental morphology and poor cyclability. Thus, prevention of both SEI-breakdown and slow ion-transport in the electrolyte is essential. This mechanistic insight can inform further electrolyte engineering and customization of fast-charging protocols for Li metal batteries.

12.
Acc Chem Res ; 54(18): 3505-3517, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34278783

RESUMO

The development of clean energy generation, transmission, and distribution technology, for example, high energy density batteries and high efficiency solar cells, is critical to the progress toward a sustainable future. Such advancement in both scientific understanding and technological innovations entail an atomic- and molecular-resolution understanding of the key materials and fundamental processes governing the operation and failure of the systems. These dynamic processes span multiple length and time scales bridging materials and interfaces involved across the entire device architecture. However, these key components are often highly sensitive to air, moisture, and electron-beam radiation and therefore remain resistant to conventional nanoscale interrogation by electron-optical methods, such as high-resolution (scanning) transmission electron microscopy and spectroscopy.Fortunately, the rapid progress in cryogenic electron microscopy (cryo-EM) for physical sciences starts to offer researchers new tools and methods to probe these otherwise inaccessible length scales of components and phenomena in energy science. Specifically, weakly bonded and reactive materials, interfaces and phases that typically degrade under high energy electron-beam irradiation and environmental exposure can potentially be protected and stabilized by cryogenic methods, bringing up thrilling opportunities to address many crucial yet unanswered questions in energy science, which can eventually lead to new scientific discoveries and technological breakthroughs.Thus, in this Account, we aim to highlight the significance of cryo-EM to energy related research and the impactful results that can be potentially spawned from there. Due to the limited space, we will mainly review representative examples of cryo-EM methodology for lithium (Li)-based batteries, hybrid perovskite solar cells, and metal-organic-frameworks, which have shown great promise in revealing atomic resolution of both structural and chemical information on the sensitive yet critical components in these systems. We will first emphasize the application of cryo-EM to resolve the nanostructure and chemistry of solid-electrolyte interphases, cathode-electrolyte interphase, and electrode materials in batteries to reflect how cryo-EM could inspire rational materials design and guide battery research toward practical applications. We then discuss how cryo-EM helped to reveal guest intercalation chemistry in weakly bonded metal-organic-frameworks to develop a complete picture of host-guest interaction. Next, we summarize efforts in hybrid perovskite materials for solar cells where cryo-EM preserved the volatile organic molecules and protected perovskites from any air or moisture contamination. Finally, we conclude with perspectives and brief discussion on future directions for cryo-EM in energy and materials science.

13.
BMC Gastroenterol ; 22(1): 527, 2022 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-36528595

RESUMO

BACKGROUND AND AIMS: Effective traction is an important prerequisite for successful endoscopic submucosal dissection (ESD). The combined orthodontic rubber band (ORB) and clip method was effective in colorectal cancer ESD. To date, the method was not reported in gastric ESD. This study aimed to investigate its efficacy and safety for gastric neoplasms ESD. METHODS: We retrospectively analyzed data of 118 patients with gastric neoplasms treated by ESD from November 2020 to April 2022, 43 by ORB-ESD and 75 by the conventional ESD. The primary outcome measure was the ESD procedure time. Clinical data on efficacy and safety were also collected and analyzed. Propensity score matching (PSM) matched the patients in both groups. RESULTS: PSM successfully matched 31 pairs of patients. The ORB-ESD operation time was shorter (median [interquartile range], 35 [30-48] vs. 49 [40-70] min, P < 0.001) and dissection speed was higher (median [interquartile range], 22.6 [14.4-29.3] vs. 13.5 [9.6-17.9] mm2/min, P < 0.001) than in the conventional ESD. The groups were similar in muscular injury rate, frequency and time of use of thermal hemostatic forceps, postoperative adverse events, en bloc resection, and R0 resection rate (P > 0.05). CONCLUSIONS: Compared to the conventional ESD, ORB-ESD significantly reduced the procedure time and increased the dissection speed, proving beneficial to gastric ESD.


Assuntos
Ressecção Endoscópica de Mucosa , Neoplasias Gástricas , Humanos , Ressecção Endoscópica de Mucosa/efeitos adversos , Ressecção Endoscópica de Mucosa/métodos , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/etiologia , Estudos Retrospectivos , Instrumentos Cirúrgicos , Dissecação/efeitos adversos , Dissecação/métodos , Resultado do Tratamento
14.
Acta Haematol ; 145(5): 517-528, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35598597

RESUMO

BACKGROUND: The potential signaling pathway of TSA suppressing TF expression induced by thrombin was unknown. Thus, the transcription of TF in HUVECs and the expressions of DCF, phospho-p38 MAPK, NADPH oxidase 4, PAR-1, and NF-κB were detected in our study. METHODS: HUVECs were randomly divided into control group, thrombin-treated group (with 5 U/mL of thrombin), and 4 TSA-treated groups (with 5 U/mL of thrombin plus TSA with 4 different concentrations of 1 µg/mL, 10 µg/mL, 100 µg/mL, and 1 mg/mL, respectively). RESULTS: After incubation with thrombin for 6 h at 37°C, the results showed increased TF mRNA, TF procoagulant activity, and antigen of TF in HUVECs of thrombin-treated group (p < 0.01); however, they were restored by TSA in a dose-dependent manner (p < 0.01). In addition, reactive oxygen species (ROS), phospho-p38 MAPK, NADPH oxidase 4, NF-κB, and PAR-1 expressed more intensively, and phosphorylated Akt decreased obviously in HUVECs after thrombin stimulation (p < 0.01); however, they were reversed to different extents by TSA in a dose-dependent manner (p < 0.01). CONCLUSIONS: Study suggests that TSA inhibits TF expression induced by thrombin in cultured HUVECs, and the potential signaling pathway of which is TSA interrupts the activation of PAR-1 and NADPH oxidase as well as derivative ROS generation, thereafter suppresses the activation of NF-κB, the upstream signal molecule of TF, via hampering phosphorylation of p38 MAPK and dephosphorylation of Akt, and finally inhibits thrombin-induced TF overexpression.


Assuntos
Trombina , Tromboplastina , Humanos , Abietanos , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana/metabolismo , NADPH Oxidase 4/metabolismo , NADPH Oxidases/metabolismo , NF-kappa B/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais , Trombina/metabolismo , Trombina/farmacologia , Tromboplastina/genética , Tromboplastina/metabolismo
15.
Acta Haematol ; 145(3): 318-325, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34375974

RESUMO

BACKGROUND: Adult chronic idiopathic thrombocytopenic purpura (ITP) is a chronic and usually lifelong hemorrhagic disorder in which enhanced platelet destruction and -weakened platelet production lead to thrombocytopenia. In this study, the p38 mitogen-activated protein kinase (p38-MAPK), early growth response 1 (EGR-1), p53, Bcl-xL, Bak, Bax, and reactive oxygen species (ROS) in platelets from adult patients with chronic ITP were investigated. METHODS: Platelets were isolated from blood samples collected from 20 adult patients with chronic ITP and 20 healthy volunteers. p38-MAPK, EGR-1, p53, Bcl-xL, Bak, Bax, and ROS were determined by flow cytometry, and the results were analyzed by EXPO32 ADC. RESULTS: Flow cytometry showed the expression levels of p38-MAPK (61.66 ± 19.38% vs. 27.52 ± 14.34%), EGR-1 (62.22 ± 20.48% vs. 9.05 ± 5.79%), p53 (56.82 ± 20.07% vs. 4.35 ± 2.04%), Bak (39.86 ± 11.45% vs. 20.82 ± 11.85%), Bax (36.85 ± 15.99% vs. 6.69 ± 5.01%), and ROS (19.98 ± 1.47% vs. 1.29 ± 0.10%) were all elevated (p < 0.05 compared with healthy volunteers). In addition, pro-survival Bcl-xL (5.38 ± 1.52% vs. 21.20 ± 6.04%) was decreased markedly in platelets from adult patients with chronic ITP (p < 0.05 compared with healthy volunteers). CONCLUSIONS: Our findings reveal that platelets in adults with chronic ITP display a proapoptotic gene expression phenotype, based on the enhanced expression of p38-MAPK, EGR-1, p53, Bak, Bax, and ROS, and attenuated expression of Bcl-xL, suggesting increased sensitivity toward apoptosis.


Assuntos
Plaquetas , Púrpura Trombocitopênica Idiopática , Apoptose/genética , Plaquetas/metabolismo , Humanos , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53 , Proteína X Associada a bcl-2/genética
16.
Acta Haematol ; 144(5): 551-559, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33849009

RESUMO

OBJECTIVE: The objective of this study was to determine the expression of G protein-coupled receptors (GPCRs) in platelets from adult patients with chronic immune thrombocytopenic purpura (ITP). METHODS: Peripheral blood samples were collected from 40 patients with chronic ITP in the Second Affiliated Hospital of Shantou University Medical College, and 40 peripheral blood samples from healthy volunteers were collected; expressions of the adenosine diphosphate receptors (P2Y1 and P2Y12), alpha-2A adrenergic receptor (α2A-AR), and thromboxane A2 receptor (TP) in platelets were detected by flow cytometry. Gα protein, protease-activated receptor 1 (PAR1), and protease-activated receptor 4 (PAR4) were analyzed by Western blot and analyzed statistically. RESULTS: Flow cytometry measurements of mean fluorescence intensities showed platelets from patients with chronic ITP, compared to healthy individuals, had significantly higher levels of P2Y1 (31.4 ± 2.2 vs. 7.8 ± 0.8), P2Y12 (29.6 ± 2.1 vs. 7.2 ± 1.3), α2A-AR (25.8 ± 2.9 vs. 9.8 ± 0.9), and TP (39.8 ± 3.1 vs. 4.7 ± 0.6) (all p < 0.01). Similarly, integrated optical density analysis of Western blots showed that platelets from patients with chronic ITP had significantly higher levels of Gα (1046.3 ± 159.96 vs. 254.49 ± 39.51), PAR1 (832.98 ± 98.81 vs. 203.92 ± 27.47), and PAR4 (1518.80 ± 272.45 vs. 431.27 ± 41.86) (all p < 0.01). CONCLUSION: Expression of GPCRs is increased in platelets from patients with chronic ITP, suggesting that platelets of chronic ITP may participate in the complicated biological process by means of GPCR-mediated signaling pathways.


Assuntos
Plaquetas/metabolismo , Regulação da Expressão Gênica , Púrpura Trombocitopênica Idiopática/sangue , Receptores Acoplados a Proteínas G/biossíntese , Transdução de Sinais , Adulto , Plaquetas/patologia , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Púrpura Trombocitopênica Idiopática/patologia
17.
Nano Lett ; 20(12): 8719-8724, 2020 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-33201720

RESUMO

Gas-phase heterogeneous catalysis is a process spatially constrained on the two-dimensional surface of a solid catalyst. Here, we introduce a new toolkit to open up the third dimension. We discovered that the activity of a solid catalyst can be dramatically promoted by covering its surface with a nanoscale-thin layer of liquid electrolyte while maintaining efficient delivery of gas reactants, a strategy we call three-phase catalysis. Introducing the liquid electrolyte converts the original surface catalytic reaction into an electrochemical pathway with mass transfer facilitated by free ions in a three-dimensional space. We chose the oxidation of formaldehyde as a model reaction and observed a 25000-times enhancement in the turnover frequency of Pt in three-phase catalysis as compared to conventional heterogeneous catalysis. We envision three-phase catalysis as a new dimension for catalyst design and anticipate its applications in more chemical reactions from pollution control to the petrochemical industry.

18.
Nano Lett ; 20(7): 5496-5503, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32515973

RESUMO

Solid-state Li-S batteries are attractive due to their high energy density and safety. However, it is unclear whether the concepts from liquid electrolytes are applicable in the solid state to improve battery performance. Here, we demonstrate that the nanoscale encapsulation concept based on Li2S@TiS2 core-shell particles, originally developed in liquid electrolytes, is effective in solid polymer electrolytes. Using in situ optical cell and sulfur K-edge X-ray absorption, we find that polysulfides form and are well-trapped inside individual particles by the nanoscale TiS2 encapsulation. This TiS2 encapsulation layer also functions to catalyze the oxidation reaction of Li2S to sulfur, even in solid-state electrolytes, proven by both experiments and density functional theory calculations. A high cell-level specific energy of 427 W·h·kg-1 is achieved by integrating the Li2S@TiS2 cathode with a poly(ethylene oxide)-based electrolyte and a lithium metal anode. This study points to the fruitful direction of borrowing concepts from liquid electrolytes into solid-state batteries.

19.
Exp Lung Res ; 46(3-4): 98-108, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32164467

RESUMO

Purpose: Airway remodeling is one of the features of severe asthma. Previous study shows that IL-27 inhibits airway inflammation in asthmatic mice. However, the role of IL-27 on airway remodeling in OVA-induced asthmatic mice and its possible mechanism remain unclear. Methods: We established an ovalbumin (OVA)-induced asthmatic mice model. IL-27 were preventative administered to OVA-induced asthmatic mice. The total cells in Bronchoalveolar lavage fluid (BALF) and Airway hyperresponsiveness (AHR) were measured. The lung tissues were performed by Hematoxylin and eosin (HE) staining to estimate the pathological changes. Masson staining was used to observe the collagen deposition area. The expression of α-smooth muscle actin (α-SMA) and Type I collagen was measured by immunohistochemistry, western blot, and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Additionally, western blot was also used to measure the expression of phosphorylated-Akt (p-Akt) in each group. Results: IL-27 group showed significant inhibitory effect on the α-SMA and Type I collagen. The expression of p-Akt in the tissues of asthma model was increased and inhibited by IL-27. Conclusions: IL-27 can alleviate airway remodeling in OVA-induced asthmatic mice, and the mechanism may relate to PI3K/Akt pathway.


Assuntos
Remodelação das Vias Aéreas/efeitos dos fármacos , Asma/tratamento farmacológico , Interleucina-27/uso terapêutico , Pulmão/efeitos dos fármacos , Animais , Asma/metabolismo , Avaliação Pré-Clínica de Medicamentos , Feminino , Interleucina-27/farmacologia , Pulmão/metabolismo , Camundongos Endogâmicos BALB C , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
20.
Nano Lett ; 19(2): 1326-1335, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30676759

RESUMO

Lithium (Li) metal has long been considered the "holy grail" of battery anode chemistry but is plagued by low efficiency and poor safety due to its high chemical reactivity and large volume fluctuation, respectively. Here we introduce a new host of wrinkled graphene cage (WGC) for Li metal. Different from recently reported amorphous carbon spheres, WGC show highly improved mechanical stability, better Li ion conductivity, and excellent solid electrolyte interphase (SEI) for continuous robust Li metal protection. At low areal capacities, Li metal is preferentially deposited inside the graphene cage. Cryogenic electron microscopy characterization shows that a uniform and stable SEI forms on the WGC surface that can shield the Li metal from direct exposure to electrolyte. With increased areal capacities, Li metal is plated densely and homogeneously into the outer pore spaces between graphene cages with no dendrite growth or volume change. As a result, a high Coulombic efficiency (CE) of ∼98.0% was achieved under 0.5 mA/cm2 and 1-10 mAh/cm2 in commercial carbonate electrolytes, and a CE of 99.1% was realized with high-concentration electrolytes under 0.5 mA/cm2 and 3 mAh/cm2. Full cells using WGC electrodes with prestored Li paired with Li iron phosphate showed greatly improved cycle lifetime. With 10 mAh/cm2 Li metal deposition, the WGC/Li composite anode was able to provide a high specific capacity of ∼2785 mAh/g. With its roll-to-roll compatible fabrication procedure, WGC serves as a highly promising material for the practical realization of Li metal anodes in next-generation high energy density secondary batteries.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa