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1.
Proc Natl Acad Sci U S A ; 120(2): e2213528120, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36595700

RESUMO

Flow batteries are a promising energy storage solution. However, the footprint and capital cost need further reduction for flow batteries to be commercially viable. The flow cell, where electron exchange takes place, is a central component of flow batteries. Improving the volumetric power density of the flow cell (W/Lcell) can reduce the size and cost of flow batteries. While significant progress has been made on flow battery redox, electrode, and membrane materials to improve energy density and durability, conventional flow batteries based on the planar cell configuration exhibit a large cell size with multiple bulky accessories such as flow distributors, resulting in low volumetric power density. Here, we introduce a submillimeter bundled microtubular (SBMT) flow battery cell configuration that significantly improves volumetric power density by reducing the membrane-to-membrane distance by almost 100 times and eliminating the bulky flow distributors completely. Using zinc-iodide chemistry as a demonstration, our SBMT cell shows peak charge and discharge power densities of 1,322 W/Lcell and 306.1 W/Lcell, respectively, compared with average charge and discharge power densities of <60 W/Lcell and 45 W/Lcell, respectively, of conventional planar flow battery cells. The battery cycled for more than 220 h corresponding to >2,500 cycles at off-peak conditions. Furthermore, the SBMT cell has been demonstrated to be compatible with zinc-bromide, quinone-bromide, and all-vanadium chemistries. The SBMT flow cell represents a device-level innovation to enhance the volumetric power of flow batteries and potentially reduce the size and cost of the cells and the entire flow battery.


Assuntos
Líquidos Corporais , Brometos , Tamanho Celular , Fibras na Dieta , Zinco
2.
Acc Chem Res ; 56(21): 2944-2953, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37856878

RESUMO

ConspectusHere, we discuss recent advances and pressing challenges in achieving sustainable urea synthesis. Urea stands out as the most prevalent nitrogen-based fertilizer used across the globe, making up over 50% of all manufactured fertilizers. Historically, the Bosch-Meiser process has been the go-to chemical manufacturing method for urea production. This procedure, characterized by its high-temperature and high-pressure conditions, reacts ammonia with carbon dioxide to form ammonium carbamate. Subsequently, this ammonium carbamate undergoes dehydration, facilitated by heat, producing solid urea. A concerning aspect of this method is its dependency on fossil fuels, as nearly all the process heat comes from nonrenewable sources. Consequently, the Bosch-Meiser process leaves behind a considerable carbon footprint. Current estimates predict that unchecked, carbon emissions from urea production alone might skyrocket, reaching a staggering 286 MtCO2,eq/yr by 2050. Such projections paint a clear picture regarding the necessity for more eco-friendly, sustainable urea production methods. Recently, the scientific community has shown growing interest in forming C-N bonds using alternative methods. Shifting toward photochemical or electrochemical processes, as opposed to traditional thermal-based processes, promises the potential for complete electrification of urea synthesis. This shift toward process electrification is not just an incremental change; it represents a groundbreaking advancement, the first of many steps, toward achieving deep decarbonization in the chemical manufacturing sector. Since the turn of 2020, there has been a surge in research focusing on photochemical and electrochemical urea synthesis. These methods capitalize on co-reduction of carbon dioxide with nitrogenous reactants like NOx and N2. Despite the progress, there are significant challenges that hinder these processes from reaching their full potential. In this comprehensive review, we shed light on the advances made in electrified C-N bond formation. More importantly, we focus on the invaluable insights gathered over the years, especially concerning catalytic reaction mechanisms. We have dedicated a section to underline key focal areas for up-and-coming research, emphasizing catalyst, electrolyte, and reactor design. It is undeniable that catalyst design remains at the heart of the matter, as managing the co-reduction of two distinct reactants (CO2 and nitrogenous species) is complex. This process results in a myriad of intermediates, which must be adeptly managed to both maintain catalyst activity and avoid catalyst deactivation. Moreover, the electrolytes play a pivotal role, essentially dictating the creation of optimal microenvironments that drive reaction selectivity. Finally, reactor engineering stands out as crucial to ensure optimal mass transport for all involved reactants and subsequent products. We touch upon the broader environmental ramifications of urea production and bring to light potential obstacles for alternative synthesis routes. A notable mention is the urgency of accelerating the uptake and large-scale implementation of renewable energy sources.

3.
Int J Mol Sci ; 25(20)2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39456722

RESUMO

Influenza A virus (IAV) is known for causing seasonal epidemics ranging from flu to more severe outcomes like pneumonia, cytokine storms, and acute respiratory distress syndrome. The innate immune response and inflammasome activation play pivotal roles in sensing, preventing, and clearing the infection, as well as in the potential exacerbation of disease progression. This study examines the complex relationships between donor-specific characteristics and cytokine responses during H3N2 IAV infection using an ex vivo model. At 24 h post infection in 31 human lung explant tissue samples, key cytokines such as interleukin (IL)-6, IL-10, tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) were upregulated. Interestingly, a history of lung cancer did not impact the acute immune response. However, cigarette smoking and programmed death-ligand 1 (PD-L1) expression on macrophages significantly increased IL-2 levels. Conversely, age inversely affected IL-4 levels, and diabetes mellitus negatively influenced IL-6 levels. Additionally, both diabetes mellitus and programmed cell death protein 1 (PD-1) expression on CD3+/CD4+ T cells negatively impacted TNF-α levels, while body mass index was inversely associated with IFN-γ production. Toll-like receptor 2 (TLR2) expression emerged as crucial in mediating acute innate and adaptive immune responses. These findings highlight the intricate interplay between individual physiological traits and immune responses during influenza infection, underscoring the importance of tailored and personalized approaches in IAV treatment and prevention.


Assuntos
Citocinas , Vírus da Influenza A Subtipo H3N2 , Influenza Humana , Humanos , Citocinas/metabolismo , Vírus da Influenza A Subtipo H3N2/imunologia , Influenza Humana/imunologia , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Pulmão/imunologia , Pulmão/virologia , Pulmão/metabolismo , Pulmão/patologia , Idoso , Macrófagos/imunologia , Macrófagos/metabolismo , Imunidade Inata
4.
Faraday Discuss ; 243(0): 378-387, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37264921

RESUMO

There are numerous reports of photo(electro)catalysts demonstrating activity for nitrogen reduction to ammonia and a few reports of photo(electro)catalysts demonstrating activity for nitrogen oxidation to nitric acid. However, progress in advancing solar-to-fertilizer applications is slow, due in part to the pace of catalyst screening. Most evaluations of photo(electro)catalysts activity occur using batch reactors. This is because common product analyses require accumulation of ammonia or nitric acid in the reactor to overcome instrument detection limits. The primary aim here is to examine the use of an electroanalytical method, rotating ring disk electrode voltammetry (RRDE), to detect ammonia produced by a nitrogen fixing photo(electro)catalyst. To examine the potential for RRDE, we investigated a photo(electro)catalyst known to reduce nitrogen to ammonia (titania), while varying the applied electrochemical potential and degree of illumination on the disk. We show that the observed ammonia oxidation at the ring electrode corresponds strongly with ammonia measurements obtained from the bulk electrolyte. Indicating that RRDE may be effective for catalyst screening. The chief limitation of this approach is the need for an alkaline electrolyte. In addition, this approach does not rule out the presence of adventitious ammonia.

5.
BMC Ophthalmol ; 23(1): 154, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37041510

RESUMO

PURPOSE: To identify the characteristics of asymptomatic meibomian gland dysfunction (MGD), symptomatic MGD, and MGD coexisting with dry eye disease (DED). METHODS: This cross sectional study enrolled a total of 153 eyes of 87 MGD patients. Participants filled in ocular surface disease index (OSDI) questionnaires. Age, gender, Schirmer's test, meibomian gland (MG) related parameters, lipid layer thickness (LLT) and blinking were compared among patients with asymptomatic MGD, symptomatic MGD, and MGD with DED. Multivariate regression was used to analyze the significant factor of DED in MGD. Spearman's rank correlation analysis was used to evaluate the association between the significant factors and MG function. RESULTS: There was no difference in age, Schirmer's test, lid changes, MG secretion, and MG morphology among three groups. The OSDI of asymptomatic MGD, symptomatic MGD and MGD coexisting with DED were 8.5 ± 2.9, 28.5 ± 12.8 and 27.9 ± 10.5, respectively. Patients with MGD coexisting with DED exhibited more frequent eye blinking than that of patients with asymptomatic MGD (8.1 ± 4.1 vs. 6.1 ± 3.5 blinks/20 sec, P = 0.022), and reduced LLT than that of patients with asymptomatic MGD (68.6 ± 17.2 vs. 77.6 ± 14.5 nm, P = 0.010) and symptomatic MGD (78.0 ± 17.1 nm, P = 0.015). Multivariate analysis identified LLT (per nm, OR = 0.96, 95% CI = 0.93-0.99, P = 0.002) as a significant factor associated with DED development in MGD. The number of expressible MG was positively correlated with LLT (Spearman's correlation coefficient = 0.299, P = 0.016) but negatively correlated with the number of blinking (Spearman's correlation coefficient = -0.298, P = 0.016) in MGD patients with DED, and these findings were not identified in those without DED. CONCLUSIONS: Asymptomatic MGD, symptomatic MGD, and MGD coexisting with DED share similar characteristics, including meibum secretion and morphology, but MGD patients coexisting with DED exhibited significantly reduced LLT.


Assuntos
Síndromes do Olho Seco , Disfunção da Glândula Tarsal , Humanos , Estudos Transversais , Glândulas Tarsais , Piscadela
6.
Toxicol Appl Pharmacol ; 435: 115847, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34963561

RESUMO

Although some studies have hinted at the therapeutic potential of daunorubicin (DNR) in chronic myeloid leukemia (CML), the mechanism by which DNR induces CML cell death is unclear. Therefore, this study aimed to investigate DNR-induced cell death signaling pathways in CML cell lines K562 and KU812. DNR-triggered apoptosis in K562 cells was characterized by inhibition of MCL1 expression, while restoration of MCL1 expression protected K562 cells from DNR-mediated cytotoxicity. In addition, DNR induced NOX4-dependent ROS production, leading to the activation of p38 MAPK and inactivation of Akt and ERK. Activated p38 MAPK stimulated protein phosphatase 2A-dependent dephosphorylation of CREB. Since Akt-mediated activation of ERK reduced ß-TrCP mRNA stability, the inactivation of Akt-ERK axis increased ß-TrCP expression, which in turn promoted proteasomal degradation of Sp1. Inhibition of CREB phosphorylation and Sp1 expression simultaneously reduced MCL1 transcription and protein expression. DNR-induced MCL1 suppression was not reliant on its ability to induce DNA damage. In addition, DNR induced the expression of drug exporter ABCB1 in K562 cells through the p38 MAPK/NFκB-mediated pathway, while imatinib or ABT-199 inhibited the DNR-induced effect. The combination of imatinib or ABT-199 with DNR showed synergistic cytotoxicity in K562 cells by increasing intracellular DNR retention. Cumulatively, our data indicate that DNR induces MCL1 downregulation in K562 cells by promoting p38 MAPK-mediated dephosphorylation of CREB and inhibiting the Akt-ERK axis-mediated Sp1 protein stabilization. Furthermore, experimental evidence indicates that DNR-induced death of KU812 cells occurs through a similar pathway.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Daunorrubicina/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/biossíntese , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , NF-kappa B/metabolismo , Fator de Transcrição Sp1/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Mesilato de Imatinib/farmacologia , Células K562 , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , NADPH Oxidase 4/metabolismo , NF-kappa B/genética , Espécies Reativas de Oxigênio/metabolismo , Sulfonamidas/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
7.
J Formos Med Assoc ; 121(8): 1397-1405, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34674904

RESUMO

BACKGROUND/PURPOSE: Taiwan Drug-Injury Relief System (TDRS) has been implemented since 1999. More than 60% of the approved applications were associated with severe cutaneous adverse reactions (SCARs). Studies assessing SCARs using real-world evidence are very limited. TDRS offers abundant case information as a source of real-world evidence to investigate the characteristics of SCARs in Taiwan. The purpose of this study is to understand the trends and characteristics of SCARs in Taiwan. METHODS: Applications from Drug-Injury Relief Database (TDRD) from 1999 to 2016 were retrospectively analyzed. RESULTS: A declining trend in SCARs application was noticed after 2012, and 952 applications of SCARs were identified. The most common subtypes of SCARs were SJS/TEN (n = 455/206), DRESS (n = 228), GBFDE (n = 34) and AGEP (n = 18). The most common culprit drugs were allopurinol, carbamazepine, phenytoin, diclofenac and lamotrigine for SJS/TEN; allopurinol, phenytoin, co-trimoxazole, carbamazepine and phenobarbital for DRESS; mefenamic acid for GBFDE; non-steroidal anti-inflammatory drugs (NSAIDs) and beta-lactam antibacterials for AGEP. The proportions of mortality cases were 28.9% for SJS/TEN; 36% for DRESS; 11.8% for GBFDE and 5.6% for AGEP. The mean latent period of SJS/TEN, DRESS, GBFDE and AGEP were 21.8 days, 29.2 days, 3.3 days and 6.7 days, respectively. CONCLUSION: The approved drug-injury relief applications associated with SCARs were mainly SJS, TEN and DRESS. The most common culprit drugs were antiepileptics, antibacterials, antigout agents, and NSAIDs. The latent periods showed some distinct features for different types of SCARs. In light of the high mortality rate, public awareness and vigilance of SCARs are crucial for the patient safety.


Assuntos
Fenitoína , Síndrome de Stevens-Johnson , Alopurinol/efeitos adversos , Antibacterianos/efeitos adversos , Anti-Inflamatórios não Esteroides/efeitos adversos , Anticonvulsivantes/efeitos adversos , Carbamazepina/efeitos adversos , Cicatriz/induzido quimicamente , Humanos , Estudos Retrospectivos , Síndrome de Stevens-Johnson/tratamento farmacológico , Síndrome de Stevens-Johnson/etiologia , Taiwan/epidemiologia
8.
Sensors (Basel) ; 22(13)2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35808288

RESUMO

Scientific injection molding technologies involve the integration and collaboration of cyber-physical systems and smart manufacturing. In order to achieve adaptive process control and production optimization, injection molding systems with real-time sensing have gradually become the development- and application-trend of smart injection molding. At the same time, this technology is a highly non-linear process in which many factors affect the product quality during long-run fabrication processes. Therefore, in order to grasp changes in the characteristics of plastic materials and product quality monitoring, the injection process has become an important research topic. We installed sensors in the molding machine (injection barrel, nozzle, and mold-cavity) to collect the melting pressure and used different materials (semi-crystalline and amorphous polymer; the melting-fill-index (MFI) is unified to 14.5 ± 0.5 g/10 min) to explore the influences of melting pressure variation and its viscosity index on the quality characteristics of molded products. The experiment reveals that a combination of barrel, nozzle, and mold-cavity sensing on the melt-pressure trend-based injection process-control incorporated with viscosity index monitoring can confirm the weight and shrinkage variation of the injection product. At the same time, the pressure and viscosity index value measured and calculated during the melt-filling of two materials with similar MI resulted in significant variations in the amorphous polymer. This study showed the possibility of mastering and controlling the rheology (barrel position) and shrinkage properties of polymers and successful application in various product-quality monitoring platforms.


Assuntos
Polímeros , Polímeros/química , Reologia , Viscosidade
9.
Lasers Surg Med ; 53(4): 549-556, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32757279

RESUMO

BACKGROUND AND OBJECTIVES: We previously demonstrated that intense pulsed light (IPL) irradiation prior to wounding improved the wound healing in rats with diabetes mellitus (DM). Also, we found that IPL upregulated the expression of aquaporin 3 (AQP3), a protein that is crucial for wound healing, in normal rats. This present study aimed to examine the involvement of AQPs in the IPL-enhanced wound healing in diabetic rats. STUDY DESIGN/MATERIALS AND METHODS: Streptozotocin was used to induce diabetes in Sprague-Dawley rats. Animals were divided into four groups: normal group, DM only group, DM rats with IPL treatment 2 weeks before wounding (DM + IPL-Pre group), and DM rats with concurrent IPL irradiation and wounding (DM + IPL-Con group). Wounds were created on the dorsal skin of rats. The expressions of AQP1, 3, 4, 7, and 9 in the pre-injured skin, periwound, and wound were determined. RESULTS: Among all the AQPs analyzed, only the expressions of AQP3 and AQP7 were significantly altered. Unirradiated diabetic rats showed much higher expression level of AQP3 in the regenerating skin compared with normal rats. IPL pretreatment, but not concurrent treatment, attenuated the expression toward the level detected in the normal wounds. In contrast, a lower expression level of AQP7 was noted in the regenerating skin of DM only rats and IPL pretreatment upregulated the expression to a level similar to that in the normal rats. CONCLUSION: The beneficial effect of IPL pretreatment on the wound healing in diabetic rats might involve a mechanism by which the expression of AQPs is regulated. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.


Assuntos
Aquaporinas , Diabetes Mellitus Experimental , Fototerapia , Cicatrização , Animais , Aquaporinas/metabolismo , Ratos , Ratos Sprague-Dawley , Pele
10.
Nano Lett ; 20(6): 4700-4707, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32453958

RESUMO

Metallic zinc as a rechargeable anode material for aqueous batteries has gained tremendous attention. Zn-air batteries, which operate in alkaline electrolytes, are promising with the highest theoretical volumetric energy density. However, rechargeable zinc anodes develop slowly in alkaline electrolytes due to passivation, dissolution, and hydrogen evolution issues. In this study, we report the design of a submicron zinc anode sealed with an ion-sieving coating that suppresses hydrogen evolution reaction. The design is demonstrated with ZnO nanorods coated by TiO2, which overcomes passivation, dissolution, and hydrogen evolution issues simultaneously. It achieves superior reversible deep cycling performance with a high discharge capacity of 616 mAh/g and Coulombic efficiency of 93.5% when cycled with 100% depth of discharge at lean electrolyte. It can also deeply cycle ∼350 times in a beaker cell. The design principle of this work may potentially be applied to other battery electrode materials.

11.
Int J Mol Sci ; 22(8)2021 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-33920454

RESUMO

Liver cancer remains a leading cause of death, despite advances in anti-cancer therapies. To develop novel drugs, natural products are being considered as a good source for exploration. In this study, a natural product isolated from a soft coral was applied to evaluate its anti-cancer activities in hepatocellular carcinoma SK-HEP-1 cells. Sinularin was determined to have half-maximal inhibitory concentration (IC50) values of ~10 µM after 24, 48, and 72 h. The TUNEL assay and annexin V/PI staining results showed that sinularin induced DNA fragmentation and apoptosis, respectively. An investigation at the molecular level demonstrated that the expression levels of cleaved caspases 3/9 were significantly elevated at 10 µM sinularin. Mitochondrial and intracellular reactive oxygen species (ROS) levels were significantly increased following sinularin treatment, which also affected the mitochondrial membrane potential. In addition, it significantly lowered the mitochondrial respiration parameters and extracellular acidification rates at 10 µM. Further investigation showed that sinularin significantly attenuated wound healing, cell migration, and potential colony formation at 10 µM. Fluorescence microscopic observations showed that the distribution of F-actin filaments was significantly altered at 10 µM sinularin. Supported by Western blot analyses, the expression levels of AKT, p-ERK (extracellular-signal-related kinase), vimentin and VEGF were significantly down-regulated, whereas p-p38, pJNK and E-cadherin were significantly increased. Overall, at the IC50 concentration, sinularin was able to significantly affect SK-HEP-1 cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular , Citoesqueleto/metabolismo , Diterpenos/farmacologia , Compostos Heterocíclicos com 3 Anéis/farmacologia , Neoplasias Hepáticas , Mitocôndrias Hepáticas/metabolismo , Animais , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Citoesqueleto/patologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mitocôndrias Hepáticas/patologia , Ratos
12.
J Clin Microbiol ; 58(8)2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32518072

RESUMO

Real-time reverse transcription-PCR (RT-PCR) is currently the most sensitive method to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19). However, the correlation between detectable viral RNA and culturable virus in clinical specimens remains unclear. Here, we performed virus culture for 60 specimens that were confirmed to be positive for SARS-CoV-2 RNA by real-time RT-PCR. The virus could be successfully isolated from 12 throat and nine nasopharyngeal swabs and two sputum specimens. The lowest copy number required for virus isolation was determined to be 5.4, 6.0, and 5.7 log10 genome copies/ml sample for detecting the nsp12, E, and N genes, respectively. We further examined the correlation of genome copy number and virus isolation in different regions of the viral genome, demonstrating that culturable specimens are characterized by high copy numbers with a linear correlation observed between copy numbers of amplicons targeting structural and nonstructural regions. Overall, these results indicate that in addition to the copy number, the integrity of the viral genome should be considered when evaluating the infectivity of clinical SARS-CoV-2 specimens.


Assuntos
Betacoronavirus/crescimento & desenvolvimento , Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Cultura de Vírus/métodos , Betacoronavirus/genética , COVID-19 , Teste para COVID-19 , Vacinas contra COVID-19 , Correlação de Dados , Humanos , Nasofaringe/virologia , Pandemias , Faringe/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , SARS-CoV-2
13.
Int J Mol Sci ; 21(11)2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-32486166

RESUMO

Previous studies have shown that MCL1 stabilization confers cancer cells resistance to microtubule targeting agents (MTAs) and functionally extends the lifespan of MTA-triggered mitotically arrested cells. Albendazole (ABZ), a benzimidazole anthelmintic, shows microtubule-destabilizing activity and has been repositioned for cancer therapies. To clarify the role of MCL1 in ABZ-induced apoptosis, we investigated the cytotoxicity of ABZ on human leukemia K562 cells. Treatment with ABZ for 24 h did not appreciably induce apoptosis or mitochondrial depolarization in K562 cells, though it caused the mitotic arrest of K562 cells. ABZ-evoked p38 MAPK activation concurrently suppressed Sp1-mediated MCL1 expression and increased SIRT3 mRNA stability and protein expression. ABZ and A-1210477 (an MCL1 inhibitor) enhanced the cytotoxicity of ABT-263 (a BCL2/BCL2L1 inhibitor) to their effect on MCL1 suppression. Unlike ABZ, A-1210477 did not affect SIRT3 expression and reduced the survival of K562 cells. Overexpression of SIRT3 attenuated the A-1210477 cytotoxicity on K562 cells. ABZ treatment elicited marked apoptosis and ΔΨm loss in ABT-263-resistant K562 (K562/R) cells, but did not alter SIRT3 expression. Ectopic expression of SIRT3 alleviated the cytotoxicity of ABZ on K562/R cells. Collectively, our data demonstrate that ABZ-induced SIRT3 upregulation delays the apoptosis-inducing effect of MCL1 suppression on apoptosis induction in K562 cells.


Assuntos
Albendazol/farmacologia , Antineoplásicos/farmacologia , Leucemia/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/antagonistas & inibidores , Sirtuína 3/metabolismo , Compostos de Anilina/farmacologia , Apoptose , Ciclo Celular , Humanos , Indóis/farmacologia , Células K562 , Leucemia/tratamento farmacológico , Potencial da Membrana Mitocondrial , Sulfonamidas/farmacologia , Moduladores de Tubulina/farmacologia , Regulação para Cima , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
15.
Angew Chem Int Ed Engl ; 58(43): 15228-15234, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31412156

RESUMO

Zinc-bromine flow batteries are promising for stationary energy storage, and bromine-complexing agents have been used to form phase-separated liquid polybromide products. However, an understanding of the dynamics of polybromide nucleation is limited due to the beam sensitivity and complexity of polybromides. Here we report an in operando platform composed of dark-field light microscopy and a transparent electrochemical cell to reveal the dynamics of polybromide formation in their native environment. Using our platform, we confirm and reveal the liquid nature, chemical composition, pinning effect (strong interaction with Pt), residual effect (residual charge products on the surface), self-discharging, and over-oxidation of the polybromide products. The results provide insights into the role of complexing agents and guide the future design of zinc-bromine flow batteries. Furthermore, our in operando platform can potentially be used to study sensitive species and phases in other electrochemical reactions.

17.
J Immunol ; 195(7): 3190-7, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26297758

RESUMO

The discovery of new vaccines against infectious diseases and cancer requires the development of novel adjuvants with well-defined activities. The TLR4 agonist adjuvant GLA-SE elicits robust Th1 responses to a variety of vaccine Ags and is in clinical development for both infectious diseases and cancer. We demonstrate that immunization with a recombinant protein Ag and GLA-SE also induces granzyme A expression in CD4 T cells and produces cytolytic cells that can be detected in vivo. Surprisingly, these in vivo CTLs were CD4 T cells, not CD8 T cells, and this cytolytic activity was not dependent on granzyme A/B or perforin. Unlike previously reported CD4 CTLs, the transcription factors Tbet and Eomes were not necessary for their development. CTL activity was also independent of the Fas ligand-Fas, TRAIL-DR5, and canonical death pathways, indicating a novel mechanism of CTL activity. Rather, the in vivo CD4 CTL activity induced by vaccination required T cell expression of CD154 (CD40L) and target cell expression of CD40. Thus, vaccination with a TLR4 agonist adjuvant induces CD4 CTLs, which kill through a previously unknown CD154-dependent mechanism.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Antígenos CD40/imunologia , Ligante de CD40/imunologia , Linfócitos T Citotóxicos/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Antígenos CD40/biossíntese , Ligante de CD40/biossíntese , Citotoxinas/imunologia , Proteína Ligante Fas/imunologia , Granzimas/biossíntese , Granzimas/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/imunologia , Proteínas com Domínio T/imunologia , Ligante Indutor de Apoptose Relacionado a TNF/imunologia , Células Th1/imunologia , Vacinação
19.
J Immunol ; 193(6): 2911-8, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-25086172

RESUMO

Unlike most pathogens, many of the immunodominant epitopes from Mycobacterium tuberculosis are under purifying selection. This startling finding suggests that M. tuberculosis may gain an evolutionary advantage by focusing the human immune response against selected proteins. Although the implications of this to vaccine development are incompletely understood, it has been suggested that inducing strong Th1 responses against Ags that are only weakly recognized during natural infection may circumvent this evasion strategy and increase vaccine efficacy. To test the hypothesis that subdominant and/or weak M. tuberculosis Ags are viable vaccine candidates and to avoid complications because of differential immunodominance hierarchies in humans and experimental animals, we defined the immunodominance hierarchy of 84 recombinant M. tuberculosis proteins in experimentally infected mice. We then combined a subset of these dominant or subdominant Ags with a Th1 augmenting adjuvant, glucopyranosyl lipid adjuvant in stable emulsion, to assess their immunogenicity in M. tuberculosis-naive animals and protective efficacy as measured by a reduction in lung M. tuberculosis burden of infected animals after prophylactic vaccination. We observed little correlation between immunodominance during primary M. tuberculosis infection and vaccine efficacy, confirming the hypothesis that subdominant and weakly antigenic M. tuberculosis proteins are viable vaccine candidates. Finally, we developed two fusion proteins based on strongly protective subdominant fusion proteins. When paired with the glucopyranosyl lipid adjuvant in stable emulsion, these fusion proteins elicited robust Th1 responses and limited pulmonary M. tuberculosis for at least 6 wk postinfection with a single immunization. These findings expand the potential pool of M. tuberculosis proteins that can be considered as vaccine Ag candidates.


Assuntos
Epitopos Imunodominantes/imunologia , Mycobacterium tuberculosis/imunologia , Proteínas Recombinantes de Fusão/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose Pulmonar/imunologia , Adjuvantes Imunológicos , Animais , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Feminino , Camundongos , Células Th1/imunologia , Tuberculose Pulmonar/prevenção & controle , Vacinação
20.
J Infect Dis ; 212(3): 495-504, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25637347

RESUMO

BACKGROUND: Mycobacterium tuberculosis infects one third of the world's population and causes >8 million cases of tuberculosis annually. New vaccines are necessary to control the spread of tuberculosis. T cells, interferon γ (IFN-γ), and tumor necrosis factor (TNF) are necessary to control M. tuberculosis infection in both humans and unvaccinated experimental animal models. However, the immune responses necessary for vaccine efficacy against M. tuberculosis have not been defined. The multifunctional activity of T-helper type 1 (TH1) cells that simultaneously produce IFN-γ and TNF has been proposed as a candidate mechanism of vaccine efficacy. METHODS: We used a mouse model of T-cell transfer and aerosolized M. tuberculosis infection to assess the contributions of TNF, IFN-γ, and inducible nitric oxide synthase (iNOS) to vaccine efficacy. RESULTS: CD4(+) T cells were necessary and sufficient to transfer protection against aerosolized M. tuberculosis, but neither CD4(+) T cell-produced TNF nor host cell responsiveness to IFN-γ were necessary. Transfer of Tnf(-/-) CD4(+) T cells from vaccinated donors to Ifngr(-/-) recipients was also sufficient to confer protection. Activation of iNOS to produce reactive nitrogen species was not necessary for vaccine efficacy. CONCLUSIONS: Induction of TH1 cells that coexpress IFN-γ and TNF is not a requirement for vaccine efficacy against M. tuberculosis, despite these cytokines being essential for control of M. tuberculosis in nonvaccinated animals.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Interferon gama/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose/imunologia , Tuberculose/prevenção & controle , Fator de Necrose Tumoral alfa/imunologia , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Óxido Nítrico Sintase Tipo II/imunologia , Receptores de Interleucina-17/imunologia , Vacinas contra a Tuberculose/farmacologia
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