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1.
Small ; 20(29): e2401858, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38693069

RESUMO

The efficient evolution of gaseous hydrogen and oxygen from water is required to realize sustainable energy conversion systems. To address the sluggish kinetics of the multielectron transfer reaction, bifunctional catalyst materials for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) should be developed. Herein, a tailored combination of atomically minimized iridium catalysts and highly conductive black WO3- x nanofiber supports are developed for the bifunctional electrolyzer system. Atomic Ir catalysts, particularly those that activate the OER, minimize the utilization of precious metals. The oxygen-deficient black WO3- x NF support, which boosts the HER, offers increased electronic conductivity and favorable nucleation sites for Ir loading. The Ir-black WO3- x NFs exhibit increased double-layer capacitance, a significantly reduced onset potential, lower Tafel slope, and stable cyclability for both the OER and HER, compared to large-sized Ir catalysts loaded on white WO3 nanofibers. This study offers a strategy for developing an optimal catalyst material with suitable supports for high-performance and economical water electrolysis systems for achieving carbon-negative targets.

2.
Biochem Biophys Res Commun ; 674: 124-132, 2023 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-37419033

RESUMO

Metastasis is one of the most malignant characteristics of cancer cells, in which metabolic reprogramming is crucial for promoting and sustaining multi-steps of metastasis, including invasion, migration and infiltration. Recently, it has been shown that melanoma cells undergo a metabolic switching toward the upregulation of fatty acid oxidation (FAO) during metastasis. However, the underlying mechanisms by which FAO contributes to metastasis of melanoma cells remain obscure. Here, we report that FAO contributes to melanoma cell migration and invasion by regulating the formation of autophagosomes. Pharmacological or genetic inhibition of FAO impairs migration of melanoma cells, which seems not to be linked to energy production or redox homeostasis. Importantly, we reveal that acetyl-CoA production by FAO contributes to melanoma cell migration through autophagy regulation. Mechanistically, FAO inhibition results in increased autophagosome formation, which suppresses migration and invasion properties of melanoma cells. Our results underscore the crucial role of FAO in melanoma cell migration and support the potential therapeutic relevance of modulating cellular acetyl-CoA levels to inhibit cancer metastasis.


Assuntos
Melanoma , Humanos , Acetilcoenzima A/metabolismo , Melanoma/metabolismo , Oxirredução , Movimento Celular/fisiologia , Autofagia , Ácidos Graxos/metabolismo
3.
Small ; 19(37): e2300825, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37231553

RESUMO

Alkaline water electrolysis (AWE) is considered a promising technology for green hydrogen (H2 ) production. Conventional diaphragm-type porous membranes have a high risk of explosion owing to their high gas crossover, while nonporous anion exchange membranes lack mechanical and thermochemical stability, limiting their practical application. Herein, a thin film composite (TFC) membrane is proposed as a new category of AWE membranes. The TFC membrane consists of an ultrathin quaternary ammonium (QA) selective layer formed via Menshutkin reaction-based interfacial polymerization on a porous polyethylene (PE) support. The dense, alkaline-stable, and highly anion-conductive QA layer prevents gas crossover while promoting anion transport. The PE support reinforces the mechanical and thermochemical properties, while its highly porous and thin structure reduces mass transport resistance across the TFC membrane. Consequently, the TFC membrane exhibits unprecedentedly high AWE performance (1.16 A cm-2 at 1.8 V) using nonprecious group metal electrodes with a potassium hydroxide (25 wt%) aqueous solution at 80 °C, significantly outperforming commercial and other lab-made AWE membranes. Moreover, the TFC membrane demonstrates remarkably low gas crossover, long-term stability, and stack cell operability, thereby ensuring its commercial viability for green H2 production. This strategy provides an advanced material platform for energy and environmental applications.

4.
BMC Oral Health ; 22(1): 97, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35351072

RESUMO

BACKGROUND: This study was performed to evaluate the long-term clinical efficacy of the CA implants (Osstem Implant, Busan, Korea), calcium-modified surfaced treated implants on acid-etched surfaces sandblasted with alumina. METHODS: From January 2013 to December 2015, 258 implants of 120 patients placed between 2013 and 2015 were retrospectively studied. Using medical records and periapical radiographs, sex, age, location, fixture width and length of placed implants, presence or absence of bone graft, types of bone substitutes and membrane used for bone grafting, primary and secondary stability, initial and delayed complications, and marginal bone loss were investigated. The success rate and survival rate of the implants in each group were analyzed retrospectively based on the criteria suggested by Albrektsson et al. RESULTS: Between 2013 and 2015, with a follow-up longer than 5 years, 258 implants with an average diameter of 4.63 mm (3.5-5.5 mm) and an average length of 9.94 mm (7.0-13.0 mm) were placed in a total of 120 patients (61 males and 59 females) with a mean age of 63.7 years for an average of 62 months of observation period. The survival rate was 97.3%, the success rate was 94.2%, and the average final marginal bone loss was 0.074 mm. CONCLUSION: The CA implants manufactured with the improved surface treatment method exhibited a survival rate of 97.3% and a success rate of 94.2% over an average observation period of 62 months. The implants were not affected by most factors and had very high survival and success rates over a long period of observation. In particular, the stability of the implant was excellent, with no cases of failed implants in delayed placement after bone grafting and a healing period.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/etiologia , Implantação Dentária Endóssea/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
5.
Sensors (Basel) ; 21(20)2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34695946

RESUMO

Today, a lot of research on autonomous driving technology is being conducted, and various vehicles with autonomous driving functions, such as ACC (adaptive cruise control) are being released. The autonomous vehicle recognizes obstacles ahead by the fusion of data from various sensors, such as lidar and radar sensors, including camera sensors. As the number of vehicles equipped with such autonomous driving functions increases, securing safety and reliability is a big issue. Recently, Mobileye proposed the RSS (responsibility-sensitive safety) model, which is a white box mathematical model, to secure the safety of autonomous vehicles and clarify responsibility in the case of an accident. In this paper, a method of applying the RSS model to a variable focus function camera that can cover the recognition range of a lidar sensor and a radar sensor with a single camera sensor is considered. The variables of the RSS model suitable for the variable focus function camera were defined, the variable values were determined, and the safe distances for each velocity were derived by applying the determined variable values. In addition, as a result of considering the time required to obtain the data, and the time required to change the focal length of the camera, it was confirmed that the response time obtained using the derived safe distance was a valid result.


Assuntos
Condução de Veículo , Radar , Tempo de Reação , Reprodutibilidade dos Testes , Tecnologia
6.
Hum Factors ; 62(5): 770-786, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31265347

RESUMO

OBJECTIVE: To examine the effects of the gripping condition, device thickness, and hand length on bimanual perceived grip comfort associated with unrolling hand-held rollable screens. BACKGROUND: Rollable displays can be rolled and unrolled to change screen size. Although diverse rollable display device concepts have been suggested, little is known regarding ergonomic forms for comfortable screen unrolling. METHOD: Thirty young individuals (10 in each hand-length group) evaluated three rollable display device prototypes in three gripping conditions (no restriction on using side bezels, minimal use of side bezels, and restriction on the gripping type). Prototypes differed in their right-side thickness (2, 6, and 10 mm). Side bezel regions grasped during screen unrolling and corresponding bimanual grip comfort ratings were obtained. RESULTS: To improve perceived grip comfort and accommodate user-preferred gripping methods, rollable display devices should be 6 mm (preferably 10 mm) thick (vs. 2 mm) and have at least 20-mm-wide side bezels. Relative to device thickness, gripping conditions were more influential on grip comfort ratings. The "no restriction" condition improved grip comfort ratings and strengthened bimanual coupling in terms of grip comfort ratings. CONCLUSION: Contrary to current smartphone trends toward thinner and bezel-less designs, hand-held rollable display devices should be sufficiently thick and have sufficiently wide side bezels for screen unrolling. APPLICATION: Hand-held rollable display devices should be 6- or preferably 10-mm thick (vs. 2 mm) and have at least 20-mm-wide side bezels to ensure higher perceived grip comfort during bilateral screen unrolling.


Assuntos
Desenho de Equipamento , Ergonomia , Força da Mão/fisiologia , Feminino , Humanos , Masculino , Adulto Jovem
7.
Nano Lett ; 18(4): 2450-2458, 2018 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-29578723

RESUMO

Bimetallic PtNi nanoparticles have been considered as a promising electrocatalyst for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) owing to their high catalytic activity. However, under typical fuel cell operating conditions, Ni atoms easily dissolve into the electrolyte, resulting in degradation of the catalyst and the membrane-electrode assembly (MEA). Here, we report gallium-doped PtNi octahedral nanoparticles on a carbon support (Ga-PtNi/C). The Ga-PtNi/C shows high ORR activity, marking an 11.7-fold improvement in the mass activity (1.24 A mgPt-1) and a 17.3-fold improvement in the specific activity (2.53 mA cm-2) compared to the commercial Pt/C (0.106 A mgPt-1 and 0.146 mA cm-2). Density functional theory calculations demonstrate that addition of Ga to octahedral PtNi can cause an increase in the oxygen intermediate binding energy, leading to the enhanced catalytic activity toward ORR. In a voltage-cycling test, the Ga-PtNi/C exhibits superior stability to PtNi/C and the commercial Pt/C, maintaining the initial Ni concentration and octahedral shape of the nanoparticles. Single cell using the Ga-PtNi/C exhibits higher initial performance and durability than those using the PtNi/C and the commercial Pt/C. The majority of the Ga-PtNi nanoparticles well maintain the octahedral shape without agglomeration after the single cell durability test (30,000 cycles). This work demonstrates that the octahedral Ga-PtNi/C can be utilized as a highly active and durable ORR catalyst in practical fuel cell applications.

8.
Ergonomics ; 62(6): 723-733, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30938586

RESUMO

Limited information is available regarding ergonomic foldable display device forms. This two-stage study involving young South Koreans (divided into three hand-length groups) was conducted to determine ergonomic forms for hand-held foldable display devices considering folding/unfolding comfort and preference. Stage I obtained the suitability of three screen sizes for five tasks. Stage II evaluated 14 different bi- and tri-folding methods considering screen size, folding direction, and folding time. The effects of hand length were all non-significant. Screen size preferences were task-dependent; small screens were preferred for making calls, and medium screens for web searching and gaming. Folding methods affected folding/unfolding comfort and preference; outward screen and Z-shape screen folding were the most preferred bi- and tri-fold concepts, respectively. Screen protection and access appeared to be competing factors in the user preference determination process. Foldable screen size and folding method should be determined by considering tasks, folding/unfolding comfort, and user preferences. Practitioner summary: A 13.5 cm screen was preferred for making calls, whereas a 17.5 cm screen was best for web searching and gaming. An outward bi-fold screen concept with a 17.5 cm screen and Z-shape tri-fold screen concept with a 22.9 cm screen were preferred. Overall, the Z-shape concept was most preferred. Abbreviations: SD: standard deviation; ANOVA: analysis of variance; H: Height; W: Width; T: Thickness.


Assuntos
Computadores de Mão , Apresentação de Dados , Desenho de Equipamento/métodos , Ergonomia/métodos , Interface Usuário-Computador , Feminino , Mãos/anatomia & histologia , Humanos , Masculino , Análise e Desempenho de Tarefas , Adulto Jovem
9.
Biochem Biophys Res Commun ; 501(3): 739-744, 2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-29753744

RESUMO

Contact inhibition (CI) is an important tumor-suppressive mechanism that arrests cell cycle when cells reach high density. Indeed, CI is aberrantly absent in cancer cells and the dysregulation of this can contribute to tumorigenesis. Previously, it has been shown that reactive oxygen species (ROS) levels are repressed at high cell density, which is required for CI, but no molecular mechanism of this ROS regulation has been reported. Here, we show that PGC1α regulates cell density-dependent CI. PGC1α is markedly induced in response to high cell density and suppresses ROS production. Although cellular ROS levels are progressively decreased with increasing cell density, knockdown of PGC1α results in a defect of density-dependent ROS suppression. Importantly, PGC1α knockdown cells become less sensitive to high cell density and exhibit loss of CI. Mechanistically, PGC1α represses ROS production by inducing mitochondrial SIRT3, and thus SIRT3 overexpression rescues the defects of CI by PGC1α knockdown. These results demonstrate that mitochondrial ROS production is a crucial regulator of cell proliferation and identify a new role of PGC1α in CI.


Assuntos
Proliferação de Células , Inibição de Contato , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Contagem de Células , Linhagem Celular , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Camundongos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética
10.
Small ; 11(24): 2885-92, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-25809290

RESUMO

Three-dimensional porous Sb/Sb2 O3 anode materials are successfully fabricated using a simple electrodeposition method with a polypyrrole nanowire network. The Sb/Sb2 O3 -PPy electrode exhibits excellent cycle performance and outstanding rate capabilities; the charge capacity is sustained at 512.01 mAh g(-1) over 100 cycles, and 56.7% of the charge capacity at a current density of 66 mA g(-1) is retained at 3300 mA g(-1) . The improved electrochemical performance of the Sb/Sb2 O3 -PPy electrode is attributed not only to the use of a highly porous polypyrrole nanowire network as a substrate but also to the buffer effects of the Sb2 O3 matrix on the volume expansion of Sb. Ex situ scanning electron microscopy observation confirms that the Sb/Sb2 O3 -PPy electrode sustains a strong bond between the nanodeposits and polypyrrole nanowires even after 100 cycles, which maintains good electrical contact of Sb/Sb2 O3 with the current collector without loss of the active materials.

12.
Adv Sci (Weinh) ; 11(10): e2304702, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38145969

RESUMO

The DNA damage response is essential for preserving genome integrity and eliminating damaged cells. Although cellular metabolism plays a central role in cell fate decision between proliferation, survival, or death, the metabolic response to DNA damage remains largely obscure. Here, this work shows that DNA damage induces fatty acid oxidation (FAO), which is required for DNA damage-induced cell death. Mechanistically, FAO induction increases cellular acetyl-CoA levels and promotes N-alpha-acetylation of caspase-2, leading to cell death. Whereas chemotherapy increases FAO related genes through peroxisome proliferator-activated receptor α (PPARα), accelerated hypoxia-inducible factor-1α stabilization by tumor cells in obese mice impedes the upregulation of FAO, which contributes to its chemoresistance. Finally, this work finds that improving FAO by PPARα activation ameliorates obesity-driven chemoresistance and enhances the outcomes of chemotherapy in obese mice. These findings reveal the shift toward FAO induction is an important metabolic response to DNA damage and may provide effective therapeutic strategies for cancer patients with obesity.


Assuntos
Ácidos Graxos , PPAR alfa , Camundongos , Animais , Humanos , Oxirredução , Ácidos Graxos/metabolismo , PPAR alfa/metabolismo , Camundongos Obesos , Resistencia a Medicamentos Antineoplásicos , Obesidade/metabolismo , Morte Celular
13.
Skin Res Technol ; 19(1): e515-20, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22957992

RESUMO

BACKGROUND: Fractional photothermolysis is a popular treatment option for photorejuvenation. Previous literature studies have demonstrated the clinical effectiveness of fractional photothermolysis on cutaneous photoaging; however, the associated changes in biophysical properties of the skin following fractional photothermolysis have not been fully elucidated. This study was conducted to investigate the temporal changes in biophysical parameters after fractional laser treatment on Asian skin. MATERIALS AND METHODS: Eleven female subjects underwent a single treatment with an erbium glass fractional laser. Skin roughness, elasticity, transepidermal water loss (TEWL), dermal thickness were evaluated before and immediately after treatment and 3 days, 1 week, 2 weeks, and 4 weeks after treatment. The changes in the dermal papilla were analyzed using a reflectance confocal microscopy (RCM). RESULTS: Skin roughness showed the greatest improvement at the first week and net elasticity was most improved at the second week. TEWL and the percentage of melanized and active dermal papillae (DP) were mostly increased for 3 days. At 4 weeks after treatment, the number of total dermal papillae showed a significant increase compared with pretreatment. CONCLUSION: This is the first study of the characterization and quantification of dermal papilla reflecting the dermal repair process after fractional photothermolysis through an RCM.


Assuntos
Dermoscopia/métodos , Terapia com Luz de Baixa Intensidade/métodos , Microscopia Confocal/métodos , Rejuvenescimento , Envelhecimento da Pele/patologia , Envelhecimento da Pele/efeitos da radiação , Adulto , Povo Asiático , Fenômenos Biofísicos , Derme/patologia , Derme/efeitos da radiação , Elasticidade/fisiologia , Elasticidade/efeitos da radiação , Feminino , Humanos , Lasers de Estado Sólido/efeitos adversos , Lasers de Estado Sólido/uso terapêutico , Terapia com Luz de Baixa Intensidade/efeitos adversos , Resultado do Tratamento , Perda Insensível de Água/fisiologia , Perda Insensível de Água/efeitos da radiação , Adulto Jovem
14.
Materials (Basel) ; 16(23)2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38068169

RESUMO

Hydrogen generation through the hydrolysis of aluminum alloys has attracted significant attention because it generates hydrogen directly from alkaline water without the need for hydrogen storage technology. The hydrogen generation rate from the hydrolysis of aluminum in alkaline water is linearly proportional to its corrosion rate. To accelerate the corrosion rate of the aluminum alloy, we designed Al-Ni alloys by continuously precipitating an electrochemically noble Al3Ni phase along the grain boundaries. The Al-0.5~1 wt.% Ni alloys showed an excellent hydrogen generation rate of 16.6 mL/cm2·min, which is about 6.4 times faster than that of pure Al (2.58 mL/cm2·min). This excellent performance was achieved through the synergistic effects of galvanic and intergranular corrosion on the hydrolysis of Al. By raising the solution temperature to 50 °C, the optimal rate of hydrogen generation of Al-1 wt.% Ni in 10 wt.% NaOH solutions at 30 °C can be further increased to 54.5 mL/cm2·min.

15.
Cell Death Dis ; 14(7): 435, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37454129

RESUMO

DNA repair is a tightly coordinated stress response to DNA damage, which is critical for preserving genome integrity. Accruing evidence suggests that metabolic pathways have been correlated with cellular response to DNA damage. Here, we show that fatty acid oxidation (FAO) is a crucial regulator of DNA double-strand break repair, particularly homologous recombination repair. Mechanistically, FAO contributes to DNA repair by activating poly(ADP-ribose) polymerase 1 (PARP1), an enzyme that detects DNA breaks and promotes DNA repair pathway. Upon DNA damage, FAO facilitates PARP1 acetylation by providing acetyl-CoA, which is required for proper PARP1 activity. Indeed, cells reconstituted with PARP1 acetylation mutants display impaired DNA repair and enhanced sensitivity to DNA damage. Consequently, FAO inhibition reduces PARP1 activity, leading to increased genomic instability and decreased cell viability upon DNA damage. Finally, our data indicate that FAO serves as an important participant of cellular response to DNA damage, supporting DNA repair and genome stability.


Assuntos
Reparo do DNA , DNA , Humanos , Acetilação , DNA/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Quebras de DNA de Cadeia Dupla , Dano ao DNA , Ácidos Graxos
16.
Oncogene ; 42(38): 2828-2840, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37591953

RESUMO

Proliferating cells have metabolic dependence on glutamine to fuel anabolic pathways and to refill the mitochondrial carbon pool. The Hippo pathway is essential for coordinating cell survival and growth with nutrient availability, but no molecular connection to glutamine deprivation has been reported. Here, we identify a non-canonical role of YAP, a key effector of the Hippo pathway, in cellular adaptation to perturbation of glutamine metabolism. Whereas YAP is inhibited by nutrient scarcity, enabling cells to restrain proliferation and to maintain energy homeostasis, glutamine shortage induces a rapid YAP dephosphorylation and activation. Upon glutaminolysis inhibition, an increased reactive oxygen species production inhibits LATS kinase via RhoA, leading to YAP dephosphorylation. Activated YAP promotes transcriptional induction of ATF4 to induce the expression of genes involved in amino acid homeostasis, including Sestrin2. We found that YAP-mediated Sestrin2 induction is crucial for cell viability during glutamine deprivation by suppressing mTORC1. Thus, a critical relationship between YAP, ATF4, and mTORC1 is uncovered by our findings. Finally, our data indicate that targeting the Hippo-YAP pathway in combination with glutaminolysis inhibition may provide potential therapeutic approaches to treat tumors.


Assuntos
Fator 4 Ativador da Transcrição , Glutamina , Humanos , Fator 4 Ativador da Transcrição/metabolismo , Sobrevivência Celular , Homeostase , Alvo Mecanístico do Complexo 1 de Rapamicina , Mitocôndrias
17.
Cancer Gene Ther ; 30(6): 878-889, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36807391

RESUMO

Hypoxia, one of the key features of solid tumors, induces autophagy, which acts as an important adaptive mechanism for tumor progression under hypoxic environment. Cellular metabolic reprogramming has been correlated with hypoxia, but the molecular connection to the induction of autophagy remains obscure. Here, we show that suppression of fatty acid oxidation (FAO) by hypoxia induces autophagy in human pancreatic ductal adenocarcinoma (PDAC) cells that is required for their growth and survival. Reduced cellular acetyl-CoA levels caused by FAO inhibition decreases LC3 acetylation, resulting in autophagosome formation. Importantly, PDAC cells are significantly dependent on this metabolic reprogramming, as improving FAO leads to a reduction in hypoxia-induced autophagy and an increase in cell death after chemotherapy. Thus, our study supports that suppression of FAO is an important metabolic response to hypoxia and indicates that targeting this pathway in PDAC may be an effective therapeutic approach.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/terapia , Hipóxia , Autofagia , Ácidos Graxos/farmacologia , Ácidos Graxos/uso terapêutico , Neoplasias Pancreáticas
18.
Chemosphere ; 344: 140314, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37769914

RESUMO

This work demonstrates a simple and scalable methodology for the binder-free direct growth of Mo-doped NiFe-layered double hydroxides on a nickel substrate via an electrodeposition route at room temperature. A three-dimensional (3D) nanosheet array morphology of the electrocatalyst provides immense electrochemical surface area as well as abundant catalytically active sites. Mo incorporation in the NiFe-LDH plays a crucial role in regulating the catalytic activity of oxygen evolution reaction (OER). The prepared electrocatalyst exhibited low overpotential (i.e., 230 mV) at 30 mA cm-2 for OER in an alkaline electrolyte (i.e., 1 M KOH). Furthermore, the optimized Mo-doped NiFe-LDH electrode was used as an anode in a laboratory-scale in situ single cell test system for alkaline water electrolysis at 80 °C with a continuous flow of 30 wt% KOH, and it shows the efficient electrochemical performance with a lower cell voltage of 1.80 V at a current density of 400 mA cm-2. In addition, an admirable long-term cell durability is also demonstrated by the cell for 24 h. This work encourages new designs and further development of electrode material for alkaline water electrolysis on a commercial scale.


Assuntos
Eletrólise , Água , Galvanoplastia , Eletrodos , Oxigênio
19.
J Korean Assoc Oral Maxillofac Surg ; 48(4): 225-231, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36043253

RESUMO

Objectives: This study aims to evaluate the efficacy and safety of two types of sandblasted with large-grit and acid-etched (SLA) surface implants with different surface roughness. Patients and. Methods: This study was conducted based on a clinical record review of 55 patients (mean age, 53.00 years). A total of 80 SLA surface implants was placed. Among the 80 implants, 38 implants placed in 29 subjects had surface roughness (Ra) of 3.09 µm (test group, TG), while the other 42 implants placed in 31 subjects had a surface roughness (Ra) of 2.50 µm (control group, CG). A comparison was made of implant primary/ secondary stability; success and survival rates; marginal bone loss; and soft tissue assessment including probing pocket depth (PPD), plaque index (PI), gingival index (GI), and bleeding on probing (BOP) between the groups at 1 year after implant placement. Results: Among the implants that were initially registered, 1 from the TG and 4 from the CG dropped out, leaving 37 implants in the TG and 38 implants in the CG to be traced and analyzed. Although 1 TG case showed unstable primary stability, all cases showed stable secondary stability. Success and survival rates at 1 year after implant placement were 100% in both groups. Marginal bone loss was 0.07 mm and 0.00 mm for the TG and CG, respectively, but the difference was not significant. Among the several parameters for evaluation of soft tissue, the TG showed lower PI at 1 year after implant placement (TG=0.00, CG=0.29; P=0.0004), while the remaining categories showed no significant difference between the groups. Conclusion: This study shows that the two types of SLA implants with different surface roughness have no difference in efficacy or safety. Therefore, both of the implants can be used safely and with promising outcomes.

20.
Cell Death Discov ; 7(1): 395, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34924566

RESUMO

The DNA damage response is essential for sustaining genomic stability and preventing tumorigenesis. However, the fundamental question about the cellular metabolic response to DNA damage remains largely unknown, impeding the development of metabolic interventions that might prevent or treat cancer. Recently, it has been reported that there is a link between cell metabolism and DNA damage response, by repression of glutamine (Gln) entry into mitochondria to support cell cycle arrest and DNA repair. Here, we show that mitochondrial Gln metabolism is a crucial regulator of DNA damage-induced cell death. Mechanistically, inhibition of glutaminase (GLS), the first enzyme for Gln anaplerosis, sensitizes cancer cells to DNA damage by inducing amphiregulin (AREG) that promotes apoptotic cell death. GLS inhibition increases reactive oxygen species production, leading to transcriptional activation of AREG through Max-like protein X (MLX) transcription factor. Moreover, suppression of mitochondrial Gln metabolism results in markedly increased cell death after chemotherapy in vitro and in vivo. The essentiality of this molecular pathway in DNA damage-induced cell death may provide novel metabolic interventions for cancer therapy.

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