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1.
Noncoding RNA Res ; 9(3): 876-886, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38586313

RESUMO

Although rare, there is ongoing research into biomarkers that predict the onset and recurrence of gastric cancer, particularly focusing on substances found in exosomes. Long non-coding RNAs (lncRNAs) have garnered attention for their potential in diagnosing gastric cancer. This study investigates the role of lncRNAs in gastric cancer, focusing on their presence in exosomes as potential biomarkers for the disease's onset and recurrence. We utilized the ArrayStar Human LncRNA array 2.0 to analyze lncRNA expression in tissues from early-stage gastric cancer patients. Our analysis highlighted LINC00853, which was significantly upregulated in cancer tissues and implicated in promoting epithelial-mesenchymal transition via the MAP17/PDZK1/AKT pathway. Functional studies on AGS and MKN74 gastric cancer cell lines demonstrated that LINC00853 facilitates cell proliferation, invasion, and migration. Additionally, RNA immunoprecipitation and electrophoretic mobility shift assays confirmed LINC00853 interaction with MAP17. Importantly, LINC00853 was also detected in exosomes from both patient samples and cell lines, and its downregulation led to decreased tumorigenicity in AGS cells. These findings suggest that both cellular and exosomal LINC00853 contribute to gastric cancer pathogenesis and may serve as valuable biomarkers for the disease.

2.
Ann Dermatol ; 35(Suppl 2): S195-S200, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38061702

RESUMO

Dystrophic epidermolysis bullosa (DEB) pruriginosa is a rare subtype of DEB characterized by multiple, violaceous, and severe pruritic lichenified nodules along with blisters. Here, we report the case of a Korean male who, since the age of 3 years, had multiple pruritic nodules with blisters on both lower extremities. Genetic testing is required to diagnose DEB pruriginosa because its clinical and histologic features are inconclusive. We identified compound heterozygous COL7A1 variants of c.5797C>T (p.R1933*) and c.3301C>T (p.R1101W) in the patient, leading to a diagnosis of recessive DEB pruriginosa. Among the variants identified, c.3301C>T is a novel missense variant that has not been reported previously. This variant is in exon 26, which encodes von Willebrand factor A (vWFA) in collagen type VII. vWFA is known to preserve normal dermal structures by interacting with dermal collagens and basement membranes. Considering that this variant contradicts the general concept that autosomal dominant inheritance is more common and that variants typically occur in the triple helical collagenous domain of COL7A1 in DEB pruriginosa, we focus on the rarity of this case and the possible pathogenic role of the c.3301C>T (p.R1101W) variant.

3.
Nano Converg ; 10(1): 55, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38038784

RESUMO

HfO2 shows promise for emerging ferroelectric and resistive switching (RS) memory devices owing to its excellent electrical properties and compatibility with complementary metal oxide semiconductor technology based on mature fabrication processes such as atomic layer deposition. Oxygen vacancy (Vo), which is the most frequently observed intrinsic defect in HfO2-based films, determines the physical/electrical properties and device performance. Vo influences the polymorphism and the resulting ferroelectric properties of HfO2. Moreover, the switching speed and endurance of ferroelectric memories are strongly correlated to the Vo concentration and redistribution. They also strongly influence the device-to-device and cycle-to-cycle variability of integrated circuits based on ferroelectric memories. The concentration, migration, and agglomeration of Vo form the main mechanism behind the RS behavior observed in HfO2, suggesting that the device performance and reliability in terms of the operating voltage, switching speed, on/off ratio, analog conductance modulation, endurance, and retention are sensitive to Vo. Therefore, the mechanism of Vo formation and its effects on the chemical, physical, and electrical properties in ferroelectric and RS HfO2 should be understood. This study comprehensively reviews the literature on Vo in HfO2 from the formation and influencing mechanism to material properties and device performance. This review contributes to the synergetic advances of current knowledge and technology in emerging HfO2-based semiconductor devices.

4.
Ann Dermatol ; 35(Suppl 1): S103-S106, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37853878

RESUMO

Bullous pemphigoid (BP) is a chronic, autoimmune blistering disease that has concerning morbidity and mortality rates. Recently, several studies have focused on eosinophils due to their significant role in the pathogenesis of BP, considering that they are ubiquitous in the serum, tissue, and blister fluids of patients with BP. With this context, precision therapy that targets mediators of eosinophil activity could be a possible novel therapeutic strategy. Interleukin (IL)-5 is crucial for B-cell maturation, which consequently results in immunoglobulin production, and promotes eosinophil differentiation, proliferation, and activation. To our best knowledge, reslizumab has not yet been reported to treat BP. Herein, we report a case of steroid- and omalizumab-resistant BP treated successfully using reslizumab. Our data suggest that IL-5 could be a novel specific biologic target within the entire immunopathogenesis of BP, and reslizumab would be a novel therapeutic modality.

5.
Nano Lett ; 23(14): 6360-6368, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37409775

RESUMO

Vertical two-terminal synaptic devices based on resistive switching have shown great potential for emulating biological signal processing and implementing artificial intelligence learning circuitries. To mimic heterosynaptic behaviors in vertical two-terminal synaptic devices, an additional terminal is required for neuromodulator activity. However, adding an extra terminal, such as a gate of the field-effect transistor, may lead to low scalability. In this study, a vertical two-terminal Pt/bilayer Sr1.8Ag0.2Nb3O10 (SANO) nanosheet/Nb:SrTiO3 (Nb:STO) device emulates heterosynaptic plasticity by controlling the number of trap sites in the SANO nanosheet via modulation of the tunneling current. Similar to biological neuromodulation, we modulated the synaptic plasticity, pulsed pair facilitation, and cutoff frequency of a simple two-terminal device. Therefore, our synaptic device can add high-level learning such as associative learning to a neuromorphic system with a simple cross-bar array structure.

6.
Adv Mater ; 35(35): e2302219, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37116944

RESUMO

Technologies based on the fusion of gas sensors and neuromorphic computing to mimic the olfactory system have immense potential. However, the implementation of neuromorphic olfactory systems remains in a state of infancy because conventional gas sensors lack the necessary functions. Therefore, this study proposes a hysteretic "chemi-memristive gas sensor" based on oxygen vacancy chemi-memristive dynamics that differ from that of conventional gas sensors. After the memristive switching operation, the redox reaction with the external gas molecules is enhanced, resulting in the generation and elimination of oxygen vacancies that induce rapid current changes. In addition, the pre-generated oxygen vacancies enhance the post-sensing properties. Therefore, fast responses, short recovery times, and hysteretic gas response are achieved by the proposed sensor at room temperature. Based on the advantageous functionality of the sensor, device-level olfactory systems that can monitor the history of input gas stimuli are experimentally demonstrated as a potential application. Moreover, analog conductance modulation induced by oxidizing and reducing gases enables the conversion of external gas stimuli into synaptic weights and hence the realization of typical synaptic functionalities without an additional device or circuit. The proposed chemi-memristive device represents an advance in the bioinspired technology adopted in creating artificial intelligence systems.

7.
ACS Appl Mater Interfaces ; 15(4): 5495-5503, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36691225

RESUMO

Active cation-based diffusive memristors featuring essentially volatile threshold switching have been proposed for novel applications, such as a selector in a one-selector-and-one-resistor structure and signal generators in neuromorphic computing. However, the high variability of the switching behavior, which results from the high electroforming voltage, external environmental conditions, and transition to the non-volatile switching mode in a high-current range, is considered a major impediment to such applications. Herein, for the first time, we developed a highly reliable threshold switching device immune to atmospheric changes based on an ultraviolet-ozone (UVO)-treated diffusive memristor consisting of Ag and SiO2 nanorods (NRs). UVO treatment forms a stable water reservoir on the surface of SiO2 NRs, facilitating the redox reaction and ion migration of Ag. Consequently, diffusive memristors possess reliable switching characteristics, including electroforming-free, repeatable, and consistent switching with resistance to changes in ambient conditions and compliance levels during operation. We demonstrated that our approach is suitable for various metal oxides and can be used in numerous applications.

8.
Australas J Dermatol ; 64(1): 50-57, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36695042

RESUMO

BACKGROUND/OBJECTIVES: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a potentially life-threatening hypersensitive disorder. Cyclosporine has been indicated for adverse cutaneous drug eruptions. However, studies evaluating its clinical effectiveness in DRESS syndrome have been rare. This study aimed to evaluate the clinical efficacy of cyclosporine in DRESS syndrome compared to that of systemic corticosteroids. METHODS: In the cyclosporine group, oral cyclosporine was administered twice a day for a total of 2-3 mg/kg/day for 1 week, and subsequently reduced to 1-1.5 mg/kg/day for extended treatment. In the corticosteroid group, intravenous or oral methylprednisolone was administered at 1-1.5 mg/kg/day for 1 week, with variable tapering plans. Laboratory changes before and after treatment, hospitalized days, treatment periods, and time to normalization from clinical manifestations in each group were statistically evaluated. Adverse effects of these regimens were observed during the entire treatment period. RESULTS: Eighty patients were enrolled in this retrospective study. The cyclosporine and corticosteroid group had 27 and 53 patients, respectively. Total leucocyte and eosinophil counts, liver enzymes, and C-reactive proteins were significantly decreased after treatment in both groups. There were no statistically significant differences observed in hospitalized days, treatment period, and time to normalization from clinical manifestations between the two groups. The corticosteroid group experienced relatively more adverse effects than the cyclosporine group. CONCLUSIONS: Cyclosporine was discovered to be clinically effective in DRESS syndrome and this study suggests that cyclosporine could be a feasible primary therapeutic option for DRESS syndrome.


Assuntos
Síndrome de Hipersensibilidade a Medicamentos , Eosinofilia , Exantema , Humanos , Síndrome de Hipersensibilidade a Medicamentos/tratamento farmacológico , Síndrome de Hipersensibilidade a Medicamentos/etiologia , Ciclosporina/efeitos adversos , Estudos Retrospectivos , Eosinofilia/induzido quimicamente , Eosinofilia/tratamento farmacológico , Exantema/tratamento farmacológico , Corticosteroides/efeitos adversos
9.
Photodermatol Photoimmunol Photomed ; 39(2): 147-154, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36461152

RESUMO

BACKGROUND/PURPOSE: The pathogenesis of chronic actinic dermatitis (CAD) is more complicated than other photodermatoses. However, the relationship between the clinical severity of CAD and the offending photocontact or contact allergens or both, and the correlations of CAD immunopathogenesis with the immunoregulatory molecules involved in adaptive immunity are yet to be investigated. METHODS: We performed phototesting with broad-spectrum ultraviolet (UV) B, UVA, and visible light to establish the presence of photosensitivity in 121 patients with CAD, together with photopatch and contact patch testing. Nine patients with CAD were selected according to their clinical severity score for CAD (CSS-CAD), and triple direct immunofluorescence analysis was performed with paraffin-embedded skin biopsy samples. RESULTS: As CSS-CAD was closely correlated with the multiplicity of photo(contact) allergens, particularly photoallergens, three or more photoallergens were detected in the severe CAD group (52.5%); less in the moderate group (32.8%); and only one in the mild group (14.8%; P = .025). In the groups showing greater severity of disease, the absolute numbers of IFN-γ+ , IL-17+ , CD4+, CD8+, common-γ chain receptor (common-γCR)+ , and CD69+ tissue-resident memory cells increased on average; there was also an increase in the CD4+/CD8+ cell ratio, with the more severely affected groups. However, the levels of TNF-α+ and FoxP3+ regulatory T (Treg) cells and the mean IL-17/IFN-γ cell ratio decreased in the more severely affected CSS-CAD subgroups. CONCLUSIONS: Based on the clinical analysis and immunopathogenic results, avoidance of excessive sun exposure, and topical and systemic blocking agents for photo(contact) allergens are recommended. Additionally, conventional immunomodulators and emerging agents including JAK-STAT inhibitors may be administered for CAD treatment in the future.


Assuntos
Transtornos de Fotossensibilidade , Linfócitos T Reguladores , Células Th17 , Humanos , Imunidade Adaptativa , Alérgenos/uso terapêutico , Interleucina-17 , Transtornos de Fotossensibilidade/patologia , Linfócitos T Citotóxicos/patologia , Linfócitos T Reguladores/patologia , Receptores de Antígenos de Linfócitos T gama-delta
10.
ACS Appl Mater Interfaces ; 14(39): 44550-44560, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36149315

RESUMO

The switching characteristics and performance of oxide-based memristors are predominately determined by oxygen- or oxygen-vacancy-mediated redox reactions and the consequent formation of conducting filaments (CFs). Devices using oxide thin films as the switching layer usually require an electroforming process for subsequent switching operations, which induces large device-to-device variations. In addition, the hard-to-control redox reaction during repeated switching causes random fluctuations or degradation of each resistance state, hindering reliable switching operations. In this study, an HfO2 nanorod (NR)-based memristor is proposed for simultaneously achieving highly uniform, electroforming-free, fast, and reliable analogue switching properties. The well-controlled redox reaction due to the easy gas exchange with the environment at the surface of the NRs enhances the generation of oxygen or oxygen vacancies during the switching operation, resulting in electroforming-free and reliable switching behavior. In addition, the one-dimensional surface growth of CFs facilitates highly linear conductance modulation with smaller conductance changes compared with the two-dimensional volume growth in thin-film-based memristors, resulting in a high accuracy of >92% in the Modified National Institute of Standards and Technology pattern-recognition test and desirable spike-timing-dependent plasticity.

13.
Cancers (Basel) ; 14(10)2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35625973

RESUMO

DKK1 inhibits the canonical Wnt signaling pathway that is known to be involved in various cancers. However, whether DKK1 acts as an oncogene or tumor suppressor gene remains controversial. Furthermore, the DKK1-regulating mechanism in gastric cancer has not yet been defined. The aim of this study was to explore whether the ultraconserved region UC.145 regulates epigenetic changes in DKK1 expression in gastric cancer. Microarray analysis revealed that UC.145 exhibited the highest binding affinity to EZH2, a histone methyltransferase. The effects of UC.145 inactivation were assessed in gastric cancer cell lines using siRNA. The results indicated that UC.145 triggers DKK1 methylation via interaction with EZH2 and is involved in the canonical Wnt signaling pathway. Additionally, interaction between UC.145 and another long non-coding RNA adjacent to DKK1, PRKG1-AS1, induced a synergistic effect on Wnt signaling. The regulation of these three genes was closely associated with patient overall survival. Inactivation of UC.145 induced apoptosis and inhibited the growth and migratory, invasive, and colony-forming abilities of gastric cancer cells. The study findings provide insights into Wnt signaling in gastric cancer and support UC.145 as a potential novel predictive biomarker for the disease.

14.
Adv Sci (Weinh) ; 9(4): e2103484, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34837480

RESUMO

A biological receptor serves as sensory transduction from an external stimulus to an electrical signal. It allows humans to better match the environment by filtering out repetitive innocuous information and recognize potentially damaging stimuli through key features, including adaptive and maladaptive behaviors. Herein, for the first time, the authors develop substantial artificial receptors involving both adaptive and maladaptive behaviors using diffusive memristor. Metal-oxide nanorods (NR) as a switching matrix enable the electromigration of an active metal along the surface of the NRs under electrical stimulation, resulting in unique surface-dominated switching dynamics with the advantage of fast Ag migration and fine controllability of the conductive filament. To experimentally demonstrate its potential application, a thermoreceptor system is constructed using memristive artificial receptors. The proposed surface-dominated diffusive memristor allows the direct emulation of the biological receptors, which represents an advance in the bioinspired technology adopted in creating artificial intelligence systems.


Assuntos
Condutividade Elétrica , Nanotecnologia/métodos , Redes Neurais de Computação , Receptores Artificiais , Células Receptoras Sensoriais/fisiologia , Estimulação Elétrica , Desenho de Equipamento , Metais , Óxidos
16.
Yonsei Med J ; 62(2): 118-128, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33527791

RESUMO

PURPOSE: HOX transcript antisense intergenic RNA (HOTAIR), as a long non-coding RNA, has been reported to regulate carcinogenesis by epigenetic mechanism in various cancers. Protocadherin 10 (PCDH10) is one of the well-known tumor suppressor genes, and is frequently methylated in gastric cancers (GC). We aimed to investigate the detailed pathway of how HOTAIR contributes to the target gene in gastric carcinogenesis. MATERIALS AND METHODS: We investigated the mechanism of HOTAIR on carcinogenesis and metastasis of GC. Methylation-specific PCR was performed to identify the interaction between HOTAIR and PCDH10. In addition, we investigated the interaction between miR-148b and HOTAIR by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. RESULTS: The expression of HOTAIR was significantly upregulated in GC tissues (p<0.05) and GC cell lines (p<0.01), while PCDH10 was downregulated in GC tissues (p<0.05). The knockdown of HOTAIR (si-HOTAIR1 and 2) significantly upregulated the mRNA/protein expression of PCDH10 and reduced the methylation of PCDH10 compared to the control in MKN 28 and MKN 74. Si-HOTAIR1 and 2 significantly reduced DNA methyltransferase 1 (DNMT1) expression, and overexpression of HOTAIR increased DNMT1 expression. In RIP, we found that miR-148b interacted with HOTAIR. Si-HOTAIRs increased miR-148b expression, and miR-148b mimic inversely reduced HOTAIR expression. Si-HOTAIRs and miR-148b mimic reduced DNMT1 expression and increased PCDH10 expression compared to the control. CONCLUSION: This study demonstrated that HOTAIR interacts with miR-148b and DNMT1, eventually leading to PCDH10 methylation, which contributes to the progression of GC. Our findings provide a better understanding for detailed pathway of HOTAIR in epigenetic mechanism of GC.


Assuntos
Adenocarcinoma/genética , Caderinas/genética , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Metilação de DNA/genética , Genes Supressores de Tumor , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , Neoplasias Gástricas/genética , Apoptose/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica , Protocaderinas , Neoplasias Gástricas/patologia
17.
Yonsei Med J ; 61(11): 923-934, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33107235

RESUMO

PURPOSE: The mechanisms of Wnt/ß-catenin pathway signaling and abnormal expression of tumor suppressor genes is not well known in gastric cancer (GC). Long non-coding RNA (lncRNA) has recently been identified as a possible link therein. In this study, we investigated the role of lung cancer associated transcript 1 (LUCAT1) in GC. MATERIALS AND METHODS: The expression of LUCAT1 in GC cell lines and 100 tissue samples was examined by qRT-PCR. Two different siRNAs were used for knockdown of LUCAT1 expression. Cell viability was assessed by MTT assay. To analyze metastasis, scratch wound-healing assay, a Matrigel invasion assay, and colony formation assay were performed. Apoptosis was analyzed by PI/Annexin-V staining. To check the methylation status in tumor suppressor genes, methylation-specific PCR was carried out. Western blot was performed to detect epithelial-mesenchymal transition and apoptosis markers upon silencing of LUCAT1 (siLUCAT1). RESULTS: LUCAT1 expression in GC cell lines and tissues was significantly elevated, compared to that in normal gastric cells and adjacent non-tumor tissues (p<0.001). Two different siRNAs for LUCAT1 reduced cell proliferation, invasion, and migration, compared to siCT (p<0.05), and these reductions were restored by pcDNA-LUCAT1 (p<0.05). siLUCAT1 elicited upregulation of the expression of CXXC4 and SFRP2. The expression of H3K27me3 was reduced by siLUCAT1, and this reduction was correlated with methylation of CXXC4 and SFRP2. Inhibition of LUCAT1 up-regulated EZH2 expression and resulted in demethylation of CXXC4 and SFRP2 through the Wnt/ß-catenin signaling pathway. CONCLUSION: We concluded that LUCAT1 induces methylation of CXXC4 and SFRP2, thereby regulating Wnt/ß-catenin signaling in GC.


Assuntos
Proteínas de Ligação a DNA/genética , Genes Supressores de Tumor , Proteínas de Membrana/genética , Invasividade Neoplásica/genética , RNA Longo não Codificante/metabolismo , Neoplasias Gástricas/genética , Fatores de Transcrição/genética , Apoptose/genética , Biomarcadores Tumorais/genética , Proliferação de Células/genética , Sobrevivência Celular , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo , Transição Epitelial-Mesenquimal , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Pulmonares/genética , Proteínas de Membrana/metabolismo , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/patologia , Fatores de Transcrição/metabolismo , Regulação para Cima , Via de Sinalização Wnt
18.
Sci Rep ; 10(1): 15154, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938975

RESUMO

Non-erosive reflux disease (NERD) pathogenesis has not been thoroughly evaluated. Here, we assessed the response of patients with NERD to proton pump inhibitor (PPI) therapy; changes in the microbiome and biologic marker expression in the esophageal mucosa were also evaluated. Patients with NERD (n = 55) received esomeprazole (20 mg) for eight weeks. The treatment response was evaluated at baseline, week four, and week eight. Esophageal mucosal markers and oropharyngeal and esophageal microbiomes were analyzed in patients who underwent upper gastrointestinal endoscopy at screening (n = 18). Complete and partial response rates at week eight were 60.0% and 32.7% for heartburn, and 61.8% and 29.1% for regurgitation, respectively. The expressions of several inflammatory cytokines, including IL-6, IL-8, and NF-κB, were decreased at week eight. Streptococcus, Haemophilus, Prevotella, Veillonella, Neisseria, and Granulicatella were prevalent regardless of the time-point (baseline vs. week eight) and organ (oropharynx vs. esophagus). The overall composition of oropharyngeal and esophageal microbiomes showed significant difference (P = 0.004), which disappeared after PPI therapy. In conclusion, half-dose PPI therapy for eight weeks could effectively control NERD symptoms. The expression of several inflammatory cytokines was reduced in the esophagus, and oropharyngeal and esophageal microbiomes in patients with NERD showed significant difference. However, the microbial compositions in the oropharynx and esophagus were not affected by PPI therapy in this study. Impact of PPI on the microbiome in patients with NERD should be more investigated in future studies.


Assuntos
Esôfago/microbiologia , Refluxo Gastroesofágico/tratamento farmacológico , Refluxo Gastroesofágico/microbiologia , Microbioma Gastrointestinal , Adulto , Idoso , Biomarcadores/metabolismo , Citocinas/metabolismo , Esomeprazol/uso terapêutico , Mucosa Esofágica/metabolismo , Mucosa Esofágica/microbiologia , Esôfago/metabolismo , Feminino , Refluxo Gastroesofágico/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Inibidores da Bomba de Prótons/uso terapêutico
19.
Adv Mater ; 32(9): e1904599, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31984587

RESUMO

The switching parameters and device performance of memristors are predominately determined by their mobile species and matrix materials. Devices with oxygen or oxygen vacancies as the mobile species usually exhibit a great retention but also need a relatively high switching current (e.g., >30 µA), while devices with Ag or Cu as cation mobile species do not require a high switching current but usually show a poor retention. Here, Ru is studied as a new type of mobile species for memristors to achieve low switching current, fast speed, good reliability, scalability, and analog switching property simultaneously. An electrochemical metallization-like memristor with a stack of Pt/Ta2 O5 /Ru is developed. Migration of Ru ions is revealed by energy-dispersive X-ray spectroscopy mapping and in situ transmission electron microscopy within a sub-10 nm active device area before and after switching. The results open up a new avenue to engineer memristors for desired properties.

20.
Ann Dermatol ; 32(5): 409-416, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33911776

RESUMO

Background: Vitiligo is a skin depigmentation disorder, for which, repigmentation treatment with combined follicular unit extraction (FUE) graft and narrowband ultraviolet B (NBUVB) is considered superior to micro-punch graft therapy. BMP4 can induce MITF expression in Neural crest stem cells (NCSCs), and α-MSH subsequently promotes the differentiation of MITF-expressing cells along the melanocyte lineage. Objective: To investigate why FUE grafting is superior to epidermal mini grafting in promoting hair follicles (HF) melanocyte cell survival and longevity, we planned the in vitro experiments HF bulge NCSCs differentiate into melanocyte precursors under the co-treatment of BMP4 and α-MSH. Methods: Cells that migrated from the HF bulge of scalp were cultured and assessed using immunofluorescence. Transcriptome analysis was performed on RNA sequencing results. Results: Basic fibroblast growth factor promotes the proliferation and survival of NCSCs, with spontaneous differentiation into SOX10+/SOX2+ glial progenitors, but not into SOX10+/MITF+ precursor melanocytes. Both BMP4 and α-MSH promoted the differentiation into MITF-expressing cells. RNA sequencing revealed a downregulation in neuregulin-1 (NRG1) and sermaphorin 3C (SEMA3C), and upregulation in WNT10A. Furthermore, FUE grafting had a source of reservoir melanocytes superior to mini- grafting in treatment for vitiligo. Conclusion: We obtained SOX10+/MITF+ precursor melanocytes through an induction of differentiation along the melanocyte lineage by BMP4 and α-MSH. According to the RNA sequencing results that NRG1 and SEMA3C were downregulated and WNT10A was upregulated, we postulated that HF NCSCs differentiated into melanocyte by co-treatment of BMP4 and α-MSH. Overall, FUE grafting is a more robust and substitutive treatment option for vitiligo.

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