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2.
Part Fibre Toxicol ; 18(1): 34, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34496918

RESUMO

BACKGROUND: Multiwalled carbon nanotubes (MWCNT) are an increasingly utilized engineered nanomaterial that pose the potential for significant risk of exposure-related health outcomes. The mechanism(s) underlying MWCNT-induced toxicity to extrapulmonary sites are still being defined. MWCNT-induced serum-borne bioactivity appears to dysregulate systemic endothelial cell function. The serum compositional changes after MWCNT exposure have been identified as a surge of fragmented endogenous peptides, likely derived from matrix metalloproteinase (MMP) activity. In the present study, we utilize a broad-spectrum MMP inhibitor, Marimastat, along with a previously described oropharyngeal aspiration model of MWCNT administration to investigate the role of MMPs in MWCNT-derived serum peptide generation and endothelial bioactivity. RESULTS: C57BL/6 mice were treated with Marimastat or vehicle by oropharyngeal aspiration 1 h prior to MWCNT treatment. Pulmonary neutrophil infiltration and total bronchoalveolar lavage fluid protein increased independent of MMP blockade. The lung cytokine profile similarly increased following MWCNT exposure for major inflammatory markers (IL-1ß, IL-6, and TNF-α), with minimal impact from MMP inhibition. However, serum peptidomic analysis revealed differential peptide compositional profiles, with MMP blockade abrogating MWCNT-derived serum peptide fragments. The serum, in turn, exhibited differential potency in terms of inflammatory bioactivity when incubated with primary murine cerebrovascular endothelial cells. Serum from MWCNT-treated mice led to inflammatory responses in endothelial cells that were significantly blunted with serum from Marimastat-treated mice. CONCLUSIONS: Thus, MWCNT exposure induced pulmonary inflammation that was largely independent of MMP activity but generated circulating bioactive peptides through predominantly MMP-dependent pathways. This MWCNT-induced lung-derived bioactivity caused pathological consequences of endothelial inflammation and barrier disruption.

3.
J Colloid Interface Sci ; 606(Pt 2): 1534-1542, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34500156

RESUMO

A series of covalent triazine frameworks (CTFs) are prepared via ionothermal synthesis for supercapacitors. Due to the feature of adjustable pore structure and rich nitrogen, CTFs with regular structure can be used as a group of model compounds to further investigate the influence of pore size and heteroatom on supercapacitors. By comparing the performance of CTFs with different pore structures and nitrogen contents, the experimental results show that BPY-CTF with high specific surface area of 2278 m2 g-1, mesopores structure, and suitable nitrogen content displays a specific capacitance of 393.6 F g-1 at 0.5 A g-1. According to the results and analysis, the existence of mesopores largely enhance the contact area between the electrode material and electrolyte, and then boost the charge transfer. On the other hand, N-doping has a prominent effect on improving the Faradaic pseudo-capacitance and conductivity for CTF electrode materials. This work will inspire further research on the development of highly efficient electrode materials for energy storage devices.

4.
Environ Int ; 157: 106856, 2021 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-34520981

RESUMO

The quality of irrigation water and drainage water is essential for local ecosystem and human health in agricultural regions. In this study, the transport analysis, source identification, and environmental risk assessment of perfluoroalkyl acids (PFAAs) were conducted in the largest irrigation area in northern China. The concentrations of the total PFAAs (ΣPFAA) ranged from 41.5 to 263 ng/L in surface water, and the short-chain perfluoroalkyl carboxylic acids (PFCAs) and perfluorooctanoic acid (PFOA), were dominant with a total contribution of 94%. Generally, the ΣPFAA levels increased from irrigation waters to drainage and receiving lake waters. PFOA showed the highest increase, with potential emission sources located in the catchment of the sub main drainage ditch D5. More PFOA (36.8 kg/y) was outflowed from Ulansuhai Lake to the Yellow River than that inflowed from the Yellow River to the irrigation district (6.15 kg/y). The results of a risk assessment indicated that avian wildlife living in Ulansuhai Lake were threatened by the PFOA and perfluorobutane sulfonate (PFBS) pollution. The estimated daily intakes (EDIs) of the sum of the PFOA, perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) through aquatic food consumption for people with the different aquatic food preferences accounted for 6-42% (urban) and 4-27% (rural) of the strictest tolerant daily intake (TDI) value. The results of this study highlight the impact of local emissions of PFAS on massive irrigation and drainage systems, and ultimately, the ecosystem and human health.

5.
Artigo em Inglês | MEDLINE | ID: mdl-34529798

RESUMO

BACKGROUND: Chlamydia trachomatis infection is the most common sexually transmitted infectious disease and carries a risk of complications. However, the optimal treatment for rectal chlamydial infection remains unclear. OBJECTIVES: To compare the efficacy of doxycycline and azithromycin for the treatment of rectal chlamydia by undertaking a systematic review and meta-analysis of published data. METHODS: We searched PubMed, EMBASE, Cochrane Library, Web of Science and clinicaltrials.gov databases from inception to 7 July 2021 for randomized controlled trials (RCTs) and observational studies that compared the efficacy of doxycycline and single-dose azithromycin on rectal chlamydia cure rates. Data were synthesized using a random-effects model, and subgroup analysis was conducted. RESULTS: All included studies were conducted in developed countries. Two RCTs and nine observational studies, with a total of 2457 patients, were analysed. Doxycycline had a higher microbiological cure rate than azithromycin (risk ratio = 1.21; 95% CI = 1.15-1.28; P < 0.05). Pooled results from two RCTs also revealed a higher microbiological cure rate for doxycycline than azithromycin (risk ratio = 1.27; 95% CI = 1.20-1.35; P < 0.05). The results remained consistent in subgroups of different study designs, countries and sexes. CONCLUSIONS: On the basis of our findings, we recommend doxycycline rather than azithromycin as a first-line treatment for rectal chlamydia in developed countries. More RCTs from developing countries are warranted.

6.
Brain Res ; : 147662, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34529965

RESUMO

Stroke is a fatal disease with high disability and mortality and there is no credible treatment for stroke at present. Studies on stroke are extensively developed to explore the underlying mechanisms of ischemic and reperfusion injuries. Herein, we investigated the functions of microRNA let-7f (also termed let-7f-5p) in vascular endothelial cell dysfunction. The bEnd.3 cells were stimulated with oxygen-glucose deprivation and reoxygenation (OGD/R) to mimic cell injury in vitro. CCK-8 assays, flow cytometry and western blot analyses were conducted to examine the viability and apoptosis of bEnd.3 cells. Reverse transcription quantitative polymerase chain reaction analyses were employed to measure RNA expression. Endothelial cell permeability in vitro assay was employed to assess endothelial permeability of bEnd.3 cells, and expression levels of proteins associated with cell apoptosis or blood-brain barrier (BBB) were detected by western blot analyses. Luciferase reporter assay was conducted to explore the combination between let-7f and HMGA2. We found that OGD/R induced injuries on endothelial cells (bEnd.3) by decreasing cell viability and promoting cell apoptosis. Let-7f exhibited low expression in bEnd.3 cells under OGD/R. Let-7f overexpression increased the viability of bEnd.3 cells and inhibited cell apoptosis. In addition, the endothelial permeability of bEnd.3 cells was increased by OGD/R and reversed by let-7f overexpression. The levels of tight junction proteins (ZO-1 and occludin) were downregulated by OGD/R and then reversed by let-7f overexpression. Mechanistically, HMGA2 is a target gene of let-7f and its expression was negatively regulated by let-7f. Rescue assays revealed that HMGA2 overexpression reversed the effects of let-7f overexpression on cell viability, cell apoptosis, endothelial permeability, and BBB function. In conclusion, let-7f alleviates vascular endothelial cell dysfunction by downregulating HMGA2 expression under OGD/R.

8.
Artigo em Inglês | MEDLINE | ID: mdl-34519471

RESUMO

To date, it remains a central challenge to achieve electroluminescence in both positive and negative half cycles of alternating-current (AC) voltage for a light-emitting device. Herein, we successfully demonstrated a novel structure to construct a real AC quantum dot light-emitting device (QLED) with two charge generation layers (CGLs) consisting of the poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/ZnO nanoparticle bilayer structure. Besides the conventional driving way with power input from a pair of opposite electrodes, this AC QLED can also work in the manner of in-planar-electrode driving mode, achieving simultaneous electroluminescence of each pixel. By employing a bilayer emissive layer composed of red and green quantum dots, the emission color of the AC QLED can be tuned by both the polarity and amplitude of the driving voltage. Leveraging the excellent electron injection and negligible voltage consumption from the CGLs, this QLED can be turned on at a record low voltage of 5.6 V. We believe that this AC QLED can provide a platform for the realization of simple and smart plug-and-play QLED-based display and lighting systems.

9.
ChemSusChem ; 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34520128

RESUMO

Water electrolysis is considered to be one of the most promising technologies to produce clean fuels. However, its extensive realization critically depends on the progress in cost-effective and high-powered oxygen evolution reaction (OER) electrocatalysts. As a member of the big family of two-dimensional (2D) materials, nanostructured layered double hydroxides (nLDHs) have made significant processes and continuous breakthroughs for OER electrocatalysis. In this review, we discuss the advancements in designing nLDHs for OER in recent years with a unique focus on their electronic modulations and in situ analysis on catalytic processes. We begin with a brief discussion on different synthetic methodologies of nLDHs, including "bottom-up" and "top-down" approaches. Then the general strategies to enhance the catalytic performances of nLDHs reported so far have been summarized, including compositional substitution, heteroatom doping, vacancy engineering, and amorphous/crystalline engineering. Furthermore, we concluded the in situ OER processes and mechanism analysis on engineering efficient nLDHs electrocatalysts. Finally, the research trends, perspectives, and challenges on designing nLDHs have also been carefully outlined. We believe that this progress review may offer enlightening experimental/theoretical guidance for designing highly catalytic active nLDHs and provide new directions to promote their future prosperity for practical utilization in water splitting.

10.
Biomater Sci ; 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34494042

RESUMO

Engineering cellular membranes with functional molecules provides an attractive strategy to manipulate cellular behaviors and functionalities. Currently, synthetic deoxyribonucleic acid (DNA) has emerged as a promising molecular tool to engineer cellular membranes for biomedical applications due to its molecular recognition and programmable properties. In this review, we summarized the recent advances in anchoring DNA on the cellular membranes and their applications. The strategies for anchoring DNA on cell membranes were summarized. Then their applications, such as immune response activation, receptor oligomerization regulation, membrane structure mimicking, cell-surface biosensing, and construction of cell clusters, were listed. The DNA-enabled intelligent systems which were able to sense stimuli such as DNA strands, light, and metal ions were highlighted. Finally, insights regarding the remaining challenges and possible future directions were provided.

11.
Sci Total Environ ; 801: 149785, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34467934

RESUMO

Nitrite-dependent anaerobic methane oxidation (n-damo) catalyzed by Candidatus Methylomirabilis oxyfera (M. oxyfera)-like bacteria is a new pathway for the regulation of methane emissions from paddy fields. Elevated atmospheric CO2 concentrations (e[CO2]) can indirectly affect the structure and function of microbial communities. However, the response of M. oxyfera-like bacteria to e[CO2] is currently unknown. Here, we investigated the effect of e[CO2] (ambient CO2 + 200 ppm) on community composition, abundance, and activity of M. oxyfera-like bacteria at different depths (0-5, 5-10, and 10-20 cm) in paddy fields across multiple rice growth stages (tillering, jointing, and flowering). High-throughput sequencing showed that e[CO2] had no significant effect on the community composition of M. oxyfera-like bacteria. However, quantitative PCR suggested that the 16S rRNA gene abundance of M. oxyfera-like bacteria increased significantly in soil under e[CO2], particularly at the tillering stage. Furthermore, 13CH4 tracer experiments showed potential n-damo activity of 0.31-8.91 nmol CO2 g-1 (dry soil) d-1. E[CO2] significantly stimulated n-damo activity, especially at the jointing and flowering stages. The n-damo activity and abundance of M. oxyfera-like bacteria increased by an average of 90.9% and 50.0%, respectively, under e[CO2]. Correlation analysis showed that the increase in soil dissolved organic carbon content caused by e[CO2] had significant effects on the activity and abundance of M. oxyfera-like bacteria. Overall, this study provides the first evidence for a positive response of M. oxyfera-like bacteria to e[CO2], which may help reduce methane emissions from paddy fields under future climate change conditions.

12.
Nanoscale ; 13(32): 13786-13794, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34477653

RESUMO

Removal of nitrate in wastewater is of great importance to environmental protection and humanity. However, the competitive reaction of hydrogen evolution (HER), which could occupy most active sites of the electrocatalyst, is one of the big challenges for nitrate removal. In this study, a novel zeolitic imidazolate framework-8 film engineered bismuth nanosheet electrocatalyst (ZIF-8/Bi-CC) was designed and synthesized for the electrochemical reduction of nitrate. The water contact angle and electrochemical tests demonstrated that the construction of the hydrophobic ZIF-8 film effectively weakened the competition of HER. And the nitrate removal efficiency and ammonium selectivity increased by 25.9% and 34.2% respectively after bismuth nanosheets were embedded into the ZIF-8 film. Besides, the bismuth concentration detection results indicated that the ZIF-8 film as the protective shell could effectively prevent the leaching of bismuth into the solution. More importantly, the final nitrate removal rate of ZIF-8/Bi-CC was close to 90% after 5 h when treating actual garbage fly ash wastewater, the NITRR efficiency stability and the obtained product were confirmed by five electrochemical cycles. The metal-organic framework film engineered electrocatalyst is a promising strategy for designing a new catalyst for the removal of nitrate in industrial wastewater.

13.
BMC Infect Dis ; 21(1): 902, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34479483

RESUMO

BACKGROUND: Airway malacia is an important cause of noisy breathing, recurrent wheezing and respiratory infections, chronic coughing, and episodes of respiratory distress in young children. As the clinical manifestations of airway malacia are not common, many clinicians have insufficient understanding of this disease. So the purpose of this study is to summarize the pathogenic bacteria and clinical manifestations of airway softening complicated with pneumonia in children. METHODS: Children hospitalized with airway malacia complicated by pneumonia were eligible for enrollment from January 1, 2013 to December 31, 2019. Medical records of patients were reviewed for etiology, clinical characteristics, and laboratory examination results. RESULTS: A total of 164 pneumonia patients with airway malacia were admitted. The male-to-female ratio was 3:1. The age of patients ranged from 1 month to 4 years old. The median age was 6 (3-10) months. The most commonly detected pathogen were Mycoplasma pneumoniae (25/164, 15.24%), Streptococcus pneumoniae (18/164, 10.98%), and respiratory syncytial virus (16/164, 9.76%). Common signs among the 164 patients with confirmed airway malacia included cough (98.78%), wheezing (67.07%), fever (35.37%), intercostal retractions (23.17%), dyspnea (10.98%), cyanosis (11.11%), and crackles (50%). Compared with those without airway malacia, the incidence of premature delivery and mechanical ventilation was higher, and the duration of symptoms before admission (median, 13.5 d) and hospital stay (median 10.0 d) were longer. Of the children with pneumonia, 11.59% of those with airway malacia required supplemental oxygen compared with 4.88% of those without airway malacia (p < 0.05). CONCLUSION: The median age of children with airway malacia was 6 months. The most common pathogen in patients with airway malacia complicated by pneumonia was Mycoplasma pneumoniae. Patients with airway malacia complicated by pneumonia often presented with a longer disease course, more severe symptoms, and had delayed recovery.

14.
BMC Genomics ; 22(1): 641, 2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34481466

RESUMO

BACKGROUND: Stroke can induce cardiac dysfunction in the absence of primary cardiac disease; however, the mechanisms underlying the interaction between the neurological deficits and the heart are poorly understood. The objective of this study was to investigate the effects of stroke on cardiac function and to identify the transcriptome characteristics of the heart. RESULTS: Stroke significantly decreased heart weight/tibia length ratio and cardiomyocyte cross-sectional areas and increased atrogin-1 and the E3 ubiquitin ligase MuRF-1, indicating myocardial atrophy in MCAO-induced mouse hearts. RNA sequencing of mRNA revealed 383 differentially expressed genes (DEGs) in MCAO myocardium, of which 221 were downregulated and 162 upregulated. Grouping of DEGs based on biological function and quantitative PCR validation indicated that suppressed immune response and collagen synthesis and altered activity of oxidoreductase, peptidase, and endopeptidase may be involved in MCAO-induced cardiomyopathy. The DEGs were mainly distributed in the membrane or extracellular region of cardiomyocytes and acted as potential mediators of stroke-induced cardiac dysregulation involved in cardiac atrophy. CONCLUSION: Stroke induced a unique transcriptome response in the myocardium and resulted in immediate cardiac atrophy and dysfunction.


Assuntos
Isquemia Encefálica , Cardiopatias , AVC Isquêmico , Acidente Vascular Cerebral , Animais , Isquemia Encefálica/patologia , Cardiopatias/patologia , Camundongos , Atrofia Muscular , Miócitos Cardíacos , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/patologia , Transcriptoma
15.
Nurs Open ; 8(3): 1077-1088, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34482663

RESUMO

OBJECTIVES: The aim of this analysis was to assess the prevalence of clinical features, comorbidities, complications and treatment options in the patients with COVID-19 and compare incidence of these clinical data in severe and non-severe patients. DESIGN: Systemic review and Meta-analysis. METHODS: PubMed, Embase, Scopus and Web of Sciences databases were searched to identify relevant papers until 20 July 2020. All studies comparing clinical data of severe and non-severe patients of COVID-19 were included. Heterogeneity across included studies was determined using Cochrane's Q test and the I2 statistic. Results were expressed as odds ratio with accompanying 95% confidence intervals. RESULTS: Twelve studies with 3,046 patients were included. The result showed the most prevalent clinical symptoms were fever 88.3%, cough 62.2%, fatigue 39.5% and dyspnoea 31.5%. Further meta-analysis showed incidence of fever, cough, fatigue and dyspnoea was higher in severe patients. The most prevalent comorbidities were hypertension 22.6%, diabetes 11.5%, cardiovascular disease 10.3% and cancer 2.5%. We found that compared with non-severe patients, the symptoms, existing comorbidities and complications are prevalent in severe COVID-19 patients. Future well-methodologically designed studies from other populations are strongly recommended.


Assuntos
COVID-19 , Diabetes Mellitus , Comorbidade , Tosse , Humanos , SARS-CoV-2
16.
Parasit Vectors ; 14(1): 455, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488863

RESUMO

BACKGROUND: Harnessing helminth-based immunoregulation is a novel therapeutic strategy for many immune dysfunction disorders, including inflammatory bowel diseases (IBDs). We previously identified a small molecule peptide from Schistosoma japonicum and named it SJMHE1. SJMHE1 can suppress delayed-type hypersensitivity, collagen-induced arthritis and asthma in mice. In this study, we assessed the effects of SJMHE1 on dextran sulfate sodium (DSS)-induced acute and chronic colitis. METHODS: Acute and chronic colitis were induced in C57BL/6 mice by DSS, following which the mice were injected with an emulsifier SJMHE1 or phosphate-buffered saline. The mice were then examined for body weight loss, disease activity index, colon length, histopathological changes, cytokine expression and helper T (Th) cell subset distribution. RESULTS: SJMHE1 treatment significantly suppressed DSS-induced acute and chronic colitis, improved disease activity and pathological damage to the colon and modulated the expression of pro-inflammatory and anti-inflammatory cytokines in splenocytes and the colon. In addition, SJMHE1 treatment reduced the percentage of Th1 and Th17 cells and increased the percentage of Th2 and regulatory T (Treg) cells in the splenocytes and mesenteric lymph nodes of mice with acute colitis. Similarly, SJMHE1 treatment upregulated the expression of interleukin-10 (IL-10) mRNA, downregulated the expression of IL-17 mRNA and modulated the Th cell balance in mice with chronic colitis. CONCLUSIONS: Our data show that SJMHE1 provided protection against acute and chronic colitis by restoring the immune balance. As a small molecule, SJMHE1 might be a novel agent for the treatment of IBDs without immunogenicity concerns.

17.
J Interv Cardiol ; 2021: 8837644, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34497479

RESUMO

Background: The clinical impact of the distressed communities index (DCI), a composite measure of economic well-being based on the U.S. zip code, is becoming increasingly recognized. Ranging from 0 (prosperous) to 100 (distressed), DCI's association with cardiovascular outcomes remains unknown. We aimed to study the association of the DCI with presentation and outcomes in adults with severe symptomatic aortic stenosis (AS) undergoing transcatheter aortic valve intervention (TAVR) in an affluent county in New York. Methods: The study population included 286 patients with severe symptomatic AS or degeneration of a bioprosthetic valve who underwent TAVR with a newer generation transcatheter heart valve (THV) from December 2015 to June 2018 at an academic tertiary medical center. DCI for each patient was derived from their primary residence zip code. Patients were classified into DCI deciles and then categorized into 4 groups. The primary and secondary outcomes of interest were 30-day, 1-year, and 3-year mortality, respectively. Results: Among 286 patients studied, 26%, 28%, 28%, and 18% were categorized into DCI groups 1-4, respectively (DCI <10: n = 73; DCI 10-20: n = 81; DCI 20-30: n = 80; DCI >30: n = 52). Patients in group 4 were younger with worse kidney function compared to patients in groups 1 and 2. They also had smaller aortic annuli and were more likely to receive a smaller THV. No significant difference in hospital length of stay or distribution of in-hospital, 30-day, 1-year, and 3-year mortality was demonstrated. Conclusions: While the DCI was associated with differences in the clinical and anatomic profile, it was not associated with differences in clinical outcomes in this prospective observational study of adults undergoing TAVR suggesting that access to care is the likely discriminator.

18.
Inorg Chem ; 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34495661

RESUMO

In this work, a tunable luminescence color from yellow to orange of photoluminescence (PL), long persistent luminescence (LPL), and photostimulated luminescence (PSL) is successfully achieved in BaGa2O4:Bi3+ phosphors with the introduction of Sr2+ ions as secondary cations. It is confirmed that broad-band emissions located at 500 and 600 nm originate from the occupation of Bi3+ ions at different lattice sites in the BaGa2O4 host matrix. The replacement of Sr2+ for Ba2+ ions makes the emission red-shift from 600 to 650 nm; moreover, two additional emissions appeare at 743 and 810 nm due to the occupational preference of Bi3+ ions at Ga3+ sites. Furthermore, the doped Sr2+ ions promote the reconstruction of the trapping centers, which conduces to the fundamental improvement of the optical storage capacity behavior of Bi3+-doped phosphors. Our results clarify the dependence of the luminescence performance on the crystal sites of Bi3+ ions with fascinating broad-band emissions in the BaGa2O4:0.01Bi3+ host matrix and will benefit the design and exploration of Bi3+-doped solid solutions for optical storage applications.

19.
Exp Mol Med ; 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34497345

RESUMO

TAZ, as a crucial effector of Hippo pathway, is required for spermatogenesis and fertilization, but little is known regarding its physiological function in uterine decidualization. In this study, we showed that TAZ was localized in the decidua, where it promoted stromal cell proliferation followed by accelerated G1/S phase transition via Ccnd3 and Cdk4 and induced the expression or activity of stromal differentiation markers Prl8a2, Prl3c1 and ALP, indicating the importance of TAZ in decidualization. Knockdown of TAZ impeded HB-EGF induction of stromal cell proliferation and differentiation. Under oxidative stress, TAZ protected stromal differentiation against oxidative damage by reducing intracellular ROS and enhancing cellular antioxidant capacity dependent on the Nrf2/ARE/Foxo1 pathway. TAZ strengthened the transcriptional activity of Nrf2 which directly bound to the antioxidant response element (ARE) of Foxo1 promoter region. Additionally, silencing TAZ caused accumulation of intracellular ROS through heightening NOX activity whose blockade by APO reversed the disruption in stromal differentiation. Further analysis revealed that TAZ might restore mitochondrial function, as indicated by the increase in ATP level, mtDNA copy number and mitochondrial membrane potential with the reduction in mitochondrial superoxide. Additionally, TAZ modulated the activities of mitochondrial respiratory chain complexes I and III whose suppression by ROT and AA resulted in the inability of TAZ to defend against oxidative damage to stromal differentiation. Moreover, TAZ prevented stromal cell apoptosis by upregulating Bcl2 expression and inhibiting Casp3 activity and Bax expression. In summary, TAZ might mediate HB-EGF function in uterine decidualization through Ccnd3 and ameliorate oxidative damage to stromal cell differentiation via Nrf2/ARE/Foxo1 pathway.

20.
Artigo em Inglês | MEDLINE | ID: mdl-34472846

RESUMO

Composites based on a shape-memory polymer doped with conductive particles are considered as soft actuators for artificial muscles and robots. Low-voltage actuating is expected to reduce equipment requirement and safety hazards, which requires a highly conductive particle content but weakens the reversible deformation. The spatial distribution of the conductive particle is key to decreasing the actuating voltage and maintaining the reversible deformation. Herein, an approach of fabricating a low-voltage actuator that can perform various biomimetic locomotions by spraying and hot pressing is reported. Carbon nanotubes (CNTs) are enriched inside the surface layer of poly(ethylene-co-vinyl acetate) (EVA) to form a high-density conductive network without degradation of the reversible deformation. The bilayer CNT/EVA actuator exhibits a reversible transformation of more than 10% even with 100 cycles, which requires an applied voltage of just 15 V. Taking advantage of the reprogrammability of the CNT/EVA actuator and reversible shift between the different shapes, different biomimetic locomotions (sample actuator, gripper, and walking robot) are demonstrated without any additional mechanical components. A scheme combining the electrical properties and the shape-memory effect provides a versatile strategy to fabricate low-voltage-actuated polymeric actuators, providing inspiration in the development of electrical soft actuators and biomimetic devices.

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