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Fluorophore is essential to enable the fluorescence and optical switching in most of polymer gels. Herein, a novel concept is proposed to develop a fluorophore-free organogel that is capable of generation of blue fluorescence at transparent state, while it proceeds with optical switching from blue to purple upon phase transition into non-transparent state in water. Ammonium persulphate (APS) is utilized to initiate co-crosslinking of hydrophilic acrylamide (AM) and hydrophobic 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA) in dimethyl sulphoxide (DMSO) to give organogel of AM@HFBA at 80 °C. APS decomposes to generate not only radicals, but also ammonium bisulfate (ABS) during heating, in which the elements of ABS produce blue fluorescence (λ = 440 nm), excited by UV light (λ = 365 nm). After the phase transition into non-transparent state, light-reflection behavior at the phase-transitioned surface triggers the optical switching of the organogel from blue to purple under UV light. The optical switching is patternable and reversible, which enables the applications of organogel of AM@HFBA for information encoding/encryption and optical-switchable soft actuators. This method is universal to achieve fluorescence and optical switching for free radical polymerization-based gel systems as long as they are initiated by APS in DMSO.
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Dimetil Sulfóxido , Corantes Fluorescentes , Raios Ultravioleta , Polímeros , FluorescênciaRESUMO
Transcriptional regulation is an essential molecular machinery in controlling gene expression in diverse plant developmental processes including fruit ripening. This involves the interaction of transcription factors (TFs) and promoters of target genes. In banana, although a number of fruit ripening-associated TFs have been characterized, their number is relatively small. Here we identified a nuclear-localized basic leucine zipper (bZIP) TF, MabZIP93, associated with banana ripening. MabZIP93 activated cell wall modifying genes MaPL2, MaPE1, MaXTH23 and MaXGT1 by directly binding to their promoters. Transient over-expression of MabZIP93 in banana fruit resulted in the increased expression of MaPL2, MaPE1, MaXTH23 and MaXGT1. Moreover, a mitogen-activated protein kinase MaMPK2 and MabZIP93 were found to interact with MabZIP93. The interaction of MabZIP93 with MaMPK2 enhanced MabZIP93 activation of cell wall modifying genes, which was likely due to the phosphorylation of MabZIP93 mediated by MaMPK2. Overall, this study shows that MaMPK2 interacts with and phosphorylates MabZIP93 to promote MabZIP93-mediated transcriptional activation of cell wall modifying genes, thereby expanding our understanding of gene networks associated with banana fruit ripening.
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Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes/genética , Musa/genética , Proteínas de Plantas/metabolismo , Ativação Transcricional , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Núcleo Celular/metabolismo , Parede Celular/metabolismo , Frutas/genética , Musa/fisiologia , Fosforilação , Proteínas de Plantas/genética , Regiões Promotoras Genéticas/genéticaRESUMO
Banana fruit (Musa acuminate L.) ripening is a complex genetical process affected by multiple phytohormones and expression of various genes. However, whether plant hormone brassinosteroid (BR) is involved in this process remains obscure. In this work, three genes that encode BR core signaling components brassinazole resistant (BZR) proteins, namely MaBZR1 to MaBZR3, were characterized from banana fruit. MaBZR1-MaBZR3 exhibited both nuclear and cytoplasmic localization and behaved as transcription inhibitors. Expression analysis showed that MaBZR1/2/3 were continuously decreased as fruit ripening proceeded, indicating their negative roles in banana ripening. Moreover, gel shift and transient expression assays demonstrated that MaBZR1/2 could suppress the transcription of ethylene biosynthetic genes, including MaACS1, MaACO13 and MaACO14, which increased gradually during the banana ripening, via specifically binding to CGTGT/CG sequence in their promoters. Importantly, exogenous application of BRs promotes banana ripening, which is presumably due to the accelerated expression of MaACS1 and MaACO13/14, and consequently the ethylene production. Our study indicates that MaBZR1/2 act as transcriptional repressors of ethylene biosynthetic genes during banana fruit ripening.
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Frutas/metabolismo , Musa/metabolismo , Fatores de Transcrição/metabolismo , Etilenos/biossíntese , Frutas/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Musa/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genéticaRESUMO
OBJECTIVE: Accumulation of cyclophilin A (CyPA) within atherosclerotic lesions is thought to be implicated in the progression of atherosclerosis. However, the source of CyPA within atherosclerotic lesions is still unknown. The aim of this study is to determine the role of oxidized low-density lipoproteins (ox-LDL) in vascular smooth muscle cell (VSMC)-derived CyPA secretion and the underlying mechanism. METHODS AND RESULTS: Abundant CyPA and α-smooth muscle actin (α-SMA) expressed in atherosclerotic lesions was observed in apolipoprotein E-deficient mice. ox-LDL induced CyPA secretion from a primary culture of rat aortic smooth muscle cells in a dose- and time-dependent manner. Sulfosuccinimidyloleate, a CD36 inhibitor, prevented the ox-LDL-induced CyPA secretion. Pre-exposure to either the actin-depolymerizing agent cytochalasin D or the actin-polymerizing agent jasplakinolide inhibited CyPA secretion induced by ox-LDL. Gene silencing of vesicle-associated membrane protein 2 suppressed ox-LDL-induced CyPA secretion. ox-LDL caused the phosphorylation of myosin light chain (MLC). Inhibition of MLC by blebbistatin reversed the secretion of CyPA and the phosphorylation of MLC induced by ox-LDL. MLC kinase inhibitor ML-7 reduced the monophosphorylation of MLC but did not reduce CyPA secretion. Pretreatment with the rho-associated coiled-coil kinase (ROCK) inhibitor Y27632 blocked diphosphorylation of MLC and secretion of CyPA induced by ox-LDL. CONCLUSIONS: ox-LDL-induced CyPA secretion requires vesicle transportation, actin remodeling and ROCK-dependent diphosphorylation of MLC. VSMC-derived CyPA induced by ox-LDL may be associated with increased CyPA expression in atherosclerotic lesions.
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Doenças da Aorta/enzimologia , Aterosclerose/enzimologia , Ciclofilina A/metabolismo , Lipoproteínas LDL/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Cadeias Leves de Miosina/metabolismo , Quinases Associadas a rho/metabolismo , Actinas/metabolismo , Animais , Aorta/enzimologia , Aorta/metabolismo , Aorta/patologia , Doenças da Aorta/genética , Doenças da Aorta/patologia , Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Aterosclerose/genética , Aterosclerose/patologia , Antígenos CD36/metabolismo , Células Cultivadas , Dieta Hiperlipídica , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Masculino , Camundongos Knockout , Músculo Liso Vascular/enzimologia , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/enzimologia , Miócitos de Músculo Liso/metabolismo , Fosforilação , Interferência de RNA , Ratos , Fatores de Tempo , TransfecçãoRESUMO
Chinese patent medicines (CPMs) are commonly prescribed by clinicians in China as adjuvant therapy for diabetic retinopathy (DR). The study of network meta-analysis (NMA) aims to compare the effectiveness and safety of three CPMs plus calcium dobesilate (CD) for DR, and to explore optimal CPM for treatment of DR. Methods. Bayesian network meta-analyses were designed to evaluate the safety and effectiveness of different CPMs for the treatment of DR. Systematic Review Registration CRD42022323996. Results. A total of 23 eligible RCTs involving 1824 patients were enrolled. Compared with CD alone, Cmpound Danshen Dripping Pills (DS) + CD or Qiming Granule (QM) + CD considerably enhanced best corrected visual acuity (BCVA); DS + CD or Compound Xueshuantong Capsule (XST) + CD significantly reduced macular thickness; CPMs + CD significantly reduced the level of VEGF. In addition, DS + CD or XST + CD over QM + CD in reducing macular thickness. As for the adverse events, the differences across different CPMs were not statistically significant, and no statistically significant difference between the CPMs and CD. Conclusion. DS plus CD or QM plus CD may be better effective in improving BCVA; DS plus CD or XST plus CD may be better effective in reducing macular thickness; The combination therapy all may be better effective in reducing the level of VEGF. As for safety profile that CPMs plus CD did not increase the incidence of adverse events. The results of this study might support DS as a relatively prior adjuvant therapy option for patients with DR.
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The disruption of per- and polyfluoroalkyl substances (PFASs) on bile acid (BA) homeostasis has raised public concerns, making the evaluation of their effects and underlying mechanisms a high priority. Although the use of perfluorooctanoic acid (PFOA) has been restricted, it remains a widespread legacy PFAS in the environment. Concurrently, the use of its prevalent short-chain alternative, perfluorobutanoic acid (PFBA), is increasing, yet the toxicity assessment of PFBA remains inadequate. In this study, C57BL/6N mice were exposed to PFOA and PFBA (0.4 or 10 mg/kg body weight) by gavage for 28 days. The results showed that both PFOA and PFBA significantly increased hepatic weight, although PFBA exhibited lower bioaccumulation than PFOA in the liver. Targeted metabolomics revealed that PFOA significantly decreased total BA levels and altered their composition. Conversely, PFBA, without significantly altering total BA levels, notably changed their composition, such as increasing the proportion of cholic acid. Further investigations using in vivo and in vitro assays suggested that PFOA inhibited the expression of Cyp7A1, a key BA synthetase, potentially via PPARα activation, thereby reducing BA levels. In contrast, PFBA enhanced Cyp7A1 expression, associated with the inhibition of intestinal Farnesoid X receptor-fibroblast growth factor 15 (FXR-FGF15) pathway. This study evaluated the differences in the BA-interfering effects of PFOA and PFBA and shed light on the potential mechanisms, which will provide new insights into the health risks of legacy PFASs and their alternatives.
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OBJECTIVE: Osteopontin (OPN) is aberrantly expressed in various tumors. However, its role and detailed mechanisms in head and neck squamous cell carcinoma (HNSCC) have not been extensively described. STUDY DESIGN: Expression of OPN in HNSCC was examined at the gene and protein levels. The effect of cell proliferation ability was examined by Cell Counting Kit-8, colony formation assay, cell invasiveness by Transwell assay, the effect of OPN on protein expression of Capase-3 and Bcl2 by Western blotting, and the expression of p38MAPK signaling pathway by p38MAPK inhibitor SB203580. RESULTS: We found that OPN expression was higher in human HNSCC tissues than in adjacent tissues. Osteopontin may regulate the proliferation and invasion of HNSCC cells through the p38-MAPK signaling pathway. DISCUSSION: Our study identifies an important role for OPN in HNSCC and further demonstrates that it may regulate the proliferation and invasion of HNSCC cells by activating the p38-MAPK signaling pathway. Osteopontin may be a promising prognostic and diagnostic indicator and a potential target for cancer therapy.
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Neoplasias de Cabeça e Pescoço , Osteopontina , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Osteopontina/genética , Osteopontina/metabolismo , Sistema de Sinalização das MAP Quinases , Proliferação de Células , Linhagem Celular Tumoral , Movimento CelularRESUMO
Organosulfates (OSs) are formed from volatile organic compounds (VOCs) and their oxidation products in the presence of sulfate particles. While OSs represent an important component in secondary organic aerosol, the knowledge of their formation driving force, mechanisms, and environmental impact remain inadequately understood. In this study, we report ambient observations of C2-3 oxygenated VOCs derived OSs (C2-3 OSs) at a suburban location of Hong Kong during autumn 2016. The C2-3 OSs, including glycolaldehyde sulfate (GS), hydroxyacetone sulfate (HAS), glycolic acid sulfate (GAS), and lactic acid sulfate (LAS), were quantified/semi-quantified using offline liquid chromatography-mass spectrometry analysis of aerosol filter samples. The average sum concentration of C2-3 OSs was 36 ng/m3. Correlation analysis revealed that sulfate, surface area, and liquid water content were important factors influencing C2-3 OS formation. Online measurement with an iodide High-Resolution Time-of-Flight Chemical-Ionization Mass Spectrometer (HR-ToF-CIMS) coupled with the Filter Inlet for Gases and AEROsols (FIGAERO) was also conducted to monitor C2-3 OSs, and their potential oxygenated VOC precursors in both gas- and particle-phase, and aerosol acidity tracer simultaneously. Our measurements support that glycolaldehyde/glyoxal, hydroxyacetone, glycolic acid/glyoxal, and lactic acid/methylglyoxal are likely precursors for GS, HAS, GAS, and LAS, respectively. Additionally, we found strong correlation between C2-3 OSs and H3S2O8-, a marker for aerosol acidity, providing field observational evidence for acid-catalyzed formation of small OSs. Based on both online and offline measurements, acid-catalyzed formation mechanisms in particle/aqueous phase are proposed. Specifically, the unique structure of adjacent carbonyl and hydroxyl groups in the C2-3 oxygenated VOC precursors can facilitate the formation of (1) a five-member ring intermediate via intramolecular hydrogen bond to react with sulfur trioxide through heterogenous reaction or (2) cyclic sulfate intermediate via particle-phase reaction with sulfuric acid to generate C2-3 OSs. These proposed mechanisms provide an alternative pathway for the liquid-phase production of C2-3 OSs.
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A total of 33 potato (Solanum tuberosum L.) cultivars and breeding clones imported from the United States and two local cultivars (Yunshu 401 and Cooperation 88, CK) were planted and evaluated. To determine their suitability for processing into French fries at five locations (e1-e5) in Yunnan Province, China, we developed a comprehensive evaluation system using the analytical hierarchy process (AHP). Eleven evaluation indicators for French fry quality, yield, and agronomic characteristics with a relative importance (weight coefficients) of 0.483, 0.301 and 0.216, respectively, were used to analyze the 35 potato genotypes (designated g1-g35).The genotypes were ranked and the results revealed that (1) on the average, the 33 potato genotypes imported from the United States showed a lower performance compared to the local cultivars. Compared with the CK, they were classified as not vigorous (Mean 5.11 vs CK 7.75), matured earlier (Mean 5.79 vs CK 1.70), and had a low resistance to late blight (Mean 3735.59 vs CK 1418.55), requiring the use of fungicides to control the disease at the five trial locations. (2) The US cultivar 'Defender' (g3) ranked in the top six at all five test locations because it had higher yield (29.56 t h m-2), better fry quality (4.64), higher dry matter content (20.41%), better tuber length/width ratio (1.99), longer tubers (13.57cm), stronger plant vigor (7.17) and higher resistance to late blight (AUDPC: 3134.2). (3) By using GGEbiplot analysis, superior genotypes with high and stable yields were g3 and 'Echo Russet' (g33). 'Yunshu 401' (g34) and 'Yukon Gem' (g4) had high but not stable yields. The ideal test environments and hence experimental locations were Luquan (LQ, e2) and Lijiang (LJ, e4) which resulted in the best discrimination between genotypes among the five experimental locations in Yunnan. Overall, the developed evaluation system based on AHP and GGEbiplot analysis including 11 evaluation indicators for French fry quality, yield and agricultural traits can be a model for evaluation and promotion of new French fry cultivars, and evaluating and selecting the test location.
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Background: Many studies have examined how to achieve better outcomes in myocardial infarction (MI) patients with mild obesity or who are overweight. However, the influence of a high-fat diet (HFD) and the underlying mechanisms by which it can affect ventricular remodeling following MI are poorly understood. This study investigated the impact of a 12-week HFD on the left ventricular (LV) remodeling of permanent MI models and immune cell involvement. Methods: Male C57BL/6J mice were fed HFD or normal diet (ND). After 8 weeks of feeding, mice underwent cardiac left anterior descending coronary artery ligation, and the same diet was continued for a further 4 weeks. Cardiac structure and function were detected using echocardiography. Cardiac fibrosis was evaluated using histological staining at 7 and 28 days post-MI. Infiltration of various immune cells was examined using flow cytometry and immunofluorescence at 7 days post-MI. Results: Compared with a ND, the 12-week HFD feeding significantly alleviated ventricular remodeling following MI. HFD mice showed reduced infiltration of neutrophils, a higher proportion of M2/M1 macrophages, decreased conventional and monocyte-derived dendritic cells (moDCs) in the injured myocardium, and elevated levels of regulatory T cells (Tregs). Further investigation of dendritic cells (DCs) phenotypes indicated downregulated expression of major histocompatibility complex class II (MHCII). It also showed costimulatory molecules CD40 and CD86 on conventional and moDCs in mediastinal lymph nodes (mLNs). Conclusions: This study demonstrated the protective effect of a 12-week HFD on ventricular remodeling following MI via the alleviation of local inflammation.
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Untethered robots with smart human-machine interactions can execute complex activities such as target cargo delivery or assembly of functional scaffolds. However, it remains challenging for fabricating microscale hollow hydrogel robots that can go with autonomous transformation of their geometric formations to adapt to unstructured environments. We herein report hydrogel-based microscopic hollow swarming spheres (HSSs) with anisotropic/isotropic alignments of Fe3O4 particles in the porous wall that can navigate under complex topography conditions by altering their geometric formation, including passing around or jumping over obstacles, assembling into various formation patterns, and swimming in a high-viscosity system. We introduce HSSs into a catalytic reaction model, in which HSSs as a catalyst can shift between water and oil phases to initiate or terminate the decomposition reaction of H2O2. This dynamic catalysis is expected to construct free-radical "living" polymerization for controlling the reaction rate and polymer dispersity index in the future.
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BACKGROUND: Acute lumbar sprain (ALS) frequently occurs in the young and middle-aged people, causing great harm to people's quality of life. The systematic review program was designed to describe a meta-analysis to evaluate the efficacy and safety of wrist-ankle acupuncture (WAA) in treating patients with ALS. METHODS AND ANALYSIS: Our systematic review will search electronically and manually for WAA treatments for ALS by August, 2020, regardless of publication status and language. Databases include: MEDLINE, PubMed, EMBASE, Springer, Web of Science, Cochrane Library, WHO International Clinical Trial Registration Platform (ICTRP), Chinese Medicine Database (TCMD), China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), China Science Journal Database (VIP), and Wanfang Database. Other sources of information, including bibliographies and meeting minutes for identified publications, will also be searched. Manually search for grey literature, including unpublished conference articles. Any clinical randomized controlled trials related to WAA treatments for ALS, regardless of publication status and language limitations, will be included in the study. Study selection, data extraction, and research quality assessment will be done independently by 2 researchers. The primary outcome included the effective rate and visual analogue scale (VAS) or other validated scales used to relieve pain after the treatment. If possible, meta-analysis will be performed using RevMan V.5.3 statistical software. If it is not suitable for meta-analysis, a descriptive analysis or subgroup analysis is performed. RESULTS: This study will provide a comprehensive review and evaluation of the available evidence for the treatment of ALS using WAA. CONCLUSION: This study will provide new evidence to evaluate the effectiveness and side effects of WAA on ALS. Because the data is not personalized, no formal ethical approval is required. REGISTRATION NUMBER: PROSPERO CRD42020162945.
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Terapia por Acupuntura/métodos , Tornozelo , Região Lombossacral/lesões , Entorses e Distensões/terapia , Punho , Humanos , Medição da Dor , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Metanálise como AssuntoRESUMO
This study proposed an investigation-based multiple-criteria coordinated model to evaluate the sustainable development of urban public transport (PT) infrastructure, based on economic, social and environmental data from 2009 to 2019. The main problem with the traditional approach for assessing urban PT development is that economic and social benefits are considered individually, but also attention to environmental factors and coordination among the three issues are nearly overlooked. This leads to the likelihood of inaccuracies in the handling/assessment of sustainable development or an imbalance among the attributes in different cities. An investigation-based coordinated model was introduced in which a survey of 35 sub-criteria was conducted to derive the criteria necessary for coupling/coordination. A case study involving 13 cities in Jiangsu Province, China, illustrated the problems in coordinating PT systems and verified the efficacy of the proposed approach. With employing the entropy method, this study validated coordination of the PT infrastructure development of various cities in a balanced manner and used panel regression formulas to analyse the theoretical gap and empirical bottlenecks existing among economic, social and environmental benefits. With the findings of the study, the data-based investigation from 13 cities enabled the city planners/managers (including ones from other cities with similar urban levels) to give the individual priority between the ternary benefits, advance technology, allow big data-based informatisation and implement near-future autonomous PT vehicles.
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Desenvolvimento Econômico , Desenvolvimento Sustentável , China , Cidades , EmpregoRESUMO
Carotenoids are a class of bioactive compounds that exhibit health-promoting properties for humans, but their regulation in bananas during fruit ripening remains largely unclear. Here, we found that the total carotenoid content continued to be elevated along the course of banana ripening and peaked at the ripening stage followed by a decrease, which is presumably caused by the transcript abundances of carotenoid biosynthetic genes MaLCYB1.1 and MaLCYB1.2. Moreover, a ripening-inducible transcription factor MaSPL16 was characterized, which was a nuclear protein with transactivation activity. Transient transformation of MaSPL16 in banana fruits led to enhanced transcript levels of MaLCYB1.1 and MaLCYB1.2 and hence the total carotenoid accumulation. Importantly, MaSPL16 stimulated the transcription of MaLCYB1.1 and MaLCYB1.2 through directly binding to their promoters. Collectively, our findings indicate that MaSPL16 behaves as an activator to modulate banana carotenoid biosynthesis, which may provide a new target for molecular improvement of the nutritional and bioactive qualities of agricultural crops that accumulate carotenoids.
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Carotenoides/metabolismo , Frutas/crescimento & desenvolvimento , Liases Intramoleculares/genética , Musa/metabolismo , Proteínas de Plantas/genética , Fatores de Transcrição/metabolismo , Frutas/enzimologia , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Liases Intramoleculares/metabolismo , Musa/enzimologia , Musa/genética , Musa/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: Cyclophilin A (CyPA) plays an important role in the progression of atherosclerosis. Additionally, it has been reported that lysosomal function is markedly impaired in atherosclerosis induced by oxidized low-density lipoprotein (ox-LDL). As the CyPA degradation pathway remains to be elucidated, we aimed to uncover the role of lysosomes and ox-LDL in the degradation of CyPA. METHODS: We exploited RNA interference (RNAi) in combination with either the lysosomal inhibitor chloroquine (CQ) or the proteasomal inhibitor MG-132 to examine CyPA turnover. We also investigated the role of ox-LDL in lysosomal function and the CyPA degradation pathway and determined whether CyPA interacts with the selective autophagy adaptor p62. RESULTS: CQ markedly reversed the CyPA downregulation induced by RNAi and increased intracellular levels of LC3 and p62. MG-132 significantly suppressed polyubiquitinated protein degradation but did not inhibit RNAi-induced CyPA downregulation. Additionally, neither CQ nor MG-132 influenced the gene-silencing efficiency of CyPA siRNA. Moreover, ox-LDL induced cytosolic accumulation of p62 was inconsistent with increased expression of LC3-II. Meanwhile, ox-LDL inhibited RNAi-induced downregulation of CyPA. Immunofluorescence indicated colocalization of endogenous CyPA with ubiquitin and with p62 in response to CQ treatment, and co-immunoprecipitation analysis confirmed interaction between CyPA and p62. CONCLUSION: CyPA is degraded by a lysosome-dependent pathway that may involve p62-mediated selective autophagy. Furthermore, ox-LDL modulates the degradation of CyPA via its inhibitory role in lysosomes, contributing to increased expression of CyPA in atherosclerotic plaques.
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We propose a pre-patterning and post-oxidation-crosslinking protocol to prepare a humidity-sensing actuator. Fe(0) particles (FeP) are introduced into a sodium alginate (SA) film under a magnetic field (15 mT) to achieve directional pre-patterning, followed by treatment in hydrochloric acid that oxidates FeP into Fe2+, and triggers the crosslinking between Fe2+ and SA, which provides the actuator with differential mechanical tensors and induces controlled response to humidity.
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Hollow hydrogel tubes that are capable of maintaining their flexibility and structural stability in extreme temperature conditions have potential for use in biomedical scaffolds, carriers, and soft robotics over a wide temperature range. However, the preparation of hollow hydrogel tubes still remains challenging because it normally requires templates or complex devices and it is hard to endow the hollow tubes with antifreezing heat-resistant capabilities. We report a protocol that does not require a template or complex devices, in which sodium alginate film strips are immersed in an aqueous mixture of CaCO3, CaCl2, NaHCO3, and HCl, which results in the manufacture of hollow tubes in 30 min. These hollow tubes are functionalized by glycerol and poly(ethylene glycol), which provides the tubes with antifreezing heat-resistant performances and enables them to keep their flexibility and hollow structures from -70 to 120 °C. This is the first report on antifreezing heat-resistant hollow hydrogel tubes, to the best of our knowledge. Such hollow tubes as carriers can control the sublimation of a mothball at a rate of 1.1 mg/h, which is one-tenth of the sublimating rate of an unloaded mothball. This sublimating rate reduces the hazard to environments along with maintaining the repellent effects. As the tube is a honey carrier, it enables the sustainable release of the honey over 800 min with a high efficacy for tricking and capturing ants. The simple applications demonstrate that the antifreezing heat-resistant hollow tubes might be feasible as carriers for the controlled release in extremely cold/hot environments.
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An active film was prepared by incorporating cortex Phellodendron extract (CPE, an active agent) into a soybean protein isolate (SPI). Different concentrations of CPE (0%, 10%, 12.5%, 15%, 17.5%, 20%, or 22.5%, w/w, based on SPI) were mixed into the films characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetry, tensile tests, and barrier properties. The rheological properties of the solutions were also tested. The effects of the CPE content on the antibacterial and antioxidant activities of the films were examined. The results indicated that new hydrogen bonds formed between molecules in the films, and the crystallinity of the films decreased. The incorporation of CPE had no significant influence on the thermal stability of the films. Films containing 15% CPE had the maximum tensile strength of 6.00 MPa. The barrier properties against water vapor, oxygen, and light enhanced with the incorporation of CPE. The antioxidant activity of the SPI film was also improved. The films were effective against Staphylococcus aureus (S. aureus, Gram-positive bacteria). These results suggest that the SPI/CPE film can potentially extend the shelf lives of foods.
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We report the first example of a simple, yet robust, reproducible and scalable method for direct conversion of sodium alginate (SA) films to multibranched hydrogel tubes (HTs) in "one-pot" reaction of buffered aqueous solution. This method allows for construction of branched hollow HTs of any shape and arbitrary size, and enables further functionalization for application requirements.
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Soft robots, sensors, and energy harvesters require materials that are capable of converting external stimuli to visible deformations, especially when shape-programmable deformations are desired. Herein, we develop a polymer film that can reversibly respond to humidity, heating, and acetone vapors with the generation of shape-programmable large deformations. Poly(vinylidene fluoride) film, capable of providing acetone responsiveness, is designed with microchannel patterns created on its one side by using templates, and the microchannels-patterned side is then treated with hygroscopic 3-aminopropyltriethoxysilane (APTES) to give humidity/heating-responsive elements. The APTES-modified microchannels lead to anisotropic flexural modulus and hygroscopicity in the film, resulting in the shape-programmed kinematics depending on the orientations of surface microchannels. As the microchannels align at oblique/right angles with respect to the long axis of the film strips, the coiling/curling motions can be generated in response to the stimuli, and the better motion performances are found in humidity- and heating-driven systems. This material utilized in self-adaptive soft robots exhibits prominent toughness, powerful strength, and long endurance for converting humidity and heat to mechanical works including transportation of lightweight objects, automatic sensing cap, and mimicking crawling in nature. We thus believe that this material with shape-programmable multisensing capability might be suitable for soft machines and robotics.