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YAP/TAZ transcriptional co-activators play pivotal roles in tumorigenesis. In the Hippo pathway, diverse signals activate the MST-LATS kinase cascade that leads to YAP/TAZ phosphorylation, and subsequent ubiquitination and proteasomal degradation by SCFß-TrCP . When the MST-LATS kinase cascade is inactive, unphosphorylated or dephosphorylated YAP/TAZ translocate into the nucleus to mediate TEAD-dependent gene transcription. Hippo signaling-independent YAP/TAZ activation in human malignancies has also been observed, yet the mechanism remains largely elusive. Here, we report that the ubiquitin E3 ligase HERC3 can promote YAP/TAZ activation independently of its enzymatic activity. HERC3 directly binds to ß-TrCP, blocks its interaction with YAP/TAZ, and thus prevents YAP/TAZ ubiquitination and degradation. Expression levels of HERC3 correlate with YAP/TAZ protein levels and expression of YAP/TAZ target genes in breast tumor cells and tissues. Accordingly, knockdown of HERC3 expression ameliorates tumorigenesis of breast cancer cells. Our results establish HERC3 as a critical regulator of the YAP/TAZ stability and a potential therapeutic target for breast cancer.
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Proteínas Adaptadoras Transductoras de Señales , Neoplasias de la Mama , Humanos , Femenino , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Transactivadores/genética , Transactivadores/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Señalizadoras YAP , Proteínas con Repetición de beta-Transducina/genética , Proteínas con Repetición de beta-Transducina/metabolismo , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transformación Celular Neoplásica/genética , Carcinogénesis/genética , Ubiquitinación , Neoplasias de la Mama/genética , Ubiquitinas/metabolismo , Ligasas/genética , Fosfoproteínas/genética , Fosfoproteínas/metabolismoRESUMEN
BACKGROUND: Lumbar-iliac fixation (LIF) is a common treatment for Tile C1.3 pelvic fractures, but different techniques, including L4-L5/L5 unilateral LIF (L4-L5/L5 ULIF), bilateral LIF (BLIF), and L4-L5/L5 triangular osteosynthesis (L4-L5/L5 TOS), still lack biomechanical evaluation. The sacral slope (SS) is key to the vertical shear of the sacrum but has not been investigated for its biomechanical role in lumbar-iliac fixation. The aim of this study is to evaluate the biomechanical effects of different LIF and SS on Tile C1.3 pelvic fracture under two-legged standing load in human cadavers. METHODS: Eight male fresh-frozen human lumbar-pelvic specimens were used in this study. Compressive force of 500 N was applied to the L4 vertebrae in the two-legged standing position of the pelvis. The Tile C1.3 pelvic fracture was prepared, and the posterior pelvic ring was fixed with L5 ULIF, L4-L5 ULIF, L5 TOS, L4-L5 TOS, and L4-L5 BLIF, respectively. Displacement and rotation of the anterior S1 foramen at 30° and 40° sacral slope (SS) were analyzed. RESULTS: The displacement of L4-L5/L5 TOS in the left-right and vertical direction, total displacement, and rotation in lateral bending decreased significantly, which is more pronounced at 40° SS. The difference in stability between L4-L5 and L5 ULIF was not significant. BLIF significantly limited left-right displacement. The ULIF vertical displacement at 40° SS was significantly higher than that at 30° SS. CONCLUSIONS: This study developed an in vitro two-legged standing pelvic model and demonstrated that TOS enhanced pelvic stability in the coronal plane and cephalad-caudal direction, and BLIF enhanced stability in the left-right direction. L4-L5 ULIF did not further improve the immediate stability, whereas TOS is required to increase the vertical stability at greater SS.
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Cadáver , Fijación Interna de Fracturas , Fracturas Óseas , Vértebras Lumbares , Huesos Pélvicos , Sacro , Humanos , Masculino , Huesos Pélvicos/lesiones , Fenómenos Biomecánicos , Sacro/lesiones , Sacro/cirugía , Vértebras Lumbares/lesiones , Vértebras Lumbares/cirugía , Vértebras Lumbares/fisiopatología , Fracturas Óseas/cirugía , Fijación Interna de Fracturas/métodos , Ilion , Persona de Mediana Edad , AncianoRESUMEN
The present study investigated the growth performance, feed utilization, intestinal morphology, and microbiota communities of juvenile large yellow croaker (Larimichthys crocea) fed diets containing different proportions of soy protein concentrate (SPC) (0, 15%, 30%, and 45%, namely FM, SPC15, SPC30, and SPC45) as a substitute for fish meal (FM) for 8 weeks. The weight gain (WG) and specific growth rate (SGR) in fish fed SPC45 were significantly lower than those fed FM and SPC15 but not differ with these fed SPC30. The feed efficiency (FE) and protein efficiency ratio (PER) decreased sharply when the dietary SPC inclusion level was higher than 15%. The activity of alanine aminotransferase (ALT) and expression of alt and aspartate aminotransferase (ast) were significantly higher in fish fed SPC45 than those fed FM. The activity and mRNA expression of acid phosphatase were opposite. The villi height (VH) in distal intestine (DI) showed a significant quadratic response to increasing dietary SPC inclusion levels and was highest in SPC15. The VH in proximal intestine, middle intestine decreased significantly with increasing dietary SPC levels. The 16S rRNA sequences in intestine revealed that fish fed SPC15 had higher bacterial diversity and abundance of Phylum Firmicutes such as order Lactobacillales and order Rhizobiaceae than those fed other diets. Genus vibrio, family Vibrionaceae and order Vibrionales within phylum Proteobacteria were enriched in fish fed FM and SPC30 diets. Tyzzerella and Shewanella that belongs to phylum Firmicutes and Proteobacteria, respectively, were enriched in fish fed SPC45 diet. Our results indicated that SPC replacing more than 30% FM could lead to lower quality diet, retard growth performance, ill health, disordered intestine structure, and microbiota communities. Tyzzerella could be the bacteria indicator of intestinal in large yellow croaker fed low quality diet due to high SPC content. Based on the quadratic regression analysis of WG, the best growth performance could be observed when the replacement of FM with SPC was 9.75%.
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Although fish steak meal (FSM) is a potentially available protein source, its efficiency as a fish meal (FM) substitute remains unclear to date. To this end, this study was carried out to determine the effects of dietary FM replaced by FSM on growth performance, antioxidant capacity, intestinal health and microflora, inflammatory response, and protein metabolism of large yellow croaker. Five isolipidic and isonitrogenous diets were formulated by substituting FM with FSM at levels of 0% (FSM0, control diet), 25% (FSM25), 50% (FSM50), 75% (FSM75), and 100% (FSM100), and were fed to juvenile large yellow croaker for 8 weeks. Compared with the control diet, the replacement of 25% dietary FM with FSM did not markedly alter the weight gain (WG) and specific growth rate (SGR). When the FM substitution level was over 25%, WG and SGR markedly reduced. The intestinal structure observation found that the FSM75 and FSM100 diets markedly decreased villus height, villus width, and muscle thickness of the anterior intestine. The FSM75 and FSM100 diets significantly decreased enzyme activities of amylase (AMS), lipase (LPS), trypsin, catalase (CAT), and total superoxide dismutase (T-SOD) and the total antioxidant capacity (T-AOC), and increased the malondialdehyde (MDA) content in the liver of large yellow croaker. The mRNA expression levels of intestinal barrier and inflammatory response-related genes suggested that the FSM50, FSM75, and FSM100 diets significantly decreased the mRNA abundances of intestinal barrier-related genes and anti-inflammatory response-related genes, and increased the mRNA abundances of proinflammatory gene il-6 in the anterior intestine. The compositions of intestinal microflora displayed that the FSM50, FSM75, and FSM100 diets decreased relative abundances of Firmicutes phylum and increased relative abundances of Proteobacteria phylum. In addition, the results of protein expression levels showed that the phosphorylation level of mammalian target of rapamycin (mTOR) and 4E-binding protein 1 (4E-BP1) in FSM75 and FSM100 groups were markedly reduced. In conclusion, FSM can replace up to 25% dietary FM without compromising the growth performance, intestinal health, and protein metabolism of the large yellow croaker.
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Laryngeal squamous cell carcinoma (LSCC) is a common form of head and neck cancer with poor prognosis. However, the mechanism underlying the pathogenesis of LSCC remains unclear. Here, we demonstrated increased expression of fascin actin-bundling protein 1 (FSCN1) and decreased expression of microRNA-145-5p (miR-145-5p) in a clinical cohort of LSCC. Luciferase assay revealed that miR-145-5p is a negative regulator of FSCN1. Importantly, low miR-145-5p expression was correlated with TNM (tumor, node, metastasis) status and metastasis. Moreover, cases with low miR-145-5p/high FSCN1 expression showed poor prognosis, and these characteristics together served as independent prognostic indicators of survival. Gain- and loss-of-function studies showed that miR-145-5p overexpression or FSCN1 knockdown inhibited LSCC migration, invasion, and growth by suppressing the epithelial-mesenchymal transition along with inducing cell-cycle arrest and apoptosis. Additionally, hypermethylation of the miR-145-5p promoter suggested that repression of miR-145-5p arises through epigenetic inactivation. LSCC tumor growth in vivo could be inhibited by using miR-145-5p agomir or FSCN1 small interfering RNA (siRNA), which highlights the potential for clinical translation. Collectively, our findings indicate that miR-145-5p plays critical roles in inhibiting the progression of LSCC by suppressing FSCN1. Both miR-145-5p and FSCN1 are important potential prognostic markers and therapeutic targets for LSCC.
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Proteínas Portadoras/metabolismo , Metilación de ADN/fisiología , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/metabolismo , MicroARNs/genética , Proteínas de Microfilamentos/metabolismo , Regiones Promotoras Genéticas/genética , Animales , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Proteínas Portadoras/genética , Línea Celular , Línea Celular Tumoral , Metilación de ADN/genética , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/fisiología , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , MicroARNs/fisiología , Proteínas de Microfilamentos/genéticaRESUMEN
In order to visually display the migration and crystallization process of salt solution in porous cultural relics, copper sulfate solution with color rendering property was selected to record the migration, crystallization and resolution of salt solution in simulated SiO2 samples under different environmental conditions in real time through high-resolution recording system, scanning electron microscope system, salt phase X-ray diffraction system, and so on. The results showed the migration of salt solution in porous samples was related to the structural characteristics of the porous samples, the migration rate of salt solution, the evaporation rate and the change frequency of crystallization-resolution, etc., in which the large pore size of the sample, the higher the concentration and the faster migration and evaporation rate of salt solution, the greater the change rate of the brine accumulation zone or salt crystallization zone in the different porous samples. During the humidification-drying cycles of rainfall, the higher the cycle frequency of humidification-drying was, the higher the drying temperature was, the more frequent the crystallization-analysis change of salt in the salt-bearing sample was, and the more extensive the distribution of salt crystal zone was. This is the first time to visualize the salt belt by simulating the changing process of a salt solution with a color rendering property in porous samples. This has scientific theoretical guidance for the study of the migration-crystallization changes of soluble salts contained in porous silicate cultural relics. The visibility analysis results of multilayer salt crystal belts can also provide the preliminary basis for further effective desalination of salt bearing cultural relics.
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Cuarzo/química , Cloruro de Sodio/química , Rastreo Diferencial de Calorimetría/métodos , Cristalización/métodos , Porosidad , Sales (Química)/química , Dióxido de Silicio/química , Solubilidad , Soluciones/química , Temperatura , Difracción de Rayos X/métodosRESUMEN
It is easy for chemical pigments produced from organic chemicals to disappear when exposed to light over time. Recently, structurally colored pigments produced by materials with high indices of refraction such as TiO2 or ZnS have attracted great attention. This study presents that CdS@SiO2 core-shell nanospheres were synthesized through a homogeneous deposition method followed with a modified Stöber method and a calcination process. Colored film assembled by pigments shows low angle dependence with high stability against degradation under environmental factors. Moreover, the structural color of CdS@SiO2 arrays was bright and tunable according to the size without changing the overall material design. Compared with the conventional method, the addition of black substances in colloidal spheres is the generally used method to realize angle-independent structural coloration. However, black materials (such as carbon blacks and acetylene black) are not stable because of the high surface energy, and usually reunite together easily, and then lead to a nonuniform distribution and significant decrease in brightness. Thus, we report self-assembly colored films with great low angle dependence but not any black substances. Moreover, the refractive index of CdS is higher than generally used PS, PMMA, and SiO2, and the SiO2 shell is poisonless. CdS@SiO2 structurally colored films have promising nonbleaching pigments and have potential applications for displays, colorimetric sensors, colorful decoration, and pigments.
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BACKGROUND/AIMS: CD133+CD44+ cancer stem cells previously isolated from laryngeal squamous cell carcinoma (LSCC) cell lines showed strong malignancy and tumorigenicity. However, the molecular mechanism underlying the enhanced malignancy remained unclear. METHODS: Cell proliferation assay, spheroid-formation experiment, RNA sequencing (RNA-seq), miRNA-seq, bioinformatic analysis, quantitative real-time PCR, migration assay, invasion assay, and luciferase reporter assay were used to identify differentially expressed mRNAs, lncRNAs, circRNAs and miRNAs, construct transcription regulatory network, and investigate functional roles and mechanism of circRNA in CD133+CD44+ laryngeal cancer stem cells. RESULTS: Differentially expressed genes in TDP cells were mainly enriched in the biological processes of cell differentiation, regulation of autophagy, negative regulation of cell death, regulation of cell growth, response to hypoxia, telomere maintenance, cellular response to gamma radiation, and regulation of apoptotic signaling, which are closely related to the malignant features of tumor cells. We constructed the regulatory network of differentially expressed circRNAs, miRNAs and mRNAs. qPCR findings for the expression of key genes in the network were consistent with the sequencing data. Moreover, our data revealed that circRNA hg19_circ_0005033 promotes proliferation, migration, invasion, and chemotherapy resistance of laryngeal cancer stem cells. CONCLUSIONS: This study provides potential biomarkers and targets for LSCC diagnosis and therapy, and provide important evidences for the heterogeneity of LSCC cells at the transcription level.
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Antígeno AC133/metabolismo , Antígenos CD/metabolismo , Biomarcadores de Tumor/metabolismo , Cadherinas/metabolismo , Carcinoma de Células Escamosas/metabolismo , Perfilación de la Expresión Génica , Neoplasias Laríngeas/metabolismo , Proteínas de Neoplasias/metabolismo , Células Madre Neoplásicas/metabolismo , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Humanos , Células Madre Neoplásicas/patologíaRESUMEN
As intercalation-type anode materials for Li-ion batteries (LIBs), the commercially used graphite and Li4 Ti5 O12 exhibit good cycling and rate properties, but their theoretical specific capacities are too low to meet the ever-growing demands of high-energy applications such as electric vehicles. Therefore, the development of new intercalation-type anode materials with larger capacity is very desirable. Herein, we design and synthesize novel 3 D hierarchical porous V2 O3 @C micro/nanostructures consisting of crumpled nanosheets, through self-reduction under annealing from the structurally similar VO2 (B)@C precursors without the addition of any other reducing reagent or gas. Excitingly, it is found for the first time through exâ situ XRD technology that V2 O3 is a new, promising intercalation-type anode material for LIBs with a high capacity. V2 O3 @C micro/nanostructures can deliver a large capacity of 732â mAh g-1 without capacity loss at 100â mA g-1 even after 136 cycles, as well as exhibiting excellent cycling and rate performances. The application of V2 O3 for Na-ion batteries (NIBs) is elaborated for the first time, and excitingly, it is found that V2 O3 @C micro/nanostructures may be promising anode materials for NIBs.
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This study aimed to investigate the phenomenon of mitochondrial apoptosis and autophagy in the process of adipose-derived stromal cell (ADSC) differentiation into astrocytes for 48 h, 7 days, 14 days, and 21 days. Immunocytochemistry and Western blotting indicated that the expression of GFAP reached a peak on the 7th day (P < 0.05). The expression of Bcl-2 was decreased (P < 0.05), but Bax, Cyt-c, and LC3 increased with time and reached a maximum on the 14th day (P < 0.05). TEM was used to observe the ultrastructure of mitochondria, apoptosis, and autophagy. An MTT assay indicated that the number of surviving cells decreased. During ADSC differentiation into astrocytes, the effect of Bcl-2 inhibition on apoptosis decreased, whereas mitochondrial apoptosis and autophagy were enhanced; however, this selective autophagy could not eliminate all the damaged mitochondria, leading to mitochondrial apoptosis.
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Tejido Adiposo/citología , Astrocitos/citología , Mitocondrias/fisiología , Células del Estroma/citología , Tejido Adiposo/metabolismo , Adulto , Apoptosis/fisiología , Proteínas Reguladoras de la Apoptosis/metabolismo , Astrocitos/metabolismo , Autofagia/fisiología , Diferenciación Celular/fisiología , Supervivencia Celular/fisiología , Células Cultivadas , Humanos , Proteínas de la Membrana/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Mitocondrias/metabolismo , Células del Estroma/metabolismoRESUMEN
Monoclinic VO2 (M) is a key material for energy-efficient smart window applications. Fine crystalline VO2 particles with an ambient phase transition temperature are urgently required to achieve excellent properties including high luminous transmittance and solar heat shielding ability. Moreover, the anti-oxidation ability is regarded as a significant factor which determines the lifetime of VO2-based products. In this paper, well-crystallized W-doped VO2 with low phase transition temperature, excellent solar heat shielding ability and considerable anti-oxidation ability was synthesized by a solid-state reaction process. The phase transition temperature was reduced from 67.3 °C to 10.8 °C at 2.0% W doping with an efficiency of -28.1 °C per at%. Importantly, an excellent balance between the phase transition temperature and the latent heat was obtained at high doping levels (1.5-2.0%). Furthermore, W-doped VO2 particles exhibited a significantly longer exposure time (more than 5 h) at 300 °C in air than the previously reported 2 h in the literature, and the corresponding derived composite foils showed excellent luminous transmittance and solar heat shielding properties (Tlum = 49.9% and Tsol = 44.8% for 2.0% W doping).
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VO2 is a promising thermochromic material that can intelligently control the transmittance of sunlight in the near-infrared region in response to temperature change, although the high phase transition temperature (Tc) of 340 K restricts its wide application. Our first-principles calculations show that hydrogen is an efficient dopant which can stabilize the metallic VO2 phase at ambient temperature through reducing Tc by 38 K/at% H. The reduction in Tc is coupled with the changes in atomic and electronic structures, i.e., the V-V chains feature the dimerization characteristics in H-doped VO2(R) and the V-O bonds become less ionic due to the formation of a typical H-O covalent bond. In addition, hydrogen-doped VO2 is more sensitive to external strain as compared with pure VO2, implying that Tc can be further regulated through a combination of H-doping and strain.
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Converting low-grade thermal energy into electrical energy is crucial for the development of modern smart wearable energy technologies. The free-standing films of PEDOT@Bi2Te3 prepared by tape-casting hold promise for flexible thermoelectric technology in self-powered sensing applications. Bi2Te3 nanosheets fabricated by the solvothermal method are tightly connected with flat-arranged PEODT molecules, forming an S-Bi bonded interface in the composite materials, and the bandgap is reduced to 1.63 eV. Compared with the PEDOT film, the mobility and carrier concentration of the composite are significantly increased at room temperature, and the conductivity reaches 684 S/cm. Meanwhile, the carrier concentration decreased sharply at 360 K indicating the creation of defect energy levels during the interfacial reaction of the composites, which increased the Seebeck coefficient. The power factor was improved by 68.9% compared to PEDOT. In addition, the introduction of Bi2Te3 nanosheets generated defects and multidimensional interfaces in the composite film, which resulted in weak phonon scattering in the conducting polymer with interfacial scattering. The thermal conductivity of the film is decreased and the ZT value reaches 0.1. The composite film undergoes 1500 bending cycles with a 14% decrease in conductivity and has good flexibility. This self-supporting flexible thermoelectric composite film has provided a research basis for low-grade thermal energy applications.
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Apoptosis is the primary cause of cell death in the differentiation of Adipose-derived stromal cells (ADSCs) into neurons. However, the relationship between endoplasmic reticulum stress (ERS) and death receptor-mediated apoptosis in ADSC-induced neuronal differentiation is not clear. ADSCs were isolated and induced to differentiate into neurons using ß-mercaptoethanol. The expression of neuron-specific enolase (NSE), GRP94, CHOP, Fas/FasL, TNFR1/TNF-α, DR5/TRAIL, Caspase8, and Caspase3 in ADSCs was examined using immunocytochemistry and Western blotting before induction, during pre-induction, and after induction. Transmission electron microscopy (TEM) was used to observe changes in the morphology of the endoplasmic reticulum (ER), and the MTT assay was employed to measure cell viability in the uninduced and induced groups. Additionally, the number of apoptotic cells during the induction process was measured using flow cytometry with Annexin V/PI. With increasing induction time, the positive expression rates of CHOP, Fas/FasL, Caspase8, Caspase-3, and NSE gradually increased, while the positive expression rate of GRP94 decreased. TNFR1/TNF-α and DR5/TRAIL peaked at 5 h post-induction and then decreased at 8 h. TEM revealed swelling and expansion of the ER, vacuolar changes, and degranulation in cells. The MTT assay showed a gradual decrease in the absorbance of surviving cells in all groups. Flow cytometry indicated an increasing rate of apoptosis in cells. Therefore, ERS in the normal culture and growth of ADSCs, manifesting as enhanced unfolded protein response (UPR), maintains the normal survival of ADSCs. However, in the process of ADSC-induced differentiation into neurons, ERS and death receptor-mediated apoptosis are significant causes of cell death.
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Sonophotodynamic antimicrobial therapy (SPDAT) is recognized as a highly efficient biomedical treatment option, known for its versatility and remarkable healing outcomes. Nevertheless, there is a scarcity of sonophotosensitizers that demonstrate both low cytotoxicity and exceptional antibacterial effectiveness in clinical applications. In this paper, a novel ZnO nanowires (NWs)@TiO2-xNy core-sheath composite was developed, which integrates the piezoelectric effect and heterojunction to build dual built-in electric fields. Remarkably, it showed superb antibacterial effectiveness (achieving 95% within 60 min against S. aureus and â¼100% within 40 min against E. coli, respectively) when exposed to visible light and ultrasound. Due to the continuous interference caused by light and ultrasound, the material's electrostatic equilibrium gets disrupted. The modification in electrical properties facilitates the composite's ability to attract bacterial cells through electrostatic forces. Moreover, Zn-O-Ti and Zn-N-Ti bonds formed at the interface of ZnO NWs@TiO2-xNy, further enhancing the dual internal electric fields to accelerate the excited carrier separation to generate more reactive oxygen species (ROS), and thereby boosting the antimicrobial performance. In addition, the TiO2 layer limited Zn2+ dissolution into solution, leading to good biocompatibility and low cytotoxicity. Lastly, we suggest a mechanistic model to offer practical direction for the future development of antibacterial agents that are both low in toxicity and high in efficacy. In comparison to the traditional photodynamic therapy systems, ZnO NWs@TiO2-xNy composites exhibit super piezo-photocatalytic antibacterial activity with low toxicity, which shows great potential for clinical application as an antibacterial nanomaterial.
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Antibacterianos , Escherichia coli , Nanocables , Staphylococcus aureus , Titanio , Óxido de Zinc , Titanio/química , Titanio/farmacología , Titanio/efectos de la radiación , Óxido de Zinc/química , Óxido de Zinc/farmacología , Antibacterianos/química , Antibacterianos/farmacología , Escherichia coli/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Nanocables/química , Catálisis , Especies Reactivas de Oxígeno/metabolismo , Pruebas de Sensibilidad Microbiana , Humanos , Luz , Ratones , AnimalesRESUMEN
This communication first achieved piezo-photocatalytic reduction of nitrates to N2 through designing an Ag2O/BaTiO3@TiO2 core-shell catalyst. The built-in electric field induced by piezoelectric polarization suppresses photoexcited carrier recombination, and simultaneously causes energy band tilting, leading to the generation of electrons with higher reducibility to directly trigger the NO3- reduction to ËNO32-, even without hole scavengers.
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This paper reports the successful preparation of Mg-doped VO2 nanoparticles via hydrothermal synthesis. The metal-insulator transition temperature (T(c)) decreased by approximately 2 K per at% Mg. The Tc decreased to 54 °C with 7.0 at% dopant. The composite foils made from Mg-doped VO2 particles displayed excellent visible transmittance (up to 54.2%) and solar modulation ability (up to 10.6%). In addition, the absorption edge blue-shifted from 490 nm to 440 nm at a Mg content of 3.8 at%, representing a widened optical band gap from 2.0 eV for pure VO2 to 2.4 eV at 3.8 at% doping. As a result, the colour of the Mg-doped films was modified to increase their brightness and lighten the yellow colour over that of the undoped-VO2 film. A first principle calculation was conducted to understand how dopants affect the optical, Mott phase transition and structural properties of VO2.
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F-doped VO2 (M1) nanoparticles were prepared via one-pot hydrothermal synthesis. The F-doping can minimise the size of the VO2 (M1) nanoparticles, induce a homogeneous size distribution and effectively decrease the phase transition temperature to 35 °C at 2.93% F in VO2. VO2 smart glass foils obtained by casting these nanoparticles exhibit excellent thermochromism in the near-infrared region, which suggests that these foils can be used for energy-efficient glass. Compared to a pure VO2 foil, the 2.93% F-doped VO2 foil exhibits an increased solar-heat shielding ability (35.1%) and a modified comfortable colour, while still retaining an excellent solar modulation ability (10.7%) and an appropriate visible transmittance (48.7%). The F-doped VO2 foils are the first to simultaneously meet the requirements of a reduced phase transition temperature, diluted colour and excellent thermochromic properties, and these properties make the further improved F-doped VO2 foils suitable for commercial applications in energy efficient glass.
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The Mott phase transition compound vanadium dioxide (VO2) shows promise as a thermochromic smart material for the improvement of energy efficiency and comfort in a number of applications. However, the use of VO2 has been restricted by its low visible transmittance (Tvis) and limited solar modulation ability (ΔTsol). Many efforts have been made to improve both of these limitations, but progress towards the optimization of one aspect has always come at the expense of the other. This paper reports that Ti doping results in the improvement of both the Tvis and ΔTsol of VO2-nanoparticle-derived flexible foils to the best levels yet reported. Compared with an undoped VO2 foil, a 15% increase (from 46.1% to 53%) in Tvis and a 28% increase (from 13.4% to 17.2%) in ΔTsol are achieved at a Ti doping level of 1.1%, representing the best performance reported for similar foils or films prepared using various methods. Only a defined doping level of less than 3% is beneficial for simultaneous improvement in Tvis and ΔTsol. First principle calculations suggest that an increase in the intrinsic band gap of VO2 (M) and the reduced electron density at Fermi level of VO2 (R) cooperate to result in the improvement of ΔTsol and that an enhancement in the optical band gap of VO2 (M) leads to the increase of Tvis.
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The wooden sluice site of the Nanyue Kingdom in Guangzhou, China, is covered with white magnesium sulfate salt whiskers continuously growing from the surface. In this paper, polarizing microscopy, scanning electron microscopy, infrared thermography, Fourier transform infrared spectrometry, and surface tension analysis were utilized to comprehensively analyze the micromorphology of whiskers grown on the surfaces of porous materials collected at the site of Nanyue Kingdom, as well as the change laws of magnesium sulfate solution droplets on the porous hydrophilic matrix, and the migration and crystallization of magnesium sulfate solution in the capillary tube. The diameters of magnesium sulfate salt whiskers grown on the surfaces of porous samples range from 30 to 110 µm. For the first time, it is clear to see that the whisker's structure is hollow and nodular. There are solid crystalline salts in hollow tubes, and some of them are aqueous. The top sections of whiskers are approximately circular and are composed of particles with a size of about 0.4-4.0 µm. Their growth conditions are mainly characterized by the high humidity environment where the porous material is located or locally located, the formation of an annular whisker base, and the pressure difference generated during the formation progress of water-bearing crystals in the capillary of the whisker. The research results expound on the circumstances and mechanism of magnesium sulfate solution-induced whisker development on the surface of porous materials, providing a reference for the study of the whisker growth mechanism.