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1.
Curr Eye Res ; : 1-9, 2024 Oct 02.
Article in English | MEDLINE | ID: mdl-39356002

ABSTRACT

PURPOSE: Bufalin (BU) is a bioactive ingredient extracted from the skin and parotid venom glands of Bufo raddei, which can effectively inhibit angiogenesis. The aim of this study was to investigate whether BU could affect corneal neovascularization (CoNV). METHODS: A rat CoNV model (right eye) was constructed by administration of NaOH, and the left eye served as a control. Corneal damage scores of rats were detected. Hematoxylin & eosin, TUNEL, and Masson staining examined pathological changes, apoptosis, and fibrosis of corneal tissues. Immunohistochemistry and western blotting assessed the expression of proteins. RESULTS: BU intervention resulted in a significant reduction in corneal inflammatory cells, repair of corneal epithelial hyperplasia, significant reduction in stromal edema, and reduction in vascular proliferation. BU can inhibit corneal neovascularization. CONCLUSION: This study demonstrated that BU inhibits CoNV, fibrosis, and inflammation by modulating the STAT3 signaling pathway, elucidating the intrinsic mechanism of its protective effect. BU has great potential in the treatment of CoNV caused by corneal alkali burns.

2.
Antibiotics (Basel) ; 13(3)2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38534651

ABSTRACT

In recent years, traditional antibiotic efficacy outcomes have rapidly diminished due to the advent of drug resistance, and the dose limitation value has increased due to the severe side effect of globalized healthcare. Therefore, novel strategies are required to resensitize resistant pathogens to antibiotics existing in the field and prevent the emergence of drug resistance. In this study, cationic hyperbranched polylysine (HBPL-6) was synthesized using the one-pot polymerization method. HBPL-6 exhibited excellent non-cytotoxicity and bio-solubility properties. The present study also showed that HBPL-6 altered the outer membrane (OM) integrity of Escherichia coli O157:H7, Salmonella typhimurium, and Pseudomonas aeruginosa PAO1 by improving their permeability levels. When administered at a safe dosage, HBPL-6 enhanced the accumulation of rifampicin (RIF) and erythromycin (ERY) in bacteria to restore the efficacy of the antibiotics used. Moreover, the combination of HBPL-6 with colistin (COL) reduced the antibiotic dosage, which was helpful in preventing further drug-resistance outcomes. Therefore, this research provides a new strategy for reducing the dosage of drugs used to combat Gram-negative (G-) bacteria through their synergistic effects.

3.
Langmuir ; 39(49): 17611-17621, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38015618

ABSTRACT

A waterborne polyurethane pressure-sensitive adhesive (WPUPSA) has the advantages of low pollution and good viscoelasticity. However, its poor thermo-tolerance limits its application in the field of high temperatures. Hence, a novel silicone-modified strong thermo-tolerant waterborne polyurethane/polyimide pressure-sensitive adhesive is developed as a way to remedy this problem. The single-chain structure of waterborne polyurethane (WPU) is transformed into a network structure by introducing the three-position network structure to increase the cohesive energy and heat resistance of the WPUPSA. Meanwhile, the primary chain of waterborne polyurethane (WPU) is modified by the reaction between pyromellitic dianhydride (PMDA) and isophorone diisocyanate (IPDI) to include an imide ring and a benzene ring with more stable structures and heat resistance. Characterization results of the prepared WPUPSA show that the thermo-tolerance index of the WPUPSA increases by 15.2% and the room temperature 180° peel strength and shear resistance of the WPUPSA increase by 80.9 and 231.8%, respectively. Meanwhile, the temperature corresponding to the maximum thermal decomposition rate of the samples is improved. More importantly, at 80 and 100 °C, the 180° peel strength and shear resistance of the modified samples are stronger than those of the unmodified samples. In addition, the energy storage modulus of WPUPSAs is also greater than the loss and increases with the increase of the frequency. Viscoelasticity dominates in the samples. This will provide new insight for the development of WPUPSAs in the field of high-temperature resistance.

4.
Clin Cosmet Investig Dermatol ; 16: 2329-2331, 2023.
Article in English | MEDLINE | ID: mdl-37663887

ABSTRACT

Cutaneous pili migrans is a rare condition caused by embedded hair shafts or fragments which presents as a mobile black linear rash and is easily confused with cutaneous larva migrans. "Ingrowing hair", in which the hair shaft grows inside the skin and burrows into the uppermost dermis rather than exiting the skin, is much rarer, and only 8 cases have been reported thus far, all in Asian men. We report a case of a 22-year-old Chinese male with a 4 cm-long black linear rash that migrated from the anterior abdomen to the left lower abdomen. The black lines represented hair shafts with follicular structures. The lesion disappeared immediately after hair removal. No recurrence occurred in 4 weeks of follow-up. To our knowledge, this is the first description of ingrowing hair occurring in the abdomen.

5.
Antioxidants (Basel) ; 12(8)2023 Aug 08.
Article in English | MEDLINE | ID: mdl-37627574

ABSTRACT

In this study, D-mannose was used to synthesize poly-D-mannose using a one-pot method. The molecular weight, degree of branching, monosaccharide composition, total sugar content, and infrared spectrum were determined. In addition, we evaluated the safety and bioactivity of poly-D-mannose including anti-pathogen biofilm, antioxidant, and anti-inflammatory activity. The results showed that poly-D-mannose was a mixture of four components with different molecular weights. The molecular weight of the first three components was larger than 410,000 Da, and that of the fourth was 3884 Da. The branching degree of poly-D-mannose was 0.53. The total sugar content was 97.70%, and the monosaccharide was composed only of mannose. The infrared spectra showed that poly-D-mannose possessed characteristic groups of polysaccharides. Poly-D-mannose showed no cytotoxicity or hemolytic activity at the concentration range from 0.125 mg/mL to 8 mg/mL. In addition, poly-D-mannose had the best inhibition effect on Salmonella typhimurium at the concentration of 2 mg/mL (68.0% ± 3.9%). The inhibition effect on Escherichia coli O157:H7 was not obvious, and the biofilm was reduced by 37.6% ± 2.9% at 2 mg/mL. For Staphylococcus aureus and Bacillus cereus, poly-D-mannose had no effect on biofilms at low concentration; however, 2 mg/mL of poly-D-mannose showed inhibition rates of 33.7% ± 6.4% and 47.5% ± 4%, respectively. Poly-D-mannose showed different scavenging ability on free radicals. It showed the best scavenging effect on DPPH, with the highest scavenging rate of 74.0% ± 2.8%, followed by hydroxyl radicals, with the scavenging rate of 36.5% ± 1.6%; the scavenging rates of superoxide anion radicals and ABTS radicals were the lowest, at only 10.1% ± 2.1% and 16.3% ± 0.9%, respectively. In lipopolysaccharide (LPS)-stimulated macrophages, poly-D-mannose decreased the secretion of nitric oxide (NO) and reactive oxygen species (ROS), and down-regulated the expression of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Therefore, it can be concluded that poly-D-mannose prepared in this research is safe and has certain biological activity. Meanwhile, it provides a new idea for the development of novel prebiotics for food and feed industries or active ingredients used for pharmaceutical production in the future.

6.
Molecules ; 28(13)2023 Jul 04.
Article in English | MEDLINE | ID: mdl-37446859

ABSTRACT

In this study, ZnAl-layered double hydroxide (ZnAl-LDH) was functionalized with 2-phenylbenzimidazole-5-sulfonic acid (PBSA) to prepare ZnAl-PBSA-LDH using a simple one-step method. The electrochemical impedance spectroscopy (EIS) result of the solution phase demonstrated excellent corrosion inhibition performance of ZnAl-PBSA-LDH. Subsequently, 0.6 wt.% ZnAl-PBSA-LDH with shielding effects and active inhibition was incorporated into the water-based epoxy (WEP) for preparing the high-performance anti-corrosion coating (6-ZPL/WEP). The EIS test illustrated that the 6-ZPL/WEP coating maintained a high low-frequency impedance modulus (|Z0.01 Hz|) after 30 days of immersion, which is nearly two orders of magnitude higher compared to that of the blank coating. These results demonstrated that ZnAl-PBSA-LDH could efficiently improve the corrosion resistance of the WEP coating. Therefore, this study introduces new insights into the use of layered double hydroxides (LDHs) in the domain of anti-corrosion.


Subject(s)
Hydroxides , Water , Hydroxides/chemistry , Corrosion
7.
Front Surg ; 10: 1079337, 2023.
Article in English | MEDLINE | ID: mdl-37273824

ABSTRACT

Purpose: To investigate the attitudes among cardiac surgery ICU patients and their families regarding life-sustaining treatment. Methods: A total of 172 pairs of patients in the cardiac surgery ICU of Nanjing First Hospital and their family members were enrolled in this study that examined their attitudes toward life-sustaining treatment using a willingness to care for life-sustaining treatment questionnaire. The consistency of the attitudes of patients and family members toward life-sustaining treatment was analyzed by the chi-square test with a paired design. Results: The most popular life-sustaining treatment for cardiac ICU patients was noninvasive mechanical ventilation (79.1%); the most unpopular was intra-aortic balloon counterpulsation (48.3%). Most patients and their families had not considered electric defibrillation (65.7%), but most understood and were willing to permit cardiopulmonary resuscitation (76.2%). Few family members agreed that patients should receive a pacemaker (25.0%). The consistency of life support attitudes of patients and their families ranged from 12.8% to 60.5% for procedures both would agree to, 1.2% to 19.8% for procedures they were unwilling to permit, and 0.6% to 39.0% for procedures they had not considered. Kappa values ranged from 0.218 to 0.597 (P < 0.05), with general consistency. Conclusion: Cardiac surgery ICU patients families are generally consistent in their attitudes toward life-sustaining treatment, and family members' choices are not representative of patients' wishes.

8.
Chem Res Chin Univ ; 39(2): 266-275, 2023.
Article in English | MEDLINE | ID: mdl-35966397

ABSTRACT

Cationic water-based polyurethane(CWPU) was synthesized to explore aloe-emodin modifies to obtain CWPU materials with better comprehensive performance. It provides a simple way to synthesize antibacterial waterborne polyurethane, which is to introduce the end-blocking group of herbal extracts into the structure. It contains synergistic antibacterial effect of herbal antibacterial and quaternary ammonium ion on Escherichia coli. It makes the material resist the erosion of bacterial, and increase the service life of materials. When the pH value of the environment changes, the UV absorbance of the aloe-emodin modified cationic water-based polyurethane(AE-CWPU) also changes. Therefore, within a certain detection range, AE-CWPU has great applications in the field of smart response materials. The modified thermodynamic properties have been improved, and the mechanical properties basically maintained the maximum stress, and the elongation at break was reduced.

9.
ISA Trans ; 131: 566-578, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35597608

ABSTRACT

In the single-excitation-motor inertial flip-flow screen, the vibration phase difference is difficult to maintain at the ideal angle of 180° for two screen frames, which results in the low screening efficiency. To solve this problem, a flip-flow screen driven by double excitation motors is established, together with its control system. The vibration phase difference for two screen frames can reach 180° when the phase difference for two eccentric blocks is 170° based on the experimental model. Therefore, the speed synchronization based on cross-coupling and improved point-based Bang-Bang phase compensation control strategies are proposed and dSPACE is used to build the control platform. Experimental results achieved have been confirmed the control effectiveness during screening process.


Subject(s)
Models, Theoretical , Vibration
10.
Macromol Rapid Commun ; 42(22): e2100457, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34647394

ABSTRACT

In the past two decades, ionic conductive hydrogel has attracted tremendous research interests for their intrinsic characteristics in the field of flexible sensor. However, synchronous achievement of high mechanical strength, satisfied ionic conductivity, and broad adhesion to various substrates is still a challenge. Herein, a novel zwitterionic composite hydrogel that displayed excited strechability (up to 900%), satisfied strength (about 30 kPa), high ionic conductivity (1.2 mS cm-1 ), and adhesion to polar and nonpolar materials is fabricated though the combination of waterborne polyurethanes (PU) and poly(sulfobetaine zwitterion-co-acrylamide) (SAm). Especially, this facile strategy demonstrates that PU has a synergistic effect on enhancing mechanical strength and ionic conductivity for ionic conductive hydrogel. Moreover, the hydrogel-based strain/stress sensor shows high sensitivity, wide sensing range, great stability, and accuracy for human body movements detecting and voice recognition. This novel ionic conductive hydrogel has promoted the development of wearable devices.


Subject(s)
Hydrogels , Wearable Electronic Devices , Adhesives , Electric Conductivity , Humans , Polyurethanes
11.
Oxid Med Cell Longev ; 2021: 8814163, 2021.
Article in English | MEDLINE | ID: mdl-34257820

ABSTRACT

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. The association between epithelial-mesenchymal transition (EMT) and fibrosis is quite ascertained, but its link to eventual tubule dysfunction is missing. Here, we show that human microRNA- (hsa-miR-) 199b-3p protects renal tubules from diabetic-induced injury by repressing KDM6A, a histone lysine demethylase regulating E-cadherin expression. Lower E-cadherin expression is related to a higher level of KDM6A, while E-cadherin is promoted upon treatment with the KDM6A inhibitor GSK-J4 in both high glucose- (HG-) induced HK2 cells and the kidneys from streptozotocin- (STZ-) induced type 1 diabetic mice. However, overexpression or RNA silencing of E-cadherin fails to alter KDM6A expression. We also show that the upregulation of KDM6A is associated with the increased methylation level of the E-cadherin promoter. Then, the target prediction results and a dual-luciferase assay show that hsa-miR-199b-3p is a new miRNA that targets KDM6A. Overexpression of hsa-miR-199b-3p increases E-cadherin expression and prevents EMT through repressing KDM6A expression in HG-induced HK2 cells. In contrast, inhibitor-induced hsa-miR-199b-3p knockdown has opposite effects, as it decreases E-cadherin level and worsens EMT, accompanied by increased levels of KDM6A. Besides, Mir199b-knockout mice without mmu-miR-119b-3p expression exhibit more renal tubule dysfunction and more serious kidney tissue damage upon treatment with STZ. These results demonstrate that hsa-miR-199b-3p improves E-cadherin expression and prevents the progression of DN through targeting KDM6A. miR-199b-3p could be a future biomarker or target for the diagnosis or treatment of DN.


Subject(s)
Antigens, CD/metabolism , Cadherins/metabolism , Diabetic Nephropathies/metabolism , Histone Demethylases/metabolism , MicroRNAs/metabolism , Animals , Diabetic Nephropathies/pathology , Disease Models, Animal , Epithelial-Mesenchymal Transition , HEK293 Cells , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout
12.
Am J Transl Res ; 13(5): 4296-4308, 2021.
Article in English | MEDLINE | ID: mdl-34150015

ABSTRACT

Cisplatin is a commonly used chemotherapy drug in cancers, which can lead to acute kidney injury (AKI). AKI can occur in almost one third of tumor patients, who receive cisplatin treatment. microRNAs (miRNAs) are significant tools in regulating the expression of crucial factors in multiple diseases, but little is known about their biological roles in AKI. As exhibited, miR-186 has been observed to be down-regulated in tumors. Our study concentrated on the function of miR-186 in cisplatin-triggered AKI. Here, we reported miR-186 was considerably decreased in the serum samples from AKI patients compared with those from the healthy controls. Additionally, we found in NRK-52E cells exposed to 6 mM cisplatin, miR-186 was greatly decreased time-dependently. Meanwhile, an AKI model in rats was successfully set in our study. Levels of serum creatinine and blood urea nitrogen were significantly induced by cisplatin exposure. In AKI rat models, miR-186 exhibited a rapid decrease in both the serum and the kidney tissues. Then, miR-186 overexpression improved NRK-52E cell proliferation and protected NRK-52E cells against cisplatin-triggered apoptosis. Furthermore, ZEB1 was identified and confirmed as a target gene of miR-186. It has been demonstrated that ZEB1 exerts crucial roles in the development of AKI. As evidenced in our current study, ZEB1 was remarkably elevated in AKI patients and AKI rat models. Moreover, ZEB1 was induced by indicated doses of cisplatin in different time periods in NRK-52E cells. ZEB1 inhibition rescued the reduced proliferation and increased apoptosis of NRK-52E cells. In conclusion, loss miR-186 expression contributed to cisplatin-induced AKI, partly through targeting ZEB1. miR-186 might be provided as an effective biomarker for AKI via targeting ZEB1.

13.
Cell Death Dis ; 11(11): 1008, 2020 11 23.
Article in English | MEDLINE | ID: mdl-33230102

ABSTRACT

Diabetic kidney disease (DKD) is closely associated with the high risk of cardiovascular disease and mortality. Exosomal circRNAs can exert significant roles in the pathology of various diseases. Nevertheless, the role of exosomal circRNAs in DKD progression remains barely known. Circular RNA DLGAP4 has been reported to be in involved in acute ischemic stroke. In our study, we found exosomal circ_DLGAP4 was increased in the exosomes isolated from HG-treated mesangial cells (MCs), DKD patients, and DKD rat models compared with the corresponding normal subjects. Then, we observed that exo-circ_DLGAP4 significantly promoted proliferation and fibrosis of MCs cells. Moreover, to study the underlying mechanism of circ_DLGAP4 in regulating DKD, bioinformatics method was consulted and miR-143 was predicted as its target. The direct correlation between miR-143 and circ_DLGAP4 was validated in MCs. MCs proliferation and fibrosis were increased by circ_DLGAP4, which could be decreased by mimic-miR-143. Next, elevated expression of Erb-b2 receptor tyrosine kinase 3 (ERBB3) is involved in various diseases. However, the function of ERBB3 in DKD development remains poorly known. Next, ERBB3 was predicted as the downstream target for miR-143. It was displayed that circ_DLGAP4 promoted proliferation and fibrosis of MCs by sponging miR-143 and regulating ERBB3/NF-κB/MMP-2 axis. Meanwhile, the loss of exo-circ_DLGAP4 induced miR-143 and repressed ERBB3/NF-κB/MMP-2 expression in MCs. Subsequently, in vivo assays were performed and it was proved that overexpression of circ_DLGAP4 markedly promoted DKD progression in vivo via modulating miR-143/ERBB3/NF-κB/MMP-2. In conclusion, we indicated that exosomal circ_DLGAP4 could prove a novel insight for DKD development.


Subject(s)
Diabetic Nephropathies/metabolism , Matrix Metalloproteinase 2/metabolism , MicroRNAs/metabolism , RNA, Circular/metabolism , Receptor, ErbB-3/metabolism , SAP90-PSD95 Associated Proteins/genetics , Animals , Cell Proliferation/physiology , Diabetic Nephropathies/genetics , Diabetic Nephropathies/pathology , Disease Progression , Exosomes/genetics , Exosomes/metabolism , Humans , Matrix Metalloproteinase 2/genetics , Mice , MicroRNAs/genetics , RNA, Circular/genetics , Receptor, ErbB-3/genetics , Signal Transduction , Transfection
14.
Phys Rev Lett ; 122(6): 063901, 2019 Feb 15.
Article in English | MEDLINE | ID: mdl-30822094

ABSTRACT

Superscattering, induced by degenerate resonances, breaks the fundamental single-channel limit of the scattering cross section of subwavelength structures; in principle, an arbitrarily large total cross section can be achieved via superscattering. It thus provides a unique way to strengthen the light-matter interaction at the subwavelength scale, and has many potential applications in sensing, energy harvesting, bioimaging (such as magnetic resonance imaging), communication, and optoelectronics. However, the experimental demonstration of superscattering remains an open challenge due to its vulnerability to structural imperfections and intrinsic material losses. Here we report the first experimental evidence for superscattering by demonstrating the superscattering simultaneously in two different frequency regimes through both the far-field and near-field measurements. The underlying mechanism for the observed superscattering is the degenerate resonances of confined surface waves, by utilizing a subwavelength metasurface-based multilayer structure. Our work paves the way towards practical applications based on superscattering.

15.
J Cell Physiol ; 234(9): 15563-15569, 2019 Sep.
Article in English | MEDLINE | ID: mdl-30740669

ABSTRACT

The phenotypic changes of tubular epithelial cell are hallmark features of renal diseases caused by abnormal uric acid levels. We hereby intend to investigate whether PI3K/p-Akt signaling plays a role in uric-acid induced epithelial-mesenchymal transition process. The normal rat kidney cell line (NRK-52E) was used as a proximal tubular cell model in this study. NRK-52E cells were exposed to different concentrations of uric acid, or PI3K inhibitor LY294002, or both, respectively. The effects of uric acid on cell morphology were examined by phase contrast microscopy, while molecular alternations were assessed by western blot analysis and immunofluorescence staining. We found that uric acid induced visible morphological alterations in NRK-52E cells accompanied by increased expression of α-smooth muscle actin and reduced expression of E-cadherin. Moreover, phosphorylation of Akt protein was obviously increased, whereas Akt level remained stable. Furthermore, the above effects were abolished when PI3K/p-Akt pathway was blocked by the PI3K inhibitor. These findings demonstrated that high uric acid could induce phenotypic transition of cultured renal tubular cells, which was probably via activating PI3K/p-Akt signaling pathway.

16.
J Phys Condens Matter ; 30(14): 144007, 2018 Apr 11.
Article in English | MEDLINE | ID: mdl-29480167

ABSTRACT

The unique gate-voltage dependent optical properties of graphene make it a promising electrically-tunable plasmonic material. In this work, we proposed in situ control of the polarization of nanoantennas by combining plasmonic structures with an electrostatically tunable graphene monolayer. The tunable polarizer is designed based on an asymmetric cross nanoantenna comprising two orthogonal metallic dipoles sharing the same feed gap. Graphene monolayer is deposited on a Si/SiO2 substrate, and inserted beneath the nanoantenna. Our modelling demonstrates that as the chemical potential is incremented up to 1 eV by electrostatic doping, resonant wavelength for the longer graphene-loaded dipole is blue shifted for 500 nm (~10% of the resonance) in the mid-infrared range, whereas the shorter dipole experiences much smaller influences due to the unique wavelength-dependent optical properties of graphene. In this way, the relative field amplitude and phase between the two dipole nanoantennas are electrically adjusted, and the polarization state of the reflected wave can be electrically tuned from the circular into near-linear states with the axial ratio changing over 8 dB. Our study thus confirms the strong light-graphene interaction with metallic nanostructures, and illuminates promises for high-speed electrically controllable optoelectronic devices.

17.
Med Sci Monit ; 24: 453-460, 2018 Jan 24.
Article in English | MEDLINE | ID: mdl-29362353

ABSTRACT

BACKGROUND Cutaneous squamous cell carcinoma (cSCC) is the second most widespread cancer in humans and its incidence is rising. Novel therapy with better efficacy is needed for clinical treatment of cSCC. Many studies have shown the importance of DNA repair pathways during the development of cancer. A key nucleotide excision repair (NER) protein, xeroderma pigmentosum group D (XPD), is responsible for the excision of a large variety of bulky DNA lesions. MATERIAL AND METHODS To explore the role of XPD in A431 cells, we overexpressed XPD in A431 cells and performed MTT assay, flow cytometry, and Western blot analysis to examine cell proliferation, cell apoptosis, and genes expression. RESULTS We found that the overexpression of XPD suppressed cell viability, induced cell cycle arrest at G1 phase, and promoted cell apoptosis. Additionally, XPD blocked the expression of c-myc, cdc25A, and cdk2, and improved the levels of HIPK2 and p53. CONCLUSIONS These results provide new evidence to reveal the role of XPD in cSCC A431 cells and suggest that XPD may serve as an anti-oncogene during cSCC development.


Subject(s)
Apoptosis , Carcinoma, Squamous Cell/pathology , Cell Cycle , Skin Neoplasms/pathology , Xeroderma Pigmentosum/metabolism , Apoptosis/genetics , Carcinoma, Squamous Cell/genetics , Cell Cycle/genetics , Cell Cycle Checkpoints/genetics , Cell Line, Tumor , Cell Proliferation/genetics , G1 Phase/genetics , Gene Expression Regulation, Neoplastic , Humans , Skin Neoplasms/genetics
18.
Sci Rep ; 6: 18872, 2016 Jan 07.
Article in English | MEDLINE | ID: mdl-26738692

ABSTRACT

Nanoantennas have demonstrated unprecedented capabilities for manipulating the intensity and direction of light emission over a broad frequency range. The directional beam steering offered by nanoantennas has important applications in areas including microscopy, spectroscopy, quantum computing, and on-chip optical communication. Although both the physical principles and experimental realizations of directional linear nanoantennas has become increasingly mature, angular control of nonlinear radiation using nanoantennas has not been explored yet. Here we propose a novel concept of nonlinear Yagi-Uda nanoantenna to direct second harmonic radiation from a metallic nanosphere. By carefully tuning the spacing and dimensions of two lossless dielectric elements, which function respectively as a compact director and reflector, the second harmonic radiation is deflected 90 degrees with reference to the incident light (pump) direction. This abnormal light-bending phenomenon is due to the constructive and destructive interference between the second harmonic radiation governed by a special selection rule and the induced electric dipolar and magnetic quadrupolar radiation from the two dielectric antenna elements. Simultaneous spectral and spatial isolation of scattered second harmonic waves from incident fundamental waves pave a new way towards nonlinear signal detection and sensing.

19.
Opt Express ; 21(9): 10412-21, 2013 May 06.
Article in English | MEDLINE | ID: mdl-23669897

ABSTRACT

Reflection and transmission of electromagnetic waves at the boundaries of periodic composites (electromagnetic/optical metamaterials) depends in general on both bulk and surface waves. We investigate the interplay of these two contributions using three-dimensional full-wave numerical simulations and a recently developed non-asymptotic homogenization theory.


Subject(s)
Electromagnetic Fields , Manufactured Materials , Models, Theoretical , Scattering, Radiation , Computer Simulation , Surface Properties
20.
Chemosphere ; 88(2): 145-54, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22483728

ABSTRACT

Photoelectrocatalytic (PEC) technology involved applying an electrical bias to a TiO(2) film electrode, has been widely applied to the degradation of refractory organic pollutants, owing to its high degradation efficiency. This paper reviews recent developments in the PEC degradation of recalcitrant organic contaminants using a TiO(2) film electrode. The preparation and application of various TiO(2) film electrodes have been investigated, as well as the parameters that influence PEC activity such as the crystal structure, the film thickness and substrate material, the applied electrical bias, the solution pH and conductivity. The improvement of PEC activity by doping the TiO(2) film electrode with metal and non-metal ions has been discussed. The mechanism and kinetics for the PEC degradation of organic pollutants have also been highlighted.


Subject(s)
Electrodes , Environmental Pollutants/chemistry , Environmental Restoration and Remediation/methods , Organic Chemicals/chemistry , Titanium/chemistry , Electrolysis , Environmental Pollutants/analysis , Organic Chemicals/analysis , Photolysis
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