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1.
Nat Mater ; 22(10): 1203-1209, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37349396

RESUMO

Topological photonics is rapidly expanding. However, discovering three-dimensional topological electromagnetic systems can be more challenging than electronic systems for two reasons. First, the vectorial nature of electromagnetic waves results in complicated band dispersions, and simple tight-binding-type predictions usually fail. Second, topological electromagnetic surface modes inside the light cone have very low quality factors (Q factors). Here, we propose the concept of scalar topological photonics to address these challenges. Our approach is experimentally validated by employing a nested meta-crystal configuration using connected coaxial waveguides. They exhibit scalar-wave-like band dispersions, making the search for photonic topological phases an easier task. Their surface states have skyrmion-like electric field distributions, resulting in a whole, bright surface state band inside the light cone continuum. As such, the topological surface states in our three-dimensional nested crystals can be exposed to air, making such systems well-suited for practical applications.

2.
BMC Ophthalmol ; 24(1): 118, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38481176

RESUMO

BACKGROUND: Anti-vascular endothelial growth factor (anti-VEGF) therapy is used for myopic choroidal neovascularization (mCNV). Patchy chorioretinal atrophy (pCRA) enlargement has been reported in mCNV cases associated with vision loss. Our aim was to compare the long-term effectiveness of anti-VEGF therapy alone versus anti-VEGF followed by posterior scleral reinforcement (PSR) in controlling myopic maculopathy in mCNV eyes. METHODS: We performed a retrospective review of the medical records of 95 high myopia patients (refractive error ≥ 6.00 diopters, axial length ≥ 26.0 mm) with mCNV. Patients were treated with anti-VEGF alone (group A) or anti-VEGF followed by PSR (group B). The following data were collected: refractive error, best corrected visual acuity (BCVA), ophthalmic fundus examination, ocular coherence tomography and ocular biometry at 12 and 24 months pre- and postoperatively. The primary outcomes were changes in pCRA and BCVA. RESULTS: In 26 eyes of 24 patients, the mean pCRA size significantly increased from baseline (0.88 ± 1.69 mm2) to 12 months (1.57 ± 2.32 mm2, t = 3.249, P = 0.003) and 24 months (2.17 ± 2.79 mm2, t = 3.965, P = 0.001) postoperatively. The increase in perilesional pCRA in group B (n = 12) was 98.2% and 94.2% smaller than that in group A (n = 14) at 12 and 24 months (Beta 0.57 [95% CI 0.01, 191 1.13], P = 0.048). In group B, 7 eyes (58.3%) gained more than 2 lines of BCVA compared with only 4 eyes (28.6%) in group A at 24 months. CONCLUSION: Anti-VEGF therapy followed by PSR achieved better outcomes than anti-VEGF therapy alone in controlling the development of myopic maculopathy in mCNV and may constitute a better treatment option by securing a better long-term VA outcome.


Assuntos
Neovascularização de Coroide , Degeneração Macular , Miopia Degenerativa , Doenças Retinianas , Humanos , Inibidores da Angiogênese/uso terapêutico , Fatores de Crescimento Endotelial/uso terapêutico , Miopia Degenerativa/complicações , Miopia Degenerativa/diagnóstico , Acuidade Visual , Neovascularização de Coroide/diagnóstico , Neovascularização de Coroide/tratamento farmacológico , Neovascularização de Coroide/etiologia , Doenças Retinianas/diagnóstico , Degeneração Macular/tratamento farmacológico , Esclera , Estudos Retrospectivos , Tomografia de Coerência Óptica , Angiofluoresceinografia , Injeções Intravítreas
3.
Pharmacol Res ; 195: 106863, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37480971

RESUMO

Human papillomavirus (HPV) infection is a causative agent of cervical cancer (CC). N6-methyladenosine (m6A) modification is implicated in carcinogenesis and tumor progression. However, the involvement of m6A modification in HPV-involved CC remains unclear. Here we showed that HPV E6/7 oncoproteins affected the global m6A modification and E7 specifically promoted the expression of ALKBH5. We found that ALKBH5 was significantly upregulated in CC and might serve as a valuable prognostic marker. Forced expression of ALKBH5 enhanced the malignant phenotypes of CC cells. Mechanistically, we discovered that E7 increased ALKBH5 expression through E2F1-mediated activation of the H3K27Ac and H3K4Me3 histone modifications, as well as post-translational modification mediated by DDX3. ALKBH5-mediated m6A demethylation enhanced the expression of PAK5. The m6A reader YTHDF2 bound to PAK5 mRNA and regulated its stability in an m6A-dependent manner. Moreover, ALKBH5 promoted tumorigenesis and metastasis of CC by regulating PAK5. Overall, our findings herein demonstrate a significant role of ALKBH5 in CC progression in HPV-positive cells. Thus, we propose that ALKBH5 may serve as a prognostic biomarker and therapeutic target for CC patients.


Assuntos
Infecções por Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Infecções por Papillomavirus/genética , Carcinogênese/genética , Homólogo AlkB 5 da RNA Desmetilase/genética , Homólogo AlkB 5 da RNA Desmetilase/metabolismo
4.
Acta Pharmacol Sin ; 44(9): 1890-1905, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37095198

RESUMO

Due to poor T cell infiltration, tumors evade immune surveillance. Increased CD8+ T cell infiltration in breast cancer suggests a satisfactory response to immunotherapy. COPS6 has been identified as an oncogene, but its role in regulating antitumor immune responses has not been defined. In this study, we investigated the impact of COPS6 on tumor immune evasion in vivo. Tumor transplantation models were established in C57BL/6 J mice and BALB/c nude mice. Flow cytometry was conducted to identify the role of COPS6 on tumor-infiltrating CD8+ T cells. By analyzing the TCGA and GTEx cohort, we found that COPS6 expression was significantly up-regulated in a variety of cancers. In human osteosarcoma cell line U2OS and non-small cell lung cancer cell line H1299, we showed that p53 negatively regulated COPS6 promoter activity. In human breast cancer MCF-7 cells, COPS6 overexpression stimulated p-AKT expression as well as the proliferation and malignant transformation of tumor cells, whereas knockdown of COPS6 caused opposite effects. Knockdown of COPS6 also significantly suppressed the growth of mouse mammary cancer EMT6 xenografts in BALB/c nude mice. Bioinformatics analysis suggested that COPS6 was a mediator of IL-6 production in the tumor microenvironment and a negative regulator of CD8+ T cell tumor infiltration in breast cancer. In C57BL6 mice bearing EMT6 xenografts, COPS6 knockdown in the EMT6 cells increased the number of tumor-infiltrating CD8+ T cells, while knockdown of IL-6 in COPS6KD EMT6 cells diminished tumor infiltrating CD8+ T cells. We conclude that COPS6 promotes breast cancer progression by reducing CD8+ T cell infiltration and function via the regulation of IL-6 secretion. This study clarifies the role of p53/COPS6/IL-6/CD8+ tumor infiltrating lymphocytes signaling in breast cancer progression and immune evasion, opening a new path for development of COPS6-targeting therapies to enhance tumor immunogenicity and treat immunologically "cold" breast cancer.


Assuntos
Neoplasias da Mama , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Animais , Camundongos , Feminino , Linfócitos T CD8-Positivos/metabolismo , Neoplasias da Mama/patologia , Interleucina-6/metabolismo , Camundongos Nus , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Evasão Tumoral , Proteína Supressora de Tumor p53/metabolismo , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos C57BL , Microambiente Tumoral , Linhagem Celular Tumoral , Complexo do Signalossomo COP9/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo
5.
Nano Lett ; 22(2): 688-694, 2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35025516

RESUMO

On-chip nanoscale optical platforms capable of efficient second harmonic generation (SHG) are highly desired for optical sensing, subwavelength coherent sources, and quantum photonic devices. Here, we develop a remotely excited dual cavity resonance scheme to achieve significantly enhanced SHG in a CdSe nanobelt on Au film hybrid waveguide system. The SHG emission with superior efficiency originates from counter-propagating plasmonic modes interference in a horizontal Fabry-Pérot (FP) cavity enabled by remote excitation of propagating surface plasmons, which is further enhanced through a vertical FP cavity. With this effective cooperation of hybrid plasmon modes and FP cavity modes, 2 orders of magnitude enhancement of the conversion efficiency (3.5 × 10-4 W-1) is achieved compared to the off-resonance case. Our design provides new insight into the development of a multifunctional hybrid plasmonic device toward on-chip nonlinear nanophotonic applications.

6.
Pediatr Res ; 91(6): 1600-1605, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-33947999

RESUMO

BACKGROUND: The objective of this study was to examine the association of an integrated model (composed of retinal arteriolar caliber, height, and sex) with blood pressure (BP) among a group of Chinese children, and assess the predictive value of the integrated model for childhood hypertension. METHODS: This study included 1460 candidates aged 12.634 ± 0.420 years. Height, weight, waist circumference, and BP were obtained and ophthalmological measurements were taken. The computer-imaging program (IVAN, University of Wisconsin, Madison, WI) was used to measure calibers of retinal vessels. Receiver-operating characteristic curve (ROC) analyses were performed to assess the accuracy of the integrated model as a diagnostic test of elevated BP in children. RESULTS: The accuracy of the integrated model (assessed by area under the curve) for identifying elevated BP was 0.777 (95% confidence interval: 0.742-0.812). The optimal threshold of the integrated model for defining hypertension was 0.153, and the calculation formula for the specific predictive risk was: Logit (p/1 - p) = -5.666 - 0.261 × retinal arteriolar caliber + 0.945 × sex + 0.438 × height. In identifying elevated BP, the sensitivity and specificity were 0.711 and 0.736, respectively. CONCLUSIONS: The model containing eye message is a comprehensive and relatively effective index to identify elevated BP in 12-year-old children, which can offer assistance to further understand childhood microcirculation disease. IMPACT: We firstly incorporated retinal vascular diameter, sex, and height into one integrated model to identify hypertension in 12-year-old children. The current discrimination of hypertension in children is difficult. There have been some studies to simplify the diagnosis of children's hypertension, but they were limited to anthropometric measurements. We proposed a composed model containing microcirculation information to predict childhood hypertension. Based on the knowledge that microcirculation is not only a means to study the manifestations but also early pathogenic correlates of hypertension, the combined model containing microcirculation message as a method may provide new insights into the diagnosis of childhood hypertension.


Assuntos
Doenças do Sistema Nervoso Autônomo , Hipertensão , Arteríolas , Pressão Sanguínea/fisiologia , Estatura , Índice de Massa Corporal , Criança , Humanos , Hipertensão/diagnóstico , Circunferência da Cintura
7.
Phys Rev Lett ; 126(11): 117402, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33798377

RESUMO

Bound states in the continuum (BICs) confine resonances embedded in a continuous spectrum by eliminating radiation loss. Merging multiple BICs provides a promising approach to further reduce the scattering losses caused by fabrication imperfections. However, to date, BIC merging has been limited to only the Γ point, which constrains potential application scenarios such as beam steering and directional vector beams. Here, we propose a new scheme to construct merging BICs at almost an arbitrary point in reciprocal space. Our approach utilizes the topological features of BICs on photonic crystal slabs, and we merge a Friedrich-Wintgen BIC and an accidental BIC. The Q factors of the resulting merging BIC are enhanced for a broad wave vector range compared with both the original Friedrich-Wintgen BIC and the accidental BIC. Since Friedrich-Wintgen BICs and accidental BICs are quite common in the band structure, our proposal provides a general approach to realize off-Γ merging BICs with superhigh Q factors that can substantially enhance nonlinear and quantum effects and boost the performance of on-chip photonic devices.

8.
Langmuir ; 37(37): 11115-11122, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34505769

RESUMO

There have been many studies on special wetting surfaces, but most of them just stay superlyophobic in air or underwater. In this work, a membrane with photoresponse is fabricated by spraying hybrid particles of silicon and titanium dioxide. Under the combined action of hybrid particles and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, the prepared membrane is superhydrophobic in air. Because of the presence of titanium dioxide, the membrane can realize the transformation from superoleophilic underwater to superoleophobic underwater through UV irradiation and heating. Surprisingly, the membranes with superoleophobicity underwater are also superhydrophobic underoil. Thanks to this unique wettability transition, the prepared membrane can be applied to emulsion separation and fog harvesting. This is inspiring for the preparation and the multifunctional application of multiphase media superlyophobic surfaces.

9.
Cochrane Database Syst Rev ; 12: CD012687, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33336797

RESUMO

BACKGROUND: Refractive errors (conditions in which the eye fails to focus objects accurately on the retina due to defects in the refractive system), are the most common cause of visual impairment. Myopia, hyperopia, and astigmatism are low-order aberrations, usually corrected with spectacles, contact lenses, or conventional refractive surgery. Higher-order aberrations (HOAs) can be quantified with wavefront aberration instruments and corrected using wavefront-guided or wavefront-optimized laser surgery. Wavefront-guided ablations are based on preoperative measurements of HOAs; wavefront-optimized ablations are designed to minimize induction of new HOAs while preserving naturally occurring aberrations. Two wavefront procedures are expected to produce better visual acuity than conventional procedures. OBJECTIVES: The primary objective was to compare effectiveness and safety of wavefront procedures, laser-assisted in-situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) or laser epithelial keratomileusis (LASEK) versus corresponding conventional procedures, for correcting refractive errors in adults for postoperative uncorrected visual acuity, residual refractive errors, and residual HOAs. The secondary objective was to compare two wavefront procedures. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, which contains the Cochrane Eyes and Vision Trials Register; 2019, Issue 8); Ovid MEDLINE; Ovid Embase; Latin American and Caribbean Health Sciences (LILACS); the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 6 August 2019. We imposed no restrictions by language or year of publication. We used the Science Citation Index (September 2013) and searched the reference lists of included trials to identify additional relevant trials. SELECTION CRITERIA: We included randomized controlled trials (RCTs) comparing either wavefront modified with conventional refractive surgery or wavefront-optimized with wavefront-guided refractive surgery in participants aged ⪰ 18 years with refractive errors. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology. MAIN RESULTS: We identified 33 RCTs conducted in Asia, Europe and United States, totaling 1499 participants (2797 eyes). Participants had refractive errors ranging from high myopia to low hyperopia. Studies reported at least one of the following review-specific outcomes based on proportions of eyes: with uncorrected visual acuity (UCVA) of 20/20 or better, without loss of one or more lines of best spectacle-corrected visual acuity (BSCVA), within ± 0.50 diopters (D) of target refraction, with HOAs and adverse events. Study characteristics and risk of bias Participants were mostly women, mean age 29 and 53 years, and without previous refractive surgery, ocular pathology or systemic comorbidity. We could not judge risks of bias for most domains of most studies. Most studies in which both eyes of a participant were analyzed failed to account for correlations between two eyes in the analysis and reporting of outcomes. Findings For the primary comparison between wavefront (PRK or LASIK or LASEK) and corresponding conventional procedures, 12-month outcome data were available from only one study of PRK with 70 participants. No evidence of more favorable outcomes of wavefront PRK on proportion of eyes: with UCVA of 20/20 or better (risk ratio [RR] 1.03, 95% confidence interval (CI) 0.86 to 1.24); without loss of one or more lines of BSCVA (RR 0.94, 95% CI 0.81 to 1.09); within ± 0.5 D of target refraction (RR 1.03, 95% CI 0.86 to 1.24); and mean spherical equivalent (mean difference [MD] 0.04, 95% CI -0.11 to 0.18). The evidence for each effect estimate was of low certainty. No study reported HOAs at 12 months. At six months, the findings of two to eight studies showed that overall effect estimates and estimates by subgroup of PRK or LASIK or LASEK were consistent with those for PRK at 12 month, and suggest no difference in all outcomes. The certainty of evidence for each outcome was low. For the comparison between wavefront-optimized and wavefront-guided procedures at 12 months, the overall effect estimates for proportion of eyes: with UCVA of 20/20 or better (RR 1.00, 95% CI 0.99 to 1.02; 5 studies, 618 participants); without loss of one or more lines of BSCVA (RR 0.99, 95% CI 0.96 to 1.02; I2 = 0%; 5 studies, 622 participants); within ± 0.5 diopters of target refraction (RR 1.02, 95% CI 0.95 to 1.09; I2 = 33%; 4 studies, 480 participants) and mean HOAs (MD 0.03, 95% CI -0.01 to 0.07; I2 = 41%; 5 studies, 622 participants) showed no evidence of a difference between the two groups. Owing to substantial heterogeneity, we did not calculate an overall effect estimate for mean spherical equivalent at 12 months, but point estimates consistently suggested no difference between wavefront-optimized PRK versus wavefront-guided PRK. However, wavefront-optimized LASIK compared with wavefront-guided LASIK may improve mean spherical equivalent (MD -0.14 D, 95% CI -0.19 to -0.09; 4 studies, 472 participants). All effect estimates were of low certainty of evidence. At six months, the results were consistent with those at 12 months based on two to six studies. The findings suggest no difference between two wavefront procedures for any of the outcomes assessed, except for the subgroup of wavefront-optimized LASIK which showed probable improvement in mean spherical equivalent (MD -0.12 D, 95% CI -0.19 to -0.05; I2 = 0%; 3 studies, 280 participants; low certainty of evidence) relative to wavefront-guided LASIK. We found a single study comparing wavefront-guided LASIK versus wavefront-guided PRK at six and 12 months. At both time points, effect estimates consistently supported no difference between two procedures. The certain of evidence was very low for all estimates. Adverse events Significant visual loss or optical side effects that were reported were similar between groups. AUTHORS' CONCLUSIONS: This review suggests that at 12 months and six months postoperatively, there was no important difference between wavefront versus conventional refractive surgery or between wavefront-optimized versus wavefront-guided surgery in the clinical outcomes analyzed. The low certainty of the cumulative evidence reported to date suggests that further randomized comparisons of these surgical approaches would provide more precise estimates of effects but are unlikely to modify our conclusions. Future trials may elect to focus on participant-reported outcomes such as satisfaction with vision before and after surgery and effects of remaining visual aberrations, in addition to contrast sensitivity and clinical outcomes analyzed in this review.


Assuntos
Aberrações de Frente de Onda da Córnea/cirurgia , Ceratectomia Subepitelial Assistida por Laser/métodos , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Lasers de Excimer/uso terapêutico , Ceratectomia Fotorrefrativa/métodos , Adulto , Astigmatismo/cirurgia , Feminino , Humanos , Hiperopia/cirurgia , Ceratectomia Subepitelial Assistida por Laser/efeitos adversos , Ceratomileuse Assistida por Excimer Laser In Situ/efeitos adversos , Masculino , Pessoa de Meia-Idade , Miopia/cirurgia , Ceratectomia Fotorrefrativa/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento , Acuidade Visual
10.
Mediators Inflamm ; 2020: 1240152, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33354159

RESUMO

Previous study showed that low protein diet-fed pigs are characterized by lower histidine concentration in the serum and muscle, suggesting that histidine may involve in protein-restricted response. Thus, the current study mainly investigated the effects of dietary histidine on growth performance, blood biochemical parameters and amino acids, intestinal morphology, and microbiota communities in low protein diet-challenged-piglets. The results showed that protein restriction inhibited growth performance, blood biochemical parameters and amino acids, and gut microbiota but had little effect on intestinal morphology. Dietary supplementation with histidine markedly enhanced serum histidine level and restored tryptophan concentration in low protein diet-fed piglets, while growth performance and intestinal morphology were not markedly altered in histidine-treated piglets. In addition, histidine exposure failed to affect bacterial diversity (observed species, Shannon, Simpson, Chao1, ACE, and phylogenetic diversity), but histidine-treated piglets exhibited higher abundances of Butyrivibrio and Bacteroides compared with the control and protein-restricted piglets. In conclusion, dietary histidine in low protein diet enhanced histidine concentration and affected gut microbiota (Butyrivibrio and Bacteroides) but failed to improve growth performance and intestinal morphology.


Assuntos
Aminoácidos/sangue , Dieta com Restrição de Proteínas , Microbioma Gastrointestinal , Histidina/administração & dosagem , Intestinos/patologia , Suínos/crescimento & desenvolvimento , Animais , Dieta , Masculino , Tamanho do Órgão
11.
Nano Lett ; 19(6): 3838-3845, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31125243

RESUMO

Developing highly efficient nanoscale coherent light sources is essential for advances in technological applications such as integrated photonic circuits, bioimaging, and sensing. An on-chip wavelength convertor based on second harmonic generation (SHG) would be a crucial step toward this goal, but the light-conversion efficiency would be low for small device dimensions. Here we demonstrate strongly enhanced SHG with a high conversion efficiency of 4 × 10-5 W-1 from a hybrid plasmonic waveguide consisting of a CdSe nanowire coupled with a Au film. The strong spatial overlap of the waveguide mode with the nonlinear material and momentum conservation between the incident and reflected modes are the key factors resulting in such high efficiency. The SHG emission angles vary linearly with excitation wavelength, indicating a nonlinear steering of coherent light emission at the subwavelength scale. Our work is promising for the realization of efficient and tunable nonlinear coherent sources and opens new approaches for efficient integrated nonlinear nanophotonic devices.

12.
BMC Ophthalmol ; 18(1): 133, 2018 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-29866094

RESUMO

BACKGROUND: To establish the independent association between blood pressure (BP) and retinal vascular caliber, especially the retinal venular caliber, in a population of 12-year-old Chinese children. METHODS: We have examined 1501 students in the 7th grade with mean age of 12.7 years. A non-mydriatic fundus camera (Canon CR-2, Tokyo, Japan) was used to capture 450 fundus images of the right eyes. Retinal vascular caliber was measured using a computer-based program (IVAN). BP was measured using an automated sphygmomanometer (HEM-907, Omron, Kyoto, Japan). RESULTS: The mean retinal arteriolar caliber was 145.3 µm (95% confidence interval [CI], 110.6-189.6 µm) and the mean venular caliber was 212.7 µm (95% CI, 170.6-271.3 µm). After controlling for age, sex, axial length, BMI, waist, spherical equivalent, birth weight, gestational age and fellow retinal vessel caliber, children in the highest quartile of BP had significantly narrower retinal arteriolar caliber than those with lower quartiles (P for trend< 0.05). Each 10-mmHg increase in BP was associated with narrowing of the retinal arterioles by 3.00 µm (multivariable-adjusted P < 0.001), and the results were consist in three BP measurements. The association between BP measures and retinal venular caliber did not persist after adjusting for fellow arteriolar caliber. And there was no significant interaction between BP and sex, age, BMI, and birth status. CONCLUSIONS: In a large population of adolescent Chinese children, higher BP was found to be associated with narrower retinal arterioles, but not with retinal venules. Sex and other confounding factors had no effect on the relationship of BP and retinal vessel diameter.


Assuntos
Arteríolas/fisiologia , Pressão Sanguínea/fisiologia , Vasos Retinianos/fisiologia , Vênulas/fisiologia , Adolescente , Comprimento Axial do Olho/fisiologia , Índice de Massa Corporal , Criança , China , Estudos Transversais , Feminino , Humanos , Masculino , Análise de Regressão , Fatores Sexuais
13.
Nano Lett ; 17(12): 7803-7808, 2017 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-29140716

RESUMO

Coherently adding up signal wave from different locations are a prerequisite for realizing efficient nonlinear optical processes in traditional optical configurations. While nonlinear optical processes in plasmonic waveguides with subwavelength light confinement are in principle desirable for enhancing nonlinear effects, so far it has been difficult to improve the efficiency due to the large momentum mismatch. Here we demonstrate, using remotely excited surface plasmon polaritons (SPPs), axial collimated but transversely divergent second harmonic (SH) generation in a single silver nanowire-monolayer molybdenum disulfide hybrid system. Fourier imaging of the generated SH signal confirms the momentum conservation conditions between the incident and reflected SPPs and reveals distinct features inherent to the 1D plasmonic waveguides: (i) the SH photons are collimated perpendicular to the nanowire axis but are divergent within the perpendicular plane; (ii) the collimation (divergence) is inversely proportional to the length of the active region (lateral confinement of the SPPs); and (iii) the SH emission pattern resembles that of an aligned dipole chain on top of the substrate with an emission peak at the critical angle. Our results pave the way to generate and manipulate SH emission around subwavelength waveguides and open up new possibilities for realizing high efficiency on-chip nonlinear optics.

14.
Nano Lett ; 17(6): 3809-3814, 2017 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-28530102

RESUMO

Strong coupling between plasmons and excitons in nanocavities can result in the formation of hybrid plexcitonic states. Understanding the dispersion relation of plexcitons is important both for fundamental quantum science and for applications including optoelectronics and nonlinear optics devices. The conventional approach, based on statistics over different nanocavities, suffers from large inhomogeneities from the samples, owing to the nonuniformity of nanocavities and the lack of control over the locations and orientations of the excitons. Here we report the first measurement of the dispersion relationship of plexcitons in an individual nanocavity. Using a single silver nanorod as a Fabry-Pérot nanocavity, we realize strong coupling of plasmon in single nanocavity with excitons in a single atomic layer of tungsten diselenide. The plexciton dispersion is measured by in situ redshifting the plasmon energy via successive deposition of a dielectric layer. Room-temperature formation of plexcitons with Rabi splittings as large as 49.5 meV is observed. The realization of strong plasmon-exciton coupling by in situ tuning of the plasmon provides a novel route for the manipulation of excitons in semiconductors.

15.
Artigo em Inglês | MEDLINE | ID: mdl-29172965

RESUMO

Surface sediment samples were collected from the Pacific sector of the Arctic Ocean during the 6th Chinese National Arctic Research Expedition (CHINARE), 2014. Concentrations and extractabilities of six toxic metals (Cd, Cr, Cu, Ni, Pb, and Zn) were determined using a modified sequential extraction procedure as described by the European Community Bureau of Reference (BCR). A new analytical hierarchy approach to risk assessment, involving sediment quality guidelines and risk-assessment codes, is described for metals in marine sediments from the Arctic Ocean. Results indicate a mobility order of Pb > Cd > Cu > Zn > Ni > Cr with mean liable fraction (F1+F2+F3) being 83.0%, 81.6%, 62.0%, 47.1%, 42.1%, and 15.6%, respectively. Ni presents the most serious ecological risk in the study area, with most samples (93.9%) indicating medium risk, followed by Cu (54.5%) and Zn (27.3%). For Ni and Zn, there are also samples showing high ecological risk (Ni at site NB02, northern Bering Sea; Zn at R07, northern Chukchi Sea). The ecological risk for Cr indicates low ecological risk (93.9%) and some medium risk (6.1%). All Cd assessments indicate low ecological risk, while most Pb assessments indicate zero (33.3%) to low risk. The new ecological risk assessment method improves on assessments based on metal mobility or concentration alone.


Assuntos
Fracionamento Químico/métodos , Sedimentos Geológicos/química , Metais Pesados/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Regiões Árticas , Monitoramento Ambiental , União Europeia , Metais Pesados/análise , Oceanos e Mares , Medição de Risco , Água do Mar/química , Poluentes Químicos da Água/análise
16.
Graefes Arch Clin Exp Ophthalmol ; 255(1): 189-195, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27796670

RESUMO

PURPOSE: To investigate the effects of no correction versus full correction on myopia progression in Chinese children over a period of 2 years. METHODS: Myopia was defined as cycloplegic spherical equivalent (SE) of ≤ -0.50 D. Uncorrection was defined as no spectacles worn, and full correction was defined as when the value of SE subtracted from the dioptric power of the child's current spectacles was less than 0.5 D. Ocular examinations included visual acuity, cycloplegic autorefraction, axial length and vertometer measurements. Questionnaires were completed by parents on behalf of the children. RESULTS: A total of 121 myopic children, with a median age of 12.7 years, were screened from the Anyang Childhood Eye Study, with 65 in the uncorrected group and 56 in the full correction group. At 2-year follow-up, children with no correction had slower myopia progression (-0.75 ± 0.49 D vs. -1.04 ± 0.49 D, P < 0.01) and less axial elongation (0.45 ± 0.18 mm vs. 0.53 ± 0.17 mm, P = 0.02) than children with full correction. In multivariate modeling, adjusting for baseline SE or axial length, age, gender, height, number of myopic parents, age at myopia onset, and time spent in near work and outdoors, children with no correction still had slower myopia progression (-0.76 ± 0.07 vs. -1.03 ± 0.08 D, P < 0.01) and less axial elongation (0.47 ± 0.03 mm vs. 0.51 ± 0.03 mm, P < 0.01). Myopia progression decreased significantly with an increasing amount of undercorrection in all children (r = 0.22, b = 0.16, P = 0.01). CONCLUSION: Our findings suggest that myopic defocus slows the progression of myopia in already myopic children, supporting previous findings from animal studies.


Assuntos
Acomodação Ocular/fisiologia , Óculos , Miopia/terapia , Refração Ocular/fisiologia , Acuidade Visual , Comprimento Axial do Olho , Criança , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Miopia/fisiopatologia , Inquéritos e Questionários , Fatores de Tempo
17.
Ophthalmic Physiol Opt ; 37(1): 51-59, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27880992

RESUMO

PURPOSE: To evaluate the effect of soft contact lens with concentric ring bifocal and peripheral add multifocal designs on controlling myopia progression in school-aged children. METHODS: We systematically searched MEDLINE, EMBASE, Cochrane Library and reference lists of included trials. Methodological quality of included trials was assessed using Jadad Scale and Newcastle-Ottawa Quality Assessment Scale items. RESULTS: We identified five randomised controlled trials (RCTs) and three cohort studies with a total of 587 myopic children. Compared with the control group, concentric ring bifocal soft contact lenses showed less myopia progression with a weighted mean difference (WMD) of 0.31 D (95% CI, 0.05~0.57 D, p = 0.02) and less axial elongation with a WMD of -0.12 mm (95% CI, approximately -0.18 to -0.07 mm, p < 0.0001) at 12 months. Relative to the control group, peripheral add multifocal soft contact lenses showed less myopia progression with a WMD of 0.22 D (95% CI 0.14~0.31 D, p < 0.0001) and less axial elongation of -0.10 mm (95% CI -0.13~0.07 mm, p < 0.0001) at 12 months, respectively. The soft contact lenses with concentric ring bifocal and peripheral add multifocal designs produced additional myopia control rates of 30~38% for slowing myopia progression and 31~51% for lessening axial elongation within 24 months. CONCLUSIONS: Both concentric ring bifocal and peripheral add multifocal soft contact lenses are clinically effective for controlling myopia in school-aged children, with an overall myopia control rates of 30~50% over 2 years. Concentric ring bifocal soft contact lenses seem to have greater effect than peripheral add multifocal soft contact lenses.


Assuntos
Lentes de Contato , Miopia Degenerativa/terapia , Refração Ocular/fisiologia , Acuidade Visual , Criança , Progressão da Doença , Desenho de Equipamento , Humanos , Miopia Degenerativa/fisiopatologia
18.
Anal Chem ; 88(6): 3144-8, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26867721

RESUMO

Rapid and sensitive monitoring of benzene in water is very important to the health of people and for environmental protection. A novel and online detection method of spray inlet proton transfer reaction mass spectrometry (SI-PTR-MS) was introduced for rapid and sensitive monitoring of trace benzene in water. A spraying extraction system was coupled with the self-developed PTR-MS. The benzene was extracted from the water sample in the spraying extraction system and continuously detected with PTR-MS. The flow of carrier gas and salt concentration in water were optimized to be 50 sccm and 20% (w/v), respectively. The response time and the limit of detection of the SI-PTR-MS for detection of benzene in water were 55 s and 0.14 µg/L at 10 s integration time, respectively. The repeatability of the SI-PTR-MS was evaluated, and the relative standard deviation of five replicate determinations was 4.3%. The SI-PTR-MS system was employed for monitoring benzene in different water matrices, such as tap water, lake water, and wastewater. The results indicated that the online SI-PTR-MS can be used for rapid and sensitive monitoring of trace benzene in water.


Assuntos
Benzeno/análise , Espectrometria de Massas/métodos , Prótons , Poluentes Químicos da Água/análise , Limite de Detecção
19.
Clin Exp Ophthalmol ; 44(8): 701-709, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27082378

RESUMO

BACKGROUND: To report the thickness of the peripapillary retinal nerve fibre layer (pRNFL) in Chinese children and examine its association with refractive error, axial length (AL) and optic disc parameters. DESIGN: Population-based cross-sectional study. PARTICIPANTS: A total of 2893 seven-year-old children from 11 randomly selected primary schools in Anyang, central China. METHODS: Participants underwent ophthalmic examinations including optical biometry, cycloplegic autorefraction and spectral-domain ocular coherence tomography. MAIN OUTCOME MEASURES: Retinal nerve fibre layer thickness in 16 radial sections, cycloplegic spherical equivalent, AL. RESULTS: The mean (SD) average RNFL thickness was 102.01(8.02) µm. The average RNFL thickness decreased with smaller disc area (r = 0.18, R2 = 0.03, P < 0.0001), bigger cup area (r = -0.11, R2 = 0.01, P < 0.0001), smaller rim area (r = 0.28, R2 = 0.08, P < 0.0001), smaller nerve head volume (r = 0.27, R2 = 0.07, P < 0.0001), longer AL (r = -0.15, R2 = 0.02, P < 0.0001) and a negative spherical equivalent (r = 0.11, R2 = 0.01, P < 0.0001). Hyperopic children had a thicker RNFL than emmetropic children [102.45(8.13) µm vs. 100.81 (7.18) µm, P < 0.001]. Myopic children had thinner RNFL than emmetropic children [99.17 (7.69) µm vs. 100.81 (7.18) µm, P < 0.05]. CONCLUSION: Retinal nerve fibre layer thickness decreased with increasing AL, higher myopia, bigger cup area, smaller disc and rim area, and a smaller nerve head volume, but the coefficient of determination for all these associations was small. The RNFL in myopes was significantly thinner than emmetropes or hyperopes, but with small absolute differences. The study provides RNFL values for healthy 7-year-old Chinese children. Follow up of this cohort to observe the change of RNFL thickness with myopia and possible change in detected associations with age is planned.


Assuntos
Hiperopia/fisiopatologia , Miopia/fisiopatologia , Fibras Nervosas/patologia , Células Ganglionares da Retina/patologia , Povo Asiático/etnologia , Comprimento Axial do Olho , Biometria , Criança , Pré-Escolar , China/epidemiologia , Estudos Transversais , Emetropia/fisiologia , Feminino , Humanos , Hiperopia/etnologia , Masculino , Miopia/etnologia , Disco Óptico/patologia , Refração Ocular/fisiologia , Tomografia de Coerência Óptica
20.
Graefes Arch Clin Exp Ophthalmol ; 253(8): 1363-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26032395

RESUMO

BACKGROUND: To prospectively observe the effects of undercorrection of myopia on myopia progression and axial elongation in a population of 12-year-old Chinese children. METHODS: A total of 2,267 children in the Anyang Childhood Eye Study were examined at baseline, and 1,769 were followed for 1 year. Ocular examinations included cycloplegic autorefraction, axial length, visual acuity, vertometry, and accommodative lag. Questionnaires were completed by children and parents. Undercorrection of myopia was determined at baseline if presenting visual acuity could be improved by at least 2 lines with subjective refraction. RESULTS: Of 253 myopic children with spectacles and available information, 120 (47.4 %) were undercorrected (-4.63D to -0.50D) and 133 (52.6 %) were fully corrected. In a multivariate model adjusting for age, gender, number of myopic parents, time spent on near work and outdoor activities per day, usage and time for wearing spectacles per day, children with undercorrection had significantly more baseline myopia (P < 0.01) and longer axial length (P = 0.03) than children with full correction. However, there were no significant differences in myopia progression (P = 0.46) and axial elongation (P = 0.96) at 1 year between the two groups of children. The regression analysis showed that myopia progression significantly decreased with increasing amount of undercorrection (r (2) = 0.02, P = 0.02) in all children. Accommodative lag significantly decreased with increasing amounts of undercorrection (P < 0.01). CONCLUSIONS: Based on this 1-year study in Chinese children, undercorrection or full correction of myopia by wearing spectacles did not show any differences in myopia progression or axial elongation.


Assuntos
Óculos , Miopia/diagnóstico , Miopia/terapia , Acomodação Ocular/fisiologia , Povo Asiático , Comprimento Axial do Olho/patologia , Criança , China/epidemiologia , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Miopia/etnologia , Estudos Prospectivos , Inquéritos e Questionários , Acuidade Visual/fisiologia
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