Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Opt Express ; 31(9): 14109-14118, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37157281

RESUMO

We analyze the guided modes in coupled waveguides made of negative-index materials without gain or loss. We show that it supports non-Hermitian phenomenon on the existence of guided mode versus geometric parameters of the structure. The non-Hermitian effect is different from parity-time (P T) symmetry, and can be explained by a simple coupled-mode theory with an anti-P T symmetry. The existence of exceptional points and slow-light effect are discussed. This work highlights the potential of loss-free negative-index materials in the study of non-Hermitian optics.

2.
Opt Express ; 29(16): 24663-24673, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34614817

RESUMO

We investigate the optical resonances in coupled meta-atoms with hybrid interaction pathways. One interaction pathway is the directly near-field coupling between the two meta-atoms. The other interaction pathway is via the continuum in a waveguide functioned as a common bus connecting them. We show that by properly introducing gain or loss into the meta-atoms, the hybrid optical system becomes parity-time (P T) symmetric, in which the effective coupling rate can be customized by manipulating the length of the waveguide. At the exact phase of the customized P T symmetry, the coupled meta-atoms support discrete super-resonant modes that can be observed from the transmission spectra as extremely sharp peaks. At an exception point where the eigenmodes coalesce, albeit the transmission curve is flat, a high-Q factor of the localized field in the meta-atoms can be obtained. Similarities of the super-resonance with the bound states in the continuum (BICs) are discussed. This investigation promotes our understanding about the ways in realizing high-Q optical resonance especially by manipulating the distributions of loss and gain via the concepts of P T and BICs. Many attractive applications are expected.

3.
BMC Public Health ; 20(1): 133, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32000739

RESUMO

BACKGROUND: Metabolic syndrome (MS) has abruptly increased in China in the past two decades, gradually representing an important public health threat over the years. Here, we firstly reported the prevalence and associated factors of metabolic syndrome in Jiangxi province, China. METHODS: A population-based cross-sectional survey was performed in Jiangxi province, China, from April to August 2015. MS was diagnosed by International Diabetes Federation (IDF) and Chinese Diabetes Society (CDS) criteria, respectively. Factors associated with MS were investigated by multivariate logistic regression. RESULTS: A total of 2665 residents aged over 18 years were enrolled, and 2580 effectively participated. According to IDF and CDS criteria, age-standardized prevalence of MS were 21.1 and 15.2% in all participants, respectively; prevalence were 19.6% or 17.1% in men, and 22.7% or 13.0% in women, based on these respective criteria. Rural participants had a significantly higher prevalence than urban individuals, so did rural females. Prevalence in males did not differ between rural and urban participants. Factors independently associated with MS were low education level and menopausal state. CONCLUSIONS: To the best of our knowledge, this was the latest study on MS prevalence in Jiangxi province. In conclusion, MS prevalence is high in Jiangxi province. Considering the unhealthy lifestyle, education is urgently needed to prevent the rapid increase of MS prevalence.


Assuntos
Síndrome Metabólica/epidemiologia , Adolescente , Adulto , Idoso , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Adulto Jovem
4.
J Recept Signal Transduct Res ; 39(1): 80-86, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31210570

RESUMO

The hypofunction of osteoblasts induced by glucocorticoids (GCs) has been identified as a major contributing factor for GC-induced osteoporosis (GIO). However, the biological mechanism underlying the effect of GC in osteoblasts are not fully elucidated. Recent studies implicated an important role of phosphoinositide 3-kinase (PI3K)/protein kinase B(Akt) signaling pathway in the regulation of bone growth. We propose that the PI3K/Akt signaling may be implicated in the process of GC-induced osteogenic inhibition in osteoblasts. In this study, primary osteoblasts were used in vitro and in rats in vivo to evaluate the biological significance of the PI3K/Akt pathway in GC-induced bone loss. In vivo, dexamethasone (Dex)-treated rats had low bone mineral density and decreased expression levels of alkaline phosphatase (ALP), osteocalcin (OCN), and phosphorylated Akt (p-Akt) in bone tissue. In vitro study shows that Dex over the dose of 10-8 M remarkably inhibited cellular osteogenesis, as represented by decreased cell viability, lessened ALP activity, and suppressed osteogenic protein expressions including ALP and OCN. Meanwhile, a dramatic downregulation in the PI3K/Akt pathway phosphorylation was also observed in Dex-treated osteoblasts. These changes were marked rescued by treatment with a PI3K agonist 740Y-P. Moreover, downregulation of ALP and OCN expressions by LY294002 can mimic the suppressive effects of Dex. These data together reveal that the suppressed PI3K/Akt pathway is involved in the regulatory action of Dex on osteogenesis.


Assuntos
Anti-Inflamatórios/farmacologia , Dexametasona/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Feminino , Osteoblastos/citologia , Osteoblastos/metabolismo , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
5.
Opt Express ; 24(13): 13788-99, 2016 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-27410542

RESUMO

We present a theoretical analysis on optical spin-sensitive Zitterbewegung (ZB) in metamaterials. By developing some formulas about the dispersions and eigenstates of optical modes we show that spin-sensitive ZB can be obtained in a bianisotropic metamaterial with a proper coupling between the electric and magnetic responses. A close analogue of the developed analytical results with these of Dirac equation is proposed. Numerical simulation proves the existence of ZB on the refracted optical beam along a direction determined by the optical spin of incidence. Furthermore, we show that when the incident optical field is linearly polarized, although ZB on field intensity does not exist, the optical spin possesses an interesting spatial split and trembling phenomena. Significance of this investigation is discussed.

6.
Endocrine ; 82(2): 335-342, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37308773

RESUMO

BACKGROUND: Iodine is an essential element for the biosynthesis of thyroid-stimulating hormone (TSH). Both excessive and deficient iodine are major risk factors for thyroid diseases, including thyroid dysfunction, thyroid nodules, and thyroid autoimmunity (TAI). This study aimed to elucidate the relationship between iodine status and the prevalence of thyroid diseases through a national cross-sectional epidemiological survey in Jiangxi province (China). METHODS: This population-based, cross-sectional study enrolled 2636 Chinese local inhabitants who aged over 18 years old from April to August in 2015. Physical examination was performed and biochemical indices, urinary iodine concentration (UIC), and TSH level were measured. The Chi-square test, nonparametric test, and 4 multivariate logistic regression models adjusted for risk factors were applied to analysis. Spearman correlation coefficients were calculated to investigate the relationship between iodine intake level and the prevalence of thyroid diseases. RESULTS: The median UIC was 176.4 µg/L, and a significant difference was found in median UIC between men (182.45 µg/L) and women (169.25 µg/L) (P = 0.03). Among these study subjects, 14.4%, 44.5%, 26.1%, and 15.0% had deficient, adequate, more than adequate, and excessive iodine concentrations, respectively. The prevalence rates of hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, subclinical hypothyroidism, thyroid nodules, and TAI were 0.91%, 0.57%, 0.34% and 7.89%, 9.45%, and 12.7%, respectively. Significant differences were found in iodine status, waist circumstance, systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), TSH, thyroid nodules, and TAI between men and women (P < 0.05). Compared with those with adequate UIC, subjects with excessive UIC had higher prevalence rates of thyroid dysfunction (odds ratio (OR) = 1.74, 95% confidence interval (CI): 1.40-2.54) and thyroid nodules (OR = 3.33, 95%CI 1.32-8.42). In addition, subjects with deficient and excessive UIC were at the higher risk of TAI compared with those with adequate UIC (OR = 1.68, 95%CI: 1.19-2.60; OR = 1.52, 95%CI: 1.04-2.96, respectively). UIC was positively correlated with the prevalence rates of thyroid nodules (r = -0.44, P < 0.01) and TAI (r = -0.055, P < 0.01). On the contrary, UIC was negatively correlated with the risk of thyroid dysfunction (r = -0.24, P > 0.05). CONCLUSION: Adult inhabitants from Jiangxi province in the TIDE study were in the adequate iodine status. Excessive iodine status was noted as a risk factor for thyroid dysfunction and thyroid nodules. In addition, both iodine deficiency and excessive iodine were risk factors for TAI.


Assuntos
Hipertireoidismo , Hipotireoidismo , Iodo , Doenças da Glândula Tireoide , Nódulo da Glândula Tireoide , Masculino , Adulto , Humanos , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Nódulo da Glândula Tireoide/epidemiologia , Tiroxina , Prevalência , Doenças da Glândula Tireoide/epidemiologia , Doenças da Glândula Tireoide/induzido quimicamente , Hipotireoidismo/epidemiologia , Hipotireoidismo/induzido quimicamente , Tireotropina , China/epidemiologia
7.
Nat Commun ; 14(1): 2041, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-37041154

RESUMO

Six transmembrane epithelial antigen of the prostate 1 (STEAP1) is a cell surface antigen for therapeutic targeting in prostate cancer. Here, we report broad expression of STEAP1 relative to prostate-specific membrane antigen (PSMA) in lethal metastatic prostate cancers and the development of a STEAP1-directed chimeric antigen receptor (CAR) T cell therapy. STEAP1 CAR T cells demonstrate reactivity in low antigen density, antitumor activity across metastatic prostate cancer models, and safety in a human STEAP1 knock-in mouse model. STEAP1 antigen escape is a recurrent mechanism of treatment resistance and is associated with diminished tumor antigen processing and presentation. The application of tumor-localized interleukin-12 (IL-12) therapy in the form of a collagen binding domain (CBD)-IL-12 fusion protein combined with STEAP1 CAR T cell therapy enhances antitumor efficacy by remodeling the immunologically cold tumor microenvironment of prostate cancer and combating STEAP1 antigen escape through the engagement of host immunity and epitope spreading.


Assuntos
Neoplasias da Próstata , Receptores de Antígenos Quiméricos , Masculino , Camundongos , Animais , Humanos , Linfócitos T , Interleucina-12 , Linhagem Celular Tumoral , Neoplasias da Próstata/patologia , Imunoterapia , Microambiente Tumoral , Antígenos de Neoplasias , Oxirredutases
8.
Zhong Yao Cai ; 35(1): 70-4, 2012 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-22734415

RESUMO

OBJECTIVE: To analyse the chemical constituents of essential oils from Chrysanthemum indicum collected in Jinyun Mountains. METHODS: The essential oil was extracted by steam distillation and analyzed by GC-MS. RESULTS: The GC chromatogram of the essential oil had 92 peaks among which 69 were identified to be 66 compounds whose relative contents summed to account for 90. 07% of the total essential oil. CONCLUSION: It indicates Chrysanthemum indicum in Jinyun Mountains is good as medicine or for food. The place of origin has obvious influence on the chemical compostions of Chrysanthemum indicum's essential oil.


Assuntos
Chrysanthemum/química , Flores/química , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Anti-Inflamatórios não Esteroides/química , Cromatografia Gasosa-Espectrometria de Massas , Monoterpenos/análise , Sesquiterpenos/análise , Vapor
9.
Carbohydr Polym ; 254: 117410, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357896

RESUMO

Active and intelligent packaging films with multiple functions including antioxidant, antibacterial and colorimetric pH indicator properties were developed by incorporating Clitoria ternatea (CT) extract into gellan gum (G) film. G enhanced the stability of CT anthocyanins and allowed the anthocyanins to release from G film in a pH-responsive behavior. Heat-treated soy protein isolate (HSPI) was able to interact with G and CT anthocyanins through the formation of electrostatic forces and covalent bonds. G film blended with HSPI greatly reduced the swelling capacity of G/HSPI composite film and controlled the anthocyanins release at pH greater than 6.0. The physical and mechanical properties of G films such as hydrophobicity, water vapor permeability, swelling capacity and tensile strength were also significantly modified by addition of HSPI to G films. The smart films changed their color with the increase of total volatile basic nitrogen (TVBN) values during progressive spoilage of shrimp, revealing their potential application for monitoring seafood freshness.


Assuntos
Antocianinas/química , Clitoria/química , Embalagem de Alimentos/métodos , Qualidade dos Alimentos , Extratos Vegetais/química , Polissacarídeos Bacterianos/química , Materiais Inteligentes/química , Cor , Colorimetria/métodos , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Permeabilidade , Alimentos Marinhos , Proteínas de Soja/química , Eletricidade Estática , Vapor , Resistência à Tração
10.
Theranostics ; 10(22): 10001-10015, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32929330

RESUMO

Angiogenesis enhances cancer metastasis and progression, however, the roles of transcription regulation in angiogenesis are not fully defined. ZNF322A is an oncogenic zinc-finger transcription factor. Here, we demonstrate a new mechanism of Kras mutation-driven ZNF322A transcriptional activation and elucidate the interplay between ZNF322A and its upstream transcriptional regulators and downstream transcriptional targets in promoting neo-angiogenesis. Methods: Luciferase activity, RT-qPCR and ChIP-qPCR assays were used to examine transcription regulation in cell models. In vitro and in vivo angiogenesis assays were conducted. Immunohistochemistry, Kaplan-Meier method and multivariate Cox regression assays were performed to examine the clinical correlation in tumor specimens from lung cancer patients. Results: We validated that Yin Yang 1 (YY1) upregulated ZNF322A expression through targeting its promoter in the context of Kras mutation. Reconstitution experiments by knocking down YY1 under KrasG13V activation decreased KrasG13V-promoted cancer cell migration, proliferation and ZNF322A promoter activity. Knockdown of YY1 or ZNF322A attenuated angiogenesis in vitro and in vivo. Notably, we validated that ZNF322A upregulated the expression of sonic hedgehog (Shh) gene which encodes a secreted factor that activates pro-angiogenic responses in endothelial cells. Clinically, ZNF322A protein expression positively correlated with Shh and CD31, an endothelial cell marker, in 133 lung cancer patient samples determined using immunohistochemistry analysis. Notably, patients with concordantly high expression of ZNF322A, Shh and CD31 correlated with poor prognosis. Conclusions: These findings highlight the mechanism by which dysregulation of Kras/YY1/ZNF322/Shh transcriptional axis enhances neo-angiogenesis and cancer progression in lung cancer. Therapeutic strategies that target Kras/YY1/ZNF322A/Shh signaling axis may provide new insight on targeted therapy for lung cancer patients.


Assuntos
Proteínas Hedgehog/genética , Neoplasias Pulmonares/genética , Neovascularização Patológica/genética , Proteínas Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Fatores de Transcrição/genética , Transcrição Gênica/genética , Fator de Transcrição YY1/genética , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Progressão da Doença , Células Endoteliais/patologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Pulmão/patologia , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neovascularização Patológica/patologia , Oncogenes/genética , Regiões Promotoras Genéticas/genética , Transdução de Sinais/genética
11.
Cell Death Differ ; 26(7): 1283-1298, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30258097

RESUMO

ZNF322A, a C2H2 zinc finger transcription factor, is an oncoprotein in lung cancer. However, the transcription mechanisms of ZNF322A in lung cancer stem cell-like reprogramming remain elusive. By integrating our chromatin immunoprecipitation-sequencing and RNA-sequencing datasets, we identified and validated the transcriptional targets of ZNF322A, which were significantly enriched in tumorigenic functions and developmental processes. Indeed, overexpression of ZNF322A promoted self-renewal ability and increased stemness-related gene expressions in vitro and in vivo. Importantly, ZNF322A bound directly to c-Myc promoter and recruited histone deacetylase 3 to transcriptionally suppress c-Myc expression, which in turn increased mitochondrial oxidative phosphorylation and promoted cell motility, thus maintaining stem cell-like properties of lung cancer. Clinically, ZNF322AHigh/c-MycLow expression profile was revealed as an independent indicator of poor prognosis in lung cancer patients. Our study provides the first evidence that ZNF322A-centered transcriptome promotes lung tumorigenesis and ZNF322A acts as a transcription suppressor of c-Myc to maintain lung cancer stem cell-like properties by shifting metabolism towards oxidative phosphorylation.


Assuntos
Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Células-Tronco Neoplásicas/metabolismo , Proteínas Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Células A549 , Humanos , Neoplasias Pulmonares/metabolismo , Células-Tronco Neoplásicas/patologia , Proteínas Oncogênicas/genética , Fosforilação , Proteínas Proto-Oncogênicas c-myc/deficiência , Fatores de Transcrição/genética , Células Tumorais Cultivadas
12.
Sci Bull (Beijing) ; 64(12): 808-813, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-36659670

RESUMO

We demonstrate that asymmetric acoustic wave transmission in a waveguide can be achieved via gradient index metamaterials (GIMs). We theoretically prove that the acoustic wave can be efficiently converted to surface waves (SWs) via GIMs. The GIMs in a waveguide can allow the transmission of acoustic waves in one direction but block them in the other direction. This theory is validated by experiments. Our findings may provide new applications in various scenarios such as high-efficiency acoustic couplers and noise control.

13.
ACS Appl Mater Interfaces ; 11(18): 17050-17055, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-30977627

RESUMO

Fabricating materials with customized characteristics for both electromagnetic (EM) and acoustic waves remain a significant challenge using the current technology, since the demand of multiphysical manipulation requires a variety of material parameters that are hard to satisfy in nature. However, the emergence of artificially structured materials provides a new degree of freedom to tailor the wave-matter interactions in dual physical domains at the subwavelength scale. Here, a bifunctional digital coding metamaterial (MM) is proposed to engineer the propagation behaviors of EM and acoustic waves simultaneously and independently. Four kinds of rigid pillars with various material properties are employed to serve as 1-bit reflection-type digital meta-atoms with antiphase responses in both frequency spectra, thus offering the opportunities for independent field control as desired. The MM demonstrates excellent performance of scattering manipulations from 5700 to 8000 Hz in the acoustic region and 5.80-6.15 GHz in the microwave region. The bifunctional MM is verified through full-wave simulations and experimental measurements with good agreement, which stands out as a powerful tool for related applications in the future.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA