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1.
Theor Appl Genet ; 137(3): 51, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38369666

RESUMO

KEY MESSAGE: ClLOX, is located on chromosome 2 and encodes a lipoxygenase gene, which induced watermelon powdery mildew resistance by inhibiting pathogen spread. Powdery mildew is one of the most severe fungal diseases reducing yield and quality of watermelon (Citrullus lanatus L.) and other cucurbit crops. Genes responsible for powdery mildew resistance in watermelon are highly valuable. In this study, we first identified the QTL pm-lox for powdery mildew resistance in watermelon, located within a 0.93 Mb interval of chromosome 2, via XP-GWAS method using two F2 populations. The F2:3 families from one of the F2 populations were then used for fine-mapping the pm-lox locus into a 9,883 bp physical region between 29,581,906 and 29,591,789, containing only two annotated genes. Of these, only ClG42_02g0161300 showed a significant differential expression between the resistant and susceptible lines after powdery mildew inoculation based on RNA sequencing (RNA-seq) and qRT-PCR analysis, and is designated ClLOX. Derived Cleaved Amplified Polymorphic Sequence (dCAPs) markers were developed and validated. In addition, our tests showed that the resistance was anti-spread rather than anti-infection of the pathogen. This study identified a new resistance gene (ClLOX), provided insights into the mechanism of powdery mildew resistance, and developed a molecular marker for watermelon breeding.


Assuntos
Ascomicetos , Citrullus , Humanos , Mapeamento Cromossômico/métodos , Resistência à Doença/genética , Citrullus/genética , Citrullus/microbiologia , Ascomicetos/genética , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/microbiologia
2.
Mol Ther Nucleic Acids ; 31: 68-77, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36618267

RESUMO

Angiopoietin-like protein 3 (ANGPTL3) is an important regulator of lipoproteins by inhibiting both lipoprotein and endothelial lipases. It has been intensively investigated as a drug target for the treatment of dyslipidemia. In the present study, a modified small interfering RNA (siRNA) conjugated with GalNAc ANGsiR10 was characterized by in vivo and in vitro studies for its effect on ANGPTL3 silencing, the reduction of plasma triglycerides (TGs), and cholesterol levels in disease models. The results showed that ANGsiR10 displayed a significant and long-lasting efficacy in reducing blood TG and cholesterol levels in both mice and monkeys. Remarkably, the maximal reductions of plasma TG levels in the hApoC3-Tg mice, a model with high TG levels, and the spontaneous dyslipidemia model of rhesus monkey were 96.3% and 67.7%, respectively, after a single dose of ANGsiR10, with long-lasting effects up to 15 weeks. The cholesterol levels were also reduced in response to treatment, especially the non-HDL-c level, without altering the ApoA/ApoB ratio. This study showed that ANGsiR10 is effective in treating dyslipidemia and is worth further development.

3.
BMC Pregnancy Childbirth ; 22(1): 928, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36496359

RESUMO

BACKGROUND: Previous studies have shown that the incidence of ectopic pregnancy (EP) is increasing in China. It is unclear, however, whether the incidence of EP has changed after the implementation of the universal two-child policy in the context of China's aging population and declining fertility rate. METHODS: Data concerning EP from January 2011 to December 2020 were collected from the hospital's electronic medical records, which included the annual number of delivery, caesarean section rate, ectopic pregnancies, treatment of tubal pregnancy, and average costs and length of hospitalization. Trends of the EP incidence were analysed and annual percentage change (APC) was calculated using connected point regression analyses. RESULTS: A total of 9499 cases of EP were collected, among which caesarean scar pregnancy (CSP) accounts for the second highest (6.73%). The EP per 100 deliveries revealed a downward trend, from 7.60% in 2011 to 4.28% in 2020 with an APC of -1.87 (P < 0.05). The maternal age was increased, especially after the implementation of the universal two-child policy. The constituent ratio for the advanced maternal age (≥ 35) and the caesarean section rate, but not the CSP, were also increased. Laparoscopic salpingectomy was the main surgical method, whereas the adoption of laparotomy and laparoscopic salpingostomy was decreasing year by year. CONCLUSIONS: Although no obvious effect of the two-child policy on EP has been observed under the conditions of this study, the change in EP especially in advanced-age women after the policy implementation needs further evaluation. A decreased caesarean section rate, in primipara is beneficial to reducing the CSP.


Assuntos
Cesárea , Gravidez Ectópica , Feminino , Gravidez , Humanos , Idoso , Estudos Retrospectivos , Fertilidade , Recidiva , Gravidez Ectópica/epidemiologia , Gravidez Ectópica/etiologia , Gravidez Ectópica/terapia
4.
Appl Opt ; 61(11): 3174-3181, 2022 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-35471295

RESUMO

A rotation angle measurement method based on self-mixing interference (SMI) of a fiber laser is proposed. The rotation angle can be calculated indirectly by the displacement measured by SMI. In the experiment, a linear cavity fiber laser with simple structure and high flexibility is used as the optical source for measuring the deflection angle. To improve the measurement accuracy, the SMI signal is filtered by the variational mode decomposition (VMD) algorithm. The filtered SMI signal is normalized by Hilbert transform. The even-power algorithm is used to subdivide the interference fringes, so as to improve the measurement resolution. The experimental result shows that the measurement error of angular shift is less than 1% in the range of 10°.

5.
Mater Sci Eng C Mater Biol Appl ; 127: 112237, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225877

RESUMO

For developing electrochemical plant sensors, in-situ detection of hormone levels in living plants is worth attempting. A microneedle array sensor based on Au@SnO2-vertical graphene (VG)/Ta microelectrodes was constructed for analyzing abscisic acid (ABA) in plants. Graphene was vertically grown on Ta wires with a diameter of 0.6 mm by direct current arc plasma jet chemical vapor deposition with SnO2 as the Au catalyst carrier. These VG nanosheets were embedded with core-shell Au@SnO2 nanoparticles, and the formation mechanism of the sensing layer was investigated. Three Au@SnO2-VG microelectrodes, one Ti wire, and one Pt wire were packed into a microneedle array sensor with a three-electrode system. ABA was then quantitatively detected by direct electrocatalytic oxidation, which involves the synergistic catalytic effects of the abundant catalytic active sites of the Au@SnO2 nanoparticles and the excellent conductivity of the VG nanosheets. The microneedle array sensor responds to ABA in the pH range 4-7, the response concentration range was 0.012 (or 0.024)-495.2 µM, and the detection limit varied between 0.002 and 0.005 µM. The small size, wide pH range, low detection limit, and wide linear concentration range allow the microneedle array sensor to be inserted into plants for in-situ detection of ABA.


Assuntos
Grafite , Nanopartículas , Ácido Abscísico , Catálise , Técnicas Eletroquímicas
6.
Aging (Albany NY) ; 12(17): 16963-16980, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32920551

RESUMO

BACKGROUND: PGC-1α and ERRα are closely related to tumor formation and progression. However, the mechanism underlying the involvement of PGC-1α/ERRα in regulating invasion and migration in endometrial cancer remains to be explored. RESULTS: Elevated levels of PGC-1α and ERRα were associated with advanced myometrial invasion, and PGC-1α and Vimentin expression was related to the depth of myometrial invasion in premenopausal endometrial cancer. Silencing of PGC-1α reduced ERRα activation and inhibited epithelial-mesenchymal-transition phenotypes, resulting in significant inhibition of invasion and migration. Overexpression of ERRα led to enhanced PGC-1α expression and increased activity of TFEB, promoting epithelial-mesenchymal-transition in endometrial cancer cells. CONCLUSIONS: PGC-1α and ERRα induce the epithelial-mesenchymal-transition therefore invasion and migration in endometrial cancer, and may be novel biomarkers to predict the risk of advanced myometrial invasion. METHODS: PGC-1α, ERRα, and vimentin expression was analyzed in tissue microarrays using immunohistochemistry. PGC-1α and ERRα expression in endometrial cancer cell lines was investigated using quantitative PCR and western blotting analyses after infection with lentivirus-mediated small interfering RNA (siRNA) targeting PGC-1α (siRNA-PGC-1α) or overexpressing ERRα. E-cadherin and vimentin levels were determined using western blotting and cell immunouorescence analyses. Cell migration and invasiveness were evaluated using scratch and trans-well chamber assays.

7.
Sensors (Basel) ; 20(9)2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32365704

RESUMO

An analytical model for analyzing multi-channel intracavity spectroscopy technology (ICST) is established based on rate equations of Er-doped fiber laser. With the consideration of the amplified spontaneous emission, how the mode competition influences the iterative process for a stable output is analyzed. From the perspective of iterative times, the sensitivity-enhanced mechanism of the ICST is explained. Moreover, the theoretical modeling is employed to analyze the role that the mode-competition effect plays in switching the sensing channel automatically. It is demonstrated that, owing to the mode-competition effect in the laser cavity, the modulation of the cavity loss can be used to tune the sensing channel automatically. Furthermore, our proposed theoretical modeling is verified using a multi-channel ICST sensing system. It is indicated that the calculated estimates agree well with those data from the experimental absorption spectra. The principle will play a significant role in realizing the multiplexing of ICST.

8.
Plant Cell Environ ; 43(6): 1394-1403, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32092164

RESUMO

Solidago canadensis, originating from the temperate region of North America, has expanded southward to subtropical regions through polyploidization. Here we investigated whether freezing tolerance of S. canadensis was weakened during expansion. Measurement of the temperature causing 50% ruptured cells (LT50 ) in 35 S. canadensis populations revealed ploidy-related differentiation in freezing tolerance. Freezing tolerance was found to decrease with increasing ploidy. The polyploid populations of S. canadensis had lower ScICE1 gene expression levels but more ScICE1 gene copies than the diploids. Furthermore, more DNA methylation sites in the ScICE1 gene promoter were detected in the polyploids than in the diploids. The results suggest that promoter methylation represses the expression of multi-copy ScICE1 genes, leading to weaker freezing tolerance in polyploid S. canadensis compared to the diploids. The study provides empirical evidence that DNA methylation regulates expression of the gene copies and supports polyploidization-driven adaptation to new environments.


Assuntos
Adaptação Fisiológica , Congelamento , Poliploidia , Solidago/genética , Solidago/fisiologia , Adaptação Fisiológica/genética , Metilação de DNA/genética , Dosagem de Genes , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética
11.
Appl Opt ; 58(25): 6770-6774, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31503644

RESUMO

Tunable optical wavelength filters are indispensable components in optical communication systems. In this paper, an ultra-narrowband tunable filter inscribed in lithium niobate (LN) wafer is designed. Two sections of Bragg grating and a pair of electrodes are fabricated in the LN waveguide. The operation wavelength could be tuned by adjusting the electric voltage applied on the electrode pair owing to the electro-optic effect of LN crystal. Simulation results indicate that the filtering bandwidth of the proposed phase-shifted Bragg grating is determined by grating lengths no longer than 1 pm. The tuning sensitivity is dependent on the distance between the two gratings. In addition, the proposed structure overcomes the difficulty in controlling the phase shift of the grating pair, ensuring its potential applications in optical sensing systems.

12.
J Cancer Res Ther ; 14(7): 1463-1468, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30589024

RESUMO

Ultrasonography, the preferred imaging modality for breast diseases, has merits such as absence of radiation, high diagnostic accuracy, and convenience for follow-up, thus playing an important role in clinical diagnosis and management. The American College of Radiology (ACR) proposed Breast Imaging-Reporting and Data System (BI-RADS ) and has updated for several times. Gradually, the BI-RADS has been accepted and adopted by ultrasound physicians at all levels of hospitals in China, and it has played a certain role in improving the diagnostic level of breast ultrasound in China. In order to standardize breast ultrasound application and raise the status of ultrasound in clinical decision-making of breast diseases, based on the latest edition of ACR BI-RADS Atlas 2013, the committee has reached the "Expert Consensus on Clinical Frequently Asked Questions in Breast Ultrasonography"on a number of controversial Frequently Asked Questions (FAQs) in clinical practice (hereafter referred to as "Consensus"), and will be dedicated to updating the contents of the "Consensus", through further experience in clinical practice and the advent of new information from further studies. This consensus is only for reference purposes for medical personnel, and the processes outlined are not mandatory by law.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Ultrassonografia , Neoplasias da Mama/patologia , Consenso , Prova Pericial , Feminino , Humanos , Ultrassonografia/métodos
13.
Accid Anal Prev ; 117: 250-261, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29727862

RESUMO

One of the proactive approaches in reducing traffic crashes is to identify hazardous traffic conditions that may lead to a traffic crash, known as real-time crash prediction. Threshold selection is one of the essential steps of real-time crash prediction. And it provides the cut-off point for the posterior probability which is used to separate potential crash warnings against normal traffic conditions, after the outcome of the probability of a crash occurring given a specific traffic condition on the basis of crash risk evaluation models. There is however a dearth of research that focuses on how to effectively determine an optimal threshold. And only when discussing the predictive performance of the models, a few studies utilized subjective methods to choose the threshold. The subjective methods cannot automatically identify the optimal thresholds in different traffic and weather conditions in real application. Thus, a theoretical method to select the threshold value is necessary for the sake of avoiding subjective judgments. The purpose of this study is to provide a theoretical method for automatically identifying the optimal threshold. Considering the random effects of variable factors across all roadway segments, the mixed logit model was utilized to develop the crash risk evaluation model and further evaluate the crash risk. Cross-entropy, between-class variance and other theories were employed and investigated to empirically identify the optimal threshold. And K-fold cross-validation was used to validate the performance of proposed threshold selection methods with the help of several evaluation criteria. The results indicate that (i) the mixed logit model can obtain a good performance; (ii) the classification performance of the threshold selected by the minimum cross-entropy method outperforms the other methods according to the criteria. This method can be well-behaved to automatically identify thresholds in crash prediction, by minimizing the cross entropy between the original dataset with continuous probability of a crash occurring and the binarized dataset after using the thresholds to separate potential crash warnings against normal traffic conditions.


Assuntos
Acidentes de Trânsito , Condução de Veículo , Modelos Teóricos , Medição de Risco/métodos , Planejamento Ambiental , Humanos , Modelos Logísticos , Veículos Automotores , Probabilidade , Fatores de Risco , Tempo (Meteorologia)
14.
Oncotarget ; 9(16): 12682-12694, 2018 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-29560101

RESUMO

The effects of specific and non-specific regulation of matriptase on endometrial cancer cells in vitro were investigated. Messenger ribonucleic acid (mRNA) and protein expression of matriptase and hepatocyte growth factor activator inhibitor-1 (HAI-1) in RL-952, HEC-1A, and HEC-1B endometrial cancer cells were detected by real-time quantitative PCR (RT-qPCR) and western blot. The cells were infected with lentivirus-mediated small-interfering RNA (siRNA) targeted on matriptase (MA-siRNA) or treated with different cisplatin (DDP) concentrations. After treatment, invasion, migration, and cellular apoptosis were analyzed. Matriptase mRNA and protein expression significantly decreased to 80% after infection with MA-siRNA (P < 0.01), and scratch and trans-well chamber assays showed significant inhibition of invasiveness and metastasis. Upon incubation with cisplatin at concentrations higher than the therapeutic dose for 24 h, the expressions of matriptase and HAI-1 significantly decreased (P < 0.001). Moreover, the invasiveness, metastasis, and survival rate of HEC-1A and RL-952 endometrial cancer cells were significantly decreased (P < 0.001) due to the down-regulation of matriptase and HAI-1 upon increasing cisplatin concentration. However, a slight increase in matriptase and HAI-1 expression was observed in cells treated with low cisplatin concentration (P = 0.01). Moreover, matriptase expression was associated with metastasis and invasiveness. Down-regulation of matriptase by specific Ma-SiRNA or non-specific cisplatin in matriptase/HAI-1-positive endometrial cancer cells showed promising therapeutic features.

15.
Mol Med Rep ; 14(2): 1465-74, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27356668

RESUMO

Tumor invasion and metastasis are complex biological processes. Matriptase and its endogenous inhibitor, hepatocyte growth factor activator inhibitor­1 (HAI­1) are involved in invasion and metastasis. To evaluate the ratio of matriptase/HAI­1 and their potential therapeutic value in ovarian cancer, HO­8910 human ovarian cancer cells and the homologous high­metastatic HO­8910PM cells were used as in vitro cellular models ovarian cancer. The invasive and metastatic abilities, and the expression of matriptase and HAI­1 in these cells were detected using scratch assays, Transwell chamber assays, reverse transcription­quantitative polymerase chain reaction, western blotting and fluorescent immunocytochemistry. Following infection with lentivirus­mediated matriptase­targeting small interfering RNA (siRNA), cell cycle progression and apoptosis were also analyzed. The migration distance and number of invading HO­8910PM cells were significantly increased compared with HO­8910 cells. HO­8910PM cells exhibited a significantly higher ratio of matriptase/HAI­1 mRNA levels compared with HO­8910 cells (0.51 vs. 0.24, ~2.2 fold increase). Compared with HO­8910 cells, the matriptase mRNA level was increased by ~3.6 fold in HO­8910PM cells, whereas the HAI­1 mRNA level was increased by ~1.7 fold. Similar increases in protein expression levels were also observed in HO­8910PM cells compared with HO­8910 cells. Migration and invasiveness were positively correlated with matriptase expression level (r=0.994, P<0.01) and the ratio of matriptase/HAI­1 (r=0.929, P<0.01). Downregulation of matriptase using siRNA resulted in inhibition of the invasive and metastatic abilities of HO­8910PM cells, cell cycle arrest in the G0/G1 phase and increased apoptosis. The present study demonstrated that ovarian cancer cell metastasis and invasion were more dependent on upregulation of matriptase levels than downregulation of HAI­1. Matriptase may be a potential adjuvant therapeutic target for inhibiting ovarian cancer invasion and metastasis.


Assuntos
Neoplasias Ovarianas/metabolismo , Proteínas Secretadas Inibidoras de Proteinases/metabolismo , Serina Endopeptidases/metabolismo , Apoptose/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Feminino , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Transporte Proteico , Proteínas Secretadas Inibidoras de Proteinases/genética , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Serina Endopeptidases/genética
16.
Sci Rep ; 5: 13764, 2015 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-26374393

RESUMO

In order to investigate the influences of Lewis metals on acidic properties and catalytic activities, a series of Keggin heteropolyacid (HPA) catalysts, HnPW11MO39 (M = Ti(IV), Cu(II), Al(III), Sn(IV), Fe(III), Cr(III), Zr(IV) and Zn(II); for Ti and Zr, the number of oxygen is 40), were prepared and applied in the esterification and transesterification reactions. Only those cations with moderate Lewis acidity had a higher impact. Ti Substituted HPA, H5PW11TiO40, posse lower acid content compared with Ti(x)H(3-4x)PW12O40 (Ti partial exchanged protons in saturated H3PW12O40), which demonstrated that the Lewis metal as an addenda atom (H5PW11TiO40) was less efficient than those as counter cations (Ti(x)H(3-4x)PW12O40). On the other hand, the highest conversion reached 92.2% in transesterification and 97.4% in esterification. Meanwhile, a good result was achieved by H5PW11TiO40 in which the total selectivity of DAG and TGA was 96.7%. In addition, calcination treatment to H5PW11TiO40 make it insoluble in water which resulted in a heterogeneous catalyst feasible for reuse.

17.
Kaohsiung J Med Sci ; 31(2): 96-101, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25645988

RESUMO

This study aimed to investigate the clinical application value of the 5-fluorouracil (5-FU) sustained-release particles implanted along the cardiac tangent direction into malignant pericardial effusion (MPCE). A total of 81 MPCE patients underwent pericardiocentesis, and were implanted with 5-FU sustained-release particles into the pericardial cavity under ultrasound guidance. The puncturing path was along the cardiac tangent direction. Ultrasound examinations were performed every week, and the efficacy was evaluated 4 weeks after treatment. The 45 patients who were treated with pericardial catheter drainage and simultaneous intracavitary chemotherapy were used as the control group. The success rate of pericardiocentesis was 100%. Ultrasound reviews performed 4 weeks after treatment showed that 71 cases achieved complete remission and eight cases achieved partial remission, while treatment was completely ineffective in two cases. The total remission rate was 97.53%, which was significantly higher than that of the control group (77.78%, p < 0.01). The implantation of 5-FU sustained-release particles along the cardiac tangent direction was safe, and demonstrated good efficacy and fewer adverse reactions. Thus, this method could be ideal for the treatment of MPCE.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Preparações de Ação Retardada/administração & dosagem , Fluoruracila/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Derrame Pericárdico/tratamento farmacológico , Feminino , Humanos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Derrame Pericárdico/etiologia , Resultado do Tratamento
18.
Circulation ; 124(1): 77-86, 2011 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-21690491

RESUMO

BACKGROUND: The metabolic syndrome (MetS) is a constellation of clinical features that include central obesity, hypertension, atherogenic dyslipidemia, and insulin resistance. However, the concept remains controversial; it has been debated whether MetS represents nothing more than simultaneous co-occurrence of individual risk factors or whether there are common shared pathophysiological mechanisms that link the individual components. METHODS AND RESULTS: To investigate the emergence of metabolic and cardiovascular components during the development of MetS, we identified MetS-predisposed animals (n=35) in a large population of rhesus macaques (Macaca mulatta, 12.7±2.9 years old, n=408), acclimated them to standardized conditions, and monitored the progression of individual component features over 18 months. In 18 MetS animals with recently developed fasting hyperinsulinemia, central obesity, hypertension, and atherogenic dyslipidemia, we found that individual metabolic and cardiovascular components track together during the transition from pre-MetS to onset of MetS; MetS was associated with a 60% impairment of flow-mediated dilation, establishing the mechanistic link with vascular dysfunction. Pioglitazone treatment (3 mg/kg body weight/d for 6 weeks), a peroxisome proliferator-activated receptor γ agonist, reversibly improved atherogenic dyslipidemia and insulin resistance and fully restored flow-mediated dilation with persistent benefits. CONCLUSIONS: Coemergence of metabolic and cardiovascular components during MetS progression and complete normalization of vascular dysfunction with peroxisome proliferator-activated receptor γ agonists suggest shared underlying mechanisms rather than separate processes, arguing for the benefit of early intervention of MetS components. Predictive nonhuman primate (NHP) models of MetS should be highly valuable in mechanistic and translational studies on the pathogenesis of MetS in relation to cardiovascular disease and diabetes mellitus.


Assuntos
Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/fisiopatologia , Hipoglicemiantes/farmacologia , Síndrome Metabólica/fisiopatologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Tiazolidinedionas/farmacologia , Animais , Modelos Animais de Doenças , Progressão da Doença , Dislipidemias/fisiopatologia , Hiperinsulinismo/fisiopatologia , Hipertensão/fisiopatologia , Resistência à Insulina/fisiologia , Macaca mulatta , Obesidade Abdominal/fisiopatologia , Pioglitazona , Fluxo Sanguíneo Regional/fisiologia
19.
Opt Express ; 17(5): 3115-23, 2009 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-19259147

RESUMO

We propose and experimentally demonstrate light beam coupling between a single-mode fiber (SMF) and a highly nonlinear photonic crystal fiber (HN-PCF) based on the fused biconical tapering (FBT) technique. In our experiment, a standard SMF is pre-tapered to match its propagation constant to that of a HN-PCF. In order to remove the condensation in the air holes, the temperature is increased gradually to preheat the fibers. An appropriate level of hydrogen flow is administered to avoid the air-hole collapse. As a result, coupling ratio exceeding 90% between the SMF and HN-PCF is achieved. This technique avoids back Fresnel reflection, mode-field diameter (MFD) mismatch and fiber-core misalignment, bubble generation and air-hole collapse in the interface fusion splice.

20.
Appl Opt ; 46(31): 7771-5, 2007 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17973022

RESUMO

We numerically investigated the impacts of the imperfect geometry structure on the nonlinear and chromatic dispersion properties of a microstructure fiber (MF). The statistical results show that the imperfect geometry structure degrades the high nonlinearity and fluctuates the chromatic dispersion in a MF. Moreover, the smaller air holes and the larger pitch are more likely to maintain the properties of nonlinearity and chromatic dispersion. Finally, the nonlinearity and chromatic dispersion are more insensitive to air-hole nonuniformity than to air-hole disorder. All of these will provide references for designing and fabricating MF.

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