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1.
Opt Express ; 27(21): 29770-29780, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31684234

RESUMO

We report on experimental generation and evolution of circumstance-susceptible, narrow-bandwidth, h-shaped pulse in a thulium-doped fiber (TDF) laser. With typical mode-locking technique based on nonlinear amplifying loop mirror, a type of h-shaped pulse is generated in a net normal dispersion regime for the first time to our best knowledge. Different from pulses with similar profiles achieved in typical anomalous dispersion regime, the h-shaped pulse here exhibits extremely narrow spectral bandwidth and meanwhile becomes highly circumstance-susceptible. Not alike the well-preserved h-shaped profile with anomalous dispersion, here the h-shaped pulse can easily evolve into various other pulse patterns with circumstance variations, including peak-depressed profiles, burst-like emission, multiple h-shaped pulses, and even some highly complex temporal cases. Despite that, the h-shaped pulse broadens as the pump power increasing, being a typical pump-related characteristic dominated by the peak-power-clamping effect. Moreover, it is observed that the h-shaped pulse profile can be re-shaped by incorporating a piece of unpumped TDF into the cavity, i.e., introducing some reabsorption. Our results substantiate the experimental revelation of such a type of particular-profile pulse in the normal dispersion regime, demonstrating some new evolution features facilitated by the dispersion-relevant circumstance-susceptibility.

2.
Toxicon ; 165: 62-68, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31047932

RESUMO

Staphylococcal enterotoxin B (SEB) is an important enterotoxin which is a major reason for food poisoning and a potential biologic agent. Hence, rapid and accurate detection is very important. An amplified luminescent proximity homogeneous assay (AlphaLISA) for SEB detection was established here. Its performance was evaluated on mock specimen and culture supernatant. Its free from the effect of protein A was compared with ELISA. Results showed that the linear range for SEB detection was 25 pg/mL to 25 ng/mL. The detection limitation is 25 pg/mL in buffer and 50 pg/mL in specimen respectively. There was no cross-reaction with other classical SEs or botulinum toxin. AlphaLISA was also tolerant to the matrix of sample and showed good repeatability. The inter-assay coefficient of variation (CV) and intra-assay CV were<10% for buffer and mock specimens, respectively. Besides AlphaLISA detection was free of the interference of protein A (which is the obstacle for immune-based detection of SEs in Staphylococcus aureus culture supernatants): this feature is very important for food-poisoning confirmation caused by SEB contamination. These data suggest that the AlphaLISA established here is well suited for SEB detection in food samples and S. aureus culture supernatants.


Assuntos
Enterotoxinas/análise , Imunoensaio/métodos , Enterotoxinas/química , Contaminação de Alimentos/análise , Limite de Detecção , Proteína Estafilocócica A/química
3.
Opt Lett ; 44(10): 2414-2417, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31090694

RESUMO

We report on dissipative soliton resonance (DSR) and its transformation into a type of burst-like emission in a holmium-doped fiber (HDF) laser in the large normal dispersion regime. A nonlinear amplifying loop mirror incorporating ∼118 m large normal dispersion fiber acts as an artificial saturable absorber. To the best of our knowledge, the HDF laser has the largest net normal dispersion so far. As the pump power is increased from ∼1.72 W to ∼4.80 W, the produced single pulse linearly broadens from ∼6.7 ns to ∼68.0 ns, while the output pulse peak power is clamped around ∼180.5 mW due to the peak-power-clamping effect with DSR. The sharp spectral peak indicates that DSR is realized with a large normal dispersion. With further manipulation of the polarization state, DSR can evolve into a type of burst-like emission. It is further revealed that this burst-like emission could be caused by a type of peak-power-depressing effect, which results from the competition between DSR and soliton formation.

4.
ACS Nano ; 12(9): 9381-9389, 2018 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-30183252

RESUMO

Mechanosensitive electronics aims at replicating the multifunctions of human skin to realize quantitative conversion of external stimuli into electronic signals and provide corresponding feedback instructions. Here, we report a mechanosensation-active matrix based on a direct-contact tribotronic planar graphene transistor array. Ion gel is utilized as both the dielectric in the graphene transistor and the friction layer for triboelectric potential coupling to achieve highly efficient gating and sensation properties. Different contact distances between the ion gel and other friction materials produce different triboelectric potentials, which are directly coupled to the graphene channel and lead to different output signals through modulating the Fermi level of graphene. Based on this mechanism, the tribotronic graphene transistor is capable of sensing approaching distances, recognizing the category of different materials, and even distinguishing voices. It possesses excellent sensing properties, including high sensitivity (0.16 mm-1), fast response time (∼15 ms), and excellent durability (over 1000 cycles). Furthermore, the fabricated mechanosensation-active matrix is demonstrated to sense spatial contact distances and visualize a 2D color mapping of the target object. The tribotronic active matrix with ion gel as dielectric/friction layer provides a route for efficient and low-power-consuming mechanosensation in a noninvasive fashion. It is of great significance in multifunction sensory systems, wearable human-machine interactive interfaces, artificial electronic skin, and future telemedicine for patient surveillance.

5.
Adv Mater ; 30(16): e1800066, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29534314

RESUMO

Smart skin is expected to be stretchable and tactile for bionic robots as the medium with the ambient environment. Here, a stretchable triboelectric-photonic smart skin (STPS) is reported that enables multidimensional tactile and gesture sensing for a robotic hand. With a grating-structured metal film as the bioinspired skin stripe, the STPS exhibits a tunable aggregation-induced emission in a lateral tensile range of 0-160%. Moreover, the STPS can be used as a triboelectric nanogenerator for vertical pressure sensing with a maximum sensitivity of 34 mV Pa-1 . The pressure sensing characteristics can remain stable in different stretching conditions, which demonstrates a synchronous and independent sensing property for external stimuli with great durability. By integrating on a robotic hand as a conformal covering, the STPS shows multidimensional mechanical sensing abilities for external touch and different gestures with joints bending. This work has first demonstrated a triboelectric-photonic coupled multifunctional sensing terminal, which may have great applications in human-machine interaction, soft robots, and artificial intelligence.

6.
Opt Lett ; 43(2): 247-250, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29328251

RESUMO

We report on a type of 2 µm h-shaped pulse generation in a thulium-holmium-doped fiber laser and experimentally investigate its cavity birefringence and pump power dependences. An asymmetric nonlinear optical loop mirror is employed as an artificial saturable absorber, which incorporates ∼52.7 m dispersion-shifted fiber and ∼3.8 m ultra-high numerical aperture fiber to enhance the nonlinearity. The h-shaped pulse shows both a polarization state (PS) and pump power related evolutions, even when randomly weak birefringence fibers are employed. By further incorporating different lengths of high birefringence polarization-maintaining fiber (PMF), i.e., introducing different amounts of linear cavity birefringence, much larger pulse tuning ranges can be realized. In particular, when the PMF is lengthened to ∼2.3 m through manipulating the PS, the achieved longest pulse duration of ∼318.14 ns can almost cover the whole repetition period of ∼323.96 ns, corresponding to a pulse duty circle of ∼98.2%, the largest ever reported from a fiber laser, to the best of our knowledge. We demonstrate the related characteristics in detail.

7.
Zhongguo Zhen Jiu ; 37(3): 317-320, 2017 Mar 12.
Artigo em Chinês | MEDLINE | ID: mdl-29231442

RESUMO

Acupuncture with Point Location is one of the mandatory examinations for the Diplomate of Oriental Medicine (Dipl.OM.) or Acupuncture (Dipl. Ac.) by American National Certification Commission for Acupuncture and Oriental Medicine (NCCAOM). In reference to NCCAOM Certification Handbook, Acupuncture with Point Location Expanded Content Outline, and Study Guide for Diplomates in Acupuncture Certification, the authors introduced the examination pattern and examination-related contents including such aspects as safety and professional responsibilities, treatment plan, and point location and discussed additionally the enlightening effects on acupuncture practice and examination in universities and international associations of Chinese medicine in our country.


Assuntos
Pontos de Acupuntura , Acupuntura , Certificação , Competência Clínica , Medicina Tradicional do Leste Asiático , Terapia por Acupuntura , Meridianos , Estados Unidos
8.
ACS Nano ; 11(11): 11566-11573, 2017 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-29099579

RESUMO

Flexible electronics has attracted enormous interest in wearable electronics and human-machine interfacing. Here, a flexible organic tribotronic transistor (FOTT) without a top gate electrode has been demonstrated. The FOTT is fabricated on a flexible polyethylene terephthalate film using the p-type pentacene and poly(methyl methacrylate)/Cytop composites as the conductive channel and dielectric layer, respectively. The charge carriers can be modulated by the contact electrification between the dielectric layer and a mobile triboelectric layer. Based on the fabricated FOTT, pressure and magnetic sensors have been developed, respectively, that exhibit great sensitivity, fast response time, and excellent stability. The FOTT in this simple structure shows bright potentials of tribotronics in human-machine interaction, electronic skins, wearable electronics, intelligent sensing, and so on.

9.
Opt Express ; 24(11): 12072-81, 2016 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-27410128

RESUMO

In this paper, we first achieve nanosecond-scale dissipative soliton resonance (DSR) generation in a thulium-doped double-clad fiber (TDF) laser with all-anomalous-dispersion regime, and also first scale the average power up to 100.4 W by employing only two stage TDF amplifiers, corresponding to gains of 19.3 and 14.4 dB, respectively. It is noted that both the fiber laser oscillator and the amplification system employ double-clad fiber as the gain medium for utilizing the advantages in high-gain-availability, high-power-handling and good-mode-quality-maintaining. DSR mode-locking of the TDF oscillator is realized by using a nonlinear optical loop mirror (NOLM), which exhibits all-fiber-format, high nonlinear and passive saturable absorption properties. The TDF oscillator can deliver rectangular-shape pulses with duration ranging from ~3.74 to ~72.19 ns while maintaining a nearly equal output peak power level of ~0.56 W, namely peak power clamping (PPC) effect. Comparatively, the two stage amplifiers can scale the seeding pulses to similar average power levels, but to dramatically different peak powers ranging from ~0.94 to ~18.1 kW depending on the durations. Our TDF master-oscillator-power-amplifier (MOPA) system can provide a high power 2-µm band all-fiber-format laser source both tunable in pulse duration and peak power.

10.
ACS Appl Mater Interfaces ; 8(11): 6898-904, 2016 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-26937717

RESUMO

In this work, a novel electrochemical immunoassay protocol has been reported for simultaneous determination of multiple tumor biomarkers based on DNA hybridization chain reaction (HCR) for signal amplification. Alpha-fetoprotein (AFP) and prostate specific antigen (PSA) were selected as model biomarkers. The immunoassay protocol contained primary antibodies immobilized on gold nanoparticles (Au NPs), secondary antibodies conjugated with DNA concatemer from HCR of primer, auxiliary probe, and signal probe labeled with signal molecules (methyleneblue (MB) and ferrocene (Fc)). In the presence of target biomarkers, the sandwich immunocomplex was formed between the primary antibodies and secondary antibodies bioconjugates carrying numerous signal molecules. As a result, two well-resolved reduction peaks, one was at -0.35 V (corresponding to MB) and other was at 0.33 V (corresponding to Fc; both vs SCE), were obtained in differential pulse voltammetry, and peak currents changed were related to the level of biomarkers. Under optimal conditions, the electrochemical immunoassay exhibited a wide linear response range (0.5 pg mL(-1) to 50 ng mL(-1)) and low detection limits (PSA, 0.17 pg mL(-1); AFP, 0.25 pg mL(-1)) (at S/N = 3). In addition, the immunoassay was evaluated by analyzing simulate human serum sample, and the recoveries obtained were within 99.4-107.6% for PSA and 97.9-108.2% for AFP, indicating the immnuoassay could be applied to the simultaneous detection of AFP and PSA in human serum samples.


Assuntos
Biomarcadores Tumorais/análise , DNA Concatenado/química , Calicreínas/análise , Técnicas de Amplificação de Ácido Nucleico/métodos , Antígeno Prostático Específico/análise , alfa-Fetoproteínas/análise , Humanos , Imunoensaio/métodos
11.
Anal Biochem ; 491: 58-64, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26384641

RESUMO

In this study, a novel tracer, horseradish peroxidase (HRP) functionalized gold nanorods (Au NRs) nanocomposites (HRP-Au NRs), was designed to label the signal antibodies for sensitive electrochemical measurement of alpha-fetoprotein (AFP). The preparation of HRP-Au NRs nanocomposites and the labeling of secondary antibody (Ab2) were performed by one-pot assembly of HRP and Ab2 on the surface of Au NRs. The immunosensor was fabricated by assembling carbon nanotubes (CNTs), Au NRs, and capture antibodies (Ab1) on the glassy carbon electrode. In the presence of AFP antigen, the labels were captured on the surface of the Au NRs/CNTs via specific recognition of antigen-antibody, resulting in the signal intensity being clearly increased. Differential pulse voltammetry (DPV) was employed to record the response signal of the immunosensor in phosphate-buffered saline (PBS) containing hydrogen peroxide (H2O2) and 3,3',5,5'-tetramethylbenzidine (TMB). Under optimal conditions, the signal intensity was linearly related to the concentration of AFP in the range of 0.1-100 ng ml(-1), and the limit of detection was 30 pg ml(-1) (at signal/noise [S/N] = 3). Furthermore, the immunoassay method was evaluated using human serum samples, and the recovery obtained was within 99.0 and 102.7%, indicating that the immunosensor has potential clinical applications.


Assuntos
Técnicas Eletroquímicas , Ouro/química , Peroxidase do Rábano Silvestre/metabolismo , Imunoensaio , Nanotubos/química , alfa-Fetoproteínas/análise , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Benzidinas/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Peroxidase do Rábano Silvestre/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Nanotubos de Carbono/química , alfa-Fetoproteínas/imunologia
12.
Anal Biochem ; 482: 48-54, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25911042

RESUMO

In this work, a novel sandwich-type electrochemical immunosensor has been developed for simultaneous detection of carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) based on metal ion labels. Gold nanoparticles decorated multiwall carbon nanotubes (AuNPs@MWCNTs) were used as carriers to immobilize secondary antibodies and distinguishable electrochemical tags of Pb(2+) and Cd(2+) to amplify the signals. Due to the intrinsic property of high surface-to-volume ratio, the AuNPs@MWCNTs could load numerous secondary antibodies and labels. Therefore, the multiplexed immunoassay exhibited good sensitivity and selectivity. Experimental results revealed that this sandwich-type immunoassay displayed an excellent linear response, with a linear range of 0.01 to 60 ng mL(-1) for both analytes and detection limits of 3.0 pg mL(-1) for CEA and 4.5 pg mL(-1) for AFP (at a signal-to-noise ratio of 3). The method was successfully applied for the determination of AFP and CEA levels in clinical serum samples.


Assuntos
Anticorpos Imobilizados/química , Antígeno Carcinoembrionário/sangue , Técnicas Eletroquímicas/métodos , Ouro/química , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , alfa-Fetoproteínas/análise , Biomarcadores/análise , Biomarcadores/sangue , Cádmio/química , Cátions Bivalentes/química , Humanos , Imunoensaio/métodos , Chumbo/química , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Nanotubos de Carbono/ultraestrutura
13.
Opt Express ; 22(10): 11417-26, 2014 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-24921263

RESUMO

We report the generation of tunable single-, switchable and tunable dual-, and stable triple-wavelength dissipative solitons (DSs) in an all-normal-dispersion mode-locked Yb-doped fiber laser based on a graphene-oxide saturable absorber (GOSA) without additional components (such as optical filter, or fiber grating). The tunable single-wavelength DS have a wide wavelength-tunable range of 16.4 nm. The dual-wavelength DSs not only have a wavelength-tunable range (about 10 nm) but also have variable wavelength spacing (3.8-13.8 nm). The formation dynamics of the triple-wavelength DSs was also investigated experimentally. The different operations of tunable single-, switchable and tunable dual-, and stable triple-wavelength DSs depend on the strength of the cavity birefringence. The simple, compact all-fiber DS laser with lasing wavelength tunability and flexibility can meet great potential for applications.

14.
Chin Med J (Engl) ; 127(10): 1924-30, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24824257

RESUMO

BACKGROUND: Hepatocyte growth factor (HGF) inhibits the development of pulmonary artery hypertension (PAH) by reducing pulmonary artery pressure and right ventricle (RV) hypertrophy. However, whether HGF can prevent RV remodeling via inhibiting apoptosis in RV cardiomyocytes and decreasing neurohormonal activation remains unknown. METHODS: The PAH and subsequent RV remodeling in rats were induced by subcutaneous injection of monocrotaline (MCT). The PAH rats were transfected with adenovirus carrying HGF (Ad-HGF) via intratracheal instillation. Three weeks after transfection, the hemodynamics indexes were measured, serum levels for angiotonin II (ANG II) and brain natriuretic peptide (BNP) were determined by ELISA. Histological analysis was used to assess the RV hypertrophy and fibrosis. The cardiomyocyte apoptosis in RV was assayed by TUNEL staining. The mRNA expression of BNP, angiotensin-converting enzyme (ACE), Bax and Bcl-2 in RV was determined by reverse transcriptase polymerase chain reaction (RT-PCR), the protein expression of transforming growth factor (TGF)-ß1 and tumor necrosis factor (TNF)-α in RV was determined by Western blotting. RESULTS: HGF treatment significantly decreased the mean PAH, RV systolic pressure, serum ANG II and BNP levels. HGF treatment also significantly decreased the RV hypertrophy, collagen deposition, and the number of apoptotic cardiomyocytes. Moreover, HGF treatmemt significantly decreased the expression of BNP, ACE, Bax, TGF-ß1, and TNF-α, while it significantly increased the expression of Bcl-2. CONCLUSIONS: Gene transfer of HGF decreases MCT-induced PAH and improves RV remodeling. This effect is mediated not only by improving the hemodynamics but also by decreasing neurohormonal activation and inhibiting cardiomyocytes apoptosis. HGF gene treatment may be an effective strategy for improving RV remodeling in MCT-induced PAH.


Assuntos
Fator de Crescimento de Hepatócito/fisiologia , Fator de Crescimento de Hepatócito/uso terapêutico , Hipertensão Pulmonar/terapia , Remodelação Ventricular/fisiologia , Animais , Apoptose/genética , Apoptose/fisiologia , Fator de Crescimento de Hepatócito/genética , Humanos , Hipertensão Pulmonar/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Remodelação Ventricular/genética
15.
Appl Opt ; 52(35): 8465-70, 2013 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-24513889

RESUMO

We experimentally observed three types of pulses generated in an erbium-doped fiber laser by incorporating a homemade graphene saturable absorber (GSA). The generated pulses from the laser oscillator include dual-wavelength dark pulses, fundamentally step-like pulses, and non-soliton second-harmonic pulses. These operation regimes are first reported by using graphene as the saturable absorber. Our results will further indicate that the GSA can function well for obtaining various ultrafast pulse phenomena, highlighting the practical potential of graphene in ultrafast photonics technologies.

16.
Opt Express ; 19(6): 4985-90, 2011 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-21445134

RESUMO

We have fabricated a novel nanoweb fiber with web-like bundle of the fused-silica membranes with different thickness in its cross section. We pumped the 0.55-µm-thick membrane with 200-fs laser pulse at 800-nm just adjacent to its second-zero-dispersion wavelength, and demonstrated the polarization dependent visible supercontinuum (SC). The mode patterns were recorded in detail and analyzed at different polarization angles of incident pulse. The broadband spectrum range from ~350 nm to 950 nm is achieved for TM mode excitation. The tunable visible SC in the nanoweb fiber may be used in the substrate integrated waveguide for sensing.

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