Resumo: O artigo visa apresentar a importância do papel das agências reguladoras na garantia do princípio constitucional da Livre Concorrência. Neste trabalho, iremos abordar de que forma se ...comporta o sistema econômico brasileiro, como a livre concorrência vem sendo praticada dentro desse contexto moderno, quais os deveres jurídicos comuns das Agências Reguladoras, bem como as propostas de uniformização da legislação pertinente a estas. Com base no recorte de dois estudos de caso, verificaremos de que forma as agências podem contribuir, dentro dos seus deveres jurídicos, na tarefa de regulação do domínio econômico, para garantir a livre concorrência.Abstract: The article aims to present the importance of the role of regulatory agencies in guaranteeing the constitutional principle of Free Competition. In this work, we will address how the Brazilian economic system behaves, how free competition is practiced within this modern context, what are the common legal duties of the Regulatory Agencies, as well as the proposals to standardize the legislation pertinent to them. Based on the cut of two case studies, we will verify how agencies can contribute, within their legal duties, in the task of regulating the economic domain, to guarantee free competition.
The tremendous enhancement factors that surface‐enhanced Raman scattering (SERS) possesses coupled with the flexibility of photonic crystal fibers (PCFs) pave the way to a new generation of ...ultrasensitive biosensors. Thanks to the unique structure of PCFs, which allows direct incorporation of an analyte into the axially aligned air channels, interaction between the analyte and excitation light could be increased many folds leading to flexible, reliable and sensitive probes that can be used in preclinical or clinical biosensing. SERS‐active PCF probes provide unique opportunity to develop an opto‐fluidic liquid biopsy needle sensor that enables one‐step integrated sample collection and testing for disease diagnosis. Specificity being a key parameter to biosensors, the PCF inside the biopsy needle could be functionalized with targeting moieties to detect specific biomarkers. In this review article, we present some of the most promising recent biosensors based on PCFs including hollow‐core PCFs, suspended‐core PCFs and side‐channel PCFs. We provide a wide range of applications of such platform using Raman spectroscopy, label free SERS or labeled SERS detection and analyze some of the main challenges to be addressed for translating it to a clinically viable next generation sensitive biopsy needle sensing probe.
Tremendous enhancement factor that surface‐enhanced Raman scattering (SERS) possesses coupled with the flexibility of photonic crystal fibers (PCFs) pave the way to a new generation of ultrasensitive biosensors. This review article aims to provide the latest advancement in SERS‐based PCF sensors for various bio‐chemical applications. Such a sensitive biosensor could be translated for the detection of biomarkers in body fluids for early diagnosis of diseases.
The detection for small molecules with low concentrations is known to be challenging for current chemical and biological sensors. In this work, we designed a highly sensitive plasmonic biosensor ...based on the symmetric metal cladding plasmonic waveguide (SMCW) structure for the detection of biomolecules. By precisely designing the configuration and tuning the thickness of the guiding layer, ultra-high order modes can be excited, which generates a steep phase change and a large position shift from the Goos–Hänchen effect (with respect to refractive index changes). This position shift is related to the sharpness of the optical phase change from the reflected signal of the SPR sensing substrate and can be directly measured by a position sensor. Based on our knowledge, this is the first experimental study done using this configuration. Experimental results showed a lateral position signal change > 90 µm for glycerol with a sensitivity figure-of-merit of 2.33 × 104 µm/RIU and more than 15 µm for 10−4 M biotin, which is a low molecular weight biomolecule (less than 400 Da) and difficult to be detected with traditional SPR sensing techniques. Through integrating the waveguide with a guiding layer, a strong improvement in the electric field, as well as sensitivity have been achieved. The lateral position shift has been further improved from 14.17 µm to 284 µm compared with conventional SPR substrate with 50 nm gold on single side. The as-reported sensing technique allows for the detection of ultra-small biological molecules and will play an important role in biomedical and clinical diagnostics.
Hollow-core photonic crystal fibers have unusual properties which make them ideally suited to delivery of laser beams. We describe the properties of fibers with different core designs, and the ...observed effects of anti-crossings with interface modes. We conclude that 7-unit-cell cores are currently most suitable for transmission of femtosecond and sub-picosecond pulses, whereas larger cores (e.g. 19-cell cores) are better for delivering nanosecond pulsed and continuous-wave beams.
We report smooth and broad continuum generation using a compact femtosecond Ti:Sapphire laser as a pump source and a tapered photonic crystal fibre as a nonlinear element. Spectral output is ...optimized for use in optical coherence tomography, providing a maximum longitudinal resolution of 1.5 microm in free space at 809 nm centre wavelength without use of additional spectral filtering.
We present the fabrication of multimaterial polarization maintaining optical fibers. We exploit the flexibility of the powder-in-tube process for fabricating silica-based optical fibers composed of ...two rods of glass material on the sides of the core. We demonstrate the capability of this process to use glass material with properties sorely different from the ones of silica for developing high-birefringence optical fiber. This proof-of-concept paves the way for the use of different materials with specific properties for improving the performances of polarization maintaining optical fibers.
Specialty fibers have introduced new functionalities and opportunities in distributed fiber sensing applications. Particularly, Brillouin optical time domain analysis (BOTDA) systems have leveraged ...the unique features of specialty fibers to achieve performance enhancement in various sensing applications. This paper provides an overview of recent developments of the specialty fibers based BOTDA technologies and their sensing applications. The specialty fibers based BOTDA systems are categorized and reviewed based on the new features or performance enhancements. The prospects of using specialty fibers for BOTDA systems are discussed.
We build ring resonators to assess the potentialities of Kagome Hollow-Core Photonic Crystal Fibers for future applications to resonant rotation sensing. The large mode diameter of Kagome fibers ...permits to reduce the free space fiber-to-fiber coupling losses, leading to cavities with finesses of about 30 for a diameter equal to 15cm. Resonance linewidths of 3.2MHz with contrasts as large as 89% are obtained. Comparison with 7-cell photonic band gap (PBG) fiber leads to better finesse and contrast with Kagome fiber. Resonators based on such fibers are compatible with the angular random walk required for medium to high performance rotation sensing. The small amount of light propagating in silica should also permit to further reduce the Kerr-induced non-reciprocity by at least three orders of magnitudes in 7-cell Kagome fiber compared with 7-cell PBG fiber.
•Kagome hollow-core photonic crystal fibers are considered for use in resonant fiber optic gyros.•A semi-bulk test cavity is built to assess the potentialities of two different Kagome fibers.•Kagome fibers are proved to have interesting potentialities for resonant fiber optic gyros.
All-in-fiber optofluidics is an analytical tool that provides enhanced sensing performance with simplified analyzing system design. Currently, its advance is limited either by complicated liquid ...manipulation and light injection configuration or by low sensitivity resulting from inadequate light-matter interaction. In this work, we design and fabricate a side-channel photonic crystal fiber (SC-PCF) and exploit its versatile sensing capabilities in in-line optofluidic configurations. The built-in microfluidic channel of the SC-PCF enables strong light-matter interaction and easy lateral access of liquid samples in these analytical systems. In addition, the sensing performance of the SC-PCF is demonstrated with methylene blue for absorptive molecular detection and with human cardiac troponin T protein by utilizing a Sagnac interferometry configuration for ultra-sensitive and specific biomolecular specimen detection. Owing to the features of great flexibility and compactness, high-sensitivity to the analyte variation, and efficient liquid manipulation/replacement, the demonstrated SC-PCF offers a generic solution to be adapted to various fiber-waveguide sensors to detect a wide range of analytes in real time, especially for applications from environmental monitoring to biological diagnosis.
A specialty fiber with a built-in microfluidic channel enables ultra-sensitive, low-loss and compact all-in-fiber in-line optofluidic chemical and biological sensing.
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