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Phycobiliproteins are brilliant-colored and water-soluble pigment-protein complexes existing widely in cyanobacteria, red algae, and cryptophytes. They function as predominant light-harvesting complexes to absorb the sunlight from 480 to 660 nm, and efficiently transfer the energy to chlorophyll a. The phycobiliproteins are classified into three types based on their absorption spectra: phycoerythrin (PE), phycocyanin (PC), and allophycocyanin (AP). They are all composed of hetero-subunits α and β and commonly exist in trimer (αβ)3 or hexamer (αβ)6 made up of equimolar monomer (αβ). One monomer contains two to five chromophore phycobilins. In cyanobacteria and red algae, phycobiliproteins assemble a macromolecular particle, phycobilisome. Efficient excitation energy coupling among the chromophores in the phycobiliprotein trimer/hexamer and among the phycobiliproteins in the phycobilisome gives them some special spectroscopic properties superior to organic fluorescent dyes. These properties make the phycobiliproteins become promising fluorescent probes used in various fields of biological investigation. [ABSTRACT FROM PUBLISHER]

A waveguide crossing mechanism based on metamaterial is proposed and numerically investigated using finite difference in time domain method. The waveguide cross is filled with impedance matched metamaterial, which has a large absolute value of refractive index, and effectively suppresses the diffraction of the guiding mode in the crossing region. The waveguide cross is ultra compact, and valid for a wide range of crossing angle with negligible crosstalk and insertion loss. The compactness and high efficiency make this crossing mechanism valuable in micro and nano photonics. [ABSTRACT FROM AUTHOR]

In this paper, taking the minimum metal conductor usage of an air core reactor as optimization goal, the influence of air ducts width and encapsulation number on thermal efficiency and electromagnetic efficiency are analyzed. Combined with the equation constraint conditions for maximum temperature rise conservation, inductance conservation and structure function of reactor considering the change of air ducts width and encapsulation number, the thermal and electromagnetic combined optimization curves are formed, and design results are achieved based on the initial design parameters. Meanwhile, the temperature field simulation model of the reactor is established and the results verify the correctness of the optimization method. According to the design results, the proportionality factor of metal conductor usage is only 0.61 compared with the initial design parameters of the reactor, which shows that the proposed comprehensive optimization method can significantly reduce conductor usage, improving the metal conductor utilization ratio. [ABSTRACT FROM AUTHOR]

Objective(s): The present study aims to establish and evaluate a rat model for hangover headaches caused by alcoholic drinks. Materials and Methods: Chronic migraine (CM) model rats were divided into 3 groups, and intragastrically administered alcoholic drinks (sample A, B, or C) to simulate hangover headache attacks. The withdrawal threshold for the hind paw/face and the thermal latency of hind paw withdrawal were detected after 24 hr. Serum was collected from the periorbital venous plexus of rats in each group, and enzymatic immunoassays were used to determine the serum levels of calcitonin gene-related peptide (CGRP), substance P (SP), and nitric oxide (NO). Results: Compared with the control group, the mechanical hind paw pain threshold was significantly lower in rats administered Samples A and B after 24 hr; however, no significant difference was observed across groups for the thermal pain threshold. The mechanical threshold for periorbital pain was only significantly reduced in rats administered Sample A. Immunoassays further indicated that serum levels of SP in the group administered Sample A were significantly higher than those in the control group; the serum levels of NO and CGRP were significantly higher in the group of rats receiving Sample B. Conclusion: We successfully developed an effective and safe rat model for investigating alcohol drink induced hangover headaches. This model could be used to investigate the mechanisms associated with hangover headaches for the development of novel and promising candidates for the future treatment or prophylaxis of hangover headaches. [ABSTRACT FROM AUTHOR]

The article presents a study that deals with recombinant defective adenovirus vector carrying human phosphatase and tensin homolog-deleted on chromosome ten (Ad-PTEN). The system was constructed using the AdEasy-1 system and was transfected into HEK293 cells for packaging and amplification. Based on results, the authors discovered a cytopathic effect in green fluorescent protein expression.

This paper presents theoretical investigations on the dynamics of intrinsic optical bistability (IOB) in Tm3+/Yb3+ codoped systems with an upconversion avalanche mechanism. Numerical simulations based on the rate equation model demonstrate distinct IOB hysteresis and critical slowing dynamics around the avalanche thresholds. Moreover, the unusual IOB characteristics are well interpreted by developing a simplified analytic model which gives the formulations of two critical thresholds and the necessary condition for IOB to occur. The simplified model shows that such IOB phenomena may occur only if the total quantum yields of the dipole-dipole energy transfer processes are much higher than that of the inherent decay losses involved in an upconversion avalanche. The analytic model developed in the paper may be useful for the prediction of new rare-earth-doped materials giving rise to IOB. [ABSTRACT FROM AUTHOR]

In this paper, we predict and numerically demonstrate the intrinsic intensity bistability, spectra bistability and chromatic switching of visible-infrared emission in Tm3+ single-doped systems that are pumped by the photon avalanche scheme at 648 nm. Based on the coupled rate equation theory, the evolutions of the populations at various Tm3+ energy levels, emission spectra and fluorescence intensity versus pump excitation are numerically investigated in detail. The results show that intrinsic optical bistability (IOB) associated with emission spectra and luminescence intensity takes place in the vicinity of the avalanche threshold ([?]10 kW cm[?]2). When the pump excitation rises above the switching threshold ([?]17.5 kW cm[?]2), the chromatic switching between the infrared (1716 nm) and the visible blue (452/469 nm) spectra can be performed. Moreover, the influences of system parameters on IOB and the origin of chromatic switching are discussed. These unique characteristics of Tm3+-doped systems would lead to the new possibility of the development of pump-controlled all-solid-state luminescence switches and optical bistability switches. [ABSTRACT FROM AUTHOR]

In this paper, a new kind of coupling mechanical high-voltage direct current (HVDC) circuit breaker topology based on pulse transformer is proposed and its working principle is analysed in detail. On the basis of the requirement of 160 kV rated voltage, and 9 kA breaking current, the varying trend and design principle of parameters are given by the theoretical calculation. The prototype design of 160 kV HVDC circuit breaker is completed and type test passes. Results prove that the prototype of 160 kV HVDC circuit breaker has natural bi-directional breaking capacity. It can interrupt the current below 9 kA and withstand transient interruption voltage 272 kV. The breaking time is <5 ms. [ABSTRACT FROM AUTHOR]