A Compressible Reconfigurable Frequency Selective Surface

Frequency selective surfaces (FSSs) are periodic structures which perform a spatial filtering operation, such as band-pass, band-stop, etc. in application of multiband reflector antennas, radomes, absorbers and so on. The filtering is normally achieved by periodic arrangement of metallic shapes or slots on a dielectric slab. The responses of the FSS are impacted by the unit cell structure, type of the element, material properties and arrangement of the array. The interest in frequency agile and wideband systems has led to an expanding design space to include reconfigurable FSSs. Reconfigurable FSSs have the advantages of wider range of operating frequencies, compensation for fabrication errors by tuning mechanically. The reconfiguration could be achieved by solid-state devices (varactors, PIN diodes), usage of semiconductors, changing the substrates’ characteristics or the dimensions of the elements. Tunable FSS are in practical need for applications such as tunable radomes and adaptive screening of unwanted wireless transmissions. For a continuous tuning over the frequency range, fluidic tuning and mechanical reconfigurable FSSs claim to deliver the most dramatic continuous parameter variations. In this work, a 3-D mechanically tunable FSS has been presented with a band-stop characteristic. The 3-D FSSs has displayed greater flexibility and controllability compared to conventional 2D FSSs. They have the ability of setting the resonant frequency and continuous tuning the operational filter states with a change in length or height of the resonator, offering the tuning and switching functionality from the same structure without the use of additional electrical components. In this design, the reconfiguration is achieved by compressing the FSS structure, varying the height and the element shapes. Simulations and measurements of a FSS prototype manufactured by 3-D printer, some metallic and dielectric components are provided to demonstrate the tuning capability in S-band. A 490 MHz tuning range could be achieved by this design, while adding some dielectric material inside, a wider tuning range of 600 MHz could be reached. The measurement results show a good match with the design by HFSS

Micromachined coupled resonator butler matrix

This thesis presents the design and characterisation of a micromachined Butler Matrix operating at WR-3 band (220 GHz to 325 GHz). For this thesis a two port Butler matrix is used, here there are two input ports and two output ports. When signal is applied to one of the input ports then it is equally split between the output ports, but has a 90 degree phase shift. In general Butler matrices can have many ports. Conventionally transmission lines are used to make a Butler Matrix but in this thesis, the Butler Matrix is realised only in resonators. This technique is implemented by the appropriate couplings between resonators and the coupling between the resonators and the external ports. The method has the advantage of applying to any type of resonator can be used no matter what its physical structure. SU-8 photoresist micromachining technology is used for fabrication and three metal-coated SU-8 layers are used to implement this micromachined coupled resonator Butler Matrix. The fabrication process was not successful thus no useful measurement results had been made. Low loss bends are designed for the connections between the Butler Matrix and the loads and flanges. A two-element slotted waveguide antenna array is designed to be connected to the Butler Matrix to build a beamforming system and to verify the characterisation of the Butler Matrix

Anti-inflammatory effects of Fritillaria ussuriensis maxim

Bulbs of Fritillaria ussuriensis Maxim., usually known as Bulbus Fritillariae ussuriensis, (BFU) has been used as antitussive, antiasthmatic and expectorant in traditional herbal medicine. In this study, the aqueous extract of BFU (BFUE) was evaluated for its anti-inflammatory activity. Meanwhile, the content of PGE2 and MDA in inflammatory exudates was measured to explore the anti-inflammatory mechanisms of BFUE. In order to identify the active components of BFU, the total alkaloids (TA), the total flavonoids (TF) and the total saponins (TS) were evaluated for their bioactivities. Results showed that BFUE inhibited carrageenin-induced paw edema, xylene-induced auricular edema and acetic acid-induced vascular permeation in a dose-dependent manner, and it revealed obvious inhibitory effects on the increase of PGE2 and MDA. TF showed the highest anti-inflammatory effects on auricular edema induced by xylene in mice, and TS at a dose of 400 and 200 mg/kg also showed good effects (P 2 and MDA levels, and TF and TS might be the active components for this activity.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Anti-inflammatory effects of Fritillaria ussuriensis maxim

Bulbs of Fritillaria ussuriensis Maxim., usually known as Bulbus Fritillariae ussuriensis, (BFU) has been used as antitussive, antiasthmatic and expectorant in traditional herbal medicine. In this study, the aqueous extract of BFU (BFUE) was evaluated for its anti-inflammatory activity. Meanwhile, the content of PGE2 and MDA in inflammatory exudates was measured to explore the anti-inflammatory mechanisms of BFUE. In order to identify the active components of BFU, the total alkaloids (TA), the total flavonoids (TF) and the total saponins (TS) were evaluated for their bioactivities. Results showed that BFUE inhibited carrageenin-induced paw edema, xylene-induced auricular edema and acetic acid-induced vascular permeation in a dose-dependent manner, and it revealed obvious inhibitory effects on the increase of PGE2 and MDA. TF showed the highest anti-inflammatory effects on auricular edema induced by xylene in mice, and TS at a dose of 400 and 200 mg/kg also showed good effects (P 2 and MDA levels, and TF and TS might be the active components for this activity.Colegio de Farmacéuticos de la Provincia de Buenos Aire

miRecords: an integrated resource for microRNA–target interactions

MicroRNAs (miRNAs) are an important class of small noncoding RNAs capable of regulating other genes’ expression. Much progress has been made in computational target prediction of miRNAs in recent years. More than 10 miRNA target prediction programs have been established, yet, the prediction of animal miRNA targets remains a challenging task. We have developed miRecords, an integrated resource for animal miRNA–target interactions. The Validated Targets component of this resource hosts a large, high-quality manually curated database of experimentally validated miRNA–target interactions with systematic documentation of experimental support for each interaction. The current release of this database includes 1135 records of validated miRNA–target interactions between 301 miRNAs and 902 target genes in seven animal species. The Predicted Targets component of miRecords stores predicted miRNA targets produced by 11 established miRNA target prediction programs. miRecords is expected to serve as a useful resource not only for experimental miRNA researchers, but also for informatics scientists developing the next-generation miRNA target prediction programs. The miRecords is available at http://miRecords.umn.edu/miRecords

BETTER SAFE THAN SORRY:SITUATIONAL CORRECTION IN INTERPERSONAL COMPETITION

We conducted two experiments to investigate whether situational correction occurs when interpersonal competitors make dispositional inferences from their opponent's situationally constrained behavior. In both experiments, participants who expected interpersonal competition, judged a target person's disposition after reading information about a constrained or not constrained behavior of their opponent or non-opponent. As predicted, we found that insufficient situational correction occurred when the situationally constrained behavior of the opponent reflected a disposition that implied a high threat level (competitiveness or high ability) but sufficient correction occurred when the behavior reflected a low threat-level disposition (cooperativeness or low ability). Finally, we discussed the relationship between risk-avoidance and situational correction in competition

Characterization of EndoTT, a novel single-stranded DNA-specific endonuclease from Thermoanaerobacter tengcongensis

EndoTT encoded by tte0829 of Thermoanaerobacter tengcongensis binds and cleaves single-stranded (ss) and damaged double-stranded (ds) DNA in vitro as well as binding dsDNA. In the presence of a low concentration of NaCl, EndoTT cleaved ss regions of damaged dsDNA efficiently but did not cleave DNA that was entirely ss or ds. At high concentrations of NaCl or MgCl2 or ATP, there was also specific cleavage of ssDNA. This suggested a preference for ss/ds junctions to stimulate cleavage of the DNA substrates. EndoTT has six specific sites (a–f) in the oriC region (1–70 nt) of T. tengcongensis. Substitutions of nucleotides around site c prevented cleavage by EndoTT of both sites c and d, implying that the cleavage specificity may depend on both the nucleotide sequence and the secondary structure of the ssDNA. A C-terminal sub-fragment of EndoTT (residues 107–216) had both endonucleolytic and DNA-binding activity, whereas an N-terminal sub-fragment (residues 1–110) displayed only ssDNA-binding activity. Site-directed mutations showed that G170, R172 and G177 are required for the endonuclease activity of EndoTT, but not for DNA-binding, whereas D171, R178 and G189 are partially required for the DNA-binding activity