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Objective: Matrix metalloproteinase is a family of proteases with different pathophysiological roles. Matrix metalloproteinase 9 (MMP9) plays an enzymatic role in the restructuring of the extracellular matrix and adhesion molecules. MMP9 is upregulated in pro-inflammatory states and leads to breakdown of tight junctions thereby increasing blood-brain barrier (BBB) permeability. MMP9 may contribute to the pathophysiology of bipolar disorder (BD) via proteolysis of the BBB thus allowing entry of cytokines and neurotoxic agents into CNS. Polymorphisms of the MMP9 gene may pose increased risk for BD and schizophrenia. In this study we sought to determine MMP9 levels in treatment resistant bipolar depressed patients before and after treatment. Methods: Treatment resistant bipolar depressed patients were treated with escitalopram, in combination with the COX-2 inhibitor, celecoxib. It was hypothesized that combination treatment would reverse resistance and augmented treatment responses. This was a 10-week, randomized, double-blind, two-arm, placebo-controlled study. Results: MMP9 levels were higher in bipolar depressed patients compared to healthy controls at baseline, however, the difference did not reach significance. Levels decreased after treatment reaching significance in the escitalopram plus placebo group. Female patients had significantly lower MMP9 levels at end of treatment. MMP9 was higher in carriers the MMP9 SNP, rs3918242, than in noncarriers, but the difference did not reach statistical significance. Conclusion: MMP9 decreased in bipolar depressed patients with treatment. Age, sex and the rs3918242 polymorphism play a role in MMP9 levels. Future studies should confirm the role of MMP9 in the pathogenesis and pathophysiology of bipolar disorder, as a potential diagnostic biomarker.

In the study of noise from propellers and ducted fans, rigorous signal decomposition into harmonic and broadband components is essential for the development of high-delity predictive models. Current spectral methods and phase averaging techniques lack the temporal resolution to compensate for uctuations in operating condition intrinsic to real world experiments. In this paper we use a Vold-Kalman lter to extract the tonal and broadband content of noise from a small ducted fan simulating the conditions of an ultrahigh-bypass turbofan engine. The fan operated at pressure ratio of 1.15 and tip Mach number of 0.61. The investigation includes time traces, narrowband spectra, one-third octave spectra, and overall sound pressure level. The energies of the tonal and broadband components are similar at low frequency, while the broadband component dominates at high frequency. In addition, there are distinct dierences in the directivities of the two components. The trends are in general agreement with NASA large-scale fan tests at transonic conditions.

This study evaluated the feasibility of simulating the aerodynamics and acoustics of ducted fans using small-scale components (approximately 1/38 th scale). Enabling technologies include high-definition stereolithography and high-performance, compact DC brushless motors used in model aircraft. The 70-mm ducted fan featured a 14-bladed rotor and 24 stators, and operated at fan pressure ratio of 1.15 and rotor tip Mach number of 0.61. Its operation was thus representative of turbofan engines with very large bypass ratio. The far-field acoustics were surveyed in the downward and sideline planes. The acoustic results of the isolated ducted fan compare favorably with past large-scale experiments. In addition, the project provided initial data on the shielding of ducted-fan noise using a surface that approximated the shape of the blended wing body airplane. The BWB-shaped shield featured removable inboard fins and a moveable elevon, and translated axially to enable various positions of the nacelle relative to the elevon trailing edge. The EPNL reduction on the downward plane ranged from 7.6 dB with the engine at its nominal location to 10.4 dB with the engine moved forward by one fan diameter. Sideline EPNL reduction was marginal with the fins off and reached about 3.0 dB with the fins installed. Upward deflection of the elevon improved moderately the shielding.

This study examines the potential of very-small-scale experiments to simulate the acoustics of large scale counter-rotating open rotors in isolation and with a rectangular-plate shield. The experimental rotor model was based on the historical F7/A7 design developed by General Electric. The 80-mm diameter rotors were fabricated using advanced stereolithography and were powered by two high-performance DC brushless motors. Realistic tip Mach numbers were achieved with the rotors spinning near 50000 rpm. Far-field acoustic surveys were conducted inside an anechoic chamber using a 12-microphone array. The isolated tests captured the tonal and broadband contents of open rotor noise. Rotor-alone tones dominated the sound emission in the vicinity of the rotor plane. In the aft direction, interaction tones were very strong. Addition of the rectangular plate shield created complex trends in the tonal content. Tones radiating in the direction of the rotor plane were well attenuated, while tones emitted in the aft direction were poorly shielded. Some tones were amplified with insertion of the shield. Even though the shield reduced the noise level in an overall sense, the complicated tonal pattern presents challenges for the effective reduction of aircraft noise.