Are all Cages Created Equal? Analysis of Cervical Cage Malfunctions Using FDA MAUDE Database.

Study Design: Retrospective case series.

Objective: To characterize failure rates of cervical cages based on manufacturer and design characteristics using the nationwide database of reported malfunctions.

Background: The Food and Drug Administration (FDA) aims to ensure the safety and efficacy of cervical interbody implants postimplantation; however, intraoperative malfunctions may be overlooked.

An Analysis of a Decade of Lumbar Interbody Cage Failures in the United States: A MAUDE Database Study.

Study Design: A retrospective case series.

Objective: This study aims to assess the rates of lumbar interbody cage failures based on their material and manufacturer.

Summary Of Background Data: Perioperative lumbar interbody cage malfunctions are underreported events in the spine literature and may result in complications.

BDNF genotype Val66Met interacts with acute plasma BDNF levels to predict fear extinction and recall.

Brain-derived neurotropic factor (BDNF) is a potent regulator of memory processes and is believed to influence the consolidation of fear extinction memories. No previous human study has tested the effect of unstimulated BDNF on fear extinction recall, and no study has tested the association between plasma BDNF levels and psychophysiological responding during an extinction paradigm. We tested the association between fear responses during a 2-day differential conditioning, extinction and extinction recall paradigm and Val66Met genotype in a group of healthy participants (N = 191).

An alternative theory for hormone effects on sex differences in PTSD: The role of heightened sex hormones during trauma.

Women are at least twice as susceptible to developing post-traumatic stress disorder (PTSD) compared to men. Although most research seeking to explain this discrepancy has focussed on the role of oestradiol during fear extinction learning, the role of progesterone has been overlooked, despite relatively consistent findings being reported concerning the role of progesterone during consolidation of emotional and intrusive memories. In this review article, we outline literature supporting the role of progesterone on memory formation, with particular emphasis on potential memory-enhancing properties of progesterone when subjects are placed under stress.

Flexible light valves using polymer-dispersed liquid crystals and TiO/Ag/TiO multilayers.

The era of flexible optoelectronics demands development of wearable and bendable structures, foldable touch screens, paper-like displays, and curved and flexible solid-state lighting devices. Here, we demonstrate the fabrication of highly flexible light valves using polymer-dispersed liquid crystal (PDLC) and TiO/Ag/TiO transparent conductive films. TiO/Ag/TiO multilayers were prepared by magnetron sputtering technique on polyethylene terephthalate (PET) substrates at room temperature.

The BDNF Val66Met polymorphism moderates the relationship between Posttraumatic Stress Disorder and fear extinction learning.

The low expression Met allele of the BDNF Val66Met polymorphism is associated with impaired fear extinction in healthy controls, and poorer response to exposure therapy in patients with Posttraumatic Stress Disorder (PTSD). Given that fear extinction underlies exposure therapy, this raises the question of the impact of BDNFVal66Met polymorphism on fear extinction in PTSD, yet this question has not yet been examined. One hundred and six participants (22 PTSD, 46 trauma-exposed controls (TC) and 38 non-trauma exposed controls (NTC)) completed a fear conditioning and extinction task and saliva samples were taken for DNA extraction and genotyped for the BDNF Val66Met polymorphism.

Volume polarization holographic recording in thick photopolymer for optical memory.

Based on a vector wave theory of volume holograms, dependence of holographic reconstruction on the polarization states of the writing and reading beams is discussed. It is found that under paraxial approximation the circular polarization holograms provide a better distinction of the reading beams. Characteristics of recording polarization holograms in thick phenanthrenequinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer are experimentally investigated.

Near-infrared sensitive photorefractive device using polymer dispersed liquid crystal and BSO:Ru hybrid structure.

A near-infrared sensitive hybrid device, based on a Ru-doped BSO photorefractive substrate and polymer dispersed liquid crystal (PDLC) layer, is reported. It is found that the photoexcited charge carriers generated in the BSO:Ru substrate create an optically induced space charge field, sufficient to penetrate into the PDLC layer and to re-orient the LC molecules inside the droplets. Beam-coupling measurements at the Bragg regime are performed showing prospective amplification values and high spatial resolution.

Heterodyne moiré surface profilometry.

In this study, a novel moiré fringe analysis technique is proposed for measuring the surface profile of an object. After applying a relative displacement between two gratings at a constant velocity, every pixel of CMOS camera can capture a heterodyne moiré signal. The precise phase distribution of the moiré fringes can be extracted using a one-dimensional fast Fourier transform (FFT) analysis on every pixel, simultaneously filtering the harmonic noise of the moiré fringes.

PQ:DMNA/PMMA photopolymer having amazing volume holographic recording at wavelength of insignificant absorption.

N, N-dimethyl-4-nitroaniline doping enables red-light holographic recording that was originally insensitive in thick phenanthrenequinone/poly(methyl methacrylate) photopolymer to have reasonable sensitivity. A volume hologram was recorded by a 647 nm laser with maximum diffraction efficiency of about 43% in a 2-mm-thick sample. A Bragg selectivity curve and an image hologram reconstruction are also demonstrated.

Near-infrared properties of Rh-doped Bi12TiO20 crystals for photonic applications.

The effect of Rh doping in Bi(12)TiO(20) (BTO) crystals on the photosensitivity and recording speed at 1064 nm is reported. Response time of 0.1 s is measured during real-time holographic recording without any preliminary treatments.

Two-Year Evaluation of the X-STOP Interspinous Spacer in Different Primary Patient Populations With Neurogenic Intermittent Claudication Because of Lumbar Spinal Stenosis.

Study Design: Multicenter, prospective single-arm study in patients diagnosed with neurogenic intermittent claudication because of lumbar spinal stenosis.

Objective: To collect data from 2 different primary patient populations, new participants meeting entry criteria [Continued Access Program (CAP)], or subjects who had been randomly assigned to nonsurgical management in the pivotal Investigational Device Exemption study and failed to respond upon study completion [Crossover Study (COS)].

Summary Of Background Data: The X-STOP interspinous spacer is a minimally invasive treatment option for neurogenic intermittent claudication shown to improve pain, physical functioning, and/or overall quality of life.

Quasi-nonvolatile storage in Ru-doped Bi12SiO20 crystals by two-wavelength holography.

Prolonged read-out process of a hologram recorded at near infrared with simultaneous green light exposure is measured in Ru-doped Bi12SiO20 crystal. The experimental results are confirmed by numerical simulations, suggesting two different traps involved in the space-charge transport mechanism. In addition, quasi-permanent holographic recording of image with fast updating speed by using two-wavelength recording is demonstrated.

Thermally activated state transition technique for femto-Newton-level force measurement.

We develop and test a thermally activated state transition technique for ultraweak force measurement. As a force sensor, the technique was demonstrated on a classical Brownian bead immersed in water and restrained by a bistable optical trap. A femto-Newton-level flow force imposed on this sensor was measured by monitoring changes in the transition rates of the bead hopping between two energy states.

Identification of protein domains on major pilin MrkA that affects the mechanical properties of Klebsiella pneumoniae type 3 fimbriae.

The Klebsiella pneumoniae type 3 fimbriae are mainly composed of MrkA pilins that assemble into a helixlike filament. This study determined the biomechanical properties of the fimbriae and analyzed 11 site-directed MrkA mutants to identify domains that are critical for the properties. Escherichia coli strains expressing type 3 fimbriae with an Ala substitution at either F34, V45, C87, G189, T196, or Y197 resulted in a significant reduction in biofilm formation.

Treatment of facet cysts associated with neurogenic intermittent claudication with x-stop.

Background: Facet degeneration often leads to the formation of synovial facet cysts. As facet cysts invade the spinal canal, they become a contributing factor to spinal stenosis. Previous studies have demonstrated successful treatment of neurogenic intermittent claudication (NIC), a major symptom of spinal stenosis, with an interspinous process device.

Oxiplex reduces leg pain, back pain, and associated symptoms after lumbar discectomy.

Study Design: Prospective, randomized, blinded clinical trial.

Objective: To evaluate effectiveness of Oxiplex gel for reduction of pain and associated symptoms after lumbar discectomy.

Summary Of Background Data: Oxiplex gel (carboxymethylcellulose, polyethylene oxide, and calcium) is used during discectomy to coat the surgical site for reduction of pain and symptoms after lumbar discectomy.

Volume polarization holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) photopolymer.

Volume polarization holographic recording in phenanthrenequinone-doped poly (methyl methacrylate) photopolymer is obtained. Photoinduced birefringence in a 2 mm thick sample is measured by a phase-modulated ellipsometry. The birefringence induced in this material by linearly polarized beam at 514 nm reaches 1.

Real-time holography in ruthenium-doped bismuth sillenite crystals at 1064 nm.

Real-time holographic recording and an improvement of the response time in ruthenium (Ru)-doped Bi(12)SiO(20) (BSO) crystal at 1064 nm is obtained. Using green light pre-exposure, a significant operation speed of 60 ms is achieved. In addition, the ability for image reconstruction is demonstrated in Ru-doped BSO, supporting further applications as reversible media for real-time image processing at the near-IR spectral range.

Scoliosis and interspinous decompression with the X-STOP: prospective minimum 1-year outcomes in lumbar spinal stenosis.

Background Context: The X-STOP interspinous decompression device, as a treatment for neurogenic intermittent claudication (NIC) because of lumbar spinal stenosis (LSS), has been shown to be superior to nonoperative control treatment. Current Food and Drug Administration labeling limits X-STOP use to NIC patients with a maximum of 25° concomitant lumbar scoliosis. This value was arrived at arbitrarily by the device developers and is untested.

Stochastic transfer function for structured illumination microscopy.

The stochastic transfer function extends the concept of the conventional transfer function by incorporating noise statistics, thus giving a measure of the signal-to-noise ratio at each spatial frequency. This provides a convenient and standardized metric to assess the trade-off in terms of spatial frequency bandwidth and signal-to-noise ratio for a diverse range of resolution enhancement techniques. We apply this concept to structured illumination microscopy and compare its noise performance as a function of frequency with the conventional wide-field fluorescent microscope.

Stochastic transfer function: application to fluorescence microscopy.

We develop the concept of the stochastic transfer function (STF) and its application to high-resolution fluorescence microscopy. The STF is directly related to the conventional optical transfer functions but incorporates a probability density function at each spatial frequency. The mean of the STF yields the conventional transfer function; the variance of the STF gives a measure of the noise associated at each spatial frequency.

Resolution in structured illumination microscopy: a probabilistic approach.

Structured illumination can be employed to extend the lateral resolution of wide-field fluorescence microscopy. Since a structured illumination microscopy image is reconstructed from a series of several acquired images, we develop a modified formulation of the imaging response of the microscope and a probabilistic analysis to assess the resolution performance. We use this model to compare the fluorescence imaging performance of structured illumination techniques to confocal microscopy.