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To evaluate the associations among the validated lumbar vertebral bone quality (VBQ) score, and cervical and thoracic VBQ scores.Radiographic records of 100 patients who underwent synchronous MRI of the cervical, thoracic, and lumbar spine were retrieved. DEXA-validated lumbar VBQ was calculated using median signal intensity (MSI) of the L1-L4 vertebrae and L3 CSF. VBQ was derived as the quotient of MSIMean cervical, thoracic, and lumbar VBQ scores were 3.06 ± 0.89, 2.60 ± 0.77, and 2.47 ± 0.61, respectively. Mean differences of .127 (p = 0.045) and - 0.595 (p 0.001) were observed between thoracic and lumbar, and cervical and lumbar VBQ scores. Correlations of 0.324, 0.356, and 0.600 (p 0.001) were found between cervical and lumbar, cervical and thoracic, and thoracic and lumbar VBQ scores. Regression with ANOVA predicting lumbar VBQ in relation to cervical and thoracic VBQ demonstrated R Square values of 0.105 and 0.360 (p 0.001), and β coefficient values of 0.471 and 0.217 (p 0.001), respectively.Thoracic VBQ provides values representative of the validated lumbar VBQ score. Cervical VBQ scores are distinct from lumbar VBQ scores and do not provide adequate surrogate values of lumbar VBQ.

BACKGROUND: Determine effects of pre-operative opiate use on anterior cervical discectomy and fusion (ACDF) surgery outcomes. METHODS: The study design was a single center retrospective cohort study. Patient records were reviewed from 2013 and 2018 for elective 1 to 2 level ACDF surgeries. Patients were classified as: opiate naive (ON: no history of opiate) use, acute opiate (AO

To assess the intra- and inter-observer reliability of the novel vertebral bone quality (VBQ) scoring system.Four orthopedic surgery residents at various levels of training (PGY1-4) evaluated 100 noncontrast, T1-weighted MRIs of the lumbar spine. VBQ was calculated as quotient of the median of L1-L4 average signal intensity (SI) and the L3 cerebral spinal fluid (CSF) SI, as described by Ehresman et al. All measurements were repeated 2 weeks later. We performed a stratified analysis based on patient history of instrumentation, pathology, and MRI manufacturer/magnet strength to determine their effect on VBQ reliability. Spinal pathologies included compression fracture, burst fracture, vertebral osteomyelitis, epidural abscess, or neoplasm. The interclass correlation coefficient (ICC) two-way mixed model on absolute agreement was used to analyze inter-rater and intra-rater reliability. ICC less than 0.40 was considered poor, 0.40-0.59 as fair, 0.60-0.74 as good, and greater than 0.75 as excellent.Intra-observer reliability was excellent (≥ 0.75) for all four observers. When stratified by history of spinal instrumentation or spinal pathology, all raters showed excellent intra-observer reliability except one (0.71 and 0.69, respectively). When stratified by MRI manufacturer, intra-observer reliability was ≥ 0.75 for all raters. Inter-observer reliability was excellent (0.91) and remained excellent (≥ 0.75) when stratified by history of spinal instrumentation, spinal pathology, or MRI-manufacturer.VBQ scores from spine lumbar MRIs demonstrate excellent intra-observer and inter-observer reliability. These scores are reliably reproduced in patients regardless of previous instrumentation, spinal pathology, or MRI manufacturer/magnetic field strength.

Objectives The objective of this retrospective cohort study was to evaluate the associations among preoperative cannabis use, postoperative opioid use, and postoperative outcomes following elective anterior cervical decompression and fusion (ACDF). Methods Patients who underwent one- or two-level ACDF were characterized preoperatively as active cannabis users, former users, or nonusers. Patients were also classified based on history of preoperative opioid use as chronic users, acute users, or nonusers. Groups were compared based on outcomes including the rate of emergency department visits six months postoperatively, rate of readmissions one year postoperatively, rate of reoperation two years postoperatively, and daily postoperative opioid use measured in milligram morphine equivalents (MMEs) at 0-6 months and 6-12 months postoperatively. Results Of the 198 patients included in this study, 13 (6.6%) were active cannabis users, 11 (5.6%) were former users, and 174 (87.8%) were nonusers. The rate of reoperation within two years was 23.1% for active cannabis users, 0% for former users, and 4.0% for nonusers (p

Random Forest (RF) is a widely used machine learning algorithm that can be utilized for identification of patient characteristics important for outcome prediction. Posterior cervical decompression with instrumented fusion (PCDF) is a procedure for the management of cervical spondylosis, cervical spinal stenosis, and degenerative disorders that can cause cervical myelopathy or radiculopathy. An RF algorithm was employed to predict and describe length of stay (LOS), readmission, reoperation, transfusion, and infection rates following elective PCDF using The American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database 2008 through 2018. The RF algorithm was tasked with determining the importance of independent clinical variables in predicting our outcomes of interest and importance of each variable based on the reduction in the Gini index. Application of an RF algorithm to the ACS-NSQIP database yielded a highly predictive set of patient characteristics and perioperative events for five outcomes of interest related to elective PCDF. These variables included postoperative infection, increased age, BMI, operative time, and LOS, and decreased preoperative hematocrit and white blood cell count. Risk factors that were predictive for rate of reoperation, readmission, hospital length of stay, transfusion requirement, and post-operative infection were identified with AUC values of 0.781, 0.791, 0.781, 0.902, and 0.724 respectively. Utilization of these findings may assist in risk analysis during the perioperative period and may influence clinical or surgical decision-making.

BACKGROUND: As the prevalence and associated health care costs of osteoporosis continue to rise in our aging population, there is a growing need to continue to identify methods to predict spine construct integrity accurately and cost-effectively. Dual-energy x-ray absorptiometry (DEXA) in both anterior to posterior (AP) and lateral planes, as well as computed tomography (CT) Hounsfield units (HU), have all been investigated as potential preoperative predictive tools. The purpose of this study is to determine which of the 3 bone density analysis modalities has the highest potential for predicting pedicle screw biomechanics. METHODS: Lumbar spine specimens (L2, L3, and L4) from 6 fresh frozen cadavers were used for testing. AP-DEXA, lateral-DEXA, and CT images were obtained. Biomechanical testing of pedicle screws in each vertebrae was then performed including pullout strength and fatigue testing. Statistical analysis was performed. RESULTS: Pullout strength was best predicted by CT HU, followed by AP-DEXA, then lateral-DEXA (R (2) = 0.78, 0.70, and 0.40, respectively). Fatigue testing showed a significant correlation of relative rotation between HU value and AP-DEXA bone mineral density (R (2) = 0.54 and R (2) = 0.72, respectively), and there was a significant correlation between relative translation and HU value (R (2) = 0.43). There was a poor correlation between relative rotation and lateral-DEXA (R (2) = 0.13) as well as a poor correlation between relative translation and both AP- and lateral-DEXA (R (2) = 0.35 and R (2) = 0.02). CONCLUSIONS: CT is the only modality with a statistically significant correlation to all biomechanical parameters measured (pullout strength, relative angular rotation, and relative translation). AP-DEXA also predicts the biomechanical measures of screw pullout and relative angular rotation and is superior to lateral-DEXA. CT may provide an incremental benefit in assessing fatigue strength, but this should be weighed against the disadvantages of cost and radiation. CLINICAL RELEVANCE: The results of this study can help to inform clinicians on different bone density analyses and their implications on pedicle screw failure.

An electron beam is deflected when it passes over a silicon nitride surface, if the surface is illuminated by a low-power continuous-wave diode laser. A deflection angle of up-to $1.2 \,\textrm{mrad}$ is achieved for an electron beam of $29 \,\mu\textrm{rad}$ divergence. A mechanical beam-stop is used to demonstrate that the effect can act as an optical electron switch with a rise and fall time of $6 \,\mu\textrm{s}$. Such a switch provides an alternative means to control electron beams, which may be useful in electron lithography and microscopy.

In this paper we present an analysis of the spin behavior of electrons propagating through a laser field. We present an experimentally realizable scenario in which spin-dependent effects of the interaction between the laser and the electrons are dominant. The laser interaction strength and incident electron velocity are in the nonrelativistic domain. This analysis may thus lead to novel methods of creating and characterizing spin-polarized nonrelativistic femtosecond electron pulses.

Photoelectron field emission, induced by femtosecond laser pulses focused on metallic nanotips, provides spatially coherent and temporally short electron pulses. The properties of the photoelectron yield give insight into both the material properties of the nanostructure and the exciting laser focus. Ultralong nanoribbons, grown as a single crystal attached to a metallic taper, are sources of electron field emission that have not yet been characterized. In this report, photoemission from gold nanoribbon samples is studied and compared to emission from tungsten and gold tips. We observe that the emission from sharp tips generally depends on one transverse component of the exciting laser field, while the emission of a blunted nanoribbon is found to be sensitive to both components. We propose that this property makes photoemission from nanoribbons a candidate for position-sensitive detection of the longitudinal field component in a tightly focused beam.

A point source interferometer (PSI) is a device where atoms are split and recombined by applying a temporal sequence of Raman pulses. During the pulse sequence, an initially trapped cloud of cold atoms is released and allowed to expand, behaving approximately as a point source. The PSI can work as a sensitive multi-axes gyroscope that can automatically filter out the signal from accelerations. The phase shift arising from rotations is proportional to the momentum transferred to each atom from the Raman pulses. Therefore, by increasing the momentum transfer, it should be possibly to enhance the sensitivity of the PSI. Here, we investigate the degree of enhancement in sensitivity that could be achieved by augmenting the PSI with large momentum transfer (LMT) employing a sequence of many Raman pulses with alternating directions. Contrary to typical approaches used for describing a PSI, we employ a model under which the motion of the center of mass of each atom is described quantum mechanically. We show how increasing Doppler shifts lead to imperfections, thereby limiting the visibility of the signal fringes, and identify ways to suppress this effect by increasing the effective, two-photon Rabi frequencies of the Raman pulses. Considering the effect of spontaneous emission, we show that for a given value of the one-photon Rabi frequency, there is an optimum value for the number of pulses employed, beyond which the net enhancement in sensitivity begins to decrease. For a one-photon Rabi frequency of 200 MHz, for example, the peak value of the factor of enhancement in sensitivity is ~39, for a momentum transfer that is ~69 times as large as that for a conventional PSI. We also find that this peak value scales as the one-photon Rabi frequency to the power of 4/5.

Decoherence is associated with a dissipative environment as described by the Caldeira-Leggett equation. Anglin and Zurek predicted that a resistive surface could act as such a dissipative environment for a free electron wave passing close to it. We scrutinize Zurek's and other promising decoherence theoretical models by observing electrons passing by an optically excited GaAs surface and through a gold channel. The high resistivity of the GaAs surface and close proximity to the gold surface leads to strong decoherence within these decoherence models. In contradistinction, the observed contrast is high in our electron diffraction patterns. This implies lower decoherence rates than suggested by these models, making electron-matter-wave-guides and other technologies, where quantum coherence of electrons close to materials is important, a possibility, Comment: 11 pages, 7 figures

Harmonic oscillators count among the most fundamental quantum systems with important applications in molecular physics, nanoparticle trapping, and quantum information processing. Their equidistant energy level spacing is often a desired feature, but at the same time a challenge if the goal is to deterministically populate specific eigenstates. Here, we show how interference in the transition amplitudes in a bichromatic laser field can suppress the sequential climbing of harmonic oscillator states (Kapitza-Dirac blockade) and achieve selective excitation of energy eigenstates, Schr\"{o}dinger cats and other non-Gaussian states. This technique can transform the harmonic oscillator into a coherent two-level system or be used to build a large-momentum-transfer beam splitter for matter-waves. To illustrate the universality of the concept, we discuss feasible experiments that cover many orders of magnitude in mass, from single electrons over large molecules to dielectric nanoparticles.

High-intensity focused ultrasound (HIFU) is a noninvasive thermoablative therapeutic technique that utilizes focused ultrasound beams to target and thermally heat tissue. It has been applied in the treatment of a variety of clinical conditions, including uterine fibroids, prostate cancer, bone metastases, kidney tumors, breast lesions, and, most recently, neurologic disorders such as essential tremor. This chapter focuses on the experience to date in treating disorders of the genitourinary tract using HIFU.

The interference pattern in electron double-slit diffraction is a hallmark of quantum mechanics. A long standing question for stochastic electrodynamics (SED) is whether or not it is capable of reproducing such effects, as interference is a manifestation of quantum coherence. In this study, we use excited harmonic oscillators to directly test this quantum feature in SED. We use two counter-propagating dichromatic laser pulses to promote a ground-state harmonic oscillator to a squeezed Schr��dinger cat state. Upon recombination of the two well-separated wavepackets, an interference pattern emerges in the quantum probability distribution but is absent in the SED probability distribution. We thus give a counterexample that rejects SED as a valid alternative to quantum mechanics.

We provide support for the claim that momentum is conserved for individual events in the electron double slit experiment. The natural consequence is that a physical mechanism is responsible for this momentum exchange, but that even if the fundamental mechanism is known for electron crystal diffraction and the Kapitza-Dirac effect, it is unknown for electron diffraction from nano-fabricated double slits. Work towards a proposed explanation in terms of particle trajectories affected by a vacuum field is discussed. The contentious use of trajectories is discussed within the context of oil droplet analogues of double slit diffraction., Comment: 15 pages, 11 figures

Employing a fully quantized model for atomic wave-packets, we show that a large momentum transfer, multi-axes gyroscope using point-source atomic interferometry (PSAI) can achieve a sensitivity much higher than that of a conventional PSAI gyroscope.

Genetic variation influences how the genome is interpreted in individuals and in mouse strains used to model immune responses. We developed approaches to utilize next-generation sequencing datasets to identify sequence variation in genes and enhancer elements in congenic and backcross mouse models. We defined genetic variation in the widely used B6-CD45.2 and B6.SJL-CD45.1 congenic model, identifying substantial differences in SJL genetic content retained in B6.SJL-CD45.1 strains on the basis of the vendor source of the mice. Genes encoding PD-1, CD62L, Bcl-2, cathepsin E, and Cxcr4 were within SJL genetic content in at least one vendor source of B6.SJL-CD45.1 mice. SJL genetic content affected enhancer elements, gene regulation, protein expression, and amino acid content in CD4+ T helper 1 cells, and mice infected with influenza showed reduced expression of Cxcr4 on B6.SJL-CD45.1 T follicular helper cells. These findings provide information on experimental variables and aid in creating approaches that account for genetic variables.

Dysregulation of the JAK/STAT signaling pathway is associated with Multiple Sclerosis (MS) and its mouse model, Experimental Autoimmune Encephalomyelitis (EAE). Suppressors Of Cytokine Signaling (SOCS) negatively regulate the JAK/STAT pathway. We previously reported a severe, brain-targeted, atypical form of EAE in mice lacking Socs3 in myeloid cells (Socs3ΔLysM), which is associated with cerebellar neutrophil infiltration. There is emerging evidence that neutrophils are detrimental in the pathology of MS/EAE, however, their exact function is unclear. Here we demonstrate that neutrophils from the cerebellum of Socs3ΔLysM mice show a hyper-activated phenotype with excessive production of reactive oxygen species (ROS) at the peak of EAE. Neutralization of ROS in vivo delayed the onset and reduced severity of atypical EAE. Mechanistically, Socs3-deficient neutrophils exhibit enhanced STAT3 activation, a hyper-activated phenotype in response to G-CSF, and upon G-CSF priming, increased ROS production. Neutralization of G-CSF in vivo significantly reduced the incidence and severity of the atypical EAE phenotype. Overall, our work elucidates that hypersensitivity of G-CSF/STAT3 signaling in Socs3ΔLysM mice leads to atypical EAE by enhanced neutrophil activation and increased oxidative stress, which may explain the detrimental role of G-CSF in MS patients.

Dysregulation of the JAK/STAT signaling pathway is associated with multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). Suppressors of cytokine signaling (SOCS) negatively regulate the JAK/STAT pathway. We previously reported a severe, brain-targeted, atypical form of EAE in mice lacking Socs3 in myeloid cells (Socs3(ΔLysM)), and that this atypical EAE is associated with cerebellar neutrophil infiltration. There is emerging evidence that neutrophils are detrimental in the pathology of MS/EAE; however, their exact function is unclear. Here we demonstrate that neutrophils from the cerebellum of Socs3(ΔLysM) mice show a hyperactivated phenotype with excessive production of reactive oxygen species (ROS) at the peak of EAE. Neutralization of ROS in vivo delayed the onset and reduced severity of atypical EAE. Mechanistically, Socs3-deficient neutrophils exhibited enhanced signal transducer and activator of transcription 3 (STAT3) activation, a hyperactivated phenotype in response to granulocyte colony–stimulating factor (G-CSF), and upon G-CSF priming, increased ROS production. Neutralization of G-CSF in vivo significantly reduced the incidence and severity of the atypical EAE phenotype. Overall, our work elucidates that hypersensitivity of G-CSF/STAT3 signaling in Socs3(ΔLysM) mice leads to atypical EAE by enhanced neutrophil activation and increased oxidative stress, which may explain the detrimental role of G-CSF in MS patients.

A point source interferometer (PSI) is a device where atoms are split and recombined by applying a temporal sequence of Raman pulses during the expansion of a cloud of cold atoms behaving approximately as a point source. The PSI can work as a sensitive multi-axes gyroscope that can automatically filter out the signal from accelerations. The phase shift arising from the rotations is proportional to the momentum transferred to each atom from the Raman pulses. Therefore, by increasing the momentum transfer, it should be possible to enhance the sensitivity of the PSI. Here, we investigate the degree of enhancement in sensitivity that could be achieved by augmenting the PSI with large momentum transfer (LMT) employing a sequence of many Raman pulses with alternating directions. We analyze how factors such as Doppler detuning, spontaneous emission, and the finite initial size of the atomic cloud compromise the advantage of LMT and how to find the optimal momentum transfer under these limitations, with both the semi-classical model and a model under which the motion of the center of mass of each atom is described quantum mechanically. We identify a set of realistic parameters for which LMT can improve the PSI by a factor of nearly 40.