Scanning mirror based higher order Bessel-gaussian beams integrated in time (HOBBIT) with applications toward the photoacoustic effect.

We demonstrate a new method for the generation of beams with rapidly tunable orbital angular momentum (OAM). This method is based on using a single-axis scanning galvanometer mirror to add a phase tilt on an elliptical Gaussian beam that is then wrapped to a ring using optics that perform a log-polar transformation. This system can switch between modes in the kHz range and use relatively high power with high efficiency. This scanning mirror HOBBIT system was applied to a light/matter interaction application using the photoacoustic effect, with a 10 dB enhancement of the generated acoustics at a glass/water interface.

High data-rate communication link supported through the exploitation of optical channels in a characterized turbulent underwater environment.

Underwater turbulence presents a myriad of challenges for underwater optical systems through wavefront distortion and beam deflection. In this work, an underwater turbulence emulator is developed and thoroughly characterized to experimentally test the proposed underwater turbulence mitigation technique. This technique applies a modified HOBBIT system introduced in atmospheric turbulence to the relatively unknown underwater turbulence domain. By varying a beam's spatial position and relative phase gradient, a volume of turbulence is rapidly probed to determine the beam state for optimal propagation. This probe and control method is applied in multiple facets, including improved optical power transmission as well as supporting a 25-Gbps communication link through a dynamic environment.

Continuing Chronic Buprenorphine Perioperatively is Associated With Reduced Postoperative Opioid Use.

INTRODUCTION: Buprenorphine is a frequently used medication for opioid use disorder and misunderstanding buprenorphine's unique pharmacology has historically complicated perioperative analgesia. The purpose of this study was to evaluate the association of perioperative buprenorphine continuation in patients with substance use disorder on perioperative opioid use. MATERIALS AND METHODS: This was a single-center retrospective study at a level 1 trauma academic medical center. Adult patients using outpatient buprenorphine for medication for opioid use disorder admitted with an operating room booking were included. Patients were grouped (continuation, withheld) retrospectively based upon the decision to continue or omit buprenorphine therapy while admitted. The primary outcome of the study was any use of full mu-opioid agonists during days 1-7 of admission. Secondary outcomes included length of stay and average pain scores during days 1-7 of admission. RESULTS: 43.4% of patients in the continuation cohort used no full mu-opioid agonists during days 1-7 compared to 3.1% of patients in the withheld cohort (P < 0.001). No significant difference in median length of stay was noted (4.7 d [2.8-6.6] versus 6.1 d [4.0-8.2], P = 0.36). There was no statistical difference in average pain scores on postoperative days 1 (5.2 versus 6.9, P = 0.82) and 7 (0 versus 0, P = 0.41). CONCLUSIONS: Perioperative continuation of buprenorphine is associated with reduced use of alternative full mu-opioid agents while admitted without impacting pain scores.

MRI characteristics of canine prostatic neoplasia.

Magnetic resonance imaging (MRI) has been used to evaluate dogs with suspected prostatic neoplasia, however, published studies describing MRI characteristics of canine prostatic neoplasia are currently lacking. The aims of the current retrospective case series study were to describe MRI findings of the pelvic region in dogs with a histopathologic or cytologic diagnosis of prostatic neoplasia. Retrospective analysis of these images was then performed by a board-certified veterinary radiologist for shared imaging characteristics. The most consistent characteristics were heterogeneous hyperintensity of the tumor on T2-weighted images (10/10) and short tau inversion recovery images (10/10), prostatic capsular margin distortion by the tumor (10/10), cavitations (10/10), complete effacement of the prostatic architecture (9/10), neurovascular bundle (NVB) compression or invasion (9/10), heterogeneous isointensity of the tumor on T1-weighted images (9/10), and strong contrast enhancement of the tumor (8/10). Additional features included an overlying pattern of distorted radiating striations (7/10), regional lymphadenomegaly (5/10), mineralization within the mass (5/10), urinary bladder trigone involvement (6/10), and post-prostatic urethral involvement (7/10). These findings supported the use of MRI as an adjunct imaging modality for diagnosis and therapeutic planning of prostatic neoplasia and including prostatic neoplasia as a likely differential diagnosis for dogs with these MRI characteristics.

Remote sensing using a spatially and temporally controlled asymmetric perfect vortex basis generated with a 2D HOBBIT.

Orbital angular momentum (OAM) is a potential tool for remote sensing applications since amplitude/phase distributions can be decomposed into an OAM basis for analysis. We demonstrate the generation of a spatially asymmetric perfect vortex (APV) basis based on a pulsed 2D HOBBIT (Higher Order Bessel Beams Integrated in Time) system using two acousto-optic deflectors and optical coordinate transformation optics. Results are demonstrated for numerous radii and OAM charges as high as 20, with switching speeds greater than 400 kHz. The spatial APV basis is used to design different types of pulse trains for amplitude object pattern recognition and phase object wavefront sensing. Experimental results of sensing are provided for an amplitude object and a phase object to demonstrate the feasibility of the spatial APV on remote sensing tasks.

OAM-based optical wavelet using a single pixel detection system for probing dynamic environments with application to real-time measurements of strong atmospheric turbulence.

This paper presents a novel method for optical probing by generating optical fields with characteristics of wavelets. The optical wavelets form a basis of rotated asymmetric beams with scaled orbital angular momentum (OAM) and beam sizes. The probing method was used experimentally to measure the continuous wavelet transform of a turbulent propagation path, giving insight into the angular properties about a fixed radius. The wavelet transform of a three-dimensional turbulence distribution was measured; the measurements are much faster than the turbulence changes, allowing characterization of an instantaneous realization of turbulence over time. Results show highly localized regions of OAM in space through the turbulence and characteristics of the turbulence can be extracted from the wavelet transforms.

Sensing and coupling of optical channels in dynamic atmospheric turbulence using OAM beamlets for improved power and data transmission.

Propagation of laser light is distorted in the presence of atmospheric turbulence. This poses an issue for sensing, free-space optical communications, and transmission of power. The presented system offers a novel solution to mitigate the effects of turbulence. By rapidly probing a turbulent volume by varying a beam's spatial and phase characteristics, the best transmission mode can be determined and updated in real time. Unlike a traditional tip-tilt system, this scheme is fully electronic, and has a scalable architecture to leverage multiple optical transmission paths simultaneously. This optical control system greatly improves power efficiency and successful recovery of data through environments with strong turbulence.

Thoracoscopic detection of thoracic ducts after ultrasound-guided intrahepatic injection of indocyanine green detected by near-infrared fluorescence and methylene blue in dogs.

OBJECTIVE: To describe and compare onset and intensity of thoracic duct (TD) coloration in healthy dogs after intrahepatic injection of either indocyanine green (ICG) visualized by intraoperative near-infrared fluorescence lymphography (NIRFL) or direct thoracoscopic visualization of methylene blue dye (MB). STUDY DESIGN: Prospective study. ANIMALS: Healthy adult Beagle dogs (n = 5). METHODS: All dogs had biochemical panels and complete blood counts preoperatively. Computed tomography lymphography (CTL) was performed prior to a standard 3-port thoracoscopic approach. A mixture of MB and ICG was injected by ultrasound-guided percutaneous injection into right or left-sided hepatic lobes. Data collected included dose of contrast agent (MB vs. ICG), injection site, timing, and quality of operative TD identification. Potential hepatic injury was assessed by repeat laboratory evaluation and abdominal ultrasound 14 days postoperatively. RESULTS: Preoperative CTL provided a diagnostic study in 5/5 dogs. After intrahepatic injection of combined dyes, NIRFL allowed visualization of TDs in 5/5 dogs, but MB did not result in visible TD coloration in any dog. Intrahepatic injection of ICG achieved successful NIRFL in a median time of 6 minutes and persisted for the 20 minute observation period in all five dogs. All dogs recovered without complication and were subsequently adopted. CONCLUSION: NIRFL of the TD can be achieved with intraoperative hepatic injection of ICG. Intrahepatic injection of MB did not result in visible TD coloration. CLINICAL SIGNIFICANCE: Hepatic intra-parenchymal injection is a reliable alternative portal into the TD system for intraoperative visualization of TD anatomy using ICG in dogs.

Effects of a walking program in patients with chronic unilateral vestibular hypofunction.

[Purpose] Patients with chronic unilateral vestibular hypofunction show decreased postural stability and low levels of physical activity and also experience much anxiety. Physical activity is known to improve these symptoms; however, no study has reported any positive effects of physical activity, such as symptom reduction or improvement in function in these patients. In this study, we investigated the role of a walking program in improvement of dizziness, anxiety, and postural stability in this patient population. [Participants and Methods] This study included 21 patients with unilateral vestibular hypofunction and chronic dizziness. Patients were instructed to walk 30 min daily for 3 months. Physical activity levels and questionnaires for clinical symptoms, anxiety, and postural stability were evaluated before and after intervention. [Results] We observed significant differences in the amount of moderate-to-vigorous physical activity, clinical symptoms, and self-perceived handicap before and after the intervention. Additionally, anxiety levels were significantly reduced and postural stability was significantly improved in these patients. [Conclusion] A walking program improved physical activity levels, clinical symptoms, and postural stability and reduced self-perceived handicap and anxiety in patients with chronic unilateral vestibular hypofunction. These results highlight the effectiveness of a walking program for these patients and emphasize its role as a complementary vestibular rehabilitation strategy.

Spatio-temporal controlled filamentation using higher order Bessel-Gaussian beams integrated in time.

We demonstrate a new method for a systematic, dynamic, high-speed, spatio-temporal control of femtosecond light filamentation in BK7 as a particular example of nonlinear medium. This method is based on using coherent conjugate asymmetric Bessel-Gaussian beams to control the far-field intensity distribution and in turn control the filamentation location. Such spatio-temporal control allows every femtosecond pulse to have a unique intensity distribution that results in the generation of structured filamentation patterns on demand. The switching speed of this technique is dependent on the rise time of the acousto-optic deflector, which can operate in the MHz range while having the ability to handle high peak power pulses that are needed for nonlinear interactions. The proposed and demonstrated spatio-temporal control of structured filaments can enable generation of large filament arrays, opto-mechanical manipulations of water droplets for fog clearing, as well as engineered radiofrequency plasma antennas.

Fractional orbital angular momentum conversion in second-harmonic generation with an asymmetric perfect vortex beam.

This Letter demonstrates the nonlinear conversion of asymmetric perfect vortex (APV) beams with fractional orbital angular momentum (OAM). By controlling the amplitude and phase of the fundamental light field, we create APVs whose global OAM demonstrates a one-to-one correspondence of the charge numbers for fractional OAM values. The results show that the OAM of the second-harmonic generation fields follow the OAM conservation law. The nonlinear interactions of multiple OAM beams with the APVs are also investigated as they relate to the nonlinear frequency conversion and are shown to exhibit unique frequencies as a result of the Doppler frequency tagged OAM values.

Naloxone Continuous Infusion for Spinal Cord Protection in Endovascular Aortic Surgery Leads to Higher Opioid Administration and More Pain.

OBJECTIVE: Compare total perioperative opioid use in patients receiving naloxone continuousinfusion (NCI) for spinal cord ischemia prophylaxis, versus patients not receiving NCI, in endovascular aortic repair. DESIGN: Single-center, retrospective cohort review. SETTING: Academic medical center. PARTICIPANTS: Patients undergoing elective thoracic, thoracoabdominal, or abdominal aortic endovascular repair. INTERVENTIONS: Patients were separated based on the use of naloxone continuous infusion as part of a spinal protection protocol. Primary endpoint was opioid requirements, in milligram morphine equivalents (MME), during the first 48 hours or during NCI. Secondary endpoints included: postoperative pain scores during the same interval; opioid requirements during hours 48 to 72; and pain scores during hours 48 to 72. MEASUREMENTS AND MAIN RESULTS: Ninety-five procedures were included; 43 received naloxone continuous infusion and 52 patients were in the non-naloxone group. Opioid use from a linear mixed model was elevated across the entire continuum in the naloxone group (18 MMEs, 95% CI 13-24), with the greatest difference seen at the 24-to-48-hour interval (51 MMEs, 95% CI 26-75) after adjustment for age, incisions, and prehospital opioid use. In the naloxone group, pain score estimates were elevated at each postoperative interval of evaluation, with similar adjustment. Across the continuum this was 0.7 higher (95% CI 0.2-1.3); the zero-six-hour and six-to-12-hour intervals were 0.9 (95% CI 0.4-1.4) and 1.2 higher (95% CI 0.7-1.7). CONCLUSIONS: Patients receiving anloxone continuous infusion to prevent spinal cord ischemia required greater quantities of opioids and had higher postoperative pain, compared with patients not requiring naloxone.

Whole genome variant association across 100 dogs identifies a frame shift mutation in DISHEVELLED 2 which contributes to Robinow-like syndrome in Bulldogs and related screw tail dog breeds.

Domestic dog breeds exhibit remarkable morphological variations that result from centuries of artificial selection and breeding. Identifying the genetic changes that contribute to these variations could provide critical insights into the molecular basis of tissue and organismal morphogenesis. Bulldogs, French Bulldogs and Boston Terriers share many morphological and disease-predisposition traits, including brachycephalic skull morphology, widely set eyes and short stature. Unlike other brachycephalic dogs, these breeds also exhibit vertebral malformations that result in a truncated, kinked tail (screw tail). Whole genome sequencing of 100 dogs from 21 breeds identified 12.4 million bi-allelic variants that met inclusion criteria. Whole Genome Association of these variants with the breed defining phenotype of screw tail was performed using 10 cases and 84 controls and identified a frameshift mutation in the WNT pathway gene DISHEVELLED 2 (DVL2) (Chr5: 32195043_32195044del, p = 4.37 X 10-37) as the most strongly associated variant in the canine genome. This DVL2 variant was fixed in Bulldogs and French Bulldogs and had a high allele frequency (0.94) in Boston Terriers. The DVL2 variant segregated with thoracic and caudal vertebral column malformations in a recessive manner with incomplete and variable penetrance for thoracic vertebral malformations between different breeds. Importantly, analogous frameshift mutations in the human DVL1 and DVL3 genes cause Robinow syndrome, a congenital disorder characterized by similar craniofacial, limb and vertebral malformations. Analysis of the canine DVL2 variant protein showed that its ability to undergo WNT-induced phosphorylation is reduced, suggesting that altered WNT signaling may contribute to the Robinow-like syndrome in the screwtail breeds.

Real-time OAM cross-correlator based on a single-pixel detector HOBBIT system.

The creation and detection of spatial modes of light with transient orbital angular momentum (OAM) properties is of critical importance in a number of applications in sensing and light matter interactions. Most methods are limited in their frequency response as a result of their modulation techniques. In this paper, a new method is introduced for the coherent detection of transient properties of OAM using a single pixel detector system for the creation of an OAM spectrogram. This technique is based on the ideas utilized in acousto-optic based optical correlators with log-polar optical elements for the creation and detection of higher order bessel beams integrated in time (HOBBIT) at MHz data rates. Results are provided for beams with time varying OAM, coherent combinations, and transient scattering by phase objects.

Experimental probing of turbulence using a continuous spectrum of asymmetric OAM beams.

Propagation of a continuous spectrum of orbital angular momentum (OAM) states through a realistic and controlled 3-dimensional turbulent condition has not been studied to date to the authors' knowledge. Using the Higher Order Bessel-gauss Beams Integrated in Time (HOBBIT) system and a 60 meter optical path Variable Turbulence Generator (VTG), we demonstrate that by changing the OAM in a continuous scan, a spectrum of OAMs provide an opportunity to take advantage of additional propagation channels within the aperture of the transmitter and optical path to the receiver. Experimental results are provided illustrating the HOBBIT system's ability to position the beam in space and time to exploit eigenchannels in the turbulent medium. This technique can be used to probe the turbulence at time scales much faster than the Greenwood frequency.

Second-harmonic generation of asymmetric Bessel-Gaussian beams carrying orbital angular momentum.

Nonlinear processes of laser beams carrying orbital angular momentum (OAM) offer a means to generate new wavelengths and to manipulate OAM charge numbers. We demonstrate the second-harmonic generation (SHG) of asymmetric Bessel-Gaussian (BG) beams carrying OAM of both integer and fractional charge numbers. Experimental results show a good one-to-one correspondence of the charge numbers and compliance with the OAM conservation law. The SHG conversion process and efficiency with different combined charge numbers are also discussed.

Percutaneous radiologically guided gastrostomy tubes: Procedural description and biomechanical comparison in a canine model.

OBJECTIVE: To describe the novel placement of percutaneous radiologically guided gastrostomy (PRG) tubes in a canine cadaveric model and to biomechanically compare PRG and percutaneous endoscopic gastrostomy (PEG) tube constructs. STUDY DESIGN: Descriptive and biomechanical experimental study. ANIMALS: Fifteen large breed (>25 kg) canine cadavers. METHODS: Percutaneous endoscopic gastrostomy tubes, low-profile PRG tubes, and standard PRG tubes were each placed in five canine cadavers. Body wall and stomach (with attached gastrostomy tube constructs) were harvested and biomechanically tested. Data regarding the maximal load to failure and procedure time were statistically analyzed. RESULTS: Percutaneous endoscopic gastrostomy and PRG tube placement was successful in all cadavers with no procedure-related complications. Gastrostomy tube placement time was longer for the PEG group vs the low-profile PRG (P = .005) and standard PRG (P = .037) groups. Peak construct strength was lower for the PEG group vs the low-profile PRG (P = .002) and standard PRG (P = .010) groups. The site of failure varied among groups. CONCLUSION: Percutaneous radiologically guided gastrostomy tubes were successfully placed in all cases with shorter placement time and greater peak construct strength compared with PEG tubes. CLINICAL SIGNIFICANCE: Due to the increased load to failure as well as decreased placement time recorded for PRG tubes relative to PEG tubes, PRG tubes may be considered as an alternative minimally invasive gastrostomy option in large breed canine patients. Further evaluation in clinical animals is required. Results of this work were presented at the 2019 American College of Veterinary Surgeons Surgery Summit; October 16-19, 2019; Las Vegas, Nevada.

Ovine Models of Congenital Heart Disease and the Consequences of Hemodynamic Alterations for Pulmonary Artery Remodeling.

The natural history of pulmonary vascular disease associated with congenital heart disease (CHD) depends on associated hemodynamics. Patients exposed to increased pulmonary blood flow (PBF) and pulmonary arterial pressure (PAP) develop pulmonary vascular disease more commonly than patients exposed to increased PBF alone. To investigate the effects of these differing mechanical forces on physiologic and molecular responses, we developed two models of CHD using fetal surgical techniques: 1) left pulmonary artery (LPA) ligation primarily resulting in increased PBF and 2) aortopulmonary shunt placement resulting in increased PBF and PAP. Hemodynamic, histologic, and molecular studies were performed on control, LPA, and shunt lambs as well as pulmonary artery endothelial cells (PAECs) derived from each. Physiologically, LPA, and to a greater extent shunt, lambs demonstrated an exaggerated increase in PAP in response to vasoconstricting stimuli compared with controls. These physiologic findings correlated with a pathologic increase in medial thickening in pulmonary arteries in shunt lambs but not in control or LPA lambs. Furthermore, in the setting of acutely increased afterload, the right ventricle of control and LPA but not shunt lambs demonstrates ventricular-vascular uncoupling and adverse ventricular-ventricular interactions. RNA sequencing revealed excellent separation between groups via both principal components analysis and unsupervised hierarchical clustering. In addition, we found hyperproliferation of PAECs from LPA lambs, and to a greater extent shunt lambs, with associated increased angiogenesis and decreased apoptosis in PAECs derived from shunt lambs. A further understanding of mechanical force-specific drivers of pulmonary artery pathology will enable development of precision therapeutics for pulmonary hypertension associated with CHD.

Rapidly tunable orbital angular momentum (OAM) system for higher order Bessel beams integrated in time (HOBBIT).

Beams with fast and continuously-tunable orbital angular momentum (OAM) have potential applications in classical and quantum optical communications, sensing, and in the study of beam propagation through turbulence. An acousto-optical deflector (AOD) is a sophisticated, well-studied device that continuously and rapidly tunes the deflection angle of an output beam. The log-polar HOBBIT setup can generate beams with OAM by wrapping elliptically shaped Gaussian beams with linear phase tilt to a ring. By combining the linear tilted output from the AOD with the OAM generation capabilities of the HOBBIT system, the generated OAM modes become continuously tunable at high speeds measured on the order of 400 kHz.

Evaluation of a dry therapeutic urinary diet and concurrent administration of antimicrobials for struvite cystolith dissolution in dogs.

BACKGROUND: Struvite urolithiasis with bacterial urinary tract infection (UTI) is commonly reported in dogs; few data exist to describe successful dissolution protocols in dogs with naturally occurring disease. We hypothesized that a dry therapeutic urinary diet combined with targeted antimicrobial therapy can effectively dissolve presumptive struvite cystolithiasis in dogs with naturally occurring urease-producing bacterial UTI. RESULTS: Ten dogs with presumed infection-induced struvite cystolithiasis based on lower urinary tract signs (LUTS), radiodense cystoliths, and urease-producing bacterial UTI were enrolled. At enrollment, antimicrobials and dry therapeutic urinary diet were dispensed. In addition to lack of radiographic resolution of urolithiasis, dogs with persistent clinical signs were considered non-responders. There was no significant difference in pH between responders and non-responders; USG was significantly higher in the responder group. Recheck visits continued until radiographic dissolution or failure was documented. Five of the 10 dogs achieved radiographic dissolution of cystolithiasis within a median of 31 days (range 19-103). In the other 5 dogs, surgical urolith removal was necessary due to persistent LUTS (3 dogs within 2 weeks) or lack of continued dissolution noted radiographically (1 dog with numerous cystoliths failed at day 91; 1 dog failed by day 57 with questionable owner compliance). CONCLUSIONS: Dissolution of urinary tract infection induced struvite cystoliths can be accomplished in some dogs fed this dry therapeutic urinary diet in conjunction with antimicrobial therapy. Case selection could increase the likelihood of successful dissolution; however, if calcium phosphate is present, this could also prevent stone dissolution. If clinical signs persist despite diet and antimicrobials, stone removal is advised.