Neutron interferometry using a single modulated phase grating.

Neutron grating interferometry provides information on phase and small-angle scatter in addition to attenuation. Previously, phase grating moiré interferometers (PGMI) with two or three phase gratings have been developed. These phase-grating systems use the moiré far-field technique to avoid the need for high-aspect absorption gratings used in Talbot-Lau interferometers (TLI) that reduce the neutron flux reaching the detector. We first demonstrate, through theory and simulations, a novel phase grating interferometer system for cold neutrons that requires a single modulated phase grating (MPG) for phase-contrast imaging, as opposed to the two or three phase gratings in previously employed PGMI systems. The theory shows the dual modulation of MPG with a large period and a smaller carrier pitch P, resulting in large fringes at the detector. The theory was compared to the full Sommerfeld-Rayleigh diffraction integral simulator. Then, we proceeded to compare the MPG system to experiments in the literature that use a two-phase-grating-based PGMI with best-case visibility of around 39%. The simulations of the MPG system show improved visibility in comparison to that of the two-phase-grating-based PGMI. An MPG with a modulation period of 300 µm, the pitch of 2 µm, and grating heights with a phase modulation of (π,0, illuminated by a monochromatic beam produces visibility of 94.2% with a comparable source-to-detector distance (SDD) as the two-phase-grating-based PGMI. Phase sensitivity, another important performance metric of the grating interferometer, was compared to values available in the literature, viz. the conventional TLI with the phase sensitivity of 4.5 × 103 for an SDD of 3.5 m and a beam wavelength of 0.44 nm. For a range of modulation periods, the MPG system provides comparable or greater theoretical maximum phase sensitivity of 4.1 × 103 to 10.0 × 103 for SDDs of up to 3.5 m. This proposed MPG system appears capable of providing high-performance PGMI that obviates the need for the alignment of two phase gratings.

Delayed intestinal perforation secondary to blunt force abdominal trauma in a cat.

CASE SUMMARY: A 7-month-old intact male domestic shorthair cat was presented 4 h after being hit by a car. It had bilateral inguinal hernias and a mesenteric rent that were repaired surgically and a hematoma in the left retroperitoneal space. No other intra-abdominal abnormalities were identified on abdominal surgical exploration. Approximately 72 h after presentation, the cat started vomiting and developed severe abdominal discomfort. A sudden decrease in mentation and elevation of respiratory rate and effort ensued. Abdominal radiographs showed loss of detail in the abdominal cavity, and abdominocentesis confirmed septic peritonitis. The cat was euthanized, and post-mortem evaluation of the bowel revealed two 1 cm perforations of the jejunum. RELEVANCE AND NOVEL INFORMATION: To our knowledge, delayed intestinal perforation secondary to blunt force abdominal trauma has not previously been reported in cats. It has been reported in dogs, but the pathophysiology resulting in perforation is poorly understood. Delayed intestinal injury secondary to blunt force abdominal trauma has been reported in people, especially in children, as a result of motor vehicle accidents.

Laryngeal chondronecrosis after radiation therapy in a dog.

A 5-year-old pug presented with a soft tissue swelling on the ventral neck and moderate stridor with associated respiratory effort. This patient received hypofractionated radiotherapy for metastatic upper lip mast cell tumour and to the submandibular lymph nodes 6 months before presentation. Oral examination showed moderate elongation of the soft palate, stage III laryngeal collapse with only the right laryngeal saccule mildly everted and exuberant pale epiglottal and left pharyngeal mucosa. Staphylectomy, resection of the epiglottal mucosa and left arytenoid lateralisation were performed. One day after surgery, temporary tracheostomy was performed after respiratory distress due to the severe laryngeal and pharyngeal oedema. A third oral exam showed pale and redundant caudal pharyngeal mucosa obstructing the rima glottis, soft and collapsible arytenoid cartilage with pale mucosa and bilateral everted laryngeal saccules. Permanent tracheostomy was elected and laryngeal cartilage biopsies were taken. Histologic diagnosis showed cartilage necrosis and abundant tissue oedema. The patient was euthanased 1 week later.

Outcome After Pneumonectomy in 17 Dogs and 10 Cats: A Veterinary Society of Surgical Oncology Case Series.

OBJECTIVE: To report the signalment, presenting clinical signs, surgical complications, histologic diagnosis, postoperative complications, and outcome of dogs and cats undergoing pneumonectomy. STUDY DESIGN: Retrospective case series; multicenter study. ANIMALS: Client-owned dogs (n=17) and cats (n=10). METHODS: Signalment, clinical signs, side affected, surgical data, preoperative diagnostic tests (including complete blood count, serum biochemistry, cytologic diagnosis, chest radiographs, and computed tomography), histologic diagnosis, surgical complications, adjunctive therapy, and date and cause of death were collected from records of dogs and cats that underwent pneumonectomy. Survival estimates and complication were assessed. RESULTS: Seventeen animals had a left-sided pneumonectomy performed (12 dogs, 5 cats) and 10 animals had a right-sided pneumonectomy (5 dogs, 5 cats). Fourteen animals were diagnosed with neoplasia (52%). The overall incidence of complications for dogs and cats were 76 and 80%, respectively, with major complications in 41 and 50%, respectively. Respiratory complications (persistent pleural effusion, oxygen dependence, persistent increased respiratory rate, or coughing) were the most frequent complications. No animals died or were euthanatized intraoperative or within the first 24 hours postoperative. One dog (6%) and 2 cats (20%) died, or were euthanatized in the first 2 weeks postoperative. CONCLUSION: Based on this case series, right and left pneumonectomy can be performed with low perioperative mortality in dogs and cats, with some animals experiencing prolonged survival.

SU-E-T-101: Dosimetry Intercomparison for a Synchrotron-Produced Monochromatic X-Ray Beam.

PURPOSE: This study performed a dosimetry intercomparison for synchrotron-produced monochromatic x-ray beams. Ion chamber depth-dose measurements in a polymethylmethacrylate (PMMA) phantom were compared with the product of MCNP5 Monte Carlo calculations of dose per fluence and measured incident fluence at 25 and 35 keV. The ion chamber measurements are being used to calibrate dose output for cell irradiations designed to investigate photoactivated Auger electron therapy at the LSU Center for Advanced Microstructures and Devices (CAMD) synchrotron facility. METHODS: Monochromatic beams of 25 and 35 keV were generated on the tomography beamline at CAMD. A cylindrical, air-equivalent ion chamber was used to measure the ionization created in a 10×10×10-cm3 PMMA phantom at depths of 0.6 - 7.7 cm. AAPM TG-61 protocol was applied to convert measured ionization into dose. MCNP5 simulations of the irradiation geometry were performed to determine the dose deposition per photon fluence in the phantom. Photon fluence was determined using a NaI detector to make scattering measurements of the beam from a polyethylene target at angles 15 - 60 degrees. Differential Compton and Rayleigh scattering cross sections were used to derive the incident fluence. RESULTS: At 35 keV dose measurements for equal exposures determined using the MCNP5-fluence results underestimated those of the ion chamber by 1.8 - 4.8% for PMMA depths from 0.6 - 7.7 cm, respectively. At 25 keV there was an overestimate of 6.6 - 1.9%. CONCLUSIONS: These results show that TG-61 ion chamber dosimetry, used to calibrate the dose output for the cell irradiations, is accurate within approximately 7% for beam energies 25-35 keV. This research was supported by contract W81XWH-10-1-0005 awarded by The U.S. Army Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702-5014. This report does not necessarily reflect the position or policy of the Government, and no official endorsement should be inferred.

SU-E-T-155: Dose Response Curve of EBT2 and EBT3 Radiochromic Films to a Synchrotron-Produced Monochromatic X-Ray Beam.

PURPOSE: This work investigates the dose-response curves of Gafchromic EBT2 and EBT3 radiochromic films using synchrotron-produced monochromatic x-ray beams. These dosimeters are being utilized for dose verification in photoactivated Auger electron therapy at the LSU Center for Advanced Microstructures and Devices (CAMD) synchrotron facility. METHODS: Monochromatic beams of 25, 30 and 35 keV were generated on the tomography beamline at CAMD. Ion chamber depth-dose measurements were used to calculate the dose delivered to films irradiated simultaneously at depths from 0.7 - 8.5 cm in a 10×10×10-cms polymethylmethacrylate phantom. AAPM TG-61 protocol was applied to convert measured ionization into dose. Calibrations of films at 4 MV were obtained for comparison using a Clinac 21 EX radiotherapy accelerator at Mary Bird Perkins Cancer Center. Films were digitized using an Epson 1680 Professional flatbed scanner and analyzed using the optical density (OD) derived from the red channel. RESULTS: For EBT2 film the average sensitivity (OD/dose) at 50, 100, and 200 cGy relative to that for 4-MV x- rays was 1.07, 1.20, and 1.23 for 25, 30, and 35 keV, respectively. For EBT3 film the average sensitivity was within 3 % of unity for all three monochromatic beams. CONCLUSIONS: EBT2 film sensitivity shows strong energy dependence over an energy range of 25 keV - 4 MV. EBT3 film shows weak energy dependence, indicating that it would be the better dosimeter for Auger electron therapy. This research was supported by contract W81XWH-10-1-0005 awarded by The U.S. Army Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702-5014. This report does not necessarily reflect the position or policy of the Government, and no official endorsement should be inferred.

Effects of long-term estrogen replacement therapy on articular cartilage IGFBP-2, IGFBP-3, collagen and proteoglycan levels in ovariectomized cynomolgus monkeys.

OBJECTIVE: The purpose of this study was to determine the effects of long-term estrogen replacement therapy (ERT) on insulin-like growth factor binding protein (IGFBP)-2, IGFBP-3, collagen and proteoglycan levels in the articular cartilage of the knee joint in a well-characterized monkey model of naturally occurring osteoarthritis (OA). A secondary aim was to evaluate the effect of soy phytoestrogen treatment on these articular cartilage components. DESIGN: Monkeys were ovariectomized and given ERT, soy phytoestrogen treatment or no treatment (control) for 3 years. Ten animals were randomly selected from each of the three groups and the cartilage was dissected from the proximal tibia and distal femur of the knee. Levels of IGFBP-2, IGFBP-3, and total protein were measured in cartilage desorptions, and proteoglycan levels and collagen levels were measured in the cartilage tissue. Sections from the tibial plateau of the opposite knee were immunostained using antibodies directed against IGFBPs and evaluated subjectively. RESULTS: IGFBP-3 levels were significantly higher, and total protein levels were significantly lower in the cartilage desorption samples from the estrogen-treated animals compared to the control animals. There were no significant differences in IGFBP-2, collagen or proteoglycan levels between the estrogen-treated and control groups. Soy phytoestrogen treatment had no significant effect on the levels of any of the cartilage components that were measured. The staining patterns observed by immunohistochemistry suggested local production of IGFBP-2 and IGFBP-3 by articular cartilage chondrocytes. CONCLUSIONS: Long-term estrogen treatment results in increased IGFBP-3 levels in articular cartilage without a significant change in IGFBP-2, collagen or proteoglycan content, and IGFBP-3 appears to be synthesized by articular cartilage chondrocytes. Long-term soy phytoestrogen treatment did not have a statistically significant effect on the levels of IGFBP-2, IGFBP-3, collagen or proteoglycan.

The correlation of the complex dielectric constant and blood glucose at low frequency.

A new needle-type sample cell was designed and produced to investigate the correlation between blood glucose and electrical parameters using an impedance analyzer. The characteristics of the measurement cells were optimized to give high sensitivity. High sensitivity complex dielectric constant measurements were obtained by calibration with several known fluids. It was observed that the values of the real (epsilon') and the imaginary (epsilon") dielectric constant increase with decreasing glucose contents in the water/glucose system, and that the value of epsilon' in hamster tail changes according to the variation in blood glucose. It is likely that there is a correlation between blood glucose and the value of epsilon', the electrical parameter.

A biomechanical study of the finger pulley system during repair.

This paper addresses the mechanics of the finger/pulley system when subjected to various excisions and repairs. Several cadaver hands were used to study the finger/pulley's function, finger joint dynamics, and the relationship between tendon excursion and finger joint angles of rotation. By using a method of continuous and simultaneous data acquisition of the entire finger joint's motion, a more detailed analysis was achieved. Our experimental investigation is based on the use of four micro-potentiometers inserted at the finger's joints and a pulley system to simulate tendon excursion. Using this procedure, a detailed kinematic analysis of the entire finger was performed. This included analysis of the intact hand, various pulley excisions, and reconstruction. In addition to introducing a new method of acquisition, a mathematical model was developed for the inverse dynamic analysis of the finger pulley system. From this model, the torques required at the joints for the motion were computed. The results provided new insight into possible ways of characterizing kinematic changes resulting from pulley damage and repair.

One-visit apexification: technique for inducing root-end barrier formation in apical closures.

Numerous procedures and materials have been utilized to induce root-end barrier formation. Mineral trioxide aggregate (MTA) was introduced to dentistry as a root-end filling material. It has been advocated for filling root canals, repairing perforations, pulp capping, and root-end induction. Mineral trioxide aggregate reacts with tissue fluids to form a hard tissue apical barrier. As a result, MTA shows promise as a valuable material for use in one-visit apexification treatment, primarily for treating immature teeth with necrotic pulps.

Effect of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'- dicarboxylate (DDB) on chemical-induced liver injury.

The effects of orally administered dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene-dioxybiphenyl-2,2'-d icarboxylate (DDB) on the hepatotoxicity induced by carbon tetrachloride, acetaminophen or ethanol were investigated in rats and mice. Either single or repeated DDB pretreatment (50 or 200 mg/kg) did not alter the hepatotoxicity induced by carbon tetrachloride (0.2 or 1.0 ml/kg, i.p.) in female rats as indicated by increases in the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) in serum. The hepatotoxicity of acetaminophen (350 mg/kg, i.p.) was also unaffected in male mice pretreated with DDB (50 mg/kg/d) for a week. However, DDB administration (50 mg/kg/d for 7 d) decreased the hepatic fatty degeneration induced by repeated ethanol treatment (0.75 g/kg, i.p., x2 times a day for a week) in rats as shown by the accumulation of triglycerides and cholesterol in the liver. Malondialdehyde (MDA) formation in liver homogenates was inhibited by DDB treatment. The significance of the action of DDB on alcoholic fatty liver generation in clinical settings is discussed.

Application of multiple bioindicators to differentiate spatial and temporal variability from the effects of contaminant exposure on fish.

Bioindicators of fish health were measured from 1989 through 1994 in populations of redbreast sunfish (Lepomis auritus) at three sites within a stream receiving inputs of mixed contaminants from an industrial facility, and at two reference sites. Bioindicator responses differed for fish from contaminated and reference sites throughout the study period, but temporal trends at contaminated sites reflected improved water quality associated with pollution-control efforts. Temporal variability unrelated to contaminant exposure strongly influenced the response of bioindicators at both reference and contaminated sites, but spatial variability rarely influenced these responses. Temporal variability was less influential on slower responding indicators at higher levels of biological organization. The diverse response characteristics of indicators increased the ability to differentiate natural from anthropogenic sources of variability. Integrated bioindicator responses were compared among site-year groups by multivariate canonical analysis. The primary canonical variable, associated with differences in growth, exhibited trends consistent with the timing of pollution-control efforts. Two indicators of contaminant exposure (7-ethoxyresorufin O-deethylase activity and polychlorinated biphenyls in fish muscle) also exhibited trends consistent with the timing of pollution-control efforts, but the likelihood of possible mechanistic linkages cannot be assessed with available data.

Functional and morphological changes induced by tunicamycin in dividing and confluent endothelial cells.

Cultured bovine aortic endothelial cells treated with tunicamycin, an inhibitor of glycoprotein synthesis, developed a concentration-dependent inhibition of N-acetylglucosamine-1-phosphate transferase activity, and this inhibition was correlated with a substantial decrease in [3H]mannose incorporation by the cells. Endothelial cells were very sensitive to tunicamycin, and changes in their morphology occurred as a result of the inhibition of glycoprotein synthesis. The cells became elongated, the surface irregular, roughened, and granular, and there was an increase in the interstitial space between the cells. Electron dense material was accumulated within and dilated the rough endoplasmic reticulum, and the distribution of the glycoproteins laminin and fibronectin throughout the endothelial cell monolayer was modified. These morphological changes coincided with functional impairment with the permeability of endothelial cell monolayers to both 125I-albumin and [3H]inulin being increased by treatment with tunicamycin (10(-6) M) for 24 h. These results indicate that the synthesis of glycoproteins is crucial for cell-cell adhesion and the functional properties of the endothelial lining of blood vessels.