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Early in the pandemic and prior to the development of the COVID-19 vaccine, prevention measures were promoted to help inhibit the spread of the virus. To optimize adherence to prevention practices, it's important to understand factors that may influence adherence. A study was conducted in the month of April, 2020, to explore the influence of perceptions of COVID-19 on prevention practices. The sample included members of a public social-media group focused on providing updates and information on COVID-19. A total of 719 individuals completed an online survey that assessed various aspects of COVID-19 which included experience, perceptions, and prevention practices. The perceptions of COVID-19 included perceived susceptibility of contracting the virus, and perceived potential severity if contracted COVID-19. To assess prevention practices, the survey included a 10-item prevention practices questionnaire that included items such as wearing a mask, and social distancing. Results revealed that perceived susceptibility of contracting COVID-19, and potential severity of COVID-19 were significant in predicting prevention practices. Further, results suggest that perceived potential severity predicts a greater proportion of the variance in prevention practices than susceptibility of contracting COVID-19. In addition, a moderation analysis revealed no interaction between perceived susceptibility and severity, which provides evidence that the variables do not influence one another. Theoretical and practical implications are discussed. [ABSTRACT FROM AUTHOR]

The effects of drift angle on model ship flow are investigated through towing tank tests for the Series 60 CB=0.6 cargo/container model ship. Resistance, side force, drift moment, sinkage, trim, and heel data are procured for a range of drift angles β and Froude numbers ( Fr) and the model free condition. Detailed free-surface and mean velocity and pressure flow maps are procured for high and low Fr=0.316 and 0.16 and β=5° and 10° (free surface) and β=10° (mean velocity and pressure) for the model fixed condition (i.e. fixed with zero sinkage, trim, and heel). Comparison of results at high and low Fr and previous data for β=0° enables identification of important free-surface and drift effects. Geometry, conditions, data, and uncertainty analysis are documented in sufficient detail so as to be useful as a benchmark for computational fluid dynamics (CFD) validation. The resistance increases linearly with β with same slope for all Fr, whereas the increases in the side force, drift moment, sinkage, trim, and heel with β are quadratic. The wave profile is only affected near the bow, i.e. the bow wave amplitude increases/decreases on the windward/leeward sides, whereas the wave elevations are affected throughout the entire wave field. However, the wave envelope angle on both sides is nearly the same as β=0°, i.e. the near-field wave pattern rotates with the hull and remains within a similar wave envelope as β=0°. The wave amplitudes are significantly increased/decreased on the windward/leeward sides. The wake region is also asymmetric with larger wedge angle on the leeward side. The boundary layer and wake are dominated by the hull vortex system consisting of fore body keel, bilge, and wave-breaking vortices and after body bilge and counter-rotating vortices. The occurrence of a wave-breaking vortex for breaking bow waves has not been previously documented in the literature. The trends for the maximum vorticity, circulation, minimum axial velocity, and trajectories are discussed for each vortex. [ABSTRACT FROM AUTHOR]

Unsteady resistance, heave force, pitch moment and free-surface elevations for DTMB 5512 at steady forward speed and in regular head waves are investigated with different measurement systems for a fairly wide range of test conditions in the IIHR towing tank. Test data are procured for validation of Reynolds-averaged Navier–Stokes computational fluid dynamics codes and for understanding the physics of unsteady ship hydrodynamics. The second part of the paper presents the measurement results and discussions. [ABSTRACT FROM AUTHOR]

A model-scale naval surface combatant, DTMB 5512, is studied experimentally in steady forward speed and regular head waves with the Iowa Institute of Hydraulic Research towing-tank facilities. Unsteady resistance, heave force, pitch moment and free-surface elevations are investigated with different measurement systems for a fairly wide range of test conditions. Test data is procured for validation of RANS computational fluid dynamics codes and for understanding the physics of unsteady ship hydrodynamics. In the first part of the two-part paper, details of data reductions, measurement systems and uncertainty assessment procedures are provided. [ABSTRACT FROM AUTHOR]

Objective: To compare noncontrast helical computed tomography (NCHCT) and intravenous urography (IVU) for diagnosis of urinary calculi in evaluation of renal colic. Materials and methods: A 4-month prospective paired study compared NCHCT and IVU in patients being evaluated for renal colic. Each patient was studied with NCHCT followed by an IVU. An IVU was regarded as positive if any of the following were identified: delayed filling, hydronephrosis, hydroureter, ureteral calculus, or extravasation of contrast. A NCHCT was regarded as positive if any of the following were identified: hydronephrosis, hydroureter, ureteral calculus, or perinephric or ureteral inflammatory change. The sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) were reported using the clinical outcome as the gold standard, by either observation of passage or retrieval of calculus. Bladder distention was noted on NCHCT relative to the level of the acetabulum. The charts were also reviewed retrospectively for the results of urinalysis. Results: One hundred sixty-eight patients had both examinations interpreted. Nineteen positive NCHCT and IVU studies were eliminated due to lack of observation or retrieval of calculus, leaving 149 studies for interpretation. NCHCT had Se 0.98, Sp 0.95, PPV 0.98, and NPV 0.95. IVU had Se 0.83, Sp 0.95, PPV 0.97, and NPV 0.67. In 13/168 (8 %) cases, and in 9/37 (24 %) negative cases, NCHCT offered an alternative diagnosis. Ureterovesical junction (UVJ) calculus was identified on 84 NCHCT scans, with near-even distribution between well, partially, and poorly distended bladder. No UVJ calculus was identified on IVU that was not present on NCHCT. Absence of hematuria was found in 26 % of patients with proven urolithiasis. Conclusion: NCHCT is superior to IVU for the evaluation of renal colic. NCHCT identifies significant pathology in 24 % of cases negative for ureteral obstruction/calculus. Bladder distention does not play an important role in detection of UVJ calculus. Hematuria is not universally present in patients with painful urolithiasis. [ABSTRACT FROM AUTHOR]

A towed PIV system designed by DANTEC Measurement Technology for the Iowa Institute of Hydraulic Research towing tank is commissioned by measuring the mean velocity and Reynolds stresses at the nominal-wake plane of a model-scale ship. The mean velocities are compared with previous 5-hole pitot probe data. Uncertainty assessment following standard procedures is used to quantify the comparisons and reach conclusions regarding the quality of the data. The PIV results are analyzed with regard to axial velocity defects, axial vorticity, and level, pattern and anisotropy of turbulence. Quantitative comparisons with 5-hole pitot data shows that PIV uncertainties are about 1% lower than those for 5-hole pitot. However, data differences are larger than RSS of PIV and 5-hole pitot uncertainties for the axial and vertical velocity components, indicating unaccounted for bias and precision limits. The bias error of the pitot probe in a shear flow is discussed, and a method for reducing the bias error is suggested. The data is being used for verification and validation of RANS simulation of DTMB Model 5512. [ABSTRACT FROM AUTHOR]

Influences of evaluation bias of the correlation-based interrogation algorithm on particle image velocimetry (PIV) measurement of turbulent flow are investigated. Experimental tests in the Iowa Institute of Hydraulic Research towing tank with a towed PIV system and a surface-piercing flat plate and simulations demonstrate that the experimentally determined mean velocity and Reynolds stress components are affected by the evaluation bias and the gradient of the evaluation bias, respectively. The evaluation bias and gradient of the evaluation bias can both be minimized effectively by using Gaussian digital masks on the interrogation window, so that the measurement uncertainty can be reduced. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the results obtained with percutaneous therapeutic procedures in patients with Budd-Chiari syndrome (BCHS).Methods: Between August 1991 and April 1993, seven patients with BCHS were treated in our hospital. Three presented with a congenital web; in another three cases the hepatic veins and/or the inferior vena cava (IVC) were compromised after major hepatic surgery; one patient presented with a severe stenosis of the intrahepatic IVC due to hepatomegaly.Results: One of the patients with congenital web has required several new dilatations due to restenosis; one patient required a transjugular intrahepatic portosystemic shunt procedure while awaiting a liver transplantation. The two postsurgical patients with stenosed hepatic veins did not require any new procedure after the placement of metallic endoprostheses. However, the patient with liver transplantation presented IVC restenosis after balloon angioplasty that required the deployment of metallic endoprostheses. In the patient with hepatomegaly a self-expandable prosthesis was placed in the intrahepatic portion of the IVC before (4 months) a liver transplantation.Conclusion: Interventional therapeutic techniques offer a wide variety of possibilities for the treatment of patients with BCHS. For IVC stenoses, the results obtained with balloon angioplasty are at least as good as those obtained with surgery. [ABSTRACT FROM AUTHOR]

Percutaneous embolization of large portosystemic collaterals was performed in three patients following placement of a transjugular intrahepatic portosystemic shunt in order to improve hepatopetal portal flow. Improved hepatic portal perfusion was achieved in these cases, thereby theoretically reducing the risk of chronic hepatic encephalopathy. [ABSTRACT FROM AUTHOR]

A case of an infected pseudocyst in the head of the pancreas is presented. Due to its small size and fistulization to the duodenum, a drainage catheter was placed through the fistulous tract from a distant transgastric approach. The fistula was balloon dilated to improve its emptying. Sixteen months later the patient remains asymptomatic with no recurrence of the pseudocyst. [ABSTRACT FROM AUTHOR]

Percutaneous transhepatic treatment of portal vein thrombosis after liver transplantation in a patient with a preexisting high volume spontaneous splenorenal shunt is presented. Local thrombolysis with urokinase and balloon angioplasty of the main portal vein stenosis were performed followed by shunt embolization to restore hepatopetal portal blood flow. [ABSTRACT FROM AUTHOR]

Posttransplant lymphoproliferative disorders are infrequent tumors related to chronic immunosuppressive therapy. We present a liver transplant recipient who developed such a tumor in the porta hepatis that provoked obstruction of the entire portal triad. Treatment consisted of systemic chemotherapy, percutaneous dilatation, and placement of Wallstent endoprostheses across both biliary and portal vein stenoses. The patient died 3 weeks later of pneumonia and sepsis. At necropsy, the tumor was completely necrosed and the prostheses in both the common bile duct and the portal vein were patent. [ABSTRACT FROM AUTHOR]

Portal vein (PV) thrombosis increases the risk of variceal bleeding in cirrhotic patients with portal hypertension. Its presence also complicates PV access during transjugular porto-caval shunt (TIPS) placement. We overcame this obstacle by using ultrasound (US) guidance for PV entry. Clot disruption by balloon catheters was then performed before placing the vascular endoprostheses for portal-venous shunting. We treated 3 cirrhotic patients in such fashion with good clinical results. Portal thrombi progressively disappeared after shunting due to both balloon disruption and the rise in portal blood flow velocity. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to assess the efficacy of transjugular intrahepatic portosystemic shunts (TIPS) in 45 patients with cirrhosis during a mean follow-up of 7 months.Methods: Forty-five consecutive patients treated by TIPS and who had been followed for at least 6 months after TIPS or until death, were included. Mean follow-up was 7.2 +/- 5.0 months. Shunt patency was assessed at 1 week and 1 month, then every 3 months after the procedure by Doppler US and angiography whenever needed.Results: Thirty-six patients had been stented for refractory bleeding from ruptured esophagogastric varices. Of these, 8 patients (22%) rebled, 7 of whom were treated by a second shunt. Nine patients were treated for refractory ascites. Three patients had recurrent ascites due to shunt obstruction. All were treated by a second shunt which occluded in 2 patients. As a whole, 14 (31.1%) patients developed shunt obstruction within a mean of 120 +/- 136 days, 4 of whom remained asymptomatic. Other complications were septicemia by Staphylococcus aureus in 1 patient, transient encephalopathy in 9 patients, and disseminated intravascular coagulation in 1 patient.Conclusions: TIPS appears to be a relatively safe and effective technique in treating complications of portal hypertension in patients with cirrhosis. Shunt obstruction in 31% of our patients probably represents the most important limitation of this technique. [ABSTRACT FROM AUTHOR]

High quality InAsSbP quaternary layers, which are lattice matched to InAs, have been grown successfully on InAs substrates by liquid phase epitaxy. Both Graded and constant composition InAsSbP layers have been grown. In addition, the graded InAsSbP layer has been used as a buffer layer for the growth of InAsSb on an InAs substrate. [ABSTRACT FROM AUTHOR]

The Reynolds-averaged flow for a solid/free-surface juncture boundary layer and wake is documented. The three mean-velocity components and five of the Reynolds stresses are measured for a surface-piercing flat plate in a towing tank using a laser-Doppler velocimeter system for both boundary-layer and wake planes in regions close to the free surface. The experimental method is described, including the foil-plate model, laser-Doppler velocimeter system, conditions, and uncertainty analysis. The underlying flow data is in excellent agreement with benchmark data. Inner (near the plate and wake centerplane and below the free surface) and outer (near the free surface) regions of high streamwise vorticity of opposite sign are observed, which transport, respectively, high mean velocity and low turbulence from the outer to the inner and low mean velocity and high turbulence from the inner to the outer portions of the boundary layer and wake. For the wake, the inner region of vorticity is relatively weak. The physical mechanism for the streamwise vorticity is analyzed with regard to the Reynolds-averaged streamwise vorticity equation. The anisotropy of the crossplane normal Reynolds stresses closely correlates with the vorticity and, additionally, indicates similarity, i.e., its nature is such that it only depends on the proximity to the plate and free surface boundaries or wake centerplane symmetry plane. Free-surface effects on the Reynolds stresses are analyzed with regard to the behavior close to the free surface of the turbulent kinetic energy and the normal components of the anisotropy tensor and the anisotropy invariants. Close to the free surface, the turbulent kinetic energy is nearly constant and increases for the inner and outer portions, respectively, of the boundary layer and wake and the normal components of the anisotropy tensor and the anisotropy invariants roughly correspond to the limiting values for two-component turbulence. The similarities and differences between the present results and analysis with those from related studies are discussed. The data and analysis should have practical application with regard to the development of turbulence models for computational fluid dynamics methods for the Reynolds-averaged Navier–Stokes equations. [ABSTRACT FROM AUTHOR]

We present a case report of a patient suffering from portal and superior mesenteric vein thrombosis secondary to splenectomy. No surgical procedure could be performed due to the extension of thrombus. Local fibrinolysis treatment with urokinase through a percutaneous transhepatic approach was decided upon, and this procedure had a successful patient outcome. [ABSTRACT FROM AUTHOR]

This paper presents the first description of a ruptured aneurysm of an aberrant right subclavian artery. CT clearly demonstrated the vascular malformation as well as the existence of a bilateral hemothorax. [ABSTRACT FROM AUTHOR]

We report a case of primary amyloidosis affecting the kidney and presenting as a renal infarction on computed tomography and ultrasound examination. To our knowledge, it is the first case in the radio-logical literature with these imaging characteristics. [ABSTRACT FROM AUTHOR]

A case of aortoesophageal fistula (AEF) is reported in a patient with esophageal bleeding resulting from ingestion of a foreign body. CT showed a saccular aneurysm in close proximity to the esophageal lumen at the level of the bleeding site. AEF has not previously been described on CT. [ABSTRACT FROM AUTHOR]

This paper offers an overview of existing international monitoring systems with relevance for environmental health surveillance. Representative monitoring systems are described that: address areas of chronic and acute exposure, and diseases and behavioural effects resulting from human-environment interactions; have an ecosystem focus with perhaps a secondary motivation of ascertaining human health impacts that may result from ecosystem conditions; and that incorporate socio-demographic and economic data that may reflect population health determinants. General conclusions on the state of environmental surveillance systems and suites of indicators reviewed are provided in relation to their utility for the development of a generic environmental health surveillance system. This review indicates, among other things, that no obvious short list of core indicators exists which spans "environmental health" to provide a sufficient set applicable in a global context. Through a summary of challenges and limitations in existing systems and indicator sets, recommendations are provided for the discussion of indicator selection and organization, and of developing general and widely applicable environmental health monitoring and surveillance systems.