Modeling Bioinspired Fish Scale Designs via a Geometric and Numerical Approach.

Fish scales serve as a natural dermal armor with remarkable flexibility and puncture resistance. Through studying fish scales, researchers can replicate these properties and tune them by adjusting their design parameters to create biomimetic scales. Overlapping scales, as seen in elasmoid scales, can lead to complex interactions between each scale. These interactions are able to maintain the stiffness of the fish's structure with improved flexibility. Hence, it is important to understand these interactions in order to design biomimetic fish scales. Modeling the flexibility of fish scales, when subject to shear loading across a substrate, requires accounting for nonlinear relations. Current studies focus on characterizing these kinematic linear and nonlinear regions but fall short in modeling the kinematic phase shift. Here, we propose an approach that will predict when the linear-to-nonlinear transition will occur, allowing for more control of the overall behavior of the fish scale structure. Using a geometric analysis of the interacting scales, we can model the flexibility at the transition point where the scales start to engage in a nonlinear manner. The validity of these geometric predictions is investigated through finite element analysis. This investigation will allow for efficient optimization of scale-like designs and can be applied to various applications.

Lossless single-photon shaping via heralding.

Using spontaneous optical parametric downconversion, we experimentally demonstrate heralded generation of shaped single photons, whose modes are tailored indirectly by applying amplitude modulation on the pump field that drives the downconversion process. Our experiment opens a door to creating high-quality, mode-shaped single photons at a substantially higher efficiency than is possible with the existing method of direct single-photon shaping.

Effect of storage duration on the hardness and tensile bond strength of silicone- and acrylic resin-based resilient denture liners to a processed denture base acrylic resin.

STATEMENT OF PROBLEM: Two potential problems commonly identified with a denture base incorporating a resilient liner are a failure of the bond between the acrylic resin and resilient liner material and a loss of resiliency of the resilient liner material over time. PURPOSE: This investigation evaluated the effect of storage duration on the tensile bond strength and hardness of acrylic resin- and silicone-based resilient liners that were either heat- or autopolymerized onto denture base acrylic resin. MATERIAL AND METHODS: The denture liners investigated were a definitive acrylic resin-based heat-polymerized (Vertex Soft), interim acrylic resin-based autopolymerized (Coe-Soft), definitive silicone-based heat-polymerized (Molloplast-B), and definitive silicone-based autopolymerized (Mollosil Plus) resilient liner. The resilient liners were processed according to manufacturers' instructions. The resilient liner specimens for tensile bond strength testing (n=10) were 10 x 10 x 3 mm and were processed between 2 polymethyl methacrylate (PMMA) (Meliodent) blocks (40 x 10 x 10 mm). The resilient liner specimens for hardness testing (n=10) were 20 mm in diameter and 12 mm in height. Specimen shape and liner thickness were standardized. Specimens were stored for 1 day, 1 week, or 1, 3, or 6 months in water at 37 degrees C. Tensile bond strength was measured in a universal testing machine at a crosshead speed of 20 mm/min, and hardness was measured using a Shore A durometer. Two-way ANOVA and Tukey HSD tests were used to analyze the data (alpha=.05). RESULTS: The results indicated that there were significant differences both in the hardness and bond strength values of resilient liner materials. The definitive silicone-based heat-polymerized (Molloplast-B) resilient liner had significantly higher bond strength and lower hardness values than the others. Prolonged exposure to water produced significantly higher hardness values and lower bond strength values. CONCLUSIONS: Within the limitations of this in vitro study, specimens of resilient liners immersed in water demonstrated significantly (P<.001) lower bond strength values and higher hardness values over time.

Relation between proinflammatory to anti-inflammatory cytokine ratios and long-term prognosis in patients with non-ST elevation acute coronary syndrome.

OBJECTIVE: To investigate the relation between serum high sensitivity (hs) C reactive protein (CRP), proinflammatory cytokine concentrations, proinflammatory to anti-inflammatory cytokine ratios and long-term prognosis in patients with non-ST elevation acute coronary syndrome (NSTEACS). DESIGN: Prospective follow-up study for the first six months and then for the first year after admission to hospital. SETTING: Tertiary referral centre. PATIENTS: 80 patients (60 men, 20 women, mean age 60 (SD 10) years) with NSTEACS and moderate to high TIMI (Thrombolysis In Myocardial Infarction) risk scores. INTERVENTIONS: Blood samples from patients with NSTEACS were obtained at the time of admission. Serum concentrations of hs-CRP, (hs) pro-inflammatory (interleukin (IL) -1beta, IL-6, tumour necrosis factor alpha) and (hs) anti-inflammatory (IL-10) cytokines were analysed and proinflammatory to anti-inflammatory cytokine ratios were calculated by dividing proinflammatory cytokine concentrations by anti-inflammatory cytokine IL-10. MAIN OUTCOME MEASURE: The primary end point of the study was new coronary events (NCE) defined as the combination of cardiac death, non-fatal myocardial infarction and recurrent rest angina that required hospitalisation within 12 months of follow up. RESULTS: During the one-year follow-up period, 23 patients (29%) met the NCE criteria. Concentrations of hs-CRP, IL-1beta and IL-6 and ratios of IL-1beta:IL-10 and IL-6:IL-10 were significantly higher in patients with NCE than in patients without NCE. In the logistic regression analysis, IL-6:IL-10 ratio was the most important predictor for NCE (p = 0.006) with an odds ratio of 2.24 (95% CI 1.26 to 3.97). CONCLUSIONS: Cytokine concentrations and proinflammatory to anti-inflammatory cytokine ratios may be useful markers for predicting vascular risk in patients with NSTEACS.

Effect of storage duration on tensile bond strength of acrylic or silicone-based soft denture liners to a processed denture base polymer.

OBJECTIVE: To investigate the effect of storage duration on the tensile bond strength of acrylic and silicone-based denture base materials with liners either heat-cured or auto-cured. MATERIAL AND METHODS: The denture liners investigated were Vertex soft (acrylic-based, heat-cured), Coe soft (acrylic-based, auto-cured), Molloplast-B (silicone-based, heat-cured), and Mollosil plus (silicone-based, auto-cured). The soft liner specimens were 10 x 10 x 3 mm and were processed between two PMMA blocks. They were tested following immersion in water at 37 degrees C for 1 day, 1 week, and 1, 3, and 6 months. Tensile bond strength was measured using a universal testing machine (Testometric Micro 500) at a crosshead speed of 20 mm/min (n = 10 specimens per experimental group). Multiple ANOVA and Tukey HSD were used to analyse the data at a pre-set alpha of 0.05. RESULTS: The results indicate that the tensile bond strength of acrylic-based soft liners is greater than that of silicone-based materials. The bond strength of all lining materials decreases with storage duration; the decrease being greatest for the acrylic-based soft liners. The decrease in bond strength of the auto-cured materials is greater than that of the heat-cured products. CLINICAL SIGNIFICANCE: Comparison of the materials in this study indicates that the silicone-based, heat-cured soft liner is superior, based on the tensile bond strength property. Use of silicone-based, heat-cured soft liners may provide better clinical success over a long period. These laboratory results need to be verified by clinical testing.

Quantum imaging of nonlocal spatial correlations induced by orbital angular momentum.

Through scanned coincidence counting, we probe the quantum image produced by parametric down-conversion with a pump-beam carrying orbital angular momentum. Nonlocal spatial correlations are manifested through splitting of the coincidence spot into two.

Effect of the Valsalva manoeuver on diastolic filling indices in patients with essential hypertension.

In some hypertensive patients, echocardiographic examination does not reveal any pathologic finding in spite of a documented blood pressure elevation. In our study, we investigated the effect of preload reduction with Valsalva manoeuver on transmitral flow velocities in hypertensive patients with normal mitral flow pattern and compared the results with a healthy control group. Sixty-eight patients without evidence of coronary artery disease or heart failure (28 female, 40 male, age 50 +/- 7) were divided in two groups according to their E/A ratio as those with diastolic dysfunction (n = 36) and without diastolic dysfunction (DD(-): n = 32). DD(-) patients and the control group (n = 20) performed Valsalva manoeuver and their pulsed-Doppler mitral flow measurements were repeated at the strain phase. During Valsalva manoeuver, E wave velocity decreased in all subjects. In the controls, peak A velocity showed a similar decline and E/A ratio remained over 1.0. However, in 72% of DD(-) patients A velocity did not change or increased and their E/A ratio fell below 1.0. In 47% of the patients with an E/A ratio reversal after Valsalva manoeuver, myocardial perfusion scintigraphy revealed reversible defects whereas none of the patients whose E/A ratio remained over 1.0 had perfusion defects. It is concluded that: (1) in hypertensive patients with normal E/A ratio Valsalva manoeuver should be performed in order to unmask a probable false normal finding, (2) an important percent of hypertensive individuals have left ventricular relaxation abnormalities, and (3) diastolic dysfunction develops together with a decrease in coronary reserve.

Hepatomesenteric trunk.

An hepatomesenteric trunk, formed by the common hepatic and superior mesenteric arteries, was found in a 50-year-old male cadaver. The left gastric and splenic arteries arose as a common trunk, the gastrosplenic trunk, from the abdominal aorta; no typical celiac trunk was present. In addition, the hepatomesenteric trunk passed posterior to the portal vein. A knowledge of variations of the common hepatic artery may be important in pancreaticoduodenectomy, as well as during hepatic artery infusion chemotherapy.