High contrast air-coupled acoustic imaging with zero group velocity Lamb modes

The well known zero in the group velocity of the first-order symmetric (S1) plate wave mode has been exploited in air-coupled ultrasonic imaging to obtain significantly higher sensitivity than can be achieved in conventional air-coupled scanning. At the zero group velocity point at the frequency minimum of the S1mode, a broad range of wavenumbers couple into the first-order symmetric mode at nearly a constant frequency, greatly enhancing transmission at that frequency. Coupled energy remains localized near the coupling point because the group velocity is zero. We excite the mode with a broadband, focussing, air-coupled transducer at the frequency of the zero group velocity point in the S1 mode. By exploiting the efficient coupling at the zero group velocity frequency, we have easily imaged a single layer of Scotch tape attached to a 6.4-mm thick Plexiglas plate and 3.2-mm Teflon inserts in a composite laminate

Towards Intelligent Databases

This article is a presentation of the objectives and techniques of deductive databases. The deductive approach to databases aims at extending with intensional definitions other database paradigms that describe applications extensionaUy. We first show how constructive specifications can be expressed with deduction rules, and how normative conditions can be defined using integrity constraints. We outline the principles of bottom-up and top-down query answering procedures and present the techniques used for integrity checking. We then argue that it is often desirable to manage with a database system not only database applications, but also specifications of system components. We present such meta-level specifications and discuss their advantages over conventional approaches

Air-coupled, focused ultrasonic dispersion spectrum reconstruction in plates

This paper presents and demonstrates a noncontact method for measuring the Lamb wave dispersion spectrum of a plate. Noncontact air-coupled source and receive transducers are used with line-focus mirrors and 50–700 kHz broadband apparatus for simultaneous measurement over a broad spectrum of refractive angles and multiple guided modes. Broadband, wide-angle wave forms are measured as a function of position. The Fourier transform of these wave forms from the t – x domain to the v – k domain gives an approximate spectrum of the dispersion relation. We measure the dispersion spectra of Lucite™, aluminum, balsa wood, and a carbon fiber epoxy laminate, and show that the measured spectra agree well with the dispersion relation calculated from Lamb wave theory

Impeded Growth of Magnetic Flux Bubbles in the Intermediate State Pattern of Type I Superconductors

Normal state bubble patterns in Type I superconducting Indium and Lead slabs are studied by the high resolution magneto-optical imaging technique. The size of bubbles is found to be almost independent of the long-range interaction between the normal state domains. Under bubble diameter and slab thickness proper scaling, the results gather onto a single master curve. On this basis, in the framework of the "current-loop" model [R.E. Goldstein, D.P. Jackson and A.T. Dorsey, Phys. Rev. Lett. 76, 3818 (1996)], we calculate the equilibrium diameter of an isolated bubble resulting from the competition between the Biot-and-Savart interaction of the Meissner current encircling the bubble and the superconductor-normal interface energy. A good quantitative agreement with the master curve is found over two decades of the magnetic Bond number. The isolation of each bubble in the superconducting matrix and the existence of a positive interface energy are shown to preclude any continuous size variation of the bubbles after their formation, contrary to the prediction of mean-field models.Comment: \'{e}quipe Nanostructures Quantique

Adult-Acquired Flatfoot Deformity and Age-Related Differences in Foot and Ankle Kinematics During the Single-Limb Heel-Rise Test

STUDY DESIGN: Cross-sectional laboratory study. OBJECTIVE: To compare single-limb heel-rise performance and foot-ankle kinematics between persons with stage 2 adult-acquired flatfoot deformity (AAFD) and healthy controls. BACKGROUND: The inability to perform a single-limb heel rise is considered a positive functional diagnostic test for AAFD. However, which foot motions contribute to poor performance of this task are not known. METHODS: Fifty individuals participated in this study, 20 with stage 2 AAFD (mean +/- SD age, 57.6 +/- 11.3 years), and 15 older participants (age, 56.8 +/- 5.3 years) and 15 younger participants (age, 22.2 +/- 2.4 years) without AAFD as control groups. Forefoot (sagittal plane) and rearfoot (sagittal and frontal planes) kinematics were collected using a 3-D motion analysis system. Heel-rise performance (heel height) and kinematics (joint angles, excursions) were evaluated. One-way and 2-way analyses of variance were used to examine differences in heel-rise performance and kinematics between groups. RESULTS: Individuals with AAFD and older controls demonstrated lower heel-rise height than those in the younger control group (P\u3c.001). Persons with AAFD demonstrated higher degrees of first metatarsal dorsiflexion (P\u3c.001), lower ankle plantar flexion (P\u3c.001), and higher subtalar eversion (P = .027) than those in the older control group. Persons with AAFD demonstrated lower ankle excursion (P\u3c.001) and first metatarsal excursion (P\u3c.001) than those in the older control group, but no difference in subtalar excursion (P = .771). CONCLUSION: Persons with stage 2 AAFD did not achieve sufficient heel height during a single-leg heel rise. Both forefoot and rearfoot kinematics in the sagittal plane, as opposed to the frontal plane, contributed to the lower heel height in participants with stage 2 AAFD. Older controls demonstrated lower heel-rise height than younger controls, indicating that clinical expectations of heel-rise performance may need to be adjusted for age

Functional impairment of human resident cardiac stem cells by the cardiotoxic antineoplastic agent trastuzumab

Trastuzumab (TZM), a monoclonal antibody against the ERBB2 protein, increases survival in ERBB2-positive breast cancer patients. Its clinical use, however, is limited by cardiotoxicity. We sought to evaluate whether TZM cardiotoxicity involves inhibition of human adult cardiac-derived stem cells, in addition to previously reported direct adverse effects on cardiomyocytes. To test this idea, we exposed human cardiosphere-derived cells (hCDCs), a natural mixture of cardiac stem cells and supporting cells that has been shown to exert potent regenerative effects, to TZM and tested the effects in vitro and in vivo. We found that ERBB2 mRNA and protein are expressed in hCDCs at levels comparable to those in human myocardium. Although clinically relevant concentrations of TZM had no effect on proliferation, apoptosis, or size of the c-kit-positive hCDC subpopulation, in vitro assays demonstrated diminished potential for cardiogenic differentiation and impaired ability to form microvascular networks in TZM-treated cells. The functional benefit of hCDCs injected into the border zone of acutely infarcted mouse hearts was abrogated by TZM: infarcted animals treated with TZM + hCDCs had a lower ejection fraction, thinner infarct scar, and reduced capillary density in the infarct border zone compared with animals that received hCDCs alone (n = 12 per group). Collectively, these results indicate that TZM inhibits the cardiomyogenic and angiogenic capacities of hCDCs in vitro and abrogates the morphological and functional benefits of hCDC transplantation in vivo. Thus, TZM impairs the function of human resident cardiac stem cells, potentially contributing to TZM cardiotoxicity

MOSAIC: A Scalable reconfigurable 2D array system for NDT

This paper documents the development of a scalable 2D array system, or Mosaic that can be targeted at a wide range of NDT applications by way of a reconfigurable tile that can be tessellated to form arrays of any size and shape. Close coupling permits utilization of excitation voltages as low as +/-3.3V with insertion loss of 48dB on reflection from an aluminum back wall at 73mm achieved using 2D arrays without decoding

Locating air leaks in manned spacecraft using structure-borne noise

All manned spacecraft are vulnerable to leaks generated by micrometeorite or debris impacts. Methods for locating such leaks using leak-generated, structure-borne ultrasonic noise are discussed and demonstrated. Cross-correlations of ultrasonic noise waveforms from a leak into vacuum are used to find the location of the leak. Four methods for sensing and processing leak noise have been developed and tested and each of these can be used to reveal the leak location. The methods, based on phased-array, distributed sensor, and dual sensor approaches, utilize the propagation patterns of guided ultrasonic Lamb waves in the spacecraft skin structure to find the source or direction of the leak noise. It is shown that each method can be used to successfully locate the leak to within a few millimeters on a 0.6-m2 aluminum plate. The relative merits of the four methods are discussed

Use of biological drugs in patients with psoriasis and psoriatic arthritis in italy: Results from the PSONG survey

This Italian multicenter retrospective study compared the drug survival and efficacy of differentanti-TNF agents in psoriasis (PsO) and psoriatic arthritis (PsA) patients. A database of PsO/PsApatients treated with adalimumab, etanercept, and infliximab from May 2013 to May 2014 wasanalyzed. PASI 75, 90, and 100 was calculated at each time point to evaluate efficacy. Drug sur-vival rate and probability of maintaining PASI response were evaluated. The impact of dependentvariables on probability of PASI 75 loss was evaluated by logistic regression. 1,235 patients wereincluded, 577 with PsO and 658 with PsA. Highest survival rates were observed with adalimumabfollowed by etanercept and infliximab in PsO and PsA patients. The probability of maintainingPASI response was significantly higher for adalimumab followed by infliximab. For PsO patients,the odds of losing PASI 75 was higher in etanercept-treated patients (OR: 8.1; 95% CI: 4.2–15.6,p<.001) or infliximab (OR: 6.6; 95% CI: 2.6–16.3,p<.001) vs. adalimumab. Likewise, for PsApatients the odds of losing PASI 75 was higher in etanercept-treated patients (OR: 2.3; 95% CI:1.4–3.8,p5.01) or infliximab (OR: 2.2; 95% CI: 1.1–4.1,p5.018) vs. adalimumab. Adalimumabcould be the best therapeutic option over other anti-TNF agents for the treatment of PsO and PsApatients

An International Survey on Taking Up a Career in Cardiovascular Research: Opportunities and Biases toward Would-Be Physician-Scientists

Background Cardiovascular research is the main shaper of clinical evidence underpinning decision making, with its cyclic progression of junior researchers to mature faculty members. Despite efforts at improving cardiovascular research training, several unmet needs persist. We aimed to appraise current perceptions on cardiovascular research training with an international survey. Methods and Results We administered a 20-closed-question survey to mentors and mentees belonging to different international institutions. A total of 247 (12%) surveys were available (out of 2,000 invitations). Overall, mentees and mentors were reasonably satisfied with the educational and research resources. Significant differences were found analyzing results according to gender, geographic area, training and full-time researcher status. Specifically, women proved significantly less satisfied than men, disclosed access to fewer resources and less support from mentors (all P Conclusions Several potential biases appear to be present in the way training in cardiovascular research is provided worldwide, including one against women. If confirmed, these data require proactive measures to decrease discriminations and improve the cardiovascular research training quality