NOX Inhibitors - A Promising Avenue for Ischemic Stroke.

NADPH-oxidase (NOX) mediated superoxide originally found on leukocytes, but now recognized in several types of cells in the brain. It has been shown to play an important role in the progression of stroke and related cerebrovascular disease. NOX is a multisubunit complex consisting of 2 membrane-associated and 4 cytosolic subunits. NOX activation occurs when cytosolic subunits translocate to the membrane, leading to transport electrons to oxygen, thus producing superoxide. Superoxide produced by NOX is thought to function in long-term potentiation and intercellular signaling, but excessive production is damaging and has been implicated to play an important role in the progression of ischemic brain. Thus, inhibition of NOX activity may prove to be a promising treatment for ischemic brain as well as an adjunctive agent to prevent its secondary complications. There is mounting evidence that NOX inhibition in the ischemic brain is neuroprotective, and targeting NOX in circulating immune cells will also improve outcome. This review will focus on therapeutic effects of NOX assembly inhibitors in brain ischemia and stroke. However, the lack of specificity and toxicities of existing inhibitors are clear hurdles that will need to be overcome before this class of compounds could be translated clinically

Conversion from a Bio-inert Glass to a Glass with Bio-active Layer by Heat-treatment in an Oxidation Atmosphere

AbstractThe surface of iron-bearing bio-inert glasses was modified by heat-treatment in an oxidizing atmosphere near the glass transition temperature. The modified surfaces after 7 days immersion in simulated body fluid (SBF) solution were analyzed by means of micro-Raman spectroscopy, SEM, and EDS. All investigated glasses except for the glass with NC = 2.6 were able to form hyroxycarbonate apatite (HCA) on their surfaces. The thickness of an HCA surface layer increased with decreased oxygen partial pressure. The cross-sectional micrographs were nearly similar to the 45S5 Bioglass®

Waveguide Quantum Electrodynamics in Superconducting Circuits

Achieving an efficient interface of light and matter has been a principal goal in the field of quantum optics. A burgeoning paradigm in the study of light-matter interface is waveguide quantum electrodynamics (QED), where quantum emitters are coupled to a common one-dimensional waveguide channel. In this scenario, cooperative effects among quantum emitters emerge as a result of real and virtual exchange of photons, giving rise to new ways of controlling matter. Superconducting quantum circuits offer an exciting platform to study quantum optics in the microwave domain with artificial quantum emitters interfaced to engineered photonic structures on chip. Beyond revisiting the experiments performed in atom-based platforms, superconducting circuits enable exploration of novel regimes in quantum optics that are otherwise prohibitively challenging to achieve. Moreover, the unprecedented level of control over individual quantum degrees of freedom and good scalability of the system provided by state-of-the-art circuit QED toolbox set a promising direction towards the study of quantum many-body phenomena. In this thesis, I discuss waveguide QED experiments performed in superconducting quantum circuits where transmon qubits are coupled to engineered microwave waveguides. Employing the high flexibility and controllability of superconducting quantum circuits, we realize and explore various schemes for generating waveguide-mediated interactions between superconducting qubits. We also demonstrate an intermediate-scale quantum processor based on a dispersive waveguide QED system involving ten superconducting qubits, exploring quantum many-body dynamics in a highly controllable fashion. The work described in the thesis marks an important step towards the construction of scalable architectures for quantum simulation of many-body models and realization of efficient coupling schemes for quantum computation.</p

Mandatory Audit Firm Rotation and Audit Quality

Recently, regulators and policy makers who witnessed the global financial crisis during 2007–2009 began considering a variety of ways to enhance auditor independence and financial reporting quality, ultimately aiming at investor protection. Since the enactment of the Sarbanes–Oxley Act of 2002 (SOX), the Mandatory Audit Firm Rotation (MAFR) requirement has once again received significant attention from regulators and policy makers around the world, including the European Union (EU) and the U.S. Public Companies Accounting Oversight Board (PCAOB). In this paper, we investigate whether MAFR enhances audit quality in Korea. We find that under MAFR, newly rotated auditors are more likely to issue first-time going-concern audit opinions to financially distressed firms during their initial (first-year) financial statement audit compared with under the Voluntary Audit Firm Change (VAFC). Moreover, firms audited by mandatorily rotated new auditors have less discretionary accruals and higher accrual quality than those audited by voluntarily switched new auditors during the initial audit engagement. These results of earnings quality are more pronounced for firms that received a first-time going-concern audit opinion during the initial financial statement audit under MAFR. Taken together, the findings suggest that MAFR produces better audit quality than the VAFC. Further, our study provides implications for regulators and policy makers of countries considering the adoption of MAFR

Real-time delay-multiply-and-sum beamforming with coherence factor for in vivo clinical photoacoustic imaging of humans

In the clinical photoacoustic (PA) imaging, ultrasound (US) array transducers are typically used to provide B-mode images in real-time. To form a B-mode image, delay-and-sum (DAS) beamforming algorithm is the most commonly used algorithm because of its ease of implementation. However, this algorithm suffers from low image resolution and low contrast drawbacks. To address this issue, delay-multiply-and-sum (DMAS) beamforming algorithm has been developed to provide enhanced image quality with higher contrast, and narrower main lobe compared but has limitations on the imaging speed for clinical applications. In this paper, we present an enhanced real-time DMAS algorithm with modified coherence factor (CF) for clinical PA imaging of humans in vivo. Our algorithm improves the lateral resolution and signal-to-noise ratio (SNR) of original DMAS beam-former by suppressing the background noise and side lobes using the coherence of received signals. We optimized the computations of the proposed DMAS with CF (DMAS-CF) to achieve real-time frame rate imaging on a graphics processing unit (GPU). To evaluate the proposed algorithm, we implemented DAS and DMAS with/without CF on a clinical US/PA imaging system and quantitatively assessed their processing speed and image quality. The processing time to reconstruct one B-mode image using DAS, DAS with CF (DAS-CF), DMAS, and DMAS-CF algorithms was 7.5, 7.6, 11.1, and 11.3 ms, respectively, all achieving the real-time imaging frame rate. In terms of the image quality, the proposed DMAS-CF algorithm improved the lateral resolution and SNR by 55.4% and 93.6 dB, respectively, compared to the DAS algorithm in the phantom imaging experiments. We believe the proposed DMAS-CF algorithm and its real-time implementation contributes significantly to the improvement of imaging quality of clinical US/PA imaging system.11Ysciescopu

Clinical disease characteristics according to karyotype in Turner syndrome

Purpose : Turner syndrome (TS) is a disorder in which various anomalies can be accompanied, especially cardiovascular, renal, thyroid and auditory problems. The aim of this study is to identify the incidence of these disorders in patients with TS according to karyotype. Methods : We reviewed medical records of 90 patients with TS diagnosed by chromosomal analysis in 4 hospitals from Jan 1998 to Dec 2007. We evaluated these cases by prepared protocol of 4 medical problems. Results : The distribution of karyotype was 45,X (47.8&#37;), mosaic pattern (34.4&#37;) and structural aberration group (17.8 &#37;). Renal anomalies, cardiovascular anomalies, thyroid disorders and auditory problems are accompanied in 4.4&#37;, 10.0 &#37;, 11.1&#37; and 5.6&#37;, respectively. 45,X group had renal anomalies (7.0&#37;), cardiovascular anomalies (18.6&#37;), thyroid disorders (9.3&#37;) and auditory problems (11.6&#37;). Mosaic group had renal anomalies (3.2&#37;), thyroid disorders (12.9&#37;), no cardiovascular anomalies and auditory problems. Structural aberration group had cardiovascular anomalies (6.3&#37;), thyroid disorders (12.5&#37;) and no other 2 problems. Patients with 45,X group had a significant higher incidence of cardiovascular anomalies (P&#61;0.025). Conclusion : Our results indicate that there are differences clinically according to karyotype of TS, especially in incidence of cardiovascular anomalies