On computing the spectral radius of the Hankel plus Toeplitzoperator

The square root of the spectral radius of the Hankel plus Toeplitz operator has been shown to be the achievable performance of the mixed-sensitivity H^∞ design. The computation of the spectral radius is the bottleneck in the synthesis of the H ^∞ controller. In this paper, the spectral properties of the Hankel plus Toeplitz operator are investigated. A finite procedure for computing the spectral radius of the Hankel plus Toeplitz operator is proposed     

Curcumin provides potential protection against the activation of hypoxia and prolyl 4-hydroxylase inhibitors on prostate-specific antigen expression in human prostate carcinoma cells

Scope: Prostate‐specific antigen (PSA) is a well‐known marker for diagnosing and monitoring prostate cancer. Curcumin, a yellow curry pigment, has been reported to enhance androgen receptor (AR) degradation. We examined the effects of curcumin on increasing PSA expression by hypoxia and prolyl hydroxylase inhibitors, L ‐mimosine and dimethyloxalylglycine (DMOG), in human prostate carcinoma LNCaP cells. Methods and results: The ³H‐thymidine incorporation assay revealed that either L ‐mimosine or DMOG treatments attenuated cell proliferation. Immunoblot and enzyme‐linked immunosorbent assays (ELISA) indicated that both L ‐mimosine and DMOG have an effect similar to hypoxia, which stabilized hypoxia‐inducible factor‐1α (HIF‐1α) and induced PSA gene expression. The results of the immunoblot and transient gene expression assays indicated that induction of the PSA expression by hypoxia is both HIF‐1α‐ and AR‐dependent. Immunoblot assays revealed that a curcumin treatment (10 μM) decreased the protein abundance of AR but did not significantly affect the protein levels of HIF‐1α and vascular endothelial growth factor, which were induced by hypoxia. ELISA and transient gene expression assays indicated that curcumin blocked the activation of L ‐mimosine or DMOG treatment on PSA expression. Conclusions: These results indicate that curcumin blocked the enhanced effect of PSA expression by L ‐mimosine and DMOG that induce hypoxia condition.     

Registration techniques for using imperfect and partially calibrated devices in planar multi-projector displays

Multi-projector displays today are automatically registered, both geometrically and photometrically, using cameras. Existing registration techniques assume pre-calibrated projectors and cameras that are devoid of imperfections such as lens distortion. In practice, however, these devices are usually imperfect and uncalibrated. Registration of each of these devices is often more challenging than the multi-projector display registration itself. To make tiled projection-based displays accessible to a layman user we should allow the use of uncalibrated inexpensive devices that are prone to imperfections. In this paper, we make two important advances in this direction. First, we present a new geometric registration technique that can achieve geometric alignment {\em in the presence of severe projector lens distortion} using a relatively inexpensive low-resolution camera. This is achieved via a closed-form model that relates the projectors to cameras, in planar multi-projector displays, using rational Bezier patches. This enables us to geometrically calibrate a 3000 x 2500 resolution planar multi-projector display made of 3 x 3 array of nine severely distorted projectors using a low resolution (640 x 480) VGA camera. Second, we present a photometric self-calibration technique for a projector-camera pair. This allows us to photometrically calibrate the same display made of nine projectors using a photometrically uncalibrated camera. To the best of our knowledge, this is the first work that allows geometrically imperfect projectors and photometrically uncalibrated cameras in calibrating multi-projector displays.     

Inhibitory effects of sweet potato leaves on nitric oxide production and protein nitration

The inhibitory effects of a water extract of sweet potato leaves (WSPL) on nitric oxide (NO) production and protein tyrosine residue nitration were investigated. The results showed that WSPL inhibited NO production in a concentration-dependent manner. In the range of 0–1.0 mg/ml, the inhibitory effect on NO generation in macrophages increased with increasing concentration of WSPL. Meanwhile, the protein tyrosine residue nitration in mouse heart homogenates was inhibited by 1 mg/ml WSPL. In addition, WSPL, in the range of 0–0.4 mg/ml, also exhibited radical scavenging, reducing and chelating activities and protected liposomes against oxidative damage. A high performance liquid chromatography analysis revealed that phenolic acids and flavonols such as chlorogenic acid, caffeic acid, and quercetin were present in the WSPL, which could contribute to the protective effect against oxidative damage. Thus, WSPL might be useful in preventing protein nitration and oxidative stress.     

Synthesis of graphene on silicon carbide substrates at low temperature

A method for the synthesis of millimeter-scaled graphene films on silicon carbide substrates at low temperatures (750 °C) is presented herein. Ni thin films were coated on a silicon carbide substrate and used to extract the substrate’s carbon atoms under rapid heating. During the cooling stage, the carbon atoms precipitated on the free surface of the Ni and formed single-layer or few-layer graphene. The result shows that the number of graphene layers might be further controlled by appropriate process conditions. In contrast to the epitaxial graphene synthesis on single crystal silicon carbide, the graphene prepared here are continuous over the entire Ni-coated area, and can be stripped from the substrate much more easily for further characterization. The large-scaled, low temperature and transferable features of our method suggest the potential for future graphene-based applications.     

Image noise reduction using Wiener filtering with pseudo-inverse

We present a preliminary design and experimental results of a Gaussian noise reduction method for ultrasound images. Our method utilizes a Wiener filtering algorithm with pseudo-inverse technique. The method is capable of solving the Gaussian noise problem in ultrasound image by setup a constant dB of noise function. The key idea of the Wiener filtering algorithm is to process the given ultrasound signal by making the filtering less sensitive to slight changes in input conditions. In this paper, we investigate the possibility of employing this approach for pre-processing ultrasound image application. The application of the proposed method for reducing Gaussian noise is demonstrated by four examples. Meanwhile, we also made the comparisons with median filter, mean filter and adaptive filter; the results reveal that the proposed method has the best noise filtering capability than other three methods. The results also show that the proposed method produces recovery images with quiet high peak-signal-to-noise ratio.     

MRI brain lesion image detection based on color-converted K-means clustering segmentation

We present a preliminary design and experimental results of tumor objects tracking method for magnetic resonance imaging (MRI) brain images (some stock images) that utilizes color-converted segmentation algorithm with K-means clustering technique. The method is capable of solving unable exactly contoured lesion objects problem in MRI image by adding the color-based segmentation operation. The key idea of color-converted segmentation algorithm with K-means is to solve the given MRI image by converting the input gray-level image into a color space image and operating the image labeled by cluster index. In this paper we investigate the possibility of employing this approach for image-based-MRI application. The application of the proposed method for tracking tumor is demonstrated to help pathologists distinguish exactly lesion size and region.     

Physical properties of amorphous Mo-doped In–Ga–Zn–O films grown by magnetron co-sputtering technique

Amorphous thin films of In–Ga–Zn–O (a-IGZO) doped with Mo have been fabricated by using magnetron co-sputtering technique. The Mo concentration in a-IGZO films was modulated by varying the sputtering power applied on the Mo target. The electrical, optical and magnetic properties of Mo-doped a-IGZO films grown on glasses were investigated. The carrier density and mobility of a-IGZO films can be remarkably enhanced by low concentration Mo doping. On the other hand, the optical bandgap of a-IGZO films is not significantly affected by Mo doping. However, the transmission is decreased with increasing the Mo doping. Moreover, all Mo-doped films exhibit room-temperature ferromagnetism.     

A Nanostructuring Method to Decouple Electrical and Thermal Transport through the Formation of Electrically Triggered Conductive Nanofilaments

Transforming thermal energy into electric energy and vice versa needs the decoupling of electrical transport from thermal transport. An innovative strategy is proposed by forming/disrupting electrically triggered conductive nanofilaments within semiconducting thin films to switch thermoelectric properties between two states without further material modification and manufacturing processes. It can also controllably adjust the degree of decoupling, providing a potential resolution and performance adjustability for heat/coldness control or power consumption reduction on demand.