Phase Diversity For Speckle Reduction

B-mode ultrasound images are characterised by speckle artefact, which results from interference effects between returning echoes, and may make the interpretation of images difficult. Consequently, many methods have been developed to reduce this problematic feature. One widely used method, popular in both medical and non-destructive-testing applications, is a 1D method known as Split Spectrum Processing (SSP), or also as Frequency Diversity. Alhough this method was designed for speckle reduction applications, the final image experiences a resultant loss of resolution, impinging a trade-off between speckle reduction and resolution loss. In order to overcome this problem, we have developed a new method that is an extension of SSP to 2D data using directive filters, called Split Phase Processing (SPP). Instead of using ID narrow band-pass filters as in the SSP method, we use 2D directive filters to split the RF ultrasound image in a set of wide band images with different phases. The use of such filters substantially avoids the resolution loss usually associated with SSP for speckle reduction, because they effectively have the same bandwidth as the original image. It is concluded that the Split Phase Processing, as introduced here, provides a significant improvement over the conventional Split Spectrum Processing.5035414422Burckhardt, C.B., Speckle in ultrasound b-mode scans (1978) IEEE Trans. Sonics and Ultrasonics, 25 (1), pp. 1-6. , JanuaryChen, Y., Yin, R., Hynn, P., Broschat, S., Aggressive region growing for speckle reduction in ultrasound images (2003) Pattern Recognition Letters, 24 (4-5), pp. 677-691. , FebruaryGehlbach, S.M., (1983) Pulse Reflection Imaging and Acoustic Speckle, , Ph.D. dissertation, Stanford UniversityHealey, A.J., Leeman, S., Ferrari, L.A., Removing the ambiguity from single image speckle reduction techniques (1996) Acoustical Imaging, 22, pp. 145-150Li, P.C., Odonnell, M., Evaluational spatial compounding (1994) Ultrasonic Imaging, 16 (3), pp. 176-189Shankar, P.M., Newhouse, V.L., Speckle reduction with improved resolution in ultrasound images (1985) IEEE Trans. Sonics and Ultrasonics, 32 (4), pp. 537-543. , Jul

Epidermal growth factor receptor variant III mediates head and neck cancer cell invasion via STAT3 activation.

Epidermal growth factor receptor (EGFR) is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) where aberrant signaling downstream of this receptor contributes to tumor growth. EGFR variant III (EGFRvIII) is the most commonly altered form of EGFR and contains a truncated ligand-binding domain. We previously reported that EGFRvIII is expressed in up to 40% of HNSCC tumors where it is associated with increased proliferation, tumor growth and chemoresistance to antitumor drugs including the EGFR-targeting monoclonal antibody cetuximab. Cetuximab was FDA-approved in 2006 for HNSCC but has not been shown to prevent invasion or metastasis. This study was undertaken to evaluate the mechanisms of EGFRvIII-mediated cell motility and invasion in HNSCC. We found that EGFRvIII induced HNSCC cell migration and invasion in conjunction with increased signal transducer and activator of transcription 3 (STAT3) activation, which was not abrogated by cetuximab treatment. Further investigation showed that EGF-induced expression of the STAT3 target gene HIF1-α, was abolished by cetuximab in HNSCC cells expressing wild-type EGFR under hypoxic conditions, but not in EGFRvIII-expressing HNSCC cells. These results suggest that EGFRvIII mediates HNSCC cell migration and invasion by increased STAT3 activation and induction of HIF1-α, which contribute to cetuximab resistance in EGFRvIII-expressing HNSCC tumors

Determination of Iron and Zinc Absorption by Local Isolates of Saccharomyces cerevisiae to Produce Iron and Zinc in Organic Form

Iron (Fe) and Zinc (Zn) play important role in health both of live stock and human. Fe and Zn in organic form were claimed increasing their viabilities. They bind to certain amino acid formed as a product of microbial metabolism. The Amount Fe and Zn absorbed may indicated the Fe and Zn organic produced. The aim of the study is to determine the absorption of microelement of Fe and Zn by local isolates of Saccharomyces cerevisiae to produce Fe and Zn in organic forms. S. cerevisae BCC F0205, BCC F0206, and BCC F0214 were treated with Fe or Zn 10 ppm to obtain S. cerevisae which has the highest of total concentration of Fe and Zn. Selected isolate was then treated with Fe or Zn respectively 2.5, 5, 10 ppm and their combination. Fe and Zn absorbed by isolates were measured by Atomic Absorption Spectrophotometer (AAS). The results show that  S. cerevisae BCC F0205, BCC F0206, and BCC F0214 treated with 10 ppm Fe or Zn contained total concentration of Fe respectively 1.57, 3.07, 2.24 ppm  and total concentration of Zn respectively 2.34, 3.20, 3.13 ppm. Then, S. cerevisae BCC F0206 treated with 2.5, 5, 10 ppm Fe or Zn, absorbed Fe 1.45, 0.50, 0.94 ppm and Zn 0.73, 0.38, 0.53 ppm respectively. Furthermore, combination of Fe and Zn (2.5:2.5, 5:5, 10:10 ppm) produce absorption of Fe 3.10, 2.13, 3.67 ppm and Zn 0.11, 0.10, 0.28 ppm per gram S. cerevisae BCC F0206. Percentages of absorption by S. cerevisae are up to 100% for Fe and up to 47.20% for Zn. In conclusion, this study indicated that S. cerevisae BCC F0206 absorb Fe and Zn higher than BCC F0205 and BCC F0214 and there are antagonistic interactions found between Fe and Zn in this research

Magnetic and electronic properties of M-Ba-Cu-O (M: Y, Er, Eu)

Various high-Tc superconductors of the La-(Ba,Sr)-Cu-O and the M-Ba-Cu-O systems with M = Y, Er, and Eu have been prepared by the solid-state reaction method. Single-phase samples with no additional diffraction peaks as verified by x-ray diffraction (XRD) measurements have been obtained. Measurements of the electrical resistivity and of the magnetization showed sharp superconducting transitions with a width of 1 K. The measurements of the magnetic susceptibility have been extended above room temperature up to 770 K. There is clear evidence for the formation of a magnetic moment in all M-Ba-Cu-O samples. Monochromated x-ray photoelectron spectroscopy (MXPS) valence band and x-ray photoelectron spectroscopy (XPS) core level spectra have been measured on various samples at room temperature and at liquid nitrogen temperatur

A Single-Center Comparison of Extended and Restricted THROMBOPROPHYLAXIS with LMWH after Metabolic Surgery

IntroductionMorbid obesity is an important risk factor for developing a venous thromboembolic events (VTE) after surgery. Fast-track protocols in metabolic surgery can lower the risk of VTE in the postoperative period by reducing the immobilization period. Administration of thromboprophylaxis can be a burden for patients. This study aims to compare extended to restricted thromboprophylaxis with low molecular weight heparin (LMWH) for patients undergoing metabolic surgery.MethodsIn this single center retrospective cohort study, data was collected from patients undergoing a primary Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2014 and 2018. Patients operated in 2014-2017 received thromboprophylaxis for two weeks. In 2018, patients only received thromboprophylaxis during hospital admission. Patients already using anticoagulants were analyzed as a separate subgroup. The primary outcome measure was the rate of clinically significant VTEs within three months. Secondary outcome measures were postoperative hemorrhage and reoperations for hemorrhage.Results3666 Patients underwent a primary RYGB or SG following the fast-track protocol. In total, two patients in the 2014-2017 cohort were diagnosed with VTE versus zero patients in the 2018 cohort. In the historic group, 34/2599 (1.3%) hemorrhages occurred and in the recent cohort 8/720 (1.1%). Postoperative hemorrhage rates did not differ between the two cohorts (multivariable analysis, p=0.475). In the subgroup of patients using anticoagulants, 21/347(6.1%) patients developed a postoperative hemorrhage. Anticoagulant use was a significant predictor of postoperative hemorrhage (

Single-vortex-induced voltage steps in Josephson-junction arrays

We have numerically and analytically studied ac+dc driven Josephson-junction arrays with a single vortex or with a single vortex-antivortex pair present. We find single-vortex steps in the voltage versus current characteristics (I-V) of the array. They correspond microscopically to a single vortex phase-locked to move a fixed number of plaquettes per period of the ac driving current. In underdamped arrays we find vortex motion period doubling on the steps. We observe subharmonic steps in both underdamped and overdamped arrays. We successfully compare these results with a phenomenological model of vortex motion with a nonlinear viscosity. The I-V of an array with a vortex-antivortex pair displays fractional voltage steps. A possible connection of these results to present day experiments is also discussed.Comment: 10 pages double sided with figures included in the text. To appear in Journal of Physics, Condensed Matte