Signal Processing Research Program

Contains table of contents for Part III, table of contents for Section 1, an introduction and reports on fourteen research projects.Charles S. Draper Laboratory Contract DL-H-404158U.S. Navy - Office of Naval Research Grant N00014-89-J-1489National Science Foundation Grant MIP 87-14969Battelle LaboratoriesTel-Aviv University, Department of Electronic SystemsU.S. Army Research Office Contract DAAL03-86-D-0001The Federative Republic of Brazil ScholarshipSanders Associates, Inc.Bell Northern Research, Ltd.Amoco Foundation FellowshipGeneral Electric FellowshipNational Science Foundation FellowshipU.S. Air Force - Office of Scientific Research FellowshipU.S. Navy - Office of Naval Research Grant N00014-85-K-0272Natural Science and Engineering Research Council of Canada - Science and Technology Scholarshi

Successful Percutaneous Coronary Intervention Using Intravascular Ultrasound-Guided Rewiring Technique in a Case of Spontaneous Coronary Artery Dissection Involving Left Main Bifurcation

We herein describe a 49-year-old woman without significant cardiovascular risk factors who was transferred to our hospital with sudden onset of chest pain. The patient was diagnosed with non-ST-elevation acute myocardial infarction, and coronary angiography revealed a dissection at the proximal site of the left anterior descending artery (LAD) extending from the left main trunk (LMT) suggestive of spontaneous coronary artery dissection (SCAD). Because coronary flow was impaired after contrast injection and the patient had chest pain with ST elevation, urgent percutaneous coronary intervention was performed. The first guide wire was initially introduced from the LMT to the distal LAD, but intravascular ultrasound (IVUS) imaging revealed that the guide wire had passed through the true lumen of the left coronary artery ostium, false lumen at the ostium of the left circumflex artery, and true lumen of the distal LAD. We then reinserted another guide wire using an IVUS-guided rewiring technique from the true lumen of the LMT to the distal LAD. Finally, a drug-eluting stent was deployed to cover the dissected segment, and final coronary angiography revealed acceptable results with a patent left circumflex artery. This case report highlights that physicians should consider SCAD among the differential diagnoses in patients presenting with acute coronary syndrome, particularly in young women. In the present case, IVUS played a pivotal role in not only detecting the arterial dissection but also correctly introducing the guide wire into the true lumen

Gelatin Hydrogel enhances the engraftment of transplanted Cardiomyocytes and angiogenesis to ameliorate cardiac function after myocardial infarction

Cell transplantation therapy will mean a breakthrough in resolving the donor shortage in cardiac transplantation. Cardiomyocyte (CM) transplantation, however, has been relatively inefficient in restoring cardiac function after myocardial infarction (MI) due to low engraftment of transplanted CM. In order to ameliorate engraftment of CM, the novel transplantation strategy must be invented. Gelatin hydrogel (GH) is a biodegradable water-soluble polymer gel. Gelatin is made of collagen. Although we observed that collagen strongly induced the aggregation of platelets to potentially cause coronary microembolization, GH did not enhance thrombogenicity. Therefore, GH is a suitable biomaterial in the cell therapy after heart failure. To assess the effect of GH on the improvement of cardiac function, fetal rat CM (5×106 or 1x106 cells) were transplanted with GH (10 mg/ml) to infarcted hearts. We compared this group with sham operated rats, CM in phosphate buffered saline (PBS), only PBS, and only GH-Transplanted groups. Three weeks after transplantation, cardiac function was evaluated by echocardiography. The echocardiography confirmed that transplantation of 5×106 CM with GH significantly improved cardiac systolic function, compared with the CM+PBS group (fractional area change: 75.1±3.4% vs. 60.7±5.9%, p<0.05), only PBS, and only GH groups (60.1±6.5%, 65.0±2.8%, p<0.05). Pathological analyses demonstrated that in the CM+GH group, CM were efficiently engrafted in infarcted myocardium (p<0.01) and angiogenesis was significantly enhanced (p<0.05) in both central and peripheral areas of the scar. Moreover, quantitative RT-PCR revealed that angiogenic cytokines, such as basic fibroblast growth factor, vascular endothelial growth factor, and hepatocyte growth factor, were significantly enriched in the CM+GH group (p<0.05). Here, we report that GH confined the CM effectively in infarcted myocardium after transplantation, and that CM transplanted with GH improved cardiac function with a direct contraction effect and enhanced angiogenesis

Low Temperature Deposition of TiO₂ Thin Films through Atmospheric Pressure Plasma Jet Processing

Titanium dioxide (TiO2) has been widely used as a catalyst material in different applications such as photocatalysis, solar cells, supercapacitor, and hydrogen production, due to its better chemical stability, high redox potential, wide band gap, and eco-friendly nature. In this work TiO2 thin films have been deposited onto both glass and silicon substrates by the atmospheric pressure plasma jet (APPJ) technique. The structure and morphological properties of TiO2 thin films are studied using different characterization techniques like X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and field emission scanning electron microscopy. XRD study reveals the bronze-phase of TiO2. The XPS study shows the presence of Ti, O, C, and N elements. The FE-SEM study shows the substrate surface is well covered with a nearly round shaped grain of different size. The optical study shows that all the deposited TiO2 thin films exhibit strong absorption in the ultraviolet region. The oleic acid photocatalytic decomposition study demonstrates that the water contact angle decreased from 80.22 to 27.20° under ultraviolet illumination using a TiO2 photocatalyst

Thrombogenicity and cell adhesion of gelatin hydrogel (GH).

<p>(A) Thrombogenicity of gelatin hydrogel (GH) was compared with that of collagen. In a 1500-s^-1 blood stream, non-specific aggregation took place in 1 to 2 minutes, but no aggregation was induced after 3 minutes. In a 750-s^-1 blood stream, GH induced no aggregation at all. Bars are 10 μm. (B) Cardiomyocytes (CM) were premixed with GH before transplantation. CM were stained with cardiac troponin-T and 4',6-diamidino-2-phenylindole dihydrochloride (DAPI). Most of the CM were entwined with GH, and they were distributed evenly. Bar is 100 μm.</p

Transplantation of CM with GH increased the release of angiogenic cytokines.

<p>RNA was extracted from infarcted hearts, and angiogenic factors were evaluated. Basic fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF) increased in the CM+GH group. (* P<0.05)</p

Transplantation of CM with GH improved cardiac function.

<p>(A) The representative figures of fractional area change (FAC) in the GH and CM+GH groups are shown. Only the CM+GH group showed better anterior wall motion. (B-C) Left ventricular systolic function was assessed by ejection fraction (EF), fractional shortening (FS), and FAC. All of them were significantly improved in the CM+GH group. (* P<0.05) Left ventricular internal diameter in diastole (LVDd) was elongated in all groups except sham group. Left ventricular internal diameter in systole (LVDs) was shorter in the CM+GH group. HR; heart rate.</p

GH enhanced engraftment of CM.

<p>(A-B) Cardiac sections were stained with azan to evaluate the infarcted area. The CM+GH group tended to have a smaller infarcted area. Bars are 1 mm. (C) CM were prestained with MitoTracker-Red and sections were co-stained with cardiac troponin T and DAPI. In the GH group, there were no red signals in infarcted hearts. In the CM+PBS group, few CM were engrafted in the infarcted area. In the CM+GH group, more CM remained in the infarcted area. Bars are 100 μm. (D) The number of engrafted CM was increased significantly when transplanted with GH compared with CM transplanted with PBS. (** P<0.01)</p