Reliable and cost effective design of intermetallic Ni2Si nanowires and direct characterization of its mechanical properties

We report that a single crystal Ni2 Si nanowire (NW) of intermetallic compound can be reliably designed using simple three-step processes: casting a ternary Cu-Ni-Si alloy, nucleate and growth of Ni2 Si NWs as embedded in the alloy matrix via designing discontinuous precipitation (DP) of Ni2 Si nanoparticles and thermal aging, and finally chemical etching to decouple the Ni2 Si NWs from the alloy matrix. By direct application of uniaxial tensile tests to the Ni2 Si NW we characterize its mechanical properties, which were rarely reported in previous literatures. Using integrated studies of first principles density functional theory (DFT) calculations, high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDX) we accurately validate the experimental measurements. Our results indicate that our simple three-step method enables to design brittle Ni2 Si NW with high tensile strength of 3.0 GPa and elastic modulus of 60.6GPa. We propose that the systematic methodology pursued in this paper significantly contributes to opening innovative processes to design various kinds of low dimensional nanomaterials leading to advancement of frontiers in nanotechnology and related industry sectors.1

Fabrication of Photofunctional Nanoporous Membrane and Its Photoinactivation Effect of Vesicular Stomatitis Virus

Fabrication and photophysical study of photofunctional nanoporous alumina membrane (PNAM) were performed, and its application of photodynamic antimicrobial chemotherapy (PACT) was investigated. Nanoporous alumina membrane (NAM) was fabricated by two-step aluminium anodic oxidation process. Surface of the fabricated NAM was modified with organo-silane agent to induce covalent bonding between NAM and a photosensitizer (PtCP: [5,10,15-triphenyl-20-(4-methoxycarbonylphenyl)-porphyrin] platinum). PtCP was covalently bonded to the surface of the modified NAM by nucleophilic acyl substitution reaction process. The morphology and the photophysical properties of the fabricated PNAM were confirmed with field emission scanning electron microscope (FE-SEM), steady-state spectroscopies, and nanosecond laser-induced time-resolved spectroscopy. For the efficacy study of PNAM in PACT, an enveloped animal virus, vesicular stomatitis virus (VSV), was utilized as a target organism. Antiviral effect of the PNAM-PACT was measured by the extent of suppression of plaque-forming units (PFU) after the light irradiation. In the cultures inoculated with PACT-treated VSV, the suppression of PFU was prominent, which demonstrates that PNAM is a potential bio clean-up tool

Catecholamines May Play an Important Role in the Pathogenesis of Transient Mid- and Basal Ventricular Ballooning Syndrome

The exact pathogenesis of transient mid- and basal ventricular ballooning, a new variant of transient left ventricular (LV) ballooning, remains unknown. We report two cases of transient mid- and basal ventricular ballooning associated with catecholamines. These cases suggest that catecholamine-mediated myocardial dysfunction might be a potential mechanism of this syndrome

Intradiscal Electrothermal Treatment for Chronic Lower Back Pain Patients with Internal Disc Disruption

Chronic lower back pain is one of the most common musculoskeletal problems; it is also the most expensive industrial injury. Not surprisingly, many treatments have been developed to combat this expensive and debilitating condition. One of these, intradiscal electrothermal treatment (IDET), was developed for patients with chronic discogenic lower back pain who failed to improve with any of the wide variety of non-surgical treatments. The present study sought to evaluate the efficacy of IDET for patients with chronic lower back pain. Twenty-five patients were enrolled in this prospective study; the patients received IDET between June 2001 and June 2003. MRI was used to confirm the diagnosis of internal disc disruption in all patients. The patients then underwent a pre-operative provocative test and discography. The follow-up duration was at least 1 year in all cases, and the visual analogue scale, recovery rate, and satisfaction of each patient were evaluated. The average age of the patients was 32 years (age range 18 to 49 years), and the patient group was 33% male and 67% female. Of the 25 patients, 5 underwent lumbar fusion surgery within 1 year of IDET. After IDET, 8 patients (32%) reported more pain than before, 14 patients (56%) reported less pain, and 3 patients (12%) experienced no change. Twelve patients (48%) were satisfied with IDET, 11 (44%) were dissatisfied, and 2 (8%) were undecided about the treatment. At least 1 year after IDET, nearly half the study patients were dissatisfied with their medical outcome. Consequently, 5 patients (20%) underwent fusion surgery at 1 year after IDET. Although other studies have shown good results with IDET for at least 2 years, this investigation suggests the IDET may be somewhat less effective. In order to firmly establish the efficacy of IDET for treating chronic discogenic lower back pain, additional studies with larger numbers of patients evaluated over longer time periods are recommended

A Successful Primary Percutaneous Coronary Intervention Twelve Days After a Cabrol Composite Graft Operation in Marfan Syndrome

The Cabrol procedure is one of several techniques used for re-implantation of a coronary artery. After replacement of the ascending aorta and aortic valve using a composite graft, second Dacron tube grafts are used for anastomosis between the ascending aortic graft and the coronary arteries. Ostial stenosis is one of the complications associated with the Cabrol operation. However, there have been no reported cases of acute thrombosis of a Cabrol graft. Here we report a case with acute ST elevation myocardial infarction due to thrombotic total occlusion of a right Cabrol graft-to-right coronary artery (RCA) twelve days after surgery in a patient with Marfan syndrome. He was successfully treated with primary percutaneous coronary intervention (PCI)

The Effect of Chlamydia pneumoniae on the Expression of Peroxisome Proliferator-Activated Receptor-γ in Vascular Smooth Muscle Cells

Purpose: This study was designed to investigate the change of peroxisome proliferator-activated receptor gamma (PPAR γ) after the infection of the human coronary artery smooth muscle cells (HCSMCs) with Chlamydia pneumoniae (C. pneumoniae) and the effect of PPARγ agonist on the expres-sion of PPARγ of C. pneumoniae-infected HCSMCs. Materials and Methods: To determine the effect of PPARγ agonist on the proliferation of C. pneumoniae-infected HCSMCs, rosiglitazone at various concentrations was applied 1 hour before inoculation of HCSMCs. Results: The expression of PPARγ mRNA in HCSMCs increased from 3 hours after C. pneumoniae infection and reached that of noninfected HCSMCs at 24 hours (p < 0.05). The expression of PPARγ protein in HCSMCs also increased from 3 hours after C. pneumoniae and persisted until 24 hours as compared with that of noninfected HCSMCs (p < 0.05). The pretreatment of HCSMCs with rosiglitazone followed by the infection with C. pneumoniae augmented the expression of PPARγ mRNA and protein (p < 0.05) and decreased cell proliferation. Conclusion: Our results showed that the expression of PPARγ increases in response to C. pneumoniae infection and rosiglitazone further augmented the expression of PPAR γ. It is suggested that rosiglitazone could ameliorate the chronic inflammation in the vessel wall induced by C. pneumoniae by augmenting PPARγ expression. Key Words: C. pneumoniae, peroxisome proliferator-activated receptor gamma, rosiglitazone, atherosclerosi