Control of Spatial Organization of Gold Nanoparticles Using Cylindrical Nanopores of Block Copolymers Films

Abstract In this paper, a sequential process of elaboration of hybrid nanostructured composite films has been proposed. The combination of phase separation in poly(styrene-block-4vinylpyridine) (PS-P4VP) block copolymer leading to the formation of nanopores, and gold nanocolloids synthesis confined in the nanoholes has allowed the facile fabrication of hexagonally arranged gold nanoparticles (NPs) onto silicon wafer. In particular, the nucleation and growth of gold nanoparticles took place within the nanopores, where they are confined in both size and shape the formed Au NPs. The resulting hybrid nanoscomposite has been characterized by Atomic Force Microscopy (AFM) and X-Ray Spectroscopy (XPS). This facile and simple process represents an opened pathway to several technologically important materials fabrication such as hierarchical and ordered crystal architectures. Indeed, the approach based on solvent phase, which is particularly attractive due to its low energy requirement, and the safety and environmentally gentle processing conditions

Changing patterns in long-term noninvasive ventilation: a 7-year prospective study in the Geneva Lake area

STUDY OBJECTIVES: To describe a 7-year follow-up (1992 to 2000) of patients who were treated by home nasal positive-pressure ventilation (NPPV) for chronic hypercapnic respiratory failure. DESIGN: Prospective descriptive study. SETTING: Two university hospitals and a pulmonary rehabilitation center. PATIENTS: Two hundred eleven patients with obstructive pulmonary disorders (58 patients) or restrictive pulmonary disorders (post-tuberculosis, 23 patients; neuromuscular diseases [NM], 28 patients; post-poliomyelitis syndrome, 12 patients; kyphoscoliosis [KYPH], 19 patients; obesity-hypoventilation syndrome [OHS], 71 patients) who were treated by long-term NPPV. INTERVENTION: Annual, elective, standardized medical evaluations. MEASUREMENTS: Pulmonary function tests, arterial blood gas levels, health status, compliance, survival and probability of pursuing NPPV, and hospitalization rates. RESULTS: Patients with OHS, NM, and KYPH had the highest probability of pursuing NPPV, while patients with COPD had the lowest values. Overall, the compliance rate was high (noncompliance rate, 15%). As of 1994, COPD and OHS became the most frequent indications for NPPV, increasing regularly, while other indications remained stable. The use of pressure-cycled ventilators progressively replaced that of volume-cycled ventilators in most indications. Hospitalization rates decreased in all groups after initiating NPPV, when compared with the year before NPPV, for up to 2 years in COPD patients, and 5 years in non-COPD patients. CONCLUSION: Major changes in patient selection for NPPV occurred during the study period with a marked increase in COPD and OHS. The shift toward less expensive pressure-cycled ventilators and the decrease in hospitalizations after initiating NPPV have had positive impacts on the cost-effectiveness of NPPV in patients with chronic respiratory failure

Changing patterns in long-term noninvasive ventilation: a 7-year prospective study in the Geneva Lake area

STUDY OBJECTIVES: To describe a 7-year follow-up (1992 to 2000) of patients who were treated by home nasal positive-pressure ventilation (NPPV) for chronic hypercapnic respiratory failure. DESIGN: Prospective descriptive study. SETTING: Two university hospitals and a pulmonary rehabilitation center. PATIENTS: Two hundred eleven patients with obstructive pulmonary disorders (58 patients) or restrictive pulmonary disorders (post-tuberculosis, 23 patients; neuromuscular diseases [NM], 28 patients; post-poliomyelitis syndrome, 12 patients; kyphoscoliosis [KYPH], 19 patients; obesity-hypoventilation syndrome [OHS], 71 patients) who were treated by long-term NPPV. INTERVENTION: Annual, elective, standardized medical evaluations. MEASUREMENTS: Pulmonary function tests, arterial blood gas levels, health status, compliance, survival and probability of pursuing NPPV, and hospitalization rates. RESULTS: Patients with OHS, NM, and KYPH had the highest probability of pursuing NPPV, while patients with COPD had the lowest values. Overall, the compliance rate was high (noncompliance rate, 15%). As of 1994, COPD and OHS became the most frequent indications for NPPV, increasing regularly, while other indications remained stable. The use of pressure-cycled ventilators progressively replaced that of volume-cycled ventilators in most indications. Hospitalization rates decreased in all groups after initiating NPPV, when compared with the year before NPPV, for up to 2 years in COPD patients, and 5 years in non-COPD patients. CONCLUSION: Major changes in patient selection for NPPV occurred during the study period with a marked increase in COPD and OHS. The shift toward less expensive pressure-cycled ventilators and the decrease in hospitalizations after initiating NPPV have had positive impacts on the cost-effectiveness of NPPV in patients with chronic respiratory failure

Epitaxy of Si nanocrystals by molecular beam epitaxy on a crystalline insulator LaAlO3(001)

We have studied the Si initial growth mechanisms on LaAlO3(0 0 1), a crystalline oxide with a high dielectric constant (high-kappa material). The clean LaAlO3(0 0 1) substrate exhibits a c(2 x 2) reconstruction that can be attributed to surface O vacancies. Si deposit by molecular beam epitaxy was studied as a function of both deposition temperature and thickness. Epitaxy was obtained only above 550 degrees C. In this case, a Volmer-Weber mode is observed. The associated nanodots are relaxed and formed by pure Si as ascertained by the Si-2s XPS peak, which remains for 1 and 10 ML at the binding energy corresponding to Si-Si bonds. Moreover the islands have an abrupt interface with the LaAlO3(0 0 1) substrate without the formation of silicate or silica. A unique epitaxial relationship between LaAlO3 and the crystallized Si islands is pointed out by RHEED and confirmed by HRTEM, where the Si(0 0 1) planes are parallel to the LaAlO3(0 0 1) ones, but rotated by 45 degrees in the [0 0 1] direction. This orientation leads to mismatch and strain minimization of the Si film. (C) 2010 Elsevier B.V. All rights reserved

Gold electrodeposition for microelectronic, optoelectronic and microsystem applications

The electrodeposition of gold is a key technology in the fabrication of many microelectronic, optoelectronic and microsystem devices. In this review, we examine some recent applications, and consider the suitability of various gold plating systems for device fabrication. The properties of gold cyanide and sulfite baths and their limitations are considered first. This is followed by an analysis of the latest generation of non-cyanide baths, including the thiosulfate, sulfite-thiosulfate and ammonium gold systems. Plating baths containing mercapto-alkylsulfonic acid and hydantoin ligands are also briefly discussed. Finally an analysis of the stability of gold plating baths is presented