Use of polyethylene glycol coatings for optical fibre humidity sensing

Humidity induced change in the refractive index and thickness of the polyethylene glycol (PEG) coatings are in situ investigated for a range from 10 to 95%, using an optical waveguide spectroscopic technique. It is experimentally demonstrated that, upon humidity change, the optical and swelling characteristics of the PEG coatings can be employed to build a plastic fibre optic humidity sensor. The sensing mechanism is based on the humidity induced change in the refractive index of the PEG film, which is directly coated onto a polished segment of a plastic optical fibre with dip-coating method. It is observed that PEG, which is a highly hydrophilic material, shows no monotonic linear response to humidity but gives different characteristics for various ranges of humidity levels both in index of refraction and in thickness. It undergoes a physical phase change from a semi-crystal line structure to a gel one at around 80% relative humidity. At this phase change point, a drastic decrease occurs in the index of refraction as well as a drastic increase in the swelling of the PEG film. In addition, PEG coatings are hydrogenated in a vacuum chamber. It is observed that the hydrogen has a preventing effect on the humidity induced phase change in PEG coatings. Finally, the possibility of using PEG coatings in construction of a real plastic fibre optic humidity sensor is discussed. (C) 2008 The Optical Society of Japan

Histopathological Features of Aspirated Thrombi after Primary Percutaneous Coronary Intervention in Patients with ST-Elevation Myocardial Infarction

BACKGROUND: Plaque disruption with superimposed thrombus is the predominant mechanism responsible for the onset of acute coronary syndromes. Studies have shown that plaque disruption and thrombotic occlusion are frequently separated in time. We established the histopathological characteristics of material aspirated during primary percutaneous coronary intervention (PCI) in a large consecutive ST-elevation myocardial infarction (STEMI) population. METHODOLOGY/PRINCIPAL FINDINGS: Thrombus aspiration during primary PCI was performed in 1,362 STEMI patients. Thrombus age was classified as fresh (<1 day), lytic (1-5 days), or organized (>5 day). Further, the presence of plaque was documented. The histopathological findings were related to the clinical, angiographic, and procedural characteristics. Material could be aspirated in 1,009 patients (74%). Components of plaque were found in 395 of these patients (39%). Fresh thrombus was found in 577 of 959 patients (60%) compared to 382 patients (40%) with lytic or organized thrombi. Distal embolization was present in 21% of patients with lytic thrombus compared to 12% and 15% of patients with fresh or organized thrombus. CONCLUSIONS/SIGNIFICANCE: Material could be obtained in 74% of STEMI patients treated with thrombus aspiration during primary PCI. In 40% of patients thrombus age is older than 24 h, indicating that plaque disruption and thrombus formation occur significantly earlier than the onset of symptoms in many patients

Polyaniline/palladium nanohybrids for moisture and hydrogen detection.

Palladium nanoparticles display fascinating electronic, optical and catalytic properties, thus they can be used for various applications such as sensor fabrication. Conducting polymers such as polyaniline have also been widely used in sensor technology due to its cost effectiveness, versatility, and ease of synthesis. In this research, attention was given to unify the exceptional properties of these two materials and construct palladium nanoparticle coated polyaniline films to detect hydrogen and moisture. Electrochemical polymerization of aniline was carried out on gold sputtered epoxy resin boards. Polyaniline film was generated across a gap of 0.2 mm created by a scratch made on the gold coating prior to electrochemical polymerization. A palladium nanoparticle dispersion was prepared using sonochemical reduction method and coated on to polyaniline film using drop-drying technique. Polyaniline only films were also fabricated for comparative analysis. Sensitivity of films towards humidity and hydrogen was evaluated using impedance spectroscopy in the presence of the respective species. According to the results, polyaniline films exhibited an impedance drop in the presence of humidity and the response was significantly improved once palladium nanoparticles were incorporated. Interestingly, polyaniline only films did not respond to hydrogen. Nevertheless, palladium nanoparticle coated polyaniline films exhibited remarkable response towards hydrogen

Characterization of thermal and electrical stability of MOCVD HfO \u3csub\u3e2\u3c/sub\u3e-HfSiO\u3csub\u3e4\u3c/sub\u3e dielectric layers with polysilicon electrodes for advanced CMOS technologies

\u3cp\u3eThe thermal and electrical stability of HfO\u3csub\u3e2\u3c/sub\u3e-HfSiO\u3csub\u3e4\u3c/sub\u3e dielectric layers with polysilicon electrodes are investigated in view of their use as gate dielectrics in advanced complementary metal oxide semiconductor (CMOS) technologies. The layers were deposited on 1 nm silicon oxide layers using metallorganic chemical vapor deposition (MOCVD). In situ p-doped polysilicon electrodes were deposited using rapid thermal chemical vapor deposition and low pressure chemical vapor deposition, respectively. The influence of rapid thermal annealing and postdeposition annealing of the high-k layers was investigated using MOS capacitors. The lowest equivalent oxide thickness was around 19.3 Å with a leakage current reduction of approximately 1000 times as compared to SiO\u3csub\u3e2\u3c/sub\u3e. MOSFETs fabricated using a standard direct gate etch approach were used to study the stability of the dielectric and device properties as functions of activation anneal and implant conditions. A major problem was found to be the stability of the threshold voltage V\u3csub\u3eT\u3c/sub\u3e. After 50 consecutive I\u3csub\u3ed\u3c/sub\u3e-V \u3csub\u3eg\u3c/sub\u3e dc sweeps from -1 to +2 V, the threshold voltage of n-MOS devices shifted 50-200 mV. Using pulsed I\u3csub\u3ed\u3c/sub\u3e-V\u3csub\u3eg\u3c/sub\u3e measurement technique, a hysteresis on the order of 300-400 mV was found. Only a minor improvement was achieved by different annealing of the layers. In conclusion, it was found that these layers exhibit unacceptably high instability to provide a solution as a gate dielectric for advanced CMOS technologies.\u3c/p\u3

Electrical properties of MOCVD HfO\u3csub\u3e2\u3c/sub\u3e dielectric layers with polysilicon gate electrodes for CMOS applications

\u3cp\u3eElectrical properties of MOS capacitors using MOCVD HfO\u3csub\u3e2\u3c/sub\u3e as gate dielectric have been investigated. A 900°C 1s activation anneal of Ph-doped 680°C-RTCVD demonstrated a good compatibility with high-k layers. The best MOS capacitor is obtained with EOT=1.93 nm and Jg=1.6E-04 A/cm\u3csup\u3e2\u3c/sup\u3e at |V\u3csub\u3eFB\u3c/sub\u3e-1| which is &gt; 2 orders of magnitude lower than SiO\u3csub\u3e2\u3c/sub\u3e with Poly-Si gate. A minimal degradation of leakage current after 900°C activation anneal and low effect of temperature dependence reveal the thermal stability of MOCVD HfO\u3csub\u3e2\u3c/sub\u3e gate stack. Nevertheless, upon 1000°C activation anneal only the LPCVD poly resulted in working MOS capacitor. The found leakage current was 2 order of magnitude higher compared to a 900°C activation anneal.\u3c/p\u3

Laminated CeO\u3csub\u3e2\u3c/sub\u3e/HfO\u3csub\u3e2\u3c/sub\u3e high-k gate dielectrics grown by pulsed laser deposition in reducing ambient

\u3cp\u3eCeO\u3csub\u3e2\u3c/sub\u3e and HfO\u3csub\u3e2\u3c/sub\u3e dielectric layers were deposited in an Ar+(5%)H\u3csub\u3e2\u3c/sub\u3e gas mixture by Pulsed Laser Deposition (PLD) on Si (100). A CeO\u3csub\u3e2\u3c/sub\u3e-Ce\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e transformation is achieved by deposition in a reducing ambient. It is also shown that in-situ post deposition anneal efficiently oxidizes Ce\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e layers to CeO \u3csub\u3e2\u3c/sub\u3e. The properties of CeO\u3csub\u3e2\u3c/sub\u3e/HfO\u3csub\u3e2\u3c/sub\u3e laminated structures deposited in reducing ambient and compared with binary oxide layers of CeO\u3csub\u3e2\u3c/sub\u3e and HfO\u3csub\u3e2\u3c/sub\u3e. The effect of the layer sequence, individual layer thickness and deposition temperature on the structural and electrical properties of the laminates were investigated. It is found that the layer sequence of the laminates affects the crystallinity of the layers and changes the electrical properties. The amorphous laminate with a CeO\u3csub\u3e2\u3c/sub\u3e starting layer with 4 nm physical thickness and an EOT of 2 nm, has the lowest J@V\u3csub\u3efb\u3c/sub\u3e-1 V=1.88 × 10\u3csup\u3e-7\u3c/sup\u3e A/cm\u3csup\u3e2\u3c/sup\u3e. The best EOT-J\u3csub\u3eg\u3c/sub\u3e trade off is achieved by the laminated layers with a CeO \u3csub\u3e2\u3c/sub\u3e starting layer deposited at 520°C. copyright The Electrochemical Society.\u3c/p\u3

Clinical outcomes of complex real-world diabetic patients treated with amphilimus sirolimus-eluting stents or zotarolimus-eluting stents : A single-center registry

Objective: To assess clinical outcomes of Amphilimus Sirolimus-Eluting Stents (A-SES) as compared to Zotarolimus-Eluting Stents (ZES) in complex real-world diabetic patients. Background: Patients with diabetes mellitus represent one of the most challenging scenarios with high rates of restenosis and stent thrombosis in the current era of drug-eluting stents. Hence, we assessed the safety of A-SES versus ZES in complex diabetic patients. Methods: In this observational study, we analyzed all consecutive patients with diabetes mellitus referred to our center from November 2012 to November 2014. The primary outcome was target-lesion failure at 1-year follow-up. Results: A total of 165 consecutive diabetic patients underwent percutaneous coronary intervention with A-SES or ZES for stable coronary artery disease in our tertiary center. Using the Kaplan Meier method the cumulative incidence of target-lesion failure was 6.7% (5.9% A-SES versus 7.5% ZES, p = 0.19) at 1-year follow-up. Event-free survival at 1. year follow-up was similar (89.4% A-SES vs. 83.3% ZES, p = 0.29). Interestingly, we did not find any cases of definite-, and only one case of probable stent thrombosis in this high risk cohort. Conclusion: In this real-world registry, A-SES and ZES seems to be associated with promising 1-year clinical safety outcomes following PCI in a contemporary cohort of high-risk diabetic patients. Our results should be considered hypothesis generating, as the clinical safety of A-SES has to be confirmed in a large trial

Incidence, angiographic and clinical predictors, and impact of stent thrombosis : a 6-year survey of 6,545 consecutive patients

OBJECTIVE: We sought to determine the incidence, angiographic predictors, and impact of stent thrombosis (ST). BACKGROUND: Given the high mortality after ST, this study emphasises the importance of ongoing efforts to identify angiographic predictors of ST. METHODS: All consecutive patients with angiographically confirmed ST between 2010 and 2016 were 1:4 matched for (1) percutaneous coronary intervention (PCI) indication and (2) index date ±6 weeks to randomly selected controls. Index PCI angiograms were reassessed by two independent cardiologists. A multivariable conditional logistic regression model was built to identify independent predictors of ST. RESULTS: Of 6,545 consecutive patients undergoing PCI, 55 patients [0.84%, 95% confidence interval (CI) 0.63-1.10%] presented with definite ST. Multivariable logistic regression identified dual antiplatelet therapy (DAPT) non-use as the strongest predictor of ST (odds ratio (OR) 10.9, 95% CI 2.47-48.5, p < 0.001), followed by: stent underexpansion (OR 5.70, 95% CI 2.39-13.6, p < 0.001), lesion complexity B2/C (OR 4.32, 95% CI 1.43-13.1, p = 0.010), uncovered edge dissection (OR 4.16, 95% CI 1.47-11.8, p = 0.007), diabetes mellitus (OR 3.23, 95% CI 1.25-8.36, p = 0.016), and residual coronary artery disease at the stent edge (OR 3.02, 95% CI 1.02-8.92, p = 0.045). ST was associated with increased rates of mortality as analysed by Kaplan-Meier estimates (27.3 vs 11.3%, plog-rank < 0.001) and adjusted Cox proportional-hazard regression (hazard ratio 2.29, 95% CI 1.03-5.10, p = 0.042). CONCLUSIONS: ST remains a serious complication following PCI with a high rate of mortality. DAPT non-use was associated with the highest risk of ST, followed by various angiographic parameters and high lesion complexity

Impact of strut thickness on late luminal loss after coronary artery stent placement

To determine the influence of coronary artery stent strut thickness on angiographic late luminal loss, 663 patients were included in a single-center observational cohort after receiving an ACS Multilink stent in a native coronary vessel. At 6- to 10-month follow-up, 287 patients treated with a thin-strut stent (50 mum) had significantly less late luminal loss than 376 patients treated with a thick-strut stent (greater than or equal to90 mum) (mean 0.92 +/- 0.59 vs 1.06 +/- 0.71 mm, p = 0.011); on multivariate regression analysis, strut thickness was found to be an independent predictor for late luminal loss. (C) 2004 by Excerpta Medica, In

Eosinophilic infiltration in restenotic tissue following coronary stent implantation

OBJECTIVES: The aim of our study was to compare the histopathological features of restenotic tissue after balloon angioplasty and after stent placement. We emphasized on specific types of inflammatory cells to evaluate the type of tissue immune response in both situations. METHODS: A total of 32 patients underwent elective directional coronary atherectomy; 16 patients had restenosis after balloon angioplasty, 16 patients had in-stent restenosis (ISR). Atherectomy specimens were stained with antibodies against T cells, eosinophils, smooth muscle cell actin, macrophages and with antibodies against T cell activation markers. Quantitative morphometric analysis was performed using image analysis software. RESULTS: In-stent restenotic tissue contained more smooth muscle cells (P < 0.001), anti-CD3 positive T cells (P < 0.001) and eosinophils (P = 0.012). Anti-CD40L positive activated T cells were more numerous in ISR lesions (P = 0.003) and were frequently clustered around stent imprints in the tissue. Five ISR specimens contained grossly visible stent fragments amidst the restenotic tissue. In all cases of balloon restenosis, T cells and eosinophils (if present) were concentrated around lipid rich tissue. CONCLUSIONS: Our study indicates involvement of inflammatory responses in both types of restenosis, with significantly more eosinophils encountered in case of in-stent restenosis. In contrast with clustering of inflammatory cells around stent struts after stent placement, the inflammatory cells in balloon restenosis were located in association with lipid rich tissue, suggesting different inflammatory triggers in balloon restenosis and in-stent restenosi