Effects of annealing temperature on sensing properties of Pt/HfO2/SiC Schottky-diode hydrogen sensor

Hafnium oxide (HfO 2) is successfully used as gate insulator for fabricating Metal-Insulator-SiC (MISiC) Schottky-diode hydrogen sensor. Sensors undergone N 2 annealing at different temperatures are fabricated for investigation. The hydrogen-sensing properties of these samples are compared with each other by taking the measurements at high temperature under various hydrogen concentrations using a computer-controlled measurement system. Experimental results show that sensitivity increases with the annealing temperature. Higher annealing temperature can enhance the densification of the HfO 2 film; improve the oxide stoichiometry; and facilitate the growth of a SiO 2 interfacial layer to give better interface quality, thus causing a remarkable reduction of the current of the sensor under air ambient. The effects of hydrogen adsorption on the barrier height and hydrogen-reaction kinetics are also investigated. © 2008 IEEE.published_or_final_versio

Enhanced sensing performance of MISiC schottky-diode hydrogen sensor by using HfON as gate insulator

MISiC Schottky-diode hydrogen sensor with HfON gate insulator fabricated by NO nitridation is investigated. The hydrogen-sensing characteristics of this novel sensor are studied by doing steady-state and transient measurements at different temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that this novel sensor can rapidly respond to hydrogen variation and can give a significant response even at a low H 2 concentration of 48-ppm, e.g., a sensitivity of 81% is achieved at 450°C and 2.5 V, which is two times higher than its HfO 2 counterpart. The enhanced sensitivity of the device should be attributed to a remarkable reduction of the current of the sensor before hydrogen exposure by the NO nitridation because the NO nitridation can passivate the O vacancies in the insulator and facilitate the formation of a SiO 2 interlayer to suppress the leakage current associated with high-k materials. © 2006 IEEE.published_or_final_versio

Improved Sensing Characteristics of a Novel Pt/HfTiO2/SiC Schottky-Diode Hydrogen Sensor

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Primary endovascular treatment of post-irradiated carotid pseudoaneurysm at the skull base with the Pipeline embolization device

Background A post-irradiated carotid pseudoaneurysm at the skull base can cause life-threatening blowout syndrome. Conventional treatments include parent vessel occlusion, endovascular coiling or covered stenting. Use of the Pipeline embolization device (PED) for pseudoaneurysm exclusion at the skull base is not well described. Objective To report the clinical and angiographic outcome after using multiple PEDs to treat recently ruptured radiation-induced carotid pseudoaneurysms at the skull base. Methods Retrospective review of the clinical and angiographic records of patients who received PEDs as primary treatment for skull base carotid pseudoaneurysm between April 1, 2011 to March 31, 2013. Results Seven patients (five men, two women) with a mean age of 58 years (range 47–65) were treated in the study period. Primary treatment with the PED alone, with adjunct coil embolization in two patients, achieved immediate hemostasis in all patients, with no pseudoaneurysm rebleeding after a mean follow-up of 15.3 months (range 4–24 months). One patient had periprocedural cerebral infarction. Delayed internal carotid artery occlusion secondary to in-stent thrombosis occurred in three patients, one of whom had lacunar infarct and two remained asymptomatic. Conclusions Endovascular treatment with the PED was effective in excluding skull base post-irradiated carotid pseudoaneurysms and preventing recurrent blowout. However, the risk of ischemic complications in this group of patients was high and our experience did not support the use of flow diverters as a first-line treatment for this condition.postprin

A comparison of MISiC Schottky-diode hydrogen sensors made by NO, N 2O, or NH 3 nitridations

MISiC Schottky-diode hydrogen sensors with gate insulator grown in three different nitridation gases (nitric oxide (NO), N 2O, and NH 3) are fabricated. Steady-state and transien-t-response measurements are carried out at different temperatures and hydrogen concentrations using a computer-controlled measurement system. Experimental results show that these nitrided sensors have high sensitivity and can give a rapid and stable response over a wide range of temperature. This paper also finds that N 2O provides the fastest insulator growth with good insulator quality and hence the highest sensitivity among the three nitrided samples. The N 2O- nitrided sensor can give a significant response even at a low H 2 concentration of 48-ppm H 2 in N 2, indicating a potential application for detecting hydrogen leakage at high temperature. Moreover, the three nitrided samples respond faster than the control sample. At 300°C, the response times of the N 2O, NO, and NH 3-nitrided sample to the 48-ppm H 2 in N 2 are 11, 11, and 37 s, respectively, as compared to 65 s for the control sample without the gate insulator. © 2006 IEEE.published_or_final_versio

Parental pro-smoking practices and smoking susceptibility among children in Hong Kong

Conference Theme: Tobacco and Non-Communicable DiseasesPoster Discussion 61. Assessing the Factors that Influence Tobacco Use: no. PD-1313-21BACKGROUND: Parental influence on children smoking is well known, but most studies focused on general parenting and less on smoking-specific parental practices. We investigated the association between some parental pro-smoking practices (PPP) and children smoking susceptibility. DESIGN/METHODS: Among 100 primary schools with students viewing an anti-smoking drama performance commissioned by the Hong Kong Council on Smoking and Health in 2012/13, 7 were randomly selected and 1255 primary 2-4 students (mean age 8.5±0.02, 42.8% boys) completed an anonymous self-administered questionnaire. Fifteen specific items of PPP in the past 30 days were …published_or_final_versio

A systematic review on the anxiolytic effects of aromatherapy in people with anxiety symptoms

Purpose: We reviewed studies from 1990 to 2010 on using aromatherapy for people with anxiety or anxiety symptoms and examined their clinical effects. Methods: The review was conducted on available electronic databases to extract journal articles that evaluated the anxiolytic effects of aromatherapy for people with anxiety symptoms. Results: The results were based on 16 randomized controlled trials examining the anxiolytic effects of aromatherapy among people with anxiety symptoms. Most of the studies indicated positive effects to quell anxiety. No adverse events were reported. Conclusions: It is recommended that aromatherapy could be applied as a complementary therapy for people with anxiety symptoms. Further studies with better quality on methodology should be conducted to identify its clinical effects and the underlying biologic mechanisms. © 2011, Mary Ann Liebert, Inc.published_or_final_versio

Combined simultaneous transcranial and transsphenoidal resection of large-to-giant pituitary adenomas

Background: While large-to-giant pituitary adenomas (PAs) may be safely removed by experienced surgeons through a single route, the procedure is technically challenging. We present the outcome of a simultaneous combined transcranial and transsphenoidal approach and discuss its applications. Methods: A retrospective review was conducted on 12 consecutive patients. Surgical complications, visual and endocrinological functions, and tumour control were reviewed. Results: There were four men and eight women, with a mean age of 47.6 years. All but one patient had non-functioning PAs. The mean tumour height was 4.1 cm (range: 2.3-5.5). The predominant presenting symptoms were visual field loss in eight patients, headache in three patients and mental confusion in one patient. There was no operative mortality. Post-operative cerebrospinal fluid leakage occurred in one patient. Five of the eight patients who presented with visual field loss achieved full recovery, and three had partial improvement. Two patients developed permanent diabetes insipidus after surgery. Panhypopituitarism occurred in one patient. Gross total removal (GTR) was achieved in five, and subtotal removal (STR) in seven patients. Seven patients received post-operative external irradiation. All patients who had GTR remained tumour-free and all those with STR had stable diseases after a mean follow-up period of 53.1 months (range: 14.1-92.1). Conclusion: The simultaneous 'above and below' approach is a safe and effective surgical strategy for large-to-giant PAs, particularly when expertise in endoscopic transsphenoidal surgery is unavailable. Its use, however, should be limited to a carefully selected group of patients, and tailored to individual user's expertise and experience. © 2011 The Author(s).published_or_final_versio

High-Performance Pentacene Thin-Film Transistor With High-κ HfLaON as Gate Dielectric

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Sequential approaches for resection of clival chordoma

Free Paper 7Conference Theme: Degenerative Lumbar SpineINTRODUCTION: Chordomas are extra-axial tumours that originate from the primitive notochord. They are rare diseases that present mostly between the third and the fifth decades of life with an incidence rate of 0.08 per 100,000 in the United States. Approximately 35% of chordomas arise in the clivus of the skull base (clival chordoma). In spite of their slow-growing and non-malignant histopathological appearance, they are potentially life threatening due to their locally destructive and invasive nature. Clival chordomas are located near the spheno-occipital junction at the base of the skull, behind the sphenoid sinuses. Involvement of the surrounding cranial nerves accounts for their symptomatology. It is notorious for its high tendency of recurrence following treatment, with a reported recurrence rate of 68%. Therefore, gross total resection in combination with adjuvant radiotherapy is the standard mode of treatment …published_or_final_versio