An improved model for rosen type piezoelectric transformer for power converter

Piezoelectric transformer is attractive because of its small thickness. Rosen Type piezoelectric transformer has high step-up ratio which is advantageous for high voltage power converters. In most cases the load has a range of variable resistances that can greatly affect the output characteristic of a piezoelectric transformer. The conventional model is not sufficient to model the gain characteristics with a wide load range. In this paper a modified model is presented. A simple fictitious resistor is employed to modify the conventional model and it produces excellent match with measurements. Experimental measurements are given to show the merits of the proposed model.published_or_final_versio

Analysis of parallel connection of Rosen type piezoelectric transformers

Single layer Rosen type piezoelectric transformer is an attractive component for portable high voltage applications because of its small thickness and low cost. It is favorable for applications such as LCD backlight cold cathode fluorescent lamp converters where thickness is an important feature. In general piezoelectric transformer can produce low output power only and this is a major drawback in many applications where more power is needed. A promising solution is parallel connection of several transformers. In this paper parallel connection of piezoelectric transformers is investigated and discussed. A simple model is produced which allows representation of characteristics of parallel Rosen type piezoelectric transformers. Comparisons with experimental result verify the model. This model provides engineers with a simple and useful design tool.published_or_final_versio

A microprocessor controlled piezoelectric power converter

Piezoelectric transformer (PT) for power conversion is receiving more and more attention because of its small thickness and high energy density. A major challenge of PT converter is the resonant characteristic of the PT that affects the performance of the whole converter. This paper presents a microprocessor controlled piezoelectric power converter system for Cold Cathode Fluorescent Lamp (CCFL) that can provide stable output around the resonant point of the PT. A micro-controller based control algorithm is introduced to provide frequency tracking. Experimental results are presented and illustrate that this system is suitable for such application.published_or_final_versio

Hepatic cancer stem cell marker granulin-epithelin precursor and β-catenin expression associate with recurrence in hepatocellular carcinoma

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Differential-phase-shift quantum key distribution using heralded narrow-band single photons

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The Association of Types of Training and Practice Settings with Doctors’ Empathy and Patient Enablement among Patients with Chronic Illness in Hong Kong

Background The increase in non-communicable disease (NCD) is becoming a global health problem and there is an increasing need for primary care doctors to look after these patients although whether family doctors are adequately trained and prepared is unknown. Objective This study aimed to determine if doctors with family medicine (FM) training are associated with enhanced empathy in consultation and enablement for patients with chronic illness as compared to doctors with internal medicine training or without any postgraduate training in different clinic settings. Methods This was a cross-sectional questionnaire survey using the validated Chinese version of the Consultation and Relational Empathy (CARE) Measure as well as Patient Enablement Instrument (PEI) for evaluation of quality and outcome of care. 14 doctors from hospital specialist clinics (7 with family medicine training, and 7 with internal medicine training) and 13 doctors from primary care clinics (7 with family medicine training, and 6 without specialist training) were recruited. In total, they consulted 823 patients with chronic illness. The CARE Measure and PEI scores were compared amongst doctors in these clinics with different training background: family medicine training, internal medicine training and those without specialist training. Generalized estimation equation (GEE) was used to account for cluster effects of patients nested with doctors. Results Within similar clinic settings, FM trained doctors had higher CARE score than doctors with no FM training. In hospital clinics, the difference of the mean CARE score for doctors who had family medicine training (39.2, SD = 7.04) and internal medicine training (35.5, SD = 8.92) was statistically significant after adjusting for consultation time and gender of the patient. In the community care clinics, the mean CARE score for doctors with family medicine training and those without specialist training were 32.1 (SD = 7.95) and 29.2 (SD = 7.43) respectively, but the difference was not found to be significant. For PEI, patients receiving care from doctors in the hospital clinics scored significantly higher than those in the community clinics, but there was no significant difference in PEI between patients receiving care from doctors with different training backgrounds within similar clinic setting. Conclusion Family medicine training was associated with higher patient perceived empathy for chronic illness patients in the hospital clinics. Patient enablement appeared to be associated with clinic settings but not doctors' training background. Training in family medicine and a clinic environment that enables more patient doctor time might help in enhancing doctors' empathy and enablement for chronic illness patients.published_or_final_versio

Anode modification of polyfluorene-based polymer light-emitting devices

A glycerol-modified poly(3,4-ethylene dioxythiophene) (PEDOT): poly(styrene sulfonate) (PSS) layer was used as an anode buffer layer in polymer light-emitting devices using poly(9,9-dioctylfluorene) (F8) as the emitter. Devices with a configuration of indium tin oxide/PEDOT:PSS (with or without glycerol)/F8/CsF/Al were fabricated. It was found that the glycerol-modified device showed a much larger current density than the unmodified device. At an operating voltage of 6 V, the glycerol-modified device showed a luminance of 1300Cd/m 2 and a current efficiency of 1.7 Cd/A compared to the corresponding values of 500Cd/m 2 and 1.3 Cd/A in the unmodified device. Analysis by ultraviolet spectroscopy suggests that the two devices have the same energy level structure and the performance improvement should not be due to change in the PEDOT/polymer interface. It was further found that incorporating a suitable amount of glycerol into the PEDOT:PSS layer can increase its conductivity by six times. This leads to a better balance in the hole and electron currents and thus improved device efficiency. © 2002 American Institute of Physics.published_or_final_versio

Long-term results after liver transplantation for primary hepatic epithelioid hemangioendothelioma

Background: Hepatic epithelioid hemangioendothelioma (PHEHE) is a multifocal, low-grade malignant neoplasia characterized by its epithelial-like appearance and vascular endothelial histogenesis. The outcome of 16 patients treated with orthotopic liver transplantation (OLT) is the subject of this report. Methods: A retrospective study of 16 patients with HEHE (7 men, 9 women) with ages ranging from 24 to 58 years (mean 37 ± 10.6 years). Follow-up intervals ranged from 1 to 15 years (median of 4.5 years). Results: Actual patient survival at 1, 3, and 5 years was 100, 87.5, and 71.3%, respectively. Disease-free survival at 1, 3, and 5 years was 81.3, 68.8, and 60.2%, respectively. The 90-day operative mortality was 0. Involvement of the hilar lymph nodes or vascular invasion did not affect survival. The 5-year survival of HEHE compares favorably with that of hepatocellular carcinoma at the same stage (stage 4A): 71.3 versus 9.8% (p=0.001) Conclusions: The long-term survival obtained in this series justifies OLT for these tumors even in the presence of limited extrahepatic disease. © 1995 The Society of Surgical Oncology, Inc

Assessing the Consultation and Relational Empathy (CARE) Measure in sexual health nurses' consultations

Background: Increasingly healthcare policies emphasise the importance of person-centred, empathic care. Consequently, healthcare professionals are expected to demonstrate the ‘human’ aspects of care in training and in practice. The Consultation and Relational Empathy (CARE) Measure is a patient-rated measure of the interpersonal skills of healthcare practitioners. It has been widely validated for use by healthcare professionals in both primary and secondary care. This paper reports on the validity and reliability of the CARE Measure with sexual health nurses. Methods: Patient questionnaires were collected for 943 consultations with 20 sexual health nurses. Participating patients self-completed the questionnaire immediately after the encounter with the nurse. The questionnaire included the ten item CARE Measure, the Patient Enablement Index, and overall satisfaction instruments. Construct validity was assessed through Spearman’s correlation and principal component analysis. Internal consistence was assessed through Cronbach’s alpha and the inter-rater reliability through Generalisability Theory. Data were collected in 2013 in Scotland. Results: Female patients completed 68% of the questionnaires. The mean patient age was 28.8 years (standard deviation 9.8 years). Two of the 20 participating nurses withdrew from the study. Most patients (71.7%) regarded the CARE Measure items as very important to their consultation and the number of ‘not applicable’ and missing responses’ were low (2.6% and 0.1% respectively). The participating nurses had high CARE Measure scores; out of a maximum possible score of 50, the overall mean CARE measure score was 47.8 (standard deviation 4.4). The scores were moderately correlated with patient enablement (rho = 0.232, p = 0.001) and overall satisfaction (rho = 0.377, p = 0.001. Cronbach’s alpha showed the measure’s high internal consistency (Cronbach’s alpha coefficient = 0.95), but the inter-rater reliability could not be calculated due to the high achieved CARE Measure scores that varied little between nurses. Conclusions: Within this clinical context the CARE Measure has high perceived relevance and face validity. The findings support construct validity and some evidence of reliability. The high CARE Measure scores may have been due to sample bias. A future study which ensures a representative sample of patients on a larger group of nurses is required to determine whether the measure can discriminate between nurses

Granulin-epithelin precursor interacts with 78-kDa glucose-regulated protein in hepatocellular carcinoma

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