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The present study examined the association between pre-service teachers’ mindfulness and critical thinking dispositions, as indexed by engagement, cognitive maturity, and innovativeness in critical thinking. A total of 72 Chinese pre-service teachers were recruited from Hong Kong to complete an online questionnaire cross-sectionally. Hierarchical regression analysis indicated that mindfulness was differentially associated with critical thinking dispositions. As important dimensions of mindfulness, mindful presence was positively associated with engagement in critical thinking, whereas mindful acceptance was positively associated with cognitive maturity in the regression models. However, neither mindful presence nor mindful acceptance was related to innovativeness in critical thinking. As a covariate, gender was not related to dimensions of mindfulness and critical thinking dispositions. The present findings inform the literature on the relation between pre-service teachers’ mindfulness and critical thinking dispositions, particularly in the Chinese context. As a major implication, policymakers should be made aware of the importance of strengthening pre-service teachers’ mindfulness, such that they could have a greater disposition to teach critically as they enter the workforce. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus bacteremia is common and associated with fatality rates approximating 25%. We provide a brief overview of S. aureus bacteremia from a clinical and microbiological lens and review the relevant evidence and literature gaps in its management. Using a case-based approach, evidence and clinical judgement are meshed to highlight and justify the 5 core interventions that ought to be performed for all cases of S. aureus bacteremia: 1) appropriate anti-staphylococcal therapy, 2) screening echocardiography, 3) assessment for metastatic phenomena and source control, 4) decision on duration of antimicrobial therapy, and 5) Infectious Diseases consultation. [ABSTRACT FROM AUTHOR]

Bacterial prostatitis is a highly prevalent infection responsible for significant morbidity among men. The diagnosis and treatment for bacterial prostatitis remains complicated. The difficulty in diagnosis is in part owing to the paucity of high-quality evidence that guides a clinician's interpretation of patients' history, physical examination, and laboratory findings. Treatment is challenging because of the few antimicrobials capable of prostate penetration, growing antimicrobial resistance limiting effective treatment options, and the high risk of recurrence. We aimed to provide a useful resource for clinicians in effectively diagnosing and managing acute bacterial prostatitis (ABP) and chronic bacterial prostatitis (CBP). A PubMed literature search on prostatitis was performed with no restrictions on publication date. The epidemiology, pathophysiology, diagnosis, and treatment for ABP and CBP are explored using a clinical vignette as relevant context. Bacterial prostatitis can be diagnosed through a focused history and microbiological investigations. The Meares-Stamey 4-glass test or modified 2-glass test can help confirm the diagnosis if uncertainty exists. Typical uropathogens are common contributors to bacterial prostatitis but there is growing interest in exploring the role atypical and traditional non-pathogenic organisms may have. Fluoroquinolones remain first-line therapy, followed by trimethoprim-sulfamethoxazole (TMP-SMX) or doxycycline if the pathogen is susceptible. Fosfomycin has emerged as a repurposed and useful agent because of the increasing incidence of multidrug-resistant pathogens. Selection of appropriate antimicrobial regimens can be challenging and is dependent on the host, chronicity of symptoms, uropathogens' susceptibilities, antimicrobials' side effect profile, and the presence of prostatic abscesses or calcifications. ABP can typically be treated similar to other complicated urinary tract infections. However, CBP requires prolonged therapy, with a minimum of 4 weeks and up to 12 weeks of therapy. [ABSTRACT FROM AUTHOR]

In this article, the open-circuit fault-tolerant operation of a multimode stacked switch rectifier leg is presented and investigated. A fault-tolerant control technique is proposed through the built-in circuit redundancy operation of the presented multimode stacked switch rectifier leg. A bidirectional CLLC resonant dc–dc converter that employs the presented leg is used to demonstrate the features of the presented control scheme. The proposed control can allow post fault operation of the converter to continue to deliver the demanded load power with soft-switching operation in case any switch experiences an open-circuit fault. In addition, the built-in circuit redundancy of the leg allows the resonant converter to operate in different operating modes, resulting in an enhanced control in regulating the output voltage while avoiding the switching frequency to diverge far from the resonant frequency, leading to better performance and improved efficiency with the complete soft-switching operation before and after the fault. To highlight the merits of the proposed fault-tolerant control in the multimode stacked switch rectifier leg, experimental results are provided on a 300-W resonant converter prototype with an input of 250 V and an output voltage of 400 V. [ABSTRACT FROM AUTHOR]

This article from the Canadian Medical Association Journal discusses access site-related infections in patients receiving dialysis. Infection is a leading cause of hospital admission and the second most common cause of death in these patients. Hemodialysis and peritoneal dialysis access sites can serve as entry points for bacteremia and peritonitis. The incidence rates of these infections are 0.42 episodes per patient-year for hemodialysis-associated bacteremia and 0.3 episodes per patient-year for PD peritonitis. Staphylococcus species are the most common bacteria implicated in these infections, and empiric methicillin-resistant Staphylococcus aureus (MRSA) coverage is recommended. Treatment includes antimicrobial therapy and possible line removal, and consultation with infectious disease specialists can aid in treatment decisions. Catheter removal is reserved for certain cases of peritonitis. [Extracted from the article]

Background: Pyogenic liver abscess (PLA), although uncommon in North America, is associated with significant morbidity and mortality. We sought to re-examine the epidemiology, risk factors, and outcomes of PLA in a large, diverse Canadian health zone.Methods: All Calgary Health Zone (CHZ) residents aged ≥20 with PLA between 2015 and 2017 were identified. Incidence and mortality rates were calculated using census data. Risk factors for PLA were identified using a multivariate analysis. Data was compared to 1999-2003 data, also collected in the CHZ.Results: There were 136 patients diagnosed with PLA between 2015 and 2017. Incidence rate during this period increased significantly relative to 1999-2003 (3.7 vs 2.3 cases/100,000 population, p < 0.01), however, mortality rates remained similar. The microbiological composition of PLA did not change over this 15-year time period but the number of antimicrobial resistant isolates did increase (8% vs 1%, p = 0.04). The greatest risk factors for PLA relative to general populations included current malignancy, liver-transplant, end-stage renal disease, and cirrhosis. Thirty-day mortality was 7.4% and independent risk factors included polymicrobial bacteremia, absence of abscess drainage, congestive-heart failure, a history of liver disease, and admission bilirubin.Conclusions: Pyogenic liver abscess is a health concern with rising incidence rate. The increasing prevalence of comorbidities in our population and factors that are associated with risk of PLA suggests this will continue to be an emerging diagnosis of concern. Increasing prevalence of antibiotic resistant organisms compounding unclear optimal treatment regimens is an issue that requires urgent study. [ABSTRACT FROM AUTHOR]

This article proposed a multiport converter (MPC) configuration for a photovoltaic (PV) battery system. In the proposed design, the battery charging and discharging circuits are integrated with the PV power optimizer through high-frequency ac link. The proposed converter system is capable of regulating the output voltage, following battery charging profile and tracking the maximum power point (MPP) of each PV module. Variable switching frequency is used to achieve maximum power point tracking in this design. All the switches of the converter are able to achieve soft-switching turn-on and turn-off at different operating conditions. The operating principles and the control strategy of the proposed converter are presented. Simulation results and experimental results on a 175-W system are presented to validate the features of the proposed converter. [ABSTRACT FROM AUTHOR]

Infective endocarditis (IE) has been increasingly recognized as an important complication of Staphylococcus aureus bacteremia (SAB), leading to a low threshold for echocardiography and extended treatment with anti-staphylococcal agents. However, outside of IE, many indications for prolonged anti-staphylococcal therapy courses are present. We sought to determine the frequency in which findings from a transesophageal echocardiogram (TEE) changed clinical SAB management in a large Canadian health region. Residents (> 18 years) with SAB from 2012 to 2014 who underwent transthoracic echocardiogram (TTE) and TEE were assessed. Patients potentially benefiting from an extended course of anti-staphylococcal agents were defined a priori. Patient demographics, treatment (including surgical), and clinical outcomes were extracted and evaluated. Of the 705 episodes of SAB that underwent a screening echocardiogram, 203 episodes underwent both a TTE and TEE, of which 92.1% (187/203) contained an a priori indication for extended anti-staphylococcal therapy. Regardless of TEE results, actual duration of therapy did not differ in SAB episodes that had ≥ 1 extended anti-staphylococcal therapy criteria (36.7 days, IQR 23.4–48.6 vs. 43.8 days, IQR 33.3–49.5, p = 0.17). Additionally, there were no cases in which TEE was utilized as the sole reason to shorten duration of therapy or proceed to surgery for those with SAB. Routine performance of TEE may be unnecessary in all SAB as many patients have pre-existing indications for extended anti-staphylococcal therapy independent of TEE findings. An algorithm to selectively identify cases of SAB that would benefit from TEE can reduce resource and equipment expenditure and patient risks associated with TEE. [ABSTRACT FROM AUTHOR]

In this article, a hybrid high voltage gain converter module for medium voltage dc conversion in wind energy systems is proposed. The converter consists of step-up resonant circuit with coupled voltage-quadruplers to achieve the step-up voltage conversion function. The coupled voltage-quadrupler modules are connected to the resonant circuit via a 1:1:1 high frequency transformer. As a result, high turns ratio transformers are not required in the proposed design while at the same time, the output voltage of each voltage-quadrupler is well balanced due to the shared coupled-inductor. All the primary side silicon carbide (SiC) MOSFETs and secondary side SiC diodes exhibit zero switching losses. The output voltage of the converter module is controlled with variable frequency control. Simulation results on a 4 MW modular design of SiC-based converter system with 3.3 kV/18 kV, 670 kW per module, and experimental results on a laboratory-scale prototype with per-module rating: 500 V/2.7 kV, 3.7 kW are provided to validate the theoretical analysis and to highlight the merits of the proposed work. Results confirmed that a peak efficiency of close to 99% is achieved in both simulation and experimental works. [ABSTRACT FROM AUTHOR]

Introduction: Pelvic MRI has an increasingly important role in the evaluation of non-malignant uterine pathology including uterine leiomyomas, adenomyosis and endometriosis. Normal physiological myometrial junctional zone transient contractions can also be identified on MRI and have the potential to act as pathology mimics. This study aims to evaluate both the incidence of visible physiological contractions in premenopausal female pelvic MRI and also to support the routine acquisition of a repeat T2 sagittal sequence to differentiate transient physiological contractions from true underlying pathology and therefore improve observer confidence.Methods: A total of 279 female patients of child-bearing age who had undergone a pelvic MRI over a 16 month period met the inclusion criteria. All patients underwent a standard examination protocol on the same hardware. This included performing two separate T2-weighted sagittal sequences as part of the protocol firstly as the initial and then as the final series for the examination. The sagittal series were reviewed separately by four readers and conclusions made for each case with regards to the presence of identifiable contractions on one or both series and their potential to act as pathology mimics.Results: Of the 279 cases, there were 34 cases (12.2%) that were found to have transient junctional zone contractions acting as pathology mimics, resembling either leiomyomata or adenomyosis.Conclusions: Standard MRI sequences need to be able to distinguish normal transient physiological uterine contractions from true pathology to avoid diagnostic error. The routine utility of a repeat T2-weighted sagittal sequence performed at the conclusion of a patient's examination was shown to improve reader confidence in distinguishing transient contractions from true uterine pathology while adding minimal time penalty to the overall examination. It is therefore advocated that all premenopausal female pelvic MRI cases have a T2 sagittal series as the initial and then the final series as part of a routine protocol. [ABSTRACT FROM AUTHOR]

In this article, a novel power factor correction, soft-switched, bridgeless ac–dc converter is presented for step-up voltage conversion in medium voltage dc grid applications. To reduce the number of conversion stages, the proposed bridgeless boost rectifier is integrated with isolated high-frequency step-up resonant converter with voltage multiplier modules to form a single-stage ac–dc step-up converter. Almost sinusoidal input currents with near unity power factor are achieved at the three-phase ac input side, while at the same time, the converter achieves a very high voltage gain at the output. The proposed converter is able to reduce the number of lossy diodes required for the front-end rectifier, and to achieve soft switching for all the Silicon Carbide (SiC) mosfets and SiC diodes, thus enhancing the converter efficiency. Simulation results on a 100-kW, 1-kVac/15-kVdc design, and experimental results on a laboratory scale proof-of-concept 2-kW, 250-Vac/4-kVdc medium voltage prototype are presented to verify with the proposed converter's performance. [ABSTRACT FROM AUTHOR]

In this article, a new bidirectional dc/dc converter topology based on a hybrid string-inverter/rectifier structure with an isolated CLLC resonant circuit is presented for energy storage applications. In this topology, a novel inverter/rectifier leg is presented that enables this circuit to operate in rectifying mode with much lower voltage ripple compared to the standard four-switch string rectifier circuit with the same capacitive filter. Compared to the dual-active-bridge circuit structure, the proposed inverter/rectifier leg is able to reduce the number of high-voltage switches required. A CLLC resonant circuit is employed to step-up/down the dc voltage levels. The operating principles of the proposed converter are discussed in this article. Silicon Carbide switches are used in both legs of the proposed converter, with zero-voltage switching turn-on and zero-current switching (ZCS) turn-off realized for all switches, whereas ZCS turn-on and off are achieved for all diodes. Simulation and experimental results are provided on a 1-kW, 100-kHz, 400-V/700-V converter system to highlight the merits of the proposed converter. Experimental results demonstrated that an efficiency of close to 97% is achieved in the proposed converter in both boost mode and buck mode at the full-load condition. [ABSTRACT FROM AUTHOR]

Context.-- Large B-cell lymphomas represent the most common non-Hodgkin lymphomas and often present as extranodal masses with advanced stage similar to metastatic tumors. Without proper intraoperative, microscopic, immunophenotypic, and cytogenetic evaluation they may be mistaken for other hematopoietic or even nonhematopoietic tumors. Also, diffuse large B-cell lymphomas often have clinical, morphologic, immunophenotypic, and cytogenetic clinical features that are similar to those of other less common B-cell lymphomas. Furthermore, classification of these neoplasms is continually becoming more refined. Objective.-- To provide a rational, methodic approach to the evaluation of large B-cell lymphomas for community practice pathologists who provide general pathology services. Data Sources.-- This review incorporates guidelines detailed in the 2017 update to the World Health Organization's Classification of Tumours of Haematopoietic and Lymphoid Tissues in addition to other recent peer-reviewed publications. Conclusions.-- Many large B-cell neoplasms respond favorably to current treatments, but these cases also require accurate and timely diagnoses. We propose a process following a brief checklist that focuses on diffuse large B-cell lymphoma, the most common entity, and rules out other similar lymphomas in a stepwise fashion. [ABSTRACT FROM AUTHOR]

In this paper, a new step-up dc–dc converter module that consists of three resonant submodules interconnecting with 1:1 turns ratio three-phase transformer and coupled current-fed voltage doubler modules is presented for medium voltage dc converter design in wind energy application. By utilizing step-up resonant circuits with three-phase transformer and combining it with a “multistring” inverter, the proposed circuit structure completely utilizes all the switching circuits to transfer power to the output. In addition, the proposed topology is able to achieve high voltage gain without using large turns ratio high frequency step-up transformers. Zero voltage switching turn-on and near zero current switching (ZCS) turn-off are maintained for all the switches. A modular 1.5 MW, 1 kV (dc-link), 20 kV (output) converter system is presented to validate the performance of the proposed circuit. Experimental results on a laboratory-scale 2.8 kW, 0.3 kV (dc-link), 6 kV (output), prototype are provided to highlight the merits of this work. Silicon Carbide (SiC) MOSFETs and SiC Schottky diodes are utilized in both designs. Results confirm that a peak efficiency of 97.6% is achieved in the prototype. [ABSTRACT FROM AUTHOR]

Reports on the magnetic hysteresis of a rectangular lattice of interacting single-domain ferromagnetic spheres. Effect of interparticle interaction on the Stoner-Wohlfarth theory of magnetic hysteresis in single-domain particles; Anisotropy energy of the spheres; Rectangular lattice of single-domain, ferromagnetic spheres.

Presents a study which calculated the longitudinal dielectric constant of a rectangular lattice of parallel conducting prolate spheroids. Derivation of matrix equation; Evaluation of matrix elements; Numerical results.

Presents a solution to the general problem of surface-wave reflection and refraction at an impedance discontinuity. Formulation of the infinite plane surface; Details on the solution; Discussion of findings.

Presents a study that calculated the effective dielectric constant and the effective magnetic permeability of a cubic lattice with conducting magnetic spheres. Derivation of the matrix equations; Determination of the effective dielectric constant; Details of the iterative solution.

Presents a study which calculated the effective magnetic permeability of a simple cubic lattice of conducting magnetic sphere in the quasistatic limit including the eddy current effect. Formulation of the problem; Derivation of matrix equation; Magnetic permeability.

This paper presents a new modular ac/dc step-up soft-switched converter with unity turns ratio high-frequency transformers for medium-voltage (MV) dc grid in wind energy systems. In the proposed converter, the three-phase boost rectifier is combined with step-up resonant circuits and high-gain output rectifier modules (called voltage quadrupler modules) to form a modular step-up power conversion unit. As a result, the proposed converter is able to achieve very high voltage gain without using any medium-to-high frequency transformers with very large turns ratio, which greatly simplifies the insulation requirement and design of the high-frequency transformer. In addition, soft-switching operations are achieved in all the semiconductor devices to maintain high efficiency. The techniques to ensure voltage balancing across the dc-link capacitors and to achieve output short-circuit protection will be discussed in this paper. To realize high-frequency MV operation, silicon carbide (SiC) devices are utilized in the converter implementation on a 1.5 MW, 690 VAC/40 kV converter system to validate the performance of the proposed circuit. Experimental results on a 3.5 kW, 145 VAC/6.2 kV, 95.4% efficiency SiC-based laboratory-scale proof-of-concept prototype are then provided to highlight the merits of this work. [ABSTRACT FROM AUTHOR]

In order to provide a constant current to the Light-emitting diodes (LEDs) and to minimize the size and cost of the driver circuit in ac/dc offline LED drivers, electrolytic capacitors are conventionally used due to their high energy density and low cost. However, electrolytic capacitors are sensitive to operating temperature and have much shorter lifetime than the LED semiconductor devices. This paper proposes an improved control scheme that is capable to control the output LED current and regulate the dc-link capacitor's energy simultaneously for a family of single-stage soft-switched high power factor LED driver topologies. Each of these topologies consists of an integrated power factor correction (PFC) circuit. Due to the proposed controller's capability to control the LED current directly via variable frequency control and the dc-link capacitor's voltage via duty ratio control, the required energy storage capacitance can be significantly reduced, thereby allowing small size film capacitor to be used as the energy storage capacitor. Simulation results are provided on two different LED driver topologies, one with an integrated boost PFC stage and the other one with an integrated buck–boost PFC stage, to verify the performance of the proposed control scheme. Experimental results are also been provided on a 12-W prototype to highlight the merits of this paper. [ABSTRACT FROM PUBLISHER]

Presents a study that examined the zero-field muon-spin relaxation in (yttrium[sub1-x] praseodymium[subx]) barium[sub2 copper[sub3] oxygen[suby]. Methods; Discussion of muon-spin relaxation; Conclusion.

Background: Neurocysticercosis occurs when the eggs of the pork tapeworm (Taenia solium) migrate and hatch into larvae within the central nervous system. Neurocysticercosis is the most common cause of seizures in the developing world and is characterized on brain imaging by cysts in different stages of evolution. In Canada, cases of neurocysticercosis are rare and most of these patients acquire the disease outside of Canada. We report the case of a patient with multiple intracranial lesions whose history and diagnostic imaging were consistent with neurocysticercosis. Pathological investigations ultimately demonstrated that her brain lesions were secondary to malignancy. Brain metastases are considered to be the most common cause of intracranial cystic lesions. Case Presentation: We present the case of a 60-year-old Canadian-born Caucasian woman with a subacute history of ataxia, lower extremity hyper-reflexia, and otalgia who resided near a pig farm for most of her childhood. Computed tomography and magnetic resonance imaging showed that she had multiple heterogeneous intracranial cysts, suggestive of neurocysticercosis. Despite a heavy burden of disease, serological tests for cysticercosis were negative. This result and a lack of the central scolices on neuroimaging that are pathognomonic of neurocysticercosis prompted whole-body computed tomography imaging to identify another etiology. The whole-body computed tomography revealed right hilar lymphadenopathy associated with soft tissue nodules in her chest wall and abdomen. A biopsy of an anterior chest wall nodule demonstrated high-grade poorly differentiated carcinoma with necrosis, which stained strongly positive for thyroid transcription factor-1 and synaptophysin on immunohistochemistry. A diagnosis of stage 4 metastatic small cell neuroendocrine carcinoma was made and our patient was referred for oncological palliative treatment. Conclusions: This case illustrates the importance of the diagnostic approach to intracranial lesions. Our patient's diagnosis of neuroendocrine carcinoma was delayed because of her nontraditional presentation. Despite extensive metastatic burden, the lack of perilesional edema and the identification of lesions appearing to be in various stages of development led to a pursuit of neurocysticercosis as the diagnosis. The absence of constitutional symptoms should not discount the possibility of malignancy from the differential diagnosis. [ABSTRACT FROM AUTHOR]

Background: Pulmonary exacerbations (PEx) are critical events in cystic fibrosis (CF), responsible for reduced quality of life and permanent loss of lung function. Approximately 1/4 of PEx are associated with failure to recover lung function and/or resolve symptoms. Developing tools to optimize PEx treatment is of paramount importance. Methods: We retrospectively audited all adults infected with Pseudomonas aeruginosa, experiencing PEx necessitating parenteral antibiotic therapy from 2006-2012 from our center. Quantitative analysis of sputum at admission, twice-weekly during hospitalization, and end of therapy were compared to baseline (most recent healthy) and follow-up (after PEx) samples. Change in P. aeruginosa burden from baseline was assessed for any and all morphotypes (ALL), as well as mucoid (MUC) and non-mucoid (NON) isolates specifically. PEx were identified as failures if >90% of baseline pulmonary function was not recovered. Results: Forty-six patients meeting the above inclusion and exclusion criteria experienced 144 PEx during this time (median 3, IQR 2-6). Patients were treated for a median 14 days (IQR 13-16). No increase in ALL, MUC or NON were detected at PEx, nor was there an association between change in sputum density and magnitude of lung function decline. PEx failures were observed in 30% of events. Reductions of at least 1-log and 2 log P. aeruginosa sputum density was observed in 57% and 46% (ALL), 73% and 55% (MUC) and 58% and 46% (NON) of PEx, respectively. Factors associated with greater reduction of P. aeruginosa sputum density included choice of β-lactam antibiotic, antibiotics with in vitro predicted activity and treatment duration. PEx associated with reductions in P. aeruginosa sputum density were not associated with a reduced risk of PEx failure. Conclusions: Enhanced killing of P. aeruginosa during PEx does not predict improved clinical outcomes. Studies accounting for the polymicrobial nature of CF respiratory disease and the heterogeneity of P. aeruginosa causing chronic infection may enable the identification of a more appropriate pathogen(s) based biomarker of PEx outcomes. [ABSTRACT FROM AUTHOR]

Light emitting diode (LED) lamps with ac-input (50 or 60 Hz) usually require an electrolytic capacitor as the dc-link capacitor in the driver circuit to: 1) balance the energy between the input and output power, and 2) to minimize the low-frequency component of the output ripple across the LEDs. The lifetime of this capacitor, however, is much shorter than that of a LED. To maximize the potential lifetime of the LED lighting system, a new pulsating current driving LED driver that does not require any electrolytic capacitors or complicated control circuits to minimize the low-frequency (i.e., 100 or 120 Hz) output ripple is proposed in this paper. The proposed circuit is simple and a single-switch topology is designed to simplify the controller design. The proposed circuit is able to reduce the energy storage capacitance to a few microfarads range, so that film capacitor can be used to replace the unreliable electrolytic capacitor. The circuit operating principles and its theoretical analysis are provided in this paper. Simulation and experimental results are given on a 9-W LED lamp to highlight the merits of the proposed circuit. [ABSTRACT FROM AUTHOR]

With the global concerns on the issue of how to conserve the limited energy resources, compact fluorescent lamps (CFLs) have been forced in a lot of countries to replace the power-hungry incandescent lamps to reduce the energy cost. However, conventional passive power factor corrected electronic ballasts used in CFLs suffer two major drawbacks: 1) they are unable to achieve close-to-unity power factor and 2) they are unable to provide the same amount of light intensity under fluctuating line voltage. This paper proposed a simple lamp power regulation method for a very high-power factor single-switch electronic ballast, which allows the electronic ballast to maintain almost constant lamp power at its full-power condition for a wide range of the input voltage by controlling the dc-link voltage of the ballast power circuit through duty ratio control. When a TRIAC phase-cut dimmer is used to dim the CFL, the dc-link voltage regulation control loop is deactivated; so that the lamp power decreases accordingly during dimming. The analysis and operating principles of the controller are discussed in this paper. MATLAB, PSIM simulation, and experimental results are provided to highlight the merits of the proposed work. [ABSTRACT FROM AUTHOR]

Although compact fluorescent lamps (CFLs) have been on the market for a long time, many of them do not achieve the same power factor as the incandescent lamps do, which presents a significant problem for the utility with the current widespread use of CFLs for household lightings. A simple single-switch electronic ballast with passive valley-fill power factor correction is proposed in this paper for CFL application. The proposed single-switch ballast circuit is able to achieve zero current switching to maximize the circuit efficiency. A simple feedback circuit with duty ratio control is also proposed to improve the high lamp current crest factor caused by the valley-fill circuit. Detailed descriptions and analysis of the circuit operating principles are provided in this paper. Simulation and experimental results are given on a 13-W CFL tube from Osram Sylvania to highlight the merits of the proposed work. [ABSTRACT FROM PUBLISHER]

Background: Candidemia is increasing in frequency and is associated with high mortality. We sought to determine the burden of illness, the population it affects and its resistance profile in our region. Methods: The Calgary Zone (CZ) provides all care for residents of Calgary and surrounding communities (~ 1.69 million) via five tertiary hospitals each served by a common single laboratory for acute care microbiology. All adult patients in the CZ with at least one Candida spp.-positive blood culture between January 1, 2010, and December 31, 2018, were identified using microbiological data from Calgary Lab Services, the laboratory that processes > 95% of all blood culture samples in the CZ, were reviewed for the study. Results: The overall annual incidence of candidemia among individuals living in the CZ was 3.8 per 100,000 persons (Median age 61 years (IQR 48–72) and 221/455 (47.4%) were female). C. albicans was the most common species (50.6%), followed by C. glabrata, (24.0%). No other species accounted for more than 7% of cases. Overall mortality at 30, 90, and 365 days was 32.2, 40.1, and 48.1% respectively. Mortality rate did not differ by Candida species. Of individuals who developed candidemia, more than 50% died within the next year. No new resistance pattern has emerged in the most common Candida species in Calgary, Alberta. Conclusions: In Calgary, Alberta, the incidence of candidemia has not increased in the last decade. C. albicans was the most common species and it remains susceptible to fluconazole. [ABSTRACT FROM AUTHOR]

This paper proposes a novel multifunctional controller for a dimmable high-power-factor single-switch electronic ballast that can be used with standard phase-cut dimmers. Conventional dimmable electronic ballasts lack the ability to 1) provide smooth dimming and maintain high power factor when phase-cut dimmers are used and 2) regulate the lamp power when the input line voltage varies. A digital controller with multiple control functions is proposed in this paper. The proposed controller allows high power factor to be achieved by controlling the duty cycle during dimming with standard phase-cut dimmers. On the other hand, when dimming is not required, the lamp power is regulated through the regulation of the dc-link voltage. Additional control functions, such as lamp low-power cutoff operation, and protection function are also implemented inside the digital controller. The descriptions of the controller operating principles and its logic flow diagrams are provided in this paper. PSIM simulation and experimental results are provided on a 13-W compact fluorescent lamp to highlight the merits of the proposed work. [ABSTRACT FROM AUTHOR]

This study examined prospective reciprocity between psychological distress and subjective well-being and the role of change in psychosocial resources in the reciprocity in the year following cancer diagnosis. Psychological distress (Hospital Anxiety and Depression Scale), subjective well-being (Chinese Affect Scale and Satisfaction with Life Scale), and psychosocial resources of 180 Chinese patients were assessed at diagnosis (Time 1) and at 3-month (Time 2) and 12-month (Time 3) follow-up. Cross-lagged panel analysis demonstrated significant cross-lagged effects between psychological distress and subjective well-being. Time 2 to Time 3 change in perceived collective control (i.e., control over cancer in collaboration with close social partners) significantly mediated the cross-lagged effect of Time 2 well-being on Time 3 distress, and the mediating effect was stronger at medium or higher Time 2 distress. The findings suggest that whereas distress and well-being reciprocally predict each other throughout cancer adaptation, change in perceived collective control could mediate the prospective relationship of well-being with subsequent distress. [ABSTRACT FROM AUTHOR]

A novel dimmable high-power-factor compact fluorescent lamp (CFL) electronic ballast that is compatible with standard incandescent lamp dimmers is proposed in this paper. In the proposed system, the dimming controller uses the phase angle of the dimmer as the input feedforward parameter for the duty ratio control of the switch in the power circuit. As a result, a wide range of light output can be achieved with a small range of phase angles of the phase-cut dimmer. The ballast power circuit is a single-switch single-stage resonant inverter, which is essentially a fusion of a SEPIC converter and a single-switch current-fed inverter. Detailed operating principles of the proposed system will be discussed in this paper. System stability analysis that includes the effects of the phase-cut dimmer is also provided. Experimental results are given for a 13-W CFL to demonstrate and highlight the merits of the proposed work. [ABSTRACT FROM AUTHOR]

A novel single-stage single-switch electronic ballast topology with a unity power factor is presented in this paper. The proposed circuit consists of an integrated buck–boost stage that operates in the discontinuous conduction mode to provide a high power factor and a single-switch current-fed resonant inverter to stabilize the lamp current. The proposed topology presents a low cost and compact electronic ballast design method. The detailed descriptions of the circuit's operating principles are provided in this paper. The design equations and mathematical analysis regarding the proposed circuit are discussed in this paper. The proposed ballast has been tested with an 18-W compact fluorescent lamp, and the experimental results confirmed that a very high power factor of 0.995 and an efficiency of 83.4% have been achieved. [ABSTRACT FROM PUBLISHER]

A very high power factor electronic ballast that uses a single switch in the power circuit is proposed in this paper for compact fluorescent lamps (CFLs). The proposed power circuit is designed by integrating a SEPIC power factor corrector with a novel single-switch current-fed resonant inverter. The advantage of this single-switch electronic ballast is that it greatly simplifies the gate-drive circuit design due to the elimination of isolation devices that are otherwise required in the conventional half-bridge totem pole configuration. This topology features a reduction of at least two switches in the power stage compared to conventional two-stage approach for high-power-factor electronic ballasts. In addition, the proposed circuit is also able to achieve close-to-unity power factor by operating the integrated SEPIC power factor corrector in discontinuous conduction mode. The conduction loss of the switch in the proposed circuit is also significantly reduced compared to the conventional class-E single-switch resonant inverter. Experimental results are provided to justify all the theoretical analysis and highlight the features of the proposed circuit on a 13-W CFL. [ABSTRACT FROM AUTHOR]

A single-stage dimmable electronic ballast with very high power factor and high efficiency is presented in this paper. A compact lamp power circuit is designed by integrating a buck-boost power factor corrector with a current-fed resonant inverter. This integration produces a single power-processing unit that minimizes the number of circuit components. The proposed resonant inverter reduces the circulating current in the resonant tank and allows simple gate drivers to be used so that isolation devices can be eliminated. With the buck-boost stage operating in the discontinuous conduction mode (DCM), a close-to-unity power factor is achieved for different lamp-power conditions. A small-signal analysis is presented, and a simple variable frequency controller is developed using the modified 555 timer to provide dimming operations. Simulation and experimental waveforms are provided to highlight the merits of the proposed circuit for a 40-W compact fluorescent lamp. [ABSTRACT FROM AUTHOR]

Abstract: Patient''s history, physical examination, laboratory tests, and radiographic evaluation are the cornerstones of postoperative surveillance. It has been shown that localized renal cell carcinoma (RCC) can recur in nearly all organs of the body, but most commonly in the lung, bone, liver, brain, and renal fossa. Lung metastases can be sensitively detected through radiographic evaluation. Treatment of lung metastases might prolong survival, which supports surveillance x-ray or computed tomography scans. Surgical treatment of early detected liver metastases and local recurrences may also prolong survival, which supports a close abdominal surveillance program. Brain and bone metastases are usually symptomatic when they occur, and their treatment is generally palliative. Hence, surveillance protocols do not usually include their routine radiographic evaluation. Because partial nephrectomy does not increase the risk of local recurrence over radical nephrectomy, we recommend identical surveillance for completely resected tumors regardless of surgical approach. The risk of recurrence after nephrectomy is generally related to tumor stage, tumor grade, and patient performance status. The majority of recurrences occur within the first 5 years after surgery, supporting a more intense surveillance strategy within the first 5 years. The University of California Integrated Staging System (UISS) combines TNM stage, Fuhrman grade, and performance status, and categorizes patients into 3 different risk groups. The current surveillance protocol at our institution is based on the UISS. It is expected that molecular markers such as p53 will allow more individualized surveillance strategies in the future. [Copyright &y& Elsevier]

In this paper, a modified valley fill (VF) circuit is employed to combine with a current-fed resonant inverter as a passive high power factor (PF) electronic ballast. A conventional VF circuit limits the line current to conduct when the conduction angles are: 30° ≤ wt ≤ 150° and 210° ≤ wt ≤ 330° during the line period, which results in high total harmonic distortion (THD), The modified VF circuit has the following advantage: When the capacitors are connected in parallel, the voltage across the capacitors is one-third of the peak voltage, which allows the conduction angle of the line current to be further extended to 19.5° ≤wt ≤ 160.5° and 199.5° ≤wt ≤ 340.5°, so that a lower THD can be achieved. The high lamp crest factor (CF) problem generated by the high ripple voltage from the modified VF circuit is improved in the proposed ballast as variable frequency control is employed to continuously regulate the lamp current. An experimental prototype is then built in the laboratory to verify the feasibility of the proposed work for a 26-W compact fluorescent lamp. The final results confirm that a PF of 0.986 and a lamp CF of 1.49 are achieved with the proposed circuit, whereas a PF of 0.96 is achieved with the conventional VF ballast. [ABSTRACT FROM AUTHOR]

Abstract: Over the past 2 decades, a greater understanding of the basic biology and genetics of kidney cancer has occurred. Surgical techniques have also evolved, and technological advances have made possible new methods of managing renal tumors. The most extensively used system to provide prognostic information for renal cell carcinoma (RCC) is currently the tumor, nodes, metastasis (TNM) staging system. Emerging data over the last few years has questioned whether further revisions are needed and if improvements can be made with the introduction of new, more accurate and predictive prognostic factors. The recent discovery of molecular tumor biomarkers are expected to revolutionize the staging of RCC and potentially lead to the development of new therapies based on molecular targeting. This review will examine the current staging modalities and prognostic factors associated with RCC as well as the selection of patients most likely to benefit from clinical trials. [Copyright &y& Elsevier]

Resonant inverters are connected to a high-frequency ac (HFAC) bus, where power is delivered to different locations for points-of-use power management. Such a power distribution system subjects to more perturbations and load uncertainties than inverters operating with single load. A novel voltage control method is proposed in this paper for a high-frequency full-bridge resonant inverter with series-parallel resonant tank. A modified one-cycle controlled phase-shift modulation is proposed to effectively compensate the input line variations. The uncertainty model of the high frequency resonant inverter is developed and analyzed with the resonant circuit component tolerance, input line and load variations taken into design considerations. The voltage feedback controller is designed based on the H∞ robust control theory and is implemented with analog discrete devices. The proposed control scheme has the advantages of fast response for both input line and load perturbations. It also ensures a wide range of system stability and guarantees robustness of the power converter. Both simulations and experimental results are provided to verify with the theoretical analysis through an experimental prototype of a full-bridge resonant inverter with an output power of 150-W operating at 1 MHz and an output voltage of 28 V (rms). [ABSTRACT FROM AUTHOR]

Abstract: Objective: To evaluate the prognostic role of tumour size in pathological stage T3a renal cell carcinoma (RCC) with fat invasion only and to assess whether this subgroup maintains its relevance over the other pathological stages. Methods: We retrospectively studied 2113 patients from eight international institutions who were treated by surgical resection for T2–4 RCC. Disease-specific survival (DSS) was evaluated with univariate and multivariate analyses. Results: Univariate analysis of patients with T3a RCC showed that tumour size was significantly associated with DSS (HR: 1.09, 95% CI: 1.05–1.12, p <0.001). An ideal cut-off of 7cm for these patients was identified with a scatter plot of Martingale residuals and tumour size. The two T3a groups were distinctly different with respect to clinicopathologic parameters (performance status, metastases, grade, histological subtype) and survival (p <0.001). Median survival time was not reached for patients with T2 and T3a≤7cm disease with a 5- and 10-yr DSS rate of 70% and 59% and 63% and 53%, respectively. Median survival time for patients with T3a>7cm, T3b, T3c, and T4 disease was 54, 46, 21, and 11 mo, respectively, with 5- and 10-yr DSS rates of 46% and 36%, 46% and 36%, 34% and 0%, and 16% and 14%, respectively. Conclusions: Our data indicate that tumour size is an important factor for predicting outcome of patients with T3a RCC with fat invasion only. Our findings should merit consideration during the next revision of the TNM classification. [Copyright &y& Elsevier]

OBJECTIVE To investigate the expression and potential clinical usefulness of structure-specific flap endonuclease 1 (FEN-1) in human primary prostate cancer using tissue microarray technology, as FEN-1 was recently identified to be overexpressed in CL1.1, the most aggressive clone generated from the hormone-refractory prostate cancer cell line CL1. MATERIALS AND METHODS Immunohistochemistry was performed on tissue microarrays constructed from paraffin-embedded specimens of primary prostate cancer from 246 patients who had had a radical prostatectomy. Prostatic intraepithelial neoplasia (PIN), benign prostatic hyperplasia (BPH) and normal prostate epithelium were represented on the array. FEN-1 nuclear expression was scored based on the percentage of target cells staining positively, and correlated with Gleason score, preoperative prostate-specific antigen (PSA) level and pathological stage. The time to PSA recurrence was also analysed. RESULTS The mean expression of FEN-1 was significantly higher in cancer (36.7%) than in normal (13.2%), BPH (4.5%) and PIN (15.4%) specimens ( P < 0.001). FEN-1 expression was significantly correlated with Gleason score (ó = 0.23, P = 0.002). A higher preoperative serum PSA level ( P = 0.015), Gleason score ≥ 7 ( P < 0.001), seminal vesicle invasion ( P < 0.001) and capsular involvement ( P = 0.004) were associated with PSA recurrence, whereas FEN-1 expression was not. In a multivariate analysis, only Gleason score ≥ 7 ( P < 0.001), seminal vesicle invasion ( P = 0.005) and capsular involvement ( P = 0.009) were retained as independent predictors for PSA recurrence. CONCLUSIONS FEN-1 is overexpressed in prostate cancer compared with matched normal prostate, and its expression increases with tumour dedifferentiation, as shown by increasing Gleason score. These results suggest that FEN-1 might be a potential marker for selecting patients at high risk, and a potential target for prostate cancer diagnosis and therapy. [ABSTRACT FROM AUTHOR]

It has been 35 years since the radical nephrectomy was standardized by the work of Robson et al. (J Urol 101:297–301, 1969). Despite being based on a retrospective review of only 88 cases operated upon over a span of 15 years, this publication was an important milestone in the attempt to create uniformity in the staging of Renal cell carcinoma (RCC), and the measurement of surgical outcomes for RCC. Although this manuscript forms the basis for our contemporary measurement of the long-term results of RCC surgery and set the standard to which the entire subsequent literature was compared, contemporary research subsequently has questioned many of Robson’s conclusions regarding RCC. In Robson’s era, the majority of patients presented with large, symptomatic tumors, pre-operative staging was imprecise, and many patients had locally advanced disease at the time of surgery: of the 88 patients in Robson’s series, 75% were managed through a thoracoabdominal incision. Since that time, advances in renal imaging and clinical staging have led to the increased detection of incidental, lower stage, organ-confined tumors more amendable to expanded surgical options. Surgical techniques have evolved and technological advances have made possible new methods of managing renal tumors in situ that have emphasized a transition from radical to less extirpative approaches. In addition, understanding of the basic biology and genetics of kidney cancer has led to improved prognostication and the development of effective immunotherapies for advanced disease. The current concepts and long-term outcomes of the surgical management of RCC will be reviewed to help elucidate some of these changes, from the evolution of open to laparoscopic to percutaneous, from radical to partial to ablative approaches. [ABSTRACT FROM AUTHOR]

Abstract: Most cancers comprise a heterogenous population of cells with marked differences in their potential to proliferate as well as the ability to reconstitute the tumor upon transplantation. Cancer stem cells are a minor population of tumor cells that possess the stem cell property of self-renewal. Dysregulation of stem cell self-renewal is a likely requirement for the development of cancer. Cell signaling pathways shared by stem cells and cancer cells lend further evidence for a possible link between these 2 populations of cells. Study of the differentiation pathways of normal and abnormal prostate growth has led to the development of a stem cell model for prostate cancer. The basal layer of the normal prostate is believed to be populated by prostate epithelial stem cells and a population of transit-amplifying cells intermediate in differentiation to the stem and fully differentiated cells. There is recent evidence suggesting that prostate cancer occurs from malignant transformation of stem/progenitor cells, thereby resisting apoptosis and spawning proliferation. This new model for prostate cancer will have significant ramifications for the way this disease is studied and treated. Furthermore, through targeting the prostate cancer stem cell and its dysregulated self-renewal, therapies for treatment of prostate cancer are likely to improve. [Copyright &y& Elsevier]

Reports on the open surgical management of renal cell carcinoma in the era of minimally invasive kidney surgery. Evidence showing that nephron-sparing surgery (NSS) for patients with small tumors is equivalent to total radical nephroctomy in terms of long-term survival; Safety and efficacy of NSS; Clinical factors determining prognosis and survival in the management of the disease.

Abstract: Recent advances in the understanding of the pathogenesis, behavior, and molecular biology of renal cell carcinoma (RCC) have paved the way for developments that may enhance early diagnosis, better predict prognosis, and improve survival. Reliable predictive factors are essential for the stratification of patients into clinically meaningful categories that can be used to provide patients with counseling regarding prognosis, select treatment modalities, and determine eligibility for clinical trials. The TNM (tumor, nodes, metastasis) staging system is currently the most extensively used staging system for RCC, but it has undergone systematic revisions as a result of emerging data. Comprehensive integrated staging systems that combine important clinical and pathological variables have been created in an attempt to improve prognostication. Although staging has improved with the development of integrated systems, the incorporation of molecular tumor markers are expected to revolutionize the staging of RCC. This article reviews the important molecular markers in RCC to date and discusses their role in the diagnosis, prognostication, and therapy of patients with RCC. [Copyright &y& Elsevier]

Reports on the adjuvant therapy of renal cell carcinoma in patient selection and therapeutic options. Renal cell carcinoma, survival and prognostic factors; Postoperative surveillance protocol for patients with localized and locally advanced renal cell carcinoma; Risk group assessment and clinical outcome algorithm to predict the natural history of patients with surgically resected renal cell carcinoma; Correlations with tumor oxygen measurements and prognostic in locally advanced carcinoma of the cervix.

The use of carbonic anhydrase IX as a promising molecular marker in RCC is described by authors from Los Angeles, who discuss the promise that molecular markers hold to improve diagnosis, staging, treatment surveillance and survival of patients with RCC. There is a whole range of new treatments being introduced in the management of metastatic renal cancer. The use of VEOF-targeted therapy has particular importance, especially as it has a strong genetically linked rationale for its potential success in this area. Authors from the USA show that substantial clinical activity has been reported in initial clinical trials. In prostate cancer, drugs targeting microtubules, such as taxanes, have already been introduced clinically, and their success has received widespread attention. A new group of drugs, the epothilones, have similar but not identical binding properties to microtubules, and authors from the USA describe how they have shown activity in hormone-refractory prostate cancer, and are moving to phase III testing. [ABSTRACT FROM AUTHOR]