CFD evaluation of solid oxide fuel cell performances with different fuels

The operation of solid oxide fuel cells (SOFC) fueling different types of carbon-based fuels (i.e. natural gas, biosyngas, coal gas, etc.) become one of the main topics of SOFC research in recent years. Fuel gases like methane can be steam-reformed or partially oxidized in the SOFCs. Hydrogen is produced from the reforming reaction, which has crucial impact on the performance of solid oxide fuel cells, especially on the current density, temperature distribution and the consequent thermal-stress. Mathematical modeling together with simulation is a useful approach for designing SOFCs and predicting their operation safety. With a single channel model taking direct internal reforming into account, this work aims to investigate the performance of an anode-supported intermediate temperature planar SOFC designed for methane under co- flow operation. SOFC performances with three different fuel gases are compared. The direct internal reforming (DIR) reaction of methane, the water-gas shift (WGS) reaction and the electrochemical reaction of hydrogen are the three reactions taken into account in this simulation work. Detailed comparisons of the gas concentrations and temperature change profiles among these three simulation models are presented and discussed. Thermo-dynamic predictions of both nickel oxidation and carbon deposition are also employed to check the operation safety of SOFCs fueled with different gases

Применение генетического алгоритма в задачах адаптации структур данных

Представлена разработанная схема адаптации структур данных в оперативной памяти. Для поиска адаптированной структуры данных предложено применение генетического алгоритма. Определены его особенности. Для растровых изображений с соответствующими заголовками выполнены экспериментальные исследования временной эффективности адаптированных структур данных, времени сходимости генетического алгоритма и условия целесообразности применения адаптации.Представлена розроблена схема адаптації структур даних в оперативній пам’яті. Для пошуку адаптованої структури даних запропоновано застосування генетичного алгоритму. Визначені його особливості. Для растрових зображень з відповідними заголовками виконані експериментальні дослідження часової ефективності адаптованих структур даних, часу збіжності генетичного алгоритму та умови доцільності застосування адаптації.The developed scheme of data structures adaptation in memory is given. To search for an adapted data structure, genetic algorithm is proposed and its characteristics are defined. For raster images with the appropriate headings, experimental studies of the time efficiency of adapted data structures, the convergence time of the genetic algorithm and conditions for feasibility of adapting are performed

Diagnostic accuracy for different strategies of image-guided breast intervention in cases of nonpalpable breast lesions

To find out whether ultrasound-guided fine-needle aspiration (FNA) and ultrasound and stereotactic-guided large core needle biopsy (LCNB) are reliable alternatives to needle-localised open breast biopsy (NLBB) in daily practice, we performed a retrospective study and evaluated the validity of these methods. In all, 718 women with 749 nonpalpable breast lesions from three Dutch Hospitals were included, and the validity of the various methods for diagnosis was assessed. This was carried out according to a method described by Burbank and Parker for evaluating the quality of an image-guided breast intervention. We compared our results with the outcome of the COBRA study. Overall, all diagnostic strategies (NLBB, FNA, LCNB ultrasound and stereotactic guided) show comparable agreement rates. However, the miss rates differ: 2% for NLBB, 3% for COBRA (LCNB in study setting), 5% for FNA and 8-12% for LCNB in practice. Fine-needle aspiration was nonconclusive in 29%, and shows an overestimation for DCIS in 9%. The DCIS underestimate rate in NLBB was 8%. For the assessment of lesions consisting of microcalcifications only and to exclude malignancy in all other lesions, a 14-gauge needle should be used. Ultrasound-guided intervention can be performed in a large percentage of nonpalpable lesions. Lesions consisting only of microcalcifications on mammography need special attention

Increasing thyroid cancer incidence in Lithuania in 1978–2003

BACKGROUND: The aim of this paper is to analyze changes in thyroid cancer incidence trends in Lithuania during the period 1978–2003 using joinpoint regression models, with special attention to the period 1993–2003. METHODS: The study was based on all cases of thyroid cancer reported to the Lithuanian Cancer Registry between 1978 and 2003. Age group-specific rates and standardized rates were calculated for each gender, using the direct method (world standard population). The joinpoint regression model was used to provide estimated annual percentage change and to detect points in time where significant changes in the trends occur. RESULTS: During the study period the age-standardized incidence rates increased in males from 0.7 to 2.5 cases per 100 000 and in females from 1.5 to 11.4 per 100 000. Annual percentage changes during this period in the age-standardized rates were 4.6% and 7.1% for males and females, respectively. Joinpoint analysis showed two time periods with joinpoint in the year 2000. A change in the trend occurred in which a significant increase changed to a dramatic increase in thyroid cancer incidence rates. Papillary carcinoma and stage I thyroid cancer increases over this period were mainly responsible for the pattern of changes in trend in recent years. CONCLUSION: A moderate increase in thyroid cancer incidence has been observed in Lithuania between the years 1978 and 2000. An accelerated increase in thyroid cancer incidence rates took place in the period 2000–2003. It seems that the increase in thyroid cancer incidence can be attributed mainly to the changes in the management of non palpable thyroid nodules with growing applications of ultrasound-guided fine needle aspiration biopsy in clinical practice

Randomised trials conducted using cohorts : a scoping review

Acknowledgements We thank Margaret Sampson, MLIS, PhD, AHIP (Children’s Hospital of Eastern Ontario, Ottawa, Canada) for developing the search strategies on behalf of the CONSORT team. We thank Dr Philippa Fibert, St Mary’s University, Twickenham, London for her help in screening publications for inclusion.Peer reviewe

Time to Surgical Treatment for Metastatic Spinal Disease: Identification of Delay Intervals

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Minimizing delays in referral, diagnosis and treatment of patients with symptomatic spinal metastases is important for optimal treatment outcomes. The primary objective of this study was to investigate several forms of delay from the onset of symptoms until surgical treatment of spinal metastases for patients with and without a known preexisting known malignancy. METHODS: All patients receiving surgical treatment for spinal metastases in a single tertiary spine center were identified. Referral patterns were reconstructed and the total delay was divided into 4 categories: patient delay (onset of symptoms until medical consultation), diagnostic delay (medical consultation until diagnosis), referral delay (diagnosis until referral to spine surgeon) and treatment delay (referral spine to surgeon until treatment). These intervals were compared between patients with and without a known preexisting malignancy. RESULTS: The median total delay was 99 days, patient delay 19 days, diagnostic delay 21,5 days, referral delay 7 days, treatment delay 8 days and diagnosis and treatment delay combined 18,5 days. No difference in total delay was observed between patients with and without a known preexisting malignancy. Total delay was not significantly associated with patient age, sex, oncological history, tumor prognosis and spinal level of the tumor. CONCLUSIONS: Patients with symptomatic spinal metastases experience considerable delays, even after metastatic spinal disease has been diagnosed, regardless of a preexisting malignancy. By identifying and eliminating the causes of these delays, diagnosis, referral and treatment may be expedited leading to improved patient outcome

Stereotactic large-core needle breast biopsy: analysis of pain and discomfort related to the biopsy procedure

The purpose of this study was to determine the significance of variables such as duration of the procedure, type of breast tissue, number of passes, depth of the biopsies, underlying pathology, the operator performing the procedure, and their effect on women’s perception of pain and discomfort during stereotactic large-core needle breast biopsy. One hundred and fifty consecutive patients with a non-palpable suspicious mammographic lesions were included. Between three and nine 14-gauge breast passes were taken using a prone stereotactic table. Following the biopsy procedure, patients were asked to complete a questionnaire. There was no discomfort in lying on the prone table. There is no relation between type of breast lesion and pain, underlying pathology and pain and performing operator and pain. The type of breast tissue is correlated with pain experienced from biopsy (P = 0.0001). We found out that patients with dense breast tissue complain of more pain from biopsy than patients with more involution of breast tissue. The depth of the biopsy correlates with pain from biopsy (P = 0.0028). Deep lesions are more painful than superficial ones. There is a correlation between the number of passes and pain in the neck (P = 0.0188) and shoulder (P = 0.0366). The duration of the procedure is correlated with pain experienced in the neck (P = 0.0116) but not with pain experienced from biopsy

Translation of IDEA trial results into clinical practice: Analysis of the implementation of a new guideline for colon cancer

The IDEA trial showed no clinical relevant differences in efficacy between 3 and 6 months of oxaliplatin-based adjuvant chemotherapy (ACT) in colon cancer (CC), while toxicity was substantially lower in the 3 months regimen. Therefore, in 2017 the Dutch colorectal cancer guideline was revised and currently recommends 3 months of oxaliplatin-based ACT. Furthermore, the definition of high-risk stage II CC was restricted to pT4 tumors. We analyzed changes in ACT between 2015 and 2019. From the Netherlands Cancer Registry all 16 721 patients ≥18 years with resected high-risk stage II and stage III CC during 2015 to 2019 were selected. Differences in patient and treatment characteristics were analyzed per calendar year according to stage and age. Mean duration of oxaliplatin-based ACT decreased from 18.6 (±8.0) to 9.5 (±3.8) weeks between 2015 and 2019. In patients receiving ACT (n = 8170), the proportion treated with oxaliplatin increased from 74% to 83%. The proportion of patients receiving ACT was stable, 61% to 69% in stage III and 26% to 29% in pT4 stage II. ACT in previous high-risk pT3N0 disease decreased from 15% to 3%. Use of oxaliplatin increased from 27% to 49% in patients aged ≥75 years. The revised guideline was rapidly implemented and led to an increase in oxaliplatin-based ACT in the elderly and increased guideline-adherence in high-risk stage II CC

Cost-effectiveness of stereotactic large-core needle biopsy for nonpalpable breast lesions compared to open-breast biopsy

This paper demonstrates that the introduction of large-core needle biopsy (LCNB) replacing needle-localised breast biopsy (NLBB) for nonpalpable (screen-detected) breast lesions could result in substantial cost savings at the expense of a possible slight increase in breast cancer mortality. The cost-effectiveness of LCNB and NLBB was estimated using a microsimulation model. The sensitivity of LCNB (0.97) and resource use and costs of LCNB and NLBB were derived from a multicentre consecutive cohort study among 973 women who consented in getting LCNB and NLBB, if LCNB was negative. Sensitivity analyses were performed. Replacing NLBB with LCNB would result in approximately six more breast cancer deaths per year (in a target population of 2.1 million women), or in 1000 extra life-years lost from breast cancer (effect over 100 years). The total costs of management of breast cancer (3% discounted) are estimated at £4676 million with NLBB; introducing LCNB would save £13 million. The incremental cost-effectiveness ratio of continued NLBB vs LCNB would be £12 482 per additional life-year gained (3% discounted); incremental costs range from £-21 687 (low threshold for breast biopsy) to £74 378 (high sensitivity of LCNB)