Investigation on electricity market designs enabling demand response and wind generation

Demand Response (DR) comprises some reactions taken by the end-use customers to decrease or shift the electricity consumption in response to a change in the price of electricity or a specified incentive payment over time. Wind energy is one of the renewable energies which has been increasingly used throughout the world. The intermittency and volatility of renewable energies, wind energy in particular, pose several challenges to Independent System Operators (ISOs), paving the way to an increasing interest on Demand Response Programs (DRPs) to cope with those challenges. Hence, this thesis addresses various electricity market designs enabling DR and Renewable Energy Systems (RESs) simultaneously. Various types of DRPs are developed in this thesis in a market environment, including Incentive-Based DR Programs (IBDRPs), Time-Based Rate DR Programs (TBRDRPs) and combinational DR programs on wind power integration. The uncertainties of wind power generation are considered through a two-stage Stochastic Programming (SP) model. DRPs are prioritized according to the ISO’s economic, technical, and environmental needs by means of the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. The impacts of DRPs on price elasticity and customer benefit function are addressed, including the sensitivities of both DR parameters and wind power scenarios. Finally, a two-stage stochastic model is applied to solve the problem in a mixed-integer linear programming (MILP) approach. The proposed model is applied to a modified IEEE test system to demonstrate the effect of DR in the reduction of operation cost.A Resposta Dinâmica dos Consumidores (DR) compreende algumas reações tomadas por estes para reduzir ou adiar o consumo de eletricidade, em resposta a uma mudança no preço da eletricidade, ou a um pagamento/incentivo específico. A energia eólica é uma das energias renováveis que tem sido cada vez mais utilizada em todo o mundo. A intermitência e a volatilidade das energias renováveis, em particular da energia eólica, acarretam vários desafios para os Operadores de Sistema (ISOs), abrindo caminho para um interesse crescente nos Programas de Resposta Dinâmica dos Consumidores (DRPs) para lidar com esses desafios. Assim, esta tese aborda os mercados de eletricidade com DR e sistemas de energia renovável (RES) simultaneamente. Vários tipos de DRPs são desenvolvidos nesta tese em ambiente de mercado, incluindo Programas de DR baseados em incentivos (IBDRPs), taxas baseadas no tempo (TBRDRPs) e programas combinados (TBRDRPs) na integração de energia eólica. As incertezas associadas à geração eólica são consideradas através de um modelo de programação estocástica (SP) de dois estágios. Os DRPs são priorizados de acordo com as necessidades económicas, técnicas e ambientais do ISO por meio da técnica para ordem de preferência por similaridade com a solução ideal (TOPSIS). Os impactes dos DRPs na elasticidade do preço e na função de benefício ao cliente são abordados, incluindo as sensibilidades dos parâmetros de DR e dos cenários de potência eólica. Finalmente, um modelo estocástico de dois estágios é aplicado para resolver o problema numa abordagem de programação linear inteira mista (MILP). O modelo proposto é testado num sistema IEEE modificado para demonstrar o efeito da DR na redução do custo de operação

Effect of ghrelin administration on postoperative inflammatory response and bodyweight loss in patients with oesophageal cancer undergoing oesophagectomy: a systematic review and meta-analysis

Objectives To investigate the effect of postoperative ghrelin therapy on postoperative inflammatory response and bodyweight loss in patients undergoing an oesophagectomy for oesophageal cancer. Methods We conducted a systematic search using electronic information databases in accordance to PRISMA standards to identify studies comparing outcomes after oesophagectomy in patients who were and were not administered ghrelin in the postoperative period. Meta-analysis of the outcomes using random effects modelling was conducted. The Cochrane collaboration’s tool and ROBINS-I tool were used for risk of bias assessment of the included studies. Results Five studies including 192 patients were selected for analysis. Ghrelin therapy was associated with a significantly shorter duration of systemic inflammatory response syndrome (SIRS) (MD: − 2.72, P = 0.0001), lower CRP level on postoperative day 3 (MD: − 3.64, P < 0.0001), and less total bodyweight loss (MD: − 1.87, P = 0.14). There was no differences between the two groups in IL-6 level on postoperative day 3 (MD: − 19.65, P = 0.32), total lean body weight loss (MD: − 1.87, P = 0.14), total body fat loss (MD: 0.15, P = 0.84), pulmonary complications (OR: 0.47, P = 0.12), anastomotic leak (OR: 1.17, P = 0.78), wound complications (OR: 1.64, P = 0.63), postoperative bleeding (OR: 0.32, P = 0.33), arrhythmia (OR: 1.22, P = 0.77). Conclusions Administration of ghrelin following oesophagoectomy may reduce duration of postoperative SIRS and bodyweight loss. Whether shorter duration of SIRS and less bodyweight loss resulted from postoperative ghrelin therapy can translate into improved morbidity or mortality outcomes remains unknown. There is a need for randomised controlled trials with robust statistical power to investigate the role of postoperative ghrelin therapy on morbidity and mortality outcomes in patients undergoing oesophagectomy

Security-constrained unit commitment with natural gas pipeline transient constraints

The interdependencies of power systems and natural gas networks have increased due to the additional installations of more environmental-friendly and fast-ramping natural gas power plants. The natural gas transmission network constraints and the use of natural gas for other types of loads can affect the delivery of natural gas to generation units. These interdependencies will affect the power system security and economics in day-ahead and real-time operations. Hence, it is imperative to analyze the impact of natural gas network constraints on the security-constrained unit commitment (SCUC) problem. In particular, it is important to include natural gas and electricity network transients in the integrated system security because the impacts of any disturbances propagate at two distinctly different speeds in natural gas and electricity networks. Thus, analyzing the transient behavior of the natural gas network on the security of natural gas power plants would be essential as these plants are considered to be very flexible in electricity networks. This paper presents a method for solving the SCUC problem considering the transient behavior of the natural gas transmission network. The applicability of the presented method and the accuracy of the proposed solution are demonstrated for the IEEE 118-bus power system, which is linked with the natural gas transmission system and the results are discussed in this paper.fi=vertaisarvioitu|en=peerReviewed

Laparoscopic peritoneal lavage versus sigmoidectomy for management of perforated diverticulitis: meta-analysis of Randomized Controlled Trials

Introduction: Controversy exists regarding the role of laparoscopic peritoneal lavage in patients with perforated diverticulitis. Our objective was to conduct the first meta-analysis of Randomized Controlled Trials (RCT's) to compare the outcomes of patient undergoing laparoscopic peritoneal lavage with sigmoidectomy in patients with perforated diverticulitis. Methods: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards, we conducted a systematic search of electronic information sources, including MEDLINE; EMBASE; CINAHL; CENTRAL; The World Health Organization International Clinical Trials Registry; ClinicalTrials.gov; ISRCTN Register and bibliographic reference lists. We applied a combination of free text and controlled vocabulary search adapted to thesaurus headings, search operators and limits in each of the above databases. Overall morbidity, mortality, and postoperative complications were defined as the primary outcome parameters. Procedure time and length of hospital stay were secondary outcomes. The combined overall effect sizes were calculated using fixed-effect or random-effects models. Results: We identified 4 RCT's comparing outcomes of laparoscopic peritoneal lavage and open sigmoidectomy for perforated diverticulitis. All studies included only Hinchey grade III diverticulitis. The subsequent analysis, including 390 patients, demonstrated that laparoscopic peritoneal lavage of perforated diverticulitis was associated with significantly increased rates of overall morbidity (OR: 1.30, 95% CI 1.07-1.57, p = 0.007) and intra-abdominal abscess (OR: 3.10, 95% CI 1.71-5.63, p = 0.0002) compared to sigmoidectomy. However, there was no significant difference in mortality (OR: 0.86, 95% CI 0.42-1.77, p = 0.69) and re-operation (OR: 1.20, 95% CI 0.36-4.02, p = 0.77) rates between the two groups. Between-study heterogeneity was non-significant in all analyses, except reoperation rate (I2 = 79%, p = 0.002). The available data did not allow an appropriate analysis of procedure time, length of hospital stay and other postoperative complications. Conclusion: Our analysis of randomised trials demonstrated that laparoscopic peritoneal lavage of perforated diverticulitis may lead to more adverse events than open sigmoid resection. Future high quality RCT's are indeed required to provide stronger evidence as no definitive conclusion can be drawn considering the limited number of available RCT's

Folic acid supplementation increases survival and modulates high risk HPV-induced phenotypes in oral squamous cell carcinoma cells and correlates with p53 mRNA transcriptional down-regulation

<p>Abstract</p> <p>Background</p> <p>Although the primary risk factors for developing oral cancers are well understood, less is known about the relationship among the secondary factors that may modulate the progression of oral cancers, such as high-risk human papillomavirus (HPV) infection and folic acid (FA) supplementation. This study examined high-risk HPV and FA supplementation effects, both singly and in combination, to modulate the proliferative phenotypes of the oral cancer cell lines CAL27, SCC25 and SCC15.</p> <p>Results</p> <p>Using a comprehensive series of integrated <it>in vitro </it>assays, distinct effects of HPV infection and FA supplementation were observed. Both high-risk HPV strains 16 and 18 induced robust growth-stimulating effects in CAL27 and normal HGF-1 cells, although strain-specific responses were observed in SCC25 and SCC15 cells. Differential effects were also observed with FA administration, which significantly altered the growth rate of the oral cancer cell lines CAL27, SCC15, and SCC25, but not HGF-1 cells. Unlike HPV, FA administration induced broad, general increases in cell viability among all cell lines that were associated with <it>p53 </it>mRNA transcriptional down-regulation. None of these cell lines were found to harbor the common C677T mutation in methylenetetrahydrofolate reductase (<it>MTHFR</it>), which can reduce FA availability and may increase oral cancer risk.</p> <p>Conclusion</p> <p>Increased FA utilization and DNA hypermethylation are common features of oral cancers, and in these cell lines, specifically. The results of this study provide further evidence that FA antimetabolites, such as Fluorouracil (f5U or 5-FU) and Raltitrexed, may be alternative therapies for tumors resistant to other therapies. Moreover, since the incidence of oral HPV infection has been increasing, and can influence oral cancer growth, the relationship between FA bioavailability and concomitant HPV infection must be elucidated. This study is among the first pre-clinical studies to evaluate FA- and HPV-induced effects in oral cancers, both separately and in combination, which provides additional rationale for clinical screening of HPV infection prior to treatment.</p

Electrical stimulation devices for the prevention of venous thromboembolism: Preliminary studies of physiological efficacy and user satisfaction.

Introduction: Electrical stimulation could provide an alternative method for preventing venous thromboembolism in stroke patients. The purpose of this preliminary study was to explore the effects of electrical stimulation and intermittent pneumatic compression on enhancing lower limb venous return in healthy and chronic stroke patients and also to evaluate patient and nurse satisfaction. Methods: We investigated the effectiveness of two electrical stimulation devices: Geko (Firstkind Ltd, High Wycombe, UK) and Orthopaedic Microstim 2V2 (Odstock Medical Ltd, Salisbury, UK); and one intermittent pneumatic compression device: Huntleigh Flowstron Universal (Huntleigh Healthcare Ltd, Cardiff, UK). We recruited 12 healthy and 5 chronic stroke participants. The devices were fitted sequentially, and Doppler ultrasound measurements were taken. Eight patients and nurses were also recruited for a separate usability evaluation. Results: The electrical stimulation devices emulated the blood flow characteristics of intermittent pneumatic compression in both healthy and stroke participants provided that the intensity of electrical stimulation was sufficient. Patients and nurses also felt that the electrical stimulation devices were acceptable. Conclusions: Electrical stimulation may offer benefit as an alternative method for venous thromboembolism prevention in stroke patients. The apparent benefit is sufficient to warrant further investigation in a full powered randomised controlled trial

European association for endoscopic surgery (EAES) consensus statement on single-incision endoscopic surgery

Laparoscopic surgery changed the management of numerous surgical conditions. It was associated with many advantages over open surgery, such as decreased postoperative pain, faster recovery, shorter hospital stay and excellent cosmesis. Since two decades single-incision endoscopic surgery (SIES) was introduced to the surgical community. SIES could possibly result in even better postoperative outcomes than multi-port laparoscopic surgery, especially concerning cosmetic outcomes and pain. However, the single-incision surgical procedure is associated with quite some challenges.This article is freely available via Open Access, click on the Publisher's URL to access the full-text.Publishe

Anaesth Crit Care Pain Med

Objective To develop French guidelines on the management of patients with severe abdominal trauma. Design A consensus committee of 20 experts from the French Society of Anaesthesiology and Critical Care Medicine (Société française d’anesthésie et de réanimation, SFAR), the French Society of Emergency Medicine (Société française de médecine d’urgence, SFMU), the French Society of Urology (Société française d’urologie, SFU) and from the French Association of Surgery (Association française de chirurgie, AFC), the Val-de-Grâce School (École du Val-De-Grâce, EVG) and the Federation for Interventional Radiology (Fédération de radiologie interventionnelle, FRI-SFR) was convened. Declaration of all conflicts of interest (COI) policy by all participants was mandatory throughout the development of the guidelines. The entire guideline process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system for assessment of the available level of evidence with particular emphasis to avoid formulating strong recommendations in the absence of high level. Some recommendations were left ungraded. Methods The guidelines are divided in diagnostic and, therapeutic strategy and early surveillance. All questions were formulated according to Population, Intervention, Comparison, and Outcomes (PICO) format. The panel focused on three questions for diagnostic strategy: (1) What is the diagnostic performance of clinical signs to suggest abdominal injury in trauma patients? (2) Suspecting abdominal trauma, what is the diagnostic performance of prehospital FAST (Focused Abdominal Sonography for Trauma) to rule in abdominal injury and guide the prehospital triage of the patient? and (3) When suspecting abdominal trauma, does carrying out a contrast enhanced thoraco-abdominal CT scan allow identification of abdominal injuries and reduction of mortality? Four questions dealt with therapeutic strategy: (1) After severe abdominal trauma, does immediate laparotomy reduce morbidity and mortality? (2) Does a “damage control surgery” strategy decrease morbidity and mortality in patients with a severe abdominal trauma? (3) Does a laparoscopic approach in patients with abdominal trauma decrease mortality or morbidity? and (4) Does non-operative management of patients with abdominal trauma without bleeding reduce mortality and morbidity? Finally, one question was formulated regarding the early monitoring of these patients: In case of severe abdominal trauma, which kind of initial monitoring does allow to reduce the morbi-mortality? The analysis of the literature and the recommendations were conducted following the GRADE® methodology. Results The SFAR/SFMU Guideline panel provided 15 statements on early management of severe abdominal trauma. After three rounds of discussion and various amendments, a strong agreement was reached for 100% of recommendations. Of these recommendations, five have a high level of evidence (Grade 1±), six have a low level of evidence (Grade 2±) and four are expert judgments. Finally, no recommendation was provided for one question. Conclusions Substantial agreement exists among experts regarding many strong recommendations for the best early management of severe abdominal trauma