bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Parzen Window estimation for incipient fault diagnosis in power transformers
Authors: Islam Md Mominul , Lee Gareth , Hettiwatte Sujeewa Nilendra
Published: August 2018

Accurate faults diagnosis in power transformers is important for utilities to schedule maintenance and minimises the operation cost. Dissolved gas analysis (DGA) is one of the proven and widely accepted tools for incipient fault diagnosis in power transformers. To improve the accuracy and solve the cases that cannot be classified using Rogers’ Ratios, IEC ratios and Duval triangles methods, a novel DGA technique based on Parzen window estimation have been presented in this study. The model uses the concentrations of five combustible hydrocarbon gases: methane, ethane, ethylene, acetylene and hydrogen to compute the probability of transformers fault categories. Performance of the proposed method has been evaluated against different conventional techniques and artificial intelligence‐based approaches such as support vector machines, artificial neural networks, rough sets analysis and extreme learning machines for the same set of transformers. A comparison with other soft computing approaches shows that the proposed method is reliable and effective for incipient fault diagnosis in power transformers.
Approximation for the ML detector in decode and forward relay networks and the effect of channel estimation error
Authors: Neinavaie Mohammad , Zolghadrasli Ali Reza , Derakhtian Mostafa
Published: August 2018

The cooperative maximum ratio combiner (C‐MRC) is able to collect the maximum available diversity in decode and forward (DF) relay networks, and is simple to be implemented relative to the maximum likelihood (ML) detector. In this study, the authors provide some approximations for the ML detector, and they prove that the well‐known C‐MRC detector which was considered to be an intuitive method is, indeed, a linear approximation for the ML detector in DF relay networks. They also study the performance of the approximated ML detector in the presence of channel estimation error. This study determines the sensitivity of the diversity gain achieved by the approximated ML detector to the channel estimation error. Simulation results are also presented to corroborate the derived analytical results.
Battery and backup generator sizing for a resilient microgrid under stochastic extreme events
Authors: Dong Jiaojiao , Zhu Lin , Su Yu , Ma Yiwei , Liu Yilu , Wang Fred , Tolbert Leon M. , Glass Jim , Bruce Lilian
Published: August 2018

Owing to the recent power outages caused by extreme events, installing battery energy storage and backup generators is important to improve resiliency for a grid‐tied microgrid. In the design stage, the event occurrence time and duration, which are highly uncertain and cannot be effectively predicted, may affect the needed battery and backup generator capacity but are usually assumed to be pre‐determined in utility planning tools. This study investigates the optimal battery and backup generator sizing problem considering the stochastic event occurrence time and duration for the grid‐tied microgrid under islanded operation. The reliability requirement is quantified by the mean value of the critical customer interruption time in each stochastic islanding time window (ITW), whose length is the duration and the centre is the occurrence time. The stochastic ITW constraint is then transformed to a probability‐weighted expression to derive an equivalent Mixed Integer Linear Programming model. Numerical simulations on a realistic grid‐tied PV‐based microgrid demonstrate that the total cost is reduced by 11.5% considering the stochastic ITW, compared with the deterministic ITW under the same reliability requirement.
Modified mean shift algorithm
Authors: Aliyari Ghassabeh Youness , Rudzicz Frank
Published: August 2018

The mean shift (MS) algorithm is an iterative method introduced for locating modes of a probability density function. Although the MS algorithm has been widely used in many applications, the convergence of the algorithm has not yet been proven. In this study, the authors modify the MS algorithm in order to guarantee its convergence. The authors prove that the generated sequence using the proposed modified algorithm is a convergent sequence and the density estimate values along the generated sequence are monotonically increasing and convergent. In contrast to the MS algorithm, the proposed modified version does not require setting a stopping criterion a priori; instead, it guarantees the convergence after a finite number of iterations. The proposed modified version defines an upper bound for the number of iterations which is missing in the MS algorithm. The authors also present the matrix form of the proposed algorithm and show that, in contrast to the MS algorithm, the weight matrix is required to be computed once in the first iteration. The performance of the proposed modified version is compared with the MS algorithm and it was shown through the simulations that the proposed version can be used successfully to estimate cluster centres.
Three‐dimensional imaging of an object behind an anisotropic wall
Authors: Jafarpourjalali Mohammad , Tavakoli Ahad , Dehkhoda Parisa
Published: August 2018

Based on the well‐known diffraction tomography (DT) method, a three‐dimensional (3D) inverse scattering algorithm is proposed to identify a hidden object behind an anisotropic wall. The spatial spectral expansion of the dyadic Green's function of the multi‐layered structure with anisotropic material is employed in the DT formulation of the scattered field. Born approximation is utilised for weak scatterers that model the scattered field as a linear function of the object function. The proposed method is very efficient and suitable for real‐time applications due to its easy and fast implementation.
Mercurius solubilis Hahnemanni bei Kälberdurchfall
Authors: Hentschel Brigitte , Hornig Bernhard
Published: August 2018

Durchfallerkrankungen sind nach wie vor die häufigste Todesursache neugeborener Kälber. Trotz Optimierung der äußeren Umstände, kommt es unter Praxisbedingungen noch immer zu massiven Ausbrüchen mit hohen Tierverlusten. Hier stößt die Schulmedizin nur allzu oft an ihre Grenzen. Obwohl sehr viele homöopathische Arzneien bei Kälberdurchfall infrage kommen, sticht Mercurius solubilis Hahnemanni aus der Masse hervor. Durch die Darstellung offensichtlicher Parallelen zwischen dem Arzneimittelbild von Mercurius und der Pathophysiologie von Kälberdurchfall, wird sein Nutzen bei dieser Krankheit deutlich gemacht und mittels zwei anschaulichen Fallbeispielen aus der Praxis belegt.
„Da kann man sich ja totklingeln, geht ja keiner ran“ – Schnittstellenprobleme zwischen stationärer, hausärztlicher und ambulant-fachspezialisierter Patientenversorgung aus Sicht Dresdner Hausärzte
Authors: Lang Caroline , Gottschall Mandy , Sauer Maik , Köberlein-Neu Juliane , Bergmann Antje , Voigt Karen
Published: August 2018

Ziel der Studie Ziel der Studie war es, Schnittstellenprobleme zwischen stationärer, hausärztlicher und ambulant-fachspezialisierter Patientenversorgung bei älteren multimorbiden Patienten aus hausärztlicher Sicht aufzudecken.

Methodik Die Datenerhebung erfolgte im Rahmen der Pilotstudie „Multimedikation und ihre Folgen für die hausärztliche Patientenversorgung in Sachsen“ und umfasste leitfadengestützte Interviews mit 7 Hausärzten. Die Interviews wurden vollständig transkribiert und inhaltlich in Anlehnung an die induktive Kategorienentwicklung nach Mayring analysiert.

Ergebnisse An stationärer zu ambulant-hausärztlichen Schnittstelle zeigten sich v. a. Probleme bei der intersektoralen Kommunikation und Kooperation, dem Entlassmanagement sowie beim Medikationsmanagement. An der Schnittstelle vom Hausarzt zu ambulant-fachspezialisierten Kollegen zeigten sich Probleme hinsichtlich der freien Arztwahl, des Terminmanagements, des ärztlichen Entscheidungsfindungsprozesses, des Medikationsmanagements sowie bei der Nutzung der elektronischen Gesundheitskarte. Schnittstellenunabhängig wurden die mangelnde Kommunikation und Kooperation als zentrale Herausforderungen herausgearbeitet.

Schlussfolgerung Aus hausärztlicher Sicht gibt es eine Vielzahl von Problemen zu allen angrenzenden Schnittstellen. Auffällig hierbei ist die mangelnde Kommunikation und Kooperation zwischen den verschiedenen Beteiligten. Als mögliche Ursachen zeigen sich die häufig sehr unterschiedlichen Arbeitsweisen und Rahmenbedingungen, personellen und materiellen Ressourcen sowie Therapieintentionen und -ansätze zwischen den settingspezifischen Schnittstellen. Ein möglicher Ansatz zur Verbesserung der Situation kann das seit 2016 bestehende Gesetz für sichere digitale Kommunikation und Anwendungen im Gesundheitswesen sein. Es verspricht u. a. einen sicheren und zügigen inter- und intrasektoralen Informationsaustausch von Patientendaten. Übergeordnetes Ziel der Gesundheitsversorgung in Deutschland sollte ein optimiertes und prozessorientiertes Schnittstellenmanagement sein, um Patienten einen sicheren und nahtlosen sektoralen Übergang zu gewährleisten.
Synthesis of Functionalized 5-Amino-3(2H)-furanones via Base-Catalyzed Ring-Cleavage/Recyclization of 4-Cyano-3(2H)-furanones in the Presence of Water
Authors: Shemyakina Olesya , Volostnykh Olga , Stepanov Anton , Ushakov Igor , Borodina Tatyana
Published: August 2018

5-Alkyl/aryl/hetaryl-4-cyano-3(2H)-furanones undergo ring-cleavage/recyclization in the presence of water under mild conditions [MOH (M = Na, K), aqueous ethanol, 20–25 °C] to afford 4-acyl/aroyl/hetaroyl-5-amino-3(2Н)-furanones in 75–99% yields.
Interrupted Ugi and Passerini Reactions: An Underexplored Treasure Island
Authors: Giustiniano Mariateresa , Moni Lisa , Tron Gian , Sangaletti Luca , Pelliccia Sveva , Basso Andrea , Novellino Ettore
Published: August 2018

The formation of the key short-lived intermediate nitrilium ion in the Passerini and Ugi reactions was recognized early in the discovery of these two-multicomponent transformations. Surprisingly, the idea of intramolecularly intercepting it, eluding the attack by the carboxylate, and thus interrupting the normal course of the reaction, was missed by chemists for several decades. In this review we describe, in an exhaustive manner, the reported synthetic approaches, which can be categorized as interrupted Passerini/Ugi reactions. Besides, the clear goal of this review is to show the potential of these transformations, whilst highlighting the underexplored combinations of reagents toward the identification of novel interrupted Passerini/Ugi reactions.

1 Introduction

2 The Interrupted Ugi Reaction

2.1 The Interrupting Functional Group is Present on the Amine Reactant

2.2 The Interrupting Functional Group is Present on the Isocyanide Reactant

2.3 The Interrupting Functional Group is Present on the Carbonyl Reactant

3 The Interrupted Passerini Reaction

3.1 The Interrupting Functional Group is Present on the Carbonyl Reactant

3.2 The Interrupting Functional Group is Present on the Isocyanide Reactant

4 Conclusions and Future Outlook
Recent Advances in the Synthesis of Hetero- and Carbocyclic Compounds­ and Complexes Based on Acenaphthylene-1,2-dione
Authors: Yavari Issa , Khajeh-Khezri Aliyeh
Published: August 2018

Acenaphthylene-1,2-dione has been utilized in a wide range of reactions as a starting material for the synthesis of hetero- and carbocyclic compounds and complexes. This review provides a short summary of the recent advances in the application of acenaphthylene-1,2-dione in the synthesis of hetero- and carbocyclic systems and bioactive compounds. In addition, the applications of acenaphthylene-1,2-dione in the synthesis of spiro compounds, propellanes, and ligands in catalyst reactions, from 2002 to early 2018, are included.

1 Introduction

2 Synthesis of Spiro Compounds Employing Acenaphthylene-1,2-dione

2.1 Methods for the Construction of Spiro Compounds

2.1.1 By 1,3-Dipolar Cycloaddition of Acenaphthylene-1,2-dione via Azomethine Ylides

2.1.2 By Multicomponent Reactions of Acenaphthylene-1,2-dione with C–H Acidic Compounds

2.1.3 By Reaction of Acenaphthylene-1,2-dione with Zwitterionic Intermediates

2.1.4 By Substitution and Multicomponent Reactions of Acenaphth- ylene-1,2-dione with Different Nucleophiles

3 Synthesis of Propellanes by Employing Acenaphthylene-1,2-dione

3.1 Methods for the Construction of Propellanes Based on Acenaph- thylene-1,2-dione

3.1.1 By Reaction of Acenaphthylene-1,2-dione with Nucleophiles

3.1.2 By Reaction of Acenaphthylene-1,2-dione with Binucleophiles

4 Synthesis of Ligands Employing Acenaphthylene-1,2-dione for Catalyst Reactions

5 Synthesis of Novel Hetero- and Carbocyclic Compounds Employing Acenaphthylene-1,2-dione

5.1 By Reaction of Acenaphthylene-1,2-dione with Nucleophiles

5.2 By Reaction of Acenaphthylene-1,2-dione with Zwitterionic Intermediates

5.3 By Ring Opening and Ring Enlargement

6 Conclusion
One-Pot Telescoped Synthesis of Thiazole Derivatives from β-Keto Esters and Thioureas Promoted by Tribromoisocyanuric Acid
Authors: de Mattos Marcio , de Andrade Vitor
Published: August 2018

A simple and efficient one-pot protocol has been developed for the synthesis of thiazole derivatives from readily available starting materials. Tribromoisocyanuric acid was successfully used for α-monohalogenation of β-keto esters in aqueous medium, which in the presence of thiourea and DABCO produced the corresponding 2-aminothiazoles in up to 87% yield. Extension of the reaction to thioacetamide and o-phenylenediamine led to 2-methylthiazole and quinoxalines, respectively. This approach enables telescoping of the two steps into a single process.
Hypervalent Iodine(III)-Catalyzed Synthesis of 2-Arylbenzofurans
Authors: Singh Fateh , Mangaonkar Saeesh
Published: August 2018

An alternative route for the synthesis of 2-arylbenzofurans is described by iodine(III)-catalyzed oxidative cyclization of 2-hydroxystilbenes using 10 mol% (diacetoxyiodo)benzene [PhI(OAc)2] as catalyst in the presence of m-chloroperbenzoic acid. The 2-arylbenzofurans were isolated in good to excellent yields.
HTRA2 Defect: A Recognizable Inborn Error of Metabolism with 3-Methylglutaconic Aciduria as Discriminating Feature Characterized by Neonatal Movement Disorder and Epilepsy—Report of 11 Patients
Authors: Morin Gilles , Nouri Maria , Brandau Oliver , Saadi Nebal , Nouri Mohammed , van den Broek Florence , Prokisch Holger , Mayr Johannes , Wortmann Saskia , Kovacs-Nagy Reka
Published: August 2018

Neonatal-onset movement disorders, especially in combination with seizures, are rare and often related to mitochondrial disorders. 3-methylglutaconic aciduria (3-MGA-uria) is a marker for mitochondrial dysfunction. In particular, consistently elevated urinary excretion of 3-methylglutaconic acid is the hallmark of a small but growing group of inborn errors of metabolism (IEM) due to defective phospholipid remodeling or mitochondrial membrane-associated disorders (mutations in TAZ, SERAC1, OPA3, CLPB, DNAJC19, TMEM70, TIMM50). Exome/genome sequencing is a powerful tool for the diagnosis of the clinically and genetically heterogeneous mitochondrial disorders. Here, we report 11 individuals, of whom 2 are previously unpublished, with biallelic variants in high temperature requirement protein A2 (HTRA2) encoding a mitochondria-localized serine protease. All individuals presented a recognizable phenotype with neonatal- or infantile-onset neurodegeneration and death within the first month of life. Hallmark features were central hypopnea/apnea leading to respiratory insufficiency, seizures, neutropenia, 3-MGA-uria, tonus dysregulation, and dysphagia. Tremor, jitteriness, dystonia, and/or clonus were also common. HTRA2 defect should be grouped under the IEM with 3-MGA-uria as discriminating feature. Clinical characteristics overlap with other disorders of this group suggesting a common underlying pathomechanism. Urinary organic acid analysis is a noninvasive and inexpensive test that can guide further genetic testing in children with suggestive clinical findings.
Chronic Mesenteric Ischemia: Clinical Diagnosis, Imaging Characteristics, and Endovascular Management
Authors: Dalag Leonard , Lorenz Jonathan , Tullius Thomas
Published: August 2018

Chronic mesenteric ischemia (CMI) is a complex disorder, which typically affects elderly patients who classically present with longstanding abdominal pain and nonspecific clinical symptoms, such as food aversion and weight loss. The disease progression is often gradual due to a rich collateral network, and symptoms are generally not clinically apparent until two or more primary visceral arteries are affected. Symptomatic stenosis or occlusion of the mesenteric arteries can be the result of multiple etiologies, although atherosclerosis is the most common. Given its low incidence, a high clinical suspicion is necessary for diagnosis and to prevent a delay in treatment. Multiple imaging modalities are utilized to confirm the presence of mesenteric vessel involvement and to guide treatment. While open surgical revascularization was once the definitive treatment, endovascular management has become the first-line treatment for atherosclerotic CMI. The endovascular approach with stent placement has shown excellent primary success and encouraging long-term outcomes with reduction in morbidity and mortality compared with open surgical revascularization. Although controversial, median arcuate ligament syndrome (MALS) is a less common cause of CMI, which can affect a more varied patient population. Clinical approach, imaging characteristics, and treatment for this syndrome will also be discussed.
A Systematic Review of the Technology Acceptance Model in Health Informatics
Authors: Rahimi Bahlol , Nadri Hamed , Lotfnezhad Afshar Hadi , Timpka Toomas
Published: August 2018

Background One common model utilized to understand clinical staff and patients' technology adoption is the technology acceptance model (TAM).

Objective This article reviews published research on TAM use in health information systems development and implementation with regard to application areas and model extensions after its initial introduction.

Method An electronic literature search supplemented by citation searching was conducted on February 2017 of the Web of Science, PubMed, and Scopus databases, yielding a total of 492 references. Upon eliminating duplicates and applying inclusion and exclusion criteria, 134 articles were retained. These articles were appraised and divided into three categories according to research topic: studies using the original TAM, studies using an extended TAM, and acceptance model comparisons including the TAM.

Results The review identified three main information and communication technology (ICT) application areas for the TAM in health services: telemedicine, electronic health records, and mobile applications. The original TAM was found to have been extended to fit dynamic health service environments by integration of components from theoretical frameworks such as the theory of planned behavior and unified theory of acceptance and use of technology, as well as by adding variables in specific contextual settings. These variables frequently reflected the concepts subjective norm and self-efficacy, but also compatibility, experience, training, anxiety, habit, and facilitators were considered.

Conclusion Telemedicine applications were between 1999 and 2017, the ICT application area most frequently studied using the TAM, implying that acceptance of this technology was a major challenge when exploiting ICT to develop health service organizations during this period. A majority of the reviewed articles reported extensions of the original TAM, suggesting that no optimal TAM version for use in health services has been established. Although the review results indicate a continuous progress, there are still areas that can be expanded and improved to increase the predictive performance of the TAM.
Does the Robotic Arm and Preoperative CT Planning Help with 3D Intraoperative Total Knee Arthroplasty Planning?
Authors: Marchand Robert C. , Sodhi Nipun , Bhowmik-Stoker Manoshi , Scholl Laura , Condrey Caitlin , Khlopas Anton , Sultan Assem A. , Newman Jared M. , Mont Michael A.
Published: August 2018

Although several studies highlight the advantages of robotic arm-assisted total knee arthroplasty (RA-TKA), few investigate its intraoperative outcome. Therefore, the purpose of this study was to analyze the RA-TKA's ability to assist with intraoperative correction of: (1) flexion and (2) extension gaps, as well as its ability to (3) accurately predict implant sizes. Additionally, in this RA-TKA cohort, length of stay, complications, and readmissions were assessed. A total of 335 patients who underwent RA-TKA were included. The robotic software virtually measured the intraoperative prebone cut extension and flexion gaps. Differences in medial versus lateral prebone cut extension and flexion gaps were calculated. A total of 155 patients (46%) had an extension gap difference of between –2 and 2 mm (mean, –0.3 mm), while 119 patients (36%) had a flexion gap difference of between –2 and 2 mm (mean, –0.6 mm). Postbone cut differences in medial versus lateral flexion and extension gaps were measured. Balanced knees were considered to have a medial and lateral flexion gap difference within 2 mm. The robot-predicted implant size was also compared with the final implant size. Additionally, lengths of stay, complications, and readmissions were assessed. All patients achieved a postbone cut extension gap difference between –1 and 1 mm (mean, –0.1 mm). A total of 332 patients (99%) achieved a postbone cut flexion gap difference of between –2 and 2 mm (mean, 0 mm). For 98% of prostheses, the robotic software predicted within 1 implant size the actual tibial or femoral implant size used.

The mean length of stay was found to be 2 days. No patients suffered from superficial skin infection, pin site infections or fractures, soft tissue damage, and no robotic cases were converted to manual TKA due to intraoperative complications. A total of 8 patients (2.2%) were readmitted; however, none were directly related to robotic use. The robotic software and use of a preoperative computed tomography (CT) substantially helped with intraoperative planning and accurate prediction of implant sizes. Therefore, based on the results of this study, the RA-TKA device does, in fact, provide considerable intraoperative assistance.
Anticoagulant Effects of Dabigatran in Paediatric Patients Compared with Adults: Combined Data from Three Paediatric Clinical Trials
Authors: Maas Hugo , Gropper Savion , Huang Fenglei , Stangier Joachim , Tartakovsky Igor , Brueckmann Martina , Halton Jacqueline , Mitchell Lesley
Published: August 2018

Background Physiological age-related changes in the haemostatic and coagulation systems result in differing anticoagulant assay responses to standard anticoagulants. Therefore, we investigated the response of anticoagulant assays to dabigatran etexilate (DE) in children compared with adults.

Objective This article assesses the relationship between plasma dabigatran concentration and coagulation assay results across age groups in children and adults.

Patients and Methods Data from three clinical trials in which children received DE following standard of care for venous thromboembolism were compared with data from adult clinical trials. The effects of dabigatran concentration on diluted thrombin time (dTT), ecarin clotting time (ECT) and activated partial thromboplastin time (aPTT) were analysed graphically and with modelling.

Results The concentration–dTT relationships were consistent in children across all ages and adults in the graphical analysis. For ECT and aPTT, relationships based on ratios over baseline were similar across all ages; absolute clotting times showed that the same exposure resulted in longer clotting times in some of the children aged < 1 year versus adults. Modelling showed concentration–clotting time relationships for all three assays were largely comparable between adults and children, except in those aged < 2 months, in whom there was a slight upward shift in ECT and aPTT relative to adults.

Conclusion Results suggest that developmental haemostatic changes will have little impact on response to DE. However, further paediatric clinical trials assessing the relationship between coagulation assay responses and clinical outcomes will be needed to confirm this finding.
State of Play: Eight Decades of Surgery for Esophageal Atresia
Authors: Zimmer Julia , Eaton Simon , Murchison Louise , De Coppi Paolo , Ure Benno , Dingemann Carmen
Published: August 2018

Aim Surgical expertise and advances in technical equipment and perioperative management have led to enormous progress in survival and morbidity of patients with esophageal atresia (EA) in the last decades. We aimed to analyze the available literature on surgical outcome of EA for the past 80 years.

Materials and Methods A PubMed literature search was conducted for the years 1944 to 2017 using the keywords “esophageal/oesophageal atresia,” “outcome,” “experience,” “management,” and “follow-up/follow up.” Reports on long-gap EA only, non-English articles, case reports, and reviews without original patient data were excluded. We focused on mortality and rates of recurrent fistula, leakage, and stricture.

Results Literature search identified 747 articles, 118 manuscripts met the inclusion criteria. The first open end-to-end anastomosis and fistula ligation was reported in 1941. Thoracoscopic fistula ligation and primary anastomosis was performed first in 2000. Reported mortality rate decreased from 100% before 1941 to 54% in 1950 to 1959, 28% in 1970 to 1979, 16% in 1990 to 1999, and 9% nowadays. Rates of recurrent fistula varied over time between 4 and 9%. Leakage rate remained stable between 11 and 16%. However, stricture rate increased from 25 to 38%.

Conclusion Including a full range of articles reflecting the heterogeneity of EA, mortality rate significantly decreased during the course of 80 years. Along with the decrease in mortality, there is a shift to the importance of major postoperative complications and long-term morbidity regardless of surgical technique.
Unilateral Autologous Breast Reconstruction with Bi-pedicled, Conjoined Deep Inferior Epigastric Perforator Flaps
Authors: Seth Akhil , Koolen Pieter , Sultan Steven , Lee Bernard , Erhard Heather , Greenspun David
Published: August 2018

Background The abdomen remains the most popular and reliable donor site for autologous breast reconstruction. Some patients, however, lack sufficient tissue to recreate an aesthetic breast mound using a single-pedicle, deep inferior epigastric perforator (DIEP) flap, particularly when matching a contralateral native breast. The amount of abdominal skin and/or soft tissue reliably supplied by one vascular pedicle is frequently insufficient to adequately restore the breast skin envelope and “footprint.” This study summarizes our experience with using bipedicled DIEP flaps to improve the aesthetic results of unilateral breast reconstruction in such patients.

Methods Consecutive patients undergoing unilateral breast reconstruction with bi-pedicled, conjoined DIEP flaps over a 4-year period were retrospectively reviewed. Primary and secondary flap microvascular anastomoses were performed to the antegrade internal mammary (IM) vessels and to either the retrograde IM vessels or a primary DIEP pedicle side branch, respectively. Clinical characteristics and outcomes were recorded.

Results Sixty-three patients underwent immediate (n = 29) or delayed (n = 34) reconstruction, with age and body mass index of 54.1 ± 8.4 years and 26.6 ± 4.7, respectively. Mean follow-up was 14.1 months. Twenty-eight (44.4%) patients received prereconstruction radiation therapy. All patients had preoperative abdominal imaging, including 57 (90.5%) using magnetic resonance angiography. There were no flap losses with three operative interventions for flap salvage.

Conclusion Unilateral breast reconstruction with bipedicled, conjoined DIEP flaps is safe and reliable. These procedures can be performed with a complication profile similar to single-pedicle DIEP flaps. The additional skin and soft tissue available with bi-pedicled flaps allows for greater flexibility in matching the shape and projection of a woman's contralateral breast, and in some cases is necessary to achieve an aesthetically acceptable reconstruction. With growing expectations among breast reconstruction patients, conjoined bi-pedicled flaps represent a tool for meeting their reconstructive needs and exceeding the status quo for aesthetic outcomes.
Bilateral Paravertebral Block versus Thoracic Epidural Analgesia for Pain Control Post-Cardiac Surgery: A Randomized Controlled Trial
Authors: El Shora Hatem A. , El Beleehy Ahmed A. , Abdelwahab Amr A. , Ali Gaser A. , Omran Tarek E. , Hassan Essam A. , Arafat Amr A.
Published: August 2018

Background Adequate pain control after cardiac surgery is essential. Paravertebral block is a simple technique and avoids the potential complications of epidural catheters. The objective of this study is to compare the effect of ultrasound-guided bilateral thoracic paravertebral block with thoracic epidural block on pain control after cardiac surgery.

Materials and Methods Between March 2016 and 2017, 145 patients who had cardiac surgery through median sternotomy were randomized by stratified blocked randomization into two groups. Group I (n = 70 patients) had bilateral ultrasound-guided thoracic paravertebral block and Group II (n = 75 patients) had thoracic epidural analgesia. The primary end point was the postoperative visual analogue scale (VAS). The duration of mechanical ventilation, intensive care unit (ICU), and hospital stay were the secondary end points. The study design is a randomized parallel superiority clinical trial.

Results Both groups had similar preoperative and operative characteristics. No significant difference in VAS measured immediately after endotracheal extubation then after 12, 24, and 48 hours between groups (p = 0.45). Pain score significantly declined with the repeated measures (p < 0.001) and the decline was not related to the treatment group. Postoperative pain was significantly related to diabetes mellitus (p = 0.039). Six patients in group I (8.5%) required an additional dose of morphine versus three patients (4%) in group II (p = 0.30). Patients in group I had significantly shorter ICU stay (p = 0.005) and lower incidence of urinary retention (p = 0.04) and vomiting (p = 0.018). No difference was found in operative complications between groups.

Conclusion This randomized parallel controlled trial demonstrates that ultrasound-guided paravertebral block is safe and effective method for relieving post-cardiac surgery sternotomy pain compared with thoracic epidural analgesia but not superior to it.
Minimally Invasive Redo-Aortic Valve Replacement: Reduced Operative Times as Compared to Full Sternotomy
Authors: Oezpeker Cenk , Barbieri Fabian , Zujs Vitalijs , Grimm Michael , Lio Antonio , Glauber Mattia , Bonaros Nikolaos
Published: August 2018

Objectives Increasing experience with minimally invasive cardiac (MIC) aortic valve (AV) replacement makes AV reoperations (rAVR) an appealing alternative to conventional redo surgery. The aim of the study was to compare the perioperative outcome after isolated MIC versus full-sternotomy (FS) rAVR.

Methods We retrospectively analyzed data of 116 patients from three centers who underwent rAVR by using a FS (n = 70, 60.3%) or a partial upper sternotomy approach (n = 46, 39.7%). Both groups were compared in terms of 30-day mortality by using binary-logistic regression models. Further the EuroSCORE II was used to adjust for preoperative conditions in a multivariable model. Perioperative times and complications were compared between the two groups.

Results There was no statistically significant difference in perioperative mortality between FS (n = 5, 7.1%) and MIC (n = 1, 2.2%) rAVR in the original population (odds ratio [OR] 3.462, 95% confidence interval [CI] 0.391–30,635, p = 0.264) and after adjusting for EuroSCORE II (OR 2.759, 95% CI 0.298–25.567, p = 0.372). Cardiopulmonary bypass- (115.5 minutes vs. 137.5 minutes, p = 0.070) and cross-clamp times (69.0 minutes vs. 81.0 minutes, p = 0.028) were reduced in the MIC group. There was a lower prevalence of postoperative renal failure requiring renal replacement therapy (RRT) in the MIC group 0 and 8.6% (p = 0.041), respectively. No differences were detected between the groups regarding postoperative complications.

Conclusion MIC rAVR is associated with reduced cardiopulmonary and cross-clamp times as well as the need for RRT as compared with FS. MIC-rAVR seems to be a viable option in surgical candidates for AV reoperations.
Tromboflebitis superficial del pene: primer reporte de caso en el Hospital Universitario Nacional de Colombia y recomendaciones actuales de manejo
Authors: Castañeda David , Velásquez Jonatan , Maya Daniel , Pardo Julián , Capera César , Guzmán Carlos , Donoso Wilfredo
Published: August 2018

La enfermedad de Mondor es una condición caracterizada por la presencia de tromboflebitis en varios segmentos corporales, fue descrita inicialmente por Henri Mondor en 1939 con descripciones de casos que afectaban la circulación venosa de la reja costal y las glándulas mamarias. Se alude a Braun-Falco en 1955 la primera mención de la trombosis superficial del pene, sin embargo, fue hasta 1958 cuando Helm y Hodge describieron el primer caso con compromiso urogenital masculine. Actualmente se cuenta con información limitada sobre la tromboflebitis superficial del pene (enfermedad peniana de Mondor), por lo tanto, el presente artículo describe el primer caso de tromboflebitis de la vena superficial del pene registrado en el Hospital Universitario Nacional de Colombia y expone una propuesta de abordaje terapéutico actual, basada en una revisión reciente de la literatura.
Electrical Stimulation to the Infraspinatus on Hypertrophy and Strength of the Shoulder
Authors: Yanase Ko , Hasegawa Satoshi , Nakamura Masatoshi , Yamauchi Taishi , Nishishita Satoru , Araki Kojiro , Umehara Jun , Fujita Kosuke , Sato Ikuya , Ibuki Satoko , Ichihashi Noriaki
Published: August 2018

The purpose of this study was to determine the effects of six weeks of electrical muscle stimulation (EMS) on the strength and muscle mass of the infraspinatus muscle. Twenty non-athletes (age: 24±3.4 years, height: 171.5±5.6 cm, mass: 65.2±8.1 kg) were randomly classified into two groups, an electrical muscle stimulation group (EMS group) and a control group (CON group). The EMS group completed a total of 18 20– min EMS sessions, three times per week over a period of six weeks, while the CON group received no intervention. The muscle thicknesses of both the infraspinatus and the deltoid muscles, the cross-sectional area (CSA) of the whole infraspinatus muscle, and the isometric and isokinetic peak torques of shoulder external rotations were measured before and after intervention. It was found that the muscle thickness of the superior infraspinatus (Pre 0.92±0.19 cm2, Post 0.99±0.16 cm2, p=0.02) and the CSA (Pre 10.99±1.32 cm2, Post 11.99±1.02 cm2, p=0.03) significantly increased in the EMS group. This study demonstrated that EMS of the infraspinatus muscle over a period of six weeks resulted in hypertrophy of the infraspinatus muscle.
Gyrokinetics from variational averaging: Existence and error bounds
Authors: Possanner Stefan
Published: August 2018

The gyrokinetic paradigm in the long wavelength regime is reviewed from the perspective of variational averaging (VA). The VA-method represents a third pillar for averaging kinetic equations with highly oscillatory characteristics, besides classical averaging and Hilbert expansions. VA operates on the level of the Lagrangian function and preserves the Hamiltonian structure of the characteristics at all orders. We discuss the methodology of VA in detail by means of charged-particle motion in a strong magnetic field. The application of VA to a broader class of highly oscillatory problems can be envisioned. For the charged particle, we prove the existence of a coordinate map in phase space that leads to a gyrokinetic Lagrangian at any order of the expansion, for general external fields. We compute this map up to third order, independent of the electromagnetic gauge. Moreover, an error bound for the solution of the derived gyrokinetic equation with respect to the solution of the Vlasov equation is provided, allowing us to estimate the quality of the VA-approximation in this particular case.
Global classical solutions of 2D MHD system with only magnetic diffusion on periodic domain
Authors: Zhou Yi , Zhu Yi
Published: August 2018

This paper studies the global existence of classical solutions to the two-dimensional incompressible magneto-hydrodynamical system with only magnetic diffusion on the periodic domain. The approach is based on a time-weighted energy estimate, under the assumptions that the initial magnetic field is close enough to an equilibrium state and the initial data have reflection symmetry.
Alternating chimeras in networks of ephaptically coupled bursting neurons
Authors: Majhi Soumen , Ghosh Dibakar
Published: August 2018

The distinctive phenomenon of the chimera state has been explored in neuronal systems under a variety of different network topologies during the last decade. Nevertheless, in all the works, the neurons are presumed to interact with each other directly with the help of synapses only. But, the influence of ephaptic coupling, particularly magnetic flux across the membrane, is mostly unexplored and should essentially be dealt with during the emergence of collective electrical activities and propagation of signals among the neurons in a network. Through this article, we report the development of an emerging dynamical state, namely, the alternating chimera, in a network of identical neuronal systems induced by an external electromagnetic field. Owing to this interaction scenario, the nonlinear neuronal oscillators are coupled indirectly via electromagnetic induction with magnetic flux, through which neurons communicate in spite of the absence of physical connections among them. The evolution of each neuron, here, is described by the three-dimensional Hindmarsh-Rose dynamics. We demonstrate that the presence of such non-locally and globally interacting external environments induces a stationary alternating chimera pattern in the ensemble of neurons, whereas in the local coupling limit, the network exhibits a transient chimera state whenever the local dynamics of the neurons is of the chaotic square-wave bursting type. For periodic square-wave bursting of the neurons, a similar qualitative phenomenon has been witnessed with the exception of the disappearance of cluster states for non-local and global interactions. Besides these observations, we advance our work while providing confirmation of the findings for neuronal ensembles exhibiting plateau bursting dynamics and also put forward the fact that the plateau pattern actually favors the alternating chimera more than others. These results may deliver better interpretations for different aspects of synchronization appearing in a network of neurons through field coupling that also relaxes the prerequisite of synaptic connectivity for realizing the chimera state in neuronal networks.
Limits of emission quantum yield determination
Authors: van Dam Bart , Bruhn Benjamin , Dohnal Gejza , Dohnalová Kateřina
Published: August 2018

The development of new fluorescent molecules and dyes requires precise determination of their emission efficiency, which ultimately defines the potential of the developed materials. For this, the photoluminescence quantum yield (QY) is commonly used, given by the ratio of the number of emitted and absorbed photons, where the latter can be determined by subtraction of the transmitted signal by the sample and by a blank reference. In this work, we show that when the measurement uncertainty is larger than 10% of the absorptance of the sample, the QY distribution function becomes skewed, which can result in underestimated QY values by more than 200%. We demonstrate this effect in great detail by simulation of the QY methodology that implements an integrating sphere, which is widely used commercially and for research. Based on our simulations, we show that this effect arises from the non-linear propagation of the measurement uncertainties. The observed effect applies to the measurement of any variable defined as Z = X/Y, with Y = U − V, where X, U and V are random, normally distributed parameters. For this general case, we derive the analytical expression and quantify the range in which the effect can be avoided.
Characterization of trap states in perovskite films by simultaneous fitting of steady-state and transient photoluminescence measurements
Authors: Fu Xiao , Weber Klaus J. , White Thomas P.
Published: August 2018

Understanding carrier recombination mechanisms and quantifying recombination dynamics are key to improving the performance of state-of-the-art perovskite solar cells. Here, we present a method to quantify the quality of perovskite thin films using a combination of steady-state and transient photoluminescence measurements. The combined experimental datasets are fitted using a single, general recombination model, from which detailed trap and recombination parameters can be extracted, and the accuracy of the fitted values is estimated. This approach expands the application of photoluminescence measurements to include quantitative evaluation of the most relevant defect characteristics, including trap density, energy level, and carrier capture coefficients. We apply this approach to compare perovskite films of the widely studied methyl-ammonium lead iodide (MAPbI3) with the high performance quadruple-cation, mixed-halide composition Cs0.07Rb0.03(FA0.85MA0.15)0.9Pb(I0.85Br0.15)3. Our quantitative analysis of trap properties in these perovskite films suggests that the superior performance of the quadruple cation films may be due to a greatly reduced electron capture coefficient, rather than a significant reduction in the trap density.
Electro-mechanical behavior in arrays of superconducting tapes
Authors: Yang Yu , Yong Huadong , Zhou Youhe
Published: August 2018

Numerical simulations of the electro-mechanical behavior in arrays of superconducting tapes are presented in this paper. The superconducting properties of tapes are influenced not only by the local magnetic field but also the mechanical strain. The mechanical strain will reduce the critical current density and lead to the degradation of superconductivity. Due to the nonlinear E−J behavior, it is difficult to analytically obtain the two-dimensional current and magnetic field distributions. We use the magnetic energy minimization method based on the field-dependent critical current density to determine the distributions of the current and magnetic field in arrays of rare-earth-barium-copper-oxide (REBCO) tapes. Next, the finite element method is employed to calculate the mechanical strain and stress distributions, and the anisotropic mechanical properties of the REBCO tapes are adopted. The numerical method is verified with the analytical solution for a one-dimensional single tape with transport current. The strain and stress distributions in superconducting tapes are calculated for different transport current/external magnetic field conditions. The relationship between the stress and the number of tapes in the arrays is discussed, and the effect of the distance between adjacent tapes on the stress is also investigated. The results may be beneficial to the design of superconductor magnets.
Liouville quantum gravity on the annulus
Authors: Remy Guillaume
Published: August 2018

In this work, we construct Liouville quantum gravity on an annulus in the complex plane. This construction is aimed at providing a rigorous mathematical framework to the work of theoretical physicists initiated by Polyakov in 1981. It is also a very important example of a conformal field theory (CFT). Results have already been obtained on the Riemann sphere and on the unit disk, so this paper will follow the same approach. The case of the annulus contains two difficulties: it is a surface with two boundaries and it has a non-trivial moduli space. We recover the Weyl anomaly—a formula verified by all CFT—and deduce from it the Knizhnik-Polyakov-Zamolodchikov (KPZ) formula. We also show that the full partition function of Liouville quantum gravity integrated over the moduli space is finite. This allows us to give the joint law of the Liouville measures and of the random modulus and to write the conjectured link with random planar maps.
X-ray diffraction of ramp-compressed aluminum to 475 GPa
Authors: Polsin D. N. , Fratanduono D. E. , Rygg J. R. , Lazicki A. , Smith R. F. , Eggert J. H. , Gregor M. C. , Henderson B. J. , Gong X. , Delettrez J. A. , Kraus R. G. , Celliers P. M. , Coppari F. , Swift D. C. , McCoy C. A. , Seagle C. T. , Davis J.-P. , Burns S. J. , Collins G. W. , Boehly T. R.
Published: August 2018

We report on a series of experiments that use high-power lasers to ramp-compress aluminum (Al) up to 475 GPa. Under this quasi-isentropic compression, Al remains in the solid state and two solid–solid phase transformations are observed. In situ x-ray diffraction is performed to detect the crystal structure. A velocimetry diagnostic measures particle velocities in order to infer the pressure in the Al sample. We show that a solid–solid phase transition, consistent with a transformation to a hexagonal close-packed (hcp) structure, occurs at 216 ± 9 GPa. At higher pressures, a transformation to a structure consistent with the body-centered cubic (bcc) structure occurs at 321 ± 12 GPa. These phase transitions are also observed in 6061-O (annealed) Al alloy at 175 ± 9 GPa and 333 ± 11 GPa, respectively. Correlations in the high-pressure crystallographic texture suggests the close-packed face-centered cubic (fcc) (111), hcp (002), and bcc (110) planes remain parallel through the solid–solid fcc–hcp and hcp–bcc transformations.
Onset of centrifugal instability at a rotating cylinder in a stratified fluid
Authors: Flór J. B. , Hirschberg L. , Oostenrijk B. H. , van Heijst G. J. F.
Published: August 2018

In this experimental note, we consider the centrifugal instability of a laminar shear layer, generated by the impulsive start of the rotation of a circular solid cylinder about its vertical axis immersed in a linearly stratified fluid. The flow is determined by the Reynolds number, Re, based on the cylinder rotation rate and the cylinder radius, and the Froude number, Fr, represented by the ratio of the rotation frequency Ω over the buoyancy frequency N. The onset of the instability starts when the boundary layer reaches a certain thickness. We show for this boundary layer that there is a transition from the centrifugally unstable regime to a wave-like regime at Fr ≈ 1 and a stable flow below a critical Reynolds number. We focus on the centrifugally unstable regime Fr⪆1, for which the onset time and wavelength are predicted by scaling laws that depend on the Reynolds number. Agreement with the theoretical prediction of Kim and Choi [“The onset of instability in the flow induced by an impulsively started rotating cylinder,” Chem. Eng. Sci. 60, 599–608 (2005)] in a homogeneous fluid confirms that the instability of this boundary layer is not modified by the presence of stratification. These results therefore show that the centrifugal instability of the spin-up boundary is dominated by inertial motions, suggesting that close lateral boundaries, as in thin-gap stratified Taylor-Couette flow, increase the effects of buoyancy on the instability and wavelength.