From Wires to Cables: Attempted Synthesis of 1,3,5-Trifluorenylcyclohexane as a Platform for Molecular Cables

Multiple molecular wires braided together in a single assembly, termed as molecular cable, are promising next-generation materials for effective long-range charge transport. As an example of the platform for constructing molecular cables, 1,3,5-trifluorenylcyclohexane (TFC) and its difluorenyl analogues (DFCs) were systematically investigated both experimentally (X-ray crystallography) and theoretically (DFT calculations). Although the syntheses of DFCs were successfully achieved, the synthesis of TFC, which involved a similar intramolecular Friedel–Crafts cyclization as the last step, was unsuccessful. An exhaustive study of the conformational landscape of cyclohexane ring of TFC and DFCs revealed that TFC is a moderately strained molecule (∼17 kcal/mol), and computational studies of the reaction profile show that this steric strain, present in the transition state, is responsible for the unusually high (∼5 years) reaction half-life. A successful synthesis of TFC will require that the steric strain is introduced in multiple steps, and such alternative strategies are being currently explored

Reputation-based security protocol for MANETs in highly mobile disconnection-prone environments

This paper is concerned with fully distributed reputation-based mechanisms that improve security in MANETS. We introduce a number of optimisations to the current reputation schemes used in MANETs such as selective deviation tests and adaptive expiration timer that aim to deal with congestion and quick reputation convergence. We propose to use two different centrality measures for evaluation of the individual trust claims and resolving the aggregated ones. We design and build our prototype over AODV and test it in NS-2 in the presence of variable active blackhole attacks in highly mobile and sparse networks. Our results show that we achieve increased throughput while delay and jitter decrease and converge to AODV

Impact of chylothorax on the post operative outcome after pediatric cardiovascular surgery

BackgroundChylothorax is the accumulation of chyle in the pleural cavity, usually develops after disruption of the thoracic duct along its intra-thoracic route. In the majority of cases this rupture is secondary to trauma (including cardio thoracic surgeries). Chylothorax is a potentially serious complication after cardiovascular surgeries that require early diagnosis and adequate management.MethodsA retrospective study of all cases complicated with chylothorax after pediatric cardiac surgery in King Abdulaziz Cardiac Center between January 2007 and December 2009 was conducted. The study aim to determine the risk factors, and the impact on the post operative course.ResultsWe have 1135 cases operated during the study period, 57 cases (5%) were complicated with chylothorax in the post operative period. The most common surgeries complicated with chylothorax were the single ventricle repair surgeries (Glenn-Fontan) 15 cases (27%), followed by the arch repair cases 10 cases (18%), the ventricular septal defect cases 10 cases (18%), the Atrioventricular septal defect cases 7 cases (12%), the arterial switch cases 6 cases (11%), and others 8 cases (14%). The ICU stay, the length of hospital stay and the bypass time were significantly longer in the chylothorax group, also the ventilation time, the inotropes duration and number were higher in the chylothorax group.ConclusionChylothorax after pediatric open heart surgery is not an uncommon complication, it occurs more commonly with single ventricle repair and aortic arch repair surgeries, it has a significant impact on the post operative course and post operative morbidity

Towards a multidimensional self-assessment for software process improvement: a pilot tool

The SPI Manifesto provides a framework for guiding software development organisations in their improvement efforts. Based on the Values of People, Business and Change, which are supported and informed by one or more of the ten principles, the designer and developer can avoid pitfalls, minimise risks and make their business successful. It has been established, in theory and practice, that improving the process results in improvement of the products and services emanating from that process. Following a number of earlier multidimensional analyses of the SPI Manifesto, carried out by the authors, a series of tabular representations identifying the nature, importance and strength of relationships between the Manifesto’s Values and Principles in terms of eight dimensions encapsulated in the acronym STEEPLED (Sociocultural, Technical, Economic, Environmental, Political, Legal, Ethical and Demographic) were developed. In this paper, we present a conceptualisation of a pilot automated tool (based on the STEEPLED Analysis), which could, potentially, be implemented/realised and used for self-assessment by software developing organisations. Starting with a self-assessment, current issues and requirements could be identified and revealed. The self-assessment using the pilot automated tool would, additionally, reveal areas requiring improvement, and would serve as a guide for the participating organisation to put focus on prioritising candidate process areas that require improvement. Also, the field testing of the pilot tool could enable the design and improvement of the tool itself, which, in turn, will be used in future for expert external/independent process assessment

A GPU-based hyperbolic SVD algorithm

A one-sided Jacobi hyperbolic singular value decomposition (HSVD) algorithm, using a massively parallel graphics processing unit (GPU), is developed. The algorithm also serves as the final stage of solving a symmetric indefinite eigenvalue problem. Numerical testing demonstrates the gains in speed and accuracy over sequential and MPI-parallelized variants of similar Jacobi-type HSVD algorithms. Finally, possibilities of hybrid CPU--GPU parallelism are discussed.Comment: Accepted for publication in BIT Numerical Mathematic

РОЛЬ EZH2 И ARID1A В ДИАГНОСТИКЕ ПЛОСКИХ УРОТЕЛИАЛЬНЫХ ОПУХОЛЕЙ С АТИПИЕЙ

Background. Diagnosis of urothelial carcinoma in situ is of great importance because it has prognostic and therapeutic value.We aim to determine the utility of EZH2 and ARID1A as a new tool in the diagnosis of carcinoma in situ.Material and Methods. This retrospective cross-sectional study included Twenty-four specimens of flat urothelial lesions, twenty specimens of CIS, and 10 of normal adjacent urothelium that was taken by cystoscopic resection biopsy procedure. immunohistochemical expression of EZH2 and ARID1A. were evaluated in all studied cases.Results. All normal urothelium specimens showed high nuclear staining for ARID1A and negative nuclear staining for EZH2. High EZH2 expression was observed in 80 % of CIS specimens compared to 20 % of flat urothelial lesions with atypia (p=0.001 ), while high ARID1A expression was observed in 70.8 % of flat urothelial lesions with atypia compared to 25 % of CIS specimens (p=0.001). EZH2 was more accurate and specific in the diagnosis of carcinoma in situ.Conclusion. EZH2 and ARID1A are promising diagnostic markers for urothelial CIS. EZH2 is more accurate and specific than ARID1A in the diagnosis of carcinoma in situ versus other flat urothelial lesions. Актуальность. Диагностика уротелиальной карциномы in situ имеет большое значение, поскольку обладает прогностической и терапевтической ценностью.Целью исследования было определить роль EZH2 и ARID1A в диагностике карциномы in situ.Материал и методы. Ретроспективное перекрестное исследование включало 24 образца плоских уротелиальных опухолей, 20 образцов CIS и 10 образцов нормального прилегающего уротелия, взятых при цистоскопической биопсии. Во всех случаях была оценена иммуногистохимическая экспрессия EZH2 и ARID1A.Результаты. Все образцы нормального уротелия показали высокое ядерное окрашивание на ARID1A и отрицательное ядерное окрашивание на EZH2. Высокая экспрессия EZH2 наблюдалась в 80 % образцов CIS по сравнению с 20 % плоских уротелиальных опухолей с атипией (p=0,001), в то время как высокая экспрессия ARID1A наблюдалась в 70,8 % плоских уротелиальных опухолей с атипией по сравнению с 25 % образцов CIS (р=0,001). EZH2 был более точным и специфичным при диагностике карциномы in situ.Заключение. EZH2 и ARID1A являются перспективными диагностическими маркерами уротелиальной карциномы in situ. EZH2 более точен и специфичен, чем ARID1A, в диагностике карциномы in situ по сравнению с другими плоскими уротелиальными опухолями.

Scaling the Stiffness, Strength, and Toughness of Ceramic‐Coated Nanotube Foams into the Structural Regime

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108652/1/adfm201400851-sup-0001-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/108652/2/adfm201400851.pd