Corporate governance mechanisms and asymmetric information : an application on the U.K. capital market

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Cardiac Myxomas: A single center experience and ten-years follow up

Background: Cardiac myxoma is a benign tumor that carries the risk of embolization and obstruction of the blood flow. The ideal surgical approach is still debatable. We present our experience in the surgical treatment of cardiac myxomas and its ideal surgical approach.Methods: We retrospectively analyzed the data for all patients who underwent surgical excision of cardiac myxoma at our institution over 11 years starting from January 2006 to December 2016. Descriptive statistics were used to present preoperative, operative and postoperative data and Kaplan Meier curve to plot long-term survival.Results: Twenty-one patients had surgical excision of a primary, single and sporadic cardiac myxoma. Thirteen patients (62 %) were females, and the mean age at operation was 55.2 years (range: 28 – 71 years). The location of myxomas was in the left atrium in 17 patients (81%) and right atrium in 4 patients (19 %). Dyspnea was the main presenting symptom (71.4%) followed by constitutional symptoms (28%), palpitations (23.8%), syncope (14.2%) and stroke (14.2%). A right atrial trans-septal incision was used in 76.5% of left atrial myxoma cases. Five patients had concomitant operative procedures (coronary artery bypass grafting (n=2), tricuspid valve repair (n=1), mitral valve replacement (n=1) and bullectomy (n=1)). Postoperative complications were reported in six patients (28.6%) (supraventricular arrhythmia (n=2), temporary conduction deficit (n=2), pulmonary atelectasis (n=1), and postoperative bleeding (n=1)). Early postoperative mortality occurred in one patient (4.76 %), and there were no late deaths related to myxoma.Conclusion: Surgical treatment of cardiac myxoma is safe with low morbidity and mortality. The right atrial trans-septal incision is the recommended surgical approach

Integrating entrepreneurship into chemistry education - Cairo University post-graduate students' case study

Chemistry entrepreneurship is the technique of spreading knowledge about discoveries and chemical ideas to a larger audience outside of the classroom and evaluation. Graduates' ability to become job innovators with the potential to reduce unemployment and strengthen the economy is demonstrated by innovative ideas that are implemented with a social value. As a result, while attending college, chemistry students have the chance to apply what they learn in the classroom to a sustainable way of life. In this study, we have covered the breadth of classroom innovations, the "From Theory to Practice" gap, and different aspects that affect students' decisions to start and develop chemistry entrepreneurial ventures. a survey was conducted to find out more about post-graduate students' exposure to and opinions on using entrepreneurship to apply chemistry to the real world. After compiling data from an online survey consisting of 20 statements from 176 post-graduate chemistry students (Ph. D., M. Sc., and diploma) with their replies recorded on a Likert scale describing their experiences with assignments, it was possible to pinpoint areas where chemistry classes could be improved. In order to better understand how students, view the use of entrepreneurship to apply chemistry to the real world, a study was conducted to look at the breadth of creativity, the gap between thinking and doing, and the factors encouraging students to select and build a chemical pilot project

Letter: The Impact of the Coronavirus (COVID-19) Pandemic on Neurosurgeons Worldwide

This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.The aim of our study was to explore the impact of this pandemic on neurosurgeons with the hope of improving preparedness for future crisis. We created a 20-question survey designed to explore demographics (nation, duration and scope of practice, and case-burden), knowledge (source of information), clinical impact (elective clinic/surgery cancellations), hospital preparedness (availability of personal protective equipment [PPE] and cost of the supplies), and personal factors (financial burden, workload, scientific and research activities). The survey was first piloted with 10 neurosurgeons and then revised. Surveys were distributed electronically in 7 languages (Chinese, English, French, German, Italian, Portuguese, and Spanish) between March 20 and April 3, 2020 using Google Forms, WeChat used to obtain responses, and Excel (Microsoft) and SPSS (IBM) used to analyze results. All responses were cross-verified by 2 members of our team. After obtaining results, we analyzed our data with histograms and standard statistical methods (Chi-square and Fisher's exact tests and logistic regression). Participants were first informed about the objectives of our survey and assured confidentiality after they agreed to participate (Helsinki declaration). We received 187 responses from 308 invitations (60.7%), and 474 additional responses were obtained from social media-based neurosurgery groups (total responses = 661). The respondents were from 96 countries representing 6 continents (Figure ​(Figure11A-​A-11C)

Bacteria-inducing legume nodules involved in the improvement of plant growth, health and nutrition

Bacteria-inducing legume nodules are known as rhizobia and belong to the class Alphaproteobacteria and Betaproteobacteria. They promote the growth and nutrition of their respective legume hosts through atmospheric nitrogen fixation which takes place in the nodules induced in their roots or stems. In addition, rhizobia have other plant growth-promoting mechanisms, mainly solubilization of phosphate and production of indoleacetic acid, ACC deaminase and siderophores. Some of these mechanisms have been reported for strains of rhizobia which are also able to promote the growth of several nonlegumes, such as cereals, oilseeds and vegetables. Less studied are the mechanisms that have the rhizobia to promote the plant health; however, these bacteria are able to exert biocontrol of some phytopathogens and to induce the plant resistance. In this chapter, we revised the available data about the ability of the legume nodule-inducing bacteria for improving the plant growth, health and nutrition of both legumes and nonlegumes. These data showed that rhizobia meet all the requirements of sustainable agriculture to be used as bio-inoculants allowing the total or partial replacement of chemicals used for fertilization or protection of crops

Semidry acid hydrolysis of cellulose sustained by autoclaving for production of reducing sugars for bacterial biohydrogen generation from various cellulose feedstock

Cellulosic biowastes are one of the cheapest and most abundant renewable organic materials on earth that can be, subsequent to hydrolysis, utilized as an organic carbon source for several fermentation biotechnologies. This study was devoted to explore a semidry acid hydrolysis of cellulose for decreasing the cost and ionic strength of the hydrolysate. For semidry acid hydrolysis, cellulose was just wetted with HCl (0 to 7 M) and subjected to autoclaving. The optimum molar concentration of HCl and period of autoclaving for semidry acid hydrolysis of cellulose were 6 M and 50 min respectively. Subsequent to the semidry acid hydrolysis with a minimum volume of 6 M HCl sustained by autoclaving, the hydrolysate was diluted with distilled water and neutralized with NaOH (0.5 M). The reducing sugars produced from the semidry acid hydrolysis of cellulose was further used for dark fermentation biohydrogen production by Escherichia coli as a representative of most hydrogen producing eubacteria which cannot utilize non-hydrolyzed cellulose. An isolated E. coli TFYM was used where this bacterium was morphologically and biochemically characterized and further identified by phylogenetic 16S rRNA encoding gene sequence analysis. The reducing sugars produced by semidry acid hydrolysis could be efficiently utilized by E. coli producing 0.4 mol H2 mol−1 hexose with a maximum rate of hydrogen gas production of 23.3 ml H2 h−1 L−1 and an estimated hydrogen yield of 20.5 (L H2 kg−1 dry biomass). The cheap cellulosic biowastes of wheat bran, sawdust and sugarcane bagasse could be hydrolyzed by semidry acid hydrolysis where the estimated hydrogen yield per kg of its dry biomass were 36, 18 and 32 (L H2 kg−1 dry biomass) respectively indicating a good feasibility of hydrogen production from reducing sugars prepared by semidry acid hydrolysis of these cellulosic biowastes. Semidry acid hydrolysis could also be effectively used for hydrolyzing non-cellulosic polysaccharides of dry cyanobacterial biomass. The described semidry acid hydrolysis of cellulosic biowastes in this study might be applicable not only for bacterial biohydrogen production but also for various hydrolyzed cellulose-based fermentation biotechnologies