Exotic Monoliths

This thesis is entitled 'Exotic Monoliths', which has been defined, in the context of this thesis, as monoliths; (1) synthesised by methods not previously described in the literature, (2) synthesised from commonly used silica or organic polymer materials but whose surface has been modified with a novel material such as dyes, nano-particles and biologically active compounds, and (3) synthesised from materials which are not based on silica or organic polymers, such as zirconia or titania. The first two of these definitions have been the main focus for this thesis. The thesis itself comprises five chapters. Chapter 1 presents an introduction to polymer monolith stationary phases and a detailed summary of the many different methods of synthesis. The surface modification of the monoliths and their applications in separation science, along with a short comparison with particle packed columns and introduction to some more novel inorganic monoliths is also presented. Following on from this, Chapter 2 shows the preliminary work carried out on synthesising monoliths in capillary. Presented in this chapter is an investigation of thermally initiated polymerisation in standard 100 μm i.d. capillary and in larger diameter fused silica and PEEK capillary moulds. Photo-initiated polymerisation using both conventional UV lamps and light emitting diodes is also investigated, along with a novel application of LED synthesised monoliths, i.e. using short plugs of monoliths as retaining frits for column packing. Finally a short study of the ability to reproduce literature methods of surface modification by successfully grafting a layer of methacrylic acid and 2-aminoethyl methacrylate on the surface of a monolithic scaffold is shown. Chapter 3 presents the research carried out on the modification of organic polymer monoliths with photochromic dyes and the synthesis of monoliths directly from modified photochromic dyes with a polymerisable double bond. A novel application of these photochromic monoliths is their use as photo-switchable electroosmotic pumps allowing eluent flow to be controlled by light in micro-fluidic devices, which is also presented in this chapter. It is shown that by switching the wavelength of irradiation from visible to ultraviolet an increase or decrease, respectively, in the flow rate can be observed. The final two chapters, 4 and 5, present novel methods of monolith synthesis using light emitting diodes in the visible region. Chapter 4 looks at the polymerisation of methacrylate monomers within polyimide coated moulds using red light while Chapter 5 looks at the polymerisation of styrenic monomers in poly(tetrafluoroethylene) coated capillaries using blue light emitting diode arrays. In both cases the characterisation and application of the synthesised monoliths is presented showing that they are suited to use in separation science. The suitability of this method to polymerise monoliths in chips moulds was also shown, as was the ability of the initiation system activated by red light to be used for the photo-initiated grafting of chromophoric monomers. A final section entitled 'General Conclusions and Outlook' provides a summary of the thesis and areas for further work

Employees' perception of how managers motivate their subordinates

Employees who are motivated to perform are typically more productive by investing more of themselves in their work (Salvendy, 2012). Responsibility is also placed on the leadership of an organisation where motivating employees is seen as a core competency (Latham, 2012). This research focused on employee perception of how managers motivate their subordinates, analysing the impact of leadership on employee motivation. A qualitative approach was adopted, using semi-structured interviews (SSI) as the method of data collection. Interviews were held by the research with eight participants (aged between 18 and 23 years), all of which have been in employment between 6 months and three years within a customer care role. Thematic analysis was applied to the collected data. The questions were all designed to answer the main research question; ‘What is the employees’ perception of how leaders motivate their subordinates?’ Running the SSI allowed the researcher to gather data which was analysed to find common themes. Thematic analysis (Braun & Clarke, 2013) was used to interpret the experiences of individuals within their organisations. The results showed that all participants were affected by similar experiences represented in themes, namely implicit communication, explicit communication and relationships at work. The research concluded that leadership did have an impact on employee motivation and a great emphasis was placed upon the relationship between employee and superior. Practical implications of the study suggested that leaders should understand the importance of their role in relation to motivation, by placing more focus on developing incentive schemes based on employee feedback as well as implementing intrinsic rewards. Future research is recommended to gain the perspective of leaders on this issue and to examine how different leadership styles may affect employee motivation within different occupational backgrounds

Att leda framtidens arbetskraft En kvalitativ studie av ledarskapets inflytande på medarbetares arbetsengagemang och motivation

“The majority of the Swedish workforce is currently disengaged from their job roles, resulting not only in huge financial losses for companies and organisation, but also results in a less effective and more detached workforce (Gallup, 2013a). With the competition rising of one large generation leaving the workplace and a smaller generation joining to the workplace, it is crucial for organisations to learn how to adapt to and attract ‘generation Y’. This study aims to find if and how youth between the ages of 18-30 become engaged at work, as well as looking at what form of leadership they respond well to in terms of workplace engagement. In order to achieve this, a qualitative study of management and the perception of managerial behaviour was conducted through seven interviews with respondents who have been a part of one of the largest student-run organisations in the world, that has a similar structure to a corporation, but rewards those engaged as volunteers. These interviews were summarised to consolidate one common perception of the phenomena.Transformational leadership according to Burns (1978) and the two-factor theory (Herzberg, Mausner & Snyderman, 2010) was applied to answer the question of ‘What affects engagement in the workplace?’ and ‘In what way may managers or business leaders encourage workplace engagement? The main conclusions that can be drawn from this thesis is that workplace engagement is most affected by the social relations and interactions associated with the workplace as well as the meaningfulness of the work itself. The consistent component of the respondents’ motivation was the people they were working with and had an impact on. This has the implication that leaders and business managers can and should encourage this type of engagement by promoting a healthy work environment which focuses on the human connection in the workplace, in order to become more competitive in regards to workforce competition as well as increasing the effectiveness of the operations.

Att leda framtidens arbetskraft En kvalitativ studie av ledarskapets inflytande på medarbetares arbetsengagemang och motivation

“The majority of the Swedish workforce is currently disengaged from their job roles, resulting not only in huge financial losses for companies and organisation, but also results in a less effective and more detached workforce (Gallup, 2013a). With the competition rising of one large generation leaving the workplace and a smaller generation joining to the workplace, it is crucial for organisations to learn how to adapt to and attract ‘generation Y’. This study aims to find if and how youth between the ages of 18-30 become engaged at work, as well as looking at what form of leadership they respond well to in terms of workplace engagement. In order to achieve this, a qualitative study of management and the perception of managerial behaviour was conducted through seven interviews with respondents who have been a part of one of the largest student-run organisations in the world, that has a similar structure to a corporation, but rewards those engaged as volunteers. These interviews were summarised to consolidate one common perception of the phenomena.Transformational leadership according to Burns (1978) and the two-factor theory (Herzberg, Mausner & Snyderman, 2010) was applied to answer the question of ‘What affects engagement in the workplace?’ and ‘In what way may managers or business leaders encourage workplace engagement? The main conclusions that can be drawn from this thesis is that workplace engagement is most affected by the social relations and interactions associated with the workplace as well as the meaningfulness of the work itself. The consistent component of the respondents’ motivation was the people they were working with and had an impact on. This has the implication that leaders and business managers can and should encourage this type of engagement by promoting a healthy work environment which focuses on the human connection in the workplace, in order to become more competitive in regards to workforce competition as well as increasing the effectiveness of the operations.

Surgeon radiation exposure in hip arthroscopy: A prospective analysis

Objectives: Hip arthroscopy is an established field within orthopaedic surgery. The majority of the procedures involve repairs of the acetabular labrum and arthroscopic treatment of femoroacetabular impingement (FAI). The procedures are being performed with increasing frequency annually. Fluoroscopic guidance is recommended during these procedures, and radiation exposure to the surgeon, staff, and patient remains a valid concern. The purpose of this study is to measure radiation exposure to the surgeon during hip arthroscopy and determine if this exposure remains below recommended annual occupational radiation exposure thresholds recommended by the International Committee on Radiological Protection (IRCP). Methods: Prospectively, radiation exposure was measured for a single surgeon at a single outpatient facility for all hip arthroscopic procedures over a three-year period. A radiation dosimeter was worn outside of the surgeon’s chest on the lead apron. Standard pre-operative and intra-operative imaging was used for all patients. Radiation readings were prospectively measured for deep dose equivalent (DDE), lens dose equivalent (LDE), and shallow dose equivalent (SDE). The cumulative radiation exposure was tabulated in millirem (mrem), converted to milli-Sieverts (mSv) (standard measurement used by the IRCP) and then the per-patient exposure calculated as well as annual exposure for 100 hip arthroscopies per year. Results: Between July 2011 and July 2014, 209 patients underwent a total of 280 hip arthroscopy procedures at a single facility by a single surgeon. There were 90 labral repairs, 83 femoroplasties, 26 acetabuloplasties, 66 labral debridements, 8 trochanteric bursectomies, and 7 iliopsoas releases. The cumulative DDE was 183 mrem (1.83 mSv), LDE 183 mrem (1.83 mSv), and SDE 176 mrem (1.76 mSv). The calculated per patient exposure for the surgeon was DDE 0.875 mrem (0.00875 mSv), LDE 0.875 mrem (0.00875 mSv), and SDE 0.842 mrem (0.00843 mSv). Calculated annual exposure for a surgeon performing 100 hip arthroscopies per year are DDE 8.75 mrem (0.0875 mSv), LDE 8.75 mrem (0.0875 mSv), and SDE 8.43 mrem (0.0842 mSv). Conclusion: Hip arthroscopy & hip preservation procedures are being performed with increasing frequency annually. Fluoroscopic guidance is recommended for safe entrance into the central compartment and during various parts of the procedures. Radiation exposure to the surgeon, staff, and patient is a valid concern. The IRCP sets recommended annual safety thresholds for occupational radiation exposure. Current annual safety thresholds are 50,000 mrem (500 mSv) to the hands, 50,000 mrem (500 mSv) to the skin, hands & feet, 15,000 mrem (150 mSv) to the eye, and 30,000 mrem (300 mSv) to the thyroid of healthcare workers. Our study shows surgeon radiation exposure below the annual safety thresholds recommended by the IRCP for 100 cases per year. For surgeons performing more than 100 hip arthroscopic procedures annually, the exposure will be higher. Appropriate safety equipment such as lead aprons, thyroid shields, and leaded glasses are still recommended, especially for high volume hip arthroscopists. © The Author(s) 2015

Spiropyran modified PDMS micro-fluidic chip device for photonically controlled sensor array detection of metal ions

Micro‐fluidic chips are particularly attractive in biological and life sciences for analytical purposes because they provide a convenient small platform for rapid analysis and detection [1]. Using micro‐fluidic devices for the determination of ions emerges as a potential solution to some of the challenges not overtaken by conventional techniques e.g. atomic absorption, inductively‐coupled plasma‐optical emission, mass spectrometry and ion‐selective electrodes [2]. For example, these devices can integrate complex sample handling processes, calibration, and detection steps into a compact, portable system. Moreover they require small sample volumes (low μl or nl), consume little power, and are easily constructed for multi‐analyte detection, either through multiple parallel fluidic architectures or by using arrays of detection elements. Organic photochromic compounds like spiropyrans are particularly interesting targets for the development of new approaches to sensing since they offer new routes to multi‐functional materials that take advantage of their photo‐reversible interconversion between two thermodynamically stable states (a spiropyran (SP) form, and a merocyanine (MC) form), which have dramatically different charge, polarity and molecular conformations. Furthermore, they can be easily incorporated into membranes for improved robustness and ease of handling [3], but from our perspective, most interesting of all, they have metal ion‐binding and molecular recognition properties which are only manifested by the MC form. Based on the coordinationinduced photochromism characteristic of the MC form, spiropyrans have been employed as molecular probes for metal ions and organic molecules [4]. In this abstract, we show how through integrating the beneficial characteristics of micro‐fluidic devices and spiropyrans photoswitches, a simple and very innovative chip configured as an on‐line metal ion sensor array can be realised (Figure 1). The micro‐fluidic device consists of five independent 94 μm depth, 150 μm width channels fabricated in polydimethylsiloxane. The spiropyran 1’‐(3‐carboxypropyl)‐3,3’‐dimethyl‐6‐nitrospiro‐1‐benzopyran‐2,2’‐indoline (SP‐COOH) is immobilised by physical adsorption directly on ozone plasma activated PDMS micro‐channel walls. When the colourless, inactive, spiropyran coating absorbs UV light it switches to the highly coloured merocyanine form (MC‐COOH), which also has an active binding site for certain metal ions. Therefore metal ion uptake can be triggered using UV light and subsequently reversed on demand by shining white light on the coloured complex, which regenerates the inactive spiropyran form, and releases the metal ion. When stock solutions of several metal ions (Ca2+, Zn2+, Hg2+, Cu2+, Co2+) are pumped independently through the five channels, different optical responses were observed for each metal (Figure 2), (i.e. complex formation with metal ions is associated with characteristic shifts in the visible spectrum), and the platform can therefore be regarded as a micro‐structured device for online multi‐component monitoring of metal cations

Spiropyran modified microfluidic chip channels for photonically controlled sensor array detection of metal ions

Microfluidic chips are particularly attractive for analytical purposes because they provide a convenient small platform for rapid analysis and detection.1 Furthermore, spiropyrans dyes can be used as photonically controlled, self-indicating molecular recognition agents for the fabrication of sensors.2 Here, we show how through integrating the beneficial characteristics of microfluidic devices and spiropyrans dyes, a simple and very innovative chip for on-line metal ion sensor array can be realised. The chip (4x3cm) consists of four independent 180m depth, polydimethylsiloxane (PDMS) channels. 1’-(3-Carboxypropyl)-3,3’-dimethyl-6-nitrospiro-[2H-1]-benzopyran-2,2’-indoline is covalently immobilised on the ozone plasma activated PDMS microchannel surfaces. Upon exposure to UV light, the transparent PDMS channels change to light purple colour because the spiropyran molecules of the surface undergo a heterocyclic ring cleavage that result in the formation of the highly conjugated merocyanine form. When stock solutions of several ion metals (Ca2+,Zn2+,Hg2+,Cu2+) are pumped independently through the four channels, different optical responses were observed for each metal. 1-L.Basabe-Desmonts et al. Anal.Bioanal.Chem.(2008)390:307–315. 2-R.J.Byrne et al. J.Mat.Chem.(2006)16:1332-1337