Laboratory evaluation of a novel anaesthesia delivery device

Here, we describe proof of concept of a novel method for delivering volatile anaesthetics, where the liquid anaesthetic (sevoflurane or isoflurane) is formulated into an emulsion that is contained in a compact, lightweight device through which carrier gas flows. Release of anaesthetic is achieved by stirring of the formulation, allowing controlled and responsive release of anaesthetic at a variety of fixed flow rates between 0.5 l.min−1 and 5 l.min−1, with ventilated, non-ventilated and draw-over breathing systems. Anaesthetic release was evaluated using target anaesthetic concentrations ranging from 0.5% v/v to 8% v/v to mimic those typically required for induction and maintenance of anaesthesia, and lower concentrations suitable for sedation. Under all conditions, output could be maintained within 0.1% v/v of the intended setting, and the device could deliver a controlled level of anaesthetic for at least 60 min, with compensation for different ambient temperatures (10–30 °C) and carrier gas flow rates. This device offers a simple, inexpensive method of delivering safe concentrations of volatile anaesthetics for a wide range of applications

Distribution and function of TRP ion channels in primary sensory neurons

It is frequently argued that cannabinoids exert part of their analgesic and anti-inflammatory effects via activation of the cannabinoid CB1 receptor located on TRPV1-expressing primary sensory nerve fibres in peripheral tissues. However, we find no evidence of CB1 receptor immunoreactivity on nerve fibres in rat or mouse hindpaw skin and mesenteric artery. The CB1 receptor agonists anandamide and HU210 also fail to inhibit TRPV1-mediated calcitonin gene-related peptide (CGRP) release from primary sensory neurons in rat hindpaw skin and mesenteric artery. Therefore, this study do not support the general view that the analgesic and anti-inflammatory effects of CB1 receptor agonists are due to direct inhibition of TRPV1-expressing primary sensory nerve terminals in the periphery. Garlic contains a number of organosulphur compounds, including allicin and diallyl disulfide (DADS), some of which may contribute to its pungent and vasodilator properties. Our results show that raw garlic extract, allicin and DADS activate TRPA1 ion channels on primary sensory neurons in culture and nerve fibres in the vascular system. These findings highlight TRPA1 as a novel ion channel in the vascular system and provide novel pharmacological tools for investigating the role of this ion channel. Whether activation of TRPA1 in the vascular system explains the beneficial antihypertensive effect observed by garlic treatment remains to be shown. This study also expands our understanding of how TRPA1 is regulated on a molecular basis, which is of importance for development of novel drug therapies for pain, inflammation and vascular disease. The skin is a major sensory organ that contains a large number of nerves. The TRP ion channels TRPV2 and TRPM8 are expressed in the somatosensory nervous system in animals and are therefore likely to be expressed in humans as well. Fluorescence immunohistochemistry was used to identify these channels and compare their expression and distribution patterns with known neuronal markers of the sensory nervous system in skin from healthy volunteers and from individuals with a mutation in the gene encoding nerve growth factor beta (NGF?) that causes Norrbottnian congenital insensitivity to pain. This study shows for the first time the presence of TRPV2 and TRPM8 in sensory nerves in the human skin. TRPV2 and TRPM8 as well as TRPV1 immunoreactive nerve fibres are present in unmyelinated nerve fibres in epidermis and papillary dermis, in nerve bundles, and around blood vessels and hair follicles. In contrast to TRPV1, TRPV2 and TRPM8 are found mainly in the papillary dermis and seem to be restricted to peptidergic nerve fibres, of which the majority contains the sensory neuropeptides CGRP or SP. There is a substantial loss of nerve fibres containing TRPV1, TRPV2 and TRPM8 in skin from individuals with Norrbottnian congenital insensitivity to pain. Insight into the role of TRPV2 and TRPM8 in human skin may open new avenues for treatment of neuropathic pain and inflammatory skin diseases

Medical Laser-Induced Thermotherapy - Models and Applications

Heat has long been utilised as a therapeutic tool in medicine. Laser-induced thermotherapy aims at achieving the local destruction of lesions, relying on the conversion of the light absorbed by the tissue into heat. In interstitial laser-induced thermotherapy, light is focused into thin optical fibres, which are placed deep into the tumour mass. The objective of this work was to increase the understanding of the physical and biological phenomena governing the response to laser-induced thermotherapy, with special reference to treatment of liver tumours and benign prostatic hyperplasia. Mathematical models were used to calculate the distribution of light absorption and the subsequent temperature distribution in laser-irradiated tissues. The models were used to investigate the influence on the temperature distribution of a number of different factors, such as the design of the laser probe, the number of fibres, the optical properties of the tissue, the duration of irradiation, blood perfusion and boundary conditions. New results concerning transurethral microwave thermotherapy were obtained by incorporating the distribution of absorbed microwaves into the model. Prototypes of new laser applicators for anatomically correct treatment of benign prostatic hyperplasia were developed and tested ex vivo. Experimental work on liver tumours pointed to the importance of eliminating the blood flow in the liver during treatment to reduce convective heat loss. In addition, it was shown that hepatic inflow occlusion during treatment increased the thermal sensitivity of tumour tissue. The dynamic influence of interstitial laser thermotherapy on liver perfusion was investigated using interstitial laser Doppler flowmetry. Vessel damage after the combined treatment of laser-induced heat treatment and photodynamic therapy was studied

Gas exchange with a reflecting system for inhalational anaesthesia

In order to reduce comsumption of inhalational anaesthetsics during high flow anaesthesia a system open in regard to oxygen, nitogen and nitrous oxide, but closed to inhalational anaesthetics, was developed. This was achieved by a reflecting filter for inhalational anaesthetics made of active carbon. The principle has been developed into the commersially available Anesthetic Conserving Device (ACD, AnaConDa®).The ACD is a modified heat- and moisture exchanger (HME) containing av bacterial and viral filter as well as a carbon filter. The ACD can be used during surgery for administering the inhalational agents isoflurane and sevoflurane as an alternative to low-flow anaesthesia systems. It can also be used in intensive care units to administer sedation using isoflurane or sevoflurane to critically ill patients. The thesis is based on four papers. In paper I it is shown that that the wash-in kinetics for sevoflurane delivered by the ACD is similar to a vaporiser. With the ACD, end-tidal sevoflurane accurately reflects arterial sevoflurane tension whereas inspired tension may be underesteimated. Despite an increase in tidal volume of patients in a group with an ACD corresponding to the larger internal volume of the device compared to a conventional HME, the PaCO2 was considerably higher in this group. In paper II CO2 exchange and airway dead space is compared using an HME, ACD without reflecting filter and ACD with reflecting filter in a laboratory set-up. It is shown that the ACD binds CO2 resulting in a dead space effect 180 ml in excess of its internal volume. This is due to adsorption of CO2 in the ACD during expiration and return of CO2 during the following inspiration. In paper III the ACD is used without inhalational anaesthetics in patients as well as in a laboratory set-up with varying temperature and humidity. It is confirmed that an ACD used in humans as well as in a test lung increases the dead space effect and CO2 rebreathing to a greater extent than can be explained by its internal volume. This is caused by adsorption of CO2 in the ACD during expiration and release of CO2 during inspiration. It is also shown that rebreathing of CO2 is attenuated but not abolished by humidity. In paper IV the ACD is used with sevoflurane in humans and in a laboratory set-up. It is shown that sevoflurane attenuates but does not abolish rebreathing of CO2, thereby reducing the dead space effect of the ACD. In conlusion, the ACD causes a dead space effect larger than its internal volume due to CO2 rebreathing. This may influence the clinical use of the ACD

Teleworking practice in small and medium-sized firms: Management style and worker autonomy

In an empirical study of teleworking practices amongst small and medium-sized enterprises (SMEs) in West London, organisational factors such as management attitudes, worker autonomy and employment flexibility were found to be more critical than technological provision in facilitating successful implementation. Consequently, we argue that telework in most SMEs appears as a marginal activity performed mainly by managers and specialist mobile workers

Entrance to and advancement within the Swedish medical labour market for physicians with a medical degree from outside the European Union

Background Many physicians who migrate wish to continue practicing medicine in their destination country. However, they may meet barriers and obstacles that prolong the process of entering and advancing within the destination country’s medical labour market. Migrant physicians’ competences are needed, and if fully utilised, it will be beneficial for them, the patients, the medical workforce, and for society. Aim The aim was to explore the entrance to and the advancement within the Swedish medical labour market for physicians with a medical degree from outside of the EU/EEA. Method The study participants were mainly physicians who had enrolled in a complementary programme for physicians with a medical degree from outside the EU/EEA and Switzerland. Both qualitative and quantitative methods were used. Study I included semi-structured interviews with 24 physicians. Study II was a cross-sectional study that included questionnaire data from 283 respondents. Study III included test data from physicians with a medical degree from outside the EU/EEA who had taken a licensing exam 2013–2019 (n = 564), and 14 semi-structured interviews. Study IV included questionnaire data from 101 respondents, and four semi-structured interviews. Interview transcripts and questionnaire free-text answers were thematically analysed. For Study II, the statistical data were descriptively analysed. For Study III, linear and logistic regression analysis were used. In Study IV, descriptive and inferential statistical analyses were performed on the data. To understand and discuss how MPs enter and advance within the medical labour market in Sweden, Bourdieu’s concepts of the social field, symbolic capital and doxa were used as a lens. As a complement to Bourdieu’s theory, self-determination theory (SDT) was used. Results In Study I, several conceptions about working in rural and remote areas in Sweden were identified. These regarded the themes finding work, work content and tasks, and living. Conceptions about working in a certain type of area gave rise to conceptions about what it would be like to live in the same area. The participants’ conceptions derived from their own and from others’ experiences; and conceptions influenced study participants’ motivation of where to work, negatively or positively. In Study II, 88% of the respondents held a position as a physician when answering the questionnaire, but they were in varying stages of their careers from one another; as they also had begun the complementary programme at different times. The respondents had mainly found their first job after the programme via spontaneous job applications, during internships or via friends or other programme participants. Barriers and facilitating aspects as well as the different strategies they used were explored. During their job-seeking process, the respondents reported experiencing discrimination or having their competences undervalued. To increase job prospects, the respondents had, for example, worked as assistant nurses or medical assistants before beginning the complementary programme. Respondents had developed their language by using different resources. Due to high labour market conditions, respondents had moved or changed specialty to increase job prospects. Study III revealed that age was a predictor for succeeding on the licensing exam, and that the complementary programme seemed to reduce the negative age effect for participants aged 45 years or older. In the qualitative material, perceived influential aspects for succeeding or failing on the exam related to the two themes preparations and biographical aspects, and to the exam and exam situation. Study IV explored aspects that influenced choices of employment and specialty, and found that the most important aspects related to choosing employment were the ability to combine work with family, and possibilities for developing competences. The majority of the respondents had specialised in general medicine, and women were more likely to specialise in general medicine than men. Influencers on the interviewees’ motivation and choice to specialise in general medicine related to the themes of job opportunities, positive experiences from PHC, working conditions and family conditions. Conclusions Barriers and limiting circumstances may derive from the micro and meso levels, and influence on a micro level; however, individuals still have agency. They can influence their paths to the labour market and advance within it through certain strategies and/or facilitating aspects. Many barriers and facilitating aspects corresponded to one another and were two sides of the same proverbial coin. The social context and environment influenced the study participants’ choices regarding where to work and in which specialty. Aspects relating to work life and private life collaborated to influence motivation and choices. As a group, these MPs could be interpreted as being hierarchically positioned lower in the Swedish medical field than physicians who trained in the country. However, on an individual level, this may not hold true, as the group is heterogeneous in terms of gender, ethnicity, country of origin, country for medical education, and age. Influential aspects on the macro, meso and micro levels may change over time

Outcomes and risk score for distal pancreatectomy with celiac axis resection (DP-CAR) : an international multicenter analysis

Background: Distal pancreatectomy with celiac axis resection (DP-CAR) is a treatment option for selected patients with pancreatic cancer involving the celiac axis. A recent multicenter European study reported a 90-day mortality rate of 16%, highlighting the importance of patient selection. The authors constructed a risk score to predict 90-day mortality and assessed oncologic outcomes. Methods: This multicenter retrospective cohort study investigated patients undergoing DP-CAR at 20 European centers from 12 countries (model design 2000-2016) and three very-high-volume international centers in the United States and Japan (model validation 2004-2017). The area under receiver operator curve (AUC) and calibration plots were used for validation of the 90-day mortality risk model. Secondary outcomes included resection margin status, adjuvant therapy, and survival. Results: For 191 DP-CAR patients, the 90-day mortality rate was 5.5% (95 confidence interval [CI], 2.2-11%) at 5 high-volume (1 DP-CAR/year) and 18% (95 CI, 9-30%) at 18 low-volume DP-CAR centers (P=0.015). A risk score with age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) score, multivisceral resection, open versus minimally invasive surgery, and low- versus high-volume center performed well in both the design and validation cohorts (AUC, 0.79 vs 0.74; P=0.642). For 174 patients with pancreatic ductal adenocarcinoma, the R0 resection rate was 60%, neoadjuvant and adjuvant therapies were applied for respectively 69% and 67% of the patients, and the median overall survival period was 19months (95 CI, 15-25months). Conclusions: When performed for selected patients at high-volume centers, DP-CAR is associated with acceptable 90-day mortality and overall survival. The authors propose a 90-day mortality risk score to improve patient selection and outcomes, with DP-CAR volume as the dominant predictor

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This study evaluates the out-of-sample forecasting performance of different volatility mod- els. When applied to XACT OMXS30, we use GARCH(1,1), EGARCH(1,1), and t- GAS(1,1) to forecast squared daily returns while Realized GARCH(1,1) and HAR-RV are used to forecast Realized Variance. We forecast both measures with open-close as well as close-close data. One-day-ahead forecasts are computed using a five year mov- ing window. The performance is measured with two different loss functions, MSE and QLIKE. The Diebold-Mariano test is then used to test significance. Our findings indicate that EGARCH(1,1) is superior when forecasting squared daily returns and that HAR-RV is superior when forecasting Realized Variance. Comparing EGARCH and HAR-RV, we find that the latter is more accurate for a symmetrical loss function while EGARCH is superior using the QLIKE loss function. We find no evidence indicating that Student’s t-distribution for the conditional volatility improves forecasting accuracy. Finally, we con- clude that open-close data generates smaller forecast errors than close-close data

Standardization of Environmental Management and Sustainability Reporting

Abstract Title Standardization of Environmental Management and Sustainability Reporting Seminar Date May 29th 2013 Course BUSN68 Degree Project - Accounting and Management Control; BUSN69 Degree Project - Accounting and Auditing, 15 ECTS Authors Johanna Geijer and Linda Sturesson Advisors Per Magnus Andersson and Stefan Yard Keywords Standardization, Environmental Management, Sustainability Reporting, ISO 14001, GRI Purpose The purpose of this thesis is to increase the understanding of why companies choose to standardize environmental management and sustainability reporting instead of using a unique solution. Theoretical Framework The presented theoretical framework of this thesis built on exogenous and endogenous theories consisting of legitimacy theory, stakeholder theory, institutional theory, the resource based view and positive accounting theory. Besides this benefits and implications of standardization will be given account for. Methodology The methodology undertaken is generally based on a qualitative research approach through case studies. A quantitative approach will also be used for the conducted pilot survey and information found in sustainability reports. Complementary to this an expert interview has also been completed. Empirical Foundation The empirical findings imply that the mostly used strategy amongst the investigated corporations is the use of both ISO 14001 and GRI. Such well-established standards also seem to create a foundation for continuous improvements within corporations. Case studies furthermore highlight requirements from customers, investors and owners as an important factor. Conclusions This study indicates that corporations choose to standardize their environmental management and sustainability reporting in search of legitimacy and because of stakeholder demands. Furthermore standards can also become normative making them essential for economic survival. Benefits such as improved comparability and efficiency as well as increased awareness also influence corporations to standardize this area. The study also confirmed that purchase and certification costs of standard deter marginal users to standardize

Risk Analysis of Equity-Bond Portfolios with Default-Driven Stock Price Jumps

MSc in FinanceIn this thesis, we study the risk of a portfolio consisting of stocks and bonds, where bond defaults trigger downward jumps in stock prices. To evaluate the portfolio’s risk exposure, we use Value-at-Risk (VaR) as the primary risk measure. The analysis focuses on a portfolio where the stocks are assumed to be large and homogeneous, and the bond holdings may include any number of defaultable bonds, provided they are exchangeable. The modeling framework is based on the stock-bond setup introduced by Herbertsson (2025b), which explicitly incorporates equity price jumps at bond default events. We extend this framework by analyzing a range of portfolio configurations and testing sensitivity to different asset correlation structures. Default probabilities are estimated using the saddlepoint approximation derived in Herbertsson (2023). To model dependence between bond defaults, we apply both the one-factor Gaussian copula and the Clayton copula, offering flexibility in capturing joint default behavior. Our results show that a stock-bond portfolio with stocks following the model in Herbertsson (2025b) yields substantially higher VaR estimates compared to the case where stocks follow the classical Black and Scholes (1973) model. We also demonstrate that VaR is highly sensitive to the choice of copula parameters, and that increasing the portfolio’s stock allocation generally results in higher risk levels