An investigation of splanchnic blood flow in patients with colorectal cancer

Colorectal cancer is one of the most common forms of cancers worldwide and the second most common cause of cancer death in the European Union. Surgical resection of the tumour is the primary choice of treatment as it is the only option that offers a chance of permanent cure. However, approximately half the patients who undergo apparently curative surgery will die within five years. It has been shown that up to 30% of patients undergoing apparently curative surgery for colorectal cancer harbour occult liver metastases at the time of presentation and it is the presence of these hepatic metastases that determines the likelihood of death from disseminated disease. The liver possesses a dual blood supply, approximately 75% of the blood coming from the portal vein and 25% from the hepatic artery in the normal subject. There is evidence that these proportions are altered shortly after metastatic seeding in the liver. Previous investigations using Doppler ultrasonography have shown that hepatic arterial blood flow is increased in the presence of liver metastases, while some studies suggest that portal venous blood flow is reduced. The Doppler Perfusion Index (DPI), defined as the ratio of hepatic arterial to total liver blood flow, increases as a result of both these changes. An elevated DPI at the time of apparently curative surgery has been shown to be highly predictive of subsequent recurrence in the liver. It is not known, however, whether the DPI is the most effective index for quantifying the tumour-induced changes in liver blood flow. There is also only limited evidence on whether the primary colorectal tumour alters liver blood flow. To address these questions, hepatic arterial and portal venous blood flow were measured in a series of patients with colorectal liver metastases and normal control subjects. There was no significant difference in either component of liver blood flow between metastases patients with and without a primary or recurrent colorectal tumour. This confirms previous reports that the presence of a synchronous primary does not affect metastases driven blood flow changes. Hepatic arterial flow was increased in patients with liver metastases relative to controls, and portal venous flow was reduced. However, the latter difference was attributable to age mismatching, as portal venous blood flow was found to decline significantly with increasing age. An optimised index, the Dual Flow Index (DFI), was developed by logistic regression analysis to distinguish between metastases and control patients on the basis of the blood flow measurements. This was found to only marginally improve on the DPI in accuracy of discrimination (84% vs. 82% after age adjustment of blood flow). It was concluded that the DPI was close to optimal as a diagnostic index, but that the age-dependence of blood flow should be considered in clinical practice. Doppler ultrasonography is recognised to be an operator-dependent technique, and this may account for conflicting reports in the literature about the blood flow changes associated with liver metastases. It has been suggested that functional Computed Tomography (CT) may provide equivalent information about liver blood flow in a less operator-dependent manner. However, reports on the effectiveness of functional computed tomography in detecting liver metastases are conflicting. Dual-phase contrast-enhanced spiral CT scans were used to assess the varying parameters of tumour-induced changes in liver blood flow. Abdominal scans were performed in patients with liver metastases, colorectal cancer patients without overt metastatic disease, and patients with small benign hepatic haemangiomas. No significant differences were found between these patient groups after adjustment for age imbalances. It was concluded that too many variables affect CT parameters in the routine clinical scanning procedure employed in this and other reported studies for them to be useful for studying blood flow changes. Further work is required in this area using a disease-free normal control population, however Doppler ultrasound currently remains the method of choice for the non-invasive assessment of splanchnic blood flow. (Abstract shortened by ProQuest.)

The Impact of Domestic Violence in the Workplace: Results from a Pan-Canadian Survey

When workers experience domestic violence (DV) at home, impacts are felt in the workplace; however, little research is available on this topic. Methods: We conducted an online survey regarding the impacts of DV at work. Results: A total of 8429 people completed the survey. More than a third of respondents reported experiencing DV; among them, more than a third reported that DV affected their ability to get to work, and more than half reported that it continued at or near work. Most reported that DV negatively affected their performance. Almost all respondents, regardless of DV experience, believed that it impacts victims\u27 work lives. Conclusions: This research identifies the scope and impact of DV on workers and workplaces. The data should assist governments, unions, and employers to enact and evaluate proactive practices to address the impact of DV in the workplace

Dynamic p-enrichment schemes for multicomponent reactive flows

We present a family of p-enrichment schemes. These schemes may be separated into two basic classes: the first, called \emph{fixed tolerance schemes}, rely on setting global scalar tolerances on the local regularity of the solution, and the second, called \emph{dioristic schemes}, rely on time-evolving bounds on the local variation in the solution. Each class of $p$-enrichment scheme is further divided into two basic types. The first type (the Type I schemes) enrich along lines of maximal variation, striving to enhance stable solutions in "areas of highest interest." The second type (the Type II schemes) enrich along lines of maximal regularity in order to maximize the stability of the enrichment process. Each of these schemes are tested over a pair of model problems arising in coastal hydrology. The first is a contaminant transport model, which addresses a declinature problem for a contaminant plume with respect to a bay inlet setting. The second is a multicomponent chemically reactive flow model of estuary eutrophication arising in the Gulf of Mexico.Comment: 29 pages, 7 figures, 3 table

Drowsy and dangerous? Fatigue in paramedics: an overview

BackgroundFatigue is a complex phenomenon that has effects on physical characteristics, cognition, behaviours, and physical and mental health. Paramedicine crosses the boundaries of many high-risk industries, namely medicine, transport and aviation. The effects of fatigue on paramedics thus need to be explored and considered in order to begin to identify appropriate interventions and management strategies.AimThe aim of this article was to provide an overview of fatigue in paramedics and its potential effects on various areas of paramedic practice and paramedic health, and to outline potential solutions to assess and manage the risk of fatigue in paramedics as suggested by the literature.MethodsWe conducted unstructured, non-systematic searches of the literature in order to inform an overview of the literature. An overview is a summary of the literature that attempts to survey the literature and describe its characteristics. We thematically structured the review under the following headings: defining occupational activity and health status; clinical performance and patient safety; shift length and time at work; effects on paramedic health; effects on driving abilities; fatigue risk management; and, fatigue proofing.DiscussionFatigue should be considered in the context of overall paramedic health status and paramedic occupational activity. The nature of paramedic shift work, and the associated occupational activity place paramedics at increased risk from fatigue. Shift work may also contribute to sleep disorders among paramedics. Fatigue is associated with increased errors and adverse events, increased chronic disease and injury rates, depression and anxiety, and impaired driving ability.ConclusionThe issue of fatigue in paramedicine is complex and has serious consequences for patients and paramedics. Paramedic services and paramedics need to work collaboratively to identify and action appropriate measures to reduce the effects of fatigue on the wellbeing of the workforce and mitigate its effects on clinical performance and safety

A Neutral Polyampholyte in an ionic solution

The behavior of a neutral polyampholyte ($PA$) chain with $N$ monomers, in an ionic solution, is analyzed in the framework of the full Debye-H$\ddot u$ckel-Bjerrum-Flory $(DHBjF)$ theory. A $PA$ chain, that in addition to the neutral monomers, also contains an equal number of positively and negatively charged monomers, is dissolved in an ionic solution. For \underline{high} concentrations of salt and at high temperatures, the $PA$ exists in an extended state. As the temperature is decreased, the electrostatic energy becomes more relevant and at a $T=T_{\theta}$ the system collapses into a dilute globular state, or microelectrolyte. This state contains a concentration of salt higher than the surrounding medium. As the temperature is decreased even further, association between the monomers of the polymer and the ions of the salt becomes relevant and there is a crossover from this globular state to a low temperature extended state. For \underline{low} densities of salt, the system is collapsed for almost all temperatures and exhibits a first-order phase transition to an extended state at an unphysical low temperature.Comment: 10 pages, Revtex with epsf, 9 Postscript figures. Submitted to PR

Waveguide-integrated silicon T centres

The performance of modular, networked quantum technologies will be strongly dependent upon the quality of their quantum light-matter interconnects. Solid-state colour centres, and in particular T centres in silicon, offer competitive technological and commercial advantages as the basis for quantum networking technologies and distributed quantum computing. These newly rediscovered silicon defects offer direct telecommunications-band photonic emission, long-lived electron and nuclear spin qubits, and proven native integration into industry-standard, CMOS-compatible, silicon-on-insulator (SOI) photonic chips at scale. Here we demonstrate further levels of integration by characterizing T centre spin ensembles in single-mode waveguides in SOI. In addition to measuring long spin T_1 times, we report on the integrated centres' optical properties. We find that the narrow homogeneous linewidth of these waveguide-integrated emitters is already sufficiently low to predict the future success of remote spin-entangling protocols with only modest cavity Purcell enhancements. We show that further improvements may still be possible by measuring nearly lifetime-limited homogeneous linewidths in isotopically pure bulk crystals. In each case the measured linewidths are more than an order of magnitude lower than previously reported and further support the view that high-performance, large-scale distributed quantum technologies based upon T centres in silicon may be attainable in the near term

The school environment and adolescent physical activity and sedentary behaviour : A mixed-studies systematic review

There is increasing academic and policy interest in interventions aiming to promote young people's health by ensuring that the school environment supports healthy behaviours. The purpose of this review was to summarize the current evidence on school-based policy, physical and social-environmental influences on adolescent physical activity and sedentary behaviour. Electronic databases were searched to identify studies that (1) involved healthy adolescents (11-18years old), (2) investigated school-environmental influences and (3) reported a physical activity and/or sedentary behaviour outcome or theme. Findings were synthesized using a non-quantitative synthesis and thematic analysis. Ninety-three papers of mixed methodological quality were included. A range of school-based policy (e.g. break time length), physical (e.g. facilities) and social-environmental (e.g. teacher behaviours) factors were associated with adolescent physical activity, with limited research on sedentary behaviour. The mixed-studies synthesis revealed the importance of specific activity settings (type and location) and intramural sport opportunities for all students. Important physical education-related factors were a mastery-oriented motivational climate and autonomy supportive teaching behaviours. Qualitative evidence highlighted the influence of the wider school climate and shed light on complexities of the associations observed in the quantitative literature. This review identifies future research needs and discusses potential intervention approaches to be considered

Synthesis of Biobased Diethyl Terephthalate via Diels-Alder Addition of Ethylene to 2,5-Furandicarboxylic Acid Diethyl Ester: An Alternative Route to 100% Biobased Poly(ethylene terephthalate)

Poly(ethylene terephthalate) (PET) is a ubiquitous thermoplastic currently produced from nonrenewable fossil resources; as such, sustainable biobased routes to the key terephthalate monomer are being widely pursued. Herein is demonstrated a greener solventless route to biobased diethyl terephthalate via a one-pot heterogeneous Lewis acid catalyzed Diels-Alder addition and dehydration of 2,5-furandicarboxylic acid diethyl ester with ethylene, giving yields of terephthalate up to 59% for the key Diels-Alder addition step. A metrics-based comparison against alternative published biobased routes (available from sugars, cellulose and hemicellulose) shows that the clean synthetic pathway developed herein gives a practical atom economy, overall yield and selectivity, making it a viable alternative to routes currently under development