Studies towards automated ovulation prediction in the pig industry: an electrochemical immunosensor for oestradiol in saliva [poster presentation]

Accurate ovulation prediction in pigs could lead to considerable reduction in losses incurred through failed artificial insemination, poorly controlled litter sizes and unnecessary culling of inaccurately diagnosed "barren" sows. The aim of this work is to predict the onset of oestrus in pigs by monitoring oestradiol levels in saliva. An automated method is proposed, for use outside the laboratory, based on single-use screen-printed electrochemical immunosensors. This approach follows on from previous work by the same authors towards an automated electrochemical progesterone monitor. This paper will describe the preparation of oestradiol sensors by immobilisation of monoclonal antibody onto the carbon electrode surface. Use of the sensors will be described in a competitive immunoassay format, where oestradiol (in buffer or saliva) competes against alkaline-phosphatase-labelled antigen for surface binding. Introduction of the enzyme substrate 1-naphthyl phosphate results in hydrolisis to produce the electrochemically active product, 1-naphthol. Electrochemical oxidation of 1-naphthol, measured amperometrically at an applied potential of +300 mv vs Ag/AgCl, produces a current response which can be used to quantify the oestradiol by use of a calibration plot. The approach used to obtain saliva samples and to achieve an automated system capable of measuring down to picogram/ml levels of oestradiol will be discussed

Endovascular exclusion of iliac artery to iliac vein fistula after lumbar disk surgery

AbstractIliac arteriovenous (AV) fistula is rare after lumbar disk surgery. Traditionally, open repair through the arterial lumen was performed. We report endovascular exclusion of an iliac AV fistula in a 41-year-old woman 8 years after lumbar diskectomy. An angiogram showed an AV fistula connecting the right common iliac artery and vein. This was repaired with placement of two covered wall stents in the right common artery and external iliac artery, and embolization of the right internal iliac artery. Contrast medium-enhanced computed tomography scan at 5 months confirmed elimination of the AV fistula and right iliac artery patency. This technique should be considered in management of iliac AV fistulas. (J Vasc Surg 2003;37:1091-3.

An introduction to neonatal EEG

Electroencephalography (EEG) is used in neonatal care to assess encephalopathy, seizure recognition and classification, to make epilepsy syndrome diagnoses and to assess the maturity of neonatal brain activity. A basic understanding of the EEG is very helpful in ensuring that clinicians gain as much information as possible from this helpful, non-invasive investigation. The neonatal EEG is complex and accurate reporting requires detailed clinical information to be provided on request forms. Even when this is provided EEG reports are frequently returned to the neonatal unit loaded with technical details, making it difficult for neonatal staff to fully understand them. This article reviews the basics of EEG, the changes seen with increasing gestational age, and changes seen in common pathologies. We also provide a structured approach to the interpretation of the neonatal EEG report, and discuss its role in prognostication. Amplitude integrated EEG is reviewed in our companion paper

The pressure of QCD at finite temperatures and chemical potentials

The perturbative expansion of the pressure of hot QCD is computed here to order g^6ln(g) in the presence of finite quark chemical potentials. In this process all two- and three-loop one-particle irreducible vacuum diagrams of the theory are evaluated at arbitrary T and mu, and these results are then used to analytically verify the outcome of an old order g^4 calculation of Freedman and McLerran for the zero-temperature pressure. The results for the pressure and the different quark number susceptibilities at high T are compared with recent lattice simulations showing excellent agreement especially for the chemical potential dependent part of the pressure.Comment: 35 pages, 6 figures; text revised, one figure replace

Development of a novel dual-enzyme screen-printed amperometric biosensor for the analysis of esterified fatty acids

This paper describes, for the first time, the development of a novel trilinolein biosensor based on the immobilisation of lipase and lipoxygenase (LOX) onto a cobalt phthalocyanine screen-printed carbon electrode (CoPC-SPCE) in conjunction with amperometry in stirred solution. The combination of enzymes, integrated into the novel biosensor, provide a selective response for polyunsaturated fatty acid (PUFA) triglycerides, in the presence of both monounsaturated (MUFA) and saturated fatty acid (SFA) triglycerides. The linear range of the trilinolein biosensor is 0.2–10 µM, and the detection limit is 45.5 nM. The biosensor was successfully applied to the measurement of trilinolein present in a pharmaceutical food supplement. The percentage recovery was 86% and the coefficient of variation of the biosensor response was 5.05%. This novel LOX-lipase biosensor is simple to manufacture for trilinolein analysis and has advantages of low cost, speed of analysis and ease of operation, thus making it commercially attractive for a range of applications including food and clinical samples

Multidimensional collaboration; reflections on action research in a clinical context

This paper reflects on the challenges and benefits of multidimensional collaboration in an action research study to evaluate and improve preoperative education for patients awaiting colorectal surgery. Three cycles of planning, acting,observing and reflecting were designed to evaluate practice and implement change in this interactive setting, calling for specific and distinct collaborations. Data collection includes: observing educational interactions; administering patient evaluation questionnaires; interviewing healthcare staff, patients and carers; patient and carer focus groups; and examining written and audiovisual educational materials. The study revolves around and depends on multi-dimensional collaborations. Reflecting on these collaborations highlights the diversity of perspectives held by all those engaged in the study and enhances the action research lessons. Successfully maintaining the collaborations recognises the need for negotiation, inclusivity, comprehension, brokerage,and problem-solving. Managing the potential tensions is crucial to the successful implementation of changes introduced to practice and thus has important implications for patients’ well-being. This paper describes the experiences from an action research project involving new and specific collaborations, focusing on a particular healthcare setting. It exemplifies the challenges of the collaborative action research process and examines how both researchers and practitioners might reflect on the translation of theory into educational practices within a hospital colorectal department. Despite its context-specific features, the reflections on the types of challenges faced and lessons learned provide implications for action researchers in diverse healthcare settings across the world

Quark number susceptibilities of hot QCD up to g^6ln(g)

The pressure of hot QCD has recently been determined to the last perturbatively computable order g^6 ln(g) by Kajantie et al. using three-dimensional effective theories. A similar method is applied here to the pressure in the presence of small but non-vanishing quark chemical potentials, and the result is used to derive the quark number susceptibilities in the limit mu = 0. The diagonal quark number susceptibility of QCD with n_f flavours of massless quarks is evaluated to order g^6ln(g) and compared with recent lattice simulations. It is observed that the results qualitatively resemble the lattice ones, and that when combined with the fully perturbative but yet undetermined g^6 term they may well explain the behaviour of the lattice data for a wide range of temperatures.Comment: 11 pages, 3 figures Typos corrected, references added, figures modifie

Some properties of the newly observed X(1835) state at BES

Recently the BES collaboration has announced observation of a resonant state in the $\pi^+\pi^- \eta'$ spectrum in $J/\psi \to \gamma \pi^+\pi^-\eta'$ decay. Fitting the data with a $0^{-+}$ state, the mass is determined to be 1833.7 MeV with $7.7\sigma$ statistic significance. This state is consistent with the one extracted from previously reported $p \bar p$ threshold enhancement data in $J/\psi \to \gamma p \bar p$. We study the properties of this state using QCD anomaly and QCD sum rules assuming X(1835) to be a pseudoscalar and show that it is consistent with data. We find that this state has a sizeable matrix element $$ leading to branching ratios of $(2.61\sim 7.37)\times 10^{-3}$ and $(2.21\sim 10.61)\times 10^{-2}$ for $J/\psi \to \gamma G_p$ and for $G_p \to \pi^+\pi^- \eta'$, respectively. Combining the calculated branching ratio of $J/\psi \to \gamma G_p$ and data on threshold enhancement in $J/\psi \to \gamma p \bar p$, we determine the coupling for $G_p- p-\bar p$ interaction. We finally study branching ratios of other $J/\psi \to \gamma + {three mesons}$ decay modes. We find that $J/\psi \to \gamma G_p \to \gamma (\pi^+\pi^- \eta, K K \pi^0)$ can provide useful tests for the mechanism proposed.Comment: 13 pages, 3 figures. The final version to appear at EPJ

Perturbative QCD at non-zero chemical potential: Comparison with the large-Nf limit and apparent convergence

The perturbative three-loop result for the thermodynamic potential of QCD at finite temperature and chemical potential as obtained in the framework of dimensional reduction is compared with the exact result in the limit of large flavor number. The apparent convergence of the former as well as possibilities for optimization are investigated. Corresponding optimized results for full QCD are given for the case of two massless quark flavors.Comment: REVTEX4, 4 pages, 3 color figures. v2: fig. 3 now includes also lattice data for two-flavor QCD at nonzero chemical potentia