Field-induced vortex-like textures as a probe of the critical line in reentrant spin glasses

We study the evolution of the low-temperature field-induced magnetic defects observed under an applied magnetic field in a series of frustrated amorphous ferromagnets (Fe\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{1-x}$$\end{document}1-xMn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{x}$$\end{document}x)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{75}$$\end{document}75P\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{16}$$\end{document}16B\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{3}$$\end{document}3Al\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{3}$$\end{document}3 (“a-Fe\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{1-x}$$\end{document}1-xMn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{x}$$\end{document}x”). Combining small-angle neutron scattering and Monte Carlo simulations, we show that the morphology of these defects resemble that of quasi-bidimensional spin vortices. They are observed in the so-called “reentrant” spin-glass (RSG) phase, up to the critical concentration \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x_{\mathrm{C}} \approx 0.36$$\end{document}xC≈0.36 which separates the RSG and “true” spin glass (SG) within the low temperature part of the magnetic phase diagram of a-Fe_1−xMn_x. These textures systematically decrease in size with increasing magnetic field or decreasing the average exchange interaction, and they finally disappear in the SG sample (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x = 0.41$$\end{document}x=0.41), being replaced by field-induced correlations over finite length scales. We argue that the study of these nanoscopic defects could be used to probe the critical line between the RSG and SG phases.

Furnace for in situ and simultaneous studies of nano-precipitates and phase transformations in steels by SANS and neutron diffraction

Interphase precipitation occurring during solid-state phase transformations in micro-alloyed steels is generally studied through transmission electron microscopy, atom probe tomography, and ex situ measurements of Small-Angle Neutron Scattering (SANS). The advantage of SANS over the other two characterization techniques is that SANS allows for the quantitative determination of size distribution, volume fraction, and number density of a statistically significant number of precipitates within the resulting matrix at room temperature. However, the performance of ex situ SANS measurements alone does not provide information regarding the probable correlation between interphase precipitation and phase transformations. This limitation makes it necessary to perform in situ and simultaneous studies on precipitation and phase transformations in order to gain an in-depth understanding of the nucleation and growth of precipitates in relation to the evolution of austenite decomposition at high temperatures. A furnace is, thus, designed and developed for such in situ studies in which SANS measurements can be simultaneously performed with neutron diffraction measurements during the application of high-temperature thermal treatments. The furnace is capable of carrying out thermal treatments involving fast heating and cooling as well as high operation temperatures (up to 1200 °C) for a long period of time with accurate temperature control in a protective atmosphere and in a magnetic field of up to 1.5 T. The characteristics of this furnace give the possibility of developing new research studies for better insight of the relationship between phase transformations and precipitation kinetics in steels and also in other types of materials containing nano-scale microstructural features.

P2551A randomized, pharmacodynamic comparison of low dose ticagrelor (60mg bid) to low dose prasugrel (5mg od) in patients with prior myocardial infarction: the ALTIC-2 study

Background

In patients with prior myocardial infarction (MI) and features of high ischemic and low bleeding risk, extending dual antiplatelet therapy beyond 1 year or reinitiating treatment is reasonable. A lower than the standard dose, namely ticagrelor 60mg bid instead of 90mg bid and prasugrel 5mg od instead of 10mg od, may be associated with reduced bleeding risk. In the Patients with Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin–Thrombolysis in Myocardial Infarction 54 (PEGASUS-TIMI 54) trial, ticagrelor 60mg bid reduced the ischemic events, at the cost of increased bleeding events. There is no data on the pharmacodynamic efficacy of ticagrelor 60mg bid over low dose prasugrel (5mg od).

Purpose

To compare platelet reactivity (PR) between prasugrel 5mg od and ticagrelor 60 mg bid in the chronic phase of stable post-MI patients.

Methods

The ALTIC-2 was a prospective, single-center, randomized, crossover study involving patients on aspirin 100mg od and PEGASUS-TIMI 54 characteristics: >50 years old with MI 1–3 years earlier and at least one high risk feature (age >65 years, diabetes mellitus, a second MI, multivessel disease, or renal dysfunction). After a 14-day washout period–if on P2Y12 receptor antagonist therapy-, patients were randomized to either ticagrelor 60mg bid or prasugrel 5mg od for 14 days, with a crossover directly to the alternate treatment for another 14 days. PR was assessed by the VerifyNow P2Y12 reaction assay in PRU at baseline, pre and post-crossover, 2 hours post last study-drug dose. Statistical analysis was performed with STATA13.0.

Results

We recruited 20 eligible patients (80% men, 40% diabetics, 65% smokers, 70% multivessel disease, with a mean age of 64.8±6.3 years) for participation in the study (10 in each treatment sequence). During pre-crossover period, in the group allocated first in prasugrel PR levels (mean ± standard deviation) decreased from 238.4±50 to 128±47 (p<0.0001), while in the group allocated first in ticagrelor levels of PR decreased from 259.6±36 to 30.8±29 (p<0.0001). At the end of the 2 treatments, PR levels decreased to 33±26 in the group allocated first in prasugrel (p=0.0001), while in the group allocated first in ticagrelor levels of PR increased to 136±61 (p=0.0001). Analysis of combined data of PR levels (pre- and post-crossover, primary endpoint) adjusted for baseline values and age showed a difference of PR levels (β: −103, 95% CI: −120 to −85) in favor of ticagrelor. A non-significant period effect was observed and no carry effect was found. The secondary endpoint of high PR (>208 PRU) rate was 0% for ticagrelor and 5.0% for prasugrel. No patient exhibited a major bleeding event at either treatment group.

Conclusions

In patients with previous MI and at least one other high-risk feature, low dose of ticagrelor results in a significantly lower PR compared to prasugrel 5mg od.

Acknowledgement/Funding

National and Kapodistrian University of Athens

Astringency estimation of wines maturing in different types of containers

Astringency is a parameter of great importance for wine quality. During wine maturation in wooden barrels it can be enhanced by tannins extracted by the wood. However, their concentration is not directly correlated with astringency. Mean Degree of Polymerization (mDP) is often employed to characterize the structural characteristics of tannins in wines, providing also information on their proanthocyanidin content. The prodelphinidin content (%P), as well as the percentage of epigallocatechin (EGC) in extension and terminal units, have been negatively linked with astringency. Since the intensity of astringency is a decisive factor for the quality of a barrel-aged wine in this experiment, the structural characteristics of wine proanthocyanidins were determined in four different Greek wines, two white (Vilana and Dafni) and two red (Kotsifali and Mandilari). All wines matured for nine months in different types of containers (stainless steel tanks and barrels made of different woods). The prodelphinidin (terminal or extension) content was determined by means of phloroglucinolysis, followed by HPLC-UV-MS analysis, while astringency was assessed by a panel of trained tasters. Multivariate analysis showed that only white wines that matured in Acacia barrels contained high %P values independently of the variety used and were characterized as less astringent by the panel. Moreover, the determination of %extension and terminal EGC units revealed that the tannins of the wines maturing in Acacia barrels, contain higher amounts of EGC as terminal units. These findings could be used by winemakers in order to select the appropriate type of barrel according to the type of wine.

Keywords: Astringency, proanthocyanidin, tannin, barrel

Cardiological Database Management System as a Mediator to Clinical Decision Support

An object-oriented medical database management system is presented for a typical cardiologic center, facilitating epidemiological trials. Object-oriented analysis and design were used for the system design, offering advantages for the integrity and extendibility of medical information systems. The system was developed using object-oriented design and programming methodology, the C++ language and the Borland Paradox Relational Data Base Management System on an MS-Windows NT environment. Particular attention was paid to system compatibility, portability, the ease of use, and the suitable design of the patient record so as to support the decisions of medical personnel in cardiovascular centers. The system was designed to accept complex, heterogeneous, distributed data in various formats and from different kinds of examinations such as Holter, Doppler and electrocardiography.

Red Wine Age Estimation by the Alteration of Its Color Parameters: Fourier Transform Infrared Spectroscopy as a Tool to Monitor Wine Maturation Time

Color, phenolic content, and chemical age values of red wines made from Cretan grape varieties (Kotsifali, Mandilari) were evaluated over nine months of maturation in different containers for two vintages. The wines differed greatly on their anthocyanin profiles. Mid-IR spectra were also recorded with the use of a Fourier Transform Infrared Spectrophotometer in ZnSe disk mode. Analysis of Variance was used to explore the parameter's dependency on time. Determination models were developed for the chemical age indexes using Partial Least Squares (PLS) (TQ Analyst software) considering the spectral region 1830-1500 cm^-1. The correlation coefficients (r) for chemical age index i were 0.86 for Kotsifali (Root Mean Square Error of Calibration (RMSEC) = 0.067, Root Mean Square Error of Prediction (RMSEP) = 0,115, and Root Mean Square Error of Validation (RMSECV) = 0.164) and 0.90 for Mandilari (RMSEC = 0.050, RMSEP = 0.040, and RMSECV = 0.089). For chemical age index ii the correlation coefficients (r) were 0.86 and 0.97 for Kotsifali (RMSEC 0.044, RMSEP = 0.087, and RMSECV = 0.214) and Mandilari (RMSEC = 0.024, RMSEP = 0.033, and RMSECV = 0.078), respectively. The proposed method is simpler, less time consuming, and more economical and does not require chemical reagents.

Magnetic Fluctuations, Precursor Phenomena, and Phase Transition in MnSi under a Magnetic Field

The reference chiral helimagnet MnSi is the first system where Skyrmion lattice correlations have been reported. At a zero magnetic field the transition at T_{C} to the helimagnetic state is of first order. Above T_{C}, in a region dominated by precursor phenomena, neutron scattering shows the buildup of strong chiral fluctuating correlations over the surface of a sphere with radius 2π/ℓ, where ℓ is the pitch of the helix. It has been suggested that these fluctuating correlations drive the helical transition to first order following a scenario proposed by Brazovskii for liquid crystals. We present a comprehensive neutron scattering study under magnetic fields, which provides evidence that this is not the case. The sharp first order transition persists for magnetic fields up to 0.4 T whereas the fluctuating correlations weaken and start to concentrate along the field direction already above 0.2 T. Our results thus disconnect the first order nature of the transition from the precursor fluctuating correlations. They also show no indication for a tricritical point, where the first order transition crosses over to second order with increasing magnetic field. In this light, the nature of the first order helical transition and the precursor phenomena above T_{C}, both of general relevance to chiral magnetism, remain an open question.

Design and performance of a novel neutron powder diffractometer: PEARL at TU Delft

The performance of the new neutron powder diffraction instrument PEARL that is installed at the research reactor of Delft University of Technology is reported. It is based on the optimization concepts developed by Cussen [Nucl. Instrum. Methods Phys. Res. Sect. A (2007), 583, 394–406], which lead to high performance competing with existing constant-wavelength neutron powder diffractometers, despite the relatively low source brightness of the 2 MW reactor of Delft University of Technology.

Differences in cardiac structure assessed by echocardiography between renal transplant recipients and chronic kidney disease patients

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in predialysis chronic kidney disease (CKD) and dialysis patients as well as in renal transplant recipients (RTRs). Left ventricular hypertrophy (LVH) starts early during the course of CKD and is a strong predictor of CVD in this population. Regression of LVH after a successful renal transplantation remains a debatable issue among investigators, whereas there is little data comparing echocardiographic measurements between patients with predialysis CKD and RTRs.

AIM

The aim of this study was to compare echocardiographic measurements of LV structure and function between predialysis CKD patients and RTRs of similar renal function level.

PATIENTS AND METHODS

We conducted a case control study with individual (1:2) matching from the Renal Transplant and the predialysis CKD Outpatient Clinic. For each of the 36 RTRs, two matched for gender, age and estimated glomerular filtration rate (eGFR) predialysis CKD outpatients (72 patients) were included. All patients underwent transthoracic echocardiography and LV mass, LV mass index [LVM and LVMI = LVM/BSA g/m(2)] and indices of systolic function were measured. In a subgroup of 12 RTRs we retrospectively assessed and compared the LVMI measurements at three different time points, during predialysis, dialysis and post transplant period.

RESULTS

The prevalence of LVH was 33% in RTRs and 52% in CKD patients (ns). RTRs had significantly lower LVM and LVMI levels compared with predialysis CKD patients (P = .006 and P = .008) while the other echocardiographic indices did not differ. In the subgroup of 12 RTRs, post-transplant LVMI levels (105 ± 25 g/m(2)) were significantly lower in comparison with predialysis (147 ± 57 g/m(2)) and dialysis LVMI levels (169 ± 72 g/m(2)) (P = .01, P = .01, respectively).

CONCLUSION

RTRs had significantly lower LVMI compared with predialysis CKD patients of similar age, renal function, hemoglobin and blood pressure level.

Assessment of nonimmunologic factors in kidney transplant recipients according to Kidney Disease Improving Global Outcomes

INTRODUCTION

Cardiovascular disease is the primary cause of death among kidney transplant recipients (KTRs), whereas chronic allograft nephropathy (CAN) is the main reason leading to end-stage chronic kidney disease. The etiologies of both entities include immunologic and nonimmunologic factors. The management of modifiable nonimmunologic parameters has recently been identified by the Kidney Disease Improving Global Outcomes (KDIGO) guidelines. The aim of our study was to assess the implementation of these guidelines in the outpatient kidney transplantation clinic of our hospital.

PATIENT AND METHODS

We retrospectively monitored the records of 48 transplanted KTRs including 32 males of overall mean age 45.1 ± 10.7 years regarding control of anemia, dyslipidemia, mineral bone disorder (MBD), and blood pressure (BP) levels. Data were recorded every 6 months for 2 years, starting 1 year after renal transplantation.

RESULTS

The estimated glomerular filtration rate of patients at baseline was 60.3 ± 18.8 mL/min/1.73 m(2) with no significant change during 2 years of follow-up. The control of anemia was satisfactory in 42 patients (88%) with hemoglobin values ≥ 11 g/dL during the follow-up. Regarding dyslipidemia management, the aggregate of patients showed fasting triglycerides ≤500 mg/dL in all measurements. The percentage of KTRs with LDL ≤100 mg/dL tended to improve from baseline versus the end of the study period (20.8% vs 41.7%). Serum calcium was satisfactorily controlled in 77% of patients, serum phosphorus in all patients, whereas parathyroid hormone (PTH) was abnormal in 60% of KTRs with chronic kidney disease stages 3-5. Finally, the BP goal of <130/80 mm Hg was achieved in approximately half of the patients.

CONCLUSION

Control of nonimmunologic factors was satisfactory in terms of renal anemia and MBD, whereas dyslipidemia and BP levels were inadequately controlled. There is a clear need for better integration into clinical practice of KDIGO guidelines with regard to modifiable nonimmunologic factors.

LX1032: A potential new therapy for carcinoid syndrome (CS)

e14555

Background: Patients with metastatic CS experience a variety of symptoms due to increased serotonin (5-HT) produced by metastatic GI tumor cells. The enzyme tryptophan hydroxylase (TPH) catalyzes the rate-limiting step in the synthesis of 5-HT. Reducing 5-HT synthesis by TPH inhibition represents a new mechanism for potentially managing symptoms associated with CS. LX1032 is a novel, orally bioavailable TPH inhibitor designed to afford systemic exposure without affecting 5-HT synthesis in the CNS. Preclinical studies of LX1032 in multiple species confirmed systemic inhibition of 5-HT synthesis without changes in brain 5-HT levels. Methods: Single (n=47 subjects) and multiple (n=40 subjects) ascending dose studies with LX1032 were completed in normal volunteers; 24-hr urinary 5-HIAA and blood 5-HT were measured as biomarkers of 5-HT metabolism. Results: LX1032 produced a significant dose-dependent reduction in urinary 5-HIAA and blood 5-HT levels, with maximal reductions observed at doses at or above 500 mg, once daily, in the 14 day multiple ascending dose (MAD) study; the mean change from baseline in blood 5-HT was -30% for the 1500 mg (500 mg TID) dose group. Single doses up to 500 mg were well tolerated with no evidence of dose limiting toxicity or tolerability; GI related adverse events (nausea, emesis, and diarrhea) started to emerge at the 1,000 mg dose level and became dose-limiting at the 1,500 mg single dose level. Multiple doses were well tolerated at all dose levels up to 1.500 mg (500 mg TID). Adverse events (AEs) were mild to moderate and no serious AEs occurred; a dose-dependent, mild increase in hepatic transaminase levels was observed in the MAD study. Conclusions: Inhibiting TPH, and thereby reducing peripheral 5-HT production, represents a potential new approach for managing symptoms in CS patients. LX1032 is a novel, orally bioavailable TPH inhibitor that significantly reduced 5-HT production at well tolerated dose levels. The favorable safety profile and observed decrease in urinary 5-HIAA and blood 5-HT levels indicate that LX1032 could be used to lower 5-HT as a potential new approach for managing hyperserotoninemia-related complications of CS, and support studies of the compound in CS patients.

[Table: see text]

The public health impact of avian influenza viruses

Influenza viruses with novel hemagglutinin and 1 or more accompanying genes derived from avian influenza viruses sporadically emerge in humans and have the potential to result in a pandemic if the virus causes disease and spreads efficiently in a population that lacks immunity to the novel hemagglutinin. Since 1997, multiple avian influenza virus subtypes have been transmitted directly from domestic poultry to humans and have caused a spectrum of human disease, from asymptomatic to severe and fatal. To assess the pandemic risk that avian influenza viruses pose, we have used multiple strategies to better understand the capacity of avian viruses to infect, cause disease, and transmit among mammals, including humans. Seroepidemiologic studies that evaluate the frequency and risk of human infection with avian influenza viruses in populations with exposure to domestic or wild birds can provide a better understanding of the pandemic potential of avian influenza subtypes. Investigations conducted in Hong Kong following the first H5N1 outbreak in humans in 1997 determined that exposure to poultry in live bird markets was a key risk factor for human disease. Among poultry workers, butchering and exposure to sick poultry were risk factors for antibody to H5 virus, which provided evidence for infection. A second risk assessment tool, the ferret, can be used to evaluate the level of virulence and potential for host-to-host transmission of avian influenza viruses in this naturally susceptible host. Avian viruses isolated from humans exhibit a level of virulence and transmissibility in ferrets that generally reflects that seen in humans. The ferret model thus provides a means to monitor emerging avian influenza viruses for pandemic risk, as well as to evaluate laboratory-generated reassortants and mutants to better understand the molecular basis of influenza virus transmissibility. Taken together, such studies provide valuable information with which we can assess the public health risk of avian influenza viruses.

Chiral paramagnetic skyrmion-like phase in MnSi

We present a comprehensive study of chiral fluctuations in the reference helimagnet MnSi by polarized neutron scattering and neutron spin echo spectroscopy, which reveals the existence of a completely left-handed and dynamically disordered phase. This phase may be identified as a spontaneous Skyrmion phase: it appears in a limited temperature range just above the helical transition T_{C} and coexists with the helical phase at T_{C}.

Generalized spin-glass relaxation

Spin relaxation close to the glass temperature of CuMn and AuFe spin glasses is shown, by neutron spin echo, to follow a generalized exponential function which explicitly introduces hierarchically constrained dynamics and macroscopic interactions. The interaction parameter is directly related to the normalized Tsallis nonextensive entropy parameter q and exhibits universal scaling with reduced temperature. At the glass temperature q=5/3 corresponding, within Tsallis' q statistics, to a mathematically defined critical value for the onset of strong disorder and nonlinear dynamics.

An investigation of flat panel equipment variables on image quality with a dedicated cardiac phantom

Image quality (IQ) evaluation plays a key role in the process of optimization of new x-ray systems. Ideally, this process should be supported by real clinical images, but ethical issues and differences in anatomy and pathology of patients make it impossible. Phantom studies might overcome these issues. This paper presents the IQ evaluation of 30 cineangiographic films acquired with a cardiac flat panel system. The phantom used simulates the anatomy of the heart and allows the circulation of contrast agent boluses through coronary arteries. Variables investigated with influence on IQ and radiation dose are: tube potential, detector dose, added Copper filters, dynamic density optimization (DDO) and viewing angle. The IQ evaluation consisted of scoring 4 simulated calcified lesions located on different coronary artery segments in terms of degree of visualization. Eight cardiologists rated the lesions using a five-point scale ((1) lesion not visible to (5) very good visibility). Radiation doses associated to the angiograms are expressed in terms of incident air kerma (IAK) and effective dose that has been calculated with PCXMX software (STUK, Finland) from the exposure settings assuming a standard sized patient of 70 Kg. Mean IQ scores ranged from 1.68 to 4.88. The highest IQ scores were obtained for the angiograms acquired with tube potential 80 kVp, no added Cu filters, DDO 60%, RAO and LAO views and the highest entrance detector dose that has been used in the present study, namely 0.17 microGy/im. Radiation doses (IAK approximately 40 mGy and effective dose of 1 mSv) were estimated for angiograms acquired at 15 frames s(-1), detector field-of-view 20 cm, and a length of 5 s. The following parameters improved the IQ factor significantly: a change in tube potential from 96 to 80 kVp, detector dose from 0.10 microGy/im to 0.17 microGy/im, the absence of Copper filtration. DDO variable which is a post-processing parameter should be carefully evaluated because it alters the quality of the images independently of radiation exposure settings. The SAM anthropomorphic phantom has the advantage of visualization of stenotic lesions during the injection of a contrast agent and using an anatomical background. In the future, this phantom could potentially bridge the gap between physics tests and the clinical reality in the catheterization laboratory.

An e-learning platform for aerospace medicine

The appeal of online education and distance learning as an educational alternative is ever increasing. To support and accommodate the over-specialized knowledge available by different experts, information technology can be employed to develop virtual distributed pools of autonomous specialized educational modules and provide the mechanisms for retrieving and sharing them. New educational standards such as SCORM and Healthcare LOM enhance this process of sharing by offering qualities like interoperability, accessibility, and reusability, so that learning material remains credible, up-to-date and tracks changes and developments of medical techniques and standards through time. Given that only a few e-learning courses exist in aerospace medicine the material of which may be exchanged among teachers, the aim of this paper is to illustrate the procedure of creating a SCORM compliant course that incorporates notions of recent advances in social web technologies. The course is in accordance with main educational and technological details and is specific to pulmonary disorders in aerospace medicine. As new educational trends place much emphasis in continuing medical education, the expansion of a general practitioner's knowledge in topics such as aviation and aerospace pulmonary disorders for crew and passengers becomes a societal requirement.

Effect of 1- and 10-day administration of tepoxalin on minimum alveolar concentration of isoflurane and sevoflurane in dogs

Analgesics given preoperatively have the potential to decrease the amount of inhalant anesthetics required intraoperatively (i.e., to decrease the minimum alveolar concentration, or MAC, for the inhalant). Tepoxalin is an NSAID approved for the treatment of arthritis in dogs in the United States and, hence, could be administered to patients undergoing anesthesia. In this study, administration of a single dose or a 10-day course of tepoxalin did not affect the MAC for isoflurane or sevoflurane.

Andreas Rett and benign familial neonatal convulsions revisited

In 1964 Andreas Rett published the first account of a family with benign familial neonatal convulsions (BFNC). The authors retraced Rett's family and report that the clinical and genetic features of this original family fit the currently accepted definitions of BFNC. They also consider the career of Dr. Rett, a researcher and social reformer as well as an advocate for the rights of children with developmental disabilities.

Human T-lymphotropic virus type I/II infections in volunteer blood donors from Northern and Western Greece: increased prevalence in one blood bank unit

BACKGROUND: Blood donors are routinely screened for antibodies to human T-cell lymphotropic viruses type I and II (HTLV-I and HTLV-II) in the United States, Canada, Japan, and some European countries. Previous reports from our group in relatively small numbers of donors have shown a zero prevalence of HTLV-I/II markers in our region. In this study, seven blood banks in the north and west of Greece participated in order to determine whether mandatory screening of blood donations for HTLV-I/II infection should be established. METHODS: Sera from 51,714 consecutive donors were investigated for anti-HTLV-I/II using two commercially available enzyme immunoassays (EIAs). Reactive samples in one or both EIAs were repeatedly evaluated further by Western blot, which is specific for both confirmation and differentiation of HTLV-I and HTLV-II seroreactivities. Investigation for HTLV DNA was also done in all EIA-reactive donors, irrespective of the WB result, using a combination assay based on the polymerase chain reaction (PCR) and a DNA EIA. RESULTS: A total of 115 donors (0.222%; 95% CI 0.018-0.26%) were initially considered reactive for anti-HTLV-I/II by EIAs. However, only 7 of the 115 were confirmed as positive by WB (five HTLV-I and two HTLV-I/II). Thus, the prevalence of anti-HTLV-I/II in donors from northern and western Greece was 0.013% (95% CI 0.003-0.023%). Interestingly, the majority of WB-confirmed anti-HTLV-positive individuals were detected in the blood bank of Corfu (5/7, all anti-HTLV-I). This prevalence (5/15383; 0.032%; 95% CI 0.004-0.061%) was six times the prevalence found at the other blood banks combined (2/36331; 0.0055%; 95% CI 0-0.013%), but it was not statistically significant. None of the EIA-reactive donors had detectable HTLV DNA. CONCLUSIONS: The very low prevalence of confirmed anti-HTLV-I/II infection markers in northern and western Greek blood donors, together with the negative PCR results in EIA-reactive subjects, indicates that anti-HTLV-I/I routine screening is not really justified in this area of our country. However, the increased prevalence of WB-confirmed anti-HTLV-I-positive donors in the Corfu blood bank calls for further prospective and careful investigation in order to address whether this finding represents a real cluster phenomenon of HTLV infection.

Estimation of Distance Between a Unipolar Recording Electrode and a Myocardial Bundle Based on Signal Characteristics

The aim of the present paper, is the estimation of the distance between an electrode used as a recording site of the extracellular potential field and a surviving myocardial bundle. The importance of the reliable solution of this problem lies among others in controlling ablation. For our purposes one-dimensional propagation is considered and current sources are activated along a cable simulating the propagating waves with constant velocity. Different models of current sources are explored. By use of these models, the corresponding functions expressing extracellular potentials are calculated, using the volume conductor equation. This way, extracellular potentials are modeled as parametric functions of longitudinal distance, while perpendicular distance, current source strength, and other factors related to the propagated wave are parameters of the functions. Simulated annealing is applied for model parameter estimation and appropriate Time Domain and Wavelet Domain cost functions are investigated. Different combinations of model and cost function are evaluated regarding the accuracy of distance estimation. A continuous source model function with a wavelet cost function was found to be the most accurate combination. The accuracy of distance estimation is related to the selected source model and to the actual distance of recording in a nonmonotonic way.

Effects of delayed (24 h postintervention) β-irradiation therapy after coronary angioplasty and stenting in de novo native coronary artery lesions

BACKGROUND

The effects of brachytherapy performed 24 h postintervention in de novo native coronary artery lesions.

METHODS AND RESULTS

Thirty-nine patients with 39 de novo coronary artery lesions were randomised to prompt (immediately after intervention, n=21) or delayed (24 h later, n=18) beta brachytherapy ((90)Sr/(90)Y) after been successfully revascularized with stenting. Clinical follow-up data up to 21 months (median time) were compared. After irradiation and at 6-month follow-up, paired volumetric analysis of the stented segment and the 5-mm proximal and distal reference segments was performed; this included measurements of the external elastic membrane, lumen, plaque, and media (external elastic membrane minus lumen), stent and intima hyperplasia (stent minus lumen). Baseline clinical and angiographic characteristics were similar in the two groups. Postintervention measurements of stent, lumen, and intima hyperplasia volumes as well as postintervention minimum lumen cross-sectional areas were not different. In the stented segments and in the segments 5 mm proximal and distal to the stent, similar changes of all IVUS measurements were measured in the two patient groups, but in the lumen volume at the proximal stent edge of patients irradiated 24 h postinjury. At 21 months median follow-up time, target lesion revascularization (TLR) was performed in 8 patients (38%) in the prompt irradiation group compared with 3 (17%) in the delayed (P=.17).

CONCLUSION

Beta irradiation is similarly effective whether performed immediately after percutaneous coronary intervention or 24 h later.

Research and education directions in Medical Informatics at the Aristotle University of Thessaloniki

The field of Medical Informatics is one of the most active fields both in research and education at the Aristotle University of Thessaloniki. The nucleus of this scientific field at the Aristotle University resides in the Medical School and in particular in the Laboratory of Medical Informatics. Education programs exist in undergraduate, graduate and post-graduate levels, and are targeted towards medical students and doctors and information technology related students and professionals. Research projects cover a wide area of medical informatics including medical information processing and management, electronic health records design and implementation, medical decision support, biological systems simulation, telemedicine applications, integration and communication issues related to regional health information systems, and quality assessment of health services and systems. The description and brief presentation of the output of these educational and research directions shall be presented in this paper.

Effects of storage conditions and fruit processing on the degradation of parathion methyl on apples and lemons

Degradation of parathion methyl on lemon and apple on the trees, during storage of these fruits in refrigerated rooms, and during juice production was studied. The pesticide was applied to the trees according to the recommended application procedures. Apples and lemons received a single application of parathion methyl at 40 g active ingredient/100 litres. Residues were determined with a simple gas-chromatographic method; the recovery rate of parathion methyl from apples and lemons was 85-108% and the limit of determination was 0.004 mg kg(-1). The half-lives of parathion methyl on the trees were 7 days for apples and 5 days for lemons. The duration of storage of the fruits in a refrigerated room have been largely extended to 65 and 63 days, respectively. The high acidity of lemons was found not to affect the degradation rate of parathion methyl. When fruit juice was produced from both apples and lemons, parathion methyl residues were detected in apple but not in lemon juice.

Mining association rules from clinical databases: an intelligent diagnostic process in healthcare

Data mining is the process of discovering interesting knowledge, such as patterns, associations, changes, anomalies and significant structures, from large amounts of data stored in databases, data warehouses, or other information repositories. Mining Associations is one of the techniques involved in the process mentioned above and used in this paper. Association is the discovery of association relationships or correlations among a set of items. The algorithm that was implemented is a basic algorithm for mining association rules, known as a priori. In Healthcare, association rules are considered to be quite useful as they offer the possibility to conduct intelligent diagnosis and extract invaluable information and build important knowledge bases quickly and automatically. The problem of identifying new, unexpected and interesting patterns in medical databases in general, and diabetic data repositories in specific, is considered in this paper. We have applied the a priori algorithm to a database containing records of diabetic patients and attempted to extract association rules from the stored real parameters. The results indicate that the methodology followed may be of good value to the diagnostic procedure, especially when large data volumes are involved. The followed process and the implemented system offer an efficient and effective tool in the management of diabetes. Their clinical relevance and utility await the results of prospective clinical studies currently under investigation.

Comparison of classical and ultrasound-assisted isolation procedures of cellulose from kenaf (Hibiscus cannabinus L.) and eucalyptus (Eucalyptus rodustrus Sm.)

A comparative study of classical and ultrasound-assisted extraction and purification of cellulose from kenaf (Hibiscus cannabinus L.) and eucalyptus (Eucalyptus rodustrus Sm.), has been conducted. The isolated cellulose samples were studied by diffuse reflectance infrared Fourier transform spectroscopy and 13C nuclear magnetic resonance (13C-NMR) spectroscopy and the crystallinity was also determined. The use of ultrasound decreased the total time of treatment, in addition the purity of the obtained cellulose was very high.

Probing jump diffusion in crystalline solids with neutron spin-echo spectroscopy

Neutron spin-echo spectroscopy has been applied to jump diffusion in a crystalline solid. Definite advantages of spin-echo spectroscopy over quasielastic neutron scattering are the direct visual discrimination of fast and slow diffusion processes and the high resolution in the time-energy domain. The potential of the method is demonstrated by way of Ni diffusion in the intermetallic alloy NiGa.

Identification of uric acid and xanthine oxidase in atherosclerotic plaque

Concentrations of uric acid in carotid endarterectomy specimens in men and women were measured using high-performance liquid chromatography in comparison wo nonatherosclerotic control specimens.

A neural network approach in diabetes management by insulin administration

Diabetes management by insulin administration is based on medical experts' experience, intuition, and expertise. As there is very little information in medical literature concerning practical aspects of this issue, medical experts adopt their own rules for insulin regimen specification and dose adjustment. This paper investigates the application of a neural network approach for the development of a prototype system for knowledge classification in this domain. The system will further facilitate decision making for diabetic patient management by insulin administration. In particular, a generating algorithm for learning arbitrary classification is employed. The factors participating in the decision making were among other diabetes type, patient age, current treatment, glucose profile, physical activity, food intake, and desirable blood glucose control. The resulting system was trained with 100 cases and tested on 100 patient cases. The system proved to be applicable to this particular problem, classifying correctly 92% of the testing cases.