660 research outputs found

    High-quality epitaxial iron nitride films grown by gas-assisted molecular-beam epitaxy

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    Thin films of γ’-Fe4N were grown on polished (001) MgO substrates by molecular-beam epitaxy of iron in the presence of a gas flow from a rf atomic source. By means of x-ray diffraction, Mössbauer Spectroscopy, Rutherford backscattering/channeling, and scanning probe microscopy, it is shown that, with this method, single-phase, high-quality epitaxial thin films can be grown with a very smooth surface (root-mean-square roughness ∼0.4 nm). Magnetic measurements reveal square hysteresis loops, moderate coercivities (45 Oe for a 33 nm thick film) and complete in-plane orientation of the magnetization. These properties make the films interesting candidates for device applications

    The contemporary pulmonary artery catheter. Part 2:measurements, limitations, and clinical applications

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    Nowadays, the classical pulmonary artery catheter (PAC) has an almost 50-year-old history of its clinical use for hemodynamic monitoring. In recent years, the PAC evolved from a device that enabled intermittent cardiac output measurements in combination with static pressures to a monitoring tool that provides continuous data on cardiac output, oxygen supply and-demand balance, as well as right ventricular performance. In this review, which consists of two parts, we will introduce the difference between intermittent pulmonary artery thermodilution using bolus injections, and the contemporary PAC enabling continuous measurements by using a thermal filament which heats up the blood. In this second part, we will discuss in detail the measurements of the contemporary PAC, including continuous cardiac output measurement, right ventricular ejection fraction, end-diastolic volume index, and mixed venous oxygen saturation. Limitations of all of these measurements are highlighted as well. We conclude that thorough understanding of measurements obtained from the PAC is the first step in successful application of the PAC in daily clinical practice

    The contemporary pulmonary artery catheter. Part 1:placement and waveform analysis

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    Nowadays, the classical pulmonary artery catheter (PAC) has an almost 50-year-old history of its clinical use for hemodynamic monitoring. In recent years, the PAC evolved from a device that enabled intermittent cardiac output measurements in combination with static pressures to a monitoring tool that provides continuous data on cardiac output, oxygen supply and-demand balance, as well as right ventricular (RV) performance. In this review, which consists of two parts, we will introduce the difference between intermittent pulmonary artery thermodilution using cold bolus injections, and the contemporary PAC enabling continuous measurements by using a thermal filament which at random heats up the blood. In this first part, the insertion techniques, interpretation of waveforms of the PAC, the interaction of waveforms with the respiratory cycle and airway pressure as well as pitfalls in waveform analysis are discussed. The second part will cover the measurements of the contemporary PAC including measurement of continuous cardiac output, RV ejection fraction, end-diastolic volume index, and mixed venous oxygen saturation. Limitations of all of these measurements will be highlighted there as well. We conclude that thorough understanding of measurements obtained from the PAC are the first step in successful application of the PAC in daily clinical practice

    Quality of primary health care in Poland from the perspective of the physicians providing it

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    Background: Primary care (PC) allows patients to address most of their health needs and is essential for high quality healthcare systems. The aim of the study was to analyze the insight of nine core dimensions of Polish PC system: “Economic conditions”, “Workforce”, “Accessibility”, “Comprehensiveness”, “Continuity”, “Coordination”, “Quality of care”, “Efficiency” and “Equity” and to identify the characteristics of the providing physicians that influence their perception of the quality of care.Methods: A cross-sectional study was conducted as part of an international QUALICOPC project. In Poland a nationally representative sample of 220 PC physicians was selected from the database of Polish National Health Fund by a stratified random sampling procedure. The research tool was a standardized 64-item questionnaire. Each of the respondents’ answers were assigned a numerical value ranging from−1 (extremely negative) to +1 (extremely positive). The quality indicators were calculated as an arithmetic mean of variables representing particular PC dimensions.Results: The mean scores for the majority of the dimensions had negative values. Accessibility of care was perceived as the best dimension, while the economic conditions were evaluated most negatively. Only a small part of variation in quality evaluation could be explained by physicians’ characteristics.Conclusions: The negative evaluation of primary care reflects the growing crisis in the health care system in Poland. There is an urgent need to apply complex recovery measures to improve the quality of primary care

    Disparity between skin perfusion and sublingual microcirculatory alterations in severe sepsis and septic shock: a prospective observational study

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    Objective: Measurement of central-to-toe temperature difference has been advocated as an index of severity of shock and as a guide for circulatory therapy in critically ill patients. However, septic shock, in contrast to other forms of shock, is associated with a distributive malfunction resulting in a disparity between vascular compartments. Although this disparity has been established between systemic and microcirculatory parameters, it is unclear whether such disparity exists between skin perfusion and microcirculation. To test this hypothesis of disparity, we simultaneously measured parameters of the two vascular compartments, in the early phase of sepsis. Design: Prospective observational study in patients with severe sepsis/septic shock in the first 6 h of ICU admission. Simultaneous measurements of central-to-toe temperature difference and sublingual microcirculatory orthogonal polarization spectral imaging, together with parameters of systemic hemodynamics. Setting: 22 bed mixed-ICU in a tertiary teaching hospital. Patients: 35 consecutive patients in a 12-month period. Measurements and results: In 35 septic patients and a median APACHE II score of 20, no correlation between central-to-toe temperature gradient and microvascular flow index was observed (r(s) =-0.08, p = 0.65). Also no significant correlation between temperature gradient/microvascular flow index and systemic hemodynamic parameters could be demonstrated. Conclusions: During the early phase of resuscitated severe sepsis and septic shock there appears to be no correlation between sublingual microcirculatory alterations and the central-to-toe temperature difference. This finding adds to the concept of a dispersive nature of blood flow under conditions of sepsis between microcirculatory and systemic hemodynamic

    The Reduction in Right Ventricular Longitudinal Contraction Parameters Is Not Accompanied by a Reduction in General Right Ventricular Performance During Aortic Valve Replacement:An Explorative Study

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    Objective: The aim of the present study was to identify whether the decrease of longitudinal parameters after cardiothoracic surgery (ie, tricuspid annular systolic plane excursion [TAPSE] and systolic excursion velocity [S']) is accompanied by a reduction in global right ventricular (RV) performance. Design: Prospective, observational study. Setting: Single-center explorative study in a tertiary teaching hospital. Participants: The study comprised 20 patients who underwent aortic valve replacement with or without coronary artery bypass grafting. Interventions: During cardiac surgery, simultaneous measurements of RV function were performed with a pulmonary artery catheter and transesophageal echocardiography. Measurements and Main Results: TAPSE and S’ were reduced significantly directly after surgery compared with the time before surgery (TAPSE from 20.8 [16.6-23.4] mm to 9.1 [5.6-15.5] mm; p < 0.001 and S’ from 8.7 [7.9-10.7] cm/s to 7.2 [5.7-8.6] cm/s; p = 0.041). However, the reduction in TAPSE and S’ was not accompanied by a reduction in RV performance, as assessed with the TEE-derived myocardial performance index (MPI) and pulmonary artery catheter–derived RV ejection fraction (RVEF). Both remained statistically unaltered before and after the procedure (MPI from 0.52 [0.43-0.58] to 0.50 [0.42-0.88]; p = 0.278 and RVEF from 27% [22%-32%] to 26% [22%-28%]; p = 0.294). Conclusions: In the direct postoperative phase, the reduction of echocardiographic parameters of longitudinal RV contractility (TAPSE and S’) were not accompanied by a reduction in global RV performance, expressed as MPI and RVEF. Solely relying on a single RV parameter as a marker for global RV performance may not be adequate to assess the complex adaptation of the right ventricle to aortic valve replacement

    Ендокринний та імунний супровід поліваріантних вегетотонічних ефектів біоактивної води Нафтуся у жінок

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    Среди женщин репродуктивного возраста с гиперплазией щитовидной железы автоиммунной природы, на которых курсовое питье биоактивной воды Нафтуся оказывало разнонаправленные вегетотонические эффекты, в эндокринном статусе выявлены незначительные различия между начальными уровнями общего трийодтиронина, альдостерона и прогестерона, а также между выразительностью, но не направленностью сопутствующих изменений общего тироксина и эстрадиола. Сопутствующие изменения иммунного статуса можно сгруппировать в три паттерна.Among the women of reproductive age with hyperplasia of thyroide glands of autoimmune nature, on which course drinking of bioactive water Naftussya made differ vegetotonic effects, the insignificant divergences between initial levels common tryiodthyronin, aldosteron and progesteron, and also between expressiveness, but not by an orientation of accompanying changes common thyroxin and estradiol are revealed. Accompanied changes of immune status groupped in three patterns

    Improvement of Sidestream Dark Field Imaging with an Image Acquisition Stabilizer

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    Background: In the present study we developed, evaluated in volunteers, and clinically validated an image acquisition stabilizer (IAS) for Sidestream Dark Field (SDF) imaging.Methods: The IAS is a stainless steel sterilizable ring which fits around the SDF probe tip. The IAS creates adhesion to the imaged tissue by application of negative pressure. The effects of the IAS on the sublingual microcirculatory flow velocities, the force required to induce pressure artifacts (PA), the time to acquire a stable image, and the duration of stable imaging were assessed in healthy volunteers. To demonstrate the clinical applicability of the SDF setup in combination with the IAS, simultaneous bilateral sublingual imaging of the microcirculation were performed during a lung recruitment maneuver (LRM) in mechanically ventilated critically ill patients. One SDF device was operated handheld; the second was fitted with the IAS and held in position by a mechanic arm. Lateral drift, number of losses of image stability and duration of stable imaging of the two methods were compared.Results: Five healthy volunteers were studied. The IAS did not affect microcirculatory flow velocities. A significantly greater force had to applied onto the tissue to induced PA with compared to without IAS (0.25 ± 0.15 N without vs. 0.62 ± 0.05 N with the IAS, p < 0.001). The IAS ensured an increased duration of a stable image sequence (8 ± 2 s without vs. 42 ± 8 s with the IAS, p < 0.001). The time required to obtain a stable image sequence was similar with and without the IAS. In eight mechanically ventilated patients undergoing a LRM the use of the IAS resulted in a significantly reduced image drifting and enabled the acquisition of significantly longer stable image sequences (24 ± 5 s without vs. 67 ± 14 s with the IAS, p = 0.006).Conclusions: The present study has validated the use of an IAS for improvement of SDF imaging by demonstrating that the IAS did not affect microcirculatory perfusion in the microscopic field of view. The IAS improved both axial and lateral SDF image stability and thereby increased the critical force required to induce pressure artifacts. The IAS ensured a significantly increased duration of maintaining a stable image sequence

    Public health information needs in districts

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