Impact of sepsis education for healthcare professionals and students on learning and patient outcomes: a systematic review.

BACKGROUND: Sepsis is an important global healthcare problem that is a key challenge faced by healthcare professionals face worldwide. One key effort aimed at reducing the global burden of sepsis is educating healthcare professionals about early identification and management of sepsis. AIM: To provide a comprehensive evaluation of sepsis education among healthcare professionals and students. METHODS: Six databases (PubMed, CINAHL, Embase, MEDLINE, Cochrane Central Register of Controlled Trials, and Scopus) were searched. We included studies that described and evaluated any form of education or training on sepsis delivered to healthcare professionals and students. Study outcomes were summarized according to the adapted Kirkpatrick model of training evaluation. RESULTS: Thirty-two studies were included in the review. The learning contents were reported to be in accordance with the Surviving Sepsis Campaign guidelines. Seven studies included the topic of interprofessional teamwork and communication in their sepsis education content. Most educational programmes were effective and reported positive effects on immediate knowledge outcomes. Interventions that were delivered through an active learning approach such as simulation and game-based learning generally produced greater gains than didactic teaching. Improvements in patient care processes and patient outcomes were associated with the concomitant existence or implementation of a hospital sepsis care bundle. CONCLUSION: Incorporating active learning strategies into sepsis education interventions has the potential to improve learners' long-term outcomes. In addition, sepsis education and a protocol-based sepsis care bundle act in synergy to augment greater improvements in care processes and patient benefits.

Negative photoconductivity and memory effects of germanium nanocrystals embedded in HfO2 dielectric.

A metal-insulator-semiconductor (MIS) structure containing an HfO2/SiO2 stack tunnel layer, isolated Germanium (Ge) nanocrystals, and an HfO2 capping layer, was obtained by an electron-beam evaporation method. A high-resolution transmission electron microscopy (HRTEM) study revealed that uniform and pronounced Ge nanocrystals had formed after annealing. Raman spectroscopy provided evidence for the formation of Ge-Ge bonds and the optimal annealing temperature for the crystallization ratio of the Ge. The electric properties of the MIS structure were characterized by capacitance-voltage (C-V) and current-voltage (I-V) measurements at room temperature. Negative photoconductivity was observed when the structure was under a forward bias, which screened the bias voltage, resulting in a decrease in the current at a given voltage and a negative shift in flat band voltage. A relatively high stored charge density of 3.27 x 10(12) cm 2 was also achieved.

Thermal stability of hemoglobin and myoglobin: effect of spin states.

The thermal stability of various methemoglobin and metmyoglobin derivatives at different ligand concentrations and pH were studied by the method of differential scanning calorimetry. Comparing to water as a ligand, cyanide and azide are most effective in protecting the protein; fluoride stabilizes the protein slightly whereas imidazole and thiocyanate have little effect. Assuming thermal denaturation can be described by an activated two-state process, the activation parameters of all the derivatives were determined. We have also found that the stability of hemoglobin and myoglobin does not correlate with the iron atom spin state but depends instead on steric interactions with the ligands. On the reasonable assumption that structure and stability are related, this implies a definite dependence of structure on steric interactions.

Kinetics of the pretransition of synthetic phospholipids. A calorimetric study.

The pretransition in aqueous dispersions of two synthetic phospholipids (dimyristoylphosphatidylcholine and dipalmitoylphosphatidylcholine) has been examined in detail by differential scanning calorimetry. The transition from the high-temperature state (state above pretransition) to the low-temperature state (state below pretransition) is complex and appears to occur via some metastable states. In contrast, the kinetics of the transition from the low- to the high-temperature state is consistent with an activated two-state model. The observed hysteresis is shown to arise mainly from the kinetic nature of the pretransition.

Ultrasonic absorption in myoglobin and other globular proteins.

The ultrasonic absorption of myoglobin has been measured by the resonance and pulse-echo techniques as a function of pH. The absorption at a given frequency can be separated into pH-dependent and pH-independent contributions. Like other proteins, two peaks at pH 3 and 11.5 are observed which can be accounted for a proton-transfer reactions of the side-groups. In addition, the absorption undergoes a large increase within a small range of 0.2 pH unit at pH around 4, when denaturation of myoglobin occurs, indicating that the absorption is sensitive to the overall protein conformation. To elucidate the origin of the pH-independent component, the absorptions of several other globular proteins at neutral pH are also measured. The absorptions of these proteins exhibit a linear correlation with their isothermal compressibilities, suggesting that the pH-independent component is related to volume fluctuations of protein molecules. The activation energy of 4 kcal/mol found for this relaxation is consistent with such an interpretation.

Electron transfer between cytochrome c and metal hexacyanide complexes. Effect of thermodynamic driving force on the electron transfer rate.

The electron transfer reactions between ferrocytochrome c and three isomorphic hexacyanide complexes, [Fe(CN)6]3-, [Os(CN)6]3- and [Ru(CN)6]3-, have been studied using the method of photoexcitation. The transfer rates for [Os(CN)6]3- and [Ru(CN)6]3- are, respectively, about 45- and 200-times higher than that of [Fe(CN)6]3-. A reorganization energy of approx. 0.8 eV was found for the cytochrome c-hexacyanide system when the data were analyzed according to the theory of Marcus.

The thermodynamics of myoglobin stability. Effects of axial ligand.

The reversible thermal denaturation of four metmyoglobin derivatives, aquomet, cyanomet, azidomet and fluoromet in both the alkaline pH and acidic pH region, has been examined by optical spectrophotometry. The data are analyzed in terms of a two-state model to extract the thermodynamic parameters delta G, delta H, delta S and delta Cp characterizing the transition. The results are consistent with Brandts' phenomenological model of protein denaturation. Among the derivatives examined, cyanomet, azidomet and fluoromet are about 3 kcal/mol, 2 kcal/mol and 0.2 kcal/mol, respectively, more stable than aquometmyoglobin. The observed differences are found to be inconsistent with the hypothesis that the stability is mainly governed by the spin state of the iron atom. In addition, the enthalpic and entropic contributions in delta G are extracted and the differences in delta G for the various derivatives are found to arise from minor changes in delta H and T delta S. Assuming the final denaturated state to be universal, these changes reflect the effect of ligands on the conformational energy of the native protein.

Adiabatic compressibility of myoglobin. Effect of axial ligand and denaturation.

An ultrasonic technique has been employed to study the adiabatic compressibility of three metmyoglobin derivatives (aquomet-, fluoromet- and azidometmyoglobin) at neutral pH, and aquometmyoglobin as a function of pH in the frequency range of 1-10 MHz at 20 degrees C. No difference was observed in the adiabatic compressibility of the various derivatives. This indicates that the binding of different axial ligands to myoglobin does not affect significantly the conformational fluctuations of the protein. The finding is consistent with the results of the hydrogen exchange rate experiment, indicating that both types of measurements are useful for the study of protein dynamics. Upon acid-induced denaturation, the adiabatic compressibility of myoglobin drops from 5.3 X 10(-12) cm2/dyn to 0.5 X 10(-12) cm2/dyn. Plausible reasons for such a decrease are discussed.

Kinetics of electron transfer between cytochrome c and iron hexacyanides. Evidence for two electron-transfer sites.

The electron-transfer reaction between ferrocytochrome c and ferricyanide has been studied by the method of photoexcitation. The observed transfer rate shows saturation behaviour at high ferricyanide concentration. Data analysis indicates that there are two binding sites of vastly different affinities at which electron transfer occurs. The binding constant for the strong binding site decreases from 1600 M-1 to 80 M-1 as the ionic strength increases from 15 mM to 140 mM. At 20 degrees C, the intramolecular electron-transfer rate for this site is 4.65 X 10(4) s-1, which gives an electron-transfer distance of approx. 9.7 A according to Hopfield's model.

A simple and convenient route to prepare poly(vinylidene fluoride trifluoroethylene) copolymer nanowires and nanotubes.

Poly(vinylidene fluoride trifluoroethylene) copolymer nanowires and nanotubes have been prepared for the first time via a high temperature (

Piezoelectric and pyroelectric properties of PZT/P(VDF-TrFE) composites with constituent phases poled in parallel or antiparallel directions.

Composites of lead zirconate titanate (PZT) powder dispersed in a vinylidene fluoride-trifluoroethylene copolymer [P(VDF-TrFE)] matrix have been prepared by compression molding. Three groups of polarized samples have been prepared by poling: only the ceramic phase, the ceramic and polymer phases in parallel directions, and the two phases in antiparallel directions. The measured permittivities of the unpoled composites are consistent with the predictions of the Bruggeman model. The changes in the pyroelectric and piezoelectric coefficients of the poled composites with increasing ceramic volume fraction can be described by modified linear mixture rules. When the ceramic and copolymer phases are poled in the same direction, their pyroelectric activities reinforce while their piezoelectric activities partially cancel. However, when the ceramic and copolymer phases are poled in opposite directions, their piezoelectric activities reinforce while their pyroelectric activities partially cancel.

PCLT/P (VDF-TrFE) nanocomposite pyroelectric sensors.

Thin composite films consisting of 12 vol% of nanosized lanthanum and calcium-modified lead titanate (PCLT) powder embedded in a vinylidene fluoride-trifluoroethylene copolymer [P(VDF-TrFE)] matrix were deposited on silicon (Si) substrates to form pyroelectric sensors with three different configurations. The influences of a thermal buffer layer and back etching of the silicon substrate on the current and voltage responsivities of the sensors were investigated theoretically and experimentally. The specific detectivity of the sensors was also calculated from the measured voltage responsivity and noise.

A standing wave-type noncontact linear ultrasonic motor.

In this study, a novel standing wave-type noncontact linear ultrasonic motor is proposed and analyzed. This linear ultrasonic motor uses a properly controlled ultrasonic standing wave to levitate and drive a slider. A prototype of the motor was constructed by using a wedge-shaped aluminum stator, which was placed horizontally and driven by a multilayer PZT vibrator. The levitation and motion of the slider were observed. Assuming that the driving force was generated by the turbulent acoustic streaming in the boundary air layer next to the bottom surface of the slider, a theoretical model was developed. The calculated characteristics of this motor were found to agree quite well with the experimental results. Based on the experimental and theoretical results, guidelines for increasing the displacement and speed of the slider were obtained. It was found that increasing the stator vibration displacement, or decreasing the gradient of the stator vibration velocity and the weight per unit area of the slider, led to an increase of the slider displacement. It was also found that increasing the amplitude and gradient of the stator vibration velocity, or decreasing the weight per unit area of the slider and the driving frequency, gave rise to an increase of the slider speed. There exists an optimum roughness of the bottom surface of the slider at which the slider speed has a maximum.

Lead zirconate titanate/poly(vinylidene fluoride-trifluoroethylene) 1-3 composites for ultrasonic transducer applications.

A new procedure for preparing lead zirconate titanate (PZT)/poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) 1-3 composites with both phases piezoelectrically active is described. Sintered PZT rods are inserted into a prepoled copolymer matrix, and the composite is repoled under a lower electric field. Using this new procedure, the dipoles in the two phases are aligned in either the same or opposite directions. Composite disks, of 12.7-cm diameter and 0.33- to 0.60-mm thicknesses, have been fabricated with PZT rods of 0.8 or 1 mm diameter distributed in a square pattern with 3 mm center-to-center separation. The ceramic volume contents of the composite disks are 3.6 and 5.6%, respectively. The resonance characteristics of the composite disks consist of the resonance modes of the two constituent phases, but they are dominated by the coupled longitudinal thickness mode (H-mode) of the PZT rods. The coupled radial mode (L-mode) resonance of the PZT rods is significant only for thin disks. The observed resonance frequencies of the H- and L-modes agree well with the values calculated from the coupling theory. The thickness mode resonance of the copolymer matrix (T-mode) is present but hardly observable in thick disks. The composite disks have been fabricated into transducers with air-backing and with no front face matching layer, and their performance characteristics have been evaluated in water. The transmitting and receiving voltage responses of a PZT/P(VDF-TrFE) composite transducer are better than those of a PZT/epoxy composite transducer. The transmitting and receiving voltage responses are improved when the PZT rods and copolymer matrix are poled in opposite directions, especially when the resonance frequencies of the H- and T-modes are approximately equal. When the phases are poled in the same direction and the resonance peaks associated with the Hand T-modes just overlap, the bandwidth is improved. Using 0.33-mm thick composite disks, a transducer can be produced with three operating frequencies by poling the constituent phases in the same direction, or with two operating frequencies at equal efficiency by poling the constituent phases in opposite directions. The PZT/P(VDF-TrFE) 1-3 composite transducer, especially the one with multiple operating frequencies, should be very promising in the applications of medical ultrasonic imaging.

Ultrasonic transducers using electron-irradiated vinylidene fluoride-trifluoroethylene copolymers.

Single-element, planar transducers have been fabricated using electron-irradiated poly(vinylidene fluoride-trifluoroethylene) 80/20 mol% copolymers with different electron dosage. Electrical field-induced strain response of copolymer film with 100 Mrad dosage has been studied at 5 kHz and the electrostrictive coefficient was calculated. The transmitting response of the air-backing and epoxy-backing transducers was evaluated with the application of high DC bias voltages. Clear ultrasonic amplitudes and high frequency spectrum (>20 MHz) were observed when driven from a standard ultrasonic voltage source through a decoupling circuit. It has also showed that larger generation of ultrasonic waves will be induced under high DC bias field, which is due to the increase of induced d(33) piezoelectric coefficient. Two different polar bias voltages, positive and negative, were applied to the transducers and inverse waveforms were received, which was coincident with the theoretical analysis of the strain response of electrostrictive film.