Team planning discussion and clinical performance: a prospective, randomised, controlled simulation trial.

Planning held before emergency management of a critical situation might be an invaluable asset for optimising team preparation. The purpose of this study was to investigate whether a brief planning discussion improved team performance in a simulated critical care situation. Forty-four pairs of trainees in anaesthesia and intensive care were randomly allocated to either an intervention or control group before participating in a standardised simulated scenario. Twelve different scenarios were utilised. Groups were stratified by postgraduate year and simulated scenario, and a facilitator was embedded in the scenario. In the intervention group, the pairs had an oral briefing followed by a 4-min planning discussion before starting the simulation. The primary end-point was clinical performance, as rated by two independent blinded assessors on a score of 0-100 using video records and pre-established scenario-specific checklists. Crisis resource management and stress response (cognitive appraisal ratio) were also assessed. Two pairs were excluded for technical reasons. Clinical performance scores were higher in the intervention group; mean (SD) 51 (9) points vs. 46 (9) in the control group, p = 0.039. The planning discussion was also associated with higher crisis resource management scores and lower cognitive appraisal ratios, reflecting a positive response. A 4-min planning discussion before a simulated critical care situation improved clinical team performance and cognitive appraisal ratios. Team planning should be integrated into medical education and clinical practice.

From 3D to 2D zeolite catalytic materials.

Research activities and recent developments in the area of three-dimensional zeolites and their two-dimensional analogues are reviewed. Zeolites are the most important industrial heterogeneous catalysts with numerous applications. However, they suffer from limited pore sizes not allowing penetration of sterically demanding molecules to their channel systems and to active sites. We briefly highlight here the synthesis, properties and catalytic potential of three-dimensional zeolites followed by a discussion of hierarchical zeolites combining micro- and mesoporosity. The final part is devoted to two-dimensional analogues developed recently. Novel bottom-up and top-down synthetic approaches for two-dimensional zeolites, their properties, and catalytic performances are thoroughly discussed in this review.

Use of a hand-held digital cognitive aid in simulated crises: the MAX randomized controlled trial.

BACKGROUND: Cognitive aids improve the technical performance of individuals and teams dealing with high-stakes crises. Hand-held electronic cognitive aids have rarely been investigated. A randomized controlled trial was conducted to investigate the effects of a smartphone application, named MAX (for Medical Assistance eXpert), on the technical and non-technical performance of anaesthesia residents dealing with simulated crises. METHODS: This single-centre randomized, controlled, unblinded trial was conducted in the simulation centre at Lyon, France. Participants were anaesthesia residents with >1 yr of clinical experience. Each participant had to deal with two different simulated crises with and without the help of a digital cognitive aid. The primary outcome was technical performance, evaluated as adherence to guidelines. Two independent observers remotely assessed performance on video recordings. RESULTS: Fifty-two residents were included between July 2015 and February 2016. Six participants were excluded for technical issues; 46 participants were confronted with a total of 92 high-fidelity simulation scenarios (46 with MAX and 46 without). Mean (sd) age was 27 (1.8) yr and clinical experience 3.2 (1.0) yr. Inter-rater agreement was 0.89 (95% confidence interval 0.85-0.92). Mean technical scores were higher when residents used MAX [82 (11.9) vs 59 (10.8)%; P<0.001]. CONCLUSION: The use of a hand-held cognitive aid was associated with better technical performance of residents dealing with simulated crises. These findings could help digital cognitive aids to find their way into daily medical practice and improve the quality of health care when dealing with high-stakes crises. CLINICAL TRIAL REGISTRATION: NCT02678819.

Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption.

The advanced investigation of pore networks in isoreticular zeolites and mesoporous materials related to the IPC family was performed using high-resolution argon adsorption experiments coupled with the development of a state-of-the-art non-local density functional theory approach. The optimization of a kernel for model sorption isotherms for materials possessing the same layer structure, differing only in the interlayer connectivity (e.g. oxygen bridges, single- or double-four-ring building units, mesoscale pillars etc.) revealed remarkable differences in their porous systems. Using high-resolution adsorption data, the bimodal pore size distribution consistent with crystallographic data for IPC-6, IPC-7 and UTL samples is shown for the first time. A dynamic assessment by positron annihilation lifetime spectroscopy (PALS) provided complementary insights, simply distinguishing the enhanced accessibility of the pore network in samples incorporating mesoscale pillars and revealing the presence of a certain fraction of micropores undetected by gas sorption. Nonetheless, subtle differences in the pore size could not be discriminated based on the widely-applied Tao-Eldrup model. The combination of both methods can be useful for the advanced characterization of microporous, mesoporous and hierarchical materials.

Theoretical investigation of layered zeolites with MWW topology: MCM-22P vs. MCM-56.

The inter-layer interactions and the possible arrangements of MWW-type layers were investigated computationally at the non-local density functional theory level. Powder XRD patterns were simulated for structures obtained computationally and compared with experimental data. The MCM-22P material corresponds to the layers bound with relatively strong hydrogen bonds between surface silanol groups that is an energetically preferred structure in the presence of a structure directing agent (hexamethyleneimine). The powder XRD pattern of MCM-56 is best matched for relatively disordered (in the ab plane) MWW layers that are partially condensed. The appearance of the powder XRD pattern in the 2θ range of 7.5-10° depends on the extent of interlayer condensation. The combination of density functional investigation of interactions between MWW layers together with simulation of powder XRD patterns brings atomistic insight into the inter-layer arrangement and better understanding of the effects responsible for the differences between various layered materials of the MWW family.

Resuscitation with lipid, epinephrine, or both in levobupivacaine-induced cardiac toxicity in newborn piglets.

BACKGROUND: The optimal dosing regimens of lipid emulsion, epinephrine, or both are not yet determined in neonates in cases of local anaesthetic systemic toxicity (LAST). METHODS: Newborn piglets received levobupivacaine until cardiovascular collapse occurred. Standard cardiopulmonary resuscitation was started and electrocardiogram (ECG) was monitored for ventricular tachycardia, fibrillation, or QRS prolongation. Piglets were then randomly allocated to four groups: control (saline), Intralipid(®) alone, epinephrine alone, or a combination of Intralipd plus epinephrine. Resuscitation continued for 30 min or until there was a return of spontaneous circulation (ROSC) accompanied by a mean arterial pressure at or superior to the baseline pressure and normal sinus rhythm for a period of 30 min. RESULTS: ROSC was achieved in only one of the control piglets compared with most of the treated piglets. Mortality was not significantly different between the three treatment groups, but was significantly lower in all the treatment groups compared with control. The number of ECG abnormalities was zero in the Intralipid only group, but 14 and 17, respectively, in the epinephrine and epinephrine plus lipid groups (P<0.05). CONCLUSIONS: Lipid emulsion with or without epinephrine, or epinephrine alone were equally effective in achieving a return to spontaneous circulation in this model of LAST. Epinephrine alone or in combination with lipid was associated with an increased number of ECG abnormalities compared with lipid emulsion alone.

Thermodynamics of CO2 adsorption on functionalized SBA-15 silica. NLDFT analysis of surface energetic heterogeneity.

Siliceous SBA-15 mesoporous molecular sieves were functionalized with different amounts of 3-aminopropyl-trimethoxysilane. To obtain a more detailed insight into the material properties of the prepared samples, their textural parameters were combined with results of thermal analysis. Adsorption isotherms of carbon dioxide on parent and functionalized SBA-15 were measured in the temperature range from 273 to 333 K. From the temperature dependence of CO(2) isotherms the isosteric adsorption heats of CO(2) were determined and discussed. Information about the surface energetic heterogeneity caused by tethered 3-aminopropyl groups were obtained from CO(2) adsorption energy distributions calculated using the theoretical CO(2) adsorption isotherms derived from the non-local density functional theory. The values of isosteric heats and the energy distributions of CO(2) adsorption detect highly energetic sites and enabled quantification of their concentrations.

Grafting of alumina on SBA-15: effect of surface roughness.

Alumina-grafted materials were prepared by postsynthesis alumination of mesoporous SBA-15 silica in an aqueous solution of aluminum chlorhydrol. Prepared samples were characterized by nitrogen adsorption, scanning electron microscopy, X-ray powder diffraction, and (27)Al magic-angle-spinning NMR. The successive grafting of alumina on SBA-15 leads to a gradual filling of the corona surrounding the mesopores. As a consequence smoothing of the mesopore surface takes place. The in-depth analysis of nitrogen adsorption data proves that the alpha s method affords real values of the structure parameters, while the Kruk, Jaroniec, and Sayari (KJS) procedure based on the BJH algorithm provides only effective data corresponding to cylindrical mesopores of smooth geometrical surface. The quantification of the roughness of the SBA-15 mesopore surface based on the comparison of data obtained from the alpha s plot and KJS method was carried out.

Norleucine, a natural occurrence in a novel ergot alkaloid gamma-ergokryptinine.

A novel natural peptide ergot alkaloid gamma-ergokryptinine containing norleucine has been isolated from ergot sclerotia of the field-growing parasitic fungus Claviceps purpurea CCM 8059. Its structure was deduced from the NMR and mass spectral data. The final structural proof was provided by the crystal structure determination, which is the first X-ray structure of a natural Nle-containing secondary metabolite. The conformations of three ergopeptinines: gamma-ergokryptinine, ergoladinine, and alpha-ergokryptinine were compared.

LVV-hemorphin-7 lowers blood pressure in spontaneously hypertensive rats: radiotelemetry study.

Cardiovascular effects of LVV-hemorphin-7, a member of the family of fragments from beta-chain of human or bovine hemoglobin, were studied in conscious spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats by radiotelemetry. Intraperitoneal injection of hemorphin in a dose of 100 microg/kg significantly decreased blood pressure in SHR, whereas negligible effect was seen in normotensive WKY rats. Blood pressure changes were accompanied by reduction of heart rate. In conclusion, a direct effect of LVV-hemorphin-7 on blood pressure was demonstrated in SHR. These biologically active peptides could be involved in blood pressure regulation especially in hypertensive rats, but the precise mechanism should be elucidated.

Does Cd36 gene play a key role in disturbed glucose and fatty acid metabolism in Prague hypertensive hypertriglyceridemic rats?

Close links between hypertension, hypertriglyceridemia, insulin resistance and other symptoms of metabolic syndrome was demonstrated in humans and experimental animals. Quantitative trait loci for defects in glucose and fatty acid metabolism, hypertriglyceridemia and hypertension were mapped in spontaneously hypertensive rats (SHR) on chromosome 4 and defective Cd36 gene was identified in this region. Here we investigated the polymorphism of Cd36 gene in Prague hereditary hypertriglyceridemic (HTG) rats, which represent another model of genetic hypertension and metabolic syndrome. These animals were compared with NIH-derived SHR and two different normotensive control strains (WKY, LEW). In spite of the fact that HTG and SHR rats had similar metabolic disturbances, genotype analysis of PCR products has shown that Cd36 mutation was not present in HTG rats. In conclusion, we have revealed that defective Cd36 is probably a candidate gene for disorded fatty-acid metabolism, glucose intolerance and insulin resistance in NIH-derived SHR, but other genes might play a role in pathogenesis of metabolic syndrome in Prague hereditary hypertriglyceridemic rats. This is in accordance with the absence of defective Cd36 gene in original SHR from Japan.

Assessment of cardiovascular autonomic control by the empirical mode decomposition.

OBJECTIVES: Heart-rate variability (HRV) is an interesting tool for assessing cardiac autonomic system control, but nonstationarities raise problematic issues. The objective of this paper is to show that adapted signal processing tools may cope with nonstationary situations and improve the analysis of HRV. METHODS: We propose to use the recent method of Empirical Mode Decomposition (EMD), so as to analyze the cardiac sympatho-vagal balance on automatically extracted modes. The method, which is fully data-adaptive, consists in an iterative decomposition based on the idea that any signal can be locally represented as an oscillation superimposed to a more regular trend. When a signal is composed of distinct nonstationary components, EMD therefore achieves a time-varying filtering which effectively separates them. RESULTS: The method has been applied to situations where postural changes occur, provoking instantaneous changes in heart rate as a result of autonomic modifications. In the considered application where the sympatho-vagal balance is quantified by comparing the low-frequency (LF) and high-frequency (HF) components of RR intervals, EMD automatically achieves a separation of these components upon which further processing can be carried. Visualizing the decomposition in the time-frequency plane, we can identify local events due to the postural changes, and we can assess a (time-varying) HF vs. LF discrimination without resorting to some fixed high-pass/low-pass filtering. CONCLUSION: Assessing cardiovascular autonomic control by resorting to LF/HF measurements may prove difficult in nonstationary situations where the use of a priori fixed filters can be questioned. Because it is both local and fully data-adaptive, EMD appears as an appealing and versatile pre-processing technique for overcoming some of the limitations that conventional spectral methods are faced with in nonstationary situations.

Activation of calcium influx by ATP and store depletion in primary cultures of renal proximal cells.

Cytoplasmic calcium changes and calcium influx evoked by adenosine triphosphate (ATP) were investigated in primary cultures of rabbit proximal convoluted tubule cells. Extracellular ATP (50 microM) induced a biphasic increase of [Ca2+]i measured with the calcium probe fura-2. In the early phase, the mobilization of intracellular pools resulted in a transient increase of [Ca2+]i from 106 +/- 11 nM (n = 36) to 1059 +/- 115% (n = 29) of the resting level within 10 s. In the presence of external calcium, [Ca2+]i then decreased within 3 min to a sustained level (398 +/- 38%, n = 8). Measurements of fura-2 quenching by external manganese revealed that this phase was the result of an increased Ca2+ uptake, blocked by lanthanum (10 microM) and verapamil (100 microM) but not by the nifedipin (25 microM). Internal calcium store depletion by ATP induced an increased calcium influx through lanthanum- and verapamil-sensitive, nifedipin-insensitive calcium channels, located on the apical membrane of the cells. As indicated by 86Rb+ efflux measurements, ATP activated a potassium efflux that was blocked by barium and Leiurus quinquestriatus hebraeus (LQH) venom (containing charybdotoxin) indicating the involvement of Ca(2+)-sensitive K+ channels. Moreover, in the presence of the LQH venom, the internal calcium stores were not replenished after being depleted by ATP. Our results indicate that an ATP-evoked hyperpolarization of the plasma membrane leads to increased Ca2+ influx, which facilitates the replenishment of the internal stores.

Developmental changes of adenocarcinoma-associated antigen.

The occurrence and serum concentrations of adenocarcinoma-associated antigen (ACAA) were studied during the fetal period of life, in newborns and in their mothers. The mean concentrations were significantly higher in fetal, newborn and maternal sera when compared with the mean concentration of ACAA in healthy, nonpregnant adults. Thus, ACAA appears to show fetospecific features as is known for other oncofetal proteins. ACAA should be recognized not only as a potential tumor marker, but also as a normal protein constituent of human serum.

Nucleotides mobilize intracellular calcium stores of renal proximal cells in primary culture: existence of a suramin-sensitive mechanism.

Changes of intracellular calcium concentrations [Ca2+]i were measured in primary cultured rabbit proximal convoluted tubules (PCT). A dual-excitation, digital-imaging inverted microscope was used to monitor the fura-2 fluorescence. The basal calcium level was 106 +/- 11 nM (n = 36). The stimulatory effects of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine were studied. ATP and ADP induced transient increases of [Ca2+]i (1059 +/- 115% of the resting level (n = 29), and 659 +/- 134% (n = 10), respectively) by releasing calcium from cytoplasmic stores. Adenosine had less effect (279 +/- 48% of the resting level, n = 3). In the same conditions the ATP antagonist suramin (100 microM) inhibited the action of ATP and ADP to 231 +/- 52% (n = 3), and 308 +/- 29% (n = 4) of the resting level, respectively, but did not modify that of adenosine (281 +/- 72%, n = 3). A pretreatment (500 ng/ml for 2 h at 37 degrees C) of the culture with the toxin of Bordetella pertussis completely blocked the ATP response. Our results are evidence for the presence of a functional suramin-sensitive ATP and ADP puriceptor in cultured renal proximal cells. A pertussis-toxin-sensitive G protein is linked to the transduction mechanism. This receptor is distinct from an adenosine puriceptor also found in the proximal monolayer.

Taurine deficiency after intensive chemotherapy and/or radiation.

Taurine, a nonessential amino acid (AA), is the most abundant free AA in the intracellular space. We measured plasma AA concentrations in 36 patients 7-28 d after intensive chemotherapy and/or radiation. Plasma taurine concentrations were uniformly low in all patients (20.0 +/- 6.4 mumol/L, mean +/- SD). Plasma taurine in 11 healthy volunteer control subjects was 45.0 +/- 20.3 mumol/L (P less than 0.001). Other AA concentrations, specifically those of precursor AAs methionine and cystine, were normal. We prospectively measured plasma AA concentrations in 12 patients before starting and 6-10 d after completing intensive cytotoxic treatment. Values before treatment were 37.2 +/- 11.6, 109.6 +/- 30.7, and 18.5 +/- 4.8 for taurine, cystine, and methionine, respectively, and were 24.3 +/- 6.0, 111.2 +/- 23.8, and 24.0 +/- 14.5 after treatment. Pretreatment plasma taurine correlated directly with the magnitude of decrease in plasma taurine during cytotoxic treatment (n = 12, r = 0.85, P less than 0.01). Intensive cytotoxic chemotherapy and/or radiation leads to a reduction in plasma taurine concentrations without any change in its precursor AAs, methionine and cystine. The clinical relevance of plasma taurine depletion will need further study.

Ontogeny of pancreatic oncofetal antigen.

Serum concentration of pancreatic oncofetal antigen (POA) was determined in human fetuses, newborns and pregnant women. The mean fetal concentration of POA (mean = 5.27 micrograms/ml) changed very little with gestational age. Also, only a weak correlation was found between POA concentration of newborns (mean = 5.15 micrograms/ml) and their birth weight. It appears that between the 19th and 40th weeks of gestation POA exhibits no fetospecific features, i.e. POA concentration did not exceed significantly the concentration of nonpregnant adults (mean = 6.10 micrograms/ml). A number of pathophysiological variables was correlated with POA concentrations of newborns. The most striking statistical differences were found between American black and white newborns and adults; the mean concentration of POA in sera of black full-term newborns was 5.38 micrograms/ml as compared to white newborns, where the mean concentration was 3.58 micrograms/ml. Similarly, black mothers had a mean concentration (mean = 12.21 micrograms/ml) significantly greater than white mothers (mean = 5.62 micrograms/ml).