Low-drift-rate external cavity diode laser.

We present the design, construction, and simulation of a simple, low-cost external cavity diode laser with a measured free-running frequency drift rate of 1.4(1) MHz/h at 852 nm. This performance is achieved in a compact aluminum structure held inside an airtight, temperature-controlled enclosure. The high thermal conductivity of the laser cavity and the stable temperature environment inside the enclosure minimize the time-varying, spatial temperature gradients across the laser cavity. We present thermal finite element method simulations, which quantify the effects of temperature gradients, and suggest that the drift rate is likely limited by the laser-diode and piezo-aging.

Paramedic to trauma team verbal handover optimization - a complex interaction.

BACKGROUND: Handover to the trauma team is crucial to trauma care. The emergency medical services (EMS) report must be concise, contain key details, and be time-limited. Effective handover is difficult, often occurring between unfamiliar teams, in chaotic environments, and without standardization. We aimed to evaluate handover formats in comparison to ad-lib communication during trauma handover. METHODS: We conducted a single-blind randomized simulation trial evaluating 2 structured handover formats. Paramedics randomly assigned to ad-lib, ISOBAR (identify, situation, observations, background, agreed plan, and readback) or IMIST (identification, mechanism/medical complaint, injuries/ information about complaint, signs, treatments) handover formats underwent scenarios in an ambulance, then transfer to the trauma team. Assessment of handovers was completed by the trauma team and by experts using audiovisual recordings. RESULTS: Twenty-seven simulations were conducted, 9 for each handover format. Participant ratings of the usefulness of the IMIST and ISOBAR formats were 9/10 and 7.5/10, respectively (p = 0.097). Quality of the handover was deemed higher by team members when a statement of objective vital signs and a logical format was used. Handovers delivered with confidence, directed and summarized by a trauma team leader, before physical patient transfer, and without interruption were identified as having the highest quality. The type of format was not a significant contributor to handover; however, we identified a matrix of factors affecting the quality of trauma handover. CONCLUSION: Our study shows agreement by prehospital and hospital personnel that a standardized handover tool is preferred. A brief confirmation of physiologic stability, including vital signs, limiting distractions, and team summarization improves handover effectiveness.

A descriptive analysis of the Canadian prehospital and transport transfusion (CAN-PATT) network.

Objective: Out-of-hospital blood transfusion (OHBT) is becoming increasingly common across the prehospital environment, yet there is significant variability in OHBT practices. The Canadian Prehospital and Transport Transfusion (CAN-PATT) network was established to collaborate, standardize, and evaluate the effectiveness of out-of-hospital blood transfusion (OHBT) across Canada. The objectives of this study are to describe the setting and organizational characteristics of CAN-PATT member organizations and to provide a cross-sectional examination of the current OHBT practices of CAN-PATT organizations. Methods: This was a cross-sectional examination of all six critical care transport organizations that are involved in CAN-PATT network. Surveys were sent to identified leads from each organization. The survey focused on three main areas of interest: 1) critical care transport organizational service and coverage, 2) provider, and crew configurations, and 3) OHBT transfusion practices. Results: All six surveys were completed and returned. There are a total of 30 critical care transport bases (19 rotor-wing, 20 fixed-wing and 6 land) across Canada and 11 bases have a blood-on-board program. Crew configurations very between organizations as either dual paramedic or paramedic/nurse teams. Median transport times range from 30 to 46 minutes for rotor-wing assets and 64 to 90 minutes for fixed-wing assets. Half of the CAN-PATT organizations started their out-of-hospital blood transfusion programs within the last three years. Most organizations carry at least two units of O-negative, K-negative red blood cells and some organizations also carry group A thawed plasma, fibrinogen concentrate and/or prothrombin complex concentrate. All organizations advocate for early administration of tranexamic acid for injured patients suspected of bleeding. All organizations return un-transfused blood components to their local transfusion medicine laboratory within a predefined timeframe to reduce wastage. Conclusions: Variations in OHBT practices were identified and we have suggested considerations for standardization of transfusion practices and patient care as it relates to OHBT. This standardization will also enable a robust means of data collection to study and optimize outcomes of patients receiving OHBT. A fulsome description of the participating organizations within CAN-PATT should enhance interpretation of future OHBT studies that will be conducted by this network.

Columbia Icefield Bus Rollover: A Case Study of Wilderness Mass Casualty Triage, Treatment, and Transport.

Mass casualty incidents (MCIs) are rare in wilderness and mountain settings. Few case studies have reported the response of such events within jurisdictions with well-developed trauma and emergency medical services systems (EMS). Here we explore a MCI in a wilderness setting on the Columbia Icefield inside the Jasper National Park within the Canadian Rocky Mountains. An all-terrain bus was involved that had rolled over while transporting tourists to explore the glacier. The bus rolled multiple times down the slope adjacent to the road, leading to 3 deceased and 21 patients requiring transport. A massive pre-hospital response ensued.Due to the location, extreme environment, and unusual complexities, the response involved significant use of aeromedical resources, physician field deployment, and centralized coordination centers. Readers are reminded of the importance of aeromedical surge capacity in allowing for effective distribution of patients to multiple receiving facilities. Our experience aligns with and reinforces many of the recommendations for wilderness MCI management; however, future research should focus on determining optimal triage strategies for mountain MCIs. Furthermore, future research should explore optimal strategies for developing a rescue chain given the availability of mixed transport resources, as well as the role of physicians in MCI response and where they are best placed in the incident command system.

Prehospital dexamethasone administration in children with croup: a medical record review.

OBJECTIVES: Croup is one of the most common childhood respiratory illnesses. Early dexamethasone administration in croup can improve patient outcomes. The objective of this study was to assess the clinical impact of prehospital administration of dexamethasone to children with croup. METHODS: A medical record review that included children between 6 months and 6 years, who were brought via emergency medical services (EMS) to the emergency department (ED) with a final diagnosis of croup, between January 2010 and December 2012, was conducted. Data were collected regarding prehospital management and ED management, length of stay (LOS), final disposition, and patient demographics. RESULTS: A total of 188 patients with an ED diagnosis of croup were enrolled, 35.1% (66/188) of whom received a prehospital diagnosis of croup. The mean age of the participants was 32.96±17.18 months and 10.6% (20/188) were given dexamethasone in the prehospital setting by EMS, while 30.3% (57/188) were given epinephrine nebulizations. Out of the 66 patients with a prehospital diagnosis of croup, 10.6% (7/66) were given dexamethasone by EMS. In ED, dexamethasone was administered to 88.3% (166/188) while 29.8% of participants (56/188) received epinephrine nebulizations. There was no significant difference in ED LOS between those who received prehospital dexamethasone (2.6±1.6 hours, n=18) and those who did not (3.3±2.7 hours, n=159) (P=0.514). The number of in-hospital epinephrine doses per patient was significantly influenced by the administration of prehospital dexamethasone (P=0.010). CONCLUSIONS: Prehospital administration of dexamethasone results in less ED epinephrine use and may reflect dexamethasone's positive influence on the severity and short-term persistence of croup symptoms.

Comparison of Nanoscale Focused Ion Beam and Electrochemical Lithiation in ß-Sn Microspheres.

The development of Li focused ion beams (Li-FIB) enables controlled Li ion insertion into materials with nanoscale resolution. We take the first step toward establishing the relevance of the Li-FIB for studies of ion dynamics in electrochemically active materials by comparing FIB lithiation with conventional electrochemical lithiation of isolated ß-Sn microspheres. Samples are characterized by cross-sectioning with Ga FIB and imaging via electron microscopy. The Li-FIB and electrochemical lithiated Sn exhibit similarities that suggest that the Li-FIB can be a powerful tool for exploring dynamical Li ion-material interactions at the nanoscale in a range of battery materials.

Rural trauma patients cannot wait: tranexamic Acid administration by helicopter emergency medical services.

OBJECTIVE: Tranexamic acid (TXA) administration has been shown to reduce mortality in bleeding trauma patients if given in the hospital within 3 hours of injury. Its use has been theorized to be of benefit in the prehospital environment. This study evaluates the timing of TXA administration in a critical care helicopter emergency medical service (HEMS) versus that of the destination trauma hospital. METHODS: We performed a retrospective chart review of consecutive trauma patients who were given TXA during HEMS transfer. The time of injury to HEMS arrival, TXA administration, and hospital arrival was collected. RESULTS: Twenty complete records were identified in which TXA was administered by HEMS: 11 scene calls and 9 interfacility transfers. The median time in minutes from the time of injury to HEMS arrival, TXA administration, and receiving hospital arrival was 90, 114, and 171, respectively, for scene calls and 134, 173, and 224, respectively, for interfacility transfers. CONCLUSION: TXA must be administered before arrival at a trauma hospital to meet the recommendation of administration within 3 hours of injury for all patients transferred between facilities and for many patients transported from a trauma scene.

Transfusing neonates based on platelet count vs. platelet mass: a randomized feasibility-pilot study.

The objective of this study was to obtain pilot data on which to judge the feasibility and sample size needed for a future comparative-effectiveness trial of platelet transfusions in the NICU. We conducted a limited-scope pilot trial in which neonates were randomized to receive platelet transfusions based on platelet mass vs. platelet count, using preset "transfusion-trigger" values. Analysis included parental consent rate, number of platelet transfusions given, bleeding episodes recorded, and mortality rate. Statistical analysis included ANOVA and Chi-square. A convenience sample of 30 were randomized; 15 per group. No differences were found between groups in gestational age, birth weight, race, gender or clinical diagnoses. The study consent rate was 52% (30/58). No differences were found in number of platelet transfusions received, bleeding episodes, or mortality. Lack of a trend in transfusion-reduction resulted in inability to estimate the number needed in a future comparative-effectiveness trial. Using platelet mass, rather than platelet count, for a NICU platelet transfusion trigger is feasible. However, any future comparative-effectiveness trial, testing the hypothesis that a platelet mass-based trigger reduces the transfusion rate will likely require a very large sample size.

Attaching high charge density metal ions to surfaces and biomolecules. Reaction chemistry of hypodentate cobalt diamine complexes.

Hypodentate diamine cobalt(III) pentammine complexes [Co(NH3)5(NH2(CH2)(n)NH3)](ClO4)4 (8: a: n = 3; b: n = 4; c: n = 6; d: n = 8) have been synthesized via the reaction of [Co(NH3)5(OTf)](OTf)2 (TfOH = CF3SO3H) with the corresponding diamines. The analogous t-boc protected diamine complexes [Co(NH3)5(NH2(CH2)(n)NHt-boc)](ClO4)3 (7a-d) were prepared in 4-26% yield. Low yields for the formation of 7a-d are due to competing side reactions which also gave [Co(NH3)6](3+). Complexes 7a-d were deprotected using trifluoroacetic acid to give the corresponding hypodentate diamine complexes [Co(NH3)5(NH2(CH2)(n)NH3)](CF3CO2)0.5(ClO4)3.5 (9a-d). HBTU coupling of 8c with N-(t-boc)-L-phenylalanine gave an amino acid functionalized cobalt pentammine complex [Co(NH3)5(NH2(CH2)6NHt-boc)-L-phenylalanine)](ClO4)3 (10). All new complexes were characterized using UV-vis and (1)H NMR spectroscopy, and elemental analysis. Grafting of 8c onto 2.4 mm poly(ethylene-co-acrylic acid) (PEAA) beads was achieved via amide coupling. Complex 8c was coupled to thioctic acid via amide coupling and the resulting cobalt disulfide complex [Co(NH3)5(N-(6-aminohexyl)-5-(1,2-dithiolan-3-yl)pentanamide)](ClO4)3 (11) was attached to 10 nm Au nanoparticles. The amount of cobalt loading onto PEAA beads and Au nanoparticles was determined using ICP-MS and EDX.

Temporal transcriptional response during infection of type II alveolar epithelial cells with Francisella tularensis live vaccine strain (LVS) supports a general host suppression and bacterial uptake by macropinocytosis.

Pneumonic tularemia is caused by inhalation of Francisella tularensis, one of the most infectious microbes known. We wanted to study the kinetics of the initial and early interactions between bacterium and host cells in the lung. To do this, we examined the infection of A549 airway epithelial cells with the live vaccine strain (LVS) of F. tularensis. A549 cells were infected and analyzed for global transcriptional response at multiple time points up to 16 h following infection. At 15 min and 2 h, a strong transcriptional response was observed including cytoskeletal rearrangement, intracellular transport, and interferon signaling. However, at later time points (6 and 16 h), very little differential gene expression was observed, indicating a general suppression of the host response consistent with other reported cell lines and murine tissues. Genes for macropinocytosis and actin/cytoskeleton rearrangement were highly up-regulated and common to the 15 min and 2 h time points, suggesting the use of this method for bacterial entry into cells. We demonstrate macropinocytosis through the uptake of FITC-dextran and amiloride inhibition of Francisella LVS uptake. Our results suggest that macropinocytosis is a potential mechanism of intracellular entry by LVS and that the host cell response is suppressed during the first 2-6 h of infection. These results suggest that the attenuated Francisella LVS induces significant host cell signaling at very early time points after the bacteria's interaction with the cell.

Accelerating the initial rate of hydrolysis of methyl parathion with laser excitation using monolayer protected 10 nm Au nanoparticles capped with a Cu(bpy) catalyst.

Using a low power green laser, we have demonstrated a rate acceleration of ~2-fold for the hydrolysis of methyl parathion by irradiating the plasmon absorption band of Au nanoparticles capped with a Cu(bpy) catalyst.

Monitoring viral RNA in infected cells with LNA flow-FISH.

We previously showed the feasibility of using locked nucleic acid (LNA) for flow cytometric-fluorescence in situ hybridization (LNA flow-FISH) detection of a target cellular mRNA. Here we demonstrate how the method can be used to monitor viral RNA in infected cells. We compared the results of the LNA flow-FISH with other methods of quantifying virus replication, including the use of an enhanced green fluorescent protein (EGFP) viral construct and quantitative reverse-transcription polymerase chain reaction. We found that an LNA probe complementary to Sindbis virus RNA is able to track the increase in viral RNA over time in early infection. In addition, this method is comparable to the EGFP construct in sensitivity, with both peaking around 3 h and at the same level of infected cells. Finally, we observed that the LNA flow-FISH method responds to the decrease in levels of viral RNA caused by antiviral medication. This technique represents a straightforward way to monitor viral infection in cells and is easily applicable to any virus.

Differential effects of Co(III), Ni(II), and Ru(III) amine complexes on Sindbis virus.

Transition metal complexes [Co(cyclen)(NH(3))(2)](ClO(4))(3)H(2)O (cyclen=1,4,7,10-tetraazacyclododecane) (2), [Co(NH(3))(5)(OH(2))](CF(3)SO(3))(3) (3) [Ni(NH(3))(6)]Br(2) (4) and [Ru(NH(3))(6)]Cl(3) (5) were tested against Sindbis infected baby hamster kidney (BHK) cells and show differential effects from the previously reported anti-viral complex [Co(NH(3))(6)]Cl(3) (1). The macrocyclic complex 2 and labile aqua complex 3 show either no or little effect on the survival on Sindbis virus-infected cells as compared to that for 1, which show a monotonic increase in % BHK cell survival. Nickel and ruthenium ammine complexes 4 and 5 had a moderate influence of cell survival. While the results showed some anti-viral activity for some of the structural variations, it appears that 1, with its potential to be a broad-spectrum anti-viral compound, occupies a unique position in its ability to both significantly enhance cell survival and to decrease viral expression of infected cells. We also show that 1 also shows anti-viral activity against Adenovirus lending support to the broad-spectrum potential of this complex.

Cobalt Complexes as Antiviral and Antibacterial Agents.

Metal ion complexes are playing an increasing role in the development of antimicrobials. We review here the antimicrobial properties of cobalt coordination complexes in oxidation state 3+. In addition to reviewing the cobalt complexes containing polydentate donor ligands, we also focus on the antimicrobial activity of the homoleptic [Co(NH3)6]3+ ion.

Antiviral properties of cobalt(III)-complexes.

We have investigated the potential antiviral activity of three cobalt(III) compounds. Two compounds, Co(III)-cyclen-methylbenzoic acid and its methyl ester derivative, are based on the macrocyclic chelator, cyclen, and were synthesized in our laboratory. Both compounds have been shown to bind tightly to nucleic acids and to hydrolyze phosphodiester bonds. However, neither compound exhibited any significant antiviral activity in an in vitro model of Sindbis virus replication. In contrast, a third compound, Co(III)hexammine, significantly inhibited Sindbis virus replication in baby hamster kidney (BHK) cells in a dose- and time-dependent manner. In plaque assays, the incubation of Co(III)hexammine with Sindbis virus resulted in a dose-dependent decrease in virus replication when measured at both 24 and 48-h post-infection. Over the concentration range of 0-5mM Co(III)hexammine, the IC(50) for the inhibition of viral replication was determined to be 0.10+/-0.04mM at 48h. Additionally, when BHK cell monolayers were pretreated with Co(III)hexammine for 6h prior to Sindbis infection, optimal cellular morphology and plasma membrane integrity were observed at 0.6-1.2mM Co(III)hexammine. Analysis by flow cytometry confirmed that Co(III)hexammine mediated a concomitant dose-dependent increase in BHK cell viability and a decrease in the percentage of Sindbis virus-infected cells (IC(50)=0.13+/-0.04mM). Our findings demonstrate for the first time that Co(III)hexammine possesses potent antiviral activity. We discuss our findings within the context of the ability to further functionalize Co(III)hexammine to render it a highly specific antiviral therapeutic reagent.

Mechanism of Ca(2+)/calmodulin-dependent protein kinase IV activation and of cyclic AMP response element binding protein phosphorylation during hypoxia in the cerebral cortex of newborn piglets.

Previously we showed that hypoxia results in increased neuronal nuclear Ca(2+) influx, Ca(2+)/calmodulin-dependent protein kinase IV activity (CaM KIV) and phosphorylation of c-AMP response element binding (CREB) protein. The aim of the present study was to understand the importance of neuronal nuclear Ca(2+) in the role of CaM KIV activation and CREB protein phosphorylation associated with hypoxia. To accomplish this the present study tests the hypothesis that clonidine administration will block increased nuclear Ca(2+) influx by inhibiting high affinity Ca(2+)/ATPase and prevent increased CaM KIV activity and CREB phosphorylation in the neuronal nuclei of the cerebral cortex of hypoxic newborn piglets. To accomplish this piglets were divided in three groups: normoxic, hypoxic, and hypoxic-treated with clonidine. The piglets that were in the Hx+Cl group received clonidine 5 min prior to hypoxia. Cerebral tissue hypoxia was confirmed biochemically by tissue levels of ATP and phosphocreatine (PCr). The data show that clonidine prevents hypoxia-induced increase in CaM KIV activity and CREB protein phosphorylation. We conclude that the mechanism of hypoxia-induced activation of CaM KIV and CREB phosphorylation is nuclear Ca(2+) influx mediated. We speculate that nuclear Ca(2+) influx is a key step that triggers CREB mediated transcription of apoptotic proteins and hypoxic mediated neuronal death.

Effect of hyperoxia on cortical neuronal nuclear function and programmed cell death mechanisms.

There is growing concern over detrimental neurologic effects to human newborns caused by increased inspired oxygen concentrations. We hypothesize that hyperoxia (FiO(2)>0.95) results in increased high-affinity Ca(2+)-ATPase activity, Ca(2+)-influx, and proapoptotic protein expression in cortical neuronal nuclei of newborn piglets. Neuronal cerebral energy metabolism was documented by determining ATP and phosphocreatine levels. Neuronal nuclear conjugated dienes and fluorescent compounds were measured as indices of lipid peroxidation. High-affinity Ca(2+)-ATPase activity and ATP-dependent Ca(2+)-influx were determined to document neuronal nuclear membrane function. Hyperoxia resulted in increases in lipid peroxidation, high-affinity Ca(2+)-ATPase activity, ATP-dependent Ca(2+)-influx, and Bax/Bcl-2 ratio in the cortical neuronal nuclei of newborn piglets. We conclude that hyperoxia results in modification of neuronal nuclear membrane function leading to increased nuclear Ca(2+)-influx, and propose that hyperoxia-induced increases in intranuclear Ca(2+) activates the Ca(2+)/calmodulin-dependent protein kinase pathway, triggering increased CREB protein-mediated apoptotic protein expression in hyperoxic neurons.

Cryopreservation of adherent neuronal networks.

Neuronal networks have been widely used for neurophysiology, drug discovery and toxicity testing. An essential prerequisite for future widespread application of neuronal networks is the development of efficient cryopreservation protocols to facilitate their storage and transportation. Here is the first report on cryopreservation of mammalian adherent neuronal networks. Dissociated spinal cord cells were attached to a poly-d-lysine/laminin surface and allowed to form neuronal networks. Adherent neuronal networks were embedded in a thin film of collagen gel and loaded with trehalose prior to transfer to a freezing medium containing DMSO, FBS and culture medium. This was followed by a slow rate of cooling to -80 degrees C for 24 h and then storage for up to 2 months in liquid nitrogen at -196 degrees C. The three components: DMSO, collagen gel entrapment and trehalose loading combined provided the highest post-thaw viability, relative to individual or two component protocols. The post-thaw cells with this protocol demonstrated similar neuronal and astrocytic markers and morphological structure as those detected in unfrozen cells. Fluorescent dye FM1-43 staining revealed active recycling of synaptic vesicles upon depolarizing stimulation in the post-thaw neuronal networks. These results suggest that a combination of DMSO, collagen gel entrapment and trehalose loading can significantly improve conventional slow-cooling methods in cryopreservation of adherent neuronal networks.