Biological sex and hormonal contraceptive associations with drug cue reactivity in cannabis use disorder.

Biological sex differences in Cannabis Use Disorder (CUD) progression, cannabis withdrawal severity, and pharmacotherapy response have been reported, suggesting that CUD mechanisms may differ by sex. Drug cue reactivity is an established predictor of drug use behavior, but the literature on sex differences in drug cue reactivity is mixed, including in CUD. One possible moderator of sex differences in drug cue reactivity is hormonal contraceptive (HC) use. The aim of the present study was to test whether sex differences in neural cannabis cue reactivity and craving varied by female HC use in a CUD sample. As part of a larger study, 152 adults reporting frequent cannabis use completed a drug cue reactivity task during electrocenphalogram recording. Late positive potential (LPP) amplitude modulation by cannabis cues was used to measure neural cue reactivity. Craving after the cue reactivity task was also assessed. Males (n = 74) and naturally-cycling females (n = 26), who did not differ from each other, showed significantly greater LPP enhancement to cannabis vs. neutral cues compared to HC-using females (n = 52), an effect mostly driven by neutral cues. Craving was significantly higher in naturally-cycling but not HC-using females compared to males, but only in covariate-unadjusted analyses. Exploratory analyses of HC and menstrual phase characteristics indicate a progesterone-related mechanism may underlie HC effects on cannabis cue reactivity. The present study's results suggest that mixed findings on drug cue reactivity sex differences may be due to variability in HC use, which has implications for sex-specific models of CUD progression and treatment.

Decomposing the late positive potential to cannabis cues in regular cannabis users: A temporal-spatial principal component analysis.

Cannabis use disorder (CUD) is increasing in the United States, yet, specific neural mechanisms of CUD are not well understood. Disordered substance use is characterized by heightened drug cue incentive salience, which can be measured using the late positive potential (LPP), an event-related potential (ERP) evoked by motivationally significant stimuli. The drug cue LPP is typically quantified by averaging the slow wave's scalp-recorded amplitude across its entire time course, which may obscure distinct underlying factors with differential predictive validity; however, no study to date has examined this possibility. In a sample of 105 cannabis users, temporo-spatial Principal Component Analysis was used to decompose cannabis cue modulation of the LPP into its underlying factors. Acute stress was also inducted to allow for identification of specific cannabis LPP factors sensitive to stress. Factor associations with CUD severity were also explored. Eight factors showed significantly increased amplitudes to cannabis images relative to neutral images. These factors spanned early (~372 ms), middle (~824 ms), and late (>1000 ms) windows across frontal, central, and parietal-occipital sites. CUD phenotype individual differences were primarily associated with frontal, middle/late latency factor amplitudes. Acute stress effects were limited to one early central and one late frontal factor. Taken together, results suggest that the cannabis LPP can be decomposed into distinct, temporal-spatial factors with differential responsivity to acute stress and CUD phenotype variability. Future individual difference studies examining drug cue modulation of the LPP should consider (1) frontalcentral poolings in addition to conventional central-parietal sites, and (2) later LPP time windows.

The interactive effects of AS and trauma exposure on suicide capability and suicide risk.

BACKGROUND: Trauma exposure has been linked with heightened suicide risk purportedly through habituation to threatening stimuli, thereby reducing fear of suicide. However, no research has examined variables that may influence this process. Anxiety sensitivity (AS) is one cognitive-affective factor that may strengthen the relationship between trauma exposure and reduced fear of suicide by amplifying traumatic reactivity. The present study evaluated this by examining the interaction of AS and trauma exposure type (e.g., direct vs. witnessed) predicting fear of suicide and self-reported suicide risk. METHODS: Participants (n = 124) were recruited for a long-term (∼3-4 years) follow-up after participation in a clinical trial targeting suicide risk factors and were asked to complete self-report measures of trauma history, AS, fear of suicide, and suicide risk. RESULTS: Significant interactions emerged such that a greater number of direct traumasexperienced predicted lower fear of suicide and greater suicide risk among those with greater AS. The interactive effect of witnessed traumas and AS predicting suicidality was insignificant. Results remained even after including relevant covariates. DISCUSSION: The current findings suggest that AS augments the effects of repeated trauma exposure on fear of suicide and suicide risk. It is plausible these painful and provocative events are more potent among those with high AS due to the amplification of traumatic affective responses, though future research examining the longitudinal relations is needed to confirm this process.

Neurophysiological error processing and addiction self-awareness correlates of reduced insight in cannabis use disorder.

BACKGROUND AND AIMS: Cannabis use disorder (CUD) prevalence has increased, while perceived risks of cannabis use and CUD treatment need have decreased. Chronic cannabis use may also impair the neural and behavioral mechanisms of insight, further hampering treatment-seeking. This study aimed to measure whether CUD is characterized by reduced self-monitoring in drug-related contexts (objectively-assessed insight), subserved by functional neural abnormalities in error-processing and manifested clinically as decreased awareness of the need to change. DESIGN: Case-control laboratory study was used. SETTING: University setting was in Alabama, USA. PARTICIPANTS: There were 42 CUD participants and 47 age-, sex-, and nicotine use-matched controls. MEASUREMENTS: Participants completed a probabilistic choice task, adapted for the first time for CUD, in which they selected pleasant, unpleasant, neutral, and cannabis-related images according to their preference. Reduced versus accurate insight was operationalized as the correspondence between self-reported and actual most chosen image type. Neurophysiological error-processing during an inhibitory control task was recorded using electroencephalography. Participants with CUD completed measures of cannabis problem recognition and motivation to change. FINDINGS: Compared with controls, the CUD group made significantly more cannabis selections on the choice task (mean difference [MD] = 8.11, 95% confidence interval [CI] [4.88 11.35], p < 0.001) and had significantly reduced insight into cannabis choice (odds ratio [OR] = 9.69, 95% CI [1.06 88.65], p = 0.04). CUD participants with reduced insight on the choice task had significantly decreased neurophysiological reactivity to errors on the inhibitory control task (error-related negativity) compared with CUD participants with accurate insight (MD = 2.64 µV, 95% CI [0.74 µV 4.54 µV], p = 0.008) and controls (MD = 4.05 µV, 95% CI [1.29 µV 6.80 µV], p = 0.005). Compared with CUD participants with accurate insight on the choice task, CUD participants with reduced insight reported significantly less agreement that they had a cannabis problem (MD = -5.06, 95% CI [-8.49-1.62], p = 0.003). CONCLUSIONS: People with CUD who show reduced insight on a drug-related choice task may also have decreased early neural error-processing and less cannabis problem recognition.

Physiological stress modulation of neural drug cue reactivity in cannabis use disorder.

OBJECTIVE: Rates of daily cannabis use and cannabis use disorder (CUD) are increasing in the United States. Prominent addiction theories suggest that stress potentiation of drug cue incentive salience is a central feature of disordered versus recreational drug use, which has been corroborated using a neurophysiological index of drug cue incentive salience (i.e., the late positive potential [LPP]) in adults who regularly use cannabis. However, the mechanism through which acute stress potentiates the cannabis LPP in CUD is unclear. METHOD: To address this gap, cannabis LPPs were measured before and after a stress induction in 95 adults who regularly use cannabis. Physiological (hypothalamic-pituitary-adrenal [HPA] axis, heart rate, skin conductance) and subjective stress reactivity were also measured. RESULTS: Based on prior work, we hypothesized that cortisol stress reactivity would predict poststress cannabis LPP enhancement in more severe CUD. The hypothesis was supported and specific to HPA-axis versus autonomic or subjective stress reactivity. CONCLUSIONS: Acute stress potentiation of the cannabis LPP, likely via HPA-axis activation, may be a biomarker of heavy/disordered cannabis use in adults who regularly use cannabis. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Temporal stability of neurophysiological drug cue reactivity before and after acute stress in cannabis users: A test of incentive sensitization.

BACKGROUND: Given increasing rates of Cannabis Use Disorder (CUD), objective measures are needed that can reliably index risk and track cannabis use progression. Based on incentive sensitization models, neurophysiological reactivity to cannabis cues, measured with the electroencephalography-recorded late positive potential (LPP), may be a candidate biomarker. To serve as such, the cannabis cue-elicited LPP must demonstrate adequate retest reliability and sensitivity to cannabis use change. Moreover, incentive sensitization theory suggests that state-level contextual variables, such as acute stress, can impact drug cue reactivity. Therefore, the present study evaluated the three-month retest reliability of the cannabis cue-elicited LPP, recorded before and after a laboratory stress induction, as well as its sensitivity to cannabis use change. METHOD: Cannabis and neutral cue-elicited LPPs were measured in 102 adults reporting frequent cannabis use (86 % with current CUD) before and after an acute stress induction at two lab visits three-months apart. Physiological and subjective stress reactivity were also measured. RESULTS: Manipulation checks confirmed expected cannabis cue and acute stress effects. Cannabis cue-elicited LPP amplitudes showed significant three-month retest reliability of poor-to-fair through moderate-to-good size. Change in cannabis use frequency significantly predicted change in cannabis cue-elicited LPP amplitudes, particularly at post-stress. CONCLUSION: Consistent with incentive sensitization models of addiction, the cannabis cue-elicited LPP demonstrated trait-like, moderate three-month stability and responsivity to change in cannabis use behavior. Greater predictive validity of the post-stress LPP may arise through kindling effects of acute stress on incentive salience-related neural activity, which should be explored in future studies.

Impact of acute stress on neural indices of positive and negative reinforcement processing in cannabis users.

OBJECTIVE: Chronic cannabis use is maintained in part through dysregulated stress and reward response systems. Specifically, stress-related negative affect is thought to act as a salient motivator for chronic substance use. Models of addiction posit that the transition from positive to negative reinforcement motives for substance use is a key mechanism of disordered use. However, research in substance-using samples has not assessed stress-related neural processing of both positive and negative reinforcement. METHOD: Therefore, the present study utilized laboratory stress induction to examine how stress affects the reward positivity, an event-related potential sensitive to both positive (RewP) and negative (relief-RewP) reinforcement, in 87 cannabis users (58.10% female, Mage = 19.40) varying in cannabis use disorder (CUD) severity and, as part of larger study aims, history of traumatic brain injury (TBI). We predicted greater CUD severity would be associated with a blunted RewP and enhanced relief-RewP, particularly after stress induction, independent of TBI status. RESULTS: Findings indicated that CUD severity was not associated with RewP/relief-RewP amplitude regardless of acute stress. Exploratory analyses revealed, however, that among those with history of TBI +, CUD severity was associated with greater stress-elicited blunting of the RewP and enhancement of the relief-RewP. CONCLUSION: Although initial findings contradict current allostatic models of addiction, exploratory findings suggest that history of TBI, and potentially other confounding variables related to increased risk of TBI experience, may influence the extent to which stressful experiences modulate the neurophysiology of both positive and negative reinforcement reward processing in CUD. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Impact of a computerized distress intolerance intervention on electrocortical reactivity to cannabis and threat cues: A randomized controlled trial.

OBJECTIVE: Given increasing rates of daily cannabis use and Cannabis Use Disorder (CUD) in the United States, it is imperative to understand CUD mechanisms in high-risk groups. Cannabis users with high distress intolerance (DI) are at elevated risk for severe and chronic CUD, but neural mechanisms linking CUD and DI are unknown. Cross-sectional data suggests that acute stress modulation of the cannabis and threat cue-elicited late positive potential (LPP), a neurophysiological marker of motivated attention, are possible mechanisms. However, longitudinal research is needed to clarify the roles of these elicited LPPs in CUD maintenance. METHOD: Sixty cannabis users with high DI were randomized a brief computerized intervention targeting DI or a control intervention. Elicited LPPs were measured before and after a stressor at baseline and postintervention. Intervention effects on stress modulation of the cannabis and threat LPPs, as well as their prospective associations with CUD, were assessed. RESULTS: Elicited LPPs did not significantly change in either intervention group. Acute stress enhancement of the cannabis LPP predicted more severe CUD and greater chronicity at 4-month follow-up. CONCLUSIONS: Cannabis and threat LPPs were not altered by a brief DI intervention despite improvement in DI and cannabis use outcomes. Given that acute stress enhancement of the cannabis LPP predicted poorer CUD outcome, it may be a fruitful intervention target in distress intolerant cannabis users. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Stoichiometry-Controlled Reversible Lithiation Capacity in Nanostructured Silicon Nitrides Enabled by in Situ Conversion Reaction.

In modern Li-based batteries, alloying anode materials have the potential to drastically improve the volumetric and specific energy storage capacity. For the past decade silicon has been viewed as a "Holy Grail" among these materials; however, severe stability issues limit its potential. Herein, we present amorphous substoichiometric silicon nitride (SiNx) as a convertible anode material, which allows overcoming the stability challenges associated with common alloying materials. Such material can be synthesized in a form of nanoparticles with seamlessly tunable chemical composition and particle size and, therefore, be used for the preparation of anodes for Li-based batteries directly through conventional slurry processing. Such SiNx materials were found to be capable of delivering high capacity that is controlled by the initial chemical composition of the nanoparticles. They exhibit an exceptional cycling stability, largely maintaining structural integrity of the nanoparticles and the complete electrodes, thus delivering stable electrochemical performance over the course of 1000 charge/discharge cycles. Such stability is achieved through the in situ conversion reaction, which was herein unambiguously confirmed by pair distribution function analysis of cycled SiNx nanoparticles revealing that active silicon domains and a stabilizing Li2SiN2 phase are formed in situ during the initial lithiation.

Diminished responses to external threat as a possible link between chronic/severe posttraumatic stress disorder and suicide.

OBJECTIVE: Posttraumatic stress disorder (PTSD) is linked with suicide attempt history, but the neurobehavioral mechanisms explaining this association are unclear. The narrative review presented here proposes that blunted neurobehavioral responses to acute external threat represent one pathway via which chronic, severe, and/or multitrauma PTSD may increase risk for a suicide attempt among those with suicidal desire. METHOD: A brief review of theoretical perspectives on diminished responding to external threats in suicide and PTSD is provided (Part 1) followed by the presentation of existing evidence using neurophysiological (Part 2), startle reflex and autonomic (Part 3), and behavioral (Part 4) measures of threat reactivity among individuals with past suicide attempts and PTSD. RESULTS: Findings generally support the proposal that blunted neurobehavioral responses to threat may link chronic and severe PTSD with suicide, though more evidence from all levels of analysis is needed. Additional questions also remain, including the relative influences of multiple traumatic events and PTSD severity as well as the directionality of the associations among PTSD, suicide, and blunted threat responses. CONCLUSIONS: Blunted neurobehavioral responses to external threats appear to be one plausible mechanism via which chronic, severe, and/or multitrauma PTSD may elevate risk for a suicide attempt when combined with suicidal desire. Future research should seek to use intensive longitudinal designs to evaluate the directionality of relations between PTSD, suicide, and threat reactivity across multiple levels of analysis, including the behavioral freeze response. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A longitudinal investigation of trauma-specific rumination and PTSD symptoms: The moderating role of interpersonal trauma experience.

BACKGROUND: Interpersonal trauma (IPT) is one of the most commonly reported types of traumatic experiences and has the greatest likelihood of resulting in a diagnosis of posttraumatic stress disorder (PTSD). Relative to other types of trauma, victims of IPT report greater trauma-specific rumination, whereby they focus on negative consequences of the trauma on their life. Theoretical and empirical work suggest trauma-specific rumination leads to elevated posttraumatic stress symptoms (PTSS); however, there has been a dearth of research examining how trauma type may impact this association. Therefore, the current longitudinal study examined how the experience of IPT moderates the relationship between trauma-specific rumination and later PTSS. METHOD: Participants (N = 204) enrolled in a clinical trial completed self-report measures of trauma experience, trauma-specific rumination, and PTSS at baseline and 1-month follow-up appointments. RESULTS: Results revealed that IPT moderated the relationship between baseline rumination and 1-month trauma symptoms, even after covarying for participant age and sex, treatment condition, negative affect, and number of previously experienced traumas. Further, this moderation effect was specific to the PTSD numbing cluster. LIMITATIONS: Major limitations include measurement of PTSS via PCL-C rather than the PCL-5, as well as a limited sample size, precluding moderation analyses of other trauma types. CONCLUSIONS: The current study provides novel findings demonstrating specificity of index trauma type in the longitudinal relationship between rumination and PTSS. Future work is needed to examine how IPT impacts the development of pathways between rumination and PTSS.

Cognitive reappraisal and the association between depressive symptoms and perceived social support among older adults.

OBJECTIVES: There is an association between depression and diminished social support; indeed, interpersonal dysfunction is often a central feature of depression. The purpose of this study is to examine the role that an emotion regulation (ER) strategy, cognitive reappraisal, plays in influencing the association between depressive symptoms and perceived social support in older adults. METHOD: Data for this cross-sectional study come from a community-based survey of older adults (60+, N = 910). We examined the effects of depressive symptoms and cognitive reappraisal on perceived social support. We then examined the potential moderating role of cognitive reappraisal on the association between depressive symptoms and perceived social support. RESULTS: Depressive symptoms were associated with lower levels of perceived social support. Cognitive reappraisal was associated with higher levels of perceived social support. Cognitive reappraisal moderated the negative consequences of depressive symptoms on perceived social support. Whereas depressive symptoms had a negative effect on perceived social support, the negative effect was greater for those with lower levels of cognitive reappraisal compared to those with higher levels of cognitive reappraisal. DISCUSSION: ER strategies may play a role in attenuating the negative consequences of depressive symptoms on social support in older age. It may be possible to help individuals maintain social support in later life, even in the face of mental health challenges, if they cultivate ER skills.

Development and validation of a cannabis cue stimulus set.

Regular cannabis use and cannabis use disorder (CUD) have become increasingly prevalent in the United States over the past two decades. Theory and empirical data suggest that the incentive salience of cannabis cues is important to the development and chronicity of CUD. Cannabis cue incentive salience is often assessed with a cannabis cue reactivity paradigm wherein cannabis-related and neutral images are presented. However, prior cannabis cue reactivity studies have been limited by the use of heterogeneous stimuli that were not properly characterized across motivational/affective characteristics, physical image attributes, or non-cannabis-related salient image features (e.g., human presence, face visibility). In order to increase standardization and flexibility of future cannabis cue reactivity tasks, the aim of the present study was to develop and validate a cannabis cue and matched neutral image database comprised of motivational/affective ratings as well as physical image attributes. 234 regular cannabis users varying in primary use method (i.e., bowl, blunt/joint, bong, vaporizer) made motivational (i.e., urge to smoke cannabis) and affective (i.e., arousal, valence) ratings of cannabis-related and neutral images matched on salient, non-cannabis-related features. Physical features (hue, saturation, value) of each image were also analyzed. Motivational/affective ratings of cannabis-related and neutral images differed as expected, and cannabis use frequency and cannabis craving correlations with cannabis image ratings generally supported stimulus validity. Motivational/affective ratings did not significantly differ across cannabis use method-specific images. This database may be a useful tool for future behavioral and neuroscience research on cannabis cue reactivity.

Distress intolerance mediates attentional control on posttraumatic stress symptoms: Evidence from two clinical samples.

Theoretical models emphasize the importance of both affective and cognitive risk factors in the development of posttraumatic stress symptoms (PTSS). Two such factors predicting PTSS have been studied extensively: distress intolerance (DI) - an affective factor indicative of the ability to tolerate negative affective states - and attentional control (AC), a cognitive factor reflecting the ability to flexibly shift and maintain attention to goal-relevant tasks. Previous work primarily highlights the independent contributions of DI and AC and their interaction to predict PTSS. Some models, however, suggest a mediational pathway such that AC indirectly affects PTSS via diminished DI. The current paper addressed this gap by first attempting to replicate prior findings, while also exploring this mediation model. Results were examined in two clinical samples - a trauma-exposed sample of adults (study 1; N = 73) and trauma-exposed treatment-seeking adults (study 2; N = 204). Results partially supported our hypotheses; both studies failed to replicate prior moderation findings, but our mediational hypothesis was supported in both samples. Low AC appears to decrease an individual's tolerance for distressing situations, which in turn increases the severity of PTSS. Results suggest that PTSD treatments may benefit by incorporating components of AC, DI, or a combination of the two to mitigate PTSS. Taken together, this study provides a novel examination of how cognitive and affective risk factors, namely AC and DI, work in tandem to increase PTSS.

Data-Driven Investigation of Monosilane and Ammonia Co-Pyrolysis to Silicon-Nitride-Based Ceramic Nanomaterials.

With its high strength, high thermal stability, low density, and high electrical resistance, silicon-nitride-based ceramics have been widely used as gate insulating layers, oxidation masks, and passivation layers. Employing SiN nanomaterials in anode applications also improves rate performances and cycling stability of the lithium-ion batteries. However, a fundamental understanding of the SiN synthetic process remains elusive. SiN gas-phase synthesis can be tailored with a comprehensive understanding of the underlying thermodynamics. In comparison to the characterization data available for solid-state SiN materials, high-level theoretical studies on gas-phase materials possessing Si-N bonds and comprehensive investigation of the SiN chemistry, particularly for nanoclusters, are very uncommon. Thus, we performed a theoretical study of Si and SiN alloy acyclic hydrides and polycyclic clusters to predict electronic structures and thermochemistry using quantum chemical calculation and statistical thermodynamics. Electronic properties by way of highest and lowest occupied molecular orbital energy gap and natural bonding orbitals analysis were calculated to explore the influence of elemental composition and geometry on the stability. Our studies provide characteristic data of SiN species for a data-driven approach to map the design space for discovery of novel silicon-nitride-based ceramic materials for advanced electronic and coating applications.

Development of the Adult ECMO Specialist Certification Examination.

The American Society of Extracorporeal Technology Board of Directors, consistent with the American Society of Extracorporeal Technology's safe patient care improvement mission, charged the International Board of Blood Management to write a knowledge and skill certification examination for healthcare personnel employed as adult extracorporeal membrane oxygenation (ECMO) specialists. Nineteen nationally recognized ECMO subject-matter experts were selected to complete the examination development. A job analysis was performed, yielding a job description and examination plan focused on 16 job categories. Multiple-choice test items were created and validated. Qualified ECMO specialists were identified to complete a pilot examination and both pre- and post-examination surveys. The examination item difficulty and candidate performance were ranked and matched using Rasch methodology. Candidates' examination scores were compared with their profession, training, and experience as ECMO specialists. The 120-item pilot examination form ranked 76 ECMO specialist candidates consistent with their licensure, ECMO training, and clinical experience. Forty-three registered nurses, 28 registered respiratory therapists, four certified clinical perfusionists, and one physician assistant completed the pilot examination process. Rasch statistics revealed examination reliability coefficients of .83 for candidates and .88 for test items. Candidates ranked the appropriateness for examination items consistent with the item content, difficulty, and their personal examination score. The pilot examination pass rate was 80%. The completed examination product scheduled for enrollment in March 2020 includes 100 verified test items with an expected pass rate of 84% at a cut score of 67%. The online certification examination based on a verified job analysis provides an extramural assessment that ranks minimally prepared ECMO specialists' knowledge, skills, and abilities (KSA) consistent with safe ECMO patient care and circuit management. It is anticipated that ECMO facilities and ECMO service providers will incorporate the certification examination as part of their process improvement, safety, and quality assurance plans.

Emotion dysregulation as a maintenance factor for posttraumatic stress symptoms: The role of anxiety sensitivity.

OBJECTIVES: The current study tested whether emotion dysregulation, assessed by the Difficulties in Emotion Regulation Scale (DERS), would predict posttraumatic stress symptoms (PTSS) through anxiety sensitivity (AS). Alternate cognitive-affective mediators (i.e., distress tolerance and intolerance of uncertainty) were explored. METHOD: A total of 259 trauma-exposed community members (ages averaging 37.39; evenly distributed by gender) from a larger clinical trial targeting suicide risk factors completed a clinical interview and self-report questionnaires at baseline, Week-3, and 1-month follow-up appointments. RESULTS: AS at Week 3 significantly mediated the relationship between initial emotion dysregulation and 1-month follow-up posttraumatic stress symptoms (PTSS) after controlling for condition and baseline symptoms (ß = .07; standard error = 0.03; 95% confidence interval = [0.01, 0.14]). Effects held for one out of six emotion dysregulation subscales. Distress tolerance and intolerance of uncertainty were not significant mediators (ps > .05). CONCLUSIONS: This study demonstrates that emotion dysregulation may confer maintenance of PTSS through AS. Findings highlight potentially malleable targets for interventions.

Morphology engineering of silicon nanoparticles for better performance in Li-ion battery anodes.

Amorphous silicon nanoparticles were synthesized through pyrolysis of silane gas at temperatures ranging from 575 to 675 °C. According to the used temperature and silane concentration, two distinct types of particles can be obtained: at 625 °C, spherical particles with smooth surface and a low degree of aggregation, but at a higher temperature (650 °C) and lower silane concentration, particles with extremely rough surfaces and high degree of aggregation are found. This demonstrates the importance of the synthesis temperature on the morphology of silicon particles. The two types of silicon nanoparticles were subsequently used as active materials in a lithium half cell configuration, using LiPF6 in an alkylcarbonate-based electrolyte, in order to investigate the impact of the particles morphology on the cycling performances of silicon anode material. The difference in morphology of the particles resulted in different volume expansions, which impacts the solid electrolyte interface (SEI) formation and, as a consequence, the lifetime of the electrode. Half-cells fabricated from spherical particles demonstrated almost 70% capacity retention for over 300 cycles, while the cells made from the rough, aggregated particles showed a sharp decrease in capacity after the 20th cycle. The cycling results underline the importance of Si particle engineering and its influence on the lifetime of Si-based materials.

Transport While on Extracorporeal Membrane Oxygenation Support.

Extracorporeal membrane oxygenation (ECMO) support for severe acute respiratory failure has been increasing. Evidence suggests that higher volume centers have better outcomes, leading to a need for specialized ECMO transport teams. The inherent nature of the prehospital environment adds an additional layer of complexity; however, the experience of multiple centers has demonstrated that cannulating and transporting a patient on ECMO can be performed safely. The purpose of this review article is to discuss the state of knowledge with respect to ECMO transport with special emphasis given to how to actually undertake such complex transports.