Towards a realistic prediction of catalyst durability from liquid half-cell tests.

Liquid half-cell measurements provide a convenient laboratory method for determining relevant parameters of electro-catalysts applied in e.g. polymer electrolyte membrane fuel cells. While these measurements may be effective in certain contexts, their applicability to real-world systems, such as single-cells in a membrane electrode assembly (MEA) configuration, is not always clear. This is particularly true when assessing the stability of these systems through accelerated stress tests (ASTs). Due to different electrode compositions and operating conditions, nanoscale degradation proceeds differently. Nevertheless, given the high demands of MEA measurements in terms of time, testing equipment complexity, and amount of catalyst material, application-relevant predictions of catalyst durability from liquid half-cell tests are highly desirable. This study combines electrochemical and nanoparticle analysis based on transmission electron microscopy to conduct a typical voltage cycling AST for rotating disc electrode (RDE) measurements, showing that the loss of the electrochemically active surface area (ECSA) of the used Pt/Vulcan catalyst is strongly enhanced at 80 °C compared to room temperature, which goes along with increased nanoparticle coarsening. Additionally, a high ionomer/carbon mass ratio (I/C = 0.7) accelerates the ECSA loss, and further investigations of its influence suggest a combination of several factors, including the high local proton concentration and the presence of adsorbing anions. At the same temperature (80 °C) and I/C ratio (0.7), the ECSA loss vs. AST cycle number of the Pt/Vulcan catalyst is essentially identical for a voltage cycling AST conducted in either an RDE half-cell or an MEA configuration, suggesting that liquid electrolyte half-cell based ASTs can provide application-relevant results. Thus, our study points out a way for predicting the stability of electro-catalysts in MEAs based on RDE experiments that require less specialized equipment and only µg-quantities of catalysts.

FUSE-ML: development and external validation of a clinical prediction model for mid-term outcomes after lumbar spinal fusion for degenerative disease.

BACKGROUND: Indications and outcomes in lumbar spinal fusion for degenerative disease are notoriously heterogenous. Selected subsets of patients show remarkable benefit. However, their objective identification is often difficult. Decision-making may be improved with reliable prediction of long-term outcomes for each individual patient, improving patient selection and avoiding ineffective procedures. METHODS: Clinical prediction models for long-term functional impairment [Oswestry Disability Index (ODI) or Core Outcome Measures Index (COMI)], back pain, and leg pain after lumbar fusion for degenerative disease were developed. Achievement of the minimum clinically important difference at 12 months postoperatively was defined as a reduction from baseline of at least 15 points for ODI, 2.2 points for COMI, or 2 points for pain severity. RESULTS: Models were developed and integrated into a web-app ( https://neurosurgery.shinyapps.io/fuseml/ ) based on a multinational cohort [N = 817; 42.7% male; mean (SD) age: 61.19 (12.36) years]. At external validation [N = 298; 35.6% male; mean (SD) age: 59.73 (12.64) years], areas under the curves for functional impairment [0.67, 95% confidence interval (CI): 0.59-0.74], back pain (0.72, 95%CI: 0.64-0.79), and leg pain (0.64, 95%CI: 0.54-0.73) demonstrated moderate ability to identify patients who are likely to benefit from surgery. Models demonstrated fair calibration of the predicted probabilities. CONCLUSIONS: Outcomes after lumbar spinal fusion for degenerative disease remain difficult to predict. Although assistive clinical prediction models can help in quantifying potential benefits of surgery and the externally validated FUSE-ML tool may aid in individualized risk-benefit estimation, truly impacting clinical practice in the era of "personalized medicine" necessitates more robust tools in this patient population.

Patient and operative factors associated with unanticipated intensive care admission and outcomes following posterior fossa decompressions in children: A retrospective study.

INTRODUCTION: Posterior fossa decompression for Chiari I Malformation is a common pediatric neurosurgical procedure. We sought to identify the impact of anesthesia-related intraoperative complications on unanticipated admission to the intensive care unit and outcomes following posterior fossa decompression. METHODS: Medical records of all patients <18 years who underwent surgery for Chiari I malformation between 1/1/09 and 1/31/21 at the Ann & Robert H. Lurie Children's Hospital of Chicago were included. Records were reviewed for patient characteristics, anesthesia-related intraoperative complications, postoperative complications, and surgical outcomes. The primary outcome was the incidence of unanticipated admission to the intensive care unit, and the primary variable of interest was an anesthesia-related intraoperative complication. Patient, surgical characteristics, and year of surgery were also compared between patients with and without an unanticipated admission to the intensive care unit, and a multi-variable adjusted estimate of odds of unanticipated admission to the intensive care unit admission following an anesthesia-related intraoperative complication was performed. Secondary outcomes included anesthesia factors associated with an anesthesia-related intraoperative event, and postoperative complications and surgical outcomes between patients admitted to the intensive care unit and those who were not. RESULTS: Two hundred ninety-six patients with Chiari I Malformation were identified. Clinical characteristics associated with an unanticipated admission to the intensive care unit were younger age, American Society of Anesthesiologist (ASA) physical status >2 and an anesthesia-related intraoperative complication. 29 anesthesia-related intraoperative complications were observed in 25 patients (8.4%). Two of 25 patients (8%) with an anesthesia-related intraoperative complication compared with 3 of 271 (1%) patients without anesthesia-related intraoperative complication had an unanticipated admission to the intensive care unit, odds ratio 7.8 (95% CI 1.2-48.8, p = .010). When adjusted for age, sex, ASA physical status, presenting symptoms, concomitant syringomyelia, previous decompression surgery and year of surgery, the odds ratio for an unanticipated admission to the intensive care unit following an anesthesia-related intraoperative complication was 5.9 (95% CI 0.51-59.6, p = .149). There were no differences in surgical outcomes between patients with or without an unanticipated admission to the intensive care unit. CONCLUSION: Our study demonstrates that although anesthesia-related intraoperative complications during posterior fossa decompression are infrequent, they are associated with an increased risk of an unanticipated admission to the intensive care unit.

Safety of antifibrinolytics in 6583 pediatric patients having craniosynostosis surgery: A decade of data reported from the multicenter Pediatric Craniofacial Collaborative Group.

BACKGROUND: Antifibrinolytics such as tranexamic acid and epsilon-aminocaproic acid are effective at reducing blood loss and transfusion in pediatric patients having craniofacial surgery. The Pediatric Craniofacial Collaborative Group has previously reported low rates of seizures and thromboembolic events (equal to no antifibrinolytic given) in open craniofacial surgery. AIMS: To query the Pediatric Craniofacial Collaborative Group database to provide an updated antifibrinolytic safety profile in children given that antifibrinolytics have become recommended standard of care in this surgical population. Additionally, we include the population of younger infants having minimally invasive procedures. METHODS: Patients in the Pediatric Craniofacial Collaborative Group registry between June 2012 and March 2021 having open craniofacial surgery (fronto-orbital advancement, mid and posterior vault, total cranial vault remodeling, intracranial LeFort III monobloc), endoscopic cranial suture release, and spring mediated cranioplasty were included. The primary outcome is the rate of postoperative complications possibly attributable to antifibrinolytic use (seizures, seizure-like activity, and thromboembolic events) in infants and children undergoing craniosynostosis surgery who did or did not receive antifibrinolytics. RESULTS: Forty-five institutions reporting 6583 patients were included. The overall seizure rate was 0.24% (95% CI: 0.14, 0.39%), with 0.20% in the no Antifibrinolytic group and 0.26% in the combined Antifibrinolytic group, with no statistically reported difference. Comparing seizure rates between tranexamic acid (0.22%) and epsilon-aminocaproic acid (0.44%), there was no statistically significant difference (odds ratio = 2.0; 95% CI: 0.6, 6.7; p = .257). Seizure rate was higher in patients greater than 6 months (0.30% vs. 0.18%; p = .327), patients undergoing open procedures (0.30% vs. 0.06%; p = .141), and syndromic patients (0.70% vs. 0.19%; p = .009). CONCLUSIONS: This multicenter international experience of pediatric craniofacial surgery reports no increase in seizures or thromboembolic events in those that received antifibrinolytics (tranexamic acid and epsilon-aminocaproic acid) versus those that did not. This report provides further evidence of antifibrinolytic safety. We recommend following pharmacokinetic-based dosing guidelines for administration.

H2 Evolution from Electrocatalysts with Redox-Active Ligands: Mechanistic Insights from Theory and Experiment vis-à-vis Co-Mabiq.

Electrocatalytic hydrogen production via transition metal complexes offers a promising approach for chemical energy storage. Optimal platforms to effectively control the proton and electron transfer steps en route to H2 evolution still need to be established, and redox-active ligands could play an important role in this context. In this study, we explore the role of the redox-active Mabiq (Mabiq = 2-4:6-8-bis(3,3,4,4-tetramethlyldihydropyrrolo)-10-15-(2,2-biquinazolino)-[15]-1,3,5,8,10,14-hexaene1,3,7,9,11,14-N6) ligand in the hydrogen evolution reaction (HER). Using spectro-electrochemical studies in conjunction with quantum chemical calculations, we identified two precatalytic intermediates formed upon the addition of two electrons and one proton to [CoII(Mabiq)(THF)](PF6) (CoMbq). We further examined the acid strength effect on the generation of the intermediates. The generation of the first intermediate, CoMbq-H1, involves proton addition to the bridging imine-nitrogen atom of the ligand and requires strong proton activity. The second intermediate, CoMbq-H2, acquires a proton at the diketiminate carbon for which a weaker proton activity is sufficient. We propose two decoupled H2 evolution pathways based on these two intermediates, which operate at different overpotentials. Our results show how the various protonation sites of the redox-active Mabiq ligand affect the energies and activities of HER intermediates.

External validation of a prediction model for pain and functional outcome after elective lumbar spinal fusion.

OBJECTIVE: Patient-reported outcome measures following elective lumbar fusion surgery demonstrate major heterogeneity. Individualized prediction tools can provide valuable insights for shared decision-making. We externally validated the spine surgical care and outcomes assessment programme/comparative effectiveness translational network (SCOAP-CERTAIN) model for prediction of 12-month minimum clinically important difference in Oswestry Disability Index (ODI) and in numeric rating scales for back (NRS-BP) and leg pain (NRS-LP) after elective lumbar fusion. METHODS: Data from a prospective registry were obtained. We calculated the area under the curve (AUC), calibration slope and intercept, and Hosmer-Lemeshow values to estimate discrimination and calibration of the models. RESULTS: We included 100 patients, with average age of 50.4 ± 11.4 years. For 12-month ODI, AUC was 0.71 while the calibration intercept and slope were 1.08 and 0.95, respectively. For NRS-BP, AUC was 0.72, with a calibration intercept of 1.02, and slope of 0.74. For NRS-LP, AUC was 0.83, with a calibration intercept of 1.08, and slope of 0.95. Sensitivity ranged from 0.64 to 1.00, while specificity ranged from 0.38 to 0.65. A lack of fit was found for all three models based on Hosmer-Lemeshow testing. CONCLUSIONS: The SCOAP-CERTAIN tool can accurately predict which patients will achieve favourable outcomes. However, the predicted probabilities-which are the most valuable in clinical practice-reported by the tool do not correspond well to the true probability of a favourable outcome. We suggest that any prediction tool should first be externally validated before it is applied in routine clinical practice. These slides can be retrieved under Electronic Supplementary Material.

Fast Lithium Ion Conduction in Lithium Phosphidoaluminates.

Solid electrolyte materials are crucial for the development of high-energy-density all-solid-state batteries (ASSB) using a nonflammable electrolyte. In order to retain a low lithium-ion transfer resistance, fast lithium ion conducting solid electrolytes are required. We report on the novel superionic conductor Li9 AlP4 which is easily synthesised from the elements via ball-milling and subsequent annealing at moderate temperatures and which is characterized by single-crystal and powder X-ray diffraction. This representative of the novel compound class of lithium phosphidoaluminates has, as an undoped material, a remarkable fast ionic conductivity of 3 mS cm-1 and a low activation energy of 29 kJ mol-1 as determined by impedance spectroscopy. Temperature-dependent 7 Li NMR spectroscopy supports the fast lithium motion. In addition, Li9 AlP4 combines a very high lithium content with a very low theoretical density of 1.703 g cm-3 . The distribution of the Li atoms over the diverse crystallographic positions between the [AlP4 ]9- tetrahedra is analyzed by means of DFT calculations.

Fast Ionic Conductivity in the Most Lithium-Rich Phosphidosilicate Li14SiP6.

Solid electrolytes with superionic conductivity are required as a main component for all-solid-state batteries. Here we present a novel solid electrolyte with three-dimensional conducting pathways based on "lithium-rich" phosphidosilicates with ionic conductivity of σ > 10-3 S cm-1 at room temperature and activation energy of 30-32 kJ mol-1 expanding the recently introduced family of lithium phosphidotetrelates. Aiming toward higher lithium ion conductivities, systematic investigations of lithium phosphidosilicates gave access to the so far lithium-richest compound within this class of materials. The crystalline material (space group Fm3m), which shows reversible thermal phase transitions, can be readily obtained by ball mill synthesis from the elements followed by moderate thermal treatment of the mixture. Lithium diffusion pathways via both tetrahedral and octahedral voids are analyzed by temperature-dependent powder neutron diffraction measurements in combination with maximum entropy method and DFT calculations. Moreover, the lithium ion mobility structurally indicated by a disordered Li/Si occupancy in the tetrahedral voids plus partially filled octahedral voids is studied by temperature-dependent impedance and 7Li NMR spectroscopy.

Impact of preoperative hyponatraemia on paediatric perioperative mortality.

BACKGROUND: Preoperative hyponatraemia is an independent risk factor for postoperative mortality in adults. To our knowledge, this has not been investigated in children. METHODS: Using data from the 2014 and 2015 data sets of the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-P), we conducted a retrospective study of children undergoing surgery. The primary outcome was 30-day all-cause mortality. The secondary outcomes of interest were postoperative seizure within 30 days and prolonged length of stay. To identify any independent association between preoperative hyponatraemia, defined as mild (serum sodium of 131-135 mEq L-1) or severe (≤130 mEq L-1), and death, postoperative seizures, or prolonged length of stay, multivariable logistic regression models were generated. RESULTS: A total of 152 894 patients were identified, and of these 35 291 were included in the final analysis. Preoperative hyponatraemia was present in 5422 patients or 15.4% of the final cohort. There were 432 (0.80%) deaths at 30 days. Compared with patients with a normal preoperative sodium concentration, those with mild (P=0.003; odds ratio [OR]: 1.59; 95% confidence interval [CI]: 1.17-2.18) and severe (P=0.002; OR: 2.16; 95% CI: 1.32-3.54) hyponatraemia had increased rates of death, after adjusting for co-morbidity and procedural complexity. Both mild (P<0.001; OR: 1.53; 95% CI: 1.42-1.65) and severe (P<0.001; OR: 1.51; 95% CI: 1.19-1.93) hyponatraemia were independently associated with prolonged length of stay, after adjusting for relevant co-variates. CONCLUSIONS: This retrospective analysis identified an association between preoperative hyponatraemia and perioperative mortality and length of stay in paediatric patients.

Microbial Community Composition of Tap Water and Biofilms Treated with or without Copper-Silver Ionization.

Copper-silver ionization (CSI) is an in-house water disinfection method primarily installed to eradicate Legionella bacteria from drinking water distribution systems (DWDS). Its effect on the abundance of culturable Legionella and Legionella infections has been documented in several studies. However, the effect of CSI on other bacteria in DWDS is largely unknown. To investigate these effects, we characterized drinking water and biofilm communities in a hospital using CSI, in a neighboring building without CSI, and in treated drinking water at the local water treatment plant. We used 16S rDNA amplicon sequencing and Legionella culturing. The sequencing results revealed three distinct water groups: (1) cold-water samples (no CSI), (2) warm-water samples at the research institute (no CSI), and (3) warm-water samples at the hospital (after CSI; ANOSIM, p < 0.001). Differences between the biofilm communities exposed and not exposed to CSI were less clear (ANOSIM, p = 0.022). No Legionella were cultured, but limited numbers of Legionella sequences were recovered from all 25 water samples (0.2-1.4% relative abundance). The clustering pattern indicated local selection of Legionella types (Kruskal-Wallis, p < 0.001). Furthermore, one unclassified Betaproteobacteria OTU was highly enriched in CSI-treated warm water samples at the hospital (Kruskal-Wallis, p < 0.001).

Singlet Oxygen Reactivity with Carbonate Solvents Used for Li-Ion Battery Electrolytes.

High degrees of delithiation of layered transition metal oxide cathode active materials (NCMs and HE-NCM) for lithium-ion batteries (LIBs) was shown to lead to the release of singlet oxygen, which is accompanied by enhanced electrolyte decomposition. Here, we study the reactivity of chemically produced singlet oxygen with the commonly used cyclic and linear carbonate solvents for LIB electrolytes. On-line gassing analysis of the decomposition of ethylene carbonate (EC) and dimethyl carbonate (DMC) reveals different stability toward the chemical attack of singlet oxygen, which is produced in situ by photoexcitation of the Rose Bengal dye. Ab initio calculations and on-the-fly simulations reveal a possible reaction mechanism, confirming the experimental findings. In the case of EC, hydrogen peroxide and vinylene carbonate (VC) are found to be the products of the first reaction step of EC with singlet oxygen in the reaction cascade of the EC chemical decomposition. In contrast to EC, simulations suggested DMC to be stable in the presence of singlet oxygen, which was also confirmed experimentally. Hydrogen peroxide is detrimental for cycling of a battery. For all known cathode active materials, the potential where singlet oxygen is released is found to be already high enough to electrochemically oxidize hydrogen peroxide. The formed protons and/or water both react with the typically used LiPF6 salt to HF that then leads to transition metal dissolution from the cathode active materials. This study shows how important the chemical stability toward singlet oxygen is for today's battery systems and that a trade-off will have to be found between chemical and electrochemical stability of the solvent to be used.

Pediatric Anesthesiology Fellows' Perception of Quality of Attending Supervision and Medical Errors.

BACKGROUND: Appropriate supervision has been shown to reduce medical errors in anesthesiology residents and other trainees across various specialties. Nonetheless, supervision of pediatric anesthesiology fellows has yet to be evaluated. The main objective of this survey investigation was to evaluate supervision of pediatric anesthesiology fellows in the United States. We hypothesized that there was an indirect association between perceived quality of faculty supervision of pediatric anesthesiology fellow trainees and the frequency of medical errors reported. METHODS: A survey of pediatric fellows from 53 pediatric anesthesiology fellowship programs in the United States was performed. The primary outcome was the frequency of self-reported errors by fellows, and the primary independent variable was supervision scores. Questions also assessed barriers for effective faculty supervision. RESULTS: One hundred seventy-six pediatric anesthesiology fellows were invited to participate, and 104 (59%) responded to the survey. Nine of 103 (9%, 95% confidence interval [CI], 4%-16%) respondents reported performing procedures, on >1 occasion, for which they were not properly trained for. Thirteen of 101 (13%, 95% CI, 7%-21%) reported making >1 mistake with negative consequence to patients, and 23 of 104 (22%, 95% CI, 15%-31%) reported >1 medication error in the last year. There were no differences in median (interquartile range) supervision scores between fellows who reported >1 medication error compared to those reporting ≤1 errors (3.4 [3.0-3.7] vs 3.4 [3.1-3.7]; median difference, 0; 99% CI, -0.3 to 0.3; P = .96). Similarly, there were no differences in those who reported >1 mistake with negative patient consequences, 3.3 (3.0-3.7), compared with those who did not report mistakes with negative patient consequences (3.4 [3.3-3.7]; median difference, 0.1; 99% CI, -0.2 to 0.6; P = .35). CONCLUSIONS: We detected a high rate of self-reported medication errors in pediatric anesthesiology fellows in the United States. Interestingly, fellows' perception of quality of faculty supervision was not associated with the frequency of reported errors. The current results with a narrow CI suggest the need to evaluate other potential factors that can be associated with the high frequency of reported errors by pediatric fellows (eg, fatigue, burnout). The identification of factors that lead to medical errors by pediatric anesthesiology fellows should be a main research priority to improve both trainee education and best practices of pediatric anesthesia.

Multicenter Stratified Comparison of Hospital Costs Between Laparoscopic and Open Colorectal Cancer Resections: Influence of Tumor Location and Operative Risk.

OBJECTIVE: To compare actual 90-day hospital costs between elective open and laparoscopic colon and rectal cancer resection in a daily practice multicenter setting stratified for operative risk. BACKGROUND: Laparoscopic resection has developed as a commonly accepted surgical procedure for colorectal cancer. There are conflicting data on the influence of laparoscopy on hospital costs, without separate analyses based on operative risk. METHODS: Retrospective analyses using a population-based database (Dutch Surgical Colorectal Audit). All elective resections for a T1-3N0-2M0 stage colorectal cancer were included between 2010 and 2012 in 29 Dutch hospitals. Operative risk was stratified for age (<75 years or ≥75 years) and ASA status (I-II/III-IV). Ninety-day hospital costs were measured uniformly in all hospitals based on time-driven activity-based costing. RESULTS: Total 90-day hospital costs ranged from &OV0556;10474 to &OV0556;20865 in the predefined subgroups. For colon cancer surgery (N = 4202), laparoscopic resection was significant less expensive than open resection in all subgroups, savings because of laparoscopy ranged from &OV0556;409 (<75 years ASA I-II) to &OV0556;1932 (≥75 years ASA I-II). In patients ≥75 years and ASA I-II, laparoscopic resection was associated with 46% less mortality (P = 0.05), 41% less severe complications (P < 0.001), 25% less hospital stay (P = 0.013), and 65% less ICU stay (P < 0.001). For rectal cancer surgery (N=2328), all laparoscopic subgroups had significantly higher total hospital costs, ranging from &OV0556;501 (<75 years ASA I-II) to &OV0556;2515 (≥75 years ASA III-IV). CONCLUSIONS: Laparoscopic resection resulted in the largest cost reduction in patients over 75 years with ASA I-II undergoing colonic resection, and the largest cost increase in patients over 75 years with ASA III-IV undergoing rectal resection as compared with an open approach.

Ionic Conductivity Measurements-A Powerful Tool for Monitoring Polyol Reduction Reactions.

The reduction of metal precursors during the polyol synthesis of metal nanoparticles was monitored by ex situ ionic conductivity measurements. Using commonly used platinum precursors (K2PtCl6, H2PtCl6, and K2PtCl4) as well as iridium and ruthenium precursors (IrCl3 and RuCl3), we demonstrate that their reduction in ethylene glycol at elevated temperatures is accompanied by a predictable change in ionic conductivity, enabling a precise quantification of the onset temperature for their reduction. This method also allows detecting the onset temperature for the further reaction of ethylene glycol with HCl produced by the reduction of chloride-containing metal precursors (at ≈120 °C). On the basis of these findings, we show that the conversion of the metal precursor to reduced metal atoms/clusters can be precisely quantified, if the reaction occurs below 120 °C, which also enables a distinction between the stages of metal particle nucleation and growth. The latter is demonstrated by the reduction of H2PtCl6 in ethylene glycol, comparing ionic conductivity measurements with transmission electron microscopy analysis. In summary, ionic conductivity measurements are a simple and straightforward tool to quantify the reduction kinetics of commonly used metal precursors in the polyol synthesis.

Single center cost analysis of single-port and conventional laparoscopic surgical treatment in colorectal malignant diseases.

BACKGROUND AND PURPOSE: Single-port laparoscopy (SPL) is a relatively new technique, used in various procedures. There is limited knowledge about the cost effectiveness and the learning curve of this technique. The primary aim of this study was to compare hospital costs between SPL and conventional laparoscopic resections (CLR) for colorectal cancer; the secondary aim was to identify a learning curve of SPL. METHODS: All elective colorectal cancer SPL and CLR performed in a major teaching hospital between 2011 and 2012 that were registered in the Dutch Surgical Colorectal Audit were included (n = 267). The economic evaluation was conducted from a hospital perspective, and costs were calculated using time-driven activity-based costing methodology up to 90 days after discharge. When looking at SPL only, the introduction year (2011) was compared to the next year (2012). RESULTS: SPL (n = 78) was associated with lower mortality, lower reintervention rates, and more complications as compared to CLR (n = 189); however, none of these differences were statistically significant. A significant shorter operating time was seen in the SPL. Total costs were higher for SPL group as compared to CLR; however, this difference was not statistically significant. For the SPL group, most clinical outcomes improved between 2011 and 2012; moreover, total hospital costs for SPL in 2012 became comparable to CLR. CONCLUSION: No significant differences in financial outcomes between SPL and CLR were identified. After the introduction period, SPL showed similar results as compared to CLR. Conclusions are based on a small single-port group and the conclusions of this manuscript should be an impetus for further research.

Evidence for the Efficacy of Systemic Opioid-Sparing Analgesics in Pediatric Surgical Populations: A Systematic Review.

While a large number of studies has examined the efficacy of opioid-sparing analgesics in adult surgical populations, fewer studies are available to guide postoperative pain treatment in pediatric patients. We systematically reviewed available publications on the use of systemic nonopioid agents for postoperative analgesia in pediatric surgical populations. A comprehensive literature search identified meta-analyses and randomized controlled trials (RCTs) assessing the effects of systemic, nonopioid agents on postoperative narcotic requirements or pain scores in pediatric surgical populations. If a meta-analysis was located, we summarized its results and any RCTs published after it. We located and reviewed 11 acetaminophen RCTs, 1 nonsteroidal anti-inflammatory drug (NSAID) meta-analysis, 2 NSAID RCTs, 1 dexamethasone meta-analysis, 3 dexamethasone RCTs, 2 ketamine meta-analyses, 5 ketamine RCTs, 2 gabapentin RCTs, 1 clonidine meta-analysis, 3 magnesium RCTs, 2 dexmedetomidine meta-analyses, and 1 dextromethorphan RCT. No meta-analyses or RCTs were found assessing the perioperative efficacy of intravenous lidocaine, amantadine, pregabalin, esmolol, or caffeine in pediatric surgical patients. The available evidence is limited, but suggests that perioperative acetaminophen, NSAIDs, dexamethasone, ketamine, clonidine, and dexmedetomidine may decrease postoperative pain and opioid consumption in some pediatric surgical populations. Not enough, or no, data exist from which to draw conclusions on the perioperative use of gabapentin, magnesium, dextromethorphan, lidocaine, amantadine, pregabalin, esmolol, and caffeine in pediatric surgical patients. Further pharmacokinetic and pharmacodynamics studies to establish both the clinical benefit and efficacy of nonopioid analgesia in pediatric populations are needed.

A primer on systematic reviews in toxicology.

Systematic reviews, pioneered in the clinical field, provide a transparent, methodologically rigorous and reproducible means of summarizing the available evidence on a precisely framed research question. Having matured to a well-established approach in many research fields, systematic reviews are receiving increasing attention as a potential tool for answering toxicological questions. In the larger framework of evidence-based toxicology, the advantages and obstacles of, as well as the approaches for, adapting and adopting systematic reviews to toxicology are still being explored. To provide the toxicology community with a starting point for conducting or understanding systematic reviews, we herein summarized available guidance documents from various fields of application. We have elaborated on the systematic review process by breaking it down into ten steps, starting with planning the project, framing the question, and writing and publishing the protocol, and concluding with interpretation and reporting. In addition, we have identified the specific methodological challenges of toxicological questions and have summarized how these can be addressed. Ultimately, this primer is intended to stimulate scientific discussions of the identified issues to fuel the development of toxicology-specific methodology and to encourage the application of systematic review methodology to toxicological issues.

Lithium Ion Mobility in Lithium Phosphidosilicates: Crystal Structure, 7 Li, 29 Si, and 31 P†MAS NMR Spectroscopy, and Impedance Spectroscopy of Li8 SiP4 and Li2 SiP2.

The need to improve electrodes and Li-ion conducting materials for rechargeable all-solid-state batteries has drawn enhanced attention to the investigation of lithium-rich compounds. The study of the ternary system Li-Si-P revealed a series of new compounds, two of which, Li8 SiP4 and Li2 SiP2 , are presented. Both phases represent members of a new family of Li ion conductors that display Li ion conductivity in the range from 1.15(7)×10-6 Scm-1 at 0 °C to 1.2(2)×10-4 Scm-1 at 75 °C (Li8 SiP4 ) and from 6.1(7)×10-8 Scm-1 at 0 °C to 6(1)×10-6 Scm-1 at 75 °C (Li2 SiP2 ), as determined by impedance measurements. Temperature-dependent solid-state 7 Li NMR spectroscopy revealed low activation energies of about 36 kJ mol-1 for Li8 SiP4 and about 47 kJ mol-1 for Li2 SiP2 . Both compounds were structurally characterized by X-ray diffraction analysis (single crystal and powder methods) and by 7 Li, 29 Si, and 31 P MAS NMR spectroscopy. Both phases consist of tetrahedral SiP4 anions and Li counterions. Li8 SiP4 contains isolated SiP4 units surrounded by Li atoms, while Li2 SiP2 comprises a three-dimensional network based on corner-sharing SiP4 tetrahedra, with the Li ions located in cavities and channels.

Use of a multi-instrument access device in abdominoperineal resections.

BACKGROUND: Laparoscopic colorectal surgery results in less post-operative pain, faster recovery, shorter length of stay and reduced morbidity compared with open procedures. Less or minimally invasive techniques have been developed to further minimise surgical trauma and to decrease the size and number of incisions. This study describes the safety and feasibility of using an umbilical multi-instrument access (MIA) port (Olympus TriPort+) device with the placement of just one 12-mm suprapubic trocar in laparoscopic (double-port) abdominoperineal resections (APRs) in rectal cancer patients. PATIENTS AND METHODS: The study included 20 patients undergoing double-port APRs for rectal cancer between June 2011 and August 2013. Preoperative data were gathered in a prospective database, and post-operative data were collected retrospectively. RESULTS: The 20 patients (30% female) had a median age of 67 years (range 46-80 years), and their median body mass index (BMI) was 26 kg/m2 (range 20-31 kg/m2). An additional third trocar was placed in 2 patients. No laparoscopic procedures were converted to an open procedure. Median operating time was 195 min (range 115-306 min). A radical resection (R0 resection) was achieved in all patients, with a median of 14 lymph nodes harvested. Median length of stay was 8 days (range 5-43 days). CONCLUSION: Laparoscopic APR using a MIA trocar is a feasible and safe procedure. A MIA port might be of benefit as an extra option in the toolbox of the laparoscopic surgeon to further minimise surgical trauma.

Singlet Oxygen Formation during the Charging Process of an Aprotic Lithium-Oxygen Battery.

Aprotic lithium-oxygen (Li-O2 ) batteries have attracted considerable attention in recent years owing to their outstanding theoretical energy density. A major challenge is their poor reversibility caused by degradation reactions, which mainly occur during battery charge and are still poorly understood. Herein, we show that singlet oxygen ((1) Δg ) is formed upon Li2 O2 oxidation at potentials above 3.5 V. Singlet oxygen was detected through a reaction with a spin trap to form a stable radical that was observed by time- and voltage-resolved in operando EPR spectroscopy in a purpose-built spectroelectrochemical cell. According to our estimate, a lower limit of approximately 0.5 % of the evolved oxygen is singlet oxygen. The occurrence of highly reactive singlet oxygen might be the long-overlooked missing link in the understanding of the electrolyte degradation and carbon corrosion reactions that occur during the charging of Li-O2 cells.