Homeotropic orientation of an ion-channel forming mesophase induced by nanotemplate wetting

Anodic aluminum oxide (AAO) membranes were used as templates to control orientation of an ion-channel forming columnar mesophase obtained by self assembly of a wedge-shaped sulfonate molecule. Inside the AAO structure, the director vector of the mesophase is oriented parallel to the pore axis due to the confinement effect. The molecular arrangement induced by the spatial confinement within the pores is extended over several microns into the remnant film on the AAO surface. The homeotropic alignment of the channels promotes unidimensional ion conduction through the film plane, which is manifested by a considerable increase in conductivity relative to isotropic samples.

Interventions for Pancreatitis-New Approaches, Knowledge Gaps, and Research Opportunities: Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop

ABSTRACT

There exists no cure for acute, recurrent acute or chronic pancreatitis and treatments to date have been focused on managing symptoms. A recent workshop held by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) focused on interventions that might disrupt or perhaps even reverse the natural course of this heterogenous disease, aiming to identify knowledge gaps and research opportunities that might inform future funding initiatives for NIDDK. The breadth and variety of identified active or planned clinical trials traverses the spectrum of the disease and was conceptually grouped for the workshop into behavioral, nutritional, pharmacologic and biologic, and mechanical interventions. Cognitive and other behavioral therapies are proven interventions for pain and addiction, but barriers exist to their use. Whilst a disease specific instrument quantifying pain is now validated, an equivalent is lacking for nutrition - and both face challenges in ease and frequency of administration. Multiple pharmacologic agents hold promise. Ongoing development of Patient Reported Outcome (PRO) measurements can satisfy Investigative New Drug (IND) regulatory assessments. Despite multiple randomized clinical trials demonstrating benefit, great uncertainty remains regarding patient selection, timing of intervention, and type of mechanical intervention (endoscopic versus surgery). Challenges and opportunities to establish beneficial interventions for patients were identified.

Controlling Pt nanoparticle sintering by sub-monolayer MgO ALD thin films

Metal nanoparticle (NP) sintering is a major cause of catalyst deactivation, as NP growth reduces the surface area available for reaction. A promising route to halt sintering is to deposit a protective overcoat on the catalyst surface, followed by annealing to generate overlayer porosity for gas transport to the NPs. Yet, such a combined deposition-annealing approach lacks structural control over the cracked protection layer and the number of NP surface atoms available for reaction. Herein, we exploit the tailoring capabilities of atomic layer deposition (ALD) to deposit MgO overcoats on archetypal Pt NP catalysts with thicknesses ranging from sub-monolayers to nm-range thin films. Two different ALD processes are studied for the growth of MgO overcoats on Pt NPs anchored on a SiO2 support, using Mg(EtCp)2 and H2O, and Mg(TMHD)2 and O3, respectively. Spectroscopic ellipsometry and X-ray photoelectron spectroscopy measurements reveal significant growth on both SiO2 and Pt for the former process, while the latter exhibits a drastically lower growth per cycle with an initial chemical selectivity towards Pt. These differences in MgO growth characteristics have implications for the availability of uncoated Pt surface atoms at different stages of the ALD process, as probed by low energy ion scattering, and for the sintering behavior during O2 annealing, as monitored in situ with grazing incidence small angle X-ray scattering (in situ GISAXS). The Mg(TMHD)2-O3 ALD process enables exquisite coverage control allowing a balance between physically blocking the Pt surface to prevent sintering and keeping Pt surface atoms free for reaction. This approach avoids the need for post-annealing, hence also safeguarding the structural integrity of the as-deposited overcoat.

A combined analysis of two prospective randomised studies exploring the impact of extended post-radiation temozolomide on survival outcomes in newly diagnosed glioblastoma

PURPOSE

The optimal duration of post-radiation temozolomide in newly diagnosed glioblastoma remains unclear, with no published phase III randomised trials. Standard-of-care stipulates 6 months. However, in routine care, it is often extended to 12 months, despite lacking robust supporting data.

METHODS

GEINO14-01 (Spain) and EX-TEM (Australia) studies enrolled glioblastoma patients without progression at the end of 6 months post-radiation temozolomide. Participants were randomised 1:1 to six additional months of temozolomide or observation. Primary endpoint was 6-month progression free survival from date of randomisation (6mPFS). Secondary endpoints included overall survival (OS) and toxicity. 204 patients were required to detect an improvement in 6mPFS from 50 to 60% (80% power). Neither study recruited sufficient patients. We performed a combined analysis of individual patient data.

RESULTS

205 patients were recruited: 159 in GEINO14-01 (2014-2018) and 46 in EX-TEM (2019-2022). Median follow-up was 20.0 and 14.5 months. Baseline characteristics were balanced. There was no significant improvement in 6mPFS (57.2% vs 64.0%, OR0.75, p = 0.4), nor across any subgroups, including MGMT methylated; PFS (HR0.92, p = 0.59, median 7.8 vs 9.7 months); or OS (HR1.03, p = 0.87, median 20.1 vs 19.4 months). During treatment extension, 64% experienced any grade adverse event, mainly fatigue and gastrointestinal (both 54%). Only a minority required treatment changes: 4.5% dose delay, 7.5% dose reduction, 1.5% temozolomide discontinuation.

CONCLUSION

For glioblastoma patients, extending post-radiation temozolomide from 6 to 12 months is well tolerated but does not improve 6mPFS. We could not identify any subset that benefitted from extended treatment. Six months should remain standard-of-care.

The persistent inflammation, immunosuppression, and catabolism syndrome 10 years later

With the implementation of new intensive care unit (ICU) therapies in the 1970s, multiple organ failure (MOF) emerged as a fulminant inflammatory phenotype leading to early ICU death. Over the ensuing decades, with fundamental advances in care, this syndrome has evolved into a lingering phenotype of chronic critical illness (CCI) leading to indolent late post-hospital discharge death. In 2012, the University of Florida (UF) Sepsis Critical Illness Research Center (SCIRC) coined the term Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) to provide a mechanistic framework to study CCI in surgical patients. This was followed by a decade of research into PICS-CCI in surgical ICU patients in order to define the epidemiology, dysregulated immunity, and long-term outcomes after sepsis. Other focused studies were performed in trauma ICU patients and emergency department sepsis patients. Early deaths were surprisingly low (4%); 63% experienced rapid recovery. Unfortunately, 33% progressed to CCI, of which 79% had a poor post-discharge disposition and 41% were dead within one year. These patients had biomarker evidence of PICS, and these biomarkers enhanced clinical prediction models for dismal one-year outcomes. Emergency myelopoiesis appears to play a central role in the observed persistent immune dysregulation that characterizes PICS-CCI. Older patients were especially vulnerable. Disturbingly, over half of the older CCI patients were dead within one year and older CCI survivors remained severely disabled. Although CCI is less frequent (20%) after major trauma, PICS appears to be a valid concept. This review will specifically detail the epidemiology of CCI, PICS biomarkers, effect of site of infection, acute kidney injury, effect on older patients, dysfunctional high-density lipoproteins, sarcopenia/cachexia, emergency myelopoiesis, dysregulated erythropoiesis, and potential therapeutic interventions.

A review of UF SCIRC’s research efforts characterizing CCI, PICS biomarkers, effect of site of infection, acute kidney injury, effects on older patients, dysfunctional high-density lipoproteins, sarcopenia/cachexia, emergency myelopoiesis, and dysregulated erythropoiesis.

Synthesis and Structural Insight into poly(dimethylsiloxane)-b-poly(2-vinylpyridine) Copolymers

In this study, the use of anionic polymerization for the synthesis of living poly(dimethylsiloxane) or PDMS-Li+, as well as poly(2-vinylpyridine) or P2VP-Li+ homopolymers, and the subsequent use of chlorosilane chemistry in order for the two blocks to be covalently joined leading to PDMS-b-P2VP copolymers is proposed. High vacuum manipulations enabled the synthesis of well-defined materials with different molecular weights (Μ¯n, from 9.8 to 36.0 kg/mol) and volume fraction ratios (φ, from 0.15 to 0.67). The Μ¯n values, dispersity indices, and composition were determined through membrane/vapor pressure osmometry (MO/VPO), size exclusion chromatography (SEC), and proton nuclear magnetic resonance spectroscopy (1H NMR), respectively, while the thermal transitions were determined via differential scanning calorimetry (DSC). The morphological characterization results suggested that for common composition ratios, lamellar, cylindrical, and spherical phases with domain periodicities ranging from approximately 15 to 39 nm are formed. A post-polymerization chemical modification reaction to quaternize the nitrogen atom in some of the P2VP monomeric units in the copolymer with the highest P2VP content, and the additional characterizations through 1H NMR, infrared spectroscopy, DSC, and contact angle are reported. The synthesis, characterization, and quaternization of the copolymer structure are important findings toward the preparation of functional materials with enhanced properties suitable for various nanotechnology applications.

Porous Ionic Liquids Go Green

This Perspective points toward pathways to prepare porous ionic liquids using easily accessible materials, aiming for reduced environmental impact. We demonstrate that suspensions of porous solids are stable in eutectic mixtures, underscoring their potential for the preparation of porous ionic liquids. Porous ionic liquids retain the wide electrochemical window observed in their precursor pure ionic liquids, rendering them well-suited for green electrochemical reactions, particularly those involving gases whose solubility is enhanced in the porous suspensions. Moreover, their capacity as gas-rich media points to sustainable biomedical and pharmaceutical applications, provided nontoxic, biocompatible ionic liquids and porous solids are utilized.

Defying decomposition: the curious case of choline chloride

Chemists aim to meet modern sustainability, health, and safety requirements by replacing conventional solvents with deep eutectic solvents (DESs). Through large melting point depressions, DESs may incorporate renewable solids in task-specific liquids. Yet, DES design is complicated by complex molecular interactions and a lack of comprehensive property databases. Even measuring pure component melting properties can be challenging, due to decomposition before melting. Here we overcame the decomposition of the quintessential DES constituent, choline chloride (ChCl). We measured its enthalpy of fusion (13.8 ± 3.0 kJ ⋅ mol) and melting point (687 ± 9 K) by fast scanning calorimetry combined with micro-XRD and high-speed optical microscopy. Our thermodynamically coherent fusion properties identify ChCl as an ionic plastic crystal and demonstrate negative deviations from ideal mixing for ChCl-contradicting previous assumptions. We hypothesise that the plastic crystal nature of ammonium salts governs their resilience to melting; pure or mixed. We show that DESs based on ionic plastic crystals can profit from (1) a low enthalpy of fusion and (2) favourable mixing. Both depress the melting point and can be altered through ion selection. Ionic plastic crystal-based DESs thus offer a platform for task-specific liquids at a broad range of temperatures and compositions.

Self-Assembled Nanostructures in Aprotic Ionic Liquids Facilitate Charge Transport at Elevated Pressure

Ionic liquids (ILs), revealing a tendency to form self-assembled nanostructures, have emerged as promising materials in various applications, especially in energy storage and conversion. Despite multiple reports discussing the effect of structural factors and external thermodynamic variables on ion organization in a liquid state, little is known about the charge-transport mechanism through the self-assembled nanostructures and how it changes at elevated pressure. To address these issues, we chose three amphiphilic ionic liquids containing the same tetra(alkyl)phosphonium cation and anions differing in size and shape, i.e., thiocyanate [SCN]-, dicyanamide [DCA]-, and tricyanomethanide [TCM]-. From ambient pressure dielectric and mechanical experiments, we found that charge transport of all three examined ILs is viscosity-controlled at high temperatures. On the other hand, ion diffusion is much faster than structural dynamics in a nanostructured supercooled liquid (at T < 210 ± 3 K), which constitutes the first example of conductivity independent from viscosity in neat aprotic ILs. High-pressure measurements and MD simulations reveal that the created nanostructures depend on the anion size and can be modified by compression. For small anions, increasing pressure shapes immobile alkyl chains into lamellar-type phases, leading to increased anisotropic diffusivity of anions through channels. Bulky anions drive the formation of interconnected phases with continuous 3D curvature, which render ion transport independent of pressure. This work offers insight into the design of high-density electrolytes with percolating conductive phases providing efficient ion flow.

Early VTE Prophylaxis in Severe Traumatic Brain Injury: A Propensity Score Weighted EAST Multi-Center Study

BACKGROUND

Patients with TBI are at high risk of venous thromboembolism events (VTE). We hypothesized that early chemical VTE prophylaxis initiation (≤24 hours of a stable head CT) in severe TBI would reduce VTE without increasing risk of intracranial hemorrhage expansion (ICHE).

METHODS

A retrospective review of adult patients ≥18 years of age with isolated severe TBI (AIS ≥ 3) who were admitted to 24 level 1 and level 2 trauma centers from January 1, 2014 to December 31 2020 was conducted. Patients were divided into those who did not receive any VTE prophylaxis (NO VTEP), who received VTE prophylaxis ≤24 hours after stable head CT (VTEP ≤24) and who received VTE prophylaxis >24 hours after stable head CT (VTEP>24). Primary outcomes were VTE and ICHE. Covariate balancing propensity score weighting was utilized to balance demographic & clinical characteristics across three groups. Weighted univariate logistic regression models were estimated for VTE & ICHE with patient group as predictor of interest.

RESULTS

Of 3,936 patients, 1,784 met inclusion criteria. Incidences of VTE was significantly higher in the VTEP>24 group, with higher incidences of DVT in the group. Higher incidences of ICHE were observed in the VTEP≤24 and VTEP>24 groups. After propensity score weighting, there was a higher risk of VTE in patients in VTEP >24 compared to those in VTEP≤24 ( [OR] = 1.51; [95%CI] = 0.69-3.30; p = 0.307), however was not significant. Although, the No VTEP group had decreased odds of having ICHE compared to VTEP≤24 (OR = 0.75; 95%CI = 0.55-1.02, p = 0.070), the result was not statistically significant.

CONCLUSIONS

In this large multi-center analysis, there were no significant differences in VTE based on timing of initiation of VTE prophylaxis. Patients who never received VTE prophylaxis had decreased odds of ICHE. Further evaluation of VTE prophylaxis in larger randomized studies will be necessary for definitive conclusions.

LEVEL OF EVIDENCE

level III, Therapeutic Care Management.

Microstructuring to Improve the Thermal Stability of GeSn Layers

Tin segregation in Ge_1-xSn_x alloys is one of the major problems potentially hindering the use of this material in devices. Ge_1-xSn_x microdisks fabricated from layers with Sn concentrations up to 16.9% underwent here annealing at temperatures as high as 400 °C for 20 min without Sn segregation, in contrast with the full segregation observed in the corresponding blanket layers annealed simultaneously. After annealing, no changes in the elemental composition of the microdisks were evidenced. An enhancement of the total integrated photoluminescence, with no modifications of the emission energy, was also observed. These findings show that microstructuring offers a completely new path in maintaining the stability of high Sn concentration Ge_1-xSn_x layers at temperatures much higher than those used for growth. This approach enables the use of thermal annealing processes to improve the properties of this alloy in optoelectronic devices (such as light emitting diodes, lasers, photodetectors, or modulators). It should also facilitate the integration of Ge_1-xSn_x into well-established technologies requiring medium temperature processes. The same strategy may help to prevent Sn segregation during high temperature processes in similar metastable alloys.

Cuticle - Designed by Nature for the Sake of the Hair

OBJECTIVE

The cuticle of human hair has been examined, via a range of analytical methods, in order to reveal previously unknown information about its structure and to deepen understanding of its contribution to fibre properties.

METHODS

Cross sections of hair fibre have been examined with X-ray microdiffraction oriented perpendicular to the surface of the cross-sections. AFM investigations were carried out for further investigating and deciphering the structure of the cuticle. Moisture sorption analytics of cuticle separated from fibre, and mechanical tests of decuticled fibres against virgin fibres, were used for understanding the role of the cuticle in the economy of hair fibre.

RESULTS

Previously unknown swelling behaviour of the hair cuticle during moisture sorption has been revealed, as has an increased significance of the cuticle's role in moisture management at higher values of relative humidity. Through AFM investigation, the reaction of hair cuticles with chlorine water has further strengthened the idea that the Allwörden membrane does not exist, and is actually an artefact of the delamination of the A-layer and exocuticle from the underlying endocuticle. Using decuticled fibres for stress-strain tests, and by comparing the results with those of virgin fibres, the effect of the cuticle on the post-yield area of the hair fibre stress-strain diagram has also been demonstrated. Finally, X-ray microdiffraction and AFM investigations suggest that the cuticle possesses a small-scale ordered structure, based on possibly not fully crystalline and irregularly arranged α-helices oriented almost perpendicular to the growth axis of the fibre and enhancing the general description of cuticle as the protective layer of the fibre.

CONCLUSION

The role of the cuticle for the hair fibre is more complex than previously thought. The cuticle is demonstrated not only to possess a hidden rod-matrix structure, that supports its protective nature, but also to play specific roles in the fibre's response to moisture, and in fibre mechanical behaviour.

Amorphous-to-crystal transition in the layer-by-layer growth of bivalve shell prisms

Biomineralization integrates complex physical and chemical processes bio-controlled by the living organisms through ionic concentration regulation and organic molecules production. It allows tuning the structural, optical and mechanical properties of hard tissues during ambient-condition crystallisation, motivating a deeper understanding of the underlying processes. By combining state-of-the-art optical and X-ray microscopy methods, we investigated early-mineralized calcareous units from two bivalve species, Pinctada margaritifera and Pinna nobilis, revealing chemical and crystallographic structural insights. In these calcite units, we observed ring-like structural features correlated with a lack of calcite and an increase of amorphous calcium carbonate and proteins contents. The rings also correspond to a larger crystalline disorder and a larger strain level. Based on these observations, we propose a temporal biomineralization cycle, initiated by the production of an amorphous precursor layer, which further crystallizes with a transition front progressing radially from the unit centre, while the organics are expelled towards the prism edge. Simultaneously, along the shell thickness, the growth occurs following a layer-by-layer mode. These findings open biomimetic perspectives for the design of refined crystalline materials. STATEMENT OF SIGNIFICANCE: Calcareous biominerals are amongst the most present forms of biominerals. They exhibit astonishing structural, optical and mechanical properties while being formed at ambient synthesis conditions from ubiquitous ions, motivating the deep understanding of biomineralization. Here, we unveil the first formation steps involved in the biomineralization cycle of prismatic units of two bivalve species by applying a new multi-modal non-destructive characterization approach, sensitive to chemical and crystalline properties. The observations of structural features in mineralized units of different ages allowed the derivation of a temporal sequence for prism biomineralization, involving an amorphous precursor, a radial crystallisation front and a layer-by-layer sequence. Beyond these chemical and physical findings, the herein introduced multi-modal approach is highly relevant to other biominerals and bio-inspired studies.

Treatment and outcomes of anticoagulated geriatric trauma patients with traumatic intracranial hemorrhage after falls

Introduction

Emergency physicians and trauma surgeons are increasingly confronted with pre-injury direct oral anticoagulants (DOACs). The objective of this study was to assess if pre-injury DOACs, compared to vitamin K antagonists (VKA), or no oral anticoagulants is independently associated with differences in treatment, mortality and inpatient rehabilitation requirement.

Methods

We performed a review of the prospectively maintained institutional trauma registry at an urban academic level 1 trauma center. We included all geriatric patients (aged ≥ 65 years) with tICH after a fall, admitted between January 2011 and December 2018. Multivariable logistic regression analysis controlling for demographics, comorbidities, vital signs, and tICH types were performed to identify the association between pre-injury anticoagulants and reversal agent use, neurosurgical interventions, inhospital mortality, 3-day mortality, and discharge to inpatient rehabilitation.

Results

A total of 1453 tICH patients were included (52 DOAC, 376 VKA, 1025 control). DOAC use was independently associated with lower odds of receiving specific reversal agents [odds ratio (OR) 0.28, 95% confidence interval (CI) 0.15–0.54] than VKA patients. DOAC use was independently associated with requiring neurosurgical intervention (OR 3.14, 95% CI 1.36–7.28). VKA use, but not DOAC use, was independently associated with inhospital mortality, or discharge to hospice care (OR 1.62, 95% CI 1.15–2.27) compared to controls. VKA use was independently associated with higher odds of discharge to inpatient rehabilitation (OR 1.41, 95% CI 1.06–1.87) compared to controls.

Conclusion

Despite the higher neurosurgical intervention rates, patients with pre-injury DOAC use were associated with comparable rates of mortality and discharge to inpatient rehabilitation as patients without anticoagulation exposure. Future research should focus on risk assessment and stratification of DOAC-exposed trauma patients.

Assessing Fast Structure Formation Processes in Isotactic Polypropylene with a Combination of Nanofocus X-ray Diffraction and In Situ Nanocalorimetry

A combination of in situ nanocalorimetry with simultaneous nanofocus 2D Wide-Angle X-ray Scattering (WAXS) was used to study polymorphic behaviour and structure formation in a single micro-drop of isotactic polypropylene (iPP) with defined thermal history. We were able to generate, detect, and characterize a number of different iPP morphologies using our custom-built ultrafast chip-based nanocalorimetry instrument designed for use with the European Synchrotron Radiation Facility (ESRF) high intensity nanofocus X-ray beamline facility. The detected iPP morphologies included monoclinic alpha-phase crystals, mesophase, and mixed morphologies with different mesophase/crystalline compositional ratios. Monoclinic crystals formed from the mesophase became unstable at heating rates above 40 K s-1 and showed melting temperatures as low as ~30 K below those measured for iPP crystals formed by slow cooling. We also studied the real-time melt crystallization of nanogram-sized iPP samples. Our analysis revealed a mesophase nucleation time of around 1 s and the co-existence of mesophase and growing disordered crystals at high supercooling ≤328 K. The further increase of the iPP crystallization temperature to 338 K changed nucleation from homogeneous to heterogeneous. No mesophase was detected above 348 K. Low supercooling (≥378 K) led to the continuous growth of the alpha-phase crystals. In conclusion, we have, for the first time, measured the mesophase nucleation time of supercooled iPP melted under isothermal crystallization conditions using a dedicated experimental setup designed to allow simultaneous ultrafast chip-based nanocalorimetry and nanofocus X-ray diffraction analyses. We also provided experimental evidence that upon heating, the mesophase converts directly into thermodynamically stable monoclinic alpha-phase crystals via perfection and reorganization and not via partial melting. The complex phase behaviour of iPP and its dependence on both crystallization temperature and time is presented here using a time-temperature-transformation (TTT) diagram.

Implementation Science and Nutrition: From Research to Practice

Implementation science (IS) is a young field that seeks to minimize the gap between what we know and what we practice, otherwise known as the "know-do gap." Recently, IS has focused on research that expedites the dissemination of evidence-based knowledge, accelerates the translation of interventions to improve knowledge gaps, shrinks healthcare disparities, enhances care of complex medical conditions, and narrows variation in clinical practice and policy. This article seeks to review theoretical frameworks of IS and demonstrate how IS can be utilized to improve nutrition care. Specific examples in this article include implementation of initiatives to improve documentation of malnutrition, increase provision of oral nutrition supplements, increase use of Enhanced Recovery After Surgery protocols, and increase energy and protein delivery. Clinical nutrition is a growing field with more and more research findings pointing to new therapies. In implementing these new therapies, practitioners should recognize the complex system present in healthcare and lean on IS findings to speed implementation and more rapidly improve clinical outcomes.

Summary of Proceedings and Expert Consensus Statements From the International Summit "Lipids in Parenteral Nutrition"

BACKGROUND

The 2018 Lipids in Parenteral Nutrition summit involved a panel of experts in clinical nutrition, lipid metabolism, and pharmacology, to assess the current state of knowledge and develop expert consensus statements regarding the use of intravenous lipid emulsions in various patient populations and clinical settings. The main purpose of the consensus statements is to assist healthcare professionals by providing practical guidance on common clinical questions related to the provision of lipid emulsions as part of parenteral nutrition (PN).

METHODS

The summit was designed to allow interactive discussion and consensus development. The resulting consensus statements represent the collective opinion of the members of the expert panel, which was informed and supported by scientific evidence and clinical experience.

RESULTS

The current article summarizes the key discussion topics from the summit and provides a set of consensus statements designed to complement existing evidence-based guidelines. Lipid emulsions are a major component of PN, serving as a condensed source of energy and essential fatty acids. In addition, lipids modulate a variety of biologic functions, including inflammatory and immune responses, coagulation, and cell signaling. A growing body of evidence suggests that lipid emulsions containing ω-3 fatty acids from fish oil confer important clinical benefits via suppression of inflammatory mediators and activation of pathways involved in the resolution of inflammation.

CONCLUSIONS

This article provides a set of expert consensus statements to complement formal PN guideline recommendations.

Necrotizing Soft Tissue Infection: Time is Crucial, and the Admitting Service Matters

Background: Early diagnosis and prompt debridement of necrotizing soft tissue infection (NSTI) improves the outcome. We sought to determine whether failure to admit NSTI patients to acute care surgery (ACS) departments delays treatment and increases the mortality rate. Methods: Patients with NSTI were identified using the 2007-2018 institutional emergency surgery database at a tertiary care hospital. The diagnosis was confirmed by the operative/pathology reports. Patients who developed NSTI during hospitalization or underwent initial debridement at an outside hospital were excluded. Patients admitted to a non-ACS service (e.g., medicine, gynecology) were compared with those admitted to the ACS service with respect to co-morbidities, clinical presentation, time to surgery, and mortality rate. Multi-variable linear and logistic analyses were performed to determine whether admission to a non-ACS service predicts a delay in surgery or an increase in the mortality rate. Results: Of 132 patients, 91 met the inclusion criteria. The mean age was 53 years; 56% were male. Twenty patients (22%) were admitted to a non-ACS service, two thirds of them with an initial misdiagnosis (e.g., cellulitis). The demographics, co-morbidities, and clinical presentation were similar in the two groups except that the non-ACS group more often had human immunodeficiency virus infection (15.0% versus 2.8%; p = 0.04) and less often presented with erythema (70% versus 94.4%; p = 0.01). The median time to incision in non-ACS patients was significantly longer (24.8 versus 3.9 hours; p < 0.001). The mortality rates were 20.0% for the non-ACS group and 7.0% for the ACS group (p = 0.086). Multi-variable analyses revealed that absence of erythema is independently associated with a non-ACS admission (odds ratio [OR] 5.9; 95% confidence interval [CI] 1.3-25.6; p = 0.02), and non-ACS admissions correlated independently with delayed surgery (OR 35.20; 95% CI 3.86-321.20; p = 0.002). Conclusions: Admission of patients with NSTI to a non-ACS service often occurs because of initial misdiagnosis, especially in the absence of skin erythema; correlates with significantly delayed surgery; and might lead to more deaths.

Lipid intensive drug therapy for sepsis pilot: A Bayesian phase I clinical trial

OBJECTIVES

Cholesterol may be protective in sepsis. Patients with early sepsis may have critically low cholesterol levels that are associated with poor outcomes. The study objective was to test the safety of a fish oil-containing lipid injectable emulsion for stabilizing early cholesterol levels in sepsis.

METHODS

Phase I Bayesian optimal interval design trial of adult patients with septic shock (Sequential Organ Failure Assessment score ≥4 or vasopressor dependence). Using sequential dose escalation, participants received 2 doses of 1.0 to 1.6 g/kg of lipid emulsion (Smoflipid 20% lipid emulsion) within 48 hours of enrollment. Cholesterol levels, function, and organ failure were assessed serially during the first 7 days of hospital admission.

MEASUREMENTS AND MAIN RESULTS

A total of 10 patients with septic shock were enrolled. One patient withdrew for social reasons. Another patient had an unrelated medical complication and received 1 drug dose. Of 9 patients, mean age was 58 years (SD 16), median Sequential Organ Failure Assessment was 8, and 28-day mortality was 30%. No serious adverse events related to lipid infusion occurred. The six occurrences of non-serious adverse events possibly related to lipid infusion included hyperglycemia (1), elevated triglycerides (3), anemia (1), and vascular access redness/pain (1) for all doses. The mean change in total cholesterol levels from enrollment was -7 (SD 16.6) at 48 hours and 14 (SD 25.2) at 7 days.

CONCLUSIONS

Fish oil-containing lipid emulsion administration during early septic shock was safe. Further studies are needed to assess effects on cholesterol levels, function, and organ failure.

CLINICAL TRIAL REGISTRATION

NCT03405870.

Clinical Nutrition Research and the COVID-19 Pandemic: A Scoping Review of the ASPEN COVID-19 Task Force on Nutrition Research

The purpose of this scoping review by the American Society for Parenteral and Enteral Nutrition (ASPEN) Coronavirus Disease 2019 (COVID-19) Nutrition Task Force was to examine nutrition research applicable to the COVID-19 pandemic. The rapid pace of emerging scientific information has prompted this activity to discover research/knowledge gaps. This methodology adhered with recommendations from the Joanna Briggs Institute. There were 2301 citations imported. Of these, there were 439 articles fully abstracted, with 23 main topic areas identified across 24 article types and sourced across 61 countries and 51 specialties in 8 settings and among 14 populations. Epidemiological/mechanistic relationships between nutrition and COVID-19 were reviewed and results mapped to the Population, Intervention, Comparator, Outcome, and Time (PICO-T) questions. The aggregated data were analyzed by clinical stage: pre-COVID-19, acute COVID-19, and chronic/post-COVID-19. Research gaps were discovered for all PICO-T questions. Nutrition topics meriting urgent research included food insecurity/societal infrastructure and transcultural factors (pre-COVID-19); cardiometabolic-based chronic disease, pediatrics, nutrition support, and hospital infrastructure (acute COVID-19); registered dietitian nutritionist counseling (chronic/post-COVID-19); and malnutrition and management (all stages). The paucity of randomized controlled trials (RCTs) was particularly glaring. Knowledge gaps were discovered for PICO-T questions on pediatrics, micronutrients, bariatric surgery, and transcultural factors (pre-COVID-19); enteral nutrition, protein-energy requirements, and glycemic control with nutrition (acute COVID-19); and home enteral and parenteral nutrition support (chronic/post-COVID-19). In conclusion, multiple critical areas for urgent nutrition research were identified, particularly using RCT design, to improve nutrition care for patients before, during, and after COVID-19.

Mesoscale structures in amorphous silks from a spider's orb-web

Of the 7-8 silk fibers making up an orb-web only the hierarchical structural organization of semicrystalline radial fibers -composed of major ampullate silk- has been studied in detail, given its fascinating mechanical features. While major ampullate silk's nanofibrillar morphology is well established, knowhow on mesoscale (> 50-100 nm) assembly and its contribution to mechanical performance is limited. Much less is known on the hierarchical structural organization of other, generally less crystalline fibers contributing to an orb-webs' function. Here we show by scanning X-ray micro&nanodiffraction that two fully amorphous, fine silk fibers from the center of an orb-web have different mesoscale features. One of the fibers has a fibrillar composite structure resembling stiff egg case silk. The other fiber has a skin-core structure based on a nanofibrillar ribbon wound around a disordered core. A fraction of nanofibrils appears to have assembled into mesoscale fibrils. This fiber becomes readily attached to the coat of major ampullate silk fibers. We observe that a detached fiber has ripped out the glycoprotein skin-layer containing polyglycine II nanocrystallites. The anchoring of the fiber in the coat suggests that it could serve for strengthening the tension and cohesion of major ampullate silk fibers.

Multiple Mechanical Gradients are Responsible for the Strong Adhesion of Spider Attachment Hair

Wandering spiders climb vertically and walk upside-down on rough and smooth surfaces using a nanostructured attachment system on their feet. The spiders are assumed to adhere by intermolecular van der Waals forces between the adhesive structures and the substrate. The adhesive elements are arranged highly ordered on the hierarchically structured attachment hair (setae). While walking, it has been suggested that the spiders apply a shear force on their legs to increase friction. However, the detailed mechanical behavior of the hair's structures during attachment and detachment remains unknown. Here, gradients of the mechanical properties of the attachment hair on different length scales that have evolved to support attachment, stabilize adhesion in contact, and withstand high stress at detachment, examined by in situ experiments, are shown. Shearing helps to self-align the adhesive elements with the substrate. The study is anticipated to contribute to the development of optimized artificial dry adhesives.

The Geriatric Nutritional Risk Index is a powerful predictor of adverse outcome in the elderly emergency surgery patient

BACKGROUND

The degree to which malnutrition impacts perioperative outcomes in the elderly emergency surgery (ES) patient remains unknown. We aimed to study the relationship between malnutrition, as measured by the Geriatric Nutritional Risk Index (GNRI), and postoperative outcomes in elderly patients undergoing ES.

METHODS

Using the 2007 to 2016 American College of Surgeons National Surgical Quality Improvement Program database, all patients 65 years or older undergoing ES were included in our study. The GNRI, defined as (1.489 × albumin [g/L]) + (41.7 × [weight/ideal weight]) was calculated for each patient in the database. Patients with missing height, weight, or preoperative albumin data were excluded. Patients were divided into four malnutrition groups: very severe (GNRI < 73), severe (GNRI, 73-82), moderate (GNRI, 82-92), and mild (GNRI, 92-98). Geriatric Nutritional Risk Index greater than 98 constituted the normal nutrition group. Risk-adjusted multivariable logistic regressions were performed to study the relationship between malnutrition-measured using either GNRI, albumin level, or body mass index less than 18.5 kg/m-and the following postoperative outcomes: 30-day mortality, 30-day morbidity (including infectious and noninfectious complications), and hospital length of stay. The relationship between GNRI score and 30-day mortality for six common ES procedures was then assessed.

RESULTS

A total of 82,725 patients were included in the final analyses. Of these, 55,214 were malnourished with GNRI less than 98 (66.74%). Risk-adjusted multivariable analyses showed that, as malnutrition worsened from mild to very severe, the risk of mortality, morbidity, and the hospital length of stay progressively increased (all p < 0.05). Patients with very severe malnutrition had at least a twofold increased likelihood of mortality (odds ratio [OR], 2.79; 95% confidence interval [CI], 2.57-3.03), deep vein thrombosis (OR, 2.07; 95% CI, 1.77-2.42), and respiratory failure (OR, 1.95; 95% CI, 1.81-2.11). Geriatric Nutritional Risk Index predicted mortality better than albumin or body mass index alone for ES.

CONCLUSION

Malnutrition, measured using GNRI, is a strong independent predictor of adverse outcomes in the elderly ES patient and could be used to assess the nutrition status and counsel patients (and families) preoperatively.

LEVEL OF EVIDENCE

Prognostic study, Level IV.

No news is good news? Three-year postdischarge mortality of octogenarian and nonagenarian patients following emergency general surgery

BACKGROUND

Outcome data on the very elderly patients undergoing emergency general surgery (EGS) are sparse. We sought to examine short- and long-term mortality in the 80 plus years population following EGS.

METHODS

Using our institutional 2008-2018 EGS Database, all the 80 plus years patients undergoing EGS were identified. The data were linked to the Social Security Death Index to determine cumulative mortality rates up to 3 years after discharge. Univariate and multivariable logistic regression analyses were used to determine predictors of in-hospital and 1-year cumulative mortality.

RESULTS

A total of 385 patients were included with a mean age of 84 years; 54% were female. The two most common comorbidities were hypertension (76.1%) and cardiovascular disease (40.5%). The most common procedures performed were colectomy (20.0%), small bowel resection (18.2%), and exploratory laparotomy for other procedures (15.3%; e.g., internal hernia, perforated peptic ulcer). The overall in-hospital mortality was 18.7%. Cumulative mortality rates at 1, 2, and 3 years after discharge were 34.3%, 40.5%, and 43.4%, respectively. The EGS procedure associated with the highest 1-year mortality was colectomy (49.4%). Although hypertension, renal failure, hypoalbuminemia, hyperbilirubinemia, and elevated liver enzymes predicted in-hospital mortality, the only independent predictors of cumulative 1-year mortality were hypoalbuminemia (odds ratio, 2.17; 95% confidence interval, 1.10-4.27; p = 0.025) and elevated serum glutamic pyruvic transaminase (SGOT) level (odds ratio, 2.56; 95% confidence interval, 1.09-4.70; p = 0.029) at initial presentation. Patients with both factors had a cumulative 1-year mortality rate of 75.0%.

CONCLUSION

More than half of the very elderly patients undergoing major EGS were still alive at 3 years postdischarge. The combination of hypoalbuminemia and elevated liver enzymes predicted the highest 1-year mortality. Such information can prove useful for patient and family counseling preoperatively.

LEVEL OF EVIDENCE

Prognostic, Level III.

Chronic Critically Ill Septic Patients Exhibit Persistent Expression of Pro-Inflammatory Lipidomics

Objectives

In order to evaluate the therapeutic potential of resolvins to reduce inflammation in CCI-PICS, we recapitulated Glue Grant leukotriene and resolvin lipidomic scores above to quantify lipidomics in severe sepsis/septic shock survivors.

Methods

Ongoing University of Florida (UF) Sepsis Critical Illness Research Center (SCIRC) research studies indicate that Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) occurs as a result of a self-perpetuating cycle of low-grade inflammation. However, specialized pro-resolving mediators (SPMs) – metabolically active lipid byproducts of omega-3 fatty acids – can promote inflammatory deceleration and resolution.,1 Post hoc analysis of the Glue Grant Data developed a mathematical lipidomic expression to better understand genes responsible for production and degradation of resolvins and leukotrienes.,2

Leukotriene Score = (ALOX5 * ALX5AP * LTA4H * LTB4R)/(HPGD + PTGR1 + CYP4F3)

Resolvin Score = [(ALOX5 * ALOX15) * (FPR2 + GPR32 + CMKLR1)]/(HPGD + PTGR1)

When the targeted genes were scored using a weighted scheme accounting for enzyme and receptor activity, patients with uncomplicated recoveries had higher resolvin scores (P &lt; 0.001) and lower leukotriene scores (P &lt; 0.001).

Utilizing our PICS patient data, we recapitulated the aforementioned lipidomic scores above to quantify expression in severe sepsis/septic shock survivors.

Results

Leukotriene and resolvin scores are depicted in Figure 1 at specific time points 0 (healthy controls), 3 hours, 1 and 14 days. The leukotriene score remains elevated consistent with ongoing inflammatory genotypic expression. Interestingly, the resolvin score also remains elevated in the CCI (Glue Grant complicated cohort) patient population when compared to our Rapid Recovery (RAP or uncomplicated) patients

*Accompanied by two graphs depicting correlating numerical values for the aforementioned Leukotriene and Resolvin scores.

Conclusions

In our patient population of sepsis survivors, the leukotriene score is similarly elevated to the complicated Glue Grant patients of polytrauma. The resolvin score, however, remains elevated in the CCI-PICS population compared to RAP; this is contrary to expected scores if resolution of inflammation is predicted.

Funding Sources

University of Florida.

Mapping the 3D orientation of nanocrystals and nanostructures in human bone: Indications of novel structural features

Bone is built from collagen fibrils and biomineral nanoparticles. In humans, they are organized in lamellar twisting patterns on the microscale. It has been a central tenet that the biomineral nanoparticles are co-aligned with the bone nanostructure. Here, we reconstruct the three-dimensional orientation in human lamellar bone of both the nanoscale features and the biomineral crystal lattice from small-angle x-ray scattering and wide-angle x-ray scattering, respectively. While most of the investigated regions show well-aligned nanostructure and crystal structure, consistent with current bone models, we report a localized difference in orientation distribution between the nanostructure and the biomineral crystals in specific bands. Our results show a robust and systematic, but localized, variation in the alignment of the two signals, which can be interpreted as either an additional mineral fraction in bone, a preferentially aligned extrafibrillar fraction, or the result of transverse stacking of mineral particles over several fibrils.

0645 The Association of Hypoglossal Nerve Stimulator Adherence and Insomnia

Introduction

The gold standard for treatment of Obstructive sleep apnea (OSA) is continuous positive airway pressure (CPAP). However, CPAP adherence is less than 50%. An alternative treatment is the hypoglossal nerve stimulator (HNS) which displaces the tongue anteriorly to treat upper airway obstruction. Difficulties tolerating HNS are related to stimulation discomfort. In this study, we investigated insomnia as a barrier to adherence.

Methods

Patients implanted and activated with HNS at The Ohio State University Wexner Medical Center between 2015 and 2019 were eligible. Patient usage data from the previous six months was obtained and subjects were asked to complete an Insomnia Severity Index (ISI). Participants were divided into adherent (defined as use ≥28 hours/week) and non-adherent (use &lt;28 hours/week).

Results

32 subjects were enrolled, 22 in the adherent group and 10 in the non-adherent group. There was a significant decrease in mean treatment AHI in both groups: 36.25 to 11.14 in the adherent group and 36.30 to 15.69 in the non-adherent group (p&lt;0.0001). The mean ISI score in the adherent group was 6.84 which is consistent with no clinically significant insomnia and 8.67 in the non-adherent group consistent with subthreshold insomnia. However, there was not a statistically significant difference between the two groups (p=0.441). There was a statistically significant higher score for the question “Do you worry about your sleep problems?” in the non-adherent group (1.78, SD1.39 vs 0.74. SD 0.81) (p =0.018).

Conclusion

This study suggests that patients who have difficulty with sleep may have more difficulty with HNS adherence than those who do not. In particular the question stating “Do you worry about your sleep problems” had a statistically higher score in the non-adherent group. Prospective studies are needed to further explore a possible relationship between insomnia and HNS adherence.

Support

N/A

Clinical outcomes in men of diverse ethnic backgrounds with metastatic castration-resistant prostate cancer

BACKGROUND

We have shown previously in multivariable analysis that black men had 19% lower risk of death than white men with metastatic castration-resistant prostate cancer (mCRPC) treated with a docetaxel and prednisone (DP)-based regimen. The primary goal of this analysis was to compare progression-free survival (PFS), biochemical PFS, ≥50% decline in prostate-specific antigen (PSA) from baseline and objective response rate (ORR) in white, black and Asian men with mCRPC treated with a DP-based regimen.

PATIENTS AND METHODS

Individual patient data from 8820 mCRPC men randomized on nine phase III trials to a DP-containing regimen were combined. Race used in the analysis was based on self-report. End points were PFS, biochemical PSA, ≥50% decline in PSA from baseline and ORR. The proportional hazards and the logistic regression models were employed to assess the prognostic importance of race in predicting outcomes adjusting for established prognostic factors.

RESULTS

Of 8820 patients, 7528 (85%) were white, 500 (6%) were black, 424 were Asian (5%) and 368 (4%) had race unspecified. Median PFS were 8.3 [95% confidence interval (CI) 8.2-8.5], 8.2 (95% CI 7.4-8.8) and 8.3 (95% CI 7.6-8.8) months in white, black and Asian men, respectively. Median PSA PFS were 9.9 (95% CI 9.7-10.4), 8.5 (95% CI 8.0-10.3) and 11.1 (95% CI 9.9-12.5) months in white, black and Asian men, respectively.

CONCLUSIONS

We observed no differences in clinical outcomes by race and ethnic groups in men with mCRPC enrolled on these phase III clinical trials with DP.

Mild traumatic brain injuries with minor intracranial hemorrhage: Can they Be safely managed in the community? - A cohort study

BACKGROUND

Patients with mild traumatic brain injury (mTBI) are frequently transferred to level 1 trauma centers (L1TC) if they have minor findings on a computerized tomographic scan of the head due to the absence of continuous neurosurgical coverage in community hospitals (CH). We hypothesized that such patients can be safely managed at community hospitals with a qualified Trauma team.

METHODS

This is a multicentered Retrospective Cohort Study. Patients with mild Traumatic Brain Injury (defined as Glasgow Coma Scale [GCS] 13-15 at presentation) and with minor findings on head Computerized Tomography (CT) presenting at a L1TC or 4 Community Hospitals between March 1st, 2012 and February 28th, 2014 were included. All these community hospitals are Level III Trauma center with a well-organized trauma team. Minor CT findings were defined as 1) epidural hematoma<2 mm; 2) subarachnoid hemorrhage<2 mm; 3) subdural hematoma<4 mm; 4) intraparenchymal hemorrhage<5 mm; 5) minor pneumocephalus; or 6) linear or minimally depressed skull fracture. Our primary end point was the need for TBI specific interventions in 3 groups of patients: 1) direct admission to the L1TC (L1TC group), 2) those admitted at one of the 4 CH (CH group), and 3) those transferred from CH to L1TC (TRANSFER group). TBI-specific interventions were defined as intracranial pressure monitor (ICP) placement, hyperosmolar therapy, or neurosurgical operation. Our secondary aim was to demonstrate that these patients can be safely managed in Community Hospitals with qualified Trauma teams. We also sought to identify the clinical outcomes in these three groups of patients - in terms of mortality and complications.

RESULTS

A total of 191 patients were included - 39 CH, 64 L1TC and 88 TRANSFER. There was no difference among the groups in terms of TBI-specific interventions: one TRANSFER, four L1TC, and no CH patients required hyperosmolar therapy (p = 0.277). None of the patients required placement of an intracranial pressure monitoring device (ICP) or a neurosurgical operation and complications and mortality rates were similar among the groups.

CONCLUSIONS

Patients with mild TBI and minor findings on head CT can be safely managed at CH with qualified Trauma Teams.

LEVEL OF EVIDENCE

Therapeutic/Care Management Study, Level IVhbv.

Determination of the full deformation tensor by multi-Bragg fast scanning nano X-ray diffraction

This work showcases a method to map the full deformation tensor in a single micro-sized crystal. It is shown that measuring the position of two Bragg reflections in reciprocal space is sufficient to obtain the full deformation tensor, if the condition of incompressibility of the material is imposed. This method is used to reveal the surface tension induced deformation at the edges of an as-grown single-crystal VO2 microwire. All components of the deformation tensor of the microwire were measured down to an absolute value of 10−4 in an 8 × 14 µm projected area of the wire. With a beam-defined spatial resolution of 150 × 150 nm, the measurement time was merely 2.5 h.

P1777Concordance and discordance among the recommended echocardiographic parameters for the assessment of mitral regurgitation severity

Background

The EACVI and ACC/AHA guidelines recommend assessing several echocardiographic parameters when evaluating mitral regurgitant severity. In a given patient, these parameters can be discordant making the assessment of mitral regurgitation challenging.

Purpose

To assess the degree to which echocardiographic parameters of MR severity are concordant.

Methods

This analysis included 131 consecutive patients with primary mitral regurgitation enrolled in a prospective multicenter study. Nine parameters were included in this analysis (PISA –derived regurgitant volume, PISA-derived EROA, vena contracta, color Doppler jet/LA area, LA volume index, LVEDVI, peak E wave, pulmonary vein systolic flow reversal, and presence of flail leaflet). Each echocardiographic parameter was determined to represent severe or nonsevere mitral regurgitation according to the guidelines. A concordance score was calculated as: (the number of concordant parameters/9) * 100 so that a higher score reflects greater concordance. Each echocardiogram was graded as having mild, moderate, or severe mitral regurgitation using the guideline recommended integrated approach.

Results

The mean concordance score was 74±13% for the entire cohort. There were 4 (4%) patients with complete agreement of all parameters and 32 (25%) with agreement of 5 of the 9 parameters. There was greater discordance in patients with severe MR and eccentric jets but no difference between patients with prolapse or flail leaflets (Figure 1). Clinical predictors of discordance were vena contracta and the peak E wave.

Figure 1

Conclusion

In this series, there was imperfect concordance between the recommended echocardiographic parameters of MR severity in patients undergoing evaluation for mitral regurgitation. The discordance was worse with more severe mitral regurgitation and there was no ideal predictor of discordance. These findings highlight the challenges facing echocardiographers when assessing the severity of mitral regurgitation and underscore the importance of using the integrated approach recommended by professional societal guidelines.

Acknowledgement/Funding

None

Strained Bottlebrushes in Super-Soft Physical Networks

ABA triblock copolymers composed of a poly(dimethylsiloxane) (PDMS) bottlebrush central block and linear poly(methyl methacrylate) (PMMA) terminal blocks self-assemble into a physical network of PDMS bottlebrush strands connected by PMMA spherical domains. A combination of small- and ultrasmall-angle X-ray scattering techniques was used to concurrently examine dimensions of PMMA spherical domains and PDMS bottlebrush strands both in the bulk and at the PMMA-PDMS interface. In agreement with scaling model predictions, the degrees of polymerization of the bottlebrush backbone (n_bb) and PMMA block (n_A) correlate with the measured PMMA domain size and area per molecule at the PMMA-PDMS interface as D_A ∝ (n_bbn_A)^1/3 and S ∝ n_A^2/3n_bb^-1/3, respectively. In the bulk, bottlebrush strands are extended due to steric repulsion between the side chains and unfavorable interactions between the different blocks. At the PMMA-PDMS interface with large curvature, packing constraints require additional bottlebrush backbone extension and alignment of side chains along the backbone in the direction perpendicular to the interface.

Hierarchical architecture of spider attachment setae reconstructed from scanning nanofocus X-ray diffraction data

When sitting and walking, the feet of wandering spiders reversibly attach to many surfaces without the use of gluey secretions. Responsible for the spiders' dry adhesion are the hairy attachment pads that are built of specially shaped cuticular hairs (setae) equipped with approximately 1 µm wide and 20 nm thick plate-like contact elements (spatulae) facing the substrate. Using synchrotron-based scanning nanofocus X-ray diffraction methods, combining wide-angle X-ray diffraction/scattering and small-angle X-ray scattering, allowed substantial quantitative information to be gained about the structure and materials of these fibrous adhesive structures with 200 nm resolution. The fibre diffraction patterns showed the crystalline chitin chains oriented along the long axis of the attachment setae and increased intensity of the chitin signal dorsally within the seta shaft. The small-angle scattering signals clearly indicated an angular shift by approximately 80° of the microtrich structures that branch off the bulk hair shaft and end as the adhesive contact elements in the tip region of the seta. The results reveal the specific structural arrangement and distribution of the chitin fibres within the attachment hair's cuticle preventing material failure by tensile reinforcement and proper distribution of stresses that arise upon attachment and detachment.

What Thermal Analysis Can Tell Us About Melting of Semicrystalline Polymers: Exploring the General Validity of the Technique

Thermal characterization of semicrystalline polymers can constitute a difficult task due to the metastable nature of polymer crystals. It is well documented that polymer structure can reorganize during the thermoanalytical experiment. It has become also clear that thermal analysis alone cannot discriminate the reorganization processes from multiple melting events. Therefore, instead of studying the initial sample state the measurements may simply reflect the structural evolution uncontrollably occurring during the experiment. Here an original setup combining in situ ultrafast chip calorimetry with millisecond time-resolved X-ray scattering is used to find the structural signature of the reorganization processes. The information is further used to construct the heating-rate versus crystallization-temperature reorganization (HR-CT-R) diagram. The diagram allows rationally designing thermoanalytical experiments in which one can completely exclude uncontrolled evolution of the semicrystalline structure. For a typical aromatic polyester, poly(trimethylene terephthalate), the critical heating rate above which all reorganization processes cease to exist can reach 1000 K/s and more.

Emergency Surgery Score Accurately Predicts the Risk of Post-Operative Infection in Emergency General Surgery

BACKGROUND

The Emergency Surgery Score (ESS) was validated recently as an accurate and user-friendly post-operative mortality risk calculator specific for Emergency General Surgery (EGS). ESS is calculated by adding one to three integer points for each of 22 pre-operative variables (demographics, co-morbidities, and pre-operative laboratory values); increasing scores accurately and gradually predict higher mortality rates. We sought to evaluate whether ESS can predict the occurrence of post-operative infectious complications in EGS patients.

PATIENTS AND METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2007-2015, all EGS patients were identified by using the "emergent" ACS-NSQIP variable and a concomitant surgery Current Procedural Terminology code for "digestive system." Patients with any missing ESS variables or those who died within 72 hours from the surgical procedure were excluded. A composite variable, post-operative infection, was created and defined as the post-operative occurrence of one or more of the following: superficial, deep incisional or organ/space surgical site infection, surgical site disruption, pneumonia, sepsis, septic shock, or urinary tract infection. ESS was calculated for all included patients, and the correlation between ESS and post-operative infection was examined using c-statistics.

RESULTS

Of a total of 4,456,809 patients, 90,412 patients were included. The mean age of the population was 56 years, 51% were female, and 70% were white; 22% developed one or more post-operative infections, most commonly sepsis/septic shock (12.2%), surgical site infection (9%), and pneumonia (5.7%). The ESS gradually and consistently predicted infectious complications; post-operative infections developed in 7%, 24%, and 49% of patients with an ESS of 1, 5, and 10, respectively. The c-statistics for overall post-operative infection, post-operative sepsis/septic shock, and pneumonia were 0.73, 0.75, and 0.80, respectively.

CONCLUSION

The ESS accurately predicts the occurrence of post-operative infectious complications in EGS patients and could be used for pre-operative clinical decision-making as well as quality benchmarking of infection rates in EGS.

Performance of prenatal screening using maternal serum and ultrasound markers for Down syndrome in Chinese women: a systematic review and meta-analysis

BACKGROUND

Controversies about the performance of conventional prenatal screening using maternal serum and ultrasound markers (PSMSUM) in detecting Down syndrome (DS) have been raised as a result of a recently available noninvasive prenatal test based on cell-free fetal DNA sequencing.

OBJECTIVES

To evaluate the screening performance of PSMSUM in detecting DS in Chinese women.

SEARCH STRATEGY

An exhaustive literature search of MEDLINE, Embase, the Cochrane Library, ISI Web of Science and China BioMedical Disc.

SELECTION CRITERIA

Primary studies, published from January 2004 to November 2014, which examined the screening accuracy of PSMSUM in pregnant Chinese women, compared with a reference standard, either chromosomal verification or inspection of the newborn.

DATA COLLECTION AND ANALYSIS

Data were extracted as screening positive/negative results for Down and non-Down syndrome pregnancies, allowing estimation of sensitivities and specificities. Risks of bias within and across studies were assessed. Screening accuracy measures were pooled using a bivariate random effects regression model.

MAIN RESULTS

Seventy-eight studies, involving six categories of PSMSUM, were included. Second-trimester double serum [pooled sensitivity (SEN) = 0.80, pooled specificity (SPE) = 0.95] and triple-serum (pooled SEN = 0.79, pooled SPE = 0.96) screening were the predominant PSMSUM methods. The screening performances of these methods achieved the national standard but varied enormously across studies. First-trimester combined screening (pooled SEN = 0.92, pooled SPE = 0.93) and second-trimester quadruple serum screening (median SEN = 0.86, median SPE = 0.96) performed better, but were rarely used.

AUTHOR'S CONCLUSIONS

Second-trimester maternal serum screening has the potential to achieve satisfactory screening performance in middle- and low-income countries. The reported enormous range in screening performance of second-trimester PSMSUM calls for urgent implementation of methods for performance optimization.

TWEETABLE ABSTRACT

Meta-analysis results show good accuracy of maternal serum and ultrasound screening for trisomy 21 in Chinese women.

Variation of Opioid Prescribing Patterns among Patients undergoing Similar Surgery on the Same Acute Care Surgery Service of the Same Institution: Time for Standardization?

BACKGROUND

Diversion of unused prescription opioids is a major contributor to the current United States opioid epidemic. We aimed to study the variation of opioid prescribing in emergency surgery.

METHODS

Between October 2016 and March 2017, all patients undergoing laparoscopic appendectomy, laparoscopic cholecystectomy, or inguinal hernia repair in the acute care surgery service of 1 academic center were included. For each patient, we systematically reviewed the electronic medical record and the prescribing pharmacy platform to identify: (1) history of opioid abuse, (2) opioid intake 3 months preoperatively, (3) number of opioid pills prescribed, (4) prescription of nonopioid pain medications (eg, acetaminophen, ibuprofen), and (5) the need for opioid prescription refills. The mean and range of opioid pills prescribed, as well as their oral morphine equivalent, were calculated.

RESULTS

A total of 255 patients were included (43.5% laparoscopic appendectomy, 44.3% laparoscopic cholecystectomy, and 12.1% inguinal hernia repair). The mean age was 47.5 years, 52.1% were female, 11.4% had a history of opioid use, and 92.5% received opioid prescriptions upon hospital discharge. Only 70.9% of patients were instructed to use nonopioid pain medications. The mean and range of opioid pills prescribed were 17.4; 0-56 (laparoscopic appendectomy), 17.1; 0-75 (laparoscopic cholecystectomy), and 20.9; 0-50 (inguinal hernia repair), while the range of prescribed oral morphine equivalent was 0-600 mg for laparoscopic appendectomy/laparoscopic cholecystectomy and 0-375 mg for inguinal hernia repair. No patients required any opioid medication refills.

CONCLUSION

Even within the same surgical service, wide variation of opioid prescription was observed. Guidelines that standardize pain management may help prevent opioid overprescribing.

Borderline resectable pancreatic cancer: conceptual evolution and current approach to image-based classification

Background

Diagnostic imaging plays a critical role in the initial diagnosis and therapeutic monitoring of pancreatic adenocarcinoma. Over the past decade, the concept of 'borderline resectable' pancreatic cancer has emerged to describe a distinct subset of patients existing along the spectrum from resectable to locally advanced disease for whom a microscopically margin-positive (R1) resection is considered relatively more likely, primarily due to the relationship of the primary tumor with surrounding vasculature.

Materials and methods

This review traces the conceptual evolution of borderline resectability from a radiological perspective, including the debates over the key imaging criteria that define the thresholds between resectable, borderline resectable, and locally advanced or metastatic disease. This review also addresses the data supporting neoadjuvant therapy in this population and discusses current imaging practices before and during treatment.

Results

A growing body of evidence suggests that the borderline resectable group of patients may particularly benefit from neoadjuvant therapy to increase the likelihood of an ultimately margin-negative (R0) resection. Unfortunately, anatomic and imaging criteria to define borderline resectability are not yet universally agreed upon, with several classification systems proposed in the literature and considerable variance in institution-by-institution practice. As a result of this lack of consensus, as well as overall small patient numbers and lack of established clinical trials dedicated to borderline resectable patients, accurate evidence-based diagnostic categorization and treatment selection for this subset of patients remains a significant challenge.

Conclusions

Clinicians and radiologists alike should be cognizant of evolving imaging criteria for borderline resectability given their profound implications for treatment strategy, follow-up recommendations, and prognosis.

Chameleon-like elastomers with molecularly encoded strain-adaptive stiffening and coloration

Active camouflage is widely recognized as a soft-tissue feature, and yet the ability to integrate adaptive coloration and tissuelike mechanical properties into synthetic materials remains elusive. We provide a solution to this problem by uniting these functions in moldable elastomers through the self-assembly of linear-bottlebrush-linear triblock copolymers. Microphase separation of the architecturally distinct blocks results in physically cross-linked networks that display vibrant color, extreme softness, and intense strain stiffening on par with that of skin tissue. Each of these functional properties is regulated by the structure of one macromolecule, without the need for chemical cross-linking or additives. These materials remain stable under conditions characteristic of internal bodily environments and under ambient conditions, neither swelling in bodily fluids nor drying when exposed to air.