Statistics of Gaussian polymer chains in harmonic applied fields.

The model of an ideal polymer chain in a harmonic applied field has broad applicability in situations involving polymer confinement and deformation due to applied stress. In this work we (1) formulate a general analytical model for a continuous Gaussian chain under a harmonic applied potential and (2) evaluate the statistical mechanics of this model given the potential, obtaining partition functions and moment generating functions (MGFs) that describe the chain configurations. Closed-form expressions for the squared radius of gyration, potential energy, partition function, and MGF for the center of mass are obtained for a general and multidimensional harmonic field. The expressions are compared with results of Monte Carlo simulations of a discrete Gaussian chain as well as results for related systems obtained from the literature. The theory derived here is used to test the applicability of the current model assumptions to relations from the literature describing polymer confinement and deformation in experiment, theory, and simulations.

Mechanisms of Shock Dissipation in Semicrystalline Polyethylene.

Semicrystalline polymers are lightweight, multiphase materials that exhibit attractive shock dissipation characteristics and have potential applications as protective armor for people and equipment. For shocks of 10 GPa or less, we analyzed various mechanisms for the storage and dissipation of shock wave energy in a realistic, united atom (UA) model of semicrystalline polyethylene. Systems characterized by different levels of crystallinity were simulated using equilibrium molecular dynamics with a Hugoniostat to ensure that the resulting states conform to the Rankine-Hugoniot conditions. To determine the role of structural rearrangements, order parameters and configuration time series were collected during the course of the shock simulations. We conclude that the major mechanisms responsible for the storage and dissipation of shock energy in semicrystalline polyethylene are those associated with plastic deformation and melting of the crystalline domain. For this UA model, plastic deformation occurs primarily through fine crystallographic slip and the formation of kink bands, whose long period decreases with increasing shock pressure.

Exploration of Ward-Based Nurses' Perspectives on Their Preparedness to Recognize Clinical Deterioration: A Scoping Review.

BACKGROUND: Despite initiatives in the early recognition of clinical deterioration, the incidence of failure to recognize clinical deterioration in patients continues to occur contributing to the ongoing rise of in-hospital mortality and morbidity. OBJECTIVE: The aim of the study was to explore and appraise the research evidence that related to ward-based nurses' preparedness to recognize the clinically deteriorating patient. METHODS: A scoping review was undertaken as this approach enabled the researchers to investigate the breadth of the available evidence through broad inclusion criteria. A comprehensive database search was conducted through the Cochrane Library; Cumulative Index to Nursing and Allied Health Literature; MEDLINE; ProQuest; PubMed; and Wiley Online Library. Each article was critically appraised and analyzed using a critical appraisal tool and thematic analysis, respectively. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews checklist. RESULTS: Twelve primary sources of literature met the eligibility criteria. Through thematic analyses 6 primary themes were identified: implication of experience on preparedness; interprofessional and intraprofessional relationships; knowledge of calling criteria, process and procedures; requirement for a supportive system and culture; existence of hierarchy within healthcare impacting care; and clinical deterioration as an education opportunity. CONCLUSIONS: This review identified central issues that impacted on ward-based nurses' preparedness. Further development of collaborative, supportive professional relationships across-and-within disciplines is needed. Effective use of clinical deterioration situations as educational opportunities would also assist nurses' preparedness through skill and knowledge development. However, more research evidence will be needed because of the limited data available on the topic.

Chronic unrelenting cough secondary to pericardial cyst impingement of right phrenic nerve.

Located in the mediastinum, pericardial cysts are rare and benign congenital abnormalities commonly identified as incidental findings on imaging. However, some patients with abnormally enlarged cysts present with compressive symptoms, which include recurrent infections, tamponade from cardiac compression and respiratory complications. Our report highlights a challenging case of a patient with recurrent respiratory symptoms secondary to phrenic nerve compression. Misdiagnosis over the past decade resulted in ineffective interventions. After clear identification of the cyst compression of the ipsilateral phrenic nerve, the patient underwent a minimally invasive robotically assisted cyst resection with phrenic nerve preservation that alleviated respiratory symptoms.

Computational ethics.

Technological advances are enabling roles for machines that present novel ethical challenges. The study of 'AI ethics' has emerged to confront these challenges, and connects perspectives from philosophy, computer science, law, and economics. Less represented in these interdisciplinary efforts is the perspective of cognitive science. We propose a framework - computational ethics - that specifies how the ethical challenges of AI can be partially addressed by incorporating the study of human moral decision-making. The driver of this framework is a computational version of reflective equilibrium (RE), an approach that seeks coherence between considered judgments and governing principles. The framework has two goals: (i) to inform the engineering of ethical AI systems, and (ii) to characterize human moral judgment and decision-making in computational terms. Working jointly towards these two goals will create the opportunity to integrate diverse research questions, bring together multiple academic communities, uncover new interdisciplinary research topics, and shed light on centuries-old philosophical questions.

Knowledge, belief, and moral psychology.

Phillips et al. make a strong case that knowledge representations should play a larger role in cognitive science. Their arguments are reinforced by comparable efforts to place moral knowledge, rather than moral beliefs, at the heart of a naturalistic moral psychology. Conscience, Kant's synthetic a priori, and knowledge attributions in the law all point in a similar direction.

Erratum: Machine Learning Enables Accurate Prediction of Asparagine Deamidation Probability and Rate.

[This corrects the article DOI: 10.1016/j.omtm.2019.09.008.].

Spontaneous Subcutaneous Emphysema and Pneumomediastinum in COVID-19 Patients: An Indicator of Poor Prognosis?

BACKGROUND Novel Coronavirus 2019 (COVID-19) has been in the spotlight since the first cases were reported in December 2019. COVID-19 has been found to cause severe acute respiratory distress syndrome and, more uncommonly, subcutaneous emphysema and pneumomediastinum. We present a case series of 3 patients with COVID-19 infection managed in the Intensive Care Unit and found to have subcutaneous emphysema and pneumomediastinum on chest imaging. CASE REPORT We present a case series of 3 men, ages 36, 47, and 78 years, diagnosed with COVID-19 via RT-PCR, found to have severe acute respiratory distress syndrome, and managed in the Intensive Care Unit. Two patients described in this case series were mechanically ventilated on low positive end-expiratory pressures and developed subcutaneous emphysema and pneumomediastinum on chest imaging, and 1 patient developed subcutaneous emphysema prior to intubation. Each of these patients had a more eventful hospital course and worse outcomes than most COVID-19 infected patients. CONCLUSIONS Subcutaneous emphysema and pneumomediastinum in COVID-19 patients have been rarely reported and is poorly understood. In our institution, we have found the diagnosis of subcutaneous emphysema and pneumomediastinum in COVID-19 patients is associated with unfavorable outcomes and worse prognosis.

Carcinoid tumor of lung and BRCA mutation: a case report.

BACKGROUND: A BRCA mutation is a mutation in either of the BRCA1 or BRCA2 genes, which are tumor suppressor genes. Hundreds of different types of mutations in these genes have been identified, some of which have been determined to be harmful, whereas others have no proven impact. BRCA mutations are well known to be associated with breast, uterine, and ovarian cancers along with some nongynecological malignancies involving the peritoneum, prostate, pancreas, skin, stomach, and rectum. However, there are no reported cases to date of an association between carcinoid tumors and a BRCA mutation. CASE PRESENTATION: Our patient was a 33-year-old White woman with BRCA2 mutation who presented to her primary care physician for evaluation of abdominal pain. She underwent computed tomography of her abdomen and pelvis, which showed an incidental finding of infrahilar mass along with renal stones. Further workup with bronchoscopy and biopsy of the mass confirmed it to be a carcinoid tumor of the lung. CONCLUSIONS: No literature thus far exists describing a connection between BRCA mutations and carcinoid tumors. Early diagnosis and prompt treatment of carcinoid tumors are proven to have impact on survival and prognosis of these patients.

Do User-Applied Safety Labels on Medication Syringes Reduce the Incidence of Medication Errors During Rapid Medical Response Intervention for Deteriorating Patients in Wards? A Systematic Search and Review.

INTRODUCTION: Intravenous medication errors (MEs) occur during medical emergency situations. An initiative, not yet in common practice, that could address these errors is safety labeling. The aim of this review was to identify and appraise research evidence related to the impact of user-applied medication safety labeling on reducing the incidence of MEs during rapid medical response intervention for patient deterioration in the ward setting. METHODS: A systematic search and review framework was used to conduct the review. A comprehensive database search was conducted of BioMed Central, Clinical Trials, Cumulative Index to Nursing and Allied Health Literature, Expanded Academic ASAP, Joanna Briggs Institute, MEDLINE, OVID, ProQuest Central, PubMed, Wiley Online Library, and World Health Organization Library. The Young and Solomon (2009) critical appraisal tool was used to critically appraise the identified research articles. Each article was then analyzed using a thematic network strategy to identify commonality. RESULTS: Four primary themes were identified; they were as follows: MEs occur during medical emergency responses (MERs); MEs occur throughout the medication administration process; MERs are stressful and are associated with MEs; and role of medication labeling in reducing MEs during MERs. DISCUSSION: Greater vigilance is required by health professionals during the medication administration process. The implementation of specific medication safety labeling into the MER could be beneficial in reducing the overall incidence of MEs. Further research is required to validate the merits of a MER medication safety labeling system.

Machine Learning Enables Accurate Prediction of Asparagine Deamidation Probability and Rate.

The spontaneous conversion of asparagine residues to aspartic acid or iso-aspartic acid, via deamidation, is a major pathway of protein degradation and is often seriously disruptive to biological systems. Deamidation has been shown to negatively affect both in vitro stability and in vivo biological function of diverse classes of proteins. During protein therapeutics development, deamidation liabilities that are overlooked necessitate expensive and time-consuming remediation strategies, sometimes leading to termination of the project. In this paper, we apply machine learning to a large (n = 776) liquid chromatography-tandem mass spectrometry (LC-MS/MS) dataset of monoclonal antibody peptides to create computational models for the post-translational modification asparagine deamidation, using the random decision forest method. We show that our categorical model predicts antibody deamidation with nearly 5% increased accuracy and 0.2 MCC over the best currently available models. Surprisingly, our model also paces or outperforms advanced and conventional models on an independent non-antibody dataset. In addition to deamidation probability, we are able to accurately predict deamidation rate (R2 = 0.963 and Q2 = 0.822), a capability with no peer in current models. This method should enable significant improvement in protein candidate selection, especially in biopharmaceutical development, and can be applied with similar accuracy to enzymes, monoclonal antibodies, next-generation formats, vaccine component antigens, and gene therapy vectors such as adeno-associated virus.

Presumed innocent? How tacit assumptions of intentional structure shape moral judgment.

The presumption of innocence is not only a bedrock principle of American law, but also a fundamental human right. The psychological underpinnings of this presumption, however, are not well understood. To make progress, one important task is to explain how adults and children infer the goals and intentional structure of complex actions, especially when a single action has more than one salient effect. Many theories of moral judgment have either ignored this intention inference problem or have simply assumed a particular solution without empirical support. We propose that this problem may be solved by appealing to domain-specific prior knowledge that is either built-up over the probability of prior intentions or built-in as part of core cognition. We further propose a specific solution to this problem in the moral domain: a good intention prior, which entails a rebuttable presumption that if an action has both good and bad effects, the actor intends the good effects and not the bad effects. Finally, in a series of novel experiments we provide the first empirical support - from both adults and preschool children - for the existence of this good intention prior. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The Mental Representation of Human Action.

Various theories of moral cognition posit that moral intuitions can be understood as the output of a computational process performed over structured mental representations of human action. We propose that action plan diagrams-"act trees"-can be a useful tool for theorists to succinctly and clearly present their hypotheses about the information contained in these representations. We then develop a methodology for using a series of linguistic probes to test the theories embodied in the act trees. In Study 1, we validate the method by testing a specific hypothesis (diagrammed by act trees) about how subjects are representing two classic moral dilemmas and finding that the data support the hypothesis. In Studies 2-4, we explore possible explanations for discrete and surprising findings that our hypothesis did not predict. In Study 5, we apply the method to a less well-studied case and show how new experiments generated by our method can be used to settle debates about how actions are mentally represented. In Study 6, we argue that our method captures the mental representation of human action better than an alternative approach. A brief conclusion suggests that act trees can be profitably used in various fields interested in complex representations of human action, including law, philosophy, psychology, linguistics, neuroscience, computer science, robotics, and artificial intelligence.

Correction: Manipulation of cell adhesion and dynamics using RGD functionalized polymers.

Correction for 'Manipulation of cell adhesion and dynamics using RGD functionalized polymers' by Juyi Li et al., J. Mater. Chem. B, 2017, DOI: .

Manipulation of cell adhesion and dynamics using RGD functionalized polymers.

We have successfully synthesized an ABA tri-block co-polymer of poly(methacrylic acid)-block-poly(2-hydroxyethyl methacrylate)-block-poly(methacrylic acid), having Mw = 100k and 272k where we were able to insert RDG or RGD peptide sequences using thiol-acrylate Michael addition. A soft silicone stamp was then used to imprint a 0.4-micron wide grating of the copolymer with a period of 10 microns. The samples were then examined with atomic force microscopy after application of an external electric field and the pattern was observed to stretch by a factor of five. Cells plated onto these substrates showed clear preference for the striped patterns formed under the influence of the external field, and no preferential attachment to the patterns formed in the absence of the field. Cell migration experiments, using the agarose droplet method, performed on spun cast copolymer films showed minimal migration and adhesion on the substrates without peptides or those with only with the RDG peptide, while good adhesion and significant outward migration was observed for cells plated on the copolymers with the RGD sequence. Taken together these results confirmed our hypothesis that a smart biomimetic polymer substrate could be constructed where functional domains could be revealed selectively allowing us to mimic the natural design of engineered tissue constructs.

Your theory of the evolution of morality depends upon your theory of morality.

Baumard et al. attribute to humans a sense of fairness. However, the properties of this sense are so underspecified that the evolutionary account offered is not well-motivated. We contrast this with the framework of Universal Moral Grammar, which has sought a descriptively adequate account of the structure of the moral domain as a precondition for understanding the evolution of morality.

Chlorthalidone: the forgotten diuretic.

Chlorthalidone's safety and efficacy in the management of hypertension has been demonstrated in landmark trials. Despite understanding the effects of thiazides on urinary sodium excretion and intravascular volume, the exact mechanism of their antihypertensive effects is not clearly understood. Common compensatory mechanisms for decreases in circulating plasma volume include increased adrenergic tone and systemic vascular resistance, as well as increases in the renin-angiotensin-aldosterone system. Chlorthalidone has been shown to decrease platelet aggregation and vascular permeability and promote angiogenesis in vitro, which is thought to be, in part, the result of reductions in carbonic anhydrase-dependent pathways, including catecholamine-mediated platelet aggregation and downregulation of VEGF-C gene expression. This article reviews the comparative clinical data between chlorthalidone and hydrochlorothiazide, the pharmacologic properties that might explain some of their differences regarding half-life and efficacy, and what is known about the effect of chlorthalidone on intermediate endpoints.

Universal moral grammar: theory, evidence and the future.

Scientists from various disciplines have begun to focus attention on the psychology and biology of human morality. One research program that has recently gained attention is universal moral grammar (UMG). UMG seeks to describe the nature and origin of moral knowledge by using concepts and models similar to those used in Chomsky's program in linguistics. This approach is thought to provide a fruitful perspective from which to investigate moral competence from computational, ontogenetic, behavioral, physiological and phylogenetic perspectives. In this article, I outline a framework for UMG and describe some of the evidence that supports it. I also propose a novel computational analysis of moral intuitions and argue that future research on this topic should draw more directly on legal theory.