bluuebunny/crossref_metadata_2025 huggingface dataset:
Delivering bad news
Authors: Nunn Kenneth
Published: April 2019

News in medicine has an obligation to be helpful, accurate, comprehensible for the intended audience and part of an on‐going professional relationship that enables the best outcomes available. These obligations have special poignancy when the news is bad, the patient is a child and the news scene is a busy medical practice, clinic or hospital. This paper aims to outline specific ways of being helpful when delivering bad news, within the constraints of daily practice, to a wide variety of developmentally different children at different stages in the family life cycle. The paper specifies the purpose, tasks, obstacles and practicalities of giving adverse information about the health of children in our clinical work. Adverse news needs to be embedded within delivering news more generally in our work. This presupposes a trusting relationship, an accurate understanding of the news to be delivered and a capacity to communicate medical complexity to the intended audience. There are multiple audiences for our medical news, at different developmental stages, each of whom needs help to ‘hear the news’ in different ways. Each developmental period within a broader family life cycle is briefly addressed. The limited evidence‐base is outlined with a view to what the clinician can do to foster maximal support, understanding and on‐going cooperation. The interplay between realism and optimism is highlighted so that accuracy and helpfulness are wedded as meaningfully and sensitively as possible. The aim is to be helpful rather than pursue an ideal of the unfaltering, polished and flawlessly performing clinician.
Definition of excessive daytime sleepiness in the general population: Feeling sleepy relates better to sleep‐related symptoms and quality of life than the Epworth Sleepiness Scale score. Results from an epidemiological study
Authors: Thorarinsdottir Elin H. , Bjornsdottir Erla , Benediktsdottir Bryndis , Janson Christer , Gislason Thorarinn , Aspelund Thor , Kuna Samuel T. , Pack Allan I. , Arnardottir Erna S.
Published: April 2019

Many different subjective tools are being used to measure excessive daytime sleepiness (EDS) but the most widely used is the Epworth Sleepiness Scale (ESS). However, it is unclear if using the ESS is adequate on its own when assessing EDS. The aim of this study was to estimate the characteristics and prevalence of EDS using the ESS and the Basic Nordic Sleep Questionnaire (BNSQ) in general population samples. Participants aged 40 years and older answered questions about sleepiness, health, sleep‐related symptoms and quality of life. Two groups were defined as suffering from EDS: those who scored >10 on the ESS (with increased risk of dozing off) and those reporting feeling sleepy during the day ≥3 times per week on the BNSQ. In total, 1,338 subjects (53% male, 74.1% response rate) participated, 13.1% reported an increased risk of dozing off, 23.2% reported feeling sleepy and 6.4% reported both. The prevalence of restless leg syndrome, nocturnal gastroesophageal reflux, difficulties initiating and maintaining sleep and nocturnal sweating was higher among subjects reporting feeling sleepy compared to non‐sleepy subjects. Also, subjects reporting feeling sleepy had poorer quality of life and reported more often feeling unrested during the day than non‐sleepy subjects. However, subjects reporting increased risk of dozing off (ESS > 10) without feeling sleepy had a similar symptom profile as the non‐sleepy subjects. Therefore, reporting only risk of dozing off without feeling sleepy may not reflect problematic sleepiness and more instruments in addition to ESS are needed when evaluating daytime sleepiness.
Mechanical dilation, botulinum toxin A injection, and surgical myotomy with fundoplication for treatment of lower esophageal sphincter achalasia‐like syndrome in dogs
Authors: Grobman M. E , Hutcheson K. D. , Lever T. E. , Mann F. A. , Reinero C. R.
Published: April 2019

Background

Megaesophagus (ME) carries a poor long‐term prognosis in dogs. In people, lower esophageal sphincter (LES) achalasia is a rare cause of ME that may respond to targeted intervention. Dogs with lower esophageal sphincter achalasia‐like syndrome (LES‐AS) have been described recently, warranting investigation of analogous targeted treatment.

Hypothesis/Objectives

Evaluate response of dogs with LES‐AS to LES mechanical dilation and botulinum toxin A (BTA) injections, with or without surgical myotomy and fundoplication. We hypothesized that clinical and videofluoroscopic swallow study (VFSS) features of LES‐AS would improve after treatment targeting functional LES obstruction.

Animals

Fourteen client‐owned dogs with LES‐AS diagnosed by VFSS.

Methods

Retrospective study. Dogs diagnosed with LES‐AS underwent treatment between April 2015 and December 2017. Outcome measures included client perception of clinical severity, body weight (BW), body condition score (BCS), regurgitation frequency, and VFSS parameters (ME, esophageal motility, gastric filling). Dogs with positive responses were considered candidates for LES myotomy with fundoplication.

Results

By a median IQR of 21 (IQR, 14‐25) days after mechanical dilation and BTA, clients reported clinical improvement in 100% of dogs, BW increased 20.4% (IQR, 12.7%‐25%), pre‐ and post‐treatment BCS was 3 (IQR, 3‐4) and 5 (IQR, 4‐5), respectively, and frequency of regurgitation decreased by 80% (IQR, 50%‐85%). Duration of effect was 40 (IQR, 17‐53) days. Despite clinical improvement, ME and abnormal esophageal motility persisted in 14 dogs. Six dogs subsequently underwent myotomy and fundoplication and maintained improvement observed after mechanical dilation and BTA.

Conclusions and Clinical Importance

Dogs with LES‐AS experienced significant, temporary, clinical improvement after mechanical dilation and BTA. Preliminary results suggest myotomy with fundoplication provide lasting clinical benefit despite persistence of ME.
The Anthropology of Plastics: An Agenda for Local Studies of a Global Matter of Concern
Authors: Pathak Gauri , Nichter Mark
Published: April 2019

Anthropology has largely ignored plastics, even as they have emerged as the paradigmatic material—and problem—of our times. In this article, we make the case for an anthropology of plastics as a priority for environmental and medical anthropological research. Drawing from exploratory fieldwork in India, we briefly highlight the benefits and risks of different types of plastics, identify areas for anthropological investigations of human–plastic entanglements, and unpack major debates about plastic control. We recommend analyses that take into account the social life of plastics and the life cycle of plastic production, consumption, circulation, disposal, retrieval, and decomposition. We propose a facilitator role for anthropologists in bringing environmental NGOs and the plastic industry to the table to reduce the human and environmental health risks related to widespread reliance on plastics. Overall, we argue that anthropological analyses are urgently needed to address environmental and global health concerns related to plastics.
Inappropriate activation of pacemaker magnet response mode by CPAP masks
Authors: Schwartz Yosef , Wasserlauf Jeremiah , Sahakian Alan V. , Knight Bradley
Published: April 2019

Background

While electromagnetic interference is widely recognized as a cause of noise detected by cardiac implanted electronic devices (CIEDs), we report on two cases of inappropriate activation of magnet response mode due to magnets in continuous positive airway pressure (CPAP) masks.

Methods

Two patients with St. Jude Medical dual‐chamber pacemakers (Assurity DR 2240; St. Jude Medical, St. Paul, MN, USA) were discovered on routine outpatient device interrogation to have magnet response events that correlated with nightly use of their CPAP masks. A magnet response event was reproduced by positioning one CPAP mask over the patient's pulse generator site. The magnetic flux density was measured using a Gauss meter.

Results

It was found that their CPAP masks had magnetic clips that were used to secure the headgears. These appeared to be transiently positioned within sufficient proximity of the patients’ CIEDs to activate magnet response events during sleep. The measured magnetic field density adjacent to a mask magnet was 136 Gauss.

Conclusion

Clinicians managing CPAPs and CIEDs should be aware of magnetic interference with the potential for inappropriate activation of magnet response mode. CPAP masks that are secured with magnetic clips should be avoided in patients with CIEDs, since this can result in inappropriate asynchronous pacing in pacemakers or potential failure to deliver life‐saving tachytherapies in patients with implanted cardioverter‐defibrillators.
Atrioventricular conduction in patients undergoing pacemaker implant following self‐expandable transcatheter aortic valve replacement
Authors: Ghannam Michael , Cunnane Ryan , Menees Daniel , Grossman Michael P. , Chetcuti Stanley , Patel Himanshu , Deeb Michael , Jongnarangsin Krit , Pelosi Frank , Oral Hakan , Latchamsetty Rakesh
Published: April 2019

Background

Heart block requiring a pacemaker is common after self‐expandable transcatheter aortic valve replacement (SE‐TAVR); however, conduction abnormalities may improve over time. Optimal device management in these patients is unknown.

Objective

To evaluate the long‐term, natural history of conduction disturbances in patients undergoing pacemaker implantation following SE‐TAVR.

Methods

All patients who underwent new cardiac implantable electronic device (CIED) implantation at Michigan Medicine following SE‐TAVR placement between January 1, 2012 and September 25, 2017 were identified. Electrocardiogram and device interrogation data were examined during follow‐up to identify patients with recovery of conduction. Logistic regression analysis was used to compare clinical and procedural variables to predict conduction recovery.

Results

Following SE‐TAVR, 17.5% of patients underwent device placement for new atrioventricular (AV) block. Among 40 patients with an average follow‐up time of 17.1 ± 8.1 months, 20 (50%) patients had durable recovery of AV conduction. Among 20 patients without long‐term recovery, four (20%) had transient recovery. The time to transient conduction recovery was 2.2 ± 0.2 months with repeat loss of conduction at 8.2 ± 0.9 months. On multivariate analysis, larger aortic annular size (odds ratio: 0.53 [0.28–0.86]/mm, P = 0.02) predicted lack of conduction recovery.

Conclusions

Half of the patients undergoing CIED placement for heart block following SE‐TAVR recovered AV conduction within several months and maintained this over an extended follow‐up period. Some patients demonstrated transient recovery of conduction before recurrence of conduction loss. Larger aortic annulus diameter was negatively associated with conduction recovery.
Linking COPD epidemiology with pediatric asthma care: Implications for the patient and the physician
Authors: Melén Erik , Guerra Stefano , Hallberg Jenny , Jarvis Deborah , Stanojevic Sanja
Published: April 2019

What are the implications of a lower than expected forced expiratory volume in one second (FEV1) in childhood on respiratory health later in adulthood? Lung function is known to track with age, and there is evidence from recent epidemiologic studies that impaired lung function early in life is associated with later chronic airflow limitation, or even chronic obstructive pulmonary disease, COPD. This risk seems particularly strong in subjects with persistent and severe forms of childhood asthma. Can we translate findings from longitudinal cohort studies to individual risk predictions and preventive guidelines in our pediatric care? In this review, we discuss the clinical implementations of recent epidemiological respiratory studies and the importance of preserved lung health across the life course. Also, we evaluate available clinical tools, primarily lung function measures, and profiles of risk factors, including biomarkers, that may help identifying children at risk of chronic airway disease in adulthood. We conclude that translating population level results to the individual patient in the pediatric care setting is not straight forward, and that there is a need for studies specifically designed to evaluate performance of prediction of risk profiles for long‐term sequelae of childhood asthma and lung function impairment.
Pediatric dermatology and climate change: An argument for the pediatric subspecialist as public health advocate
Authors: Schachtel April , Boos Markus D.
Published: April 2019

The October 2018 report from the United Nations Intergovernmental Panel on Climate Change predicts significant threats to human health secondary to anthropogenic global warming; children have been and will continue to be disproportionately affected by these weather‐related changes. Multiple physician groups have acknowledged climate change as a public health issue, calling upon providers to educate their communities about this looming health crisis while also reducing their individual carbon footprints. A significant body of literature has also documented the adverse dermatologic consequences of a warmer planet, highlighting the importance of pediatric dermatologists in addressing climate change. Here, we summarize the rationale for the pediatric dermatologist as public health advocate, providing specific actionable items through which our specialty can positively address the climate change crisis and in turn protect the health of our patients now and in the future.
The Law: The Contours of Presidential Immunity
Authors: Tipler Kathleen
Published: April 2019

Can a sitting president be subpoenaed, indicted, or prosecuted for criminal activity? This article concludes that a president can be. Strong arguments for presidential immunity emphasize the unique position of a president in the constitutional order. Only Congress, advocates of immunity claim, can discipline presidential lawbreaking. However, arguments for presidential immunity depend upon contestable assumptions regarding the respective institutional authority of Congress and the judiciary. If institutional authority is viewed differently—and this article offers good reason to do so—then the contours of presidential immunity should be narrowly drawn so as to invite judicial intervention.
Baseline resting heart rate variability predicts post‐traumatic stress disorder treatment outcomes in adults with co‐occurring substance use disorders and post‐traumatic stress
Authors: Soder Heather E. , Wardle Margaret C. , Schmitz Joy M. , Lane Scott D. , Green Charles , Vujanovic Anka A.
Published: April 2019

Post‐traumatic stress disorder (PTSD) symptoms are highly prevalent among individuals with substance use disorders (SUD), presenting a difficult‐to‐treat, complex comorbidity. Prognostic factors for treatment outcomes may characterize heterogeneity of the treated population and/or implicate mechanisms of action that are salient for improving treatments. High frequency heart rate variability (HF‐HRV) is a suggested biomarker for emotion regulation—the ability to generate appropriate emotional responses via the influence of the parasympathetic nervous system on the heart. This initial study investigated the utility of baseline resting HF‐HRV for predicting PTSD symptoms and substance use outcomes following treatment of 37 SUD participants with comorbid PTSD symptoms. Participants completed either standard cognitive‐ behavioral therapy (CBT) for SUD or a novel treatment of integrated post‐traumatic stress and substance use that combined CBT for SUD with cognitive processing therapy for PTSD. Analyses demonstrated that higher HF‐HRV predicted greater reduction in PTSD symptoms following both types of treatment. This suggests prognostic value of HF‐HRV as a predictor of PTSD treatment outcomes; those with poorer autonomic emotional regulation may not respond as well to psychotherapy in general. This hypothesis‐generating analysis identifies a putative biomarker that might have utility in treatment prediction.
The history of Classical Hebrew: From the invention of the alphabet to the Mishnah
Authors: Schniedewind William M.
Published: April 2019

A lively debate has engulfed the study of the early history of the Hebrew language in the past two decades. Traditionally, scholars classified the language of the Hebrew Bible into three categories: Archaic, Standard, and Late Biblical Hebrew. But recent trends in biblical criticism have tended to date biblical literature much later, and some scholars date almost all of biblical literature to the Persian and Hellenistic periods. This trend undoes traditional linguistic categories for biblical Hebrew and questions the validity of the linguistic dating of biblical literature. In spite of the challenges, a modified and more complex model for the history of Classical Hebrew remains the working consensus model. A lively debate has engulfed the study of the early history of the Hebrew language in the past two decades, especially advanced by the work of Ian Young and Robert Rezetko (e.g., Young & Rezetko, ). Conferences have been organized to address this issue (e.g., Miller‐Naudé & Zevit, ). Young and Rezetko have continued to advocate for their approach in spite of critical reviews (e.g., Joosten, ). Traditionally, scholars have classified the language of the Hebrew Bible into three categories: Archaic Biblical Hebrew (that is, early biblical poems), Standard Biblical Hebrew (the major part of biblical literature), and Late Biblical Hebrew (comprising compositions from the Persian and Hellenistic periods). But trends in biblical criticism over the past several decades have tended to date biblical literature later and later. Now, one can find some prominent scholars who date almost all of biblical literature—and particularly Pentateuchal literature (Sommer, )—to the Persian and Hellenistic periods. This trend raises serious questions about the validity of the traditional linguistic dating of biblical literature. Although some have ignored this linguistic problem, others have offered a variety of rationales justifying the dismissal of linguistic dating. These divergent trends have resulted in continuing debate regarding the historical linguistics of Biblical Hebrew that is addressed in Ronald Hendel and Jan Joosten's recent book, How Old is the Hebrew Bible? (2018).
Surgical enlargement of the nasomaxillary aperture and transnasal conchotomy of the ventral conchal sinus: Two surgical techniques to improve sinus drainage in horses
Authors: Bach Fabienne Sabine , Böhler Alexandra , Schieder Katrin , Handschuh Stephan , Simhofer Hubert
Published: April 2019

Objective

To evaluate 2 surgical techniques for establishing and/or improving paranasal sinus drainage in cadaver heads and horses with sinusitis and evaluate the feasibility of postoperative transnasal sinus endoscopy.

Study design

Ex vivo study (equine cadaver heads) and case series.

Sample population

Nine adult equine cadaver heads and 8 horses with recurrent sinusitis.

Methods

For the ex vivo study, the following procedures were performed on 9 cadaver heads: preoperative and postoperative computed tomography (heads 1–6), endoscopy‐guided transnasal conchotomy of the ventral conchal sinus (TCVCS) and surgical enlargement of the nasomaxillary aperture (SENMAP) on opposite sides (heads 1–3), combined TCVCS and SENMAP on both sides (heads 4–9), evaluation of sinus drainage before and after surgery (heads 7–9), and postoperative transnasal endoscopy (heads 4–9). For the case series, 8 horses with secondary sinusitis were treated in standing position with SENMAP and/or TCVCS and postoperative transnasal endoscopy.

Results

Sinonasal communications were successfully created in all cadavers and affected live horses. Transnasal endoscopy of all sinuses except the middle conchal sinus was possible in heads 4–9 and in all clinical cases. Sinus drainage was improved (P = .028) by combining techniques. Blood loss in live horses ranged from 0.5–5.5 L (1.95 ± 1.5) per horse. Sinusitis resolved in all affected horses during follow‐up of 3.2–25.5 months (13.5 ± 8.5).

Conclusion

Transnasal conchotomy of the ventral conchal sinus and SENMAP consistently created large sinonasal communications, facilitating sinus endoscopy and improving sinus drainage.

Clinical significance

Transnasal conchotomy of the ventral conchal sinus and SENMAP are viable options to treat horses with sinusitis and anatomical obstructions of the sinonasal communications.
Geometric Manin’s conjecture and rational curves
Authors: Lehmann Brian , Tanimoto Sho
Published: April 2019

Let$X$be a smooth projective Fano variety over the complex numbers. We study the moduli space of rational curves on$X$using the perspective of Manin’s conjecture. In particular, we bound the dimension and number of components of spaces of rational curves on$X$. We propose a geometric Manin’s conjecture predicting the growth rate of a counting function associated to the irreducible components of these moduli spaces.
Congruences with Eisenstein series and -invariants
Authors: Bellaïche Joël , Pollack Robert
Published: April 2019

We study the variation of$\unicode[STIX]{x1D707}$-invariants in Hida families with residually reducible Galois representations. We prove a lower bound for these invariants which is often expressible in terms of the$p$-adic zeta function. This lower bound forces these$\unicode[STIX]{x1D707}$-invariants to be unbounded along the family, and we conjecture that this lower bound is an equality. When$U_{p}-1$generates the cuspidal Eisenstein ideal, we establish this conjecture and further prove that the$p$-adic$L$-function is simply a power of$p$up to a unit (i.e. $\unicode[STIX]{x1D706}=0$). On the algebraic side, we prove analogous statements for the associated Selmer groups which, in particular, establishes the main conjecture for such forms.
On the Influence of the Shoulder Kinematic Chain on Joint Kinematics and Musculotendon Lengths During Wheelchair Propulsion Estimated From Multibody Kinematics Optimization
Authors: Puchaud Pierre , Hybois Samuel , Lombart Antoine , Bascou Joseph , Pillet Hélène , Fodé Pascale , Sauret Christophe
Published: April 2019

Multibody kinematic optimization is frequently used to assess shoulder kinematics during manual wheelchair (MWC) propulsion, but multiple kinematics chains are available. It is hypothesized that these different kinematic chains affect marker tracking, shoulder kinematics, and resulting musculotendon (MT) lengths. In this study, shoulder kinematics and MT lengths obtained from four shoulder kinematic chains (open-loop thorax-clavicle-scapula-humerus (M1), closed-loop with contact ellipsoid (M2), scapula rhythm from regression equations (M3), and a single ball-and- socket joint between the thorax and the humerus (M4) were compared. Right-side shoulder kinematics from seven subjects were obtained with 34 reflective markers and a scapula locator using an optoelectronic motion capture system while propelling on a MWC simulator. Data were processed based on the four models. The results showed the impact of shoulder kinematic chains on all studied variables. Marker reconstruction errors were found to be similar between M1 and M2 and lower than for M3 and M4. Few degrees-of-freedom (DoF) were noticeably different between M1 and M2, but all shoulder DoFs were significantly affected between M1 and M4. As a consequence of differences in joint kinematics, MT lengths were affected by the kinematic chain definition. The contact ellipsoid (M2) was found as a good trade-off between marker tracking and penetration avoidance of the scapula. The regression-based model (M3) was less efficient due to limited humerus elevation during MWC propulsion, as well as the ball-and-socket model (M4) which appeared not suitable for upper limbs activities, including MWC propulsion.
Changes in Shear Modulus of the Lumbar Multifidus Muscle During Different Body Positions
Authors: Sadeghi Seyedali , Quinlan Kevin , Eilertson Kirsten E. , Billy Gregory G. , Bible Jesse , Sions Jaclyn Megan , Cortes Daniel H.
Published: April 2019

Multifidus function is important for active stabilization of the spine, but it can be compromised in patients with chronic low back pain and other spine pathologies. Force production and strength of back muscles are often evaluated using isometric or isokinetic tests, which lack the ability to quantify multifidi contribution independent of the erector spinae and adjacent hip musculature. The objective of this study is to evaluate localized force production capability in multifidus muscle using ultrasound shear wave elastography (SWE) in healthy individuals. Three different body positions were considered: lying prone, sitting up, and sitting up with the right arm lifted. These positions were chosen to progressively increase multifidus contraction and to minimize body motion during measurements. Shear modulus was measured at the superficial and deeper layers of the multifidus. Repeatability and possible sources of error of the shear modulus measurements were analyzed. Multifidus shear modulus (median (interquartile range)) increased from prone, i.e., 16.15 (6.69) kPa, to sitting up, i.e., 27.28 (15.72) kPa, to sitting up with the right arm lifted position, i.e., 45.02 (25.27) kPa. Multifidi shear modulus in the deeper layer of the multifidi was lower than the superficial layer, suggesting lower muscle contraction. Intraclass correlation coefficients (ICCs) for evaluation of shear modulus by muscle layer were found to be excellent (ICC = 0.76–0.80). Results suggest that the proposed protocol could quantify local changes in spinal muscle function in healthy adults; further research in patients with spine pathology is warranted.
Hyper-Reduction Over Nonlinear Manifolds for Large Nonlinear Mechanical Systems
Authors: Jain Shobhit , Tiso Paolo
Published: April 2019

Common trends in model reduction of large nonlinear finite element (FE)-discretized systems involve Galerkin projection of the governing equations onto a low-dimensional linear subspace. Though this reduces the number of unknowns in the system, the computational cost for obtaining the reduced solution could still be high due to the prohibitive computational costs involved in the evaluation of nonlinear terms. Hyper-reduction methods are then used for fast approximation of these nonlinear terms. In the finite element context, the energy conserving sampling and weighing (ECSW) method has emerged as an effective tool for hyper-reduction of Galerkin-projection-based reduced-order models (ROMs). More recent trends in model reduction involve the use of nonlinear manifolds, which involves projection onto the tangent space of the manifold. While there are many methods to identify such nonlinear manifolds, hyper-reduction techniques to accelerate computation in such ROMs are rare. In this work, we propose an extension to ECSW to allow for hyper-reduction using nonlinear mappings, while retaining its desirable stability and structure-preserving properties. As a proof of concept, the proposed hyper-reduction technique is demonstrated over models of a flat plate and a realistic wing structure, whose dynamics have been shown to evolve over a nonlinear (quadratic) manifold. An online speed-up of over one thousand times relative to the full system has been obtained for the wing structure using the proposed method, which is higher than its linear counterpart using the ECSW.
A Study on the Influences of Abrasive Media's Viscoelasticity on Entrance Effect in Abrasive Flow Machining
Authors: Wei Haibo , Wang Xuanping , Gao Hang , Peng Can , Wang Xuyue
Published: April 2019

Abrasive flow machining (AFM) is a nontraditional surface finishing method that finishes complex surface by pushing the abrasive media flow through the workpiece surface. The entrance effect that the material removal increases at the entrance of changing the cross-sectional flow channel is a difficult problem for AFM. In this paper, the effects of media rheological properties on the entrance effect are discussed. To explore the effects of the media's viscoelasticity on the entrance effect, two sets of media with different viscoelasticity properties are adopted to study their rheological and machining performances in the designed flow channel with a contraction area. The rheological properties are tested by frequency sweep and characterized by the Maxwell viscoelastic model and the Carreau viscous model. In the experiment, the variation of the profile height (ΔH) and the variation ratio of the roughness (ΔRa) on the workpiece surface are measured. Moreover, numerical simulation results under different constitutive equations are compared with the experimental results. It shows that the numerical simulation results of a viscoelastic model have a better agreement with the experimental results than the viscous model, and the increase of the viscoelasticity makes the entrance effect be exacerbated, which can be predicted by the viscoelastic numerical simulation.
Nonlinear Dynamics of Friction Heating in Ultrasonic Welding
Authors: Liu Zhiwei , Li Yang , Wang Yuefang , Kannatey-Asibu Elijah , Epureanu Bogdan I.
Published: April 2019

High temperature, short welding time, and low relative motion generate high bond quality in ultrasonic metal welding (USMW). Friction is considered to be the main heat source during USMW. Hence, a comprehensive and accurate understanding of friction heating has become particularly valuable for designing USMW processes and devices. However, stick, slip, and separation states may appear alternately in the welding zone between superimposed workpieces during USMW vibrations; hence, a strong nonlinear process is created. Furthermore, the structural dynamics and the heat transfer are highly coupled because material properties depend on temperature. In this research, we propose a fast and accurate numerical methodology to calculate the friction heating through a multiphysical approach integrating a nonlinear contact model, a nonlinear structural dynamics model, and a thermal model. The harmonic balance method and the finite element method are utilized to accelerate the simulation. Several experiments were performed with aluminum and copper workpieces under different clamping forces and vibration amplitudes to confirm the presented numerical method, resulting in a good match.
Design of Planar 1-DOF Cam-Linkages for Lower-Limb Rehabilitation Via Kinematic-Mapping Motion Synthesis Framework
Authors: Zhao Ping , Zhu Lihong , Zi Bin , Li Xiangyun
Published: April 2019

When designing linkage mechanisms for motion synthesis, many examples have shown that the optimal kinematic constraint on the task motion contains too large deviation to be approximately viewed as a single rotational or translational pair. In this paper, we seek to adopt our previously established motion synthesis framework for the design of cam-linkages for a more accurate realization, while still maintaining a 1-degree-of-freedom (DOF) mechanism. To determine a feasible cam to lead through the task motion, first a kinematic constraint is identified such that a moving point on the given motion traces a curve that is algebraically closest to a circle or a line. This leads to a cam with low-harmonic contour curve that is simple and smooth to avoid the drawbacks of cam mechanisms. Additional constraints could also be imposed to specify the location and/or size of the cam linkages. An example of the design of a lower-limb rehabilitation device has been presented at the end of this paper to illustrate the feasibility of our approach. It is shown that our design could lead the user through a normal walking motion.
An Extensible Orthopedic Wire Navigation Simulation Platform
Authors: Long Steven , Thomas Geb W. , Anderson Donald D.
Published: April 2019

The demand for simulation-based skills training in orthopedics is steadily growing. Wire navigation, or the ability to use 2D images to place an implant through a specified path in bone, is an area of training that has been difficult to simulate given its reliance on radiation-based fluoroscopy. Our group previously presented on the development of a wire navigation simulator for a hip fracture module. In this paper, we present a new methodology for extending the simulator to other surgical applications of wire navigation. As an example, this paper focuses on the development of an iliosacral wire navigation simulator. We define three criteria that must be met to adapt the underlying technology to new areas of wire navigation; surgical working volume, system precision, and tactile feedback. The hypothesis being that techniques, which fall within the surgical working volume of the simulator, demand a precision less than or equal to what the simulator can provide, and that require the tactile feedback offered through simulated bone can be adopted into the wire navigation module and accepted as a valid simulator for the surgeons using it. Using these design parameters, the simulator was successfully configured to simulate the task of drilling a wire for an iliosacral screw. Residents at the University of Iowa successfully used this new module with minimal technical errors during use.
Welding Residual Stress in HDPE Pipes: Measurement and Numerical Simulation
Authors: Sun Yu , Jia Yun-Fei , Haroon Muhammad , Lai Huan-sheng , Jiang Wenchun , Tu Shan-Tung
Published: April 2019

To understand the residual stress distribution in the welded joints of high density polyethylene (HDPE) pipes is essential to the assessment of its structural integrity. However, limited knowledge of their residual stress was available in this regard. In this paper, the hole-drilling strain-gage method was used to measure the residual stress in the welded seam of HDPE pipes, which was produced by the butt fusion welding technique. The finite element modeling using viscoelastic constitutive model with Prony series was carried out to determine the temperature field and corresponding stress field in the welding stages. The measured residual stress near the surface shows good consistency with the numerical results. It is shown that the residual stress in the hoop direction is much larger than those in the radial and axial directions. The effect of the pipe thickness on the residual stress distribution was also investigated by numerical simulation. The positions of the maximum tensile stress in the welded joints were found within the normalized depth region (the radial depth to the thickness) of 0.2 to 0.8.
Optimization of Rectangular Fins With Prime Surface and Bottom Convection
Authors: Falcão C. E. G. , dos Santos T.
Published: April 2019

The main goal of this work is to obtain semi-analytical solutions for the geometric optimization of fins considering the presence of a primary surface. Optimized fin dimensions devoted to finned surfaces are already available in the literature; however, these solutions have as assumption a known fin base temperature. In contrast, in many practical situations, employed fins are attached to a primary surface that has restricted dimensions due to design requirements. In these cases, the primary surface dimensions are kept fixed and the known condition is a temperature or convective condition prescribed on the primary surface boundary. For such scenarios, to the best of our knowledge, there are no simple analytical expressions derived in the literature. Thus, reasoning on this main problem, in the present work, analytical optimum expressions are derived in order to deal with this kind of applications. The obtained analytical equations are subsequently compared with optimum results acquired from numerical calculations. In summary, both analytical and numerical results show a good agreement. The main contribution of this work is to provide closed solutions for the mentioned optimization problem, thus allowing the construction of simple charts, facilitating the corresponding fin design process.
Conjugate Heat Transfer in a Microchannel Simultaneously Developing Gas Flow: A Vorticity Stream Function-Based Numerical Analysis
Authors: Ramadan K. M. , Kamil Mohammed , Bataineh M. S.
Published: April 2019

A simultaneously developing microchannel gas flow is analyzed numerically, using the vorticity–stream function form of the Navier–Stokes equation, together with the fluid energy equation and the solid wall heat conduction equation. Rarefaction, shear work, viscous dissipation, pressure work, axial conduction, and conjugate effects on heat transfer characteristics are investigated. The shear work contribution to the wall heat flux is evaluated in both the developing and the fully developed flow regions and compared with the conductive wall heat flux. The assumption of hydrodynamically fully developed, thermally developing flow—normally used in the analysis of channel heat transfer—is assessed and compared with the simultaneously developing flow case. Analytical expressions for the fluid flow and heat transfer parameters under fully developed conditions are also derived and compared with the numerical results for verification. The analysis presented shows that the shear work and the combined viscous dissipation and pressure work result in extending the thermal entrance length by far. Heat conduction in the wall also contributes to increase the thermal entry length. The results presented also demonstrate the shear work contribution to heat transfer in the slip flow regime, although minor in the very first portion of the thermal entrance length, and it becomes progressively more significant as the flow thermal development conditions are approached and turns out to be exactly equal in magnitude to the conductive wall heat flux in the thermally fully developed region, resulting in a zero Nusselt number, as verified by both the exact and numerical solutions.
Unintentional As incorporation into AlSb and interfacial layers within InAs/AlSb superlattices
Authors: Hu Yunong , Tam Man Chun , Wasilewski Zbigniew R.
Published: April 2019

The InAs/AlSb material system has proven to be an excellent choice for high-performance mid-infrared quantum cascade lasers. In this work, an unintentional displacement of Sb by residual As flux incident on the wafer was studied by direct monitoring of such flux during a simulated molecular beam epitaxy (MBE) growth sequence and dynamical simulations of high-resolution x-ray diffraction data collected on InAs/AlSb periodic structures grown under similar conditions. The results revealed that predominantly Al–As bonds detected at the InAs/AlSb interfaces, which were reported earlier, can be attributed to a residual bypass As flux on the wafer after closing the As shutter. Moreover, the experiments revealed that under typical growth conditions, AlSb binary barriers are converted into AlAsSb ternary layers with appreciable As content. The exact As content in the barriers is proportional to the effective As flux bypassing the closed shutter and thus depends on the particulars of the MBE system design and the exact As flux used for the growth of InAs wells.
Brilliance improvement of laser-produced extreme ultraviolet and soft x-ray plasmas based on pulsed gas jets
Authors: Holburg Jonathan , Müller Matthias , Mann Klaus , Wieneke Stephan
Published: April 2019

Two methods improving the brilliance of laser-induced plasmas emitting in the extreme UV (EUV) and soft x-ray (SXR) regions were investigated, using three different gases (nitrogen, krypton, and xenon) from a pulsed gas jet. Utilizing a newly designed piezoelectric valve, up to almost ten times higher gas pressures were applied, resulting in increased target densities and thus, higher conversion efficiencies of laser energy into EUV and SXR radiation. Secondly, geometrically reducing the angle between the incoming laser beam and the observed plasma emission minimizes reabsorption of the emitted short wavelength radiation. Combining both methods, the source brilliance is increased by a factor of 5 for nitrogen. Furthermore, a compact EUV focusing system for metrological applications is presented utilizing the optimized plasma source. An energy density of 1 mJ/cm2 at wavelength λ = 13.5 nm in the focal spot of an ellipsoidal mirror is achieved with xenon as the target gas being sufficient for material removal of PMMA samples with an ablation rate of 0.05 nm/pulse.
Mechanistic insights into the SNARE complex disassembly
Authors: Huang Xuan , Sun Shan , Wang Xiaojing , Fan Fenghui , Zhou Qiang , Lu Shan , Cao Yong , Wang Qiu-Wen , Dong Meng-Qiu , Yao Jun , Sui Sen-Fang
Published: April 2019

Near-atomic resolution structure of the 20S complex reveals the mechanism of α-SNAP mediated disassembly of the SNARE complex.
Population Pharmacokinetic Modeling of VL-2397, a Novel Systemic Antifungal Agent: Analysis of a Single- and Multiple-Ascending-Dose Study in Healthy Subjects
Authors: Kovanda Laura L. , Sullivan Sean M. , Smith Larry R. , Desai Amit V. , Bonate Pete L. , Hope William W.
Published: April 2019

VL-2397, a novel, systemic antifungal agent, has potent
in vitro
and
in vivo
fungicidal activity against
Aspergillus
species. Plasma concentrations from a phase 1 study were used to construct a population pharmacokinetic (PPK) model for VL-2397.
Impact of FiuA Outer Membrane Receptor Polymorphism on the Resistance of
Pseudomonas aeruginosa
toward Peptidoglycan Lipid II-Targeting PaeM Pyocins
Authors: Latino Libera , Patin Delphine , Chérier Dimitri , Touzé Thierry , Pourcel Christine , Barreteau Hélène , Mengin-Lecreulx Dominique
Published: April 2019

Bacterial antibiotic resistance constitutes a threat to human health, imposing the need for identification of new targets and development of new strategies to fight multiresistant pathogens. Bacteriocins and other weapons that bacteria have themselves developed to kill competitors are therefore of great interest and a valuable source of inspiration for us. Attention was paid here to two variants of a colicin M homolog (PaeM) produced by certain strains of
P. aeruginosa
that inhibit the growth of their congeners by blocking cell wall peptidoglycan synthesis. Molecular determinants allowing recognition of these pyocins by the outer membrane receptor FiuA were identified, and a receptor polymorphism affecting the susceptibility of
P. aeruginosa
clinical strains was highlighted, providing new insights into the potential use of these pyocins as an alternative to antibiotics.
Complete Genome Sequence of Vibrio anguillarum Nontailed Bacteriophage NO16
Authors: Kalatzis Panos G. , Carstens Alexander B. , Katharios Pantelis , Castillo Daniel , Hansen Lars H. , Middelboe Mathias
Published: April 2019

A rare nontailed virus designated NO16 was isolated against
Vibrio
anguillarum
, a major aquaculture pathogen for both fish and shellfish. Here, we announce the 10,594-bp genome sequence of
Vibrio
phage NO16 with a 23-gene content.
Whole-Genome Sequencing of Nontyphoidal Salmonella enterica Isolates Obtained from Various Meat Types in Ghana
Authors: Tay Moon Y. F. , Adzitey Frederick , Sultan Stella Amelia , Tati Joseph Makija , Seow Kelyn L. G. , Schlundt Joergen
Published: April 2019

Here, we report the draft genome sequences of 16 nontyphoidal
Salmonella enterica
isolates obtained from locally produced meats in Tamale, Ghana, which are commonly consumed by most natives as an important protein source. The draft genomes will help provide a molecular snapshot of
Salmonella enterica
isolates found in these retail meats in Tamale.
Draft Genome Sequence of Broad-Spectrum Antibiotic-Producing Marine
Verrucosispora
sp. Strain FIM060022
Authors: Zhao Wei , Xie Yang , Lin Ru , Fang Zhi-kai , Sun Fei , Jiang Hong
Published: April 2019

Verrucosispora
sp. strain FIM060022 shows multiple biological activities and produces polytype structure compounds, including abyssomicins, proximicin A, lumichrome, denosine, and desferrioxamine-like compounds.
Complete Genome Sequence of an Ictalurid Herpesvirus 1 Strain Isolated from Blue Catfish (Ictalurus furcatus)
Authors: Subramaniam Kuttichantran , Venugopalan Arun , Davison Andrew J. , Griffin Matt J. , Ford Lorelei , Waltzek Thomas B. , Hanson Larry
Published: April 2019

The complete genome sequence of an alloherpesvirus isolated from blue catfish (
Ictalurus furcatus
) is reported. Genomic analyses revealed that this virus is a distinct strain of ictalurid herpesvirus 1, the first strain of which was isolated previously from a channel catfish (
Ictalurus punctatus
).
Complete Genome Sequence of
Tomato Leaf Curl New Delhi Virus
from Luffa in Indonesia
Authors: Wilisiani Fariha , Neriya Yutaro , Tagami Mai , Kaneko Misaki , Hartono Sedyo , Nishigawa Hisashi , Natsuaki Tomohide
Published: April 2019

This is the first report of a begomovirus infecting luffa in Indonesia. The genome of this virus shares a close identity with that of
Tomato leaf curl New Delhi virus
(ToLCNDV).
Integrating next-generation sequencing to endoscopic retrograde cholangiopancreatography (ERCP)-obtained biliary specimens improves the detection and management of patients with malignant bile duct strictures
Authors: Singhi Aatur D , Nikiforova Marina N , Chennat Jennifer , Papachristou Georgios I , Khalid Asif , Rabinovitz Mordechai , Das Rohit , Sarkaria Savreet , Ayasso M Samir , Wald Abigail I , Monaco Sara E , Nalesnik Michael , Ohori N Paul , Geller David , Tsung Allan , Zureikat Amer H , Zeh Herbert , Marsh J Wallis , Hogg Melissa , Lee Kenneth , Bartlett David L , Pingpank James F , Humar Abhinav , Bahary Nathan , Dasyam Anil K , Brand Randall , Fasanella Kenneth E , McGrath Kevin , Slivka Adam
Published: April 2019

Objective

Despite improvements in imaging, serum CA19-9 and pathological evaluation, differentiating between benign and malignant bile duct strictures remains a diagnostic conundrum. Recent developments in next-generation sequencing (NGS) have opened new opportunities for early detection and management of cancers but, to date, have not been rigorously applied to biliary specimens.

Design

We prospectively evaluated a 28-gene NGS panel (BiliSeq) using endoscopic retrograde cholangiopancreatography-obtained biliary specimens from patients with bile duct strictures. The diagnostic performance of serum CA19-9, pathological evaluation and BiliSeq was assessed on 252 patients (57 trainings and 195 validations) with 346 biliary specimens.

Results

The sensitivity and specificity of BiliSeq for malignant strictures was 73% and 100%, respectively. In comparison, an elevated serum CA19-9 and pathological evaluation had sensitivities of 76% and 48%, and specificities of 69% and 99%, respectively. The combination of BiliSeq and pathological evaluation increased the sensitivity to 83% and maintained a specificity of 99%. BiliSeq improved the sensitivity of pathological evaluation for malignancy from 35% to 77% for biliary brushings and from 52% to 83% for biliary biopsies. Among patients with primary sclerosing cholangitis (PSC), BiliSeq had an 83% sensitivity as compared with pathological evaluation with an 8% sensitivity. Therapeutically relevant genomic alterations were identified in 20 (8%) patients. Two patients withERBB2-amplified cholangiocarcinoma received a trastuzumab-based regimen and had measurable clinicoradiographic response.

Conclusions

The combination of BiliSeq and pathological evaluation of biliary specimens increased the detection of malignant strictures, particularly in patients with PSC. Additionally, BiliSeq identified alterations that may stratify patients for specific anticancer therapies.