bluuebunny/crossref_metadata_2025 huggingface dataset:
Crohn's Disease Obstructions
Authors: Ford Molly M.
Published: July 2021

Obstruction from stricturing Crohn's disease remains one of the most common reasons for intervention. Acute inflammation is often responsive to medications, but chronic fibrosis is unlikely to respond and will generally go on to require additional treatment. Newer methods, such as endoscopic balloon dilation, are gaining grounds in strictures that are amenable, but with high recurrence and strictures that may not be endoscopically accessible, surgery still plays a key role in the treatment of obstructing Crohn's disease.
Postcolonoscopy Colorectal Cancer: An Overview and Future Directions
Authors: Saikaly Elias , Saad Melissa Kyriakos
Published: July 2021

Over the past decade, there has been a great interest in postcolonoscopy colorectal cancer (PCCRC). Its etiology is complex and multifactorial. Monitoring for PCCRC is even more complex. The strategies to decrease the incidence of PCCRC start by defining the problem, identifying the factors contributing to its development, followed by an attempt to define methods to decrease its incidence. We believe that the quality of the colonoscopy and the endoscopist's expertise are the key factors in decreasing the incidence of PCCRC.
Electrical Status Epilepticus during Sleep and Evaluating the Electroencephalogram
Authors: Drees Michael , Kulkarni Neil , Vidaurre Jorge
Published: July 2021

Electrical status epilepticus during sleep (ESES) is an age-related, self-limited epileptic encephalopathy characterized by heterogeneous clinical manifestations and a specific electroencephalographic pattern of continuous spikes and waves during slow sleep. The etiology of ESES is not completely clear, although structural brain lesions, abnormal immunological markers, and genetic mutations have been associated with the syndrome. ESES was first described in 1971 and since then, the diagnostic criteria have changed multiple times. Additionally, inconsistency between authors in how to record and evaluate the electroencephalogram also leads to variability between studies. These inconsistencies hamper objectivity, comparison, and generalization. Because of this, one of the first priorities of physicians treating this condition should be defining the parameters of this disease so that cooperative building can occur.
Hepaticocystic Duct in an Era of Laparoscopic Cholecystectomy
Authors: Gandhi Jignesh A. , Shinde Pravin , Chaudhari Sadashiv N. , Banker Amay
Published: July 2021

The biliary tract is notorious for its variable anatomy. A persistent hepaticocystic duct with agenesis of common bile duct is a rare biliary anomaly that creates a diagnostic dilemma and can add to the operative difficulties. It is important to diagnose this anomaly preoperatively since the gallbladder forms an integral part of bilioenteric continuity and an inadvertent cholecystectomy can lead to a surgical catastrophe. If diagnosed, surgeons can plan definitive treatment in the form of biliary diversion. We present a case of a 22-year-old man, who presented to us with obstructive jaundice and cholangitis. The biliary system was decompressed initially with a percutaneous transhepatic biliary drainage and an endoscopic retrograde cholangiogram established the diagnosis of a type IV hepaticocystic duct preoperatively in our case. Since diagnosis was made prior to operative intervention, we were able to perform a cholecystojejunostomy to maintain biliary continuity. The patient was discharged with an uneventful postoperative course. To our knowledge, this is the first report of such a variation being diagnosed preoperatively. We are also presenting a brief review of literature about persistent hepaticocystic ducts and the embryological basis of their origin.
Left-Sided Bochdalek's Hernia in a Young Adult: A Case Report and Literature Review
Authors: Portelli Mark , Bugeja Mark , Cini Charles
Published: July 2021

Purpose Bochdalek's hernia is a type of congenital diaphragmatic hernia occurring secondary to a defect in the posterior attachment of diaphragm. This condition commonly presents with respiratory insufficiency in infants. To date, there are less than 100 cases of Bochdalek's hernia presenting in adults published in the literature. The mainstay treatment of Bochdalek's hernia involves reduction of hernial contents back into the peritoneal cavity with a tensionless graft repair closing the diaphragmatic defect.

Case Presentation We present an atypical case of the Bochdalek hernia presenting in a previously healthy 16-year-old male who presented to the Accident and Emergency department with a 2-day history of dysphagia and loss of breath. The Bochdalek hernia was confirmed on computed tomography (CT) imaging and the patient underwent surgical repair with Gore-Tex mesh.

Conclusion The report shows a rare case of the Bochdalek hernia in a young adult, successfully managed with a laparotomy.
Screening for Inherited Metabolic Disorders by Tandem Mass Spectrometry May Miss L-2 Hydroxy Glutaric Aciduria: A Report of Two Cases
Authors: Baskar Dipti , Nashi Saraswati , P. Srijithesh Rajendran , Arunachal Gautham , Christopher Rita , Kulkarni Girish B. , Alladi Survarna
Published: July 2021

L-2 hydroxy glutaric aciduria (L-2HGA) is an autosomal recessive neurometabolic disorder. It is characterized by a variety of clinical features and typical radiological features which aids in diagnosis. We report two cases that presented with unexplained intellectual impairment and seizures. Magnetic resonance imaging (MRI) brain showed characteristic features of L-2HGA. Tandem mass spectrometry was negative in both cases. Genetic analysis was done based on typical imaging features which confirmed the diagnosis of L-2HGA. For patients with unexplained developmental delay and typical MRI features, a high degree of suspicion is necessary to confirm the diagnosis with targeted genetic analysis.
Why Is the Electronic Health Record So Challenging for Research and Clinical Care?
Authors: Holmes John H. , Beinlich James , Boland Mary R. , Bowles Kathryn H. , Chen Yong , Cook Tessa S. , Demiris George , Draugelis Michael , Fluharty Laura , Gabriel Peter E. , Grundmeier Robert , Hanson C. William , Herman Daniel S. , Himes Blanca E. , Hubbard Rebecca A. , Kahn Charles E. , Kim Dokyoon , Koppel Ross , Long Qi , Mirkovic Nebojsa , Morris Jeffrey S. , Mowery Danielle L. , Ritchie Marylyn D. , Urbanowicz Ryan , Moore Jason H.
Published: July 2021

Background The electronic health record (EHR) has become increasingly ubiquitous. At the same time, health professionals have been turning to this resource for access to data that is needed for the delivery of health care and for clinical research. There is little doubt that the EHR has made both of these functions easier than earlier days when we relied on paper-based clinical records. Coupled with modern database and data warehouse systems, high-speed networks, and the ability to share clinical data with others are large number of challenges that arguably limit the optimal use of the EHR

Objectives Our goal was to provide an exhaustive reference for those who use the EHR in clinical and research contexts, but also for health information systems professionals as they design, implement, and maintain EHR systems.

Methods This study includes a panel of 24 biomedical informatics researchers, information technology professionals, and clinicians, all of whom have extensive experience in design, implementation, and maintenance of EHR systems, or in using the EHR as clinicians or researchers. All members of the panel are affiliated with Penn Medicine at the University of Pennsylvania and have experience with a variety of different EHR platforms and systems and how they have evolved over time.

Results Each of the authors has shared their knowledge and experience in using the EHR in a suite of 20 short essays, each representing a specific challenge and classified according to a functional hierarchy of interlocking facets such as usability and usefulness, data quality, standards, governance, data integration, clinical care, and clinical research.

Conclusion We provide here a set of perspectives on the challenges posed by the EHR to clinical and research users.
Effectiveness of the flipped classroom model on students’ self-reported motivation and learning during the COVID-19 pandemic
Authors: Campillo-Ferrer José María , Miralles-Martínez Pedro
Published: July 2021

This study investigates the effects of the flipped classroom on Education students’ perceptions of their learning and motivation during the current pandemic. The sample consisted of 179 student teachers from the Faculty of Education of the University of Murcia in the academic year 2020–2021, in which the flipped classroom model was implemented. Identical surveys were administered and examined through both descriptive statistics and non-parametric tests. Statistically significant differences were found between pre-tests and post-tests with experienced students scoring higher on average in the latter. Most students had a positive perception about the flipped classroom, noting the advantage of practical in-class activities, as well as increased self-autonomy in learning.
Investigation of the wake-up process and time-dependent imprint of Hf0.5Zr0.5O2 film through the direct piezoelectric response
Authors: Takada Kenshi , Murase Mikio , Migita Shinji , Morita Yukinori , Ota Hiroyuki , Fujimura Norifumi , Yoshimura Takeshi
Published: July 2021

Ferroelectric HfO2-based thin films, which have been attracting a great deal attention because of their potential use in various applications, are known for their unique properties, such as a large time-dependent imprint and wake-up effect, which differentiate them from conventional ferroelectric materials. In this study, direct piezoelectric measurement was employed to investigate the state of polarization during the retention and wake-up process without applying an electric field. The polarization-electric field hysteresis loop of a sputtered Hf0.5Zr0.5O2 (HZO) film with a thickness of 10 nm showed a time-dependent imprint at room temperature during polarization retention, and the internal electric field that generated the imprint gradually increased from 0.05 to 0.6 MV/cm. While a space charge density of more than 1 μC/cm2 is required to form such an internal electric field, it was found that the magnitude of the direct piezoelectric response did not change at all during polarization retention. On the other hand, both the remanent polarization and direct piezoelectric response increased during the wake-up process. Based on the difference in the variation over time of these two characteristics, we concluded that the non-ferroelectric layer exists at the interface between the HZO film and TaN electrode and gradually transitions to ferroelectric phases through the electric field cycle.
High-performance n-type transistors based on CVD-grown large-domain trilayer WSe2
Authors: Wang Xin , Shi Xinhang , Gu Chengru , Guo Qi , Liu Honggang , Li Xuefei , Wu Yanqing
Published: July 2021

Atomically thin layered tungsten diselenide (WSe2) has attracted tremendous research attention for its potential applications in next-generation electronics. This article reports the synthesis method of high-quality monolayer to trilayer WSe2 by molten-salt-assisted chemical vapor deposition. With the optimization of different types of molten salts and depths of corundum boat, large trilayer WSe2 films can be grown with domain size up to 80 µm for the first time. A systematic study of the electrical properties of the n-type field-effect transistor has been carried out based on WSe2 with the above three different layer thicknesses. The trilayer WSe2 devices exhibit higher drive current, mobility, on/off ratio, and lower contact resistance than both bilayer and monolayer counterparts. Moreover, short channel transistors using the trilayer WSe2 with a channel length of 230 nm have been fabricated, exhibiting an excellent on/off ratio up to 108 and a high current density of 187 µA/μm. This facile synthesis of high-quality large-area multilayer WSe2 provides a pathway for future high-performance two-dimensional electronic devices.
Chemo-mechanical study of dislocation mediated ion diffusion in lithium-ion battery materials
Authors: Reimuth Christoph , Lin Binbin , Yang Yangyiwei , Stein Peter , Zhou Xiandong , Xu Bai-Xiang
Published: July 2021

A mechanically coupled diffusion model combined with finite element formulation is developed to study the influence of dislocations on ion diffusion in lithium-ion batteries. The dislocation is modeled by the regularized eigenstrain based on a non-singular continuum dislocation theory. The model is validated with the analytical solution of the stress field of edge dislocations and the solution for the stress-dependent equilibrium concentration around the dislocation. Simulation results on LiMn2O4 demonstrate strong ion enrichment and depletion on the tensile and compressive sides of an edge dislocation, respectively. A stronger influence of the edge dislocation on diffusion is found at a lower state-of-charge, which verifies the experimental observation reported in the literature. The diffusion-induced stress compensates partially the stress field of the edge dislocation and is ascertained to have a state-of-charge dependency. The existence of dislocation does not introduce obvious mobility anisotropy in the bulk material but it results in local mobility heterogeneity around the dislocation. A three-dimensional simulation of the diffusion along the edge dislocation line reveals that the pipe diffusion can be initiated or accelerated on the tensile side of the edge dislocation.
Positive correlation between interlayer exchange coupling and the driving current of domain wall motion in a synthetic antiferromagnet
Authors: Hung Yu Min , Shiota Yoichi , Yamada Shogo , Ohta Minoru , Shibata Tatsuo , Sasaki Tomoyuki , Hisatomi Ryusuke , Moriyama Takahiro , Ono Teruo
Published: July 2021

The interlayer exchange coupling (Jex) in a perpendicularly magnetized synthetic antiferromagnet (p-SAF) is an important factor in the properties of domain wall (DW) motion driven by spin–orbit torque (SOT). In this study, we investigate experimentally and numerically how Jex affects the critical current density (Jc) of DW motion in an SOT-driven p-SAF. We also study how Jex affects the DW deflection angle (θDW), which is defined as the relative angle between the initial magnetization direction in the DW and the final one upon the injection of spin current. Positive correlation is found between Jex and Jc, which can be attributed to the suppression of θDW. Our results reveal how Jex affects the driving current of DW motion in an SOT-driven p-SAF.
Nonexistence of ground state solutions for generalized quasilinear Schrödinger equations via dual approach
Authors: Jing Yongtao , Liu Haidong
Published: July 2021

We study quasilinear Schrödinger equations of the form −divA(u)∇u+12A′(u)|∇u|2+V(x)u=h(u), x∈RN, where N≥3,A∈C1(R,R) is a positive function, V∈C2(RN,R) is a given potential, and h∈C1(R,R) is a suitable nonlinearity. Under some mild assumptions, we establish the nonexistence of ground state solutions for such equations by using the dual variational approach and Pohožaev manifold technique.
Discrete SQG models with two boundaries and baroclinic instability of jet flows
Authors: Kalashnik M. V. , Chkhetiani O. G. , Kurgansky M. V.
Published: July 2021

In this paper, new vertically discrete versions of the surface quasigeostrophic (SQG) model with two boundaries are formulated. For any number of partition levels, the equations of the discrete model are written in the form of conservation laws for two Lagrangian invariants, which have the meaning of buoyancy distributions at the horizontal boundaries of the fluid layer. The values of the invariants are expressed in terms of the values of the stream function at two internal levels and contain higher order elliptic operators. The use of discrete models greatly simplifies the solution of problems of the linear theory of hydrodynamic stability and provides high accuracy even with a small number of vertical discrete levels. Using the two-level version of the SQG model, which is similar to the classical two–layer Phillips model, we investigated the linear stability of jet flows induced by piecewise constant boundary distributions of buoyancy. For these flows, analytical expressions for the growth rate of perturbations have been obtained and it is shown that the most unstable perturbation has a wavelength of the order of the Rossby baroclinic radius of deformation. Flows with vertical shear induced by smooth and slowly varying boundary buoyancy distributions are also considered. The instability of these flows is found to be absolute, that is, independent of the velocity profile horizontal structure.
Numerical simulation on double diffusion natural convection of a power-law nanofluid within double wavy cavity
Authors: Jain Sapna , Nishad Surabhi , Bhargava Rama
Published: July 2021

In the present paper, the effect of double diffusion natural convection fluid flow inside the double wavy enclosure using the mesh-free method is investigated. The enclosure is filled with nanofluid whose base fluid is non-Newtonian. The results are obtained for the variation in Brownian motion parameter (0.2–0.8), buoyancy ratio parameter (0.2–1), power-law index (0.2–1), thermophoresis parameter (0.2–0.8), Rayleigh number (103–105), and Lewis number (1–5) on mass and heat transfer. It is explored that the mass and heat transfer rate increases with increase in the Rayleigh number and buoyancy ratio. Heat transfer rate decreases with increase in the thermophoresis parameter, Lewis number, Brownian motion, and power-law index, whereas mass transfer rate increases. Such type of enclosure has direct application in heat exchanger devices, the double-wall thermal insulation system, and microelectronic devices. Parallel implementation with the hybrid [EFGM (element free Galerkin method)/FEM (finite element method)] method has been used for the reduction of the running cost to ensure efficiency, which is the novel contribution of the author.
Influence of loading rate on the infrared radiation of PMMA
Authors: Zhang Mingyuan , Chen Lu , Li Dejian , Rao Yuanhao , Li Yingjun
Published: July 2021

Infrared thermography has widely been used in observing and recording failure processes. The loading rate is a critical parameter that influences the infrared radiation (IR) in the mechanical experiment. However, little work has been done regarding its influence on infrared radiation. In order to conduct an in-depth study on the influence of loading rates on IR, a series of three-point bending experiments were conducted on PMMA samples for the IR test. Then, the influence was explained through a physical model derived from the first law of thermodynamics. The experimental results showed that under a fixed loading rate, the change rate of the IR emission was constant, and the relationship between the IR emission and loading time exhibited a linear trend. The variation between the change rate of IR emission and the loading rate can be expressed by the exponential function. The insights gained from this study will be of assistance to obverse the loading processes by infrared thermography.
A stereo photogrammetry system for model position and attitude measurement in hypersonic wind tunnel testing
Authors: Zhang Mingkai , Liang Jin , Chen Lei , Tang Zhengzong , Zong Yulong
Published: July 2021

In this paper, a measurement system based on stereo photogrammetry is proposed for position and attitude measurements of test models in hypersonic wind tunnel testing. Several adaptations were made to an existing stereo photogrammetry system to promote its routine use as a primary wind tunnel measurement system. First, cameras were installed in the wind tunnel test section to decrease the measurement distance and increase the base length, which helped improve the measurement accuracy. To deal with camera vibration caused by the freestream, a camera orientation method is proposed to estimate the exterior parameters of each frame relative to the tunnel coordinate system. Second, a scheme to determine the model coordinate system is proposed, which does not require placement of the targets at known locations of the model. Third, to solve the recognition problem of motion-blurred target images, a network was adopted for stereo deblurring and a stereo blur dataset simulating the wind tunnel test environment was generated for network training. To develop the novel stereo photogrammetry system, experiments were conducted in both the laboratory and a hypersonic wind tunnel at the China Aerodynamics Research and Development Center. The experimental results suggest that the proposed measurement system is practicable for position and attitude measurements of test models in hypersonic wind tunnel testing.
Quantifying COVID-19 importation risk in a dynamic network of domestic cities and international countries
Authors: Han Xiaoyi , Xu Yilan , Fan Linlin , Huang Yi , Xu Minhong , Gao Song
Published: July 2021

Significance

In the COVID-19 pandemic, countries need to manage both the domestic spread and the spread of the virus from foreign countries, with their relative urgency varying over time. Based on a dynamic network of cities and countries connected by travel flows, we demonstrate that imported cases would have a limited effect on a country’s confirmed cases if domestic transmission mechanisms had been muted or significantly weakened. However, uncontrolled domestic disease transmission can fuel the spread from abroad to domestic. We show that domestic transmissibility controls should be prioritized over travel restrictions and international transmissibility controls to limit the virus spread from abroad. Our research sheds light on the proper timing to reopen borders under different domestic disease control scenarios.
Termite gas emissions select for hydrogenotrophic microbial communities in termite mounds
Authors: Chiri Eleonora , Nauer Philipp A. , Lappan Rachael , Jirapanjawat Thanavit , Waite David W. , Handley Kim M. , Hugenholtz Philip , Cook Perran L. M. , Arndt Stefan K. , Greening Chris
Published: July 2021

Significance

Termites are textbook examples of the “extended phenotype” given their ability to construct complex mounds and regulate environments. Here, we show that termites also control microbial composition and biogeochemical cycling in their mounds through their emissions of hydrogen. These emissions drive remarkable enrichments of mound bacteria that use hydrogen to drive aerobic respiration and sometimes carbon fixation (i.e., lithoautotrophs). Such mound communities efficiently consume all termite-produced hydrogen and even mediate atmospheric uptake, while termite-produced methane escapes to the atmosphere. This provides further evidence that hydrogen is a major substrate for aerobic bacteria and that the terrestrial hydrogen sink is highly responsive to elevated emissions.
Engaging with customer’s emotions
Authors: Pérez Blanco María , Izquierdo Marlén
Published: July 2021

Informational-persuasive discourse may be encoded in promotional strategies through which a given product is described in a positive way to persuade potential customers. For this, evaluation may appeal to reason or may tickle emotions (Cook, 2001). This study compares the way in which advertising texts for herbal tea engage with customers’ emotions in English and in Spanish. We examined the strategies of ‘enjoying the experience’ and ‘aesthetic appeal’ from an Appraisal Theory approach (Martin and White, 2005). We categorised these according to the attitude sub-systems of ‘affect’, ‘appreciation’, and ‘judgement’, determined how explicit the evaluation was, and identified gradable resources. Results show that English texts display more ‘affect’-like resources that can awaken a desire in the customer. By contrast, in the Spanish sample ‘appreciation’ resources that evaluate the composition of the product play a greater role. ‘Enjoying the experience’ seems to engage with the customers’ emotions more overtly than ‘aesthetic appeal’.
Physical Therapists’ Attitudes are Associated with their Confidence in and the Frequency with which they Engage in Prescription Opioid Medication Misuse Management Practices with their Patients. A Cross–Sectional Study
Authors: Magel John (Jake) , Cochran Gerald , West Nancy , Fritz Julie M. , Bishop Mark D. , Gordon Adam J.
Published: July 2021

Background: In the US, prescription opioid medication misuse (POMM) necessitates engagement of physical therapists (PTs). We (1) evaluated the attitudes of (PT) related to their management of patients with POMM and (2) examined the association between these attitudes and PTs confidence in POMM–related management abilities and the frequency with which they engaged in POMM–related management practices. Methods: We conducted a national survey of PTs that included a modified Drug and Drug Problems Perception Questionnaire (DDPPQ). Confidence in POMM–related abilities and the frequency of engaging in POMM–related management practices were measured. Logistic regression evaluated the association between the DDPPQ subscales (role adequacy, role legitimacy, role self–esteem, role support, job satisfaction) and confidence and frequency outcomes. Results: The analysis included 402 respondents. Role adequacy and legitimacy subscales were associated with confidence and frequency outcomes ( p<.05), indicating that more favorable role adequacy and legitimacy attitudes are associated with greater odds of having more confidence in POMM–related management abilities and of engaging in more frequent POMM–related management practices. Conclusions: PTs with a greater sense of preparedness to engage in POMM–related management were more likely to report greater confidence in POMM–related management abilities and engage in POMM–related management practices with greater frequency.
Rethinking the procedural in policy instrument ‘Compounds’: a renewable energy policy perspective
Authors: Mukherjee Ishani
Published: July 2021

Contemporary research in the policy sciences places effectiveness as the central goal of policy design. This emphasis permeates both micro-level design considerations for specific policy calibrations, as well as more meso-level policy tool and tool mixes. Effective instrument design, therefore, augments the task of looking at individual tools to considering them as tool ‘compounds’, that comprise of substantive and procedural means interacting through the process of designing tools and subsequent tool calibrations. The academic study of policy tools thus far has proffered several perspectives on how they can individually be distinguished by their different substantive components and categorized based on common governance resources that need to be mobilized to create them. However, it is eventually how well policy tools are able to coordinate the support of common procedural means and how well they are able to align their enactment plans, which determine how effectively they work together as a deliberate toolkit. In line with the growing literature on policy design and multi-component policy means, this paper magnifies policy instrument design as a complex of procedural and substantive means. To illustrate the notion of such design compounds, this paper synopsizes the state of knowledge on the formulation of three classes of energy policies as an illustration of how substantive and procedural components interact during policy instrument design.
Coupled sterol synthesis and transport machineries at ER–endocytic contact sites
Authors: Encinar del Dedo Javier , Fernández-Golbano Isabel María , Pastor Laura , Meler Paula , Ferrer-Orta Cristina , Rebollo Elena , Geli Maria Isabel
Published: July 2021

Sterols are unevenly distributed within cellular membranes. How their biosynthetic and transport machineries are organized to generate heterogeneity is largely unknown. We previously showed that the yeast sterol transporter Osh2 is recruited to endoplasmic reticulum (ER)–endocytic contacts to facilitate actin polymerization. We now find that a subset of sterol biosynthetic enzymes also localizes at these contacts and interacts with Osh2 and the endocytic machinery. Following the sterol dynamics, we show that Osh2 extracts sterols from these subdomains, which we name ERSESs (ER sterol exit sites). Further, we demonstrate that coupling of the sterol synthesis and transport machineries is required for endocytosis in mother cells, but not in daughters, where plasma membrane loading with accessible sterols and endocytosis are linked to secretion.
Purcell radiative rate enhancement of label-free proteins with ultraviolet aluminum plasmonics
Authors: Barulin Aleksandr , Roy Prithu , Claude Jean-Benoît , Wenger Jérôme
Published: July 2021

The vast majority of proteins are intrinsically fluorescent in the ultraviolet, thanks to the emission from their tryptophan and tyrosine amino-acid constituents. However, the protein autofluorescence quantum yields are generally very low due to the prevailing quenching mechanisms by other amino acids inside the protein. This motivates the interest to enhance the radiative emission rate of proteins using nanophotonic structures. Although there have been numerous reports of Purcell effect and local density of optical states control in the visible range using single dipole quantum emitters, the question remains open to apply these concepts in the UV on real proteins containing several tryptophan and tyrosine amino acids arranged in a highly complex manner. Here, we report the first complete characterization of the Purcell effect and radiative rate enhancement for the UV intrinsic fluorescence of label-free β-galactosidase and streptavidin proteins in plasmonic aluminum nanoapertures. We find an excellent agreement with a calibration performed using a high quantum yield UV fluorescent dye. Demonstrating and intensifying the Purcell effect is essential for the applications of UV plasmonics and the label-free detection of single proteins.
Spatio-temporal dynamics of a model for the effect of variable ages at reproduction
Authors: Lou Yijun , Zhang Yuxiang
Published: July 2021

Some species may have totally different ages at successful reproduction (ages at maturity) in population growth. For example, Ixodes ticks, a vector species responsible for many tick-borne diseases, may suspend development and undergo diapause during maturation process, which naturally introduce distinct ages at reproduction. Although the age at reproduction is a key demographic trait that is probably under high selective pressure, it is highly variable and the effect of this variability on spatial establishment and invasion is not well understood. In this study, a spatial mechanistic model, in the form of reaction diffusion equations with nonlocal terms incorporating two different ages at reproduction, is formulated and mathematically analyzed from a dynamical system point of view. Specifically, the persistence of the species in a bounded domain can be predicted by the net reproduction number and the spreading property in an unbounded domain in terms of spreading speed and traveling waves is characterized. Numerical simulations are conducted to further illustrate the impact of ages at reproduction on the net reproduction number and the spreading speed of the species, in particular for various scenarios of fitness tradeoffs of the premature survival and early reproduction.
Warp factor and the gravitational wave spectrum
Authors: Andriot David , Marconnet Paul , Tsimpis Dimitrios
Published: July 2021

A distinct signature of compact extra dimensions would be a Kaluza-Klein tower of gravitational waves. Motivated by this prospect, we compute the corresponding spectrum on a warped toroidal background. We evaluate in particular the impact of the warp factor on the spectrum. To that end, we use the complete warp factor H of standard string compactifications, generated by D-branes and orientifolds, thus connecting to recent works on stringy de Sitter constructions. The problematic region close to an orientifold where H < 0 leads to unphysical tachyonic modes in the spectrum. We develop tools that overcome this difficulty and lead to a tachyon-free spectrum. We show, in particular, that the warp factor can lower the first Kaluza-Klein mass by at least 69%.
Approximations based on density-matrix embedding theory for density-functional theories
Authors: Theophilou Iris , Reinhard Teresa E , Rubio Angel , Ruggenthaler Michael
Published: July 2021

Recently a novel approach to find approximate exchange–correlation functionals in density-functional theory was presented (Mordovina et al 2019 J. Chem. Theory Comput.
15 5209), which relies on approximations to the interacting wave function using density-matrix embedding theory (DMET). This approximate interacting wave function is constructed by using a projection determined by an iterative procedure that makes parts of the reduced density matrix of an auxiliary system the same as the approximate interacting density matrix. If only the diagonal of both systems are connected this leads to an approximation of the interacting-to-non-interacting mapping of the Kohn–Sham approach to density-functional theory. Yet other choices are possible and allow to connect DMET with other density-functional theories such as kinetic-energy density functional theory or reduced density-matrix functional theory. In this work we give a detailed review of the basics of the DMET procedure from a density-functional perspective and show how both approaches can be used to supplement each other. We do not present a specific realization of combining density-functional methods with DMET but rather provide common grounds to facilitate future developments that encompass both approaches. We do so explicitly for the case of a one-dimensional lattice system, as this is the simplest setting where we can apply DMET and the one that was originally presented. Among others we highlight how the mappings of density-functional theories can be used to identify uniquely defined auxiliary systems and projections in DMET and how to construct approximations for different density-functional theories using DMET inspired projections. Such alternative approximation strategies become especially important for density-functional theories that are based on non-linearly coupled observables such as kinetic-energy density-functional theory, where the Kohn–Sham fields are no longer obtainable by functional differentiation of an energy expression, or for reduced density-matrix functional theories, where a straightforward Kohn–Sham construction is not feasible.
A Randomized, Crossover-Controlled Evaluator-Blinded Trial Evaluating Cannula- vs Needle-Assisted Hyaluronic Acid Injections for Infraorbital Deformities
Authors: Nikolis Andreas , Berros Philippe , Enright Kaitlyn M , Cordoba Magdalena , Nguyen Quynh
Published: July 2021

Background

Periorbital deformities can be corrected utilizing hyaluronic acid injections. However, previous studies have not evaluated the effect of utilizing different injection techniques (eg, a needle vs cannula) on efficacy and safety.

Objectives

The authors sought to investigate the efficacy and safety of HA for the correction of periorbital deformities when utilizing either needle or cannula-assisted injections.

Methods

This was a prospective, randomized-controlled (with crossover), evaluator-blinded study. Forty-two patients with a mean age of 44.82 ± 11.62 years were recruited. Patients underwent 2 treatment sessions, spaced 2 weeks apart, and attended 1 follow-up visit at Week 4, following the last treatment. Patients were randomized in a 3:3:1 ratio, whereby 18 patients received injections by needle, 18 received injections by cannula, and 6 were randomized to act as their own control at baseline. Those in the control group were randomized (n = 3) to needle or cannula injections at Week 4 and proceeded with the same visit schedule as those treated at baseline. At Weeks 2 and 4 posttreatment, patient satisfaction was evaluated and information on adverse effects was collected. A blinded reviewer assessed patient imagery utilizing standardized efficacy scales.

Results

Chi-square tests did not reveal any associations between treatment group and efficacy, safety, or patient satisfaction scores (P ≥ 0.05). Adverse effects reported in patient diaries were mild to moderate in nature and expected.

Conclusions

For the treatment of infraorbital deformities, hyaluronic acid injections performed utilizing either a cannula or needle result in similarly high efficacy and safety ratios.

Level of Evidence: 2
A comparison of the efficiency of RNA extraction from extracellular vesicles using the Qiagen RNeasy MinElute versus Enzymax LLC RNA Tini Spin columns and qPCR of miRNA
Authors: Dunlop Rachael Anne , Banack Sandra Anne , Cox Paul Alan
Published: July 2021

One consequence of the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is an interruption to the supply of laboratory consumables, particularly those used for RNA extraction. This category includes column-based RNA extraction kits designed to retain short RNA species (defined as having fewer than 200 nucleotides), from small sample volumes, e.g. exosomes or extracellular vesicles (EVs). Qiagen manufactures several kits for the extraction and enrichment of short RNA species, such as microRNA (miRNA), which contain silica-membrane columns called “RNeasy MinElute Spin Columns.” These kits, which also contain buffers and collection tubes, range in price from USD380 to greater than USD1000 and have been subject to fulfillment delays. Scientists seeking to reduce single-use plastics and costs may wish to order the columns separately; however, Qiagen does not sell the RNeasy MinElute Spin Columns (in reasonable quantities) as an individual item. Thus, we sought an alternative product and found RNA Tini Spin columns from Enzymax LLC. We conducted a systematic comparison of the efficiency of RNA extraction for miRNA quantitative real-time PCR (qPCR) using the Qiagen RNeasy MinElute Spin Columns and Enzymax LLC RNA Tini Spin columns and the Qiagen total RNA extraction protocol that enriches for short RNA species. We compared the efficiency of extraction of five spike-in control miRNAs, six sample signal miRNAs, and nine low- to medium-abundance miRNAs by qPCR. The RNA was extracted from EV preparations purified from human plasma using CD81 immunoprecipitation. We report no statistically significant differences in extraction efficiencies between the two columns for any of the miRNAs examined. Therefore, we conclude that the Enzymax RNA Tini Spin columns are adequate substitutes for the Qiagen RNeasy MinElute Spin Columns for short RNA species enrichment and downstream qPCR from EVs in the miRNAs we examined.
Live integration of comprehensive cardiac CT for myocardial fibrosis and coronary anatomy with electroanatomical mapping in patients with refractory ventricular tachycardia: a pilot study
Authors: Conte E , Carbucicchio C , Catto V , Kochi AN , Mushtaq S , Sattin T , De Iuliis P , Pontone G , Pepi M , Tondo C , Andreini D
Published: July 2021

Funding Acknowledgements

Type of funding sources: None.

Aim of the study was to verify the feasibility and accuracy of live integration of myocardial fibrosis evaluated at CCT with EAM. The present is the first report of live integration of cardiac computed tomography (CCT) data for myocardial fibrosis and coronary anatomy with electroanatomical mapping (EAM).

We prospectively enrolled all patients admitted with a clinical indication to endocardial and epicardial EAM before radiofrequency catheter ablation (RFCA) of refractory ventricular tachycardia (VT) and an absolute contraindication to cardiac magnetic resonance. All patients underwent per protocol CCT for myocardial fibrosis and coronary anatomy evaluation, before RFCA procedures. Sensitivity, specificity, negative predictive value, positive predictive value and diagnostic accuracy were assessed for myocardial fibrosis evaluation with CCT vs EAM on a per segment-basis taking into consideration both any type of fibrosis and ischemic vs non ischemic subtypes. Live integration feasibility of CCT vs EAM was evaluated for every patients.

Live integration feasibility and diagnostic performance of CCT vs EAM for myocardial fibrosis identification was evaluated for every patients. EAM adverse events were recorded as well.

In all patients CCT data were successfully integrated with EAM during RFCA procedure. All patients had myocardial fibrosis correctly identified at CCT vs EAM on a per-patients basis. A diagnostic accuracy of 94.1% for detection of any type of myocardial fibrosis at CCT vs EAM was recorded. No pericardial tamponade and/or pericardial effusion were recorded.

CCT identification of myocardial fibrosis is feasible and accurate vs EAM in a very selected high risk patients with clinical indication to RFCA of VT and contraindication to CMR. CCT images integration during EAM is feasible and enable to provide electrophysiologist useful information regarding myocardial fibrosis and coronary arteries location, possibly avoiding invasive coronary angiography.
Long-term prognosis of zero coronary artery calcium score in symptomatic low to intermediate risk patients
Authors: Kamerman M , Timmer JR , Ottervanger JP , Van Dijk JD , Knollema S , Jager PL , Nasir K , Mouden M
Published: July 2021

Funding Acknowledgements

Type of funding sources: None.

Purpose/background

Absence of coronary artery calcium (CAC) has shown an excellent long-term prognosis with a low number of events in asymptomatic patients. However, long-term prognosis in stable symptomatic patients undergoing SPECT MPI with a zero CAC score remains unknown.

Methods

 We retrospectively analyzed 1600 low- to intermediate risk symptomatic patients referred for clinically indicated cardiac SPECT/CT imaging with a CAC score of zero. Long-term follow-up data were collected for the occurrence of all-cause mortality and major adverse cardiac events (MACE: any revascularization, non-fatal myocardial infarction or cardiac death).

Results

 The mean age was 54.7 ± 11 years and 71% were female. More than half of the patients (51%) had 2 or more traditional risk factors, mainly a positive family history (55%) and/or hypertension (49%).  Overall 12% had perfusion abnormalities, 98% of them were mild. During a mean follow-up of 8.6 ± 1.9 years MACE occurred in 42 patients (0.3% per year) and 85 patients died (0.6% per year). The predominant cause of death was cancer (40%). Cox proportional hazard model revealed that increasing age (HR: 1.05, 95% CI: 1.02-1.09) and current smoking status (HR: 3.58, 95% CI: 1.72-7.37) were independent predictors of MACE.  Pre-test probability (HR: 1.52, 95% CI: 0.82-2.82) and abnormal SPECT result (HR: 1.72, 95% CI: 0.88-3.37) were not associated with an increased risk of MACE.

Conclusion

Overall, stable symptomatic patients with a low-to intermediate risk and a CAC score of 0 have a) low likelihood of abnormal SPECT, and  b) excellent long-term prognosis of 0.3%/year irrespective of baseline pre-test probability and SPECT abnormalities. These findings support notion of CAC as gatekeeper for appropriate patient selection to avoid un-necessary downstream testing.
Routine clinical use of 15O-water cardiac PET: Initial experience with a novel automated solution
Authors: Tolbod LP , Gormsen LC
Published: July 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

 While considered the gold standard for cardiac perfusion imaging and myocardial blood flow quantitation, the use of 15O-water has been largely restricted to research purposes. The practical hurdles associated with the ultra-short half-life of the tracer and the lack of dedicated software have hampered the routine clinical use of 15O-water and novel solutions have been sought to obviate the issues limiting its use. An innovative bedside 15O-water generator designed for simple push button operation and high patient through-put has been developed and recently installed at our institution and utilized clinically under a magistral exception. The system also includes an infusion device and a dedicated display and analysis software. We report the initial experience utilizing such solution for routine clinical use of 15O-water.

Methods

 The first routine human myocardial perfusion imaging tests with PET 15O-water were conducted at our institution in December 2020. The 15O-water was produced and infused using the bed-side water generator. The activity per scan was 400 MBq in 20-35 mL of saline infused at a speed of 1-2 mL/s. Each exam consisted of a low-dose CT followed by a 4 min rest dynamic PET scan and, finally, a 4 min stress dynamic PET scan. Pharmacological stress was induced using a 6 min infusion of adenosine (0.14 mg/kg/min) starting 2 min prior to the stress PET scan. The exam time (time from initiation of the low dose CT to the end of the stress PET scan) was monitored. Images were analyzed using the dedicated software.

Results

 Since its implementation on December 7, 2020 and as of February 23, 2021, all patients referred to the hospital for cardiac perfusion imaging have been studied with this approach. Over this period of time, a total of 295 patients have been imaged with an average of 6 patients per day (a total of 50 scan days, 3-8 patients per day). The median total exam time was 22 min (85% of the exams were within 25 min and 95% below 30 min).

Conclusion

  Routine clinical use of 15O-water PET has been practically implemented utilizing a novel bedside generator and infusion solution. The system has proven to be reliable and efficient. This initial experience suggests that a very high patient throughput is achievable with improved resource utilization. The expected high diagnostic accuracy of the test is being evaluated with the dedicated imaging software.