bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance evaluation of free space optical link by incorporating the device parameters of quantum cascade laser based transmitter
Authors: Ashok P , Madhan M Ganesh , Natraj N A
Published: February 2021

This article investigates the performance of a free space optical (FSO) communication link by incorporating the device parameters that influence the optical output power of the quantum cascade laser (QCL). The transmitter side of the FSO link consists of gain-switched QCL operating at 9 µm. Short optical pulses possessing minimum full width half maximum (FWHM) and peak power as a result of ON-OFF keying are transmitted into the channel. The pulses are attenuated by medium bound losses and reach the receiver which employs quantum well infrared photodetector operating in the same wavelength. Average signal-to-noise ratio (SNRavg), bit error rate (BER) and Channel Capacity are computed for the FSO link for all the variations in the device parameters namely optical confinement factor (Γ), spontaneous emission factor (β) and mirror reflectivity (R). The combination of device parameters that gives the best link performance is assessed. From the analysis it is observed that, under minimum FWHM condition, QCL with Γ = 0.32 provides the best average SNR of 4.04 dB, lowest BER of 13.02 × 10−2 and maximum capacity of 1.82 bps Hz−1. When peak power is the constraint, QCL with mirror reflectivity of Γ = 0.45 provides the best average SNR of 24.78 dB, lowest BER of 7.75 × 10−35 and a peak capacity of 8.24 bps Hz−1.
Optical properties of ZnO:SiO2:Tb3+films: the effect of DNA
Authors: Boruleva E A , Chudinova G K , Hayrullina I A , Nagovitsyn I A , Khoroshilov A V , Lobanov A V
Published: February 2021

Thin films of zinc oxide and those doped with terbium (at concentrations of 0.1–5.0 mol%) were synthesized on glass substrates using the sol–gel method. The UV–Vis transmission spectra showed that transparency increases from 60% to 86% with an increase of Tb content. All terbium-doped samples exhibit a rise in Eg from 3.37 eV for zinc oxide to 3.827 eV for doped films. The photoluminescence (PL) of zinc oxide doped with terbium in the UV (260 nm) region and the fluorescence of terbium in the visible region (330 nm) were studied. The intensity of green luminescence with an increase in the amount of terbium increases by an average of 6%. The yield of green fluorescence relative to PL also goes up with an increase in the concentration of terbium concentration of terbium from 5% to 7.4%. DNA deposited on the surface of the plate extinguishes PL by an average of 5.5% and has a weak effect (<3%) on terbium fluorescence in the visible region. SEM images without DNA consist of spherical structures—0.5–2.0μm in diameter, assembled in the form of pentagons. The presence of DNA on the surface is expressed as ‘stars’ of white color of regular and irregular shapes, located on the surface inside these pentagons.
First-principles calculations of F-, Cl-, and N-related defects of amorphous SiO2 and their impacts on carrier trapping and proton release*
Authors: Gao Xin , Yue Yunliang , Liu Yang , Zuo Xu
Published: February 2021

The first-principles calculations based on density functional theory are performed to study F-, Cl-, and N-related defects of amorphous SiO2 (a-SiO2) and their impacts on carrier trapping and proton release. The possible geometric configurations of the impurity-related defects, the formation energies, the hole or electron trapping of the neutral defects, and the mechanisms to suppress proton diffusion by doping N are investigated. It is demonstrated by the calculations that the impurity atoms can interact with the oxygen vacancies and result in impurity-related defects. The reactions can be utilized to saturate oxygen vacancies that will cause ionization damage to the semiconducting devices. Moreover, the calculated formation energy indicates that the F- or Cl-related oxygen vacancy defect is a deep hole trap, which can trap holes and prevent them from diffusing to the a-SiO2/Si interface. However, three N-related defects, namely N(2)o–H, N(2)o=O, and N(3)o–V
o, tend to act as shallow hole traps to facilitate hole transportation during device operation. The N(2)o and N(3)o configurations can be negatively charged as deep electron traps during the oxide charge buildup after ionization radiation. In addition, the nudged elastic band (NEB) calculations show that four N-related defects, namely N(2)o, N(2)o–H, N(2)o=O, and N(3)o are capable of capturing protons and preventing them from diffusing to and de-passivating the interface. This research reveals the fundamental properties of the F-, Cl-, and N-related defects in amorphous silica and the details of the reactions of the carrier trapping and proton release. The findings help to understand the microscopic mechanisms that alleviate ionization damage of semiconducting devices by doping a-SiO2.
Nucleon-pair approximation with uncoupled representation *
Authors: Lei Y. , Lu Y. , Zhao Y. M.
Published: February 2021

In this paper, we propose an approach to nucleon-pair approximation (NPA) with m-scheme bases, in which the collective nucleon pairs are represented in terms of antisymmetric matrices, and commutations between nucleon pairs are given using a matrix multiplication that avoids angular-momentum couplings and recouplings. Therefore the present approach significantly simplifies the NPA computation. Furthermore, it is formulated on the same footing with and without isospin.
Development of plasma technology for metal powders used in additive technologies
Authors: Kadyrov A A , Yushin B A , Frolov V Ya
Published: February 2021

The article describes the main characteristics of plasma technology designed for the production of metal powders, such as voltage, current, plasma-forming gas flow rate, plasma flow temperature. Based on experimental data and theoretical calculations, mathematical models are constructed to refine the defining characteristics, as well as to visualize the process. The mathematical model contains a spray chamber, an electrode rotation mechanism, a gas mixture supply unit, a plasma heating source, and a water cooling system for the chamber walls. The method of a rotating electrode with plasma heating (PREP) was used.
Design and modelling of a universal CNC machine
Authors: Rastvorova I I , Klyucherev N A
Published: February 2021

This paper proposes a method of designing an affordable, universal Computer Numerically Controlled (CNC) machine for the use by hobbyists and university laboratories. The machine combines the functions of a 3 to 4-axis milling machine and of a 3D printer. We discuss the major factors contributing to manufacturability and dimensional accuracy of the produced parts, and make several suggestions that aim to maximize the cost effectiveness of the machine’s design. A methodology is developed for optimizing the machine’s rigidity and dimensional accuracy by selecting the proper off-the-shelf components. A calculation that follows the proposed method starts when the required level of accuracy and the machining speed is specified; the result of such a calculation is the overall design of the CNC machine, a bill of materials, and the cost estimate. The design can be optimized for cost, weight, or other parameters. The model presently accounts for the forces generated by the cutting action, the acceleration of machine components, and the associated simple bending moments. The future work in this area relates to the improvement of the proposed method and mathematical model to account for the twisting moments, friction, and vibration.
Acoustically induced mass transfer in saturated porous media
Authors: Izmaylova G R
Published: February 2021

The paper provides a physical rationale for acoustic flows to occur in porous saturated media. A formula is derived for calculating the velocities of these flows, assuming that all acoustic energy is converted to create flows in a formation. It is assumed that the velocity of acoustic flows depends on the acoustic intensity and the fluid viscosity that saturates pore spaces. With increased fluid viscosity, acoustic velocity decreases. An experimental framework is presented for the effect of combined acoustic and constant electric fields on the permeability of a saturated porous medium.
Forming small junctions with reduced defectiveness
Authors: Mustafaev G A , Khasanov A I , Mustafaev A G
Published: February 2021

This paper is dedicated to studying possibilities of forming small junctions with reduced defectiveness. As horizontal dimensions of devices in VLSIs diminishes, the task of reducing their vertical dimension becomes more pressing. Due to that, the task of producing small p+n junctions for CMOS structures by means of boron implantation becomes ever more important; the projected path of boron ions is significantly longer than those of n-type conductivity dopants. Using ion implantation for this purpose at low energy is not a good idea, as the depth of junction is largely determined by channeling effects in monocrystalline substrates. Ion implantation in substrate covered with amorphous films of SiO2 or Si3N4 does not remove the phenomenon of channeling completely. Nitrogen and oxygen atoms being trapped in the substrate from the amorphous films may result in degradation of characteristics of produced devices. Besides the channeling effects, the processes of dopant redistribution during annealing may also significantly affect the depth of the junctions.
Research on Intelligent Assembly Modes of Aerospace Products Based on Digital Twin
Authors: Shi Li , Yan Liang , Shuqing Bai , Cuobo Zhuang , Yuanchong Cao
Published: February 2021

Based on the multi-varieties and scalable batch production mixed line assembly of aerospace products, this paper proposes the technical approach and system architecture of an intelligent assembly integration platform which is composed of hardware layer, software layer and application layer from bottom up, so as to construct an intelligent assembly integration application platform based on the digital twin. Hardware layer is composed of the equipment and communication, software layer mainly includes the database and functional modules, and application layer is constructed based on a digital twin model, realizing visual monitoring of the assembly process. This paper establishes an intelligent monitoring mode based on digital twin and an intelligent control mode based on two-layer optimization. At the workshop layer, a digital twin mode of entities is constructed so as to form a plan optimization information, logistics optimization information and quality optimization information, and post control optimized execution information is sent back to the workshop operational layer. At the assemble line layer, real-time information is acquired, equipment monitoring is realized, and optimized information is sent back to the workshop operational layer, achieving control and optimization of assembly lines. This paper reshapes processes under this intelligent assembly mode; and verify its application in aerospace product assembly.
A Sales Prediction Method Based on LSTM with Hyper-Parameter Search
Authors: Dai Yun , Huang Jinghao
Published: February 2021

Sales forecast is a significant topic in business operation, which generally formulated as a time-series regression problem. Although there are many research results in this field, we still face some challenges in real scenes, such as data with high-sparsity, users may have a preference in prediction results, and systems need a single model with high performance. In this paper, a method is proposed to address the above challenges. We present a long short-time memory (LSTM) model with a special loss function and use the hyper-parameter search for accuracy optimization. To illustrate the performance, we employ them on the open dataset, Kaggle Rossman sales data. The experiment results show that compare with a series of machine learning models using the AutoML (Auto Machine Learning) tool, the proposed method significantly increased the performance of prediction on sparse data. Besides, it can reasonably overestimate or underestimate sales forecasts based on user preferences that meet the actual business demands.
Decision Support System in Detrmination of Project Tender Winner Using the Analytical Hierarchy Process (AHP) Method
Authors: Annas Firdaus , Ediana Dina , Kurniawan Asep , Wandira Raju , Zakir Supratman
Published: February 2021

Decision Support System (DSS) is a system that can help someone in making accurate and targeted decisions. Many problems can be solved by using DSS, one of which is the determination in the winner of the project tender. There are several methods that can be used in building a DSS, including Analytic Hierarchy Process (AHP). AHP is the most widely used method in solving multi-criteria problems, such as in determining the winner of a project tender. This study uses the AHP method in determining the winner of a project tender in the Procurement Services Unit (ULP) IAIN Bukittinggi. In determining the winner of a tender, there are several criteria that form the basis of decision making including administrative evaluation, technical evaluation, price evaluation and qualification evaluation. From the four criteria, it is processed according to alternative data, namely bidders. The application used in determining the winner of this tender is the Expert Choice software. The final results in this study are the results of global priority criteria that are sorted from highest to lowest, so that the committee can determine the winner of the tender.
The Validity and Practicality of Augmented Reality Based Learning Media for Computer Basics Courses
Authors: Anugrah Septriyan
Published: February 2021

“Augmented Reality is a technology that gets a lot of attention because it can combine text and image media into its world with these advantages Augmented reality is expected to be a solution in the need for learning media in this study will reveal the validity and practicality of augmented reality-based learning media with research subject students majoring in technology curriculum in the field of education at Padang State University with the results of the study showing that augmented reality based media is valid and practical for lecturers and students
Four-D Models Method Validation Analysis of an Android-Based Learning Media
Authors: Yunus Yuliawati , Fransisca Monica
Published: February 2021

This article presents the results of validation analysis of an android-based learning media that is applied to entrepreneurship subjects which specialized in tourism majors at vocational schools in Padang. The main object of this learning media was it can be accessed via mobile phone and this learning media accessible for teachers and students anytime, anywhere. The validation analysis of learning media was obtained from media experts and content experts. The validation results were used as reference for utilization of an android-based learning media at vocational school in Padang.
The Correlation of Students’ Perception About Online Learning and Students’ Grade Point at IAIN Bukittinggi
Authors: Sesmiarni Zulfani , Ahida Ridha , Iswantir
Published: February 2021

Abstract. This research is aimed to find correlation between students’ perception about online learning and students’ grade point average at Tarbiyah and Teacher Training Faculty IAIN Bukittinggi. Research population was all of Tarbiyah and Teacher Training Faculty students who registered active on even semester 2019/2020 that amounted to 3.335 students. Sample was chosen 10 % of the population, 333 students, using accidental sampling technique. Research instrument used questionnaire and distributed via Google form by using media like whatsapp group and email. Based on the finding, it was founded students’ perception about online learning at Tarbiyah and Teacher Training Faculty IAIN Bukittinggi classified into good and score gotten is 64. If it is reviewed from indicators which consisted of infrastructure, education management and human resource, the score of each indicators gotten is infrastructure aspect 63 classified into good, education management aspect 61 categorized into good and human resources aspect 68 classified into good. If it is reviewed from correlation of students’ perception about online learning and students’ grade point average, correlation coefficient (r) is 0,13 which means low or weak correlation. If it is compared between count correlation coefficient and table, it can conclude r count is bigger than r table means there is correlation between students’ perception about online learning and students’ grade point average.
The use of laser radiation to stimulate the growth of kohlrabi cabbage
Authors: Sevostyanova N N , Danilovskikh M G , Vinnik L I , Trezorova O Y , Pchelina EA
Published: February 2021

The paper analyzes data on the use of laser radiation to stimulate the growth and development of crops, describes the biochemical basis for the transmission of coherent radiation to the cell and the cellular response. The positive effect of using a semiconductor laser with a red spectrum of action with a wavelength of 658 nm is shown by the example of kohlrabi cabbage. An increase in the mass of stems, as well as an increase in the content of proteins and carbohydrates when using laser radiation, was shown.
Economic and mathematical model of the profit of sugar production from beets
Authors: Gromkovskii A I , Gromkovskii A A , Gromkovskaia N A
Published: February 2021

The economic sector of sugar production from beets in Russia is currently operating in a crisis of overproduction. The volume of sugar produced over the past few years exceeds the demand of the country’s population and the need for related processing industries. This economic situation led to a decrease in the market price of sugar, the formation of a deficit of working capital of enterprises. It arose a risk for unprofitable work of sugar factories. One of the main business processes that determine the efficiency of the company’s operation is to make a profit. Based on the analysis of the specifics of sugar production from beets, a mathematical model of the sugar factory’s profit was developed. The developed model takes into account all the components of the business process of making a profit that determine the efficiency of the sugar factory. Based on the developed mathematical model, it is possible to analyze the break-even operation of a sugar factory and determine the break-even point. The obtained mathematical model allows solving problems of optimal enterprise management, optimal design and reconstruction of sugar plants, and conducting financial audits. With the help of the developed mathematical model, the production activity of three sugar factories of different production capacities and different degrees of technical equipment is studied. The economic parameters of break-even operation of the studied enterprises are determined. Comparative analysis has shown the decisive role of effective production technologies in the break-even value.
The research of one-stage particle size-reduction process of blocked frozen meat with multiple cutting tools with milling operation method
Authors: Kapovsky B R , Plyasheshnik P I , Kuznetsova T G , Lazarev A A
Published: February 2021

This article shows experimental data about energy demands of innovative one-stage particle size-reduction process of frozen meat, formed in blocks, with milling operation method. We researched the particle size-reduction of meat blocks (beef and pork) by tools of different construction and shape of cutting edge: a slab mill with small edge and a fitted on shaving milling tool with a hard-faced knife. This study based on results of measuring three-phase active power, used by the cutting electric drive in working condition. The article presents the calculation of the measurements of numerical characteristics (mean value and mean square deviation) of statistical samples of power values with completing particle size-reduction tool with milling tools. The research shows that placing additional sustainer, that fixes a block of meat directly near the cutting zone, leads to decrease of energy demands for the cutting process up to 20% and to lower the dispersion of power values more than three times. The data obtained during the research let work out technical requirement specification for producing a commercial prototype of cutting particle size-reduction. The data allow creating the calculate method of numerical characteristics of a random process for a load of multiple razor tool in working condition. That model is used for designing an intellectual system of management of technological process on the transfer line for meat product producing with using one-stage particle size-reduction of raw materials with the milling method.
The Cloud Resource Forecasting Model Based HMM
Authors: Liu Han , Meng Hai-Ning , Zhang Tong , Qu Yi-Lin
Published: February 2021

One of the most important goals for companies that provide cloud computing services is to maintain high availability on large computer systems. In order to accomplish such objective, it is necessary to discovery the reason of poor availability. Software aging is a main factor in cloud computing services, leading to software failures, poor performances and may result in system downtime. This paper investigates the software aging effects on the OpenStack cloud computing platform and describes a forecasting model based on Hidden Markov Models. The prediction analysis of the Hidden Markov Models on the key performance data of the system shows that the Hidden Markov Models has excellent predictive performance and is suitable for the prediction of the reliability of the cloud server system.
Mechanical Characterization of New Geopolymeric Materials Based on Mining Tailings and Rice Husk Ash
Authors: Huamán-Mamani F.A. , Mayta-Ponce D.L. , Rodríguez-Guillén G.P.
Published: February 2021

This work presents the results of the thermomechanical evaluation of geopolymeric concrete fabricated from mining tailings, rice husk ash and fine sand. Ten types of geopolymeric concrete were studied and the relationship between the initial volumetric concentrations of the components in the mixtures and the maximum resistance in uniaxial compression under conditions of variable temperature (between ambient and 600 °C) was analyzed. The results revealed that increases in the concentration of mining tailings and fine sand lead to an increase in the value of the maximum mechanical resistance, in contrast, the increase in the concentration of rice husk ash led to a reduction in the value of the maximum mechanical resistance. Furthermore, increases in test temperature, up to 500 °C, led to systematic increases in maximum mechanical strength. Finally, the geopolymeric concretes presented a brittle-ductile transition between 500 and 600 °C showing only a ductile behavior when tested at 600 °C and only brittle up to test temperatures of 500 °C.
Evaluation of the Thermic Efficiency of the Prototype at Scale of a Sustainable Housing that Uses Concrete with PET Fibers (CFP) and the Trombe System
Authors: Dueñas B , Soto W , Carrera E
Published: February 2021

In the last century, climate change has been one of the most notorious consequences of global warming. These changes are manifested through extremely warm or icy temperatures. Being the latter, the one that affects Andean populations in diverse parts of the world. In view of this, many researchers propose various techniques or methods to improve the conditions of habitability and thermic comfort to confront these cold temperatures. This study conducts an experimental investigation of the improvement of thermic efficiency that reaches a prototype of housing to include polyethylene terephthalate (PET), as a component of the concrete mixture in the structural elements. For this purpose, studies were reviewed that allowed selecting the most optimal considerations, with respect to the elaboration and inclusion of PET in the mixture. In addition, the proposed technique includes an adaptation and innovation of the trombe system in the roof, in order to optimize the thermic properties. The results in the present study show that this combination has allowed us to considerably improve the thermal efficiency properties in the prototype of the housing, which is an indicator of its performance when it is applied to real scale housing.
Assessment of a Real-life Concrete Bridge Structure using Vibration-based Damage Detection Method
Authors: Aasim Bashir Ahmad , Karimi Abdul Khaliq , Tomiyama Jun
Published: February 2021

Structural damage is usually presented in the form of decrease in stiffness resulting changes in the dynamic behavior of the structure, and natural frequency of the structure being one of the dynamic variables. A vibration-based damage detection method was employed to evaluate the structural health condition of a deteriorated bridge. The bridge has been closed for the traffic due to owing the extreme deteriorated health condition because of the immense existence of chloride ion in the airborne particles of the saline environment. This study presents, the comparison of natural frequencies of the year 2017 to that acquired in the year 2016 using vibration-based damage detection method. Even though the bridge was not exposed to the service load during the study period, yet, the results manifested decrement in natural frequencies revealing decline in structural stiffness in this period.
Estimation of Measurement Uncertainty of Factor Assays Using the Monte Carlo Simulation
Authors: Lim Yong Kwan , Kweon Oh Joo , Lee Mi-Kyung , Kim Hye Ryoun
Published: February 2021

Objectives

We aimed to quantify the measurement uncertainty (MU) for factor activities using the Monte Carlo simulation (MCS), which is a computational algorithm that simulates statistical sampling to obtain numerical results through complex mathematical calculations.

Methods

The uncertainties of factor V (FV), factor VIII (FVIII), and factor X (FX) were simulated with two coagulation testing systems: ACL TOP 750 CTS (Instrumentation Laboratory) and STA Compact (Diagnostica Stago).

Results

When the factor activities were 74% (FV), 68% (FVIII), and 89% (FX), the MUs were 3.5% (FV), 9.3% (VIII), and 2.8% (FX) for ACL TOP and 8.5% (FV), 18.2% (FVII), and 6.5% (FX) for STA Compact. MCS MUs were compared with MUs obtained from running actual samples (not simulated) using a method called the top-down approach. The MCS MU results were interchangeable with MUs from the top-down approach, except for FVIII from STA Compact.

Conclusions

The MCS procedure is well suited for the quantification of MUs for factor assays over the entire measurement range.
Bortezomib for treatment of anti–NMDA receptor encephalitis in a pediatric patient refractory to conventional therapy
Authors: Simmons Marroyln L , Perez Kimberly A
Published: February 2021

Purpose

The case of a pediatric patient with treatment refractory anti–N-methyl-d-aspartate (NMDA) receptor encephalitis treated with the plasma cell–depleting therapy bortezomib is reported.

A 5-year-old female presented to the hospital with a 1-week history of altered mental status, agitation, and possible seizure-like activity. She was admitted to the hospital for suspected meningitis or meningoencephalitis and an extensive workup was completed, including sending blood and cerebrospinal fluid (CSF) for testing for NMDA receptor antibodies. While test results were pending, the patient was treated initially with intravenous immunoglobulin (IVIG) for 4 days followed by high-dose methylprednisolone for 5 days. The patient’s serum and CSF studies were positive for NMDA receptor antibodies, confirming the diagnosis of anti–NMDA receptor encephalitis. She was then treated with plasmapheresis therapy every other day for 5 treatments, without any clinical improvement. The patient then received rituximab once weekly for 6 weeks. Three weeks after completion of rituximab therapy, the patient was started on her first cycle of bortezomib therapy. She received a total of 6 cycles, with improvement in her clinical status beginning with the third cycle. Upon completion of 6 cycles, the patient’s mental status and level of functioning had greatly improved. She was discharged to an inpatient rehabilitation facility and ultimately able to return home to her family.

Conclusion

A 5-year-old female with anti–NMDA receptor encephalitis was successfully treated with bortezomib after having shown no clinical improvement during treatment with IVIG, high-dose methylprednisolone, plasmapheresis, and rituximab.
Creating Synergies between Citizen Science and Indigenous and Local Knowledge
Authors: Tengö Maria , Austin Beau J , Danielsen Finn , Fernández-Llamazares Álvaro
Published: February 2021

Citizen science (CS) is receiving increasing attention as a conduit for Indigenous and local knowledge (ILK) in ecosystem stewardship and conservation. Drawing on field experience and scientific literature, we explore the connection between CS and ILK and demonstrate approaches for how CS can generate useful knowledge while at the same time strengthening ILK systems. CS invites laypersons to contribute observations, perspectives, and interpretations feeding into scientific knowledge systems. In contrast, ILK can be understood as knowledge systems in its own right, with practices and institutions to craft legitimate and useful knowledge. Such fundamental differences in how knowledge is generated, interpreted, and applied need to be acknowledged and understood for successful outcomes. Engaging with complementary knowledge systems using a multiple evidence base approach can improve the legitimacy of CS initiatives, strengthen collaborations through ethical and reciprocal relationships with ILK holders, and contribute to better stewardship of ecosystems.
Visions of the Common Good: Engelhardt’s Engagement with Catholic Social Teaching
Authors: Eberl Jason T
Published: February 2021

In this paper, I confront Engelhardt’s views—conceptualized as a cohesive moral perspective grounded in a combination of secular and Christian moral requirements—on two fronts. First, I critique his view of the moral demands of justice within a secular pluralistic society by showing how Thomistic natural law theory provides a content-full theory of human flourishing that is rationally articulable and defensible as a canonical vision of the good, even if it is not universally recognized as such. Second, I defend the principles of Roman Catholic social teaching (RCST) against Engelhardt’s objection that it constitutes a watered-down version of the Christian moral vision which opens the door to intolerable moral compromises. While I acknowledge that Engelhardt’s criticism of RCST is well-grounded in certain abusive compromises that have been made by some Catholic healthcare institutions, I contend that such abuses are not endemic to RCST and avoidance of them is practically feasible in contemporary secular pluralistic societies. My primary aim is to show how continued dialogue between Engelhardtian libertarians and more communitarian-inclined RCST proponents may constructively yield a vision of healthcare allocation that ensures succor for the least advantaged within an authentically Christian social ethic.
Conscientious Objection or an Internal Morality of Medicine?
Authors: Hershenov David
Published: February 2021

Doctors, nurses, and pharmacists who refuse on grounds of conscience to participate in certain legal, expected, and standard practices have been accused of unprofessionally introducing their personal views into medicine. My first response is that they often are not engaging in conscientious objection because that involves invoking convictions external to those of the medical community. I contend that medicine, properly construed, is pathocentric, and so refusing to induce a pathology via abortion, contraception, euthanasia, etc., is actually being loyal to the internal morality of medicine. My second response is that even if such refusals are best considered conscientious objection, there is still no personal hijacking of medicine. Doctors refusing to induce pathologies need not refuse qua Christian, but can do so qua doctor. A pathocentric account of medicine provides a principled way of distinguishing conscientious objection from religious, idiosyncratic, and bigoted refusals. Patients’ refused pathology-inducing procedures are not medically harmed.
Development of an Ion-Pair Dispersive Liquid–Liquid Microextraction Method Based on a Ternary Deep Eutectic Solvent for Determination of Some Herbicide Residues in Edible Oil Samples
Authors: Torbati Mohammadali , Gonbari Milani Payam , Farajzadeh Mir Ali , Afshar Mogaddam Mohammad Reza
Published: February 2021

An ion-pair deep eutectic solvent (DES)-based dispersive liquid–liquid microextraction method was introduced and applied for the extraction of some acidic herbicides from edible oil samples prior to their determination by high performance liquid chromatography. First, a ternary DES composed of decanoic acid, dichloroacetic acid, and phosphocholine chloride is prepared under mild conditions. Then, the analytes are extracted into an alkaline solution from the oil samples by deprotonation of the herbicides. Afterward, the deprotonated analytes are extracted into the prepared DES with the aid of tri-butyl amine (as an ion-pair agent) in the presence of acetic acid (as a pH adjustment agent and dispersive solvent). The validation parameters indicated that the method has low limits of detection (0.09–0.72 ng mL−1) and quantification (0.30–2.3 ng mL−1), an acceptable percision (relative standard deviation ≤  9.0%) and high extraction recoveries (85–94%), and enrichment factors (566–626). The method was used in the analysis of 35 edible oil samples to assessment the studied analytes and the presence of haloxyfop was confirmed in three corn oils.
The Benefits and Harms of Antibiotic Prophylaxis for Urinary Tract Infection in Older Adults
Authors: Langford Bradley J , Brown Kevin A , Diong Christina , Marchand-Austin Alex , Adomako Kwaku , Saedi Arezou , Schwartz Kevin L , Johnstone Jennie , MacFadden Derek R , Matukas Larissa M , Patel Samir N , Garber Gary , Daneman Nick
Published: February 2021

Background

The role of antibiotics in preventing urinary tract infection (UTI) in older adults is unknown. We sought to quantify the benefits and risks of antibiotic prophylaxis among older adults.

Methods

We conducted a matched cohort study comparing older adults (≥66 years) receiving antibiotic prophylaxis, defined as antibiotic treatment for ≥30 days starting within 30 days of a positive culture, with patients with positive urine cultures who received antibiotic treatment but did not receive prophylaxis. We matched each prophylaxis recipient to 10 nonrecipients based on organism, number of positive cultures, and propensity score. Outcomes included (1) emergency department (ED) visit or hospitalization for UTI, sepsis, or bloodstream infection within 1 year; (2) acquisition of antibiotic resistance in urinary tract pathogens; and (3) antibiotic-related complications.

Results

Overall, 4.7% (151/3190) of UTI prophylaxis patients and 3.6% (n = 1092/30 542) of controls required an ED visit or hospitalization for UTI, sepsis, or bloodstream infection (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.12–1.57). Acquisition of antibiotic resistance to any urinary antibiotic (HR, 1.31; 95% CI, 1.18–1.44) and to the specific prophylaxis agent (HR, 2.01; 95% CI, 1.80–2.24) was higher in patients receiving prophylaxis. While the overall risk of antibiotic-related complications was similar between groups (HR, 1.08; 95% CI, .94–1.22), the risk of Clostridioidesdifficile and general medication adverse events was higher in prophylaxis recipients (HR [95% CI], 1.56 [1.05–2.23] and 1.62 [1.11–2.29], respectively).

Conclusions

Among older adults with UTI, the harms of long-term antibiotic prophylaxis may outweigh their benefits.
Effectiveness of the Recombinant Zoster Vaccine in Adults Aged 50 and Older in the United States: A Claims-Based Cohort Study
Authors: Sun Yuwei , Kim Eric , Kong Christina L , Arnold Benjamin F , Porco Travis C , Acharya Nisha R
Published: February 2021

Background

The recombinant zoster vaccine had over 90% efficacy in preventing herpes zoster in clinical trials. However, its effectiveness outside of a clinical trial setting has not been investigated. This study aimed to assess the effectiveness of the recombinant zoster vaccine in general practice.

Methods

A de-identified administrative claims database, the OptumLabs Data Warehouse, was used to conduct this retrospective cohort study to assess the effectiveness of the recombinant zoster vaccine against herpes zoster in nonimmunocompromised, vaccine age–eligible individuals enrolled in the database for ≥365 days.

Results

A total of 4 769 819 adults were included in this study, with 173 745 (3.6%) adults receiving 2 valid doses of the recombinant zoster vaccine. The incidence rate of herpes zoster was 258.8 (95% confidence interval [CI], 230.0–289.4) cases per 100 000 person-years in vaccinated persons compared with 893.1 (95% CI, 886.2–900.0) in unvaccinated persons. Recombinant zoster vaccine effectiveness was 85.5% (95% CI, 83.5–87.3%) overall, with an effectiveness of 86.8% (95% CI, 84.6–88.7%) in individuals 50 to 79 years old compared with 80.3% (95% CI, 75.1–84.3%) in individuals aged 80 and older. In patients with a history of live zoster vaccine within 5 years of study inclusion, vaccine effectiveness was 84.8% (95% CI, 75.3–90.7%).

Conclusions

Recombinant zoster vaccine effectiveness against herpes zoster was high in a real-world setting. Given the low vaccine coverage and high effectiveness, a major public health effort is needed to identify and address barriers to vaccination and increase immunization rates.
Implementation of a Rapid Phenotypic Susceptibility Platform for Gram-Negative Bloodstream Infections With Paired Antimicrobial Stewardship Intervention: Is the Juice Worth the Squeeze?
Authors: Robinson Evan D , Stilwell Allison M , Attai April E , Donohue Lindsay E , Shah Megan D , Hill Brandon K , Elliott Zachary S , Poulter Melinda , Brewster Frankie , Cox Heather L , Mathers Amy J
Published: February 2021

Background

Implementation of the Accelerate PhenoTM Gram-negative platform (RDT) paired with antimicrobial stewardship program (ASP) intervention projects to improve time to institutional-preferred antimicrobial therapy (IPT) for Gram-negative bacilli (GNB) bloodstream infections (BSIs). However, few data describe the impact of discrepant RDT results from standard of care (SOC) methods on antimicrobial prescribing.

Methods

A single-center, pre-/post-intervention study of consecutive, nonduplicate blood cultures for adult inpatients with GNB BSI following combined RDT + ASP intervention was performed. The primary outcome was time to IPT. An a priori definition of IPT was utilized to limit bias and to allow for an assessment of the impact of discrepant RDT results with the SOC reference standard.

Results

Five hundred fourteen patients (PRE 264; POST 250) were included. Median time to antimicrobial susceptibility testing (AST) results decreased 29.4 hours (P < .001) post-intervention, and median time to IPT was reduced by 21.2 hours (P < .001). Utilization (days of therapy [DOTs]/1000 days present) of broad-spectrum agents decreased (PRE 655.2 vs POST 585.8; P = .043) and narrow-spectrum beta-lactams increased (69.1 vs 141.7; P < .001). Discrepant results occurred in 69/250 (28%) post-intervention episodes, resulting in incorrect ASP recommendations in 10/69 (14%). No differences in clinical outcomes were observed.

Conclusions

While implementation of a phenotypic RDT + ASP can improve time to IPT, close coordination with Clinical Microbiology and continued ASP follow up are needed to optimize therapy. Although uncommon, the potential for erroneous ASP recommendations to de-escalate to inactive therapy following RDT results warrants further investigation.
Fine-scale conditions across mangrove microhabitats and larval ontogeny contributes to the thermal physiology of early stage brachyurans (Crustacea: Decapoda)
Authors: Vorsatz L D , Pattrick P , Porri F
Published: February 2021

Most marine ectotherms require the successful completion of a biphasic larval stage to recruit into adult populations. Recruitment of larvae into benthic habitats largely depends on biological interactions and favourable environmental conditions such as the inescapable diurnal thermal and tidal exposures. Hence, assessing how different taxa metabolically respond to variations in temperature is imperative to understand the community and ecosystem dynamics at both local and global scales. The present study aimed to investigate the effects of acute temperature variation on the physiology of stage-specific brachyuran larvae collected from different microhabitats at two mangrove forests in South Africa. Results indicate that the conditions within microhabitats, which larvae experience, likely influence their physiology, based on respirometry, to short-term acute temperature exposures. Furthermore, the larval thermal optimum shifted ontogenetically to become increasingly eurythermic as individuals developed from stage I zoea through to megalopa. Mangrove crab larvae in their early stages are hence increasingly vulnerable to acute temperature exposures, which could be particularly harmful to the persistence of populations if thermally stressful events increase in magnitude and frequency.
Does automated left ventricular ejection fraction assessment available on handheld ultrasound devices represent improvement in the diagnostic accuracy?
Authors: Filipiak D , Kasprzak JD , Szymczyk E , Wejner-Mik P , Wdowiak-Okrojek K , Lipiec P
Published: February 2021

Funding Acknowledgements

Type of funding sources: None.

Purpose

To assess the accuracy of an algorithm for automated measurement of the left ventricular ejection fraction (LVEF) available on handheld ultrasound device (HUD).

Methods

112 patients admitted to the cardiology department, who were referred for the conventional echocardiographic examination, underwent additional assessment performed with HUD (Vscan Extend, GE Vingmed Ultrasound, Horten, Norway). In each case 4 – chamber apical view was obtained and LVEF was calculated by means of the LVivo software. Imaging quality was assessed in a 4-grade scale. Subsequently, during the examination performed with the use of the stationary echocardiograph the three-dimensional (3D) measurement of LVEF was recorded.

Results

Ultimately 96 (53 men, mean age 63 ± 11) patients were enrolled into the study group  In the remaining 16 cases (14%) 3D image quality was not sufficient to allow the calculation of the LVEF. LVivo software was unsuccessful in calculating LVEF in all these 16 patients and in additional 20 patients, who remained in the study group due to satisfactory 3D image quality.

The quality of images acquired with the use of HUD was assessed as optimal in 25 (26%) patients, good in 37 (39%), acceptable in 24 (25%), poor in 10 (10%).

The average LVEF value was 46%±14 with the 3D LVQ measurements and 48%±14 using the LVivo software. The correlation coefficient between  the LVEF values obtained with the two methods was  r = 0,92; (P < 0,0001). Using paired samples t-test we found that the difference between these two techniques was not significant (mean difference 4,5± 3,4%; P = 0,35).

LVivo software EF assessment is based on a single apical view and for this reason we have assumed that the differences in EF can be larger in patients with regional wall motion abnormalities, in whom LVEF values derived from different apical views can significantly vary. For this reason the group of patients with history of myocardial infarction (40pts, 42%) was analysed separately and we found that the difference between LVivo and 3D LVEF was also not statistically significant (mean difference 6,1± 3,3%; P= 0,14). The correlation coefficient equalled  r = 0,78; (P < 0,0001).

Conclusion

The LVivo software despite its limitations is capable of the accurate LVEF measurement when the acquired views are of at least good imaging quality. Such expanded capabilities of HUDs can potentially lead to the overall improvements of the diagnostic accuracy of the ultrasonographic examinations, particularly when in hands of the non-expert echocardiographers.
3D ultrasound coronarography: first proof of concept study on isolated beating rat hearts
Authors: Demeulenaere O , Mateo P , Sandoval P , Villemain O , Tanter M , Papadacci C , Pernot M
Published: February 2021

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Bettencourt Foundation

Background/Introduction

We demonstrated recently that Ultrafast ultrasound Doppler imaging can image the intramyocardial coronary circulation in beating hearts of large animals and patients [1]. Yet, ultrasound spatial resolution remains limited by wave physics and coronaries smaller than ∼100 µm could not be imaged. Ultrasound Localization Microscopy (ULM) [2] was recently introduced to tackle this issue and exploit the micrometric localization of microbubble contrast agents at ultrafast frame rate in order to image blood flows in micrometer vessels.

Purpose

The objective of this work was to demonstrate that 3D ultrafast ultrasound with contrast agents can provide the full 3D mapping of the coronary microcirculation with quantitative flow velocity on a beating rat heart.

Methods

Acquisitions were performed on ex vivo rat hearts (n = 5) with retrograde perfusion (Langendorff

model). A flow of a Krebs–Henseleit solution mixed with a diluted microbubbles solution (0.22%) was perfused at controlled pressure into the coronary arteries (between 5 and 15 mL/min). We used a 32 × 32 elements, 8-MHz matrix-array ultrasound transducer connected to a 1024-channel programmable ultrasound scanner. An ultrafast Doppler imaging sequence consisting of 9 plane waves was transmitted at a PRF of 20 kHz during 270 ms and repeated 40 times. After beamforming and SVD clutter filtering, the microbubbles were localized and tracked in 3D. Flow velocity were mapped at baseline and after infusion of Adenosine (10e-5 µMol) at constant coronary perfusion pressure (120 mm Hg). Eventually, the hearts were fixed using formaldehyde perfusion and imaged by µCT after injection of radio opaque agent.

Results

We successfully imaged the coronary blood flows of entire rat hearts. It revealed the entire vasculature from large main coronaries arteries (cross section up to 1 mm) to small arterioles (smaller than 40 µm). Coronary flow velocities ranged from [1 – 50] cm/s depending on the arteries diameter. Velocity estimates were validated in vitro in tubes of Ø0.58mm and were in good agreement with theoretical values of a Poiseuille’s flow (relative ratio of 10% for maximum velocities). After Adenosine infusion, perfusion flow rates increased 102% ± 50% (p < 0.05) on average. Eventually, anatomy revealed by 3D ultrasound coronarography was in accordance with the anatomy revealed by the µCT.

Conclusion(s)

We demonstrated the feasibility of 3D ultrasound coronarography on isolated beating rat hearts. This technique has the potential to become a novel imaging tool to investigate the coronary micro-circulation and quantify non-invasively the Coronary Flow Reserve (CFR).

Abstract Figure. Ultrasound coronarography