bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the ways to increase the urban street and road network capacity
Authors: Pospelov P I , Martiakhin D S , Komarova T K , Nemchinov DM
Published: July 2021

During the existing situation assessment on the urban road network and intersections design, it is necessary to establish the traffic capacity value of streets and its elements. When forecasting the capacity value it is necessary to turn traffic flow presented by different vehicles to uniformity expressed in the equivalent number of passenger cars by using passenger car equivalent coefficients (PCE). PCE currently used in the Russian Federation are formed on the capacity studies of the street-road network, carried out in the 70s-80s of the last century on rural roads, where the traffic flow was mostly presented by heavy vehicles. Nowadays the major percentage of traffic flow is presented by passenger cars. At the same time, the dynamic performances of trucks and buses have changed significantly. In this regard, the question of clarifying the traffic flow composition and revising the passenger car equivalent coefficients becomes urgent. High level of streets congestion and intersections with a small heavy vehicle percentage in the traffic flow is most often observed in large cities. The studies were carried out on the the multi-lane highway in Moscow in the sections free from the intersections and junctions influence. The purpose of the study was to clarify the traffic flow composition and determine the passenger car equivalent coefficients in modern traffic conditions.
Analysis of the properties of new forms of transitional sections of railway and highway curves
Authors: Velichko G V , Pospelov P I
Published: July 2021

The properties of new forms of transitional sections of curves of railways and highways are largely determined by the specific features of the design and functioning of the systems “railway line-rolling stock” and “driver-car-road”. Taking them into account had a significant impact on the formalization of targets and criteria for the quality of the functioning of these systems, as well as on the mathematical means and methods of their achievement. The results obtained in this case significantly differ from the traditional ones. The geometric differences between the transitional sections of railways are in the nonlinear regularities of strictly monotonic, G4 smooth changes in the curvature of their line axis and G3 smooth cross slope, which are described by non-identical functions with variable properties. At the same time, the quality of movement, assessed at the design level of the rolling stock, is ensured by the harmonization of the length of the transition section and the variable properties of its functions with the given characteristics of other properties of the system. The differences between the transitional sections of highways consist in the inclusion of the calculated speed and the speed of its change directly into the principle of the trajectory curvature of vehicles. This ensures the safety and convenience of curvilinear movement of cars on them both at constant and variable speeds. The theoretically substantiated potential for the improvement of the quality of functioning of these systems with the proposed solutions determines the reasonability of their comprehensive testing in practice and further improvement of the theory, norms and rules for the design of transitional sections of curved rail and highways.
Computing information and control complex for control of road construction machines
Authors: Maksimychev O I , Mezentsev K N , Yakubovich A N , Libenko A V , Guryanov V M
Published: July 2021

The article considers a model of the digging process carried out during the operation of a road-building machine, identifies the controlled and control parameters of the model. Based on the results of numerical simulation, it is shown that a rigid control algorithm is capable of providing effective results only in cases where most of the operating parameters of the machine do not go beyond the optimal area. To improve the efficiency of control and expand the permissible range of parameters of the state of the machine, it is proposed to use control based on fuzzy logic. The structure of synthesis of algorithms for fuzzy control of road-building machines is given. For the purpose of practical implementation of a fuzzy control algorithm, a basic model has been built, which includes 10 linguistic rules, on the basis of which chains of actions are formed during the operation of a machine. When implementing a fuzzy control model for the main parameters of the state of the machine, it is proposed to use triangular membership functions. The fuzzy inference surface for the fuzzy control algorithm is obtained and visualized, which makes it possible to efficiently search for the optimal trajectory of the control parameter function. An agent-based traffic model is considered, which describes the movement of road-building vehicles on a site and uses active and proactive algorithms. The results of numerical modeling confirm the feasibility of considering a variety of road-building machines at the site of joint work execution as a multi-agent system with elements of self-organization (CDPS-system). The maximum effect of self-organization is observed when the distance between the machines is changed, when they are uniformly located on the site. The expediency of combining local systems of automatic control of road-building machines into a single information and control complex is substantiated, a list of information and control tasks to be solved by the complex is formulated, and its structural diagram is synthesized.
Prospects for the use of composite and polymer materials in transport construction
Authors: Nadezhdin V S , Gruzdev A S , Titov O V
Published: July 2021

The article discusses the prospects for the use of road construction elements made of composite and polymer materials. Currently, the main materials used in the production of road infrastructure elements are metal, concrete and plastic. The use of modern polymeric materials will eliminate the disadvantages of the materials used with the same advantages. The study considers the possibility of replacing steel energy-absorbing elements of frontal road barriers with energy-absorbing elements, which are made of a polymer material based on ultra-high molecular weight polyethylene (UHMWPE). The comparison was carried out on the basis of digital modeling of a vehicle collision with a frontal road barrier according to the energy absorption criterion using the LS-Dyna nonlinear dynamics software package. The developed digital models are validated by bench and field tests. Based on the results of the virtual tests, the dimensions of the energy-absorbing elements of the polymer structure of the frontal road fence were selected, which in their properties is not inferior to the used metal analogue. The results obtained prove the prospects of using modern composite and polymer materials in road safety systems.
Mathematical model of an intelligent decision support system for road quality management
Authors: Abbasov E M , Teodorovich N N , Sidorova N P , Abbasova T S
Published: July 2021

The experience of operation of decision support systems is analyzed, it is shown that the existing principles of creating these systems do not take into account the failure and change in the performance of individual service element, which depend on the current load on the system. The definition of an adaptive decision support system as an intelligent system that works in an automated mode and is able to function in a changing environment, its internal structure, knowledge base, regulatory framework for management, support tools, system users is given. The tasks of construction a mathematical model of an adaptive decision support system and determining its objective function are set. A distributed decision support system, which receives information containing data from various input sources was studied. For construction a mathematical model of the system under investigation, the procedures for selecting mathematical models and methods of queuing theory were used. To assess the quality and effectiveness of an adaptive decision support system, simulation modeling is proposed.
Production of modifying additives for highways
Authors: Kolosov A D , Kondrat’ev V V , Kononenko R V , Guseva E A
Published: July 2021

The article presents a description and operating parameters of the technological process for the production of modifying additives for concrete and asphalt concrete based on exhaust gas dust in the production of silicon by operations. Described is a foam product, which is a raw material for obtaining fullerene-like carbon, a modifying additive MD2, and a chamber product for spherical silicon dioxide, a modifying additive MD1. The regulated parameters have been worked out, the regulation limits and the norms of expenses are given. The development of a functional diagram is based on the analysis of the technological process, as an object of automation, in which the main control and controlled influences are distinguished, which must be regulated and maintained within specified limits, in order to obtain the final product with the required quality characteristics. The implementation of this scheme is presented in this work. It combines a flow diagram and technical means measuring, controlling and regulating these flows, in order to ultimately obtain products of the desired quality.
Development of an algorithm for the introduction of innovative technologies in the construction of roads
Authors: Dudina I V , Skorobogatova Y A , Arkhipkin O V , Bovkun A S
Published: July 2021

This article provides an analysis of the current state of the road industry in Russia. There are factors that increase the demand for innovative road construction technologies. The authors have developed an algorithm for the introduction of innovative technologies in road construction. The algorithm developed by the authors will allow road construction enterprises to make informed decisions in choosing the directions of their development. It also enables an enterprise to more clearly identify its market positions and take measures to improve them, solve problems and increase the efficiency of its activities.
Assessment of the deformation and strength properties of parts manufactured using additive technologies, depending on the connection method and operating conditions
Authors: Nefelov I S , Baurova N I
Published: July 2021

The manufacture of dimensional parts on 3D printers with a small working area for printing leads to the need to separate the model into parts, print them separately and join them after the end of printing. The paper considers various ways of joining plastic products obtained by 3D printing methods. Samples were made, parts of which were connected in the process of research in the three considered ways. The tests were carried out in accordance with the requirements of GOST 11262-2014 “Plastics. Tensile tests”. The evaluation of the deformation and strength characteristics of the joints at different temperatures (+ 20°C, −30°C, −50°C) was carried out. It has been established that negative temperatures do not have a negative effect on the deformation and strength characteristics of the joints of parts made of ABS plastic. The results of tensile tests are presented. The use of the technology proposed by the author for joining plastic parts at enterprises engaged in the manufacture and repair of dimensional products will allow expanding the range of products without significant changes in the material and technical base.
Energy efficiency of autonomous vehicles on hilly roads
Authors: Shadrin S
Published: July 2021

Energy efficiency is traditionally among the main development trends in the automobile industry. We suspected that intelligent speed control systems can provide economic and ecological benefits for implementing civil autonomous driving technologies. We introduced the approach for autonomous driving, which is based on the analysis of the precise Digital Terrain Model (DTM) and optimal vehicle control actions with respect to a requested transport task, which can be a task of fuel or energy economy in this particular case. We addressed the research question of fuel economy estimation with respect to the reference parameter that is applicable to compare different control algorithms. We demonstrated the use of roadway-related factors of DTM to affect fuel consumption. We contributed the algorithm for saving fuel while driving on a hilly road and examined the influence of vehicle load on possible economy values. We compared fuel and energy-saving values of gasoline and electric vehicles based on the same chassis with and without use of the proposed algorithm. Practical results of tests on public roads are presented.
Modern methods of the digital virtual analysis for design and tests of road vehicle restraint systems
Authors: Demiyanushko I
Published: July 2021

Widespread introduction of information technologies of virtual digital testing to reproduce vehicle impacts against vehicle restraint systems with simulation impact modeling road safety barriers, crash cushions, terminals, removable barrier sections, transitions and passive safety devices, is one of the main actions providing decline in mortality on roads as a result of the road accidents. On this basis the so-called “Virtual Digital Proving Ground” (Virtual Test House) for testing of road arrangement elements is developed. The researches, conducted for its development are based on use of modern world-class software products and numerical methods of mechanics. Digital modeling of crash-situations with arrival of vehicles on elements of road arrangement, allows to solve complex problems of the analysis of new designs now, to investigate behavior of vehicles at with arrival on the design. Implementation of intellectual systems of automated management of vehicles does not give the chance to hope for the exception of refusals, both the equipment, and control systems, that does the problem of development of the innovation passive safety systems extremely relevant. Research and development carried out MADI by the general research team together with LLC M&PQ allowed to take the major step in advance of works on increase in safety on roads, to create tools for design of new innovations, to develop reasonable standards in the field of the road systems of passive safety. In article prospects the development of these researches in scientific and practical directions and for the purpose of increase in competences of educational programs are considered.
Reduction and equalization of thermal loading of contact pairs of the friction unit
Authors: Polyakov P A , Litvinov A E , Polyakova E A , Fedotov E S , Golikov A A , Zadayanchuk A E
Published: July 2021

Controlling the processes of interaction of the working pairs of the friction unit is possible when solving the problem of determining the parameters of influence. As the main criterion of the process, it is necessary to highlight the temperature on the surface of the friction unit. This paper presents a method for modeling the magnitude and distribution of temperature over the surface of a metal friction element depending on the nanogeometry of the surface profile of contact pairs of friction units. The ability to control the process of interaction of contacting pairs of the friction unit will further predict the life of the part and avoid such phenomena as burns and the formation of foci of microcracks.
Synthesis of oil-soluble corrosion inhibitors from raw materials of plant origin
Authors: Gaidar S M , Karelina M Yu , Quang Hoang Duc , Akulov A A
Published: July 2021

The use of low-soluble corrosion inhibitors based on raw materials of plant origin is one of the most promising methods of metalwork processing to prevent corrosion. Carbon acids with carbon radicals are used for the synthesis of such inhibitors, which participate in the formation of hydrophobic part of the molecule. It is known that the hydrophilic part of the molecule causes solubility in water, and the hydrophobic part-in hydrocarbons. The study found that by changing the structure of the hydrophilic and hydrophobic parts it is possible to obtain a substance that will dissolve in water as well as in hydrocarbons. The obtained organic compounds can be used as corrosion inhibitors, antiwear and antiadhesive additives. Therefore, by synthesizing carboxylic acids with various radicals and using them for treating metal surfaces, we can obtain not only anti-corrosion properties of the metal, but also anti-wear and anti-adhesion properties, which makes it possible to use inhibitors not only for protection against corrosion, but also for extending the service life of loaded or rubbing metal surfaces.
Hardy–Littlewood and Ulyanov inequalities
Authors: Kolomoitsev Yurii , Tikhonov Sergey
Published: July 2021

We give the full solution of the following problem: obtain sharp inequalities between the moduli of smoothness

ω
α

(
f
,
t

)
q

\omega _\alpha (f,t)_q

and

ω
β

(
f
,
t

)
p

\omega _\beta (f,t)_p

for

0
>
p
>
q
≤
∞

0>p>q\le \infty

. A similar problem for the generalized

K
K

-functionals and their realizations between the couples

(

L
p

,

W
p
ψ

)

(L_p, W_p^\psi )

and

(

L
q

,

W
q
φ

)

(L_q, W_q^\varphi )

is also solved.

The main tool is the new Hardy–Littlewood–Nikol’skii inequalities. More precisely, we obtained the asymptotic behavior of the quantity
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sup

T
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(

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,

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≤
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,

\begin{equation*} \sup _{T_n} \frac {\Vert \mathcal {D}(\psi )(T_n)\Vert _q}{\Vert \mathcal {D}({\varphi })(T_n)\Vert _p},\qquad 0>p>q\le \infty , \end{equation*}

where the supremum is taken over all nontrivial trigonometric polynomials

T
n

T_n

of degree at most

n
n

and

D

(
ψ
)
,

D

(

φ

)

\mathcal {D}(\psi ), \mathcal {D}({\varphi })

are the Weyl-type differentiation operators.

We also prove the Ulyanov and Kolyada-type inequalities in the Hardy spaces. Finally, we apply the obtained estimates to derive new embedding theorems for the Lipschitz and Besov spaces.
Global attractivity of a nonlocal reaction-diffusion viral infection model
Authors: Yang Yu , Zou Lan , Hsu Cheng-Hsiung
Published: July 2021

This paper is concerned with the global attractivity of a nonlocal reaction-diffusion viral infection model. By constructing suitable Lyapunov functionals, we show that the solutions of the model converge to a unique endemic equilibrium when the basic reproduction number is greater than one. The global attractivity for certain models with specific net growth rate and cell-to-cell transmissions are investigated as examples for illustration. Our results improve and generalize some known results.
Fingerprinting and Determination of Hepatotoxic Constituents in Polygoni Multiflori Radix Praeparata of Different Producing Places by HPLC
Authors: Zhou Gui , Feng Yi-Ming , Li Zhi-Cheng , Tao Li-Yu , Kong Wei-Song , Xie Rui-Fang , Zhou Xin
Published: July 2021

Polygoni Multiflori Radix Praeparata (PMRP) is used as Chinese herbal medicine with long history. However, reports about PMRP hepatotoxicity have increased recently, and producing area might be one reason. This article aims to figure out the relationship between producing area and hepatotoxic ingredients in PMRP. HPLC fingerprint for PMRP was established and the contents of gallic acid, trans-stilbene glycoside (TSG), emodin-8-O-β-D-glucoside (EG), emodin and physcion were determined. Clustering heatmap was implemented by TCMNPAS software，and principal component analysis was implemented by SPSS and SIMCA-P software. Hepatotoxic constituents’ contents of PMRP from separate producing area were different. PMRP from Guangxi had the highest content of gallic acid, TSG, EG, emodin and physcion, followed by Hubei, Guangdong, Guizhou, Yunnan. PMRP from Henan had the lowest contents of hepatotoxic components. Hepatotoxic components’ contents of PMRP in southern were higher than central China. This study carried out a preliminary qualitative and quantitative investigation on the PMRP from different producing places, which provided a basis for safe medication of PMRP.
Fertilization modifies forest stand growth but not stand density: consequences for modelling stand dynamics in a changing climate
Authors: Pretzsch Hans , Biber Peter
Published: July 2021

Knowledge of the maximum forest stand density and the self-thinning process is important for understanding, modelling and scheduling thinnings in silviculture. The upper trajectories of stem number, N, vs mean diameter, dq or mean tree volume vs stem number are often used for quantifying maximum stand density. The long debate about how site conditions modify these relationships is presently revived due to global change. A crucial question is whether environmental conditions alter the trajectories themselves or just the velocity at which stands move along them.

Our contribution is based on fully stocked plots from long-term Scots pine (Pinus sylvestris L.) fertilization experiments along an ecological gradient in South Germany. This allows us to compare the self-thinning trajectories of fertilized and unfertilized plots under different environmental conditions.

We can show that repeated fertilization with nitrogen did not change the N ~ dq trajectories. Assuming that fertilization affects forests in a similar way as an ongoing atmospheric N-deposition, this means that presently growth, mortality, and volume accumulation in forest stands proceed faster in time but still follow the same N ~ dq allometric trajectories. Furthermore, we found that the level of the self-thinning line generally increases with the annual precipitation. The allometric self-thinning exponent, however, did not respond to environmental conditions.

Finally, we quantitatively demonstrate and discuss the implications and consequences of the results regarding understanding and modelling forest stand dynamics, carbon sequestration and the development and adaptation of silvicultural guidelines in view of climate change.
Syndromic diagnostic testing: a new way to approach patient care in the treatment of infectious diseases
Authors: Dumkow Lisa E , Worden Lacy J , Rao Sonia N
Published: July 2021

Advanced microbiology technologies such as multiplex molecular assays (i.e. syndromic diagnostic tests) are a novel approach to the rapid diagnosis of common infectious diseases. As the global burden of antimicrobial resistance continues to rise, the judicious use of antimicrobials is of utmost importance. Syndromic panels are now being recognized in some clinical practice guidelines as a ‘game-changer’ in the diagnosis of infectious diseases. These syndromic panels, if implemented thoughtfully and interpreted carefully, have the potential to improve patient outcomes through improved clinical decision making, optimized laboratory workflow, and enhanced antimicrobial stewardship. This paper reviews the potential benefits of and considerations regarding various infectious diseases syndromic panels, and highlights how to maximize impact through collaboration between clinical microbiology laboratory and antimicrobial stewardship programmes.
The Rise and Fall of Isotonitazene and Brorphine: Two Recent Stars in the Synthetic Opioid Firmament
Authors: Vandeputte Marthe M , Krotulski Alex J , Papsun Donna M , Logan Barry K , Stove Christophe P
Published: July 2021

Synthetic opioids constitute one of the fastest-growing groups of new psychoactive substances (NPS) worldwide. With fentanyl analogues being increasingly controlled via classwide scheduling, many non-fentanyl-related opioids are now emerging on the recreational opioid market, rendering the landscape highly complex and dynamic. While new compounds are entering the supply in rapid and unpredictable manners, some recent patterns have become apparent. Many of these newly emerging opioids are being pirated from early patent literature and/or research papers, synthesized and sold online through various channels. Burdened by the identification of every newly emerging drug, many toxicology labs struggle to keep up. Moreover, by the time a ‘new’ drug is controlled via legislative measures, illicit drug markets will have already adapted and diversified as manufacturers work to avoid the restricted product(s). Hence, the typical life cycle of an NPS opioid is generally short (less than 6 months to 1 year), with only a few drugs escalating to significant numbers of detections. In this review, we summarize the key events in the emergence, rise and subsequent decline of two non-fentanyl opioids—isotonitazene and brorphine. These two opioids sequentially dominated the NPS opioid market in 2019 and 2020. Both isotonitazene and brorphine remained in circulation for over a year, each contributing to hundreds of deaths and adverse events. By detailing the life cycles of these opioids from their earliest synthesis as described in scientific literature to their subsequent rise and fall on recreational markets, this review illustrates the new characteristic life cycle of synthetic opioids in the ‘post-fentanyl-analogue’ era.
Screening Breast MRI and the Science of Premenopausal Background Parenchymal Enhancement
Authors: Vong Stephen , Ronco Anthony J , Najafpour Elham , Aminololama-Shakeri Shadi
Published: July 2021

The significance of background parenchymal enhancement (BPE) on screening and diagnostic breast MRI continues to be elucidated. Background parenchymal enhancement was initially deemed probably benign and followed or thought of as an artifact degrading the accuracy of breast cancer detection on breast MRI examinations. Subsequent research has focused on understanding the role of BPE regarding screening breast MRI. Today, there is growing evidence that a myriad of factors affect BPE, which in turn may influence patient outcomes. Additionally, BPE could represent an important risk factor for the future development of breast cancer. This article aims to describe the most up-to-date research on BPE as it relates to screening breast MRI in premenopausal women.
Thyroid hyalinizing trabecular adenoma with a high thyroglobulin level: a case report
Authors: Katano Hirofumi , Hasegawa Hisashi , Matsuzaki Hiroumi , Oshima Takeshi , Tang Xiaoyan
Published: July 2021

Thyroid hyalinizing trabecular adenoma (HTA) is a rare and borderline tumor of follicular origin. It is characterized by a trabecular growth pattern and marked intratrabecular hyalinization. Excessively elevated thyroglobulin levels have not been reported previously in cases without bilateral lung metastases. Here, we present a case of a 54-year-old woman with chronic thyroiditis with a 50-mm tumor in the left lobe of the thyroid gland, which was observed on ultrasonography. Her thyroglobulin level was found to be elevated at 684 ng/ml. Since fine needle aspiration cytology could not exclude possible malignancy, she underwent thyroid lobectomy; the final diagnosis was thyroid HTA. Two weeks after resection, her thyroglobulin level showed negative conversion. To our knowledge, this is the first report of a patient with a thyroid HTA exhibiting a thyroglobulin level as high as that for a patient with hyalinizing trabecular carcinoma.
Shaving Waivers in the United States Air Force and Their Impact on Promotions of Black/African-American Members
Authors: Ritchie Simon , Park Jisuk , Banta Jonathan , Bowen Casey , McCarthy Sean , Wong Emily , Garnier Romain , Beachkofsky Thomas
Published: July 2021

Introduction

Regulations of the United States Air Force (USAF) prohibit male members from growing beards. Shaving waivers can be issued to airmen who are not able to shave due to various medical conditions such as pseudofolliculitis barbae, a condition that predominantly affects Blacks/African-Americans. Beard growth has been anecdotally associated with a negative impact on career progression. This study sought to establish if shaving waivers are associated with delays in promotion and, if present, if this association leads to racial bias.

Materials and Methods

An online survey that collected information relating to shaving waivers and demographic data was emailed to all air force male members at 12 randomly selected air force bases. Generalized linear models were conducted to test the waiver group difference in promotion time controlling for rank and the covariates of race/ethnicity, level of education, professional military education completion, and disciplinary action.

Results

A total of 51,703 survey invitations were emailed to members, and 10,383 complete responses were received (20.08% response rate). The demographics of the study cohort closely matched that of the USAF. Shaving waivers were associated with a longer time to promotion (P = .0003). The interaction between race and waiver status was not significant, indicating that shaving waivers are associated with a similarly longer time to promotion in individuals of all races. However, 64.18% of those in the waiver group were Black/African-American despite only being 12.85% of the study cohort.

Conclusions

This study found an association between shaving waivers and delayed promotions. The majority of the waiver group was Black/African-American, which may lead to a racially discriminatory effect of the male grooming standards of the USAF.
Non-clinical repeated dose 28-day oral toxicity, reproductive toxicity and cytotoxicity studies of the polar fraction of Parkinsonia aculeata aerial parts extract
Authors: Menezes Tamires Meira , de Souza Franco Eryvelton , de Almeida Sousa Lima Larissa Caroline , de Souza Pereira Áurea Marcela , de Santos Lima Laísa Wanessa , Quixabeira Carla Mirele Tabósa , da Silva Janilson Felix , Cahu Thiago Barbosa , de Souza Bezerra Ranilson , Lira Eduardo Carvalho , Militão Gardênia Carmen Gadelha , de Sousa Maia Maria Bernadete
Published: July 2021

This study was aimed to evaluate toxicity in repeated doses for 28 days, reproductive toxicity and cytotoxicity of a polar fraction obtained from the hydroethanolic extract of Parkinsonia aculeata (PfrHEPA) in experimental models. To perform the toxicity test in repeated doses for 28 days, male and female Wistar rats were treated via orogastric for 28 days with PfrHEPA (35, 70 or 140 mg/kg) according to the guidelines established by the Organisation for Economic Co-operation and Development (OECD) number 407 (1995). For assessment, the impact of PfrHEPA on the reproductive output various parameters were measured, including maternal weight, no. of pregnant females, female fertility index (%), gestation lengthtime, implantation sites, litter size and placental index of test animals. The cytotoxicity of PfrHEPA was performed on the tumor lines NCI-H292 (human lung carcinoma), HL-60 (human promyelocytic leukemia) and HCT-116 (colorectal cancer). In the repeated dose toxicity test for 28 days, no mortality was observed in the male and female rats treated with PfrHEPA as well as morphological changes and biochemical and hematological parameters. In the reproductive toxicity test, no abnormalities were observed related to the toxicological parameters in both mothers and offspring. Regarding the cytotoxicity assay, the PfrHEPA fraction did not demonstrate significant cytotoxic effect on the cell lines analyzed. The present results suggest the use of PfrHEPA is safe and well tolerated in rats. Further studies are planned to identify and purify the active compounds for subsequent in vivo evaluation.
Revisioning Assessment and Evaluation in Nursing Education Through Critical Caring Pedagogy
Authors: Killam Laura A. , Camargo-Plazas Pilar
Published: July 2021

Instead of instilling in nursing students critical thinking to challenge injustice and oppression in nursing practice, nurse educators often rely on outdated traditional approaches to education. This situation is certainly true in traditional methods of evaluation that often propagate a banking mode of learning. One of the most commonly used methods of evaluating students is traditional examinations, which have recently become a source of pedagogical conflict among educators. In this article, we outline how educators unknowingly encourage surface learning, uncaring practices, oppression, inequity, and cheating when they rely on traditional examinations. We draw on critical caring pedagogy and universal design for learning to advocate for increased use of authentic assessment in nursing education. A Supplemental Digital Content video abstract is available at http://links.lww.com/ANS/A31.
Surgical Teams’ Attitudes About Surgical Safety and the Surgical Safety Checklist at 10 Years
Authors: Urban Denisa , Burian Barbara K. , Patel Kripa , Turley Nathan W. , Elam Meagan , MacRobie Ali G. , Merry Alan F. , Kumar Manoj , Hannenberg Alexander , Haynes Alex B. , Brindle Mary E.
Published: July 2021

Objective:

To assess health care professionals’ attitudes on the Surgical Safety Checklist (“the Checklist”) in resource-rich health systems and provide insights on strategies for optimizing Checklist use.

Background:

In use for over a decade, the Checklist is a safety instrument aimed at improving operating room communication, teamwork, and evidence-based safety practices.

Methods:

An online survey was sent to surgeons, nurses, and anesthesiologists in 5 high-income countries (Canada, the United States, the United Kingdom, Australia, and New Zealand). Survey results were analyzed using SPSS.

Results:

A total of 2032 health care professionals completed the survey. Of these respondents, 47.6% were nurses, 70.5% were women, 65.1% were from the United States, and 50.0% had 20 years of experience or more in their role. Most respondents felt the Checklist positively impacted patient safety (70.9%), team communication (73.1%), and teamwork (58.9%). Only 50.3% of respondents were satisfied their team’s use of the Checklist, and only 47.5% reported team members stopping to fully participate in the process. More nurses lacked confidence regarding their role in the Checklist process than surgeons and anesthesiologists combined (8.9% vs 4.3%). Fewer surgeons and anesthesiologists than nurses felt they received adequate training on the Checklist’s use (57.8% vs 76.7%).

Conclusions:

While most respondents perceive the Checklist as enhancing patient safety, not all surgical team members are actively engaging with its use. To enhance buy-in and meaningful use of the Checklist, health systems should provide more training on the Checklist with respect to its purpose and strengthening teamwork.
Dual Suture Button Fixation With Buttress Plate for Ankle Syndesmotic Injury
Authors: Sprowls Gregory R. , Maxwell Garrett T. , Kriel Hilda H. , Probe Robert A.
Published: July 2021

In this video, we present a unique approach to a purely ligamentous syndesmotic injury in a 16-year-old football player. Syndesmotic reduction was obtained using a large clamp and validated by matching fibular position to a fluoroscopic image of the contralateral ankle. Fixation was achieved using dual suture button devices in combination with a buttress plate. A small medial incision was used to protect the saphenous neurovascular bundle during button placement.
Knee Dislocation With Acute Anterior Cruciate Ligament Reconstruction and Posterior Cruciate Ligament and Medial Collateral Ligament Repair
Authors: Gajari Vamshi , Pritchett Charles , Obremskey William T.
Published: July 2021

This video depicts the materials and steps for the repair of a Schenck classification KD III multiligamentous injury in a patient who had bilateral injuries after his car pinned him to a cabinet in his garage. The video demonstrates acute allograft reconstruction of anterior cruciate ligament and primary repair of the avulsions of posterior cruciate ligament and medial collateral ligament in the patient.
Percutaneous Fixation of a Fifth Metatarsal Base Fracture
Authors: Lindsey Benjamin B. , Bakshi Neil K. , Holmes James R. , Talusan Paul G. , Walton David M. , Hearty Thomas M.
Published: July 2021

Owing to a vascular watershed, zone II and III fifth metatarsal base fractures commonly progress to nonunion without operative intervention. This article and the accompanying video demonstrate the use of intramedullary screw fixation for a fifth metatarsal base fracture and review treatment decisions involved with management of these injuries.
Pediatric Posterior Sternoclavicular Dislocation Closed Reduction and Management
Authors: Honeycutt Michael Wesley , Cox Kyle , Michaeli David , Hulon Brian , Brewer Jeffrey
Published: July 2021

Posterior sternoclavicular joint (SCJ) dislocations are rare shoulder girdle injuries. Despite the paucity of cases, posterior SCJ dislocations pose an important threat to patient safety because of the proximity of the medial clavicle to the mediastinum, resulting in possible compression and/or injury to these structures. Current guidelines recommend attempting closed reduction in the acute setting followed by open reduction if closed reduction is unsuccessful. This video highlights a case of posterior SCJ dislocation in a pediatric patient who presented with dyspnea after a football injury.
Proximal Humerus Fracture—Open Reduction Internal Fixation With an Expandable Intramedullary Nitinol Scaffold
Authors: Rogers Davis , Raad Micheal , Srikumaran Uma , Shafiq Babar
Published: July 2021

For the treatment of proximal humerus fractures, the intramedullary nitinol scaffold is a novel implant that has gained popularity and demonstrated promising 1-year outcomes as an alternative to bone grafting for providing intramedullary structural support to the humeral head. The aim of this video is to demonstrate the insertion of this device safely, while highlighting potential pitfalls, in a 67-year-old patient with a displaced, varus angulated 2-part proximal humerus fracture.
Impact of Fasting on Cardiovascular Outcomes in Patients With Hypertension
Authors: Hammoud Sabah , Kurdi Mazen , van den Bemt Bart J. F.
Published: July 2021

Fasting has been frequently practiced for religious or medical purposes worldwide. However, limited literature assesses the impact of different fasting patterns on the physiologic and cardiac-related parameters in patients with hypertension. This review aims to examine the effect of fasting on cardiovascular outcomes in hypertensive patients. Medline, Embase, and Cochrane library were systematically screened until March 2021 for observational prospective cohorts investigating the effect of fasting on cardiovascular outcomes. Articles were assessed by searching for hypertension and fasting, both as Medical Subject Headings (MeSH) terms and text words. The review included studies assessing Ramadan, intermittent, and water-only fasting. Water-only fasting reduces body weight, blood pressure, and lipolytic activity of fasting hypertensive patients without affecting average heart rate. Ramadan fasting enhances lipid profile, although it shows conflicting results for body weight, blood pressure, and heart rate variability. Considering the limited studies in this field, further research should be conducted to support the clinical impact of fasting on the cardiovascular health of patients with hypertension.
How Do Care Transitions Work?
Authors: Zwart Dorien L.M. , Schnipper Jeffrey L. , Vermond Debbie , Bates David W.
Published: July 2021

Background:

Failure of safe care transitions after hospital discharge results in unnecessary worsening of symptoms, extended period of illness or readmission to the hospital.

Objective:

The objective of this study was to add to the understanding of the working of care transition interventions between hospital and home through unraveling the contextual elements and mechanisms that may have played a role in the success of these interventions, and by developing a conceptual model of how these components relate to each other.

Research Design:

This was a qualitative study using in-person, semi-structured interviews, based on realist evaluation methods.

Subjects:

A total of 26 researchers, designers, administrators, and/or practitioners of both current “leading” care transitions interventions and of less successful care transition intervention studies or practices.

Measures:

The contextual elements and working mechanisms of the different care transition intervention studies or practices.

Results:

Three main contextual factors (internal environment, external environment, and patient population) and 7 working mechanisms (simplifiying, verifiying, connecting, translating, coaching, monitoring, and anticipating) were found to be relevant to the outcome of care transition interventions. Context, Intervention, Mechanism, and Outcome (CIMO) configurations revealed that, in response to these contextual factors, care transition interventions triggered one or several of the mechanisms, in turn generating outcomes, including a safer care transition.

Conclusion:

We developed a conceptual model which explains the working of care transition interventions within different contexts, and believe it can help support future successful implementation of care transition interventions.
Domino Free Flap Transfer Using a Superficial Circumflex Iliac Artery Perforator Flap for the Toe Flap Donor Site
Authors: Fuse Yuma , Yamamoto Takumi , Kageyama Takashi , Sakai Hayahito , Tsukuura Reiko , Yoshimatsu Hidehiko , Yamamoto Nana
Published: July 2021

Background

Toe-to-hand transfer is a favorable option for finger reconstruction, but donor site healing can be challenging. The superficial circumflex iliac artery perforator (SCIP) flap has yet to be used widely for toe reconstruction. The purpose of this report was to validate the efficacy of the sequential simultaneous free SCIP flap transfer for the toe flap donor site in a consecutive case series.

Methods

The medical records of 18 consecutive patients who underwent a simultaneous SCIP flap transfer and a toe-to-hand transplant were reviewed. Free SCIP flap reconstruction was performed in a simultaneous 2-team approach. The SCIP flaps were transferred to various toe flap donor sites: a great toe wraparound flap in 9 cases, a second toe distal phalangeal flap in 4 cases, a great toe osteo-onycho-cutaneous flap in 3 cases, a twisted wraparound flap in 1 case, and a great toe hemipulp flap in 1 case.

Results

The size of the SCIP flap ranged from 5 × 3 to 16 × 8 cm. A mean of the total operative time was 229.2 minutes (range, 118–441 minutes; SD, 75.8 minutes). All the SCIP and toe flaps survived completely. Minor wound dehiscence was seen in 2 cases, and the wound healed by conservative treatment. The mean follow-up period was 23.7 months (range, 7–44 months; SD, 9.7 months). No patient had gait dysfunction postoperatively.

Conclusions

A sequential SCIP flap transfer was performed simultaneously without additional time, allowing secure soft tissue coverage of the toe flap donor even with avascular tissue such as bone or tendon exposed. The sequential SCIP flap transfer can be a useful option for reconstruction of toe flap donor site, when multiple microsurgeons and microscopes are available.
Microvascular Flap Reconstruction for Head and Neck Cancers in Previously Operated and/or Radiated Neck
Authors: Shankhdhar Vinay K. , Mantri Mayur R. , Wagh Snehjeet , Thiagarajan Shivakumar , Chaukar Devendra , Jaiswal Dushyant , Mathews Saumya
Published: July 2021

Background

Microvascular reconstruction after oncologic resection with curative intent in recurrent or second primary cancer cases is challenging not only because of the complexity of the defect but also due to difficulty in finding suitable donor vessels in the neck that has already been subjected to surgery and subsequent adjuvant treatment. In our present study, we evaluated the success of free flaps, reexplorations, and factors associated with reexploration and with flap failures in previously operated and/or radiated neck.

Methods

In this retrospective study, we analyzed patients who underwent microvascular reconstruction from January 2016 to December 2018 in patients with previous surgery and/or radiation, considered as “already treated neck” (ATN). These cases were reviewed to analyze variables that included age, sex, indication for surgery (recurrence, second primary, osteoradionecrosis, and secondary reconstruction), duration since previous surgery or radiation, free flap done, donor vessels used, the need to go to the contralateral neck or outside the neck, need for vein grafts, flap reexploration rate, flap survival rate, and hospital stay of the patients. We also tried to identify factors that predisposed for a reexploration after performing reconstruction with a free flap in ATN.

Results

Of 1522 free flaps done, 371 patients were included in the study. Flap success rate was 90.8% in ATN, which was comparable to naive neck (94%; P = 0.108). The reexploration rate in ATN (16.2%) was significantly higher (P = 0.0003) than in naive neck (9.8%). The previous treatment (neck dissection) received [P = 0.001; odds ratio, 13.7 (1.87–101.6)] was the most significant predisposing factor, and patients undergoing osteocutaneous flaps were more prone to undergo reexplorations (P = 0.05). Side of anastomosis, vessel used for anastomosis, comorbidities, and time since previous treatment did not affect the reexploration rate significantly.

Conclusions

Microvascular reconstruction can be safely performed in ATN with good success rates, and it should not be a deterrent in whom free flap is required to achieve best functional outcome. However, it may be associated with increase in reexploration rates in the postoperative period. Patients having undergone a previous neck dissection are at more risk of undergoing this reexploration in comparison with radiotherapy (RT)/chemotherapy and radiotherapy (CTRT) alone.