bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinic-level and individual-level factors that influence HIV viral suppression in adolescents and young adults: a national survey in Kenya
Authors: Njuguna Irene , Neary Jillian , Mburu Caren , Black Danae , Beima-Sofie Kristin , Wagner Anjuli D. , Mugo Cyrus , Evans Yolanda , Guthrie Brandon , Itindi Janet , Onyango Alvin , Oyiengo Laura , Richardson Barbra A. , Wamalwa Dalton , John-Stewart Grace 
Published: April 2020

Objectives:
To determine clinic-level and individual-level correlates of viral suppression among HIV-positive adolescents and young adult (AYA) aged 10–24 years receiving antiretroviral treatment (ART).

Design:
Multilevel cross-sectional analysis using viral load data and facility surveys from HIV treatment programs throughout Kenya.

Methods:
We abstracted medical records of AYA in HIV care, analyzed the subset on ART for more than 6 months between January 2016 and December 2017, and collected information on services at each clinic. Multilevel logistic regression models were used to determine correlates of viral suppression at most recent assessment.

Results:
In 99 HIV clinics, among 10 096 AYA on ART more than 6 months, 2683 (27%) had unsuppressed viral load at last test. Among 16% of clinics, more than 80% of AYA were virally suppressed. Clinic-level correlates of individual viral suppression included designated adolescent spaces [aOR: 1.32, 95% CI (1.07–1.63)] and faster viral load turnaround time [aOR: 1.06 (95% CI 1.03–1.09)]. Adjusting for clinic-level factors, AYA aged 10–14 and 15–19 years had lower odds of viral suppression compared with AYA aged 20–24 years [aOR: 0.61 (0.54–0.69) and 0.59 (0.52–0.67], respectively. Compared with female patients, male patients had lower odds of viral suppression [aOR: 0.69 (0.62–0.77)]. Compared with ART duration of 6–12 months, ART for 2–5, above 5–10 or more than 10 years was associated with poor viral suppression (P < 0.001).

Conclusion:
Dedicated adolescent space, rapid viral load turnaround time, and tailored approaches for male individuals and perinatally infected AYA may improve viral suppression. Routine summarization of viral load suppression in clinics could provide benchmarking to motivate innovations in clinic-AYA and individual-AYA care strategies.
Brief report on combat trauma surgical training using a perfused cadaver model
Authors: Grabo Daniel , Polk Travis , Minneti Michael , Inaba Kenji , Demetriades Demetrios 
Published: April 2020

BACKGROUND
Surgical combat casualty care presents difficult training challenges. Although several high-fidelity simulation (SIM) techniques have emerged, none are able to fully integrate the many intricacies involved in the care of a complex trauma patient. Herein, we report the use of perfused fresh human cadaver model for training and assessment of forward surgical teams (FSTs).

METHODS
Forward surgical teams attend a 4-day combat trauma surgical skills course including focused on trauma exposures. A half-day SIM involves the entire surgical team in four sequential surgical scenarios that involve the neck, chest, abdomen, and extremities, as well as airway management and resuscitation. Teams undergo immediate debriefing and videotape review of team dynamics and technical skills, as well as times to completion of critical interventions.

RESULTS
The data evaluated include five initial demonstration courses in which training metrics were available. Each team included both a junior and experienced surgeon, anesthesiologists, and surgical scrub technicians. As FSTs progressed through SIMs, they demonstrated improvements in team dynamics and technical skills evaluations. There was considerable variability in the times to completion of critical intervention, particularly for control of cardiac and vascular injuries.

CONCLUSION
Initial evaluations support the use of this novel perfused cadaver model for the training and evaluation of military FSTs. Preliminary data highlight the utility for open vascular, thoracic, and other high-acuity/low-volume procedures critical to combat casualty care. Larger studies are needed for model optimization and further validation of an objective structured technical assessment tool.

LEVEL OF EVIDENCE
Care management, level V.
Radial versus femoral arterial access for trauma endovascular interventions: A noninferiority study
Authors: Adnan Sakib M. , Romagnonli Anna N. , Elansary Noha N. , Martinson James R. , Madurska Marta J. , Dubose Joseph J. , Scalea Thomas M. , Morrison Jonathan J. 
Published: April 2020

BACKGROUND
The majority of endovascular interventions for trauma are performed using transfemoral access (TFA). Transradial access (TRA) is a recently integrated alternative at the authors' institution. This noninferiority study compares the technical success and complication rate of TRA compared with TFA.

METHODS
All patients undergoing emergent endovascular interventions between March 2016 and March 2019 were identified from a prospectively maintained database. Data were collected on access type, complications, and procedural success. A noninferiority margin was established from previous randomized trials for technical success (0.475) and complications (0.015).

RESULTS
Over 3 years, 96 patients underwent TRA and 335 patients received TFA. The overall technical success rate was 98.1%, without significance based on access strategy (p = 0.078). All femoral arteries and 97.9% (n = 94) of radial arteries were accessed as intended. Complications occurred in 1.0% of TRA and 9.9% of TFA groups (p = 0.002). In the TFA group, complications included access site bleeding, hematoma, pseudoaneurysm, lower limb ischemia, and femoral artery thrombosis (n = 6, 14, 3, 3, and 4, respectively). In the TRA group, complications included radial artery thrombosis (n = 1). Transradial access procedural success and complication rate fell within the lower bound confidence interval of the noninferiority margin, demonstrated the noninferiority of TRA in this data set.

CONCLUSION
Transradial access in a cohort of trauma patients undergoing endovascular intervention does not appear to be inferior to TFA in relation to technical success and complications. For patients where groin access may be challenging, TRA is a useful, efficacious, and safe alternative. Longer-term study is required to fully characterize the advantages and disadvantages of TRA compared with TFA.

LEVEL OF EVIDENCE
Therapeutic V.
The shape of dendritic tips
Authors: Alexandrov Dmitri V. , Galenko Peter K. 
Published: April 2020

The present article is focused on the shapes of dendritic tips occurring in undercooled binary systems in the absence of convection. A circular/globular shape appears in limiting cases of small and large Péclet numbers. A parabolic/paraboloidal shape describes the tip regions of dendrites whereas a fractional power law defines a shape behind their tips in the case of low/moderate Péclet number. The parabolic/paraboloidal and fractional power law shapes are sewed together in the present work to describe the dendritic shape in a broader region adjacent to the dendritic tip. Such a generalized law is in good agreement with the parabolic/paraboloidal and fractional power laws of dendritic shapes. A special case of the angled dendrite is considered and analysed in addition. The obtained results are compared with previous experimental data and the results of numerical simulations on dendritic growth.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
How heterogeneity drives tumour growth: a computational study
Authors: Gomez Hector 
Published: April 2020

Although cancerous tumours usually originate from a single cell, they normally evolve into a remarkably heterogeneous agglomeration of cells. Heterogeneity is a pervasive and almost universal feature of tumours, but its origin and consequences remain poorly understood. Tumour heterogeneity has been usually associated with poor prognosis, but a better understanding of it may lead to more personalized diagnosis and therapy. Here, we study tumour heterogeneity developing a computational model in which different cell subpopulations compete for space. The model suggests that aggressive tumour subpopulations may become even more aggressive when they grow with a non-aggressive subpopulation. The model also provides a mechanistic explanation of how heterogeneity drives growth. In particular, we observed that even a mild heterogeneity in the proliferation rates of different cell subpopulations leads to a much faster overall tumour growth when compared to a homogeneous tumour. The proposed model may be a starting point to study tumour heterogeneity computationally and to suggest new hypotheses to be tested experimentally.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
Dynamics of particulate assemblages in metastable liquids: a test of theory with nucleation and growth kinetics
Authors: Alexandrova Irina V. , Alexandrov Dmitri V. 
Published: April 2020

This manuscript is devoted to the nonlinear dynamics of particulate assemblages in metastable liquids, caused by various dynamical laws of crystal growth and nucleation kinetics. First of all, we compare the quasi-steady-state and unsteady-state growth rates of spherical crystals in supercooled and supersaturated liquids. It is demonstrated that the unsteady-state rates transform to the steady-state ones in a limiting case of fine particles. We show that the real crystals evolve slowly in a more actual case of unsteady-state growth laws. Various growth rates of particles are tested against experimental data in metastable liquids. It is demonstrated that the unsteady-state rates describe the nonlinear behaviour of experimental curves with increasing the growth time or supersaturation. Taking this into account, the crystal-size distribution function and metastability degree are analytically found and compared with experimental data on crystallization in inorganic and organic solutions. It is significant that the distribution function is shifted to smaller sizes of particles if we are dealing with the unsteady-state growth rates. In addition, a complete analytical solution constructed in a parametric form is simplified in the case of small fluctuations in particle growth rates. In this case, a desupercooling/desupersaturation law is derived in an explicit form. Special attention is devoted to the biomedical applications for insulin and protein crystallization.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
Dissolution of polydisperse ensembles of crystals in channels with a forced flow
Authors: Ivanov Alexander A. , Alexandrov Dmitri V. , Alexandrova Irina V. 
Published: April 2020

A non-stationary integro-differential model describing the dissolution of polydisperse ensembles of crystals in channels filled with flowing liquid is analysed. The particle-size distribution function, the particle flux through an arbitrary cross-section of the channel, the particle concentration profile, as well as the disappearance intensity of particles are found analytically. It is shown that a nonlinear behaviour of solutions is completely defined by the source term of particles introduced into the channel. In particular, the model approximately describes the processes of dissolution and transport of drug microcrystals to the target sites in a living organism, taking into account complex dissolution kinetics of drug particles.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
From nucleation and coarsening to coalescence in metastable liquids
Authors: Alexandrov Dmitri V. , Alexandrova Irina V. 
Published: April 2020

The transition of a metastable liquid (supersaturated solution or supercooled melt) occurring from the intermediate stage (where the crystals nucleate and grow) to the concluding stage (where the larger particles evolve at the expense of the dissolution of smaller particles) is theoretically described, with allowance for various mass transfer mechanisms (reaction on the interface surface, volume diffusion, grain-boundary diffusion, diffusion along the dislocations) arising at the stage of Ostwald ripening (coalescence). The initial distribution function (its ‘tail’) for the concluding stage (forming as a result of the evolution of a particulate assemblage during the intermediate stage) is taken into account to determine the particle-size distribution function at the stage of Ostwald ripening. This modified distribution function essentially differs from the universal Lifshitz–Slyozov (LS) solutions for several mass transfer mechanisms. Namely, its maximum lies below and is shifted to the left in comparison with the LS asymptotic distribution function. In addition, the right branch of the particle-size distribution lies above and is shifted to the right of the LS blocking point. It is shown that the initial ‘tail’ of the particle-size distribution function completely determines its behaviour at the concluding stage of Ostwald ripening. The present theory agrees well with experimental data.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
The effect of density changes on crystallization with a mushy layer
Authors: Nizovtseva Irina G. , Alexandrov Dmitri V. 
Published: April 2020

A nonlinear problem with two moving boundaries of the phase transition, which describes the process of directional crystallization in the presence of a quasi-equilibrium two-phase layer, is solved analytically for the steady-state process. The exact analytical solution in a two-phase layer is found in a parametric form (the solid phase fraction plays the role of this parameter) with allowance for possible changes in the density of the liquid phase accordingly to a linearized equation of state and arbitrary value of the solid fraction at the boundary between the two-phase and solid layers. Namely, the solute concentration, temperature, solid fraction in the mushy layer, liquid and solid phases, mushy layer thickness and its velocity are found analytically. The theory under consideration is in good agreement with experimental data. The obtained solutions have great potential applications in analysing similar processes with a two-phase layer met in materials science, geophysics, biophysics and medical physics, where the directional crystallization processes with a quasi-equilibrium mushy layer can occur.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
Thermoelectric magnetohydrodynamic control of melt pool dynamics and microstructure evolution in additive manufacturing
Authors: Kao A. , Gan T. , Tonry C. , Krastins I. , Pericleous K. 
Published: April 2020

Large thermal gradients in the melt pool from rapid heating followed by rapid cooling in metal additive manufacturing generate large thermoelectric currents. Applying an external magnetic field to the process introduces fluid flow through thermoelectric magnetohydrodynamics. Convective transport of heat and mass can then modify the melt pool dynamics and alter microstructural evolution. As a novel technique, this shows great promise in controlling the process to improve quality and mitigate defect formation. However, there is very little knowledge within the scientific community on the fundamental principles of this physical phenomenon to support practical implementation. To address this multi-physics problem that couples the key phenomena of melting/solidification, electromagnetism, hydrodynamics, heat and mass transport, the lattice Boltzmann method for fluid dynamics was combined with a purpose-built code addressing solidification modelling and electromagnetics. The theoretical study presented here investigates the hydrodynamic mechanisms introduced by the magnetic field. The resulting steady-state solutions of modified melt pool shapes and thermal fields are then used to predict the microstructure evolution using a cellular automata-based grain growth model. The results clearly demonstrate that the hydrodynamic mechanisms and, therefore, microstructure characteristics are strongly dependent on magnetic field orientation.
This article is part of the theme issue ‘Patterns in soft and biological matters'.
Stochastic phenomena in pattern formation for distributed nonlinear systems
Authors: Kolinichenko A. P. , Pisarchik A. N. , Ryashko L. B. 
Published: April 2020

We study a stochastic spatially extended population model with diffusion, where we find the coexistence of multiple non-homogeneous spatial structures in the areas of Turing instability. Transient processes of pattern generation are studied in detail. We also investigate the influence of random perturbations on the pattern formation. Scenarios of noise-induced pattern generation and stochastic transformations are studied using numerical simulations and modality analysis.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
Role of particle clusters on the rheology of magneto-polymer fluids and gels
Authors: Suarez-Fernandez William R. , Scionti Giuseppe , Duran Juan D. G. , Zubarev Andrey Yu. , Lopez-Lopez Modesto T. 
Published: April 2020

Even in the absence of cross-linking, at large enough concentration, long polymer strands have a strong influence on the rheology of aqueous systems. In this work, we show that solutions of medium molecular weight (120 000–190 000 g mol−1) alginate polymer retained a liquid-like behaviour even for concentrations as large as 20% w/v. On the contrary, solutions of alginate polymer of larger (and also polydisperse) molecular weight (up to 600 000 g mol−1) presented a gel-like behaviour already at concentrations of 7% w/v. We dispersed micrometre-sized iron particles at a concentration of 5% v/v in these solutions, which resulted in either stable magnetic fluids or gels, depending on the type of alginate polymer employed (medium or large molecular weight, respectively). These magneto-polymer composites presented a shear-thinning behaviour that allowed injection through a syringe and recovery of the original properties afterwards. More interestingly, application of a magnetic field resulted in the formation of particle clusters elongated along the field direction. The presence of these clusters intensely affected the rheology of the systems, allowing a reversible control of their stiffness. We finally developed theoretical modelling for the prediction of the magnetic-sensitive rheological properties of these magneto-polymer colloids.This article is part of the theme issue ‘Patterns in soft and biological matters'.
Targeted patterning of magnetic microparticles in a polymer composite
Authors: Borin Dmitry 
Published: April 2020

Structured and polymerized in a uniform external magnetic field, polymer composites based on magnetic soft microparticles are considered. Variations of magnetic field parameters and material composition provide a possibility of targeted micro-structural patterning of these composites. The influences of parameter variations on the resulting internal micro-structure of the low concentrated specimens are evaluated and visualized using optical microscopy and microcomputed tomography. The experimental findings are discussed in order to provide advanced possibilities of controlled patterning of soft magnetic materials. It is experimentally demonstrated that the final three-dimensional morphology of composite structure is determined mainly by the concentration of magnetic powder. The intensity of the applied magnetic field influences the rate of structuring of particles in initially viscous media and, therefore, may provide a potential opportunity to obtain non-ergodic microstructures when the matrix is polymerized before the particles have completed the structuring process. The results obtained can serve as a basis for further development of the engineering method of targeted patterning. The method is intended to obtain a material with the desired microstructure by selecting specific parameters of external stimuli and components of the composite.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
Patterns in soft and biological matters
Authors: Alexandrov Dmitri V. , Zubarev Andrey Yu. 
Published: April 2020

The issue is devoted to theoretical, computer and experimental studies of internal heterogeneous patterns, their morphology and evolution in various soft physical systems—organic and inorganic materials (e.g. alloys, polymers, cell cultures, biological tissues as well as metastable and composite materials). The importance of these studies is determined by the significant role of internal structures on the macroscopic properties and behaviour of natural and manufactured tissues and materials. Modern methods of computer modelling, statistical physics, heat and mass transfer, statistical hydrodynamics, nonlinear dynamics and experimental methods are presented and discussed. Non-equilibrium patterns which appear during macroscopic transport and hydrodynamic flow, chemical reactions, external physical fields (magnetic, electrical, thermal and hydrodynamic) and the impact of external noise on pattern evolution are the foci of this issue. Special attention is paid to pattern formation in biological systems (such as drug transport, hydrodynamic patterns in blood and pattern dynamics in protein and insulin crystals) and to the development of a scientific background for progressive methods of cancer and insult therapy (magnetic hyperthermia for cancer therapy; magnetically induced drug delivery in thrombosed blood vessels). The present issue includes works on pattern growth and their evolution in systems with complex internal structures, including stochastic dynamics, and the influence of internal structures on the external static, dynamic magnetic and mechanical properties of these systems.
This article is part of the theme issue ‘Patterns in soft and biological matters’.
Rapid, large-scale, and effective detection of COVID-19 via non-adaptive testing
Authors: Täufer Matthias 
Published: April 2020

AbstractPooling of samples can increase lab capacity when using Polymerase chain reaction (PCR) to detect diseases such as COVID-19. However, pool testing is typically performed via anadaptive testing strategywhich requires a feedback loop in the lab and at least two PCR runs to confirm positive results. This can cost precious time. We discuss a non-adaptive testing method where each sample is distributed in a prescribed manner over several pools, and which yields reliable results after one round of testing. More precisely, assuming knowledge about the overall incidence rate, we calculate explicit error bounds on the number of false positives which scale favourably with pool size and sample multiplicity. This allows for hugely streamlined PCR testing and cuts in detection times for a large-scale testing scenario. A viable consequence of this method could be real-time screening of entire communities, frontline healthcare workers and international flight passengers, for example, using the PCR machines currently in operation.