bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the encrustation of reinforced ureteral stents by computational flow dynamic simulations
Authors: Vogt Benoît 
Published: March 2023

Abstract
Purpose
In cases of extrinsic ureteral obstruction, obstruction due to encrustation is particularly detrimental to functioning of the stent. A thorough understanding of the causes that lead to stent encrustation is essential. Computational fluid dynamic (CFD) simulations may provide a reliable screening platform for investigating the interplay between flow processes and encrustation dynamics in stents.

Methods
Using a tailor-made program, we attempted to evaluate a number of reinforced ureteral stents by CFD simulations with an obstructed or unobstructed ureter and steady or discontinuous flow patterns to identify critical regions with abrupt changes in shape susceptible to stagnant flow and encrustation.

Results
For the Vortek® and Urosoft stents, the longitudinal opening of the stents confirmed the presence of critical regions. No critical region was observed for the Superglide stent. CFD simulations showed that cavities formed near the critical regions represented patently stagnant flow and were potentially susceptible to the formation of encrusting deposits. Encrustations were greater in the obstructed design than in the unobstructed design. In the model with a suddenly interrupted laminar flow, the peristaltic motion resulted in new discontinuous encrustation areas scattered throughout the entire external and internal surface of the stent.

Conclusion
The analysis of fluid dynamics through the tested stents confirmed that encrustations are possible in regions of stagnant flow and showed that stent models with the smoothest possible surface are preferable. The discontinuous flow model provided results that are closer to the findings observed in the clinic and should be more often integrated into CFD simulations.
Lineages to circuits: the developmental and evolutionary architecture of information channels into the central complex
Authors: Kandimalla Pratyush , Omoto Jaison Jiro , Hong Elizabeth J. , Hartenstein Volker 
Published: March 2023

AbstractThe representation and integration of internal and external cues is crucial for any organism to execute appropriate behaviors. In insects, a highly conserved region of the brain, the central complex (CX), functions in the representation of spatial information and behavioral states, as well as the transformation of this information into desired navigational commands. How does this relatively invariant structure enable the incorporation of information from the diversity of anatomical, behavioral, and ecological niches occupied by insects? Here, we examine the input channels to the CX in the context of their development and evolution. Insect brains develop from ~ 100 neuroblasts per hemisphere that divide systematically to form “lineages” of sister neurons, that project to their target neuropils along anatomically characteristic tracts. Overlaying this developmental tract information onto the recently generated Drosophila “hemibrain” connectome and integrating this information with the anatomical and physiological recording of neurons in other species, we observe neuropil and lineage-specific innervation, connectivity, and activity profiles in CX input channels. We posit that the proliferative potential of neuroblasts and the lineage-based architecture of information channels enable the modification of neural networks across existing, novel, and deprecated modalities in a species-specific manner, thus forming the substrate for the evolution and diversification of insect navigational circuits.
Size of the zero set of solutions of elliptic PDEs near the boundary of Lipschitz domains with small Lipschitz constant
Authors: Gallegos Josep M. 
Published: March 2023

AbstractLet$$\Omega \subset {\mathbb {R}}^d$$Ω⊂Rdbe a$$C^1$$C1domain or, more generally, a Lipschitz domain with small Lipschitz constant andA(x) be a$$d \times d$$d×duniformly elliptic, symmetric matrix with Lipschitz coefficients. Assumeuis harmonic in$$\Omega $$Ω, or with greater generalityusolves$${\text {div}}(A(x)\nabla u)=0$$div(A(x)∇u)=0in$$\Omega $$Ω, anduvanishes on$$\Sigma = \partial \Omega \cap B$$Σ=∂Ω∩Bfor some ballB. We study thedimension of the singular setofuin$$\Sigma $$Σ, in particular we show that there is a countable family of open balls$$(B_i)_i$$(Bi)isuch that$$u|_{B_i \cap \Omega }$$u|Bi∩Ωdoes not change sign and$$K \backslash \bigcup _i B_i$$K\⋃iBihas Minkowski dimension smaller than$$d-1-\epsilon $$d-1-ϵfor any compact$$K \subset \Sigma $$K⊂Σ. We also find upper bounds for the$$(d-1)$$(d-1)-dimensional Hausdorff measure of the zero set ofuin balls intersecting$$\Sigma $$Σin terms of the frequency. As a consequence, we prove a newunique continuation principle at the boundaryfor this class of functions and show that theorder of vanishingat all points of$$\Sigma $$Σis bounded except for a set of Hausdorff dimension at most$$d-1-\epsilon $$d-1-ϵ.
Critical functions and blow-up asymptotics for the fractional Brezis–Nirenberg problem in low dimension
Authors: De Nitti Nicola , König Tobias 
Published: March 2023

AbstractFor $$s \in (0,1)$$

s
∈
(
0
,
1
)

, $$N > 2s$$

N
>
2
s

, and a bounded open set $$\Omega \subset {\mathbb {R}}^N$$

Ω
⊂

R

N

with $$C^2$$

C
2

boundary, we study the fractional Brezis–Nirenberg type minimization problem of finding $$\begin{aligned} S(a):= \inf \frac{\int _{{\mathbb {R}}^N} |(-\Delta )^{s/2} u|^2 + \int _\Omega a u^2}{\left( \int _\Omega u^\frac{2N}{N-2s} \right) ^\frac{N-2s}{N}}, \end{aligned}$$

S

(
a
)

:
=
inf

∫

R

N

|

(
-
Δ
)

s
/
2

u
|

2

+

∫
Ω

a

u
2

∫
Ω

u

2
N

N
-
2
s

N
-
2
s

N

,

where the infimum is taken over all functions $$u \in H^s({\mathbb {R}}^N)$$

u
∈

H
s

(

R

N

)

that vanish outside $$\Omega $$
Ω
. The function a is assumed to be critical in the sense of Hebey and Vaugon. For low dimensions $$N \in (2\,s, 4\,s)$$

N
∈
(
2

s
,
4

s
)

, we prove that the Robin function $$\phi _a$$

ϕ
a

satisfies $$\inf _{x \in \Omega } \phi _a(x) = 0$$

inf

x
∈
Ω

ϕ
a

(
x
)

=
0

, which extends a result obtained by Druet for $$s = 1$$

s
=
1

. In dimensions $$N \in (8s/3, 4s)$$

N
∈
(
8
s
/
3
,
4
s
)

, we then study the asymptotics of the fractional Brezis–Nirenberg energy $$S(a + \varepsilon V)$$

S
(
a
+
ε
V
)

for some $$V \in L^\infty (\Omega )$$

V
∈

L
∞

(
Ω
)

as $$\varepsilon \rightarrow 0+$$

ε
→
0
+

. We give a precise description of the blow-up profile of (almost) minimizing sequences and characterize the concentration speed and the location of concentration points.
Improved Methods for Characterizing Emulsions by Low-Resolution Nuclear Magnetic Resonance via Surface Relaxation and One-Dimensional Images
Authors: Sørland Geir Humborstad , Less Simone , Alkhabbaz Sajjad , Simon Sébastien 
Published: March 2023

Abstract
The use of nuclear magnetic resonance (NMR) is an appropriate tool for studying colloids in a non-invasive manner. Droplet size distributions and one-dimensional sample profiles are readily produced to characterize an emulsion, its stability, the size distribution of the dispersed phase, and rheological behavior with respect to parameters as temperature and/or water cut. Here, we present pulsed field Grgdient NMR methods that improve the performance as compared to existing methods. In particular, the so-called multi-echo approach is introduced to enhance the signal-to-noise ratio significantly making it possible to characterize emulsions in a minute or less. Thus, any evolution that takes place in the order of just a few minutes can be monitored. In addition to the multi-echo approach, an improved method for determining the droplet size distribution from a residual emulsion, i.e., in the presence of a bulk water phase, is presented.
Exhaled patient derived aerosol dispersion during awake tracheal intubation with concurrent high flow nasal therapy
Authors: Eain Marc Mac Giolla , Nolan Kevin , Murphy Brian , McCaul Conan , MacLoughlin Ronan 
Published: March 2023

AbstractAwake Tracheal Intubation (ATI) can be performed in cases where there is potential for difficult airway management. It is considered an aerosol generating procedure and is a source of concern to healthcare workers due to the risk of transmission of airborne viral infections, such as SARS–CoV-2. At present, there is a lack of data on the quantities, size distributions and spread of aerosol particles generated during such procedures. This was a volunteer observational study which took place in an operating room of a university teaching hospital. Optical particle sizers were used to provide real time aerosol characterisation during a simulated ATI performed with concurrent high-flow nasal oxygen therapy. The particle sizers were positioned at locations that represented the different locations of clinical staff in an operating room during an ATI. The greatest concentration of patient derived aerosol particles was within 0.5–1.0 m of the subject and along their midline, 2242 #/cm3. As the distance, both radial and longitudinal, from the subject increased, the concentration decreased towards ambient levels, 36.9 ± 5.1 #/cm3. Patient derived aerosol particles < 5 µm in diameter remained entrained in the exhaled aerosol plume and fell to the floor or onto the subject. Patient derived particles > 5 µm in diameter broke away from the exhaled plume and spread radially throughout the operating room. Irrespective of distance and ventilation status, full airborne protective equipment should be worn by all staff when ATI is being performed on patients with suspected viral respiratory infections.
Precision nutrition in the context of bariatric surgery
Authors: Aguas-Ayesa Maite , Yárnoz-Esquíroz Patricia , Olazarán Laura , Gómez-Ambrosi Javier , Frühbeck Gema 
Published: March 2023

AbstractBariatric surgery (BS) is the most effective long-term treatment for severe obesity. This review summarizes the main nutritional deficiencies before and after BS, as well as current dietary and supplementation recommendations to avoid them. Likewise, we have reviewed all those aspects that in recent years have been shown to be related to postoperative weight loss (WL) and its subsequent maintenance, such as hormonal changes, dietary patterns, changes in food preference, adherence to recommendations and follow-up, genetic factors and microbiota, among others. Despite all the knowledge, nutritional deficiencies and weight regain after BS are frequent. It is essential to continue studying in this field in order to establish more precise recommendations according to the individual characteristics of patients. It is also a major objective to understand more deeply the role of the factors involved in WL and its maintenance. This will allow the development of precision treatments and nutrition for patients with obesity, optimizing their benefit after BS.
Three Eruptions Observed by Remote Sensing Instruments Onboard Solar Orbiter
Authors: Mierla Marilena , Cremades Hebe , Andretta Vincenzo , Chifu Iulia , Zhukov Andrei N. , Susino Roberto , Auchère Frédéric , Vourlidas Angelos , Talpeanu Dana-Camelia , Rodriguez Luciano , Janssens Jan , Nicula Bogdan , Aznar Cuadrado Regina , Berghmans David , Bemporad Alessandro , D’Huys Elke , Dolla Laurent , Gissot Samuel , Jerse Giovanna , Kraaikamp Emil , Long David M. , Mampaey Benjamin , Möstl Christian , Pagano Paolo , Parenti Susanna , West Matthew J. , Podladchikova Olena , Romoli Marco , Sasso Clementina , Stegen Koen , Teriaca Luca , Thompson William , Verbeeck Cis , Davies Emma 
Published: March 2023

AbstractOn February 21 and March 21 – 22, 2021, the Extreme Ultraviolet Imager (EUI) onboard Solar Orbiter observed three prominence eruptions. The eruptions were associated with coronal mass ejections (CMEs) observed by Metis, Solar Orbiter’s coronagraph. All three eruptions were also observed by instruments onboard the Solar–TErrestrial RElations Observatory (Ahead; STEREO-A), the Solar Dynamics Observatory (SDO), and the Solar and Heliospheric Observatory (SOHO). Here we present an analysis of these eruptions. We investigate their morphology, direction of propagation, and 3D properties. We demonstrate the success of applying two 3D reconstruction methods to three CMEs and their corresponding prominences observed from three perspectives and different distances from the Sun. This allows us to analyze the evolution of the events, from the erupting prominences low in the corona to the corresponding CMEs high in the corona. We also study the changes in the global magnetic field before and after the eruptions and the magnetic field configuration at the site of the eruptions using magnetic field extrapolation methods. This work highlights the importance of multi-perspective observations in studying the morphology of the erupting prominences, their source regions, and associated CMEs. The upcoming Solar Orbiter observations from higher latitudes will help to constrain this kind of study better.
Learning positioning policies for mobile manipulation operations with deep reinforcement learning
Authors: Iriondo Ander , Lazkano Elena , Ansuategi Ander , Rivera Andoni , Lluvia Iker , Tubío Carlos 
Published: March 2023

AbstractThis work focuses on the operation of picking an object on a table with a mobile manipulator. We use deep reinforcement learning (DRL) to learn a positioning policy for the robot’s base by considering the reachability constraints of the arm. This work extends our first proof-of-concept with the ultimate goal of validating the method on a real robot. Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm is used to model the base controller, and is optimised using the feedback from the MoveIt! based arm planner. The idea is to encourage the base controller to position itself in areas where the arm reaches the object. Following a simulation-to-reality approach, first we create a realistic simulation of the robotic environment in Unity, and integrate it in Robot Operating System (ROS). The drivers for both the base and the arm are also implemented. The DRL-based agent is trained in simulation and, both the robot and target poses are randomised to make the learnt base controller robust to uncertainties. We propose a task-specific setup for TD3, which includes state/action spaces, reward function and neural architectures. We compare the proposed method with the baseline work and show that the combination of TD3 and the proposed setup leads to a$$11\%$$11%higher success rate than with the baseline, with an overall success rate of$$97\%$$97%. Finally, the learnt agent is deployed and validated in the real robotic system where we obtain a promising success rate of$$75\%$$75%.
Voltammetric quantitative analysis of vildagliptin in bulk form and spiked human serum at a modified electrode
Authors: Hassanein Amira M. , Moharram Youssef I. , Sadek Mohammed E. , Khamis Abeer A. A. , Ebied Sherif E. 
Published: March 2023

AbstractThe electrochemical behavior of Vildagliptin (VILD) was studied using the cyclic voltammetric technique in an aqueous Britton–Robinson (BR) universal buffer solution of various pH levels between 4.0 and 10 at a 5% calcium-montmorillonite clay modified with carbon paste electrode surface (5% Ca-MMT/CPE). The results exhibited an irreversible anodic peak at about 1.238 V versus Ag/AgCl, KCl (3 mol L−1). The anodic peak was found to be diffusion–adsorption controlled. The possible reaction mechanism is estimated taking into consideration of the calculated electrons and protons number transferred on the electrode/electrolyte interface using the cyclic voltammetric technique. VILD was found to adsorb onto the surface of 5% Ca-MMT/CPE in a monolayer surface coverage of 3.0 × 10−12 mol cm−2. A validated square wave voltammetry (SWV) technique for VILD determination was performed. The calibration curve of VILD onto the 5% Ca-MMT/CPE surface was linear in the concentration range of 1.0–110 nmol L−1 with the mean limits of detection and quantification was 0.285 and 0.950 nmol L−1, respectively, in the bulk form. The proposed procedure for the assay of VILD in bulk form, dosage form, and spiked human serum has the advantage of being simple, rapid, sensitive, and inexpensive compared to other analytical methods. The described method showed an excellent performance for the trace determination of VILD in its formulation without interference from excipients.
Graphical abstract
“Starting from the Image”: A Tele-pathology Pre-graduate Course Aimed at Motivating Medical Students
Authors: Lazari Evgenia-Charikleia , Lazaris Andreas C. , Manou Evangelia , Agrogiannis Georgios , Nastos Constantinos , Pikoulis Emmanouil , Thomopoulou Georgia-Eleni 
Published: March 2023

AbstractIn the tele-course entitled “Starting from the image”, medical students are confronted with practical tasks in relevant professional contexts. Initially, a macroscopic or microscopic image of a patient case is presented to learners who then receive relevant information on the patient’s history, clinical findings, and other laboratory tests. A pathologist actively discusses the pathological findings; then, a clinician explains their implications for the patient’s individualized treatment and prognosis. In this way, pathology’s interaction with other medical specialties is highlighted. Students declared that through these simulated professional practice experiences, they strengthened their decision-making skills. Educators should consider upgrading from information-based teaching to practice-focused instruction.
Does neck flexion improve performance? Effects on reaction time depend on whether responses are expected
Authors: Baer Jason L. , Cohen Rajal G. 
Published: March 2023

AbstractThis research investigates the limitations of the apparent paradox in which neck flexion, which is associated with poor inhibition and neck pain, seems to facilitate performance in some tasks. We compared the effect of a flexed neck on performance in a reaction time and go-nogo task using a novel method of fixing neck posture. We hypothesize that using a flexed neck posture speeds response time for tasks with high prepotency (when participants are biased toward responding), but not for tasks with low prepotency (when participants are more likely to withhold a response). Previous findings demonstrated the effect of neck flexion on reaction time with a harness. In this study, participants complete both simple reaction time and go-nogo tasks with neck angles fixed in neutral or forward positions with tape. We found that simple reaction times were 10 ms faster in the forward neck position than in neutral; this facilitation was not seen in the go-nogo task. We conclude that using tape to induce a flexed neck posture facilitates reaction time during tasks that always require a response and does not affect reaction time on a task which may require withholding a response.
Insights into the mechanisms underlying the biodegradation of phenanthrene in biochar-amended soil: from bioavailability to soil microbial communities
Authors: Zhang Meng , Luo Yaqi , Zhu Yitao , Zhang Haiyun , Wang Xilong , Li Wei , Li Pingping , Han Jiangang 
Published: March 2023

AbstractThe dynamic effect of biochar amendment in contaminated soil on the bioavailability of polycyclic aromatic hydrocarbons (PAHs) and microbial communities and how it comprehensively affects PAH biodegradation remain unclear. This study investigated the effects of wheat straw-derived biochars obtained at 300 and 500 °C at different amendment levels (0.03% and 0.3%) on the mineralization kinetics of phenanthrene with different initial concentrations (2 and 20 mg kg−1) in soil by indigenous microorganisms. The results revealed that the addition of biochar inhibited both the rates and extents of mineralization in low-concentration phenanthrene-contaminated soil (PLS) by 38.9–78.3% and 23.9–53.6%, respectively. This was because biochar amendment in the PLS greatly reduced the bioavailable fraction of phenanthrene for degradation owing to its strong sorption and also decreased that to specific degrading bacterial genera, which hindered their growth and reduced their abundances by 1.37–36.6%. However, biochar addition into the soil contaminated with high concentrations of phenanthrene (PHS) resulted in its effective mineralization and enhanced mineralization rates and extents at high amendment levels by 32.4–86.7% and 32.0–44.7%, respectively. This was because biochar amendment in the PHS significantly promoted the abundances of the total bacterial communities (29.9–80.4%) and potential degrading genera (1.89–25.9%) by providing nutrients and stimulated the specific PAH-degradative nidA gene abundance by 1–2 times. These findings will guide the use of biochar to remediate soils with different PAH pollution levels based on the two roles that they play (i.e., immobilizing PAHs or facilitating PAH degradation).
Graphical Abstract
Tools and Techniques for Teaching and Research in Network Design and Simulation
Authors: Rahman Muhammad Azizur , Pakstas Algirdas 
Published: March 2023

AbstractComputer networking is taught for some time at universities. A network is a complex mix of applications, communications protocols and link technologies, traffic flows and routing algorithms. Teaching the networking concept, the network design process is a challenging task, requiring designers to balance user performance expectations with costs and capacities. One of the obvious approaches employed to deal with its complexity is through the use of modelling and simulation techniques. This paper examines three best educational tools that can be used in the Computer Networking course at Cardiff Metropolitan University or any University for educational purpose. The paper demonstrates that a successful teaching programme needs to combine a range of teaching tools to achieve its aims. Analysing various aspects of the course provides evaluation of the overall success of the tools. Many network design and simulation tools have been studied. Based on our research and experiment, the best educational tools were selected that could be used for the purpose of teaching in the area of computer communications networks. The wide area network modelling tool Delite, the network simulator ns-3, the topology generation tool Brite can be used together to teach students the networking concepts. These tools can not only help students to understand computer network principles but also improve their network practical skills. Currently there are various tools available that are created by different companies and groups of researchers in academia and that are intended for use as practical and/or educational tools for network design including security issues. To make this task easy, different users, researchers and companies have developed different network modelling and simulation (MS) tools. Very often, such tools are addressing different issues in the network design process which are complementary to each other. It would be useful for learning and improving the network design process by allowing the use of a variety of tools.