bluuebunny/crossref_metadata_2025 huggingface dataset:
Robocasting of ordered mesoporous silica‐based monoliths: Rheological, textural, and mechanical characterization
Authors: Dal Molin Emiliano S. , Henning Laura M. , Müller Julian T. , Smales Glen J. , Pauw Brian R. , Bekheet Maged F. , Gurlo Aleksander , Simon Ulla
Published: September 2023

Hierarchically porous, high‐surface‐area silica materials are excellent candidates for multiple applications like catalysis and environmental remediation. Shaping these materials with additive manufacturing (AM) techniques, like robocasting, could enable their use with the benefit of on‐demand, customized shaping and maximizing performance. Herein, ordered mesoporous silica COK‐12 slurries were robocasted into monoliths, containing different ratios of uncalcined COK‐12 and sodium bentonite (0–25 wt.%). The rheology of the mixed slurries is characterized by lower flow indexes (0.69 vs. 0.32) and higher yield stresses (96 vs. 259 Pa) compared to pure COK‐12 ones. Monoliths were printed in woodpile structures and calcined at 600°C. Micro‐CT measurements showed a linear shrinkage of 25% after calcination. Mechanical characterization showed increased uniaxial strength (0.20 ± 0.07 to 1.0 ± 0.3 MPa) with increasing binder/solids ratio from 13 to 25%. The amorphous, mesoporous structure of COK‐12 was retained. The structures exhibited open porosities of 52 ± 4% and showed higher specific mesopore volumes, and increased average mesopore size (6 vs. 8 nm) compared to COK‐12. Small‐angle x‐ray scattering analysis revealed an increased lattice parameter (10.3 vs. 11.0 nm) and reduced wall thickness (3.1 nm vs. 4.1 nm) of the COK‐12 in the monoliths. These properties indicate suitability for their application as porous supports and adsorbents.
Incorporating uncertainty in stress‐strain data acquisition: extended model‐free data‐driven identification
Authors: Zschocke Selina , Graf Wolfgang , Kaliske Michael
Published: September 2023

Based on the increasing ability to collect and store large amounts of data and information, data‐driven methods have recently gained importance in the context of computational mechanics. Compared to the traditional approach of defining a suitable constitutive model and fit the parameters to experimental data, these methods aim to capture complex material behavior without the assumption of a certain material formulation. Distinguished are model‐based data‐driven methods, leading to an approximation of the constitutive material description for example, by neural networks, and model‐free data‐driven methods. The approach of data‐driven computational mechanics (DDCM), introduced by Kirchdoerfer and Ortiz (2016), enables to circumvent any material modeling step by directly incorporating material data into the structural analysis. A basic prerequisite for both types of data‐driven methods is a large amount of data representing the material behavior, in solid mechanics consisting of stresses and strains. Obtaining these databases numerically by multiscale approaches is computationally expensive and requires the definition of lower scale models. In case of an experimental characterization, constitutive descriptions are generally required to compute the stress states corresponding to displacement fields, for example, identified by full‐field measurement techniques, such as digital image correlation (DIC). The method of data‐driven identification (DDI), introduced in Leygue et al. (2018) based on the principles of DDCM, enables the determination of detailed information about the constitutive behavior based on displacement fields and applied boundary conditions without a specific material model. Stresses corresponding to given strains are identified by iteratively clustering and enforcing equilibrium. The algorithm has shown to be applicable to synthetic as well as real data taking linear and non‐linear material behavior into account. Generalized polymorphic uncertainty models, resulting as a combination of aleatoric and epistemic uncertainty models, are utilized to take variability, imprecision, inaccuracy and incompleteness of data into account. The consideration of uncertain material properties by data‐driven simulation approaches leads to the requirement of data sets representing uncertain material behavior. In this contribution, different sources of uncertainty occurring within DDI of stress‐strain relations are addressed and an efficient method for the identification of data sets representing uncertain material behavior based on the concept of DDI is proposed. In order to demonstrate the developed methods, numerical examples are carried out.
Catalog of Dynamical System Models with Semantic Metadata
Authors: Fiedler Julius , Knoll Carsten
Published: September 2023

This contribution presents the concept and implementation of a catalog (i.e., a structured collection) of dynamical system models, relevant to control theory. The key features of the catalog are: (a) a combination of human‐readable model documentation with executable code; (b) semantic metadata for each model plus a web platform to provide SPARQL search interface; and (c) model data and supporting software based on open source repositories and open for extension and improvement.
Convex reconstruction of moving particles with inexact motion model
Authors: Hahn Bernadette , Wirth Benedikt
Published: September 2023

We propose a novel convex optimization problem for the reconstruction of temporally moving nonnegative point sources or particles. As in previously developed approaches from the literature, we base our reconstruction on a linear motion model in which particles move at constant d‐dimensional velocity. However, in contrast to existing approaches we allow a deviation from the exact linear motion, thereby accounting for the modelling error inherent in that motion model. The deviation is measured with the help of Wasserstein distances and is constrained not to exceed a freely selectable bound which represents the model inexactness. We show well‐posedness and first numerical results for the model.
Modeling the material behavior of heterogeneous materials considering a two‐scale FE–FFT‐based simulation framework
Authors: Schmidt Annika , Gierden Christian , Waimann Johanna , Reese Stefanie
Published: September 2023

In various engineering applications, components subjected to high mechanical or multi‐physical loads such as thermal, thermo‐mechanical, or electro‐thermal loads are predominantly made of metals or composites. These materials are characterized by polycrystalline or multi‐phase microstructures which determine the overall material response. However, since the microscopic material behavior is directly related to the distribution, size, and morphology of the individual grains or phase constituents, precise predictions of the macroscopic material response require simulations of the microstructural behavior. Hence, this work considers a two‐scale finite element (FE) and fast Fourier transform (FFT)‐based simulation framework, which is an efficient alternative to the classical method for the simulation of periodic unit cells. Assuming scale separation, the macroscopic and microscopic boundary value problems are first solved individually and subsequently linked by performing a scale transition in terms of averaging the macroscopic quantities over the corresponding local fields. While the macroscopic solution is computed by means of the finite element method, the microscopic boundary value problem, which is embedded as a periodic unit cell in each macroscopic integration point, is solved using an FFT‐based simulation method. In general, these microscopic simulations allow to model grain‐scale phenomena such as martensitic phase transformation or plastic deformation caused by dislocation glide which can be observed in polycrystalline materials. In this work, we present a two‐scale FE–FFT‐based model to capture the martensitic phase transformations in shape memory alloys. In order to demonstrate the applicability of the model, a numerical example is given.
Coupled clustering strategies for hierarchical matrix preconditioners in saddle point problems
Authors: Grams Jonas , Le Borne Sabine
Published: September 2023

Fluid flow problems can be modeled by the Navier–Stokes or, after linearization, by the Oseen equations. Their discretization results in discrete saddle point problems. These systems of equations are typically very large and need to be solved iteratively. Standard (block‐) preconditioning techniques for saddle point problems rely on an approximation of the Schur complement. Such an approximation can be obtained by a hierarchical (‐) matrix LU‐decomposition, which first approximates the Schur complement explicitly. The computational complexity of this computation depends, among other things, on the hierarchical block structure of the involved matrices. However, widely used techniques do not consider the connection between the discretization grids for the velocity field and the pressure, respectively. Here, we present a hierarchical block structure for the finite element discretization of the gradient operator that is improved by considering the connection between the two involved grids. Numerical results imply that the improved block structure allows for a faster computation of the Schur complement, which is the bottleneck for the set‐up of the ‐matrix LU‐decomposition.
Adaptive MOR techniques for non‐linear FE simulations of unit cells
Authors: Özmen Yasemin , Niekamp Rainer , Nigro Paulo S. B. , Schröder Jörg
Published: September 2023

This work shows an adaptive Model Order Reduction (MOR) scheme for the computation of unit cells with non‐linear material behavior. A reduction of dimensionality and computational cost is achieved by projecting the high‐fidelity system of equations (SOE) from the full vector space to a lower dimensional subspace. An adaptive algorithm updates the projection operator, which is initially gained from a Proper Orthogonal Decomposition (POD), to ensure convergence and optimal size control of the reduced problem. Numerical examples show a comparison between the discretization of full displacements and fluctuations of a hexagonal unit cell, which show the independence of the MOR basis from the macroscopic displacements.
Numerical implementation of tension–compression asymmetry in a gradient‐extended two‐surface damage–plasticity model
Authors: Zhang Jian , Brepols Tim , Reese Stefanie
Published: September 2023

Based on the spectral decomposition of the strain tensor, the tension‐compression asymmetry (TCA) in a gradient‐extended two‐surface damage‐plasticity model is considered in this study. More specifically, the gradient extension is applied in the current model as a suitable damage regularization technique to prevent pathological mesh dependence issues. Furthermore, plasticity and damage are treated as distinct but strongly coupled dissipative mechanisms by using two different types of damage and yield criteria as well as the related loading/unloading conditions, respectively. Finally, a specific material parameter is adopted to control the degree of TCA which results in a unique damage evolution in compression.
A variational approach for temporal multiscale problems and its application to adaptivity and optimization
Authors: Dominguez Dayron , Lautsch Leopold , Richter Thomas
Published: September 2023

We discuss a computational multiscale method for the efficient simulation and optimization of differential equations with multiple scales in time. The approach is based on isolating the influences of the fast scale by a local periodic‐in‐time assumption that allows for time‐stepping of the averaged slow scale with very large step sizes. For this approach we develop a variational formulation that gives easy access to the methodology of goal‐oriented error estimation and adaptivity as well as gradient based optimization.
Transient response of pavement structures under moving wheel loads using the ALE methodology
Authors: Anantheswar Atul , Wollny Ines , Kaliske Michael
Published: September 2023

The dynamic response of long structures (e.g., pavements) subjected to moving loads is generally difficult to simulate using conventional methods like the finite element method in the Lagrangian setting. This is because the entire length of the structure in the path of the moving load would need to be discretized, and in turn would require large meshes. Additionally, if improvement in quality of results through the use of finer mesh sizes is sought, the entire region of the mesh in the load path would require refinement. As a direct result, long simulation run‐times can be expected when using conventional methods. To overcome these drawbacks, and improve the efficiency of the finite element simulations, the Arbitrary Lagrangian Eulerian (ALE) approach can be used to simulate pavement structures, provided longitudinal homogeneity is assumed. This contribution uses an extension of the quasi‐static ALE framework to the transient domain, enabling the study of the dynamic response of pavement structures subjected to moving loads. In this work, some case studies are considered to highlight the capabilities of this dynamic ALE framework.
Investigation on the short‐term outcome and prognostic impact of predisposition, and precipitants in inpatients with chronic liver disease from Chinese AcuTe on CHronic LIver FailurE (CATCH‐LIFE) cohorts
Authors: Zhang Yan , Tan Wenting , Wang Xiaobo , Zheng Xin , Huang Yan , Li Beiling , Meng Zhongji , Gao Yanhang , Qian Zhiping , Liu Feng , Lu Xiaobo , Shang Jia , Zheng Yubao , Zhang Weituo , Yin Shan , Gu Wenyi , Wang Tongyu , Wei Jianyi , Shen Zixuan , Deng Guohong , Zhou Yi , Hou Yixin , Zhang Qun , Xiong Shue , Liu Jing , Long Liyuan , Chen Ruochan , Chen Jinjun , Jiang Xiuhua , Luo Sen , Chen Yuanyuan , Jiang Chang , Zhao Jinming , Ji Liujuan , Mei Xue , Li Jing , Li Tao , Zheng Rongjiong , Zhou Xinyi , Ren Haotang , Shi Yu , Li Hai ,   for the CATCH‐LIFE Study Investigators of Chinese (Acute‐on) Chronic Liver Failure (CLIF) Consortium (Ch‐CLIF.C)
Published: September 2023

Aim

The study aimed to investigate the short‐term outcomes of hospitalized patients with chronic liver disease (CLDs) and assess the prognostic impact of predisposition and precipitants, which currently remains unclear.

Methods

The study included 3970 hospitalized patients with CLDs from two prospective longitudinal multicenter studies (NCT02457637 and NCT03641872) conducted in highly endemic hepatitis B virus (HBV) areas. Competing risk analysis was used to evaluate the effect of predispositions, including the etiology and severity of CLDs and precipitants; on sequential 28, 90, and 365‐day liver transplantation (LT)‐free mortality.

Results

Among all enrolled patients, 76.8% of adverse outcomes (including death and LT) within one year occurred within 90 days. Compared with alcoholic etiology, the association of HBV etiology with poorer outcomes was remarkably on the 28th day (hazard ratio [HR], 1.81; 95% confidence interval [CI], 1.07–3.06; p = 0.026); however, and diminished or became insignificant at 90 days and 365 days. Cirrhosis increased the adjusted risk for 365‐day (HR, 1.50; CI, 1.13–1.99; p = 0.004) LT‐free mortality when compared with noncirrhosis. In patients with cirrhosis, prior decompensation (PD) independently increased the adjusted risk of 365‐day LT‐free mortality by 1.25‐fold (p = 0.021); however, it did not increase the risk for 90‐day mortality. Neither the category nor the number of precipitants influenced the adjusted risk of 28 or 90‐day LT‐free mortality.

Conclusions

The 90‐day outcome should be considered a significant endpoint for evaluating the short‐term prognosis of hospitalized patients with CLD. Predisposing factors, other than etiology, mainly affected the delayed (365‐day) outcome. Timely effective therapy for CLD etiology, especially antiviral treatments for HBV, and post‐discharge long‐term surveillance monitoring in cirrhotic patients undergoing PD are suggested to enhance disease management and reduce mortality.
Impact of the COVID‐19 pandemic on care disruptions, outcomes, and costs in patients receiving pulmonary arterial hypertension‐specific therapy in the United States of America: An observational study
Authors: George Marjorie Patricia , Germack Hayley D. , Goyal Amit , Ward Charlotte , Studer Sean , Panjabi Sumeet
Published: September 2023

Regular expert follow‐up, risk assessment, and early therapeutic intervention minimize worsening of pulmonary arterial hypertension (PAH). COVID‐19 lockdown measures were challenging for chronic disease management. This retrospective, longitudinal analysis used US claims data (January 12, 2016 to September 11, 2021) for patients treated with PAH‐specific medication to compare in‐person outpatient and specialist visits, telemedicine visits, and PAH‐related tests during 6‐month assessment periods pre‐ and immediately post‐COVID‐19. Hospitalizations, costs, and outcomes were compared in patients with and without care disruptions (no in‐person or telemedicine outpatient visits in immediate post‐COVID‐19 period). Patients in the immediate post‐COVID‐19 (N = 599) versus the pre‐COVID‐19 period (N = 598) had fewer in‐person outpatient visits (mean 1.27 vs. 2.12) and in‐person specialist visits (pulmonologist, 22.9% vs. 37.0% of patients; cardiologist, 27.5% vs. 33.8%); and more telemedicine visits (mean 0.45 vs. 0.02). In the immediate post‐COVID‐19 period, patients were less likely to have a PAH‐related test versus the pre‐COVID‐19 period (incidence rate ratio: 0.700; 95% confidence interval: 0.615−0.797), including electrocardiograms (41.7% vs. 54.2%) and 6‐minute walk distance tests (16.2% vs. 24.9%). In the immediate post‐COVID‐19 period, 48 patients had care disruptions and, in the following year, required more hospital days than those without care disruptions (N = 240) (median 10 vs. 5 days in total) and had higher overall hospitalization costs (median US$34,755 vs. US$20,090). Our findings support the need for minimizing care disruptions to potentially avoid incremental post‐disruption healthcare utilization and costs among patients with serious chronic diseases such as PAH.
Peak steps: Capacity for activity improves after adding approved therapy in pulmonary arterial hypertension
Authors: Lachant Daniel , Light Allison , Lachant Michael , Annis Jeffrey , Hemnes Anna , Brittain Evan , White R. James
Published: September 2023

Pulmonary arterial hypertension (PAH) patients have low activity. Activity intensity or duration could be a measure of clinical status or improvement. We aimed to determine whether standard or novel actigraphy measures could detect increases in activity after adding therapy. This was a prospective, single‐center observational study evaluating activity after adding therapy in Group 1 PAH; we also report a validation cohort. For our study, two different accelerometers were used, a wrist (ActiGraph) and chest (MC10) device. Patients were analyzed in two groups, Treatment Intensification (TI, adding therapy) or Stable. Both groups had baseline monitoring periods of 7 days; the TI group had follow‐up at 3 months, while Stables had follow‐up within 4 weeks to assess stability. Activity time and steps were reported from both devices' proprietary algorithms. In ActiGraph only, steps in 1‐min intervals throughout the day were ranked (not necessarily contiguous). Average values for each week were calculated and compared using nonparametric testing. Thirty patients had paired data (11 Stable and 19 TI). There was no between‐group difference at baseline; we did not observe therapy‐associated changes on average daily steps or activity time/intensity. The top 5 min of steps (capacity) increased after adding therapy; there was no difference in the stable group. This key finding was validated in a previously reported randomized trial studying a behavioral intervention to increase exercise. Total daily activity metrics are influenced by both disease and non‐disease factors, making therapy‐associated change difficult to detect. Peak minute steps were a treatment‐responsive marker in both a pharmacologic and training intervention.
Man versus machine: Automatic pedicle screw planning using registration‐based techniques compared with manual screw planning for thoracolumbar fusion surgeries
Authors: Bertram Ulf , Köveshazi Istvan , Michaelis Monika , Weidert Simon , Schmidt Tobias Philip , Blume Christian , Zastrow Felix Swamy v. , Müller Christian‐Andreas , Szabo Szilard
Published: September 2023

Objective

This study evaluates the precision of a commercially available spine planning software in automatic spine labelling and screw‐trajectory proposal.

Methods

The software uses automatic segmentation and registration of the vertebra to generate screw proposals. 877 trajectories were compared. Four neurosurgeons assessed suggested trajectories, performed corrections, and manually planned pedicle screws. Additionally, automatic identification/labelling was evaluated.

Results

Automatic labelling was correct in 89% of the cases. 92.9% of automatically planned trajectories were in accordance with G&R grade A + B. Automatic mode reduced the time spent planning screw trajectories by 7 s per screw to 20 s per vertebra. Manual mode yielded differences in screw‐length between surgeons (largest distribution peak: 5 mm), automatic in contrast at 0 mm. The size of suggested pedicle screws was significantly smaller (largest peaks in difference between 0.5 and 3 mm) than the surgeon's choice.

Conclusion

Automatic identification of vertebrae works in most cases and suggested pedicle screw trajectories are acceptable. So far, it does not substitute for an experienced surgeon's assessment.
South African extreme weather during the 1877–1878 El Niño
Authors: Brugnara Yuri , Brönnimann Stefan , Grab Stefan , Steinkopf Jessica , Burgdorf Angela‐Maria , Wilkinson Clive , Allan Rob
Published: September 2023

The El Niño event of 1877–1878 was one of the strongest during the last 150 years and had worldwide impacts, bringing widespread severe droughts, but also unusually wet conditions to some regions. We focus on the effects that this event had on precipitation in South Africa, taking advantage of newly rescued instrumental data, as well as documentary sources. Through the assimilation of the new data into an existing reanalysis, we could improve the synoptic reconstruction of specific weather events. However, much remains to be done in order to achieve a good and consistent reconstruction quality for the region.
Peristaltic transport of a Ree‐Eyring fluid with non‐uniform complaint channel: An analysis through varying conditions
Authors: Li Shuguang , Rajashekhar C. , Nisar K. S. , Mebarek‐Oudina Fateh , Vaidya H. , Khan M. Ijaz , Prasad K. V. , Balachandra H. , Manjunatha G.
Published: September 2023

The peristaltic mechanism of a non‐Newtonian Ree‐Eyring liquid in the presence of variable liquid properties and heat transfer is an integral component of technology and healthcare systems. This study aims to investigate and analyze this mechanism, taking into account the influence of wall properties and variable liquid properties. The long wavelength and Low Reynolds approximations are used in the model designed for this purpose. A regular perturbation technique solves the resulting nonlinear partial differential equations with the proper non‐dimensional parameters. The magnetic field's influence is crucial in determining the fluid flow behavior, whereas the variable liquid properties significantly affect the temperature profiles. This research contributes to an improved understanding of peristalsis in the context of Ree‐Eyring liquids and has potential implications for several technical and medical applications.
Analysis of entropy generation and Joule heating effects for MHD peristaltic flow over an asymmetric channel with mixed convective conditions
Authors: Tanveer Arooj , Ashraf Muhammad Bilal , Zaib‐Un‐Nisa
Published: September 2023

The investigation of entropy generation in peristaltic flow in an asymmetric channel under mixed convective conditions is a contribution to the body of literature. The used transport model includes appropriate boundary conditions along with continuity, momentum, energy, and concentration equations. Under the presumptions of a long wavelength and a low Reynolds number, the analysis is carried out. The analysis takes into account important elements including Joule heating, magnetohydrodynamics (MHD), and heat and mass transmission. An approach using BVP4C is used to analyze the governing system. The research adds to the body of knowledge in the subject by revealing important details about the complex interactions between these variables and how they affect peristaltic flow's creation of entropy. The originality of this work resides in its thorough examination of numerous crucial elements, including MHD, Joule heating, and mass and heat transport. The originality of this research is further enhanced by the analysis of the impacts of various parameters on velocity, temperature, concentration, pressure gradient, and streamlines. This study provides a novel viewpoint and a deeper knowledge of the entropy generation phenomenon in peristaltic flow, opening the door for potential applications in numerous disciplines including fluid dynamics, biomedical engineering, and transport processes.
Upregulation of HDAC9 in hippocampal neurons mediates depression-like behaviours by inhibiting ANXA2 degradation
Authors: Dai Yunjian , Wei Taofeng , Huang Yuwen , Bei Yun , Lin Haoran , Shen Zexu , Yu Lingyan , Yang Mingdong , Xu Huimin , He Wei , Lin Zheng , Dai Haibin
Published: September 2023

Major depressive disorder (MDD) is a pervasive and devastating mental disease. Broad spectrum histone deacetylase (HDAC) inhibitors are considered to have potential for the treatment of depressive phenotype in mice. However, due to its non-specific inhibition, it has extensive side effects and can not be used in clinical treatment of MDD. Therefore, finding specific HDAC subtypes that play a major role in the etiology of MDD is the key to develop corresponding specific inhibitors as antidepressants in the future. Copy number variation in HDAC9 gene is thought to be associated with the etiology of some psychiatric disorders. Herein, we found that HDAC9 was highly expressed in the hippocampus of chronic restraint stress (CRS) mouse model of depression. Upregulation of HDAC9 expression in hippocampal neurons of mice induced depression-like phenotypes, including anhedonia, helplessness, decreased dendritic spine density, and neuronal hypoexcitability. Moreover, knockdown or knockout of HDAC9 in hippocampal neurons alleviated depression-like phenotypes caused by chronic restraint stress (CRS) in WT mice. Importantly, using immunoprecipitation–mass spectrometry (IP–MS), we further found that Annexin A2 (ANXA2) was coupled to and deacetylated by HDAC9. This coupling resulted in the inhibition of ubiquitinated ANXA2 degradation and then mediates depression-like behavior. Overall, we discovered a previously unrecognized role for HDAC9 in hippocampal neurons in the pathogenesis of depression, indicating that inhibition of HDAC9 might be a promising clinical strategy for the treatment of depressive disorders.
Type of Local von Neumann Algebras in Abelian Quantum Double Models
Authors: Ogata Yoshiko
Published: September 2023

We show that the local von Neumann algebra on convex areas of the frustration-free ground state of abelian quantum double models is of type $$II_\infty $$

I

I
∞

.
Element Concentrations in Muscle and Liver Tissue of Two Eel Species from the Incomati River, Mozambique
Authors: Erasmus Johannes H. , Herselman Shaun , Wepener Victor
Published: September 2023

Many rural communities in Mozambique get their income from fisheries, as well as consume fish as an inexpensive source of protein. In Mozambique, fish consumption from small-scale fisheries dependent families can range between 60 and 150 kg/person/year. Anguillid eels have important social value to vulnerable local communities in the Incomati Basin. Anguillid eels in the lower Incomati Basin are targeted for consumption, as well as cultural rituals by traditional healers. The aim of the present study was to determine trace element concentrations in environmental matrices, bioaccumulation patterns in muscle and liver tissue of two Anguilla species (Anguilla mossambica and Anguilla marmorata), as well as the chronic health risk these elements pose to regular consumers in the lower Incomati River. Bioaccumulation of elements from the water had a higher effect on both muscle and liver tissues, where only the bioaccumulation of Pb in the sediments played a major role. From the human health risk assessment, Hg pose non-carcinogenic risk, whereas As, Cr, and Ni pose carcinogenic risks.
Modeling of blood flow in the framework of micropolar theory
Authors: Vilchevskaya Anastasiya E. , Vilchevskaya Elena N. , Müller Wolfgang H. , Eremeyev Victor A.
Published: September 2023

In this paper, we study the blood flow through blood vessels of various radii (including the case of variable cross section as well as modeling the blood flow through venae and arteries). Two approaches are discussed in order to mimic the dependence of blood viscosity on red blood cells aggregation, which changes with the shear rate and position inside the vessel: Two microstructural parameters together with empirical constitutive equations as a characteristic of aggregation are proposed, namely the microinertia as well as the volume fraction of blood particles (erythrocytes, platelets and leukocytes). Consequently, the Navier–Stokes system of equations for an incompressible fluid is supplemented by a constitutive equation for the moment of inertia in one case and for the volume fraction in another. The problems are solved numerically by the finite volume method for vessels of various geometries in spatial description. A comparison with experimental data for a narrow capillary shows the efficiency of the proposed constitutive equations for describing blood flow. Also, velocity profiles are obtained on the basis of compiled empirical formula for various sections of a blood vessel of variable radius. In addition, the flow through vessels of the human circulatory system, such as the inferior vena cava and the carotid artery, are studied.
Is day-case surgery feasible for laser endoscopic enucleation of the prostate? A systematic review
Authors: Yilmaz Mehmet , Karaaslan Mustafa , Polat Muhammed Emin , Tonyali Senol , Aybal Halil Çağrı , Şirin Mehmet Emin , Toprak Tuncay , Tunç Lütfi , Gratzke Christian , Miernik Arkadiusz
Published: September 2023

Purpose

Laser endoscopic enucleation of the prostate (EEP) for benign prostatic obstruction has become increasingly prevalent worldwide. Considering the medical cost-savings and concomitantly fewer nosocomial infections, the feasibility of same-day postoperative discharge of patients who have undergone laser EEP in terms of its safety and effectiveness has become a subject matter of growing interest. We aimed to review those studies focussing on day-case surgery (DCS) in patients undergoing laser EEP.

Methods

A systematic search was conducted using PubMed-MEDLINE and Web of Science databases until October 2022 with the following search terms: “same day discharge AND laser enucleation of the prostate”, “day-case AND laser enucleation of the prostate”, “same day surgery AND laser enucleation of the prostate” and “one day surgery AND laser enucleation of the prostate” by combining PICO (population, intervention, comparison, outcome) terms. We identified 15 eligible studies.

Results

While 14 of the studies focussed on holmium laser EEP, one focused on thulium laser vapoenucleation of the prostate. We observed an improvement in functional parameters in all studies we reviewed, and DCS success and readmission rates ranged between 35.3–100% and 0–17.8%, respectively. The complication rates varied between 0 and 36.7%, most of the complicatons were Clavien-Dindo (CD) I and II. CD ≥ III complications did not significantly differ between same day discharge (SDD) and non-SDD groups in the studies.

Conclusion

Laser EEP is feasible and promising DCS treatment option delivering improved functional parameters compared to baseline values, and lower perioperative complication and readmission rates in certain patients.
The genome of Anoplarchus purpurescens (Stichaeidae) reflects its carnivorous diet
Authors: Le Ninh , Heras Joseph , Herrera Michelle J. , German Donovan P. , Crummett Lisa T.
Published: September 2023

Digestion is driven by digestive enzymes and digestive enzyme gene copy number can provide insights on the genomic underpinnings of dietary specialization. The “Adaptive Modulation Hypothesis” (AMH) proposes that digestive enzyme activity, which increases with increased gene copy number, should correlate with substrate quantity in the diet. To test the AMH and reveal some of the genetics of herbivory vs carnivory, we sequenced, assembled, and annotated the genome of Anoplarchus purpurescens, a carnivorous prickleback fish in the family Stichaeidae, and compared the gene copy number for key digestive enzymes to that of Cebidichthys violaceus, a herbivorous fish from the same family. A highly contiguous genome assembly of high quality (N50 = 10.6 Mb) was produced for A. purpurescens, using combined long-read and short-read technology, with an estimated 33,842 protein-coding genes. The digestive enzymes that we examined include pancreatic α-amylase, carboxyl ester lipase, alanyl aminopeptidase, trypsin, and chymotrypsin. Anoplarchus purpurescens had fewer copies of pancreatic α-amylase (carbohydrate digestion) than C. violaceus (1 vs. 3 copies). Moreover, A. purpurescens had one fewer copy of carboxyl ester lipase (plant lipid digestion) than C. violaceus (4 vs. 5). We observed an expansion in copy number for several protein digestion genes in A. purpurescens compared to C. violaceus, including trypsin (5 vs. 3) and total aminopeptidases (6 vs. 5). Collectively, these genomic differences coincide with measured digestive enzyme activities (phenotypes) in the two species and they support the AMH. Moreover, this genomic resource is now available to better understand fish biology and dietary specialization.
Surgical treatment of fracture sequelae of the proximal humerus according to a pathology-based modification of the Boileau classification results in improved clinical outcome after shoulder arthroplasty
Authors: Kimmeyer Michael , Schmalzl Jonas , Schmidt Evelin , Graf Annika , Rentschler Verena , Gerhardt Christian , Lehmann Lars-Johannes
Published: September 2023

Background

Fracture sequelae of the proximal humerus were classified by Boileau into four types. Since there are pathomorphological differences and specific characteristics within the four types, we have developed a subclassification. For elderly patients, shoulder arthroplasty is mostly recommended. Based on the available literature and clinical trial results, a subclassification could be created that suggests a specific therapy for each subgroup. The aim of this study was to evaluate the endoprosthetic therapy according to the proposed subclassification and to provide an overview of the clinical and radiological results after endoprosthetic treatment of proximal humerus fracture sequelae.

Methods

Patients with fracture sequelae of the proximal humerus who underwent arthroplasty according to the suggestion of the subclassification were included. Minimum time to follow-up was twelve months. General condition and several specific shoulder scores as the Constant–Murley Score (CS) were recorded at the follow-up examination. Complication and revision rates were analyzed.

Results

In total, 59 patients (72.6 ± 10.0 years, 47 females, 12 males) were included. Mean follow-up time was 31.3 ± 17.0 months. Reverse shoulder arthroplasty was performed in 49 patients and anatomic shoulder arthroplasty was performed in ten patients. The CS increased by 47.3 points from preoperative (15.0) to postoperative (62.3). Good or very good clinical results were seen in 61% of the patients. Complications were observed in twelve (20%) patients and revision surgery was performed in nine (15%) patients.

Conclusion

Due to of the variety of fracture sequelae of the proximal humerus, a modification of the Boileau classification seems necessary. This study shows that endoprosthetic treatment for fracture sequelae can significantly improve the shoulder function in elderly patients. Good clinical results can be achieved with a comparatively low revision rate following the treatment suggestions of the proposed subclassification of the Boileau classification.

Level of evidence IV

Case series.
Serum metabolomics study of narcolepsy type 1 based on ultra-performance liquid chromatography–tandem mass spectrometry
Authors: Zhan Qingqing , Wang Lili , Liu Nan , Yuan Yuqing , Deng Liying , Ding Yongmin , Wang Fen , Zhou Jian , Xie Liang
Published: September 2023

Narcolepsy is a chronic and underrecognized sleep disorder characterized by excessive daytime sleepiness and cataplexy. Furthermore, narcolepsy type 1 (NT1) has serious negative impacts on an individual's health, society, and the economy. Currently, many sleep centers lack the means to measure orexin levels in the cerebrospinal fluid. We aimed to analyze the characteristics of metabolite changes in patients with NT1, measured by ultra-performance liquid chromatography–tandem mass spectrometry. A principal component analysis (PCA), an orthogonal partial least square discriminant analysis (OPLS-DA), t tests, and volcano plots were used to construct a model of abnormal metabolic pathways in narcolepsy. We identified molecular changes in serum specimens from narcolepsy patients and compared them with control groups, including dehydroepiandrosterone, epinephrine, N-methyl-D-aspartic acid, and other metabolites, based on an OPLS-loading plot analysis. Nine metabolites yielded an area under the receiver operating curve > 0.75. Meanwhile, seven abnormal metabolic pathways were correlated with differential metabolites, such as metabolic pathways; neuroactive ligand‒receptor interaction; and glycine, serine, and threonine metabolism. To our knowledge, this is the first study to reveal the characteristic metabolite changes in sera from NT1 patients for the selection of potential blood biomarkers and the elucidation of NT1 pathogenesis.
LncRNA expression signature identified using genome-wide transcriptomic profiling to predict lymph node metastasis in patients with stage T1 and T2 gastric cancer
Authors: Dong Zhe-bin , Xiang Han-ting , Wu Heng-miao , Cai Xian-lei , Chen Zheng-wei , Chen Sang-sang , He Yi-Chen , Li Hong , Yu Wei-ming , Liang Chao
Published: September 2023

Background

Lymph node (LN) status is vital to evaluate the curative potential of relatively early gastric cancer (GC; T1–T2) treatment (endoscopic or surgery). Currently, there is a lack of robust and convenient methods to identify LN metastasis before therapeutic decision-making.

Methods

Genome-wide expression profiles of long noncoding RNA (lncRNA) in primary T1 gastric cancer data from The Cancer Genome Atlas (TCGA) was used to identify lncRNA expression signature capable of detecting LN metastasis of GC and establish a 10-lncRNA risk-prediction model based on deep learning. The performance of the lncRNA panel in diagnosing LN metastasis was evaluated both in silico and clinical validation methods. In silico validation was conducted using TCGA and Asian Cancer Research Group (ACRG) datasets. Clinical validation was performed on T1 and T2 patients, and the panel’s efficacy was compared with that of traditional tumor markers and computed tomography (CT) scans.

Results

Profiling of genome-wide RNA expression identified a panel of lncRNA to predict LN metastasis in T1 stage gastric cancer (AUC = 0.961). A 10-lncRNA risk-prediction model was then constructed, which was validated successfully in T1 and T2 datasets (TCGA, AUC = 0.852; ACRG, AUC = 0.834). Thereafter, the clinical performance of the lncRNA panel was validated in clinical cohorts (T1, AUC = 0.812; T2, AUC = 0.805; T1 + T2, AUC = 0.764). Notably, the panel demonstrated significantly better performance compared with CT and traditional tumor markers.

Conclusions

The novel 10-lncRNA could diagnose LN metastasis robustly in relatively early gastric cancer (T1–T2), with promising clinical potential.
Applying the Theoretical Domains Framework to Develop an Intervention to ‘Re-implement’ Parent–Child Interaction Therapy (PCIT)
Authors: Woodfield Melanie J. , Phillips Sharon T. , Cargo Tania , Merry Sally N. , McNeil Cheryl B. , Hetrick Sarah E.
Published: September 2023

Parent–Child Interaction Therapy (PCIT) is an empirically supported treatment for childhood conduct problems, with increasing numbers of clinicians being trained in Aotearoa/New Zealand. However, ensuring sustained delivery of effective treatments by trained clinicians in routine care environments is notoriously challenging. The aims of this qualitative study were to (1) systematically examine and prioritise PCIT implementation barriers and facilitators, and (2) develop a well specified and theory-driven ‘re-implementation’ intervention to support already-trained clinicians to resume or increase their implementation of PCIT. To triangulate and refine existing understanding of PCIT implementation determinants from an earlier cross-sectional survey, we integrated previously unanalysed qualitative survey data (54 respondents; response rate 60%) with qualitative data from six new focus groups with 15 PCIT-trained clinicians and managers in Aotearoa/New Zealand. We deductively coded data, using a directed content analysis process and the Theoretical Domains Framework, resulting in the identification of salient theoretical domains and belief statements within these. We then used the Theory and Techniques Tool to identify behaviour change techniques, possible intervention components, and their hypothesised mechanisms of action. Eight of the 14 theoretical domains were identified as influential on PCIT-trained clinician implementation behaviour (Knowledge; Social/Professional Role and Identity; Beliefs about Capabilities; Beliefs about Consequences; Memory, Attention and Decision Processes; Environmental Context and Resources; Social Influences; Emotion). Two of these appeared to be particularly salient: (1) ‘Environmental Context and Resources’, specifically lacking suitable PCIT equipment, with (lack of) access to a well-equipped clinic room appearing to influence implementation behaviour in several ways. (2) ‘Social/Professional Role and Identity’, with beliefs relating to a perception that colleagues view time-out as harmful to children, concerns that internationally-developed PCIT is not suitable for non-Māori clinicians to deliver to Indigenous Māori families, and clinicians feeling obligated yet isolated in their advocacy for PCIT delivery. In conclusion, where initial implementation has stalled or languished, re-implementation may be possible, and makes good sense, both fiscally and practically. This study suggests that re-implementation of PCIT in Aotearoa/New Zealand may be facilitated by intervention components such as ensuring access to a colleague or co-worker who is supportive of PCIT delivery, access to suitable equipment (particularly a time-out room), and targeted additional training for clinicians relating to the safety of time-out for children. The feasibility and acceptability of these intervention components will be tested in a future clinical trial.
Post-fire soil emissions of nitric oxide (NO) and nitrous oxide (N2O) across global ecosystems: a review
Authors: Stephens Elizah Z. , Homyak Peter M.
Published: September 2023

Wildfires may increase soil emissions of trace nitrogen (N) gases like nitric oxide (NO) and nitrous oxide (N2O) by changing soil physicochemical conditions and altering microbial processes like nitrification and denitrification. When 34 studies were synthesized, we found a significant increase in both NO and N2O emissions up to 1 year post-fire across studies spanning ecosystems globally. However, when fluxes were separated by ecosystem type, we found that individual ecosystem types responded uniquely to fire. Forest soils tended to emit more N2O after fire, but there was no significant effect on NO. Shrubland soils showed significant increases in both NO and N2O emissions after fires; often with extremely large but short-lived NO pulses occurring immediately after fire. Grassland NO emissions increased after fire, but the size of this effect was small relative to shrublands. N2O emissions from burned grasslands were highly variable with no significant effect. To better understand the variation in responses to fire across global ecosystems, more consistent measurements of variables recognized as important controls on soil fluxes of NO and N2O (e.g., N cycling rates, soil water content, pH, and substrate availability) are needed across studies. We also suggest that fire-specific elements like burn severity, microbial community succession, and the presence of char be considered by future studies. Our synthesis suggests that fires can exacerbate ecosystem N loss long after they burn, increasing soil emissions of NO and N2O with implications for ecosystem N loss, climate, and regional air quality as wildfires increase globally.
Carboxylation of sulfated cellulose nanocrystals by family AA9 lytic polysaccharide monooxygenases
Authors: Llàcer Navarro Saül , Tõlgo Monika , Olsson Lisbeth , Nypelö Tiina
Published: September 2023

Lytic polysaccharide monooxygenases (LPMOs) from the auxiliary activity 9 (AA9) family act on cellulose through an oxidative mechanism that improves cellulose saccharification in concert with other cellulolytic enzymes. Degradation and solubilization of cellulose chains are known to take place when various cellulose hierarchies, fibers, nanofibers, and cellulose nanocrystals (CNCs) are subjected to LPMOs, either alone or in combination with other cellulose acting enzymes. The use of LPMOs to modify and prepare CNCs has been proposed mostly in top-down synthesis from larger hierarchies. Here, we attempted a direct surface modification of CNCs with LPMOs with the aim of investigating the role played by the charged sulfate groups on CNCs. Sulfate half-ester groups are introduced during the preparation of CNCs from cellulose using sulfuric acid. It has been proposed that the charged sulfate groups hinder the binding of enzymes or affinity of charged reactants on the surface and hence reduce enzymatic and chemical reaction efficiency. We demonstrate the modification of commercial sulfated CNCs using a family AA9 LPMO. Conductometric titration and spectrometric characterization of the oxidized particles indicate that carboxylation of up to 10% was possible without degradation of the crystals. Unexpectedly, the carboxyl groups could only be introduced to the crystals containing sulfate groups, while desulfated crystals remained unfunctionalized. This was deemed to be due to that the sulfate groups limit the adsorption of the enzymes and hence modulate the cuts facilitated by the enzymes on the surface. This limits the release of chains from the surface and enables the carboxylation of the insoluble substrate rather than the release of the solubilized chains. This study highlights the importance of analyzing both the solid and soluble reaction products to gain insights into the oxidation mechanism. We demonstrated that 10% functionalization suffices for the use of CNCs in coupling chemistry.