Local pore size correlations determine flow distributions in porous media

The relationship between the microstructure of a porous medium and the observed flow distribution is still a puzzle. We resolve it with an analytical model, where the local correlations between adjacent pores, which determine the distribution of flows propagated from one pore downstream, predict the flow distribution. Numerical simulations of a two-dimensional porous medium verify the model and clearly show the transition of flow distributions from $\delta$-function-like via Gaussians to exponential with increasing disorder. Comparison to experimental data further verifies our numerical approach.Comment: 5 pages, 3 figures, supplemental materia

Measurements of the Solid-body Rotation of Anisotropic Particles in 3D Turbulence

We introduce a new method to measure Lagrangian vorticity and the rotational dynamics of anisotropic particles in a turbulent fluid flow. We use 3D printing technology to fabricate crosses (two perpendicular rods) and jacks (three mutually perpendicular rods). Time-resolved measurements of their orientation and solid-body rotation rate are obtained from stereoscopic video images of their motion in a turbulent flow between oscillating grids with $R_\lambda$=$91$. The advected particles have a largest dimension of 6 times the Kolmogorov length, making them a good approximation to anisotropic tracer particles. Crosses rotate like disks and jacks rotate like spheres, so these measurements, combined with previous measurements of tracer rods, allow experimental study of ellipsoids across the full range of aspect ratios. The measured mean square tumbling rate, $\langle \dot{p}_i \dot{p}_i \rangle$, confirms previous direct numerical simulations that indicate that disks tumble much more rapidly than rods. Measurements of the alignment of crosses with the direction of the solid-body rotation rate vector provide the first direct observation of the alignment of anisotropic particles by the velocity gradients of the flow.Comment: 15 pages, 7 figure

Rotation Rate of Rods in Turbulent Fluid Flow

The rotational dynamics of anisotropic particles advected in a turbulent fluid flow are important in many industrial and natural setting. Particle rotations are controlled by small scale properties of turbulence that are nearly universal, and so provide a rich system where experiments can be directly compared with theory and simulations. Here we report the first three-dimensional experimental measurements of the orientation dynamics of rod-like particles as they are advected in a turbulent fluid flow. We also present numerical simulations that show good agreement with the experiments and allow extension to a wide range of particle shapes. Anisotropic tracer particles preferentially sample the flow since their orientations become correlated with the velocity gradient tensor. The rotation rate is heavily influenced by this preferential alignment, and the alignment depends strongly on particle shape

Assessing Heavy Metal Coagulation in Autopurification at the Estuary of Shafarood River

Due to its particular physical and chemical conditions, river estuary can affect the structure and concentration of heavy metals present in river water at the time of mixing freshwater and seawater. The mixing of saline and fresh water plays an essential role in autopurification and sedimentation of heavy metals. In the present study, the autopurification of Cd, Co, Ni, Cr and Pb elements was assessed during mixing of Caspian Sea and Shafarood River freshwater in its estuary under laboratory conditions and through controlled potential reduction, pH, DO, and salinity. The rate of heavy metal flocculation at the estuary was Cd (62.2%

Comparison between shoulder flexed and extended positions in elbow flexion resistance training on regional hypertrophy and maximum strength: Preacher versus Bayesian cable curls

In the present study, the effects of resistance training on regional hypertrophy and maximum strength of the elbow flexor muscles were compared between elbow flexion exercises performed with different shoulder joint angles (∼50° of flexion vs. extension) while matched for resistance profiles. In a within-subject design, 15 young men (25.6 ± 2.1 y; 77.3 ± 6.8 kg; 175.1 ± 5.7 cm) underwent a resistance training program twice a week for 10 weeks (3–5 sets, 8–12RM), and their arms were dominant-side balanced, randomly assigned to one of the two conditions according to elbow flexion exercises: unilateral cable curl with shoulder flexed (Preacher curl; PREA) or unilateral cable curl with shoulder extended (Bayesian curl; BAYE). B-mode ultrasound imaging was used to measure changes in muscle thickness of the biceps brachii and brachialis at proximal, mid, and distal arm regions, and one-repetition maximum tests were completed in each respective trained exercise before and after training. Both conditions showed significant increases in muscle thickness (p \u3c 0.05) with no significant differences between them (p \u3e 0.05) across the biceps brachii proximal, mid, and distal regions (relative change [Hedges\u27 g effect size]; PREA: 6%[0.51], 7%[0.49], 7%[0.53]; BAYE: 9%[0.73], 9%[0.62], 9%[0.62]) and brachialis (PREA: 10%[0.72]; BAYE: 8%[0.65]). Similarly, significant improvements in maximum strength were observed (p \u3c 0.05), with equivalent results between conditions (PREA: 28%[0.85], BAYE: 37%[1.22]; equivalence testing, p-values = 0.061, 0.637). In conclusion, the shoulder joint angle does not seem to affect muscle hypertrophy and maximum strength gains after different elbow flexion exercises matched for resistance profiles

The Ameliorative Effect of Adipose-Derived Mesenchymal Stem Cells and Their Exosomes in Non-alcoholic Steatohepatitis by Simultaneously Enhancing Autophagic Flux and Suppressing Endoplasmic Reticulum Stress

Background: Due to the scarcity of treatment options, managing the progression of non-alcoholic fatty liver disease (NAFLD) from steatosis to cirrhosis necessitates innovative approaches. This study focused on endoplasmic reticulum (ER) stress, apoptosis, and autophagy as key mechanisms in NAFLD pathogenesis. It also highlighted the potential of adipose-derived mesenchymal stem cells (AD-MSCs) and their exosomes as promising therapeutic options.Methods: The study was conducted at the Department of Regenerative Medicine, Shiraz University of Medical Sciences, (Shiraz, Iran) from November 2021 to December 2023. The mice (n=32) were divided into four groups: control, high-fat diet (HFD) without treatment, HFD with AD-MSCs treatment, and HFD with AD-MSCs-derived exosomes groups. The mice were fed HFD for 8 weeks. They received MSC and exosomes for the last 3 weeks. One week after the final injection, mice were tested for serum testing, stereological analysis, and real-time polymerase chain reaction (RT-PCR). The data were analyzed using the Graph-Pad Prism software by one-way analysis of variance (ANOVA) with Tukey analysis as a post hoc comparison between groups. P<0.05 indicated a significant difference. Results: AD-MSCs-exosomes significantly reduced ER stress indicators (IRE1α [P=0.0001], PERK [P=0.0006], ATF6 [P=0.0001], and GRP78 [P=0.0001]), apoptosis markers (Bax [P=0.005] and Cas3 [P=0.001]), and autophagic flux markers (P62 [P=0.0001] and LC3B/A [P=0.003]). Conclusion: In this investigation, AD-MSCs-exosomes significantly restored autophagy and suppressed unfolded protein response (UPR) pathways in the early stages of NAFLD

The Effect of Mesenchymal Stem Cells Derived-Conditioned Media in Combination with Oral Anti-Androgenic Drugs on Male Pattern Baldness: An Animal Study

Objective: Androgenetic alopecia (AGA) is a prevalent form of hair loss, mainly caused by follicular sensitivity toandrogens. Despite developing different anti-androgen treatment options, the success rate of these treatments hasbeen limited. Using animal models, this study evaluated the therapeutic effects of umbilical cord (UC) stem cellconditioned media (CM) combined with oral anti-androgens for hair regeneration.Materials and Methods: In this experimental study, Poloxamer 407 (P407) was used as a drug carrier forsubcutaneous testosterone injection. AGA models were treated with oral finasteride, oral flutamide, and CMinjections. Samples were thoroughly evaluated and compared using histological, stereological, and molecularanalyses.Results: Injecting CM-loaded hydrogel alone or combined with oral intake of anti-androgens improved hair regeneration.These treatments could promote hair growth by inducing hair follicles in the anagen stage and shortening the telogenand catagen phases. Furthermore, the combination treatment led to an upregulation of hair induction gene expressionwith a downregulation of inflammation genes.Conclusion: Through a reduction in inflammation, injection of CM-loaded hydrogel alone or combined with oral intakeof anti-androgens induces the hair cell cycle with regeneration in damaged follicles. Hence, this could be a promisingtherapeutic method for AGA patients

Application of deep learning models to improve ulcerative colitis endoscopic disease activity scoring under multiple scoring systems

Background and Aims Lack of clinical validation and inter-observer variability are two limitations of endoscopic assessment and scoring of disease severity in patients with ulcerative colitis [UC]. We developed a deep learning [DL] model to improve, accelerate and automate UC detection, and predict the Mayo Endoscopic Subscore [MES] and the Ulcerative Colitis Endoscopic Index of Severity [UCEIS]. Methods A total of 134 prospective videos [1550 030 frames] were collected and those with poor quality were excluded. The frames were labelled by experts based on MES and UCEIS scores. The scored frames were used to create a preprocessing pipeline and train multiple convolutional neural networks [CNNs] with proprietary algorithms in order to filter, detect and assess all frames. These frames served as the input for the DL model, with the output being continuous scores for MES and UCEIS [and its components]. A graphical user interface was developed to support both labelling video sections and displaying the predicted disease severity assessment by the artificial intelligence from endoscopic recordings. Results Mean absolute error [MAE] and mean bias were used to evaluate the distance of the continuous model’s predictions from ground truth, and its possible tendency to over/under-predict were excellent for MES and UCEIS. The quadratic weighted kappa used to compare the inter-rater agreement between experts’ labels and the model’s predictions showed strong agreement [0.87, 0.88 at frame-level, 0.88, 0.90 at section-level and 0.90, 0.78 at video-level, for MES and UCEIS, respectively]. Conclusions We present the first fully automated tool that improves the accuracy of the MES and UCEIS, reduces the time between video collection and review, and improves subsequent quality assurance and scoring