Search Results (134)

Background: Previously, we found that the pathological changes in the corpus spongiosum (CS) in hypospadias were mainly localized within smooth muscle tissue, presenting as a transformation from the contraction phenotype to synthesis. The role of low-intensity pulsed ultrasound (LIPUS) in regulating smooth muscle cells (SMCs) and angiogenesis has been confirmed. Objectives: To demonstrate the feasibility of regulating the phenotypic transformation of corpus spongiosum smooth muscle cells (CSSMCs) in hypospadias using LIPUS and to explore the potential mechanisms. Materials and Methods: The CSSMCs were extracted from CS in patients with proximal hypospadias. In vitro experiments were conducted to explore the appropriate LIPUS irradiation intensity and duration which could promote the phenotypic transformation of CSSMCs. A total of 71 patients with severe hypospadias were randomly divided into a control group and a LIPUS group to verify the in vivo transition effect of LIPUS. Consequently, the potential mechanisms by which LIPUS regulates the phenotypic transformation of CSSMCs were explored in vitro. Results: In vitro experiments showed that LIPUS with an intensity of 100 mW/cm² and a duration of 10 min could significantly increase the expression of contraction markers in CSSMCs and decrease the expression of synthesis markers. Moreover, LIPUS stimulation could alter the phenotype of CSSMCs in patients with proximal hypospadias. RNA sequencing results revealed that peroxisome proliferator-activated receptor gamma (PPAR-γ) significantly increased after LIPUS stimulation. Overexpression of PPAR-γ significantly increased the expression of contraction markers in CSSMCs, and the knockdown of PPAR-γ blocked this effect. Conclusions: LIPUS can regulate the transition of CSSMCs from a synthetic to a contractile phenotype in hypospadias. The PPAR-γ-mediated signaling pathway is a possible mechanism involved in this process. Full article

This paper studies the convergence of distances between sequences of points and that of sequences of points in metric spaces. This investigation is focused on the iterative processes built with composed self-mappings of a cyclic contraction, which can involve more than two nonempty closed subsets in a metric space, which are combined with compositions of a strict contraction with itself, which operates in each of the individual subsets, in any order and any number of mutual compositions. It is admitted, in the most general case, the involvement of any number of repeated compositions of both self-maps with themselves. It is basically seen that, if one of the best-proximity points in the cyclic disposal is unique in a boundedly compact subset of the metric space is sufficient to achieve unique asymptotic cycles formed by a best-proximity point per each adjacent subset. The same property is achievable if such a subset is strictly convex and the metric space is a uniformly convex Banach space. Furthermore, all the sequences with arbitrary initial points in the union of all the subsets of the cyclic disposal converge to such a limit cycle. Full article

Background: Suprascapular neuropathy is a known cause of shoulder pain. Although neurodynamic techniques are widely used to treat peripheral neuropathies, the mechanical behavior of the suprascapular nerve in the shoulder region remains poorly understood. Objectives: This study aimed to analyze the mechanical behavior of the suprascapular nerve during a contralateral cervical glide and an infraspinatus muscle contraction. Methods: The study was conducted in two phases. First, nerve movement was analyzed in 12 cryopreserved cadaveric shoulders using anatomical dissection. Second, suprascapular nerve displacement was assessed in 34 shoulders from 17 healthy volunteers using ultrasound imaging. Results: In cadaveric dissections, the contralateral cervical glide produced a proximal nerve displacement of 1.85 mm at the suprascapular notch. In the ultrasound study, this maneuver resulted in horizontal and vertical displacements of 1.18 mm and 0.39 mm, respectively. In contrast, infraspinatus muscle contraction caused a distal displacement of 3.21 mm in the cadaveric study, and ultrasound imaging showed horizontal and vertical displacements of 1.34 mm and 0.75 mm, respectively. All reported displacements were statistically significant (p < 0.05). Conclusions: The findings of both phases of the study contribute to a better understanding of suprascapular nerve biomechanics and may inform clinical neurodynamic interventions. Full article

Traditional cattle health monitoring systems rely on centralized data collection, posing significant challenges related to data privacy, network connectivity, model reliability, and trust. This study introduces a novel, nature-inspired federated learning (FL) framework for cattle health monitoring, integrating blockchain to ensure model validation, system resilience, and reputation management. Inspired by the fission–fusion dynamics of elephant herds, the framework adaptively forms and merges subgroups of edge nodes based on six key parameters: health metrics, activity levels, geographical proximity, resource availability, temporal activity, and network connectivity. Graph attention networks (GATs) enable dynamic fission, while Density-Based Spatial Clustering of Applications with Noise (DBSCAN) supports subgroup fusion based on model similarity. Blockchain smart contracts validate model contributions and ensure that only high-performing models participate in global aggregation. A reputation-driven mechanism promotes reliable nodes and discourages unstable participants. Experimental results show the proposed framework achieves 94.3% model accuracy, faster convergence, and improved resource efficiency. This adaptive and privacy-preserving approach transforms cattle health monitoring into a more trustworthy, efficient, and resilient process. Full article

The growing interest in decentralized finance (DeFi), driven by advancements in blockchain technologies such as Ethereum, highlights the crucial role of smart contracts. However, the inherent openness of blockchains creates an extensive attack surface, exposing participants’ funds to undetected security flaws. In this work we investigated the use of deep reinforcement learning techniques, specifically Deep Q-Network (DQN) and Proximal Policy Optimization (PPO), for detecting and classifying vulnerabilities in smart contracts. This approach utilizes control flow graphs (CFGs) generated through EtherSolve to capture the semantic features of contract bytecode, enabling the reinforcement learning models to recognize patterns and make more accurate predictions. Experimental results from extensive public datasets of smart contracts revealed that the PPO model performs better than DQN and demonstrates effectiveness in identifying unchecked-call vulnerability. The PPO model exhibits more stable and consistent learning patterns and achieves higher overall rewards. This research introduces a machine learning method for enhancing smart contract security, reducing financial risks for users, and contributing to future developments in reinforcement learning applications. Full article

Let nonempty subsets E and F of a Banach space X be given, along with a mapping $\mathcal{S}:E\cup F\to E\cup F$ defined as noncyclic when $\mathcal{S}\left(E\right)\subseteq E$ and $\mathcal{S}\left(F\right)\subseteq F$. In this case, an optimal pair of fixed points is defined as a point $(p,q)\in E\times F$ where p and q are fixed points of $\mathcal{S}$ that estimate the distance between E and F. This article explores an extended version of Göhde’s fixed point problem to identify optimal fixed point pairs for noncyclic relatively nonexpansive maps in strictly convex Banach spaces, while introducing new classes of noncyclic Kannan contractions, noncyclic relatively Kannan nonexpansive contractions using the proximal projection mapping defined on union of proximal pairs, and proving additional existence results with supporting examples. Full article

In this article, we will introduce a new generalized proximal $\theta$-contraction for multivalued and single-valued mappings named ${(\mathcal{f}-{\theta }_{\kappa })}_{C_P}$-proximal contraction and ${(\mathcal{f}-{\theta }_{\kappa })}_{B_P}$-proximal contraction. Using these newly constructed proximal contractions, we will establish new results for the coincidence best proximity point, best proximity point, and fixed point for multivalued mappings in the context of rectangular metric space. Also, we will reduce these contractions for single-valued mappings, named ${\left({\theta }_{\kappa }\right)}_{C_P}$-proximal contraction and ${\left({\theta }_{\kappa }\right)}_{B_P}$-proximal contraction, to establish results for the coincidence proximity point, best proximity point, and fixed point results. We will give some illustrated examples for our newly generated results with graphical representations. In the last section, we will also find the solution to the equation of motion by using our defined results. Full article

A new kind of graph-based contraction in a metric space is introduced in this article. We investigate results concerning the best proximity points and fixed points for these contractions, supported by illustrated examples. The practical applicability of our results is demonstrated through particular instances in the setting of integral equations and differential equations. We also describe how a class of third-order boundary value problems satisfying the present contraction can be solved iteratively. To support our findings, we conduct a series of numerical experiments with various third-order boundary value problems. Full article

Rural homestays have emerged as pivotal drivers of rural socioeconomic revitalization, particularly in metropolitan peripheries characterized by intensified urban–rural dynamics. However, their spatiotemporal distribution patterns and underlying mechanisms remain underexplored. This study employs Geodetector and related analytical methods to examine rural homestays in Beijing, aiming to decipher spatial heterogeneity and driving factors. The results reveal a distinct “large-scale dispersion with small-scale clustering” pattern marked by pronounced agglomeration in northern mountainous areas and sparse distributions in southern suburban regions. Temporally, the sector currently exhibits a notable expansion–contraction phase influenced by external factors, alongside spatial centroid migration toward resource-rich zones. Geodetector quantification identifies the proximity to transportation nodes and vegetation coverage as primary spatial determinants, while socioeconomic factors demonstrate comparatively limited influence—contrasting sharply with urban contexts. Rural homestay concentration zones are classified into high-, medium-, and low-intensity categories based on the homestay density, with high-intensity zones leveraging apex advantages of scenic resources, cultural heritage, and infrastructure. These findings underscore the interplay of natural environmental factors, tourism resources, transportation accessibility, and socioeconomic conditions in shaping agglomeration dynamics, providing actionable insights for optimizing spatial planning and promoting sustainable development in rural regions adjacent to megacities. Full article

This paper presents the design, kinematics, and development of a tendon-driven continuum robot for surgical applications. The continuum robot has a flexible and adaptable construction that imitates the movements of natural organisms. The robot’s unique structure comprises disk members, springs, and a continuum backbone member, enabling it to bend, contract, and deform in complex ways. The robot is operated by pulling tendons, giving it the agility and flexibility necessary to bend in confined spaces. This study discusses the main design considerations and challenges in creating a tendon-driven continuum robot, including the kinematics of the four-tendon mechanism. The developed tendon-driven continuum robot is categorized into two modules: the distal end and the proximal end. The distal end consists of the continuum robot structure, whereas the proximal module consists of the actuating unit that actuates the distal end. The experimental results demonstrate the continuum robot’s ability to be used in medical fields and pipe inspections because of the miniaturized design of the distal end, which allows it to enter confined spaces. This paper provides valuable insights into the design, kinematics, and appropriate materials to build a tendon-driven continuum robot; its bending and deformation capabilities can be used in many fields, especially surgical applications and confined space explorations. Full article

In this paper, we present the concept of $(\mathrm{{\rm Y}},\mathrm{\Omega })$-iterativemappings in the setting of fuzzy bipolar metric space. The symmetric property in fuzzy bipolar metric spaces guarantees that the distance between any two elements remains invariant under permutation, ensuring consistency and uniformity in measurement regardless of the order in which the elements are considered. Furthermore, we prove several best proximity point results by utilizing $(\mathrm{{\rm Y}},\mathrm{\Omega })$-fuzzy bipolar proximal contraction, $(\mathrm{{\rm Y}},\mathrm{\Omega })$-Reich–Rus–Ciric type proximal contraction, $(\mathrm{{\rm Y}},\mathrm{\Omega })$-Kannan type proximal contraction and $(\mathrm{{\rm Y}},\mathrm{\Omega })$-Hardy–Rogers type contraction. Furthermore, we provide some non-trivial examples to show the comparison with the existing results in the literature. At the end, we present an application to find the existence and uniqueness of a solution of an integral equation by applying the main result. Full article

We propose a novel approach to fractals by leveraging the approximation of fixed points, emphasizing the deep connections between fractal theory and fixed-point theory. We include a condition of isomorphism, which not only generates traditional fractals but also introduces the concept of generating two fractals simultaneously, using the framework of the best proximity point: one as the original and the other as its best proximity counterpart. We present a notion of the Proximal $\mathcal{F}-$Iterated Function System ($\mathcal{F}-$PIFS), which is constructed using a finite set of ${\mathcal{F}}^{*}-$weak proximal contractions. This extends the classical notions of Iterated Function Systems (IFSs) and Proximal Iterated Function Systems (PIFSs), which are commonly used to create fractals. Our findings show that under specific conditions in a metric space, the $\mathcal{F}-$PIFS has a unique best attractor. In order to illustrate our findings, we provide an example showing how these fractals are generated together. Furthermore, we intend to investigate the possible domains in which our findings may be used. Full article

In this paper, we delve into the ideas of Geraghty-type proximal contractions and their relation to multivalued, single-valued, and self mappings. We begin by introducing the notions of ${\left(\psi \omega \right)}_{MCP}$-proximal Geraghty contraction and rational ${\left(\psi \omega \right)}_{RMCP}$-proximal Geraghty contraction for multivalued mappings, aimed at establishing coincidence point results. To enhance our understanding and illustrate the concepts, practical examples are provided with each definition. This study extends these contractions to single-valued mappings with the introduction of ${\left(\psi \omega \right)}_{SCP}$-proximal Geraghty contraction and rational ${\left(\psi \omega \right)}_{RSCP}$-proximal Geraghty contraction, supported by relevant examples to reinforce the main results. Then, we explore ${\left(\psi \omega \right)}_{SFP}$ Geraghty contraction and rational ${\left(\psi \omega \right)}_{RSFP}$ contraction for self-mappings, obtaining fixed point theorems and clearly illustrating them through examples. Finally, we apply the theoretical framework developed to investigate the existence and uniqueness of solutions to certain two-dimensional Volterra integral equations. Specifically, we consider the transformation of first-kind Volterra integral equations, which play crucial roles in modeling memory in diverse scientific fields like biology, physics, and engineering. This approach provides a powerful tool for solving difficult integral equations and furthering applied mathematics research. Full article

In this manuscript, for the purpose of investigating the coincidence best proximity point, best proximity point, and fixed point results via alternating distance $\varphi$, we discuss some multivalued ${(\varphi -{\mathcal{F}}_{\tau })}_{C_P}$ and ${(\varphi -{\mathcal{F}}_{\tau })}_{B_P}-$proximal contractions in the context of rectangular metric spaces. To ascertain the coincidence best proximity point, best proximity point, and the fixed point for single-valued mappings, we reduce these findings using ${({\mathcal{F}}_{\tau })}_{C_P}$ and ${({\mathcal{F}}_{\tau })}_{B_P}-$proximal contractions. To make our work more understandable, examples of both single- and multivalued mappings are provided. These examples support our core findings, which rely on coincidence points, as well as the corollaries that address fixed point conclusions. In the final phase of our study, we use the obtained results to verify that a solution to a Fredholm integral equation exists. This application highlights the theoretical framework we built throughout our study. Full article

Objective: The purpose of this cadaveric investigation was to provide a detailed morphologic description of the proximal gastrocnemius within the popliteal region of the knee and test the hypothesis that the gastrocnemius is anatomically positioned to function as an antagonist to the anterior cruciate ligament (ACL) of the knee. Methods: Twenty-two lower limbs from 11 embalmed cadavers underwent detailed dissection and anatomical analysis. Results: The results indicate that 63.3 ± 5.8% of the popliteal region is comprised of the hamstrings and the gastrocnemius, whereas 36.8 ± 5.7% is occupied by free space (fossa). Within the popliteal region, the gastrocnemius had a length crossing above the knee joint line of 5.4 ± 1.2 cm, which would likely result in a posterior pull on the femur during muscular contraction. Data provide an in-depth description of length and width morphology of the gastrocnemius and provide a detailed comparison between the medial and lateral heads of the muscle. Our results agree with earlier reports in the literature which suggest that the medial head is significantly longer and wider than the lateral head of the gastrocnemius. The medial head length was 23 ± 3.4 cm, compared to a lateral head length of 20.5 ± 2.9 cm. The medial head maximum width was 5.5 ± 1.6 cm, compared to a lateral head maximum width of 4.2 ± 1.1 cm. Conclusion: This research expands on past descriptions of the femoral origin of the gastrocnemius muscle’s medial head and confirms past descriptions of the lateral head origin on the femur. Our data clearly illustrate that the femoral attachment of the medial head of the gastrocnemius was much different (or more complex) than previously described and that it wraps around the posterior side of the medial femoral condyle and attaches more anteriorly. Further research should be directed at exploring the functional significance (if any) of these differences and examining the effect they may have on ACL function and knee joint kinematics. Full article