Elastic Fibers Research Articles

Using Oscillation to Improve the Insertion Depth and Consistency of Hollow Microneedles for Transdermal Insulin Delivery with Mechanistic Insights.

Microneedles (MNs) offer the potential for discrete and painless transdermal drug delivery, yet poor insertion and dosing consistency have hindered their clinical translation. Specifically, hollow MNs are appropriate for the administration of liquid modalities, including insulin, which could prove to be beneficial for patients with type 1 diabetes mellitus. This work aimed to design and manufacture a hollow MN with an improved insertion and delivery profile suitable for insulin administration. Ex vivo insertion studies demonstrated that oscillation of MNs upon insertion into skin produced a favorable insertion profile, with reduced variation, compared to static MN insertion. Histological staining showed that this could be due to the repeated motion of the oscillating MN disrupting elastic fibers in the dermis. Additionally, permeation studies demonstrated that increased quantities of insulin were able to permeate the skin when oscillation was employed compared to static MN insertion. This study has shown that oscillation is a valuable tool in improving the transdermal delivery of insulin via a single hollow MN in vitro. Moving forward, in vivo studies should be completed to gain a fuller understanding of the benefits of the oscillation of MNs on transdermal drug delivery.

Exploring aortic stiffness in aging mice: a comprehensive methodological overview.

Stiffening of the vascular network is associated with the early stages of vascular aging, leading to cardiovascular disorders (hypertension), renal failures, or neurodegenerative diseases (Alzheimer's). Unfortunately, many people remain undiagnosed because diagnostic methods are either unsuitable for a large population or unfamiliar to clinicians which favor the hypertension evaluation. In preclinical research, stiffness studies are often partially conducted. We think that the evaluation of aortic stiffness is essential as it would improve our understanding of aging diseases progression. We propose here a systematic method using decision trees in a multi-scale and multimodal approaches. Our method was evaluated by analyzing the aortic situation in old and young mice. We demonstrate that both the endothelial and smooth muscle cells exhibit pronounced functional alterations in favor of constriction. Additionally, there is significant remodeling of the extracellular matrix, leading to a drastic degradation of elastic fibers and the accumulation of collagen in the aortic wall. This series of changes contributes to the development of vascular rigidity, a preliminary stage of arterial hypertension. Our results suggest that our method should improve preclinical understanding and encourage clinicians to equip themselves with tools for assessing vascular function, as it is an essential issue for preventing numerous pathologies.

Preparation and Characterization of Crimped PLA Fibers With Surface Porous Structure to Promote Cell Adhesion and Growth

ABSTRACTElectrospun fibrous scaffolds are widely used in vascular tissue engineering because they are able to mimic the organizational structure and biological function of a natural extracellular matrix. Improving the topological structure and mechanical properties of electrospun fibrous scaffolds is crucial for achieving good interaction between cells and materials. Herein, oriented polylactic acid (PLA) fibers with surface porous structure were prepared by electrospinning. The orientation degree of the surface porous structure (84.77° ± 5.61°) was highly consistent with the orientation degree of the fiber (83.66° ± 7.31°), which improved the porosity of the fiber and promoted the adhesion of human umbilical vein endothelial cells (HUVECs). Then, by heat treatment, oriented PLA fibers with a surface porous structure were formed into a crimped state, which mimics the crimped structure and nonlinear mechanical properties of the elastic fibers within the blood vessel wall. The crimped PLA fibers with surface porous structure significantly improved the aspect ratio of HUVECs and promoted HUVECs‐oriented growth, which shows certain potential applications in vascular tissue engineering.

Plant Biosensors Analysis for Monitoring Nectarine Water Status

The real-time monitoring of plant water status is an important issue for digital irrigation to increase water productivity. This work focused on a comparison of three biosensors that continuously evaluate plant water status: trunk microtensiometers (MTs), trunk time-domain reflectometry (TDR), and LVDT sensors. During the summer and autumn seasons (DOY 150–300), nectarine trees were subjected to four different consecutive irrigation periods based on the soil Management Allowed Deficit (MAD) concept, namely: MAD10 (light deficit); MAD50 (moderate deficit); MAD100 (severe deficit), and MAD0 (full irrigation). Measurements of stem water potential (Ψstem) and leaf gas exchange were recorded on representative days. A continuous measurement of the plant water status of Ψtrunk, MDS, and Ktrunk revealed the water deficits imposed on the soil. The highest water deficit observed at the end of the MAD100 period (Ψstem = −2.04 MPa and Ɵv = 17%) resulted in a minimum value of Ψtrunk (−1.81 Mpa). The maximum value of MDS (408 µm) was observed earlier than that of Ψtrunk, motivated by the low sensitivity of MDS at Ψtrunk < −1.2 Mpa and Ψstem < −1.5 Mpa due to a decrease in the tissue elasticity of the trunk when severe water deficit conditions are reached. Both Ψtrunk and Ψstem were more dependent on soil water content, while MDS was more responsive to environmental changes. Ktrunk was the weakest indicator for determining plant water status, although when expressed as a daily fraction of depletion (KtrunkFD), it improved, evidencing a process of hysteresis. Ψtrunk showed the highest sensitivity, suggesting the potential use of MTs as a valuable biosensor for monitoring nectarine water status in digital agrosystems.

Fibrillin-1 G234D mutation in the hybrid1 domain causes tight skin associated with dysregulated elastogenesis and increased collagen cross-linking in mice

Fibrillin-1, an extracellular matrix (ECM) protein encoded by the FBN1 gene, serves as a microfibril scaffold crucial for elastic fiber formation and homeostasis in pliable tissue such as the skin. Aside from causing Marfan syndrome, some mutations in FBN1 result in scleroderma, marked by hardened and thicker skin which limits joint mobility. Here, we describe a tight skin phenotype in the Fbn1G234D/G234D mice carrying a corresponding variant of FBN1 in the hybrid1 domain that was identified in a patient with familial aortic dissection. Unlike scleroderma, skin thickness and collagen fiber abundance do not change in the Fbn1G234D/G234D mutant skin. Instead, increased collagen cross-links were observed. In addition, short elastic fibers were sparsely located underneath the panniculus muscle layer, and an abundance of thin, aberrant elastic fibers was increased within the subcutaneous fascia, which may have tightened skin attachment to the underlying skeletal muscle. Structurally, Fbn1G234D/G234D microfibrils have a disrupted shoulder region that shares similarities with hybrid1 deletion mutant microfibrils. We then demonstrate the consequence of fibrillin-1 G234D mutation on dermal fibroblast functions. Mutant primary fibroblasts produce fewer elastic fibers, exhibit slower migration and increased cell stiffness. Moreover, secretome from mutant fibroblasts are marked by enhanced secretion of ECM, ECM-modifying enzymes, proteoglycans and cytokines, which are pro-tissue repair/fibrogenic. The transcriptome of mutant fibroblasts displays an increased expression of myogenic developmental and immune-related genes. Our study proposes that imbalanced ECM homeostasis due to a fibrillin-1 G234Dmutation impacts fibroblast properties with potential ramifications on skin function.

T-cell-related skin inflammatory flareups with Th1 polarity in a patient with pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is a genetic disorder characterized by ectopic calcification of tissues rich in elastic fibres (OMIM 264800). To date, PXE is considered a metabolic disease linked to an imbalance between pro- and anti-calcifying factors. The occurrence of sporadic erythematous flareups of PXE skin lesions is a complaint that we heard about on several occasions at the French PXE reference centre. However, this rare clinical aspect had never been extensively studied. We have had the opportunity to investigate a 13-year-old patient experiencing an erythematous flareup of his PXE lesions. We conducted this work to identify what type of inflammation was implicated in his lesions. An incisional skin biopsy on a recent erythematous inguinal PXE lesion was performed and sent for histological and transcriptomic analyses. The findings were compared to a non-erythematous PXE-affected skin biopsy obtained from another young PXE patient. Histological examination revealed perivascular T-cell infiltrates with Th1 polarity and elevated expression of cytotoxicity markers in RNAseq and RT-qPCR analyses. There was no increase in Th17 or Th2 markers. Our findings support the previous evidence of a possible inflammatory component in the development of PXE. Whether Th1-dependent inflammation contributes to the pathology as an active process or is an aggravating factor requires further investigations.

On tailoring morphing mechanics of a bistable composite cylindrical shell through elastic fibre prestressing

A bistable composite cylindrical shell is a thin-walled structure that can change shape between two stable configurations under small energy input, showing great potential to be applied to space deployable mechanics. The internal stress level within a cylindrical shell plays a vital role in determining its morphing mechanics, whilst tailoring the internal stress is tricky for traditional composite manufacturing methods. In this paper, we devise a novel biaxial elastic fibre prestressing (EFP) method to systematic design and produce prestrained carbon-based composite cylindrical shells, with tailorable bistability and morphing mechanics, as well as improved load-carrying capabilities. A biaxial fibre stretching rig was devised to apply tensions on both directions of a plain-weave carbon prepreg simultaneously; prestrained cylindrical shell samples were produced with various prestrain levels to fully evaluate the fibre prestraining effects; a finite element model was established and showed good agreement with experimental observations. The fibre prestraining mechanisms were then proposed. It is found that EFP is effective in tailoring the internal strain/stress level within a composite cylindrical shell, which in turn altering the structural morphing mechanics, and able to significantly lower the maximum tensile strain during shape-changing, thus improve the load-carrying capability. These findings are expected to facilitate structural design of the deployable composite structures and flexible mechanical hinges, by allowing further design freedoms in terms of morphing mechanics and load-carrying capability.

Elastic Fibers in Orbital Septum.

To examine microscopically the nature of the elastic fibers of the orbital septum in elderly specimens in comparison with the young specimen. Histological evaluation of 15 tissues of the orbital septa from upper eyelid (8 right, 7 left) from 11 Japanese cadavers (age range: 36-94 years old, average: 75.5) was performed. The 36-year-old specimen was the only sample with a young age, so it was used as the reference. The age range of the other specimens was, therefore, from 54 to 94, with an average of 79.4 years old. The specimens were fixed in 10% formalin and stained with Elastica van Gieson. Elastic fibers in the orbital septa were stained with Elastica van Gieson. The elastic fibers from the elderly specimens illustrated fragmentation, but those from the 36-year-old specimen showed flexibility. The elastic fibers in older specimens underwent fragmentation, while those in the young one were flexible.

Influence of flow rate and fiber tension on dynamical, mechanical and acoustical parameters in a synthetic larynx model with integrated fibers.

The human voice is generated by the oscillation of the vocal folds induced by exhalation airflow. Consequently, the characteristics of these oscillations and the primary sound signal are controlled by the longitudinal tension of the vocal folds, the flow rate, and their prephonatoric position. To facilitate independent control of these parameters, a synthetic larynx model was developed, as detailed in a previous publication. This study aims to statistically analyze the influence of airflow and fiber tension on phonation characteristics, such as periodicity and symmetry, glottis closure during vocal fold oscillations, as well as tissue elasticity and generated sound. A total of 76 experiments were conducted and statistically analyzed with a systematic variation of flow rate and longitudinal tension within the vocal folds.During these experiments, vocal fold motion, subglottal pressure, and emitted sound were meticulously measured and analyzed. Groupwise statistical testing identified the flow rate as the main influencing parameter on nearly all phonation characteristics. However, the fundamental frequency, stiffness parameters, and quality parameters of the primary sound signal are predominantly controlled by the longitudinal tension within the vocal folds. The results demonstrated a complex interplay between the flow rate and tension, resulting in different characteristics of the produced sound signal.

Multi-acquisition multi-resolution full-waveform shear wave elastography for reconstructing tissue viscoelasticity.

Motivated by the diagnostic value of tissue viscosity beyond elasticity, the goal of this work is to develop robust methodologies based on shear wave elastography (SWE) to reconstruct combined elasticity and viscosity maps of soft tissues out of the measurement plane. Building on recent advancements in full-waveform inversion (FWI) in reconstructing elasticity maps beyond the measurement plane, we proposed to reconstruct a complete viscoelasticity map by novel combination of three ideas: (a) multiresolution imaging, where lower frequency content is used to reconstruct low resolution map, which is then utilized as a starting point for higher resolution reconstruction by including higher frequency content; (b) acquiring SWE data on multiple planes from multiple pushes, one at a time, and then simultaneously using all the data to invert for a single viscoelasticity map; (c) sequential reconstruction where combined viscoelasticity reconstruction is followed by fixing the elasticity map (and thus kinematics), and repeating the reconstruction but just for the viscosity map. We examine the proposed methodology using synthetic SWE data to reconstruct the viscoelastic properties of both homogeneous and heterogeneous tumor-like inclusions with shear modulus ranging from 3 to 20 kPa, and viscosity ranging from 1 to 3 Pa.s. Final validation is performed in silico, where the annular inclusion is reconstructed using noisy data with varying signal-to-noise ratios (SNR) of 30, 20 and 10 dB. While elasticity images are reasonably reconstructed even for poor SNR of 10 dB, viscosity imaging seem to require better SNR. This work, analogous to reconstructing 3D images from 2D measurements, offers a feasibility study for achieving 3D viscoelasticity reconstructions using conventional ultrasound scanners, potentially leading to biomarkers with greater specificity compared to currently available 2D elasticity images.

Dynamic indentation and microstructural analysis of artery under pre-strain in different directions

Strain from mechanical overload is a critical factor in vascular wall rupture associated with vascular diseases. Therefore, investigating the mechanical properties of blood vessels under strain is essential. Previous studies have predominantly focused on strain-free tests, and lacking microstructural analysis under load conditions. In this study, a self-made indentation device was used to combine with a pre-strain apparatus. Dynamic indentation tests were conducted on porcine arteries under pre-strain. Hematoxylin & Eosin staining and Masson staining were employed to observe microstructural changes in the arteries under strain. The results indicate that under pre-strain, the shear modulus of the arteries is positively correlated with the strain ratio. Radial strain increase the arterial relaxation ratio, while axial strain decrease it. Pre-strain enhance the arterial storage and loss modulus, which peaks at resonance frequencies of approximately 0.04 Hz and 1 Hz. Under pre-strain, elastic fibers experience a decrease in axial diameter and a reduction in spacing. The distribution of collagen is abnormal under radial strain. In the design of artery stents, a rationally designed stent structure should be considered so that the localized strain of the vessel wall is more decomposed into the axial direction.

Effects of Two Decellularization Protocols on the Mechanical Behavior and Structural Properties of the Human Urethra.

This study evaluates the effects of two decellularization protocols, enzyme-detergent (ED) and detergent-detergent (DD), on the structural and biomechanical properties of human urethral tissue. Urethral samples from 18 individuals were divided into ED (n = 7) and DD (n = 11) groups, with native samples (n = 3) serving as controls. Histological and ultrastructural analyses confirmed that both protocols effectively removed cellular content while preserving essential extracellular matrix (ECM) elements, such as collagen and elastic fibers. Immunohistochemical staining for collagen IV and fibronectin revealed no significant differences between decellularized and native tissues, indicating intact ECM structure. Biomechanical testing demonstrated that DD-treated tissues had significantly lower Cauchy stress (1494.8 ± 518.4 kPa) when compared to native tissues (2439.7 ± 578.7 kPa, p = 0.013), while ED-treated tissues were similar to both groups. Both decellularized groups exhibited reduced stretch at failure and elastic modulus compared to native tissues. Cytotoxicity assays using adipose-derived stem cells demonstrated no signs of toxicity in either protocol. Overall, both ED and DD protocols effectively preserved the urethral ECM structure and mechanical properties, making them suitable for potential use in tissue-engineered grafts and for biobanking purposes. Further research is needed to refine and optimize decellularization methods to improve scaffold recellularization and ensure clinical safety and efficacy.

Core-Sheath Heterogenous Interlocked Stretchable Conductive Fiber Induced by Adhesive MXene Modulated Interfacial Soldering.

Whereas high electrical conductivity and mechanical stretchability are both essentially required for flexible electronics, simultaneously achieving them remains a great challenge due to the "trade-off" effect. Herein, an ultrastretchable conductor with core-sheath heterogeneous interlocked structure was developed, induced by interfacial soldering silver nanowires (AgNWs) which gradually evolved into elastic conductive fiber. Adhesive polydopamine-functionalized MXene (PDM) was proposed as an interfacial solder to assemble AgNWs along fibers while induced strong cold-welding effect soldered them into superelastic interconnected network. In situ coaxial heterogeneous interlocking between core AgNWs and sheath PDM network gradually formed during the interfacial soldering process, which enables elastic conductor simultaneously owning large mechanical stretchability and high electrical conductivity. Stretchable conductive fiber with core-sheath heterogeneous interlocking structure not only exhibits excellent electrical conductivity (1.13 × 105 S/m) but also could maintain stability (ΔR/R0 < 0.19) even under large mechanical deformations (300%). Ultrastretchable fibrous conductor with core-sheath heterogeneous interlocked microstructure induced by adhesive PDM interfacial soldering holds great promise in soft electronics.

A Systematic Review of the Association of Elastosis Perforans Serpiginosa and Congenital Disorders

Background: Elastosis perforans serpiginosa (EPS) is a skin condition marked by transepidermal elimination of abnormal elastic fibers, with a classical presentation of papules or plaques arranged in serpiginous, annular, or arcuate patterns on the neck, face, arms, or other flexural regions. A previous review of the literature reported that approximately 1/4 of EPS cases are associated with congenital disorders, including Down syndrome, Ehlers-Danlos syndrome, Marfan syndrome, osteogenesis imperfecta, and pseudoxanthoma elasticum. To the knowledge of these authors, no review examining the association of EPS and congenital disorders has been performed since 1968. Objective: The primary objective of this paper is to perform an updated review of the literature focused on the associations between EPS and congenital disorders. Methods: We searched electronic databases (Medline, Web of Science, PubMed) for literature pertaining to EPS and Down syndrome, Ehlers-Danlos syndrome, Marfan syndrome, osteogenesis imperfecta, and pseudoxanthoma elasticum. Results: Evidence for the association of EPS and congenital disorders is 57 cases from 48 published papers. Conclusions: Our results suggest an association between EPS and congenital disorders. However, current evidence is limited to case reports, underscoring the need for future research investigating the relationship between EPS and congenital disorders.

RVE Simulations of short fiber reinforced polyamide: Direct and inverse matrix parameter identification in view of the semi-crystalline polymer structure

This paper investigates the modeling capabilities of computational homogenization for the mechanical behavior of short fiber reinforced polyamide. Simulations on a representative volume element (RVE) with elastic fibers and an elastic–plastic matrix are compared to tensile experiments on specimens taken in parallel and transversal direction from injection molded plates. In view of the semi-crystalline polymer structure, focus is put on identifying the matrix parameters through two alternative methods:First, the matrix parameters are identified directly using tensile experiments on a non-nucleated and a nucleated unreinforced polyamide. In the RVE computations based on the non-nucleated grade, the composite stress–strain behavior is somewhat underestimated, and with the nucleated grade, the behavior is slightly overestimated. To explain this, the semi-crystalline polymer structure is studied. Polarized light microscopy images reveal that the non-nucleated grade has a coarser and the nucleated grade a finer spherulite structure, compared to the matrix present in the composite. However, the degree of crystallinity measured by differential scanning calorimetry is in a similar range.As an alternative, the matrix parameters are identified inversely by fitting the RVE model to the composite tensile experiments. As uncertainties with respect to the matrix material as well as possibly remaining simplifications in the micromechanical model are compensated for, this reverse engineering approach allows for a very good fit.

HPB SO14 - Surprise Inside: Gallbladder Herniation in a Parastomal Hernia - A Rare Case Report and Management Insight

Abstract Background Parastomal hernias are a common complication of stoma formation, affecting approximately 40% of patients within two years. Gallbladder herniation within a parastomal hernia is a rare phenomenon, with only 18 cases previously reported. Patients are typically elderly females, with the condition attributed to ageing factors such as loss of visceral fat and elastic tissue, liver shrinkage, and the increased length and loss of elasticity of the gallbladder mesentery. These factors contribute to visceroptosis of the gallbladder, increasing its mobility and the risk of herniation. Method We present the case of a 68-year-old female with a four-day history of severe parastomal hernia pain and swelling. She had an emergency left hemicolectomy and transverse colostomy in the right upper quadrant 10 years prior for ischaemic colitis and perforation. Her stoma was functioning well. Vital signs and biochemistry results were normal. On examination her hernia was severely tender but partially reducible. CT revealed a right upper abdominal parastomal hernia containing loops of colon and surprisingly the gallbladder with a long stretched cystic duct. There was no evidence of cholecystitis, bowel obstruction, or compromise within the hernial sac. Results With analgesia, the patient's pain improved, though her hernia remained irreducible. She was discharged after two days of conservative management and referred back to the hospital where she had the initial operation. On enquiry with that hospital it was reported that an elective parastomal hernia repair with completion right colectomy and end ileostomy was performed. The gallbladder was mobilised and reduced back into the peritoneal cavity, and the hernial defect was closed. The patient made an excellent recovery and was discharged home three days after surgery. Conclusion Cholecystic parastomal herniation is a very rare phenomenon and should be considered as a differential in similar cases. Management should be based on clinical presentation, radiological diagnosis, and a multidisciplinary team approach. No standardised classification or approach exists. We propose classifying gallbladder herniations as either being simple (without inflammatory sequelae) or complicated (with cholecystitis, gallbladder torsion, incarceration or perforation). Simple herniations, such as the case presented, can be managed electively with intra-operative reduction of the gallbladder sufficing. Complicated herniations during acute admissions indicate the need for emergency surgical intervention with combined cholecystectomy and parastomal hernia repair.

Histological, histochemical, and immunohistochemical characterization of NANOULCOR nanostructured fibrin-agarose human cornea substitutes generated by tissue engineering

BackgroundHuman artificial corneas (HAC) generated by tissue engineering recently demonstrated clinical usefulness in the management of complex corneal diseases. However, the biological mechanisms associated to their regenerative potential need to be elucidated.MethodsIn the present work, we generated HAC using nanostructured fibrin-agarose biomaterials with cultured corneal epithelial and stromal cells, and we compared the structure and histochemical and immunohistochemical profiles of HAC with control native corneas (CTR-C) and limbus (CTR-L) to determine the level of biomimicry of the HAC with these two native organs.ResultsHAC tissues consisted of a stratified epithelium and a cellular stromal substitute. The interface between stroma and epithelium was similar to that of CTR-C, without the finger-shaped palisades of Vogt found in CTR-L, and contained a poorly developed basement membrane as determined by PAS histochemistry. Analysis of the stromal layer revealed that HAC contained significantly lower amounts of extracellular matrix components (collagen, proteoglycans, decorin, keratocan, and lumican) than CTR-C and CTR-L, with all samples being devoid of elastic and reticular fibers. At the epithelial level, HAC were strongly positive for several cytokeratins, although KRT5 was lower in HAC as compared to CTR-C and CTR-L. The expression of crystallin lambda was lower in HAC than in control tissues, whereas crystallin alpha-a was similar in HAC and CTR-C. No differences were found among HAC and controls for the cell–cell junction proteins CX43 and TJP1. When specific markers were analyzed, we found that HAC expression profile of KRT3, KRT19, KRT15, and ΔNp63 was more similar to CTR-L than to CTR-C.ConclusionsThese results suggest that HAC generated in the laboratory could be structurally and functionally more biomimetic to the structure found at the corneal limbus than to the central cornea, and open the door to the use of these artificial tissues in patients with limbal deficiency.

Heart ultrasound and biomechanical evaluation of radiation‐induced heart toxicity using transthoracic echocardiogram (TTE) and dynamic mechanical analysis (DMA)

AbstractRadiation‐induced heart disease (RIHD) is a serious complication but difficult to assess in patients undergoing thoracic radiotherapy (RT). We aim to analyze RIHD using heart ultrasound and elastic modulus, exploring relationships between functional, anatomical or biomechanical changes of the heart and radiation dose.Twenty BALB/c mice were divided into four groups (control, 10 Gy, 20 Gy and 25 Gy) with a single fraction of image‐guided volumetric modulated arc radiotherapy (VMAT) to murine heart on a linear accelerator. Transthoracic echocardiography (TTE) was performed on a small‐animal ultrasound imaging system with a handheld microscan transducer. E‐wave/A‐wave ratio (E/A) and myocardial performance index (MPI) for diastolic performance were noninvasively evaluated weekly, as well as ejection fraction (EF%), fractional shortening (FS%), left ventricle (LV) mass and heart wall thickening for systolic performance. At the end of the fifth week, all mice were sacrificed for elastic modulus measurement on a dynamic mechanical analyzer (DMA) and for histopathological staining. All experiments were conducted in accordance with the local institution's animal research committee guideline.Significant difference was observed in E/A ratio between the control and 25 Gy irradiated groups (1.8±0.5 and 0.7±0.9, respectively; p&lt;0.05), indicating reduced diastolic performance and increased stiffness in left ventricle after high‐dose heart radiation. Diastolic dysfunction in irradiated groups was also observed with significantly increased MPI. In contrast, posterior wall thickness, aortic peak velocity, heart rate, EF and FS were not significantly different after RT. Heart elasticity was reduced substantially with the increased radiation dose. HE and Masson Trichrome staining confirmed more fibrosis deposition in irradiated hearts.RIHD evaluation with ultrasound imaging noninvasively and biomechanical modulus measurement invasively in the image guided, precision dose‐escalated murine heart irradiation is feasible. Increased myocardial stiffness, abnormal diastolic relaxation, more collagen deposition, and reduced tissue elasticity are observed in irradiated heart tissue. This study may facilitate our understanding of RIHD and facilitate improving patients’ quality of life in the future.

Transcriptomic and Metabolomic Insights into Age-Related Changes in Lung Tissue of Yaks Under Highland Stress.

As an indigenous species on the Tibetan Plateau, the yak is well adapted to the plateau hypoxic environment. The high-altitude hypoxia adaptation of the yak requires the adaptive reshaping of multiple tissues and organs, especially the lungs. To reveal the adaptive development of yak lungs under hypoxic stress at the tissue and molecular levels, we conducted histomorphological observations as well as transcriptomic and metabolomic studies of yak lungs at three ages (0.5, 2.5, and 4.5 years). The results showed that the lung tissue developed significantly with age. The mean alveolar area was higher (p < 0.01) in 4.5 and 2.5-year-old yaks than in 0.5-year-old yaks. The percentage of elastic fibers, micro-arterial wall thickness, and micro-arterial area showed an increasing trend (p < 0.01) from 0.5-year-old yaks to 2.5-year-old yaks and then to 4.5-year-old yaks. In addition, some critical differentially expressed genes related to angiogenesis (MYC, EPHA2, TNF), fiber formation (EREG), smooth muscle proliferation (HBEGF), erythropoiesis (SOCS3), and hypoxia response (ZFP36) were identified. Some metabolites associated with these genes were also found simultaneously. These findings provide a deeper understanding of the molecular strategies underlying this species' extraordinary ability to survive normally in low-oxygen environments. In conclusion, the lungs of yaks undergo continuous adaptive development under hypoxic stress, and these findings are crucial for understanding the molecular mechanisms by which native species of the Tibetan Plateau survive in harsh environments.

Changes associated with dietary beetroot extract on diet-induced damage in the common carotid artery of the albino rat (&lt;i&gt;Rattus norvegicus&lt;/i&gt;)

The high-fat high-fructose diet (HFHFr) has become widespread globally corresponding to a rise in obesity and cardiovascular diseases. Traditionally, these diseases were managed by multiple-drug regimens whose adherence was limited by side effects, hence leading to consideration of natural compounds. Recent studies have exploited the phytochemical properties of numerous plant extracts in ameliorating the histological changes seen in common carotid artery (CCA) damage, however, hardly any studies have investigated the effect of beetroot extract. The CCA were obtained from a biobank of a study that induced HFHFr in 45 male rats. Rats in the control group had received standard rat chow and water, and the positive control group received HFHFr. Those in the experimental group received HFHFr and 200mg/kg beetroot extract. These rats were randomly selected, euthanized and perfused on weeks 4,8,10 and 16. Their CCA were harvested, processed and stereological techniques applied to determine the densities of different histological components of the CCA.The HFHFr fed experimental animals revealed medial vascular thickening with a resultant increase in carotid intima-media thickness, increased vascular smooth muscle density, reduced elastic fiber density, and increased collagen fiber density compared to controls. Beetroot coadministration was protective against most of these structural changes. Dietary administration of beetroot extract has been found to be ameliorative to structural changes on the CCA following administration of HFHFr. Therefore, dietary beetroot extract may be indicated to mitigate harmful changes following long term exposure to a high fat high fructose diet.