Thick Fibers Research Articles

A Study on Structural Changes During the Thermal Stabilization Stage of Hemp Fibers Impregnated with Phosphoric Acid Before Carbonization and Activation

Abstract After being wet treated with 4% phosphoric acid (H3PO4) aqueous solution, industrial hemp fiber was subjected to thermal stabilization processes at temperatures of 160, 180, 200, 220, 240 and finally 250 °C and holding times of 30 min. Some basic analyses were used to determine the structural and characteristic changes of all samples for the thermal stabilization of hemp fibers in an oxygen environment before the carbonization and activation processes. These included linear density, fiber thickness, flame testing, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), infrared spectroscopy (IR), X-ray diffraction, and Scanning Electron Microscopy (SEM) measurements. DSC analysis showed that impregnation of the phosphoric acid (PA) mixture increased thermal stabilization and prevented the formation of volatile products by blocking the hydroxyl groups in the cellulose structure. TGA thermograms showed an increase in carbon yield at increasing stabilization temperature values. The results from XRD indicated that the cellulose II crystal structure disappears with the increase of the stabilization temperature and an amorphous structure appears. IR spectra show that the partial loss of intramolecular and intermolecular hydrogen bonds continues as a result of the simultaneous removal of hydroxyl groups and water removal reactions. After a 250 °C stabilization, the carbon yield at 900 °C was 42%. These findings highlight the importance of H3PO4 in accelerating the formation of an aromatic structure, which is critical for withstanding the high temperatures of subsequent carbonization and activation stages. Graphical abstract

Effect of solution concentration, process parameters and a second electric field on electrospun polyamide-11 fibers

The electrospinning process parameters for producing polyamide 11 (PA11) nanofibers using formic acid (FA) as the solvent were investigated. Key variables such as solution concentration, tip-to-collector distance, applied voltage, flow rate, and the introduction of a second electric field were optimized to produce uniform, bead-free nanofibers. Preliminary studies indicated that a 10% (w/v) PA11/FA solution concentration, a 25 kV voltage applied to the collector, a 12 cm tip-to-collector distance and a flow rate of 0.03 mL/min yielded the most consistent results in a conventional nozzle electrospinning setup. The effects of distance, voltage, and flow rate on fiber morphology were examined, with increased distance producing thinner fibers due to improved solvent evaporation, while higher voltages resulted in thicker fibers, highlighting the complex interplay between these parameters. Flow rate also played a significant role in fiber formation. The incorporation of charged metallic rings along the jet path, introducing a second electric field, further improved fiber uniformity. The most significant effect on the morphology of electrospun PA11 fibers was observed with rings connected to increasing voltage values, resulting in fibers with an average diameter of 145.7 ± 23.7 nm, minimal bead formation, and uniform circular cross-section. These optimized electrospinning parameters and the application of a second electric field show potential for improving fiber quality in applications such as filtration, textiles, and tissue engineering, contributing to a deeper understanding of PA11 electrospinning.

In vivo assessment of regional scleral stiffness by shear wave elastography and its association with choroid and retinal nerve fiber layer characteristics in high myopia.

To evaluate the posterior scleral stiffness of different regions in high myopic eyes and to explore its associations with macular choroidal and peripapillary retinal nerve fiber layer (pRNFL) thickness and vasculature. Thirty subjects with high myopic eyes and 30 subjects with low myopic eyes were included in this study. The elastic modulus of the macular and peripapillary sclera at the temporal, nasal, superior and inferior regions were determined via shear wave elastography (SWE). Optical coherence tomography and angiography (OCT/OCTA) centered on the fovea and optic disc was obtained by using a commercially available swept-source OCT/OCTA device. Built-in automated software was used to quantify macular subfovea choroidal vessel volume (SFCVV), macular subfovea choroidal thickness (SFCT) and pRNFL thickness. The SWE results demonstrated that high myopic eyes had significantly lower macular and peripapillary scleral elastic modulus than low myopic eyes (P < 0.001). The reduction in the elastic modulus was slightly greater in the temporal peripapillary region, followed by the superior peripapillary, inferior and nasal peripapillary regions (P > 0.05). The linear regression analysis demonstrated a significant association between the posterior scleral elastic modulus and SFCT and inferior pRNFL thickness (P < 0.001). High myopic eyes had weakened posterior scleral stiffness. The regional change in the elastic modulus was associated with the SFCT and inferior quadrant pRNFL thickness. This novel in vivo quantitative assessment of scleral stiffness via SWE may help to characterize the underlying pathologic mechanism of scleral biomechanics on choroid and pRNFL changes in high myopia. WHAT IS KNOWN : Previous studies reported significant choroid thickness and peripapillary nerve fiber layer thickness decrease in high myopia The scleral stiffness is weakened in myopic eyes WHAT IS NEW : Shear wave elastography (SWE) is a novel tool to detect posterior scleral biomechanics in myopic eyes in vivo Stiffness of the posterior sclera at macular and peripapillary regions is lower in high myopic than in low myopic eyes The posterior scleral stiffness is correlated with subfovea choroidal thickness and inferior quadrant peripapillary nerve fiber layer thickness.

In vivo imaging of mitochondrial function in normal, glaucoma suspect, and glaucoma eyes.

To investigate macula and optic nerve head (ONH) mitochondrial metabolic activity using flavoprotein fluorescence (FPF) in normal, glaucoma suspect (GS), and open-angle glaucoma (OAG) eyes we performed a cross-sectional, observational study of FPF in normal, GS, and OAG eyes. The macula and ONH of each eye was scanned and analyzed with a commercially available FPF measuring device (OcuMet Beacon, OcuSciences Inc., Ann Arbor, MI). One-way analysis of variance was used to compare macula and ONH FPF scores between groups. Linear regression models investigated the correlation between FPF scores and structural and functional parameters. We included 25 normal, 16 GS, and 54 OAG eyes. The average age in years ± SD for normal, GS, and OAG groups was 60.6 ±17.4, 67.8 ± 10.3, and 67.9 ± 11.6, respectively (P = 0.064). There was no significant difference in gender, race/ethnicity, visual acuity, and intraocular pressure between groups. OAG eyes had larger cup-to-disc ratio, thinner retinal nerve fiber and macula thicknesses, and worse visual field indices compared to normal and GS eyes (P ≤ 0.018). There was no significant difference in any FPF metric between the study groups in either the macula or the ONH, despite normalizing FPF data for structural differences between groups (e.g. retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness). In conclusion, no significant differences in metabolic activity as measured by FPF were found in macula and ONH FPF scores using the integrated clinician report generator between normal, GS, and OAG eyes. Further research is needed to evaluate the role of mitochondrial metabolic activity measurements in glaucoma.

Sex Differences in Aortic Valve Inflammation and Remodeling in Chronic Severe Aortic Regurgitation.

Background: Aortic regurgitation (AR) is more prevalent in male, although cellular and molecular mechanisms underlying the sex differences in prevalence and pathophysiology are unknown. Objectives: This study evaluates the impact of sex on aortic valve (AV) inflammation and remodeling as well as the cellular differences in valvular interstitial cells (VICs) and valvular endothelial cells (VECs) in patients with AR. Methods: A total of 144 patients (27.5% female) with severe chronic AR were included. AVs were analyzed by imaging, histological and molecular biology techniques (ELISA, RT-PCR). VICs and VECs isolated from patients with AR were characterized and further treated with transforming growth factor (TGF)-β. Results: Anatomically, male had smaller index aortic dimensions and greater AV thickness. Proteome profiler analyzes in AVs (n=40/sex) evidenced higher expression of inflammatory markers in male and that was further validated (interleukins, chemokines). Histological composition showed higher expression of inflammatory mediators and collagen thick fibers in AVs from male. Male VICs and VECs secreted higher levels of inflammatory markers than female cells. Interestingly, male VICs produced higher amounts of collagen type I and lower fibronectin and aggrecan, whereas male VECs secreted lower decorin. TGF-β exclusively enhanced inflammation in male VICs, and decorin and aggrecan in female VICs. Conclusion: Compared to male, AVs from female were thinner, less inflamed and fibrotic. VIC seem to be the key cell type responsible for the sex-differences. Valvular inflammation associated with an active remodeling process could be a key pathophysiological process involved in AR.

Unicuspid unicommissural aortic valves: A surgical pathology analysis.

The unicuspid unicommisural aortic valve is an uncommon congenital malformation that often manifests as stenosis with or without regurgitation in adults in their third to fifth decades of life. This report characterizes the morphological features of surgically excised unicuspid valves in adults with clinical correlation. Among the surgically excised aortic valves over a period of 10 years, the clinical data and morphological features of unicuspid aortic valves were analyzed. The patients were grouped by the type of valvular function. Pathological features noted were the shape of the orifice, the status of the commissure and raphe, presence of fibrous thickening, calcification, and other complications. Twenty-three UAVs, excised over a 10-year period, represented 4.16% of the excised diseased aortic valves. There was a male preponderance with a mean age of 47.7 years. Majority of the patients (22 cases) had moderate to severe stenosis with varying degrees of regurgitation, and the valvular disease had been clinically attributed to rheumatic heart disease, bicuspid aortic valve, or senile degenerative changes. Most of the valves (18) had been cut at their commissural regions, and 2 rudimentary commissures or raphes were seen in 21 valves. Cuspal fibrosis/calcification was often associated with complications like ulceration, hemorrhage, and bland vegetations. Aneurysm of the ascending aorta had been present in 1 patient. The unicuspid unicommisural aortic valve while rare is usually clinically classified with the more common, congenitally bicuspid aortic valve. Clinical or imaging diagnosis can be challenging since calcification may obscure the morphology creating difficulties in distinguishing such valves from other congenital or acquired valvular pathologies, especially in older patients. Often it is only the gross examination that leads to the differentiation as was our observation.

A novel approach to completely alleviate peripheral neuropathic pain in human patients: insights from preclinical data.

Neuropathic pain is a pervasive health concern worldwide, posing significant challenges to both clinicians and neuroscientists. While acute pain serves as a warning signal for potential tissue damage, neuropathic pain represents a chronic pathological condition resulting from injury or disease affecting sensory pathways of the nervous system. Neuropathic pain is characterized by long-lasting ipsilateral hyperalgesia (increased sensitivity to pain), allodynia (pain sensation in response to stimuli that are not normally painful), and spontaneous unprovoked pain. Current treatments for neuropathic pain are generally inadequate, and prevention remains elusive. In this review, we provide an overview of current treatments, their limitations, and a discussion on the potential of capsaicin and its analog, resiniferatoxin (RTX), for complete alleviation of nerve injury-induced neuropathic pain. In an animal model of neuropathic pain where the fifth lumbar (L5) spinal nerve is unilaterally ligated and cut, resulting in ipsilateral hyperalgesia, allodynia, and spontaneous pain akin to human neuropathic pain. The application of capsaicin or RTX to the adjacent uninjured L3 and L4 nerves completely alleviated and prevented mechanical and thermal hyperalgesia following the L5 nerve injury. The effects of this treatment were specific to unmyelinated fibers (responsible for pain sensation), while thick myelinated nerve fibers (responsible for touch and mechanoreceptor sensations) remained intact. Here, we propose to translate these promising preclinical results into effective therapeutic interventions in humans by direct application of capsaicin or RTX to adjacent uninjured nerves in patients who suffer from neuropathic pain due to peripheral nerve injury, following surgical interventions, diabetic neuropathy, trauma, vertebral disc herniation, nerve entrapment, ischemia, postherpetic lesion, and spinal cord injury.

Achilles tendon morphology adaptations in chronic post-stroke hemiparesis: a comparative analysis with neurologically intact controls.

In individuals with chronic post-stroke hemiparesis, slow walking speed is a significant concern related to inadequate propulsion of the paretic limb. However, an overlooked factor is this population's altered morphology of the Achilles tendon, which may compromise the propulsive forces by the paretic limb. This study aimed to explore changes in Achilles tendon morphology, including gross thickness and intra-tendinous collagen fiber bundle organization, following stroke-induced brain lesions. Fifteen individuals with chronic post-stroke hemiparesis (at least 6 months post-stroke) and 19 neurologically intact controls participated. Ultrasound imaging was used to evaluate Achilles tendon thickness and collagen organization in the paretic and non-paretic limbs of post-stroke participants, as well as in the right limb (control limb) of the neurologically intact control group. Compared to control individuals, the paretic limb in individuals post-stroke showed increased tendon thickness at the Achilles tendon insertion and 2 cm above it. The collagen fiber bundle at the Achilles tendon insertion of the paretic limb showed reduced organization compared to that in the control limb. Individuals post-stroke also exhibited slower walking speed, and increased plantarflexor muscle tone in the paretic limb compared to controls. In conclusion, individuals with chronic post-stroke hemiparesis demonstrated tendon thickening and collagen disorganization in the paretic limb, particularly at the insertion site of the Achilles tendon, likely due to an abnormal loading environment influenced by increased plantarflexor muscle tone, muscle co-activation, and muscle disuse and atrophy. These changes may increase tendon compliance, impair force transmission and propulsion, and contribute to slower walking speed. Addressing Achilles tendon integrity should be incorporated as a component of strategies to improve neuromuscular control in this population.

Comparative analysis of optic disc and macular microvasculature in children with anisometropic amblyopia before and after treatment.

To evaluate optic disc and macular microvasculature changes in children with anisometropic amblyopia before and after treatment. In all, 60 children with unilateral anisometropic amblyopia between the ages of 6 and 12 were randomly selected from the ophthalmology clinic of Fuyang People's Hospital, while 60 children with non-amblyopia in the same age range were randomly selected as a normal control group. The right eye was uniformly taken in the control group with at least 6 months of follow-up. Optical coherence tomography angiography (OCTA) was used to evaluate the macular vessel density of superficial capillary plexus (SCP) and deep capillary plexus (DCP), optic disc vascular density (VD), foveal avascular zone (FAZ) area, macular thickness, and retinal nerve fiber layer thickness (RNFLT). Before treatment, the vessel density of the optic disc, macular SCP and DCP in the amblyopic group was significantly lower than those in the fellow eyes and the control group (P < 0.05), while there were no statistically significant differences in the vessel densities of the optic disc, macular SCP and DCP between the amblyopic eyes, the fellow eyes, and the control group after treatment (P>0.05). Statistically significant negative correlations were found between the alterations of BCVA in amblyopic eyes and the alterations of the vessel densities of the optic disc, macular SCP and DCP in amblyopia eyes (P<0.05) except for superior nasal (SN) and inferior nasal (IN) regions of the optic disc radial peripapillary capillary, temporal and nasal regions of macular parafoveal SCP, nasal regions of macular parafoveal DCP and inferior regions of macular perifoveal DCP(P>0.05). Macular and optic disc vessel density in OCTA are lower in children with anisometropic amblyopia and tend to return to normal levels to a certain extent following treatment for amblyopia.

Long-range directional growth of neurites induced by magnetic forces.

The ability to control the growth and orientation of neurites over long distances has significant implications for regenerative therapies and the development of physiologically relevant brain tissue models. In this study, the forces generated on magnetic nanoparticles internalised within intracellular endosomes are used to direct the orientation of neuronal outgrowth in cell cultures. Following differentiation, neurite orientation was observed after 3 days application of magnetic forces to human neuroblastoma (SH-SY5Y) cells, and after 4 days application to rat cortical primary neurons. The direction of neurite outgrowth was quantified using a 2D Fourier transform analysis, showing agreement with the derived magnetic force vectors. Orientation control was found to be effective over areas >1cm2 using modest forces of ∼10 fN per endosome, apparently limited only by the local confluence of the cells. A bioinformatics analysis of protein expression in cells exposed to magnetic forces revealed changes to cell signaling and metabolic pathways resulting in enhanced carbohydrate metabolism, as well as the perturbation of processes related to cellular organisation and proliferation. Additionally, in cell culture regions where the measured force vectors converged, large (∼100 µm) SH-SY5Y neuroclusters loaded with nanoparticles were found, connected by unusually thick linear neurite fibres. This could suggest a magnetically driven enhancement of neurocluster growth, with the clusters themselves contributing to the local forces that direct outgrowth. Such structures, which have not been previously observed, could provide new insights into the development and possible enhancement of neural circuitry. STATEMENT OF SIGNIFICANCE: A magnetic force approach for directing outgrowth in neuronal cells over macroscopic areas is successfully demonstrated. Cells were incubated with magnetic nanoparticles which were sequestered into intracellular compartments. Permanent magnet arrays created local intracellular magnetic force vectors mediated via the internalized nanoparticles, which were found to precisely guide neurite orientation. Analysis of cellular protein expression suggested the mechanism for directed growth involved specific cell signaling and metabolic pathways. In addition, highly unusual straight and thick neural fibers were observed that connected large 'magnetic' spherical cell clusters. The results reported will advance nanotechnology and cell therapy for neuro-regeneration where magnetic forces could help to reconnect damaged neurons, or even build artificial neuronal architectures.

Association of ABO and Rh blood groups with retinal structural indices

Purpose: To determine the association between ABO and Rh blood groups with retinal structural indices including macular thickness and peripapillary retinal nerve fiber layer thickness.Methods: This cross‐sectional study was conducted using convenience sampling in a tertiary referral eye hospital in Tehran, Iran. Study participants were referred to the hospital laboratory to test their blood group. Ocular examinations were performed including measurement of visual acuity, auto‐refraction, subjective refraction, and slit‐lamp biomicroscopes. Retinal imaging was carried out using Spectral‐domain optical coherence tomography under dilated papillary conditions.Results: According to the multiple linear regression model, the global retinal nerve fiber layer thickness [coefficient: ‐3.05 (95% confidence interval: ‐5.30 to ‐0.74); p = 0.010] and retinal nerve fiber layer thickness in the superior [coefficient: ‐4.65 (95% confidence interval: ‐8.40 to ‐0.89), p &lt; 0.001] and inferior [coefficient: ‐4.00 (95% confidence interval: ‐7.81 to ‐0.19); p = 0.040] quadrants were significantly thinner in individuals with blood type B compared to those with other ABO blood groups. The average [coefficient: 12.69 (95% confidence interval: 4.12‐21.64); p = 0.004) and central [coefficient: 16.21 (95% confidence interval: 6.44‐25.97); p = 0.001) macular thicknesses were significantly thicker in AB group compared to other blood groups. The average macular thickness was significantly thinner in Rh+ compared to the Rh‐ group [coefficient: ‐8.33 (95% confidence interval: ‐15.4 to ‐1.25); p = 0.021].Conclusions: Retinal structural indices are related to blood groups implying a genetic linkage. Clinicians should consider blood groups in the clinical evaluation of retinal structural indices to avoid misdiagnoses. It is also recommended that the optical coherence tomography devices include the blood group in their databases.

Dimerization among multiple NAC proteins mediates secondary cell wall cellulose biosynthesis in cotton fibers

SUMMARYCotton fibers, essentially cellulosic secondary cell walls (SCWs) when mature, are the most important raw material for natural textiles. SCW cellulose biosynthesis determines fiber thickness and industrially important fiber quality parameters, such as fiber strength and fiber length. However, transcriptional regulatory networks controlling fiber SCW cellulose formation remain incomplete. Here, we identify eight NAC domain proteins (GhNACs) that are involved in fiber SCW cellulose synthesis. These eight GhNACs can form pairwise heterodimers that may act as dimers, or perhaps even as an octameric protein complex, to transactivate GhCesA expression. Moreover, heterodimerization of GhNACs can in different combinations synergistically activate GhCesA genes. Through our analyses of transcription factor—DNA and transcription factor—transcription factor interactions, we propose a multi‐layered transcriptional regulatory network in which the regulation of SCW cellulose biosynthesis in cotton fiber is mediated by multiple NAC protein dimers. These findings enhance our understanding of the roles of NAC proteins in SCW formation and offer new insights into fiber‐specific transcriptional regulatory mechanisms of cellulose synthesis.

Features of the microstructure of the quadriceps femoral muscle of broiler chickens of the smena-9 cross with various feeding diets

The article presents the results of studies of the histological and ultrastructural characteristics of the quadriceps femoral muscle of broiler chickens of the Smena-9 cross on the 35th day of postembryonic ontogenesis using feed additives (probiotic, prebiotic, sorbent) of domestic production in addition to the basic feeding diet.The work was implemented within the framework of the thematic task plan for the implementation of research works under the state order of the Ministry of Agriculture of the Russian Federation (Agreement No. 082-03-2023-238 dated 30.01.2023) on the topic: "Development of theoretical foundations and methodology for the practical use of morphological criteria in assessing the quality and safety of poultry products." It has been shown that against the background of the use of feed additives, an increase in the weight of chickens occurs. At the same time, the microstructure of the rectus head of the quadriceps femoris of birds of the control and experimental groups, while maintaining the general plan of structure (the presence of muscular and connective tissue components, bundle organization), is not the same. Based on studies using light and transmission electron microscopy, it was shown that the signs of morphological maturity of skeletal muscle tissue are most pronounced when using a probiotic, in the case of using a prebiotic and a sorbent, muscle fibers grow less synchronously, which is manifested by the variability of their thickness. The thickness of muscle fibers, their bundles, the state of the mitochondrial apparatus, the packing density of myofibrils and their thickness, the degree of development of endomysium and perimysium and the presence of white adipose tissue can be objective morphological and morphometric criteria for assessing the condition of muscle tissue, which correlates with the taste qualities of poultry meat. Data on the structural organization of the quadriceps muscle of the new domestic cross expand the theoretical base in the field of the myology of farm birds, including in terms of identifying morphological signs of the realization of genetic potential against the background of the use of different feeding diets in chicken rearing technology, which allows us to quickly assess the effectiveness of chicken rearing technology and predict an increase in productivity.

A mathematical model of plasmin-mediated fibrinolysis of single fibrin fibers.

Fibrinolysis, the plasmin-mediated degradation of the fibrin mesh that stabilizes blood clots, is an important physiological process, and understanding mechanisms underlying lysis is critical for improved stroke treatment. Experimentalists are now able to study lysis on the scale of single fibrin fibers, but mathematical models of lysis continue to focus mostly on fibrin network degradation. Experiments have shown that while some degradation occurs along the length of a fiber, ultimately the fiber is cleaved at a single location. We built a 2-dimensional stochastic model of a fibrin fiber cross-section that uses the Gillespie algorithm to study single fiber lysis initiated by plasmin. We simulated the model over a range of parameter values to learn about patterns and rates of single fiber lysis in various physiological conditions. We also used epifluorescent microscopy to measure the cleavage times of fibrin fibers with different apparent diameters. By comparing our model results to the laboratory experiments, we were able to: 1) suggest value ranges for unknown rate constants(namely that the degradation rate of fibrin by plasmin should be ≤ 10 s-1 and that if plasmin crawls, the rate of crawling should be between 10 s-1 and 60 s-1); 2) estimate the fraction of fibrin within a fiber cross-section that must be degraded for the fiber to cleave in two; and 3) propose that that fraction is higher in thinner fibers and lower in thicker fibers. Collectively, this information provides more details about how fibrin fibers degrade, which can be leveraged in the future for a better understanding of why fibrinolysis is impaired in certain disease states, and could inform intervention strategies.

Golgi pH elevation due to loss of V-ATPase subunit V0a2 function correlates with tissue-specific glycosylation changes and globozoospermia

Loss-of-function variants in ATP6V0A2, encoding the trans Golgi V-ATPase subunit V0a2, cause wrinkly skin syndrome (WSS), a connective tissue disorder with glycosylation defects and aberrant cortical neuron migration. We used knock-out (Atp6v0a2−/−) and knock-in (Atp6v0a2RQ/RQ) mice harboring the R755Q missense mutation selectively abolishing V0a2-mediated proton transport to investigate the WSS pathomechanism. Homozygous mutants from both strains displayed a reduction of growth, dermis thickness, and elastic fiber formation compatible with WSS. A hitherto unrecognized male infertility due to globozoospermia was evident in both mouse lines with impaired Golgi-derived acrosome formation and abolished mucin-type O-glycosylation in spermatids. Atp6v0a2−/− mutants showed enhanced fucosylation and glycosaminoglycan modification, but reduced levels of glycanated decorin and sialylation in skin and/or fibroblasts, which were absent or milder in Atp6v0a2RQ/RQ. Atp6v0a2RQ/RQ mutants displayed more abnormal migration of cortical neurons, correlating with seizures and a reduced O-mannosylation of α-dystroglycan. While anterograde transport within the secretory pathway was similarly delayed in both mutants the brefeldin A-induced retrograde fusion of Golgi membranes with the endoplasmic reticulum was less impaired in Atp6v0a2RQ/RQ. Measurement of the pH in the trans Golgi compartment revealed a shift from 5.80 in wildtype to 6.52 in Atp6v0a2−/− and 6.25 in Atp6v0a2RQ/RQ. Our findings suggest that altered O-glycosylation is more relevant for the WSS pathomechanism than N-glycosylation and leads to a secondary dystroglycanopathy. Most phenotypic and cellular properties correlate with the different degrees of trans Golgi pH elevation in both mutants underlining the fundamental relevance of pH regulation in the secretory pathway.

Results of assessing the dynamics of ophthalmological complications in chronic kidney disease patients after kidney transplantation

Objective. The study objective was to investigate the dynamics of opthalmological complications in the non-diabetic end-stage chronic kidney disease in patients after kidney transplantation.Material and methods. A long-term observation was conducted to assess the changes in morphofunctional parameters of eyes in patients of the study group (after kidney transplantation, n=135 (269 eyes)) and the comparison group (continued on hemodialysis, n=81 (162 eyes)) over 18 months. Both general and specialized ophthalmological investigation methods were employed.Results. The observation showed a positive trend in patients after kidney transplantation, which was manifested by reduced corneal and conjunctival calcification. In the comparison group, both an increase and decrease in qualitative signs of retinopathy were seen as based on optical coherence tomography data, while in the study group, most retinopathy signs decreased, indicating a positive trend possibly brought about by the kidney transplantation. Analysis of optical coherence tomography quantitative parameters showed an improvement in central choroidal thickness and retinal nerve fiber layer thickness in the study group.Conclusion. Kidney transplantation in patients with the non-diabetic end-stage chronic kidney disease leads to a reduction in ophthalmological complications both in the anterior eye segment (reduced corneal and conjunctival calcification) and in its posterior segment (improved optical coherence tomography retinal parameters).

Computational analysis of free-corner-induced failure of thick angle-ply composite laminates established upon a global-local model

The complex three-dimensional (3D) state of interlaminar stresses in the vicinity of a free corner in composite laminates brings about delamination, matrix cracking, and overall failure. This study focuses on devising a straightforward and efficient computational framework for analyzing the free-corner-induced failures in mechanically and thermally-loaded thick angle-ply composite laminates based on an innovative global-local finite element model. In so doing, the global region is dealt with by the first-order shear deformation theory, and the local sub-model region near the free corner is scrutinized using the 3D layer-wise theory. Distinctive risk parameters associated with the meso-level damage modes, including ply failure, delamination, and transverse matrix cracking are well-defined under the corresponding criteria. The precision of the model is ensured through verifications in which satisfactory alignment between the current outcomes and those of other available works in the literature substantiates the efficacy of the proposed approach. Furthermore, the impacts of the configuration parameters such as fiber orientation and thickness of plies upon the risk parameters are fully examined. It is found that, generally, by increasing the angle of fibers between two adjacent layers and diminishing the ply thickness, the composite laminate becomes more critical. The matrix cracking mode is dominated regarding the delamination and is in close agreement with the ply failure analysis. The proposed computational infrastructure, occasioning time and financial savings is valuable and enlightening for designing and manufacturing composite structures.

Gender differences in canine anterior chamber dimensions: Potential implications for primary angle-closure glaucoma.

This study aimed to explore anatomical differences in the aqueous humor (AH) outflow pathway between male and female dogs using ultrasound biomicroscopy (UBM). Clinical data were collected from 30 eyes of 30 dogs (15 males: 10 right eyes, 5 left eyes; and 15 females: 7 right eyes, 8 left eyes) treated at the Veterinary Medical Teaching Hospital of Chungbuk National University, South Korea, between August 2018 and February 2024. The study conducted an in-depth UBM examination, specifically observing peripheral anterior chamber depth (ACD), geometric iridocorneal angle (ICA), and angle-opening distance (AOD) alongside measurements of ciliary cleft width (CCW), length (CCL), and area (CCA), and assessed the longitudinal fibers of ciliary muscle thickness (Lf-CMT) and the longitudinal and radial fibers of ciliary muscle thickness (LRf-CMT) for gender-based differences. The study identified a significant sex difference in peripheral ACD, with females displaying shallower depths compared to males, potentially clarifying the higher incidence of glaucoma in female dogs. No significant gender differences were found in ICA, AOD, CC parameters, or ciliary muscle parameters measurements. This research uncovered that peripheral ACD is significantly shallower in females than in males, potentially indicating a risk factor that could contribute to the development of primary angle-closure glaucoma.

An in vivo evaluation of the safety and efficacy of using decellularized bovine parietal peritoneum membranes as dural substitutes.

The reconstruction of dura matter is a challenging problem for neurosurgeons. A number of materials for dural reconstruction have recently been developed, but some of them have poor biocompatibility, poor mechanical properties, and adverse effects. Bovine parietal peritoneum is a promising natural material for regenerative medicine and reconstructive surgery. In this study, we conducted an in vivo evaluation of the safety and efficacy of using decellularized bovine peritoneum membranes (BPMs) as natural dural substitutes in a rabbit model. The dural defects in mature New Zealand rabbits were studied. A BPM was sutured on the dural defect area of each animal. Autologous periosteum and collagen membranes (Lyoplant®) were used to facilitate a comparison with the BPMs. ELISA, histomorphological analysis, and hematological analysis were carried out to examine the safety and efficacy of using BPMs as dural substitutes. Our results showed that the BPMs demonstrated a deterioration rate that is suitable for gathering newly formed meningothelial tissue. The thickness and density of BPM fibers prevents resorption in the first few days after use as a plastic material, and the regeneration of the dura mater does not occur at an accelerated pace, meaning that the gradual formation of fibrous tissue prevents adhesion to the brain surface. It was observed that the BPM can integrate with the adjacent tissue to repair dural defects. Moreover, the transplantation of BPMs did not cause significant adverse effects or immunological responses, indicating the safety and good biocompatibility of the BPM. Thus, our in vivo study in a rabbit model showed that decellularized BPMs may represent a biocompatible natural material that can be used in cases requiring dura matter repair without significant adverse effects.

Anatomical and histological analyses of ankle plantar flexors: insights into connective tissue composition and muscle architecture.

The tibialis posterior (TP), flexor digitorum longus (FDL), and flexor hallucis longus (FHL) are muscles that contribute to the stability of foot and ankle movements, playing a crucial role in achieving optimal gait. However, a comprehensive examination of the anatomical characteristics and histological variances of each muscle has not been conclusively established. A total of 10 un-embalmed cadavers were dissected, and muscles from each cadaver were consistently harvested from the musculotendon junction. The ratio of collagen and elastic fibers was assessed through three immunohistological analyses, focusing on distinct histological characteristics in type I (slow twitch) and type II (fast twitch) fibers. Additionally, Ultrasonography was utilized to compare and analyze the thickness, fascicle angle, and muscle fiber length of each muscle. Concerning the relative proportion of elastic fibers to collagen, the TP exhibited the highest collagen content (21.9 ± 0.30%, mean ± standard deviation), while the FHL had the highest elastic fiber proportion (48.4 ± 0.44%). The TP predominantly comprised slow type muscle fibers (36.88 ± 0.83%), whereas the FHL contained a higher density of fast type muscle fibers (32.46 ± 4.02%). US analysis indicated that the thickness of the TP was relatively greater (2.0 ± 0.2mm) compared to the FDL (1.2 ± 0.1mm) and FHL (1.1 ± 0.1mm). Additionally, the fascicle length was notably longer in the TP (25.6 ± 4.1mm). Our anatomical and histological findings indicate that the tibialis posterior (TP) is the thickest with a significant physiological angle and a high collagen content. This characteristic enables the TP to provide stability by transmitting a constant force to the calf. On the other hand, the flexor hallucis longus (FHL) exhibits the highest elastic fiber content, confirming its ability to exert instantaneous, swift, and powerful force.