Lens Biometry in Congenital Lens Deformities: A Swept-Source Anterior Segment OCT Analysis

Aims: To investigate the lens biometric parameters in congenital lens deformities, using a novel technique of swept-source anterior segment optical coherence tomography (SS-ASOCT).Methods: This prospective study included patients with microspherophakia (MSP), coloboma lentis (CL), and posterior lenticonus (PL). For this cohort, 360-degree high-resolution lens images were obtained using the latest SS-ASOCT (CASIA2, Tomey Corp, Nagoya, Japan). The lens biometric parameters were calculated by the CASIA2 built-in software for anterior lens radius (ALR), posterior lens radius (PLR), anteroposterior distance (APD), anterior chamber depth (ACD), equatorial diameter (Eq Dia), rear projection length (RPL), and maximum diameter of the lesion (MDL).Results: This study included two eyes each with MSP and CL and one eye with PL. The lens of MSP was spherical and posteriorly dislocated, with decreased ALR and PLR, Eq Dia, but increased APD. In patients with CL, the coloboma was isolated, bilateral, inferior, and located toward the maldeveloped ciliary body. High astigmatism was mainly lenticular, and this was calculated by the ALR and PLR. Regarding the site of coloboma, a significant decrease in ALR was observed, while the PLR and APD were not affected. The PL eyes had a cone-shaped protrusion of the posterior lens surface with a subtle cataractous region around the apex. An extremely high posterior surface curvature was observed with a mean PLR of 1.67 mm. The RPL and MDL were about 1.80 and 0.4 mm, respectively, which were homogenous at different sections.Conclusions: The CASIA2 is a valuable option for in vivo crystalline lens measurement for congenital lens deformities, enabling the accurate diagnosis and providing illuminating insights into the pathogenesis of MSP, CL, and PL

FAST Discovery of a Long H i Accretion Stream toward M106

We report the discovery of a possible accretion stream toward a Milky Way–type galaxy M106 based on very deep H i imaging data with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The accretion stream extends for about 130 kpc in projection length and it is similar to the Magellanic stream in many respects. We provide unambiguous evidence based on the stream morphology, kinematics and local star formation activity to show that the H i gas is being accreted onto the disk of M106. Such a long continuous flow of gas provides a unique opportunity to probe the circumgalactic medium (CGM) and reveals how the gas stream traverses the hot halo and CGM, and eventually reaches the galaxy disk. The source of the stream appears to be from M106's satellite galaxy NGC 4288. We argue that the stream of gas could be due to the tidal interaction with NGC 4288, or with a high speed encounter near this system. Close to the position of UGC 7356 the stream bifurcates into two streams. The second stream may be gas tidally stripped from UGC 7356 or due to an interaction with UGC 7356. Our results show that high-sensitivity H i imaging is crucial in revealing low column density accretion features in nearby galaxies.

Peculiar aspects of cracking in prestressed reinforced concrete T-beams

In order to study the cracking of prestressed reinforced concrete T-shaped beam structures, the authors planned and carried out a full-scale experiment with five variable factors. The following factors were chosen as variable factors: the relative span of the shear, the ratio of the table overhang width to the thickness of the beam rib, the ratio of the table overhang thickness to the working height of the beam section, the coefficient of transverse reinforcement, the level of prestressing in the working reinforcement. The article describes the cracking process and the destruction of test beams. It was found that the loading level of an opening of inclined cracks is 53% larger than the loading level of a normal crack opening. Mathematical models of bending moments and transverse forces of cracking were built using the “COMPEX” software. Also, the mathematical models of the crack opening width and the projection length of a dangerous inclined crack were obtained. These models are based on the experimental data. Analysing the obtained models, the complex influence of variable factors on the main parameters of crack formation and crack resistance was established. In particular, it was found that the prestress level in the working reinforcement has the greatest effect on the bending moment of cracking. In this case, the value of the shear force of cracking significantly depends on both the prestressing level in the reinforcement and the relative span of the shear. On the basis of the experimental data, the empirical expression is obtained for determining the projection of a dangerous inclined crack for prestressed reinforced concrete T-shaped beams. The resulting equation can be used to calculate a shear reinforcement.

Jaya algorithm based optimum design of reinforced concrete retaining walls under dynamic loads

In this study, the optimum dimensioning of a reinforced concrete retaining wall that meets the safety conditions under static and dynamic loads in terms of cost has been performed using Jaya algorithm, which is one of the metaheuristic algorithms. In the optimization process, reinforced concrete design rules and ground stress, sliding and overturn tests have been determined as design constraints for the safe design of the retaining wall. While 5 cross-section dimensions of the retaining wall are defined as the design variable, the objective function is targeted as the total cost per unit length of the retaining wall. In the study, optimum results are also presented by examining the changes of the toe projection length of the retaining wall, which is one of the design variables, narrowing between 0.2-10 m. The design variables minimizing the objective function were found via Jaya algorithm that have single-phase. In addition to achieving optimum dimensioning results in terms of safety and cost with the optimization method used as a result of the reinforced concrete design made by applying the rules of the regulation on buildings to be constructed in earthquake zones, the change in cost in seismic and static conditions was examined.

Visual outcomes of surgical and conservative treatment in children with small posterior polar cataracts and posterior lenticonus

AIM: To compare the visual outcomes of children with small (≤3 mm) posterior polar cataracts (PPC) and posterior lenticonus who had cataract extraction surgery with the visual outcomes of those who were managed conservatively. METHODS: Children who initially had small PPC and posterior lenticonus who were followed up over 1-year period were retrospective reviewed in the study. Patients receiving surgery were compared with those receiving conservative therapy. The axial length, keratometry, refraction, best-corrected visual acuity (BCVA), and strabismus measurements were recorded. Lens morphology, i.e., the location, size, and depth of the cataract lesion, was measured with a Scheimpflug imaging system. To help control for baseline differences in the groups, patients were matched with controls by propensity score methodology. RESULTS: The study evaluated 60 patients (30 in the surgery group and 30 in the conservative therapy group) after matching by propensity score. Patients who underwent cataract surgery showed greater BCVA improvements (0.36±0.24 logMAR) than patients who were treated without surgery (0.22±0.26 logMAR; P=0.036). Surgery was effective in patients with a rear projection length (RPL) less than 1.0 mm and a pretreatment BCVA worse than 0.52 logMAR. CONCLUSION: Children with small PPC and posterior lenticonus who undergo cataract surgery experience greater BCVA improvements than those managed conservatively. Certain patients presenting with a RPL less than 1.0 mm and a pretreatment BCVA of 0.52 logMAR or worse may benefit from surgery.

Association of aerobic glycolysis with the structural connectome reveals a benefit–risk balancing mechanism in the human brain

Aerobic glycolysis (AG), that is, the nonoxidative metabolism of glucose, contributes significantly to anabolic pathways, rapid energy generation, task-induced activity, and neuroprotection; yet high AG is also associated with pathological hallmarks such as amyloid-β deposition. An important yet unresolved question is whether and how the metabolic benefits and risks of brain AG is structurally shaped by connectome wiring. Using positron emission tomography and magnetic resonance imaging techniques as well as computational models, we investigate the relationship between brain AG and the macroscopic connectome. Specifically, we propose a weighted regional distance-dependent model to estimate the total axonal projection length of a brain node. This model has been validated in a macaque connectome derived from tract-tracing data and shows a high correspondence between experimental and estimated axonal lengths. When applying this model to the human connectome, we find significant associations between the estimated total axonal projection length and AG across brain nodes, with higher levels primarily located in the default-mode and prefrontal regions. Moreover, brain AG significantly mediates the relationship between the structural and functional connectomes. Using a wiring optimization model, we find that the estimated total axonal projection length in these high-AG regions exhibits a high extent of wiring optimization. If these high-AG regions are randomly rewired, their total axonal length and vulnerability risk would substantially increase. Together, our results suggest that high-AG regions have expensive but still optimized wiring cost to fulfill metabolic requirements and simultaneously reduce vulnerability risk, thus revealing a benefit–risk balancing mechanism in the human brain.

Predictability of cortico-cortical connections in the mammalian brain

Despite a five-order magnitude range in size, the mammalian brain exhibits many shared anatomical and functional characteristics that should translate into cortical network commonalities. Here we develop a framework employing machine learning to quantify the degree of predictability of the weighted interareal cortical matrix. Data were obtained with retrograde tract-tracing experiments supplemented by projection length measurements. Using this framework with consistent and edge-complete empirical datasets in the macaque and mouse cortex, we show that there is significant amount of predictability embedded in the interareal cortical networks of both species. At the binary level, links are predictable with an Area Under the ROC curve of at least 0.8 for the macaque. At the weighted level, strengths of the medium and strong links are predictable with at least 85-90% accuracy in mouse and 70-80% in macaque, whereas weak links are not predictable in either species. These observations suggest that the formation and evolution of the cortical network at the mesoscale is to a large extent, rule-based, motivating further research on the architectural invariants of the cortical connectome.

Typical features of morphometric parameters of the mandible in adults

Objective: to develop a classification of mandibular forms and to study typical features of the morphometric characteristics of this bone in adults. Materials and methods. The study was conducted on 150 lower jaws of adults. To determine the shape of the lower jaw, four morphometric parameters were measured: angular width, projection length from the corners, branch height, smallest branch width, and three morphometric indexes were introduced: 1 - the long-length longitudinal index of the lower jaw; 2 - longitude latitudinal index of the body of the lower jaw; 3 - latitudinal-altitude index of the branches of the lower jaw. According to these indices, 9 groups of jaws with different shapes were identified. In these groups, the values of 35 morphometric parameters of the body and branches of the lower jaw were studied. Results. It was found that statistically significant differences (p <0.05) between the groups of jaws, determined by the value of the altitude-longitude index of the lower jaw and the longitude-latitude index of the body of the lower jaw, exist between the same morphometric parameters: angular width, projection length from the corners and chin angle , and most of the morphometric parameters of the body and branches of the lower jaw do not statistically significantly differ between the extreme forms (dolicho- and brachi, lepto- and eurimandibular). There are statistically significant differences between the jaw groups, systematized by the latitude-altitude index of the branch of the lower jaw (p <0.05) for most of the studied indicators of the branch of the lower jaw: branch height, smallest branch width, notch width, notch angle, base of the coronoid process , the base of the condylar process, the distance from the front edge of the lower jaw branch to the opening of the lower jaw, the distance from the notch of the lower jaw to the opening of the lower jaw, the distance from the angle of the lower jaw to the opening of the lower jaw. It has been proved that in the lower jaws with a hypsiramimandibular form, the values of the smallest branch width, the base length of the coronoid and condylar processes, as well as the distance from the front edge of the branch to the opening of the lower jaw are significantly smaller, however, the values of the branch height, notch angle, notch width, notch distance the angle of the lower jaw to its opening is larger compared to the platyramimandibular form (p˂0.05). Conclusion. The greatest number of differences in the value of morphometric parameters is observed during the systematization of the lower jaw according to the shape of its branch. This can be explained by the fact that it is under the direct influence of the masticatory muscles, performing not only supporting, protective, but also motor function.

Mechanical force regulates tendon extracellular matrix organization and tenocyte morphogenesis through TGFbeta signaling

Mechanical forces between cells and extracellular matrix (ECM) influence cell shape and function. Tendons are ECM-rich tissues connecting muscles with bones that bear extreme tensional force. Analysis of transgenic zebrafish expressing mCherry driven by the tendon determinant scleraxis reveals that tendon fibroblasts (tenocytes) extend arrays of microtubule-rich projections at the onset of muscle contraction. In the trunk, these form a dense curtain along the myotendinous junctions at somite boundaries, perpendicular to myofibers, suggesting a role as force sensors to control ECM production and tendon strength. Paralysis or destabilization of microtubules reduces projection length and surrounding ECM, both of which are rescued by muscle stimulation. Paralysis also reduces SMAD3 phosphorylation in tenocytes and chemical inhibition of TGFβ signaling shortens tenocyte projections. These results suggest that TGFβ, released in response to force, acts on tenocytes to alter their morphology and ECM production, revealing a feedback mechanism by which tendons adapt to tension.