Topographic Features Research Articles

Parameterization of Shear‐To‐Strain Ratio Used in Finescale Parameterization

AbstractThe Gregg‐Henyey‐Polzin (GHP) finescale parameterization is widely employed to infer turbulent mixing when microstructure measurements are unavailable. However, the strain‐only GHP scaling is the only option when shear information is lacking, in which case the shear‐to‐strain ratio (Rω) is commonly treated as a constant. Since Rω has been reported to vary spatiotemporally, using a fixed value of Rω might result in a significant bias in inferring turbulent mixing. In this study, we present a global map of Rω, based on the microstructure database contributed by the Climate Process Team on internal wave‐driven ocean mixing, which covers the Indian, Pacific, and Atlantic oceans across both high and low latitudes. Then, we propose a parameterization of Rω by considering buoyancy frequency, Coriolis frequency, and topographic features. Compared to the GHP scaling with constant Rω, the turbulent dissipation rate values inferred from the GHP scaling with parameterized Rω are more accurate. In this manner, this study provides a reference for choosing optimal Rω when using the strain‐only GHP scaling to explore turbulent mixing in the open ocean.

Topographic Controls on Pyroclastic Density Current Hazard at Aluto Volcano (Ethiopia) Identified Using a Novel Zero‐Censored Gaussian Process Emulator

AbstractAluto volcano (Central Ethiopia) displays a complex, hybrid topography, combining elements typical of caldera systems (e.g., a central, flat caldera floor) and stratovolcanoes (e.g., relatively high and steep, radial flanks, related to eruptions occurring clustered in space). The most recent known eruptions at Aluto have commonly generated column‐collapse pyroclastic density currents (PDCs), a hazardous phenomenon that can pose a significant risk to inhabited areas on and around the volcano. In order to analyze and quantify the role that Aluto's complex topography has on PDC hazard, we apply a versatile probabilistic strategy, which merges the TITAN2D model for PDCs with a novel zero‐censored Gaussian Process (zGP) emulator, enabling robust uncertainty quantification at tractable computational costs. Results from our analyses indicate a critical role of the eruptive vent location, but also highlight a complex interplay between the topography and PDC volume and mobility. The relative importance of each factor reciprocally depends on the other factors. Thus, large PDCs (≥0.1–0.5 km3) can diminish the influence of topography over proximal regions of flow propagation, but PDCs respond to large‐ and small‐scale topographic features over medial to distal areas, and the zGP captures processes like PDC channelization and overbanking. The novel zGP can be applied to other PDC models and can enable specific investigations of PDC dynamics, topographic interactions, and PDC hazard at many volcanic systems worldwide. Potentially, it could also be used during volcanic crises, when time constraints usually only permit computation of scenario‐based hazard assessments.

Unpacking the ‘supply-utilization-demand’ interplay: Keys to multifunctional sustainability in rural China

Sustainable rural development is predicated on a delicate balance between rural territorial functions and ecological constraints. While various functions can catalyze economic growth in rural settings, aligning them with inherent ecological variables is essential. An exhaustive analysis of Beijing’s Pinggu District elucidated specific supply-demand thresholds and evaluated the adaptability of current utilization within these boundaries, culminating in a novel optimization strategy. Notably, while locals place significant emphasis on production functions, the area’s topography and soil characteristics present palpable challenges to achieving these goals. We discovered that ‘shackle type’ predominantly characterize individual rural territorial functions, while ‘diversified weak function optimization type’ define multifunctional aspects, showcasing varied development paths and uncovering potential strategies for sustainable improvement. This study contributes a groundbreaking perspective to sustainable rural development, offering key insights and strategic recommendations for policy formulation.

Relation between the soil erosion cover management factor and vegetation index in semi-arid basins

The cover management factor is one of the main five factors that is used within the universal soil loss equation to reflect the effect of cropping and management practices on soil erosion rates. It is determined through tables and equations derived in tropical and European conditions, which are not suitable for semi-arid regions with different climate, topography, and soil characteristics. Therefore, this study considers al-Arish basin in Sinai Peninsula, Egypt as a semi-arid study area to generate a cover management factor’s equation in terms of the Normalized Difference Vegetation Index using hydrological modeling and satellite images processing. To verify the proposed equation, it was applied to the Derna catchment in Libya and compared with European and tropical ones with respect to the hydrological outputs. Statistical analysis indicates that the proposed equation determines the cover management factor more accurately than those developed for tropical or European regions, as the correlation coefficient between the cover management factor and the hydrological results was 0.71, while it was about 0.20 for the European and tropical, equations, also the degree of agreement between the proposed equation’s results and the hydrological simulation was 0.768 while it was 0.001 and 0.02 for the tropical and European equations respectively. By utilizing the newly developed equation, the soil erosion can be estimated more accurately for the semi-arid regions, and a better understanding of the relation between the vegetation cover and soil erosion can be drawn.

Analysis of Land Use and Land Cover Change Detection for Indore District of Malwa Plateau Region Using Supervised Machine Learning

The main aim of this work is to find out LULC classes for the Indore region. For the last seven years, Indore has been crowned the cleanest city in India according to the latest ranking of 2023. In the Indian state of Madhya Pradesh, the city and district of Indore are situated on the southern edge of the Malwa plateau. The municipalities of the Indore district majorly cover Manpur, Depalpur, Goutampura, Mhow, Hatod, Betma, Rau and Sanwer, with an area of approximately 3900 square kilometers. In contrast, Indore covers a land area of approximately 530 square kilometres. It is in charge of the nation’s slow but steady industrialization and population growth found in the last three decades. The city was much smaller and had a far smaller population thirty years ago. However, to evaluate the changes and decide on Indore city's future planning, Indore has taken over responsibility for the city's economic activities in recent years. New appropriate patterns should be recommended based on local factors like topography characteristics. The satellite image with multiple spectrums was used for the investigation. ArcGIS is based on pixel-by-pixel supervised classification using the maximum likelihood approach of Landsat satellite images from 2003 and 2023. The ground area, agriculture, and urbanization are linked to the LULC features. The various categories of classified land use and land cover features include the area of built-up regions, water bodies, cropland, forest, and barren land taken to predict the broad changes. Remotely sensed Landsat 5 images of 2003 and 8 images of 2023 were utilized to identify changes to accomplish this goal. This work clarifies the comparison of LULC classes for the Indore region.

Fully unsupervised wear anomaly assessment of aero-bearings enhanced by multi-representation learning of deep features

The assessment of wear anomalies using vision-based techniques is crucial for automated inspections of machine health conditions. Given the diversity of worn anomalies and the time-consuming nature of labeling, recent advancements in unsupervised anomaly detection have focused on comparing extracted features with those of normal images. However, this approach faces significant challenges in constructing a comprehensive comparison sample database and extracting distinctive features from worn surfaces with varying degrees of severity. To overcome these limitations, we introduce a fully unsupervised anomaly assessment method that detects anomalies solely based on single-bearing images, without the need for unworn samples. This approach eliminates the requirement for a comparison sample database by constructing an implicit feature database from the single-bearing surfaces using pre-trained convolutional neural networks and dimensionality reduction strategies. Additionally, to address the limited differentiability of wear characteristics, we develop a feature refinement strategy that incorporates multi-representation learning and topographical distribution characteristics of worn surfaces. By integrating the statistics of the refined feature database with uncertainty distribution-based normal feature weights, we construct an anomaly distribution map. This map enables us to assess the anomaly degree of a single-bearing effectively. To validate our method, we conducted experiments using real aero-engine bearings. The results demonstrate that our proposed approach can accurately assess anomaly degrees without pre-prepared comparison samples, achieving a detection performance of 90%, which fulfills the requirements for wear anomaly assessment.

Volcanic Glass as a Proxy for Paleotopography Suggests New Features in Late-Miocene Oregon

Volcanic glass has been used extensively as a paleoaltimeter. Deuterium (2H) concentrations in glass have been found to be stable over geologic timescales, making δ2H (also known as δD) a reliable proxy for ancient water chemistry. However, continued work revolves around better understanding how different factors affect preserved water in volcanic ash. Here, we analyze δD in the Rattlesnake Tuff (RST), a widespread ca. 7 Ma ash-flow tuff, and create a paleoisoscape to assess variations in δD across Oregon during that time. To this end, 16 ash samples were collected across central and eastern Oregon from various flow units within the RST. Samples were analyzed for δD using a temperature conversion elemental analyzer (TC/EA) connected to a mass spectrometer and elemental composition using a scanning electron microscope (SEM). We compared the isotopic results to modern water and published ancient water proxy data to better constrain changes in climate and topography across Oregon throughout the Neogene. We also estimated wt. % H2O by calculating excess (non-stoichiometric) oxygen from SEM elemental data. We did not observe significant variations in δD among the flow units from single locations, nor was there a significant relationship between the prepared glass shard composition and wt. % H2O or δD, supporting the use of volcanic glass as a reliable paleoenvironmental indicator. Our results show significant spatial variation in δDwater values of RST, ranging from −107‰ to −154‰. δD values of ancient glass were similar to modern water near the Cascade Mountains but became relatively negative to the east near the inferred eruptive center of the RST, suggesting that a significant topographic feature existed in the vicinity of the RST eruptive center that has since subsided.

Judgment criteria for significant wind speed-up regions in natural complex terrain

Flashover incidents due to wind-induced motion of overhead power line components are a not uncommon phenomenon during very strong winds, e.g. typhoons, and an important contributing factor is the speed-up effect caused by small-scale topographic features. In this study, wind speed-up ratios and significant speed-up regions in natural complex terrain are comprehensively analyzed from three perspectives: analysis of landform characteristics of flashover locations, Computational Fluid Dynamics (CFD) simulation, and wind tunnel experiments. Through the analysis of flashover locations, judgment criteria based on the elevation coefficient of variation are proposed to attempt to identify significant speed-up regions in natural complex terrain. Wind tunnel experiments and CFD simulations are conducted to analyze the wind speed-up ratios in 12 wind directions for both a small isolated mountainous area and a large continuous mountainous area. The significant speed-up regions are determined by consolidating the speed-up ratios from all 12 wind directions. The reliability of the judgment criteria is then validated. The results confirm that significant speed-up ratios are predominantly concentrated at the edges of mountainous areas, particularly at peaks and high ridges around areas with larger elevation coefficient of variation. These regions largely coincide with the locations where flashover incidents mainly occurred and the results from wind tunnel experiments and CFD simulations. In summary, the clearly identified significant speed-up regions include (1) small isolated mountainous areas; (2) peaks and high ridges around areas with larger elevation coefficient of variation within large continuous mountainous areas, and the higher crests within these regions. Based on these findings, the study suggests that wind speed-up ratios in design standards should be amplified in the vicinity of these regions to enhance safety measures.

Environmentally friendly swift and perfect extraction procedures for analysing the phytochemistry and proximate nutritional biochemistry of biomaterial processed from Avicennia marina leaves

Conventional extraction methods have mislaid their best possible performance because of the slow extraction process using demand in inexperienced and innovative technologies. Concerning this view, several eco-friendly novel techniques alienate to develop by us for the entire extraction of nutrients and phytocompounds from plant sources. The specific organic, inorganic chemical compounds have been explored using ultra sonication and GC-MS assisted techniques. The results are evident to facilitate the ultrasonic and GC-MS supported extraction descent that is less solvent consumed, green analytical methods suitable for complete speedy bioactive compounds drawing out. This study has revealed the occurrence of nutrients, phytochemicals, with biological value, and also the GC-MS analysis exposed 20 peaks through 20 individual chemical compounds, and all the compounds are deliberated as energetic medicinal bioactive compounds. Likewise the FE-SEM is used to find out the topographical characteristics of biomaterial and the FTIR analysis.

Current State of Microsurgical Treatment of Aneurysms of the Ophthalmic Segment of the Internal Carotid Artery

Current State of Microsurgical Treatment of Aneurysms of the Ophthalmic Segment of the Internal Carotid Artery

Geomorphic signatures of neotectonic activity along the Western Andean Front in the Chilean Andes (35°S to 37°S)

AbstractCharacterizing neotectonic activity along mountain fronts in active orogens is the key to better understanding trajectories of landscape evolution, climatic‐tectonic couplings and natural hazards. One such prominent mountain front is the Western Andean Front (WAF), which defines the boundary between two main physiographic units along the Chilean Andes (15°S to 39°S): the Central Depression and Principal Cordillera. This study analyses the geomorphic imprints of neotectonic fault activity in the WAF between 35°S and 37°S. We used several topographic metrics, including the mountain‐front sinuosity index (Smf), the valley floor width‐to‐height ratio (Vf) and the stream length‐gradient (SL) index to gain information about the regional distribution of deformation patterns and its relative tectonic activity for distinctive segments. In addition, a raster map combining rock strength (RS) and mean annual precipitation (MAP) allowed discriminating lithology‐climate vs. tectonics influence on SL anomalies from catchments spanning from the main deformation zone to the regional drainage divide. We use the local relief and swath profiles to quantify the incision and transient state of mountain fronts to evaluate the geomorphic response to tectonic and/or climatic input. Our analysis highlights significant variations from north to south, delineating two distinct segments with different topographic, geomorphic and geometric fault characteristics. These segments are indented at approximately 36°S. From north to south, there is a segment with an inactive thrust front with a primarily climate‐driven fluvial response over long timescales and a second segment with a transient state adjusting to relatively high uplift rates. Morphometric data analysis, DEM‐based morpho‐structural maps, geological maps and previous research support the interpretation of two sets of neotectonic faults: (1) NNE‐striking reverse faults with a dextral slip component and (2) NW‐striking sinistral slip faults, likely a response to deformation partitioning caused by oblique subduction on a continental margin.

Sedimentary Record of the middle Cretaceous uplift across the Gangdese magmatic arc system in Southern Tibet

AbstractSedimentary basins adjacent to subduction‐related continental arcs provide important archives for deciphering the intricate history of convergent plate margins. The east‐west trending Gangdese magmatic arc was one of the most predominant topographic features located at the southern margin of Tibet before the arrival of the Indian plate. However, the detailed Cretaceous growth and evolution across the arc system remains ambiguous. Stratigraphy of the adjacent Xigaze forearc basin provides a well‐preserved and well‐exposed record of the tectonic and magmatic evolution of the arc throughout the Cretaceous period. We report new stratigraphic, sedimentological, geochronological, and provenance analyses of the Quarry Ridge sandstone in the Xigaze forearc basin along with compiled zircon U‐Pb ages (n = 9674) and Lu‐Hf isotopic signatures (n = 3389) from the Gangdese arc, the Xigaze forearc basin, and the Linzhou retroarc foreland basin to reconstruct the Early to middle Cretaceous magmatism and uplift of the Gangdese arc and concurrent sedimentary responses within both basins. Exhumation of the arc initiates at around 113 Ma suggested by arc detritus first arriving in both basins. Another episode of inferred uplift occurs at around 108 Ma, which resulted in coarse‐grained sedimentation in adjacent basins, preventing Central Lhasa detritus from reaching the Xigaze forearc basin further south and a facies and provenance change within the Linzhou basin. Finally, a third episode at around 101 Ma is reflected by deposition of the progradational Quarry Ridge clastic succession and marks the initiation of a substantial coarse‐grained depositional stage in the Xigaze forearc basin. Our study emphasizes the connection between coarse‐grained deposition in the forearc basin and arc magmatism and uplift. This study also provides an orogen‐scale assessment of the history of arc magmatism, uplift, and sedimentation across the Gangdese magmatic arc system, which supports interpretations that Tibet was already characterized by complex and substantial topographic relief during the Cretaceous before the collision between the Indian and Eurasian plates.

Features of topography and macroscopic structure of the digestive organs of the Yemeni chameleon (Chamaeleo calyptratus)

The relevance of this study is conditioned by the lack of detailed information on the structure and topography of the digestive organs of the Yemeni chameleon (Chamaeleo calyptratus). The purpose of this study was to find out the specific features of changes in body weight, topography, and structure of the digestive organs of the Yemeni chameleon, to determine their morphometric parameters in animals from 1 day to 1 year of age. The research material included the tongue, oesophagus, stomach, intestines, liver, and pancreas of chameleons of different sexes of 9 age groups. The data obtained were processed by one-factor analysis of variance (ANOVA). According to the topography, macroscopic structure and surface of the mucous membrane, there are three intestines in the small intestine: duodenum, jejunum, and ileum, and two intestines in the large intestine: the colon with a diverticulum and the rectum, which passes into the cloaca. A feature of the serous membrane of the chameleon intestine is that it is coloured black by melanin. From 1 day to 1 year of age, the body weight of chameleons increased 185.9 times, the snout-vent length (SVL) increased 6.7 times, the length of the digestive tract increased 3.8 times, and the ratio of the length of the digestive tract to SVL decreased from 3.2 to 1.8 times. The most intensive increase in body weight and SVL occurred during the second and third months of life. The relative length of the small intestine in chameleons of different age groups was 65.1- 81.6%, with the longest part being the jejunum. The increase in the morphometric parameters of the stomach, intestines, liver, and pancreas was asynchronous. The most pronounced changes in their relative weight were determined in animals of 2-3 months of age. The obtained materials supplement and clarify the information on the topography and structure of the digestive organs of the Yemeni chameleon, and therefore they will be useful in X-ray and ultrasound examination during veterinary manipulations

Geologic context of Chang'e-6 candidate landing regions and potential non-mare materials in the returned samples

Our understanding of the lunar farside from orbital remote sensing is limited by the lack of ground-truth constraints from returned samples. China's Chang'e-6 (CE-6) mission plans to land at the southern rim of the Apollo basin in the South Pole-Aitken basin on the lunar farside and return ∼2 kg samples. In this study, we conduct analyses on the local geological context of the CE-6 candidate landing regions, with a focus on the non-mare ejecta. The CE-6 candidate landing region has been divided into three subunits. According to our analyses, the northeastern subunit is adjacent to the lowest elevation (and one of the highest excavation depth) of this region where the materials from the deepest crust may exist. The northwestern subunit is affected by the magnesian ejecta from young crater. Returning these non-mare ejecta will provide key insights into the magnesian lithologies that occurred in the lunar farside, whose petrogenesis is long debated. As for the southern light plains unit, a topographic positive feature (unofficially termed as Mons White) located at the west of the light plains is identified in this work. Three scenarios were proposed for its origin: (1) A volcanic complex built on special magmatism in the SPA basin; (2) Remnants of the central uplift of an ancient impact basin; (3) Target surface folded and uplifted by the Apollo basin impact event. Gradual lithological variations in the Mons White are discovered. The White crater has likely ejected materials with these gradual lithologies into the CE-6 candidate landing regions. The Orientale basin ejecta also exists on the light plains. These non-mare materials, if could be sampled by the CE-6 mission, will significantly help refine the lunar chronostratigraphic system from the pre-Nectarian/Aitkenian to the late Imbrian. Thus, we suggest that landing on the southern light plains will achieve the maximum scientific outcomes for the CE-6 mission, from a perspective of sample diversity.

Assessment of Site Effects and Numerical Modeling of Seismic Ground Motion to Support Seismic Microzonation of Dushanbe City, Tajikistan

In the territory of Dushanbe city, the capital of Tajikistan, detailed geological and geophysical data were collected during geophysical surveys in 2019–2020. The data comprise 5 microtremor array measurements, 9 seismic refraction tomography profiles, seismological data from 5 temporary seismic stations for standard spectral ratio calculations, 60 borehole datasets, and 175 ambient noise measurements. The complete dataset for Dushanbe was used to build a consistent 3D geologic model of the city with a size of 12 × 12 km2. The results of the seismological and geophysical surveys were compared and calibrated with borehole data to define the boundaries of each layer in the study area. The Leapfrog Works software was utilized to create a 3D geomodel. From the 3D geomodel, we extracted six 12 km long 2D geological cross-sections. These 2D geological cross-sections were used for 2D dynamic numerical modeling with the Universal Distinct Element Code software to calculate the local seismic response. Finally, the dynamic numerical modeling results were compared with the amplification functions obtained from the seismological and ambient noise data analysis. The 2D dynamic numerical modeling results allowed a better assessment of the site effects in the study area to support seismic microzonation and the determination of local peak ground acceleration changes in combination with regional seismic hazard maps. In addition, our results confirm the strong seismic amplification effects noted in some previous studies, which are attributed to the influence of local topographic and subsurface characteristics on seismic ground motions.

Climate change adaptation and smallholder farmers welfare: Empirical evidence from the Sahelian Region of West Africa

Global climate change has threatened sustainable agricultural growth over the years, severely affecting food sufficiency and the livelihood of farmers. The Climate-Smart Agricultural Technologies (CSAT), as a form of adaptation, offer pathways for mitigating the negative effect of climate change on crop producers in developing countries. This study uses cross-country (Mali and Niger) cross-sectional data to examine the welfare (proxied by crop sales revenue and income) impact of multiple adoptions of CSAT on smallholder farm households. To control for potential endogeneity that leads to bias estimates, we employ the multinomial endogenous treatment effect (METE) model, complemented with the inverse probability weighted regression adjustment (IPWRA) for the analysis. The result reveals that household (education, location, and assets) and plot (plot size, plot topography, and soil fertility) characteristics, institutional factors (farmer-based organization, access to formal credit, and extension service) and crop disease shock significantly influence different combinations of CSAT adoption. The impact estimates show that adopting joint combinations of CSAT leads to higher crop sales revenue and income among the farmers in most cases. These findings suggest that the adoption of CSAT as a package should be encouraged and disseminated in the West Africa Sahel region. Moreover, some sociodemographic and institutional factors such as education, credit access, farmer-based organizations, and extension services could be strengthened for easy and rapid adoption of CSAT by smallholder farmers, which subsequently improves their economic welfare.

Satellite Image Analysis Approach for Identifying Flood Impacts in DKI Jakarta

Jakarta, as the capital city of Indonesia, is one of the major cities in the world that is inevitably affected by disasters resulting from climate change. The topographical characteristics of Jakarta, situated in a low-lying area, make it susceptible to floods during the rainy season. In 2020, Jakarta experienced a rainfall of 377 mm/day, marking the highest precipitation during the period of 1866 to 2020. To mitigate the impact of flood disasters, the availability of flood distribution data is crucial. The process of identifying flood distribution utilizes Sentinel-1 radar satellite imagery with the Normalized Difference Sigma-Naught Index (NDSI) method. NDSI is sensitive to open water bodies due to changes in land surface properties during floods. Based on NDSI analysis, the flood distribution in DKI Jakarta was identified on January 2, 2020, covering 17,38% of the total area of DKI Jakarta, which is 661,52 km2.

Remote Quantification of Soil Organic Carbon: Role of Topography in the Intra-Field Distribution

Soil organic carbon (SOC) measurements are an indicator of soil health and an important parameter for the study of land-atmosphere carbon fluxes. Field sampling provides precise measurements at the sample location but entails high costs and cannot provide detailed maps unless the sampling density is very high. Remote sensing offers the possibility to quantify SOC over large areas in a cost-effective way. As a result, numerous studies have sought to quantify SOC using Earth observation data with a focus on inter-field or regional distributions. This study took a different angle and aimed to map the spatial distribution of SOC at the intra-field scale, since this distribution provides important insights into the biophysiochemical processes involved in the retention of SOC. Instead of solely using spectral measurements to quantify SOC, topographic and spectral features act as predictor variables. The necessary data on study fields in South-East England was acquired through a detailed SOC sampling campaign, including a LiDAR survey flight. Multi-spectral Sentinel-2 data of the study fields were acquired for the exact day of the sampling campaign, and for an interval of 18 months before and after this date. Random Forest (RF) and Support Vector Regression (SVR) models were trained and tested on the spectral and topographical data of the fields to predict the observed SOC values. Five different sets of model predictors were assessed, by using independently and in combination, single and multidate spectral data, and topographical features for the SOC sampling points. Both, RF and SVR models performed best when trained on multi-temporal Sentinel-2 data together with topographic features, achieving validation root-mean-square errors (RMSEs) of 0.29% and 0.23% SOC, respectively. These RMSEs are competitive when compared with those found in the literature for similar models. The topographic wetness index (TWI) exhibited the highest permutation importance for virtually all models. Given that farming practices within each field are the same, this result suggests an important role of soil moisture in SOC retention. Contrary to findings in dryer climates or in studies encompassing larger areas, TWI was negatively related to SOC levels in the study fields, suggesting a different role of soil wetness in the SOC storage in climates characterized by excess rainfall and poorly drained soils.

Liquefied capsules containing nanogrooved microdiscs and umbilical cord-derived cells for bone tissue engineering

Background Surface topography has been shown to influence cell behavior and direct stromal cell differentiation into distinct lineages. Whereas this phenomenon has been verified in two-dimensional cultures, there is an urgent need for a thorough investigation of topography’s role within a three-dimensional (3D) environment, as it better replicates the natural cellular environment. Methods A co-culture of Wharton’s jelly-derived mesenchymal stem/stromal cells (WJ-MSCs) and human umbilical vein endothelial cells (HUVECs) was encapsulated in a 3D system consisting of a permselective liquefied environment containing freely dispersed spherical microparticles (spheres) or nanogrooved microdiscs (microdiscs). Microdiscs presenting 358 ± 23 nm grooves and 944 ± 49 nm ridges were produced via nanoimprinting of spherical polycaprolactone microparticles between water-soluble polyvinyl alcohol counter molds of nanogrooved templates. Spheres and microdiscs were cultured in vitro with umbilical cord-derived cells in a basal or osteogenic medium within liquefied capsules for 21 days. Results WJ-MSCs and HUVECs were successfully encapsulated within liquefied capsules containing spheres and microdiscs, ensuring high cellular viability. Results show an enhanced osteogenic differentiation in microdiscs compared to spheres, even in basal medium, evidenced by alkaline phosphatase activity and osteopontin expression. Conclusions This work suggests that the topographical features present in microdiscs induce the osteogenic differentiation of adhered WJ-MSCs along the contact guidance, without additional differentiation factors. The developed 3D bioencapsulation system comprising topographical features might be suitable for bone tissue engineering approaches with minimum in vitro manipulation.

Topographical features of the formation of outflow tracts with the use of spongy allo-drainages in glaucoma

PURPOSE. Improving the results of the operation and achieving its reliability in secondary glaucoma, including refractory glaucoma, can be done using a non-biodestructible allograft drainage with spongy structure fabricated by Alloplant® technology.METHODS. Experimental and morphological studies conducted in the Russian Eye and Plastic Surgery Center showed that the allogeneic spongy biomaterial used for anti-glaucoma sponge drainage surgery is gradually replaced by loose tissue with a porous structure, similar to trabecular, forming a new drainage system. During the operation, the proximal part of the drainage is inserted through the excised drainage zone in the anterior chamber angle (ACA). The distal part is tucked into the suprachoroidal space through a linear incision in the scleral bed.RESULTS. The newly created topography of the ACA after sponge drainage operation with the use of allogeneic biomaterial features not only the expansion of the ACA profile, but also the replacement of the excised part of the drainage zone with biomaterial after sinus trabeculectomy (STE) and elimination of retention of the intraocular fluid (IOF) outflow. Ultrasound biomicroscopy (UBM) performed at various times after antiglaucoma surgery showed that the microtubule system preserved. Optical coherence tomography (OCT) of the ACA demonstrates the location of the drainage in the long-term follow-up.CONCLUSION. Antiglaucoma operation with the use of allogeneic biomaterial with spongy structure promotes the formation of trabecula-like tissue in the ACA, eliminates retention of IOF outflow, and reduces the risk of scleroscleral and sclero-conjunctival adhesions.