Junction Density Research Articles

OCT Angiography Features of Neovascularization as Predictive Factors for Frequent Recurrence in Age-Related Macular Degeneration

To investigate the features of neovascularization (NV) in eyes with neovascular age-related macular degeneration using optical coherence tomography angiography (OCTA) according to the treatment interval of intravitreal aflibercept injection (IVI). Retrospective, interventional, comparative case series. Patients with type 1 NV treated with the "pro re nata" regimen after 3 loading IVI were classified into 2 groups based on the numbers of treatments during 12months, specifically a stable group who required fewer than 2 injections and an unstable group who required more than 3 injections. Quantitative features of OCTA including NV area, NV length, NV density, endpoint density (open-ended vessels per unit length), junction density (vessel junction per unit length), lacunarity, and largest vessel caliber were compared between the 2 groups. Among 71 eyes, 38 and 33 eyes were classified into the stable and unstable groups, respectively. The unstable group had higher endpoint densities (stable vs unstable: 2.72 vs 3.18; P= .03) and higher levels of lacunarity (0.177 vs 0.211; P= .028). The area, density, length of NV, junction density, and largest vessel caliber were not different between the 2 groups (P= .057, P= .184, P= .062, P= .160, and P= .473, respectively). Endpoint density was correlated with the unstable group in both univariate and multivariate analyses (P= .004, P= .002, respectively). A predictive model with an endpoint index demonstrated a sensitivity of 93.75% and a negative predictive value of 89.47% for the unstable group. The characteristics of NV in eyes of exudative age-related macular degeneration with type 1 NV were different according to treatment requirements. Identifying the features of NV on OCTA might be helpful for predicting clinical outcomes and optimal treatment intervals.

“Strain-annealed” grain boundary engineering process investigated in Hastelloy-X

The mechanisms responsible for microstructure evolution during “strain-annealed” grain boundary engineering in Hastelloy-X have been investigated. GBE-quantifying parameters such as Σ3n density and fraction, triple junction density and fraction have been utilized to quantify the extent of GBE in the processed microstructures. “Strain-annealed” GBE process favors the formation of Σ3 boundaries through dissociation mechanism. When the amount of strain/cycle is high, the change in microstructure is limited and most of the Σ3 boundaries are remnant annealing twins from the initial microstructure. When the amount of strain/cycle decreases, more grain boundary migration takes place and majority of Σ3 boundaries start integrating into the GB network through dissociation mechanism. AGG is found to take place under special conditions: when (i) the dislocation density stored in the microstructure is low and (ii) the fraction of Σ3 boundaries that are integrated into the general grain boundary network is high. It is the preferential growth advantage of CSL boundaries that leads to abnormal grain growth.

Quantitative predictions of maximum strain storage in shape memory polymers (SMP)

Shape memory polymers (SMPs) are dynamic materials able to recover previously defined shapes when activated by external stimuli. The most common stimulus is thermal energy applied near thermal transitions in polymers, such as glass transition (Tg) and melting (Tm) temperatures. The magnitude of the geometrical changes as well as the amount of force and energy that a SMP can output are critical properties for many applications. While typically deformation steps in the shape memory cycles (SMC) are performed at temperatures well above thermal transitions used to activate shape changes, significantly greater amounts of strain, stress, and mechanical energy can be stored in Tg-based SMPs when deformed near their Tg. Since maximum shape memory storage capacity can be appraised by evaluating the viscoelastic length transitions (VLTs) in a single dynamic mechanical analysis (DMA) experiment, this study correlates VLTs with the measured storage capacities obtained from stress-strain experiments for a broad range of well-defined crosslinked acrylates, epoxies, and polyurethanes. This systematic approach allows for assessment of crosslink/junction density (νj), viscoelasticity, and chemical composition effects on maximum deformability, and enables predictions of the magnitude of shape memory properties across a wide variety of polymers. These studies demonstrate that the maximum storable strain (ε-storemax) can be accurately predicted using junction density (νj) and shape memory factor (SMF), the latter accounting for the contribution of chemical makeup.

Finite element modelling of discontinuous action potential propagation in larval zebrafish and human cardiac tissue

Recently the larval zebrafish has emerged as a model organism which is used to assist in the studies of human cardiac electrophysiology. Although they share many similar electrophysiological characteristics, it has been found that the conduction velocity (CV) of action potential (AP) propagation in larval zebrafish heart is up to two orders of magnitude smaller than in the adult mammalian heart. To address this difference, we have developed three dimensional discrete models of larval zebrafish ventricular fibres (LZVF) in order to simulate AP propagation, taking into account the cellular nature of the tissues and intercellular conduction via gap junctions. Since our ultimate goal is to simulate a whole larval zebrafish heart, we have used the phenomenological Fitzhugh Nagumo (FHN) equations to describe transmembrane currents, and manually adjusted the FHN parameters, to fit published AP shapes for larval zebrafish ventricular cells. This has the benefit of reduced computational load compared to approaches based on biophysical ion current models. We have created models for 48 and 72 h post fertilisation LZVF tissue using published AP and cell size data for zebrafish embryos and used mammalian values for passive electrical parameters. Using the gap junction resistivity per myocyte as an adjustable parameter, we were able to obtain CVs in both of our LZVF models which agree with experimental observations. In order to validate our approach, we have applied it to a human ventricular fibre (HVF) model similar in structure and parameters to other models of the mammalian heart, but adjusting the FHN parameters to fit published AP shapes for human ventricular cells. We find good agreement with the human models. The gap junction resistivities used in the LZVF models are significantly higher than in the HVF case and are consistent with a lower density of gap junctions connecting cells.

Different subchondral trabecular bone microstructure and biomechanical properties between developmental dysplasia of the hip and primary osteoarthritis

ObjectiveDevelopmental dysplasia of the hip (DDH) is recognized as a frequent cause of secondary osteoarthritis (OA). The purpose in this study was to compare structural and biomechanical properties of subchondral trabecular bone ​and its relationship with cartilage damage between patients with DDH and patients with primary hip OA. MethodsForty-three femoral head specimens obtained from patients who underwent total hip arthroplasty [DDH, n ​= ​17; primary OA, n ​= ​16; and normal control (NC), n ​= ​10] were scanned by microcomputed tomography and analyzed by individual trabecula segmentation to obtain the microstructural types of subchondral trabecular bone. The biomechanical properties were analyzed by micro–finite element analysis, and cartilage damage was evaluated by histology. The linear regression analysis was used to indicate the association between microstructures, biomechanical property, and articular cartilage. ResultsThe DDH group showed the lowest total bone volume fractions (BV/TV) and plate BV/TV in the three groups (p ​< ​0.05). There were also different discrepancies between the three groups in plate/rod trabecular number, plate/rod trabecular thickness, trabecular plate surface area/trabecular rod length, and junction density with different modes (plate–plate, rod–rod, and plate–rod junction density). The micro–finite element analysis, histology, and linear regression revealed that the subchondral trabecular bone in the DDH group had inferior biomechanical properties ​and cartilage damage of patients with DDH was more serious with different subchondral trabecular bone microstructures. ConclusionOur findings detected deteriorating subchondral trabecular bone microstructures in patients with DDH. The mass and type of subchondral trabecular bone play a key role in mechanical properties in DDH, which might be related to cartilage damage. The translational potential of this articleOur findings suggested that changes of subchondral trabecular bone play a critical role ​in DDH progression and that the improvement on subchondral trabecular bone may be a sensitive and promising way in treatment of DDH.

Solution-Processed Carbon Nanotube Buckypapers for Foldable Thermoelectric Generators.

Freestanding single-walled carbon nanotube (SWCNT) buckypapers with thicknesses of ∼30 μm are fabricated using a simple bar-coating process. The Seebeck coefficient and electrical conductivity of the SWCNT buckypapers are affected by the composition of the dispersion solvent mixture. The maximum p-type power factor of a SWCNT buckypaper is 411 ± 13 μW m-1 K-2. The inverse relationship between the Seebeck coefficient and electrical conductivity of the SWCNT buckypapers may be explained by the number density of junctions between the SWCNT bundles. Using the SWCNT buckypapers, which can be cut, folded, and pasted, a foldable thermoelectric generator is fabricated. The thermoelectric generator folded to an area of 2.25 cm2 exhibits a maximum power of 10.3 μW at a vertical temperature difference of 30 K.

Morphological bases for intestinal paracellular absorption in bats and rodents.

Flying mammals present unique intestinal adaptations, such as lower intestinal surface area than nonflying mammals, and they compensate for this with higher paracellular absorption of glucose. There is no consensus about the mechanistic bases for this physiological phenomenon. The surface area of the small intestine is a key determinant of the absorptive capacity by both the transcellular and the paracellular pathways; thus, information about intestinal surface area and micro-anatomical structure can help explain differences among species in absorptive capacity. In order to elucidate a possible mechanism for the high paracellular nutrient absorption in bats, we performed a comparative analysis of intestinal villi architecture and enterocyte size and number in microchiropterans and rodents. We collected data from intestines of six bat species and five rodent species using hematoxylin and eosin staining and histological measurements. For the analysis we added measurements from published studies employing similar methodology, making in total a comparison of nine species each of rodents and bats. Bats presented shorter intestines than rodents. After correction for body size differences, bats had ~41% less nominal surface area (NSA) than rodents. Villous enhancement of surface area (SEF) was ~64% greater in bats than in rodents, mainly because of longer villi and a greater density of villi in bat intestines. Both taxa exhibited similar enterocyte diameter. Bats exceeded rodents by ~103% in enterocyte density per cm2 NSA, but they do not significantly differ in total number of enterocytes per whole animal. In addition, there is a correlation between SEF and clearance per cm2 NSA of L-arabinose, a nonactively transported paracellular probe. We infer that an increased enterocyte density per cm2 NSA corresponds to increased density of tight junctions per cm2 NSA, which provides a partial mechanistic explanation for understanding the high paracellular absorption observed in bats compared to nonflying mammals.

Efficient detecting of TNT molecules using palladium nanoparticles/ cross shape pores like structure porous silicon

A set of porous silicon PSi samples with different cross-shaped pores like structures are successfully synthesized by using double successive wet anisotropic etching process: KOH wet chemical process and laser-assisted etching (LAE) process. Four different forms of palladium nanoparticles are deposited on PSi substrate to fabricate PdNPs/PSi heterostructures. Surface-enhanced Raman scattering (SERS)-active PdNPs/PSi heterostructures are fabricated and investigated for detecting Trinitrotoluene (TNT) molecules. Dipping plating process of PSi in 0.05 M concentration of PdCl2 solution at room temperature for 15 min is used to assemble spread of surface morphologies PdNPs layer over PSi. The results show that the SERS of heterostructures for TNT molecules expos strong reliance on the density of hot-spot junctions more than the local surface plasmonic of PdNPs. Analytical Enhancement factor (EF) of the Raman signal is varied according to the formed density of hot spots regions.

Canalicular Junctions in the Osteocyte Lacuno-Canalicular Network of Cortical Bone.

The osteocyte lacuno-canalicular network (LCN) is essential for bone remodeling because osteocytes regulate cell recruitment. This has been proposed to occur through liquid-flow-induced shear forces in the canaliculi. Models of the LCN have thus far assumed that it contains canaliculi connecting the osteocyte lacunae. However, here, we reveal that enlarged spaces occur at places where several canaliculi cross; we name these spaces canalicular junctions. We characterize them in detail within mice cortical bone using synchrotron nanotomography at two length scales, with 50 and 130 nm voxel size, and show that canalicular junctions occur at a density similar to that of osteocyte lacunae and that canalicular junctions tend to cluster. Through confocal laser scanning microscopy, we show that canalicular junctions are widespread as we have observed them in cortical bone from several species, even though the number density of the canalicular junctions was not universal. Fluid flow simulations of a simple model system with and without a canalicular junction clearly show that liquid mass transport and flow velocities are altered by the presence of canalicular junctions. We suggest that these canalicular junctions may play an important role in osteocyte communication and possibly also in canalicular fluid flow. Therefore, we believe that they constitute an important component in the bone osteocyte network.

Vascular maturity of type 1 and type 2 choroidal neovascularization evaluated by optical coherence tomography angiography.

PurposeVessel maturation is considered to proceed by pruning branches resulting in less branching vessels. This study investigated the vessel junction densities of type 1 and type 2 choroidal neovascularizations (CNVs) using optical coherence tomography angiography (OCTA).MethodsWe collected consecutive data from treatment-naïve eyes diagnosed with typical age-related macular degeneration (AMD). The OCTA images with CNV were analyzed to calculate vessel areas, vessel lengths, and vessel junction densities.ResultsOf 60 eyes in 60 patients, type 1 CNV diagnoses had been made in 40 eyes, and type 2 CNV in 20 eyes. We found no significant difference in vessel areas between type 1 CNV and type 2 CNV (type 1 CNV, 0.44 ± 0.37 mm2; type 2 CNV, 0.37 ± 0.48 mm2), and no significant difference in vessel lengths (type 1 CNV, 18.24 ± 15.96 mm; type 2 CNV, 16.13 ± 21.45 mm). However, the vessel junction density of type 1 CNV was significantly lower than that of type 2 CNV by 16.0% (P = 0.008).ConclusionOCTA revealed that the vessel junction densities of type 1 CNVs were lower than those of type 2 CNVs, suggesting type 1 CNV vessels are more mature than type 2 CNV vessels.

Urban redevelopment at the block level: Methodology and its application to all Chinese cities

Urban redevelopment is the reconstruction or upgrade of current urban built-up areas; it revitalizes old towns and contributes to sustainable development. This paper proposes a methodological framework that integrates open-source street networks and point-of-interest data and aims to identify and evaluate urban redevelopment at the block level from the perspective of urban form and function. It is found that (1) urban blocks can be categorized into eight groups regarding the spatial form of road junctions that have emerged within them over time, and blocks of each group share common features that can be automatically identified; (2) there are more blocks that have been morphologically redeveloped than functionally redeveloped, and the two types of redevelopments also significantly overlap with one another; and (3) the evaluation of urban redevelopment identification results presents a high accuracy rate that verifies the validity of the proposed framework. Based on the identification results, the impact factors of urban redevelopment are explored on both the inter- and intracity levels. The intercity analysis indicates that Chinese cities with a lower administrative level, lower urbanization rate, and higher density of road junctions tend to be associated with a higher proportion of urban redevelopment. Meanwhile, the intracity analysis attempts to determine which kinds of urban blocks are more likely to undergo urban redevelopment, which are found to be the blocks with lower points of interest density, a smaller distance to city centers, higher transit accessibility, a higher land use mixed index, and larger size.

OR03-6 Tibial and Radial Bone Structure as Assessed by HRpQCT May Explain Differences in Peripheral Skeletal Integrity and Fracture Risk Across the Weight Spectrum That Cannot Be Explained by Areal BMD Alone

No study has investigated tibial or radial bone structure or estimated strength by high-resolution peripheral quantitative CT (HRpQCT) in women across the weight spectrum. We studied 139 women, 17-46yo: 1) anorexia nervosa (AN n=74), 2) lean controls (HC n=33) and 3) overweight/obese (OB n=32). All HC and OB were eumenorrheic. Areal BMD (aBMD) and appendicular lean mass (ALM) were measured by DXA; cortical and trabecular volumetric BMD (vBMD), cortical thickness, cortical porosity, failure load (finite element analysis) and trabecular plate parameters (individual trabecular segmentation) at the tibia and radius by HRpQCT. Mean age was similar among groups. Mean BMI was 17.7 ± 2.1 vs 22.6 ± 1.4 vs 35.2 ± 3.2 kg/m2 (p<0.0001). Mean aBMD Z-scores were lowest in AN, intermediate in HC and highest in OB (PA spine -1.6 ± 1.3 vs -0.5 ± 0.8 vs 0.5 ± 0.8; total hip -1.0 ± 1.1 vs 0.2 ± 0.9 vs 1.0 ± 0.9; radius -0.6 ± 1.0 vs 0.1 ± 0.9 vs 0.7 ± 0.9; p<0.0001). At the tibia and radius, mean trabecular vBMD and failure load were lowest in AN, intermediate in HC and highest in OB, while mean trabecular plate bone volume fraction, plate number density and plate-plate junction density were lower in AN (p<0.05) and similar in HC and OB. Mean cortical vBMD and cortical porosity were similar among groups, but cortical thickness was lower in AN vs OB (p<0.01). There was a quadratic relationship between BMI and trabecular vBMD, failure load and all plate parameters (R=0.40-0.67, p<0.0001), such that the higher the BMI, the smaller the increase in these parameters. In contrast, ALM had a consistent positive linear relationship with these parameters (R=0.37-0.78, p<0.0001). IGF-1 levels were positively associated with tibial and radial estimated strength and trabecular structure (R=0.21-0.37, p<0.05). Duration of amenorrhea in AN was negatively associated with radial estimated strength and trabecular structure (R= -0.25- -0.37, p<0.01). Despite similar mean aBMD at all sites, those with a history of fracture (n=57) had lower mean tibial and radial trabecular vBMD and plate-plate junction density; lower mean tibial cortical vBMD, plate bone volume fraction and plate number; and higher mean tibial cortical porosity compared to those without (n=72) (p<0.05). Conclusions: Trabecular bone structure and estimated strength were generally higher with greater weight, but the incremental increase was smaller as BMI increased into the obese range. Cortical bone parameters generally did not increase with greater weight. This suggests that the skeleton in women with obesity may not be able to fully adapt to an increased weight load. Muscle mass and IGF-1 levels were positive, and duration of amenorrhea a negative, determinant of bone structure and estimated strength. Across the weight spectrum, tibial and radial bone structure by HRpQCT may explain differences in peripheral skeletal integrity and fracture risk that cannot be explained by aBMD alone.

Use of Open Data to Assess Cyclist Safety in London

This study develops a predictive model for cycling collisions in London. Specifically, the effects of bus lanes, parking or loading facilities, and multilane roads on the risk of cycling collisions are considered. To the best of the authors’ knowledge, this is the first such predictive collision model that develops covariates to measure the characteristics of different types of road infrastructure within zones. A kernel density estimator is used to identify 90 collision hotspots. Each hotspot is populated with information regarding the highway infrastructure within it. A multiple linear regression model tests for the statistical significance of the infrastructure variables. Bus lanes, multilane roads, and 30-mph speed limits are found to affect cycle collision counts, whereas junction density has the largest impact on collision density. Speed limits of 20 mph affect collision counts to a lesser degree than 30 mph, indicating potential safety improvement from reducing speed limits. One-way roads are found to reduce the risk of collisions, along with the provision of priority junctions. This infers that other junction types, such as roundabouts and signalized junctions, present a higher collision risk. The models produce conflicting results on parking or loading provision. The models are expanded to include sociodemographic variables, such as population and employment. The combined model offers no performance improvement over the infrastructure-only model, although a potential link between public transport provision and reducing cycle collisions warrants further investigation.

Deteriorating subchondral bone microstructure accelerates osteoarthritis progression in developmental dysplasia of the hip than in primary osteoarthritis

Purpose: Developmental dysplasia of the hip (DDH) is recognized as a frequent cause of secondary osteoarthritis (OA). Compared with primary hip OA, DDH often causes changes in the anatomical hip structure and leads to more severe symptoms and imaging manifestations. However, the subchondral bone microstructure and biomechanical property of patients with DDH has not been previously evaluated. Thus, we aimed to analyze the subchondral bone and its association with articular cartilage damage in DDH and primary hip OA through a novel technique for microstructural observation, the individual trabecula segmentation (ITS) analysis. We hypothesized that the changes of subchondral bone in DDH could partly account for the acceleration of OA progression. Methods: Thirty-three femoral head specimens obtained from patients underwent total hip arthroplasty (DDH, n=17; primary OA, n=16) were scanned using Micro-CT, and the selected volume of interest (VOI) was processed by ITS to obtain the microstructural types of subchondral bone. The biomechanical property of VOI was analyzed by micro-finite element analysis (μFEA) and cartilage damage was evaluated by the histology. Moreover, the linear regression analysis was utilized to indicate the association between microstructures, biomechanical property and articular cartilage. Results: Compared with the OA group, the DDH group showed lower total bone volume fractions (BV/TV) and plate bone volume fractions (pBV/TV) by the ITS-based analysis (p<0.05). The plate-to-rod ratio was significantly higher in the OA group than in the DDH group (p<0.05). Remarkably, there were varying degrees of discrepancy between the two groups in pTb.N/rTb.N (plate/rod trabecular number), pTb.Th/rTb.Th (plate/rod trabecular thickness), pTb.S/rTb.L (plate surface area and rod length) and P-P Junc.D/R-R Junc.D/P-R Junc.D (junction density with different trabecular modes). Moreover, the μFEA, histology and linear regression analysis revealed that the subchondral bone in patients with DDH had inferior biomechanical property, and the cartilage damage was severer than patients with OA due to the different subchondral bone microstructures. Conclusions: In this study, our findings detected a less connected, more widely separated trabecular network and deteriorating subchondral bone microstructure in patients with DDH than those with primary OA. The mass and type changes of subchondral bone may contribute to worsening biomechanical property and cartilage damage, thus leading to the acceleration of OA progression in patients with DDH.

A humidity‐sensing composite microfiber based on moisture‐induced swelling of an agarose polymer matrix

Herein, we present a humidity sensing microfiber based on an agarose polymer as a hydrophilic matrix and carbon nanotubes (CNT) as conducting fillers. The humidity‐dependent resistance is the key property of the composite microfiber as a humidity sensor. The composite microfiber composed of the agarose matrix swells or contracts depending on environmental humidity, leading to changes in junction density between the carbon nanotube conducting fillers inside the fiber. Moreover, adsorption of water molecules on the CNT filler could further increase the resistance of the microfiber sensor. The real‐time resistance monitoring of the microfiber shows reliable and reversible response to the repetitive changes in relative humidity with reasonable response rate. The tensile strength test confirms the mechanical robustness of the composite microfiber. The fabrication process is facile and presumably scalable. Such a practical fiber sensor could be readily used as a humidity‐sensing component in smart textile and wearable devices. POLYM. COMPOS., 40:3582–3587, 2019. © 2019 Society of Plastics Engineers

Enhanced coupling through π-stacking in imidazole-based molecular junctions.

We demonstrate that imidazole based π-π stacked dimers form strong and efficient conductance pathways in single-molecule junctions using the scanning-tunneling microscope-break junction (STM-BJ) technique and density functional theory-based calculations. We first characterize an imidazole-gold contact by measuring the conductance of imidazolyl-terminated alkanes (im-N-im, N = 3-6). We show that the conductance of these alkanes decays exponentially with increasing length, indicating that the mechanism for electron transport is through tunneling or super-exchange. We also reveal that π-π stacked dimers can be formed between imidazoles and have better coupling than through-bond tunneling. These experimental results are rationalized by calculations of molecular junction transmission using non-equilibrium Green's function formalism. This study verifies the capability of imidazole as a Au-binding ligand to form stable single- and π-stacked molecule junctions at room temperature.

Metallic-semiconducting junctions create sensing hot-spots in carbon nanotube FET aptasensors near percolation

Easily fabricated random network carbon nanotube field-effect transistors (CNT-FETs) have benefitted from improved separation techniques to deliver CNTs with current formulations providing at least 99% semiconducting tube content. Amongst the most promising applications of this device platform are electronic biosensors, where the network conduction is affected through tethered probes such as aptamers which act as molecular scale electrostatic gates. However, the prevailing assumption that these biosensor devices would be optimized if metallic tubes were entirely eliminated has not been examined. Here, we show that metallic-semiconducting junctions in aptasensors are sensing hotspots and that their impact on sensing is heightened by the CNT network's proximity to percolation. First, we use a biased conducting AFM tip to gate a CNT-FET at the nanoscale and demonstrate that the strongest device response occurs when gating at metallic-semiconducting junctions. Second, we resolve the target sensitivity of an aptasensor as a function of tube density and show heightened sensitivity at densities close to the percolation threshold. We find the strongest sensing response where the 1% of metallic tubes generate a high density of metallic-semiconducting junctions but cannot form a percolated metallic path across the network. These findings highlight the critical role of metallic tubes in CNT-FET biosensor devices and demonstrate that network composition is an important variable to boost the performance of electronic biosensors.

Macro scale modelling of cortical spreading depression and the role of astrocytic gap junctions

Neuronal activity evokes a localised increase in cerebral blood flow in a response known as neurovascular coupling (NVC), achieved through communication between a group of cells known as a neurovascular unit (NVU). Dysfunctional NVC can lead to pathologies such as cortical spreading depression (CSD), characterised by a slow moving wave of neuronal depolarisation and high extracellular K+ levels. This phenomenon can be affected by the presence of an astrocytic gap junction network which is able to transport K+ away from areas of high concentrations, however the precise role of these gap junctions remains controversial.In this study, a large scale numerical NVC model of a vascular tree coupled with multiple NVUs comprising a two-dimensional cerebral tissue slice is extended through extracellular K+ and Na+ electrodiffusion and K+ transport via an astrocytic gap junction network. An updated NVU model has been utilised that contains complex neuronal and extracellular dynamics and is able to simulate various pathologies such as CSD and the effect on the vascular response.Under pathological conditions (determined by model parameters) and with extracellular electrodiffusion the model is able to simulate a propagating wave of high extracellular K+ travelling at 6.7 mm/min as can occur in CSD. This wave travels outward from the neuronally stimulated area and is followed by a wave of vasoconstriction (with corresponding decreased blood flow) then slight vasodilation in agreement with multiple experimental results. The vasoconstrictive wave peaks after the K+ wave due to the delayed vascular response. Increasing the density of astrocytic gap junctions reduces the duration and amplitude of the vasoconstrictive wave and for high enough density the vasoconstrictive behaviour outside the stimulated area is eliminated. Gap junctions also reduce the area that is initially affected by vasoconstriction. This in silico model provides a complex and experimentally validated test bed for a variety of neurological phenomena.

Using the X‐ray computed tomography method to predict the saturated hydraulic conductivity of the upper root zone in the Loess Plateau in China

Core Ideas Computed tomography (CT)‐measured properties were in the order: soil under Q. liaotungensis &gt; P. tabuliformis &gt; C. korshinskii &gt; M. sativa. The parameters measured by CT could help estimate saturated hydraulic conductivity (Ksat) in the Loess Plateau. Macropore quantity has a higher R2 for predicting Ksat than the morphology of macropores. The recovery of natural vegetation significantly improves soil macroporosity through root decay and biological activity. Macropores are preferential pathways for the movement of water to deep soil. However, the quantification of soil macropore structure and its relationship with soil hydraulic conductivity (Ksat) are not well understood. We characterized the macropores under different vegetation types to evaluate the effects of macropores on Ksat. Undisturbed soil cores were collected from four treatments: areas dominated by Quercus liaotungensis Koidz.(QLI), Pinus tabuliformis Carrière (PTA), Caragana korshinskii Kom. (CKO), and Medicago sativa L.(MSA). A medical computed tomography (CT) scanner was used to acquire images with a voxel size of 0.977 by 0.977 by 1.000 mm for depths of 0 to 360 mm. We used ImageJ software to quantify the macropore properties. Soil structure and Ksat improved with the succession of vegetation. The mean macropore volume fraction across the soil cores for the QLI, PTA, CKO, and MSA treatments were 6.6, 3.5, 1.3, and 0.6% within a 4900‐mm2 area, respectively. Macropore quantity (volume fraction and number) had a higher R2 for predicting Ksat than macropore morphology (branch density, connectivity density, and junction density). Moreover, the grayscale values were negatively correlated with Ksat and accounted for 78.8% of the variation in Ksat. Grayscale values, volume fraction, and the number of macropores were the best combination of CT‐measured parameters for predicting Ksat, accounting for 81.9% of the variation in Ksat. The CT‐measured parameters could be used to estimate Ksat in the upper root zone in the Loess Plateau.

The influence of night warming treatment on the micro-structure of gluten in two wheat cultivars

Bread wheat (Triticum aestivum L.) is one of the important cereals for human life. As people pursue higher quality of life, the requirements of improving the quality of wheat flour also increase accordingly. Global warming exhibits asymmetrically, that is, the warming rate during the night is significantly greater than that during the day. However, the effect of moderate warming on the quality formation of wheat is still unclear. In this study, night warming treatment was carried out at the grain filling stage to clarify the effects of night warming on the accumulation of UPP% (percentage of SDS-unextractable polymeric protein) and micro-structure of wheat gluten, with a strong gluten wheat cultivar Xinong979 and a plain gluten wheat cultivar Tam107 as materials. Results showed that night warming treatment significantly increased the protein content in the grains of the two varieties, accelerated the accumulation rate of UPP%, made the micro-structure of wheat dough more compact and dense and increased the flour processing quality. Quantitative analysis of protein networks showed night warming increased junction density, total protein length and lacunarity of micro-structure of dough in both varieties. Night warming treatment in this study helped the two varieties demonstrate better quality traits in both wheat grain and dough.