The inspection gallery of a dam is leached by reservoir water that has infiltrated through the rock-fill dam body from the high-pressure water area upstream (leakage), and groundwater seeping through ...the foundation bed which has been injected with ordinary Portland cement (OPC) grout. Seepage waters with a pH greater than 12 are characterized by the major components of Ca(OH)2 and alkali hydroxides, lower Mg2+ concentration and higher K+/Na+ molar ratio than those for river and spring waters and groundwater near the dam site, and the extensive carbonate deposits precipitated from the waters. During a low discharge period, NaOH was the major component because Ca2+ was removed as carbonate deposits. Based on the stable isotope ratios of hydrogen and oxygen in the water, which reflect the altitude effect, it was inferred that the seepage waters are supplied from the shallow groundwater near the dam site and that the leakage is a mixture of the seepage water and reservoir water. Alkali hydroxides and Ca(OH)2 cement porewaters formed during the early stages of hydration of OPC are still present in the cement mass after 46 years, and that the OPC still remains partially unhydrated. These highly alkaline porewaters have seeped through gaps of the concrete joint surfaces to discharge into the inspection gallery. The Ca(OH)2 concentration in the seepage was below the portlandite saturation, therefore, the grout-derived solutes are considered to have been diluted as they diffused into the shallow groundwater before being discharged with the groundwater seeping into the gallery due to the hydraulic head difference and mixed with the groundwater. Ca(OH)2 in the seepage reacted with atmospheric CO2 in the inspection gallery, and the carbon stable isotope ratio of the carbonate deposits produced in this way was unusually low, about −25‰ VPDB, due to the large disequilibrium isotope fractionation during the direct reaction of CO2 with OH− in the solution. In addition to the change in its discharge, the hyperalkaline seepage and the resulting carbonate deposits with unusually low δ13C values can be measures of the durability of the grout-treated foundation rock of the rock-fill dam, because the decrease in pH in the future is related to the instability of the grout hydration products by carbonation.
•Seepage waters with a pH greater than 12 have been observed in an inspection gallery of an over 46 years old rock-fill dam.•Hyperalkaline seepage waters are characterized by their high calcium and alkali hydroxides contents and by calcite deposits.•Altitude effect of hydrogen and oxygen isotope ratios of water could allow estimating their source waters.•The unusually low δ13C carbonate deposits were produced by the direct reaction of atmospheric CO2 with OH- in the solution.•The hyperalkaline seepage and the carbonate deposits can be measures of the grout-treated foundation rock durability.
The extracellular matrix (ECM) comprises the heterogeneous environment outside of cells in a biological system. The ECM is dynamically organized and regulated, and many biomolecules secreted from ...cells diffuse throughout the ECM, regulating a variety of cellular processes. Therefore, investigation of the diffusive behaviors of biomolecules in the extracellular environment is critical. In this study, we investigated the diffusion coefficients of biomolecules of various sizes, measuring from 1 to 10 nm in radius, by fluorescence correlation spectroscopy in contracted collagen gel caused by fibroblasts, a traditional culture model of dynamic rearrangement of collagen fibers. The diffusion coefficients of the biomolecules in control collagen gel without cells decreased slightly as compared to those in solution, while the diffusion coefficients of biomolecules in the contracted gel at the cell vicinity decreased dramatically. Additionally, the diffusion coefficients of biomolecules were inversely correlated with molecular radius. In collagen gels populated with fibroblasts, the diffusion coefficient at the cell vicinity clearly decreased in the first 24 h of culture. Furthermore, molecular diffusion was greatly restricted, with a central focus on the populated cells. By using the obtained diffusion coefficients of biomolecules, we calculated the collagen fiber condensation ratio by fibroblasts in the cell vicinity at 3 days of culture to represent a 52-fold concentration. Thus, biomolecular diffusion is restricted in the vicinity of the cells where collagen fibers are highly condensed.
Cell adhesion is mediated by adhesion molecules, but also regulated by adhesion inhibitory molecules. Molecules such as leukocyte sialomucin and phosphorylated-Ezrin/Radixin/Moesin (ERM) inhibit ...cell-substratum adhesion. Here we show that these adhesion inhibitory molecules also inhibit aggregate formation of adherent cells in suspension culture. Expression of sialomucin, CD43 or CD34, inhibited formation of packed aggregates in HEK293T cells. Deletion mutant analysis and enzymatic cleavage indicated the significance of the extracellular sialomucin domain for this inhibition. Meanwhile, phosphorylated-ERM were decreased coincidently with aggregate formation. Combined with the inhibition of aggregate formation by the expression of phospho-mimetic Moesin mutant (Moesin-T558D), phosphorylated-ERM are inhibitors for aggregate formation. Increase of phosphorylated-ERM by CD43 and sialomucin-dependence of Moesin-T558D’s inhibition indicate that sialomucin and phosphorylated-ERM collaborate to inhibit aggregate formation.
Because aggregate formation of HEK293T cells is mediated by N-cadherin, sialomucin and phosphorylated-ERM inhibit cadherin-mediated cell-cell adhesion. Thus, sialomucin and phosphorylated-ERM are inhibitors for both cell-cell adhesion and cell-substratum adhesion, and regulation of these inhibitory molecules is essential for cell adhesion.
•Phosphorylated-ERM are dephosphorylated upon aggregate formation.•Expression of Moesin-T558D mutant inhibits aggregate formation of HEK293T cells.•Expression of CD43 inhibits aggregate formation of HEK293T cells in suspension.•Sialomucin and phosphorylated-ERM collaborate to inhibit aggregate formation.•Dephosphorylation of ERM is essential for cell-cell and cell-substratum adhesion.
In the field of regenerative medicine, tremendous numbers of cells are necessary for tissue/organ regeneration. Today automatic cell-culturing system has been developed. The next step is constructing ...a non-invasive method to monitor the conditions of cells automatically. As an image analysis method, convolutional neural network (CNN), one of the deep learning method, is approaching human recognition level. We constructed and applied the CNN algorithm for automatic cellular differentiation recognition of myogenic C2C12 cell line. Phase-contrast images of cultured C2C12 are prepared as input dataset. In differentiation process from myoblasts to myotubes, cellular morphology changes from round shape to elongated tubular shape due to fusion of the cells. CNN abstract the features of the shape of the cells and classify the cells depending on the culturing days from when differentiation is induced. Changes in cellular shape depending on the number of days of culture (Day 0, Day 3, Day 6) are classified with 91.3% accuracy. Image analysis with CNN has a potential to realize regenerative medicine industry.
Although circulating leukocytes are non-adherent cells, they also undergo adhesion in response to external stimuli. To elucidate this switch mechanism, we investigated PMA-induced cell adhesion in ...myelomonocytic KG-1 cells. PMA induced microvillius collapse, decrease of cell surface rigidity and exclusion of sialomucin from adhesion sites. All these adhesion-contributing events are linked to dephosphorylation of Ezrin/Radixin/Moesin (ERM) proteins. Indeed, PMA-treatment induced quick decrease of phosphorylated ERM proteins, while expression of Moesin-T558D, a phospho-mimetic mutant, inhibited PMA-induced cell adhesion. PMA-induced cell adhesion and ERM-dephophorylation were inhibited by PKC inhibitors or by a phosphatase inhibitor, indicating the involvement of PKC and protein phophatase in these processes. In peripheral T lymphocytes, ERM-dephosphorylation by adhesion-inducing stimuli was inhibited by a PKC inhibitor. Combined, these findings strongly suggest that external stimuli induce ERM-dephosphorylation via the activation of PKC in leukocytes and that ERM-dephosphorylation leads to leukocytes’ adhesion.
•PMA induced cell adhesion, microvilli collapse and decreased rigidity in KG-1 cells.•PMA also induced Ezrin/Radixin/Moesin (ERM)-dephosphorylation in KG-1 cells.•Expression of Moesin phospho-mimetic mutant inhibited PMA-induced KG-1 cell adhesion.•PKC inhibitors inhibited cell adhesion and ERM-dephosphorylation in KG-1 cells.•A PKC inhibitor inhibited stimuli-induced ERM-dephosphorylation in T lymphocytes.
Abstract
This study sought to develop a deep learning-based diagnostic algorithm for plaque vulnerability by analyzing intravascular optical coherence tomography (OCT) images and to investigate the ...relation between AI-plaque vulnerability and clinical outcomes in patients with coronary artery disease (CAD). A total of 1791 study patients who underwent OCT examinations were recruited from a multicenter clinical database, and the OCT images were first labeled as either normal, a stable plaque, or a vulnerable plaque by expert cardiologists. A DenseNet-121-based deep learning algorithm for plaque characterization was developed by training with 44,947 prelabeled OCT images, and demonstrated excellent differentiation among normal, stable plaques, and vulnerable plaques. Patients who were diagnosed with vulnerable plaques by the algorithm had a significantly higher rate of both events from the OCT-observed segments and clinical events than the patients with normal and stable plaque (log-rank p < 0.001). On the multivariate logistic regression analyses, the OCT diagnosis of a vulnerable plaque by the algorithm was independently associated with both types of events (p = 0.047 and p < 0.001, respectively). The AI analysis of intracoronary OCT imaging can assist cardiologists in diagnosing plaque vulnerability and identifying CAD patients with a high probability of occurrence of future clinical events.
Filamentous actin (F-actin) forms many types of structures and dynamically regulates cell morphology and movement, and plays a mechanosensory role for extracellular stimuli. In this study, we ...determined that the smooth muscle-related transcription factor, cysteine-rich protein 2 (CRP2), regulates the supramolecular networks of F-actin. The structures of CRP2 and F-actin in solution were analyzed by small-angle X-ray solution scattering (SAXS). The general shape of CRP2 was partially unfolded and relatively ellipsoidal in structure, and the apparent cross sectional radius of gyration (Rc) was about 15.8 Å. The predicted shape, derived by ab initio modeling, consisted of roughly four tandem clusters: LIM domains were likely at both ends with the middle clusters being an unfolded linker region. From the SAXS analysis, the Rc of F-actin was about 26.7 Å, and it was independent of CRP2 addition. On the other hand, in the low angle region of the CRP2-bound F-actin scattering, the intensities showed upward curvature with the addition of CRP2, which indicates increasing branching of F-actin following CRP2 binding. From biochemical analysis, the actin filaments were augmented and clustered by the addition of CRP2. This F-actin clustering activity of CRP2 was cooperative with α-actinin. Thus, binding of CRP2 to F-actin accelerates actin polymerization and F-actin cluster formation.
Purpose Little attention has been paid to injury mechanisms of foveal avulsion of the triangular fibrocartilage complex (TFCC). The purpose of this study was to determine whether the mechanism of ...injury is associated with different anatomic disruptions as well as different preoperative clinical symptoms. We also evaluated the clinical results of an open repair method for foveal avulsion according to the mechanism of injury. Methods Fifteen patients with a traumatic foveal TFCC avulsion were treated with an open repair technique. The injury mechanism was forced wrist extension in 10 patients (group E) and forced forearm rotation in 5 patients (group R). All patients in group E and 3 in group R showed positive fovea signs. Surgical and clinical findings were compared according to the 2 types of injury mechanism. Results Foveal insertions of TFCC were found in surgery to be disrupted in all 15 patients. In addition, disruption of the dorsal styloid insertions of the radioulnar ligament showed a significantly greater association with group R than with group E. Clinical results showed significant postoperative improvement but were marginally different between the 2 groups. Conclusions The most common mechanism of foveal TFCC avulsions is forced wrist extension, an injury that commonly shows positive fovea signs and leaves the dorsal styloid insertion of the radioulnar ligament intact. Forced forearm rotation is the second most common injury mechanism that is more frequently associated with disruption of the dorsal styloid insertion. Type of study/level of evidence Prognostic IV.
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