Dynamics of drying colloidal suspensions, measured by optical coherence tomography.

Colloidal suspensions are the basis of a wide variety of coatings, prepared as liquids and then dried into solid films. The processes at play during film formation, however, are difficult to observe directly. Here, we demonstrate that optical coherence tomography (OCT) can provide fast, non-contact, precise profiling of the dynamics within a drying suspension. Using a scanning Michelson interferometer with a broadband laser source, OCT creates cross-sectional images of the optical stratigraphy of a sample. With this method, we observed the drying of colloidal silica in Hele-Shaw cells with 10 µm transverse and 1.8 µm depth resolution, over a 1 cm scan line and a 15 s sampling period. The resulting images were calibrated to show how the concentration of colloidal particles varied with position and drying time. This gives access to important transport properties, for example, of how collective diffusion depends on particle concentration. Looking at early-time behaviours, we also show how a drying front initially develops, and how the induction time before the appearance of a solid film depends on the balance of diffusion and evaporation-driven motion. Pairing these results with optical microscopy and particle tracking techniques, we find that film formation can be significantly delayed by any density-driven circulation occurring near the drying front.

Position-dependent rates of film growth in drying colloidal suspensions on tilted air-water interfaces.

Suspended particles in a solvent form a packed film when the solvent evaporates. We investigated film growth rates in a narrow channel on a tilted drying interface and observed clear differences in the rates of film growth. Films grew faster at one end and slower at the other; thus, the slope of the packing front, i.e., the boundary between the packed film and the drying suspension, changed as drying proceeded. However, the difference in film growth rates became smaller as the slope of the packing front changed and the rates of film growth at the either end ultimately became identical. We found that the differences in the rates of film growth were proportional to cosθ, where θ is the angle defined by the slope of the packing front. We constructed a mathematical description to successfully express the time evolution of both the difference in the growth rates and the packing front angle θ. Relationships between drying-induced flow of bulk suspensions and transport of suspended particles to the tilted packing front are discussed.

Buckling and Drying Kinetics of Particle-Stabilized Water Droplets Fully or Partially Immersed in an Oil Layer.

We have investigated the effect of buckling of particle-stabilized water droplets on the drying kinetics. Particle-stabilized water droplets in an oil phase were prepared and the shrinking modes of the droplets during drying were controlled by the wettability of the particles. We obtained water droplets with and without buckling and used them in drying experiments. The drying times were comparable when the droplets were fully immersed in a thick oil layer. However, when the thickness of the oil layer was smaller than the droplet diameter, the buckled droplets showed faster drying. Observation of the reflection images around the droplets suggested that the buckled droplets preferentially shrank in the height direction, while the droplets without buckling isotropically shrank. Mathematical models that assumed diffusion of dissolved water molecules in the oil layer showed good agreement with the experimental data. The effective water-oil interfacial area was constant in the buckled droplets, whereas it shrank in the droplets without buckling. This would be a reason for the faster drying of the partially immersed buckled droplets. Particulate shells on liquid droplets could be used to enhance droplet drying.

Positive Lusitropic Effect of Quercetin on Isolated Ventricular Myocardia from Normal and Streptozotocin-Induced Diabetic Mice.

The lusitropic effect of quercetin was examined on isolated ventricular myocardial tissue preparations from normal and streptozotocin-induced diabetic mice. The time required for 90% relaxation of the myocardium, which was prolonged in the diabetic mice, was shortened by quercetin in both normal and diabetic myocardia. This effect of quercetin was completely inhibited by cyclopiazonic acid but not by SEA0400. These results indicated that quercetin accelerates myocardial relaxation through activation of the sarco-endoplasmic reticulum Ca2+-ATPase.

Emergency aortic valve replacement complicated by unmanaged pheochromocytoma.

A 53-year-old male undergoing emergency aortic valve replacement for infective endocarditis developed a hypertensive crisis early during the operation. Suspecting a pheochromocytoma, intravenous phentolamine was immediately administered, after which the procedure was completed as scheduled. Although quite rare, a pheochromocytoma can be encountered during emergency open heart surgery; thus, early recognition of abnormal blood pressure change and appropriate management are important. Here, we present details of blood pressure control mainly by use of phentolamine, in this case, to demonstrate effective management of a hypertensive crisis during emergency cardiac surgery because of a pheochromocytoma.

Infected aortic aneurysm caused by Helicobacter cinaedi: case series and systematic review of the literature.

BACKGROUND: Helicobacter cinaedi is rarely identified as a cause of infected aneurysms; however, the number of reported cases has been increasing over several decades, especially in Japan. We report three cases of aortic aneurysm infected by H. cinaedi that were successfully treated using meropenem plus surgical stent graft replacement or intravascular stenting. Furthermore, we performed a systematic review of the literature regarding aortic aneurysm infected by H. cinaedi. CASE PRESENTATION: We present three rare cases of infected aneurysm caused by H. cinaedi in adults. Blood and tissue cultures and 16S rRNA gene sequencing were used for diagnosis. Two patients underwent urgent surgical stent graft replacement, and the other patient underwent intravascular stenting. All three cases were treated successfully with intravenous meropenem for 4 to 6 weeks. CONCLUSIONS: These cases suggest that although aneurysms infected by H. cinaedi are rare, clinicians should be aware of H. cinaedi as a potential causative pathogen, even in immunocompetent patients. Prolonged incubation periods for blood cultures are necessary for the accurate detection of H. cinaedi.

Low-loss graded-index polymer crossed optical waveguide with high thermal resistance.

In this paper, crossed polymer waveguides with graded-index (GI) square cores are fabricated using the soft-lithography method. We experimentally demonstrate that the fabricated GI-core crossed waveguides exhibit a much lower insertion loss than conventional step index (SI)-core counterparts, which is almost independent of the cross angle. We also show in this paper that the crossed waveguides fabricated applying organic-inorganic hybrid resins show remarkably high thermal resistance compared to the waveguides fabricated utilizing an acrylate resin and a dopant system we previously reported.

A quantitative study of enhanced drying flux from a narrow liquid-air interface of colloidal suspensions during directional drying.

We evaluate an enhancement of the drying flux from a narrow drying interface. We examine drying of colloidal suspensions in a directional drying cell with various combinations of width and height to change the area of the drying interface. The drying flux changes depending on the height or width of the drying interface. A simple scaling law describes the experimental data quantitatively. Using this effect, we systematically change the drying flux and analyze the formation kinetics of particulate films. There is a threshold drying flux for immediate film formation after the beginning of drying. In addition, the threshold drying flux depends on the initial volume fraction of particles. A kinetics model based on the conservation of particles explains the threshold well.

Activation of Lyn tyrosine kinase through decreased membrane cholesterol levels during a change in its membrane distribution upon cell detachment.

Cellular membranes, which can serve as scaffolds for signal transduction, dynamically change their characteristics upon cell detachment. Src family kinases undergo post-translational lipid modification and are involved in a wide range of signaling events at the plasma membrane, such as cell proliferation, cell adhesion, and survival. Previously, we showed the differential membrane distributions among the members of Src family kinases by sucrose density gradient fractionation. However, little is known about the regulation of the membrane distribution of Src family kinases upon cell detachment. Here, we show that cell detachment shifts the main peak of the membrane distribution of Lyn, a member of Src family kinase, from the low density to the high density membrane fractions and enhances the kinase activity of Lyn. The change in Lyn distribution upon cell detachment involves both dynamin activity and a decrease in membrane cholesterol. Cell detachment activates Lyn through decreased membrane cholesterol levels during a change in its membrane distribution. Furthermore, cholesterol incorporation decreases Lyn activity and reduces the viability of suspension cells. These results suggest that cell detachment-induced Lyn activation through the change in the membrane distribution of Lyn plays an important role in survival of suspension cells.

Nuclear ErbB4 signaling through H3K9me3 is antagonized by EGFR-activated c-Src.

The ErbB family of receptor tyrosine kinases comprises four members: epidermal growth factor receptor (EGFR)/ErbB1, HER2/ErbB2, ErbB3 and ErbB4, and plays roles in signal transduction at the plasma membrane upon ligand stimulation. Stimulation with neuregulin-1 (NRG-1) cleaves ErbB4 and releases the ErbB4 intracellular domain (4ICD) that translocates into the nucleus to control gene expression. However, little is known about the regulation of 4ICD nuclear signaling through tyrosine phosphorylation. We show here that 4ICD nuclear signaling is antagonized by EGF-induced c-Src activation through EGFR. Generation of 4ICD by NRG-1 leads to increased levels of trimethylated histone H3 on lysine 9 (H3K9me3) in a manner dependent on the nuclear accumulation of 4ICD and its tyrosine kinase activity. Once EGF activates c-Src downstream of EGFR concomitantly with NRG-1-induced ErbB4 activation, c-Src associates with phospho-Tyr950 and phospho-Tyr1056 on 4ICD, thereby decreasing nuclear accumulation of 4ICD and inhibiting an increase of H3K9me3 levels. Moreover, 4ICD-induced transcriptional repression of the human telomerase reverse transcriptase (hTERT) is inhibited by EGF-EGFR-Src signaling. Thus, our findings reveal c-Src-mediated inhibitory regulation of ErbB4 nuclear signaling upon EGFR activation.

c-Abl induces stabilization of histone deacetylase 1 (HDAC1) in a kinase activity-dependent manner.

c-Abl is a non-receptor-type tyrosine kinase that regulates various cellular events, including cell proliferation, differentiation, and apoptosis, through phosphorylation of cytoplasmic and nuclear targets. Although we showed that c-Abl induces histone deacetylation, the molecular mechanisms of this phenomenon are largely unknown. Here, we analyzed the effect of c-Abl on the expression of histone deacetylase 1 (HDAC1), because c-Abl was shown to be involved in maintenance of nuclear protein levels of HDAC1. Co-transfection of HDAC1 with c-Abl increased the levels of HDAC1 protein in a kinase activity-dependent manner without affecting its mRNA levels. Treatment with the proteasome inhibitor MG132 increased protein levels of HDAC1 in cells transfected with HDAC1 but not in cells co-transfected with HDAC1 and c-Abl. Among class I HDACs, knockdown of endogenous c-Abl preferentially suppressed endogenous protein levels of HDAC1, suggesting that c-Abl stabilizes HDAC1 protein by inhibiting its proteasomal degradation. Subcellular fractionation showed that the stabilization of HDAC1 by c-Abl occurred in the nucleus. Despite the fact that HDAC1 was phosphorylated by co-expression with c-Abl, stabilization of HDAC1 by c-Abl was not affected by mutations in its sites phosphorylated by c-Abl. Co-expression with HDAC1 and nuclear-targeted c-Abl did not affect HDAC1 stabilization. Therefore, these results suggest that c-Abl induces HDAC1 stabilization possibly through phosphorylation of a cytoplasmic target that is involved in proteasomal degradation of HDAC1.

Endograft infection after hybrid surgery for chronic Stanford type B aortic dissection: endograft infection and treatment.

While the incidence of endograft infection is very low, the treatment is difficult when it occurs. We herein present the case of a 52-year-old male who had undergone a graft replacement in the proximal descending thoracic aorta for dissected aortic aneurysm (DA) 6 years previously and hybrid surgery 2 years previously, which consisted of an abdominal graft replacement, visceral and renal debranching surgery and endovascular surgery for a ruptured abdominal DA and residual thoracoabdominal DA. Following collapse from septic shock due to an endograft infection, we performed an in situ reconstruction of the entire thoracoabdominal aorta following intensive antibiotic therapy and 2 preoperative CT-guided percutaneous interventions. He was discharged 4 weeks after the surgery without any complications.

v-Src causes delocalization of Mklp1, Aurora B, and INCENP from the spindle midzone during cytokinesis failure.

Src-family tyrosine kinases are aberrantly activated in cancers, and this activation is associated with malignant tumor progression. v-Src, encoded by the v-src transforming gene of the Rous sarcoma virus, is a mutant variant of the cellular proto-oncogene c-Src. Although investigations with temperature sensitive mutants of v-Src have shown that v-Src induces many oncogenic processes, the effects on cell division are unknown. Here, we show that v-Src inhibits cellular proliferation of HCT116, HeLa S3 and NIH3T3 cells. Flow cytometry analysis indicated that inducible expression of v-Src results in an accumulation of 4N cells. Time-lapse analysis revealed that binucleation is induced through the inhibition of cytokinesis, a final step of cell division. The localization of Mklp1, which is essential for cytokinesis, to the spindle midzone is inhibited in v-Src-expressing cells. Intriguingly, Aurora B, which regulates Mklp1 localization at the midzone, is delocalized from the spindle midzone and the midbody but not from the metaphase chromosomes upon v-Src expression. Mklp2, which is responsible for the relocation of Aurora B from the metaphase chromosomes to the spindle midzone, is also lost from the spindle midzone. These results suggest that v-Src inhibits cytokinesis through the delocalization of Mklp1 and Aurora B from the spindle midzone, resulting in binucleation.

Commissure avulsion of the aortic valve caused by purulent pericarditis: report of a case.

A 20-year-old man with fever and chest pain was referred to our hospital, where purulent pericarditis was confirmed by various examinations. Hemodynamic collapse and acute pulmonary edema occurred 1 week later, caused by acute severe aortic valvular regurgitation (AR). Emergency surgery revealed that the AR had been caused by avulsion of the aortic valvular commissure, which seemed to have resulted from penetration of the pericardial inflammatory process to the aortic root. We report this case because purulent pericarditis is now relatively uncommon and resultant aortic commissure avulsion is even rarer.

Inconsistent False Lumen Enhancement Predicts Late Aortic Events After Hemiarch Replacement in Acute Type A Aortic Dissection.

The impact of inconsistent enhancement within the patent false lumen on the occurrence of late aortic events remains uncertain. We enrolled 55patients who exhibited a patent false lumen after hemiarch replacement. The Hounsfield unit (HU) measurements in the patent false lumen were obtained at 2 specific locations: the aortic arch (a) and the descending aorta (b). The false lumen HU score was calculated as the absolute value of 1 - a/b, representing the discrepancy in HUs within the patent false lumen. We investigated the cut-off value of the false lumen HU score with the receiver operating characteristics curve to predict the incidence of late aortic events. We divided the patients based on the cut-off value and compared the cumulative incidence of the late aortic events. The analysis of the receiver operating characteristics curve showed that the cut-off value of the false lumen HU score was 0.345. Based on this cut-off value, we divided them into 2 groups: Group A (score <0.345, n = 26) and Group B (score ≥0.345, n = 29). The baseline characteristics were similar between the 2 groups. The cumulative incidence of the late aortic events was significantly lower in Group A (7.8% at 5 years) than in Group B (39.9% at 5 years) (p = 0.02). The false lumen HU score might be useful to predict the incidence of late aortic events after hemiarch replacement.

Mitral complex geometric changes aggravate mitral stenosis after transcatheter aortic valve replacement.

Severe aortic valve stenosis (AS) often coexists with mitral valve stenosis (MS). MS aggravation after transcatheter aortic valve replacement (TAVR) is common, and its etiology is multifactorial. We hypothesized that geometric changes in the mitral complex (mitral valvular and annular deformities) are adjunctive factors aggravating MS after TAVR, particularly in older adults with a smaller left ventricle (LV). This study aimed to evaluate the mitral complex geometric changes before and after TAVR and to assess the important predictors of MS aggravation after TAVR. This retrospective study enrolled consecutive adult patients who underwent TAVR and surgical AVR (SAVR) for severe AS. The mitral valve area (MVA), the angle between the anterior mitral valve leaflet (AMVL) and left ventricular outflow tract (LVOT), AMVL length, mitral annular diameter, presence of mitral annular calcification, and LV size were evaluated using transthoracic echocardiography. This study included 258 patients who underwent TAVR and SAVR. MVA index decreased from 2.3 ± 0.6 cm² to 1.9 ± 0.5 cm² in the TAVR group. The angle between the AMVL and LVOT was 56.3 ± 9.7° preoperatively and increased to 67.3 ± 11.5° after TAVR. In multivariate analysis, the most important predictive factors of MS aggravation after TAVR were a smaller mitral annular diameter, restricted AMVL mobility, and implantation depth (odds ratio: 4.5, 5.3,3.0; 95% confidence interval: 1.6-14, 1.9-17, 1.0-8.9; and p = 0.005, p = 0.001, p = 0.042, respectively). The reduction in MVA after TAVR was related to the restriction of AMVL opening, depth of implantation and narrowing of the mitral annulus.

A Novel Method of Real-Time Assessment for Coronary Artery Anastomosis Skill.

PURPOSE: Coronary anastomosis is the most key factor to accomplish coronary artery bypass grafting, which is one of the largest areas in cardiovascular surgery. Although we have organized on-site simulator training courses of coronary anastomosis using BEAT YOUCAN, it became difficult to continue it because of COVID-19. Therefore, we established a real-time evaluation sheet instead of an Objective Structured Assessment of Technical Skills (OSATS) evaluation sheet. The purposes of this study was to develop the real-time assessment system and to prove the correlation between the score obtained by the OSATS and the score obtained by the real-time evaluation system. SUBJECTS AND METHODS: A total of 22 videos from the qualifying round of real-time coronary anastomosis competition evaluated by both the modified OSATS and the real-time evaluation system were utilized in this study. The global rating score of OSATS was compared with the global rating score of real-time evaluation system. RESULTS: When examined the relationship between the OSATS total score and the real-time total score, there was a significant correlation (R = 0.752, p <0.001). The OSATS general definition score and the real-time total score also showed a strong correlation (R = 0.733, p <0.001). CONCLUSIONS: We developed a real-time assessment sheet to evaluate coronary anastomosis. This assessment sheet had a good correlation with the OSATS evaluation sheet.

Quantitative flow ratio versus fractional flow reserve for Heart Team decision-making in multivessel disease: the randomised, multicentre DECISION QFR trial.

BACKGROUND: Vessel-level physiological data derived from pressure wire measurements are one of the important determinant factors in the optimal revascularisation strategy for patients with multivessel disease (MVD). However, these may result in complications and a prolonged procedure time. AIMS: The feasibility of using the quantitative flow ratio (QFR), an angiography-derived fractional flow reserve (FFR), in Heart Team discussions to determine the optimal revascularisation strategy for patients with MVD was investigated. METHODS: Two Heart Teams were randomly assigned either QFR- or FFR-based data of the included patients. They then discussed the optimal revascularisation mode (percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG]) for each patient and made treatment recommendations. The primary endpoint of the trial was the level of agreement between the treatment recommendations of both teams as assessed using Cohen's kappa. RESULTS: The trial included 248 patients with MVD from 10 study sites. Cohen's kappa in the recommended revascularisation modes between the QFR and FFR approaches was 0.73 [95% confidence interval {CI} : 0.62-0.83]. As for the revascularisation planning, agreements in the target vessels for PCI and CABG were substantial for both revascularisation modes (Cohen's kappa=0.72 [95% CI: 0.66-0.78] and 0.72 [95% CI: 0.66-0.78], respectively). The team assigned to the QFR approach provided consistent recommended revascularisation modes even after being made aware of the FFR data (Cohen's kappa=0.95 [95% CI:0.90-1.00]). CONCLUSIONS: QFR provided feasible physiological data in Heart Team discussions to determine the optimal revascularisation strategy for MVD. The QFR and FFR approaches agreed substantially in terms of treatment recommendations.

c-Src but not Fyn promotes proper spindle orientation in early prometaphase.

Src family tyrosine kinases (SFKs) participate in mitotic signal transduction events, including mitotic entry, cleavage furrow ingression, and cytokinesis abscission. Although SFKs have been shown to associate with the mitotic spindle, the role of SFKs in mitotic spindle formation remains unclear. Here, we show that c-Src promotes proper spindle orientation in early prometaphase. Src localizes close to spindle poles in a manner independent of Src kinase activity. Three-dimensional analyses showed that Src inhibition induced spindle misorientation, exhibiting a tilting spindle in early prometaphase. Spindle misorientation is frequently seen in SYF cells, which harbor triple knock-out mutations of c-Src, c-Yes, and Fyn, and reintroduction of c-Src but not Fyn into SYF cells rescued spindle misorientation. Spindle misorientation was also observed upon Src inhibition under conditions in which Aurora B was inhibited. Inducible expression of c-Src promoted a properly oriented bipolar spindle, which was suppressed by Src inhibition. Aster formation was severely inhibited in SYF cells upon Aurora B inhibition, which was rescued by reintroduction of c-Src into SYF cells. Furthermore, reintroduction of c-Src facilitated microtubule regrowth from cold-induced depolymerization and accelerated M phase progression. These results suggest that c-Src is involved in spindle orientation through centrosome-mediated aster formation.

A Novel Technique of No-Touch Endoscopic Saphenous Vein Harvesting.

No-touch saphenous vein harvesting is considered an ideal procedure for harvesting good-quality veins, whereas endoscopic vein harvesting (EVH) is considered ideal for decreasing wound complications. The no-touch EVH (NT-EVH) technique, which was developed in 2018, is one of the best vein-harvesting procedures. We have improved this method in several aspects since our initial experience. Herein, we present the details of this technique.