Gelation and Orientation Dynamics Induced by Contact of Protein Solution with Transglutaminase Solution.

Gel growth induced by contact of polymer solutions with crosslinker solutions yields an emerging class of anisotropic materials with many potential applications. Here, we report the case of a study on the dynamics in forming anisotropic gels using this approach with an enzyme as a trigger of gelation and gelatin as the polymer. Unlike the previously studied cases of gelation, the isotropic gelation was followed by gel polymer orientation after a lag time. The isotropic gelation dynamics did not depend on concentrations of the polymer turning into gel and of the enzyme inducing gelation, whereas, for the anisotropic gelation, the square of the gel thickness was a linear function of the elapsed time, and the slope increased with polymer concentration. The gelation dynamics of the present system was explained by a combination of diffusion-limited gelation followed by free-energy-limited orientation of polymer molecules.

Relationship between Rate-Limiting Process and Scaling Law in Gel Growth Induced by Liquid-Liquid Contact.

Gelation through the liquid-liquid contact between a polymer solution and a gelator solution has been attempted with various combinations of gelator and polymer solutions. In many combinations, the gel growth dynamics is expressed as X∼t, where X is the gel thickness and t is the elapsed time, and the scaling law holds for the relationship between X and t. In the blood plasma gelation, however, the crossover of the growth behavior from X∼t in the early stage to X∼t in the late stage was observed. It was found that the crossover behavior is caused by a change in the rate-limiting process of growth from the free-energy-limited process to the diffusion-limited process. How, then, would the crossover phenomenon be described in terms of the scaling law? We found that the scaling law does not hold in the early stage owing to the characteristic length attributable to the free energy difference between the sol-gel phases, but it does in the late stage. We also discussed the analysis method for the crossover in terms of the scaling law.

Effects of gentle mechanical skin stimulation on subjective symptoms and joint range of motions in people with chronic neck and shoulder discomfort.

This study aimed to examine the efficacy of a 2-week self-administered gentle mechanical skin stimulation on chronic neck and shoulder discomfort. In participants (n = 12) with chronic neck and shoulder discomfort, subjective measures of pain sensation, discomfort, and difficulty in moving using a visual analog scale (VAS, 0-10) and objective measures of 12 different joint range of motions (ROMs) for the cervical and shoulder regions, using a digital goniometer, were collected before and after self-care with contact acupuncture, called microcones. The self-care for 2 weeks significantly (p < 0.001) decreased all VAS scores to 2.2-2.3 from baseline values of 6.0-7.4. Of the 12 ROMs tested, 8 were significantly increased (p < 0.013). This open-label study suggests the use of self-care with microcones in improving subjective symptoms and joint ROMs in people suffering from chronic neck and shoulder discomfort. However, a randomized, double-blind, controlled clinical trial is needed to further investigate the efficacy and safety of microcones.

Lower limb alignment in healthy Japanese adults.

BACKGROUND: Knowledge regarding the normal alignment of the lower limb is important when considering alignment for total knee arthroplasty. However, few studies have explored the lower limb alignment of healthy Japanese subjects. METHODS: Between July and October 2020, we performed whole leg standing radiography of 120 legs of 60 healthy adult Japanese volunteers aged <50 years in the closed-leg stance. The measurement parameters were hip knee ankle angle (positive for varus), percentage of constitutional varus (hip knee ankle angle ≥ 3°), mechanical axis deviation ratio, mechanical lateral distal femoral angle, medial proximal tibial angle, joint line convergence angle (positive for lateral opening), and tibial joint line angle (positive for medial inclination). RESULTS: The mean measured values for all volunteers, men and women, were as follows: hip knee ankle angle (°), 2.3, 2.6, and 2.0; mechanical axis deviation ratio, 35.8, 35.6, and 36.9; mechanical lateral distal femoral angle (°), 86.7, 87.0, and 86.7; medial proximal tibial angle (°), 85.6, 85.0, and 86.2; joint line convergence angle (°), 0.6, 0.3, and 0.8; and tibial joint line angle (°), -1.0, -0.7, -1.4, respectively. The percentage of constitutional varus was 35.8% overall, 35.8% in men and 35.3% in women. Only the medial proximal tibial angle was smaller in men than that in women (p = 0.003). CONCLUSIONS: The mechanical lateral distal femoral and medial proximal tibial angles were smaller, hip knee ankle angle was larger, and percentage of constitutional varus was higher in Japanese subjects than those reported for subjects in other countries. Our findings improve the understanding of Japanese-specific alignments when considering alignment for lower limb surgery, especially, total knee arthroplasty.

Acute fatty liver of pregnancy at 19 weeks and 0 days of gestation after prolonged hyperemesis gravidarum.

Acute fatty liver of pregnancy (AFLP) is a rare disorder that typically develops in the third trimester. We successfully diagnosed and treated a case of AFLP that developed at 18 weeks' gestation. A 34-year-old woman-gravida 4, para 3-presented with continuous vomiting and abdominal pain and developed convulsive seizures and lost consciousness after transfusion therapy. Cerebral apoplexy was excluded by computed tomography of the brain. Blood tests revealed severe metabolic acidosis, coagulopathy, and leukocytosis, followed by severe hypoglycemia and elevated levels of transaminases and ammonia. The fetus was delivered dead. Whole-body computed tomography showed fatty liver. The patient was diagnosed with AFLP based on the Swansea criteria. AFLP may be a differential diagnosis in the second trimester, and rapid termination should be considered as radical treatment. Starvation may be a risk factor for this disorder.

[Intrathoracic Migration of a Kirschner Wire Successfully Removed by Video-assisted Thoracic Surgery:Report of a Case].

A 40-year-old man who had been surgically treated for the fracture of the right humerus with two Kirschner wires (K-wires) complained of chest pain and difficulty in breathing at fourth day after surgery and visited our hospital. Chest radiography revealed dislocation of the K-wire and right pneumothorax. Video-assisted thoracic surgery( VATS) was performed immediately, and the K-wire was removed safely.

Crossover of Rate-Limiting Process in Plasma Gel Growth by Contact with Source of Gelator.

Plasma is regarded as a solution of precursor polymers specifically transformed to gel-forming polymers by a reaction with initiators. We developed a theory for the gel growth dynamics of plasma induced by contact with a source of gelators that are yielded by the initiation. In developing the theory, we combined the Ginzburg-Landau type dynamics with the gelator diffusion dynamics expressed by the moving boundary picture. The theory predicts the crossover of the rate-limiting process in the time course of the thickness of the gel layer X from the energy-limited process expressed by X∼t to the diffusion-limited process expressed by X∼t, where t is the time elapsed from when the plasma comes into contact with the source of gelators. A demonstration experiment was performed by placing a tissue factor coating plate as the initiator in plasma. Log-log plot of X vs. t showed a crossover as predicted by the theory, and the parameters characterizing plasma were determined.

Gel growth of aqueous konjac glucomannan solution containing sodium trimetaphosphate dialyzed with dilute sodium hydroxide.

The growth rate of the hydrogel of the aqueous konjac glucomannan (KGM) solution containing sodium trimetaphosphate (STMP) dialyzed with aqueous NaOH was investigated in a rectangular cell. The growth rate of the KGM-STMP gel depended on both the KGM and STMP concentrations in addition to the NaOH concentration. The initial growth rate of the KGM-STMP gel was closely related to the diffusion of NaOH into the KGM-STMP solution, leading to the ring-opening reaction of STMP and the deacetylation of KGM at the interface. The time course of the gelation of the KGM-STMP solution was analyzed on the basis of the moving boundary picture theory by introducing the characteristic length to express the consumption of NaOH in the gel layer accompanying the decomposition of STMP. Dynamic mechanical measurements were performed to compare the gelation of the KGM-STMP solution mixed homogeneously with dilute NaOH and the gel dynamics by the dialysis method.

A preliminary study of bowel rest strategy in the management of Clostridioides difficile infection.

Clostridioides difficile infection (CDI) is an important nosocomial infection and is the leading cause of infectious diarrhea in hospitalized patients. We aimed to assess the effect of bowel rest on the management of CDI. A single-center retrospective cohort study was conducted. The primary outcome was the composite of the all-cause mortality and CDI recurrence within 30 days. The main secondary outcome was switching from metronidazole to vancomycin. Of the 91 patients with CDI enrolled as the full cohort, 63 patients (69%) and 28 patients (31%) constituted the control group and the bowel rest group, respectively. After one-to-one propensity score matching, a total of 46 patients were included as the matched cohort. In the full cohort, the composite outcome occurred in 19.0% and 14.3% of the patients in the control and the bowel rest group, respectively (p = 0.768). In the matched cohort, it was 17.4% in each group. Although there was no statistically significant difference, the trend of switching was lower in the bowel rest group. The bowel rest may not affect the all-cause mortality and CDI recurrence within 30 days. However, in those prescribed bowel rest, switching from metronidazole to vancomycin may reduce.

Gel Volume Near the Critical Point of Binary Mixture Isobutyric Acid-Water.

The volume of a cylindrical polyacrylamide gel was measured when immersed in a binary mixture of isobutyric acid-water at different temperatures and weight fractions of isobutyric acid. Near the upper critical solution temperature of the binary mixture, the curve for gel volume vs. isobutyric acid weight fraction has a shoulder or a peak near the critical weight fraction. On the other hand, in a region away from the critical temperature, the gel volume decreased monotonically with increasing isobutyric acid weight fraction. The cloud point temperature of the binary mixture inside the gel was lower than that outside the gel. Thermodynamic description for the gel in the critical mixture is derived on the basis of the Ising model. By the description, the experimental results are explained consistently. The theoretical analysis shows that the shoulder and the peak appearing in the swelling behavior of the gel are respectively induced by the criticalities of the binary mixture outside and inside the gel. It also shows that the cloud point temperature lowering of the binary mixture inside the gel is attributed to the effective enhancement of the temperature of the binary mixture inside the gel induced by the presence of the gel polymer.

Adsorption dynamics of tannin on deacetylated electrospun Konjac glucomannan fabric.

A nonwoven fabric of Konjac glucomannan (KGM) for the adsorption of tannin was fabricated by using electrospinning and then followed by deacetylation with alkaline solution. To analyze the adsorption dynamics of tannin, the time course of the adsorption of tannin on the nonwoven KGM fabric was measured by immersing the fabric in tannin solution at different concentrations of tannin and amounts of the fabric. The initial and late stages of the adsorption behavior could be expressed, respectively, by using a diffusion-limited equation and a stoichiometric equation. A discussion on the dependence of the control parameters on the adsorption behavior is presented. The results represent the first step to provide an effective adsorption procedure for tannin in the use of modified KGM fabric.

Comparison of Stabilizer Effects on the Size, Dispersion, and Catalytic Property of Pt, PtCu, and PtRu Nanoparticles.

Carbon-supported Pt, Pt-Cu, and Pt-Ru nanoparticles were prepared by an alcohol reduction method in the presence of carboxylates and phosphinate in order to investigate the role of these stabilizers in the nanoparticle formation process and the effect on catalytic properties in 2-propanol oxidation. For the Pt-Cu system, long chain carboxylate gave small dispersed particles even with high metal loading while phosphinate gave aggregated particles. For the Pt and Pt-Ru systems, fewer aggregates were observed and the particle size was independent of the chain length of carboxylate while much smaller and dispersed particles were obtained with phosphinate. Phosphinate mainly prevents metal crystal growth while carboxylates prevent both crystal growth and formation of aggregated particles. Although surface poisoning is severe on small dispersed particles in 2-propanol oxidation, dehydrogenation of 2-propanol at low potential is little affected. Phosphinate-protected catalysts were more tolerant to poisoning promoting 2-propanol electrooxidation at high potential range. The presence of Cu promoted 2-propanol electrooxidation at low potential range. These components made phosphinate-protected PtCu best perform in 2-propanol oxidation at 30 °C.

Analysis of Heterogeneous Gelation Dynamics and Their Application to Blood Coagulation.

We present a scaling model based on a moving boundary picture to describe heterogeneous gelation dynamics. The dynamics of gelation induced by different gelation mechanisms is expressed by the scaled equation for the time taken for development of the gel layer with a few kinetic coefficients characterizing the system. The physical meaning obtained by the analysis for a simple boundary condition from the standpoint of the phase transition shows that the time development of the gelation layer depends on whether the dynamics of the order parameter expressing the gelation of the polymer solution is fast or slow compared with the diffusion of the gelators in the heterogeneous gelation. The analytical method is used to understand the coagulation of blood from various animals. An experiment using systems with plasma coagulation occurring at interfaces with calcium chloride solution and with packed erythrocytes is performed to provide the data for model fitting and it is clarified that a few key kinetic coefficients in plasma coagulation can be estimated from the analysis of gelation dynamics.

Comparison of Quantitative Antifungal Testing Methods for Textile Fabrics.

　Quantitative antifungal testing methods for textile fabrics under growth-supportive conditions were studied. Fungal growth activities on unfinished textile fabrics and textile fabrics modified with Ag nanoparticles were investigated using the colony counting method and the luminescence method. Morphological changes of the fungi during incubation were investigated by microscopic observation. Comparison of the results indicated that the fungal growth activity values obtained with the colony counting method depended on the morphological state of the fungi on textile fabrics, whereas those obtained with the luminescence method did not. Our findings indicated that unique characteristics of each testing method must be taken into account for the proper evaluation of antifungal activity.

Brain response patterns to economic inequity predict present and future depression indices.

Widening economic inequity has been suggested to associate with depression. However, little is known about the underlying neural mechanisms of this link. Here, we demonstrate that functional magnetic resonance imaging activity patterns in the amygdala and hippocampus induced by the inequity between the self and other rewards during an economic game can predict participants' present and future (measured one year later) depression indices. Such predictions were not possible using participant's behavioural and socio-economic status measures. These findings suggest that sensitivity to economic inequity has a critical effect on human mood states, and the amygdala and hippocampus play a key role in individual differences in the effect.

Study of plasma coagulation induced by contact with calcium chloride solution.

Blood coagulation capability is one of the most important factors for the diagnosis of patients with thrombosis. Regarding the blood coagulation as an example of gelation of soft matter, we can apply an analytical method to this phenomenon and pick up some relevant parameters. In various systems, gelation dynamics induced by contact between a polymer solution and a crosslinker solution are well explained by the "moving boundary picture" (Yamamoto et al., J. Phys. Chem. B, 2010, 114, 10002-10009). The aim of this paper is to clarify whether this picture can be applied to a clinically important biological system used for blood coagulation tests. We have measured the time course of the thickness of a plasma gel layer formed when plasma comes in contact with calcium chloride solution in a rectangular cell and analyzed theoretically on the basis of the moving boundary picture. The entire process was well expressed using a scaled equation involving three parameters characterizing the plasma, k, Kin, and ß, where k is the time required to reach the incipient stage of three-dimensional network formation, the parameter Kin is proportional to calcium chloride concentration and ß is a constant. These results indicate the direct applicability of the general theory of gelation dynamics induced by contact between two solutions to the in vitro coagulation (gelation) of plasma, and the fitting parameters may be used for diagnosis.

Erythrocyte aggregation under high pressure studied by laser photometry and mathematical analysis.

The effects of hydrostatic pressure on erythrocyte aggregation have been studied by laser photometry and analysis based on a phenomenological theory. Samples were prepared by suspending swine erythrocytes in their own plasma. A high-pressure vessel consisting of a stainless-steel block with a hole to hold a sample cell and two sapphire windows to allows the passage of a He-Ne laser beam was used in the experimental setup. The suspension was stirred at 1500 rpm to disperse the erythrocytes homogeneously. Immediately after reducing the stirring rate from 1500 rpm to 300 rpm, the transmitted light intensity (I) was recorded every 10 ms under a high pressure of 40-200 MPa. The value of I increased with time (t) owing to erythrocyte aggregation. From the phenomenological theory, the equation ΔI(t)=ΔIeq[1-e(-Kt)/(1-B(1-e(-Kt)))] was derived for the change in the transmitted light intensity (ΔI) due to erythrocyte aggregation, where ΔIeq is the transmitted light intensity in the steady state, K is a time constant and B is a constant that represents the ratio of the number of interaction sites on erythrocyte aggregates at time t to that in the steady state. The observed time courses of ΔI obtained at all pressures could be closely fitted to the theoretical equation. ΔIeq roughly increased with increasing pressure. On the other hand, K and B abruptly decreased above 120 MPa. The growth rate of aggregates decreased above 120 MPa. These results suggest a change in the mechanism of erythrocyte aggregation at approximately 120 MPa. We discuss the physical meaning of the parameters.

[Evaluation of the right internal iliac artery which is anastomosed to transplant renal artery using non-contrast enhanced MR angiography with electrocardiography-gated and 3D True SSFP time-spatial labeling inversion pulse sequence].

To evaluate whether electrocardiography-gated is useful in non-contrast-enhanced MRA with time-spatial labeling inversion pulse (Time-SLIP) in renal transplantation patients compared with respiration-triggered free-breathing. Simulation-based analyses of black blood time interval (BBTI) values for spatial selective inversion-recovery pulse and electrocardiography rates were performed, and confirmed on human subjects using a three-dimensional (3D) coherent steady-state free precession (SSFP) sequence on a 1.5 tesla Toshiba MRI scanner. Signal acquisition interval and BBTI values in which signal of a water tissue becomes the null point showed a strong correlation, and successfully suppressed signals from the background and provided better contrast between the arteries and the background. Because electrocardiography-gated non-contrast MRA does not depend on the respiration interval, providing a contrast stable, it was suggested to be an effective screening tool for evaluation of pelvic arteries.

X-ray-induced reduction of Au ions in an aqueous solution in the presence of support materials and in situ time-resolved XANES measurements.

Synchrotron X-ray-induced reduction of Au ions in an aqueous solution with or without support materials is reported. To clarify the process of radiation-induced reduction of metal ions in aqueous solutions in the presence of carbon particles as support materials, in situ time-resolved XANES measurements of Au ions were performed under synchrotron X-ray irradiation. XANES spectra were obtained only when hydrophobic carbon particles were added to the precursor solution containing Au ions. Changes in the shape of the XANES spectra indicated a rapid reduction from ionic to metallic Au in the precursor solution owing to synchrotron X-ray irradiation. In addition, the effects of the wettability of the carbon particles on the deposited Au metallic spots were examined. The deposited Au metallic spots were different depending on the relationship of surface charges between metal precursors and support materials. Moreover, a Au film was obtained as a by-product only when hydrophilic carbon particles were added to the precursor solution containing the Au ions.

Model carcinogen adsorption dynamics of DNA gel.

We have derived theoretical equations describing the adsorption of carcinogen to gels in an immersion medium containing carcinogens. The theory was developed for a cylindrical boundary condition under the assumption of a carcinogen diffusion-limited process combined with the "moving boundary picture (Furusawa et al., 2007)". The time course of the adsorbed carcinogen layer thickness and that of the carcinogen concentration in an immersion medium were expressed by a set of scaled variables, and the asymptotic behavior in the initial stage was derived. Experiments based on the theory were performed using a DNA gel sandwiched between a set of coverglasses in a medium containing acridine orange (AO). The boundary between the AO-adsorbed gel layer and AO-nonadsorbed gel layer was traced during the immersion. The time courses of the AO-adsorbed gel layer thickness and the AO concentration in the immersion medium were well explained by the theory, and the number ratio of the total AO molecules to the adsorption sites in the DNA gel was determined.