Measurement of a Bubble-Free Chemical Oscillator Using QCMs Treated with Self-Assembled Monolayers.

The oscillation of a 1,4-cyclohexanedione-bromate (CHD-bromate) system was investigated by using a quartz crystal microbalance (QCM) without or with a self-assembled monolayer (SAM), where gold and platinum were used for QCM electrodes and SAMs were composed of HS(CH2)11CH3, HS(CH2CH2O)5H, and HS(CH2CH2O)5CH3. The CHD-bromate system is well-known as a bubble-free oscillator and oscillates without or with a catalyst. In the CHD-bromate system without a catalyst, the oscillation of a resonant frequency shift (ΔF) of the QCM was observed in the Au-electrode QCMs without a SAM or with SAMs formed from HS(CH2)11CH3 and HS(CH2CH2O)5H. On the other hand, the HS(CH2CH2O)5CH3 SAM suppressed the ΔF oscillation. The results revealed that in the CHD-bromate system without a catalyst, hydrophobic CH3 terminal and helical conformation were important to prevent nonspecific adsorption of substances on a gold surface and its dissolution. In the CHD-bromate system with a catalyst (ferroin), the ΔF oscillation was observed in the Au-electrode QCM with the HS(CH2CH2O)5CH3 SAM. The results suggest evidence that the change of the solution viscosity and density led to the ΔF oscillation. These results for Au-electrode QCMs were also corroborated by those for Pt-electrode QCMs.

Control of Polar/Antipolar Layered Organic Semiconductors by the Odd-Even Effect of Alkyl Chain.

Some rodlike organic molecules exhibit exceptionally high layered crystallinity when composed of a link between π-conjugated backbone (head) and alkyl chain (tail). These molecules are aligned side-by-side unidirectionally to form self-organized polar monomolecular layers, providing promising 2D materials and devices. However, their interlayer stacking arrangements have never been tunable, preventing the unidirectional arrangements of molecules in whole crystals. Here, it is demonstrated that polar/antipolar interlayer stacking can be systematically controlled by the alkyl carbon number n, when the molecules are designed to involve effectively weakened head-to-head affinity. They exhibit remarkable odd-even effect in the interlayer stacking: alternating head-to-head and tail-to-tail (antipolar) arrangement in odd-n crystals, and uniform head-to-tail (polar) arrangement in even-n crystals. The films show excellent field-effect transistor characteristics presenting unique polar/antipolar dependence and considerably improved subthreshold swing in the polar films. Additionally, the polar films present enhanced second-order nonlinear optical response along normal to the film plane. These findings are key for creating polarity-controlled optoelectronic materials and devices.

Temperature Dependence of the Rheology of Soft Matter on a MHz-oscillating Solid-liquid Interface.

The temperature dependence of the resonant length, molecular weight, and rheology (shear viscosity and shear modulus) of chemisorbed soft matter on a solid-liquid interface oscillating at a megahertz frequency was studied using a quartz crystal microbalance. As a form of chemisorbed soft matter, self-assembled monolayers (SAMs) formed from six types of mercapto oligo(ethylene oxide) methyl ethers were used. A systematic analysis using the Voigt model showed that the variation in effective hydrated thickness (sensed mass), which is related to the resonant length, was classified into three types based on the molecular weight. As a result, a 2.2-nm change in the resonant length occurred in the studied temperature range from 10 to 35℃. Moreover, the variation in the effective hydrated thickness was dependent on the shear viscosity and shear modulus of the SAMs. A further investigation revealed that the relationships η 1∝M n 0.13 and µ 1∝M n 0.30 could be estimated regardless of the temperature, where η 1 and µ 1 are the shear viscosity and shear modulus of the SAM, and M n is the molecular weight of mercapto oligo(ethylene oxide) methyl ether. As a result, we revealed that the experimental results followed the polymer formula irrespective of temperature.

Cardiac surgery for patients with schizophrenia: clinical experience of six patients.

PURPOSE: The incidence of schizophrenia in Japan is 0.7%, which is similar to the worldwide incidence. The mortality rate of patients with schizophrenia is reported to be higher than that of the general population, and cardiovascular disease is high among the causes of death. Hence, strategies for cardiovascular surgery for patients with schizophrenia are necessary. METHODS: We studied six patients with schizophrenia (five males, one female) who underwent cardiac surgery in our hospital between April 2008 and December 2019. RESULT: The mean age was 63.6 years. The surgical procedures were coronary artery bypass grafting (CABG) (n = 4), CABG concomitant with valve procedures (n = 1), and resection of myxoma (n = 1). There were no major cardiovascular complications and no other fatal complications. The mean observation period was 1510.6 ± 1430.1 (140-4068) days, the mean post-operative hospital stay was 17.8 ± 3.5 (13-22) days, and there was no mortality within 30 days after surgery. During the observation period, one patient died. The survival rate was 83.3% at 1, 3, and 5 years. CONCLUSION: Cardiac surgery for patients with schizophrenia is possible with careful monitoring of indications and perioperative management.

Fabrication of Biosensing Interface with Monolayers.

Surface modification is recognized as one of the fundamental techniques to fabricate biosensing interfaces. This review focuses on the surface modification of carbon substrates (GC and HOPG) and silica with a close-packed monolayer, in particular. In the cases of carbon substrates, GC and HOPG, it was demonstrated that surface modification of carbon substrates with diazonium derivatives could create a close-packed monolayer similar to the self-assembled monolayer (SAM) formation with mercapto derivatives. Similarly, the potential of trialkoxysilanes to form a close-packed monolayer was evaluated, and modification with a close-packed monolayer tended to occur under milder conditions when the trialkoxysilanes had a longer alkyl chain. In these studies, we synthesized surface modification materials having ferrocene as a redox active moiety to explore features of the modified surfaces by an electrochemical method using cyclic voltammetry, where surface concentrations of immobilized molecules and blocking effect were studied to obtain insight for density leading to a close-packed layer. Based on those findings, fabrication of a biosensing interface on the silica sensing chip of the waveguide-mode sensor was carried out using triethoxysilane derivatives bearing succinimide ester and oligoethylene glycol moieties to immobilize antibodies and to suppress nonspecific adsorption of proteins, respectively. The results demonstrate that the waveguide-mode sensor powered by the biosensing interface fabricated with those triethoxysilane derivatives and antibody has the potential to detect several tens ng/mL of biomarkers in human serum with unlabeled detection method.

A case of persistent sciatic artery aneurysm with recurrent embolism.

INTRODUCTION: Persistent sciatic artery (PSA) is a rare congenital vascular anomaly. It has several clinical features with the formation of aneurysms. Among the complications, leg ischemia is severe problem and the management involves revascularization and prevention of recurrence. We herein describe an anatomically annoying case of PSA aneurysm with recurrent embolism that necessitated thrombectomy and bypass surgery. And this work has been reported in line with the SCARE criteria. CASE PRESENTATION: A 76-year-old woman developed leg embolism twice from PSA aneurysm. PSA was complete type and the popliteal artery ran on the lateral side, which was difficult to approach from the standard medial side. Based on these anatomical conditions, thrombectomy of the posterior-tibial artery (PTA) and femoral-PTA bypass were performed. Additionally, the proximal side of PTA from the anastomosis site was ligated to avoid the recurrence of embolism. Residual PSA aneurysm has not yet been treated, but neither clinical complications nor dilatation have occurred. DISCUSSION: PSA is a rare disease, but should be remember in acute limb ischemia. Clear treatments have not yet been established; therefore, its plans need to be considered based on clinical symptoms and anatomical conditions. CONCLUSION: Although there were anatomical issues in the present case, thrombectomy and bypass surgery were successful and no complications have occurred one year after surgery.

Application of a Waveguide-Mode Sensor to Blood Testing for Hepatitis B Virus, Hepatitis C Virus, Human Immunodeficiency Virus and Treponema pallidum Infection.

Testing for blood-transmitted infectious agents is an important aspect of safe medical treatment. During emergencies, such as significant earthquakes, many patients need surgical treatment and/or blood transfusion. Because a waveguide mode (WM) sensor can be used as a portable, on-site blood testing device in emergency settings, we have previously developed WM sensors for detection of antibodies against hepatitis B virus and hepatitis C virus and for forward ABO and Rh(D) and reverse ABO blood typing. In this study, we compared signal enhancement methods using secondary antibodies conjugated with peroxidase, a fluorescent dye, and gold nanoparticles, and found that the peroxidase reaction method offers superior sensitivity while gold nanoparticles provide the most rapid detection of anti-HBs antibody. Next, we examined whether we could apply a WM sensor with signal enhancement with peroxidase or gold nanoparticles to detection of antibodies against hepatitis C virus, human immunodeficiency virus and Treponema pallidum, and HBs antigen in plasma. We showed that a WM sensor can detect significant signals of these infectious agents within 30 min. Therefore, a portable device utilizing a WM sensor can be used for on-site blood testing of infectious agents in emergency settings.

Sensitive typing of reverse ABO blood groups with a waveguide-mode sensor.

Portable, on-site blood typing methods will help provide life-saving blood transfusions to patients during an emergency or natural calamity, such as significant earthquakes. We have previously developed waveguide-mode (WM) sensors for forward ABO and Rh(D) blood typing and detection of antibodies against hepatitis B virus and hepatitis C virus. In this study, we evaluated a WM-sensor for reverse ABO blood typing. Since reverse ABO blood typing is a method for detection of antibodies against type A and type B oligosaccharide antigens on the surface of red blood cells (RBCs), we fixed a synthetic type A or type B trisaccharide antigen on the sensor chip of the WM sensor. We obtained significant changes in the reflectance spectra from a WM sensor on type A antigen with type B plasma and type O plasma and on type B antigen with type A plasma and type O plasma, and no spectrum changes on type A antigen or type B antigen with type AB plasma. Signal enhancement with the addition of a peroxidase reaction failed to increase the sensitivity for detection on oligosaccharide chips. By utilizing hemagglutination detection using regent type A and type B RBCs, we successfully determined reverse ABO blood groups with higher sensitivity compared to a method using oligosaccharide antigens. Thus, functionality of a portable device utilizing a WM sensor can be expanded to include reverse ABO blood typing and, in combination with forward ABO typing and antivirus antibody detection, may be useful for on-site blood testing in emergency settings.

Surface Modification of PDMS and Plastics with Zwitterionic Polymers.

Surface modification of PDMS, polycarbonate, and acrylic resin was examined using various methacryl polymers bearing sulfobetaine, phosphoryl choline, and oligoethylene glycol units. We have found that zwitterionic polymers are adsorbed on the PDMS surface treated with plasma. The surface of PDMS is stable to keep high hydrophilicity after a month of the modification. On the other hand, one of sulfobetaine polymers showed distinguished adsorption behavior in the case of polycarbonate surface treated with plasma. Suppression effect for nonspecific adsorption of BSA was evaluated using polycarbonate and acrylic resin modified with the polymers. The modified surfaces showed suppression effect for nonspecific adsorption of BSA compared with the surface only treated with plasma.

Properties of modified surface for biosensing interface.

Properties of modified surface, behavior against salting-out effect, suppressive effect for protein nonspecific adsorption, and wettability were examined using various mercapto compounds bearing methyloligoethylene glycol, oligoethylene glycol, alkyl oligoethylene glycol, alkyl phosphoryl choline, alkyl inverse phosphoryl choline, and alkyl sulfobetaine moieties. The behavior against salting-out effect was examined using gold nanoparticle with PBS and NaCl aqueous solution. The suppressive effect for protein nonspecific adsorption was evaluated by SPR, and the wettability was measured on the SPR chip. The gold nanoparticle modified with 8C3EG, 12C4EG, 12CPC, 6CCP, and 12CCP showed excellent behavior against salting-out effect. The suppression of protein nonspecific adsorption was effective with 6EG, 12C4EG, 12CPC, and 12CS. On the other hand, the modified surface possessed high wettability except for the surface modified with M6EG. The results indicate that incorporation of alkyl group into surface modification materials is effective for the enhancement of behavior against salting-out effect and suppressive effect for protein nonspecific adsorption regardless of wettability. Among the zwitter ionic derivatives, inverse phosphoryl choline derivatives showed intriguing properties, high behavior against salting-out effect with high wettability but low suppressive effect for protein nonspecific adsorption.

Detection of antibodies against hepatitis B virus surface antigen and hepatitis C virus core antigen in plasma with a waveguide-mode sensor.

In large-scale disasters, such as huge significant earthquakes, on-site examination for blood typing and infectious disease screening will be very helpful to save lives of victims who need surgical treatment and/or blood transfusion. However, physical damage, such as building collapse, electric power failure and traffic blockage, disrupts the capacity of the medical system. Portable diagnostic devices are useful in such cases of emergency. In this study, we evaluated a waveguide-mode sensor for detection of anti-hepatitis virus antibodies. First, we examined whether we can detect antigen-antibody interaction on a sensor chip immobilized hepatitis B virus surface (HBs) antigen and hepatitis C virus (HCV) core antigen using monoclonal mouse antibodies for HBs antigen and HCV core antigen. We obtained significant changes in the reflectance spectra, which indicate specific antigen-antibody interaction for anti-HBs antibody and anti-HCV antibody. Next, we examined the effect of horseradish peroxidase-conjugated secondary antibody using aminoethyl carbazole as the peroxidase substrate and found that the colorimetric reaction increases detection sensitivity for anti-HBs antibody more than 300 times. Finally, we successfully detected anti-HBs antibody in human blood samples with an enhancing method using a peroxidase reaction. Thus, a portable device utilizing a waveguide-mode sensor may be applied to on-site blood testing in emergency settings.

A case of acute myocardial infarction due to cardiovascular syphilis with aortic regurgitation and bilateral coronary ostial stenosis.

We report an interesting case of a 66-year-old man with acute myocardial infarction (AMI) with bilateral coronary ostial stenosis cardiovascular syphilis complicated by aortic regurgitation (AR). A 12-lead electrocardiogram and blood tests on arrival suggested AMI, and echocardiography showed moderate AR. Emergency coronary angiography showed bilateral coronary ostial stenosis. The patient underwent emergency surgical treatment, coronary artery bypass grafting, and aortic valve replacement with a bioprosthetic valve. On arrival, rapid plasma reagin and Treponema pallidum hemagglutination tests were 172.2- and 1187.5-fold, respectively. These results suggested cardiovascular syphilis, which was confirmed by pathological findings. The postoperative course was uneventful and the patient was transferred to another hospital on postoperative day 25. This patient received intravenous penicillin for 2 weeks and subsequently oral amoxicillin. When both AR and coronary ostial stenosis are found, it is necessary to consider the presence of cardiovascular syphilis.

Convenient stereocontrolled amidoglycosylation of alcohols with acetylated glycals and trichloroethoxysulfonamide.

A regio- and stereo-controlled, rhodium(II)-catalyzed amidoglycosylation of alcohols has been developed using O-acetylated glycals, trichloroethoxysulfonamide, and iodosobenzene. This one-pot amidoglycosylation was applied to a variety of primary and secondary alcohols to afford the ß-O-glycosides with acceptable yields up to 84%. The reaction would proceed via stereoselective intermolecular aziridination of the glycal from the α-face followed by SN2 reaction with alcohol at C-1 from the ß-face to give 1,2:2,3-di-trans-substituted isomer only.

A fluorescent cholesterol analogue for observation of free cholesterol in the plasma membrane of live cells.

Free cholesterol in mammalian cells resides mostly in the plasma membrane, where it plays an important role in cellular homeostasis. We synthesized a new fluorescent cholesterol analogue that retained an intact alkyl chain and the sterane backbone of cholesterol. The hydroxyl group of cholesterol was converted into an amino group that was covalently linked to the fluorophore tetramethylrhodamine to retain the ability to form hydrogen bonds with adjacent molecules. Incubating live MDCK (Madin-Darby canine kidney) cells with our fluorescent cholesterol analogue resulted in the generation of intense signals that were detected by microscopy at the plasma membrane. Incubation with the analogue exerted minimal, if any, influence on cell growth, indicating that it could serve as a useful tool for analyzing free cholesterol at the plasma membrane.

[Second use of preserved aortic cusps for bentall procedure after aortic valve replacement with intravalvular implantation technique in aortitis syndrome].

A 44-year-old woman who had undergone aortic valve replacement with intravalvular implantation technique due to aortitis syndrome 13 years before, required Bentall procedure and hemiarch replacement because of the tissue valve dysfunction and the root and ascending aortic aneurysms. The exposed native aortic cusps sandwiched between the felt pledgets and the tissue valve seemed to be useful in reinforcing the proximal anastomosis of the composite graft. A combination of an intravalvular implantation technique and a skirted composite graft technique was applied, and her postoperative course has been uneventful for more than 2 and a half years.

A single-molecule force-spectroscopic study on stabilization of G-quadruplex DNA by a telomerase inhibitor.

Single-molecule force spectroscopy was carried out using AFM force measurements for the purpose of direct observation of the stabilization of G-quadruplex DNA by a telomerase inhibitor, which is 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin tetrakis(p-toluenesulfonate) (TMPyP). In AFM force measurements, we used an AFM tip and an Au substrate modified chemically with terminal-biotinylated telomere DNA and streptavidin, respectively. The telomere DNA was fully stretched by the AFM tip based on the bridge formation between the AFM tip and the Au substrate through the streptavidin-biotin interaction. The force-extension curves, which reflected the stretching of a single DNA molecule, were distinguished from all of the curves, judging from the rupture force and the contour length. The selected curves were analyzed using a worm-like chain model, and one of the fitting parameters, persistence length (lp), was used as an index for the stabilization of the G-quadruplex structure. Consequently, the lp value was significantly increased by the addition of TMPyP under the experimental conditions where the G-quadruplex structure could be formed. On the other hand, the value was hardly changed by the addition of TMPyP under the conditions except the above. Furthermore, the methodology developed and demonstrated in this work was applied to evaluate the stabilization of G-quadruplex DNA by other telomerase inhibitors such as ethidium bromide and p-xylene-bis(N-pyridinium bromide).

Behavior of polyethylene glycol molecules at an oscillating solid-liquid interface.

The behavior of polyethylene glycol (PEG) molecules at an oscillating solid-liquid interface was examined using a quartz crystal microbalance (QCM). The number-average molecular weights (Mn) of PEG molecules were systematically varied. This study revealed that the shift in the energy dissipation factor, ΔD, of the QCM against square root of the density-viscosity product of the PEG solution is linear and has an intercept. Moreover, the systematical analysis revealed that the ΔD slope rapidly decreases with Mn, and the ΔD intercept becomes constant above 1.1×10(4) g/mol. Those results indicated that the resonant length of PEG molecules moving with the oscillating plate at 9 MHz is 97.6 Å. We also found that the difference between the resonant lengths calculated from ΔD and series resonance-frequency shift, ΔF, is related to the density of the thin PEG layer formed on the gold electrode.

A case of postpartum spontaneous coronary artery dissection.

Spontaneous coronary artery dissection is rare and usually affects younger women in the peripartum period. Here, we report an interesting case of a 34-year-old woman with spontaneous coronary artery dissection that occurred 1 month after childbirth. Emergency coronary angiography showed stenosis of the left anterior descending artery, but immediately afterwards, a new occlusion of the right coronary artery occurred. Intravascular ultrasound was used to image both right and left coronary arteries. The new occlusion of the right coronary artery was probably iatrogenic, but the left coronary artery occlusion was spontaneous. The patient underwent percutaneous coronary intervention in the right coronary artery because of her unstable hemodynamic condition. Revascularization of the left coronary artery was performed by bypass grafting. The patient was discharged on postoperative day 30. As the optimal treatment for spontaneous coronary artery dissection has not yet been established, treatments should be based on the patient's clinical presentation.

Design and fabrication of biosensing interface for waveguide-mode sensor.

In order to develop a biosensing system with waveguide-mode sensor, fabrication of a biosensing interface on the silica surface of the sensing chip was carried out using triethoxysilane derivatives with anti-leptin antibody. Triethoxysilane derivatives bearing succinimide ester and oligoethylene glycol moieties were synthesized to immobilize the antibody and to suppress nonspecific adsorption of proteins, respectively. The chip modified with triethoxysilane derivatives bearing oligoethylene glycol moiety suppressed nonspecific adsorption of proteins derived from human serum effectively by rinse with PBS containing surfactant (0.05% Tween 20). On the other hand, it was confirmed that antibody was immobilized on the chip by immersion into antibody solution to show response of antigen-antibody reaction, where the chip was modified with triethoxysilane derivatives bearing succinimide ester moiety. When the interface was fabricated with antibody and a mixture of triethoxysilane derivatives bearing succinimide ester and oligoethylene glycol moieties, the response of antigen-antibody reaction depended on composition of the mixture and enhanced with the increase of ratio for triethoxysilane derivatives bearing succinimide ester moiety reflecting the antibody concentration immobilized on the chip. While introduction of excess triethoxysilane derivatives bearing succinimide ester moiety induced nonspecific adsorption of proteins derived from human serum, the immobilized antibody on the chip kept its activity after 1-month storage in a refrigerator. Taking into consideration those factors, the biosensing interface was fabricated using triethoxysilane derivatives with anti-leptin antibody to examine performance of the waveguide-mode sensor. It was found that the detection limits for human leptin were 50 ng/mL in PBS and 100 ng/mL in human serum. The results demonstrate that the waveguide-mode sensor powered by the biosensing interface fabricated with those triethoxysilane derivatives and antibody has potential to detect several tens of nanograms per milliliter of biomarkers in human serum with an unlabeled detection method.

Surface modification of silicon oxide with trialkoxysilanes toward close-packed monolayer formation.

In order to scrutinize potential of trialkoxysilanes to form close-packed monolayer, surface modification of silicon oxide was carried out with the trialkoxysilanes bearing a ferrocene moiety for analysis by electrochemical methods. As it was found that hydrogen-terminated silicon reacts with trialkoxysilane through natural oxidation in organic solvents, where the silicon oxide layer is thin enough to afford conductivity for electrochemical analysis, hydrogen-terminated silicon wafer was immersed in trialkoxysilane solution for surface modification without oxidation treatment. Cyclic voltammetry measurements to determine surface concentrations of the immobilized ferrocene-silane on silicon surface were carried out with various temperature, concentration, solvent, and molecular structure, while the blocking effect in the cyclic voltammogram was investigated to obtain insight into density leading to the close-packed layer. The results suggested that a monolayer modification tended to occur under milder conditions when the ferrocene-silane had a longer alkyl chain, and formation of a close-packed layer to show significant blocking effect was observed. However, the surface modification proceeded even when surface concentration of the immobilized ferrocene-silane was greater than that expected for the monolayer. On the basis of these tendencies, the surface of silicon oxide modified with trialkoxysilane is considered to be a partial multilayer rather than monolayer although a close-packed layer is formed. This result is supported by the comparison with carbon surface modified with ferrocene-diazonium, in which a significant blocking effect was observed when surface concentrations of the immobilized ferrocene moiety are lower than that for silicon oxide modified with ferrocene-silane.