Diamond-like carbon coating to inner surface of polyurethane tube reduces Staphylococcus aureus bacterial adhesion and biofilm formation.

Staphylococcus aureus is one of the main causative bacteria for polyurethane catheter and artificial graft infection. Recently, we developed a unique technique for coating diamond-like carbon (DLC) inside the luminal resin structure of polyurethane tubes. This study aimed to elucidate the infection-preventing effects of diamond-like carbon (DLC) coating on a polyurethane surface against S. aureus. We applied DLC to polyurethane tubes and rolled polyurethane sheets with our newly developed DLC coating technique for resin tubes. The DLC-coated and uncoated polyurethane surfaces were tested in smoothness, hydrophilicity, zeta-potential, and anti-bacterial properties against S. aureus (biofilm formation and bacterial attachment) by contact with bacterial fluids under static and flow conditions. The DLC-coated polyurethane surface was significantly smoother, more hydrophilic, and had a more negative zeta-potential than did the uncoated polyurethane surface. Upon exposure to bacterial fluid under both static and flow conditions, DLC-coated polyurethane exhibited significantly less biofilm formation than uncoated polyurethane, based on absorbance measurements. In addition, the adherence of S. aureus was significantly lower for DLC-coated polyurethane than for uncoated polyurethane under both conditions, based on scanning electron microscopy. These results show that applying DLC coating to the luminal resin of polyurethane tubes may impart antimicrobial effects against S. aureus to implantable medical polyurethane devices, such as vascular grafts and central venous catheters.

Comprehensive hemocompatibility analysis on the application of diamond-like carbon to ePTFE artificial vascular prosthesis.

The aim of this study was to obtain comprehensive data regarding the hemocompatibility of diamond-like carbon (DLC)-coated expanded polytetrafluoroethylene (ePTFE). DLC increased the hydrophilicity and smoothened the surface and fibrillar structure, respectively, of the ePTFE. DLC-coated ePTFE had more albumin and fibrinogen adsorption and less platelet adhesion than uncoated ePTFE. There were scarce red cell attachments in in vitro human and in vivo animal (rat and swine) whole blood contact tests in both DLC-coated and uncoated ePTFE. DLC-coated ePTFE had a similar but marginally thicker band movement than uncoated-ePTFE with SDS-PAGE after human whole blood contact test. In addition, survival studies of aortic graft replacement in rats (1.5 mm graft) and arteriovenous shunt in goats (4 mm graft) were performed to compare the patency and clot formation between DLC-coated and uncoated ePTFE grafts. Comparable patency was observed in both animal models. However, clots were observed in the luminal surface of the patent 1.5 mm DLC-coated ePTFE grafts, but not in that of uncoated ePTFE grafts. In conclusions, hemocompatibility of DLC-coated ePTFE was high and comparable to that of uncoated ePTFE. However, it failed to improve the hemocompatibility of 1.5 mm ePTFE graft probably because increased fibrinogen adsorption canceled the other beneficial effects of DLC.

A Multicenter, Prospective, Non-randomized Study Evaluating Surgical hand Preparation between Double-Gloving and Single-Gloving for Preventing Postoperative Infection in Robotic and Laparoscopic Minimally Invasive Surgeries.

PURPOSE: This study aimed to analyze a feasible and suitable surgical precautionary preparatory technique. The techniques of double-gloving with hygienic hand wash (DH) and single-gloving with surgical hand wash (SS) were compared for their ability to prevent postoperative infection in robotic and laparoscopic minimally invasive surgeries. MATERIALS AND METHODS: A prospective, non-randomized, multicenter study was conducted between January 2016 and June 2020. We divided the robotic and laparoscopic cases into two groups: DH and SS. Data on infectious outcomes were collected. Propensity score matching was performed to control for operative characteristics between the two groups. The primary endpoint was the presence of fever and surgical site infections (SSIs) indicating postoperative infection. RESULTS: Among four medical centers, seven surgeons were allocated to either the DH or the SS group. A total of 221 and 251 patients underwent DH and SS, respectively. Propensity score matching, which included 171 cases from each group, showed that the incidence of fever during hospitalization was significantly lower in the DH group than that in the SS group (11.7% vs. 23.4%, p=0.007). Multivariable analysis revealed that DH was associated with a reduced odds ratio for developing postoperative fever during hospitalization (risk ratio: 0.49, p=0.043). No differences were found in SSI before and after hospitalization between the two groups. CONCLUSION: DH resulted in less postoperative fever and had a comparable effect in preventing SSIs. This procedure could be an alternative to the SS protocol in some minimally invasive surgeries.

Densification in transparent SiO2 glasses prepared by spark plasma sintering.

Recently, spark plasma sintering (SPS) has become an attractive method for the preparation of solid-state ceramics. As SPS is a pressure-assisted low-temperature process, it is important to examine the effects of temperature and pressure on the structural properties of the prepared samples. In the present study, we examined the correlation between the preparation conditions and the physical and structural properties of SiO2 glasses prepared by SPS. Compared with the conventional SiO2 glass, the SPS-SiO2 glasses exhibit a higher density and elastic modulus, but a lower-height first sharp diffraction peak of the X-ray total structure factor. Micro-Raman and micro-IR spectra suggest the formation of heterogeneous regions at the interface between the SiO2 powders and graphite die. Considering the defect formation observed in optical absorption spectra, reduction reaction mainly affects the densification of SPS-SiO2 glass. Hence, the reaction at the interface is important for tailoring the structure and physical properties of solid-state materials prepared by the SPS technique.

Investigation of the vibrational density of states of sodium carboxymethyl starch glass via terahertz time-domain spectroscopy.

We investigated the vibrational density of states of sodium carboxymethyl starch (CM-starch) by terahertz (THz) time-domain spectroscopy. The CM-starch showed a broad peak at ∼3 THz. The structure of the peak was similar to those corresponding to glucose-based polymer glasses possessing hydrogen bonds. The boson peak (BP) appeared at 1.16 THz at the lowest temperature and disappeared because of the existence of excess wing at higher temperatures. However, based on our novel BP frequency determination method using the inflection point of the extinction coefficient, the BP frequency showed almost no dependence on temperature. Further, the chain length dependence of the BP frequency of the glucose-based glasses showed that the BP frequency of the polymer glass was slightly lower than that of the monomer glass. The power law behaviour of the absorption coefficient suggested the existence of fractons, and the fractal dimension was estimated to be 2.33.

Risk Factors for Failure of Endoscopic Management of Stone-related Ureteral Strictures.

PURPOSE: To investigate factors determining the outcomes of endoscopic management for stone-related ureteral stricture. MATERIALS AND METHODS: Data of patients who underwent endoscopic surgery for ureteral stricture due to stones from January 2016 to April 2020 were retrospectively analyzed. We compared cases successfully treated with endoscopic surgery with cases that resulted in failure. We focused on factors associated with treatment success, including cause and length of stricture, methods of stricture treatment, surgical time, and duration of hydronephrosis before the treatment. Treatment success was defined as improvement in hydronephrosis status. RESULTS: Nineteen patients were treated for stone-related ureteral stricture. Hydronephrosis was successfully improved in 12 patients (63.2%). Seven patients with failed endoscopic management had ureteroscopic lithotripsy- related stricture, whereas 3/12 (25.0%) patients with ureteroscopic lithotripsy-related stricture and 7/12 (58.3%) patients with impacted stone-related stricture were successfully treated by endoscopic management (P = .004). The prevalence of stricture length > 15 mm was significantly higher in the patients with failed management than in the patients with successful management (71.4 vs 16.6%, P = .046). Intraoperative endoscopic observation demonstrated that the mucosa of the ureteroscopic lithotripsy-related stricture had ischemic appearance with relatively long stricture length (P = 0.13) compared to the impacted stone-related stricture. No association was observed between treatment outcome and method of endoscopic management, including laser incision, balloon dilation, or both. CONCLUSION: Ureteroscopic lithotripsy as a cause and stricture length > 15 mm could affect the success rate of endoscopic management of ureteral stricture. In such cases, reconstructive management should probably be considered in the early stages.

Examination of structure and optical properties of Ce3+-doped strontium borate glass by regression analysis.

Amorphous materials with non-periodic structures are commonly evaluated based on their chemical composition, which is not always the best parameter to evaluate physical properties, and an alternative parameter more suitable for performance evaluation must be considered. Herein, we quantified various structural and physical properties of Ce-doped strontium borate glasses and studied their correlations by principal component analysis. We found that the density-driven molar volume is suitable for the evaluation of structural data, while chemical composition is better for the evaluation of optical and luminescent data. Furthermore, the borate-rich glasses exhibited a stronger luminescence due to Ce3+, indicating a higher fraction of BO3/2 ring and larger cavity. Moreover, the internal quantum efficiency was found to originate from the local coordination states of the Ce3+ centres, independent of composition or molar volume. The comparison of numerical data of the matrix is useful not only for ensuring the homogenous doping of amorphous materials by activators, but also for determining the origin of physical properties.

Dynamical Collectivity and Nuclear Quantum Effects on the Intermolecular Stretching Mode of Liquid Water.

This study investigated the broadband terahertz and low-frequency Raman spectroscopy of liquid water (H2O, D2O, and H218O) over 2 decades of frequency to address long-standing challenges regarding the interpretation of the intermolecular stretching mode at around 5 THz. We experimentally demonstrated that the intermolecular stretching mode of liquid water obtained via terahertz spectroscopy is significantly redshifted and broadened compared with that via Raman. This result was rationalized by the enhanced dynamical collectivity probed by terahertz spectroscopy, although both have a common origin in the kinetic motion. Their temperature and isotope dependences emphasize the significance of oscillation mass in determining the intermolecular stretching lineshape, while quantum effects cannot be overlooked in both terahertz and low-frequency Raman spectra.

Detection of boson peak and fractal dynamics of disordered systems using terahertz spectroscopy.

The boson peak is a largely unexplained excitation found universally in the terahertz vibrational spectra of disordered systems; the so-called fracton is a vibrational excitation associated with the self-similar structure of monomers in polymeric glasses. We demonstrate that such excitations can be detected using terahertz spectroscopy. In the case of fractal structures, we determine the infrared light-vibration coupling coefficient for the fracton region and show that information concerning the fractal and fracton dimensions appears in the exponent of the absorption coefficient. Finally, using terahertz time-domain spectroscopy and low-frequency Raman scattering, we experimentally observe these universal excitations in a protein (lysozyme) system that has an intrinsically disordered and fractal structure and argue that the system should be considered a single supramolecule. These findings are applicable to amorphous and fractal objects in general and will be valuable for understanding universal dynamics of disordered systems via terahertz light.

Surgical hand hygiene and febrile urinary tract infections in endourological surgery: a single-centre prospective cohort study.

Surgical hand hygiene reduces the risk of surgical site infections (SSIs). SSIs are not considered an issue in endourological surgery, whereas febrile urinary tract infections (f-UTIs) and urological sepsis are becoming problematic. We wondered whether surgical hand hygiene is necessary for endourological surgery. Therefore, we aimed to evaluate the influence of surgical hand hygiene on f-UTI onset in endourological surgery by comparing procedures in which surgical hand hygiene with double gloving was used with those in which regular hand hygiene with double gloving was used between April 2016 and July 2020. In this prospective cohort study of 477 patients who underwent endourological surgeries, surgeons in the surgical hand hygiene and regular hygiene groups performed surgery on 259 and 218 patients, respectively. There was no significant difference in patient background, and multivariate analyses revealed no significant differences in f-UTI onset (odds ratio, 0.87; p = 0.74) between the two groups. In conclusion, regular hand hygiene with double gloving may be considered an alternative to surgical hand hygiene to prevent endourological f-UTIs, which could alter operational protocols for endourological surgery. Further studies are needed to validate our findings.

Photocatalytic hydrogen generation of monolithic porous titanium oxide-based glass-ceramics.

A large relative surface area is crucial for high catalytic activity. Monolithic catalysts are important catalytic materials because of minimal self-degradation. Regarding large surface area catalysts, the glass-ceramics (GCs) with high formability, obtained by heat-treatment of the precursor glass, are plausible candidates. This study examines the photocatalytic behaviour of porous GCs obtained after acid leaching of MgO-TiO2-P2O5 GCs. After heat-treatment, anatase TiO2 was precipitated along with other phases. The diffraction intensity ratio between anatase and other phases was the maximum for a heat-treatment temperature of 900 °C. After acid leaching of the GCs, the relative surface area decreased with increasing TiO2 fraction; the surface area was also affected by the sample morphology. H2 generation was observed from porous GCs, while GCs without etching exhibited approximately zero activity. Thus, it was demonstrated that high surface area and prevention of the reduction reaction to Ti(III) are important for tailoring monolithic photocatalytic materials.

Antireflection in Green Lacewing Wings with Random Height Surface Protrusions.

Wings of insects exhibit many functions apart from flying. In particular, their antireflection function is important for insects to avoid detection by their enemies. This function can be applied to antireflection biomimetic films in engineering fields. For such applications, confirming the antireflection mechanisms of insect wings is important. Herein, we used electron microscopy to compare the surfaces of green lacewing wings with and without a surface wax structure and recorded the transmittance spectra to clarify the surface structural and optical properties of insect wings. The spectral transmittance was higher for wings with a surface wax structure than for wings without a wax layer in the light wavelength regime from 500 to 750 nm. We constructed a concise model of the green lacewing wing with flake-like surface structure with a graded effective refractive index corresponding to the wing samples with a surface wax layer; we also constructed a simple thin-film model corresponding to the wing samples without a wax layer. The graded refractive indices were calculated using the effective medium theory, and the transmittance spectra of such models were then calculated using the transfer-matrix method. It was observed that the calculated spectra are in good agreement with the experimental results. In addition, wing samples without a surface structure induce thin-film interference. These results suggest that a wax structure can reduce the reflectance and increase the transmittance enabling the green lacewings to avoid detection by their enemies. These findings may lead to further advances in both the biomimetic field and fundamental research fields.

Clinical impact of transcatheter atrial septal defect closure on new onset atrial fibrillation in adult patients: Comparison with surgical closure.

BACKGROUND: Previous studies demonstrated that the incidence of atrial fibrillation (AF) was significantly increased when patients aged ≥40 years had surgical atrial septal defect (ASD) closure (sASD). However, limited information is available on such findings in transcatheter ASD closure (tASD). The purpose of this study was to investigate the incidence of newly developed AF after tASD in patients aged ≥40 years in whom preoperative AF or atrial flutter (AFL) had not been detected and to compare with the incidence after sASD. METHODS: The medical records of patients aged ≥40 years without a history of AF or AFL who underwent tASD (n = 281) or sASD (n = 24) were reviewed. Patients who had catheter ablation before the ASD closure were excluded. Patients with a patent foramen ovale were also excluded. The incidence of newly developed AF after ASD closure and the risk factors for that were evaluated statistically. RESULTS: Eleven patients had newly developed AF (5 in tASD and 6 in sASD) postoperatively including 6 persistent AF (3 each after tASD and sASD). The cumulative incidence of newly developed AF was 0.7% in tASD and 16.7% in sASD, and 2.7% and 20.8% at 1 and 5 years, respectively (p < 0.001). ASD diameter ≥30 mm and sASD were potential risk factors for newly developed AF after ASD closure and postoperative persistent AF. CONCLUSIONS: In patients aged ≥40 years without a history of AF or AFL, the incidence of newly developed AF after tASD closure was lower than that after sASD. A large ASD more than 30 mm diameter was a potential risk factor for development of AF even if it is closed by transcatheter procedure. Further long-term evaluation after tASD is required to clarify preventive benefit for new onset AF in adult ASD population.

Molecular vibration and Boson peak analysis of glucose polymers and ester via terahertz spectroscopy.

Complex permittivity spectra were obtained herein by performing broadband terahertz (THz) spectroscopy on cellulose, paramylon, and paramylon ester. Absorption peaks observed for cellulose and paramylon at approximately 3 THz are attributed to hydrogen bonds. In addition, a broad absorption peak around 2 THz was observed for all the polymers, demonstrating a general feature of polymer glasses derived from weak interatomic van der Waals forces. The boson peak was observed for cellulose and paramylon ester. The boson peak frequency for cellulose nearly equaled that for glassy glucose-a unit structure of the cellulose polymer. Additionally, the insensitivity of cellulose to the polymerization degree was consistent with recent results obtained via molecular dynamics simulations. In contrast, the boson peak frequency of paramylon ester was markedly smaller than that of cellulose. These results demonstrate the importance of hydrogen bonds as determinants of the boson peak frequency.

Why Do Carbonate Anions Have Extremely High Stability in the Interlayer Space of Layered Double Hydroxides? Case Study of Layered Double Hydroxide Consisting of Mg and Al (Mg/Al = 2).

Layered double hydroxides (LDHs) are promising compounds in a wide range of fields. However, exchange of CO32- anions with other anions is necessary, because the CO32- anions are strongly affixed in the LDH interlayer space. To elucidate the reason for the extremely high stability of CO32- anions intercalated in LDHs, we investigated in detail the chemical states of CO32- anions and hydrated water molecules in the LDH interlayer space by synchrotron radiation X-ray diffraction, solid-state NMR spectroscopy, and Raman spectroscopy. We found the rigidity of the network structure formed between the CO32- anions, hydrated water molecules, and the hydroxyl groups on the metal hydroxide layer surface to be a crucial factor underlying the stability of CO32- anions in the LDH interlayer space.

Excitation of coherent optical phonons in iron garnet by femtosecond laser pulses.

We employed femtosecond pump-probe technique to investigate the dynamics of coherent optical phonons in iron garnet. A phenomenological symmetry-based consideration reveals that oscillations of the terahertz T 2g mode are excited. Selective excitation by a linearly polarized pump and detection by a circularly polarized probe confirm that impulsive stimulated Raman scattering (ISRS) is the driving force for the coherent phonons. Experimental results obtained from ISRS measurements reveal excellent agreement with spontaneous Raman spectroscopy data, analyzed by considering the symmetry of the phonon modes and corresponding excitation and detection selection rules.

Exogenous Vasohibin-2 Exacerbates Angiotensin II-Induced Ascending Aortic Dilation in Mice.

Background: Chronic angiotensin II (AngII) infusion promotes ascending aortic dilation in C57BL/6J mice. Meanwhile, vasohibin-2 (VASH2) is an angiogenesis promoter in neovascularization under various pathologic conditions. The aim of this study was to investigate whether exogenous VASH2 influences chronic AngII-induced ascending aortic dilation. Methods and Results: Eight-ten-week-old male C57BL/6J mice were injected with adenovirus (Ad) expressing either VASH2 or LacZ. One week after the injection, mice were infused with either AngII or saline s.c. for 3 weeks. Mice were divided into 4 groups: AngII+VASH2, AngII+LacZ, saline+VASH2, and saline+LacZ. Overexpression of VASH2 significantly increased AngII-induced intimal areas as well as the external diameter of the ascending aorta. In addition, VASH2 overexpression promoted ascending aortic medial elastin fragmentation in AngII-infused mice, which was associated with increased matrix metalloproteinase activity and medial smooth muscle cell (SMC) apoptosis. On western blot analysis, accumulation of apoptotic signaling proteins, p21 and p53 was increased in the AngII+VASH2 group. Furthermore, transfection of human aortic SMC with Ad VASH2 increased p21 and p53 protein abundance upon AngII stimulation. Positive TUNEL staining was also detected in the same group of the human aortic SMC. Conclusions: Exogenous VASH2 exacerbates AngII-induced ascending aortic dilation in vivo, which is associated with increased medial apoptosis and elastin fragmentation.

Numerical Analysis of Bifurcation Angles and Branch Patterns in Intracranial Aneurysm Formation.

BACKGROUND: Hemodynamic factors, especially wall shear stress (WSS), are generally thought to play an important role in intracranial aneurysm (IA) formation. IAs frequently occur at bifurcation apices, where the vessels are exposed to the impact of WSS. OBJECTIVE: To elucidate the relationship between bifurcation geometry and WSS for IA formation. METHODS: Twenty-one bifurcation models varying in branch angles and branch diameters were made with 3-dimensional computer-aided design software. In all models, the value of maximum WSS (WSSMAX), the area of high WSS (AREA), and the magnitude of wall shear force over AREA ($| {{{\vec{F}}_w}} |$) were investigated by the steady-flow simulation of computational fluid dynamics. RESULTS: On the basis of statistical analysis, WSSMAX tended to be high when the bifurcation angle and/or branch diameter was small. AREA and $| {{{\vec{F}}_w}} |$ significantly increase as the bifurcation and/or the branch angle became larger. CONCLUSION: The magnitude of WSS strongly correlated with bifurcation geometry. In addition to high WSS, AREA and $| {{{\vec{F}}_w}} |$ were thought to affect IA formation. Observed bifurcation geometry may predict IA formation. Large branch angles and small branch may increase the risk of IA formation.

[A Case of Suspected Therapy-Related Leukemia after Chemotherapy for Breast Cancer].

Therapy-related leukemia(TRL)is a distinctive clinical syndrome that occurs after exposure to chemotherapy or radiotherapy. We report a case of suspected TRLafter chemotherapy in a patient with breast cancer. A 61-year-old woman underwent total mastectomy and sentinel lymph node biopsy(negative)for her breast cancer. Histopathologic analysis showed invasive ductal carcinoma, pStage I. Her subtype histology was Luminal B-type, and postoperative adjuvant chemotherapy and endocrine therapy were administered. Four years after chemotherapy, a blood examination showed pancytopenia. Bone marrow examination showed acute promyelocytic leukemia. She was treated with chemotherapy and achieved complete remission. Breast cancer provides long-term survival after treatment. Attention should be paid to the occurrence of TRLin breast cancer surveillance.

Boson peak dynamics of natural polymer starch investigated by terahertz time-domain spectroscopy and low-frequency Raman scattering.

Terahertz time-domain spectroscopy and low-frequency Raman scattering were performed on the natural polymer starch to investigate the boson peak (BP) dynamics. In the infrared spectrum, the BP was observed at 0.99THz at the lowest temperature. Compared to the result from a previous study for vitreous glucose, both the frequency of the BP and absorption coefficient show lower values than those of the vitreous glucose. These behaviors originate from the longer correlation length of the medium-range order and lower concentration of hydroxyl groups in the starch. In the Raman spectrum, the BP was observed at 1.1THz at room temperature, although the BP was not observed around room temperature due to the excess wing of the fast relaxation modes in the infrared spectrum. The temperature dependence of ε″(ν) during the heating process and cooling process shows a hysteresis below 230K. During the heating process, kinks were observed at 140K and 230K. These kinks are attributed to the ß-relaxation and the ßwet-relaxation, respectively.