Improvement of osseointegration efficacy of titanium implant through plasma surface treatment.

A novel plasma treatment source for generating cylindrical plasma on the surface of titanium dental implants is developed herein. Using the titanium implant as an electrode and the packaging wall as a dielectric barrier, a dielectric barrier discharge (DBD) plasma was generated, allowing the implant to remain sterile. Numerical and experimental investigations were conducted to determine the optimal discharge conditions for eliminating hydrocarbon impurities, which are known to degrade the bioactivity of the implant. XPS measurement confirmed that plasma treatment reduced the amount of carbon impurities on the implant surface by approximately 60%. Additionally, in vitro experiments demonstrated that the surface treatment significantly improved cell adhesion, proliferation, and differentiation. Collectively, we proposed a plasma treatment source for dental implants that successfully removes carbon impurities and facilitate the osseointegration of SLA implants.

Efficacy of a novel channel-cleaning ball brush for endoscope reprocessing: a randomized controlled trial.

BACKGROUND/AIMS: Endoscopic channels are difficult to clean and can cause infection transmission. We examined the effectiveness of a newly developed channel-cleaning ball brush (BB), which is sucked into the endoscopic channel and scrapes and cleans the lumen as it passes through. METHODS: The upper and lower gastrointestinal endoscopes used for patient examinations were randomly selected as the conventional brush (CB) or BB group. After manual cleaning, the presence or absence of carbohydrates, proteins, adenosine triphosphate, and hemoglobin was assessed. RESULTS: Fifty-six and 58 endoscopes were cleaned with the CB and BB, respectively. Carbohydrate and protein were detected in one (1.8%) and two endoscopes (3.4%) in the CB and BB groups, respectively (p=1.000). Hemoglobin was observed in one (1.8%) and three endoscopes (5.2%) in the CB and BB groups, respectively (p=0.636). The adenosine triphosphate levels were 10.6±15.9 and 12.5±14.3 relative light units in the CB and BB groups, respectively (p=0.496). Twenty-seven (48.2%) and 19 (32.8%) endoscopes were positive for microbial cultures in the CB and BB groups, respectively (p=0.136). CONCLUSION: The efficacy of BB was not significantly different from that of CB in the endoscopic channel-cleaning process.

Forced convective heating for low-temperature sterilization.

A novel impermeable sterile pouch is developed to allow the forced convective heating mechanism for improving the sterilization cycle. The heating process is parametrically investigated to obtain an optimized condition in which a sterilization load is heated from 20 to 45 °C within 2 min, and the forced convection is experimentally and numerically analyzed to find that the convection coefficient is dramatically increased to 450 W/m2 K when compared with the conventional natural convection coefficient of 80 W/m2 K. The optimized heating process is applied to a sterilization cycle using the impermeable pouch, and the overall sterilization cycle is found to be completed within 7.5 min whose performance is validated by using a process challenge device.

Surface plasma with an inkjet-printed patterned electrode for low-temperature applications.

The global health crisis caused by the recent pandemic has led to increasing social demand for 'new normal' sanitizing and disinfecting facilities to fit our 'new normal' lives. Here, we introduce an inkjet-printed, thin-film plasma source applicable to dry disinfection processes. In contrast to conventional plasma reactors, the merits of plasma produced on a film include disposability, cost-effectiveness, and applicability to high-dimensional objects such as the human body. The developed flexible plasma film can be applied to a wide variety of shapes via origami-remaining plasma stable even when bent. However, electrode degradation has been a practical issue in the long-term operation of inkjet-printed plasma sources, which is troublesome from application perspectives. We focus on making the inkjet-printed electrode more plasma stress-resistant, thereby increasing its lifespan from a few minutes to two hours of continuous operation with optimal inkjet printing and passivation, thus increasing the practicality of the source. Considering the fact that ozone and nitrogen oxides are selectively produced by plasma, we implement a disposable pouch-type plasma source and examine its usefulness in extending the shelf life of food.

Stabilization of liquid instabilities with ionized gas jets.

Impinging gas jets can induce depressions in liquid surfaces, a phenomenon familiar to anyone who has observed the cavity produced by blowing air through a straw directly above a cup of juice. A dimple-like stable cavity on a liquid surface forms owing to the balance of forces among the gas jet impingement, gravity and surface tension1,2. With increasing gas jet speed, the cavity becomes unstable and shows oscillatory motion, bubbling (Rayleigh instability) and splashing (Kelvin-Helmholtz instability)3,4. However, despite its scientific and practical importance-particularly in regard to reducing cavity instability growth in certain gas-blown systems-little attention has been given to the hydrodynamic stability of a cavity in such gas-liquid systems so far. Here we demonstrate the stabilization of such instabilities by weakly ionized gas for the case of a gas jet impinging on water, based on shadowgraph experiments and computational two-phase fluid and plasma modelling. We focus on the interfacial dynamics relevant to electrohydrodynamic (EHD) gas flow, so-called electric wind, which is induced by the momentum transfer from accelerated charged particles to neutral gas under an electric field. A weakly ionized gas jet consisting of periodic pulsed ionization waves5, called plasma bullets, exerts more force via electrohydrodynamic flow on the water surface than a neutral gas jet alone, resulting in cavity expansion without destabilization. Furthermore, both the bidirectional electrohydrodynamic gas flow and electric field parallel to the gas-water interface produced by plasma interacting 'in the cavity' render the surface more stable. This case study demonstrates the dynamics of liquids subjected to a plasma-induced force, offering insights into physical processes and revealing an interdependence between weakly ionized gases and deformable dielectric matter, including plasma-liquid systems.

Identification of 8-Digit HLA-A, -B, -C, and -DRB1 Allele and Haplotype Frequencies in Koreans Using the One Lambda AllType Next-Generation Sequencing Kit.

BACKGROUND: Recent studies have successfully implemented next-generation sequencing (NGS) in HLA typing. We performed HLA NGS in a Korean population to estimate HLA-A, -B, -C, and -DRB1 allele and haplotype frequencies up to an 8-digit resolution, which might be useful for an extended application of HLA results. METHODS: A total of 128 samples collected from healthy unrelated Korean adults, previously subjected to Sanger sequencing for 6-digit HLA analysis, were used. NGS was performed for HLA-A, -B, -C, and -DRB1 using the AllType NGS kit (One Lambda, West Hills, CA, USA), Ion Torrent S5 platform (Thermo Fisher Scientific, Waltham, MA, USA), and Type Steam Visual NGS analysis software (One Lambda). RESULTS: Eight HLA alleles showed frequencies of ≥10% in the Korean population, namely, A*24:02:01:01 (19.5%), A*33:03:01 (15.6%), A*02:01:01:01 (14.5%), A*11:01:01:01 (13.3%), B*15:01:01:01 (10.2%), C*01:02:01 (19.9%), C*03:04:01:02 (11.3%), and DRB1*09:01:02 (10.2%). Nine previous 6-digit HLA alleles were further identified as two or more 8-digit HLA alleles. Of these, eight alleles (A*24:02:01, B*35:01:01, B*40:01:02, B*55:02:01, B*58:01:01, C*03:02:02, C*07:02:01, and DRB1*07:01:01) were identified as two 8-digit HLA alleles, and one allele (B*51:01:01) was identified as three 8-digit HLA alleles. The most frequent four-loci haplotype was HLA-A*33:03:01-B*44:03:01:01-C*14:03-DRB1*13:02:01. CONCLUSIONS: We identified 8-digit HLA-A, -B, -C, and -DRB1 allele and haplotype frequencies in a healthy Korean population using NGS. These new data can be used as a representative Korean data for further disease-related HLA type analysis.

Performance of Norudia Glycated Albumin Assay on Multiple Analytical Platforms and Comparison to Lucica Assay.

BACKGROUND: The Norudia glycated albumin (GA) assay was evaluated for analytical performance and assay applicability on multiple analytical platforms. METHODS: The evaluation included precision, linearity, reference interval, and comparison with Lucica GA assay. A multicenter study was conducted to compare the results of Norudia GA assay on five kinds of widely used automated clinical chemistry analyzers. RESULTS: Within-laboratory imprecisions for GA% presented 1.3 - 3.3% and 0.8 - 2.6% for low- and high-level control materials, respectively, on different analyzers. GA assay was linear from 20.0 to 680.0 µmol/L of GA. The claimed reference range (12 - 16 GA%) was verified. Norudia GA showed a good GA% correlation with Lucica GA (correlation coefficient 0.999). GA% from each analyzer showed good correlation with the consensus mean of the results of five analyzers (correlation coefficient 0.997 - 0.999). CONCLUSIONS: The Norudia GA assay can successfully be implemented in all the tested platforms, with good GA% correlation.

9G TestTM Cancer/Lung: A Desirable Companion to LDCT for Lung Cancer Screening.

A complimentary biomarker test that can be used in combination with LDCT for lung cancer screening is highly desirable to improve the diagnostic capacity of LDCT and reduce the false-positive rates. Most importantly, the stage I lung cancer detection rate can be dramatically increased by the simultaneous use of a biomarker test with LDCT. The present study was conducted to evaluate 9G testTM Cancer/Lung's sensitivity and specificity in detecting Stage 0~IV lung cancer. The obtained results indicate that the 9G testTM Cancer/Lung can detect lung cancer with overall sensitivity and specificity of 75.0% (69.1~80.3) and 97.3% (95.0~98.8), respectively. The detection of stage I, stage II, stage III, and stage IV cancers with sensitivities of 77.5%, 78.1%, 67.4%, and 33.3%, respectively, at the specificity of 97.3% have never been reported before. The receiver operating characteristic curve analysis allowed us to determine the population-weighted AUC of 0.93 (95% CI, 0.91-0.95). These results indicate that the 9G testTM Cancer/Lung can be used in conjunction with LDCT to screen lung cancer. Furthermore, obtained results indicate that the use of 9G testTM Cancer/Lung with LDCT for lung cancer screening can increase stage I cancer detection, which is crucial to improve the currently low 5-year survival rates.

ABO-incompatible kidney transplantation can be successfully conducted by monitoring IgM isoagglutinin titers during desensitization.

BACKGROUND: Recent advances in desensitization techniques and immunosuppressive therapy have led to improved outcomes after ABO-incompatible (ABO-i) kidney transplantation (KT). However, questions remain unanswered, particularly regarding which type of ABO isoagglutinin-immunoglobulin M (IgM) or immunoglobulin M (IgG)-is significantly involved in antibody-mediated rejection (AMR). STUDY DESIGN AND METHODS: We retrospectively analyzed data from 120 patients who underwent ABO-i KT between 2012 and 2014. Preoperative plasma exchange was performed until the IgM isoagglutinin titer was 4 or less, regardless of the IgG titer. Clinical data were compared between patient groups with pre-KT IgG isoagglutinin titer 16 or greater (high IgG; titer range, 16-256; n = 39) and 8 or less (low IgG; titer range, -8; n = 81). RESULTS: The median follow-up periods were 59 (high IgG) and 55 (low IgG) months. Patient survival at 5 years (p = 0.314) was 100% (high IgG) and 97.4% (low IgG). Graft survival at 5 years (p = 0.480) was 100% (high IgG) and 98.7% (low IgG). AMR by anti-ABO antibody occurred in only one patient in the low-IgG group. CONCLUSION: Patients with high pre-KT IgG isoagglutinin titers had equally successful outcomes as those with low IgG titers. ABO-i KT can be successfully performed by reducing the pre-KT IgM isoagglutinin titer to 4 or less, as determined by the immediate spin tube method.

Signal to noise ratio of upgraded imaging bolometer for KSTAR.

An InfraRed imaging Video Bolometer (IRVB) was installed on KSTAR in 2012 having a ∼2 µm × 7 cm × 9 cm Pt foil blackened with graphite and a 5 mm × 5 mm aperture located 7.65 cm from the foil with 16 × 12 channels and a time resolution of 10 ms. The IR camera was an Indigo Phoenix (InSb, 320 × 256 pixels, 435 fps, <25 mK). In 2017, the IRVB was upgraded by replacing the IR camera with a FLIR SC7600 (InSb, 640 × 512 pixels, 105 fps, <25 mK). The aperture area was reduced by approximately half to 3.5 mm × 3.5 mm, and the number of channels was quadrupled to 32 × 24. A synthetic image derived using the projection matrix for the upgraded IRVB from a Scrape Off Layer Plasma Simulator (SOLPS) model with 146 kW of total radiated power had a maximum signal of 7.6 W/m2 and a signal to noise ratio (SNR) of 11. Experimental data for a plasma with parameters similar to the SOLPS model (total radiated power of 158 kW) had a maximum signal of 12.6 W/m2 and noise equivalent power density (SNR) of 0.9 W/m2 (14).

Forward projection matrix derivation through Monte-Carlo ray-tracing of KSTAR infra-red imaging video bolometer (IRVB).

The infrared imaging video bolometer (IRVB) as a foil bolometry technique can be an alternative solution to the conventional resistive bolometer due to its electro-magnetic immunity and 2D plasma profiles. The plasma profile of the IRVB cannot be directly derived from the foil images due to the difference between the foil pixel number and the plasma pixel number and the line integrated nature of the incident rays on the foil. So, it needs tomography such as the Phillips-Thikhonov algorithm. The projection matrix constructing the foil image from the plasma very directly influences the tomography. So, the projection matrix needs to be constructed precisely. For the technique calculating the precise projection matrix, a forward Monte-Carlo ray-tracing method is proposed here, and this technique can provide the detailed descriptions of the foil image. And it can give enhanced performance in the reconstructions of the plasmas with spatially localized power.

Reconstruction of radiation profiles near the plasma boundary using an infrared imaging video bolometer in KSTAR.

An infrared imaging video bolometer using tomographic inversion can provide the total radiated power and 2-D radiation profiles, which are crucial information for impurity seeding experiments. Because large amounts of impurities exist at the plasma edge, accurate reconstruction of the radiation profiles near the material boundary is an important issue. In this study, two methods of boundary condition treatment are compared. One involves the exclusion of plasma pixels outside the boundary before reconstruction, whereas the other excludes these pixels after reconstruction. Phantom reconstruction tests are performed with D-shaped and divertor radiation profiles, and the second method shows an improvement in the boundary-reconstruction results compared with the first method. Using the second method, the radiation profiles of krypton (Kr) seeded H-mode plasmas in KSTAR are reconstructed. A significant amount of input power is dissipated through the Kr radiation. The 2-D reconstructed radiation profiles show that Kr mostly accumulates at the plasma core rather than at the edge.

Electron heating in rf capacitive discharges at atmospheric-to-subatmospheric pressures.

Electron heating is a fundamental and multidisciplinary phenomenon in partially ionized gases, from the planet's ionosphere to laboratory-scale plasmas. Plasmas produced at ambient or reduced pressures have recently shown potential for scientific and industrial applications. However, electron heating, which is strongly coupled to the physicochemical properties of these plasmas, has been poorly understood. We experimentally found the rapid structural transition from non-local to local electron heating in collisional radio-frequency discharges at atmospheric-to-subatmospheric pressures. As the gas pressure decreased from 760 to 200 Torr, the time-averaged electron density increased from 1.3 × 1012 to 1.3 × 1013 cm-3, and the electron temperature decreased from 2.5 to 1.1 eV at the maximum allowable discharge current in the abnormal α-mode in the plasma bulk. The spatiotemporal evolution of the electron temperature clearly shows that the electron temperature increases uniformly throughout the bulk plasma region during sheath expansion and collapse at 760 Torr, but the electron heating weakens with sheath collapse as the gas pressure decreases.

Electron Information in Single- and Dual-Frequency Capacitive Discharges at Atmospheric Pressure.

Determining the electron properties of weakly ionized gases, particularly in a high electron-neutral collisional condition, is a nontrivial task; thus, the mechanisms underlying the electron characteristics and electron heating structure in radio-frequency (rf) collisional discharges remain unclear. Here, we report the electrical characteristics and electron information in single-frequency (4.52 MHz and 13.56 MHz) and dual-frequency (a combination of 4.52 MHz and 13.56 MHz) capacitive discharges within the abnormal α-mode regime at atmospheric pressure. A continuum radiation-based electron diagnostic method is employed to estimate the electron density (ne) and temperature (Te). Our experimental observations reveal that time-averaged ne (7.7-14 × 1011 cm-3) and Te (1.75-2.5 eV) can be independently controlled in dual-frequency discharge, whereas such control is nontrivial in single-frequency discharge, which shows a linear increase in ne and little to no change in Te with increases in the rf input power. Furthermore, the two-dimensional spatiotemporal evolution of neutral bremsstrahlung and associated electron heating structures is demonstrated. These results reveal that a symmetric structure in electron heating becomes asymmetric (via a local suppression of electron temperature) as two-frequency power is simultaneously introduced.

The creation of electric wind due to the electrohydrodynamic force.

Understanding the interactions between ionized matter and neutral particles is a prerequisite for discovering their impact on natural phenomena. One such phenomenon is the electric wind, which supposedly occurs due to the charged particle-neutral coupling in systems of weakly ionized gases, but this mechanism remains unclear. Here, we report direct evidence that electric wind is caused by an electrohydrodynamic force generated by the charged particle drag as a result of the momentum transfer from electrons/ions to neutrals. The model experiment is based on a pulsed plasma jet as a source of weakly ionized gases generated in the helium gas at atmospheric pressure using Schlieren photography. Studying the helium gas flow trajectories at different discharge parameters allows one to distinguish between the effects of streamer propagation or space charge drift causing the electric wind as well as to determine the role of electrons and (positive) ions in wind generation.

Plasma-Functionalized Solution: A Potent Antimicrobial Agent for Biomedical Applications from Antibacterial Therapeutics to Biomaterial Surface Engineering.

Deadly diseases caused by pathogenic bacteria and viruses have increasingly victimized humans; thus, the importance of disinfection has increased in medical settings as well as in food and agricultural industries. Plasma contains multiple bactericidal agents, including reactive species, charged particles, and photons, which can have synergistic effects. In particular, the chemicals formed in aqueous solution during plasma exposure have the potential for high antibacterial activity against various bacterial infections. Here, we report the antibiotic potency of plasma-treated water (PTW). To illustrate the applicability of PTW for disinfecting biological substances, an Escherichia coli biofilm was used. We sought to identify the chemical species in PTW and investigate their separate effects on biofilm removal. Dielectric barrier discharge in ambient air was used to prepare the PTW and treat the biofilm directly. Hydrogen peroxide, ozone, and nitrites were identified as the long-lived reactive species in the PTW, whereas hydroxyl radicals and superoxide anions were identified as the short-lived reactive species in the PTW; all these species showed an ability to disinfect in biofilm removal.

Compact advanced extreme-ultraviolet imaging spectrometer for spatiotemporally varying tungsten spectra from fusion plasmas.

A compact advanced extreme-ultraviolet (EUV) spectrometer operating in the EUV wavelength range of a few nanometers to measure spatially resolved line emissions from tungsten (W) was developed for studying W transport in fusion plasmas. This system consists of two perpendicularly crossed slits-an entrance aperture and a space-resolved slit-inside a chamber operating as a pinhole, which enables the system to obtain a spatial distribution of line emissions. Moreover, a so-called v-shaped slit was devised to manage the aperture size for measuring the spatial resolution of the system caused by the finite width of the pinhole. A back-illuminated charge-coupled device was used as a detector with 2048 × 512 active pixels, each with dimensions of 13.5 × 13.5 µm2. After the alignment and installation on Korea superconducting tokamak advanced research, the preliminary results were obtained during the 2016 campaign. Several well-known carbon atomic lines in the 2-7 nm range originating from intrinsic carbon impurities were observed and used for wavelength calibration. Further, the time behavior of their spatial distributions is presented.

Effects of therapeutic plasma exchange on early allograft dysfunction after liver transplantation.

BACKGROUND: Early allograft dysfunction (EAD) is a serious complication of liver transplantation (LT) and is associated with graft failure, which can result in patient mortality. Due to the shortage of organs for retransplantation, only a small proportion of EAD patients undergo retransplantation. Thus, liver support is needed for most patients with EAD. METHODS: We evaluated the effects of therapeutic plasma exchange (TPE) in EAD patients. EAD was defined as a sustained hyperbilirubinemia (≥10 mg/dL) within 30 days of LT without concurrent biliary complications. In a 13-year period, 107 EAD patients underwent TPE while 36 EAD patients did not. We investigated the laboratory and clinical outcomes of TPE and non-TPE groups. RESULTS: The TPE group showed 1-month and 1-year survival rates of 82.2% and 53.8%, respectively, whereas the non-TPE group showed 58.3% and 22.2%, respectively. In TPE group, statistically significant decreases (P < 0.05) in total bilirubin (15.2 ± 5.2 to 13.1 ± 5.4 mg/dL), and INR (1.72 ± 1.04 to 1.38 ± 1.14), were seen after the final TPE session. TPE responder groups with age <51 years, total bilirubin <11.1 mg/dL, or INR <1.15 after final TPE showed better prognosis. TPE decreased the hazard risk of death in EAD patients whereas older age, male gender, and higher INR on the day of EAD onset increased the risk. CONCLUSIONS: TPE effectively removed plasma bilirubin and improved coagulation function in EAD patients, with higher survival in the TPE group than in the non-TPE group. TPE may be an effective liver support for EAD patients. J. Clin. Apheresis 32:147-153, 2017. © 2016 Wiley Periodicals, Inc.

Flexible thin-layer plasma inactivation of bacteria and mold survival in beef jerky packaging and its effects on the meat's physicochemical properties.

The aims of the present study were to examine the use of a flexible thin-layer plasma system in inactivating bacteria and mold on beef jerky in a commercial package and to evaluate the physicochemical changes of the jerky. After plasma treatment for 10min, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Aspergillus flavus populations on the beef jerky were reduced by approximately 2 to 3Log CFU/g. No significant changes in metmyoglobin content, shear force, and myofibrillar fragmentation index were found in the plasma-treated beef jerky. On the other hand, the peroxide content and L⁎ value were decreased whereas the a⁎ and ΔE value were increased in the plasma-treated sample. Sensory evaluation indicated negative effects of plasma treatment on flavor, off-odor, and overall acceptability of the beef jerky. In conclusion, the flexible thin-layer plasma system could be employed as a means for decontamination of beef jerky, with slight changes to the physicochemical quality of the product.