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Despite the perovskite solar cells (PSCs) have attracted attention due to their high efficiency and lower cost compared to Si solar cells, many issues remain to be addressed for the commercialization. While the perovskite light absorbing materials is relatively inexpensive, the charge transport layers such as the hole transport layer (HTL) or electron transport layer (ETL) are usually composed of expensive organic compounds. In that sense, PSCs without the charge transport layers are developed, showing very low performance due to low charge collection efficiency. In this study, we investigate the origin of low efficiency for ETL or HTL-free PSCs, and further identify the suitable front contact (either indium tin oxide (ITO) or fluorine-doped tin oxide (FTO)) for each PSC by using numerical simulation and experimental validation. The different work functions of the front contacts significantly influence charge extraction behavior, thereby affect the charge transport layer free devices. [ABSTRACT FROM AUTHOR]

The purpose of the study was to which investigate whether dexamethasone, which has anti-inflammatory and immune response suppression roles, could treat noise-induced hearing loss caused by damage to hair cells in the cochlea. The experiment used 8-week-old CBA mice exposed to white noise at an intensity of 110 dB SPL for 2 h, with hearing loss confirmed by the auditory brainstem response test. Dexamethasone was administered by intraperitoneal injection for 5 days, and the therapeutic effect was investigated for 3 weeks. The experimental groups were 3 mg/kg of dexamethasone (3 mpk) and 10 mg/kg of dexamethasone (10 mpk), and the control group was a saline-administered group. The results showed that compared to the control group, the hearing threshold value was recovered by 10 dB SPL compared to the saline group from the 14th day in the 3 mpk group. In the 10 mpk group, thresholds were recovered from the 7th day compared to the saline group. This difference was similar at 4 kHz, and in the case of the 10 mpk group, the threshold was recovered by 20 dB SPL compared to the saline group. The study also confirmed the restoration of nerve cell activity and showed a recovery effect of about 20 µV in the amplitude value change in the 10 mpk group. In conclusion, the study suggests that dexamethasone has a therapeutic effect for noise-induced hearing loss by increasing the activity of nerve cells and showing a recovery effect from hair cells damaged by noise. [ABSTRACT FROM AUTHOR]

Unlike conventional rigid-link parallel robots, cable-driven parallel robots (CDPRs) have distinct advantages, including lower inertia, higher payload-to-weight ratio, cost-efficiency, and larger workspaces. However, because of the complexity of the cable configuration and redundant actuation, model-based forward kinematics and motion control necessitate high effort and computation. This study overcomes these challenges by introducing deep reinforcement learning (DRL) into the cable robot and achieves compensated motion control by estimating the actual position of the end-effector. We used a random behavior strategy on a CDPR to explore the environment, collect data, and train neural networks. We then apply the trained network to the CDPR and verify its efficacy. We also addressed the problem of asynchronous state observation and action execution by delaying the action execution time in one cycle and adding this action to be executed to match the motion control command. Finally, we implemented the proposed control method to a high payload cable robot system and verified the feasibility through simulations and experiments. The results demonstrate that the end-effector position estimation accuracy can be improved compared with the numerical model-based forward kinematics solution and the position control error can be reduced compared with the conventional open-loop control and the open-loop control with tension distribution form. [ABSTRACT FROM AUTHOR]

This paper presents detailed geological information on the Guryongpo Subbasin in the northern part of Miocene Janggi Basin. Detailed geological mapping, stratigraphic and structural analysis, and re-analysis of previous paleomagnetic data demonstrated information on the incipient basin extension and the subsequent clockwise rotation of the Janggi Basin. The basin fills comprise conglomerate-dominated deposit, dacitic tuffs interbedded with tuffaceous sediments (ca. 23.0–22.5 Ma), and dacitic (ca. 22.8–22.4 Ma) and basaltic intrusive and extrusive rocks (ca. 20–18 Ma), in ascending order. The basin fill strata are tilted south-southeastward, and their average dip angles gradually decrease upward, indicating syn-depositional south-southeastward tilting. Extensional structures were grouped into (1) E–W- to WNW-trending basin-bounding faults, growth faults, and dacitic dikes and (2) NE- to ENE-trending (basin-bounding) normal faults and basaltic dikes. The former structures are cut by the latter ones. The paleostress field reconstruction results reveal the incipient N–S-directed and the subsequent NW–SE directed basin extensions. Re-analysis of previous paleomagnetic data based on our stratigraphic scheme demonstrates the progressive clockwise rotation of the Janggi Basin under a regional dextral simple shear regime. The above results suggest that the incipient extension of the Miocene basin in the onshore region of SE Korea occurred before 23.0 ± 0.1 Ma during the back-arc opening of the East Sea. The results also indicate that the incipient extension and the subsequent evolution of the Janggi Basin can be explained by the clockwise horizontal rotation in response to the NNW-trending regional dextral strike-slip faulting due to the opening of the sea. [ABSTRACT FROM AUTHOR]

Invadopodia are dynamic actin-rich membrane protrusions that have been implicated in cancer cell invasion and metastasis. In addition, invasiveness of cancer cells is strongly correlated with invadopodia formation, which are observed during extravasation and colonization of metastatic cancer cells at secondary sites. However, quantitative understanding of the interaction of invadopodia with extracellular matrix (ECM) is lacking, and how invadopodia protrusion speed is associated with the frequency of protrusion-retraction cycles remains unknown. Here, we present a computational framework for the characterization of invadopodia protrusions which allows two way interactions between intracellular branched actin network and ECM fibers network. We have applied this approach to predicting the invasiveness of cancer cells by computationally knocking out actin-crosslinking molecules, such as α-actinin, filamin and fascin. The resulting simulations reveal distinct invadopodia dynamics with cycles of protrusion and retraction. Specifically, we found that (1) increasing accumulation of MT1-MMP at tips of invadopodia as the duration of protrusive phase is increased, and (2) the movement of nucleus toward the leading edge of the cell becomes unstable as duration of the retractile phase (or myosin turnover time) is longer than 1 min. [ABSTRACT FROM AUTHOR]

A steel slit damper has been used to enhance the seismic performance of structures with several advantages. The damper can be easily manufactured at a low cost. Furthermore, it can dissipate a significant amount of seismic energy through the stable hysteretic behavior of steel. This study presents a preliminary investigation of the development of a composite steel slit damper that can respond effectively at multiple levels of seismic loading. The performance of the prototype composite steel slit damper is investigated in both experimental and analytical ways. In the experiments, the specimen shows the stable hysteretic response with sufficient ductility, where the multi-phased response is observed in the incremental-amplitude cyclic loading case. Furthermore, a nonlinear numerical analysis that combines both kinematic hardening and isotropic hardening models can reliably describe such characteristics. [ABSTRACT FROM AUTHOR]

The 20% ethanol extract of Polygala tenuifolia, Angelica tenuissima, and Dimocarpus longan (WIN-1001X) was derived from a modified version of Korean traditional herbal formula 'Chungsimyeolda-tang' which has been used for the treatment of cerebrovascular disorders. The Parkinson's disease presents with impaired motor functions and loss of dopaminergic neurons. However, the treatment for Parkinson's disease is not established until now. This study aims to elucidate the therapeutic advantages of WIN-1001X on animal models of Parkinson's disease. WIN-1001X administration successfully relieved the Parkinsonism symptoms in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mice tested by rota-rod and pole tests. The loss of tyrosine hydroxylase activities in substantia nigra and striatum was also attenuated by administration of WIN-1001X. In mice with sub-chronical MPTP injections, autophagy-related proteins, such as LC3, beclin-1, mTOR, and p62, were measured using the immunoblot assay. The results were favorable to induction of autophagy after the WIN-1001X administration. WIN-1001X treatment on 6-hydroxydopamine-injected rats also exhibited protective effects against striatal neuronal damage and loss of dopaminergic cells. Such protection is expected to be due to the positive regulation of autophagy by administration of WIN-1001X with confirmation both in vivo and in vitro. In addition, an active compound, onjisaponin B was isolated and identified from WIN-1001X. Onjisaponin B also showed significant autophagosome-inducing effect in human neuroblastoma cell line. Our study suggests that relief of Parkinsonism symptoms and rescue of tyrosine hydroxylase activity in dopaminergic neurons are affected by autophagy enhancing effect of WIN-1001X which the onjisaponin B is one of the major components of activity. [ABSTRACT FROM AUTHOR]

To accelerate the discovery of materials through computations and experiments, a well-established protocol closely bridging these methods is required. We introduce a high-throughput screening protocol for the discovery of bimetallic catalysts that replace palladium (Pd), where the similarities in the electronic density of states patterns were employed as a screening descriptor. Using first-principles calculations, we screened 4350 bimetallic alloy structures and proposed eight candidates expected to have catalytic performance comparable to that of Pd. Our experiments demonstrate that four bimetallic catalysts indeed exhibit catalytic properties comparable to those of Pd. Moreover, we discover a bimetallic (Ni-Pt) catalyst that has not yet been reported for H2O2 direct synthesis. In particular, Ni61Pt39 outperforms the prototypical Pd catalyst for the chemical reaction and exhibits a 9.5-fold enhancement in cost-normalized productivity. This protocol provides an opportunity for the catalyst discovery for the replacement or reduction in the use of the platinum-group metals. [ABSTRACT FROM AUTHOR]

The feasibility of surfactants for enhancement of extraction efficiencies in wet oil extraction through an acidic hydrothermal process was evaluated. Three different types of surfactants were tested: anionic (SDBS and SDS), cationic (CTAB and MBC), and non-ionic (IGEPAL CA-210 and Tween 60). The total fatty acid content of Chlorella vulgaris was 291.0 mg/g cell. Under the no-surfactant condition, the oil-extraction yield of the acidic hydrothermal extraction was 75.5%. The addition of SDBS and MBC at the 0.4% concentration showed enhanced oil-extraction performance, 85.4 and 85.7% yields, respectively. CTAB and Tween 60 showed low extraction yields, less than 43.0%. SDS and IGEPAL CA-210 showed high oil-extraction yields, higher, in fact, than the initial fatty acid content, due to surfactant partitioning into microalgal oil. With increasing surfactant concentration, the oil-extraction yields of CTAB decreased, those of IGEPAL CA-210 gradually increased, and those of SDBS increased and then decreased again. The best performance, an oil-extraction yield of 95.6%, was observed under the 0.2% SDBS, 120 °C, 1 h condition. Although IGEPAL CA-210 showed the high net oil-extraction yield of 98.3% at the 0.6% surfactant concentration, 61.2% of surfactant was partitioned into oil. [ABSTRACT FROM AUTHOR]

Although LiNi0.8Co0.15Al0.05O2 (NCA) has various merits such as a high discharge capacity of ~ 195 mAh g−1, improved stability, and low cost, intergranular cracks in the NCA structure can suppress the electronic/ionic motion in the cathode. Thus, in this study, to minimize crack portions in the NCA cathode, we synthesized dense NCA cathode materials using micelle structures controlled with pluronic acid (F127) and polyvinyl alcohol (PVA) as polymer templates and evaluated the electrochemical performance in LIBs using coin-type cells. We found that all the as-prepared samples showed the LiNiO2-based structures doped with Co and Al. With an increasing amount of PVA, the 1st particles can be more agglomerated during heating and thus increase the size of the 2nd particles. Consequently, a significantly dense NCA structure consisting of less cracked 2nd particles can be prepared in the presence of F127 and PVA. In particular, the NCA cathode prepared with an optimal ratio of F127 to PVA exhibited the best electrochemical properties, i.e., high capacity and superior cycle life. [ABSTRACT FROM AUTHOR]

We have developed the low-temperature conformal ZnO nanowire fabrication on flexible plastic substrates by utilizing the solution-processible metal seed-assisted hydrothermal ZnO crystallization. Structural evolution of ZnO nanowires controlled by major parameters involving growth temperature, growth time, and seed coating condition, has been systematically investigated towards uniform and large-area growth of conformal ZnO nanowires. Direct ZnO nanowire growth on flexible plastics without undergoing the high-temperature seed sintering has been realized by developing the low-temperature Ag-seeded hydrothermal ZnO nanowire growth. The nanoporous Ag layer favorable for ZnO crystal nucleation and continued nanowire growth can be reduced from the Ag ion solution coating at the temperature as low as 130 °C. This tactfully enables the selective hydrothermal growth of ZnO nanowires on the Ag patterns on flexible plastics. Such an all-solution-processible low-temperature fabrication protocol may provide an essential and practical solution to develop many diverse applications including wearable and transparent electronics, sensors, and photocatalytic devices. As one example, we demonstrate that a transparent UV sensor can be devised based on the ZNW growth on the Ag micromesh electrode. [ABSTRACT FROM AUTHOR]

The feasibilities of cell disruption by homogenization-assisted high-pressure nano-dispersion and recovery of astaxanthin-containing oil by oil partitioning in oil-acetone-water solution were examined. The total fatty acid content of Haematococcus pluvialis was 414.6 mg/g cell, and the astaxanthin content was 4.4% of oil. Extra oil was added to the solution in order to recover oil through instability of dispersion status instead of solvent evaporation. A total amount of energy of 0.34 kWh/L was consumed for acetone evaporation at 50 °C, whereas fully 1.86 kWh/L of energy for water evaporation was consumed. When soybean oil was added to the solution after partial acetone evaporation, the oil-recovery yield was 97.8%, while the yield after full evaporation was 97.6% in 10-g/L solution. However, the energy consumed for partial evaporation (0.29 kWh/L) was much lower than that for full evaporation (0.40 kWh/L). When H. pluvialis oil was added to the solution after partial evaporation, the oil-recovery yield decreased to 90.6% due to the impurity of crude H. pluvialis oil in 10-g/L solution. Methods such as refining of H. pluvialis oil, increase of microalgae dosage for cell disruption, and increase of the injection amount of extra oil can help to enhance oil recovery. [ABSTRACT FROM AUTHOR]

With the improvement in the accuracy of simulation and computation time, the need for the application of optimization technique in designing process parameters is increasing and is being realized in some fields. However, two obstacles are still preventing the optimization technique from being practically used in forging process. The one is the lack of quantification technique of grain flow quality and the other is difficulty in treating 3 dimensional die shape as design parameters. In this study, 3 kinds of quantification technique of grain flow quality, the overlapping index, cutting index and locally sinking index, are introduced based on the relation between grain flow and product quality. Also, a methodology of treating 3 dimensional die shape as the design parameters is introduced using discretized finite element model. [ABSTRACT FROM AUTHOR]

Since Li+ ions can transport through porous channels in the separator containing liquid electrolyte, the electrochemical and structural properties of the separator needs to be improved to develop a high rate performance lithium-ion battery (LIB). In this study, a gel-type polymer membrane using poly (vinylidene fluoride-co-hexafluoropropylene) (P (VDF-HFP)) acting as a matrix and ethylene carbonate (EC) as a separator was applied for a high-performance LIB with LiMn2O4 as a cathode. The cell assembled with the porous polymer gel electrolyte membrane prepared using P (VDF-HFP) with an appropriate amount of EC exhibited an improved capacity (78.8 mAh g−1) and energy density (308.4 mWh g−1) at a current density of 720 mA g−1, and a high capacity retention (94.8%) at a current density of 240 mA g−1, compared to the cell assembled with polyethylene as a separator. The enhanced LIB performance can result from an increased Li+-ion migration between the chains in low-crystalline polymer membranes and an increased volume of the liquid electrolyte for ionic motion in the porous membrane due to an increased porosity. [ABSTRACT FROM AUTHOR]

Abstract: To overcome the volumetric expansion of Si used as an anode in lithium-ion batteries (LIBs), we propose 3D Si electrode structures formed on patterned Cu current collectors designed from metal molds fabricated using wire electrical discharge machining (WEDM). The line- and check-patterned Cu current collectors with microscale periods for LIBs are prepared using an imprinting technique with patterned metal molds fabricated using the WEDM process. The line- and check-patterned Si thin-film and powder-type electrodes as anodes are fabricated using radio frequency magnetron sputtering deposition method and conventional slurry casting process, respectively. The morphology of the Si electrodes before and after the cycling process is characterized using optical microscopy and scanning electron microscopy. The electrochemical properties of the Si electrodes are evaluated using a multi-channel battery tester and electrochemical impedance analyzer. In particular, the check-patterned Si electrodes exhibit relatively high-capacity and enhanced cycling performance due to the stress relief of the Si anode.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Wrapping-based informed RRT*, proposed in this paper, combines a size-diminishing procedure, i.e., 'wrapping procedure' with informed RRT*, which samples random path nodes within a hyperellipsoid. The major and minor axes of the hyperellipsoid are determined by the initial and final configurations and current best solution's path cost. Wrapping-based informed RRT* can advance from the first solution acquired by the planner to an improved, feasible solution which can drastically reduce the size of the hyperellipsoid. This leads to much quicker convergence to the optimal value of the path cost, resulting in the minimum action of the robot joints. The algorithm was tested in various environments with different numbers of joint variables and showed much better performance than the existing planners. Furthermore, the wrapping procedure proved to be a comparably insignificant computational burden regardless of the number of dimensions of the configuration space. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the present study was to compare functional outcomes of medial unicompartmental knee arthroplasty (UKA) in patients with patellofemoral osteoarthritis (PF OA) and those without PF OA and to evaluate the effect of PF OA on functional outcomes after UKA.Methods: The outcomes of 48 knees in patients without PF OA who underwent medial UKA (non-PF OA group) were compared to the outcomes of 57 knees in patients with PF OA [Kellgren-Lawrence (K-L) grade ≤ 2] who underwent medial UKA (PF OA group) with a median follow-up of 5.4 years (range 3.1-10.2 years). Clinical outcomes including anterior knee pain, HSS scores, radiological parameters, and the progression of patellofemoral osteoarthritis were compared, and their effects on functional outcomes were evaluated at the final follow-up visits.Results: At final follow-up visits, no significant inter-group difference was found in terms of anterior knee pain (1.9 vs. 1.9 in non-PF OA and PF OA groups, respectively), HSS score, or range of motion. Preoperative anterior knee pain and patellofemoral joint degeneration were found to be unrelated to poor outcome in patients that underwent medial UKA. Furthermore, no correlation was found between any functional outcome variable and chondral lesion pattern.Conclusions: The result of UKA for medial unicompartmental knee osteoarthritis was excellent regardless of PF OA (K-L grade ≤ 2). Hence, the patients with medial unicompartmental OA combined with a moderate degree of anterior knee pain or patellofemoral arthritis should be viewed as appropriate candidates for medial UKA.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

The objective of this study was to review outcomes of early one-stage surgery of acutely infected preauricular sinus compared to conventional delayed surgery after infection control. The study is a case series with chart review conducted in an academic center. From January 1, 2007 to January 31, 2012, we performed surgical treatments for 136 congenital preauricular sinuses on 103 patients aged 0-15 years. We classified the sinuses according to the state of their infection at the time of the surgery intraoperatively--Group I (asymptomatic; n = 68, 50 %), Group II (infected state; n = 26, 19 %) and Group III (infected state with abscess formation; n = 42, 31 %). The surgical outcomes of Groups I, II, and III were documented during an outpatient department observation period. The follow-up period was from 6 months to over 2 years. One patient from Group II and one patient from Group III had a recurrent infection which could be managed by local infection control. One patient from Group I and one patient from Group III had skin defects by necrosis of a skin flap margin which could be secondarily healed. All patients had no recurrence or significant chronic complications. We performed early one-stage surgical treatments on a total of 136 sinuses with an even acute infection with abscess formation and achieved good surgical outcomes, and patients were satisfied in aspects of treatment period and cost. So we present our early one-stage surgical treatment as a good option for infected preauricular sinus management. [ABSTRACT FROM AUTHOR]

For successful cell culture in microfluidic devices, precise control of the microenvironment, including gas transfer between the cells and the surrounding medium, is exceptionally important. The work is motivated by a polydimethylsiloxane (PDMS) microfluidic oxygenator chip for mammalian cell culture suggesting that the speed of the oxygen transfer may vary depending on the thickness of a PDMS membrane or the height of a fluid channel. In this paper, a model is presented to describe the oxygen transfer dynamics in the PDMS microfluidic oxygenator chip for mammalian cell culture. Theoretical studies were carried out to evaluate the oxygen profile within the multilayer device, consisting of a gas reservoir, a PDMS membrane, a fluid channel containing growth media, and a cell culture layer. The corresponding semi-analytical solution was derived to evaluate dissolved oxygen concentration within the heterogeneous materials, and was found to be in good agreement with the numerical solution. In addition, a separate analytical solution was obtained to investigate the oxygen pressure drop (OPD) along the cell layer due to oxygen uptake of cells, with experimental validation of the OPD model carried out using human umbilical vein endothelial cells cultured in a PDMS microfluidic oxygenator. Within the theoretical framework, the effects of several microfluidic oxygenator design parameters were studied, including cell type and critical device dimensions. [ABSTRACT FROM AUTHOR]

Despite the importance of meju as a raw material used to make Korean soy sauce (ganjang) and soybean paste (doenjang), little is known about the bacterial diversity of Korean meju. In this study, the bacterial communities in meju were examined using both culture-dependent and independent methods in order to evaluate the diversity of the bacterial population. Analyses of the 16S rRNA gene sequences of the bacterial strains isolated from meju samples showed that the dominant species were related to members of the genera Bacillus, Enterococcus, and Pediococcus. The community DNAs extracted from nine different meju samples were analyzed by barcoded pyrosequencing method targeting of the V1 to V3 hypervariable regions of the 16S rRNA gene. In total, 132,374 sequences, with an average read length of 468 bp, were assigned to several phyla, with Firmicutes (93.6%) representing the predominant phylum, followed by Proteobacteria (4.5%) and Bacteroidetes (0.8%). Other phyla accounted for less than 1% of the total bacterial sequences. Most of the Firmicutes were Bacillus and lactic acid bacteria, mainly represented by members of the genera Enterococcus, Lactococcus, and Leuconostoc, whose ratio varied among different samples. In conclusion, this study indicated that the bacterial communities in meju were very diverse and a complex microbial consortium containing various microorganisms got involved in meju fermentation than we expected before. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) is characterized by detrimental immune reactivity in the gut, and the imbalance between proinflammatory and anti-inflammatory reactivity. The incidence and prevalence rates of IBD in Korea have been increasing rapidly during the past decades. In this study, we tried to find the new effect of fruits and branches of mulberry tree called Cheongilppong in Korea (belongs to Morus alba, Moraceae). The previous studies revealed mulberry fruits and branches had anti-oxidative effect and anti-inflammatory effect. In the present study, the fruits and branch of Cheongilppong inhibited the inflammatory responses on dextran sulfate sodium induced ulcerative colitis in mice and the production of nitrite oxide from lipopolysaccharide and interferon-gamma stimulated mouse peritoneal macrophages. These results may be relevant for future pharmacological or dietary interventions in patients with ulcerative colitis. [ABSTRACT FROM AUTHOR]

Conventional in vitro cell culture that utilizes culture dishes or microtiter plates is labor-intensive and time-consuming, and requires technical expertise and specific facilities to handle cell harvesting, media exchange and cell subculturing procedures. A microfluidic array platform with eight microsieves in each cell culture chamber is presented for continuous cell culture. With the help of the microsieves, uniform cell loading and distribution can be obtained. Within the arrays, cells grown to the point of confluency can be trypsinized and recovered from the device. Cells trapped in the microsieves after trypsinization function to seed the chambers for subsequent on-chip culturing, creating a sustainable platform for multiple cycles. The capability of the microfluidic array platform was demonstrated with a BALB/3T3 (murine embryonic fibroblast) cell line. The present microfluidic cell culture platform has potential to develop into a fully automated cell culture system integrated with temperature control, fluidic control, and micropumps, maximizing cell culture health with minimal intervention. [ABSTRACT FROM AUTHOR]

The momentum, heat and mass transfer in the silicon melt of the Czochralski crystal growth system were calculated with a three dimensional numerical simulation technique. Several types of non-axisymmetric profiles of velocities, temperature and oxygen concentration appeared in the melt with axisymmetrical boundary conditions. Since the asymmetric profiles and the rotations of fluid, temperatures and oxygen concentration fluctuated in the melt. The correlations between both fluctuations at the same point became larger, as the convection grew stronger. The calculation also showed that the temperature and oxygen concentration near the interface also fluctuated. The results suggested that the oxygen concentration could be considered one of the causes of the striation pattern in grown silicon single crystals. [ABSTRACT FROM AUTHOR]