Intratympanic steroid treatment can reduce ROS and immune response in human perilymph investigated by in-depth proteome analysis.

Intratympanic (IT) steroid treatment is one of the most widely used and effective treatments for inner ear disorders such as sudden sensorineural hearing loss (SNHL). However, a clear mechanism of IT steroids in inner ear recovery has not yet been revealed. Therefore, we investigated proteome changes in extracted human perilymph after steroid treatment. In this study, we applied a tandem mass spectrometry (MS/MS)-based proteomics approach to discover global proteome changes by comparing human perilymph after steroid treatment with non-treated perilymph group. Using liquid chromatography-MS/MS analysis, we selected 156 differentially expressed proteins (DEPs) that were statistically significant according to Student's t-test. Functional annotation analysis showed that upregulated proteins after steroid treatment are related to apoptosis signaling, as well as reactive oxygen species (ROS) and immune responses. The protein-protein interaction (PPI) clusters the proteins associated with these processes and attempts to observe signaling circuitry, which mediates cellular response after IT steroid treatments. Moreover, we also considered the interactome analysis of DEPs and observed that those with high interaction scores were categorized as having equivalent molecular functions (MFs). Collectively, we suggest that DEPs and interacting proteins in human perilymph after steroid treatment would inhibit the apoptotic and adaptive immune processes that may lead to anti-inflammatory effects.

A Bidirectional Interpolation Method for Post-Processing in Sampling-Based Robot Path Planning.

This paper proposes a post-processing method called bidirectional interpolation method for sampling-based path planning algorithms, such as rapidly-exploring random tree (RRT). The proposed algorithm applies interpolation to the path generated by the sampling-based path planning algorithm. In this study, the proposed algorithm is applied to the path created by RRT-connect and six environmental maps were used for the verification. It was visually and quantitatively confirmed that, in all maps, not only path lengths but also the piecewise linear shape were decreased compared to the path generated by RRT-connect. To check the proposed algorithm's performance, visibility graph, RRT-connect algorithm, Triangular-RRT-connect algorithm and post triangular processing of midpoint interpolation (PTPMI) were compared in various environmental maps through simulation. Based on these experimental results, the proposed algorithm shows similar planning time but shorter path length than previous RRT-like algorithms as well as RRT-like algorithms with PTPMI having a similar number of samples.

Improved RRT-Connect Algorithm Based on Triangular Inequality for Robot Path Planning.

This paper proposed a triangular inequality-based rewiring method for the rapidly exploring random tree (RRT)-Connect robot path-planning algorithm that guarantees the planning time compared to the RRT algorithm, to bring it closer to the optimum. To check the proposed algorithm's performance, this paper compared the RRT and RRT-Connect algorithms in various environments through simulation. From these experimental results, the proposed algorithm shows both quicker planning time and shorter path length than the RRT algorithm and shorter path length than the RRT-Connect algorithm with a similar number of samples and planning time.

Effect of expiratory phase for radiographic detection of left heart enlargement in dogs with mitral regurgitation.

Radiography is a standard diagnostic test for characterizing left heart enlargement in dogs however limited information is available on the effects of respiratory phases. This prospective and retrospective method comparison study investigated the respiratory effect on the size and shape of the left heart in dogs to determine the usefulness of expiratory radiographs to detect enlargements in the left atrium (LA) and left ventricle (LV). Thoracic radiographs taken at full inspiration and expiration were evaluated in 20 normal beagles and 100 dogs diagnosed with mitral regurgitation (MR). Vertebral heart score (VHS), vertebral left atrial size, elevation of the carina, and dorsal bulging of LA on lateral view and lateral bulging of the left auricular appendage and LV on ventrodorsal view were assessed. In normal dogs, there were no significant differences in the evaluative factors between inspiration and expiration. In dogs with MR, VHS did not change according to respiration. However, bulging of the LA, left auricular appendage, and LV had sharp margin during expiration compared with inspiration. The expiratory radiographic finding of LA bulging had a higher correlation with the LA to aorta ratio compared with LA bulging in the inspiratory radiography. Using a LA to aorta echocardiographic ratio greater than 1.5 as the gold standard, the radiographic sensitivity for LA enlargement was higher during expiration than inspiration. These findings of our study indicated that expiratory radiography can be helpful to support the detection of left heart enlargement, although it can overestimate LA enlargement in dogs with MR.

Water Sink Model for Robot Motion Planning.

There are various motion planning techniques for robots or agents, such as bug algorithm, visibility graph, Voronoi diagram, cell decomposition, potential field, and other probabilistic algorithms. Each technique has its own advantages and drawbacks, depending on the number and shape of obstacles and performance criteria. Especially, a potential field has vector values for movement guidance to the goal, and the method can be used to make an instantaneous and smooth robot movement path without an additional controller. However, there may be some positions with zero force value, called local minima, where the robot or agent stops and cannot move any further. There are some solutions for local minima, such as random walk or backtracking, but these are not yet good enough to solve the local minima problem. In this paper, we propose a novel movement guidance method that is based on the water sink model to overcome the previous local minima problem of potential field methods. The concept of the water sink model is to mimic the water flow, where there is a sink or bathtub with a plughole and floating piece on the water. The plughole represents the goal position and the floating piece represents robot. In this model, when the plug is removed, water starts to drain out via the plughole and the robot can always reach the goal by the water flow. The water sink model simulator is implemented and a comparison of experimental results is done between the water sink model and potential field.

Energy-Efficient Forest Fire Prediction Model Based on Two-Stage Adaptive Duty-Cycled Hybrid X-MAC Protocol.

This paper proposes an adaptive duty-cycled hybrid X-MAC (ADX-MAC) protocol for energy-efficient forest fire prediction. The Asynchronous sensor network protocol, X-MAC protocol, acquires additional environmental status details from each forest fire monitoring sensor for a given period, and then changes the duty-cycle sleep interval to efficiently calculate forest fire occurrence risk according to the environment. Performance was verified experimentally, and the proposed ADX-MAC protocol improved throughput by 19% and was 24% more energy efficient compared to the X-MAC protocol. The duty-cycle was shortened as forest fire probability increased, ensuring forest fires were detected at faster cycle rate.

A 3-D Meandered Probe-Fed Dual-Band Circularly Polarized Dielectric Resonator Antenna.

A dual-band circularly polarized (CP) dielectric resonator antenna (DRA) designed on multi-layer substrates is proposed. An asymmetric C-shaped metallic strip is also incorporated into the upper side of the top substrate in the proposed design. The hexagonal dielectric resonator (DR) is excited by the proposed 3-D meandered probe, which generates multiple orthogonal TE-modes. It is found that the lower CP band arises due to the pair of fundamental modes of the hexagonal DR. In the upper CP band, pairs of higher broadside and even modes of the hexagonal DR are combined with a CP band that is induced by the asymmetric C-shaped metallic strip to yield a wide 3 dB axial ratio bandwidth (ARBW). A prototype of the proposed DRA is fabricated for experimental verification. The antenna exhibits a measured -10 dB reflection bandwidth of 56.43% (2.15⁻3.84 GHz). The far-field measurement shows measured 3 dB ARBWs of 7.56% (2.29⁻2.47 GHz) with a peak gain of 5.6 dBic and 16.47% (3.12⁻3.68 GHz) with a peak gain of 7.84 dBic in the lower and upper bands, respectively.

An Asian traditional herbal complex containing Houttuynia cordata Thunb, Perilla frutescens Var. acuta and green tea stimulates hair growth in mice.

BACKGROUND: Houttuynia cordata Thunb (HC) is a traditional herbal medicine widely used in Asia for the treatment of patients with alopecia, usually in combination with other two herbal medicines (Perilla frutescens var. acuta (PFVA) and green tea (GT)). However, the effect of this herbal complex has not been clearly demonstrated. We sought to determine the hair growth-promoting effect of this herbal complex (HC, PFVA, and GT) in the animal model. METHODS: Six-week-old male C57BL/6 mice were randomly divided into four groups (negative control, finasteride (1 mg/kg) as a positive control, and two (200 and 400 mg/kg) concentrations of the herbal complex as experimental groups) and were fed its corresponding medications orally for 25 days. Hair growth was evaluated visually and microscopically. Western blot analysis for insulin-like growth factor (IGF)-1 and transforming growth factor (TGF)-ß1 was performed. RESULTS: The herbal complex exhibited hair growth-promoting activity in C57BL/6 mice. Grossly, the area of hair regrowth was 55.1 (±3.8) %, 70.2 (±6.3) % and 83.5 (±5.7) % in negative control, herbal complex 200 mg/kg and 400 mg/kg group, respectively. In histologic examination, the hair follicle count in deep subcutis was 2.6 (±0.7), 5.8 (±0.7) and 8.6 (±1.2) and the diameter of hair follicles was 11.9 (±5.0) µm, 17.4 (±3.9) µm and 22.8 (±5.2) µm in negative control, herbal complex 200 and 400 mg/kg group, respectively. The expression of IGF-1 was 0.14 (±0.01), 0.23 (±0.02) and 0.24 (±0.01) and the expression of TGF-ß1 was 0.26 (±0.01), 0.19 (±0.02) and 0.15 (±0.01) in negative control, the 200 and 400 mg/kg group, respectively. CONCLUSIONS: This data provides adequate preliminary experimental evidence to support the hair regeneration effect of this herbal complex.

Vertical-Strip-Fed Broadband Circularly Polarized Dielectric Resonator Antenna.

A vertical-strip-fed dielectric resonator antenna exhibiting broadband circular polarization characteristics is presented. A broad 3 dB axial ratio bandwidth (ARBW) is achieved by combining multiple orthogonal modes due to the use of a special-shaped dielectric resonator. The proposed antenna is fabricated to evaluate its actual performance capabilities. The antenna exhibits a measured 3 dB ARBW of 44.2% (3.35-5.25 GHz), lying within a -10 dB reflection bandwidth of 82.7% (2.44-5.88 GHz). The measured peak gain within 3 dB ARBW is found to be 5.66 dBic at 4.8 GHz. The measured results are in good agreement with the simulated results.

Mass spectrometric imaging of metabolites in kidney tissues from rats treated with furosemide.

In the kidney, metabolic processes are different among the cortex (COR), outer medulla (OM), and inner medulla (IM). Using matrix-assisted laser desorption/ionization (MALDI) and imaging mass spectrometry (IMS), we examined the change of metabolites in the COR, OM, and IM of the rat kidney after furosemide treatment compared with vehicle-treated controls. Osmotic minipumps were implanted in male Sprague-Dawley rats to deliver 12 mg·day(-1)·rat(-1) of furosemide. Vehicle-treated (n = 14) and furosemide-treated (furosemide rats, n = 15) rats in metabolic cages received a fixed amount of rat chow (15 g·220 g body wt(-1)·day(-1) for each rat) with free access to water intake for 6 days. At day 6, higher urine output (32 ± 4 vs. 9 ± 1 ml/day) and lower urine osmolality (546 ± 44 vs. 1,677 ± 104 mosmol/kgH2O) were observed in furosemide rats. Extracts of COR, OM, and IM were analyzed by ultraperformance liquid chromatography coupled with quadrupole time-of-flight (TOF) mass spectrometry, where multivariate analysis revealed significant differences between the two groups. Several metabolites, including acetylcarnitine, betaine, carnitine, choline, and glycerophosphorylcholine (GPC), were significantly changed. The changes of metabolites were further identified by MALDI-TOF/TOF and IMS. Their spatial distribution and relative quantitation in the kidneys were analyzed by IMS. Carnitine compounds were increased in COR and IM, whereas carnitine and acetylcarnitine were decreased in OM. Choline compounds were increased in COR and OM but decreased in IM from furosemide rats. Betaine and GPC were decreased in OM and IM. Taken together, MALDI-TOF/TOF and IMS successfully provide the spatial distribution and relative quantitation of metabolites in the kidney.

Antarctic skuas recognize individual humans.

Recent findings report that wild animals can recognize individual humans. To explain how the animals distinguish humans, two hypotheses are proposed. The high cognitive abilities hypothesis implies that pre-existing high intelligence enabled animals to acquire such abilities. The pre-exposure to stimuli hypothesis suggests that frequent encounters with humans promote the acquisition of discriminatory abilities in these species. Here, we examine individual human recognition abilities in a wild Antarctic species, the brown skua (Stercorarius antarcticus), which lives away from typical human settlements and was only recently exposed to humans due to activities at Antarctic stations. We found that, as nest visits were repeated, the skua parents responded at further distances and were more likely to attack the nest intruder. Also, we demonstrated that seven out of seven breeding pairs of skuas selectively responded to a human nest intruder with aggression and ignored a neutral human who had not previously approached the nest. The results indicate that Antarctic skuas, a species that typically inhabited in human-free areas, are able to recognize individual humans who disturbed their nests. Our findings generally support the high cognitive abilities hypothesis, but this ability can be acquired during a relatively short period in the life of an individual as a result of interactions between individual birds and humans.

Stratification of patients with intermediate-risk prostate cancer.

OBJECTIVE: To identify an appropriate risk stratification system for intermediate-risk prostate cancer (PCa). PATIENTS AND METHODS: We reviewed the data on 1559 patients who were treated with radical prostatectomy (RP) at our institution between 2005 and 2013 and classified them according to National Comprehensive Cancer Network (NCCN) risk groups. For our analyses, intermediate-risk PCa was designated as unfavourable intermediate-risk PCa if it met at least one of the following two criteria: biopsy Gleason score 4 + 3 and/or presence of ≥ 2 intermediate-risk criteria. All other men with intermediate-risk PCa were designated as having favourable intermediate-risk disease. Postoperative outcomes, including biochemical recurrence (BCR)-free survival, were calculated and compared using the log-rank test and Cox proportional hazards model. RESULTS: In multivariable analysis, biopsy Gleason score 4 + 3 and multiple (≥ 2) intermediate-risk criteria were observed to be independent predictors of BCR risk among men in the intermediate-risk group undergoing RP. The favourable intermediate-risk group had a significantly higher 5-year BCR-free survival compared with the unfavourable intermediate-risk group (87.5 vs 66.5%; P < 0.001). The unfavourable intermediate-risk group had significantly higher 5-year BCR-free survival than the high-risk group (66.5 vs 47.9%; P < 0.001) while the favourable intermediate-risk group had significantly lower 5-year BCR-free survival than the low-risk group (87.5 vs 93.5%; P = 0.002). CONCLUSIONS: A marked heterogeneity exists in the biochemical outcomes of contemporary patients with intermediate-risk PCa who undergo definitive RP. According to biopsy Gleason score and number of intermediate-risk criteria present, the intermediate-risk group should be sub-divided into those with favourable and unfavourable intermediate-risk disease.

Occurrence of Legacy and New Persistent Organic Pollutants in Avian Tissues from King George Island, Antarctica.

Legacy and new persistent organic pollutants (POPs), including polychlorinated naphthalenes (PCNs), Dechlorane Plus (DPs) and related compounds (Dechloranes), hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), were analyzed in avian tissue samples from King George Island, Antarctica. The avian species consisted of the Gentoo penguin (Pygoscelis papua), the Adelie penguin (Pygoscelis adeliae), the South polar skua (Stercorarius maccormicki), and the Brown skua (Stercorarius antarcticus). HBCDs were detected in all samples and ranged from 1.67-713 pg/g-lipid. In the penguin samples, the concentrations of PCNs ranged from 0.69-2.07 ng/g-lipid, whereas those in the skua samples ranged from 7.41-175 ng/g-lipid. The levels of Dechloranes ranged from 0.60-1.30 ng/g-lipid in the penguin samples and from 6.57-47.4 ng/g-lipid in the skua samples. The concentrations and congener distributions of OCPs and PCBs were similar to the results of previous reports. The three new POPs were detected in all samples, and this study was one of the first reports on the occurrence of these pollutants in the Antarctic biota. Because Antarctica is one of the most pristine places on Earth, the detection of new POPs in the Antarctic birds, especially penguins, is direct evidence of the long-range transport of pollutants. Furthermore, the concentration ratios of the penguin to the skua samples (BMFs-p) were greater than 1 in most legacy and new POPs, and the BMFs-p values of the new POPs were comparable to those of some OCPs, suggesting a possibility of biomagnification. Despite the small sample size, the results of this study identified POP contamination of the Antarctic avian species and long-range transport and biomagnification of HBCDs, Dechloranes, and PCNs.

Targeted therapy after complete resection of metastatic lesions in metastatic renal cell carcinoma.

OBJECTIVES: To evaluate the efficacy of targeted therapy after complete resection of metastatic lesions in patients with metastatic renal cell carcinoma. METHODS: We retrospectively reviewed the medical records of 53 patients with metastatic renal cell carcinoma who underwent complete surgical resection of metastatic lesions between January 2006 and December 2012. Immediate postoperative targeted therapy was given to a subgroup of patients. Progression-free survival and cancer-specific survival were assessed. RESULTS: All patients underwent curative surgery for a primary tumor. A total of 13 patients (24.5%) had metastatic disease at initial diagnosis, and 49 (92.5%) had single-organ involvement at the time of first metastasis. None of the patients met the poor-risk criteria. Of the 19 patients who received immediate postoperative targeted therapy, five (26.3%) experienced relapse. Of the 34 patients who did not receive immediate postoperative targeted therapy, 27 (79.4%) experienced disease recurrence. Targeted therapy was restarted in 30 patients (93.8%) after relapse with excellent disease control rates (complete response: 3.3%, partial response: 36.7%, stable disease: 46.7%). Immediate postoperative targeted therapy was associated with better median progression-free survival (not reached vs 20.0 months; P = 0.017), but not better cancer-specific survival. CONCLUSIONS: Postoperative targeted therapy after complete metastasectomy seems to be associated with better progression-free survival in patients with metastatic renal cell carcinoma, but not with cancer-specific survival.

Ubiquitin ligase Nedd4 promotes alpha-synuclein degradation by the endosomal-lysosomal pathway.

α-Synuclein is an abundant brain protein that binds to lipid membranes and is involved in the recycling of presynaptic vesicles. In Parkinson disease, α-synuclein accumulates in intraneuronal inclusions often containing ubiquitin chains. Here we show that the ubiquitin ligase Nedd4, which functions in the endosomal-lysosomal pathway, robustly ubiquitinates α-synuclein, unlike ligases previously implicated in its degradation. Purified Nedd4 recognizes the carboxyl terminus of α-synuclein (residues 120-133) and attaches K63-linked ubiquitin chains. In human cells, Nedd4 overexpression enhances α-synuclein ubiquitination and clearance by a lysosomal process requiring components of the endosomal-sorting complex required for transport. Conversely, Nedd4 down-regulation increases α-synuclein content. In yeast, disruption of the Nedd4 ortholog Rsp5p decreases α-synuclein degradation and enhances inclusion formation and α-synuclein toxicity. In human brains, Nedd4 is present in pigmented neurons and is expressed especially strongly in neurons containing Lewy bodies. Thus, ubiquitination by Nedd4 targets α-synuclein to the endosomal-lysosomal pathway and, by reducing α-synuclein content, may help protect against the pathogenesis of Parkinson disease and other α-synucleinopathies.

Morphometric analysis of the proximal ulna using three-dimensional computed tomography and computer-aided design: varus, dorsal, and torsion angulation.

PURPOSE: The proximal ulna, particularly the course of the posterior border, has a complex three-dimensional (3D) morphology which has been highlighted recently due to its clinical relevance in relation to surgical treatments. 3D computed tomography (CT) reconstruction and computer-aided design (CAD) based software can help to visualize the complex anatomy and thus aid the investigation of the more detailed morphology of the proximal ulna. METHODS: In our current study, 3D CT reconstruction images of 20 cadavers were imported into the 3D CAD program. Three morphologic angle parameters of the proximal ulna were measured including the dorsal, varus and torsion angulation. The torsion angulation was measured using the flat spot of olecranon dorsal aspect. We measured the total length of the ulna and the distance between the olecranon tip and the apex of dorsal and varus angulation. Furthermore, the thickness of olecranon was also measured for all the specimens. RESULTS: The results showed that the mean dorsal, varus, and torsion angulation was 4.3° (range 2.6°-5.9°), 12.1° (range 7.9°-17.6°), and 22.5° (range 16.6°-30.5°), respectively. The average length ratio of the dorsal and varus angulation apex to the total ulnar length was 26.4 % (range 19.8-30.7 %) and 32.7 % (range 27.5-37.5 %), respectively. The average of olecranon thickness at the proximal tip, mid-olecranon fossa, and at coronoid tip level was 17.8 mm (range 14.1-22.8 mm), 19.7 mm (range 15.8-23.1 mm), and 35.1 mm (range 27.9-41.8 mm), respectively. CONCLUSION: In conclusion, variations in the proximal ulna have to be considered when anatomically contoured dorsal plates are applied. Knowledge of the 3D morphologic anatomy of the proximal ulna would provide important information on fracture reductions, and the design of a precontoured dorsal plate or a prosthetic ulnar stem.

Assessment of exposure to sulfuric acid in workers using cleaning equipment operated with lead-acid batteries.

Sulfuric acid, a constituent of lead-acid batteries, is an extremely hazardous substance, necessitating utmost caution. Unfortunately, many workers that utilize battery-operated equipment remain unaware of the potential exposure. This study aims to evaluate the potential exposure to sulfuric acid among workers employed by small companies associated with the operation of floor cleaning equipment powered by lead-acid batteries. Only cleaning equipment (hand-push and ride-on types) that required supplementation of lead-acid batteries with distilled water were targeted. Exposure measurement and analysis were performed according to the guidelines of NIOSH and including personal sampling and stationary sampling on the equipment. Exposure measurements indicated that workers were exposed to sulfuric acid. Additionally, the concentration level was slightly elevated in the stationary samples compared to personal samples. This study affirms that workers can experience exposure to sulfuric acid, even in the absence of direct handling of the substance. Consequently, there is a need to recognize and mitigate the potential risks.

Integrative Multi-omics Analysis Reveals Different Metabolic Phenotypes Based on Molecular Characteristics in Thyroid Cancer.

PURPOSE: Thyroid cancer metabolic characteristics vary depending on the molecular subtype determined by mutational status. We aimed to investigate the molecular subtype-specific metabolic characteristics of thyroid cancers. EXPERIMENTAL DESIGN: An integrative multi-omics analysis was conducted, incorporating transcriptomics, metabolomics, and proteomics data obtained from human tissues representing distinct molecular characteristics of thyroid cancers: BRAF-like (papillary thyroid cancer with BRAFV600E mutation; PTC-B), RAS-like (follicular thyroid cancer with RAS mutation; FTC-R), and ATC-like (anaplastic thyroid cancer with BRAFV600E or RAS mutation; ATC-B or ATC-R). To validate our findings, we employed tissue microarray of human thyroid cancer tissues and performed in vitro analyses of cancer cell phenotypes and metabolomic assays after inducing genetic knockdown. RESULTS: Metabolic properties differed between differentiated thyroid cancers of PTC-B and FTC-R, but were similar in dedifferentiated thyroid cancers of ATC-B/R, regardless of their mutational status. Tricarboxylic acid (TCA) intermediates and branched-chain amino acids (BCAA) were enriched with the activation of TCA cycle only in FTC-R, whereas one-carbon metabolism and pyrimidine metabolism increased in both PTC-B and FTC-R and to a great extent in ATC-B/R. However, the protein expression levels of the BCAA transporter (SLC7A5) and a key enzyme in one-carbon metabolism (SHMT2) increased in all thyroid cancers and were particularly high in ATC-B/R. Knockdown of SLC7A5 or SHMT2 inhibited the migration and proliferation of thyroid cancer cell lines differently, depending on the mutational status. CONCLUSIONS: These findings define the metabolic properties of each molecular subtype of thyroid cancers and identify metabolic vulnerabilities, providing a rationale for therapies targeting its altered metabolic pathways in advanced thyroid cancer.

Defect Passivation of 2D Semiconductors by Fixating Chemisorbed Oxygen Molecules via h-BN Encapsulations.

Hexagonal boron nitride (h-BN) is a key ingredient for various 2D van der Waals heterostructure devices, but the exact role of h-BN encapsulation in relation to the internal defects of 2D semiconductors remains unclear. Here, it is reported that h-BN encapsulation greatly removes the defect-related gap states by stabilizing the chemisorbed oxygen molecules onto the defects of monolayer WS2 crystals. Electron energy loss spectroscopy (EELS) combined with theoretical analysis clearly confirms that the oxygen molecules are chemisorbed onto the defects of WS2 crystals and are fixated by h-BN encapsulation, with excluding a possibility of oxygen molecules trapped in bubbles or wrinkles formed at the interface between WS2 and h-BN. Optical spectroscopic studies show that h-BN encapsulation prevents the desorption of oxygen molecules over various excitation and ambient conditions, resulting in a greatly lowered and stabilized free electron density in monolayer WS2 crystals. This suppresses the exciton annihilation processes by two orders of magnitude compared to that of bare WS2. Furthermore, the valley polarization becomes robust against the various excitation and ambient conditions in the h-BN encapsulated WS2 crystals.

Design and assessment of a microfluidic network system for oxygen transport in engineered tissue.

Oxygen and nutrients cannot be delivered to cells residing in the interior of large-volume scaffolds via diffusion alone. Several efforts have been made to meet the metabolic needs of cells in a scaffold by constructing mass transport channels, particularly in the form of bifurcated networks. In contrast to progress in fabrication technologies, however, an approach to designing an optimal network based on experimental evaluation has not been actively reported. The main objective of this study was to establish a procedure for designing an effective microfluidic network system for a cell-seeded scaffold and to develop an experimental model to evaluate the design. We proposed a process to design a microfluidic network by combining an oxygen transport simulation with biomimetic principles governing biological vascular trees. The simulation was performed with the effective diffusion coefficient (D(e,s)), which was experimentally measured in our previous study. Porous scaffolds containing an embedded microfluidic network were fabricated using the lost mold shape-forming process and salt leaching method. The reliability of the procedure was demonstrated by experiments using the scaffolds. This approach established a practical basis for designing an effective microfluidic network in a cell-seeded scaffold.