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Antimicrobial peptides (AMPs) are a crucial component of the natural defense system that the host employs to protect itself against invading pathogens. PMAP-23, a cathelicidin-derived AMP, has potent and broad spectrum antimicrobial activity. Our earlier studies led us to hypothesize that PMAP-23 adopts a dynamic helix-hinge-helix structure, initially attaching to membrane surfaces through the N-helix and subsequently inserting the C-helix into the lipid bilayer. Here, we rationally designed PMAP-NC with increased amphipathicity and hydrophobicity in the N- and C-helix, respectively, based on the hypothesis of the interaction of PMAP-23 with membranes. Compared to the parental PMAP-23, PMAP-NC showed 2–8 fold improved bactericidal activity against both gram-positive and gram-negative strains with fast killing kinetics. Fluorescence studies demonstrated that PMAP-NC largely disrupted membrane integrity, indicating that efficiency and kinetics of bacterial killing are associated with the membrane permeabilization. Interestingly, PMAP-NC exhibited much better anticancer activity against tumor cells than PMAP-23 but displayed low hemolytic activity against human erythrocytes. Collectively, our findings suggest that PMAP-NC, with the structural arrangement of an amphipathic helix–hinge–hydrophobic helix that plays a critical role in rapid and efficient membrane permeabilization, can be an attractive candidate for novel antimicrobial and/or anticancer drugs.

Thermochemical heat storage is a promising energy storage method and has received much attention in recent years. To improve the design and application of such systems, a better understanding of the characteristics of thermochemical heat storage is required. In this study, we analyze the heat release characteristics of thermochemical heat storage considering various operating parameters, such as charging temperature, humidity, and material. Three different thermochemical materials are considered herein, namely, zeolite 13X, zeolite 5A, and silica gel. The temperature profile at the inlet and outlet of the storage chamber, and that inside the chamber packed with thermochemical material, were measured. The pressure drop across the chamber was measured as well. The results indicate that the heat release characteristics change with position and time. Furthermore, the temporal curves of released heat are significantly affected by charging temperature and humidity. Zeolite 13X rapidly released a large amount of heat within a short period of time, whereas silica gel gradually released a small amount of heat, over a longer duration of time. The pressure drop across the chamber was found to vary with the bead size of the thermochemical material. Thus, the operating parameters including charging temperature, humidity, and material, have a significant effect on the characteristics of heat release. The data obtained herein can serve as a reference for the design of thermochemical storage systems.

Tokenization is a significant primary step for the training of the Pre-trained Language Model (PLM), which alleviates the challenging Out-of-Vocabulary problem in the area of Natural Language Processing. As tokenization strategies can change linguistic understanding, it is essential to consider the composition of input features based on the characteristics of the language for model performance. This study answers the question of “Which tokenization strategy enhances the characteristics of the Korean language for the Named Entity Recognition (NER) task based on a language model?” focusing on tokenization, which significantly affects the quality of input features. We present two significant challenges for the NER task with the agglutinative characteristics in the Korean language. Next, we quantitatively and qualitatively analyze the coping process of each tokenization strategy for these challenges. By adopting various linguistic segmentation such as morpheme, syllable and subcharacter, we demonstrate the effectiveness and prove the performance between PLMs based on each tokenization strategy. We validate that the most consistent strategy for the challenges of the Korean language is a syllable based on Sentencepiece.

Reasoning, a trait of cognitive intelligence, is regarded as a crucial ability that distinguishes humans from other species. However, neural networks now pose a challenge to this human ability. Text-to-image synthesis is a class of vision and linguistics, wherein the goal is to learn multimodal representations between the image and text features. Hence, it requires a high-level reasoning ability that understands the relationships between objects in the given text and generates high-quality images based on the understanding. Text-to-image translation can be termed as the visual thinking of neural networks. In this study, our model infers the complicated relationships between objects in the given text and generates the final image by leveraging the previous history. We define diverse novel adversarial loss functions and finally demonstrate the best one that elevates the reasoning ability of the text-to-image synthesis. Remarkably, most of our models possess their own reasoning ability. Quantitative and qualitative comparisons with several methods demonstrate the superiority of our approach.

With the regular increase in global solid waste, landfilling is intensively used for waste disposal. However, landfill gas (LFG) produced as a byproduct during waste decomposition in the landfills is a serious problem since it leads to damage to the eco-systems. Accordingly, it has been highlighted to convert LFG into other value-added chemicals. In this study, LFG utilization was studied in terms of conversion into methanol (MeOH) by considering different scenarios of LFG utilization. Techno-economic analysis and environmental assessment were performed to identify the economic feasibility and environmental impact of each case. From the economic analysis, bio-MeOH production costs of 879.16, 724.52, and 1,130.74 $ ton

Cross-linking technology has been considered as one of the effective strategies for improving the physicochemical stability of proton-exchange membranes (PEMs) for fuel cell applications. However, ...

An optimized acid hydrolysis method was developed to yield carboxylic acid-functionalized PIM-1 (PIM-COOH) with >89% conversion in 48 h using a postpolymerization reaction of PIM-1. Physical charac...

Nanotube membranes could show significantly enhanced permeance and selectivity for gas separations. Up until now, studies have primarily focused on applying carbon nanotubes to membranes to achieve...

The effect of repair patches with different geometric shapes on bonding strength was investigated. Four shapes of patches were considered: rectangular patch (RP), triangular patch (TP), inv...

End-group cross-linked sulfonated poly(arylene ether sulfone) (SPAES) membranes were prepared using thiol capped SPAES (SH-SPAES) with different amounts of vinyl polysulfone (VPSf) as a polymeric cross-linker. The cross-linked membranes showed remarkably improved physicochemical stabilities compared to the corresponding linear SPAES membrane. Although the proton conductivity of the SPAES membrane composed of SPAES with the degree of sulfonation (DS) as 70 mol% could not be measured due to its low physical stability under the measurement condition, those of the cross-linked membranes were repeatedly evaluated due to the enhanced stability through the formation of cross-linked structures. The obtained proton conductivity values from cross-linked membranes are larger than those of the linear SPAES membrane which composed of SPAES with DS of 50 mol% having the ion exchange capacity (IEC) similar to that of the cross-linked membranes, especially at relative low humidity conditions. Furthermore, the fuel cell performance of the membrane electrode assembly (MEA) prepared with the cross-linked membrane, showing the optimized physicochemical stabilities and proton conductivity exhibited a maximum power density of 692 mW cm−2, which was larger than that with Nafion 212 (603 mW cm−2) at 80 °C under fully humidified H2/Air condition.

Sulfonated poly(arylene ether sulfone) (SPAES) composite membranes were prepared using graphene oxide (GO) and sulfonated poly(arylene thioether sulfone)-grafted graphene oxide (SATS-GO) as fillers for proton exchange membrane fuel cell (PEMFC) applications. When GO and SATS-GO were mixed with SPAES to form the composite membranes, dimensional stability, chemical stability, and mechanical strength were improved. The composite membranes containing SATS-GO especially showed higher proton conductivity than the pristine SPAES and the composite membrane containing GO because of highly sulfonated polymer (SATS) introduced on GO surface. Furthermore, the sulfonic acid groups in SATS-GO can increase the compatibility between the filler and matrix polymer.

To reduce CO2 emissions and address climate change concerns, most futuristic studies investigating 100% renewable energy sources and subsequent power-to-gas/fuel/liquid/X technological developments have been based on hydrogen (H2). The long-term storage and transportation of H2 over long distances restrict its feasibility as an energy vector, mainly due to its low energy density. Liquefaction is a promising approach for overcoming these issues. However, it requires a large amount of energy, and if H2 itself is used to provide this energy, then 25% to 35% of the initial quantity of H2 is consumed. The existing H2 liquefaction plants have specific energy consumption values in the range of 10–12 kWh / kg LH 2 and exergy efficiencies in the range of 20%–30% with complicated configurations. Therefore, a thermodynamically efficient and compact design is required to facilitate a roadmap to H2 economy. This paper proposes a simple, energy-efficient, and cost-effective process for H2 liquefaction. Three refrigeration cycles with optimal mixed-refrigerant compositions are used, which makes the proposed process energy-efficient. Additionally, two-stage ortho-to-para conversion makes the process compact. The proposed process is unique in terms of its configuration and mixed-refrigerant combination. The modified coordinate descent approach was adopted to identify the optimal design variables for the proposed H2 liquefaction process. The proposed process consumes an energy of 6.45 kWh / kg LH 2 , which is 36.5% and 16.1% lower than that consumed by the base design of the proposed process and a published base case, respectively. Additionally, the exergy efficiency of the proposed process is 47.2%. This study will help process engineers achieve a sustainable green economy by improving the competitiveness of H2 storage and transportation over long distances.

Porous nanosheets made of effectively aligned zeolitic imidazolate framework-8 (ZIF-8), dubbed ZPGO, with an exceptionally high surface area (2170 m2 g−1) were demonstrated. This composite was prepared by growing ZIF-8s on highly porous graphene oxide (PGO) and the mixed matrix membrane with such a nanofiller showed drastically improved size-selective CO2 transport even at very low filler concentration (0.02 wt%) especially under mixed gas conditions where both selectivity (CO2/N2 ∼57) and CO2 permeability (∼163 barrer) were significantly enhanced. In addition to this, ZPGO effectively suppressed CO2-plasticization, which indicates great potential in real operations. This new concept of nanofillers is expected to maximize the filler effect in other fields benefitting from a high surface area as well.

We investigated the effect of graphene oxide (GO) and sulfonated polytriazole grafted graphene oxide (SPTA-GO) on sulfonated poly(arylene ether sulfone) (SPAES) based polymer electrolytes for application in proton exchange membrane fuel cells. GO was fabricated by the chemical oxidation of graphite and SPTA-GO was prepared via the click reaction using copper (Ⅰ) catalyzed azide-alkyne 1,3-dipolar cycloaddition between ethynyl-terminated sulfonated polytriazole (E-SPTA) and azide functionalized GO (N3-GO). All the SPAES based composite membranes with GO and SPTA-GO revealed better physical/chemical stabilities and mechanical strength than the pristine SPAES membrane, while noticeable improvement of proton conductivity was only observed in the SPAES composite membrane with SPTA-GO since the SPTA moiety attached on GO has both sulfonic acid and triazole groups that can introduce the additional proton conducting channels into the SPAES matrix. The maximum power density of the membrane electrode assembly employing the SPAES composite membrane with SPTA-GO reached up to 1.58 W cm−2 at 80 °C and 100% RH condition, which is larger than that employing commercial Nafion 212 (1.33 W cm−2).

Soft and still responsive Transparent touch screens, from large-panel interactive information maps to advanced cell phones, have become a part of daily life. However, such devices all use hard materials. Kim et al. have developed a soft touch panel based on polyacrylamide hydrogels (cross-linked polymers swollen with water) that are highly transparent and contain trapped LiCl to enhance conductivity. The hydrogels are soft and can be stretched extensively while still maintaining touch sensitivity. Science , this issue p. 682

Background:There are no known studies that have investigated the effect on delaminated rotator cuff tears of bursal layer–only repair when full-thickness repair would put the articular layer under tension, compared with all-layers repair when full-thickness repair is feasible.Hypothesis:Better outcomes will be seen in the bursal layer–only repair, as the articular layer would be under tension when repaired onto its footprint during the all-layers repair.Study Design:Cohort study; Level of evidence 3.Methods:This study included 112 patients who underwent arthroscopic rotator cuff repair for posteriorly delaminated tears of either all layers (group A) or the bursal layer alone (group B). If the articular layer was able to be reduced onto its footprint, the patient was assigned to group A; if such reduction was not possible or was only marginally possible under significant tension, the patient was assigned to group B. Pain scored on a visual analog scale (VAS) was assessed, as were subjective shoulder value (SSV), University of California, Los Angeles (UCLA) shoulder score, American Shoulder and Elbow Surgeons (ASES) score, and shoulder active range of motion (ROM). Postoperative magnetic resonance arthrography (MRA) or computed tomographic arthrography (CTA) was undertaken 6 months postoperatively for structural integrity assessment.Results:After 2 years, the VAS pain score (group A, from 6.5 to 1.2; group B, from 6.4 to 1.2), SSV (group A, from 38.3 to 89.4; group B, from 38.0 to 90.1), ASES score (group A, from 36.4 to 90.4; group B, from 38.0 to 90.8), UCLA shoulder score (group A, from 15.3 to 30.7; group B, from 15.0 to 31.3), and ROM improved significantly in both groups compared with preoperative values ( P < .001). However, none of these values differed significantly between groups. On follow-up MRA or CTA images, there was no significant difference in the retear rate between group A (28%; 16/57) and group B (24%; 11/45).Conclusion:The all-layers repair did not produce better clinical outcomes or structural integrity than the bursal layer–only repair. The study findings indicate that if repair of the articular layer is possible only under significant tension or is not reparable, rather than all-layers repair by force, bursal-layer repair without incorporating the articular layer may produce comparable clinical outcomes and structural integrity in the delaminated rotator cuff tear.

Cross-linked sulfonated poly (ether ether ketone) (C-SPEEK) membranes for direct methanol fuel cell (DMFC) applications are prepared using SPEEK with chloromethyl side groups (SPEEK-Cl) and poly (2,5-benzimidazole)-grafted graphene oxide (ABPBI-GO) as a cross-linker. The C-SPEEK membranes exhibit remarkably improved physicochemical stability and decreased methanol permeability compared to a pristine SPEEK membrane and SPEEK composite membranes composed of SPEEK and GO based fillers such as GO and ABPBI-GO. Although the proton conductivities of the C-SPEEK membranes are smaller than those of the pristine SPEEK and SPEEK composite (SPEEK/GO and SPEEK/ABPBI-GO) membranes, cell performances of the membrane electrode assemblies (MEAs) using the C-SPEEK membranes with the optimized contents of ABPBI-GO (cross-linker) are better than those using the pristine SPEEK and SPEEK composite membranes due to the well dispersion of ABPBI-GO by forming an effectively covalent bonded network structure with SPEEK-Cl resulting in the decreased methanol permeability. The maximum power density of the MEA with the C-SPEEK membrane (86 mW cm−2) is larger than those with the pristine SPEEK (71 mW cm−2) and SPEEK composite (69 mW cm−2) membranes at 60 °C with 1.5 M methanol/air feed condition.

Sophia-Hubo is developed to perform walking mobility on the Sophia robot, which is a human-like robot developed by Hanson Robotics Ltd. The robot has achieved walking motion to attach Hubo's lower body. Also, it needs arm motions to interact with people such as a handshake and gestures. To handshake with a person, we use inverse kinematics (IK) of Sophia-Hubo's right arm for stretching the arm to the person and torque control for handshaking. We use Levenberg-Marquardt method with Robust Damping to find a solution of the IK, and torque control of Dynamixel on shoulder pitch and elbow joint. The torque control input is calculated with the measured joint angular velocity. For making joints moving smoothly, we apply a 5th polynomial function trajectory. Through recursively adding the 5th polynomial trajectory to the end of the previous trajectory, we can make gestures.

Smart Work is a way of working independent of time and space restrictions with the help of ICT. For past years, Korea has been promoting Smart Work to boost ICT industry, to overcome low birth rate and population ageing, and to implement Smart Korea. Three elements of Smart Work include people, technology and space. A lot of research has been performed on people and technology for Smart Work. But it is hard to find research on space. In this paper, some representative smart work centers(SWCs) in Korea were selected and analyzed from the perspective of spatial design including general characteristics, personal spaces, group spaces, and support spaces. From this research, it is observed that current SWCs in Korea are good in providing personal work spaces and simple group meeting rooms as well as ICT environments. However, they lack of openness to the public and group spaces to encourage informal communications. It is also observed that personal space plans need to be multi-functional, and that novel supporting spaces are required to improve quality of life and creativity of workers.

This paper presents the initial work toward deep space robotic applications. Humanoid robots as astronauts can experience gravity differences, hazardous environmental conditions, extreme latency communications, and lack of energy sources while on deep space missions. Such constraints provide a challenge in the development of software, hardware, and experiments for space humanoid robots. This paper demonstrates the preliminary work for deep space robotics through the two qualification tasks specified by NASA's Space Robotics Challenge. The tasks are implemented in both the SRC simulator using IHMC ROS APIs, and with a physical humanoid robot, DRC-Hubo. The main objective is to testify the fundamental vision capability and maneuverability for deep space missions. This paper serves as a reference for future research in the field of deep space robotics.

The lift-and-carry of non-rigid objects is challenging for both people and bipedal robots. Examples include lifting and carrying jugs, jerry cans or bags that are respectively filled with water, gasoline or sand. Carrying such objects often makes it difficult to walk due to the shifting center-of-mass. As such, tripping and falling are risks. Such lift-and-carry is a common material handling task. For bipedal robots to be deployed in unstructured or cluttered environments like factory floors, agricultural fields or disaster sites, robust methods for lift-and-carry are needed. This paper motivates, highlights, and provides experimental results to underscore the value and challenges of the bipedal lift-and-carry of non-rigid objects.

Recently high-rise housing has become prosperous in Korea as a type of multi-use building, having good conditions of traffic, site exiting, facilities etc. In terms of a residential environment, hi...

Following the first shock wave generation and the successive single bubble expansion after the breakdown by the Nd:YAG laser pulse with 35 mJ and 10 ns in distilled water, the strong secondary shock wave is generated at the instant of the bubble collapse. The single bubble expands up to 0.59 mm in radius, and then closes up by the pressure difference between the ambient liquid pressure at 102 kPa and the vapor pressure inside the bubble at 2 kPa. The maximum pressure up to 3 GPa is attained without the strong rebounding surface motion at about 93 μs after the laser shedding. We present time-resolved velocity measurements for estimating the extreme peak pressures of the first and second shock waves with the Rankine–Hugoniot analysis.

Impingement of a high power laser pulse (above 109 W/cm2) on a metal foil causes ablation, which is characterized by a rapid expulsion of matter and initiation of a strong shock wave inside the solid metal. The shock propagates through the foil and reverberates on the rear side causing instant deformation of the foil, whose surface is treated with micro particles prior to ablation. Based on this principle of micro particle ejection, we develop a new biolistic gun with improved controllability, stability, efficiency of our previous system, and perform characterization of the penetration shapes at varying confinements and energy levels. The confinement media include BK7 glass, water, and succulent jelly (ultrasound gel). Biological tissue was replicated by a gelatin-water solution at a 3% weight ratio. Present data show that confinement effect results in a conspicuous enhancement of penetration reached by 5 μm cobalt micro particles. Also, there exists an optimal thickness at each energy level when using liquid confinement for enhanced particle delivery.

This article first presented direct applicability of Fenton's oxidation to high-strength wastewater, especially when efficiency of biological treatment for high-strength wastewater is insufficient. Fenton's oxidation was applied both to biologically pretreated molasses wastewater (BMW) and untreated molasses wastewater (MW), and the removal of color and chemical oxygen demand using chromate (CODcr) were compared between the two wastewaters. The optimum reaction time was 20 min for both BMW and MW. Neither the different dosages of Fenton's reagents nor the initial pH affected the removal ratios of CODcr and color from either BMW or MW. The maximum removal ratios of CODcr and color were approximately 90 and 97% for BMW and 88 and 98% for MW, respectively. Although these ratios are similar, the optimum H2O2 dose (g L−1)/initial CODcr (g L−1) ratio and the optimum H2O2/Fe2+ molar ratio for BMW treatment were larger than those for MW treatment. This indicates that direct Fenton treatment of MW uses le...

Ablation occurs at irradiance beyond 10 9 W/cm 2 with nanosecond and short laser pulses focused onto any materials. Phenomenologically, the surface temperature is instantaneously heated past its vaporization temperature. Before the surface layer is able to vaporize, underlying material will reach its vaporization temperature. Temperature and pressure of the underlying material are raised beyond their critical values, causing the surface to explode. The pressure over the irradiated surface from the recoil of vaporized material can be as high as 10 5 MPa. The interaction of high power nanosecond laser with a thin metal in air has been investigated. The nanosecond pulse laser beam in atmosphere generates intensive explosions of the materials. The explosive ejection of materials make the surrounding gas compressed, which form a shock wave that travels at several thousand meters per second. To understand the laser ablation mechanism including the heating and ionization of the metal after lasing, the temporal evolution of shock waves is captured on an ICCD camera through laser flash shadowgraphy. The expansion of shock wave in atmosphere was found to agree with the Sedov’s self-similar spherical blast wave solution.기호설명R : 충격파 반지름 E : 레이저 에너지

In batch mesophilic anaerobic digestion of a mixture of iron-rich sludge collected from Fenton treatment of molasses wastewater (MWW) and thickened sewage sludge from a municipal wastewater treatment plant, the methane content in the gas from the mixture was significantly higher than that from thickened sewage sludge only. When minerals in iron-rich sludge obtained by incineration were fed to thickened sewage sludge in semi-continuous experiments, the methane content obtained by digestion of thickened sewage sludge only increased approximately from 53% to 64%. These results suggest that iron-rich sludge can enhance methane production for thickened sewage sludge.

Transdermal and topical drug delivery with minimal tissue damage has been an area of vigorous research for years. Our research team has initiated the development of an effective method for delivering drug particles across the skin (transdermal) for systemic circulation, and to localized (topical) areas. The device consists of a laser ablation based micro-particle acceleration system that can be integrated with endoscopic surgical techniques. We have successfully delivered 3㎛ size cobalt particles into gelatin models that represent soft tissue with remarkable penetration depth.

The Fenton method was applied to the removal of chemical oxygen demand using chromate (CODcr) and color from high-strength livestock wastewater in which the initial CODcr was 5000-5700 mg/L. The optimum ratio of H2O2 (mg/L) to the initial CODcr was 1.05 and the optimum molar ratio of H2O2/Fe2+ was 2. The optimum initial pH and the optimum reaction time were 3.5-4 and 30 min, respectively. Under optimal conditions, the removal ratios of CODcr and color of the supernatant after static precipitation of the produced sludge were 88 and 95.4%, respectively. Addition of Fenton's reagents in several aliquots did not affect the efficiencies of CODcr and color removal.