Publications by authors named "Sangjae Kim"

Metal-organic frameworks (MOFs) are porous crystalline materials with a metal ion coordinated to a ligand molecule. Recently, MOFs are being explored extensively for energy harvesting triboelectrification. However, the majority of MOFs are brittle and hard to grow, thus leading to poor device stability and flexibility.

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Article Synopsis
  • Nickel foam (NF) was tested as a method for capturing polyethylene (PE) particles from water, showing a baseline efficiency of 69.5% when used alone.
  • To improve this, NF was coated with polydimethylsiloxane (PDMS), boosting efficiency to 97.6% due to enhanced hydrophobic properties.
  • The study utilized Raman spectroscopy with a wide area illumination method for accurate quantification of captured particles, demonstrating excellent capturing efficiencies for other plastics (PP, PS, PET) as well, suggesting a potential tool for detecting microplastics in water.
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An effective and rapid Raman measurement scheme to determine FeO concentration in sintered ores was explored. Because sintered ores are brownish-black materials that easily absorb laser photons, accurate quantitative analysis requires obtaining an FeO peak with a high signal-to-ratio by reducing the possibility of local sample heating and degradation. For this purpose, a wide area coverage (WAC) Raman scheme with a laser-illumination diameter of 1 mm was adopted to decrease the laser power per area (LP/A) on each sample.

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An advanced energy autonomous system that simultaneously harnesses and stores energy on the same platform offers exciting opportunities for the near-future self-powered miniature electronics. However, achieving optimal synchronization between the power output of an energy harvester and the storage unit or integrating it seamlessly with real-time microelectronics to build a highly efficient energy autonomous system remains challenging. Herein, a unique bimetallic layered double hydroxide (LDH) based tribo-positive layer is introduced for a high-voltage sliding triboelectric nanogenerator (S-TENG) with an output voltage of ≈1485 V and power output of 250 µW, respectively.

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Electrochemical energy systems mark a pivotal advancement in the energy sector, delivering substantial improvements over conventional systems. Yet, a major challenge remains the deficiency in storage technology to effectively retain the energy produced. Amongst these are batteries and supercapacitors, renowned for their versatility and efficiency, which depend heavily on the quality of their electrode materials.

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Purpose: To investigate the effectiveness of bursal acromial resurfacing (acromiograft) on acromiohumeral distance, subacromial contact area, and pressure in a cadaveric model of massive rotator cuff tear.

Methods: Eight fresh-frozen cadaveric shoulders were tested using a customized shoulder testing system. Humeral head translation, subacromial contact pressure, and the subacromial contact area were evaluated across 4 conditions: (1) intact shoulder; (2) simulated massive rotator cuff tear, (3) 3-mm acromiograft condition, and (4) 6-mm acromiograft condition.

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GV1001, an anticancer vaccine, exhibits other biological functions, including anti-inflammatory and antioxidant activity. It also suppresses the development of ligature-induced periodontitis in mice. (), a major human oral bacterium implicated in the development of periodontitis, is associated with various systemic disorders, such as atherosclerosis and Alzheimer's disease (AD).

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Engineering the intermetallic nanostructures as an effective bifunctional electrocatalyst for hydrogen and oxygen evolution reactions (HER and OER) is of great interest in green hydrogen production. However, a few non-noble metals act as bifunctional electrocatalysts, exhibiting terrific HER and OER processes reported to date. Herein the intermetallic nickel-antimonide (Ni─Sb) dendritic nanostructure via cost-effective electro-co-deposition method is designed and their bifunctional electrocatalytic property toward HER and OER is unrevealed.

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This study reports the use of Keplerate-type {MoFe} polyoxometalate (POMs) nanostructures as a bi-functional-electrocatalyst for HER and OER in an alkaline medium with a lower overpotential (135 mV for HER and 264 mV for OER), and excellent electrochemical stability. The bi-functional catalytic properties of {MoFe} POM are studied using a scanning electrochemical microscope (SECM) via current mapping using substrate generation and tip collection mode. Furthermore, the bipolar nature of the {MoFe} POM nano-electrocatalysts is studied using the electrochemical gating via simultaneous monitoring of the electrochemical (cell) and electrical ({MoFe} POM) signals.

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GV1001, which mimics the activity of human telomerase reverse transcriptase, protects neural cells from amyloid beta (Aβ) toxicity and other stressors through extra-telomeric function, as noted in our prior studies. As per a recent phase II clinical trial, it improves cognitive function in patients with moderate to severe dementia. However, the underlying protective mechanisms remain unclear.

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Background: The utilization of short humeral stems in reverse total shoulder arthroplasty has gained attention in recent times. However, concerns regarding the risk of misalignment during implant insertion are associated with their use.

Methods: Eight fresh-frozen cadaveric shoulders were prepared for dissection and biomechanical testing.

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Purpose: Telomerase activation, a critical step in cancer progression, occurs in approximately 95% of breast cancer cases. Telomerase is an attractive therapeutic target for breast cancer owing to its unique expression pattern. GV1001, a telomerase-derived peptide, is loaded onto human leukocyte antigen (HLA) class II antigen-presenting cells and binds to CD4+ T cell activating immune responses.

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Background: Chitosan biopolymer is an emerging non-toxic and biodegradable plant elicitor or bio-stimulant. Chitosan nanoparticles (CSNPs) have been used for the enhancement of plant growth and development. On the other hand, NO is an important signaling molecule that regulates several aspects of plant physiology under normal and stress conditions.

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Background: The TeloVac study indicated GV1001 did not improve the survival of advanced pancreatic ductal adenocarcinoma (PDAC). However, the cytokine examinations suggested that high serum eotaxin levels may predict responses to GV1001. This Phase III trial assessed the efficacy of GV1001 with gemcitabine/capecitabine for eotaxin-high patients with untreated advanced PDAC.

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GV1001 protects neural cells from amyloid-β (Aβ) toxicity and other stressors in in vitro studies and demonstrates clinically beneficial effects in patients with moderate to severe Alzheimer's disease (AD). Here, we investigated the protective effects and mechanism of action of GV1001 in triple transgenic AD (3xTg-AD) mice. We found that GV1001 improved memory and cognition in middle- and old-aged 3xTg-AD mice.

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GV1001, a 16 amino acid peptide derived from the catalytic segment of human telomerase reverse transcriptase, was developed as an anti-cancer vaccine. Subsequently, it was found to exhibit anti-inflammatory and anti-Alzheimer's disease properties. Periodontitis is a risk factor for a variety of systemic diseases, including atherosclerosis, a process in which chronic systemic and vascular inflammation results in the formation of plaques containing lipids, macrophages, foam cells, and tissue debris on the vascular intima.

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The topochemical preparation of nanostructured materials (NMs) has received significant attention in recent years due to the exceptional electrochemical properties exhibited by the resulting NMs. This work focuses on the preparation of two-dimensional tungsten di-sulfide (WS) nanostructures through the topochemical conversion of tungsten trioxide (WO) nanostructures and also evaluates their potential applications as electrode materials for supercapacitors (SCs). The X-ray diffraction and photoelectron studies conducted in this research reveal the conversion of hexagonal WO into hexagonal WS nanosheets, accompanied by changes in oxidation states.

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Background And Purpose: The efficacy and safety of GV1001 have been demonstrated in patients with moderate-to-severe Alzheimer's disease (AD). In this study, we aimed to further demonstrate the effectiveness of GV1001 using subscales of the Severe Impairment Battery (SIB), which is a validated measure to assess cognitive function in patients with moderate-to-severe AD.

Methods: We performed a analysis of data from a 6 month, multicenter, phase 2, randomized, double-blind, placebo-controlled trial with GV1001 (ClinicalTrials.

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Soft robotics has developed rapidly in recent years as an emergent research topic, offering new avenues for various industrial and biomedical settings. Despite these advancements, its applicability is limited to locomotion and actuation due to the lack of an adequate charge storage system that can support the robot's sensory system in challenging conditions. Herein, an ultra-flexible, lightweight (≈50 milligrams), and wirelessly rechargeable micro-supercapacitor as an onboard power source for miniaturized soft robots, capable of powering a range of sensory is proposed.

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Serious climate changes and energy-related environmental problems are currently critical issues in the world. In order to reduce carbon emissions and save our environment, renewable energy harvesting technologies will serve as a key solution in the near future. Among them, triboelectric nanogenerators (TENGs), which is one of the most promising mechanical energy harvesters by means of contact electrification phenomenon, are explosively developing due to abundant wasting mechanical energy sources and a number of superior advantages in a wide availability and selection of materials, relatively simple device configurations, and low-cost processing.

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Direct-current (DC) triboelectric nanogenerators (TENGs) are increasingly recognized as next-generation power sources for widespread applications. Research has recently focused on developing novel materials as active layers for DC TENGs and device configurations to elucidate the working mechanisms. In this work, we report the use of a carbyne (dehydrohalogenated poly(vinylidene fluoride) (PVDF)) film as a positive-type friction layer for DC TENGs for efficient harvesting of rotary energy.

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Recycling of different manufacturers of spent lithium-ion batteries cathode and anode via a simple regeneration process has an opportunity to fabricate new energy devices. In this study, the different manufacturers of spent LIB cathode pieces were subjected to lixiviation process and found the best-optimized conditions such as tartaric acid concentration (2.5 M), HO concentration (7.

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The two-dimensional 1T-MoS quantum sheets (QSs) continuously seek attention due to their extraordinary energy harnessing and storage properties towards designing an all-in-one self-charging power system (SCPS). Herein, we have utilized the superior dual-functional nature of exfoliated MoS QSs for SCPS via fabricating all-solid-state microsupercapacitors (MSC) as an energy storage device and triboelectric nanogenerator (TENG) with MoS QSs based charge-trapping interfacial layer as the energy harvester. The electrochemical analysis of MoS QSs MSC indicated their superior capacitive properties with a high areal capacitance (4.

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Piezo-photocatalysis is a new concept of utilizing nanohybrids comprising piezoelectric and photocatalytic materials for enhancement in advanced oxidation process under the presence of light and mechanical energy. In this study, we explored the effectiveness of piezo-photocatalysis via examining their catalytic activity towards the degradation of azo dye (Rhodamine-B) and standard pollutant (Phenol) catalyzed by ferroelectric-semiconductor (BaTiO-AgO) nanohybrids. Further, the enhancement in piezo-photocatalysis has been achieved via persulfate activation and the role of free radicals was examined by quenchers.

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