In this study, we investigated the physicochemical and in vitro digestion properties of gelatin (GEL)/low-methoxyl pectin (LMP) synbiotic microgels co-encapsulating Lacticaseibacillus casei (L. ...casei) and pectic oligosaccharides. A single-crosslinked microgel containing L. casei was fabricated via enzymatic crosslinking with transglutaminase. The single-crosslinked microgel was incubated in calcium chloride solution at different concentrations (1%, 2%, and 3%) to produce double-crosslinked microgels. In field emission scanning electron microscopy (FE-SEM) analysis, the double-crosslinked microgels exhibited a more spherical shape with a smoother surface than the single-crosslinked microgel. The crosslinks and possible interactions in the microgels were described using X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy analyses. The encapsulation efficiency of both single- and double-crosslinked microgels was relatively high (95.64%–95.99%). After exposure to simulated gastrointestinal conditions (salivary, gastric, and intestinal phases), the survival rate of L. casei in double-crosslinked microgels (GEL/LMP3) prepared with 3% calcium ions was the highest among all the samples studied. After heat treatment (72 °C for 15 s and 63 °C for 30 min) and 20 days of storage (4 °C and 37 °C), L. casei encapsulated in all microgels, especially double-crosslinked microgels, maintained greater viability than free cells. These results suggest that double-crosslinked GEL/LMP synbiotic microgels, particularly GEL/LMP3, can be used to improve the viability of probiotic cells under gastrointestinal, heating, and storage conditions.
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•Synbiotic microgels exhibit high encapsulation efficiency above 95% for probiotics.•About 88% of L. casei loaded in GEL/LMP3 survived after gastrointestinal digestion.•Double-crosslinked microgels can retain cell viability during heating and storage.•Double-crosslinked microgels proved to be a promising matrix for probiotic loading.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A flexible liquid metal loudspeaker (LML) is demonstrated consisting of a gallium‐based eutectic liquid metal (Galinstan) and basic aqueous electrolyte (NaOH(aq)). The LML is driven by liquid metal ...motion induced by the electrochemically controlled interfacial tension of the Galinstan in NaOH(aq) electrolyte under an applied alternating current (AC) voltage. The fabricated LML produces sound waves in the human audible frequency band with a sound pressure level of ≈40–50 dB at 1 cm from the device and exhibits mechanical stability under bending deformation with a bending radius of 3 mm. Various sounds can be generated with the LML from a single tone to piano notes and human voices. To understand the underlying mechanism of sound generation by the LML, motion analyses, sound measurements, and electrical characterization are conducted at various frequencies. For the first time, this work suggests a new type of liquid metal‐based electrochemically driven sound generator in the field of flexible acoustic devices that can be applied to future wearable electronics.
A flexible liquid metal loudspeaker based on the motion of Galinstan induced by electrochemically controlled interfacial tension under an applied AC voltage is successfully developed for the first time. The fabricated device can form audible sound pressure even in a mechanically deformed state and is applicable to future flexible acoustic devices for wearable electronics.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Considering the various applications of wearable and bio-implantable devices, it is desirable to realize stretchable acoustic devices for body-attached applications such as sensing biological ...signals, hearing aids, and notification of information via sound. In this study, we demonstrate the facile fabrication of a Stretchable Acoustic Device (SAD) using liquid metal coil of Galinstan where the SAD is operated by the electromagnetic interaction between the liquid metal coil and a Neodymium (Nd) magnet. To fabricate a liquid metal coil, Galinstan was injected into a micro-patterned elastomer channel. This fabricated SAD was operated simultaneously as a loudspeaker and a microphone. Measurements of the frequency response confirmed that the SAD was mechanically stable under both 50% uniaxial and 30% biaxial strains. Furthermore, 2000 repetitive applications of a 50% uniaxial strain did not induce any noticeable degradation of the sound pressure. Both voice and the beeping sound of an alarm clock were successfully recorded and played back through our SAD while it was attached to the wrist under repeated deformation. These results demonstrate the high potential of the fabricated SAD using Galinstan voice coil in various research fields including stretchable, wearable, and bio-implantable acoustic devices.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Flexible Cu(In,Ga)(S,Se)2 (CIGSSe) solar cells were fabricated on stainless steel foil by using aqueous spray deposition method. Since stainless steel foil is used, external alkali doping is ...necessary to passivate defects in CIGSSe absorber. We investigated effects of (Na, K) co-doping and selenization temperature on solar cell performance. With co-doping of Na and K, defect states were passivated significantly and highest power conversion efficiency (PCE) was obtained. However, at higher K concentration of more than 0.5%, different growth mode of CIGSSe was observed and deep defect states were developed, decreasing PCE. In addition, selenization temperature effects were studied by varying selenization temperatures. With higher selenization temperature, defect passivation for the CIGSSe absorber was more apparent, which facilitated increase of open circuit voltage. However, short circuit current was observed to be decreased at higher selenization temperature of 570 °C. This work demonstrates in-situ alkali co-doping into CIGSSe absorber with simple and low-cost spray deposition in an air environment.
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•Flexible CIGSSe solar cells were fabricated using aqueous spray deposition in an air environment.•In situ co-doping of alkali elements for high quality CIGSSe absorber was demonstrated.•Co-doping with Na and K enabled significant defect passivation of CIGSSe absorber.•The flexible solar cells were fabricated with a narrow band gap (Eg = ∼1.1 eV) CIGSSe absorber.•The highest PCE of 11.45% was obtained due to the co-doping of Na and K.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The advent of optogenetic tools has allowed unprecedented insights into the organization of neuronal networks. Although recently developed technologies have enabled implementation of optogenetics for ...studies of brain function in freely moving, untethered animals, wireless powering and device durability pose challenges in studies of spinal cord circuits where dynamic, multidimensional motions against hard and soft surrounding tissues can lead to device degradation. We demonstrate here a fully implantable optoelectronic device powered by near-field wireless communication technology, with a thin and flexible open architecture that provides excellent mechanical durability, robust sealing against biofluid penetration and fidelity in wireless activation, thereby allowing for long-term optical stimulation of the spinal cord without constraint on the natural behaviors of the animals. The system consists of a double-layer, rectangular-shaped magnetic coil antenna connected to a microscale inorganic light-emitting diode (μ-ILED) on a thin, flexible probe that can be implanted just above the dura of the mouse spinal cord for effective stimulation of light-sensitive proteins expressed in neurons in the dorsal horn. Wireless optogenetic activation of TRPV1-ChR2 afferents with spinal μ-ILEDs causes nocifensive behaviors and robust real-time place aversion with sustained operation in animals over periods of several weeks to months. The relatively low-cost electronics required for control of the systems, together with the biocompatibility and robust operation of these devices will allow broad application of optogenetics in future studies of spinal circuits, as well as various peripheral targets, in awake, freely moving and untethered animals, where existing approaches have limited utility.
Abstract
Background
A foodborne pathogen,
Vibrio vulnificus
, encounters normal microflora inhabiting the gut environments prior to causing fatal septicemia or gastroenteritis and should overcome the ...barriers derived from the gut commensals for successful infection. Its interactions with gut commensals during the infection process, however, have not yet been understood. In the present study, the effect of
V. vulnificus
on the community structures of gut microbiota in mice was examined.
Results
Analyses of microbiota in the fecal samples of mice that died due to
V. vulnificus
infection revealed the decreased abundance of bacteria belonged to Bacteroidetes, notably, the species
Bacteroides vulgatus
. In vitro coculturing of the two bacterial species resulted in the decreased survival of
B. vulgatus
. The antagonistic effect of
V. vulnificus
against
B. vulgatus
was found to be mediated by cyclo-Phe-Pro (cFP), one of the major compounds secreted by
V. vulnificus
. cFP-treated
B. vulgatus
showed collapsed cellular morphology with an undulated cell surface, enlarged periplasmic space, and lysed membranes, suggesting the occurrence of membrane disruption. The degree of membrane disruption caused by cFP was dependent upon the cellular levels of ObgE in
B. vulgatus
. Recombinant ObgE exhibited a high affinity to cFP at a 1:1 ratio. When mice were orally injected with cFP, their feces contained significantly reduced
B. vulgatus
levels, and their susceptibility to
V. vulnificus
infection was considerably increased.
Conclusions
This study demonstrates that
V. vulnificus
-derived cFP modulates the abundance of the predominant species among gut commensals, which made
V. vulnificus
increase its pathogenicity in the hosts.
Objective
To describe the oral health of older people by region and family status using data from the National Health and Nutrition Survey.
Background
As the ageing of Korean society intensifies, ...health inequalities based on region and family status are also deepening.
Methods
Data from the 8th National Health and Nutrition Survey (2020–2021) conducted by the Korea Centers for Disease Control and Prevention were used, and a total of 3437 older people aged 65 or older were selected as study participants. Chewing discomfort and oral health behaviours were assessed by region and family status using multivariable logistic regression analysis with the complex sample survey design.
Results
We found an association between living alone and greater chewing discomfort. Residing in rural areas was also associated with a higher prevalence of this. In urban areas, chewing discomfort was 1.27 times higher among older people living alone than in those not living alone, while in rural areas, the discomfort was 1.52 times higher among the older people who lived alone.
Conclusions
Region and family status were associated with greater chewing discomfort in older people. In Korean society, where the number of single‐person older people households is increasing, along with the ageing population, attention to resolving the disparities in oral health in older people is needed.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The syntheses of novel 1-acyloxyindole compounds 1 and the investigations on reaction pathways are presented. Nitro ketoester substrate 2, obtained in a two-step synthetic process, underwent ...reduction, intramolecular addition, nucleophilic 1,5-addition, and acylation to afford 1-acyloxyindoles 1 in one pot. Based on the systematic studies, we established the optimized reaction conditions for 1 focusing on the final acylation step of the intermediate 1-hydroxyindole 8. With the optimized conditions, we succeeded in synthesizing 21 examples of new 1-acyloxyindole derivatives 1 in modest yields (Y = 24 − 35%). Among the 1-acyloxyindole compounds, 1-acetoxyindole compounds 1x were generally unstable, and their yields were relatively lower than the other 1-acyloxyindoles. We expect that a bulkier alkyl or aromatic group on R2 could stabilize the 1-acyloxyindole compounds. Significantly, one-pot reactions of a four-step sequence successfully generated compounds 1 that are all new and might be difficult to be synthesized otherwise.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The oral mucosa is an effective site for vaccination. However, for oral mucosal vaccines, delivery of the right dose of vaccine is not possible due to the water-rich environment. In this study, the ...buccal mucosa, which is easy to access using a microneedle array in the oral cavity, was selected as the administration site. The immune responses to the use of microneedles to conventional transmucosal delivery were compared. In addition, the adjuvant effect of the addition of cholera toxin (CT) to the drug formulation was observed. Two kinds of patches were prepared: (1) Ovalbumin (OVA) was dip coated only on the tips of microneedles (C-OVA-MN) and (2) OVA was coated on the surface of a flat disk patch substrate without microneedles (C-OVA-D). The drug delivery properties of C-OVA-MN and C-OVA-D were investigated using fluorescent-labeled OVA (OVA/FITC). Each patch was administered to mice twice, 2 weeks apart, and then antibody titers were measured. A microneedle patch can deliver vaccine into the epithelium of the buccal mucosa in a short period of time compared to transmucosal delivery. A microneedle system of C-OVA-MN showed a high serum IgG titer. In addition, CT triggered CD8
+
and CD4
+
T cell-mediated immune responses. Through this study, we present the possibility of a new method of vaccination to the buccal mucosa using microneedles and CT adjuvant.
Graphical abstract
Illustration of delivery of vaccine to the oral mucosal epithelium using a microneedle patch: Ovalbumin (OVA)-coated microneedle (C-OVA-MN) consists of tip, step, and coating formulation. Microneedle patch coated with OVA formulation is targeting buccal mucosa, which is easy to access in the oral cavity. OVA is delivered to the buccal epithelium precisely using a microneedle patch, and OVA is delivered by transmucosal route using a disk patch.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The studies on the selective synthesis of dialkyl selenide compounds 1 were presented. Overcoming the complexity and difficulty of selenides (R-Se-R) and/or multiselenides (R-Sen-R; n ≥ 2), we aimed ...to optimize the reaction condition for the tolerable preparation of sodium selenide (Na2Se) by reducing Se with NaBH4, and then to achieve selective syntheses of dialkyl selenides 1 by subsequently treating the obtained sodium selenide with alkyl halides (RX). Consequently, various dialkyl selenides 1 were efficiently synthesized in good-to-moderate yields. The investigations on reaction pathways and solvent studies were also described.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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