Ultra-Thin Ion Exchange Membranes by Low Ionomer Blending for Energy Harvesting.

Exploring the utilization of ion exchange membranes (IEMs) in salinity gradient energy harvesting, a technique that capitalizes on the salinity difference between seawater and freshwater to generate electricity, this study focuses on optimizing PVDF to Nafion ratios to create ultra-thin membranes. Specifically, our investigation aligns with applications such as reverse electrodialysis (RED), where IEMs facilitate selective ion transport across salinity gradients. We demonstrate that membranes with reduced Nafion content, particularly the 50:50 PVDF:Nafion blend, retain high permselectivity comparable to those with higher Nafion content. This challenges traditional understandings of membrane design, highlighting a balance between thinness and durability for energy efficiency. Voltage-current analyses reveal that, despite lower conductivity, the 50:50 blend shows superior short-circuit current density under salinity gradient conditions. This is attributed to effective ion diffusion facilitated by the blend's unique microstructure. These findings suggest that blended membranes are not only cost-effective but also exhibit enhanced performance for energy harvesting, making them promising candidates for sustainable energy solutions. Furthermore, these findings will pave the way for advances in membrane technology, offering new insights into the design and application of ion exchange membranes in renewable energy.

Ortho-Carborane Decorated Multi-Resonance TADF Emitters: Preserving Local Excited State and High Efficiency in OLEDs.

A novel class of o-carboranyl luminophores, 2CB-BuDABNA (1) and 3CB-BuDABNA (2) is reported, in which o-carborane moieties are incorporated at the periphery of the B,N-doped multi-resonance thermally activated delayed fluorescence (MR-TADF) core. Both compounds maintain the inherent local emission characteristics of their MR-emitting core, exhibiting intense MR-TADF with high photoluminescence quantum yields in toluene and rigid states. In contrast, the presence of the dark lowest-energy charge transfer state, induced by cage rotation in THF, is suggested to be responsible for emission quenching in a polar solvent. Despite the different arrangement of the cage on the DABNA core, both 1 and 2 show red-shifted emissions compared to the parent compound BuDABNA (3). By utilizing 1 as the emitter, high-efficiency blue organic light-emitting diodes (OLEDs) are achieved with a remarkable maximum external quantum efficiency of 25%, representing the highest reported efficiency for OLEDs employing an o-carboranyl luminophore as the emitter.

Associations of normal fasting glucose levels and of insulin resistance with degenerative rotator cuff tear : Normoglycemia and rotator cuff tear.

BACKGROUND: The upper normoglycemic range has been proposed as a risk factor for degenerative rotator cuff tendon tear (RCT), and insulin resistance has been suggested as a risk factor for tendinopathy. However, no research has established their association with degenerative RCT in the general population. This study aimed to determine whether fasting glucose levels and insulin resistance are risk factors for degenerative RCT in the normoglycemic population and identify the risk range for fasting glucose. METHODS: This study included 418 normoglycemic participants from a rural cohort. Participants completed questionnaires, physical exams, blood tests, and MRI evaluations of both shoulders. Insulin resistance was assessed using a triglyceride/high-density-lipoprotein (TG/HDL) ≥ 3.5. Logistic regression analysis was used to determine the association between fasting glucose level, TG/HDL ≥ 3.5, and other factors and degenerative RCT. The study calculated the areas under the receiver operating characteristic curve (AUC) to determine the more appropriate predicting value between the scale and categorical values of fasting glucose levels, and compared the AUCs using the DeLong method. RESULTS: In the multivariable analyses, both scale and categorical values of fasting glucose levels, and TG/HDL ≥ 3.5 were significantly associated with degenerative RCT. Fasting glucose levels ≥ 90.5 mg/dL (OR: 3.87, 95% CI: 2.10-7.06) in scale value and 90-99 mg/dL (OR: 4.13, 95% CI: 2.87-8.12) in categorical value were significantly associated with degenerative RCT (P < .001). The AUC of the scale value of fasting glucose levels ≥ 90.5 mg/dL was 0.68. The AUC of the categorical value of fasting glucose levels of 90-99 mg/dL was 0.70. Because of the significantly larger AUC of the categorical value of fasting glucose levels of 90-99 mg/dL, those fasting glucose levels were determined to be independently associated with degenerative RCT (P < .001). CONCLUSIONS: High fasting glucose levels within the normal range may link to increase insulin resistance and risk of degenerative RCT. Normoglycemic levels of 90-99 mg/dL and insulin resistance may be risk factors for degenerative RCT. LEVEL OF EVIDENCE: Level III, prognostic study.

Analysis of temperature effects on the protein accumulation of the FT-FD module using newly generated Arabidopsis transgenic plants.

Arabidopsis flowering is dependent on interactions between a component of the florigens FLOWERING LOCUS T (FT) and the basic leucine zipper (bZIP) transcription factor FD. These proteins form a complex that activates the genes required for flowering competence and integrates environmental cues, such as photoperiod and temperature. However, it remains largely unknown how FT and FD are regulated at the protein level. To address this, we created FT transgenic plants that express the N-terminal FLAG-tagged FT fusion protein under the control of its own promoter in ft mutant backgrounds. FT transgenic plants complemented the delayed flowering of the ft mutant and exhibited similar FT expression patterns to wild-type Col-0 plants in response to changes in photoperiod and temperature. Similarly, we generated FD transgenic plants in fd mutant backgrounds that express the N-terminal MYC-tagged FD fusion protein under the FD promoter, rescuing the late flowering phenotypes in the fd mutant. Using these transgenic plants, we investigated how temperature regulates the expression of FT and FD proteins. Temperature-dependent changes in FT and FD protein levels are primarily regulated at the transcript level, but protein-level temperature effects have also been observed to some extent. In addition, our examination of the expression patterns of FT and FD in different tissues revealed that similar to the spatial expression pattern of FT, FD mRNA was expressed in both the leaf and shoot apex, but FD protein was only detected in the apex, suggesting a regulatory mechanism that restricts FD protein expression in the leaf during the vegetative growth phase. These transgenic plants provided a valuable platform for investigating the role of the FT-FD module in flowering time regulation.

Modulation of warm temperature-sensitive growth using a phytochrome B dark reversion variant, phyB[G515E], in Arabidopsis and rice.

INTRODUCTION: Ambient temperature-induced hypocotyl elongation in Arabidopsis seedlings is sensed by the epidermis-localized phytochrome B (phyB) and transduced into auxin biosynthesis via a basic helix-loop-helix transcription factor, phytochrome-interacting factor 4 (PIF4). Once synthesized, auxin travels down from the cotyledons to the hypocotyl, triggering hypocotyl cell elongation. Thus, the phyB-PIF4 module involved in thermosensing and signal transduction is a potential genetic target for engineering warm temperature-insensitive plants. OBJECTIVES: This study aims to manipulate warm temperature-induced elongation of plants at the post-translational level using phyB variants with dark reversion, the expression of which is subjected to heat stress. METHODS: The thermosensitive growth response of Arabidopsis was manipulated by expressing the single amino acid substitution variant of phyB (phyB[G515E]), which exhibited a lower dark reversion rate than wild-type phyB. Other variants with slow (phyB[G564E]) or rapid (phyB[S584F]) dark reversion or light insensitivity (phyB[G767R]) were also included in this study for comparison. Warming-induced transient expression of phyB variants was achieved using heat shock-inducible promoters. Arabidopsis PHYB[G515E] and PHYB[G564E] were also constitutively expressed in rice in an attempt to manipulate the heat sensitivity of a monocotyledonous plant species. RESULTS: At an elevated temperature, Arabidopsis seedlings transiently expressing PHYB[G515E] under the control of a heat shock-inducible promoter exhibited shorter hypocotyls than those expressing PHYB and other PHYB variant genes. This warm temperature-insensitive growth was related to the lowered PIF4 and auxin responses. In addition, transgenic rice seedlings expressing Arabidopsis PHYB[G515E] and PHYB[G564E] showed warm temperature-insensitive shoot growth. CONCLUSION: Transient expression of phyB variants with altered dark reversion rates could serve as an effective optogenetic technique for manipulating PIF4-auxin-mediated thermomorphogenic responses in plants.

The first high-quality genome assembly and annotation of Patiria pectinifera.

The blue bat star, a highly adaptive species in the East Sea of Korea, has displayed remarkable success in adapting to recent climate change. The genetic mechanisms behind this success were not well-understood, prompting our report on the first chromosome-level assembly of the Patiria genus. We assembled the genome using Nanopore and Illumina sequences, yielding a total length of 615 Mb and a scaffold N50 of 24,204,423 bp. Hi-C analysis allowed us to anchor the scaffold sequences onto 22 pseudochromosomes. K-mer based analysis revealed 5.16% heterozygosity rate of the genome, higher than any previously reported echinoderm species. Our transposable element analysis exposed a substantial number of genome-wide retrotransposons and DNA transposons. These results offer valuable resources for understanding the evolutionary mechanisms behind P. pectinifera's successful adaptation in fluctuating environments.

Production and engineering of nanobody-based quenchbody sensors for detecting recombinant human growth hormone and its isoforms.

Due to athletes' misuse of recombinant human growth hormone (rhGH) for performance improvement, the World Anti-Doping Agency has designated rhGH as a prohibited substance. This study focuses on the development and improvement of a simple and fast rhGH detection method using a fluorescence-incorporated antibody sensor "Quenchbody (Q-body)" that activates upon antigen binding. Camelid-derived nanobodies were used to produce stable Q-bodies that withstand high temperatures and pH levels. Notably, pituitary human growth hormone (phGH) comprises two major isoforms, namely 22 and 20 kDa GH, which exist in a specific ratio, and the rhGH variant shares the same sequence as the 22 kDa GH isoform. Therefore, we aimed to discriminate rhGH abuse by analyzing its specific isoform ratio. Two nanobodies, NbPit (recognizing phGH) and NbRec (preferentially recognizing 22 kDa rhGH), were used to develop the Q-bodies. Nanobody production in Escherichia coli involved the utilization of a vector containing 6xHis-tag, and Q-bodies were obtained using a maleimide-thiol reaction between the N-terminal of the cysteine tag and a fluorescent dye. The addition of tryptophan residue through antibody engineering resulted in increased fluorescence intensity (FI) (from 2.58-fold to 3.04-fold). The limit of detection (LOD) was determined using a fluorescence response, with TAMRA-labeled NbRec successfully detecting 6.38 ng/ml of 22 kDa rhGH while unable to detect 20 kDa GH. However, ATTO520-labeled NbPit detected 7.00 ng/ml of 20 kDa GH and 2.20 ng/ml 22 kDa rhGH. Q-bodies successfully detected changes in the GH concentration ratio from 10 to 40 ng/ml in human serum within 10 min without requiring specialized equipment and kits. Overall, these findings have potential applications in the field of anti-doping measures and can contribute to improved monitoring and enforcement of rhGH misuse, ultimately enhancing fairness and integrity in competitive sports.

Chromosome-level genome assembly of Korean native cattle and pangenome graph of 14 Bos taurus assemblies.

This study presents the first chromosome-level genome assembly of Hanwoo, an indigenous Korean breed of Bos taurus taurus. This is the first genome assembly of Asian taurus breed. Also, we constructed a pangenome graph of 14 B. taurus genome assemblies. The contig N50 was over 55 Mb, the scaffold N50 was over 89 Mb and a genome completeness of 95.8%, as estimated by BUSCO using the mammalian set, indicated a high-quality assembly. 48.7% of the genome comprised various repetitive elements, including DNAs, tandem repeats, long interspersed nuclear elements, and simple repeats. A total of 27,314 protein-coding genes were identified, including 25,302 proteins with inferred gene names and 2,012 unknown proteins. The pangenome graph of 14 B. taurus autosomes revealed 528.47 Mb non-reference regions in total and 61.87 Mb Hanwoo-specific regions. Our Hanwoo assembly and pangenome graph provide valuable resources for studying B. taurus populations.

25 Years of thermomorphogenesis research: milestones and perspectives.

In 1998, Bill Gray and colleagues showed that warm temperatures trigger arabidopsis hypocotyl elongation in an auxin-dependent manner. This laid the foundation for a vibrant research discipline. With several active members of the 'thermomorphogenesis' community, we here reflect on 25 years of elevated ambient temperature research and look to the future.

Triptycene-Fused Sterically Shielded Multi-Resonance TADF Emitter Enables High-Efficiency Deep Blue OLEDs with Reduced Dexter Energy Transfer.

Designing multi-resonance (MR) emitters that can simultaneously achieve narrowband emission and suppressed intermolecular interactions is challenging for realizing high color purity and stable blue organic light-emitting diodes (OLEDs). Herein, a sterically shielded yet extremely rigid emitter based on a triptycene-fused B,N core (Tp-DABNA) is proposed to address the issue. Tp-DABNA exhibits intense deep blue emissions with a narrow full width at half maximum (FWHM) and a high horizontal transition dipole ratio, superior to the well-known bulky emitter, t-DABNA. The rigid MR skeleton of Tp-DABNA suppresses structural relaxation in the excited state, with reduced contributions from the medium- and high-frequency vibrational modes to spectral broadening. The hyperfluorescence (HF) film composed of a sensitizer and Tp-DABNA shows reduced Dexter energy transfer compared to those of t-DABNA and DABNA-1. Notably, deep blue TADF-OLEDs with the Tp-DABNA emitter display higher external quantum efficiencies (EQEmax =24.8 %) and narrower FWHMs (≤26 nm) than t-DABNA-based OLEDs (EQEmax =19.8 %). The HF-OLEDs based on the Tp-DABNA emitter further demonstrate improved performance with an EQEmax of 28.7 % and mitigated efficiency roll-offs.

Temperature perception by plants.

Plants constantly face fluctuating ambient temperatures and must adapt to survive under stressful conditions. Temperature affects many aspects of plant growth and development through a complex network of transcriptional responses. Although temperature sensing is a crucial primary step in initiating transcriptional responses via Ca2+ and/or reactive oxygen species signaling, an understanding of how plants perceive temperature has remained elusive. However, recent studies have yielded breakthroughs in our understanding of temperature sensors and thermosensation mechanisms. We review recent findings on potential temperature sensors and emerging thermosensation mechanisms, including biomolecular condensate formation through phase separation in plants. We also compare the temperature perception mechanisms of plants with those of other organisms to provide insights into understanding temperature sensing by plants.

Impact of π-Expanded Boron-Carbonyl Hybrid Acceptors on TADF Properties: Controlling Local Triplet Excited States and Unusual Emission Tuning.

Three donor-acceptor-type thermally activated delayed fluorescence (TADF) emitters (PXZBAO (1), PXZBTO (2), and PXZBPO (3)) comprising a phenoxazine (PXZ) donor and differently π-expanded boron-carbonyl (BCO) hybrid acceptor units are proposed. The emitters exhibit red (1) to orange (3) emissions with an increase in the π-expansion in the BCO acceptors. The control of the strength of local aromaticity for the BCO unit and the corresponding LUMO level is attributed to inducing the unusual emission color shifts. The photoluminescence quantum yield and delayed fluorescence lifetime of the emitters are also adjusted by the π-expansion. Notably, although 1 possesses a 3nπ* state in the acceptor unit as a local triplet excited state (3LE, T2), the T2 states of 2 and 3 mainly comprise a 3ππ* state in the acceptor. Consequently, all of the emitters exhibit strong spin-orbit coupling between their T2 and excited singlet (S1) states, leading to a fast reverse intersystem crossing with rate constants of ∼106 s-1. By employing the emitters as dopants, we realize efficient red-to-orange TADF-OLEDs. Maximum external quantum efficiencies of 17.7% for the yellowish-orange (3), 15.5% for the orange (2), and 13.9% for the red (1) devices are achieved, and the values are very close to the theoretical limit predicted from the optical simulation.

Discovery and Binding Mechanism of Pyrazoloisoquinoline-Based Novel ß-Arrestin Inverse Agonists of the Kappa-Opioid Receptor.

Chronic exposure to stress or unwanted stimuli has been known to activate kappa opioid receptor/dynorphin (KOR/DYN) systems, which could induce depressive states and develop into some psychiatric disorders. Here, we report the first discovery of pyrazoloisoquinoline-based novel KOR ß-arrestin inverse agonists through synthesis, structure-activity relationships, optimization, and the biological evaluations of µ/κ/δ opioid receptor activities with cAMP and ß-arrestin recruitment assays. The optimized compound 7q shows potent and selective ß-arrestin inverse agonism at KOR with an EC50 value of 9.33 nM in contrast to lower activities at DOR and no activity at MOR. Moreover, we use molecular dynamics simulations to predict the binding mode of the inverse agonist and propose a mechanism for the inverse agonism. We find that the transmembrane helix 6 position of the activated state is different for the OR subtypes, leading to significantly different interactions between the receptor and ß-arrestin.

A straightforward strategy for reducing variability in flowering time at warm ambient temperatures.

Ambient temperature is one of the major environmental factors affecting flowering. As the temperature rises, most plants, including Arabidopsis, flower more rapidly. In addition, phenotypic variability in flowering time tends to increase at warm ambient temperatures. The increased variability of flowering time at warm temperatures prevents accurate flowering time measurements, particularly when evaluating the flowering time of Arabidopsis plants under short-day conditions in order to restrict the photoperiodic effect. Here, we propose a simple method for reducing the variability of flowering time at warm temperatures. Instead of growing plants at different temperatures from germination, the strategy of first vegetative growth at cool temperatures and then shifting to warm temperatures allows plants to respond more stably and robustly to warm temperatures. Consistent with flowering time measurements, plants grown under the modified growth condition exhibited higher levels of FLOWERING LOCUS T (FT) gene expression than plants grown exclusively at warm temperatures. This approach enables more precise thermo-response studies of flowering time control in Arabidopsis.

Critical Role of Surface Termination of Sapphire Substrates in Crystallographic Epitaxial Growth of MoS2 Using Inorganic Molecular Precursors.

A highly reproducible route for the epitaxial growth of single-crystalline monolayer MoS2 on a C-plane sapphire substrate was developed using vapor-pressure-controllable inorganic molecular precursors MoOCl4 and H2S. Microscopic, crystallographic, and spectroscopic analyses indicated that the epitaxial MoS2 film possessed outstanding electrical and optical properties, excellent homogeneity, and orientation selectivity. The systematic investigation of the effect of growth temperature on the crystallographic orientations of MoS2 revealed that the surface termination of the sapphire substrate with respect to the growth temperature determines the crystallographic orientation selectivity of MoS2. Our results suggest that controlling the surface to form a half-Al-terminated surface is a prerequisite for the epitaxial growth of MoS2 on a C-plane sapphire substrate. The insights on the growth mechanism, especially the significance of substrate surface termination, obtained through this study will aid in designing efficient epitaxial growth routes for developing single-crystalline monolayer transition metal dichalcogenides.

The Efficacy of Treatment Intensification by Quadruple Oral Therapy Compared to GLP-1RA Therapy in Poorly Controlled Type 2 Diabetes Mellitus Patients: A Real-world Data Study.

We compared the glycemic efficacy of treatment intensification between quadruple oral antidiabetic drug therapy and once-weekly glucagon-like peptide-1 receptor agonist (GLP-1RA)-based triple therapy in patients with poorly controlled type 2 diabetes mellitus refractory to triple oral therapy. For 24 weeks, changes in glycosylated hemoglobin (HbA1c) from baseline were compared between the two treatment groups. Of all 96 patients, 50 patients were treated with quadruple therapy, and 46 were treated with GLP-1RA therapy. Reductions in HbA1c for 24 weeks were comparable (in both, 1.1% reduction from baseline; P=0.59). Meanwhile, lower C-peptide level was associated with a lower glucose-lowering response of GLP-1RA therapy (R=0.3, P=0.04) but not with quadruple therapy (R=-0.13, P=0.40). HbA1c reduction by GLP-1RA therapy was inferior to that by quadruple therapy in the low C-peptide subgroup (mean, -0.1% vs. -1.3%; P=0.04). Treatment intensification by switching to quadruple oral therapy showed similar glucose-lowering efficacy to weekly GLP-1RA-based triple therapy. Meanwhile, the therapeutic response was affected by C-peptide levels in the GLP-1RA therapy group but not in the quadruple therapy group.

BILATERAL MACULAR CHOROIDAL ABNORMALITIES WITH DRUSENOID DEPOSITS IN PATIENTS WITH UNILATERAL PERIPHERAL EXUDATIVE HEMORRHAGIC CHORIORETINOPATHY.

PURPOSE: To investigate bilateral macular features on optical coherence tomography in patients with unilateral peripheral exudative hemorrhagic chorioretinopathy (PEHCR). METHODS: In this cross-sectional study, optical coherence tomography features of affected eyes (PEHCR group, n = 30) and unaffected contralateral eyes (contralateral group, n = 30) were investigated. Age-matched and sex-matched patients with polypoidal choroidal vasculopathy (PCV group, n = 51) and healthy controls (normal group, n = 50) were included to compare choroidal thickness, measured at six points apart from the fovea, with the PEHCR group. RESULTS: Subretinal drusenoid deposits were the most common feature in the PEHCR (20%) and contralateral (23%) groups, followed by soft drusen. Although the macular choroid was comparably thin in both the PEHCR and contralateral groups, pachyvessels were also observed. The choroids of the PEHCR group were significantly thinner than those of the normal group at the subfovea and 1-mm temporal to the fovea and considerably thinner than those of the polypoidal choroidal vasculopathy group from 3-mm nasal to 3-mm temporal to the fovea. CONCLUSION: In patients with unilateral PEHCR, bilateral choroidal thinning and drusenoid deposit accumulation were noted in the macula. The pathophysiology of PEHCR may be a rare peripheral complication of age-related macular degeneration with pathologic choroid.

Highly emissive planarized B,N-diarylated benzonaphthoazaborine compounds for narrowband blue fluorescence.

Highly fluorescent blue emitters with high color purity are of great significance for optical applications. Herein, a series of planarized B,N-diarylated benzonaphthoazaborine compounds, namely, BzNp (1), BuBzNp (2), Bu2BzNp (3), Bu2BzMeNp (4), and Bu2BzBuNp (5), where electron-donating t Bu and Me groups are differently introduced into the B-Ph, N-Ph, or benzoazaborine rings, are prepared and characterized. All compounds exhibit low-energy absorptions (λ abs = 462-467 nm) and emissions (λ PL = 472-478 nm) remarkably red-shifted compared with those found for the pristine dibenzoazaborine compound (404 and 415 nm, respectively). Although the expansion of π-conjugation in the azaborine ring by replacing one phenyl ring with a naphthyl ring is mainly responsible for the redshifts, the emission is also fine-tuned by attached alkyl groups, which have a greater impact on the B-centered LUMO level at the azaborine ring than at the B-Ph ring. The bandgap control and emission tuning are further supported by electrochemical and theoretical studies. Notably, blue to sky-blue fluorescence of all compounds exhibits unitary photoluminescence quantum yields, narrow full width at half maximum values (∼20 nm), and small Stokes shifts (∼11 nm), indicating strong emissions with high color purity.

Functional Constipation is Associated with a Decline in Word Recognition 2 Years Later in Community-Dwelling Older Adults: The Korean Frailty and Aging Cohort Study.

BACKGROUND: Consumption and cognitive impairment are the most common health problems among older adults. This study aimed to determine the effects of functional constipation on cognitive decline in community-dwelling older adults. METHODS: This was a 2-year longitudinal analysis of Korean Frailty and Aging Cohort Study data, including 851 community-dwelling residents who participated in both the baseline and follow-up surveys. A neuropsychological test, the Consortium to Establish a Registry for Alzheimer's Disease Assessment Battery (CERAD-K), and the Korean version of the Frontal Assessment Battery (FAB) were used to evaluate cognitive function. Functional constipation was defined according to the ROME IV criteria. An analysis of covariance was used to identify the association between functional constipation and cognitive decline. RESULTS: Among the 851 participants, 8.9% had functional constipation. The patients in the constipation group were more likely to have low physical activity (15.8% vs. 8.8%), polypharmacy (61.8% vs. 45.5%), and depression (30.3% vs. 17.4%) than the non-constipation group. After adjusting for potential confounding factors, including age, sex, education years, low physical activity, polypharmacy, type 2 diabetes mellitus, depression, and baseline Cognitive Function Test score, the mean changes in Word Recognition test scores from 2018 to 2020 were -0.07 and -0.54 in the non-constipation and constipation groups, respectively (p=0.007). Other cognitive function tests (Mini-Mental State Examination, word list memory, word list recall, digit span, trail-making test, and FAB) did not show any difference in decline between the two groups (p>0.05). CONCLUSIONS: Functional constipation at baseline was associated with a decline in word recognition after 2 years.

Accelerated Cognitive Function Decline in Community-Dwelling Older Adults during COVID-19 Pandemic: The Korean Frailty and Aging Cohort Study (KFACS).

This study aimed to analyze the effect of the COVID-19 pandemic on cognitive function of community-dwelling elderly individuals. Five-year (2016 to 2020) longitudinal data of the Korea Frailty and Aging Cohort Study (KFACS) were used. There were 1559 participants in 2016 and 1455 in 2017 aged 72-84 years. Follow-up was conducted at two-year intervals. We selected participants from the database of the 2017 and 2018 surveys for intergroup comparison over 2-year follow-ups. The number of study patients in the 2017-Group was 1027 and that of the 2018-Group was 879. In the intergroup comparison, the mean difference of word list memory score from 2018 to 2020 was -0.14, while that from 2017 to 2019 was 0.53. The mean difference of word list recall score from 2018 to 2020 was -0.25, while that from 2017 to 2019 was 0.03. These were significant even after adjusting confounding variables. In the intragroup comparison, the word list memory and recall scores from 2018 to 2020 were more decreased than those from 2016 to 2018. Conclusively, cognitive function of the Korean elderly cohort declined much more during the COVID-19 pandemic than before the pandemic, particularly in terms of memory and recall function.