A seamless auxetic substrate with a negative Poisson's ratio of -1.

Auxetic metamaterials are a unique class of materials or structures with a negative Poisson's ratio and a wide array of functionalities. However, their inherent porosity presents challenges in practical applications. Filling the inherent perforations while preserving their unique auxeticity is difficult because it demands the seamless integration of components that have highly distinct mechanical characteristics. Here we introduce a seamless auxetic substrate film capable of achieving a negative Poisson's ratio of -1, the theoretical limit of isotropic materials. This breakthrough is realized by incorporating a highly rigid auxetic structure reinforced by glass-fabric, with surface-flattening soft elastomers. We effectively optimize the mechanical properties of these components by systematic experimental and theoretical investigations into the effects of relative differences in the moduli of the constituents. Using the developed auxetic film we demonstrate an image distortion-free display having 25 PPI resolution of micro-LEDs that is capable of 25% stretching without performance degradation.

Metal-Organic Frameworks as a Thermal Emitter for High-Performance Passive Radiative Cooling.

Passive radiative cooling represents a transformative approach to achieving sustainable cooling on Earth without relying on energy consumption. In this research, the optical characteristics of five readily accessible metal-organic frameworks (MOFs): ZIF-67(Co), MOF-74(Ni), HKUST-1(Cu), MOF-801(Zr), and UiO-66(Zr) are meticulously explored. The objective is to identify the pivotal factors that influence their ability to facilitate radiative cooling. Through an in-depth analysis encompassing spectroscopic features, surface texture, and porosity, it is found that the MOFs' cooling efficacy is largely influenced by their optical bandgaps and functional groups, although other factors like chemical composition and structural characteristics remain to be considered. Notably, UiO-66(Zr) emerged as the standout performer, boasting an impressive solar reflectance of 91% and a mid-infrared emissivity of 96.8%. Remarkably, a fabric treated with UiO-66(Zr) achieved a substantial sub-ambient cooling effect, lowering temperatures by up to 5 °C and delivering a cooling power of 26 W m-2 at 300 K. The findings underscore the vast potential of MOFs in offering new opportunities to advance passive radiative cooling technologies, paving the way for their extensive application in this field.

The Impact of Transcatheter Aortic Valve Implantation on Healthcare Costs and Clinical Outcomes Based on Frailty Risk: A Nationwide Cohort Analysis.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is preferred for treating severe aortic stenosis in older, frail populations, yet the impact of frailty on TAVI's economic and clinical outcomes is not well-studied. METHODS: This retrospective cohort study included 2,175 TAVI patients from 2015 to 2019 using Korea's National Health Insurance Service database, stratifying patients into low, intermediate, and high-frailty groups using the Hospital Frailty Risk Score (HFRS). Healthcare costs, admissions, and total length of hospitalization were analyzed using Wilcoxon-rank test 12 months pre- and post-TAVI. Composite endpoint of death, stroke, and major bleeding, with individual outcomes, were compared using Chi-squared tests and Kaplan-Meier analysis. RESULTS: Mean age was 80.2 years, and 47.3% were male. 747 (34.3%) were low-frailty, 1,159 (53.3%) were moderate-frailty, and 269 (12.4%) were high-frailty. After TAVI, medical costs decreased in the intermediate (pre-TAVI: 2,269,000 KRW [1,668 USD], post-TAVI: 1,607,000 KRW [1,181 USD], p<0.001) and high frailty groups (pre-TAVI: 3,949,000 KRW [2,904 USD], post-TAVI: 2,188,000 KRW [1,609 USD], p<0.001). All frailty groups had shorter length of hospital stay post-TAVI (26 to 21 days in the low, 44 to 31 days in the intermediate, and 65 to 41 days in the high frailty group; all p<0.001). The composite outcome was higher in the frailer groups (27.8% in the low vs. 31.5% in the intermediate vs. and 37.9% in the high frailty group; p=0.008). All groups showed comparable rates of cardiovascular death, stroke or bleeding. CONCLUSION: TAVI is clinically viable and cost-saving treatment option for frail patients with severe aortic stenosis.

Geometric feature extraction in nanofiber membrane image based on convolution neural network for surface roughness prediction.

As a technique in artificial intelligence, a convolution neural network model has been utilized to extract average surface roughness from the geometric characteristics of a membrane image featuring micro- and nanostructures. For surface roughness measurement, e.g. atomic force microscopy and optical profiler, the previous methods have been performed to analyze a porous membrane surface on an interest of region with a few micrometers of the restricted area according to the depth resolution. However, an image from the scanning electron microscope, combined with the feature extraction process, provides clarity on surface roughness for multiple areas with various depth resolutions. Through image preprocessing, the geometric pattern is elucidated by amplifying the disparity in pixel intensity values between the bright and dark regions of the image. The geometric pattern of the binary image and magnitude spectrum confirmed the classification of the surface roughness of images in a categorical scatter plot. A group of cropped images from an original image is used to predict the logarithmic average surface roughness values. The model predicted 4.80 % MAPE for the test dataset. The method of extracting geometric patterns through a feature map-based CNN, combined with a statistical approach, suggests an indirect surface measurement. The process is achieved through a bundle of predicted output data, which helps reduce the randomness error of the structural characteristics. A novel feature extraction approach of CNN with statistical analysis is a valuable method for revealing hidden physical characteristics in surface geometries from irregular pixel patterns in an array of images.

Outcomes of retropupillary iris claw lens implantation in patients with intraocular lens dislocation and low (less than 1000 cells/mm2) corneal endothelial cell density.

BACKGROUND: Posterior chamber intraocular lens (IOL) dislocation is a common complication of cataract surgery. Dislocated IOLs often require surgical intervention due to the potentially severe risks of leaving this condition untreated. If a patient with extremely low corneal endothelial cell density (ECD) presents with IOL dislocation, the surgeon faces a crucial dilemma of choosing the most optimal surgical treatment option. We sought to investigate the efficacy and safety of retropupillary iris claw intraocular lens (R-IOL) implantation in patients with IOL dislocation and extremely low (< 1000 cells/mm2) ECD. METHODS: We retrospectively reviewed the medical records of nine patients (all men) whose pre-operative ECD was < 1000 cells/mm2 and who underwent R-IOL implantation due to intraocular subluxation or total dislocation into the vitreous cavity between 2014 and 2020. We evaluated corneal endothelial function and visual outcomes after surgery. RESULTS: Nine patients were included in this study. The mean age at diagnosis was 64.89 ± 7.15 years (range 57-76 years), and the follow-up duration was 37.93 ± 23.72 months (range 18.07-89.07 months). No patients developed bullous keratopathy during follow-up. Compared to the initial ECD, corneal thickness (CT), coefficient variation of cell area (CV) and percentage of hexagonal cells (HEX), there was no statistically significant decrease in the ECD, CV, and HEX at last follow-up (P = 0.944, 0.778, 0.445, 0.443). There was significant improvement in the mean uncorrected distance visual acuity (UDVA) at the last follow-up (average 0.13 logMAR, 20/27 Snellen) compared to the pre-operative mean UDVA (average 1.09 logMAR, 20/250 Snellen) (P < 0.01). CONCLUSIONS: R-IOL implantation did not result in a statistically significant decline in corneal endothelial function in patients with preoperatively low ECD, and it significantly improved the mean UDVA postoperatively. R-IOL implantation appears to be a safe and effective treatment modality for intraocular lens dislocation in patients with low ECD (< 1000 cells/mm²); however, long-term follow-up studies are warranted to corroborate these findings.

Antioxidant and Skin-Whitening Efficacy of a Novel Decapeptide (DP, KGYSSYICDK) Derived from Fish By-Products.

The skin is vulnerable to damage from ultraviolet rays and oxidative stress, which can lead to aging and pigmentation issues. This study investigates the antioxidant and whitening efficacy of a decapeptide (DP, KGYSSYICDK) derived from marine fish by-products and evaluates its potential as a new skin-whitening agent. DP demonstrated high antioxidant activity, showing comparable or superior performance to Vitamin C (Vit. C) in ferric reducing antioxidant power (FRAP) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. In hydrogen peroxide (H2O2)-treated HaCaT cells, DP increased cell viability and reduced reactive oxygen species (ROS) generation. Furthermore, DP inhibited tyrosinase activity and decreased melanin production in α-melanocyte stimulating hormone (α-MSH)-induced B16F10 melanoma cells in a dose-dependent manner. Reverse transcription polymerase chain reaction (RT-PCR) analysis revealed that DP reduces the mRNA expression of MITF, tyrosinase, and MC1R, thus suppressing melanin production. DP exhibits strong binding interactions with multiple amino acid residues of tyrosinase, indicating potent inhibitory effects on the enzyme. These results suggest that DP possesses significant antioxidant and whitening properties, highlighting its potential as a skin-whitening agent. Future research should focus on optimizing DP's structure and exploring structure-activity relationships.

Development and validation of enzyme-linked immunosorbent assay for anti-mouse pertussis immunoglobulin G using international reference anti-Bordetella pertussis mouse serum NIBSC 97/642.

Purpose: In this study, an in-house enzyme-linked immunosorbent assay (ELISA) was developed and validated. The titer of ELISA was calculated using the reference line (RFL) method based on the standard curve drawn using the international reference anti-mouse serum NIBSC (National Institute for Biological Standards and Control) 97/642. Materials and Methods: In the development step, signal to noise was depicted to select the buffers that showed the most appropriate ratio. In the validation step, standard range, precision, dilution linearity, and specificity were confirmed, and RFL and parallel line (PLL) methods were compared in precision and dilution linearity. Results: Coating concentration for plate was achieved at 0.1 µg/mL for pertussis toxin (PT), 0.15 µg/mL for filamentous hemagglutinin antigen (FHA), and 0.25 µg/mL for pertactin (PRN). The signal to noise ratio was 22.02 for PT, 14.93 for FHA, and 8.02 for PRN with 0.25% goat serum in phosphate-buffered saline (PBS) as a dilution buffer, and 2% skim milk in PBS as a blocking buffer. Based on the precision results, we assessed the lower limit of quantification by 1, 0.2, and 1.5 EU/mL concentration for PT, FHA, and PRN which met the ICH (International Council for Harmonization) M10 criteria of a 25% accuracy and total error of 40%. In specificity, homologous serum was spiked into heterologous serum and the accuracy met the criteria. There was no difference in the results between RFL and PLL calculations (p-value=0.3207 for PT, 0.7394 for FHA, 0.2109 for PRN). Conclusion: ELISA validated with RFL calculation method in this study is a relatively accurate assay for mouse humoral immunogenicity test.

Capillary Flow-Based One-Minute Quantification of Amyloid Proteolysis.

Quantifying the formation and decomposition of amyloid is a crucial issue in the development of new drugs and therapies for treating amyloidosis. The current technologies for grasping amyloid formation and decomposition include fluorescence analysis using thioflavin-T, secondary structure analysis using circular dichroism, and image analysis using atomic force microscopy or transmission electron microscopy. These technologies typically require spectroscopic devices or expensive nanoscale imaging equipment and involve lengthy analysis, which limits the rapid screening of amyloid-degrading drugs. In this study, we introduce a technology for rapidly assessing amyloid decomposition using capillary flow-based paper (CFP). Amyloid solutions exhibit gel-like physical properties due to insoluble denatured polymers, resulting in a shorter flow distance on CFP compared to pure water. Experimental conditions were established to consistently control the flow distance based on a hen-egg-white lysozyme amyloid solution. It was confirmed that as amyloid is decomposed by trypsin, the flow distance increases on the CFP. Our method is highly useful for detecting changes in the gel properties of amyloid solutions within a minute, and we anticipate its use in the rapid, large-scale screening of anti-amyloid agents in the future.

Regenerative Role of Lrig1+ Cells in Kidney Repair.

BACKGROUND: In response to severe kidney injury, the kidney epithelium displays remarkable regenerative capabilities driven by adaptable resident epithelial cells. To date, it has been widely considered that the adult kidney lacks multipotent stem cells; thus, the cellular lineages responsible for repairing proximal tubule damage are incompletely understood. Leucine-rich repeats and immunoglobulin-like domains protein 1-expressing cells (Lrig1+ cells) have been identified as a long-lived cell in various tissues that can induce epithelial tissue repair. Therefore, we hypothesized that Lrig1+ cells participate in kidney development and tissue regeneration. METHODS: We investigated the role of Lrig1+ cells in kidney injury using mouse models. The localization of Lrig1+ cells in the kidney was examined throughout mouse development. The function of Lrig1+ progeny cells in acute kidney injury repair was examined in vivo using a tamoxifen-inducible Lrig1-specific Cre recombinase-based lineage tracing in three different kidney injury mouse models. Additionally, we conducted single-cell RNA-sequencing to characterize the transcriptional signature of Lrig1+ cells and to trace their progeny. RESULTS: Lrig1+ cells were present during kidney development and contributed to formation of the proximal tubule and collecting duct structures in mature mouse kidneys. In three-dimensional culture, single Lrig1+ cells demonstrated long-lasting propagation and differentiated into the proximal tubule and collecting duct lineages. These Lrig1+ proximal tubule cells highly expressed progenitor-like and quiescence-related genes, giving rise to a novel cluster of cells with regenerative potential in adult kidneys. Moreover, these long-lived Lrig1+ cells expanded and repaired damaged proximal tubules in response to three types of acute kidney injury in mice. CONCLUSIONS: These findings highlight the critical role of Lrig1+ cells in kidney regeneration.

CD47;Rag2;IL-2rγ triple knock-out mice pre-conditioning with busulfan could be a novel platform for generating hematopoietic stem cells engrafted humanized mice.

Introduction: Humanized mouse models to recapitulate human biological systems still have limitations, such as the onset of lethal graft-versus-host disease (GvHD), a variable success rate, and the low accessibility of total body irradiation (TBI). Recently, mice modified with the CD47-SIRPA axis have been studied to improve humanized mouse models. However, such trials have been rarely applied in NOD mice. In this study, we created a novel mouse strain, NOD-CD47nullRag2nullIL-2rγnull (RTKO) mice, and applied it to generate humanized mice. Methods: Four-week-old female NOD-Rag2nullIL-2rγnull (RID) and RTKO mice pre-conditioned with TBI or busulfan (BSF) injection were used for generating human CD34+ hematopoietic stem cell (HSC) engrafted humanized mice. Clinical signs were observed twice a week, and body weight was measured once a week. Flow cytometry for human leukocyte antigens was performed at intervals of four weeks or two weeks, and mice were sacrificed at 48 weeks after HSC injection. Results: For a long period from 16 to 40 weeks post transplantation, the percentage of hCD45 was mostly maintained above 25% in all groups, and it was sustained the longest and highest in the RTKO BSF group. Reconstruction of human leukocytes, including hCD3, was also most prominent in the RTKO BSF group. Only two mice died before 40 weeks post transplantation in all groups, and there were no life-threatening GvHD lesions except in the dead mice. The occurrence of GvHD has been identified as mainly due to human T cells infiltrating tissues and their related cytokines. Discussion: Humanized mouse models under all conditions applied in this study are considered suitable models for long-term experiments based on the improvement of human leukocytes reconstruction and the stable animal health. Especially, RTKO mice pretreated with BSF are expected to be a valuable platform not only for generating humanized mice but also for various immune research fields.

Exploring the Challenges of Distinguishing Punctate Inner Choroidopathy from Multifocal Choroiditis and Panuveitis.

PURPOSE: This retrospective case series aimed to assess the concordance between clinical diagnoses of punctate inner choroidopathy (PIC) and multifocal choroiditis and panuveitis (MCP) using the 2021 Standardization of Uveitis Nomenclature (SUN) Working Group criteria. METHODS: Using the medical records of the patients, we reevaluated 100 eyes of 75 patients with idiopathic multifocal chorioretinal inflammatory lesions based on SUN criteria and compared the result to the clinical diagnosis. RESULTS: Of 100 eyes, 29 eyes (29%) were diagnosed as PIC and 15 eyes (15%) were diagnosed as MCP using SUN criteria, and 56 (56%) eyes could not be diagnosed as either. Clinically diagnosed PIC eyes were significantly more myopic than the clinically diagnosed MCP eyes (mean spherical equivalent -6.65 ± 4.63 vs. -3.85 ± 2.31, P = 0.01). Sixteen eyes with vitreous inflammation were all clinically diagnosed as MCP, but four (25%) could not be diagnosed as MCP using SUN criteria. CONCLUSIONS: The existing diagnostic criteria showed limitations in capturing all clinical cases of PIC or MCP, and adding or revising criteria on features such as vitreous inflammation or myopia, could be considered to enhance diagnostic accuracy.

Prognostic Evaluation and Survival Prediction for Combined Hepatocellular-Cholangiocarcinoma Following Hepatectomy.

Purpose: This study aimed to assess prognostic factors associated with combined hepatocellular-cholangiocarcinoma (cHCC-CCA) and to predict 5-year survival based on these factors. Materials and Methods: Patients who underwent definitive hepatectomy from 2006 to 2022 at a single institution was retrospectively analyzed. Inclusion criteria involved a pathologically confirmed diagnosis of cHCC-CCA. Results: A total of 80 patients with diagnosed cHCC-CCA were included in the analysis. The median progression-free survival (PFS) was 15.6 months, while distant metastasis-free survival (DMFS), hepatic progression-free survival (HPFS), and overall survival (OS) were 50.8, 21.5, and 85.1 months, respectively. In 52 cases of recurrence, intrahepatic recurrence was the most common initial recurrence (34/52), with distant metastasis in 17 cases. Factors associated with poor DMFS included tumor necrosis, lymphovascular invasion (LVI), perineural invasion and histologic compact type. Postoperative CA19-9, tumor necrosis, LVI, and close/positive margin were associated with poor overall survival. LVI emerged as a key factor affecting both DMFS and OS, with a 5-year OS of 93.3% for patients without LVI compared to 35.8% with LVI. Based on these factors, a nomogram predicting 3-year and 5-year DMFS and OS was developed, demonstrating high concordance with actual survival in the cohort (Harrell C-index 0.809 for OS, 0.801 for DMFS, respectively). Conclusion: The prognosis of cHCC-CCA is notably poor when combined with lymphovascular invasion. Given the significant impact of adverse features, accurate outcome prediction is crucial. Moreover, consideration of adjuvant therapy may be warranted for patients exhibiting poor survival and increased risk of local recurrence or distant metastasis.

Piperacillin-Tazobactam versus Cefotaxime as Empiric Treatment for Febrile Urinary Tract Infection in Hospitalized Children.

BACKGROUND: According to international pediatric urinary tract infection (UTI) guidelines, selecting ampicillin/sulbactam or amoxicillin/clavulanate is recommended as the first-line treatment for pediatric UTI. In Korea, elevated resistance to ampicillin and ampicillin/sulbactam has resulted in the widespread use of third-generation cephalosporins for treating pediatric UTIs. This study aims to compare the efficacy of piperacillin-tazobactam (TZP) and cefotaxime (CTX) as first-line treatments in hospitalized children with UTIs. MATERIALS AND METHODS: The study, conducted at Jeju National University Hospital, retrospectively analyzed medical records of children hospitalized for febrile UTIs between 2014 and 2017. UTI diagnosis included unexplained fever, abnormal urinalysis, and the presence of significant uropathogens. Treatment responses, recurrence, and antimicrobial susceptibility were assessed. RESULTS: Out of 323 patients, 220 met the inclusion criteria. Demographics and clinical characteristics were similar between TZP and CTX groups. For children aged ≥3 months, no significant differences were found in treatment responses and recurrence. Extended-spectrum beta-lactamase (ESBL)-positive strains were associated with recurrence in those <3 months. CONCLUSION: In Korea, escalating resistance to empirical antibiotics has led to the adoption of broad-spectrum empirical treatment. TZP emerged as a viable alternative to CTX for hospitalized children aged ≥3 months with UTIs. Consideration of ESBL-positive strains and individualized approaches for those <3 months are crucial.

Impact of Complete Revascularization for Acute Myocardial Infarction In Multivessel Coronary Artery Disease Patients With Diabetes Mellitus.

BACKGROUND AND OBJECTIVES: The clinical benefits of complete revascularization (CR) in acute myocardial infarction (AMI) patients are unclear. Moreover, the benefit of CR is unknown in AMI with diabetes mellitus (DM) patients. We sought to compare the prognosis of CR and incomplete revascularization (IR) in patients with AMI and multivessel disease, according to the presence of DM. METHODS: A total of 2,150 AMI patients with multivessel coronary artery disease were analyzed. CR was defined based on the angiographic image. The primary endpoint of this study was the patient-oriented composite outcome (POCO) defined as a composite of all-cause death, any myocardial infarction, and any revascularization within 3 years. RESULTS: Overall, 3-year POCO was significantly lower in patients receiving angiographic CR (985 patients, 45.8%) compared with IR (1,165 patients, 54.2%). When divided into subgroups according to the presence of DM, CR reduced 3-year clinical outcomes in the non-DM group but not in the DM group (POCO: 11.7% vs. 23.2%, p<0.001, any revascularization: 7.2% vs. 10.8%, p=0.024 in the non-DM group, POCO: 24.3% vs. 27.8%, p=0.295, any revascularization: 13.3% vs. 11.3%, p=0.448 in the DM group, for CR vs. IR). Multivariate analysis showed that CR significantly reduced 3-year POCO (hazard ratio, 0.52; 95% confidence interval, 0.36-0.75) only in the non-DM group. CONCLUSIONS: In AMI patients with multivessel disease, CR may have less clinical benefit in DM patients than in non-DM patients.

Pachychoroid Spectrum Disease: Comparison of Patients with Central Serous Chorioretinopathy Complicated with Pachychoroid Neovasculopathy.

PURPOSE: This study aimed to determine the incidence and visual outcomes of pachychoroid neovasculopathy (PNV) in patients initially diagnosed with central serous chorioretinopathy (CSC). METHODS: In this study, 144 patients aged 20 to 55 years with treatment-naive chronic CSC, defined as the persistence of subretinal fluid (SRF) for ≥6 months, were retrospectively enrolled. Patients with PNV at the initial evaluation were categorized as group 1, whereas those who developed new-onset PNV during follow-up were categorized as group 2. Patients without PNV until the end of the follow-up were categorized as group 3. RESULTS: Over a mean follow-up period of 49.9 ± 39.9 months, new-onset PNV was diagnosed in 11.8% of patients with CSC. The time taken to reach the initial resolution was longest in group 1 (group 1, 11.13 ± 10.70 months; group 2, 8.14 ± 7.90 months; group 3, 7.32 ± 9.55 months), although these differences were not statistically significant. The numbers of injections needed to achieve initial resolution were 3.76 ± 5.90, 1.64 ± 2.06, and 1.74 ± 4.33 in groups 1, 2, and 3, respectively, with no significant differences. SRF recurrence was recorded in seven patients (29.2%) in group 1, nine (64.3%) in group 2, and 28 (26.7%) in group 3. The recurrence rates were significantly higher in group 2 than those in group 1 or 3. At the end of the follow-up period, significant improvements in best-corrected visual acuity were achieved in groups 1 and 3, compared with baseline, but not in group 2. CONCLUSIONS: Patients with chronic CSC with new-onset PNV exhibited higher SRF recurrence and worse visual outcomes compared to those with initial PNV or those with chronic CSC without PNV. Our study emphasizes the importance of routine screening for prompt diagnoses of new-onset PNV in individuals with chronic CSC.

Wavelength-dependent photobiomodulation (PBM) for proliferation and angiogenesis of melanoma tumor in vitro and in vivo.

Photobiomodulation (PBM) has widely been used to effectively treat complications associated with cancer treatment, including oral mucositis, radiation dermatitis, and surgical wounds. However, the safety of PBM against cancer still needs to be validated as the effects of PBM on cancer cells and their mechanisms are unclear. The current study investigated the wavelength-dependent PBM effects by examining four different laser wavelengths (405, 532, 635, and 808 nm) on B16F10 melanoma tumor cells. In vitro tests showed that PBM with 808 nm promoted both proliferation and migration of B16F10 cells. In vivo results demonstrated that PBM with 808 nm significantly increased the relative tumor volume and promoted angiogenesis with overexpression of VEGF and HIF-1α. In addition, PBM induced the phosphorylation of factors closely related to cancer cell proliferation and tumor growth and upregulated the related gene expression. The current result showed that compared to the other wavelengths, 808 nm yielded a significant tumor-stimulating effect the malignant melanoma cancer. Further studies will investigate the in-depth molecular mechanism of PBM on tumor stimulation in order to warrant the safety of PBM for clinical cancer treatment.