Search Results (66)

Harvesting of laver is an important link in the laver culture chain, and a new type of corrugated harvesting blade with a curved edge angle was designed to solve the problems of low cutting ratio in laver harvesting. The mechanical model of the corrugated blade cutting laver was established to elucidate the dynamic characteristics of laver cutting under single-point support. Based on the measured biomechanical characteristic parameters of Porphyra yezoensis, a rigid-flexible coupling model of laver harvesting was established based on ANSYS/LS-DYNA2022R2. The Box–Behnken design (BBD) test method was used to study the influence of the main structural parameters of the corrugated blade on the harvesting of laver, and the optimal structural parameter combinations of the corrugated blade were determined as follows: a slip angle of 21°, blade inclination angle of 106°, and curved edge angle of 15°; the slip-cutting mowing force of the laver was 11.18 N and the tensile force was 1.4 N. A bench test was completed, and the results showed that the corrugated blade could be used for harvesting laver. The results showed that the average loss rate of the harvesting equipment was 1.85% and the average net recovery rate was 98.75% when the corrugated blade rotational speed was 900 rpm and the boat speed was 0.71 m/s; compared to the traditional straight-blade hob-type harvesting machine, the cutting force on laver has increased by 45.26%, and the tensile force has decreased by 68.35%, which satisfied the requirements of laver harvesting. This study provides theoretical and simulation model references for the design, analysis, and optimization of laver harvesting equipment. Full article

This study was conducted to monitor 161 pesticides and 37 of their metabolites in cephalopods, crustaceans, seaweeds, and shellfish and to assess their potential risks. A total of 696 types of seafood (227 cephalopods, 56 crustaceans, 189 seaweeds, and 224 shellfish) were collected from local markets across the Republic of Korea and analyzed for pesticide residues using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Pesticide residues were detected only in shrimp among the crustaceans, whereas no residues were found in any species of cephalopods. Pesticide residues in shellfish were detected in abalone, clam, and marsh clam, while in seaweed, they were found in dried laver, dried sea lettuce, and fresh sea mustard. Among seafood products, seaweed had the highest pesticide detection rate of 8.5%, and the residue level of diuron—the most frequently detected insecticide in seaweed—was 0.05 mg/kg. The estimated daily intake (EDI) was calculated using the maximum pesticide concentration in crustaceans, shellfish, cephalopods, and seaweed, along with the seafood consumption by average and the 97.5th-percentile extreme consumers. The percentage of the acceptable daily intake (%ADI), calculated using the EDI and ADI of the pesticide detected, was evaluated to be less than 0.7% for all samples. The results suggest that the consumption of crustaceans, shellfish, cephalopods, and seaweed distributed in the Republic of Korea poses a low risk to human health. Full article

Background/Objectives: Seaweeds have recently gained global attention as sustainable and health-promoting food sources. However, seaweeds contain iodine. While iodine is a beneficial micronutrient, its excessive intake can pose health risks. Therefore, ensuring iodine safety has emerged as a critical priority. The present study aims to determine the total iodine content in five major edible seaweeds, namely laver (Porphyra spp.), sea mustard (Undaria pinnatifida), sea tangle (Saccharina japonica), green laver (Enteromorpha spp.), and hijiki (Hizikia fusiforme), collected from 12 coastal regions in South Korea during 2020–2024. Methods: A total of 348 samples were analyzed using inductively coupled plasma mass spectrometry following microwave-assisted digestion. A risk assessment was performed based on the estimated daily intake and hazard index (HI) using both the Korean Ministry of Food and Drug Safety (MFDS), EFSA (European Food Safety Authority), and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) reference values. Results: The iodine content varied widely among the different species, with sea tangles exhibiting the highest levels (mean 2432 mg/kg dry weight). The HI values were all below 1.0, based on MFDS standards, indicating a low potential health risk. However, sea tangle exhibited values exceeding 1.0 based on the EFSA and JECFA standards. Conclusions: These findings highlight the need for species-specific iodine intake guidelines and safety regulations to ensure consumer protection and facilitate global seaweed trade. The present study provides a scientific basis for balancing the nutritional benefits of seaweed with the potential risks of overconsumption, contributing to the development of national dietary guidelines and providing evidence-based data for navigating international regulatory landscapes. Full article

The development of antibacterial coatings for biomedical applications is crucial to prevent implant-associated infections (IAIs). In this study, we designed and evaluated a multilayer coating based on chitosan (CHI), polyacrylic acid (PAA), and triclosan (TCS) using the layer-by-layer (LbL) self-assembly technique. The successful incorporation of TCS was confirmed by Fourier-transform infrared (FTIR) spectroscopy. Surface roughness and topography were analyzed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Additionally, the pH-dependent behavior of PAA/CHI films was studied to assess its effect on TCS loading. According to disk diffusion assays, coatings assembled at pH 5 (PAA5/CHI5/TCS) exhibited the strongest antibacterial activity, with inhibition zones of 60.0 ± 0.0 mm for S. aureus and 33.67 ± 1.5 mm for E. coli. The long-term stability of the coatings was evaluated by measuring the antibacterial activity after 1, 10, 20, 30, and 40 days, with results confirming that antimicrobial properties and structural integrity were preserved over time. Furthermore, TCS release kinetics were assessed under physiological (pH 7.4) and acidic (pH 5.5) conditions, revealing enhanced release at pH 5.5. These findings highlight the potential of this multilayer system for biomedical applications requiring both stability and pH-responsive drug release. Full article

Background: Opioid dependence is prevalent among patients undergoing lumbar spinal fusion and has been linked to poor postoperative outcomes. However, its specific impact on surgical complications and hospital resource utilization remains unclear. This study evaluates the association between opioid dependence and postoperative complications, length of stay (LOS), and hospital charges in lumbar fusion patients. Methods: A retrospective analysis was conducted using the National Inpatient Sample (NIS) database from 2016 to 2021. Adult patients (aged > 18 years) who underwent lumbar fusion surgery were identified and categorized based on opioid dependence using ICD-10 codes. Propensity score weighting (PSW) was employed to balance baseline characteristics. Primary outcomes included inpatient mortality, LOS, hospital charges, and postoperative complications. Statistical analyses were performed using survey-weighted generalized linear models. Results: Among 597,455 lumbar fusion patients, 7715 (1.3%) had documented opioid dependence. After PSW, opioid-dependent patients had significantly increased odds of blood loss anemia (OR 1.79, p < 0.001), respiratory complications (OR 2.17, p < 0.001), surgical site infections (OR 3.94, p = 0.001), and cardiac complications (OR 1.53, p = 0.002). They also had higher hospital charges (mean difference USD 17,739.2, p < 0.001) and prolonged LOS (mean difference 0.83 days, p < 0.001). Differences in urinary tract infections, acute renal failure, and stroke were not statistically significant after PSW. Conclusions: Opioid dependence is associated with increased postoperative complications, longer hospital stays, and higher healthcare costs in lumbar fusion patients. These findings highlight the need for improved perioperative pain management and opioid stewardship strategies to optimize surgical outcomes. Full article

Many monitoring studies have been performed to assess and manage the risk of residues in seafood contaminated with pesticides owing to various environmental factors. Although seaweed and shellfish have higher consumption rates than fish, studies on their pesticide residues are limited. Therefore, this study aimed to conduct residue monitoring and a risk assessment of 51 pesticides in shellfish (littleneck clam and oyster) and seaweed (sea mustard, seaweed fusiforme, laver, and sea tangle) cultivated in four administrative regions of the Republic of Korea. A total of 120 samples (20 samples per species) were collected, and pesticide residues were analyzed using a modified Quick, Easy, Cheap, Effective, Rugged, and Safe extraction method, followed by a GC-MS/MS analysis. The monitoring results show that oxadiazon was detected at 8–9 ng/g in only four littleneck clam samples. The estimated daily intake was calculated and compared with the acceptable daily intake (ADI) for risk assessment. The %ADI values ranged from 0.05% to 1.12% for average and extreme consumers across six different scenarios. The results of this study suggest that the detected residual levels of pesticides exert no harmful effects on people over a lifetime of consumption. Full article

Background: End-stage ankle osteoarthritis (OA) severely limits function and quality of life. Total ankle arthroplasty (TAA) and ankle arthrodesis (AA) are key surgical interventions when conservative treatment fails. This study compares TAA and AA outcomes using a national dataset to inform patient-centered care. Methods: A retrospective analysis of 27,595 patients undergoing TAA or AA from 2016–2019 was conducted using the National Inpatient Sample. Propensity score matching addressed baseline differences. Results: Primary OA was more prevalent in TAA (85.9%) than in AA (55.4%). TAA utilization rose from 73% to 78% (p < 0.0001), while AA declined. TAA patients were older (65.6 vs. 59.7 years), more often Medicare-insured, and predominantly Caucasian. AA patients had higher rates of comorbidities, including diabetes, obesity, lung disease, and mental disorders (all p < 0.0001). Conclusions: TAA and AA cater to distinct patient profiles. TAA is increasingly favored and associated with lower immediate risks, though procedure choice should be individualized based on comorbidities and risk profiles. These insights support evidence-based decision-making in end-stage ankle OA management. Full article

Shinorine is a mycosporine-like amino acid isolated from laver (Porphyra dentata), and interest in its functionality has increased recently due to increased production using yeast. There have been few reports on the pharmacological activity of shinorine, and we sought to find the pharmacological significance of shinorine. In the present study, we investigated the pharmacological effects of shinorine purified from Porphyra dentata on ARPE-19 cells. First, when ARPE-19 cells were treated with bis-retinoid N-retinyl-N-retinylidene ethanolamine (A2E) and blue light (BL), cytotoxicity increased, and apoptosis was observed. We investigated the effects of shinorine on A2E- and BL-induced cytotoxicity and changes in apoptotic factors, inflammation, and carbonyl stress. A2E and BL exposure increased ARPE-19 cell apoptosis, but this increase was attenuated by shinorine in a concentration-dependent manner. Treatment with A2E and BL induced ARPE-19 cell apoptosis, but treatment with shinorine decreased the apoptotic factors, such as MAPKs. Shinorine reduced p-JNK and p-P38, which were increased by A2E and BL. In addition, shinorine was found to regulate inflammatory proteins and proteins associated with carbonyl stress. In conclusion, shinorine may suppress cell damage caused by A2E treatment and BL exposure at the cellular level by regulating various cell death and inflammatory response pathways. Full article

Sustainable seaweed cultivation is crucial for marine environmental protection, ecosystem health, socio-economic development, and carbon sequestration. Accurate and timely information on the distribution, extent, species, and production of cultivated seaweeds is essential for tracking biomass production, monitoring ecosystem health, assessing environmental impacts, optimizing cultivation planning, supporting investment decisions, and quantifying carbon sequestration potential. However, this important information is usually lacking. This study developed a high-precision monitoring approach by integrating Otsu thresholding features with random forest classification, implemented through Google Earth Engine using Sentinel-2 imagery (10-m). The method was applied to analyze spatiotemporal variations of seaweed cultivation across the Korean Peninsula from 2017 to 2023. Results showed that annual cultivation acreage in North Korea remained relatively stable between 1506 and 2033 ha, while it experienced a significant increase of 8209 ha in South Korea. By integrating spectral features, seaweed phenology, and field cultivation practices, we successfully differentiated the predominant species: laver (Pyropia) and kelp (Saccharina and Undaria). During the 2022–2023 cultivation season, South Korea’s farms comprised 78% laver and 22% kelp, while North Korea’s showed an inverse distribution. A strong correlation (r² = 0.99) between acreage and seaweed production enabled us to estimate annual seaweed production in North Korea, effectively addressing data gaps in regions with limited statistics. Our approach demonstrates the potential for global seaweed cultivation monitoring, while the spatial analysis lays the foundation for identifying potential cultivation zones. Given the relatively low initial investment requirement of seaweed farming and significant economic return, this approach offers valuable insights for promoting economic development and food security, ultimately supporting sustainable aquaculture management. Full article

Laver fluffy is an indispensable link in the processing of laver products. After fluffing, the laver acquires an appealing color, which is conducive to better marketability. During the primary mechanical processing of laver, a valve capable of rapid opening and closing is required to ensure that the laver’s surface becomes fluffy and lustrous post-processing. However, valve products that can meet the specific requirements of laver fluffing are scarce. This study proposes a novel principle for a high-speed switching control valve. This valve can quickly turn on or cut off the high-pressure gas path during laver processing while also taking into account the response speed and service life. The structure and principle of the new control valve were introduced. Different flow field models in the valve were designed, and their flow characteristics and flow field performance under various schemes were compared and discussed by using Fluent. Subsequently, an optimized control valve structure model was proposed. Based on this, a strength analysis of the control valve was conducted via fluid–structure interaction, revealing the response characteristics of the valve under the working state. The results indicate that, when different cone angles and bell shapes were selected for the upper chamber inlet of the control valve, the number and intensity of vortices in the upper chamber can be reduced. The height of the upper chamber affected the formation of the throttle between the top and bottom surfaces of the upper chamber. When the height of the upper chamber was 32 mm, the energy loss in the upper chamber remains basically stable. Simultaneously changing the inlet shape and height of the upper chamber can effectively prevent the throttle formed by the height of the upper chamber, which was conducive to increasing the valve outlet flow rate. Through the analysis of the flow field with different valve chamber structures, the improved control valve adopted the bell-shaped inlet, with an upper chamber height of 32 mm and curved transition for the internal flow channel. Compared to the original fluid domain, when the opening was 100%, the outlet flow rate of the 10° conical tube and bell-shaped inlet increased by 12.77% and 12.59%, respectively. The outlet flow rate at the curved transition position rose by 15.35%, and the outlet flow of the improved control valve increased by 32.70%. When the control valve was operating under a preload pressure of 1 MPa, at 20% opening, the maximum equivalent stress of the valve body was 52.51 MPa, and the total deformation was 12.56 microns. When the preload pressure exceeded 1.5 MPa, the equivalent stress and total deformation of the control valve body and T-shaped valve stem exhibited an upward trend with further increases in the preload pressure. Full article

Background: Total elbow arthroplasty (TEA) was initially introduced for end-stage rheumatoid arthritis but has since expanded to include osteoarthritis and complex distal humerus fractures, particularly in elderly patients. Over the past two decades, TEA utilization trends have fluctuated, with a recent decline attributed to advancements in disease-modifying antirheumatic drugs. Despite its benefits, TEA presents a high complication rate, necessitating further investigation into clinical outcomes, costs, and postoperative management. Methods: This retrospective cohort study analyzed TEA procedures from 2016 to 2019 using the National Inpatient Sample (NIS) database. Patients were identified via ICD-10 codes, with elective procedures included to ensure homogeneity. This study examined temporal trends, patient demographics, comorbidities, complication rates, length of stay (LOS), and hospitalization costs. Statistical analyses included chi-square tests, t-tests, and multivariate regression to assess associations between patient characteristics and outcomes. Results: A total of 4110 TEA procedures were analyzed, revealing a 16% decline in annual volume from 2016 to 2019 (p = 0.012). The cohort had a mean age of 65.99 years, with a predominance of female (75.3%) and White (72.6%) patients. The median LOS was two days, and median hospitalization costs were USD 78,473 (IQR: 56,935–115,671 USD). The most prevalent complications included mechanical loosening (12.5%), blood loss anemia (10.6%), cardiac complications (5.7%), and prosthetic-related pain (3.3%). Multivariate analysis identified hypertension, anemia, and respiratory disease as significant predictors of adverse outcomes. Conclusions: TEA utilization has declined, likely due to medical advancements in rheumatoid arthritis management. The procedure remains associated with substantial complication rates, particularly in trauma-related cases. Findings highlight the importance of patient optimization, surgical expertise, and postoperative monitoring to improve outcomes. Full article

Laver (Pyropia spp.) is a major seaweed that is cultivated and consumed globally. Although quality standards for laver products have been established, traditional physicochemical analyses and sensory evaluations have notable drawbacks regarding rapid-quality inspection. Not all relevant physicochemical quality indices, such as texture, are typically evaluated. Therefore, in this study, we investigated the use of hyperspectral imaging to rapidly, accurately, and objectively determine the quality of dried laver. Hyperspectral images of 25 dried laver samples were captured in the short-wave infrared range from 980 to 2576 nm to assess their moisture, protein content, cutting stress, and other key quality indicators. Spectral signatures were analyzed using partial least-squares discriminant analysis (PLS-DA) to correlate the spectral data with three primary quality index values. The performance of PLS-DA was compared with that of the variable importance in projection score and nonlinear regression analysis methods. The comprehensive quality grading model demonstrated accuracies ranging from 96 to 100%, R² values from 75 to 92%, and root-mean-square errors from 0.14 to 0.25. These results suggest that the PLS-DA regression model shows great potential for the multivariate analysis of hyperspectral images, serving as an effective quality grading system for dried laver. Full article

To understand better the high microbial load in dried laver (Porphyra yezoensis or nori), this study analyzed the aerobic plate count (APC), coliform count, temperature change, and microbiota of processing water, laver materials, and food contact surface (FCS) samples from three processing plants during the dried laver processing season from December 2023 to April 2024. The seawater used for the first washing had a low microbial load (APCs < 1–2.85 log CFU/g; coliform < 1 log CFU/g) and was dominated by Proteobacteria, Firmicutes, and Bacteroidota. The microbial load of fresh laver (4.21–4.76 log CFU/g) remained unchanged after seawater washing, but significantly increased after continuous shredding, sponge dehydration, first drying, and with the seasonal temperature rise. The microbiota of laver before drying was vulnerable between processing steps and seasons, but consistently shifted back to fresh laver microflora and was dominated by Flavobacteriaceae after drying. The FCSs (except for the curtain), which had a high microbial load (APCs 5.25–8.26 log CFU/g; coliform 1.52–4.84 log CFU/g) with similar microbiota to seawater, caused the secondary contamination of laver during processing. This study revealed the microbial proliferation of laver and seawater microflora in the continuous processing line with high nutrients and with the seasonal processing water temperature rise caused by the local weather, highlighting the need for routine cleaning and sanitizing, better washing of fresh laver, and low temperature control for future dried laver production. Full article

This study analyzed 192 samples of Porphyra dentata (P-dent) and 201 samples of Porphyra yezoensis (P-yezo) from Jeonnam in Korea. Principal component analysis (PCA) and correlation analysis were conducted to establish a nutritional component dataset for laver. The analysis revealed that P-dent had higher moisture and weight but lower protein content than P-yezo. Ca, Mg, and Fe levels were higher in P-dent, while P, Na, and Zn levels were higher in P-yezo. Fatty acids composition analysis indicated that P-dent contained higher levels of linoleic acid, while P-yezo exhibited higher levels of oleic acid and eicosapentaenoic acid (EPA). P-yezo had significantly higher levels of chlorophyll and carotenoids compared to P-dent. Conversely, P-dent exhibited higher L* and b* color values, resulting in a brighter, more yellowish appearance. Sensory analysis indicated that P-yezo was more intense in saltiness and umami, whereas P-dent had higher sourness and sweetness. The principal component analysis (PCA) results showed a clear distinction between P-dent and P-yezo, and 184 correlations among factors (nutrients, characteristics, etc.) were identified. These results contribute to a new database for evaluating the quality of Jeonnam laver. Full article

The optimum processing conditions for green laver chips were determined using response surface methodology (RSM) to improve taste and reduce off-flavors by applying reaction flavor and air-frying techniques. The optimum composition (w/w) for the chips included 20% green laver, 20% hairtail surimi, and 60% flour. Additional ingredients included distilled water (90 mL) with GDL (3 g), NaHCO₃ (2 g), salt (1 g), sugar (12 g), roasted soybean powder (1.5 g), and reaction flavor solution (RFS, 10 mL). The mixture was kneaded, shaped, dried at 50 °C for 2 h, and air-fried at 195 °C for 80 sec. The resulting green laver chips showed overall acceptance and brittleness values of 7.00 ± 0.74 and 5.89 ± 0.59 N, respectively, with absolute residual errors of 8.43% and 7.07%. The optimum reaction flavor precursors for green laver chips were determined to be threonine (1.0 g%), proline (1.0 g%), glycine (1.4 g%), methionine (0.05 g%), and glucose (2 g%). Flavor analysis revealed that green laver chips with reaction flavor (GLCR) contained 13 alkylpyrazines with corn-like and nutty odors, and 2-acetylpyrrole, which contributed a popcorn-like odor. In contrast, green laver chips without reaction flavor (GLC) predominantly contained straight-chain aldehydes with undesirable odors. The heating process in the air fryer appeared to reduce the aldehyde content and promote pyrazine formation, significantly enhancing GLCR’s flavor. Full article