Effects of body mass index on mortality in elderly patients with hip fractures.

Hip fractures remain a substantial health concern, particularly among elderly individuals with osteoporosis, leading to high global mortality rates. This study aimed to analyze the association between body mass index (BMI) and postoperative mortality in patients who underwent surgery for hip fractures. A total of 680 patients treated at a single institution between January 2018 and December 2022 were included. Factors such as age, BMI, sex, Charlson Comorbidity Index (CCI), preoperative hemoglobin levels, American Society of Anesthesiologists score, anesthesia method, duration of surgery, and time from injury to surgery were assessed. Underweight status, male sex, higher CCI, and general anesthesia were significantly associated with 1-year and in-hospital mortality. Notably, underweight individuals exhibited a higher risk of mortality than normal-weight individuals, and female patients had lower mortality rates. This study underscores the importance of considering BMI, along with other demographic and clinical factors, in predicting postoperative mortality among patients with hip fractures, aiding the development of tailored management strategies to improve outcomes and reduce complications in this vulnerable patient population.

Role of induction chemotherapy in advanced-stage olfactory neuroblastoma.

OBJECTIVES: To evaluate the treatment outcomes in patients with advanced-stage olfactory neuroblastoma (ONB) who received induction chemotherapy (IC). MATERIALS AND METHODS: The clinical data of 38 patients with advanced-stage ONB who received initial IC were retrospectively analyzed. The response was defined using the Response Evaluation Criteria in Solid Tumors version 1.1. Patients with complete remission or partial remission were defined as responders. RESULTS: Seventeen (44.7%) patients responded to IC. The response rate was higher in patients with high Hyams grade tumor (III/IV) compared to those with low-grade tumors (I/II) (60% vs. 22.2%, p = 0.038). Overall, the 5-year cancer-specific survival (CSS) rate was 76.0%. Among nonresponders to IC, a significant difference in 5-year CSS rates was observed between surgery with adjuvant radiotherapy (RT) (100%) versus definitive RT or chemoradiotherapy (CRT) (68.6%) (log-rank p = 0.006). However, for responders, there was no significant difference in 5-year CSS rates between surgery with adjuvant therapy (75%) and definitive RT or CRT (51.1%) (log-rank p = 0.536). When only high-grade tumors were considered among responders, the 5-year CSS rate was significantly higher in patients who received RT or CRT (51.4%) compared to those who underwent surgery with adjuvant therapy (0%) (log-rank p = 0.008). CONCLUSION: In advanced-stage ONB, RT or CRT may be preferable for high-grade tumor responding to IC. Higher response rate and a potential role for induction IC in determining the optimal definitive treatment modality suggest a positive role for advanced-stage high-grade ONB.

Spatiotemporal variation of sterols in sediment as markers of primary production and ocean sewage dumping in the southwestern East Sea (Japan Sea).

The sedimentation of organic carbon in the Ulleung Basin, in the southwestern East Sea (Japan Sea) was investigated using radiocarbon and sterols. The accumulation rates of organic carbon and the contents of brassicasterol and dinosterol were higher on the slope than in the central basin, reflecting the surface water productivity, whereas cholesterol showed similar or higher contents in the central basin. The coprostanol concentration in surface sediments reflected the dispersion of sewage dumped in this region. The vertical distribution showed that the coprostanol concentration was the highest in the top 5-cm layer near the Korea Strait, close to one of the two dumping sites. A high coprostanol concentration was also found near the coast further north, where the content peaked at ∼10 cm depth. The vertical distribution of coprostanol helped to estimate the sediment accumulation rate at sites where radiocarbon gradient was too small or the values were too variable.

The Search for an Ideal Definitive Treatment of Sinonasal Squamous Cell Carcinoma With Orbit Invasion.

OBJECTIVES: Sinonasal squamous cell carcinoma (SqCC) often invades the orbit. The treatment approach for sinonasal cancer that has spread to the orbit varies across medical centers and depends on the extent of the invasion. The decision to preserve the orbit in the treatment strategy is made on a case-by-case basis and. RESULTS: in varying outcomes. Currently, a multimodal treatment regimen, which may include surgery, chemotherapy, radiotherapy (RT), or concurrent chemoradiotherapy (CCRT), is commonly adopted for managing sinonasal cancers. This study aims to assess the prognosis of sinonasal SqCC with orbital invasion from various perspectives. METHODS: We conducted a retrospective review of patients with primary sinonasal SqCC invading the orbit who were treated at Seoul National University Hospital and Seoul National University Bundang Hospital between 2009 and 2018. The extent of the tumor, orbital invasion, treatment strategies, recurrence rates, and survival rates were analyzed. RESULTS: Overall survival and disease-free survival (DFS) rates showed no significant differences based on the grade of orbital invasion. When tumor resection with orbit preservation was employed as the definitive treatment, DFS was significantly extended compared to cases where surgery was not the definitive treatment (RT or CCRT). Additionally, there was no significant difference in DFS between patients who underwent orbit exenteration and those who underwent tumor resection with orbit preservation as the definitive treatment. CONCLUSION: Tumor resection with orbit preservation as the definitive treatment appears to be the preferred approach, prolonging DFS and increasing the likelihood of longer-term survival in cases of SqCC with orbital invasion.

Comparison of early visual outcomes after SMILE using VISUMAX 800 and VISUMAX 500 for myopia: a retrospective matched case-control study.

VISUMAX 800 was introduced to improve the patient experience and clinical outcomes of small incision lenticule extraction (SMILE). This was a retrospective, matched, and case-control study (1:2) controlled for preoperative central corneal thickness and refractive error that compared early refractive and visual outcomes after SMILE using VISUMAX 800 and VISUMAX 500 to treat myopia. We included 50 eyes that underwent the VISUMAX 800 SMILE and 100 eyes that underwent the VISUMAX 500 SMILE. SMILE using VISUMAX 800 was performed using the CentraLign aid for vertex centration. Cyclotorsion was controlled by an OcuLign assistant in the VISUMAX 800 group after corneal marking. Corneal higher-order aberrations (HOAs) were evaluated using a Pentacam 1 month after surgery. No differences were observed in the pre- and post-operative refractive and visual outcomes at 1 day, 1 month, and 6 months after surgery. VISUMAX 800 induced less total HOAs than VISUMAX 500 (P = 0.036). No statistically significant differences were observed in the amounts of induced spherical aberrations or vertical and horizontal comas. No differences were observed in the 1 month and 6 months refractive and visual outcomes between two SMILE procedures, except for VISUMAX 800, which resulted in lower postoperative total HOAs than VISUMAX 500.

Code-Free Machine Learning Approach for EVO-ICL Vault Prediction: A Retrospective Two-Center Study.

Purpose: Establishing a development environment for machine learning is difficult for medical researchers because learning to code is a major barrier. This study aimed to improve the accuracy of a postoperative vault value prediction model for implantable collamer lens (ICL) sizing using machine learning without coding experience. Methods: We used Orange data mining, a recently developed open-source, code-free machine learning tool. This study included eye-pair data from 294 patients from the B&VIIT Eye Center and 26 patients from Kim's Eye Hospital. The model was developed using OCULUS Pentacam data from the B&VIIT Eye Center and was internally evaluated through 10-fold cross-validation. External validation was performed using data from Kim's Eye Hospital. Results: The machine learning model was successfully trained using the data collected without coding. The random forest showed mean absolute errors of 124.8 µm and 152.4 µm for the internal 10-fold cross-validation and the external validation, respectively. For high vault prediction (>750 µm), the random forest showed areas under the curve of 0.725 and 0.760 for the internal and external validation datasets, respectively. The developed model performed better than the classic statistical regression models and the Google no-code platform. Conclusions: Applying a no-code machine learning tool to our ICL implantation datasets showed a more accurate prediction of the postoperative vault than the classic regression and Google no-code models. Translational Relevance: Because of significant bias in measurements and surgery between clinics, the no-code development of a customized machine learning nomogram will improve the accuracy of ICL implantation.

Phosphorus-Ligand Redox Cooperative Catalysis: Unraveling Four-Electron Dioxygen Reduction Pathways and Reactive Intermediates.

The reduction of dioxygen to water is crucial in biology and energy technologies, but it is challenging due to the inertness of triplet oxygen and complex mechanisms. Nature leverages high-spin transition metal complexes for this, whereas main-group compounds with their singlet state and limited redox capabilities exhibit subdued reactivity. We present a novel phosphorus complex capable of four-electron dioxygen reduction, facilitated by unique phosphorus-ligand redox cooperativity. Spectroscopic and computational investigations attribute this cooperative reactivity to the unique electronic structure arising from the geometry of the phosphorus complex bestowed by the ligand. Mechanistic study via spectroscopic and kinetic experiments revealed the involvement of elusive phosphorus intermediates resembling those in metalloenzymes. Our result highlights the multielectron reactivity of phosphorus compound emerging from a carefully designed ligand platform with redox cooperativity. We anticipate that the work described expands the strategies in developing main-group catalytic reactions, especially in small molecule fixations demanding multielectron redox processes.

Deep learning algorithm for the automated detection and classification of nasal cavity mass in nasal endoscopic images.

Nasal endoscopy is routinely performed to distinguish the pathological types of masses. There is a lack of studies on deep learning algorithms for discriminating a wide range of endoscopic nasal cavity mass lesions. Therefore, we aimed to develop an endoscopic-examination-based deep learning model to detect and classify nasal cavity mass lesions, including nasal polyps (NPs), benign tumors, and malignant tumors. The clinical feasibility of the model was evaluated by comparing the results to those of manual assessment. Biopsy-confirmed nasal endoscopic images were obtained from 17 hospitals in South Korea. Here, 400 images were used for the test set. The training and validation datasets consisted of 149,043 normal nasal cavity, 311,043 NP, 9,271 benign tumor, and 5,323 malignant tumor lesion images. The proposed Xception architecture achieved an overall accuracy of 0.792 with the following class accuracies on the test set: normal = 0.978 ± 0.016, NP = 0.790 ± 0.016, benign = 0.708 ± 0.100, and malignant = 0.698 ± 0.116. With an average area under the receiver operating characteristic curve (AUC) of 0.947, the AUC values and F1 score were highest in the order of normal, NP, malignant tumor, and benign tumor classes. The classification performances of the proposed model were comparable with those of manual assessment in the normal and NP classes. The proposed model outperformed manual assessment in the benign and malignant tumor classes (sensitivities of 0.708 ± 0.100 vs. 0.549 ± 0.172, 0.698 ± 0.116 vs. 0.518 ± 0.153, respectively). In urgent (malignant) versus nonurgent binary predictions, the deep learning model achieved superior diagnostic accuracy. The developed model based on endoscopic images achieved satisfactory performance in classifying four classes of nasal cavity mass lesions, namely normal, NP, benign tumor, and malignant tumor. The developed model can therefore be used to screen nasal cavity lesions accurately and rapidly.

Treatment outcome and prognostic factors of inverted papilloma involving the frontal sinus.

Objectives: This study aimed to evaluate the characteristics and treatment outcomes of inverted papillomas involving the frontal sinus. Methods: Patients treated for inverted papilloma involving the frontal sinus between 2003 and 2020 were reviewed. Tumors were classified based on their extent (Extent 1: partially encroaching on the frontal sinus; Extent 2: completely filling the frontal sinus; Extent 3: eroding bony borders beyond the frontal sinus) and site of origin (Origin 1: originating outside the frontal sinus and prolapsing into the frontal sinus; Origin 2: originating from the frontal sinus walls medial to the vertical plane of the lamina papyracea; Origin 3: originating from the frontal sinus walls lateral to the vertical plane of the lamina papyracea). Treatment outcomes including tumor recurrence and patency of the frontal recess were analyzed according to tumor characteristics and surgical treatment modalities. Results: A total of 49 surgical cases were analyzed. Extent 1 were the most common type (n = 27), followed by Extent 2 (n = 15), and Extent 3 (n = 7). The most common sites of origin were Origin 1 (n = 23), followed by Origin 2 (n = 15), and Origin 3 (n = 11). Overall, there were nine recurrences (18.4%). Recurrence was not associated with tumor extent, whereas tumor origin, particularly Origin 3 was associated with higher recurrence; 1/23 (4.3%) for Origin 1, 3/15 (20.0%) for Origin 2, and 5/11 (45.5%) for Origin 3 (Log-rank p < .001). Draf III frontal sinusotomy was associated with in the highest patency rate (84.6%) during the follow-up. Conclusion: The recurrence rate of frontal sinus inverted papilloma depends on tumor origin rather than the extent of the tumor. In particular, lesions originating from the frontal sinus lateral to the lamina papyracea recur frequently. Draf III frontal sinusotomy can achieve patent frontal recess allowing active surveillance. Level of Evidence: IV.

Trophic assessment of red seabream (Pagrus major) as a possible bioindicator of human activities in the South Sea of Korea using stable C and N isotopes.

To assess the impact of sand mining on resource utilization by the red seabream (Pagrus major) and the trophic structure of fish assemblages two years after mining activities, we compared stable isotope ratios (δ13C and δ15N) and isotopic niches between aggregated mining and control sites in April and August 2022. Our results showed no spatial differences in the δ13C and δ15N values of red seabream between the sand mining and control sites, suggesting that the mining did not affect their dietary resources. Furthermore, the considerable overlap among fish consumers suggested that the fish food web in mining areas has trophic functions similar to those in natural habitats after mining activities. Overall, our study enhances our understanding of ecosystem conservation and the ecological-based management of coastal areas.

Treatment Outcomes of Olfactory Neuroblastoma: A Multicenter Study by the Korean Sinonasal Tumor and Skull Base Surgery Study Group.

OBJECTIVES: Due to the rarity of olfactory neuroblastoma (ONB), there is ongoing debate about optimal treatment strategies, especially for early-stage or locally advanced cases. Therefore, our study aimed to explore experiences from multiple centers to identify factors that influence the oncological outcomes of ONB. METHODS: We retrospectively analyzed 195 ONB patients treated at nine tertiary hospitals in South Korea between December 1992 and December 2019. Kaplan-Meier survival analysis was used to evaluate oncological outcomes, and a Cox proportional hazards regression model was employed to analyze prognostic factors for survival outcomes. Furthermore, we conducted 1:1 nearest-neighbor matching to investigate differences in clinical outcomes according to the use of neoadjuvant chemotherapy. RESULTS: In our cohort, the 5-year overall survival (OS) rate was 78.6%, and the 5-year disease-free survival (DFS) rate was 62.4%. The Cox proportional hazards model revealed that the modified Kadish (mKadish) stage and Dulguerov T status were significantly associated with DFS, while the mKadish stage and Hyams grade were identified as prognostic factors for OS. The subgroup analyses indicated a trend toward improved 5-year DFS with dural resection in mKadish A and B cases, even though the result was statistically insignificant. Induction chemotherapy did not provide a survival benefit in this study after matching for the mKadish stage and nodal status. CONCLUSION: Clinical staging and pathologic grading are important prognostic factors in ONB. Dural resection in mKadish A and B did not show a significant survival benefit. Similarly, induction chemotherapy also did not show a survival benefit, even after stage matching.

Molecular and Treatment Characteristics of SMARCB1 or SMARCA4-Deficient Undifferentiated Tumor: Retrospective Case Series.

SMARCB1 or SMARCA4-deficient sinonasal carcinoma or thoracic undifferentiated tumor has aggressive nature with a poor prognosis. Patients with this disease were diagnosed by immunohistochemistry or next-generation sequencing. Those who were able to receive a surgery tended to be cured, while the others treated with chemotherapy, radiation therapy, or immune checkpoint inhibitor were often insensitive to these therapies. However, one having CD274 (PD-L1) amplification showed the response to immune checkpoint inhibitor and a good prognosis. We believed that this report could provide promising information for determining the optimal treatment option.

Development of a Machine-Learning-Based Tool for Overnight Orthokeratology Lens Fitting.

Purpose: Orthokeratology (ortho-K) is widely used to control myopia. Overnight ortho-K lens fitting with the selection of appropriate parameters is an important technique for achieving successful reductions in myopic refractive error. In this study, we developed a machine-learning model that could select ortho-K lens parameters at an expert level. Methods: Machine-learning models were established to predict the optimal ortho-K parameters, including toric lens option (toric or non-toric), overall diameter (OAD; 10.5 or 11.0 mm), base curve (BC), return zone depth (RZD), landing zone angle (LZA), and lens sagittal depth (LensSag). The analysis included 547 eyes of 297 Korean adolescents with myopia or astigmatism. The dataset was randomly divided into training (80%, n = 437 eyes) and validation (20%, n = 110 eyes) sets at the patient level. The model was trained based on clinical ortho-K lens fitting performed by highly experienced experts and ophthalmic measurements. Results: The final machine-learning models showed accuracies of 92.7% and 86.4% for predicting the toric lens option and OAD, respectively. The mean absolute errors for the BC, RZD, LZA, and LensSag predictions were 0.052 mm, 2.727 µm, 0.118°, and 5.215 µm, respectively. The machine-learning model outperformed the manufacturer's conventional initial lens selector in predicting BC and RZD. Conclusions: We developed an expert-level machine-learning-based model for determining comprehensive ortho-K lens parameters. We also created a web-based application. Translational Relevance: This model may provide more accurate fitting parameters for lenses than those of conventional calculations, thus reducing the need to rely on trial and error.

Innate Immune Training Initiates Efferocytosis to Protect against Lung Injury.

Innate immune training involves myelopoiesis, dynamic gene modulation, and functional reprogramming of myeloid cells in response to secondary heterologous challenges. The present study evaluates whether systemic innate immune training can protect tissues from local injury. Systemic pretreatment of mice with ß-glucan, a trained immunity agonist, reduces the mortality rate of mice with bleomycin-induced lung injury and fibrosis, as well as decreasing collagen deposition in the lungs. ß-Glucan pretreatment induces neutrophil accumulation in the lungs and enhances efferocytosis. Training of mice with ß-glucan results in histone modification in both alveolar macrophages (AMs) and neighboring lung epithelial cells. Training also increases the production of RvD1 and soluble mediators by AMs and efferocytes. Efferocytosis increases trained immunity in AMs by stimulating RvD1 release, thus inducing SIRT1 expression in neighboring lung epithelial cells. Elevated epithelial SIRT1 expression is associated with decreased epithelial cell apoptosis after lung injury, attenuating tissue damage. Further, neutrophil depletion dampens the effects of ß-glucan on macrophage accumulation, epigenetic modification in lung macrophages, epithelial SIRT1 expression, and injury-mediated fibrosis in the lung. These findings provide mechanistic insights into innate immune training and clues to the potential ability of centrally trained immunity to protect peripheral organs against injury-mediated disorders.

Spatial and temporal variations in trophic structure of fish assemblages in the Yellow Sea revealed by C and N stable isotopes.

In this study, we assessed spatial and temporal variations in the trophic structure of fish assemblages in the Yellow Sea during spring and summer 2022 and compared their isotopic niches between the Provisional Measure Zone (PMZ) and Korea's west areas (non-PMZ) within the Yellow Sea. Spatial and temporal differences in the diversity and dominant species of fish assemblages were found between the PMZ and non-PMZ areas between the seasons. The mean δ13C values of fish assemblages were relatively higher in the non-PMZ areas than in the PMZ areas. In contrast, no significant differences were found in the mean δ15N values between the areas. Generally, the isotopic niche indices were relatively narrow in the PMZ areas compared to those in the non-PMZ areas. Overall, these spatial differences between the PMZ and non-PMZ areas suggest different trophic diversity of fish assemblages, resulting from site-specific variations in environmental conditions and community composition.

Implications for Combination Therapy of Selective Monoamine Reuptake Inhibitors on Dopamine Transporters.

Monoamine transporters, including dopamine, norepinephrine, and serotonin transporters (DAT, NET, and SERT, respectively), are important therapeutic targets due to their essential roles in the brain. To overcome the slow action of selective monoamine reuptake inhibitors, dual- or triple-acting inhibitors have been developed. Here, to examine whether combination treatments of selective reuptake inhibitors have synergistic effects, the pharmacological properties of DAT, NET, and SERT were investigated using the selective inhibitors of each transporter, which are vanoxerine, nisoxetine, and fluoxetine, respectively. Potencies were determined via fluorescence-based substrate uptake assays in the absence and presence of other inhibitors to test the multi-drug effects on individual transporters, resulting in antagonistic effects on DAT. In detail, fluoxetine resulted in a 1.6-fold increased IC50 value of vanoxerine for DAT, and nisoxetine produced a more drastic increase in the IC50 value by six folds. Furthermore, the effects of different inhibitors, specifically monovalent ions, were tested on DAT inhibition by vanoxerine. Interestingly, these ions also reduced vanoxerine potency in a similar manner. The homology models of DAT suggested a potential secondary inhibitor binding site that affects inhibition in an allosteric manner. These findings imply that the use of combination therapy with monoamine reuptake inhibitors should be approached cautiously, as antagonistic effects may occur.

Standardized image-based polysomnography database and deep learning algorithm for sleep-stage classification.

STUDY OBJECTIVES: Polysomnography (PSG) scoring is labor-intensive, subjective, and often ambiguous. Recently several deep learning (DL) models for automated sleep scoring have been developed, they are tied to a fixed amount of input channels and resolution. In this study, we constructed a standardized image-based PSG dataset in order to overcome the heterogeneity of raw signal data obtained from various PSG devices and various sleep laboratory environments. METHODS: All individually exported European data format files containing raw signals were converted into images with an annotation file, which contained the demographics, diagnoses, and sleep statistics. An image-based DL model for automatic sleep staging was developed, compared with a signal-based model, and validated in an external dataset. RESULTS: We constructed 10253 image-based PSG datasets using a standardized format. Among these, 7745 diagnostic PSG data were used to develop our DL model. The DL model using the image dataset showed similar performance to the signal-based dataset for the same subject. The overall DL accuracy was greater than 80%, even with severe obstructive sleep apnea. Moreover, for the first time, we showed explainable DL in the field of sleep medicine as visualized key inference regions using Eigen-class activation maps. Furthermore, when a DL model for sleep scoring performs external validation, we achieved a relatively good performance. CONCLUSIONS: Our main contribution demonstrates the availability of a standardized image-based dataset, and highlights that changing the data sampling rate or number of sensors may not require retraining, although performance decreases slightly as the number of sensors decreases.

Trophic response of fishes to rainfall variability in a temperate estuarine system of Korea: A stable isotope approach.

To assess the basal resources supporting food webs impacted by rainfalls, we compared stable isotope ratios (δ13C and δ15N) of fish consumers and organic matter sources between up- and down-sites in an estuary between seasons (June and September) and years (2018 and 2019) that showed different patterns of summer monsoon. Our study showed seasonal differences in the δ13C and δ15N values of basal resources and fish consumers in both years. At the up-site, significant differences of δ13C values of fish consumers were found between years, resulting from changing rainfall period, thereby causing a shift in food availability from terrigenous organic matter to periphyton. In contrast, at the down-site, the consistent isotopic values of fishes were observed in both years, suggesting that rainfall shift has a negligible impact on resources for fishes. Overall, the annual shift in resources for fishes in the estuary may be controlled by contrasting rainfall events.

Factors affecting the willingness to pay extra for safe food.

BACKGROUND/OBJECTIVES: With the outbreak of infectious diseases, such as coronavirus disease 2019 (COVID-19), public interest in health and safety has increased, and consequently, interests in food safety have been heightened too. The purpose of this study was to compare and analyze the involvement of various categories of consumers in food safety, the subjective evaluation of food safety in Korea, and the willingness of the consumers to pay extra for safe food according to their demographic and socioeconomic characteristics. MATERIALS/METHODS: This study used data from the 2020 Consumer Behavior Survey for Food provided by the Korea Rural Economic Institute (KREI). The subjects were 6,355 adult household members aged 19 to 75 years old. The survey was conducted from June 10th to August 21st, 2020. The data for the study were subjected to statistical analyses, including descriptive statistics, complex sample general linear model, k-means cluster, and multiple regression analyses. RESULTS: The factors affecting the willingness to pay extra for safe food were education level, occupation, monthly household income, presence of a young (teenager) household member, and the subjects' involvement in food safety. the significant factors affecting the willingness to pay extra for safe food were sex, age, and income level for the group exhibiting a low level of involvement in food safety, while education level and presence of a young household member were the statistically significant factors for the group exhibiting a high level of involvement in food safety. CONCLUSION: This study verified the differences in the factors associated with the willingness to pay extra for safe food according to the demographic and socioeconomic characteristics, involvement in food safety, subjective evaluation of food safety. This study offers practical implications to the industry and government that would help in directing strategies to strengthen safe food management.

Estuarine dam water discharge enhances summertime primary productivity near the southwestern Korean coast.

The gate opening of estuarine dams discharge a large amount of freshwater into coastal zones during the summer monsoon in northeast Asia. We investigated seasonal and spatial variations in primary productivity (PP) and community structures of phytoplankton on a downstream macrotidal flat and examined the dam discharge effects. Our harmonic analysis of the PP revealed a clear seasonality with a unimodal peak in summer, possibly driven by high ammonium loading through internal recycling. External nitrate supply from the dam-water discharge promoted PP during July-August, generating conspicuous blooms near the discharging site. Phytoplankton community was characterized by a predominance of diatoms all year round and seasonal dominances from dinoflagellates, cryptophytes, and prasinophytes in spring to chlorophytes in summer, reflecting spatiotemporal patterns in ammonium and nitrate supply. Our findings provide new insights into the summer phytoplankton bloom linked to monsoonal rainfall in the shallow coastal seas along the Northeast Asian coast.