Modified EASIX scores predict severe CRS/ICANS in patients with acute myeloid leukemia following CLL1 CAR-T cell therapy.

Chimeric antigen receptor T (CAR-T) cell therapy targeting CLL1 has been considered a potent weapon for patients with acute myeloid leukemia (AML). This study aims to evaluate the efficacy and toxicity of CLL1 CAR-T cell therapy in a larger cohort, with particular attention to cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Among the 32 patients assessed for efficacy, complete remission occurred in 71.88% (23/32) of cases and undetectable minimal residual disease in 14 patients. The CRS developed in all patients, with 8 individuals experiencing ICANS. Severe CRS and ICANS were observed in 11 and 2 patients, respectively. Furthermore, the Endothelial Activation and Stress Index (EASIX) and its derivatives measured before and after CLL1 CAR-T cell infusion were employed for predicting the severe complications. Significant differences were observed in EASIX scores on the day before lymphodepletion (Day BL, P = 0.023), -1 (P < 0.001), +1 (P < 0.001), and +3(P = 0.014); sEASIX scores on Day BL (P = 0.007), -1 (P < 0.001), +1 (P < 0.001), and +3 (P < 0.001); and mEASIX score on Day -1 (P = 0.004) between patients with mild and severe CRS/ICANS. Additionally, there was a significant difference in mEASIX scores between responders and non-responders on Day BL (P = 0.004) and Day -1 (P = 0.044). Our findings indicate that pre- and post-infusion assessments of EASIX/mEASIX/sEASIX scores serve as reliable prognostic indicators for severe CRS/ICANS and treatment response following CLL1 CAR-T cell therapy, which can assist physicians in implementing preemptive treatment strategies for potential severe complications and screening patients who are suitable candidates for CLL1 CAR-T cell therapy. EASIX/mEASIX/sEASIX scores serve as reliable prognostic indicators for severe CRS/ICANS following CLL1 CAR-T cell therapy. The preinfusion mEASIX scores of CLL1 CAR-T cells can effectively predict treatment response.

In-plane ESPI with unlimited angle of view for multi-object rotation angle determination.

The in-plane electronic speckle pattern interferometry (ESPI), implemented in a Michelson stellar interferometer-like configuration, offers high sensitivity and dynamic measurement. However, its limited angle of view (AOV) remains a major challenge for the rotation angle determination of multiple objects. In this Letter, we analyze the main factors that influence the AOV of the in-plane ESPI and propose an "image transmitting" approach to enlarge the AOV. With the aid of a folded dual-telescope imaging system, we develop an AOV-unlimited interferometer that can determine multi-object rotation angles in real time. The practicability of the interferometer is demonstrated by the application in real-time measuring of the rotation angles of the disks within a 2D granular system.

USP13 interacts with cohesin and regulates its ubiquitination in human cells.

Cohesin is a multiprotein ring complex that regulates 3D genome organization, sister chromatid cohesion, gene expression, and DNA repair. Cohesin is known to be ubiquitinated, although the mechanism, regulation, and effects of cohesin ubiquitination remain poorly defined. We previously used gene editing to introduce a dual epitope tag into the endogenous allele of each of 11 known components of cohesin in human HCT116 cells. Here we report that mass spectrometry analysis of dual-affinity purifications identified the USP13 deubiquitinase as a novel cohesin-interacting protein. Subsequent immunoprecipitation/Western blots confirmed the endogenous interaction in HCT116, 293T, HeLa, and RPE-hTERT cells; demonstrated that the interaction occurs specifically in the soluble nuclear fraction (not in the chromatin); requires the ubiquitin-binding domains (UBA1/2) of USP13; and occurs preferentially during DNA replication. Reciprocal dual-affinity purification of endogenous USP13 followed by mass spectrometry demonstrated that cohesin is its primary interactor in the nucleus. Ectopic expression and CRISPR knockout of USP13 showed that USP13 is paradoxically required for both deubiquitination and ubiquitination of cohesin subunits in human cells. USP13 was dispensable for sister chromatid cohesion in HCT116 and HeLa cells, whereas it was required for the dissociation of cohesin from chromatin as cells transit through mitosis. Together these results identify USP13 as a new cohesin-interacting protein that regulates the ubiquitination of cohesin and its cell cycle regulated interaction with chromatin.

Dual stereo-digital image correlation system for simultaneous measurement of overlapped wings with a polarization RGB camera and fluorescent speckle patterns.

Simultaneous monitoring of overlapped multi-wing structure by stereo-digital image correlation (stereo-DIC) may be used to quantify insect motion and deformation. We propose a dual stereo-DIC system based on multispectral imaging with a polarization RGB camera. Different fluorescent speckle patterns were fabricated on wings, which emit red and blue spectra under ultraviolet light that were imaged and separated using a polarization RGB camera and auxiliary optical splitting components. The resulting dual stereo-DIC system was validated through translation experiments with transparent sheets and reconstructed overlapped insect wings (cicadas). Dynamic measurements of the Ruban artificial flier indicate the efficacy of this approach to determining real insect flight behavior.

Measurement of natural frequencies and mode shapes of transparent insect wings using common-path ESPI.

In this study, a common-path electronic speckle pattern interferometry system which upholds the natural property of transparency of insect's wings has been developed to measure the wings' natural frequencies and mode shapes for the first time. A novel base-exciting method was designed to enable the simultaneous application of sinusoidal and static forces to excite wings and introduce an additional phase. The moiré effect induced by the amplitude modulation was employed to accurately recognize the resonance state. Subsequently, the mode shapes were visualized by phase-shifting and real-time frame subtraction. Eight pairs of forewings from cicadas were investigated. The first three order natural frequencies of the wings are approximately 145 Hz, 272 Hz and 394 Hz, respectively, which are dispersed to prevent modal coupling. The cambered mode shapes exhibit a strongly spanwise-chordwise anisotropy flexural stiffness distribution, generally dominated by bending and twisting deformation. The details of the high-order mode shapes show that the tip exhibits distinct deformation, indicating more flexibility to cope with external impact load, and the nodal lines usually comply with the direction of the wing veins in higher modes, substantiating the fact that the veins play an important role as stiffeners of the membrane. The results are in excellent agreement with the dynamic performance of previous studies, which will potentially affect a broader community of optical measurement specialists and entomologists to enhance our understanding of time-averaged interferograms and insect flights.

Tri-wavelength simultaneous ESPI for 3D micro-deformation field measurement.

Electronic speckle pattern interferometry (ESPI), a well-established technique for micro-deformation measurement, can be used to determine both in-plane and out-of-plane displacement components. Although many works in ESPI have been reported for three-dimensional (3D) displacement measurement, few works have focused on the simultaneous measurement of 3D deformation fields. Here we present an ESPI system that consists of three sub-interferometers for simultaneous measurement of all three displacement components and in-plane strain fields. A 3CCD color camera, a specially designed shifting stage, and three lasers with optimal wavelengths are used in this system. The lasers and 3CCD camera provide independent interferograms with different color signals, while the shifting stage allows the sub-interferometers to achieve simultaneous phase shifting. The results of color separation and experimental measurement demonstrate the utility of the system.

Binocular camera calibration based on timing correction.

Camera calibration is crucial to the application of binocular measurement. However, many of the calibrations are carried out manually, so shaking of the calibration plate cannot be avoided. When the cameras are not synchronized or the exposure time is inconsistent, the image acquisition time of different cameras does not correspond strictly, which will introduce inevitable calibration errors. In this paper, two consecutive frames are collected instead of one frame, and the calibration data are corrected by the image acquisition time value returned by the camera. Experiments show that the proposed method can greatly reduce the re-projection error of calibration, and achieve higher calibration accuracy and less image quantity dependence.

Experimental verification of full-field accuracy in stereo-DIC based on the ESPI method.

This paper proposes a method to merge stereo-digital image correlation (DIC) and electronic speckle pattern interferometry (ESPI) data by camera calibration. The proposed method is employed to verify the accuracy of full-field out-of-plate displacements measured by stereo-DIC in a cantilever beam test. The mean absolute error and the root mean square error (RMSE) of the full-field displacement measured by four-megapixel cameras are 0.849 µm and 1.08 µm at 60 mm field of view, respectively, and the RMSE of the central area is 0.615 µm. The errors are not uniformly distributed because of the imperfect calibration. When the lenses are changed and the field of view reaches 120 mm, the RMSE is 1.48 µm with uniform distribution. These accuracies could be traced back to the laser wavelength to confirm the stereo-DIC data. The proposed method can be used not only to verify the full-field measurement accuracy of DIC but also to determine the rigid-body displacement for ESPI with a high-precision stereo-DIC. Thus, the displacement vector can be obtained. Furthermore, it can unify the coordinate of multiple ESPI systems to achieve a large range of high-precision three-dimensional deformation measurements.

Internal displacement measurements based on color fluorescent speckle pattern by multispectral stereo-DIC and refractive index correction.

Fluorescent digital image correlation (DIC) is becoming popular for measuring 3D profiles and deformations in external surfaces. However, the simultaneous monitoring of interior layers is highly challenging due to the penetrability and refraction of light using monochromatic fluorescence. We propose a color fluorescent speckle pattern (CFSP) method for measuring the internal displacement of transparent objects based on multispectral stereo-DIC and refractive index correction. During sample fabrication, fluorescent speckle patterns exciting different colors are fabricated on both the surface and interior layers of objects. A virtual color stereo-DIC system is utilized to capture the CFSP on the surface and interior layers simultaneously from two different perspectives. Different color channels are practically equivalent to synchronized monochrome vision systems, having separate CFSP in external and internal measurements. In multispectral stereo-DIC calculation, the external surface is initially reconstructed through one channel of the system even if the surface is non-planar. Based on Snell's law and the CFSP method, the internal layer is then reconstructed and corrected by establishing the geometry of the refractive stereo-DIC through another channel. The relative error of the thickness between two planar layers was proved to decrease from 33.4% to 0.7% after refractive index correction. Further experimental results validate the efficacy of this method for correcting the profile of the non-planar arc profile and determining the internal deformations of disc materials.

Semantic speckle: an auto-located speckle pattern for DIC measurement.

Digital image correlation (DIC) has been widely used in both experimental mechanics and engineering fields. The matching algorithm of the DIC method usually requires surfaces containing a random speckle pattern as a deformation information carrier. The speckle pattern plays an irreplaceable role in DIC, which has led to extensive research on it. However, most previous research had always focused on the fabrication and computational performance of the speckle, ignoring the value of intentionally defining the meaning of speckle in design. In this study, we describe a novel, to the best of our knowledge, speckle pattern named semantic speckle. It is a digital speckle composed of several different speckle patterns with similar characteristics. Based on the deep-learning method and matching algorithm, the central location of the semantic part in the overall speckle image can be obtained automatically. Through the intentional definition of the semantic part, it can be possible to calibrate the camera parameters and correct the external parameters of the DIC systems.

Effect of thrombomodulin gene polymorphisms on venous thromboembolism: An analysis of evidence involving 6,629 patients.

BACKGROUD: The association between thrombomodulin gene (THBD) c.1418 C>T polymorphisms and the risk of venous thromboembolism (VTE) is controversial. The purpose of this meta-analysis was to evaluate THBD c.1418 C>T polymorphisms and the risk of VTE. METHODS: Computer searches were performed on the CNKI, Wanfang database, VIP database, PubMed, Embase, Web of Science, and Cochrane Library databases. The retrieval time limit was from the establishment of the database to June 2022. Case-control studies and cohort studies of THBD c.1418 C>T polymorphisms associated with VTE were included. The literature was screened according to inclusion and exclusion criteria, data extraction and literature quality evaluation. Meta-analysis was performed using STATA 14.0 software. RESULTS: A total of 12 literature were included, including 2980 cases in the case group and 3649 cases in the control group. The meta-analysis results showed no significant association of the THBD c.1418 C> T polymorphisms with the occurrence of VTE (T vs C: OR = 1.17, 95%CI = 0.93-1.48; TT vs CT+CC: OR = 1.00, 95%CI = 0.75-1.33; TT+CT vs CC: OR = 1.22, 95%CI = 0.94-1.59). Subgroup analyses revealed an increased risk of VTE in Asian populations due to THBD c.1418 C>T polymorphisms (T vs C: OR = 1.48, 95%CI = 1.06-2.07; TT vs CT+CC: OR = 1.80, 95%CI = 1.13-2.85; TT+CT vs CC: OR = 1.58, 95%CI = 1.07-2.32). THBD c.1418 C>T polymorphisms increased the risk of DVT (T vs C: OR = 1.51, 95%CI = 1.24-1.85; TT vs CT+CC: OR = 1.85, 95%CI = 1.10-3.12; TT+CT vs CC: OR = 1.64, 95%CI = 1.28-2.11). THBD c.1418 C>T polymorphisms reduced the risk of VTE in non-Asian populations (TT vs CT+CC: OR = 0.66, 95%CI = 0.45-0.98). CONCLUSION: THBD c.1418 C>T polymorphisms is associated with VTE in Asian population, which may be a factor in the occurrence of VTE in Asian population. THBD c.1418 C>T polymorphisms increases the risk of DVT. Given the limitations of this meta-analysis, the conclusions require being further supported by large-scale and high-quality studies.

Point-Wise Phase Estimation Method in Fringe Projection Profilometry under Non-Sinusoidal Distortion.

In fringe projection profilometry, high-order harmonics information of distorted fringe will lead to errors in the phase estimation. In order to solve this problem, a point-wise phase estimation method based on a neural network (PWPE-NN) is proposed in this paper. The complex nonlinear mapping relationship between the gray values and the phase under non-sinusoidal distortion is constructed by using the simple neural network model. It establishes a novel implicit expression for phase solution without complicated measurement operations. Compared with the previous method of combining local image information, it can accurately calculate each phase value by point. The comparison results show that the traditional method is with periodic phase errors, while the proposed method can effectively eliminate phase errors caused by non-sinusoidal phase shifting.

Low-dose decitabine plus venetoclax is safe and effective as post-transplant maintenance therapy for high-risk acute myeloid leukemia and myelodysplastic syndrome.

Acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) are usually associated with poor outcomes, especially in high-risk AML/MDS. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative option for patients suffering from high-risk AML/MDS. However, many patients relapse after allo-HSCT. Novel therapy to prevent relapse is urgently needed. Both the BCL-2 inhibitor venetoclax (VEN) and the hypomethylating agent decitabine (DEC) possess significant antitumor activity effects against AML/MDS. Administration of DEC has been shown to ameliorate graft-versus-host disease (GVHD) and boost the graft-versus-leukemia (GVL) effect post-transplantation. We therefore conducted a prospective study (ChiCTR1900025374) to examine the tolerability and efficacy of a maintenance therapy of low-dose decitabine (LDEC) plus VEN to prevent relapse after allo-HSCT for high-risk AML/MDS patients. Twenty patients with high-risk AML (n = 17) or high-risk MDS (n = 3) post-transplantation were recruited. Approximately day 100 post-transplantation, all patients received LDEC (15 mg/m2 for 3 d) followed by VEN (200 mg) on d 1-21. The cycle interval was 2 mo, and there was 10 cycles. The primary end points of this study were rates of overall survival (OS) and event-free survival (EFS). The secondary endpoints included adverse events (AEs), cumulative incidence of relapse (CIR), nonrelapse mortality (NRM), incidences of acute GVHD (aGVHD) and chronic GVHD (cGVHD), and incidences of viral infection after allo-HSCT. Survival outcomes were assessed using Kaplan-Meier analysis. The median follow-up was 598 (149-1072) d. Two patients relapsed, 1 died, and 1 is still alive after the second transplant. The 2-y OS and EFS rates were 85.2% and 84.7%, respectively. The median 2-y EFS time was 525 (149-1072) d, and 17 patients still had EFS and were alive at the time of this writing. The most common AEs were neutropenia, anemia, thrombocytopenia, neutropenic fever, and fatigue. Grade 2 or 3 AEs were observed in 35% (7/20) and 20% (4/20) of the patients, respectively. No grade >3 AEs were observed. aGVHD (any grade) and cGVHD (limited or extensive) occurred in 55% and 20% of patients, respectively. We conclude that LDEC + VEN can be administered safely after allo-HSCT with no evidence of an increased incidence of GVHD, and this combination decreases the relapse rate in high-risk AML/MDS patients. This novel maintenance therapy may be a promising way to prevent relapse in high-risk AML/MDS patients.

CD19 CAR-T cell treatment conferred sustained remission in B-ALL patients with minimal residual disease.

The persistence or recurrence of minimal residual disease (MRD) after chemotherapy predicts relapse of B-cell acute lymphoblastic leukemia (B-ALL). CD19-directed chimeric antigen receptor T (CD19 CAR-T) cells have shown promising responses in B-ALL. However, their role in chemotherapy-refractory MRD-positive B-ALL remains unclear. Here we aimed to assess the effectiveness and safety of CD19 CAR-T cells in MRD-positive B-ALL patients. From January 2018, a total of 14 MRD-positive B-ALL patients received one or more infusions of autogenous CD19 CAR-T cells. Among them, 12 patients achieved MRD-negative remission after one cycle of CAR-T infusion. At a median follow-up time of 647 days (range 172-945 days), the 2-year event-free survival rate in MRD-positive patients was 61.2% ± 14.0% and the 2-year overall survival was 78.6 ± 11.0%, which were significantly higher than patients with active disease (blasts ≥ 5% or with extramedullary disease). Moreover, patients with MRD had a lower grade of cytokine release syndrome (CRS) than patients with active disease. However, the peak expansion of CAR-T cells in MRD positive patients showed no statistical difference compared to patients with active disease. Five patients received two or more CAR-T cell infusions and these patients showed a decreased peak expansion of CAR-T cell in subsequent infusions. In conclusion, pre-emptive CD19 CAR-T cell treatment is an effective and safe approach and may confer sustained remission in B-ALL patients with chemotherapy-refractory MRD. The trials were registered at www.chictr.org.cn as ChiCTR-ONN-16009862 (November 14, 2016) and ChiCTR1800015164 (March 11, 2018).

Multifunctional ultrathin reflective metasurface via polarization-decoupled phase for arbitrary circularly or elliptically polarized waves.

Metasurface offers a promising platform in the design of multifunctional devices owing to its unique ability for EMWs manipulation. However, wave-manipulation capabilities for metasurfaces face challenges in manipulating orthogonal EMWs with arbitrary circularly or elliptically polarized EMWs in the microwave region. Herein, single-layer reflective metasurfaces are proposed for independent manipulation of an arbitrary set of orthogonal circularly or elliptically polarized EMWs via polarization-decoupled phase. Taking advantage of single-layer anisotropic meta-atoms, the proposed metasurface can act as a tandem phase modulator, which introduces polarization-decoupled phase profiles for arbitrary circularly and elliptically polarized EMWs based on the Jones matrix. In this way, the proposed metasurface can distinguish a set of orthogonal EMWs with circular or elliptical polarization states and impose arbitrary phase profiles on them independently and simultaneously. For proof-of-concept, bifunctional metasurfaces operating in the microwave region are presented for independent manipulation of three different sets of orthogonal circularly or elliptically polarized EMWs. They create dual independent channels associated with a pair of orthogonal polarization states, performing functions including polarization beam splitting and orbital angular momentum (OAM) multiplexing. Measured and simulated results show a good agreement, confirming that the proposed single-layer reflective metasurfaces are efficient devices that enable meta-devices to independently control arbitrary circular and elliptical polarized EMWs, achieving arbitrary functionalities.

Refractive three-dimensional reconstruction for underwater stereo digital image correlation.

Measuring the three-dimensional (3D) deformation of submerged objects through different media with the stereo digital image correlation (stereo-DIC) method involves the refractive optical imaging problem where the non-linear transmission of light is induced by a change of medium density. The problem invalidates the underlying single viewpoint assumption of the perspective model in regular stereo-DIC, thereby resulting in erroneous measurements of 3D shape and deformation. In this work, we propose a refractive stereo-DIC method that overcomes the problem by considering light refraction in 3D reconstruction. We formulate a full refractive reconstruction geometry description based on Snell's law of flat refraction and the regular triangulation. This allows the true shape to be effectively reconstructed by tracing and establishing the refracted ray-paths based on the regular 3D reconstruction, without reformulating the camera model and image formation. The refractive stereo-DIC is finally established by integrating the refractive 3D reconstruction into the regular DIC framework for measuring accurate 3D shape and deformation of submerged objects. We experiment the proposed approach with underwater 3D shape and deformation measurements. Both results prove its feasibility and correctness, further heralding our approach as a flexible solution that could readily extend the stereo-DIC to fluid-immersed 3D deformation characterization.

Generalized 2-step phase-shifting algorithm for fringe projection.

Fringe projection profilometry using the phase-shifting technique enables high-precision, high-speed and flexible measurements. Among them, the two-step phase-shifting method has become an important approach to coordinate the accuracy and measurement speed; methods especially based on the amount of phase-shift of π/2, π or 3π/2 can improve time efficiency by reducing steps in unique way. In this paper, a phase iterative technique is proposed and established for two-step phase-shifting with arbitrary phase shift. The general mathematical scheme and parameters linear and nonlinear optimization of the proposed method are described in detail. The simulational and experimental results show that the proposed technique is an effective and precise phase detection method for two-step phase-shifting profilometry.

Efficient ESPI method to identify vibration characteristics of transparent films.

Electronic speckle pattern interferometry (ESPI) has been frequently used to study vibration characteristics of engineering structures. However, efficient ESPI methods for identifying the vibration characteristics of transparent membranes are rarely reported. A convenient approach to determine the resonant frequencies and the vibration modes of transparent films is proposed. A quasi-common-path ESPI (QCP-ESPI) is developed to detect out-of-plane deformation and visualize vibrational modes of a vibrating transparent diaphragm. An amplitude-modulation-based method is proposed for quick and accurate determining resonance of oscillating objects during frequency scanning. Experimental performances demonstrate the feasibility and efficiency of the QCP-ESPI and amplitude-modulation-based methods for determining the resonant frequency and vibration modes of transparent objects.

Optimization of multiscale digital speckle patterns for multiscale deformation measurement using stereo-digital image correlation.

Simultaneous monitoring of multiple fields of view (FOVs) by multiscale stereo-digital image correlation (stereo-DIC) can quantify the deformation of a material when localized phenomena occur within a larger FOV or moving object. In multiscale deformation measurement via stereo-DIC, optimization of the digital speckle patterns (DSPs) is essential to achieve high accuracy and efficiency. This work optimizes and fabricates multispectral DSPs used for multiple scales. First, an optimization of the DSP for two FOVs is achieved using both spatial modulation and specified spectra. A spatially modulated DSP is compared with two spectral DSPs achieved by visible and ultraviolet-excited blue light. Then, a spatially modulated visible DSP fabricated by an ultraviolet printer overlaid with an ultraviolet-excited blue DSP fabricated by a photosensitive seal is designed for multiscale stereo-DIC measurements of three FOVs. Experiments were performed to illustrate the functionality and utility of this multiscale DSP. Such experimental analyses can supply adequate full-field data to validate localized or kinetic mechanical behavior.

Primary role of increasing urea-N concentration in a novel Microcystis densa bloom: Evidence from ten years of field investigations and laboratory experiments.

A novel Microcystis bloom caused by Microcystis densa has occurred in a typical subtropical reservoir every spring and summer since 2012, and it has caused several ecological and economic losses. To determine the environmental factors that influence the growth and physiological characteristics of M. densa, we investigated the variations in physicochemical factors and M. densa cell density from 2007 to 2017. The results showed that the urea-N concentration increased significantly (from 0.02 ± 0.00-0.20 ± 0.01 mg N l-1), whereas other factors did not vary significantly. NO3--N and urea-N concentrations were higher than the NH4+-N concentration during the M. densa bloom. The nitrogen composition changed, and urea-N and NO3--N became a major nitrogen sources in the reservoir. Water temperature and increased urea-N concentrations were the primary factors that influenced variations in M. densa cell density (45.5%, p < 0.05). Laboratory experiments demonstrated that M. densa cultured with urea-N exhibited a higher maximum cell density (9.8 ± 0.5 × 108 cells l-1), more cellular pigments for photosynthesis (chlorophyll a and phycocyanin) and photoprotection (carotenoid), and more proteins than those cultured with NH4+-N and NO3--N. These results suggested that M. densa cultured with urea-N exhibited preferable growth and physiological conditions. Moreover, M. densa exhibited an increased maximum specific uptake rate (0.93 pg N cell-1 h-1) and reduced half-saturation constant (0.03 mg N l-1) for urea-N compared with NH4+-N and NO3--N, suggesting that M. densa preferred urea-N as its major nitrogen source. These results collectively indicated that the increasing urea-N concentration was beneficial for the growth and physiological conditions of M. densa. This study provided ten years of field data and detailed physiological information supporting the critical effect of urea-N on the growth of a novel bloom species M. densa. These findings helped to reveal the mechanism of M. densa bloom formation from the perspective of dissolved organic nitrogen.