Cystathionine γ-lyase contributes to exacerbation of periodontal destruction in experimental periodontitis under hyperglycemia.

BACKGROUND: Diabetes is one of the major inflammatory comorbidities of periodontitis via 2-way interactions. Cystathionine γ-lyase (CTH) is a pivotal endogenous enzyme synthesizing hydrogen sulfide (H2S), and CTH/H2S is crucially implicated in modulating inflammation in various diseases. This study aimed to explore the potential role of CTH in experimental periodontitis under a hyperglycemic condition. METHODS: CTH-silenced and normal human periodontal ligament cells (hPDLCs) were cultured in a high glucose and Porphyromonas gingivalis lipopolysaccharide (P.g-LPS) condition. The effects of CTH on hPDLCs were assessed by Cell Counting Kit 8 (CCK8), real-time quantitative polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA). The model of experimental periodontitis under hyperglycemia was established on both Cth-/- and wild-type (WT) mice, and the extent of periodontal destruction was assessed by micro-CT, histology, RNA-Seq, Western blot, tartrate-resistant acid phosphatase (TRAP) staining and immunostaining. RESULTS: CTH mRNA expression increased in hPDLCs in response to increasing concentration of P.g-LPS stimulation in a high glucose medium. With reference to WT mice, Cth-/- mice with experimental periodontitis under hyperglycemia exhibited reduced bone loss, decreased leukocyte infiltration and hindered osteoclast formation, along with reduced expression of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in periodontal tissue. RNA-seq-enriched altered NF-κB pathway signaling in healthy murine gingiva with experimental periodontitis mice under hyperglycemia. Accordingly, phosphorylation of p65 (P-p65) was alleviated in CTH-silenced hPDLCs, leading to decreased expression of IL6 and TNF. CTH knockdown inhibited activation of nuclear factor kappa-B (NF-κB) pathway and decreased production of proinflammatory cytokines under high glucose and P.g-LPS treatment. CONCLUSION: The present findings suggest the potential of CTH as a therapeutic target for tackling periodontitis in diabetic patients.

Effect of Steam Pressure Toasting Duration on Snowbird Faba Bean Seeds and the Impact on the Intestinal and Metabolic Characteristics in Dairy Cows.

The response of feedstuffs to thermal processing depends on the type of feed and the thermal processing methods being applied. Steam pressure toasting (SPT) has been used to modify the nutrient degradability and enhance the nutritional quality of pulses, including faba bean seeds (FBS). Strategic feeding approaches are essential for balancing diets and maintaining adequate nutrition, especially in high-performing ruminants. This research aimed to determine the effects of SPT duration in FBS on the intestinal and metabolic characteristics of dairy cows. Faba Bean seeds (three harvesting years) were processed at 121 °C for 0, 30, 60, 90, and 120 min. Rumen degradation and intestinal digestion were determined using the in situ and modified in vitro three-step techniques. The true protein supplied to the small intestine was also determined using the NRC and DVE systems. Our results showed a reduced total digested DM (TDDM) with longer SPT duration (quadratic, p = 0.02). The intestinally digested crude protein (IADP) increased from 62 to 220 g/kg DM with 0 to 120 min of SPT, respectively (p < 0.01), whereas the total tract digestible starch (TDSt) gradually decreased from 321 to 182 g/kg DM based on SPT time (p < 0.01). On the other hand, the truly digested protein in the small intestine (DVE) and the total metabolizable protein (MP) increased from 138 to 282 g/kg DM and 129 to 282 g/kg DM, respectively, with 0 to 120 min of SPT (quadratic, p < 0.01). The Feed Milk Value (FMV), based on both the DVE/OEB and NRC dairy nutrition systems, also increased with SPT (Quadratic, p < 0.01). The processing of FBS with SPT at 121 °C effectively reduced the highly degradable protein fraction in the rumen, shifting to a higher rumen undegraded protein (RUP) which was able to reach the small intestine. In the current study, the total MP, DVE, and FMV in dairy cows showed an overall increase with SPT in FBS.

Hetero-Solvation-Diluted Strongly-Coordinated Zn2+ -Cosolvent Pairs Downshifting Zn Electrode Potential for High-Voltage Hybrid Batteries.

Mild aqueous Zn batteries (AZBs) generally suffer a low-voltage/energy dilemma, which compromises their competitiveness for large-scale energy storage. Pushing Zn anode potential downshift is an admissible yet underappreciated approach for high-voltage/energy AZBs. Herein, with a mild hybrid electrolyte containing in situ-derived diluted strongly-coordinated Zn2+ -cosolvent pairs, a considerable Zn anode potential downshift is initially achieved for high-voltage Zn-based hybrid batteries. The chosen butylpyridine cosolvent not only strongly coordinates Zn2+ ions but also acts as a hydrogen-bond end-capping agent to inhibit hydrogen evolution reaction (HER). The electrolyte environment with hetero-solvation-diluted strongly-coordinated Zn2+ -cosolvent pairs remarkably lowers Zn2+ activity, responsible for the Zn electrode potential downshift (-0.330 V vs Zn), confirming to modified Nernst law (ΔE = R T n F $\frac{{RT}}{{nF}}$ ln[a(Zn2 + )/a(coordinated solvent)]). With the diluted Zn2+ -containing hybrid electrolyte, the Zn//Zn symmetric cell in the hybrid electrolyte shows a long lifespan over 1270 h at a stripping/plating capacity of 0.4 mA h cm-2 . Compared with in common hybrid electrolytes, the as-assembled Zn-MnO2 hybrid battery delivers a ca. 0.278 V enhanced voltage plateau (1.57 V) and a long-term cyclability of over 736 cycles. This work opens a new avenue toward Zn anode potential downshift for high-voltage AZBs, which can extend to other mild metal batteries.

Research updates and progress on nutritional significance of the amides I and II, alpha-helix and beta-sheet ratios, microbial protein synthesis, and steam pressure toasting condition with globar and synchrotron molecular microspectroscopic techniques with chemometrics.

This article aims to review research updates and progress on the nutritional significance of the amides I and II, the alpha-helix and beta-sheet ratios, the microbial protein synthesis, and the steam pressure toasting condition in food and feed with globar and synchrotron molecular microspectroscopic techniques plus chemometrics (both univariate and multivariate techniques). The review focused on (I) impact of the amides I and II, and the alpha-helix and beta-sheet-structure ratios in food and feeds; (II) Current research progress and update in synchrotron technique and application in feed and food molecular structure studies that are associated with nutrition delivery; (III) Impact of thermal processing- steam pressure toasting condition on feed and food; (IV). Impact of the microbial protein synthesis and methodology on feed and food; and (V). Impact on performance and production of ruminants with Faba beans.

Identification and assessment of differentially expressed necroptosis long non-coding RNAs associated with periodontitis in human.

BACKGROUND: Periodontitis is the most common oral disease and is closely related to immune infiltration in the periodontal microenvironment and its poor prognosis is related to the complex immune response. The progression of periodontitis is closely related to necroptosis, but there is still no systematic study of long non-coding RNA (lncRNA) associated with necroptosis for diagnosis and treatment of periodontitis. MATERIAL AND METHODS: Transcriptome data and clinical data of periodontitis and healthy populations were obtained from the Gene Expression Omnibus (GEO) database, and necroptosis-related genes were obtained from previously published literature. FactoMineR package in R was used to perform principal component analysis (PCA) for obtaining the necroptosis-related lncRNAs. The core necroptosis-related lncRNAs were screened by the Linear Models for Microarray Data (limma) package in R, PCA principal component analysis and lasso algorithm. These lncRNAs were then used to construct a classifier for periodontitis with logistic regression. The receiver operating characteristic (ROC) curve was used to evaluate the sensitivity and specificity of the model. The CIBERSORT method and ssGSEA algorithm were used to estimate the immune infiltration and immune pathway activation of periodontitis. Spearman's correlation analysis was used to further verify the correlation between core genes and periodontitis immune microenvironment. The expression level of core genes in human periodontal ligament cells (hPDLCs) was detected by RT-qPCR. RESULTS: A total of 10 core necroptosis-related lncRNAs (10-lncRNAs) were identified, including EPB41L4A-AS1, FAM30A, LINC01004, MALAT1, MIAT, OSER1-DT, PCOLCE-AS1, RNF144A-AS1, CARMN, and LINC00582. The classifier for periodontitis was successfully constructed. The Area Under the Curve (AUC) was 0.952, which suggested that the model had good predictive performance. The correlation analysis of 10-lncRNAs and periodontitis immune microenvironment showed that 10-lncRNAs had an impact on the immune infiltration of periodontitis. Notably, the RT-qPCR results showed that the expression level of the 10-lncRNAs obtained was consistent with the chip analysis results. CONCLUSIONS: The 10-lncRNAs identified from the GEO dataset had a significant impact on the immune infiltration of periodontitis and the classifier based on 10-lncRNAs had good detection efficiency for periodontitis, which provided a new target for diagnosis and treatment of periodontitis.

The abscopal effect of anti-CD95 and radiotherapy in melanoma.

BACKGROUND: Radiotherapy (RT) is frequently adopted to control cancer cell proliferation, which is achieved by altering the tumor microenvironment (TME) and immunogenicity. Apoptosis of cancer cells is the major effect of radiation on tumor tissues. Fas/APO-1(CD95) receptors on the cell membrane are death receptors that can be activated by diverse factors, including radiation and integration with CD95L on CD8+ T cells. The abscopal effect is defined as tumor regression out of the local RT field, and it is produced through anti-tumor immunity. The immune response against the radiated tumor is characterized by the cross-presentation between antigen-presenting cells (APCs), which includes cytotoxic T cells (CTLs) and dendritic cells (DCs). METHODS: The effect of activation and radiation of CD95 receptors on melanoma cell lines was examined in vivo and in vitro. In vivo, bilateral lower limbs were given a subcutaneous injection of a dual-tumor. Tumors in the right limb were radiated with a single dose of 10 Gy (primary tumor), while tumors in the left limb (secondary tumor) were spared. RESULTS: The anti-CD95 treatment plus radiation (combination treatment) reduced growth rates of both primary and secondary tumors relative to the control or radiation groups. In addition, higher degrees of infiltrating CTLs and DCs were detected in the combination treatment compared to the other groups, but the immune response responsible for secondary tumor rejection was not proven to be tumor specific. In vitro, combination treatment combined with radiation resulted in further apoptosis of melanoma cells relative to controls or cells treated with radiation. CONCLUSIONS: Targeting CD95 on cancer cells will induce tumor control and the abscopal effect.

Hydrated Eutectic Electrolytes Stabilizing Quasi-Underpotential Mg Plating/Stripping for High-Voltage Mg Batteries.

Aqueous rechargeable Mg batteries (ARMBs) usually fail from severe anode passivation, alternatively, executing quasi-underpotential Mg plating/stripping chemistry (UPMC) on a proper heterogeneous metal substrate is a crucial remedy. Herein, a stable UPMC on Zn substrate is initially achieved in new hydrated eutectic electrolytes (HEEs), delivering an ultralow UPMC overpotential and high energy/voltage plateau of ARMBs. The unique eutectic property remarkably expands the lower limit of electrochemical stability window (ESW) of HEEs and undermines the competition between hydrogen evolution/corrosion reactions and UPMC, enabling a reversible UPMC. The UPMC is carefully revealed by multiple characterizations, which shows a low overpotential of 50 mV at 0.1 mA cm-2 over 550 h. With sulfonic acid-doped polyaniline (SPANI) cathodes, UPMC-based full cells show high energy/power densities of 168.6 Wh kg-1 /2.1 kWh kg-1 and voltage plateau of 1.3 V, far overwhelming conventional aqueous systems.

Effects of dietary oat supplementation on carcass traits, muscle metabolites, amino acid profiles, and its association with meat quality of Small-tail Han sheep.

Oat supplementation of the ruminant diet can improve growth performance and meat quality traits, but the role of muscle metabolites has not been evaluated. This study aimed to establish whether oat grass supplementation (OS) of Small-tail Han sheep improved growth performance and muscle tissue metabolites that are associated with better meat quality and flavor. After 90-day, OS fed sheep had higher live-weight and carcass-weight, and lower carcass fat. Muscle metabolomics analysis showed that OS fed sheep had higher levels of taurine, l-carnitine, inosine-5'-monophospgate, cholic acid, and taurocholic acid, which are primarily involved in taurine and hypotaurine metabolism, purine metabolism, and bile acid biosynthesis and secretion, decreased fat accumulation and they promote functional or flavor metabolites. OS also increased muscle levels of amino acids that are attributed to better quality and flavorsome mutton. These findings provided further evidence for supplementing sheep with oat grass to improve growth performance and meat quality.

Manipulating OH- -Mediated Anode-Cathode Cross-Communication Toward Long-Life Aqueous Zinc-Vanadium Batteries.

The anode-cathode interplay is an important but rarely considered factor that initiates the degradation of aqueous zinc ion batteries (AZIBs). Herein, to address the limited cyclability issue of V-based AZIBs, Al2 (SO4 )3 is proposed as decent electrolyte additive to manipulate OH- -mediated cross-communication between Zn anode and NaV3 O8 ⋅ 1.5H2 O (NVO) cathode. The hydrolysis of Al3+ creates a pH≈0.9 strong acidic environment, which unexpectedly prolongs the anode lifespan from 200 to 1000 h. Such impressive improvement is assigned to the alleviation of interfacial OH- accumulation by Al3+ adsorption and solid electrolyte interphase formation. Accordingly, the strongly acidified electrolyte, associated with the sedated crossover of anodic OH- toward NVO, remarkably mitigate its undesired dissolution and phase transition. The interrupted OH- -mediated communication between the two electrodes endows Zn||NVO batteries with superb cycling stability, at both low and high scan rates.

In Situ Polymerization of Ionic Liquid with Tunable Phase Separation for Highly Reversible and Ultralong Cycle Life Zn-Ion Battery.

Severe Zn dendrite growth and side reactions greatly limit the application of aqueous zinc-ion batteries. Herein, we design a layer of polyionic liquid (PCAVImBr) film with a tunable pore size and charge density on the Zn anode to endow homogenized distribution of an electronic field, acerated Zn2+ permeation, and inhabitation of water entry. Such an optimal combination is achieved via a polymerization induced phase separation strategy, where the enhanced cross-linking density arrests the phase separation in a shallow depth and vice versa. Furthermore, the Zn@PCAVImBr electrode has good plating/stripping reversibility, which retains a 99.6% CE efficiency after 3000 cycles. The symmetric cells can achieve a cycle life of more than 2400 h at different current densities. It is worth mentioning that the NVO//Zn@PCAVImBr full cell can still reach a 91.2% capacity retention after nearly 4000 cycles at a high current of 10 A g-1, and provides new insights for the future research of zinc-ion battery anodes.

Effects and mechanisms of 6-hydroxykaempferol 3,6-di-O-glucoside-7-O-glucuronide from Safflower on endothelial injury in vitro and on thrombosis in vivo.

Background: The florets of Carthamus tinctorius L. (Safflower) is an important traditional medicine for promoting blood circulation and removing blood stasis. However, its bioactive compounds and mechanism of action need further clarification. Objective: This study aims to investigate the effect and possible mechanism of 6-hydroxykaempferol 3,6-di-O-glucoside-7-O-glucuronide (HGG) from Safflower on endothelial injury in vitro, and to verify its anti-thrombotic activity in vivo. Methods: The endothelial injury on human umbilical vein endothelial cells (HUVECs) was induced by oxygen-glucose deprivation followed by reoxygenation (OGD/R). The effect of HGG on the proliferation of HUVECs under OGD/R was evaluated by MTT, LDH release, Hoechst-33342 staining, and Annexin V-FITC apoptosis assay. RNA-seq, RT-qPCR, Enzyme-linked immunosorbent assay and Western blot experiments were performed to uncover the molecular mechanism. The anti-thrombotic effect of HGG in vivo was evaluated using phenylhydrazine (PHZ)-induced zebrafish thrombosis model. Results: HGG significantly protected OGD/R induced endothelial injury, and decreased HUVECs apoptosis by regulating expressions of hypoxia inducible factor-1 alpha (HIF-1α) and nuclear factor kappa B (NF-κB) at both transcriptome and protein levels. Moreover, HGG reversed the mRNA expression of pro-inflammatory cytokines including IL-1ß, IL-6, and TNF-α, and reduced the release of IL-6 after OGD/R. In addition, HGG exhibited protective effects against PHZ-induced zebrafish thrombosis and improved blood circulation. Conclusion: HGG regulates the expression of HIF-1α and NF-κB, protects OGD/R induced endothelial dysfunction in vitro and has anti-thrombotic activity in PHZ-induced thrombosis in vivo.

Genomic and transcriptomic-based analysis of agronomic traits in sugar beet (Beta vulgaris L.) pure line IMA1.

Sugar beet (Beta vulgaris L.) is an important sugar-producing and energy crop worldwide. The sugar beet pure line IMA1 independently bred by Chinese scientists is a standard diploid parent material that is widely used in hybrid-breeding programs. In this study, a high-quality, chromosome-level genome assembly for IMA1was conducted, and 99.1% of genome sequences were assigned to nine chromosomes. A total of 35,003 protein-coding genes were annotated, with 91.56% functionally annotated by public databases. Compared with previously released sugar beet assemblies, the new genome was larger with at least 1.6 times larger N50 size, thereby substantially improving the completeness and continuity of the sugar beet genome. A Genome-Wide Association Studies analysis identified 10 disease-resistance genes associated with three important beet diseases and five genes associated with sugar yield per hectare, which could be key targets to improve sugar productivity. Nine highly expressed genes associated with pollen fertility of sugar beet were also identified. The results of this study provide valuable information to identify and dissect functional genes affecting sugar beet agronomic traits, which can increase sugar beet production and help screen for excellent sugar beet breeding materials. In addition, information is provided that can precisely incorporate biotechnology tools into breeding efforts.

Effects of oat (Avena sativa L.) hay diet supplementation on the intestinal microbiome and metabolome of Small-tail Han sheep.

Supplementation of the sheep diet with oats (Avena sativa L.) improves animal growth and meat quality, however effects on intestinal microbes and their metabolites was not clear. This study aimed to establish the effect of dietary oat supplementation on rumen and colonic microbial abundance and explore the relationship with subsequent changes in digesta metabolites. Twenty Small-tail Han sheep were randomly assigned to a diet containing 30 g/100 g of maize straw (Control) or oat hay (Oat). After 90-days on experimental diets, rumen and colon digesta were collected and microbial diversity was determined by 16S rRNA gene Illumina NovaSeq sequencing and metabolomics was conducted using Ultra-high performance liquid chromatography Q-Exactive mass spectrometry (UHPLC-QE-MS). Compared to Control group, oat hay increased the abundance of Bacteroidetes and Fibrobacteres as well as known short-chain fatty acid (SCFA) producers Prevotellaceae, Ruminococcaceae and Fibrobacteraceae in rumen (p < 0.05). In rumen digesta, the Oat group showed had higher levels of (3Z,6Z)-3,6-nonadienal, Limonene-1,2-epoxide, P-tolualdehyde, and Salicylaldehyde compared to Control (p < 0.05) and these metabolites were positively correlated with the abundance of cecal Prevotellaceae NK3B31. In conclusion, supplementation of the sheep diet with oat hay improved desirable microbes and metabolites in the rumen, providing insight into mechanisms whereby meat quality can be improved by oat hay supplementation.

Hydroxysafflor yellows alleviate thrombosis and acetaminophen-induced toxicity in vivo by enhancing blood circulation and poison excretion.

BACKGROUND: Hydroxysafflor yellow A (HSYA) from the flower of Carthamus tinctorius (Safflower) has been reported to have various pharmacological effects. However, little is known about the bioactivities of other chemical constituents in Safflower and the relationship between enhancement of blood circulation and hepatoprotection by HSYA. PURPOSE: The present research was to evaluate the antithrombotic and hepatoprotective activities of HSYA and C, examine their mechanisms of actions, including influence on the excretion velocity of acetaminophen, and the relationship between the antithrombotic, hepatoprotective, and other bioactivities. METHODS: The hepatoprotective activities were examined by acetaminophen (APAP)-induced zebrafish toxicity and carbon tetrachloride (CCl4)-induced mouse liver injury. The concentrations of APAP in zebrafish and APAP that was excreted to the culture media were quantified by UHPLC-MS. The anti-thrombosis effect of HSYA and C were examined by the phenylhydrazine (PHZ)-induced zebrafish thrombosis. RESULTS: HSYA and HSYC showed robust protection on APAP-induced toxicity and PHZ-induced thrombosis. The hepatoprotective effects of HSYA and C were more potent than that of the positive control, acetylcysteine (61.7% and 58.0%, respectively, vs. 56.9% at 100 µM) and their antithrombosis effects were more robust than aspirin (95.1% and 86.2% vs. 52.7% at 100 µM). HSYA and C enhanced blood circulation, rescued APAP-treated zebrafish from morphological abnormalities, and mitigated APAP-induced toxicity in liver development in liver-specific RFP-expressing transgenic zebrafish. HSYC attenuated CCl4-induced mouse liver injury and regulated the levels of HIF-1α, iNOS, TNF-α, α-SMA, and NFκB in liver tissues. HSYA was also protective in a dual thrombotic and liver toxicity zebrafish model. By UHPLC-MS, HSYA accelerated the excretion of APAP. CONCLUSION: HSYA and C are the bioactive constituents of Safflower that are responsible for the herbal drug's traditional use in promoting blood circulation to remove blood stasis. Safflower and its chalcone constituents may protect from damage due to exogenous or disease-induced endogenous toxins by enhancing the excretion velocity of toxins.

Preparation and Photocatalytic Performance for Degradation of Rhodamine B of AgPt/Bi4Ti3O12 Composites.

Loading a noble metal on Bi4Ti3O12 could enable the formation of the Schottky barrier at the interface between the former and the latter, which causes electrons to be trapped and inhibits the recombination of photoelectrons and photoholes. In this paper, AgPt/Bi4Ti3O12 composite photocatalysts were prepared using the photoreduction method, and the effects of the type and content of noble metal on the photocatalytic performance of the catalysts were investigated. The photocatalytic degradation of rhodamine B (RhB) showed that the loading of AgPt bimetallic nanoparticles significantly improved the catalytic performance of Bi4Ti3O12. When 0.10 wt% noble metal was loaded, the degradation rate for RhB of Ag0.7Pt0.3/Bi4Ti3O12 was 0.027 min-1, which was respectively about 2, 1.7 and 3.7 times as that of Ag/Bi4Ti3O12, Pt/Bi3Ti4O12 and Bi4Ti3O12. The reasons may be attributed as follows: (i) the utilization of visible light was enhanced due to the surface plasmon resonance effect of Ag and Pt in the visible region; (ii) Ag nanoparticles mainly acted as electron acceptors to restrain the recombination of photogenerated electron-hole pairs under visible light irradiation; and (iii) Pt nanoparticles acted as electron cocatalysts to further suppress the recombination of photogenerated electron-hole pairs. The photocatalytic performance of Ag0.7Pt0.3/Bi4Ti3O12 was superior to that of Ag/Bi4Ti3O12 and Pt/Bi3Ti4O12 owing to the synergistic effect between Ag and Pt nanoparticles.

Genotyping-by-sequencing (GBS), an ultimate marker-assisted selection (MAS) tool to accelerate plant breeding.

Marker-assisted selection (MAS) refers to the use of molecular markers to assist phenotypic selections in crop improvement. Several types of molecular markers, such as single nucleotide polymorphism (SNP), have been identified and effectively used in plant breeding. The application of next-generation sequencing (NGS) technologies has led to remarkable advances in whole genome sequencing, which provides ultra-throughput sequences to revolutionize plant genotyping and breeding. To further broaden NGS usages to large crop genomes such as maize and wheat, genotyping-by-sequencing (GBS) has been developed and applied in sequencing multiplexed samples that combine molecular marker discovery and genotyping. GBS is a novel application of NGS protocols for discovering and genotyping SNPs in crop genomes and populations. The GBS approach includes the digestion of genomic DNA with restriction enzymes followed by the ligation of barcode adapter, PCR amplification and sequencing of the amplified DNA pool on a single lane of flow cells. Bioinformatic pipelines are needed to analyze and interpret GBS datasets. As an ultimate MAS tool and a cost-effective technique, GBS has been successfully used in implementing genome-wide association study (GWAS), genomic diversity study, genetic linkage analysis, molecular marker discovery and genomic selection under a large scale of plant breeding programs.

Assessing phytoplankton using a two-rank database based on excitation-emission fluorescence spectra.

The feasibility of using a two-rank database of reference spectra based on in vivo fluorescence excitation-emission matrix (EEMs) spectra to assess dominant groups of phytoplankton was explored. Twenty-six species belonging to 20 genera of seven divisions were studied. First, fluorescent characteristics of these EEMs were extracted using Daubechies-7 wavelet analysis. Second, the optimal characteristic spectra of scale vectors (SOCS) and time-series vectors (TOCS) were selected; phytoplankton of different genera were classified using Fisher linear discriminant analysis. Third, SOCS and TOCS reference spectra databases were obtained by hierarchical cluster analysis. Using non-negative least squares as the method to assess the phytoplankton, a two-rank reference spectra database was established according to their respective ability to identify the 2818 single-species samples. Using this fluorimetric technique, the correct identification rates (CIRs) for single-species samples were 88.8-100% at the genus level and 98.8-100% at the division level. Dominant species in the 465 laboratory mixtures had corresponding CIRs of 85.6% and 96.1%. Moreover, 15 of the 19 species used as dominants were correctly identified at the genus level. In 27 natural seawater samples, Prorocentrum donghaiense, Thalassiosira nordenskioldi, and Chaetoceros socialis (bloom-forming species with a density of about 10(7) cell L(-1)), and Alexandrium sp. (dominant species with abundance of about 10(6) cell L(-1)) were qualitatively identified at the genus level; other dominant species, with densities of 10(5) to 10(6) cell L(-1), were identified at the division level. The quantitative identification was relatively poor in the natural water samples, and several potential resolutions, including trying both new measuring methods and calculating methods, for future study are given.