Photosynthetic System Based on a Polyoxometalate-Based Dehydrated Metal-Organic Framework for Nitrogen Fixation.

In nature, biological nitrogen fixation is accomplished through the π-back-bonding mechanism of nitrogenase, which poses significant challenges for mimic artificial systems, thanks to the activation barrier associated with the N≡N bond. Consequently, this motivates us to develop efficient and reusable photocatalysts for artificial nitrogen fixation under mild conditions. We employ a charge-assisted self-assembly process toward encapsulating one polyoxometalate (POM) within a dehydrated Zr-based metal-organic framework (d-UiO-66) exhibiting nitrogen photofixation activities, thereby constructing an enzyme-mimicking photocatalyst. The dehydration of d-UiO-66 is favorable for facilitating nitrogen chemisorption and activation via the unpaired d-orbital electron at the [Zr6O6] cluster. The incorporation of POM guests enhanced the charge separation in the composites, thereby facilitating the transfer of photoexcited electrons into the π* antibonding orbital of chemisorbed N2 for efficient nitrogen fixation. Simultaneously, the catalytic efficiency of SiW9Fe3@d-UiO-66 is enhanced by 9.0 times compared to that of d-UiO-66. Moreover, SiW9Fe3@d-UiO-66 exhibits an apparent quantum efficiency (AQE) of 0.254% at 550 nm. The tactics of "working-in-tandem" achieved by POMs and d-UiO-66 are extremely vital for enhancing artificial ammonia synthesis. This study presents a paradigm for the development of an efficient artificial catalyst for nitrogen photofixation, aiming to mimic the process of biological nitrogen fixation.

Marine algae-derived characterized bioactive compounds as therapy for cancer: A review on their classification, mechanism of action, and future perspectives.

In 2022, there were around 20 million new cases and over 9.7 million cancer-related deaths worldwide. An increasing number of metabolites with anticancer activity in algae had been isolated and identified, which were promising candidates for cancer therapy. Red algae are well-known for the production of brominated metabolites, including terpenoids and phenols, which have the capacity to induce cell toxicity. Some non-toxic biological macromolecules, including polysaccharides, are distinct secondary metabolites found in many algae, particularly green algae. They possess anticancer activities by inhibiting tumor angiogenesis, stimulating the immune response, and inducing apoptosis. However, the structure-activity relationship between these components and antitumor activity, as well as certain taxa within the algae, remains relatively unstudied. This work is based on the reports published from 2003 to 2024 in PubMed and ISI Web of Science databases. A comprehensive review of the characterized algal anticancer active compounds, together with their structure and mechanism of action was performed. Also, their structure-activity relationship was preliminarily summarized to better assess their potential properties as a natural, safe bioactive product to be used as an alternative for the treatment of cancers, leading to new opportunities for drug discovery.

SLC38A6 expression in macrophages exacerbates pulmonary inflammation.

Pulmonary inflammation involves complex changes of the immune cells, in which macrophages play important roles and their function might be influenced by metabolism. Slc38a6 acts as a carrier of nutrient for macrophages (Mφ) to exert the function. In this study, pneumonia patient blood was found up-regulated SLC38A6 expression, which correlated with monocytes number and white blood cell number. The similar result was also shown in LPS induced sepsis mice. To reveal the key role of Slc38a6, we used systemic and conditional knock-out mice. Either systemic or LyzCRE specific knock-out could alleviate the severity of sepsis mice, reduce the proinflammatory cytokine TNF-α and IL-1ß expression in serum and decrease the monocytes number in bronchial alveolar lavage and peritoneal lavage via flow cytometry. In order to reveal the signal of up-regulated Slc38a6, the Tlr4 signal inhibitor TAK242 and TLR4 knock-out mice were used. By blocking Tlr4 signal in macrophages via TAK242, the expression of Slc38a6 was down-regulated synchronously, and the same results were also found in Tlr4 knock-out macrophages. However, in the overexpressed Slc38a6 macrophages, blocking Tlr4 signal via TAK242, 20% of the mRNA expression of IL-1ß still could be expressed, indicating that up-regulated Slc38a6 participates in IL-1ß expression process. Collectively, it is the first time showed that an amino acid transporter SLC38A6 up-regulated in monocytes/macrophages promotes activation in pulmonary inflammation. SLC38A6 might be a promising target molecule for pulmonary inflammation treatment.

4'-(8-(4-Methylimidazole)-octyloxy)-arctigenin: The first inhibitor of fish rhabdovirus glycoprotein.

Spring viraemia of carp virus (SVCV), a highly pathogenic rhabdovirus, could cause spring viraemia of carp (SVC) with up to 90% lethality. Like other rhabdoviruses, the entry of SVCV into susceptible cells was mediated by a single envelope glycoprotein G. Specific inhibitors targeting the glycoprotein were the most effective means to alleviate the epidemic. The programs including SWISS-MODEL, I-TASSER, Phyre2 and AlphaFold2 were used to build a three-dimensional structural model of glycoprotein. The structural comparison between SVCV-G and homology protein VSV-G revealed that the SVCV glycoprotein ectodomain (residues 19 to 466) folded into four distinct domains. Based on the potential small molecule binding sites on glycoprotein surfaces, virtual screening of the anti-SVCV drug libraries was performed using Autodock software and 4'-(8-(4-Methylimidazole)-octyloxy)-arctigenin (MOA) with a high binding affinity was identified. The solubility enhancer tags including trigger factor and maltose binding protein were fused with the ectodomain of glycoprotein, and the target protein with a purity of about 90% was successfully obtained. The interaction confirmation tests revealed that the fluorescence intensity of a characteristic peak induced by the endogenous chromophores in glycoprotein was decreased with the addition of MOA, indicating changes in the microenvironment of glycoprotein. Moreover, the interaction could cause a slight conformational change in glycoprotein, as shown by the content of ß-turn, ß-folding, and random coil of protein all increased with the decrease of α-helix content after the addition of MOA compound. These results demonstrated that MOA could act as a novel drug against fish rhabdovirus via direct targeting of glycoprotein.

Photochemical Ammonia Synthesis over Reduced Polyoxovanadate-Intercalated Defective ZnAl Layered Double Hydroxide Nanosheets.

The exploration of efficient and stable N2 fixation photocatalysts featuring a broad absorption spectrum and N2 fixation active sites has become specifically conspicuous. Herein, a series of reduced polyoxovanadates (POVs) were intercalated into copper-induced ZnAl layered double hydroxide (0.5%-ZnAl LDH) nanosheets with oxygen vacancies via an anion exchange strategy toward green ammonia production. The intervalence charge transfer arising from mixed-valence POV materials is responsible for its light-harvesting behavior, and the LDHs lay the foundation for the chemical adsorption and activation process of nitrogen molecules; both contributions facilitate the nitrogen photofixation performance of such composite materials. As predicted, the catalytic efficiency of V34/0.5%-ZnAl is 7.0 times higher than 0.5%-ZnAl LDH. Therefore, such an all-inorganic system exhibits an apparent quantum efficiency of 0.3137% at 500 nm. The strategy of "working in tandem" established by POV-based light-absorber species and oxygen vacancies as the sites for N2 activation is extremely vital for enhanced ammonia formation. This work opens up a versatile insight for the rational design of an efficient photo-driven nitrogen-reduction composite catalyst toward sustainable ammonia production compared to the industrial Haber-Bosch process.

The Contribution of the Internet to Promoting Mental Health for Older Adults: Cross-Sectional Survey in China.

BACKGROUND: Health is an important topic for everyone and essential to high-quality economic and social development. Recently, some researchers have suggested that older adults' internet use may have a health effect. OBJECTIVE: This study specifically aims to clarify the relationship between internet use and the mental health of older adults, for which other surveys present contradictory results. METHODS: Data were obtained from the China Longitudinal Aging Social Survey conducted in 2018. A total of 6648 participants were included. Mental health was assessed by the 12-item Center for Epidemiological Studies Depression Scale. Ordinary least squares regression was adopted to explore the relationship between internet use (independent variable) and the mental health of older adults. Robustness analysis, sensitivity analysis, and heterogeneity analysis were conducted in detail to verify the empirical result. A mediating effect analysis was further conducted to discover the effect mechanism between the dependent and independent variables. RESULTS: It was found that internet use and smartphone use can significantly improve the mental health of older adults (ordinary least squares, ß=.075; P<.001). After endogenous and robustness tests were conducted, the aforementioned conclusion remained robust. In particular, participation in voluntary activities played a mediating role in the relationship between internet use and the mental health of older adults. In addition, younger subjective age enhanced the positive effect of internet use on the mental health of older adults. CONCLUSIONS: Internet users showed higher levels of mental health among Chinese older adults. To improve the mental health of older adults, the government should not only cultivate the ability to use the internet but also encourage greater participation in voluntary activities among older adults.

The contribution of audiobook use on the mental health of older adults: the mediating effects of social adaptation.

Objectives: This study aims to examine the association between audiobook use and the mental health of older adults.Methods: Data were from the 2018 China Longitudinal Aging Social Survey(CLASS 2018). The study utilized multiple linear regression to examine the association between audiobook use and the mental health of older adults. Robustness and heterogeneity analyses were conducted to validate the findings. Mediation analysis was employed to assess the mediating role of social adaptation in the relationship between audiobook use and mental health.Results: The study revealed a significant positive association between audiobook use and the mental health of older adults. Further mediation analysis indicated that social adaptation played a mediating role in this relationship.Conclusion: These findings underscore the potential of audiobooks as a valuable tool for promoting the mental health of older individuals. The research emphasizes the significance of integrating audiobook interventions into strategies aimed at enhancing the mental health of the older adults.

Self-Assembly of Polyoxometalate-Based Sub-1†nm Polyhedral Building Blocks into Rhombic Dodecahedral Superstructures.

Self-assembly of subnanometer (sub-1 nm) scale polyhedral building blocks can yield some superstructures with novel and interesting morphology as well as potential functionalities. However, achieving the self-assembly of sub-1 nm polyhedral building blocks is still a great challenge. Herein, through encapsulating the titanium-substituted polyoxometalate (POM, K7 PTi2 W10 O40 ) with tetrabutylammonium cations (TBA+ ), we first synthesized a sub-1 nm rhombic dodecahedral building block by further tailoring the spatial distribution of TBA+ on the POM. Molecular dynamics (MD) simulations demonstrated the eight TBA+ cations interacted with the POM cluster and formed the sub-1 nm rhombic dodecahedron. As a result of anisotropy, the sub-1 nm building blocks have self-assembled into rhombic dodecahedral POM (RD-POM) assemblies at the microscale. Benefiting from the regular structure, Br- ions, and abundant active sites, the obtained RD-POM assemblies exhibit excellent catalytic performance in the cycloaddition of CO2 with epoxides without co-catalysts. This work provides a promising approach to tailor the symmetry and structure of sub-1 nm building blocks by tuning the spatial distribution of ligands, which may shed light on the fabrication of superstructures with novel properties by self-assembly.

Cyclin-dependent kinase 5 promotes the growth of tongue squamous cell carcinoma through the microRNA 513c-5p/cell division cycle 25B pathway and is associated with a poor prognosis.

BACKGROUND: The objective of this study was to investigate the role and molecular mechanism of cyclin-dependent kinase 5 (CDK5) in regulating the growth of tongue squamous cell carcinoma (TSCC). METHODS: The authors used multiple methods to detect the levels of CDK5 expression in samples of TSCC and to explore the relation between CDK5 expression and various clinicopathologic factors. In vivo and in vitro cell experiments were performed to detect the proliferation, invasion, and migration of TSCC cells with CDK5 knockdown or overexpression. These studies verified that CDK5 regulates the occurrence and development of TSCC cells through the microRNA 513c-5p/cell division cycle 25B pathway. RESULTS: An elevated level of CDK5 expression in TSCC tissues was identified as an independent risk factor affecting TSCC growth and patient prognosis. Patients who had TSCC with low levels of CDK5 expression had a higher survival rate than those with high levels. Knockdown of CDK5 reduced the proliferation, migration, and invasion of TSCC cells both in vitro and in vivo. In addition, the authors observed that CDK5 regulated the growth of TSCC through the microRNA 513c-5p/cell division cycle C25B pathway. CONCLUSIONS: CDK5 functions as an oncogene in TSCC and might serve as a molecular marker for use in the diagnosis and treatment of TSCC. LAY SUMMARY: Tongue squamous cell carcinoma (TSCC) is 1 of the most common malignant tumors of the head and neck, and the survival rate of patients with tongue cancer has been very low. Therefore, it is important to study the molecular mechanism of TSCC progression to identify biomarkers that can be used to improve its clinical diagnosis and treatment. Cyclin-dependent kinase 5 (CDK5) is an atypical member of the cyclin-dependent kinase family and is involved in regulating the cell cycle. Changes in the cell cycle are of great significance for the occurrence and development of tumor cells; and, in recent years, increasing evidence has suggested that CDK5 exists in a disordered state in cancer cells. In this study, the authors demonstrate that CDK5 functions as an oncogene in TSCC and might serve as a molecular marker for use in the diagnosis and treatment of TSCC.

Benefit of [18F]-FDG PET/CT for treatment-naïve nasopharyngeal carcinoma.

BACKGROUND: To test the advantages of positron emission tomography and computed tomography (PET/CT) for diagnosing lymph nodes and staging nasopharyngeal carcinoma and to investigate its benefits for survival and treatment decisions. METHODS: The performance of PET/CT and magnetic resonance imaging (MRI) in diagnosis was compared based on 460 biopsied lymph nodes. Using the propensity matching method, survival differences of T3N1M0 patients with (n = 1093) and without (n = 1377) PET/CT were compared in diverse manners. A radiologic score model was developed and tested in a subset of T3N1M0 patients. RESULTS: PET/CT performed better than MRI with higher sensitivity, accuracy, and area under the receiver operating characteristic curve (96.7% vs. 88.5%, p < 0.001; 88.0% vs. 81.1%, p < 0.001; 0.863 vs. 0.796, p < 0.05) in diagnosing lymph nodes. Accordingly, MRI-staged T3N0-3M0 patients showed nondifferent survival rates, as they were the same T3N1M0 if staged by PET/CT. In addition, patients staged by PET/CT and MRI showed higher survival rates than those staged by MRI alone (p < 0.05), regardless of the Epstein-Barr virus DNA load. Interestingly, SUVmax-N, nodal necrosis, and extranodal extension were highly predictive of survival. The radiologic score model based on these factors performed well in risk stratification with a C-index of 0.72. Finally, induction chemotherapy showed an added benefit (p = 0.006) for the high-risk patients selected by the model but not for those without risk stratification (p = 0.78). CONCLUSION: PET/CT showed advantages in staging nasopharyngeal carcinoma due to a more accurate diagnosis of lymph nodes and this contributed to a survival benefit. PET/CT combined with MRI provided prognostic factors that could identify high-risk patients and guide individualized treatment.

Organometallic Magnesium Complex with Aggregation Induced Emission Properties: Synthesis, Characterization, and Fluorescent Fibers Applications.

In this work, a novel organomagnesium complex with outstanding aggregation induced emission (AIE) properties is synthesized using dibenzoylmethane (DBM) as the ligand. The structure of the complex is confirmed to be one magnesium ion coordinated to the dione groups of two DBM molecules, and the magnesium ion adopts a distorted octahedrally geometry. The obvious emission is found for Mg(DBM)2 powder and not in the solution, making this the first reported organomagnesium complex with AIE property. The properties of the complex were investigated by using UV-vis absorption and fluorescence emission spectroscopy, cyclic voltammetry, and density functional theory calculations. Moreover, the Mg(DBM)2 solution dispersed in filter paper was is colorless, which may be made into a convenient anti-counterfeiting and encryption tool. Mg(DBM)2 /alginate fibers were prepared by wet-spinning process and further processed into paper, which can be used in the fields of sensors, anti-counterfeiting, and encryption. Sweat contains a wealth of chemical information that could potentially indicate the body's deeper biomolecular state. The prepared fluorescent fibers were used to detect sweat due to its non-toxic, low-cost efficient and fast response to analytes.

Fabrication of Chitosan-Loaded Multifunctional Wool Fabric for Reactive Dye Digital Inkjet Printing by Schiff Base Reaction.

Improving the development of high-value multifunctional wool fabrics was essential to satisfy diverse needs. Considering the various characteristics of chitosan macromolecules, herein, a padding-cross-linking process was adopted and then multifunctional wool fabrics with outstanding printing effects, shrink resistance, and antibacterial properties were fabricated. The test results showed that chitosan macromolecules loaded successfully on the wool fiber surface by Schiff base reaction. Wool fabrics changed from hydrophobic to hydrophilic due to the existence of chitosan macromolecules. The color strength (K/S value) of the reactive dye inkjet-printed wool fabric was greatly increased from 20.48 to 26.6. The area shrinkage of final samples was 2.53%, which was exceedingly lower than that of the original wool (10.96%). Moreover, the chitosan macromolecules with reactive amino groups endowed wool fabrics with certain antibacterial properties against E. coli and S. aureus. Generally, this study provided guidance for manufacturing multifunctional digital inkjet-printed wool products in mass production.

Screening the potential part of the G protein antigen is an achievable strategy to improve the immune effect of DNA vaccine against MSRV infection.

DNA vaccines, as an effective prophylactic technology to induce both humoral and cellular immune responses, have already been widely studied to prevent and control viral and bacterial infections in aquaculture. To find a more effective and safer way to control Micropterus salmoides rhabdovirus (MSRV) infection in largemouth bass, two different DNA vaccines expressing partial (pcDNA3.1-G2) and full-length (pcDNA3.1-G) of the MSRV G protein were developed and injected intramuscularly with different doses. The immune effect was comprehensively compared and evaluated by detecting immune-related parameters including serum antibody levels, immune-related physiological indexes, immune-related gene expression and relative survival rates in this study. The results showed that compared with the pcDNA3.1-G vaccine, the pcDNA3.1-G2 vaccine induced higher serum antibody levels, a lower nonspecific immune response in serum (ACP, SOD and T-AOC activities), higher immune-related gene expression and a higher relative survival rate. Moreover, the immune effect of pcDNA3.1-G2-vaccinated fish showed gradually higher with the increasing pcDNA3.1-G2 concentration, especially in pcDNA3.1-G2 (10µg/per fish) group, the relative survival rate reached to 82.5%, which was significant higher (p < 0.05) than pcDNA3.1-G (10µg/per fish) group. This study indicated that screening the potential core part of an antigen is an achievable strategy to improve the immunogenicity and immunoprotective effect of DNA vaccine.

Copper-Based Metal-Organic Framework with a Tetraphenylethylene-Tetrazole Linker for Visible-Light-Driven CO2 Photoconversion.

The design of efficient and inexpensive photocatalysts for CO2 photoreduction under visible light is of great significance for the sustainable development of the entire society. Herein, a copper-based metal-organic framework (MOF) (CUST-804) using a bulky tetraphenylethylene-tetrazole linker is synthesized and successfully used as a photocatalyst for CO2 reduction. The structural characterizations, as well as the photophysical properties, are investigated systematically. In the heterogeneous catalytic system, CUST-804 exhibits a robust CO production activity up to 2.71 mmol g-1 h-1 with excellent recyclability along with a selectivity of 82.8%, which is comparable with those of the reported copper-based MOF system. Theoretical calculations demonstrated that, among three kinds of coordinated model, only the 5-coordinated Cu site is active for CO2 reduction, in which the *COOH intermediate is stabilized and CO is readily desorbed. The results obtained herein can provide fresh insights into the realization of efficient copper-functionalized crystalline photocatalysts for CO2 reduction.

[Application of two noninvasive scores in predicting the risk of respiratory failure in full-term neonates: a comparative analysis]. / ä¸¤ç§æ— åˆ›è¯„åˆ†æ³•åœ¨è¶³æœˆæ–°ç”Ÿå„¿å‘¼å¸è¡°ç«­é£Žé™©é¢„æµ‹ä¸­çš„åº”ç”¨æ¯”è¾ƒ.

OBJECTIVES: To study the value of Silverman-Anderson score versus Downes score in predicting respiratory failure in full-term neonates. METHODS: The convenience sampling method was used to select the full-term neonates with lung diseases who were hospitalized in the neonatal intensive care unit from July 2020 to July 2021. According to the diagnostic criteria for neonatal respiratory failure, they were divided into a respiratory failure group (65 neonates) and a non-respiratory failure group (363 neonates). Silverman-Anderson score and Downes score were used for evaluation. The receiver operating characteristic analysis was used to compare the value of the two noninvasive scores in predicting respiratory failure in full-term neonates. RESULTS: Among the 428 full-term neonates, 65 (15.2%) had respiratory failure. The Silverman-Anderson score had a significantly shorter average time spent on evaluation than the Downes score [(90±8) seconds vs (150±13) seconds; P<0.001]. The respiratory failure group had significantly higher points in both the Silverman-Anderson and Downes scores than the non-respiratory failure group (P<0.001). The Silverman-Anderson score had an AUC of 0.876 for predicting respiratory failure, with a sensitivity of 0.908, a specificity of 0.694, and a Youden index of 0.602 at the optimal cut-off value of 4.50 points. The Downes score had an AUC of 0.918 for predicting respiratory failure, with a sensitivity of 0.723, a specificity of 0.953, and a Youden index of 0.676 at the optimal cut-off value of 6.00 points. The Downes score had significantly higher AUC for predicting respiratory failure than the Silverman-Anderson score (P=0.026). CONCLUSIONS: Both Silverman-Anderson and Downes scores can predict the risk of respiratory failure in full-term neonates. The Silverman-Anderson score requires a shorter time for evaluation, while the Downes score has higher prediction efficiency. It is recommended to use Downes score with higher prediction efficiency in general evaluation, and the Silverman-Anderson score requiring a shorter time for evaluation can be used in emergency.

Polyoxometalates-Based Semi-flexible Metal-Semiconductor Triboelectric Nanogenerators for Low Frequency and Small Amplitude Mechanical Energy Harvesting.

The development of high-performance and low-cost durable triboelectric nanogenerators (TENGs) is essential for converting mechanical energy into electrical energy. Many organic polymer friction materials used widely have thermal stability problems, which makes TENGs with semiconductors as friction materials stand out. Here, we report a semi-flexible TENG based on metal and TiO2 modified by polyoxometalates (POMs) as pure inorganic friction materials. Six different POMs are firstly selected to modify the friction materials of TENGs, and the output performance of TENGs with different POMs-modified semiconductors and different metals as friction materials are tested. Compared with the unmodified TENGs, the open-circuit voltage (VOC ) of the optimal Ag-K6 P2 Mo18 O62 (P2 Mo18 )/TiO2 TENG device is increased by more than 4 times, which is mainly attributed to the strong electron-accepting and storage capabilities of POMs. This study has demonstrated that TENGs modified by POMs have potential application prospects and provided a new method for increasing the electrical output of TENGs.

Effect of Diethylene Glycol on the Inkjet Printability of Reactive Dye Solution for Cotton Fabrics.

Digital inkjet printing technology plays an increasingly important role in textile printing. The printing printability of reactive dye inks is the key to improving the quality of printed fabrics. In this study, an eco-friendly and simple method to improve the inkjet printability of reactive dye solutions was proposed. The influence of diethylene glycol on the surface tension, rheology, and dye molecule aggregation properties for three reactive dye solutions was investigated. The jetting performance of dye solutions was explored by observing droplet formation. Moreover, the color performance of printed cotton fabrics, including reactive dye solution penetration, colorimetric values, and color strength, was evaluated. Addition of diethylene glycol could change the aggregation of dye molecules by hydrophobic forces and hydrogen bonds. Diethylene glycol could inhibit formation of satellite droplets by changing the viscosity and surface tension of solutions, which made the pattern printed on cotton fabrics show regular edge sharpness. Furthermore, the dye solutions containing 10% DEG not only satisfied various properties of reactive dye inks but also had the highest color strength and the deepest and brightest colors.

Navigating complexity: The importance of design-based research for faculty development.

Despite the importance of evidence-based medical education, navigating the complexity of its implementation can be frustrating. Faculty development that engages and supports medical educators in Design-Based Research is one promising approach to respond to this challenge. An essential aspect of this process is to expand faculty's Zone of Generativity and thus foster their individual and collective capabilities to navigate the complexity of implementing evidence-based medical education.

Twelve tips for conducting educational design research in medical education.

Despite a steady growth in educational innovations and studies investigating the acceptance and effectiveness of these innovations, medical education has not realized sufficient improvement in practice and outcomes from these investments. In light of this lack of impact, there has been a growing call for studies that more effectively bridge the gap between research and practice. This paper introduces Educational Design Research (EDR) as a promising approach to address this challenge. Twelve tips are provided to inspire and guide medical educators to conduct EDR to achieve the dual goals of tackling a significant educational problem in a specific context while at the same time advancing the theoretical knowledge that may be used to improve practice elsewhere.

Systematically Exploring Molecular Aggregation and Its Impact on Surface Tension and Viscosity in High Concentration Solutions.

The aggregation structure of dye molecules has a great influence on the properties of dye solutions, especially in high concentration. Here, the dye molecular aggregation structures were investigated systemically in aqueous solutions with high concentration using three reactive dyes (O-13, R-24:1 and R-218). O-13 showed stronger aggregation than R-24:1 and R-218. This is because of the small non-conjugate side chain and its ß-linked position on the naphthalene of O-13. Compared with R-218, R-24:1 showed relatively weaker aggregation due to the good solution of R-24:1. The change of different aggregate distributions in the solutions were also investigated by splitting the absorption curves. Moreover, it is found that the surface tension of solutions can be modified by the combined effect of both aggregation and the position of the hydrophilic group, which, however, also have an effect on viscosity. This exploration will provide guidance for the study of high concentration solutions.