Assembling colloidal particles using site-selective directional interactions into predetermined colloidal superlattices with desired properties is broadly sought after, but challenging to achieve. ...Herein, we exploit regioselective depletion interactions to engineer the directional bonding and assembly of non-spherical colloidal hybrid microparticles. We report that the crystallization of a binary colloidal mixture can be regulated by tuning the depletion conditions. Subsequently, we fabricate triblock biphasic colloids with controlled aspect ratios to achieve regioselective bonding. Without any surface treatment, these biphasic colloids assemble into various colloidal superstructures and superlattices featuring optimized pole-to-pole or centre-to-centre interactions. Additionally, we observe polymorphic crystallization, quantify the abundancy of each form using algorithms we developed and investigate the crystallization process in real time. We demonstrate selective control of attractive interactions between specific regions on an anisotropic colloid with no need of site-specific surface functionalization, leading to a general method for achieving colloidal structures with yet unforeseen arrangements and properties.
Abstract
Bacteria can bypass the blood-brain barrier (BBB), suggesting the possibility of employment of bacteria for combating central nervous system diseases. Herein, we develop a bacteria-based ...drug delivery system for glioblastoma (GBM) photothermal immunotherapy. The system, which we name as ‘Trojan bacteria’, consists of bacteria loaded with glucose polymer and photosensitive ICG silicon-nanoparticles. In an orthotopic GBM mouse model, we demonstrate that the intravenously injected bacteria bypass the BBB, targeting and penetrating GBM tissues. Upon 808 nm-laser irradiation, the photothermal effects produced by ICG allow the destruction of bacterial cells and the adjacent tumour cells. Furthermore, the bacterial debris as well as the tumour-associated antigens promote antitumor immune responses that prolong the survival of GBM-bearing mice. Moreover, we demonstrate the residual bacteria are effectively eliminated from the body, supporting the potential therapeutic use of this system.
•Groundwater quality in Pinggu basin was evaluated.•Single-parameter and comprehensive outliers detection were combined.•Pre-selection, median ±2MAD, and Grubbs’ test were used to identify ...outliers.•δ15N-NO3− and δ18O-NO3− were used to analyze the sources of nitrate in groundwater.•Sewage, landfill, and industrial-agricultural activities dominated the pollution.
The assessment of natural background levels (NBLs) in groundwater is considered as an efficient way to distinguish the geogenic compound from anthropogenic pollution of groundwater—a basic issue in groundwater environmental management. At present, most studies only assess NBLs of single parameters in groundwater. Such method, however, ignored the complex components and interaction in the groundwater, which leads to the inaccuracy of the assessment. In this study, 51 groundwater samples were investigated in November 2018 in Pinggu basin—one of the most important emergency groundwater supply sources of Beijing. Hierarchical cluster analysis (HCA) was used firstly to divide the study area into four zones. By combining single-parameter NBLs assessment and comprehensive NBLs assessment, the possible anthropogenic impact on groundwater quality in different zones could be determined with the use of land use map. For single-parameter NBLs assessment, iterative Grubbs’ test was used to assess NBLs of the data following Gaussian distribution, and the median plus/minus twofold the median of the absolute deviations from the median (median ± 2MAD) method was used to assess NBLs of the data for the non-Gaussian distribution. For comprehensive NBLs assessment, Mahalanobis distances of scatters in scatter plots which express the hydrogeological evolution processes were involved. In addition, δ15N-NO3− and δ18O-NO3− were used to analyze the sources of nitrate in groundwater. The results showed that the groundwater was affected by industrial activities, agricultural activities, urban domestic sewage and landfills. And the groundwater quality in the east of the study area was better than that in the west. Nitrate in the groundwater of study area mainly came from nitrification, and denitrification occurred in the groundwater near the landfills. This study provides a way to assess the NBLs of groundwater quality, and to determine sources and transformation of nitrate in the groundwater, which contributes to the identification of anthropogenic pollution in groundwater.
While lithium hexafluorophosphate (LiPF6) still prevails as the main conducting salt in commercial lithium-ion batteries, its prominent disadvantage is high sensitivity toward water, which produces ...highly corrosive HF that degrades battery performance. The hydrolysis mechanism and its correlation with high voltage in the battery environment remain poorly understood, despite the wide application of high voltage cathode. In this work, combining theoretical and experimental approaches, we identified the direct reaction between H2O and PF6 – as main source of HF based on the preferential solvation of PF6 – anion by water and the low energy barrier for the decomposition of PF6 ––H2O complex. Such a hydrolysis process would be accelerated by high voltage the electrolytes face at the cathode side. This important clarification of electrolyte failure mechanism points us to design more effective mitigation strategies with the purpose of stabilizing LiPF6-based electrolytes for high voltage LIBs.
To improve the utilization of fertilizer and water resource at the same time, a new type chitosan-coated nitrogen, phosphorus and potassium compound fertilizer with controlled-release and ...water-retention (CFCW) was prepared, which possessed the three-layer structure. Its core was water-soluble nitrogen, phosphorus and potassium (NPK) fertilizer granular, the inner coating was chitosan (CTS), and the outer coating was poly(acrylic acid-co-acrylamide) (P(AA-co-AM)) superabsorbent polymer. Atomic absorption spectrophotometer and element analysis results showed that the product contained 7.98% potassium (shown by K
2O), 8.14% phosphorus (shown by P
2O
5), and 8.06% nitrogen. The synthesis conditions of inversion suspension polymerization were studied systematically. The water absorbency of the product was 70 times its own weight if it was allowed to swell in tap water at room temperature for 90
min. The nutrients slow release behaviors of the CFCW in soil and water-retention capacity of the soil with CFCW were investigated. A possible slow release mechanism was proposed and the release rate factor
K and the release exponent
n of nutrients in CFCW was calculated. This product with good controlled-release and water-retention capacity, being degradable in soil and environment-friendly, could be especially useful in agricultural and horticultural applications.
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•Fe3O4 was facilely modified by distillation-precipitation polymerization.•Reversible addition-fragmentation chain transfer agent was linked by click chemistry.•The MIPs shell was ...formed by controlled/“living” radical polymerization.•The obtained materials exhibit obvious molecular imprinting effects towards TBBPA.•The obtained materials exhibited magnetic responsiveness and excellent reusability.
A well-defined molecularly imprinted polymer nanospheres with excellent specific recognition ability was prepared on Fe3O4 nanoparticles via the combination of click chemistry and surface-initiated reversible addition−fragmentation chain transfer (RAFT) polymerization and using Tetrabromobisphenol A as template. Concretely, Fe3O4 nanoparticles were prepared by solvothermal method and then modified by 4-vinylbenylchloride through distillation-precipitation, which makes azide groups easily introduced on the surface of magnetic nanoparticles to form the relatively large amount of benzyl chloride groups. With high efficiency, alkyne terminated RAFT chain transfer agent were then immobilized onto the surface of Fe3O4 by means of click chemistry, which is Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC). The highly uniform imprinted thin film was finally fabricated on the surface of RAFT agent modified Fe3O4 nanoparticles. The binding results demonstrated that as-prepared imprinted beads exhibited remarkable molecular imprinting effects to the template molecule, fast rebinding kinetics and an excellent selectivity to compounds with similar configuration.
To sustain the further world population, more fertilizers are required, which may become an environmental hazard, unless adequate technical and socioeconomic impacts are addressed. In the current ...study, slow-release formulations of nitrogen fertilizer were developed on the basis of natural attapulgite (APT) clay, ethylcellulose (EC) film, and sodium carboxymethylcellulose/hydroxyethylcellulose (CMC/HEC) hydrogel. The structural and chemical characteristics of the product were examined. The release profiles of urea, ammonium sulfate, and ammonium chloride as nitrogen fertilizer substrates were determined in soil. To further compare the release profiles of nitrogen from different fertilizer substrates, a mathematical model for nutrient release from the coated fertilizer was applied to calculate the diffusion coefficient D. The influence of the product on water-holding and water-retention capacities of soil was determined. The experimental data indicated that the product can effectively reduce nutrient loss, improve use efficiency of water, and prolong irrigation cycles in drought-prone environments.
The objective of this study is to explore the value of two-dimensional (2D) and three-dimensional (3D) radiomics models based on enhanced computed tomography (CT) images in predicting BRCA gene ...mutations in patients with epithelial ovarian cancer.
The clinical and imaging data of 106 patients with ovarian cancer confirmed by surgery and pathology were retrospectively analyzed and genetic testing was performed. Radiomics features extracted from the 2D and 3D regions of interest of the patients' primary tumor lesions were selected in the training set using the maximum correlation and minimum redundancy method. Then, the best features were selected through Lasso tenfold cross-validation. Feature subsets were employed to establish a radiomics model. The model's performance was evaluated via area under the receiver operating characteristic curve analysis and its clinical validity was assessed by using the model's decision curve.
On the validation set, the area under the curve values of the 2D, 3D, and 2D + 3D combined models were 0.78 (0.61-0.96), 0.75 (0.55-0.92), and 0.82 (0.61-0.96), respectively. However, the DeLong test P values between the three pairs of models were all > 0.05. The decision curve analysis showed that the radiomics model had a high net benefit across all high-risk threshold probabilities.
The three radiomics models can predict the BRCA gene mutation in ovarian cancer, and there were no statistically significant differences between the prediction performance of the three models.
A double-coated slow-release NPK compound fertilizer with superabsorbent and water-retention was prepared by crosslinked poly(acrylic acid)/diatomite – containing urea (the outer coating), chitosan ...(the inner coating), and water-soluble granular fertilizer NPK (the core). The effects of the amount of crosslinker, initiator, degree of neutralization of acrylic acid, initial monomer and diatomite concentration on water absorbency were investigated and optimized. The water absorbency of the product was 75 times its own weight if it was allowed to swell in tap water at room temperature for 2
h. Atomic absorption spectrophotometer and element analysis results showed that the product contained 8.47% potassium (shown by K
2O), 8.51% phosphorus (shown by P
2O
5), and 15.77% nitrogen. We also investigated the water-retention property of the product and the slow release behavior of N, P and K in the product. This product with excellent slow release and water-retention capacity, being nontoxic in soil and environment-friendly, could be especially useful in agricultural and horticultural applications.
A slow-release membrane-encapsulated urea fertilizer with a superabsorbent and moisture preservation was prepared by cross-linked starch (the first layer), acrylic acid (AA) and acrylamide (the ...second layer; AM), ammonia, borax, urea, and so on. The variable affecting the water absorbency was investigated and optimized. The water absorbency of the product was 80 times its own weight if it was allowed to swell in tap water at room temperature for 80 min. Elemental analysis results showed that the product contained 26.74% nitrogen. The water retention property of the product and the slow-release behavior of nitrogen in the product were also investigated, and the results showed that the product not only had good slow-release property but also excellent water retention capacity. This will efficiently improve the utilization of fertilizer and water resources at the same time.
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