Room-Temperature Formation of CdTeSe Magic-Size Clusters from Oleate-Capped CdTe Precursor Compounds via CdSe Monomer Substitution.

We report the first room-temperature synthesis of ternary CdTeSe magic-size clusters (MSCs) that have mainly the surface ligand oleate (OA). The MSCs display sharp optical absorption peaking at ∼399 nm and are thus referred to as MSC-399. They are made from prenucleation-stage samples of binary CdTe and CdSe, which are prepared by two reactions in 1-octadecene (ODE) of cadmium oleate (Cd(OA)2) and tri-n-octylphosphine chalcogenide (ETOP, E = Te and Se) at 25 °C for 120 min and 80 °C for 15 min, respectively. When the two binary samples are mixed at room temperature and dispersed in a mixture of toluene (Tol) and octylamine (OTA), the CdTeSe MSC-399 develops. Also, when the CdSe sample is added to CdTe MSC-371 in a dispersion, the transformation from CdTe MSC-371 to CdTeSe MSC-399 is seen. We propose that the MSCs develop from their precursor compounds (PCs) that are relatively transparent in optical absorption, such as CdTeSe MSC-399 from CdTeSe PC-399 and CdTe MSC-371 from CdTe PC-371. The formation of CdTeSe PC-399 undergoes monomer substitution and not anion exchange, which is the reaction of CdTe PC-371 and the CdSe monomer to produce CdTeSe PC-399 and the CdTe monomer. Our study provides evidence of monomer substitution for the transformation from binary CdTe to ternary CdTeSe PCs.

A dual-response ratiometric fluorescent sensor by europium-doped silicon nanoparticles for fluorescent and smartphone imaging detection of tetracycline.

Given the threat to human health posed by the abuse of tetracycline (TC), the development of a portable, on-site methods for highly sensitive and rapid TC detection is crucial. In this work, we initially synthesized europium-doped silicon nanoparticles (SiEuNPs) through a facile one-pot microwave-assisted method. Due to its blue-red dual fluorescence emission (465 nm/627 nm), which was respectively attributed to the silicon nanoparticles and Eu3+, SiEuNPs were designed as a ratiometric fluorescent sensor for TC detection. For the dual-signal reverse response mechanism: TC quenched the blue emission from silicon nanoparticles through inner filter effect (IFE), and enhanced the red emission through "antenna effect" (AE) between TC and Eu3+, the nanoprobe was able to detect TC within a range of 0.2-10 µM with a limit of detection (LOD) of 10.7 nM. Notably, the equilibrium detection time was only 1 min, achieving rapid TC detection. Furthermore, TC was also measured in real samples (tap water, milk and honey) with recoveries ranging from 95.7 % to 117.0 %. More importantly, a portable smartphone-assisted on-site detection platform was developed, enabling real-time qualitative identification and semi-quantitative analysis of TC based on fluorescence color changes. This work not only provided a novel doped silicon nanoparticles strategy, but also constructed a ratiometric sensing platform with dual-signal reverse response for intuitive and real-time TC detection.

Lower-Temperature Nucleation and Growth of Colloidal CdTe Quantum Dots Enabled by Prenucleation Clusters with Cd-Te Bond Conservation.

The reason why heating is required remains elusive for the traditional synthesis of colloidal semiconductor quantum dots (QDs) of II-VI metal chalcogenide (ME). Using CdTe as a model system, we show that the formation of Cd-Te covalent bonds with individual Cd- and Te-containing compounds can be decoupled from the nucleation and growth of CdTe QDs. Prepared at an elevated temperature, a prenucleation-stage sample contains clusters that are the precursor compound (PC) of magic-size clusters (MSCs); the Cd-Te bond formation occurs at temperatures higher than 120 °C in the reaction. Afterward, the PC-to-QD transformation appears via monomers at lower temperatures in dispersion. Our findings suggest that the number of Cd-Te bonds broken in the PC reactant is similar to that of Cd-Te bonds formed in the QD product. For the traditional synthesis of ME QDs, heating is responsible for the M-E bond formation rather than for nucleation.

Enantioselective copper-catalyzed B-H bond insertion reaction of α-diazo phosphonates to access chiral α-boryl phosphonates.

Chiral phosphorus-containing compounds find applications across various fields, including asymmetric catalysis, medicinal chemistry, and materials science. Despite the abundance of reported highly enantioselective methods for synthesizing various chiral phosphorus compounds, the enantioselective synthesis of α-boryl phosphorus compounds still remains an unknown territory. Here, we report a method for the construction of chiral α-boryl phosphates by asymmetric B-H insertion reaction using α-diazo phosphates as carbene precursors, cheap and readily available copper salt as the catalyst and chiral oxazoline as the ligand. This method can directly afford a series of stable α-boryl phosphates with a yield up to 97% and an enantioselectivity up to 98% ee. The operating procedure of this method is straightforward, offering a broad substrate applicability, remarkable tolerance towards various functional groups, and gentle reaction conditions.

Pathway of Room-Temperature Formation of CdSeS Magic-Size Clusters from Mixtures of CdSe and CdS Samples.

The synthetic application of prenucleation-stage samples of colloidal semiconductor quantum dots (QDs) is in its infancy. It is shown that when two prenucleation-stage samples of binary CdSe and CdS are mixed, ternary CdSeS magic-size clusters (MSCs) grow at room temperature in dispersion. As the amount of the CdS sample increases, the optical absorption of the CdSeS MSCs blueshifts from ≈380 to ≈360 nm. It is proposed that the cluster in the CdSe sample reacts with the CdS monomer from the CdS sample. The monomer substitution reaction of CdSe by CdS can proceed continuously; thus, CdSeS MSCs with tunable compositions are obtained. The present study provides compelling evidence that clusters formed in the prenucleation stage of QDs. The clusters are precursor compounds (PCs) of MSCs, transforming at room temperature with the thermoneutrality principle of isodesmic reactions. The nucleation and growth of QDs follows a multi-step non-classical instead of one-step classical nucleation model.

Research on mechanical properties of concrete by nano-TiC-BF-fly ash.

Ultra-high-rise buildings require high concrete bearing capacity. Ordinary concrete often fails to meet the project requirements. Admixture of admixtures in concrete is a means of solution. Currently, studies on the incorporation of basalt fiber (BF) and fly ash (FA) in concrete are relatively mature. However, research on incorporating nano-Titanium Carbide (nano-TiC) in concrete is still relatively scarce, which has a lot of room for development. To further improve the mechanical properties of concrete, BF, and FA synergized with nano-TiC were incorporated into concrete to produce TBF concrete in this study. And Response Surface Methodology (RSM) was used to optimize the mechanical properties of concrete. The collapse and compressive deformation damage characteristics of concrete were analyzed. The microstructure of the cement matrix was analyzed by the SEM (Scanning Electron Microscope). An optimization model of the TBF concrete craving function was developed. Optimized ratios with compressive, split tensile, and flexural strengths as response objectives were obtained, and the accuracy of the optimized ratios was investigated using the same experimental conditions. The results of the study showed that FA increased the collapse of concrete, while nano-TiC and BF decreased the collapse of concrete. Under uniaxial compression, nano-TiC, FA, and BF together incorporated into concrete can improve its compressive damage state. Moderate amounts of nano-TiC, BF, and FA could improve the mechanical properties of concrete. Their optimal mixing ratio admixtures were 0.88%, 0.24%, and 5.49%, respectively. And the measured values under the same conditions were compared with the predicted values. The maximum difference in compressive strength was 6.09%. The maximum difference in split tensile strength was 7.14%. The maximum difference in flexural strength was 8.45%. This indicated that the accuracy of the RSM optimization model was good. A moderate amount of nano-TiC, FA, and BF could improve the densification of concrete.

Formation and Transformation of CdS Clusters during the Prenucleation Stage and in a Dilute Dispersion at Room Temperature.

The formation and transformation of colloidal semiconductor clusters remain poorly understood. With CdS as a model system, we show that, in the reaction of cadmium myristate (Cd(MA)2) and S powder in 1-octadecene (ODE), clusters form in the prenucleation stage of quantum dots (QDs). Called precursor compounds (PCs), the clusters can transform to magic-size clusters (MSCs) in reaction at a relatively high temperature (MSC-322 displaying optical absorption peaking at 322 nm) or in a dispersion at room temperature (MSC-360). When the reaction temperature is increased, PC-360 forms at 140 °C, while PC-322 and MSC-322 form at 180 °C. In a dispersion of cyclohexane and octylamine, MSC-322 transforms to MSC-360 via MSC-345. The MSC-345 to MSC-360 transformation displays continuous and discontinuous shifts in the optical absorption. The PCs and MSCs are a group of isomers. The present findings bring insight into the cluster formation and isomerization in the prenucleation stage of QDs and in a dispersion.

Inulin alleviates perfluorooctanoic acid-induced intestinal injury in mice by modulating the PI3K/AKT/mTOR signaling pathway.

Perfluorooctanoic acid (PFOA) is a widely used industrial compound that has been found to induce intestinal toxicity. However, the underlying mechanisms have not been fully clarified and effective interventions are rarely developed. Inulin, a prebiotic, has been used as a supplement in human daily life as well as in gastrointestinal diseases and metabolic disorders. In this study, male mice were exposed to PFOA with or without inulin supplementation to investigate the enterotoxicity and potential intervention effects of inulin. Mice were administered PFOA at 1 mg/kg/day, PFOA with inulin at 5 g/kg/day, or Milli-Q water for 12 weeks. Histopathological analysis showed that PFOA caused colon shortening, goblet cell reduction, and inflammatory cell infiltration. The expression of the tight junction proteins ZO-1, occludin and claudin5 significantly decreased, indicating impaired barrier function. According to the RNA-sequencing analysis, PFOA exposure resulted in 917 differentially expressed genes, involving 39 significant pathways, such as TNF signaling and cell cycle pathways. In addition, the protein expression of TNF-α, IRG-47, cyclinB1, and cyclinB2 increased, while Gadd45γ, Lzip, and Jam2 decreased, suggesting the involvement of the TNF signaling pathway, cell cycle, and cell adhesion molecules in PFOA-associated intestinal injury. Inulin intervention alleviated PFOA-induced enterotoxicity by activating the PI3K/AKT/mTOR signaling pathway and increasing the protein expression of Wnt1, ß-catenin, PI3K, Akt3, and p62, while suppressing MAP LC3ß, TNF-α, and CyclinE expression. These findings suggested that PFOA-induced intestinal injury, including inflammation and tight junction disruption, was mitigated by inulin through modifying the PI3K/AKT/mTOR signaling pathways. Our study provides valuable insights into the enterotoxic effects of PFOA and highlights the potential therapeutic role of inulin.

Extracellular and intracellular effects of bioactive glass nanoparticles on osteogenic differentiation of bone marrow mesenchymal stem cells and bone regeneration in zebrafish osteoporosis model.

Bioactive glass nanoparticles (BGNs) are well-recognized multifunctional biomaterials for bone tissue regeneration due to their capability to stimulate various cellular processes through released biologically active ions. Understanding the correlation between BGN composition and cellular responses is key to developing clinically usable BGN-based medical devices. This study investigated the influence of CaO content of binary SiO2-CaO BGNs (CaO ranging from 0 to 10 mol%) on osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) and in vivo bone regeneration in zebrafish osteoporosis model. The results showed that BGNs could promote osteogenic differentiation of rBMSCs by indirectly releasing active ions or directly interacting with rBMSCs by internalization. In both situations, BGNs of a higher CaO content could promote the osteogenic differentiation of rBMSCs to a greater extent. The internalized BGNs could activate the transcription factors RUNX2 and OSX, leading to the expression of osteogenesis-related genes. The results in the zebrafish osteoporosis model indicated that the presence of BGNs of higher CaO contents could enhance bone regeneration and rescue dexamethasone-induced osteoporosis to a greater extent. These findings demonstrate that BGNs can stimulate osteogenic differentiation of rBMSCs by releasing active ions or internalization. A higher CaO content facilitates osteogenesis and bone regeneration of zebrafish as well as relieving dexamethasone-induced osteoporosis. The zebrafish osteoporosis model can be a potent tool for evaluating the in vivo bone regeneration effects of bioactive materials. STATEMENT OF SIGNIFICANCE: Bioactive glass nanoparticles (BGNs) are increasingly used as fillers of nanocomposites or as delivery platforms of active ions to regenerate bone tissue. Various studies have shown that BGNs can enhance osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by releasing active ions. However, the correlation between BGN composition and cellular responses and in vivo bone regeneration effect has still not been well investigated. Establishment of a suitable in vivo animal model for investigating this correlation is also challenging. The present study reports the influence of CaO content in binary SiO2-CaO BGNs on osteogenic differentiation of BMSCs extracellularly and intracellularly. This study also demonstrates the suitability of zebrafish osteoporosis model to investigate in vivo bone regeneration effect of BGNs.

Surface-Ligand Tuned Reversible Transformations in Aqueous Environments Between CdSe Magic-Size Clusters and Their Precursor Compounds.

That magic-size clusters (MSCs) have their counterpart precursor compounds (PCs) has not been generally accepted by expertise circles. Here, experimental evidence to support this new concept is presented. With aqueous-phase CdSe MSCs as a model system, it is shown that when the MSCs are dispersed in water containing a certain amount of L-cysteine (Cys), the MSCs disappear slowly. Upon the addition of CdCl2 , the MSCs recover. It is proposed that after dispersing, the MSCs transform to their quasi-isomeric, non-absorbing PCs upon Cys addition. In the presence of CdCl2 , the PCs transform back to the MSCs due to Cys elimination. The surface ligand Cys of the MSCs plays a significant role in the reversible transformations. The present study provides compelling evidence that absorbing MSCs have their non-absorbing PCs. The study findings suggest that the transformation between two MSCs that display absorption spectral shifts in a stepwise pattern is assisted by their PCs.

Precursor Compound-Assisted Formation of CdS Magic-Size Clusters in Aqueous Solutions.

Investigations of the formation pathway of semiconductor magic-size clusters (MSCs) in aqueous solutions are quite limited. Here, we present our understanding about a precursor compound (PC)-assisted formation pathway of aqueous-phase CdS MSCs exhibiting a characteristic absorption peak at about 360 nm (MSC-360). The reaction uses CdCl2 as the Cd source and thioglycolic acid (TGA) as both the S source and ligand in alkaline aqueous solutions. The mixture remains absorption featureless upon incubation at room temperature but with MSC-360 absorption observed upon adding butylamine. The longer the incubation period of the aqueous solution, the more MSC-360 forms after adding butylamine. We propose that Cd-TGA complexes form first, in which the TGA moieties then decompose partially to form PC of MSC-360 (PC-360) that cannot be observed in the optical absorption spectrum. The resulting PC-360 transforms to MSC-360 via quasi-isomerization in the presence of butylamine. The present study provides an in-depth understanding about the formation of aqueous-phase MSCs.

Sustainable development, eco-tourism carrying capacity and fuzzy algorithm-a study on Kanas in Belt and Road.

In this paper, the method of fuzzy pattern recognition is adopted in more precisely evaluating the actual state of eco-tourism development regarding a given tourist destination in comparison with the three standard patterns (saturated/optimal/deficient) of development degree. The research process is as follows: Firstly, the indictors of carrying capacity of a tourist destination and the corresponding measuring factors are established; secondly, an assessment group is recruited to work out the most constraining factors among the measuring factors; thirdly, by means of field survey, numerical values of the actual state are acquired; fourthly, there comes out the membership vectors and the membership matrix of the standard patterns corresponding to the vectors of three standard patterns, threshold and the actual state; Finally, it could be identified which standard pattern that the actual state is closest to via the lattice degrees of proximity. An exemplary case study on Kanas National Nature Reserves is attached to the logic calculus. This paper is contributed to dynamically monitor the threshold of tourism carrying capacity and precisely identify which carrying capacity (spatial resource/ecological environment/economic resources/people's psychology/socio-culture) with potential risks.

Thermally-Induced Isomerization of Prenucleation Clusters During the Prenucleation Stage of CdTe Quantum Dots.

The evolution of prenucleation clusters in the prenucleation stage of colloidal semiconductor quantum dots (QDs) has remained unexplored. With CdTe as a model system, we show that substances form and isomerize prior to the nucleation and growth of QDs. Called precursor compounds (PCs), the prenucleation clusters are relatively optically transparent and can transform to absorbing magic-size clusters (MSCs). When a prenucleation-stage sample at 25, 45, or 80 °C is dispersed in a mixture of cyclohexane (CH) and octylamine (OTA) at room temperature, either MSC-371, MSC-417, or MSC-448 evolves with absorption peaking at 371, 417, or 448 nm, respectively. We propose that PC-371 forms at 25 °C, and isomerizes to PC-417 at 45 °C and to PC-448 at 80 °C. The PCs and MSCs are quasi isomers. Relatively large and small amounts of OTA favor PC-371 and PC-448 in dispersion, respectively. The present findings suggest the existence of PC-to-PC isomerization in the QD prenucleation stage.

Preparation of Ce-MnOx Composite Oxides via Coprecipitation and Their Catalytic Performance for CO Oxidation.

Ce-MnOx composite oxide catalysts with different proportions were prepared using the coprecipitation method, and the CO-removal ability of the catalysts with the tested temperature range of 60-140 °C was investigated systematically. The effect of Ce and Mn ratios on the catalytic oxidation performance of CO was investigated using X-ray diffraction (XRD), X-ray energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), H2 temperature programmed reduction (H2-TPR), CO-temperature programmed desorption (CO-TPD), and in situ infrared spectra. The experimental results reveal that under the same test conditions, the CO conversion rate of pure Mn3O4 reaches 95.4% at 170 °C. Additionally, at 140 °C, the Ce-MnOx series composite oxide catalyst converts CO at a rate of over 96%, outperforming single-phase Mn3O4 in terms of catalytic performance. With the decrement in Ce content, the performance of Ce-MnOx series composite oxide catalysts first increase and then decrease. The Ce MnOx catalyst behaves best when Ce:Mn = 1:1, with a CO conversion rate of 99.96% at 140 °C and 91.98% at 100 °C.

Adaptive Prototype Interaction Network for Few-Shot Knowledge Graph Completion.

Few-shot knowledge graph completion (FKGC), which aims to infer new triples for a relation using only a few reference triples of the relation, has attracted much attention in recent years. Most existing FKGC methods learn a transferable embedding space, where entity pairs belonging to the same relations are close to each other. In real-world knowledge graphs (KGs), however, some relations may involve multiple semantics, and their entity pairs are not always close due to having different meanings. Hence, the existing FKGC methods may yield suboptimal performance when handling multiple semantic relations in the few-shot scenario. To solve this problem, we propose a new method named adaptive prototype interaction network (APINet) for FKGC. Our model consists of two major components: 1) an interaction attention encoder (InterAE) to capture the underlying relational semantics of entity pairs by modeling the interactive information between head and tail entities and 2) an adaptive prototype net (APNet) to generate relation prototypes adaptive to different query triples by extracting query-relevant reference pairs and reducing the data inconsistency between support and query sets. Experimental results on two public datasets demonstrate that APINet outperforms several state-of-the-art FKGC methods. The ablation study demonstrates the rationality and effectiveness of each component of APINet.

Mitochondria-Targeted Thymidylate Synthase Inhibitor Based on Fluorescent Molecularly Imprinted Polymers for Tumor Antimetabolic Therapy.

Antimetabolites targeting thymidylate synthase (TS), such as 5-fluorouracil and capecitabine, have been widely used in tumor therapy in the past decades. Here, we present a strategy to construct mitochondria-targeted antimetabolic therapeutic nanomedicines based on fluorescent molecularly imprinted polymers (FMIP), and the nanomedicine was denoted as Mito-FMIP. Mito-FMIP, synthesized using fluorescent dye-doped silica as the carrier and amino acid sequence containing the active center of TS as the template peptide, could specifically recognize and bind to the active site of TS, thus inhibiting the catalytic activity of TS, and therefore hindering subsequent DNA biosynthesis, ultimately inhibiting tumor growth. The imprinting factor of FMIP reached 2.9, and the modification of CTPB endowed Mito-FMIP with the ability to target mitochondria. In vitro experiments demonstrated that Mito-FMIP was able to efficiently aggregate in mitochondria and inhibit CT26 cell proliferation by 59.9%. The results of flow cytometric analysis showed that the relative mean fluorescence intensity of Mito-FMIP accumulated in the mitochondria was 3.4-fold that of FMIP. In vivo experiments showed that the tumor volume of the Mito-FMIP-treated group was only one third of that of the untreated group. In addition, Mito-FMIP exibited the maximum emission wavelength at 682 nm, which allowed it to be used for fluorescence imaging of tumors. Taken together, this study provides a new strategy for the construction of nanomedicines with antimetabolic functions based on molecularly imprinted polymers.

Biomaterials promote in vivo generation and immunotherapy of CAR-T cells.

Chimeric antigen receptor-T (CAR-T) cell therapy based on functional immune cell transfer is showing a booming situation. However, complex manufacturing processes, high costs, and disappointing results in the treatment of solid tumors have limited its use. Encouragingly, it has facilitated the development of new strategies that fuse immunology, cell biology, and biomaterials to overcome these obstacles. In recent years, CAR-T engineering assisted by properly designed biomaterials has improved therapeutic efficacy and reduced side effects, providing a sustainable strategy for improving cancer immunotherapy. At the same time, the low cost and diversity of biomaterials also offer the possibility of industrial production and commercialization. Here, we summarize the role of biomaterials as gene delivery vehicles in the generation of CAR-T cells and highlight the advantages of in-situ construction in vivo. Then, we focused on how biomaterials can be combined with CAR-T cells to better enable synergistic immunotherapy in the treatment of solid tumors. Finally, we describe biomaterials' potential challenges and prospects in CAR-T therapy. This review aims to provide a detailed overview of biomaterial-based CAR-T tumor immunotherapy to help investigators reference and customize biomaterials for CAR-T therapy to improve the efficacy of immunotherapy.

Direct and Indirect Evolution of Photoluminescent Semiconductor CdS Magic-Size Clusters through Their Precursor Compounds.

Colloidal semiconductor II-VI metal chalcogenide (ME) magic-size clusters (MSCs) exhibit either an optical absorption singlet or doublet. In the latter case, a sharp photoluminescence (PL) signal is observed. Whether the PL-inactive MSCs transform to the PL-active ones is unknown. We show that PL-inactive CdS MSC-322 transforms to PL-active CdS MSC-328 and MSC-373 in the presence of acetic acid (HOAc). MSC-322 displays a sharp absorption at ≈322 nm, whereas MSC-328 and MSC-373 both have broad absorptions respectively around 328 and 373 nm. In a reaction of cadmium myristate and S powder in 1-octadecene, MSC-322 develops; with HOAc, MSC-328 and MSC-373 are present. We propose that the MSCs evolve from their relatively transparent precursor compounds (PCs). The PC-322 to PC-328 quasi-isomerization involves monomer substitution, while monomer addition occurs for the PC-328 to PC-373 transformation. Our findings suggest that S dominates the precursor self-assembly quantitatively, and ligand-bonded Cd mainly controls MSC optical properties.