A pH-responsive nanoplatform, hydroxylated mesoporous nanosilica (HMNS) coated by polyethylenimine (PEI) coupled with gadolinium and folic acid (FA) (Gd-FA-Si), was designed to deliver anticancer drug targeting and to promote contrast effect for tumor cells using magnetic resonance (MR) spectrometer. Doxorubicin (DOX) was chosen as the anticancer drug and loaded into nanopores of HMNS, then its release in simulated body fluid could be controlled through adjusting the pH. This nanoplatform could significantly enhance the MR contrast effect, and the highest theoretical relaxivity per nanoplatform could even be approximately 1.28 × 106 mm–1s–1 because of the high Gd payload (2.61 × 105 per nanoplatform). The entire system possessed a high targeting performance to Hela and MDA-MB-231 cells because the FA located in the system could specifically bind to the folate–receptor sites on the surface of cell. Compared with free DOX, the nanoplatform presented a higher cell inhibition effect on the basis of cell assay. Therefore, this nanoplatform could be potentially applied as a tumor-targeted T1 MR contrast agent and pH-sensitive drug carrier system.Keywords: Gd-DTPA and folic acid; hydroxylated mesoporous nanosilica; MR contrast agent; polyethylenimine; targeted drug delivery system;

A facile approach to remediate the microenvironment of saline–alkali soil (SS) was developed using a novel fertilizer named saline–alkali soil remediating fertilizer (SSRF). SSRF was obtained by adding a nanocomposite as the saline–alkali soil remediating agent (SSRA) made up of attapulgite (ATP), phosphogypsum (PG), sodium polyacrylate (SP), and weathered coal (WC) to a traditional fertilizer (TF). SSRF could form micro/nanonetworks in SS and display a high retaining capacity on water and fertilizer nutrients because of the hydrogen bonds between SSRA and water molecules, urea, or NH4Cl. In addition, SSRF could effectively reduce the salinity and alkalinity in SS through ion exchange, deactivation, and pH adjusting. Thus, SSRF could significantly improve the microenvironment of SS, which could facilitate the growth of crops and increase the saline–alkaline tolerance of crops.Keywords: Attapulgite; Microenvironment; Remediate; Retaining; Saline−alkali soil

Nitrogen fertilizer tends to migrate into the environment through runoff, leaching and volatilization, causing severe environmental pollution. In this work, a high-performance water and nutrient loss control fertilizer (WNLCF) was developed by adding a high-energy electron beam (HEEB) dispersed attapulgite (HA)–sodium polyacrylate (P)–polyacrylamide (M) complex to traditional fertilizer. Therein, HA-P-M was used as the water and nutrient loss control agent (WNLCA), which could self-assemble to form three-dimensional (3D) micro/nano networks in aqueous phase. Thus, water and nutrient could be effectively combined and held in the networks which could be then retained in the soil via the filtering effect of soil, resulting in low loss of water and nutrient. Pot experiments of 15N labeled fertilizer indicated that WNLCF could effectively improve the amounts of fertilizer nutrients in the stem of corn and facilitate the growth of corn. Therefore, this work provides a promising approach to enhance the utilization efficiency of water and nutrient, and lower the pollution risk of fertilizer.Keywords: Attapulgite; Loss control; Micro/nano networks; Polyacrylamide; Sodium polyacrylate;

Phytosterol oxidation products (POPs) are constituents of the human diet. Definitive information on the toxic or biological effects of POPs is limited and in some cases contradictory. This study evaluates the cytotoxicity of four individual 7-ketophytosterol oxides, including 7-ketositosterol (7K-SI), 7-ketocampesterol (7K-CA), 7-ketobrassicasterol (7K-BR), 7-ketostigmasterol (7K-ST), and a mixture of 7-ketophytosterols (7K-MIX) toward a human intestinal carcinoma (HIC) cell line. Results showed that all tested compounds reduced cell proliferation in a dose-dependent manner; especially 7K-SI and 7K-CA exhibited higher activities. Both compounds increased early apoptotic cells and caused cell cycle arrest in the G1 phase with cell accumulation in the S phase. No evidence of cell death was observed induced by 7K-ST and 7K-MIX. Furthermore, 7K-SI, 7K-CA, and 7K-BR induced apoptosis by enhancing caspase-3 activity and the modulatory effects of Bcl-2, while 7K-ST and 7K-MIX did not involve caspase-3 activation and Bcl-2 down-regulation.

•1,10-Diaminodecane, graphene and β-CD were self-assembled on the surface of a glassy carbon electrode.•Detection of DEHP was performed by electrochemical impedance spectroscopy.•The sensor was highly sensitive and selective to DEHP molecules and showed fine stability.A glassy carbon electrode modified with β-cyclodextrin/graphene/1,10-diaminodecane (β-CD–G–DAD) composite was used to detect Di(2-ethyl hexyl) phthalate (DEHP) by electrochemical method. The composite electrode was fabricated by self-assembly method: DAD was grafted to the surface of a glassy carbon electrode (GCE), and graphene oxide (GO) sheets were absorbed on the amine-terminated DAD (GO/DAD), then β-CD could be bound with GO through hydrogen bond (β-CD/GO/DAD), finally β-CD/GO/DAD was electrochemically reduced to β-CD/G/DAD. The DEHP entered into cyclodextrin cavity to form the guest–host complex proven by UV–vis spectra, and the characteristic of β-CD/GO composite was shown by FT-IR spectra. The composite electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The charge resistance value increased linearly with concentration of DEHP in the range of 0.2–1.2 μM, and the detection limit was 0.01 μM (3σ method). The composite electrode showed good selectivity and stability.A β-cyclodextrin-graphene-1,10-diaminodecane composites self-assembled on glassy carbon electrode by interaction was used to collect Di(2-ethyl hexyl) phthalate (DEHP), and detect DEHP by electrochemical method.

A β-cyclodextrin–graphene (β-CD–G) hybrid composite modified glassy carbon electrode for the first time was used for electrochemically detecting di(2-ethylhexyl)phthalate (DEHP), based on the inclusion of DEHP into β-CD. The electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. At the composites electrode, the impedance value increased linearly with the increasing DEHP concentration in the range of 2 μM to 18 μM, the limit of detection was 0.12 μM (3σ method), with a correlation coefficient of 0.998. The electrode showed good selectivity, reproducibility and stability. Obviously, the collected amounts of DEHP by β-CD–G could be detected through this electrochemical method. Furthermore, this simple and low-cost sensing platform can in principle be extended to the detection of other phthalate esters which can form host–guest complexes with cyclodextrin.

Pesticide sprayed onto plant leaves tends to discharge into the environment through rainwater washing, leaching, and volatilization, resulting in severe pollution to soil, water, and air. Here, to control pesticide loss, we developed a loss-control pesticide (LCP) by adding straw ash-based biochar and biosilica (BCS) to traditional pesticide. BCS possesses a porous micro/nano structure and thus can adsorb a large amount of pesticide molecules to form pesticide–BCS complexes that tend to be retained by the rough surface of plant leaves, displaying a high adhesion performance on the leaves; therefore, the pesticide loss decreases, sufficient pesticide for the plant is supplied, and the pollution risk of the pesticide can be substantially lowered.Keywords: adhesion; biochar and biosilica; chlorpyrifos; loss-control pesticide;

Sterols (cholesterol and phytosterols) are important structural components of cell membranes and major constituents of lipid metabolism. Research on their oxides, such as the factors affecting oxidation, oxides’ structures, and qualitative and quantitative analysis, aroused more attention in this decade. However, the biological roles of individual phytosterol oxides are still unclear because no commercial individual phytosterol oxide standards are available. Different from the traditional chemical synthesis, in the present study, chemical synthesis from a starting phytosterol mixture followed with a semipreparative HPLC separation produced individual oxides. TLC and analytical HPLC were used here to not only monitor the reaction process but also specifically analyze the synthetic intermediates and oxides. The chromatographic results exhibited strict rules and similar characteristics. Finally, for the first time, four individual phytosterol oxides were successfully separated and collected by a semipreparative HPLC system, thus providing a novel strategy for the preparation of individual phytosterol oxides.

Pistacia chinensis Bunge (P. chinensis) is a deciduous and dioecious perennial arbor of the family Anacardiaceae that flowers from March to April and bears fruit from September to October. There are three rapidly growing stages in the annual growth process of P. chinensis. However, the knowledge of the secondary metabolites related to P. chinensis gender and growth season remains scant. In this study, HPLC was used to qualitatively and quantitatively determine the content of the catechin hydrate, rutin, quercetin, and kaempferol contents in male and female tree inflorescences and leaves. Total phenolics and flavonoids were also detected using a spectrophotometer. The results indicated that the contents of these compounds fluctuated with seasons and they reached the highest levels in nascent leaves. The fluctuations of these compounds followed different pathways of evolution, by increasing or decreasing in male and female trees throughout the whole growth process because they had their own biological functions. Moreover, the extracts exhibited DPPH radical scavenging bioactivity and showed no significant cytotoxicity towards 3T3-L1 preadipocytes. Together, these results demonstrated that P. chinensis has great potential as an antioxidant medicine, and the best harvest time is in the spring.

A β-cyclodextrin–graphene (β-CD–G) hybrid composite modified glassy carbon electrode for the first time was used for electrochemically detecting di(2-ethylhexyl)phthalate (DEHP), based on the inclusion of DEHP into β-CD. The electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. At the composites electrode, the impedance value increased linearly with the increasing DEHP concentration in the range of 2 μM to 18 μM, the limit of detection was 0.12 μM (3σ method), with a correlation coefficient of 0.998. The electrode showed good selectivity, reproducibility and stability. Obviously, the collected amounts of DEHP by β-CD–G could be detected through this electrochemical method. Furthermore, this simple and low-cost sensing platform can in principle be extended to the detection of other phthalate esters which can form host–guest complexes with cyclodextrin.