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Herein, the clinically approved nitrogen mustard, chlorambucil (Chl), is covalently embedded into a poly(N-(2-hydroxypropyl)methacrylamide, HPMA) vector via a hydrolysable ester bond to overcome the shortcomings of Chl as well as to achieve better efficacy. The well-defined poly-prodrug amphiphiles with Chl loading content >10 wt% can form uniform nanoparticles with an average diameter of 200 nm through a macromolecular self-assembly strategy. The detailed structure information and Chl release properties are carefully inspected. Cytotoxicity studies against the HepG2 and MCF-7 cell lines combined with flow cytometry reveal that the poly(HPMA)–Chl conjugate exhibits obvious targeting ability and markedly enhanced antitumor effect compared to the free Chl. After labelling with a fluorescent group, the cell uptake, lysosome escape and distribution in living organs of the poly-prodrug were also studied.

Penicillium expansum is an important postharvest pathogen of pomaceous fruit and a causal agent of blue mold or soft rot. In this study, we investigated the effect of ambient pH on growth, ultrastructure alteration, and pathogenicity of P. expansum, as well as accumulation of patulin and expression of genes involved in patulin biosynthesis. Under different pH, the fungus was routinely cultured and collected for growth, pathogenicity, patulin production, and gene expression studies using transmission electron microscopy, apple inoculation, HPLC, and RT-qPCR methods. Different ambient pH had significant impact on expression of genes and growth factors involved in patulin biosynthesis. Under same range of pH, gene expression profile, growth factors, and patulin accumulation (in vivo and in vitro) all showed similar changing trends. A well-developed cell was observed in addition to upregulation of genes at pH between pH 5.0 and 7.0, while the opposite was observed when pH was too basic (8.5) or too acid (2.5). Additionally, ambient pH had direct or indirect influence on expression of PecreaA, PelaeA, and PepacC. These findings will help in understanding the effect of ambient pH on growth, pathogenicity, and patulin production and support the development of successful methods for combating P. expansum infection on apple fruits.

The anticancer drug 6-MP was covalently bonded to the –OH group of poly(HPMA) via a glutathione-responsive carbonyl vinyl sulfide linker. In vitro simulation assay demonstrated that the poly(HPMA)–PTA conjugate exhibited a markedly enhanced antitumor effect on HepG2 cells.

In this study, we report the preparation and characterization of the PVA–DTPA–Gd conjugate as a potential MRI contrast agent (CA). The r1 value and the r2/r1 ratio were about 5.6 mM−1 s−1 and 1.31, respectively. In vitro toxicity studies not only demonstrated that the polymeric system possessed good biocompatibility, but also proved that the conjugate could be an attractive candidate for CA.

Four new hetero-pentanuclear 3d–4f complexes [Zn4(L)2La(NO3)2(OEt)(H2O)] (1), [Zn4(L)2Ce(NO3)2(OMe)(MeOH)] (2), [Zn4(L)2Pr(NO3)2(OEt)(EtOH)] (3) and [Zn4(L)2Nd(NO3)2(OMe)(MeOH)] (4) were synthesized by the reactions of a newly synthesized octadentate bis(salamo)-based tetraoxime ligand (H4L) with Zn(OAc)2·2H2O and Ln(NO3)3·6H2O (Ln = La, Ce, Pr and Nd), respectively, and characterized via elemental analyses, FT-IR, UV-Vis spectroscopy and single crystal X-ray crystallography. The X-ray crystallographic investigation revealed that all ZnII ions were located in N2O3 coordination spheres, and possessed a trigonal bipyramid coordination environment. The LnIII ion lay in an O8 coordination sphere, and adopted a distorted square antiprismatic coordination environment. Furthermore, supramolecular interactions and fluorescence properties were investigated.

Ochratoxin A (OTA) is a very important mycotoxin. However, there are few studies on the removal of OTA in wine because of the great influence on product quality and difficulty in practical application. A nano-MgO-modified diatomite ceramic membrane (MCM) with a high positive charge was prepared and applied to remove OTA in wine. The isotherm adsorption between the positively charged membrane and OTA was in accordance with the Langmuir model, with a maximum adsorption capacity of 806 ng/g at 25 °C. All of the changes in adsorption enthalpy (ΔH), adsorption free energy (ΔG) and adsorption entropy (ΔS) were negative, which indicated that the combination of nano-MgO MCM and OTA was a spontaneous exothermic and nonspecific physical adsorption process. The concentrations of OTA in adsorption-treated wines were lower than 2 μg/kg, and the removal rates exceeded 92%. After OTA removal, the composition of wines was preserved to some extent.

Fusarium sulphureum is a major causal agent of dry rot of potato and fusarium rot of muskmelon fruit. Ozone (O3), a kind of strong oxidant, is widely tested to control postharvest disease in fruit and vegetables by inhibiting the growth of pathogenic fungi. In this study, the effect of ozone treatment on dry rot development, growth of F. sulphureum, diacetoxyscirpenol (DAS) accumulation in vivo and in vitro, and ergosterol biosynthesis were evaluated. The results showed that 2 mg L−1 O3 treatment effectively suppressed dry rot development, DAS accumulation in vivo and in vitro, and significantly inhibited mycelial growth of F. sulphureum. The colony edges and scanning electron microscopy (SEM) observation showed that O3 treatment significantly changed morphological structure of the mycelia; it became shorter, shriveled and rough. Transmission electron microscopy (TEM) results revealed that degradation of organelles intensified, distribution of cytoplasm became uneven, and the integrity of cell membrane was destroyed. Moreover, O3 treatment decreased ergosterol content and DAS accumulation by down-regulating expression of genes involved in ergosterol and DAS biosynthesis pathway. In addition, there was positive correlation between ergosterol content and DAS accumulation in vitro. These results indicate that ozone suppresses dry rot development and DAS accumulation by affecting growth of F. sulphureum and down-regulates expression of genes involved in ergosterol and DAS biosynthesis.

A newly synthesized fluorescent chemosensor H

Both poly(HPMA)-DTPA/DOTA-Gd conjugates were constructed in a facile manner and presented no significant side effects, as confirmed by cytotoxicity and hemocompatibility studies. The T1 relaxivity values of poly(HPMA)-DTPA/DOTA-Gd conjugates were about 7.8 and 8.6 mM−1 s−1. The r2/r1 ratio values were about 2.78 and 2.92; thus, both polymer conjugates are desirable candidates as magnetic resonance imaging contrast agents.

A highly sensitive and selective fluorescence sensor for the detection of Zn2+ and Cu2+ was derived from a Salamo-type bisoxime ligand. The developed sensor is capable of detecting Zn2+ and Cu2+ in aqueous media through fluorescence turn on and off, respectively. In addition, the complexes of Zn2+ and Cu2+ could successfully sense the presence of H+/OH− via increase (ON)/decrease (OFF) in fluorescence intensity. Single crystal structures of Cu2+, Ni2+ and Cd2+ complexes have been characterized using X-ray crystallography, respectively. The Cu2+ complex forms a dinuclear structure with both Cu2+ being five-coordinated with square pyramidal geometries; the Ni2+ and Cd2+ complexes are both tetranuclear structures where the Ni2+ and Cd2+ are almost six-coordinated with slightly distorted octahedral geometries. More specifically, one of the Cd2+ forms a novel six-coordinated triangular prism geometry which is rarely reported.

Three new solvent-induced Ni(II) complexes with the chemical formulae [{Ni(L)(CH3OH)}2(µ-OAc)2Ni] (1), [{Ni(L)(C3H7OH)}2(µ-OAc)2Ni] (2) and [{NiL(H2O)}2(µ-OAc)2Ni] (3) were synthesized by the reaction of the Salamo-type ligand 4,4′-dinitro-2,2′-[1,2-ethylene-dioxybis(nitrilomethylidyne)]diphenol (H2L) with Ni(II) acetate tetrahydrate in different solvents and characterized by elemental analyses, FT-IR, UV–Vis spectra and X-ray crystallography. X-ray crystallographic analyses indicate that complexes 1, 2 and 3 have similar structures, consisting of three Ni(II) atoms, two completely deprotonated (L)2− units, two µ-acetate ions and two coordinated solvent (methanol, n-propanol and H2O) molecules, thereby forming slightly distorted octahedral geometries. Although the Ni(II) atoms are all hexa-coordinated in these complexes, there are obvious differences in their crystal and supramolecular structures due to solvent effects: Complex 1 forms an infinite 2D network structure, while complexes 2 and 3 form infinite 3D supramolecular structures by strong hydrogen bonding interactions.

Amino and thiolated aptamers are the main aptamers used to construct label-free electrochemical impedimetric aptasensors. In this study, the modification performance and electrochemical properties of amino aptamers and thiolated aptamers were studied in the construction of label-free impedimetric sensors. The results showed that the initial modification density of amino aptamers was higher than that of thiol aptamers. Aptamers can recognize and bind OTA to generate electrical signals. The higher the density of aptamer modification was, the better the electric signals were. If only considering the initial modification density, amino aptamers were more suitable for the preparation of aptasensors than thiolated aptamers. However, the modification density of the amino aptamer decreased with the prolonged immersion time in 1 mM HCl solution, which suggests that the stability of this sensor was poor. However, the thiolated aptamer maintained relatively constant density and could be reused. Thus, the thiolated aptasensor had a wide range and good reproducibility and stability for the determination of ochratoxin A (OTA). In addition, this study proved that gold nanoparticles play an important role in signal amplification by increasing the effective gold surface to fix more aptamers in the process of sensor preparation.

Four new hetero-pentanuclear 3d-4f complexes [Zn

A simple and sensitive label-free impedimetric aptasensor for rapid determination of ochratoxin A (OTA) has been developed, which was based on the combination between thiolated aptamer and gold nanoparticles by layer-by-layer self-assembly. Because of the interaction between aptamer and OTA, the relative normalized electron-transfer resistance (&Delta, Rct) values obtained by electrochemical impedance spectroscopy (EIS) was proportional to the concentration of OTA and showed a good linear relationship from 0.1 to 10.0 ng/mL, with a lower detection limit (0.030 ng/mL) than one-step thiolated DNA aptasensor. The established method was successfully applied to detect and analyze OTA in table wine and grape juice, and the recovery was 90.56%&ndash, 104.21% when PVP effective removed of phenolic substances. The label-free impedimetric aptasensor was used for rapid detection and quantitation of OTA in the inoculated grapes with the Aspergillus Nigri (H1), and the production of OTA (62.4 &mu, g/kg, 20 &mu, g/kg) far exceeded the maximum levels of 2 &mu, g/kg after inoculation for three days. The developed method exhibited a good specificity, high sensitivity, time-efficient, and it could be applied to detect the OTA concentration in grape and its commodities.

A newly synthesized fluorescent chemosensor H6L was explored for detecting B4O72−, characterized by 1H NMR spectrum, mass spectrum and fluorescence spectra. During the detection process of B4O72−, the fluorescence is significantly enhanced and naked eye recognition can be performed under 365 nm UV light without any interference by other typical anions. The limit of detection is as low as 6.97 × 10-10 M. In addition, in order to broaden the application of salamo-based fluorescence sensors in the field of biology, except for the fluorescence imaging of HeLa cells, the first attempt of exogenous detection in zebrafish was conducted successfully.

Two newly designed tetranuclear transition metal(II) complexes, [{Co(L)(μ-OAc)Co(CH3OH)2}2] and [{Ni(L)(DMF)(μ-OAc)Ni}2] derived from an unsymmetrical salamo-like donor-N2O4 ligand (H3L: 6-hydroxy-6′-methoxy-2, 2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) were synthesized and characterized by elemental analysis, FT-IR, UV-vis, fluorescence spectroscopy, X-ray crystallography and Hirshfeld surface analysis. The Co(II) complex includes two fully deprotonated (L)3− moieties, two μ-acetato ligands and four coordinated methanol molecules, bearing a highly symmetrical tetranuclear structure. The terminal Co(II) ions are penta-coordinated and have slightly twisted triangular bipyramidal geometries, and the central Co(II) ions are hexa-coordinated and possess slightly twisted octahedral geometries. The Co(II) complex was self-assembled by adequate intermolecular hydrogen bonding interactions giving rise to an infinite two-dimensional supramolecular structure. The Ni(II) complex adopts a symmetric tetranuclear structure including two fully deprotonated (L)3− units, two coordinated DMF molecules, and two μ-acetato ligands. All the Ni(II) ions are hexa-coordinated and have slightly twisted octahedral geometries. At the same time, the fluorescent properties and Hirshfeld surfaces analyses of the Co(II) and Ni(II) complexes were also investigated in detail.

A highly selective fluorescent sensor H4L based on a bis(salamo)-type compound with two N2O2 chelating moieties as ionophore was successfully developed. Sensor H4L was found to have excellent selectivity for B4O72− over many other anions (Br−, CI−, CN−, CO32−, HCO3−, H2PO4−, HSO4−, NO3−, OAc−, S2O3−, SCN−, SO42−, Hcy (homocysteine) and H2O2), and it exhibited an approximately 150-fold enhancement of the fluorescence response to B4O72− in Tris-HCl buffer (DMF/H2O = 9:1, v/v, pH = 7) solutions. Significantly, its fluorescence intensity was enhanced in a linear fashion with increasing concentrations of B4O72−. The detection limit of sensor H4L towards B4O72− was 8.61 × 10−7 M. The test strips could conveniently, efficiently and simply detect B4O72− ions in Tris-HCl buffer (DMF/H2O = 9:1, v/v, pH = 7) solutions. Furthermore, sensor H4L showed excellent membrane permeability in living cells, and it was successfully used to monitor intracellular B4O72− by confocal luminescence imaging.

A novel starch-based material, designated as DASU-EDTA, was firstly prepared by the reaction of EDTA anhydride with previously synthesized dialdehyde urea starch (DASU). This material was characterized by IR spectroscopy and used as an adsorbent to remove Cu (II) ions from aqueous solution. The IR results showed EDTA was successfully attached to the glucose units of starch, and DASU-EDTA was one of starch amides derivatives. The adsorption tests revealed that the adsorption of DASU-EDTA for Cu (II) ions was an endothermic process, which mainly relied on the strong chelation of EDTA to metal ions. The optimal conditions should be controlled at pH 5.0 and 120min. In addition, it was found that the high initial concentration of Cu (II) ions was favorable for the adsorption of DASU-EDTA for Cu (II) ions.

An environmental friendly slow-release urea fertilizer with double films (SUFDF) was prepared by using dialdehyde starch urea resin (DASU) as inner coating and polylactic acid (PLA) as outer materials. The structural, chemical characteristics and morphology of the SUFDF were characterized by FTIR, element analysis and SEM. Its efficiency in slowing the nitrogen release was examined via soil leaching and pot experiments. The experimental results indicated that the introduction of hydrophobic PLA and DASU reduced the swell ability of the fertilizer, which made it can provide nitrogen persistently at the early farming. After the urea dissolved, the DASU in the fertilizer would continue to release nitrogen due to its good slow-release property. So this fertilizer would have potential applications in modern agriculture and horticulture.

A lot of studies were done on the base material of drug carriers: liposome, protein microsphere, glutin and high polymer microsphere were all of shortages, but starch has much superiority as the drug carrier. The paper embarked from the analysis the chemical and physical properties of potato starch. According as the characteristic of long chain molecules of potato starch forming microcrystal bundle via inter-molecules hydrogen association under room temperature, which disintegrated in water solution as temperature rising, the better levels of factors, such as gelatinization temperature, gelatinization time, volume of water, pH, according to viscosity of starch gelatinization were select firstly. A W/O reverse emulsion was obtained by dispersing the starch gelatinization into the oil. The effect of emulsifier, evocating agent, crosslinker, crosslinking temperature, and crosslinking time was investigated. An orthogonal experiment of L27(313) was designed to identify the main factors affecting them. In light of range analysis, the comparative importance of factors impacting drug loading was obtained, separately. The effects of parameters were studied using analysis of variance. The results showed that the effective factor to control drug loading were the amount of starch, the volume of water, pH, crosslinking time and the amount of evocating agent, whereas the influences of other factors on drug loading were not significant. In addition, the structure of N, N-Methylenebisacrylamide (MBAA) crosslinked potato starch microsphere (CPSM) was characterized by Fourier transform infrared (FTIR) spectrophotometer and Scanning electron microscope (SEM).