Search

Selenium (Se) is an essential micronutrient for human beings and plants are the current main sources of Se element in Asian diet. Therefore a feasible way to increase people's Se intake is to increase Se content in plants. In this paper, we focus on how the tomato (Solanum Lycopersicum) yield and quality are influenced by the effect of irrigation amount, Se-enriched and high-calcium organic fertilizer and compound fertilizer amount respectively. The results from a two-year experiment show that the combination of Se-enriched organic fertilizer and compound fertilizer can significantly increase the tomato yield comparing with the use of NPK organic or compound fertilizer. It is also shown that by applying more Se-enriched and high-calcium organic fertilizer the contents of Se, Lycopene, Vitamin C (Vc) and soluble sugar in tomato fruit can be increased considerably. It was found that the highest Se content was achieved using 100% Se-enriched organic fertilizer combined with irrigation at 100% in 2016 and 100% Se-enriched organic fertilizer with irrigation at 80% in 2017. Deficit irrigation (80%) can help to increase Water Use Efficiency (WUE) and the Se and VC contents in tomato yield. Therefore in order to improve the Se-enriched tomato yield and quality, it is suggested to apply 100% Se-enriched organic fertilizer and adopt the deficit irrigation at 80%.

Over the past years, perylenediimide (PDI)-based polymers have emerged as one of the widely studied polymer acceptors applicable to all-polymer solar cells (PSCs) due to their outstanding photovolt...

Significant breakthroughs have been achieved in bulk-heterojunction (BHJ)-based organic solar cells (OSCs) with power conversion efficiencies (PCE) of over 17% upon the development of new cores of non-fullerene acceptors and the isomers that are often produced in the synthesis of the cores. Here, two benzo[1,2-b:4,5-b′]dithiophene (BDT)-based acceptors, which are isomers with different orientations of the thiophene rings on the backbone, are reported. The different molecular configurations and electron cloud distributions of the isomers were studied using theoretical calculations, which indicate that the isomers have completely different optical properties and various electrochemical energy levels. Grazing-incidence wide-angle X-ray scattering (GIWAXS) tests showed that the two isomers have different crystalline structures. OSC devices developed from each of the two isomers exhibit significant differences in electron/hole mobilities and packing modes, leading to clearly distinct fill factors (FFs) and short-circuit currents, affecting the PCEs of the final devices. These studies of core isomerism provide some new insights into the configurations of backbones and could assist in the molecular design of new n-type electron acceptors.

Multifunctional transformation of amide C-N bond cleavage is reported. The protocol applies to benzamide, thioamide, alcohols, and mercaptan under similar reaction conditions catalyzed by NaOTs. It is noteworthy that NaOTs can not only be recycled and reused for up to three cycles without significant loss in catalytic activity, but also catalyze gram-grade reactions. This study provides a novel solution with mild conditions and a simple procedure for transformation of multiple amides.

A ductile polycaprolactone (PCL)/modified polyurethane (PU) composite with double mosaic structure was prepared through a novel technology. The composite would be used to reduce waste of resources and the environmental hazards of hogwash oil and expand the application of hogwash oil. Composites with different microstructures were obtained by regulating the proportions of “hard segment-phase” PU and “soft segment-phase” PCL. Meanwhile, the influences of microstructure on the macroscopic physicochemical properties of composites were investigated. Results demonstrated that when the PCL content was 30%, a wrapping structure was similar to “Punica granatum L.” and embedded network structure between organic silica-modified PU and PCL were observed in the composite. Owing to the double mosaic structure, the water permeability of the composite was reduced by 61.9% lower than that of modified PU. However, the hydrophobicity of the former was 15.6% higher than that of the latter. The component fixation rate reached 80.8%, resistance to humidity and heat was strengthened. Coated fertilizers were prepared using the composite as the coating material were slightly superior to organic-silica-modified PU in terms of slow N releasing performance. The prepared composite exhibited good physicochemical properties and showed promising application values in many fields, such as coating materials, thermoplastic elastomer and fertilizers. This study provides a novel strategy for preparing porous materials.

The palladium-catalyzed decarbonylative Suzuki-Miyaura coupling of amides via selective amide C-N bond cleavage was reported, which afforded mild access to substitute biaryl products in the presence of low catalyst loading with NaHCO3 as the base in good yields within 4 h (29 examples).

The development of isomeric molecules has been widely exploited in molecular structures associated with organic solar cells (OSC) and is an effective pathway to finely tune the photoelectric properties and device performance. The molecular properties of nonfullerene acceptors and the morphology of blend films can be effectively controlled by manipulating isomeric substituent positions on benzene-fused end-capping groups (EG) in acceptors. Here, three isomeric EGs were designed and synthesized which simultaneously possess an electron-withdrawing bromine and an electron-donating methyl substituent. By linking three isomeric EGs, (Br,Me), (Br,Me)-1, and (Br,Me)-2 each with the BTP-CHO core, three isomeric small-molecule acceptors (SMA) were obtained. The power conversion efficiency (PCE) of PM6:BTP-(Br,Me)-1-based OSCs is 13.43%, is much higher than that of PM6:BTP-(Br,Me)- (11.92%) and PM6:BTP-(Br,Me)-2- (11.08%) based devices. Our results show that isomeric EGs can provide strategies to tune the absorption spectra of SMAs, intramolecular charge transfer (ICT) and electron mobility of organic semiconductor device, and ultimately increase the performance of nonfullerene acceptors.

To elevate the performance of polymer solar cells (PSC) processed by non-halogenated solvents, a dissymmetric fused-ring acceptor BTIC-2Cl-γCF3 with chlorine and trifluoromethyl end groups has been designed and synthesized. X-ray crystallographic data suggests that BTIC-2Cl-γCF3 has a 3D network packing structure as a result of H- and J-aggregations between adjacent molecules, which will strengthen its charge transport as an acceptor material. When PBDB-TF was used as a donor, the toluene-processed binary device realized a high power conversion efficiency (PCE) of 16.31 %, which improved to 17.12 % when PC71ThBM was added as the third component. Its efficiency of over 17 % is currently the highest among polymer solar cells processed by non-halogenated solvents. Compared to its symmetric counterparts BTIC-4Cl and BTIC-CF3 -γ, the dissymmetric BTIC-2Cl-γCF3 integrates their merits, and has optimized the molecular aggregations with excellent storage and photo-stability, and also extending the maximum absorption peak in film to 852 nm. The devices exhibit good transparency indicating a potential utilization in semi-transparent building integrated photovoltaics (ST-BIPV).

In this work, three new nonfullerene acceptors (BT6IC-BO-4Cl, BT6IC-HD-4Cl, and BT6IC-OD-4Cl), which comprise a central fused benzothiadiazole core and two dichlorinated end groups and substituted with different branched alkyl chains [2-butyloctyl (BO), longer 2-hexyldecyl (HD), and 2-octyldodecyl (OD)], are successfully designed and prepared. The influences of the branched alkyl chain with different lengths on the electronic/optoelectronic property, electrochemistry, and photovoltaic performance are systematically investigated. It has been revealed that BT6IC-HD-4Cl, which had the medium alkyl chain (2-hexyldecyl) length, has the best photovoltaic performance when using PDBT-TF as the electron donor. The BT6IC-HD-4Cl-based device shows an impressive power conversion efficiency of 14.90%, much higher than BT6IC-BO-4Cl (14.45%)- and BT6IC-OD-4Cl (9.60%)-based devices. All these evidence shows that the subtle changes in the alkyl substituent of these high-performance chlorinated acceptors can have a big impact on the structural order and molecular packing of the resultant nonfullerene acceptors and ultimately on the photovoltaic performance of the final solar devices.

The concept of bromination for organic solar cells has received little attention. However, the electron withdrawing ability and noncovalent interactions of bromine are similar to those of fluorine and chlorine atoms. A tetra‐brominated non‐fullerene acceptor, designated as BTIC‐4Br, has been recently developed by introducing bromine atoms onto the end‐capping group of 2‐(3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐ylidene) malononitrile and displayed a high power conversion efficiency (PCE) of 12%. To further improve its photovoltaic performance, the acceptor is optimized either by introducing a longer alkyl chain to the core or by modulating the numbers of bromine substituents. After changing each end‐group to a single bromine, the BTIC‐2Br‐m‐based devices exhibit an outstanding PCE of 16.11% with an elevated open‐circuit voltage of V oc = 0.88 V, one of the highest PCEs reported among brominated non‐fullerene acceptors. This significant improvement can be attributed to the higher light harvesting efficiency, optimized morphology, and higher exciton quenching efficiencies of the di‐brominated acceptor. These results demonstrate that the substitution of bromine onto the terminal group of non‐fullerene acceptors results in high‐efficiency organic semiconductors, and promotes the use of the halogen‐substituted strategy for polymer solar cell applications., The bromination of non‐fullerene acceptors provides a promising alternative approach for the creation of high‐performance organic solar cells. BTIC‐2Br‐m‐based devices exhibit an outstanding power conversion efficiency of 16.11% with an elevated open circuit voltage of 0.88 V, representing one of the highest efficiencies in brominated non‐fullerene acceptors.

Background and objectivePalmitic acid (PA), the most common saturated free fatty acid (FFA) in food, is related to obesity-related male infertility. The possible mechanism is PA-mediated inhibition of testosterone secretion. Endoplasmic reticulum (ER) oxidoreductin-1alpha (ERO1α), an oxidase that is localized in the ER, plays an essential role in maintaining ER homeostasis and is related to hormone secretion. However, the role and underlying mechanisms of ERO1α in PA-mediated inhibition of testosterone secretion have not been reported. Material and methodsMurine Leydig tumor cell line 1 (MLTC-1) cells were treated with different doses of PA. Cell viability, testosterone secretion, and ERO1α expression were measured by the Cell Counting Kit 8 (CCK-8) assay, enzyme-linked immunesorbent assay (ELISA), and Western blotting, respectively. Moreover, the expres-sion of ER stress marker proteins (glucose-regulated protein 78 [GRP78] and CCAAT/enhancer-binding protein homologous protein [CHOP]) was also measured after treatment. Subsequently, the expression ofERO1α was knocked down, and cell viability, testosterone secretion, and ER stress were measured after treatment with the PA or the ER stress agonist thapsigargin (TG, an ER stress inducer). Also, testosterone secretion was measured by ELISA when ER stress was inhibited by 4-phenylbutyric acid (4-PBA, an ER stress inhibitor). ResultsPA treatment reduced cell viability, induced ERO1α expression, and enhanced the expression of the ER stress marker GRP78 and CHOP, while ERO1α knockdown inhibits ER stress marker expression, promotes testosterone secretion, and enhances cell viability in PA-treated MLTC-1 cells. In addition, ERO1α knock-down rescued the TG-induced the decrease in testosterone secretion and cell viability. ConclusionsThese findings suggest that PA inhibits testosterone secretion via ER stress and that ERO1α knockdown ameliorates PA-induced decreases in testosterone via ER stress in testicular Leydig cells. Our results indi-cate the necessity of exploring the potential applications of ERO1α as a target gene for restoring fertility in obese men.

Campylobacter jejuni (C. jejuni) contamination on poultry surface posed great threats to meat industry and human health. In order to control the propagation of C. jejuni, the gelatin nanofibers containing thyme essential oil/β-cyclodextrin e-polylysine nanoparticles (TCPNs) were engineered. Firstly, TCPNs were successfully fabricated via ionic gelation. The prepared TCPNs showed excellent antimicrobial activity against C. jejuni, which caused membranolysis and protein leakage of C. jejuni. Subsequently, TCPNs were incorporated into gelatin nanofibrous matrix via electrospinning to produce antimicrobial nanofibers. Uniformly disordered fibrous structure with good continuity and fine diameter distribution was observed. Finally, the aerobic bacterial count, thiobarbituric acid, total volatile basic nitrogen, pH, color and texture of meat samples packaged with the nanofibers were detected. The results implied the TCPNs embedded gelatin nanofibers had a promising prospect in meat preservation without impact on sensory evaluation.

Owing to the limitation of DNA-specific recognition, improving the sensitivity of bacteria detection without additional culture poses a considerable challenge. Herein, a sensitive, novel, and high-specificity fluorescence detection method was developed using transcription activator-like effectors (TALEs) as the specifically recognized element. Based on the property of TALEs for recognizing double-stranded DNA, the detection method was first proposed. Its sensitivity was further improved by isothermal amplification of RPA. The "humanoid" molecular beacon (H-MB) was designed to achieve signal output. The steric hindrance of the protein opens the stem, enhancing the fluorescence intensity of an attached FAM/BHQ-1 pair. This method can be used to detect Escherichia coli O157:H7 with single-base mismatch specificity and high sensitivity (detection limit of 3 cfu mL-1) and can be applied in actual sample detection by boiling the sample for 10 min. TALEs can be assembled according to the target, so the method can be used to detect other foodborne pathogens and viruses in the food safety and clinical fields.

It is of great significance to develop efficient donor polymers during the rapid development of acceptor materials for nonfullerene bulk-heterojunction (BHJ) polymer solar cells. Herein, a new donor polymer, named PBTT-F, based on a strongly electron-deficient core (5,7-dibromo-2,3-bis(2-ethylhexyl)benzo[1,2-b:4,5-c']dithiophene-4,8-dione, TTDO), is developed through the design of cyclohexane-1,4-dione embedded into a thieno[3,4-b]thiophene (TT) unit. When blended with the acceptor Y6, the PBTT-F-based photovoltaic device exhibits an outstanding power conversion efficiency (PCE) of 16.1% with a very high fill factor (FF) of 77.1%. This polymer also shows high efficiency for a thick-film device, with a PCE of ≈14.2% being realized for an active layer thickness of 190 nm. In addition, the PBTT-F-based polymer solar cells also show good stability after storage for ≈700 h in a glove box, with a high PCE of ≈14.8%, which obviously shows that this kind of polymer is very promising for future commercial applications. This work provides a unique strategy for the molecular synthesis of donor polymers, and these results demonstrate that PBTT-F is a very promising donor polymer for use in polymer solar cells, providing an alternative choice for a variety of fullerene-free acceptor materials for the research community.

The position of a chlorine atom in a charge carrier of polymer solar cells (PSCs) is important to boost their photovoltaic performance. Herein, two chlorinated D‐A conjugated polymers PBBD‐Cl‐α and PBBD‐Cl‐β are synthesized based on two new building blocks (TTO‐Cl‐α and TTO‐Cl‐β) respectively by introducing the chlorine atom into α or β position of the upper thiophene of the highly electron‐deficient benzo[1,2‐b:4,5‐c′]dithiophene‐4,8‐dione moiety. Single‐crystal analysis demonstrates that the chlorine‐free TTO shows a π‐π stacking distance (d π‐π) of 3.55 Å. When H atom at the α position of thiophene of TTO is replaced by Cl, both π‐π stacking distance (d π‐π = 3.48 Å) and Cl···S distance (d Cl‐S = 4.4 Å) are simultaneously reduced for TTO‐Cl‐α compared with TTO. TTO‐Cl‐β then showed the Cl···S non‐covalent interaction can further shorten the intermolecular π‐π stacking separation to 3.23 Å, much smaller than that of TTO‐Cl‐α and TTO. After blending with BTP‐eC9, PBBD‐Cl‐β:BTP‐eC9‐based PSCs achieved an outstanding power conversion efficiency (PCE) of 16.20%, much higher than PBBD:BTP‐eC9 (10.06%) and PBBD‐Cl‐α:BTP‐eC9 (13.35%) based devices. These results provide an effective strategy for design and synthesis of highly efficient donor polymers by precise positioning of the chlorine substitution., Chlorination of the β‐position of benzo[1,2‐b:4,5‐c′]dithiophene‐4,8‐dione can enhance the intermolecular interaction. Single‐crystal analysis demonstrates that TTO‐Cl‐β exhibits the smallest π‐π stacking distance of 3.23 Å, much smaller than that of TTO‐Cl‐α and TTO. Accordingly, PBBD‐Cl‐β based on TTO‐Cl‐β achieved an outstanding power conversion efficiency (PCE) of 16.20%, providing a new insight for the design of acceptor units.

Introduction: Vancomycin damage to the kidney is one of the severe adverse reactions. The primary objective of this study was to discuss how the clinical pharmacists should deal with the results of therapeutic drug monitoring (TDM) for Vancomycin. Case Presentation: A case of severe acute kidney injury in a 60-year-old woman receiving Vancomycin as empirical therapy is reported here. The patient was admitted to the respiratory intensive care unit (RICU) of the First Affiliated Hospital of Bengbu Medical College, China, on 15 Oct 2015. On Day 7, the steady-state serum trough concentration and peak concentration of Vancomycin were 102.2 and 111.9 μg/mL, respectively. Clinical pharmacists immediately contacted the clinicians and advised them to discontinue Vancomycin therapy as soon as possible, and the proposal was adopted. On Day 8, serum creatinine (SCr) increased to 719 μmol/L, and creatinine clearance rate (CrCl) decreased to 6 mL/min; then, the patient was given dialysis treatment. After she underwent dialysis treatment, SCr decreased to 330 μmol/L and CrCl increased to 14 mL/min on Day 19; then, the patient was discharged after she accepted the doctor’s advice to start a home-dialysis program outside the hospital. Conclusions: In this case, clinical pharmacists contacted the doctor to avoid further aggravated renal damage timely when they found a significant increase in Vancomycin concentrations. It indicates that the Vancomycin level can be used as an indirect marker of renal function as increased Vancomycin level results from and contributes to acute kidney injury.

A water-soluble antibacterial polysaccharide from dandelions (PD) was chemically modified to obtain its carboxymethylated derivative (CPD). The degree of substitution of CPD was 0.455. Fourier transform infrared (FTIR) spectra analysis, zeta potential, particle size and rheological test verified the carboxymethylation of PD, accompanying with the change of physicochemical properties. Moreover, Listeria monocytogenes treated with 10 mg/mL PD and CPD achieved 1.96 and 3.29 log CFU/mL reduction in population, respectively. Subsequently, PD and CPD were incorporated into polyethylene oxide (PEO) nanofiber matrix to fabricate antimicrobial nanofibers. The prepared nanofibers were characterized by scanning electron microscope, atomic force microscope and FTIR. Finally, both PD/PEO and CPD/PEO nanofibers exhibited favourable antibacterial effect on L. monocytogenes, with an improved antibacterial activity of CPD/PEO nanofibers than PD/PEO nanofibers. In conclusion, this study demonstrated PD and CPD could be applied to the fabrication of antibacterial food packaging.

Carbon fiber-reinforced zirconium carbide matrix (Cf/ZrC) composites were fabricated by a liquid metal infiltration process at 1200 °C, using low melting Zr7Cu10, ZrCu and Zr2Cu alloys as infiltrators. The effects of Cu on microstructure and mechanical properties of the composites were investigated. The results indicated that the products were composed of either single- or polycrystalline ZrC, C and Cu. With increasing Cu content in the infiltrators, the yield of ZrC decreased from 43.7 vol% to 27.9 vol%. When ZrCu was used as an infiltrator, the obtained composites exhibited a better bending strength of 98.2±3.1 MPa. What is more, the use of Zr2Cu could provide the highest fracture toughness of the composites with a moderate debonding.

As a non-thermal sterilization method, pulsed light (PL) has been widely applied in food industries to control the microbial contamination, however little is known about the antimicrobial mechanism of PL. This study deeply investigated the antimicrobial mechanism of PL against Escherichia coli O157:H7 (E. coli O157:H7). The changes of morphology, endoenzyme, entocyte, respiratory metabolism and DNA of E. coli O157:H7 after PL treatment were emphatically studied. TEM and SEM results exhibited that cell integrity was destroyed heavily after PL treatment. Entocyte including proteins, ATP and DNA were reduced remarkably for PL-treated samples. In addition, the activity of ATPase, β-galactosidase, alkaline phosphatase, topoisomerase, as well as the metabolism were inhibited for E. coli O157:H7 with PL treatment. The electron spin resonance spectrum validated the production of hydroxyl radical by PL, thus resulting in the elevation of intracellular reactive oxygen and the acceleration of cell death. Finally, PL displayed better antibacterial activity in carrot juice without adverse effect on its quality.

Aggregation-induced emission (AIE) dyes now serve as powerful tools for fluorescence analysis and biological imaging due to their light-up property in the aggregated state. Herein, we proposed an AIE dye-based aptasensor, enabling label-free and turn-on detection of mycotoxin. The positively charged AIE dyes would confer high-affinity to negatively charged aptamers and be lighted up by the aggregation process of dye molecules. Attributed to the resistance of ochratoxin A (OTA)-binding aptamer complex to enzyme digestion, label-free analysis of OTA could be realized via the synergetic utilization of AIE dyes and enzymatic digestion process. The digestion process could contribute to a signal to background ratio (S/B) of 1.71 for OTA detection. Remarkably, the adoption of AIE dyes would lead to a dramatic enhancement of over 104.5% of S/B compared to conventional nucleic acid dyes, thus favoring the sensitivity of the aptasensor. Only one aptamer sequence was involved in the assay, thus avoiding the complex structure design of aptamer probes. The AIE dye-based aptasensor could confer a limit of detection of 0.4 ng/mL for OTA detection. Besides, it exerted remarkable specificity for identifying OTA, and has been successfully applied for OTA analysis in wine and coffee. AIE dyes would be a compelling candidate in biohazard screening filed, and the proposed aptasensor would potentially provide a universal platform for on-site detection of food and environment contaminations.

This research focused on the fabrication and characterizations of polyethylene oxide (PEO)/Dendrobium officinale polysaccharide (DOP) antibacterial nanofibers by electrospinning technique. As the DOP contents increased in spinning solutions, viscosity decreased along with the increase in conductivity. The morphology of nanofibers changed from uniform structure to beaded structure with the formation of droplet, thus the thermal, mechanical, chemical and antibacterial properties of nanofiber got worse. After addition of adipic acid in PEO/DOP spinning solutions, viscosity increased obviously, which resulted in the uniform fiber structure even at high DOP content. Consequently, the properties of nanofibers were modified correspondingly, implying better miscibility between PEO and DOP by the aid of adipic acid. Finally, adipic acid added PEO/DOP nanofibers at high DOP content exhibited better antibacterial activity against E. coli on pork samples, without impact on the quality of pork. Hence, this study suggested the feasibility of PEO/DOP nanofiber as packaging material for pork preservation.

Carbon fiber-reinforced zirconium carbide matrix composites (Cf/ZrC) were prepared by vacuum infiltrating porous carbon/carbon preforms with molten Zr2Cu alloy at 1200 °C. X-ray diffraction, scanning electron microcopy and transmission electron microscopy analysis were used to characterize the composition and microstructure of the final composites. It was found that the matrix of the composites were composed of the Cu–Zr–C amorphous phase dispersed with either single- or polycrystalline ZrC. Based on the microstructural analysis, the formation mechanism of the matrix was proposed to be a solution-precipitation and grain coalescence process. The influence of the heat treatment at 1800 °C was also investigated. Results indicated that at very high temperature the volatilization of residual metal somewhat deteriorated the flexural strength and the elastic modulus, but the fracture toughness of the composites was improved due to the sintering of ZrC grains.

Background It was previously reported that propofol, an intravenously administered hypnotic and anesthetic agent, protects organs from ischemia–reperfusion (I/R) injury. However, the underlying mechanisms are largely unknown. Glycogen synthase kinase 3β (GSK-3β) is known to play an important role in the oxidative stress–induced apoptosis. In this study, we investigated the role of GSK-3β and mitochondrial permeability transition pore (MPTP) in the protective effects of propofol against hepatic I/R injury. Materials and methods The left and median hepatic artery and the portal vein branches were blocked by no-damage artery clips to create the model of partial ischemia (70%), and liver lobes were subjected to warm ischemia for 30, 60, 90 min, respectively. Reperfusion of 120 min was then initiated by the removal of clamp. The MPTP opening was assessed by measuring mitochondrial large amplitude swelling and mitochondrial membrane potential. Results Pretreatment with propofol in conditions of hepatic I/R inhibits the apoptosis of hepatocytes as evidenced by decreased terminal deoxynucleotidyl transferase dUTP nick end labeling–positive cells. Importantly, propofol suppressed the mitochondrial GSK-3β by promoting or preserving its phosphorylation at Ser9, thus restraining the opening of MPTP and preventing the mitochondrial swell and mitochondrial membrane potential collapse. Conclusions Propofol protects liver from I/R injury by sustaining the mitochondrial function, which is possibly involved with the modulation of MPTP and GSK-3β.

Carbon fiber-reinforced zirconium carbide matrix (C f /ZrC) composites were fabricated at 1200 °C, by vacuum infiltrating C f /C performs with molten Zr 7 Cu 10 , ZrCu and Zr 2 Cu intermetallic compound respectively. The influences of Cu contents in the infiltrators on composition, microstructure and ablation resistance of the final composites were investigated. Results showed that: the products were composed of either single- or polycrystalline ZrC, C and Cu. With the increasing Cu content in the infiltrators, both the growth and crystallization of ZrC grains were inhibited, and the yield of ZrC decreased from 43.7 vol% to 27.9 vol%. Tested by an oxyacetylene torch, the composites show excellent anti-ablation properties affected apparently by the Cu contents.

An attractive way to prepare carbon fiber-reinforced ZrC matrix composites was proposed and confirmed experimentally. The experimental results showed that the resulting composites were fabricated by immersing carbon/carbon preforms in molten Zr 2 Cu at 1200 °C for 3 h. ZrC was the main phase, with a content of 42.2 ± 1.3 vol.%. The composites exhibited excellent ablation resistance when undergoing ablation with an oxyacetylene torch, the mass loss rate and linear recession rate being 0.0006 ± 0.0001 g s −1 and 0.0003 ± 0.0001 mm s −1 , respectively.

Zirconium diboride–zirconium carbide based composites were fabricated by reactive melt infiltration with boron carbide and Zr 2 Cu at 1200 °C. Mechanical properties of the composites before and after high temperature treatments were investigated. The presence of elongated ZrB 2 grains and amorphous residual alloy provided the composites with an excellent fracture toughness of 12.1 MPa m 1/2 . High temperature treatments could improve the density of sintered composite and increase the bonding strength between ZrB 2 and ZrC grains. This resulted in a flexural strength of 469.7 MPa and an excellent fracture toughness of 13.6 MPa m 1/2 was obtained after a treatment at 1600 °C in argon. The evaporation of copper at 1600 °C in vacuum during heat treatment caused degradation in the mechanical properties. However, at a higher temperature of 1800 °C, the composite showed the highest flexural strength of 484.1 MPa and the highest flexural modulus of 282.2 GPa, apparently counterbalanced the Cu-loss effect.

Tungsten–zirconium carbide composites were fabricated at different temperatures by the displacive compensation of porosity (DCP) method, the microstructure, mechanical properties, and ablation resistance were investigated. It was found that no WC phase was left in the composites prepared at 1400 °C, and a few residual W 2 C particles were surrounded in W product. Microstructure analyses revealed that zirconium atoms diffused into tungsten carbide to form ZrC and W 2 Zr besides carbon diffused into the Zr 2 Cu melt. Composites fabricated at 1400 °C had a flexural strength of 356.7 ± 15.2 MPa, an elastic modulus of 193.7 ± 9.8 GPa, a fracture toughness of 7.0 ± 0.7 MPa m 1/2 , and a hardness of 13.6 ± 0.7 GPa. After ablated by an oxyacetylene flame for 30 s, the higher temperature prepared composites had a better ablation resistance, the linear ablation rate was 0.0033 ± 0.0004 mm/s, and the mass ablation rate was 0.0012 ± 0.0001 g/s.

It has been suggested that breast cancer stem cells (CSCs), which characterized by CD44(+)CD24(-/low), may result in treatment failure in patients with breast cancer. It is possible therefore that that inhibiting such subpopulation might subsequently improve clinical outcome. In the present study, we found that the CD44(+)/CD24(-/low) CSCs, isolated from both human breast cell line MCF-7 and MDA-MB-231, were more resistant to thiotepa, paclitaxel and anthracycline, when compared with the non-breast cancer stem cell subset from the same cell lines, whereas the chemosensitivities were remarkably reversed by higher concentration of thiotepa and paclitaxel except for adriamycin. The percentage of CSCs was significantly decreased with an addition of DNA methyltransferase inhibitor CDA-2 and the expression of Smo, Shh, and Gli-1 of Hedgehog signaling pathway in CSCs was decreased. Of important findings, combination of thiotepa or paclitaxel with CDA-2 could significantly inhibit the proliferation of CSCs regardless of their dosages. These results unveiled that the selection of cytotoxic agents and increasing their dosage might be of great importance in the respect of eliminating CSCs. DNA methyltransferase inhibitor CDA-2 exhibited a synergistic effect with cytotoxic drugs, which might provide a conceptually new therapeutic strategy.

Organically derivatised polyoxometalate (POM) clusters containing bromo or iodo groups can undergo ligand-free, Pd-catalysed Heck carbon-carbon coupling reactions with alkenes, with bromomagnesium phenylamide as a base (see scheme). This protocol offers a new route to organic-inorganic hybrid molecular materials in which POM clusters are covalently bonded with organic conjugated segments.

The classical Biginelli reaction is considerably extended by use of cycloalkanones instead of 1,3-dicarbonyl compounds. Use of TMSCl as a Lewis acid allowed one-pot chemoselective multicomponent Biginelli reactions between cycloalkanones, urea or thiourea, and aldehydes. Under similar reaction conditions, thiourea exhibited different behavior to urea, and aliphatic aldehydes showed lower reactivity than aromatic aldehydes. A possible mechanism to account for the reaction is proposed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Trimethylsilyl chloride (TMSCl) was used as a Lewis acid to efficiently perform one‐pot, three‐components, Biginelli condensation reactions of aldehydes, 1,3‐dicarbonyl compounds, and urea or thiourea. This resulted in simple one‐pot synthesis of the corresponding 3,4‐dihydropyrimidin‐ 2(1H)‐ones at room temperature with excellent yield.

ZrB 2 based composites were prepared by a novel reactive melt infiltration process. The porous boron bars were used as preforms and infiltrated by the low melting Zr 2 Cu intermetallic compound. Thermodynamics calculations revealed that B could react with liquid Zr 2 Cu to form ZrB 2 as low as 1100 °C. Composites were prepared by heating the two materials to 1200 °C for 3 h in vacuum. The resultant composites were studied with XRD and SEM. ZrB 2 was identified to be the main constituent. The composites had a flexural strength of 414.3 MPa, a flexural modulus of 183.6 GPa, and a fracture toughness of 5.5 MPa m 1/2 .

A novel three-component, one-pot condensation yielding 2-amino-4H-1,3-oxazines or 2-amino-4H-1,3-thiazines from alkynes, urea or thiourea, and aldehydes is described. [reaction: see text]

The title compound, C14H18N2O2S, which was obtained from an extended Biginelli reaction, contains a pyran ring with a chair conformation, a pyrimidine ring with a half-chair conformation and a benzene ring. The crystal structure is stabilized by an intermolecular hydrogen-bond network.

The title compound, C14H18N2O2, which was obtained from an extended Biginelli reaction, contains a pyran ring with a chair conformation, a pyrimidine ring with a half-chair conformation and a benzene ring. The crystal structure is stabilized by an intermolecular hydrogen-bond network involving both NH groups and the carbonyl group.

The title compound, C19H20O5, was synthesized by the reaction of 1,3-cyclohexanedione and 4-hydroxybenzaldehyde in the presence of PdCl2 and thiourea. The tetrahydropyran ring and the six-membered cyclohexene ring adopt envelope conformations, and the six-membered cyclohexane ring is in a chair conformation. The crystal packing is stabilized by classical intermolecular O—H...O hydrogen bonds and weak C—H...O interactions.

The title compound, C18H19NO, was synthesized from the multi-component one-pot reaction between p-toluidine, benzaldehyde and 2,3-dihydrofuran in the presence of palladium dichloride. There are two molecules in the asymmetric unit. The crystal packing is stabilized by classical intermolecular N—H...O hydrogen bonds.

The title compound, C14H13BrN2OS, was synthesized from the multicomponent reaction between thiourea, 4-bromobenzaldehyde and cyclohexane-1,3-dione. The crystal packing is stabilized by intermolecular N—H...O, N—H...S, C—H...O and C—H...S hydrogen bonds. Br...O interactions [3.183 (3) Å] are also observed in the crystal structure.

The title compound, C30H26Br2O4·C2H5OH, was synthesized from the reaction between 5-bromosalicybenzaldehyde and 5,5-dimethyl-1,3-cyclohexanedione. The crystal packing is stabilized by intermolecular O—H...O hydrogen bonds and C—H...O interactions.

Monofunctionalized alkylimido derivatives of hexamolybdate, (Bu(4)N)(2)[Mo(6)O(18)( identical withN-R)] (R = methyl, Me; ethyl, Et; n-propyl, n-Pr; i-propyl, i-Pr; n-butyl, n-Bu; t-butyl, t-Bu; cyclohexyl, Cy; n-hexyl, Hex; and n-octadecyl, Ode), have been prepared in high purity and good yield by the reaction of [Bu(4)N](4)[alpha-Mo(8)O(26)] with appropriate aliphatic amine hydrochlorides in anhydrous acetonitrile, using N,N'-dicyclohexylcarbodiimide (DCC) as the dehydrating agent. Eight compounds have been determined by single crystal X-ray diffraction analysis and all compounds have been studied with (1)H-NMR, IR, UV-vis, ESI mass spectrometry and cyclic voltammetry. A structural and (1)H-NMR study show beta hydrogen atoms of those alkylimido derivatives of hexamolybdate have strong Brønsted acidity compared to the hydrogen atoms in other positions.

In this article, we report the synthesis of bifunctional Au-Fe(3)O(4) nanoparticles that are formed by chemical bond linkage. Due to the introduction of Au nanoparticles, the resulting bifunctional Au-Fe(3)O(4) nanoparticles can be easily modified with other functional molecules to realize various nanobiotechnological separations and detections. Here, as an example, we demonstrate that as-prepared Au-Fe(3)O(4) nanoparticles can be modified with nitrilotriacetic acid molecules through Au-S interaction and used to separate proteins simply with the assistance of a magnet. Bradford protein assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were performed to examine the validity of the separation procedure, and the phosphate determination method suggested that the as-separated protein maintained catalytic activity. This result shows the efficiency of such a material in protein separation and suggests that its use can be extended to magnetic separation of other biosubstances. Moreover, this synthetic strategy paves the way for facile preparation of diverse bifunctional and even multifunctional nanomaterials.

The title compound, C(19)H(26)O(3), was synthesized directly from the condensation of 5,5-dimethyl-cyclo-hexane-1,3-dione with malononitrile catalysed by palladium chloride: there are two molecules in the asymmetric unit.

[(n-C4H9)4N]2[Mo6O18(N-1-C10H(6)-2-CH3)] (1) has been prepared by the reaction of 1-amino-2-methylnaphthalene hydrochloride with [(n-C4H9)4N]4[alpha-Mo8O26] in the presence of 1,3-dicyclohexylcarbodiimide. Three solvent-free crystalline phases are isolated from the mixed solvents of acetone and acetic ether. The X-ray single-crystal structures of the three phases have been determined, showing the packing and supramolecular assembly characters (pseudohigher symmetry, helical chains, and pi-pi stacking) by which the effect of solvent polarity and crystallization speed on polymorphism in organic-inorganic hybrids has been demonstrated.

Trimethylsilyl chloride (TMSCl) was used as a Lewis acid to efficiently perform one‐pot, three‐components, Biginelli condensation reactions of aldehydes, 1,3‐dicarbonyl compounds, and urea or thiourea. This resulted in simple one‐pot synthesis of the corresponding 3,4‐dihydropyrimidin‐ 2(1H)‐ones at room temperature with excellent yield.

Arbutin was synthesized from glucose by two-step reaction below: (a) 2,3,4,6-tetra-O-acetyl-alpha-D-glucosyl chloride or bromide was prepared by glucose and acetyl halide (chloride or bromide). (b) 2,3,4,6-tetra-O-acetyl-alpha-D-glucosyl halide (Cl, Br) reacted with hydroquinone, methanol as solvent at pH=9.5-10.0.

In this communication, we demonstrate that polyoxomolybdates can activate sp3 C−H bonds in aliphatic amines. Unexpectedly, a carbon−carbon double bond is formed from two aliphatic primary amines via the activation and dehydrogenative coupling of two sp3 C−H bonds near the nitrogen atom bearing a hexamolybdate. Detailed experiments including 1H NMR, 13C NMR, IR, UV−vis, ESI-MS, and especially X-ray single-crystal diffraction substantially confirm the existence of carbon−carbon double bonds in a class of so-resulting organic−inorganic hybrid molecules, which are made up of two terminally substituted imidohexamolybdate cages bridged by a trans-tetrasubstituted, conjugated, rigid ethylene system. This discovery perhaps opens an interesting road to elaborate the CC double bond directly via the functionalization of saturated C−H bonds.

The title compound, (C16H36N)2[Pd2Br6], was prepared from palladium(II) bromide and tetrabutylammonium bromide. In the anion, the terminal and bridging Pd—Br bond lengths lie in the ranges 2.3982 (9)–2.4185 (8) and 2.4389 (7)–2.4513 (7) A, respectively. The anion can be viewed as a dimeric cluster consiting of two edge-sharing PdBr4 square units, which make a dihedral angle of 7.84 (4)°.