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Light-driven utilization of CO2 in organic synthesis is highly attractive because it mimics nature. However, such transformations are mainly limited to the incorporation of only a single CO2 molecule into organic compounds, far less than the number of CO2 molecules fixed in the product in photosynthesis. Here we report the visible-light photoredox-catalysed dicarboxylation of alkenes, allenes and (hetero)arenes with the incorporation of two CO2 molecules. This method realizes the formation of multiple C–C bonds with high chemo- and diastereoselectivities under mild conditions, which represents a simple, rapid and sustainable approach to valuable dicarboxylic acids. Moreover, this transition-metal-free protocol exhibits a low catalyst loading, good functional group tolerance, broad substrate scope, facile scalability and easy product derivatizations to give drug and material molecules. Mechanistic studies indicate a pathway by which a visible-light-induced two-electron reduction via sequential single electron transfer generates radical anions of such unsaturated substrates, broadening the repertoire of strategies. Transformations in organic chemistry are mainly limited to the incorporation of only one equivalent of the greenhouse gas CO2 per substrate. Now, a visible-light photoredox-catalysed dicarboxylation of alkenes, allenes and arenes allows the incorporation of two CO2 molecules into organic compounds.

Traditional fermented soybean contains a variety of microflora. To obtain a comprehensive and accurate understanding of the microbial community structure and metabolic potential of fermented soybean, comparative metagenomics and metatranscriptomics were performed on a sample of fermented soybean in Yunnan Province. Metagenomic DNA and metatranscriptomic RNA were sequenced using Illumina HiseqTM2500, which yielded a total of 92,192,276 reads, with an average read length of 150 bp and 38,798,262 paired-end sequences, with an average length of 151 bp. The results show that Providencia stuartii was the most abundant species and the genes of carbohydrates (2296, 13.30%), protein metabolism (1530, 8.86%), and amino acids and amino acid derivatives (1423, 8.24%) were dominant. The expression levels of the genes belonging to amino acid transport and metabolism processes were the highest according to the reads per length of transcript in kilo-bases per million mapped reads (RPKM) values, followed by energy production and conversion and carbohydrate transport and metabolism. The metabolic pathways were primarily associated with carbohydrates, proteins and amino acids, which might be in accordance with the high levels of proteins and other nutrients in soybeans. Overall, these findings provide insights into the community structure and metabolic potential of the fermented soybean microbiome.

Background: Currently, the identification of Clara cell and type II alveolar epithelial cell-type cancer cells requires electron microscopy, which is a time-consuming and expensive process involving a complicated tissue sampling procedure. The aim of this study was to identify unique biomarkers for Clara cell and type II alveolar epithelial cell-type lung cancer cells, respectively, with proteomic profiling. Methods: Six human lung adenocarcinoma cell lines (A549, NCI-H358, NCI-H1650, HCC827, NCI-H1395, and NCI-H1975) were investigated for their ultrastructural characteristics. The differentially expressed proteins (DEPs) were screened between NCI-H358 cells (Clara cell type) and A549 cells (type II alveolar epithelial cell type) using two-dimensional difference gel electrophoresis (2D-DIGE) and matrix- assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS/MS), and then they were validated by western blot. The protein expression levels of endoplasmic reticulum oxidoreductin 1-α (ERO1L), Clara cell 10-kD protein (CC10), and surfactant protein C (SP-C) were also determined in the six cell lines assayed. Results: NCI-H358 cells featured Clara cell differentiation; A549, NCI-H1975, and HCC827 cells had characteristics of type II alveolar epithelial cells; and NCI-H1395 and NCI-H1650 cells had no differentiation characteristics of any lung adenocarcinoma cell type. Five DEPs including ubiquitin carboxyl- terminal hydrolase isozyme L1 (UCHL1), cytokeratin 19 (CK19), cytokeratin 8 (CK8), ERO1L, and peroxiredoxin 2 (PRDX2) between NCI-H358 and A549 cells were identified for further validation; however, none of them showed suitability as an effective biomarker. Similarly, CC10 and SP-C were not appropriate biomarkers. Conclusions: Cytological subtypes of NCI-H1975 and HCC827 cells were identified, but no promising biomarker was discovered in the present study.

Upon heating, polyesters decompose to small molecules and release flammable volatiles and toxic gases, primarily through chain scission of their ester linkages, and therefore exhibit poor fire-safety properties, thus restricting their applications. Reported herein is an end-group-capturing effect of (bis)oxazoline groups, generated from the thermal rearrangement of the N-(2-hydroxyphenyl)phthalimide (HPI) moiety which was incorporated into the polyester chain by copolymerization. These copolyesters, as a result, exhibit high efficiency in retarding decomposition by capturing the decomposed products, particularly for the carbonyl-terminated fragments, thus increasing the fire-safety properties, such as self-extinguishing, anti-dripping, and inhibiting heat release and smoke production. The successful application of this method in both semi-aromatic and aliphatic polyesters provide promising perspectives to designing versatile fire-safe polymers.

Enhanced apoptosis of cardiomyocytes in suffering overloaded saturated fatty acids (SFAs) can result in myocardial infarction and cardiac dysfunction. The function of vascular endothelial growth factor (VEGF) in cardiomyocyte protection was not clearly described. To investigate the preservative effects of VEGF sensitization on ceramide-mediated programmed cell death of cardiomyocytes, palmitate-induced injury in H9c2 cells was established as an in vitro model. Results revealed that 0.5 mM palmitate application effectively led to debased viability and activated apoptotic factors. A significant time-dependent relation between PAL and cardiomyocyte injury was observed. The apoptosis rate was increased greatly after 16 h of treatment with 0.5 mM PAL. In addition, cell viability was restored by VEGF overexpression during treatment with 0.5 mM PAL. Reduced apoptosis rate and expression of caspase 3, Bax, and NF-κB p65 were observed in this process, while boosted Bcl-2, p-JNK/JNK expression and activity of caspase 3 were checked. However, p-ERK/ERK levels did not exhibit a significant change. These findings indicated the protective effects of VEGF in confronting the ceramide-induced cardiomyocyte apoptosis, and would devote therapeutic targets for cardiovascular safeguard in dealing with fatty acid stress.

Cancer can invade or spread to almost all parts of the body. The increasing morbidity and high mortality of cancer create a great demand for the development of novel anticancer drugs. Coumarin derivatives are ubiquitous in nature and can readily interact with diverse enzymes and receptors in cancer cells via weak bond interactions; hence, coumarin is a highly privileged pharmacophore for the development of novel anticancer agents. This review will focus on the recent development of coumarin hybrids as potential anticancer agents covering articles published from 2019 to 2020.

A target-guidance separation strategy composed of activity screening process with high-performance liquid chromatography and separating process with high-speed countercurrent chromatography (HSCCC)...

High-performance and multifunctional epoxy resins (EPs) are of great use in the booming electric & electronic and 5G fields, however their fabrication shows huge challenges. Herein, through a facile strategy by simply incorporating a functional molecule DPI (phosphaphenanthrene polyethylenimine), which possessed a unique structure with hyperbranched polyethyleneimine as flexible inner core and phosphaphenanthrene groups as rigid outer shell, a high-performance and multifunctional epoxy resin was successfully fabricated. The hyperbranched rigid-flexible structure of DPI endowed the resultant thermoset EP-DPI with superb mechanical performance and high glass transition temperature, for which, at a low DPI content (≤4 wt%), EP-DPI exhibited 160%, 40%, and 31% improvement in impact toughness, tensile strength, and flexural strength compared with neat EP. At the same time, the good compatibility between DPI and the EP matrix enabled EP-DPI to be highly transparent, and the aromatic phosphorus structure endowed EP-DPI with excellent UV-shielding effect in the UV-A band. The dielectric performance of EP-DPI was enhanced due to the unique structure of DPI and its interaction with the EP matrix. Furthermore, the phosphaphenanthrene groups endowed EP-DPI with excellent anti-ignition, self-extinguishing, and low heat release during combustion. This work opens up a new strategy for developing novel high-performance and multifunctional EPs with potential versatile applications.

The use of conventional flame-retardant elements such as Cl, Br, P for carbon-based polymers usually leads to the deterioration of smoke and toxic gas release, and possesses serious environmental and ecological issues. Herein, we proposed a facile strategy to largely improve the flame-retardant efficiency of an eco-friendly flame-retardant method. By simply tailoring the substitution position of the functional polymerization monomer, the corresponding copolymer exhibited extremely high flame retardancy, including a 59% lower peak heat release rate (pHRR), a 48% lower smoke density, a high limiting oxygen index (LOI) of 30%, and passed the UL-94 V-0 rating without dripping. More importantly, the para-substitution copolymer showed a much higher flame-retardant efficiency than the meta-substitution copolymer, for which the monomer content needed for UL-94 V-0 rating, high LOI value, and low smoke and toxic gas release largely decreased by 25%. The detailed mechanism and the different performance between the two copolymers were comprehensively investigated. The results first confirmed the “end-group-capturing” mechanism, then revealed that the different flame-retardant efficiency was owing to the different thermal rearrangement capability of the two functional monomers. The molecular-level mechanism revealed here provided a novel thinking for designing flame-retardant polymers.

A novel cell line, Epinephelus moara kidney cell line (EMK), was established from kidneys of kelp grouper E. moara. Cells were cultured at 24 °C in Leibovitz's L-15 medium (L15) supplemented with antibiotics, basic fibroblast growth factor (bFGF), foetal bovine serum (FBS) and 2-mercaptoethanol (2-ME). EMK cells, fibroblastic in morphology, proliferated to 100% confluency in 3-4 days and were subcultured for over 50 passages. The cells could grow from 18 to 30 °C, with optimal growth at 24 °C. Chromosome analysis indicated that the modal chromosome number was 48 in the cells at passage 42. Green fluorescent signals could be observed in EMK cells when the cells were transfected with pEGFP-N3 plasmid. Moreover, a significant cytopathic effect (CPE) was observed in the cells after infection with Singapore grouper iridovirus (SGIV) or nervous necrosis virus (NNV), and viral replication was confirmed by quantitative real-time PCR (qPCR). These results suggested the potential of the EMK cell line for studies of transgene and pathogenesis of SGIV and NNV.

New bifunctional primary amine-squaramides catalyzed asymmetric Michael addition reaction of α,α-disubstituted aldehydes to maleimides has been developed. This organocatalytic asymmetric reaction provides easy access to functionalized succinimides with a broad substrate scope. Both enantiomers of desired succinimide derivatives were obtained in good to excellent yields (up to 98%) with excellent enantioselectivities (up to >99% ee).

Despite the excellent overall performance, the application of polyesters is severely restricted by their inherently high flammability. Although many gratifying results have been achieved through different fire-safety methods, customization is still needed for every specific polymer, thus a generally applicable method is highly desired. Herein, we developed an eco-friendly and general fire-safety method for semi-aromatic polyesters based on the “end-group-capturing” concept. The functional monomer was chemically incorporated into the main chains of a series of semi-aromatic polyesters with similar structures (i.e., polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT)), and the specific contribution of the fire-safety method was investigated comprehensively. The results showed that the fire safety of all the copolyesters were efficiently improved, while interestingly, the fire safety gradually declined with the increase of the methylene group numbers in their molecular chains. The reason behind this phenomenon was comprehensively studied by both theoretical calculation and experiments. The increasing cyclization tendency of the copolyesters derived from the increase of the methylene group numbers was proved to be responsible for the decrease of the fire safety. The successful application and in-depth mechanism revealed here provide theoretical supports for the development of novel fire-safety polymeric materials.

An azobenzene-containing thermotropic liquid crystalline polyester showing unique thermo- and photo-responsive behaviours was synthesized by polycondensation from mesogenic dial 4,4′-bis(6-hydroxyhexyloxy)azobenzene (BHHAB) with 2-phenylsuccinic acid (PSA), and named as poly(4,4′-bis(6-hydroxyhexyloxy)azobenzene phenylsuccinate) (PBHPS). Liquid crystalline behaviours were investigated through differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and wide-angle X-ray diffraction (WAXD). PBHPS showed a smectic phase with strong π–π interactions between the adjacent phenyl rings or between the side group and mesogenic unit, which could be regarded as physical crosslinking points that made PBHPS have good shape memory and self-healing properties. A series of PBHPS/methylcellulose bilayer films were prepared to study the reversible photo-mechanical properties. UV-vis absorption spectra were used to study the reversible photo-responsive behaviour of the polyester, proving that the reversible photoisomerization-induced volume expansion of the PBHPS layer resulted in good reversible photo-responsive properties.

Novel liquid crystalline copolyesters named as P(BH-co-BPn)PS, with azobenzene and biphenyl group mesogenic units, were designed and synthesized conveniently by one pot melt polycondensation. All P(BH-co-BPn)PS copolyesters showed good thermal stability, smectic liquid crystalline behavior with π–π interactions in the polymer chains. As the three different functional building blocks (azobenzene and biphenyl chromophores, liquid crystals, π–π interactions) work together, P(BH-co-BPn)PS were responsive to external stimuli at the molecular level, exhibiting thermal shape memory, photo-induced bending and self-healing behaviors at the macroscopic level. It was noteworthy that the different responsive properties of the photo-active azobenzene and photo-inert biphenyl mesogenic units made a great contribution in the photo responsive behavior of these copolyesters, resulting in reversible bending and unbending behaviors for P(BH-co-BP30)PS. In addition, without the chemical crosslink, these copolyesters could be reshaped and reprocessed. Taking advantage of the features, these copolyesters containing amphi-mesogenic units can help to facilitate numerous applications like soft actuators and smart materials.

Different 0D, 1D and 2D carbon nanoparticles were added into a main chain liquid crystalline polyester (LCP) to investigate the effect of the nanoparticles on the shape memory behavior of LCP. Fullerene (C60), multi-wall carbon nanotube (CNT) and graphene (G) were selected as the fillers in an attempt to form π-π interaction with LCP chains, which acted as a physical crosslinking to obtain the increased shape recovery stress and recovery ratio. The composites were prepared by solution mixing. The formation of π-π interaction was investigated by wide angle X-ray diffraction (WXRD), fluorescence emission spectrometry and Raman laser spectrometry. Shape recovery stress and shape recovery ratio were recorded by dynamic mechanical analysis (DMA). Results indicated that C60 and CNT significantly augmented shape recovery ratio but had little effect on Shape recovery stress, while G diminished shape recovery ratio but improved the shape recovery stress.

Herein, binding of the β-cyclodextrin (β-CD) host to the unstable aryl pentazole guest has been confirmed experimentally and theoretically. After the confinement of aryl pentazole, electron density reorganization was studied by M06-2X dispersion-corrected DFT and further reflected in the characteristic shift in the NMR spectra. Among the host–guest complexes, the inclusion complex is favored with the phenyl ring expectedly encapsulated within the cavity through noncovalent interactions such as hydrogen bonding, C–H⋯π, and the special Csp2–H⋯H–Csp3 bonding discovered by the NBO, QTAIM, and NCI-RDG theories. The host–guest binding renders the enhancement of the nitrogen-ring aromatic character; this has been analyzed by employing nucleus-independent chemical shift (NICS)-based profiles. The non-covalent interaction largely enhances the thermal stability of the guest through a change of the decomposition reaction path whether the guest is encapsulated or not by the host. By comparison of the structures of B1–B4, the enhancement could be assigned to the ion-type transition structure stabilized by the C–H bonds of the host.

Chiral primary amine–squaramides have not been extensively studied to date in the field of organocatalysis. In this paper, novel chiral squaramides derived from natural product stevioside were developed. Both enantiomers of a series of γ-nitroaldehydes were generated by using these squaramide catalysts for the Michael addition reaction of isobutyraldehyde to nitroolefins. This asymmetric reaction proceeded well to afford the desired products in high yields (up to 98%) with high to excellent enantioselectivities (up to 99% ee).

Sugar content and composition are critical to fruit development. Sucrose, a photosynthate unloaded to the fruit, is metabolized by sucrose synthase, which might play a dominant role in sucrose accumulation during strawberry fruit ripening. However, substantial evidence regarding the molecular mechanism underlying sucrose accumulation in strawberry fruit development is lacking. Here, a strawberry sucrose synthase gene, FaSS1, was cloned and identified. Its 2421-bp cDNA includes an intact open reading frame and encodes an 806 amino acid protein, in which sucrose synthase-related conserved domains were predicted by a homology analysis. Using tobacco rattle virus-induced gene silencing, the downregulation of FaSS1 transcripts significantly delayed fruit ripening, as evidenced by the changes of firmness, and soluble sugar and anthocyanin contents, as well as the transcripts of several ripening-related genes, including PE1, PL1, XYL2, CHS, CHI, and DFR. Furthermore, the mRNA expression level of FaSS1 was inhibited by abscisic acid or sucrose, but not by glucose after fruit disc incubation in vitro. In conclusion, FaSS1 plays an important role in the regulation of strawberry fruit ripening, and its expression could be inhibited by abscisic acid and sucrose.

The S-adenosyl methionine synthetase gene FaSAMS1 is involved in the regulation of strawberry fruit ripening, however, the biochemical properties of FaSAMS1 protein remain unclear. Here, a coding cDNA sequence of FaSAMS1 was cloned by RT-PCR and inserted into a recombinant yeast expression vector pPICZA, then transformed into the yeast expression strain X-33. The fusion protein FaSAMS1 was induced, expressed, and purified. The enzymatic activity analysis of FaSAMS1 showed that the reaction system contains 0.09 mg of FaSAMS1, protein concentration reached at 0.454 mg·mL-1, the activity of the enzyme was 0.32 U, specific activity was 3.56 U·mg-1. This study has provided biochemical evidence for the involvement of ethylene in the regulation of strawberry fruit ripening.Â

Three monomers of G. elegans indole alkaloids (gelsemine, koumine and humantenmine) were simultaneously detected in porcine plasma for the first time with the development and validation of a sensitive and reliable LC-ESI-MS/MS method. Using a gradient mobile phase at a constant flow rate of 0.2 mL/min via electrospray ionization (positive ion mode) in a multiple reaction monitoring (MRM) scan, gelsemine, koumine and humantenmine were eluted, separated and detected at an appropriate retention time. The porcine plasma was prepared using protein precipitation with 1% formic acid-acetonitrile: methanol (2:1, v/v). Using matrix-matched calibration curves and weighted least squares linear regression, a good linearity (r2 > 0.99) was achieved with a concentration range of 0.1–200 μg/L for gelsemine, koumine and humantenmine; estimated LOD and LOQ values were 0.10 μg/L and 0.2 μg/L, respectively. The mean of the recoveries was in the range of 82.68–100.35% of porcine plasma at four different levels, and the intra-day and inter-day precision (CV) were lower than 15% with a range of 2.46–8.76% and 2.73–10.83%, respectively. The proposed method has proved to be suitable for accurate, quantitative determination of gelsemine, koumine and humantenmine in porcine plasma.

An esterification reaction of monomer acid with methanol using p-toluenesulfonic acid as catalyst for the preparation of biodiesel was studied. The process variables that influence the esterification of monomer acid, such as catalyst concentration, molar ratio of methanol to acid, reaction time and reaction temperature, were investigated and optimized. Through the single factor experiment, the optimum conditions obtained for the esterification were molar ratio of methanol to acid 3:1, usage amount of p-toluenesulfonic acid 6% and reaction time 3h, reaction temperature 70°C.The produced biodiesel was found to exhibit fuel properties within the limits prescribed by the latest American Standards for Testing Material (ASTM) and 0#diesel oil.

The chemical components of fatty acid in monomer acid were determined by GC/MS. After the sample was etherified via methanol, the chemical ingredients and their relative contents of fatty acid in it were analyzed by GC/MS. Fifteen components (such as Myristic acid, Palmitic acid, Oleic acid and Stearic acid ) were identified. The analyzed results showed that the Tetradecanoic acid content reached up to 12.16%, the Hexadecanoic acid accounted for 8.51%, the Octadecenoic acid arrived at 25.53% and the Octadecanoic acid 32.72%. The production technology of biodiesel from monomer acid, using p-toluenesulfonic acid as catalyst, was introduced. Through orthogonal analysis of parameters in a four-factor and three-level test, the optimum conditions obtained for the esterification were molar ratio of methanol to acid 3:1, usage amount of p-toluenesulfonic acid 6% and reaction time 3h, reaction temperature 60°C.Under the optimum conditions, conversion efficiency of biodiesel with monomer acid arrived at 98%.

By way of chemical marinate method, carrying out rare earth lanthanum to corrosion protect galvanized steel. The process of rare earth lanthanum conversion coating for galvanized steel was studied by using orthogonal experiment to get the optimized passivation parameters when the concentration of La (NO3) is 30g/L, H2O2is 20ml/L, pH=4 and was passivated at 40°C for 30s. The corrosion resistance was examined by weight loss tests, neutral salt spray tests (NSS) and electrochemical impedance spectroscopy (EIS). The results showed that the corrosion impedance of the pretreated sample was significantly improved, the corrosion rate was decreased by one order of magnitude, and the anti-white rust time was 54h.

This study describes an analytical method employing capillary gas chromatography (GC) using flame ionization detection (FID) that has been developed for the simultaneous determination of acrylates (methyl acrylate (MA), methyl methacrylate (MMA), butyl acrylate (BA)) in wastewater. For this purpose, dispersive liquid-liquid microextraction (DLLME) was applied as a sample preparation technique. The DLLME conditions such as the types and volume of extraction solvent, the types and volume of the disperser solvent, pH value and salt addition were studied and optimized. The method was linear in the ranges from 4.3×10-4 to 200.0 μg·mL-1 for abovementioned acrylates with R2≥ 0.9992. The DLLME procedure allowed efficient recovery of the investigated acrylates ranging between 81 % and 109 % with a relative standard deviation (RSD) ≤ 9.1 for the blank samples spiked with 10, 50 and 100 μg·mL-1 of acrylates, respectively. These results showed the potential of this technique for acrylates monitoring in wastewater samples. Furthermore, the investigated methods are simple, reproducible, and inexpensive.

To investigate liquid crystalline properties and structure relationships of chiral compounds based on menthol, a series of new chiral monomers derived from menthol derivatives, a mesogenic crosslinking agent, the corresponding side chain homopolymers with siloxane backbone, and cholesteric elastomers were synthesized. The structures and purity of these chiral compounds obtained in this study were characterized using FTIR, 1H NMR, and elemental analyses. The mesomorphism and thermal stabilities were investigated using differential scanning calorimetry, polarizing optical microscopy, thermogravimetric analysis, and X-ray diffraction. The selective reflection of light for the chiral monomers was studied with UV/visible/near IR. The effect of the crosslinking agent content on the phase transition temperatures of the elastomers was discussed. It was found that these chiral monomers seemed beneficial for the formation of the mesophases when a flexible spacer was inserted between the mesogenic core and the terminal menthyl groups. All obtained chiral monomers showed a cholesteric phase, chiral smectic C phase, and cubic blue phase. The crosslinking agent exhibited a smectic A (SA) phase and nematic phase. However, their corresponding homopolymers with siloxane chains tended to form a lower order SA phase. With an increase of the mesogenic rigidity, the melting temperatures, glass transition temperatures (Tg), and isotropic temperatures (Ti) of chiral monomers or homopolymers all increased. For the elastomers, general tendency was toward increased Tg and Ti with increasing the crosslinking agent content.

Monomer acid was the byproduct of preparing dimer acid from oleic acid in industry. Study its components and properties will contribute to the exploitation and application of it. First, we researched the physicochemical properties of monomer acid, such as iodine value, acid value, saponification value, and so on. The conclusion showed that the sample was a mixed fatty acid which contained longer chain of carbon and had high quality. Then, the chemical constituents of fatty acid in monomer acid were determined by GC/MS. After the sample was etherified via methanol, the chemical components and their relative contents of fatty acid from monomer acid were analyzed by GC/MS. Fifteen fatty acids predominated: myristic acid (12.16%), palmitic acid (8.51%), stearic acid (32.72%), and oleic acid (25.53%).

As an important component of large-scale extruder system for polymer material, Die-plate can be regarded as the final determinant for pelletization uniformity. Polymer melt was shaped in shaping channels and extruded from die-holes from Die-plate and then be diced. The design of shaping channels directly influences the uniformity for polymer-melt extrusion pressure and extrusion velocity of different die holes. In this paper, a three-dimensional flow model for polymer flow in Die-plate channel was presented, and then finite element simulation was used to analyze the distribution of extrusion velocity in each die-hole. Based on simulation result, a BP neural network model was applied to analyze the relationship between geometry factors of Die-plate, such as length of shaping channels, die hole extrusion velocity distribution, and extrusion uniformity. This optimization method can be used in the design of Die-plate to improve effect and quality of actual polymer production and processing.

A theoretical study of the complexes formed between HArF and XH 2 P (X = F, Cl, and Br) has been carried out using ab initio methods (MP2/aug-cc-pVDZ, MP2/aug-cc-pVTZ, and CCSD(T)/aug-cc-pVTZ). Three minima were found, which correspond to a hydrogen-bonded complex (I), a pnicogen-bonded complex (II), and a halogen-bonded complex (III). The pnicogen-bonded complex is the most stable, followed by the hydrogen-bonded complex, and the halogen-bonded complex is the least stable. The Ar–H bond is enhanced in FH 2 P–HArF–I complex and exhibits a blue shift, while it is weakened in ClH 2 P–HArF–I and BrH 2 P–HArF–I complexes and shows a red shift. A blue shift is also found for the distant Ar–H bond in the halogen-bonded and pnicogen-bonded complexes. These complexes have been understood with the electrostatic potentials and symmetry adapted perturbation theory (SAPT) method.

the adsorption of PCP using aerobic granules was studied. The static adsorption experiments were carried out and the Freundlich and Langmuir adsorption isotherms were applied to describe the biosorption processes and the isotherm constants were evaluated. The Freundlich and Langmuir isothermy adsorption equations obtained from the static experients were q=2.04ce0.82 and q=3.47ce /(1+0.56 ce), respectively. Both the adsorption isotherms described the static adsorption behavior of PCP well. Then the Freundlich adsorption isotherm was used to estimate the adsorption of PCP by aerobic granules in the dynamic state. The results showed that the adsorption mainly occurred in the initial periods during the operation of the reactor.

CH3Li–FArH–X (X = H2, OC, N2, P2, CO2, CO, BeH2) trimers have been investigated using quantum chemical calculations at the QCISD/6-311++G(2d,2p) level. The results show that the lithium bonding has a prominent effect on the strength and properties of the hydrogen bonding. The hydrogen-bonding interaction energy is increased by 160–340% due to the presence of lithium bonding. The Ar–H stretch vibration shows a blue shift in the FArH–X (X = H2, OC, N2, CO2, CO) dimer, but a red shift in the FArH–X (X = P2, BeH2) dimer. The red shift is increased in the corresponding trimer, while the blue shift shows a different change. The blue shift is also increased in CH3Li–FArH–X (X = H2, OC, N2, CO2) trimers, but it changes to a red shift in the CH3Li–FArH–CO trimer. The shift change is consistent with the explanation given by Joseph and Jemmis.

Quantum chemical calculations have been performed to investigate the interplay between the cation–π interaction and lithium bonding in the M+ ··· phenyl lithium ··· OH2 and M+ ··· phenyl lithium ··· NH3 (M = Li, Na, K) complexes. The cation–π interaction and lithium bonding in the trimers become stronger relative to the dimers. The interaction energy of cation–π interaction is increased by about 4.4–6.3%, while that of lithium bonding is increased by about 5.2–15.9%. The cooperative energy becomes larger for the stronger cation–π interaction and lithium bond. The F atom and methyl group in the phenyl ring impose a reverse effect on the cation–π interaction and lithium bond. The interaction mechanism in the complexes has been understood with the many-body interaction analysis, electrostatic potentials, and energy decomposition.

We analyze the interplay between pnicogen-bonding and halogen-bonding interactions in the XCl-FH(2)P-NH(3) (X=F, OH, CN, NC, and FCC) complex at the MP2/aug-cc-pVTZ level. Synergetic effects are observed when pnicogen and halogen bonds coexist in the same complex. These effects are studied in terms of geometric and energetic features of the complexes. Natural bond orbital theory and Bader's theory of "atoms in molecules" are used to characterize the interactions and analyze their enhancement with varying electron density at critical points and orbital interactions. The physical nature of the interactions and the mechanism of the synergetic effects are studied using symmetry-adapted perturbation theory. By taking advantage of all the aforementioned computational methods, the present study examines how both interactions mutually influence each other.

Ab initio calculations have been performed for the complexes of benzene with HArF, HKrF, and HXeF. The computed results indicate that the complexes of benzene-HArF exist in different conformations and among them those with π-hydrogen bonds are the more stable than those with C-H···F hydrogen bonds. Interestingly, the Ar-H stretching frequency is redshifted in the more stable isomer and blueshifted in the less stable form. The Ng (Ng=Ar, Kr, and Xe) atomic number dependence of the Ng-H···π and C-H···F hydrogen bonds has been explored. The result indicates that the strength of Ng-H···π and C-H···F hydrogen bonds is weakened with the increase of Ng atomic number. Natural bond orbital analysis has been performed to understand the interaction nature, frequency shift of H-Ng stretch, and dependence of Ng-H···π and C-H···F hydrogen bonds on the Ng atomic number.

We performed the dynamic mechanical relaxation measurements in typical metallic Zr(46.75)Ti(8.25)CU(7.5)Ni(10)Be(27.5) and Ce(70)Al(10)Cu(20) supercooled liquids close to their glass transition temperature T(g). An obvious excess wing is observed both in temperature- and frequency-dependent loss modulus curves by the calculation of the relaxation time of cc-relaxation in supercooled liquids using the Kohlrausch-Williams-Watts equation in combination with the Vogel-Fulcher-Tamman equation. The results support that the slow beta-relaxation process exists in the metallic liquids and the excess wing is the high-frequency flank of the beta-relaxation. The existence of beta-relaxation in the metallic supercooled liquids affirms that the beta-relaxation process arises from the small-scale translational motions of atoms which are hindered in its metastable atomic solid-like islands. (c) 2006 Elsevier B.V. All rights reserved.

Hydrogen storage alloys Mg2Ni and Mg2NiH4 were synthesized at below 733 K by the process HCS. The product was examined by X-Ray diffraction and hydriding / dehydriding dynamics was tested. The result reveals that (1) High pure products of Mg2Ni and Mg2NiH4 can be obtained even at temperature 673 K and 0.1 MPa argon and 1.0 MPa hydrogen, respectively; (2) Both products are high active absorbing hydrogen > 3.2 mass % at 603 K without activation process. The result is very attractive due to the low temperature and pressure for the production of hydrogen storage alloys.

A new cell line was established from half-smooth tongue sole Cynoglossus semilaevis pseudomale gonad (CSPMG). Primary culture was initiated from gonad tissues pieces, and the CSPMG cells were cultured at 24 °C in Dulbecco's modified Eagle medium/F12 medium (1:1) (pH7.0), supplemented with 20 % fetal bovine serum, basic fibroblast growth factor, epidermal growth factor, insulin-like growth factor-I, 2-mercaptoethanol, penicillin and streptomycin. The cultured CSPMG cells, in fibroblast shape, proliferated to 100 % confluency 10 days later and had been subcultured to passage 109. Chromosome analyses indicated that the CSPMG cells exhibited chromosomal aneuploidy with a modal chromosome number of 42, which displayed the normal diploid karyotype of half-smooth tongue sole (2n = 42t, NF = 42). Reverse transcription polymerase chain reaction revealed CSPMG cells could express gonad somatic cell functional genes Sox9a, Wt1a and weakly germ cell marker gene Vasa, but not male specific gene Dmrt1. Transfection experiment demonstrated that CSPMG cells transfected with pEGFP-N3 plasmid and small RNA could express green and red fluorescence signals with high transfection efficiency. In conclusion, a continuous CSPMG cell line has been established successfully. The cell line might serve as a valuable tool for studies on the mechanism of sex determination, sex reversal and gonad development in flatfish.

Poly(p-phenylene terephtalamide) (PPTA), a high-performance polymer with high modulus and good hydrophilicity, is often used as a reinforced material. However, due to its high crystallity, micro-phase separation often occurs in the blends. In this paper, PPTA/poly(vinylidene fluoride) (PVDF) compatible blend solution was synthesized by in situ polycondensation. Blend ultra-filtration membrane was prepared through the immersion phase inversion process. In order to obtain desired pore structure, the effects of different additives including hydrophilic polymer (polyethylene glycol (PEG)), inorganic salt (lithium chloride (LiCl)) and the surfactant (Tween-80) on the morphology and performance of PPTA/PVDF blend membranes were studied. The membrane formation process was investigated through ternary phase diagram (thermodynamics) and viscosities (kinetics) analysis. It was found that, with the increasing of LiCl content, a porous membrane structure with long finger-like pores was formed due to the accelerated demixing process which resulted in the increase of porosity and pore diameter as well as the enhancement of water flux and the decline of PEG rejection. When Tween content increased to over 3 wt%, dynamic viscosity became the main factor resulting in a decreased phase separation rate. The transfer of PEG and LiCl molecules onto membrane surface increased the surface hydrophilicity. The effect of Tween content on membrane hydrophilicity was also correlated with the compatibility of blend components.

In this paper, the cooperative effect of halogen bond with hydrogen bond has been used to make a halogen bond in FCl-CNH dimer vary from a chlorine-shared one to an ion-pair one. The halogen bond is strengthened in FCl-CNH-CNH trimer and its maximal interaction energy equals to -76 kJ/mol when the number of CNH in FCl-CNH-(CNH)(n) polymer approaches infinity. Once the free H atom in FCl-CNH-CNH trimer is replaced with alkali metals, the halogen bond becomes strong enough to be an ion-pair one in FCl-CNH-CNLi and FCl-CNH-CNNa trimers. An introduction of a Lewis acid in FCl-CNH dimer has a more prominent effect on the type of halogen bond. A prominent cooperative effect is found for the halogen bond and hydrogen bond in the trimers. FH-FCl-CNH-CNH and FH-FCl-CNH-CNLi tetramers have also been studied and the interaction energy of halogen bonding in FH-FCl-CNH-CNLi tetramer is about 12 times as much as that in the FCl-CNH dimer. The atoms in molecules and natural bond orbital analyses have been carried out for these complexes to understand the nature of halogen bond and the origin of the cooperativity.

The NCX-NCI-HMY (X=H, Cl, Br, I, Li; M=Be, Mg; Y=H, Li, Na) trimers are investigated to find ways to enhance the iodine–hydride interaction. The interaction energy in the NCI–HMH dimer is −2.87 and −5.87 kcal mol−1 for M=Be and Mg, respectively. When the free H atom in the NCI–HMH dimer is replaced with an alkali atom, the interaction energy is enhanced greatly. When NCX is added into this dimer, the interaction energy of the iodine–hydride interaction is increased by 9–45 % and its increased percentage follows the order X=Cl

The DMSO-XY (XY=ClF and BrF) complexes have been investigated with quantum chemical calculations. In general, two minima complexes were found, one with an O···X halogen bond and the other one with a S···X halogen bond. The former is more stable than the latter. Additionally, one first order saddle point complex was also observed. The interaction energies in the S complexes suffer a prominent influence from the calculation methods. At the CCSD(T)/aug-cc-pVDZ level, the interaction energies are calculated to be -9.19 and -12.73 kcal/mol for the Cl and Br global minima, respectively. Both complexes have also been evidenced to be stable at room temperature. The SO stretch vibration exhibits a red shift at the global minimum but a blue shift at the local minimum, whereas the CSC and CH stretch vibrations move to high frequency in both cases. The energy decomposition analyses indicate that the electrostatic interaction plays a dominant role in stabilizing these halogen-bonded complexes.

A 10-hydroxycamptothecin-encapsulated magnetic nanovehicle (HEMN) was fabricated by coencapsulating Fe(3)O(4) nanoparticles and 10-hydroxycamptothecin (HCPT) into a micelle core self-assembled from the amphiphilic copolymer methoxy-poly(ethylene glycol)-poly(d,l-lactide-co-glycolide) through a facile dialysis method. A satisfactory drug-loading content of (9.03 ± 0.67) % and a relatively high encapsulation efficiency of (53.52 ± 6.46) % were achieved. In vitro drug release was performed by membrane dialysis and a pH-dependent release behavior was observed. In comparison with free HCPT dissolved in dimethylsulfoxide, HEMNs showed a greatly improved in vitro antitumor efficacy against three different human cancer cell lines-HeLa, A549, and HepG2-and lower IC(50) values were measured. The mechanism of cell death was investigated, and it was clearly demonstrated that the apoptosis process was triggered. An in vitro wound-healing assay and a transwell assay indicated that HEMNs exerted much stronger activity in inhibiting HeLa cell migration. The cellular uptake of HEMNs in a desired area can be significantly enhanced by an external magnetic field. These results demonstrate HCPT-encapsulated magnetic nanovehicles might have important potential in clinical applications for inhibiting tumor metastasis and for targeted drug delivery.

A pnicogen-hydride interaction has been predicted and characterized in FH(2)P-HM and FH(2)As-HM (M = ZnH, BeH, MgH, Li, and Na) complexes at the MP2/aug-cc-pVTZ level. For the complexes analyzed here, P(As) and HM are treated as a Lewis acid and a Lewis base, respectively. This interaction is moderate or strong since, for the strongest interaction of the FH(2)As-HNa complex, the interaction energy amounts to -24.79 kcal/mol, and the binding distance is equal to about 1.7 A, much less than the sum of the corresponding van der Waals radii. By comparison with some related systems, it is concluded that the pnicogen-hydride interactions are stronger than dihydrogen bonds and lithium-hydride interactions. This interaction has been analyzed with natural bond orbitals, atoms in molecules, electron localization function, and symmetry adapted perturbation theory methods.