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Background. Colitis-associated colorectal cancer (CAC) develops from active colonic inflammation, which is characterized by the production of proinflammatory cytokines that can induce mutations. IL-6 is produced by multiple cell types located within the tumor microenvironment including tumor-infiltrating immune cells, stromal cells, and the tumor cells themselves. The aim of our study was to explore the mechanism of Feng-Liao-Chang-Wei-Kang (FLCWK) and 5-fluorouracil (5-FU) in treating CAC. Method. HCT116 cells were treated with 5-FU in the absence or presence of FLCWK. Cell proliferation was assayed by MTT assays. Apoptosis and the cell cycle phases were detected by flow cytometry. Western blotting and Q-PCR assays were used to detect the expression levels of proteins and genes related to the IL-6/STAT3 signalling pathway. A mouse model for CAC was established by treating animals with 12.5 mg/kg azoxymethane (AOM) followed by 3 cycles of 2.5% dextran sodium sulphate (DSS). The associated pathological changes were determined after haematoxylin and eosin (H&E) staining. The expression of related proteins and genes in various tissues was examined using immunofluorescence techniques. Results. FLCWK enhanced the ability of 5-FU to promote apoptosis by inhibiting the proliferation of HCT116 cells and blocking the IL-6/STAT3 pathway. FLCWK combined with 5-FU reduced the number and size of colon tumors in mice with CAC and significantly increased their survival rate. In the CAC model, FLCWK synergized with 5-FU to inhibit the phosphorylation of STAT3, preventing IL-6/STAT3 signal transduction and thus further inducing apoptosis and inhibition of colon cancer cell proliferation. Conclusion. FLCWK can inhibit the activation of STAT3 by reducing the production of IL-6, thereby increasing the occurrence of colitis-related colorectal cancer with 5-FU.

The prognosis of patients with acute myeloid leukemia (AML) caused by the FLT3-ITD mutation is poor. Arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) can down-regulate FLT3-ITD level and selectively kill leukemia cells carrying the FLT3-ITD mutation. However, the mechanisms of action of these two compounds are unknown. Here, we found that ATO could bind FLT3-ITD at Lys91 and Asp225, whereas ATRA could bind FLT3-ITD at Lys5 and Gln6. Both compounds could not bind wild-type FLT3. Further studies revealed that ATO/ATRA may suppress the Expression of FLT3-ITD by promoting the UBE2L6-mediated ubiquitination pathway and decreasing the expression of C-MYC. However, further studies are needed to define the mechanisms of these compounds on AML. Our research provides an experimental basis for the use of ATO/ATRA in FLT3-ITD AML in clinical practice.

The solubilities of water in various hydrocarbons are usually needed to assess the water content in oil products. Because the solubilities of water in hydrocarbons are very small, which usually leads to large deviations in experiments, and because we have trouble carrying out experiments on bulk hydrocarbons, it is necessary to develop a more convenient molecular simulation approach to predict the solubility. In this paper, COSMO-RS, a statistical thermodynamic method based on quantum chemistry, has been employed to obtain the solubilities of water in n-alkanes, alkylcyclohexanes, alkylbenzenes and 1-alkenes by calculating the difference of the thermodynamic properties during the dissolution process. The predictions of COSMO-RS were compared with the experimental data, as well as those of API correlations and the Tsonopoulos correlation. The results indicate that COSMO-RS can better predict the trends of the solubility with high accuracy, where the deviations are within ± 29.41%. The characteristics of the solubilities of water in various hydrocarbons are interpreted systemically, especially for the influence of carbon number, CN. It particularly focuses on the non-monotonicity of the solubility curves of water in n-alkanes with the increase of CN. In addition, the effect of temperature on the characteristic of solubility is simultaneously investigated.

Phosphoribosyl pyrophosphate synthetases 2 (PRPS2) protein function as nucleotide synthesis enzyme that plays vital roles in cancer biology. However, the expression profile and function of PRPS2 in prostate cancer (PCa) remain to be identified. Here we investigated the expression of PRPS2 protein in human PCa and paired normal tissues by immunohistochemistry, meanwhile the regulatory effects on cell proliferation, apoptosis and growth of xenograft tumors in nude mice were evaluated in PCa cells with PRPS2 depletion. Moreover, the signaling pathways were also explored by western blot analysis and quantitative polymerase chain reaction assays. We found that PRPS2 was dramatically upregulated in prostate adenocarcinoma tissues in comparison with normal tissues, and that increased PRPS2 was linked intimately to advanced clinical stage and pT status. Functional experiments showed that knockdown of PRPS2 significantly suppressed cell growth both in vitro and in vivo. In addition, depletion of PRPS2 induced G1 phase cell cycle arrest and elevated cell apoptosis. Silencing of PRPS2 resulted in the decreased expression of Bcl‑2 and cyclinD1 and increased levels of Bax, cleavage of caspases‑3, caspases‑9 and PARP. Furthermore, we also detected PRPS2 expression was significantly induced after DHT treatment, which implied the important role of PRPS2 in oncogenesis of PCa. Taken together, our findings elucidated that PRPS2 may be a potential novel candidate for PCa therapy.

A series of adjustable long chain branching poly(L-lactide)s (b-PLAs) was prepared by reactive processing of linear PLA using pyromellitic dianhydride (PMDA) and polyfunctional epoxy ether (PFE) as the branching agent and their vascular stents were fabricated via 3D-printing. Fourier-transform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC) results indicated that the chain branching reaction occurs and the average molecular weight increases obviously after the chain branching reaction. Rheological tests on the b-PLAs demonstrated that they are composed of a symmetric- or asymmetric-star, or tree-like chain configuration. The volume fraction of the branching structure of the chains increased from 0.03 to 0.3 with increasing branching agent content. The effects of the branching structure on the melt crystallization behavior of b-PLAs were investigated by means of differential scanning calorimetry (DSC). The isothermal crystallization results showed that the half-time of crystallization (t1/2) of the samples decreased from 16.8 min for linear PLA to 2.3 min when the branching agent content was 2 wt% at 106 °C. Also, as observed from polarized optical microscopy experiments, the nucleation density of the b-PLAs significantly increased with increasing volume fraction of the branching structure because the enrichment of segments around the branching structure facilitated nucleation, thus the b-PLA samples have a higher probability to form a primary nucleus than linear PLA. Moreover, mechanical testing demonstrated that forming the branching structure enabled the effective modification of the mechanical properties of PLA. The microstructures with a smaller spherulite size and higher crystallinity of the b-PLAs improved their tensile strength and modulus from 45.7 MPa and 1.63 GPa to 77.2 MPa and 3.41 GPa, respectively. Furthermore, the radial force performance of the 3D printed b-PLA vascular stents was enhanced from 4.8 to 13.7 N by the branching structure of the chains. The CCK-8 assay results indicated that the osteoblast activity of b-PLA is higher than that of linear PLA, and the scanning electron microscopy (SEM) results also indicated that b-PLA was covered and flattened with a better attachment morphology for the osteoblasts than PLA. Therefore, the b-PLAs with a long chain branching structure could effectively facilitate cell growth, proliferation, and differentiation.

Epigallocatechin gallate (EGCG) is associated with various health benefits. In this review, we searched current work about the effects of EGCG and its wound dressings on skin for wound healing. Hydrogels, nanoparticles, micro/nanofiber networks and microneedles are the major types of EGCG-containing wound dressings. The beneficial effects of EGCG and its wound dressings at different stages of skin wound healing (hemostasis, inflammation, proliferation and tissue remodeling) were summarized based on the underlying mechanisms of antioxidant, anti-inflammatory, antimicrobial, angiogenesis and antifibrotic properties. This review expatiates on the rationale of using EGCG to promote skin wound healing and prevent scar formation, which provides a future clinical application direction of EGCG.

Nacre-mimicking layered organic/inorganic hybrid materials exhibiting ultrahigh stiffness and strength frequently require multistep processing that is restricted to polar and even water-soluble polymers. Herein, nacre-mimetic hydrocarbon composites were fabricated by single-step injection molding. The key intermediates are organophilic ultrathin γ-Al(OH)3 (O-gibbsite) single-crystal nanoplatelets and all-hydrocarbon composites (All-PE) containing aligned, extended-chain ultrahigh-molecular-weight polyethylene (UHMWPE) as one-dimensional (1D) nanostructures embedded in a polyethylene (PE) matrix. This formation of flow-induced UHMWPE 1D nanostructures mimics chitin nanofibers in nacre and drives the alignment of O-gibbsite nanoplatelets to assemble bricks. Unprecedented high contents of up to 70 wt % O-gibbsite nanoplatelets are tolerated in injection molding. As verified by focused ion beam-scanning electron microscopy (FIB-SEM), the resulting brick-and-mortar architectures contain aligned O-gibbsite as b...

Multimodal molar mass distributions (MWD) of high-density polyethylene (HDPE) were tailored either by reactor cascade technology using a chain transfer agent or by multisite polymerization catalysi...

No existing method to characterize transcription factor (TF) binding to DNA allows genome-wide measurement of all TF-binding activity in cells. Here we present a massively parallel protein activity assay, active TF identification (ATI), that measures the DNA-binding activity of all TFs in cell or tissue extracts. ATI is based on electrophoretic separation of protein-bound DNA sequences from a highly complex DNA library and subsequent mass-spectrometric identification of the DNA-bound proteins. We applied ATI to four mouse tissues and mouse embryonic stem cells and found that, in a given tissue or cell type, a small set of TFs, which bound to only ∼10 distinct motifs, displayed strong DNA-binding activity. Some of these TFs were found in all cell types, whereas others were specific TFs known to determine cell fate in the analyzed tissue or cell type. We also show that a small number of TFs determined the accessible chromatin landscape of a cell, suggesting that gene regulatory logic may be simpler than previously appreciated.

Nanophase separation during injection molding of high density polyethylene (HDPE) together with polyethylene reactor blend (RB) additives that have ultrabroad bimodal molar mass distribution and a high content of ultrahigh molar mass polyethylene (UHMWPE), produces thermoplastic all-polyethylene composites reinforced with extended-chain UHMWPE nanostructures formed in situ. Neither alien fibers, inorganic fillers, hazardous nanoparticles nor modified single- and multi-step molding processes are required to convert HDPE into higher performance engineering plastics. The RB40 additive is readily tailored by ethylene polymerization on silica-supported chromium two-site catalysts and contains 40 wt% UHMWPE (Mw = 1.5 × 106 g∙mol−1) dispersed in 50 wt% HDPE wax (Mw = 1.1 × 103 g∙mol−1). The presence of disentangled nanophase-separated UHMWPE together with HDPE wax serving as a processing aid enables injection molding of all-PE composites with high UHMWPE content of up to 24 wt% without changing processing parameters typical for HDPE. As verified by both scanning electron microscopic analyses of samples etched with hot xylene and thermal analysis, the HDPE matrix is efficiently reinforced by in situ formed polyethylene shish-kebab fibers where flow-induced crystallization yields extended-chain UHMWPE nanostructures as shish nucleating the crystallization of HDPE kebab. For the first time, by etching quenched samples, it was possible to completely suppress kebab formation and to image in situ extended-chain UHMWPE shish with an average diameter of 80 nm. Upon increasing the UHMPE content the average total diameter of shish-kebab fiber-like structures drastically decreases from micron to nanometer range, forming non-woven-like architectures. This self-reinforcement simultaneously improves toughness, stiffness and strength parameters unparalleled by conventional melt-blending HDPE with micron-sized UHMWPE and HDPE wax. Compared to HDPE, the addition of 60 wt% RB40 increases the Young's modulus to 4.2 GPa, tensile strength to 160 MPa and impact strength to 20 kJ/m2. This sustainable route to self-reinforced all-PE composite composites preserves the high energy, resource, cost and eco-efficiencies typical for pure hydrocarbon resins. Here, we examine the impact of RB40 addition on in situ nanostructure formation and its correlation with thermal and mechanical properties of all-PE composites.

A pair of stereoisomers possessing novel structures with 6/6/5 fused-ring systems, neo-debromoaplysiatoxin E (1) and neo-debromoaplysiatoxin F (2), were isolated from the marine cyanobacterium Lyngbya sp. Their structures were elucidated using various spectroscopic techniques including high resolution electrospray ionization mass spectroscopy (HRESIMS) and nuclear magnetic resonance (NMR). The absolute stereochemistry was determined by calculated electronic circular dichroism (ECD) and gauge-independent atomic orbital (GIAO) NMR shift calculation followed by DP4+ analysis. Significantly, this is the first report on aplysiatoxin derivatives with different absolute configurations at C9&ndash, C12 (1: 9S, 10R, 11S, 12S, 2: 9R, 10S, 11R, 12R). Compounds 1 and 2 exhibited potent blocking activities against Kv1.5 with IC50 values of 1.22 &plusmn, 0.22 &mu, M and 2.85 &plusmn, 0.29 &mu, M, respectively.

Background Pancreatic cancer (PC) is the fourth leading cause of cancer death because of its subtle clinical symptoms in the early stage. To discover particular serum metabolites as potential biomarkers to differentiate pancreatic carcinoma from benign disease (BD) is on urgent demand. Method To comprehensively analyze serum metabolites obtained from 14 patients with PC, 10 patients with BD and 10 healthy individuals (normal control, NC), we separated the metabolites using both reversed-phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC). The data were acquired on a high-resolution quadrupole time-of-flight mass spectrometer operated in negative (ESI–) and positive (ESI+) ionization modes, respectively. Differential metabolites were selected by univariate (Student’s t test) and multivariate (orthogonal partial least squares-discriminant analysis (OPLS-DA)) statistics. Sequential window acquisition of all theoretical spectra (SWATH) analysis was further utilized to validate the metabolites found in discovery stage. The receiver operator characteristics (ROC) curve analysis was performed to evaluate predictive clinical usefulness of 8 metabolites. Results A total of 8 metabolites including taurocholic acid, glycochenodexycholic acid, glycocholic acid, L-glutamine, glutamic acid, L-phenylalanine, L-tryptophan, and L-arginine were identified and relatively quantified as differential metabolites for discriminating PC, BD and NC. The 8 metabolites and their combination discriminated PC from BD and NC with well-performed area under the curve (AUC) values, sensitivity and specificity. Conclusion Bile acids (especially taurocholic acid) performed to be potential biomarkers in PC diagnosis. Other amino acids (such as L-glutamine, glutamic acid, L-phenylalanine, L-tryptophan, and L-arginine) in serum samples from PC patients might provide a sensitive, blood-borne diagnostic signature for the presence of PC or its precursor lesions.

Rheological investigation of polyethylene (PE) blends with a significant amount (up to 50 wt. %) of ultrahigh molecular weight PE (UHMWPE, with weight average molecular weight Mw > 106 g/mol) was not accessible so far. The development of special Enders catalysts allows the synthesis of such homogeneous PE reactor blends (RBs). In this paper, by melt blending of RBs with high-density PE polymer matrix, multimodal PE blends were prepared and their rheological properties were investigated. The analysis grants access to better understand how notably high amount of UHMWPE and ultra-broad molecular weight distribution displaying extremely high polydispersity, Ð ∼ 1000, influence the linear viscoelasticity. Moreover, taking advantage of the opportunities offered by molecular models, applying the tube-based time-marching algorithm, the “rheological” molecular weight distribution (MWD) of multimodal PE blends was determined, overcoming drawbacks of high-temperature size exclusion chromatography. Analyzing the zero-shear viscosity, η 0, versus Mw scaling relation for blends of any MWD, a correction scheme was developed which allows to take into account the Ð effects on η 0 properly. The analysis revealed that in a double logarithmic plot versus Mw, corrected η 0 shows a unique linear dependency with a slope of 3.6 if Mw is smaller than the reptation molecular weight (Mr). If Mw > Mr, the slope of this linear dependency turns into 3. The analysis of transition zone between the two linear dependencies allowed the experimental determination of PEs Mr.Rheological investigation of polyethylene (PE) blends with a significant amount (up to 50 wt. %) of ultrahigh molecular weight PE (UHMWPE, with weight average molecular weight Mw > 106 g/mol) was not accessible so far. The development of special Enders catalysts allows the synthesis of such homogeneous PE reactor blends (RBs). In this paper, by melt blending of RBs with high-density PE polymer matrix, multimodal PE blends were prepared and their rheological properties were investigated. The analysis grants access to better understand how notably high amount of UHMWPE and ultra-broad molecular weight distribution displaying extremely high polydispersity, Ð ∼ 1000, influence the linear viscoelasticity. Moreover, taking advantage of the opportunities offered by molecular models, applying the tube-based time-marching algorithm, the “rheological” molecular weight distribution (MWD) of multimodal PE blends was determined, overcoming drawbacks of high-temperature size exclusion chromatography. Analyzing the zero...

Melt-flow-induced crystallization of polyethylene blends having tailored ultrabroad molar mass distribution affords extended-chain ultrahigh molar mass (UHMWPE) nanophases resembling nanofibers which effectively reinforce the polyethylene matrix. Unparalleled by state-of-the-art high density polyethylene (HDPE), the resulting melt-processable “all-polyethylene” single component composites exhibit simultaneously improved wear resistance, toughness, stiffness and strength. Key intermediates are trimodal blends prepared by melt compounding HDPE with bimodal UHMWPE/HDPE wax reactor blends (RB) readily tailored by ethylene polymerization on supported two-site catalysts. Whereas HDPE wax, varied up to 54 wt.-%, serves as processing aid lowering melt viscosity, UHMWPE varied up to 63 wt.-% accounts for improved blend properties. UHMWPE platelet-like nanophase separate during ethylene polymerization and readily melt during injection molding of RB/HDPE blends producing extended-chain fiber-like UHMWPE nanostructures of 100 nm diameter as shish which nucleate HDPE and HDPE wax crystallization to form shish-kebab-like structures. At 32 wt.-% UHMWPE content shish-kebab-like reinforcing phases account for massive polyethylene self-reinforcement as reflected by improved Young's modulus (+420%), tensile strength (+740%) and notched Izod impact strength (+650%) without impairing HDPE injection molding. All-PE composites exhibit high wear resistance entering ranges typical for polyamide and monomodal UHMWPE which is not processable by injection molding under identical conditions.

It is well established that transcription factors (TFs) play crucial roles in determining cell identity, and that a large fraction of all TFs are expressed in most cell types. In order to globally characterize activities of TFs in cells, we have developed a novel massively parallel protein activity assay, Active TF Identification (ATI) that measures DNA-binding activity of all TFs from any species or tissue type. In contrast to previous studies based on mRNA expression or protein abundance, we found that a set of TFs binding to only around ten distinct motifs display strong DNA-binding activity in any given cell or tissue type. Mass spectrometric identification of TFs revealed that within these highly active TFs, there were both housekeeping TFs, which were universally found in all cell types, and specific TFs, which were highly enriched in known factors that determine the fate of the analyzed tissue or cell type. The importance of a small subset of TFs for determining the overall accessible chromatin landscape of a cell suggests that gene regulatory logic may be simpler than what has previously been appreciated.

INTRODUCTION Nearly all cells in the human body share the same primary genome sequence consisting of four nucleotide bases. One of the bases, cytosine, is commonly modified by methylation of its 5 position in CpG dinucleotides (mCpG). Most CpG dinucleotides in the human genome are methylated, but the level of CpG methylation varies with genetic location (promoter versus gene body), whether genes are active versus silenced, and cell type. Research has shown that the maintenance of a particular cellular state after cell division is dependent on faithful transmission of methylated CpGs, as well as inheritance of the mother cells’ repertoire of transcription factors by the daughter cells. These two mechanisms of epigenetic inheritance are linked to each other; the binding of transcription factors can be affected by cytosine methylation, and cytosine methylation can, in turn, be added or removed by proteins that associate with transcription factors. RATIONALE The genetic and epigenetic language, which imparts when and where genes are expressed, is understood at a conceptual level. However, a more detailed understanding is needed of the genomic regulatory mechanism by which methylated cytosines affect transcription factor binding. Because cytosine methylation changes DNA structure, it has the potential to affect binding of all transcription factors. However, a systematic analysis of binding of a large collection of transcription factors to all possible DNA sequences has not previously been conducted. RESULTS To globally characterize the effect of cytosine methylation on transcription factor binding, we systematically analyzed binding specificities of full-length transcription factors and extended DNA binding domains to unmethylated and CpG-methylated DNA by using methylation-sensitive SELEX (systematic evolution of ligands by exponential enrichment). We evaluated binding of 542 transcription factors and identified a large number of previously uncharacterized transcription factor recognition motifs. Binding of most major classes of transcription factors, including bHLH, bZIP, and ETS, was inhibited by mCpG. In contrast, transcription factors such as homeodomain, POU, and NFAT proteins preferred to bind methylated DNA. This class of binding was enriched in factors with central roles in embryonic and organismal development. The observed binding preferences were validated using several orthogonal methods, including bisulfite-SELEX and protein-binding microarrays. In addition, the preference of the pluripotency factor OCT4 to bind to a mCpG-containing motif was confirmed by chromatin immunoprecipitation analysis in mouse embryonic stem cells with low or high levels of CpG methylation (due to deficiency in all enzymes that methylate cytosines or contribute to their removal, respectively). Crystal structure analysis of the homeodomain proteins HOXB13, CDX1, CDX2, and LHX4 revealed three key residues that contribute to the preference of this developmentally important family of transcription factors for mCpG. The preference for binding to mCpG was due to direct hydrophobic interactions with the 5-methyl group of methylcytosine. In contrast, inhibition of binding of other transcription factors to methylated sequences was found to be caused by steric hindrance. CONCLUSION Our work constitutes a global analysis of the effect of cytosine methylation on DNA binding specificities of human transcription factors. CpG methylation can influence binding of most transcription factors to DNA—in some cases negatively and in others positively. Our finding that many developmentally important transcription factors prefer to bind to mCpG sites can inform future analyses of the role of DNA methylation on cell differentiation, chromatin reprogramming, and transcriptional regulation.

Hepatoma-derived growth factor (HDGF) is a growth factor related to normal development and tumorigenesis; however, the mechanism of its mitogenic and angiogenic activity still remains unknown. Analysis of the HDGF interactome could be important for understanding its function and integrative mechanisms, because knowledge about HDGF interactors is very limited. In this study, through streptavidin-binding peptide (SBP) and Flag tag-based tandem affinity purification (SBP/Flag-TAP) coupled with LC-MS/MS, 106 proteins were shown to form complexes with HDGF. RNAs were also found in the HDGF complex through the SBP-tag based RNA co-immunoprecipitation (SBP-RIP) assay. Some of these interactions were confirmed by Co-IP and RT-PCR. We then found that the HATH domain was essential for HDGF interactions including protein-protein and protein-RNA interactions, and that in the absence of the HATH domain, NO-HATH could not form complex. The interactome suggests that HDGF is a multifunctional protein and participates in many cellular events, including ribosome biogenesis, RNA processing, DNA damage repair and transcriptional regulation. This new information about the HDGF interactome will further our understanding on HDGF-mediated cellular functions.

A novel helical-chain coordination polymer [Co(tau)2(4,4′-bipy)]n·nH2O 1 (tau = taurine, 4,4′-bipy = 4,4′-bipyridine) has been hydrothermally synthesized and characterized by infrared spectroscopy, and thermogravimetric analysis, magnetic measurements, solid-state CD spectra and single crystal X-ray diffraction analysis. The intertwist trigonal-fold helical chains are further connected through hydrogen bonds to give a three-dimensional supramolecular network, in which trigonal microporous channels filled with water guest molecules exist within the polymer coils. Compound 1 shows weak antiferromagnetic interactions among metal ions.

Three new iron(III) citrate complexes [Fe2(cit)2(H2O)2](H2bpa) (1), [Fe2(cit)2(H2O)2](H2bpe) (2) and [Fe4(cit)4(H2O)4](H2bpp)2(H2O) (3) (cit = C(O−)(COO−)(CH2COO−)2, bpa = 1,3-bis(4-pyridyl)ethane, bpe = 1,3-bis(4-pyridyl)ethene, bpp = 1,3-bis(4-pyridyl)propane) were synthesized and characterized by elemental analysis, spectroscopic techniques and magnetic properties. Single X-ray diffraction analyses in the 1–3 complexes reveal that the iron ion is six-coordinated and is bound by two deprotonated citrates and a pair of aqua ligands in a distorted octahedral fashion. The anionic complex contains a centro-symmetrical planar of four-membered Fe2O2 ring. There are significant contributions to the stabilities of the assembled lattices in 1–3 arising from the protonated pyridine analogue counterions neutralizing the anionic charges of the complexes. The units in the complexes are connected together via hydrogen bonding to form 3D supramolecular networks. The supramolecular structures of 1–2 show alternating R 6 6 ( 50 ) and R 6 4 ( 48 ) motif linking the anionic moieties which are in turn interwoven with cationic moieties, while 3 shows alternating R 6 6 ( 51 ) and R 6 4 ( 49 ) motif. The magnetic properties of 1–3 are investigated and discussed in detail.

The new complex {[Cu(dde)(bpe)] · H2O}n (1) (dde = 4,4′-dicarboxydiphenyl ether, bpe = 1,2-bis(4-pyridyl)ethene) has been synthesized and characterized. It exhibits a novel (2D → 3D) three-fold parallel interpenetrating architecture that is obtained for the first time from the self-assembly of grid-containing 2D (4, 4) layer motifs. The fluorescent property of 1 is discussed.

The self-assembly of Cu2+ ions with malate and 1,3-bis(4-pyridyl)propane (bpp) affords a 3D coordination polymer {[Cu(Hmal)(bpp) · 6H2O]}n (1) (malic acid = H3mal). The metal ions were interconnected by α- and β-carboxylate of malate produce infinite [Cu(C4H4O5)]n layers, which were further pillared by bridging ligand bpp molecules to form a 3D interpenetrating network. Of further interest, lattice water molecules form 1D infinite water tapes in 1D open cavities.

Single and pauci chain aggregates of isotactic polystyrene (i-PS) were prepared by the freeze-drying process from dilute solutions with the concentration from 1×10−3 to 2×10−5 g/mL. It was found by DSC measurements that the melting point of samples gradually shifted to lower temperatures with the decrease of the solution concentration used for sample preparation. As a result, the lamella thickness of bulk samples and the samples prepared by the freeze-drying process from a solution of 2×10−5 g/mL was 19.3 and 12.6 nm, respectively. At 468.3 K the half crystallization time (t1/2) of samples freeze-dried from a solution of 1×10−4 g/mL was about 36 s, which was merely one tenth of that of the bulk sample. In addition, the growth rate of spherulite (dr/dt) of samples prepared from a solution of 2×10−5 g/mL was faster than that of the bulk sample annealed at 478.3 K. All these results should be attributed to the fewer entanglements in samples prepared by freeze-drying process from dilute solutions, and presented clear evidence for the influence of chain entanglements on the crystallization behavior of polymers.

Nonanuclear nickel(II) cage complex is reported, in which carbonate anions exhibit μ6 coordination mode. The core is arranged as a tricapped trigonal prism of nickel atoms, and held in place by six acetates, six hydroxides and two carbonates.

Aerogels of nanocellulose (NC) prepared by freeze-drying of cellulose nanofibrils (CNF) hydrogels and followed by impregnation with methylaluminoxane serve as nanoporous organic supports for immobilizing single site iron catalysts such as bisiminopyridine iron(II) complexes. The resulting catalyst systems, exploiting renewable biomaterials as organic supports, are highly active in low pressure ethylene polymerization. They afford simultaneous control of high density polyethylene (HDPE) particle morphology and facile NC dispersion within the HDPE matrix. In the early stage of ethylene polymerization, mesoscopic shape replication and NC-mediated templating yield platelets containing an NC core and a HDPE shell, as confirmed by scanning electron microscopy (SEM) of virgin polyethylene powders. Opposite to conventionally dried CNF hydrogels, forming large agglomerates, this facile NC aerogel-mediated in situ NC/HDPE nanocomposite formation is vastly superior to melt compounding of HDPE with NC, failing to produce such fine NC dispersions. On increasing NC content to 3.0 wt%, both Young's modulus (+50%) and tensile strength (+40%) increase at the expense of elongation at break (−80%). According to the SEM analysis of NC/HDPE morphology, the dispersion of NC nanosheets together with the in situ formation of “shish-kebab” polyethylene fiber-like structures accounted for HDPE matrix reinforcement.

The title compound, [Cd(C(8)H(18)NO(8)P(2))(2)](n), synthesized by hydrothermal methods, exhibits a layered structure in which the Cd(II) ion, occupying a centre of symmetry, is coordinated by six O atoms from four phosphonate ligands. The crosslinkage of CdO(6) octahedra by bridging phosphonate ligands results in a cadmium(II) phosphonate layer. Within the layer, there exists a 16-membered ring incorporating four -Cd-O-P-O- linkages. The uncoordinated carboxyl group of the ligand is oriented so that it penetrates the adjacent layer, taking part in hydrogen bonding to two uncoordinated phosphonate O atoms to form a CO(2)H/HO(2)P motif.

The title compound, [Gd2(C8H22N2O12P4)(C2O4)2(H2O)2]·4H2O, was synthesized by the hydro­thermal method. It exhibits a pillar–layer structure, with the layers formed by GdIII ions inter­connected by the oxalate ions and the –NH(CH2PO3H)2 units of the tetra­phospho­nate dianions. The central organic groups of the tetra­phospho­nate ligands act as the pillars. Each oxalate ion bridges two GdIII ions and each tetra­phospho­nate ligand bridges six GdIII ions. Inversion centres are located at the mid-points of the central C—C bonds of both types of ligands.

The phenomena of aggregation and coalescence of fullerenes in the UV-laser ablation time-of-flight mass spectrometric investigation of C60-modified poly(N-vinylcarbazole) both in the positive and in the negative ion channels have been observed. The results indicate that in C60 chemically modified PVK (C60–PVK) copolymer the nascent fullerene fragments ruptured from main chain can easily coalesce into large fullerenes through collisions, whereas in the C60-doped PVK the aggregation and coalescence of C60 were relative weak due to nonbounding action and incomplete charge transfer behavior between C60 and PVK. Furthermore, the photoinduced electron transfer behavior between C60 and carbazole units in the C60 chemically modified poly(N-vinylcarbazole) in benzonitrile by laser flash photolysis at 355 nm has also been investigated. Efficiency of the anion radical of C60 in copolymer at 1080 nm is higher than that of the C60-doped poly(N-vinylcarbazole) polymers. The formation of a C60 radical anion may be ascribed to photoinduced electron transfer between C60 pendanted on the main chain backbone and the inter-, and intrachain carbazole units in the copolymer. © 1997 John Wiley & Sons, Inc. 35: 1185–1190, 1997

The title triazole compound, C15H8Cl4N4S·C3H7NO, has been obtained as an unexpected product when attempting to prepare Schiff bases of thio­carbohydrazide (TCH). The triazole ring is planar within 0.004 (8) A because of conjugation. The dihedral angles between the 1,2,4-triazole ring and the two benzene rings are 24.9 (2) and 70.0 (2)°. The interplanar angle between the two benzene rings is 83.4 (2)°. The packing of the mol­ecules is stabilized both by van der Waals interactions and by N—H⋯O intermolecular hydrogen bonds between the triazole N atom and the carbonyl O atom of the di­methyl­form­amide solvent mol­ecule.

The first results using the modulated photocurrent (MPC) method in a transient mode to study deep electron trapping in a-Si:H are reported. The measurements show that the distribution of such gap states shifts monotonically to shallower thermal energies after bias light is applied, with a time of roughly 5 s to saturation at 300 K. It shifts monotonically to deeper thermal energies after the light is turned off, with a recovery time of roughly 100 s. The photoconductivity transients have also been recorded in this long time regime under identical conditions. It is found that there exists an intimate relation between the motion of the MPC peak and that of the quasi-Fermi level as deduced by the transient photoconductivity. These results thus provide direct evidence for the effects of deep defect relaxation on the trapping dynamics and the photoconductivity decay in a-Si:H.

The aerobic ammonia oxidation is an important process for nitrogen removal from wastewater with high ammonia concentration. Here, we investigated the metabolic properties of a mixed culture of aerobic ammonia oxidizers and determined its optimal reaction conditions. The maximum specific rate of NO(2)(-)-N formation of the culture was 14.9 mg N mg(protein)(-1) d(-1). The ammonia oxidation capacity was positively correlated with the microbial biomass concentration. Haldane model showed that the half-saturation constant (K(s)) for NH(4)(+)-N of the culture was 78.5 mg L(-1), and the inhibition constant (K(i)) for NH(4)(+)-N was 393.4 mg L(-1). The acetic acid and beef extract had significant inhibitory effects on ammonia oxidation, while there was little effect of methanol and glucose on ammonia oxidation. Orthogonal experiments with range analysis, variance analysis, factor contribution analysis and response surface analysis confirmed the optimal reaction conditions for ammonia oxidation to be 30-32 °C, pH 7.8-8.0, and 150-200 mg L(-1) NH(4)(+)-N concentration.

Transient capacitance measurements disclose that the mobility gap energy of the D defect in a-Si:H relaxes following a change in its charge state. Using the relaxation parameters thus determined, we solve the resulting dynamical equation to obtain the steady-state energy distributions of both the D − and D 0 sub-bands. These results agree with the experimental distributions determined by modulated photocurrent and steady-state junction capacitance measurements.

The density of states in the upper half of the mobility gap of both intrinsic and n-type a-Si:H samples was determined by the modulated photocurrent (MPC) and junction capacitance methods. We conclude that the narrow defect band revealed by the MPC measurements reflects the distribution of relaxed ${\mathit{D}}^{0}$ states, while the broader and deeper defect band obtained by capacitance measurements corresponds to relaxed ${\mathit{D}}^{\mathrm{\ensuremath{-}}}$ states. Both distributions are correctly predicted by a calculation that takes into account the relaxation dynamics of deep defects in these different charge states.

AIM: To study the effects of lysophosphatidic acid (LPA) on proliferation, adhesion, migration, and apoptosis in the human colon cancer cell line, SW480, and its mechanisms of action. METHODS: Methyl tetrazolium assay was used to assess cell proliferation. Flow cytometry was employed to detect cell apoptosis. Cell migration was measured by using a Boyden transwell migration chamber. Cell adhesion assay was performed in 96-well plates according to protocol. RESULTS: LPA significantly stimulated SW480 cell proliferation in a dose-dependent and time-dependent manner compared with the control group (P < 0.05) while the mitogen-activated protein kinase (MAPK) inhibitor, PD98059, significantly blocked the LPA stimulation effect on proliferation. LPA also significantly stimulated adhesion and migration of SW480 cells in a dose-dependent manner (P < 0.05). Rho kinase inhibitor, Y-27632, significantly inhibited the up-regulatory effect of LPA on adhesion and migration (P < 0.05). LPA significantly protected cells from apoptosis induced by the chemotherapeutic drugs, cisplatin and 5-FU (P < 0.05), but the phosphoinositide 3-kinase (PI3K) inhibitor, LY294002, significantly blocked the protective effect of LPA on apoptosis. CONCLUSION: LPA stimulated proliferation, adhesion, migration of SW480 cells, and protected from apoptosis. The Ras/Raf-MAPK, G12/13-Rho-RhoA and PI3K-AKT/PKB signal pathways may be involved.

Objectives To utilize phosphorescence to monitor hypoxic microenvironment in solid-tumors and investigate cancer chemotherapeutic effects in vivo. Methods A hypoxia-sensitive probe named BTP was used to monitor hypoxic microenvironment in solid-tumors. The low-dose metronomic treatment with cisplatin was used in anti-angiogenetic chemotherapeutic programs. The phosphorescence properties of BTP were detected by a spectrofluorometer. BTP cytotoxicity utilized cell necrosis and apoptosis, which were evaluated by trypan blue dye exclusion and Hoechst33342 plus propidium iodide assays. Tumor-bearing mouse models of colon adenocarcinoma were used for tumor imaging in vivo. Monitoring of the hypoxic microenvironment in tumors was performed with a Maestro 2 fluorescence imaging system. Tumor tissues in each group were harvested regularly and treated with pathological hematoxylin and eosin and immunohistochemical staining to confirm imaging results. Results BTP did not feature obvious cytotoxicity for cells, and tumor growth in low-dose metronomic cisplatin treated mice was significantly inhibited by chemotherapy. Hypoxic levels significantly increased due to cisplatin, as proven by the expression level of related proteins. Phosphorescence intensity in the tumors of mice in the cisplatin group was stronger and showed higher contrast than that in tumors of saline treated mice. We develop a useful phosphorescence method to evaluate the chemotherapeutic effects of cisplatin. The proposed method shows potential as a phosphorescence imaging approach for evaluating chemotherapeutic effects in vivo, especially anti-angiogenesis.

We review modulated photocurrent experiments which indicate that thermal emission rate for Do defects in intrinsic samples varies in response to changes in the Fermi-level or quasi-Fermi position. This apparent shift in energy threshold is confirmed using time resolved sub-band-gap spectroscopy. We also demonstrate that such a variation of emission rate with changes in the Fermi-level position, if present within the depletion region near a barrier junction, is consistent with the details of the temperature dependence of the junction capacitance in intrinsic samples.

Particle separation is of great importance for a wide range of applications, such as biochemistry and biomedicine, and has been demonstrated using various techniques. Generally, these techniques necessitate carefully microfabricated devices and the assistance of microfluidics, thus making the separation difficult to accomplish. Here, we report a flexible, handy, and highly efficient optical method for particle separation using two tapered optical fibers, avoiding the use of complicated devices. By launching a laser beam with a power of 80 mW and wavelength of 1.55 μm into the first tapered fiber, particles of SiO2 with a size of 3.14 μm and poly(methyl methacrylate) (PMMA) with a size of 10 μm were trapped and collected. As the laser (330 mW) was switched to the second fiber for 29 s, SiO2 and PMMA particles were separated with separation efficiencies of 89.1% and 92.4%, respectively, because of their different photophoretic velocities. The separation performance was further demonstrated using different mixtures, with all separation efficiencies higher than 78%. The separation mechanism was explained by numerical simulations.

Hydrogen or helium dilution of silane has been used to improve charge transport characteristics or deposition rate for thick amorphous silicon layers. In both cases, mechanical instability, such as peeling-off, due to high strain energy stored in the a-Si:H film is one of the major concerns. Growing the a-Si:H film at temperatures below 150°C brought the residual stress in the film to a level low enough to prevent delamination. The defect density increased at the same time, but it could be recovered by annealing at 160°C for 100 hours without affecting the stress state. In the hydrogen-diluted material, the deposition condition for optimum mobility and defect density values corresponded to the onset of the microcrystalline formation, and this relationship was confirmed by Transmission Electron Microscopy (TEM). Existence of a small amount of an ordered phase in the helium-diluted material, which was hardly observed by the TEM, was revealed by IR absorption spectra and supported by the change in ratio of photo-todark conductivity compared to that of undiluted material.

We review results obtained by employing two junction capacitance methods—drive‐level capacitance profiling and transient photocapacitance spectroscopy—to a‐Si:H and a‐Si,Ge:H alloy samples. We discuss how these measurements disclose the dominant deep defect bands and their carrier trapping dynamics in both a‐Si:H and the alloy samples. In particular these methods allow us to separate electron from hole processes and provide evidence for the existence of two distinct defect bands in the alloys. The deduced dependence of total defect density vs Ge fraction is found to agree with the predictions of a spontaneous defect formation model.

We have applied the modulated photocurrent (MPC) method over a wide range of frequencies (5Hz-100kHz) and temperatures (120K-380K) to assess its ability to accurately deduce the mobility gap distribution in a-Si:H. We have also investigated the effects of moving both the Fermi level within some samples (by light soaking and partial annealing) and the quasi-Fermi level (by applying the bias light) to observe how such changes influence the deduced density of states (DOS). We then compared the MPC results directly with the DOS determined by junction capacitance measurements in the same sample devices. We have determined general conditions under which, we believe, the MPC results provide an accurate picture of the gap state distribution. However, we found that under other conditions, the appearance of the deep defect peaks and other features do not represent the actual defect distribution but, rather, are artifacts due to recombination processes.

In the title complex, [Ni(C7H3N2O6)(C10H8N2)(H2O)]ClO4, the NiII ion adopts a distorted square-pyramidal coordination geometry, with the coordinated water mol­ecule occupying the apical position. The NiII complex cation is linked to the ClO4− anion by O—H⋯O hydrogen bonding.

A simple and sensitive method for simultaneous determination of furan and vinyl acetate (VA) in vapor phase of mainstream cigarette smoke with cold trap and gas chromatography-mass spectrometry (GC-MS) was developed. A Cambridge filter pad (CFP) was placed in front of the impingers of smoking machine to remove the particle phase from cigarette smoke. Furan and VA in vapor phase of mainstream cigarette smoke were collected in two impingers connected in series by filled with methanol at -78°C. The solutions were added with deuterium-labeled furan-d4 and VA-d6 as internal standards and analyzed by GC-MS. The results showed that the calibration curves for furan and VA were linear (r2 > 0.9995) over the studied concentration range. The intra- and inter-day precision values for furan and VA were