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An Nb3Sn cable-in-conduit (CIC) conductor with short twist pitch structure has been developed at Institute of Plasma Physics Chinese Academy of Sciences, Hefei, China, to meet the central solenoid model coil (CSMC) project of China fusion engineering test reactor (CFETR). 12 T magnetic field and 1.5 T/s field change are the most basic design target. The coupling loss characteristics of Nb3Sn CIC conductor is the key design requirement for CSMS because the deposited energy in magnets from ac losses can decrease the safe margin in the nuclear fusion device. In order to evaluate the coupling loss performance of the Nb3Sn CIC conductor, the ac loss measurement for Nb3Sn CIC conductor sample was carried out at SULTAN facility. This paper presents the specific structure design of the Nb3Sn CIC conductor and ac losses test results first. Then, the coupling losses characteristics are discussed with Multizones PArtial Shielding model and the key fit parameters are obtained from measurement results. Finally, two typical field cases are considered to evaluate the coupling loss energy of Nb3Sn CIC conductor for safe operation of the CFETR CSMC and the optimization of the cryogenic system. [ABSTRACT FROM AUTHOR]

We have investigated the gas-phase production of isoquinoline by performing collisional activation on benzalaminoacetal, the first intermediate in the classic solution-phase Pomeranz--Fritsch synthesis of isoquinoline. We have elucidated the reaction pathways in the gas phase using tandem mass spectrometry. Unlike the corresponding condensed-phase reaction, where catalytic proton exchange between intermediate(s) and solvent (Brønsted--Lowry base) is known to drive the reaction, the gas-phase reaction follows the "mobile proton model" to form the products via a number of intermediates, some the same as in their condensed-phase counterparts. Energy-resolved mass spectrometry, deuterium labeling experiments, and theoretical calculations (B3LYP/6-31G**) identified 27 different reaction routes in the gas phase, forming a complex interlinked reaction network. The experimental measurements and theoretical calculations confirm the proton hopping onto different basic sites of the precursors and intermediates to transform them ultimately into isoquinoline. [ABSTRACT FROM AUTHOR]

We computationally study the chiral transition process of the α-Ala molecule under confined different sizes of armchair SWBNNTs to explore the confinement effect. We find that the influence of a confinement environment (in armchair SWBNNTs) on the α-Ala molecule would lead to different reaction pathways. Meanwhile, the preferred reaction pathway is also different in various sizes of armchair SWBNNTs, and their energy barriers for the rate-limiting step decrease rapidly with the decreasing of the diameters of the nanotubes. It is obvious that significant decrease of the chiral transition energy barrier occurs compared with the isolated α-Ala molecule chirality conversion mechanism, by ∼15.6 kcal mol-1, highlighting the improvement in the activity the enantiomers of α-Ala molecule. We concluded that the confinement environment has a significant impact at the nanoscale on the enantiomer transformation process of the chiral molecule. [ABSTRACT FROM AUTHOR]

CtBP2 has been demonstrated to possess tumor-promoting capacities by virtue of up-regulating epithelial-mesenchymal transition (EMT) and down-regulating apoptosis in cancer cells. As a result, cellular CtBP2 levels are considered a key factor determining the outcome of oncogenic transformation. How pro-tumorigenic and anti-tumorigenic factors compete for fine-tuning CtBP2 levels is incompletely understood. Here we report that the cyclin H/cyclin-dependent kinase 7 (CCNH/CDK7) complex interacted with CtBP2 in vivo and in vitro. Depletion of either CCNH or CDK7 decreased CtBP2 protein levels by accelerating proteasome-dependent CtBP2 clearance. Further analysis revealed that CCNH/CDK7 competed with the tumor repressor HIPK2 for CtBP2 binding and consequently inhibited phosphorylation and dimerization of CtBP2. Phosphorylation-defective CtBP2 interacted more strongly with CCNH/CDK7 and was more resistant to degradation. Finally, overexpression of CtBP2 increased whereas depletion of CtBP2 dampened the invasive and migratory potential of breast cancer cells. CtBP2 promoted the invasion and migration of breast cancer cells in a CCNH-dependent manner. Taken together, our data have delineated a novel pathway that regulates CtBP2 stability, suggesting that targeting the CCNH/CDK7-CtBP2 axis may yield a viable anti-tumor strategy. [ABSTRACT FROM AUTHOR]

Using a green catalyst of luminol chemiluminescence (CL), Mg-Al-carbonate layered double hydroxides (denoted as Mg-Al-CO3LDHs), a novel, sensitive and rapid CL method was developed for the determination of hydrogen peroxide (H2O2). The corresponding linear regression equation was established in the range of 0.05–10 μM for H2O2. The detection limit (S/N = 3) is 0.02 μM and the relative standard deviation (RSD) for nine repeated measurements of 1.0 μM H2O2was 2.9%. This proposed method has been successfully applied to detect H2O2in rainwater samples with good accuracy and precision. The novel methodology is expected to provide a general protocol for the determination of H2O2as well as for numerous other oxidase-based reactions giving H2O2as a product (e.g., glucose). [ABSTRACT FROM AUTHOR]

The flue gas generated from a coal-fired power plant contains CO2and SO2. The effect of SO2concentration (≤1000 ppm) on the reaction of CO2with Ca(OH)2was studied using a differential fixed-bed reactor under the low-temperature and humid conditions similar to those in the bag filters of a dry or semidry flue gas desulfurization (FGD) system. When both CO2and SO2were present, they reacted with Ca(OH)2simultaneously to form calcium carbonate and sulfite, but part of the carbonate formed reacted further with SO2to form sulfite. Ca(OH)2ceased to react due to the formation of an impervious product layer. The fraction of carbonate increased significantly with decreasing SO2concentration in the range below 500 ppm SO2, but the fraction of sulfite decreased little except in the range below 100 ppm SO2or at a relative humidity (RH) above 70%. Both fractions of carbonate and sulfite increased markedly with increasing relative humidity and slightly with increasing temperature, but they were little affected by the CO2concentration and the presence of O2. At SO2concentrations ≤100 ppm, conversions of Ca(OH)2to carbonate in the range comparable to or higher than the typical conversions of Ca(OH)2for SO2removal in a dry or semidry FGD process could be achieved. The results of this work are useful for evaluating the feasibility of using solid wastes containing CaO and/or Ca(OH)2to capture CO2from flue gas at low temperatures. [ABSTRACT FROM AUTHOR]

In this study, a new dimethacrylate monomer 5,5′-bis[4-(2′-hydroxy-3′-methacryloyloxy-propoxy)-phenyl]-hexahydro-4,7-methan-oindan (5,5′-BHMPHM) with molecular weight of 640 and large molecular volume was designed and synthesized. The structure of monomer 5,5′-BHMPHM was confirmed by FT-IR, 1H-NMR and elemental analysis. Degree of double bond conversion, volume shrinkage, contact angle, water sorption and solubility, diffusion coefficient value, flexure strength and modulus of 5,5′-BHMPHM/tri(ethylene glycol) dimethacrylate (TEGDMA) based resin were measured. 2,2-bis[4-(2′-hydroxy-3′-methacryloyloxy-propoxy)-phenyl]-propane (Bis-GMA)/TEGDMA based resin was used as reference. The result illustrated that the double bond conversion, polymerization shrinkage, and diffusion coefficient value of 5,5′-BHMPHM/TEGDMA based resin were significantly lower than that of Bis-GMA/TEGDMA based resin ( P < 0.05). Water sorption, solubility, flexure strength and modulus of 5,5′-BHMPHM/TEGDMA based resin were higher than that of Bis-GMA/TEGDMA based resin ( P < 0.05). There was no statistical difference between 5,5′-BHMPHM/TEGDMA based resin and Bis-GMA/TEGDMA based resin in contact angle ( P > 0.05). [ABSTRACT FROM AUTHOR]

Growth factor-induced receptor dimerization and cross-phosphorylation are hallmarks of signal transduction via receptor tyrosine kinases (RTKs). G protein-coupled receptors (GPCRs) can activate RTKs through a process known as transactivation. The prototypical model of RTK transactivation involves ligand-mediated RTK dimerization and cross-phosphorylation. Here, we show that the platelet-derived growth factor receptor β (PDGFRβ) transactivation by the dopamine receptor D4 (DRD4) is not dependent on ligands for PDGFRβ. Furthermore, when PDGFRβ dimerization is inhibited and receptor phosphorylation is suppressed to near basal levels, the receptor maintains its ability to be transactivated and is still effective in signaling to ERK1/2. Hence, the DRD4-PDGFRβ-ERK1/2 pathway can occur independently of a PDGF-like ligand, PDGFRβ cross-phosphorylation and dimerization, which is distinct from other known forms of transactivation of RTKs by GPCRs. [ABSTRACT FROM AUTHOR]

The effects of the presence of CO2, O2, and NOx in the flue gas on the kinetics of the sulfation of blast furnace slag/hydrated lime sorbents at low temperatures were studied using a differential fixed-bed reactor. When O2 and NOx were not present simultaneously, the reaction kinetics was about the same as that under the gas mixtures containing SO2, H2O, and N2 only, being affected mainly by the relative humidity. The sulfation of sorbents can be described by the surface coverage model and the model equations derived for the latter case. When both O2 and NOx were present, the sulfation of sorbents was greatly enhanced, forming a great amount of sulfate in addition to sulfite. The surface coverage model is still valid in this case, but the model equations obtained show a more marked effect of relative humidity and negligible effects of SO2 concentration and temperature on the reaction. The effect of sorbent composition on the reaction kinetics was entirely represented by the effects of the initial specific surface area (Sg0) and the Ca molar content (M−1) of sorbent. The initial conversion rate of sorbent increased linearly with increasing Sg0, and the ultimate conversion increased linearly with increasing Sg0M−1. The model equations obtained in this work are applicable to describe the kinetics of the sulfation of the sorbents in the low-temperature dry and semidry flue gas desulfurization processes either with an upstream NOx removal unit or without. [ABSTRACT FROM AUTHOR]

Toxic polychiorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) with chiorines substituted at the lateral 2, 3, 7, and 8 positions are of great environmental concern. We investigated the dechlorination of 1 ,2,3,4,7,8-hexachlorodibenzofuran (1,2,3,4,7,8- HxCDF) and 1 ,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin (OCDD) by a mixed culture containing Dehalococcoides ethenogenes strain 195. The 1,2,3,4,7,8-HxCDF was dechlorinated to 1,3,4,7,8- pentachlorodibenzofuran and 1 ,2,4,7,8-pentachlorodibenzofuran and further to two tetrachlorodibenzofuran congeners, which were identified as 1,3,7,8-tetrachlorodibenzofuran and 1,2,4,8- tetrachlorodibenzofuran. Because no 2,3,7,8-substituted congeners were formed as dechlorination products from 1,2,3,4,7,8- HxCDF, this dechlorination represents a detoxification reaction. Tetrachloroethene (PCE) and 1 ,2,3,4-tetrachlorobenzene (1,2,3,4- TeCB) were added as additional halogenated substrates to enhance the degree of 1 ,2,3,4,7,8-HxCDF dechlorination. The 1,2,3,4- TeCB enhanced the extent of dechlorination of 1,2,3,4,7,8- HxCDF approximately 3-fold compared to PCE or no additional substrate amendment No dechlorination products were detected from OCDD. Bioremediation of PCDD/Fs by bacterial reductive dechlorination should address the pathway of dechlorination to ensure detoxification. [ABSTRACT FROM AUTHOR]

To reveal the effects of cadmium exposure on the endoplasmic reticulum (ER) stress response, we examined the expression and function of 78-kDa glucose-regulated protein (Grp78), an ER-resident molecular chaperone, in LLC-PK1 cells. In cells treated with 10 μM cadmium chloride, Grp78 protein levels increased after 6 hr and remained elevated at 24 hr. When cells were incubated with 1-20 μM CdCl2 for 6 hr, Grp78 increased in a dose-dependent manner. In addition, Grp78 mRNA levels were elevated in response to CdCl2 exposure. After exposure to 10 μM CdCl2, the levels of activating transcription factor 4 (ATF4) were increased at 2 hr, with a further enhancement after that; this accumulation followed the transient but marked phosphorylation of the a subunit of eukaryotic translation initiation factor 2 (eIF2α) on serine 51. Although ATF4 mRNA levels increased mildly by CdCl2 exposure, treatment with actinomycin D did not suppress CdCl2-induced accumulation of ATF4 protein, suggesting the involvement of posttranscriptional and, in part, transcriptional mechanisms. Compared with other heavy-metal compounds such as manganese chloride, zinc chloride, mercuric chloride, and lead chloride, CdCl2 could increase the levels of Grp78, ATF4, and the phosphorylated form of eIF2α more markedly without definite cellular damage. The silencing of Grp78 expression using short-interference RNA enhanced CdCl2-induced cellular damage. These results show that cadmium induces the expression of Grp78 probably via phosphorylation of eIF2α and resultant translation of ATF4, and this ER stress response plays a role in protection against cadmium cytotoxicity in this renal epithelial cell. [ABSTRACT FROM AUTHOR]

A 1-D chain-like hybrid coordination polymer [(CuBr)2(bpy)]n(bpy = 2,2′-bipyridine) was first synthesized viaa hydrothermal reaction of copper(I) bromide with 2,2′-bipyridine (bpy). The most fascinating feature of [(CuBr)2(bpy)]nis the unusual six-member-(Cu3Br3)-ring motif. The skeleton of copper bromide combined with bpy in [(CuBr)2(bpy)]nhas not been reported. In addition, research on pyrolysis of [(CuBr)2(bpy)]nwas reported in this paper. Oriented growth of single crystalline Cu(111) flake, which is usually prepared through depositing onto the surface of high-quality metal films (substrates), was synthesized by simply pyrolyzing [(CuBr)2(bpy)]nby adjusting the heating procedures. No capping reagent was induced to simplify the system. Since most of the research of pyrolysis of coordination polymers focuses on the relationship between the structure of precursor and sinter, the results of this paper show how the reaction conditions affect the morphology of the product and give a simple method for the synthesis of a Cu(111) flake, which has wide application in industry. [ABSTRACT FROM AUTHOR]

The China Fusion Engineering Test Reactor (CFETR) is a new tokamak device, whose magnet system includes toroidal field (TF), central solenoid (CS) and poloidal field (PF) coils. The main goal is to build a fusion engineering tokamak reactor with 50–200 MW fusion power and self-sufficiency by blanket, which means that the deuterium–tritium reaction in the plasma produces neutrons and alpha particles, and the neutrons react with the lithium-containing blanket surrounding the plasma, breeding the tritium by lithium–neutron reaction. To develop the manufacturing technique for the full-size CS coil, the Central Solenoid Model Coil (CSMC) project for CFETR was launched first. A Nb3Sn conductor is to be used in the CFETR CSMC, whose design refers to the ITER CS conductor with the same short-twist-pitch cable pattern. Due to the short twist pitch and relatively low void fraction, a high compaction ratio is required during cabling and the risk of strand damage is increased significantly. Although it is impossible to avoid strand deformation for this design, it is crucial to find a way to reduce strand damage as much as possible. A numerical model was used to analyze the causes of strand damage, including variation in twist pitch length as well as different mechanical properties for copper and Nb3Sn strands. Several experiments have been performed to verify the numerical results, including cabling trials for different conditions and critical current (Ic) tests on strands with/without deformation. The results show that the numerical analysis is consistent with the experiments and provides the optimal cabling conditions for the CFETR CSMC. [ABSTRACT FROM AUTHOR]

To enhance the interfacial interaction between rubber and hybrid nanofiller (HS) consisting of halloysite nanotubes and silica, and simultaneously prevent migration and volatilization of rubber additives, commercial vulcanization accelerator N-cyclohexyl-2-benzothiazole sulfenamide (CZ) was chemically grafted onto HS to obtain a functionalized nanofiller (HS-s-CZ). It was found that the grafted CZ molecules within an inorganic host structure have better efficiency to accelerate cross-linking reaction than free CZ molecules. In addition, HS-s-CZ could be evenly dispersed into styrene butadiene rubber (SBR) with further improved filler-rubber interaction compared with that between HS and SBR. Consequently, SBR/HS-s-CZ composites exhibited greater mechanical strength than SBR/HS composites containing equivalent accelerator component, showing 45% increase in tensile strength when the filler content was 40 phr. Potentially, this work offers a new design strategy for the surface modification of nanofiller and preparation of high-efficiency rubber additives, which may represent a new path for preparing high-performance elastomer composites. [ABSTRACT FROM AUTHOR]

Smad3, a major intracellular mediator of TGFβ signaling, functions as both a positive and negative regulator in carcinogenesis. In response to TGFβ, the TGFβ receptor phosphorylates serine residues at the Smad3 C-tail. Cancer cells often contain high levels of the MAPK and CDK activities, which can lead to the Smad3 linker region becoming highly phosphorylated. Here, we report, for the first time, that mutation of the Smad3 linker phosphorylation sites markedly inhibited primary tumor growth, but significantly increased lung metastasis of breast cancer cell lines. In contrast, mutation of the Smad3 C-tail phosphorylation sites had the opposite effect. We show that mutation of the Smad3 linker phosphorylation sites greatly intensifies all TGFβ-induced responses, including growth arrest, apoptosis, reduction in the size of putative cancer stem cell population, epithelial--mesenchymal transition, and invasive activity. Moreover, all TGFβ responses were completely lost on mutation of the Smad3 C-tail phosphorylation sites. Our results demonstrate a critical role of the counterbalance between the Smad3 C-tail and linker phosphorylation in tumorigenesis and metastasis. Our findings have important implications for therapeutic intervention of breast cancer. [ABSTRACT FROM AUTHOR]

Transforming growth factor-β (TGF-β) controls a diverse set of cellular processes, and its canonical signaling is mediated via TGF-β-induced phosphorylation of receptor-activated Smads (2 and 3) at the C-terminal SXS motif. We recently discovered that PPM1A can dephosphorylate Smad2/3 at the C-terminal SXS motif, implicating a critical role for phosphatases in regulating TGF-β signaling. Smad2/3 activity is also regulated by phosphorylation in the linker region (and N terminus) by a variety of intracellular kinases, making it a critical platform for cross-talk between TGF-β and other signaling pathways. Using a functional genomic approach, we identified the small C-terminal domain phosphatase 1 (SCP1) as a specific phosphatase for Smad2/3 dephosphorylation in the linker and N terminus. A catalytically inactive SCP1 mutant (dnSCP1) had no effect on Smad2/3 phosphorylation in vitro or in vivo. Of the other FCP/ SCP family members SCP2 and SCP3, but not FCP1, could also dephosphorylate Smad2/3 in the linker/N terminus. Depletion of SCP1/2/3 enhanced Smad2/3 linker phosphorylation. SCP1 increased TGF-β-induced transcriptional activity in agreement with the idea that phosphorylation in the Smad2/3 linker must be removed for a full transcriptional response. SCP1 overexpression also counteracts the inhibitory effect of epidermal growth factor on TGF-β-induced p15 expression. Taken together, this work identifies the first example of a Smad2/3 linker phosphatase(s) and reveals an important new substrate for SCPs. [ABSTRACT FROM AUTHOR]

Smad3 is phosphorylated by ERK MAP kinase upon EGF treatment. We have mapped the ERK phosphorylation sites to Ser 207, Ser 203, and Thr 178 in Smad3. We show that, upon EGF treatment, Smad3 is rapidly phosphorylated in these sites, peaking at ∼15-30 min and that MEK1 inhibitors PD98059 and U0216 inhibit Smad3 phosphorylation induced by EGF. Ser 207 is the best ERK site in Smad3. Its phosphorylation shows the highest EGF induction in Smad3. It is also a very sensitive site to EGF treatment, significantly responding to low concentrations of EGF. These three sites are also phosphorylated by recombinant ERK2 in vitro. We have compared the kinetic parameters of Smad3 with those of ELK1 and MBP for ERK2. We further show that mutation of the ERK phosphorylation sites increases the ability of Smad3 to stimulate a Smad target gene, suggesting that ERK phosphorylation inhibits Smad3 activity. [ABSTRACT FROM AUTHOR]