465 research outputs found

    Technology Capability and the Internationalization Strategies of New Ventures

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    This study investigates the impact of technological capability and the combination of technological capability, networking capability and financial capital on growth strategies adopted by new ventures in China. Technological capability needs leveraging through the process of combining with other capabilities. The results show that the interaction between technological capability and networking capability increases the possibility that a new venture chooses an internationalisation strategy. Technology capability provides a base to allow networks to have a positive impact on internationalisation strategies. The findings from the study provide a better understanding of technology capability and its impact on internationalisation strategies. This study also generates some important implications for high-tech new ventures in emerging economies

    Technology Capability and the Internationalization of New Ventures

    Get PDF
    This study investigates the impact of technological capability and the combination of technological capability, networking capability and financial capital on growth strategies adopted by new ventures in China. Technological capability needs leveraging through the process of combining with other capabilities. The results show that the interaction between technological capability and networking capability increases the possibility that a new venture chooses an internationalisation strategy. Technology capability provides a base to allow networks to have a positive impact on internationalisation strategies. The findings from the study provide a better understanding of technology capability and its impact on internationalisation strategies. This study also generates some important implications for high-tech new ventures in emerging economies

    Studies of chondroitin sulfate on palatal fibroblasts : Implication for wound healing

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    Ph.DDOCTOR OF PHILOSOPH

    CFTR Gating II: Effects of Nucleotide Binding on the Stability of Open States

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    Previously, we demonstrated that ADP inhibits cystic fibrosis transmembrane conductance regulator (CFTR) opening by competing with ATP for a binding site presumably in the COOH-terminal nucleotide binding domain (NBD2). We also found that the open time of the channel is shortened in the presence of ADP. To further study this effect of ADP on the open state, we have used two CFTR mutants (D1370N and E1371S); both have longer open times because of impaired ATP hydrolysis at NBD2. Single-channel kinetic analysis of ΔR/D1370N-CFTR shows unequivocally that the open time of this mutant channel is decreased by ADP. ΔR/E1371S-CFTR channels can be locked open by millimolar ATP with a time constant of ∼100 s, estimated from current relaxation upon nucleotide removal. ADP induces a shorter locked-open state, suggesting that binding of ADP at a second site decreases the locked-open time. To test the functional consequence of the occupancy of this second nucleotide binding site, we changed the [ATP] and performed similar relaxation analysis for E1371S-CFTR channels. Two locked-open time constants can be discerned and the relative distribution of each component is altered by changing [ATP] so that increasing [ATP] shifts the relative distribution to the longer locked-open state. Single-channel kinetic analysis for ΔR/E1371S-CFTR confirms an [ATP]-dependent shift of the distribution of two locked-open time constants. These results support the idea that occupancy of a second ATP binding site stabilizes the locked-open state. This binding site likely resides in the NH(2)-terminal nucleotide binding domain (NBD1) because introducing the K464A mutation, which decreases ATP binding affinity at NBD1, into E1371S-CFTR shortens the relaxation time constant. These results suggest that the binding energy of nucleotide at NBD1 contributes to the overall energetics of the open channel conformation

    Bulk dense fine-grain (1-x)BiScO\u3csub\u3e3\u3c/sub\u3e–xPbTiO\u3csub\u3e3\u3c/sub\u3e ceramics with high piezoelectric coefficient

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    High density fine grain (1−x)BiScO3–xPbTiO3 ceramics were successfully prepared by two-step sintering and their ferroelectric properties were investigated. Experimental evidence indicates the existence of a morphotropic phase boundary at the composition zx=0.635, which exhibits a piezoelectric coefficient d33 of 700 pC/N at room temperature, significantly higher than the reported values to date. Furthermore, a higher electromechanical coupling factor Kp=0.632 and a larger remnant polarization Pr=47.3 µC/cm2 were obtained. The paraelectric-to-ferroelectric phase transition occurs at 446 °C, slightly lower than in the coarse grain ceramics with a similar composition, suggesting a grain size effect. The local effective piezoelectric coefficient d33* was estimated to be 795 pC/N at 2.29 V, measured by scanning probe microscopy. Further atomic force microscope observation revealed the existence of 90° domains of about 60–70 nm in width, confirming the previous results that small domain structure enhances the piezoelectric properties

    One-step synthesis of AlN branched nanostructures by an improved DC arc discharge plasma method

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    Aluminium nitride (AlN) branched nanostructures with tree shapes and sea urchin shapes are synthesized via a one-step improved DC arc discharge plasma method without any catalyst and template. The branched nanostructures with tree shapes and sea urchin shapes can be easily controlled by the location of collection. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies show that the branches of tree shaped nanostructures grow in a sequence of nanowires, nanomultipeds and nanocombs. The growth mechanisms of these branched nanostructures are discussed in detail. The optical properties of AlN branched nanostructures with tree shapes and sea urchin shapes are investigated

    The Two ATP Binding Sites of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Play Distinct Roles in Gating Kinetics and Energetics

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    Cystic fibrosis transmembrane conductance regulator (CFTR), a member of the ABC (ATP binding cassette) transporter family, is a chloride channel whose activity is controlled by protein kinase–dependent phosphorylation. Opening and closing (gating) of the phosphorylated CFTR is coupled to ATP binding and hydrolysis at CFTR's two nucleotide binding domains (NBD1 and NBD2). Recent studies present evidence that the open channel conformation reflects a head-to-tail dimerization of CFTR's two NBDs as seen in the NBDs of other ABC transporters (Vergani et al., 2005). Whether these two ATP binding sites play an equivalent role in the dynamics of NBD dimerization, and thus in gating CFTR channels, remains unsettled. Based on the crystal structures of NBDs, sequence alignment, and homology modeling, we have identified two critical aromatic amino acids (W401 in NBD1 and Y1219 in NBD2) that coordinate the adenine ring of the bound ATP. Conversion of the W401 residue to glycine (W401G) has little effect on the sensitivity of the opening rate to [ATP], but the same mutation at the Y1219 residue dramatically lowers the apparent affinity for ATP by >50-fold, suggesting distinct roles of these two ATP binding sites in channel opening. The W401G mutation, however, shortens the open time constant. Energetic analysis of our data suggests that the free energy of ATP binding at NBD1, but not at NBD2, contributes significantly to the energetics of the open state. This kinetic and energetic asymmetry of CFTR's two NBDs suggests an asymmetric motion of the NBDs during channel gating. Opening of the channel is initiated by ATP binding at the NBD2 site, whereas separation of the NBD dimer at the NBD1 site constitutes the rate-limiting step in channel closing
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