Browsing by Author "Chiang, Yi-Ting"

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Dependence of the structure and orientation of VSS grown Si nanowires on an epitaxy process
(2019-08-07)
Chiang, Yi-Ting
;
Chou, Yi
;
Huang, Chang-Hsun
;
Lin, Wei-Ting
;
Chou, Yi-Chia
We investigated the vapor-solid-solid growth of Si nanowires from Ni silicides on Si(111), Si(110), and GaN substrates. The morphology and structures of Si on these substrates are distinct, and are dependent on substrate lattices and an epitaxy process during growth. The sidewall facets and epitaxy of silicides and Si were discussed. In addition, Si grown on GaN nanowires was investigated which led to the formation of branched nanowire structures. The Si nanowires/nanodots lie on the surface of GaN nanowires to maintain lower system energy. We manipulated the whole process in a UHV and studied the crystal growth of Si on different lattice substrates. Meanwhile, the process which occurred in a non-UHV led to less regularity on the NiSi2 crystal facets and interface epitaxy between NiSi2 and Si nanowires.
Stepped changes of monovalent ligand-binding force during ligand-induced clustering of integrin alpha(IIB)beta(3)
(2006-09-01)
Hsieh, Chia-Fen
;
Chang, Bo-Jui
;
Pai, Chyi-Huey
;
Chen, Hsuan-Yi
;
Tsai, Jin-Wu
Recent evidence demonstrated that conformational changes of the integrin during receptor activation affected its binding to extracellular matrix; however, experimental assessment of ligand-receptor binding following the initial molecular interaction has rarely been carried out at a single-molecule resolution. In the present study, laser tweezers were used to measure the binding force exerted by a live Chinese hamster ovary cell that expressed integrin alpha(IIb)beta(3) (CHO alpha(IIb)beta(3)), to the bead carrier coated with the snake venom rhodostomin that served as an activated ligand for integrin alpha(IIb)beta(3). A progressive increase of total binding force over time was noticed when the bead interacted with the CHO alpha(IIb)beta(3) cell; such an increase was due mainly to the recruitment of more integrin molecules to the bead-cell interface. When the binding strength exerted by a single ligand-receptor pair was derived from the "polyvalent" measurements, surprisingly, a stepped decrease of the "monovalent binding force" was noted (from 4.15 to 2.54 piconewtons (pN)); such decrease appeared to occur during the ligand-induced integrin clustering process. On the other hand, the mutant rhodostomin defective in clustering integrins exhibited only one (1.81 pN) unit binding strength.