yuwen zhao - Academia.edu (original) (raw)

Papers by yuwen zhao

Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997

ABSTRACT Polycrystalline silicon (poly-Si) films (10-20 μm) were grown from SiH2Cl2 or SiCl4 by a... more ABSTRACT Polycrystalline silicon (poly-Si) films (10-20 μm) were grown from SiH2Cl2 or SiCl4 by a rapid thermal chemical vapor deposition (RTCVD) technique, with a growth rate up to 100 A/s at the substrate temperature (Ts) of above 1030°C. The average grain size and carrier mobility of the films were found to be dependent on Ts and the substrate materials. By using the poly-Si film, the solar cells have been prepared on the heavily phosphorus-doped Si wafer, and the energy conversion efficiency of the best cell is 9.88% (AM 1.5G, 100 mW/cm2, 25°C)

Solar Energy Materials and Solar Cells, 1997

Polycrystalline silicon (poly-Si) films (∼ 10 μm) were grown from dichlorosilane by a rapid therm... more Polycrystalline silicon (poly-Si) films (∼ 10 μm) were grown from dichlorosilane by a rapid thermal chemical vapor deposition (RTCVD) technique, with a growth rate up to 100 Å/s at the substrate temperature (Ts) of 1030°C. The average grain size and carrier mobility of the films were found to be dependent on the substrate temperature and material. By using the poly-Si

Solar Energy Materials and Solar Cells, 2000

An improved pulsed rapid thermal annealing (PRTA) has been used for the solid-phase crystallizati... more An improved pulsed rapid thermal annealing (PRTA) has been used for the solid-phase crystallization (SPC) of a-Si "lms prepared by PECVD. The SPC can be completed with time-temperature budgets such as 10 cycles of 60-s 5503C thermal bias/1-s 8503C thermal pulse. The microstructure and surface morphology of the crystallized "lms are investigated by X-ray di!raction (XRD). The results indicate that this PRTA is a suitable post-crystallization technique for fabricating large-area poly-Si "lms on low-cost substrate. 2000 Elsevier Science B.V. All rights reserved.

Solar Energy Materials and Solar Cells, 1997

This paper investigates the effects of the diphasic structure on the optoelectronic properties of... more This paper investigates the effects of the diphasic structure on the optoelectronic properties of hydrogenated microcrystalline silicon (μc-Si : H) films prepared in a triode three-chamber plasma-enhanced chemical vapor deposition (PECVD) system. The influences of boron-compensation doping on the dark- and photo-conductivity of μc-Si : H films are also described. A tandem solar cell with an entirely μc-Si : H p-i-n bottom cell and an a-Si : H top cell has been prepared with an initial conversion efficiency of 8.91% (0.126 cm2, AM 1.5, 100 mW/cm2).

Human mesenchymal stem cells (hMSCs) have great potential in cell-based therapies for tissue engi... more Human mesenchymal stem cells (hMSCs) have great potential in cell-based therapies for tissue engineering and regenerative medicine due to their self-renewal and multipotent properties. Recent studies indicate that Notch1-Dll4 signaling is an important pathway in regulating osteogenic differentiation of hMSCs. However, the fundamental mechanisms that govern osteogenic differentiation are poorly understood due to a lack of effective tools to detect gene expression at single cell level. Here, we established a double-stranded locked nucleic acid (LNA)/DNA (LNA/DNA) nanobiosensor for gene expression analysis in single hMSC in both 2D and 3D microenvironments. We first characterized this LNA/DNA nanobiosensor and demonstrated the Dll4 mRNA expression dynamics in hMSCs during osteogenic differentiation. By incorporating this nanobiosensor with live hMSCs imaging during osteogenic induction, we performed dynamic tracking of hMSCs differentiation and Dll4 mRNA gene expression profiles of ind...

2020 IEEE 15th International Conference on Nano/Micro Engineered and Molecular System (NEMS), 2020

We investigated the effects of intracellular uptake of different sizes of gold nanoparticles (GNP... more We investigated the effects of intracellular uptake of different sizes of gold nanoparticles (GNP) ranging from 10 nm to 100 nm on breast cancer cells (MDA-MB-231). The experimental results showed the cell cytotoxicity is high doseand dimension-dependent. We further investigated the effect of intracellular uptake of GNP on cell morphology, including cell area, perimeter, and aspect ratio. We showed GNP with a diameter of 20 nm enhanced cell proliferation with a low concentration of GNP (2 μg/mL, 4 μg/mL, and 10 μg/mL). To evaluate the specific sizes of GNP affection in wound healing, we investigated the cell migration ability after GNP uptake. Also, we detect the Dll4 expression when the GNP works as a probe, in which the 10 nm GNP-LNA complex reveals significant signal intensity.

2021 IEEE 21st International Conference on Nanotechnology (NANO), 2021

Human mesenchymal stem cells (hMSCs) have great potential for tissue engineering and regenerative... more Human mesenchymal stem cells (hMSCs) have great potential for tissue engineering and regenerative medicine due to their self-renewal and multi-differentiation properties. However, the cellular and molecular mechanisms that govern osteogenic differentiation are poorly understood due to a lack of effective tools to detect gene expression at single cell level. Here, we present a double-stranded locked nucleic acid biosensor to investigate gene expression analysis during hMSCs osteogenic differentiation. We first demonstrated this biosensor for gene expression analysis in single hMSCs. We next investigated the regulatory role of Notch1-Dll4 signaling in osteogenic differentiation. Our findings provide evidence that Notch1-Dll4 signaling is involved in hMSCs osteogenic differentiation. Inhibition of Notch1-Dll4 signaling significantly decreased osteogenic differentiation and Dll4 expression.

Journal of Functional Biomaterials, 2021

Biopolymers are widely accepted natural materials in regenerative medicine, and further developme... more Biopolymers are widely accepted natural materials in regenerative medicine, and further development of their bioactivities and discoveries on their composition/function relationships could greatly advance the field. However, a concise insight on commonly investigated biopolymers, their current applications and outlook of their modifications for multibioactivity are scarce. This review bridges this gap for professionals and especially freshmen in the field who are also interested in modification methods not yet in commercial use. A series of polymeric materials in research and development uses are presented as well as challenges that limit their efficacy in tissue regeneration are discussed. Finally, their roles in the regeneration of select tissues including the skin, bone, cartilage, and tendon are highlighted along with modifiable biopolymer moieties for different bioactivities.

2021 IEEE 15th International Conference on Nano/Molecular Medicine & Engineering (NANOMED)

Osteoporosis is a common bone and metabolic disease that is characterized by bone density loss an... more Osteoporosis is a common bone and metabolic disease that is characterized by bone density loss and microstructural degeneration. Human bone marrow-derived mesenchymal stem cells have great potential for bone tissue engineering and cell-based therapy due to their excellent multipotency, especially osteogenic differentiation. Although low fluid shear force plays an important role in bone osteogenic differentiation, the cellular and molecular mechanisms underlying this effect remain poorly understood due to a lack of effective tools to detect gene expression at the single-cell level. Here, we presented a double-stranded nucleic acid biosensor to examine the regulatory role of Notch signaling during osteogenic differentiation. The effects of orbital shear stress on hMSC proliferation, morphology change, osteogenic differentiation and Notch1-Dll4 signaling were examined. Osteogenic differentiation was studied by characterizing alkaline phosphatase (ALP) activity. We further investigated how orbital shear modulates Notch1-Dll4 signaling during osteogenic differentiation. Our results showed Notch1-Dll4 signaling is involved in orbital shearregulated osteogenic differentiation. Inhibition of Notch signaling will mediate the effects of shear stress on human osteogenic differentiation.

Cell-free expression (CFE) systems have been used extensively in system and synthetic biology as ... more Cell-free expression (CFE) systems have been used extensively in system and synthetic biology as a promising platform for manufacturing proteins and chemicals. Currently, the most widely used CFE system is in vitro protein transcription and translation platform. As the rapidly increased applications and uses, it is crucial to have a standard biophysical model for quantitative studies of gene circuits, which will provide a fundamental understanding of basic working mechanisms of CFE systems. Current modeling approaches mainly focus on the characterization of E. coli-based CFE systems, a computational model that can be utilized to both bacterial- and mammalianbased CFE has not been investigated. Here, we developed a simple ODE (ordinary differential equation)-based biophysical model to simulate transcription and translation dynamics for both bacterial- and mammalian-based CFE systems. The key parameters were estimated and adjusted based on experimental results. We next tested four gen...

Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997

ABSTRACT Polycrystalline silicon (poly-Si) films (10-20 μm) were grown from SiH2Cl2 or SiCl4 by a... more ABSTRACT Polycrystalline silicon (poly-Si) films (10-20 μm) were grown from SiH2Cl2 or SiCl4 by a rapid thermal chemical vapor deposition (RTCVD) technique, with a growth rate up to 100 A/s at the substrate temperature (Ts) of above 1030°C. The average grain size and carrier mobility of the films were found to be dependent on Ts and the substrate materials. By using the poly-Si film, the solar cells have been prepared on the heavily phosphorus-doped Si wafer, and the energy conversion efficiency of the best cell is 9.88% (AM 1.5G, 100 mW/cm2, 25°C)

Solar Energy Materials and Solar Cells, 1997

Polycrystalline silicon (poly-Si) films (∼ 10 μm) were grown from dichlorosilane by a rapid therm... more Polycrystalline silicon (poly-Si) films (∼ 10 μm) were grown from dichlorosilane by a rapid thermal chemical vapor deposition (RTCVD) technique, with a growth rate up to 100 Å/s at the substrate temperature (Ts) of 1030°C. The average grain size and carrier mobility of the films were found to be dependent on the substrate temperature and material. By using the poly-Si

Solar Energy Materials and Solar Cells, 2000

An improved pulsed rapid thermal annealing (PRTA) has been used for the solid-phase crystallizati... more An improved pulsed rapid thermal annealing (PRTA) has been used for the solid-phase crystallization (SPC) of a-Si "lms prepared by PECVD. The SPC can be completed with time-temperature budgets such as 10 cycles of 60-s 5503C thermal bias/1-s 8503C thermal pulse. The microstructure and surface morphology of the crystallized "lms are investigated by X-ray di!raction (XRD). The results indicate that this PRTA is a suitable post-crystallization technique for fabricating large-area poly-Si "lms on low-cost substrate. 2000 Elsevier Science B.V. All rights reserved.

Solar Energy Materials and Solar Cells, 1997

This paper investigates the effects of the diphasic structure on the optoelectronic properties of... more This paper investigates the effects of the diphasic structure on the optoelectronic properties of hydrogenated microcrystalline silicon (μc-Si : H) films prepared in a triode three-chamber plasma-enhanced chemical vapor deposition (PECVD) system. The influences of boron-compensation doping on the dark- and photo-conductivity of μc-Si : H films are also described. A tandem solar cell with an entirely μc-Si : H p-i-n bottom cell and an a-Si : H top cell has been prepared with an initial conversion efficiency of 8.91% (0.126 cm2, AM 1.5, 100 mW/cm2).

Human mesenchymal stem cells (hMSCs) have great potential in cell-based therapies for tissue engi... more Human mesenchymal stem cells (hMSCs) have great potential in cell-based therapies for tissue engineering and regenerative medicine due to their self-renewal and multipotent properties. Recent studies indicate that Notch1-Dll4 signaling is an important pathway in regulating osteogenic differentiation of hMSCs. However, the fundamental mechanisms that govern osteogenic differentiation are poorly understood due to a lack of effective tools to detect gene expression at single cell level. Here, we established a double-stranded locked nucleic acid (LNA)/DNA (LNA/DNA) nanobiosensor for gene expression analysis in single hMSC in both 2D and 3D microenvironments. We first characterized this LNA/DNA nanobiosensor and demonstrated the Dll4 mRNA expression dynamics in hMSCs during osteogenic differentiation. By incorporating this nanobiosensor with live hMSCs imaging during osteogenic induction, we performed dynamic tracking of hMSCs differentiation and Dll4 mRNA gene expression profiles of ind...

2020 IEEE 15th International Conference on Nano/Micro Engineered and Molecular System (NEMS), 2020

We investigated the effects of intracellular uptake of different sizes of gold nanoparticles (GNP... more We investigated the effects of intracellular uptake of different sizes of gold nanoparticles (GNP) ranging from 10 nm to 100 nm on breast cancer cells (MDA-MB-231). The experimental results showed the cell cytotoxicity is high doseand dimension-dependent. We further investigated the effect of intracellular uptake of GNP on cell morphology, including cell area, perimeter, and aspect ratio. We showed GNP with a diameter of 20 nm enhanced cell proliferation with a low concentration of GNP (2 μg/mL, 4 μg/mL, and 10 μg/mL). To evaluate the specific sizes of GNP affection in wound healing, we investigated the cell migration ability after GNP uptake. Also, we detect the Dll4 expression when the GNP works as a probe, in which the 10 nm GNP-LNA complex reveals significant signal intensity.

2021 IEEE 21st International Conference on Nanotechnology (NANO), 2021

Human mesenchymal stem cells (hMSCs) have great potential for tissue engineering and regenerative... more Human mesenchymal stem cells (hMSCs) have great potential for tissue engineering and regenerative medicine due to their self-renewal and multi-differentiation properties. However, the cellular and molecular mechanisms that govern osteogenic differentiation are poorly understood due to a lack of effective tools to detect gene expression at single cell level. Here, we present a double-stranded locked nucleic acid biosensor to investigate gene expression analysis during hMSCs osteogenic differentiation. We first demonstrated this biosensor for gene expression analysis in single hMSCs. We next investigated the regulatory role of Notch1-Dll4 signaling in osteogenic differentiation. Our findings provide evidence that Notch1-Dll4 signaling is involved in hMSCs osteogenic differentiation. Inhibition of Notch1-Dll4 signaling significantly decreased osteogenic differentiation and Dll4 expression.

Journal of Functional Biomaterials, 2021

Biopolymers are widely accepted natural materials in regenerative medicine, and further developme... more Biopolymers are widely accepted natural materials in regenerative medicine, and further development of their bioactivities and discoveries on their composition/function relationships could greatly advance the field. However, a concise insight on commonly investigated biopolymers, their current applications and outlook of their modifications for multibioactivity are scarce. This review bridges this gap for professionals and especially freshmen in the field who are also interested in modification methods not yet in commercial use. A series of polymeric materials in research and development uses are presented as well as challenges that limit their efficacy in tissue regeneration are discussed. Finally, their roles in the regeneration of select tissues including the skin, bone, cartilage, and tendon are highlighted along with modifiable biopolymer moieties for different bioactivities.

2021 IEEE 15th International Conference on Nano/Molecular Medicine & Engineering (NANOMED)

Osteoporosis is a common bone and metabolic disease that is characterized by bone density loss an... more Osteoporosis is a common bone and metabolic disease that is characterized by bone density loss and microstructural degeneration. Human bone marrow-derived mesenchymal stem cells have great potential for bone tissue engineering and cell-based therapy due to their excellent multipotency, especially osteogenic differentiation. Although low fluid shear force plays an important role in bone osteogenic differentiation, the cellular and molecular mechanisms underlying this effect remain poorly understood due to a lack of effective tools to detect gene expression at the single-cell level. Here, we presented a double-stranded nucleic acid biosensor to examine the regulatory role of Notch signaling during osteogenic differentiation. The effects of orbital shear stress on hMSC proliferation, morphology change, osteogenic differentiation and Notch1-Dll4 signaling were examined. Osteogenic differentiation was studied by characterizing alkaline phosphatase (ALP) activity. We further investigated how orbital shear modulates Notch1-Dll4 signaling during osteogenic differentiation. Our results showed Notch1-Dll4 signaling is involved in orbital shearregulated osteogenic differentiation. Inhibition of Notch signaling will mediate the effects of shear stress on human osteogenic differentiation.

Cell-free expression (CFE) systems have been used extensively in system and synthetic biology as ... more Cell-free expression (CFE) systems have been used extensively in system and synthetic biology as a promising platform for manufacturing proteins and chemicals. Currently, the most widely used CFE system is in vitro protein transcription and translation platform. As the rapidly increased applications and uses, it is crucial to have a standard biophysical model for quantitative studies of gene circuits, which will provide a fundamental understanding of basic working mechanisms of CFE systems. Current modeling approaches mainly focus on the characterization of E. coli-based CFE systems, a computational model that can be utilized to both bacterial- and mammalianbased CFE has not been investigated. Here, we developed a simple ODE (ordinary differential equation)-based biophysical model to simulate transcription and translation dynamics for both bacterial- and mammalian-based CFE systems. The key parameters were estimated and adjusted based on experimental results. We next tested four gen...