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1.
Zool Stud ; 61: e55, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36568812

RESUMO

A new species of the genus Rapisma, Rapisma taiwanense sp. nov., is described from Taiwan. The new species represents the first of its genus and family recorded in Taiwan. By collecting both genders, the hypothesis of sexual dimorphism is examined. This finding also expands the easternmost distribution border of Rapisma in the Oriental region. This discovery can be attributed to the development of social media which helps researchers access rare species.

2.
Microsc Res Tech ; 85(7): 2390-2396, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35234327

RESUMO

In this study, silver-doped nickel oxide (NiO:Ag) was successfully synthesized by a sol-gel method and spin-coated on indium titanium oxide (ITO) as a hole-transport layer for polymer light-emitting diodes (PLED). After the calcination of the NiO:Ag/ITO substrate at 300°C for 1 h, stable conductive regions and the mean work-function on the NiO:Ag/ITO surface reached 89.43% and 5.53 eV, respectively, which were greater than those on a conventional poly [3,4-ethylenedioxythiophene] polystyrene sulfonate (PEDOT:PSS)/ITO surface. When NiO:Ag (300°C)/ITO was used as an anode window substrate for PLEDs, the enhancement factor for the average current efficiency in the current-density range of 20-50 mA/cm2 and electroluminescence intensity at an applied bias of 8.0 V were 4.60 and 2.55 times, respectively, in comparison with those of PLED based on a conventional PEDOT:PSS/ITO anode. HIGHLIGHTS: NiO:Ag is synthesized by a sol-gel method and spin-coated on ITO as a HTL for PLED. NiO:Ag/ITO calcined at 300°C for 1 h has the best microscopic electrical properties. The performance for proposed PLED is much better than that for typical PLED.

3.
ACS Appl Mater Interfaces ; 10(35): 29273-29287, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-30133249

RESUMO

Three-dimensional bioprinting serves as an attractive platform to fabricate customized tissue-engineered substitutes from biomaterials and cells for the repair or replacement of injured tissues and organs. A common challenge for 3D bioprinting materials is that the structures printed from the biodegradable polymer hydrogels tend to collapse because of the poor mechanical stability. In this study, dual stimuli-responsive biodegradable polyurethane (PU) dispersions (PUA2 and PUA3) were synthesized from an eco-friendly waterborne process. Acrylate group was introduced in the PU chain end to serve as a photosensitive moiety for UV-induced cross-linking and improvement of the printability, while mixed oligodiols in the soft segment remained to be the thermosensitive moiety. The photo/thermal-induced morphological changes of PU nanoparticles were verified by dynamic light scattering, small-angle X-ray scattering, and rheological measurement of the dispersions. It was observed that these PU nanoparticles became more rod-like in shape after UV treatment and formed compact packing structures upon further heating. With the thermosensitive properties, these UV-cured PU dispersions underwent rapid thermal gelation with gel moduli in the range 0.5-2 kPa near body temperature. The rheological properties of the PU hydrogels including dynamic viscoelasticity, creep recovery, and shear thinning behavior at 37 °C were favorable for processing by microextrusion-based 3D printing and could be easily mixed with cells before printing to produce cell-laden constructs. The dual-responsive hydrogel constructs demonstrated higher resolution and shape fidelity as well as better cell viability and proliferation than the thermoresponsive control. Moreover, the softer hydrogel (PUA3) with a low modulus (<1 kPa) could offer neural stem cells a tofu-like, stable, and inductive 3D microenvironment to proliferate and differentiate. We expect that the photo/thermoresponsive biodegradable polyurethane ink may offer unique rheological properties to contribute toward the custom-made bioprinting of soft tissues.


Assuntos
Bioimpressão/métodos , Hidrogéis/química , Poliuretanos/química , Impressão Tridimensional , Engenharia Tecidual
4.
Biomed Microdevices ; 13(3): 517-26, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21347824

RESUMO

We design a microfluidic patterned co-culture system for mouse mesenchymal stem cells (mMSCs) and neural cells to demonstrate the paracrine effects produced by the neural cells in facilitating the transdifferentiation from mMSCs to neuron-like cells. Neural cells and mMSC are orderly patterned in the microfluidic co-culturing system without direct cell contact. This configuration provides us to calculate the percentage of neural marker transdifferentiated by mMSCs easily. We obtain higher transdifferentiated ratio of mMSC in the microfluidic co-culturing system (beta III tubulin: 67%; glial fibrillary acidic protein (GFAP): 86.2%) as compared with the traditional transwell co-culturing system (beta III tubulin: 59.8%; GFAP: 52.0%), which is similar to the spontaneous neural marker expression in the undifferentiated MSCs (beta III tubulin: 47.5%; GFAP: 60.1%). Furthermore, mMSCs expressing green fluorescent protein and neural cells expressing red fluorescent protein were also used in our co-culture system to demonstrate the rarely occurring or observed cell fusion phenomenon. The results show that the co-cultured neural cells increased the transdifferentiation efficiency of mMSCs from soluble factors secreted by neural cells.


Assuntos
Transdiferenciação Celular , Técnicas de Cocultura/instrumentação , Células-Tronco Mesenquimais/citologia , Técnicas Analíticas Microfluídicas/instrumentação , Neurônios/citologia , Animais , Biomarcadores/metabolismo , Comunicação Celular , Fusão Celular , Regulação da Expressão Gênica , Camundongos , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo
5.
Biomaterials ; 30(29): 5523-33, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19646749

RESUMO

An ex vivo degenerative intervertebral disc (IVD) organ culture system was established for the screening of disc regeneration agents. Its application was demonstrated by a stem cell and growth factor-based therapeutic approach for the amelioration of IVD. An ex vivo culture system using chymopapain to partially digest nucleus proposus tissue was established to mimic human IVD degeneration. This system was then used for the evaluation of different therapeutic regimens including: mesenchymal stem cell derived from eGFP-transgenic porcine (MSC-GFP), platelet-rich plasma (PRP) and MSC-GFP/PRP combined treatment, and confirmed in in vivo animal model. Chondrogenic-specific gene products including Col II and aggrecan were found upregulated and chondrogenic matrix deposition increased, as evident by sustained fluorescent signals over 4 weeks, in the MSC-GFP implanted group. Previously, we demonstrated in vitro stage-specific chondrogenesis of MSC by chondrocytic commitment. These same molecules upregulated for chondrogenesis were also observed in MSC-GFP group. PRP that has been shown to promote nucleus pulposus (NP) regeneration also resulted in significant increased levels of mRNA involved in chondrogenesis and matrices accumulation. The ex vivo IVD regeneration results were repeated and supported by in vivo porcine degenerative system. Moreover, the disc height index (DHI) was significantly increased in both in vivo MSC-GFP and PRP regeneration groups. Unexpectedly, the MSC-GFP/PRP combined therapy demonstrated an inclination towards osteogenesis in ex vivo system. The ex vivo degenerative IVD culture system described in this study could serve as an alternative and more accessible model over large animal model. This system also provides a high-throughput platform for screening therapeutic agents for IVD regeneration.


Assuntos
Técnicas de Cultura de Células/métodos , Condrogênese/fisiologia , Deslocamento do Disco Intervertebral/patologia , Deslocamento do Disco Intervertebral/cirurgia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Técnicas de Cultura de Órgãos/métodos , Regeneração/fisiologia , Animais , Células Cultivadas , Células-Tronco Mesenquimais/fisiologia , Suínos
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