We demonstrate that human multipotent MSCs are present in second-trimester amniotic fluid. Considering the great potential of cellular therapy using fetal stem cells and the feasibility of intrauterine fetal tissue engineering, amniotic fluid may provide an excellent alternative source for investigation of human MSCs.

Inkjet printing of inorganic materials for the formation of active devices is relatively rare compared to the research done with respect to organic materials. To date, only a handful of inorganic materials have been ink-jet printed, primarily because of the difficulty in preparing ink-jet-printable precursors. We have developed a general and low-cost route to the ink-jet printing of transparent amorphous oxide semiconductors. Our process uses metal halide precursors dissolved in acetonitrile, an organic solvent. This precursor solution is capable of forming a uniform and continuous metal halide thin film over a large area through both ink-jet printing and blanket-coating techniques. The printed metal halide thin films are converted to semiconducting metal oxides by thermally annealing the metal halides in the air. In this paper, we report thin-film transistors (TFTs) that were fabricated using this technique with field-effect mobilities as high as 7.4 cm 2 V -1 s -1 and 16.1 cm 2 V -1 s -1

Recent evidence has shown that amniotic fluid may be a novel source of fetal stem cells for therapeutic transplantation. We previously developed a two-stage culture protocol to isolate a population of amniotic fluid-derived mesenchymal stem cells (AFMSCs) from second-trimester amniocentesis. AFMSCs maintain the capacity to differentiate into multiple mesenchymal lineages and neuron-like cells. It is unclear whether amniotic fluid contains heterogeneous populations of stem cells or a subpopulation of primitive stem cells that are similar to marrow stromal cells showing the behavior of neural progenitors. In this study, we showed a subpopulation of amniotic fluid-derived stem cells (AF-SCs) at the single-cell level by limiting dilution. We found that NANOG- and POU5F1 (also known as OCT4)-expressing cells still existed in the expanded single cell-derived AF-SCs. Aside from the common mesenchymal characteristics, these clonal AF-SCs also exhibit multiple phenotypes of neural-derived cells such as NES, TUBB3, NEFH, NEUNA60, GALC, and GFAP expressions both before and after neural induction. Most importantly, HPLC analysis showed the evidence of dopamine release in the extract of dopaminergic-induced clonal AF-SCs. The results of this study suggest that besides being an easily accessible and expandable source of fetal stem cells, amniotic fluid will provide a promising source of neural progenitor cells that may be used in future cellular therapies for neurodegenerative diseases and nervous system injuries.

We have developed a general and low-cost, solution-based process that is suitable for the deposition of transparent conducting oxides through spin-coating or inkjet printing under ambient conditions. Highly transparent ͑ϳ95% in the visible portion͒ zinc tin oxide semiconducting thin films were deposited by spin coating. The deposited films were found to be smooth and uniform with an amorphous structure. Enhancement-mode metal-insulator-semiconductor field-effect transistors were fabricated showing a field-effect mobility ͑ FE ͒ as high as 16 cm 2 /V s, a turn-on voltage of 2 V, a current on-to-off ratio greater than 10 5 , and a high on-current of 2.25 mA.Current methods for the production of functional inorganic electronic devices are based on the sequential deposition and etching of selected semiconducting, conducting, and insulating materials. These sequential processes typically involve multiple photolithography and vacuum deposition such as physical or chemical vapor deposition ͑PVD or CVD͒ that contribute to high manufacturing costs. Solution-based deposition processes used for thin-film deposition in standard atmospheric environments such as chemical bath deposition ͑CBD͒, 1-3 digital fabrication 4 ͑e.g., inkjet printing͒, and blanket-coating 5-7 ͑e.g., spin-coating͒ techniques offer the advantages of simplicity, low cost, and high throughput that enable the fabrication of high-performance and ultra-low-cost electronics. Recently, high-mobility, inorganic thin-film transistors ͑TFTs͒ were fabricated using spin-coated SnS 2−x Se x , 5 In 2 Se 3 , 6 and poly-Si 7 semiconductor thin films. Unfortunately, these processes require processing, storage, and characterization in a dry box free of oxygen and moisture.Transparent conducting oxides ͑TCOs͒ such as zinc oxide, tin oxide, and indium oxide are significant for their wide applications used in the microelectronic industry such as flat-panel displays, electromagnetic shielding, organic light-emitting diodes, electrochromatic windows, and most recently active channel materials for TFTs. 8,9 Recently ZnO TFTs with a channel layer formed by radio frequency ͑rf͒ magnetron sputtering deposition, 10-13 pulsed laser deposition ͑PLD͒, 14 and solution-based deposition processes such as spin coating 15,16 have been widely investigated for use in transparent electronic devices. More importantly, the use of transparent conducting multicomponent oxide materials provides the ability to tailor the electrical, optical, physical, and chemical properties of TCO films by altering the chemical composition. [17][18][19] Multicomponent metal oxides composed of heavy-metal cations with an electronic configuration of ͑n − 1͒d 10 ns 0 ͑n ജ 4͒ are promising candidates for preparing amorphous semiconductors. [20][21][22] For example, Nomura et al. have fabricated flexible, transparent TFTs using amorphous In-Ga-Zn-O ͑a-IGZO͒ channel layers prepared by pulse laser deposition that exhibit saturation mobilities as high as 6-9 cm 2 /V s. 23 Zinc tin oxide ͑ZTO͒, zinc-stannate, is a wide-ban...

Chemical bath deposition ͑CBD͒ is an advantageous thin film deposition technique for depositing compound semiconductors at low temperature. In this paper, nickel oxide thin films were prepared by CBD from an aqueous solution composed of nickel sulfate, potassium persulfate, and ammonia at room temperature. Thin film growth mechanisms were studied by using quartz crystal microbalance, UV-vis absorption, and photon correlation spectroscopy. The data indicate that film growth is strongly dependent upon mixing conditions and competes with homogeneous particle formation. No film formation was observed without the addition of persulfate. A growth mechanism based on the combination of particle sticking and molecule level heterogeneous growth is proposed. The as-deposited film contained ␣-Ni͑OH͒ 2 and 4Ni͑OH͒ 2 ·NiOOH·xH 2 O and was converted to nickel oxide ͑NiO͒ by thermal annealing according to thermogravimetric, X-ray diffraction and X-ray photoelectron spectroscopy measurements.NiO is a transition metal oxide that has several potential applications, such as smart window, 1 solar thermal absorber, 2 electrodes for batteries, 3 and photoelectrocatalysts. NiO thin films have been prepared by various techniques, including thermal evaporation, 4 sputtering, 5 spray pyrolysis, 6 sol-gel, 7 chemical vapor deposition, 8 electrochemical deposition, 9 and chemical solution deposition. 10 Chemical solution deposition, also called chemical bath deposition ͑CBD͒, is an advantageous technique because of its low cost and low-temperature operating conditions. There are a few reports on the deposition of NiO thin films by chemical bath deposition. Pramanik and Bhattacharya 11 deposited NiO thin films using nickel sulfate, ammonia, and persulfate aqueous solution at room temperature. The obtained films were polycrystalline NiO with a black appearance. Varkey and Fort 12 deposited nickel oxide thin films using nickel sulfate and ammonia solution over the temperature range 60-80°C. Pejova et al. 13 used a bath containing nickel nitrate and urea at a temperature of 100°C. The as-deposited films were Ni͑OH͒ 2 ·H 2 O with a green appearance and were transformed into nickel oxide films after thermal annealing.In this study, the growth mechanism of NiO thin film by the chemical bath deposition following Pramanik's chemistry was studied in real time by using quartz crystal microbalance, UV-vis absorption, and photon correlation spectroscopy ͑PCS͒. The resulting thin films and particles were characterized by scanning electron microscopy ͑SEM͒, X-ray diffraction ͑XRD͒, UV-vis absorption, X-ray photoelectron spectroscopy ͑XPS͒, and thermogravimetric analysis ͑TGA͒. ExperimentalSolution for CBD was prepared by mixing 40 mL of 1 M nickel sulfate ͑Alfa Aesar͒, 30 mL of 0.25 M potassium persulfate ͑Ald-rich͒, 10 mL of aqueous ammonia ͑28-30% NH 3 , EM Science͒, and 20 mL of deionized water in a 250 mL Pyrex beaker at room temperature ͑recipe A͒. The mixing was carried out by a 5 cm magnetic stir bar with 200 rpm. Substrates used for depositions inc...