Functional neural differentiation of human adipose tissue-derived stem cells using bFGF and forskolin

<p>Abstract</p> <p>Background</p> <p>Adult mesenchymal stem cells (MSCs) derived from adipose tissue have the capacity to differentiate into mesenchymal as well as endodermal and ectodermal cell lineage <it>in vitro</it>. We characterized the multipotent ability of human adipose tissue-derived stem cells (hADSCs) as MSCs and investigated the neural differentiation potential of these cells.</p> <p>Results</p> <p>Human ADSCs from earlobe fat maintained self-renewing capacity and differentiated into adipocytes, osteoblasts, or chondrocytes under specific culture conditions. Following neural induction with bFGF and forskolin, hADSCs were differentiated into various types of neural cells including neurons and glia <it>in vitro</it>. In neural differentiated-hADSCs (NI-hADSCs), the immunoreactivities for neural stem cell marker (nestin), neuronal markers (Tuj1, MAP2, NFL, NFM, NFH, NSE, and NeuN), astrocyte marker (GFAP), and oligodendrocyte marker (CNPase) were significantly increased than in the primary hADSCs. RT-PCR analysis demonstrated that the mRNA levels encoding for ABCG2, nestin, Tuj1, MAP2, NFL, NFM, NSE, GAP43, SNAP25, GFAP, and CNPase were also highly increased in NI-hADSCs. Moreover, NI-hADSCs acquired neuron-like functions characterized by the display of voltage-dependent tetrodotoxin (TTX)-sensitive sodium currents, outward potassium currents, and prominent negative resting membrane potentials under whole-cell patch clamp recordings. Further examination by RT-PCR showed that NI-hADSCs expressed high level of ionic channel genes for sodium (SCN5A), potassium (MaxiK, Kv4.2, and EAG2), and calcium channels (CACNA1C and CACNA1G), which were expressed constitutively in the primary hADSCs. In addition, we demonstrated that Kv4.3 and Eag1, potassium channel genes, and NE-Na, a TTX-sensitive sodium channel gene, were highly induced following neural differentiation.</p> <p>Conclusions</p> <p>These combined results indicate that hADSCs have the same self-renewing capacity and multipotency as stem cells, and can be differentiated into functional neurons using bFGF and forskolin.</p

Fabrication and characterization of silicon wire solar cells having ZnO nanorod antireflection coating on Al-doped ZnO seed layer

In this study, we have fabricated and characterized the silicon [Si] wire solar cells with conformal ZnO nanorod antireflection coating [ARC] grown on a Al-doped ZnO [AZO] seed layer. Vertically aligned Si wire arrays were fabricated by electrochemical etching and, the pn junction was prepared by spin-on dopant diffusion method. Hydrothermal growth of the ZnO nanorods was followed by AZO film deposition on high aspect ratio Si microwire arrays by atomic layer deposition [ALD]. The introduction of an ALD-deposited AZO film on Si wire arrays not only helps to create the ZnO nanorod arrays, but also has a strong impact on the reduction of surface recombination. The reflectance spectra show that ZnO nanorods were used as an efficient ARC to enhance light absorption by multiple scattering. Also, from the current-voltage results, we found that the combination of the AZO film and ZnO nanorods on Si wire solar cells leads to an increased power conversion efficiency by more than 27% compared to the cells without it. © 2012 Baek et al.1

COMBUSTION CHARACTERISTICS AND EMISSION OF HAZARDOUS AIR POLLUTANTS IN COMMERCIAL FLUIDIZED BED COMBUSTORS FOR SEWAGE SLUDGE

Since the disposal of sewage sludge in ocean has been prohibited recently according to London Dumping Convention, technological need for treating sewage sludge safely and efficiently are getting increased in Korea. FBC (Fluidized Bed Combustor) technology has been selected and utilized as one of the alternatives because of combustible content in sludge, on-going process development to maintain the best combustion efficiency, and good heat recovery for energy utilization. In this paper, the process and combustion characteristics of commercially operating FBC incineration plants with the capacity ranging from 50 – 150 tons of sludge per day were investigated by comparing emission data from 4 different plants. Concentrations of hazardous gaseous pollutants (HAPs) such as fine particulate matter, heavy metals, and dioxin from sludge combustion before and after air pollution control devices were measured and analyzed at commercial operating conditions of one typical incinerator. Most of emission data at stack showed under the environmental regulatory limits. Mercury and some heavy metals emission have been reduced significantly as co-beneficial effect since the air pollution control configuration was well arranged and installed to control the regulatory gases such as NOx, SO2, particulates, and dioxin. Sludge, especially generated from industrial plants, contained measurable amounts of acidic materials and heavy metals including Hg. Therefore, such metal emission should receive an attention by monitoring them and further mass balance study for better understanding their fates in the process must proceed in future

Visible emission from Ce-doped ZnO nanorods grown by hydrothermal method without a post thermal annealing process

Visible light-emitting Ce-doped ZnO nanorods [NRs] without a post thermal annealing process were grown by hydrothermal method on a Si (100) substrate at a low temperature of 90°C. The structural investigations of Ce-doped ZnO NRs showed that the Ce3+ ions were successfully incorporated into the ZnO lattice sites without forming unwanted Ce-related compounds or precipitates. The optical investigation by photoluminescence spectra shows that the doped Ce3+ ions in the ZnO NRs act as an efficient luminescence center at 540 nm which corresponds to the optical transition of 5d → 4f orbitals in the Ce3+ ions. The photoluminescence intensity of the Ce-doped ZnO NRs increased with the increasing content of the Ce-doping agent because the energy transfer of the excited electrons in ZnO to the Ce3+ ions would be enhanced by increased Ce3+ ions

Scattering of irregular waves by vertical cylinders

author's final versionAn analytical model has been developed that can predict the scattering of irregular waves normally incident upon an array of vertical cylinders. To examine the predictability of the developed model, laboratory experiments have been made for the reflection and transmission of irregular waves from arrays of circular cylinders with various diameters and gap widths. Though the overall agreement between measurement and calculation is fairly good, the model tends to over- and under-predict the reflection and transmission coefficients, respectively, as the gap width decreases. The model also underestimates the energy loss coefficients for small gap widths because it neglects the evanescent waves near the cylinders. The peaks of the measured spectra of the reflected and transmitted waves slightly shift towards higher frequencies compared with that of the incident wave spectrum probably because of the generation of shorter period waves due to the interference of the cylinders. Both model and experimental data show that the wave reflection and transmission become larger and smaller, respectively, as the wave steepness increases, which is a desirable feature of the cylinder breakwaters

Imaging Features of Adult Choledochal Cysts: a Pictorial Review

Choledochal cysts are rare congenital anomalies which are principally diagnosed by disproportional dilatation of the extrahepatic bile ducts. In addition, choledochal cysts are believed to arise from the anomalous union of the common bile duct and pancreatic duct outside the duodenal wall which is also proximal to the sphincter of the Oddi mechanism. The various types of choledochal cysts have been classified on the basis of these anomalous unions (Komi classification) and their anatomical locations (Todani classification). The multidetector computed tomography with reformatted imaging, magnetic resonance cholangiopancreatography, and an endoscopic retrograde cholangiography represent the important techniques providing the anatomical resolution and detail required to properly diagnose and classify choledochal cysts and their associated abnormal features of the biliary tree, as well as their pancreaticobile duct union. This study describes the various imaging features of a choledochal cyst in adults according to the various types of anomalous unions of the pancreaticobile duct according to Komi's classification and anatomic location according to Todani's classification. Lastly, we also review and discuss the associated abnormal findings developed in biliary systems

Osseointegration of Implants Surface-Treated with Various Diameters of TiO 2

The aim of this study was to evaluate the osseointegration of implants which were surface-treated with various diameters of TiO2 nanotubes (30 nm, 70 nm, and 100 nm) in rabbit. Resorbable blast media (RBM) surfaced implants (Osstem, Busan, Korea) 3.5 mm in diameter and 8.5 mm in length were designated as the control group and the implants surface-treated with various diameters of nanotubes (30 nm, 70 nm, and 100 nm) with the same shapes were designated as the experimental groups. The implants were maintained unloaded for 4 and 12 weeks. After this period, the animals were sacrificed and micro-CT analysis, histomorphometric analysis (bone to implant contact (BIC), bone volume (BV)), and removal torque test were performed. Micro-CT analysis, histomorphometric analysis, and removal torque test results all showed the similar pattern, showing that 70 nm experimental group had the highest value at 4 weeks while 30 nm experimental group had the highest value at 12 weeks. Therefore, on the basis of the results above, it can be concluded that 30 nm and 70 nm TiO2 nanotubes may have positive effects on osteogenesis and osseointegration depending on the healing time

Regeneration Ecology of Chrysopogon aucheri and Cymbopogon jwarancusa in Grasslands of Upland Balochistan , Pakistan

Field experiments were conducted to investigate the seed attributes, movements and fates of dispersal units, and seedling establishment of Chrysopogon aucheri and Cymbopogon jwarancusa in a representative grassland ecosystem in upland Balochistan, Pakistan. Cymbopogon jwarancusa had more filled and viable caryopses than Chrysopogon aucheri. Seeds (spikelets) of both species had similar morphological features. Chrysopogon aucheri had one dispersal unit, a triplet spikelet. Cymbopogon jwarancusa had four types of dispersal units: a paired spikelet, a partial raceme, an entire raceme, and a partial inflorescence comprised of two racemes. Paired spikelets and partial racemes of Cymbopogon jwarancusa had greater mean dispersal distances (94 and 101 cm) from the edge of the basal crown of marked plants to the ground surface than triplet spikelets of Chrysopogon aucheri (79 cm). Spikelets of Cymbopogon jwarancusa and Chrysopogon aucheri moved mean distances of 26 and 32 cm, respectively, on the ground surface before becoming trapped in a microhabitat. The mean angle of dispersal for both species was toward the northeast, according to the prevailing wind direction. An ant (Tica verona) was the only detected seed (spikelet) predator for Chrysopogon aucheri. Both species had a weakly persistent soil seed bank, with higher amounts of seeds found under plant canopies compared to open interspaces. The recruitment of Chrysopogon aucheri and Cymbopogon jwarancusa seedlings from the natural seed bank was monitored in seven different microhabitats under natural and above-normal precipitation regimes . Above-normal precipitation increased seedling recruitment for both species in all microhabitats. Cymbopogon jwarancusa had higher seedling densities than Chrysopogon auchfiri. Seedling survival and tiller development for both species were greatest in the gravel microhabitat in the natural precipitation treatment. Monsoon rains in late July enhanced emergence of both species from recently dispersed seeds but emerged seedlings did not survive to the end of the growing season. The field studies indicate that Cymbopogon jwarancusa has a greater regeneration potential than Chrysopogon aucheri in this grassland ecosystem in upland Balochistan. It may be difficult to increase the composition of Chrysopogon aucheri, the more desirable species in these grasslands, when using management techniques that rely on natural regeneration