Scatter-plots of phase shift values of substantia nigra (A: bilateral SN, B: SN contralateral to the clinically more affected side) and serum uric acid levels in Parkinson’s disease subjects.

<p>The r and p values marked in the figure represent the results of Pearson’s partial correlation analysis adjusting for age, gender, UPDRS III score, and disease duration.</p

Serum Uric Acid and Nigral Iron Deposition in Parkinson’s Disease: A Pilot Study

<div><p>Background</p><p>Uric acid (UA) is an endogenous antioxidant which is known to reduce oxidative stress and also chelate iron ion. Recent studies have provided evidence that UA may play a neuroprotective role in Parkinson’s disease (PD). However, it is unknown whether UA relates to nigral iron deposition, which is a characteristic pathophysiological alteration in PD. The aim of this study was to determine the potential relationship of these two markers in patients with PD.</p><p>Methods</p><p>A total of 30 patients of PD and 25 age- and gender- matched healthy controls underwent 3-Tesla MRI and laboratory tests including serum UA levels. We assessed iron levels by measuring phase shift values using susceptibility-weighted image. Mean phase shift values of the substantia nigra (SN), red nucleus, head of the caudate nucleus, globus pallidus, putamen, thalamus, and frontal white matter were calculated and correlated with serum UA levels.</p><p>Results</p><p>Serum UA levels were significantly decreased in the PD patients than in the controls. Phase shift values in bilateral SN were significantly increased in the PD patients than in the controls. There was no significant correlation between serum UA levels and nigral phase shift values.</p><p>Conclusions</p><p>As previous studies, low serum UA level and increased nigral iron content in the PD was reconfirmed in this study. However, we failed to find the relationship between these two markers. Our data suggest that serum UA may not be important determinant of nigral iron deposition in PD.</p></div

The correlation between the phase shift values in seven brain regions of healthy controls and postmortem iron concentrations, as reported by Hallgren and Sourander.

<p>CA = head of caudate nucleus; FWM = frontal white matter; GP = globus pallidus; PU = putamen; RN = red nucleus; SN = substantia nigra; TH = thalamus.</p

Quasi-Stem Cells Derived from Human Somatic Cells by Chemically Modified Carbon Nanotubes

Surface modification of micro- and nanotopography was employed to alter the surface properties of scaffolds for controlling cell attachment, proliferation, and differentiation. This study reports a method for generating multinucleated colonies as evidenced by spherical colony formation through nanotopography-induced expression of reprogramming factors in human dermal fibroblasts. Colony formation was achieved by subjecting the cells to specific environments such as culturing with single-walled carbon nanotubes and poly-l-lysine (PLL-SWCNTs). We obtained encouraging results showing that PLL-SWCNT treatment transformed fibroblast cells, and the transformed cells expressed the pluripotency-associated factors OCT4, NANOG, and SOX2 in addition to TRA-1-60 and SSEA-4, which are characteristic stem cell markers. Downregulation of lamin A/C, HDAC1, HDAC6, Bcl2, cytochrome c, p-FAK, p-ERK, and p-JNK and upregulation of H3K4me3 and p-p38 were confirmed in the generated colonies, indicating reprogramming of cells. This protocol increases the possibility of successfully reprogramming somatic cells into induced pluripotent stem cells (iPSCs), thereby overcoming the difficulties in iPSC generation such as genetic mutations, carcinogenesis, and undetermined risk factors

In Situ Fabrication of Nano Transistors by Selective Deposition of a Gate Dielectric around Carbon Nanotubes

The CNT-SiO₂ core–shell structure is particularly appealing because the insulating SiO₂ layer wraps around the CNTs, functioning as a gate dielectric. However, it is still a challenge to expose both end-caps of the structure for enabling them to serve as electrodes, which additionally requires complicated postprocesses. Here, we present a unique CNTs-SiO₂ core–shell structure where both ends are uncovered with SiO₂ in a “peeled-wire” structure. In this structure, SiO₂ particles partially encapsulate the CNTs during the synthesis, resulting in both end-caps of the nanotube being self-exposed and electrically conductive. The field-effect transistor build-up with this structure exhibits p-type characteristics with a linear conductance behavior on <i>I</i>_d–<i>V</i>_d output performance. This approach for making self-formed electrodes in the CNT-SiO₂ core–shell structure provides a simple and efficient way for applying them to future nanodevices in terms of process simplicity and cost effectiveness

Large-Scale Direct Patterning of Aligned Single-Walled Carbon Nanotube Arrays Using Dip-Pen Nanolithography

The strength of dip-pen nanolithography (DPN) is the ability to create nano- or microarrays of organic compounds and nanomaterials in a nondestructive and direct-write manner. However, transporting large-sized ink materials, such as carbon nanotubes (CNTs), has been a significant challenge. We report a direct-write patterning of aligned single-walled carbon nanotube (SWNT) arrays on silicon oxide using DPN. The patterned SWNT arrays show a high degree of alignment and controllable width ranging from 2 μm down to 8 nm. Furthermore, field-effect transistors based on these SWNT arrays show p-type characteristic. High-throughput patterning of the aligned SWNTs over a large area was also achieved via polymer pen lithography (PPL). The reported technique will further expand the application of SWNTs to diverse nanoelectronic devices

Synthesis and Biological Activity of Tetrameric Ribitol Phosphate Fragments of Staphylococcus aureus Wall Teichoic Acid

A systematically designed and synthesized ribitol phosphate (RboP) oligomer using a series of building blocks, which make up the wall teichoic acid (WTA) of S. aureus, is presented. Based on the use of a solution-phase phosphodiester synthesis, a library of ribitol phosphate tetramers, decorated with d-alanine and <i>N</i>-acetylglucosamine (GlcNAc), were generated. The synthesized RboP tetramers showed increased cytokine levels in mice in a subcutaneous air pouch model

Single-Bundle Carbon-Nanotube-Bridged Nanorod Devices with Control of Gap Length

We report a convenient method for the mass production of single-bundle carbon-nanotube (CNT)-bridged nanorod structures with controlled nanoscale gap. In this research, multisegmented metal nanorods are electrochemically grown on the surface of CNTs that are vertically aligned at inside the pores of anodic aluminum oxide membrane. Selective etching of central nickel (Ni) metal nanorod among three nanorod segments (Au–Ni–Au) provides nanodevice structures with CNT channel in the middle bringing between metal nanorod electrodes on both ends. Our method offers a simple pathway for production of nanoscale gap controlled CNT based devices with desired length of both channel and electrodes. This CNT-bridged nanorod structure holds advantages of each constituent, including the electrical properties of CNTs such as a ambipolar characteristic, and precise growth control and alignment of nanorods. This method provides an easy and convenient approach to fabricate various kinds of nanoscale structure-based electronic devices

Random Networks of Single-Walled Carbon Nanotubes Promote Mesenchymal Stem Cell’s Proliferation and Differentiation

Studies on the interaction of cells with single-walled carbon nanotubes (SWCNTs) have been receiving increasing attention owing to their potential for various cellular applications. In this report, we investigated the interactions between biological cells and nanostructured SWCNTs films and focused on how morphological structures of SWCNT films affected cellular behavior such as cell proliferation and differentiation. One directionally aligned SWCNT Langmuir−Blodgett (LB) film and random network SWCNT film were fabricated by LB and vacuum filteration methods, respectively. We demonstrate that our SWCNT LB and network film based scaffolds do not show any cytotoxicity, while on the other hand, these scaffolds promote differentiation property of rat mesenchymal stem cells (rMSCs) when compared with that on conventional tissue culture polystyrene substrates. Especially, the SWCNT network film with average thickness and roughness values of 95 ± 5 and 9.81 nm, respectively, demonstrated faster growth rate and higher cell thickness for rMSCs. These results suggest that systematic manipulation of the thickness, roughness, and directional alignment of SWCNT films would provide the convenient strategy for controlling the growth and maintenance of the differentiation property of stem cells. The SWCNT film could be an alternative culture substrate for various stem cells, which often require close control of the growth and differentiation properties

Metal-Free Carbon-Based Nanomaterial Coatings Protect Silicon Photoanodes in Solar Water-Splitting

The decreasing cost of silicon-based photovoltaics has enabled significant increases in solar electricity generation worldwide. Silicon photoanodes could also play an important role in the cost-effective generation of solar fuels, but the most successful methods of photoelectrode passivation and performance enhancement rely on a combination of precious metals and sophisticated processing methods that offset the economic arguments for silicon. Here we show that metal-free carbon-based nanomaterial coatings deposited from solution can protect silicon photoanodes carrying out the oxygen evolution reaction in a range of working environments. Purified semiconducting carbon nanotubes (CNTs) act as a hole extraction layer, and a graphene (Gr) capping layer both protects the CNT film and acts as a hole exchange layer with the electrolyte. The performance of semiconducting CNTs is found to be superior to that of metallic or unsorted CNTs in this context. Furthermore, the insertion of graphene oxide (GO) between the n-Si and CNTs reduces the overpotential relative to photoanodes with CNTs deposited on hydrogen-passivated silicon. The composite photoanode structure of n-Si/GO/CNT/Gr shows promising performance for oxygen evolution and excellent potential for improvement by optimizing the catalytic properties and stability of the graphene protective layer