Comparison of Optical and Electrical Sensor Characteristics for Efficient Analysis of Attachment and Detachment of Aptamer.

Nucleic acid aptamer-based research has focused on achieving the highest performance for bioassays. However, there are limitations in evaluating the affinity for the target analytes in these nucleic acid aptamer-based bioassays. In this study, we mainly propose graphene oxide (GO)-based electrical and optical analyses to efficiently evaluate the affinity between an aptamer and its target. We found that an aptamer-coupled GO-based chip with an electrical resistance induced by a field-effect transistor, with aptamers as low as 100 pM, can detect the target, thrombin, at yields as low as 250 pM within five minutes. In the optical approach, the fluorescent dye-linked aptamer, as low as 100 nM, was efficiently used with GO, enabling the sensitive detection of thrombin at yields as low as 5 nM. The cantilever type of mechanical analysis also demonstrated the intuitive aptamer-thrombin reaction in the signal using dBm units. Finally, a comparison of electrical and optical sensors' characteristics was introduced in the attachment and detachment of aptamer to propose an efficient analysis that can be utilized for various aptamer-based research fields.

Rapid Access to Ordered Mesoporous Carbons for Chemical Hydrogen Storage.

Ordered mesoporous carbon materials offer robust network of organized pores for energy storage and catalysis applications, but suffer from time-consuming and intricate preparations hindering their widespread use. Here we report a new and rapid synthetic route for a N-doped ordered mesoporous carbon structure through a preferential heating of iron oxide nanoparticles by microwaves. A nanoporous covalent organic polymer is first formed in situ covering the hard templates of assembled nanoparticles, paving the way for a long-range order in a carbonaceous nanocomposite precursor. Upon removal of the template, a well-defined cubic mesoporous carbon structure was revealed. The ordered mesoporous carbon was used in solid state hydrogen storage as a host scaffold for NaAlH4 , where remarkable improvement in hydrogen desorption kinetics was observed. The state-of-the-art lowest activation energy of dehydrogenation as a single step was attributed to their ordered pore structure and N-doping effect.

Complete mitochondrial DNA sequence of Norwegian skates (Raja brachyuran Lafont, 1871) imported to Korea.

In this study, the complete mitochondrial genome of Norwegian skates imported to Korea was sequenced with a circular molecule of 17,121 bp, which consisted of 13 protein-coding genes (PCGs), 2 ribosomal RNAs, 22 transfer RNA genes, and a control region (D-loop). And among these sequences, 193 bp sequence in the D-loop of the genus Raja suggested the possibility of being used as a genetic marker for classification of Raja and Dipturus species. The BI phylogenetic tree by using the nucleotide sequences of 13 PCGs from 15 available mitogenomes of family Rajidae confirmed also that Norwegian skates imported to Korea form a group with Raja brachyura species with high branch value, and that this was a species of Raja brachyura. As above, these results would be expected to provide for the further understanding on the phylogenetic relationship, taxonomic classification and phylogeography of the family Rajidae.

The complete mitochondrial genome of Sardinella zunasi (Clupeiformes: Clupeidae).

The complete mitogenome of Sardinella zunasi was determined by next-generation sequencing. The S. zunasi mitogenome was a circular 16,307 bp molecule that contained 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and one control region (D-loop). The gene arrangement was consistent with other Sardinella mitogenomes. The phylogenetic relationships of 29 Clupeoidei species based on 13 protein-coding genes from the available mitogenomes were analyzed. Sardinella zunasi clustered with Sardinella among Clupeidae, suggesting a closer relationship with this genus. These results will be useful for understanding the phylogenetic relationships, taxonomic classification, and phylogeography of the genus Sardinella relative to other genera of Clupeoidei.

Asynchronous Double Schiff Base Formation of Pyrazole Porous Polymers for Selective Pd Recovery.

Pyrazole-linked covalent organic polymer is synthesized using an asynchronous double Schiff base from readily available monomers. The one-pot reaction features no metals as a building block or reagent, hence facilitating the structural purity and industrial scalability of the design. Through a single-crystal study on a model compound, the double Schiff base formation is found to follow syn addition, a kinetically favored product, suggesting that reactivity of the amine and carbonyls dictate the order and geometry of the framework building. The highly porous pyrazole polymer COP-214 is chemically resistant in reactive conditions for over two weeks and thermally stable up to 425 °C in air. COP-214 shows well-pronounced gas capture and selectivities, and a high CO2/N2 selectivity of 102. The strongly coordinating pyrazole sites show rapid uptake and quantitative selectivity of Pd (II) over several coordinating metals (especially Pt (II)) at all pH points that are tested, a remarkably rare feature that is best explained by detailed analysis as the size-selective strong coordination of Pd onto pyrazoles. Density functional theory (DFT) calculations show energetically favorable Pd binding between the metal and N-sites of COP-214. The polymer is reusable multiple times without loss of activity, providing great incentives for an industrial prospect.

Monolithic 1 × 8 DWDM Silicon Optical Transmitter Using an Arrayed-Waveguide Grating and Electro-Absorption Modulators for Switch Fabrics in Intra-Data-Center Interconnects.

In this study, we propose an eight-channel monolithic optical transmitter using silicon electro-absorption modulators (EAMs) based on free-carrier injection by Schottky junctions. The transmitter consists of a 1 × 8 silicon arrayed-waveguide grating (AWG) and eight 500-µm-long EAMs on a 5.41 × 2.84 mm2 footprint. It generates eight-channel dense wavelength-division multiplexing (DWDM) outputs with 1.33 nm channel spacing (Δλ) in the C-band from a single broadband light source and modulates each channel with over 3 dB modulation depth at 6 V peak-to-peak. The experimental results showed that the feasibility of a homogeneous silicon DWDM transmitter with a single light source for switch fabrics in intra-data-center interconnects over heterogeneous integration with regards to more complementary metal-oxide-semiconductor (CMOS) compatibility.

Inversion of Dispersion: Colloidal Stability of Calixarene-Modified Metal-Organic Framework Nanoparticles in Nonpolar Media.

Making metal-organic frameworks (MOFs) that are stabilized in nonpolar media is not as straightforward as making their inorganic nanoparticle counterparts, since surfactants penetrate through the porous structures or dissolve the secondary building units (SBUs) through ligand-exchange linker modulator mechanisms. Herein, we report that calixarenes stabilize UIO-66 nanoparticles effectively by remaining outside the grains through size exclusion, without pores becoming blocked, all the while providing amphiphilicity that permits the formation of stable colloidal dispersions with much narrower size distributions. Using the UIO-66 dispersed solutions, we show that smooth films from an otherwise immiscible polystyrene can be made feasibly.

Tissue distribution following 28 day repeated oral administration of aluminum-based nanoparticles with different properties and the in vitro toxicity.

The tissue distribution and toxicity of nanoparticles (NPs) depend on their physical and chemical properties both in the manufactured condition and within the biological system. We characterized three types of commercially available aluminum-based NPs (Al-NPs), two rod-type aluminum oxide NPs (Al2 O3 , AlONPs), with different aspect ratios (short [S]- and long [L]-AlONPs), and spherical aluminum cerium oxide NPs (AlCeO3 , AlCeONPs). The surface area was in order of the S-AlONPs > L-AlONPs > AlCeONPs. Very importantly, we found that AlCeONPs is Al2 O3 -coated CeO2 NPs, but not AlCeO3 NPs, and that the Al level in AlCeONPs is approximately 20% of those in S- and L-AlONPs. All three types of Al-NPs were slightly ionized in gastric fluid and rapidly particlized in the intestinal fluid. There were no significant differences in the body weight gain following 28 days of repeated oral administration of the three different types of Al-NPs. All Al-NPs elevated Al level in the heart, spleen, kidney and blood at 24 hours after the final dose, accompanied by the altered tissue level of redox reaction-related trace elements. Subsequently, in four types of cells derived from the organs which Al-NPs are accumulated, H9C2 (heart), HEK-293 (kidney), splenocytes and RAW264.7 (blood), S-AlONPs showed a very low uptake level and did not exert significant cytotoxicity. Meanwhile, cytotoxicity and uptake level were the most remarkable in cells treated with AlCeONPs. In conclusion, we suggest that the physicochemical properties of NPs should be examined in detail before the release into the market to prevent unexpected adverse health effects.

Nano-sized iron particles may induce multiple pathways of cell death following generation of mistranscripted RNA in human corneal epithelial cells.

Iron is closely associated with an ambient particulate matters-induced inflammatory response, and the cornea that covers the front of the eye, is among tissues exposed directly to ambient particulate matters. Prior to this study, we confirmed that nano-sized iron particles (FeNPs) can penetrate the cornea. Thus, we identified the toxic mechanism of FeNPs using human corneal epithelial cells. At 24h after exposure, FeNPs located inside autophagosome-like vacuoles or freely within human corneal epithelial cells. Level of inflammatory mediators including nitric oxide, cytokines, and a chemokine was notably elevated accompanied by the increased generation of reactive oxygen species. Additionally, cell proliferation dose-dependently decreased, and level of multiple pathways of cell death-related indicators was clearly altered following exposure to FeNPs. Furthermore, expression of gene encoding DNA binding protein inhibitor (1, 2, and 3), which are correlated to inhibition of the binding of mistranscripted RNA, was significantly down-regulated. More importantly, expression of p-Akt and caspase-3 and conversion to LC3B-II from LC3B-I was enhanced by pretreatment with a caspase-1 inhibitor. Taken together, we suggest that FeNPs may induce multiple pathways of cell death via generation of mistranscripted RNA, and these cell death pathways may influence by cross-talk. Furthermore, we propose the need of further study for the possibility of tumorigenesis following exposure to FeNPs.

Comparison of distribution and toxicity of different types of zinc-based nanoparticles.

Zinc-based nanoparticles (Zn-NPs), mainly zinc oxide (ZnO) NPs, have promising application in a wide area, but their potential harmful effects on environment and human health have been continuously raised together with their high dissolution rate. In this study, we coated the surface of ZnO NPs with phosphate (ZnP NPs) and sulfide (ZnS NPs) which have very low solubility in water, administered orally (0.5 and 1 mg/kg) to mice for 28 days, and then compared their biodistribution and toxicity. As expected, ZnO NPs were rapidly ionized in an artificial gastric fluid. On the other hand, ZnO NPs were more particlized in an artificial intestinal fluid than ZnP and ZnS NPs. After repeated dosing, all three types of Zn-NPs the most distributed in the spleen and thymus and altered the level of redox reaction-related metal ions in the tissues. We also found that three types of Zn-NPs clearly disturb tissue ion homeostasis and influence immune regulation function. However, there were no remarkable difference in distribution and toxicity following repeated exposure of three types of Zn-NPs, although Na+ and K+ level in the spleen and thymus were notably higher in mice exposed to ZnO NPs compared to ZnP and ZnS NPs. Taken together, we suggest that all three types of Zn-NPs may influence human health by disrupting homeostasis of trace elements and ions in the tissues. In addition, the surface transformation of ZnO NPs with phosphate and sulfide may not attenuate toxicity due to the higher particlization rate of ZnO NPs in the intestine, at least in part. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1363-1374, 2017.

Deleterious effects in reproduction and developmental immunity elicited by pulmonary iron oxide nanoparticles.

With the extensive application of iron oxide nanoparticles (FeNPs), attention about their potential risks to human health is also rapidly raising, particularly in sensitive subgroups such as pregnant women and babies. In this study, we a single instilled intratracheally FeNPs (1, 2, and 4mg/kg) to the male and female parent mice, mated, then assessed reproductive toxicity according to the modified OECD TG 421. During the pre-mating period (14 days), two female parent mice died at 4mg/kg dose, and the body weight gain dose-dependently decreased in male and female parent mice exposed to FeNPs. Additionally, iron accumulation and the enhanced expression of MHC class II molecules were observed in the ovary and the testis of parent mice exposed to the highest dose of FeNPs, and the total sex ratio (male/female) of the offspring mice increased in the groups exposed to FeNPs. Following, we a single instilled intratracheally to their offspring mice with the same doses and evaluated the immunotoxic response on day 28. The increased mortality and significant hematological- and biochemical- changes were observed in offspring mice exposed at 4mg/kg dose, especially in female mice. More interestingly, balance of the immune response was shifted to a different direction in male and female offspring mice. Taken together, we conclude that the NOAEL for reproductive and developmental toxicity of FeNPs may be lower than 2mg/kg, and that female mice may show more sensitive response to FeNPs exposure than male mice. Furthermore, we suggest that further studies are necessary to identify causes of both the alteration in sex ratio of offspring mice and different immune response in male and female offspring mice.

Subchronic immunotoxicity and screening of reproductive toxicity and developmental immunotoxicity following single instillation of HIPCO-single-walled carbon nanotubes: purity-based comparison.

Impurity has been suggested as an important factor determining toxicity following exposure to single-walled carbon nanotubes (SWCNTs). In this study, we first compared immunotoxicity based on iron content on day 90 after a single intratracheal instillation of SWCNTs in male and female mice. The inflammatory responses were generally stronger in mice exposed to acid-purified (P)-SWCNTs compared to raw (R)-SWCNTs. In addition, both R- and P-SWCNTs induced Th1-polarized immune responses with apoptotic death of BAL cells and systemically impaired the function of antigen-presenting cells (APC). We also screened reproductive and developmental toxicity by cohabitating male and female mice on day 14 after instillation. Interestingly, the pregnancy rate rapidly decreased following exposure to both types of SWCNTs, especially R-SWCNTs. In addition, we investigated developmental immunotoxicity of the offspring on day 28 after exposure to both types of SWCNTs. Their hematological changes were clearer relative to those of the parents and a significant decrease in the alkaline phosphatase and potassium levels was observed in mice of both sexes exposed to the higher dose of R- and P-SWCNTs. In conclusion, we suggest that SWCNTs may induce Th1-polarized immune responses accompanied by suppression of APC function on day 90 after a single instillation without significant iron content dependance. In addition, the consecutive exposure of SWCNTs to the subsequent generation may exacerbate metabolic and hematological disturbance. Furthermore, our results underscore the need to clarify the reproductive and developmental health effects of SWCNTs.

A higher aspect ratio enhanced bioaccumulation and altered immune responses due to intravenously-injected aluminum oxide nanoparticles.

Aluminum oxide nanoparticles (AlO NP) have been widely utilized in a variety of areas, including in the optical, biomedical and electronic fields and in the overall development of nanotechnologies. However, their toxicological profiles are still not fully developed. This study compared the distribution and immunotoxicity of two rod-types of AlO NP. As reported previously, the two types of AlO NP had different aspect ratios (long-type: 6.2 ± 0.6, short-type: 2.1 ± 0.4), but the size and surface charge were very similar. On Day 14 after a single intravenous (IV) injection (1.25 or 5 mg/kg), both AlO NP accumulated primarily in the liver and spleen and altered the levels of redox response-related elements. The accumulated level was higher in mice exposed to the long-type AlO NP compared to the short-type. Additionally, it was noted that the levels of IL-1ß, IL-8 and MCP-1 were enhanced in the blood of mice exposed to both types of AlO NP and the percentages of neutrophils and monocytes among all white blood cells were increased only in mice injected with the long-type AlO NP (5 mg/kg). In addition, as compared to the control, co-expression of CD80 and CD86 (necessary for antigen presentation) on splenocytes together with a decreased expression of chemotaxis-related marker (CD195) was attenuated by exposure to the AlO NP, especially the long-type. Taken together, the data suggest that accumulation following a single IV injection with rod-types of AlO NP is strengthened by a high aspect ratio and, subsequently, this accumulation has the potential to influence immune functions in an exposed host.

Single-walled carbon nanotubes disturbed the immune and metabolic regulation function 13-weeks after a single intratracheal instillation.

Due to their unique physicochemical properties, the potential health effects of single-walled carbon nanotubes (SWCNTs) have attracted continuous attention together with their extensive application. In this study, we aimed to identify local and systemic health effects following pulmonary persistence of SWCNTs. As expected, SWCNTs remained in the lung for 13 weeks after a single intratracheal instillation (50, 100, and 200µg/kg). In the lung, the total number of cells and the percentages of lymphocytes and neutrophils significantly increased at 200µg/kg compared to the control, and the Th1-polarized immune response was induced accompanying enhanced expression of tissue damage-related genes and increased release of chemokines. Additionally, SWCNTs enhanced the expression of antigen presentation-related proteins on the surface of antigen-presenting cells, however, maturation of dendritic cells was inhibited by their persistence. As compared to the control, a significant increase in the percentage of neutrophils and a remarkable decrease of BUN and potassium level were observed in the blood of mice treated with the highest dose. This was accompanied by the down-regulation of the expression of antigen presentation-related proteins on splenocytes. Moreover, protein and glucose metabolism were disturbed with an up-regulation of fatty acid ß-oxidation. Taken together, we conclude that SWCNTs may induce adverse health effects by disturbing immune and metabolic regulation functions in the body. Therefore, careful application of SWCNTs is necessary for the enforcement of safety in nano-industries.

Biodistribution and toxicity of spherical aluminum oxide nanoparticles.

With the rapid development of the nano-industry, concerns about their potential adverse health effects have been raised. Thus, ranking accurately their toxicity and prioritizing for in vivo testing through in vitro toxicity test is needed. In this study, we used three types of synthesized aluminum oxide nanoparticles (AlONPs): γ-aluminum oxide hydroxide nanoparticles (γ-AlOHNPs), γ- and α-AlONPs. All three AlONPs were spherical, and the surface area was the greatest for γ-AlONPs, followed by the α-AlONPs and γ-AlOHNPs. In mice, γ-AlOHNPs accumulated the most 24 h after a single oral dose. Additionally, the decreased number of white blood cells (WBC), the increased ratio of neutrophils and the enhanced secretion of interleukin (IL)-8 were observed in the blood of mice dosed with γ-AlOHNPs (10 mg kg(-1)). We also compared their toxicity using four different in vitro test methods using six cell lines, which were derived from their potential target organs, BEAS-2B (lung), Chang (liver), HACAT (skin), H9C2 (heart), T98G (brain) and HEK-293 (kidney). The results showed γ-AlOHNPs induced the greatest toxicity. Moreover, separation of particles was observed in a transmission electron microscope (TEM) image of cells treated with γ-AlOHNPs, but not γ-AlONPs or α-AlONPs. In conclusion, our results suggest that the accumulation and toxicity of AlONPs are stronger in γ-AlOHNPs compared with γ-AlONPs and α-AlONPs owing their low stability within biological system, and the presence of hydroxyl group may be an important factor in determining the distribution and toxicity of spherical AlONPs.