Printing three-dimensional tissue analogues with decellularized extracellular matrix bioink

The ability to print and pattern all the components that make up a tissue (cells and matrix materials) in three dimensions to generate structures similar to tissues is an exciting prospect of bioprinting. However, the majority of the matrix materials used so far for bioprinting cannot represent the complexity of natural extracellular matrix (ECM) and thus are unable to reconstitute the intrinsic cellular morphologies and functions. Here, we develop a method for the bioprinting of cell-laden constructs with novel decellularized extracellular matrix (dECM) bioink capable of providing an optimized microenvironment conducive to the growth of three-dimensional structured tissue. We show the versatility and flexibility of the developed bioprinting process using tissue-specific dECM bioinks, including adipose, cartilage and heart tissues, capable of providing crucial cues for cells engraftment, survival and long-term function. We achieve high cell viability and functionality of the printed dECM structures using our bioprinting method.open11349353sciescopu

Restoration of optic neuropathy

Optic neuropathy refers to disorders involving the optic nerve (ON). Any damage to ON or ON-deriving neurons, the retinal ganglion cells (RGCs), may lead to the breakdown of the optical signal transmission from the eye to the brain, thus resulting in a partial or complete vision loss. The causes of optic neuropathy include trauma, ischemia, inflammation, compression, infiltration, and mitochondrial damages. ON injuries include primary and secondary injuries. During these injury phases, various factors orchestrate injured axons to die back and become unable to regenerate, and these factors could be divided into two categories: extrinsic and intrinsic. Extrinsic inhibitory factors refer to the environmental conditions that influence the regeneration of injured axons. The presence of myelin inhibitors and glial scar, lack of neurotrophic factors, and inflammation mediated by injury are regarded as these extrinsic factors. Extrinsic factors need to trigger the intracellular signals to exert inhibitory effect. Proper regulation of these intracellular signals has been shown to be beneficial to ON regeneration. Intrinsic factors of RGCs are the pivotal reasons that inhibit ON regeneration and are closely linked with extrinsic factors. Intracellular cyclic adenosine monophosphate (cAMP) and calcium levels affect axon guidance and growth cone response to guidance molecules. Many genes, such as Bcl-2, PTEN, and mTOR, are crucial in cell proliferation, axon guidance, and growth during development, and play important roles in the regeneration and extension of RGC axons. With transgenic mice and related gene regulations, robust regeneration of RGC axons has been observed after ON injury in laboratories. Although various means of experimental treatments such as cell transplantation and gene therapy have achieved significant progress in neuronal survival, axonal regeneration, and restoration of the visual function after ON injury, many unresolved scientific problems still exist for their clinical applications. Therefore, we still need to overcome hurdles before developing effective therapy to treat optic neuropathy diseases in patients.published_or_final_versio

KACC: An identification and characterization for microbial resources in Korea

Korean Agricultural Culture Collection (KACC) is an authorized organizer and the official depository for microbial resources in Korea. The KACC has developed a web-based database system to provide integrated information about microbial resources. It includes not only simple text information onindividual microbe but also morphological images and DNA sequence data for the strain. The KACC now provides the characterization information which maintains 7,433 cultures of microorganisms including 2,687 strains of bacteria, 3535 fungi, 476 actinomycetes, 64 yeasts, and 671 others (mushrooms, gene clones, etc)

A Reaction Between High Mn-High Al Steel and CaO-SiO2-Type Molten Mold Flux: Part I. Composition Evolution in Molten Mold Flux

In order to elucidate the reaction mechanism between high Mn-high Al steel such as twin-induced plasticity steel and molten mold flux composed mainly of CaO-SiO2 during continuous casting process, a series of laboratory-scale experiments were carried out in the present study. Molten steel and molten flux were brought to react in a refractory crucible in a temperature range between 1713 K to 1823 K (1440 A degrees C to 1550 A degrees C) and composition evolution in the steel and the flux was analyzed using inductively coupled plasma atomic emission spectroscopy, X-ray fluorescence, and electron probe microanalysis. The amount of SiO2 in the flux was significantly reduced by Al in the steelthus, Al2O3 was accumulated in the flux as a result of a chemical reaction, 4[Al] + 3(SiO2) = 3[Si] + 2(Al2O3). In order to find a major factor which governs the reaction, a number of factors ((pct CaO/pct SiO2), (pct Al2O3), [pct Al], [pct Si], and temperature) were varied in the experiments. It was found that the above chemical reaction was mostly governed by [pct Al] in the molten steel. Temperature had a mild effect on the reaction. On the other hand, (pct CaO/pct SiO2), (pct Al2O3), and [pct Si] did not show any noticeable effect on the reaction. Apart from the above reaction, the following reactions are also thought to happen simultaneously: 2[Mn] + (SiO2) = [Si] + 2(MnO) and 2[Fe] + (SiO2) = [Si] + 2(FeO). These oxide components were subsequently reduced by Al in the molten steel. Na2O in the molten flux was gradually decreased and the decrease was accelerated by increasing [pct Al] and temperature. Possible reactions affecting the Al2O3 accumulation are summarized.ope

Ferromagnetic properties of Zn1-xMnxO epitaxial thin films

We report on ferromagnetic characteristics of Zn1-xMnxO (x=0.1 and 0.3) thin films grown on Al2O3(00.1) substrates using laser molecular-beam epitaxy. By increasing the Mn content, the films exhibited increases in both the c-axis lattice constant and fundamental band gap energy. The Curie temperature obtained from temperature-dependent magnetization curves was 45 K for the film with x=0.3, depending on the Mn composition in the films. The remanent magnetization and coercive field of Zn0.9Mn0.1O at 5 K were 0.9 emu/g and 300 Oe, respectively. For Zn0.7Mn0.3O, the remanent magnetization at 5 K increased to 3.4 emu/g. (C) 2002 American Institute of Physics.open11509532sciescopu

Ubiquitous Graphene Electronics on Scotch Tape

We report a novel concept of graphene transistors on Scotch tape for use in ubiquitous electronic systems. Unlike common plastic substrates such as polyimide and polyethylene terephthalate, the Scotch tape substrate is easily attached onto various objects such as banknotes, curved surfaces, and human skin, which implies potential applications wherein electronics can be placed in any desired position. Furthermore, the soft Scotch tape serves as an attractive substrate for flexible/foldable electronics that can be significantly bent, or even crumpled. We found that the adhesive layer of the tape with a relatively low shear modulus relaxes the strain when subjected to bending. The capacitance of the gate dielectric made of oxidized aluminum oxide was 1.5 mu F cm(-2), so that a supply voltage of only 2.5 V was sufficient to operate the devices. As-fabricated graphene transistors on Scotch tape exhibited high electron mobility of 1326 (+/- 155) cm(2) V-1 s(-1); the transistors still showed high mobility of 1254 (+/- 478) cm(2) V-1 s(-1) even after they were crumpled.open1133Ysciescopu

Contribution of the cyclic nucleotide gated channel subunit, CNG-3, to olfactory plasticity in Caenorhabditis elegans.

In Caenorhabditis elegans, the AWC neurons are thought to deploy a cGMP signaling cascade in the detection of and response to AWC sensed odors. Prolonged exposure to an AWC sensed odor in the absence of food leads to reversible decreases in the animal's attraction to that odor. This adaptation exhibits two stages referred to as short-term and long-term adaptation. Previously, the protein kinase G (PKG), EGL-4/PKG-1, was shown necessary for both stages of adaptation and phosphorylation of its target, the beta-type cyclic nucleotide gated (CNG) channel subunit, TAX-2, was implicated in the short term stage. Here we uncover a novel role for the CNG channel subunit, CNG-3, in short term adaptation. We demonstrate that CNG-3 is required in the AWC for adaptation to short (thirty minute) exposures of odor, and contains a candidate PKG phosphorylation site required to tune odor sensitivity. We also provide in vivo data suggesting that CNG-3 forms a complex with both TAX-2 and TAX-4 CNG channel subunits in AWC. Finally, we examine the physiology of different CNG channel subunit combinations

Toxicity assessment of modified Cry1Ac1 proteins and genetically modified insect-resistant Agb0101 rice

Insect-resistant Agb0101 rice was recently developed by modifying the cry1ac1 gene by changing codon usage changes relative to the native truncated cry1ac1 gene. To assess the toxicity of genetically modified Agb0101 rice, we conducted bioinfomational comparisons of the amino acid sequences that are not similar to known toxic proteins. Sufficient quantities of mCry1Ac1 protein were produced in Escherichia coli for in vitro evaluation and animal study. We compared the amino acid sequences and molecular mass. There have the same amino acid sequences and molecular masses after purifying the modified Cry1Ac1 (mCry1Ac1) protein from highly expressed bacteria and genetically modified rice were identical. We also investigated the acute and 90-days oral toxicities. No adverse effects were observed in mice following acute oral exposure to 2,000 mg/ kg body weight mCry1Ac1 protein of body weight and 90 days oral exposure to Agb0101. These results indicate that mCry1Ac1 proteins and Agb0101 rice demonstrate no adverse effects in these tests when applied via gavage and feed, respectively.Key words: Modified Cry1Ac1, food safety assessment, toxicity, insect- resistant rice Agb0101

Improved genome editing in human cell lines using the CRISPR method

The Cas9/CRISPR system has become a popular choice for genome editing. In this system, binding of a single guide (sg) RNA to a cognate genomic sequence enables the Cas9 nuclease to induce a double-strand break at that locus. This break is next repaired by an error-prone mechanism, leading to mutation and gene disruption. In this study we describe a range of refinements of the method, including stable cell lines expressing Cas9, and a PCR based protocol for the generation of the sgRNA. We also describe a simple methodology that allows both elimination of Cas9 from cells after gene disruption and re-introduction of the disrupted gene. This advance enables easy assessment of the off target effects associated with gene disruption, as well as phenotype-based structure-function analysis. In our study, we used the Fan1 DNA repair gene as control in these experiments. Cas9/CRISPR-mediated Fan1 disruption occurred at frequencies of around 29%, and resulted in the anticipated spectrum of genotoxin hypersensitivity, which was rescued by re-introduction of Fan1

Redefining the Septal L-Strut in Septal Surgery

In septal surgery, the surgeon preserves the L-strut, the portion anterior to a vertical line drawn from the rhinion to the anterior nasal spine (ANS) and at least a 1-cm width of the dorsal and caudal septal segment, to decrease the potential for loss of the tip and dorsal nasal support. However, nasal tip collapse and saddle deformities occur occasionally. We utilized a mechanical approach to determine the safe width size for the L-strut in contact with the maxillary crest. Five L-strut models were designed based on computed tomography data (80 patients) and previous studies (55 patients). All L-strut models connected the perpendicular plate of the ethmoid bone (PPE) and the maxillary crest and were assumed to be fixed to the PPE and maxillary crest. An approximated daily load was applied to the dorsal portion of the L-strut. Finite element analyses were performed to compare the stress, strain, and displacement distribution of all L-strut models. According to the differences in the contact area between the caudal L-strut and maxillary crest, there are significant differences in terms of the stress, strain, and displacement distribution in the L-strut. High stresses occurred at the inner corner of the L-strut when 60 - 100% of the strut was in contact with the maxillary crest. High stresses also occurred at the inferior portion of the caudal L-strut when 20 - 40% of the caudal strut was in contact with maxillary crest. We conclude that it is important to preserve the 1-cm width L-strut caudal segment, which corresponds to the portion posterior to a vertical line drawn from the rhinion to the ANS. In particular, we must maintain more than 40% of the contact area between the L-strut and the maxillary crest when the septal cartilage in the caudal portion of the L-strut is harvested.ope