The Reverse Glyoxylate Shunt

Acetyl-CoA is an essential intermediate in a lot biofuel and biochemical productions. In hope to eliminate the carbon loss steps in producing acetyl-CoA from pyruvate, we sought to design and implement an alternative pathway in E. coli for more efficient carbon usage and for the reduction of CO2 emission during the biochemical production process. In nature, many pathways exist as reverse counterparts of each other, such glycolysis and gluconeogenesis, pentose phosphate pathways and the Calvin-Benson-Bassham cycle, the tricarboxylic acid cycle and the reductive tricarboxylic acid cycle, etc. Inspired by the idea, we designed a reverse glyoxylate shunt to bypass the pyruvate decarboxylating step in order to conserve carbon for the production of acetyl-CoA. In this work, we designed two similar pathways based on a fully or partially reverse glyoxylate shunt for the conversion of carbon from either C4 or C3 into C2. The driving force principle in metabolic engineering was employed to reverse the glyoxylate shunt by overexpressing ATPdependent enzymes. In the first reverse glyoxylate shunt (rGS-1), we built the pathway replacing enzymes that are intrinsically irreversible with ATP-dependent ones. By optimizing branch point in which the native glutamate metabolism drains the intermediate, isocitrate, from our pathway, we demonstrated the conversion of malate and succinate into OAA and acetyl-CoA, essentially the conversion of a molecule of C4 into a C2 molecule in an aspartate auxotroph. As for second reverse glyoxylate shunt (rGS-2), we built upon the rGS-1 with the addition of the glyoxylate degradation pathway for recycling glyoxylate back to the C3 molecules. We improved malate thiokinase and malyl-CoA lyase coupled activities and showed growth rescues in two strains, including enhanced growth rate in an acetyl-CoA auxotroph. The two reverse glyoxylate shunts posed potential solution to the inefficient carbon usage and with further development of CO2 fixation enzymes, are capable of being a building block of a CO2 fixation pathway

Competition and demand in the electricity industry

In the past and current decades, there has been increasing number of privatization of statutory boards both abroad and locally. This has created much discussion on the topic in the government, business, academic as well as the media circles in several countries such as Great Britain, United States and France.ACCOUNTANC

Aggressive SiGe Channel Gate Stack Scaling by Remote Oxygen Scavenging: Gate-First pFET Performance and Reliability Remotely M-doped TiN La-based cap O Biaxially strained SiGe Remotely M-doped TiN Al 2 O 3 cap (optional) O Si nFET pFET Si cap (optional) S

We demonstrate that aggressive gate dielectric scaling in hafnium-based high-k/metal gate p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs) with biaxially strained silicon germanium channels can be achieved in gate-first integration via remote interfacial SiO 2 scavenging by metal-doped titanium nitride gates. An inversion thickness of 0.86 nm is reached, corresponding to an equivalent oxide thickness (EOT) of 0.45-0.5 nm. Interlayer-scaling-induced threshold voltage increase and hole mobility reduction are studied in detail. We further establish an exponential interlayer thickness dependence of negative bias temperature instability (NBTI). Previously shown to be effective for nFETs, remote oxygen scavenging is an attractive scaling option for dual-channel CMOS. © 2012 The Electrochemical Society. [DOI: 10.1149/2.005302ssl] All rights reserved. Biaxially strained silicon germanium channels (cSiGe) epitaxially grown on silicon have recently received much attention for their ability to reduce the often undesirably high threshold voltage (V t ) of hafnium-based high-k/metal gate (HKMG) p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs or pFETs). 1-5 They are typically combined with Si channel nFETs. In order for such dual-channel complementary MOS (CMOS) to be a viable option for future technology nodes requiring continued reductions in equivalent oxide thickness (EOT), simultaneous gate dielectric scaling for both nFETs and pFETs has to be achieved. We have previously shown that aggressive gate dielectric scaling in Si channel nFETs can be achieved in gate-first integration via remote interfacial SiO 2 layer ('interlayer') scavenging by TiN gate electrodes doped with high-oxygen-affinity metals. 6-8 Herein, we demonstrate that the same approach is viable for SiGe channel pFETs. We then use this scavenging approach to establish quantitative guidelines on interlayer-scaling-induced pFET V t increase, hole mobility reduction, and negative bias temperature instability (NBTI) degradation. Experimental Planar transistors were fabricated in a gate-first process flow, as follows ( • C rapid thermal anneal (RTA) for dopant activation, salicide source/drain metallization, and a final forming gas anneal (FGA) or special cSiGe anneal. 1 While we report data from planar devices, given a sufficiently conformal gate electrode the remote oxygen scavenging approach is expected to be viable for FinFET or Tri-Gate devices as well. Results and Discussion Exemplary transmission electron microscopy (TEM) images of Sicapped low-Ge-content cSiGe pFETs with Al 2 O 3 cap z E-mail: [email protected] capacitance equivalent thickness in inversion ('inversion thickness', T inv ) from 1.41 to 0.86 nm Comparing cSiGe devices with the same Ge content but different Si cap thickness (regular, thin, none) at a given amount of M doping, the T inv data in It has been reported that T inv of Si-capped SiGe channel transistors increases with increasing Si cap thickness, due to the formation of a SiGe quantum well for holes, i.e. a buried channel. 2,9 Our data show no such T inv increase from thin to regular Si caps Finally, since Si caps probably can only prevent regrowth while they are still intact, we note that interlayer regrowth on uncappe

The High Expression of Legumain in Canine Neoplasms: A Retrospective Analysis of 100 Cases

Legumain, a novel asparaginyl endopeptidase, has been observed to be overexpressed in several types of human solid tumors. Elevated levels of legumain are found in human cancers, and this oncoprotein may facilitate tumor invasion and metastasis when overexpressed. These findings suggest that legumain plays a malignant role in cancer biology. However, currently, no publications have identified the role of legumain in the development of canine cancers. The present study first compared the expression patterns of legumain in paraffin-embedded canine tumor tissues, with those of normal tissues, by immunohistochemistry. A total of 100 canine tumor samples, including mast cell tumors, soft tissue sarcoma, hemangiosarcoma, lymphoma, mammary gland carcinoma, hepatoid gland tumor, squamous cell carcinoma, trichoblastoma, and melanoma were evaluated. Compared with the normal tissues, all tumor samples displayed high intensities of legumain expression. Mesenchymal-type tumors displayed immunoreactivity for legumain, with an average expression of 40.07% ± 1.70%, which was significantly lower than those of epithelial tumors and other types of tumors, which had median expressions of 49.12% ± 1.75% and 47.35% ± 2.71%, respectively (p < 0.05). These findings indicate that legumain has a high potential to be a candidate for distinguishing tumors from normal tissues. Although further studies on a larger number of cases are necessary to clarify the clinical application of legumain, the overexpression patterns of legumain in canine tumor tissues are reported, for the first time, in this study

Developing novel liquid crystal technologies for display and photonic applications

Modern liquid crystal displays (LCDs) require novel technologies, such as new alignment methods to eliminate alignment layers, fast response and long operation time. To this end, we report an overview of recent efforts in LCD technologies devoted to realize more display modes having no alignment layer, faster switching time and low battery consumption. In particular, we overview recent advances on the liquid crystals (LCs) alignment for display applications, which includes superfine nanostructures, polymeric microchannels and polymer stabilized LCs. Furthermore, we analyze the main optical and electro-optical properties of new generation LCDs displays addressing a particular attention to LCs blue phase hosting gold nanoparticles. Moreover, we focus on the progress of electrofluidic displays, which demonstrates characteristics that are similar to LCDs, with attention on various pixel designs, operation principles and possible future trends of the technology