ZnO composite nanolayer with mobility edge quantization for multi-value logic transistors.

A quantum confined transport based on a zinc oxide composite nanolayer that has conducting states with mobility edge quantization is proposed and was applied to develop multi-value logic transistors with stable intermediate states. A composite nanolayer with zinc oxide quantum dots embedded in amorphous zinc oxide domains generated quantized conducting states at the mobility edge, which we refer to as "mobility edge quantization". The unique quantized conducting state effectively restricted the occupied number of carriers due to its low density of states, which enable current saturation. Multi-value logic transistors were realized by applying a hybrid superlattice consisting of zinc oxide composite nanolayers and organic barriers as channels in the transistor. The superlattice channels produced multiple states due to current saturation of the quantized conducting state in the composite nanolayers. Our multi-value transistors exhibited excellent performance characteristics, stable and reliable operation with no current fluctuation, and adjustable multi-level states.

Single-Crystal Poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)- alt-[1,2,5]thiadiazolo[3,4- c]pyridine] Nanowires with Ultrahigh Mobility.

We fabricated single-crystal poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']-dithiophen-2-yl)- alt-[1,2,5]thiadiazolo-[3,4- c]pyridine] (PCDTPT) nanowires with ultrahigh mobility using a liquid-bridge-mediated nanotransfer molding method. The structural analysis of the single-crystal PCDTPT nanowires reveals that PCDTPT crystals have a triclinic structure, and the nanowires grow parallel to PCDTPT backbone chains, which provide important insights into its intrinsic charge transport. The single-crystal PCDTPT nanowire exhibits a superior charge carrier mobility of 72.94 ± 18.02 cm2 V-1 s-1 (maximum mobility up to 92.64 cm2 V-1 s-1), which is a record high value among conjugated polymers to date. In the single-crystal PCDTPT nanowire, the backbone chains in the linear structure along the nanowire growth axis lead to strong backbone delocalization, resulting in highly conductive polymer backbones and a drastic increase in charge carrier mobility. In addition, the single-crystal PCDTPT nanowire shows good environmental stability under air conditions compared to small-molecule organic semiconductors.

Ultra Gas-Proof Polymer Hybrid Thin Layer.

Hermetic sealing is an important technology for isolating and protecting air-sensitive materials and is key in the development of foldable and stretchable electronic devices. Here we report an ultra gas-proof polymer hybrid thin layer prepared by filling the free volume of the polymer with Al2O3 using gas-phase atomic layer infiltration. The high-density polymer-inorganic hybrid shows extremely low gas transmission rate, below the detection limit of the Ca corrosion test (water vapor transmission rate <10-7 g m-2 day-1). Furthermore, because of the remarkable nanometer-scale thinness of the complete polymer-inorganic hybrid, it is highly flexible, which makes it useful for hermetic sealing of stretchable and foldable devices.

Comparative efficacy and safety profile of amlodipine 5 mg/losartan 50 mg fixed-dose combination and amlodipine 10 mg monotherapy in hypertensive patients who respond poorly to amlodipine 5 mg monotherapy: an 8-week, multicenter, randomized, double-blind phase III noninferiority study.

BACKGROUND: The number of hypertensive patients achieving treatment targets is not ideal with therapies that engage a single mechanism of action, and combination therapies using different mechanisms of action can increase drug efficacy in a synergistic way. OBJECTIVE: This noninferiority study compared the clinical efficacy and safety profile of fixed-dose combination of amlodipine/losartan 5/50 mg and amlodipine 10 mg monotherapy in essential hypertensive patients who respond poorly to amlodipine 5 mg monotherapy. METHODS: This was a double-blind, multicenter, randomized trial of hypertensive patients (N = 185) aged ≥18 years taking amlodipine 5 mg during the run-in treatment period but failed to achieve sitting diastolic blood pressure (DBP) <90 mm Hg. After randomization into the amlodipine/losartan 5/50 mg fixed-dose combination group (n = 92) and the amlodipine 10 mg monotherapy group (n = 93), treatment was maintained without dose escalation for 8 weeks. The noninferiority margin was prespecified as 4 mm Hg after 8 weeks of treatment for the difference of the average change in DBP between treatments. The primary efficacy evaluation of noninferiority was tested using a confidence interval approach with a 97.5% 1-sided lower confidence limit using the average difference in DBP measured at baseline and 8 weeks. RESULTS: After 8 weeks, the DBP of both groups decreased from baseline by 8.9 (6.1) and 9.4 (7.5) mm Hg, respectively (difference = -0.5 [6.9] mm Hg, 95% CI: -2.5 to 1.5). Secondary end points of reductions in DBP after 4 weeks (-8.1 [6.7] vs -9.9 [7.3] mm Hg, difference = -1.8 mm Hg, 95% CI: -3.9 to 0.2) and sitting systolic blood pressure after 4 (-10.2 [11.8] vs -12.8 [10.2] mm Hg, difference = -2.6 mm Hg, 95% CI: -5.9 to 0.6) and 8 weeks (-12.2 [11.0] vs -13.4 [11.3] mm Hg, difference = -1.2 mmHg, 95% CI: -4.4 to 2.1) were comparable between the 2 treatment groups. There were 38 adverse events in 20 patients (21.7%) in the amlodipine/losartan 5/50 mg fixed-dose combination group and 31 in 24 patients (26.1%) in the amlodipine 10 mg monotherapy group; most were mild. There were 7 adverse events in 6 patients (6.5%) related to treatment in the fixed-dose combination group and 13 in 10 patients (10.9%) in the monotherapy group (P = 0.30). CONCLUSIONS: Fixed-dose combination amlodipine/losartan 5/50 mg was not inferior in terms of reductions in DBP after 8 weeks of treatment and had comparable safety profile to amlodipine 10 mg in patients who did not respond to amlodipine 5 mg monotherapy. ClinicalTrials.gov identifier: NCT00940667.

Electromyographic activity of the masseter muscle after radiofrequency therapy in an animal model.

PURPOSE: The purpose of this study was to examine changes in the electromyographic (EMG) activity of the masseter muscle after radiofrequency therapy (RF). METHODS: Twelve rabbits were used in this study: four in each group according to the number of RF applications. Preoperative EMG in the masseter muscle was used as the control. EMG was recorded at 1, 2, 3, and 4 weeks after RF in each rabbit. The recorded data were analyzed in terms of voltage and frequency, and changes in recorded variables were compared among the groups. The relative activity in peak voltage, root mean square of the action potential, area of voltage, and area of frequency were investigated. RESULTS: When compared to preoperative values, the variables at 3 or 4 weeks after RF application were significantly different in the single and quadruple therapy groups (P<0.05). There was no significant difference in the other groups (P>0.05). When the samples were regrouped as two groups like small number of application group (one or two point) and large number of application group (three or four points), the area of voltage and the area of frequency were significantly different between the groups at 4 weeks (P<0.05). CONCLUSIONS: Masseter muscle activity after RF was significantly decreased compared to its preoperative state. The decreased activity was related to the number of applications and time elapsed after RF.

The change in dimension of the masseter muscle in rabbits after radiofrequency therapy.

PURPOSE: The objective of this study was to evaluate the change in muscle dimension after administering radiofrequency (RF) therapy. MATERIALS AND METHODS: This study used 6 male New Zealand rabbits. Groups were divided by number of applications of RF (eg, 1 to 4 points). The dimension of the masseter muscle was measured using a computerized tomogram scan before operation, and at 1, 2, 3, and 4 weeks after RF therapy was administered under the same conditions. Two horizontal cuts were selected for measurement. RESULTS: The size of the measured areas for each group at 1 week after RF therapy was significantly increased compared with the preoperative value (P< .05). When the measurements of each group at 3 and 4 weeks after RF therapy were compared with the preoperative value, they were significantly decreased (P< .05). The dimensional change was significantly different among groups at 1 and 3 weeks post RF therapy (P< .05). The swelling at 1 week after RF therapy was increased in terms of the number of RF applications. The ratio of dimension was decreased at 3 weeks after RF therapy in terms of the number of RF applications. CONCLUSION: There was an increase in muscle dimension because of swelling in the early stages of RF therapy. However, this dimension decreased at 3 weeks post-RF administration compared with the preoperative value. Therefore, it can be concluded that the change in the masseter muscle dimension was dependent on the number of RF applications.

The solution structure of ribosomal protein S17E from Methanobacterium thermoautotrophicum: a structural homolog of the FF domain.

The ribosomal protein S17E from the archaeon Methanobacterium thermoautotrophicum is a component of the 30S ribosomal subunit. S17E is a 62-residue protein conserved in archaea and eukaryotes and has no counterparts in bacteria. Mammalian S17E is a phosphoprotein component of eukaryotic ribosomes. Archaeal S17E proteins range from 59 to 79 amino acids, and are about half the length of the eukaryotic homologs which have an additional C-terminal region. Here we report the three-dimensional solution structure of S17E. S17E folds into a small three-helix bundle strikingly similar to the FF domain of human HYPA/FBP11, a novel phosphopeptide-binding fold. S17E bears a conserved positively charged surface acting as a robust scaffold for molecular recognition. The structure of M. thermoautotrophicum S17E provides a template for homology modeling of eukaryotic S17E proteins in the family.

Lys296 and Arg299 residues in the C-terminus of MD-ACO1 are essential for a 1-aminocyclopropane-1-carboxylate oxidase enzyme activity.

The 1-aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the last step in the biosynthesis of ethylene from ACC in higher plants. The complex structure of ACC oxidase/Fe(2+)/H(2)O derived from Petunia hybrida has recently been established by X-ray crystallography and it provides a vast structural information for ACC oxidase. Our mutagenesis study shows that both Lys296 and Arg299 residues in the C-terminal helix play important roles in enzyme activity. Both K296R and R299K mutant proteins retain only 30-15% of their enzyme activities with respect to that of the wild-type, implying that the positive charges of C-terminal residues are involved in enzymatic reaction. Furthermore, the sequence alignment of ACC oxidases from 24 different species indicates an existence of the exclusively conserved motif (Lys296-Glu301) especially in the C-terminus. The structure model based on our findings suggests that the positive-charged surface in the C-terminal helix of the ACC oxidase could be a major stabilizer in the spatial arrangement of reactants and that the positive-charge network between the active site and C-terminus is critical for ACC oxidase activity.

Solution structure of YKR049C, a putative redox protein from Saccharomyces cerevisiae.

YKR049C is a mitochondrial protein in Saccharomyces cerevisiae that is conserved among yeast species, including Candida albicans. However, no biological function for YKR049C has been ascribed based on its primary sequence information. In the present study, NMR spectroscopy was used to determine the putative biological function of YKR049C based on its solution structure. YKR049C shows a well-defined thioredoxin fold with a unique insertion of helices between two beta-strands. The central beta-sheet divides the protein into two parts; a unique face and a conserved face. The 'unique face' is located between beta2 and beta3. Interestingly, the sequences most conserved among YKR049C families are found on this 'unique face', which incorporates L109 to E114. The side chains of these conserved residues interact with residues on the helical region with a stretch of hydrophobic surface. A putative active site composed by two short helices and a single Cys97 was also well observed. Our findings suggest that YKR049C is a redox protein with a thioredoxin fold containing a single active cysteine.

Exploring protein fold space by secondary structure prediction using data distribution method on Grid platform.

MOTIVATION: Since the newly developed Grid platform has been considered as a powerful tool to share resources in the Internet environment, it is of interest to demonstrate an efficient methodology to process massive biological data on the Grid environments at a low cost. This paper presents an efficient and economical method based on a Grid platform to predict secondary structures of all proteins in a given organism, which normally requires a long computation time through sequential execution, by means of processing a large amount of protein sequence data simultaneously. From the prediction results, a genome scale protein fold space can be pursued. RESULTS: Using the improved Grid platform, the secondary structure prediction on genomic scale and protein topology derived from the new scoring scheme for four different model proteomes was presented. This protein fold space was compared with structures from the Protein Data Bank, database and it showed similarly aligned distribution. Therefore, the fold space approach based on this new scoring scheme could be a guideline for predicting a folding family in a given organism.

Solution structure of a novel calcium binding protein, MTH1880, from Methanobacterium thermoautotrophicum.

MTH1880 is a hypothetical protein from Methanobacterium thermoautotrophicum, a target organism of structural genomics. The solution structure determined by NMR spectroscopy demonstrates a typical alpha + beta-fold found in many proteins with different functions. The molecular surface of the protein reveals a small, highly acidic pocket comprising loop B (Asp36, Asp37, Asp38), the end of beta2 (Glu39), and loop D (Ser57, Ser58, Ser61), indicating that the protein would have a possible cation binding site. The NMR resonances of several amino acids within the acidic binding pocket in MTH1880, shifted upon addition of calcium ion. This calcium binding motif and overall topology of MTH1880 differ from those of other calcium binding proteins. MTH1880 did not show a calcium-induced conformational change typical of calcium sensor proteins. Therefore, we propose that the MTH1880 protein contains a novel motif for calcium-specific binding, and may function as a calcium buffering protein.

Structure-based functional discovery of proteins: structural proteomics.

The discovery of biochemical and cellular functions of unannotated gene products begins with a database search of proteins with structure/sequence homologues based on known genes. Very recently, a number of frontier groups in structural biology proposed a new paradigm to predict biological functions of an unknown protein on the basis of its three-dimensional structure on a genomic scale. Structural proteomics (genomics), a research area for structure-based functional discovery, aims to complete the protein-folding universe of all gene products in a cell. It would lead us to a complete understanding of a living organism from protein structure. Two major complementary experimental techniques, X-ray crystallography and NMR spectroscopy, combined with recently developed high throughput methods have played a central role in structural proteomics research; however, an integration of these methodologies together with comparative modeling and electron microscopy would speed up the goal for completing a full dictionary of protein folding space in the near future.

Solution structure of ribosomal protein S28E from Methanobacterium thermoautotrophicum.

The ribosomal protein S28E from the archaeon Methanobacterium thermoautotrophicum is a component of the 30S ribosomal subunit. Sequence homologs of S28E are found only in archaea and eukaryotes. Here we report the three-dimensional solution structure of S28E by NMR spectroscopy. S28E contains a globular region and a long C-terminal tail protruding from the core. The globular region consists of four antiparallel beta-strands that are arranged in a Greek-key topology. Unique features of S28E include an extended loop L2-3 that folds back onto the protein and a 12-residue charged C-terminal tail with no regular secondary structure and greater flexibility relative to the rest of the protein. The structural and surface resemblance to OB-fold family of proteins and the presence of highly conserved basic residues suggest that S28E may bind to RNA. A broad positively charged surface extending over one side of the beta-barrel and into the flexible C terminus may present a putative binding site for RNA.