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Growth, structural, magnetic, and spin transport properties of epitaxial scandium-substituted terbium iron garnet (TbScIG) thin films on gadolinium gallium garnet [GGG, (111) orientation] substrates are reported as a function of Sc content. The films are epitaxial on GGG without strain relaxation up to a thickness of 90 nm and exhibit perpendicular magnetic anisotropy. Sc, a nonmagnetic cation, occupies up to 40% of the octahedral Fe sites. Increasing Sc lowers the compensation temperature and Curie temperature and increases the room-temperature saturation magnetization from 37 kA/m for ${\mathrm{Tb}}_{2.8}{\mathrm{Fe}}_{5.2}{\mathrm{O}}_{12}$ to 59 kA/m for ${\mathrm{Tb}}_{2.8}{\mathrm{Sc}}_{0.8}{\mathrm{Fe}}_{4.4}{\mathrm{O}}_{12}$. Anomalous Hall effect-like spin Hall magnetoresistance measurements were performed to determine the effect of scandium content on spin mixing conductance of the TbScIG|Pt interface. The spin mixing conductance increased significantly with an increase in Sc content, consistent with a dependence of spin transport on the net Fe magnetization instead of the total magnetization of the garnet.

Conversion of free fatty acids into monoacylglycerol gives rise to new structural properties, particularly amphipathic property. Therefore, monoacylglycerols are widely used in pharmaceutical and food industries and are also reported to facilitate better absorption into the human body. A functional fatty acid when transformed into a monoacylglycerol will possibly conserve both the original functionality and amphipathic property. The compound 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was generated from oleic acid by Pseudomonas aeruginosa PR3 and was known to contain antimicrobial activities against a broad range of food-borne and plant pathogenic bacteria. Here, we attempted to convert DOD into its monoacylglycerol form using lipase for producing an amphipathic antibacterial agent. Consequently, the monoacylglycerol of DOD (DOD-MAG) was successfully produced by coincubating DOD, glycerol, and lipase at 30 °C. The maximum conversion yield reached 70% after 12 h of incubation. Antibacterial activity of DOD-MAG was enhanced by 8 times from the original activity of DOD against food-borne bacteria.

Aims Purification of porcine circovirus type 2 (PCV2) using Gram-positive enhancer matrix (GEM) surface display technology and immunogenicity evaluation of the purified antigen. Methods and results A recombinant bifunctional protein containing a protein anchor domain and a 'virus anchor' domain was designed as a protein linker (PL) between PCV2 and GEM particles. By incubating with PL and GEM particles sequentially, PCV2 could be purified and enriched through a simple centrifugation process with GEM surface display technology. Our data showed that one unit (2·5 × 109 particles) of GEM particles with 80 μg PL could purify 100 ml of PCV2-containing culture supernatant (viral titre: 106·5 TCID50 per ml-1 ) with a recovery rate up to 99·6%. The impurity removal efficiency of this method, calculated according to decreased total protein content during purification, was approximately 98%. Furthermore, in vivo experimentation showed that piglets immunized with purified PCV2 could elicit strong immune responses to prevent against PCV2 infection. Conclusion Porcine circovirus type 2 could be efficiently purified and enriched with GEM display technology via a crucial PL, and the purified PCV2 could elicit effective immune responses against PCV2 infection. Significance and impact of the study The GEM-based purification method established here is cost-efficient and high-throughput, and may represent a promising large-scale purification method for PCV2 vaccine production.

Soy-polyol oils (oxygenated acylglycerols) are important starting materials for the manufacture of polymers such as polyurethane. We reported methods for microbial screening and production of polyol oils from soybean oil through bioprocessing (Hou and Lin, 2013). Using this screening method, we screened 650 cultures isolated and found 50 cultures were positive for converting soybean oil to polyol oil. The two most active of these positive cultures are Acinetobacter haemolyticus A01-35 and Pseudomonas aeruginosa E03-12 (Hou et al., 2015). The polyol oil produced by strain A01-35 was a mixture of hydroxy fatty acids-containing DAG. Strain E03-12 produced more polyol oil than strain A01-35 and its product contains both hydroxy fatty acids-containing DAG and TAG. We employed one-factor-at-a-time method to develop an optimized culture medium composition and reaction conditions for polyol oils production from soybean oil by strain E03-12. We found that among the different carbon sources studied, glucose at 12.5 g/L is the best. A combination of both tryptone at 12.5 g/L and yeast extract at 10 g/L serves as the best nitrogen source. Both iron and magnesium were studied for the effect of metal on the production of polyol oils. MgSO4 7H2O at 0.75 g/L and FeSO4 7H2O at 0.30 g/L produced the best result. Using this optimum medium composition, the best pH for the polyol oils production was found at 6.8. The optimum temperature for polyol oil production is 28 C. The optimum substrate concentration is 183 mg/30 mL. In the time course studies with these optimum reaction conditions, the best yield is 18.5 mg/30 mL at 48 h. Longer incubation time leads to the decrease in product polyol oils and increase in DAGs. The information obtained from this study is important for developing scale up production of polyol oils directly from soybean oil.

Cell-free synthesis has been adopted in the bioconversion process due to its known advantages, such as fast production rate, high product content, and no substrate/product inhibition effect. In this study, the cell-free supernatant of Pseudomonas aeruginosa was used to improve the production of 7,10‐dihydroxy‐8(E)‐octadecenoic acid (DOD) from oleic acid. DOD production using cell-free supernatant demonstrated reduction in bioconversion duration and higher product concentration than conventional method using whole cell culture. The maximum DOD concentration (6.41 g/L) was obtained after 36 h of biotransformation using 1 % v/v oleic acid as a substrate with a productivity of 0.178 g/L/h and a yield of 74.8 %. DOD concentration, productivity, and yield using cell-free supernatant were 2.12, 7.12, and 2.22 times higher, respectively, than using the conventional whole cell culture method. Of the carbon and nitrogen sources used in pre-culture, galactose and sodium glutamate along with diammonium phosphate were found to be the most effective for DOD production. An incubation temperature of 27 °C and pH 8.0 were found to be most favorable for DOD production. In addition, sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis demonstrated the presence of enzymes related to DOD production in the cell-free supernatant, which was substantiated by performing DOD production experiment using the supernatant enzymes extracted from protein gel bands with oleic acid as a substrate. To the best of our knowledge, this is the first report on DOD production using a cell-free supernatant and verifying the existence of the relevant enzymes in the cell-free supernatant. Compared to whole cell process, cell-free DOD production holds several advantages, including higher DOD productivity which could be beneficial for large-scale production.

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) infections with multi-drug resistance needs effective and alternative control strategies. In this study we investigated the adjuvant effect of a novel furan fatty acid, 7,10-epoxyoctadeca-7,9-dienoic acid (7,10-EODA) against multidrug-resistant S. aureus (MDRSA) strain 01ST001 by disc diffusion, checker board and time kill assays. Further the membrane targeting action of 7,10-EODA was investigated by spectroscopic and confocal microscopic studies. 7,10-EODA exerted synergistic activity along with β-lactam antibiotics against all clinical MRSA strains, with a mean fractional inhibitory concentration index below 0.5. In time-kill kinetic study, combination of 7,10-EODA with oxacillin, ampicillin, and penicillin resulted in 3.8–4.2 log10 reduction in the viable counts of MDRSA 01ST001. Further, 7,10-EODA dose dependently altered the membrane integrity (p

Edible Philippine mushrooms including Ganoderma lucidum have many health benefits. We have recently reported the identities and the contents of 77 molecular species of acylglycerols containing hydroxy fatty acids (HFA) in this mushroom. The structures of these HFA were proposed using the electrospray ionization mass spectrometry of the lithium adducts of acylglycerols in the HPLC fractions of the lipid extract. The proposed structures of the HFA were OH1319:110, OH1319:114, 2OH11,1218:0, 2OH11,1218:19, 2OH11,1218:29,13, 3OH11,12,1318:19 and 3OH11,12,1318:114. The locations of the hydroxyl groups and double bonds were near the middle of the HFA chains. The structures were the same or similar to that of HFA in castor oil except that the HFA of odd numbered carbon atoms were not detected in castor oil. OH18:1 was identified in the mushroom and its structure was not OH1218:19 (ricinoleate) as that in castor oil. Ricinoleate and/or HFA (OH18:1) structurally similar to ricinoleate was likely the biological precursors of these HFA in mushroom.

Lipase is one of the widely used biocatalysts, which is well studied for its application in industrial production. Recently, lipases with special characteristics such as thermo-stability, alkaline-, acidic nature, and cold-activity, have gained attention for effective applications in specific purposes. Previously, Pichia lynferdii NRRL Y-7723 was reported to produce high amounts of extracellular cold-active lipase (Kim et al., 2010). In this study, we report the identification of lip1 gene that encodes an extracellular cold-active lipase from P. lynferdii NRRL Y-7723. The open reading frame of the gene consisted of 1122 bp of nucleotides that encoded a protein with 373 amino acids. The deduced molecular weight and isoelectric point were 41.8 kDa and pH 5.82, respectively. The lip1 gene was cloned into a bacterial expression vector, and the recombinant lipase was successfully expressed and purified. Several parameters of the recombinant lipase were analyzed, and Lip1 showed high activity at low temperature.

Edible Philippine mushrooms including Ganoderma lucidum have many health benefits. Seventy-two molecular species of triacylglycerols and five molecular species of diacylglycerols containing hydroxy fatty acids (FA) in the lipid extract of this mushroom were identified by HPLC and MS. The mono-, di- and tri-hydroxy FA constituents of the molecular species of acylglycerols were identified by various degrees of dehydration of [FA + Li] + . Many odd carbon numbered hydroxy FA constituents of acylglycerols were also identified. The contents of the 77 molecular species of acylglyerols and their constituent hydroxy FA in the lipid extract were estimated by the relative ion signal intensities of the molecular species of acylglycerols and the HPLC peak area % (ELSD). The contents (%) of the molecular species of acylglycerols containing hydroxy FA in the lipid extract were as: P-19:0-2OH18:2, 0.69%; 2OH18:2-2OH18:2-2OH18:2, 0.60%; P-OH19:1-OH19:1, 0.48%; S-OH19:1-OH19:1, 0.43%; 19:0-19:0-2OH18:2, 0.27% and the total of about 5.8%. “2OH18:2” stands for dihydroxy FA with 18 carbon atoms and two double bonds. The mushroom lipid extract was 1.67% of freeze-dried mycelium. The contents (%) of individual hydroxy FA in the mushroom lipid extract in decreasing order were: 2OH18:2, 1.4%; OH19:1, 1.1%; OH18:1, 0.38%; 2OH19:0, 0.19%; 2OH18:0, 0.13% and the total of about 3.5%. The odd carbon numbered hydroxy FA was about 1.44% of the mushroom lipid extract. The high contents of acylglycerols containing hydroxy FA, odd carbon numbered FA and odd carbon numbered hydroxy FA in edible mushroom might be related to one or more of its health benefits. As far as we are aware of, this mushroom contains the highest amounts of hydroxy FA and odd carbon numbered FA among the human foods.

We identified the lipid species of the solvent extract from liquid-cultured mycelium of G. lucidum NRRL66208. The molecular species of acylglycerols containing all normal fatty acids were identified. One hundred and three molecular species of acylglycerols containing all normal fatty acids were identified by the MS fragmentation involved their constituent fatty acids. The chain lengths of the constituent fatty acids were from 14 to 26 carbon atoms and the numbers of double bonds were from zero to three. The contents of the molecular species of triacylglycerols in the mushroom lipid extract in decreasing order were: OOP (2.45%), OOO (1.94%), LLP (1.92%), OLP (1.80%), LLO (1.57%), OPP (1.30%), OOL (1.09%), OOS (0.88%), and LLL (0.85%). Forty one molecular species of acylglycerols out of 103 contained fatty acids with odd numbered carbon atoms. The fatty acids with odd numbered carbon atoms were 15:0, 17:0, 17:1, 19:0, 19:1, 21:0, 23:0 and 25:0. The total content of fatty acids with odd numbered carbon atoms was about 6.6% of all of the fatty acids of the triacylglycerols containing three normal fatty acids, and contents of individual fatty acids with odd numbered carbon atoms were as: 15:0 (2.76%), 17:0 (2.13%), 17:1 (1.35%), 19:0 (0.20%), 19:1 (0.17%). The contents of fatty acids with odd numbered carbon atoms in mushroom were high compared to those in higher plants. This is the first report on the molecular species of acylglycerols in mushroom.

This paper highlighted the antioxidant and antibacterial activities of Lentinus tigrinus and Pleurotus djamour . Extracts of mushroom fruiting bodies were obtained using hexane and acetonitrile solvents. Acetonitrile extracts of both mushrooms exhibited higher biological activities than hexane extracts. L. tigrinus acetonitrile extract had 39.2% (EC50 value 637.75 mg/L) radical scavenging activity, contained 451 mg AAE (ascorbic acid equivalent)/g sample total phenolics, and showed 9.48 mm diameter zone of inhibition against Staphylococcus aureus . On the other hand, P. djamour acetonitrile extract had 32.8% (EC50 value 762.19 mg/L) scavenging activity, contained 982 mg AAE/g sample total phenolics, and inhibited S. aureus growth with 9.37 mm diameter zone of inhibition. Both hexane extracts did not show any inhibitory effect against the two bacteria used. Collectively, the acetonitrile extracts of L. tigrinus and P. djamour could be valuable resource of antioxidant and anti- S. aureus compounds which we need to isolate, characterize and identify.

© 2019 Author(s). We study the magnon transport in the nonlocal configuration composed of two Pt strips on top of a yttrium iron garnet, with and without the presence of RF microwaves generated by an on-chip antenna. We find that the spin-Hall induced thermal magnon heating/cooling, the Oersted field, and the Joule heating generated by the alternating current in the Pt injector can significantly influence the spin-pumping signal measured by the Pt detector in the presence of RF microwaves, forcing the spin-pumping voltage to show up in the first and second harmonic signals in the nonlocal magnon transport measurement. These results indicate that the nonlocal magnon transport configuration can serve as a structure to electrically detect and manipulate the spin-pumping signal. Furthermore, certain caution is needed when studying the interplay between incoherent magnon and coherent magnon spin transport in the nonlocal transport configuration, since the change in microwave-induced spin-pumping voltage can overwhelm the incoherent magnon transport signals.

Phaseic acid (PA) is a phytohormone regulating important physiological functions in higher plants. Here, we show the presence of naturally occurring (−)-PA in mouse and rat brains. (−)-PA is exclusively present in the choroid plexus and the cerebral vascular endothelial cells. Purified (−)-PA has no toxicity and protects cultured cortical neurons against glutamate toxicity through reversible inhibition of glutamate receptors. Focal occlusion of the middle cerebral artery elicited a significant induction in (−)-PA expression in the cerebrospinal fluid but not in the peripheral blood. Importantly, (−)-PA induction only occurred in the penumbra area, indicting a protective role of PA in the brain. Indeed, elevating the (−)-PA level in the brain reduced ischemic brain injury, whereas reducing the (−)-PA level using a monoclonal antibody against (−)-PA increased ischemic injury. Collectively, these studies showed for the first time that (−)-PA is an endogenous neuroprotective molecule capable of reversibly inhibiting glutamate receptors during ischemic brain injury.

Silicon nanostructures can improve the bending strength of wafers, but often trap particle contaminates. A double-sided surface nanostructure with a morphology controlled via wet chemical etching is used to both improve the mechanical strength and reduce surface reflection. Compared with a conventional polished silicon wafer, the bending strength was increased by 3.4 times and the surface reflection was reduced to 1%, and so can provide a promising solution for photovoltaic applications. The optically unused side of the wafer was protected by a thin silicon layer that prevented the entrapment of particles that might cause glitches in subsequent fabrication processes, all the while maintaining the enhancement in strength. The particle test confirmed that incorporating protection layer intacts the particle count with polished silicon sample.

This study investigates the differences in the microstructure, defects and mechanical behavior of porous structures from a β-type Ti 24Nb 4Zr 8Sn manufactured by electron beam melting (EBM) and selective laser melting (SLM). The phases, size and shape of melt pool, volume and distribution of defects are analyzed and correlated to the compressive mechanical and fatigue properties. Due to different powder bed temperatures, the microstructure of EBM and SLM samples consists of α+β phases and a single β phase, respectively. The faster cooling rate during SLM promotes the formation of fine β dendrites, which leads to a higher compressive strength (50 ± 0.9 MPa) and lower Young's Modulus (0.95 ± 0.05 GPa) in comparison to the EBM parts (45 ± 1.1 MPa and 1.34 ± 0.04 GPa respectively). The large defects present within solid strut are likely a result of tin vaporization. The tin vapor is more easily trapped during the SLM process due to a smaller laser spot size and a faster cooling rate. This results in a 10 times increase in the number of defects. These defects have a limited influence on both the static properties and low stresses level fatigue strength, but it causes a reduced and variable fatigue life at high stresses level.

Laminaria japonica biomass was investigated as an untapped carbon source for polyhydroxyalkanoates (PHA) accumulation via batch and fed-batch cultivation of three different bacterial strains including Cupriavidus necator NCIMB 11599, Paracoccus sp. LL1, and Bacillus megaterium ALA2. Algal biomass (10% (w/v)) was treated with different sulfuric and hydrochloric acid concentrations (0.1, 0.15, 0.2, and 0.3 N). Increasing acid concentration led to a significant increase in reducing sugar production, giving rise to a maximum production of 6.1 and 5.9 g/L for H2SO4 and HCl pretreatment, respectively. Shake flask culture revealed that C. necator, Paracoccus sp. LL1, and B. megaterium ALA2 were able to produce PHA up to 19–32% of their dry cell weight (DCW) under 2% of reducing sugar supplementation. Overall, C. necator showed the highest level of PHA accumulation (1.58 g/L, 32% of DCW). By batch and fed-batch culture, PHA content was enhanced to 44 and 49%, respectively. Along with PHA, Paracoccus sp. LL1 was able to produce 0.9 mg/L of carotenoids after 96 h of cultivation in flask culture. Carotenoid production was enhanced by batch and fed-batch culture to 1.45 and 2.3 mg/L, respectively. Based on Fourier transform infrared spectroscopy, gas chromatography, and 1H nuclear magnetic resonance spectroscopy, the produced PHA polymers were identified as poly(3-hydroxybutyrate) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate).

Lentinus (Family Polyporaceae) is one of the most common fungal groups of wild edible mushrooms found in the Philippines. In our intention to determine the nutritional requirements, this paper highlights the effect of different carbon sources, nitrogen sources, carbon to nitrogen ratios, mineral salts, organic acids, phytohormones, and vitamins on the mycelia growth of Lentinus swartzii, Lentinus strigosus, and Lentinus tigrinus on solid media. Mycelia favourably grew on starch, fructose, and sucrose and on ammonium chloride, yeast extract, and malt extract at C/N ratio of 10:1, 10:1, and 40:1, respectively. The most suitable minerals were KH2PO4 for L. swartzii, ZnSO4•7H2O for L. strigosus, and all minerals tested except CuSO4•5H2O for L. tigrinus. Organic acids such as lactic acid, acetic acid and citric acid also enhanced the mycelial growth. Growth-stimulating phytohormone, gibberellic acid (GA) and vitamin, pyridoxine produced superior mycelial growth of the three mushrooms. The results suggest the unique nutritional requirements of each Lentinus species evaluated, which are of significance in the formulation of chemically-defined culture media for efficient production of mycelia of consistent quality.

New polyurethanes were synthesized based on dihydroxy fatty acid obtained by the microbial conversion of olive oil. Monounsaturated 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was produced from olive oil by Pseudomonas aeruginosa PR3 and reacted with hexamethylene diisocyanate (HMDI) at different ratios to form polyurethanes. Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry confirmed the synthesis of DOD. The thermal and tensile properties of the polyurethanes were investigated by differential scanning calorimetry, thermogravimetric analysis, and a universal testing machine. At an isocyanate/hydroxyl ratio of 1.4, the polyurethane exhibited an elongation at break of 59.2% and a high tensile strength of 37.9 MPa. DOD was also mixed with polycaprolactone diol or polyethylene glycol at different weight ratios and then reacted with HMDI to produce new polyurethanes of various properties. These polyurethanes displayed higher elongation at break and good thermal stability. This is the first report on the synthesis of polyurethanes based on DOD produced by the microbial conversion of vegetable oil.

The progress in the understanding of the microbiology and biochemistry of methylotrophs can be attributed largely to Whittenbury and co-workers who isolated and characterized many methane-oxidizing bacteria, and to Quayle and co-workers who unveiled the metabolic pathways of C1 compounds in methylotrophs. Methylotrophic bacteria are recognized by their ability to use, as sole carbon and energy sources for growth, compounds that contain no carbon-carbon bonds and to assimilate carbon as formaldehyde or a mixture of formaldehyde and carbon dioxide. They are different from methanogenic bacteria which produce methane from organic compounds. Methylotrophic bacteria contain two different types of formaldehyde (aldehyde) dehydro genase activity in crude soluble extracts. There are two routes for the oxidation of methylamine in methylotrophic bacteria. The direct route is catalyzed by methylamine dehydrogenase. The second route involves N-methylglutamate as an intermediate. Methylotrophs play an important role in carbon recycling in the biosphere.

The objective of this study is to identify the chemical species of the polyol oil products produced from soybean oil by Pseudomonas aeruginosa E03-12 NRRL B-59991. We reported earlier the polyol products produced from soybean oil by Acinetobacter haemolyticus A01-35 (NRRL B-59985) ( Hou and Lin, 2013 ). The polyol oil produced by strain A01-35 were a mixture of 57 molecular species of DAG containing tri-, di-, mono-hydroxy FA and normal FA. In this study, tricaprylin was selected as internal standard for HPLC quantitative estimation of products. A CombiFlash chromatographic method was established for separation of the polyol oil products. The molecular species of the polyol oils produced from soybean oil by strain E03-12 were identified with HPLC/MS. We identified 41 derivatives of DAG, among them 32 molecular species containing one hydroxy FA and one normal FA, 8 molecular species containing two hydroxy FA without normal FA, and one molecular specie containing two normal FA without hydroxylated FA. The hydroxy FA included mono-, di- and tri-hydroxy FA. Eight molecular species of DAG containing one trihydroxy FA and 14 molecular species of DAG containing one dihydroxy FA. We have also identified 64 molecular species of TAG, among them 13 molecular species containing two hydroxy FA, 42 molecular species containing one hydroxy FA and 9 molecular species containing no hydroxylated FA. This is different from our previous findings with A. haemolyticus A01-35 which produced only DAG polyol oils. E03-12 is a better strain for developing into an industrial bioprocess.

Branched styrene–acrylic resins were prepared through radical polymerization using cheap 2-(3-mercaptopropionyloxy) ethyl methacrylate (MPOEM) as the chain transfer monomer (CTM). The monomers were added dropwise into the reaction vessel containing xylene at 135°C to obtain styrene–acrylic resins. The formation of branching and the molecular weight were analyzed using triple detection size exclusion chromatography (TD-SEC). The viscosities of the resins were characterized using rotational rheometer and Grignard tube viscometer. By adjusting the dosage of MPOEM and the initiator, a series of branched styrene–acrylic resins were obtained. Generally, the viscosity and the flow ability of the resin were improved evidently when branching was introduced. At the mole ratio of monomer to MPOEM of 100/0.1, the branched styrene–acrylic resin showed 51% decrease in zero-shear viscosity and 62% increase in flow ability, compared with the linear analogues with similar molecular weight at 70% solid content.

Recently we reported methods for microbial screening and production of polyol oils from soybean oil through bioprocessing (Hou and Lin, 2013). Soy-polyol oils (oxygenated acylglycerols) are important starting materials for the manufacture of polymers such as polyurethane. Currently, they are produced by a two-step chemical process involving epoxidation and subsequent opening of the oxirane ring. A total of 650 cultures isolated from soil samples collected from a biodiesel plant in Iowa and from soil and water samples collected from Peoria, IL were screened for the production of polyol oil from soybean oil. Out of these 650 cultures screened, 50 cultures were positive for converting soybean oil to two product groups: diacylglycerol polyol oil (polyol DAGs) and diacylglycerol (DAD) with normal fatty acids. These two product groups can be separated by a two-solvent system TLC. In this study, we identified the 11 most active of these positive cultures using 16S rRNA gene analysis. The 11 strains investigated were found to be bacterial and no active yeast strains were found in the present study. Phylogenetic analysis identified two strains A01-35 and E03-25 as Acinetobacter haemolyticus, a single strain was identified as Pseudomonas aeruginosa, the other active strains were identified as Pseudomonas protegens.

Lipases with abnormal functionalities such as high thermostability and optimal activity at extreme conditions gain special attentions because of their applicability in the restricted reaction conditions. In particular, coldactive lipases have gained special attentions in various industrial fields such as washer detergent, pharmaceutical catalyst, and production of structured lipid. However, production of cold-active lipase is mostly found from psychrophilic microorganisms. Recently we found a novel cold-active lipase from Pichia lynferdii Y-7723 which is mesophilic yeast strain. In this study, we purified the cold active lipase and the enzyme was further characterized in several parameters. The enzyme was purified with 33 purification fold using chromatographic techniques and the purified lipase represented maximum lipolytic activity at 15°C and the maximum activity was highly dependent on pH.

The optical and mechanical properties of aluminium oxide barrier layers are characterised in this work. Atomic layer deposition is utilised to grow high-performance aluminium oxide (Al2O3) barrier films on flexible polyethylene terephthalate substrates, where the effects of precursor pulse time and deposition temperature on the film properties are also studied. Significant observations on the surface roughness, optical transmittance, adhesion and the mechanical properties of the deposited films are also conducted. The results show that the Al2O3 film deposited with a 10 ms precursor pulse time and a 60°C deposition temperature gives the best performance.

Oxylipins are known to have several biological functions. The oxylipin 7,10-dihydroxy-8(E)-octadecenoic acid (DOD), produced from oleic acid by Pseudomonas aeruginosa, was reported to have strong antibacterial activities against broad range of food-borne and plant pathogenic bacteria. Among DOD producers, P. aeruginosa PR3 shows efficient production of DOD from oleic acid, triolein, and olive oil. In this study, we report the serendipitous isolation and characterization of a variant strain of PR3, which upon examination showed higher efficiency for DOD production from olive oil than the original PR3 strain. Compared with the PR3 strain, the variant strain displayed enhanced DOD production by 47.6% and different carbon requirements for maximum DOD production. Considering the advantageous differences seen in this study, we propose the further characterization of this new strain and optimization of culture conditions for efficient DOD production.

This letter presents a wafer-level approach for producing rollable single-crystal silicon integrated circuit (IC) wafers, bent with a 17-mm minimum radius of curvature, achieved by backside nanotexturing. The three-point bending test indicates a mechanical strength enhancement by a factor of 2.3 for nanotextured 60- $\mu \text{m}$ thick samples. The minimum radius of curvature decreased by 43.4%, exhibiting improved flexibility. The carrier charge mobility increases by 4.9%, 12.6%, and 16.9% for the bending radii of 45, 30, and 24 mm, respectively. The increment of the mobility corresponds with the changing compressive stress in p-MOSFETs fabricated on the IC wafer.

Photovoltaic, microelectromechanical systems, and integrated circuit industries are demanding a technology to enable the high rupture resistant silicon wafer production to improve the manufacturing yield. The presented silicon nanotexture patterning on the edges and sidewalls by wet chemical etching process can protect single-crystalline and multicrystalline silicon samples from rupture. Bending tests indicate a mechanical strength enhancement of ~ 72%-75% for sc-silicon and ~71%-73% for mc-silicon samples. In addition, the front and back surfaces of the samples remain intact and appropriate for any further semiconductor processes. This technology was implemented in solar cells that exhibited a strength improvement of nearly 73% without affecting their photovoltaic performances, anticipating an effective solution for the solar cell manufacturing industry.

Microbial conversions of the free unsaturated fatty acids often generate novel hydroxy fatty acids (HFA), which are known to have special properties such as higher viscosity and reactivity. Among microbial strains known to produce HFAs, Pseudomonas aeruginosa PR3 has been well studied to produce 7,10-dihydroxy-8( E )-octadecenoic acid (DOD) from the free oleic acid. Previously we reported that the strain PR3 could utilize olive oil instead of oleic acid as a substrate for production of DOD (Suh et al., 2011. Applied Microbiology and Biotechnology, 89, 1721–1727). In this study, we evaluated the environmental parameters for DOD production from olive oil by PR3. DOD production was closely related to the species and concentration of carbon source. Glucose and galactose showed optimal DOD production at 0.2% and 0.4%, respectively. Addition of 1.5% oil substrate to the culture 36 h after initiation of cultivation under 200 rpm represented a maximal 318 mg DOD production in 50 ml culture, corresponding to 85% conversion yield over the oleic acid content in olive oil.

Novel biobased crosslinked polymer networks were prepared from vegetable oil with 2,5-furan diacrylate as a difunctional stiffener through UV photopolymerization, and the mechanical properties of the resulting films were evaluated. The vegetable oil raw materials used were acrylated epoxidized soybean oil (AESO), acrylated castor oil (ACO), and acrylated 7,10-dihydroxy-8(E)-octadecenoic acid (ADOD). 2,5-Furan dicarboxylic acid (FDCA), which can be synthesized through the oxidative dehydration of C6 sugars, was identified by the US Department of Energy as one of 12 priority chemicals for establishing the green chemistry industry of the future. 2,5-Furan dimethanol (bis-hydroxymethylfuran), which can be derived from FDCA, was used as a starting material to synthesize 2,5-furan diacrylate, which was used as a biobased comonomer along with AESO, ACO, or ADOD to form photo-crosslinked polymer networks. The synthesis of acrylate derivatives was confirmed using FT-IR and 1H-NMR spectroscopic techniques. The composition of the reaction mixture was changed to obtain crosslinked polymer networks with various mechanical properties. The addition of 2,5-furan diacrylate increased the tensile strengths of the polymer films by up to 1.4–4.2 times relative to those obtained without the addition. These fully biobased polymers derived from vegetable oil and sugar can be used as environmentally friendly renewable materials for various applications to replace the existing petroleum-based polymers currently used. Copyright © 2013 John Wiley & Sons, Ltd.

Lipases with abnormal properties such as thermostability, alkalinity, acidity, and cold activity receive industrial attention because of their usability under restricted reaction conditions. Most microbial cold-active lipases originate from psychrotrophic and psychrophilic microorganisms found in Antarctic regions, which has led to difficulties in the practical production of cold-active lipase. Recently, a mesophilic yeast, Pichia lynferdii NRRL Y-7723, was reported to produce a novel cold-active lipase. This study focused on optimization of environmental factors, while giving particular attention to the relationships between given factors and incubation time, to maximize the production of a novel cold-active lipase from P. lynferdii NRRL Y-7723. Maximum lipase production was highly dependent on the incubation time at a given environmental factor. Lipase production varied with incubation time at a given temperature, and 20 °C was selected as the optimum temperature for lipase production. Fructose was selected as the best carbon source, and maximum lipase production was obtained when it was present at 0.7% (w/v). Yeast extract was an efficient organic nitrogen source, with maximum lipase production occurring at 0.9% (w/v). Specifically, at the optimum yeast extract level the lipase production was10 times higher than the productivity under standard conditions. All natural oils tested showed lipase production, but their maximum productivities varied according to incubation time and oil species.

Soypolyol oils (oxygenated acylglycerols) are important starting materials for the manufacture of polymers such as polyurethane. Currently, they are produced by a two-step chemical process involving epoxidation and the subsequent opening of the oxirane ring. The objective of this study is to develop a bioprocess to produce polyol oils directly from soybean oil. For product separation, we found that TLC with a two step development solvent systems could separate the polyol products from substrate soybean oil. The products and substrates were separated in the following order: substrate triacylglycerols (Rf 0.8), free fatty acids (FA, Rf 0.7), product dihydroxy TAG (Rf 0.4), trihydroxy TAG (Rf 0.3), monohydroxy FA (Rf 0.1) and dihydroxy FA (Rf 0.05). We also found that HPLC with a C18 reverse phase column and a linear gradient of 100% methanol to 100% 2-propanol over 60 min at 1 mL/min flow rate was able to separate product polyol oils and substrate soybean oil. Free FA and polyol oils (diacylglycerols (DAG) containing hydroxyl FA) were eluted between 5 min and 15 min. DAG containing two normal FA was eluted between 15 min and 28 min and the substrate soybean oil was eluted between 36 min and 45 min. A total of 400 microbial cultures were screened and we identified 25 hits. Polyol oils' products were purified through a silica gel column chromatography, fractionated by HPLC and then analyzed by MS. A total of 57 molecular species of DAG containing tri-, di-, monohydroxy FA and normal FA were identified by MS. HPLC chromatogram of evaporative light scattering detector was used for semi-quantification of these DAG in the purified polyol oils. The total content of the DAG containing two normal FA was about 25% and the total content of DAG containing hydroxy FA might be about 75%. The yield of bioconversion by culture A01-35 from soybean oil to polyol oil products (DAG containing hydroxyl FA) plus DAG containing normal FA was 31% by weight. Bioconversion of soybean oil to polyol oils is a new research area without available methodology to follow. Here we report a new bioprocess for the production of soypolyol oils directly from soybean oil.

To investigate whether curcumin regulates Notch signaling to cause neuroprotection and neurogenesis after focal ischemia reperfusion injury.Focal ischemia reperfusion injury was modeled in rats by occluding the middle cerebral artery. These animals were given either curcumin (300 mg/kg) or corn oil (vehicle) by intraperitoneal injection starting 1 h after stroke and continuing for 7 d. In parallel, sham-operated control animals received vehicle. All animals were killed on day 12. The different treatment groups were compared in terms of neurobehavioral deficits, BrdU incorporation, and levels of doublecortin (DCX) and Notch intracellular domain (NICD) using immunohistochemistry, immunofluorescence and Western blotting.Animals treated with curcumin showed significantly smaller neurobehavioral deficits than vehicle-treated animals after 3, 7, and 12 d of reperfusion (all p 0.05). Tissue sections from curcumin-treated animals contained significantly greater numbers of BrdU-positive cells (p 0.05) and BrdU/DCX-positive cells (p 0.01), as well as significantly higher NICD levels (p 0.01).Curcumin may protect from focal cerebral ischemia reperfusion injury as well as stimulate neurogenesis by activating the Notch signaling pathway.

Backside nanotexturing fabricated by electroless metal assisted wet chemical etching, protected with a deposited thin silicon layer, is a new approach to create high bending strength silicon samples. Bending strength for protected nanotextured samples followed by CMP process was enhanced by ∼3.4 folds as compared to polished silicon samples, which emphasize the possibility of industrial implementation. The morphology of silicon deposition layer upon nanotexture influences the stress behavior, which need an adequate fabrication technique for uniform deposition at wafer scale. The thin protection layer upon nanotexture prevents the unwanted particle trapping, which affects the electrical performances of the device. Moreover, this technology provides a rupture resistive solution for IC, MEMS and photovoltaic devices for industrial implementation.

In Arabidopsis thaliana in vitro culture, shoots were induced from the shoot apical meristem (SAM) of germinating seeds in the presence of 2,4-dichlorophenoxyacetic acid. Primary shoot primordia developed leaf-like structures, from which secondary shoot primordia were produced. Regenerated shoots were recovered when the material was transferred to a medium lacking auxin. Adventitious roots formed from a callusing basal region of the secondary shoots. The CUC1 transcription factor was expressed at the apex of the primary shoot primordium and at the boundary between the regenerated SAM and the developing leaf primordia. The DR5::GUS transgene was used to localize sites of maximum auxin occurrence. Auxin was firstly detected in the dividing cells beneath the SAM epidermis, which coincided with sites where primary shoot primordia were initiated. In the regenerated shoots, auxin response was not detected in the basal region of the stem, suggesting that the regenerating structures were shoots rather than somatic embryos. Direct shoot regeneration from the A. thaliana SAM requires a localized accumulation of auxin.

Castor oil can be used in industry. The molecular species of triacylglycerols containing hydroxy fatty acids (FA) in castor oil have been identified. We report here the identification of twelve diacylglycerols (DAG) containing hydroxy FA in castor oil using positive ion electrospray ionization mass spectrometry of the lithium adducts. They were RR (diricinolein, R is ricinoleate), RL, RS, R-diOH18:0, R-diOH18:1, R-diOH18:2, R-triOH18:0, R-triOH18:1, R-triOH18:2, diOH18:0-diOH18:1, diOH18:1-diOH18:1 and diOH18:1-diOH18:2. The MS2 fragment ions, [M + Li − FA]+ and [FA + Li]+, from the lithium adducts of DAG containing hydroxy FA (one or two hydroxy FA), were used for the identification. The additional fragment ions from the neutral losses of FA lithium salts [M + Li − FALi]+ were used for the identification of eleven DAG containing two normal FA in a soybean oil bioconversion product. The MS2 fragment ions from the neutral losses of FA lithium salts [M + Li − FALi]+ were not detected from the DAG containing hydroxy FA. The DAG containing FA with more hydroxyl groups than the other FA on the same DAG molecule tended to have a prominent fragment ion [FA + Li]+ and an undetectable fragment ion [M + Li − FA]+ while the FA was the more hydroxylated FA. Also the less hydroxylated FA of a DAG tended to have a prominent fragment ion [M + Li − FA]+ and an undetectable fragment ion [FA + Li]+ while the FA was the less hydroxylated FA.

Repetitive sequences of DNA are meaningful and of great importance to human functions. Previous researchers have proposed various methods to discover repetitive sequences in DNA sequence. However, the unknown lengths for repetitive sequences are usually predicted randomly or determined by rules of thumb rather than using a systematical criterion. We propose a new algorithm based on the cumulative Fourier spectral contents of DNA sequence to identify the candidate lengths of repetitive sequences or repeats in DNA sequences. After the candidate lengths of repeats are known, one can identify the repeats and their copy numbers using an exact method. Both of the simulated and real datasets are used to illustrate the performance of the proposed algorithm. The results are also compared to two well-known methods such as Spectral Repeat Finder (SRF) and Gibbs sampler. Furthermore, we demonstrate the use of CSRF in some well-known repeats-finding methods such as SRF, Gibbs sampler, MEME.

Microbial modification of naturally occurring materials is one of the efficient ways to add new values to them. Hydroxylation of free unsaturated fatty acids by microorganism is a good example of those modifications. Among microbial strains studied for that purpose, a new bacterial isolate Pseudomonas aeruginosa PR3 has been well studied to produce several hydroxy fatty acids from different unsaturated fatty acids. Of those hydroxy fatty acids, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was efficiently produced from oleic acid by strain PR3. However, it was highly plausible to use vegetable oil containing oleic acid rather than free oleic acid as a substrate for DOD production by strain PR3. In this study, we firstly tried to use olive oil containing high content of oleic acid as a substrate for DOD production. DOD production from olive oil was confirmed by structural determination with GC, TLC, and GC/MS analysis. DOD production yield from olive oil was 53.5%. Several important environmental factors were also tested. Galactose and glutamine were optimal carbon and nitrogen sources, and magnesium ion was critically required for DOD production from olive oil. Results from this study demonstrated that natural vegetable oils containing oleic acid could be used as efficient substrate for the production of DOD by strain PR3.

Hydroxy fatty acids (HFAs), originally obtained in small amounts from plant systems, are good examples of structurally modified lipids, and they render special properties such as higher viscosity and reactivity compared to normal fatty acids. Based on these properties, HFAs possess high industrial potential in a wide range of applications. Recently, various microbial strains were tested for the production of HFAs from different unsaturated fatty acids since HFA production is limited to plant systems. Among the microbial strains tested, Pseudomonas aeruginosa PR3 has been well studied for the production of 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) from oleic acid. Previously, we reported that strain PR3 could utilize triolein instead of oleic acid as a substrate for the production of DOD (Appl. Microbiol. Biotechnol. 2007, 74: 301–306). In this study, we focused on utilization of vegetable oil as a substrate for DOD production by PR3. Consequently, strain PR3 efficiently utilized high oleic safflower oil as a substrate for DOD production. Optimal initial medium pH and incubation time were pH 8.0 and 72 h, respectively. Optimal carbon and nitrogen sources were fructose and glutamine, respectively. Results from this study demonstrate that normal vegetable oils could be used as efficient substrates for the production of value-added HFAs by microbial bioconversion.

Lipoxygenases (LOXs) constitute a family of lipid-peroxidizing enzymes that catalyze the oxidation of unsaturated fatty acid containing a (1Z,4Z)-pentadiene structural unit, leading to formation of conjugated (Z,E)-hydroperoxydienoic acid. LOXs are known to be widely distributed in plants and animals. Recently, several microbial LOXs were reported to be involved in the production of hydroperoxy fatty acids. Among the microorganisms that produce hydroxy fatty acids, Pseudomonas aeruginosa PR3 is known to convert linoleic acid to trihydroxy fatty acid, which suggests the involvement of a LOX enzyme. Based on these reports, we identified a novel thermostable LOX from P. aeruginosa PR3 strain. The protein was purified 34.3-fold with a recovery rate of 5.14%. The Km and Vmax values of the purified enzyme were 3.57 mM and 0.73 μmol/min//mg, respectively. Heat stability of the purified enzyme was unexpectedly high with an LD50 of 90 min at 80°C, although P. aeruginosa PR3 is known as a mesophilic bacterium. Substrate specificity of the purified enzyme was restricted only to unsaturated fatty acids carrying a (1Z,4Z)-pentadiene unit.

Structured lipids (SL) were synthesized by the acidolysis of borage oil with caprylic acid using lipases. Six commercial lipases from different sources and a novel lipase from Pichia lynferdii NRRL Y-7723 were screened for their acidolysis activities and Lipozyme RM IM and NRRL Y-7723 lipase were selected to synthesize symmetrical SL since recently NRRL Y-7723 lipase was identified as a novel cold-active lipase. Both lipases showed 1,3-regiospecifity toward the glycerol backbone of borage oil. The effects of enzyme loading and temperature on caprylic acid incorporation into the borage oil were investigated. For Lipozyme RM IM and NRRL Y-7723 lipase, the incorporation of caprylic acid increased as enzyme loading increased up to 4% of total weight of the substrate, but significant increases were not observed when enzyme loading was further increased. The activity of NRRL Y-7723 lipase was higher than that of Lipozyme RM IM in the temperature range between 10 and 20 °C.

Novel crosslinked thin polymer networks based on vegetable oil hydroxy fatty acids (HFAs) were prepared by UV photopolymerization and their mechanical proper- ties were evaluated. Two raw materials, castor oil and 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) were used as sources of mono- and di-HFAs, respectively. Poly (ethylene glycol) (PEG) diacrylate and poly(e-caprolac- tone) diacrylate were synthesized and used as crosslinking agents to form crosslinked polymer networks by UV-ini- tiated free-radical polymerization with acrylated castor oil or acrylated DOD. The synthesis of acrylate derivatives was confirmed using FT-IR and 1 H-NMR spectroscopic techniques. The composition of the reaction mixture and the type/length of crosslinking agent were changed to obtain crosslinked polymer networks with various mechanical properties. For polymers prepared from high molecular weight (20,000) PEG, a 58-60% of the initial weights decreased in 35 days in phosphate buffer solution (pH 7.2) containing lipase enzyme. These potentially bio- degradable polymers based on vegetable oil HFAs can be used as eco-friendly materials for various applications to replace the existing petroleum-based polymers currently used.

Intracellular calcium ([Ca(2+)]i) influx through N-methyl-d-aspartic acid (NMDA) receptors in cortical neurons is central to NMDA receptor-mediated excitotoxicity. Drugs that uncompetitively modulate NMDA receptor-mediated [Ca(2+)]i influx are potential leads for development to treat NMDA receptor-mediated neuronal damage since these drugs spare NMDA receptor normal functions. Ligands to alpha(2)-adrenoceptors and imidazoline I(2) receptors confer neuroprotection possibility through modulating NMDA receptor-mediated [Ca(2+)]i influx. Here, we investigated the characteristics of several ligands to alpha(2)-adrenoceptors and imidazoline I(2) receptor, in inhibiting NMDA receptor-mediated [Ca(2+)]i influx in cultured cortical neurons using a ratiometric calcium imaging technique. In contrast to MK801, which non-reversibly blocks NMDA receptor-mediated [Ca(2+)]i influx, imidazoline I(2) receptor antagonists, Idazoxan, and 2-(2-benzofuranyl)-2-imidazoline (2-BFI)-mediated inhibition of [Ca(2+)]i influx can be rapidly reversed when removed, in a manner similar to that of memantine, an uncompetitive antagonist to NMDA receptors. Interestingly, ligands to alpha(2)-adrenoceptors, including agmatine sulfate and yohimbine, and a ligand to the nicotinic receptor, levamisol, neither inhibited NMDA receptor-mediated [Ca(2+)]i influx, nor provided neuroprotection against glutamate toxicity, suggesting selective inhibition of NMDA receptor activities. The inhibition of NMDA receptor by Idazoxan and 2-BFI also led to the suppression of NMDA receptor-mediated calpain activity as a result of blocking NMDA receptor activity, rather than through direct inhibition of calpain activity. Collectively, these studies demonstrated that imidazoline I(2) receptor antagonists transiently and reversibly block NMDA receptor-mediated [Ca(2+)]i influx. These compounds are leads for further development as uncompetitive antagonists to NMDA receptor-mediated excitotoxicity.

Lipase (triacylglycerol acylhydrolases, E.C. 3.1.1.3) is one of the most important enzymes applied to a broad range of industrial application fields. Especially, lipases with abnormal functionality such as thermostability and alkaline, acidic, and cold activities gain special attention because of their applicability in the restricted reaction conditions. In this study, 16 yeast strains prescreened for lipase induction were investigated for their actual lipase production, and we found a novel cold-active lipase produced from Pichia lynferdii Y-7723. The activity of lipase Y-7723 was retained by 74 and 70% at 20 and 10 degrees C, respectively, as compared to the maximum value at 35 degrees C. On the basis of an optimization study, the optimal lipase productivity was obtained at 96 h of incubation with 3% oil substrate in a medium composed of sucrose as a carbon source at pH 7.0. Among carbon sources tested, sucrose showed almost twice as high of a lipase production (184%) as the control, while the cell growth was similar (105%). Yeast extract and ammonium salts were effective as individual nitrogen sources for lipase production. This study demonstrated that the cold activity of lipase Y-7723 at 10 degrees C was highest among the cold-active lipases reported so far.

Flavobacterium sp. strain DS5 (NRRL B-14859) was used to convert two vegetable oils, olive oil and soybean oil, directly to oxygenated fatty acids such as 10-ketostearic acid (10-KSA) and 10-hydroxystearic acid (10-HSA). Lipase addition to the culture was required because strain DS5 did not induce lipase activity to release free fatty acids from vegetable oils. 10-KSA production was higher from olive oil than from soybean oil because olive oil contains more oleic acid, the precursor of 10-KSA. The optimum amounts of olive oil and lipase addition for 10-KSA production were determined as 0.3ml and 1mg (specific activity=700units/mg) per 50ml culture medium, respectively. At these conditions, 2.8g/L of 10-KSA and 0.40g/L of 10-HSA were obtained from olive oil as a substrate.

Among the three groups of natural products (starch, protein and fat), fat and oil are the most under-investigated. The US has a large amount of surplus soybean oil annually, and using vegetable oils or their component fatty acids as starting material provides a new opportunity for bioindustry. Vegetable oils are relatively inexpensive and can be used to manufacture value-added products such as oxygenated oils and fatty acids. Oxygenated fatty acids are common in nature and are important industrial materials. They exist both in mammals and plants. Microorganisms oxidize fatty acids either at the terminal carbon or inside of the acyl chain to produce hydroxyl or keto fatty acids. In our continuing effort to produce value-added products from vegetable oils, we discovered more than one dozen novel oxygenated fatty acids through biotransformation. Microbial hydratase is a carbon 10 positional specific enzyme. Many of these new oxygenated fatty acids possess physiological activities and can be used as biomedicals, in addition to their known applications such as specialty chemicals. The position of hydroxyl groups on the fatty acyl carbon chain plays an important role in the activity against certain specific plant pathogenic fungi. Bacillus megaterium ALA2 converted polyunsaturated fatty acids (PUFA) in different ways. It converted omega-6 PUFAs to a mixture of diepoxy bicyclic, tetrahydrofuranyl rings, and/or trihydroxy groups in their molecules while the products from omega-3 PUFAs produced only hydroxyl tetrahydrofuranyl ring products. The monooxygenase gene of strain ALA2 was sequenced and is a soluble, self-sufficient P450(BM-3) subclass that was highly homologous with the wild-type protein. This new enzyme also possessed a significant high homology in all of the expected reductase regions as well. Fat and oil represent an area with tremendous opportunity for new biotechnology to explore.

The trapping characteristics of positive bias temperature instability (PBTI) on a high-k/metal gate n-type metal oxide semiconductor field effect transistor (nMOSFET) have been investigated with a complementary multi-pulse technique (CMPT) in detail. With the CMPT technique, we found the threshold voltage shifts after PBTI are higher than that with the conventional direct current method, and the thickness of the SiO 2 interfacial layer has a significant effect on the measured results. The observation of these new results is attributed to the CMPT technique has the unique feature of effectively reducing the detrapping effect induced by the large bulk traps existed in high-k dielectrics. Besides, based on the results, the mechanism of PBTI in metal gate/high-k nMOSFETs is re-modeled.