Minor Bands Research Articles

Determination of ammonium on an integrated microchip with LED-induced fluorescence detection

A simply fabricated microfluidic device integrated with a fluorescence detection system has been developed for on-line determination of ammonium in aqueous samples. A 365-nm light-emitting diode (LED) as an excitation source and a minor band pass filter were mounted into a polydimethylsiloxane (PDMS)-based microchip for the purpose of miniaturization of the entire analytical system. The ammonium sample reacted with o-phthaldialdehyde (OPA) on-chip with sodium sulfite as reducing reagent to produce a fluorescent isoindole derivative, which can emit fluorescence signal at about 425 nm when excited at 365 nm. Effects of pH, flow rate of solutions, concentrations of OPA-reagent, phosphate and sulfite salt were investigated. The calibration curve of ammonium in the range of 0.018–1.8 μg/mL showed a good linear relationship with R2 = 0.9985, and the detection limit was (S/N = 3) 3.6 × 10−4 μg/mL. The relative standard deviation was 2.8% (n = 11) by calculating at 0.18 μg/mL ammonium for repeated detection. The system was applied to determine the ammonium concentration in rain and river waters, even extent to other analytes fluorescence detection by the presented device.

Origin of the Z−28 rule in Mn2Cu-based Heusler alloys: A comparing study

The origin of the Slater–Pauling curve Mt=Zt−28 (Here Mt is the total spin moment and Zt is the number of valence electrons) in half-metallic Heusler alloys Mn2CuZ (Z=Ge and Sb) has been studied in detail. In Mn2CuZ the half-metallic gap has a similar origin like half-Heusler alloys. The Cu atom acts as an electron “donator” in Mn2CuZ, which contributes five d-electrons to the minority spin band of Mn2CuZ. So there are 14 valence electrons in the minority band of Mn2CuZ below the Fermi level. This is the origin of the S–P curve Mt=Zt–28. Finally, it is found that, by partial doping of Cu to the vacant site of half-metallic half-Heusler alloys, the magnetic moments of these can be tuned without destroying the half-metallicity. This can be a possible way to design new half-metals.

The expression of calcitonin receptor detected in malignant cells of the brain tumour glioblastoma multiforme and functional properties in the cell line A172

Previous studies have indicated that expression of calcitonin receptor (CTR) could be induced in a proinflammatory environment. In the present study, CTR-immunoreactivity (CTR-ir) was investigated in brain tissue from patients with glioblastoma multiforme (GBM). In immunohistochemical analysis of GBM samples, tissues with complex glomeruloid structures surrounded by malignant cells were analysed for CTR-ir using anti-human CTR antibodies generated against two separate epitopes of CTR. CTR-ir was associated predominantly with glial cells. Regions with CTR-ir cells were found in 12 of 14 GBM tumours (P < 0.05). Using confocal microscopy, CTR-ir cells were identified that were also positive for glial fibrillary acidic protein, nestin and CD133. Antibodies were verified using immunoblots and confocal microscopy of the Cercopithecus aethiops(COS)-7 transfectants. Immunoblots of membrane preparations from the CTR-positive cell lines demonstrated a major band (≈ 67 kDa) and minor band (≈ 52 kDa), but the intensity was reversed for the GBM cell line A172. In cultured A172 cells, functional studies demonstrated calcitonin stimulation of adenylyl cyclase and inhibition of extracellular-regulated kinase (ERK)1/2 phosphorylation. The findings that (i) CTR was expressed by glioma cells in a majority of GBM tumours tested, (ii) CTR(+) /CD133(+) cells were identified and (iii) second messenger systems were functionally modified by calcitonin in A172 cells suggest that CTR might be a useful therapeutic target in GBM.

Photoluminescence properties of ion-beam-synthesized β-FeSi2 nanocrystals in Si

We have investigated photoluminescence (PL) properties of β-FeSi2 nanocrystals in Si crystals. The PL spectrum could be separated into three major A, B and C bands and some minor bands. The B and C band (side band) spectra with a Gaussian function shape could be deduced from subtraction of the A band spectra with a Lorentzian function shape from the whole PL spectrum observed. It was found that the temperature dependence of the C band emission was quite different from that of the intrinsic band (A band) emission which follows a Varshini empirical formula. The C band emission may be originated from two competition processes which are switched at 70 K.

Spin-flip scattering and dimensional effect on transport of charge and spin across metal/ferromagnet material interfaces

We theoretically study the conductance spectra of metal/ferromagnetic material junctions. There is a change in slope of the conductance spectrum at the energy equivalent to the bottom of the minority band. This feature is most prominent in one-dimensional (1D) systems. For any dimensionality, the interfacial spin-flip scattering can suppress or enhance the conductance, depending on the quality of the junction. When the non-spin-flip or normal scattering is weak, the spin-flip scattering always suppresses the conductance. On the contrary, in the limit where the normal scattering is strong, the conductance can be enhanced to a maximum value, when the strength of the spin-flip and the normal scattering are equal. As for the spin polarization of the conductance, it is largest in the limit where the normal scattering is strong and depends on junction dimensionality. In this limit, the 1D spin polarization is independent of the spin-flip scattering strength, whereas the 2D and 3D spin polarizations can be increased with the strength of the spin-flip scattering up to a maximum value, at which both types of scattering are about the same strength.

Magnetic properties of Mn 3Si from first-principles studies

The Heusler compound Mn 3Si, the antiferromagnet in the Mn-based class of Heuslers which contains several conventional and half-metallic ferromagnet, shows a peculiar stability of its magnetic order in high magnetic fields. We investigated the electronic and magnetic properties of Mn 3Si by band structure calculations based on the density functional theory. The minority bands of Mn 3Si in the spin polarized state are gapped at the Fermi level, which shows a half-metallic behavior of Mn 3Si.

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and random amplified polymorphic DNA (RAPD) based genetic variation studies in eri silkworm (Samia cynthia ricini Lepidoptera: Saturniidae)

Four strains of eri, Samia cynthia ricini Lepidoptera: Saturniidae that can be identified morphologically and maintained at North East Institute of Science and Technology, Jorhat were characterized based on their protein profile by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and DNA by random amplified polymorphic DNA (RAPD) technique. Fiber yield was highest in Gs strain. SDS-PAGE profile showed 11 prominent bands in the strains with molecular weight ranging from 35 to 200 kDa together with 28 minor bands with molecular weight ranging from 33 to 210 kDa. Two polypeptides of molecular weight 90 and 110 kDa were absent in both Y and Ys. Eight random primers and one universal primer used for RAPD analysis generated a total of 79 bands, of which 49 were polymorphic. In both SDS-PAGE and RAPD, the UPGMA based dendrogram showed two clusters: cluster 1 included Gs and G, whereas Y and Ys was grouped in cluster 2 by SDS-PAGE analysis but RAPD analysis grouped Ys and G in cluster 1 and Gs and Y in cluster 2. The range of genetic diversity observed among the strains affirms the potentiality of RAPD technique for identification and selection of distant parents for silkworm hybridization for high silk yield. Key words: Genetic variation, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), random amplified polymorphic DNA (RAPD), silkworm, cocoon.

A Large-Pore IEF Gel Electrophoresis Separates the Complex in Both of ADAMTS13 Bound to VWF and to the IgG Autoantibodies From the Unbound in Plasma Milieu

Abstract 1160 Backgrounds and Aims:Thrombotic thrombocytopenic purpura (TTP) is a life-threatening generalized disorder caused by a deficiency of ADAMTS13 activity due to its gene mutations (Upshaw-Schulman syndrome), and/or acquired autoantibodies to this enzyme. ADAMTS13 specifically cleaves the peptide bond between Tyr1605 and Met1606 within the A2 domain of von Willebrand factor (VWF). Recent studies with immunoprecipitation methods using anti-VWF antibody coated beads indicated that a small portion (3–4% of the total) of plasma ADAMTS13 is bound to VWF (Feys HB et al. JTH 7:2088, 2009). This experiment determined the amount of ADAMTS13 bound to VWF in an indirect fashion, but the complex may dissociate during washing procedures or by conformation change after binding to the antibody. Thus, we used an isoelectric focusing (IEF) to separate the complex in a direct fashion. However, the molecular size of VWF-ADAMTS13 complex is assumed to be enormously huge, and therefore a regular polyacrylamide IEF gel does not properly work. So, we employed a large-pore composite IEF gel consisting 0.75% agarose and 1.25% polyacrylamide containing 2% of Pharmalyte (pI range 3.0–10). By this method followed by western blot detection using a non-neutralizing anti-ADAMTS13 monoclonal antibody (WH2-11-1), we identified that an ADAMTS13-VWF complex is detected as a sharp band at pI 7.4. The specificity of this band was identified by a lack in plasma of type 3 von Willebrand disease (VWD), and a new emergence of the band in type 3 VWD plasma spiked with purified VWF (Hori et al, 57th ISTH meeting, P-MO-479). We applied this IEF analysis to detect the complex of ADAMTS13-its autoantibodies. Patients and Methods:ADAMTS13 activity was measured by chromogenic act-ELISA, and acquired idiopathic (ai-) TTP with severe deficiency of ADAMTS13 activity due the presence of its autoantibodies is a target in this study. VWF and ADAMTS13 were purified from normal plasma. A large-pore composite IEF gel electrophoresis was performed as previously described. Results and Discussion:Two forms of ADAMTS13, unbound (pI 5.3) and bound (pI 7.4) to VWF in a volume of 10 uL normal plasma (NP), were directly identified on the IEF gel followed by western blotting (Fig. left). Each plasma of type 3 VWD or USS lacked the complex (VWF-ADAMTS13) band with pI 7.4, but it was generated in vitro just after spiking the purified VWF or ADAMTS13 to the respective deficient plasma by the IEF (Fig. not shown). [Display omitted] Next, when a volume of 3uL NP was analyzed, only one band with pI of 5.3 (5.1–5.5) was observed. In ai-TTP patients with severe deficiency of ADAMTS13 activity (<3% of the control), plasma had no or faint band of ADAMTS13 (Fig. middle). However, when we mixed the equal volume of patient plasma with ai-TTP with severe deficiency of ADAMTS13 activity and NP, the results on IEF gel showed appearance of 3 major bands with pIs of 5.3, 5.9 and 6.5, together with other many minor bands, and the unbound (free) ADAMTS13 almost disappeared (Fig. right). Then, the IgG purified from patient plasma of ai-TTP was mixed with NP or purified ADAMTS13, the complex band had a pI of 5.9 (5.5–6.3). These results indicated a possibility that the IEF analysis could be used to detect the autoantibodies to ADAMTS13, regardless of the neutralizing or non-neutralizing counterparts, in a totally different fashion to the enzyme immunoassay. Disclosures:Matsumoto:Alexion Pharma: Membership on an entity's Board of Directors or advisory committees. Soejima:The Chemo-Sero-Therapeutic Research Institute: Employment. Fujimura:Baxter BioScience: Membership on an entity's Board of Directors or advisory committees; Alexion Pharma: Membership on an entity's Board of Directors or advisory committees.

Use of HbA2 As a Discriminator for S/Beta Thalassaemia in a Nigerian Setting,

Abstract 4206An integral part of an EU-UNDP funded pilot sickle cell screening project, was the installation, in Abuja (Federal Capital Territory) Nigeria, June 2010, of a High Performance Liquid Chromatography (HPLC) instrument. Prior to the installation, haemoglobinopathy screening was carried out using only unstained paper electrophoresis. Minor bands were difficult to visualise and the proportions of haemoglobins were not measured. Full blood count (FBC) data was also not routinely available. Therefore awareness of both alpha and beta thalassaemia was low as was the implications of coinheritance of beta thalassaemia with haemoglobin (Hb) S.Stratified community surveys were carried out with samples collected as Guthrie card blood spots; children aged less than 6 months, and whole blood; children aged between 6 months and 5 years. Blood spot samples were analysed using newborn sickle cell screening reagents and whole blood samples using beta thalassaemia short reagents, the later allowing accurate Hb A2 and Hb F measurement. Samples were processed on a Biorad™ Classic (instrument and reagents, Biorad, Hercules, CA.). Reporting algorithms were defined for both reagent sets. Using the beta thalassaemia reagents, Hb S/beta thalassaemia was considered when Hb S was predominant, Hb A absent or significantly reduced and the Hb A2>5.Over 10,000 samples were analysed, 410 had sickle cell disease, of which 370 were transported to London for further analysis, 70 of these had an Hb A2>5%, mean and range 5.9(5.1 – 9.1)%. To validate the algorithm 31 samples (Hb A2 3.5 – 7.4%), were selected for beta gene sequencing (Mai et al, 2004) and/or PCR analysis for the 7 common alpha gene deletions (3.7kb, 4.2kb, SEA, MED, THAI, FILL, 20.5kb and triplicated alpha gene locus, anti 3.7kb), (Chong et al, 2000, Wang et al, 2003). Five samples had an Hb A2of 3.5 – 4.9%, 2 with Hb A present (23 and 25%), all were Hb SS, 4 negative for alpha thalassaemia deletions and 1 heterozygous for the alpha 3.7kb deletion. Sixteen samples had an Hb A2 of 5.0 – 5.9%, all were Hb SS, 5 negative for alpha thalassaemia deletions and 11 heterozygous for the alpha 3.7kb deletion. Seven samples had an Hb A2 of 6.0 – 6.9%, 6 were Hb SS, 1 negative for alpha thalassaemia deletions, 1 heterozygous and 4 homozygous for the alpha 3.7kb deletion. One, Hb A2 6.9%, was a compound heterozygote for Hb S/ beta zero codon 106/107(+G) mutation. Three samples had an Hb A2 of 7.0 – 7.4%, review of chromatograms indicated that all showed poor chromatography due to lack of separation between Hb A2 and Hb S or shoulders to the left of the Hb A2 peak. All were Hb SS and heterozygous for the alpha 3.7kb deletion, with 1 also positive for the triplicated alpha globin gene, anti 3.7kb. Four other samples with Hb A2 >7% also showed poor chromatography, but were insufficient for molecular testing.The results indicate that Hb A2values >5% were mainly due to co-existing alpha thalassaemia with 76% of those tested, positive for the 3.7kb deletion. Poor chromatography was also a contributor particularly at the higher Hb A2 levels. During the initial stages of the project air conditioning failure caused major temperature fluctuations on overnight runs, this problem was resolved, improving chromatography. One case of S/beta zero thalassaemia was detected confirming the presence in this population. The results suggest that the Hb A2 may be considered as a discriminator for S/beta thalassaemia screening in this setting, increasing the algorithm Hb A2 level to >6.0% may improve specificity and reduce the number of false positives, this warrants further investigation. Future aims of the project for children over 6 months of age, include initiating routine FBC analysis and testing parental samples as a cost effective means of confirming suspected cases. Disclosures:No relevant conflicts of interest to declare.

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and random amplified polymorphic DNA (RAPD) based genetic variation studies in eri silkworm (Samia cynthia ricini Lepidoptera: Saturniidae)

Four strains of eri, Samia cynthia ricini Lepidoptera: Saturniidae that can be identified morphologically and maintained at North East Institute of Science and Technology, Jorhat were characterized based on their protein profile by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and DNA by random amplified polymorphic DNA (RAPD) technique. Fiber yield was highest in Gs strain. SDS-PAGE profile showed 11 prominent bands in the strains with molecular weight ranging from 35 to 200 kDa together with 28 minor bands with molecular weight ranging from 33 to 210 kDa. Two polypeptides of molecular weight 90 and 110 kDa were absent in both Y and Ys. Eight random primers and one universal primer used for RAPD analysis generated a total of 79 bands, of which 49 were polymorphic. In both SDS-PAGE and RAPD, the UPGMA based dendrogram showed two clusters: cluster 1 included Gs and G, whereas Y and Ys was grouped in cluster 2 by SDS-PAGE analysis but RAPD analysis grouped Ys and G in cluster 1 and Gs and Y in cluster 2. The range of genetic diversity observed among the strains affirms the potentiality of RAPD technique for identification and selection of distant parents for silkworm hybridization for high silk yield. Key words: Genetic variation, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), random amplified polymorphic DNA (RAPD), silkworm, cocoon.

Effect of substituting sp-element on half metallic ferromagnetism in NiCrSi Heusler alloy

The investigation of the electronic and magnetic properties of semi Heusler alloy, NiCrSi and alloys obtained by substituting Si with Ge and P (i.e. NiCrGe and NiCrP) has been presented. The present work aims to search the new candidates showing half metallic (HM) ferromagnetism using all-electron full potential linearized augmented plane wave (FPLAPW) method within generalized gradient approximation (GGA) formalism for exchange and correlation (XC) effects. We predict that these alloys are true half metallic ferromagnets (HMFs), showing an indirect band gap in minority density of states (DOS). This gap is largest in case of NiCrSi (0.91 eV). The substitution of sp-element in NiCrSi results in the minority band gap reduction. The main contribution in total magnetic moment comes from Cr- 3d states. Moreover, it has an integer value in present alloys as expected in accordance with the Slater-Pauling (SP) rule.

BMPs as Adsorptive Proteins for Ceramic Scaffolds

Body fluid permeability and blood compatibility of biomaterials are especially critical properties for regenerative bone therapy [1, 2]. To have a role in bone repair, biomaterials must have the adsorptive performance of various bone growth factors. The bone-inductive property of rabbit dentin was discovered in 1967 [3]. In our previous study, we have been researching the autograft of human demineralized dentin matrices (DDM) as a clinical study [4]. DDM is an acid-insoluble collagenous material. On the other hand, hydroxyapatite (HAp) is a mineralized material. Commercially available HAp block (APACERAM-AX®,85%-porosity with micropore) has been used as the artificial biomaterial in bone therapy [5]. Bone morphogenetic proteins (BMPs) are the strong hard tissue-inducing factors [6]. In this study, we investigated the existence of BMP-2 and -7, among proteins adsorbed to DDM and HAp, using immunoblottong analyses. The DDM granules and HAp blocks (64mm3) were implanted subcutaneously in 8-week-old Wistar rats, and sacrificed at 2 days after the implantation. Explanted DDM and HAp were homogenized by the ultrasonic procedure in phosphate-buffered saline (PBS) and the adsorbed proteins were separated on a 5-20% sodium dodecyl sulphate (SDS) polyacrylamide gradient gel by electrophoresis. For Western blotting, proteins in the gel were transferred to a polyvinylidene difluoride membrane and detected by anti-BMP-2 monoclonal antibody and anti-BMP-7 monoclonal antibody. BMP-2 and BMP-7 were detected as a major band at 50 kDa among proteins collected from the in vivo implanted DDM and HAp. BMP-2 was detected the second major band at 125 kDa in HAp and both BMP-2 and BMP-7 were detected the some minor bands in DDM and HAp. The bands of BMP-2 were stronger than those of BMP-7 in all. The DDM and HAp adsorbed BMP-2 and BMP-7. These results indicate that DDM is a useful bone substitute as much as HAp, adsorbed to the bone-inducing factors, in the bone engineering field.

Isolation and Partial Characterization of a Virulent Bacteriophage IHQ1 Specific for Aeromonas punctata from Stream Water

Aeromonas punctata is the causative agent of septicemia, diarrhea, wound infections, meningitis, peritonitis, and infections of the joints, bones and eyes. Bacteriophages are often considered alternative agents for controlling bacterial infection and contamination. In this study, we described the isolation and preliminary characterization of bacteriophage IHQ1 (family Myoviridae) active against the Gram-negative bacterial strain A. punctata. This virulent bacteriophage was isolated from stream water sample. Genome analysis indicated that phage IHQ1 was a double-stranded DNA virus with an approximate genome size of 25-28kb. The initial characterization of this newly isolated phage showed that it has a narrow host range and infects only A. punctata as it failed to infect seven other clinically isolated pathogenic strains, i.e., methicillin-resistant Staphylococcus aureus 6403, MRSA 17644, Acinetobacter 33408, Acinetobacter 1172, Pseudomonas aeruginosa 22250, P. aeruginosa 11219, and Escherichia coli. Proteomic pattern of phage IHQ1, generated by SDS-PAGE using purified phage particles, showed three major and three minor protein bands with molecular weights ranging from 25 to 70kDa. The adsorption rate of phage IHQ1 to the host bacterium was also determined, which was significantly enhanced by the addition of 10mM CaCl(2). From the single-step growth experiment, it was inferred that the latent time period of phage IHQ1 was 24min and a burst size of 626 phages per cell. Moreover, the pH and thermal stability of phage IHQ1 were also investigated. The maximum stability of the phage was observed at optimal pH7.0, and it was totally unstable at extreme acidic pH3; however, it was comparatively stable at alkaline pH11.0. At 37°C the phage showed maximum number of plaques, and the viability was almost 100%. The existence of Aeromonas bacteriophage is very promising for the eradication of this opportunistic pathogen and also for future applications such as the design of new detection and phage typing (diagnosis) methods. The specificity of the bacteriophage for A. punctata makes it an attractive candidate for phage therapy of A. punctata infections.

Eggplant polyphenol oxidase multigene family: Cloning, phylogeny, expression analyses and immunolocalization in response to wounding

Though polyphenol oxidase (PPO) genes from tomato and potato have been extensively studied, information about PPO genes in eggplant ( Solanum melongena) is lacking. The main objective of this study is to understand the structural and functional aspects of eggplant PPO genes. Six eggplant PPO genes ( SmePPO1–6) cloned by RACE and genome walking were found to be intronless and correspond to eight eggplant unigenes. Comprehensive sequence analyses indicated that the eggplant PPO genes exhibit considerable variation in the transit peptide regions, copper-binding domains and UTRs, and fall into two distinct structural classes. Further, PPO gene members appear to exist in clusters on eggplant chromosome 8 as seen in the case of tomato and potato PPOs. During normal growth and development, SmePPO1 and 2 are expressed in roots, whereas the transcript levels of all the eggplant PPO genes vary considerably in leaves, flowers and fruits. SmePPO1 was expressed in Escherichia coli as a GST fusion protein, and immunoblot using rabbit polyclonal antiserum to GST–SmePPO1 detected a major protein band (∼70 kDa) and a minor band (∼67 kDa) in eggplant fruit extract. Tissue printing indicated the predominant presence of PPO in the exocarp and the areas surrounding the seeds in the mesocarp of eggplant fruits. Immunolocalization of PPOs in eggplant infested with shoot-and-fruit borer revealed localization of the PPO at the site of infection in tender shoots and fruits, and further inside the mature tissues. The upregulation of eggplant PPO gene transcripts following mechanical injury shows that all the genes except SmePPO2 are induced in the fruit over 6 h. On the contrary, the transcripts of SmePPO2 and PPO3 are not detectable in the stem, and expression seems to be prominent over a 2 h period for SmePPO1 and SmePPO4–6. Our results show that eggplant PPO genes are structurally different, and are differentially expressed in various tissues of eggplant indicating their functional diversity.

Changes in antioxidative enzyme activities in cucumber plants with regard to biological control of root-knot nematode, Meloidogyne incognita with Cinnamomum cassia Crude Extracts

Cucumber plants were infected with the root-knot nematode Meloidogyne incognita and were then treated with Cinnamomum cassia crude extracts (CCE). The activities of antioxidative enzymes such as superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), and ascorbate peroxidase (APX, EC 1.11.1.11, class I peroxidase) were detected in the cucumber leaves. On day 28 after treatment of C. cassia (0, 1, 5, and 10 mg/mL), the relative galling formation decreased significantly in a dose-dependent manner. The C. cassia crude extracts also effectively inhibited the growth of M. incognita in soil and roots. The number of second-stage juveniles was significantly decreased as the concentration of the C. cassia crude extracts increased. Twenty-eight days after treatment with CCE, the SOD activities of plant leaves treated with 5 and 10 mg/mL CCE were greater than that of leaves treated with nematode (Ne) only. In addition, the CAT and ascorbate peroxidase (APX) activities increased as the concentration of CCE increased. The relative activities of the antioxidative enzymes decreased as the galling formation in the roots increased in response to M. incognita infection. Polyacrylamide gel electrophoresis (PAGE) with activity staining revealed active bands of SOD corresponding to at least five isozymes (93, 79, 71, 66, and 41 kDa), including three Fe-SOD bands (71, 66, and 41 kDa) and two Mn-SOD bands (93 and 79 kDa). Analysis of the cucumber leaves revealed one active band corresponding to the CAT isozyme (>97 kDa) on 10% native gels. At least four bands corresponding to APX were observed in 10% polyacrylamide, including one major band (>97 kDa) and three minor bands (79, 71, and 66 kDa). Compared with the leaves of cucumber plants that received other treatments, SOD (41 kDa) and APX (70 kDa) isozymes in the leaves of plants treated with Ne only showed intensified bands in PAGE gels.

Magnetically dead layers atsp-impurity-decorated grain boundaries and surfaces in nickel

With the help of ab initio electronic structure calculations, we study segregation of the $sp$ elements from the 13th--16th group and the third, fourth, and fifth period of the Periodic Table (i.e., Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, and Te) at the $\ensuremath{\Sigma}$5(210) grain boundary (GB) and (210) free surface (FS) in fcc ferromagnetic nickel, and analyze the geometric configuration and the distribution of magnetic moments at the GB and FS without and with impurities. Whereas there is a slight enhancement of magnetization at the clean GB and FS with respect to bulk nickel (3--7% and 24%, respectively), most of these impurities nearly kill or substantially reduce the magnetic moments at the FS and, when segregating interstitially at the GB (i.e., Si, P, S, Ge, As, and Se), they produce magnetically dead layers at the boundary. We demonstrate that the existence of magnetically dead layers is a common phenomenon at the $sp$-impurity-decorated GB and FS in nickel. It is caused by a strong hybridization of $sp$ states of the impurities with the $d$ states of nickel and a redistribution of electron states in both majority and minority bands.

Spectral, electron microscopic and chemical investigations of gamma-induced purple color zonings in amethyst crystals from the Dursunbey-Balıkesir region of Turkey

Amethyst crystals on matrix specimens from the Dursunbey-Balıkesir region in Turkey have five representative purple color zonings: dark purple, light purple, lilac, orchid, and violet. The purple color zonings have been analyzed with optical absorption spectra in the visible wavelength region, chemical full trace element analyses (inductively coupled plasma-atomic emission spectroscopy and inductively coupled plasma-mass spectroscopy), and scanning electron microscopic images with high magnification. It can be proposed that the production of the purple color in amethyst crystals is due to three dominant absorption bands centered at 375, 530, and 675 nm, respectively. In addition, the purple color zonings are also due to four minor absorption bands centered at 435, 480, 620, and 760 nm. X-ray diffraction graphics of the investigated amethyst crystals indicate that these crystals are composed of a nearly pure alpha-quartz phase and do not include any moganite silica phase and/or other mineral implications. Trace element analyses of the amethyst crystals show five representative purple color zonings, suggesting that the absorption bands can be mainly attributed to extrinsic defects (chemical impurities). However, another important factor that influences all structural defects in amethyst is likely to be the gamma irradiation that exists during amethyst crystallization and its inclusion in host materials. This gamma irradiation originates from the large underlying intrusive granitoid body in the region of amethyst formation. Irradiation modifies the valence values of the impurity elements in the amethyst crystals. It is observed that the violet-colored amethyst crystals have the most stable and the least reversible coloration when exposed to strong light sources. This situation can be related to the higher impurity content of Fe (2.50 ppm), Co (3.1 ppm), Ni (38 ppm), Cu (17.9 ppm), Zn (10 ppm), Zr (3.9 ppm), and Mo (21.8 ppm).

Spectroscopic survey of X-type asteroids

We present reflected light spectral observations from 0.4 to 2.5 μm of 24 asteroids chosen from the population of asteroids initially classified as Tholen X-type objects ( Tholen, 1984). The X complex in the Tholen taxonomy comprises the E, M and P classes which have very different inferred mineralogies but which are spectrally similar to each other, with featureless spectra in visible wavelengths. The data were obtained during several observing runs in the 2004–2007 years at the NTT, TNG and IRTF telescopes. Sixteen asteroids were observed in the visible and near-infrared wavelength range, seven objects in the visible wavelength range only, and one object in the near-infrared wavelength range only. We find a large variety of near-infrared spectral behaviors within the X class, and we identify weak absorption bands in spectra of 11 asteroids. Our spectra, together with albedos published by Tedesco et al. (2002), can be used to suggest new Tholen classifications for these objects. We describe 1 A-type (1122), 1 D-type (1328), 1 E-type (possibly, 3447 Burckhalter), 10 M-types (77, 92, 184, 337, 417, 741, 758, 1124, 1146 and 1355), 5 P-types (275, 463, 522, 909, 1902), and 6 C-types (50, 220, 223, 283, 517, and 536). In order to constrain the possible composition of these asteroids, we perform a least-squares search through the RELAB spectral database. Many of the best fits are consistent with meteorite analogue materials suggested in the published literature. In fact, we find that seven of the new M-types can be fit with metallic iron (or pallasite) materials, and that the low albedo C/P-type asteroids are best fitted with CM meteorites, some of which have been subjected to heating episodes or laser irradiation. Our method of searching for meteorite analogues emphasizes the spectral characteristics of brightness and shape, and de-emphasizes minor absorption bands. Indeed, faint absorption features like the 0.9 μm band seen on four newly classified M-type asteroids are not reproduced by the iron meteorites. In these cases, we have searched for geographical mixture models that can fit the asteroid spectrum, minor bands, and albedo. We find that a few percent (less than 3%) of orthopyroxene added to iron or pallasite meteorite, results in good spectral matches, reproducing the weak spectral feature around 0.9 μm seen on 92 Undina, 417 Suevia, and 1124 Stroobantia. For 337 Devosa, a mixture model that better reproduces its spectral behavior and the 0.9 μm feature is made with Esquel pallasite enriched with goethite (2%). Finally, we consider the sample of the X-type asteroids we have when we combine the present observations with previously published observations for a total of 72 bodies. This sample includes M and E-type asteroid data presented in Fornasier et al. (2008, 2010). We find that the mean visible spectral slopes for the different E, M and P Tholen classes are very similar, as expected. An analysis of the X-type asteroid distribution in the main belt is also reported, following both the Tholen and the Bus–DeMeo taxonomies ( DeMeo et al., 2009).

Kinetic properties of mouse pancreatic lipase-related protein-2 suggest the mouse may not model human fat digestion

Genetically engineered mice have been employed to understand the role of lipases in dietary fat digestion with the expectation that the results can be extrapolated to humans. However, little is known about the properties of mouse pancreatic triglyceride lipase (mPTL) and pancreatic lipase-related protein-2 (mPLRP2). In this study, both lipases were expressed in Pichia Pastoris GS115, purified to near homogeneity, and their properties were characterized. Mouse PTL displayed the kinetics typical of PTL from other species. Like mPTL, mPLRP2 exhibited strong activity against various triglycerides. In contrast to mPTL, mPLRP2 was not inhibited by increasing bile salt concentration. Colipase stimulated mPLRP2 activity 2- to 4-fold. Additionally, mPTL absolutely required colipase for absorption to a lipid interface, whereas mPLRP2 absorbed fully without colipase. mPLRP2 had full activity in the presence of BSA, whereas BSA completely inhibited mPTL unless colipase was present. All of these properties of mPLRP2 differ from the properties of human PLRP2 (hPLRP2). Furthermore, mPLRP2 appears capable of compensating for mPTL deficiency. These findings suggest that the molecular mechanisms of dietary fat digestion may be different in humans and mice. Thus, extrapolation of dietary fat digestion in mice to humans should be done with care.

Half-metallic properties of the Co 2Ti 1− xFe xGa Heusler alloys and Co 2Ti 0.5Fe 0.5Ga (0 0 1) surface

Electronic and magnetic properties of the bulk Co 2Ti 1− x Fe x Ga Heusler alloys and Co 2Ti 0.5Fe 0.5Ga (0 0 1) surfaces are studied within the framework of density functional theory using the augmented plane wave plus local orbital (APW+lo) approach. It will be shown that all alloys have the spin polarization of the ideal 100% value except the Co 2FeGa alloy with spin polarization about 98%. Co 2Ti 0.5Fe 0.5Ga is an example that is stable against the effects destroying the half-metallicity due to the position of the Fermi energy ( E F) in the middle of the minority band gap. The phase diagram obtained by ab-initio atomistic thermodynamics shows that in the higher limit of μ Ga three surfaces of FeGa, TiGa and TiFeGa are accessible in the Co 2Ti 0.5Fe 0.5Ga alloy but on decreasing μ Ga, the accessible region gradually moves towards FeGa termination. It is discussed that, at the ideal surfaces, half-metallicity of the alloy is lost, although the TiGa surface keeps high spin polarization (about 95%).