Search

Ultrathin films of YBa 2 Cu 3 O x with good crystallinity and high transition temperatures were prepared by modified off-axis sputtering. The surface morphology of films with thickness down to 2 nm has been studied by scanning electron microscopy and atomic force microscopy. The outgrowths were found to nucleate at the initial growing stage of films. Thus the surface quality of the initially grown layer turned out to be of practical importance in controlling and improving the film-surface morphology. The possible origins of the outgrowths have also been discussed. By employing a substrate with a very good surface and using a suitable deposition temperature, the nucleation of the outgrowths can be greatly suppressed and extremely smooth films up to hundreds nm thickness can be obtained.

Highly epitaxial thin films of YBCO have been obtained on silicon wafers using a Eu 2 CuO 4/ YSZ (yttrium-stabilized ZrO 2) double buffer. Our results showed that application of such a double buffer can significantly enhance the epitaxy of grown YBCO. It also leads to an excellent surface morphology. The average surface roughness was found less than 5 nm in a large range. The results of X-ray small angle reflection and positron spectroscpy demonstrate a very clear and flat interface between YBCO and buffer layers. The Eu 2 CuO 4/ YSZ double buffer could be promising for coating high-TC superconducting films on various reactive substrates.

A comparative theoretical investigation into the change in strength of the trigger-bond upon formation of the Na(+), Mg(2+) and HF complexes involving the nitro group of RNO₂ (R = -CH₃, -NH₂, -OCH₃) or the C = C bond of (E)-O₂N-CH = CH-NO₂ was carried out using the B3LYP and MP2(full) methods with the 6-311++G**, 6-311++G(2df,2p) and aug-cc-pVTZ basis sets. Except for the Mg(2+)⋯π system with (E)-O2N-CH = CH-NO₂ (i.e., C₂H₂N₂O₄⋯Mg(2+)), the strength of the trigger-bond X-NO₂ (X = C, N or O) was enhanced upon complex formation. Furthermore, the increment of bond dissociation energy of the X-NO₂ bond in the Na(+) complex was far greater than that in the corresponding HF system. Thus, the explosive sensitivity in the former might be lower than that in the latter. For C₂H₂N₂O₄⋯Mg(2+), the explosive sensitivity might also be reduced. Therefore, it is possible that introducing cations into the structure of explosives might be more efficacious at reducing explosive sensitivity than the formation of an intermolecular hydrogen-bonded complex. AIM, NBO and electron density shifts analyses showed that the electron density shifted toward the X-NO₂ bond upon complex formation, leading to a strengthened X-NO₂ bond and possibly reduced explosive sensitivity.

Under the premise what we have known bacterial artificial chromosome(BAC)clone sequence information and gene annotation predicted in the Chinese Merino sheep major histocompatibility complex (MHC) region, the digested fragments from 6 BAC clones that were located in the MHC region of the Chinese Merino sheep genome BAC library, which were used to screen the cDNA library using plaque in situ hybridization as probes. The full length of positive cDNA clones (sequences) isolated were completely sequenced, and the sequences obtained were aligned with the corresponding known sequence information and the BAC clones with gene annotation. Meanwhile, the sequence similarity was searched in NCBI Blastn database. This work aimed at verification of accuracy of the gene annotation results and initial analysis of gene (sequence) function. At last, 27 positive cDNA clones (sequences) in total were screened through two runs of hybridization. It was also found that these sequences could be positioned in the corresponding BAC clones, and 25 sequences were located in exon area of the annotated gene. It was verified that 23 sequences had the highest sequence similarity with those in the Bos taurus by searching against the NCBI Blastn database; moreover, the function of these sequences were closely relate to immunology.

To elucidate the mechanism of angiogenesis after cerebral ischemia/reperfusion (I/R) in the aged rats by observing the changes in expressions of basic fibroblast growth factor (bFGF) and transformation growth factor-β1 (TGF-β1).Young Sprague-Dawley (SD) rats were classified into groups by random digits table, and aged SD rats were stratified by different body weight. Rats were randomly divided into groups of sham operation, ischemia (I) 3 hours, I/R 1, 3, 6, 12 days, with 6 rats in each group. Focal cerebral I/R model was reproduced by intraluminal filament technique. Microvessel density (MVD) of brain tissue, sum area of lumens were observed, and the expressions of bFGF protein, TGF-β1 protein and TGF-β1 mRNA were assessed with immunohistochemistry and hybridization in situ.MVD in young model group began to increase at I 3 hours, peaking at I/R 6 days, maintained up to I/R 12 days. MVD in aged model group began to descend at I 3 hours and continued to I/R 12 days. Sum area of lumens in young model group increased markedly at I/R 1 day, gradually lowered at I/R 1-6 days, and increased obviously again at I/R 12 days. Sum area of lumens in aged model group reached peak at I/R 1 day, gradually decreased subsequently. MVD in aged sham operation group were higher than that in young sham operation group (6.88±1.60 vs. 5.50±1.53, P0.01). MVD and sum area of lumens in aged model group at I/R 1, 3, 6, 12 days were lower than young model group. Expressions of bFGF protein, TGF-β1 protein in young and aged model group were both gradually up-regulated, all of them reaching peak at I/R 3 days, and lowered gradually at I/R 3-12 days subsequently. Expressions of bFGF protein (grey level) in both aged sham operation group and those of model group at I 3 hours, I/R 1, 3, 12 days were lower than those of young sham operation and those of the model group at the same time points (176.80±5.10 vs. 172.82±1.53, 171.81±2.43 vs. 167.85±2.41, 167.99±5.51 vs. 164.90±2.15, 152.98±4.11 vs. 150.75±1.11, 165.67±3.55 vs. 161.73±1.29, P0.05 or P0.01). Expressions of TGF-β1 protein (grey level) in both aged sham operation and those of model group at I 3 hours, I/R 1, 3, 6, 12 days were all lower than those of young sham operation and those of model group at the same time points (182.69±3.12 vs. 176.13±4.08, 176.89±2.30 vs. 170.56±7.47, 171.74±2.70 vs. 165.43±2.91, 157.17±5.20 vs. 150.43±4.28, 161.72±4.81 vs. 155.37±2.92, 167.69±2.18 vs. 160.28±3.59, all P0.01). TGF-β1 mRNA expressions in both young model group and aged model group reached peak at I/R 1 day, gradually lowered subsequently. Expressions of TGF-β1 mRNA (gray level) in both aged sham operation and those of model group at I 3 hours, I/R 3, 6, 12 days were lower than those of young sham operation and also model group at the same time points (176.51±9.52 vs. 169.09±5.08, 176.75±5.74 vs. 165.36±4.78, 177.33±5.68 vs. 165.25±8.14, 178.46±4.91 vs. 170.51±4.29, 203.95±4.51 vs. 181.98±5.59, all P0.01).Angiogenesis is obviously weak after cerebral I/R in the aged, and the mechanism of which might be related to the down-regulation of expressions of bFGF protein, TGF-β1 protein and TGF-β1 mRNA. Aging factor may be one of the main reasons which induce the down regulation of expressions mentioned above.

The stationary properties of high- T c ramp type Josephson junctions with a graded Y 1-x Pr x Ba 2 Cu 3 O y barrier have been studied. In such a structure the composition of the Y 1-x Pr x Ba 2 Cu 3 O y barrier is continuely changed as x increasing from 0 to 1 at one side of the PrBCO barrier and vice verse at the other side. The critical current of these junctions showed a nearly linear dependence on the temperature. The experimental results were discussed in comparing with theoretical models.

La0.7Sr0.3MnO3 (LSMO) film exhibits certain unique properties which make it an ideal material for heterostructure-based multifunctional devices. In this paper, La0.7Sr0.3MnO3 thin films were grown epitaxially on SrTiO3, LaAlO3(LAO) and (LaAlO3)0.3-(SrAl0.5Ta0.5O3)0.7(LSAT) substrates, and their structural, electrical, magnetic and optical properties were examined and compared, aiming at revealing and explaining the effects of substrate on fundamental physical properties of LSMO films. Results show that (i) the effects of substrate materials on the electrical conductivity and paramagnetic–ferromagnetic transition temperature of the LSMO films could be ignored, and (ii) the LSMO film on LAO substrate has much higher coercive field and slower photoinduced relaxation process than other samples. This unusual behavior observed in the LSMO film on the LAO substrate could be related to the nature of the LAO substrate itself, on which the LSMO film showed different easy magnetization direction, and the film also exhibited relatively poor crystalline quality due to the twin domain structure of LAO crystal. Our results may help to understand the substrate-related electrical, magnetic and optical properties for perovskite manganite films.

To study the protective effect of Naomaitong on inflammatory cascade response after focal cerebral ischemia reperfusion in aged rats.We duplicated focal cerebral ischemia model with MCAO, with ischemia 3 h and I/R 1, 3, 6, 12 d points. The effect of Naomaitong on the nervous dysfunction score, the water content of cerebral constitution and the expression of TNF-alpha, VCAM-1, ICAM-1 and its mRNA were observed, and the group with nimodipine was as control.The nervous dysfunction score (I/R1, 3, 6 d), the water content of cerebral constitution (all the time points), the expression of TNF-alpha, VCAM-1 (I 3 h, I/R 1, 3, 6 d), ICAM-1 (I 3 h,I/R 1, 3, 6 d) and its Mrna (all the time points) in model group were higher than those of the sham-operated group; The nervous dysfunction score, the water content of cerebral constitution (I/R 3, 6, 12 d), the expression of TNF-alpha, VCAM-1 (I 3 h, I/R 1, 3 d), ICAM-1 and its mRNA (I 3 h, I/R 1, 3 d) in model group were decreased compared with that of model group. The nervous dysfunction score (I/R 6, 12 d), the expression of TNF-alpha, ICAM-1 (I/R 1d) and its mRNA (I/R 1, 3 d) in Naomaitong group were higher than that of Nimodipine group.Naomaitong could protect brain cell from damage after focal cerebral ischemia reperfusion injury by inhibiting the expression of TNF-alpha, adhesion molecule.

Microstructural study has been carried out on the YBa2Cu3O 7-δ (YBCO) thin films grown on (305) SrTiO3 (STO) substrates. The results show that the YBCO films are coherently tilted with the c-axis parallel to the [001] direction of STO. Small antidomains are nucleated at the initial growth stage. When the film thickness increases, antidomains disappear leading to the formation of single domain thin films. Some particles are observed above the defective substrate surface, but the film with the favorable orientation suppresses their further growth.

To investigate the changes in expression of tumor necrosis factor-alpha(TNF-alpha), vascular cellular adhesive molecule-1 (VCAM-1), intercellular adhesion molecular-1 (ICAM-1) and its mRNA expression, and the pathogenetic mechanism of cerebral ischemia/reperfusion(I/R) in elderly.Thirty six male young SD rats (5-6 months old) and 36 male aged SD rats (20-21 months old) were randomly divided into young sham operated group, young model group, aged sham operated group and aged model group, respectively. The two model groups were randomly divided into ischemia 3 hours (I 3 h), I/R 1, 3, 6, 12 days groups. There were 6 rats in each group. Focal cerebral I/R model was replicated with middle cerebral artery occlusion (MCAO). The changes of the nervous dysfunction score, the water content of cerebral constitution and the expression of TNF-alpha, VCAM-1, ICAM-1 and ICAM-1 mRNA were observed at each time point.The expression of TNF-alpha in the aged sham operated group were higher than that of the young sham operated group. The nervous dysfunction score (I 3 h and I/R 1-12 d), the water content of cerebral constitution (I/R 1-6 d), the expression of TNF-alpha (I 3 h and I/R 1-6 d), VCAM-1 (I 3 h and I/R 1 d), ICAM-1 (I 3 h and I/R 1-6 d) and ICAM-1 mRNA (I 3 h and I/R 1-12 d) in young model group and aged model group were higher than those of the young sham operated group and the aged sham operated group respectively. The nervous dysfunction score (I 3 h, I/R 6 d), the expression of TNF-alpha (I/R 1, 3 d), VCAM-1 (I/R 3, 6 d), ICAM-1 (I 3 h, I/R 1 d) and ICAM-1 mRNA (I/R 1-6 d) in aged model group were higher than that of young model group.The cerebral I/R injury is correlated with the up regulation of TNF-alpha, VCAM-1,ICAM-1 and its mRNA expression. The cerebral I/R injury of aged rats is more serious than that of young rats which might be associated with up regulation of TNF-alpha, adhesion molecules expression with aging.

The antiinflammatory activity of Terminalia catappa leaves ethanolic extract was studied using 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema in acute and chronic models. A bioassay-oriented fractionation procedure showed that the activity concentrates in the chloroform fraction. Ursolic acid (1) and 2alpha,3beta,23-trihydroxyurs-12-en-28-oic acid (2), isolated from the chloroform fraction, exhibited strong antiinflammatory activities. The results suggest that the triterpenic acids 1 and 2 are responsible for the antiinflammatory activity of T. catappa leaves.

Day 3 thymectomy (D3Tx) leads to a paucity of CD4+CD25+ suppressor T cells, a loss of peripheral tolerance, and the development of organ-specific autoimmune disease in adult mice. Importantly, D3Tx does not lead to autoimmune disease in all mouse strains, indicating that this process is genetically controlled. Previously, we reported linkage of D3Tx-induced autoimmune ovarian dysgenesis (AOD) and its intermediate phenotypes, antiovarian autoantibody responsiveness, oophoritis, and atrophy, to five quantitative trait loci (QTL), designated Aod1 through Aod5. We also showed interaction between these QTL and H2 as well as Gasa2, a QTL controlling susceptibility to D3Tx-induced autoimmune gastritis. To physically map Aod1, interval-specific bidirectional recombinant congenic strains of mice were generated and studied for susceptibility to D3Tx-induced AOD. Congenic mapping studies revealed that Aod1 controls susceptibility to oophoritis and comprises two linked QTL with opposing allelic effects. Aod1a resides between D16Mit211 (23.3 cM) and D16Mit51 (66.75 cM) on chromosome 16. Aod1b maps proximal of Aod1a between D16Mit89 (20.9 cM) and D16Mit211 (23.3 cM) and includes the candidate genes stefin A1, A2, and A3 (Stfa1-Stfa3), inhibitors of cathepsin S, a cysteine protease required for autoantigen presentation, and the development of autoimmune disease of the salivary and lacrimal glands following D3Tx. cDNA sequencing revealed the existence of structural polymorphisms for both Stfa1 and Stfa2. Given the roles of cathepsins in Ag processing and presentation, Stfa1 and Stfa2 alleles have the potential to control susceptibility to autoimmune disease at the level of both CD4+CD25+ suppressor and CD4+CD25− effector T cells.

In vivo intoxication withBordetella pertussistoxin (PTX) elicits a variety of physiological responses including a marked leukocytosis, disruption of glucose regulation, adjuvant activity, alterations in vascular function, hypersensitivity to vasoactive agents, and death. We recently identifiedBphs, the locus controlling PTX-induced hypersensitivity to the vasoactive amine histamine, as the histamine H1receptor (Hrh1). In this studyBphscongenic mice and mice with a disruptedHrh1gene were used to examine the role ofBphs/Hrh1in the genetic control of susceptibility to a number of phenotypes elicited following in vivo intoxication. We report that the contribution ofBphs/Hrh1to the overall genetic control of responsiveness to PTX is restricted to susceptibility to histamine hypersensitivity and enhancement of antigen-specific delayed-type hypersensitivity responses. Furthermore, the genetic contribution ofBphs/Hrh1to vasoactive amine sensitization is specific for histamine, since hypersensitivity to serotonin was unaffected byBphs/Hrh1. Bphs/Hrh1also did not significantly influence susceptibility to the lethal effects, the leukocytosis response, disruption of glucose regulation, and histamine-independent increases in vascular permeability associated with in vivo intoxication. Nevertheless, significant interstrain differences in susceptibility to the lethal effects of PTX and leukocytosis response were observed. These results indicate that the phenotypic variation in responsiveness to PTX reflects the genetic control of distinct intermediate phenotypes rather than allelic variation in genes controlling overall susceptibility to intoxication.

The electric field and photo illumination effects in thin films of La0.39Pr0.24Ca0.37MnO3(LPCMO)/SrTiO3 with different thicknesses (15, 40 and 120 nm) have been systematically investigated. X-ray diffraction measurements demonstrate that these grown films are epitaxial and c axis oriented. Due to strain relaxation, these films are in different strain states. It is found that the strain state can greatly change not only the electrical properties but also the responses to external perturbations. The thinner film experiences a larger tensile in-plane strain and has a more robust insulating state. The low-temperature insulating state in the 120 nm sample is readily destroyed by a small electric field or light illumination without a bias voltage. Both the critical light density and the critical electric field used to collapse the insulating state in the 40 nm LPCMO film are much larger than those in the 120 nm sample. It is revealed that the bias electric field and light illumination play complementary roles. Light illumination can reduce the critical bias electric field. The 15 nm sample exhibits a robust insulating state, which cannot be destroyed by a combination of a bias voltage of 200 V (E = 4 × 105 V m−1) and light illumination (λ = 532 nm, P = 2 mW cm−2). Large transient photoconductivity has been observed in the 40 nm sample under low bias voltages and in the 15 nm sample under all bias voltages. The observed transient photoconductivity and persistent photoconductivity are believed to have different origins.

Barrier heights in heterojunctions composed of Nd0.7Sr0.3MnO3 and Nb doped SrTiO3 have been characterized with current–voltage characteristics by using various methods. It is revealed that an inappropriate assumption of the transport mechanism would usually lead to the underestimation of the barrier height. Provided that the transport mechanism is correctly identified the barrier height deduced with current–voltage characteristics could be in accordance with Anderson's model and typical internal photoemission results. It is suggested that for manganite–titanate heterojunctions introducing the ideality factor in the thermionic emission saturation current density equation might largely counteract the underestimation of the barrier height.

Sm-Nd isotope systematics of scheelite is becoming a powerful geochronometer for dating the Au and W ore deposits. However, Sm-Nd isotopic analysis of scheelite is relatively difficult due to the formation of large amounts of tungstic acid (H2WO4) precipitates during the conventional acid decomposition of scheelite. In this study, both the low temperature attack and Teflon bomb acid dissolution methods for Sm-Nd isotope analysis of scheelite have been thoroughly investigated. It has been shown that, for both low temperature attack and Teflon bomb methods, although a large amount of tungstic acid precipitate remains during the 2.5 M HCl acidification process prior to cation exchange separation, only less than 10% of the Sm and Nd remains in the tungstic acid precipitate. On the other hand, it has been found that, for isotope dilution analysis, the spike-sample isotopic equilibration was only completely achieved for the Teflon bomb method and not completely achieved for the low temperature attack method, indicating that the low temperature attack method has possibly not liberated all the rare earth elements (REEs) from the scheelite crystal structure. Consequently, for high precision scheelite Sm-Nd dating purposes, the complex Teflon bomb rather than the simple low temperature attack method should be used in order to completely digest scheelite samples; alternatively, since it has been found that the tungstic acid precipitate formed during the acid dissolution process can be completely dissolved by self-purified low-blank 30% NaOH, a simple low temperature attack method combined with low-blank 30% NaOH dissolution of the remaining tungstic acid precipitate can also possibly be used to completely dissolve the scheelite sample for Sm-Nd isotopic analysis.

Pure maghemite (γ-Fe 2 O 3 ) nanoparticles were prepared via so-called homogeneous co-precipitation method using urea and ammonia as precipitation agent for ferrous and ferric ions at ambient temperature. X-ray diffraction, energy dispersive spectrometer and Fourier transform infrared spectrophotometer revealed that the obtained product was pure γ-Fe 2 O 3 . Transmission electron microscope investigations showed the morphology of the nanoparticles were of approximate spherical shape with an average diameter of 11 nm. Magnetic measurements showed that resulting iron oxide nanopowder exhibited a characteristic ferromagnetism with a maximum saturation magnetisation of 66.83 emu/g.

This paper reports a modified digestion method for the determination of platinum group elements (PGEs) in geological samples. Samples are first digested by HF in a custom made 120 ml PTFE beaker on a hot plate to remove silicates. The dried residue is then digested with HF + HNO3 at 190 °C for about 48 h after the beaker is sealed in a stainless steel pressure bomb. Although only HF + HNO3 are used for sample digestion at relatively low temperature, ultramafic rocks with refractory minerals can be effectively decomposed by this method. Analytical results for CCRMP (CANMET, Ottawa, Canada) certified reference materials WGB-1 (gabbro), UMT-1 (ultramafic ore tailings), WPR-1 (peridotite) and WMS-1(Massive Sulphide), agree well with the certified values. The proposed method significantly simplifies the sample digestion procedures for PGE analysis compared to those used previously.

A simple and highly selective analytical method is developed for Re–Os dating in hydrothermal pyrites. Pyrites were first digested with HNO3 in a 120 ml Carius tube. The released additional gas and a small portion of volatile Os (∼6% of total Os) were collected by 10 mol l−1 of HCl in an ice-water bath. After the sulfides were totally reacted with HNO3, the HCl solution containing all the released Os was transferred back to the Carius tube. The sample was further digested in aqua regia at 200 °C for about 10 h in a sealed Carius tube. Because prior digestion in an open Carius tube removed the additional gas, this improved technique allows increasing the sample mass to about 3 g, which is vital for Re–Os dating in Re and Os poor hydrothermal pyrites. Os was separated from the matrix by distillation and Re by anion exchange resin. The results obtained for molybdenite reference materials, JDC and HLP mixed with 3 g pyrite are in good agreement with certified values. Despite very low concentrations of Re and Os, the pyrite yields excellent repeatability and can be used for Re and Os poor hydrothermal pyrites.

Histamine is a ubiquitous regulator of diverse physiologic processes including inflammation, immune modulation and neurotransmission. Four subtypes of histamine receptors are currently recognized and genetic and pharmacological studies have shown that the H1 and H2 receptors play a role in susceptibility to experimental allergic encephalomyelitis (EAE), the primary autoimmune model of multiple sclerosis. Histamine H3 receptor (H3R), which is not expressed in hematopoietic cells, is a presynaptic auto- and hetero-receptor. Here we show that H3RKO mice develop significantly more severe acute phase clinical disease and neuropathology compared to wild-type controls. In H3RKO mice this is preceded by disruption of the blood brain barrier and increased chemokine/chemokine receptor expression in peripheral T-cells. These data are consistent with inhibition of H3R-mediated neurogenic control of cerebrovascular tone and T-cell function. Additionally, genetic studies indicate that an H3R polymorphism leading to differential expression of H3R isoforms underlies eae8, a locus controlling disease associated weight loss, a phenotype known to be regulated by central H3R activity.

Arnold et al . ([ 1 ][1]) reported Mo isotope compositions of mid-Proterozoic black shale, which were different from those of euxinic sediments in the Black Sea. On the basis of a mass balance model calculation, they claimed that “the area of oxic sedimentation in the mid-Proterozoic oceans was

By measuring the Sm-Nd and Rb-Sr isotopic compositions of harzburgite and gabbro from Shimian ophiolite suite, we got the whole rock Sm-Nd isochron age of (938±30) Ma (2σ), and the eNd of 7.6±0.8 (2σ), which shows that the ophiolite was formed at the Early Neoproterozoic. The obvious change (0.70209–0.70708) of ISr values of the ophiolite is caused by the meteoric hydrothermal alteration. The high eNd values indicate that the primitive magma was derived from the intense depleted mantle reservoir. It is suggested that this area was in a back-arc basin environment during the Early Neoproterozic.

Highly epitaxial thin films of Pr0.7Sr0.3MnO3 were grown on (100) SrTiO3 single crystal substrates by laser ablation. Similar to other manganite compounds, these Pr0.7Sr0.3MnO3 films exhibited remarkable magnetoresistance. Application of electric currents could induce a remarkable reduction in resistivity, demonstrating a strong electroresistance effect. The ratio of the resistance variation, ER=[R(0)−R(I)]/R(I), is about 33% at metal-insulator transition temperature. Using a planar field effect configuration, significant field modulation of the metal-insulator transition was achieved. The observed field effects were discussed based on the strong interactions between carrier spins and localized spins in Mn ions, as well as the percolative mechanism of phase separation.

The Tengchong volcanic field north of the Burma arc comprises numerous Quaternary volcanoes in the southeastern margin of the Tibetan Plateau. The volcanic rocks are grouped into four units (1–4) from the oldest to youngest. Units 1, 3 and 4 are composed of olivine trachybasalt, basaltic trachyandesite and trachyandesite, and Unit 2 consists of hornblende dacite. The rocks of Units 1, 3, and 4 form a generally alkaline suite in which the rocks plot along generally linear trends on Harker diagrams with only slight offset from unit to unit. They contain olivine phenocrysts with Fo values ranging from 65 to 85 mol% and have Cr-spinel with Cr# ranging from 23 to 35. All the rocks have chondrite-normalized REE patterns enriched in LREE and primitive mantle-normalized trace element patterns depleted in Ti, Nb and Ta, but they are rich in Th, Ti and P relative to typical arc volcanics. Despite minor crustal contamination, 87Sr/86Sr ratios (0.706–0.709), eNd values (−3.2 to −8.7), and eHf values (+4.8 to −6.4) indicate a highly heterogeneous mantle source. The Pb isotopic ratios of the lavas (206Pb/204Pb = 18.02–18.30) clearly show an EMI-type mantle source. The underlying mantle source was previously modified by subduction of the Neo-Tethyan oceanic and Indian continental lithosphere. The present heterogeneous mantle source is interpreted to have formed by variable additions of fluids and sediments derived from the subducted Indian Oceanic lithosphere, probably the Ninety East Ridge. Magma generation and emplacement was facilitated by transtensional NS-trending strike-slip faulting.