Gate-Tunable Spin-Charge Conversion and the Role of Spin-Orbit Interaction in Graphene.

The small spin-orbit interaction of carbon atoms in graphene promises a long spin diffusion length and the potential to create a spin field-effect transistor. However, for this reason, graphene was largely overlooked as a possible spin-charge conversion material. We report electric gate tuning of the spin-charge conversion voltage signal in single-layer graphene. Using spin pumping from an yttrium iron garnet ferrimagnetic insulator and ionic liquid top gate, we determined that the inverse spin Hall effect is the dominant spin-charge conversion mechanism in single-layer graphene. From the gate dependence of the electromotive force we showed the dominance of the intrinsic over Rashba spin-orbit interaction, a long-standing question in graphene research.

Experimental Demonstration of Room-Temperature Spin Transport in n-Type Germanium Epilayers.

We report an experimental demonstration of room-temperature spin transport in n-type Ge epilayers grown on a Si(001) substrate. By utilizing spin pumping under ferromagnetic resonance, which inherently endows a spin battery function for semiconductors connected with a ferromagnet, a pure spin current is generated in the n-Ge at room temperature. The pure spin current is detected by using the inverse spin-Hall effect of either a Pt or Pd electrode on n-Ge. From a theoretical model that includes a geometrical contribution, the spin diffusion length in n-Ge at room temperature is estimated to be 660 nm. Moreover, the spin relaxation time decreases with increasing temperature, in agreement with a recently proposed theory of donor-driven spin relaxation in multivalley semiconductors.

Characterization and evolutionary analysis of tributyltin-binding protein and pufferfish saxitoxin and tetrodotoxin-binding protein genes in toxic and nontoxic pufferfishes.

Understanding the evolutionary mechanisms of toxin accumulation in pufferfishes has been long-standing problem in toxicology and evolutionary biology. Pufferfish saxitoxin and tetrodotoxin-binding protein (PSTBP) is involved in the transport and accumulation of tetrodotoxin and is one of the most intriguing proteins related to the toxicity of pufferfishes. PSTBPs are fusion proteins consisting of two tandem repeated tributyltin-binding protein type 2 (TBT-bp2) domains. In this study, we examined the evolutionary dynamics of TBT-bp2 and PSTBP genes to understand the evolution of toxin accumulation in pufferfishes. Database searches and/or PCR-based cDNA cloning in nine pufferfish species (6 toxic and 3 nontoxic) revealed that all species possessed one or more TBT-bp2 genes, but PSTBP genes were found only in 5 toxic species belonging to genus Takifugu. These toxic Takifugu species possessed two or three copies of PSTBP genes. Phylogenetic analysis of TBT-bp2 and PSTBP genes suggested that PSTBPs evolved in the common ancestor of Takifugu species by repeated duplications and fusions of TBT-bp2 genes. In addition, a detailed comparison of Takifugu TBT-bp2 and PSTBP gene sequences detected a signature of positive selection under the pressure of gene conversion. The complicated evolutionary dynamics of TBT-bp2 and PSTBP genes may reflect the diversity of toxicity in pufferfishes.

Characterization of 5-hydroxytryptamine-induced contraction and acetylcholine-induced relaxation in isolated chicken basilar artery.

The aim of the present study was to clarify the responsiveness of the chicken basilar artery to 5-hydroxytryptamine (5-HT) and acetylcholine (ACh) and to characterize the related receptor subtypes in vitro. Basilar arteries were obtained from freshly slaughtered broiler chickens. The 5-HT induced concentration-dependent contraction of the arteries. The concentration-response curves for 5-HT were shifted 30-fold to the right by methiothepin (a 5-HT(1) and 5-HT(2) receptor antagonist) and 3-fold to the right by ketanserin (a 5-HT(2) receptor antagonist). In the presence of ketanserin, the concentration-response curve for 5-HT was shifted 10-fold to the right by methiothepin. The pA(2) value for methiothepin was 8.26. The ACh induced concentration-dependent relaxation under conditions of precontraction by 5-HT. The concentration-response curve for ACh was shifted to the right by atropine [a nonselective muscarinic (M) receptor antagonist] and hexahydro-sila-difenidol hydrochloride, a p-fluoroanalog (pFHHSiD, an M(3) receptor antagonist), but not by pirenzepine (an M(1) receptor antagonist) or methoctramine (an M(2) receptor antagonist). The pA(2) value for pFHHSiD was 7.55. Nω-Nitro-l-arginine (a nitric oxide synthase inhibitor) inhibited ACh-induced relaxation by approximately 50%. These results suggest that 5-HT induces contraction via activation of 5-HT(1) and 5-HT(2) receptors and that ACh induces relaxation via activation of the M(3) receptor. The 5-HT(1) receptor might play a dominant role in 5-HT-induced contraction. One of the factors involved in ACh-induced relaxation is probably nitric oxide released from endothelial cells.

Characteristics and outcome of suspected cerebrovascular disease in dogs: 66 cases (2009-2016).

OBJECTIVES: To characterise the clinical signs of suspected cerebrovascular disease in dogs. MATERIALS AND METHODS: Medical records of one hospital were searched from November 2009 to December 2016 for dogs that suffered of cerebrovascular disease. We diagnosed cerebrovascular disease based on acute onset, clinical signs and magnetic resonance imaging findings. The medical history, clinical signs, concurrent disease, area of infarction, cerebrospinal fluid results, month at onset and outcome were investigated in the cerebrovascular disease group and in a control group (dogs with brain disorders other than cerebrovascular disease). RESULTS: A total of 122 CVD cases were extracted from the 5312 patients that visited during the study period. Of these 122 cases, 66 (1.2%) matched the subject selection criteria of our study and were included in the analysis. Forebrain infarction was observed in 51 of 66 cases, of which 24 (47.1%) suffered from seizures. The number of dogs diagnosed with cerebrovascular disease was disproportionately high in August (nine of 59 cases) and December (13 of 59 cases). In the outcome survey, deterioration was observed in 11 of 55 cases. CLINICAL SIGNIFICANCE: Seizure is an important clinical sign of cerebrovascular disease in dogs. There was a significant seasonal variation in the number of dogs diagnosed with cerebrovascular disease in Japan. Clinical features observed in this report differ from those of previous reports and highlight the need for additional research in this area.

Investigation of the thermal tolerance of silicon-based lateral spin valves.

Improvement in the thermal tolerance of Si-based spin devices is realized by employing thermally stable nonmagnetic (NM) electrodes. For Au/Ta/Al electrodes, intermixing between Al atoms and Au atoms occurs at approximately 300 °C, resulting in the formation of a Au/Si interface. The Au-Si liquid phase is formed and diffuses mainly along an in-plane direction between the Si and AlN capping layers, eventually breaking the MgO layer of the ferromagnetic (FM) metal/MgO electrodes, which is located 7 µm away from the NM electrodes. By changing the layer structure of the NM electrode from Au/Ta/Al to Au/Ta, the thermal tolerance is clearly enhanced. Clear spin transport signals are obtained even after annealing at 400 °C. To investigate the effects of Mg insertion in FM electrodes on thermal tolerance, we also compare the thermal tolerance among Fe/Co/MgO, Fe/Co/Mg/MgO and Fe/Co/MgO/Mg contacts. Although a highly efficient spin injection has been reported by insertion of a thin Mg layer below or above the MgO layer, these thermal tolerances decrease obviously.

Serum somatostatin in early-stage Parkinson's disease.

OBJECTIVE: To compare levels of plasma digestive hormones in patients with and without nausea or vomiting during initial treatment of early-stage Parkinson's disease (PD). METHODS: This was a 3-week, open-label, randomized study of treatment with an antiparkinson drug in untreated PD patients. We measured the levels of plasma digestive hormones before (baseline) and 3 weeks after administration of an antiparkinson drug. RESULTS: Mean value of serum somatostatin at baseline was significantly increased in PD patients compared with the control group (P < 0.01). Serum somatostatin levels were significantly increased after treatment in subjects who experienced nausea or vomiting (P < 0.01). However, significant increase in serum somatostatin levels after treatment was not observed in PD patients without nausea or vomitting. CONCLUSION: Serum somatostatin in early-stage PD patients before treatment was increased compared with healthy subjects. The nausea and vomiting induced by antiparkinson drugs may be related to uncontrolled somatostatin secretion through central vagus nerve dysfunction.

[Combined aortic root replacement and pectus excavatum correction in Marfan's syndrome].

A 53-year-old man with Marfan's syndrome was admitted for repair of annulo-aortic ectasia (58 mm). He had also severe pectus excavatum. The skin was incised along the sternal midline. The pectoral muscles were detached laterally. After the perichondrium and costal cartilages were resected bilaterally. the left-sided intercostal muscles and perichondrial sheaths were divided 3 cm lateral to the sternum. To place the retractor in parasternal position, excellent exposure of the heart and aortic root was enabled. The aortic root was replaced with a Carboseal graft. Chest wall reconstructions was completed by modified Ravitch procedure with Gore-tex sheet The patient was discharged after an uneventful recovery on postoperative day 14.

Enhancement of activated beta1-integrin expression by prostaglandin E2 via EP receptors in isolated human coronary arterial endothelial cells: implication for the treatment of Kawasaki disease.

OBJECTIVE: Plasma prostaglandin E(2) (PGE(2)) levels are markedly elevated in acute Kawasaki disease (KD). We evaluated the function of the EP receptors in the expression of activated beta(1)-integrin stimulated by PGE(2) in human coronary arterial endothelial cells (HCAEC). METHODS: We determined the mRNA expression of the PGE(2) receptors, EP receptors (EP(1-4)) in HCAEC by RT-PCR and protein expression by Western blotting. We evaluated the function of the EP receptors in the expression of activated beta(1)-integrin stimulated by PGE(2) in HCAEC, using antagonists and agonists of the EP receptors, by flow cytometry. RESULTS: RT-PCR revealed mRNAs for all four EP receptors in HCAEC. Western blotting demonstrated EP(1), EP(2) and EP(3) expression in HCAEC. The EP(2) and EP(3) agonists enhanced the expression of activated beta(1)-integrin in HCAEC. The potency of the EP(2) agonist was significantly greater than that of the EP(3) agonist. Pretreatment with the EP(1), EP(2) and EP(3) antagonists inhibited the expression of activated beta(1)-integrin induced by PGE(2) in HCAEC. The potency of the EP(2) antagonist was significantly greater than that of the EP(1) and EP(3) antagonists. CONCLUSIONS: Our results suggest that PGE(2) mainly induces the activation of beta(1)-integrins via the EP(2) receptor in HCAEC. Our results further suggest that the EP(2) antagonist modulates the inflammatory response during KD vasculitis.

Characterization of bradykinin-induced endothelium-independent contraction in equine basilar artery.

We investigated the effect of bradykinin (BK) on isolated equine basilar arterial rings with and without endothelium. BK induced concentration-dependent contraction of resting arterial rings and no relaxation when the rings were precontracted by prostaglandin F(2alpha). The maximal response and pD(2) value were 161.2 +/- 28.1% (to 60 mm KCl-induced contraction) and 8.24 +/- 0.25 respectively. The cumulative concentration-response curve for BK was not shifted to the right by des-Arg(9)-[Leu(8)]-BK (a B(1)-receptor antagonist), HOE140 (a B(2)-receptor antagonist) or NPC567 (another B(2)-receptor antagonist). In four of six basilar arteries, NPC567 induced concentration-dependent contraction. Indomethacin (a cyclooxygenase inhibitor), nordihydroguaiaretic acid (a lipoxygenase inhibitor), quinacrine (a phospholipase A(2) inhibitor), tetrodotoxin (a selective blocker of Na(+) channels), guanethidine (a nor-adrenergic neuron blocking drug), phentolamine (an alpha-adrenoceptor antagonist), Nomega-nitro-L-arginine (L-NNA, a nitric oxide (NO) synthase inhibitor) and endothelial denudation did not affect the BK-induced contraction. L-NNA and indomethacin induced contraction and relaxation under resting vascular tone respectively. These results suggest that endothelial cells are not involved in BK-induced contraction and that the contraction is not mediated via activation of known B(1) and B(2) receptors. Arachidonic acid metabolites and neurotransmitters like norepinephrine and NO might not play a role in BK-induced contraction in equine basilar artery.

Monolayer MoS2 field effect transistor with low Schottky barrier height with ferromagnetic metal contacts.

Two-dimensional MoS2 has emerged as promising material for nanoelectronics and spintronics due to its exotic properties. However, high contact resistance at metal semiconductor MoS2 interface still remains an open issue. Here, we report electronic properties of field effect transistor devices using monolayer MoS2 channels and permalloy (Py) as ferromagnetic (FM) metal contacts. Monolayer MoS2 channels were directly grown on SiO2/Si substrate via chemical vapor deposition technique. The increase in current with back gate voltage (Vg) shows the tunability of FET characteristics. The Schottky barrier height (SBH) estimated for Py/MoS2 contacts is found to be +28.8 meV (at Vg = 0V), which is the smallest value reported so-far for any direct metal (magnetic or non-magnetic)/monolayer MoS2 contact. With the application of positive gate voltage, SBH shows a reduction, which reveals ohmic behavior of Py/MoS2 contacts. Low SBH with controlled ohmic nature of FM contacts is a primary requirement for MoS2 based spintronics and therefore using directly grown MoS2 channels in the present study can pave a path towards high performance devices for large scale applications.

Model for the complex between protein G and an antibody Fc fragment in solution.

BACKGROUND: Streptococcal protein G and staphylococcal protein A are bacterial antibody-binding proteins, widely used as immunological tools, whose antibody-binding domains are structurally quite different. The binding of protein G to Fc fragments is competitive with respect to protein A, suggesting that the binding sites for protein A and protein G on Fc overlap, notwithstanding the fact that they lack sequence or structural similarity. RESULTS: To resolve this issue, the residues involved in the interaction between an IgG-binding domain of protein G (domain II) and the Fc fragment of mouse IgG2a have been identified by use of 13C and 15N NMR. Binding of protein G domain II selectively perturbed resonances from residues between the CH2 and CH3 domains of Fc, whereas in domain II the residues affected are primarily those on the alpha-helix and the third strand of the beta-sheet. This information was used, together with the structures of the two uncomplexed proteins, to construct a model of the complex, using Monte Carlo minimization techniques. In this model, the alpha-helix of protein G lies in the same position as helix 1 of protein A in the crystal structure of the protein A:Fc complex, but its orientation differs from the latter by 180 degrees. CONCLUSIONS: The interactions of the bacterial antibody-binding proteins with their 'target' immunoglobulins involve a very versatile set of protein-protein interactions. First, the IgG-binding domains of protein A and protein G have quite different three-dimensional structures, but bind to sites on the Fc fragment that overlap extensively. Secondly, protein G employs two quite different regions of its surface to bind to the Fab and Fc regions of IgG.

Multiple primary cancers in 5,456 autopsy cases in the National Cancer Center of Japan.

Multiple primary malignant neoplasms in 5,456 consecutive autopsy cases from 1962 to 1981 in the National Cancer Center were analyzed. There were 285 (5.2%) double primary cancers, 58 (1.1%) triple or more, and 65 (1.2%) minute cancers of the thyroid or prostate gland. Higher incidence of second cancer is observed in cancers of the oropharynx, intestine, larynx, uterus, bladder, and thyroid. Organ association between the two cancers was present in certain organs; for example, there was a tendency for upper gastrointestinal tract cancers to be associated with lower gastrointestinal tract cancers. Influence of histologic subtypes in multiple cancer cases is discussed for lung cancer.

Amplification of protooncogenes in surgical specimens of human lung carcinomas.

The possible existence of amplification or rearrangement of protooncogenes was examined in more than 100 surgical specimens of human lung carcinoma. Protooncogenes were amplified in 28% of the carcinomas. About 90% of the amplified genes were of the myc, ras, or erbB family. Of the myc family genes, myc was amplified in 14 of 137 tumors and L-myc in four of 108 tumors, but N-myc was not amplified. A high frequency of amplification of myc was observed in squamous cell carcinomas (seven of 37) and of L-myc in small cell carcinomas (two of six). Of the ras family genes, K-ras-2 was amplified in six of the 137 tumors and N-ras in two of the 137 tumors, but no amplification of H-ras-1 was detected. Seven of the eight cases of amplified ras genes were in advanced pathological stages. Of the erbB family genes, erbB-1 (epidermal growth factor receptor) was amplified in 10 of 114 tumors and erbB-2 (HER-2/neu) in one of 51 tumors. Amplifications of the myc, ras, and erbB family genes might be one of the crucial DNA abnormalities involved in the development of human lung carcinomas.

Aberrations of the p53 tumor suppressor gene in human non-small cell carcinomas of the lung.

Aberrations of the p53 gene in 115 surgical specimens of non-small cell carcinomas of the lung were examined by single-strand conformation polymorphism analysis of polymerase chain reaction products. Structural abnormalities of the p53 gene were observed in 60 tumors (52%), i.e., 8 of 14 large cell carcinomas, 24 of 58 adenocarcinomas, 25 of 37 squamous cell carcinomas, and 3 of 6 adenosquamous carcinomas. Direct sequencing of abnormal DNA fragments revealed 45 single-base substitutions, 9 deletions or insertion of a short nucleotide sequence, and 3 two-base substitutions in 57 tumors. In the other 3 tumors, loss of one of the p53 alleles was observed, with no mutation in the other allele. Allelic loss of the p53 gene was observed in 14 of 43 informative cases (33%), and in 11 of the 14 cases the remaining allele was mutated. The aberrations of the p53 gene were not limited to a particular histological type or clinical stage. Their high frequency suggests that they were involved in the genesis of non-small cell carcinomas of the lung. The mutation frequency (46%) of the p53 gene in tumors carrying mutated ras genes was essentially the same as the overall frequency in lung cancers, suggesting that accumulation of mutations in these two genes in a tumor is a random phenomenon.

Joining of the c-myc gene and a line 1 family member on chromosome 8 in a human primary giant cell carcinoma of the lung.

A rearranged c-myc gene found in a human primary giant cell carcinoma of the lung was analyzed. The rearrangement was found in the region about 6 kilobase pairs upstream of the c-myc gene. The breakpoint was joined to a sequence carrying a Line 1 (L1) family member located on chromosome 8. This in vivo rearrangement of the c-myc gene specific to tumor cells may represent one mechanism of activation of a protooncogene during tumorigenesis or tumor progression in human cancer.

myc family gene abnormality in lung cancers and its relation to xenotransplantability.

In order to study the relationship between tumor transplantability to the nude mouse and abnormality of the myc family genes (c-myc, N-myc, L-myc) in human primary lung cancers, 32 various lung cancers were analyzed for abnormality of the myc family genes by Southern blot hybridization, and were transplanted s.c. into nude mice. Southern blot analysis showed that four non-small cell carcinomas and three small cell carcinomas had amplified c-myc and L-myc genes, respectively. Allelic deletion of the L-myc gene was observed in seven cancers, of which two also had an additional band of the c-myc gene or amplification of the L-myc gene. No abnormality of the N-myc gene was observed in this series. Of 13 cancers with abnormality of the myc family genes, 11, including all tumors with myc gene amplification, were transplantable to nude mice. Of 19 tumors without any abnormalities of the myc family genes, however, only five were transplantable to nude mice (P less than 0.005). These results indicate that abnormality of the myc family genes, especially gene amplification, might promote tumorigenic ability in xenotransplantation of lung cancers and this phenomenon might be closely related to the function of the myc gene.

Mutations in an Alu repeated sequence associated with the DXS43 locus in human small cell lung cancers.

Point mutations in an Alu repeated sequence associated with the DXS43 locus were identified in two out of 10 human small cell lung cancers. Since these aberrations were identified in DNA from both metastatic lesions and primary lesions from the same patient, they would appear to have occurred at a relatively early stage. Although this sequence is not apparently associated with known genes, these tumor-specific mutations occurred at an early stage may play an important role in tumorigenesis.

Rearrangement and co-amplification of L-myc and rlf in primary lung cancer.

We have recently characterized a gene fusion and chimeric protein product formed by L-myc and part of a novel gene named rlf in two small-cell lung cancer (SCLC) cell lines. The rlf-L-myc fusion gene is formed by intrachromosomal rearrangements placing the regulatory region and (at least) the first exon of rlf upstream of the L-myc gene. In the characterized cases the fusion gene has also been involved in DNA amplification. Here we report on a similar in vivo rearrangement involving rlf and L-myc in a primary SCLC tumor. In addition, we have found co-amplification of L-myc and rlf without visible rearrangements in either gene in three other SCLC tumors, confirming the physical linkage of these loci.

DNA aberrations at the retinoblastoma gene locus in human squamous cell carcinomas of the lung.

We detected DNA aberrations at the RB locus in surgical specimens of human primary non-small cell lung carcinoma by single-strand conformation polymorphism analysis of polymerase chain reaction products amplified from regions of exons 2 to 27 including parts of the flanking intron sequences. Detection of nucleotide sequence polymorphism revealed loss of heterozygosity in six of eight informative cases among 13 squamous cell carcinomas analysed. In two of the six cases, mutations in the remaining allele were detected. In 25 adenocarcinomas analysed, no loss of heterozygosity was observed in 16 informative cases and a point mutation was detected in one of the uninformative cases. In one of three adenosquamous carcinomas analysed, a point mutation was detected and one adenoid cystic carcinoma analysed showed allelic loss of the RB gene. Our results indicated that loss of heterozygosity at the RB locus is frequent in squamous cell carcinomas of the lung, but not in adenocarcinomas. In the squamous cell carcinomas with allelic loss, mutations of the RB gene in the remaining alleles were found in one third of the tumors.