bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic EEG‐informed fMRI modeling of the pain matrix using 20‐ms root mean square segments
Authors: Brinkmeyer Juergen , Mobascher Arian , Warbrick Tracy , Musso Francesco , Wittsack Hans‐Jörg , Saleh Andreas , Schnitzler Alfons , Winterer Georg
Published: February 2010

Previous studies on the spatio‐temporal dynamics of cortical pain processing using electroencephalography (EEG), magnetoencephalography (MEG), or intracranial recordings point towards a high degree of parallelism, e.g. parallel instead of sequential activation of primary and secondary somatosensory areas or simultaneous activation of somatosensory areas and the mid‐cingulate cortex. However, because of the inverse problem, EEG and MEG provide only limited spatial resolution and certainty about the generators of cortical pain‐induced electromagnetic activity, especially when multiple sources are simultaneously active. On the other hand, intracranial recordings are invasive and do not provide whole‐brain coverage. In this study, we thought to investigate the spatio‐temporal dynamics of cortical pain processing in 10 healthy subjects using simultaneous EEG/functional magnetic resonance imaging (fMRI). Voltages of 20 ms segments of the EEG root mean square (a global, largely reference‐free measure of event‐related EEG activity) in a time window 0–400 ms poststimulus were used to model trial‐to‐trial fluctuations in the fMRI blood oxygen level dependent (BOLD) signal. EEG‐derived regressors explained additional variance in the BOLD signal from 140 ms poststimulus onward. According to this analysis, the contralateral parietal operculum was the first cortical area to become activated upon painful laser stimulation. The activation pattern in BOLD analyses informed by subsequent EEG‐time windows suggests largely parallel signal processing in the bilateral operculo‐insular and mid‐cingulate cortices. In that regard, our data are in line with previous reports. However, the approach presented here is noninvasive and bypasses the inverse problem using only temporal information from the EEG. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Strong expression of IGF1R in pediatric gastrointestinal stromal tumors without IGF1R genomic amplification
Authors: Janeway Katherine A. , Zhu Mei‐Jun , Barretina Jordi , Perez‐Atayde Antonio , Demetri George D. , Fletcher Jonathan A.
Published: February 2010

Wildtype (WT) gastrointestinal stromal tumors (GISTs), lacking mutations in KIT or PDGFRA, represent 85% of GISTs in pediatric patients. Treatment options for pediatric WT GIST are limited. Recently, expression profiling of a limited number of pediatric and adult WT GISTs and more in depth study of a single pediatric WT GIST implicated the insulin‐like growth factor 1 receptor (IGF1R) as a potential therapeutic target in pediatric WT GIST. We performed immunoblotting, SNP and FISH studies to determine the extent of expression, biochemical activation and genomic amplification of IGF1R in a larger number of pediatric WT GISTs. Pediatric WT GISTs expressed IGF1R strongly, whereas typical adult KIT mutant GISTs did not. IGF1R gene amplification was not detected in pediatric WT GISTs, and some KIT‐mutant GISTs had IGF1R gene deletion due to monosomy 15. Despite the absence of apparent genomic activation mechanisms accounting for overexpression, clinical study of IGF1R‐directed therapies in pediatric WT GIST is warranted.
Glioblastoma cells incorporate into tumor vasculature and contribute to vascular radioresistance
Authors: Shaifer Candice A. , Huang Jianhua , Lin Pengnain Charles
Published: February 2010

Glioblastoma multiforme (GBM) remains the most devastating neoplasm of the central nervous system and has a dismal prognosis. Ionizing radiation represents an effective therapy for GBM, but radiotherapy remains only palliative because of radioresistance. In this study, we demonstrate that glioma cells participate in tumor vascularization and contribute to vascular radioresistance. Using a 3‐dimensional coculture system, we observed an intimate interaction of glioma cells with endothelial cells whereby endothelial cells form vascular structures, followed by the recruitment and vascular patterning of glioma cells. In addition, tumor cells stabilize the vascular structures and render them radioresistant. Blocking initial endothelial vascular formation with endothelial‐specific inhibitors prevented tumor cells from forming any structures. However, these inhibitors exhibited minimum effects on vascular structures formed by tumor cells, due to the absence of the targeted receptors on tumor cells. Consistent with the in vitro findings, we show that glioma cells form perfused blood vessels in xenograft tumor models. Together, these data suggest that glioma cells mimic endothelial cells and incorporate into tumor vasculature, which may contribute to radioresistance observed in GBM. Therefore, interventions aimed at the glioma vasculature should take into consideration the chimeric nature of the tumor vasculature.
Deguelin—An inhibitor to tumor lymphangiogenesis and lymphatic metastasis by downregulation of vascular endothelial cell growth factor‐D in lung tumor model
Authors: Hu Jia , Ye Haoyu , Fu Afu , Chen Xiang , Wang Yongsheng , Chen Xiancheng , Ye Xia , Xiao Wenjing , Duan Xingmei , Wei Yuquan , Chen Lijuan
Published: February 2010

Deguelin, a rotenoid of the flavonoid family, has been reported to possess antiproliferative and anticarcinogenic activities in several cell lines and tumor models. However, it is still unclear whether deguelin effectively inhibits tumor‐associated lymphangiogenesis and lymphatic metastasis. Since tumor production of vascular endothelial cell growth factor (VEGF)‐D was associated with tumor lymphangiogenesis and lymphatic metastasis, we established the mouse lymphatic metastasis model by transfecting high expression VEGF‐D into LL/2 Lewis lung cells (VEGF‐D‐LL/2) and explored the effects of deguelin on lymphatic metastasis in the immunocompetent C57BL/6 mice. Our results indicated that deguelin inhibited proliferation, migration of VEGF‐D‐LL/2 cells via downregulating AKT and mitogen‐activated protein kinase pathway and interfered tube formation of lymphatic vascular endothelial cells on matrigel at nanomolar concentrations. Deguelin significantly downregulated the expression of VEGF‐D both at mRNA and protein levels in VEGF‐D‐LL/2 cells in a dose‐dependent manner. In the in vivo study, intraperitoneal administration of deguelin (4 mg/kg) remarkably inhibited the tumor‐associated lymphangiogenesis and lymphatic metastasis. The rates of lymph node and lung metastasis in deguelin‐treated mice were 0 and 16.7% compared with 58.3 and 83.3% in control group mice, respectively. Deguelin also resulted in a remarkable delay of tumor growth and prolongation of life span. Immunohistochemical staining with antibodies against VEGF‐D, LYVE‐1 and VEGFR‐3 revealed fewer positive vessel‐like structures in deguelin‐treated mice compared with control group mice. Taken together, we demonstrate for the first time that deguelin suppresses tumor‐associated lymphangiogenesis and lymphatic metastasis by downregulation of VEGF‐D both in vitro and in vivo.
Breast cancer survival in England, Norway and Sweden: a population‐based comparison
Authors: Møller Henrik , Sandin Fredrik , Bray Freddie , Klint Åsa , Linklater Karen M. , Purushotham Arnie , Robinson David , Holmberg Lars
Published: February 2010

Several international studies have found that survival from breast cancer is lower in the United Kingdom than in some other European countries. We have compared breast cancer survival between the national populations of England, Norway and Sweden, with a view to identifying subsets of patients with particularly good or adverse survival outcomes. We extracted cases of breast cancer in women diagnosed 1996–2004 from the national cancer registries of the 3 countries. The study comprised 303,657 English cases, 24,919 Norwegian cases and 57,512 cases from Sweden. Follow‐up was in 2001–2004. The main outcome measures were 5‐year cumulative relative survival and excess death rates, stratified by age and period of follow‐up. In comparison with Norway and Sweden, the excess mortality in England was particularly pronounced in the first month and in the first year after diagnosis, and generally more marked in the oldest age groups. Compared with Norwegian patients, 81% of the excess deaths in the English patients occurred in the first 2 years after diagnosis. Our findings emphasise the importance of awareness of symptoms and early detection as the main strategy to improve breast cancer survival in the United Kingdom.
Combined analysis of specific KRAS mutation, BRAF and microsatellite instability identifies prognostic subgroups of sporadic and hereditary colorectal cancer
Authors: Zlobec Inti , Kovac Michal , Erzberger Priska , Molinari Francesca , Bihl Michel P. , Rufle Alexander , Foerster Anja , Frattini Milo , Terracciano Luigi , Heinimann Karl , Lugli Alessandro
Published: February 2010

Confounding effects of specific KRAS gene alterations on colorectal cancer (CRC) prognosis stratified by microsatellite instability (MSI) and BRAFV600E have not yet been investigated. The aim of our study was to evaluate the combined effects of MSI, BRAFV600E and specific KRAS mutation (Gly → Asp; G12D, Gly → Asp, G13D; Gly → Val; G12V) on prognosis in 404 sporadic and 94 hereditary CRC patients. MSI status was determined according to the Bethesda guidelines. Mutational status of KRAS and BRAFV600E was assessed by direct DNA sequencing. In sporadic CRC, KRAS G12D mutations had a negative prognostic effect compared to G13D and wild‐type cancers (p = 0.038). With MSI, specific KRAS and BRAFV600E mutations, 3 distinct prognostic subgroups were observed in univariate (p = 0.006) and multivariable (p = 0.051) analysis: patients with (i) KRAS mutation G12D, G12V or BRAFV600E mutation, (ii) KRAS/BRAFV600E wild‐type or KRAS G13D mutations in MSS/MSI‐L and (iii) MSI‐H and KRAS G13D mutations. Moreover, none of the sporadic MSI‐H or hereditary patients with KRAS G13 mutations had a fatal outcome. Specific KRAS mutation is an informative prognostic factor in both sporadic and hereditary CRC and applied in an algorithm with BRAFV600E and MSI may identify sporadic CRC patients with poor clinical outcome.
Endometrial cancer incidence trends in Norway during 1953–2007 and predictions for 2008–2027
Authors: Lindemann Kristina , Eskild Anne , Vatten Lars J. , Bray Freddie
Published: February 2010

Endometrial cancer is the most common cancer of the female genital tract in Western countries. Monitoring the incidence is important for health care planning and the identification of risk factors. We present an age‐period‐cohort analysis of incidence trends of endometrial cancer in Norway from 1953 to 2007 and compare the incidence trends with those in 3 other Nordic countries. Based on the observed trends, we have predicted endometrial cancer rates in Norway in 2015 and 2025. In women at postmenopausal age (≥55 years), the annual incidence increase was 2.1% (95% CI: 0.9%, 3.4%) from 1988 to 1997 and 1.7% (95% CI: 0.6%, 2.8%) from 1998 to 2007. In younger women, there was an annual reduction of 0.6% (95% CI: −2.3%, 2.2%) from 1988 to 1997, followed by an annual increase of 1.7% (95% CI: −0.4%, 3.9%) from 1998 to 2007. The secular changes are likely to reflect both cohort and period effects. Our prediction estimates by 2025 suggest an incidence increase in the range of 50 to 100%, relative to the observed incidence in 2005. There has been a strong and consistent incidence increase in endometrial cancer in the Nordic countries over the last 50 years. The increase has been most pronounced in postmenopausal women, but in the last decade, rates have increased also in women younger than 55 years. The prediction for the next 20 years suggests that endometrial cancer rates will dramatically increase unless effective preventive strategies are implemented.
Activin A induction of erythroid differentiation through MKK6‐p38α/p38β pathway is inhibited by follistatin
Authors: Huang Huei‐Mei , Li Yung‐Chen , Chung Ming‐Hui
Published: February 2010

Activin A is a member of the transforming growth factor (TGF)‐β superfamily that regulates cell proliferation and differentiation. Using the p38 inhibitor SB203580, our previous studies demonstrated that p38 was involved in activin A‐mediated hemoglobin (Hb) synthesis in K562 cells. SB203580 is an inhibitor of p38α and p38β isoforms. In this study, we show that p38α and p38β mRNA were expressed in K562 cells and that activin A activated the kinase activities of these isoforms. To investigate the roles of p38α and p38β isoforms in activin A‐mediated erythroid differentiation, we generated stable clones that over‐expressed the dominant negative p38 isoforms p38α(AF) and p38β(AF) in K562 cells. The expressions of either p38α(AF) or p38β(AF) reduced activin A‐induced p38 activation, Hb synthesis, and ζ‐globin promoter activity. Similarly, down‐regulation of either p38α or p38β by isoform‐specific siRNAs also reduced activin A‐induced ζ‐globin promoter activity. Co‐expressions of p38α(AF) and p38β(AF), together, greatly inhibited the transcription activity of the ζ‐globin promoter. Conversely, expression of mitogen‐activated protein kinase kinase (MKK) 6b(E), a constitutive activator of p38, significantly activated ζ‐globin promoter. Co‐expressions of either p38α or p38β with MKK6b had a similar activation of ζ‐globin promoter. Activin A induction of erythroid differentiation was inhibited by follistatin. Activin A‐induced phosphorylation of MKK6 and p38 was also inhibited by follistatin. Moreover, over‐expression of MKK6b(E) reverted follistatin inhibition of activin A‐induced ζ‐globin promoter activity. These results demonstrate that activin A induces erythroid differentiation of K562 cells through activation of MKK6‐p38α/p38β pathway and follistatin inhibits those effects. J. Cell. Physiol. 223:687–694, 2010. © 2010 Wiley‐Liss, Inc.
Cefazolin embedded biodegradable polypeptide nanofilms promising for infection prevention: A preliminary study on cell responses
Authors: Li Hongshuai , Ogle Heather , Jiang Bingbing , Hagar Michael , Li Bingyun
Published: February 2010

Implant‐associated infection is a serious complication in orthopedic surgery, and endowing implant surfaces with antibacterial properties could be one of the most promising approaches for preventing such infection. In this study, we developed cefazolin loaded biodegradable polypeptide multilayer nanofilms on orthopedic implants. We found that the amount of cefazolin released could be tuned. A high local concentration of cefazolin was achieved within the first a few hours and therefore may inhibit bacterial colonization in the critical postimplantation period. The developed cefazolin loaded nanofilms showed their in vitro efficacy against Staphylococcus aureus; the more antibiotics loaded, the longer the nanocoated implant had antibacterial properties. More interestingly, antibiotic‐loaded polypeptide multilayer nanofilms also improved osteoblast bioactivity including cell viability and proliferation. These findings suggested that biodegradable polypeptide multilayer nanofilms as antibiotic carriers at the implant/tissue interface are compatible with human cells such as osteoblasts and bactericidal to bacteria such as S. aureus. These characteristics could be promising for preventing implant‐associated infection and potentially improving bone healing. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:992–999, 2010
Characterization of novel astragaloside malonates from Radix Astragali by HPLC with ESI quadrupole TOF MS
Authors: Chu Chu , Cai Hai‐Xia , Ren Mei‐Ting , Liu E‐Hu , Li Bin , Qi Lian‐Wen , Li Ping
Published: February 2010

A structurally identified new compound named malonylastragaloside I was isolated and obtained from Radix Astragali. This novel compound was found to be unstable especially under high temperature and pH value. Using sonication extraction, addition of formic acid, and an efficient medium pressure ODS C18 column chromatography method, a high yield of 40 mg of this compound was obtained from 150 g of powdered crude herbal medicine. Malonylastragaloside I was structurally characterized by NMR and ESI quadrupole TOF MS. With the strategy of target precursor ions scan, a total of 22 astragalosides including 8 astragaloside malonates were screened and characterized from the methanolic extract of Radix Astragali by HPLC‐Q‐TOF/MS. The eight astragaloside malonates were found in both Astragalus membranaceus var. mongholicus and A. membranaceus. The results provided a real profile of various triterpene saponins in Radix Astragali. It is a first report regarding isolation and characterization of astragaloside malonates in Astragalus species.
An ab initio chemical kinetic study on the reactions of H, OH, and Cl with HOClO3
Authors: Zhu R. S. , Lin M. C.
Published: February 2010

The mechanisms for reactions of H, HO, and Cl with HOClO3, important elementary processes in the early stages of the ammonium perchlorate (AP) combustion reaction, have been investigated at the CCSD(T)/6‐311+G(3df,2p)//PW91PW91/6‐311+G(3df) level of theory. The rate constants for the low‐energy channels have been calculated by statistical theory. For the reaction of H and HOClO3, the main channels are the production of H2 + ClO4 (k1a) and HO + HOClO2 (k1b); k1a and k1b can be represented as 1.07 × 10−17 T1.97 exp(−7484/T) and 6.08 × 10−17T1.96 exp(−7729/T) cm3 molecule−1 s−1, respectively. For the HO + HOClO3 reaction, the main pathway is the H2O + ClO4 (k2a) production process, with the predicted rate constant k2a = 1.24 × 10 −8 T−2.99 exp(1664/T) for 300–500 K and k2a = 1.27×10−19 T2.12 exp(−1474/T) for 500–3000 K. For the Cl + HOClO3 reaction, the formation of HOCl + ClO3 (k3a) and HCl + ClO4 (k3b) is dominant, with k3a = 1.33×10−12 T0.67 exp(−9658/T) and k3b = 1.75×1016 T1.63 exp(−11156/T) cm3 molecules−1 in the range of 300–3000 K. In addition, the heats of formation of ClO3 and HOClO3 have been predicted based on several isodesmic and/or isogyric reactions with ΔfHo0 (ClO3) = 47.0 ± 1.0 and ΔfHo0 (HOClO3) = 5.5 ± 1.5 kcal/mol, respectively. These data may be used for kinetic simulation of the AP decomposition and combustion reaction. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 253–261, 2010
Preparation and properties of thermosensitive organic‐inorganic hybrid gels containing modified nanosilica
Authors: Huang Wei‐Jen , Tsai Han‐Hsueh , Lee Wen‐Fu
Published: February 2010

A series of thermosensitive organic–inorganic hybrid gels containing nanosilica or modified nanosilica were prepared from N‐isopropylacrylamide (NIPAAm), and N,N′‐methylene‐bis‐acrylamide (NMBA) and nanosilica (AE200) or modified AE200 (mAE200); and NIPAAm, NMBA, 3‐(trimethoxysilyl) propyl methacrylate (TMSPMA) as coupling agent and AE200 or mAE200 in this study. The effect of inorganic nanosilica on the swelling behaviors and mechanical properties were investigated by adding different amount of nanosilica and modified nanosilica. Results showed that the swelling ratios of the hybrid gels decrease with increasing nanosilica content. Existence of silane coupling agent would also reduce the swelling ratios of the hybrid gels. Adding coupling agent or nanosilica would improve the gel strength. Modification of nanosilica by grafting amino‐silane via sol–gel process was carried out and the effect of addition of modified silica on gel properties was also investigated. Results showed that the hybrid gels containing modified silica would have higher swelling ratios and moduli than those containing unmodified silica. Gels containing both silane coupling agent and silica would have higher crosslinking density because the silica would be better crosslinked with coupling agent. POLYM. COMPOS., 31:1712–1721, 2010. © 2010 Society of Plastics Engineers.
Rheological behavior and mechanical properties of PVC/MAP‐POSS nanocomposites
Authors: Gao Jungang , Du Yonggang , Dong Cuifang
Published: February 2010

The polyhedral oligomeric silsesquioxanes which contains methylacryloylpropyl groups (MAP‐POSS) was synthesized. The MAP‐POSS/PVC nanocomposites were prepared. The influences of composition, shear rate' shear stress on melting rheological behavior of MAP‐POSS/PVC nanocomposites were discussed. The dynamic mechanical properties, mechanical properties, and morphology were determined by DMA, material tester and SEM, respectively. The result shows that the plastic times decreases and melt viscosity increases with increasing MAP‐POSS content. The n has a maximal value at 5 wt% MAP‐POSS content, but have best impact strength at 3%. MAP‐POSS can use as process aid and impact aid of PVC at appropriate contents. POLYM. COMPOS., 31:1822–1827, 2010. © 2010 Society of Plastics Engineers.
Identification of kaempferol‐regulated proteins in rat calvarial osteoblasts during mineralization by proteomics
Authors: Kumar Avinash , Singh Anand K. , Gautam Abnish K. , Chandra Deepak , Singh Divya , Changkija Bendangla , Singh Mahendra Pratap , Trivedi Ritu
Published: February 2010

Kaempferol, a flavonoid, promotes osteoblast mineralization in vitro and bone formation in vivo; however, its mechanism of action is yet unknown. We adopted proteomic approach to identify the differential effect of kaempferol on rat primary calvarial osteoblasts during mineralization. The primary rat calvarial osteoblasts were treated with kaempferol (5.0 μM) for 9 days under mineralizing condition that resulted in significant increase in alkaline phosphatase activity and mineralization of the cells. Further, 2‐D analysis of the kaempferol‐treated osteoblast lysates revealed 18 differentially expressed proteins (nine upregulated and nine downregulated) on the basis of >/<2.0‐fold as cut‐off (p<0.01) that were then identified by MALDI‐TOF MS. These included cytoskeletal proteins, intracellular signaling protein, chaperone, extracellular matrix protein, and proteins involved in glycolysis and cell–matrix interactions. Proteomics data were confirmed by Western blotting and quantitative real‐time PCR by randomly selecting two upregulated and two downregulated proteins. Western blot analysis confirmed upregulation of HSP‐70 and cytokeratin‐14 levels, and downregulation of aldose reductase and caldesmon expression. We further demonstrated that kaempferol treatment inhibits aldose reductase activity in osteoblasts indicating an altered cellular metabolism by decelerating polyol pathway that was associated with the kaempferol‐induced osteoblast mineralization. In conclusion, this is a first comprehensive study on the differential regulation of proteins by kaempferol in primary osteoblast, which would further help to elucidate the role of the identified proteins in the process of osteoblast mineralization.
Use of newer antiepileptic drugs in children: how NICE are we?
Authors: Lyons Beatrice , Abdelmagid Elhassan , Banerjee Somnath
Published: February 2010

The 2004 NICE technology appraisal defined new standards for the use of newer antiepileptic drugs (AEDs) in children.The aim of this audit was to identify the level of compliance with the NICE guidelines in an epilepsy clinic at a district general hospital in East Kent.The reason why a child was started on a particular AED, the efficacy of the drug of choice and whether the child had appropriate specialist reviews were investigated. Copyright © 2010 Wiley Interface Ltd
Computational model of hepatitis B virus DNA polymerase: Molecular dynamics and docking to understand resistant mutations
Authors: Daga Pankaj R. , Duan Jinsong , Doerksen Robert J.
Published: February 2010

Hepatitis B virus (HBV) DNA polymerase (HDP) is a pharmacological target of intense interest. Of the seven agents approved in USA for the treatment of HBV infections, five are HDP inhibitors. However, resistance development against HDP inhibitors, such as lamivudine and adefovir, has severely hurt their efficacy to treat HBV. As a step toward understanding the mechanism of resistance development and for gaining detailed insights about the active site of the enzyme, we have built a homology model of HDP which is an advance over previously reported ones. Validation using various techniques, including PROSTAT, PROCHECK, and Verify‐3D profile, proved the model to be stereochemically significant. The stability of the model was studied using a 5 ns molecular dynamics simulation. The model was found to be sufficiently stable after the initial 2.5 ns with overall root mean squared deviation (RMSD) of 4.13 Å. The homology model matched the results of experimental mutation studies of HDP reported in the literature, including those of antiviral‐resistant mutations. Our model suggests the significant role of conserved residues, such as rtLys32, in binding of the inhibitors, contrary to previous studies. The model provides an explanation for the inactivity of some anti‐HIV molecules which are inactive against HDP. Conformational changes which occurred in certain binding pocket amino acids helped to explain the better binding of some of the inhibitors in comparison to the substrates.
Atomic resolution crystallography of a complex of triosephosphate isomerase with a reaction‐intermediate analog: New insight in the proton transfer reaction mechanism
Authors: Alahuhta Markus , Wierenga Rik K.
Published: February 2010

Enzymes achieve their catalytic proficiency by precisely positioning the substrate and catalytic residues with respect to each other. Atomic resolution crystallography is an excellent tool to study the important details of these geometric active‐site features. Here, we have investigated the reaction mechanism of triosephosphate isomerase (TIM) using atomic resolution crystallographic studies at 0.82‐Å resolution of leishmanial TIM complexed with the well‐studied reaction‐intermediate analog phosphoglycolohydroxamate (PGH). Remaining unresolved aspects of the reaction mechanism of TIM such as the protonation state of the first reaction intermediate and the properties of the hydrogen‐bonding interactions in the active site are being addressed. The hydroxamate moiety of PGH interacts via unusually short hydrogen bonds of its N1O1 moiety with the carboxylate group of the catalytic glutamate (Glu167), for example, the distance of N1(PGH)‐OE2(Glu167) is 2.69 ± 0.01 Å and the distance of O1(PGH)‐OE1(Glu167) is 2.60 ± 0.01 Å. Structural comparisons show that the side chain of the catalytic base (Glu167) can move during the reaction cycle in a small cavity, located above the hydroxamate plane. The structure analysis suggests that the hydroxamate moiety of PGH is negatively charged. Therefore, the bound PGH mimics the negatively charged enediolate intermediate, which is formed immediately after the initial proton abstraction from DHAP by the catalytic glutamate. The new findings are discussed in the context of the current knowledge of the TIM reaction mechanism. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Observation of the J‐sheet of the Fermi surface of YbRh2Si2
Authors: Sutton A. B. , Rourke P. M. C. , Taufour V. , McCollam A. , Lapertot G. , Knebel G. , Flouquet J. , Julian S. R.
Published: February 2010

We report a previously unobserved quantum oscillation frequency in YbRh2Si2. This is the first quantum oscillation that can definitely be assigned to the second of the two major sheets of the Fermi surface predicted by band structure calculations. These calculations have been done for two scenarios: the “large” Fermi surface, which includes the Yb 4f‐hole in the Fermi volume, and the “small” Fermi surface, which does not. Previously observed frequencies were interpreted in terms of a “large” Fermi surface that has been so strongly spin‐split that it closely resembles the “small” Fermi surface. The new frequency can also be incorporated into this picture, however there are some indications that the situation is more complicated than was assumed, suggesting a need for more advanced band structure calculations.
Phase diagrams and switching of voltage and magnetic field in dilute magnetic semiconductor nanostructures
Authors: Escobedo R. , Carretero M. , Bonilla L. L. , Platero G.
Published: February 2010

The response of an n‐doped dc voltage biased II–VI multi‐quantum well dilute magnetic semiconductor nanostructure having its first well doped with magnetic (Mn) impurities is analyzed by sweeping wide ranges of both the voltage and the Zeeman level splitting induced by an external magnetic field. The level splitting versus voltage phase diagram shows regions of stable self‐sustained current oscillations immersed in a region of stable stationary states. Transitions between stationary states and self‐sustained current oscillations are systematically analyzed by both voltage and level splitting abrupt switching. Sudden voltage or/and magnetic field changes may switch on current oscillations from an initial stationary state, and reciprocally, current oscillations may disappear after sudden changes of voltage or/and magnetic field changes into the stable stationary states region. The results show how to design such a device to operate as a spin injector and a spin oscillator by tuning the Zeeman splitting (through the applied external magnetic field), the applied voltage and the sample configuration parameters (doping density, barrier and well widths, etc.) to select the desired stationary or oscillatory behavior.

magnified image

Phase diagram of Zeeman level splitting Δ vs. dimensionless applied voltage ϕ for N = 10 QWs. White region: stable stationary states; black: stable self‐sustained current oscillations.

(© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spontaneous‐adjustment emission of inertia‐gravity waves by unsteady vortical motion in the hurricane core
Authors: Hendricks E. A. , Schubert W. H. , Fulton S. R. , McNoldy B. D.
Published: February 2010

Spontaneous‐adjustment emission of inertia‐gravity waves (IGWs) from unsteady vortical motion in the hurricane core is further examined. An idealized divergent barotropic model simulation is conducted in an unforced framework using a highly asymmetric potential vorticity (PV) field, consisting of an offset monopole embedded in an elliptically shaped ring, which is motivated by concentric eyewalls that were observed in the inner core of hurricane Ivan (2004). The simulation proceeds in two phases. The first phase is marked primarily by inner‐core potential vorticity (PV) mixing and rearrangement as the monopole interacts with the ring, however axisymmetrization does not occur. This leads to a second phase characterized by a prolonged (lasting at least 36 h) period of spontaneous‐adjustment emission of IGWs to the environment. During the spontaneous‐adjustment phase, unsteady vortical motion acts as an IGW source, constraining the frequency and radial wavenumber of the waves. Diagnostics of this simulation reveal two important conclusions. First, the spontaneous radiation of IGWs is insignificant for vortex intensification or decay; rather, PV mixing in the early portion was more important. Secondly, using a non‐divergent barotropic model simulation of the same configuration and idealized simulations, we demonstrate that non‐axisymmetrization in this case‐study is caused primarily by PV (Rossby wave) dynamics, with the Rossby‐IGW instability only playing a minor role. These results support the existence of a slow quasi‐manifold with exponentially small fuzziness at small Froude and large Rossby numbers. Copyright © 2010 Royal Meteorological Society
A density functional theory study on diazotization and nitration of 3,5‐diamino‐1,2,4‐triazole
Authors: Lian Peng , Lai Wei‐Peng , Wang Bo‐Zhou , Ge Zhong‐Xue , Xue Yong‐Qiang
Published: February 2010

The reaction mechanism, thermodynamic and kinetic properties for diazotization and nitration of 3,5‐diamino‐1,2,4‐triazole were studied by a density functional theory. The geometries of the reactants, transition states, and intermediates were optimized at the B3LYP/6‐31G (d, p) level. Vibrational analysis was carried out to confirm the transition state structures, and the intrinsic reaction coordinate (IRC) method was used to explore the minimum energy path. The single‐point energies of all stagnation points were further calculated at the B3LYP (MP2)/6‐311+G (2d, p) level. The statistical thermodynamic method and Eyring transition state theory with Wigner correction were used to study the thermodynamic and kinetic characters of all reactions within 0–25°C. Two reaction channels are computed, including the diazotization and nitration of 3‐NH2or 5‐NH2, and there are six steps in each channel. The reaction rate in each step is increased with temperature. The last step in each channel is the slowest step. The first, second, and fifth steps are exothermic reactions, and are favored at lower temperature in the thermodynamics. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Miniaturization of a Laser Doppler Blood Flow Sensor by System‐in‐Package Technology: Fusion of an Optical Microelectromechanical Systems Chip and Integrated Circuits
Authors: Iwasaki Wataru , Nogami Hirofumi , Higurashi Eiji , Sawada Renshi
Published: February 2010

We have developed the first and the smallest blood flow sensor composed of integrated circuits (ICs) fused with an optical microelectromechanical systems (MEMS) chip using system‐in‐package (SiP) technologies for application in a healthcare monitoring system. The probe of this blood flow sensor consists of three layers, and the optical MEMS chip is stacked as the top layer. Through silicon via (TSV), vertical‐cavity surface‐emitting laser (VCSEL) and cavities enable wafer‐level packaging of the optical MEMS chip. The other two layers consisting of ICs are highly densified by SiP technology, and the volume of the probe is miniaturized to about one‐sixth of our previously reported integrated laser Doppler blood flowmeter, an MEMS blood flow sensor to which SiP technology was not applied. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Shape‐prediction of 3D PTFE Microstructures Fabricated by Synchrotron Radiation Ablation
Authors: Horade Mitsuhiro , Sugiyama Susumu
Published: February 2010

This article describes the calculation of the predictions of the deformed shapes of three‐dimensional polytetrafluoroethylene (PTFE) microstructures fabricated by direct etching with a synchrotron radiation (SR) light source. As PTFE is a remarkable material, there is a lot of expectation regarding its applications in various devices. We did research on establishing a highly accurate three‐dimensional technology for microfabricating PTFE by using an SR‐light source because we aimed at applying this material in future devices. We built a shape‐prediction technique as part of this research. Since this technique had the advantage of predicting shapes without experimentation, both fabrication time and cost could be reduced. It is also a useful technique for investigating and clarifying processing mechanisms. We compared structures fabricated in an experiment and the shapes computed with shape‐prediction. The shape‐prediction results were mostly in agreement with those from the experiment. As PTFE demonstrated excellent material characteristics, especially in its resistance to chemicals, it should be possible to use it in the fabrication of micro total analysis systems (µ‐TAS) for biomedical applications. We expect that these applications will benefit from (based on) the designs which are predicted utilizing this calculation method. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
First‐Principles Simulation on Piezoresistive Properties in Doped Silicon Nanosheets
Authors: Nakamura Koichi , Toriyama Toshiyuki , Sugiyama Susumu
Published: February 2010

We have simulated the electronic states and piezoresistance coefficients in single‐crystal silicon (Si) nanosheets on the basis of first‐principles calculations of model structures. The carrier conductivities of the hydrogen‐terminated Si nanosheet models with (001) surface orientation have been calculated using band carrier densities and their corresponding effective mass tensors derived from the two‐dimensional (2D) band diagram by our original approach for a small amount of carrier occupation. The [110] uniaxial tensile stress causes band deformation, leading to the redistribution of carriers, and a drastic change of conductivity can be observed for nanosheet models. The p‐type longitudinal and transverse piezoresistance coefficients about the [110] tensile stress swell up as the nanosheet becomes thinner, and we have obtained high piezoresistance coefficients of 343 × 10−11 Pa−1 of πl[110] and − 141 × 10−11 Pa−1 of πt [110] for about 1 nm thickness. It is expected that p‐type ultra‐thin Si(001) nanosheet will be a suitable candidate for nanoscale piezoresistors due to its giant piezoresistivity. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Growth of GaN LED Structure on Si Substrate by MBE and Monolithic Fabrication of GaN LED Cooling System
Authors: Wakui Masashi , Hu Fang‐Ren , Sameshima Hidehisa , Hane Kazuhiro
Published: February 2010

GaN‐based light emitting diodes (LEDs) were fabricated by molecular beam epitaxy (MBE) on a GaN/Si substrate prepared by metal organic chemical vapor deposition (MOCVD). Blue light emission was obtained at the peak wavelength of 410 nm. An integration of GaN LEDs and a cooling system is proposed. GaN membrane structure with Si microchannels was fabricated from the GaN/Si substrate. A preliminary experiment for the proposed device was carried out. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Influence of Slope Angle and Traction Load on Performance of AZARASHI (Seal) Mechanism with One Degree of Freedom
Authors: Furutani Katsushi , Kawagoe Katsumi
Published: February 2010

This paper deals with the influence of a friction force on a small mobile device, AZARASHI (Seal) mechanism with a 1‐degree of freedom (DOF) in the cases of moving on a slope and drawing a load. This device has a piezoelectric actuator, electromagnet CA that applies a constant friction force and electromagnet CB alternating the friction force by on‐off control. AZARASHI mechanism has the same structure as the inchworm‐like mover. However, AZARASHI mechanism has a smaller number of actuators to be controlled and is driven by a smaller number of steps than the inchworm‐like mover. The motion performance on the slope from 0 to 90 degrees was experimentally investigated using a 1‐DOF device. In addition, the relationship between the displacement on a vertical plane and the friction forces was tested. Under a set of sufficient friction forces, this device was possible to climb even on the vertical plane. The traction load capacity of the 1‐DOF device was also investigated. As a result, the friction forces restricted the traction load capacity. Finally, its traction load capacity was compared with the inchworm‐like mover. The lowest friction force to hold each device restricted their displacement. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Learning Relation Instances for Chinese Domain Ontology from the Web
Authors: Tian Fang , Ren Fuji
Published: February 2010

This paper presents a method to extract relation instances from the Internet in order to acquire knowledge that has some relations for domain ontology. We propose an ontology relation instance learning model: data sources are collected though the Web search engine and the extracted instances are constructed in Web ontology language (OWL) by Protege in Chinese. Basically, the extraction of relation instances contains syntactic patterns for filtering concepts and relevance measurement for selection of relation instances. A relevance measurement based on co‐occurrence statistics is presented in this paper, which measures the semantic similarity of the measure between candidate instances and predefined domain keywords using Web search engines. In the experiment, we extract festival customs for different festival instances using relation ‘has_custom’ between festival class and custom class in the Chinese festival ontology, and prove the effectiveness of our method. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Optimal Design of Two‐stage Logistics Network Considered Inventory by Boltzmann Random Key‐based GA
Authors: Ataka Shinichiro , Kim Byungki , Gen Mitsuo
Published: February 2010

Logistics network design is one of the most important phases in supply chain management (SCM). Transportation planning (TP) is a well‐known basic network model that can be generally defined as a problem to minimize the total delivery cost. But for some real‐world applications, the TP model is often extended to satisfy other additional constraints or is performed in several stages. In addition, the concept of inventory is not included in a traditional TP model. Moreover, time concepts, such as carrying costs in a certain period, are not treated. Even if it is a plant that belongs to the same company, delivery methods may be different for each product. These restrictions on this model profoundly affect the use of the TP model in the real world. In this paper, we formulate a two‐stage transportation problem with inventory and exclusionary side constraints. In this model, 1 year is divided into several terms and the annual demands of delivery centers are satisfied for each term. This model includes the additional constraint in which simultaneous shipments between some plants are prohibited. To solve the problem, we propose an effective genetic algorithm (GA) method called the Boltzmann random key‐based GA (Brk‐GA). One characteristic of this method is that it features new selection processing through Boltzmann scaling and the local search techniques. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Proper Splitting of Interconnected Power Systems
Authors: Najafi S. , Hosseinian S. H. , Abedi M.
Published: February 2010

Power system islanding is the last defense line to protect power grids from incidence of wide‐area blackout. As a wide‐area control action, power system splitting is a comprehensive decision making problem that includes different subproblems. This paper introduces a novel approach for separation of the entire power system into several stable islands in different loading levels. The proposed method combines both the dynamic and the static characteristics of interconnected power network and determines the proper splitting schemes. The presented algorithm searches for proper islanding strategy in the boundary of primary determined coherent machines using Krylov subspace method and finds the proper splitting points by transferring some of the buses in one island to another island such that total load shedding is minimized. A spanning tree‐based depth first search algorithm is used to find all possible combination of transferred buses. The presented method reduces the huge initial search space of islanding strategy considering dynamic characteristics of integrated power system and reduction of search space to only boundary network. The speed of the proposed algorithm is remarkably high and can be applied for islanding the power system in real‐time. The presented algorithm is applied to IEEE 118 BUS test system. Results show the robustness, effectiveness, and capability of the algorithm to determine fast and accurate proper islanding strategy. Time domain simulation of the islanding strategies confirms that all the islands which are specified by the proposed method are stable. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Experimental Evaluation of Strictly Proper Approximation of State Predictor for Inverted Pendulum
Authors: Abe Naoto , Ohnuki Yusuke
Published: February 2010

This paper presents the experimental results for an inverted pendulum with time delay. A stabilized control law is constructed with the optimal regulator and distributed delay control. Numerical approximation of the distributed delay part gives rise to an unstable closed‐loop response. The problem was solved by using the strictly proper approximation reported by Mirkin in 2004. It is shown that the inverted pendulum with time delay is stabilized by the distributed delay control laws with the strictly proper approximation experimentally. The effectiveness and practical use of the method are discussed. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Particle Swarm Optimization with Parameter Self‐Adjusting Mechanism
Authors: Yasuda Keiichiro , Yazawa Kazuyuki , Motoki Makoto
Published: February 2010

This paper presents a self‐adjusting strategy for tuning the parameters of particle swarm optimization (PSO) based on some numerical analysis of the behavior of PSO. The proposed adaptive tuning strategy is based on self‐tuning of the parameters of PSO, a strategy that utilizes the information about the frequency of an updated group best of a swarm. The feasibility and advantages of the proposed self‐adjusting PSO (SAPSO) algorithm are demonstrated through some numerical simulations using four benchmark problems. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Multiple bHLH proteins regulate CIT2 expression in Saccharomyces cerevisiae
Authors: Chen Linan , Lopes John M.
Published: February 2010

The basic helix–loop–helix (bHLH) proteins comprise a eukaryotic transcription factor family involved in multiple biological processes. They have the ability to form multiple dimer combinations and most of them also bind a 6 bp site (E‐box) with limited specificity. These properties make them ideal for combinatorial regulation of gene expression. The Saccharomyces cerevisiae CIT2 gene, which encodes citrate synthase, was previously known to be induced by the bHLH proteins Rtg1p and Rtg3p in response to mitochondrial damage. Rtg1p–Rtg3p dimers bind two R‐boxes (modified E‐boxes) in the CIT2 promoter. The current study tested the ability of all nine S. cerevisiae bHLH proteins to regulate the CIT2 gene. The results showed that expression of CIT2–lacZ reporter was induced in a ρ0 strain by the presence of inositol via the Ino2p and Ino4p bHLH proteins, which are known regulators of phospholipid synthesis. Promoter mutations revealed that inositol induction required a distal E‐box in the CIT2 promoter. Interestingly, deleting the INO2, INO4 genes or the cognate E‐box revealed phosphate induction of CIT2 expression. This layer of expression required the two R‐boxes and the Pho4p bHLH protein, which is known to be required for phosphate‐specific regulation. Lastly, the data show that the Hms1p and Sgc1p bHLH proteins also play important roles in repression of CIT2–lacZ expression. Collectively, these results support the model that yeast bHLH proteins coordinate different biological pathways. Copyright © 2010 John Wiley & Sons, Ltd.