bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemistry of Hemin Self‐Assembled from Aqueous Hexadecyltrimethylammonium Bromide (CTAB) Solution on Single‐Wall‐Carbon‐Nanotube‐Modified Glassy Carbon Electrodes
Authors: Liu Jiwei , Qiu Jingxia , Sun Kai , Chen Jin , Miao Yuqing 
Published: March 2009

Abstractmagnified imageHemin could be dissolved directly in H2O solution in the presence of the cationic surfactant hexadecyltrimethylammonium bromide (CTAB). The hemin is adsorbed on the surface of single‐wall‐carbon‐nanotube‐modified glassy carbon (GC) electrodes by self‐assembly. The modified electrodes exhibit a well‐defined, reversible redox peak with the reduction potential at −0.30 V and a potential separation of 61 mV at pH 7.0. The peak current is found to increase linearly with the scan rate in the range 25–200 mV, and the peak potential is pH‐dependent. The modified electrodes exhibit obvious signal enhancement for the electrochemical reduction of O2 and H2O2, and oxidation of L‐cysteine, which is useful to develop their application in electroanalysis and biosensors.
Ouvrardianines A and B, Two New Norditerpenoid Alkaloids from Aconitum ouvrardianum
Authors: Jing Hong , Yang Xiao‐Dong , Zhao Jing‐Feng , Yang Shu , Zhang Hong‐Bin , Li Liang 
Published: March 2009

Abstractmagnified imageTwo new norditerpenoid alkaloids, ouvrardianines A and B (1 and 2, resp.), together with eight known compounds, were isolated from Aconitum ouvrardianum. The structures of the new compounds were elucidated as (1α,6α,14α,16β)‐8‐(acetyloxy)‐13‐hydroxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)aconit‐19‐en‐14‐yl benzoate (1) and (1α,6α,14α,16β)‐8‐(acetyloxy)‐20‐formyl‐13‐hydroxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)aconitan‐14‐yl benzoate (2) on the basis of spectral analyses. The new compound 1 was found to contain the rare C(19)N imine group.
A New Lycopodium Alkaloid, Lycoposerramine‐R, with a Novel Skeleton and Three New Fawcettimine‐Related Alkaloids from Lycopodium serratum
Authors: Katakawa Kazuaki , Kogure Noriyuki , Kitajima Mariko , Takayama Hiromitsu 
Published: March 2009

Abstractmagnified imageA new Lycopodium alkaloid, lycoposerramine‐R, possessing an unusual tetracyclic ring system, was isolated from Lycopodium serratum. Its structure as well as those of three new co‐existing fawcettimine‐related alkaloids were elucidated by means of extensive spectroscopic analysis.
New Galloylated Flavonoid Glycosides from Geranium stepporumDavis
Authors: Şöhretoğlu Didem , Sakar Mahmut Koray , Sterner Olov 
Published: March 2009

Abstractmagnified imageTwo new galloylated flavonoid glycosides, quercetin‐3‐O‐(3″‐O‐galloyl)‐β‐glucopyranoside (1) and quercetin‐3‐O‐(3″‐O‐galloyl)‐β‐galactopyranoside (2) were isolated from the aerial parts of Geranium stepporum along with the four known flavonoids, quercetin 3‐O‐β‐glucopyranoside (3), quercetin 3‐O‐β‐galactopyranoside (4), quercetin 3‐O‐(6″‐O‐galloyl)‐β‐glucopyranoside (5) and quercetin 3‐O‐(6″‐O‐galloyl)‐β‐galactopyranoside (6). The structure elucidation of the isolated compounds was accomplished by spectroscopic methods (UV, 1D‐ and 2D‐NMR, and ESI‐TOF‐MS).
DNA‐Binding Study of Nickel(II) and Zinc(II) Complexes with Two Novel Chromenone‐Based Schiff‐Base Ligands
Authors: Qin Dong‐Dong , Yang Zheng‐Yin , Li Tian‐Rong , Qi Gao‐Fei 
Published: March 2009

Abstractmagnified imageTwo new chromenone‐based Schiff‐base ligands, 3‐{[(1,5‐dihydro‐3‐methyl‐5‐thioxo‐4H‐1,2,4‐triazol‐4‐yl)imino]methyl}‐6‐hydroxy‐4H‐1‐benzopyran‐4‐one (L1) and 2,2′‐bis[(6‐hydroxy‐4‐oxo‐4H‐1‐benzopyran‐3‐yl)methylene]carbonothioic dihydrazide (L2), and their NiII and ZnII complexes were prepared. All the complexes were characterized by elemental analysis, IR data, and molar conductivity. The binding of these four complexes to calf‐thymus DNA was carefully investigated by UV/VIS spectroscopy, fluorescence spectroscopy, viscosity measurements, and CD spectra. The experimental results indicate that the four complexes bind to calf‐thymus DNA in an intercalative mode, with the intrinsic binding constants (K) of 3.94⋅104 ([NiL1]), 5.15⋅103 ([ZnL1]), 4.12⋅104 ([NiL2]), and 3.75⋅104 M−1 ([ZnL2]). These data show that the complexes of L2 can interact more strongly with DNA than complexes of L1, and the NiII complexes have a higher binding constant than ZnII complexes.
Acylation of a 6‐(Methylamino)‐5‐nitrosopyrimidine and 1,3‐Dipolar Cycloaddition of an 8‐Methylisoxanthopterin N(5)‐Oxide. Synthesis of C(6),N(8)‐Disubstituted Isoxanthopterins
Authors: Steinlin Thomas , Vasella Andrea 
Published: March 2009

Abstractmagnified imageAcylation of 2‐amino‐4‐(benzyloxy)‐6‐(methylamino)‐5‐nitrosopyrimidine (5) with acetic anhydride or chloroacetic anhydride in the presence of 4‐(dimethylamino)pyridine (DMAP) led to the C(2)‐acylamino derivatives 6 and 7, respectively. In the absence of a base, acetylation did not lead to a product, while chloroacetylation led to the 6‐chloropteridine 11. Chloroacetylation in the presence of Hünig's base provided the pteridinone N(5)‐oxide 10, suggesting that acylation of 5 is readily reversible, and that the unfavourable equilibrium must be displaced by a follow‐up reaction to trap the acylation product. Acylation of 5 with hexadienoyl chloride, followed by intramolecular Diels–Alder reaction, provided the pteridinone 12. A high yielding 1,3‐dipolar cycloaddition of the acylnitrone 10 to electron‐poor and electron‐rich dipolarophiles, followed by spontaneous N,O‐bond cleavage, gave the C(6)‐substituted pteridinones 19a–19e that were deprotected to the pteridine‐4,7(3H,8H)‐diones 20a–20e. Substitution of the 6‐chloropterin 11 provided the 6‐morpholinopteridine 25. Sonogashira coupling yielded the fluorescent [(pteridin‐6‐yl)ethynyl]‐glucopyranoside 26, 6‐ethynylpteridine 28, and 6,6′‐(ethynediyl)bispteridine 29. The alkyne 28 reacted with Me3SiCl and LiBr in MeCN to produce the bromoalkene 31.
Trust‐based or performance‐based management—a study of employment contracting in hospitals
Authors: Pettersen Inger Johanne 
Published: March 2009

AbstractHospitals are frequently changing managerial practices due to numerous public sector reforms taking place. In general, these reforms include the making and monitoring of contracts that regulate relations between the hospitals and their professional staffs.The aim of this paper is to discuss some main characteristics of the contracts that regulate the perceived relations between physicians as employees and the public hospital as employer. The theoretical framework is based on a contract theory approach. The empirical data is based on survey data from full‐time employed physicians in the medical and surgical divisions in one of the largest university hospitals in Norway. This study shows that perceived obligations and psychological contracts indicate high degree of relational contracts between the hospital and the physicians. These socio‐cultural elements should be recognized as important mechanisms of coordination and communication when policy makers and hospital managers are designing hospital management control systems. Copyright © 2009 John Wiley & Sons, Ltd.
Profit‐sharing plans and affective commitment: Does the context matter?
Authors: Bayo‐Moriones Alberto , Larraza‐Kintana Martin 
Published: March 2009

AbstractThis article analyzes the relationship between profit‐sharing plans (PSP) and affective commitment and how it is affected by the context of the PSP application. Overall, there is a positive relationship between profit sharing and commitment that is strongest in very small firms. The efficacy of a PSP in improving employees' affective commitment appears to be greatest in firms with low job‐related employee participation. Its application in workplaces where employees enjoy high levels of participation appears to have little impact and may even result in slight declines in affective commitment. © 2009 Wiley Periodicals, Inc.
Effectiveness of organizational efforts to lower turnover intentions: The moderating role of employee locus of control
Authors: Ng Thomas W. H. , Butts Marcus M. 
Published: March 2009

AbstractIn the current career climate characterized by change and turbulence, employees may demonstrate limited psychological attachment to their employers. Rousseau (1998) suggested that organizations can elicit psychological attachment from employees by reinforcing perceptions of organizational membership and demonstrating care and support for them. The effectiveness of these strategies, however, may depend on individuals' personality traits. In this study, we examined the moderating effect of locus of control in the relationship among four valued aspects of the work environment—information sharing, job significance, opportunity for learning, and availability of rewards for performance—and employees' intentions to stay. In two empirical studies, we found that information sharing, job significance, and locus of control interacted to positively affect intentions to stay and that opportunity for learning, availability of rewards for performance, and locus of control also interacted to increase intentions to stay. Implications of these results for theory building and practice are discussed. © 2009 Wiley Periodicals, Inc.
Seasonal hyporheic temperature dynamics over riffle bedforms
Authors: Hannah David M. , Malcolm Iain A. , Bradley Chris 
Published: March 2009

AbstractThere is growing interest in riverbed temperature due to the ecological and biogeochemical significance of the hyporheic zone, and its potential to moderate river temperature. Riffles exhibit complex thermal behaviour, hypothesized to be caused by local alteration of groundwater–surface water (GW–SW) interactions, but hitherto most research has been in upland/gravel‐bed/hard rock catchments. Accordingly, this article aims: (1) to characterize spatio‐temporal variability in hyporheic temperature over two riffles (R1 and R2) in a lowland river basin (Tern, Shropshire, UK) underlain by sandstone, and (2) to explain thermal dynamics by inferring hyporheic processes and the influence of GW–SW interactions. Hyporheic (riffle head, crest and tail at 0·1, 0·2 and 0·4 m), water column, spring water and air temperature were collected at 15 min resolution over 22 months and used to explore seasonal variations. Borehole water levels and temperature provide insight into groundwater variability over a hydrological year. Hyporheic temperature is cooler (warmer) than water column in summer (winter), with convergence in spring and autumn. Riffle heads and R2 crest yield small thermal gradients, and R1 tail larger vertical difference. R1 crest temperature is similar and attenuated (cf. water column) at all depths. R2 tail temperature differs markedly from surface water. Thus, hyporheic temperature varies temporally across and between riffles, reflecting: (1) hydroclimatological controls on river and groundwater temperature, and (2) hydrological, local morphological and sedimentary controls on surface water and groundwater flux. This research demonstrates the utility of depth‐related riverbed temperature time‐series in understanding hyporheic zone processes and GW–SW interactions. Copyright © 2009 John Wiley & Sons, Ltd.
High‐temperature beverages and foods and esophageal cancer risk—A systematic review
Authors: Islami Farhad , Boffetta Paolo , Ren Jian‐Song , Pedoeim Leah , Khatib Dara , Kamangar Farin 
Published: March 2009

AbstractCoffee, tea and maté may cause esophageal cancer (EC) by causing thermal injury to the esophageal mucosa. If so, the risk of EC attributable to thermal injury could be large in populations in which these beverages are commonly consumed. In addition, these drinks may cause or prevent EC via their chemical constituents. Therefore, a large number of epidemiologic studies have investigated the association of an indicator of amount or temperature of use of these drinks or other hot foods and beverages with risk of EC. We conducted a systematic review of these studies and report the results for amount and temperature of use separately. By searching PubMed and the ISI, we found 59 eligible studies. For coffee and tea, there was little evidence for an association between amount of use and EC risk; however, the majority of studies showed an increased risk of EC associated with higher drinking temperature which was statistically significant in most of them. For maté drinking, the number of studies was limited, but they consistently showed that EC risk increased with both amount consumed and temperature, and these 2 were independent risk factors. For other hot foods and drinks, over half of the studies showed statistically significant increased risks of EC associated with higher temperature of intake. Overall, the available results strongly suggest that high‐temperature beverage drinking increases the risk of EC. Future studies will require standardized strategies that allow for combining data and results should be reported by histological subtypes of EC. © 2009 UICC
Posttranslational regulation of Myc by promyelocytic leukemia zinc finger protein
Authors: Shi Jin , Vogt Peter K. 
Published: March 2009

AbstractThe promyelocytic leukemia zinc finger (PLZF) protein, a transcriptional repressor, induces cellular resistance to oncogenic transformation by diverse oncoproteins. Two point mutants of PLZF that have lost the antioncogenic activity of the wild‐type protein are oncogenic in chicken embryo fibroblasts; this activity is correlated with differential effects on Myc. Wild‐type PLZF represses Myc transcription without affecting total Myc protein levels and reduces the levels of phosphorylated Myc. The PLZF mutants do not alter Myc transcription or protein expression but increase the levels of phosphorylated Myc. These modifications of Myc are correlated with PLZF‐induced changes in Akt and the mitogen‐activated protein kinase (MAPK) pathway. Wild‐type PLZF downregulates the MAPK pathway and activates Akt, resulting in reduced phosphorylation on serine 62 of Myc by Erk and on threonine 58 by glycogen synthase kinase 3β. The mutants fail to activate Akt and only slightly downregulate phospho‐Erk. We postulate that the 2 PLZF mutants are oncogenic, because they function as dominant negatives of wild‐type PLZF, enhancing Myc phosphorylation and increasing Myc transcriptional and oncogenic activity. In support of this suggestion, a specific inhibitor of Myc is able to revert the transformed phenotype of PLZF mutant‐expressing cells. © 2009 UICC
CD4+ lymphocytes modulate prostate cancer progression in mice
Authors: Poutahidis Theofilos , Rao Varada P. , Olipitz Werner , Taylor Christie L. , Jackson Erin A. , Levkovich Tatiana , Lee Chung Wei , Fox James G. , Ge Zhongming , Erdman Susan E. 
Published: March 2009

AbstractChronic inflammation contributes to the development of prostate cancer in humans. Here, we show that male ApcMin/+ mice also develop prostate carcinoma with increasing age, mimicking that seen in humans in their 5th or 6th decade of life. Proinflammatory cytokines were significantly linked with cancer and increasing age in our mouse model; however, prostate and bowel tissues lacked evidence of inflammatory cell infiltrates other than mast cells. Lymphocytes protected against cancer, and protection from prostate cancer resided in antiinflammatory CD4+CD25+ regulatory (TREG) cells that downregulated inflammatory cytokines. Supplementation with syngeneic TREG cells collected from wild‐type mice reduced the levels of interleukin (IL)‐6 (p < 0.05) and IL‐9 (p < 0.001) and lowered prostate cancer risk (p < 0.05). Depletion of CD25+ cells in 2‐month‐old animals increased the expression of IL‐6 (p < 0.005) within prostate and increased the frequency of high‐grade prostatic intraepithelial neoplasia (p < 0.05) and microinvasive prostatic carcinoma (p < 0.05) in dorsolateral prostate. Depletion of CD25+ cells in young animals also increased the frequency of intestinal cancer in Min mice. Taken together, chronically elevated proinflammatory cytokines promoted carcinoma in ApcMin/+ mice. TREG lymphocytes downregulated inflammation‐associated carcinogenic processes and contributed to immune and epithelial homeostasis. © 2009 UICC
Clinicopathological significance of stanniocalcin 2 gene expression in colorectal cancer
Authors: Ieta Keisuke , Tanaka Fumiaki , Yokobori Takehiko , Kita Yoshiaki , Haraguchi Naotsugu , Mimori Koshi , Kato Hiroyuki , Asao Takayuki , Inoue Hiroshi , Kuwano Hiroyuki , Mori Masaki 
Published: March 2009

AbstractLaser microdissection (LMD) and microarray were used to identify genes associated with colorectal cancer. Stanniocalcin 2 (STC2) expression and clinicopathological significance in 139 clinical colorectal cancer samples were specifically investigated using real‐time quantitative reverse transcription‐polymerase chain reaction. A number of genes upregulated in colorectal cancer cells compared to normal colorectal epithelial cells were identified including STC2. STC2 gene expression in cancer tissue was higher than in corresponding normal colorectal epithelial tissue in 124 of 139 cases (89.2%, p < 0.01). Tumors with high STC2 expression showed higher frequencies of lymph node metastasis, lymphatic invasion, tumor depth, tumor size and AJCC Stage classification (p < 0.01). Patients with high STC2 expression also showed significantly worse overall survival rates than those with low STC2 expression (p < 0.01). Furthermore, STC2 gene appeared to be associated with colorectal cancer progression and may be a useful prognostic indicator for colorectal cancer. © 2009 UICC
Common immune‐related risk factors and incident non‐Hodgkin lymphoma: The multiethnic cohort
Authors: Erber Eva , Lim Unhee , Maskarinec Gertraud , Kolonel Laurence N. 
Published: March 2009

AbstractSevere immune dysfunction is an established risk factor of lymphoma, but the role of moderate alterations of immunity is not clear and prospective investigations are needed. We examined several immune‐related disorders and medications in relation to non‐Hodgkin lymphoma (NHL) in the Multiethnic Cohort. Over 215,000 subjects of African American, Caucasian, Japanese American, Latino and Native Hawaiian ancestry aged 45–75 years completed a questionnaire, including information on medical history, in 1993–1996. After exclusions, we performed Cox regression among 193,050 cohort members including 939 incident NHL cases while adjusting for sex, age, ethnicity, education, body mass index and alcohol intake. Self‐reported diabetes was not associated with NHL overall, but was positively associated with risk among Japanese Americans [hazard ratio (HR) = 1.55; 95% confidence interval (CI): 1.10–2.17]. Participants with a history of blood transfusion were at increased risk with HR = 1.39 (95% CI: 1.06–1.84) in men and HR = 1.22 (95% CI: 0.94–1.58) in women, especially for the diffuse large B‐cell lymphoma subtype. History of asthma or other allergies was associated with elevated risk only among Latinos (HR = 1.46; 95% CI: 1.07–2.00) who also showed a significant relation between current use of antihistamines and NHL (HR = 1.80; 95% CI: 1.09–2.97). Use of nonsteroidal anti‐inflammatory drugs was not associated with NHL. Our findings from this large prospective study support a moderate risk for NHL related to blood transfusions, current long‐term antihistamine use and diabetes, but the associations were limited to certain ethnic groups and require further replications. © 2009 UICC
A comparative biochemical analysis of glycosaminoglycans and proteoglycans in human orthotopic and heterotopic bone
Authors: Mania Vassiliki M. , Kallivokas Alkiviadis G. , Malavaki Christina , Asimakopoulou Athanasia P. , Kanakis John , Theocharis Achilleas D. , Klironomos George , Gatzounis George , Mouzaki Athanasia , Panagiotopoulos Elias , Karamanos Nikos K. 
Published: March 2009

AbstractGlycosaminoglycans and proteoglycans are macromolecules of the bone and are involved in the assembly, maturation, mineralization, and maintenance of the extracellular matrix. Heterotopic ossification is the rapid development of calcified bone tissue at ectopic sites of the body, mainly in soft tissues that normally do not ossify. The aim of this study was to characterize the molecular profiles of glycosaminoglycans and proteoglycans in normal and heterotopic bone samples to assess whether differences exist between orthotopic and heterotopic bone. Heterotopic bone tissues contained lower amounts of glycosaminoglycans compared to normal femoral bone. Structural analysis of chondroitin sulfate (CS) revealed that both heterotopic and normal femoral bones were composed mainly of 6‐sulfated disaccharides. Quantitative differences in the disaccharide composition of CS, such as the decrease of 6‐sulfated disaccharides in heterotopic bone with a concurrent increase of 4‐sulfated and nonsulfated disaccharides, were found between ectopic bone and normal femoral bone. The proteoglycans decorin and aggrecan were both detected in all bone samples using specific antibodies. The detection of minor amounts of aggrecan in mature human bone, such as femoral bone, as well as in ectopic bone is described for the first time. These results may elucidate the phenomenon of ectopic bone formation and assist in early detection. © 2009 IUBMB IUBMB Life, 61(4): 447–452, 2009
A‐kinase anchoring proteins: From protein complexes to physiology and disease
Authors: Carnegie Graeme K. , Means Christopher K. , Scott John D. 
Published: March 2009

AbstractProtein scaffold complexes are a key mechanism by which a common signaling pathway can serve many different functions. Sequestering a signaling enzyme to a specific subcellular environment not only ensures that the enzyme is near its relevant targets, but also segregates this activity to prevent indiscriminate phosphorylation of other substrates. One family of diverse, well‐studied scaffolding proteins are the A‐kinase anchoring proteins (AKAPs). These anchoring proteins form multi‐protein complexes that integrate cAMP signaling with other pathways and signaling events. In this review, we focus on recent advances in the elucidation of AKAP function. © 2009 IUBMB IUBMB Life, 61(4): 394–406, 2009
Recent advances in understanding the structure of nicotinic acetylcholine receptors
Authors: Zouridakis Marios , Zisimopoulou Paraskevi , Poulas Konstantinos , Tzartos Socrates J. 
Published: March 2009

AbstractNicotinic acetylcholine receptors (nAChRs), members of the Cys‐loop ligand‐gated ion channels (LGICs) superfamily, are involved in signal transduction upon binding of the neurotransmitter acetylcholine or exogenous ligands, such as nicotine. nAChRs are pentameric assemblies of homologous subunits surrounding a central pore that gates cation flux, and are expressed at the neuromuscular junction and in the nervous system and several nonneuronal cell types. The 17 known nAChR subunits assemble into a variety of pharmacologically distinct receptor subtypes. nAChRs are implicated in a range of physiological functions and pathophysiological conditions related to muscle contraction, learning and memory, reward, motor control, arousal, and analgesia, and therefore present an important target for drug research. Such studies would be greatly facilitated by knowledge of the high‐resolution structure of the nAChR. Although this information is far from complete, important progress has been made mainly based on electron microscopy studies ofTorpedonAChR and the high‐resolution X‐ray crystal structures of the homologous molluscan acetylcholine‐binding proteins, the extracellular domain of the mouse nAChR α1 subunit, and two prokaryotic pentameric LGICs. Here, we review some of the latest advances in our understanding of nAChR structure and gating. © 2009 IUBMB IUBMB Life, 61(4): 407–423, 2009