bluuebunny/crossref_metadata_2025 huggingface dataset:
Survival and prognostic factors in patients with small bowel carcinoid tumour
Authors: Landerholm K , Zar N , Andersson R E , Falkmer S E , Järhult J
Published: August 2011

Background

Previous studies of small bowel carcinoid tumours usually presented overall or relative survival. This study, in addition, evaluated disease-specific survival in a cohort of patients in a geographically defined population.

Methods

Patients diagnosed with carcinoid of the jejunum or ileum in Jönköping County between 1960 and 2005 were eligible for inclusion. Available tumour specimens were re-examined to confirm the diagnosis. Medical records and pathology reports were reviewed in detail.

Results

A total of 145 patients were included in the study. One hundred and thirty-five patients underwent surgery in connection with the diagnosis. Resection was considered complete (R0) in 74 patients (54·8 per cent). Only two localized tumours recurred, whereas no patient with distant metastases was cured. Patients with regional metastases who underwent R0 resection had a better survival than patients with incomplete resection (P = 0·005), and a majority of patients remained recurrence-free. Median overall survival was 7·2 years and median disease-specific survival 12·3 years. In multivariable analysis, age 61–74 years (hazard ratio (HR) 3·78, 95 per cent confidence interval 1·86 to 7·68), age 75 years or more (HR 3·96, 1·79 to 8·74), distant metastases (HR 14·44, 1·59 to 131·36) and incomplete tumour resection (HR 2·71, 1·11 to 6·61) were associated with worse disease-specific survival. Later time period of diagnosis (HR 0·45, 0·24 to 0·84) was associated with better disease-specific survival.

Conclusion

Age, disease stage and complete resection were identified as independent prognostic factors for survival in patients with small bowel carcinoid tumours. The importance of achieving R0 resection is therefore emphasized.
Impact of breast surgery on survival in women presenting with metastatic breast cancer
Authors: Pathy N Bhoo , Verkooijen H M , Taib N A , Hartman M , Yip C H
Published: August 2011

Background

Advanced breast cancer is common in less affluent parts of Asia. The impact of breast surgery on survival of women presenting with metastatic breast cancer in this setting was investigated.

Methods

Women presenting with metastatic breast cancer at the initial diagnosis at the University Malaya Medical Centre (Malaysia) between 1993 and 2008 were included in the study. Mortality of patients who had primary breast surgery was compared with that of those without surgery, and adjusted for possible confounders by means of a propensity score.

Results

Of 3689 patients, 375 (10·2 per cent) presented with metastatic disease. One hundred and thirty-nine patients (37·1 per cent) underwent surgery. A total of 330 deaths occurred during 6814 person-months of follow-up. The 2-year survival rate was 21·2 (95 per cent confidence interval (c.i.) 15·9 to 26·5) per cent in women who did not have surgery and 46·3 (37·7 to 54·9) per cent in those who had breast surgery. Breast surgery was associated with a 28 per cent lower risk of death (hazard ratio 0·72, 95 per cent c.i. 0·56 to 0·94), after adjustment for patient and tumour characteristics, metastatic profile and treatment.

Conclusion

Surgical resection of the primary breast tumour was independently associated with a survival advantage in patients presenting with metastatic breast cancer.
Persisting or Withdrawing? An Insight into the Psychosocial Processes Underlying Sustained Engagement
Authors: Mannarini Terri , Fedi Angela
Published: August 2011

The study explored the roles of commitment, emotional stress, and interpersonal relationships in sustaining individuals' engagement in collective action. Two collective action cases, differing in duration, issue, and territorial rootedness, were analyzed. The processes underlying sustained engagement were probed in 32 semistructured interviews conducted with antiglobalization activists (N = 13) and opponents to a high‐speed railroad (N = 19). Our findings showed that collective action can be stressful, but that there are proximal and distal factors that can counterbalance the disruption and sustain engagement. The proximal factors are embedded in the circumstances of involvement, and these factors concern interpersonal relationships, organizational mechanisms, and the psychological interface between the individuals and the concrete collective action environment. The distal factors are related partly to the individual and partly to the broader community from which the individual absorbs general values and norms. Copyright © 2011 John Wiley & Sons, Ltd.
Epinephrine‐induced MMP expression is different between skeletal fibroblasts and myoblasts
Authors: Cha M. C. , Purslow P. P.
Published: August 2011

Skeletal fibroblasts and myoblasts are among the cell types currently being considered in cell therapy for ischaemic heart disease. To investigate whether the expression of the tissue‐remodelling proteolytic enzymes matrix metalloproteinases (MMPs) and the cellular energy regulator AMP‐activated protein kinase (AMPK) is comparable between the two cell lines in response to epinephrine treatment, mouse skeletal fibroblasts (NOR‐10) and myoblasts (C2C12) were treated with or without a low (11 nmol·l‐1) or high (55 nmol·l‐1) dose of epinephrine for 2 or 6 h. Cellular MMP‐3 expression was increased by the high‐dose epinephrine at both treatment periods in both cell lines. Cellular MMP‐2 and MMP‐13 expressions were amplified by the 2‐ or 6‐h epinephrine incubation in fibroblasts. However, in myoblasts, such an increase was only seen at the longer treatment time. An elevated AMPKα expression was observed after a 2‐h presence of epinephrine in both cell lines, which matches temporally with the early increased cellular MMP‐2 and MMP‐13 expression in fibroblasts. Activity of secreted MMP‐2 increased only after 6‐h epinephrine treatment in both cell types. Our data suggest that skeletal fibroblasts respond earlier to epinephrine application in terms of endogenous synthesis of the proteolytic and the energy homeostasis enzymes, whereas such response occurs later and to a milder dose of the beta adrenergic agonist in myoblasts. Copyright © 2011 John Wiley & Sons, Ltd.
Sponge Biosilica Formation Involves Syneresis Following Polycondensation in vivo
Authors: Wang Xiaohong , Schröder Heinz C. , Brandt David , Wiens Matthias , Lieberwirth Ingo , Glasser Gunnar , Schloßmacher Ute , Wang Shunfeng , Müller Werner E. G.
Published: August 2011

Syneresis is a process observed during the maturation/aging of silica gels obtained by sol–gel synthesis that results in shrinkage and expulsion of water due to a rearrangement and increase in the number of bridging siloxane bonds. Here we describe how the process of biosilica deposition during spicule (“biosilica” skeleton of the siliceous sponges) formation involves a phase of syneresis that occurs after the enzyme‐mediated polycondensation reaction. Primmorphs from the demosponge Suberites domuncula were used to study syneresis and the inhibition of this mechanism. We showed by scanning electron microscopy that spicules added to primmorphs that have been incubated with manganese sulfate fuse together through the deposition of silica spheres and bridges. Energy‐dispersive X‐ray mapping of the newly formed deposits showed high silicon and oxygen content. These biosilica deposits contain a comparably higher percentage of water than mature/aged spicules. Quantitative real‐time polymerase chain reaction analyses revealed that the addition of silicate to primmorph cultures resulted in a marked upregulation of the expression of the aquaporin gene and of the genes encoding the silica anabolic enzyme silicatein‐α and the silica catabolic enzyme silicase. On the other hand, addition of manganese sulfate, either alone or together with silicate, caused a strong reduction in the level of aquaporin transcripts, although this metal ion did not essentially affect the silicate‐induced increase in silicatein‐α and silicase gene expression. We conclude that the secondary silica deposits formed on spicules under physiological conditions in the presence of silicate fuse together and subsequently undergo syneresis, which is facilitated by the removal of water through aquaporin channels. In growing spicules, these processes of biosilica formation and syneresis in the lamellar monolithic structures precede the final step of “biosintering” during which the massive biosilica rods of the spicules are formed.
Trigeminal and telencephalic projections to jaw and other upper vocal tract premotor neurons in songbirds: Sensorimotor circuitry for beak movements during singing
Authors: Wild J.M. , Krützfeldt N.E.O.
Published: August 2011

During singing in songbirds, the extent of beak opening, like the extent of mouth opening in human singers, is partially correlated with the fundamental frequency of the sounds emitted. Since song in songbirds is under the control of “the song system” (a collection of interconnected forebrain nuclei dedicated to the learning and production of song), it might be expected that beak movements during singing would also be controlled by this system. However, direct neural connections between the telencephalic output of the song system and beak muscle motor neurons in the brainstem are conspicuous by their absence, leaving unresolved the question of how beak movements are affected during singing. By using standard tract tracing methods, we sought to answer this question by defining beak premotor neurons and examining their afferent projections. In the caudal medulla, jaw premotor cell bodies were located adjacent to the terminal field of the output of the song system, into which many premotor neurons extended their dendrites. The premotor neurons also received a novel input from the trigeminal ganglion and an overlapping input from a lateral arcopallial component of a trigeminal sensorimotor circuit that traverses the forebrain. The ganglionic input in songbirds, which is not present in doves and pigeons that vocalize with a closed beak, may modulate the activity of beak premotor neurons in concert with the output of the song system. These inputs to jaw premotor neurons could, together, affect beak movements as a means of modulating filter properties of the upper vocal tract during singing. J. Comp. Neurol. 520:590–605, 2012. © 2011 Wiley Periodicals, Inc.
Reelin demarcates a subset of pre‐Bötzinger complex neurons in adult rat
Authors: Tan Wenbin , Sherman David , Turesson Jenny , Shao Xuesi M. , Janczewski Wiktor A. , Feldman Jack L.
Published: August 2011

Identification of two markers of neurons in the pre‐Bötzinger complex (pre‐BötC), the neurokinin 1 receptor (NK1R) and somatostatin (Sst) peptide, has been of great utility in understanding the essential role of the pre‐BötC in breathing. Recently, the transcription factor dbx1 was identified as a critical, but transient, determinant of glutamatergic pre‐BötC neurons. Here, to identify additional markers, we constructed and screened a single‐cell subtractive cDNA library from pre‐BötC inspiratory neurons. We identified the glycoprotein reelin as a potentially useful marker, because it is expressed in distinct populations of pre‐BötC and inspiratory bulbospinal ventral respiratory group (ibsVRG) neurons. Reelin ibsVRG neurons were larger (27.1 ± 3.8 μm in diameter) and located more caudally (>12.8 mm caudal to Bregma) than reelin pre‐BötC neurons (15.5 ± 2.4 μm in diameter, <12.8 mm rostral to Bregma). Pre‐BötC reelin neurons coexpress NK1R and Sst. Reelin neurons were also found in the parahypoglossal and dorsal parafacial regions, pontine respiratory group, and ventromedial medulla. Reelin‐deficient (Reeler) mice exhibited impaired respones to hypoxia compared with littermate controls. We suggest that reelin is a useful molecular marker for pre‐BötC neurons in adult rodents and may play a functional role in pre‐BötC microcircuits. J. Comp. Neurol. 520:606–619, 2012. © 2011 Wiley Periodicals, Inc.
Subdivisions of the adult zebrafish subpallium by molecular marker analysis
Authors: Ganz Julia , Kaslin Jan , Freudenreich Dorian , Machate Anja , Geffarth Michaela , Brand Michael
Published: August 2011

The morphology of the telencephalon displays great diversity among different vertebrate lineages. Particularly the everted telencephalon of ray‐finned fishes shows a noticeably different morphology from the evaginated telencephalon of nonray‐finned fishes and other vertebrates. This makes the comparison between the different parts of the telencephalon of ray‐finned fishes and other vertebrates difficult. Based on neuroanatomical, neurochemical, and connectional data no consensus on the subdivisions of the adult telencephalon of ray‐finned fishes and their relation to nuclei in the telencephalon of other vertebrates has been reached yet. For tetrapods, comparative expression pattern analysis of homologous developmental genes has been a successful approach to clarify homologies between different parts of the telencephalon. In the larval zebrafish, subdivisions of the subpallium have been proposed using conserved developmental gene expression. In this study, we investigate the subdivisions of the adult zebrafish telencephalon by analyzing the expression pattern of conserved molecular marker genes. We identify the boundary between the pallium and subpallium based on the complementary expression of dlx2a, dlx5a in the subpallium and tbr1, neurod in the pallium. Furthermore, combinatorial expression of Isl, nkx2.1b, lhx1b, tbr1, eomesa, emx1, emx2, and emx3 identifies striatal‐like, pallidal‐like, and septal‐like subdivisions within the subpallium. In contrast to previous models, we propose that the striatum and pallidum are stretched along the rostrocaudal axis of the telencephalon. Further, the septal nuclei derive from both the pallium and subpallium. On this basis, we present a new model for the subdivisions of the subpallium in teleost fish. J. Comp. Neurol. 520:633–655, 2012. © 2011 Wiley Periodicals, Inc.
IBC‐HWMP: a novel secure identity‐based cryptography‐based scheme for Hybrid Wireless Mesh Protocol for IEEE 802.11s
Authors: Ben‐Othman Jalel , Saavedra Benitez Yesica I.
Published: August 2011

The IEEE P802.11s/D4.0 standard is not considered secure for the routing protocol. In this paper, we propose IBC‐HWMP, a secure Hybrid Wireless Mesh Protocol (HWMP) using identity‐based cryptography (IBC). The reason we use IBC is that it does not need to verify the authenticity of public keys. We have implemented the IBC mechanism to secure control messages in HWMP, namely path request and path reply. Our aim is to focus on secure data exchange in mutable fields. Through extensive ns‐3 simulations, results show that the overhead introduced by IBC‐HWMP is not significant compared with the classical HWMP and that, at the same time, we improve the security. Copyright © 2011 John Wiley & Sons, Ltd.
Two‐Photon STED Spectral Determination for a New V‐Shaped Organic Fluorescent Probe with Efficient Two‐Photon Absorption
Authors: Belfield Kevin D. , Bondar Mykhailo V. , Morales Alma R. , Padilha Lazaro A. , Przhonska Olga V. , Wang Xuhua
Published: August 2011

Two‐photon stimulated emission depletion (STED) cross sections were determined over a broad spectral range for a novel two‐photon absorbing organic molecule, representing the first such report. The synthesis, comprehensive linear photophysical, two‐photon absorption (2PA), and stimulated emission properties of a new fluorene‐based compound, (E)‐2‐{3‐[2‐(7‐(diphenylamino)‐9,9‐diethyl‐9H‐fluoren‐2‐yl)vinyl]‐5‐methyl‐4‐oxocyclohexa‐2,5‐dienylidene} malononitrile (1), are presented. Linear spectral parameters, including excitation anisotropy and fluorescence lifetimes, were obtained over a broad range of organic solvents at room temperature. The degenerate two‐photon absorption (2PA) spectrum of 1 was determined with a combination of the direct open‐aperture Z‐scan and relative two‐photon‐induced fluorescence methods using 1 kHz femtosecond excitation. The maximum value of the 2PA cross section ∼1700 GM was observed in the main, long wavelength, one‐photon absorption band. One‐ and two‐photon stimulated emission spectra of 1 were obtained over a broad spectral range using a femtosecond pump–probe technique, resulting in relatively high two‐photon stimulated emission depletion cross sections (∼1200 GM). A potential application of 1 in bioimaging was demonstrated through one‐ and two‐photon fluorescence microscopy images of HCT 116 cells incubated with micelle‐encapsulated dye.
1,3,2‐Diselenaborolanes with an Annelated Dicarba‐closo‐dodecaborane(12) Unit: Synthesis, Molecular Structure and Reactivity
Authors: Wrackmeyer Bernd , Klimkina Elena V. , Milius Wolfgang
Published: August 2011

Exchange reactions of 2,2‐dimethyl‐1,3‐diselena‐2‐silacyclopentane and 2,2,3,3‐tetramethyl‐1,4‐diselena‐2,3‐disilacyclohexane, as the 4,5‐ and 5,6‐[1,2‐dicarba‐closo‐dodecaborano(12)] derivatives, respectively, with boron trihalides (BCl3, BBr3, BI3) and dichlorides (PhBCl2,iPr2NBCl2) afford the corresponding 1,3,2‐diselenaborolanes in essentially quantitative yield. The products were characterized in solution by multinuclear magnetic resonance spectroscopy (1H,11B,13C,29Si,77Se), and for two products, in the solid state by X‐ray structural analysis. Attempts to synthesize the boron fluoride failed, and the methoxy derivative was obtained in a mixture with a decomposition product. The gas‐phase structures of all relevant products were optimized by DFT hybrid methods [RB3LYP/6‐311+G(d.p) level of theory], and NMR parameters (shielding constants and spin–spin coupling constants) were calculated. The calculated data compare well with experimental data, both for the structures and the NMR spectroscopic parameters.
Nutritive value of canola (Brassica napusL.) as affected by plant growth promoting rhizobacteria
Authors: Nosheen Asia , Bano Asghari , Ullah Faizan
Published: August 2011

Comparative evaluation of plant growth promoting rhizobacteria viz.Azospirillum brasilense,Azotobacter vinelandiiKhsr1 and chemical fertilizers was made on growth, protein, and oil yield as well as quality of canola (Brassica napusL.) cv. Rainbow. TheA. brasilenseandA. vinelandiiwere applied as seed inoculation at 106 cells/mL. The recommended doses of urea (150 kg/ha) and diamonium phosphate (180 kg/ha) were applied as sources of chemical fertilizers. First dose of chemical fertilizers was applied at the time of sowing while other three doses were applied at 45 days interval. The chemical fertilizers were highly effective in increasing leaf chlorophyll content, number of branches per plant, number of siliqua per branch, number of seeds per siliqua, and total seed yield.A. brasilensetreatment increased the leaf and seed protein content (32 and 21%) as well as seed size as measured by % increase in 1000 seed weight.A. vinelandiitreatment resulted in significant increase (4%) in seed oil contents but the glucosinolate and erucic acid (C22:1) contents of oil was decreased significantly. Maximum oleic acid (C18:1) content was found in seed oil ofA. vinelandiitreatment; whereas, significantly higher linolenic acid (C18:3) content was recorded inA. brasilensetreatment. It is inferred from the present investigation thatA. brasilenseandA. vinelandiicould be highly effective in improving yield and nutritive value of canola oil.
Cytotoxic complexes of sodium oleate with β‐lactoglobulin
Authors: Lišková Kamila , Auty Mark A. E. , Chaurin Valérie , Min Soyoung , Mok K. Hun , O'Brien Nora , Kelly Alan L. , Brodkorb André
Published: August 2011

A complex of α‐lactalbumin and oleic acid has previously been shown to induce apoptosis in cancer cells in a number of in vitro and in vivo trials. This complex is called HAMLET or BAMLET, depending on the origin of α‐la (human/bovine alpha‐lactalbumin made lethal to tumour cells). In the current study, it was shown that bovine β‐lactoglobulin (β‐lg), upon binding sodium oleate (NaOle), the salt of oleic acid, also acquires cytotoxicity towards tumour cells (human monocytic cells U937), analogously to HAMLET/BAMLET complexes. The properties of the complex were characterized using FIR spectroscopy, HPLC and SDS‐PAGE. It was shown that the level of covalent oligomerization (dimers and trimers) of β‐lg increased with increasing the molar ratio of sodium oleate NaOle:β‐lg in the preparation procedure. At the same time, increasing the molar ratio of NaOle:β‐lg increased the cytotoxicity of the complex. The increase in cytotoxicity appeared to be dependent on the amount of bound NaOle in the complex, but not on the content of multimeric forms of β‐lg. The NaOle/β‐lg complex also showed similarity with BAMLET in penetrating the cell membrane and co‐localizing with the cell nucleus. Furthermore, DNA fragmentation studies suggested that tumour cells (U937) treated with the complex died by apoptosis, as in the case of BAMLET, and healthy cells appeared to be less affected by treatment, as shown with model rat adrenal pheochromocytoma cells PC12. In conclusion, β‐lg and NaOle can form complexes with apoptosis‐inducing qualities comparable to those of BAMLET.

Practical applications: Globular proteins such as the milk proteins α‐lactalbumin and β‐lactoglobulin can bind oleic acid, thereby converting into a complex with high biological activity against tumour cells. Its cytotoxicity is strongly dependent on the binding stoichiometry, indicating the importance of oleic acid in the cell death.
Structural Effects on the Physico‐Chemical and Catalytic Properties of Acidic Ionic Liquids: An Overview
Authors: Chiappe Cinzia , Rajamani Sunita
Published: August 2011

Acidic ionic liquids (ILs) are key systems in synthesis and their performances depend greatly on their cation and anion structure and their liquid‐state organization. This microreview reports several examples of Brønsted and/or Lewis acidic ILs that have been selected to highlight the main peculiarities of these systems potentially fundamental for rational design and development of new ionic media and catalysts. Fundamental physico‐chemical properties, optimization of which through tailoring of molecular structures could favor more efficient and sustainable applications, are discussed.
Application of Current Fluxes to the Characterization of Ion Transfer at Solvent Polymeric Membranes with One and Two Polarized Interfaces
Authors: Torralba E. , Ortuño J. A. , Serna C. , González J. , Molina A.
Published: August 2011

Chronopotentiometric and reciprocal derivative chronopotentiometric E–t, dt/dE–E and dI/dE–E responses are analyzed for the ion transfer of a series of tetraalkylammonium cations and tricyclic catamphiphilic drugs, driven by an exponential and a constant current flux in a liquid membrane system of one and two polarized interfaces. Reciprocal derivative chronopotentiometry shows a strong resolving power, since the dt/dE–E and dI/dE–E responses obtained with this technique are narrower than those provided by some of the more powerful voltammetric techniques, like square wave voltammetry and differential pulse voltammetry. From the experimental results we have obtained the standard ion transfer potential of the different ions assayed.
Direct Electrochemistry and Application in Electrocatalysis of Hemoglobin in a Polyacrylic Resin‐Gold Colloid Nanocomposite Film
Authors: Li Peipei , Li Ying , Li Dafei , Liu Songqin
Published: August 2011

A novel nanocomposite integrating the good biocompatibility of polyacrylic resin nanoparticles (PAR) and the good conductivity of colloidal gold nanoparticles was proposed to construct the matrix for the immobilization of hemoglobin (Hb) on the surface of a glassy carbon electrode (GCE). UV‐vis spectra demonstrated that Hb preserved its native structure after being entrapped into the composite film. The direct electrochemistry of hemoglobin (Hb) in this nanocomposite films showed a pair of well‐defined and quasi‐reversible cyclic voltammetric peaks with a formal potential of −0.307 mV and a constant electron transfer rate of 2.51±0.2 s−1. The resultant amperometric biosensor showed fast responses to the analytes with excellent detection limits of 0.2 µM for H2O2 and 0.89 µM for TCA (S/N=3), and high sensitivity of 1108.6 for H2O2 and 77.14 mA cm−2 M−1 for TCA, respectively. The linear current response was found in the range from 0.59 to 7.3 µM (R2=0.9996) for H2O2 and from 5 to 85 µM (R2=0.9996) for TCA, while the superior apparent Michaelis–Menten constant was 0.012 mM for H2O2 and 0.536 mM for TCA, respectively. Therefore, the PAR‐Au‐Hb nanocomposite as a novel matrix opens up a possibility for further study on the direct electrochemistry of other proteins.
A high‐throughput dielectrophoresis‐based cell electrofusion microfluidic device
Authors: Hu Ning , Yang Jun , Yin Zheng‐Qin , Ai Ye , Qian Shizhi , Svir Irina B. , Xia Bin , Yan Jia‐Wen , Hou Wen‐Sheng , Zheng Xiao‐Lin
Published: August 2011

A high‐throughput cell electrofusion microfluidic chip has been designed, fabricated on a silicon‐on‐insulator wafer and tested for in vitro cell fusion under a low applied voltage. The developed chip consists of six individual straight microchannels with a 40‐μm thickness conductive highly doped Si layer as the microchannel wall. In each microchannel, there are 75 pairs of counter protruding microelectrodes, between which the cell electrofusion is performed. The entire highly doped Si layer is covered by a 2‐μm thickness aluminum film to maintain a consistent electric field between different protruding microelectrode pairs. A 150‐nm thickness SiO2 film is subsequently deposited on the top face of each protruding microelectrode for better biocompatibility. Owing to the short distance between two counter protruding microelectrodes, a high electric field can be generated for cell electrofusion with a low voltage imposed across the electrodes. Both mammalian cells and plant protoplasts were used to test the cell electrofusion. About 42–68% cells were aligned to form cell–cell pairs by the dielectrophoretic force. After cell alignment, cell pairs were fused to form hybrid cells under the control of cell electroporation and electrofusion signals. The averaged fusion efficiency in the paired cells is above 40% (the highest was about 60%), which is much higher than the traditional polyethylene glycol method (<5%) and traditional electrofusion methods (∼12%). An individual cell electrofusion process could be completed within 10 min, indicating a capability of high throughput.
Insulator‐based dielectrophoresis of microorganisms: Theoretical and experimental results
Authors: Moncada‐Hernandez Hector , Baylon‐Cardiel Javier L. , Pérez‐González Victor H. , Lapizco‐Encinas Blanca H.
Published: August 2011

Dielectrophoresis (DEP) is the motion of particles due to polarization effects in nonuniform electric fields. DEP has great potential for handling cells and is a non‐destructive phenomenon. It has been utilized for different cell analysis, from viability assessments to concentration enrichment and separation. Insulator‐based DEP (iDEP) provides an attractive alternative to conventional electrode‐based systems; in iDEP, insulating structures are used to generate nonuniform electric fields, resulting in simpler and more robust devices. Despite the rapid development of iDEP microdevices for applications with cells, the fundamentals behind the dielectrophoretic behavior of cells has not been fully elucidated. Understanding the theory behind iDEP is necessary to continue the progress in this field. This work presents the manipulation and separation of bacterial and yeast cells with iDEP. A computational model in COMSOL Multiphysics was employed to predict the effect of direct current‐iDEP on cells suspended in a microchannel containing an array of insulating structures. The model allowed predicting particle behavior, pathlines and the regions where dielectrophoretic immobilization should occur. Experimental work was performed at the same operating conditions employed with the model and results were compared, obtaining good agreement. This is the first report on the mathematical modeling of the dielectrophoretic response of yeast and bacterial cells in a DC‐iDEP microdevice.
Adipogenesis and insulin sensitivity in obesity are regulated by retinoid‐related orphan receptor gamma
Authors: Meissburger Bettina , Ukropec Jozef , Roeder Eva , Beaton Nigel , Geiger Matthias , Teupser Daniel , Civan Burcak , Langhans Wolfgang , Nawroth Peter P. , Gasperikova Daniela , Rudofsky Gottfried , Wolfrum Christian
Published: August 2011

Obesity is a well‐known risk factor for the development of secondary complications such as type 2 diabetes. However, only a part of the obese population develops secondary metabolic disorders. Here, we identify the transcription factor retinoid‐related orphan receptor gamma (RORγ) as a negative regulator of adipocyte differentiation through expression of its newly identified target gene matrix metalloproteinase 3. In vivo differentiation of adipocyte progenitor cells from Rorγ‐deficient mice is enhanced and obese Rorγ−/− mice show decreased adipocyte sizes. These small adipocytes are highly insulin sensitive, leading to an improved control of circulating free fatty acids. Ultimately, Rorγ−/− mice are protected from hyperglycemia and insulin resistance in the state of obesity. In adipose stromal‐vascular fraction from obese human subjects, Rorγ expression is correlated with adipocyte size and negatively correlated with adipogenesis and insulin sensitivity. Taken together, our findings identify RORγ as a factor, which controls adipogenesis as well as adipocyte size and modulates insulin sensitivity in obesity. RORγ might therefore serve as a novel pharmaceutical target to treat obesity‐associated insulin resistance.
Clustering compositional data trajectories: the case of particulate matter in the lower troposphere
Authors: Bruno Francesca , Cocchi Daniela , Greco Fedele
Published: August 2011

Trajectories of compositional data, that is, sequences of composition measurements taken along a domain, can be considered as functional data. The present work centres on a way of clustering compositional data trajectories. Functional cluster analysis has been applied in several fields, but has not been extended to cope with the problem of clustering compositional data trajectories. In this work, we extend functional cluster analysis techniques to the analysis of compositional data using suitable compositional algebra both for smoothing observed trajectories and for building suitable metrics to evaluate dissimilarities between objects. When the focus is on the identification of typical shapes, clustering based on derivatives is the most suitable tool. As a motivating example, we consider clustering particulate matter vertical profiles in the lower troposphere. The impact of the choice of metric on the clustering structure is thoroughly discussed in this case study. Copyright © 2011 John Wiley & Sons, Ltd.
Power conversion systems for modern ac–dc power systems
Authors: Badrzadeh Babak
Published: August 2011

This paper discusses the present and future power conversion systems for high voltage direct current transmission systems. It begins with an introduction into the commercially available semiconductor switching devices and future wide bandgap devices specifically silicon carbide devices. Different High Voltage Direct Current (HVDC) system configurations including the point‐to‐point, back‐to‐back, multi‐terminal, and hybrid ac and dc are discussed. Different configurations of the current source and voltage source converters are presented, and the concept of redundancy and availability for the current source and voltage source schemes is elaborated on. The most significant trends in dc power systems including the transformerless HVDC, ultra high voltage dc transmission, ac to dc replacement, tripole HVDC, dc grids, dc circuit breakers, and dc transformers are presented. Copyright © 2011 John Wiley & Sons, Ltd.
Detection of circulating Bmi‐1 mRNA in plasma and its potential diagnostic and prognostic value for uterine cervical cancer
Authors: Zhang Xin , Wang Chuanxin , Wang Lili , Du Lutao , Wang Shun , Zheng Guixi , Li Wei , Zhuang Xuewei , Zhang Xuhua , Dong Zhaogang
Published: August 2011

Bmi‐1 is overexpressed in uterine cervical cancer (UCC) and is found to be associated with adverse clinical characteristics and poor prognosis. However, little information is available on the status of circulating Bmi‐1 mRNA in UCC. Because circulating cell‐free nucleic acids have emerged as a novel class of markers for cancer detection, our research aims to address this question by detecting the circulating Bmi‐1 mRNA and to assess its diagnostic and prognostic potential in UCC. Reverse transcription quantitative real‐time PCR method was established to detect the circulating Bmi‐1 mRNA in plasma of 109 patients with UCC, 138 patients with cervical intraepithelial neoplasia (CIN) and 80 healthy volunteers, and found that it was significantly increased in UCC compared with CINs and healthy controls (all at p < 0.001). Moreover, its high level was significantly correlated with advanced clinical stage (p < 0.001) and positive lymph nodes metastasis (p = 0.002). The area under the receiver operating characteristic curve (AUC) was 0.881, and the optimal cut‐off value was 0.057, providing a sensitivity of 69.7% and a specificity of 95.9%. The AUC for circulating Bmi‐1 mRNA showed higher diagnosis capability than that for SCC‐Ag (p = 0.035) or CA125 (p < 0.001) currently utilized. Kaplan–Meier analysis demonstrated a correlation between increased circulating Bmi‐1 mRNA level and reduced disease‐free survival (DFS) (p = 0.001) and overall survival (OS) (p = 0.015). And, Cox analysis indicated that it was an independent prognostic factor for DFS and OS. We conclude that circulating Bmi‐1 mRNA may be a potential noninvasive molecular marker for diagnosis and prognosis of UCC.
Meta‐analysis of gene expression profiles associated with histological classification and survival in 829 ovarian cancer samples
Authors: Fekete Tibor , Rásó Erzsébet , Pete Imre , Tegze Bálint , Liko István , Munkácsy Gyöngyi , Sipos Norbert , Rigó János , Györffy Balázs
Published: August 2011

Transcriptomic analysis of global gene expression in ovarian carcinoma can identify dysregulated genes capable to serve as molecular markers for histology subtypes and survival. The aim of our study was to validate previous candidate signatures in an independent setting and to identify single genes capable to serve as biomarkers for ovarian cancer progression. As several datasets are available in the GEO today, we were able to perform a true meta‐analysis. First, 829 samples (11 datasets) were downloaded, and the predictive power of 16 previously published gene sets was assessed. Of these, eight were capable to discriminate histology subtypes, and none was capable to predict survival. To overcome the differences in previous studies, we used the 829 samples to identify new predictors. Then, we collected 64 ovarian cancer samples (median relapse‐free survival 24.5 months) and performed TaqMan Real Time Polimerase Chain Reaction (RT‐PCR) analysis for the best 40 genes associated with histology subtypes and survival. Over 90% of subtype‐associated genes were confirmed. Overall survival was effectively predicted by hormone receptors (PGR and ESR2) and by TSPAN8. Relapse‐free survival was predicted by MAPT and SNCG. In summary, we successfully validated several gene sets in a meta‐analysis in large datasets of ovarian samples. Additionally, several individual genes identified were validated in a clinical cohort.
Inhibition of autophagy potentiates the antitumor effect of the multikinase inhibitor sorafenib in hepatocellular carcinoma
Authors: Shimizu Satoshi , Takehara Tetsuo , Hikita Hayato , Kodama Takahiro , Tsunematsu Hinako , Miyagi Takuya , Hosui Atsushi , Ishida Hisashi , Tatsumi Tomohide , Kanto Tatsuya , Hiramatsu Naoki , Fujita Naonobu , Yoshimori Tamotsu , Hayashi Norio
Published: August 2011

Multikinase inhibitor sorafenib inhibits proliferation and angiogenesis of tumors by suppressing the Raf/MEK/ERK signaling pathway and VEGF receptor tyrosine kinase. It significantly prolongs median survival of patients with advanced hepatocellular carcinoma (HCC) but the response is disease‐stabilizing and cytostatic rather than one of tumor regression. To examine the mechanisms underlying the relative resistance in HCC, we investigated the role of autophagy, an evolutionarily conserved self‐digestion pathway, in hepatoma cells in vitro and in vivo. Sorafenib treatment led to accumulation of autophagosomes as evidenced by conversion from LC3‐I to LC3‐II observed by immunoblot in Huh7, HLF and PLC/PRF/5 cells. This induction was due to activation of autophagic flux, as there was further increase in LC3‐II expression upon treatment with lysosomal inhibitors, clear decline of the autophagy substrate p62, and an mRFP‐GFP‐LC3 fluorescence change in sorafenib‐treated hepatoma cells. Sorafenib inhibited the mammalian target of rapamycin complex 1 and its inhibition led to accumulation of LC3‐II. Pharmacological inhibition of autophagic flux by chloroquine increased apoptosis and decreased cell viability in hepatoma cells. siRNA‐mediated knockdown of the ATG7 gene also sensitized hepatoma cells to sorafenib. Finally, sorafenib induced autophagy in Huh7 xenograft tumors in nude mice and coadministration with chloroquine significantly suppressed tumor growth compared with sorafenib alone. In conclusion, sorafenib administration induced autophagosome formation and enhanced autophagic activity, which conferred a survival advantage to hepatoma cells. Concomitant inhibition of autophagy may be an attractive strategy for unlocking the antitumor potential of sorafenib in HCC.
HLA‐G expression is associated with metastasis and poor survival in the Balb/c nu/nu murine tumor model with ovarian cancer
Authors: Lin Aifen , Zhang Xia , Xu Hui‐Hui , Xu Dan‐Ping , Ruan Yan‐Yun , Yan Wei‐Hua
Published: August 2011

Aberrant HLA‐G expression is associated with tumor invasiveness and poor clinical prognosis; however, there is a lack of preclinical animal model to address whether HLA‐G plays a causal role in the unfavorable prognosis of malignancies. In the current study, ovarian carcinoma cell lines (HO‐8910 and Ovcar‐3) were transfected with HLA‐G gene. HLA‐G expression was analyzed with western blot and flow cytometry. Transwell experiment was performed to analyze the cell migration and invasion capability and/or multicellular spheroid formation was investigated with the 3D culture assay in vitro. The effects of HLA‐G expression for tumor cell organ metastasis and for mouse survival was analyzed with the Balb/c nu/nu mouse model. Our data showed that HO‐8910‐G and Ovcar‐3‐G cells are of higher invasion potential compared with the parental HO‐8910 and Ovcar‐3 cells. Multicellular spheroid formation exists only in HO‐8910‐G cells in a 3D culture assay. In Balb/c nu/nu mouse model, widespread metastasis was observed in mice xenografted with HO‐8910‐G cells, but not in the group with parental cells. Mouse survival was dramatically decreased in HO‐8910‐G and Ovcar‐3‐G xenografted mice than that with HO‐8910 and Ovcar‐3 cells, respectively. In summary, our study provided the first evidence that HLA‐G expression is associated with tumor metastasis and with poor survival in an animal model with ovarian cancer.
ALCAM (CD166) expression and serum levels are markers for poor survival of esophageal cancer patients
Authors: Tachezy Michael , Effenberger Katharina , Zander Hilke , Minner Sarah , Gebauer Florian , Vashist Yogesh K. , Sauter Guido , Pantel Klaus , Izbicki Jakob R. , Bockhorn Maximilian
Published: August 2011

The expression of the activated leukocyte cell adhesion molecule (ALCAM and CD166) is increased in various types of cancer. We aimed to evaluate its role as a prognostic marker for esophageal cancer (EC). We retrospectively analyzed ALCAM expression in 299 primary lesions, 147 lymph node and 46 distant metastases from EC patients, on a tissue microarray using immunohistochemistry. Bone marrow samples from representative cancer patients (n = 16), taken before primary surgery, were stained by double‐immunofluorescence for ALCAM and cytokeratins (CK). Blood serum samples from 236 cancer patients and 127 controls were analyzed for serum ALCAM (s‐ALCAM) by ELISA. The immunohistochemical analysis showed increased ALCAM expression in the majority of lesions (primary tumor 71%, lymph node 76% and distant metastases 80%). ALCAM expression was not associated with histopathological parameters except for tumor grading (p = 0.015). ALCAM‐positive patients had significantly worse recurrence‐free and overall survival (OS; p = 0.002). Disseminated tumor cells (DTC) in bone marrow showed two phenotypes, ALCAM+/CK+ (36%) and ALCAM‐/CK+ (64%). Multivariate analysis revealed that ALCAM expression and elevated s‐ALCAM serum values are powerful prognostic variables for OS in patients with EC (hazard ratio [HR] 3.987, 95% confidence interval [95%CI] 1.906–8.340, p < 0.001 and HR 1.915, 95%CI 1.021–3.592, p = 0.043). The results of our study provide preliminary evidence for the potential clinical utility of ALCAM as a prognostic biomarker for EC, which might be a basis for future clinical application. In addition, ALCAM expression in a subset of DTC of the bone marrow indicates a potential function in the metastatic cascade of EC.
BENCHMARK IRRIGATION PRACTICES ON OLIVES USING A STRUCTURAL EQUATION MODELLING APPROACH
Authors: Correia L. , El‐Ahmadi A. , Molle B. , Maia R. , Oliveira I.
Published: August 2011

Olive production is currently increasing in Portugal, particularly in the Guadiana river basin. In Serpa and Moura, a traditional region of dry farming olive plantations now comprise up to 50% of the total irrigated area. The present paper reports some of the results of a benchmarking study conducted in the framework of the AquaStress Integrated Project in the Guadiana Case Study (GCS). The aim of the work was to produce references to anticipate water requirements when the future Ardila Irrigation System, which is connected to the Alqueva dam, opens in 2010. This system is intended to supply water to some 30 000 ha of newly irrigated land in the region. During the study, public participation workshops were held to understand the specific needs and points of view of farmers and other stakeholders. The benchmarking analysis was based on continuous monitoring of 28 olive farms and collection of information on practices and production options available in 2007.

An originality of this work is the use of a structural equation modelling (SEM) procedure to identify the effects of farmers’ agricultural and irrigation practices on production and quality parameters. SEM is a statistical technique for testing and estimating causal relationships using a combination of statistical data and qualitative causal assumptions. It allows both confirmatory and exploratory modelling, meaning it is suited to both theory testing and development. The benchmarking process was based on participatory workshops that helped farmers understand how to improve their own irrigation and agricultural practices based on the experience of the rest of the group.

Our approach was based on a heterogeneous set of plots, and results indicated that certain technical irrigation parameters, namely the number and discharge of drippers per tree, might have a greater influence on final production than total water applied. Such an approach could also be applied to data collected on a regular basis by extension services to identify on long term the influence of production management and practices on productivity. Copyright © 2011 John Wiley & Sons, Ltd.
Membrane extraction of a new antibiotic (Shengjimycin): equilibrium and mass transfer analysis
Authors: Hossain Md M , Rothman Kam , Jiang Wei , Sun Chenghang
Published: August 2011

BACKGROUND: During the last two decades, separations based on liquid membrane technology have been demonstrated to be a potentially attractive process for a large number of industrial separations. The advantages of this technology over the current separation processes allowed its commercialization in the area of chemical/environmental applications (for the removal of toxic metals). Efforts are being devoted to biotechnological processes where membrane extraction has an added advantage of improving the productivity by removing inhibitory product during its production cycle. In this article the applicability of a membrane extraction technique based on hollow‐fibre membrane modules is investigated to extract a new antibiotic, Shengjimycin (SJM). SJM is produced in a multicomponent fermentation broth, from which the main components required to be separated selectively.

RESULTS: From equilibrium experiments, sunflower oil, a cheap and less toxic solvent, was found to be good for the extraction of SJM at its natural pH of 7.2–7.8. Addition of a small amount (1.5%) of Amberlite LA‐2 (a carrier) in the solvent could intensify the process to achieve a high distribution coefficient. The process using this organic phase (Amberlite LA‐2 in sunflower oil) gave good extraction (ca 70%) within 3–4 h in a pilot‐scale hollow‐fibre membrane module. This new system is preferred over the toxic solvents being used or tried because of its cost, less toxicity, low environmental impact and operator‐friendliness.

CONCLUSIONS: Because of the above‐mentioned favourable characteristics this membrane extraction method has the potential to be sustainable and effective as it has shown selective separation of the desired component from a multicomponent mixture. Copyright © 2011 Society of Chemical Industry
Design of carbon nanotube fiber microelectrode for glucose biosensing
Authors: Zhu Zhigang , Garcia‐Gancedo Luis , Flewitt Andrew J. , Moussy Francis , Li Yali , Milne William I.
Published: August 2011

BACKGROUND: Carbon nanotube (CNT) fiber directly spun from an aerogel has a unique, well‐aligned nanostructure (nano‐pore and nano‐brush), and thus provides high electro‐catalytic activity and strong interaction with glucose oxidase enzyme. It shows great potential as a microelectrode for electrochemical biosensors.

RESULTS: Cyclic voltammogram results indicate that post‐synthesis treatments have great influence on the electrocatalytic activity of CNT fibers. Raman spectroscopy and electrical conductivity tests suggest that fibers annealed at 250 °C remove most of the impurities without damaging the graphite‐like structure. This leads to a nano‐porous morphology on the surface and the highest conductivity value (1.1 × 105 S m−1). Two CNT fiber microelectrode designs were applied to enhance their electron transfer behaviour, and it was found that a design using a 30 nm gold coating is able to linearly cover human physiological glucose level between 2 and 30 mmol L−1. The design also leads to a low detection limit of 25 µmol L−1.

CONCLUSIONS: The high performance of CNT fibers not only offers exceptional mechanical and electrical properties, but also provides a large surface area and electron transfer pathway. They consequently make excellent bioactive microelectrodes for glucose biosensing, especially for potential use in implantable devices. Copyright © 2011 Society of Chemical Industry