bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of isocyanates by capillary electrophoresis with tris(2,2′‐bipyridine)ruthenium(II) electrochemiluminescence
Authors: Li Haijuan , Shi Lihong , Liu Xiaoqing , Niu Wenxin , Xu Guobao
Published: November 2009

CE with tris(2,2′‐bipyridyl) ruthenium(II) (Ru(bpy)32+) electrochemiluminescence (ECL) detection for the quantitative determination of isocyanates was first reported. Hexamethylene diisocyanate (HDI) and hexyl isocyanate (HI) were used as the model analytes. Commercially available N,N‐diethyl‐N′‐methylethylenediamine was used as the derivatization reagent. It has both a secondary amine group and a tertiary amine group. The secondary amine group can quantitatively react with isocyanate group, and the tertiary amine group can react with Ru(bpy)32+ to produce strong ECL signal for sensitive detection. The derivatization reaction was almost instantaneous and is much faster than other reported derivative reactions using other derivative reagents. The urea formed was stable. Linear calibration curve was obtained in the range from 0.01 to 10 μM for HDI, and 0.02 to 20 μM for hexyl isocyanate (HI). The detection limit is 0.01 μM for HDI and 0.02 μM for HI. The method is more sensitive than UV‐detection and electrochemical detection. For practical application, recovery higher than 90% for HDI and HI was obtained for foam sample.
Monolithic silica capillary columns with immobilized cellulose tris(3,5‐dimethylphenylcarbamate) for enantiomer separations in CEC
Authors: He Chiyang , Hendrickx Ans , Mangelings Debby , Smeyers‐Verbeke Johanna , Vander Heyden Yvan
Published: November 2009

Two types of monolithic silica capillary columns with an immobilized cellulose tris(3,5‐dimethylphenylcarbamate) (CDMPC) selector were prepared for enantiomer separations in CEC. The monolithic columns were prepared by a sol‐gel process in fused‐silica capillaries. CDMPC was then either immobilized on a silica monolith through an intermolecular polycondensation of the cellulose derivative containing a triethoxysilyl group, or on a vinylized silica monolith through radical copolymerization of the cellulose derivative, which also contained a vinyl group. IR spectra confirmed the successful immobilization of CDMPC on both columns. Eleven chiral compounds were used to evaluate the enantioselectivity on both column types. Results indicated that the columns obtained via polycondensation had higher separation ability than those obtained via radical polymerization, and that they showed satisfactory run‐to‐run repeatability and stability. These new techniques thus provide strategies for preparing immobilized polysaccharide‐based chiral silica monolithic capillary columns for chiral separations by means of CEC.
A new approach for the computation of harmonics and interharmonics produced by AC/DC/AC conversion systems with PWM inverters
Authors: Langella Roberto , Sollazzo Adolfo , Testa Alfredo
Published: November 2009

The computation of harmonics and interharmonics produced by AC/DC/AC conversion systems with PWM inverters is considered, and a new approach is presented. Basically, a new inverter model is introduced that is based on the modulation function theory and is able to take into account the voltage ripple at the inverter input terminals. A rectifier model that was previously proposed and the new inverter model are first used in the framework of a direct injection procedure and, then, in an iterative harmonic and interharmonic analysis. The proposed model can be applied successfully to adjustable speed drives for asynchronous motors, achieving better modeling accuracy with respect to approaches based on simplified inverter modeling. They also allow a sensible reduction of computational burden with respect to the time‐domain models. For this reason, they constitute an attractive tool inside Monte Carlo simulations for probabilistic analyses of harmonic and interharmonic distortion. Numerical experiments demonstrate the good performance of the proposed models and the need to account for the presence of interharmonics for high‐power PWM drives. Copyright © 2009 John Wiley & Sons, Ltd.
Predictors of complications in therapeutic plasma exchange
Authors: Bramlage Carsten P. , Schröder Katharina , Bramlage Peter , Ahrens Katharina , Zapf Antonia , Müller Gerhard Anton , Koziolek Michael J.
Published: November 2009

Plasma exchange (PE) is used for blood purification to modulate proteins involved in pathological processes. As the number of patients receiving PE treatment and the heterogeneity of the underlying diseases is steadily increasing, we evaluated the most frequent complications and analyzed causes leading to adverse reactions. 883 PE procedures in 113 patients between the years 2000 to 2006 were retrospectively analyzed with respect to complications. Additionally, underlying diseases and settings of PE procedure were analyzed to identify high‐risk patients and respective PE settings. A total of 226 adverse reactions were recorded (25.6% of all PE procedures). Most complications were mild (n = 121, 13.7%) or moderate (n = 98, 11.0%). In seven cases (n = 7, 0.7%), severe, life‐threatening adverse events were induced by PE either due to severe allergic reactions (n = 4, 0.5%) or to sepsis (n = 3, 0.3%). Patients with neurologic diseases had a significantly higher risk to develop complications compared to those with internal diseases (P = 0.013). This was due to a higher rate of PE associated adverse events (in particular hypotension) and complications associated with vascular access. Among patients from internal medicine those with hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP) had the highest risk to develop complications. Patients with neurological diseases compared to those with medical conditions and patients with HUS/TTP compared to those with other diseases had a higher risk to develop complications. However, severe adverse events are rare. Thus, PE seems to be a safe and recommendable procedure. J. Clin. Apheresis, 2009. © 2009 Wiley‐Liss, Inc.
Is antiquitin a mitochondrial Enzyme?
Authors: Wong Judy Wei‐Yan , Chan Chi‐Lung , Tang Wai‐Kwan , Cheng Christopher Hon‐Ki , Fong Wing‐Ping
Published: November 2009

Antiquitin is an aldehyde dehydrogenase involved in the catabolism of lysine. Mutations of antiquitin have been linked with the disease pyridoxine‐dependent seizures. While it is well established that lysine metabolism takes place in the mitochondrial matrix, evidence for the mitochondrial localization of antiquitin has been lacking. In the present study, the subcellular localization of antiquitin was investigated using human embryonic kidney HEK293 cells. Three different approaches were used. First, confocal microscopic analysis was carried out on cells transiently transfected with fusion constructs containing enhanced green fluorescent protein with different lengths of antiquitin based on the different potential start codons of translation. Second, immunofluorescence staining was used to detect the localization of antiquitin directly in the cells. Third, subcellular fractionation was carried out and the individual fraction was analyzed for the presence of antiquitin by Western blot and flow cytometric analyses. All the results showed that antiquitin was present not only in the cytosol but also in the mitochondria. J. Cell. Biochem. 109: 74–81, 2010. © 2009 Wiley‐Liss, Inc.
Mechanistic and kinetic investigations of N2H4+ OH reaction
Authors: Tang Yizhen , Sun Jingyu , Jia Xiujuan , Sun Hao , Pan Xiumei , Wang Rongshun
Published: November 2009

The reaction of N2H4with OH has been investigated by quantum chemical methods. The results show that hydrogen abstraction mechanism is more feasible than substitution mechanism thermodynamically. The calculated rate constants agree with the available experimental data. The calculated results show that the variational effect is small at lower temperature region, while it becomes significant at higher temperature region. On the other hand, the small‐curvature tunneling effect may play an important role in the temperature range 220−3000 K. Moreover, the calculated rate constants show negative temperature dependence at the temperatures below 500 K, which is in accordance with Vaghjiani's report that slightly negative temperature dependence is found over the temperature range of 258−637 K. The mechanism of the major product (N2H3) with OH has also been investigated theoretically to understand the title reaction thoroughly. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Pyrolytic lignin removal for the valorization of biomass pyrolysis crude bio‐oil by catalytic transformation
Authors: Gayubo A. G. , Valle B. , Aguayo A. T. , Olazar M. , Bilbao J.
Published: November 2009

BACKGROUND: The catalytic processes for valorizing the bio‐oil obtained from lignocellulosic biomass pyrolysis face the problem that a great amount of carbonaceous material is deposited on the catalyst due to the polymerization of phenol‐derived compounds in the crude bio‐oil. This carbonaceous material blocks the catalytic bed and contributes to rapid catalyst deactivation. This paper studies an on‐line two‐step process, in which the first one separates the polymerizable material and produces a reproducible material whose valorization is of commercial interest.

RESULTS: The establishment of a step for pyrolytic lignin deposition at 400 °C avoids the blockage of the on‐line catalytic bed and attenuates the deactivation of a HZSM‐5 zeolite based catalyst used for hydrocarbon production. The origin of catalyst deactivation is coke deposition, which has two fractions (thermal and catalytic), whose content is attenuated by prior pyrolytic lignin separation and by co‐feeding methanol. The morphology and properties of the material deposited in the first step (pyrolytic lignin) are similar to lignins obtained as a by‐product in wood pulp manufacturing.

CONCLUSIONS: The proposed reaction strategy, with two steps (thermal and catalytic) in series, valorizes the crude bio‐oil by solving the problems caused by the polymerization of phenolic compounds, which are obtained in the pyrolysis of the lignin contained in lignocellulosic biomass. Given that a by‐product (pyrolytic lignin) is obtained with similar properties to the lignin from wood pulping manufacturing, the perspectives for the viability of lignocellulosic biomass valorization are promising, which is essential for furthering its implementation in biorefinery processes. Copyright © 2009 Society of Chemical Industry
Kinetic study of the manganese‐based catalytic hydrogen peroxide oxidation of a persistent azo‐dye
Authors: Tizaoui Chedly , Karodia Nazira , Aburowais Mohsen
Published: November 2009

BACKGROUND: The discharge of synthetic dyes by the textile industry into the environment poses concerns due to their persistence and toxicity. New efficient treatment processes are required to effectively degrade these dyes. The aim of this work was to study the degradation of a persistent dye (Drimarene Brilliant Reactive Red K‐4BL, C.I.147) using H2O2 oxidation catalysed by an Mn(III)‐saltren catalyst and to develop a kinetic model for this system.

RESULTS: Dye oxidation with H2O2 was significantly improved by the addition of the catalyst. As the pH was increased from 3 to 10, the oxidation rates increased significantly. The kinetic model developed in this study was found to adequately explain the experimental results. In particular, dye oxidation can be described at high pH by pseudo‐first‐order kinetics. A Michaelis–Menton type equation was developed from the model and was found to adequately describe the effect of H2O2 and catalyst concentrations on the apparent pseudo‐first‐order rate constant. Optimum catalyst and H2O2 concentrations of 500 mg L−1 and 6.3 g L−1, respectively, were found to give maximum reaction rates.

CONCLUSION: Catalytic H2O2 oxidation was found to be effective for the removal of persistent dye and the results obtained in this work are of significance for design and scale‐up of a treatment process. Copyright © 2009 Society of Chemical Industry
Transplantation of human mesenchymal stem cells promotes functional improvement and increased expression of neurotrophic factors in a rat focal cerebral ischemia model
Authors: Wakabayashi Kiryo , Nagai Atsushi , Sheikh Abdullah Md. , Shiota Yuri , Narantuya Dashdemberel , Watanabe Tatsuzo , Masuda Junichi , Kobayashi Shotai , Kim Seung U. , Yamaguchi Shuhei
Published: November 2009

Previous studies have suggested that intravenous transplantation of mesenchymal stem cells (MSCs) in rat ischemia models reduces ischemia‐induced brain damage. Here, we analyzed the expression of neurotrophic factors in transplanted human MSCs and host brain tissue in rat middle cerebral artery occlusion (MCAO) ischemia model. At 1 day after transient MCAO, 3 × 106 immortalized human MSC line (B10) cells or PBS was intravenously transplanted. Behavioral tests, infarction volume, and B10 cell migration were investigated at 1, 3, 7, and 14 days after MCAO. The expression of endogenous (rat origin) and exogenous (human origin) neurotorphic factors and cytokines was evaluated by quantitative real‐time RT‐PCR and Western blot analysis. Compared with PBS controls, rats receiving MSC transplantation showed improved functional recovery and reduced brain infarction volume at 7 and 14 days after MCAO. In MSC‐transplanted brain, among many neurotrofic factors, only human insulin‐like growth factor 1 (IGF‐1) was detected in the core and ischemic border zone at 3 days after MCAO, whereas host cells expressed markedly higher neurotrophic factors (rat origin) than control rats, especially vascular endothelial growth factor (VEGF) at 3 days and epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) at 7 days after MCAO. Intravenously transplanted human MSCs induced functional improvement, reduced infarct volume, and neuroprotection in ischemic rats, possibly by providing IGF‐1 and inducing VEGF, EGF, and bFGF neurotrophic factors in host brain. © 2009 Wiley‐Liss, Inc.
Engineering scaffold‐free bone tissue using bone marrow stromal cell sheets
Authors: Ma Dongyang , Ren Liling , Liu Yanpu , Chen Fulin , Zhang Junrui , Xue Zhenxun , Mao Tianqiu
Published: November 2009

The use of exogenous scaffolds to engineer bone tissue faces several drawbacks including insufficient biological activity, potential immunogenicity, elevated inflammatory reaction, fluctuating degradation rate, and low cell‐attachment efficiency. To circumvent these limitations, we sought to engineer large scaffold‐free bone tissue using cell sheets. We harvested intact cell sheets from bone marrow stromal cells using a continuous culture method and a scraping technique. The cell sheets were then rolled and fabricated into large constructs. Finally, the constructs were implanted into the subcutaneous pockets of nude mice. The cells within the sheet maintained in vitro osteogenic potential after osteoblast differentiation. Computed tomography scans and histological examination confirmed new bone formation in vivo. Additionally, the engineered bone exhibited enhanced compressive strength. Our results indicate that the BMSC sheets can facilitate the formation of functional three‐dimensional bone tissue without the use of exogenous scaffolds. Hence, the study provides an intriguing alternative strategy for bone repair. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:697–702, 2010
Microcomputed tomography assessment of glenoid component cementation techniques in total shoulder arthroplasty
Authors: Hasan Syed Ashfaq , Cox Wesley K. , Syed Muhammad , Suva Larry J.
Published: November 2009

Various strategies have been described to improve glenoid component cementation technique in shoulder arthroplasty, such as the “weephole” technique (WH), which is thought to allow for improved cement mantles by suction venting the glenoid vault through the coracoid. The purpose of this study was to compare the cement mantle created using standard syringe pressurization (SP) to WH or a new, modified weephole technique (MWH), not requiring specific instrumentation of the coracoid medullary canal. Fourteen cadaveric scapulae underwent preparation of the glenoid to allow for implantation of glenoid components. Component fixation was achieved using SP, WH, or MWH. The volumes of cement surrounding each individual peg on the component, of the cement mantle between the back of the glenoid, and of the reamed glenoid face were quantified using micro‐CT. Compared to SP, significantly larger cement mantles were observed around all pegs with both the WH (p = 0.023) and MWH (p = 0.007). Similarly, both the WH and MWH techniques demonstrated significantly decreased cement behind the glenoid component (p = 0.003) compared to SP, with no significant difference between the WH and the MWH techniques. Both WH and MWH techniques increase cement mantle volume around individual pegs and decrease the amount of glenoid face cement compared to conventional SP. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:559–564, 2010
Textural, nutritional and functional attributes in tomato genotypes for breeding better quality varieties
Authors: Saha Supradip , Hedau Nirmal K , Mahajan Vinay , Singh Gyanendra , Gupta Hari S , Gahalain Anita
Published: November 2009

BACKGROUND: Screening of natural biodiversity for their better quality attributes is of prime importance for quality breeding programmes. A set of 53 tomato genotypes was measured for their textural [skin firmness, pericarp thickness, total soluble solids (TSS)], nutritional [phosphorus (P), potassium (K), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn) and titrable acidity (TA)] and functional (β‐carotene, lycopene and ascorbic acid) quality attributes.

RESULT: Three sets of data (textural, nutritional and functional attributes) were obtained and analysed for their mutual relationships. Wide variations were observed in most of the measurements, e.g. skin firmness (coefficient of variability (CV) 269‐612 g), pericarp thickness (CV 1.4–4.9 mm), potassium (CV 229–371 mg 100 g−1), iron (CV 611–1772 mg 100 g−1), ascorbic acid (CV 12–86 mg 100 g−1), suggesting that there are considerable levels of genetic diversity. Significant correlations (P < 0.05, 0.01) were also detected among different attributes of tomato genotypes, such as phosphorus and zinc with a correlation coefficient of 0.74, ascorbic acid and copper of 0.57, pericarp thickness and lycopene of − 0.52. However, there were no correlations between textural and nutritional attributes. Five factors were computed by principal component analysis that explained 66% of the variation in the attributes, among which all micronutrients other than iron, TSS, firmness and β‐carotene were most important. Functional attributes except β‐carotene played a less important role in explaining total variation.

CONCLUSION: This knowledge could aid in the efficient conservation of important parts of the agricultural biodiversity of India. These results are also potentially useful for tomato breeders working on the development of new varieties. Copyright © 2009 Society of Chemical Industry
Comparative in vitro Cytotoxicity Toward Human Osteoprogenitor Cells of Polycaprolactones Synthesized from Various Metallic Initiators
Authors: Schappacher Michèle , Le Hellaye Maude , Bareille Reine , Durrieu Marie‐Christine , Guillaume Sophie M.
Published: November 2009

Various poly(ε‐caprolactone)s (PCLs) prepared by ring‐opening polymerization of ε‐caprolactone (CL) initiated by a range of metallic derivatives such as alkoxides, Al(OiPr)3, La(OiPr)3, Sn(octanoate)2, Ti(OiPr)4, Zn[O(CH2)3NHtBoc]2, or borohydride La(BH4)3(THF)3 were evaluated for their in vitro cytotoxicity. The amount of residual metal present in the polymer samples was measured and compared to the initial quantity introduced. The effect of the metallic system on the biocompatibility profiles of the resulting polyesters was evaluated in vitro on PCL films from a series of cytotoxicity tests involving MTT and neutral red assays upon exposure to human osteoprogenitor cells. The absence of toxic influence of all these PCLs suggests that they may be used as biomaterials in contact with living human cells.

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A Highly Efficient siRNA Carrier of PBLG Modified Hyperbranched PEI
Authors: Chen Jie , Tian Huayu , Guo Zhaopei , Xia Jialiang , Kano Arihiro , Maruyama Atsushi , Jing Xiabin , Chen Xuesi
Published: November 2009

In search for effective non‐viral gene vectors for the delivery of siRNA, a copolymer was designed and synthesized by grafting hydrophobic poly(γ‐benzyl L‐glutamate) segment (PBLG) to hyperbranched polyethylenimine (PEI‐PBLG). PEI‐PBLG could efficiently deliver siRNA to cells to silence the targeted gene. Markedly, PEI‐PBLG caused lower cytotoxicity in comparison to unmodified PEI. The siRNA complexed with PEI‐PBLG showed a remarkable knockdown (75.23% relative to untreated cells, without changing the medium after 6 h of incubation) of the targeted luciferase gene in stable expressing luciferase CT26 cells while the Lipofectamine™2000 and unmodified PEI could only achieve knockdown rates of 57.92% and 15.31%, respectively. The siRNA complexed with PEI‐PBLG also demonstrated that it had greater gene silencing ability than unmodified PEI and Lipofectamin™2000 in both 4T1 cells stably transfected with the luciferase gene and HeLa cells transiently transfected with the luciferase gene. The internalization efficiency of carrier/Alexa647‐labeled siRNA was quantified using flow cytometry. PEI‐PBLG/Alexa647‐labeled siRNA showed internalization efficiency of 52.67% while PEI and Lipofectamine™2000 demonstrated 27.23% and 37.91%, respectively. Confocal laser scanning microscopy (CLSM) assay also indicated that PEI‐PBLG induced higher cell uptake efficiency than other commercial reagents. PEI‐PBLG was shown to be a promising siRNA carrier with potential application in cancer therapy.

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25 years of Psychology & Marketing: a multidimensional review
Authors: Shabbir Haseeb Ahmed , Reast Jon , Palihawadana Dayananda
Published: November 2009

The first issue of Psychology & Marketing was published in 1984. The journal was conceived as a forum for academics and practitioners in psychology, marketing, and related fields to engage in an exchange of scholarly information. The raison d'être of the journal was to bring psychologically sophisticated information and methodologies to bear on all aspects of marketing theory and practice. This review analyzes the performance of Psychology & Marketing from several perspectives, and includes data comparing its performance to the performance of other journals. Looking back over the last 25 years of its history, it seems fair to conclude that Psychology & Marketing has clearly delivered on its tacit promise of effectively building the knowledge base of marketing through psychology‐based insights. Looking forward, it seems reasonable to anticipate that the journal's well‐established track record in terms of diversity in the content, research design, and methodologies of its published articles will continue to stand as a welcome and refreshing distinction from other journals covering comparable domains of study. © 2009 Wiley Periodicals, Inc.
Third‐person perception and purchase behavior in response to various selling methods
Authors: Tal‐Or Nurit , Shilo Shiri , Meister Talia
Published: November 2009

Two studies investigated whether various tactics of personal selling that generate different levels of resistance also produce different degrees of third‐person perceptions. Furthermore, the studies compared third‐person perceptions to the actual influence on behavior. Study 1 showed that more direct and blatant selling methods produce more TPP. Study 2 showed that people tend to underestimate the influence of the more direct method, especially with regard to themselves. The study concludes by identifying the ideal selling method as one in which the customers are asked about their willingness to listen to the sales campaign before they are told about it. This method increases sales and creates satisfied customers. © 2009 Wiley Periodicals, Inc.
Synthesis and Fluorescent Properties of Biodegradable Hyperbranched Poly(amido amine)s
Authors: Yang Wen , Pan Cai‐Yuan
Published: November 2009

Disulfide‐functionalized hyperbranched poly(amido amine)s (HPAMAMs) were synthesized by Michael addition polymerization of N,N'‐cystaminebisacrylamide and 1‐(2‐aminoethyl)piperazine. The novel HPAMAMs displayed bright fluorescence, and the emissions bands cover nearly the whole visible wavelength range. When polymer solutions were excited at 330–385, 460–490, and 510–550 nm, blue, green, and red solutions were observed, respectively. The HPAMAMs are biodegradable and they can be easily cleaved by 2‐mercaptoethanol or glutathione, leading to a decrease in the fluorescence intensity. Studies of applications of the biocompatible and biodegradable HPAMAMs in fluorescence imaging technology and biological science are in progress.

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Dopamine agonist‐induced antecollis in Parkinson's disease
Authors: Uzawa Akiyuki , Mori Masahiro , Kojima Shigeyuki , Mitsuma Satsuki , Sekiguchi Yukari , Kanesaka Toshihide , Kuwabara Satoshi
Published: November 2009

Few cases of dopamine agonist‐induced antecollis in Parkinson's disease (PD) have been reported. Literature review of 16 PD patients including our 3 cases with dopamine agonist‐induced antecollis showed predominance of (1) Japanese, (2) women, and (3) Hoehn‐Yahr stage of ≥3. We experienced three Japanese PD patients who subacutely exhibited antecollis following increased dopamine agonist dose that improved just after withdrawal of the agonist. One patient developed antecollis during increasing pramipexole dose in combination with cabergoline. Antecollis in another patient appeared during increasing pramipexole dose; it worsened after substituting pergolide for pramipexole, but improved after withdrawal of pergolide. Our cases indicate that there is no specific dopamine agonist causing antecollis, and it is possibly caused by a number of single dopamine agonists or a combination of them. Dopamine agonist‐induced antecollis should be considered when encountering antecollis in PD patients being treated with dopamine agonists and withdrawal of the agonist can improve symptoms. © 2009 Movement Disorder Society
Alpha‐synuclein polymorphisms are associated with Parkinson's disease in a Saskatchewan population
Authors: Rajput Alex , Vilariño‐Güell Carles , Rajput Michele L. , Ross Owen A. , Soto‐Ortolaza Alexandra I. , Lincoln Sarah J. , Cobb Stephanie A. , Heckman Michael G. , Farrer Matthew J. , Rajput Ali
Published: November 2009

Alpha‐synuclein gene (SNCA) mutations cause familial Parkinsonism but the role of SNCA variability in idiopathic Parkinson's disease (PD) remains incompletely defined. We report a study of SNCA genetic variation in 452 idiopathic PD cases and 245 controls. SNCA copy number mutations were not associated with early‐onset disease in this population. The minor allele “G” at rs356165 was associated with increased odds of PD (P = 0.013) and genetic variation in D4S3481 (Rep1) was associated with age of disease onset (P = 0.007). There was a trend toward association between variation at rs2583988 and rapid PD progression. © 2009 Movement Disorder Society
Accuracy of Parkinson's disease diagnosis in 610 general practice patients in the West of Scotland
Authors: Newman Edward J. , Breen Kieran , Patterson Jim , Hadley Donald M. , Grosset Katherine A. , Grosset Donald G.
Published: November 2009

UK‐based community studies have found high rates of misdiagnosis in Parkinson's disease (PD). Searches of prescription databases and case records identified 610 patients taking antiparkinson therapy for a PD diagnosis in 92 West of Scotland General Practices. Patients with no documented progression of parkinsonism and/or no increase in antiparkinson medication for 3 years were assessed by two movement disorder specialists. FP‐CIT SPECT scanning was performed in clinically uncertain cases. Those considered unlikely to have PD had antiparkinson drugs tapered then stopped, with a minimum of 6 months follow‐up. Age, sex and disease duration matched controls were also assessed. 64 of 89 (71.9%) patients meeting selection criteria were assessed, of whom 36 (56.3%) were appropriate for therapy withdrawal. Thirty three of those 36 patients (91.7%) and 3 of 64 (4.7%) controls stopped antiparkinson therapy without deterioration giving an overall total of 36 of 610 (5.9%). The revised diagnoses in this group were mainly essential tremor (ET) (n = 14) and vascular parkinsonism (VP) (n = 10). Patients managed in Primary Care were significantly more likely to complete therapy withdrawal than those attending a specialist clinic (15.3% vs. 2.6%, P < 0.0001). The total annual cost of antiparkinson medication for these 36 patients was £13,400; the mean duration of diagnosis was 6.8 years (SD 5.6). At least 1 in every 20 patients taking medication for PD is misdiagnosed. Nearly all of these patients can be identified by simple screening of prescription databases and case records in Primary Care, followed by clinical review, which allows withdrawal of unnecessary medication. © 2009 Movement Disorder Society
Cold‐drawn induced microstructure in PVC‐bentonite nanocomposites
Authors: Romero‐Guzmán Maria Eugenia , Flores Osvaldo , Flores Araceli , Romo‐Uribe Angel , Alvarado‐Tenorio Bonifacio , Campillo Bernardo
Published: November 2009

The mechanical properties and cold drawn‐induced micro and nanostructure of polyvinyl chloride (PVC)‐bentonite nanocomposites have been investigated. Molded sheets with 5 wt% concentration of bentonite and two processing additives were melt extruded and two‐roll‐milled processed. The flame retardant additive promoted polymer intercalation whereas a pigment dispersant promoted clay exfoliation, the polymer matrix showed isotropic orientation. The intercalated nanocomposite exhibited nanoplates oriented with their planes parallel to the molded sheet surface and the Young's modulus and yield stress were significantly enhanced relative to neat PVC. The strain at fracture (∼144%) was slightly reduced relative to the matrix (∼167%). Cold drawing induced molecular chain orientation along the tensile axis and preserved the orientation of the intercalated nanoclays. The fracture mechanism, as investigated via scanning electron microscopy (SEM) revealed plastic fracture mechanism (similar to neat PVC). On the other hand, the exfoliated nanocomposite did not show any improvement in mechanical properties but rather a significant decay of strain at fracture (∼44%). The fractured region, as examined by SEM, exhibited microvoid morphology. Analysis of the fractured region showed PVC macromolecules oriented along the tensile axis but no preferred orientation of the nanoclays. The limited strain at fracture found for this material appears to be associated with the initially randomly oriented nanoclays being unable to orient under the tensile deformation. The nanoclays would act as stress concentrators leading to rapid material's failure due to loss of adhesion with the polymer matrix. The results suggest that exfoliated nanoclays could play a detrimental role when the nanocomposite is subjected to large deformations at temperatures well within the glassy regime. Copyright © 2009 John Wiley & Sons, Ltd.
Sternenstaub in Meteoriten und Kometen
Authors: Hoppe Peter
Published: November 2009

Die Entdeckung von Sternenstaub in wenig verändertem Material aus unserem Sonnensystem hat der Astronomie ein neues Fenster ins Weltall eröffnet. Mit Hilfe hochentwickelter Analysemethoden können diese Relikte aus der Frühzeit unseres Sonnensystems in irdischen Laboren detailliert auf ihre Isotopenzusammensetzungen, Chemie und Struktur hin untersucht werden. Daraus ergeben sich wichtige Rückschlüsse über die Elementsynthese in Sternen, Staubentstehung in der Umgebung von Sternen, chemische und physikalische Prozesse im interstellaren Medium und über die Frühgeschichte unseres Sonnensystems. Es ist sogar möglich, Sterntypen zu identifizieren, die Staub zum solaren Urnebel beigesteuert haben.
Handgemachte Hologramme. Spielwiese
Authors: Schlichting Hans‐Joachim , Ucke Christian
Published: November 2009

Konzentrische Rillen in einer reflektierenden Oberfläche beispielsweise einer CD rufen bei richtiger Betrachtung Lichterscheinungen hervor, die in der Luft zu schweben scheinen. Dieses Phänomen erlaubt es, mit einfachen Mitteln räumliche “Bilder” zu erzeugen, die Ähnlichkeit mit holografischen Abbildungen haben. Diese Ritztechnik fand sogar schon Eingang in die Kunst.
Eine Flasche für Licht
Authors: Rauschenbeutel Arno
Published: November 2009

Physikern der Universität Mainz ist es gelungen, einen Speicher für Licht zu realisieren, der bislang unvereinbare Eigenschaften aufweist: Er besteht nur aus einem einzelnen Bauelement und speichert Licht beliebiger Farben in einem mikroskopischen Volumen für extrem lange Zeit.
Die innere Struktur eines Moleküls
Authors: Bührke Thomas
Published: November 2009

Forscher von IBM Research – Zürich und der Universität Utrecht haben erstmals die chemische Struktur eines Moleküls mit einem Rasterkraftmikroskop atomar vollständig aufgelöst. Diese Technik könnte auch der Erforschung neuer elektronischer Bauelemente auf atomarer und molekularer Skala eröffnet.
Gekrümmte Ansichten
Authors: Schlichting H. Joachim
Published: November 2009

Schaut man durch ein gefülltes Weinglas auf einen Stift, so verwandelt sich das Bild in eine Art dreiarmigen Lüster. Dieses reizvolle Phänomen wird durch Mehrfachabbildungen erzeugt.
Die Cola‐Fontaine
Authors: Vilgis Thomas
Published: November 2009

Es gibt Experiment, die sollten nur im Freien ausgeführt werden. Dieses gehört dazu. Werfen Sie in eine geöffnete Flasche Cola‐Light ein paar Pfefferminzkaubonbons namens Mentos und bringen Sie sich schnell in Sicherheit, denn im Nu schießt eine gewaltige Cola‐Fontaine in die Höhe. Ursache ist die raue Oberfläche auf den Minzbonbons, die allerhand Kräfte in der Flüssigkeit freisetzen.
Planck läuft
Authors: Bührke Thomas
Published: November 2009

Nachdem das Infrarotobservatorium Herschel kürzlich erfolgreich in Betrieb genommen werden konnte (Physik in unserer Zeit 2009, 40 (5), 226), vermeldet die Europäische Weltraumorganisation, ESA, nun auch Erfolg bei dem gleichzeitig am 14. Mai gestarteten Teleskop Planck.
Physical Properties of Conventional Explosives Deduced from Radio Frequency Emissions
Authors: Harlin Jeremiah , Nemzek Robert
Published: November 2009

Los Alamos National Laboratory collected broadband radio frequency (RF) electric field change measurements from multiple detonations of high explosives (HE). Three types of HE were used: small cylinders of flake TNT, solid TNT, and PBX‐9501. Low frequency signals (<80 MHz) were shot‐to‐shot repeatable and occurred within the first 100 μs at measured amplitudes of about 2 V m−1 at 35  m distance. High frequency signals (>290 MHz) occurred later, were an order of magnitude lower in signal strength, and were not repeatable. There is a positive correlation between the maximum electric field change and the shock velocity of the HE. The amount of free charge produced in the explosion estimated from the first RF pulse is between 10 and 150 μC. This implies a weakly ionized plasma with temperatures between 2600 and 2900 K.
Osmolyte‐induced conformational changes in the Hsp90 molecular chaperone
Authors: Street Timothy O. , Krukenberg Kristin A. , Rosgen Jörg , Bolen D. Wayne , Agard David A.
Published: November 2009

Osmolytes are small molecules that play a central role in cellular homeostasis and the stress response by maintaining protein thermodynamic stability at controlled levels. The underlying physical chemistry that describes how different osmolytes impact folding free energy is well understood, however little is known about their influence on other crucial aspects of protein behavior, such as native‐state conformational changes. Here we investigate this issue with the Hsp90 molecular chaperone, a large dimeric protein that populates a complex conformational equilibrium. Using small angle X‐ray scattering we observe dramatic osmolyte‐dependent structural changes within the native ensemble. The degree to which different osmolytes affect the Hsp90 conformation strongly correlates with thermodynamic metrics of their influence on stability. This observation suggests that the well‐established osmolyte principles that govern stability also apply to large‐scale conformational changes, a proposition that is corroborated by structure‐based fitting of the scattering data, surface area comparisons and m‐value analysis. This approach shows how osmolytes affect a highly cooperative open/closed structural transition between two conformations that differ by a domain‐domain interaction. Hsp90 adopts an additional ligand‐specific conformation in the presence of ATP and we find that osmolytes do not significantly affect this conformational change. Together, these results extend the scope of osmolytes by suggesting that they can maintain protein conformational heterogeneity at controlled levels using similar underlying principles that allow them to maintain protein stability; however the relative impact of osmolytes on different structural states can vary significantly.
Characterisation of organic field‐effect transistors using metal phthalocyanines as active layers
Authors: Korodi Iulia G. , Lehmann Daniel , Tippo Tossapol , Hietschold Michael , Zahn Dietrich R. T.
Published: November 2009

In this work the performance of organic field‐effect transistors (OFETs) using Copper Phthalocyanine (CuPc) and Titanyl Phthalocyanine (TiOPc) as active layers is compared. Current/Voltage measurements were first performed in vacuum and later under ambient conditions. The highest hole mobility μvac = (1.5 ± 0.6) × 10–3 cm2/Vs was obtained for the CuPc OFETs. The mobility remained constant within the error bar after exposing the OFETs to atmosphere (μatm = (1.2 ± 0.2) x 10–3 cm2/Vs). For the TiOPc transistors a hole mobility of μvac = (7.2 ± 4.0) × 10–5 cm2/Vs was found in vacuum. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interaction induced transition in the nanoporous TiO2/Pd‐porphyrin system
Authors: Funes Matías , Zabel Philipp , Dittrich Thomas , Durantini Edgardo N. , Otero Luis
Published: November 2009

Molecules of Pd(II) 5‐(4‐carboxyphenyl)‐10,15,20‐tris(4‐methylphenyl) porphyrin were adsorbed from highly diluted dichloromethane solution on ultra‐thin layers of nanoporous TiO2 and investigated by modulated surface photovoltage (SPV) spectroscopy. An additional transition with a maximum at 2.03 eV appeared in the SPV spectra after moderate annealing in vacuum irrespective to the amount of adsorbed molecules. The new transition has been ascribed to the formation of a charge transfer complex due to an interaction between the Pd centred porphyrin and Ti surface atoms. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of wetting layer structure on surface phase stability and on indium surface diffusion
Authors: Rosini Marcello , Kratzer Peter , Magri Rita
Published: November 2009

We study the effects of surface reconstruction and step formation on the surface phase stability, of an InAs wetting layer on GaAs(001). In particular we focus our attention on the α2 and β2 (2 × 4) surface reconstructions. The two investigated reconstructions have been shown to be formed at an high In coverage, at the onset of the 2D→3D transition. The analysis of the connection between the step stability and the strain distribution around the step edges leads to the conclusion that the favoured step geometries are those minimising the strain. Finally, In diffusion on the flat reconstructed wetting layers has been investigated.We find: (i) the elements of the surface reconstructions favouring In diffusion; (ii) that In diffusion on these surfaces is strongly anisotropic, favoring the [‐110] direction; (iii) that the As surface dimers introduce additional adsorption sites with high barriers for In escape (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Brief Report: Interferon-γ Induces Expansion of Lin−Sca-1+C-Kit+ Cells
Authors: Zhao Xin , Ren Guangwen , Liang Li , Ai Phillip Z. , Zheng Betty , Tischfield Jay A. , Shi Yufang , Shao Changshun
Published: November 2009

The balance between Th1 and Th2 cells is critical for homeostasis of the immune system. Th1 cells can also regulate hematopoietic progenitor cell homeostasis by production of oncostatin M. Here we show that Th1 cell products, but not those of Th2 cells, caused a rapid expansion of lineage−Sca-1+C-kit+ (LSK) cells in vivo and in vitro. Among Th1 cytokines, interferon-γ (IFNγ) was found to play a major role in this expansion by activating the expression of Sca-1 in lineage−Sca-1−C-kit+ cells. This process was dependent on IFNγR1 signaling and the STAT1 pathway. Furthermore, those IFNγ-induced LSK cells had a higher proliferation potential than control LSK cells. In addition, while the overall production of colony-forming units in bone marrow was decreased after IFNγ treatment, the sorted LSK cells could give rise to a higher yield of colony-forming units. Finally, the IFNγ-induced hematopoiesis was biased toward the differentiation of myeloid lineages. Therefore, our findings demonstrated a novel role of IFNγ in activating hematopoietic progenitor cells and provide a new insight into the clinical application of interferon.
Recursive partitioning
Authors: Hawkins Douglas M.
Published: November 2009

Recursive partitioning (RP) is a predictive approach with minimal statistical or model assumptions, which models the relationship in terms of trees or dendrograms. It is particularly appropriate for initial exploration of large data sets, especially messy ones, and may either validate other approaches with stronger model assumptions or lead to a final analysis in its own right. It may be used for either a nominal scale (categorical) or an interval‐scale (numeric) dependent variable. A major issue is the size of tree to be fitted; different approaches for this have been proposed. Like many other feature selection methods, RP is unstable, the model being potentially sensitive to minor perturbations in the data. Fitting multiple trees helps explore alternative models, and also provides better predictions than those giving by a single tree. RP is well supported in both commercial and public domain software. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Data Reduction, Smoothing, and Filtering
Pancreatic head resection with segmental duodenectomy for pancreatic neoplasms
Authors: Nakao Akimasa , Takeda Shin , Nomoto Shuji , Kanazumi Naohito , Kasuya Hideki , Sugimoto Hiroyuki , Fujii Tsutomu , Yamada Suguru
Published: November 2009

Background/purpose

We have experienced 67 cases of pancreatic head resection with segmental duodenectomy (PHRSD) for benign or low‐grade malignant tumor of the pancreatic head region. Here we introduce our operative technique for these 67 cases.

Methods

Pancreatic head resection is performed with segmental duodenectomy including minor and major papilla. By conserving the right gastric artery and the gastroduodenal artery, 5–7 cm of the first portion of the duodenum is preserved with good arterial circulation. In addition, by conserving the anterior inferior pancreatoduodenal artery, the third portion and anal side or the second portion of the duodenum are preserved with good arterial circulation. Cholecystectomy is performed. The procedure is completed by resection of the pancreatic head with 3–4 cm of segmental duodenectomy including minor and major papilla. Reconstruction of the alimentary tract is performed with pancreatogastrostomy, end‐to‐end duodenoduodenostomy and end‐to‐side choledochoduodenostomy.

Results

In 67 cases with diseases of the pancreatic head region, chiefly intraductal papillary mucinous neoplasms, this procedure was successfully performed without operative or hospital death. Postoperative quality of life was quite satisfactory.

Conclusion

Total resection of the pancreatic head can be performed safely and effectively by this procedure.
Staging systems: Is there a surgical staging and a medical one? A surgeon's perspective
Authors: Contreras Carlo M. , Vauthey Jean‐Nicolas
Published: November 2009

From a surgeon's perspective, the AJCC 6th edition is the staging system of choice due to its simplified clinicopathologic schema, discriminatory accuracy, extensive external validation, widespread geographic reproducibility, and applicability to both the resection and transplantation patient population with hepatocellular carcinoma.
Single HCC between 2 and 5 cm: the grey zone
Authors: Hasegawa Kiyoshi , Kokudo Norihiro , Sano Keiji , Makuuchi Masatoshi
Published: November 2009

In the treatment of hepatocellular carcinoma (HCC), control of the tumor itself, vascular invasion, and minute intrahepatic metastases is the main important factor to be considered. Based on previously reported indirect evidence, liver resection would seem to have advantages over percutaneous ablation for single HCCs measuring between 2 and 5 cm in diameter. In conclusion, liver function permitting, resection would be the therapeutic option of first choice. In cases with poor liver functional reserve, liver transplantation would be a good therapeutic option, depending on the age of the patient.
Functional–structural models optimize the placement of foliage units for multiple whole‐canopy functions
Authors: Kennedy Maureen C.
Published: November 2009

I present examples of plant functional–structural models (FSMs) that are used to evaluate how foliage units affect whole‐canopy functions, and I show that multi‐criteria optimization is an effective tool for these models. FSMs produce plant structures through the repeated application of a set of rules for the placement of foliage units. The models are blind (rules are the same regardless of dynamic simulation conditions), sighted (rules change with interference from other foliage units) or self‐regulatory (rules change depending on the conditions of the simulation, i.e., internal conditions). In the examples presented, the models are used to optimize plant morphology for one or more measures of plant performance; these measures include movement of materials and associated hydraulic functions, foliage display, light interception and net carbon, mechanical support and stability, and reproductive success. It is consistently found that no morphology is optimal for any single measure of plant performance, and the rules for plant development are not stationary in space and time. In multi‐criteria optimization, alternative morphologies are compared against multiple measures of plant performance; these are optimized simultaneously using Pareto optimality, which yields the set of mutually co‐dominant solutions not dominated by any other solution. Two solutions are considered to be mutually co‐dominant if improvement with respect to one criterion is at the expense of another criterion. I conclude that multi‐criteria optimization is an essential tool for the use of FSMs to relate processes at the foliage level to whole‐canopy function and to explain the structural diversity of old‐growth forests.
tRNA‐nucleotidyltransferases: Highly unusual RNA polymerases with vital functions
Authors: Vörtler Stefan , Mörl Mario
Published: November 2009

tRNA‐nucleotidyltransferases are fascinating and unusual RNA polymerases responsible for the synthesis of the nucleotide triplet CCA at the 3′‐terminus of tRNAs. As this CCA end represents an essential functional element for aminoacylation and translation, these polymerases (CCA‐adding enzymes) are of vital importance in all organisms. With a possible origin of ancient telomerase‐like activity, the CCA‐adding enzymes obviously emerged twice during evolution, leading to structurally different, but functionally identical enzymes. The evolution as well as the unique polymerization features of these interesting proteins will be discussed in this review.