bluuebunny/crossref_metadata_2025 huggingface dataset:
Water use characteristics of black mangrove (Avicennia germinans) communities along an ecotone with marsh at a northern geographical limit
Authors: Krauss Ken W. , McKee Karen L. , Hester Mark W.
Published: December 2012

Mangroves are expanding into warm temperate‐zone salt marsh communities in several locations globally. Although scientists have discovered that expansion might have modest effects on ecosystem functioning, water use characteristics have not been assessed relative to this transition. We measured early growing season sapflow (Js) and leaf transpiration (Tr) in Avicennia germinans at a latitudinal limit along the northern Gulf of Mexico (Louisiana, United States) under both flooded and drained states and used these data to scale vegetation water use responses in comparison with Spartina alterniflora. We discovered strong convergence when using either Js or Tr for determining individual tree water use, indicating tight connection between transpiration and xylem water movement in small Avicennia trees. When Tr data were combined with leaf area indices for the region with the use of three separate approaches, we determined that Avicennia stands use approximately 1·0–1·3 mm d–1 less water than Spartina marsh. Differences were only significant with the use of two of the three approaches, but are suggestive of net conservation of water as Avicennia expands into Spartina marshes at this location. Average Js for Avicennia trees was not influenced by flooding, but maximum Js was greater when sites were flooded. Avicennia and Spartina closest to open water (shoreline) used more water than interior locations of the same assemblages by an average of 1·3 mm d−1. Lower water use by Avicennia may indicate a greater overall resilience to drought relative to Spartina, such that aperiodic drought may interact with warmer winter temperatures to facilitate expansion of Avicennia in some years. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Slow Self‐Assembly Favors Hysteresis above Room Temperature for an Iron(II) 1D‐Chain Spin‐Crossover Complex
Authors: Nowak René , Bauer Wolfgang , Ossiander Tanja , Weber Birgit
Published: December 2012

The X‐ray structures and magnetic properties of three new iron(II) coordination polymers with the general formula [FeL1(Lax)]n are presented. L1 is the tetradentate N2O22– Schiff‐base‐like ligand (E,E)‐{dimethyl‐2,2′‐[1,2‐phenylenebis(iminomethylidyne)]bis(3‐oxobutanato)(2–)‐N,N′,O3,O3′}. For the axial coordination, 4,4′‐bipyridine (bipy), 1,2‐bis(4‐pyridyl)ethane (bpea), and 1,2‐bis(4‐pyridyl)ethene (bpee) were used. Spin‐transition behavior was observed for the bpea and the bipy complexes. In both cases, two different polymorphs were isolated, showing different magnetic properties. In the case of the bipy complex 1, different preparation methods were tested to elucidate which conditions favor one polymorph over another. It appears that a slow precipitation of the coordination polymer favors a cooperative spin transition above room temperature, whereas a fast precipitation results in a gradual spin transition at lower temperatures. In the case of the bpea complex, an incomplete spin transition is observed, which can be explained by the crystal packing.
Effect of Spin‐Crossover‐Induced Pore Contraction on CO2–Host Interactions in the Porous Coordination Polymers [Fe(pyrazine)M(CN)4] (M = Ni, Pt)
Authors: Culp Jeffrey T. , Chen De‐Li , Liu Jinchen , Chirdon Danielle , Kauffman Kristi , Goodman Angela , Johnson J. Karl
Published: December 2012

Variable‐temperature in situ ATR‐FTIR spectra are presented for the porous spin‐crossover compounds [Fe(pyrazine)Ni(CN)4] and [Fe(pyrazine)Pt(CN)4] under CO2 pressures of up to 8 bar. Significant shifts in the ν3 and ν2 IR absorption bands of adsorbed CO2 are observed as the host materials undergo transition between low‐ and high‐spin states. Computational models used to determine the packing arrangement of CO2 within the pore structures show a preferred orientation of one of the adsorbed CO2 molecules with close O=C=O···H contacts with the pyrazine pillar ligands. The interaction is a consequence of the commensurate distance of the inter‐pyrazine separations and the length of the CO2 molecule, which allows the adsorbed CO2 to effectively bridge the pyrazine pillars in the structure. The models were used to assign the distinct shifts in the IR absorption bands of the adsorbed CO2 that arise from changes in the O=C=O···H contacts that strengthen and weaken in correlation with changes in the Fe–N bond lengths as the spin state of Fe changes. The results indicate that spin‐crossover compounds can function as a unique type of flexible sorbent in which the pore contractions associated with spin transition can affect the strength of CO2–host interactions.
Samarium Diiodide Promoted Reduction of 3,6‐Dihydro‐2H‐1,2‐oxazines: Competition of 1,4‐Amino Alcohol Formation and Ring Contraction to Pyrrole Derivatives
Authors: Jasiński Marcin , Watanabe Toshiko , Reissig Hans‐Ulrich
Published: December 2012

An approach to enantiopure 1,4‐amino alcohols of type 4 by samarium diiodide mediated N–O cleavage of 3,6‐dihydro‐2H‐1,2‐oxazines 3 is presented. In several cases we observed the formation of 3‐methoxypyrrole derivatives 5 as byproducts in significant amounts. For 1,2‐oxazine derivative syn‐3a, up to 27 % of pyrrole 5a was isolated. The examples presented show a strong dependence of the chemoselectivity on the structure of the precursor 1,2‐oxazines. The formation of pyrroles 5 as side‐products is rationalized by a competitive intramolecular hydrogen shift of the initially formed ring cleavage intermediate B to C and subsequent cyclization of aldehyde E to afford F. This pathway can be disfavoured when a higher excess of samarium diiodide was employed, which generally provided the 1,4‐amino alcohols 4 in good yields.
High‐Throughput Mercury Monitoring in Indoor Dust Microsamples by Bath Ultrasonic Extraction and Anodic Stripping Voltammetry on Gold Nanoparticles‐Modified Screen‐Printed Electrodes
Authors: Bernalte E. , Marín Sánchez C. , Pinilla Gil E.
Published: December 2012

A simple strategy based on the combination of a high‐throughput bath ultrasonic extraction with portable electrochemical determination was developed for fast Hg(II) monitoring in dust samples, with potential applicability to decentralized atmospheric pollution assessment. Square‐wave anodic stripping voltammetry (SWASV) on gold nanoparticles‐modified screen‐printed carbon electrodes (AuNPs‐SPCEs) coupled to the extraction procedure resulted in a convenient method for sensitive, reliable, and reproducible mercury detection. The proposed combination of techniques was evaluated with good agreement by using NIST Standard Reference Material 2583 Trace Elements in Indoor Dust. The method was successfully applied for Hg monitoring in complex and heterogeneous indoor dust samples collected at different indoor ambients. ICP‐MS was used to contrast the voltammetric measurements.
Voltammetric Determination of Trace Amounts of 2‐Aminofluoren‐9‐one at a Mercury Meniscus Modified Silver Solid Amalgam Electrode
Authors: Hájková Andrea , Hraníček Jakub , Barek Jiří , Vyskočil Vlastimil
Published: December 2012

Voltammetric behavior of the genotoxic environmental pollutant 2‐aminofluoren‐9‐one (2‐AFN) was investigated using direct current voltammetry (DCV), differential pulse voltammetry (DPV) and adsorptive stripping differential pulse voltammetry (AdSDPV) at a mercury meniscus modified silver solid amalgam electrode (m‐AgSAE). Optimum conditions were found for its DCV and DPV determination in a methanolBrittonRobinson buffer pH 4.0 (1 : 9, v/v) medium (in a concentration range from 0.1 to 100 µmol L−1 of 2‐AFN) and for its AdSDPV determination in a 0.2 mol L−1 acetate buffer pH 4.0 medium (from 0.01 to 0.1 µmol L−1 of 2‐AFN), with limits of quantification (LQs) of 0.2, 0.1 and 0.005 µmol L−1 for DCV, DPV and AdSDPV, respectively. For comparison, the UV spectrophotometric (measured at 274 nm) and fluorimetric (measured at 460 nm, using the excitation wavelength of 314 nm) determination of 2‐AFN were carried out in methanol, with LQs of 0.1 and 2 µmol L−1, respectively. Practical applicability of the newly developed voltammetric methods was verified on direct determination of 2‐AFN in model samples of drinking and river water, with the lowest LQs in the range of 5–10 nmol L−1.
Comparison of Glucose Oxidation by Crosslinked Redox Polymer Enzyme Electrodes Containing Carbon Nanotubes and a Range of Glucose Oxidising Enzymes
Authors: MacAodha Domhnall , Ó Conghaile Peter , Egan Brenda , Kavanagh Paul , Sygmund Christoph , Ludwig Roland , Leech Dónal
Published: December 2012

The sugar oxidising enzymes glucose oxidase, glucose dehydrogenases (GDH) and cellobiose dehydrogenases (CDH) were co‐immobilised, in the presence of multiwalled carbon nanotubes, with osmium redox polymers. Under pseudo‐physiological conditions of 5 mM glucose, 150 mM NaCl, 37 °C, glucose oxidation current densities above 800 µA cm−2 are obtained from films containing an [Os(4,4′‐dimethyl‐2,2′‐bipyridine)2(poly‐vinylimidazole)10Cl]+ redox polymer, redox potential 0.1 V vs. Ag/AgCl, and either glucose oxidase or FAD‐dependant GDH. Current produced by, and stability of, glucose‐oxidising half‐cells is compared in 100 mM glucose, with films containing CDHs proving most stable. Such results show promise for development of glucose‐oxidising enzymatic fuel cells.
Myristoylated PreS1-domain of the hepatitis B virus L-protein mediates specific binding to differentiated hepatocytes
Authors: Meier Anja , Mehrle Stefan , Weiss Thomas S. , Mier Walter , Urban Stephan
Published: December 2012

Chronic infection with the human hepatitis B virus (HBV) is a global health problem and a main cause of progressive liver diseases. HBV exhibits a narrow host range, replicating primarily in hepatocytes. Both host and hepatocyte specificity presumably involve specific receptor interactions on the target cell; however, direct evidence for this hypothesis is missing. Following the observation that HBV entry is specifically blocked by L-protein-derived preS1-lipopeptides, we visualized specific HBV receptor/ligand complexes on hepatic cells and quantified the turnover kinetics. Using fluorescein isothiocyanate-labeled, myristoylated HBV preS1-peptides we demonstrate (1) the presence of a highly specific HBV receptor on the plasma membrane of HBV-susceptible primary human and tupaia hepatocytes and HepaRG cells but also on hepatocytes from the nonsusceptible species mouse, rat, rabbit and dog; (2) the requirement of a differentiated state of the hepatocyte for specific preS1-binding; (3) the lack of detectable amounts of the receptor on HepG2 and HuH7 cells; (4) a slow receptor turnover at the hepatocyte membrane; and (5) an association of the receptor with actin microfilaments. The presence of the preS1-receptor in primary hepatocytes from some non-HBV-susceptible species indicates that the lack of susceptibility of these cells is owed to a postbinding step. Conclusion: These findings suggest that HBV hepatotropism is mediated by the highly selective expression of a yet unknown receptor* on differentiated hepatocytes, while species specificity of the HBV infection requires selective downstream events, e.g., the presence of host dependency or the absence of host restriction factors. The criteria defined here will allow narrowing down reasonable receptor candidates and provide a binding assay for HBV-receptor expression screens in hepatic cells. (HEPATOLOGY 2013)
Vitamin A deficiency is associated with hepatitis C virus chronic infection and with unresponsiveness to interferon-based antiviral therapy
Authors: Bitetto Davide , Bortolotti Nadia , Falleti Edmondo , Vescovo Sara , Fabris Carlo , Fattovich Giovanna , Cussigh Annarosa , Cmet Sara , Fornasiere Ezio , Ceriani Elisa , Pirisi Mario , Toniutto Pierluigi
Published: December 2012

Recent data suggest that vitamin A modulates the expression of type I interferon receptor enhancing the antireplication effect of interferon-α on hepatitis C virus (HCV). This study aimed to investigate the prevalence of vitamin A deficiency among patients with chronic HCV infection and to assess whether vitamin A deficiency could be associated with unresponsiveness to interferon-based antiviral therapy. The analysis included 199 consecutive treatment-naïve chronic HCV patients in whom pretreatment serum vitamin A and 25-OH vitamin D were measured; 119 healthy blood donors were used as controls. Median (interquartile range) serum vitamin A in HCV-positive patients was significantly lower than in controls: 256 ng/mL (128–440) versus 742 (624–942,

P

< 0.0001). Overall sustained viral response was achieved in 122/199 patients, 46/109 infected by difficult to treat HCV genotypes. In these latter, 39/104 (37.5%) were nonresponders. At multivariate analysis, nonresponse to antiviral therapy was predicted by carriage of interleukin (IL)-28B T/* genotypes, baseline serum levels of γGT >60 IU/mL, of HCV RNA >600,000 IU/mL, of vitamin A ≤100 ng/mL, and a cumulative dose of ribavirin ≤80%. Seventeen patients (9.0%) had both serum levels of vitamin A ≤100 ng/mL and of vitamin D ≤20 ng/mL; the presence of a combined vitamin A and D deficiency was found to be a strong independent predictor of nonresponse to antiviral therapy.

Conclusion
: A high percentage of patients with chronic HCV infection have serum vitamin A deficiency. This condition is associated with nonresponse to antiviral therapy. (Hepatology 2013)
Bile salt export pump is dysregulated with altered farnesoid X receptor isoform expression in patients with hepatocellular carcinoma
Authors: Chen Yuan , Song Xiulong , Valanejad Leila , Vasilenko Alexander , More Vijay , Qiu Xi , Chen Weikang , Lai Yurong , Slitt Angela , Stoner Matthew , Yan Bingfang , Deng Ruitang
Published: December 2012

As a canalicular bile acid effluxer, the bile salt export pump (BSEP) plays a vital role in maintaining bile acid homeostasis. BSEP deficiency leads to severe cholestasis and hepatocellular carcinoma (HCC) in young children. Regardless of the etiology, chronic inflammation is the common pathological process for HCC development. Clinical studies have shown that bile acid homeostasis is disrupted in HCC patients with elevated serum bile acid level as a proposed marker for HCC. However, the underlying mechanisms remain largely unknown. In this study, we found that BSEP expression was severely diminished in HCC tissues and markedly reduced in adjacent nontumor tissues. In contrast to mice, human BSEP was regulated by farnesoid X receptor (FXR) in an isoform-dependent manner. FXR-α2 exhibited a much more potent activity than FXR-α1 in transactivating human BSEP

in vitro

and

in vivo

. The decreased BSEP expression in HCC was associated with altered relative expression of FXR-α1 and FXR-α2. FXR-α1/FXR-α2 ratios were significantly increased, with undetectable FXR-α2 expression in one third of the HCC tumor samples. A similar correlation between BSEP and FXR isoform expression was confirmed in hepatoma Huh7 and HepG2 cells. Further studies showed that intrahepatic proinflammatory cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), were significantly elevated in HCC tissues. Treatment of Huh7 cells with IL-6 and TNF-α resulted in a marked increase in FXR-α1/FXR-α2 ratio, concurrent with a significant decrease in BSEP expression.

Conclusion

: BSEP expression is severely diminished in HCC patients associated with alteration of FXR isoform expression induced by inflammation. Restoration of BSEP expression through suppressing inflammation in the liver may reestablish bile acid homeostasis.
Incorporation of fibronectin to enhance cytocompatibility in multilayer elastin‐like protein scaffolds for tissue engineering
Authors: Ravi Swathi , Caves Jeffrey M. , Martinez Adam W. , Haller Carolyn A. , Chaikof Elliot L.
Published: December 2012

Recombinant, elastin‐like protein (ELP) polymers are of significant interest for the engineering of compliant, resilient soft tissues due to a wide range of tunable mechanical properties, biostability, and biocompatibility. Here, we enhance endothelial cell (EC) and mesenchymal stem cell compatibility with ELP constructs by addition of fibronectin (Fn) to the surface or bulk of ELP hydrogels. We find that cell adhesion, proliferation, and migration can be modulated by Fn addition. Adsorption of Fn to the hydrogel surface is more efficient than bulk blending. Surface immobilization of Fn by genipin crosslinking leads to stability without loss of bioactivity. Gels of varying mechanical modulus do not alter cell adhesion, proliferation, and migration in the range we investigate. However, more compliant gels promote an EC morphology suggesting tubulogenesis or network formation, whereas stiffer gels promote cobblestone morphology. Multilayer structures consisting of thin ELP sheets reinforced with collagen microfiber are fabricated and laminated through the culture of MSCs at layer interfaces. High cell viability in the resulting three‐dimensional constructs suggests the applicability of Fn to the design of strong, resilient artificial blood vessels and other soft tissue replacements. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Bioactivity and hemocompatibility study of amorphous hydrogenated carbon coatings produced by pulsed magnetron discharge
Authors: Lopez‐Santos C. , Colaux J. L. , Laloy J. , Fransolet M. , Mullier F. , Michiels C. , Dogné J.‐M. , Lucas S.
Published: December 2012

Literature contains very few data about the potential biomedical application of amorphous hydrogenated carbon (a‐C:H) thin films deposited by reactive pulsed magnetron discharge even so it is one of the most scalable plasma deposition technique. In this article, we show that such a C2H2 pulsed magnetron plasma produces high quality coating with good hemocompatibility and bioactive response: no effect on hemolysis and hemostasis were observed, and proliferation of various cell types such as endothelial, fibroblast, and osteoblast‐like cells was not affected when the deposition conditions were varied. Cell growth on a‐C:H coatings is proposed to take place by a two‐step process: the initial cell contact is affected by the smooth topography of the a‐C:H coatings, whereas the polymeric‐like structure, together with a moderate hydrophilicity and a high hydrogen content, directs the posterior cell spreading while preserving the hemocompatible behavior. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Early healing in alveolar sockets grafted with titanium granules. An experimental study in a dog model
Authors: Arruda Thiago , Sukekava Flávia , de Souza André B. , Rasmusson Lars , Araújo Maurício G.
Published: December 2012

The aim of the present study was to evaluate the effect of the placement of titanium granules in fresh extraction sockets on early bone formation. The mesial roots of the third maxillary premolars of five adult beagle dogs were removed. On one side of the maxilla (Test group) the fresh extraction socket was grafted with titanium granules, while the contra‐lateral socket was left non‐grafted (Control group). After 1 month of healing, the dogs were euthanized and biopsies were obtained. The healing tissues were described, and histometric measurements were performed to obtain the percentage area occupied by connective tissue, new mineralized bone, bone marrow, and biomaterial particles. After 1 month of healing the findings from the histological examination revealed the titanium graft to be well incorporated into the provisional connective tissue or newly formed woven bone. The histometric measurements showed, however, that less mineralized bone was formed in the Test group than in the Control group. The present study suggests that the use of titanium granules in fresh extraction sockets was conducive to new bone formation. The graft of titanium granules seems, however, to delay the early phase of the healing process. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
HIFs, angiogenesis, and cancer
Authors: Yang Yongzhi , Sun Mingjuan , Wang Lianghua , Jiao Binghua
Published: December 2012

Tumor hypoxia was first described in the 1950s by radiation oncologists as a frequent cause of failure to radiotherapy in solid tumors. Today, it is evident that tumor hypoxia is a common feature of many cancers and the master regulator of hypoxia, hypoxia‐inducible factor‐1 (HIF‐1), regulates multiple aspects of tumorigenesis, including angiogenesis, proliferation, metabolism, metastasis, differentiation, and response to radiation therapy. Although the tumor hypoxia response mechanism leads to a multitude of downstream effects, it is angiogenesis that is most crucial and also most susceptible to molecular manipulation. The delineation of molecular mechanisms of angiogenesis has revealed a critical role for HIF‐1 in the regulation of angiogenic growth factors. In this article, we review what has been described about HIF‐1: its structure, its regulation, and its implication for cancer therapy and we focus on its role in angiogenesis and cancer. J. Cell. Biochem. 114: 967–974, 2013. © 2012 Wiley Periodicals, Inc.
Genetic and molecular control of osterix in skeletal formation
Authors: Sinha Krishna M. , Zhou Xin
Published: December 2012

Osteoblast differentiation is a multi‐step process where mesenchymal cells differentiate into osteoblast lineage cells including osteocytes. Osterix (Osx) is an osteoblast‐specific transcription factor which activates a repertoire of genes during differentiation of preosteoblasts into mature osteoblasts and osteocytes. The essential role of Osx in the genetic program of bone formation and in bone homeostasis is well established.Osxmutant embryos do not form bone and fail to express osteoblast‐specific marker genes. Inactivation ofOsxin mice after birth causes multiple skeletal phenotypes including lack of new bone formation, absence of resorption of mineralized cartilage, and defects in osteocyte maturation and function. Since Osx is a major effector in skeletal formation, studies on Osx gained momentum over the last 5–7 years and implicated its important function in tooth formation as well as in healing of bone fractures. This review outlines mouse genetic studies that establish the essential role of Osx in bone and tooth formation as well as in healing of bone fractures. We also discuss the recent advances in regulation ofOsxexpression, which is under control of a transcriptional network, signaling pathways, and epigenetic regulation. Finally, we summarize important findings on the positive and negative regulation of Osx's transcriptional activity through protein–protein interactions in expression of its target genes during osteoblast differentiation. In particular, the identification of the histone demethylase NO66 as an Osx‐interacting protein, which negatively regulates Osx activity opens further avenues in studying epigenetic control of Osx target genes during differentiation and maturation of osteoblasts. J. Cell. Biochem. 114: 975–984, 2013. © 2012 Wiley Periodicals, Inc.
Baicalein protects against cardiac hypertrophy through blocking MEK‐ERK1/2 signaling
Authors: Zong Jing , Zhang Da‐ping , Zhou Heng , Bian Zhou‐yan , Deng Wei , Dai Jia , Yuan Yuan , Gan Hua‐wen , Guo Hai‐peng , Tang Qi‐zhu
Published: December 2012

Baicalein, a flavonoid present in the root of Scutellaria baicalensis, is well known for its antibacterial, antiviral, anti‐inflammatory, antithrombotic, and antioxidant effects. Here we show that baicalein also attenuates cardiac hypertrophy. Aortic banding (AB) was performed to induce cardiac hypertrophy secondary to pressure overload in mice. Mouse chow containing 0.05% baicalein (dose: 100 mg/kg/day baicalein) was begun 1 week prior to surgery and continued for 8 weeks after surgery. Our data demonstrated that baicalein prevented cardiac hypertrophy and fibrosis induced by AB, as assessed by echocardiographic and hemodynamic parameters and by pathological and molecular analysis. The inhibitory action of baicalein on cardiac hypertrophy was mediated by effects on mitogen‐activated protein kinase kinase (MEK)‐extracellular signal‐regulated kinases (ERK1/2) signaling and GATA‐4 activation. In vitro studies performed in rat cardiac H9c2 cells confirmed that baicalein attenuated cardiomyocyte hypertrophy induced by angiotensin II, which was associated with inhibiting MEK‐ERK1/2 signaling. In conclusion, our results suggest that baicalein has protective potential for targeting cardiac hypertrophy and fibrosis through suppression of MEK‐ERK1/2 signaling. Baicalein warrants further research as a potential antihypertrophic agent that might be clinically useful to treat cardiac hypertrophy and heart failure. J. Cell. Biochem. 114: 1058–1065, 2013. © 2012 Wiley Periodicals, Inc.
Comment on “Extending Hirshfeld‐I to bulk and periodic materials”
Authors: Manz Thomas A.
Published: December 2012

In recent years, several methods have been developed that partition the electron density among atoms using spherically symmetric atomic weights. D. E. P. Vanpoucke, P. Bultinck, and I. Van Driessche (J. Comput. Chem. 2012, doi: 10.1002/jcc.23088) recently reported a periodic implementation of the Hirshfeld‐I method that uses a combination of Becke‐style and uniform integration grids and modified atomic reference densities to compute net atomic charges in periodic materials. Herein, this method is discussed in the context of earlier periodic implementations of the Hirshfeld‐I method, the Iterated Stockholder Atoms method, and the density derived electrostatic and chemical method.
Detecting abrupt change on the basis of skewness: numerical tests and applications
Authors: He Wenping , Wan Shiquan , Jiang Yundi , Jin Hongmei , Zhang Wen , Wu Qiong , He Tao
Published: December 2012

An abrupt change occasionally occurs when the dynamical system suddenly shifts from one stable state to a new state, which can take place in many complex systems, such as climate, ecosystem, social system, and so on. In order to detect abrupt change, this article presents a novel method – sliding transformation parameter (STP) on the basis of skewness change and the Box–Cox transformation. Tests on model time series and 1000 simulated daily precipitation data show the ability of the present method to identify and detect abrupt change of probability density function. The applications ofSTPin daily precipitation data show that there is an abrupt climate change between 1979 and 1980 in the selected observational stations, which is almost the same with the result obtained by approximate entropy (ApEn). Furthermore, it is found that the sample sizes of sliding windows have some influence on the Lambda parameter of the Box–Cox transformation, but it does not significantly affect the varying trend of the parameter and the identification of the change point in annual or interannual time scale. ComparingSTPwith the coefficient of skewness and kurtosis,ApEn, and some statistics approaches (e.g. percentiles and annual maxima), we find that the performance of the present method is much better than that of these methods.
Novel nondopaminergic targets for motor features of Parkinson's disease: Review of recent trials
Authors: Kalia Lorraine V. , Brotchie Jonathan M. , Fox Susan H.
Published: December 2012

Neurotransmitters other than dopamine are recognized as having modulatory roles within the basal ganglia and can influence the basal ganglia dopaminergic system to alter activity of the direct and indirect pathways. Many nondopaminergic neurotransmitter systems have been implicated in the mechanisms contributing to the motor features of Parkinson's disease (PD). Thus, it is now well established that neurotransmitter systems, including glutamatergic, GABAergic, cholinergic, noradrenergic, serotonergic, opioidergic, histaminergic, and adenosinergic systems, are affected in the pathogenesis of PD. Nondopaminergic neurotransmitter systems are thus targets for the development of novel therapies for motor symptoms and motor complications in PD. Over the last 5 years, more than 20 randomized, control trials (RCTs) in PD investigating drugs that target several of these nondopaminergic neurotransmitter systems for the treatment of motor features have been completed. There are at least 15 additional RCTs that are ongoing or planned. Here, we review these RCTs to highlight the potential nondopaminergic pharmacological therapies for treatment of motor features of PD. Nondopaminergic drugs are not expected to replace dopaminergic strategies, but further development of these drugs will likely yield novel approaches with positive clinical implications. © 2012 Movement Disorder Society
EXTENDING SELF‐MANAGEMENT STRATEGIES: THE USE OF A CLASSWIDE APPROACH
Authors: Hoff Kathryn E. , Ervin Ruth A.
Published: December 2012

Notwithstanding the wealth of research that documents the effectiveness of self‐management programs in the classroom, few investigations have explored classwide use of self‐management procedures as a universal intervention. To extend existing research in this area, we examined the effectiveness of a classwide self‐management intervention for decreasing disruptive behaviors among three at‐risk second‐grade students. We used a multiple baseline across subjects design and evaluated the effects of the self‐management program at both the individual and classwide levels during academic instruction time. Results of the study showed a decrease in disruptive behaviors of the target students and a general decrease in classroom disruptive behavior. In addition, teachers and students provided positive ratings of intervention acceptability and feasibility. Limitations, implications, and future directions for research are discussed.
Use of mindfulness‐based therapies in psychiatry
Authors: Singh Aoife
Published: December 2012

Mindfulness is an ancient concept conveying the idea of experiencing the present non‐judgementally and openly, allowing oneself to develop a greater sense of emotional balance and well‐being. There is growing evidence that mindfulness‐based therapies are effective for a wide range of medical conditions. In this review, Dr Singh explores the clinical application of mindfulness to various psychiatric conditions.
A case of ADHD in a patient with Noonan syndrome
Authors: Mushtaq Imran , Matras Bartlomiej
Published: December 2012

Noonan syndrome is a genetic disorder characterised by several features including short stature, congenital heart defects and learning problems. Here, Dr Mushtaq and colleagues describe how they managed a case of ADHD in a patient with Noonan syndrome.
Establishing capacity in a patient with incomplete locked‐in syndrome
Authors: Carrington Sarah , Birns Jonathan
Published: December 2012

Patients with locked‐in syndrome may have retained mental capacity to make decisions about their care and it is important that healthcare professionals prioritise communication rehabilitation. Here, Sarah Carrington and Jonathan Birns describe how they established capacity in a patient with incomplete locked‐in syndrome and helped him to communicate his current wishes regarding his treatment.
Studies offer new insights into the characteristics of ADHD in adults
Authors: Greener Mark
Published: December 2012

While children and adolescents have traditionally attracted much of the attention, recent studies offer new insights into the causes, consequences and treatment of ADHD in adults. Mark Greener reports.
Antioxidant behaviour of 2′‐hydroxy‐chalcones: a study of their electrochemical properties
Authors: Serifi Olga , Tsopelas Fotios , Kypreou Anna‐Maria , Ochsenkühn‐Petropoulou Maria , Kefalas Panagiotis , Detsi Anastasia
Published: December 2012

The electrochemical behaviour of 13 chalcone analogues was systematically studied by means of cyclic voltammetry and chronoamperometry at a glassy carbon (GC), gold and platinum working electrodes using two different supporting electrolyte/solvent combinations. It was found that chalcone analogues can be easily oxidized at both GC and gold working electrodes, but not at a platinum electrode. Principal component analysis was further employed to reveal similarities/dissimilarities between oxidation potentials, chronoamperometric signals and ability of the compounds to scavenge the reactive oxygen species H2O2. The study reveals the inverse proportional relationship between the scavenging ability of H2O2, expressed as IC50, and chronoamperometric signal at 800 mV using gold as working electrode. Copyright © 2012 John Wiley & Sons, Ltd.
The mechanism investigation of the imidazolidinone catalyzed five‐membered ring synthesis reaction
Authors: Zhang Lili , Liu Huiling , Yang Yuhong , Chong Zhihui , Feng Tingting , Huang Xuri
Published: December 2012

The intramolecular asymmetric Michael addition reaction catalyzed by imidazolidinone is investigated using the density functional theory calculations. The details of the reaction mechanism, potential energy surfaces, and the influence of the acid additive are investigated. The reaction process includes two stages. The first stage is Michael addition, in which the enamine complex is created and then the Michael addition is carried out. The second stage is a product separation stage which includes an enol‐keto tautomerization and a two‐step hydrolysis. The enantioselectivity is controlled by the Michael addition step which involves a new carbon–carbon bond formation. The calculation results provide a general model which may explain the mechanism and enantioselectivity of the title reaction. Copyright © 2012 John Wiley & Sons, Ltd.
SET‐LRP synthesis of PMHDO‐g‐PNIPAM well‐defined amphiphilic graft copolymer
Authors: Ding Aishun , Lu Guolin , Guo Hao , Zheng Xingliang , Huang Xiaoyu
Published: December 2012

A well‐defined amphiphilic graft copolymer, consisting of hydrophobic polyallene‐based backbone and hydrophilic poly(N‐isopropylacrylamide) (PNIPAM) side chains, was prepared by the combination of living coordination polymerization, single electron transfer‐living radical polymerization (SET‐LRP), and the grafting‐from strategy. First, the double‐bond‐containing backbone was prepared by [(η3‐allyl)NiOCOCF3]2‐initiated living coordination polymerization of 6‐methyl‐1,2‐heptadiene‐4‐ol (MHDO). Next, the pendant hydroxyls in every repeating unit of poly(6‐methyl‐1,2‐heptadiene‐4‐ol) (PMHDO) homopolymer were treated with 2‐chloropropionyl chloride to give PMHDO‐Cl macroinitiator. Finally, PNIPAM side chains were grown from PMHDO backbone via SET‐LRP of N‐isopropylacrylamide initiated by PMHDO‐Cl macroinitiator in N,N‐dimethylformamide/2‐propanol using copper(I) chloride/tris(2‐(dimethylamino)ethyl)amine as catalytic system to afford PMHDO‐g‐PNIPAM graft copolymers with a narrow molecular weight distribution (Mw/Mn = 1.19). The critical micelle concentration (cmc) in water was determined by fluorescence probe technique and the effects of pH and salinity on the cmc of PMHDO‐g‐PNIPAM were also investigated. The micellar morphology was found to be spheres using transmission electron microscopy. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Synthesis of PMHDO‐g‐PDEAEA well‐defined amphiphilic graft copolymer via successive living coordination polymerization and SET‐LRP
Authors: Lu Guolin , Li Yongjun , Gao Hongsheng , Guo Hao , Zheng Xingliang , Huang Xiaoyu
Published: December 2012

A series of well‐defined amphiphilic graft copolymer containing hydrophobic polyallene‐based backbone and hydrophilic poly(2‐(diethylamino)ethyl acrylate) (PDEAEA) side chains was synthesized by sequential living coordination polymerization of 6‐methyl‐1,2‐heptadiene‐4‐ol (MHDO) and single electron transfer‐living radical polymerization (SET‐LRP) of 2‐(diethylamino)ethyl acrylate (DEAEA). Ni‐catalyzed living coordination polymerization of MHDO was first performed in toluene to give a well‐defined double‐bond‐containing poly(6‐methyl‐1,2‐heptadiene‐4‐ol) (PMHDO) homopolymer with a low polydispersity (Mw/Mn = 1.10). Next, 2‐chloropropionyl chloride was used for the esterification of pendant hydroxyls in every repeating unit of the homopolymer so that the homopolymer was converted to PMHDO‐Cl macroinitiator. Finally, SET‐LRP of DEAEA was initiated by the macroinitiator in tetrahydrofuran/H2O using CuCl/tris(2‐(dimethylamino)ethyl)amine as catalytic system to afford well‐defined PMHDO‐g‐PDEAEA graft copolymers (Mw/Mn ≤ 1.22) through the grafting‐from strategy. The critical micelle concentration (cmc) was determined by ﬂuorescence spectroscopy with N‐phenyl‐1‐naphthylamine as probe and the micellar morphology was visualized by transmission electron microscopy. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Functional polysilanes of relevance for the synthesis of Au and Au–Pd nanoparticle assemblies—a study on the role of polymer‐supported thioether side chains
Authors: Shankar Ravi , Sahoo Usharani
Published: December 2012

Linear polysilanes, [{PhHSi}x{Ph(RSCH2CH2CH2)Si}1−x]n [R = n‐dodecyl (1), n‐hexyl (2), n‐butyl (3)], have been synthesized and their reactivity with HAuCl4·3H2O (Polymer:Au = 10:1, RT, toluene) examined to gain an insight into the role of polymer‐supported thioether groups in the stabilization of in situ generated gold nanoparticles (AuNPs). The method allows a simple approach for expeditious synthesis of assemblies of AuNPs comprising of well‐separated individual nanoparticles of average diameter 4.5 ± 1.9 nm. In this regard, polysilane 1 with dodecyl side chains serves as a superior matrix than 2 and 3 and confers long shelf‐life stability to the nanoparticle assembly. The structural attributes are preserved in Au–Pd bimetallic nanoparticles which have been synthesized from the polymer‐gold nanoassembly. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Gelation and adhesion behavior of mussel adhesive protein mimetic polymer
Authors: Nishida Jin , Kobayashi Motoyasu , Takahara Atsushi
Published: December 2012

An acrylamide‐type copolymer containing catechol, amino, and hydroxyl groups was synthesized as a mimetic of the natural mussel adhesive protein (MAP). The obtained copolymer in a phosphate buffer solution (pH = 8.0) formed a hydrogel within 2 h under air, whereas gelation did not proceed under argon atmosphere. We confirmed that the cross‐linking reaction of the synthesized MAP mimetic copolymer was triggered by aerobic oxidation of catechol moieties to form an adhesive hydrogel. Two aluminum plates were adhered by the gelation of the MAP mimetic copolymer solution under humid air at room temperature. The interfacial region between the two aluminum plates failed at a lap shear strength of 0.46 MPa due to cohesive failure of the hydrogel. The adhesion strength was dominated by mechanical strength of the hydrogel as well as the interface interaction of catechol groups with substrate surface. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Multiple exciton generation in PbSe and PbS nanocrystals incorporated into amorphous silicon p–n junction
Authors: Krivoshlykov Sergei G.
Published: December 2012

The effect of multiple exciton generation in semiconductor nanocrystals suggesting the possibility of efficient conversion of each absorbed high‐energy photon into at least two electron–hole pairs (excitons) is demonstrated in the photocurrent from lead selenide (PbSe) and lead sulfide (PbS) colloidal nanocrystals incorporated into amorphous silicon p–n junction. It is shown that employment of this effect for increasing efficiency of solar cells requires such energy bandgap alignment in the system that ensures confinement of the photogenerated charge carriers inside the nanocrystal layer.
Extended deep‐level defects in MBE‐grown p‐type CdTe layers
Authors: Olender Karolina , Wosinski Tadeusz , Makosa Andrzej , Dluzewski Piotr , Kolkovsky Valery , Tkaczyk Zbigniew , Karczewski Grzegorz
Published: December 2012

Five deep‐level hole traps, associated with native defects, have been revealed by means of deep‐level transient spectroscopy in p‐type CdTe layers grown on highly mismatched GaAs substrate by the molecular‐beam epitaxy technique. Two of the traps have been attributed to the electronic states of dislocations on the ground of the logarithmic capture kinetics for capture of holes into the traps states. The images taken by transmission electron microscopy show that they are probably threading dislocations of 60°‐type, generated at the mismatched interface with the substrate. One trap, which was observed only when the investigated space charge region was close to the metal–semiconductor interface, has been assigned to surface defect states. The last two traps, displaying exponential capture kinetics, have been ascribed to native point defects: the Cd vacancy and a complex formed of Cd vacancy and Te antisite, produced during the epitaxial growth of the CdTe layers. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dissociation of the 60° basal dislocation in wurtzite GaN
Authors: Belabbas I. , Chen J. , Komninou Ph. , Nouet G.
Published: December 2012

We have carried out atomistic calculations, using a self‐consistent tight‐binding method based on density functional theory, to determine formation energies of different core configurations of the perfect 60° and 90°, 30° Shockley partial dislocations in wurtzite GaN. Our analysis of different combinations of core configurations concluded that a 60° dislocation with a Ga polarity dissociates into a 90° partial dislocation with a single period and a 30° partial dislocation with a double period structure. Otherwise, a N polarity 60° dislocation dissociates into a 90° partial dislocation with a double period and a 30° partial dislocation with a single period structure (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Options in the Implementation Plan of Entrepreneurial Initiatives: Examining Firms' Attainment of Flexibility Benefit
Authors: Klingebiel Ronald
Published: December 2012

The value of real options has been discussed extensively—it helps explain managerial decisions in designing the rollout of bold initiatives in uncertain environments. However, few studies directly trace the impact of option usage on the performance of such entrepreneurial initiatives. Do all firms benefit from the flexibility that options confer? To answer this question, I collected detailed survey data on individual options designed into the implementation plans of entrepreneurial initiatives, focusing exclusively on options that were, eventually, in the money. The sample observations display significant variation in the degree to which flexibility benefit was realized from options, if at all. I find that this variance stems, in part, from heterogeneous organizational capability, regarding not only option creation but also option maintenance, exercise, and governance. These results imply that attainable benefit is highly firm specific. Holding valuable options does not predict performance of entrepreneurial initiatives, unless it is accompanied by active management of the option life cycle. Copyright © 2012 Strategic Management Society.
Longitudinal measurement in health‐related surveys. A Bayesian joint growth model for multivariate ordinal responses
Authors: Verhagen Josine , Fox Jean‐Paul
Published: December 2012

Longitudinal surveys measuring physical or mental health status are a common method to evaluate treatments. Multiple items are administered repeatedly to assess changes in the underlying health status of the patient. Traditional models to analyze the resulting data assume that the characteristics of at least some items are identical over measurement occasions. When this assumption is not met, this can result in ambiguous latent health status estimates. Changes in item characteristics over occasions are allowed in the proposed measurement model, which includes truncated and correlated random effects and a growth model for item parameters. In a joint estimation procedure adopting MCMC methods, both item and latent health status parameters are modeled as longitudinal random effects. Simulation study results show accurate parameter recovery. Data from a randomized clinical trial concerning the treatment of depression by increasing psychological acceptance showed significant item parameter shifts. For some items, the probability of responding in the middle category versus the highest or lowest category increased significantly over time. The resulting latent depression scores decreased more over time for the experimental group than for the control group and the amount of decrease was related to the increase in acceptance level. Copyright © 2012 John Wiley & Sons, Ltd.
Interim treatment selection with a flexible selection margin in clinical trials
Authors: Wu Yujun , Zhao Peng‐Liang
Published: December 2012

When several treatment arms are administered along with a control arm in a trial, dropping the non‐promising treatments at an early stage helps to save the resources and expedite the trial. In such adaptive designs with treatment selection, a common selection rule is to pick the most promising treatment, for example, the treatment with the numerically highest mean response, at the interim stage. However, with only a single treatment selected for final evaluation, this selection rule is often too inflexible. We modified this interim selection rule by introducing a flexible selection margin to judge the acceptable treatment difference. Another treatment could be selected at the interim stage in addition to the empirically best one if the differences of the observed treatment effect between them do not exceed this margin. We considered the study starting with two treatment arms and a control arm. We developed hypothesis testing procedures to assess the selected treatment(s) by taking into account the interim selection process. Compared with the one‐winner selection designs, the modified selection rule makes the design more flexible and practical. Copyright © 2012 John Wiley & Sons, Ltd.
Evaluating accuracy of diagnostic tests with intermediate results in the absence of a gold standard
Authors: Xu Huiping , Black Michael A. , Craig Bruce A.
Published: December 2012

Intermediate test results often occur with diagnostic tests. When assessing diagnostic accuracy, it is important to properly report and account for these results. In the literature, these results are commonly discarded prior to analysis or treated as either a positive or a negative result. Although such adjustments allow sensitivity and specificity to be computed in the standard way, these forced decisions limit the interpretability and usefulness of the results. Estimation of diagnostic accuracy is further complicated when tests are evaluated without a gold standard. Although traditional latent class modeling can be readily applied to analyze these data and account for intermediate results, these models assume that tests are independent conditional on the true disease status, which is rarely valid in practice. We extend both the log‐linear latent class model and the probit latent class model to accommodate the conditional dependence among tests while taking the intermediate results into consideration. We illustrate our methods using a simulation study and a published medical study on the detection of epileptiform activity in the brain. Copyright © 2012 John Wiley & Sons, Ltd.
Robust parametric indirect estimates of the expected cost of a hospital stay with covariates and censored data
Authors: Locatelli Isabella , Marazzi Alfio
Published: December 2012

We consider the problem of estimating the mean hospital cost of stays of a class of patients (e.g., a diagnosis‐related group) as a function of patient characteristics. The statistical analysis is complicated by the asymmetry of the cost distribution, the possibility of censoring on the cost variable, and the occurrence of outliers. These problems have often been treated separately in the literature, and a method offering a joint solution to all of them is still missing. Indirect procedures have been proposed, combining an estimate of the duration distribution with an estimate of the conditional cost for a given duration. We propose a parametric version of this approach, allowing for asymmetry and censoring in the cost distribution and providing a mean cost estimator that is robust in the presence of extreme values. In addition, the new method takes covariate information into account. Copyright © 2012 John Wiley & Sons, Ltd.