bluuebunny/crossref_metadata_2025 huggingface dataset:
Promotion and support of physical activity among cancer survivors: a service provider perspective
Authors: Robertson Lindsay , Richards Rosalina , Egan Richard , Szymlek‐Gay Ewa A.
Published: January 2012

Objective

Cancer survivors are a population group at higher risk of a number of adverse health outcomes. Physical activity during and post‐treatment is beneficial, yet participation in physical activity tends to be low amongst cancer survivors. There is still much to be learnt about how service providers can successfully translate research evidence about the benefits of physical activity for cancer survivors into effective and widely available interventions to support physical activity participation. The aim of this qualitative study is to describe some of the current approaches used by the Cancer Society of New Zealand (CSNZ) to supporting physical activity among survivors and the opportunities and challenges associated with this.

Methods

Participants were Supportive Care Managers and representatives of the CSNZ. A generic qualitative approach included semi‐structured interviews, transcription, member checking and analysis via thematic coding by two of the research team.

Results

Four major themes frame the discussion of the results: (i) existing physical activity programmes and resources for cancer survivors; (ii) gaps and needs in the provision of physical activity programmes for cancer survivors; (iii) barriers, facilitators and preferences in relation to physical activity participation; and (iv) considerations for service providers involved in developing physical activity programmes for cancer survivors.

Conclusions

The implications for future research and for service provision of physical activity programmes for cancer survivors are discussed. Potential strategies to increase physical activity participation among cancer survivors are put forward. Copyright © 2012 John Wiley & Sons, Ltd.
Validity of Measuring the Sit to Walk Movement with an Inertial Sensor
Authors: Kerr A. , Rafferty D. , Dall P. , Muhaidat J.
Published: January 2012

Background

Moving from sitting to walking (STW) is a functional movement that is sufficiently demanding to reveal early mobility problems that may be masked in other tests (Kerr et al., 2007). Research to date has confirmed the inherent difficulty of the STW movement (Magnan et al., 1996); however, the technology used is limited to laboratory settings. Accelerometers may provide a suitable alternative.

Aim

This study aimed to test the concurrent validity of an accelerometer for measuring temporal parameters of the STW movement.

Method

Following ethical approval, 15 healthy participants were instructed to stand up and walk from a chair while a motion analysis system tracked the 3D trajectory of reflective markers located on anatomical landmarks on the trunk and lower limbs. Concurrently, the acceleration signals of both thighs were recorded by two tri‐axial accelerometers (DelSys, Boston, MA, USA). Participants performed three STW movements at self‐selected speeds: slow, normal and fast. Time events for the STW movement (seat off, swing off and swing down) were identified from changes in the marker trajectories, as described in the literature, and points of inflection in the acceleration signals.

Results

Across all speeds, there was an absolute difference of 0.064 seconds ± 0.05 seconds for seat off, 0.072 ± 0.063 seconds for swing off and 0.063 seconds ± 0.039 seconds for swing down. Agreement for the events was excellent with intraclass correlation coefficient values between 0.96 and 0.99. Agreement for the whole movement duration was 0.99.

Conclusions

This study demonstrated excellent agreement between a motion analysis system and inertial sensors for recording time events during the STW movement, suggesting clear potential for this technique. Copyright © 2012 John Wiley & Sons, Ltd.
Thermodynamic basis of selectivity in guide‐target‐mismatched rna interference
Authors: Joseph Thomas T. , Osman Roman
Published: January 2012

Silencing in RNAi is strongly affected by guide‐strand/target‐mRNA mismatches. Target nucleation is thought to occur at positions 2–8 of the guide (“seed region”); successful hybridization in this region is the primary determinant of target‐binding affinity and hence target cleavage. To define a molecular basis for the target sequence selectivity in RNAi, we studied all possible distinct single mismatches in seven positions of the seed region—a total of 21 substitutions. We report results from soft‐core thermodynamic integration simulations to determine changes in targeting binding‐free energies to Argonaute due to single mismatches in the guide strand, which arise during binding of an imperfectly matched target mRNA. In agreement with experiment, most mismatches impair target binding, consistent with a prominent role for binding affinity changes in RNAi sequence selectivity. Individual Argonaute residues located near the mismatched base pair are found to contribute significantly to binding affinity changes. We also use this methodology to analyze the mismatch‐dependent free energy changes for dissociation of a DNA•RNA hybrid from Argonaute, as a model for the escape of miRNAs from the silencing pathway. Several mismatched sequences of the miRNA have increased affinity to Argonaute, implying that some mismatches may reduce the probability for escape. Furthermore, calculations of base‐substitution‐dependent free energy changes for binding ssDNA reveal mild sequence sensitivity as expected for guide strand binding to Argonaute. Our findings give a thermodynamic basis for RNAi target sequence selectivity and suggest that miRNA mismatches may increase silencing effectiveness and thus could be evolutionarily advantageous. Proteins 2012; © 2011 Wiley Periodicals, Inc.
Engineering proteins with enhanced mechanical stability by force‐specific sequence motifs
Authors: Lu Wenzhe , Negi Surendra S. , Oberhauser Andres F. , Braun Werner
Published: January 2012

Use of atomic force microscopy (AFM) has recently led to a better understanding of the molecular mechanisms of the unfolding process by mechanical forces; however, the rational design of novel proteins with specific mechanical strength remains challenging. We have approached this problem from a new perspective that generates linear physical–chemical properties (PCP) motifs from a limited AFM data set. Guided by our linear sequence analysis, we designed and analyzed four new mutants of the titin I1 domain with the goal of increasing the domain's mechanical strength. All four mutants could be cloned and expressed as soluble proteins. AFM data indicate that at least two of the mutants have increased molecular mechanical strength. This observation suggests that the PCP method is useful to graft sequences specific for high mechanical stability to weak proteins to increase their mechanical stability, and represents an additional tool in the design of novel proteins besides steered molecular dynamics calculations, coarse grained simulations, and ϕ‐value analysis of the transition state. Proteins 2012; © 2011 Wiley Periodicals, Inc.
Signaling pathway of a photoactivable Rac1‐GTPase in the early stages
Authors: Peter Emanuel , Dick Bernhard , Baeurle Stephan A.
Published: January 2012

In modern life‐ and medical‐sciences major efforts are currently concentrated on creating artificial photoenzymes, consisting of light‐ oxygen‐voltage‐sensitive (LOV) domains fused to a target enzyme. Such protein constructs possess great potential for controlling the cell metabolism as well as gene function upon light stimulus. This has recently been impressively demonstrated by designing a novel artificial fusion protein, connecting the AsLOV2‐Jα‐photosensor from Avena sativa with the Rac1‐GTPase (AsLOV2‐Jα‐Rac1), and by using it, to control the motility of cancer cells from the HeLa‐line. Although tremendous progress has been achieved on the generation of such protein constructs, a detailed understanding of their signaling pathway after photoexcitation is still in its infancy. Here, we show through computer simulations of the AsLOV2‐Jα‐Rac1‐photoenzyme that the early processes after formation of the Cys450‐FMN‐adduct involve the breakage of a H‐bond between the carbonyl oxygen FMN‐C4O and the amino group of Gln513, followed by a rotational reorientation of its sidechain. This initial event is followed by successive events including β‐sheet tightening and transmission of torsional stress along the Iβ‐sheet, which leads to the disruption of the Jα‐helix from the N‐terminal end. Finally, this process triggers the detachment of the AsLOV2‐Jα‐photosensor from the Rac1‐GTPase, ultimately enabling the activation of Rac1 via binding of the effector protein PAK1. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Evaluation of organically acceptable insecticides as stand‐alone treatments and in rotation for managing yellowmargined leaf beetle, Microtheca ochroloma (Coleoptera: Chrysomelidae), in organic crucifer production
Authors: Balusu Rammohan R , Fadamiro Henry Y
Published: January 2012

BACKGROUND: Yellowmargined leaf beetle, Microtheca ochroloma, is the most damaging pest of organic crucifer crops in the southern United States. Experiments were conducted over four growing seasons (2007–2010) in Alabama to evaluate some botanical and microbial insecticides approved by the Organic Materials Review Institute (OMRI) against M. ochroloma in organically grown crucifer crops. Insecticides evaluated included PyGanic® (pyrethrum), Aza‐Direct® (azadiractin), Entrust® (spinosad), Mycotrol O® (Beauveria bassiana strain GHA) and NOFLY® [Isaria ( = Paecilomyces) fumosoroseus strain FE 9901]. Two experimental organic formulations, Tick‐Ex (Metarhizium anisopliae strain F52) and MBI‐203 (Chromobacterium subtsugae), and one non‐OMRI‐listed formulation, Novodor® (Bacillus thuringiensis subspecies tenebrionis), were also evaluated. The insecticides were applied as stand‐alone treatments at recommended field rates on a weekly schedule. In 2010, some of the treatments were also evaluated in rotation/alternation with Entrust®. Insecticide efficacy was determined by comparing densities of M. ochroloma larvae and adults and crop damage ratings in treated versus untreated turnip plots.

RESULTS: Entrust® consistently performed well in suppressing M. ochroloma adults, larvae and crop damage. PyGanic® was the second best treatment. PyGanic® or NOFLY™ can be applied in rotation with Entrust® for effective management of M. ochroloma.

CONCLUSION: Entrust® applied weekly or in alternation with PyGanic® or NOFLY™ provided acceptable control of M. ochroloma in organic crucifer production. Copyright © 2012 Society of Chemical Industry
Rationale for a natural products approach to herbicide discovery
Authors: Dayan Franck E , Owens Daniel K , Duke Stephen O
Published: January 2012

Weeds continue to evolve resistance to all the known modes of herbicidal action, but no herbicide with a new target site has been commercialized in nearly 20 years. The so‐called ‘new chemistries’ are simply molecules belonging to new chemical classes that have the same mechanisms of action as older herbicides (e.g. the protoporphyrinogen‐oxidase‐inhibiting pyrimidinedione saflufenacil or the very‐long‐chain fatty acid elongase targeting sulfonylisoxazoline herbicide pyroxasulfone). Therefore, the number of tools to manage weeds, and in particular those that can control herbicide‐resistant weeds, is diminishing rapidly. There is an imminent need for truly innovative classes of herbicides that explore chemical spaces and interact with target sites not previously exploited by older active ingredients. This review proposes a rationale for a natural‐products‐centered approach to herbicide discovery that capitalizes on the structural diversity and ingenuity afforded by these biologically active compounds. The natural process of extended‐throughput screening (high number of compounds tested on many potential target sites over long periods of times) that has shaped the evolution of natural products tends to generate molecules tailored to interact with specific target sites. As this review shows, there is generally little overlap between the mode of action of natural and synthetic phytotoxins, and more emphasis should be placed on applying methods that have proved beneficial to the pharmaceutical industry to solve problems in the agrochemical industry. Published 2012 by John Wiley & Sons, Ltd.
Efficacy of two insecticides for protecting loblolly pines (Pinus taeda L.) from subcortical beetles (Coleoptera: Curculionidae and Cerambycidae)
Authors: Burke Jordan L , Hanula James L , Horn Scott , Audley Jackson P , Gandhi Kamal JK
Published: January 2012

BACKGROUND: Tests were conducted on two insecticides (carbaryl and bifenthrin) for excluding subcortical beetles (Coleoptera: Curculionidae and Cerambycidae) from loblolly pine trees (Pinus taeda L.). Two trap designs (single‐ and double‐pane windows) and two trapping heights (1.5 and 4 m) were also evaluated for maximizing beetle catches.

RESULTS: In July 2009, 15 loblolly pine trees were double girdled and were either left unsprayed or sprayed with carbaryl or bifenthrin. A total of 28 473 bark beetles were caught in window traps, including Ips avulsus Eichoff, I. grandicollis (Eichhoff), I. calligraphus (Germar) and Dendroctonus terebrans (Olivier). Both insecticides significantly reduced colonization of the trees by bark and woodboring beetles by 300–400%, with no differences in efficacy observed between the two insecticides. About 59% more I. avulsus were caught in double‐ than in single‐pane window traps, with no differences for any other species. Traps at 4 m caught more I. avulsus and I. grandicollis (290 and 153% respectively), while traps at 1.5 m caught more D. terebrans (215%).

CONCLUSIONS: Either bifenthrin or carbaryl can be used to exclude subcortical beetles from loblolly pine trees. Trapping data reflect known vertical partitioning on the bole by these insects. Double‐pane traps were slightly more effective than single‐pane traps in catching subcortical beetles. Copyright © 2012 Society of Chemical Industry
Non‐target‐site‐based resistance to ALS‐inhibiting herbicides in six Bromus rigidus populations from Western Australian cropping fields
Authors: Owen Mechelle J , Goggin Danica E , Powles Stephen B
Published: January 2012

BACKGROUND: Bromus rigidus is a common weed species that has increased in cropping fields owing to limited control options. During a random field survey in Western Australia, six B. rigidus populations that had survived in‐crop weed control programmes were collected. The study aimed to determine the resistance profile of these six populations.

RESULTS: Based on dose–response studies, all six B. rigidus populations had a low‐level resistance to sulfosulfuron and sulfometuron (both sulfonylurea herbicides) while remaining susceptible to herbicides with other modes of action. ALS in vitro activity assays revealed no differences in enzyme sensitivity between susceptible and resistant populations, while the use of malathion (a cytochrome P450 inhibitor) in combination with sulfosulfuron caused the resistant populations to behave like the susceptible population.

CONCLUSION: This study established that these six B. rigidus populations have a low‐level resistance to the ALS‐inhibiting sulfonylurea herbicides, but are able to be controlled by other herbicide modes of action. The low‐level, malathion‐reversible resistance, together with a sensitive ALS, strongly suggest that a non‐target‐site enhanced metabolism is the mechanism of resistance. Copyright © 2012 Society of Chemical Industry
Effect of indium on the conductivity of poly‐crystalline GaN grown on high purity fused silica
Authors: Keller Stacia , Lu Jing , Mishra Umesh K. , DenBaars Steven P. , Speck James S.
Published: January 2012

A significant resistivity reduction was observed for GaN:Si films grown on high purity fused silica by metal organic vapour deposition when an InGaN:Si sacrificial layer was inserted beneath or within the GaN:Si layers. Thereby at least part of the GaN:Si layer on top of the sacrificial layer was grown at high temperature. Using this technique, a film resistance of 0.8 Ω cm was obtained, compared to a resistance of 60 Ω cm measured for the same layer stack without InGaN sacrificial layer.
Green light‐emitting diodes fabricated on semipolar (11–22) GaN on r‐plane patterned sapphire substrate
Authors: Okada Narihito , Uchida Katsumi , Miyoshi Seita , Tadatomo Kazuyuki
Published: January 2012

We have succeeded in the growth of a high‐quality semipolar (11–22) GaN layer on an r‐plane patterned sapphire substrate (r‐PSS). In this study, we report on green‐light‐emitting diodes (LEDs) fabricated on the (11–22) GaN layer on the r‐PSS. The optical property of (11–22) MQWs on the r‐PSS improved from that of the same MQWs on an m‐plane sapphire substrate. The green light emission from the LED on the r‐PSS was confirmed, which exhibited scattered light emission. The effect of the r‐PSS on the improvement of light extraction was evaluated by ray tracing simulation, which is higher than that of a conventional LED on a c‐PSS. This improvement is derived from the air void structure in the LED fabricated on the r‐PSS. It was also confirmed that the LED had a small blue shift compared with that on the conventional green LED, and that the quantum confined Stark effect can be reduced using the semipolar (11–22) GaN layer on the r‐PSS.
Study of defects and lifetime of green InGaN laser diodes
Authors: Strauss Uwe , Lermer Teresa , Müller Jens , Hager Thomas , Brüderl Georg , Avramescu Adrian , Lell Alfred , Eichler Christoph
Published: January 2012

InGaN quantum wells for direct green lasers with indium concentrations of about 30% are studied in respect to defect structure and influence of defects on device lifetime. A new test structure enables us to determine strain relaxation in In‐rich layers by X‐ray diffraction even at typical well thicknesses of few nanometers. We show that there is a high risk to generate screw and edge dislocations in the In‐rich quantum wells in non‐optimized structures as verified by transition electron microscopy. Such defects strongly influence the device lifetimes of green lasers. Non‐optimized devices have a drop of output power on a time scale of 100 h. The threshold current increases proportional to the square root of time. Additionally, a linear correlation of slope efficiency versus one over laser threshold current is observed. The degradation process is explained as reduced carrier injection efficiencies related to the generation of additional charged defects in the active layers. Optimized active layers already enable stable operation over a period of more than 1000 h at 50 mW constant power at 517 nm emission wavelength with an extrapolated increase of operation current by <30% within this time.
Influence of film thickness on structural and optical properties of ZnS thin films obtained by SILAR method and analysis of Zn/ZnS/n‐GaAs/In sandwich structure
Authors: Özakın Oğuzhan , Güzeldir Betül , Yıldırım M. Ali , Sağlam Mustafa , Ateş Aytunç
Published: January 2012

ZnS thin films were deposited on glass substrates using SILAR method at room temperature and ambient pressure. The relationship between refractive index and energy bandgap was investigated. The film thickness effect on the structural, morphological and optical properties of ZnS thin films was investigated. The crystalline and surface properties of the films improved with increasing film thickness. The energy bandgap values changed from 3.87 to 3.58 eV with increasing film thickness. The refractive index (n), high frequency dielectric constant (ε∞) values were calculated by using the energy bandgap values as a function of the film thickness. Also, ZnS thin film was deposited directly on n‐GaAs substrate for obtaining the Zn/ZnS/n‐GaAs/In sandwich structure at room temperature. The sandwich structure demonstrated clearly rectifying behaviour by the current–voltage (I–V) curves at room temperature. From I–V characteristics n and Φb values were calculated as 1.894 and 0.632 eV at room temperature, respectively.
Carbon‐doped p‐type (0001) plane AlGaN (Al = 6–55%) with high hole density
Authors: Kawanishi Hideo , Tomizawa Tatsuya
Published: January 2012

In this paper, promising experimental results for the p‐type electrical properties of carbon‐doped (C‐doped) AlGaN are discussed. P‐type conductivity was experimentally achieved in C‐doped (0001) plane AlGaN layers with from a small amount to 55% solid Al composition, but not in (0001) plane GaN. The maximum free hole density (determined by van der Pauw geometry‐Hall effect measurement) achieved for an AlGaN layer with 10% solid Al composition was p = 3.2 × 1018 cm−3. The maximum net ionized acceptor densities (NIAD), $N_{{\rm A}}^{- } - N_{{\rm D}}^{ + } $, which were determined by capacitance–voltage measurement, for AlGaN with 6, 10, 27, and 55% solid Al compositions, were all in the range of (6–7) × 1018 cm−3. Moreover, the electrical activity of the carbon acceptors was estimated to be 55–71% from the NIAD and secondary‐ion microprobe mass spectrometry analysis data on the carbon concentration. A p–n junction was also fabricated using the C‐doped p‐type AlGaN.
Electrospray Ionization‐Mass Spectrometry Analysis Reveals Migration of Cyclic Lactide Oligomers from Polylactide Packaging in Contact with Ethanolic Food Simulant
Authors: Bor Yasemin , Alin Jonas , Hakkarainen Minna
Published: January 2012

Electrospray ionization‐mass spectrometry analysis revealed rapid migration of cyclic oligomers from polylactide (PLA) packaging when stored in contact with 96% ethanol. The mass losses in contact with water, 3% acetic acid, 10% ethanol and isooctane were 3 to 5 times smaller and no migration of cyclic oligomers was observed. The presence of cyclic oligomers in the original PLA films and their solubility in ethanol, thus, explains the rapid mass loss for PLA in contact with ethanolic food simulant. On prolonged ageing no further mass loss was observed in 96% ethanol, whereas mass loss in aqueous food simulants increased because of hydrolysis of PLA matrix or the cyclic oligomers to water‐soluble linear products. The mass losses were generally somewhat smaller for the stereocomplex material compared with the poly‐l‐lactide materials. Similar trend was observed for solvent uptakes, which is easily explained by the higher degree of crystallinity and stronger secondary interactions in the stereocomplex material. The use of ethanol as a fatty food simulant for PLA materials could, thus, lead to overestimation of the overall migration values. Copyright © 2012 John Wiley & Sons, Ltd.
Hydrogel Nanoparticles with Covalently Linked Coomassie Blue for Brain Tumor Delineation Visible to the Surgeon
Authors: Nie Guochao , Hah Hoe Jin , Kim Gwangseong , Lee Yong‐Eun Koo , Qin Ming , Ratani Tanvi S. , Fotiadis Panagiotis , Miller Amber , Kochi Akiko , Gao Di , Chen Thomas , Orringer Daniel A. , Sagher Oren , Philbert Martin A. , Kopelman Raoul
Published: January 2012

Delineation of tumor margins is a critical and challenging objective during brain cancer surgery. A tumor‐targeting deep‐blue nanoparticle‐based visible contrast agent is described, which, for the first time, offers in vivo tumor‐specific visible color staining. This technology thus enables color‐guided tumor resection in real time, with no need for extra equipment or special lighting conditions. The visual contrast agent consists of polyacrylamide nanoparticles covalently linked to Coomassie Blue molecules (for nonleachable blue color contrast), which are surface‐conjugated with polyethylene glycol and F3 peptides for efficient in vivo circulation and tumor targeting, respectively.
Engineered Redox‐Responsive PEG Detachment Mechanism in PEGylated Nano‐Graphene Oxide for Intracellular Drug Delivery
Authors: Wen Huiyun , Dong Chunyan , Dong Haiqing , Shen Aijun , Xia Wenjuan , Cai Xiaojun , Song Yanyan , Li Xuequan , Li Yongyong , Shi Donglu
Published: January 2012

In biomedical applications, polyethylene glycol (PEG) functionalization has been a major approach to modify nanocarriers such as nano‐graphene oxide for particular biological requirements. However, incorporation of a PEG shell poses a significant diffusion barrier that adversely affects the release of the loaded drugs. This study addresses this critical issue by employing a redox‐responsive PEG detachment mechanism. A PEGylated nano‐graphene oxide (NGO‐SS‐mPEG) with redox‐responsive detachable PEG shell is developed that can rapidly release an encapsulated payload at tumor‐relevant glutathione (GSH) levels. The PEG shell grafted onto NGO sheets gives the nanocomposite high physiological solubility and stability in circulation. It can selectively detach from NGO upon intracellular GSH stimulation. The surface‐engineered structures are shown to accelerate the release of doxorubicin hydrochloride (DXR) from NGO‐SS‐mPEG 1.55 times faster than in the absence of GSH. Confocal microscopy shows clear evidence of NGO‐SS‐mPEG endocytosis in HeLa cells, mainly accumulated in cytoplasm. Furthermore, upon internalization of DXR‐loaded NGO with a disulfide‐linked PEG shell into HeLa cells, DXR is effectively released in the presence of an elevated GSH reducing environment, as observed in confocal microscopy and flow cytometric experiments. Importantly, inhibition of cell proliferation is directly correlated with increased intracellular GSH concentrations due to rapid DXR release.
Tuning Ratios, Densities, and Supramolecular Spacing in Bifunctional DNA‐Modified Gold Nanoparticles
Authors: Díaz Julián A. , Grewer David M. , Gibbs‐Davis Julianne M.
Published: January 2012

Methods for combining multiple functions into well‐defined nanomaterials are still lacking, despite their need in nanomedicine and within the broader field of nanotechnology. Here several strategies for controlling the amount and the ratio of combinations of labeled DNA on 13‐nm gold nanoparticles using self‐assembly of thiolated DNA and/or DNA‐directed assembly are explored. It is found that the self‐assembly of mixtures of fluorescently labeled DNA can lead to a higher amount of labeled DNA per particle; however, the ratio of fluorophores on the nanoparticles differs greatly from that in the self‐assembly solution. In contrast, when fluorescently labeled DNA are hybridized to DNA‐modified gold nanoparticles, the fluorophore ratio on the nanoparticles is much closer to their ratio in solution. The use of bifunctional DNA‐doublers in self‐assembly and DNA‐directed assembly is also explored to increase the complexity of these materials and control their composition. Finally, tuning the distance between the labels from 2.9 to 5.4 nm was achieved using different hybridized DNA clamp complexes. Fluorescent results suggest that assembling these clamps on nanoparticle surfaces may be possible, although the resulting label spacing could not be quantified.
Thermoplastic starch modified with polyurethane microparticles: Effects of hydrophilicity of polyurethane prepolymer
Authors: Chen Xiaoxia , Zhang Yu , Zhang Pingping , Fan Bingbing , Wu Qiangxian
Published: January 2012

It is important to chemically modify starch in an effective way. In this study, a series of polyurethane prepolymers (PUP) using 2,2‐dimethylol propionic acid (DMPA) as hydrophilic chain extender was synthesized and then used to modify starch by intensive mixing to obtain modified thermoplastic starch (TPS). The structure and properties of the modified TPS were investigated. The results showed that the elongation at break of the modified TPS increased from 5.4 to 9.8% with the content of PUP in modified TPS increasing from 10 to 20%, suggesting the PUP played an important role in the enhancement of the flexibility of the modified TPS sheet. The reaction ratio of PUP used for preparing the modified TPS was 98.5 ± 0.03%, indicating the modification was conducted efficiently because the multifunctional groups of polyurethane microparticles dramatically improved the reaction probability of the PUP modifier. The modified TPS prepared with PUP by adding DMPA showed increasing viscosity and decreasing contact angle due to the hydrophilicity of DMPA.
Role of MicroRNAs 99b, 181a, and 181b in the Differentiation of Human Embryonic Stem Cells to Vascular Endothelial Cells
Authors: Kane Nicole M. , Howard Lynsey , Descamps Betty , Meloni Marco , McClure John , Lu Ruifang , McCahill Angela , Breen Christopher , Mackenzie Ruth M. , Delles Christian , Mountford Joanne C. , Milligan Graeme , Emanueli Costanza , Baker Andrew H.
Published: January 2012

MicroRNAs (miRNAs) are short noncoding RNAs, which post-transcriptionally regulate gene expression. miRNAs are transcribed as precursors and matured to active forms by a series of enzymes, including Dicer. miRNAs are important in governing cell differentiation, development, and disease. We have recently developed a feeder- and serum-free protocol for direct derivation of endothelial cells (ECs) from human embryonic stem cells (hESCs) and provided evidence of increases in angiogenesis-associated miRNAs (miR-126 and -210) during the process. However, the functional role of miRNAs in hESC differentiation to vascular EC remains to be fully interrogated. Here, we show that the reduction of miRNA maturation induced by Dicer knockdown suppressed hES-EC differentiation. A miRNA microarray was performed to quantify hES-EC miRNA profiles during defined stages of endothelial differentiation. miR-99b, -181a, and -181b were identified as increasing in a time- and differentiation-dependent manner to peak in mature hESC-ECs and adult ECs. Augmentation of miR-99b, -181a, and -181b levels by lentiviral-mediated transfer potentiated the mRNA and protein expression of EC-specific markers, Pecam1 and VE Cadherin, increased nitric oxide production, and improved hES-EC-induced therapeutic neovascularization in vivo. Conversely, knockdown did not impact endothelial differentiation. Our results suggest that miR-99b, -181a, and -181b comprise a component of an endothelial-miRNA signature and are capable of potentiating EC differentiation from pluripotent hESCs.

Disclosure of potential conflicts of interest is found at the end of this article.
Transcription Factor TCF4 Maintains the Properties of Human Corneal Epithelial Stem Cells
Authors: Lu Rong , Qu Yangluowa , Ge Jian , Zhang Lili , Su Zhitao , Pflugfelder Stephen C. , Li De-Quan
Published: January 2012

TCF4, a key transcription factor of Wnt signaling system, has been recently found to be essential for maintaining stem cells. However, its signaling pathway is not well elucidated. This study was to explore the functional roles and signaling pathway of TCF4 in maintaining adult stem cell properties using human corneal epithelial stem cells as a model. With immunofluorescent staining and real-time polymerase chain reaction, we observed that TCF4 was exclusively expressed in the basal layer of human limbal epithelium where corneal epithelial stem cells reside. TCF4 was found to be well colocalized with ABCG2 and p63, two recognized epithelial stem/progenitor cell markers. Using in vitro culture models of primary human corneal epithelial cells, we revealed that TCF4 mRNA and protein were upregulated by cells in exponential growth stage, and RNA interference by small interfering RNA-TCF4 (10-50 nM) transfection blocked TCF4 signaling and suppressed cell proliferation as measured by WST-1 assay. TCF4 silence was found to be accompanied by downregulated proliferation-associated factors p63 and survivin, as well as upregulated cyclin-dependent kinase inhibitor 1C (p57). By creating a wound healing model in vitro, we identified upregulation and activation of β-catenin/TCF4 with their protein translocation from cytoplasm to nuclei, as evaluated by reverse transcription-quantitative real-time polymerase chain reaction, immunostaining, and Western blotting. Upregulated p63/survivin and downregulated p57 were further identified to be TCF4 downstream molecules that promote cell migration and proliferation in wound healing process. These findings demonstrate that transcription factor TCF4 plays an important role in determining or maintaining the phenotype and functional properties of human corneal epithelial stem cells.

Disclosure of potential conflicts of interest is found at the end of this article.
miR-290 Cluster Modulates Pluripotency by Repressing Canonical NF-κB Signaling
Authors: Lüningschrör Patrick , Stöcker Benedikt , Kaltschmidt Barbara , Kaltschmidt Christian
Published: January 2012

Embryonic stem cell (ESC)-specific microRNAs (miRNAs) play a critical role in the maintenance of pluripotency and self-renewal but the complete network between these miRNAs and their broad range of target genes still remains elusive. Here we demonstrate that miR-290 cluster, the most abundant miRNA family in ESCs, targets the NF-κB subunit p65 (also known as RelA) by repressing its translation. Forced expression of p65 causes loss of pluripotency, promotes differentiation of ESCs, and leads to an epithelial to mesenchymal transition. These data define p65 as a novel target gene of miR-290 cluster and provide new insight into the function of ESC-specific miRNAs.

Disclosure of potential conflicts of interest is found at the end of this article.
Can dynamic visualizations improve middle school students' understanding of energy in photosynthesis?
Authors: Ryoo Kihyun , Linn Marcia C.
Published: January 2012

Dynamic visualizations have the potential to make abstract scientific phenomena more accessible and visible to students, but they can also be confusing and difficult to comprehend. This research investigates how dynamic visualizations, compared to static illustrations, can support middle school students in developing an integrated understanding of energy in photosynthesis. Two hundred 7th‐grade students were randomly assigned to either a dynamic or a static condition and completed a web‐based inquiry unit that encourages students to make connections among energy concepts in photosynthesis. While working on the inquiry unit, students in the dynamic condition interacted with a dynamic visualization of energy transformation, whereas students in the static condition interacted with a series of static illustrations of the same concept. The results showed that students in both conditions added new, scientific ideas about energy transformation and developed a more coherent understanding of energy in photosynthesis. However, when comparing the two conditions, we found a significant advantage of dynamic visualization over static illustrations. Students in the dynamic condition were significantly more successful in articulating the process of energy transformation in the context of chemical reactions during photosynthesis. Students in the dynamic condition also demonstrated a more integrated understanding of energy in photosynthesis by linking their ideas about energy transformation to other energy ideas and observable phenomena of photosynthesis than those students in the static condition. This study, consistent with other research, shows that dynamic visualizations can more effectively improve students' understanding of abstract concepts of molecular processes than static illustrations. The results of this study also suggest that with appropriate instructional support, such as making predictions and distinguishing among ideas, both dynamic visualizations and static illustrations can benefit students. This study underscores the importance of curriculum design in ensuring that dynamic visualizations add value to science instructional materials. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 218–243, 2012
Nearest‐neighbor methods
Authors: Sutton Clifton
Published: January 2012

Nearest‐neighbor classification is a simple and popular method for supervised classification. The basic method is to classify a query point as being of a certain class if of the k‐nearest neighbors of the query point, more of them belong to this class than to any other class. Variations of the basic method include weighted nearest‐neighbor methods and adaptive nearest‐neighbor methods (which allow some variables to have greater influence than other variables). WIREs Comput Stat 2012, 4:307–309. doi: 10.1002/wics.1195

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Clustering and Classification

Statistical Learning and Exploratory Methods of the Data Sciences > Pattern Recognition
Fluorescent Properties of three Zinc(II) Coordination Polymers derived from Flexible N‐(4/3‐Carboxyphenyl)iminodiacetic Acids
Authors: Chai Xiao‐Chuan , Zhao Yan‐Fei , Gong Qiao‐Juan , Liang Yong‐Ping , Zhang Han‐Hui , Chen Yi‐Ping
Published: January 2012

Three polymers [Zn2(p‐CPIDA)(OH)]n (1), [Zn2(p‐HCPIDA)2(bipy)(H2O)4]·2H2O (2), and [Zn(m‐HCPIDA)(bipy)]n (3) [p/m‐H3CPIDA = N‐(4/3‐carboxyphenyl) iminodiacetic acid, bipy = 4, 4′‐bipyridine] were hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction, X‐ray powder diffraction patterns (XPRD), FTIR spectroscopy, and fluorescence analyses. Compound 1 displays an interesting three‐dimensional framework consisting of novel paddle wheel Zn8O10C2 units, which are further linked by p‐CPIDA3– ligands with versatile coordination modes. In 2, the structural motifs formed by terminal p‐HCPIDA2– ligands and ZnII ions are bridged by ancillary bipy to give a zero‐dimensional Z‐shaped dimer. Compound 3 has an infinite zigzag chain linked by bipy, in which terminal m‐HCPIDA2– ligands alternately run along the chain like flags. Compounds 2 and 3 are further connected by hydrogen bonding and π···π stacking interactions to result in 3D supramolecular frameworks. Moreover, compounds 1–3 exhibit intense solid state fluorescent emissions at room temperature.
Syntheses, Crystal Structures, and Magnetic Properties of Three Transition Metal Complexes Based on a Flexible ­Dipyridyl Ligand and Oxalate
Authors: Cui Zhi‐Hua , Wang Si‐Si , Wang Xiu‐Guang , Gao Dong‐Zhao , Sun Ya‐Qiu , Zhang Guo‐Ying , Xu Yan‐Yan
Published: January 2012

Three new complexes [Cu(Hbpma)(ox)Cl]2·8H2O (1), {[Co2(bpma)(ox)2(H2O)2]·6H2O}n (2), and {[Zn2(bpma)(ox)2(H2O)2]·6H2O}n (3) (bpma = N,N′‐bis(3‐pyridylmethyl)amine and ox = oxalate) were synthesized and structurally characterized by single‐crystal X‐ray diffraction. Complex 1 is a bpma‐bridged dinuclear CuII compound, whereas the oxalate only acts as terminal ligand by bidentate chelating mode. Complexes 2 and 3 are isomorphs found to be one‐dimensional coordination polymers bridged by both bpma and ox ligands. The conformation of bpma ligand has a transformation from trans‐gauche mode in complex 1 to trans‐trans one in complexes 2 and 3. The magnetic property of complex 2 shows the occurrence of antiferromagnetic interactions between two adjacent CoII ions.
Hafnium Trialkyls Stabilized by Bulky, Electron‐Rich Aminopyridinates
Authors: Hafeez Muhammad , Kretschmer Winfried P. , Kempe Rhett
Published: January 2012

A series of hafnium aminopyridinates were synthesized and spectroscopically analyzed. In addition, selected examples of these hafnium complexes were characterized by X‐ray single crystal structure analysis. The aminopyridinato ligands used here carry an additional dialkylamine substituent to enhance the electron donating ability of the ligands. Structural data and low temperature NMR spectroscopic investigations are indicative of the increased donating ability of the ligands. Ethylene polymerization studies revealed a rather low catalytic activity most likely due to catalyst instability. Details of the deactivation reaction were investigated by NMR spectroscopy.
2Mg(OH)2·MgCl2·2H2O and 2Mg(OH)2·MgCl2·4H2O, Two High Temperature Phases of the Magnesia Cement System
Authors: Dinnebier Robert E. , Oestreich Melanie , Bette Sebastian , Freyer Daniela
Published: January 2012

In the course of investigations relating to magnesia cement the basic magnesium salt hydrates 2Mg(OH)2·MgCl2·2H2O (2‐1‐2 phase) and 2Mg(OH)2·MgCl2·4H2O (2‐1‐4 phase) were found as stable phases in the system MgO‐MgCl2‐H2O at a temperature of T = 120 °C and were characterized by thermal analysis, Raman spectroscopy and X‐ray powder diffraction. The crystal structures of the 2‐1‐2 and 2‐1‐4 phases were determined from high resolution laboratory X‐ray powder diffraction data.Both phases crystallize in space group C2/m with Z = 2 (2‐1‐2: a = 15.3285(3) Å, b = 3.2208(5) Å, c = 8.1096(2) Å, β = 91.99(1)°, V = 400.13(2) Å3; 2‐1‐4: a = 15.1264 Å, b = 3.1715(2) Å, c = 10.5230(1) Å, β = 101.55(1)°, V = 494.60(1) Å3). The main building unit of both crystal structures is made up by infinite triple chains of edge‐linked distorted MgO6 octahedra. In case of the 2‐1‐4 phase, the parallel stacks are in addition separated by interstitial one dimensional zig‐zag chains of disordered Cl– ions and H2O molecules.
Intellectual and neurological functioning in Morquio syndrome (MPS IVa)
Authors: Davison J. E. , Kearney S. , Horton J. , Foster K. , Peet A. C. , Hendriksz C. J.
Published: January 2012

Mucopolysaccharidosis type IVa (MPS IVa, Morquio syndrome OMIM #253000) is a lysosomal storage disease caused by deficiency in N‐acetylgalactosamine‐6‐sulfatase (GALNS, EC 3.1.6.4; encoded by GALNS gene at 16q24.3). Unlike other MPS disorders involving excessive heparan and dermatan sulfate, Morquio syndrome has not been associated with neurological involvement nor with intellectual impairment as this disorder of keratan sulfate has been described as a purely visceral and skeletal disorder. Neurocognitive assessment was undertaken of MPS IVa patients with age appropriate intellectual tests as well as a Child Behaviour Checklist as part of clinical follow up. Available neuroimaging studies (MRI and MR spectroscopy) were reviewed. Whilst more than half of the overall IQ scores fell in the average range, scores for 3/8 children fell below average. A number of behavioural problems were highlighted, including anxiety/depression, attention and somatic complaints. Subtle neuroimaging abnormalities were demonstrated in over half of the children. These findings present a challenge to existing assumptions about the nature of Morquio A syndrome. A hypothesis regarding the potential role of calcium signalling is explored.
Decreased functional brain connectivity in individuals with early‐treated phenylketonuria: evidence from resting state fMRI
Authors: Christ Shawn E. , Moffitt Amanda J. , Peck Dawn , White Desirée A. , Hilgard Joseph
Published: January 2012

Previous histological and neuroimaging studies have documented structural abnormalities in the white matter of the brain in individuals with early‐treated phenylketonuria (ETPKU). It remains unclear, however, the extent to which the function of the brain's interconnections are impacted by this condition. Presently, we utilized functional magnetic resonance imaging (fMRI) to evaluate the synchronization of neural signals (i.e., functional connectivity) among brain regions comprising the default mode network (DMN) in a sample of 11 individuals with ETPKU and 11 age‐ and gender‐matched neurologically intact controls. The DMN is a group of interconnected brain regions that are known to be generally more active during rest than during task performance. Data analysis revealed decreased functional connectivity among DMN regions for the ETPKU group compared with the control group. Within the PKU group, we also found a significant relationship between blood phenylalanine (phe) levels and the functional connectivity between select regions of the DMN. In conjunction with findings from another recent fMRI study (Christ, Moffitt et al. 2010), the present results suggest that ETPKU‐related deficiencies in functional connectivity are pervasive. The current findings also provide initial evidence that the extent of such impairment may be moderated in part by blood phe levels.
Hyperinsulinaemic hypoglycaemia: genetic mechanisms, diagnosis and management
Authors: Senniappan Senthil , Shanti Balasubramaniam , James Chela , Hussain Khalid
Published: January 2012

Hyperinsulinaemic hypoglycaemia (HH) is due to the unregulated secretion of insulin from pancreatic β‐cells. A rapid diagnosis and appropriate management of these patients is essential to prevent the potentially associated complications like epilepsy, cerebral palsy and neurological impairment. The molecular basis of HH involves defects in key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, HNF4A and UCP2) which regulate insulin secretion. The most severe forms of HH are due to loss of function mutations in ABCC8/KCNJ11 which encode the SUR1 and KIR6.2 components respectively of the pancreatic β‐cell KATP channel. At a histological level there are two major forms (diffuse and focal) each with a different genetic aetiology. The diffuse form is inherited in an autosomal recessive (or dominant) manner whereas the focal form is sporadic in inheritance and is localised to a small region of the pancreas. The focal form can now be accurately localised pre‐operatively using a specialised positron emission tomography scan with the isotope Fluroine‐18L‐3, 4‐dihydroxyphenyalanine (18F‐DOPA‐PET). Focal lesionectomy can provide cure from the hypoglycaemia. However the diffuse form is managed medically or by near total pancreatectomy (with high risk of diabetes mellitus). Recent advances in molecular genetics, imaging with 18F‐DOPA‐PET/CT and novel surgical techniques have changed the clinical approach to patients with HH.
Landschaftsverständnisse in der Landschaftsplanung. Eine semantische Analyse der Verwendung des Wortes „Landschaft“ in kommunalen Landschaftsplänen
Authors: Wojtkiewicz Wera , Heiland Stefan
Published: January 2012

The meaning ascribed to the concept of “landscape” and the idea about how “landscape” is constituted, is a basis for setting up goals and measures concerning all natural assets in landscape plans, as e.g. soil, water or landscape scenery. Current research does not sufficiently address the question of how landscape plans refer to the concept of landscape and which ideal types of landscapes determine planning processes. This paper will shed light on the ideas about the use and shape of landscape, which are conveyed through local landscape plans. Therewith we are aiming to determine the role that landscape planning plays for the social construction of landscape. The research pursues a hermeneutic approach and is conducted by means of a qualitative content analysis of municipal landscape plans created between 1993 and 2010 in various regions of Germany.

The semantic analysis of the word landscape allows statements on ideas of how “landscape” should look like. This image equates to a narrow notion of landscape, implying that mainly areas characterized by traditional, peasant cultivation are interpreted as “landscape”. The identified notion of landscape is orientated on conservation rather than development. The current development of landscape and resulting imprint on an area is rarely being taken into account in a positive manner.