bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the biocomposites with poly(ethylene glycol) dimethacrylate and surfaced‐grafted hydroxyapatite nanoparticles
Authors: Li Haibo , Fu Yi , Niu Rui , Zhou Ziyou , Nie Jun , Yang Dongzhi
Published: May 2012

In composites of hydroxyapatite (HA) nanoparticles with a polymer matrix, the aggregation of nanoparticles would induce structural defects. In order to improve the dispersibility of HA nanoparticles in poly(ethylene glycol) dimethacrylate (PEGDMA) matrix and enhance mechanical properties of the HA/PEGDMA composite as potential bone substitute material, surface‐grafted HA nanoparticles with poly(ethylene glycol) monomethacrylate (PEGMA) were prepared, and crosslinked with PEGDMA under UV light to form a composite. The structure of HA‐g‐PEGMA was characterized by X‐ray diffraction (XRD) and thermal gravimetric analysis (TGA). The dispersibility of HA‐g‐PEGMA nanoparticles in poly(PEGDMA) was evaluated by SEM. The mechanical properties of the composites were investigated by compressive test. The dispersibility of HA‐g‐PEGMA nanoparticles in poly(PEGDMA) matrix was better than the bare HA. At a 1 wt % content of loading, the strength of composites increased by 14%, and the modulus increased by 9%. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Mechanical and chemical stability of injection‐molded microcantilevers used for sensing
Authors: Urwyler Prabitha , Pascual Alfons , Kristiansen Per Magnus , Gobrecht Jens , Müller Bert , Schift Helmut
Published: May 2012

Ultraviolet‐ozone treatment is used as a standard surface cleaning procedure for removal of molecular organic contamination from analytical and sensing devices. Here, it is applied for injection‐molded polymer microcantilevers before characterization and sensing experiments. This article examines the effects of the surface cleaning process using commercial equipment, in particular on the performance and mechanical properties of the cantilevers. It can be shown that the first chemical aging process essentially consist of the cross linking of the polymer chains together with a physical aging of the material. For longer exposure, the expected thermo‐oxidative formation of carbonyl groups sets in and an exposure dependent chemical degradation can be detected. A process time of 20 min was found suitable as a trade‐off between cleaning and stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
A study on thermal behavior of a poly(VDF‐CTFE) copolymers binder for high energy materials
Authors: Singh Arjun , Soni P. K. , Shekharam T. , Srivastava Alok
Published: May 2012

This article describes a study on thermal behavior of poly(vinylidene fluoride‐chlorotrifluoroetheylene) [poly(VDF‐CTFE)] copolymers as polymeric binders of specific interest for high energy materials (HEMs) composites by thermal analytical techniques. The non‐isothermal thermogravimetry (TG) for poly (VDF‐CTFE) copolymers was recorded in air and N2 atmospheres. The results of TG thermograms show that poly(VDF‐CTFE) copolymers get degrade at lower temperature when in air than in N2 atmosphere. In the derivative curve, there was single maximum degradation peak (Tmax) indicating one‐stage degradation of poly(VDF‐CTFE) copolymers for all the samples. The other thermal properties such as glass transition temperature (Tg) and degradation temperature (Td) for poly(VDF‐CTFE) copolymers were measured by employing differential scanning calorimeter (DSC) technique. The kinetic parameters related to thermal degradation of poly(VDF‐CTFE) copolymers were investigated through non‐isothermal Kissinger kinetic method using DSC method. The activation energies for thermal degradation of poly(VDF‐CTFE) copolymers were found in a range of 218–278 kJ/mol. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
New amphiphilic sulfonic acid dopant‐cum‐templates for diverse conducting polyaniline nanomaterials
Authors: Shinde Shekhar D. , Jayakannan M.
Published: May 2012

We report new structurally identical polar head amphiphilic sulfonic acids as molecular templates to study the role of the polymerization routes on the solid state properties of polyaniline nanomaterials. Three long chain substituted phenols such as 3‐pentadecylphenol, renewable resource‐cardanol, and nonyl phenol are reacted with sultones to make new long tail amphiphiles. The amphiphilic molecules self‐organized as 4–6 nm tiny micelles in water which were employed as templates for polymerization. Emulsion, dispersion, and interfacial polymerization of aniline along with these new amphiphiles produced well‐defined polyaniline nanofibers, nanotapes, and nanospheres. Electron microscopic analysis revealed that the dopant structure and polymerization routes determine the morphology of the polyaniline nanomaterials. Absorbance studies revealed that the samples produced via interfacial route showed expanded polymer chain conformation as a result of unidirectional growth of the chains in the aqueous‐organic interface. Emulsion and dispersion route samples were produced in coil‐like chain conformation. Powder X‐ray analysis confirmed that the expanded conformation in the polyaniline backbone enhances the high solid state ordering, high percent crystallinity, and larger crystallite size compared to that of the samples with coil‐like conformation. Highly ordered interfacial route samples showed conductivity three orders of magnitude higher than that of the weakly packed polyaniline nanomaterials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and characterization of the 47‐residue heterodimeric antimicrobial peptide distinctin, featuring directed disulfide bridge formation
Authors: Mullen Daniel G. , Verardi Raffaello , Porcelli Fernando , Scaloni Andrea , Barany George , Veglia Gianluigi
Published: May 2012

Distinctin, a 47‐residue heterodimeric peptide with potent antimicrobial activity, comprises two monomeric units linked covalently by a disulfide bond between Cys19 from the 22‐residue A chain and Cys23 from the 25‐residue B chain. Previous synthetic strategies involved assemblies of the two individual chains, followed by their co‐oxidation to form the connecting disulfide bridge, and resulted in a mixture of three species: two homodimers and one heterodimer. Here, we report synthesis of exclusively heterodimeric distinctin, using recently developed tactics for directed disulfide bridge formation. Material prepared this way was characterized and found to be suitable for more detailed structural studies. © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 479–484, 2012.
Autologous reconstruction of massive enteroatmospheric fistulation with a pedicled subtotal lateral thigh flap
Authors: Lambe G , Russell C , West C , Kalaiselvan R , Slade D A J , Anderson I D , Watson J S , Carlson G L
Published: May 2012

Background

Reconstruction of massive contaminated abdominal wall defects associated with enteroatmospheric fistulation represents a technical challenge. An effective technique that allows closure of intestinal fistulas and reconstruction of the abdominal wall, with a good functional and cosmetic result, has yet to be described. The present study is a retrospective review of simultaneous reconstruction of extensive gastrointestinal tract fistulation and large full-thickness abdominal wall defects, using a novel pedicled subtotal thigh flap.

Methods

The flap, based on branches of the lateral circumflex femoral artery, was used to reconstruct the abdominal wall in six patients who were dependent on artificial nutritional support, with a median (range) of 4·5 (3–23) separate intestinal fistulas, within open abdominal wounds with a surface area of 564·5 (204–792) cm2. Intestinal reconstruction was staged, with delayed closure of a loop jejunostomy. Median follow-up was 93·5 (10–174) weeks.

Results

Successful healing occurred in all patients, with no flap loss or gastrointestinal complications. One patient died from complications of sepsis unrelated to the surgical treatment. All surviving patients gained complete nutritional autonomy following closure of the loop jejunostomy.

Conclusion

Replacement of almost the entire native abdominal wall in patients with massive contaminated abdominal wall defects is possible, without the need for prosthetic material or microvascular free flaps. The subtotal pedicled thigh flap is a safe and effective method of providing definitive treatment for patients with massive enteroatmospheric fistulation.
Influence of hospital type on outcomes after oesophageal and gastric cancer surgery
Authors: Dikken J L , Wouters M W J M , Lemmens V E P , Putter H , van der Geest L G M , Verheij M , Cats A , van Sandick J W , van de Velde C J H
Published: May 2012

Background

Outcomes after oesophagectomy and gastrectomy vary considerably between hospitals. Possible explanations include differences in case mix, hospital volume and hospital type. The present study examined the distribution of oesophagectomies and gastrectomies between hospital types in the Netherlands, and the relationship between hospital type and outcome.

Methods

Data were obtained from the nationwide Netherlands Cancer Registry. Hospitals were categorized as university hospitals (UH), non-university teaching hospitals (NUTH) and non-university non-teaching hospitals (NUNTH). Hospital type–outcome relationships were analysed by Cox regression, adjusting for case mix, hospital volume, year of diagnosis and use of multimodal therapies.

Results

Between 1989 and 2009, 10 025 oesophagectomies and 14 221 gastrectomies for cancer were performed in the Netherlands. The percentage of oesophagectomies and gastrectomies performed in UH increased from 17·6 and 6·4 per cent respectively in 1989 to 44·1 and 12·9 per cent in 2009. After oesophagectomy, the 3-month mortality rate was 2·5 per cent in UH, 4·4 per cent in NUTH and 4·1 per cent in NUNTH (P = 0·006 for UH versus NUTH). After gastrectomy, the 3-month mortality rate was 4·9 per cent in UH, 8·9 per cent in NUTH and 8·7 per cent in NUNTH (P < 0·001 for UH versus NUTH). Three-year survival was also higher in UH than in NUTH and NUNTH.

Conclusion

Oesophagogastric resections performed in UH were associated with better outcomes but, owing to variation in outcomes within hospital types, centres of excellence cannot be designated solely on hospital type. Detailed information on case mix and outcomes is needed to identify centres of excellence.
Temporal and regional changes of superoxide dismutase and glutathione peroxidase activities in rats exposed to focal cerebral ischemia
Authors: Mršić‐Pelčić Jasenka , Pilipović Kristina , Pelčić Goran , Vitezić Dinko , Župan Gordana
Published: May 2012

Reactive oxygen species are important cause of tissue injury during cerebral ischemia and reperfusion (I/R). Superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) are intracellular enzymes responsible for endogenous antioxidant defense of tissues affected by I/R. The aim of this study was to examine temporal and regional changes of SOD and GSH‐Px activities in animals exposed to transient focal cerebral ischemia. Male Wistar Hannover rats were subjected to the right middle cerebral artery occlusion for 2 h. The animals were sacrificed immediately, 0·5, 1, 2, 3, 6, 24, 48, 72 or 168 h after ischemic procedure. SOD and GSH‐Px activities were determined spectrophotometrically in the hippocampus and parietal cortex, both unilaterally and contralaterally to the occlusion. Sham‐operated animals were used as the control group. Our results indicated that transient focal cerebral ischemia causes significant changes in SOD activities in the hippocampus and parietal cortex such as in GSH‐Px activities in the parietal cortex, unilaterally and contralaterally to the lesion in rats during different reperfusion periods. Statistically significant activation of GSH‐Px was registered neither in the right nor in the left hippocampus of ischemic animals. Copyright © 2012 John Wiley & Sons, Ltd.
The chicken or the egg: PHEX, FGF23 and SIBLINGs unscrambled
Authors: Rowe Peter S. N.
Published: May 2012

The eggshell is an ancient innovation that helped the vertebrates' transition from the oceans and gain dominion over the land. Coincident with this conquest, several new eggshell and noncollagenous bone‐matrix proteins (NCPs) emerged. The protein ovocleidin‐116 is one of these proteins with an ancestry stretching back to the Triassic. Ovocleidin‐116 is an avian homolog of Matrix Extracellular Phosphoglycoprotein (MEPE) and belongs to a group of proteins called Small Integrin‐Binding Ligand Interacting Glycoproteins (SIBLINGs). The genes for these NCPs are all clustered on chromosome 5q in mice and chromosome 4q in humans. A unifying feature of the SIBLING proteins is an Acidic Serine Aspartate‐Rich MEPE (ASARM)‐associated motif. The ASARM motif and the released ASARM peptide play roles in mineralization, bone turnover, mechanotransduction, phosphate regulation and energy metabolism. ASARM peptides and motifs are physiological substrates for phosphate‐regulating gene with homologies to endopeptidases on the X chromosome (PHEX), a Zn metalloendopeptidase. Defects in PHEX are responsible for X‐linked hypophosphatemic rickets. PHEX interacts with another ASARM motif containing SIBLING protein, Dentin Matrix Protein‐1 (DMP1). DMP1 mutations cause bone‐renal defects that are identical with the defects caused by loss of PHEX function. This results in autosomal recessive hypophosphatemic rickets (ARHR). In both X‐linked hypophosphatemic rickets and ARHR, increased fibroblast growth factor 23 (FGF23) expression occurs, and activating mutations in FGF23 cause autosomal dominant hypophosphatemic rickets (ADHR). ASARM peptide administration in vitro and in vivo also induces increased FGF23 expression. This review will discuss the evidence for a new integrative pathway involved in bone formation, bone‐renal mineralization, renal phosphate homeostasis and energy metabolism in disease and health. Copyright © 2012 John Wiley & Sons, Ltd.
Successful MALDI‐MS Analysis of Synthetic Polymers with Labile End‐Groups: The Case of Nitroxide‐Mediated Polymerization Using the MAMA‐SG1 Alkoxyamine
Authors: Barrère Caroline , Chendo Christophe , N. T. Phan Trang , Monnier Valérie , Trimaille Thomas , Humbel Stéphane , Viel Stéphane , Gigmes Didier , Charles Laurence
Published: May 2012

A sample pretreatment was evaluated to enable the production of intact cationic species of synthetic polymers holding a labile end‐group using matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry. More specifically, polymers obtained by nitroxide‐mediated polymerization involving the MAMA‐SG1 alkoxyamine were stirred for a few hours in trifluoroacetic acid (TFA) to induce the substitution of a tert‐butyl group on the nitrogen of nitroxide end‐group by a hydrogen atom. Nuclear magnetic resonance, electrospray ionization tandem mass spectrometry, and theoretical calculations were combined to scrutinize this sample pretreatment from both mechanistic and energetic points of view. The substitution reaction was found to increase the dissociation energy of the fragile CON bond to a sufficient extent to prevent this bond to be spontaneously cleaved during MALDI analysis. This TFA treatment is shown to be very efficient regardless of the nature of the polymer, as evidenced by reliable MALDI mass spectrometric data obtained for poly(ethylene oxide), polystyrene and poly(butylacrylate).
Electrostatic Precipitation – So much is left to do
Authors: Riebel Ulrich , Lübbert Christian , Lebedynskyy Sergiy
Published: May 2012

Der Elektroabscheider erlaubt eine energetisch besonders günstige Abscheidung von Stäuben und Aerosolen. Auch nach einer über 100jährigen Vorgeschichte von technischer Anwendung und wissenschaftlicher Forschung gibt es noch viel zu tun. Einerseits eröffnen aktuelle Entwicklungen der Technik und der Nachfrage neue Anwendungsbereiche für den Elektroabscheider, andererseits gilt es noch etliche Lücken beim Verständnis seiner Funktion zu schließen. Dieser Beitrag gibt einen Überblick über aktuelle Erkenntnisse und Entwicklungen.
Aqueous Surfactant Two‐Phase Systems for the Continuous Countercurrent Cloud Point Extraction
Authors: Ingram Thomas , Storm Sandra , Glembin Philipp , Bendt Stephan , Huber Désirée , Mehling Tanja , Smirnova Irina
Published: May 2012

Aqueous nonionic surfactant solutions split into two phases if the temperature is increased beyond a certain temperature, the so‐called cloud point temperature. Presently many different types of nonionic surfactants are produced commercially, out of these numerous have been considered as potential solvent for the cloud point extraction. In this work the crucial thermophysical properties of nonionic surfactants are investigated to determine the potential of surfactant systems for extraction processes. Phase equilibria of the binary system Triton X‐114/water and the ternary system Triton X‐114/water/phenol were measured. Based on these data the cloud point extraction was implemented in a continuous stirred extraction column. It was found, that increasing temperature within the column reduces the loss of surfactant and leads to an increasing enrichment factor. This work demonstrates that surfactant/water systems represent a suitable alternative to conventional solvents and can effectively be processed in continuous extraction columns.
Fundamentals towards a Modular Microstructured Production Plant
Authors: Helling Christoph , Fröhlich Holger , Eggersglüss Jan , Strube Jochen
Published: May 2012

For years, microtechnology is being considered as an emerging technique for chemical engineering tasks to overcome safety issues corresponding to high volumes and gaining higher selectivities and yields in reaction technology. Whereas in reaction technology a broad variety of microstructured equipment is available, in product purification/separation adequate equipment is missing. Research is focused on modular fast and flexible smaller production plants being operated continuously instead of batchwise in order to reduce engineering efforts and time‐to‐process. To cope with these demands, an appropriate definition of modules, which could be easily chosen and combined, is inevitable. In addition, these modules have to be well characterized concerning fluid dynamics and separation performance. This paper focuses on the characterization of available modules/devices. A standard method and analysis of the results concerning manufacturing accuracy and operation range is proposed. Miniplant technology is described as an efficient tool to validate process concepts proposed by process simulation studies. Necessary model parameters are determined for industrial complex mixtures in miniaturized laboratory equipment. Parameters are calculated model based to gain maximal accuracy. State of the art of miniplant technology is described and basic characteristic data are presented.
Value of Coronary Computed Tomography as a Prognostic Tool
Authors: Contractor Tahmeed , Parekh Maansi , Ahmed Shameer , Martinez Matthew W.
Published: May 2012

Coronary computed tomography angiography (CCTA) has become an important part of our armamentarium for noninvasive diagnosis of coronary artery disease (CAD). Emerging technologies have produced lower radiation dose, improved spatial and temporal resolution, as well as information about coronary physiology. Although the prognostic role of coronary artery calcium scoring is known, similar evidence for CCTA has only recently emerged. Initial, small studies in various patient populations have indicated that CCTA‐identified CAD may have a prognostic value. These findings were confirmed in a recent analysis of the international, prospective Coronary CT Angiography Evaluation For Clinical Outcomes: An International Multicenter (CONFIRM) registry. An incremental increase in mortality was found with a worse severity of CAD on a per‐patient, per‐vessel, and per‐segment basis. In addition, age‐, sex‐, and ethnicity‐based differences in mortality were also found. Whether changing our management algorithms based on these findings will affect outcomes is unclear. Large prospective studies utilizing targeted management strategies for obstructive and nonobstructive CAD are required to incorporate these recent findings into our daily practice. Clin. Cardiol. 2012 DOI: 10.1002/clc.22003

The authors have no funding, financial relationships, or conflicts of interest to disclose.
Involuntary Memories after a Positive Film Are Dampened by a Visuospatial Task: Unhelpful in Depression but Helpful in Mania?
Authors: Davies Charlotte , Malik Aiysha , Pictet Arnaud , Blackwell Simon E. , Holmes Emily A.
Published: May 2012

Spontaneous negative mental images have been extensively researched due to the crucial role they play in conditions such as post‐traumatic stress disorder. However, people can also experience spontaneous positive mental images, and these are little understood. Positive images may play a role in promoting healthy positive mood and may be lacking in conditions such as depression. However, they may also occur in problematic states of elevated mood, such as in bipolar disorder. Can we apply an understanding of spontaneous imagery gained by the study of spontaneous negative images to spontaneous positive images? In an analogue of the trauma film studies, 69 volunteers viewed an explicitly positive (rather than traumatic) film. Participants were randomly allocated post‐film either to perform a visuospatial task (the computer game ‘Tetris’) or to a no‐task control condition. Viewing the film enhanced positive mood and immediately post‐film increased goal setting on a questionnaire measure. The film was successful in generating involuntary memories of specific scenes over the following week. As predicted, compared with the control condition, participants in the visuospatial task condition reported significantly fewer involuntary memories from the film in a diary over the subsequent week. Furthermore, scores on a recognition memory test at 1 week indicated an impairment in voluntary recall of the film in the visuospatial task condition. Clinical implications regarding the modulation of positive imagery after a positive emotional experience are discussed. Generally, boosting positive imagery may be a useful strategy for the recovery of depressed mood. Copyright © 2012 John Wiley & Sons, Ltd.

Key Practitioner Message

After a positive film, volunteers can experience involuntary ‘pop‐out’ memories of that film over the subsequent week.

Performing a visuospatial task (the computer game Tetris) immediately after the positive film reduces spontaneous image memories and also impairs voluntary memory for details of the film.

Understanding the mechanisms underlying positive spontaneous imagery may offer insights for treatment innovation both for those conditions characterized by a deficit in positive imagery, such as depression, and for those characterized by a proliferation of positive imagery, such as mania.

Furthermore, this may suggest that the routine everyday tasks we engage in after a positive emotional event could have a significant impact on our memories of positive experiences.
Shadowing fade margin and coverage probability analysis for HAP mobile communication systems
Authors: Zhu Li‐ping , Chen Zhihong , Zhu Yi‐Sheng
Published: May 2012

An existing elevation dependent shadowing model for high‐altitude platform (HAP) mobile communication in built‐up areas is employed to perform the area coverage probability analysis and fading margin computation for HAP mobile communication systems. A generalized expression for the PDF of the received signal power in the HAP coverage is derived. The shadowing fade margin model that can characterize different types of built‐up area is developed. Theoretical relations between shadowing fade margin and outage probability and cell coverage probability are given. Numerical simulation for isoflux coverage HAP‐based system shows that there is great difference in the value of shadowing fade margin under line‐of‐sight and non‐line‐of‐sight conditions for the same outage probability. It is also found that the cell coverage probability is insensitive to the variance of the shadowing fade margin in suburban environment whatever the size of the cell and for small cells in urban high‐rise environments.Copyright © 2012 John Wiley & Sons, Ltd.
The relation between maternal emotional support and child physiological regulation across the preschool years
Authors: Perry Nicole B. , Nelson Jackie A. , Swingler Margaret M. , Leerkes Esther M. , Calkins Susan D. , Marcovitch Stuart , O'Brien Marion
Published: May 2012

Trajectories of baseline RSA (respiratory sinus arrhythmia), an index of reactivity, and vagal withdrawal, an index of regulation, across the preschool period were examined. In addition, maternal emotional support was investigated as a potential time‐varying predictor of these trajectories. Physiological measures were obtained during frustration tasks, and a maternal emotional support measure was assessed via maternal report and direct observation. Children's baseline RSA and vagal withdrawal scores were moderately stable across the preschool period. Growth models indicated that children's baseline RSA scores changed linearly over the preschool years, and there was significant variability in withdrawal trajectories. Greater maternal emotional support predicted higher initial withdrawal levels and lower emotional support was associated with the greatest increase in withdrawal over time. This suggests that children of higher emotionally supportive mothers reached higher levels of physiological regulation earlier in development and therefore did not show the same increase across preschool as children of less supportive mothers. Maternal emotional support was not significantly related to trajectories of baseline RSA. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 382–394, 2013
Maternal inhibition of infant behavioral response following isolation in novel surroundings and inflammatory challenge
Authors: Hennessy Michael B. , Jacobs Sarah , Schiml Patricia A. , Hawk Kiel , Stafford Nathan , Deak Terrence
Published: May 2012

During isolation in a novel environment, guinea pig pups gradually begin to display passive behavior that appears to be mediated by proinflammatory activity, that is, “sickness behavior.”. Administration of substances that increase proinflammatory activity [corticotropin‐releasing factor (CRF), lipopolysaccharide (LPS)] prior to isolation induces passive behavior from the beginning of the isolation episode. Here, we show that reunion with the mother in the novel environment rapidly and potently suppresses the passive behavior of isolated pups (Experiment 1); inhibits the passive behavior of pups administered CRF (10 µg, subcutaneous; Experiment 2); and inhibits the passive behavior of male, though not female, pups administered LPS (250 µg/kg, intraperitoneal; Experiment 3). Together these findings suggest that the presence of the mother either recruits other processes that moderate the impact of proinflammatory processes on brain mechanisms mediating the passive response or initiates compensatory mechanisms that counter the effect of proinflammatory activity. Further, the results suggest that for physically ill animals of social species, the adaptive advantage that accrues from maintaining normal social interactions may sometimes outweigh the advantage gained by engaging in sickness behavior. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 395–403, 2013
Multiple drift responses of benthic invertebrates to interacting hydropeaking and thermopeaking waves
Authors: Bruno M. C. , Siviglia A. , Carolli M. , Maiolini B.
Published: May 2012

Sudden instream releases of hypolimnetic water from hydropower plants [i.e. hydropeaking (HP)] can cause abrupt temperature variations [i.e. thermopeaking (TP)], typically on a daily basis. The propagation of discharge and thermal waves is asynchronous, causing the benthic community to undergo two different but consecutive impacts. Invertebrates respond to sudden increases in discharge with catastrophic drift, and respond to sudden changes of temperature with behavioural drift. Owing to the time lag separating discharge and thermal wave peaks, catastrophic and behavioural drift can occur as distinct events. We conducted simulations in a set of open air flumes directly fed by an Alpine stream, and analysed drift induction in benthic invertebrates caused by a HP wave followed by a cold TP wave, and compared it with drift induced only by a cold TP wave. Drift propensity increased during HP and TP simulations, with a synergic effect: drift was higher when the TP wave followed the HP one. We also recorded a selective effect: some taxa did not respond to the alterations, some taxa responded to the discharge variations and to the thermal variations, or to the thermal variations alone. The most abundant taxa in benthos were Chironomidae and Baetidae, followed by Simuliidae. Simuliidae and Chironomidae were the most abundant drifting taxa. Copyright © 2012 John Wiley & Sons, Ltd.
Bio‐Metallodendrimers – Emerging Strategies in Metal‐Based Drug Design
Authors: Govender Preshendren , Therrien Bruno , Smith Gregory S.
Published: May 2012

The field of biomedical metallodendrimers is an emerging discipline that is attracting prolific attention. Metallodendrimers, like their organic counterparts, are known for their multivalency (high concentration of peripheral end‐groups), well‐defined architectures and narrow polydispersity. These are characteristics that make metallodendrimers well‐suited as innovative scaffolds for the development of new therapeutic agents. Coupled with the surge of interest in the use of various metal complexes to treat various diseases, the application of metallodendrimers in medicinal chemistry is an attractive strategy for therapies involving macromolecules and the advancement of new metal‐based therapeutics. In this review, we describe the progress made in the application of metallodendrimers as scaffolds for drug delivery, as metal‐based drugs in their own right, and as agents for biosensing, photothermal and photodynamic therapy.
Nitrogen‐Doped Carbon Hollow Spheres for Immobilization, Direct Electrochemistry, and Biosensing of Protein
Authors: Zhang Zhaohang , Zhang Rong , Li Cancan , Yuan Liang , Li Peipei , Yao Li , Liu Songqin
Published: May 2012

Nitrogen‐doped carbon hollow spheres (NCHS) were designed for the immobilization and biosensing of proteins. Chitosan was first functionalized with glutaraldehyde to form cross‐linked chitosan with free CHO groups (GCS). The as‐prepared GCS was used for dispersion of nitrogen‐doped carbon hollow spheres. Using glucose oxidase (GOD) as a model, the NCHS was tested for immobilization of redox proteins and the design of electrochemical biosensors. GOD molecules immobilized in the nanocomposites showed direct electrochemistry with a formal potential of −0.448 V and well electrochemical performance. The proposed biosensor exhibited a linear response to glucose concentrations ranging from 3.7 µM to 18.0 mM with a detection limit of 1.2 µM and a sensitivity of 11.85 µA mM−1. This biosensor was also applied to detect glucose in human serum samples, accomplishing good recovery in the range of 92–105 %. The nanocomposites provided a good matrix for protein immobilization and biosensor fabrication.
PEDOT‐Modified Microelectrodes. Preparation, Characterisation and Analytical Performances
Authors: Pigani L. , Zanfrognini B. , Seeber R.
Published: May 2012

Poly(3,4‐ethylenedioxythiophene) (PEDOT) modified microelectrodes were prepared by electropolymerisation of the relevant monomer from CH3CN or H2O solutions. The electrochemical behaviour of the obtained coatings was investigated by cyclic voltammetry in both organic and aqueous media. The anodic responses obtained for a typical benchmark analyte such as ascorbic acid was used to test the different coatings; calibration curves were built up in order to evaluate the repeatability of the response and the reproducibility of the prepared sensing system. Moreover, the ability of the modified microelectrodes to work in low conductivity media was studied, and exploratory tests in dense food matrix was performed.
Novel Amperometric Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Azide Covalently Immobilized on Ethynyl‐Modified Screen‐Printed Carbon Electrode via Click Chemistry
Authors: Hayat Akhtar , Marty Jean‐Louis , Radi Abd‐Elgawad
Published: May 2012

A novel, simple and versatile protocol for covalent immobilization of horseradish peroxidase (HRP) on screen‐printed carbon electrode (SPCE) based on the combination of diazonium salt electrografting and click chemistry has been successfully developed. The ethynyl‐terminated monolayers are obtained by diazonium salt electrografting, then, in the presence of copper (I) catalyst, the ethynyl modified surfaces reacted efficiently and rapidly with horseradish peroxidase bearing an azide function (azido‐HRP), thus forming a covalent 1,2,3‐triazole linkage by means of click chemistry. All the experimental results suggested that HRP was immobilized onto the electrode surface successfully without denaturation. Furthermore, the immobilized HRP showed a fast electrocatalytic reduction for H2O2. A linear range from 5.0 to 50.0 µM in a phosphate buffer (pH 5.5) with detection limit of 0.50 µM and sensitivity of 0.23 nA/µM were obtained. The heterogeneous electron transfer rate constant Kct was 1.52±0.22 s−1 and the apparent MichaelisMenten constant was calculated to be 0.028 mM. The HRP‐functionalized electrode demonstrated a good reproducibility and long‐term stability.
Miniaturized Electrochemical Immunosensor for Label‐Free Detection of Growth Hormone
Authors: Li Qi , Li Nan , Le Tissier Paul , Grattan David R. , Kerman Kagan
Published: May 2012

A miniaturized immunosensor was developed in connection with disposable screen‐printed carbon strips (SPCS) for the point‐of‐care detection of growth hormone. The performance of the miniaturized system was studied using growth hormone (GH) as the target protein and compared with a conventional electrochemical analyzer. The detection limit of 25 pg/mL was observed for GH in 20 µL sample volume, which indicated that this versatile platform can be easily adapted for decentralized electrochemical immunosensing of clinically important proteins.
Toxicity of elevated partial pressures of carbon dioxide to invasive New Zealand mudsnails
Authors: Nielson R. Jordan , Moffitt Christine M. , Watten Barnaby J.
Published: May 2012

The authors tested the efficacy of elevated partial pressures of CO2 to kill invasive New Zealand mudsnails. The New Zealand mudsnails were exposed to 100 kPa at three water temperatures, and the survival was modeled versus dose as cumulative °C-h. We estimated an LD50 of 59.4°C-h for adult and juvenile New Zealand mudsnails. The results suggest that CO2 may be an effective and inexpensive lethal tool to treat substrates, tanks, or materials infested with New Zealand mudsnails. Environ. Toxicol. Chem. 2012; 31: 1838–1842. © 2012 SETAC
Differential distribution of diacylglycerol lipase‐alpha and N‐acylphosphatidylethanolamine‐specific phospholipase d immunoreactivity in the superficial spinal dorsal horn of rats
Authors: Hegyi Zoltán , Holló Krisztina , Kis Gréta , Mackie Ken , Antal Miklós
Published: May 2012

It is generally accepted that the endocannabinoid system plays important roles in spinal pain processing. Although it is documented that cannabinoid‐1 receptors are strongly expressed in the superficial spinal dorsal horn, the cellular distribution of enzymes that can synthesize endocannabinoid ligands is less well studied. Thus, using immunocytochemical methods at the light and electron microscopic levels, we investigated the distribution of diacylglycerol lipase‐alpha (DGL‐α) and N‐acylphosphatidylethanolamine‐specific phospholipase D (NAPE‐PLD), enzymes synthesizing the endocannabinoid ligands, 2‐arachidonoylglycerol (2‐AG) and anandamide, respectively. Positive labeling was revealed only occasionally in axon terminals, but dendrites displayed strong immunoreactivity for both enzymes. However, the dendritic localization of DGL‐α and NAPE‐PLD showed a remarkably different distribution. DGL‐α immunolabeling in dentrites was always revealed at membrane compartments in close vicinity to synapses. In contrast to this, dendritic NAPE‐PLD labeling was never observed in association with synaptic contacts. In addition to dendrites, a substantial proportion of astrocytic (immunoreactive for GFAP) and microglial (immunoreactive for CD11b) profiles were also immunolabeled for both DGL‐α and NAPE‐PLD. Glial processes immunostained for DGL‐α were frequently found near to synapses in which the postsynaptic dendrite was immunoreactive for DGL‐α, whereas NAPE‐PLD immunoreactivity on glial profiles at the vicinity of synapses was only occasionally observed. Our results suggest that both neurons and glial cells can synthesize and release 2‐AG and anandamide in the superficial spinal dorsal horn. The 2‐AG can primarily be released by postsynaptic dendrites and glial processes adjacent to synapses, whereas anandamide can predominantly be released from nonsynaptic dendritic and glial compartments. © 2012 Wiley Periodicals, Inc.
From protein interaction networks to novel therapeutic strategies
Authors: Jaeger Samira , Aloy Patrick
Published: May 2012

Cellular mechanisms that sustain health or contribute to disease emerge mostly from the complex interplay among various molecular entities. To understand the underlying relationships between genotype, environment and phenotype, one has to consider the intricate and nonsequential interaction patterns formed between the different sets of cellular players. Biological networks capture a variety of molecular interactions and thus provide an excellent opportunity to consider physiological characteristics of individual molecules within their cellular context. In particular, the concept of network biology and its applications contributed largely to recent advances in biomedical research. In this review, we show (i) how biological networks, i.e., protein–protein interaction networks, facilitate the understanding of pathogenic mechanisms that trigger the onset and progression of diseases and (ii) how this knowledge can be translated into effective diagnostic and therapeutic strategies. In particular, we focus on the impact of network pharmacological concepts that go beyond the classical view on individual drugs and targets aiming for combinational therapies with improved clinical efficacy and reduced safety risks. © 2012 IUBMB Life, 2012
Transforming growth factor‐β activates c‐Myc to promote palatal growth
Authors: Zhu Xiujuan , Ozturk Ferhat , Liu ChangChih , Oakley Gregory G. , Nawshad Ali
Published: May 2012

During palatogenesis, the palatal mesenchyme undergoes increased cell proliferation resulting in palatal growth, elevation and fusion of the two palatal shelves. Interestingly, the palatal mesenchyme expresses all three transforming growth factor (TGF) β isoforms (1, 2, and 3) throughout these steps of palatogenesis. However, the role of TGFβ in promoting proliferation of palatal mesenchymal cells has never been explored. The purpose of this study was to identify the effect of TGFβ on human embryonic palatal mesenchymal (HEPM) cell proliferation. Our results showed that all isoforms of TGFβ, especially TGFβ3, increased HEPM cell proliferation by up‐regulating the expression of cyclins and cyclin‐dependent kinases as well as c‐Myc oncogene. TGFβ activated both Smad‐dependent and Smad‐independent pathways to induce c‐Myc gene expression. Furthermore, TBE1 is the only functional Smad binding element (SBE) in the c‐Myc promoter and Smad4, activated by TGFβ, binds to the TBE1 to induce c‐Myc gene activity. We conclude that HEPM proliferation is manifested by the induction of c‐Myc in response to TGFβ signaling, which is essential for complete palatal confluency. Our data highlights the potential role of TGFβ as a therapeutic molecule to correct cleft palate by promoting growth. J. Cell. Biochem. 113: 3069–3085, 2012. © 2012 Wiley Periodicals, Inc.
Alcohol Problems, Aggression, and Other Externalizing Behaviors After Return From Deployment: Understanding the Role of Combat Exposure, Internalizing Symptoms, and Social Environment
Authors: Wright Kathleen M. , Foran Heather M. , Wood Michael D. , Eckford Rachel D. , McGurk Dennis
Published: May 2012

Objectives

The study examined whether elevated rates of externalizing behaviors following deployment could be explained by internalizing symptoms (depression, anxiety, and PTSD symptoms), and health of the social environment (unit leadership, organizational support, and stigma/barriers to care).

Design

A model of combat exposure, social environment, internalizing symptoms, and externalizing behaviors was tested in a military unit following a fifteen‐month deployment to Iraq. The sample included 1,397 soldiers assessed four month post‐deployment; 589 of these soldiers were assessed again nine months post‐deployment.

Results

Externalizing behaviors were highly stable over the five‐month post‐deployment period. Both social environment and internalizing symptoms were significantly associated with level of externalizing behaviors at four months and nine months post‐deployment, but combat exposure alone significantly predicted change in externalizing behaviors over the follow‐up period.

Conclusions

Results suggest the need to broaden the scope of interventions targeted to combat veterans and have implications for care providers and military leaders. © 2012 Wiley Periodicals, Inc. J. Clin. Psychol. 68:782‐800, 2012
The effects of arsenic on the growth and nutritional status of Anadenanthera peregrina, a Brazilian savanna tree
Authors: Gomes Marcelo Pedrosa , Moreira Duarte Daniela , Silva Miranda Pedro Luiz , Carvalho Barreto Leilane , Matheus Miele Tallon , Garcia Queila Souza
Published: May 2012

Anadenanthera peregrina is a Brazilian savanna tree species that occurs naturally in arsenic (As)‐contaminated areas, and its As resistance has been associated with arbuscular mycorrhizal–fungi (AMF) symbiosis. A plant's ability to survive in stressful environments is correlated with its nutrition status, which can be affected by As uptake. The present study evaluated the influence of As on the concentrations and distribution of nutrients in the roots and shoots of A. peregrina grown in the absence of AMF. These plants were grown in substrates spiked with 0, 10, 50, and 100 mg As kg–1 for 25 d under greenhouse conditions, and the concentrations of essential macro‐ (P, K, Ca, Mg, N, and S) and micro‐ (Fe, Mn, Cu, Zn, B, and Mo) nutrients in the roots and shoots were then determined. Enhanced As levels increased the concentrations of P, S, and N and decreased Ca, Mg, and Fe. Although the deleterious effects of As on the plants were striking, the internal As levels were high, which indicated some tissue tolerance of A. peregrina.
Changes in soil C, N, and P with long‐term (58 years) cattle grazing on rough fescue grassland
Authors: Li Chunli , Hao Xiying , Ellert Benjamin H. , Willms Walter D. , Zhao Mengli , Han Guodong
Published: May 2012

We investigated soil response to long‐term cattle grazing at stocking rates 0 (CK), 2.4 (MG), and 4.8 (HG) animal unit months ha–1 on a Rough Fescue (Festuca campestris Rydb.) grassland. Soil organic C and N stocks and available nutrients were not affected by grazing while soil bulk densities (0–30 cm) were higher and P stocks (15–30 cm) were lower under grazing than CK. The slow rate change of soil C and N suggest the rich black grassland soils appear to tolerate intensive grazing.
Root‐growth characteristics contributing to genotypic variation in nitrogen efficiency of oilseed rape
Authors: Ulas Abdullah , Schulte auf'm Erley Gunda , Kamh Mahmoud , Wiesler Franz , Horst Walter J.
Published: May 2012

A 3‐year field experiment was carried out to determine the significance of root‐growth characteristics contributing to N‐uptake efficiency of two oilseed rape (Brassica napusL.) cultivars differing in N efficiency. Two N treatments were applied, and the core and minirhizotron techniques were used to study root‐length density and number of living roots, respectively. Fertilizer‐N supply increased shoot dry matter, grain yield, total N uptake, and total soil Nmincontents particularly in the top soil. Although significant differences occurred in all parameters between years, the interactions between years and cultivars were mostly not significant. Compared to cv. Capitol, the N‐efficient cv. Apex was characterized by a higher grain yield at N0 and a higher N uptake during reproductive growth. This genotype also had a higher root‐length density and more living fine roots particularly in the topsoil layer. Root growth of this genotype was especially high from beginning of shooting to beginning of flowering, while shoot growth and N uptake during vegetative growth were comparatively low. Our results suggest that N‐efficient cultivars can be characterized by a high investment in root growth during the vegetative stage with a comparatively slow shoot growth and N‐uptake rate until beginning of flowering, which, however, continues during reproductive growth. High root production only during reproductive growth seems to be less effective to achieve high N efficiency, because this may lead to a shortage of assimilates for seed filling. High root‐length density at vegetative stages may thus be advantageous for N uptake and reproductive growth and could be a useful morphological character for the selection and breeding of N‐efficient cultivars.
THE CAUSES AND CONSEQUENCES OF ENVIRONMENTAL CHANGES IN GEDAREF, SUDAN
Authors: Glover E. K. , Elsiddig E. A.
Published: May 2012

Studies in several countries in Africa using remote sensing and conventional aerial photography indicate acute land degradation, which is an issue of global concern as it poses a great threat to stability of world climate, biodiversity and geodiversity. Mechanized scheme farms schemes in Sudan are perceived as a major cause of environmental degradation and land losses. Investigations were thus conducted within forests reserves and natural forests sites in the Gedaref area in eastern Sudan where mechanized farmers and traditional land users inside and outside forests reserves represented the target categories for the study. The target groups were interviewed to evaluate their knowledge, attitudes and perceptions with respect to the causes of environmental degradation of soil, forests, agricultural productivity and animal resources. Interviews were conducted among 162 farmers in addition to group discussion among key informants. The results are presented as descriptive statistics, which indicate that forest conversion to agriculture associated with over‐cutting has been the main factor contributing to land degradation in Gedaref State. The results also indicate that there are other causes that include sectoral policies that contradict each other, affecting land ownership. The present study demonstrates the need for integrated policies to facilitate sustainable use and management based on local community's partnership and to encourage communal property rights and local‐level institutional regimes that ensure sustainable resource management and protection of biodiversity and geodiversity across Sudan. Copyright © 2012 John Wiley & Sons, Ltd.
Singular linear quadratic optimal control for singular stochastic discrete‐time systems
Authors: Feng Jun‐e , Cui Peng , Hou Zhongsheng
Published: May 2012

The finite time horizon singular linear quadratic (LQ) optimal control problem is investigated for singular stochastic discrete‐time systems. The problem is transformed into positive LQ one for standard stochastic systems via two equivalent transformations. It is proved that the singular LQ optimal control problem is solvable under two reasonable rank conditions. Via dynamic programming principle, the desired optimal controller is presented in terms of matrix iterative form. One simulation is provided to show the effectiveness of the proposed approaches. Copyright © 2012 John Wiley & Sons, Ltd.