bluuebunny/crossref_metadata_2025 huggingface dataset:
The Caspase Pathway as a Possible Therapeutic Target in Experimental Pemphigus
Authors: Pacheco-Tovar Deyanira , López-Luna Argelia , Herrera-Esparza Rafael , Avalos-Díaz Esperanza
Published: March 2011

Apoptosis plays a role in pemphigus IgG-dependent acantholysis; theoretically, the blockade of the caspase pathway could prevent the blistering that is caused by pemphigus autoantibodies. Using this strategy, we attempted to block the pathogenic effect of pemphigus IgG in Balb/c mice by using the caspase inhibitor Ac-DEVD-CMK. This inhibitor was administrated before the injection of pemphigus IgG into neonatal mice. The main results of the present investigation are as follows: (1) pemphigus IgG induces intraepidermal blisters in Balb/c neonatal mice; (2) keratinocytes around the blister and acantholytic cells undergo apoptosis; (3) the caspases inhibitor Ac-DEVD-CMK prevents apoptosis; (4) the inhibition of the caspase pathway prevents blister formation. In conclusion, inhibition of the caspase pathway may be a promising therapeutic tool that can help in the treatment of pemphigus flare ups.
Surficial geology of the Laurentian Channel and the western Grand Banks of Newfoundland
Authors: Fader G B , King L H , Josenhans H W
Published: March 2011

Five surficial formations are identified on the basis of high resolution seismic re
2010 Canada Basin Seismic Reflection and Refraction Survey, western Arctic Ocean: CCGS Louis S. St-Laurent expedition report August 4 - September 15, 2010 Kugluktuk, NWT to Kugluktuk, NWT
Authors: Mosher D C , Shimeld J W , Chapman C B
Published: March 2011

The principal objective of the 2010 Canadian Polar Margin Seismic Reflection and Refraction Survey was to acquire multichannel seismic reflection and refraction data along positions that serve to establish sediment thicknesses and acquire bathymetric soundings
along Canadian and US western Arctic continental margins. Strategic ship track lines were established to complement existing data to meet UNCLOS Extended Continental Shelf (ECS) sediment thickness, bathymetric and scientific objectives. In addition to the geoscience program, ice observations were
acquired to groundtruth remotely sensed data. Seismic system calibration experiments were conducted to quantify sound signal intensity levels produced by the sound source. 3673 line-km of high quality multichannel seismic reflection data were acquired in addition to seismic refraction data recorded
from 34 sonobuoy deployments. 9500 line-km of single beam bathymetry data were obtained plus 61 helicopter spot soundings. In collaboration the United States Coast Guard Cutter Healy, similar amounts of multibeam bathymetric and chirp subbottom profiler data were acquired.
Plasma Leptin, hTERT Gene Expression, and Anthropometric Measures in Obese and Non-Obese Women with Breast Cancer
Authors: Rahmati-Yamchi Mohammad , Zarghami Nosratallah , Rahbani Mohammad , Montazeri Ali
Published: March 2011

Introduction

Expression of human telomerase reverse transcriptase (hTERT) occurs in most cancers but its relation with obesity is unclear. This study explores the association between leptin levels and anthropometric indices with hTERT mRNA levels in breast cancer patients of different obesity grades.

Materials and methods

In this case-control study, 65 breast cancer patients participated. Expression of tissues hTERT mRNA was carried out by real-time reverse transcription polymerase chain reaction. Leptin concentrations were measured by enzyme-linked immunoassay.

Results

Twelve patients (18.46%) were hTERT negative and 53(81.54%) were positive. hTERT mRNA levels were associated with BMI but not with waist circumference (WC) (r = 0.219, P = 0.22) and waist to hip ratio (WHR) (r = 0.212, P = 0.237). Leptin level and hTERT mRNA levels (r = 0.484, P = 0.008) were correlated as well as BMI and hTERT expression.

Conclusions

This study has shown a correlation between leptin levels and hTERT expression. These findings may clarify the role of leptin in breast carcinogenesis, and hence obesity could be responsible for increased incidences in breast cancer as well as its progression via enhanced production of leptin.
Article Commentary: Secondhand Smoking in Jordan: Clearing the Air for One of the Highest Tobacco Prevalence Countries in the Middle East
Authors: Haddad Linda G. , Al-Zyoud Sukaina , Baker Nesrin Abu , Gharaibeh Huda , Shahawy Omar El , Alramadhani Raed
Published: March 2011

As the rate of tobacco consumption in Jordan increases, Jordanian policy makers are urged to develop guidelines on smoking exposures. This paper is concerned with the magnitude of exposure and harm caused by secondhand smoke (SHS) on childbearing women and young children. Despite a strict policy that limits tobacco advertising and efforts by the Ministry of Health, which include cessation programs and education on the adverse effect of smoking, the country sustains its high smoking rate, especially among men. According to the data gathered in this paper, special concern should be directed toward children's SHS exposure. Only four recent studies on SHS exposure among Jordanian women and children were encountered. Moreover, Jordan has legislation that bans smoking in public institutions; however, the enforcement of the law is extremely poor in most locations. Recommendations are presented to aid policy makers and law enforcement agencies in addressing this issue.
Geometric Group Theory, Hyperbolic Dynamics and Symplectic Geometry
Authors: Knieper Gerhard , Polterovich Leonid , Potyagailo Leonid
Published: March 2011

The main theme of the workshop is the interaction between the speedily developing fields of mathematics mentioned in the title. One of the purposes of the workshop is to highlight new exciting developments which are happening right now on the borderline between hyperbolic dynamics, geometric group theory and symplectic geometry.
Mini-Workshop: Mechanics of Cell Motion
Authors: Alt Wolfgang , Ambrosi Davide
Published: March 2011

This mini-workshop brought together established researchers and newer entrants in the field of cell motility, a challenging research area located at the crossroads of biology, mathematics and physics.Cell locomotion occurs through complex interactions that involve, among others, actin polymerization, matrix degradation, chemical signaling, adhesion and pulling on the substrate and fibers. In recent years the spatial resolution of experiments at a cellular and sub-cellular level have revealed a landscape of unexpected behaviors that demand for the application of physics and classical mathematical methods to reveal the principles that are at the basis of cell motion in terms of adhesion, directionality, internal engines. The focus of the mini-workshop was on the fundamental research in mathematical methods for biophysics of the cell, especially on the mathematical framework for the mechanics of the actin network, the
encadrement
of cellular traction as an inverse problem and the relation between cell-to-cell communication and morphogenesis.
Mini-Workshop: Combinatorics on Words
Authors: Berthe Valerie , Karhumäki Juhani , Nowotka Dirk , Shallit Jeffrey
Published: March 2011

The area of combinatorics on words is concerned with properties of sequences of symbols. It is characteristic to the field that questions arise from various mathematical problems, and hence, many fundamental results on words have been established in different areas. Over the last two decades the theory has developed into a quickly growing topic of its own. This work-shop was dedicated to reflect on the current status of the field, discuss the impact of recent results, and provide new research challenges. This is a report on the meeting and presentation of extended abstracts of the lectures.
Existence of ground states for nonlinear, pseudo-relativistic Schrödinger equations
Authors: Coti Zelati Vittorio , Nolasco Margherita
Published: March 2011

We study existence and regularity of positive stationary solutions for a class of nonlinear pseudo-relativistic Schrödinger equations. Such equations are characterized by a nonlocal pseudo-differential operator closely related to the square-root of the Laplacian. We investigate such problems using critical point theory after transforming them to elliptic equations with nonlinear Neumann boundary conditions.
The ephemeral nature of Navier–Stokes-$\alpha\beta$ continua
Authors: Capriz Gianfranco , Fried Eliot
Published: March 2011

Navier–Stokes-

\alpha\beta

continua are shown to be a special subclass of the recently introduced class of ephemeral continua that arises when particular constraints and constitutive relations are introduced. Beside offering a new endorsement of balance equations already obtained by numerous Authors, our study offers a chance for enlightening remarks, remarks that might possibly lead to further developments.
Simulated effects of changes in direct and diffuse radiation on canopy scale isoprene emissions from vegetation following volcanic eruptions
Authors: Wilton D. J. , Hewitt C. N. , Beerling D. J.
Published: March 2011

Abstract. Volcanic eruptions can alter the quality of incoming solar irradiance reaching the Earth's surface thereby influencing the interactions between vegetation and the Earth system. Isoprene (C5H8) is a biogenic volatile organic compound emitted from leaves at a rate strongly dependent on the received flux of photosynthetically radiation radiation (PAR). We investigated the potential for volcanic eruptions to change the isoprene flux from terrestrial vegetation using canopy-scale isoprene emission simulations that vary either the relative or absolute amount of diffuse (Idiff) and direct (Idir) PAR. According to our simulations, if the total amount of PAR remains constant while the proportion of Idiff increases, canopy-scale isoprene emissions increase. This effect increases as leaf area index increases. Simulating a~decrease in the total amount of PAR, and a corresponding increase in Idiff fraction, as measured during the 1992 Pinatubo eruption, decreases daily total canopy-scale isoprene emissions from terrestrial vegetation by 17–19% (for leaf area indices of 6 and 2, respectively). These effects have not previously been realized or quantified. Better capturing the effects of volcanic eruptions (and other major perturbations to the atmospheric aerosol content) on isoprene emissions from the terrestrial biosphere, and hence on the chemistry of the atmosphere, therefore requires inclusion of the effects of aerosols they produce on climate and total PAR and the Idiff/Idir ratio.
Global cloud condensation nuclei influenced by carbonaceous combustion aerosol
Authors: Spracklen D. V. , Carslaw K. S. , Pöschl U. , Rap A. , Forster P. M.
Published: March 2011

Abstract. Black carbon in carbonaceous combustion aerosol warms the climate by absorbing solar radiation, meaning reductions in black carbon emissions are often perceived as an attractive global warming mitigation option. However, carbonaceous combustion aerosol can also act as cloud condensation nuclei (particles upon which cloud drops form) so they also cool the climate by increasing cloud albedo. The net radiative effect of carbonaceous combustion aerosol is uncertain because their contribution to cloud drops has not been evaluated on the global scale. By combining extensive observations of cloud condensation nuclei concentrations and a global aerosol model, we show that carbonaceous combustion aerosol accounts for more than half of global cloud condensation nuclei. The evaluated model predicts that wildfire and pollution (fossil fuel and biofuel) carbonaceous combustion aerosol causes a global mean aerosol indirect effect of −0.34 W m−2 due to changes in cloud albedo, with pollution sources alone causing a global mean aerosol indirect effect of −0.23 W m−2. The small size of carbonaceous combustion particles from pollution sources means that whilst they account for only one-third of the emitted mass from these sources they cause two-thirds of the cloud albedo indirect effect that is due to carbonaceous combustion aerosol. This cooling effect must be accounted for to ensure that black carbon emissions controls that reduce the high number concentrations of small pollution particles have the desired net effect on climate.
Oxidation photochemistry in the Southern Atlantic boundary layer: unexpected deviations of photochemical steady state
Authors: Hosaynali Beygi Z. , Fischer H. , Harder H. D. , Martinez M. , Sander R. , Williams J. , Brookes D. M. , Monks P. S. , Lelieveld J.
Published: March 2011

Abstract. Ozone (O3) is a photochemical oxidant, an air pollutant and a greenhouse gas. As the main precursor of the hydroxyl radical (OH) it strongly affects the oxidation power of the atmosphere. The remote marine boundary layer (MBL) is considered an important region in terms of chemical O3 loss; however surface-based atmospheric observations are sparse and the photochemical processes are not well understood. To investigate the photochemistry under the clean background conditions of the Southern Atlantic Ocean, ship measurements of NO, NO2, O3, JNO2, J(O1D), HO2, OH, ROx and a range of meteorological parameters were carried out. The concentrations of NO and NO2 measured on board the French research vessel Marion-Dufresne (28° S–57° S, 46° W–34° E) in March 2007, are among the lowest yet observed. The data is evaluated for consistency with photochemical steady state (PSS) conditions, and the calculations indicate substantial deviations from PSS (Φ>1). The deviations observed under low NOx conditions (5–25 pptv) demonstrate a remarkable upward tendency in the Leighton ratio (used to characterize PSS) with increasing NOx mixing ratio and JNO2 intensity. It is a paradigm in atmospheric chemistry that OH largely controls the oxidation efficiency of the atmosphere. However, evidence is growing that for unpolluted low-NOx (NO + NO2) conditions the atmospheric oxidant budget is poorly understood. Nevertheless, for the very cleanest conditions, typical for the remote marine boundary layer, good model agreement with measured OH and HO2 radicals has been interpreted as accurate understanding of baseline photochemistry. Here we show that such agreement can be deceptive and that a yet unidentified oxidant is needed to explain the photochemical conditions observed at 40°–60° S over the Atlantic Ocean.
Pliocene Model Intercomparison Project (PlioMIP): experimental design and boundary conditions (Experiment 2)
Authors: Haywood A. M. , Dowsett H. J. , Robinson M. M. , Stoll D. K. , Dolan A. M. , Lunt D. J. , Otto-Bliesner B. , Chandler M. A.
Published: March 2011

Abstract. The Palaeoclimate Modelling Intercomparison Project has expanded to include a model intercomparison for the mid-Pliocene warm period (~3.3 to 3.0 million yr ago). This project is referred to as PlioMIP (Pliocene Model Intercomparison Project). Two experiments have been agreed and together compose phase 1 of PlioMIP. The first (Experiment 1) is being performed with atmosphere-only climate models. The second (Experiment 2) is utilising fully coupled ocean-atmosphere climate models. Following on from the publication of the experimental design and boundary conditions for Experiment 1 in Geoscientific Model Development, this short paper provides the necessary description of differences and/or additions to the experimental design for Experiment 2.
The economic value of drought information for water management under climate change: a case study in the Ebro basin
Authors: Quiroga S. , Garrote L. , Iglesias A. , Fernández-Haddad Z. , Schlickenrieder J. , de Lama B. , Mosso C. , Sánchez-Arcilla A.
Published: March 2011

Abstract. Drought events in the Mediterranean are likely to increase in frequency, duration and intensity due to climate change, thereby affecting crop production. Information about drought is valuable for river basin authorities and the farmers affected by their decisions. The economic value of this information and the resulting decisions are of interest to these two stakeholder groups and to the information providers. Understanding the dynamics of extreme events, including droughts, in future climate scenarios for the Mediterranean is being improved continuously. This paper analyses the economic value of information on drought events taking into account the risk aversion of water managers. We consider the effects of drought management plans on rice production in the Ebro river basin. This enables us to compute the willingness to compensate the river basin authority for more accurate information allowing for better decision-making. If runoff is reduced, river basin planners can consider the reduction of water allocation for irrigation in order to eliminate the risk of water scarcity. Alternately, river basin planners may decide to maintain water allocation and accept a reduction of water supply reliability, leaving farmers exposed to drought events. These two alternatives offer different risk levels for crop production and farmers' incomes which determine the value of this information to the river basin authority. The information is relevant for the revision of River Basin Management Plans of the Water Framework Directive (WFD) within the context of climate change.
Changes in seasonal snow cover in Hindu Kush-Himalayan region
Authors: Gurung D. R. , Kulkarni A. V. , Giriraj A. , Aung K. S. , Shrestha B. , Srinivasan J.
Published: March 2011

Abstract. The changes in seasonal snow covered area in the Hindu Kush-Himalayan (HKH) region have been examined using Moderate – resolution Imaging Spectroradiometer (MODIS) 8-day standard snow products. The average snow covered area of the HKH region based on satellite data from 2000 to 2010 is 0.76 million km2 which is 18.23% of the total geographical area of the region. The linear trend in annual snow cover from 2000 to 2010 is −1.25±1.13%. This is in consistent with earlier reported decline of the decade from 1990 to 2001. A similar trend for western, central and eastern HKH region is 8.55±1.70%, +1.66% ± 2.26% and 0.82±2.50%, respectively. The snow covered area in spring for HKH region indicates a declining trend (−1.04±0.97%). The amount of annual snowfall is correlated with annual seasonal snow cover for the western Himalaya, indicating that changes in snow cover are primarily due to interannual variations in circulation patterns. Snow cover trends over a decade were also found to vary across seasonally and the region. Snow cover trends for western HKH are positive for all seasons. In central HKH the trend is positive (+15.53±5.69%) in autumn and negative (−03.68±3.01) in winter. In eastern HKH the trend is positive in summer (+3.35±1.62%) and autumn (+7.74±5.84%). The eastern and western region of HKH has an increasing trend of 10% to 12%, while the central region has a declining trend of 12% to 14% in the decade between 2000 and 2010. Snow cover depletion curve plotted for the hydrological year 2000–2001 reveal peaks in the month of February with subsidiary peaks observed in November and December in all three regions of the HKH.
Prevalence, Clinical Characteristics, and Causes of Vision Loss in Patients with Ocular Toxoplasmosis
Authors: London Nikolas J.S. , Hovakimyan Anna , Cubillan Leo D.P. , Siverio Carlos D. , Cunningham Emmett T.
Published: March 2011

Purpose.

To describe the prevalence, demographics, clinical features, and contributors to vision loss at presentation in a large cohort of patients with ocular toxoplasmosis seen at a tertiary referral center in northern California.

Methods.

A retrospective review of the charts of 233 patients with ocular toxoplasmosis examined over 24 years.

Results.

Ocular toxoplasmosis was diagnosed in 233 (8.4%) of 2761 patients with uveitis. The mean age at presentation was 27.2 years. Patients with ocular toxoplasmosis were more likely to be young (p<0.01), male (p<0.001), and Latino (p<0.001) as compared with patients in the entire uveitis cohort. At presentation, 159 patients (68.2%) had active disease, which was unilateral in all but one. Among the 160 eyes with active disease, 145 (90.6%) presented with a focal retinochoroiditis, 57.2% of which had an adjacent retinochoroidal scar. Atypical presentations occurred in 11 patients (6.9%). Of eyes with active disease, the main contributors to vision loss at presentation were intraocular inflammation (74.8%) and macular involvement (24.3%), whereas in eyes with inactive lesions the main contributors to vision loss were macular scar formation (67.9%) and amblyopia (11.3%). Younger age was the single significant predictor of macular involvement.

Conclusions.

Ocular toxoplasmosis is a common cause of uveitis. Our patients were more likely than general uveitis patients to be young, male, and Latino, often having emigrated from Mexico or Central or South America. The most common contributors to decreased vision in eyes with active lesions were inflammation and macular involvement, whereas in eyes with inactive lesions they were macular scar formation and amblyopia.
Adhesion of Biocompatible and Biodegradable Micropatterned Surfaces
Authors: Kaiser Jessica S. , Kamperman Marleen , De Souza Emerson J. , Schick Bernhard , Arzt Eduard
Published: March 2011

We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PLGA) polymer systems. Micropatterned and non-patterned compliant PDMS did not show significant differences in adhesion on compliant mice ear skin or on gelatin-glycerin model substrates. However, adhesion measurements for micropatterned stiff PLGA on compliant gelatin-glycerin model substrates showed significant enhancement in pull-off strengths compared to non-patterned controls.
Hyaluronic Acid-Based Hydrogels Crosslinked by Copper-Catalyzed Azide-Alkyne Cycloaddition with Tailorable Mechanical Properties
Authors: Piluso Susanna , Hiebl Bernhard , Gorb Stanislav N. , Kovalev Alexander , Lendlein Andreas , Neffe Axel T.
Published: March 2011

Biopolymers of the extracellular matrix are attractive starting materials for providing degradable and biocompatible biomaterials. In this study, hyaluronic acid-based hydrogels with tunable mechanical properties were prepared by the use of copper- catalyzed azide-alkyne cycloaddition (known as “click chemistry”). Alkyne-functionalized hyaluronic acid was crosslinked with linkers having two terminal azide functionalities, varying crosslinker density as well as the lengths and rigidity of the linker molecules. By variation of the crosslinker density and crosslinker type, hydrogels with elastic moduli in the range of 0.5–4 kPa were prepared. The washed materials contained a maximum of 6.8 mg copper per kg dry weight and the eluate of the gel crosslinked with diazidostilbene did not show toxic effects on L929 cells. The hyaluronic acid-based hydrogels have potential as biomaterials for cell culture or soft tissue regeneration applications.
Polyurethanes as Supports for Human Retinal Pigment Epithelium Cell Growth
Authors: Da Silva Gisele R. , Armando Da S. C. , Saliba Juliana B. , Berdugo Marianne , Goldenberg Brigitte T. , Naud Marie C. , Ayres Eliane , Oréfce Rodrigo L. , Cohen Francine B.
Published: March 2011

Purpose

The transplant of retinal pigment epithelium (RPE) cells on supports may well be an effective therapeutic approach to improve the visual results of patients with age-related macular degeneration. In this study, two biodegradable polyurethanes were investigated as supports for human RPE cells (ARPE-19).

Methods

Polyurethane aqueous dispersions based on poly(caprolactone) and/or poly(ethylene glycol) as soft segments, and isophorone diisocyanate and hydrazine as hard segments were prepared. Polyurethane films were produced by casting the dispersions and allowing them to dry at room temperature for one week. The ARPE-19 cells were seeded onto the polyurethane films and they were investigated as supports for in vitro adhesion, proliferation, and uniform distribution of differentiated ARPE-19 cells. Additionally, the in vivo ocular biocompatibility of the polyurethane films was evaluated.

Results

The RPE adhered to and proliferated onto the polyurethane supports, thus establishing cellPUD surface interactions. Upon confluence, the cells formed an organized monolayer, exhibited a polygonal appearance, and displayed actin filaments which ran along the upper cytoplasm. At 15 days of seeding, the occluding expression was confirmed between adjacent cells, representing the barrier functionality of epithelial cells on polymeric surfaces and the establishment of cell-cell interactions. Results from the in vivo study indicated that polyurethanes exhibited a high degree of short-term intraocular biocompatibility.

Conclusions

Biodegradable polyurethane films display the proper mechanical properties for an easy transscleral-driven subretinal implantation and can be considered as biocompatible supports for a functional ARPE-19 monolayer.
Multivalent, Biodegradable Polyglycerol Hydrogels
Authors: Steinhilber Dirk , Haag Rainer , Sisson Adam L.
Published: March 2011

In this paper we describe the preparation of disulfide crosslinked polyglycerol hydrogels by the ring-opening crosslinking polymerization of glycerol and polyethylene glycol-based polyepoxides and Na2S2. Multivalent polyglycerol hydrogels were prepared by acid-catalyzed hydrolysis of remaining epoxide functionalities. Additionally, a near infrared fluorescent dye was encapsulated in the hydrogel network. Our hydrogels show complete degradation in reducing environments and a controlled release of the fluorescence dye was observed. These hydrogels are interesting scaffolds for bioactive substances, which can be released, triggered by the hydrogel degradation.
Degradable Polymers in Medicine: Updating Strategies and Terminology
Authors: Vert Michel
Published: March 2011

Today, the field of biodegradable materials and devices attracts polymer scientists and healthcare professionals in surgery, dentistry, pharmacology and regenerative medicine. More than one thousand papers are published per year in the literature, while the topic appears in the title of many patents. However, the number of devices or systems that have been successfully developed for clinical and commercial uses is still very small. A critical examination of the literature suggests two main reasons for this. Firstly, biodegradation is generally considered the main goal to reach, so that academic strategies do not take into account the criteria specific to targeted applications. Secondly, the term “biodegradable” is too often used inappropriately and creates confusion. This paper aims specifically to remind readers of the complexity of in vivo polymer degradation and the need for an enriched and universally recognized terminology in order to clearly distinguish between the various possible stages, and to enable clear communication between specialists when discussing related issues. It also emphasizes the need for any novel polymer to be well characterized and to include application-specific requirements in the research strategy from the very beginning, since these determine its potential clinical and commercial uses. Based on more than a decade of efforts, this would appear to be paramount in order to provide a chance for novel polymers to reach the market.
Shape-Memory Properties and Degradation Behavior of Multifunctional Electro-Spun Scaffolds
Authors: Kratz Karl , Habermann Ronny , Becker Tino , Richau Klaus , Lendlein Andreas
Published: March 2011

Multifunctional polymer-based biomaterials, which combine degradability and shape-memory capability, are promising candidate materials for the realization of active self-anchoring implants. In this work we explored the shape-memory capability as well as the hydrolytic and enzymatic in vitro degradation behavior of electrospun scaffolds prepared from a multiblock copolymer, containing hydrolytically degradable poly(p-dioxanone) (PPDO) and poly(∊-caprolactone) (PCL) segments, which we have named PDC.

Electro-spun PDC scaffolds with an average deposit thickness of 80 ± 20 μm and a porosity in the range from 70% to 80% were prepared, where the single fiber diameter was around 3 μm. Excellent shape-memory properties were achieved with high recovery rate (Rr) values in the range of Rr = 92% to 98% and a recovery stress of σmax = 4.6 MPa to 5.0 MPa. The switching temperature (Tsw) and the characteristic temperature obtained under constant strain recovery conditions (Tσ, max) were found in the range from 32°C to 35°C, which was close to the melting temperature (Tm,PCL) associated to the poly(∊-caprolactone) domains.

A linear mass loss was observed in both hydrolytic and enzymatic degradation experiments. The mass loss was substantially accelerated, in enzymatic degradation when Pseudomonas cepacia lipase was added, which was reported to accelerate the degradation of PCL. During hydrolytic degradation a continuous decrease in elongation at break (∊B) from ∊B = 800% to 15% was observed in a time period of 92 days, while in enzymatic degradation experiments a complete mechanical failure was obtained after 4 days.
Near-Infrared Dye-Loaded Plga Nanoparticles Prepared by Spray Drying for Photoacoustic Applications
Authors: Kohl Yvonne , Kaiser Christian , Bost Wolfgang , Stracke Frank , Thielecke Hagen , Wischke Christian , Lendlein Andreas , Kratz Karl , Lemor Robert
Published: March 2011

Introduction

Nanoparticulate contrast agents are of great interest for diagnostic applications with high resolution in medicine. Here we present polymer-based degradable nanoparticles exhibiting a near infrared (NIR) absorption suitable for photoacoustic imaging.

Methods

The nanoparticles were prepared by incorporation of indocyanine green (ICG) as NIR dye in poly[(rac-lactide)-co-glycolide] (PLGA) via an optimized spray drying process. By application of a multi-step centrifugation protocol, two different size fractions were achieved. The biocompatibitilty of the nanoparticles was tested in 2D cell cultures (human hepatocarcinoma cells and monkey kidney cells) using WST-1, BrdU and LDH assay.

Results

Spherical particles were obtained with a good yield (>81%), showing a high NIR-dye encapsulation efficiency (>98%). By multi-step centrifugation, two different size fractions with a mean diameter of 640 nm and 390 nm were obtained. Cytotoxicity studies of the synthesized ICG-loaded PLGA particles were performed. No cytotoxic effect on metabolic activity, proliferation, or membrane integrity was observed.

Conclusion

The high optical absorption at the relevant NIR-wavelength around 800 nm in combination with absence of cytotoxicity qualifies the ICG-loaded PLGA particles as promising candidates for degradable photoacoustic contrast agents.
Biofabrication with Biopolymers and Enzymes: Potential for Constructing Scaffolds from Soft Matter
Authors: Wu Li-Qun , Bentley William E. , Payne Gregory F.
Published: March 2011

Purpose

Regenerative medicine will benefit from technologies capable of fabricating soft matter to have appropriate architectures and that provide the necessary physical, chemical and biological cues to recruit cells and guide their development. The goal of this report is to review an emerging set of biofabrication techniques and suggest how these techniques could be applied for the fabrication of scaffolds for tissue engineering.

Methods

Electrical potentials are applied to submerged electrodes to perform cathodic and anodic reactions that direct stimuli-responsive film-forming polysaccharides to assemble into hydrogel films. Standard methods are used to microfabricate electrode surfaces to allow the electrical signals to be applied with spatial and temporal control. The enzymes mushroom tyrosinase and microbial transglutaminase are used to catalyze macromolecular grafting and crosslinking of proteins.

Results

Electrodeposition of the polysaccharides chitosan and alginate allow hydrogel films to be formed in response to localized electrical signals. Co-deposition of various components (e.g., proteins, vesicles and cells), and subsequent electrochemical processing allow the physical, chemical and biological activities of these films to be tailored. Enzymatic processing allows for the generation of stimuli-responsive protein conjugates that can also be directed to assemble in response to imposed electrical signals. Further, enzyme-catalyzed crosslinking of gelatin allows replica molding of soft matter to create hydrogel films with topological structure.

Conclusions

Biofabrication with biological materials and mechanisms provides new approaches for soft matter construction. These methods may enable the formation of tissue engineering scaffolds with appropriate architectures, assembled cells, and spatially organized physical, chemical and biological cues.
Characterization of Multiblock Copolymers by Chromatographic Techniques
Authors: N'Goma Patrick Yoba , Radke Wolfgang , Malz Frank , Ziegler Hans Jörg , Zierke Michael , Behl Marc , Lendlein Andreas
Published: March 2011

Multiblock copolymers (MBC) composed of blocks of poly(1,4-dioxanone) (PPDO) and poly(∊-caprolactone) (PCL) were investigated in order to gain information on the extend of chemical heterogeneity of the samples. A gradient chromatographic method was established allowing separation of purely PPDO- from purely PCL-containing chains. Application of the gradient to MBC made of PPDO- and PCL-diols connected by trimethylhexamethylene diisocyanate (TMDI) resulted in two well separated peaks which were analyzed by means of FTIR, 1H-NMR and pyrolysis GC-MS. It was shown that the first peak was composed to a large extent of PPDO and only lower amounts of PCL were incorporated. Conversely, the second peak consisted predominantly of PCL with only a minor fraction of PPDO. Thus, the MBCs having PPDO and PCL segments show an unexpected broad chemical heterogeneity.
Recent Progress in Multiferroic Magnetoelectric Composites: from Bulk to Thin Films (Adv. Mater. 9/2011)
Authors: Ma Jing , Hu Jiamian , Li Zheng , Nan Ce‐Wen
Published: March 2011

Multiferroic magnetoelectric composite systems such as ferromagnetic‐ferroelectric heterostructures have recently attracted an ever‐increasing interest and provoked a great number of research activities, driven by profound physics from coupling between ferroelectric and magnetic orders, as well as potential applications in novel multifunctional devices, such as sensors, transducers, memories, and spintronics. In this Review, we try to summarize what remarkable progress in multiferroic magnetoelectric composite systems has been achieved in most recent few years, with emphasis on thin films; and to describe unsolved issues and new device applications which can be controlled both electrically and magnetically.
Removable Directing Groups in Organic Synthesis and Catalysis
Authors: Rousseau Géraldine , Breit Bernhard
Published: March 2011

Directing groups have been widely used in recent years to achieve control over all aspects of reaction selectivity in a wide range of transformations involving transition‐metal catalysis and organometallic reagents. In cases when the existing functional group within a substrate is unsuited to achieve efficient intramolecular delivery of a reagent or catalyst, the specific introduction of an appropriately designed removable reagent‐directing group can be a solution to this problem. In this Review we give an overview of the state of the art in this area, including the stoichiometric and catalytic use of directing groups.
Anti‐Hepatitis B Virus Active Lactones from the Traditional Chinese Herb: Swertia mileensis
Authors: Geng Chang‐An , Wang Li‐Jun , Zhang Xue‐Mei , Ma Yun‐Bao , Huang Xiao‐Yan , Luo Jie , Guo Rui‐Hua , Zhou Jun , Shen Yong , Zuo Ai‐Xue , Jiang Zhi‐Yong , Chen Ji‐Jun
Published: March 2011

Swerilactones H–K (1–4), which are four novel lactones with an unprecedented C29 skeleton, were isolated from Swertia mileensis (Qing‐Ye‐Dan), an endemic Chinese herb used for treating viral hepatitis. Their structures were determined by extensive spectroscopic and X‐ray crystallographic diffraction analyses. Swerilactones H–K exhibit potent anti‐hepatitis B virus activity against HBV DNA replication with IC50 values ranging from 1.53 to 5.34 μM. For the first time, a plausible biogenetic pathway for swerilactones H–K, together with the previously reported swerilactones A–D is proposed. From a biogenetic point of view, swerilactones A–D are ascribed as secoiridoid dimers, and swerilactones H–K as secoiridoid trimers.
The association between radiographic response and overall survival in men with metastatic castration‐resistant prostate cancer receiving chemotherapy
Authors: Sonpavde Guru , Pond Gregory R. , Berry William R. , de Wit Ronald , Eisenberger Mario A. , Tannock Ian F. , Armstrong Andrew J.
Published: March 2011

BACKGROUND:

In men with metastatic castration‐resistant prostate cancer (CRPC), the association of measurable tumor responses with overall survival (OS) is unknown. The authors retrospectively evaluated the TAX327 phase 3 trial to study this relation.

METHODS:

Eligible patients for this analysis included those with World Health Organization (WHO)‐defined measurable metastatic disease randomized to receive either docetaxel or mitoxantrone. OS was estimated by using the Kaplan‐Meier method, and the prognostic relation of WHO‐defined radiologic response with OS was performed by using Cox proportional hazards regression. Landmark analyses evaluated survival from baseline and at 2, 3, 4, and 6 months after baseline.

RESULTS:

Four hundred twelve patients enrolled on the TAX327 trial had measurable tumors. Thirty‐seven patients exhibited a complete or partial objective response (CR/PR, 9.0%), 116 had stable disease (SD, 28.2%), 99 had progressive disease (PD, 24%) and 160 (38.8%) did not have a after‐baseline objective assessment. Partial responders demonstrated longer median OS (29.0 months) than patients with SD (22.1 months) or those with PD (10.8 months) or those who were not assessed (12.7 months). These results remained after landmark analysis. The authors found a significant association between ≥30% prostate‐specific antigen (PSA) declines and radiologic response, with ≥30% PSA declines occurring in all patients with CR/PR, 79.8% of patients with SD, and 34.4% with PD. Radiologic response remained a significant but modest post‐treatment prognostic factor for OS after adjusting for treatment, pain response, and ≥30% PSA decline (P = .009).

CONCLUSIONS:

In men with metastatic CRPC and measurable disease receiving chemotherapy, objective tumor response was prognostic for OS and appeared to complement PSA assessment. Cancer 2011. © 2011 American Cancer Society.
A comparative analysis of the characteristics and images of costume colors in the traditional plays of Korea, China, and Japan
Authors: Lee Mi Suk , Sa Jin Kang , Chung Kyung Hee
Published: March 2011

The purpose of this study was to analyze quantitatively the characteristics and images of costume colors in the traditional plays of Korea, China, and Japan. The study focused on the Korean Masque, Beijing Opera, and Kabuki costume colors based on a selection of 1135 color samples. The collected source data were selected by extracting digital color data by using the Eyedropper Tool of Photoshop 7.0. The RGB color data were transformed to H V/C and the attributes of hue and tone were analyzed. Color images were analyzed with the color image scales of IRI Color Design Institute and Shigenobu Kobayashi to increase the validity of the evaluated images. As a result, the “five element colors (red, yellow, purple–blue (PB), white, and black)” from the theory of “Yin‐Yang Wu‐Xing” were used in the common stage costume colors of the Korean Masque, Beijing Opera, and Kabuki. Red, a preferred Asian color, was used most frequently in the costumes of these three traditional plays. A comparison of the traditional stage costume colors in the three northeast Asian countries revealed a difference in tones rather than in hues. First, the Korean Masque frequently used white in accordance with the tradition of white‐clad people and the cultural view of colors in which natural colors were preferred. Additionally, in the Masque, Koreans used colors based on the theory of Yin‐Yang Wu‐Xing with high‐chroma tones. On the other hand, the Beijing Opera exhibited the gorgeous and strong color images of China, by adopting high‐chroma colors in the Five Element Color: R, Y, PB, white, and black. Last, in the Kabuki costumes, a variety of white, black, dull, light, dark, strong, vivid, deep, bright, and grayish tones played an important role in showing various color images. The costume color images of the traditional plays of the three countries revealed that all shared the use of dynamic, springy/casual, and gorgeous images in the strong contrast of five element colors. Regarding the differences, the Korean Masque exhibited natural images in favor of natural colors, whereas the Kabuki displayed modern, decent/formal images by using dull, dark, and grayish colors. The study results suggested that the three countries commonly used five element colors from the theory of Yin‐Yang Wu‐Xing, but that their color images differed in terms of the tones used and the techniques for color combination. These results reflect that colors in the traditional costumes of the three countries are affected by their cultural codes, thereby representing the characteristics ofcertain peoples and cultural circles. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011
Strategic Corporate Responsibility in the Food Chain
Authors: Heikkurinen Pasi , Forsman‐Hugg Sari
Published: February 2011

This paper explores how food chain responsibility can be connected to strategy. The aim is to identify how strategic corporate responsibility (CR) intentions are in the Finnish food chain and analyse how competitiveness could be enhanced and sustained with strategic CR. The theoretical framework is built on a contextual definition from a resource‐based view. A multiple case study method was deployed and the data were collected through 20 semi‐structured interviews. It was found that the case companies aim at increasing their chain's competitiveness with CR. The food chain responsibility can be connected to strategy with varying depth and breadth. This results in four types of strategic CR combinations, namely: beyond‐responsive & holistic; beyond‐responsive & arrowhead; responsive & holistic; and responsive & arrowhead. The strategic CR combination that is rare, inimitable, and for which competitors cannot find substitutes, can yield a sustained competitive advantage and above‐normal economic performance. Copyright © 2010 John Wiley & Sons, Ltd. and ERP Environment.
Chemoselective Aerobic Diol Oxidation by Palladium(II)–Pyridine Catalysis
Authors: Bettucci Lorenzo , Bianchini Claudio , Filippi Jonathan , Lavacchi Alessandro , Oberhauser Werner
Published: March 2011

Neutral and cationic palladium complexes that bear pyridine ligands [i.e., pyridine (Py), 4‐ethylpyridine (4‐EtPy) and 2,4,6‐trimethylpyridine (2,4,6‐Me3Py)] have been isolated and characterized in solution by 1H and 13C{1H} NMR spectroscopy, cyclic voltammetry (CV) and in the solid state by elemental analysis and single‐crystal structure analysis. All palladium compounds have been scrutinized as a precursor to catalyze the aerobic oxidation of diols either in the presence or in the absence of an external base (i.e., K2CO3). As a result, the chemoselective production of the corresponding hydroxy ketones has been achieved. The bis‐cationic palladium complex of the formula [Pd(4‐EtPy)4](OTs)2 (OTs = p‐toluenesulfonate) [5b(OTs)2] emerged as the most promising precursor; it outperformed the neutral precursor that consisted of trans‐[Pd(OAc)2(4‐EtPy)2] (OAc = acetate) and 4‐EtPy [3b/2(4‐EtPy)] (2 mol‐equiv.). An operando high‐pressure (HPNMR) spectroscopic study with the precursor 5b(OTs)2 combined with the results obtained from catalytic reactions has provided insight into the catalytic mechanism that is operative in 5b(OTs)2‐catalyzed aerobic diol oxidation reactions.
Equations for the near‐surface mass flux density profile of wind‐blown sediments
Authors: Dong Zhibao , Lu Junfeng , Man Duoqing , Lv Ping , Qian Guanqiang , Zhang Zhengcai , Luo Wanyin
Published: February 2011

The erosion of sediment by wind and the resulting mass flux density profile is thought to be described by a mathematical function that bears information on the mechanisms responsible for the movement of individual particles by the wind, and such functions have been studied extensively. In this study several functions are evaluated that have been proposed to describe the variation in mass flux density with height of wind‐blown sediment, with the flux containing a mixture of particles in suspension and saltation, based on detailed field data at four land types in the Minqin area of north‐western China, where severe wind erosion occurs. High‐resolution mass flux density measurements at 50 heights, collected at 20 mm intervals to a height of 1 m above the surface, were obtained using vertically segmented samplers. Three kinds of functions fit the measured flux density profiles reasonably well, but a three‐parameter modified exponential function is preferred because it contains fewer coefficients to be defined and provides a reasonably good fit to the measured mass flux density profiles. This and previous conclusions suggest that the decay with height of mass flux density of sediments dominated by saltation particles as in the present study tends to follow a modified exponential function law, but a modified power function law replaces the modified exponential function law when the height extends to a level high enough to be dominated by suspension particles. Copyright © 2011 John Wiley & Sons, Ltd.
Variable self‐similar sinuosity properties within simulated river networks
Authors: Gaucherel Cédric , Salomon Ludovic , Labonne Jacques
Published: February 2011

River networks have been shown to obey power scaling laws and to follow self‐organization principles. Their self‐similar (fractal) properties open a path to relate small scale and large scale hydrological processes, such as erosion, deposition or geological movements. However, the existence of a self‐similar dimension has only been checked using either the whole channel network or, on the contrary, a single channel link. No study has explicitly addressed the possible spatial variation of the self‐similar properties between these two extreme geomorphologic objects. Here, a new method based on self‐similarity maps (SSM) is proposed to spatially explore the stream length self‐similar dimension Dl within a river network. The mapping principle consists in computing local self‐similar dimensions deduced from a fit of stream length estimations using increasing divider sizes. A local uncertainty related to the fit quality is also computed and localized on every stream. To assess the efficiency of the approach, contrasted river networks are simulated using optimal channel networks (OCN), where each network is characterized by an exponent γ conditioning its overall topology. By building SSM of these networks, it is shown that deviations from uniform self‐similarity across space occur. Depending on the type of network (γ parameter), these deviations are or are not related to Strahler's order structure. Finally, it is found numerically that the structural averaged stream length self‐similar dimension Dl is closely related to the more functional γ parameter. Results form a bridge between the studies on river sinuosity (single channel) and growth of channel networks (watershed). As for every method providing spatial information where they were lacking before, the SSM may soon help to accurately interpret natural networks and help to simulate more realistic channel networks. Copyright © 2011 John Wiley & Sons, Ltd.