bluuebunny/crossref_metadata_2025 huggingface dataset:
Lichtinduzierte Klickreaktionen
Authors: Tasdelen Mehmet Atilla , Yagci Yusuf
Published: May 2013

Die räumliche und zeitliche Kontrolle über chemische und biologische Prozesse zur Feinabstimmung von Reaktionsprodukten und zum Erreichen ortsspezifischer Selektivität ist eines der spannendsten Gebiete der modernen Wissenschaft. Ziel und Herausforderung für den Synthesechemiker ist es, selektive und effiziente Reaktionen zu entwickeln, die zur Herstellung nutzbarer Moleküle in verschiedenartigen Matrizen geeignet sind. In neueren Untersuchungen wurde Licht als wertvolles “Werkzeug” erkannt, mit dem bestimmt werden kann, wo, wann und in welchem Ausmaß ein Prozess gestartet oder abgebrochen wird. Dieser Kurzaufsatz erläutert die grundlegenden Aspekte lichtinduzierter Klickreaktionen, zeigt die Anwendungen dieser Umsetzungen in verschiedenen Forschungsgebieten auf und untersucht das Potenzial dieser Methode für das Studium biomolekularer Systeme.
Light‐Induced Click Reactions
Authors: Tasdelen Mehmet Atilla , Yagci Yusuf
Published: May 2013

Spatial and temporal control over chemical and biological processes, both in terms of “tuning” products and providing site‐specific control, is one of the most exciting and rapidly developing areas of modern science. For synthetic chemists, the challenge is to discover and develop selective and efficient reactions capable of generating useful molecules in a variety of matrices. In recent studies, light has been recognized as a valuable method for determining where, when, and to what extent a process is started or stopped. Accordingly, this Minireview will present the fundamental aspects of light‐induced click reactions, highlight the applications of these reactions to diverse fields of study, and discuss the potential for this methodology to be applied to the study of biomolecular systems.
Preparation of highly dispersed expanded graphite/polypropylene nanocomposites via low temperature processing
Authors: Fasihi Mohammad , Garmabi Hamid , Ghaffarian Seyed Reza , Ohshima Masahiro
Published: May 2013

A new processing scheme for preparing highly dispersed expanded graphite/polypropylene (PP) nanocomposites has been developed in this study. To improve the degree of dispersion of graphite throughout the PP domains, the solid‐state milling has been performed followed by low‐temperature melt processing in the range of melting point (Tm) and the crystallization temperature (Tc) of PP. The solid‐state milling followed by low‐temperature melt mixing could drastically improve the degree of graphite dispersion in the matrix. As a result, the well‐dispersed graphite/PP nanocomposite supported by transmission electron microscopy (TEM) exposed a higher degree of plastic deformation and energy to break in the tensile test. The higher degree of graphite dispersion achieved in this scheme was due to the increase of local shear force near the crystalline domains formed during low‐temperature melt mixing. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1834–1839, 2013
Identification by GC‐O and GC‐MS of new odorous compounds in natural rubber
Authors: Juntarachat Niramol , Bouvier Nicolas , Lepoutre Jean‐Paul , Roland Aurélie , Sainte‐Beuve Jérôme , Granet Françoise , Salmon Jean‐Michel , Rigou Peggy , Chalier Pascale
Published: May 2013

Natural rubber products emit malodourous compounds, which can contaminate the air and water of the inhabited surroundings of the production factories. Analytical methods such as SPME coupled with GC‐MS and GC‐O‐FID were used to elucidate the composition and olfactory impact of volatile compounds released from two various grades of natural rubber submitted to different coagulation processes. Forty‐three volatile compounds were identified and amongst 16 of them that had never been reported. The volatile compounds belonged to different chemical classes and were the result of enzymatic and microbial action as well as thermal degradation. Among the new compounds identified, a terpene (limonene), benzyl derivatives, or trimethylamine were found in both grades of natural rubber. In contrary phenyl acids, fatty acid esters, or 2,6 dimethoxyphenol were specific to one grade of natural rubber and may result from the coagulation process. The use of GC‐O analysis emphasized the contribution of short‐chain fatty acids to the malodorous odour generated but also evidenced the participation of trimethylamine and 2,6 dimethoxyphenol. At last, it was demonstrated that the presence of phenyl acids in one natural rubber could partially mask the obnoxious odour. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1863–1872, 2013
Synthesis and Biological Evaluation of Novel Bromophenol Derivatives as Carbonic Anhydrase Inhibitors
Authors: Akbaba Yusuf , Balaydın Halis Türker , Menzek Abdullah , Göksu Süleyman , Şahin Ertan , Ekinci Deniz
Published: May 2013

Here, we provide an alternative synthesis of the natural bromophenol 3,4‐dibromo‐5‐(2,3‐dibromo‐4,5‐dihydroxybenzyl)‐6‐(ethoxymethyl)benzene‐1,2‐diol (3) and the first synthesis of (4,5‐dihydroxy‐2‐methylphenyl)(3,4‐dihydroxyphenyl)methanone (18) and its brominated derivatives 19–21. The compounds were characterized and tested against the two most studied members of the pH regulatory enzyme family, carbonic anhydrase (CA). The inhibitory potencies of the novel compounds and two natural bromophenols 2, 3 were analyzed at the human isoforms hCA I and hCA II as targets and the KI values were calculated. The KI values of the novel compounds were measured in the range of 13.7–32.7 µM for the hCA I isozyme and 0.65–1.26 µM for the hCA II isozyme. The structurally related compound 14 was also tested in order to understand the structure–activity relationship, and the clinically used sulfonamide acetazolamide (AZA) was tested for comparison reasons. All of the compounds exhibited competitive inhibition with 4‐nitrophenylacetate as substrate. The compounds showed strong inhibitory activity against hCA I, being more effective as compared to the clinically used AZA (KI: 36.2 µM), but rather less activity against hCA II.
A sensitive method for the determination of levamisole in serum by electrochemiluminescence
Authors: Xiao Ying , Li Jianping , Fu Cong
Published: May 2013

A novel method was developed for the determination of levamisole by electrochemiluminescence. The method was based on electrochemiluminescence signal enhancement produced by Ru(bpy)32+, which reacted with the tertiary amine group of levamisole on a platinum electrode in 12 mmol/L borate buffer (pH 9). A linear relationship between the luminous intensity and concentration of levamisole in the range 0–1 × 10–7 mol/L was obtained and the detection limit was 1.76 × 10–11 mol/L. The method is sensitive, selective, simple and convenient. The method has been successfully applied to the analysis of levamisole in serum. Copyright © 2013 John Wiley & Sons, Ltd.
Review of the quantitative analysis of cholesteryl ester transfer protein inhibitors
Authors: Mullangi Ramesh , Srinivas Nuggehally R.
Published: May 2013

Clinical investigations of choleteryl ester transfer protein (CETP) inhibitors are still underway owing to its promise of reducing risk factors in patients with cardiovascular disease. Although several CETP inhibitors have reached late phase clinical testing, there is a paucity of publications that describe the determination of various CETP inhibitors in human and/or animal matrices. An attempt is made in this review to collate bioanalytical information on three CETP inhibitors (anacetrapib, dalcetrapib and torcetrapib) and its metabolites, where data were available and reported. As elaborated in the review, owing to numerous structural issues coupled with chromatography/detection challenges indigenous to the class, a wide array of analytical tools, detection systems, interesting process manipulations and separation nuances have been utilized for the quantitative analysis of CETP inhibitors and applicable metabolites. Copyright © 2013 John Wiley & Sons, Ltd.
José María Vargas (1786–1854): Reformer of anatomical studies in Venezuela
Authors: Reverón Rafael Romero
Published: May 2013

José María Vargas (1786–1854): Venezuelan medical doctor, surgeon, optician, anatomist, chemist, botanist, professor, geologist, mineralogist, and mathematician. Second President of Venezuela (1835–1836), First republican dean, he reformed medicine studies in 1827 establishing human anatomical dissection in the Universidad Central de Venezuela where he taught human anatomy between 1827 and 1853 along with surgery and chemistry. In 1838, he wrote Curso de Lecciones y demostraciones Anatómicas, the first book on the subject printed in Venezuela for the teaching of human anatomy. Clin. Anat. 27:150–153, 2014. © 2013 Wiley Periodicals, Inc.
Simulation‐based uncertainty quantification of human arterial network hemodynamics
Authors: Chen Peng , Quarteroni Alfio , Rozza Gianluigi
Published: May 2013

This work aims at identifying and quantifying uncertainties from various sources in human cardiovascular system based on stochastic simulation of a one‐dimensional arterial network. A general analysis of different uncertainties and probability characterization with log‐normal distribution of these uncertainties is introduced. Deriving from a deterministic one‐dimensional fluid–structure interaction model, we establish the stochastic model as a coupled hyperbolic system incorporated with parametric uncertainties to describe the blood flow and pressure wave propagation in the arterial network. By applying a stochastic collocation method with sparse grid technique, we study systemically the statistics and sensitivity of the solution with respect to many different uncertainties in a relatively complete arterial network with potential physiological and pathological implications for the first time. Copyright © 2013 John Wiley & Sons, Ltd.
Direct interaction between cholera toxin and dendritic cells is required for oral adjuvant activity
Authors: Gustafsson Tobias , Hua Yeu‐Jiann , Dahlgren Madelene W. , Livingston Megan , Johansson‐Lindbom Bengt , Yrlid Ulf
Published: May 2013

Cholera toxin (CT) binds to GM1‐ganglioside receptors present on all nucleated cells. Despite this, it is a very potent mucosal adjuvant that has a dramatic impact on immune cells, as well as nerve and epithelial cells, causing diarrhea. This fact has hampered our understanding of whether the adjuvanticity of CT is direct or indirect, as cells that bind CT may or may not be involved in its adjuvant function. The mucosal barrier is maintained by tight junctions between epithelial cells but dendritic cells (DCs) can protrude luminal dendrites. Here we investigated which cells are involved in the immune augmenting effect of CT. We explored oral immunizations with ovalbumin (OVA) and CT in bone marrow chimeric mice deficient in GM1‐ganglioside in defined cellular subsets. We found that chimeric mice lacking GM1 in nonhematopoietic cells, including epithelial cells, mounted an unaltered intestinal IgA response. In contrast, chimeric mice lacking GM1‐expressing hematopoietic cells in general, or specifically GM1‐expressing conventional DCs (cDCs), largely failed to elicit anti‐OVA adaptive immune responses. Therefore, the adjuvanticity of CT does not require epithelial activation, but is directly dependent on the binding of CT to gut cDCs via GM1‐ganglioside. These results could have important implications for the generation of novel oral adjuvants.
Ionic Liquids Based on the 7‐Azabicyclo[2.2.1]heptane Skeleton: Synthesis and Properties
Authors: De Vos Nils , Maton Cedric , De Vreese Peter , Brooks Neil R. , Binnemans Koen , Stevens Christian V.
Published: May 2013

Based on a previously developed method for the synthesis of epibatidine analogues, a series of new ionic liquids, based on the 7‐azabicyclo[2.2.1]heptane skeleton, have been synthesized. The chemical and physical properties of the ionic liquids with bis(trifluoromethylsulfonyl)imide (Tf2N) and dicyanamide [N(CN)2] anions were investigated and they were found to exhibit very good electrochemical and thermal stabilities.
Dehydrogenation of Perfluoroalkyl Ket­ones by Using a Recyclable Oxoammonium Salt
Authors: Hamlin Trevor A. , Kelly Christopher B. , Leadbeater Nicholas E.
Published: May 2013

A novel dehydrogenation reaction of perfluoroalkyl ketones by the oxoammonium salt 4‐acetylamino‐2,2,6,6‐tetramethylpiperidine‐1‐oxoammonium tetrafluoroborate (4‐NHAc‐TEMPO+BF4–, Bobbitt's salt,1) is described. The reaction proceeds under mildly basic conditions and appears to be unique to perfluoroalkyl ketones. A proposed mechanism for this unusual transformation is given. The byproduct of the reaction, 4‐acetylamino‐2,2,6,6‐tetramethyl‐1‐piperidinyloxy (1a), can easily be recovered and used to regenerate the oxoammonium salt.
Energy‐efficient multicast routing scheme for wireless sensor networks
Authors: Tang Xiaolan , Pu Juhua , Gao Yang , Xiong Zhang , Weng Yuelong
Published: May 2013

This paper presents a novel energy‐efficient multicast routing scheme for wireless sensor networks, named extended multicast routing scheme with pruning and energy balancing (E‐MPEB) to disseminate data through layered multicast trees with high efficiency and low power consumption. E‐MPEB uses pruning and energy balancing algorithms to save energy and balance load. Especially, it supports multisource multicast and multiple multicast tasks. In multisource multicast, we propose dense tree construction and conjunctive pruning algorithms to minimise total transmission in the network. We increase the number of children having the same parent to improve transmission efficiency and turn more nodes into sleep. In multiple multicast tasks, we propose sharing node avoidance algorithm to separate trees for different multicast tasks. This separation reduces transmission congestion at sharing nodes and balances total energy consumption. Formal validations and simulations evaluate the performance of E‐MPEB, which show that E‐MPEB has a distinct advantage over others in both reducing and balancing energy consumption. Copyright © 2013 John Wiley & Sons, Ltd.
A combined vacuum crushing and sieving (CVCS) system designed to determine noble gas paleotemperatures from stalagmite samples
Authors: Vogel Nadia , Brennwald Matthias S. , Fleitmann Dominik , Wieler Rainer , Maden Colin , Süsli Andreas , Kipfer Rolf
Published: May 2013

This paper presents a novel extraction device for water and noble gases from speleothem samples for noble gas paleotemperature determination. The “combined vacuum crushing and sieving (CVCS) system” was designed to reduce the atmospheric noble gas contents from air inclusions in speleothem samples by up to 2 orders of magnitude without adsorbing atmospheric noble gases onto the freshly produced grain surfaces, a process that had often hampered noble gas temperature (NGT) determination in the past. We also present the results from first performance tests of the CVCS system processing stalagmite samples grown at a known temperature. This temperature is reliably reproduced by the NGTs derived from Ar, Kr, and Xe extracted from the samples. The CVCS system is, therefore, suitable for routine determinations of accurate NGTs. In combination with stalagmite dating, these NGTs will allow reconstructing past regional temperature evolutions, and also support the interpretation of the often complex stable isotope records preserved in the stalagmites' calcite.
Intraseasonal variations in the surface layer heat balance of the central equatorial Indian Ocean: The importance of zonal advection and vertical mixing
Authors: McPhaden M. J. , Foltz G. R.
Published: May 2013

We examine the ocean mixed layer response to intraseasonal atmospheric forcing using moored time series data in the central equatorial Indian Ocean for October 2004 to March 2005, a period coincident with two active phases of the Madden‐Julian Oscillation (MJO). Both MJO events were accompanied by a sea surface temperature decrease that was partially the consequence of reduced net surface heat flux. In addition, during the first event in October–November 2004, advection by an enhanced Wyrtki Jet contributed substantial cooling, while during the second event in December 2004 to January 2005, vertical processes, most likely related to entrainment mixing, were pronounced. Heavy rainfall at the mooring location during the first event may have contributed to the formation of a 30–40 m thick barrier layer that limited turbulent vertical transfers between the mixed layer and the thermocline. There was no barrier layer present during the second event, which presumably allowed for much freer vertical turbulent exchanges.
Molecular‐targeted agents combination therapy for cancer: Developments and potentials
Authors: Li Feifei , Zhao Changqi , Wang Lili
Published: May 2013

Although chemotherapy has advanced into the era of targeted drugs, the antitumor efficacies of current therapies are limited, most likely because of the high degree of cancer clonal heterogeneity, intratumor genetic heterogeneity and cell signal complexity. As shutdown of a single target does not necessarily eradicate the cancer, the use of combinations of molecular‐targeted agents (MATs) has been proposed, and some pioneering research has been conducted to examine the efficacy of this strategy. In this article, the clinical and preclinical studies that are underway in an attempt to improve the anticancer efficacy of chemotherapies through combination strategies are summarized. Studies of combining cytotoxic agents with MATs, coinhibiting two or more targets in a single pathway or coinhibiting parallel or compensatory pathways as well as specific combinations will be introduced, and the antitumor potentials of each combination strategy will be evaluated.
Effect of lipopolysaccharide on the biological characteristics of human skin fibroblasts and hypertrophic scar tissue formation
Authors: Yang Hongming , Hu Chao , Li Fengyu , Liang Liming , Liu Lingying
Published: May 2013

Burn injury‐mediated destruction of the skin barrier normally induces microbial invasion, in turn leading to the development of systemic infection and occasional septic shock by the release of endotoxins. The objective of this work was to study the influence of lipopolysaccharide (LPS) on the biological characteristics of normal skin fibroblasts and to elucidate the influence of LPS in the initial stage of skin wound healing. Twenty patients with hypertrophic scar in proliferative stage were selected randomly and primary cultures were established from fibroblasts derived from their hypertrophic scar tissue and normal skin. Normal skin fibroblasts of passage 3 were stimulated with different concentrations of LPS. LPS stimulated the proliferation and collagen synthesis of fibroblasts within a certain extent of concentrations (0.005–0.5 μg/mL) (P < 0.05), whereas at a concentration of 1 μg/mL inhibited the proliferation and collagen synthesis of fibroblasts (P < 0.05). Collagen synthesis by normal skin fibroblasts after LPS stimulation mimicked those derived from hypertrophic scar tissue. LPS of 0.1 μg/mL had significant effect on normal skin fibroblasts—continuous passage of these fibroblasts resulted in ultrastructural pattern similar to fibroblasts derived from hypertrophic scar tissue, and the findings was substantiated by hematoxylin and eosin staining and immunohistochemistry detection of proliferation cell nuclear antigen, type I procollagen and α‐smooth muscle actin. Our results suggest that LPS might convert normal skin fibroblasts to hypertrophic scar tissue fibroblasts and participate in the formation of hypertrophic scar; hence, appropriate concentration of LPS may have no effect or be beneficial to skin wound healing, whereas excessive concentration of LPS may delay the time of wound healing. © 2013 IUBMB Life, 65(6):526–532, 2013.
Clinical features of chronic pain with neuropathic characteristics: A symptom‐based assessment using the Pain DETECT Questionnaire
Authors: Shaygan M. , Böger A. , Kröner‐Herwig B.
Published: May 2013

Background

In general, chronic pain is categorized into two mechanism‐based groups: nociceptive and neuropathic pain. This dichotomous approach is questioned and a dimensional perspective is suggested. The present study investigated neuropathic characteristics in different syndromes of chronic pain. We also examined the association of neuropathic characteristics with various pain related and psychological variables.

Methods

From April 2010 to January 2012, 400 patients suffering from a chronic pain condition enrolled for multidisciplinary pain treatment were considered for inclusion in the study. Criteria for inclusion were age over 18 years and having chronic pain according to ICD‐10 (F45.41) criteria. The pain DETECT questionnaire was used to assess neuropathic characteristics of pain.

Results

Thirty‐seven percent of patients with different pain diagnoses demonstrated distinct neuropathic characteristics. The diagnostic groups for neuropathic pain, musculoskeletal pain and post traumatic or surgical pain showed the most neuropathic features. The level of depression, pain chronicity and intensity, disability and length of hospital stay were significantly higher in patients suffering from neuropathic symptoms. A high level of depression and pain chronicity as well as high intensity of pain explained most of the variance in the neuropathic scores. Disability and length of hospital stay significantly predicted neuropathic characteristics only when examined separately, but not if included in a common regression model.

Conclusions

Any type of chronic pain may have more or less neuropathic characteristics. The pain‐related parameters of high intensity and chronicity as well as negative affectivity and functional disability strongly correlate with neuropathic characteristics of pain.
Plasma surface modification of fibroporous polycarbonate urethane membrane by polydimethyl siloxane: Structural characterization, mechanical properties, andin vitrocytocompatibility evaluation
Authors: Arjun G. N. , Menon Girish , Ramesh P.
Published: May 2013

This article reports the surface modification of electrospun polycarbonate urethane membrane with polydimethyl siloxane (PDMS) using plasma‐induced grafting technique for biomedical applications. The nonwoven membranes were characterized for their structure, performance, and compatibility with cells. The surface modification was confirmed by means of attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR) and energy dispersive X‐ray analysis (EDXA). ATR‐FTIR and EDXA analyses displayed characteristic absorption peaks of PDMS for the membrane. The structure and morphology of the developed membranes were studied using scanning electron microscope and microcomputed tomography (µCT). Scanning electron microscopy and µCT revealed the fibrous morphology and percentage porosity of the membranes before and after plasma modification. Static mechanical tests showed that the tensile strength was greater than 8 MPa. Physical characterization of the membranes after immersion in hydrolytic and oxidative media supports their biostability. Cytotoxicity of the membrane was evaluated using L929 fibroblast cells, and the results indicated that the membrane is cytocompatible. Accordingly, these results highlight the potential of this fibrous membrane for biomedical applications. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 947–957, 2014.
In vivo response to an implanted shape memory polyurethane foam in a porcine aneurysm model
Authors: Rodriguez Jennifer N. , Clubb Fred J. , Wilson Thomas S. , Miller Matthew W. , Fossum Theresa W. , Hartman Jonathan , Tuzun Egemen , Singhal Pooja , Maitland Duncan J.
Published: May 2013

Cerebral aneurysms treated by traditional endovascular methods using platinum coils have a tendency to be unstable, either due to chronic inflammation, compaction of coils, or growth of the aneurysm. We propose to use alternate filling methods for the treatment of intracranial aneurysms using polyurethane‐based shape memory polymer (SMP) foams. SMP polyurethane foams were surgically implanted in a porcine aneurysm model to determine biocompatibility, localized thrombogenicity, and their ability to serve as a stable filler material within an aneurysm. The degree of healing was evaluated via gross observation, histopathology, and low vacuum scanning electron microscopy imaging after 0, 30, and 90 days. Clotting was initiated within the SMP foam at time 0 (<1 h exposure to blood before euthanization), partial healing was observed at 30 days, and almost complete healing had occurred at 90 days in vivo, with minimal inflammatory response. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1231–1242, 2014.
Study of a novel three‐dimensional scaffold to repair bone defect in rabbit
Authors: Chen Yushu , Bai Bo , Zhang Shujiang , Ye Jing , Zhai Haohan , Chen Yi , Zhang Linlin , Zeng Yanjun
Published: May 2013

Both decalcified bone matrix (DBM) and fibrin gel possess good biocompatibility, so they are used as scaffolds to culture bone marrow mesenchymal stem cells (BMSCs). The feasibility and efficacy of using compound material being made of decalcified bone matrix and fibrin gel as a three‐dimensional scaffold for bone growth were investigated. BMSCs were isolated from the femur of rabbit, then seeded in prepared scaffolds after incubation for 28 days in vitro. In vivo: 30 New Zealand White Rabbits received bone defect in left radius and divided three treatment groups randomly: (1) BMSCs/decalcified bone matrix/fibrin glue as experimental group; (2) decalcified bone matrix/fibrin glue without cells as control group; (3) nothing was implanted into the bone defects as blank group. The observation period of specimens was 12 weeks, and were analyzed bone formation in terms of serum proteomics (2D‐PAGE and MALDI‐TOF‐TOF‐MS), hematoxylin–eosin (HE) staining, ALP staining, and Osteopontin immunofluorescence detection. The experimental group present in three peculiar kinds of proteins, whose Geninfo identifier (GI) number were 136466, 126722803, and 126723746, respectively, correspond to TTR protein, ALB protein, RBP4 protein, and the histological inspections were superior to the other group. The content of osteopontin in experimental group was significantly higher than control group (p <  0.05). The overall results indicated that a combined material being made of BMSCs/decalcified bone matrix/fibrin glue can result in successful bone formation and decalcified bone matrix/fibrin glue admixtures can be used as a scaffold for bone tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1294–1304, 2014.
Polarization of porous hydroxyapatite scaffolds: Influence on osteoblast cell proliferation and extracellular matrix production
Authors: Cartmell S. H. , Thurstan S. , Gittings J. P. , Griffiths S. , Bowen C. R. , Turner I. G.
Published: May 2013

Improvements to clinically used biomaterials such as hydroxyapatite (HA) are of potential benefit to the patient. One modification, the addition of surface charges, has been shown to have an important role influencing cell response. In this study, porous HA scaffolds with both positive and negative surface charges were manufactured. The samples were sintered in air to produce porous HA ceramic scaffolds in the form of cylinders 12 mm in height × 7 mm in diameter. These were polarized with a dc voltage of 3 kV/cm. MC3T3E1 cells were placed on either negative or positive ends of the charged (or unpoled control) HA scaffolds. At 7 days, picogreen analysis was performed to analyze the cell number at the negative (4 mm), central (4 mm), and positive (4 mm) portions of the 12 mm cylindrical scaffold. At 4 weeks, micro‐CT analysis was performed to quantify the regional volume of mineralized matrix deposition on the 3D scaffold. At 7 days, there were significantly more cells present at the negative end of the scaffold when seeded from the negative end in comparison to the other samples tested. Micro‐CT data at 4 weeks correlated with this finding, demonstrating an increase in mineralized matrix at the negatively charged end of the scaffold seeded from the negative end in comparison to the positively charged and unpoled control scaffolds. The results indicate that the charge on HA influences cell activity and that this phenomenon can be translated to a clinically relevant porous scaffold structure. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1047–1052, 2014.
Dynamics in Poly(ϵ‐Caprolactone) Containing Phase Separated Epoxy Thermosets
Authors: Lützen Hendrik , Hartwig Andreas
Published: May 2013

The dynamic phase separation of poly(ϵ‐caprolactone) (PCL) in cationically polymerized, cycloaliphatic epoxy thermosets is presented. While phase separation processes are commonly unknown from thermosetting polymers due to the covalently crosslinked polymer structure, the gradually occurring formation of crystalline ordered PCL domains is observed. The dynamic process is accompanied by a strong increase in the mechanical moduli and strengthening of the polymer due to the formation of finely distributed domains. Regarding the network and domain structure of the polymer during the dynamic process, the results show rearrangements mainly in the linear PCL segments driven by crystalline interactions without changes in the epoxy matrix polymer.
Resveratrol 3‐O‐d‐glucuronide and resveratrol 4′‐O‐d‐glucuronide inhibit colon cancer cell growth: Evidence for a role of A3 adenosine receptors, cyclin D1 depletion, and G1 cell cycle arrest
Authors: Polycarpou Elena , Meira Lisiane B. , Carrington Simon , Tyrrell Elizabeth , Modjtahedi Helmout , Carew Mark A.
Published: May 2013

Scope

Resveratrol is a plant‐derived polyphenol with chemotherapeutic properties in animal cancer models and many biochemical effects in vitro. Its bioavailability is low and raises the possibility that the metabolites of resveratrol have biological effects. Here we investigate the actions of resveratrol 3‐O‐d‐glucuronide, resveratrol 4′‐O‐d‐glucuronide, and resveratrol 3‐O‐d‐sulfate on the growth of colon cancer cells in vitro.

Methods and results

The growth of Caco‐2, HCT‐116, and CCL‐228 cells was measured using the neutral red and MTT assays. Resveratrol and each metabolite inhibited cell growth with IC50 values of 9.8–31 μM. Resveratrol caused S phase arrest in all three cell lines. Resveratrol 3‐O‐d‐glucuronide and resveratrol 4′‐O‐d‐glucuronide caused G1 arrest in CCL‐228 and Caco‐2 cells. Resveratrol 3‐O‐d‐sulfate had no effect on cell cycle. Growth inhibition was reversed by an inhibitor of AMP‐activated protein kinase (compound C) or an adenosine A3 receptor antagonist (MRS1191). The A3 receptor agonist 2Cl‐IB‐MECA inhibited growth and A3 receptors were detected in all cell lines. The resveratrol glucuronides also reduced cyclin D1 levels but at higher concentrations than in growth experiments and generally did not increase phosphorylated AMP‐activated protein kinase.

Conclusion

Resveratrol glucuronides inhibit cell growth by G1 arrest and cyclin D1 depletion, and our results strongly suggest a role for A3 adenosine receptors in this inhibition.
Protective effects of hydroxytyrosol on liver ischemia/reperfusion injury in mice
Authors: Pan Shangha , Liu Lianxin , Pan Huayang , Ma Yong , Wang Dawei , Kang Kai , Wang Jizhou , Sun Bei , Sun Xueying , Jiang Hongchi
Published: May 2013

Scope

Hydroxytyrosol (HT), a main phenolic compound in olive oil, has been proved to be a potent antioxidant and has beneficial effects on health. However, the effect of HT on oxidative liver damage, as seen in ischemia/reperfusion (I/R) injury, is unknown. Here, we examined whether HT could protect liver against I/R injury.

Methods and results

By using a mouse model, we found that HT administration protects against hepatic I/R injury, as indicated by the decreased levels of serum aminotransferase and less parenchymal necrosis and apoptosis. Serum levels of tumor necrosis factor‐α, interleukin‐6, macrophage inflammatory protein 2, as well as reactive oxygen species (ROS) content in liver tissues, were all decreased by HT, the latter correlated with the reduction of hepatic malondialdehyde (an index of oxidative stress) content and increased activities and expressions of liver antioxidant enzymes superoxide dismutase and catalase. The protective effect was also seen in isolated hepatocytes anoxia/reoxygenation assay.

Conclusion

HT exerts protective effects against hepatic I/R injury in mice, which might be associated with its anti‐oxidative, anti‐inflammatory, and anti‐apoptotic properties. HT may be an effective hepatoprotective agent and a promising candidate for the treatment of liver I/R injury.
Six strategy lessons from Clausewitz and Sun Tzu
Authors: Pars Matthijs
Published: May 2013

A good strategy is crucial for a successful lobby or public affairs campaign. In this article, six strategy lessons from Clausewitz and Sun Tzu's classical works on military strategy are discussed, which could be useful for lobbyists and public affairs managers. Although waging war and lobbying are totally different things, there are also many similarities: both deal with aims to be achieved, opponents, threats and opportunities, (political) victories, and defeats. Therefore, military strategic thinking might provide the field of public affairs with some good and practical insights.

First of all, Sun Tzu and Clausewitz stress the importance of meticulous exploration before the action starts. Subsequently, when laying strategy plans, one should beware of Pyrrhic victories and ‘the fallacies of hope’. Clausewitz, in particular, warns us to expect the unexpected and not to be surprised by the friction between even the best plans and their realization. A good way to handle this friction is to lay down the why and the what of coming actions but not how these actions should be carried out. Both thinkers also provide guidance in how to effectively deal with opponents; surprise an opponent to achieve the upper hand, and bring yourself in a position which will enable a decisive step forward; divide opponents whilst making yourself as strong as possible; and finally prevent a hard‐edged confrontation by offering an alternative. Copyright © 2013 John Wiley & Sons, Ltd.
To what extent can a conjugation between two pairs of peri‐nitro and peri‐amino groups be realized through the naphthalene core?
Authors: Ozeryanskii Valery A. , Filatova Ekaterina A. , Pozharskii Alexander F. , Shevchuk Dmitrii A. , Sorokin Vladimir I.
Published: May 2013

Through‐conjugation for a wide range of 1,8‐diamino‐4,5‐dinitronaphthalenes (N‐acylated, N‐alkylated, N,N′‐bridged, N‐heterocyclic, and N‐deprotonated compounds) was for the first time quantified in solution by means of ultraviolet–visible and proton nuclear magnetic resonance spectroscopy and compared with that of the simpler naphthalene and benzene push‐pull systems. Surprisingly, an extent of conjugation in 1,8‐diamino‐4‐nitro‐ and 1,8‐diamino‐4,5‐dinitronaphthalenes measured in dimethyl sulfoxide is commensurable. On the whole, the repulsive peri‐interactions between the amino groups in systems with N‐alkylated and N‐deprotonated amino groups are more favorable for an effective D‐π‐A charge transfer than in N,N′‐bridged compounds (perimidines, 2,3‐dihydroperimidines and perimidin‐2‐ones). The best electron donors from peri‐positions are pyrrolidin‐1‐yl and methylamido groups. The conclusions obtained from solution studies were deepened by solid‐ state X‐ray experiments for a number of push–pull naphthalenes, including 6,7‐dinitroperimidine N‐anion and two representatives of 4,5‐diaminonaphthalene‐1,8‐dicarbaldehydes. In particular, they helped to trace changes in the bond order redistribution and twisting of the naphthalene core. The latter reaches a record value of 27° for 4,5‐dinitro‐1,8‐di(pyrrolidin‐1‐yl)naphthalene. Copyright © 2013 John Wiley & Sons, Ltd.
Recoverable strain storage capacity of shape memory polyethylene
Authors: Hoeher Robin , Raidt Thomas , Rose Maik , Katzenberg Frank , Tiller Joerg C.
Published: May 2013

Shape memory polymers (SMPs) are an important class of smart materials. So far the focus of such polymers was to find suited triggers for various application fields. Thus, the potential of most of these macromolecular networks regarding their maximally storable strain capability was not explored. In this study, the polyethylenes HDPE, LDPE, and ethylene‐1‐octene (EOC) were systematically investigated with respect to their strain storage potential. To achieve maximum strains, the polymers were chemically cross‐linked in such a way that they are at the borderline between thermoplastics and elastomers. All investigated polymers showed higher strain storage than literature reported systems and exhibited excellent shape memory parameters. The highest stored strain was found for networks of EOC with fully recoverable 1400%. Interestingly, this value could not be enlarged by using EOCs with higher molecular weight, which is probably due to increasing content of entanglements as confirmed by Mooney‐Rivlin. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1033–1040
Investigation of Galaxolide degradation products generated under oxidative and irradiation processes by liquid chromatography/hybrid quadrupole time‐of‐flight mass spectrometry and comprehensive two‐dimensional gas chromatography/time‐of‐flight mass spectrometry
Authors: Herrera López S. , Hernando M. D. , Gómez M. J. , Santiago‐Morales J. , Rosal R. , Fernández‐Alba A. R.
Published: May 2013

RATIONALE

Polycyclic musks have become a concern due to their bioaccumulation potential and ecotoxicological effects. The HHCB transformation product (TP) (1,3,4,6,7,8‐hexahydro‐4,6,6,7,8,8‐hexamethyl‐cyclopenta[γ]‐2‐benzopyran; HHCB‐lactone) is the most stable intermediate generated and it is frequently detected in river waters. The aim of this work was the identification of relevant TPs generated from UV irradiation and ozone treatments.

METHODS

Identification of HHCB TPs was carried out by liquid chromatography/hybrid quadrupole time‐of‐flight mass spectrometry (LC/ESI‐QTOF‐MS) and two‐dimensional gas chromatography/electron impact time‐of‐flight mass spectrometry (GC×GC‐EI‐TOF‐MS). With LC/ESI‐QTOF‐MS, TPs were characterized by means of mass accuracy in both full‐scan and MS/MS modes through information‐dependent acquisition (IDA) and direct injection on‐column. With stir bar sorptive extraction (SBSE)‐GC×GC‐EI‐TOF‐MS, identification was based on the enhanced separation capacity and screening of unknowns through the acquisition of full‐range mass spectra.

RESULTS

The effectiveness of these complementary techniques allowed a detailed evaluation of the main TPs. Eighteen TPs were elucidated based on mass accuracy, in both full‐scan and MS/MS modes using LC/ESI‐QTOF‐MS with mass errors below 5 ppm and 10 ppm (mostly), respectively. Most of the TPs had not been analytically identified in previous studies. Separation of the enantiomeric species (R) and (S) of HHCB‐lactone, and the identification of other relevant TPs, was performed using SBSE‐GC×GC‐EI‐TOF‐MS.

CONCLUSIONS

LC/ESI‐QTOF‐MS and GC×GC‐EI‐TOF‐MS analysis provides the best alternative for TP identification of chemicals of concern, which have a wide range of polarities and isobaric compounds. A prediction of PBT (persistence, bioaccumulation and toxicity) using the PBT Profiler program suggested a classification of 'very persistent' and 'very toxic' for most of the TPs identified. Copyright © 2013 John Wiley & Sons, Ltd.
A dose‐finding approach based on shrunken predictive probability for combinations of two agents in phase I trials
Authors: Hirakawa Akihiro , Hamada Chikuma , Matsui Shigeyuki
Published: May 2013

We develop a novel dose‐finding method for two‐agent combination phase I trials on the basis of the shrunken predictive probability of toxicity. In this method, a shrinkage logistic regression model that allows distinct shrinkage multipliers for the coefficients of the main effects of two agents and their interaction on the probability of toxicity constructs the toxicity outcome. We also propose dose‐escalation/de‐escalation decision rules on the basis of the shrunken predictive probability of toxicity. Simulation studies under various patterns of monotonic dose‐response relationships for combinations of two agents demonstrated that the proposed method performed no worse than the existing two dose‐finding methods we selected. Copyright © 2013 John Wiley & Sons, Ltd.
Function of Ezrin-Radixin-Moesin Proteins in Migration of Subventricular Zone-Derived Neuroblasts Following Traumatic Brain Injury
Authors: Moon Younghye , Kim Joo Yeon , Kim Woon Ryoung , Kim Hyun Jung , Jang Min Jee , Nam Yoonkey , Kim Kyungjin , Kim Hyun , Sun Woong
Published: May 2013

Throughout life, newly generated neuroblasts from the subventricular zone migrate toward the olfactory bulb through the rostral migratory stream. Upon brain injury, these migrating neuroblasts change their route and begin to migrate toward injured regions, which is one of the regenerative responses after brain damage. This injury-induced migration is triggered by stromal cell-derived factor 1 (SDF1) released from microglia near the damaged site; however, it is still unclear how these cells transduce SDF1 signals and change their direction. In this study, we found that SDF1 promotes the phosphorylation of ezrin-radixin-moesin (ERM) proteins, which are key molecules in organizing cell membrane and linking signals from the extracellular environment to the intracellular actin cytoskeleton. Blockade of ERM activation by overexpressing dominant-negative ERM (DN-ERM) efficiently perturbed the migration of neuroblasts. Considering that DN-ERM-expressing neuroblasts failed to maintain proper migratory cell morphology, it appears that ERM-dependent regulation of cell shape is required for the efficient migration of neuroblasts. These results suggest that ERM activation is an important step in the directional migration of neuroblasts in response to SDF1-CXCR4 signaling following brain injury.
Selection on dispersal in isolated butterfly metapopulations
Authors: Bonelli Simona , Vrabec Vladimir , Witek Magdalena , Barbero Francesca , Patricelli Dario , Nowicki Piotr
Published: May 2013

In most metapopulation models dispersal is assumed to be a fixed species‐specific trait, but in reality dispersal abilities are highly sensitive to various selective pressures. Strict isolation of a metapopulation, which precludes any influx of immigrants (and their genes) from outside and makes it impossible for emigrants to reach other localities with suitable habitat, thus reducing fitness benefits of long‐distance dispersal to zero, may be expected to impose strong selection against dispersal. We tested the above prediction by comparing dispersal parameters derived with the Virtual Migration model for isolated and non‐isolated metapopulations of two species of large blueMaculinea(=Phengaris) butterflies, surveyed with intensive mark‐recapture. Mortality during dispersal was found to be twice (inM. teleius) to five times higher (inM. arion) in isolated metapopulations. Isolation also resulted in significantly reduced dispersal distances in isolated metapopulations, with the effect being particularly strong inM. arionfemales. Apart from its evolutionary and ecological consequences, dispersal depression in isolated butterfly metapopulations implied by our results has serious conservation implications. It provides a clear argument against using parameter values obtained in a different environmental setting in modelling applications, e.g., Population Viability Analyses or environmental impact assessment. Furthermore, it underlines the importance of establishing well‐connected networks of suitable habitats prior to species release in areas where reintroductions are planned.
Mucopolysaccharide diseases: A complex interplay between neuroinflammation, microglial activation and adaptive immunity
Authors: Archer Louise D. , Langford‐Smith Kia J. , Bigger Brian W. , Fildes James E.
Published: May 2013

Mucopolysaccharide (MPS) diseases are lysosomal storage disorders (LSDs) caused by deficiencies in enzymes required for glycosaminoglycan (GAG) catabolism. Mucopolysaccharidosis I (MPS I), MPS IIIA, MPS IIIB and MPS VII are deficient in the enzymes α–L‐Iduronidase, Heparan‐N‐Sulphatase, N‐Acetylglucosaminidase and Beta‐Glucuronidase, respectively. Enzyme deficiency leads to the progressive multi‐systemic build‐up of heparan sulphate (HS) and dermatan sulphate (DS) within cellular lysosomes, followed by cell, tissue and organ damage and in particular neurodegeneration. Clinical manifestations of MPS are well established; however as lysosomes represent vital components of immune cells, it follows that lysosomal accumulation of GAGs could affect diverse immune functions and therefore influence disease pathogenesis. Theoretically, MPS neurodegeneration and GAGs could be substantiating a threat of danger and damage to alert the immune system for cellular clearance, which due to the progressive nature of MPS storage would propagate disease pathogenesis. Innate immunity appears to have a key role in MPS; however the extent of adaptive immune involvement remains to be elucidated. The current literature suggests a complex interplay between neuroinflammation, microglial activation and adaptive immunity in MPS disease.
Systematic Review of the Best Evidence in Intramedullary Fixation for Metacarpal Fractures
Authors: Corkum Joseph P. , Davison Peter G. , Lalonde Donald H.
Published: May 2013

Background

Intramedullary (IM) fixation has been described as a reliable method of treatment for certain fracture patterns but has not been widely adopted into practice. The purpose of this study was to evaluate the literature comparing IM fixation to other forms of treatment for metacarpal fractures.

Methods

A systematic review was performed to identify studies investigating the treatment of metacarpal fractures using IM fixation. Inclusion and exclusion criteria were predetermined. Two reviewers independently identified appropriate articles for review based on the criteria. Primary outcome measures were range of motion (ROM) (Styf et al., Rev Chir Orthop Reparatrice Appar Mot 74(Suppl 2):268–270, 2008) and complications. Secondary outcomes included loss of reduction, grip strength, Disabilities of arm, shoulder and hand (DASH) scores, radiographic measures and pain scores.

Results

Eight studies were eligible for review. Studies were of level II–IV evidence, and captured a total of 435 patients. The ROM post-operatively was found to be greater in the IM group in half of the studies. IM fixation trended toward higher complication rates in one study, but no differences were statistically significant. IM fixation fared similarly or superiorly to its competitor in each of the secondary outcomes. A formal meta-regression analysis was not possible given the heterogeneity of studies.

Conclusions

IM fixation may have a role in the treatment of certain metacarpal fractures. No conclusive recommendations can be made based on the available studies included in this literature search. Further study of this technique and its applications using high level evidence is warranted.
The guanylate cyclase signaling system in zebrafish photoreceptors
Authors: Koch Karl-Wilhelm
Published: May 2013

Zebrafish express in the retina a large variety of three different membrane‐bound guanylate cyclases and six different guanylate cyclase‐activating proteins (zGCAPs) belonging to the family of neuronal calcium sensor proteins. Although these proteins are predominantly localized in rod and cone photoreceptor cells of the retina, they differ in their spatial–temporal expression profiles. Further, each zGCAP has a different affinity for Ca2+and displays different Ca2+‐sensitivities of guanylate cyclase activation. Thus, zGCAPs operate as cytoplasmic Ca2+‐sensors that sense incremental changes of cytoplasmic Ca2+‐concentration in rod and cone cells and control the activity of their target guanylate cyclases in a Ca2+‐relay mode fashion.