bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface modifying oligomers used to functionalize polymeric surfaces: Consideration of blood contact applications
Authors: Lopez‐Donaire M. Luisa , Santerre J. Paul 
Published: January 2014

ABSTRACTThe surface modification of existing polymeric biomaterials represents a key strategy for improving the hemocompatibility in long‐ and short‐term biomedical materials without altering their bulk properties. Several techniques have been widely explored to generate surfaces that can prevent the activation of the coagulation system and lead to subsequent clot formation on the surfaces of polymeric blood contacting devices. In particular, strategies whereby the base polymer is blended with surface additives (SMAs) and surface modifying macromolecules (SMMs) are now recognized as practical and effective methods to improve surface polymeric materials. This review highlights the more recent advances in the synthesis of such additives and their blending with base polymers, with a specific focus on SMAs and SMMs with a molecular weight in the oligomeric range (<Mn ∼12 kDa). The surface characterization of these modified materials is discussed in terms of water contact angle, X‐ray photoelectron microscopy, atomic force microscopy, and the blood compatibility behavior, with specific attention to coagulation proteins and platelet adhesion. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40328.
Crystallization and melting properties of poly(butylene succinate) composites with titanium dioxide nanotubes or hydroxyapatite nanorods
Authors: Zhan Jing , Chen Yangjuan , Tang Gang , Pan Haifeng , Zhang Qiangjun , Song Lei , Hu Yuan 
Published: January 2014

ABSTRACTPoly (butylene succinate) (PBS) nanocomposites with titanium dioxide nanotubes (TNTs) or hydroxyapatite nanorods (HAP) were prepared, and the effect of the nano‐inorganics on the nonisothermal crystallization and melting properties of PBS were studied in detail by differential scanning calorimeter. The nonisothermal crystallization kinetics of PBS and its nanocomposites were analyzed by the Avrami, Ozawa, and Mo methods. It is found that the presence of TNTs increases the crystallization temperature and rate of PBS composites, but decreases the crystallization activation energy and crystallinity. By comparison, the crystallization rate of the PBS composite is decreased with the addition of HAP. The melting, recrystallization, and remelting mechanism results in the formation of two melting endothermic peaks during the melting process of neat PBS and its nanocomposites. The model proposed by Mo could successfully describe the nonisothermal crystallization process of PBS and its nanocomposites. At a given crystallinity, the F(t) values decrease in the order of PBS/HAP, PBS, and PBS/TNTs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40335.
Identification of Staphylococcus aureus α‐hemolysin as a protein drug that is secreted by anticancer bacteria and rapidly kills cancer cells
Authors: Swofford Charles A. , St. Jean Adam T. , Panteli Jan T. , Brentzel Zachary J. , Forbes Neil S. 
Published: January 2014

ABSTRACTTargeted bacterial delivery of anticancer proteins has the ability to overcome therapeutic resistance in tumors that limits the efficacy of chemotherapeutics. The ability of bacteria to specifically target tumors allows for delivery of aggressive proteins that directly kill cancer cells and cannot be administered systemically. However, few proteins have been tested for this purpose. To identify effective molecules, we systematically sorted proteins that have been shown to cause mammalian cell death. The genes for five proteins were selected and cloned into Escherichia coli and Salmonella. Supernatant from cultures of the transformed bacteria was applied to flasks of MCF‐7 mammary carcinoma cells to identify proteins that (1) were expressed, (2) secreted, and (3) rapidly killed cancer cells. Time‐lapse images were taken to visualize mammalian cell morphology. Of the investigated proteins, α‐hemolysin from Staphylococcus aureus (SAH) was the most promising because it was secreted, caused trauma to cellular membranes, and induced oncosis in 18 min. After exposure for 6 h, SAH decreased cell viability by 90%. In comparison, the positive control, Pseudomonas aeruginosa exotoxin A (PEA), required 11 days to achieve a similar effect, when administered at 3,000 times its LC50. The maximum death rate induced by SAH was calculated to be a reduction in cell viability of 7.1% per min, which was 200‐fold faster than the PEA control. Two proteins, Dermonecrotic Toxin and Phospholipase C were active when extracted from the bacterial cytoplasm but were not secreted. This investigation revealed for the first time SAH as a potent anticancer drug for delivery by bacteria because of its ability to be secreted in a fully functional form and aggressively kill cancer cells. Biotechnol. Bioeng. 2014;111: 1233–1245. © 2014 Wiley Periodicals, Inc.
A variant upstream of HLA‐DRB1 and multiple variants in MICA influence susceptibility to cervical cancer in a Swedish population
Authors: Chen Dan , Hammer Joanna , Lindquist David , Idahl Annika , Gyllensten Ulf 
Published: January 2014

AbstractIn a genome‐wide association study, we have previously identified and performed the initial replication of three novel susceptibility loci for cervical cancer: rs9272143 upstream of HLA‐DRB1, rs2516448 adjacent to MHC class I polypeptide‐related sequence A gene (MICA), and rs3117027 at HLA‐DPB2. The risk allele T of rs2516448 is in perfect linkage disequilibrium with a frameshift mutation (A5.1) in MICA exon 5, which results in a truncated protein. To validate these associations in an independent study and extend our prior work to MICA exon 5, we genotyped the single‐nucleotide polymorphisms at rs9272143, rs2516448, rs3117027 and the MICA exon 5 microsatellite in a nested case–control study of 961 cervical cancer patients (827 carcinoma in situ and 134 invasive carcinoma) and 1725 controls from northern Sweden. The C allele of rs9272143 conferred protection against cervical cancer (odds ratio [OR] = 0.73, 95% confidence interval [CI] = 0.65–0.82; P = 1.6 × 10−7), which is associated with higher expression level of HLA‐DRB1, whereas the T allele of rs2516448 increased the susceptibility to cervical cancer (OR = 1.33, 95% CI = 1.19–1.49; P = 5.8 × 10−7), with the same association shown with MICA‐A5.1. The direction and the magnitude of these associations were consistent with our previous findings. We also identified protective effects of the MICA‐A4 (OR = 0.80, 95% CI = 0.68–0.94; P = 6.7 × 10−3) and MICA‐A5 (OR = 0.60, 95% CI = 0.50–0.72; P = 3.0 × 10−8) alleles. The associations with these variants are unlikely to be driven by the nearby human leukocyte antigen (HLA) alleles. No association was observed between rs3117027 and risk of cervical cancer. Our results support the role of HLA‐DRB1 and MICA in the pathogenesis of cervical cancer.
Access, excess, and overdiagnosis: the case for thyroid cancer
Authors: Hall Stephen F. , Irish Jonathan , Groome Patti , Griffiths Rebecca 
Published: January 2014

AbstractThe incidence of thyroid cancer in women is increasing at an epidemic rate. Numerous studies have proposed that the cause is increasing detection due to availability and use of medical diagnostic ultrasound. Our objective was to compare rates of diagnosis across different health‐care regions to rates of diagnostic tests and to features of both health and access of the regional populations. This is a population‐based retrospective ecological observational study of 12,959 patients with thyroid cancer between January 1, 2000 and December 31, 2008 in Ontario Canada based on the health‐care utilization regions (Local Health Integration Networks) of the province of Ontario Canada. We found that some regions of Ontario had four times the rates of diagnosis of thyroid cancer compared to other regions. The regions with the highest use of discretionary medical tests (pelvic ultrasound, abdominal ultrasound, neck ultrasound, echocardiogram, resting electrocardiogram, cardiac nuclear perfusion tests, and bone scan), highest population density, and better education had the highest rates of thyroid cancer diagnoses. Differences in the rates of the ordering of discretionary diagnostic medical tests, such as diagnostic ultrasound, in different geographic regions of Ontario lead to differences in the rates of diagnosis of thyroid cancer.
Hybrid Photopatterned Enzymatic Reaction (HyPER) for in Situ Cell Manipulation
Authors: Griffin Donald R. , Borrajo Jacob , Soon Allyson , Acosta‐Vélez Giovanny F. , Oshita Victor , Darling Nicole , Mack Julia , Barker Thomas , Iruela‐Arispe M. Luisa , Segura Tatiana 
Published: January 2014

AbstractThe ability to design artificial extracellular matrices as cell‐instructive scaffolds has opened the door to technologies capable of studying the fate of cells in vitro and to guiding tissue repair in vivo. One main component of the design of artificial extracellular matrices is the incorporation of biochemical cues to guide cell phenotype and multicellular organization. The extracellular matrix (ECM) is composed of a heterogeneous mixture of proteins that present a variety of spatially discrete signals to residing cell populations. In contrast, most engineered ECMs do not mimic this heterogeneity. In recent years, photo‐deprotection has been used to spatially immobilize signals. However, this approach has been limited mostly to small peptides. Here we combine photo‐deprotection with enzymatic reaction to achieve spatially controlled immobilization of active bioactive signals that range from small molecules to large proteins. A peptide substrate for transglutaminase factor XIII (FXIIIa) was caged with a photo‐deprotectable group, which was then immobilized to the bulk of a cell‐compatible hydrogel. With focused light, the substrate can be deprotected and used to immobilize patterned bioactive signals. This approach offers an innovative strategy to immobilize delicate bioactive signals, such as growth factors, without loss of activity and enables in situ cell manipulation of encapsulated cells.
Hedycaryol Synthase in Complex with Nerolidol Reveals Terpene Cyclase Mechanism
Authors: Baer Philipp , Rabe Patrick , Citron Christian A. , de Oliveira Mann Carina C. , Kaufmann Norman , Groll Michael , Dickschat Jeroen S. 
Published: January 2014

AbstractThe biosynthesis of terpenes is catalysed by class I and II terpene cyclases. Here we present structural data from a class I hedycaryol synthase in complex with nerolidol, serving as a surrogate for the reaction intermediate nerolidyl diphosphate. This prefolded ligand allows mapping of the active site and hence the identification of a key carbonyl oxygen of Val179, a highly conserved helix break (G1/2) and its corresponding helix dipole. Stabilising the carbocation at the substrate's C1 position, these elements act in concert to catalyse the 1,10 ring closure, thereby exclusively generating the anti‐Markovnikov product. The delineation of a general mechanistic scaffold was confirmed by site‐specific mutations. This work serves as a basis for understanding carbocation chemistry in enzymatic reactions and should contribute to future application of these enzymes in organic synthesis.
Acoustic Alignment of a Supramolecular Nanofiber in Harmony with the Sound of Music
Authors: Miura Ryosuke , Ando Yasunari , Hotta Yasuhisa , Nagatani Yoshiki , Tsuda Akihiko 
Published: January 2014

AbstractAudible sound with a low‐frequency vibration brings about hydrodynamic alignment of a supramolecular nanofiber in solution. Design of the nanoscale molecules and molecular assemblies, which can sense a wide range of frequencies of the audible sound wave with high sensitivity, develops sound‐driven molecular machines and sound‐responsive nanomaterials, and is also interesting for investigation of unknown physical interactions between the molecules and audible sound vibrations. In this study, it was found that a supramolecular nanofiber, composed of an anthracene derivative AN, in an n‐hexane solution aligned upon exposure to an audible sound wave at frequencies up to 1000 Hz, with quick responses to the sound and silence, and to amplitude and frequency changes of the sound wave. These properties are of great advantage to sense dynamic changes of fluid flows, such as those induced by the sound of music. Music is composed of multiple complex sounds and silence, which characteristically change in the course of its playing time. When classical music was playing, the AN nanofiber aligned itself in harmony with the sound of the music. Time course linear dichroism spectroscopy revealed the dynamic acoustic alignments of the AN nanofiber in the solution upon playing the music. The sound vibrations of music, which generate acoustic streaming flows in liquid media, allowed shear‐induced alignments of the nanofiber.
Toxicity of Ionic Liquids: Eco(cyto)activity as Complicated, but Unavoidable Parameter for Task‐Specific Optimization
Authors: Egorova Ksenia S. , Ananikov Valentine P. 
Published: January 2014

AbstractRapid progress in the field of ionic liquids in recent decades led to the development of many outstanding energy‐conversion processes, catalytic systems, synthetic procedures, and important practical applications. Task‐specific optimization emerged as a sharpening stone for the fine‐tuning of structure of ionic liquids, which resulted in unprecedented efficiency at the molecular level. Ionic‐liquid systems showed promising opportunities in the development of green and sustainable technologies; however, the chemical nature of ionic liquids is not intrinsically green. Many ionic liquids were found to be toxic or even highly toxic towards cells and living organisms. In this Review, we show that biological activity and cytotoxicity of ionic liquids dramatically depend on the nature of a biological system. An ionic liquid may be not toxic for particular cells or organisms, but may demonstrate high toxicity towards another target present in the environment. Thus, a careful selection of biological activity data is a must for the correct assessment of chemical technologies involving ionic liquids. In addition to the direct biological activity (immediate response), several indirect effects and aftereffects are of primary importance. The following principal factors were revealed to modulate toxicity of ionic liquids: i) length of an alkyl chain in the cation; ii) degree of functionalization in the side chain of the cation; iii) anion nature; iv) cation nature; and v) mutual influence of anion and cation.
Enhanced Performance of Supported HfO2 Counter Electrodes for Redox Couples Used in Dye‐Sensitized Solar Cells
Authors: Yun Sining , Pu Haihui , Chen Junhong , Hagfeldt Anders , Ma Tingli 
Published: January 2014

AbstractMesoporous‐graphitic‐carbon‐supported HfO2 (HfO2‐MGC) nanohybrids were synthesized by using a soft‐template route. Characterization and a systematic investigation of the catalytic properties, stability, and catalytic mechanism were performed for HfO2‐MGC counter electrodes (CEs) in dye‐sensitized solar cells (DSSCs). The new HfO2‐MGC as a CE in DSSCs showed a surprisingly high efficiency of 7.75 % for the triiodide/iodide redox couple and 3.69 % for the disulfide/thiolate redox couple, greater than the Pt electrode in the corresponding electrolyte system, which opens up a possibility for its practical application.
Content‐based image retrieval over IEEE 802.11b noisy wireless networks
Authors: Chatzistavros Evaggelos , Chatzichristofis Savvas A. , Zagoris Konstatinos , Stamatelos George 
Published: January 2014

SummaryMobile devices such as smartphones and tablets are widely used in everyday life to perform a variety of operations, such as e‐mail exchange, connection to social media, bank/financial transactions, and so on. Moreover, because of the large growth of multimedia applications, video and image transferring and sharing via a wireless network is becoming increasingly popular. Several modern mobile applications perform information retrieval and image recognition. For example, Google Goggles is an image recognition application that is used for searches based on pictures taken by handheld devices. In most of the cases, image recognition procedure is an image retrieval procedure. The captured images or a low‐level description of them are uploaded online, and the system recognizes their content by retrieving visually similar pictures. Taking into account the last comment, our goal in this paper is to evaluate the process of image retrieval/recognition over an Institute of Electrical and Electronics Engineers 802.11b network, operating at 2.4 GHz. Our evaluation is performed through a simulated network configuration, which consists of a number of mobile nodes communicating with an access point. Throughout our simulations, we examine the impact of several factors, such as the existence of a strong line of sight during the communication between wireless devices. Strong line of sight depends on the fading model used for the simulations and has an effect on BER. We have used a large number of image descriptors and a variety of scenarios, reported in the relative literature, in order to comprehensively evaluate our system. To reinforce our results, experiments were conducted on two well‐known images databases by using 10 descriptors from the literature. Copyright © 2014 John Wiley & Sons, Ltd.
Amplify‐and‐forward‐based cooperative jamming strategy with power allocation for secure communication
Authors: Li An , Xu Yizhu , Wang Yuhao , Sun Lihua 
Published: January 2014

SummaryThis paper deals with the use of jamming transmission for secure amplify‐and‐forward‐based relay networks with total power constraints. An approach that the source and the relay use some of their available power to transmit jamming signals in order to create interference at the eavesdropper is investigated. Assume that the relay and destination have an a priori knowledge of the jamming signals. A power allocation policy that defines how the available power is distributed between the message signal and that of the jamming signal is presented. The results show that the proposed approach can increase the secrecy level and that a positive secrecy rate can be achieved even when the eavesdropper may be near the source. Copyright © 2014 John Wiley & Sons, Ltd.
Emotion acceptance behavior therapy for anorexia nervosa: A pilot study
Authors: Wildes Jennifer E. , Marcus Marsha D. , Cheng Yu , McCabe Elizabeth B. , Gaskill Jill A. 
Published: January 2014

ABSTRACTObjectiveThis study aimed to evaluate the preliminary effectiveness of Emotion Acceptance Behavior Therapy (EABT), an outpatient psychotherapeutic intervention for anorexia nervosa (AN) based on a disorder‐specific model of symptom maintenance that emphasizes emotion avoidance. EABT combines standard behavioral interventions that are central to the clinical management of AN with evidence‐supported strategies to increase emotion awareness, decrease emotion avoidance, and encourage resumption of valued activities and relationships outside the eating disorder.MethodTwenty‐four individuals aged ≥17 years with AN were treated using the EABT manual. EABT was delivered in 33–58 individual sessions provided over 38–53 weeks. Assessments were conducted before and after treatment, and at 3‐ and 6‐month follow‐ups.ResultsThirteen patients (54.2%) completed EABT; 11 (45.8%) dropped out or were withdrawn. EABT was associated with significant improvements in weight, disordered eating symptoms, and emotion avoidance that were maintained over 6‐month follow‐up. The majority of EABT completers achieved a body mass index >18.5 (n = 9/13) or had a normal Eating Disorder Examination Global score (n = 10/13) at post‐treatment.DiscussionPreliminary data suggest that EABT may have utility for a subset of adults with AN. Future research will focus on improving outcomes in EABT nonresponders and identifying of mechanisms that drive treatment response. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:870–873)
Phylogeography of Liquidambar styraciflua (Altingiaceae) in Mesoamerica: survivors of a Neogene widespread temperate forest (or cloud forest) in North America?
Authors: Ruiz‐Sanchez Eduardo , Ornelas Juan Francisco 
Published: January 2014

AbstractWe investigate the genetic variation between populations of the American sweetgum (Liquidambar styraciflua), a tree species with a disjunct distribution between northeastern Texas and Mexico, by analyzing sequences of two chloroplast DNA plastid regions in Mesoamerica. Our results revealed phylogeographical structure, with private haplotypes distributed in unique environmental space at either side of the Trans‐Mexican Volcanic Belt, and a split in the absence of gene flow dating back ca. 4.2–1.4 million years ago (MYA). Species distribution modeling results fit a model of refugia along the Gulf and Atlantic coasts but the present ranges of US and Mesoamerican populations persisted disjunct during glacial/interglacial cycles. Divergence between the US and Mesoamerican (ca. 8.4–2.8 MYA) populations of L. styraciflua and asymmetrical gene flow patterns support the hypothesis of a long‐distance dispersal during the Pliocene, with fragmentation since the most recent glacial advance (120,000 years BP) according to coalescent simulations and high effective migration rates from Mesoamerica to the USA and close to zero in the opposite direction. Our findings implicate the Trans‐Mexican Volcanic Belt as a porous barrier driving genetic divergence of L. styraciflua, corresponding with environmental niche differences, during the Pliocene to Quaternary volcanic arc episode 3.6 MYA, and a Mesoamerican origin of populations in the USA.
Development of a family of unconditionally stable explicit direct integration algorithms with controllable numerical energy dissipation
Authors: Kolay Chinmoy , Ricles James M. 
Published: January 2014

SUMMARYThe implicit dissipative generalized‐ α method is analyzed using discrete control theory. Based on this analysis, a one‐parameter family of explicit direct integration algorithms with controllable numerical energy dissipation, referred to as the explicit KR‐α method, is developed for linear and nonlinear structural dynamic numerical analysis applications. Stability, numerical dispersion, and energy dissipation characteristics of the proposed algorithms are studied. It is shown that the algorithms are unconditionally stable for linear elastic and stiffness softening‐type nonlinear systems, where the latter indicates a reduction in post yield stiffness in the force–deformation response. The amount of numerical damping is controlled by a single parameter, which provides a measure of the numerical energy dissipation at higher frequencies. Thus, for a specific value of this parameter, the resulting algorithm is shown to produce no numerical energy dissipation. Furthermore, it is shown that the influence of the numerical damping on the lower mode response is negligible. It is further shown that the numerical dispersion and energy dissipation characteristics of the proposed explicit algorithms are the same as that of the implicit generalized‐ α method. A numerical example is presented to demonstrate the potential of the proposed algorithms in reducing participation of undesired higher modes by using numerical energy dissipation to damp out these modes. Copyright © 2014 John Wiley & Sons, Ltd.