bluuebunny/crossref_metadata_2025_split huggingface dataset:
Injectable in situ forming glucose‐responsive dextran‐based hydrogels to deliver adipogenic factor for adipose tissue engineering
Authors: Tan Huaping , Hu Xiaohong 
Published: April 2012

AbstractAn injectable and glucose‐responsive hydrogel derived from dextran derivatives and lectin concanavalin A (ConA) was synthesized to deliver adipogenic factor for adipose tissue engineering. The gelation is attributed to the Schiff‐base reaction cross‐linking between aldehydic and aminated dextran. To enhance adipogenesis, the adipogenic factor of insulin was incorporated in the ConA immobilized hydrogels. The gelation time, compressive modulus, morphologies, weight loss, and swelling properties of the hydrogels were investigated. The ConA triggered a competitive displacement of dextran by glucose from the lectin receptor sites, and results in increasing swelling of the gel network. The swelling ratio (SR) of ConA immobilized hydrogel showed glucose dependent properties and linearly increased from 19.8 to 31.3 at 37°C in PBS at glucose concentrations between 0 and 1.0% (w/v). The in vitro release experiments showed that the insulin would be released from this dextran hydrogel into the local microenvironment in response to glucose, thus highlighting the potential of such a injectable and biodegradable hydrogel to be used as part of implantable scaffold to delivery adipogenic factor for adipose tissue engineering. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and characterization of photocured thiol‐ene hydrogel: Adsorption of Au(III) ions from aqueous solutions
Authors: Fırlak Melike , Kahraman Memet Vezir , Yetimoğlu Ece Kök 
Published: April 2012

AbstractIn this study, photocured a novel thiol‐ene hydrogels based on P(Penta3MP4/PEG‐DA/HEMA) were investigated for adsorption of Au(III) ions from aqueous solutions purposes. The photopolymerization kinetics of thiol‐ene‐based formulations was investigated by real‐time infrared spectroscopy. The chemical composition and surface morphology of hydrogels were also characterized. The effect of different parameters on Au(III) adsorption efficiency was examined in detail. Better adsorption behavior was achieved for Au(III) by P(Penta3MP4/PEG‐DA/HEMA) F1 hydrogels. The maximum uptake for Au(III) was at pH 0.5. Both Langmuir and Freundlich adsorption isotherm models were applied and the reusability of thiol‐ene hydrogels investigated. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Probing of C‐terminal lysine variation in a recombinant monoclonal antibody production using Chinese hamster ovary cells with chemically defined media
Authors: Luo Jun , Zhang Jian , Ren Diya , Tsai Wen‐Lin , Li Feng , Amanullah Ashraf , Hudson Terry 
Published: April 2012

AbstractC‐terminal lysine (C‐K) variants are commonly observed in therapeutic monoclonal antibodies and recombinant proteins. Heterogeneity of C‐K residues is believed to result from varying degree of proteolysis by endogenous carboxypeptidase(s) during cell culture production. The achievement of batch‐to‐batch culture performance and product quality reproducibility is a key cell culture development criterion. Understanding the operational parameters affecting C‐K levels provides valuable insight into the cell culture process. A CHO cell line X expressing a recombinant antibody was selected as the model cell line due to the exhibited sensitivity of its C‐K level to the process conditions. A weak cation exchange chromatography (WCX) method with or without carboxypeptidase B (CpB) treatment was developed to monitor the C‐K level for in‐process samples. The effects of operating conditions (i.e., temperature and culture duration) and media trace elements (copper and zinc) on C‐K variants were studied. The dominant effect on C‐K level was identified as the trace elements concentration. Specifically, increased C‐K levels were observed with increase of copper concentration and decrease of zinc concentration in chemically defined medium. Further, a hypothesis for C‐K processing with intracellular and extracellular carboxypeptidase activity was proposed, based on preliminary intracellular carboxypeptidase Western blot results and the extracellular HCCF holding study. Biotechnol. Bioeng. 2012;109: 2306–2315. © 2012 Wiley Periodicals, Inc.
Dynamics of diffusivity and pressure drop in flow‐through and parallel‐flow bioreactors during tissue regeneration
Authors: Podichetty Jagdeep T. , Dhane Dhananjay V. , Madihally Sundararajan V. 
Published: April 2012

AbstractIn this study, transport characteristics in flow‐through and parallel‐flow bioreactors used in tissue engineering were simulated using computational fluid dynamics. To study nutrient distribution and consumption by smooth muscle cells colonizing the 100 mm diameter and 2‐mm thick scaffold, effective diffusivity of glucose was experimentally determined using a two‐chambered setup. Three different concentrations of chitosan–gelatin scaffolds were prepared by freezing at −80°C followed by lyophilization. Experiments were performed in both bioreactors to measure pressure drop at different flow rates. At low flow rates, experimental results were in agreement with the simulation results for both bioreactors. However, increase in flow rate beyond 5 mL/min in flow‐through bioreactor showed channeling at the circumference resulting in lower pressure drop relative to simulation results. The Peclet number inside the scaffold indicated nutrient distribution within the flow‐through bioreactor to be convection‐dependent, whereas the parallel‐flow bioreactor was diffusion‐dependent. Three alternative design modifications to the parallel‐flow were made by (i) introducing an additional inlet and an outlet, (ii) changing channel position, and (iii) changing the hold‐up volume. Simulation studies were performed to assess the effect of scaffold thickness, cell densities, and permeability. These new designs improved nutrient distribution for 2 mm scaffolds; however, parallel‐flow configuration was found to be unsuitable for scaffolds more than 4‐mm thick, especially at low porosities as tissues regenerate. Furthermore, operable flow rate in flow‐through bioreactors is constrained by the mechanical strength of the scaffold. In summary, this study showed limitations and differences between flow‐through and parallel‐flow bioreactors used in tissue engineering. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 1045–1054, 2012
Tropomodulins: Pointed‐end capping proteins that regulate actin filament architecture in diverse cell types
Authors: Yamashiro Sawako , Gokhin David S. , Kimura Sumiko , Nowak Roberta B. , Fowler Velia M. 
Published: April 2012

AbstractTropomodulins are a family of four proteins (Tmods 1–4) that cap the pointed ends of actin filaments in actin cytoskeletal structures in a developmentally regulated and tissue‐specific manner. Unique among capping proteins, Tmods also bind tropomyosins (TMs), which greatly enhance the actin filament pointed‐end capping activity of Tmods. Tmods are defined by a TM‐regulated/Pointed‐End Actin Capping (TM‐Cap) domain in their unstructured N‐terminal portion, followed by a compact, folded Leucine‐Rich Repeat/Pointed‐End Actin Capping (LRR‐Cap) domain. By inhibiting actin monomer association and dissociation from pointed ends, Tmods regulate actin dynamics and turnover, stabilizing actin filament lengths and cytoskeletal architecture. In this review, we summarize the genes, structural features, molecular and biochemical properties, actin regulatory mechanisms, expression patterns, and cell and tissue functions of Tmods. By understanding Tmods' functions in the context of their molecular structure, actin regulation, binding partners, and related variants (leiomodins 1–3), we can draw broad conclusions that can explain the diverse morphological and functional phenotypes that arise from Tmod perturbation experiments in vitro and in vivo. Tmod‐based stabilization and organization of intracellular actin filament networks provide key insights into how the emergent properties of the actin cytoskeleton drive tissue morphogenesis and physiology. © 2012 Wiley Periodicals, Inc
Identification of Selective Inhibitors of the Potassium Channel Kv1.1–1.2(3) by High‐Throughput Virtual Screening and Automated Patch Clamp
Authors: Wacker Sören J. , Jurkowski Wiktor , Simmons Katie J. , Fishwick Colin W. G. , Johnson A. Peter , Madge David , Lindahl Erik , Rolland Jean‐Francois , de Groot Bert L. 
Published: April 2012

AbstractTwo voltage‐dependent potassium channels, Kv1.1 (KCNA1) and Kv1.2 (KCNA2), are found to co‐localize at the juxtaparanodal region of axons throughout the nervous system and are known to co‐assemble in heteromultimeric channels, most likely in the form of the concatemer Kv1.1–1.2(3). Loss of the myelin sheath, as is observed in multiple sclerosis, uncovers the juxtaparanodal region of nodes of Ranvier in myelinated axons leading to potassium conductance, resulting in loss of nerve conduction. The selective blocking of these Kv channels is therefore a promising approach to restore nerve conduction and function. In the present study, we searched for novel inhibitors of Kv1.1–1.2(3) by combining a virtual screening protocol and electrophysiological measurements on a concatemer Kv1.1–1.2(3) stably expressed in Chinese hamster ovary K1 (CHO‐K1) cells. The combined use of four popular virtual screening approaches (eHiTS, FlexX, Glide, and Autodock‐Vina) led to the identification of several compounds as potential inhibitors of the Kv1.1–1.2(3) channel. From 89 electrophysiologically evaluated compounds, 14 novel compounds were found to inhibit the current carried by Kv1.1–1.2(3) channels by more than 80 % at 10 μM. Accordingly, the IC50 values calculated from concentration–response curve titrations ranged from 0.6 to 6 μM. Two of these compounds exhibited at least 30‐fold higher potency in inhibition of Kv1.1–1.2(3) than they showed in inhibition of a set of cardiac ion channels (hERG, Nav1.5, and Cav1.2), resulting in a profile of selectivity and cardiac safety. The results presented herein provide a promising basis for the development of novel selective ion channel inhibitors, with a dramatically lower demand in terms of experimental time, effort, and cost than a sole high‐throughput screening approach of large compound libraries.
Vector diffusion maps and the connection Laplacian
Authors: Singer A. , Wu H.‐T. 
Published: April 2012

AbstractWe introduce vector diffusion maps (VDM), a new mathematical framework for organizing and analyzing massive high‐dimensional data sets, images, and shapes. VDMis a mathematical and algorithmic generalization of diffusion maps and other nonlinear dimensionality reduction methods, such as LLE, ISOMAP, and Laplacian eigenmaps. While existing methods are either directly or indirectly related to the heat kernel for functions over the data, VDM is based on the heat kernel for vector fields. VDM provides tools for organizing complex data sets, embedding them in a low‐dimensional space, and interpolating and regressing vector fields over the data. In particular, it equips the data with a metric, which we refer to as the vector diffusion distance. In the manifold learning setup, where the data set is distributed on a low‐dimensional manifold
${\cal M}^d$
embedded in $\font\open=msbm10 at 10pt\def\R{\hbox{\open R}}\R^p$, we prove the relation between VDM and the connection Laplacian operator for vector fields over the manifold. © 2012 Wiley Periodicals, Inc.
RNA/DNA ratios in American glass eels (Anguilla rostrata): evidence for latitudinal variation in physiological status and constraints to oceanic migration?
Authors: Laflamme Simon , Côté Caroline , Gagnaire Pierre‐Alexandre , Castonguay Martin , Bernatchez Louis 
Published: April 2012

AbstractDuring their larval leptocephalus phase, newly hatched American eels undergo an extensive oceanic migration from the Sargasso Sea toward coastal and freshwater habitats. Their subsequent metamorphosis into glass eel is accompanied by drastic morphological and physiological changes preceding settlement over a wide geographic range. The main objective of this study was to compare RNA/DNA ratios and condition factor among glass eels in order to test the null hypothesis of no difference in physiological status and metabolic activity of glass eels at the outcome of their oceanic migration. This was achieved by analyzing glass eel samples collected at the mouth of 17 tributaries covering a latitudinal gradient across the species distribution range from Florida to Gaspésie (Québec). Our main observations were (i) a latitudinal increase in mean total length; (ii) a latitudinal variation in mean RNA/DNA ratios, which was best explained by a quadratic model reaching its minimum in the central range of sampling locations; and (iii) a latitudinal variation in Fulton's condition factor, which was best explained by a quadratic model reaching its maximum in the central range of sampling locations. Below we discuss the possible links between latitudinal variation in glass eel physiological status and variable energetic and environmental constraints to oceanic migration as a function of latitudinal distribution.
Novel Sensors for Batch and Flow Injection Analysis of Histamine Based on Crown Ethers
Authors: Elmosallamy Mohamed A. F. 
Published: April 2012

AbstractSix types of histamine potentiometric sensors are developed. They are based on using dibenzo‐30‐crown‐10 (DB30C10) with potassium tetrakis(p‐chlorophenyl)borate lipophilic additive (Type I), dibenzo‐30‐crown‐10 without additive (Type II), dibenzo‐24‐crown‐8 (DB24C8) with the same additive (Type III), dibenzo‐24‐crown‐8 without additive (Type IV), dibenzo‐18‐crown‐6 with the additive (Type V) and dibenzo‐18‐crown‐6 without additive (Type VI) as neutral carriers for histamine. Sensors based on dibenzo‐30‐crown‐10 with (PTp‐C1PB) lipophilic additive (Type I) and dibenzo‐30‐crown‐10 without additive (Type II) show good response. The other sensors Types III–VI show poor response in terms of calibration range and slope.
Methoxylation and Glycosylation Effect on the Redox Mechanism of Citroflavones
Authors: Diculescu Victor Constantin , Satana H. Eda , de Souza Gil Eric , Brett Ana Maria Oliveira 
Published: April 2012

AbstractThe methoxylation and glycosylation effect on the redox mechanism of citroflavones, isorhoifolin, linarin, diosmetin and diosmin, was investigated. All citroflavones’ hydroxyl groups can be electrochemically oxidised, and the oxidation at the B‐ring occurs at a lower potential than at the A‐ring. The electrochemical oxidation is irreversible, pH‐dependent, with occurrence of one or two oxidation products, which undergo reversible redox reactions, depending on the number of OH substituents on the molecule. The glycosylation leads to a steric effect and decreasing of the oxidation peak currents whereas the methylation involves the formation of nonelectroactive oxidation products.
Plant root traits affecting the resistance of soils to concentrated flow erosion
Authors: Burylo Melanie , Rey Freddy , Mathys Nicolle , Dutoit Thierry 
Published: April 2012

ABSTRACTThe effect of plant species on erosion processes may be decisive for long‐term soil protection in degraded ecosystems. The identification of functional effect traits that predict species ability for erosion control would be of great interest for ecological restoration purposes. Flume experiments were carried out to investigate the effect of the root systems of three species having contrasted ecological requirements from eroded marly lands of the French Southern Alps [i.e. Robinia pseudo acacia (tree), Pinus nigra austriaca (tree) and Achnatherum calamagrostis (grass)], on concentrated flow erosion rates. Ten functional traits, describing plant morphological and biomechanical features, were measured on each tested sample. Analyses were performed to identify traits that determine plant root effects on erosion control. Erosion rates were lowest for samples of Robinia pseudo acacia, intermediate in Achnatherum calamagrostis and highest in Pinus nigra austriaca. The three species also differed strongly in their traits. Principal components analysis showed that the erosion‐reducing potential of plant species was negatively correlated to root diameter and positively correlated to the percentage of fine roots. The results highlighted the role of small flexible roots in root reinforcement processes, and suggested the importance of high root surface and higher tensile strength for soil stabilization. By combining flume experiment to plant functional traits measurements, we identified root system features influencing plant species performance for soil protection against concentrated flow erosion. Plant functional traits related to species efficiency for erosion control represent useful tools to improve the diagnosis of land vulnerability to erosion, plant community resistance and the prediction of ecosystem functioning after ecological restoration. Copyright © 2012 John Wiley & Sons, Ltd.
The anastomosing pattern and the extensively distributed scroll bars in the middle Amazon River
Authors: Rozo Max G. , Nogueira Afonso C. R. , Truckenbrodt Werner 
Published: April 2012

ABSTRACTThe middle Amazon River, between the confluences of the Negro and Madeira Rivers in Brazil, shows an anastomosing morphology with relatively stable, multiple interconnected channels that locally enclose floodbasins. Additionally, this system is characterized by sinuous secondary channels with meander development, discontinuous natural levees concentrated on the concave banks and extensively distributed scroll bars mainly in the islands, related to subrecent and present‐day migration of mainly secondary channels. This distinguishes the Amazon from many other anastomosing rivers that have laterally stable, non‐meandering channels. We analyzed sedimentary processes using field data, morphology and channel changes trough a temporal analysis using remote sensing data and obtained optically stimulated luminescence (OSL) dating to understand the genesis of this large anastomosing river and the development of its meandering secondary channels. Scroll bars have developed in a multichannel river system at least since 7.5 ± 0.85 ka. Avulsion is inferred to have played a minor role in the formation of this anastomosing system, with only one documented case while mid‐channel bar formation and chute cut‐offs of the main and secondary channels are the main formative mechanisms of anastomosis in this system. Differences in resistance to erosion control the relatively straight main channel and allow secondary channels to develop a meandering platform. Vegetation contributes to the relative stability of islands and the floodplain. Low gradient and high average aggradation rate (1.1 mm yr−1) are conditions which favor the development of anastomosis. Additionally, stable external conditions, low abandonment rate of older channels and independence from high avulsion frequency suggest a long‐lived, semi‐static type of anastomosing river in this reach of the Amazon. Copyright © 2012 John Wiley & Sons, Ltd.
B7‐H3 expression in colorectal cancer: Nuclear localization strongly predicts poor outcome in colon cancer
Authors: Ingebrigtsen Vibeke Anett , Boye Kjetil , Tekle Christina , Nesland Jahn Martin , Flatmark Kjersti , Fodstad Øystein 
Published: April 2012

AbstractIn colorectal cancer there is a need for molecular markers that can complement the histopathological staging in predicting the likelihood of disease recurrence following curatively intended surgery. B7‐H3 is an immunoregulatory protein shown to be overexpressed in several cancer forms, often associated with more advanced disease and poor prognosis. We wanted to examine whether B7‐H3 could be a potential prognostic marker in colorectal cancer. Paraffin‐embedded samples from 277 colorectal cancer patients were immunostained with anti‐B7‐H3 antibody. B7‐H3 was expressed in the tumor cell cytoplasm and cell membrane in 62% and 46% of the samples, respectively. Unexpectedly, B7‐H3 was expressed in the nucleus in 30% of the tumors. The nuclear localization was confirmed by Western immunoblotting of subcellular fractions. Importantly, in colon cancer, nuclear B7‐H3 expression was independently and significantly associated with reduced metastasis‐free, disease‐specific and overall survival. B7‐H3 expression in tumor‐associated vasculature and fibroblasts was observed in the majority of samples, and endothelial B7‐H3 expression was also significantly associated with poor outcome in colon cancer. In rectal cancer patients, the only significant association was between fibroblast B7‐H3 expression and shorter metastasis‐free survival. Few significant associations to clinicopathological parameters were seen. The results indicate that nuclear B7‐H3 might be involved in colon cancer progression and metastasis, and suggest that nuclear B7‐H3 could become a useful prognostic marker in colon cancer.
A comprehensive study of polymorphisms in ABCB1, ABCC2 and ABCG2 and lung cancer chemotherapy response and prognosis
Authors: Campa Daniele , Müller Phillip , Edler Lutz , Knoefel Lena , Barale Roberto , Heussel Claus P. , Thomas Michael , Canzian Federico , Risch Angela 
Published: April 2012

AbstractATP‐binding cassette (ABC) transporter expression and genetic heterogeneity have been implicated in response to anticancer therapy. This study characterized genetic variability of the ABCB1 (also known as MDR1), ABCC2 (MRP2) and ABCG2 (BCRP) genes, which are key players in the metabolism of many chemotherapeutic agents including those used in the treatment of lung cancer. We genotyped 53 polymorphisms in the candidate genes in genomic DNA samples of 171 cases of small cell lung carcinoma (SCLC) and 206 cases of non‐small cell lung carcinoma (NSCLC), and studied their impact on early response to chemotherapy, progression‐free survival and overall survival. SNP rs717620 in ABCC2 was moderately associated with a poor response to chemotherapy but strongly with shorter progression‐free survival and overall survival in SCLC but not NSCLC patients, indicating that ABCC2 genetic variation is an important factor in SCLC survival after chemotherapy.
Influence of uric acid amendment on the in‐vessel process of composting composite food waste
Authors: An Chun‐jiang , Huang Guo‐he , Li Sheng , Yu Hui , Sun Wei , Peng Kuang 
Published: April 2012

AbstractBACKGROUND: The food waste produced in small cities, rural areas and small communities often coexists with agroindustrial waste, such as livestock and poultry manure, which include high levels of uric acid (UA). This study investigated the influence of UA on the composting of food waste in an in‐vessel system.RESULTS: Results showed that the performance of food waste composting was significantly different in systems with UA amendment and without UA amendment. Treatment with UA addition was the first to reach the thermophilic phase. More intensive mass reduction took place in the UA‐amended treatments at an early stage. The variations of pH and O2 uptake were also correlated with the added UA. A decreasing trend in C/N ratio and a general increasing trend for NH$_{4}^{+}$‐N concentration were observed when UA was added.CONCLUSIONS: The overall effect of UA can be assumed to be the sum of a large number of individual events with different mechanisms. Appropriate strategies could be applied to adjust the composting process, mediating both positive and negative effects of the coexistence of food waste and UA as well as manure. The results from this study may have important implications for composting technologies used to treat food waste. Copyright © 2012 Society of Chemical Industry