bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mesoporous Silicon‐PLGA Composite Microspheres for the Double Controlled Release of Biomolecules for Orthopedic Tissue Engineering
Authors: Fan Dongmei , De Rosa Enrica , Murphy Matthew B. , Peng Yang , Smid Christine A. , Chiappini Ciro , Liu Xuewu , Simmons Paul , Weiner Bradley K. , Ferrari Mauro , Tasciotti Ennio 
Published: October 2011

AbstractIn this study, poly(dl‐lactide‐co‐glycolide)/porous silicon (PLGA/pSi) composite microspheres, synthesized by a solid‐in‐oil‐in‐water (S/O/W) emulsion method, are developed for the long‐term controlled delivery of biomolecules for orthopedic tissue engineering applications. Confocal and fluorescent microscopy, together with material analysis, show that each composite microsphere contained multiple pSi particles embedded within the PLGA matrix. The release profiles of fluorescein isothiocyanate (FITC)‐labeled bovine serum albumin (FITC‐BSA), loaded inside the pSi within the PLGA matrix, indicate that both PLGA and pSi contribute to the control of the release rate of the payload. Protein stability studies show that PLGA/pSi composite can protect BSA from degradation during the long term release. We find that during the degradation of the composite material, the presence of the pSi particles neutralizes the acidic pH due to the PLGA degradation by‐products, thus minimizing the risk of inducing inflammatory responses in the exposed cells while stimulating the mineralization in osteogenic growth media. Confocal studies show that the cellular uptake of the composite microspheres is avoided, while the fluorescent payload is detectable intracellularly after 7 days of co‐incubation. In conclusion, the PLGA/pSi composite microspheres offer an additional level of controlled release and could be ideal candidates as drug delivery vehicles for orthopedic tissue engineering applications.
Quantitative Analysis of Bulk Heterojunction Films Using Linear Absorption Spectroscopy and Solar Cell Performance
Authors: Turner Sarah T. , Pingel Patrick , Steyrleuthner Robert , Crossland Edward J. W. , Ludwigs Sabine , Neher Dieter 
Published: October 2011

AbstractA fundamental understanding of the relationship between the bulk morphology and device performance is required for the further development of bulk heterojunction organic solar cells. Here, non‐optimized (chloroform cast) and nearly optimized (solvent‐annealed o‐dichlorobenzene cast) P3HT:PCBM blend films treated over a range of annealing temperatures are studied via optical and photovoltaic device measurements. Parameters related to the P3HT aggregate morphology in the blend are obtained through a recently established analytical model developed by F. C. Spano for the absorption of weakly interacting H‐aggregates. Thermally induced changes are related to the glass transition range of the blend. In the chloroform prepared devices, the improvement in device efficiency upon annealing within the glass transition range can be attributed to the growth of P3HT aggregates, an overall increase in the percentage of chain crystallinity, and a concurrent increase in the hole mobilities. Films treated above the glass transition range show an increase in efficiency and fill factor not only associated with the change in chain crystallinity, but also with a decrease in the energetic disorder. On the other hand, the properties of the P3HT phase in the solvent‐annealed o‐dichlorobenzene cast blends are almost indistinguishable from those of the corresponding pristine P3HT layer and are only weakly affected by thermal annealing. Apparently, slow drying of the blend allows the P3HT chains to crystallize into large domains with low degrees of intra‐ and interchain disorder. This morphology appears to be most favorable for the efficient generation and extraction of charges.
Nonisocyanate polyurethane/silica hybrid coatings via a sol–gel route
Authors: Hosgor Z. , Kayaman‐Apohan N. , Karatas S. , Gungor A. , Menceloglu Y. 
Published: October 2011

AbstractPolyurethane/silica hybrids by a nonisocyanate route were prepared by reacting cyclic carbonate‐modified bis(4‐glycidyloxy phenyl)phenyl phosphine oxide (BGPPO), and poly(propyleneglycol)diglycidyl ether (PPG‐DGE) with hexamethylene diamine. The incorporation of silica was achieved via a sol–gel method. The effect of silica and phosphine oxide moiety on polyurethane coating properties was studied by physical, mechanical, and thermal tests. Modulus and hardness of the coatings were enhanced by increasing the amount of silica and phosphine oxide based resin. The improvement in flame retardancy and thermal stability of nanocomposites was proved with increased char yield values and decomposition temperatures in thermogravimetric analyses. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 31: 390–400, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20262
Biological and epidemiological evidence of interaction of infant genotypes at Rs7205289 and maternal passive smoking in cleft palate
Authors: Li Ling , Zhu Gui‐quan , Meng Tian , Shi Jia‐yu , Wu Jun , Xu Xue , Shi Bing 
Published: October 2011

AbstractThe noncoding SNP rs7205289, located in the microRNA‐140 gene has been associated with cleft palate risk. MiR‐140 was found to regulate zebrafish palatal development in vivo and its expression level be reduced by environmental smoke exposure in vitro. Therefore, we sought to investigate whether the A allele of rs7205289 and maternal smoke exposure during the first trimester might contribute to cleft palate risk by regulating microRNA‐140. We used in situ hybridization to explore the microRNA‐140 expression pattern. A luciferase reporting system and Western blot were used to validate the target of microRNA‐140. Mouse palatal mesenchymal cells (MPMC) were transfected with microRNA‐140 expression vectors, or treated with cigarette smoke extract. In addition, we performed a hospital‐based case–control study in 169 patients with nonsyndromic cleft palate and 306 unaffected controls. We demonstrated microRNA‐140 expression in mouse palatal shelves from embryonic days 12 to 15. Pdgfrα was the target of microRNA‐140 in MPMC. When these cells were transfected with the minor allele vector or exposed to cigarette smoke extract, they showed a decrease in microRNA‐140 expression. Epidemiological analyses showed that infants with CA/AA genotypes and exposed to maternal passive smoking during pregnancy had evidence of synergistic interaction in contributing to cleft palate risk. We concluded that infants with CA/AA genotypes at rs7205289 and maternal passive smoking during the first trimester may synergistically contribute to cleft palate risk by decreasing microRNA‐140 during palatal development. © 2011 Wiley Periodicals, Inc.
Origins of electromagnetic hypersensitivity to 60 Hz magnetic fields: A provocation study
Authors: Kim Deok Won , Choi Jae Lim , Nam Ki Chang , Yang Dong In , Kwon Min Kyung 
Published: October 2011

AbstractWith increasing electrical device usage, social concerns about the possible effects of 60 Hz electromagnetic fields on human health have increased. The number of people with self‐attributed electromagnetic hypersensitivity (EHS) who complain of various subjective symptoms such as headache and insomnia has also increased. However, it is unclear whether EHS results from physiological or other origins. In this double‐blinded study, we simultaneously investigated physiological changes (heart rate, respiration rate, and heart rate variability), subjective symptoms, and perception of the magnetic field to assess origins of the subjective symptoms. Two volunteer groups of 15 self‐reported EHS and 16 non‐EHS individuals were tested with exposure to sham and real (60 Hz, 12.5 µT) magnetic fields for 30 min. Magnetic field exposure did not have any effects on physiological parameters or eight subjective symptoms in either group. There was also no evidence that the EHS group perceived the magnetic field better than the non‐EHS group. In conclusion, the subjective symptoms did not result from the 60 Hz, 12.5 µT magnetic field exposures but from other non‐physiological factors. Bioelectromagnetics 33:326–333, 2012. © 2011 Wiley Periodicals, Inc.
Complex permittivity of representative biological solutions in the 2–67 GHz range
Authors: Zhadobov Maxim , Augustine Robin , Sauleau Ronan , Alekseev Stanislav , Di Paola Alessandra , Le Quément Catherine , Mahamoud Yonis Soubere , Le Dréan Yves 
Published: October 2011

AbstractThe main purpose of this study is to provide experimental data on the complex permittivity of some biological solutions in the 2–67 GHz range at room and human body temperatures. The permittivity measurements are performed using an open‐ended coaxial probe. Permittivity spectra of several representative monomolecular solutions of proteins, amino acids, nucleic acids, and carbohydrates are analyzed and compared. Furthermore, measurements have also been performed for complex biomolecular solutions, including bovine serum albumin (BSA)–DNA–glucose mixture, culture medium, and yeast extract solution. The results demonstrate that for concentrations below 1%, the permittivity spectra of the solutions do not substantially differ from that of distilled water. Measurements carried out for 4% and 20% BSA solutions show that the presence of proteins results in a decrease in permittivity. For highly concentrated RNA solutions (3%), a slight increase in the imaginary part of the permittivity is observed below 10 GHz. Experimental data show that free water permittivity can be used for modeling of the culture medium above 10 GHz. However, at lower frequencies a substantial increase in the imaginary part of the permittivity due to ionic conductivity should be carefully taken into account. A similar increase has also been observed for the yeast extract solution in the lower frequency region of the considered spectrum. Above 10 GHz, the high concentration of proteins and other low‐permittivity components of the yeast extract solution results in a decrease in the complex permittivity compared to that of water. Obtained data are of utmost importance for millimeter‐wave dosimetry studies. Bioelectromagnetics 33:346–355, 2012. © 2011 Wiley Periodicals, Inc.
Mitochondrial dysfunction and Down's syndrome: Is there a role for coenzyme Q10?
Authors: Tiano Luca , Busciglio Jorge 
Published: October 2011

AbstractStructural changes and abnormal function of mitochondria have been documented in Down's syndrome (DS) cells, patients, and animal models. DS cells in culture exhibit a wide array of functional mitochondrial abnormalities including reduced mitochondrial membrane potential, reduced ATP production, and decreased oxido‐reductase activity. New research has also brought to central stage the prominent role of oxidative stress in this condition. This review focuses on recent advances in the field with a particular emphasis on novel translational approaches involving the utilization of coenzyme Q10 (CoQ10) to treat a variety of clinical phenotypes associated with DS that are linked to increased oxidative stress and energy deficits. CoQ10 has already provided promising results in several different conditions associated with altered energy metabolism and oxidative stress in the CNS. Two studies conducted in Ancona investigated the effect of CoQ10 treatment on DNA damage in DS patients. Although the effect of CoQ10 was evidenced only at single cell level, the treatment affected the distribution of cells according to their content in oxidized bases. In fact, it produced a strong negative correlation linking cellular CoQ10 content and the amount of oxidized purines. Results suggest that the effect of CoQ10 treatment in DS not only reflects antioxidant efficacy, but likely modulates DNA repair mechanisms.
Albumin handling by renal tubular epithelial cells in a microfluidic bioreactor
Authors: Ferrell Nicholas , Ricci Kevin B. , Groszek Joseph , Marmerstein Joseph T. , Fissell William H. 
Published: October 2011

AbstractEpithelial cells in the proximal tubule of the kidney reclaim and metabolize protein from the glomerular filtrate. Proteinuria, an overabundance of protein in the urine, affects tubular cell function and is a major factor in the progression of chronic kidney disease. By developing experimental systems to study tubular protein handling in a setting that simulates some of the environmental conditions of the kidney tubule in vivo, we can better understand how microenviromental conditions affect cellular protein handling to determine if these conditions are relevant in disease. To this end, we used two in vitro microfluidic models to evaluate albumin handling by renal proximal tubule cells. For the first system, cells were grown in a microfluidic channel and perfused with physiological levels of shear stress to evaluate the effect of mechanical stress on protein uptake. In the second system, a porous membrane was used to separate an apical and basolateral compartment to evaluate the fate of protein following cellular metabolism. Opossum kidney (OK) epithelial cells were exposed to fluorescently labeled albumin, and cellular uptake was determined by measuring the fluorescence of cell lysates. Confocal fluorescence microscopy was used to compare uptake in cells grown under flow and static conditions. Albumin processed by the cells was examined by size exclusion chromatography (SEC) and SDS–PAGE. Results showed that cellular uptake and/or degradation was significantly increased in cells exposed to flow compared to static conditions. This was confirmed by confocal microscopy. Size exclusion chromatography and SDS–PAGE showed that albumin was broken down into small molecular weight fragments and excreted by the cells. No trace of intact albumin was detectable by either SEC or SDS–PAGE. These results indicate that fluid shear stress is an important factor mediating cellular protein handling, and the microfluidic bioreactor provides a novel tool to investigate this process. Biotechnol. Bioeng. 2012; 109:797–803. © 2011 Wiley Periodicals, Inc.
Removal versus fragmentation of amyloid‐forming precursors via membrane filtration
Authors: Posada David , Tessier Peter M. , Hirsa Amir H. 
Published: October 2011

AbstractThe presence of even minute amounts of protein aggregates in solution can significantly alter the kinetics of amyloid formation. Removal of such pre‐existing aggregates is critical for reproducible analysis of amyloid formation. Here we examine the effects of membrane filtration on insulin fibrillization. We find that filtration of insulin with large pore membranes (≥100 nm) generally slows fibril formation relative to unfiltered solutions by removing pre‐aggregated protein. Unexpectedly, filtration with small pore membranes (<100 nm) showed no beneficial effect and, in some cases, accelerated insulin fibril formation. This effect may be due to fragmentation of pre‐existing aggregates during filtration through small pore membranes, which can increase the number of amyloid‐forming precursors. These findings reveal the complexity of removing protein aggregates via filtration and suggest optimal filtration protocols for conducting fibril formation analysis of insulin and similar amyloidogenic proteins. Biotechnol. Bioeng. 2012; 109:840–845. © 2011 Wiley Periodicals, Inc.
Preventing spontaneous genetic rearrangements in the transgene cassettes of adenovirus vectors
Authors: Cottingham Matthew G. , Carroll Fionnadh , Morris Susan J. , Turner Alison V. , Vaughan Aisling M. , Kapulu Melissa C. , Colloca Stefano , Siani Loredana , Gilbert Sarah C. , Hill Adrian V.S. 
Published: October 2011

AbstractFirst‐generation, E1/E3‐deleted adenoviral vectors with diverse transgenes are produced routinely in laboratories worldwide for development of novel prophylactics and therapies for a variety of applications, including candidate vaccines against important infectious diseases, such as HIV/AIDS, tuberculosis, and malaria. Here, we show, for two different transgenes (both encoding malarial antigens) inserted at the E1 locus, that rare viruses containing a transgene‐inactivating mutation exhibit a selective growth advantage during propagation in E1‐complementing HEK293 cells, such that they rapidly become the major or sole species in the viral population. For one of these transgenes, we demonstrate that viral yield and cytopathic effect are enhanced by repression of transgene expression in the producer cell line, using the tetracycline repressor system. In addition to these transgene‐inactivating mutations, one of which occurred during propagation of the pre‐viral genomic clone in bacteria, and the other after viral reconstitution in HEK293 cells, we describe two other types of mutation, a small deletion and a gross rearranging duplication, in one of the transgenes studied. These were of uncertain origin, and the effects on transgene expression and viral growth were not fully characterized. We demonstrate that, together with minor protocol modifications, repression of transgene expression in HEK293 cells during viral propagation enables production of a genetically stable chimpanzee adenovirus vector expressing a malarial antigen which had previously been impossible to derive. These results have important implications for basic and pre‐clinical studies using adenoviral vectors and for derivation of adenoviral vector products destined for large‐scale amplification during biomanufacture. Biotechnol. Bioeng. 2012; 109:719–728. © 2011 Wiley Periodicals, Inc.
Collisional fragmentation of central carbon metabolites in LC‐MS/MS increases precision of 13C metabolic flux analysis
Authors: Rühl Martin , Rupp Beat , Nöh Katharina , Wiechert Wolfgang , Sauer Uwe , Zamboni Nicola 
Published: October 2011

AbstractExperimental determination of fluxes by 13C‐tracers relies on detection of 13C‐patterns in metabolites or by‐products. In the field of 13C metabolic flux analysis, the most recent developments point toward recording labeling patterns by liquid chromatography (LC)‐mass spectrometry (MS)/MS directly in intermediates in central carbon metabolism (CCM) to increase temporal resolution. Surprisingly, the flux studies published so far with LC‐MS measurements were based on intact metabolic intermediates—thus neglected the potential benefits of using positional information to improve flux estimation. For the first time, we exploit collisional fragmentation to obtain more fine‐grained 13C‐data on intermediates of CCM and investigate their impact in 13C metabolic flux analysis. For the case study of Bacillus subtilis grown in mineral medium with 13C‐labeled glucose, we compare the flux estimates obtained by iterative isotopologue balancing of 13C‐data obtained either by LC‐MS/MS for solely intact intermediates or LC‐MS/MS for intact and fragmented intermediates of CCM. We show that with LC‐MS/MS data, fragment information leads to more precise estimates of fluxes in pentose phosphate pathway, glycolysis, and to the tricarboxylic acid cycle. Additionally, we present an efficient analytical strategy to rapidly acquire large sets of 13C‐patterns by tandem MS, and an in‐depth analysis of the collisional fragmentation of primary intermediates. In the future, this catalogue will enable comprehensive in silico calculability analyses to identify the most sensitive measurements and direct experimental design. Biotechnol. Bioeng. 2012; 109:763–771. © 2011 Wiley Periodicals, Inc.
Effect of various factors on ethanol yields from lignocellulosic biomass by Thermoanaerobacterium AK17
Authors: Almarsdottir Arnheidur Ran , Sigurbjornsdottir Margret Audur , Orlygsson Johann 
Published: October 2011

AbstractThe ethanol production capacity from sugars and lignocellulosic biomass hydrolysates (HL) by Thermoanaerobacterium strain AK17 was studied in batch cultures. The strain converts various carbohydrates to, acetate, ethanol, hydrogen, and carbon dioxide. Ethanol yields on glucose and xylose were 1.5 and 1.1 mol/mol sugars, respectively. Increased initial glucose concentration inhibited glucose degradation and end product formation leveled off at 30 mM concentrations. Ethanol production from 5 g L−1 of complex biomass HL (grass, hemp, wheat straw, newspaper, and cellulose) (Whatman paper) pretreated with acid (0.50% H2SO4), base (0.50% NaOH), and without acid/base (control) and the enzymes Celluclast® and Novozyme 188 (0.1 mL g−1 dw; 70 and 25 U g−1 of Celluclast and Novozyme 188, respectively) was investigated. Highest ethanol yields (43.0 mM) were obtained on cellulose but lowest on hemp leafs (3.6 mM). Chemical pretreatment increased ethanol yields substantially from lignocellulosic biomass but not from cellulose. The influence of various factors (HL, enzyme, and acid/alkaline concentrations) on end‐product formation from 5 g L−1 of grass and cellulose was further studied to optimize ethanol production. Highest ethanol yields (5.5 and 8.6 mM ethanol g−1 grass and cellulose, respectively) were obtained at very low HL concentrations (2.5 g L−1); with 0.25% acid/alkali (v/v) and 0.1 mL g−1 enzyme concentrations. Inhibitory effects of furfural and hydroxymethylfurfural during glucose fermentation, revealed a total inhibition in end product formation from glucose at 4 and 6 g L−1, respectively. Biotechnol. Bioeng. 2012; 109:686–694. © 2011 Wiley Periodicals, Inc.
Construction of BAC‐based physical map and analysis of chromosome rearrangement in chinese hamster ovary cell lines
Authors: Cao Yihua , Kimura Shuichi , Itoi Takayuki , Honda Kohsuke , Ohtake Hisao , Omasa Takeshi 
Published: October 2011

AbstractChinese hamster ovary (CHO) cells have frequently been used in biotechnology for many years as a mammalian host cell platform for cloning and expressing genes of interest. A detailed physical chromosomal map of the CHO DG44 cell line was constructed by fluorescence in situ hybridization (FISH) imaging using randomly selected 303 BAC clones as hybridization probes (BAC‐FISH). The two longest chromosomes were completely paired chromosomes; other chromosomes were partly deleted or rearranged. The end sequences of 624 BAC clones, including 287 mapped BAC clones, were analyzed and 1,119 informative BAC end sequences were obtained. Among 303 mapped BAC clones, 185 clones were used for BAC‐FISH analysis of CHO K1 chromosomes and 94 clones for primary Chinese hamster lung cells. Based on this constructed physical map and end sequences, the chromosome rearrangements between CHO DG44, CHO K1, and primary Chinese hamster cells were investigated. Among 20 CHO chromosomes, eight were conserved without large rearrangement in CHO DG44, CHO K1, and primary Chinese hamster cells. This result suggested that these chromosomes were stable and essential in CHO cells and supposedly conserved in other CHO cell lines. Biotechnol. Bioeng. 2012; 109:1357–1367. © 2011 Wiley Periodicals, Inc.