bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antiquity and geographic distribution of cranial modification among the prehistoric groups of Fuego‐Patagonia, Chile
Authors: Alfonso‐Durrruty Marta P. , Giles Bretton T. , Misarti Nicole , San Roman Manuel , Morello Flavia 
Published: August 2015

ABSTRACTObjectivesNineteenth and twentieth century documents testify that four ethnic groups, generally classified as terrestrial hunters or canoe nomads, inhabited Fuego‐Patagonia. Archaeologically, however, their presence and temporal depth remains unknown. This study analyzes the antiquity and geographic distribution of cranial modification, a highly visible symbol of social identity, in Fuego‐Patagonia, Chile, to assess whether it expressed ethnic affiliation.Materials and MethodsA total of 60 adult skulls from Southern Patagonia (n = 32; 53.3%) and Tierra del Fuego (n = 28; 46.7%) were examined for age‐at‐death, sex and cranial modification with standard methods. Individuals were further categorized as terrestrial (n = 26; 43.3%), marine (n = 21; 35%) or indetermined hunter‐gatherers (n = 13; 21.7%) based on the archaeological site's characteristics, geographic location, and isotopic information.ResultsThirty percent (n = 18) of the skulls in this study were modified, and most of the modified skulls (n = 15) presented a tabular‐erect shape. No statistically significant differences were identified between Fuegians and Patagonians, males or females, or between the different types of adaptation and geographic locations.DiscussionThus, this Late Holocene, widely distributed practice, was not a reflection of ethnicity, but a material expression of information circulation and the complex social relations that these small‐size groups had with one another. These results suggest that the emergence of modern ethnic identities in the region is a historic process that resulted from the interaction of local groups with European and Criollos. Am J Phys Anthropol 158:607–623, 2015. © 2015 Wiley Periodicals, Inc.
Information entropy as a measure of tunneling and quantum confinement in a symmetric double‐well potential
Authors: Mukherjee Neetik , Roy Arunesh , Roy Amlan K. 
Published: August 2015

Information entropic measures such as Fisher information, Shannon entropy, Onicescu energy and Onicescu Shannon entropy of a symmetric double‐well potential are calculated in both position and momentum space. Eigenvalues and eigenvectors of this system are obtained through a variation‐induced exact diagonalization procedure. The information entropy‐based uncertainty relation is shown to be a better measure than conventional uncertainty product in interpreting purely quantum mechanical phenomena, such as, tunneling and quantum confinement in this case. Additionally, the phase‐space description provides a semi‐classical explanation for this feature. Total information entropy and phase‐space area show similar behavior with increasing barrier height.image
Thiophene π‐bridge effect on photovoltaic performances of dithienosilole and bithiazole backboned polymers
Authors: Zheng Huilin , Gu Chuantao , Zhu Qianqian , Bao Xichang , Wen Shuguang , Qiu Meng , Zhu Dangqiang , Sun Mingliang , Yang Renqiang 
Published: August 2015

ABSTRACTIn this article, two dithienosilole (DTS) and bithiazole (BTz) backboned donor–acceptor (D‐A) copolymers with (poly{5‐(5‐(4,4‐bis(2‐ethylhexyl)‐4H‐silolo[3,2‐b:4,5‐b']dithiophen‐2‐yl)thiophen‐2‐yl)‐4,4'‐dinonyl‐5'‐(thiophen‐2‐yl)‐2,2'‐bithiazole} (PDTS‐DTBTz)) and without (poly{5‐(4,4‐bis(2‐ethylhexyl)‐4H‐silolo[3,2‐b:4,5‐b']dithiophen‐2‐yl)‐4,4'‐dinonyl‐2,2'‐bithiazole} (PDTS‐BTz)) thiophene π‐bridge were synthesized to study the influence of thiophene π‐bridge on their photovoltaic performances. Both polymers show similar band gap, but polymer with thiophene π‐bridge (PDTS‐DTBTz) has a higher molecular weight, narrower polydispersity index (PDI), more planar geometry, higher crystallinity, higher hole mobility, and better miscibility with fullerene (polymer solar cells (PSCs) acceptor). Although PDTS‐BTz polymer based PSCs devices show higher open circuit voltage (Voc), PDTS‐DTBTz polymer does show higher power conversion efficiency (PCE) with improved short circuit current density (Jsc) and fill factor (FF). The present results indicate that thiophene π‐bridge does contribute to the PSCs performances of dithienosilole and bithiazole backboned copolymer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42798.
Calcium ion‐mediated grafting of a phosphate‐containing monomer
Authors: Suzuki Shuko , Wentrup‐Byrne Edeline , Chandler‐Temple Adrienne , Shah Nevil , Grøndahl Lisbeth 
Published: August 2015

ABSTRACTGrafting of monoacryloxyethyl phosphate onto expanded polytetrafluoroethylene was achieved using simultaneous grafting with the aim of improving the membrane wettability and mineralization capacity. This study explored the effect of adding calcium ions to the grafting solution and observed increased graft yield and wettability when compared with samples grafted in the absence of calcium ions. Fourier transform infrared spectroscopy mapping found the graft copolymer to be distributed in a patchy manner across the surface as well as throughout the membrane. Through X‐ray photoelectron spectroscopy analysis, it was found that calcium ions were incorporated into the graft copolymer and could be extracted using a basic ethylenediaminetetraacetic acid solution without reduction in graft yield. This implies that the presence of calcium ions is affecting the graft yield by increasing the local concentration of monomer near the surface during the grafting process. Investigation of the mineralization capacity of the grafted membranes in simulated body fluid revealed that the increased wettability of the membranes rather than the presence of the calcium ions affected the mineralization outcome. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42808.
Clarification technologies for monoclonal antibody manufacturing processes: Current state and future perspectives
Authors: Singh Nripen , Arunkumar Abhiram , Chollangi Srinivas , Tan Zhijun George , Borys Michael , Li Zheng Jian 
Published: August 2015

ABSTRACTConsiderable progress has been made increasing productivity of cell cultures to meet the rapidly growing demand for antibody biopharmaceuticals through increased cell densities and longer culture times. This in turn has dramatically increased the burden of process and product related impurities on the purification processes. In addition, current trends in the biopharmaceutical industry point toward both increased productivity and targeting smaller patient populations for new indications. Taken together, these developments are driving the industry to explore alternative separation technologies as a future manufacturing strategy. Clarification technologies well established in other industries, such as flocculation and precipitation are increasingly considered as a viable solution to address this bottleneck in antibody processes. However, several technical issues need to be fully addressed including suitability as a platform application, robustness, process cost, toxicity, and clearance. This review will focus on recent efforts to incorporate new generation clarification technologies for mammalian cell cultures producing monoclonal antibodies as well as challenges to their implementation supported by a case study. Biotechnol. Bioeng. 2016;113: 698–716. © 2015 Wiley Periodicals, Inc.
Development of a bench‐top device for parallel climate‐controlled recordings of neuronal cultures activity with microelectrode arrays
Authors: Regalia Giulia , Biffi Emilia , Achilli Silvia , Ferrigno Giancarlo , Menegon Andrea , Pedrocchi Alessandra 
Published: August 2015

ABSTRACTTwo binding requirements for in vitro studies on long‐term neuronal networks dynamics are (i) finely controlled environmental conditions to keep neuronal cultures viable and provide reliable data for more than a few hours and (ii) parallel operation on multiple neuronal cultures to shorten experimental time scales and enhance data reproducibility. In order to fulfill these needs with a Microelectrode Arrays (MEA)‐based system, we designed a stand‐alone device that permits to uninterruptedly monitor neuronal cultures activity over long periods, overcoming drawbacks of existing MEA platforms. We integrated in a single device: (i) a closed chamber housing four MEAs equipped with access for chemical manipulations, (ii) environmental control systems and embedded sensors to reproduce and remotely monitor the standard in vitro culture environment on the lab bench (i.e. in terms of temperature, air CO2 and relative humidity), and (iii) a modular MEA interface analog front‐end for reliable and parallel recordings. The system has been proven to assure environmental conditions stable, physiological and homogeneos across different cultures. Prolonged recordings (up to 10 days) of spontaneous and pharmacologically stimulated neuronal culture activity have not shown signs of rundown thanks to the environmental stability and have not required to withdraw the cells from the chamber for culture medium manipulations. This system represents an effective MEA‐based solution to elucidate neuronal network phenomena with slow dynamics, such as long‐term plasticity, effects of chronic pharmacological stimulations or late‐onset pathological mechanisms. Biotechnol. Bioeng. 2016;113: 403–413. © 2015 Wiley Periodicals, Inc.
Performance benchmarking of four cell‐free protein expression systems
Authors: Gagoski Dejan , Polinkovsky Mark E. , Mureev Sergey , Kunert Anne , Johnston Wayne , Gambin Yann , Alexandrov Kirill 
Published: August 2015

ABSTRACTOver the last half century, a range of cell‐free protein expression systems based on pro‐ and eukaryotic organisms have been developed and have found a range of applications, from structural biology to directed protein evolution. While it is generally accepted that significant differences in performance among systems exist, there is a paucity of systematic experimental studies supporting this notion. Here, we took advantage of the species‐independent translation initiation sequence to express and characterize 87 N‐terminally GFP‐tagged human cytosolic proteins of different sizes in E. coli, wheat germ (WGE), HeLa, and Leishmania‐based (LTE) cell‐free systems. Using a combination of single‐molecule fluorescence spectroscopy, SDS‐PAGE, and Western blot analysis, we assessed the expression yields, the fraction of full‐length translation product, and aggregation propensity for each of these systems. Our results demonstrate that the E. coli system has the highest expression yields. However, we observe that high expression levels are accompanied by production of truncated species—particularly pronounced in the case of proteins larger than 70 kDa. Furthermore, proteins produced in the E. coli system display high aggregation propensity, with only 10% of tested proteins being produced in predominantly monodispersed form. The WGE system was the most productive among eukaryotic systems tested. Finally, HeLa and LTE show comparable protein yields that are considerably lower than the ones achieved in the E. coli and WGE systems. The protein products produced in the HeLa system display slightly higher integrity, whereas the LTE‐produced proteins have the lowest aggregation propensity among the systems analyzed. The high quality of HeLa‐ and LTE‐produced proteins enable their analysis without purification and make them suitable for analysis of multi‐domain eukaryotic proteins. Biotechnol. Bioeng. 2016;113: 292–300. © 2015 Wiley Periodicals, Inc.
Towards the industrialization of new biosurfactants: Biotechnological opportunities for the lactone esterase gene from Starmerella bombicola
Authors: Roelants Sophie L.K.W. , Ciesielska Katarzyna , De Maeseneire Sofie L. , Moens Helena , Everaert Bernd , Verweire Stijn , Denon Quenten , Vanlerberghe Brecht , Van Bogaert Inge N.A. , Van der Meeren Paul , Devreese Bart , Soetaert Wim 
Published: August 2015

ABSTRACTAlthough sophorolipids (SLs) produced by S. bombicola are a real showcase for the industrialization of microbial biosurfactants, some important drawbacks are associated with this efficient biological process, e.g., the simultaneous production of acidic and lactonic SLs. Depending on the application, there is a requirement for the naturally produced mixture to be manipulated to give defined ratios of the components. Recently, the enzyme responsible for the lactonization of SLs was discovered. The discovery of the gene encoding this lactone esterase (sble) enabled the development of promising S. bombicola strains producing either solely lactonic (using a sble overexpression strain described in this paper: oe sble) or solely acidic SLs (using a sble deletion strain, which was recently described, but not characterized yet: Δsble). The new S. bombicola strains were used to investigate the production processes (fermentation and purification) of either lactonic or acidic SLs. The strains maintain the high inherent productivities of the wild‐type or even perform slightly better and thus represent a realistic industrial opportunity. 100% acidic SLs with a mixed acetylation pattern were obtained for the Δsble strain, while the inherent capacity to selectively produce lactonic SLs was significantly increased (+42%) for the oe sble strain (99% lactonic SLs). Moreover, the regulatory effect of citrate on lactone SL formation for the wild‐type was absent in this new strain, which indicates that it is more robust and better suited for the industrial production of lactonic SLs. Basic parameters were determined for the purified SLs, which confirm that the two new strains produce molecules with distinctive properties of which the application potential can now easily be investigated independently. Biotechnol. Bioeng. 2016;113: 550–559. © 2015 Wiley Periodicals, Inc.
Physiological effects of pH gradients on Escherichia coli during plasmid DNA production
Authors: Cortés José T. , Flores Noemí , Bolívar Francisco , Lara Alvaro R. , Ramírez Octavio T. 
Published: August 2015

ABSTRACTA two‐compartment scale‐down system was used to mimic pH heterogeneities that can occur in large‐scale bioreactors. The system consisted of two interconnected stirred tank reactors (STRs) where one of them represented the conditions of the bulk of the fluid and the second one the zone of alkali addition for pH control. The working volumes ratio of the STRs was set to 20:1 in order to simulate the relative sizes of the bulk and alkali addition zones, respectively, in large‐scale bioreactors. Residence times (tR) in the alkali addition STR of 60, 120, 180, and 240 s were simulated during batch cultures of an engineered Escherichia coli strain that produced plasmid DNA (pDNA). pH gradients of up to 0.9 units, between the two compartments, were attained. The kinetic, stoichiometric, and pDNA topological changes due to the pH gradients were studied and compared to cultures at constant pH of 7.2 and 8.0. As the tR increased, the pDNA and biomass yields, as well as pDNA final titer decreased, whereas the accumulation of organic acids increased. Furthermore, the transcriptional response of 10 selected genes to alkaline stress (pH 8.0) and pH gradients was monitored at different stages of the cultures. The selected genes coded for ion transporters, amino acids catabolism enzymes, and transcriptional regulators. The transcriptional response of genes coding for amino acids catabolism, in terms of relative transcription level and stage of maximal expression, was different when the alkaline stress was constant or transient. This suggests the activation of different mechanisms by E. coli to cope with pH fluctuations compared to constant alkaline pH. Moreover, the transcriptional response of genes related to negative control of DNA synthesis did not correlate with the lower pDNA yields. This is the first study that reports the effects of pH gradients on pDNA production by E. coli cultures. The information presented can be useful for the design of better bioreactor scale‐up strategies. Biotechnol. Bioeng. 2016;113: 598–611. © 2015 Wiley Periodicals, Inc.
Isolation and Biosynthesis of an Azoxyalkene Compound Produced by a Multiple Gene Disruptant of Streptomyces rochei
Authors: Kunitake Hirofumi , Hiramatsu Takahiro , Kinashi Haruyasu , Arakawa Kenji 
Published: August 2015

AbstractStreptomyces rochei 7434AN4 predominantly produces lankacidin and lankamycin under normal culture conditions, thus suggesting that other biosynthetic gene clusters for secondary metabolites are silent. To identify the silent metabolites of 7434AN4, we constructed mutant KA57 with multiple disruptions of the transcriptional repressor srrB and the biosynthesis genes for both antibiotics. KA57 accumulated a compound (KA57A) with a strong UV absorption at 235 nm, not detected in the parent strain or other mutants. Various spectroscopic analyses revealed that KA57A is an azoxyalkene compound with the molecular formula C10H20N2O3 and with the R configuration at C‐2. Biosynthesis of KA57A was also studied by feeding with labeled acetates, amino acids, and 1‐hexylamine. The hexenyl moiety (C1′–C6′) was derived from fatty acid, whereas the 3‐aminobutan‐1,2‐diol moiety (C1–C4) was derived from C‐2 of acetate (C1) and serine (C2–C4). Incorporation of [1,1‐2H2]‐1‐hexylamine indicated that C1′–C2′ dehydrogenation occurs as the final step of biosynthesis.
Tuning the Surface Chemistry of Nanoporous Carbons for Enhanced Nanoconfined Photochemical Activity
Authors: Velasco Leticia F. , Gomis‐Berenguer Alicia , Lima Joao C. , Ania Conchi O. 
Published: August 2015

AbstractWe showed the effect of surface oxidation on the conversion of light into a chemical reaction in the confined pore space of nanoporous carbons. The photoactivity of carbons is caused by the combination of high porosity and the presence of photoreactive sites that favor the splitting of the exciton inside the pores, which boosts its efficient use in chemical reactions. The incorporation of O‐containing groups in the carbon matrix decreased the photoconversion inside the pores, although values were higher than those attained in solution. This is attributed to the lower stabilization of the exciton through the delocalization within the conjugated sp2 network of the basal planes because of the electron‐withdrawing effect of the O‐containing groups. The photochemical conversion of light inside the pores is very sensitive to the acidic/basic nature of the O‐containing groups of the carbon matrix, and can be enhanced by balancing the surface composition, porosity, and electronic mobility.
Chirality Sensing With Stereodynamic Biphenolate Zinc Complexes
Authors: Bentley Keith W. , de los Santos Zeus A. , Weiss Mary J. , Wolf Christian 
Published: August 2015

AbstractTwo bidentate ligands consisting of a fluxional polyarylacetylene framework with terminal phenol groups were synthesized. Reaction with diethylzinc gives stereodynamic complexes that undergo distinct asymmetric transformation of the first kind upon binding of chiral amines and amino alcohols. The substrate‐to‐ligand chirality imprinting at the zinc coordination sphere results in characteristic circular dichroism signals that can be used for direct enantiomeric excess (ee) analysis. This chemosensing approach bears potential for high‐throughput ee screening with small sample amounts and reduced solvent waste compared to traditional high‐performance liquid chromatography methods. Chirality 27:700–707, 2015. © 2015 Wiley Periodicals, Inc.
Design and simulation of a multilayer Halbach magnet for NMR
Authors: Chen Qiaoyan , Zhang Guangcai , Xu Yajie , Yang Xiaodong 
Published: August 2015

ABSTRACTHalbach magnet is a type of permanent magnet generating a relatively high and homogeneous magnetic field. It is suitable for Nuclear Magnetic Resonance (NMR) studies of small volume chemical or biological samples. In this article, the model of a Halbach magnet made from an odd number of cylindrical layers is proposed for the first time. Then after the optimization of interlayer distances for odd layers Halbach cylinders, the model is verified by the simulation with a magnet inner radius of 30 mm and an outer radius of 49 mm. Moreover, the disturbance of uniformity in 5 mm DSV (Diameter of Spherical Volume) is presented with errors in magnetic strength and angular variation. As a result, a minimum uniformity of 46 ppm inside a 5 mm DSV is achieved, while it increases practically in the presence of magnetic blocks errors. The good performance of the Halbach magnet with odd layers may find potential applications in NMR. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 45B: 134–141, 2015
Comparison of soil microbial communities inhabiting vineyards and native sclerophyllous forests in central Chile
Authors: Castañeda Luis E. , Godoy Karina , Manzano Marlene , Marquet Pablo A. , Barbosa Olga 
Published: August 2015

AbstractNatural ecosystems provide services to agriculture such as pest control, soil nutrients, and key microbial components. These services and others in turn provide essential elements that fuel biomass productivity. Responsible agricultural management and conservation of natural habitats can enhance these ecosystem services. Vineyards are currently driving land‐use changes in many Mediterranean ecosystems. These land‐use changes could have important effects on the supporting ecosystems services related to the soil properties and the microbial communities associated with forests and vineyard soils. Here, we explore soil bacterial and fungal communities present in sclerophyllous forests and organic vineyards from three different wine growing areas in central Chile. We employed terminal restriction fragment length polymorphisms (T‐RFLP) to describe the soil microbial communities inhabiting native forests and vineyards in central Chile. We found that the bacterial community changed between the sampled growing areas; however, the fungal community did not differ. At the local scale, our findings show that fungal communities differed between habitats because fungi species might be more sensitive to land‐use change compared to bacterial species, as bacterial communities did not change between forests and vineyards. We discuss these findings based on the sensitivity of microbial communities to soil properties and land‐use change. Finally, we focus our conclusions on the importance of naturally derived ecosystem services to vineyards.