bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphene oxide–mediated electrochemistry of glucose oxidase on glassy carbon electrodes
Authors: Castrignanò Silvia , Valetti Francesca , Gilardi Gianfranco , Sadeghi Sheila J. 
Published: May 2015

AbstractGlucose oxidase (GOD) was immobilized on glassy carbon electrodes in the presence of graphene oxide (GO) as a model system for the interaction between GO and biological molecules. Lyotropic properties of didodecyldimethylammonium bromide (DDAB) were used to stabilize the enzymatic layer on the electrode surface resulting in a markedly improved electrochemical response of the immobilized GOD. Transmission electron microscopy images of the GO with DDAB confirmed the distribution of the GO in a two‐dimensional manner as a foil‐like material. Although it is known that glassy carbon surfaces are not ideal for hydrogen peroxide detection, successful chronoamperometric titrations of the GOD in the presence of GO with β‐d‐glucose were performed on glassy carbon electrodes, whereas no current response was detected upon β‐d‐glucose addition in the absence of GO. The GOD–DDAB–GO system displayed a high turnover efficiency and substrate affinity as a glucose biosensor. The simplicity and ease of the electrode preparation procedure of this GO/DDAB system make it a good candidate for immobilizing other biomolecules for fabrication of amperometric biosensors.
High‐throughput sequencing reveals adaptation‐induced mutations in pentose‐fermenting strains of Zymomonas mobilis
Authors: Dunn Kori L. , Rao Christopher V. 
Published: May 2015

ABSTRACTZymomonas mobilis is capable of producing ethanol at high rates and titers from glucose. This bacterium has previously been engineered to consume the pentose sugars xylose and arabinose, but the rate of consumption of these sugars is low. Recent research has utilized adaptive evolution to isolate strains of Z. mobilis capable of rapidly fermenting xylose. In this study, we also used adaptive evolution to isolate strains of Z. mobilis capable of rapidly fermenting xylose and arabinose. To determine the bottlenecks in pentose metabolism, we then used high‐throughput sequencing to pinpoint the genetic changes responsible for the phenotypes of the adapted strains. We found that the transport of both xylose and arabinose through the native sugar transporter, Glf, limits pentose fermentations in Z. mobilis. We also found that mutations in the AddB protein increase plasmid stability and can reduce cellular aggregation in these strains. Consistent with previous research, we found that reduced xylitol production improves xylose fermentations in Z. mobilis. We also found that increased transketolase activity and reduced glyceraldehyde‐3‐phosphate dehydrogenase activity improve arabinose fermentations in Z. mobilis. Biotechnol. Bioeng. 2015;112: 2228–2240. © 2015 Wiley Periodicals, Inc.
Characterization and mitigation of nitrous oxide (N2O) emissions from partial and full‐nitrification BNR processes based on post‐anoxic aeration control
Authors: Brotto Ariane Coelho , Li Huosheng , Dumit Muriel , Gabarró Jordi , Colprim Jesús , Murthy Sudhir , Chandran Kartik 
Published: May 2015

ABSTRACTIt has been reported that a directional change from anoxic to aerobic conditions is a common trigger for nitrous oxide (N2O) production by ammonia oxidizing bacteria (AOB). By extension, during anoxic–aerobic cycling, post‐anoxic dissolved oxygen (DO) concentrations might likely play a role in the magnitude of N2O emissions observed. The overall goal of this study was to determine the impact of three select post‐anoxic DO concentrations (0.8, 2.0, and 3.0 mg O2/L) on N2O emissions from partial‐nitrification (PN) and full‐nitrification (FN) reactors subjected to anoxic–aerobic cycling and, ultimately, to explore the development of strategies to minimize N2O emissions from PN and FN based biological nitrogen removal (BNR) processes. Statistically similar N2O emissions were observed during anoxia for both PN (0.62 ± 0.21% N load) and FN (0.61 ± 0.070% N load) processes. In contrast, N2O emissions were statistically lower for PN (0.86 ± 0.25% N load) than for FN (4.6 ± 2.8% N load), during the post‐anoxic aerobic phase, when compared together for all three post‐anoxic DO concentrations. Further, for PN, the highest N2O emissions were observed at the highest post‐anoxic DO concentration of 3.0 mg O2/L (1.2% N load), likely due to the highest corresponding AOB specific growth rate. In contrast, for FN, the highest N2O emissions were at the lowest post‐anoxic DO concentration of 0.8 mg O2/L (8.5% N load). The higher emissions from FN process at low DO concentrations were associated with a lag in nitrite oxidizing bacteria activity upon recovery to aerobic conditions. This lag phase contributed to transient nitrite accumulation, and in turn correlated positively to the observed N2O emissions. Based on our findings, a gradual ramp up in post‐anoxic DO concentrations can minimize N2O emissions during PN‐based BNR, whereas a completely different strategy, entailing a rapid increase in post‐anoxic DO concentrations can minimize emissions during FN‐based BNR operations. Biotechnol. Bioeng. 2015;112: 2241–2247. © 2015 Wiley Periodicals, Inc.
Photoracemization of Blestriarene C and Its Analogs
Authors: Natori Koichi , Iwayama Taizo , Yamabe Osamu , Kitamoto Yuichi , Ikeda Hiroshi , Sakamoto Kenkichi , Hattori Tetsutaro , Miyano Sotaro 
Published: May 2015

AbstractTwo analogs of blestriarene C (4,4'‐dimethoxy‐1,1'‐biphenanthrene‐2,2',7,7'‐tetraol) bearing no 7,7'‐dihydroxy (3) and 4,4'‐dimethoxy groups 4 were prepared. Unlike blestriarene C (1), compounds 3 and 4, as well as 1,1'‐biphenanthrene‐2,2'‐diol (5), do not racemize under fluorescent lamp illumination. Cyclic voltammetry analysis reveals that compound 1 has a lower half‐wave potential (E1/2) than compounds 3, 4, 5, suggesting that a redox cycle is involved in the racemization. Compound 1 racemizes by absorbing UV light corresponding to the 1Lb band. During the reaction, no side products are observed. The racemization is significantly inhibited under nitrogen. Based on these observations, we propose a feasible mechanism for the easy racemization of compound 1, which is mediated by a cation radical generated in situ by a reversible photo‐induced oxygen oxidation. Chirality 27:479–486, 2015. © 2015 Wiley Periodicals, Inc.
Numerische und analytische Beschreibung der mechanischen Eigenschaften quasi‐tetraederförmiger Agglomerate
Authors: Müller Peter , Glöckner Hannes , Tomas Jürgen 
Published: May 2015

AbstractQuasi‐tetraederförmige Agglomerate bestehen aus vier kugelförmigen Primärpartikeln, von denen drei Primärpartikel generell eine Grundfläche bilden, auf der, im Idealfall gleich großer Primärpartikelradien, das vierte Primärpartikel zentrisch angeordnet ist. In dieser Arbeit werden die Mittelpunktskoordinaten der Primärpartikel für Agglomerate verschiedener Primärpartikelradien hergeleitet. Zudem wird basierend auf dem Hertz‐Modell ein analytisches Modell bei elastischer Kontaktdeformation hergeleitet und evaluiert. Mittels der Diskrete‐Elemente‐Methode wird der Aufbau tetraederförmiger Agglomerate modelliert, die Druckbeanspruchung zwischen zwei steifen Platten simuliert und die Ergebnisse mit experimentellen Daten verglichen.
Methyl Group in Isocopalane Derivative Showed an Unusual Negative 1H NMR Chemical Shift
Authors: Xiao Xiong , Chen Tianqi , Zhang Fengfeng , Cheng Jiagao , Wu Peiying , Ren Jiangmeng , Zeng Bubing 
Published: May 2015

AbstractAn unusual negative 1H NMR chemical shif of methyl group was discovered in condensation product of isocopalane diterpenoid with p‐toluenesulfonyl hydrazide. 2D NMR, computational studies and single‐crystal X‐ray diffraction analysis showed that the C‐20 methyl group was shielded.
Understanding the Aldo‐Enediolate Tautomerism of Glycolaldehyde in Basic Aqueous Solutions
Authors: Azofra Luis Miguel , Quesada‐Moreno María Mar , Alkorta Ibon , Avilés‐Moreno Juan Ramón , Elguero José , López‐González Juan Jesús 
Published: May 2015

AbstractThe biochemically important interconversion process between aldoses and ketoses is assumed to take place via 1,2‐enediol or 1,2‐enediolate intermediates, but such intermediates have never been isolated. The current work was undertaken in an attempt to detect the presence of the 1,2‐enediol structure of glycolaldehyde in alkaline medium, actually a 1,2‐enediolate, and to try to clarify the scarce data existing about both the formation of deprotonated enediol and the aldo‐enediolate equilibrium. The Raman spectra of neutral and basic solutions were recorded as a function of time for eleven days. Several bands associated with the presence of the enediolate were observed in alkaline medium. Glycolaldehyde exists as three different structures in aqueous solution at neutral pH, that is, hydrated aldehydes, aldehydes and dimers, with a respective ratio of approximately 4:0.25:1. Additionally, the formation ofZ‐enediolate forms takes place at basic pH, together with an increase in the concentration of aldehyde species, such as 2‐oxoethan‐1‐olate, and a decrease in the concentrations of the hydrated aldehyde and dimeric forms. The theoretical ratio of ≈1.5:1 for aldehyde:Z‐enediolate reproduces the experimental Raman spectrum in basic medium, with an additional contribution of the previously mentioned ratio between the hydrated aldehyde and dimeric forms. Finally, Raman spectroscopy allowed us to monitor the enolization of this carbohydrate model and conclude that aldo‐enediol tautomerism—formally aldo‐enediolate—happens when a suitable amount of basic species is added.
Controlling the Formation of Ionic‐Liquid‐based Aqueous Biphasic Systems by Changing the Hydrogen‐Bonding Ability of Polyethylene Glycol End Groups
Authors: Pereira Jorge F. B. , Kurnia Kiki A. , Freire Mara G. , Coutinho João A. P. , Rogers Robin D. 
Published: May 2015

AbstractThe formation of aqueous biphasic systems (ABS) when mixing aqueous solutions of polyethylene glycol (PEG) and an ionic liquid (IL) can be controlled by modifying the hydrogen‐bond‐donating/‐accepting ability of the polymer end groups. It is shown that the miscibility/immiscibility in these systems stems from both the solvation of the ether groups in the oxygen chain and the ability of the PEG terminal groups to preferably hydrogen bond with water or the anion of the salt. The removal of even one hydrogen bond in PEG can noticeably affect the phase behavior, especially in the region of the phase diagram in which all the ethylene oxide (EO) units of the polymeric chain are completely solvated. In this region, removing or weakening the hydrogen‐bond‐donating ability of PEG results in greater immiscibility, and thus, in a higher ability to form ABS, as a result of the much weaker interactions between the IL anion and the PEG end groups.
Magnetic Dextran Nanoparticles That Bear Hydrophilic Porphyrin Derivatives: Bimodal Agents for Potential Application in Photodynamic Therapy
Authors: Mbakidi Jean‐Pierre , Brégier Frédérique , Ouk Tan‐Sothea , Granet Robert , Alves Sandra , Rivière Eric , Chevreux Sylviane , Lemercier Gilles , Sol Vincent 
Published: May 2015

AbstractThis study reports the chemical synthesis of a class of dextran superparamagnetic nanoparticles that bear hydrophilic porphyrin units covalently grafted by a click chemistry reaction in aqueous solution. Magnetic nanoparticles are used in magnetic resonance imaging (MRI) and hyperthermia, and the grafting of hydrophilic photosensitizers (PS) leads to elaborate new multifunctional platforms for potential diagnostic and targeted photodynamic therapy (PDT). The therapeutic potential for PDT of these nanoparticles is evaluated in vitro against the HaCaT cell line. The results show that these new multicharged nanomagnets—in particular, those that bear cationic porphyrins—show a significant uptake and an interesting photocytotoxic activity toward HaCaT cells. The whole series of these synthesized PS are massively incorporated inside HaCat cells and associated with mitochondria.
Glycosaminoglycan‐Assisted Self‐Assembly of Nanostructured Conducting Poly(3,4‐ethylenedioxy thiophene) having Enhanced Osteogenic Bioactivity
Authors: Hao Jian , Piao Zhe , Yao Jin , Hao Zhao 
Published: May 2015

AbstractA sustainable nanofabrication approach using glycosaminoglycans (GAGs), the major organic extracellular matrix components, was employed to assist tunable self‐assembly of nanostructured poly(3,4‐ethylenedioxythiophene) (PEDOT) by template‐free electrochemical polymerization. An insight into GAG‐assisted self‐assembly of nanostructured PEDOT was proposed, which asserted that the EDOT monomers were self‐assembled by active groups of polysaccharide chains of GAGs, and subsequently PEDOT/GAGs chains self‐assembled to form nanostructured PEDOT. Its sustainable nature was supported through enhanced osteogenic bioactivity.
A Useful Route to Metal Complexes of Poorly Coordinating Sulfonamides
Authors: Fondo Matilde , Portela‐García Cristina , Baleeiro‐Tadiotto Arthur H. , García‐Deibe Ana M. , Sanmartín‐Matalobos Jesús 
Published: May 2015

AbstractWe report a synthetic approach towards metal complexes of the poorly coordinating sulfonamide 2‐tosylaminomethylaniline (HLTs) that exploits both the good donor capacity of imine N atoms and the hydrolysis of imine ligands mediated by d‐block metals. Zn2+, Cd2+ and Pd2+ ions appear to promote the efficient hydrolysis of a coordinated imine ligand (H2LSB) at room temperature, especially in a protic medium. The crystal structures of chiral R‐H2LSB and achiral trans‐Pd(LTs)2 allow us to compare some conformational changes of the sulfonamide residue after complexation.
Transparent Metal Network with Low Haze and High Figure of Merit applied to Front and Back Electrodes in Semitransparent ITO‐free Polymer Solar Cells
Authors: Hunger Christoph , Rao K. D. M. , Gupta Ritu , Singh Chetan R. , Kulkarni Giridhar U. , Thelakkat Mukundan 
Published: May 2015

AbstractIn the quest for indium‐tin oxide (ITO)‐free photovoltaics and for building integrated as well as automobile roof applications, novel transparent electrodes for both front and back electrodes are required. Here we report the fabrication and integration of submicrometer transparent silver (Ag) and gold (Au) metal network electrodes, which are invisible to the naked eye, in organic photovoltaic devices. We exploit the idea of using the spontaneous cracking of a polymer layer as template to prepare the metal network. The main challenge is to apply the cracked template approach on top of soluble organic layers and to lift off the template without damaging the photoactive layer. We demonstrate that Ag or Au back electrodes can be fabricated maintaining a transmittance of 80 % for the whole visible range. These electrodes exhibit ultralow haze of approximately 5 % and an excellent figure of merit value. Moreover, the ITO‐free semitransparent polymer solar cell incorporating the Ag/Ag network electrodes exhibits 57 % transmittance above 650 nm.
Modal response analysis of multi‐support structures using a random vibration approach
Authors: Heredia‐Zavoni Ernesto , Santa‐Cruz Sandra , Silva‐González Francisco L. 
Published: May 2015

SummaryA formulation is developed for modal response analysis of multi‐support structures using a random vibration approach. The spectral moments of the structural response are rigorously decomposed into contributions from spectral moments of uncoupled modal responses. An advantage of the proposed formulation is that the total dynamic response can be obtained on the basis of mode by mode uncoupled analyses. The contributions to the total response from modal responses under individual support ground motions and under cross‐correlated pairs of support ground motions can be recognized explicitly. The application and performance of the formulation is illustrated by means of an example using a well‐established coherency spectrum model and widely known power spectra models, such as white noise and Kanai–Tajimi. The first three spectral moments of displacement, shear, and bending moment responses are computed, showing that the formulation produces the same results as the exact solution. Copyright © 2015 John Wiley & Sons, Ltd.
Muddled Measures of Risks and Misremembered Reasons
Authors: Lantos John D. , Feudtner Chris 
Published: May 2015

AbstractA commentary on “Were There ‘Additional Foreseeable Risks’ in the SUPPORT Study?,” by Henry J. Silverman and Didier Dreyfuss; “SUPPORT: Risks, Harms, and Equipoise,” by Robert M. Nelson; “The Controversy over SUPPORT Continues and the Hyperbole Increases,” by Alan R. Fleischman; and “SUPPORT and Comparative Effectiveness Trials: What's at Stake?,” by Lois Shepherd, all in the January‐February 2015 issue.
Consultations across Languages
Authors: Bibler Trevor , Peña Adam , Bruce Courtenay R. 
Published: May 2015

AbstractLei, a twenty‐seven‐year‐old Mandarin speaker, visits the United States seeking curative treatments for his acute myeloid leukemia. His mother, Hua, has traveled with him. Neither she nor Lei speak English, and the hospital does not have an onsite professional Mandarin‐speaking interpreter. Using a professional interpreter over the phone, Lei's oncologist, Dr. Branson, attempts to initiate a face‐to‐face goals‐of‐care conversation with Hua as the surrogate decision‐maker. Dr. Branson explains that Lei has “only weeks to months to live” and recommends initiating comfort‐care‐only measures, but Hua says that she wants (and that Lei would want) continued aggressive measures. Hua says that her son might be a candidate for a phase I trial. Eventually, Dr. Branson brings in Dr. Chou, a Mandarin‐speaking resident to provide face‐to‐face interpretation. Hua insists that “there must be more standard therapies available” and says that she will wait until the trial begins. She begins crying, and the meeting disintegrates. Following this, Dr. Branson calls for an ethics consultation for “help in end‐of‐life communicating and reconciling discordance about prognostic information.”How should the ethicist use the institution's interpreter services?
Backward by Design: Building ELSI into a Stem Cell Science Curriculum
Authors: Scott Christopher Thomas 
Published: May 2015

AbstractTraditional methods of instruction can fail to produce enduring ways of learning, especially in rapidly changing disciplines in the life sciences. Educators and funding agencies are thus calling for new, integrated teaching approaches to address the life sciences. Hierarchical frameworks are being proposed as ways to tackle curricula with large numbers of concepts. Comparing lecture‐based and interactive formats by measuring performance with pre‐ and post‐tests indicated significantly higher learning gains and better conceptual understanding in the more interactive course. Other work has examined how the history of biology can be used to infuse relevance into the biology curriculum. In this paper, I describe a project at Stanford to create, implement, and evaluate an integrated curriculum in undergraduate stem cell education comprised of scientific, laboratory, and ELSI topics.
Must We Be Courageous?
Authors: Hamric Ann B. , Arras John D. , Mohrmann Margaret E. 
Published: May 2015

AbstractThe notion of virtue in general, and courage in particular, has had a hard time integrating itself into the everyday lexicon of bioethics. Following the lead of enlightenment moral philosophy, which concentrates on the theory of right action as opposed to the ancient Greeks' emphasis on the development of good character, bioethics, with some notable exceptions, has tended to relegate consideration of the virtues to the sidelines of moral argument. Recently, however, there have been calls for the necessity of “moral courage” in the context of clinical ethics. As nurses, physicians, and other health care professionals confront a variety of moral contexts in which the virtue of courage is invoked to "do the right thing," stand up for patients' rights, and uphold the ethical standards of their professions, they are increasingly reminded of their moral duty to exhibit courage in the face of institutional obstacles to the proper care of their patients. For example, a nurse's hesitation to approach a physician to request increased sedation for an agitated patient out of fear of retaliation is represented in one article as a lack of courage.In this paper we offer a critical assessment of such invocations of courage. While we find courage to be an indispensable virtue in some challenging contexts, in other settings we find invocations of courage to be both an unfortunate endorsement of an oppressive status quo that can divert attention from the real problems and an undesirable and potentially destructive strategy within health care institutions whose goal is medically excellent and morally good clinical practice. As we shall argue, a call to virtuousness is not always virtuous.
Incentives for Healthy Behavior
Authors: Rhodes Rosamond 
Published: May 2015

AbstractIn recent years, pay‐for‐performance initiatives have been employed to encourage desired behavior in various domains, including health. Employers use money to encourage employees to exercise; and hospitals, to encourage physicians to practice efficiently. Now, medical groups are considering the use of payments to encourage people to accept often‐avoided medical interventions, such as mammography or stool sampling. For example, a panel at the New York United Hospital Fund and the Greater New York Hospital Association Foundation's 2014 Annual Symposium on Health Care Services discussed how patient incentives could prevent illness, mitigate the impact of disease, save lives, and conserve medical resources and money.
Interferon Gamma, but not Calcitriol Improves the Osteopetrotic Phenotypes in ADO2 Mice
Authors: Alam Imranul , Gray Amie K. , Acton Dena , Gerard-O'Riley Rita L. , Reilly Austin M. , Econs Michael J. 
Published: May 2015

ABSTRACT

ADO2 is a heritable osteosclerotic disorder that usually results from heterozygous missense dominant negative mutations in the chloride channel 7 gene (CLCN7). ADO2 is characterized by a wide range of features and severity, including multiple fractures, impaired vision due to secondary bony overgrowth and/or the lack of the optical canal enlargement with growth, and osteonecrosis/osteomyelitis. The disease is presently incurable, although anecdotal evidence suggests that calcitriol and interferon gamma-1b (IFN-G) may have some beneficial effects. To identify the role of these drugs for the treatment of ADO2, we utilized a knock-in (G213R mutation in Clcn7) ADO2 mouse model that resembles the human disease. Six-week-old ADO2 heterozygous mice were administered vehicle (PBS) or calcitriol or IFN-G 5 times per week for 8 weeks. We determined bone phenotypes using DXA and μCT, and analyzed serum biochemistry and bone resorption markers. ADO2 mice treated with all doses of IFN-G significantly (p&lt;0.05) attenuated the increase of whole body aBMD and distal femur BV/TV gain in both male and female compared to the vehicle group. In contrast, mice treated with low and medium doses of calcitriol showed a trend of higher aBMD and BV/TV whereas high dose calcitriol significantly (p&lt;0.05) increased bone mass compared to the vehicle group. The calcium and phosphorus levels did not differ between vehicle and IFN-G or calcitriol treated mice; however, we detected significantly (p&lt;0.05) elevated levels of CTX/TRAP5b ratio in IFN-G treated mice. Our findings indicate that while IFN-G at all doses substantially improved the osteopetrotic phenotypes in ADO2 heterozygous mice, calcitriol treatment at any dose did not improve the phenotype and at high dose further increased bone mass. Thus, use of high dose calcitriol therapy in ADO2 patients merits serious reconsideration. Importantly, our data support the prospect of a clinical trial of IFN-G in ADO2 patients.