bluuebunny/crossref_metadata_2025 huggingface dataset:
Mini Liquid‐Liquid Extractor without Moving Parts Based on the Coanda Effect
Authors: Wang Jiao , Xu Cong
Published: February 2014

A mini liquid‐liquid extractor was designed based on a feedback fluidic oscillator. According to the Coanda effect, the designed oscillator with two feedback channels enables good mixing of the aqueous and organic phases. Co‐current liquid‐liquid extraction was performed in the mini extractor, and it was visually observed that the aqueous phase was dispersed into small droplets because of fluidic oscillation and vortex formation. The aqueous phase was more effectively dispersed at the stage near the outlet and with increasing flow. Several tests were performed for evaluating the extraction performance of the extractor using 30 % tributyl phosphate‐kerosene and 3 M HNO3 solutions as the organic and aqueous phases, respectively. The obtained extraction efficiency was close to the equilibrium efficiency, indicating that this extractor has the potential for liquid‐liquid extraction of hazardous liquids.
Graphene Defects as Active Catalytic Sites that are Superior to Platinum Catalysts in Electrochemical Nitrate Reduction
Authors: Kamiya Kazuhide , Hashimoto Kazuhito , Nakanishi Shuji
Published: February 2014

We report that graphene defects serve as active catalytic sites for the electrochemical nitrate reduction reaction (NRR). A defective graphene (without foreign elements) electrode exhibits an onset potential of 0.95 V versus Ag/AgCl for the electrochemical NRR in 5 MHNO3, which is 200 mV more positive than that exhibited by a platinum electrode. In addition, although the cathodic current of the platinum electrode during nitrate reduction decreases by 70 % upon the addition of 100 mMmethanol, the graphene electrode does not show any poisoning effects. The NRR on the graphene electrode shows autocatalytic behavior, including an induction period prior to the onset of the cathodic current. Moreover, the reduction reaction is accelerated by the addition of nitrite ions, and this indicates that nitrite is a key intermediate species in the autocatalytic mechanism. Density functional theory calculations reveal that a nitrosonium ion, which is an essential electrochemically active intermediate for the NRR, can strongly adsorb on the defect sites of a graphene sheet with electronic interaction, which indicates that the defect site can act as the active center for the NRR.
Wetting Behavior of Carbon Nanotubes
Authors: Dresel Alexander , Teipel Ulrich
Published: February 2014

Kohlenstoffnanoröhren (CNTs) sind Partikel mit grafitartig strukturierten Hüllen und nanoskaligen Durchmessern. Die Partikel/Fluid‐Interaktionen der CNTs sind wichtige Produkteigenschaften, da sie oft in niedrigviskosen Fluiden dispergiert werden. Die Charakterisierung der Benetzungseigenschaften von dispersen Systemen ist jedoch häufig problematisch, da direkte Methoden zur Kontaktwinkelbestimmung kaum angewendet werden können. Hier werden Untersuchungen zum Benetzungsverhalten nicht‐modifizierter und funktionalisierter, mehrwandiger CNT‐Materialien mit der Sorptionsmethode nach Washburn vorgestellt.
Central projections of intrinsically photosensitive retinal ganglion cells in the macaque monkey
Authors: Hannibal J. , Kankipati L. , Strang C.E. , Peterson B.B. , Dacey D. , Gamlin P.D.
Published: February 2014

Circadian rhythms generated by the suprachiasmatic nucleus (SCN) are entrained to the environmental light/dark cycle via intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin and the neuropeptide pituitary adenylate cyclase‐activating polypeptide (PACAP). The ipRGCs regulate other nonimage‐forming visual functions such as the pupillary light reflex, masking behavior, and light‐induced melatonin suppression. To evaluate whether PACAP‐immunoreactive retinal projections are useful as a marker for central projection of ipRGCs in the monkey brain, we characterized the occurrence of PACAP in melanopsin‐expressing ipRGCs and in the retinal target areas in the brain visualized by the anterograde tracer cholera toxin subunit B (CtB) in combination with PACAP staining. In the retina, PACAP and melanopsin were found to be costored in 99% of melanopsin‐expressing cells characterized as inner and outer stratifying melanopsin RGCs. Two macaque monkeys were anesthetized and received a unilateral intravitreal injection of CtB. Bilateral retinal projections containing colocalized CtB and PACAP immunostaining were identified in the SCN, the lateral geniculate complex including the pregeniculate nucleus, the pretectal olivary nucleus, the nucleus of the optic tract, the brachium of the superior colliculus, and the superior colliculus. In conclusion, PACAP‐immunoreactive projections with colocalized CtB represent retinal projections of ipRGCs in the macaque monkey, supporting previous retrograde tracer studies demonstrating that melanopsin‐containing retinal projections reach areas in the primate brain involved in both image‐ and nonimage‐forming visual processing. J. Comp. Neurol. 522:2231–2248, 2014. © 2014 Wiley Periodicals, Inc.
Metallaboranes from Metal Carbonyl Compounds and Their Utilization as Catalysts for Alkyne Cyclotrimerization
Authors: Anju V. P. , Barik Subrat Kumar , Mondal Bijnaneswar , Ramkumar V. , Ghosh Sundargopal
Published: February 2014

The photolysis of [M2(CO)10] (M=Re or Mn) with BH3⋅thf at room temperature yields arachno‐1 and 2, [(CO)8M2B2H6] (1: M=Re, 2: M=Mn). Both the compounds show a butterfly structure with seven skeletal electron pairs and 42 valence electrons. This result presents a new method for general access to low‐boron‐content metal–boron compounds without the cyclopentadienyl ligand at the metal centers. This new synthetic route is superior to the existing procedures because it avoids the use of [LiBH4] and metal polychlorides, for which the synthesis is very tedious. Compound 1 catalyzes the cyclotrimerization of a series of internal and terminal alkynes to yield mixtures of 1,3,5‐ and 1,2,4‐substituted benzenes. The reactivity of 1 with alkynes demonstrates for the first time that the introduction of the [B2H6] moiety into the [Re2(CO)10] framework significantly enhances the catalytic activity. Note that [Re2(CO)10] catalyzes the same set of alkynes under harsh conditions over a prolonged period of time. Quantum‐chemical calculations using DFT methods are applied to afford further insight into the electronic structure, stability, and bonding of 1 and 2. All the compounds are characterized by IR and 1H, 11B, and 13C NMR spectroscopy, and the geometry of 1 is established unambiguously through crystallographic analysis.
Revisiting Chronic Pain Patient Profiling: An Acceptance‐based Approach in an Online Sample
Authors: Payne‐Murphy Jessica C. , Beacham Abbie O.
Published: February 2014

Over 116 million Americans experience chronic pain, incurring an annual cost of $635bn in healthcare and lost work. Acceptance‐based therapies have gained increasing recognition for improving functional outcomes. In our online chronic pain sample, we predicted that (1) patients would cluster into low, medium and high groups of chronic pain acceptance and (2) positive affect, negative affect and perceived disability scores would differ overall by cluster, with the most positive outcomes found in the high cluster and the least found in the low cluster. Participants completed the Chronic Pain Acceptance Questionnaire, Positive and Negative Affect Scales and the Pain Disability Index. A k‐means cluster analysis was conducted using activity engagement (AE) and pain willingness (PW) totals from the Chronic Pain Acceptance Questionnaire. As predicted, cluster analysis specified three groups: low AE/low PW, high AE/high PW and medium AE/medium PW. Significant multivariate analysis of covariance results were obtained according to Wilks' λ (0.55), F(6,266) = 15.39, p < 0.01, and indicated differences in positive affect, negative affect and perceived disability within each cluster. Follow‐up analyses of covariance revealed mean differences in the predicted directions: the high‐high group showed the most positive affect and the least negative affect and perceived disability. Conversely, the low‐low group displayed the least positive affect (M = 20.28, SD = 7.86), the most negative affect (M = 28.05, SD = 9.33) and perceived disability (M = 49.57, SD = 9.46). The presence of these clusters introduces key questions about the possibility of creating tailored interventions based on cluster profiles. Copyright © 2014 John Wiley & Sons, Ltd.

Key Practitioner Message

Higher levels of Acceptance are associated with better functional and affective outcomes for chronic pain patients.

Lower Acceptance is associated with poorer functional and affective outcomes.

Tailoring interventions using Acceptance‐based profiling may improve chronic pain therapies.
Ageing is a risk factor in imatinib mesylate cardiotoxicity
Authors: Maharsy Wael , Aries Anne , Mansour Omar , Komati Hiba , Nemer Mona
Published: February 2014

Aims

Chemotherapy‐induced heart failure is increasingly recognized as a major clinical challenge. Cardiotoxicity of imatinib mesylate, a highly selective and effective anticancer drug belonging to the new class of tyrosine kinase inhibitors, is being reported in patients, some progressing to congestive heart failure. This represents an unanticipated challenge that could limit effective drug use. Understanding the mechanisms and risk factors of imatinib mesylate cardiotoxicity is crucial for prevention of cardiovascular complications in cancer patients.

Methods and results

We used genetically engineered mice and primary rat neonatal cardiomyocytes to analyse the action of imatinib on the heart. We found that treatment with imatinib (200 mg/kg/day for 5 weeks) leads to mitochondrial‐dependent myocyte loss and cardiac dysfunction, as confirmed by electron microscopy, RNA analysis, and echocardiography. Imatinib cardiotoxicity was more severe in older mice, in part due to an age‐dependent increase in oxidative stress. Mechanistically, depletion of the transcription factor GATA4 resulting in decreased levels of its prosurvival targets Bcl‐2 and Bcl‐XL was an underlying cause of imatinib toxicity. Consistent with this, GATA4 haploinsufficient mice were more susceptible to imatinib, and myocyte‐specific up‐regulation of GATA4 or Bcl‐2 protected against drug‐induced cardiotoxicity.

Conclusion

The results indicate that imatinib action on the heart targets cardiomyocytes and involves mitochondrial impairment and cell death that can be further aggravated by oxidative stress. This in turn offers a possible explanation for the current conflicting data regarding imatinib cardiotoxicity in cancer patients and suggests that cardiac monitoring of older patients receiving imatinib therapy may be especially warranted.
Preparation of Ag‐Modified (B,P)‐Codoped TiO2 Hollow Spheres with Enhanced Photocatalytic Activity
Authors: Yu Shuohan , Li Bin , Luo Yidan , Dong Lihui , Fan Minguang , Zhang Feiyue
Published: February 2014

A series of TiO2 hollow sphere catalysts with or without nonmetal (B,P) dopants and Ag‐modification were prepared through a sol–gel process with styrene–methyl methacrylate copolymer (PSMMA) microspheres as the template. The samples were characterized by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), laser Raman spectroscopy (LRS), and UV/Vis diffuse reflectance spectroscopy (UV/Vis DRS), and their photocatalytic activities were evaluated by degradation of methylene blue (MB). Both B and P dopants could narrow the band gap of the TiO2 catalyst, and the loaded Ag only played the role of photoelectron transmitter. The two effects of the nonmetal dopants and the loaded Ag improved the photocatalytic activity of the TiO2 hollow spheres. Moreover, the hollow sphere structure and oxygen vacancies were beneficial to photocatalysis. Among all the catalysts prepared, Ag‐modified (B,P)‐codoped TiO2 hollow spheres exhibited the highest photocatalytic activity.
Synthesis and Conformational Study of Model Peptides Containing N‐Substituted 3‐Aminoazetidine‐3‐carboxylic Acids
Authors: Žukauskaitė Asta , Moretto Alessandro , Peggion Cristina , De Zotti Marta , Šačkus Algirdas , Formaggio Fernando , De Kimpe Norbert , Mangelinckx Sven
Published: February 2014

Model peptides containing N‐substituted 3‐aminoazetidine‐3‐carboxylic acids have been synthesized to investigate the conformational features of these Cα‐tetrasubstituted amino acids. The target peptides were designed and prepared by classical synthetic methods in solution, exploiting the convenient N‐substituted 3‐azidoazetidine‐3‐carboxylic acids as precursors. The conformational preferences of the newly synthesized peptides were investigated in solution by IR and NMR spectroscopy. It was observed that the 3‐aminoazetidine‐3‐carboxylic acid moiety is likely a β‐turn inducer. In addition, an interesting main‐chain‐to‐side‐chain hydrogen bond that forms a six‐membered pseudo‐cycle was detected. It connects the nitrogen (acceptor) of the azetidine ring to the amide NH (donor) of the immediately following residue. This unexpected hydrogen bond increases the number of conformational options offered by N‐substituted 3‐aminoazetidine‐3‐carboxylic acids when designing foldamers with new and predictable 3D structures.
Synthesis of the Bioactive Benzochromenes Pulchrol and Pulchral, Metabolites of Bourreria pulchra
Authors: Killander Dan , Sterner Olov
Published: February 2014

The parasites Leshmania mexicana and Trypanosoma cruzi cause serious health problems, and few efficient treatments are available. Recently, the two benzochromenes pulchrol (1) and pulchral (2) were reported from the roots of Bourreria pulchra, and especially 1 but also 2 was found to be active towards the parasites. In this paper, we present a total synthesis of 1 and 2 to facilitate their biological evaluation. The synthesis is mild, short, and high yielding and suitable for a structure–activity relationship study.
Beyond need satisfaction: Empowering and accepting messages from third parties ineffectively restore trust and consequent reconciliation
Authors: Shnabel Nurit , Nadler Arie , Dovidio John F.
Published: February 2014

According to the Needs‐Based Model, reconciliation requires the restoration of victims' sense of power and perpetrators' moral image, which can be achieved through the exchange of empowering and accepting messages. In two role‐playing experiments, we extended the model by examining the role of message source, the other conflict party versus a neutral third party, in facilitating reconciliation. Focusing on transgressions between apartment roommates, Study 1 found that regardless of message source, empowering messages restored victims' sense of power, and accepting messages restored perpetrators' moral image. Yet, messages from the other conflict party restored victims' and perpetrators' trust in each other more effectively than messages from third parties. Multiple mediation analyses revealed that both need satisfaction (restoring victims' sense of power and perpetrators' moral image) and trust building were critical for reconciliation. Replicating these findings in a context of transgressions between workplace colleagues, Study 2 further revealed that messages from third parties restored perpetrators' moral image only in the eyes of the third party (but not in the eyes of the victim), leading to a negative indirect effect on perpetrators' reconciliation tendencies. Theoretical implications for the modification of the Needs‐Based Model and practical implications for the limits of third parties' interventions to promote interpersonal reconciliation are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Acute toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters, to 13 aquatic species as defined in the laboratory
Authors: Harper David D. , Farag Aïda M. , Skaar Don
Published: February 2014

Water produced during coal bed natural gas (CBNG) extraction in the Powder River Structural Basin of Wyoming and Montana (USA) may contain concentrations of sodium bicarbonate (NaHCO3) of more than 3000 mg/L. The authors evaluated the acute toxicity of NaHCO3, also expressed as bicarbonate (HCO3−), to 13 aquatic organisms. Of the 13 species tested, 7 had a median lethal concentration (LC50) less than 2000 mg/L NaHCO3, or 1300 mg/L HCO3−. The most sensitive species were Ceriodaphnia dubia, freshwater mussels (Lampsilis siliquoidea), pallid sturgeon (Scaphirhynchus albus), and shovelnose sturgeon (Scaphirhynchus platorynchus). The respective LC50s were 989 mg/L, 1120 mg/L, 1249 mg/L, and 1430 mg/L NaHCO3, or 699 mg/L, 844 mg/L, 831 mg/L, and 1038 mg/L HCO3−. Age affected the sensitivity of fathead minnows, even within life stage. Two days posthatch, fathead minnows were more sensitive to NaHCO3 and HCO3− compared with 4-d-old fish, even though fish up to 14 d old are commonly used for toxicity evaluations. The authors recommend that ion toxicity exposures be conducted with organisms less than 24 h posthatch to ensure that experiments document the most sensitive stage of development. The results of the present study, along with historical and current research regarding the toxicity of bicarbonate, may be useful to establish regulatory standards for HCO3−. Environ Toxicol Chem 2014;33:525–531. © 2014 SETAC. This article is a US Government work and is in the public domain in the USA.
The chronic toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters
Authors: Farag Aïda M. , Harper David D.
Published: February 2014

Sodium bicarbonate (NaHCO3) is the principal salt in coal bed natural gas produced water from the Powder River Structural Basin, Wyoming, USA, and concentrations of up to 3000 mg NaHCO3/L have been documented at some locations. No adequate studies have been performed to assess the chronic effects of NaHCO3 exposure. The present study was initiated to investigate the chronic toxicity and define sublethal effects at the individual organism level to explain the mechanisms of NaHCO3 toxicity. Three chronic experiments were completed with fathead minnows (Pimephales promelas), 1 with white suckers (Catostomus commersoni), 1 with Ceriodaphnia dubia, and 1 with a freshwater mussel, (Lampsilis siliquoidea). The data demonstrated that approximately 500 mg NaHCO3/L to 1000 mg NaHCO3/L affected all species of experimental aquatic animals in chronic exposure conditions. Freshwater mussels were the least sensitive to NaHCO3 exposure, with a 10-d inhibition concentration that affects 20% of the sample population (IC20) of 952 mg NaHCO3/L. The IC20 for C. dubia was the smallest, at 359 mg NaHCO3/L. A significant decrease in sodium–potassium adenosine triphosphatase (Na+/K+ ATPase) together with the lack of growth effects suggests that Na+/K+ ATPase activity was shut down before the onset of death. Several histological anomalies, including increased incidence of necrotic cells, suggested that fish were adversely affected as a result of exposure to >450 mg NaHCO3/L. Environ Toxicol Chem 2014;33:532–540. © 2014 SETAC. This article is a US Government work and is in the public domain in the USA.
Development of Ternary Cathodes Using MyCe1–x–yMnxO2–δ (M = La, Gd) as Catalysts for Oxygen Reduction Reactions
Authors: Liu L. , Zhao Z. , Zhang X. , Cui D. , Tu B. , Ou D. , Cheng M.
Published: February 2014

MyCe1–x–yMnxO2–δ (M = La, Gd) oxides have been investigated as oxygen reduction catalysts for LSM–YSZ based ternary cathodes. MyCe1–x–yMnxO2–δ samples are characterized by X‐ray diffraction (XRD), temperature programmed reduction of H2 (H2‐TPR), and temperature programmed desorption of O2 (O2‐TPD). The results show that the incorporation of M (M = La, Gd) ions increases the solution limit of Mn in the solid solutions, which increases the amount of oxygen vacancies and promotes oxygen adsorption and dissociation processes. The ternary cathodes show much higher electrochemical performance than LSM–YSZ binary cathode, and greatly accelerate oxygen dissociative adsorption and diffusion of oxygen species. The MyCe1–x–yMnxO2–δ catalysts exhibit greatly high activity for oxygen reduction at intermediate temperature. The ternary cathodes have high stability and high resistance to CO2 at 600 °C.
Raman Microspectroscopy as a Useful Tool for In Situ and Operando Studies of Water Transport in Perfluorosulfonic Membranes for PEMFCs
Authors: Deabate S. , Huguet P. , Morin A. , Gebel G. , Lanteri Y. , Peng Z. , Sutor A.‐K.
Published: February 2014

An operating PEMFC for commercial use must be able to adapt to variations in power demands and operating conditions while maintaining near optimal performance. Current research shows that one of the main issues affecting power output, stability, and longevity is the quantity and distribution of water in the system. The last are strongly affected by the sorption and transport properties of the polymer electrolyte. Thus, the need for a fundamental understanding of water transport in the PEMFC membrane‐electrode assembly has motivated, over the past few years, the development of new operando diagnostic tools sensitive to the membrane hydration. Among these, the most recent technique is based on confocal Raman microspectroscopy. This tutorial review is devoted to the illustration of the basis of this method, with a particular focus on the Raman signal processing needed to obtain reliable through‐plane water concentration profiles across PFSA membranes. Then, the potential of in situ and operando μ‐Raman is highlighted by reviewing the few studies reported to date, completed by the most recent results obtained by our group. Finally, advantages and drawbacks of operando Raman microspectroscopy are shortly discussed.
Coffee, alcohol and other beverages in relation to cirrhosis mortality: The Singapore Chinese Health Study
Authors: Goh George Boon-Bee , Chow Wan-Cheng , Wang Renwei , Yuan Jian-Min , Koh Woon-Puay
Published: February 2014

Limited experimental and epidemiologic data suggest that coffee may reduce hepatic damage in chronic liver disease. The association between consumption of coffee and other beverages and risk of cirrhosis mortality was evaluated in the Singapore Chinese Health Study. This is a prospective population-based cohort of 63,275 middle-aged and older Chinese subjects who provided data on diet, lifestyle, and medical histories through in-person interviews using a structured questionnaire at enrollment between 1993 and 1998. Mortality from cirrhosis in the cohort was ascertained through linkage analysis with nationwide death registry. After a mean follow-up of 14.7 years, 114 subjects died from cirrhosis; 33 of them from viral hepatitis B (29%), two from hepatitis C (2%), and 14 from alcohol-related cirrhosis (12%). Compared to nondrinkers, daily alcohol drinkers had a strong dose-dependent positive association between amount of alcohol and risk of cirrhosis mortality. Conversely, there was a strong dose-dependent inverse association between coffee intake and risk of nonviral hepatitis-related cirrhosis mortality (P for trend = 0.014). Compared to non-daily coffee drinkers, those who drank two or more cups per day had a 66% reduction in mortality risk (hazard ratio [HR] = 0.34, 95% confidence interval [CI] = 0.14-0.81). However, coffee intake was not associated with hepatitis B-related cirrhosis mortality. The inverse relationship between caffeine intake and nonviral hepatitis-related cirrhosis mortality became null after adjustment for coffee drinking. The consumption of black tea, green tea, fruit juices, or soft drinks was not associated with risk of cirrhosis death. Conclusion: This study demonstrates the protective effect of coffee on nonviral hepatitis-related cirrhosis mortality, and provides further impetus to evaluate coffee as a potential therapeutic agent in patients with cirrhosis. (Hepatology 2014;60:661–669)
Unresectable Solitary Hepatocellular Carcinoma Not Amenable to Radiofrequency Ablation: Multicenter Radiology-Pathology Correlation and Survival of Radiation Segmentectomy
Authors: Vouche Michael , Habib Ali , Ward Thomas J. , Kim Edward , Kulik Laura , Ganger Daniel , Mulcahy Mary , Baker Talia , Abecassis Michael , Sato Kent T. , Caicedo Juan-Carlos , Fryer Jonathan , Hickey Ryan , Hohlastos Elias , Lewandowski Robert J. , Salem Riad
Published: February 2014

Resection and radiofrequency ablation (RFA) are treatment options for hepatocellular carcinoma (HCC) <3 cm; there is interest in expanding the role of ablation to 3-5 cm. RFA is considered high-risk when the lesion is in close proximity to critical structures. Combining microcatheter technology and the localized emission properties of Y90, highly selective radioembolization is a possible alternative to RFA in such cases. We assessed the efficacy (response, radiology-pathology correlation, survival) of radiation segmentectomy in solitary HCC not amenable to RFA or resection. Patients with treatment-naïve, unresectable, solitary HCC ≤5 cm not amenable to RFA were included in this multicenter study. Administered dose, response rate, time-to-progression (modified Response Evaluation Criteria in Solid Tumors [mRECIST]), radiology-pathology correlation and long-term survival were assessed. In all, 102 patients were included in this study. mRECIST complete response (CR), partial response (PR), and stable disease (SD) were 47/99 (47%), 39/99 (39%), and 12/99 (12%), respectively. Median time-to-disease-progression was 33.1 months. In all, 33/102 (32%) patients were transplanted with a median (interquartile range [IQR]) time-to-transplantation of 6.3 months (3.6-9.7). Pathology revealed 100% and 50-99% necrosis in 17/33 (52%) and 16/33 (48%), respectively. Median overall survival was 53.4 months. Univariate analysis demonstrated a survival benefit for Eastern Cooperative Oncology Group (ECOG) 0 patients. In the multivariate model, age <65, ECOG 0, and Child-Pugh A were characteristics associated with longer survival.

Conclusion :

Radiation segmentectomy is an effective technique with a favorable risk profile and radiology-pathology outcomes for solitary HCC ≤5 cm. This approach may allow for treatment of HCC in difficult locations. Since RFA and resection are not options given tumor location, there appears to be a strong rationale for this technique as second choice. (Hepatology 2014;60:192–201)
Impact of manganese on primary hippocampal neurons from rodents
Authors: Daoust Alexia , Saoudi Yasmina , Brocard Jacques , Collomb Nora , Batandier Cécile , Bisbal Mariano , Salomé Murielle , Andrieux Annie , Bohic Sylvain , Barbier Emmanuel L.
Published: February 2014

Manganese‐enhanced magnetic resonance imaging (MEMRI) is a powerful tool for in vivo tract tracing or functional imaging of the central nervous system. However Mn2+ may be toxic at high levels. In this study, we addressed the impact of Mn2+ on mouse hippocampal neurons (HN) and neuron‐like N2a cells in culture, using several approaches. Both HN and N2a cells not exposed to exogenous MnCl2 were shown by synchrotron X‐ray fluorescence to contain 5 mg/g Mn. Concentrations of Mn2+ leading to 50% lethality (LC50) after 24 h of incubation were much higher for N2a cells (863 mM) than for HN (90 mM). The distribution of Mn2+ in both cell types exposed to Mn2+ concentrations below LC50 was perinuclear whereas that in cells exposed to concentrations above LC50 was more diffuse, suggesting an overloading of cell storage/detoxification capacity. In addition, Mn2+ had a cell‐type and dose‐dependent impact on the total amount of intracellular P, Ca, Fe and Zn measured by synchrotron X‐ray fluorescence. For HN neurons, immunofluorescence studies revealed that concentrations of Mn2+ below LC50 shortened neuritic length and decreased mitochondria velocity after 24 h of incubation. Similar concentrations of Mn2+ also facilitated the opening of the mitochondrial permeability transition pore in isolated mitochondria from rat brains. The sensitivity of primary HN to Mn2+ demonstrated here supports their use as a relevant model to study Mn2+‐induced neurotoxicity. © 2014 Wiley Periodicals, Inc.
Corrosion resistance improvement for 316L stainless steel coronary artery stents by trimethylsilane plasma nanocoatings
Authors: Eric Jones John , Chen Meng , Yu Qingsong
Published: February 2014

To improve their corrosion resistance and thus long‐term biocompatibility, 316L stainless steel coronary artery stents were coated with trimethylsilane (TMS) plasma coatings of 20–25 nm in thickness. Both direct current (DC) and radio‐frequency (RF) glow discharges were utilized for TMS plasma coatings and additional NH3/O2 plasma treatment to tailor the surface properties. X‐ray photoelectron spectroscopy (XPS) was used to characterize the coating surface chemistry. It was found that both DC and RF TMS plasma coatings had Si‐ and C‐rich composition, and the O‐ and N‐contents on the surfaces were substantially increased after NH3/O2 plasma treatment. Surface contact angle measurements showed that DC TMS plasma nanocoating with NH3/O2 plasma treatment generated very hydrophilic surface. The corrosion resistance of TMS plasma coated stents was evaluated through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization demonstrated that the TMS plasma coated stents imparted higher corrosion potential and pitting potential, as well as lower corrosion current densities as compared with uncoated controls. The surface morphology of stents before and after potentiodynamic polarization testing was analyzed with scanning electron microscopy, which indicated less corrosion on coated stents than uncoated controls. It was also noted that, from EIS data, the hydrophobic TMS plasma nanocoatings showed stable impedance modulus at 0.1 Hz after 21 day immersion in an electrolyte solution. These results suggest improved corrosion resistance of the 316L stainless steel stents by TMS plasma nanocoatings and great promise in reducing and blocking metallic ions releasing into the bloodstream. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1363–1374, 2014.
Immunological response to bolus versus multiple injections of hylan G‐F 20 (Synvisc®) in a murine biocompatibility model
Authors: Markel David C. , Jackson Nancy M. , Esquivel Amanda O. , Ren Weiping , Flynn Jeffrey C.
Published: February 2014

Local tissue reactivity to intra‐articular injections of hyaluronic acid hylan G‐F 20 (Synvisc®) has been described. We used a murine biocompatibility model to study the inflammatory response to Synvisc® after a single bolus injection versus the traditional three shot series of injections. Air pouches were established subcutaneously in BALB/c mice, which were injected with phosphate‐buffered saline (PBS), 5 mg ultra‐high molecular weight polyethylene particles (to simulate synthetic joint wear debris, positive control), 0.5 mL Synvisc® (one injection/week for three weeks, harvested 14 days after last injection), or 1.5 mL Synvisc® bolus (harvested either 14 or 28 days after last injection). Inflammatory gene expression and inflammation of air pouch tissue, and serum antibody titers to Synvisc® were determined. Inflammation was observed with all Synvisc® treatments relative to PBS (p < 0.01). However, the three injection series of Synvisc® resulted in significantly (p < 0.05) greater tumor necrosis factor‐alpha gene expression compared to both PBS and bolus single shot Synvisc® harvested after 14 or 28 days. While all Synvisc® treatments resulted in serum antibodies to Synvisc® (p < 0.02 compared to PBS control group), mice that received three injections of Synvisc® had higher levels than mice receiving a single injection (p < 0.01). These results demonstrate that a single bolus injection of Synvisc® led to less inflammation and a lower antibody response when compared to the three‐shot series of injections, supporting the current change in treatment from multiple injections to a single injection of Synvisc®. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1375–1380, 2014.
Accessing the applicability of polarized protein‐specific charge in linear interaction energy analysis
Authors: Jia Xiangyu , Zeng Juan , Zhang John Z. H. , Mei Ye
Published: February 2014

The reliability of the linear interaction energy (LIE) depends on the atomic charge model used to delineate the Coulomb interaction between the ligand and its environment. In this work, the polarized protein‐specific charge (PPC) implementing a recently proposed fitting scheme has been examined in the LIE calculations of the binding affinities for avidin and β‐secretase binding complexes. This charge fitting scheme, termed delta restrained electrostatic potential, bypasses the prevalent numerical difficulty of rank deficiency in electrostatic‐potential‐based charge fitting methods via a dual‐step fitting strategy. A remarkable consistency between the predicted binding affinities and the experimental measurement has been observed. This work serves as a direct evidence of PPC's applicability in rational drug design. © 2014 Wiley Periodicals, Inc.
Facile synthesis of ZnO nanorods grown on graphene sheets and its enhanced photocatalytic efficiency
Authors: Lv Rong , Wang Xitao , Lv Wei , Xu Yanli , Ge Yonghui , He Hui , Li Geng , Wu Xiaoqian , Li Xu , Li Qiang
Published: February 2014

BACKGROUND

Recent advancements in nanoscale materials have focused on well‐designed nanocomposites that are highly oriented and organized. Three‐dimensional arrays consisting of one‐dimensional ZnO nanorods grown on reduced graphene oxide (RGO) sheets should be an efficient photocatalyst for photocatalytic hydrogen production from glycerol solution due to the increased adsorptivity of the reactant, extended light absorption range, and especially efficient charge transportation and separation.

RESULTS

It was found that the calcination temperature of the ZnO seed layer had a significant influence on the morphology, surface structure, optical and electronic properties of ZnO/RGO nanocomposites. When the calcination temperature of the ZnO seed layer was 400 °C, ZnO nanorods grown on graphene sheets with C–O–Zn linkages can be achieved. This sample exhibited the highest photocatalytic H2 production rate.

CONCLUSION

The results of this study show that superior photocatalytic performance originates from the higher transfer rate of photo‐generated electrons from ZnO to RGO, and repressed recombination of the photoinduced hole–electron pairs of ZnO, which is closely related with the chemical interaction between ZnO and RGO and the concentration of Zn–O–C bonds. Moreover, the morphology of ZnO nanorods favors the directional transfer of electrons in ZnO. © 2014 Society of Chemical Industry
The ventral nerve cord in cephalocarida (Crustacea): New insights into the ground pattern of tetraconata
Authors: Stegner Martin E.J. , Brenneis Georg , Richter Stefan
Published: February 2014

Cover illustration. The horseshoe shrimp Hutchinsoniella macracantha belongs to the ancient crustacean taxon of Cephalocarida. Its external morphology and neuroanatomy exhibit several plesiomorphic structures and patterns dating back to the ancestor of all Tetraconata. In this issue of the Journal of Morphology, Stegner and coauthors (pp. 269–294) studied the ventral nerve cord of adult Hutchinsoniella macracantha in detail, combining immunolabeling (tubulin, serotonin, RFamide, histamine) and nuclear stains with confocal laser microscopy, complemented by 3D‐reconstructions based on serial semithin sections. The cover image shows lateral 3D‐overviews of the cuticle (white in top row, semitransparent in second row), the gut (green, third row), and the ventral nerve cord (neurites and neuropil in yellow, somata in dark grey, bottom row). Different from most other crustaceans, also the limb‐less abdomen in Cephalocarida comprises segmental ganglia.
Postoperative MRI of the shoulder
Authors: Beltran Luis S. , Bencardino Jenny T. , Steinbach Lynne S.
Published: February 2014

Magnetic resonance imaging (MRI) evaluation of the postoperative shoulder presents technical and diagnostic challenges related to imaging artifacts from hardware and micrometallic shavings, postsurgical scarring, and morphological alterations. Improved visualization of postoperative shoulder anatomy and pathology can be obtained with the use of metal artifact reduction techniques as well as MR arthrography. In this article we review the MR techniques that are designed to address these technical and diagnostic challenges, and we discuss the definitions and indications, normal MRI appearance, and complications of routine surgical procedures for treatment of injuries to the rotator cuff, labral ligamentous complex, and biceps tendon. J. Magn. Reson. Imaging 2014;40:1280–1297. © 2014 Wiley Periodicals, Inc.
Interpreting Tourism at Olympic Sites: A Cross‐cultural Analysis of the Beijing Olympic Green
Authors: Brown Graham , Huang Songshan (Sam)
Published: February 2014

An examination is made of tourism at Olympic sites by reflective analyses of experiences gained at the Beijing Olympic Green. An account of experiences at the site, accompanied by photographs, was analysed through different cultural lenses to reveal distinctive characteristics of the setting and divergent interpretations of tourist behaviour. The findings enhance understanding of the role of Olympic sites as tourist attractions and the importance of photography as part of the tourist experience and as a research tool. The study demonstrates the utility of post‐experience interpretations when informed by relevant theoretical frameworks. Copyright © 2014 John Wiley & Sons, Ltd.
Survival and population growth of a free‐ranging elk population with a long history of exposure to chronic wasting disease
Authors: Monello Ryan J. , Powers Jenny G. , Hobbs N. Thompson , Spraker Terry R. , Watry Mary Kay , Wild Margaret A.
Published: February 2014

Investigations of chronic wasting disease (CWD), a fatal, contagious prion disease of free‐ranging cervids, suggest the disease can cause long‐term population declines in deer (Odocoileus spp.). However, the implications of CWD for elk (Cervus elaphus nelsoni) populations are less certain. During 2008–2010, we used rectal biopsies and telemetry to observe disease transmission and survival in adult female elk from a high‐density herd in Rocky Mountain National Park (RMNP) that had been infected by CWD for over 25 years. We studied a cohort of 123 adult female elk that were determined to be free of CWD by rectal biopsy in 2008. Annual incidence of CWD was 0.08 [95% Bayesian credible interval (BCI) = 0.05, 0.12]. Annual survival probabilities of the cohort excluding harvest declined from 0.97 in 2008 (BCI = 0.93, 0.99) to 0.85 in 2010 (BCI = 0.75, 0.93). Declines in survival were attributed almost entirely to CWD; the proportion of radiocollared elk that died of CWD increased from 0.02 in 2008 (BCI = 0.00, 0.05) to 0.11 in 2010 (BCI = 0.04, 0.21). We attributed the increase to the time lag required for development of new CWD cases. We used survival rates of susceptible and infected elk to develop a projection matrix for a discrete time, female only model that estimated the intrinsic population growth rate (λ) of this elk herd to be 1.00 (BCI = 0.93, 1.05) using the prevalence of CWD (12.9%) and calf:cow ratios (24:100) observed during this study. Population declines were predicted to occur when prevalence of CWD exceeded 13% (BCI = 0, 35). However, this estimate was contingent on calf:cow ratios and harvest. Greater recruitment will offset some of the effects of CWD, whereas the inclusion of female harvest, which was excluded from this study, would likely result in lower λ values than those observed in this study. We conclude that CWD can exceed natural rates of mortality, reduce survival of adult females, and decrease population growth of elk herds. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Deposit chemistry and initial corrosion during biomass combustion – The influence of excess O2 and sulphate injection
Authors: Viklund P. , Kassman H. , Åmand L.‐E.
Published: February 2014

Corrosion of superheater tubes is a serious problem during combustion of fuels with a high content of chlorine, such as waste and certain biomasses. The alkali chlorides are released to the flue gas and may condense on the heat exchanger tubes forming corrosive, chloride‐rich deposits. In this work the effect of ammonium sulphate ((NH4)2SO4) injection on gaseous alkali chlorides, deposit chemistry and initial corrosion attack of superheater tubes during biomass combustion have been investigated. The investigation was carried out at three different sulphate injection rates (reference, low and high) and at three air excess ratios (λ = 1.1, 1.2 and 1.4). Short‐term exposures of Sanicro 28 specimens, using temperature controlled probes, were used for deposit collection and to study the initial corrosion attack.

The results showed reduced concentrations of potassium chloride in the flue gas when injecting ammonium sulphate and in particular in combination with high air excess ratios. A decrease of chlorine was also observed in the deposit, but the concentrations did not always correlate to the flue gas measurements. In particular, it was evident that a subsequent sulphation occurred on the tube surface at low air excess ratios. Metallography revealed that sulphation reactions on the tube surface, rather than in the flue gas, had a detrimental effect on the initial corrosion attack. As a consequence, the corrosion attack correlated more clearly to the KCl(g) concentration in the flue gas than the chlorine content in the deposit.
Corrosion behaviour of stainless steel–titanium alloy linear friction welded joints: Galvanic coupling
Authors: Astarita A. , Curioni M. , Squillace A. , Zhou X. , Bellucci F. , Thompson G. E. , Beamish K. A.
Published: February 2014

Linear friction welding may be used to join titanium alloys to stainless steel for a variety of applications. After welding, a crevice is often observed close to the edges and, in aqueous wet environments, a galvanic couple is formed between the two materials. If corrosion resistance is a requirement, the combined presence of a crevice and a galvanic couple is a concern. In this study, the behaviour of galvanically coupled titanium alloy and stainless steel has been investigated, both for planar electrodes and under simulated crevice conditions. In both cases, it was found that a significant driving force between the two materials develops over time to progress corrosion on the stainless steel, but the high specific impedance of the titanium surface limits the current flow. Consequently, it is concluded that galvanic coupling between titanium and stainless steel is only of concern if the area of the titanium largely exceeds the area of the steel, and only under complete immersion conditions in a sufficiently conductive electrolyte.
Effect of Al2O3–Ti composite coating on corrosion behavior of TiAl6V4 alloy
Authors: Mahmoudi M. , Maleki‐Ghaleh H. , Kavanlouei M. , Aghaie E.
Published: February 2014

In the present study, Al2O3–Ti coated on TiAl6V4 alloy used electrophoretic deposition (EPD) method to improve the corrosion resistance and biocompatibility. Electrophoretic deposition process was performed at 90 s and constant voltage of 50 V in various compositions of 30, 50, and 70 wt% of Al2O3. After deposition, samples were dried at room temperature and then the coated samples were sintered at 1050 °C for 4 h. Scanning electron microscope and X‐ray diffraction analysis were employed to investigate the microstructure and phase analysis of the coatings. Moreover, the behavior of the coated samples was investigated by using electrochemical impedance spectroscopy and polarization tests. The results show that the Al2O3–Ti composite coatings sintered at an inert gas (argon) atmosphere reveals a uniform, dense coating, which includes the composition of Ti and Al oxide phases. Evaluation of electrochemical test in simulated body fluid represents the improvement of the corrosion resistance of the coated sample in comparison to uncoated TiAl6V4 sample. Moreover, the 50 wt% of Al2O3 composite coated sample revealed the highest corrosion resistance among the coated samples due to a uniform and more stable phase composition in comparison to other coated samples.
A Miscible and Adaptive Poly(methyl acrylate)/Polystyrene Blend Formed by Multiple‐Responsive Host–Guest Interactions
Authors: Ji Xiaofan , Chen Jianzhuang , Xue Min
Published: February 2014

Polymer blends play a significant role in polymer science due to their new and unique properties compared with the individual polymer components. However, most polymer blends are immiscible and not adaptive to environmental stimuli. Here, an enhancement of the compatibility of an immiscible poly(methy acrylate)/polystyrene blend based on multiple‐responsive benzo‐21‐crown‐7/dialkylammoniumsalt host–guest interactions is made. Owing to the multi‐responsiveness and reversibility of benzo‐21‐crown‐7/dialkylammoniumsalt host–guest interactions, the polymer blend recovers its compatibility after being damaged by environmental factors, indicating its adaptiveness.

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An Arm‐First Approach to Cleavable Mikto‐Arm Star Polymers by RAFT Polymerization
Authors: Wei Xiaohu , Moad Graeme , Muir Benjamin W. , Rizzardo Ezio , Rosselgong Julien , Yang Wantai , Thang San H.
Published: February 2014

Redox‐cleavable mikto‐arm star polymers are prepared by an “arm‐first” approach involving copolymerization of a dimethacrylate mediated by a mixture of macroRAFT agents. Thus, RAFT copolymerization of the monomers BMA, DMAEMA, and OEGMA, with the disulfide dimethacrylate cross‐linker (DSDMA), bis(2‐methacryloyl)oxyethyl disulfide, mediated by a 1:1:1 mixture of three macroRAFT agents with markedly different properties [hydrophilic, poly[oligo(ethylene glycol) methacrylate]—P(OEGMA)8–9; cationizable, poly[2‐(dimethylamino)ethyl methacrylate]—P(DMAEMA); hydrophobic, poly(n‐butyl methacrylate)—P(BMA)] provides low dispersity mikto‐arm star polymers. Good control (Đ < 1.3) is observed for the target P(DMAEMA)/P(OEGMA)/P(BMA) (3:3:1) mikto‐arm star, a double hydrophilic P(DMAEMA)/P(OEGMA) (3:3) mikto‐arm star and a hydrophobic P(BMA) homo‐arm star. However, Đ for the target mikto‐arm stars increases with an increase in either the ratio [DSDMA]:[total macroRAFT] or the fraction of hydrophobic P(BMA) macroRAFT agent. The quaternized mikto‐arm star in dilute aqueous solution shows a monomodal particle size distribution and an average size of ≈145 nm.

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Investigation of impact characteristics of tempered vehicle and vessel glasses
Authors: Gürsel K. T. , Özgül F.
Published: February 2014

Glass is widely used at various engineering applications, especially in vehicle and vessel industry due to the reasons such as transparency, hardness at the room temperature and its strength against impact. One of the processes to be applied to glass is tempering. This process is applied to glass with the aim of providing 2–5 times more impact resistance. Additionally, if tempered glass is fractured it goes to pieces without sharp edges. These pieces are too small to injure people around them. Thus, nowadays side and rear glasses of vehicles and vessels are tempered glasses.

In this study, tempered and untempered vehicle glasses were tested by using Instron Dynatup 9250 HV Impact Apparatus in the Mechanical Engineering Department of Pamukkale University, impact was applied to 145 samples with an average of 5.3 (771) times and their impact strength values were determined.

In the first stage of this study, magnitudes of impact energies causing damages at tempered and untempered vehicle and vessel glasses with a thickness of 4 mm and 6 mm at +20 °C, were determined. In the second stage, impact experiments were performed at the environment temperatures of –20 °C and +40 °C apart from the room temperature, because the glasses to be produced will be used in different climate zones.

In this way, a useful source of knowledge, especially for developing tempered vehicle and vessel glasses, will be constituted by determining the impact strength characteristics of these glasses.