bluuebunny/crossref_metadata_2025 huggingface dataset:
Hierarchical Mesoporous SnO2 Nanosheets on Carbon Cloth: A Robust and Flexible Electrocatalyst for CO2 Reduction with High Efficiency and Selectivity
Authors: Li Fengwang , Chen Lu , Knowles Gregory P. , MacFarlane Douglas R. , Zhang Jie
Published: December 2016

Electrochemical reduction of CO2 into liquid fuels is a promising approach to achieve a carbon‐neutral energy cycle. However, conventional electrocatalysts usually suffer from low energy efficiency and poor selectivity and stability. A 3D hierarchical structure composed of mesoporous SnO2 nanosheets on carbon cloth is proposed to efficiently and selectively electroreduce CO2 to formate in aqueous media. The electrode is fabricated by a facile combination of hydrothermal reaction and calcination. It exhibits an unprecedented partial current density of about 45 mA cm−2 at a moderate overpotential (0.88 V) with high faradaic efficiency (87±2 %), which is even larger than most gas diffusion electrodes. Additionally, the electrode also demonstrates flexibility and long‐term stability. The superior performance is attributed to the robust and highly porous hierarchical structure, which provides a large surface area and facilitates charge and mass transfer.
Hydrothermal Carbon Enriched with Oxygenated Groups from Biomass Glucose as an Efficient Carbocatalyst
Authors: Wen Guodong , Wang Bolun , Wang Congxin , Wang Jia , Tian Zhijian , Schlögl Robert , Su Dang Sheng
Published: December 2016

Metal‐free carbocatalysts enriched with specific oxygenated groups with different morphology and size were synthesized from glucose by hydrothermal carbonization, in which cheap and widely available biomass could be converted into functionalized carbon using an environmentally benign process. The hydroxy‐ and carbonyl‐enriched hydrothermal carbon (HTC) could be used in nitrobenzene reduction, and higher conversion was obtained on the sphere morphology with smaller size. In the Beckmann rearrangement of cyclohexanone oxime, carboxyl‐enriched HTC exhibited superior performance compared with conventional solid acid (such as HY and HZSM‐5), on which the strong acid sites and weak Lewis acid sites lead to high selectivity for the side product. Although the intrinsic acidity of carbon is weak, the carboxyl‐enriched carbon was used in weak Brønsted acid‐catalyzed reactions, such as the Beckmann rearrangement.
Markovnikov‐Selective Radical Addition of S‐Nucleophiles to Terminal Alkynes through a Photoredox Process
Authors: Wang Huamin , Lu Qingquan , Chiang Chien‐Wei , Luo Yi , Zhou Jiufu , Wang Guangyu , Lei Aiwen
Published: December 2016

Direct radical additions to terminal alkynes have been widely employed in organic synthesis, providing credible access to the anti‐Markovnikov products. Because of the Kharasch effect, regioselective control for the formation of Markovnikov products still remains a great challenge. Herein, we develop a transition‐metal‐free, visible light‐mediated radical addition of S‐nucleophiles to terminal alkynes, furnishing a wide array of α‐substituted vinyl sulfones with exclusive Markovnikov regioselectivity. Mechanistic investigations demonstrated that radical/radical cross‐coupling might be the key step in this transformation. This radical Markovnikov addition protocol also provides an opportunity to facilitate the synthesis of other valuable α‐substituted vinyl compounds.
A Hydrogen‐Bonded Cyanide‐Bridged [Co2Fe2] Square Complex Exhibiting a Three‐Step Spin Transition
Authors: Nihei Masayuki , Yanai Yuta , Hsu I.‐Jui , Sekine Yoshihiro , Oshio Hiroki
Published: December 2016

Co‐crystallization of a cyanide‐bridged tetranuclear complex [Co2Fe2] with 4‐cyanophenol (CP) gave a hydrogen bonding donor–acceptor system, [Co2Fe2(bpy*)4(CN)6(tp*)2](PF6)2⋅2 CP⋅8 BN (1). 1 exhibited a three‐step phase transition between HT, IM1, IM2, and LT phases upon temperature variation. Variable temperature magnetic measurements and structural analyses revealed that the three‐step spin transition is caused by electron‐transfer‐coupled spin transitions (ETCSTs) accompanied with alteration of the hydrogen bonding interactions.
Measuring medical students' motivation to learning anatomy by cadaveric dissection
Authors: Abdel Meguid Eiman M. , Khalil Mohammed K.
Published: December 2016

Motivation and learning are inter‐related. It is well known that motivating learners is clearly a complex endeavor, which can be influenced by the educational program and the learning environment. Limited research has been conducted to examine students' motivation as a method to assess the effectiveness of dissection in medical education. This study aimed to assess and analyze students' motivation following their dissection experience. A 29‐item survey was developed based on the Attention, Relevance, Confidence, and Satisfaction model of motivation. Descriptive statistics were undertaken to describe students' motivation to the dissection experience. T‐test and ANOVA were used to compare differences in motivational scores between gender and educational characteristics of students. Dissection activities appear to promote students' motivation. Gender difference was statistically significant as males were more motivated by the dissection experience than females. Comparison between students with different knowledge of anatomy was also significantly different. The study is an important step in the motivational design to improve students' motivation to learn. The outcome of this study provides guidance to the selection of specific strategies to increase motivation by generating motivational strategies/tactics to facilitate learning. Anat Sci Educ 10: 363–371. © 2016 American Association of Anatomists.
Improving Robustness Filter Bandwidth in Repetitive Control by Considering Model Mismatch
Authors: Eielsen Arnfinn A. , Teo Yik R. , Fleming Andrew J.
Published: December 2016

Repetitive control (RC) is used to track and reject periodic signals by including a model of a periodic signal in the feedback path. The performance of RC can be improved by including an inverse plant response filter, but due to modeling uncertainty at high frequencies, a low‐pass robustness filter is also required to limit the bandwidth of the signal model and ensure stability. The design of robustness filters is presently ad‐hoc, which may result in excessively conservative performance. This article proposes a new automatic method for designing the robustness filter based on convex optimization and an uncertainty model. Experimental results on a nanopositioning system demonstrate that the proposed method outperforms the traditional brick‐wall filter approach.
Capacity investment model for airport facilities under demand uncertainty
Authors: Sun Yanshuo , Schonfeld Paul M.
Published: December 2016

This paper addresses strategic airport facility planning under demand uncertainty. Existing studies are improved by (1) allowing capacity contraction and (2) adopting more flexible delay functions. A mixed‐integer nonlinear program, which incorporates scale economies in construction, time value of money, nonlinear congestion effect, and other factors, is proposed for optimizing the capacity expansion/contraction decisions over time for multiple airport components. The stochastic problem is converted into its deterministic equivalent because the number of demand scenarios considered is finite. A discrete approximation technique is used to remove the nonlinearities. Numerical studies are presented to demonstrate the capability of the proposed model and the computational efficiency of the solution method. The “Flaw of Averages” due to faulty decisions based on the average future condition is illustrated, and trade‐offs among various costs are discussed in the numerical analyses. Copyright © 2016 John Wiley & Sons, Ltd.
Physiologically based pharmacokinetic modeling revealed minimal codeine intestinal metabolism in first‐pass removal in rats
Authors: Noh Keumhan , Chen Shu , Yang Qi J. , Pang K. Sandy
Published: December 2016

The physiologically based model with segregated flow to the intestine (SFM‐PBPK; partial, lower flow to enterocyte region vs. greater flow to serosal region) was found to describe the first‐pass glucuronidation of morphine (M) to morphine‐3β‐glucuronide (MG) in rats after intraduodenal (i.d.) and intravenous (i.v.) administration better than the traditional model (TM), for which a single intestinal flow perfused the whole of the intestinal tissue. The segregated flow model (SFM) described a disproportionately greater extent of intestinal morphine glucuronidation for i.d. vs. i.v. administration. The present study applied the same PBPK modeling approaches to examine the contributions of the intestine and liver on the first‐pass metabolism of the precursor, codeine (C, 3‐methylmorphine) in the rat. Unexpectedly, the profiles of codeine, morphine and morphine‐3β‐glucuronide in whole blood, bile and urine, assayed by LCMS, were equally well described by both the TM‐PBPK and SFM‐PBPK. The fitted parameters for the models were similar, and the net formation intrinsic clearance of morphine (from codeine) for the liver was much higher, being 9‐ to 13‐fold that of the intestine. Simulations, based on the absence of intestinal formation of morphine, correlated well with observations. The lack of discrimination of SFM and TM with the codeine data did not invalidate the SFM‐PBPK model but rather suggests that the liver is the only major organ for codeine metabolism. Because of little or no contribution by the intestine to the metabolism of codeine, both the TM‐ and SFM‐PBPK models are equally consistent with the data. Copyright © 2016 John Wiley & Sons, Ltd.
Role of ABC transporters in trans‐epithelial transport of vitamin K antagonists
Authors: Espana Bernadette , Couturier Solange , Prouillac Caroline
Published: December 2016

Vitamin K antagonists (VKAs) remain the oral anticoagulant of choice in venous thromboembolic disease. These drugs are characterized by a large inter‐individual variability requiring frequent dose tailoring. Genetic polymorphisms for cytochrome CYP2C9 and VKORC1 explain some of the variability, especially in warfarin and acenocoumarol responses. The aim of this study was to assess, in cell models, the role of ABC transporters in the intestinal transfer of the main coumarin derivatives (warfarin, acenocoumarol) and indanedione derivatives (phenindione, fluindione). The results show a basal to apical polarized transport for fluindione, phenindione and acenocoumarol only. Experimental studies using specific inhibitors of transport protein demonstrate the implication of MRPs and BCRP proteins and to a lesser extent P‐gp. Warfarin and acenocoumarol seem to be poor inhibitors of MRPs protein, whereas fluindione and phenindione have a slight or no effect. The regulation of the expression of ABC transporters by exposure to VKAs was also investigated in Caco‐2 cells. The expression of mRNA P‐gp, MRP1, MRP2 and BCRP was weakly or not modified after 24 h of VKAs exposure. In conclusion, the intestinal transfer of indanedione derivatives and acenocoumarol could be influenced by transport proteins of the ABC superfamily. Coumarin derivatives are poor inhibitors of these proteins and AVKs have a slight effect on the mRNA ABC transporter expression level. Copyright © 2016 John Wiley & Sons, Ltd.
A Delphi study of effective practices for developing competency‐based learning models in higher education
Authors: McIntyre‐Hite Lisa
Published: December 2016

Background

There are over 600 universities developing competency‐based education (CBE) programs in response to student and employer desire to bridge the gap between academic outcomes and employer needs (Fain , https://www.insidehighered.com/news/2015/09/10/amid-competency-based-education-boom-meeting-help-colleges-do-it-right). However, research is still emerging on effective practices for developing CBE programs.

Methods

The purpose of this qualitative Delphi study was to gather expert opinions about effective practices for developing competencies, assessments, and learning resources in CBE programs in higher education. Ten specialists in developing CBE programs served as participants. Data from three rounds of interviews were coded and categorized, using Delphi methodology.

Findings

Eighteen principles for effective practices were agreed upon for developing competencies, 15 principles for effective practice were agreed upon for developing assessments, and 16 principles for effective practice were agreed upon regarding learning resources. Areas of disagreement were also identified, with evidence that variation was due to the unique contexts of higher education programs.

Conclusion

This study contributes to CBE by providing an emerging list of effective practices useful in developing CBE programs.
A Method to Generate and Analyze Modified Myristoylated Proteins
Authors: Gao Huanyao , Sun Wei , Song Zhiquan , Yu Yanbao , Wang Li , Chen Xian , Zhang Qisheng
Published: December 2016

Covalent lipid modification of proteins is essential to their cellular localizations and functions. Engineered lipid motifs, coupled with bio‐orthogonal chemistry, have been utilized to identify myristoylated or palmitoylated proteins in cells. However, whether modified proteins have similar properties as endogenous ones has not been well investigated mainly due to lack of methods to generate and analyze purified proteins. We have developed a method that utilizes metabolic interference and mass spectrometry to produce and analyze modified, myristoylated small GTPase ADP‐ribosylation factor 1 (Arf1). The capacities of these recombinant proteins to bind liposomes and load and hydrolyze GTP were measured and compared with the unmodified myristoylated Arf1. The ketone‐modified myristoylated Arf1 could be further labeled by fluorophore‐coupled hydrazine and subsequently visualized through fluorescence imaging. This methodology provides an effective model system to characterize lipid‐modified proteins with additional functions before applying them to cellular systems.
Identification of N‐Arylated NH125 Analogues as Rapid Eradicating Agents against MRSA Persister Cells and Potent Biofilm Killers of Gram‐Positive Pathogens
Authors: Abouelhassan Yasmeen , Basak Akash , Yousaf Hussain , Huigens Robert W.
Published: December 2016

Bacterial biofilms housing dormant persister cells are innately tolerant to antibiotics and disinfectants, yet several membrane‐active agents are known to eradicate tolerant bacterial cells. NH125, a membrane‐active persister killer and starting point for development, led to the identification of two N‐arylated analogues (1 and 2) that displayed improved biofilm eradication potencies compared to the parent compound and rapid persister‐cell‐killing activities in stationary cultures of methicillin‐resistant Staphylococcus aureus (MRSA). We found 1 and 2 to be superior to other membrane‐active agents in biofilm eradication assays, with 1 demonstrating minimum biofilm eradication concentrations (MBEC) of 23.5, 11.7, and 2.35 μm against MRSA, methicillin‐resistant Staphylococcus epidermidis (MRSE), and vancomycin‐resistant Enterococcus faecium (VRE) biofilms, respectively. We tested our panel of membrane‐active agents against MRSA stationary cultures and found 1 to rapidly eradicate MRSA stationary cells by 4 log units (99.99 %) in 30 min. The potent biofilm eradication and rapid persister‐cell‐killing activities exhibited by N‐arylated NH125 analogues could have significant impact in addressing biofilm‐associated problems.
CYP19A1, MIF and ABCA1 genes are targets of the RORα in monocyte and endothelial cells
Authors: Coban Neslihan , Gulec Cagri , Ozsait‐Selcuk Bilge , Erginel‐Unaltuna Nihan
Published: December 2016

RORα is a member of nuclear receptor superfamily of transcription factors, which has a vital role in the regulation of various physiological processes. Cholesterol is a known ligand of RORα and is one of the key components that take part in cardiovascular diseases such as atherosclerosis. Therefore, it is possible that RORα might have a role in the development of atherosclerosis. To test this hypothesis, we investigated the presence of novel RORα response elements (ROREs) located in the promoter of CYP19A1, MIF and ABCA1 genes. Briefly, the occupancy of RORα in the promoter regions of these genes was demonstrated in THP‐1 and HUVEC cell lines by ChIP analysis. In order to modulate RORα activity, THP‐1 and HUVEC cells were treated with specific RORα ligands (CPG 52608 and SR1001) and then the expression levels of target genes were analysed. In the next step, we tested whether RORα activity in THP‐1 macrophages was influenced by the presence of simvastatin, a cholesterol lowering drug. We found that in the presence of simvastatin the expression of the investigated target genes were down regulated and that this regulation was partially prevented by CPG 52608 and SR1001. Results of this study suggest that CYP19A1, MIF and ABCA1 are the direct target genes of RORα. In conclusion, it is important to demonstrate that certain genes involved in the development of atherosclerosis could be modulated by an inducible transcription factor. Therefore, these results offer a potential therapeutic approach for the treatment of atherosclerosis.
General Synthetic Protocol for the Synthesis of Ru‐X (X=Rh, Pd, Ag) Heterogeneous Ultrathin Nanowires with a Tunable Composition
Authors: Sun Dalei , Yu Hong , Su Hao , Jin Feng , Liu Jincheng , Li Cheng Chao
Published: December 2016

Herein, a wet‐chemical strategy was devised for the preparation of ultrathin Ru‐based (Ru‐Pd, Ru‐Ag, and Ru‐Rh) heterogeneous nanowires without the use of templates and organic solvents. The success of this synthetic strategy relies on the combination of heterogeneous nucleation and oriented attachment processes. In the synthesis, polyvinylpyrrolidone (PVP) and sodium iodide play very important roles in the growth of the ultrathin nanowires. PVP induces the linear attachment of Ru‐based nanostructures, and I− ions effectively tune the reaction kinetics of the reduction of the metal ions through the formation of more stable compounds. The average diameter of the Ru‐based nanowires is only 3 nm, approximately 12 atoms thick. Importantly, the components of the ultrathin nanowires can be tuned easily by changing the types of precursors and concentrations. As a result of the ultrathin structure and heterojunctions, the as‐synthesized Ru‐based ultrathin nanowires exhibit a good catalytic activity in the Suzuki–Miyaura reaction with a low loss of catalytic activity after several reuses.
Three‐Dimensional Hierarchical Porous Nitrogen and Sulfur‐Codoped Graphene Nanosheets for Oxygen Reduction in Both Alkaline and Acidic Media
Authors: Huang Zheng , Zhou Haihui , Yang Wenji , Fu Chaopeng , Chen Liang , Kuang Yafei
Published: December 2016

Heteroatom‐doped carbon materials show superior oxygen reduction reaction (ORR) performance and served as alternatives to Pt‐based catalysts for the commercialization of fuel cells. However, these doped carbon materials only show good ORR activity in alkaline medium, they are generally less effective in acidic electrolytes. The appropriate combination of high dopant distribution and engineered morphology of doped carbon materials is essential to realize high ORR performance. Herein, we propose a novel and effective approach to synthesize three‐dimensional hierarchical porous nitrogen and sulfur‐codoped graphene nanosheets (NSG) as ORR catalysts in both alkaline and acid media. Firstly, the self‐assembled pyrrole layer was polymerized on graphene oxide template to form a molecule‐thick polypyrrole (PPy) layer using (NH4)2S2O8 oxidant, resulting in a sandwich‐like S‐containing PPy/GO nanosheets (S–PPy–GO–PPy–S), then the S–PPy–GO–PPy–S was pyrolyzed to generate 3 D hierarchical porous NSG with uniformly distributed high level multiple dopant (9.05 at % of N and 1.65 at % of S). As a result, the NSG exhibits comparable or even better ORR performance in both alkaline and acid media than the noble metal Pt/C catalyst. The achieved high performance is ascribed to the uniformly distributed high content doped elements and three‐dimensional hierarchical porous structure, providing more active sites for ORR.
X‐ray Crystal Structure of a Metalled Double‐Helix Generated by Infinite and Consecutive C*‐AgI‐C* (C*:N1‐Hexylcytosine) Base Pairs through Argentophilic and Hydrogen Bond Interactions
Authors: Terrón Angel , Moreno‐Vachiano Blas , Bauzá Antonio , García‐Raso Angel , Fiol Juan Jesús , Barceló‐Oliver Miquel , Molins Elies , Frontera Antonio
Published: December 2016

The synthesis of a metalled double‐helix containing exclusively silver‐mediated C*−C* base pairs is reported herein (C*=N1hexylcytosine). Remarkably, it is the first crystal structure containing infinite and consecutive C*‐AgI‐C* base pairs that form a double helix. The AgI ion occupies the center between two C* residues with N(3)−Ag bond lengths of 2.1 Å and short AgI−AgI distances (3.1 Å) suggesting an interesting argentophilic attraction as a stabilization source of the helical disposition. The solid‐state structure is further stabilized by metal‐mediated base‐pairs, hydrogen bonding and π‐stacking interactions. Moreover, the angle N(3)−Ag‐N(3) is almost linear in the [Ag(N1hexylcytosine)2]+ motif and the bases are not coplanar, thus generating a double‐strand helical aggregate in the solid state. The noncovalent and argentophilic interactions have been rationalized based on DFT calculations.
NMR Hyperpolarization Techniques of Gases
Authors: Barskiy Danila A. , Coffey Aaron M. , Nikolaou Panayiotis , Mikhaylov Dmitry M. , Goodson Boyd M. , Branca Rosa T. , Lu George J. , Shapiro Mikhail G. , Telkki Ville‐Veikko , Zhivonitko Vladimir V. , Koptyug Igor V. , Salnikov Oleg G. , Kovtunov Kirill V. , Bukhtiyarov Valerii I. , Rosen Matthew S. , Barlow Michael J. , Safavi Shahideh , Hall Ian P. , Schröder Leif , Chekmenev Eduard Y.
Published: December 2016

Invited for the cover of this issue is a group of researchers coordinated by E. Y. Chekmenev from Vanderbilt University. The image depicts hyperpolarized Xe‐129 and parahydrogen gases and their MRI applications. Read the full text of the article at 10.1002/chem.201603884.
Viral oncoprotein antibodies as a marker for recurrence of Merkel cell carcinoma: A prospective validation study
Authors: Paulson Kelly G. , Lewis Christopher W. , Redman Mary W. , Simonson William T. , Lisberg Aaron , Ritter Deborah , Morishima Chihiro , Hutchinson Kathleen , Mudgistratova Lola , Blom Astrid , Iyer Jayasri , Moshiri Ata S. , Tarabadkar Erica S. , Carter Joseph J. , Bhatia Shailender , Kawasumi Masaoki , Galloway Denise A. , Wener Mark H. , Nghiem Paul
Published: December 2016

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive skin cancer with a recurrence rate of >40%. Of the 2000 MCC cases per year in the United States, most are caused by the Merkel cell polyomavirus (MCPyV). Antibodies to MCPyV oncoprotein (T‐antigens) have been correlated with MCC tumor burden. The present study assesses the clinical utility of MCPyV‐oncoprotein antibody titers for MCC prognostication and surveillance.

METHODS

MCPyV‐oncoprotein antibody detection was optimized in a clinical laboratory. A cohort of 219 patients with newly diagnosed MCC were followed prospectively (median follow‐up, 1.9 years). Among the seropositive patients, antibody titer and disease status were serially tracked.

RESULTS

Antibodies to MCPyV oncoproteins were rare among healthy individuals (1%) but were present in most patients with MCC (114 of 219 patients [52%]; P < .01). Seropositivity at diagnosis independently predicted decreased recurrence risk (hazard ratio, 0.58; P = .04) in multivariate analyses adjusted for age, sex, stage, and immunosuppression. After initial treatment, seropositive patients whose disease did not recur had rapidly falling titers that became negative by a median of 8.4 months. Among seropositive patients who underwent serial evaluation (71 patients; 282 time points), an increasing oncoprotein titer had a positive predictive value of 66% for clinically evident recurrence, whereas a decreasing titer had a negative predictive value of 97%.

CONCLUSIONS

Determination of oncoprotein antibody titer assists in the clinical management of patients with newly diagnosed MCC by stratifying them into a higher risk seronegative cohort, in which radiologic imaging may play a more prominent role, and into a lower risk seropositive cohort, in which disease status can be tracked in part by oncoprotein antibody titer. Cancer 2017;123:1464–1474. © 2016 American Cancer Society.
Preoperative characteristics and cytological features of 136 histologically confirmed pancreatic mucinous cystic neoplasms
Authors: Scourtas Aristana , Dudley Jonathan C. , Brugge William R. , Kadayifci Abdurrahman , Mino‐Kenudson Mari , Pitman Martha B.
Published: December 2016

BACKGROUND

Mucinous cystic neoplasms (MCNs) of the pancreas present a management conundrum. The majority are benign but all are resected due to their malignant potential. Recent studies have recommended nonsurgical management. In the current study, the authors analyzed the preoperative imaging, cytology, and cyst fluid characteristics of 136 histologically confirmed MCNs to assess predictors of a high‐risk (HR) cyst for surgical triage.

METHODS

MCNs resected at the Massachusetts General Hospital between 1990 and 2014 formed the study cohort. Patient demographics, cyst size, and mural nodules (MNs) by endoscopic ultrasound, cytology, and cyst fluid carcinoembryonic antigen and amylase levels were correlated with histological grade. A HR cyst was defined as high‐grade dysplasia or invasive carcinoma on histology. Performance characteristics were assessed for each parameter, with a cyst size ≥3 cm or a MN on imaging and malignant cytology considered to be “true‐positive” results for predicting malignancy.

RESULTS

Only 15 of the 136 cysts had HR histology (11%). On average, patients with HR cysts were older than those with low‐risk cysts (55 years vs 49 years, respectively). High‐grade cytology was the most accurate predictor of malignancy (95%) followed by MN and cyst size together (88%) and MN alone (83%). The average carcinoembryonic antigen level (in ng/mL) increased with the grade of dysplasia but the ranges overlapped between low risk and HR cysts.

CONCLUSIONS

To the authors' knowledge, the current study is the largest series to date analyzing the cytological features of histologically confirmed MCN. Cytology is insensitive but very specific for detecting a HR MCN and outperformed imaging for the detection of HR MCN. Endoscopic ultrasound‐guided fine‐needle aspiration and cytology should be performed on any clinically suspected MCN that is being considered for conservative management. Cancer Cytopathol 2017;125:169–177. © 2016 American Cancer Society.
The Influence of Morphology and PbI2 on the Intrinsic Trap State Distribution in Perovskite Films Determined by Using Temperature‐Dependent Fluorescence Spectroscopy
Authors: Wang Yi , Wang Hao‐Yi , Yu Man , Fu Li‐Min , Qin Yujun , Zhang Jian‐Ping , Ai Xi‐Cheng
Published: December 2016

Perovskite films with different particle sizes and PbI2 contents were prepared by using a controlled single or sequential method. By means of temperature‐dependent fluorescence spectroscopy, the energetic distribution of intrinsic intragap trap states in perovskite was quantitatively determined, and the radiative charge recombinations through the band edge and via trap states were studied. Furthermore, a series of thermodynamic parameters, such as the demarcation energy between radiative and nonradiative recombination regions, detrapping activation energy, and characteristic temperature, were extracted based on which of the possible radiative and nonradiative recombination mechanisms were proposed. In addition, the correlation between the morphology of the perovskite films, the PbI2 content, and the energetic distribution of the trap states was investigated. Finally, we discuss the structure–function relationship of perovskite films prepared by different methods.
Room‐Temperature Atomic Layer Deposition of Al2O3: Impact on Efficiency, Stability and Surface Properties in Perovskite Solar Cells
Authors: Kot Malgorzata , Das Chittaranjan , Wang Zhiping , Henkel Karsten , Rouissi Zied , Wojciechowski Konrad , Snaith Henry J. , Schmeisser Dieter
Published: December 2016

In this work, solar cells with a freshly made CH3NH3PbI3 perovskite film showed a power conversion efficiency (PCE) of 15.4 % whereas the one with 50 days aged perovskite film only 6.1 %. However, when the aged perovskite was covered with a layer of Al2O3 deposited by atomic layer deposition (ALD) at room temperature (RT), the PCE value was clearly enhanced. X‐ray photoelectron spectroscopy study showed that the ALD precursors are chemically active only at the perovskite surface and passivate it. Moreover, the RT‐ALD‐Al2O3‐covered perovskite films showed enhanced ambient air stability.
Iodide‐Photocatalyzed Reduction of Carbon Dioxide to Formic Acid with Thiols and Hydrogen Sulfide
Authors: Berton Mateo , Mello Rossella , González‐Núñez María Elena
Published: December 2016

The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low‐pressure mercury lamp. This transition‐metal‐free photocatalytic process for CO2 capture coupled with H2S removal may have been relevant as a prebiotic carbon dioxide fixation.
In Situ Raman Spectroscopic Studies on Concentration of Electrolyte Salt in Lithium‐Ion Batteries by Using Ultrafine Multifiber Probes
Authors: Yamanaka Toshiro , Nakagawa Hiroe , Tsubouchi Shigetaka , Domi Yasuhiro , Doi Takayuki , Abe Takeshi , Ogumi Zempachi
Published: December 2016

Lithium‐ion batteries have attracted considerable attention due to their high power density. The change in concentration of salt in the electrolyte solution in lithium‐ion batteries during operation causes serious degradation of battery performance. Herein, a new method of in situ Raman spectroscopy with ultrafine multifiber probes was developed to simultaneously study the concentrations of ions at several different positions in the electrolyte solution in deep narrow spaces between the electrodes in batteries. The total amount of ions in the electrolyte solution clearly changed during operation due to the low permeability of the solid–electrolyte interphase (SEI) at the anode for Li+ permeation. The permeability, which is a key factor to achieve high battery performance, was improved (enhanced) by adding film‐forming additives to the electrolyte solution to modify the properties of the SEI. The results provide important information for understanding and predicting phenomena occurring in a battery and for designing a superior battery. The present method is useful for analysis in deep narrow spaces in other electrochemical devices, such as capacitors.
Regional variation in streamflow drivers across a continental climatic gradient
Authors: Trancoso Ralph , Phinn Stuart , McVicar Tim R. , Larsen Joshua R. , McAlpine Clive A.
Published: December 2016

Streamflow characteristics are driven by specific flow‐generation mechanisms, which are in turn determined by the biophysical properties of catchments. They provide important environmental services for society and ecosystems, regulating water supply and quality, flood mitigation, and the biological diversity of aquatic ecosystems. This study investigates how the drivers of streamflow characteristics vary at the level of regional management (regional [104 km2] and continental scales [107 km2]) in eastern Australia. Three hydrological signatures were used to represent streamflow characteristics: runoff coefficient, baseflow index, and zero flow ratio. Long‐term streamflow data and 24 spatially distributed biophysical properties from 354 catchments in eastern Australia were analysed with random forest and generalized additive beta regression models to determine the dominant drivers of streamflow characteristics. We found that the main drivers of streamflow characteristics cannot be generalized from region to region and that specific biophysical variables govern their spatial variability. However, some important drivers such as the dryness index and the fraction of photosynthetically active radiation from vegetation explain the variability of streamflow characteristics at both regional and continental scales with differing importance. Our findings also suggest that soil properties have a significant effect on streamflow characteristics at regional scales. However, the relative importance of these soil properties varies among regions depending on the streamflow characteristics. This paper demonstrates that the drivers of streamflow characteristics are scale and region dependent, and biogeographically different regions have specific mechanisms governing streamflow. It opens an avenue to better connect the management perspectives of ecology and hydrology.
Catalytic Activity and Mechanism of Co‐Catalysts Used in Combinational Catalysts for Aerobic Oxidation
Authors: Gao Baojiao , Zhang Dandan , Li Yanbin
Published: December 2016

(2,2,6,6‐Tetramethylpiperidin‐1‐yl)oxyl (TEMPO) was immobilized on crosslinked polystyrene (CPS) microspheres by polymer reaction to obtain microspheres of the heterogeneous catalyst TEMPO/CPS. TEMPO/CPS microspheres in combination with different transition metal salts were used in the aerobic oxidation of 1‐phenylethanol. This work focuses on the catalytic activities and mechanisms of various co‐catalysts, and the different behavior of these co‐catalysts is explained for the first time with the theory of redox potentials, so that some important principles for selecting better transition metal salts as co‐catalysts of TEMPO are presented. The experimental results show that 1‐phenylethanol can be oxidized to acetophenone as the sole product with a high conversion of 96 % under mild conditions (at 55 °C and with molecular oxygen at ordinary pressure) by using the combinational catalyst consisting of TEMPO/CPS microspheres and transition metal salts.
Platinum(IV) Prodrugs – A Step Closer to Ehrlich's Vision?
Authors: Kenny Reece G. , Chuah Su Wen , Crawford Alanna , Marmion Celine J.
Published: December 2016

The concept of the “magic bullet”, a medicine designed to hit a specific biological target, was pioneered by Paul Ehrlich, the father of chemotherapy, some 100 years ago. Building on Ehrlich's vision, we have endeavoured to showcase not only how targeted PtIV prodrugs may be exploited to reduce systemic toxicities associated with modern‐day chemotherapeutics, including classical PtII drugs, but also how these prodrugs may overcome resistance issues that have plagued many chemotherapeutic regimes. A summary of advances in this field over the past decade is provided, with an emphasis on PtIV prodrugs that target not only DNA but also enzymes, proteins, peptides and hormones. Synthetic strategies for accessing PtIV chemistry are also provided.
A microfluidic device for the delivery of enzymes into cells by liposome fusion
Authors: Kuhn Phillip , Eyer Klaus , Dittrich Petra S.
Published: December 2016

Liposomes are versatile carriers of drugs or biomolecules and are ideally suited to transport molecules into cells. However, mechanistic studies to understand and improve the fusion of liposomes with cell membranes and endosomes are difficult. Here, we report a method that allows for stable coimmobilization of liposomes and living cells, thereby bringing the membranes into close contact, which is essential for membrane fusion. The small unilamellar liposomes are tethered to the surface by a linker so that no modification of the liposome membrane for cell binding is required. The cells are positioned above the liposomes by posts that are integrated into the microfluidic device, and a pH drop induces the fusion of the cell‐liposome membranes. Both membrane fusion and release of molecules into the cytosol are visualized by fluorescence dequenching assays. Furthermore, we proved the efficient delivery of the enzyme β‐galactosidase into the cells when a fusogenic liposome composition was used. The device could be used for fusion studies but is also a versatile means for cell transfection.
Diagnostic accuracy between readers for identifying electrographic seizures in critically ill adults
Authors: Tu Bin , Young G. Bryan , Kokoszka Agnieszka , Rodriguez‐Ruiz Andres , Varma Jay , Eerikäinen Linda M. , Assassi Nadege , Mayer Stephan A. , Claassen Jan , Särkelä Mika O. K.
Published: December 2016

Objective

Electrographic seizures in critically ill patients are often equivocal. In this study, we sought to determine the diagnostic accuracy of electrographic seizure annotation in adult intensive care units (ICUs) and to identify affecting factors.

Methods

To investigate diagnostic accuracy, interreader agreement (IRA) measures were derived from 5,769 unequivocal and 6,263 equivocal seizure annotations by five experienced electroencephalogram (EEG) readers after reviewing 74 days of EEGs from 50 adult ICU patients. Factors including seizure equivocality (unequivocal vs. equivocal) and laterality (generalized, partial, or bilaterally independent), cyclicity (cyclic vs. noncyclic), persistency (occurrence of status epilepticus), and patient consciousness level (coma vs. noncoma) were further investigated for their influence on IRA measures.

Results

On average, 70% of seizures marked by a reference reader overlapped, at least in part, with those marked by a test reader (any‐overlap sensitivity, AO‐Sn). Agreed seizure duration between reader pairs (overlap‐integral sensitivity, OI‐Sn) was 62%, while agreed nonseizure duration (overlap‐integral specificity, OI‐Sp) was 99%. A test reader would annotate one additional seizure not overlapping with a reference reader's annotation in every 11.7 h of EEG, that is, the false‐positive rate (FPR) was 0.0854/h. Classifying seizure patterns into unequivocal and equivocal improved specificity and FPR (unequivocal patterns) but compromised sensitivity only for equivocal patterns. Sensitivity of all and unequivocal annotations was higher for patients with status epilepticus. Specificity was higher for partial than for bilaterally independent unequivocal seizure patterns, and lower for cyclic all seizure patterns.

Significance

Diagnosing electrographic seizures in critically ill adults is highly specific and moderately sensitive. Improved criteria for diagnosing electrographic seizures in the ICU are needed.
Damage‐based seismic planar pounding analysis of adjacent symmetric buildings considering inelastic structure–soil–structure interaction
Authors: Ghandil Mehdi , Aldaikh Hesham
Published: December 2016

In cities and urban areas, building structures located at close proximities inevitably interact under dynamic loading by direct pounding and indirectly through the underlying soil. Majority of the previous adjacent building pounding studies that have taken the structure–soil–structure interaction (SSSI) problem into account have used simple lumped mass–spring–dashpot models under plane strain conditions. In this research, the problem of SSSI‐included pounding problem of two adjacent symmetric in plan buildings resting on a soft soil profile excited by uniaxial earthquake loadings is investigated. To this end, a series of SSSI models considering one‐directional nonlinear impact elements between adjacent co‐planar stories and using a method for direct finite element modeling of 3D inelastic underlying soil volume has been developed to accurately study the problem. An advanced inelastic structural behavior parameter, the seismic damage index, has been considered in this study as the key nonlinear structural response of adjacent buildings. Based on the results of SSSI and fixed base case analyses presented herein, two main problems are investigated, namely, the minimum building separation distance for pounding prevention and seismic pounding effects on structural damage in adjacent buildings. The final results show that at least three times, the International Building Code 2009 minimum distance for building separation recommended value is required as a clear distance for adjacent symmetric buildings to prevent the occurrence of seismic pounding. At the International Building Code‐recommended distance, adjacent buildings experienced severe seismic pounding and therefore significant variations in storey shear forces and damage indices. Copyright © 2016 John Wiley & Sons, Ltd.
Spatial seismic modeling of base‐isolated buildings pounding against moat walls: effects of ground motion directionality and mass eccentricity
Authors: Mavronicola Eftychia A. , Polycarpou Panayiotis C. , Komodromos Petros
Published: December 2016

Structural impact between adjacent buildings may induce local and, in some extreme cases, severe damage, especially in the case of seismically isolated buildings. This study parametrically investigates in the three‐dimensional domain the effect of pounding on the peak response of base‐isolated buildings, which are simulated as nonlinear three‐dimensional multi‐degree‐of‐freedom systems. Firstly, it is shown that considering unidirectional, instead of bidirectional, excitations may lead to underestimation of the base drift demands. Subsequently, the peak responses of seismically isolated buildings utilizing lead rubber bearings are studied while varying important parameters, such as the incidence angle of seismic excitations, the available seismic clearance, and mass eccentricities, under the action of bidirectional horizontal excitations. A large number of numerical simulations are performed using a specially developed software that implements an efficient approach to model impacts, taking into account arbitrary locations of contact points. It is found that the peak interstory drift ratio is significantly influenced by the directionality of the ground motion. Therefore, the seismic performance of structures should ideally be assessed examining the peak structural response while bidirectional ground motions are imposed at various incident angles. Furthermore, it is also observed that the interstory drift ratios increase while decreasing the available gap size, up to a certain value. Finally, the parametric analyses indicate that the effects of impact are more severe for structures with mass eccentricities, and in which case, the estimation of the critical incidence angle becomes more laborious. Copyright © 2016 John Wiley & Sons, Ltd.
Biochemical response of the Africanized honeybee exposed to fipronil
Authors: Roat Thaisa C. , Carvalho Stephan M. , Palma Mário S. , Malaspina Osmar
Published: December 2016

Bees are recognized worldwide for their social, economic, and environmental value. In recent decades they have been seriously threatened by diseases and high levels of pesticide use. The susceptibility of bees to insecticides makes them an important terrestrial model for assessing environmental quality, and various biomarkers have been developed for such assessments. The present study aimed to evaluate the activity of the enzymes acetylcholinesterase (AChE), carboxylesterase (CaE), and glutathione-S-transferase (GST) in Africanized honeybees exposed to fipronil. The results showed that fipronil at a sublethal dose (0.01 ng/bee) modulates the activity of CaE in all isoforms analyzed (CaE-1, CaE-2, and CaE-3) in both newly emerged and aged bees, and does not affect the activity of AChE or GST. The recovery of the bees after fipronil exposure was also investigated, and these results demonstrated that even the cessation of fipronil ingestion might not lead to complete recovery of individual bees. Even at low doses, fipronil was shown to cause changes in the activity of key enzymes in bees. The possible consequences of these changes are discussed. Environ Toxicol Chem 2017;36:1652–1660. © 2016 SETAC
Identification of sources of metal in the agricultural soils of the Guanzhong Plain, northwest China
Authors: Deng Wenbo , Li Xuxiang , An Zhisheng , Yang Liu , Hou Kang , Zhang Yue
Published: December 2016

A comprehensive survey was conducted to assess the possible sources and distribution of metals in the agricultural soils of the Guanzhong Plain in northwest China. In total, 227 samples of agricultural soil were collected to determine the content of Pb, Cr, Co, V, Ni, Zn, Cu, As, and Mn by X-ray fluorescence spectrometry. The mean concentrations of metals were 26.2 ± 10.8 mg kg­–1, 71.5 ± 16.8 mg kg−1, 12.7 ± 1.81 mg kg−1, 85.1 ± 7.86 mg kg−1, 30.5 ± 6.17 mg kg−1, 71.1 ± 14.1 mg kg−1, 25.2 ± 5.58 mg kg−1, 12.5 ± 1.94 mg kg−1, and 635.4 ± 84.7 mg kg−1 for Pb, Cr, Co, V, Ni, Zn, Cu, As, and Mn, respectively—slightly higher than the regional background values. Multivariate analysis was used to identify the metal sources, and it was found that Ni and Cr in the agricultural soils were mainly derived from lithological materials, and Pb, Zn, and Cu were mainly from traffic emissions; however, Zn and Cu also originated from mineral fertilizers or pesticides. The other metals originated from industrial emissions. The Nemerow index coupled with geographic information system technology was applied to assess the degree and spatial distribution of metal contamination; the soils studied were classified as slightly polluted, and the most contaminated regions were concentrated in the area surrounding Xi'an city, as well as areas in the southeast and north of the Guanzhong Plain. Environ Toxicol Chem 2017;36:1510–1516. © 2016 SETAC
Haloperidol increases false recognition memory of thematically related pictures in healthy volunteers
Authors: Guarnieri Regina V. , Buratto Luciano G. , Gomes Carlos F.A. , Ribeiro Rafaela L. , de Souza Altay A. Lino , Stein Lilian M. , Galduróz José C. , Bueno Orlando F.A.
Published: December 2016

Dopamine can modulate long‐term episodic memory. Its potential role on the generation of false memories, however, is less well known. In a randomized, double‐blind, placebo‐controlled experiment, 24 young healthy volunteers ingested a 4‐mg oral dose of haloperidol, a dopamine D2‐receptor antagonist, or placebo, before taking part in a recognition memory task. Haloperidol was active during both study and test phases of the experiment. Participants in the haloperidol group produced more false recognition responses than those in the placebo group, despite similar levels of correct recognition. These findings show that dopamine blockade in healthy volunteers can specifically increase false recognition memory.
Potential of long non‐coding RNAs in cancer patients: From biomarkers to therapeutic targets
Authors: Chandra Gupta Subash , Nandan Tripathi Yashoda
Published: December 2016

Because of high specificity and easy detection in the tissues, serum, plasma, urine and saliva, interest in exploring the potential of long non‐coding RNAs (lncRNAs) in cancer patients continues to increase. LncRNAs have shown potential as a biomarker in the diagnosis and prognosis of bladder cancer, prostate cancer, gastric cancer, pancreatic cancer, breast cancer and many other cancer types. Some lncRNAs have also been used as adjunct to improve the specificity and sensitivity of existing biomarkers. The molecular tools such as RNA‐seq, RNA‐FISH, ic‐SHAPE and quantitative real‐time PCR have been used for examining the lncRNAs' potential. Some lncRNAs such as PCA3 is now routinely used in the clinic for the diagnosis of prostate cancer. Single nucleotide polymorphisms (SNPs) in lncRNAs can also be used as a predictor of cancer risk. Although ongoing studies continue to unravel the underlying mechanism, some lncRNAs have been used as therapeutic targets for the selective killing of cancer cells in patients. Thus lncRNAs are emerging as convenient and minimally invasive diagnostic/prognostic markers, and also as therapeutic target. Companies such as the Curna Inc., MiNA Therapeutics Ltd. and RaNA Therapeutics Inc. have been taking steps to develop lncRNA based strategies against cancer. In this review, we discuss the potential of lncRNAs as biomarkers and therapeutic targets in cancer patients.