bluuebunny/crossref_metadata_2025 huggingface dataset:
Two‐Dimensional Organic–Inorganic Hybrid Perovskites: A New Platform for Optoelectronic Applications
Authors: Hu Jun , Yan Liang , You Wei
Published: September 2018

2D perovskites are recently attracting a significant amount of attention, mainly due to their improved stability compared with their 3D counterpart, e.g., the archetypical MAPbI3. Interestingly, the first studies on 2D perovskites can be dated back to the 1980s. The most popular 2D perovskites have a general formula of (RNH3)2MAn−1MnX3n+1, where n represents the number of metal halide octahedrons between the insulating organic cation layers. The optoelectronic properties of 2D perovskites, e.g., band gap, are highly dependent on the thickness of the inorganic layers (i.e., the value of n). Herein, 2D perovskites are arbitrarily divided into three classes, strict 2D (n = 1), quasi‐2D (n = 2–5), and quasi‐3D (n > 5), and research progress is summarized following this classification. The majority of existing 2D perovskites only employ very simple organic cations (e.g., butyl ammonium or phenylethyl ammonium), which merely function as the supporting layer/insulating barrier to achieve the 2D structure. Thus, a particularly important research question is: can functional organic cations be designed for these 2D perovskites, where these functional organic cations would play an important role in dictating the optoelectronic properties of these organic–inorganic hybrid materials, leading to unique device performance or applications?
Combining In Silico Design and Biomimetic Assembly: A New Approach for Developing High‐Performance Dynamic Responsive Bio‐Nanomaterials
Authors: Ling Shengjie , Jin Kai , Qin Zhao , Li Chunmei , Zheng Ke , Zhao Yanyan , Wang Qi , Kaplan David L. , Buehler Markus J.
Published: September 2018

Major challenge remains in the design and fabrication of artificial hierarchical materials that mimic the structural and functional features of these natural materials. Here, a novel biomimetic strategy to assemble hierarchical materials from biological nanobuilding blocks is demonstrated. The constituents and structures of the materials are designed by multiscale modeling and then experimentally constructed by multiscale self‐assembly. The resultant materials that consist of silk nanofibrils (SNFs), hydroxyapatite (HAP), and chitin nanofibrils (CNFs) show nacre‐like structures with mechanical strength and toughness better than most natural nacre and nacre‐like nanocomposites. In addition, these SNF/HAP:CNF nanocomposites can be programmed into “grab‐and‐release” actuators due to the gradient structure of the nanocomposites as well as the high water sensitivity of each of the components, and thusshow potential applications in the design of novel third‐generation biomaterials for potential clinical applications. In addition, this “in silico design and biomimetic assembly” route represents a rational, low‐cost, and efficient strategy for the design and preparation of robust, hierarchical, and functional nanomaterials to meet a variety of application requirements in bio‐nanotechnologies.
Resonance‐Activated Spin‐Flipping for Efficient Organic Ultralong Room‐Temperature Phosphorescence
Authors: Tao Ye , Chen Runfeng , Li Huanhuan , Yuan Jie , Wan Yifang , Jiang He , Chen Cailin , Si Yubing , Zheng Chao , Yang Baocheng , Xing Guichuan , Huang Wei
Published: September 2018

Triplet‐excited‐state‐involved photonic and electronic properties have attracted tremendous attention for next‐generation technologies. To populate triplet states, facile intersystem crossing (ISC) for efficient exciton spin‐flipping is crucial, but it remains challenging in organic molecules free of heavy atoms. Here, a new strategy is proposed to enhance the ISC of purely organic optoelectronic molecules using heteroatom‐mediated resonance structures capable of promoting spin‐flipping at large singlet–triplet splitting energies with the aid of the fluctuation of the state energy and n‐orbital component upon self‐adaptive resonance variation. Combined experimental and theoretical investigations confirm the key contributions of the resonance variation to the profoundly promoted spin‐flipping with ISC rate up to ≈107 s−1 in the rationally designed NPX (X = O or S) resonance molecules. Importantly, efficient organic ultralong room‐temperature phosphorescence (OURTP) with simultaneously elongated lifetime and improved efficiency results overcoming the intrinsic competition between the OURTP lifetime and efficiency. With the spectacular resonance‐activated OURTP molecules, time‐resolved and color‐coded quick response code devices with multiple information encryptions are realized, demonstrating the fundamental significance of this approach in boosting ISC dynamically for advanced optoelectronic applications.
Photocatalytic Properties and Mechanistic Insights into Visible Light‐Promoted Aerobic Oxidation of Sulfides to Sulfoxides via Tin Porphyrin‐Based Porous Aromatic Frameworks
Authors: Jiang Jun , Luo Rongchang , Zhou Xiantai , Chen Yaju , Ji Hongbing
Published: September 2018

Using concepts of biomimetic catalysis, a kind of tin porphyrin‐based porous aromatic framework (SnPor@ PAF) with broad and strong optical absorption in the visible light region was successfully synthesized and subsequently used in the aerobic oxidation of sulfides to sulfoxides under ambient conditions and visible light irradiation, in which exhibited enzyme‐like features of high efficiency and high selectivity. More interestingly, heterogeneous SnPor@PAF was naturally regarded as an intriguing and versatile photosensitizer for photocatalytic transformation and could be reused several times because of its robust and rigid porphyrin framework. As expected, their π‐conjugated structure characteristic in the molecular skeleton might facilitate the activation of molecular oxygen under mild reaction conditions and promoted the production of reactive oxygen species (singlet oxygen (1O2) and superoxide radical anion (O2.−)), which would involve energy transfer and/or electron transfer process. Experimental investigations including emission quenching experiment, oxygen‐isotope labelling, typical inhibition experiments, classical fluorescence probe study, photo‐oxidation of α‐terpinene and in situ electron spin resonance, could provide a mechanistic insight into the photocatalytic reactions.

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The impact of brand equity on the financial performance of marketing cooperatives
Authors: Grashuis Jasper
Published: September 2018

Because of inherent constraints, few farmer cooperatives use branding to pursue differentiation and competitiveness in the agri‐food industry. Considering the complete lack of applied research on the brand–performance relationship for farmer cooperatives, it is unknown if branding is even profitable. This paper addresses the gap in our understanding with a novel panel study of 707 US marketing cooperatives for the 2005–2011 period. Informed by lagged observations of trademark and service mark data, the empirical analysis indicates a positive relationship of brand equity to the financial performance of marketing cooperatives. Specifically, 1% increases in the total stock of trademarks and service marks have a positive impact of $130,441 and $141,921, respectively, on the net sales of the mean marketing cooperative. The corresponding impact on net income is estimated at $3,815 and $17,286, respectively. Following the estimation of further specifications, there is also indication most of the impact is facilitated by older trademarks (>3 years) in the stock, which implies a delayed impact of brand equity on financial performance. Overall, the reported evidence serves as motivation to directors and managers of marketing cooperatives to pursue opportunities to build brand equity. To do so, however, may first require a solution to the equity constraint which appears at the foundation of most farmer cooperatives.
Signal regulatory protein alpha blockade potentiates tumoricidal effects of macrophages on gastroenterological neoplastic cells in syngeneic immunocompetent mice
Authors: Abe Tomoyuki , Tanaka Yuka , Piao Jinlian , Tanimine Naoki , Oue Naohide , Hinoi Takao , Garcia Noel Verjan , Miyasaka Masayuki , Matozaki Takashi , Yasui Wataru , Ohdan Hideki
Published: September 2018

Aim

Immunotherapies blocking the CD47‐SIRPα pathway by targeting CD47 enhance macrophage phagocytosis of neoplastic cells in mouse models. As SIRPα exhibits relatively restricted tissue expression, SIRPα antagonists may be better tolerated than agents targeting CD47, which is ubiquitously expressed in many tissues. Here, we investigated the therapeutic impact of monoclonal antibodies (mAbs) against CD47 and/or SIRPα on gastroenterological tumors in syngeneic immunocompetent mouse models.

Methods

We used in vitro and in vivo phagocytosis assays in C57BL/6J (B6) mice to investigate anti‐CD47/SIRPα mAb effects on Hepa1‐6 and CMT93 originating from B6 mice. The influence of these mAbs on macrophage transmigration was also assessed. To investigate anti‐SIRPα mAb therapy‐induced inhibitory effects on sporadic colon cancer growth, we used a CDX2P9.5‐NLS Cre;APC+/FLOX (CPC‐APC) mouse model.

Results

Systemic anti‐SIRPα mAb administration significantly increased Hepa1‐6 and CMT93 cell susceptibility to macrophage phagocytosis, both in vitro and in vivo. Conversely, similarly administered anti‐CD47 mAb did not promote macrophage phagocytosis of target cells, whereas cells incubated with anti‐CD47 mAb prior to inoculation were more susceptible to macrophage phagocytosis. In vitro cell migration assays revealed that binding with anti‐CD47 mAb inhibited macrophage transmigration. Anti‐SIRPα mAb treatment inhibited tumor progression in CPC‐APC mice and significantly improved overall survival. Anti‐CD47 mAb administration in vivo eliminated the phagocytosis‐promoting CD47 blockade effect, probably by inhibiting macrophage transmigration/chemotaxis. In contrast, anti‐SIRPα mAb exhibited enhanced macrophage phagocytic activity and marked anti‐tumor effects against gastroenterological malignancies.

Conclusion

SIRPα mAb augmentation of macrophage phagocytic activity may represent an effective treatment strategy for human gastrointestinal tumors.
The 4D Dirac Equation in Five Dimensions
Authors: Breban Romulus
Published: September 2018

The Dirac equation may be thought as originating from a theory of 5D space‐time. One way to formulate such a theory relies on a special 5D Clifford algebra and a spin‐1/2 constraint equation for describing null propagation in the 5D space‐time. The 5D null formalism breaks down to four dimensions to recover two single‐particle theories: Dirac's relativistic quantum mechanics and a formulation of spin‐1/2 statistical mechanics. Exploring the non‐relativistic limit in five and four dimensions, a new spin–electric interaction is identified, with possible applications to magnetic resonance spectroscopy (within quantum mechanics) and superconductivity (within statistical mechanics).
Studying the variability of the X‐ray spectral parameters of high‐redshift GRBs' afterglows
Authors: Rácz I. I. , Hortobagyi A. J.
Published: September 2018

The Swift satellite has observed more than a thousand γ‐ray bursts (GRBs) with X‐ray data. Almost a third of them have redshift measurement, too. Here we start to investigate the X‐ray spectral fitting of the data considering the low‐energy part where the N(H) absorption takes place. Based on the available more accurate input data, we examine the robustness of previous fittings and test how sensitive the changes of the starting parameters are. We study the change of the intrinsic hydrogen column density during the outburst for a few events. No significant variability of the N(H) column density is identified.
Fermi GBM GRBs' multivariate statistics
Authors: Racz I. I. , Balázs L. G. , Bagoly Z. , Horvath I. , Tóth L. V.
Published: September 2018

Studying their gamma‐ray spectra may reveal some physical information on γ‐ray bursts (GRBs). The Fermi satellite has observed more than 2,000 GRBs. The FERMIGBRST catalog contains the GRB parameters (peak energy, spectral indices, intensity) estimated for both the total emission (fluence) and the emission during the interval of the peak flux. We found a relationship with linear discriminant analysis between the spectral categories and the model‐independent physical data. We compared the Swift and Fermi spectral types, and found a connection between the Fermi fluence spectra and the Swift spectra, but the result of the peak flux spectra can be disputable. We found that those GRBs that were observed by both Swift and Fermi can similarly discriminate as the complete Fermi sample. We conclude that the common observation probably did not find any trace of selection effects in the spectral behavior of GRBs.
Testing the validity of value‐added measures of educational progress with genetic data
Authors: Morris Tim T. , Davies Neil M. , Dorling Danny , Richmond Rebecca C. , Smith George Davey
Published: September 2018

Value‐added measures of educational progress have been used by education researchers and policy‐makers to assess the performance of teachers and schools, contributing to performance‐related pay and position in school league tables. They are designed to control for all underlying differences between pupils and should therefore provide unbiased measures of school and teacher influence on pupil progress, however, their effectiveness has been questioned. We exploit genetic data from a UK birth cohort to investigate how successfully value‐added measures control for genetic differences between pupils. We use raw value‐added, contextual value‐added (which additionally controls for background characteristics) and teacher‐reported value‐added measures built from data at ages 11, 14 and 16. Sample sizes for analyses range from 4,600 to 6,518. Our findings demonstrate that genetic differences between pupils explain little variation in raw value‐added measures but explain up to 20% of the variation in contextual value‐added measures (95% CI = 6.06% to 35.71%). Value‐added measures built from teacher‐rated ability have a greater proportion of variance explained by genetic differences between pupils, with 36.3% of their cross‐sectional variation being statistically accounted for by genetics (95% CI = 22.8% to 49.8%). By contrast, a far greater proportion of variance is explained by genetic differences for raw test scores at each age of at least 47.3% (95% CI: 35.9 to 58.7). These findings provide evidence that value‐added measures of educational progress can be influenced by genetic differences between pupils, and therefore may provide a biased measure of school and teacher performance. We include a glossary of genetic terms for educational researchers interested in the use of genetic data in educational research.
Development of Capacitance Tools: At‐Line Method for Assessing Biomass of Mammalian Cell Culture and Fixed Cell Calibration Standard
Authors: Fernandes Juhi , Currie Jayme , Ramer Kevin , Zhang An
Published: September 2018

Capacitance is used to monitor “biomass” in cell culture and fermentation processes. The present work explores various ways to support good manufacturing practices (GMP) use and create robust methods that can assure proper performance of capacitance equipment. An at‐line capacitance measurement method is particularly valuable as it can be used to correct or confirm online measurements from bioreactors. To obtain consistent predictions of online capacitance, the at‐line method requires appropriate control of culture temperature, vessel geometry, mixing, and timing. The at‐line method yields values that differ systematically from online values, but the variation is ≤11% for two cell lines tested. A cell line‐specific conversion factor addresses the difference and enables accurate predictions of online capacitance values. In addition to the at‐line method, verification of equipment performance is further enabled by using formaldehyde‐treated cell standards. The cell‐derived standards create a stabilized system for studying capacitance and recapitulate the performance of metabolically active cell culture. The formaldehyde‐treated cells, however, require a much greater conversion factor to predict online outputs. The stabilized system proves useful for evaluation and calibration of capacitance measuring systems. The at‐line method and stabilized cell‐derived suspensions support use of capacitance for process control in large scale mammalian cell culture.
Multicentre study of the prognostic impact of preoperative bodyweight on long-term prognosis of hepatocellular carcinoma
Authors: Yu J J , Shen F , Chen T H , Liang L , Han J , Xing H , Zhou Y H , Wang H , Gu W M , Lau W Y , Yang T
Published: September 2018

Background

Whether preoperative bodyweight is associated with long-term prognosis in patients after liver resection for hepatocellular carcinoma (HCC) is controversial. This study aimed to investigate the relationship of patient weight with long-term recurrence and overall survival (OS) after curative liver resection for HCC.

Methods

Data for patients with HCC who underwent curative liver resection between 2000 and 2015 in five centres in China were analysed retrospectively in three groups according to their preoperative BMI: underweight (BMI 18·4 kg/m2 or less), normal weight (BMI 18·5–24·9 kg/m2) and overweight (BMI 25·0 kg/m2 or above). Patients' baseline characteristics, operative variables and long-term survival outcomes were compared. Univariable and multivariable Cox regression analyses were performed to identify risk factors for OS and recurrence-free survival (RFS) after resection.

Results

Of 1524 patients, 107 (7·0 per cent) were underweight, 891 (58·5 per cent) were of normal weight and 526 (34·5 per cent) were overweight. Univariable analyses showed that underweight and overweight patients had poorer OS (both P < 0·001) and RFS (both P < 0·001) than patients of normal weight. Multivariable Cox regression analysis also identified both underweight and overweight to be independent risk factors for OS (hazard ratio (HR) 1·22, 95 per cent c.i. 1·19 to 1·56, P = 0·019; and HR 1·57, 1·36 to 1·81, P < 0·001, respectively) and RFS (HR 1·28, 1·16 to 1·53, P = 0·028; and HR 1·34, 1·17 to 1·54, P < 0·001).

Conclusion

Underweight and overweight patients appear to have a worse prognosis than those of normal weight following liver resection for HCC.
Copper(I) Complexes Based on Pentamethylene Sulfide: Luminescence Thermochromism of Cu4I4(C5H10S)4
Authors: Chiang Hojae , Moon Cheol Joo , Kwon Eunjin , Park Hyunjin , Im Hansu , Choi Myong Yong , Kim Tae Ho , Kim Jineun
Published: September 2018

Three copper(I) complexes, [Cu8I8(PMS)4(MeCN)2]
n (1), Cu4I4(PMS)4 (2), and Cu2I2(PMS)4 (3) were prepared by the self‐assembly reaction of mole ratio‐controlled CuI and pentamethylene sulfide (PMS). Single crystal X‐ray diffraction analyses displayed crystal structures of three complexes based on new S‐shaped Cu8I8, cubane Cu4I4, and rhomboid Cu2I2 cluster units for 1–3, respectively. Crystal transformations between 1, 2, and 3 were controlled by the addition of PMS or CuI/acetonitrile. Luminescence properties of 1 and 2 were investigated. Complex 1 showed two very weak emission bands, which were assigned to HE band for λmax = 415 nm and LE band for λmax = 575 nm under ultraviolet irradiation (λex = 355 nm). Complex 2 displayed luminescence thermochromism with a slightly hypsochromic shift from 572 to 565 nm (λex = 355 nm).
Research on the teaching assessment of students of science and engineering teachers in a university
Authors: Deng Shui‐yun , Que Xiang
Published: September 2018

The university pays attention to the quality of teaching and evaluates the results of student assessment as a certain criterion. Teaching quality is the core of education. Improving the quality of teaching is the primary task of school work. This paper studies the results of teaching assessment of university science and technology students, and draws the main content of students' attention to science and engineering courses. It also improves the teaching ability of science and engineering teachers to enhance teaching quality. First, the variance analysis was used to test the influence of different semesters and teachers' professional titles on students' teaching assessment. There was no significant difference in the results; based on the factor analysis, three factors that students pay attention to when evaluating teachers are obtained; the use of association rules to obtain a high degree of correlation between the three factors is a focus of the student's study science and engineering courses. The science and engineering teachers can use this research result to improve and optimize the teaching behavior and enhance their comprehensive classroom teaching ability. Ultimately improve the quality of teaching.
Continuous assessment in a computer programming course supported by a software tool
Authors: Restrepo‐Calle Felipe , Ramírez Echeverry Jhon J. , González Fabio A.
Published: September 2018

This article presents a continuous assessment methodology for a computer programming course supported by an automatic assessment tool, applied to the practical programming exercises performed by the students. The interaction between the students and the assessment tool was studied through quantitative analyses. In particular, the solutions proposed by the students (computer programs) were analyzed using the verdicts given by the automatic assessment tool: correct solutions or incorrect solutions. In the case of incorrect solutions, the types of programming errors were studied. Additionally, interaction was also studied by analyzing the students’ success rate. This rate is the percentage of correct solutions among the total number of attempts (correct and incorrect). Moreover, the relationship between success rate and academic performance was analyzed. Furthermore, this research examines the students’ perceptions toward the assessment tool through interviews. The results of this study help understanding the benefits and perceptions of the students with respect to the use of an automatic assessment tool in a computer programming course.
Active Metabolites from Endolichenic Fungus Talaromyces sp.
Authors: Yuan Wei‐Hua , Teng Meng‐Ting , Sun Shan‐Shan , Ma Lin , Yuan Bo , Ren Qiang , Zhang Peng
Published: September 2018

The active metabolites investigation of Talaromyces sp. (strain No. MH551540) associated with Xanthoparmelia angustiphylla afforded one new δ‐lactone, talaromycin A (1), together with six known compounds, clearanol A (2), 6‐methylbiphenyl‐3,3′,4,5′‐tetraol (3), desmethylaltenusin (4), ergone (5), ergosterol (6), and palmitic acid (7). The structures of these compounds were elucidated by a combination of spectroscopic‐data interpretation and single‐crystal X‐ray diffraction analysis. The cytotoxicities of 1–7 and the antioxidant activities of 3 and 4 were also evaluated.
Electrochemical and Kinetic Insights into Molecular Water Oxidation Catalysts Derived from Cp*Ir(pyridine‐alkoxide) Complexes
Authors: Sackville Emma V. , Marken Frank , Hintermair Ulrich
Published: September 2018

We report the solution‐phase electrochemistry of seven half‐sandwich iridium(III) complexes with varying pyridine‐alkoxide ligands to quantify electronic ligand effects that translate to their activity in catalytic water oxidation. Our results unify some previously reported electrochemical data of Cp*Ir complexes by showing how the solution speciation determines the electrochemical response: cationic complexes show over 1 V higher redox potentials that their neutral forms in a distinct demonstration of charge accumulation effects relevant to water oxidation. Building on previous work that analysed the activation behaviour of our pyalk‐ligated Cp*Ir complexes1–7, we assess their catalytic oxygen evolution activity with sodium periodate (NaIO4) and ceric ammonium nitrate (CAN) in water and aqueoustBuOH solution. Mechanistic studies including H/D kinetic isotope effects and reaction progress kinetic analysis (RPKA) of oxygen evolution point to a dimer‐monomer equilibrium of the IrIVresting state preceding a proton‐coupled electron transfer (PCET) in the turnover‐limiting step (TLS). Finally, true electrochemically driven water oxidation is demonstrated for all catalysts, revealing surprising trends in activity that do not correlate with those obtained using chemical oxidants.
Low Temperature Direct Conversion of Methane using a Solid Superacid
Authors: Kanitkar Swarom , Carter James H. , Hutchings Graham J. , Ding Kunlun , Spivey James J.
Published: September 2018

The direct conversion of methane to higher hydrocarbons and hydrogen can be catalyzed using “superacids”: nCH4→CnHm+xH2. The first report of catalytic oligomerization of methane using superacids was that of Olah et al., who demonstrated the superacidity of FSO3H−SbF5, which is a liquid. More recently, Vasireddy et al. showed that gas‐phase HBr/AlBr3 was an active superacid. The only reported solid superacid for methane oligomerization is sulfated zirconia (SZ). Here, we report a new class of Br‐based solid superacids, AlBrx/H‐ZSM‐5 (“ABZ‐5”, x=1 or 2). ABZ‐5 is based on gas‐phase HBr/AlBr3, with the objective of synthesizing a heterogeneous analogue of the gas‐phase superacid HBr/AlBr3. The results show that ABZ‐5 is significantly more active than SZ. Perhaps more significantly, results here show methane conversions of ∼1 % at 300 °C using ABZ‐5. By comparison with SZ, 350 °C is the lowest temperature reported in the literature at which measurable conversions are shown, and the corresponding methane conversions were <0.15. Here, we demonstrate direct conversion of methane using a solid superacid catalyst, AlBrx/H‐ZSM‐5. This solid catalyst is synthesized using a vapor‐phase process in which AlBr3 vapor is grafted on to solid H‐SZM‐5. This catalyst is characterized using NH3‐TPD, XRD, and DRIFTS. Hydrocarbon products observed in the temperature range of 200–400 °C include both C2–C6 hydrocarbons and aromatics.
Fermentation Titer Optimization and Impact on Energy and Water Consumption during Downstream Processing
Authors: Pothakos Vasileios , Debeer Nadine , Debonne Ignace , Rodriguez Asier , Starr John N. , Anderson Todd
Published: September 2018

A common focus of fermentation process optimization is the product titer. Different strategies to boost fermentation titer target whole‐cell biocatalyst selection, process control, and medium composition. Working at higher product concentrations reduces the water that needs to be removed in the case of aqueous systems and, therefore, lowers the cost of downstream separation and purification. Different approaches to achieve higher titer in fermentation are examined. Energy and water consumption data collected from different Cargill fermentation plants, i.e., ethanol, lactic acid, and 2‐keto‐L‐gulonic acid, confirm that improvements in fermentation titer play a decisive role in downstream economics and environmental footprint.
Common Battery Anode Testing Protocols Are Not Suitable for New Combined Alloying and Conversion Materials
Authors: Bree Gerard , Geaney Hugh , Ryan Kevin M.
Published: September 2018

Here we report an interesting observation on anode materials for lithium ion batteries that undergo combined conversion and alloying lithiation processes during cycling (CAMs). These materials are generating interest as low cost and high capacity alternatives to graphite. We find that common testing protocols (CTPs) are unsuitable for assessment of CAMs due to their distinct multi‐step lithiation characteristics. CTPs involve reporting total gravimetric capacity in a half‐cell configuration alone (opposite Li foil), without individual analysis of each process; energy density and the problems associated with wide discharge voltages are not addressed. Through isolating the individual lithiation processes of a model system (Cu2ZnSnS4), we determine that the conversion processes are highly unstable, whereas the alloying processes exhibit remarkable capacity retention. We demonstrate that inclusion of the conversion processes in cycling actually reduced full cell energy density when compared with alloying alone. This indicates that CTPs may well underestimate the stability of CAMs. It is apparent that the true advantage of CAMs lies in the synergistic combination of the capacity of the alloying portion, and the stability provided by the uncycling Li2S buffer material. Finally, we prescribe a set of testing protocols for a meaningful assessment of new CAMs.
Tuning the Anomeric Effect in Sulfamide with Superacids
Authors: Leitz Dominik , Bayer Marie C. , Morgenstern Yvonne , Zischka Florian , Kornath Andreas J.
Published: September 2018

This study shows that the anomeric effect (negative hyperconjugation) that arises in sulfamide, as a result of the relatively short S−N bonds, can be tuned by the utilization of superacidic media. Sulfamide was reacted in binary superacidic systems XF/MF5 (M=As, Sb; X=H, D) and HF/BF3. The colorless salts formed, [X2NSO2NX3]+[MF6]− and [H2NSO2NH3]+[BF4]− were characterized by low‐temperature vibrational spectroscopy. In the case of [H2NSO2NH3]+[BF4]−, a single crystal X‐ray diffraction study was performed. The salt crystallizes in the monoclinic space group P21/c with four formula units per unit cell. An exclusive N,N′‐diprotonation was observed in the superacidic system HF/SbF5 when using several equivalents of the Lewis acid. Low‐temperature vibrational spectra as well as a single‐crystal X‐ray structure of [H3NSO2NH3]2+2 [SbF6]−⋅2 HF are reported. The salt crystallizes in the orthorhombic space group Pna21 with four formula units per unit cell. Upon mono‐ or diprotonation of sulfamide, remarkable structural changes of the sulfur–nitrogen bond lengths were observed. Herein, these changes are discussed together with quantum chemical calculations.
Variational data assimilation for transient blood flow simulations: Cerebral aneurysms as an illustrative example
Authors: Funke Simon Wolfgang , Nordaas Magne , Evju Øyvind , Alnæs Martin Sandve , Mardal Kent Andre
Published: September 2018

Several cardiovascular diseases are caused from localised abnormal blood flow such as in the case of stenosis or aneurysms. Prevailing theories propose that the development is caused by abnormal wall shear stress in focused areas. Computational fluid mechanics have arisen as a promising tool for a more precise and quantitative analysis, in particular because the anatomy is often readily available even by standard imaging techniques such as magnetic resonance and computed tomography angiography. However, computational fluid mechanics rely on accurate initial and boundary conditions, which are difficult to obtain. In this paper, we address the problem of recovering high‐resolution information from noisy and low‐resolution physical measurements of blood flow (for example, from phase‐contrast magnetic resonance imaging [PC‐MRI]) using variational data assimilation based on a transient Navier‐Stokes model. Numerical experiments are performed in both 3D (2D space and time) and 4D (3D space and time) and with pulsatile flow relevant for physiological flow in cerebral aneurysms. The results demonstrate that, with suitable regularisation, the model accurately reconstructs flow, even in the presence of significant noise.
Task management on fully heterogeneous micro‐server system: Modeling and resolution strategies
Authors: Zaourar Lilia , Ait Aba Massinissa , Briand David , Philippe Jean‐Marc
Published: September 2018

Many of today's important applications of our everyday lives, eg, weather forecast, design of plane and car shapes, medical analysis, or search engine queries depend on massively parallel computer programs executed in data centers. A large amount of energy is used to power them, and it is of primary importance to compute more efficiently to sustain the increasing demand of computing power while keeping energy consumption reasonable. One promising research path in this domain is heterogeneous systems since specific computing resources (processors, accelerators, etc) are more adapted to efficiently execute parts of applications. Nevertheless, the exploitation of these platforms raises new challenges in terms of application management optimization. The aim of our work is to determine effective algorithms to exploit these heterogeneous platforms by finding appropriate application mapping and scheduling to optimize the execution time and energy consumption with respect to various constraints. To achieve this goal, there is a need of a detailed modeling of the applications and the underlying hardware to be able to find realistic solutions. In this paper, we propose such a model, provide two implementations with state‐of‐the‐art tools, and propose a fast greedy online resolution algorithm and preliminary mapping and scheduling numerical results.
Distribution and structure of shallow subterranean aquatic arthropod communities in the parklands of Washington, D.C.
Authors: Keany Jenna , Christman Mary C. , Milton Mikaila , Knee Karen L. , Gilbert Heather , Culver David C.
Published: September 2018

Over 150 sites in the parklands of southeast Washington, D.C., were examined for the presence of inhabitants of seepage springs and associated groundwater habitats—the hypotelminorheic. Three species predominated—the isopod Caecidotea kenki and the amphipods Crangonyx shoemakeri and Stygobromus tenuis sensu lato. C. shoemakeri and Stygobromus rarely occurred together, in part because of different habitat preferences. Based on stepwise logistic regression, Stygobromus preferred cooler water with lower specific conductance, and Crangonyx preferred warmer waters. Seven environmental parameters—temperature, temperature deviation from average, radon, specific conductance, DO, pH, and depth of clay layer—could not distinguish between inhabited and uninhabited sites, suggesting that most sites studied are potential habitats. Nearest neighbour analysis of Stygobromus sites showed them to be significantly farther apart than either Caecidotea or Crangonyx sites, suggesting that they are limited in dispersal ability. Overall, all three species appear to form meta‐populations, and so the protection of all sites, not just currently occupied sites, is important.
Unnatural hypoxic regimes
Authors: Jager Henriette I. , Novello Rebecca C. , Dale Virginia H. , Villnas Anna , Rose Kenneth A.
Published: September 2018

Coastal hypoxia is increasing worldwide in response to human‐caused changes in global climate and biogeochemical cycles. In this paper, we view anthropogenic trends in coastal hypoxia through the lens of disturbance ecology and complexity theory. Complexity theory provides a framework for describing how estuaries and other coastal aquatic ecosystems respond to hypoxia by understanding feedback loops. Can it also be valuable in understanding how these ecosystems behave under shifting (i.e., unnatural) disturbance regimes? When viewed as a disturbance regime, shifts in the spatial (areal extent and fragmentation) and temporal (frequency and duration of events) characteristics of coastal hypoxia can be used to track changes into a non‐stationary future. Here, we consider options for increasing the resilience of coastal aquatic ecosystems to future, unnatural hypoxic regimes. To start, we define desirable states as ecosystems with long trophic chains and slow nutrient and carbon dynamics that produce many ecosystem services. We then work backward to describe circumstances dominated by positive feedbacks that can lead ecosystems toward an undesirable state (i.e., depauperate communities and chemically reduced sediments). Processes of degradation and recovery can be understood in the context of island biogeography whereby species diversity in habitats fragmented by hypoxia is determined by the balance between rapid local extinction, slow recolonization from the edges of hypoxic patches, and opportunities for ecological succession during between disturbance events. We review potential future changes associated with changing global climate and highlight ways to enhance coastal resilience. In addition to efforts to slow climate change, potential interventions include reduced nutrient and carbon loadings from rivers, restoration of aquatic vegetation, and managing for key species, including those that promote sediment oxygenation, that enhance water clarity, or that promote grazing on epiphytic algae through top‐down control.
An improved input energy spectrum verified by the shake table tests
Authors: Güllü Ahmet , Yüksel Ercan , Yalçın Cem , Anıl Dindar A. , Özkaynak Hasan , Büyüköztürk Oral
Published: September 2018

Input energy is the principal component of the energy balance equation. It is beneficial to determine, through its components, how the recoverable and irrecoverable energies are distributed within the structural elements. Several equations and attenuation relations to define mass‐normalized input energy spectra exist in the literature. They are mainly proposed for elastic systems subjected to far‐fault EQs. There is a lack of experimental verification of these proposed spectra. In this paper, experimental assessment was performed to the existing spectra, and further improvements were accomplished. For this purpose, steel cantilever columns were tested on the shake table for two specific historical EQs coincidently having similar spectral acceleration values. Based on the experimental results, a three‐part mass‐normalized relative input energy spectrum was formulated including soil type, EQ (corner period, intensity, duration, spectral acceleration, and velocity), and structural behavioral characteristics (period and structural damping). The proposed input energy spectrum was experimentally calibrated and numerically validated for various EQs featuring near‐ and far‐field types. Analytical and experimental comparisons were made between the previously developed spectrum and the newly proposed one. The validation studies and the statistical evaluations exposed that the proposed spectrum yielded better agreement with the experimental and numerical results.
A Comparison of the chemical sensitivities between in vitro and in vivo propagated juvenile freshwater mussels: Implications for standard toxicity testing
Authors: Popp Anakela , Cope W. Gregory , McGregor Monte A. , Kwak Thomas J. , Augspurger Tom , Levine Jay F. , Koch Leroy
Published: September 2018

Unionid mussels are ecologically important and are globally imperiled. Toxicants contribute to mussel declines, and toxicity tests using juvenile mussels—a sensitive life stage—are valuable in determining thresholds used to set water quality criteria. In vitro culture methods provide an efficient way to propagate juveniles for toxicity testing, but their relative chemical sensitivity compared with in vivo propagated juveniles is unknown. Current testing guidelines caution against using in vitro cultured juveniles until this sensitivity is described. Our objective was to evaluate the relative sensitivity of juvenile mussels produced from both in vitro and in vivo propagation methods to selected chemicals. We conducted 96-h acute toxicity tests according to ASTM International guidelines with 3 mussel species and 6 toxicants: chloride, nickel, ammonia, and 3 copper-based compounds. Statistically significant differences between in vitro and in vivo juvenile 96-h median effect concentrations were observed in 8 of 17 tests, and in vitro juveniles were more sensitive in 6 of the 8 significant differences. At 96 h, 4 of the 8 statistically different tests for a given chemical were within a factor of 2, which is the intralaboratory variation demonstrated in a recent evaluation of mussel toxicity tests. We found that although differences in chemical sensitivity exist between in vitro and in vivo propagated juvenile mussels, they are within normal toxicity test variation. Therefore, in vitro propagated juvenile mussels may be appropriate for use in ASTM International-based toxicity testing. Environ Toxicol Chem 2018;37:3077–3085. © 2018 SETAC
Technical efficiency of Portuguese public hospitals: A comparative analysis across the five regions of Portugal
Authors: Ferreira Diogo Cunha , Nunes Alexandre Morais
Published: September 2018

The present study aims to analyse the efficiency scores of hospital units, with reference to the five Portuguese health administrative regions (North, Centre, Lisbon and Tagus Valley, Alentejo, and Algarve). This paper contextualizes the process of decentralization of health in Portugal (started 1993) as well as the hospitals' corporatization and merging reforms (started 2002). These reforms aimed to meet health care needs by optimizing costs, improving efficiency, and broadening both access and quality in health services. Data envelopment analysis was used to quantify and compare the efficiencies of 27 hospitals heterogeneously distributed by five administrative regions. The results show a large average performance across the country. However, there are regions with scores larger than the national average and others with inferior results. This interregional diversity points towards disparities that deserve special attention from the policymakers and hospital managers.
Reciprocity matters: Idiosyncratic deals to shape the psychological contract and foster employee engagement in times of austerity
Authors: Davis Amanda S. , Van der Heijden Beatrice I. J. M.
Published: September 2018

Following the 2007/2008 global financial crisis, the UK public sector has experienced major funding cuts resulting in staffing reductions and a dilution in the employment deal. Consequently, the aim of this study is to understand how i‐deals, which are unique conditions of employment negotiated between an individual and their employer (Rousseau, 2005), may be used to accept a new psychological contract and foster employee engagement during austerity. Four qualitative team case studies were conducted comprising senior, middle‐line, and first‐line managers, and either professional or nonprofessional employees, within one English local authority (LA). Methods included 29 × one‐to‐one and three focus group semistructured interviews incorporating the critical incident technique. By examining i‐deals through the lens of social exchange theory (Blau, 1964), this research demonstrates the role of reciprocity in the form of i‐deals to accept the new psychological contract and foster engagement. Here, for some employees, once concrete and universal resources were available to a certain level (e.g., pay), the difference (e.g., universal resources such as a pay rise, external training) was substituted by more particularistic resources (e.g., flexibility and developmental i‐deals) herewith extending Foa and Foa's (1976, 1980, and 2012) resource theory. Furthermore, resultant economic or social exchange may be due to the individual attribution of why the i‐deal was agreed, rather than the i‐deal content. Finally, when i‐deals are denied, action to lower the risk of psychological contract breach is advised.
A novel method for continuous formation of cord‐like collagen gels to fabricate durable fibers in which collagen fibrils are longitudinally aligned
Authors: Yunoki Shunji , Hatayama Hirosuke , Ebisawa Mizue , Kondo Eiji , Yasuda Kazunori
Published: September 2018

We developed a continuous formation method of cord‐like collagen gels comprising fibrils preferentially aligned along the geometrical axes (CCGs). Collagen (2.5%) dissolved in a sodium phosphate buffer containing 280 mM of sodium chloride was introduced into a stainless cylinder (length 52 mm, diameter 2.0 mm) warmed at 38°C at a linear velocity of 2.5 mm/s. This process caused collagen fibril alignments under acute fibril formation in the cylinder, resulting in continuous formation of CCGs. Fibril formation rate, shear rate, and shear duration were substantial factors for successful CCG formation. Outstanding advantages of this method over conventional wet spinning include the capacity of this technique to form aligned fibrils in the entire gels and to control the diameter of cord‐like gels over 1 mm. The air‐drying of CCGs which were crosslinked with 1‐ethyl‐3‐(3‐dimethylaminopropyl)‐carbodiimide and N‐hydroxy‐succinimide produced dry collagen fibers with cross‐sectional areas of 0.0123–0.135 mm2. Upon the rewetting of the fibers, they failed at a stress of 54.5 ± 7.8 MPa, which is higher than the mean failure stress of anterior cruciate ligament tissue (13.3–37.8 MPa). These findings indicate that the CCG formation method enables the fabrication of collagen fibers which are potential components of collagen‐based artificial tendons. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1011–1023, 2019.
Evaluation of dehydrated human umbilical cord biological properties for wound care and soft tissue healing
Authors: Bullard Jenn D. , Lei Jennifer , Lim Jeremy J. , Massee Michelle , Fallon Anna M. , Koob Thomas J.
Published: September 2018

Chronic wounds are a significant health care problem with serious implications for quality of life because they do not properly heal and often require therapeutic intervention. Amniotic membrane allografts have been successfully used as a biologic therapy to promote soft tissue healing; however, the umbilical cord, another placental‐derived tissue, has also recently garnered interest because of its unique composition but similar placental tissue origin. The aim of this study was to characterize PURION® PLUS Processed dehydrated human umbilical cord (dHUC) and evaluate the biological properties of this tissue that contribute to healing. This was performed through the characterization of the tissue composition, evaluation of in vitro cellular response to dHUC treatment, and in vivo bioresorption and tissue response in a rat model. It was observed that dHUC contains collagen I, hyaluronic acid, laminin, and fibronectin. Additionally, 461 proteins that consist of growth factors and cytokines, inflammatory modulators, chemokines, proteases and inhibitors, adhesion molecules, signaling receptors, membrane‐bound proteins, and other soluble regulators were detected. Cell‐based assays demonstrated an increase in adipose‐derived stem cell and mesenchymal stem cell proliferation, fibroblast migration and endothelial progenitor cell vessel formation in a dose‐dependent manner after dHUC treatment. Lastly, rat subcutaneous implantation demonstrated biocompatibility since dHUC allografts were resorbed without fibrous encapsulation. These findings establish that dHUC possesses biological properties that stimulate cellular responses important for soft tissue healing. © 2018 The Authors. Journal Of Biomedical Materials Research Part B: Applied Biomaterials Published By Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1035‐1046, 2019.
Motives and Consequences of White Knight Takeovers
Authors: Chen Xing , Ullah Saif
Published: September 2018

Previous studies have shown that shareholders of acquiring firms experience negative returns during takeover contests. Our investigation of white knights confirms these results using both short‐term and long‐term abnormal returns around such contests. Our results suggest that white knight bidders experience performance similar to other friendly bidders after making a bid. However, we find no significant effect of financial strength and ownership structure on the likelihood of a white knight takeover attempt. Instead, we find that having a classified board is an important determinant in predicting whether a firm will make a bid as a white knight. We find that white knight bidders are more likely to succeed as they offer a higher transaction value to target firms' shareholders.