bluuebunny/crossref_metadata_2025 huggingface dataset:
How do we ensure the future of our discipline is vibrant? Student reflections on careers and culture of ecology
Authors: Hansen Winslow D. , Scholl Joshua P. , Sorensen Amanda E. , Fisher Kelsey E. , Klassen Jessica A. , Calle Leonardo , Kandlikar Gaurav S. , Kortessis Nicholas , Kucera Dion C. , Marias Danielle E. , Narango Desiree L. , O'Keeffe Kayleigh , Recart Wilnelia , Ridolfi Elizabeth , Shea Monika E.
Published: February 2018

Ecology must attract and retain diverse talented people to produce innovative research and relevant solutions to 21st‐century environmental problems. Careers and culture form the foundation of scientific advancement, and substantial progress has been made over recent decades in both realms. Yet, important challenges persist in expanding career paths, inclusion of underrepresented groups, and communication with the public. The ESA Student Section organized a horizon scanning exercise to address the following goals: (1) to identify challenges that 21st‐century ecologists contend with or expect to contend with in careers and outreach to society, (2) to anticipate opportunities to help ecologists meet challenges, and (3) to identify concrete steps that could be taken by individual laboratories, institutions, and the ESA to foster progress. In spring 2016, the ESA Student Section solicited input from student members and organized a working group to assess the state of the discipline and to envision how we might cultivate a more inclusive and effective community. We identified three major challenges. First, PhDs are produced faster than academic positions become available and disconnects between academia and other sectors may keep early‐career ecologists from realizing the breadth of available positions. We propose an online jobs hub to make non‐academic sectors more accessible to ecologists. We also suggest students develop skills portfolios to prepare for non‐academic positions. Second, the composition of people who are ecologists differs from broader society, partially due to implicit biases and institutional barriers. We propose steps to reduce attrition of diversity in ecology that include countering implicit biases and creating mentorship networks. We offer steps to improve recruitment by increasing awareness of ecology among high school students and undergraduates and providing opportunities to engage in ecological research. Finally, ecology is only relevant if the public perceives it to be. We must improve science communication and begin cultivating trust. We propose that ad hoc communication by all ecologists is insufficient; translational ecologists should be hired in every department and formal training in translational ecology is necessary. We hope this paper catalyzes critical thinking and partnerships among students, professional ecologists, and the ESA to ensure the future of ecology is vibrant.
How robust are popular beta diversity indices to sampling error?
Authors: Schroeder P. Jason , Jenkins David G.
Published: February 2018

Beta diversity (β) is used in biogeography, ecology, and conservation to assess the heterogeneity of local communities. Ideally, researchers could include sensitivity to error in the list of reasons to choose a β index. However, only numerical undersampling has been rigorously studied. This study compared multiple β indices to determine which are most robust to geographic undersampling, numerical undersampling, and taxonomic error using simulated landscapes. For these landscapes, eight β indices were chosen to represent families of β and used to measure real and errant data. Six indices used both presence–absence and abundance data, while two more used only abundance data. Six of the abundance‐based indices had adjusted versions for individual undersampling, and these versions were also evaluated (total = 14 indices). Presence–absence‐ and abundance‐based indices were comparable in sensitivity to total method error. Numerical undersampling and taxonomic error generally caused more error in β than randomly distributed geographic undersampling. Among presence–absence‐based indices, Jaccard's dissimilarity was the most robust to error overall, while β‐3 was the most robust among narrow‐sense measures. Among abundance‐based indices, Bray‐Curtis and BDTOTAL were the most robust to error. Some commonly used β indices (e.g., Sorensen, Simpson) are relatively unreliable given errors of taxonomy or numerical undersampling. Future studies of β should focus on using more robust indices (Jaccard, Bray‐Curtis, BDTOTAL), and past studies based on error‐sensitive indices should be considered with caution. Studies of β should emphasize adequate numerical sampling and taxonomic accuracy to minimize errors in β.
Fluvial network topology shapes communities of native and non‐native amphipods
Authors: Alther Roman , Altermatt Florian
Published: February 2018

Habitat connectivity crucially influences dispersal of organisms. It is especially seen as an important driver of the spatial structuring of biological communities in ecosystems that have intrinsic and general connectivity patterns, such as the universal dendritic structure of fluvial networks. These networks not only define dispersal of native species, but also represent corridors of biological invasions, making understanding network topology effects on invasion dynamics and subsequent diversity patterns of high interest. We studied amphipod community diversity and structure in the upper 27,882‐km2 drainage basin of the river Rhine in Central Europe, focusing on differences between native and non‐native species. Overall, species richness increased along the network from headwaters to the outlet nodes. We found, however, contrasting patterns of native and non‐native amphipod richness along the network, with headwater nodes representing refugia for native species and more downstream nodes being hotspots of biological invasions. Importantly, while species turnover (β‐diversity) of native species increased with distance between nodes in the network, this was not the case for non‐native species, indicating a much lower dispersal limitation of the latter. Finally, the overall amphipod community structure closely mirrored the topological modularity of the network, highlighting the network's imprint on community structure. Our results underpin the importance of connectivity for community formation and the significance of rivers for biological invasions and suggest that empirically observed matches of diversity patterns in rivers predicted by null models are the long‐term outcome of species invasions and species sorting.
The influence of smoking, age and stage at diagnosis on the survival after larynx, hypopharynx and oral cavity cancers in Europe: The ARCAGE study
Authors: Abrahão Renata , Anantharaman Devasena , Gaborieau Valérie , Abedi‐Ardekani Behnoush , Lagiou Pagona , Lagiou Areti , Ahrens Wolfgang , Holcatova Ivana , Betka Jaroslav , Merletti Franco , Richiardi Lorenzo , Kjaerheim Kristina , Serraino Diego , Polesel Jerry , Simonato Lorenzo , Alemany Laia , Agudo Trigueros Antonio , Macfarlane Tatiana V. , Macfarlane Gary J. , Znaor Ariana , Robinson Max , Canova Cristina , Conway David I. , Wright Sylvia , Healy Claire M. , Toner Mary , Cadoni Gabriella , Boccia Stefania , Gheit Tarik , Tommasino Massimo , Scelo Ghislaine , Brennan Paul
Published: February 2018

Head and neck cancer (HNC) is a preventable malignancy that continues to cause substantial morbidity and mortality worldwide. Using data from the ARCAGE and Rome studies, we investigated the main predictors of survival after larynx, hypopharynx and oral cavity (OC) cancers. We used the Kaplan–Meier method to estimate overall survival, and Cox proportional models to examine the relationship between survival and sociodemographic and clinical characteristics. 604 larynx, 146 hypopharynx and 460 OC cancer cases were included in this study. Over a median follow‐up time of 4.6 years, nearly 50% (n = 586) of patients died. Five‐year survival was 65% for larynx, 55% for OC and 35% for hypopharynx cancers. In a multivariable analysis, we observed an increased mortality risk among older (≥71 years) versus younger (≤50 years) patients with larynx/hypopharynx combined (LH) and OC cancers [HR = 1.61, 95% CI 1.09–2.38 (LH) and HR = 2.12, 95% CI 1.35–3.33 (OC)], current versus never smokers [HR = 2.67, 95% CI 1.40–5.08 (LH) and HR = 2.16, 95% CI 1.32–3.54 (OC)] and advanced versus early stage disease at diagnosis [IV versus I, HR = 2.60, 95% CI 1.78–3.79 (LH) and HR = 3.17, 95% CI 2.05–4.89 (OC)]. Survival was not associated with sex, alcohol consumption, education, oral health, p16 expression, presence of HPV infection or body mass index 2 years before cancer diagnosis. Despite advances in diagnosis and therapeutic modalities, survival after HNC remains low in Europe. In addition to the recognized prognostic effect of stage at diagnosis, smoking history and older age at diagnosis are important prognostic indicators for HNC.
Behavior of new hydroxyapatite/glucan composite in human serum
Authors: Borkowski Leszek , Lübek Tomasz , Jojczuk Mariusz , Nogalski Adam , Belcarz Anna , Palka Krzysztof , Hajnos Mieczysław , Ginalska Grazyna
Published: February 2018

Biomaterials for bone tissue regeneration, including polymer‐based composites, are typically evaluated in vitro prior to the clinical trials. However, such composites tested in vivo may behave different due to the specific body conditions. For example, some composites implanted into the tissue acidified due to transient postoperative inflammation may unexpectedly swell which delays the wound healing. Such massive swelling in acidic medium was previously observed for new elastic hydroxyapatite (HAp)/β‐glucan biomaterial. However, in further clinical cases concerning the composite implantation in patients without significant inflammation indicators, no side effects were observed. Therefore, it was reasonable to test the effect of human serum of neutral pH (typical for noninflamed tissues) on the composite parameters, in particular volume changes. Thus, this article shows the characterization of physicochemical parameters of the composite after incubation (5 days) in human serum of neutral pH by means of weight and volume measurement, scanning electron microscopy, X‐ray diffraction, Fourier‐transform infrared spectroscopy, microcomputed tomography, mercury intrusion, and biochemical techniques. Results showed that human serum collected from healthy people caused no uncontrolled changes in weight and volume, porosity and mechanical properties of the composite. Therefore, this suggests the lack of volume change‐related side effects of HAp/glucan composite in bone defects treatment if postoperative inflammation is prevented. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2653–2664, 2018.
The width of quadrangulations of the projective plane
Authors: Esperet Louis , Stehlík Matěj
Published: February 2018

We show that every 4‐chromatic graph on n vertices, with no two vertex‐disjoint odd cycles, has an odd cycle of length at most . Let G be a nonbipartite quadrangulation of the projective plane on n vertices. Our result immediately implies that G has edge‐width at most , which is sharp for infinitely many values of n. We also show that G has face‐width (equivalently, contains an odd cycle transversal of cardinality) at most , which is a constant away from the optimal; we prove a lower bound of . Finally, we show that G has an odd cycle transversal of size at most inducing a single edge, where Δ is the maximum degree. This last result partially answers a question of Nakamoto and Ozeki.
Teleconnections between ENSO and rainfall and drought in Puerto Rico
Authors: Torres‐Valcárcel Angel R.
Published: February 2018

An analytical study was conducted to assess the long‐term influence, role, and impacts of El Niño‐Southern Oscillation (ENSO) on Puerto Rico's precipitation patterns and significant moisture deficits (droughts). Detection and attribution was addressed by evaluating local rainfall measures and ENSO‐related data to (1) detect ENSO signals and patterns, (2) quantify the magnitude of any impacts, and (3) determine if ENSO may be an important factor for local prediction of future droughts. Data were evaluated at different time periods and two spatial scales (island‐wide and internal climate regions of Puerto Rico). Although a signal was detected, it was weak, in both directions, varied regionally, and has inconsequential impacts. No evidence was found for a major control by ENSO over local monthly, seasonal, and yearly rainfall for any climate regions on the island. These results indicate that ENSO is not a main factor causing droughts in Puerto Rico for the study period and thus should not be a factor in predicting the potential for local dry periods or large precipitation deficits in the future. Any presumed teleconnections between Puerto Rico's dry periods and ENSO are not based on current climatological evidence. Thus, local drought prediction efforts should be focused on finding major causes of local rainfall variation other than ENSO.
Seasonal variability of the vitamin C content of fresh fruits and vegetables in a local retail market
Authors: Phillips Katherine M , Tarrago‐Trani Maria Teresa , McGinty Ryan C , Rasor Amy S , Haytowitz David B , Pehrsson Pamela R
Published: February 2018

BACKGROUND

Seasonal variation of vitamin C in fresh fruits and vegetables is not reflected in food composition database average values, yet many factors influence content and retention.

RESULTS

Fresh fruits and vegetables were sampled on three occasions in each season, from the same local retail outlets, for 1 or 2 years. Vitamin C was significantly higher in winter‐sampled spinach (436 mg kg−1) compared with spring (298 mg kg−1) and summer/fall (180 mg kg−1); in potatoes in summer/fall (156 mg kg−1) versus winter/spring (106 mg kg−1); and in oranges in winter (616 mg kg−1), spring (592 mg kg−1), and summer (506 mg kg−1). Ranges were dramatic among sampling occasions for broccoli, oranges, potatoes, and spinach (700–1210 mg kg−1, 420–780 mg kg−1, 70–280 mg kg−1, and 90–660 mg kg−1 respectively). Mean values for apples, bananas, tomatoes, and potatoes differed from the USDA National Nutrient Database for Standard Reference (SR) average by ≥10% of the daily recommended intake (90 mg). For broccoli, oranges, and spinach, vitamin C was substantially above or below the SR range in 50–100% of the samples. For spinach, the average content did not differ from SR, but vitamin C in winter was 55% higher than SR.

CONCLUSION

Database average values for vitamin C in fresh produce can significantly over‐ or underestimate the content in a specific food supply. © 2018 Society of Chemical Industry
Near‐infrared spectroscopy‐based analysis to study sensory parameters on pork loins as affected by cooking methods and conditions
Authors: González‐Mohino Alberto , Antequera Teresa , Ventanas Sonia , Caballero Daniel , Mir‐Bel Jorge , Pérez‐Palacios Trinidad
Published: February 2018

BACKGROUND

The main objectives of this study were to evaluate the use of near infrared spectroscopy (NIRS) to classify pork loins under different methods and cooking conditions, and to predict sensory attributes of this product.

RESULTS

Samples were oven cooked at two temperatures (150 and 180 °C) for different times (45, 60 and 75 min) and confit cooked for different times (120, 180 and 240 min). All cooked loin samples were subjected to a Quantitative Descriptive Analysis by a trained panel. For classification, principal component analysis was performed based on the NIRS database, showing a good discrimination between loins samples subjected to different cooking conditions. Regarding prediction, a data mining technique (multiple linear regression) was applied on a database constructed with data from NIRS and sensory analysis.

CONCLUSION

The correlation coefficient and the mean absolute error obtained suggest that the calculated prediction equations of this study are valid to predict the changes in the sensory attributes depending on the cooking method and conditions used for pork loins. © 2018 Society of Chemical Industry
Prognostic factors for resected non‐small cell lung cancer in patients with type 2 diabetes mellitus
Authors: Yu Woo Sik , Lee Chang Young , Park Seong Yong , Suh Jee Won , Narm Kyoung Shik , Kim Dae Joon , Chung Kyung Young , Lee Jin Gu
Published: February 2018

Background

For diabetic patients with lung cancer, blood glucose levels and medications such as metformin and statins may influence survival.

Objectives

This study aimed to determine prognostic survival factors for diabetic patients with resected non‐small cell lung cancer.

Patients and Methods

Between January 2005 and December 2013, 301 patients with type 2 diabetes mellitus who underwent curative resection for non‐small cell lung cancer were identified and reviewed retrospectively.

Results

The median follow‐up period was 48 months. In multivariate analysis for lung cancer‐specific survival, older age, forced expiratory volume in 1 s (FEV1) <80% predicted, and advanced pathologic stage were significant negative prognostic factors; statin use was a positive prognostic factor (hazard ratio (HR), 0.468). In multivariate analysis for overall survival, male sex, older age, comorbidity index, and advanced pathologic stage were significant negative prognostic factors and proper glycemic control (HR, 0.621) and statin use (HR, 0.585) were positive prognostic factors.

Conclusions

Proper glycemic control (glycated hemoglobin A1c <7%) is recommended for diabetic patients undergoing lung cancer operations. Further studies are required to elucidate associations between type 2 diabetes mellitus and antineoplastic effects of statins and to evaluate statins as a novel adjuvant treatment for lung cancer.
Deep Generative Models for Molecular Science
Authors: Jørgensen Peter B. , Schmidt Mikkel N. , Winther Ole
Published: February 2018

Generative deep machine learning models now rival traditional quantum‐mechanical computations in predicting properties of new structures, and they come with a significantly lower computational cost, opening new avenues in computational molecular science. In the last few years, a variety of deep generative models have been proposed for modeling molecules, which differ in both their model structure and choice of input features. We review these recent advances within deep generative models for predicting molecular properties, with particular focus on models based on the probabilistic autoencoder (or variational autoencoder, VAE) approach in which the molecular structure is embedded in a latent vector space from which its properties can be predicted and its structure can be restored.
Cucurbitane Triterpenoids from the Fruits of Momordica Charantia Improve Insulin Sensitivity and Glucose Homeostasis in Streptozotocin‐Induced Diabetic Mice
Authors: Han Joo‐Hui , Tuan Nguyen Quoc , Park Min‐Ho , Quan Khong Trong , Oh Joonseok , Heo Kyung‐Sun , Na MinKyun , Myung Chang‐Seon
Published: February 2018

Scope

Momordica charantia (M. charantia) has antidiabetic effects, and cucurbitane‐type triterpenoid is one of the compounds of M. charantia. This study aims to investigate whether the new cucurbitane‐type triterpenoids affect insulin sensitivity both in vitro and in vivo, and the underlying mechanisms.

Methods and results

Four compounds (C1–C4) isolated from the ethanol extract of M. charantia enhance glucose uptake in C2C12 myotubes via insulin receptor substrate‐1 (IRS‐1) rather than via adenosine monophosphate‐activated protein kinase. The most potent, compound 2 (C2), significantly increases the activation of IRS‐1 and downstream signaling pathways, resulting in glucose transporter 4 translocation. Furthermore, these C2‐induced in vitro effects are blocked by specific signal inhibitors. We further evaluate the antidiabetic effect of C2 using a streptozotocin (STZ)‐induced diabetic mouse model. Consistent with in vitro data, treatment with C2 (1.68 mg kg–1) significantly decreases blood glucose level and enhances glycogen storage in STZ‐injected mice. These effects appear to be mediated by the IRS‐1 signaling pathway in skeletal muscle, not in adipose and liver tissues, suggesting that C2 improves hyperglycemia by increasing glucose uptake into skeletal muscle.

Conclusion

Our findings demonstrate that the new cucurbitane‐type triterpenoids have potential for prevention and management of diabetes by improving insulin sensitivity and glucose homeostasis.
Condition monitoring technique of rotating machinery using K‐band Doppler radar
Authors: Im Yun‐Taek
Published: February 2018

A condition monitoring technique using Doppler radar is proposed for rotating machinery. An analysis of the fundamental and harmonic signals is based on the Bessel functions. To measure the vibration signals, a compact K‐band (24.125 GHz) CW radar module is used, and an experiment was carried out to observe the spectral response of a motor at 1190 RPM, where the measurement direction is horizontal. From the spectral responses, the fundamental frequency, or harmonics, is related to the RPM of the rotating machinery. The proposed Doppler radar is the simplest radar, and therefore the condition monitoring system can be easily implemented in a low cost way. In addition, the radar is less sensitive to scattering because the wavelength is much shorter than the wavelength of the LDV, and thus this behavior is suitable for an outdoor installation of the condition monitoring system.
Active balun using resistive feedback for low gain imbalance
Authors: Choi Yeong Seok , Jin Ho Jeong , Cho Choon Sik , Kim Young‐Jin
Published: February 2018

An active balun using current steering topology is presented for phase and amplitude corrections. The proposed active balun is constructed with two different unit balun structures based on resistive feedback to reduce phase and amplitude errors. The first unit balun composed of the common source configuration provides a main transconductance stage for the proposed active balun. The second unit balun using common source and common gate configurations works for phase and gain error reduction. The resistive feedback proposed here leads to mitigation of phase error and then amplitude error, and an equation for deciding the feedback resistance is successfully deduced. The value of a feedback resistor is determined to provide the least phase and amplitude errors by optimizing the derived design equation. Designed and fabricated active balun in 65 nm CMOS process operates over 1.0–1.2 GHz band, showing input and output reflection coefficients under –10 dB, phase error under 3.5° and gain error under 1.4 dB over the frequency of interest. Moreover, the gain is measured to be 4 dB maximum and power consumption of 2.6 mW is measured.
Vehicle routing problems with road‐network information: State of the art
Authors: Ben Ticha Hamza , Absi Nabil , Feillet Dominique , Quilliot Alain
Published: February 2018

Vehicle routing problems have drawn researchers’ attention for more than 50 years. Most approaches found in the literature address these problems using the so‐called customer‐based graph, a complete graph representing the road network, where a node is introduced for every point of interest (eg, customers, depot…) and an arc represents the best path between two points. In many situations, this representation induces negative effects on the solution quality or efficiency. A growing number of works in the literature investigate these issues and propose modeling taking account of more detailed information from the road‐network. In this article, we review these works and classify them with respect to the type of negative effects provoked by the customer‐based graph.
Dietary Curcumin Intervention Targets Mouse White Adipose Tissue Inflammation and Brown Adipose Tissue UCP1 Expression
Authors: Song Zhuolun , Revelo Xavier , Shao Weijuan , Tian Lili , Zeng Kejing , Lei Helena , Sun Hong‐Shuo , Woo Minna , Winer Daniel , Jin Tianru
Published: February 2018

Objective

This study aimed to determine whether dietary curcumin intervention targets both white adipose tissue (WAT) inflammation and brown adipose tissue (BAT)‐mediated energy expenditure.

Methods

C57BL/6J mice were fed with a low‐fat diet, high‐fat diet (HFD), or HFD plus curcumin. In addition to assessing the effect of curcumin intervention on metabolic profiles, this study assessed WAT macrophage infiltration and composition and inflammatory cytokine production. Metabolic cages were applied for determining energy expenditure. Raw264.7 (ATCC, Manassas, Virginia) and other cell models were utilized to test the in vitro effect of curcumin treatment.

Results

Curcumin intervention reduced WAT macrophage infiltration and altered macrophage functional polarity, as the ratio of M2‐like versus M1‐like macrophages increased after curcumin intervention. Curcumin treatment reduced M1‐like macrophage markers or proinflammation cytokine expression in both macrophages and adipocytes. Curcumin intervention also increased energy expenditure and body temperature in response to a cold challenge. Finally, the in vivo and in vitro investigations suggested that curcumin increased expression of uncoupling protein 1 (UCP1), possibly involving PPAR‐dependent and ‐independent mechanisms.

Conclusions

Curcumin intervention targets both WAT inflammation and BAT UCP1 expression. These observations advanced our knowledge on the metabolic beneficial effects of the curry compound curcumin, bringing us a novel perspective on dietary polyphenol research.
Comparison of Secretome Profile of Pathogenic and Non‐Pathogenic Entamoeba histolytica
Authors: Ahn Chun‐Seob , Kim Jeong‐Geun , Shin Myeong Heon , Lee Young Ah , Kong Yoon
Published: February 2018

The obligatory intracellular protozoan parasite Entamoeba histolytica causes amebic dysentery and liver abscess. E. histolytica adheres to the host tissues in a contact‐dependent manner. E. histolytica excretory–secretory products (ESP) might play critical roles during invasion. We comparatively analyzed the secretome profile of E. histolytica pathogenic HM‐1:IMSS and non‐pathogenic Rahman strains. The two ESP revealed similar but distinct spotting patterns. In both ESP, alcohol dehydrogenase, enolase 1, and transketolase, which control classical carbohydrate metabolism and other moonlighting effects, constituted the most abundant fractions. We recognized differently secreted molecules. Secretion of cytoskeletal organization proteins (actin, actin binding protein, and EHI_068510), protein remodeling amino peptidase, and multifunctional elongation factor 1‐α were increased in Rahman. Conversely, carbohydrate metabolizing enolase 1, alcohol dehydrogenase, transketolase, calponin, phosphoglucose mutase, malic enzyme and EHI_156420, xenobiotic scavenging superoxide dismutase and EHI_140740, and pyruvate:ferredoxin oxidoreductase and coronin (carbohydrate metabolism/detoxification) showed reduced secretion. Transcription levels of some genes involved in these processes also decreased. Changes of secretory behavior, especially decreased secretion of multifunctional carbohydrate metabolizing enzymes and detoxifying proteins that importantly participated in amoeba pathogenesis might reflect avirulent nature of Rahman strain in the host.
Gold‐Cluster‐Based Dual‐Emission Nanocomposite Film as Ratiometric Fluorescent Sensing Paper for Specific Metal Ion
Authors: Song Shanliang , Wang Chuanxi , Zhao Yue , Hu Tantan , Zhou Xinxin , Zhao Tianxin , Yang Minghui , Lin Quan
Published: February 2018

A dual‐emission ratiometric fluorescent sensing film for metal ion detection is designed. This dual‐emission film is successfully prepared from chitosan, graphitic carbon nitride (g‐C3N4), and gold nanoclusters (Au NCs). Here, it is shown that the g‐C3N4 not only serves as the fluorescence emission source, but also enhances the mechanical and thermal stability of the film. Meanwhile, the Au NCs are adsorbed on the surface of chitosan film by the electrostatic interaction. The as‐prepared dual‐emission film can selectively detect Cu2+, leading to the quench of red fluorescence of Au NCs, whereas the blue fluorescence from g‐C3N4 persists. The ratio of the two fluorescence intensities depends on the Cu2+ concentration and the fluorescence color changes from orange red to yellow, cyan, and finally to blue with increasing Cu2+ concentration. Thus, the as‐prepared dual‐emission film can be worked as ratiometric sensing paper for Cu2+ detection. Furthermore, the film shows high sensitivity and selectivity, with low limit of detection (LOD) (10 ppb). It is observed that this novel gold‐cluster‐based dual‐emission ratiometric fluorescent sensing paper is an easy and convenient way for detecting metal ions. It is believed that this research work have created another avenue for the detection of metal ions in the environment.
Flow‐volume loops measured with electrical impedance tomography in pediatric patients with asthma
Authors: Ngo Chuong , Dippel Falk , Tenbrock Klaus , Leonhardt Steffen , Lehmann Sylvia
Published: February 2018

Background

Electrical impedance tomography (EIT) provides information on global and regional ventilation during tidal breathing and mechanical ventilation. During forced expiration maneuvers, the linearity of EIT and spirometric data has been documented in healthy persons. The present study investigates the potential diagnostic use of EIT in pediatric patients with asthma.

Methods

EIT and spirometry were performed in 58 children with asthma (average age ± SD: 11.86 ± 3.13 years), and 58 healthy controls (average age ± SD: 12.12 ± 2.9 years). The correlation between EIT data and simultaneously acquired spirometric data were tested for FEV1, FEV0.5, MEF75, MEF50, and MEF25. Binary classification tests were performed for the EIT‐derived Tiffeneau index FEV1/FVC and the bronchodilator test index ΔFEV1. Average flow‐volume (FV) loops were generated for patients with pathologic spirometry to demonstrate the feasibility of EIT for graphic diagnosis of asthma.

Results

Spirometry and global EIT‐based FV loops showed a strong correlation (P < 0.001, r > 0.9 in FEV1 and FEV0.5). In all criteria, the binary classification tests yielded high specificity (>93%), a high positive predictive value (≥75%) and a high negative predictive value (>80%), while sensitivity was higher in ΔFEV1 (86.67%) and lower in FEV1/FVC (25% and 35.29%). A typical concave shape of the EIT‐derived average FV loops was observed for asthmatic children with improvement after bronchospasmolysis.

Conclusions

Global FV loops derived from EIT correlate well with spirometry. Positive bronchospasmolysis can be observed in EIT‐derived FV loops. Flow‐volume loops originated from EIT have a potential to visualize pulmonary function.
On the True Band Gap of the (CH3NH3)2Pb(SCN)2I2 Hybrid Perovskite: An Interesting Solar‐Cell Material
Authors: Clavijo Penagos Josue I. , Romero Eduard R. , Gordillo Gerardo , Correa Hoyos John M. , Reinoso Sánchez Miguel Á.
Published: February 2018

The hybrid halide perovskite methyl ammonium lead iodide thiocyanate – (CH3NH3)Pb(SCN)2I2 – is synthesized both as a powder and as a thin film. The crystal structure and key optical properties (band gap) are determined by diffuse reflectance spectra and X‐ray diffraction (Rietveld refinement) measurements and compared to density functional theory (DFT) state‐of‐the‐art calculations. It is found that the refined orthorhombic crystal structure presents 2D‐layer confinement, and that the optical band gap presented in this work does confirm some previous reports and rebuts other results, too.
Using white‐box nonlinear optimization methods in system dynamics policy improvement
Authors: Vierhaus Ingmar , Fügenschuh Armin , Gottwald Robert , Grösser Stefan
Published: February 2018

We present a new strategy for the direct optimization of the values of policy functions. This approach is particularly well suited to model actors with a global perspective on the system and relies heavily on modern mathematical white‐box optimization methods. We demonstrate our strategy on two classical models: market growth and World2. Each model is first transformed into an optimization problem by defining how the actor can influence the models' dynamics and by choosing objective functions to measure improvements. To improve comparability between different runs, we also introduce a comparison measure for possible interventions. We solve the optimization problems, discuss the resulting policies and compare them to the existing results from the literature. In particular, we present a run of the World2 model which significantly improves the published “towards a global equilibrium” run with equal cost of intervention.

Copyright © 2018 System Dynamics Society
Palladium Nanoparticles Supported on Hydroxyapatite Nanospheres: Highly Active, Reusable and Green Catalyst for Suzuki – Miyaura Cross Coupling Reactions under Aerobic Conditions
Authors: Bulut Ahmet , Aydemir Murat , Durap Feyyaz , Gülcan Mehmet , Zahmakiran Mehmet
Published: February 2018

The development of simply prepared, highly active and reusable nanocatalysts for Suzuki‐Miyaura cross coupling reactions under mild and green conditions remains a challenge in the field of synthetic organic chemistry. Herein, we describe a new nanocatalyst comprising of palladium nanoparticles supported on hydroxyapatite nanospheres, which can reproducibly be formed in‐situ during the Suzuki‐Miyaura coupling reactions starting with Pd(II)‐exchanged nanohydroxyapatite. The characterization of the resulting catalyst by using ICP‐OES, P‐XRD, XPS, TEM, HRTEM, SEM and N2‐adsorption‐desorption analyses revealed that the formation of 3.7 ± 1.3 nm palladium(0) nanoparticles (Pd(0)∼430 nanoclusters) on the surface of nano‐sized (∼ 50 nm) hydroxyapatite (nano‐HAp) support by keeping the host framework intact. This previously unappreciated combination of Pd NPs and nano‐HAp (PdNPs@nano‐HAp) shows excellent activities (TOF's > 3×105 h−1) in the Suzuki–Miyaura cross coupling reactions of different arylbromides with phenylboronic acid under mild, green and aerobic conditions. More importanly, these new supported palladium(0) nanoparticles were found to be highly durable nanocatalyst throughout the reusability experiments, they maintain almost their inherent activity after 10th catalytic cycle at high conversion (> 98%).
Ultrathin‐Branched Pt Grown on Quasi‐Sphere Pd with Enhanced Electrocatalytic Performances
Authors: Fang Caihong , Zhao Jian , Ding Qian , Yu Nan , Sang Yan , Geng Baoyou
Published: February 2018

Pt has been demonstrated as the most effective electrocatalyst in electrocatalytic methanol oxidation reaction. To overcome the high cost and scarcity of Pt and further improve its performances, we therefore synthesized Pd−Pt bimetallic nanostructures, in which Pd located at interior with Pt at exterior. The morphology of the bimetallic nanocrystals exhibits a branched structure with a porous architect by employed quasi‐spherical Pd nanoparticles as the stating nanocrystals followed by the growth of Pt on their surfaces. Significantly, the branches are ultra‐thin (less than 5.0 nm), which can supply sufficient active sites. We thus tested the electrocatalytic performances toward oxidation of methanol. The specific activity is even 2.7 times that of commercial Pt/C, while the mass activity is 5.5 times of the commercial Pt/C. Moreover, the durability was also highly improved. We believed that our structures can pay the way for the development of liquid fuel cells.
Probing of Reorganization Dynamics within the Different Phases of Themotropic Liquid Crystals
Authors: Panda Manas Ranjan , Koley Somnath , Mishra Krishna , Ghosh Subhadip
Published: February 2018

Solvent properties of two liquid crystalline solvents (LCs), 4‐n‐pentyl‐4/‐cyanobiphenyl (5CB) and 4‐n‐octyl‐4/‐cyanobiphenyl (8CB) are studied by exploiting their intrinsic fluorescence. Solvation dynamics of LCs in crystalline, liquid crystalline and liquid phases are observed by utilizing the dynamic Stokes shift in the time resolved emission spectrum (TRES) of an excited dye molecule coumarin 153 (C153) immersed within the LCs. With increasing temperature, transitions occur from crystalline to smectic/nematic and finally to liquid phase for these thermotropic LCs. At high temperature, liquid crystalline phases with substantial orientational orders are transformed to isotopic liquid phases. In this phase, peak positions of intrinsically fluorescent LCs are shifted towards the higher energy side with lowering its fluorescence quantum yields (φf) as compared to the emission peak positions and quantum yields of LCs in other anisotropic phases. Solvation dynamics study shows that the average solvation time of C153, immersed within the liquid phases of LCs, is about an order of magnitude faster as compared to that within a crystalline phase of the same substrate (5CB or 8CB). This observation is substantiating the fact that even within a complete crystalline phase a fluid like motion of the LC solvent molecules still exists. Average solvation time of C153 follows a descending order when we move from a complete crystalline phase to liquid crystalline phase to complete liquid phase.
C‐H Oxidation by a Diiron Complex with Facially Opposing Active Sites
Authors: Lindsay Stacey , Mader Sophie L. , Kaila Ville R. I. , Hess Corinna R.
Published: February 2018

C−H oxidation is catalyzed by a high‐spin ferrous dimer, [(L1)2Fe2(CH3CN)2](PF6)4 (1), that offers two identical functional sites, separated by > 7 Å. The complex provides a unique contrast to both mononuclear and binuclear non‐heme enzyme active sites as well as biomimetic complexes. The oxidative activity of 1 was examined using a range of substrates (cyclohexene, 9,10‐dihydroanthracene, xanthene, triphenylmethane, triphenylphosphine, and cyclohexane) and PhIO as an oxidant. The studies establish the O‐atom transfer and H‐atom abstraction ability of the diiron complex. We further probe the energetics of cyclohexene oxidation by 1 and derive putative mechanisms for the pathways of allylic alcohol and epoxide formation using density functional theory (DFT) calculations. The DFT calculations indicate that the oxidation reactions proceed via a FeIV=O species in the triplet state, and that both iron centers can act independently of each other. The combined results provide insight into hydrocarbon oxidation by non‐coupled binuclear systems.
Photosensitive Nanoparticles Combining Vascular‐Independent Intratumor Distribution and On‐Demand Oxygen‐Depot Delivery for Enhanced Cancer Photodynamic Therapy
Authors: Zhao Caiyan , Tong Yujia , Li Xianlei , Shao Leihou , Chen Long , Lu Jianqing , Deng Xiongwei , Wang Xuan , Wu Yan
Published: February 2018

In drug delivery, the poor tumor perfusion results in disappointing therapeutic efficacy. Nanomedicines for photodynamic therapy (PDT) greatly need deep tumor penetration due to short lifespan and weak diffusion of the cytotoxic reactive oxygen species (ROS). The damage of only shallow cells can easily cause invasiveness and metastasis. Moreover, even if the nanomedicines enter into deeper lesion, the effectiveness of PDT is limited due to the hypoxic microenvironment. Here, a deep penetrating and oxygen self‐sufficient PDT nanoparticle is developed for balanced ROS distribution within tumor and efficient cancer therapy. The designed nanoparticles (CNPs/IP) are doubly emulsified (W/O/W) from poly(ethylene glycol)‐poly(ε‐caprolactone) copolymers doped with photosensitizer IR780 in the O layer and oxygen depot perfluorooctyl bromide (PFOB) inside the core, and functionalized with the tumor penetrating peptide Cys‐Arg‐Gly‐Asp‐Lys (CRGDK). The CRGDK modification significantly improves penetration depth of CNPs/IP and makes the CNPs/IP arrive at both the periphery and hypoxic interior of tumors where the PFOB releases oxygen, effectively alleviating hypoxia and guaranteeing efficient PDT performance. The improved intratumoral distribution of photosensitizer and adequate oxygen supply augment the sensitivity of tumor cells to PDT and significantly improve PDT efficiency. Such a nanosystem provides a potential platform for improved therapeutic index in anticancer therapy.
Aromatic Alkylammonium Spacer Cations for Efficient Two‐Dimensional Perovskite Solar Cells with Enhanced Moisture and Thermal Stability
Authors: Thrithamarassery Gangadharan Deepak , Han Yujie , Dubey Ashish , Gao Xinyu , Sun Baoquan , Qiao Qiquan , Izquierdo Ricardo , Ma Dongling
Published: February 2018

Three‐dimensional (3D) perovskite solar cells are prone to degradation in the presence of moisture, heat, and light. Recently, two‐dimensional (2D) perovskites are synthesized by isolating metal halide perovskite layers using aliphatic or aromatic alkylammonium spacer cation, which can retain their performance under ambient humidity levels due to the hydrophobic property of the spacer cation. However, the best 2D perovskite thus far, using aliphatic short butylammonium (BA) cation as spacer cation, shows only a modest tolerance against moisture and heat due to the inferior hydrophobicity as well as the relatively smaller size of the BA cation. Here, a bulkier aromatic phenylethylammonium (PEA) used as a spacer cation to synthesis 2D perovksite in order to achieve highly stable solar cells. By modifying the crystallization process, an average power conversion efficiency (PCE) of 5.50% is achieved, which is the highest reported PCE for aromatic alkylammonium‐based lower dimensional perovskite solar cells. Importantly, unencapsulated (PEA)2(MA)3Pb4I13 devices show enhanced moisture stability compared to other reported perovskite solar cells in harsh moisture environment (72 ± 2% relative humidity). Moreover, the use of organic materials in p‐i‐n type device, instead of metal oxides, as electron and hole extraction layers also paves the way toward constructing flexible perovskite solar cells.
Minimization of harmonic distortion impact due to large‐scale fast charging station using Modified Lightning Search Algorithm and Pareto‐Fuzzy synergistic approach
Authors: Syed Nasir S.N. , Jamian J.J. , Mustafa M.W.
Published: February 2018

The increased number of nonlinear loads in the distribution system has caused a significant impact on its power quality in the form of higher harmonic distortion. The fast charging station (FCS) is an example of a powerful nonlinear load that is currently being widely promoted with the aim of supporting the continuous usage of electric vehicles (EV). The most common and cheapest method to minimize harmonic impact is through the use of a passive filter. This paper presents an optimal sizing and placement of a passive filter design based on the numbers of FCS installed in the distribution system. The MATLAB/m‐file platform is used to model the power system harmonic flow, passive filter, and FCS. The control strategy used to minimize the total harmonic distortion (THD) due to the large number of FCS is presented based on the selection of optimal location and the size of passive filters that will provide minimum THD and apparent power losses to the overall distribution system. A Modified Lightning Search Algorithm (MLSA) technique is applied with the aim of identifying the optimal solution. The Pareto‐Fuzzy technique is used to obtain a better solution among nondominated solutions. From the result, the optimal placements and sizes of passive filter will be able to reduce the maximum THD and also the total losses in the distribution system, which is equipped with 17 FCS units. This study is useful as a guide for grid owners to control the impact of large‐scale FCS deployment in the distribution system. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A wind field downscaling strategy based on domain segmentation and transfer functions
Authors: Barcons Jordi , Avila Matias , Folch Arnau
Published: February 2018

This paper presents a novel methodology for mesoscale‐to‐microscale downscaling of near‐surface wind fields. The model chain consists on the Weather Research and Forecast mesoscale model and the Alya‐CFDWind microscale model (assuming neutral stability). The downscaling methodology combines precomputed microscale simulations with a mesoscale forecast using a domain segmentation technique and transfer functions. As a result, the downscaled wind field preserves the mesoscale pattern but, at the same time, incorporates local mesoscale subgrid terrain effects, particularly at valleys and channelling zones. The methodology has been validated over a 9‐month period on a very complex terrain site instrumented with a dense observational network of meteorological masts. With respect to mesoscale results, the global skills of the downscaled wind at masts improve for wind direction and remain similar for wind velocity. However, a substantial improvement occurs under stable and neutral conditions and for high wind velocity regimes.
New perspectives on telomerase RNA structure and function
Authors: Musgrove Cherie , Jansson Linnea I. , Stone Michael D.
Published: February 2018

Telomerase is an ancient ribonucleoprotein (RNP) that protects the ends of linear chromosomes from the loss of critical coding sequences through repetitive addition of short DNA sequences. These repeats comprise the telomere, which together with many accessory proteins, protect chromosomal ends from degradation and unwanted DNA repair. Telomerase is a unique reverse transcriptase (RT) that carries its own RNA to use as a template for repeat addition. Over decades of research, it has become clear that there are many diverse, crucial functions played by telomerase RNA beyond simply acting as a template. In this review, we highlight recent findings in three model systems: ciliates, yeast and vertebrates, that have shifted the way the field views the structural and mechanistic role(s) of RNA within the functional telomerase RNP complex. Viewed in this light, we hope to demonstrate that while telomerase RNA is just one example of the myriad functional RNA in the cell, insights into its structure and mechanism have wide‐ranging impacts. WIREs RNA 2018, 9:e1456. doi: 10.1002/wrna.1456

This article is categorized under:

RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems

RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry

RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution
The Results of In Situ Prosthetic Graft Replacement for Infected Aortic Disease
Authors: Han Youngjin , Kwon Tae‐Won , Park Sang Jun , Jeong Min‐Jae , Choi Kyunghak , Ko Gi‐Young , Lee Sang‐Oh , Cho Yong‐Pil
Published: February 2018

Background

Infected aortic disease is a serious clinical condition associated with significant morbidity and mortality. This study reviewed the outcomes of in situ aortic replacement with a prosthetic graft for infected aortic disease, including primary infected abdominal aortic aneurysms (PIAAA), infected aortic prosthetic grafts (IAPG), and infected aortic stent grafts (IASG).

Methods

Twenty‐eight consecutive patients who underwent in situ aortic replacement with a prosthetic graft for PIAAA, IAPG, and IASG at a single center from January 2001 to December 2015 were retrospectively analyzed. Demographics, clinical characteristics, medical management, surgical procedure, and clinical outcomes were included.

Results

Nineteen patients with a PIAAA, three with an IAPG following open repair of abdominal aortic aneurysm (AAA), and six with an IASG following endovascular aortic repair underwent in situ prosthetic graft replacement with infected tissue and graft removal. In‐hospital mortality was 7.1% (2/28). One died of bleeding on postoperative day 12, and the other died of hepatic failure on postoperative day 32. Of six patients with an IASG, two had major complications that were related to barb injury at the proximal aorta. The reinfection rate was 14.3% (4 of 28) during a mean follow‐up of 35.7 months (1–142 months). All new grafts of three patients with IAPG were reinfected. The other patient became reinfected after surgery for PIAAA with iatrogenic small bowel perforation that was not detected during surgery.

Conclusions

In situ graft replacement of PIAAA and IASG is feasible with acceptable outcomes, but the outcome for IAPG is questionable.