bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of High Pressure Homogenization on Free Fatty Acid Formation in Nannochloropsis sp.
Authors: Balduyck Lieselot , Bruneel Charlotte , Goiris Koen , Dejonghe Céline , Foubert Imogen
Published: January 2018

Although Nannochloropsis lipids have many potential applications in biofuels and high value products, their extraction is limited by the tough cell wall of this species. High pressure homogenization (HPH) can be used to improve the extraction efficiency. However, this can possibly induce free fatty acid (FFA) formation, which has a negative impact on oil quality. In this study, the HPH pressure and number of passes are varied in a full factorial design to study the impact of these factors on FFA formation, lipid extraction efficiency, and fatty acid profile. It is found that substantial amounts of FFA are formed during HPH treatments when compared to the non‐disrupted biomass. The FFA formation is mostly influenced by the number of passes applied, which can explained by a combined effect of the longer time residing as a wet paste and the temperature increase during the treatment. The large amount of FFA formed during the least intensive HPH treatment is in contrast with only a slight increase of the lipid extraction efficiency, which indicates that minor damage to the cell is sufficient to induce lipolytic reactions. The relative fatty acid profile after HI extraction is not influenced by the HPH treatment.

Practical Applications: These results have important implications for the application of HPH treatments on microalgae with the aim to improve the extraction efficiency. It is demonstrated that more intensive HPH treatments with several passes are necessary to improve the extraction efficiency of Nannochloropsis lipids. However, the least intensive HPH treatments (1 pass at 400 bar) already induced the formation of substantial amounts of FFA. Consequently, to produce a biomass with a low FFA content and a high lipid extraction efficiency, a compromise should thus be made.

High pressure homogenization (HPH) can efficiently be used to improve the extraction effiency of interesting compounds from Nannochloropsis cells. However, this treatment also induces the formation of free fatty acids (FFA), which have a negative influence on oil quality.
Temporal and spatial adjustments of channel migration and planform geometry: responses to ENSO driven climate anomalies on the tropical freely‐meandering Aguapeí River, São Paulo, Brazil
Authors: Suizu Tainá Medeiros , Nanson Gerald C.
Published: January 2018

Two reaches of Aguapeí River, a left‐bank tributary of the Paraná River in western São Paulo state, Brazil, were studied with the objective of assessing the role of bend curvature on channel migration in this wet‐tropical system and examining if land‐use changes or ENSO (El Niño Southern Oscillation) driven climate anomalies over nearly half a century have changed migration behaviour and planform geometry. Meander‐bend migration rates and morphometric parameters including meander‐bend curvature, sinuosity, meander wavelength and channel width, were measured and the frequency of bend cutoffs was analysed in order to determine the rate of change of channel adjustment over a 48 year period to 2010. Results show that maximum average channel migration rates occur in bends with curvatures of about 2–3 rc/w, similar to other previously studied temperate and subarctic freely meandering rivers although not as pronounced and with a tendency to favour tighter curvature. From 1962 to 2010 the Aguapeí River has undergone a significant reduction in sinuosity, a shift from tightly curving to more open bends, an overall decline in channel migration rates, an associated decrease in the frequency of neck‐cutoffs and an overall increase in channel width. As the majority of the drainage basin (96%) was already deforested in 1962, channel form and process changes were, unlike an interpretation for an adjacent river system, not attributed to altered land‐use but rather to a sharp ENSO‐driven increase in the magnitude of peak flow‐discharges of some 32% since 1972. In summary, this research revealed that recent climate and associated flow regime changes are having a pronounced effect on river channel behaviour in the Aguapeí River investigated here. Copyright © 2018 John Wiley & Sons, Ltd.
Assessing and mitigating simulated population-level effects of 3 herbicides to a threatened plant: Application of a species-specific population model of Boltonia decurrens
Authors: Schmolke Amelie , Brain Richard , Thorbek Pernille , Perkins Daniel , Forbes Valery
Published: January 2018

Extrapolating from organism-level endpoints, as generated from standard pesticide toxicity tests, to populations is an important step in threatened and endangered species risk assessments. We apply a population model for a threatened herbaceous plant species, Boltonia decurrens, to estimate the potential population-level impacts of 3 herbicides. We combine conservative exposure scenarios with dose–response relationships for growth and survival of standard test species and apply those in the species-specific model. Exposure profiles applied in the B. decurrens model were estimated using exposure modeling approaches. Spray buffer zones were simulated by using corresponding exposure profiles, and their effectiveness at mitigating simulated effects on the plant populations was assessed with the model. From simulated exposure effects scenarios that affect plant populations, the present results suggest that B. decurrens populations may be more sensitive to exposures from herbicide spray drift affecting vegetative stages than from runoff affecting early seedling survival and growth. Spray application buffer zones were shown to be effective at reducing effects on simulated populations. Our case study demonstrates how species-specific population models can be applied in pesticide risk assessment to bring organism-level endpoints, exposure assumptions, and species characteristics together in an ecologically relevant context. Environ Toxicol Chem 2018;37:1545–1555. © 2018 SETAC
Past and present mercury accumulation in the Lake Baikal seal: Temporal trends, effects of life history, and toxicological implications
Authors: Poste Amanda E. , Pastukhov Mikhail V. , Braaten Hans Fredrik Veiteberg , Ozersky Ted , Moore Marianne
Published: January 2018

Despite global efforts to reduce anthropogenic mercury (Hg) emissions, the timescale and degree to which Hg concentrations in the environment and biota respond to decreased emissions remain challenging to assess or predict. In the present study we characterize long-term trends and life-history patterns in Hg accumulation and toxicological implications of Hg contamination for a freshwater seal from one of the world's largest lakes (Lake Baikal, Siberia, Russia) using contemporary tissues and archival teeth. Stable isotope analysis and Hg analyses of soft tissues (muscle, liver, kidney, blood, brain, heart) and teeth from 22 contemporary seals revealed rapid changes in diet and Hg accumulation in the first year of life with a stable diet and increase in tissue Hg throughout the rest of life. Although maternal transfer of Hg was an important source of Hg to seal pups, reproduction and lactation by female seals did not appear to result in sex-related differences in Hg concentrations or age-related accumulation in adult seals. Based on Hg analysis of archival teeth (n = 114) and reconstructed values for soft tissues, we also assessed temporal trends in seal Hg between the years 1960 and 2013. Seal Hg concentrations in hard (teeth) and soft (e.g., muscle, liver) tissues were highest in the 1960s and 1970s, followed by a decrease. The decline in seal Hg concentrations in recent decades was most likely driven by a reduction in Hg inputs to the lake, suggesting that global and regional efforts to reduce Hg emissions have been successful at reducing ecosystem and human health risks posed by Hg in Lake Baikal. Environ Toxicol Chem 2018;37:1476–1486. © 2018 SETAC
Fuzzy logic vector–based forwarding routing protocol for underwater acoustic sensor networks
Authors: Bu Renfei , Wang Shilian , Wang Hao
Published: January 2018

The sensor nodes working in the underwater environment are generally powered by batteries, which are undesirable or infeasible to replace and recharge. Thus, limited energy is one of the major constraints in underwater acoustic sensor networks. It is of great significance to design an energy‐efficient routing algorithm to prolong network lifetime. In this paper, we propose a fuzzy logic vector–based forwarding routing protocol wherein we consider both the position information and energy information of sensor nodes in the calculation of desirableness. In addition, parameters such as valid distance to forwarder nodes, projection, and the battery level of nodes are also considered in fuzzy logic system. The fuzzy logic–based energy‐efficient routing algorithm can achieve multiparameter and fuzzy routing decision. The performance analyses show that the routing protocol we proposed has better performance in energy consumption and average end‐to‐end delay compared with the similar algorithms; meanwhile, reliability can be guaranteed.
Geochemical characteristics of light hydrocarbons and their influencing factors in natural gases of the Kuqa Depression, Tarim Basin, NW China
Authors: Peng Weilong , Hu Guoyi , Wang Youwei , Liu Dan , Lv Yue , Luo Xiao
Published: January 2018

In order to determine the source of the light hydrocarbons in the Kuqa Depression of the Tarim Basin, Northwest China, their geochemical characteristics are documented, and possible influencing factors are discussed in a broad context on the basis of geochemical analyses of natural gas samples from 19 wells in combination with previously reported natural gas components and carbon isotope values from the same depression. The biomarker analytical results show that (a) methyl cyclohexane (37.5–60.3%) of natural gas predominates the C7 light hydrocarbon series (methyl cyclohexane, heptanes, and dimethyl cyclopentane), and (b) the heptane content (25.0–54.8%) is also relatively high. The C6–7 light hydrocarbon series (aromatics, normal alkanes, and cycloalkanes) have abnormally high aromatics (benzene and toluene) content (26.2–83.8%). Heptane value (13.31–37.77%) and isoheptane value (2.10–7.64%) indicate that the Kuqa natural gases are of high maturity and typical of coal‐derived gas (gas generated by sapropelic source rock). Their light hydrocarbons, however, appear to have some characteristics of mixed‐source organic matter. Specifically, the light hydrocarbons in the Dina 2 gas field show characteristics of the coal‐derived gas; those in the Dabei gas field show some features of the oil‐associated gas (gas generated by humic source rock), whereas those in the Kela 2 and Keshen 2 gas fields and Well Yangtake‐101 display characteristics of the mixed source organic matter. The abnormally high content of the aromatics in the Kuqa Depression may have resulted mainly from their high productivity during the thermal maturity of humic type organic matters and the gases accumulation of late stage. The different relative contents of the aromatics in various oil and gas fields may have been accounted by different organic matter types, maturity, and distribution patterns of source rocks.
Exophytic sinonasal papillomas and nasal florid papillomatosis: A retrospective study
Authors: Glâtre Romain , De Kermadec Héloïse , Alsamad Issam Abd , Badoual Cécile , Gauthier Anne , Brugel Lydia , Parra Claire , Coste André , Prulière‐Escabasse Virginie , Bequignon Emilie
Published: January 2018

Background

Sinonasal exophytic papillomas are rare. The multifocal form, florid papillomatosis, has not been yet described in literature. We report on the clinical features and the management of the different forms of exophytic papilloma.

Methods

A retrospective study was conducted that included all patients with exophytic papilloma treated in our center over the past 12 years. We recorded clinical presentation, treatments, recurrences, pathology (p16 expression and human papillomavirus [HPV] status).

Results

We included 13 patients with a mean follow‐up of 5 years. The main location of exophytic papilloma was the anterior part of the septum. Lesions were multifocal in 3 patients corresponding to florid papillomatosis. The main treatment was surgery. Cases of HPV‐11 or HPV‐6 were present in all forms of exophytic papilloma (dysplasia in 4 cases). Late recurrences occurred in 3 patients (2 patients with florid papillomatosis) over a period of 3 years.

Conclusion

Exophytic papilloma has 2 clinical presentations: localized and diffuse. Patients with florid papillomatosis should be monitored closely as recurrence seems to be frequent.
The medial temporal lobe functional connectivity patterns associated with forming different mental representations
Authors: Sheldon Signy , Levine Brian
Published: January 2018

The medial temporal lobes (MTL), and more specifically the hippocampus, are critical for forming mental representations of past experiences—autobiographical memories—and for forming other “nonexperienced” types of mental representations, such as imagined scenarios. How the MTL coordinate with other brain areas to create these different types of representations is not well understood. To address this issue, we performed a task‐based functional connectivity analysis on a previously published dataset in which fMRI data were collected as participants created different types of mental representations under three conditions. One condition required forming and relating together details from a past event (autobiographical task), another required forming and relating together details of a spatial context (spatial task) and another condition required relating together conceptual/perceptual features of an object (conceptual task). We contrasted the connectivity patterns associated with a functionally defined region in the parahippocampal cortex (PHC) and anatomically defined anterior and posterior hippocampal segments across these tasks. Examining PHC connectivity patterns revealed that the PHC seed was distinctly connected to other MTL structures during the autobiographical task, to posterior parietal regions during the spatial task and to a distributed network of regions for the conceptual task. Examining hippocampal connectivity patterns revealed that the anterior hippocampus was preferentially connected to regions of default mode network during the autobiographical task and to areas implicated in semantic processing for the conceptual task whereas the posterior hippocampus was preferentially connected to medial‐posterior regions of the brain during the spatial task. We interpret our findings as evidence that there are MTL‐guided networks for forming distinct types of mental representations that align with functional distinctions within the hippocampus.
Computational intelligence techniques for human brain MRI classification
Authors: El‐Dahshan El‐Sayed A. , Bassiouni Mahmoud M.
Published: January 2018

This study proposes an image classification methodology that automatically classifies human brain magnetic resonance (MR) images. The proposed methods contain four main stages: Data acquisition, preprocessing, feature extraction, feature reduction and classification, followed by evaluation. First stage starts by collecting MRI images from Harvard and our constructed Egyptian database. Second stage starts with noise reduction in MR images. Third stage obtains the features related to MRI images, using stationary wavelet transformation. In the fourth stage, the features of MR images have been reduced using principles of component analysis and kernel linear discriminator analysis (KLDA) to the more essential features. In last stage, the classification stage, two classifiers have been developed to classify subjects as normal or abnormal MRI human images. The first classifier is based on K‐Nearest Neighbor (KNN) on Euclidean distance. The second classifier is based on Levenberg‐Marquardt (LM‐ANN). Classification accuracy of 100% for KNN and LM‐ANN classifiers has been obtained. The result shows that the proposed methodologies are robust and effective compared with other recent works.
Human teeth biobank: Microbiological analysis of the teeth storage solution
Authors: Curylofo‐Zotti Fabiana Almeida , Lorencetti‐Silva Francine , de Almeida Coelho Jéssica , Monteiro Rachel Maciel , Watanabe Evandro , Corona Silmara Aparecida Milori
Published: January 2018

The cross‐infections may occur during handling of dental elements, affecting the health of dental practitioners and researchers. This study aimed to analyze the influence of the storage medium temperature on the bacterial contingent of the human teeth used for research purposes. Thirty human teeth were donated to the Human Teeth Biobank immediately after extraction. The teeth were cleaned with tap water and neutral soap. The teeth were randomly distributed according to the temperature of the storage solution (deionized water): at 4 °C (refrigerator) or at −10 °C (freezer) and were stored individually in sterile vials during 60 days. After this period, a microbiological analysis (CFU/mL) of the storage solutions was performed and teeth were submitted to SEM analysis. Data were analyzed by Kruskal–Wallis test followed by Dunn's post‐test (p ≤ .05). Total aerobic bacteria ranged from 5.8 to 8.4 log10 CFU/mL for refrigerated solution and from 1.9 to 8.5 log10 CFU/mL for frozen solution. No statistical differences were found between the storage solutions (p > .05). The counts of Streptococcus spp., Lactobacillus spp., and Staphylococcus spp. were similar for both storage solutions (p > .05). SEM analysis showed spiral‐ and rod‐shaped bacteria attached on teeth stored under 4 °C, which may suggest the presence of Treponema spp. and Lactobacillus spp. Similar morphological forms were found on teeth stored under −10 °C. A biofilm organized in honeycomb‐like form was found in the frozen teeth. Cocci were eventually found in all the samples. It was concluded that bacterial growth and survival were not influenced by the temperature of the teeth storage solution.
Inhibition of soluble epoxide hydrolase attenuates eosinophil recruitment and food allergen-induced gastrointestinal inflammation
Authors: Bastan Idil , Ge Xiao Na , Dileepan Mythili , Greenberg Yana G , Guedes Alonso G , Hwang Sung Hee , Hammock Bruce D , Washabau Robert J , Rao Savita P , Sriramarao P
Published: January 2018

Prevalence of food allergies in the United States is on the rise. Eosinophils are recruited to the intestinal mucosa in substantial numbers in food allergen-driven gastrointestinal (GI) inflammation. Soluble epoxide hydrolase (sEH) is known to play a pro-inflammatory role during inflammation by metabolizing anti-inflammatory epoxyeicosatrienoic acids (EETs) to pro-inflammatory diols. We investigated the role of sEH in a murine model of food allergy and evaluated the potential therapeutic effect of a highly selective sEH inhibitor (trans-4-{4-[3-(4-trifluoromethoxyphenyl)-ureido]-cyclohexyloxy}-benzoic acid [t-TUCB]). Oral exposure of mice on a soy-free diet to soy protein isolate (SPI) induced expression of intestinal sEH, increased circulating total and antigen-specific IgE levels, and caused significant weight loss. Administration of t-TUCB to SPI-challenged mice inhibited IgE levels and prevented SPI-induced weight loss. Additionally, SPI-induced GI inflammation characterized by increased recruitment of eosinophils and mast cells, elevated eotaxin 1 levels, mucus hypersecretion, and decreased epithelial junction protein expression. In t-TUCB-treated mice, eosinophilia, mast cell recruitment, and mucus secretion were significantly lower than in untreated mice and SPI-induced loss of junction protein expression was prevented to variable levels. sEH expression in eosinophils was induced by inflammatory mediators TNF-α and eotaxin-1. Treatment of eosinophils with t-TUCB significantly inhibited eosinophil migration, an effect that was mirrored by treatment with 11,12-EET, by inhibiting intracellular signaling events such as ERK (1/2) activation and eotaxin-1-induced calcium flux. These studies suggest that sEH induced by soy proteins promotes allergic responses and GI inflammation including eosinophilia and that inhibition of sEH can attenuate these responses.

Soy protein-induced soluble epoxide hydrolase promotes allergic responses, gastrointestinal inflammation and eosinophilia; pharmacological inhibition of this enzyme leads to attenuation of these responses.
SHIP negatively regulates type II immune responses in mast cells and macrophages
Authors: Dobranowski Peter , Sly Laura M
Published: January 2018

SHIP is a hematopoietic-specific lipid phosphatase that dephosphorylates PI3K-generated PI(3,4,5)-trisphosphate. SHIP removes this second messenger from the cell membrane blunting PI3K activity in immune cells. Thus, SHIP negatively regulates mast cell activation downstream of multiple receptors. SHIP has been referred to as the “gatekeeper” of mast cell degranulation as loss of SHIP dramatically increases degranulation or permits degranulation in response to normally inert stimuli. SHIP also negatively regulates Mϕ activation, including both pro-inflammatory cytokine production downstream of pattern recognition receptors, and alternative Mϕ activation by the type II cytokines, IL-4, and IL-13. In the SHIP-deficient (SHIP−/−) mouse, increased mast cell and Mϕ activation leads to spontaneous inflammatory pathology at mucosal sites, which is characterized by high levels of type II inflammatory cytokines. SHIP−/− mast cells and Mϕs have both been implicated in driving inflammation in the SHIP−/− mouse lung. SHIP−/− Mϕs drive Crohn's disease-like intestinal inflammation and fibrosis, which is dependent on heightened responses to innate immune stimuli generating IL-1, and IL-4 inducing abundant arginase I. Both lung and gut pathology translate to human disease as low SHIP levels and activity have been associated with allergy and with Crohn's disease in people. In this review, we summarize seminal literature and recent advances that provide insight into SHIP's role in mast cells and Mϕs, the contribution of these cell types to pathology in the SHIP−/− mouse, and describe how these findings translate to human disease and potential therapies.
A physics‐based threshold voltage model for hetero‐dielectric dual material gate Schottky barrier MOSFET
Authors: Kumar Prashanth , Bhowmick Brinda
Published: January 2018

This paper presents the analytical model of threshold voltage for hetero‐dielectric dual material gate Schottky barrier (SB) metal oxide semiconductor field effect transistor (MOSFET). The threshold voltage model is derived on the basis of the surface potential model. The threshold voltage is extracted using transconductance change method. The two‐dimensional surface potential, electric field, and threshold voltage model for the hetero‐dielectric dual material gate SB‐MOSFET are developed using 2‐D Poisson's equation, which satisfies the boundary conditions. Moreover, the model precisely depict the impact of hetero‐gate dielectric and gate oxide thickness on the surface potential, and threshold voltage of the hetero‐dielectric dual material gate SB and compared with single material gate SB‐MOSFET. Finally, a good agreement between the model results and numerical simulated results is achieved.
Future changes in extreme precipitation indices over Korea
Authors: Kim Gayoung , Cha Dong‐Hyun , Park Changyong , Lee Gil , Jin Chun‐Sil , Lee Dong‐Kyou , Suh Myoung‐Seok , Ahn Joong‐Bae , Min Seung‐Ki , Hong Song‐You , Kang Hyun‐Suk
Published: January 2018

In this study, the regional climate of the Korean Peninsula is dynamically downscaled using a high‐resolution regional climate model forced by two representative concentration pathway scenarios of Hadley Centre Global Environmental Model version 2‐Atmosphere and Ocean (HadGEM2‐AO) using multiple regional climate models. Changes in extreme precipitation indices are investigated. Through the evaluation of the present climate, a multi‐model ensemble reasonably reproduces the long‐term climatology of extreme precipitation indices over South Korea despite some systematic errors. Both mean and extreme precipitation intensities for 80 years in the future (2021–2100) increase compared to those of the present. However, the increasing rates of indices related to precipitation intensities are different according to sub‐period, season, and emission scenarios. Mean and extreme precipitation intensities of the future climate increase during the summer when most extreme precipitation events occur over the Korean Peninsula. Also, abnormal extreme precipitation can increase during future summers due to increasing variances of indices related to extreme precipitation intensity. Increasing extreme summer precipitation over South Korea is proportional to the increases in convective precipitation compared to non‐convective precipitation. This indicates that future changes in summer precipitation, with regard to intensity and frequency, over South Korea, among representative concentration pathway scenarios, are more related to a change in convective instability rather than synoptic condition.
Mesoporous Poly(divinylbenzene) Fibers Based On Crosslinked Nanoparticles
Authors: Migenda Julia , Werner Sebastian , Ellinghaus Rüdiger , Smarsly Bernd M.
Published: January 2018

Poly(divinylbenzene) (PDVB) nanofibers are synthesized by electrospinning dispersions of PDVB nanoparticles (diameter 40–90 nm) derived by miniemulsion polymerization. Interparticle crosslinking is achieved by addition of a radical starter after electrospinning endowing the fibers with high solvent‐stability. The fibers exhibit a Brunauer–Emmett–Teller (BET) surface area in the range of ≈30–70 m2 g−1 due to internal mesoporosity, which originates from the interparticle space. Spinning parameters like the concentrations of spin polymer and nanoparticles, as well as the nanoparticle diameter, are systematically varied to investigate the influence of these parameters on the mesopore structure. The fiber morphology is studied by scanning electron microscopy and the mesopore size, volume, and BET surface area are determined by nitrogen physisorption measurements. The findings indicate that the pore size mainly depends on the PDVB nanoparticle diameter. As a main finding, the fiber diameter can be adjusted by the concentration of spin polymer or nanoparticles without changing the mesopore diameter. Chlorine‐functionalized fibers are synthesized by electrospinning of poly(divinylbenzene‐co‐4‐vinylbenzyl chloride) nanoparticle dispersions. Chlorine groups are further used for the covalent immobilization of an organocatalyst (2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO)).
Research on the Preparation of Polycaprolactone Porous Films with Decoration of Protein Arrays via the Emulsion‐Based Breath Figure Method
Authors: Ding Lingyun , Sun Wei , Ju Yuanlai , Cui Pengcheng , Wang Siyu , Huang Junjie , Zhou Wanrong , Zhu Jiafeng
Published: January 2018

A facile method to fabricate honeycomb‐patterned biocompatible polycaprolactone (PCL) films with cavities that are selectively decorated with protein by one‐step method is developed in this study. To carry out this method, proteins carried in water are dispersed into chloroform solution of PCL to form inverse emulsion with the assistance of the chitosan particles serving as emulsifier. The evaporation of the organic solvent in the inverse emulsion on substrate under a high‐humidity atmosphere leads to the formation of ordered porous arrays incorporated with proteins on the inner surface of the cavities. The method, based on the combination of breath figures and inverse emulsion template, provides a reliable route for the directed assembly of water‐soluble materials into patterned polymer matrix. It has the potential to be further established as a novel procedure to fabricate a multifunctional hybrid porous structure containing hydrophilic component based on the breath figure method.
Nanostructured Biopolymer/Few‐Layer Graphene Freestanding Films with Enhanced Mechanical and Electrical Properties
Authors: Silva Cláudia , Caridade Sofia G. , Cunha Eunice , Sousa Maria P. , Rocha Helena , Mano João F. , Paiva Maria C. , Alves Natália M.
Published: January 2018

In the present work, novel freestanding multilayered films based on chitosan (CHI), alginate (ALG), and functionalized few‐layer graphene are developed through layer‐by‐layer assembly. First, functionalized few‐layer graphene aqueous suspensions are prepared from graphite by a stabilizer‐assisted liquid phase exfoliation process, using a pyrene derivative as stabilizer. Afterward, the films are produced and their physical, morphological, thermal, and mechanical properties are evaluated. Furthermore, their degradation and swelling profiles, as well as their biological behavior, are assessed. The incorporation of functionalized few‐layer graphene results in films with a nanolayered structure, lower roughness than the control CHI/ALG films, and hydrophilic behavior. The mechanical characterization reveals an increase of the Young's modulus, ultimate tensile strength, and elongation at break due to the incorporation of the graphene derivative. A decrease in the electrical resistivity of the multilayered films is also observed. The biological assays reveal improved cytocompatibility toward L929 cells when functionalized few‐layer graphene is incorporated in the CHI/ALG matrix. Therefore, these new graphene‐reinforced multilayered films exhibit interesting properties and great potential for biomedical applications, particularly in wound healing and cardiac and bone tissue engineering.
Evolutionary and genetic features of drug targets
Authors: Quan Yuan , Wang Zhong‐Yi , Chu Xin‐Yi , Zhang Hong‐Yu
Published: January 2018

In the modern drug discovery pipeline, identification of novel drug targets is a critical step. Despite rapid progress in developing biomedical techniques, it is still a great challenge to find promising new targets from the ample space of human genes. This fact is partially responsible for the situation of “more investments, fewer drugs” in the pharmaceutical industry. A series of recent researches revealed that successfully targeted genes share some common evolutionary and genetic features, which means that the knowledge accumulated in modern evolutionary biology and genetics is very helpful to identify potential drug targets and to find new drugs as well. In this article, we comprehensively summarize the links between human drug targets and genetic diseases and their evolutionary origins, with an attempt to introduce these novel concepts and their medical implications to the biomedical community.
Rhodol Derivatives as Selective Fluorescent Probes for the Detection of HgII Ions and the Bioimaging of Hypochlorous Acid
Authors: Li Ling , Wang Shu , Lan Hongxia , Gong Guiyi , Zhu Yifan , Tse Yu Chung , Wong Keith Man‐Chung
Published: January 2018

Invited for this month's cover picture is the group of Professor Keith Man‐Chung Wong from the Southern University of Science and Technology (P.R. China). The cover picture illustrates a novel rhodol‐based fluorescence probe from the structural combination of rhodamine and fluorescein motifs. Read the full text of their Full Paper at 10.1002/open.201700154.
Bias from restricting to live births when estimating effects of prescription drug use on pregnancy complications: A simulation
Authors: Suarez Elizabeth A. , Landi Suzanne N. , Conover Mitchell M. , Jonsson Funk Michele
Published: January 2018

Purpose

Administrative claim databases are increasingly being used to study the safety of medication exposures during pregnancy. These studies are restricted to live births due to a reliance on algorithms for estimating gestational age that are based on codes associated with live delivery. Conditioning on live birth may induce selection bias when studying the effect of a drug on a pregnancy complication if fetal death is a competing risk for the complication or is caused by the complication.

Methods

We simulated a population of 100,000 pregnancies and estimated the impact of selection bias on relative estimates for the effect of antidepressant exposure on the outcome of preeclampsia. We assumed that the exposure, outcome, and covariates increased the risk of fetal loss.

Results

A downward bias in the risk ratio was consistently observed when conditioning on live births. When an unmeasured covariate was assumed to be a common cause of fetal death, antidepressant use, and preeclampsia, the direction of bias varied depending on the strength of the confounding relationship coupled with the selection bias. Despite the very low prevalence of stillbirth, the strength of the relationship between antidepressant use and stillbirth had a substantial impact on bias.

Conclusions

Conditioning on live birth can be problematic when studying pregnancy complications. Simple quantitative selection bias analysis in populations restricted to live births may not fully account for selection bias.
High‐throughput method to deposit continuous composition spread Sb2(SexS1 − x)3thin film for photovoltaic application
Authors: Deng Hui , Yuan Shengjie , Yang Xiaokun , Zhang Jian , Khan Jahangeer , Zhao Yang , Ishaq Muhammad , Ye Wanneng , Cheng Yi‐Bing , Song Haisheng , Tang Jiang
Published: January 2018

Sb2(SexS1 − x)3alloy materials with tunable bandgaps combining the advantages of Sb2S3and Sb2Se3showed high potential in low cost, non‐toxicity, and high stability solar cells. The composition dependence of device performance becomes indispensable to study. However, traditional approaches often implement 1 composition at a time, which easily lead to long period and systematic errors. The present work developed a high‐throughput experimental method, close‐space dual‐plane‐source evaporation (CDE) method, to successfully deposit continuous composition spread Sb2(SexS1 − x)3library at 1 time. On the surface of the obtained film, thexvalue of Se content evolved from 0.09 to 0.84 by a series of complementary characterizations. At depth direction, the alloy film kept high crystallinity and composition consistency. Solar cell arrays (19 × 6) were fabricated to investigate the relationship between compositions and performances. As the increase of Se content, the conversion efficiency first increased from 1.8% to 5.6% and then decreased to 5%. The Vocand Jscdemonstrated an opposite evolution trend. The champion device with the composition of Sb2(Se0.68S0.32)3achieved the Vocand Jsctrade‐off exceeding the performances of Sb2S3(2.43%) and Sb2Se3(4.97%) devices. Cryogenic and transient characterizations were utilized to investigate the distinct performance evolution mechanism. There existed shallow defect levels in Se‐rich alloys and deep defects in sulfur‐rich ones. The widely tuned absorber compositions combined with distinct defect characters induced to the large variation of device performance. The present continuous composition spread Sb2(SexS1 − x)3film and their CDE fabrication technique were expected to efficiently screen materials and promote the development of antimony chalcogenide solar cells.
Differential role of PTEN in transforming growth factor β (TGF‐β) effects on proliferation and migration in prostate cancer cells
Authors: Kimbrough‐Allah Mawiyah N. , Millena Ana C. , Khan Shafiq A.
Published: January 2018

Background

Transforming growth factor‐β (TGF‐β) acts as a tumor suppressor in normal epithelial cells but as a tumor promoter in advanced prostate cancer cells. PI3‐kinase pathway mediates TGF‐β effects on prostate cancer cell migration and invasion. PTEN inhibits PI3‐kinase pathway and is frequently mutated in prostate cancers. We investigated possible role(s) of PTEN in TGF‐β effects on proliferation and migration in prostate cancer cells.

Methods

Expression of PTEN mRNA and proteins were determined using RT‐PCR and Western blotting in RWPE1 and DU145 cells. We also studied the role of PTEN in TGF‐β effects on cell proliferation and migration in DU145 cells after transient silencing of endogenous PTEN. Conversely, we determined the role of PTEN in cell proliferation and migration after over‐expression of PTEN in PC3 cells which lack endogenous PTEN.

Results

TGF‐β1 and TGF‐β3 had no effect on PTEN mRNA levels but both isoforms increased PTEN protein levels in DU145 and RWPE1 cells indicating that PTEN may mediate TGF‐β effects on cell proliferation. Knockdown of PTEN in DU145 cells resulted in significant increase in cell proliferation which was not affected by TGF‐β isoforms. PTEN overexpression in PC3 cells inhibited cell proliferation. Knockdown of endogenous PTEN enhanced cell migration in DU145 cells, whereas PTEN overexpression reduced migration in PC3 cells and reduced phosphorylation of AKT in response to TGF‐β.

Conclusion

We conclude that PTEN plays a role in inhibitory effects of TGF‐β on cell proliferation whereas its absence may enhance TGF‐β effects on activation of PI3‐kinase pathway and cell migration.
On the average‐case complexity of Shellsort
Authors: Vitányi Paul
Published: January 2018

We prove a lower bound expressed in the increment sequence on the average‐case complexity of the number of inversions of Shellsort. This lower bound is sharp in every case where it could be checked. A special case of this lower bound yields the general Jiang‐Li‐Vitányi lower bound. We obtain new results, for example, determining the average‐case complexity precisely in the Yao‐Janson‐Knuth 3‐pass case.
Security‐aware SaaS placement using swarm intelligence
Authors: Mezni Haithem , Sellami Mokhtar , Kouki Jaber
Published: January 2018

Cloud computing has emerged as a new powerful service delivery model to cope with resource challenges and to offer various on‐demand services (eg, software, storage, network, etc.). Software as a Service (SaaS) is one of the most popular service models. To meet the increasing demands of users, SaaS can be offered in a composite form. Although this approach offers some advantages like flexibility and reusability, it raises a question about how to manage composite SaaS in the distributed and the highly dynamic cloud environment. In this paper, we address one of the major SaaS resource management issues referred to as SaaS placement problem. As existing efforts only focus on SaaS placement problem from the perspective of resources utilization to optimize SaaS performance and minimize resource usage, in this paper, we also incorporate security concerns in SaaS placement strategy. In fact, security risk is one of the major factors influencing the efficiency of the composite SaaS. We adopt a multi‐swarm variant of particle swarm optimization to propose a security‐aware SaaS placement method. Also, a cooperative learning strategy is hybridized to the placement algorithm, which makes information of best candidate servers be used more effectively to generate better placement plan. Experiments show that our solution outperforms existing SaaS placement approaches.
Merging K‐means with hierarchical clustering for identifying general‐shaped groups
Authors: Peterson Anna D. , Ghosh Arka P. , Maitra Ranjan
Published: January 2018

Clustering partitions a dataset such that observations placed together in a group are similar but different from those in other groups. Hierarchical and K‐means clustering are two approaches but have different strengths and weaknesses. For instance, hierarchical clustering identifies groups in a tree‐like structure but suffers from computational complexity in large datasets, while K‐means clustering is efficient but designed to identify homogeneous spherically shaped clusters. We present a hybrid non‐parametric clustering approach that amalgamates the two methods to identify general‐shaped clusters and that can be applied to larger datasets. Specifically, we first partition the dataset into spherical groups using K‐means. We next merge these groups using hierarchical methods with a data‐driven distance measure as a stopping criterion. Our proposal has the potential to reveal groups with general shapes and structure in a dataset. We demonstrate good performance on several simulated and real datasets. Copyright © 2018 John Wiley & Sons, Ltd.
Modeling the biomechanics of the human cornea accounting for local variations of the collagen fibril architecture
Authors: Montanino Andrea , Gizzi Alessio , Vasta Marcello , Angelillo Maurizio , Pandolfi Anna
Published: January 2018

We present a finite element model of the human cornea describing the in‐plane organization of the stromal collagen, modified variously to include features of the collagen architecture. We investigate numerically the implication of the local organization of collagen in the stroma on the response of the human cornea to mechanical tests. We compare four different models by simulating three ideal mechanical tests, i. e., the ex‐vivo inflation test, the in‐vivo probe indentation, and the in‐vivo air puff tests. Numerical results show slight differences between the models in terms of global response and stress distribution. Differences in the overall mechanical response are observed in dynamic tests, while quasi‐static tests are not able to differentiate between the models. Stress distributions differ markedly when a variation of the shear stiffness across the thickness is considered. We conclude that the actual architecture of the collagen across the thickness of the cornea or at the limbus has a minor relevance from the mechanical point of view with respect to the main anisotropic orthogonal collagen structure that has been considered and acknowledged in the literature.
Metabolic evolution and a comparative omics analysis ofCorynebacterium glutamicumfor putrescine production
Authors: Li Zhen , Shen Yu-Ping , Jiang Xuan-Long , Feng Li-Shen , Liu Jian-Zhong
Published: January 2018

Putrescine is widely used in the industrial production of bioplastics, pharmaceuticals, agrochemicals, and surfactants. Because the highest titer of putrescine is much lower than that of its precursor l-ornithine reported in microorganisms to date, further work is needed to increase putrescine production in Corynebacterium glutamicum. We first compared 7 ornithine decarboxylase genes and found that the Enterobacter cloacae ornithine decarboxylase gene speC1 was most suitable for putrescine production in C. glutamicum. Increasing NADPH availability and blocking putrescine oxidation and acetylation were chosen as targets for metabolic engineering. The putrescine producer C. glutamicum PUT4 was first constructed by deleting puo, butA and snaA genes, and replacing the fabG gene with E. cloacae speC1. After adaptive evolution with C. glutamicum PUT4, the evolved strain C. glutamicum PUT-ALE, which produced an 96% higher amount of putrescine compared to the parent strain, was obtained. The whole genome resequencing indicates that the SNPs located in the odhA coding region may be associated with putrescine production. The comparative proteomic analysis reveals that the pentose phosphate and anaplerotic pathway, the glyoxylate cycle, and the ornithine biosynthetic pathway were upregulated in the evolved strain C. glutamicum PUT-ALE. The aspartate family, aromatic, and branched chain amino acid and fatty acid biosynthetic pathways were also observed to be downregulated in C. glutamicum PUT-ALE. Reducing OdhA activity by replacing the odhA native start codon GTG with TTG and overexpression of cgmA or pyc458 further improved putrescine production. Repressing the carB, ilvH, ilvB and aroE expression via CRISPRi also increased putrescine production by 5, 9, 16 and 19%, respectively.
The Mexican Drug War and Early-Life Health: The Impact of Violent Crime on Birth Outcomes
Authors: Brown Ryan
Published: January 2018

This study examines the relationship between exposure to violent crime in utero and birth weight using longitudinal data from a household survey conducted in Mexico. Controlling for selective migration and fertility, the results suggest that early gestational exposure to the recent escalation of the Mexican Drug War is associated with a substantial decrease in birth weight. This association is especially pronounced among children born to mothers of low socioeconomic status and among children born to mothers who score poorly on a mental health index.
Going it Alone: A Scoping Review of Unbefriended Older Adults
Authors: Chamberlain Stephanie , Baik Sol , Estabrooks Carole
Published: January 2018

Les personnes âgées dont la capacité de prise de décision est réduite et qui n’ont pas de soutien familial ou d’amis pour les aider à compenser ces déficits sont dites « solitaires » et nécessitent un tuteur public. Le but de cette étude était de recenser les publications avec comités de pairs et la littérature grise afin d’examiner la portée des travaux de recherches réalisés jusqu’à ce jour concernant les personnes âgées solitaires au Canada et aux États-Unis. Nous n’avons recensé que peu d’études sur ce sujet. Aucune étude ou rapport canadien n’a été trouvé. Les personnes âgées solitaires étaient plus avancées en âge, sans enfants ou avec peu d’enfants, et leurs troubles cognitifs étaient plus sévères, comparativement aux personnes âgées non solitaires. Ces résultats démontrent une rareté des études sur les personnes âgées solitaires. Il est urgent que davantage de recherches soient réalisées avec des collectes de données standardisées concernant la tutelle chez les personnes âgées solitaires afin de faciliter la réalisation d’études sur la prévalence de la tutelle publique au Canada.
Cancer pain management needs and perspectives of patients from Chinese backgrounds: a systematic review of the Chinese and English literature
Authors: Xu Xiangfeng , Luckett Tim , Wang Alex Yueping , Lovell Melanie , Phillips Jane L.
Published: January 2018

Objective

More than half of all cancer patients experience unrelieved pain. Culture can significantly affect patients’ cancer pain-related beliefs and behaviors. Little is known about cultural impact on Chinese cancer patients’ pain management. The objective of this review was to describe pain management experiences of cancer patients from Chinese backgrounds and to identify barriers affecting their pain management.

Method

A systematic review was conducted adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included if they reported pain management experiences of adult cancer patients from Chinese backgrounds. Five databases were searched for peer-reviewed articles published in English or Chinese journals between1990 and 2015. The quality of included studies was assessed using Joanna Briggs Institution's appraisal tools.

Results

Of 3,904 identified records, 23 articles met criteria and provided primary data from 6,110 patients. Suboptimal analgesic use, delays in receiving treatment, reluctance to report pain, and/or poor adherence to prescribed analgesics contributed to the patients’ inadequate pain control. Patient-related barriers included fatalism, desire to be good, low pain control belief, pain endurance beliefs, and negative effect beliefs. Patients and family shared barriers about fear of addiction and concerns on analgesic side effects and disease progression. Health professional–related barriers were poor communication, ineffective management of pain, and analgesic side effects. Healthcare system–related barriers included limited access to analgesics and/or after hour pain services and lack of health insurance.

Significance of results

Chinese cancer patients’ misconceptions regarding pain and analgesics may present as the main barriers to optimal pain relief. Findings of this review may inform health interventions to improve cancer pain management outcomes for patients from Chinese backgrounds. Future studies on patients’ nonpharmacology intervention-related experiences are required to inform multidisciplinary and biopsychosocial approaches for culturally appropriate pain management.