bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Friction-Reducing Agent for Slickwater Fracturing Treatments
Authors: Ibrahim Ahmed F. , Nasr-El-Din Hisham A. , Rabie Ahmed , Lin Genyao , Zhou Jian , Qu Qi
Published: April 2016

Friction reducers (FRs) represent an essential component in any slickwater fracturing fluid. While the majority of the previous research focused on evaluating the friction-reduction performance of these chemicals, only a few studies addressed the potential damage these chemical can cause to the formation.

Because of the polymeric nature of these chemicals (typically PAM, polyacrylamide), a friction reducer can either filter out onto the surface of the formation or penetrate deeply to plug the pores. In addition, breaking these polymers at temperatures lower than 200°F remains a problem. This work introduces a new and non-damaging friction reducer that can be a replacement for liner gel with enhanced proppant-carrying capacity.

Friction-reduction performance, proppant settling, viscosity, and coreflood studies were conducted with the following objectives: (1) investigate the effect of using the new FR on the permeability of tight sandstone formation compared to two conventional FRs, (2) test the performance of the new FR in different salinity environments from fresh to saline water, and (3) examine the effectiveness of breaking the new FR using different breakers.

The friction reduction of the new chemical was higher than 65% in fresh water or 2 wt% KCl in the presence of calcium chloride or choline chloride. The presence of 1 gpt of different types of breaker did not affect the friction reduction performance. The friction-reduction of 1 gpt of the new FR1 was higher than the guar-based FR3 at load of 4 gpt at the same conditions. The results also showed that the new friction reducer is easily breakable in any of the three tested breakers: ammonium persulfate, sodium persulfate, and hydrogen peroxide. Among the three, ammonium persulfate was the most efficient breaker. Static and dynamic proppant settling tests indicated a superior performance of FR1 compared to another conventional polyacrylamide friction reducer (FR2).

Coreflood experiments showed that the new friction reducer FR1 did not result in any residual damage to the formation permeability compared to 10 and 7% damage when the other two conventional friction reducers FR2 and FR3 were tested, respectively. Coreflood tests also showed that the new friction reducer is breakable using a weaker breaker such as sodium bromate with a minimum of 2.5% damage. The results showed that higher salinity did not affect the breakability of the new friction reducer.
Laboratory Evaluation of Multiphase Permeability Evolution in Tight Sandstones: Impact of Slickwater and Friction Reducers
Authors: Abaa Kelvin , Yilin-Wang John , Elsworth Derek , Ityokumbul Mku
Published: April 2016

Fracture fluid filtrate in low permeability sandstones may severely reduce the effective gas permeability.

This work investigates the role that fluid filtrate from slickwater fracturing has on rock-fluid and fluid-fluid interactions and to quantify the resulting multiphase permeability evolution during imbibition and drainage of the filtrate by means of specialized core testing techniques. Three suites of experiments were conducted. In the first suite of experiments, fluid leak-off tests were conducted on selected core samples to determine the extent of invasion and leakoff characteristics. In the second suite, multiphase relative permeability measurements were conducted on sandstone plugs saturated with fracture fluid filtrate. Pulse decay permeability techniques were employed to measure liquid and gas effective permeability for both drainage and imbibition cycles. These experiments capture dynamic permeability evolution during invasion and cleanup of the fracture fluid (slickwater). The final suite of experiments consist of adsorption flow tests to investigate, identify and quantify possible mechanisms of adsorption of the polymeric molecules of friction reducers present in the fluid filtrate to the pore walls of the rock sample. Imbibition tests and observation of contact angles were conducted to investigate possible changes in wettability.

Results from multiphase permeability flow tests show an irreversible reduction in end-point brine permeability and relative permeability with increasing concentration of friction reducer. Our results also show that effective gas permeability during drainage of the imbibed slickwater fluid is principally controlled by trapped gas saturation rather than by changes in interfacial tension. Adsorption flow tests identified adsorption of polymeric molecules of the friction reducer present in the fluid to the pore walls of the rock. The adsorption friction reducer increases wettability of the rock surface and results in the reduction of liquid relative permeability. The originality of this work is to derive a set of multiphase and petrophysical parameters from laboratory experiments that adequately captures multiphase permeability evolution specific to slickwater fluid systems, during imbibition and flowback. This will be useful in diagnosing formation damage from aqueous phase retention and optimizing fracturing fluid selection.
Potential Application of Atomic Force Microscopy in Characterization of Nano-pore Structures of Bakken Formation
Authors: Liu Kouqi , Ostadhassan Mehdi , Jabbari Hadi , Bubach Bailey
Published: April 2016

The Bakken Formation, an unconventional reservoir with very low permeability, is the main production zone in the Williston Basin, ND. Reliable numerical simulation of production performance of this formation requires an accurate description of the rock structures. Characterizing the pore structures is very important in understanding the storage capacity and also the mass transport potential of hydrocarbon. This has been the subject of number of studies by many researchers in the past few years. It has been found that the conventional methods are not applicable to characterize the nano-pore structures of shale formations due to several factors, including low resolution or the most important one, the potential damage to the tight sample during lab testing. This calls for methods which are specifically applicable to characterizing ultra-small pore structures.

In this paper, first we analyze mineral compositions of the samples that are from the Bakken Formation by XRD2. Then we use FESEM to analyze the microstructures of the samples and identify the existence of nano-pores. Then Atomic Force Microscopy (AFM) is acquired for more detailed characterization. We focused to show the great potential of this method in characterizing and quantifying the pore structures in the Bakken Formation. Finally future research work regarding how AFM can provide more insight to the shale nano world are noted.
Towards energy neutrality by optimising the activated sludge process of the WWTP Bochum-Ölbachtal
Authors: Marner S. T. , Schröter D. , Jardin N.
Published: April 2016

As a result of Ruhrverband's regularly performed energy audits the wastewater treatment plant (WWTP) Bochum-Ölbachtal shows substantial deficits concerning energy efficiency. Due to the energy consumption of internal recirculation, mixers and return activated sludge (RAS) pumping the existing pre-denitrification process configuration offers a specific energy consumption for biological treatment of 23 kWh (PE · a)−1. In order to optimise the energy situation and to improve the treatment efficiency, the process layout was changed completely to a three-stage step-feed process. By optimising the hydraulic conditions, it was possible to reconstruct the plant with a free flow throughout the whole biological treatment system without any additional pumping. The total investment costs for this process scheme were 3.9 million €. These costs could be partly offset against the wastewater charge paid (2.9 million €). Compared to the overall energy consumption before the process modification, today the energy consumption for biological treatment amounts to 12.4 kWh (PE · a)−1. The highest saving potential has been achieved by optimising mixing and reducing the energy demand for internal recirculation and RAS pumping. In the case of the WWTP Bochum-Ölbachtal, the modification of the treatment process not only results in an improved energy situation but also increased the treatment efficiency in such a way that the nitrogen concentration in the effluent could be constantly kept below 5 mg L−1 Ntot, which provides the basis for being exempted from the wastewater discharge for nitrogen. As a result of all these measures, the rate of self-sufficiency by using biogas from the digester in combined heat and power units has been increased substantially from 60% before process modifications to 97%. With the upcoming optimisation measures, a further increase of self-sufficiency is expected to finally achieve energy neutrality based on yearly averages. The example of the WWTP Bochum-Ölbachtal clearly shows that it is worthwhile to consider further measures for improving the energy and treatment efficiency, although most of the machinery was not fully depreciated at the time of implementing the new concept. It is also evident that the regular energy monitoring is essential for identifying potential for improvement. In this context and based on Ruhrverband's experience, it is highly suggested that energy audits are performed regularly for larger WWTPs.
The Players: Cells Involved in Glomerular Disease
Authors: Kitching A. Richard , Hutton Holly L.
Published: April 2016

Glomerular diseases are common and important. They can arise from systemic inflammatory or metabolic diseases that affect the kidney. Alternately, they are caused primarily by local glomerular abnormalities, including genetic diseases. Both intrinsic glomerular cells and leukocytes are critical to the healthy glomerulus and to glomerular dysregulation in disease. Mesangial cells, endothelial cells, podocytes, and parietal epithelial cells within the glomerulus all play unique and specialized roles. Although a specific disease often primarily affects a particular cell type, the close proximity, and interdependent functions and interactions between cells mean that even diseases affecting one cell type usually indirectly influence others. In addition to those cells intrinsic to the glomerulus, leukocytes patrol the glomerulus in health and mediate injury in disease. Distinct leukocyte types and subsets are present, with some being involved in different ways in an individual glomerular disease. Cells of the innate and adaptive immune systems are important, directing systemic immune and inflammatory responses, locally mediating injury, and potentially dampening inflammation and facilitating repair. The advent of new genetic and molecular techniques, and new disease models means that we better understand both the basic biology of the glomerulus and the pathogenesis of glomerular disease. This understanding should lead to better diagnostic techniques, biomarkers, and predictors of prognosis, disease severity, and relapse. With this knowledge comes the promise of better therapies in the future, directed toward halting pathways of injury and fibrosis, or interrupting the underlying pathophysiology of the individual diseases that lead to significant and progressive glomerular disease.
Synthesis, structural characterization and myorelaxant activity of 4-naphthylhexahydroquinoline derivatives containing different ester groups
Authors: Gündüz Miyase , Albayrak Emine , İşli Fatma , Fincan Gökçe , Yildirim Şeniz , Şimşek Rahime , Şafak Cihat , Sarioğlu Yusuf , Yidirim Sema , Butcher Ray
Published: April 2016

The present study reports the synthesis, structural characterization and
myorelaxant activity evaluation of a series of 16 novel
4-naphthyl-hexahydroquinoline derivatives. The compounds were achieved by
one-pot microwave-assisted method via a modified Hantzsch reaction. The
structures of the compounds were confirmed by various spectral methods like
IR, 1D-2D NMR techniques and mass analysis. X-ray studies of compound 10
provided further evidence for the proposed structure. To evaluate their
myorelaxant activities, the Emax and pD2 values of the compounds and
nifedipine were determined on isolated rabbit gastric fundus smooth muscle
strips. The obtained results indicated that introduction of long chain alkyl
groups such as 2-methoxyethyl or 2-(methacryloyloxy)ethyl moiety to the ester
group led to the most active compounds.
Prognostic Classification Factors Associated With Development of Multiple Autoantibodies, Dysglycemia, and Type 1 Diabetes—A Recursive Partitioning Analysis
Authors: Xu Ping , Krischer Jeffrey P. ,   on behalf of the Type 1 Diabetes TrialNet Study Group
Published: April 2016

OBJECTIVE

To define prognostic classification factors associated with the progression from single to multiple autoantibodies, multiple autoantibodies to dysglycemia, and dysglycemia to type 1 diabetes onset in relatives of individuals with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Three distinct cohorts of subjects from the Type 1 Diabetes TrialNet Pathway to Prevention Study were investigated separately. A recursive partitioning analysis (RPA) was used to determine the risk classes. Clinical characteristics, including genotype, antibody titers, and metabolic markers were analyzed.

RESULTS

Age and GAD65 autoantibody (GAD65Ab) titers defined three risk classes for progression from single to multiple autoantibodies. The 5-year risk was 11% for those subjects >16 years of age with low GAD65Ab titers, 29% for those ≤16 years of age with low GAD65Ab titers, and 45% for those subjects with high GAD65Ab titers regardless of age. Progression to dysglycemia was associated with islet antigen 2 Ab titers, and 2-h glucose and fasting C-peptide levels. The 5-year risk is 28%, 39%, and 51% for respective risk classes defined by the three predictors. Progression to type 1 diabetes was associated with the number of positive autoantibodies, peak C-peptide level, HbA1c level, and age. Four risk classes defined by RPA had a 5-year risk of 9%, 33%, 62%, and 80%, respectively.

CONCLUSIONS

The use of RPA offered a new classification approach that could predict the timing of transitions from one preclinical stage to the next in the development of type 1 diabetes. Using these RPA classes, new prevention techniques can be tailored based on the individual prognostic risk characteristics at different preclinical stages.
Being by myself and believing in us: the experience of pregnancy and childbirth during an intimate partner's military deployment
Authors: Patchell Christian , Snelgrove-Clarke Erna , Carson Glenda , Tamlyn Deborah
Published: April 2016

Introduction: Pregnancy and childbirth are life-altering events. For military families, pregnancy and childbirth can occur in tandem with the family's experience of a military deployment. The central issue is that an overseas deployment of an intimate partner introduces unique stressors and responsibilities that can challenge a pregnancy and increase the risk of preterm delivery and postpartum depression. The objective of this study was to extend current understanding, from the perspective of women in Canadian military families of how pregnancy and childbirth are experienced during an intimate partner's military deployment and of how supports and resources shaped the experience. Methods: This study was conducted in eastern Canada by interviewing women in Canadian military families who had experienced pregnancy or childbirth during an intimate partner's deployment in the past two to five years. Valid consent for confidential participation and demographic information were collected prior to the interviews. A descriptive phenomenological approach allowed for women's stories to be explored and for the over-arching theme ‘being by myself and believing in us’ to be uncovered. Results: The meaning of the experience of pregnancy, childbirth, and deployment was both integrated and opposing. Women experienced simultaneously “being by myself,” physically alone or in a world that did not understand their experience, and “believing in us,” the possibility of having a child, of a partner's return, and of becoming a family. Sub-themes that provided further understanding of the experience included: working it out time wise, longing for togetherness, appreciating technology, protecting us, knowing that somebody is there, and homecoming. Discussion: The implications of this study include laying a foundation for future research and guiding improvements for supportive perinatal care.
RETRACTED: Toxicity Evaluation of New Engineered Nanomaterials in Zebrafish
Authors: Brundo Maria V. , Pecoraro Roberta , Marino Fabio , Salvaggio Antonio , Tibullo Daniele , Saccone Salvatore , Bramanti Vincenzo , Buccheri Maria A. , Impellizzeri Giuliana , Scuderi Viviana , Zimbone Massimo , Privitera Vittorio
Published: April 2016

The effect of the nanoparticles on the marine organisms, depends on their size, chemical composition, surface structure, solubility and shape. In order to take advantage from their activity, preserving the surrounding environment from a possible pollution, we are trying to trap the nanoparticles into new nanomaterials. The nanomaterials tested were synthesized proposing a ground-breaking approach by an upside-down vision of the Au/TiO2 nano-system to avoid the release of nanoparticles. The system was synthesized by wrapping Au nanoparticles with a thin layer of TiO2. The non-toxicity of the nano-system was established by testing the effect of the material on zebrafish larvae. Danio rerio o zebrafish was considered an excellent model for the environmental biomonitoring of aquatic environments and the Zebrafish Embryo Toxicity Test (ZFET) is considered an alternative method of animal test. For this reason zebrafish larvae were exposed to different concentrations of nanoparticles of TiO2 and Au and new nanomaterials. As biomarkers of exposure, we evaluated the expression of metallothioneins by immunohistochemistry analysis and western blotting analysis also. The results obtained by toxicity test showed that neither mortality as well as sublethal effects were induced by the different nanomaterials and nanoparticles tested. Only zebrafish larvae exposed to free Au nanoparticles showed a different response to anti-MT antibody. In fact, the immunolocalization analysis highlighted an increase of the metallothioneins synthesis.
Genetic Diversity in Apple Fruit Moth Indicate Different Clusters in the Two Most Important Apple Growing Regions of Norway
Authors: Elameen Abdelhameed , Eiken Hans , Knudsen Geir
Published: April 2016

The apple fruit moth (Argyresthia conjugella (A. conjugella)) in Norway was first identified as a pest in apple production in 1899. We here report the first genetic analysis of A. conjugella using molecular markers. Amplified fragment length polymorphism (AFLP) analysis was applied to 95 individuals from six different locations in the two most important apple-growing regions of Norway. Five AFLP primer combinations gave 410 clear polymorphic bands that distinguished all the individuals. Further genetic analysis using the Dice coefficient, Principal Coordinate analysis (PCO) and Bayesian analyses suggested clustering of the individuals into two main groups showing substantial genetic distance. Analysis of molecular variance (AMOVA) revealed greater variation among populations (77.94%) than within populations (22.06%) and significant and high FST values were determined between the two major regions (Distance = 230 km, FST = 0.780). AFLP analysis revealed low to moderate genetic diversity in our population sample from Norway (Average: 0.31 expected heterozygosity). The positive significant correlation between the geographic and the molecular data (r2 = 0.6700) indicate that genetic differences between the two major regions may be due to geographical barriers such as high mountain plateaus (Hardangervidda) in addition to isolation by distance (IBD).
Correction on Liu, X.; Jiang, A.; Xu, N.; Xue, J. Increment Entropy as a Measure of Complexity for Time Series. Entropy 2016, 18, 22
Authors: Liu Xiaofeng , Jiang Aimin , Xu Ning , Xue Jianru
Published: April 2016

The authors wish to make the following correction to their paper [1].[...]
Epigenetic Biomarkers of Preterm Birth and Its Risk Factors
Authors: Knight Anna , Smith Alicia
Published: April 2016

A biomarker is a biological measure predictive of a normal or pathogenic process or response. Biomarkers are often useful for making clinical decisions and determining treatment course. One area where such biomarkers would be particularly useful is in identifying women at risk for preterm delivery and related pregnancy complications. Neonates born preterm have significant morbidity and mortality, both in the perinatal period and throughout the life course, and identifying women at risk of delivering preterm may allow for targeted interventions to prevent or delay preterm birth (PTB). In addition to identifying those at increased risk for preterm birth, biomarkers may be able to distinguish neonates at particular risk for future complications due to modifiable environmental factors, such as maternal smoking or alcohol use during pregnancy. Currently, there are no such biomarkers available, though candidate gene and epigenome-wide association studies have identified DNA methylation differences associated with PTB, its risk factors and its long-term outcomes. Further biomarker development is crucial to reducing the health burden associated with adverse intrauterine conditions and preterm birth, and the results of recent DNA methylation studies may advance that goal.
An Overview of the Use of Absolute Dating Techniques in Ancient Construction Materials
Authors: Sanjurjo-Sánchez Jorge
Published: April 2016

The reconstruction of the chronology of historical buildings is a tricky issue, as usually there are not historical documents that allow the assessment of construction phases, and some materials are hardly reliable for the use of dating techniques (e.g., stone). However, in the last two decades, important advances on the use of absolute dating methods on building materials have increased the possibilities of reconstructing building chronologies, although some advances are still scarcely known among archaeologists and architects. Recent studies performed on several kinds of mortars, fired bricks, mud-bricks, and even stone surfaces have shown that it is possible to date them. Both radiocarbon and luminescence dating have been the most frequently used techniques but others such as archaeomagnetism can also be used in some cases. This paper intends to give an overview of the recent achievements on the use of absolute dating techniques for building materials.
Pain Assessment–Can it be Done with a Computerised System? A Systematic Review and Meta-Analysis
Authors: Pombo Nuno , Garcia Nuno , Bousson Kouamana , Spinsante Susanna , Chorbev Ivan
Published: April 2016

Background: Mobile and web technologies are becoming increasingly used to support the treatment of chronic pain conditions. However, the subjectivity of pain perception makes its management and evaluation very difficult. Pain treatment requires a multi-dimensional approach (e.g., sensory, affective, cognitive) whence the evidence of technology effects across dimensions is lacking. This study aims to describe computerised monitoring systems and to suggest a methodology, based on statistical analysis, to evaluate their effects on pain assessment. Methods: We conducted a review of the English-language literature about computerised systems related to chronic pain complaints that included data collected via mobile devices or Internet, published since 2000 in three relevant bibliographical databases such as BioMed Central, PubMed Central and ScienceDirect. The extracted data include: objective and duration of the study, age and condition of the participants, and type of collected information (e.g., questionnaires, scales). Results: Sixty-two studies were included, encompassing 13,338 participants. A total of 50 (81%) studies related to mobile systems, and 12 (19%) related to web-based systems. Technology and pen-and-paper approaches presented equivalent outcomes related with pain intensity. Conclusions: The adoption of technology was revealed as accurate and feasible as pen-and-paper methods. The proposed assessment model based on data fusion combined with a qualitative assessment method was revealed to be suitable. Data integration raises several concerns and challenges to the design, development and application of monitoring systems applied to pain.
Restoration in Its Natural Context: How Ecological Momentary Assessment Can Advance Restoration Research
Authors: Beute Femke , De Kort Yvonne , IJsselsteijn Wijnand
Published: April 2016

More and more people use self-tracking technologies to track their psychological states, physiology, and behaviors to gain a better understanding of themselves or to achieve a certain goal. Ecological Momentary Assessment (EMA) also offers an excellent opportunity for restorative environments research, which examines how our physical environment (especially nature) can positively influence health and wellbeing. It enables investigating restorative health effects in everyday life, providing not only high ecological validity but also opportunities to study in more detail the dynamic processes playing out over time on recovery, thereby bridging the gap between laboratory (i.e., short-term effects) and epidemiological (long-term effects) research. We have identified four main areas in which self-tracking could help advance restoration research: (1) capturing a rich set of environment types and restorative characteristics; (2) distinguishing intra-individual from inter-individual effects; (3) bridging the gap between laboratory and epidemiological research; and (4) advancing theoretical insights by measuring a more broad range of effects in everyday life. This paper briefly introduces restorative environments research, then reviews the state of the art of self-tracking technologies and methodologies, discusses how these can be implemented to advance restoration research, and presents some examples of pioneering work in this area.
Long-Term Weight Change after Initiating Second-Generation Antidepressants
Authors: Arterburn David , Sofer Tamar , Boudreau Denise , Bogart Andy , Westbrook Emily , Theis Mary , Simon Greg , Haneuse Sebastien
Published: April 2016

(1) Objective: To examine the relationship between the choice of second-generation antidepressant drug treatment and long-term weight change; (2) Methods: We conducted a retrospective cohort study to investigate the relationship between choice of antidepressant medication and weight change at two years among adult patients with a new antidepressant treatment episode between January, 2006 and October, 2009 in a large health system in Washington State. Medication use, encounters, diagnoses, height, and weight were collected from electronic databases. We modeled change in weight and BMI at two years after initiation of treatment using inverse probability weighted linear regression models that adjusted for potential confounders. Fluoxetine was the reference treatment; (3) Results: In intent-to-treat analyses, non-smokers who initiated bupropion treatment on average lost 7.1 lbs compared to fluoxetine users who were non-smokers (95% CI: −11.3, −2.8; p-value < 0.01); smokers who initiated bupropion treatment gained on average 2.2 lbs compared to fluoxetine users who were smokers (95% CI: −2.3, 6.8; p-value = 0.33). Changes in weight associated with all other antidepressant medications were not significantly different than fluoxetine, except for sertraline users, who gained an average of 5.9 lbs compared to fluoxetine users (95% CI: 0.8, 10.9; p-value = 0.02); (4) Conclusion: Antidepressant drug therapy is significantly associated with long-term weight change at two years. Bupropion may be considered as the first-line drug of choice for overweight and obese patients unless there are other existing contraindications.
The Impact of Palmaris Longus Muscle on Function in Sports: An Explorative Study in Elite Tennis Players and Recreational Athletes
Authors: Vercruyssen Julie , Scafoglieri Aldo , Cattrysse Erik
Published: April 2016

The Palmaris longus muscle can be absent unilateral or bilateral in about 22.4% of human beings. The aim of this study is to investigate whether the presence of the Palmaris longus muscle is associated with an advantage to handgrip in elite tennis players compared to recreational athletes. Sixty people participated in this study, thirty elite tennis players and thirty recreational athletes. The presence of the Palmaris longus muscle was first assessed using different tests. Grip strength and fatigue resistance were measured by an electronic hand dynamometer. Proprioception was registered by the Flock of Birds electromagnetic tracking system. Three tests were set up for measuring proprioception: joint position sense, kinesthesia, and joint motion sense. Several hand movements were conducted with the aim to correctly reposition the joint angle. Results demonstrate a higher presence of the Palmaris longus muscle in elite tennis players, but this was not significant. Maximal grip strength was correlated with gender and only on the dominant side; it was also correlated with age. Fatigue resistance showed only on the non-dominant side; a significant difference in elite and recreational athletes. In proprioception there was no correlation with elite and recreational athletes or the presence of the Palmaris longus muscle.
Effects of Apatite Cement Containing Atelocollagen on Attachment to and Proliferation and Differentiation of MC3T3-E1 Osteoblastic Cells
Authors: Takechi Masaaki , Ninomiya Yoshiaki , Ohta Kouji , Tada Misato , Sasaki Kazuki , Rahman Mohammad , Ohta Akira , Tsuru Kanji , Ishikawa Kunio
Published: April 2016

To improve the osteoconductivity of apatite cement (AC) for reconstruction of bone defects after oral maxillofacial surgery, we previously fabricated AC containing atelocollagen (AC(ate)). In the present study, we examined the initial attachment, proliferation and differentiation of mouse osteoblastic cells (MC3T3-E1 cells) on the surface of conventional AC (c-AC), AC(ate) and a plastic cell dish. The number of osteoblastic cells showing initial attachment to AC(ate) was greater than those attached to c-AC and similar to the number attached to the plastic cell wells. We also found that osteoblastic cells were well spread and increased their number on AC(ate) in comparison with c-AC and the wells without specimens, while the amount of procollagen type I carboxy-terminal peptide (PIPC) produced in osteoblastic cells after three days on AC(ate) was greater as compared to the others. There was no significant difference in regard to alkaline phosphatase (ALP) activity and osteocalcin production by osteoblastic cells among the three surface types after three and six days. However, after 12 days, ALP activity and the produced osteocalcin were greater with AC(ate). In conclusion, AC(ate) may be a useful material with high osteoconductivity for reconstruction of bone defects after oral maxillofacial surgery.
Corrosion Resistance of the Superhydrophobic Mg(OH)2/Mg-Al Layered Double Hydroxide Coatings on Magnesium Alloys
Authors: Zhang Fen , Zhang Changlei , Zeng Rongchang , Song Liang , Guo Lian , Huang Xiaowen
Published: April 2016

Coatings of the Mg(OH)2/Mg-Al layered double hydroxide (LDH) composite were formed by a combined co-precipitation method and hydrothermal process on the AZ31 alloy substrate in alkaline condition. Subsequently, a superhydrophobic surface was successfully constructed to modify the composite coatings on the AZ31 alloy substrate using stearic acid. The characteristics of the composite coatings were investigated by means of X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electronic microscope (SEM) and contact angle (CA). The corrosion resistance of the coatings was assessed by potentiodynamic polarization, the electrochemical impedance spectrum (EIS), the test of hydrogen evolution and the immersion test. The results showed that the superhydrophobic coatings considerably improved the corrosion resistant performance of the LDH coatings on the AZ31 alloy substrate.
Gold Nanomaterial Uptake from Soil Is Not Increased by Arbuscular Mycorrhizal Colonization of Solanum Lycopersicum (Tomato)
Authors: Judy Jonathan , Kirby Jason , McLaughlin Mike , Cavagnaro Timothy , Bertsch Paul
Published: April 2016

Bioaccumulation of engineered nanomaterials (ENMs) by plants has been demonstrated in numerous studies over the past 5–10 years. However, the overwhelming majority of these studies were conducted using hydroponic systems and the degree to which the addition of the biological and chemical components present in the soil might fundamentally alter the potential of plant bioaccumulation of ENMs is unclear. Here, we used two genotypes of Solanum lycopersicum (tomato), reduced mycorrhizal colonization (rmc), a mutant which does not allow arbuscular mycorrhizal fungi (AMF) colonization, and its progenitor, 76R, to examine how colonization by AMF alters trends of gold ENM bioaccumulation from a natural soil. Gold was taken up and bioaccumulated by plants of both genotypes. Gold concentrations were significantly higher in the rmc treatment although this was likely attributable to the large differences in biomass between the 76R and rmc plants. Regardless, there was little evidence that AMF played a significant role in trafficking Au ENMs into the plants. Furthermore, despite very low NH4NO3 extractable Au concentrations, Au accumulated at the root-soil interface. Although this observation would seem to suggest that ENMs may have potential to influence this particularly biologically active and important soil compartment, we observed no evidence of this here, as the 76R plants developed a robust AMF symbiosis despite accumulation of Au ENMs at the rhizoplane.
Cationic Nanoparticles Assembled from Natural-Based Steroid Lipid for Improved Intracellular Transport of siRNA and pDNA
Authors: Sheng Ruilong , Zhuang Xiaoqing , Wang Zhao , Cao Amin , Lin Kaili , Zhu Julian
Published: April 2016

Developing new functional biomaterials from biocompatible natural-based resources for gene/drug delivery has attracted increasing attention in recent years. In this work, we prepared a series of cationic nanoparticles (Diosarg-DOPE NPs) by assembly of a natural steroid diosgenin-based cationic lipid (Diosarg) with commercially-available helper lipid 1,2-dioleoyl-sn-glycero-3-phosphorethanolamine (DOPE). These cationic Diosarg-DOPE NPs were able to efficiently bind siRNA and plasmid DNA (pDNA) via electrostatic interactions to form stable, nano-sized cationic lipid nanoparticles instead of lamellar vesicles in aqueous solution. The average particle size, zeta potentials and morphologies of the siRNA and pDNA complexes of the Diosarg-DOPE NPs were examined. The in vitro cytotoxicity of NPs depends on the dose and assembly ratio of the Diosarg and DOPE. Notably, the intracellular transportation efficacy of the exogenesis siRNA and pDNA could be greatly improved by using the Diosarg-DOPE NPs as the cargoes in H1299 cell line. The results demonstrated that the self-assembled Diosarg-DOPE NPs could achieve much higher intracellular transport efficiency for siRNA or pDNA than the cationic lipid Diosarg, indicating that the synergetic effect of different functional lipid components may benefit the development of high efficiency nano-scaled gene carriers. Moreover, it could be noted that the traditional “lysosome localization” involved in the intracellular trafficking of the Diosarg and Diosarg-DOPE NPs, indicating the co-assembly of helper lipid DOPE, might not significantly affect the intracellular localization features of the cationic lipids.
Enzyme-Catalyzed Synthesis of Water-Soluble Conjugated Poly[2-(3-thienyl)-Ethoxy-4-Butylsulfonate]
Authors: Zhao Yun , Zhu Hongyan , Wang Xinyang , Liu Yingying , Wu Xiang , Zhou Heyuan , Ni Zhonghai
Published: April 2016

An environmentally friendly water-soluble conjugated polythiophene poly[2-(3-thienyl)-ethoxy-4-butylsulfonate] (PTEBS) has been found to be effective for making hybrid solar cells. In this work, we first report the enzyme-catalyzed polymerization of (3-thienyl)-ethoxy-4-butylsulfonate (TEBS) using horseradish peroxidase (HRP) enzyme as a catalyst and hydrogen peroxide (H2O2) as an oxidant in an aqueous buffer. This enzyme-catalyzed polymerization is a “green synthesis process” for the synthesis of water-soluble conjugated PTEBS, the benefits of which include a simple setting, high yields, and an environmentally friendly route. Fourier transform infrared spectra (FTIR) and UV–Vis absorption spectra confirm the successful enzyme-catalyzed polymerization of TEBS. The thermo gravimetric (TG) data show the obtained PTEBS is stable over a fairly high range of temperatures. The present PTEBS has a good solubility in water and ethanol, and photoluminescence quenching of PTEBS/titanium dioxide (TiO2) composite implies that the excitons dissociate and separate successfully at the interface of PTEBS and TiO2, which help to build solar cells using green processing methods.
Towards A Self Adaptive System for Social Wellness
Authors: Khattak Asad , Khan Wajahat , Pervez Zeeshan , Iqbal Farkhund , Lee Sungyoung
Published: April 2016

Advancements in science and technology have highlighted the importance of robust healthcare services, lifestyle services and personalized recommendations. For this purpose patient daily life activity recognition, profile information, and patient personal experience are required. In this research work we focus on the improvement in general health and life status of the elderly through the use of an innovative services to align dietary intake with daily life and health activity information. Dynamic provisioning of personalized healthcare and life-care services are based on the patient daily life activities recognized using smart phone. To achieve this, an ontology-based approach is proposed, where all the daily life activities and patient profile information are modeled in ontology. Then the semantic context is exploited with an inference mechanism that enables fine-grained situation analysis for personalized service recommendations. A generic system architecture is proposed that facilitates context information storage and exchange, profile information, and the newly recognized activities. The system exploits the patient’s situation using semantic inference and provides recommendations for appropriate nutrition and activity related services. The proposed system is extensively evaluated for the claims and for its dynamic nature. The experimental results are very encouraging and have shown better accuracy than the existing system. The proposed system has also performed better in terms of the system support for a dynamic knowledge-base and the personalized recommendations.
General Solution of the Extended Plate Model Including Diffusion, Slow Transfer Kinetics and Extra-Column Effects for Isocratic Chromatographic Elution
Authors: Baeza-Baeza Juan , García-Álvarez-Coque María
Published: April 2016

The plate model proposed by Martin and Synge has been used for the characterization of columns up-to-date. In this approach, the column is divided into a large number (N) of identical theoretical plates. Mobile phase transference between plates takes place in infinitesimal steps with mixing of the solutions in the adjacent plates during the flow. The plate height is related to the band broadening that occurs in the mixing process due to the microscopic heterogeneities in the mobile phase flow. According to the original Martin and Synge model, solutes reach the equilibrium instantaneously in each theoretical plate, where dispersion is produced by: (i) convection or mixing of the mobile phase reaching a theoretical plate with that existing in that plate; and (ii) the equilibrium of the solute that is partitioned between mobile phase and stationary phase. In this work, a general method is proposed to solve the problem of chromatographic elution by means of an extended plate model assuming slow mass transfer, longitudinal diffusion in both mobile phase and stationary phase, and the extra column dispersion. The final equation was validated by comparing the results with those obtained through the numerical simulation of the solute migration using the finite differential approach. Experimental data were also used to check the validity of the derived equations.
Exploring Gradients in Electrophoretic Separation and Preconcentration on Miniaturized Devices
Authors: Zhu Fanyi , Hayes Mark
Published: April 2016

Over the last two decades, miniaturization, integration, and automation have made microfluidic systems popular. Core to advances in microfluidics are numerous electrophoretic separation and preconcentration strategies, some finding their origins on bench-top systems. Among them, gradient-based strategies are especially effective in addressing sensitivity challenges. This review introduces several gradient-based techniques according to a broad definition, including conductivity, field, and concentration, organized by the method of gradient generation. Each technique is introduced and described, and recent seminal advances explored.
Conceptualizing the Limiting Issues Inhibiting Sustainability Embeddedness
Authors: Le Roux Catherine , Pretorius Marius
Published: April 2016

There can be little doubt that sustainability has become one of the most important issues in business in recent years. In spite of sustainability’s importance, there is agreement amongst leaders and practitioners that sustainability is not as embedded as desired. This study reports a framework on inhibitors that limit sustainability embeddedness in organizations. The framework can assist management to address the non-achievement antecedents of embeddedness specifically and holistically. This study obtained empirical data from employees on all management levels in a stock exchange-listed company. Through in-depth analysis in a case organization, valuable insights about embeddedness were inductively identified, interpreted and presented using descriptive labels, namely: “Professing What Is Right”; “Green Distraction”; the belief of “Not My Job”; “Firefighter”; the “Past Performance Anchor”; “Strategy Discourse” and “Harmony”—a mediator to sustainability embeddedness. All these were also found to be altered by the transformation of culture and the communication of the strategy message by sustainable leadership—the moderator. The findings were also corroborated by related and supporting literature as part of our contribution and pursuit for better understanding of this phenomenon.
Temporal Variations of Citizens’ Demands on Flood Damage Mitigation, Streamflow Quantity and Quality in the Korean Urban Watershed
Authors: Hong Chang-Yu , Chung Eun-Sung
Published: April 2016

Sustainable watershed management (SWM) can be achieved through recognition and reflection upon the values of citizens. Collaborative governance consisting of citizens is crucial for successful SWM. Collaborative governance definitely requires an active participatory decision-making process that reflects citizens’ preferences. Citizen preference also tends to substantially change with life pattern and life quality. These shifts can be caused by slight variations in both social priorities and personal preferences for SWM. Therefore, collaborative water governance must be frequently renewed in response to citizens’ values through the participatory framework. The An’yang Stream in South Korea is generally regarded as a representative urban stream restoration case that has been successfully led by collaborative governance. By conducting individual surveys with citizens on-site, this study addresses how citizens’ preferences of the stream’s management have changed between 2005 and 2015. In addition, this study used three quantitative hydrologic vulnerability indices: potential flood damage (PFD), potential streamflow depletion (PSD), and potential water quality deterioration (PWQD). They can spatially quantify citizen preference using the Analytic Hierarchy Process (AHP), which can systematically derive citizens’ subjective relative-weighted preferences. In the end, this study identified critical differences in priorities in regard to vulnerable areas between in 2005 and in 2015.
Metal Ion Activation of Clostridium sordellii Lethal Toxin and Clostridium difficile Toxin B
Authors: Genth Harald , Schelle Ilona , Just Ingo
Published: April 2016

Lethal Toxin from Clostridium sordellii (TcsL) and Toxin B from Clostridium difficile (TcdB) belong to the family of the “Large clostridial glycosylating toxins.” These toxins mono-O-glucosylate low molecular weight GTPases of the Rho and Ras families by exploiting UDP-glucose as a hexose donor. TcsL is casually involved in the toxic shock syndrome and the gas gangrene. TcdB—together with Toxin A (TcdA)—is causative for the pseudomembranous colitis (PMC). Here, we present evidence for the in vitro metal ion activation of the glucosyltransferase and the UDP-glucose hydrolysis activity of TcsL and TcdB. The following rating is found for activation by divalent metal ions: Mn2+ > Co2+ > Mg2+ >> Ca2+, Cu2+, Zn2+. TcsL and TcdB thus require divalent metal ions providing an octahedral coordination sphere. The EC50 values for TcsL were estimated at about 28 µM for Mn2+ and 180 µM for Mg2+. TcsL and TcdB further require co-stimulation by monovalent K+ (not by Na+). Finally, prebound divalent metal ions were dispensible for the cytopathic effects of TcsL and TcdB, leading to the conclusion that TcsL and TcdB recruit intracellular metal ions for activation of the glucosyltransferase activity. With regard to the intracellular metal ion concentrations, TcsL and TcdB are most likely activated by K+ and Mg2+ (rather than Mn2+) in mammalian target cells.
Can Rapid Assessments Predict the Biotic Condition of Restored Streams?
Authors: Doll Barbara , Jennings Gregory , Spooner Jean , Penrose David , Usset Joseph , Blackwell James , Fernandez Mark
Published: April 2016

Five rapid visual stream assessment methods were applied to 65 restored streams in North Carolina, and the results were correlated with measured macroinvertebrate community metrics to evaluate predictive ability. The USEPA Rapid Bioassessment Protocol (RBP), USDA Stream Visual Assessment Protocol (SVAP), Peterson’s Riparian Channel and Environmental Inventory (RCE), NCSU Eco-Geomorphological Assessment (EGA), and NCSU Stream Performance Assessment (SPA) were applied by teams with expertise in hydrology, fluvial geomorphology, and aquatic ecology. Predictions of most macroinvertebrate metrics were improved by re-weighting assessment variables using principal component analysis (PCA) and including watershed factors (e.g., size, slope, land use). The correlations of EGA, RCE, SPA and SVAP assessment results to macroinvertebrate metrics were most improved by variable re-weighting using PCA, while the correlations of RBP were most improved by adding watershed parameters. Akaike’s Information Criterion (AIC) indicates that PCA re-weighting including watershed parameters improves the predictor model for the total number of dominant EPT taxa more than using the sum total raw points for all five assessment methods. To demonstrate the application of the study results, a single-value index was generated for the RBP method using principal component regression (PCR) based on the EPT (Ephemeroptera, Plecoptera and Trichoptera) taxa metric.