bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Rheological Behavior of Viscoelastic Surfactants on Formation Damage in Carbonate Rocks
Authors: Kamal Muhammad Shahzad , Mahmoud Mohamed , Hanfi Mohammed
Published: August 2018

Viscoelastic surfactants (VES) are used in various oilfield applications such as matrix stimulation and enhanced oil recovery. The loss of surfactants during the propagation of VES could result in a significant reduction in the permeability of the rock (formation damage). The objective of the current work was to identify the effect of rheological behavior of the VES on the formation damage using core‐flooding experiments, nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM) analysis. A combination of core‐flooding, NMR, and SEM techniques was used to quantify and identify the location of formation damage in carbonate core samples. The viscosity and storage modulus strongly depend on the nature and concentration of salts. The viscosity increased by increasing the salt concentration up to a specific point (15 wt% CaCl2) and then starts decreasing. The VES formulations that displayed the maximum and minimum viscosities were used to identify the impact of rheological behavior on formation damage. Core‐flooding experiments were performed to assess the formation damage due to high‐viscosity and low‐viscosity VES formulations. The reduction in the permeability of carbonate rocks reaches more than 90% of the initial permeability. It was found that low‐viscosity VES caused more damage compared with high‐viscosity VES when they were used at constant concentrations. NMR and core‐flooding results revealed that the damage took place both in pore body and pore throat. However, most of the surfactant was retained at the pore throat.
New intraoperative imaging technologies: Innovating the surgeon’s eye toward surgical precision
Authors: Mascagni Pietro , Longo Fabio , Barberio Manuel , Seeliger Barbara , Agnus Vincent , Saccomandi Paola , Hostettler Alexandre , Marescaux Jacques , Diana Michele
Published: August 2018

Imaging is one of the pillars for the ongoing evolution of surgical oncology toward a precision paradigm. In the present overview, some established or emerging intraoperative imaging technologies are described in light of the vision and experience of our group in image‐guided surgery, focusing on digestive surgical oncology.
Lower expression of tumor microRNA‐26a is associated with higher recurrence in patients with hepatocellular carcinoma undergoing surgical treatment
Authors: Jones Keaton R. , Nabinger Sarah C. , Lee Sangbin , Sahu Smiti Snigdha , Althouse Sandra , Saxena Romil , Johnson Mathew S. , Chalasani Naga , Gawrieh Samer , Kota Janaiah
Published: August 2018

Background and Objectives

Hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV) exhibit lower tumor microRNA‐26a (miR‐26a) expression which is associated with worse outcomes. It is unknown if similar miR‐26a loss occurs in HCC developed in other liver diseases. We examined tumor miR‐26a expression and its impact on recurrence and mortality in a North American HCC cohort.

Methods

MiR‐26a levels from tumor and surrounding nontumor liver tissue in 186 subjects were collected. We defined lower tumor expression of miR‐26a as <1‐fold that of the adjacent nontumor liver tissue.

Results

Viral hepatitis (42%; 40% hepatitis C and 2% HBV), alcohol (19%), and nonalcoholic fatty liver disease (NAFLD) (18%) were the most common causes of liver disease. The prevalence of lower tumor miR‐26a expression was 68%, and it was evident in HCCs arising in all etiologies (viral hepatitis 60%, alcohol 61%, and NAFLD 76%). Subjects with lower tumor miR‐26a expression had significantly higher tumor recurrence (hazard ratio [HR], 2.45; 95% confidence interval [CI], 1.18 to 5.1; P = 0.016) and higher mortality of borderline significance (HR, 1.51; 95% CI, 0.94 to 2.41; P = 0.086).

Conclusion

Reduced miR‐26a expression is a common phenomenon in HCC arising in North American patients with different underlying liver diseases and may increase recurrence and mortality after surgery.
Fluorescent molecularly imprinted nanoparticles for selective and rapid detection of ciprofloxacin in aquaculture water
Authors: Wu Chunxia , Cheng Rujia , Wang Jixiang , Wang Yunyun , Jing Xuan , Chen Rongru , Sun Lin , Yan Yongsheng
Published: August 2018

Fluorescent molecularly imprinted nanoparticles have shown great promise in the field of chemical analysis or detection because of their high stability, selectivity, and sensitivity. In this work, fluorescent molecularly imprinted nanoparticles were synthesized by precipitation polymerization employing fluorescein isothiocyanate as luminescent material, which could efficiently and rapidly detect ciprofloxacin in water samples. The prepared fluorescent molecularly imprinted nanoparticles had remarkable stability and good selectivity with the method detection limit low to 4.04 nm. In addition, the fluorescent‐imprinted nanoparticles were capable of identifying the target with high detection efficiency and were applied to the detection of ciprofloxacin in aquaculture water with complex composition. All these would provide the direct monitoring of ciprofloxacin in environmental water with a promising fluorescent imprinting strategy.
Carcass age and searcher identity affect morphological assessment of sex of bats
Authors: Nelson David M. , Nagel Juliet , Trott Regina , Campbell Caitlin J. , Pruitt Lori , Good Rhett E. , Iskali Goniela , Gugger Paul F.
Published: August 2018

Carcasses provide an important resource for assessing the vulnerability of bat species and sexes to threats, but the reliability of sex data derived from the external morphology (sexmorph) of bat carcasses remains uncertain. We used genetic‐based assessment of sex (sexgen) to evaluate the effect of carcass age and searcher identity on sexmorph‐based assessments of eastern red (Lasiurus borealis) and hoary (Lasiurus cinereus) bat carcasses identified by 15 different searchers at a wind‐energy facility. The proportion of carcasses for which sexmorph was unknown increased from 0.11 for those recovered within a day of death, to 0.56 within 2–3 days of death, and to ≥0.82 at ≥4 days after death. The proportion of carcasses for which sexmorph was correct decreased from 0.9 for those recovered within a day of death, to 0.65 within 2–3 days of death, and to 0.25 at ≥4 days after death. The proportion of sexmorph misidentifications of the 108 fresh carcasses (collected within 24 hours of death) varied (0.0–0.43) among searchers. These results suggest that sexmorph‐based assessments should be limited to fresh carcasses. Furthermore, additional training of people who collect and identify bat carcasses from renewable‐energy facilities may improve the accuracy of sexmorph data obtained from carcasses. © 2018 The Wildlife Society.
The impact of flexibility on flow, turbulence, and vertical mixing in coastal canopies
Authors: Abdolahpour Maryam , Ghisalberti Marco , McMahon Kathryn , Lavery Paul S.
Published: August 2018

Physical modeling of canopy‐flow interactions has mostly employed rigid model vegetation, whereby the canopy geometry (i.e., its height and frontal area) is invariant and easily quantified. Here, we demonstrate that embedding realism in model vegetation, in the form of buoyancy and flexibility, can profoundly impact the structure of the flow and rates of vertical mixing in wave‐dominated conditions. A laboratory investigation was undertaken with two types of model canopy: (1) rigid canopies consisting of wooden dowels, and (2) flexible, buoyant model plants designed to mimic meadows of the seagrass Posidonia australis. To isolate the impact of flexibility, the maximum heights and frontal areas of the two types of canopy were matched. These canopies were subjected to oscillatory flows with a realistic range of wave heights and periods. Drag reduction caused by the reconfiguration of flexible canopies leads to a greatly diminished velocity attenuation in the canopy (by, on average, 65%). The reduced average height of flexible canopies shifts the canopy shear layer toward the bed, resulting in significantly enhanced levels of near‐bed turbulence. Finally, a decreased vertical diffusivity (by approximately 35%) was observed in the flexible model canopies, relative to the rigid analogues. Thus, while the use of dynamically scaled vegetation adds complexity to modeling efforts, it represents a step toward a more accurate quantitative understanding of flow and mixing in these environments.
A universal bacterial inoculum for dissolved organic carbon biodegradation experiments in freshwaters
Authors: Pastor Ada , Catalán Núria , Nagar Nupur , Light Tricia , Borrego Carles M. , Marcé Rafael
Published: August 2018

Dissolved organic carbon (DOC) is one of the largest biologically available sources of organic C in aquatic ecosystems, and its dynamics have implications for local and global C cycling. Usually, DOC biodegradation is assessed in laboratory incubations using native microbial communities as inoculum. The use of native inocula might hamper the comparability of biodegradation rates across systems and obstructs the identification of other controls on DOC biodegradation. Here, we propose the use of the Standardized Bacterial Inoculum (SBI) in experiments of freshwater DOC degradation that would allow for the assessment of the potential degradability of DOC and identification of the drivers of degradation without interferences from the diverse metabolic capabilities of native communities. The SBI is composed of six bacterial strains that grow easily under laboratory conditions and showed better DOC degradation performance than the single strains separately. The SBI performance was tested on simple C sources, humic acids, and natural organic matter from a range of freshwater ecosystems. The fraction and rates of C‐substrates degradation by the SBI was consistently replicated under oxic and anoxic conditions. Moreover, DOC degradation rates by the SBI were equivalent to those of the native communities. Finally, the SBI consumed up to 31% of natural DOC from a variety of lakes, rivers, and peatlands over a 28‐d period. Overall, the use of the SBI in future DOC degradation experiments will improve comparability among studies and will allow for the separation of effects caused by intrinsic DOC properties from those caused by heterogeneous microbial assemblages.
Liver Transplantation and Bariatric Surgery: Timing and Outcomes
Authors: Diwan Tayyab S. , Rice Teresa C. , Heimbach Julie K. , Schauer Daniel P.
Published: August 2018

Nonalcoholic steatohepatitis (NASH) is projected to become the leading indication for liver transplantation (LT) in the next decade in the United States. Strategies to treat the underlying etiology of NASH, which is almost always obesity, are being pursued. One such strategy is the utilization of bariatric surgery (BS) in the peritransplant period. The use of BS prior to LT could prevent the progression of NASH and abrogate the need for LT. BS at the time of LT or postoperatively has the potential to not only improve obesity‐associated conditions such as diabetes, but also the potential to influence the incidence of NASH in the post‐LT setting. However, there continues to be no consensus on the use and timing of BS in this patient population. This review aims to discuss the current literature and possible future action.
Liver Transplantation Today: Where We Are Now and Where We Are Going
Authors: Bodzin Adam S. , Baker Talia B.
Published: August 2018

Liver transplantation was made a reality through the bravery, innovation, and persistence of Dr. Thomas Starzl. His death in 2017, at the age of 90, makes us pause to consider how far the field has come since its inception by this remarkable pioneer. It also is an opportunity to evaluate the continued novel innovations which contribute to the growth and potential for liver transplantation in the future. The liver transplant community in 2017 continued to be most significantly challenged by an overwhelming disparity between the need for liver transplant and the shortage of donor organs. The many ways in which this critical shortage are being addressed are examined in this article. The continued debate about equitable and efficacious organ allocation, “the liver wars,” has dominated much of the recent past, while efforts to optimize current organ availability have also been aggressively pursued. Efforts to optimize the use of marginal and expanded criteria organs have escalated in recent years and have been accompanied by rigorous scientific evaluation. The ongoing opioid epidemic, combined with the approval and availability of highly effective hepatitis C treatment options, has allowed the increased use of HCV positive organs in HCV positive and negative recipients. Machine perfusion, both cold and warm, has moved solidly into the liver transplant world potentiating optimization of marginal donors and also offering potential modulation of liver grafts (ie, gene therapy, stem cell therapy, and defatting). Finally, pharmacological and mechanical interventions in DCD procurement techniques have contributed to improved outcomes in DCD transplants. All of these are explored in this article as a tribute to innovative spirit of Dr. Starzl and his continued impact on liver transplant today.
Synthesis of Poly(N‐isopropylacrylamide)‐Block‐Poly(tert‐Butyl Methacrylate) Block Copolymer by Visible Light–Induced Metal‐Free Atom Transfer Polymerization
Authors: Xu YangYang , Li Gaocan , Hu Yanfei , Wang Yunbing
Published: August 2018

Atom transfer radical polymerization (ATRP) is one of the most powerful methodologies for polymerization. Well‐controlled ATRP of N‐isopropylacrylamide (NIPAAm) could be obtained in organic‐water mixture solvent with conventional metal catalyst/ligand catalyst system. However, the mixture solvent is not suitable for copolymerization of NIPAAm with hydrophobic monomers. Moreover, further purification of metal was required for biomedical polymerization. Here, poly(N‐isopropylacrylamide) (PNIPAAm) is synthesized by visible light–induced metal‐free ATRP using a photoredox catalyst. PNIPAAm is obtained with high conversion and controlled molecular weight with low dispersity. Moreover, poly(N‐isopropylacrylamide)‐block‐poly(tert‐butyl methacrylate) (PNIPAAm‐b‐PMAA) block copolymer can be synthesized by such metal‐free ATRP. PNIPAAm‐b‐PMAA can be obtained by following hydrolysis.
Ordered Nanostructures of Carbon Nanotube–Polymer Composites from Lyotropic Liquid Crystal Templating
Authors: Kasprzak Christopher R. , Scherzinger Evan T. , Sarkar Amrita , Miao Miranda , Porcincula Dominique H. , Madriz Alejandro M. , Pennewell Zachary M. , Chau Sophia S. , Fernando Raymond , Stefik Morgan , Zhang Shanju
Published: August 2018

A series of polymer nanocomposites containing single‐walled carbon nanotubes (SWNTs) are prepared from polymerizable quaternary ammonium surfactants using photo‐polymerization and investigated by means of polarized optical microscopy, small‐angle X‐ray scattering, and rheological measurements. The surfactant monomers with various alkyl chains of nonpolar tails form lyotropic liquid crystalline (LLC) mesophases in aqueous medium with hexagonal packing of cylindrical micelles. The physical adsorption of nonpolar tails of surfactants on the surface of SWNTs results in de‐bundled nanotubes. The LLC phase diagram is investigated as functions of alkyl chain length, concentration, temperature, and SWNTs. As such, addition of SWNTs does not change the hexagonal mesophases but enhances the order–disorder transition temperatures and alters the rheological behaviors. After photo‐polymerization, the microstructures of hexagonal packing are changed while addition of SWNTs does not disrupt the resulting microstructures. The polymerized composites are consistent with both lamellar and gyroid nanostructures and a possible model is proposed to interpret the observed phenomenon. Under the shear flow, the defect‐free monodomain structures are obtained in the LLC phase and subsequently locked in the solid film after polymerization.
An Efficient Post‐Polymerization Modification of Poly(Styrene‐co‐Maleic Anhydride) for Thermally Reversible Nanocomposites
Authors: Pavía‐Sanders Adriana , Nissen April , O'Bryan Greg
Published: August 2018

A copolymer of maleic anhydride and styrene is functionalized with Diels–Alder (DA) capable pendant groups to enable the study of this material with different crosslink densities. This constituent is synthesized using commercially available starting materials and relatively simple and uncomplicated chemistries which open the possibility for its use in large‐scale applications. The 10%, 25%, 50%, and 100% DA nominal crosslinking based on available pendant furan groups on the polymeric component is investigated. The reaction kinetics are monitored using infrared spectroscopy and rheology. Based on the rheological results, carbon nanotube (CNT) incorporation into the DA matrix is explored in order to determine its effects on the complex modulus of the material. This work is meant as a proof of concept for this DA material with the possibility of its incorporation into other commonly used bulk materials and/or adhesives to allow for an easily reversible product formulation.
Intrinsically Tuning the Electromechanical Properties of Elastomeric Dielectrics: A Chemistry Perspective
Authors: Ellingford Christopher , Bowen Christopher , McNally Tony , Wan Chaoying
Published: August 2018

Dielectric elastomers have the capability to be used as transducers for actuation and energy harvesting applications due to their excellent combination of large strain capability (100–400%), rapid response (10−3 s), high energy density (10–150 kJ m−3), low noise, and lightweight nature. However, the dielectric properties of non‐polar elastomers such as dielectric permittivity εr, breakdown strengthEb, and dielectric loss ε ″, need to be enhanced for real world applications. The introduction of polar groups or structures into dielectric elastomers through covalently bonding is an attractive approach to ‘intrinsically’ induce a permanent polarity to the elastomers, and can eliminate the poor post‐processing issues and breakdown strength of extrinsically modified materials, which have often been prepared by incorporation of fillers. This review discusses the chemical methods for modification of dielectric elastomers, such as hydrosilylation, thiol‐ene click chemistry, azide click chemistry, and atom transfer radical polymerization. The effects of the type and concentration of polar groups on the dielectric and mechanical properties of the elastomers and their performance in actuation and harvesting systems are discussed. State‐of‐the‐art developments and perspectives of modified dielectric elastomers for deformable energy generators and transducers are provided.
Effect of dietary fiber levels on bacterial composition with age in the cecum of meat rabbits
Authors: Wu Zhenyu , Zhou Hailiang , Li Fuchang , Zhang Nanbin , Zhu Yanli
Published: August 2018

This study investigated the influence of dietary fiber levels on the growth performance, digestion, metabolism, and cecal microbial community of rabbits with different diets at different age. The different levels of dietary natural detergent fiber (NDF) were formulated accordingly: 400(A), 350(B), 300(C), 250(D) g/kg original matter basis, respectively; the different ages were 52, 62, and 72 days. With NDF increasing, the average daily feed intake (ADFI) and feed conversion rate (FCR) were increased, whereas average daily gain (ADG) and mortality were decreased (p < 0.05). The stomach relative weight, stomach content relative weight, cecal relative weight, and cecal content weight increased with increasing NDF (p < 0.05). The NH3‐N concentration of cecum dropped when the dietary NDF increased (p < 0.05). The diversity of the total microbiota increased significantly in Diets B, C (p = 0.011), and reached the lowest in 52 days for all diet groups. The richness index was decreased significantly in Diet A, D (p < 0.05) and in 62 days (p < 0.001), respectively. The phylum Firmicutes was higher (p < 0.01) in rabbits fed Diets B, C than Diets A, D and Bacteroidetes was highest in Diets C, D, and Proteobacteria was the highest in Diet A (p < 0.001). Among the classified genera, there were 14 that had levels of abundance of more than 1% and were commonly shared by all samples. Ruminococcus spp. that produced volatile fatty acid (VFA) abundance was highest from Diets B, C at 52 and 62 days. It is interesting to note that Bifidobacterium from Diet C was the most abundant genus during the entire experimental period (p < 0.01). The data from Venn diagrams, principal component analysis (PCA), and heat map plots of the bacterial communities showed that there were more groups of shared microbiota with aging. The above results indicate the cecal microbiota controlled by the 350 g/kg NDF diet can prevent gastrointestinal distress and exhibit good production performance.
RpoN and the Nps and Npa two‐component regulatory system control pilE transcription in commensal Neisseria
Authors: Rendón María A. , Lona Beatriz , Ma Mancheong , So Magdalene
Published: August 2018

Over 20 genes are involved in the biogenesis and function of the Neisseria Type IV pilus (Tfp). In the pathogenic species, RpoD and the integration host factor (IHF) protein regulate expression of pilE, encoding the Tfp structural subunit. We previously reported that in commensal species, pilE transcription is regulated by RpoN, IHF, and activator Npa. Npa has many hallmarks of response regulators in two‐component regulatory systems, leading us to search for its response regulator partner. We report that Npa partners with sensor kinase Nps to control pilE transcription. Among the genes involved in Tfp biogenesis and function, only pilE is controlled by RpoN and Npa/Nps. We summarize our findings in a model, and discuss the implications of the differential regulation of pilE the context of Neisseria Tfp biogenesis.
Disrupting cholesterol esterification by bitter melon suppresses triple‐negative breast cancer cell growth
Authors: Shim So Hee , Sur Subhayan , Steele Robert , Albert Carolyn J. , Huang Chunfa , Ford David A. , Ray Ratna B.
Published: August 2018

Triple negative breast cancer (TNBC) is aggressive with a worse prognosis. We have recently shown that bitter melon extract (BME) treatment was more effective in inhibition of TNBC tumor growth in mouse models as compared to ER positive breast tumor growth. Aberrant dysregulation of lipid metabolism is associated with breast cancer progression, however, anti‐cancer mechanism of BME linking lipid metabolism in breast cancer growth remains unexplored. Here, we observed that accumulation of esterified cholesterol was reduced in BME treated TNBC cell lines as compared to control cells. We next evaluated expression levels of acyl‐CoA: cholesterol acyltransferase 1 (ACAT‐1) in TNBC cells treated with BME. Our results demonstrated that BME treatment inhibited ACAT‐1 expression in TNBC cells. Subsequently, we found that sterol regulatory element‐binding proteins‐1 and ‐2, and FASN was significantly reduced in BME treated TNBC cell lines. Low‐density lipoprotein receptor was also downregulated in BME treated TNBC cells as compared to control cells. We further demonstrated that BME feeding reduced tumor growth in TNBC mammospheres implanted into NSG mice, and inhibits ACAT‐1 expression. To our knowledge, this is the first report demonstrating BME suppresses TNBC cell growth through ACAT‐1 inhibition, and have potential for additional therapeutic regimen against human breast cancer.
FGFR4 provides the conduit to facilitate FGF19 signaling in breast cancer progression
Authors: Zhao Xiangdong , Xu Faliang , Dominguez Nestor P. , Xiong Yuanping , Xiong Zhongxun , Peng Hong , Shay Chloe , Teng Yong
Published: August 2018

Although genetic amplification and overexpression of the fibroblast growth factor 19 (FGF19) gene are found in human breast cancer, mechanisms that contribute to such functional alterations remain elusive. We report here that high expression of FGF19 is associated with the aggressive malignant behavior and poor survival outcome of breast cancer patients. FGF19 is particularly highly expressed in luminal molecular subtype of breast tumors and its expression levels are positively associated with its secretion levels from breast cancer cells. Genetic knockout of FGF19 significantly induces repression of breast tumor progression and metastasis in either an orthotopic mouse model of breast cancer or an experimental metastasis model. The FGF19 specific receptor, FGFR4, can be activated and subsequently upregulate AKT signaling in breast cancer cell upon FGF19, which is critical for oncogenic role of FGF19. Inactivation of FGFR4 by its inhibitor BLU9931 significantly attenuates FGF19‐induced tumor‐promoting activity, suggesting interruption of FGFR4 function is sufficient to affect FGF19‐driven breast cancer. Overall, these insights support the idea that targeting FGFR4 in breast cancer cells overexpressing FGF19 may represent an effective strategy to suppress cancer development, progression, and metastasis.
Late‐onset Levodopa Responsive Parkinsonism Due to Polymerase γ 1 Mutations
Authors: Calejo Margarida , Vilarinho Laura , Neiva Raquel , Botelho Luís , Ramalheira João , Taipa Ricardo , Melo‐Pires Manuel , Lima António Bastos , Damásio Joana
Published: August 2018

View Supplementary Video 1
Generalized function solution of step potentials
Authors: Ünal Basri
Published: August 2018

Schrödinger equation is solved for step function–like potentials within the class of generalized functions. The solution functions carry the same symmetry as the potential. It is shown that the ground state energy is always equal to the minimum value of the potential. Finite square well potential has eigenfunctions both for continuous and discrete spectrum, they form a complete set, and the discrete spectrum does not depend on the well depth. A theorem on the completeness property of transformation operator is proved.
Error analysis for nonconfocal ellipsoidal systems in the forward problem of electroencephalography
Authors: Doschoris Michael , Kariotou Foteini
Published: August 2018

Electroencephalography (EEG) remains the utmost important technique recording brain activity. The present investigation examines the sensitivity of analytic algorithms employed in order to evaluate EEG data with respect to different brain template models. These algorithms are based on mathematical models built upon certain geometrical and/or physical assumptions regarding the head‐brain shape or the neuronal source. While the ellipsoidal head model provides a realistic approach regarding the interpretation of EEG signals in view of diverse geometries, its eccentricities influence strongly the results. The present study quantifies the deviation of the computed electric potentials when nonconfocal ellipsoids are used to model a homogeneous head conductor. To this end, a correspondence is proposed between points of the different ellipsoids, in view of the Gauss map. The investigation demonstrates that the introduction of nonconfocality imports a highly elevated error rate when EEG recordings are misinterpreted by arriving from different head‐brain models, including ellipsoidal vs spherical ones. Moreover, evidence is presented concerning the location of extrema regarding the errors in the upper brain hemisphere, which could lead to a more precise and accurate protocol regarding the placement of sensors. Although the present work refers to the forward EEG problem, its results may be used under other approaches as well. In particular, it provides the error in the solution of an elliptic boundary value problem with transmission conditions under small perturbations of the eccentricities of its ellipsoidal domain.
Generalized wave polynomials and transmutations related to perturbed Bessel equations
Authors: Kravchenko Vladislav V. , Torba Sergii M. , Santana‐Bejarano Jessica Yu.
Published: August 2018

The transmutation (transformation) operator associated with the perturbed Bessel equation is considered. It is shown that its integral kernel can be uniformly approximated by linear combinations of constructed here generalized wave polynomials, solutions of a singular hyperbolic partial differential equation arising in relation with the transmutation kernel. As a corollary of this result an approximation of the regular solution of the perturbed Bessel equation is proposed with corresponding estimates independent of the spectral parameter.
Metastable solutions for the thin‐interface limit of a p‐Laplacian phase field model
Authors: Jiménez‐Casas Ángela
Published: August 2018

We consider a generalization of the semilinear phase field model from G. Caginalp), A. Jiménez‐Casas, and Rodriguez‐Bernal using a nonlinear diffusion operator (p‐Laplacian) for the phase field function. The main objective of this work is to prove the existence of the metastable solutions of the generalized system in the one‐dimensional case, which evolve very slowly in time.
Looking for periodic paralysis: Optimizing the long exercise test
Authors: Shapiro Barbara E. , Preston David C.
Published: August 2018

See article on pages 47–54 in this issue.
Incidence, Types, and Shedding and Ingestion Times of Metallic Fishing Tackle in the Digestive Systems of White Sturgeon
Authors: Lamansky James A. , Meyer Kevin A. , Bowersox Brett J. , DuPont Joe M. , Bentz Brandon , Lepla Ken B.
Published: August 2018

Over the last decade, fishing tackle has been documented in the digestive tracts of White Sturgeon Acipenser transmontanus in several fisheries in the Columbia River basin, raising concerns about the prevalence and types of tackle being consumed and the ability of these long-lived fish to shed such metal in a timely manner. We scanned 2,077 White Sturgeon with a metal detector and X-rayed (with a portable X-ray system) 443 fish in the Hells Canyon reach of the Snake River to characterize the incidence, quantity, and type of hooks and other metal fishing tackle that had been ingested. We also estimated the amount of time for fish to eliminate ingested metal and to ingest new metal. For the fish we captured, which averaged 118 cm and ranged from 47 to 287 cm (fork length), 21% contained metal in their digestive tract, with smaller fish (<100 cm) less likely to contain metal (10%) than larger fish (>100 cm; 36%). Much of the metal in the digestive systems of White Sturgeon was fishing tackle that was not gear targeting White Sturgeon and included large and small hooks, jigs, swivels, and pieces of broken metal. White Sturgeon with metal in their digestive systems, on average, weighed slightly less than fish without metal, suggesting that metal may slightly hinder food consumption or assimilation, though this affect was apparently short lived. White Sturgeon X-rayed at least twice over the course of the study were able to pass ingested metal on average in 492 d, but one piece of metal was retained for at least 1,266 d. White Sturgeon ingested new metal on average every 575 d. In summary, our results suggest that White Sturgeon effectively process the metal they ingest, and that most if not all their metal passage is by oxidation through the digestive system.
Proton Pump Inhibitors: Risks and Rewards and Emerging Consequences to the Gut Microbiome
Authors: Singh Amandeep , Cresci Gail A. , Kirby Donald F.
Published: August 2018

In recent years, proton pump inhibitors (PPIs) have been criticized for their various adverse interactions and side effects, creating a dilemma among practitioners regarding their use. Our goal is to review the proper use and possible side effects that might be caused by or associated with PPI use. Conclusions were drawn based on the evidence supporting or refuting short‐term and long‐term adverse events associated with PPI use. We also looked for the evidence regarding effects of PPIs on gut microbiota and their overall safety profile. Although there are significant discrepancies in the current literature regarding various adverse effects associated with PPI use, current data suggest that PPI use is not associated with an increased risk of bone fractures, community‐acquired pneumonia, cardiovascular events, hypocalcemia, and gastric malignancies. A mild increased risk of vitamin B12 deficiency and chronic kidney disease, and a moderate increase in the risk of rebound hypersecretion, small intestinal bacterial overgrowth, and enteric infections, including Clostridium difficile, has been noted with PPI therapy. PPI's link with dementia and spontaneous bacterial peritonitis is not clear and requires further investigation. When used appropriately, PPIs are safe medications and are associated with minimal side effects. A clear indication and potential short‐term and long‐term side effects should be considered before starting PPI therapy.
On consistency and energy conservation in smoothed particle hydrodynamics
Authors: Islam Md Rushdie Ibne , Chakraborty Sukanta , Shaw Amit
Published: August 2018

Energy conservation and consistency are not easy to achieve simultaneously in smoothed particle hydrodynamics (SPH). In this study, an efficient strategy is proposed to achieve energy conservation in an SPH framework with a consistent basis function. Herein, at every particle pair interaction, a correction term is introduced such that energy conservation is restored locally and, at the same time, the total variation of different variables due to the correction term is minimum. The final form of the proposed formulation is such that no additional computational effort is required and the simplicity of SPH is preserved. The theoretical error estimate of the proposed formulation is performed. The proposed scheme is also compared with benchmark SPH formulations in terms of the L2 error norm for representative functional derivatives both in regular and irregular particle distributions. Finally, the efficacy of the proposed formulation in conserving energy and maintaining accuracy is demonstrated via few elastic, elastic‐plastic impact and fracture problems.
Mechanochemical Synthesis of Iron and Cobalt Magnetic Metal Nanoparticles and Iron/Calcium Oxide and Cobalt/Calcium Oxide Nanocomposites
Authors: Chaudhary Varun , Zhong Yaoying , Parmar Harshida , Sharma Vinay , Tan Xiao , Ramanujan Raju V.
Published: August 2018

We report an environmentally benign and cost‐effective method to produce Fe and Co magnetic metal nanoparticles as well as the Fe/Cao and Co/CaO nanocomposites by using a novel, dry mechanochemical process. Mechanochemical milling of metal oxides with a suitable reducing agent resulted in the production of magnetic metal nanoparticles. The process involved grinding and consequent reduction of low‐costing oxide powders, unlike conventional processing techniques involving metal salts or metal complexes. Calcium granules were used as the reducing agent. Magnetometry measurements were performed over a large range of temperatures, from 10 to 1273 K, to evaluate the Curie temperature, blocking temperature, irreversibility temperature, saturation magnetization, and coercivity. The saturation magnetizations of the iron and cobalt nanoparticles were found to be 191 and 102 emu g−1, respectively. The heating abilities of these nanoparticles suspended in several liquids under alternating magnetic fields were measured and the specific loss power was determined. Our results suggest that the dry mechanochemical process is a robust method to produce metallic nanoparticles and nanocomposites.
Pretreatment Chemicals Pay Dividends Downstream
Authors: Sarchet William V. , Lackey Elizabeth B.
Published: August 2018

A recent study was conducted to identify and pilot alternate coagulants to mitigate membrane fouling at a Colorado ultrafiltration plant.
Electrical response of novel carbon nanotubes embedded and carbon fiber Z‐axis reinforced jute/epoxy laminated composites
Authors: Yang Sen , Chalivendra Vijaya , Benjamin Essien , Kim Yong
Published: August 2018

Novel conductive jute/epoxy laminated composites were fabricated by embedding carbon nanotubes (CNTs) in the matrix and flocking short carbon fibers between the laminates. A three‐dimensional electrical conductive network was generated inside the composites and the electrical resistivity values were measured using a four circumferential probe measurement system. A parametric study was performed to investigate the effect of three different weight percentages of CNTs (0%, 0.025% and 0.1%), two different carbon fiber lengths (150µm and 350µm), four different carbon fiber flock densities (500, 1000, 1500 and 2000 fibers/mm2) and two different laminates' orientations ((0‐0‐0‐0)T and (0‐90‐0‐90)T) on the resistivity values of the composites. Composites with the lowest resistivity value of 0.019 Ohms‐m was achieved for 0.1 wt.% of CNTs and 350µm with flock density of 2000 fibers/mm2 for ((0‐0‐0‐0)T laminate orientation. The increase in flock length from 150µm to 350µm significantly decreased the resistivity by several orders because 350µm generated better conductive network with neighbouring carbon fibers as well as with CNTs. The flock density of carbon fibers has a dominant effect on 150µm long fibers compared to 350µm when the flock density increased from 1000 fibers/mm2 to 1500 fibers/mm2. Variation of both CNTs weight percentage and laminate orientation did not have significant effect on change in resistivity. The electrical measurement investigation of these novel conductive natural fiber composites will have applications in in‐situ damage sensing and structural health monitoring. POLYM. COMPOS., 40:E1189–E1198, 2019. © 2018 Society of Plastics Engineers
h‐BN huddled starch reinforced polyethylhexylacrylate\polyvinyl alcohol thin films for packaging applications
Authors: Prusty Kalyani , Swain Sarat K.
Published: August 2018

Herein, starch hybrid polyethylhexylacrylate\polyvinyl alcohol (PEHA/PVA‐s) thin films are synthesized by in situ polymerization of ethylhexylacrylate (EHA) with incorporation of hexagonal boron nitride (h‐BN). The occurrence of h‐BN nanoparticles in PEHA/PVA‐s thin films is characterized by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), and energy dispersive X‐ray (EDX) analysis. The field emission scanning electron microscopy (FESEM) images illustrates the embedment of h‐BN nanoparticles in the PEHA/PVA‐s films. It is found that, h‐BN nanoparticles have an average particle size of 100 nm observed with a lattice fringe of 0.35 nm are known from high resolution transmission electron microscopy (HRTEM) images. The surface and nano‐tribological features of thin films are studied by atomic force microscope (AFM). The thermal conductivity of films is enhanced with increase in h‐BN concentrations. From rheological study, it is observed that, the tan δ value varies from 0.3 to 0.5. The biodegradation, refractive index, and chemical resistance properties of the thin films are studied. The oxygen barrier properties of the thin films are substantially reduced by 18 folds due to incorporation of huddled h‐BN layers. The prepared PEHA/PVA‐s@h‐BN thin films with improved physicochemical behaviors and reduction in gas barrier properties can enable the material for packaging applications. POLYM. COMPOS., 40:1810–1818, 2019. © 2018 Society of Plastics Engineers
Resistance gradient polymeric electromagnetic shielding composites: Preparation and Characterization
Authors: Wen BianYing , Huan ChunHua , Liu Peng , Zhang Yang
Published: August 2018

Based on the principle of Stokes’ law, a series of polyvinyl butyral (PVB)/nickel (Ni) composite films with a resistance gradient were successfully prepared using a suspension casting method with the aid of gravity. Gradient distribution structure, conductive and mechanical properties, and electromagnetic shielding effectiveness (SE) were investigated. Scanning electron microscopy (SEM) observations and energy‐dispersive spectrometer (EDS) detection show that the gradient distribution of Ni particles in the PVB matrix was formed along the thickness‐direction. A surface resistivity difference of 10 orders of magnitude appears between the top surface (PVB‐rich side) and the bottom surface (Ni‐rich side). Percolation transformation occurs in the range of Ni content of 3.0∼4.5 vol% at the Ni‐rich side, which is much lower than that of PVB/Ni composites with homogeneous Ni distribution. The gradient distribution structure grants the composite both good electromagnetic shielding performance and good mechanical properties. When the Ni loading reaches 10.5 vol% in the film, its SE value rises to 30 dB, which is 15 dB higher than that of a homogenous film with the same filler content. It is believed that electrically conductive gradient polymeric composites have potential application value in the field of electromagnetic shielding. POLYM. COMPOS., 40:1842–1849, 2019. © 2018 Society of Plastics Engineers
Fabrication of Polydopamine‐Modified Carbon Fabric/Polyimide Composites With Enhanced Mechanical and Tribological Properties
Authors: Song Haojie , Li Luying , Yang Jin , Jia Xiaohua
Published: August 2018

To improve poor interfacial adhesion between the surfaces of carbon fabric (CF) and polyimide (PI), in this study, the surfaces of the carbon fibers were coated with bioinspired polydopamine (PDA) to fabricate PDA‐CF/PI composites with enhanced mechanical and tribological properties. The tensile strength and modulus of PDA‐CF/PI composites were obviously superior to those of the CF/PI composites, which indicated that the introduction of PDA brought about considerable improvement in interfacial compatibility of CF with the PI matrix. The effects of PDA‐CF on the improving friction and wear of the PI composites were demonstrated. Tribology tests showed the PDA‐CF/PI composites exhibited the lowest friction coefficient and wear rate compared to that of pure PI and CF/PI composites. The analysis of the worn surfaces after friction confirmed that the outstanding tribological performances of the PDA‐CF/PI composites could be attributed to the improvement of interfacial compatibility between of PDA‐CF with the PI matrix. POLYM. COMPOS., 40:1911–1918, 2019. © 2018 Society of Plastics Engineers
Interfacial Microstructures and Properties of Silicone Resin Composites by Chemically Grafting Different Functional Polyhedral Oligomeric Silsesquioxanes Onto Carbon Fibers
Authors: Li Shuhui , Lou Nan , Liu Jingxiang , Zhang Chunxu , Zhang Xiandong , Wu Guangshun
Published: August 2018

By designing interface microstructures and interactions, bulk properties of carbon fiber (CF) reinforced polymer composites have been improved obviously. Here, maleamic acid‐isobutyl polyhedral oligomeric silsesquioxanes (MAI‐POSS) and octamaleamic acid‐POSS (OMA‐POSS) were separately modified onto fiber surface by the chemical bonding for enhancing interfacial strength of methylphenylsilicone resin (MPSR) composites. The microstructures and properties between CF and matrix resin were investigated. Two different POSS cages distributed onto the fiber surface uniformly, and enhanced surface roughness greatly (91.3 and 92.8 nm). However, OMA‐POSS grafted CF (CF‐g‐OMAPOSS) showed higher polarity and surface free energy than those of MAI‐POSS grafted CF (CF‐g‐MAIPOSS) owing to the introduction of abundant carboxyl groups onto fiber surface by OMA‐POSS grafting. Interfacial strength of modified composites enhanced significantly, especially for CF‐g‐OMAPOSS composites, which revealed the increases of 16.62% in interlaminar shear strength (ILSS) and 25.47% in interfacial shear strength (IFSS) compared to those of MPSR composites reinforced with CF‐g‐OMAPOSS. Interfacial reinforcing mechanisms of composites have also been analyzed and compared. In addition, the introduced strong SiOSi bonds in fiber–matrix interface were the main contributor for the obvious enhancement of hydrothermal aging resistance. POLYM. COMPOS., 40:E714–E722, 2019. © 2018 Society of Plastics Engineers
Directly coating silanized nanocrystalline cellulose on carbon fiber for enhancing the interfacial adhesion of carbon fiber/epoxy resin composites
Authors: Zhang Mengjie , Li Ming , Liu Liu , Fu Junsong , Jin Lin , Shang Lei , Xiao Linghan , Ao Yuhui
Published: August 2018

A continuous coating was used to treat carbon fibers (CFs) with silanized nanocrystalline cellulose (NCC) for enhancing the interfacial adhesion of CF/epoxy composites. The NCC was silanized with 3‐aminopropyltriethoxysilane and then was applied to modify the CF surface for increasing the surface roughness of the CF and achieving chemical bonding between the CF and epoxy resin. The morphologies of the modified CFs with different contents of silanized NCC were characterized by a scanning electron microscope (SEM) and the performance of the silanized NCC‐coated CF/epoxy composites was characterized by an interfacial shear strength (IFSS) test and a flexural test. The experimental results indicated that excessively silanized NCC had reduced interfacial properties due to the agglomeration of NCC. Notably, increases of 94.22% in IFSS and 23.24% in flexural strength were achieved in 0.3 wt% silanized NCC‐coated CF/epoxy composites compared to the desized CF/epoxy composites. As a result, dispersion of silanized NCC in the interface regions was one of the critical factors influencing the interfacial properties of the composites. Coating CFs with silanized NCC provided valuable method based on an abundant raw material for strengthening the interfacial adhesion between CF and epoxy resin matrix. POLYM. COMPOS., 40:E744–E752, 2019. © 2018 Society of Plastics Engineers
Colorimetric Co2+ sensor based on an anionic pyridylazo dye and a cationic polyelectrolyte in aqueous solution
Authors: Inoue Koshiro , Aikawa Shunichi , Sakamaki Masaru , Fukushima Yasumasa
Published: August 2018

A new naked‐eye colorimetric sensor for detecting Co2+ in a pure aqueous solution at pH 7.0 was developed by mixing an anionic organic dye, 2‐(5‐bromo‐2‐pyridylazo)‐5‐(N‐propyl‐N‐sulfopropylamino)phenol (5‐Br‐PAPS) with a cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (PDADMAC). Upon addition of Co2+, the absorption maximum exhibited a remarkable bathochromic shift from 426 to 635 nm (Δ = 209 nm) with a detectable color change from yellow, green to blue, while other metal ions did not induce such a change. The results showed that the 5‐Br‐PAPS and PDADMAC mixture can be used as a selective and sensitive naked‐eye colorimetric chemosensor for Co2+. This study afforded a simple strategy to construct a novel chemosensor by a simple mixture of an organic dye and an oppositely charged polyelectrolyte. © 2018 Society of Chemical Industry
Some novel nanostructure Schiff base compounds: Antimicrobial and thermal behaviors
Authors: Khani S. , Montazerozohori M. , Naghiha R.
Published: August 2018

In this paper, five new zinc‐Schiff base compounds formulated as ZnLX2 (L is a new N3‐Schiff base ligand obtained by condensation reaction between diethylenetriamine and (Z)‐3‐(4‐(dimethylamino)phenyl) acrylaldehyde and X is (Cl−, Br−, I−, N3−, and NCS−)) were synthesized and characterized by Fourier transform infrared, 1H and 13C NMR, UV–visible, thermal analyses, and molar conductivity measurements. Low molar conductivity values of the compounds in dimethylformamide (DMF) showed nonelectrolyte character of them. Zinc complexes have been also prepared in nanostructure sizes under ultrasonic irradiation confirmed by X‐ray powder diffraction and scanning electron microscopy. Thereafter, ZnO nanoparticles were prepared by direct calcination process of zinc iodide complex at 600°C under air atmosphere. Furthermore, thermogravimetric analyses of the complexes were used for the investigation of thermal behavior of the tiled compounds. Based on TG/DTG plots, some kinetics activation parameters of the compounds at all thermal decomposition steps were calculated. In final, antimicrobial activities of the compounds were investigated by the well diffusion technique against the gram‐positive bacteria of Staphylococcus aureus and Bacillus subtilis, and the gram‐negative bacteria of Escherichia coli and Pseudomonas aeruginosa and the fungi strains of Aspergillus oryzae and Candida albicans. The results showed that all zinc‐Schiff base organic compounds are more antimicrobial active than free ligand.