bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Standardized Method for Quantification of Humic and Fulvic Acids in Humic Ores and Commercial Products
Authors: Lamar Richard T , Olk Daniel C , Mayhew Lawrence , Bloom Paul R
Published: June 2014

Increased use of humic substances in agriculture has generated intense interest among producers, consumers, and regulators for an accurate and reliable method to quantify humic acid (HA) and fulvic acid (FA) in raw ores and products. Here we present a thoroughly validated method, the new standardized method for determination of HA and FA contents in raw humate ores and in solid and liquid products produced from them. The methods used for preparation of HA and FA were adapted according to the guidelines of the International Humic Substances Society involving alkaline extraction followed by acidification to separate HA from the fulvic fraction. This is followed by separation of FA from the fulvic fraction by adsorption on a nonionic macroporous acrylic ester resin at acid pH. It differs from previous methods in that it determines HA and FA concentrations gravimetrically on an ash-free basis. Critical steps in the method, e.g., initial test portion mass, test portion to extract volume ratio, extraction time, and acidification of alkaline extract, were optimized for maximum and consistent recovery of HA and FA. The method detection limits for HA and FA were 4.62 and 4.8 mg/L, respectively. The method quantitation limits for HA and FA were 14.7 and 15.3 mg/L, respectively.
Modification to AOAC Official Methods 2009.01 and 2011.25 to Allow for Minor Overestimation of Low Molecular Weight Soluble Dietary Fiber in Samples Containing Starch
Authors: McCleary Barry V
Published: June 2014

AOAC Official Methods 2009.01 and 2011.25 have been modified to allow removal of resistant maltodextrins produced on hydrolysis of various starches by the combination of pancreatic α-amylase and amyloglucosidase (AMG) used in these assay procedures. The major resistant maltodextrin, 63,65-di-α-D-glucosyl maltopentaose, is highly resistant to hydrolysis by microbial α-glucosidases, isoamylase, pullulanase, pancreatic, bacterial and fungal α-amylase and AMG. However, this oligosaccharide is hydrolyzed by the mucosal α-glucosidase complex of the pig small intestine (which is similar to the human small intestine), and thus must be removed in the analytical procedure. Hydrolysis of these oligosaccharides has been by incubation with a high concentration of a purified AMG at 60°C. This incubation results in no hydrolysis or loss of other resistant oligosaccharides such as FOS, GOS, XOS, resistant maltodextrins (e.g., Fibersol 2) or polydextrose. The effect of this additional incubation with AMG on the measured level of low molecular weight soluble dietary fiber (SDFS) and of total dietary fiber in a broad range of samples is reported. Results from this study demonstrate that the proposed modification can be used with confidence in the measurement of dietary fiber.
The Effects of Interphase and Interface Characteristics on the Tensile Behaviour of POM/CaCO3 Nanocomposites
Authors: Zakaria Afshin Zamani , Shelesh-Nezhad Karim
Published: June 2014

The condition of the interfacial area and interphase region in a nanocomposite can significantly affect its mechanical performance. In this research, the tensile performance of a POM/CaCO3 nanocomposite, including the modulus of elasticity and tensile strength, are analysed using different mathematical models and the Ansys FEM software. The mechanisms of the plastic deformation and crazing of the POM/CaCO3 nanocomposite were investigated using FEM. Furthermore, the effects of interface adhesion and the interphase property on interfacial debonding, as well as tensile properties, were analysed. The tensile strength of the nanocomposite could not be greater than that of bulk POM because of the failure which was initiated from the matrix. By stiffening the interphase and increasing the adhesion between nanoparticle and polymer, the nanocomposite's elastic modulus and strength were increased. Two toughening mechanisms, including plastic deformation and crack initiation, were observed in the POM/CaCO3 nanocomposite. The high interfacial adhesion of the matrix to the particles led to the formation and propagation of crazes along the extension load in the POM matrix. The tensile strengths of different nanocomposites were over-predicted by the Pukanszky model, while the moduli magnitudes estimated by the Ji mathematical model were less when compared to those determined by FEM.
Common Stochastic Volatility in International Real Estate Market
Authors: Wang Yongsheng , Fadiga Mohamadou L.
Published: June 2014

This study examined the real estate markets of Europe, North America, and Asia using daily continental real estate indices. It applied a multivariate stochastic volatility model to analyze the behavior of volatility trends in these markets. The results showed comovements in volatilities, especially between Europe and North America, as indicated by high degrees of correlation of their respective stochastic trend components. However, the impact of this common trend varies in these markets, especially for the early period of the sample. For the later period of the sample, the derived volatility trend indicated volatility convergence among them. It might imply that the role of emerging market such as Asia in diversifying real estate investment risk was not as significant as showed in early studies and is diminishing overtime.
Comprehensive Multi-Disciplinary Assessment Protocol for Autism Spectrum Disorder
Authors: Dodd Janet L. , Franke Lauren K. , Grzesik Jeanette K. , Stoskopf Jenna
Published: June 2014

Legal mandates established under IDEA specify a student must be assessed in all areas of suspected disability. Never is this task more overwhelming than its application to the assessment of a student suspected of a diagnosis of autism. The assessment of an individual suspected of an autism spectrum disorder (ASD) diagnosis is a complex task and is dependent on the integration of information gleaned from assessments conducted by an array of professionals, each with their own distinct area of expertise. The purpose of this article is to introduce the Comprehensive Multidisciplinary Assessment Protocols-Autism Spectrum Disorder, referred to as the CMAPs, as a mechanism for organizing multidisciplinary team assessments. The CMAPs were developed in response to the challenges experienced by school-based assessment teams in developing appropriate and legally defensible assessment plans. The CMAPs provide teams a systematic, organizational, and comprehensive platform to organize the assessment of students across the spectrum of the disorder with the goal of making the task less overwhelming.  Each assessment protocol considers the assessment needs of individuals with ASD using their communication skills as a preliminary starting point.
Expanding the Role of Pharmacists and Pharmacy Students in the Promotion of Organ Donation Awareness
Authors: Descourouez Jillian L. , Richards Katelyn R. , Sam Teena , Crowther Barrett
Published: June 2014

The gap between supply and demand for available organs has resulted in numerous deaths of patients on the transplant waiting list each year. Given the substantial public health impact of the organ shortage crisis, efforts have been focused on the use of educational interventions aimed both at the public and health care professionals to spread awareness of the disparity in organ supply and demand and ultimately improve organ donation rates. Transplant pharmacists are fundamental members of transplant multidisciplinary teams and are expected to promote organ and tissue awareness in an effort to decrease the morbidity and mortality of patients on the transplant waiting list. The role of pharmacists and pharmacy students in the promotion of organ donation awareness is expanding.
Pursuing Expanded Criteria Donors as Candidates for Kidney Donation after Circulatory Death
Authors: DeLario Ginger T. , Quetschenbach Jim , Croezen Donna , Niedfeldt Danielle , Landon Julie
Published: June 2014

Of the 119 310 people on the national transplant waiting list, 97 280 people are waiting for kidneys. There simply are not enough organs to meet the demand. Recognizing that 64% of the people waiting for kidney transplants are at least 50 years old, this organ procurement organization embarked on a study to evaluate the potential of increasing the number of viable kidneys available for transplant by pursuing expanded criteria donors as donation after circulatory death (ECD/DCD) candidates. Pursuing ECD/DCD donors resulted in 24 additional donors (50–67 years old), 48 kidneys recovered, 30 kidneys transplanted into 26 recipients (44–74 years old), 7 kidneys placed for research, and 11 kidneys discarded, yielding an overall 62% transplant rate, 15% research rate, and 23% discard rate. The overall discard rate including all donors in all classifications during the study period was 13.1% (122 discards from 928 kidneys) compared with 12.6% (111 discards from 880 kidneys) when the study set was excluded. Although ECD/DCD donors still had the highest discard rates of all the groups, the 0.5% increase in the overall discard rate due to pursuing ECD/DCD kidneys was considered insignificant when compared with the benefit of the 30 additional kidneys transplanted. Including potential ECD/DCD patients in the donor pool increases the number of viable kidneys available for transplant without significantly increasing the overall kidney discard rates.
Effect of Mannitol on Postreperfusion Cardiac Output and Central Venous Oxygen Saturation during Orthotopic Liver Transplant: A Double-Blind Randomized Clinical Trial
Authors: Sahmeddini Mohammad Ali , Zahiri Siamak , Khosravi Mohammad Bagher , Ghaffaripour Sina , Eghbal Mohammad Hossein , Shokrizadeh Sakine
Published: June 2014

Context

Attenuating postreperfusion syndrome during orthotopic liver transplant is very important for transplant anesthesiologists because of the syndrome's complications. Oxygen-derived free radicals play an important role in the genesis of postreperfusion syndrome, but the effect of mannitol (a free radical scavenger) on attenuating the syndrome is unclear.

Objectives

To investigate the effectiveness of infusing mannitol during the anhepatic phase in preventing postreperfusion syndrome, as indicated by postreperfusion cardiac output and central venous oxygen saturation.

Design

In a randomized clinical trial, 53 patients who had undergone orthotopic liver transplant were allocated to 2 groups. During the anhepatic phase, patients in the mannitol group received 1g/kg mannitol, whereas those in the control group received physiological saline. Mean arterial pressure, cardiac output, and central venous oxygen saturation were measured before and after the portal vein was declamped. Serum levels of sodium and potassium were recorded at baseline and after portal vein declamping.

Setting

Shiraz Organ Transplant Center, Shiraz, Iran.

Results

In the mannitol group, no significant change was found in mean arterial pressure, cardiac output, and central venous oxygen saturation before and after declamping of the portal vein ( P= .78, P= .59, and P= .83, respectively). However, after declamping in the control group, mean arterial pressure, cardiac output, and central venous oxygen saturation were significantly lower than before declamping ( P= .003, P= .001, and P <.001, respectively). No significant change in serum levels of sodium and potassium from baseline to after declamping were found in either group.

Conclusion

Infusion of mannitol 1 g/kg during the anhepatic phase was effective in attenuating postreperfusion syndrome without stress about hyperkalemia or hyponatremia during anesthesia.
Impact of Organ Donation Education on US Undergraduate Nursing Students
Authors: Kurz Jane McCausland
Published: June 2014

Experts advocate educational programs addressing misinformation regarding donation decisions to increase the potential donor pool. However, few researchers have measured outcomes with nursing students. The purpose of this study was to evaluate the impact of an educational intervention on nursing students' knowledge, attitudes, registering as an organ donor, and family discussions. This quasi-experimental study used a pretest-posttest design with a control group. The research group consisted of 42 volunteers and the control group consisted of 73 volunteers. The written survey included 15 true-false knowledge items and 8 Likert items asking about attitude toward donation, registering as an organ donor, and family discussion. Normally distributed data showed no significant differences between groups on the pretest. The research group had no change in knowledge level 3 months later, but the control group had a significantly decreased knowledge level at that point. More members of the research group than the control group registered as organ donors after the intervention (χ2 = 4.5, P = .03). The control group had no change in registering as an organ donor between the pretest and posttest. Family discussions did not differ significantly from pretest to posttest in either group. One lecture/laboratory experience did make a difference in registering as an organ donor but not in discussing the decision with family members. Students can learn about organ donation from more than one specific class. Recommendations for educators and future research are provided.
Independent Donor Ethical Assessment: Aiming to Standardize Donor Advocacy
Authors: Choudhury Devasmita , Jotterand Fabrice , Casenave Gerald , Smith-Morris Carolyn ,   for the University of Texas Southwestern Medical Center Donor Advocacy Team
Published: June 2014

Living organ donation has become more common across the world. To ensure an informed consent process, given the complex issues involved with organ donation, independent donor advocacy is required. The choice of how donor advocacy is administered is left up to each transplant center. This article presents the experience and process of donor advocacy at University of Texas Southwestern Medical Center administered by a multidisciplinary team consisting of physicians, surgeons, psychologists, medical ethicists and anthropologists, lawyers, a chaplain, a living kidney donor, and a kidney transplant recipient. To ensure that advocacy remains fair and consistent for all donors being considered, the donor advocacy team at University of Texas Southwestern Medical Center developed the Independent Donor Ethical Assessment, a tool that may be useful to others in rendering donor advocacy. In addition, the tool may be modified as circumstances arise to improve donor advocacy and maintain uniformity in decision making.
Information Sources, Donation Knowledge, and Attitudes toward Transplant Recipients in Australia
Authors: Hyde Melissa K. , Chambers Suzanne K.
Published: June 2014

Context

Knowledge is linked consistently with organ donation attitudes, willingness, and consent. Negative information about donation and the recipients of donation can affect public opinion and donation willingness. However, it is unclear which information sources are most important in forming knowledge, particularly in Australia where little prior research exists.

Objectives

To identify information sources that may inform Australians' organ donation knowledge and attitudes toward transplant recipients.

Participants

1487 Australian residents aged 18 years or older who completed an online survey.

Main Outcome Measures

Self-reported knowledge, information sources, and attitudes toward transplant recipients.

Results

Participants felt fairly well informed about organ donation, particularly if they registered donation wishes, were female, and were older. More than half reported their driver's license, television news, and discussion with family/friends as donation information sources. However, information sources contributing to knowledge were personal experience, online, hospital, government campaign, discussion with family/friends, Medicare, doctor's surgery, and the newspaper. Differences based on registration status, sex, and age, were found. Discussion with family/friends and movies or television shows, as well as not having seen information in a newspaper or doctor's surgery, contributed to positive attitudes toward recipients, although the variance explained was small.

Conclusions

People felt more informed by personal, medical, and government information sources than by mass media. Family discussion was not only a common information source but also contributed significantly and positively to both donation knowledge and attitudes toward recipients. Further exploration of information sources contributing to donation knowledge and community attitudes toward transplant recipients among young men is needed.
Diagnostic accuracy of the WHO clinical staging system for defining eligibility for ART in sub‐Saharan Africa: a systematic review and meta‐analysis
Authors: Munthali Chigomezgo , Taegtmeyer Miriam , Garner Paul G , Lalloo David G , Squire S Bertel , Corbett Elizabeth L , Ford Nathan , MacPherson Peter
Published: June 2014

Introduction

The World Health Organization (WHO) recommends that HIV‐positive adults with CD4 count ≤500 cells/mm3 initiate antiretroviral therapy (ART). In many countries of sub‐Saharan Africa, CD4 count is not widely available or consistently used and instead the WHO clinical staging system is used to determine ART eligibility. However, concerns have been raised regarding its discriminatory ability to identify patients eligible to start ART. We therefore reviewed the accuracy of WHO stage 3 or 4 assessment in identifying ART eligibility according to CD4 count thresholds for ART initiation.

Methods

We systematically searched PubMed and Global Health databases and conference abstracts using a comprehensive strategy for studies that compared the results of WHO clinical staging with CD4 count thresholds. Studies performed in sub‐Saharan Africa and published in English between 1998 and 2013 were eligible for inclusion according to our predefined study protocol. Two authors independently extracted data and assessed methodological quality and risk of bias using the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS‐2) tool. Summary estimates of sensitivity and specificity were derived for each CD4 count threshold and hierarchical summary receiver operator characteristic curves were plotted.

Results

Fifteen studies met the inclusion criteria, including 25,032 participants from 14 countries. Most studies assessed individuals attending ART clinics prior to treatment initiation. WHO clinical stage 3 or 4 disease had a sensitivity of 60% (95% CI: 45–73%, Q=914.26, p<0.001) and specificity of 73% (95% CI: 60–83%, Q=1439.43, p<0.001) for a CD4 threshold of ≤200 cells/mm3 (11 studies); sensitivity and specificity for a threshold of CD4 count ≤350 cells/mm3 were 45% (95% CI: 26–66%, Q=1607.31, p<0.001) and 85% (95% CI: 69–93%, Q=896.70, p<0.001), respectively (six studies). For the threshold of CD4 count ≤500 cells/mm3 sensitivity was 14% (95% CI: 13–15%) and specificity was 95% (95% CI: 94–96%) (one study).

Conclusions

When used for individual treatment decisions, WHO clinical staging misses a high proportion of individuals who are ART eligible by CD4 count, with sensitivity falling as CD4 count criteria rises. Access to accurate, accessible, robust and affordable CD4 count testing methods will be a pressing need for as long as ART initiation decisions are based on criteria other than seropositivity.
Impact of changes in barometric pressure on landfill methane emission
Authors: Xu Liukang , Lin Xiaomao , Amen Jim , Welding Karla , McDermitt Dayle
Published: June 2014

Landfill methane emissions were measured continuously using the eddy covariance method from June to December 2010. The study site was located at the Bluff Road Landfill in Lincoln, Nebraska, USA. Our results show that landfill methane emissions strongly depended on changes in barometric pressure; rising barometric pressure suppressed the emission, while falling barometric pressure enhanced the emission, a phenomenon called barometric pumping. There was up to a 35‐fold variation in day‐to‐day methane emissions due to changes in barometric pressure. Wavelet coherence analysis revealed a strong spectral coherency between variations of barometric pressure and methane emission at periodicities ranging from 1 day to 8 days. Power spectrum and ogive analysis showed that at least 10 days of continuous measurements was needed in order to capture 90% of the total variance in the methane emission time series at our landfill site. From our results, it is clear that point‐in‐time measurements taken at monthly or longer time intervals using techniques such as the trace plume method, the mass balance method, or the closed‐chamber method will be subject to large variations in measured emission rates because of the barometric pumping phenomenon. Estimates of long‐term integrated methane emissions from landfills based on such measurements could yield uncertainties, ranging from 28.8% underestimation to 32.3% overestimation. Our results demonstrate a need for continuous measurements to quantify annual total landfill emissions. This conclusion may apply to the study of methane emissions from wetlands, peatlands, lakes, and other environmental contexts where emissions are from porous media or ebullition. Other implications from the present study for hazard gas monitoring programs are also discussed.
Compaction around a rigid, circular inclusion in partially molten rock
Authors: Alisic Laura , Rudge John F. , Katz Richard F. , Wells Garth N. , Rhebergen Sander
Published: June 2014

Conservation laws that describe the behavior of partially molten mantle rock have been established for several decades, but the associated rheology remains poorly understood. Constraints on the rheology may be obtained from recently published experiments involving deformation of partially molten rock around a rigid, spherical inclusion. These experiments give rise to patterns of melt segregation that exhibit the competing effects of pressure shadows and melt‐rich bands. Such patterns provide an opportunity to infer rheological parameters through comparison with models based on the conservation laws and constitutive relations that hypothetically govern the system. To this end, we have developed software tools to simulate finite strain, two‐phase flow around a circular inclusion in a configuration that mirrors the experiments. Simulations indicate that the evolution of porosity is predominantly controlled by the porosity‐weakening exponent of the shear viscosity and the poorly known bulk viscosity. In two‐dimensional simulations presented here, we find that the balance of pressure shadows and melt‐rich bands observed in experiments only occurs for bulk‐to‐shear viscosity ratio of less than about five. However, the evolution of porosity in simulations with such low bulk viscosity exceeds physical bounds at unrealistically small strain due to the unchecked, exponential growth of the porosity variations. Processes that limit or balance porosity localization should be incorporated in the formulation of the model to produce results that are consistent with the porosity evolution in experiments.
Ferro and antiferromagnetism of ultrafine‐grained hematite
Authors: Jiang Zhaoxia , Liu Qingsong , Dekkers Mark J. , Colombo Claudio , Yu Yongjae , Barrón Vidal , Torrent José
Published: June 2014

Aluminum‐substituted hematite (here referred to as Al‐Hm) is an important magnetic mineral for paleo and environmental magnetism. However, the magnetic properties of nanosized Al‐Hm are poorly known. In this study, a series of Al‐Hm samples (fourteen samples) and their nonsubstituted counterparts (referred to as pure‐Hm) (seven samples) were synthesized with particle sizes ranging from 14 to 124 nm. With decreasing particle size, coercive force (Bc), magnetic remanence (Mr) acquired in a 5 T field at room temperature, and the maximum blocking temperature (Tb) of Al‐Hm descend gradually; Tb drops abruptly from 800 to 200 K at 17.2 ± 3.7 nm. This size defines the superparamagnetic (SP)/single‐domain (SD) threshold of Al‐Hm which is significantly lower than that of pure‐Hm (27.5 ± 1.5 nm). The antiferromagnetic high‐field susceptibility (χanti) and the saturation magnetization (Ms) for the weak ferromagnetic component in hematite are both correlated negatively with temperature between 20 and 300 K, and grain size in the vicinity of the SP threshold. For very small grains (below 16–17 nm), Tb increases with increasing particle size. However, beyond this size, it descends with increasing particle size up to 19 nm before increasing with grain size again. These trends are attributed to the competition of surface anisotropy and bulk anisotropy (elastic anisotropy). This new study substantially improves our understanding of the complex magnetic properties of fine‐grained Al‐Hm and pure‐Hm in natural sample, which is significant for the paleoenvironmental and climatic studies of natural samples, e.g., red beds/soils.
Influence of microscale heterogeneity and microstructure on the tensile behavior of crystalline rocks
Authors: Mahabadi O. K. , Tatone B. S. A. , Grasselli G.
Published: June 2014

This study investigates the influence of microscale heterogeneity and microcracks on the failure behavior and mechanical response of a crystalline rock. The thin section analysis for obtaining the microcrack density is presented. Using micro X‐ray computed tomography (μCT) scanning of failed laboratory specimens, the influence of heterogeneity and, in particular, biotite grains on the brittle fracture of the specimens is discussed and various failure patterns are characterized. Three groups of numerical simulations are presented, which demonstrate the role of microcracks and the influence of μCT‐based and stochastically generated phase distributions. The mechanical response, stress distribution, and fracturing process obtained by the numerical simulations are also discussed. The simulation results illustrate that heterogeneity and microcracks should be considered to accurately predict the tensile strength and failure behavior of the sample.
Synthesis of 3‐D Coronal‐Solar Wind Energetic Particle Acceleration Modules
Authors: Schwadron Nathan A. , Gorby Matt , Török Tibor , Downs Cooper , Linker Jon , Lionello Roberto , Mikić Zoran , Riley Pete , Giacalone Joe , Chandran Ben , Germaschewski Kai , Isenberg Phil A. , Lee Martin A. , Lugaz Noe , Smith Sonya , Spence Harlan E. , Desai Mihir , Kasper Justin , Kozarev Kamen , Korreck Kelly , Stevens Mike , Cooper John , MacNeice Peter
Published: June 2014

Key Points

Radiation from low corona

Prompt SEP events from CME

Large doses in 2 h
Liquid‐phase hydrogenation of cinnamaldehyde over Cu‐Au/SiO2 catalysts
Authors: Yuan Xiang , Zheng Jianwei , Zhang Qian , Li Shuirong , Yang Yanhui , Gong Jinlong
Published: June 2014

The synthesis, characterization, and application of silica‐supported Cu‐Au bimetallic catalysts in selective hydrogenation of cinnamaldehyde are described. The results showed that Cu‐Au/SiO2 bimetallic catalysts were superior to monometallic Cu/SiO2 and Au/SiO2 catalysts under identical conditions. Adding a small amount of gold (6Cu‐1.4Au/SiO2 catalyst) afforded eightfold higher catalytic reaction rate compared to Cu/SiO2 along with the high selectivity (53%, at 55% of conversion) toward cinnamyl alcohol. Characterization techniques such as x‐ray diffraction, H2 temperature‐programmed reduction, ultraviolet‐visible spectroscopy, transmission electron microscopy, Fourier‐transform infrared spectra of chemisorbed CO, and x‐ray photoelectron spectroscopy were employed to understand the origin of the catalytic activity. A key genesis of the high activity of the Cu‐Au/SiO2 catalyst was ascribed to the synergistic effect of Cu and Au species: the Au sites were responsible for the dissociative activation of H2 molecules, and Cu0 and Cu+ sites contributed to the adsorption‐activation of CC and CO bond, respectively. A combined tuning of particle dispersion and its surface electronic structure was shown as a consequence of the formation of Au‐Cu alloy nanoparticles, which led to the significantly enhanced synergy. A plausible reaction pathway was proposed based on our results and the literature. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3300–3311, 2014
MOF‐derived porous carbon for adsorptive desulfurization
Authors: Shi Yawei , Zhang Xiangwen , Wang Li , Liu Guozhu
Published: June 2014

Significance

ZIF‐8, a typical and popular type of MOFs, was synthesized and carbonized directly to produce highly porous carbon without washing or activation. The resulting carbon was found to be a promising candidate for adsorption desulfurization of DBT with a maximum adsorption capacity of 26.7 mgS/g in the concentration range below 174 ppmS, and the adsorption capacity decreased approximately 17% with the addition of 10% para‐xylene. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2747–2751, 2014
Optimization models for shale gas water management
Authors: Yang Linlin , Grossmann Ignacio E. , Manno Jeremy
Published: June 2014

There are four key aspects for water use in hydraulic fracturing, including source water acquisition, wastewater production, reuse and recycle, and subsequent transportation, storage, and disposal. Water use life cycle is optimized for wellpads through a discrete‐time two‐stage stochastic mixed‐integer linear programming model under uncertain availability of water. The objective is to minimize expected transportation, treatment, storage, and disposal cost while accounting for the revenue from gas production. Assuming freshwater sources, river withdrawal data, location of wellpads, and treatment facilities are given, the goal is to determine an optimal fracturing schedule in coordination with water transportation, and its treatment and reuse. The proposed models consider a long‐time horizon and multiple scenarios from historical data. Two examples representative of the Marcellus Shale play are presented to illustrate the effectiveness of the formulation, and to identify optimization opportunities that can improve both the environmental impact and economical use of water. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3490–3501, 2014
Photochemical removal of NO and SO2 from flue gas using UV irradiation
Authors: Liu Hao , Wu Hao , Bao Jingjing , Yu Xianqun , Yang Hongmin
Published: June 2014

The simultaneous oxidation and removal efficiencies of SO2 and NO from simulated coal‐fired flue gas by UV irradiation were investigated experimentally. The influencing factors, such as the reaction temperature, the content of O2, H2O, SO2, and NO, on the removal of SO2 and NO were studied. The results indicated that NO had positive effect on the removal of SO2. Compared with the NO‐free case, the removal efficiency of SO2 was improved from 8% to 55% in the presence of 250 ppm NO. When the NO concentration rose from 250 to 700 ppm, the SO2 removal efficiency further increased from 55% to 64%. The increasing of reaction temperature enhanced the removal efficiencies of SO2 and NO, which increased by 28% and 36%, respectively, with the reaction temperature rising from 270 to 350 °C. It was found that O2 was conducive to the photochemical oxidization due to the generation of free radicals. As the O2 content increased from 0% to 8%, the removal efficiencies of NO and SO2 reached 40% and 55%, respectively. The positive effect of H2O on the simultaneous removal of NO and SO2 was also observed. The optimal conditions (250 ppm NO, 100 ppm SO2, 8% O2, 5% H2O, and reaction temperature 350 °C) were determined, and the removal efficiencies of SO2 and NO were 55% and 40%, respectively. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Effects of micro and nano β‐TCP fillers in freeze‐gelled chitosan scaffolds for bone tissue engineering
Authors: Siddiqui Nadeem , Pramanik Krishna
Published: June 2014

Tissue engineering holds an exciting promise in providing a long‐term cure to bone‐related defects and diseases. However, one of the most important prerequisites for bone tissue engineering is an ideal platform that can aid tissue genesis by having biomimetic, mechanostable, and cytocompatible characteristics. Chitosan (CS) was chosen as the base polymer to incorporate filler, namely beta‐tri calcium phosphate (β‐TCP). This research deals with a comparative study on the properties of CS scaffolds prepared using micro‐ and nano‐sized β‐TCP as filler by freeze gelation method. The scaffolds were characterized for their morphology, porosity, swelling, structural, chemical, biodegradation, and bioresorption properties. Rheological behavior of polymer and polymer‐ceramic composite suspensions were analyzed and all the suspensions with varying ratios of β‐TCP showed non‐Newtonian behavior with shear thinning property. Pore size, porosity of micro‐ and nano‐sized composite scaffolds are measured as 48–158 μm and 77% and 43–155 μm and 81%, respectively. The scaffolds containing nano β‐TCP possess higher compressive strength (∼2.67 MPa) and slower degradation rate as compared to composites prepared with micro‐sized β‐TCP (∼1.52 MPa). Bioresorbability, in vitro cell viability by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay, proliferation by Alamar blue assay, cell interaction by scanning electron microscope, and florescence microscopy further validates the potentiality of freeze‐gelled CS/β‐TCP composite scaffolds for bone tissue engineering applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41025.
Preparation of poly(methyl methacrylate)‐grafted attapulgite by surface‐Initiated radical polymerization
Authors: Yang Haicun , Pu Hongting , Gong Fanghong
Published: June 2014

Poly(methyl methacrylate) (PMMA) was bonded on the surface of attapulgite (ATP) by using an ammonium persulfate amine redox initiation system via grafting from approach. ATP was modified with (3‐aminopropyl)triethoxysilane to anchor amine groups on the surface, and then the amine‐functionalized ATP was further treated with methacryloyl chloride and 4,4′‐azobis(4‐cyanovaleric acid) to give methacryl‐ and azo‐functionalized ATP, respectively. Subsequently, surface‐initiated graft polymerization of MMA in a soap‐free emulsion was performed to afford ATP/PMMA hybrids. Meanwhile, graft polymerizations on the surface of methacryl‐ and azo‐functionalized ATP were carried out for comparison. The grafting of PMMA on the surface of ATP was characterized by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and thermogravimetric analysis (TGA). The crystal structure of hybrids was characterized by X‐ray diffraction analysis. The morphology of hybrids was observed by scanning electron microscopy and transmission electron microscopy. The degree of grafting obtained from surface‐initiated graft polymerization in a soap‐free emulsion was found to be the greatest (29.4%) estimated from TGA. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41062.
A novel UV‐curable epoxy acrylate resin containing arylene ether sulfone linkages: Preparation, characterization, and properties
Authors: Cui Jidi , Yu Guipeng , Pan Chunyue
Published: June 2014

UV‐curing processes are used in industrial applications because of their advantages such as high‐speed applications and solvent‐free formulations at ambient temperature. UV‐curable epoxy acrylate resins containing arylene ether sulfone linkages (EAAES) were synthesized through the condensation of bis(4‐chlorophenyl)sulphone and bisphenol‐A, followed by end‐caping of epichlorohydrin and subsequently acrylic acid. UV‐cured coatings were formulated with epoxy acrylates, reactive diluents such as pentaerythritol tri‐acrylate and pentaerythritol dia‐crylate and photoinitiator. Fourier transfer infrared, 1H NMR, and thermal gravimetrical analysis were employed to investigate the structures and thermal properties of the EAs films. The introduction of EAAES into epoxy acrylate substantially improves its thermal properties and thermo‐oxidative stability at high temperatures. In addition, the acrylate containing arylene ether sulfone linkages can also improve pencil hardness and chemical and solvent resistance of the epoxy acrylate. The obtained UV‐curable epoxy acrylate containing arylene ether sulfone linkages is promising as oligomer for UV‐curable coatings, inks, and adhesives in some high‐tech regions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41067.
Habitat suitability, coverage by protected areas and population connectivity for the Siamese crocodile Crocodylus siamensis Schneider, 1801
Authors: Ihlow Flora , Bonke René , Hartmann Timo , Geissler Peter , Behler Natascha , Rödder Dennis
Published: June 2014

With estimates of fewer than 1000 mature individuals in the wild, the critically endangered Siamese crocodile, Crocodylus siamensis Schneider, 1801, is one of the least known and at the same time most threatened crocodilian species in the world. Populations have already been depleted to approximately 20% of their former size with habitat destruction, alterations, and loss being the main drivers of population declines.

Habitat suitability models were computed using a combination of bioclimatic and remote sensing variables as environmental predictors to evaluate habitat suitability and coverage by designated protected areas across the species’ distributional range. In addition, population connectivity as well as current and future habitat fragmentation through dam construction was assessed by performing population connectivity models.

Habitat suitability models show the spatial extent of suitable habitat to be high (46%), although only a small proportion is covered by designated reserves (11%). Population connectivity models showed remnant populations to be highly fragmented. Considering habitat suitability, coverage of reserves and population connectivity the lower Mekong River Basin stretching from the Xe Champhon and Xe Xangxoy rivers in Lao PDR to the Srepok and Sekong rivers in eastern Cambodia seem to be particularly important for future conservation prioritization for C. siamensis.

The presently established protected area network is unsatisfactory in terms of size and population connectivity and needs to be significantly improved to successfully sustain viable populations of the critically endangered Siamese crocodile in the future.

Copyright © 2014 John Wiley & Sons, Ltd.
Effect of physicochemical parameters on nitrile‐hydrolyzing potentials of newly isolated nitrilase of Fusarium oxysporum f. sp. lycopercisi ED‐3
Authors: Bura Gohain Manorama , Talukdar Shruti , Talukdar Madhumita , Yadav Archana , Gogoi Binod Kumar , Bora Tarun Chandra , Kiran Shashi , Gulati Arvind
Published: June 2014

In recent years, nitrilases from fungus have received increasing attention, and most of the studies are performed on nitrilases of bacterial origin. Frequently used methods are based on analytical methods such as high‐performance liquid chromatography, liquid chromatography–mass spectrometry, and gas chromatography; therefore, an efficient, user friendly, and rapid method has been developed to screen nitrilase enzyme based on the principle of color change of a pH indicator. Phenol red amended with the minimal medium appears light yellow at neutral pH, which changes into pink with the formation of ammonia, indicating nitrilase activity in the reaction medium. A highly potent strain ED‐3 identified as Fusarium oxysporum f. sp. lycopercisi (specific activity 17.5 µmol/Min/mg dcw) was isolated using this method. The nitrilase activity of F. oxysporum f. sp. lycopercisi ED‐3 strain showed wide substrate specificity toward aliphatic nitriles, aromatic nitriles, and orthosubstituted heterocyclic nitriles. 4‐Aminobenzonitrile was found to be a superior substrate among all the nitriles used in this study. This nitrilase was active within pH 5–10 and temperature ranging from 25 to 60 °C with optimal at pH 7.0 and temperature at 50 °C. The nitrilase activity was enhanced to several folds through optimization of culture and biotransformation conditions from 1,121 to 1,941 µmol/Min.
Determination of selenium via the fluorescence quenching effect of selenium on hemoglobin‐catalyzed peroxidative reaction
Authors: Chen Ya‐Hong , Zhang Ya‐Nan , Tian Feng‐Shou
Published: June 2014

A new method for the determination of selenium based on its fluorescence quenching on the hemoglobin‐catalyzed reaction of H2O2 and l‐tyrosine has been established. The effect of pH, foreign ions and the optimization of variables on the determination of selenium was examined. The calibration curve was found to be linear between the fluorescence quenching (F0/F) and the concentration of selenium within the range of 0.16‐4.00 µg/mL. The detection limit was 1.96 ng/mL and the relative standard deviation was 3.14%. This method can be used for the determination of selenium in Se‐enriched garlic bulbs with satisfactory results. Copyright © 2014 John Wiley & Sons, Ltd.
Study on the synthesis of sulfonamide derivatives and their interaction with bovine serum albumin
Authors: Zhang Xuehong , Lin Yijie , Liu Lina , Lin Cuiwu
Published: June 2014

Three sulfonamide derivatives (SAD) were first synthesized from p‐hydroxybenzoic acid and sulfonamides (sulfadimidine, sulfamethoxazole and sulfachloropyridazine sodium) and were characterized by elemental analysis, 1H NMR and MS. The interaction between bovine serum albumin (BSA) and SAD was studied using UV/vis absorption spectroscopy, fluorescence spectroscopy, time‐resolved fluorescence spectroscopy and circular dichroism spectra under imitated physiological conditions. The experimental results indicated that SAD effectively quenched the intrinsic fluorescence of BSA via a static quenching process. The thermodynamic parameters showed that hydrogen bonding and van der Waal's forces were the predominant intermolecular forces between BSA and two SADs [4‐((4‐(N‐(4,6‐dimethylpyrimidin‐2‐yl)sulfamoyl)phenyl)carbamoyl)phenyl acetate and 4‐((4‐(N‐(5‐methylisoxazol‐3‐yl)sulfamoyl)phenyl)carbamoyl)phenyl acetate], but hydrophobic forces played a major role in the binding process of BSA and 4‐((4‐(N‐(6‐chloropyridazin‐3‐yl)sulfamoyl)phenyl) carbamoyl)phenyl acetate. In addition, the effect of SAD on the conformation of BSA was investigated using synchronous fluorescence spectroscopy and circular dichroism spectra. Molecular modeling results showed that SAD was situated in subdomain IIA of BSA. Copyright © 2014 John Wiley & Sons, Ltd.
Electron donation to an archaeal cytochrome P450 is enhanced by PCNA‐mediated selective complex formation with foreign redox proteins
Authors: Suzuki Risa , Hirakawa Hidehiko , Nagamune Teruyuki
Published: June 2014

Cytochrome P450 monooxygenases (P450s) are environmentally friendly biocatalysts that catalyze diverse chemical reactions using molecular oxygen under mild reaction conditions. P450s are activated upon receiving electrons from specific redox partner proteins, although the redox partners for most bacterial/archaeal P450s are not yet identified. Thus, it is important to establish a variety of efficient and versatile electron transfer systems from NAD(P)H to P450s for the design of biocatalysts. Sulfolobus solfataricus possesses a heterotrimeric proliferating cell nuclear antigen (PCNA). Fusion of the PCNA subunits to S. acidocaldarius P450 (CYP119) and the Pseudomonas putida redox proteins, putidaredoxin (PdX) and putidaredoxin reductase (PdR), yielded a selective protein complex containing one molecule each of the three proteins. The PCNA‐mediated heterotrimerization of CYP119, PdX, and PdR enhanced the CYP119 activity, likely as a result of high local concentrations of the two redox proteins toward CYP119. Therefore, the PCNA‐mediated formation of the complex containing PdX and PdR might be applicable for harnessing the utility of P450s whose redox partners are not yet identified.
Lamellar cationic lipid‐DNA complexes from lipids with a strong preference for planar geometry: A Minimal Electrostatic Model
Authors: Perico Angelo , Manning Gerald S.
Published: June 2014

We formulate and analyze a minimal model, based on condensation theory, of the lamellar cationic lipid (CL)‐DNA complex of alternately charged lipid bilayers and DNA monolayers in a salt solution. Each lipid bilayer, composed by a random mixture of cationic and neutral lipids, is assumed to be a rigid uniformly charged plane. Each DNA monolayer, located between two lipid bilayers, is formed by the same number of parallel DNAs with a uniform separation distance. For the electrostatic calculation, the model lipoplex is collapsed to a single plane with charge density equal to the net lipid and DNA charge. The free energy difference between the lamellar lipoplex and a reference state of the same number of free lipid bilayers and free DNAs, is calculated as a function of the fraction of CLs, of the ratio of the number of CL charges to the number of negative charges of the DNA phosphates, and of the total number of planes. At the isoelectric point the free energy difference is minimal. The complex formation, already favoured by the decrease of the electrostatic charging free energy, is driven further by the free energy gain due to the release of counterions from the DNAs and from the lipid bilayers, if strongly charged. This minimal model compares well with experiment for lipids having a strong preference for planar geometry and with major features of more detailed models of the lipoplex. © 2014 Wiley Periodicals, Inc. Biopolymers 101: 1114–1128, 2014.
Chemical data, ways and means, past and future
Authors: Zupan Jure
Published: June 2014

A brief outline of various data handling methods, from linear learning machines, principal component analysis, experimental design, and modeling to visualization, optimization, and validation together with a personal view on the historical development of the use of these methods, is given. Some future trends in handling chemical data are proposed as well. Copyright © 2014 John Wiley & Sons, Ltd.
Mixture Toxicities of Three Pesticides Having Different Time‐Toxicity Profiles
Authors: Yu Mo , Liu Shushen , Wang Mengchao , Chen Fu , Tang Hanxiao
Published: June 2014

In the environment, chemical pollutants always exist as mixtures. To evaluate mixture toxicity, we should examine the concentration ratios and the concentration levels of mixture components as well as the interactive time between the components and testing organism. Selecting three pesticides, metribuzin (MET), dodine (DOD) and ridomil (RID), as mixture components, Vibrio qinghaiensis sp.‐Q67 as testing organism, and 96‐well microplate as exposure experiment carrier, the luminescence inhibition toxicities of the pesticides and their binary mixtures at six exposure time points (0.25, 2, 4, 8, 12, and 16 h) were determined. The results showed that the three pesticides have different time‐toxicity profiles. The toxicity of MET increases over time, and those of DOD and RID show a slight decrease or increase in the first 4 h, respectively, and then remain unchanged to 16 h. The toxicities of the binary mixtures consisting of the three pesticides depend on not only the mixture composition but also the exposure time. The time‐toxicity profiles of all rays in MET‐DOD mixture system are U‐shaped curves, those in MET‐RID system are basically monotonically increased and those in DOD‐RID system are basically monotonically decreased. However, our findings indicate that for the test substances, mixture toxicity can be predicted by the extended concentration addition model.
Fc‐PIP Catalyzed Asymmetric Synthesis of cis‐2,3‐Dihydrobenzofurans
Authors: Jiang Shanshan , Hu Bin , Yu Xingxin , Deng Weiping
Published: June 2014

A highly enantioselective intramolecular Michael addition‐Lactonization domino reaction of a range of enon acids catalyzed by nuleophilic organocatalyst (Fc‐PIP) was developed, furnishing cis‐2,3‐dihydrobenzofuran derivatives with excellent enantioselecitivities (94%–98% ee) and good diastereoselectivities (up to 99/1).