bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of diet quality on chronic toxicity of aqueous lead to the amphipod Hyalella azteca
Authors: Besser John M. , Ivey Chris D. , Brumbaugh William G. , Ingersoll Christopher G. 
Published: December 2015

Abstract

The authors investigated the chronic toxicity of aqueous Pb to the amphipod Hyalella azteca (Hyalella) in 42-d tests using 2 different diets: 1) the yeast + cereal leaf + trout pellet (YCT) diet, fed at the uniform low ration used in standard methods for sediment toxicity tests; and 2) a new diet of diatoms + TetraMin flakes (DT), fed at increasing rations over time, that has been optimized for use in Hyalella water-only tests. Test endpoints included survival, weight, biomass, fecundity, and total young. Lethal effects of Pb were similar for the DT and YCT tests (20% lethal concentration [LC20] = 13 μg/L and 15 μg/L, respectively, as filterable Pb). In contrast, weight and fecundity endpoints were not significantly affected in the DT test at Pb concentrations up to 63 µg/L, but these endpoints were significantly reduced by Pb in the YCT test—and in a 2005 test in the same laboratory with a diet of conditioned Rabbit Chow (RC-2005). The fecundity and total young endpoints from the YCT and RC-2005 tests were considered unreliable because fecundity in controls did not meet test acceptability criteria, but both of these tests still produced lower Pb effect concentrations (for weight or biomass) than the test with the DT diet. The lowest biotic ligand model–normalized effect concentrations for the 3 tests ranged from 3.7 μg/L (weight 20% effect concentration [EC20] for the RC-2005 test) to 8.2 μg/L (total young EC20 for the DT test), values that would rank Hyalella as the second or third most sensitive of 13 genera in a species sensitivity distribution for chronic Pb toxicity. These results demonstrate that toxicity tests with Hyalella fed optimal diets can meet more stringent test acceptability criteria for control performance, but suggest that results of these tests may underestimate sublethal toxic effects of Pb to Hyalella under suboptimal feeding regimes. Environ Toxicol Chem 2016;35:1825–1834. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and as such, is in the public domain in the United States of America.
A test of the additivity of acute toxicity of binary-metal mixtures of ni with Cd, Cu, and Zn to Daphnia magna, using the inflection point of the concentration–response curves
Authors: Traudt Elizabeth M. , Ranville James F. , Smith Samantha A. , Meyer Joseph S. 
Published: December 2015

Abstract

Mixtures of metals are often present in surface waters, leading to toxicity that is difficult to predict. To provide data for development of multimetal toxicity models, Daphnia magna neonates were exposed to individual metals (Cd, Cu, Ni, Zn) and to binary combinations of those metals in standard 48-h lethality tests conducted in US Environmental Protection Agency moderately hard reconstituted water with 3 mg dissolved organic carbon (DOC)/L added as Suwannee River fulvic acid. Toxicity tests were performed with mixtures of Ni and 1) Cd, which is considerably more toxic than Ni; 2) Cu, which is less toxic than Cd but more toxic than Ni; and 3) Zn, which has a toxicity threshold similar to Ni. For each combination of metals in the binary mixtures, the concentration of 1 metal was held constant while the second metal was varied through a series that ranged from nonlethal to lethal concentrations; then the roles of the metals were reversed. Inflection points of the concentration–response curves were compared to test for additivity of toxicity. Sublethal concentrations of Ni caused less-than-additive toxicity with Cd, slightly less-than-additive toxicity with Zn, and greater-than-additive toxicity with Cu. One explanation of these results might be competition among the metals for binding to biological ligands and/or dissolved organic matter. Therefore, models might have to incorporate sometimes competing chemical interactions to accurately predict metal-mixture toxicity. Environ Toxicol Chem 2016;35:1843–1851. © 2015 SETAC
Isotopic exchange on solid-phase micro extraction fiber in sediment under stagnant conditions: Implications for field application of performance reference compound calibration
Authors: Bao Lian-Jun , Wu Xiaoqin , Jia Fang , Zeng Eddy Y. , Gan Jay 
Published: December 2015

Abstract

An overlooked issue for field application of in situ performance reference compound (PRC) calibration methods is the validity of the assumption that both the sorption of a target compound and desorption of its corresponding PRC follow the first-order kinetics with the same rate constants under stagnant conditions. In the present study, disposable polydimethylsiloxane fibers of 2 sizes (7 and 35 µm) impregnated with 8 13C-labeled or deuterated PRCs were statically deployed into different marine sediments, from which the kinetics for sorption of the target compounds and desorption of the PRCs were characterized. Nonsymmetrical profiles were observed for exchange of the target analytes and their corresponding PRCs in sediment under stagnant conditions. The hysteretic desorption of PRCs in the kinetic regime may be ascribed to the low chemical potential between the fiber and sediment porewater, which reflects the inability of water molecules to rapidly diffuse through sediment to solvate the PRCs in the aqueous layer around the fiber surface. A moderate correlation (r = 0.77 and r = 0.57, p &lt; 0.05 for both regressions) between the PRC-calibrated equilibrium concentrations of 1,1-dichloro-2,2-bis-(chlorophenyl) ethylene (p,p′-DDE) and polychlorinated biphenyl (PCB)-153 and the lipid normalized levels in worms (Neanthes arenaceodentata) was obtained in co-exposure tests under simulating field conditions, probably resulting from slightly overestimated bioavailability because of the hysteretic desorption of PRCs and toxic effects. Environ Toxicol Chem 2016;35:1978–1985. © 2015 SETAC
Factors related to prevalence, persistence, and incidence of depressive symptoms in mild cognitive impairment: vascular depression construct
Authors: Kim Sangha , Woo Sook Young , Kang Hyo Shin , Lim Shin Won , Choi Seong Hye , Myung Woojae , Jeong Jee Hyang , Lee Yunhwan , Hong Chang Hyung , Kim Jong Hun , Na HaeRi , Carroll Bernard J. , Kim Doh Kwan 
Published: December 2015

ObjectiveDepression is prevalent among elders with cognitive impairment. Cerebral white matter hyperintensities (WMH) have consistently been implicated in late‐life depression and in cognitive impairment. This study aims to clarify the factors related to prevalence, persistence, and new onset of depressive symptoms in subjects with mild cognitive impairment (MCI).MethodsAs part of a multicenter prospective study, the Clinical Research Center for Dementia of South Korea (CREDOS) Study, we enrolled 590 subjects diagnosed with MCI and with no prior history of depression. Depressive symptoms were assessed by the Korean version of the Geriatric Depression Scale short form (SGDS‐K) at baseline and at follow‐up visits. Brain magnetic resonance imaging was performed at baseline to quantify WMH using a visual rating scale.ResultsThe baseline prevalence of clinically significant depressive symptoms (SGDS‐K ≥5) was 51.4%, and this feature was associated with younger age, lower educational achievement, and higher Clinical Dementia Rating Sum of Boxes (CDR‐SB) scores. Persistence of depressive symptoms across the study period was significantly associated with baseline CDR‐SB and depression scores. New onset of depression (SGDS‐K ≥8; incidence 15.7%) among subjects free of depressive symptoms (SGDS‐K <5) at baseline was associated with severe deep subcortical, but not periventricular, WMH.ConclusionsIn patients with MCI aged 50 years or older, depressive symptoms were highly prevalent. Cognitive status was closely related to both prevalence and persistence of depressive symptoms, while new onset of depression was associated with deep subcortical WMH severity in this MCI cohort. Our findings provide prospective evidence consistent with the vascular depression hypothesis. Copyright © 2015 John Wiley & Sons, Ltd.
Use of TachoSil® patches to prevent pancreatic leaks after distal pancreatectomy: a prospective, multicenter, randomized controlled study
Authors: Park Joon Seong , Lee Doo‐ho , Jang Jin‐Young , Han Youngmin , Yoon Dong Sup , Kim Jae Keun , Han Ho‐Seong , Yoon YooSeok , Hwang DaeWook , Kang Chang Moo , Hwang Ho Kyoung , Lee Woo Jung , Heo JinSeok , Chang Ye Rim , Kang Mee Joo , Shin Yong Chan , Chang Jihoon , Kim Hongbeom , Jung Woohyun , Kim Sun‐Whe 
Published: December 2015

AbstractBackgroundWe performed a prospective, multicenter, randomized controlled study to investigate the clinical outcomes, including postoperative pancreatic fistulas (POPF), after using the TachoSil® patch in distal pancreatectomy (NCT01550406).MethodsBetween June 2012 and September 2014, 101 patients at five centers were randomized into Control (n = 53) and TachoSil (n = 48) groups. In all patients, the pancreas was resected using a stapler with Endo‐GIA™ staples. The TachoSil patch was wrapped around the pancreatic stump only in the TachoSil group, not in Control group.ResultsThe patient characteristics, including age and diagnosis, were comparable in both groups. The mean operation time (159.4 vs. 172.3 min, P = 0.081) and postoperative hospital stay (10.0 vs. 9.7 days, P = 0.279) were similar in the Control and TachoSil groups, respectively. The overall incidence of POPF was 62.4% (n = 63). The distribution of grades A, B, and C POPF was similar in the Control (n = 14/14/1) and TachoSil (n = 23/11/0) groups, as were the overall incidence (54.7% vs. 70.8%, P = 0.095) and the incidence of grade B and C POPF (28.3% vs. 22.9%, P = 0.536).ConclusionThis study showed that the TachoSil® patch did not reduce the incidence of POPF after distal pancreatectomy.
BMP‐2 delivered via sucrose acetate isobutyrate (SAIB) improves bone repair in a rat open fracture model
Authors: Cheng Tegan L. , Schindeler Aaron , Little David G. 
Published: December 2015

ABSTRACTHuman bone morphogenetic proteins (BMPs) are an alternative to bone graft for the treatment of high‐energy open fractures. The standard delivery system for BMP‐2 is a porous collagen sponge, but we have previously found that the biocompatible, high viscosity carrier, Sucrose acetate isobutyrate (SAIB) is an effective and potentially less invasive alternative. The efficacy of SAIB as a BMP‐2 delivery system was examined in an open fracture model featuring a femoral osteotomy with periosteal stripping in 9‐week‐old male Sprague Dawley rats. SAIB containing BMP‐2 (SAIB/BMP‐2) was delivered into the fracture site during surgery and an additional group was further co‐treated with zoledronic acid and hydroxyapatite nanoparticles (SAIB/BMP‐2/HA/ZA). These were compared to untreated fractures and SAIB carrier alone (negative controls), and BMP‐2 loaded collagen sponge (positive control). The rate of radiographic union and the biomechanical properties of the healed fractures were compared after 6–week. Untreated and SAIB‐treated fractures showed poor repair, with 53% and 64%, respectively, not bridged at 6 week. In contrast, collagen/BMP‐2, SAIB/BMP‐2, and SAIB/BMP‐2/HA/ZA showed significantly increased union (100%, 100%, and 94%, respectively, p < 0.05). Four‐point bend testing revealed that collagen/BMP‐2 and SAIB/BMP‐2/HA/ZA restored the strength of fractured femora to that of intact femora by 6 week, whereas untreated and SAIB remained less than intact controls by 60% and 67%, respectively (p < 0.05). Overall, the SAIB/BMP‐2/HA/ZA formulation was comparable to BMP‐2 infused collagen sponge in terms of promoting open fractures repair, but with the additional potential for less invasive delivery. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1168–1176, 2016.
Phytase‐mediated mineral solubilization from cereals under in vitro gastric conditions
Authors: Nielsen Anne VF , Meyer Anne S 
Published: December 2015

AbstractBACKGROUNDEnzymatic dephosphorylation of phytic acid (inositol hexakisphosphate) in cereals may improve mineral bioavailability in humans. This study quantified enzymatic dephosphorylation of phytic acid by measuring inositol tri‐ to hexakisphosphate (InsP3–6) degradation and iron and zinc release during microbial phytase action on wheat bran, rice bran and sorghum under simulated gastric conditions.RESULTSInsP3–6 was depleted within 15–30 min of incubation using an Aspergillus niger phytase or Escherichia coli phytase under simulated gastric conditions, with the two enzymes dephosphorylating cereal phytic acid at similar rates and to similar extents. Microbial phytase‐catalyzed phytate dephosphorylation was accompanied by increased iron and zinc release from the cereal substrates. However, for wheat bran at pH 5, the endogenous wheat phytase activity produced mineral release equal to or better than that of the microbial phytases. No increases in soluble cadmium, lead or arsenic were observed with microbial phytase‐catalyzed phytate dephosphorylation.CONCLUSIONMicrobial phytase treatment abated phytate chelation hence enhanced the release of iron and zinc from phytate‐rich cereals under simulated gastric conditions. The data infer that acid‐stable microbial phytases can help improve iron bioavailability from phytate‐rich cereal substrates via post‐ingestion activity. © 2015 Society of Chemical Industry
Simple and rapid determination of phthalates using microextraction by packed sorbent and gas chromatography with mass spectrometry quantification in cold drink and cosmetic samples
Authors: Kaur Ramandeep ,   Heena , Kaur Ripneel , Rani Susheela , Malik Ashok Kumar 
Published: December 2015

A simple and rapid method using microextraction by packed sorbent coupled with gas chromatography and mass spectrometry has been developed for the analysis of five phthalates, namely, diethyl phthalate, benzyl‐n‐butyl phthalate, dicyclohexyl phthalate, di‐n‐butyl phthalate, and di‐n‐propyl phthalate, in cold drink and cosmetic samples. The various parameters that influence the microextraction by packed sorbent performance such as extraction cycle (extract–discard), type and amount of solvent, washing solvent, and pH have been studied. The optimal conditions of microextraction using C18 as the packed sorbent were 15 extraction cycles with water as washing solvent and 3 × 10 μL of ethyl acetate as the eluting solvent. Chromatographic separation was also optimized for injection temperature, flow rate, ion source, interface temperature, column temperature gradient and mass spectrometry was evaluated using the scan and selected ion monitoring data acquisition mode. Satisfactory results were obtained in terms of linearity with R2 >0.9992 within the established concentration range. The limit of detection was 0.003–0.015 ng/mL, and the limit of quantification was 0.009–0.049 ng/mL. The recoveries were in the range of 92.35–98.90% for cold drink, 88.23–169.20% for perfume, and 88.90–184.40% for cream. Analysis by microextraction by packed sorbent promises to be a rapid method for the determination of these phthalates in cold drink and cosmetic samples, reducing the amount of sample, solvent, time and cost.
Comparison of the Performance of Two Bifunctional Curing Agents for the Photopolymerization of Epoxy Resins and the Study of the Mechanical Properties of the Obtained Polymers
Authors: Acosta Ortiz Ricardo , García Valdez Aída E. , Sangermano Marco , Hilario de la Cruz Adrián A. , Aguirre Flores Rafael , Espinoza Muñoz Jorge Félix 
Published: December 2015

SummaryThis work presents a new method for photocuring epoxy resins using bifunctional curing agents. These curing agents are tertiary amines functionalized with allyl groups. The tertiary amines can cure the epoxy resins by anionic ring opening polymerization of the oxirane groups while the allyl groups react with an added multifunctional thiol by the thiol–ene mechanism. The results showed that the produced polythioethers enhanced the toughness of the obtained polyethers. The kinetics of photopolymerization and the analysis of mechanical properties of the polymers are presented.
Influence of Novel Crosslinker on the Properties of the Degradable Thermosensitive Hydrogels
Authors: Lee Wen‐Fu , Lu Ying‐Yi 
Published: December 2015

SummaryA novel degradable crosslinker, N, N′‐bis(acryloyl) cystamine (BACy), was synthesized with cystamine dihydrochloride (Cy) and acryloyl chloride. Then three series of degradable thermosensitive hydrogels with different crosslinker contents were prepared from N‐isopropyl acrylamide (NIPAAm), BACy (Bx‐series) or N, N′‐methylene‐bis‐acrylamide (NMBA)(Nx‐series) or equimolar BACy and NMBA (BNx‐series) as crosslinker, and diethoxyacetophenone (DEAP) as photoinitiator under UV‐irradiation polymerization. The effect of crosslinker content on the properties of the hydrogels such as swelling behavior and mechanical properties was investigated. At the same time, their degradabilities were investigated by dissolving them into different concentrations of cysteine solution. The results show that the swelling ratios for the Bx‐series hydrogels are lower than those for the Nx‐series hydrogels. But, after degradation in the cysteine solution, the swelling ratios for the Bx‐series hydrogels were greater than those for the Nx‐series hydrogels. When the crosslinker content was increased, all values of shear stress (τ), shear modulus (G), and effective crosslinking density (ρX) increased. But, the ρX values for the reduced Bx series and BNx series hydrogels were lower than those for original hydrogels. Results also showed that the ρX values for the Nx series hydrogel were not affected by cysteine. The disulfide bonds of BACy in these novel hydrogels were decomposed (reduced) in the cysteine solution and converted into thiol group. These thiol groups could be used to absorb some metal ions such as silver ion. Hence, the absorption of silver ion for the hydrogel with thiol group was also investigated in this research.
Implementation of regularized isogeometric boundary element methods for gradient‐based shape optimization in two‐dimensional linear elasticity
Authors: Lian Haojie , Kerfriden Pierre , Bordas Stéphane P. A. 
Published: December 2015

SummaryThe present work addresses shape sensitivity analysis and optimization in two‐dimensional elasticity with a regularized isogeometric boundary element method (IGABEM). Non‐uniform rational B‐splines are used both for the geometry and the basis functions to discretize the regularized boundary integral equations. With the advantage of tight integration of design and analysis, the application of IGABEM in shape optimization reduces the mesh generation/regeneration burden greatly. The work is distinct from the previous literatures in IGABEM shape optimization mainly in two aspects: (1) the structural and sensitivity analysis takes advantage of the regularized form of the boundary integral equations, eliminating completely the need of evaluating strongly singular integrals and jump terms and their shape derivatives, which were the main implementation difficulty in IGABEM, and (2) although based on the same Computer Aided Design (CAD) model, the mesh for structural and shape sensitivity analysis is separated from the geometrical design mesh, thus achieving a balance between less design variables for efficiency and refined mesh for accuracy. This technique was initially used in isogeometric finite element method and was incorporated into the present IGABEM implementation. Copyright © 2016 John Wiley & Sons, Ltd.
Software‐aided cytochrome P450 reaction phenotyping and kinetic analysis in early drug discovery
Authors: Cece‐Esencan Esra Nurten , Fontaine Fabien , Plasencia Guillem , Teppner Marieke , Brink Andreas , Pähler Axel , Zamora Ismael 
Published: December 2015

RationaleCytochrome P450 (CYP450) reaction phenotyping (CRP) and kinetic studies are essential in early drug discovery to determine which metabolic enzymes react with new drug entities. A new semi‐automated computer‐assisted workflow for CRP is introduced in this work. This workflow provides not only information regarding parent disappearance, but also metabolite identification and relative metabolite formation rates for kinetic analysis.MethodsTime‐course experiments based on incubating six probe substrates (dextromethorphan, imipramine, buspirone, midazolam, ethoxyresorufin and diclofenac) with recombinant human enzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4) and human liver microsomes (HLM) were performed. Liquid chromatography/high‐resolution mass spectrometry (LC/HRMS) analysis was conducted with an internal standard to obtain high‐resolution full‐scan and MS/MS data. Data were analyzed using Mass‐MetaSite software. A server application (WebMetabase) was used for data visualization and review.ResultsCRP experiments were performed, and the data were analyzed using a software‐aided approach. This automated‐evaluation approach led to (1) the detection of the CYP450 enzymes responsible for both substrate depletion and metabolite formation, (2) the identification of specific biotransformations, (3) the elucidation of metabolite structures based on MS/MS fragment analysis, and (4) the determination of the initial relative formation rates of major metabolites by CYP450 enzymes.ConclusionsThis largely automated workflow enabled the efficient analysis of HRMS data, allowing rapid evaluation of the involvement of the main CYP450 enzymes in the metabolism of new molecules during drug discovery. Copyright © 2015 John Wiley & Sons, Ltd.
Glutamine deamidation: an indicator of antiquity, or preservational quality?
Authors: Schroeter Elena R. , Cleland Timothy P. 
Published: December 2015

RationaleMuch credence has been given in the paleoproteomic community to glutamine deamidation as a proxy for the age of proteins derived from fossil and subfossil material, and this modification has been invoked as a means for determining the endogeneity of molecules recovered from very old fossil specimens.MethodsWe re‐evaluated the relationship between glutamine deamidation and geologic time by examining previously published data from five recent mass spectrometry studies of archeaological fossils. Deamidation values recovered for fossils were graphed against their reported chronologic age using WebPlotDigitizer.ResultsThe experimental data that has been produced from fossil material to date show that the extent of glutamine deamidation does not correspond to the absolute age of the specimens being examined, but rather show extreme variation between specimens of similar age and taxonomic affinity.ConclusionsBecause deamidation rates and levels can be greatly affected by numerous chemical and environmental factors, we propose that glutamine deamidation is better suited as an indicator of preservational quality and/or environmental conditions than a mark of the endogeneity or authenticity of ancient proteins. Copyright © 2015 John Wiley & Sons, Ltd.