bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observed trends of soil fauna in the Antarctic Dry Valleys: early signs of shifts predicted under climate change
Authors: Andriuzzi W. S. , Adams B. J. , Barrett J. E. , Virginia R. A. , Wall D. H. 
Published: January 2018

AbstractLong‐term observations of ecological communities are necessary for generating and testing predictions of ecosystem responses to climate change. We investigated temporal trends and spatial patterns of soil fauna along similar environmental gradients in three sites of the McMurdo Dry Valleys, Antarctica, spanning two distinct climatic phases: a decadal cooling trend from the early 1990s through the austral summer of February 2001, followed by a shift to the current trend of warming summers and more frequent discrete warming events. After February 2001, we observed a decline in the dominant species (the nematodeScottnema lindsayae) and increased abundance and expanded distribution of less common taxa (rotifers, tardigrades, and other nematode species). Such diverging responses have resulted in slightly greater evenness and spatial homogeneity of taxa. However, total abundance of soil fauna appears to be declining, as positive trends of the less common species so far have not compensated for the declining numbers of the dominant species. Interannual variation in the proportion of juveniles in the dominant species was consistent across sites, whereas trends in abundance varied more. Structural equation modeling supports the hypothesis that the observed biological trends arose from dissimilar responses by dominant and less common species to pulses of water availability resulting from enhanced ice melt. No direct effects of mean summer temperature were found, but there is evidence of indirect effects via its weak but significant positive relationship with soil moisture. Our findings show that combining an understanding of species responses to environmental change with long‐term observations in the field can provide a context for validating and refining predictions of ecological trends in the abundance and diversity of soil fauna.
Enhancing the Catalytic Performance of Candida antarctica Lipase B by Immobilization onto the Ionic Liquids Modified SBA‐15
Authors: Zhong Nanjing , Li Yue , Cai Chunsheng , Gao Yongqing , Liu Ning , Liu Guoqin , Tan Wenying , Zeng Yaoying 
Published: January 2018

In this study, mesoporous silica SBA‐15 is modified by imidazole based ionic liquids (IL) with three different side‐chain length of cations and two different anions. Prepared supports (IL‐SBA‐15) are characterized by small‐angle powder X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) as well as Fourier transform infrared (FT‐IR), and then used to immobilize Candida antarctica lipase B (CALB). The enzymatic properties of the obtained IL‐SBA‐15‐CALB are evaluated, and the catalytic selectivity toward diacylglycerols (DAG) production in glycerolysis of triacylglycerols (TAG) reaction is also studied. Compared with the parent SBA‐15 immobilized CALB (SBA‐15‐CALB), the IL modification gives a maximum improvement of enzymatic activity from 1855 to 5044 U g−1; in addition, the selectivity toward the diacylglycerols (DAG) production also increases, with the DAG/MAG ratio increasing from 3.72 to 11.99, and the DAG content increasing from 53.6 to 67.2 wt%.Practical applications: Immobilization of lipases facilitates the separation of products and the recovery of lipases for reuse. The present study shows that CALB immobilized on the IL modified SBA‐15 is potential for DAG production through glycerolysis, due to its considerable reusability as well as its high glycerolysis activity and selectivity toward DAG production, it could be considered for practical applications.Glycerolysis of corn oil catalyzed by ionic liquids modified SBA‐15 supports CALB to produce diacylglycerols. SBA‐15 is modified by ionic liquids, and then employed as carrier for Candida antarctica lipase B (CALB) immobilization. The obtained solid lipases are used to catalyze glycerolysis for diacylglycerols (DAG) production. Compared with the parent SBA‐15 immobilized CALB (SBA‐15‐CALB), ionic liquids modification gives a maximum improvement of enzymatic activity from 1855 to 5044 U g−1; in addition, the selectivity toward the DAG production is also increased, with the DAG/MAG ratio increasing from 3.72 to 11.99, and the DAG content increasing from 53.6 to 67.2 wt%.
Influence of emotional valence on perceived psychological distance depends on emotional intensity
Authors: Mei Dongmei , Li Liman Man Wai , Wang Yiheng 
Published: January 2018

AbstractPrevious findings regarding the relationship between emotional valence and psychological distance were mixed. The current research examined whether emotional intensity moderates the influence of emotional valence on psychological distance. We manipulated intensity and valence by asking participants to describe a positive or negative event from either a high intensity or low intensity perspective. Studies 1 and 2 revealed that negative events were perceived to be more distant than positive events in the low‐intensity condition in two distinct cultural groups. Study 3 further proved that the obtained patterns were generalizable to different emotions. Finally, Study 4 found that a reduced alert level, but not perceived threats, mediated the interactive effects of valence and intensity on psychological distance. This research highlights the importance of considering the joint effect of different dimensions of emotion, thus advancing the understanding of complex processes of emotion.
Studies of Electrode Reactions and Coordination Geometries of Cu(I) and Cu(II) Complexes with Bicinchoninic Acid
Authors: Chen Dinglong , Wang Xiaoying , He Yonghui , Kai Tianhan , Li Zhiqiang , Xiang Juan , Jiang Dianlu , Zhou Feimeng 
Published: January 2018

AbstractBicinchoninic acid (BCA) is widely used for determining the valence state of copper in biological systems and quantification of the total protein concentration (BCA assay). Despite its well‐known high selectivity of Cu(I) over Cu(II), the exact formation constants for Cu(I)(BCA)23− and Cu(II)(BCA)22− complexes remain uncertain. These uncertainties, affect the correct interpretations of the roles of copper in biological processes and the BCA assay data. By studying the voltammetric behaviors of Cu(I)(BCA)23− and Cu(II)(BCA)22−, we demonstrate that the apparent lack of redox reaction reversibility is caused by an adsorption wave of Cu(II)(BCA)22−. With the adsorption wave identified, we found that the Cu(I)/Cu(II) selectivity of BCA is essentially identical to another popular ligand, bathocuproinedisulfonic acid (BCS). Density functional theory calculation on the geometries of Cu(I)(BCA)23− and Cu(II)(BCA)22− rationalizes the preferential Cu(I) binding by BCA and the strong adsorption of the Cu(II)(BCA)22− complex at the glassy carbon electrode. Based on the shift in the standard reduction potential of free Cu(II)/Cu(I) upon binding to BCA, we affirm that the formation constants for Cu(I)(BCA)23− and Cu(II)(BCA)22− are 1017.2 and 108.9, respectively. Therefore, BCA can be chosen among various ligands for effective and reliable studies of the copper binding affinities of different biomolecules.
Assay of Glomalin Using a Quartz Crystal Microbalance Biosensor
Authors: Pohanka Miroslav , Vlcek Vitezslav 
Published: January 2018

AbstractGlomalin is a soil protein abundantly occurring in the soil. In the current time, knowledge about glomalin is limited and there are also missing simple test for the determination of glomalin in the environment. This work is devoted to construction of a biosensor which is expected to be a simple device for the determination of glomalin in extracts from soil samples. The biosensor was constructed using an antibody against glomalin and piezoelectric quartz crystal microbalance (QCM) sensor platform allowing label free assay. Electrodes of QCM were activated using cysteamine and glutaraldehyde and finally, an antibody against glomalin was immobilized. Glomalin was acquired from various soil samples by extraction in an autoclave and its content was determined by a standard spectrophotometric test. Time necessary to bind sufficient amount of glomalin was discovered for the biosensor and four hours incubation interval corresponded with maximal efficacy. Limit of detection for the biosensor based assay was found to be equal to 3.40 μg/g which is enough to cover all the tested soil samples containing glomalin in a concentration from 291 μg/g to 3.47 mg/g. The assay also fully correlated with the standard tests. In a conclusion, the piezoelectric biosensor seems to be a suitable platform for the determination of glomalin in samples of environment origin. The method represents an improvement of the current analytical platforms that are based on measurement of total protein content in soil extract.
Preparation of β‐cyclodextrin‐gold nanoparticles modified open tubular column for capillary electrochromatographic separation of chiral drugs
Authors: Zhou Li , Jiang Shenmeng , Zhang Xue , Fang Linlin , Guo Xingjie 
Published: January 2018

AbstractIn this paper, β‐cyclodextrin (β‐CD) modified gold nanoparticles (AuNPs) coated open tubular column (OT column) was prepared for capillary electrochromatography. The open tubular column was constructed through self‐assembly of gold nanoparticles on 3‐mercaptopropyl‐trimethoxysilane (MPTMS) prederivatized capillary and subsequent modification of thiols β‐cyclodextrin (SH‐β‐CD). Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet visible spectroscopy were carried out to characterize the prepared open tubular column and synthesized gold nanoparticles. By comparing different coating times of gold nanoparticles and thiols β‐cyclodextrin, we got the optimal conditions for preparing the open tubular column. Also, the separation parameters were optimized including buffer pH, buffer concentration and applied voltage. Separation effectiveness of open tubular column was verified by the separation of four pairs of drug enantiomers including bifonazole, fexofenadine, omeprazole and lansoprazole, and satisfactory separation results were achieved for these analytes studied. In addition, the column showed good stability and repeatability. The relative standard deviation values less than 5% were obtained through intra‐day, inter‐day, and column‐to‐column investigations.
Postoperative EEG association with seizure recurrence: Analysis of the NIH epilepsy surgery database
Authors: Hodges Sarah , Goldenholz Daniel M. , Sato Susumu , Theodore William H. , Inati Sara 
Published: January 2018

SummaryThe epilepsy surgery database from 1984 to 2012 at the National Institutes of Health (NIH) was reviewed to determine the association of postoperative electroencephalography (EEG) with seizure recurrence. Eighty‐three patients were analyzed, with 41 having at least 5 years of follow‐up. The relationship between epileptiform postoperative EEG findings and seizure recurrence at 1, 2, and 5 years was not significant, despite a significant decrease in abnormal EEG recordings after surgery. Clinicians use a variety of tools to predict seizure recurrence following epilepsy surgery to guide medication management and to modulate patient expectations. EEG is but one tool for assessing the likelihood of seizure recurrence following epilepsy surgery.
Experimental and numerical behaviour of dissipative devices based on carbon‐wrapped steel tubes for the retrofitting of existing precast RC structures
Authors: Pollini Andrea Vittorio , Buratti Nicola , Mazzotti Claudio 
Published: January 2018

SummaryThe 2012 Emilia earthquake (in Northern Italy) caused extensive damage to existing prefabricated reinforced concrete structures. These buildings were found being extremely vulnerable because, being designed for vertical loads only, they featured friction‐based connections between structural elements, most commonly between beams and columns. Given the large diffusion of these structures, their seismic retrofit is critical. Various techniques have been proposed in the literature, in most of which friction‐based connections are removed by inserting mechanical connectors that will make beam‐column connections hinged. These approaches lead to a significant increase of the base shear and therefore require strengthening of columns.The paper presents dissipative devices based on carbon‐wrapped steel tubes to be used as an alternative low‐damage solution for the retrofit of beam‐column connections. The first part of the paper presents results of experimental tests on the devices and discusses their dissipative behaviour. The succeeding parts of the paper present numerical analyses on simple structures reinforced with the proposed device. The results of the numerical study show how the introduction of the dissipative devices produces a significant reduction of forces transmitted to the structure, by comparing the seismic response of simple frame structures equipped with dissipative devices with the response of equivalent elastic systems.
Trophic transfer of Cd from duckweed (Lemna minor L.) to tilapia (Oreochromis mossambicus)
Authors: Xue Yan , Peijnenburg Willie J.G.M. , Huang Jin , Wang Dengjun , Jin Yan 
Published: January 2018

Abstract

The transfer of the toxic heavy metal Cd from duckweed (Lemna minor L.) to the freshwater fish tilapia (Oreochromis mossambicus) was investigated. Concentrations of Cd in different chemical forms in duckweed and in different tissues (gut, edible muscle, and remnants or residual) of tilapia (i.e., ethanol-extractable fraction [FE], HCl-extractable fraction [FHCl], and residual fraction [FR]) were quantified, and the bioaccumulation factors (BAFs) of Cd in the tilapia body were calculated. Simple linear regression analysis was used to unravel the correlation and accumulation mechanisms of Cd along the short food chain. Our results showed that with increasing exposure concentrations of Cd (0–50 μM for duckweed and 0–10 μM for tilapia), the total, FE (Fe,d)-, FHCl (Fh,d)-, and FR (Fr,d)-Cd concentrations in duckweed and different tissues of tilapia increased progressively. The Cd sources (aqueous or dietary) influenced the BAF for Cd accumulation in the whole body of tilapia. Furthermore, regression analyses yielded significant positive correlations (R2 &gt; 0.96) between the Cd concentration in duckweed and in both the 3 parts and the whole body of tilapia. This finding suggests that Cd transfer from duckweed to tilapia can be quantitatively evaluated when tilapia is exposed only to duckweed. In addition, the linear regression between Cd accumulation in whole tilapia and Fe,d-, Fh,d-, and Fr,d-Cd showed that particularly the correlation with Fe,d-Cd is statistically significant (p &lt; 0.001). The accumulated Cd concentrations and chemical forms in tilapia tissues also positively correlated with Cd sources (solution or duckweed). Compared with waterborne exposure only, duckweed especially increased the accumulation of Cd in the gut of tilapia. Taken together, our findings support a strong dependence of Cd accumulation and transfer from duckweed to tilapia on its chemical forms, especially on Fe,d-Cd. This knowledge may expedite more accurate risk assessment of heavy metals through aquatic food chain ecosystems. Environ Toxicol Chem 2018;37:1367–1377. © 2018 SETAC
Bioconcentration model for non-ionic, polar, and ionizable organic compounds in amphipod
Authors: Chen Ciara Chun , Kuo Dave Ta Fu 
Published: January 2018

Abstract

The present study presents a bioconcentration model for non-ionic, polar, and ionizable organic compounds in amphipod based on first-order kinetics. Uptake rate constant k1 is modeled as logk1=10.81logKOW + 0.15 (root mean square error [RMSE] = 0.52). Biotransformation rate constant kM is estimated using an existing polyparameter linear free energy relationship model. Respiratory elimination k2 is calculated as modeled k1 over theoretical biota–water partition coefficient Kbiow considering the contributions of lipid, protein, carbohydrate, and water. With negligible contributions of growth and egestion over a typical amphipod bioconcentration experiment, the bioconcentration factor (BCF) is modeled as k1/(kM + k2) (RMSE = 0.68). The proposed model performs well for non-ionic organic compounds (log KOW range = 3.3–7.62) within 1 log-unit error margin. Approximately 12% of the BCFs are underpredicted for polar and ionizable compounds. However, &gt;50% of the estimated k2 values are found to exceed the total depuration rate constants. Analyses suggest that these excessive k2 values and underpredicted BCFs reflect underestimation in Kbiow, which may be improved by incorporating exoskeleton as a relevant partitioning component and refining the membrane–water partitioning model. The immediate needs to build up high-quality experimental kM values, explore the sorptive role of exoskeleton, and investigate the prevalence of k2 overestimation in other bioconcentration models are also identified. The resulting BCF model can support, within its limitations, the ecotoxicological and risk assessment of emerging polar and ionizable organic contaminants in aquatic environments and advance the science of invertebrate bioaccumulation. Environ Toxicol Chem 2018;37:1378–1386. © 2018 SETAC
Four‐way multimodal fusion of 7 T imaging data using an mCCA+jICA model in first‐episode schizophrenia
Authors: Lottman Kristin K. , White David M. , Kraguljac Nina V. , Reid Meredith A. , Calhoun Vince D. , Catao Fabio , Lahti Adrienne C. 
Published: January 2018

AbstractAcquisition of multimodal brain imaging data for the same subject has become more common leading to a growing interest in determining the intermodal relationships between imaging modalities to further elucidate the pathophysiology of schizophrenia. Multimodal data have previously been individually analyzed and subsequently integrated; however, these analysis techniques lack the ability to examine true modality inter‐relationships. The utilization of a multiset canonical correlation and joint independent component analysis (mCCA + jICA) model for data fusion allows shared or distinct abnormalities between modalities to be examined. In this study, first‐episode schizophrenia patients (nSZ=19) and matched controls (nHC=21) completed a resting‐state functional magnetic resonance imaging (fMRI) scan at 7 T. Grey matter (GM), white matter (WM), cerebrospinal fluid (CSF), and amplitude of low frequency fluctuation (ALFF) maps were used as features in a mCCA + jICA model. Results of the mCCA + jICA model indicated three joint group‐discriminating components (GM‐CSF, WM‐ALFF, GM‐ALFF) and two modality‐unique group‐discriminating components (GM, WM). The joint component findings are highlighted by GM basal ganglia, somatosensory, parietal lobe, and thalamus abnormalities associated with ventricular CSF volume; WM occipital and frontal lobe abnormalities associated with temporal lobe function; and GM frontal, temporal, parietal, and occipital lobe abnormalities associated with caudate function. These results support and extend major findings throughout the literature using independent single modality analyses. The multimodal fusion of 7 T data in this study provides a more comprehensive illustration of the relationships between underlying neuronal abnormalities associated with schizophrenia than examination of imaging data independently.
Default mode network modifications in Fabry disease: A resting‐state fMRI study with structural correlations
Authors: Cocozza Sirio , Pontillo Giuseppe , Quarantelli Mario , Saccà Francesco , Riccio Eleonora , Costabile Teresa , Olivo Gaia , Brescia Morra Vincenzo , Pisani Antonio , Brunetti Arturo , Tedeschi Enrico ,   AFFINITY study group
Published: January 2018

AbstractAim of the study was to evaluate the presence of Default Mode Network (DMN) modifications in Fabry Disease (FD), and their possible correlations with structural alterations and neuropsychological scores. Thirty‐two FD patients with a genetically confirmed diagnosis of classical FD (12 males, mean age 43.3 ± 12.2) were enrolled, along with 35 healthy controls (HC) of comparable age and sex (14 males, mean age 42.1 ± 14.5). Resting‐State fMRI data were analyzed using a seed‐based approach, with six different seeds sampling the main hubs of the DMN. Structural modifications were assessed by means of Voxel‐Based Morphometry (VBM) and Tract‐Based Spatial Statistics analyses. Between‐group differences and correlations with neuropsychological variables were probed voxelwise over the whole brain. Possible correlations between FC modifications and global measures of microstructural alteration were also tested in FD patients with a partial correlation analysis. In the FD group, clusters of increased functional connectivity involving both supratentorial and infratentorial regions emerged, partially correlated to the widespread white matter (WM) damage found in these patients. No gray matter volume differences were found at VBM between the two groups. The connectivity between right inferior frontal gyrus and precuneus was significantly correlated with the Corsi block‐tapping test results (p = .0001). Widespread DMN changes are present in FD patients that correlate with WM alterations and cognitive performance. Our results confirm the current view of a cerebral involvement in FD patients not simply associated to major cerebrovascular events, but also related to significant and diffuse microstructural and functional changes.
A decision analytic model for prevention of hepatitis B virus infection in Sub‐Saharan Africa using birth‐dose vaccination
Authors: Anderson Sarah , Harper Lorie M. , Dionne‐Odom Jodie , Halle‐Ekane Gregory , Tita Alan T.N. 
Published: January 2018

AbstractObjectiveTo compare prenatal maternal hepatitis B virus (HBV) screening and infant vaccination strategies to inform policy on HBV prevention in Sub‐Saharan Africa.MethodsA decision analytic model was created using previously published data to assess the ability of three intervention strategies to prevent HBV infection by age 10 years. Strategy 1 comprised of universal vaccination with a pentavalent vaccine (HBV, diphtheria, tetanus, pertussis, and Haemophilus influenzae) at age 6 weeks. Strategy 2 comprised of universal HBV vaccine at birth plus pentavalent vaccine. Strategy 3 comprised of maternal prenatal HBV screening and targeted HBV vaccine at birth for all exposed infants plus pentavalent vaccine. The reference strategy provided neither maternal screening nor infant vaccination. Rates of HBV infection and costs were compared.ResultsThe reference strategy had an HBV infection rate of 2360 per 10 000 children. The HBV infection rate for strategy 1 was 813 per 10 000 children vaccinated (1547 cases prevented). Strategies 2 and 3 prevented an additional 384 cases and 362 cases, respectively. Inclusion of HBV vaccination at birth was the preferred approach at a willingness‐to‐pay threshold of US$150.ConclusionIncluding a birth‐dose HBV vaccine in the standard schedule was both cost‐effective and prevented additional infections.