bluuebunny/crossref_metadata_2025_split huggingface dataset:
How subcellular partitioning can help to understand heavy metal accumulation and elimination kinetics in snails
Authors: Gimbert Frédéric , Vijver Martina G , Coeurdassier Michaël , Scheifler Renaud , Peijnenburg Willie J.G.M , Badot Pierre-Marie , de Vaufleury Annette 
Published: May 2008

Abstract
To understand bioaccumulation kinetics of metals within biota inhabiting industrially contaminated soils, toxicokinetic dynamics and subcellular fractionation were carried out with the terrestrial snail Helix aspersa in a long-term (six-month) laboratory experiment. Accumulation and elimination kinetics were determined for Cd, Pb, and Zn in both viscera and foot of snails and were described accurately by one-compartment models. The subcellular fractions were obtained by sequential centrifugations and were analyzed by isolating metal-rich granules, tissue fragments, and cytosolic fractions. Different fractions showed metal-specific binding capacities that might be useful in identifying the biological significance of accumulated metal levels in snails. Cadmium was retrieved mainly from the cytosolic fraction, where it was stored in the long term and not excreted, thus explaining the linear accumulation patterns. Most of the accumulated Pb was found in the granular fraction, and snails appeared able to excrete these concretions, leading to achievement of a steady state in internal Pb body burdens. Significant levels of Pb, however, were retrieved at the end of the depuration phase and retained in the cell debris fraction. Zinc showed affinities for both cytosolic and granular fractions, leading to intermediate uptake and excretion patterns. The dynamics of the different sequestration forms at the subcellular level support the observed kinetics of metal body burdens and, in association with the determination of uptake fluxes, allow precise assessment of metal accumulation in snails.
Abiotic reduction of nitroaromatic contaminants by iron(II) complexes with organothiol ligands
Authors: Naka Daisuke , Kim Dongwook , Carbonaro Richard F , Strathmann Timothy J 
Published: May 2008

Abstract
Complexation of FeII by dissolved and surface-bound ligands can significantly modify the metal's redox reactivity, and recent work reveals that FeII complexes with selected classes of organic ligands are potent reductants that may contribute to the natural attenuation of subsurface contaminants. In the present study, we investigated the reactivity of FeII–organothiol ligand complexes with nitroaromatic contaminants (NACs; ArNO2). Experimental results show that NACs are unreactive in Fe2+-only and ligand-only solutions but are reduced to the corresponding aniline compounds (ArNH2) in solutions containing both FeII and a number of organothiol ligands. Observed reaction rates are highly dependent on the structure of the FeII-complexing ligand, solution composition, FeII speciation, and NAC structure. For two model ligands, cysteine and thioglycolic acid, observed pseudo–first order rate constants for 4-chloronitrobenzene reduction (kobs; 1/s) are linearly correlated with the concentration of the respective 1:2 FeII–organothiol complexes (FeL22−), and kobs measurements are accurately predicted by kobs = kFeL22-[FeL22−], where kFeL22- = 1.70 (±0.59) 1/M/s and 26.0 (±4.8) 1/M/s for cysteine and thioglycolic acid, respectively. The high reactivity of these FeII complexes is attributed to a lowering of the standard one-electron reduction potential of the FeIII/FeII redox couple on complexation by organothiol ligands. The relative reactivity of a series of substituted NACs with individual FeII complexes can be described by linear free-energy relationships with the apparent one-electron reduction potentials of the NACs. Tests also show that organothiol ligands can further promote NAC reduction indirectly by re-reducing the FeIII that forms when FeII complexes are oxidized by reactions with the NACs.
Tenax® extraction as a tool to evaluate the availability of polybrominated diphenyl ethers, ddt, and ddt metabolites in sediments
Authors: de la Cal Agustina , Eljarrat Ethel , Grotenhuis Tim , Barcelo Damià 
Published: May 2008

AbstractSolid-phase extraction with Tenax® is one of the most used methods for determining the fraction of a pollutant that desorbs rapidly from sediment and thus is available for living beings. In the present study, this technique has been applied to sediment contaminated in the laboratory with polybrominated diphenyl ethers (PBDEs) and dichlorodiphenyltrichloroethane, dichlorodifenyldichloroethylene, and dichlorodifenyldichloroethane (generically, DDXs). The amount of chemical retained in sediment during the time of the experiment fit well with a three-phase exponential desorption model. The ratios between the rapidly desorbing fraction and the fraction desorbed during a fixed time (6 or 24 h) were calculated. The fraction desorbed in 6 h was lower than the rapidly desorbing fraction for most of PBDEs, whereas the fraction desorbed in 24 h exceeded the rapidly desorbing fraction for both groups of compounds. However, variability of these data suggests, when possible, a long time measure of desorption in order to achieve a more accurate estimation. Both the extent and the velocity of desorption were inversely related with the bromination degree and, consistently, with hydrophobicity and molecular size. In this way, low brominated PBDEs and DDXs showed a high availability relative to high brominated PBDEs.
Adsorption of hydrophobic organic compounds onto a hydrophobic carbonaceous geosorbent in the presence of surfactants
Authors: Wang Peng , Keller Arturo A 
Published: May 2008

Abstract
The adsorption of hydrophobic organic compounds (HOCs; atrazine and diuron) onto lampblack was studied in the presence of nonionic, cationic, and anionic surfactants (Triton® X-100), benzalkonium chloride [BC], and linear alkylbenzene sulfonate [LAS]) to determine the effect of the surfactant on HOC adsorption onto a hydrophobic carbonaceous geosorbent. Linear alkylbenzene sulfonate showed an adsorption capacity higher than that of BC but similar to that of Triton X-100, implying the charge property of a surfactant is not a useful indicator for predicting the surfactant's adsorption onto a hydrophobic medium. The results also indicated that the octanol-water partition coefficient (Kow) of a surfactant is not a good predictor of that surfactant's sorption onto a hydrophobic medium. Under subsaturation adsorption conditions (i.e., before sorption saturation is reached), surfactant adsorption reduced HOC adsorption to a significant extent, with the reduction in HOC adsorption increasing monotonically with the amount of surfactant adsorbed. Among the three surfactants, Triton X-100 was the most effective in reducing HOC adsorption, whereas BC and LAS showed similar effectiveness in this regard. Under the same amount of the surfactant sorbed, the reduction in atrazine adsorption was consistently greater than that for diuron because of atrazine's lower hydrophobicity. No significant difference was observed in the amount of the HOC adsorbed under different adsorption sequences. Our results showed that the presence of surfactant can significantly decrease HOC adsorption onto hydrophobic environmental media and, thus, is important in predicting HOC fate and transport in the environment.
Understanding road surface pollutant wash-off and underlying physical processes using simulated rainfall
Authors: Egodawatta Prasanna , Goonetilleke Ashantha 
Published: May 2008

Pollutant wash-off is one of the key pollutant processes that detailed knowledge is required in order to develop successful treatment design strategies for urban stormwater. Unfortunately, current knowledge relating to pollutant wash-off is limited. This paper presents the outcomes of a detailed investigation into pollutant wash-off on residential road surfaces. The investigations consisted of research methodologies formulated to overcome the physical constraints due to the heterogeneity of urban paved surfaces and the dependency on naturally occurring rainfall. This entailed the use of small road surface plots and artificially simulated rainfall. Road surfaces were selected due to its critical importance as an urban stormwater pollutant source.
The study results showed that the influence of initially available pollutants on the wash-off process was limited. Furthermore, pollutant wash-off from road surfaces can be replicated using an exponential equation. However, the typical version of the exponential wash-off equation needs to be modified by introducing a non dimensional factor referred to as ‘capacity factor' CF. Three rainfall intensity ranges were identified where the variation of CF can be defined. Furthermore, it was found that particulate density rather than size is the critical parameter that influences the process of pollutant wash-off.
Mortality in surgical units and postoperative care
Authors: Piechota Mariusz , Piechota Anna , Rysz Jacek 
Published: May 2008

Abstract
In the year 2005, 10 public health care institutions in Lodz contained general surgery units. The lowest mortality rate, 0,35%, was recorded in the surgical unit of University Teaching Hospital No. 5 (UH No. 5). We performed a retrospective comparative analysis of mortality in this hospital and in the two remaining university teaching hospitals, University Teaching Hospital No. 1 (UH No. 1) and University Teaching Hospital No. 2 (UH No. 2). The study was comprised of data from 18911 patients treated in these units from 01.01.2003 to 31.12.2005. The statistical data were collected by the Provincial Centre of Public Health in Lodz. The structure of the analysed units and the structure of the selected groups of diagnoses were compared. A relative structure similarity index was used to compare the structure of hospitalised patients in the analysed units, in an attempt to discover the reasons for significantly lower mortality among patients hospitalised in surgical unit of UH No. 5. A detailed analysis of the selected diagnoses and of mortality indicated that early postoperative intensive care in severely ill patients and immediate admission to the ICU, when indicated, significantly decrease mortality.
User-adaptive Reminders for Home-based Medical Tasks
Authors: Intille S. S. , Larson K. , Kaushik P. 
Published: May 2008

Summary

Objectives:
We present a prototype adaptive reminder system for home-based medical tasks. The system consists of a mobile device for reminder presentation and ambient sensors to determine opportune moments for reminder delivery. Our objective was to study interaction with the prototype under naturalistic living conditions and gain insight into factors affecting the longterm acceptability of context-sensitive reminder systems for the home setting.

Methods:
A volunteer participant used the prototype in a residential research facility while adhering to a regimen of simulated medical tasks for ten days. Some reminders were scheduled at fixed times during the day and some were automatically time-shifted based on sensor data. We made a complete video and sensor record of the stay. Finally, the participant commented about his experiences with the system in a debriefing interview.

Results:
Based on this case study, including direct observation of individual alert-action sequences, we make four recommendations for designers of context-sensitive adaptive reminder systems. Captured metrics suggest that adaptive reminders led to faster reaction times and were perceived by the participant as being more useful.

Conclusions:
The evaluation of context-sensitive systems that overlap into domestic lives is challenging. We believe that the ideal experiment is to deploy such systems in real homes and assess performance longitudinally. This case study in an instrumented live-in facility is a step toward that long-term goal.
Mixed‐longitudinal growth of breastfeeding children in Moroto District, Uganda (Karamoja subregion). A loss of biological resiliency?
Authors: Gray Sandra , Akol Hellen A. , Sundal Mary 
Published: May 2008

AbstractThis study examines the pattern of growth, underlying growth velocity and nutritional status in a sample of thirty breastfeeding Karimojong children, aged from birth to three years. A mixed‐longitudinal structure was adopted for the study, which was carried out between August and December, 2004, in two communities in Moroto District, Uganda. Monthly anthropometric and health examinations were administered to mothers and children during this interval. Children in the study were small at birth but grew relatively rapidly for their first six months. Thereafter they experienced falling off of growth in weight, length, and head circumference. Loss of growth velocity and deterioration in nutritional status after six months was a result of physiologic stress arising from high parasite loads, introduction of inappropriate weaning foods, and psychosocial stress associated with patterns of maternal behavior. Environmental and maternal effects on child growth were exacerbated by widespread armed violence and related subsistence change in these communities. Growth of these children reflects loss of growth plasticity resulting from worsening environmental and social conditions in Moroto in 2004. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Analyzing the genetic structure of the Tepehua in relation to other neighbouring Mesoamerican populations. A study based on allele frequencies of STR markers
Authors: González‐Martín Antonio , Gorostiza Amaya , Rangel‐Villalobos Héctor , Acunha Víctor , Barrot Carme , Sánchez Cristina , Ortega Monserrat , Gené Manel , Calderón Rosario 
Published: May 2008

AbstractWe report data on the genetic variation of the Tepehua population based on 15 autosomal microsatellites. The Tepehua, whose language belongs to the Totonac family, are settled throughout the Sierra Madre Oriental in Mexico and constitute a group in demographic decline. The results suggest that the Tepehua population remained isolated throughout a large part of its history. Phylogenetic analyses performed with other indigenous and admixed populations of Mesoamerica allow us to address their biological history. The results suggest a genetic affinity between the Tepehua and the Huastecos due to their previous shared history, and a certain degree of differentiation from the Otomões groups and the Choles (who are of Mayan origin). A clear genetic differentiation is also apparent between native and admixed populations within the greater region of Mesoamerica. It is currently accepted that the genetic composition of the American populations fits a trihybrid model of admixture. The genetic structure based on comparison of 34 populations throughout the continent (9 indigenous and 23 admixed) using hierarchical cluster analysis with an explained variance of 61.17% suggests the existence of four large groups distinguished according to the degree of admixture between Amerindians, Europeans, and Africans. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Immunoglobulin allotypes in Southwest Asia: Populations at the Crossroads
Authors: Schanfield Moses S. , Ferrell Robert E. , Hossaini Ali A. , Gerald Sandler S. , Stevenson Joan C. 
Published: May 2008

AbstractSouthwest Asia has a long history of contact with Central Asian and with Sub‐Saharan African populations. Is the genetic structure of these populations reflective of these historical facts? To study this, data was generated on the immunoglobulin heavy chain (GM) and light chain (KM) allotypes from seven Arab and three non‐Arab populations in SW Asia to examine the relationship of these populations to SE European, NW Indian, Sub‐Saharan African, and Central Asian populations. Like mtDNA and Y chromosome markers, the GM haplotypes are largely continent specific making them an excellent tool for the detection of gene flow whereas the KM markers are less informative. Six of the nine GM haplotypes detected in SW Asians are Indo‐European, Sub‐Saharan African, or East Asian specific. The allotype results indicate variable but significantly higher Sub‐Saharan African gene flow in Arab populations (average 26.9%; 15.0–61.6%) vs. the non‐Arab populations (average 7.3%; 9.0–13.4%), but higher levels of Central Asian gene flow in the non‐Arab populations (average 28.8%; 10.5–48.8%) vs. the Arab populations (average 9.0%; 0.0–26.4%). Principal components analysis and hierarchical cluster analysis based on the immunoglobulin allotypes are consistent with the historical population contacts of this part of the world and reflect the power of the GM haplotypes in dissecting population relationships. However, the KM*1 frequencies were only correlated with the degree of African gene flow (Pearson r = 0.69, P = 0.026) in SW Asian populations. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Mitochondrial DNA variation and substructure among the tribal populations of Andhra Pradesh, India
Authors: Mittal Bharti , Tripathy Vikal , Aruna M. , Reddy A. G. , Thanseem I. , Thangaraj K. , Singh Lalji , Reddy B. M. 
Published: May 2008

AbstractWe analyzed mtDNA HVR‐I variation among six tribal populations—Andh, Pardan, Gond, Naikpod, Kolam and Chenchu—from Andhra Pradesh. These tribes belong to the Dravidian and Indo‐European linguistic group. Except for Chenchu, the rest of the tribal samples were collected from two or more than two locations. The analysis of molecular variance (AMOVA) of the sequences yields a significant FST value (0.045), suggesting a fair degree of genetic differentiation among these tribes. When the tribal samples collected from different locations were considered as subpopulations in AMOVA, it is found that the variation among the subunits within the tribal groups is smaller than among the tribes. However, when Chenchu is removed from the analysis, the magnitude of within and between groups diversity becomes similar. In the multidimensional scaling plot based on FST distances the Chenchu is found to be the extreme outlier. Exclusion of Chenchu from AMOVA analysis and multidimensional scaling plot does not result in any specific pattern of population clustering. Mismatch distribution suggest that Chenchu might have undergone a bottleneck effect and does not show evidence of past demographic expansion as shown by the other five tribal groups. A comparison of AP tribes with some other caste and tribal populations of India suggests common maternal genetic heritage. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Open‐Framework Structures of Transition‐Metal Compounds
Authors: Natarajan Srinivasan , Mandal Sukhendu 
Published: May 2008

AbstractInorganic framework solids are no longer limited to just the silicates and phosphates. Recent research has revealed that carboxylates, arsenates, sulfates, selenates, selenites, germanates, phosphites can also form such structures. One of the emerging areas combines the rich coordination chemistry of the central metal ions of many of these structures with the flexibility and functionality of the organic linkers to give rise to organic–inorganic hybrid compounds. The compounds of the transition‐metals appear to provide many variations arising from their coordination preferences, ligand geometry, and the valence state. In addition, the combination of the magnetic nature of the transition metal center with the channel structure of open frameworks suggests interesting potential applications. In this Review the synthesis, structures and properties of the various transition‐metal open‐framework compounds are discussed.
Thermal degradation behavior of poly(vinyl chloride) in presence of poly(N‐acryloyl‐N′‐cyanoacetohydrazide)
Authors: Mohamed Nadia A. , Farag Zeinab R. , Sabaa Magdy W. 
Published: May 2008

AbstractThe thermal degradation behavior of poly (vinyl chloride), PVC, in presence of poly(N‐acryloyl‐N′‐cyanoacetohydrazide), PACAH, has been studied using continuous potentiometric determination of the evolved HCl gas from the degradation process from one hand and by measuring the extent of discoloration of the degraded samples from the other. The efficiency of blending PACAH with dibasic lead carbonate, DBLC, conventional thermal stabilizer has also been investigated. A probable radical mechanism for the effect of PACAH on the thermal stabilization of PVC has been proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of novel Schiff‐base polyamides from copper/benzil bisthiosemicarbazone complexes
Authors: Ghaemy Mousa , Mighani Hossein , Behmadi Hossein 
Published: May 2008

AbstractA new copper‐containing Schiff‐base diamine, benzil bis(thiosemicarbazonato)copper(II) (CuLH4), was synthesized in two steps from benzil bisthiosemicarbazone (LH6). The ligand LH6 and the complex CuLH4 were characterized with Fourier transform infrared spectroscopy, 1H‐NMR, and elemental analysis. CuLH4 was used to prepare novel polyamides. The low‐temperature solution polycondensation of the complex CuLH4 with various aromatic and aliphatic diacid chlorides afforded copper‐containing Schiff‐base polyamides with inherent viscosities of 0.25–0.36 dL/g in N,N‐dimethylformamide (DMF) and 0.75 dL/g in H2SO4 at 25°C. The polyamides were generally soluble in a wide range of solvents, such as DMF, N,N‐dimethylacetamide, tetrahydrofuran, dimethyl sulfoxide, ethyl acetate, tetrachloroethane, hexamethylene phosphoramide, N‐methylpyrrolidone, and pyridine. Thermal analysis showed that these polyamides were practically amorphous, decomposed above 270°C, and exhibited 50% weight loss at and above 400°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Electrochemical preparation of poly(N‐acetylaniline)/poly‐(4‐styrenesulfonic acid‐co‐maleic acid) composite film towards ascorbic acid sensing
Authors: Zhou Baineng , Wu Shouguo 
Published: May 2008

AbstractPoly(N‐acetylaniline)/poly(4‐styrenesulfonic acid‐co‐maleic acid) (PNAANI/PSSMA) composite film was prepared by cyclic voltammetry (CV), and was characterized by FTIR and X‐ray photoelectron spectrum (XPS). The electroactivity of the composite film was high in neutral and basic solutions, and it had been used for amperometric determination of ascorbic acid (AA). Compared with pure PNAANI film, the catalytic activity of the composite film was much better. AA was detected amperometrically in sodium citrate buffer at a potential of 0.3 V (versus SCE). The response current was proportional to the concentration of ascorbic acid in the range of 4.7 × 10−6 to 5.0 × 10−5M and 5.0 × 10−5 to 2.5 × 10−3M, respectively, with the detection limit of 1.9 × 10−6 mol L−1 at a signal to noise ratio 3. In addition, the stability and reusability of the composite film were performed well, and it was satisfying to be used for determination of AA in real fruit juice samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008