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1,2-Dibromo-3-chloropropane


1,970 References Were Found:

Journal Article
Journal Article

Nanopatterning via Self-Assembly of a Lamellar-Forming Polystyrene-block-Poly(dimethylsiloxane) Diblock Copolymer on Topographical Substrates Fabricated by Nanoimprint Lithography

Authors: Borah, D; Cummins, C; Rasappa, S; Senthamaraikannan, R; Salaun, M; Zelsmann, M; Liontos, G; Ntetsikas, K; Avgeropoulos, A; Morris, MA (2018) 8. HERO ID: 4659280

[Less] The self-assembly of a lamellar-forming polystyrene-block-poly(dimethylsiloxane) (PS-b-PDMS) diblock . . . [More] The self-assembly of a lamellar-forming polystyrene-block-poly(dimethylsiloxane) (PS-b-PDMS) diblock copolymer (DBCP) was studied herein for surface nanopatterning. The DBCP was synthesized by sequential living anionic polymerization of styrene and hexamethylcyclotrisiloxane (D₃). The number average molecular weight (Mn), polydispersity index (Mw/Mn) and PS volume fraction (φps) of the DBCP were MnPS = 23.0 kg mol-1, MnPDMS = 15.0 kg mol-1, Mw/Mn = 1.06 and φps = 0.6. Thin films of the DBCP were cast and solvent annealed on topographically patterned polyhedral oligomeric silsesquioxane (POSS) substrates. The lamellae repeat distance or pitch (λL) and the width of the PDMS features (dL) are ~35 nm and ~17 nm, respectively, as determined by SEM. The chemistry of the POSS substrates was tuned, and the effects on the self-assembly of the DBCP noted. The PDMS nanopatterns were used as etching mask in order to transfer the DBCP pattern to underlying silicon substrate by a complex plasma etch process yielding sub-15 nm silicon features.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Assessment of Groundwater Susceptibility to Non-Point Source Contaminants Using Three-Dimensional Transient Indexes

Authors: Zhang, Y; Weissmann, GS; Fogg, GE; Lu, B; Sun, H; Zheng, C (2018) International Journal of Environmental Research and Public Health 15. HERO ID: 4821832

[Less] Groundwater susceptibility to non-point source contamination is typically quantified by stable indexes, . . . [More] Groundwater susceptibility to non-point source contamination is typically quantified by stable indexes, while groundwater quality evolution (or deterioration globally) can be a long-term process that may last for decades and exhibit strong temporal variations. This study proposes a three-dimensional (3-d), transient index map built upon physical models to characterize the complete temporal evolution of deep aquifer susceptibility. For illustration purposes, the previous travel time probability density (BTTPD) approach is extended to assess the 3-d deep groundwater susceptibility to non-point source contamination within a sequence stratigraphic framework observed in the Kings River fluvial fan (KRFF) aquifer. The BTTPD, which represents complete age distributions underlying a single groundwater sample in a regional-scale aquifer, is used as a quantitative, transient measure of aquifer susceptibility. The resultant 3-d imaging of susceptibility using the simulated BTTPDs in KRFF reveals the strong influence of regional-scale heterogeneity on susceptibility. The regional-scale incised-valley fill deposits increase the susceptibility of aquifers by enhancing rapid downward solute movement and displaying relatively narrow and young age distributions. In contrast, the regional-scale sequence-boundary paleosols within the open-fan deposits "protect" deep aquifers by slowing downward solute movement and displaying a relatively broad and old age distribution. Further comparison of the simulated susceptibility index maps to known contaminant distributions shows that these maps are generally consistent with the high concentration and quick evolution of 1,2-dibromo-3-chloropropane (DBCP) in groundwater around the incised-valley fill since the 1970s'. This application demonstrates that the BTTPDs can be used as quantitative and transient measures of deep aquifer susceptibility to non-point source contamination.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Associations between retinal arteriolar and venular calibre with the prevalence of impaired fasting glucose and diabetes mellitus: A cross-sectional study

Authors: Phan, K; Mitchell, P; Liew, G; Plant, AJ; Wang, SB; Thiagalingam, A; Burlutsky, G; Gopinath, B (2018) HERO ID: 4822683

[Less] BACKGROUND: This study aims to explore retinal vessel calibre in individuals at risk . . . [More] BACKGROUND: This study aims to explore retinal vessel calibre in individuals at risk of coronary artery disease (CAD), diagnosed with impaired fasting glucose (IFG) or diabetes mellitus (DM), and whether indices of CAD extent and severity modifies these associations with DM.

METHODS: A cross-sectional study was undertaken of 1680 patients presenting to Westmead Hospital (Sydney, Australia) for evaluation of potential CAD. Baseline digital retinal photographs, cardiovascular risk factor measurements, fasting blood tests and self-reported diabetes by patient questionnaire was recorded. Extent and severity of CAD was assessed using Extent and Gensini scores from angiography findings, respectively. Multivariate analysis including age and hypertension was undertaken to assess the association between retinal vessel calibre and IFG or DM.

RESULTS: A total of 748 patients were included; 96 (12.8%) and 189 (25.3%), respectively, had IFG or DM (together termed 'hyperglycaemia'). No consistent association between hyperglycaemia and retinal arteriolar calibre was apparent. Wider retinal venular calibre (second and third tertile) carried a significantly higher odds of DM in men only (multivariable-adjusted OR 2.447, p = 0.005; and OR 2.76, p = 0.002; respectively). No equivalent association was apparent in women. This association was marginally significant (p = 0.08) in patients with CAD Extent scores below the median (i.e. less diffuse CAD). Retinal vessel calibre was not associated with impaired fasting glucose.

CONCLUSIONS: This study reports a significant association between retinal venular widening and diabetes mellitus in men. This association was marginally stronger among participants with less diffuse CAD.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Exposure to hazardous air pollutants and risk of incident breast cancer in the nurses' health study II

Authors: Hart, JE; Bertrand, KA; Dupre, N; James, P; Vieira, VM; Vopham, T; Mittleman, MR; Tamimi, RM; Laden, F (2018) Environmental Health: A Global Access Science Source 17:28. HERO ID: 4821835

[Less] BACKGROUND: Findings from a recent prospective cohort study in California suggested . . . [More] BACKGROUND: Findings from a recent prospective cohort study in California suggested increased risk of breast cancer associated with higher exposure to certain carcinogenic and estrogen-disrupting hazardous air pollutants (HAPs). However, to date, no nationwide studies have evaluated these possible associations. Our objective was to examine the impacts of mammary carcinogen and estrogen disrupting HAPs on risk of invasive breast cancer in a nationwide cohort.

METHODS: We assigned HAPs from the US Environmental Protection Agency's 2002 National Air Toxics Assessment to 109,239 members of the nationwide, prospective Nurses' Health Study II (NHSII). Risk of overall invasive, estrogen receptor (ER)-positive (ER+), and ER-negative (ER-) breast cancer with increasing quartiles of exposure were assessed in time-varying multivariable proportional hazards models, adjusted for traditional breast cancer risk factors.

RESULTS: A total of 3321 invasive cases occurred (2160 ER+, 558 ER-) during follow-up 1989-2011. Overall, there was no consistent pattern of elevated risk of the HAPs with risk of breast cancer. Suggestive elevations were only seen with increasing 1,2-dibromo-3-chloropropane exposures (multivariable adjusted HR of overall breast cancer = 1.12, 95% CI: 0.98-1.29; ER+ breast cancer HR = 1.09; 95% CI: 0.92, 1.30; ER- breast cancer HR = 1.14; 95% CI: 0.81, 1.61; each in the top exposure quartile compared to the lowest).

CONCLUSIONS: Exposures to HAPs during adulthood were not consistently associated with an increased risk of overall or estrogen-receptor subtypes of invasive breast cancer in this nationwide cohort of women.

Book/Book Chapter
Book/ Chapter

BC Tree-based Proxy Graphs for Visualization of Big Graphs

Authors: Hong, SHee; Quan Nguyen; Meidiana, A; Li, J; Eades, P; IEEE (2018) HERO ID: 4822134

[Less] Recent work for visualizing big graphs uses a proxy graph approach: the original graph is replaced by . . . [More] Recent work for visualizing big graphs uses a proxy graph approach: the original graph is replaced by a proxy graph, which is much smaller than the original graph. The challenge for the proxy graph approach is to ensure that the proxy graph is a good representation of the original graph. However, previous work to compute proxy graphs using graph sampling techniques often fails to preserve connectivity and important global skeletal structure in the original graph.

This paper introduces two new families of proxy graph methods BCP-W and BCP-E, tightly integrating graph sampling methods with the BC (Block Cut-vertex) tree, which represents the decomposition of a graph into biconnected components. Experimental results using graph sampling quality metrics show that our new BC tree-based proxy graph methods produce significantly better results than existing sampling-based proxy graph methods: 25% improvement by BCP-W and 15% by BCP-E on average.

We also present DBCP, a BC tree-based proxy graph method for distributed environment. Experiments on the Amazon Cloud EC2 demonstrate that DBCP is scalable for big graph data sets; runtime speed-up of 77% for distributed 5-server on average.

Visual comparison using a graph layout method and the proxy quality metrics confirm that our new BC tree-based proxy graph methods are significantly better than existing sampling-based proxy graph method. Our main results lead to guidelines for computing sampling-based proxy graphs for visualization of big graphs.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Modeling Subsurface Fate of S-Metolachlor and Metolachlor Ethane Sulfonic Acid in the Westliches Leibnitzer Feld Aquifer

Authors: Kupfersberger, H; Klammler, G; Schuhmann, A; Brueckner, L; Kah, M (2018) HERO ID: 4822173

[Less] Pesticides and their metabolites have been increasingly detected in groundwater bodies in southeastern . . . [More] Pesticides and their metabolites have been increasingly detected in groundwater bodies in southeastern Austria in recent years. The main objective of this study was to model the fate of the herbicide S-metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-[(1S)-2-methoxy-l-methylethyllacetamide; SMET) and the main metabolite metolachlor ethane sulfonic acid (MESA) at the Westliches Leibnitzer Feld (WLF) aquifer. For this purpose, a modeling approach based on coupling the one-dimensional vadose zone model PEARL and the two-dimensional groundwater flow and solute transport model FEFLOW was developed. To calibrate the one-dimensional pesticide fate model, we used leachate concentrations of SMET and MESA from lysimeter experiments. Additionally, samples of representative soil types in the WLF aquifer were analyzed to infer SMET- and MESA-specific fate parameters (e.g., half-life DT50, Freundlich sorption coefficient K-foc), which were used for the PEARL model. The results show that using SMET fate parameters derived from the lysimeter data considerably improved the fit of the simulation results with the field observations compared with the application of standard laboratory-derived fate parameters accounting for soil type differences. Although locally an overestimation of the monitoring data prevailed, the description of the subsurface fate of pesticides will improve the interpretation of concentration data and the design of mitigation measures.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Characterization, antioxidant and hypoglycemic activities of degraded polysaccharides from blackcurrant (Ribes nigrum L.) fruits

Authors: Xu, Y; Niu, X; Liu, N; Gao, Y; Wang, L; Xu, G; Li, X; Yang, Y (2018) Food Chemistry 243:26-35. HERO ID: 4324096

[Less] In this study, the degradation of polysaccharides from blackcurrant (BCP) was investigated. Two low-molecular-weight . . . [More] In this study, the degradation of polysaccharides from blackcurrant (BCP) was investigated. Two low-molecular-weight polysaccharides (DBCP-1, DBCP-2) were obtained using Fe2+ with different concentrations of H2O2 solution. IR spectra showed DBCPs had obvious characteristic peaks of polysaccharides. GC analysis confirmed DBCPs were composed of the same monosaccharide units as BCP but with different molar ratios. NMR analysis indicated DBCPs and BCP had similar glycosidic linkage patterns. The surface area of fragmented structure in DBCPs was reduced compared to BCP, and they had no triple helix structure. The results of bioactivity assays indicated that DBCPs exhibited higher antioxidant, α-amylase and α-glucosidase inhibitory activities than BCP, and the degraded polysaccharides with the lower molecular weight possessed higher bioactivities. These results suggested that Fe2+-H2O2 degradation did not change the main structure of polysaccharide and the degree of degradation could play a key role in the bioactivities of the polysaccharides.

Journal Article
Journal Article

Doubly Balanced Connected Graph Partitioning

Authors: Soltan, S; Yannakakis, M; Zussman, Gil; ACM (2017) HERO ID: 4822548

[Less] We introduce and study the Doubly Balanced Connected graph Partitioning (DBCP) problem: Let G=(V, E) . . . [More] We introduce and study the Doubly Balanced Connected graph Partitioning (DBCP) problem: Let G=(V, E) be a connected graph with a weight (supply/demand) function p:V ->{-1, +1} satisfying p(V)=Sigma(j is an element of v) p(j)=0. The objective is to partition G into (V-1, V-2) such that G[V-1] and G[V-2] are connected, vertical bar P(V-1)vertical bar, vertical bar P(V-2)vertical bar <= c(p), and max{vertical bar V-1 vertical bar/vertical bar V-2 vertical bar, vertical bar V-2 vertical bar/vertical bar V-1 vertical bar}<= c(s), for some constants c(p) and c(s). When G is 2-connected, we show that a solution with c(p)=1 and c(s)=3 always exists and can be found in polynomial time. Moreover, when G is 3-connected, we show that there is always a 'perfect' solution (a partition with p(V-1)=p(V-2)=0 and vertical bar V-1 vertical bar=vertical bar V-2 vertical bar, if vertical bar V vertical bar equivalent to 0(mod 4)), and it can be found in polynomial time. Our techniques can be extended, with similar results, to the case in which the weights are arbitrary (not necessarily +/- 1), and to the case that p(V)not equal 0 and the excess supply/demand should be split evenly. They also apply to the problem of partitioning a graph with two types of nodes into two large connected subgraphs that preserve approximately the proportion of the two types.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Density cluster based approach for controller placement problem in large-scale software defined networkings

Authors: Liao, J; Sun, H; Wang, J; Qi, Qi; Li, Kai; Li, T (2017) HERO ID: 4822716

[Less] Software Defined Networking (SDN) decouples control and data planes. The separation arises a problem . . . [More] Software Defined Networking (SDN) decouples control and data planes. The separation arises a problem known as the controller placement, i.e., how many and where controllers should be deployed. Currently, most works defined this problem as the multi-objective combinatorial optimization problem and used heuristic algorithms to search the optimal solution. However, these heuristic algorithms have the drawback of being easily trapped in local optimal solutions and consuming high time. In this paper, we propose an approach named as Density Based Controller Placement (DBCP), which uses a density-based switch clustering algorithm to split the network into several sub-networks. As switches are tightly connected within the same sub-network and less connected from the switches in other sub-networks, we deploy one controller in each sub-network. In DBCP, the size of each sub-network can be decided by the capacity of the controller deployed. Moreover, the optimal number of controllers is obtained according to the density-based clustering. We evaluate DBCP's performance on a set of 262 publicly available network topologies. The experimental results show that DBCP provides better performance than the state-of-the-art approaches in terms of time consumption, propagation latency, and fault tolerance. (C) 2016 Elsevier B.V. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Enantioselective determination of (R)-zopiclone and (S)-zopiclone (eszopiclone) in human hair by micropulverized extraction and chiral liquid chromatography/high resolution mass spectrometry

Authors: Miyaguchi, H; Kuwayama, K (2017) HERO ID: 4822780

[Less] Zopiclone and its (S)-enantiomer (eszopiclone) are commonly prescribed for insomnia. Despite the high . . . [More] Zopiclone and its (S)-enantiomer (eszopiclone) are commonly prescribed for insomnia. Despite the high demand for enantioselective differentiation, the chiral analysis of zopiclone in hair has not been reported. In this study, a method for the enantioselective quantification of zopiclone in human hair was developed. The extraction medium and duration were optimized using real eszopiclone-positive hair samples. Specifically, micropulverized extraction with 3.0M ammonium phosphate buffer (pH 8.4) involving salting-out assisted liquid-liquid extraction with acetonitrile was utilized to minimize the degradation of zopiclone and for rapid and facile operation. On the other hand, recovery of the conventional solid-liquid extraction involved overnight soaking in 3.0M ammonium phosphate buffer (pH 8.4) was only 0.58±0.12% of the maximum recovery achieved by the present method due to the decomposition in the phosphate buffer. An excellent chiral separation (Rs=5.0) was achieved using a chiral stationary phase comprising cellulose tris(3,5-dichlorophenylcarbamate) and a volatile mobile phase of 10mM ammonium carbonate (pH 8.0)-acetonitrile (25:75, v/v). Detection was carried out using liquid chromatography/high resolution mass spectrometry (LC/HRMS) with electrospray ionization. A Q Exactive mass spectrometer equipped with a quadrupole-Orbitrap analyzer was used for detection. The concentration of 0.50pg/mg was defined as the lowest limit of quantification using 5mg of hair sample. Using the developed approach, the concentration of eszopiclone in hair after a single 2-mg dose was found to be 441pg/mg, which was higher than all the reported values regarding a single administration of zopiclone. After daily administration of racemic zopiclone (3.75mg/day), the concentrations of (R)-enantiomer and (S)-enantiomer in the black hair were 5.30-8.31ng/mg and 7.96-12.8ng/mg, respectively, and the concentration of the (S)-enantiomer was always higher than that of the (R)-enantiomer due to the enantioselective difference in the pharmacokinetics.