60 research outputs found
Isolation of insecticidal components in <i>Inula salsoloides</i> Ostenf. and characterisation of their activities
<p>The ethanol extract from <i>Inula salsoloides</i> (Turcz.) Ostenf was found to cause high mortality against <i>Plutella xylostella</i> L. (Lepidoptera: Plutellidae). The active components were isolated and identified. Two compounds were obtained and identified to be inulasalsolin and taraxasterol. Both compounds showed anti-feedant effects against third instar larvae of <i>P. xylostella</i> with AFC<sub>50</sub> of 0.030 and 0.053Â mg/mL and insecticidal activities with LC<sub>50</sub> of 0.19 and 0.49Â mg/mL, respectively. The two compounds also exhibited high toxicity to cabbage aphid, <i>Brevicoryne brassicae</i> L. (Hemiptera: Aphididae) with LC<sub>50</sub> values of 0.021 and 0.098Â mg/mL. This is the first report on the study of insecticidal components of <i>I. salsoloides</i> and their activity against insects.</p
A Divergence-free Multi-scale Synthetic Eddy Method for LES Simulation of ABL
This paper was reviewed and accepted by the APCWE-IX Programme Committee for Presentation at the 9th Asia-Pacific Conference on Wind Engineering, University of Auckland, Auckland, New Zealand, held from 3-7 December 2017
A Wind Load and Structural Parameters Estimation Approach for Building Structures
This paper was reviewed and accepted by the APCWE-IX Programme Committee for Presentation at the 9th Asia-Pacific Conference on Wind Engineering, University of Auckland, Auckland, New Zealand, held from 3-7 December 2017
Environmental Polychlorinated Biphenyl Exposure and Breast Cancer Risk: A Meta-Analysis of Observational Studies
<div><p>Background</p><p>Association between polychlorinated biphenyl (PCB) exposure and breast cancer risk has been widely studied, but the results remain controversial. We performed a meta-analysis to evaluate the evidences from observational studies on PCB exposure and breast cancer risk.</p><p>Methods</p><p>Relevant studies with data on internal PCB dose were identified from PubMed, EMBASE, CBM and CNKI databases through November 2014. Multivariable-adjusted odds ratio (OR) with 95% confidence intervals (CIs) were applied to assess the association between PCB exposure and breast cancer risk. Heterogeneity test, sensitivity analysis, subgroup analysis and publication bias test were also performed. To further explore the association between specific groups of PCB congeners and breast cancer, we examined the PCB congeners classified, according to their structural, biological and pharmacokinetics properties, as group I (potentially estrogenic), group II (potentially anti-estrogenic and immunotoxic, dioxin-like), and group III (phenobarbital, CYP1A and CYP2B inducers, biologically persistent).</p><p>Results</p><p>Of 660 studies screened, 25 studies which met criteria were selected, involving a total of 12866 participants (6088 cases and 6778 controls) from eight countries. The results showed that the risk of breast cancer was associated with group II (OR = 1.23, 95% CI: 1.08–1.40) and group III (OR = 1.25, 95% CI: 1.09–1.43) PCBs, but not with group I (OR = 1.10, 95%CI: 0.97–1.24) PCBs or total PCB exposure (OR = 1.09, 95%CI: 0.97–1.22).</p><p>Conclusions</p><p>Our meta-analysis based on the selected studies found group II and group III PCB exposure might contribute to the risk of breast cancer. More studies in developing countries with higher PCB levels are needed, as well as studies to explore the relationships between mixtures of organochlorine compounds and breast cancer risk.</p></div
Forest plot describing the association between phenobarbital, CYP1A and CYP2B inducers, biologically persistent PCBs (Group III) exposure and breast cancer risk.
<p>Apart from the overall analysis, the subgroup analyses on prospective (upper panels) and retrospective (lower panels) studies are presented. (a) Group III includes 153, 180 and 183; (b) Group III includes 153, 180, and 183; (c) Group III includes congeners 153 and 180.</p
Forest plot describing the association between potentially antiestrogenic and immunotoxic, dioxin-like PCBs (Group II) exposure and breast cancer risk.
<p>Apart from the overall analysis, the subgroup analyses on prospective (upper panels) and retrospective (lower panels) studies are presented. (a) Group II includes PCB congeners 74, 118, 138, 156 and 170; (b) Group II includes PCB congeners 74, 118, 138, 156, and 170; (c) Group IIA includes congeners 66, 77, 105, 118 and 126; (d) Group IIB includes congeners 128, 138 and 170.</p
Forest plot describing the association between total PCB exposure and breast cancer risk.
<p>Apart from the overall analysis, the subgroup analyses on prospective (upper panels) and retrospective (lower panels) studies are presented.</p
Forest plot describing the association between potentially estrogenic PCBs (Group I) exposure and breast cancer risk.
<p>Apart from the overall analysis, the subgroup analyses on prospective (upper panels) and retrospective (lower panels) studies are presented. (a) Group IB includes PCB congeners 177, 187 and 201; (b) Group IA includes PCB congeners 44, 52; (c) Group IB includes congeners 101, 187.</p
Thermal Expansion Anomaly in TTB Ferroelectrics: The Interplay between Framework Structure and Electric Polarization
Tetragonal
tungsten bronze (TTB) makes up a large family of functional materials
with fascinating dielectric, piezoelectric, or ferroelectric properties.
Understanding the thermal expansion mechanisms associated with their
physical properties is important for their practical applications
as well as theoretical investigations. Fortunately, the appearance
of anomalous thermal expansion in functional materials offers a chance
to capture the physics behind them. Herein, we report an investigation
of the thermal expansion anomalies in TTBs that are related to ferroelectric
transitions and summarize recent progress in this field. The special
role of Pb<sup>2+</sup> cation is elucidated. The interplay between
the thermal expansion anomaly, electric polarization, and framework
structure provides new insight into the structure–property
relationships in functional materials
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