12 research outputs found
DataSheet2_Sensitivity Analysis for Modeling of Cr(VI) Transfer From Soil to Surface Runoff.DOCX
Heavy metal contamination in soil has become a serious environmental problem in China, and chromium is one of the major threats to human health. In order to better understand the transfer pattern of heavy metal hexavalent chromium from polluted sites into surface water, the influencing factors that affect solute transfer from soil into the surface runoff with linear and nonlinear adsorption equations based on a two-layer incomplete mixing model were analyzed in this study. The Quasi-Newton method was used to optimize model parameters by fitting with the experimental laboratory data of chromium (Cr(VI)) in surface runoff. The local sensitivity analysis and the Morris global sensitivity analysis approaches were used to assess the parameter importance of rainfall intensity p, the thickness of the mixing layer hmix, incomplete mixing parameter α and γ, the soil adsorption parameters, and the initial soil water content θ0. The study results showed that the optimized nonlinear models were better consistent with the experimental results than the linear adsorption equation model. The results of global sensitivity indicated that rainfall intensity p was the main factor influencing Cr(VI) transport from the soil into surface runoff. The hmix and the α in the two-layer model were vital parameters that influenced such transport processes. Moreover, the soil adsorption properties and the θ0 had the lowest effects on runoff Cr(VI) loss. The results indicate that for controlling pollution migration in surface runoff, it is essential to focus on the analysis of precipitation conditions and soil properties that control the thickness of the mixing layer and the degree of mixing.</p
Petrogenesis and tectonic regime of two types of Neoarchaean amphibolites in the northern margin of the North China Craton
The Neoarchaean crustal evolutionary processes of the North China Craton (NCC) provide a window to understanding the crust–mantle interaction in the Early Earth. The Jiefangyingzi amphibolites are located in the Bainaimiao arc belt, along the northern margin of the NCC. LA–ICP–MS U–Pb isotopic data reveal that the Type 1 amphibolites were formed at ~2562 Ma, and the Type 2 amphibolites were formed at ~2504 Ma, but were subsequently subjected to metamorphism at ~1889 Ma. Lu–Hf isotopic data of the Type 1 amphibolite show positive εHf(t) values (+1.2–+6.0) and TDM from 2612 Ma to 2791 Ma, suggesting a significant episode of 2.6–2.8 Ga crustal growth within the study area. Geochemically, the Type 1 amphibolites show high SiO2 contents (53.37%–55.19%), moderate LREE–enriched patterns (La/Sm)N = 2.42–3.15 and HREE–depleted patterns (Gd/Yb)N = 1.86–2.64, with negative Nb anomalies, which are similar to IAB–like rocks, suggesting that they were derived from partial melting of arc–related depleted mantle with intense subduction–related fluids metasomatism. The Type 2 amphibolites have lower SiO2 contents from 44.28% to 50.77%, and show LREE–depleted REE patterns ((La/Sm)N = 0.67–1.02), nearly unfractionated HREE patterns ((Gd/Yb)N = 0.89–1.77), with negative Nb, Th and positive Sr, Zr anomalies, which are close to N–MORB–like rocks, indicating that they were generated from partial melting of depleted mantle with slight fluid metasomatism. The geochronological, Lu–Hf isotopic and geochemical features show that the IAB–like rocks were formed in an intra–oceanic arc environment, coincide with the significant ~2.5–2.6 Ga episode of crustal growth in the NCC; The slightly younger MORB–like rocks reflect the spreading of the oceanic crust might last until ~2.5 Ga in the central zone.</p
Presentation1_The impact of slope and rainfall on the contaminant transport from mountainous groundwater to the lowland surface water.pdf
The surface water and groundwater in the mountainous area are vulnerable to contamination from the mining and transportation construction in Sichuan Province, China. Pollutants produced by anthropogenic activities transport within the groundwater from mountains to rivers on the plain, transferring contamination to the surface water. This study investigates the process of groundwater flow and contaminant transport from mountains to the lowlands based on synthetic numerical models. Two key factors are considered: precipitation and the slope of the mountain. Based on the real situation in Sichuan Province, four rainfall recharge rates are defined as 600, 800, 1,000, and 1,200 mm/yr, and five slope angles are considered: 20°, 25°, 30°, 35°, and 40°. The simulation results reveal that the groundwater level and solute transport are strongly influenced by the precipitation amounts and slope angles. The mountains with lower slopes maintain a relatively higher groundwater level under steady-state rainfall conditions; for example, groundwater levels decrease from 340 m to 300 m as slope angles increase at a 1,200 mm/yr precipitation level. Contaminant transport from the source in the mountain to the surface river is faster with increasing precipitations and decreasing slope angles. The model with 20° slope angle and 1,200 mm/yr precipitation exhibits the fastest solute migration, with the contaminant arrival time of 65 years. Furthermore, the models with 35° and 40° slope angles at a 600 mm/yr precipitation level show the slow transport speed with the contaminant arrival time of more than 75 years. In addition, higher precipitation may lead to more contaminant transport to the river. The analysis and findings of this study offer valuable insights into groundwater protection at the boundaries of mountains and plains.</p
The Precambrian Khondalite Belt in the Daqingshan area, North China Craton: evidence for multiple metamorphic events in the Palaeoproterozoic era
<p>High-grade pelitic metasedimentary rocks (khondalites) are widely distributed in the northwestern part of the North China
Craton and were named the ‘Khondalite Belt’. Prior to the application of zircon geochronology, a stratigraphic division of
the supracrustal rocks into several groups was established using interpretative field geology. We report here SHRIMP U–Pb
zircon ages and Hf-isotope data on metamorphosed sedimentary and magmatic rocks at Daqingshan, a typical area of the Khondalite
Belt. The main conclusions are as follows: (1) The early Precambrian supracrustal rocks belong to three sequences: a 2.56–2.51
Ga supracrustal unit (the previous Sanggan ‘group’), a 2.51–2.45 Ga supracrustal unit (a portion of the previous upper Wulashan
‘group’) and a 2.0–1.95 Ga supracrustal unit (including the previous lower Wulashan ‘group’, a portion of original upper Wulashan
‘group’ and the original Meidaizhao ‘group’) the units thus do not represent a true stratigraphy; (2) Strong tectono-thermal
events occurred during the late Neoarchaean to late Palaeoproterozoic, with four episodes recognized: 2.6–2.5, 2.45–2.37,
2.3–2.0 and 1.95–1.85 Ga, with the latest event being consistent with the assembly of the Palaeoproterozoic supercontinent
Columbia; (3) During the late Neoarchaean to late Palaeoproterozoic (2.55–2.5, 2.37 and 2.06 Ga) juvenile, mantle-derived
material was added to the crust.
</p
Redox-Activatable Theranostic Co-Prodrug for Precise Tumor Diagnosis and Selective Combination Chemotherapy
A novel theranostic co-prodrug SCB has been
designed
by combining a co-prodrug from CDDO-Me and SAHA with a biotin-coupled
near-infrared (NIR) probe hemicyanine via redox-responsive linker
thiolactate to enhance the tumor theranostic efficacy and reduce the
toxic side effects using both active and passive targeting strategies. SCB displayed reactive oxygen species (ROS)- and glutathione
(GSH)-dependent release of NIR fluorescence and two parent drugs.
Furthermore, the administration of SCB caused selective
illumination of the tumor tissues for >24 h, thereby guiding precise
removal of a tumor from intraoperative mice. Importantly, SCB exhibited highly efficient tumor inhibition, exerted selective combination
therapy through prodrug mode, and minimized the adverse effects. Finally, SCB induced mitochondrial depolarization, DNA damage, and
cell apoptosis through ROS generation and downregulation of HDAC6
protein, as verified by H2AX, Bax, cleaved-PARP, and Mcl-1 proteins.
Thus, we suggest that SCB can provide a new platform
for both precise diagnosis-guided tumor removal and selective combination
therapy with high safety
Additional file 1: of Light-Trapping Engineering for the Enhancements of Broadband and Spectra-Selective Photodetection by Self-Assembled Dielectric Microcavity Arrays
Figure S1. Fabrication of ZnO MCAs on Si PIN substrate. Figure S2. Detailed morphology of ZnO MCA arrays on PIN substrate. Figure S3. Large-scale ZnO MCA arrays on PIN silicon substrate. Figure S4. Near-field distribution patterns of ZnO MCA with shell thickness of 40Â nm. Figure S5. Simulation method and setup for the absorption profile. Figure S6. Comparison of the absorption profile and near-field distribution for the MCAs on silicon substrates under on/off-resonance wavelengths. Figure S7. Near-field distribution patterns of ZnO MCA with shell thickness of 60Â nm. Figure S8. Response stability of MCA-decorated PIN PD. (DOCX 3687âkb
Dual Tumor-Selective β‑Carboline-Based Fluorescent Probe for High-Contrast/Rapid Diagnosis of Clinical Tumor Tissues
Given
that precise/rapid intraoperative tumor margin identification
is still challenging, novel fluorescent probes HY and HYM, based on acidic tumor microenvironment (TME) activation
and organic anion transporting polypeptide (OATPs)-mediated selective
uptake, were constructed and synthesized. Both of them possessed acidic
pH-activatable and reversible fluorescence as well as large Stokes
shift. Compared with HY, HYM had a higher
(over 9-fold) enhancement in fluorescence with pH ranging from 7.6
to 4.0, and the fluorescence quantum yield of HYM (ΦF
= 0.49) at pH = 4.0 was 8-fold stronger than that (ΦF = 0.06)
at pH = 7.4. Mechanism research demonstrated that acidic TME-induced
protonation of the pyridine N atom on β-carbolines accounted
for the pH-sensitive fluorescence by influencing the intramolecular
charge transfer (ICT) effect. Furthermore, HYM selectively
lit up cancer cells and tumor tissues not only by “off–on”
fluorescence but also by OATPs (overexpressed on cancer cells)-mediated
cancer cellular internalization, offering dual tumor selectivity for
precise visualization of tumor mass and intraoperative guidance upon
in situ spraying. Most importantly, HYM enabled rapid
and high-contrast (tumor-to-normal tissue ratios > 6) human tumor
margin identification in clinical tumor tissues by simple spraying
within 6 min, being promising for aiding in clinical surgical resection
A Derivative of Piperlongumine and Ligustrazine as a Potential Thioredoxin Reductase Inhibitor in Drug-Resistant Hepatocellular Carcinoma
The natural products piperlongumine
(1) and ligustrazine
(2) have been reported to exert antiproliferative effects
against various types of cancer cells by up-regulating the level of
reactive oxidative species (ROS). However, the moderate activities
of 1 and 2 limit their application. To improve
their potential antitumor activity, novel piperlongumine/ligustrazine
derivatives were designed and prepared, and their potential pharmacological
effects were determined in vitro and in vivo. Among the derivatives
obtained, 11 exerted more prominent inhibitory activities
against proliferation of drug-sensitive/-resistant cancer cells with
lower IC50 values than 1. Particularly, the
IC50 value of 11 against drug-resistant Bel-7402/5-FU
cells was 0.9 μM, which was about 9-fold better than that of 1 (IC50 value of 8.4 μM). Mechanistic studies
showed that 11 demonstrated thioredoxin reductase (TrxR)
inhibitory activity, increase of ROS levels, decrease of mitochondrial
transmembrane potential levels, and occurrence of DNA damage and autophagy,
in a dose-dependent manner, via regulation of DNA damage protein H2AX
and autophagy-associated proteins LC3, beclin-1, and p62 in drug-resistant
Bel-7402/5-FU cells. Finally, compound 11 at 5 mg/kg
displayed potent antitumor activity in vivo with tumor suppression
of 76% (w/w). Taken together, compound 11 may represent
a promising candidate drug for the chemotherapy of drug-resistant
hepatocellular carcinoma and warrant more intensive study
Redox-Activatable Theranostic Co-Prodrug for Precise Tumor Diagnosis and Selective Combination Chemotherapy
A novel theranostic co-prodrug SCB has been
designed
by combining a co-prodrug from CDDO-Me and SAHA with a biotin-coupled
near-infrared (NIR) probe hemicyanine via redox-responsive linker
thiolactate to enhance the tumor theranostic efficacy and reduce the
toxic side effects using both active and passive targeting strategies. SCB displayed reactive oxygen species (ROS)- and glutathione
(GSH)-dependent release of NIR fluorescence and two parent drugs.
Furthermore, the administration of SCB caused selective
illumination of the tumor tissues for >24 h, thereby guiding precise
removal of a tumor from intraoperative mice. Importantly, SCB exhibited highly efficient tumor inhibition, exerted selective combination
therapy through prodrug mode, and minimized the adverse effects. Finally, SCB induced mitochondrial depolarization, DNA damage, and
cell apoptosis through ROS generation and downregulation of HDAC6
protein, as verified by H2AX, Bax, cleaved-PARP, and Mcl-1 proteins.
Thus, we suggest that SCB can provide a new platform
for both precise diagnosis-guided tumor removal and selective combination
therapy with high safety
Dual Tumor-Selective β‑Carboline-Based Fluorescent Probe for High-Contrast/Rapid Diagnosis of Clinical Tumor Tissues
Given
that precise/rapid intraoperative tumor margin identification
is still challenging, novel fluorescent probes HY and HYM, based on acidic tumor microenvironment (TME) activation
and organic anion transporting polypeptide (OATPs)-mediated selective
uptake, were constructed and synthesized. Both of them possessed acidic
pH-activatable and reversible fluorescence as well as large Stokes
shift. Compared with HY, HYM had a higher
(over 9-fold) enhancement in fluorescence with pH ranging from 7.6
to 4.0, and the fluorescence quantum yield of HYM (ΦF
= 0.49) at pH = 4.0 was 8-fold stronger than that (ΦF = 0.06)
at pH = 7.4. Mechanism research demonstrated that acidic TME-induced
protonation of the pyridine N atom on β-carbolines accounted
for the pH-sensitive fluorescence by influencing the intramolecular
charge transfer (ICT) effect. Furthermore, HYM selectively
lit up cancer cells and tumor tissues not only by “off–on”
fluorescence but also by OATPs (overexpressed on cancer cells)-mediated
cancer cellular internalization, offering dual tumor selectivity for
precise visualization of tumor mass and intraoperative guidance upon
in situ spraying. Most importantly, HYM enabled rapid
and high-contrast (tumor-to-normal tissue ratios > 6) human tumor
margin identification in clinical tumor tissues by simple spraying
within 6 min, being promising for aiding in clinical surgical resection
