Ambient air pollution and adverse birth outcomes: a natural experiment study

Background Radical regulations to improve air quality, including traffic control, were implemented prior to and during the 2008 Beijing Olympic Games. Consequently, ambient concentrations of nitrogen dioxide (NO 2 ) and particular matter 10 micrometers or less (PM 10 ), were reduced in a distinct and short window of time, which presented a natural experiment for testing the relationships between maternal exposure to PM 10 and NO 2 during pregnancy and adverse birth outcomes. Methods We estimated the effect of PM 10 and NO 2 exposure during each trimester of gestation on the risk of preterm birth among live births and the birth weight among term babies. The data were based on 50,874 live births delivered between January 1, 2006 and December 31, 2010 at the Beijing Haidian Maternal and Child Health Hospital. Air monitoring data for the same period were obtained from the Beijing Municipal Environmental Monitoring Center. Results Among full-term births, maternal exposure to NO 2 in the third trimester predicted birth weight, with each 10-unit increment (per 10 ug/m 3 ) in NO 2 concentration associated with a 13.78 g (95 % confidence interval: −21.12, −6.43; p \u3c 0.0001) reduction in birth weight. This association was maintained after adjusting for other pollutants, including carbon monoxide (CO), sulfur dioxide (SO 2 ), and PM 10 . No relationship was found between the concentration of PM 10 and low birth weight among full-term births. Neither PM 10 nor NO 2 concentrations predicted the risk of premature birth. Conclusions Exposure to ambient air pollution during certain periods of pregnancy may decrease birth weight, but the effect size is small

Induction of ROS generation and NF-κB activation in MARC-145 cells by a novel porcine reproductive and respiratory syndrome virus in Southwest of China isolate

Each ORF gene nucleotide sequence of YN-2011

Mantle Flow Underneath the South China Sea Revealed by Seismic Anisotropy

It Has Long Been Established that Plastic Flow in the Asthenosphere Interacts Constantly with the overlying Lithosphere and Plays a Pivotal Role in Controlling the Occurrence of Geohazards Such as Earthquakes and Volcanic Eruptions. Unfortunately, Accurately Characterizing the Direction and Lateral Extents of the Mantle Flow Field is Notoriously Difficult, Especially in Oceanic Areas Where Deployment of Ocean Bottom Seismometers (OBSs) is Expensive and Thus Rare. in This Study, by Applying Shear Wave Splitting Analyses to a Dataset Recorded by an OBS Array that We Deployed between Mid-2019 and Mid-2020 in the South China Sea (SCS), We Show that the Dominant Mantle Flow Field Has a NNW-SSE Orientation, Which Can Be Attributed to Mantle Flow Extruded from the Tibetan Plateau by the Ongoing Indian-Eurasian Collision. in Addition, the Results Suggest that E-W Oriented Flow Fields Observed in South China and the Indochina Peninsula Do Not Extend to the Central SCS

Genesis of a giant Paleoproterozoic strata-bound magnesite deposit: Constraints from Mg isotopes

The final publication is available at Elsevier via https://doi.org/10.1016/j.precamres.2016.06.020 © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Giant strata-bound magnesite deposits are absent in modern and most Phanerozoic sedimentary environments but occur predominantly in Precambrian strata. These deposits may have formed directly through precipitation of evolved Mg-rich seawater in an evaporative shallow-marine setting or, alternatively, by epigenetic–hydrothermal replacement of the Mg-rich carbonate precursor. To test these hypotheses, we obtained the first Mg isotope data from the world’s largest strata-bound magnesite deposit belt, hosted by the ca. 2.1 Ga Dashiqiao Formation in Northeast China. The Mg isotope compositions (d26Mg) of most magnesite ores in the Huaziyu deposit are heavier (–0.75 ± 0.26‰) than most Proterozoic sedimentary dolostones. The Mg isotope compositions and major and trace element data indicate that the magnesites are probably not of hydrothermal origin. Instead, a Mg-rich carbonate precursor precipitated from evaporating seawater in a semi-closed system. Diagenetic brines altered the Mg-rich carbonate precursor to magnesite. Subsequently, recrystallization during regional metamorphism produced coarsely crystalline and saddle magnesite. These interpretations are consistent with the geological features and other geochemical data (element concentrations and C and O isotopes) for the magnesite ores. Hence, we interpret the formation of the Huaziyu magnesite deposit to be dominated by evaporative sedimentation and brine diagenesis.Natural Science Foundation of China || (41203004) MLR Public Benefit Research Foundation of China || (201211074) NSERC Discovery Gran

The role of 245 phase in alkaline iron selenide superconductors revealed by high pressure studies

Here we show that a pressure of about 8 GPa suppresses both the vacancy order and the insulating phase, and a further increase of the pressure to about 18 GPa induces a second transition or crossover. No superconductivity has been found in compressed insulating 245 phase. The metallic phase in the intermediate pressure range has a distinct behavior in the transport property, which is also observed in the superconducting sample. We interpret this intermediate metal as an orbital selective Mott phase (OSMP). Our results suggest that the OSMP provides the physical pathway connecting the insulating and superconducting phases of these iron selenide materials.Comment: 32 pages, 4 figure

Metal/metalloid and phosphorus characteristics in porewater associated with manganese geochemistry: A case study in the Jiulong River Estuary, China.

Sediment porewater can be an important source of contaminants in the overlying water, but the mechanisms of metal(loid) and phosphorus (P) remobilization remain to be investigated. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) samplers were used to determine the porewater dissolved iron (Fe), manganese (Mn), cobalt (Co), chromium (Cr), vanadium (V), selenium (Se), arsenic (As), P and DGT-Labile S in coastal sediments in the Jiulong River Estuary (JRE), China. The results showed that high concentrations of dissolved Mn, Se and P were present in the overlying water, indicating potential water pollution with excessive amounts of Mn, Se and P. The dissolved Mn concentrations in the porewater were higher than the dissolved Fe concentrations, especially at submerged sites, demonstrating that Mn(III/IV) reduction is the dominant diagenetic pathway for organic carbon (OC) degradation, which directly affects Fe cycling by the competitive inhibition of Fe(III) reduction and Fe(II) reoxidation. Dissolved Co, Cr, V, Se, As and P show significant positive correlations with Mn but nearly no correlations with Fe, suggesting that the mobility of these metal(loid)s and P is associated with Mn but not Fe cycling in this region. In addition, the coelevated concentrations of the metal(loid)s, P and Mn at the submerged sites are attributed to the strengthened Mn reduction coupled with OC degradation fueled by hypoxia. The higher positive diffusion fluxes of Mn, Se and P were consistent with the excess Mn, Se and P concentrations in the overlying water, together with the approximately positive fluxes of the other metal(loid)s, indicating that sediment Mn(III/IV) reduction and concomitant metal(loid) and P remobilization might be vital pathways for metal(loid) and P migration to the overlying water

Metal/metalloid and phosphorus characteristics in porewater associated with manganese geochemistry: A case study in the Jiulong River Estuary, China

Abstract(#br)Sediment porewater can be an important source of contaminants in the overlying water, but the mechanisms of metal(loid) and phosphorus (P) remobilization remain to be investigated. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) samplers were used to determine the porewater dissolved iron (Fe), manganese (Mn), cobalt (Co), chromium (Cr), vanadium (V), selenium (Se), arsenic (As), P and DGT-Labile S in coastal sediments in the Jiulong River Estuary (JRE), China. The results showed that high concentrations of dissolved Mn, Se and P were present in the overlying water, indicating potential water pollution with excessive amounts of Mn, Se and P. The dissolved Mn concentrations in the porewater were higher than the dissolved Fe concentrations, especially at submerged sites, demonstrating that Mn(III/IV) reduction is the dominant diagenetic pathway for organic carbon (OC) degradation, which directly affects Fe cycling by the competitive inhibition of Fe(III) reduction and Fe(II) reoxidation. Dissolved Co, Cr, V, Se, As and P show significant positive correlations with Mn but nearly no correlations with Fe, suggesting that the mobility of these metal(loid)s and P is associated with Mn but not Fe cycling in this region. In addition, the coelevated concentrations of the metal(loid)s, P and Mn at the submerged sites are attributed to the strengthened Mn reduction coupled with OC degradation fueled by hypoxia. The higher positive diffusion fluxes of Mn, Se and P were consistent with the excess Mn, Se and P concentrations in the overlying water, together with the approximately positive fluxes of the other metal(loid)s, indicating that sediment Mn(III/IV) reduction and concomitant metal(loid) and P remobilization might be vital pathways for metal(loid) and P migration to the overlying water

Breakdown of Three-dimensional Dirac Semimetal State in pressurized Cd3As2

We report the first observation of a pressure-induced breakdown of the 3D-DSM state in Cd3As2, evidenced by a series of in-situ high-pressure synchrotron X-ray diffraction (XRD) and single crystal transport measurements. We find that Cd3As2 undergoes a structural phase transition from a metallic tetragonal (T) phase in space group I41/acd to a semiconducting monoclinic (M) phase in space group P21/c at critical pressure 2.57 GPa, above this pressure, an activation energy gap appears, accompanied by distinct switches in Hall resistivity slope and electron mobility. These changes of crystal symmetry and corresponding transport properties manifest the breakdown of the 3D-DSM state in pressurized Cd3As2.Comment: 17 pages, 4 figure