Cause and predictability for the severe haze pollution in downtown Beijing in November–December 2015

Zhang, Ziyin,Gong, Daoyi,Mao, Rui,Kim, Seong-Joong,Xu, Jing,Zhao, Xiujuan,Ma, Zhiqiang Elsevier 2017 Science of the Total Environment Vol.592 No.-

<P><B>Abstract</B></P> <P>Based on the hourly PM<SUB>2.5</SUB> concentrations, meteorological variable records and ERA-Interim reanalysis data, a series of diagnostic analyses were conducted to explore the possible meteorological causes for the severe haze pollution that occurred in Beijing in November–December 2015. Using the online-coupled WRF-Chem model and GFS data, the predictability of hourly and daily PM<SUB>2.5</SUB> concentrations was evaluated. The results showed that, in the context of pollutant emission, the severe haze pollution in downtown Beijing in November–December 2015 was primarily attributed to anomalous local meteorological conditions, which were caused and strengthened by anomalous large-scale atmospheric circulations. The abnormal changes in the upper troposphere appeared to trigger the anomalies in the middle-lower troposphere and the local conditions. The numerical simulations can capture the spatial distribution patterns of the PM<SUB>2.5</SUB> concentrations for predictions of 1 to 10days in advance. The PM<SUB>2.5</SUB> concentration trends in downtown Beijing were generally consistent with the predictions on both daily and hourly time-scales, although the predictability decreased gradually as the lead times prolonged. The predictability of the daily mean PM<SUB>2.5</SUB> concentration was slightly higher than that of the hourly concentration. The statistical indices suggested that the predictions of daily and hourly mean PM<SUB>2.5</SUB> concentrations were generally skillful and reliable for maximum lead times of 8 and 5days, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Anomalous large-scale circulations led to severe haze in Beijing over Nov.–Dec. 2015. </LI> <LI> Abnormal changes at upper troposphere may be the trigger point for the haze events. </LI> <LI> Kinetic energy index could be used to evaluate the clearance capacity of atmosphere. </LI> <LI> The daily (hourly) PM<SUB>2.5</SUB> can be predicted in the maximum leading times of 8 (5) days. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Significant Decrease of PM2.5 in Beijing Based on Long-Term Records and Kolmogorov-Zurbenko Filter Approach

Zhang, Ziyin,Ma, Zhiqiang,Kim, Seong-Joong Taiwan Association for Aerosol Research 2018 Aerosol and air quality research Vol.18 No.3

Is the Antarctic oscillation trend during the recent decades unusual?

Zhang, Ziyin,Gong, Daoyi,Kim, Seongjoong,Mao, Rui,Yang, Jing Cambridge University Press 2014 Antarctic science Vol.26 No.4

<B>Abstract</B><P>The Antarctic oscillation (AAO) has been characterized by a persistently positive trend in summer (December-January-February, DJF) during the last 50 years. Thus, the question has arisen of whether the trend is unusual. By investigating five reconstructed historical AAO time series for the past 500 years, recurrences of similar and even stronger trends have been found, indicating that the recent DJF AAO trend is not unprecedented in a historical perspective. To estimate the possible roles played by greenhouse gases or/and ozone, an analysis for DJF AAO trends during the 1969-98 period was conducted using three multiple model ensembles derived from the projects of ‘The twentieth-century climate in coupled models’ (20C3M) and ‘Pre-industrial control experiment models’ (PICTL) of the fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC AR4). The results show that the ozone depletion over Antarctica and global warming may play significant roles in the strengthening trend. Combining the simulations and reconstructions we emphasize that the AAO trend related to global warming may get much stronger when enhanced by low-frequency natural variability.</P>

Congenital Pial Arteriovenous Fistula in the Temporal Region Draining into Cavernous Sinus: A Case Report

Ziyin Zhang,Kun Yang,Chaohua Wang,Changwei Zhang,Xiaodong Xie,Jianjian Tang 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.3

This report concerns a 4-month-old infant with progressive prominent and redness of his left eye since birth. This report concerns a 4-month-old infant with progressive prominent redness of his left eye since birth. Angiography revealed a congenital pial arteriovenous fistula between the temporal branch of the left posterior cerebral artery and left cavernous sinus through the sphenoparietal sinus, a condition not reported in the literature. The fistula was successfully occluded with two micro-coils by vertebrobasilar approach.

Mycobacterium vaccae induces a strong Th1 response that subsequently declines in C57BL/6 mice

Lijiao Zhang,Yanlong Jiang,Ziyin Cui,Wentao Yang,Limin Yue,Yingcong Ma,Shaohua Shi,Chun-fang Wang,Chun-feng Wang,Aidong Qian 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.4

Mycobacterium (M.) vaccae is a fast-growing species of saprophytic bacteria that is widely distributed. To understand the host immuneresponses induced by M. vaccae isolated from bovine submaxillary lymph nodes, C57BL/6 mice were infected with reference strain M. bovisBacillus Calmette-Guérin (BCG) and isolated M. vaccae using intraperitoneal injections. Comparison of the bacterial replication and organpathology between M. vaccae and M. bovis BCG revealed that M. vaccae was more malignant than M. bovis in mice. We also demonstratedthat serum from the M. vaccae-infected mice contained a higher expression level of gamma-interferon (IFN-), tumor necrosis factor alpha,monocyte chemoattractant protein-1, interleukin (IL)-4, IL-12, IL-10 and transforming growth factor beta than did the other groups, especiallyafter week 4. Furthermore, when the numbers of CD3+CD4+IFN-+ and CD3+CD4+IL4+ cells in the infected mice were observed by flowcytometry, we found that a powerful T helper 1 (Th1) response was induced by M. vaccae infection, which was associated with the emergenceof CD3+CD4+IFN-+ cells. However, the Th1 response declined over time, which was associated with appearance of the CD4+CD25+FoxP3+and CD4+CD25+CD152+Treg cell reaction. In addition, a strong Th2 response was found. Finally, we found that M. vaccae infection increasedthe production of type I IFNs, which was associated with a reduced Th1 response.

Seroprevalence of Toxoplasma gondii in cats in mainland China 2016–2020: a meta-analysis

Siyu Zhou,Ziyin Sang,Lijun Wang,Tangjie Zhang 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.1

Background: Toxoplasma gondii can infect humans and most animals and has a very high infection rate worldwide, including in China. The number of people infected with T. gondii in China increases with the number of cats. Objectives: We investigated the seropositive rate of T. gondii in cats over the last five years and analyzed the risk factors via meta-analysis. Methods: We retrieved 20 studies, with a total of 5,158 cats, published between 2016 and 2020, used the DerSimonian-Laird model and calculated seroprevalence estimates with the variance stabilizing double arcsine transformation. Results: The overall seroprevalence rate after sinusoidal conversion was 19.9% (95% confidence interval [CI], 15.9–23.9; 966/5,158), lower than the domestic report from 1995 to 2015 (24.5%, 95% CI, 20.1–29.0). There was substantial heterogeneity among studies (χ2 = 262.32; p < 0.001; I2 = 64.6%). Regression analysis of possible heterogeneous causes and subgroup analysis showed that age and whether cats were stray or not have a significant effect on the seropositive rate. Conclusions: Articles published in recent five years suggest that the seroprevalence estimates of Toxoplasma gondii in cats has decreased. Cats, as the final host of T. gondii, are an important cause of the spread of the parasite, and this is an important concern for public health.

Molecular Level Study of Graphene Networks Functionalized with Phenylenediamine Monomers for Supercapacitor Electrodes

Song, Bo,Choi, Ji Il,Zhu, Yuntong,Geng, Zhishuai,Zhang, Le,Lin, Ziyin,Tuan, Chia-chi,Moon, Kyoung-sik,Wong, Ching-ping American Chemical Society 2016 Chemistry of materials Vol.28 No.24

<P>Three phenylenediamine (PD) monomers, o-phenylenediamine (OPD), m-phenylenediamine (MPD), and p-phenylenediamine (PPD), were used to prepare the functionalized graphene (PD/rGO) networks. The results obtained from a series of chemical, thermal, and rheological analyses elucidated the mechanism of the covalent bonding and the existence of cross-linked graphene networks. The measured XRD patterns and molecular dynamic calculations discovered that those PPD and MPD molecules could enlarge graphene interlayer spacing to 1.41 and 1.30 nm, respectively, while OPD molecules were disorderly bonded or nonbonded to the basal planes of graphene layers, resulting in small and variable inter layer distances. The loadings of PD monomers were optimized to achieve superior supercapacitor performance. Electrochemical study showed that PPD/rGO exhibited the largest specific capacitance of 422 F/g with excellent cycling stability and low charge transfer resistance. The large variations in the capacitance values among PD/rGO networks with different PD monomers were explained by the difference in the graphene nanostructures, reversible redox transitions, and charge transfer characteristics. Particularly, density function theory calculations were adopted to compare electronic properties of the PD/rGO composites, including formation energy, electron density distribution, HOMO energy levels, and electron density of states near the Fermi level.</P>