Abstract. Haze pollution caused by PM2.5 is the largest air
quality concern in China in recent years. Long-term measurements of
PM2.5 and the precursors and chemical speciation are crucially important
for evaluating the efficiency of emission control, understanding formation
and transport of PM2.5 associated with the change of meteorology, and
accessing the impact of human activities on regional climate change.
Here we reported long-term continuous measurements of PM2.5, chemical
components, and their precursors at a regional background station, the
Station for Observing Regional Processes of the Earth System (SORPES), in
Nanjing, eastern China, since 2011. We found that PM2.5 at the station
has experienced a substantial decrease (−9.1 % yr−1), accompanied by even
a very significant reduction of SO2 (−16.7 % yr−1), since the national
“Ten Measures of Air” took action in 2013. Control of open biomass
burning and fossil-fuel combustion are the two dominant factors that
influence the PM2.5 reduction in early summer and winter, respectively.
In the cold season (November–January), the nitrate fraction was significantly
increased, especially when air masses were transported from the north. More NH3
available from a substantial reduction of SO2 and increased oxidization
capacity are the main factors for the enhanced nitrate formation. The
changes of year-to-year meteorology have contributed to 24 % of the PM2.5
decrease since 2013. This study highlights several important implications on
air pollution control policy in China.
Significance. With an alarming increase in recent years, diabetes mellitus has become a global challenge. Despite advances in treatment of diabetes mellitus, currently, medications available are unable to control the progression of diabetes and its complications. Growing evidence suggests that inflammation is an important pathogenic mediator in the development of diabetes mellitus. The perspectives including suggestions for new therapies involving the shift from metabolic stress to inflammation should be taken into account. Critical Issues. High-mobility group box 1 (HMGB1), a nonhistone nuclear protein regulating gene expression, was rediscovered as an endogenous danger signal molecule to trigger inflammatory responses when released into extracellular milieu in the late 1990s. Given the similarities of inflammatory response in the development of T2D, we will discuss the potential implication of HMGB1 in the pathogenesis of T2D. Importantly, we will summarize and renovate the role of HMGB1 and HMGB1-mediated inflammatory pathways in adipose tissue inflammation, insulin resistance, and islet dysfunction. Future Directions. HMGB1 and its downstream receptors RAGE and TLRs may serve as potential antidiabetic targets. Current and forthcoming projects in this territory will pave the way for prospective approaches targeting the center of HMGB1-mediated inflammation to improve T2D and its complications.
Understanding the relationship between brain activity and specific mental function is important for medical diagnosis of brain symptoms, such as epilepsy. Magnetoencephalography (MEG), which uses an array of high-sensitivity magnetometers to record magnetic field signals generated from neural currents occurring naturally in the brain, is a noninvasive method for locating the brain activities. The MEG is normally performed in a magnetically shielded room. Here, we introduce an unshielded MEG system based on optically pumped atomic magnetometers. We build an atomic magnetic gradiometer, together with feedback methods, to reduce the environment magnetic field noise. We successfully observe the alpha rhythm signals related to closed eyes and clear auditory evoked field signals in unshielded Earth’s field. Combined with improvements in the miniaturization of the atomic magnetometer, our method is promising to realize a practical wearable and movable unshielded MEG system and bring new insights into medical diagnosis of brain symptoms.
By analyzing the data of urban air pollutant measurements from 2013 to 2015 in Nanjing, East China, we found that the correlation coefficients between major atmospheric compound pollutants PM 2.5 and O 3 were respectively 0.40 in hot season (June, July and August) and −0.16 in cold season (December, January and February) with both passing the confidence level of 99%. This provides evidence for the inverse relations of ambient PM 2.5 and O 3 between cold and hot seasons in an urban area of East China. To understand the interaction of PM 2.5 and O 3 in air compound pollution, the underlying mechanisms on the inversion relations between cold and hot seasons were investigated from the seasonal variations in atmospheric oxidation and radiative forcing of PM 2.5 based on three-year environmental and meteorological data. The analyses showed that the augmentation of atmospheric oxidation could strengthen the production of secondary particles with the contribution up to 26.76% to ambient PM 2.5 levels. High O 3 concentrations in a strong oxidative air condition during hot season promoted the formation of secondary particles, which could result in a positive correlation between PM 2.5 and O 3 in hot season. In cold season with weak atmospheric oxidation, the enhanced PM 2.5 levels suppressed surface solar radiation, which could weaken O 3 production for decreasing ambient O 3 level with the low diurnal peaks. Under the high PM 2.5 level exceeding 115 µg·m −3 , the surface O 3 concentration dropped to 12.7 µg·m −3 at noon with a significant inhibitory effect, leading to a negative correlation between PM 2.5 and O 3 in cold season. This observational study revealed the interaction of PM 2.5 and O 3 in air compound pollution for understanding the seasonal change of atmospheric environment.
Ferumoxytol, which is originally intended for MRI and anemia treatment, is currently the only inorganic nanodrug approved by FDA for clinical application in vivo. Common ferumoxytol seems incapable of meeting the requirements for diverse applications. Thus, the development of a novel strategy based on co-precipitation to produce ferumoxytol with high quality is an imminent task. Herein, we proposed a physically assisted strategy, namely hydrocooling and magnetically internal heating co-precipitation, to optimize the properties of ferumoxytol and thus significantly enhance its magnetic performance. Magnetization of the newly developed ferumoxytol can reach 104-105 emu g-1 Fe, which is the highest value among the reported results. It has been found that the crystalline structures of the newly developed ferumoxytol have been greatly improved on the basis of pharmaceutical quality criteria.
Graphene and its derivatives are increasingly applied in nanoelectronics, biosensing, drug delivery, and biomedical applications. However, the information about its cytotoxicity remains limited. Herein, the distribution and cytotoxicity of graphene oxide (GO) and TiO2-graphene oxide composite (TiO2-GO composite) were evaluated in A549 cells. Cell viability and cell ultrastructure were measured. Our results indicated that GO could enter A549 cells and located in the cytoplasm and nucleus without causing any cell damage. TiO2 nanoparticles and GO would be separated after TiO2-GO composite entered A549 cells. TiO2-GO composite could induce cytotoxicity similar to TiO2 nanoparticles, which was probably attributed to oxidative stress. These results should be considered in the development of biological applications of GO and TiO2-GO composite.
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